Patent Application
20240340928
Examples of several of the various embodiments of the present disclosure are described herein with reference to the drawings.
In the present disclosure, various embodiments are presented as examples of how the disclosed techniques may be implemented and/or how the disclosed techniques may be practiced in environments and scenarios. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the scope. In fact, after reading the description, it will be apparent to one skilled in the relevant art how to implement alternative embodiments. The present embodiments should not be limited by any of the described exemplary embodiments. The embodiments of the present disclosure will be described with reference to the accompanying drawings. Limitations, features, and/or elements from the disclosed example embodiments may be combined to create further embodiments within the scope of the disclosure. Any figures which highlight the functionality and advantages, are presented for example purposes only. The disclosed architecture is sufficiently flexible and configurable, such that it may be utilized in ways other than that shown. For example, the actions listed in any flowchart may be re-ordered or only optionally used in some embodiments.
Embodiments may be configured to operate as needed. The disclosed mechanism may be performed when certain criteria are met, for example, in a wireless device, a base station, a radio environment, a network, a combination of the above, and/or the like. Example criteria may be based, at least in part, on for example, wireless device or network node configurations, traffic load, initial system set up, packet sizes, traffic characteristics, a combination of the above, and/or the like. When the one or more criteria are met, various example embodiments may be applied. Therefore, it may be possible to implement example embodiments that selectively implement disclosed protocols.
A base station may communicate with a mix of wireless devices. Wireless devices and/or base stations may support multiple technologies, and/or multiple releases of the same technology. Wireless devices may have some specific capability (ies) depending on wireless device category and/or capability (ies). When this disclosure refers to a base station communicating with a plurality of wireless devices, this disclosure may refer to a subset of the total wireless devices in a coverage area. This disclosure may refer to, for example, a plurality of wireless devices of given LTE or 5G release with a given capability and in a given sector of the base station. The plurality of wireless devices in this disclosure may refer to a selected plurality of wireless devices, and/or a subset of total wireless devices in a coverage area which perform according to disclosed methods, and/or the like. There may be a plurality of base stations or a plurality of wireless devices in a coverage area that may not comply with the disclosed methods, for example, those wireless devices or base stations may perform based on older releases of LTE or 5G technology.
In this disclosure, “a” and “an” and similar phrases are to be interpreted as “at least one” and “one or more.” Similarly, any term that ends with the suffix “(s)” is to be interpreted as “at least one” and “one or more.” In this disclosure, the term “may” is to be interpreted as “may, for example.” In other words, the term “may” is indicative that the phrase following the term “may” is an example of one of a multitude of suitable possibilities that may, or may not, be employed by one or more of the various embodiments. The terms “comprises” and “consists of”, as used herein, enumerate one or more components of the element being described. The term “comprises” is interchangeable with “includes” and does not exclude unenumerated components from being included in the element being described. By contrast, “consists of” provides a complete enumeration of the one or more components of the element being described. The term “based on”, as used herein, should be interpreted as “based at least in part on” rather than, for example, “based solely on”. The term “and/or” as used herein represents any possible combination of enumerated elements. For example, “A, B, and/or C” may represent A; B; C; A and B; A and C; B and C; or A, B, and C.
If A and B are sets and every element of A is an element of B, A is called a subset of B. In this specification, only non-empty sets and subsets are considered. For example, possible subsets of B= {cell1, cell2} are: {cell1}, {cell2}, and {cell1, cell2}. The phrase “based on” (or equally “based at least on”) is indicative that the phrase following the term “based on” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “in response to” (or equally “in response at least to”) is indicative that the phrase following the phrase “in response to” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “depending on” (or equally “depending at least to”) is indicative that the phrase following the phrase “depending on” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “employing/using” (or equally “employing/using at least”) is indicative that the phrase following the phrase “employing/using” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments.
The term configured may relate to the capacity of a device whether the device is in an operational or non-operational state. Configured may refer to specific settings in a device that affect the operational characteristics of the device whether the device is in an operational or non-operational state. In other words, the hardware, software, firmware, registers, memory values, and/or the like may be “configured” within a device, whether the device is in an operational or nonoperational state, to provide the device with specific characteristics. Terms such as “a control message to cause in a device” may mean that a control message has parameters that may be used to configure specific characteristics or may be used to implement certain actions in the device, whether the device is in an operational or non-operational state.
In this disclosure, parameters (or equally called, fields, or Information elements: IEs) may comprise one or more information objects, and an information object may comprise one or more other objects. For example, if parameter (IE) N comprises parameter (IE) M, and parameter (IE) M comprises parameter (IE) K, and parameter (IE) K comprises parameter (information element) J. Then, for example, N comprises K, and N comprises J. In an example embodiment, when one or more messages comprise a plurality of parameters, it implies that a parameter in the plurality of parameters is in at least one of the one or more messages, but does not have to be in each of the one or more messages.
Many features presented are described as being optional through the use of “may” or the use of parentheses. For the sake of brevity and legibility, the present disclosure does not explicitly recite each and every permutation that may be obtained by choosing from the set of optional features. The present disclosure is to be interpreted as explicitly disclosing all such permutations. For example, a system described as having three optional features may be embodied in seven ways, namely with just one of the three possible features, with any two of the three possible features or with three of the three possible features.
Many of the elements described in the disclosed embodiments may be implemented as modules. A module is defined here as an element that performs a defined function and has a defined interface to other elements. The modules described in this disclosure may be implemented in hardware, software in combination with hardware, firmware, wetware (e.g., hardware with a biological element) or a combination thereof, which may be behaviorally equivalent. For example, modules may be implemented as a software routine written in a computer language configured to be executed by a hardware machine (such as C, C++, Fortran, Java, Basic, Matlab or the like) or a modeling/simulation program such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript. It may be possible to implement modules using physical hardware that incorporates discrete or programmable analog, digital and/or quantum hardware. Examples of programmable hardware comprise: computers, microcontrollers, microprocessors, application-specific integrated circuits (ASICs); field programmable gate arrays (FPGAs); and complex programmable logic devices (CPLDs). Computers, microcontrollers and microprocessors are programmed using languages such as assembly, C, C++ or the like. FPGAs, ASICs and CPLDs are often programmed using hardware description languages (HDL) such as VHSIC hardware description language (VHDL) or Verilog that configure connections between internal hardware modules with lesser functionality on a programmable device. The mentioned technologies are often used in combination to achieve the result of a functional module.
The CN 102 may provide the wireless device 106 with an interface to one or more data networks (DNs), such as public DNS (e.g., the Internet), private DNs, and/or intra-operator DNs. As part of the interface functionality, the CN 102 may set up end-to-end connections between the wireless device 106 and the one or more DNs, authenticate the wireless device 106, and provide charging functionality.
The RAN 104 may connect the CN 102 to the wireless device 106 through radio communications over an air interface. As part of the radio communications, the RAN 104 may provide scheduling, radio resource management, and retransmission protocols. The communication direction from the RAN 104 to the wireless device 106 over the air interface is known as the downlink and the communication direction from the wireless device 106 to the RAN 104 over the air interface is known as the uplink. Downlink transmissions may be separated from uplink transmissions using frequency division duplexing (FDD), time-division duplexing (TDD), and/or some combination of the two duplexing techniques.
The term wireless device may be used throughout this disclosure to refer to and encompass any mobile device or fixed (non-mobile) device for which wireless communication is needed or usable. For example, a wireless device may be a telephone, smart phone, tablet, computer, laptop, sensor, meter, wearable device, Internet of Things (IoT) device, vehicle roadside unit (RSU), relay node, automobile, and/or any combination thereof. The term wireless device encompasses other terminology, including user equipment (UE), user terminal (UT), access terminal (AT), mobile station, handset, wireless transmit and receive unit (WTRU), and/or wireless communication device.
The RAN 104 may include one or more base stations (not shown). The term base station may be used throughout this disclosure to refer to and encompass a Node B (associated with UMTS and/or 3G standards), an Evolved Node B (eNB, associated with E-UTRA and/or 4G standards), a remote radio head (RRH), a baseband processing unit coupled to one or more RRHs, a repeater node or relay node used to extend the coverage area of a donor node, a Next Generation Evolved Node B (ng-eNB), a Generation Node B (gNB, associated with NR and/or 5G standards), an access point (AP, associated with, for example, Wi-Fi or any other suitable wireless communication standard), and/or any combination thereof. A base station may comprise at least one gNB Central Unit (gNB-CU) and at least one a gNB Distributed Unit (gNB-DU).
A base station included in the RAN 104 may include one or more sets of antennas for communicating with the wireless device 106 over the air interface. For example, one or more of the base stations may include three sets of antennas to respectively control three cells (or sectors). The size of a cell may be determined by a range at which a receiver (e.g., a base station receiver) can successfully receive the transmissions from a transmitter (e.g., a wireless device transmitter) operating in the cell. Together, the cells of the base stations may provide radio coverage to the wireless device 106 over a wide geographic area to support wireless device mobility.
In addition to three-sector sites, other implementations of base stations are possible. For example, one or more of the base stations in the RAN 104 may be implemented as a sectored site with more or less than three sectors. One or more of the base stations in the RAN 104 may be implemented as an access point, as a baseband processing unit coupled to several remote radio heads (RRHs), and/or as a repeater or relay node used to extend the coverage area of a donor node. A baseband processing unit coupled to RRHs may be part of a centralized or cloud RAN architecture, where the baseband processing unit may be either centralized in a pool of baseband processing units or virtualized. A repeater node may amplify and rebroadcast a radio signal received from a donor node. A relay node may perform the same/similar functions as a repeater node but may decode the radio signal received from the donor node to remove noise before amplifying and rebroadcasting the radio signal.
The RAN 104 may be deployed as a homogenous network of macrocell base stations that have similar antenna patterns and similar high-level transmit powers. The RAN 104 may be deployed as a heterogeneous network. In heterogeneous networks, small cell base stations may be used to provide small coverage areas, for example, coverage areas that overlap with the comparatively larger coverage areas provided by macrocell base stations. The small coverage areas may be provided in areas with high data traffic (or so-called “hotspots”) or in areas with weak macrocell coverage. Examples of small cell base stations include, in order of decreasing coverage area, microcell base stations, picocell base stations, and femtocell base stations or home base stations.
The Third-Generation Partnership Project (3GPP) was formed in 1998 to provide global standardization of specifications for mobile communication networks similar to the mobile communication network 100 in
The 5G-CN 152 provides the UEs 156 with an interface to one or more DNs, such as public DNS (e.g., the Internet), private DNs, and/or intra-operator DNs. As part of the interface functionality, the 5G-CN 152 may set up end-to-end connections between the UEs 156 and the one or more DNs, authenticate the UEs 156, and provide charging functionality. Compared to the CN of a 3GPP 4G network, the basis of the 5G-CN 152 may be a service-based architecture. This means that the architecture of the nodes making up the 5G-CN 152 may be defined as network functions that offer services via interfaces to other network functions. The network functions of the 5G-CN 152 may be implemented in several ways, including as network elements on dedicated or shared hardware, as software instances running on dedicated or shared hardware, or as virtualized functions instantiated on a platform (e.g., a cloud-based platform).
As illustrated in
The AMF 158A may perform functions such as Non-Access Stratum (NAS) signaling termination, NAS signaling security, Access Stratum (AS) security control, inter-CN node signaling for mobility between 3GPP access networks, idle mode UE reachability (e.g., control and execution of paging retransmission), registration area management, intra-system and inter-system mobility support, access authentication, access authorization including checking of roaming rights, mobility management control (subscription and policies), network slicing support, and/or session management function (SMF) selection. NAS may refer to the functionality operating between a CN and a UE, and AS may refer to the functionality operating between the UE and a RAN.
The 5G-CN 152 may include one or more additional network functions that are not shown in
The NG-RAN 154 may connect the 5G-CN 152 to the UEs 156 through radio communications over the air interface. The NG-RAN 154 may include one or more gNBs, illustrated as gNB 160A and gNB 160B (collectively gNBs 160) and/or one or more ng-eNBs, illustrated as ng-eNB 162A and ng-eNB 162B (collectively ng-eNBs 162). The gNBs 160 and ng-eNBs 162 may be more generically referred to as base stations. The gNBs 160 and ng-eNBs 162 may include one or more sets of antennas for communicating with the UEs 156 over an air interface. For example, one or more of the gNBs 160 and/or one or more of the ng-eNBs 162 may include three sets of antennas to respectively control three cells (or sectors). Together, the cells of the gNBs 160 and the ng-eNBs 162 may provide radio coverage to the UEs 156 over a wide geographic area to support UE mobility.
As shown in
The gNBs 160 and/or the ng-eNBs 162 may be connected to one or more AMF/UPF functions of the 5G-CN 152, such as the AMF/UPF 158, by means of one or more NG interfaces. For example, the gNB 160A may be connected to the UPF 158B of the AMF/UPF 158 by means of an NG-User plane (NG-U) interface. The NG-U interface may provide delivery (e.g., non-guaranteed delivery) of user plane PDUs between the gNB 160A and the UPF 158B. The gNB 160A may be connected to the AMF 158A by means of an NG-Control plane (NG-C) interface. The NG-C interface may provide, for example, NG interface management, UE context management, UE mobility management, transport of NAS messages, paging, PDU session management, and configuration transfer and/or warning message transmission.
The gNBs 160 may provide NR user plane and control plane protocol terminations towards the UEs 156 over the Uu interface. For example, the gNB 160A may provide NR user plane and control plane protocol terminations toward the UE 156A over a Uu interface associated with a first protocol stack. The ng-eNBs 162 may provide Evolved UMTS Terrestrial Radio Access (E-UTRA) user plane and control plane protocol terminations towards the UEs 156 over a Uu interface, where E-UTRA refers to the 3GPP 4G radio-access technology. For example, the ng-eNB 162B may provide E-UTRA user plane and control plane protocol terminations towards the UE 156B over a Uu interface associated with a second protocol stack.
The 5G-CN 152 was described as being configured to handle NR and 4G radio accesses. It will be appreciated by one of ordinary skill in the art that it may be possible for NR to connect to a 4G core network in a mode known as “non-standalone operation.” In non-standalone operation, a 4G core network is used to provide (or at least support) control-plane functionality (e.g., initial access, mobility, and paging). Although only one AMF/UPF 158 is shown in
As discussed, an interface (e.g., Uu, Xn, and NG interfaces) between the network elements in
The PDCPs 214 and 224 may perform header compression/decompression to reduce the amount of data that needs to be transmitted over the air interface, ciphering/deciphering to prevent unauthorized decoding of data transmitted over the air interface, and integrity protection (to ensure control messages originate from intended sources. The PDCPs 214 and 224 may perform retransmissions of undelivered packets, in-sequence delivery and reordering of packets, and removal of packets received in duplicate due to, for example, an intra-gNB handover. The PDCPs 214 and 224 may perform packet duplication to improve the likelihood of the packet being received and, at the receiver, remove any duplicate packets. Packet duplication may be useful for services that require high reliability.
Although not shown in
The RLCs 213 and 223 may perform segmentation, retransmission through Automatic Repeat Request (ARQ), and removal of duplicate data units received from MACs 212 and 222, respectively. The RLCs 213 and 223 may support three transmission modes: transparent mode (TM); unacknowledged mode (UM); and acknowledged mode (AM). Based on the transmission mode an RLC is operating, the RLC may perform one or more of the noted functions. The RLC configuration may be per logical channel with no dependency on numerologies and/or Transmission Time Interval (TTI) durations. As shown in
The MACs 212 and 222 may perform multiplexing/demultiplexing of logical channels and/or mapping between logical channels and transport channels. The multiplexing/demultiplexing may include multiplexing/demultiplexing of data units, belonging to the one or more logical channels, into/from Transport Blocks (TBs) delivered to/from the PHYs 211 and 221. The MAC 222 may be configured to perform scheduling, scheduling information reporting, and priority handling between UEs by means of dynamic scheduling. Scheduling may be performed in the gNB 220 (at the MAC 222) for downlink and uplink. The MACs 212 and 222 may be configured to perform error correction through Hybrid Automatic Repeat Request (HARQ) (e.g., one HARQ entity per carrier in case of Carrier Aggregation (CA), priority handling between logical channels of the UE 210 by means of logical channel prioritization, and/or padding. The MACs 212 and 222 may support one or more numerologies and/or transmission timings. In an example, mapping restrictions in a logical channel prioritization may control which numerology and/or transmission timing a logical channel may use. As shown in
The PHYs 211 and 221 may perform mapping of transport channels to physical channels and digital and analog signal processing functions for sending and receiving information over the air interface. These digital and analog signal processing functions may include, for example, coding/decoding and modulation/demodulation. The PHYs 211 and 221 may perform multi-antenna mapping. As shown in
The downlink data flow of
The remaining protocol layers in
Before describing the NR control plane protocol stack, logical channels, transport channels, and physical channels are first described as well as a mapping between the channel types. One or more of the channels may be used to carry out functions associated with the NR control plane protocol stack described later below.
Transport channels are used between the MAC and PHY layers and may be defined by how the information they carry is transmitted over the air interface. The set of transport channels defined by NR include, for example:
The PHY may use physical channels to pass information between processing levels of the PHY. A physical channel may have an associated set of time-frequency resources for carrying the information of one or more transport channels. The PHY may generate control information to support the low-level operation of the PHY and provide the control information to the lower levels of the PHY via physical control channels, known as L1/L2 control channels. The set of physical channels and physical control channels defined by NR include, for example:
Similar to the physical control channels, the physical layer generates physical signals to support the low-level operation of the physical layer. As shown in
The NAS protocols 217 and 237 may provide control plane functionality between the UE 210 and the AMF 230 (e.g., the AMF 158A) or, more generally, between the UE 210 and the CN. The NAS protocols 217 and 237 may provide control plane functionality between the UE 210 and the AMF 230 via signaling messages, referred to as NAS messages. There is no direct path between the UE 210 and the AMF 230 through which the NAS messages can be transported. The NAS messages may be transported using the AS of the Uu and NG interfaces. NAS protocols 217 and 237 may provide control plane functionality such as authentication, security, connection setup, mobility management, and session management.
The RRCs 216 and 226 may provide control plane functionality between the UE 210 and the gNB 220 or, more generally, between the UE 210 and the RAN. The RRCs 216 and 226 may provide control plane functionality between the UE 210 and the gNB 220 via signaling messages, referred to as RRC messages. RRC messages may be transmitted between the UE 210 and the RAN using signaling radio bearers and the same/similar PDCP, RLC, MAC, and PHY protocol layers. The MAC may multiplex control-plane and user-plane data into the same transport block (TB). The RRCs 216 and 226 may provide control plane functionality such as: broadcast of system information related to AS and NAS; paging initiated by the CN or the RAN; establishment, maintenance and release of an RRC connection between the UE 210 and the RAN; security functions including key management; establishment, configuration, maintenance and release of signaling radio bearers and data radio bearers; mobility functions; QoS management functions; the UE measurement reporting and control of the reporting; detection of and recovery from radio link failure (RLF); and/or NAS message transfer. As part of establishing an RRC connection, RRCs 216 and 226 may establish an RRC context, which may involve configuring parameters for communication between the UE 210 and the RAN.
In RRC connected 602, the UE has an established RRC context and may have at least one RRC connection with a base station. The base station may be similar to one of the one or more base stations included in the RAN 104 depicted in
In RRC idle 604, an RRC context may not be established for the UE. In RRC idle 604, the UE may not have an RRC connection with the base station. While in RRC idle 604, the UE may be in a sleep state for the majority of the time (e.g., to conserve battery power). The UE may wake up periodically (e.g., once in every discontinuous reception cycle) to monitor for paging messages from the RAN. Mobility of the UE may be managed by the UE through a procedure known as cell reselection. The RRC state may transition from RRC idle 604 to RRC connected 602 through a connection establishment procedure 612, which may involve a random access procedure as discussed in greater detail below.
In RRC inactive 606, the RRC context previously established is maintained in the UE and the base station. This allows for a fast transition to RRC connected 602 with reduced signaling overhead as compared to the transition from RRC idle 604 to RRC connected 602. While in RRC inactive 606, the UE may be in a sleep state and mobility of the UE may be managed by the UE through cell reselection. The RRC state may transition from RRC inactive 606 to RRC connected 602 through a connection resume procedure 614 or to RRC idle 604 though a connection release procedure 616 that may be the same as or similar to connection release procedure 608.
An RRC state may be associated with a mobility management mechanism. In RRC idle 604 and RRC inactive 606, mobility is managed by the UE through cell reselection. The purpose of mobility management in RRC idle 604 and RRC inactive 606 is to allow the network to be able to notify the UE of an event via a paging message without having to broadcast the paging message over the entire mobile communications network. The mobility management mechanism used in RRC idle 604 and RRC inactive 606 may allow the network to track the UE on a cell-group level so that the paging message may be broadcast over the cells of the cell group that the UE currently resides within instead of the entire mobile communication network. The mobility management mechanisms for RRC idle 604 and RRC inactive 606 track the UE on a cell-group level. They may do so using different granularities of grouping. For example, there may be three levels of cell-grouping granularity: individual cells; cells within a RAN area identified by a RAN area identifier (RAI); and cells within a group of RAN areas, referred to as a tracking area and identified by a tracking area identifier (TAI).
Tracking areas may be used to track the UE at the CN level. The CN (e.g., the CN 102 or the 5G-CN 152) may provide the UE with a list of TAIs associated with a UE registration area. If the UE moves, through cell reselection, to a cell associated with a TAI not included in the list of TAIs associated with the UE registration area, the UE may perform a registration update with the CN to allow the CN to update the UE's location and provide the UE with a new the UE registration area.
RAN areas may be used to track the UE at the RAN level. For a UE in RRC inactive 606 state, the UE may be assigned a RAN notification area. A RAN notification area may comprise one or more cell identities, a list of RAIs, or a list of TAIs. In an example, a base station may belong to one or more RAN notification areas. In an example, a cell may belong to one or more RAN notification areas. If the UE moves, through cell reselection, to a cell not included in the RAN notification area assigned to the UE, the UE may perform a notification area update with the RAN to update the UE's RAN notification area.
A base station storing an RRC context for a UE or a last serving base station of the UE may be referred to as an anchor base station. An anchor base station may maintain an RRC context for the UE at least during a period of time that the UE stays in a RAN notification area of the anchor base station and/or during a period of time that the UE stays in RRC inactive 606.
A gNB, such as gNBs 160 in
In NR, the physical signals and physical channels (discussed with respect to
The duration of a slot may depend on the numerology used for the OFDM symbols of the slot. In NR, a flexible numerology is supported to accommodate different cell deployments (e.g., cells with carrier frequencies below 1 GHz up to cells with carrier frequencies in the mm-wave range). A numerology may be defined in terms of subcarrier spacing and cyclic prefix duration. For a numerology in NR, subcarrier spacings may be scaled up by powers of two from a baseline subcarrier spacing of 15 kHz, and cyclic prefix durations may be scaled down by powers of two from a baseline cyclic prefix duration of 4.7 μs. For example, NR defines numerologies with the following subcarrier spacing/cyclic prefix duration combinations: 15 kHz/4.7 μs; 30 KHz/2.3 μs; 60 KHz/1.2 ps; 120 KHz/0.59 μs; and 240 KHz/0.29 μs.
A slot may have a fixed number of OFDM symbols (e.g., 14 OFDM symbols). A numerology with a higher subcarrier spacing has a shorter slot duration and, correspondingly, more slots per subframe.
NR may support wide carrier bandwidths (e.g., up to 400 MHz for a subcarrier spacing of 120 kHz). Not all UEs may be able to receive the full carrier bandwidth (e.g., due to hardware limitations). Also, receiving the full carrier bandwidth may be prohibitive in terms of UE power consumption. In an example, to reduce power consumption and/or for other purposes, a UE may adapt the size of the UE's receive bandwidth based on the amount of traffic the UE is scheduled to receive. This is referred to as bandwidth adaptation.
NR defines bandwidth parts (BWPs) to support UEs not capable of receiving the full carrier bandwidth and to support bandwidth adaptation. In an example, a BWP may be defined by a subset of contiguous RBs on a carrier. A UE may be configured (e.g., via an RRC layer) with one or more downlink BWPs and one or more uplink BWPs per serving cell (e.g., up to four downlink BWPs and up to four uplink BWPs per serving cell). At a given time, one or more of the configured BWPs for a serving cell may be active. These one or more BWPs may be referred to as active BWPs of the serving cell. When a serving cell is configured with a secondary uplink carrier, the serving cell may have one or more first active BWPs in the uplink carrier and one or more second active BWPs in the secondary uplink carrier.
For unpaired spectra, a downlink BWP from a set of configured downlink BWPs may be linked with an uplink BWP from a set of configured uplink BWPs if a downlink BWP index of the downlink BWP and an uplink BWP index of the uplink BWP are the same. For unpaired spectra, a UE may expect that a center frequency for a downlink BWP is the same as a center frequency for an uplink BWP.
For a downlink BWP in a set of configured downlink BWPs on a primary cell (PCell), a base station may configure a UE with one or more control resource sets (CORESETs) for at least one search space. A search space is a set of locations in the time and frequency domains where the UE may find control information. The search space may be a UE-specific search space or a common search space (potentially usable by a plurality of UEs). For example, a base station may configure a UE with a common search space, on a PCell or on a primary secondary cell (PSCell), in an active downlink BWP.
For an uplink BWP in a set of configured uplink BWPs, a BS may configure a UE with one or more resource sets for one or more PUCCH transmissions. A UE may receive downlink receptions (e.g., PDCCH or PDSCH) in a downlink BWP according to a configured numerology (e.g., subcarrier spacing and cyclic prefix duration) for the downlink BWP. The UE may transmit uplink transmissions (e.g., PUCCH or PUSCH) in an uplink BWP according to a configured numerology (e.g., subcarrier spacing and cyclic prefix length for the uplink BWP).
One or more BWP indicator fields may be provided in Downlink Control Information (DCI). A value of a BWP indicator field may indicate which BWP in a set of configured BWPs is an active downlink BWP for one or more downlink receptions. The value of the one or more BWP indicator fields may indicate an active uplink BWP for one or more uplink transmissions.
A base station may semi-statically configure a UE with a default downlink BWP within a set of configured downlink BWPs associated with a PCell. If the base station does not provide the default downlink BWP to the UE, the default downlink BWP may be an initial active downlink BWP. The UE may determine which BWP is the initial active downlink BWP based on a CORESET configuration obtained using the PBCH.
A base station may configure a UE with a BWP inactivity timer value for a PCell. The UE may start or restart a BWP inactivity timer at any appropriate time. For example, the UE may start or restart the BWP inactivity timer (a) when the UE detects a DCI indicating an active downlink BWP other than a default downlink BWP for a paired spectra operation; or (b) when a UE detects a DCI indicating an active downlink BWP or active uplink BWP other than a default downlink BWP or uplink BWP for an unpaired spectra operation. If the UE does not detect DCI during an interval of time (e.g., 1 ms or 0.5 ms), the UE may run the BWP inactivity timer toward expiration (for example, increment from zero to the BWP inactivity timer value, or decrement from the BWP inactivity timer value to zero). When the BWP inactivity timer expires, the UE may switch from the active downlink BWP to the default downlink BWP.
In an example, a base station may semi-statically configure a UE with one or more BWPs. A UE may switch an active BWP from a first BWP to a second BWP in response to receiving a DCI indicating the second BWP as an active BWP and/or in response to an expiry of the BWP inactivity timer (e.g., if the second BWP is the default BWP).
Downlink and uplink BWP switching (where BWP switching refers to switching from a currently active BWP to a not currently active BWP) may be performed independently in paired spectra. In unpaired spectra, downlink and uplink BWP switching may be performed simultaneously. Switching between configured BWPs may occur based on RRC signaling, DCI, expiration of a BWP inactivity timer, and/or an initiation of random access.
If a UE is configured for a secondary cell with a default downlink BWP in a set of configured downlink BWPs and a timer value, UE procedures for switching BWPs on a secondary cell may be the same/similar as those on a primary cell. For example, the UE may use the timer value and the default downlink BWP for the secondary cell in the same/similar manner as the UE would use these values for a primary cell.
To provide for greater data rates, two or more carriers can be aggregated and simultaneously transmitted to/from the same UE using carrier aggregation (CA). The aggregated carriers in CA may be referred to as component carriers (CCs). When CA is used, there are a number of serving cells for the UE, one for a CC. The CCs may have three configurations in the frequency domain.
In an example, up to 32 CCs may be aggregated. The aggregated CCs may have the same or different bandwidths, subcarrier spacing, and/or duplexing schemes (TDD or FDD). A serving cell for a UE using CA may have a downlink CC. For FDD, one or more uplink CCs may be optionally configured for a serving cell. The ability to aggregate more downlink carriers than uplink carriers may be useful, for example, when the UE has more data traffic in the downlink than in the uplink.
When CA is used, one of the aggregated cells for a UE may be referred to as a primary cell (PCell). The PCell may be the serving cell that the UE initially connects to at RRC connection establishment, reestablishment, and/or handover. The PCell may provide the UE with NAS mobility information and the security input. UEs may have different PCells. In the downlink, the carrier corresponding to the PCell may be referred to as the downlink primary CC (DL PCC). In the uplink, the carrier corresponding to the PCell may be referred to as the uplink primary CC (UL PCC). The other aggregated cells for the UE may be referred to as secondary cells (SCells). In an example, the SCells may be configured after the PCell is configured for the UE. For example, an SCell may be configured through an RRC Connection Reconfiguration procedure. In the downlink, the carrier corresponding to an SCell may be referred to as a downlink secondary CC (DL SCC). In the uplink, the carrier corresponding to the SCell may be referred to as the uplink secondary CC (UL SCC).
Configured SCells for a UE may be activated and deactivated based on, for example, traffic and channel conditions. Deactivation of an SCell may mean that PDCCH and PDSCH reception on the SCell is stopped and PUSCH, SRS, and CQI transmissions on the SCell are stopped. Configured SCells may be activated and deactivated using a MAC CE with respect to
Downlink control information, such as scheduling assignments and scheduling grants, for a cell may be transmitted on the cell corresponding to the assignments and grants, which is known as self-scheduling. The DCI for the cell may be transmitted on another cell, which is known as cross-carrier scheduling. Uplink control information (e.g., HARQ acknowledgments and channel state feedback, such as CQI, PMI, and/or RI) for aggregated cells may be transmitted on the PUCCH of the PCell. For a larger number of aggregated downlink CCs, the PUCCH of the PCell may become overloaded. Cells may be divided into multiple PUCCH groups.
A cell, comprising a downlink carrier and optionally an uplink carrier, may be assigned with a physical cell ID and a cell index. The physical cell ID or the cell index may identify a downlink carrier and/or an uplink carrier of the cell, for example, depending on the context in which the physical cell ID is used. A physical cell ID may be determined using a synchronization signal transmitted on a downlink component carrier. A cell index may be determined using RRC messages. In the disclosure, a physical cell ID may be referred to as a carrier ID, and a cell index may be referred to as a carrier index. For example, when the disclosure refers to a first physical cell ID for a first downlink carrier, the disclosure may mean the first physical cell ID is for a cell comprising the first downlink carrier. The same/similar concept may apply to, for example, a carrier activation. When the disclosure indicates that a first carrier is activated, the specification may mean that a cell comprising the first carrier is activated.
In CA, a multi-carrier nature of a PHY may be exposed to a MAC. In an example, a HARQ entity may operate on a serving cell. A transport block may be generated per assignment/grant per serving cell. A transport block and potential HARQ retransmissions of the transport block may be mapped to a serving cell.
In the downlink, a base station may transmit (e.g., unicast, multicast, and/or broadcast) one or more Reference Signals (RSs) to a UE (e.g., PSS, SSS, CSI-RS, DMRS, and/or PT-RS, as shown in
The SS/PBCH block may span one or more OFDM symbols in the time domain (e.g., 4 OFDM symbols, as shown in the example of
The location of the SS/PBCH block in the time and frequency domains may not be known to the UE (e.g., if the UE is searching for the cell). To find and select the cell, the UE may monitor a carrier for the PSS. For example, the UE may monitor a frequency location within the carrier. If the PSS is not found after a certain duration (e.g., 20 ms), the UE may search for the PSS at a different frequency location within the carrier, as indicated by a synchronization raster. If the PSS is found at a location in the time and frequency domains, the UE may determine, based on a known structure of the SS/PBCH block, the locations of the SSS and the PBCH, respectively. The SS/PBCH block may be a cell-defining SS block (CD-SSB). In an example, a primary cell may be associated with a CD-SSB. The CD-SSB may be located on a synchronization raster. In an example, a cell selection/search and/or reselection may be based on the CD-SSB.
The SS/PBCH block may be used by the UE to determine one or more parameters of the cell. For example, the UE may determine a physical cell identifier (PCI) of the cell based on the sequences of the PSS and the SSS, respectively. The UE may determine a location of a frame boundary of the cell based on the location of the SS/PBCH block. For example, the SS/PBCH block may indicate that it has been transmitted in accordance with a transmission pattern, wherein a SS/PBCH block in the transmission pattern is a known distance from the frame boundary.
The PBCH may use a QPSK modulation and may use forward error correction (FEC). The FEC may use polar coding. One or more symbols spanned by the PBCH may carry one or more DMRSs for demodulation of the PBCH. The PBCH may include an indication of a current system frame number (SFN) of the cell and/or a SS/PBCH block timing index. These parameters may facilitate time synchronization of the UE to the base station. The PBCH may include a master information block (MIB) used to provide the UE with one or more parameters. The MIB may be used by the UE to locate remaining minimum system information (RMSI) associated with the cell. The RMSI may include a System Information Block Type 1 (SIB1). The SIB1 may contain information needed by the UE to access the cell. The UE may use one or more parameters of the MIB to monitor PDCCH, which may be used to schedule PDSCH. The PDSCH may include the SIB1. The SIB1 may be decoded using parameters provided in the MIB. The PBCH may indicate an absence of SIB1. Based on the PBCH indicating the absence of SIB1, the UE may be pointed to a frequency. The UE may search for an SS/PBCH block at the frequency to which the UE is pointed.
The UE may assume that one or more SS/PBCH blocks transmitted with a same SS/PBCH block index are quasi co-located (QCLed) (e.g., having the same/similar Doppler spread, Doppler shift, average gain, average delay, and/or spatial Rx parameters). The UE may not assume QCL for SS/PBCH block transmissions having different SS/PBCH block indices.
SS/PBCH blocks (e.g., those within a half-frame) may be transmitted in spatial directions (e.g., using different beams that span a coverage area of the cell). In an example, a first SS/PBCH block may be transmitted in a first spatial direction using a first beam, and a second SS/PBCH block may be transmitted in a second spatial direction using a second beam.
In an example, within a frequency span of a carrier, a base station may transmit a plurality of SS/PBCH blocks. In an example, a first PCI of a first SS/PBCH block of the plurality of SS/PBCH blocks may be different from a second PCI of a second SS/PBCH block of the plurality of SS/PBCH blocks. The PCIs of SS/PBCH blocks transmitted in different frequency locations may be different or the same.
The CSI-RS may be transmitted by the base station and used by the UE to acquire channel state information (CSI). The base station may configure the UE with one or more CSI-RSs for channel estimation or any other suitable purpose. The base station may configure a UE with one or more of the same/similar CSI-RSs. The UE may measure the one or more CSI-RSs. The UE may estimate a downlink channel state and/or generate a CSI report based on the measuring of the one or more downlink CSI-RSs. The UE may provide the CSI report to the base station. The base station may use feedback provided by the UE (e.g., the estimated downlink channel state) to perform link adaptation.
The base station may semi-statically configure the UE with one or more CSI-RS resource sets. A CSI-RS resource may be associated with a location in the time and frequency domains and a periodicity. The base station may selectively activate and/or deactivate a CSI-RS resource. The base station may indicate to the UE that a CSI-RS resource in the CSI-RS resource set is activated and/or deactivated.
The base station may configure the UE to report CSI measurements. The base station may configure the UE to provide CSI reports periodically, aperiodically, or semi-persistently. For periodic CSI reporting, the UE may be configured with a timing and/or periodicity of a plurality of CSI reports. For aperiodic CSI reporting, the base station may request a CSI report. For example, the base station may command the UE to measure a configured CSI-RS resource and provide a CSI report relating to the measurements. For semi-persistent CSI reporting, the base station may configure the UE to transmit periodically, and selectively activate or deactivate the periodic reporting. The base station may configure the UE with a CSI-RS resource set and CSI reports using RRC signaling.
The CSI-RS configuration may comprise one or more parameters indicating, for example, up to 32 antenna ports. The UE may be configured to employ the same OFDM symbols for a downlink CSI-RS and a control resource set (CORESET) when the downlink CSI-RS and CORESET are spatially QCLed and resource elements associated with the downlink CSI-RS are outside of the physical resource blocks (PRBs) configured for the CORESET. The UE may be configured to employ the same OFDM symbols for downlink CSI-RS and SS/PBCH blocks when the downlink CSI-RS and SS/PBCH blocks are spatially QCLed and resource elements associated with the downlink CSI-RS are outside of PRBs configured for the SS/PBCH blocks.
Downlink DMRSs may be transmitted by a base station and used by a UE for channel estimation. For example, the downlink DMRS may be used for coherent demodulation of one or more downlink physical channels (e.g., PDSCH). An NR network may support one or more variable and/or configurable DMRS patterns for data demodulation. At least one downlink DMRS configuration may support a front-loaded DMRS pattern. A front-loaded DMRS may be mapped over one or more OFDM symbols (e.g., one or two adjacent OFDM symbols). A base station may semi-statically configure the UE with a number (e.g., a maximum number) of front-loaded DMRS symbols for PDSCH. A DMRS configuration may support one or more DMRS ports. For example, for single user-MIMO, a DMRS configuration may support up to eight orthogonal downlink DMRS ports per UE. For multiuser-MIMO, a DMRS configuration may support up to 4 orthogonal downlink DMRS ports per UE. A radio network may support (e.g., at least for CP-OFDM) a common DMRS structure for downlink and uplink, wherein a DMRS location, a DMRS pattern, and/or a scrambling sequence may be the same or different. The base station may transmit a downlink DMRS and a corresponding PDSCH using the same precoding matrix. The UE may use the one or more downlink DMRSs for coherent demodulation/channel estimation of the PDSCH.
In an example, a transmitter (e.g., a base station) may use a precoder matrices for a part of a transmission bandwidth. For example, the transmitter may use a first precoder matrix for a first bandwidth and a second precoder matrix for a second bandwidth. The first precoder matrix and the second precoder matrix may be different based on the first bandwidth being different from the second bandwidth. The UE may assume that a same precoding matrix is used across a set of PRBs. The set of PRBs may be denoted as a precoding resource block group (PRG).
A PDSCH may comprise one or more layers. The UE may assume that at least one symbol with DMRS is present on a layer of the one or more layers of the PDSCH. A higher layer may configure up to 3 DMRSs for the PDSCH.
Downlink PT-RS may be transmitted by a base station and used by a UE for phase-noise compensation. Whether a downlink PT-RS is present or not may depend on an RRC configuration. The presence and/or pattern of the downlink PT-RS may be configured on a UE-specific basis using a combination of RRC signaling and/or an association with one or more parameters employed for other purposes (e.g., modulation and coding scheme (MCS)), which may be indicated by DCI. When configured, a dynamic presence of a downlink PT-RS may be associated with one or more DCI parameters comprising at least MCS. An NR network may support a plurality of PT-RS densities defined in the time and/or frequency domains. When present, a frequency domain density may be associated with at least one configuration of a scheduled bandwidth. The UE may assume a same precoding for a DMRS port and a PT-RS port. A number of PT-RS ports may be fewer than a number of DMRS ports in a scheduled resource. Downlink PT-RS may be confined in the scheduled time/frequency duration for the UE. Downlink PT-RS may be transmitted on symbols to facilitate phase tracking at the receiver.
The UE may transmit an uplink DMRS to a base station for channel estimation. For example, the base station may use the uplink DMRS for coherent demodulation of one or more uplink physical channels. For example, the UE may transmit an uplink DMRS with a PUSCH and/or a PUCCH. The uplink DM-RS may span a range of frequencies that is similar to a range of frequencies associated with the corresponding physical channel. The base station may configure the UE with one or more uplink DMRS configurations. At least one DMRS configuration may support a front-loaded DMRS pattern. The front-loaded DMRS may be mapped over one or more OFDM symbols (e.g., one or two adjacent OFDM symbols). One or more uplink DMRSs may be configured to transmit at one or more symbols of a PUSCH and/or a PUCCH. The base station may semi-statically configure the UE with a number (e.g., maximum number) of front-loaded DMRS symbols for the PUSCH and/or the PUCCH, which the UE may use to schedule a single-symbol DMRS and/or a double-symbol DMRS. An NR network may support (e.g., for cyclic prefix orthogonal frequency division multiplexing (CP-OFDM)) a common DMRS structure for downlink and uplink, wherein a DMRS location, a DMRS pattern, and/or a scrambling sequence for the DMRS may be the same or different.
A PUSCH may comprise one or more layers, and the UE may transmit at least one symbol with DMRS present on a layer of the one or more layers of the PUSCH. In an example, a higher layer may configure up to three DMRSs for the PUSCH.
Uplink PT-RS (which may be used by a base station for phase tracking and/or phase-noise compensation) may or may not be present depending on an RRC configuration of the UE. The presence and/or pattern of uplink PT-RS may be configured on a UE-specific basis by a combination of RRC signaling and/or one or more parameters employed for other purposes (e.g., Modulation and Coding Scheme (MCS), which may be indicated by DCI. When configured, a dynamic presence of uplink PT-RS may be associated with one or more DCI parameters comprising at least MCS. A radio network may support a plurality of uplink PT-RS densities defined in time/frequency domain. When present, a frequency domain density may be associated with at least one configuration of a scheduled bandwidth. The UE may assume a same precoding for a DMRS port and a PT-RS port. A number of PT-RS ports may be fewer than a number of DMRS ports in a scheduled resource. For example, uplink PT-RS may be confined in the scheduled time/frequency duration for the UE.
SRS may be transmitted by a UE to a base station for channel state estimation to support uplink channel dependent scheduling and/or link adaptation. SRS transmitted by the UE may allow a base station to estimate an uplink channel state at one or more frequencies. A scheduler at the base station may employ the estimated uplink channel state to assign one or more resource blocks for an uplink PUSCH transmission from the UE. The base station may semi-statically configure the UE with one or more SRS resource sets. For an SRS resource set, the base station may configure the UE with one or more SRS resources. An SRS resource set applicability may be configured by a higher layer (e.g., RRC) parameter. For example, when a higher layer parameter indicates beam management, an SRS resource in an SRS resource set of the one or more SRS resource sets (e.g., with the same/similar time domain behavior, periodic, aperiodic, and/or the like) may be transmitted at a time instant (e.g., simultaneously). The UE may transmit one or more SRS resources in SRS resource sets. An NR network may support aperiodic, periodic and/or semi-persistent SRS transmissions. The UE may transmit SRS resources based on one or more trigger types, wherein the one or more trigger types may comprise higher layer signaling (e.g., RRC) and/or one or more DCI formats. In an example, at least one DCI format may be employed for the UE to select at least one of one or more configured SRS resource sets. An SRS trigger type 0 may refer to an SRS triggered based on a higher layer signaling. An SRS trigger type 1 may refer to an SRS triggered based on one or more DCI formats. In an example, when PUSCH and SRS are transmitted in a same slot, the UE may be configured to transmit SRS after a transmission of a PUSCH and a corresponding uplink DMRS.
The base station may semi-statically configure the UE with one or more SRS configuration parameters indicating at least one of following: a SRS resource configuration identifier; a number of SRS ports; time domain behavior of an SRS resource configuration (e.g., an indication of periodic, semi-persistent, or aperiodic SRS); slot, mini-slot, and/or subframe level periodicity; offset for a periodic and/or an aperiodic SRS resource; a number of OFDM symbols in an SRS resource; a starting OFDM symbol of an SRS resource; an SRS bandwidth; a frequency hopping bandwidth; a cyclic shift; and/or an SRS sequence ID.
An antenna port is defined such that the channel over which a symbol on the antenna port is conveyed can be inferred from the channel over which another symbol on the same antenna port is conveyed. If a first symbol and a second symbol are transmitted on the same antenna port, the receiver may infer the channel (e.g., fading gain, multipath delay, and/or the like) for conveying the second symbol on the antenna port, from the channel for conveying the first symbol on the antenna port. A first antenna port and a second antenna port may be referred to as quasi co-located (QCLed) if one or more large-scale properties of the channel over which a first symbol on the first antenna port is conveyed may be inferred from the channel over which a second symbol on a second antenna port is conveyed. The one or more large-scale properties may comprise at least one of: a delay spread; a Doppler spread; a Doppler shift; an average gain; an average delay; and/or spatial Receiving (Rx) parameters.
Channels that use beamforming require beam management. Beam management may comprise beam measurement, beam selection, and beam indication. A beam may be associated with one or more reference signals. For example, a beam may be identified by one or more beamformed reference signals. The UE may perform downlink beam measurement based on downlink reference signals (e.g., a channel state information reference signal (CSI-RS)) and generate a beam measurement report. The UE may perform the downlink beam measurement procedure after an RRC connection is set up with a base station.
The three beams illustrated in
CSI-RSs such as those illustrated in
In a beam management procedure, a UE may assess (e.g., measure) a channel quality of one or more beam pair links, a beam pair link comprising a transmitting beam transmitted by a base station and a receiving beam received by the UE. Based on the assessment, the UE may transmit a beam measurement report indicating one or more beam pair quality parameters comprising, e.g., one or more beam identifications (e.g., a beam index, a reference signal index, or the like), RSRP, a precoding matrix indicator (PMI), a channel quality indicator (CQI), and/or a rank indicator (RI).
A UE may initiate a beam failure recovery (BFR) procedure based on detecting a beam failure. The UE may transmit a BFR request (e.g., a preamble, a UCI, an SR, a MAC CE, and/or the like) based on the initiating of the BFR procedure. The UE may detect the beam failure based on a determination that a quality of beam pair link(s) of an associated control channel is unsatisfactory (e.g., having an error rate higher than an error rate threshold, a received signal power lower than a received signal power threshold, an expiration of a timer, and/or the like).
The UE may measure a quality of a beam pair link using one or more reference signals (RSs) comprising one or more SS/PBCH blocks, one or more CSI-RS resources, and/or one or more demodulation reference signals (DMRSs). A quality of the beam pair link may be based on one or more of a block error rate (BLER), an RSRP value, a signal to interference plus noise ratio (SINR) value, a reference signal received quality (RSRQ) value, and/or a CSI value measured on RS resources. The base station may indicate that an RS resource is quasi co-located (QCLed) with one or more DM-RSs of a channel (e.g., a control channel, a shared data channel, and/or the like). The RS resource and the one or more DMRSs of the channel may be QCLed when the channel characteristics (e.g., Doppler shift, Doppler spread, average delay, delay spread, spatial Rx parameter, fading, and/or the like) from a transmission via the RS resource to the UE are similar or the same as the channel characteristics from a transmission via the channel to the UE.
A network (e.g., a gNB and/or an ng-eNB of a network) and/or the UE may initiate a random access procedure. A UE in an RRC_IDLE state and/or an RRC_INACTIVE state may initiate the random access procedure to request a connection setup to a network. The UE may initiate the random access procedure from an RRC_CONNECTED state. The UE may initiate the random access procedure to request uplink resources (e.g., for uplink transmission of an SR when there is no PUCCH resource available) and/or acquire uplink timing (e.g., when uplink synchronization status is non-synchronized). The UE may initiate the random access procedure to request one or more system information blocks (SIBs) (e.g., other system information such as SIB2, SIB3, and/or the like). The UE may initiate the random access procedure for a beam failure recovery request. A network may initiate a random access procedure for a handover and/or for establishing time alignment for an SCell addition.
The configuration message 1310 may be transmitted, for example, using one or more RRC messages. The one or more RRC messages may indicate one or more random access channel (RACH) parameters to the UE. The one or more RACH parameters may comprise at least one of following: general parameters for one or more random access procedures (e.g., RACH-configGeneral); cell-specific parameters (e.g., RACH-ConfigCommon); and/or dedicated parameters (e.g., RACH-configDedicated). The base station may broadcast or multicast the one or more RRC messages to one or more UEs. The one or more RRC messages may be UE-specific (e.g., dedicated RRC messages transmitted to a UE in an RRC_CONNECTED state and/or in an RRC_INACTIVE state). The UE may determine, based on the one or more RACH parameters, a time-frequency resource and/or an uplink transmit power for transmission of the Msg 1 1311 and/or the Msg 3 1313. Based on the one or more RACH parameters, the UE may determine a reception timing and a downlink channel for receiving the Msg 2 1312 and the Msg 4 1314.
The one or more RACH parameters provided in the configuration message 1310 may indicate one or more Physical RACH (PRACH) occasions available for transmission of the Msg 1 1311. The one or more PRACH occasions may be predefined. The one or more RACH parameters may indicate one or more available sets of one or more PRACH occasions (e.g., prach-ConfigIndex). The one or more RACH parameters may indicate an association between (a) one or more PRACH occasions and (b) one or more reference signals. The one or more RACH parameters may indicate an association between (a) one or more preambles and (b) one or more reference signals. The one or more reference signals may be SS/PBCH blocks and/or CSI-RSs. For example, the one or more RACH parameters may indicate a number of SS/PBCH blocks mapped to a PRACH occasion and/or a number of preambles mapped to a SS/PBCH blocks.
The one or more RACH parameters provided in the configuration message 1310 may be used to determine an uplink transmit power of Msg 1 1311 and/or Msg 3 1313. For example, the one or more RACH parameters may indicate a reference power for a preamble transmission (e.g., a received target power and/or an initial power of the preamble transmission). There may be one or more power offsets indicated by the one or more RACH parameters. For example, the one or more RACH parameters may indicate: a power ramping step; a power offset between SSB and CSI-RS; a power offset between transmissions of the Msg 1 1311 and the Msg 3 1313; and/or a power offset value between preamble groups. The one or more RACH parameters may indicate one or more thresholds based on which the UE may determine at least one reference signal (e.g., an SSB and/or CSI-RS) and/or an uplink carrier (e.g., a normal uplink (NUL) carrier and/or a supplemental uplink (SUL) carrier).
The Msg 1 1311 may include one or more preamble transmissions (e.g., a preamble transmission and one or more preamble retransmissions). An RRC message may be used to configure one or more preamble groups (e.g., group A and/or group B). A preamble group may comprise one or more preambles. The UE may determine the preamble group based on a pathloss measurement and/or a size of the Msg 3 1313. The UE may measure an RSRP of one or more reference signals (e.g., SSBs and/or CSI-RSs) and determine at least one reference signal having an RSRP above an RSRP threshold (e.g., rsrp-ThresholdSSB and/or rsrp-ThresholdCSI-RS). The UE may select at least one preamble associated with the one or more reference signals and/or a selected preamble group, for example, if the association between the one or more preambles and the at least one reference signal is configured by an RRC message.
The UE may determine the preamble based on the one or more RACH parameters provided in the configuration message 1310. For example, the UE may determine the preamble based on a pathloss measurement, an RSRP measurement, and/or a size of the Msg 3 1313. As another example, the one or more RACH parameters may indicate: a preamble format; a maximum number of preamble transmissions; and/or one or more thresholds for determining one or more preamble groups (e.g., group A and group B). A base station may use the one or more RACH parameters to configure the UE with an association between one or more preambles and one or more reference signals (e.g., SSBs and/or CSI-RSs). If the association is configured, the UE may determine the preamble to include in Msg 1 1311 based on the association. The Msg 1 1311 may be transmitted to the base station via one or more PRACH occasions. The UE may use one or more reference signals (e.g., SSBs and/or CSI-RSs) for selection of the preamble and for determining of the PRACH occasion. One or more RACH parameters (e.g., ra-ssb-OccasionMskIndex and/or ra-OccasionList) may indicate an association between the PRACH occasions and the one or more reference signals.
The UE may perform a preamble retransmission if no response is received following a preamble transmission. The UE may increase an uplink transmit power for the preamble retransmission. The UE may select an initial preamble transmit power based on a pathloss measurement and/or a target received preamble power configured by the network. The UE may determine to retransmit a preamble and may ramp up the uplink transmit power. The UE may receive one or more RACH parameters (e.g., PREAMBLE_POWER_RAMPING_STEP) indicating a ramping step for the preamble retransmission. The ramping step may be an amount of incremental increase in uplink transmit power for a retransmission. The UE may ramp up the uplink transmit power if the UE determines a reference signal (e.g., SSB and/or CSI-RS) that is the same as a previous preamble transmission. The UE may count a number of preamble transmissions and/or retransmissions (e.g., PREAMBLE_TRANSMISSION_COUNTER). The UE may determine that a random access procedure completed unsuccessfully, for example, if the number of preamble transmissions exceeds a threshold configured by the one or more RACH parameters (e.g., preambleTransMax).
The Msg 2 1312 received by the UE may include an RAR. In some scenarios, the Msg 2 1312 may include multiple RARs corresponding to multiple UEs. The Msg 2 1312 may be received after or in response to the transmitting of the Msg 1 1311. The Msg 2 1312 may be scheduled on the DL-SCH and indicated on a PDCCH using a random access RNTI (RA-RNTI). The Msg 2 1312 may indicate that the Msg 1 1311 was received by the base station. The Msg 2 1312 may include a time-alignment command that may be used by the UE to adjust the UE's transmission timing, a scheduling grant for transmission of the Msg 3 1313, and/or a Temporary Cell RNTI (TC-RNTI). After transmitting a preamble, the UE may start a time window (e.g., ra-ResponseWindow) to monitor a PDCCH for the Msg 2 1312. The UE may determine when to start the time window based on a PRACH occasion that the UE uses to transmit the preamble. For example, the UE may start the time window one or more symbols after a last symbol of the preamble (e.g., at a first PDCCH occasion from an end of a preamble transmission). The one or more symbols may be determined based on a numerology. The PDCCH may be in a common search space (e.g., a Type1-PDCCH common search space) configured by an RRC message. The UE may identify the RAR based on a Radio Network Temporary Identifier (RNTI). RNTIs may be used depending on one or more events initiating the random access procedure. The UE may use random access RNTI (RA-RNTI). The RA-RNTI may be associated with PRACH occasions in which the UE transmits a preamble. For example, the UE may determine the RA-RNTI based on: an OFDM symbol index; a slot index; a frequency domain index; and/or a UL carrier indicator of the PRACH occasions. An example of RA-RNTI may be as follows:
RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id
where s_id may be an index of a first OFDM symbol of the PRACH occasion (e.g., 0≤ s_id<14), t_id may be an index of a first slot of the PRACH occasion in a system frame (e.g., 0≤ t_id<80), f_id may be an index of the PRACH occasion in the frequency domain (e.g., 0≤ f_id<8), and ul_carrier_id may be a UL carrier used for a preamble transmission (e.g., 0 for an NUL carrier, and 1 for an SUL carrier).
The UE may transmit the Msg 3 1313 in response to a successful reception of the Msg 2 1312 (e.g., using resources identified in the Msg 2 1312). The Msg 3 1313 may be used for contention resolution in, for example, the contention-based random access procedure illustrated in
The Msg 4 1314 may be received after or in response to the transmitting of the Msg 3 1313. If a C-RNTI was included in the Msg 3 1313, the base station will address the UE on the PDCCH using the C-RNTI. If the UE's unique C-RNTI is detected on the PDCCH, the random access procedure is determined to be successfully completed. If a TC-RNTI is included in the Msg 3 1313 (e.g., if the UE is in an RRC_IDLE state or not otherwise connected to the base station), Msg 4 1314 will be received using a DL-SCH associated with the TC-RNTI. If a MAC PDU is successfully decoded and a MAC PDU comprises the UE contention resolution identity MAC CE that matches or otherwise corresponds with the CCCH SDU sent (e.g., transmitted) in Msg 3 1313, the UE may determine that the contention resolution is successful and/or the UE may determine that the random access procedure is successfully completed.
The UE may be configured with a supplementary uplink (SUL) carrier and a normal uplink (NUL) carrier. An initial access (e.g., random access procedure) may be supported in an uplink carrier. For example, a base station may configure the UE with two separate RACH configurations: one for an SUL carrier and the other for an NUL carrier. For random access in a cell configured with an SUL carrier, the network may indicate which carrier to use (NUL or SUL). The UE may determine the SUL carrier, for example, if a measured quality of one or more reference signals is lower than a broadcast threshold. Uplink transmissions of the random access procedure (e.g., the Msg 1 1311 and/or the Msg 3 1313) may remain on the selected carrier. The UE may switch an uplink carrier during the random access procedure (e.g., between the Msg 1 1311 and the Msg 3 1313) in one or more cases. For example, the UE may determine and/or switch an uplink carrier for the Msg 1 1311 and/or the Msg 3 1313 based on a channel clear assessment (e.g., a listen-before-talk).
The contention-free random access procedure illustrated in
After transmitting a preamble, the UE may start a time window (e.g., ra-ResponseWindow) to monitor a PDCCH for the RAR. In the event of a beam failure recovery request, the base station may configure the UE with a separate time window and/or a separate PDCCH in a search space indicated by an RRC message (e.g., recoverySearchSpaceld). The UE may monitor for a PDCCH transmission addressed to a Cell RNTI (C-RNTI) on the search space. In the contention-free random access procedure illustrated in
Msg A 1331 may be transmitted in an uplink transmission by the UE. Msg A 1331 may comprise one or more transmissions of a preamble 1341 and/or one or more transmissions of a transport block 1342. The transport block 1342 may comprise contents that are similar and/or equivalent to the contents of the Msg 3 1313 illustrated in
The UE may initiate the two-step random access procedure in
The UE may determine, based on two-step RACH parameters included in the configuration message 1330, a radio resource and/or an uplink transmit power for the preamble 1341 and/or the transport block 1342 included in the Msg A 1331. The RACH parameters may indicate a modulation and coding schemes (MCS), a time-frequency resource, and/or a power control for the preamble 1341 and/or the transport block 1342. A time-frequency resource for transmission of the preamble 1341 (e.g., a PRACH) and a time-frequency resource for transmission of the transport block 1342 (e.g., a PUSCH) may be multiplexed using FDM, TDM, and/or CDM. The RACH parameters may enable the UE to determine a reception timing and a downlink channel for monitoring for and/or receiving Msg B 1332.
The transport block 1342 may comprise data (e.g., delay-sensitive data), an identifier of the UE, security information, and/or device information (e.g., an International Mobile Subscriber Identity (IMSI)). The base station may transmit the Msg B 1332 as a response to the Msg A 1331. The Msg B 1332 may comprise at least one of following: a preamble identifier; a timing advance command; a power control command; an uplink grant (e.g., a radio resource assignment and/or an MCS); a UE identifier for contention resolution; and/or an RNTI (e.g., a C-RNTI or a TC-RNTI). The UE may determine that the two-step random access procedure is successfully completed if: a preamble identifier in the Msg B 1332 is matched to a preamble transmitted by the UE; and/or the identifier of the UE in Msg B 1332 is matched to the identifier of the UE in the Msg A 1331 (e.g., the transport block 1342).
A UE and a base station may exchange control signaling. The control signaling may be referred to as L1/L2 control signaling and may originate from the PHY layer (e.g., layer 1) and/or the MAC layer (e.g., layer 2). The control signaling may comprise downlink control signaling transmitted from the base station to the UE and/or uplink control signaling transmitted from the UE to the base station.
The downlink control signaling may comprise: a downlink scheduling assignment; an uplink scheduling grant indicating uplink radio resources and/or a transport format; a slot format information; a preemption indication; a power control command; and/or any other suitable signaling. The UE may receive the downlink control signaling in a payload transmitted by the base station on a physical downlink control channel (PDCCH). The payload transmitted on the PDCCH may be referred to as downlink control information (DCI). In some scenarios, the PDCCH may be a group common PDCCH (GC-PDCCH) that is common to a group of UEs.
A base station may attach one or more cyclic redundancy check (CRC) parity bits to a DCI in order to facilitate detection of transmission errors. When the DCI is intended for a UE (or a group of the UEs), the base station may scramble the CRC parity bits with an identifier of the UE (or an identifier of the group of the UEs). Scrambling the CRC parity bits with the identifier may comprise Modulo-2 addition (or an exclusive OR operation) of the identifier value and the CRC parity bits. The identifier may comprise a 16-bit value of a radio network temporary identifier (RNTI).
DCIs may be used for different purposes. A purpose may be indicated by the type of RNTI used to scramble the CRC parity bits. For example, a DCI having CRC parity bits scrambled with a paging RNTI (P-RNTI) may indicate paging information and/or a system information change notification. The P-RNTI may be predefined as “FFFE” in hexadecimal. A DCI having CRC parity bits scrambled with a system information RNTI (SI-RNTI) may indicate a broadcast transmission of the system information. The SI-RNTI may be predefined as “FFFF” in hexadecimal. A DCI having CRC parity bits scrambled with a random access RNTI (RA-RNTI) may indicate a random access response (RAR). A DCI having CRC parity bits scrambled with a cell RNTI (C-RNTI) may indicate a dynamically scheduled unicast transmission and/or a triggering of PDCCH-ordered random access. A DCI having CRC parity bits scrambled with a temporary cell RNTI (TC-RNTI) may indicate a contention resolution (e.g., a Msg 3 analogous to the Msg 3 1313 illustrated in
Depending on the purpose and/or content of a DCI, the base station may transmit the DCIs with one or more DCI formats. For example, DCI format 0_0 may be used for scheduling of PUSCH in a cell. DCI format 0_0 may be a fallback DCI format (e.g., with compact DCI payloads). DCI format 0_1 may be used for scheduling of PUSCH in a cell (e.g., with more DCI payloads than DCI format 0_0). DCI format 1_0 may be used for scheduling of PDSCH in a cell. DCI format 1_0 may be a fallback DCI format (e.g., with compact DCI payloads). DCI format 1_1 may be used for scheduling of PDSCH in a cell (e.g., with more DCI payloads than DCI format 1_0). DCI format 2_0 may be used for providing a slot format indication to a group of UEs. DCI format 2_1 may be used for notifying a group of UEs of a physical resource block and/or OFDM symbol where the UE may assume no transmission is intended to the UE. DCI format 2_2 may be used for transmission of a transmit power control (TPC) command for PUCCH or PUSCH. DCI format 2_3 may be used for transmission of a group of TPC commands for SRS transmissions by one or more UEs. DCI format(s) for new functions may be defined in future releases. DCI formats may have different DCI sizes, or may share the same DCI size.
After scrambling a DCI with a RNTI, the base station may process the DCI with channel coding (e.g., polar coding), rate matching, scrambling and/or QPSK modulation. A base station may map the coded and modulated DCI on resource elements used and/or configured for a PDCCH. Based on a payload size of the DCI and/or a coverage of the base station, the base station may transmit the DCI via a PDCCH occupying a number of contiguous control channel elements (CCEs). The number of the contiguous CCEs (referred to as aggregation level) may be 1, 2, 4, 8, 16, and/or any other suitable number. A CCE may comprise a number (e.g., 6) of resource-element groups (REGs). A REG may comprise a resource block in an OFDM symbol. The mapping of the coded and modulated DCI on the resource elements may be based on mapping of CCEs and REGs (e.g., CCE-to-REG mapping).
The base station may transmit, to the UE, RRC messages comprising configuration parameters of one or more CORESETs and one or more search space sets. The configuration parameters may indicate an association between a search space set and a CORESET. A search space set may comprise a set of PDCCH candidates formed by CCEs at a given aggregation level. The configuration parameters may indicate: a number of PDCCH candidates to be monitored per aggregation level; a PDCCH monitoring periodicity and a PDCCH monitoring pattern; one or more DCI formats to be monitored by the UE; and/or whether a search space set is a common search space set or a UE-specific search space set. A set of CCEs in the common search space set may be predefined and known to the UE. A set of CCEs in the UE-specific search space set may be configured based on the UE's identity (e.g., C-RNTI).
As shown in
The UE may transmit uplink control signaling (e.g., uplink control information (UCI) to a base station. The uplink control signaling may comprise hybrid automatic repeat request (HARQ) acknowledgements for received DL-SCH transport blocks. The UE may transmit the HARQ acknowledgements after receiving a DL-SCH transport block. Uplink control signaling may comprise channel state information (CSI) indicating channel quality of a physical downlink channel. The UE may transmit the CSI to the base station. The base station, based on the received CSI, may determine transmission format parameters (e.g., comprising multi-antenna and beamforming schemes) for a downlink transmission. Uplink control signaling may comprise scheduling requests (SR). The UE may transmit an SR indicating that uplink data is available for transmission to the base station. The UE may transmit a UCI (e.g., HARQ acknowledgements (HARQ-ACK), CSI report, SR, and the like) via a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH). The UE may transmit the uplink control signaling via a PUCCH using one of several PUCCH formats.
There may be five PUCCH formats and the UE may determine a PUCCH format based on a size of the UCI (e.g., a number of uplink symbols of UCI transmission and a number of UCI bits). PUCCH format 0 may have a length of one or two OFDM symbols and may include two or fewer bits. The UE may transmit UCI in a PUCCH resource using PUCCH format 0 if the transmission is over one or two symbols and the number of HARQ-ACK information bits with positive or negative SR (HARQ-ACK/SR bits) is one or two. PUCCH format 1 may occupy a number between four and fourteen OFDM symbols and may include two or fewer bits. The UE may use PUCCH format 1 if the transmission is four or more symbols and the number of HARQ-ACK/SR bits is one or two. PUCCH format 2 may occupy one or two OFDM symbols and may include more than two bits. The UE may use PUCCH format 2 if the transmission is over one or two symbols and the number of UCI bits is two or more. PUCCH format 3 may occupy a number between four and fourteen OFDM symbols and may include more than two bits. The UE may use PUCCH format 3 if the transmission is four or more symbols, the number of UCI bits is two or more and PUCCH resource does not include an orthogonal cover code. PUCCH format 4 may occupy a number between four and fourteen OFDM symbols and may include more than two bits. The UE may use PUCCH format 4 if the transmission is four or more symbols, the number of UCI bits is two or more and the PUCCH resource includes an orthogonal cover code.
The base station may transmit configuration parameters to the UE for a plurality of PUCCH resource sets using, for example, an RRC message. The plurality of PUCCH resource sets (e.g., up to four sets) may be configured on an uplink BWP of a cell. A PUCCH resource set may be configured with a PUCCH resource set index, a plurality of PUCCH resources with a PUCCH resource being identified by a PUCCH resource identifier (e.g., pucch-Resourceid), and/or a number (e.g., a maximum number) of UCI information bits the UE may transmit using one of the plurality of PUCCH resources in the PUCCH resource set. When configured with a plurality of PUCCH resource sets, the UE may select one of the plurality of PUCCH resource sets based on a total bit length of the UCI information bits (e.g., HARQ-ACK, SR, and/or CSI). If the total bit length of UCI information bits is two or fewer, the UE may select a first PUCCH resource set having a PUCCH resource set index equal to “0”. If the total bit length of UCI information bits is greater than two and less than or equal to a first configured value, the UE may select a second PUCCH resource set having a PUCCH resource set index equal to “1”. If the total bit length of UCI information bits is greater than the first configured value and less than or equal to a second configured value, the UE may select a third PUCCH resource set having a PUCCH resource set index equal to “2”. If the total bit length of UCI information bits is greater than the second configured value and less than or equal to a third value (e.g., 1406), the UE may select a fourth PUCCH resource set having a PUCCH resource set index equal to “3”.
After determining a PUCCH resource set from a plurality of PUCCH resource sets, the UE may determine a PUCCH resource from the PUCCH resource set for UCI (HARQ-ACK, CSI, and/or SR) transmission. The UE may determine the PUCCH resource based on a PUCCH resource indicator in a DCI (e.g., with a DCI format 1_0 or DCI for 1_1) received on a PDCCH. A three-bit PUCCH resource indicator in the DCI may indicate one of eight PUCCH resources in the PUCCH resource set. Based on the PUCCH resource indicator, the UE may transmit the UCI (HARQ-ACK, CSI and/or SR) using a PUCCH resource indicated by the PUCCH resource indicator in the DCI.
The base station 1504 may connect the wireless device 1502 to a core network (not shown) through radio communications over the air interface (or radio interface) 1506. The communication direction from the base station 1504 to the wireless device 1502 over the air interface 1506 is known as the downlink, and the communication direction from the wireless device 1502 to the base station 1504 over the air interface is known as the uplink. Downlink transmissions may be separated from uplink transmissions using FDD, TDD, and/or some combination of the two duplexing techniques.
In the downlink, data to be sent to the wireless device 1502 from the base station 1504 may be provided to the processing system 1508 of the base station 1504. The data may be provided to the processing system 1508 by, for example, a core network. In the uplink, data to be sent to the base station 1504 from the wireless device 1502 may be provided to the processing system 1518 of the wireless device 1502. The processing system 1508 and the processing system 1518 may implement layer 3 and layer 2 OSI functionality to process the data for transmission. Layer 2 may include an SDAP layer, a PDCP layer, an RLC layer, and a MAC layer, for example, with respect to
After being processed by processing system 1508, the data to be sent to the wireless device 1502 may be provided to a transmission processing system 1510 of base station 1504. Similarly, after being processed by the processing system 1518, the data to be sent to base station 1504 may be provided to a transmission processing system 1520 of the wireless device 1502. The transmission processing system 1510 and the transmission processing system 1520 may implement layer 1 OSI functionality. Layer 1 may include a PHY layer with respect to
At the base station 1504, a reception processing system 1512 may receive the uplink transmission from the wireless device 1502. At the wireless device 1502, a reception processing system 1522 may receive the downlink transmission from base station 1504. The reception processing system 1512 and the reception processing system 1522 may implement layer 1 OSI functionality. Layer 1 may include a PHY layer with respect to
As shown in
The processing system 1508 and the processing system 1518 may be associated with a memory 1514 and a memory 1524, respectively. Memory 1514 and memory 1524 (e.g., one or more non-transitory computer readable mediums) may store computer program instructions or code that may be executed by the processing system 1508 and/or the processing system 1518 to carry out one or more of the functionalities discussed in the present application. Although not shown in
The processing system 1508 and/or the processing system 1518 may comprise one or more controllers and/or one or more processors. The one or more controllers and/or one or more processors may comprise, for example, a general-purpose processor, a digital signal processor (DSP), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) and/or other programmable logic device, discrete gate and/or transistor logic, discrete hardware components, an on-board unit, or any combination thereof. The processing system 1508 and/or the processing system 1518 may perform at least one of signal coding/processing, data processing, power control, input/output processing, and/or any other functionality that may enable the wireless device 1502 and the base station 1504 to operate in a wireless environment.
The processing system 1508 and/or the processing system 1518 may be connected to one or more peripherals 1516 and one or more peripherals 1526, respectively. The one or more peripherals 1516 and the one or more peripherals 1526 may include software and/or hardware that provide features and/or functionalities, for example, a speaker, a microphone, a keypad, a display, a touchpad, a power source, a satellite transceiver, a universal serial bus (USB) port, a hands-free headset, a frequency modulated (FM) radio unit, a media player, an Internet browser, an electronic control unit (e.g., for a motor vehicle), and/or one or more sensors (e.g., an accelerometer, a gyroscope, a temperature sensor, a radar sensor, a lidar sensor, an ultrasonic sensor, a light sensor, a camera, and/or the like). The processing system 1508 and/or the processing system 1518 may receive user input data from and/or provide user output data to the one or more peripherals 1516 and/or the one or more peripherals 1526. The processing system 1518 in the wireless device 1502 may receive power from a power source and/or may be configured to distribute the power to the other components in the wireless device 1502. The power source may comprise one or more sources of power, for example, a battery, a solar cell, a fuel cell, or any combination thereof. The processing system 1508 and/or the processing system 1518 may be connected to a GPS chipset 1517 and a GPS chipset 1527, respectively. The GPS chipset 1517 and the GPS chipset 1527 may be configured to provide geographic location information of the wireless device 1502 and the base station 1504, respectively.
A wireless device may receive from a base station one or more messages (e.g., RRC messages) comprising configuration parameters of a plurality of cells (e.g., primary cell, secondary cell). The wireless device may communicate with at least one base station (e.g., two or more base stations in dual-connectivity) via the plurality of cells. The one or more messages (e.g., as a part of the configuration parameters) may comprise parameters of physical, MAC, RLC, PCDP, SDAP, RRC layers for configuring the wireless device. For example, the configuration parameters may comprise parameters for configuring physical and MAC layer channels, bearers, etc. For example, the configuration parameters may comprise parameters indicating values of timers for physical, MAC, RLC, PCDP, SDAP, RRC layers, and/or communication channels.
A timer may begin running once it is started and continue running until it is stopped or until it expires. A timer may be started if it is not running or restarted if it is running. A timer may be associated with a value (e.g., the timer may be started or restarted from a value or may be started from zero and expire once it reaches the value). The duration of a timer may not be updated until the timer is stopped or expires (e.g., due to BWP switching). A timer may be used to measure a time period/window for a process. When the specification refers to an implementation and procedure related to one or more timers, it will be understood that there are multiple ways to implement the one or more timers. For example, it will be understood that one or more of the multiple ways to implement a timer may be used to measure a time period/window for the procedure. For example, a random access response window timer may be used for measuring a window of time for receiving a random access response. In an example, instead of starting and expiry of a random access response window timer, the time difference between two time stamps may be used. When a timer is restarted, a process for measurement of time window may be restarted. Other example implementations may be provided to restart a measurement of a time window.
A UE may be either in an RRC connected state or in an RRC inactive state when an RRC connection has been established. When no RRC connection is established, the UE is in an RRC idle state.
When a UE is in an RRC idle state, (an RRC layer of) the UE or a base station may support PLMN selection; broadcast of system information; cell re-selection mobility; paging for mobile terminated data is initiated by 5GC; DRX for core network (CN) paging configured by non-access stratum (NAS). When a UE is in an RRC idle state, a UE specific DRX may be configured by upper layers; and/or UE controlled mobility based on network configuration. When a UE is in an RRC idle state, (an RRC layer of) the UE may: monitor short messages transmitted with P-RNTI over DCI; monitor a paging channel for core network (CN) paging using serving temporary mobile subscriber identity (S-TMSI) (e.g., 5G-S-TMSI); perform neighbouring cell measurements and cell (re-) selection; acquire system information; send SI request; perform logging of available measurements together with location and time for logged measurement configured UEs.
When a UE is in an RRC inactive state, (an RRC layer of) the UE or a base station may support PLMN selection; broadcast of system information; cell re-selection mobility; paging is initiated by NG-RAN (RAN paging); RAN-based notification area (RNA) is managed by NG-RAN; DRX for RAN paging configured by NG-RAN; core network (e.g., 5G core, 5GC)-RAN (e.g., a base station) connection (both control and/or user planes) is established for UE; an UE AS context is stored in RAN and the UE; RAN knows the RNA which the UE belongs to. For example, when (the RRC layer) of a UE is in an RRC inactive state, a UE specific DRX may be configured by upper layers or by RRC layer; the UE may perform/support UE controlled mobility based on network configuration; the UE may store the UE inactive AS context; a RAN-based notification area (RNA) may be configured by the RRC layer. When a UE is in an RRC inactive state, (an RRC layer of) the UE may: monitor short messages transmitted with P-RNTI over DCI; monitor a paging channel for CN paging using S-TMSI and RAN paging using full inactive-RNTI (I-RNTI) (or full resume identity); perform neighbouring cell measurements and cell (re-) selection; perform RAN-based notification area (RNA) updates periodically and when moving outside the configured RAN-based notification area; acquire system information; send SI request; perform logging of available measurements together with location and time for logged measurement configured UEs.
When a UE is in an RRC connected state, (an RRC layer of) the UE or a base station may support that: 5GC-NG-RAN connection (both C/U-planes) is established for UE; an UE AS context is stored in RAN (e.g., a base station) and the UE; RAN knows the cell which the UE belongs to; transfer of unicast data to/from the UE; network controlled mobility including measurements. For example, when a UE is in an RRC connected state, (an RRC layer of) the UE may: store the AS context; transfer/receive unicast data; at lower layers, be configured with a UE specific DRX; for UEs supporting CA, use of one or more SCells, aggregated with the SpCell, for increased bandwidth; for UEs supporting DC, use of one SCG, aggregated with the MCG, for increased bandwidth; perform/support Network controlled mobility within NR and to/from E-UTRA; when a UE is in an RRC connected state, the UE may: monitor short messages transmitted with P-RNTI over DCI; monitor control channels associated with the shared data channel to determine if data is scheduled for it; provide channel quality and feedback information; perform neighbouring cell measurements and measurement reporting; acquire system information; perform immediate minimization of drive tests (MDT) measurement together with available location reporting.
Radio bearers may be categorized into two groups: data radio bearers (DRB) for user plane data and signalling radio bearers (SRB) for control plane data.
Signalling radio bearers” (SRBs) may be defined as radio bearers (RBs) that are used only for a transmission of RRC and NAS messages. Following SRBs may be defined: SRB0 may be for RRC messages using the common control channel (CCCH) logical channel; SRB1 may be for RRC messages (which may include a piggybacked NAS message) as well as for NAS messages prior to an establishment of SRB2, all using dedicated control channel (DCCH) logical channel; SRB2 may be for NAS messages and for RRC messages which may include logged measurement information, all using DCCH logical channel. SRB2 may have a lower priority than SRB1 and may be configured by the network after access stratum (AS) security activation; SRB3 may be for specific RRC messages when UE is in dual connectivity (e.g., (NG) EN-DC or NR-DC), all using DCCH logical channel. In downlink, piggybacking of NAS messages may be used for one dependent (e.g., with joint success/failure) procedure: bearer establishment/modification/release. In uplink piggybacking of NAS message may be used for transferring the initial NAS message during (RRC) connection setup and (RRC) connection resume. NAS messages transferred via SRB2 may be contained in RRC messages, which may not include any RRC protocol control information. Once AS security is activated, all RRC messages on SRB1, SRB2 and SRB3, including those containing NAS messages, may be integrity protected and ciphered by PDCP. NAS independently may apply integrity protection and ciphering to the NAS messages. Split SRB may is supported for dual connectivity (e.g., multi radio (MR)-DC options) in both SRB1 and SRB2. The split SRB may be not supported for SRB0 and SRB3. For operation with shared spectrum channel access, SRB0, SRB1 and SRB3 may be assigned with the highest priority channel access priority class (CAPC), (e.g., CAPC=1) while CAPC for SRB2 is configurable.
A MAC layer of an UE or a base station may offer different kinds of data transfer service. Each logical channel type may be defined by what type of information is transferred. Logical channels may be classified into two groups: control channels and traffic channels. control channels may be used for the transfer of control plane information: broadcast control channel (BCCH) which is a downlink channel for broadcasting system control information; paging control channel (PCCH) which is a downlink channel that carries paging messages; common control channel (CCCH) which is a channel for transmitting control information between UEs and network. This channel is used for UEs having no RRC connection with the network; and dedicated control channel (DCCH) which is a point-to-point bi-directional channel that transmits dedicated control information between a UE and the network. Used by UEs having an RRC connection. Traffic channels may be used for the transfer of user plane information: dedicated traffic channel (DTCH) which is point-to-point channel, dedicated to one UE, for the transfer of user information. A DTCH may exist in both uplink and downlink.
A UE may transition to an RRC connected state when an RRC connection is established or resumed. The UE may transition to an RRC idle state when RRC connection is released or suspended. The UE may transition to an RRC inactive state when RRC connection is suspended. When the UE is in an RRC idle state, the UE may have a suspended RRC connection. Based on the suspended RRC connection in the RRC idle state, the UE is in an RRC idle state with a suspended RRC connection.
An RRC connection establishment may comprise the establishment of SRB1. A base station may complete the RRC connection establishment prior to completing the establishment of a connection (e.g., N2/N3 connection) with a core network, (e.g., prior to receiving the UE context information from core network entity (e.g., AMF)). Access stratum (AS) security may be not activated during the initial phase of the RRC connection. During the initial phase of the RRC connection, the base station may configure the UE to perform measurement reporting. The UE may send the corresponding measurement reports after successful AS security activation. The UE may receive or accept a handover message (e.g., a handover command) when AS security has been activated.
Upon receiving the UE context from the core network (e.g., AMF), an RAN (a base station) may activate AS security (both ciphering and integrity protection) using the initial AS security activation procedure. RRC messages to activate AS security (command and successful response) may be integrity protected while ciphering is started after completion of the procedure. The response to the RRC messages used to activate AS security may be not ciphered, while the subsequent messages (e.g., used to establish SRB2 and DRBs) may be both integrity protected and ciphered. After having initiated the initial AS security activation procedure, the network (e.g., the base station) may initiate the establishment of SRB2 and DRBs, e.g., the network may do this prior to receiving the confirmation of the initial AS security activation from the UE. The network may apply both ciphering and integrity protection for RRC reconfiguration messages used to establish SRB2 and DRBs. The network should release the RRC connection if the initial AS security activation and/or the radio bearer establishment fails. A configuration with SRB2 without DRB or with DRB without SRB2 may be not supported (i.e., SRB2 and at least one DRB must be configured in the same RRC Reconfiguration message, and it may be not allowed to release all the DRBs without releasing the RRC Connection). For integrated access and backhaul mobile termination (IAB-MT), a configuration with SRB2 without DRB may be supported.
The release of the RRC connection may be initiated by the network. The procedure of the release may be used to re-direct the UE to an NR frequency or an E-UTRA carrier frequency.
The suspension of the RRC connection may be initiated by the network. When the RRC connection is suspended, the UE may store the UE Inactive AS context and any configuration received from the network, and transit to RRC inactive state. The RRC message to suspend the RRC connection may be integrity protected and ciphered.
The resumption of a suspended RRC connection may be initiated by upper layers when the UE needs to transit from RRC inactive state to RRC connected state or by RRC layer to perform an RNA update or by RAN paging from RAN (e.g., a base station). When the RRC connection is resumed, network may configure the UE according to the RRC connection resume procedure based on the stored UE Inactive AS context and any RRC configuration received from the network. The RRC connection resume procedure re-activates AS security and re-establishes SRB(s) and DRB(s).
In response to a request to resume the RRC connection, the network may resume the suspended RRC connection and send/transition UE to RRC connected state, or reject the request to resume and send UE to RRC inactive state (with a wait timer), or directly re-suspend the RRC connection and send UE to RRC_INACTIVE, or directly release the RRC connection and send/transition UE to RRC idle state, or instruct the UE to initiate NAS level recovery (in this case the network sends an RRC setup message). For user data (DRBs), ciphering may provide user data confidentiality and integrity protection provides user data integrity. For RRC signalling (SRBs), ciphering may provide signalling data confidentiality and integrity protection signalling data integrity. Ciphering and integrity protections may be optionally configured except for RRC signalling for which integrity protection may be always configured. Ciphering and integrity protection may be configured per DRB.
For key management and data handling, network entities or a UE processing cleartext may be protected from physical attacks and located in a secure environment. Base station (e.g., gNB or eNB) (AS) keys may be cryptographically separated from the (NAS) keys. Separate AS and NAS level security mode command (SMC) procedures may be used. A sequence number (COUNT) may be used as input to the ciphering and integrity protection and a given sequence number may be used once for a given key (except for identical re-transmission) on the same radio bearer in the same direction.
Keys for security may are organized and derived as follows. A key for a core network entity (e.g., AMF or a key for mobility management entity (MME)) may comprise KAMF (or KMME). The key for a core network entity may be a key derived by mobile equipment (ME) of a UE and a security anchor function (SEAF) from a key for the SEAF (KSEAF). Keys for NAS signalling may comprise: KNASint is a key derived by mobile equipment (ME) of a UE and the core network from a key for the core network entity, which may be used for the protection of NAS signalling with a particular integrity algorithm; and KNASenc is a key derived by ME and the core network entity from a key for the core network entity (e.g., KAMF/KMME), which may be used for the protection of NAS signalling with a particular encryption algorithm. A key for a base station (e.g., gNB or eNB) may comprise KgNB (or KeNB) is a key derived by ME and a core network entity (e.g., AMF/MME) from a key for the core network entity (e.g., KAMF/KMME). A key for a base station may be further derived by ME and source base station when performing horizontal or vertical key derivation. Keys for UP traffic may comprise: KUPenc is a key derived by ME and a base station from key for a base station, which may be used for the protection of UP traffic between ME and a base station with a particular encryption algorithm; KUPint may be a key derived by ME and a base station from a key for a base station, which may be used for the protection of UP traffic between ME and a base station with a particular integrity algorithm. Keys for RRC signalling may comprise: KRRCint is a key derived by ME and a base station from a key for a base station, which may be used for the protection of RRC signalling with a particular integrity algorithm; KRRCenc is a key derived by ME and a base station from a key for a base station, which may be used for the protection of RRC signalling with a particular encryption algorithm. Intermediate keys may comprise: next hop parameters (NH) is a key derived by ME and a core network entity (e.g., AMF/MME) to provide forward security; KgNB* (or KeNB*) is a key derived by ME and a base station when performing a horizontal or vertical key derivation.
A primary authentication may enable mutual authentication between the UE and the network and provide an anchor key called KSEAF. From KSEAF, a key for a core network entity (e.g., KAMF/KMME) may be created during e.g., primary authentication or NAS key re-keying and key refresh events. Based on the key for the core network entity, KNASint and KNASenc may be then derived when running a successful NAS SMC procedure.
Whenever an initial AS security context needs to be established between UE and a base station, a core network entity (e.g., AMF/MME) and the UE may derive a key for a base station (e.g., KgNB/KeNB) and a next hop parameter (NH). The key for a base station and the NH may be derived from the key for a core network entity. A next hop chaining counter (NCC) may be associated with each key for a base station and NH parameter. A key for a base station may be associated with the NCC corresponding to the NH value from which it was derived. At initial setup, the key for a base station may be derived directly from a key for a core network entity, and be then considered to be associated with a virtual NH parameter with NCC value equal to zero. At initial setup, the derived NH value may be associated with the NCC value one. On handovers, the basis for the key for a base station that will be used between the UE and the target base station, called KgNB* (or KeNB*), may be derived from either the currently active key for a base station or from the NH parameter. If KgNB* (or KeNB*) may be derived from the currently active key for a base station, this is referred to as a horizontal key derivation and is indicated to UE with an NCC that does not increase. If the KgNB* (or KeNB*) is derived from the NH parameter, the derivation is referred to as a vertical key derivation and is indicated to UE with an NCC increase. KRRCint, KRRCenc, KUPint and KUPenc may be derived based on a key for a base station after a new key for a base station is derived.
Based on key derivation, a base station with knowledge of a key for a base station (e.g., a KgNB/KeNB), shared with a UE, may be unable to compute any previous KgNB that has been used between the same UE and a previous base station, therefore providing backward security. A base station with knowledge of a key for a base station shared with a UE, may be unable to predict any future key for a base station that will be used between the same UE and another base station after n or more handovers (since NH parameters are only computable by the UE and the core network entity (e.g., AMF/MME)).
An AS SMC procedure may be for RRC and UP security algorithms negotiation and RRC security activation. When AS security context is to be established in a base station, the AMF (or MME) may send security capabilities of a UE to the base station. The base station may choose a ciphering algorithm. The chosen ciphering algorithm may have the highest priority from its configured list and be also present in the security capabilities. The base station may choose an integrity algorithm. The chosen integrity algorithm may have the highest priority from its configured list and be also present in the security capabilities. The chosen algorithms may be indicated to the UE in the AS SMC and this message may be integrity protected. RRC downlink ciphering (encryption) at the base station may start after sending the AS SMC message. RRC uplink deciphering (decryption) at the base station may start after receiving and successful verification of the integrity protected AS security mode complete message from the UE. The UE may verify the validity of the AS SMC message from the base station by verifying the integrity of the received message. RRC uplink ciphering (encryption) at the UE may start after sending the AS security mode complete message. RRC downlink deciphering (decryption) at the UE may start after receiving and successful verification of the AS SMC message. The RRC connection reconfiguration procedure used to add DRBs may be performed only after RRC security has been activated as part of the AS SMC procedure.
A UE may support integrity protected DRBs. In case of failed integrity check (e.g., faulty or missing message authentication code for integrity (MAC-I)), the concerned packet data unit (PDU) may be discarded by a receiving PDCP entity. Key refresh may be possible for a key for a base station (KgNB/KeNB), KRRC-enc, KRRC-Int, KUP-enc, and KUP-int and may be initiated by the base station when a PDCP COUNTs are about to be re-used with the same Radio Bearer identity and with the same KgNB. Key re-keying may be possible for the key for a base station (KgNB/KeNB), KRRC-enc, KRRC-int, KUP-enc, and KUP-int and may be initiated by a core network entity (e.g., AMF/MME) when a AS security context different from the currently active one may be activated.
When a UE transition from an RRC idle state to an RRC connected state, RRC protection keys and UP protection keys may be generated while keys for NAS protection as well as higher layer keys are assumed to be already available. These higher layer keys may have been established as a result of an authentication and key agreement (AKA) run, or as a result of a transfer from another AMF during handover or idle mode mobility. When a UE transitions from an RRC connected state to an RRC idle state, base station may delete the keys it stores for that UE such that state information for idle mode UEs only has to be maintained in a core network entity (e.g., AMF/MME). A base station may do no longer store state information about the corresponding UE and delete the current keys from its memory (e.g., when transitioning an RRC connected state to an RRC idle state): the base station and UE may delete NH, key for a base station, KgNB, KRRCint, KRRCenc, KUPint and KUPenc and related NCC; the core network entity (e.g., AMF/MME) and UE may keep key for a core network entity (e.g., KAMF/KMME), KNASint and KNASenc stored.
On mobility with vertical key derivation the NH may be further bound to the target physical cell identifier (PCI) and its frequency absolute radio frequency channel number-downlink link (ARFCN-DL) before it is taken into use as the key for a base station in the target base station. On mobility with horizontal key derivation the currently active key for a base station may be further bound to the target PCI (PCI of the target cell) and its frequency ARFCN-DL before it is taken into use as the key for a base station in the target gNB. In both cases, ARFCN-DL may be the absolute frequency of SSB of the target primary cell (PCell). It may be not required to change the AS security algorithms during intra-gNB-central unit (CU) handover. If the UE does not receive an indication of new AS security algorithms during an intra-gNB-CU handover, the UE may continue to use the same algorithms as before the handover.
AS security may comprise of the integrity protection and ciphering of RRC signalling (SRBs) and user data (DRBs). The AS may apply four different security keys: one for the integrity protection of RRC signalling (KRRCint), one for the ciphering of RRC signalling (KRRCenc), one for integrity protection of user data (KUPint) and one for the ciphering of user data (KUPenc). The four AS keys may be derived from a key for a base station (e.g., KgNB/KgNB). The key for a base station may be based on a key for a core network entity (KAMF/KMME), which may be handled by upper layers (e.g., NAS layer). The integrity protection and ciphering algorithms may be changed with reconfiguration with sync (e.g., handover command). The AS keys (KgNB, KRRCint, KRRCenc, KUPint and KUPenc) may change upon reconfiguration with sync and upon connection re-establishment and connection resume. For each radio bearer an independent counter (count) may be maintained for each direction. For each radio bearer, the count may be used as input for ciphering and integrity protection.
Paging may allow a base station to reach UEs in an RRC idle state and in an RRC inactive state through paging messages, and to notify UEs in an RRC idle state, in an RRC inactive state and an RRC connected state of system information change, and earthquake and tsunami warning system (ETWS) or commercial mobile alert service (CMAS) indications through short messages. Both paging messages and short messages may be addressed with P-RNTI on PDCCH. The paging messages may be sent on PCCH, the short message may be sent over PDCCH directly.
While a UE is in an RRC idle state, the UE may monitor a paging channels for core network (CN)-initiated paging. While a UE is in an RRC inactive state, the UE may monitor paging channels for RAN-initiated paging. A UE may need not monitor paging channels continuously though. Paging DRX is defined where the UE in an RRC idle state or an RRC inactive state may be only required to monitor paging channels during one paging occasion (PO) per DRX cycle. The Paging DRX cycles may be configured by the network (e.g., a base station or a core network entity (e.g., AMF/MME): for CN-initiated paging, a default cycle may be broadcast in system information; For CN-initiated paging, a UE specific cycle may be configured via an NAS signalling; For RAN-initiated paging, a UE-specific cycle may be configured via an RRC signalling; The UE may use the shortest of the DRX cycles applicable. For example, a UE in an RRC idle state may use the shortest of the first two cycles above. A UE in RRC_INACTIVE may use the shortest of the three cycles above.
The POs of a UE for CN-initiated and RAN-initiated paging may be based on the same UE identity (ID), resulting in overlapping POs for both. The number of different POs in a DRX cycle may be configurable via system information and a network may distribute UEs to those POs based on their IDs.
When in RRC_CONNECTED, the UE may monitor the paging channels in any PO signalled in system information for SI change indication and PWS notification. A UE in RRC connected state only may monitor paging channels on the active BWP with common search space configured. For operation with shared spectrum channel access, a UE may be configured for an additional number of PDCCH monitoring occasions in its PO to monitor for paging. When the UE detects a PDCCH transmission within the UE's PO addressed with P-RNTI, the UE may be not required to monitor the subsequent PDCCH monitoring occasions within this PO.
A network (e.g., a base station) may initiate a paging procedure by transmitting the paging message at the UE's paging occasion. The network may address multiple UEs within a paging message by including one paging record for each UE. The paging message may comprise a paging record list. The paging record list may comprise one or more paging records. Each paging record may comprise at least one of: a UE identity (ID) and access type. The UE identity may comprise S-TMSI or I-RNTI (resume identity). The access type may indicate whether the paging message originated due to a PDU sessions from non-3GPP access.
Cell selection may be required on transition from registration management (RM)-DEREGISTERED to RM-REGISTERED, from CM-IDLE to CM-CONNECTED and from CM-CONNECTED to CM-IDLE. the RM-DEREGISTERED state, the UE may be not registered with the network. The UE context in a core network entity (e.g., AMF/MME) may hold no valid location or routing information for the UE. The UE may be not reachable by the AMF. In the RM-REGISTERED state, the UE is registered with the network. In the RM-REGISTERED state, the UE can receive services that require registration with the network. A UE in CM-IDLE state may have no NAS signalling connection established with the core network entity (e.g., AMF/MME) (e.g., over N1/S1 interface). The UE may perform cell selection/cell reselection and PLMN selection. A UE in CM-CONNECTED state may have a NAS signalling connection with the core network entity (e.g., over N1/S1 interface). A NAS signalling connection may use an RRC connection between the UE and a base station (e.g., RAN) and an next generation application protocol (NGAP)/S1AP UE association between access network (AN) (e.g., AN of the base station) and the core network entity (e.g., AMF/MME).
Cell selection may be based on the following principles. The UE NAS layer may identify a selected PLMN and equivalent PLMNs. Cell selection may be based on cell defining SSB (CD-SSBs) located on synchronization raster: A UE may search the frequency (NR) bands and for each carrier frequency may identify the strongest cell as per the CD-SSB. The UE may then read cell system information broadcast to identify its PLMN(s): The UE may search each carrier in turn (“initial cell selection”) or make use of stored information to shorten the search (“stored information cell selection”). The UE may seek to identify a suitable cell; if the UE is not able to identify a suitable cell it seeks to identify an acceptable cell. When a suitable cell is found or if only an acceptable cell is found, the UE may camp on that cell and commence the cell reselection procedure: A suitable cell is one for which the measured cell attributes satisfy the cell selection criteria; the cell PLMN is the selected PLMN, registered or an equivalent PLMN; the cell is not barred or reserved and the cell is not part of a tracking area which is in the list of “forbidden tracking areas for roaming”; An acceptable cell is one for which the measured cell attributes satisfy the cell selection criteria and the cell is not barred.
On transition from an RRC connected state or RRC inactive state to an RRC idle state, a UE may camp on a cell as result of cell selection according to the frequency assigned by RRC in the state transition message. The UE may attempt to find a suitable cell in the manner described for stored information or initial cell selection above. If no suitable cell is found on any frequency or RAT, the UE may attempt to find an acceptable cell. In multi-beam operations, the cell quality may be derived amongst the beams corresponding to the same cell.
A UE in an RRC idle may perform cell reselection. The principles of the procedure are the following. Cell reselection may be based on CD-SSBs located on the synchronization raster. The UE may make measurements of attributes of the serving and neighbor cells to enable the reselection process: For the search and measurement of inter-frequency neighbouring cells, the carrier frequencies need to be indicated. Cell reselection may identify the cell that the UE should camp on. The cell reselection may be based on cell reselection criteria which involves measurements of the serving and neighbor cells: intra-frequency reselection is based on ranking of cells; inter-frequency reselection is based on absolute priorities where a UE tries to camp on the highest priority frequency available; an neighbor cell list (NCL) may be provided by a serving cell to handle specific cases for intra- and inter-frequency neighbouring cells; Black lists may be provided to prevent the UE from reselecting to specific intra- and inter-frequency neighbouring cells; White lists may be provided to request the UE to reselect to only specific intra- and inter-frequency neighbouring cells; Cell reselection may be speed dependent; Service specific prioritization. In multi-beam operations, the cell quality may be derived amongst the beams corresponding to the same cell.
A UE may perform one of two procedures such as initial cell selection and cell selection by leveraging stored information. The UE may perform the initial cell selection when the UE does not have stored cell information for the selected PLMN. Otherwise, the UE may perform the cell selection by leveraging stored information. For initial cell selection, a UE may scan all RF channels in the (NR) frequency bands according to its capabilities to find a suitable cell. Based on results of the scan, the UE may search for the strongest cell on each frequency. The UE may select a cell which is a suitable cell. For the cell selection by leveraging stored information, the UE may require stored information of frequencies and optionally also information on cell parameters from previously received measurement control information elements or from previously detected cells. Based on the stored information, the UE may search a suitable cell and select the suitable cell if the UE found the suitable cell. If the UE does not found the suitable cell, the UE may perform the initial cell selection.
A base station may configure cell selection criteria for cell selection. A UE may seek to identify a suitable cell for the cell selection. The suitable cell is one for which satisfies following conditions: (1) the measured cell attributes satisfy the cell selection criteria, (2) the cell PLMN is the selected PLMN, registered or an equivalent PLMN, (3) the cell is not barred or reserved, and (4) the cell is not part of tracking area which is in the list of “forbidden tracking areas for roaming”. An RRC layer in a UE may inform a NAS layer in the UE of cell selection and reselection result based on changes in received system information relevant for NAS. For example, the cell selection and reselection result may be a cell identity, tracking area code and a PLMN identity.
A UE-RRC layer may initiate an RRC connection establishment procedure, an RRC connection resume procedure, or an RRC connection re-establishment procedure. Based on initiating the RRC connection establishment procedure or the RRC connection resume procedure, the UE may perform one or more procedures where the one or more procedures comprise at least one of: performing a unified access control procedure (e.g., access barring check) for access attempt of the RRC establishment/resume procedure on a serving cell; applying default configurations parameters and configurations/parameters provided by SIB1, (e.g., based on the access attempt being allowed, applying default configurations and configurations/parameters provided by SIB1); performing sending a random access preamble to the serving cell, for example, based on the access attempt being allowed; sending an RRC request message to the serving cell (e.g., based on determining a reception of a random access response being successful, sending an RRC request message to the serving cell0; starting a timer based on sending the RRC request message; receiving an RRC response message or an RRC reject message from the serving cell (e.g., in response to the RRC request message); or sending an RRC complete message (e.g., in response to receiving the RRC response message, sending an RRC complete message). For the RRC connection re-establishment procedure, the UE may not perform the unified access procedure (e.g., access barring check) for access attempt of the RRC reestablishment procedure.
A base station (e.g., NG-RAN) may support overload and access control functionality such as RACH back off, RRC Connection Reject, RRC Connection Release and UE based access barring mechanisms. Unified access control framework applies to all UE states (e.g., an RRC idle, inactive and connected state). The base station may broadcast barring control information associated with access categories and access identities (in case of network sharing, the barring control information may be set individually for each PLMN). The UE may determine whether an access attempt is authorized based on the barring information broadcast for the selected PLMN, the selected access category and access identities for the access attempt. For NAS triggered requests, the UE-NAS layer may determine the access category and access identities. For AS triggered requests, the UE-RRC layer determines the access category while NAS determines the access identities. The base station may handle access attempts with establishment causes “emergency”, “mps-priority access” and “mcs priority access” (e.g., emergency calls, MPS, MCS subscribers) with high priority and respond with RRC Reject to these access attempts only in extreme network load conditions that may threaten the base station stability.
Based on initiating the RRC connection establishment procedure or the RRC connection resume procedure, the UE in an RRC inactive or idle state may perform or initiate access barring check (or a unified access control procedure) for access attempt of the RRC connection establishment procedure or the RRC connection resume procedure. Based on the performing or initiating the access barring check, the UE may determine the access category and access identities for access attempt. The UE may determine the access attempt being barred based on at least one of: timer T309 is running for the access category for the access attempt; and timer T302 is running, and the Access Category is neither ‘2’ nor ‘0’. The UE may determine the access attempt being allowed based on at least one of: the access Category is ‘0’; and system information block (system information block type 25) comprising unified access control (UAC) barring parameters is not broadcasted by a serving cell. The UE may determine the access attempt being barred based on at least one of: an establishment cause (e.g., for the access attempt) being other than emergency; access barring per RSRP parameter of the system information block comprising (or being set to) threshold 0 and the wireless device being in enhanced coverage; access barring per RSRP parameter of the system information block comprising (or being set to) threshold 1 and measured RSRP being less than a first entry in RSRP thresholds PRACH info list; the access barring per RSRP parameter of the system information block comprising (or being set to) threshold 2 and measured RSRP being less than a second entry in the RSRP thresholds PRACH info list; and the access barring per RSRP parameter of the system information block comprising (or being set to) threshold 3 and measured RSRP being less than a third entry in the RSRP thresholds PRACH info list.
The UE may determine the access attempt being allowed based on that system information block not comprising the UAC barring parameters for the access attempt. For example, the UE may determine the access attempt being allowed based on that system information block not comprising the UAC barring parameters for PLMN the UE selected and UAC barring parameters for common. The UE may determine the access attempt being allowed based on the UAC barring parameters for common not comprising the access category of the access attempt. The UAC barring parameters may comprise at least one of: UAC barring parameters per PLMN; and UAC barring parameters for common. The UE may perform access barring check for the access category of the access attempt based on the UAC barring parameters in the system information block. The UE may determine the access attempt being allowed based on corresponding bit of at least one of the access identities in the UAC barring parameters being zero. The UE may draw a first random number uniformly distributed in a range where the range is greater than equal to 0 and lower than 1.
The UE may determine the access attempt being allowed based on the first random number being lower than UAC barring factor in the UAC barring parameters. The UE may determine the access attempt being barred based on the first random number being greater than the UAC barring factor in the UAC barring parameters. In response to the determining the access attempt being barred, the UE may draw a second random number uniformly distributed in a range where the range is greater than equal to 0 and lower than 1. The UE may start barring timer T309 for the access category based on the second random number. When the barring timer T309 is running, the access attempt associated to the access category is barred (e.g., not allowed to transmit). Based on the barring timer T309 expiry, the UE may consider barring for the access category being alleviated. Based on the barring for the access category being alleviated, the UE may perform access barring check for the access category if the UE have access attempt for the access category.
Based on initiating the RRC connection reestablishment procedure, the UE may stop one or more barring timer T309 for all access categories if the one or more barring timer T309 is running. Based on stopping the one or more barring timer T309, the UE may determine barring for all access categories being alleviated. The UE may perform the RRC connection reestablishment procedure based on the barring for all access categories being alleviated. For example, the UE may send an RRC establishment request without barring based on the barring for all access categories being alleviated.
For initiating RRC connection establishment/resume/reestablishment procedure, the UE-RRC layer may use parameters in a received SIB1. The UE-RRC layer may use L1 parameter values and a time alignment timer in the SIB1. The UE-RRC layer may use UAC barring information in the SIB1 to perform the unified access control procedure. Based on the unified access control procedure, the UE-RRC layer may determine whether the access attempt of those RRC procedures is barred or allowed. Based on the determining the access attempt is allowed, the UE-RRC layer may determine send an RRC request message to a base station where the RRC request message may be an RRC setup request message, an RRC resume request message, or an RRC re-establishment message. The UE-NAS layer may or may not provide S-TMSI as a UE identity. The UE-RRC layer may set a UE identity in the RRC request message.
For the RRC setup request message, the UE in an RRC idle state may initiate an RRC connection establishment procedure. Based on initiating the RRC connection establishment procedure, the UE-RRC layer in an RRC idle state may set the UE identity to S-TMSI if the UE-NAS layer provides the S-TMSI. Otherwise, the UE-RRC layer in an RRC idle state may draw a 39-bit random value and set the UE identity to the random value. For the RRC resume request message, the UE-RRC layer in an RRC inactive or idle state may set the UE identity to resume identity stored. For the RRC reestablishment request message, the UE-RRC layer in an RRC connected state may set the UE identity to C-RNTI used in the source PCell. The UE-NAS layer may provide an establishment cause (e.g., UE-NAS layer). The UE-RRC layer may set the establishment cause for the RRC request message.
For the RRC resume request message, the UE in an RRC inactive may initiate an RRC connection resume procedure. The UE in an RRC idle state with a suspended RRC connection may initiate the RRC connection resume procedure. The UE may in an RRC inactive state or an RRC idle state may initiate the RRC connection procedure based on at least one of: resuming a (suspend) RRC connection; and performing/initiating UP small data transmission. Based on initiating the RRC connection resume procedure, the UE-RRC layer may restore stored configuration parameters and stored security keys from the stored UE inactive AS context. Based on the security keys, the UE-RRC layer in an RRC inactive or idle state may set a resume MAC-I value to the 16 least significant bits of the MAC-I calculated based on variable resume MAC input, security key of integrity protection for RRC layer in a UE inactive AS context, the previous configured integrity protection algorithm, and other security parameters (e.g., count, bearer, and direction). The variable resume MAC input may comprise at least one of: physical cell identity of a source cell; C-RNTI of the source cell; and cell identity of a target cell (e.g., a selected cell) where the cell identity is a cell identity in system information block (e.g., SIB1) of the target cell (e.g., the selected cell). Based on the security keys and next hop chaining count (NCC) value, the UE-RRC layer in an RRC inactive or idle state derive new security keys for integrity protection and ciphering, and configure lower layers (e.g., UE-PDCP layer) to apply them. The UE may have a stored NCC value and resume identity. The UE may receive an RRC release message with suspend indication (or suspend configuration parameters) where the RRC release message comprises at least one of: the resume identity; and the NCC value. The UE-RRC layer in an RRC inactive or idle state may re-establish PDCP entities for one or more bearers. The UE-RRC layer may resume one or more bearers. For example, based on resuming the RRC connection, the UE-RRC layer may resume SRB1. Based on performing the UP small data transmission, the UE-RRC layer may resume one or more SRB(s) and DRB(s). The UE-RRC layer in the RRC inactive or idle state may send an RRC resume request message to the base station where the RRC resume request message may comprise at least one of: the resume identity; the resume MAC-I; and resume cause.
For the RRC reestablishment request message, the UE in an RRC connected state may initiate an RRC connection reestablishment procedure. Based on initiating the RRC connection reestablishment procedure, the UE-RRC layer in an RRC connected state may contain the physical cell identity of the source PCell and a short MAC-I in the RRC reestablishment message. The UE-RRC layer in an RRC connected state may set the short MAC-I to the 16 east significant bits of the MAC-I calculated based on variable short MAC input, security key of integrity protection for RRC layer and the integrity protection algorithm, which was used in a source PCell or the PCell in which the trigger for the reestablishment occurred, and other security parameters (e.g., count, bearer and direction). The variable short MAC input may comprise at least one of: physical cell identity of the source cell; C-RNTI of a source cell; and cell identity of a target cell (e.g., a selected cell) where the cell identity is a cell identity in system information block (e.g., SIB1) of the target cell (e.g., the selected cell). The UE-RRC layer in an RRC connected state may re-establish PDCP entities and RLC entities for SRB1 and apply default SRB1 configuration parameters for SRB1. The UE-RRC layer in an RRC connected state may configure lower layers (e.g., PDCP layer) to suspend integrity protection and ciphering for SRB1 and resume SRB1.
A UE-RRC layer may send an RRC request message to lower layers (e.g., PDCP layer, RLC layer, MAC layer and/or PHY layer) for transmission where the RRC request message may be an RRC setup request message, an RRC resume request message, or an RRC re-establishment message.
A UE-RRC layer may receive an RRC setup message in response to an RRC resume request message or an RRC reestablishment request message. Based on the RRC setup message, the UE-RRC layer may discard any stored AS context, suspend configuration parameters and current AS security context. The UE-RRC layer may release radio resources for all established RBs except SRB0, including release of the RLC entities, of the associated PDCP entities and of SDAP. The UE-RRC layer may release the RRC configuration except for default L1 parameter values, default MAC cell group configuration and CCCH configuration. The UE-RRC layer may indicate to upper layers (e.g., NAS layer) fallback of the RRC connection. The UE-RRC layer may stop timer T380 if running where the timer T380 is periodic RAN-based Notification Area (RNA) update timer.
A UE-RRC layer may receive an RRC setup message in response to an RRC setup request message, an RRC resume request message or an RRC reestablishment request message. The RRC setup message may comprise a cell group configurations parameters and a radio bearer configuration parameters. The radio bearer configuration parameters may comprise at least one of signaling bearer configuration parameters, data radio bearer configuration parameters and/or security configuration parameters. The security configuration parameters may comprise security algorithm configuration parameters and key to use indication indicating whether the radio bearer configuration parameters are using master key or secondary key. The signaling radio bearer configuration parameters may comprise one or more signaling radio bearer configuration parameters. Each signaling radio configuration parameters may comprise at least one of SRB identity, PDCP configuration parameters, reestablish PDCP indication and/or discard PDCP indication. The data radio bearer configuration parameters may comprise one or more data radio bearer configuration parameters. Each data radio configuration parameters may comprise at least one of DRB identity, PDCP configuration parameters, SDAP configuration parameters, reestablish PDCP indication and/or recover PDCP indication. The radio bearer configuration in the RRC setup message may comprise signaling radio configuration parameters for SIB1. Based on the RRC setup message, the UE-RRC layer may establish SRB1. Based on the RRC setup message, the UE-RRC layer may perform a cell group configuration or radio bearer configuration. The UE-RRC layer may stop a barring timer and wait timer for the cell sending the RRC setup message. Based on receiving the RRC setup message, the UE-RRC layer may perform one or more of the following: transitioning to RRC connected state; stopping a cell re-selection procedure; considering the current cell sending the RRC setup message to be the PCell; or/and sending an RRC setup complete message by setting the content of the RRC setup complete message.
A UE-RRC layer may receive an RRC resume message in response to an RRC resume request message. Based on the RRC resume message, the UE-RRC layer may discard a UE inactive AS context and release a suspend configuration parameters except RNA notification area information. The RRC resume message may comprise at least one of: radio bearer configuration parameters; cell group configuration parameters; measurement configuration parameters; sk counter for AS security; an first indication to request idle/inactive measurement results; an second indication to restore secondary cells (SCells) of master cell group (MCG); a third indication to restore secondary cell group (SCG); and SCG configuration parameters; Based on the RRC resume message, the UE-RRC layer may perform a procedure to configure or restore configuration parameters (e.g., a cell group configuration, a radio bearer configuration and/or SCG configuration); security key update procedure; and/or measurement (configuration) procedure. Based on receiving the RRC resume message, the UE-RRC layer may perform one or more of the following: indicating upper layers (e.g., NAS layer) that the suspended RRC connection has been resumed; resuming SRB2, all DRBs and measurements; entering RRC connected state; stopping a cell re-selection procedure; considering the current cell sending the RRC resume message to be the PCell; or/and sending an RRC resume complete message by setting the content of the RRC resume complete message.
Cell group configuration parameters may be used to configure a master cell group (MCG) or secondary cell group (SCG). If the cell group configuration parameters are used to configure the MCG, the cell group configuration parameters are master cell group configuration parameters. If the cell group configuration parameters are used to configure the SCG, the cell group configuration parameters are secondary cell group configuration parameters. A cell group comprises of one MAC entity, a set of logical channels with associated RLC entities and of a primary cell (SpCell) and one or more secondary cells (SCells). The cell group configuration parameters (e.g., master cell group configuration parameters or secondary cell group configuration parameters) may comprise at least one of RLC bearer configuration parameters for the cell group, MAC cell group configuration parameters for the cell group, physical cell group configuration parameters for the cell group, SpCell configuration parameters for the cell group or SCell configuration parameters for the cell group. The MAC cell group configuration parameters may comprise MAC parameters for a cell group where the MAC parameters may comprise at least DRX parameters. The physical cell group configuration parameters may comprise cell group specific L1 (layer 1) parameters.
The special cell (SpCell) may comprise a primary cell (PCell) of an MCG or a primary SCG cell (PSCell) of a SCG. The SpCell configuration parameters may comprise serving cell specific MAC and PHY parameters for a SpCell. The MR-DC configuration parameters may comprise at least one of SRB3 configuration parameters, measurement configuration parameter for SCG, SCG configuration parameters.
Cell group configuration parameters may comprise at least one of RLC bearer configuration parameters, MAC cell group configuration parameters, physical cell group configuration parameters, SpCell configuration parameters for the first cell group or SCell configuration parameters for other cells of the second base station. The SpCell configuration parameter may comprise at least one of radio link failure timer and constraints, radio link monitoring in sync out of sync threshold, and/or serving cell configuration parameters of the first cell. The serving cell configuration parameters may comprise at least one of: downlink BWP configuration parameters; uplink configuration parameters; uplink configuration parameters for supplement uplink carrier (SUL); PDCCH parameters applicable across for all BWPs of a serving cell; PDSCH parameters applicable across for all BWPs of a serving cell; CSI measurement configuration parameters; SCell deactivation timer; cross carrier scheduling configuration parameters for a serving cell; timing advance group (TAG) identity (ID) of a serving cell; path loss reference linking indicating whether the UE shall apply as pathloss reference either the downlink of SpCell or SCell for this uplink; serving cell measurement configuration parameters; channel access configuration parameters for access procedures of operation with shared spectrum channel access;
The CSI measurement configuration parameters may be to configure CSI-RS (reference signals) belonging to the serving cell, channel state information report to configure CSI-RS (reference signals) belonging to the serving cell and channel state information reports on PUSCH triggered by DCI received on the serving cell.
In an example, the downlink BWP configuration parameters may be used to configure dedicated (UE specific) parameters of one or more downlink BWPs. The one or more downlink BWPs may comprise at least one of an initial downlink BWP, a default downlink BWP and a first active downlink BWP. The downlink BWP configuration parameters may comprise at least one of: configuration parameters for the one or more downlink BWPs; one or more downlink BWP IDs for the one or more downlink BWPs; and BWP inactivity timer. The configuration parameters for a downlink BWP may comprise at least one of: PDCCH configuration parameters for the downlink BWP; PDSCH configuration parameters for the downlink BWP; semi-persistent scheduling (SPS) configuration parameters for the downlink BWP; beam failure recovery SCell configuration parameters of candidate RS; and/or radio link monitoring configuration parameters for detecting cell- and beam radio link failure occasions for the downlink BWP. The one or more downlink BWP IDs may comprise at least one of an initial downlink BWP ID, a default downlink BWP identity (ID) and a first active downlink BWP ID.
In an example, the uplink configuration parameters may be uplink configuration parameters for normal uplink carrier (not supplementary uplink carrier). The uplink configuration parameters (or the uplink configuration parameters for SUL) may be used to configure dedicated (UE specific) parameters of one or more uplink BWPs. The one or more uplink BWPs may comprise at least one of an initial uplink BWP and a first active uplink BWP. The uplink BWP configuration parameters may comprise at least one of: configuration parameters for the one or more uplink BWPs; one or more uplink BWP IDs for the one or more uplink BWPs; PUSCH parameters common across the UE's BWPs of a serving cell; SRS carrier switching information; and power control configuration parameters. The configuration parameters for an uplink BWP may comprise at least one of: one or more PUCCH configuration parameters for the uplink BWP; PUSCH configuration parameters for the uplink BWP; one or more configured uplink grant configuration parameters for the uplink BWP; SRS configuration parameters for the uplink BWP; beam failure recovery configuration parameters for the uplink BWP; and/or cyclic prefix (CP) extension parameters for the uplink BWP.
The one or more uplink BWP IDs may comprise at least one of an initial uplink BWP ID (e.g., the initial uplink BWP ID=0) and/or a first active uplink BWP ID. The SRS carrier switching information may be used to configure for SRS carrier switching when PUSCH is not configured and independent SRS power control from that of PUSCH. The power control configuration parameters may comprise at least one of the power control configuration parameters for PUSCH, power configuration control parameters for PUCCH and power control parameters for SRS.
A UE-RRC layer in an RRC inactive or idle state may receive an RRC reject message in response to an RRC setup request message or an RRC resume request message. The RRC reject message may contain a wait timer. Based on the wait timer, the UE-RRC layer may start timer T302, with the timer value set to the wait timer. Based on the RRC reject message, the UE-RRC layer may inform upper layers (e.g., UE-NAS layer) about the failure to setup an RRC connection or resume an RRC connection. The UE-RRC layer may reset MAC and release the default MAC cell group configuration. Based on the RRC Reject received in response to a request from upper layers, the UE-RRC layer may inform the upper layer (e.g., NAS layer) that access barring is applicable for all access categories except categories ‘0’ and ‘2’.
A UE-RRC layer in an RRC inactive or idle state may receive an RRC reject message in response to an RRC resume request message. Based on the RRC reject message, The UE-RRC layer may discard current security keys. The UE-RRC layer may re-suspend the RRC connection. The UE-RRC layer may set pending rna update value to true if resume is triggered due to an RNA update.
A UE-RRC layer in an RRC inactive or idle state may perform a cell (re) selection procedure while performing an RRC procedure to establish an RRC connection. Based on cell selection or cell reselection, the UE-RRC layer may change a cell on the UE camped and stop the RRC procedure. The UE-RRC layer may inform upper layers (e.g., NAS layer) about the failure of the RRC procedure.
A UE in an RRC connected state may detect a failure of a connection with a base station. The UE in the RRC connected state may activate AS security with the base station before the detecting the failure. The failure comprises at least one of: a radio link failure (RLF); a reconfiguration with sync failure; a mobility failure from new radio (NR); an integrity check failure indication from lower layers (e.g., PDCP layer) concerning signaling radio bearer 1 (SRB1) or signaling radio bearer 2 (SRB2); or an RRC connection reconfiguration failure.
The radio link failure may be a radio link failure of a primary cell of the base station. The base station may send a reconfiguration with sync in an RRC message to the UE in RRC connected state. The reconfiguration with sync may comprise a reconfiguration timer (e.g., T304). Based on receiving the reconfiguration sync, the UE may start the reconfiguration timer and perform the reconfiguration with sync (e.g., handover). Based on expiry of the reconfiguration timer, the UE determine the reconfiguration sync failure. A base station may send mobility from NR command message to the UE in RRC connected state. Based on receiving the mobility from NR command message, the UE may perform to handover from NR to a cell using other RAT (e.g., E-UTRA). The UE may determine the mobility failure from NR based on at least one of conditions being met: if the UE does not succeed in establishing the connection to the target radio access technology; or if the UE is unable to comply with any part of the configuration included in the mobility from NR command message; or if there is a protocol error in the inter RAT information included in the mobility from NR message.
Based on detecting the failure, the UE in the RRC connected state may initiate an RRC connection reestablishment procedure. Based on initiating the RRC connection reestablishment procedure, the UE may start a timer T311, suspend all radio bearers except for SRB0, reset MAC (layer). Based on initiating the RRC connection reestablishment procedure, the UE in the RRC connected state may release MCG SCells, release special cell (SpCell) configuration parameters and multi-radio dual connectivity (MR-DC) related configuration parameters. For example, based on initiating the RRC connection reestablishment procedure, the UE may release master cell group configuration parameters.
Based on initiating the RRC connection reestablishment procedure, the UE in the RRC connected state may perform a cell selection procedure. Based on the cell selection procedure, the UE may select a cell based on a signal quality of the cell exceeding a threshold. The UE in the RRC connected state may select a cell based on a signal quality of the cell exceeding a threshold. The UE may determine, based on a cell selection procedure, the selected cell exceeding the threshold. The signal quality comprises at least one of: a reference signal received power; a received signal strength indicator; a reference signal received quality; or a signal to interference plus noise ratio.
Based on selecting a suitable cell, the UE in the RRC connected state may stop the timer 311 and start a timer T301. Based on selecting the suitable cell, the UE in the RRC connected state may stop a barring timer T390 for all access categories. Based on stopping the barring timer T390, the UE in the RRC connected state may consider a barring for all access category to be alleviated for the cell. Based on selecting the cell, the UE in the RRC connected state may apply the default L1 parameter values except for the parameters provided in SIB1, apply the default MAC cell group configuration, apply the CCCH configuration, apply a timer alignment timer in SIB1 and initiate transmission of the RRC reestablishment request message.
The UE in the RRC connected state may stop the timer T301 based on reception of an RRC response message in response to the RRC reestablishment request message. The RRC response message may comprise at least one of RRC reestablishment message or RRC setup message or RRC reestablishment reject message. The UE in the RRC connected state may stop the timer T301 when the selected cell becomes unsuitable.
Based on the cell selection procedure triggered by initiating the RRC connection reestablishment procedure, the UE in the RRC connected state may select an inter-RAT cell. Based on selecting an inter-RAT cell, the UE (UE-AS layer) in the RRC connected state may transition to RRC IDLE state and may provide a release cause ‘RRC connection failure’ to upper layers (UE-NAS layer) of the UE.
Based on initiating the transmission of the RRC reestablishment request message, the UE in the RRC connected state may send the RRC reestablishment request message. The RRC reestablishment request message may comprise at least one of C-RNTI used in the source PCell, a physical cell identity (PCI) of the source PCell, short MAC-I or a reestablishment cause. The reestablishment cause may comprise at least one of reconfiguration failure, handover failure or other failure.
Based on initiating the transmission of the RRC reestablishment request message, the UE (RRC layer) in the RRC connected state may re-establish PDCP for SRB1, re-establish RLC for SRB1, apply default SRB configurations for SRB1, configure lower layers (PDCP layer) to suspend integrity protection and ciphering for SRB1, resume SRB1 and submit the RRC reestablishment request message to lower layers (PDCP layer) for transmission. Based on submitting the RRC reestablishment request message to lower layers, the UE in the RRC connected state may send the RRC reestablishment request message to a target base station via the cell selected based on the cell selection procedure wherein the target base station may or may not be the source base station.
Based on expiry of the timer T311 or T301, the UE (UE-AS layer) may transition to an RRC idle state and may provide a release cause ‘RRC connection failure’ to upper layers (UE-NAS layer) of the UE.
Based on receiving the release cause ‘RRC connection failure’, the UE (UE-NAS layer) in the RRC idle state may perform a NAS signaling connection recovery procedure when the UE does not have signaling pending and user data pending. Based on performing the NAS signaling connection recovery procedure, the UE in the RRC idle state may initiate the registration procedure by sending a registration request message to the AMF.
Based on receiving the release cause ‘RRC connection failure’, the UE (UE-NAS layer) in the RRC idle state may perform a service request procedure by sending a service request message to the AMF when the UE has signaling pending or user data pending.
Based on receiving the RRC reestablishment request message, the target base station may check whether the UE context of the UE is locally available. Based on the UE context being not locally available, the target base station may perform a retrieve UE context procedure by sending a retrieve UE context request message to the source base station (the last serving base station) of the UE.
For RRC connection reestablishment procedure, the retrieve UE context request message may comprise at least one of: a UE context ID; integrity protection parameters; or a new cell identifier. The UE context ID may comprise at least one of: C-RNTI contained the RRC reestablishment request message; and a PCI of the source PCell (the last serving PCell). The integrity protection parameters for the RRC reestablishment procedure may be the short MAC-I. The new cell identifier may be an identifier of the target cell where the target cell is a cell where the RRC connection has been requested to be re-established. The new cell identifier is a cell identity in system information block (e.g., SIB1) of the target cell (e.g., the selected cell).
For the RRC connection reestablishment procedure, based on receiving the retrieve UE context request message, the source base station may check the retrieve UE context request message. If the source base station is able to identify the UE context by means of the UE context ID, and to successfully verify the UE by means of the integrity protection contained in the retrieve UE context request message, and decides to provide the UE context to the target base station, the source base station may respond to the target base station with a retrieve UE context response message. If the source base station is not able to identify the UE context by means of the UE context ID, or if the integrity protection contained in the retrieve UE context request message is not valid, the source base station may respond to the target base station with a retrieve UE context failure message.
For the RRC connection reestablishment procedure, the retrieve UE context response message may comprise at least one of Xn application protocol (XnAP) ID of the target base station, XnAP ID of the source base station, globally unique AMF identifier (GUAMI) or UE context information (e.g., UE context information retrieve UE context response). The UE context information may comprise at least one of a NG-C UE associated signaling reference, UE security capabilities, AS security information, UE aggregate maximum bit rate, PDU session to be setup list, RRC context, mobility restriction list or index to RAT/frequency selection priority. The NG-C UE associated signaling reference may be a NG application protocol ID allocated at the AMF of the UE on the NG-C connection with the source base station. The AS security information may comprise a security key of a base station (KgNB) and next hop chaining count (NCC) value. The PDU session to be setup list may comprise PDU session resource related information used at UE context in the source base station. The PDU session resource related information may comprise a PDU session ID, a PDU session resource aggregate maximum bitrate, a security indication, a PDU session type or QoS flows to be setup list. The security indication may comprise a user plane integrity protection indication and confidentiality protection indication which indicates the requirements on user plane (UP) integrity protection and ciphering for the corresponding PDU session, respectively. The security indication may also comprise at least one of an indication whether UP integrity protection is applied for the PDU session, an indication whether UP ciphering is applied for the PDU session, and the maximum integrity protected data rate values (uplink and downlink) per UE for integrity protected DRBs. The PDU session type may indicate at least one of internet protocol version 4 (IPv4), IPv6, IPv4v6, ethernet or unstructured. The QoS flow to be setup list may comprise at least one of QoS flow identifier, QoS flow level QoS parameters (the QoS Parameters to be applied to a QoS flow) or bearer identity.
For the RRC connection reestablishment procedure, the retrieve UE context failure message may comprise at least XnAP ID of the target base station and a cause value.
For the RRC connection reestablishment procedure, based on receiving the retrieve UE context response message, the target base station may send an RRC reestablishment message to the UE. The RRC reestablishment message may comprise at least a network hop chaining count (NCC) value.
Based on receiving the RRC reestablishment message, the UE may derive a new security key of a base station (KgNB) based on at least one of current KgNB or next hop (NH) parameters associated to the NCC value. Based on the new security key of the base station and a previously configured integrity protection algorithm, the UE may derive a security key for integrity protection of an RRC signaling (KRRCInt) and a security key for integrity protection of user plane (UP) data (KUPInt). Based on the new security key of the base station and a previously configured ciphering algorithm, the UE may derive a security key for ciphering of an RRC signaling (KRRCenc) and a security key for ciphering of user plane (UP) data (KUPenc). Based on the KRRCint, and the previously configured integrity protection algorithm, the UE may verify the integrity protection of the RRC reestablishment message. Based on the verifying being failed, the UE (UE-AS layer) may go to RRC IDLE state and may provide a release cause ‘RRC connection failure’ to upper layers (UE-NAS layer) of the UE. Based on the verifying being successful, the UE may configure to resume integrity protection for SRB1 based on the previously configured integrity protection algorithm and the KRRCint and configure to resume ciphering for SRB1 based on the previously configured ciphering algorithm and KRRCenc. The UE may send an RRC reestablishment complete message to the target base station.
Based on receiving the retrieve UE context failure message, the target base station may send an RRC release message to the UE. For example, based on the retrieve UE context failure message comprising the RRC release message, the target base station may send the RRC release message to the UE. Based on receiving the retrieve UE context failure message, the target base station may send an RRC setup message or an RRC reject message. Based on receiving the retrieve UE context failure message, the target base station may not send any response message to the UE.
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A base station may initiate an RRC connection release procedure to transit an RRC state of a UE from RRC connected state to RRC idle state, from an RRC connected state to RRC inactive state, from RRC inactive state back to RRC inactive state when the UE tries to resume, or from RRC inactive state to RRC idle state when the UE tries to resume. The RRC connection procedure may also be used to release an RRC connection of the UE and redirect a UE to another frequency. The base station may send to a UE the RRC release message comprising suspend configuration parameters. Based on the RRC release message, the UE may suspend an RRC connection. The UE may transition an RRC state of the UE to and RRC inactive state or an RRC idle state. The suspend configuration parameters may comprise at least one of a resume identity, RNA configuration, RAN paging cycle, or network hop chaining count (NCC) value where the RNA configuration may comprise RNA notification area information, or periodic RNA update timer value (e.g., T380 value). The base station may use the resume identity (e.g., inactive-RNTI (I-RNTI) to identify the UE context when the UE is in RRC inactive state.
If the base station has a fresh and unused pair of {NCC, next hop (NH)}, the base station may include the NCC in the suspend configuration parameters. Otherwise, the base station may include the same NCC associated with the current KgNB in the suspend configuration parameters. The NCC is used for AS security. The base station may delete the current AS keys (e.g., KRRCenc, KUPenc), and KUPint after sending the RRC release message comprising the suspend configuration parameters to the UE but may keep the current AS key KRRCint. If the sent NCC value is fresh and belongs to an unused pair of {NCC, NH}, the base station may save the pair of {NCC, NH} in the current UE AS security context and may delete the current AS key KgNB. If the sent NCC value is equal to the NCC value associated with the current KgNB, the base station may keep the current AS key KgNB and NCC. The base station may store the sent resume identity together with the current UE context including the remainder of the AS security context.
Upon receiving the RRC release message comprising the suspend configuration parameters from the base station, the UE may verify that the integrity of the received RRC release message comprising the suspend configuration parameters is correct by checking PDCP MAC-I. If this verification is successful, then the UE may take the received NCC value and save it as stored NCC with the current UE context. The UE may delete the current AS keys KRRCenc, KUPenc, and KUPint, but keep the current AS key KRRCint key. If the stored NCC value is different from the NCC value associated with the current KgNB, the UE may delete the current AS key KgNB. If the stored NCC is equal to the NCC value associated with the current KgNB, the UE shall keep the current AS key KgNB. The UE may store the received resume identity together with the current UE context including the remainder of the AS security context, for the next state transition.
Based on receiving the RRC release message comprising the suspend configuration parameters, the UE may reset MAC, release the default MAC cell group configuration, re-establish RLC entities for one or more bearers. Based on receiving the RRC release message comprising suspend configuration parameters, the UE may store in the UE inactive AS context current configuration parameters and current security keys. For example, the UE may store some of the current configuration parameters. The stored current configuration parameters may comprise a robust header compression (ROHC) state, quality of service (QOS) flow to DRB mapping rules, the C-RNTI used in the source PCell, the global cell identity and the physical cell identity of the source PCell, and all other parameters configured except for the ones within reconfiguration with sync and serving cell configuration common parameters in SIB. The stored security keys may comprise at least one of KgNB and KRRCint. The serving cell configuration common parameters in SIB may be used to configure cell specific parameters of a UE's serving cell in SIB1. Based on receiving the RRC release message comprising the suspend configuration parameters, the UE may suspend all SRB(s) and DRB(s) except for SRB0. Based on receiving the RRC release message comprising suspend configuration parameters, the UE may start a timer T380, enter RRC inactive state, perform cell selection procedure.
The UE in RRC inactive state may initiate an RRC connection resume procedure. For example, based on having data or signaling to transmit, or receiving RAN paging message, the UE in RRC inactive state may initiate the RRC connection resume procedure. Based on initiating the RRC connection resume procedure, the UE may select access category based on triggering condition of the RRC connection resume procedure and perform unified access control procedure based on the access category. Based on the unified access control procedure, the UE may consider access attempt for the RRC connection resume procedure as allowed. Based on considering the access attempt as allowed, the UE may apply the default L1 parameter values as specified in corresponding physical layer specifications, except for the parameters for which values are provided in SIB1, apply the default SRB1 configuration, apply the CCCH configuration, apply the time alignment timer common included in SIB1, apply the default MAC cell group configuration, start a timer T319 and initiate transmission of an RRC resume request message.
Based on initiating the transmission of the RRC resume request message, the UE may set the contents of the RRC resume request message. The RRC resume request message may comprise at least one of resume identity, resume MAC-I or resume cause. The resume cause may comprise at least one of emergency, high priority access, mt access, mo signalling, mo data, mo voice call, mo sms, ran update, mps priority access, mcs priority access.
Based on initiating the transmission of the RRC resume request message, the UE may restore the stored configuration parameters and the stored security keys from the (stored) UE inactive AS context except for the master cell group configuration parameters, MR-DC related configuration parameters (e.g., secondary cell group configuration parameters) and PDCP configuration parameters. The configuration parameter may comprise at least one of the C-RNTI used in the source PCell, the global cell identity and the physical cell identity of the source PCell, and all other parameters configured except for the ones within reconfiguration with sync and serving cell configuration common parameters in SIB. Based on current (restored) KgNB or next hop (NH) parameters associated to the stored NCC value, the UE may derive a new key of a base station (KgNB). Based on the new key of the base station, the UE may derive security keys for integrity protection and ciphering of RRC signalling (e.g., KRRCenc and KRRCint respectively) and security keys for integrity protection and ciphering of user plane data (e.g., KUPint and the KUPenc respectively). Based on configured algorithm and the KRRCint and KUPint, the UE may configure lower layers (e.g., PDCP layer) to apply integrity protection for all radio bearers except SRB0. Based on configured algorithm and the K RRCenc and the KUPenc, the UE may configure lower layers (e.g., PDCP layer) to apply ciphering for all radio bearers except SRB0.
Based on initiating the transmission of the RRC resume request message, the UE may re-establish PDCP entities for one or more bearers, resume the one or more bearers and submit the RRC resume request message to lower layers where the lower layers may comprise at least one of PDCP layer, RLC layer, MAC layer or physical (PHY) layer.
A target base station may receive the RRC resume request message. Based on receiving the RRC resume request message, the target base station may check whether the UE context of the UE is locally available. Based on the UE context being not locally available, the target base station may perform the retrieve UE context procedure by sending the retrieve UE context request message to the source base station (the last serving base station) of the UE. The retrieve UE context request message may comprise at least one of a UE context ID, integrity protection parameters, a new cell identifier or the resume cause where the resume cause is in the RRC resume request message.
For the RRC connection resume procedure, based on receiving the retrieve UE context request message, the source base station may check the retrieve UE context request message. If the source base station is able to identify the UE context by means of the UE context ID, and to successfully verify the UE by means of the integrity protection contained in the retrieve UE context request message, and decides to provide the UE context to the target base station, the source base station may respond to the target base station with the retrieve UE context response message. If the source base station is not able to identify the UE context by means of the UE context ID, or if the integrity protection contained in the retrieve UE context request message is not valid, or, if the source base station decides not to provide the UE context to the target base station, the source base station may respond to the target base station with a retrieve UE context failure message.
For the RRC connection resume procedure, the retrieve UE context failure message may comprise at least XnAP ID of the target base station, an RRC release message or a cause value.
For the RRC connection resume procedure, based on receiving the retrieve UE context response message, the target base station may send an RRC resume message to the UE. The RRC resume message may comprise at least one of radio bearer configuration parameters, cell group configuration parameters for MCG and/or SCG, measurement configuration parameters or sk counter where the sk counter is used to derive a security key of secondary base station based on KgNB.
Based on receiving the retrieve UE context failure message, the target base station may send an RRC release message to the UE. For example, based on the retrieve UE context failure message comprising the RRC release message, the target base station may send the RRC release message to the UE. Based on receiving the retrieve UE context failure message, the target base station may send an RRC setup message or an RRC reject message. Based on receiving the retrieve UE context failure message, the target base station may not send any response message to the UE.
Based on receiving the RRC resume message, the UE may stop the timer T319 and T380. Based on receiving the RRC resume message, the UE may restore mater cell group configuration parameters, secondary cell group configuration parameters and PDCP configuration parameters in the UE inactive AS context. Based on restoring the master cell group configuration parameter and/or the secondary cell group configuration parameters, the UE may configure SCells of MCG and/or SCG by configuring lower layers to consider the restored MCG and/or SCG SCells to be in deactivated state, discard the UE inactive AS context and release the suspend configuration parameters.
Based on receiving the cell group configuration parameters in the RRC resume message, the UE may perform cell group configuration of MCG and/or SCG. Based on receiving the radio bearer configuration parameters in the RRC resume message, the UE may perform radio bearer configuration. Based on the sk counter in the RRC resume message, the UE may perform to update the security key of secondary base station.
A UE may remain in CM-CONNECTED and move within an area configured by the base station without notifying the base station when the UE is in RRC inactive state where the area is an RNA. In RRC inactive state, a last serving base station may keep the UE context and the UE-associated NG connection with the serving AMF and UPF. Based on received downlink data from the UPF or downlink UE-associated signaling from the AMF while the UE is in RRC inactive state, the last serving base station may page in the cells corresponding to the RNA and may send RAN Paging via an Xn interface to neighbor base station(s) if the RNA includes cells of neighbor base station(s).
An AMF may provide to the base station a core network assistance information to assist the base station's decision whether a UE can be sent to RRC inactive state. The core network assistance information may include the registration area configured for the UE, the periodic registration update timer, a UE identity index value, the UE specific DRX, an indication if the UE is configured with mobile initiated connection only (MICO) mode by the AMF, or the expected UE behavior. The base station may use the UE specific DRX and the UE identity index value to determine a paging occasion for RAN paging. The base station may use periodic registration update timer to configure periodic RNA update timer (e.g., a timer T380). The base station may use an expected UE behavior to assist the UE RRC state transition decision
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A base station may send an RRC release message to a UE to release an RRC connection of the UE. Based on the RRC release message, the UE may release established radio bearers as well as all radio resources.
A base station may send an RRC release message to a UE to suspend the RRC connection. Based on the RRC release message, the UE may suspend all radio bearers except for signaling radio bearer 0 (SRB0). The RRC release message may comprise suspend configuration parameters. The suspend configuration parameters may comprise next hop chaining count (NCC) and resume identity (e.g., ID or identifier).
The base station may send an RRC release message to transit a UE in an RRC connected state to an RRC idle state; or to transit a UE in an RRC connected state to an RRC inactive state; or to transit a UE in an RRC inactive state back to an RRC inactive state when the UE tries to resume; or to transit a UE in an RRC inactive state to an RRC idle state when the UE tries to resume.
The base station may send an RRC release message to redirect a UE to another frequency.
A UE may receive an RRC release message from the base station of serving cell (or PCell). Based on the RRC release message, the UE may performs UE actions for the RRC release message from the base station. The UE may delay the UE actions for the RRC release message a period of time (e.g., 60 ms) from the moment the RRC release message was received or when the receipt of the RRC release message was successfully acknowledged. The UE may send HARQ acknowledgments to the base station for acknowledgments of the RRC release message. Based on a RLC protocol data unit (PDU) comprising the RRC release message and the RLC PDU comprising poll bit, the UE may send a RLC message (e.g., a status report) to the base station for acknowledgments of the RRC release message.
The UE actions for the RRC release message from the base station may comprise at least one of: suspending an RRC connection; releasing an RRC connection; cell (re) selection procedure; and/or idle/inactive measurements.
The RRC release message from the base station may comprise the suspend configuration parameters. Based on the suspend configuration parameters, the UE may perform the suspending of an RRC connection. The suspending an RRC connection may comprise at least one of: medium access control (MAC) reset (or resetting MAC); releasing default MAC cell group configuration; re-establishing RLC entities for one or more radio bearers; storing current configuration parameters and current security keys; suspending one or more bearers where the bearers comprises signaling radio bearer and data radio bearer; and/or transitioning an RRC idle state or an RRC inactive state.
For example, the suspended configuration parameters may further comprise RNA configuration parameters. Based on the RNA configuration parameters, the UE may transition to an RRC inactive state. For example, based on the suspend configuration parameters not comprising the RNA configuration parameters, the UE may transition to an RRC idle state. For example, the RRC release message comprising the suspend configuration parameters may comprise an indication transitioning to an RRC inactive state. Based on the indication, the UE may transition to an RRC inactive state. For example, based on the RRC release message not comprising the indication, the UE may transition to an RRC idle state.
Based on the MAC reset, the UE may perform to at least one of: stop all timers running in the UE-MAC layer; consider all time alignment timers as expired; set new data indicators (NDIs) for all uplink HARQ processes to the value 0; stop, ongoing RACH procedure; discard explicitly signaled contention-free Random Access Resources, if any; flush Msg 3 buffer; cancel, triggered scheduling request procedure; cancel, triggered buffer status reporting procedure; cancel, triggered power headroom reporting procedure; flush the soft buffers for all DL HARQ processes; for each DL HARQ process, consider the next received transmission for a TB as the very first transmission; and/or release, temporary C-RNTI.
Based on the considering the time alignment timers as expired, the UE may perform at least one of: flush all HARQ buffers for all serving cells; notify RRC to release PUCCH for all Serving cells, if configured; notify RRC to release SRS for all Serving Cells, if configured; clear any configured downlink assignments and configured uplink grants; clear any PUSCH resource for semi-persistent CSI reporting; and/or consider all running time alignment timers as expired.
The default MAC cell group configuration parameters may comprise buffer status report (BSR) configuration parameters (e.g., BSR timers) for a cell group of the base station and power headroom reporting (PHR) configuration parameters (e.g., PHR timers or PHR transmission power factor change parameter) for the cell group of the base station.
The re-establishing RLC entities may comprise at least one of: discarding all RLC SDUs, RLC SDU segments, and RLC PDUs, if any; stopping and resetting all timers of the RLC entities; and resetting all state variables of the RLC entities to their initial values.
The RRC release message from the base station may not comprise the suspend configuration parameters. Based on the RRC message not comprising the suspend configuration parameters, the UE may perform the releasing of an RRC connection. The releasing an RRC connection may comprise at least one of: MAC reset (or resetting MAC); discarding the stored configuration parameters and stored security keys (or discarding the stored UE inactive AS context); releasing the suspend configuration parameters; releasing all radio resources, including release of RLC entity, MAC configuration and associated PDCP entity and SDAP for all established radio bearers; and/or transitioning to an RRC idle state.
The RRC release message may comprises an RRC early data complete message.
The layers may be associated with an open system interconnection (OSI) model of computer networking functionality. In the OSI model, layer 1 may correspond to the bottom layer, with higher layers on top of the bottom layer. Layer 1 may correspond to a physical layer, which is concerned with the physical infrastructure used for transfer of signals (for example, cables, fiber optics, and/or radio frequency transceivers). In New Radio (NR), layer 1 may comprise a physical layer (PHY). Layer 2 may correspond to a data link layer. Layer 2 may be concerned with packaging of data (into, e.g., data frames) for transfer, between nodes of the network, using the physical infrastructure of layer 1. In NR, layer 2 may comprise a media access control layer (MAC), a radio link control layer (RLC), a packet data convergence layer (PDCP), and a service data application protocol layer (SDAP).
Layer 3 may correspond to a network layer. Layer 3 may be concerned with routing of the data which has been packaged in layer 2. Layer 3 may handle prioritization of data and traffic avoidance. In NR, layer 3 may comprise a radio resource control layer (RRC) and a non-access stratum layer (NAS). Layers 4 through 7 may correspond to a transport layer, a session layer, a presentation layer, and an application layer. The application layer interacts with an end user to provide data associated with an application. In an example, an end user implementing the application may generate data associated with the application and initiate sending of that information to a targeted data network (e.g., the Internet, an application server, etc.). Starting at the application layer, each layer in the OSI model may manipulate and/or repackage the information and deliver it to a lower layer. At the lowest layer, the manipulated and/or repackaged information may be exchanged via physical infrastructure (for example, electrically, optically, and/or electromagnetically). As it approaches the targeted data network, the information will be unpackaged and provided to higher and higher layers, until it once again reaches the application layer in a form that is usable by the targeted data network (e.g., the same form in which it was provided by the end user). To respond to the end user, the data network may perform this procedure in reverse.
The NAS may be concerned with the non-access stratum, in particular, communication between the UE 1901 and the core network (e.g., the AMF 1912). Lower layers may be concerned with the access stratum, for example, communication between the UE 1901 and the gNB 1902. Messages sent between the UE 1901 and the core network may be referred to as NAS messages. In an example, a NAS message may be relayed by the gNB 1902, but the content of the NAS message (e.g., information elements of the NAS message) may not be visible to the gNB 1902.
PDCP 1961 and PDCP 1962 may perform header compression and/or decompression. Header compression may reduce the amount of data transmitted over the physical layer. The PDCP 1961 and PDCP 1962 may perform ciphering and/or deciphering. Ciphering may reduce unauthorized decoding of data transmitted over the physical layer (e.g., intercepted on an air interface), and protect data integrity (e.g., to ensure control messages originate from intended sources). The PDCP 1961 and PDCP 1962 may perform retransmissions of undelivered packets, in-sequence delivery and reordering of packets, duplication of packets, and/or identification and removal of duplicate packets. In a dual connectivity scenario, PDCP 1961 and PDCP 1962 may perform mapping between a split radio bearer and RLC channels.
RLC 1951 and RLC 1952 may perform segmentation, retransmission through Automatic Repeat Request (ARQ). The RLC 1951 and RLC 1952 may perform removal of duplicate data units received from MAC 1941 and MAC 1942, respectively. The RLCs 213 and 223 may provide RLC channels as a service to PDCPs 214 and 224, respectively.
MAC 1941 and MAC 1942 may perform multiplexing and/or demultiplexing of logical channels. MAC 1941 and MAC 1942 may map logical channels to transport channels. In an example, UE 1901 may, in MAC 1941, multiplex data units of one or more logical channels into a transport block. The UE 1901 may transmit the transport block to the gNB 1902 using PHY 1931. The gNB 1902 may receive the transport block using PHY 1932 and demultiplex data units of the transport blocks back into logical channels. MAC 1941 and MAC 1942 may perform error correction through Hybrid Automatic Repeat Request (HARQ), logical channel prioritization, and/or padding.
PHY 1931 and PHY 1932 may perform mapping of transport channels to physical channels. PHY 1931 and PHY 1932 may perform digital and analog signal processing functions (e.g., coding/decoding and modulation/demodulation) for sending and receiving information (e.g., transmission via an air interface). PHY 1931 and PHY 1932 may perform multi-antenna mapping.
One or more of the base stations of the NG-RAN may be split into a central unit (CU) and one or more distributed units (DUs). A CU may be coupled to one or more DUs via an F1 interface. The CU may handle one or more upper layers in the protocol stack and the DU may handle one or more lower layers in the protocol stack. For example, the CU may handle RRC, PDCP, and SDAP, and the DU may handle RLC, MAC, and PHY. The one or more DUs may be in geographically diverse locations relative to the CU and/or each other. Accordingly, the CU/DU split architecture may permit increased coverage and/or better coordination.
The central unit may be referred to as and/or interchangeable with a base station central unit or a central unit of a base station or a CU or a gNB-CU. The distributed unit may be referred to as and/or interchangeable with a base station distributed unit or a distributed unit of a base station or a DU or a gNB-DU.
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In an example, the measurement timing configuration (measurementtimingconfiguration) may be used to convey assistance information for measurement timing (meastiming). The measurement timing configuration may comprise at least one of: a measurement timing (meastiming); camp on first SSB (camponfirstSSB); PSCell only on first SSB (PScellonlyonfirstSSB); and CSI-RS configuration (CSI-RS-config). The measurement timing (meastiming) may comprise a frequency and timing (frequencyandtiming); SSB to measure (ssb-tomeasure); and a physical cell identifier (physcellid). The frequency and timing (frequencyandtiming) may comprise at least one of: a carrier frequency (carrierfreq); SSB subcarrier spacing (ssbSubcarrierSpacing); SSB measurement timing configuration (ssb-measurementtimingconfiguration); SS-RSSI measurement (ss-RSSI-Measurement).
In an example, the CSI-RS configuration may comprise at least one of: CSI-RS subcarrier spacing (csi-RS-subcarrierspacing); CSI-RS cell mobility (csi-RS-cellmobility); and reference SSB frequency (refSSBfreq). The csi-RS-cellmobility may indicate the CSI-RS configuration of the cell for which this message is included. The timing of the CSI-RS resources may be based on the SSB indicated by the refSSBfreq. The csi-RS-subcarrierspacing may indicate the subcarrier spacing of the CSI-RS resources included in csi-RS-cellmobility.
In an example, the meastiming may be a list of SMTC information, SSB RSSI measurement information and associated frequency (e.g., NR frequency) exchanged via X2 interface (e.g., for X2 setup/update or DC configuration Setup/update or Xn setup/update or node (e.g., a base station) configuration update or F1 messages between a base station central unit and a base station distributed unit). physcellid may be physical cell identity of the SSB on the ARFCN indicated by the carrierfreq (carrier frequency). The camponfirstSSB (e.g., indicating be a value true) may indicates that the SSB indicated in the first instance of meastiming in the meastiming list can be used for camping and for a PCell configuration. The meastiming list may comprise one or more meastimings. The ssb-tomeasure may be the set of SS blocks to be measured within the SMTC measurement duration.
In an example, the carrierfreq (carrier frequency) and the SSB subcarrier spacing (ssb SubcarrierSpacing) may indicate the frequency and subcarrier spacing of the SS block of the cell for which this message is included, or of other SS blocks within the same carrier. The SSB measurement timing configuration (ssb-measurementtimingconfiguration) may indicate the SMTC which can be used to search for SSB of the cell for which the message is included. The SS-RSSI measurement (ss-RSSI-beasurement) may provide the configuration which can be used for RSSI measurements of the cell for which the message is included.
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The multi-USIM may be referred to as and/or interchangeable with musim, MUSIM and/or the like.
The multi-USIM device may maintain a separate registration state or an separate connection management (CM)/mobility management (MM) mode/state or an separate RRC state or a separate protocol stack with a PLMN for each USIM at least over 3GPP access and supporting one or more of the enhancements.
The multi-USIM device may comprise multiple-protocol stacks. Each USIM of the multi-USIM may comprise/maintain a separate protocol stack as shown in
A network and a wireless device may support one or more of the following enhancements for multi-USIM device operation: connection release; paging cause indication for voice service; reject paging request; paging restriction. In the registration procedure, when a multi-USIM device has more than one USIM active (or inserted), supports and intends to use one or more multi-USIM specific features, it may indicate to an access and mobility management function (AMF) corresponding multi-USIM feature(s) are supported. Based on the received indication of supported multi-USIM features from the wireless device, the AMF may indicate to the wireless device the support of the multi-USIM features based on the multi-USIM features supported by network and any preference policy by the network, if available. When a UE turns to have only one USIM active from a multi-USIM device that previously indicated to the network for the USIM with supported multi-USIM feature(s), the UE may indicate all the multi-USIM features are not supported to the network for the USIM. The AMF may indicate the support of paging restriction feature together with the support of either connection release feature or reject paging feature. The multi-USIM UE may include the support of individual features for connection release, paging cause indication for voice service, reject paging request and paging restriction. A multi-USIM device may use a separate permanent equipment identifier (PEI) for each USIM when it registers to the network.
A multi-USIM device may request the network to release the wireless device (the multi-USIM device) from an RRC connected state for a USIM due to activity on another USIM, if both wireless device and network indicate this feature is supported to each other.
The wireless device may indicate that it requests to be released from an RRC connected state, by initiating either a service request procedure or a registration procedure (e.g., in case the wireless device needs to perform registration update at the same time with this network), including a release indication. If supported by the wireless device, the wireless device may also provide, only together with the release indication, a paging restriction information, which requests the network to restrict paging. The paging restriction information from the wireless device may be stored in the UE context (contexts of the wireless device) in the AMF. If no paging restriction information is provided in the service request or the registration request, any stored paging restriction information in the UE context may be removed.
When the wireless device initiates a service request procedure or registration procedure without providing a release indication, the network may remove stored paging restriction information.
A wireless device and a network may support paging cause indication for voice service feature. The network that supports paging cause indication for voice service feature may provide a voice service indication for IP multimedia subsystem (IMS) voice service in the paging message (e.g., if the UE indicates the paging cause indication for voice service feature is supported to the network). The network may determine the IMS voice service based on the paging policy indicator. Upon reception of the voice service indication in (NGAP) paging message from AMF, the base station (e.g., NG-RAN) supporting paging cause indication for voice service may include the voice service indication in the (Uu) paging message to the wireless device. The NGAP paging message is a paging message sent via NAGP interface wherein the NGAP interface is between AMF and a base station. The Uu paging message is a paging message sent via Uu interface where the Uu interface is between a wireless device and a base station.
When the UE context indicates paging cause indication for voice service feature is supported, in order to require a base station (e.g., NG RAN) to deliver the voice service indication in RAN paging for UE in an RRC inactive state, the AMF may provide an indication indicating the paging cause indication for voice service feature is supported to the base station. Upon reception the indication, the base station supporting the paging cause indication for voice service indication feature may store it into the UE context. For a UE in an RRC inactive state, the base station may provide the voice service indication in the RAN paging message (e.g., when there is paging cause indication for voice service indication in the UE context and detects the downlink data which triggers the RAN paging message is related to voice service based on the paging policy indicator, in the header of the received downlink data).
A wireless device that supports the paging cause indication for voice service feature may be capable of differentiation between paging from a network that does not support the paging cause indication for voice service feature and paging without the voice service indication.
A wireless device (multi-USIM device) may setup connection to respond to a page with a reject paging indication to the network indicating that the UE does not accept the paging and requests to return to CM-idle state after sending this response, (e.g., if both wireless device and network indicate this feature is supported to each other).
Upon being paged by the network, the wireless device in CM-idle state may attempt to send a service request message to this network including the reject paging indication, unless it is unable to do so, e.g., due to UE implementation constraints. In addition to the reject paging indication, the wireless device may include paging restriction information in the service request message, if supported by wireless device.
A wireless device and a network may support paging restriction. The wireless device, if the AMF indicates that the network supports paging restriction feature, may indicate paging restriction information in the service request or registration request message as specified. The paging restriction information may indicate the following: a) all paging is restricted; or b) all paging is restricted, except paging for voice service (IMS voice); or c) all paging is restricted, except for certain PDU Session(s); or d) all paging is restricted, except paging for voice service (IMS voice) and certain PDU session(s). The wireless device may expect not to be paged for any purpose in case a). The wireless device may expect to be paged only for voice service in case b). The wireless device may expect to be paged only for certain PDU Session(s) in case c). The UE may expect to be paged for voice service and certain PDU session(s) in case d). In the case of roaming, the paging restrictions for voice service implied by bullet b) and d) may depend on the existence of an agreement with the HPLMN to support voice service via IMS. Hence the support of paging restrictions in bullets b) and d) may take the IMS voice service agreement into consideration.
A wireless device that support or is capable MUSIM (multi-USIM) (e.g., multi-USIM device) and in 5 GMM-idle mode requests the network to remove the paging restriction. The wireless may request the release of the NAS signaling connection or rejects the paging request from the network.
A wireless device may invoke/initiate the service request procedure when the wireless device, in 5 GMM-IDLE mode over 3GPP access, receives a paging request from the network
A wireless device may invoke/initiate the service request procedure when the wireless device, in 5 GMM-connected mode over 3GPP access, receives a notification from the network with access type indicating non-3GPP access;
A wireless device may invoke/initiate the service request procedure when the wireless device, in 5 GMM-idle mode over 3GPP access, has uplink signaling pending;
A wireless device may invoke/initiate the service request procedure when the wireless device, in 5 GMM-idle mode over 3GPP access, has uplink user data pending (except in case j);
A wireless device may invoke/initiate the service request procedure when the wireless device that is MUSIM capable (multi-USIM device) and in 5 GMM-idle mode is requesting the network to remove the paging restriction.
A wireless device may invoke/initiate the service request procedure when the wireless device (multi-USIM device), is in 5 GMM-CONNECTED mode or is in 5 GMM-CONNECTED mode with RRC inactive indication, rejects the RAN paging; and requests the network to release the NAS signaling connection and optionally includes paging restrictions.
A wireless device may invoke/initiate the service request procedure when the wireless device (multi-USIM device), in 5 GMM-IDLE mode when responding to paging rejects the paging request from the network, requests the network to release the NAS signaling connection and optionally includes paging restrictions.
A base station (e.g., NG-RAN) may support one or more of the following enhancements for multi-USIM device operation: paging collision avoidance; UE notification on network switching; busy indication.
A multi-USIM device, in an RRC connected state in network A and in an RRC idle state or an RRC idle state in network B, may receive a paging message from network B. If the multi-USIM device considers the current service in network A as having higher importance/priority than the service in Network B, it can reject the incoming paging by sending a signal (e.g., NAS signal) including a busy Indication.
The purpose of paging collision avoidance is to address the overlap of paging occasions on both USIMs when a multi-USIM device (e.g., dual USIM device) is in an RRC idle state or an RRC inactive state in both the networks (e.g., network A/a first network and network B/a second network) associated with respective SIMs. Both networks may be NR network or E-UTRA network to address the scenario where network A is NR and network Bis E-UTRA or NR.
A multi-SIM device may determine potential paging collision on two networks and may trigger actions to prevent potential paging collision.
For multi-USIM purpose, a multi-USIM device in an RRC connected state in network A may have to switch from network A to network B. Network A may be NR and Network B may either be E-UTRA or NR. Before switching from network, A, a multi-USIM device may notify network A to either leave an RRC connected state, or be kept in an RRC connected state in network A while temporarily switching to network B.
A multi-USIM device may signal the network a preference to leave an RRC connected state by using an RRC signalling/message or an NAS signalling/message. After sending a preference to leave an RRC connected state by using RRC signalling/message, if the multi-USIM device does not receive an RRC release message from the network A within a certain time period (if configured by the Network), the multi-USIM device can enter an RRC idle state in the network A.
A multi-USIM device may signal the network a preference to be kept in an RRC connected state in Network A while temporarily switching to network B, this may be indicated by a preference of a MUSIM gap. This preference may include a gap information for setup or release of gaps for MUSIM.
For example, the network may configure at most 3 gap patterns for multi-USIM purpose: two periodic gaps and a single aperiodic gap. The periodic gap may be configured for a periodic switching or system information (SI) receiving at the second network. The periodic switching may comprise SSB detection/paging reception, serving cell measurement, neighboring cell measurement including intra-frequency, inter-frequency, and inter-RAT measurement. The aperiodic (one-shot) switching may configured for both transmission and reception, of a wireless device, at network B. For the aperiodic switching, a wireless device may not enter an RRC connected state in the second network. The wireless device may not receive an RRC resume message or an RRC setup message from the second network. For example, the wireless device may transmit (on-demand) SI request message, to a base station of the second network. The wireless device may receive the requested SI after transmitting the SI request message. For example, the base station may transmit/broadcast the requested SI. The wireless device may transmit the on-demand SI request to the base station via Msg 1 or Msg 3. The aperiodic gap may indicate a time duration from transmitting the SI request message to receiving the requested SI.
A wireless device may acquire SIB, other than SIB1, in RRC idle or RRC inactive state. The wireless device may not have valid version of SI of the other SIB in stored SIBs. A base station may provide SI broadcast status information in SIB1 indicating whether the other SIB is broadcast. The wireless device in RRC idle or RRC inactive state may perform a SI request procedure (e.g., either a 2-step or 4-step SI request procedure) to acquire the SI when the SI broadcast status in the SIB1 is set to ‘not broadcasting’. The wireless device in RRC in RRC idle or RRC inactive state may acquire the SI message comprising the other SIB. The wireless device may select between a 2-step and 4-step SI request procedure for acquiring an SIB other than SIB1. SIB1 may include an SI request configuration. The SI request configuration may comprise a PRACH preamble and PRACH resource corresponding to an SI message. The UE in RRC idle state or RRC inactive state may perform a 2-step SI request procedure when SIB1 includes an SI request configuration corresponding to the SIB the UE desires to acquire. Otherwise, the wireless device in RRC idle state or RRC inactive state may perform a 4-step SI request procedure to acquire the SIB the wireless device desires to acquire.
For the 2 step SI request procedure, the wireless device may determine a PRACH preamble and PRACH resource corresponding to a desired SIB in SI request configuration received via SIB1. The wireless device may initiate a random access procedure using the PRACH preamble and PRACH resource. Upon receiving the PRACH preamble, the base station may broadcast the desired SIB on the DL-SCH and send an acknowledgement (Ack) for the SI request to the wireless device. Upon receiving the acknowledgement, the wireless device in RRC idle state or RRC inactive state may acquire the broadcasted SIB on the DL-SCH. For the 4 step SI request procedure, the wireless device may initiate transmission of an RRC system info request message. The RRC system info request message may comprise a list of one or more SIBs the wireless device desires to acquire. The wireless device may send the RRC system info request message after a random access procedure is successfully completed. Upon receiving the RRC system info request message, the base station may send the one or more SIBs and an acknowledgement (Ack) for the SI request to the wireless device. Upon receiving the acknowledgement, the wireless device in RRC idle state or RRC inactive state may acquire the requested SIB.
In an example, a wireless device (e.g., a multi-USIM device) may signal the network through an RRC message: if the wireless device prefers to leave the network for multi-USIM purpose; or if the wireless device indicates a preference on a MUSIM gap or a request to setup or release a MUSIM gap. For example, upon determining that it needs to leave RRC_CONNECTED state, or upon determining it needs the MUSIM gaps, or upon change of the gap information without leaving RRC_CONNECTED state, a wireless device may transmit the RRC message. For example, a wireless device having a preference for MUSIM gap(s) may include MUSIM gap request list in the RRC message. a wireless device no longer having a preference for MUSIM gap(s) may not include MUSIM gap request list in the RRC message. If a wireless device needs to leave an RRC connected state, the wireless device may include an indication of a preferred RRC state for MUSIM in the RRC message. The wireless device transmits the RRC message to a base station. The preferred RRC state may indicate an RRC idle state or an RRC inactive state. The MUSIM gap request list may comprise one or more MUSIM gap information. The MUSIM gap information may indicate a MUSIM gap information the wireless device prefers. The MUSIM gap information may comprise a gap starting position, a gap length, and a gap repetition period. The gap starting position may be indicated by MUSIM gap offset or start SFN and subframe. The MUSIM gap information may comprise at least one of: a MUSIM gap offset; a MUSIM gap length; and a MUSIM gap repetition period. For the aperiodic gap, the MUSIM gap information may comprise a MUSIM gap offset and a MUSIM gap length. For the periodic gap, the MUSIM gap information may comprise a MUSIM gap offset; a MUSIM gap length; and a MUSIM gap repetition period.
A base station may transmit to a wireless device a MUSIM gap configuration via an RRC reconfiguration message. The MUSIM gap configuration may indicate a gap starting position, a gap length, and a gap repetition period. The gap starting position may be indicated by MUSIM gap offset or start SFN and subframe.
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The switching gap may be referred to as and/or interchangeable with a multi-USIM gap, a musim gap and/or the like.
A transmitter (a radio transmitter) of the wireless device may be an electronic device which produces radio waves with an antenna. The transmitter may generate a radio frequency alternating current, which is applied to the antenna. For example, the antenna may radiate radio waves. The term transmitter may be limited to equipment that generates radio waves for communication purposes; or radiolocation, such as radar and navigational transmitters. A transmitter may be a separate piece of electronic equipment, or an electrical circuit within another electronic device. A transmitter and a receiver combined in one unit may be called a transceiver. The term transmitter is often abbreviated “XMTR” or “TX” in technical documents. The purpose of most transmitters may be radio communication of information over a distance. The information may be provided to the transmitter in the form of an electronic signal, such as an audio (sound) signal from a microphone, a video (TV) signal from a video camera, or in wireless (networking) devices, a digital signal from a computer. The transmitter may combine the information signal to be carried with the radio frequency signal which generates the radio waves, which is called the carrier signal. This process may be called modulation. The radio signal from the transmitter may be applied to the antenna, which radiates the energy as radio waves. The antenna may be enclosed inside the case or attached to the outside of the transmitter, as in portable devices such as cell phones. The transmitter may be (group of) antenna or (group of) antenna panel or (group of) MIMO layer or (group of) emitter. Each antenna panel may have one or more antenna elements. For example, a first one or more antennas (or a first one or more antenna panels, or a first one or more MIMO layers) may be a first transmitter. A second one or more antennas (or a second one or more antenna panels, or a first one or more MIMO layers) may be a second transmitter. For example, a base station and/or a wireless device may have multiple antennas. a number of antenna elements may be assembled into multiple antennas. Multi-panel MIMO (layer) may be used for communication between the wireless and the base station.
In an example, a wireless device may receive, from a base station, a measurement configuration. The measurement configuration may indicate one or more frequencies and/or one or more cells on which the wireless device performs measurements. Based on the measurement configuration, the wireless device may perform the measurements on a frequency and/or a cell which is indicated by the measurement configuration.
A wireless device may perform measurements using the measurement configuration during a measurement gap, e.g., indicated by the measurement configuration. In the present disclosure, the measurement gap may be referred to as and/or interchangeable with a gap, a gap (period and/or interval), a measurement gap (period and/or interval), and/or the like.
The measurement gap may be a time duration in which a wireless device may measure wireless channel condition associated with a cell, of a particular base station (e.g., network), and/or configured in a particular frequency using a particular RAT. For example, the particular base station (e.g., network) may be the same base station (e.g., the same network) that the wireless device maintains a connection (e.g., RRC connection). For example, the particular base station (e.g., network) may be different from a base station (e.g., a network) that the wireless device maintains a connection (e.g., RRC connection). For example, the particular RAT may be Wi-Fi, LTE, NR, and/or the like. For example, the particular RAT may be the same RAT that the wireless device uses to maintain a connection (e.g., RRC connection) with a first base station e.g., a network). For example, the particular RAT may be different from an RAT that the wireless device uses to maintain a connection (e.g., RRC connection) with a first base station e.g., a network).
For example, a wireless device may maintain a connection (e.g., RRC connection) with a current base station (e.g., network) during the measurement gap. The wireless device may not communicate with the current base station during the measurement gap. For example, the wireless device may not, during the measurement gap, transmit to and/or receive from the current base station data (e.g., message, packet, SDU, PDU, and/or transport block) and/or a reference signal (e.g., SRS, and/or CSI-RS). The wireless device may not, during the measurement gap, monitor a downlink control channel configured by the current base station. The current base station may not communicate with the wireless device during the measurement gap. For example, the current base station may not, during the measurement gap, transmit to and/or receive from the wireless device, data (e.g., message, packet, SDU, PDU, and/or transport block) and/or a reference signal (e.g., SRS, and/or CSI-RS). The current base station may not, during the measurement gap, monitor an uplink control channel configured for the wireless device.
For example, a wireless device may communicate with a second device (e.g., a second wireless device, a second base station, a second network, and/or the like) during the measurement gap while maintaining a connection (e.g., RRC connection) with a current base station (e.g., network). For example, the communicating with the second device may comprise monitoring a downlink channel (e.g., paging channel, PDCCH, PDSCH, SSB, CSI-RS, and/or the like) of the second device during the measurement gap. For example, the communicating with the second device may comprise receiving a signal and/or data via a downlink channel (e.g., PDCCH, PDSCH, SSB, CSI-RS, and/or the like) from the second device during the measurement gap. For example, the communicating with the second device may comprise receiving a signal (e.g., reference signal such as SSB, CSI-RS) and/or data (e.g., message, packet, SDU, PDU, and/or transport block) via a downlink channel (e.g., PDCCH, PDSCH, SSB, CSI-RS, and/or the like) from the second device during the measurement gap. For example, the communicating with the second device may comprise transmitting a signal (e.g., reference signal such as SRS, preamble, and/or the like) and/or data (e.g., message, packet, SDU, PDU, Msg3, MsgB, and/or transport block) via an uplink channel (e.g., PRACH, PUSCH, PUCCH, and/or SRS, and/or the like) to the second device during the measurement gap.
The wireless device may not communicate with the current base station during the measurement gap. For example, the wireless device may not, during the measurement gap, transmit to and/or receive from the current base station data (e.g., packet, SDU, PDU, and/or transport block) and/or a reference signal (e.g., SRS, and/or CSI-RS). The wireless device may not, during the measurement gap, monitor a downlink control channel configured by the current base station. The current base station may not communicate with the wireless device during the measurement gap. For example, the current base station may not, during the measurement gap, transmit to and/or receive from the wireless device, data (e.g., packet, SDU, PDU, and/or transport block) and/or a reference signal (e.g., SRS, and/or CSI-RS). The current base station may not, during the measurement gap, monitor an uplink control channel configured for the wireless device.
In an example, a wireless device may receive, from a base station, a measurement configuration. The measurement configuration may comprise measurement gap configuration. The measurement gap configuration may comprise one or more configuration parameters. The one or more configuration parameters of the measurement gap may indicate periods that the wireless device may use to perform measurements. The one or more configuration parameters may indicate one or more measurement gaps. Each measurement gap of the one or more measurement gaps may be associated with one or more frequency range that the wireless device performs one or more measurements using the one or more configuration parameters. For example, each measurement gap of the one or more measurement gaps may be per a frequency or a frequency range (e.g., FR1. FR2, and/or FR3) and/or per a wireless device/UE. For example, the measurement gap per a frequency range (e.g., FR1, FR2, and/or FR3) may be applied to measurement(s) that the wireless device performs in the respective frequency range. The measurement gap per the wireless device/UE may be applied to measurement(s) that the wireless device performs one or more (e.g., all) frequencies (e.g., FR1, FR2, and/or FR3). The each measurement gap may comprise at least one of: measurement gap repetition period (mgrp) value, measurement gap length (mgl) value, gap offset value and a serving cell identifier. The mgrp value may indicate measurement gap repetition period in (ms) of the measurement gap. The mgl value may indicate the measurement gap length in ms of the measurement gap. The gap offset value may indicate the gap offset of the gap pattern with mgrp indicated in the field mgrp.
During the measurement gap period/time, the wireless device may not transmit data to the base station. For example, the data may comprise at least one of: HARQ feedback, SR, and CSI, SRS report and UL-SCH. During the measurement gap, the wireless device may not monitor downlink channel (e.g., PDCCH) of a serving cell of the base station. The wireless device may not receive (downlink data) on DL-SCH.
In an example, during the measurement gap period/time, the base station may not transmit downlink data to the base station. For example, the downlink data may comprise at least one of: DCI, MAC CE, and a data on DL-SCH. During the measurement gap, (a serving cell of) the base station may not monitor uplink channel (e.g., PUCCH/PUSCH) of the wireless device. The base station may not receive (uplink data) on UL-SCH.
In the present disclosure, a wireless device may be referred to as and/or interchangeable with a multi-USIM device, a musim device and/or the like.
In the present disclosure, a first/second device may be a first/second base station or a first/second wireless device.
In the present disclosure, a gap may be one or more time durations/periods in which a wireless device is allowed to communicate with a second device without releasing a connection of a first device.
In an example, the gap may is characterized by a gap starting position (e.g., offset value or start SFN and subframe explicitly), gap length and gap repetition period. the gap may be configured or released by RRC signalling (e.g., RRC reconfiguration message).
In an example, the sidelink gap may indicate a time duration/period in which a wireless device is allowed to communicate, via a sidelink, with a second wireless device without releasing a connection of a first device. For example, the first device may be a first wireless device or a first base station. The first base station may comprise a serving cell of the wireless device. The sidelink may indicate a link between wireless devices.
In the disclosure, an idle state may be an RRC idle state or an CM idle state. A connected state may be an RRC connected state or an CM connected state.
In the present disclosure, a MUSIM gap may be referred to as and/or interchangeable with a MUSIM gap and/or the like.
In the present disclosure, a procedure on a second network may be referred to as and/or interchangeable with a MUSIM procedure and/or the like.
In the present disclosure, a parameter for a (first) procedure may be referred to as and/or interchangeable with a parameter for a (first) gap of the (first) procedure and/or the like.
In the present disclosure, a (first/second/MUSIM/measurement) gap may be referred to as and/or interchangeable with a configuration of the (first/second/MUSIM/measurement) gap and/or the like. Transmitting a (first/second/MUSIM/measurement) gap may be referred to as and/or interchangeable with transmitting a configuration of the (first/second/MUSIM/measurement) gap and/or the like. Receiving a (first/second/MUSIM/measurement) gap may be referred to as and/or interchangeable with receiving a configuration of the (first/second/MUSIM/measurement) gap and/or the like.
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A wireless device may have a limited radio capability not supporting to perform multiple tasks/procedures at a time or on specific frequency (band) combinations (e.g., a first task/procedure on a first frequency and a second task/procedure on a second frequency). For example, the wireless device may have a limited number of a transmitter and/or a receiver (e.g., one transmitter and/or one receiver). The transmitter/receiver of the wireless device may not support multiple tasks/procedures at a time or the specific frequency (band) combinations. The wireless device may fail to perform one or more of multiple tasks/procedures when the multiple procedures are triggered at the same time and/or on the specific frequency combinations. For example, a wireless device may need (or be configured) to perform a first procedure on a first time and/or a first frequency and may need (or be configured) to perform a second procedure on a second time and/or a second frequency. For example, the wireless device may fail to perform one or both procedures based on having the limited radio capability not supporting multiple tasks/procedures at the first time being overlapped with the second time; or on the first frequency and the second frequency simultaneously.
A base station of a network may configure to the wireless device (e.g., having the limited radio capability) a gap, for a procedure, in which the wireless device is allowed to perform the procedure while the wireless device is not required to perform other procedures with the network. For example, during the gap, the wireless device may not require monitoring a downlink channel or receiving downlink data/signal from cell(s) of base station(s) of the network. During the gap, the network may not transmit downlink data/signal to the wireless device.
In existing technologies, a base station may be configured to a wireless device (e.g., having the limited radio capability) a first gap for a first procedure. The wireless device may perform the first procedure during the first gap and not require performing other procedures. From the base station, the wireless device may be configured to perform a second procedure which needs (or is configured) to be performed during one of the first gap. The wireless device may have the limited radio capability which does not support to perform the second procedure together with the first procedure at a time and/or on a specific frequency combination at a time. The wireless device may fail to perform one or both of the first procedure and the second procedure. It may cause waste of resource (e.g., time and/or radio resource) and waste of power of the wireless device.
For example, the first gap and a second gap may be one of measurement gap and a MUSIM gap. For example, the first procedure may be a procedure associated with the measurement gap. For example, the procedure associated with the measurement gap may comprise at least one of: uplink transmission(s), downlink reception(s), and/or downlink signal measurement(s) that the wireless device performed during the measurement gap and/or based on the measurement gap. For example, the second procedure may be a procedure associated with the MUSIM gap. For example, the procedure associated with the MUSIM gap may comprise at least one of: uplink transmission(s), downlink reception(s), and/or downlink signal measurement(s) that the wireless device performed during the MUSIM gap and/or based on the MUSIM gap. In an example, a base station of a first network, a wireless device may receive a MUSIM gap used to perform a procedure on a second network without leaving an RRC connected state in the first network. The wireless device may be configured to perform measurement on a measurement object (e.g., reference signal of a reference cell such as SSB and/or CSI RS of the reference cell) during a time and/or in a frequency (e.g., absolute radio-frequency channel number and/or frequency offset relative Point A of the cell). The wireless device may receive a measurement configuration indicating the measurement object (e.g., reference signal of a reference cell such as SSB and/or CSI RS of the reference cell), the time, and/or the frequency (e.g., absolute radio-frequency channel number and/or frequency offset relative to a reference frequency, Point A, of the cell). The time may be overlapped with one of the MUSIM gap. The wireless device may not perform the measurement and the procedure on the second network during the one of the MUSIM gap (e.g., due to the limited radio capability of the wireless device). For example, a wireless device may perform the measurement based on receiving, from a base station, a measurement configuration for measurement on a measurement object during a time and/or in a frequency. The wireless device may be allowed to perform a procedure on a second network based on receiving a MUSIM gap without leaving an RRC connected state in a first network. The time may be overlapped with one of the MUSIM gap. The wireless device may not perform (e.g., may not be capable of performing) concurrently the measurement and the procedure on the second network during the one of the MUSIM gap (e.g., due to the limited capability of the wireless device).
In existing technologies, a base station distributed unit of a base station may wait for receiving, from a base station central unit of the base station, information for a first procedure (e.g., measurement) of a wireless device to transmit a first gap (e.g., a measurement gap) for the first procedure to the base station central unit. For example, from a base station central unit, a base station distributed unit may receive information for a second procedure (e.g., a procedure, for MUSIM, on a second network) for a wireless device being configured to perform a first procedure. The base station distributed unit may determine that the wireless device needs a first gap for the first procedure and wait for receiving information for the first procedure from the base station central unit. It may cause delay to transmit the first gap to the wireless device. The wireless device may not perform the first procedure until receiving the first gap from the base station. Example embodiments of the present disclosure are directed to an enhanced procedure for a base station and a wireless device to avoid multiple procedures performed during a gap. For example, example embodiments enable the interplay between a plurality of procedures/gaps (e.g., measurement gap and MUSIM gap) that are determined in conjunction with a wireless device capability. For example, a base station distributed unit determines a first gap (e.g., measurement gap) for a first procedure (e.g., measurement) based on information (e.g., MUSIM gap and/or a parameter for MUSIM gap received from a base station central unit) for a second procedure (e.g., a procedure on a second network). For example, a base station distributed unit determines a second gap (e.g., MUSIM gap) for a second procedure (e.g., a procedure on a second network) based on information (e.g., measurement gap, measurement configuration, and/or measurement timing configuration received from a base station central unit) for a second procedure (e.g., measurement). Example embodiments enable the base station and the wireless device to avoid waste of radio resources and power consumption occurred due to a failure of one or more procedures from the multiple procedures performed during a gap.
Example embodiments may enable a base station distributed unit to determine, based on receiving information for a first procedure of a wireless device, whether the wireless device needs a second gap for a second procedure. For example, a base station distributed unit may determine, based on receiving a parameter for a MUSIM gap of a procedure of a wireless device on a second network, whether the wireless device needs a measurement gap for measurement (procedure). For example, a base station distributed unit of a first network may determine, based on receiving a measurement configuration or measurement timing configuration for measurement, a MUSIM gap for a procedure on a second network.
Example embodiments may enable a base station distributed unit to transmit a second gap for a second procedure to a base station central unit based on receiving information for a first procedure (e.g., and determining that the wireless device needs the second gap). For example, a base station distributed unit may transmit a measurement gap for measurement (procedure) to a base station central unit based on receiving a parameter for a MUSIM gap of a procedure on a second network (e.g., and determining that the wireless device needs the measurement gap). The base station central unit may transmit the measurement gap to the wireless device. For example, a base station distributed unit of a first network may transmit a MUSIM gap for a procedure on a second network to a base station central unit based on receiving a measurement configuration or measurement timing configuration for measurement (e.g., and determining that the wireless device needs the MUSIM gap). The base station central unit may transmit the MUSIM gap to the wireless device.
Example embodiments may enable a base station central unit to transmit a request of a second gap for a second procedure of a wireless device to a base station distributed unit when transmitting information for a first procedure of the wireless device to a base station distributed unit. For example, a base station central unit transmitting information for a first procedure of a wireless device may determine that the wireless device needs a second gap for a second procedure. The base station central unit may transmit a request for the second gap to a bases station distributed unit (e.g., based on determining that the wireless device needs the second gap). Based on receiving the request, the base station distributed unit may transmit the second gap to the base station central unit. The base station central unit may transmit the second gap to the wireless device.
Example embodiments may enable a wireless device to transmit a request of a second gap for a second procedure of a wireless device to a base station when transmitting information for a first procedure to a base station. For example, a wireless device transmitting information for a first procedure may determine that the wireless device needs a second gap for a second procedure. The wireless device may transmit a request for the second gap to a bases station and the information via an RRC message (e.g., based on determining that the wireless device needs the second gap). Based on receiving the request, the base station may transmit the second gap to the wireless device.
In an example, a base station distributed unit may receive, from a base station central unit, a message indicating information for a first procedure of a wireless device. The base station distributed unit may transmit, based on the information and to a base station central unit, a response message indicating a configuration of a second gap for a second procedure of the wireless device.
In an example, a base station distributed unit may receive, from a base station central unit, a message indicating information for a first procedure of a wireless device. In response to receiving the information, the base station distributed unit may transmit to a base station central unit a response message indicating a configuration of a second gap for a second procedure of the wireless device.
In an example, based on receiving the information for the first procedure, the base station distributed unit may determine whether a first gap for the first procedure needs for the wireless device; whether the wireless device is able to perform the second procedure and/or the first procedure (e.g., the second procedure together with the first procedure). For example, the second procedure may be a procedure which was configured to the wireless device; or is supposed to be configured to the wireless device. For example, based on receiving a configuration for the second procedure, a base station distributed unit may determine that the second procedure is supposed to be configured to the wireless device. For example, based on receiving a measurement configuration for a measurement (procedure), a base station distributed unit may determine that the measurement (procedure) is supposed to be configured to the wireless device.
For example, the base station distributed unit may determine that the wireless device is not able to perform the second procedure and/or the first procedure (e.g., the second procedure together with the first procedure). Based on the determining, the base station distributed unit may determine that the wireless device needs a gap for the first procedure and/or the second procedure. Based on the determining, the base station distributed unit may transmit the gap (or a configuration of the gap) to the base station central unit. The gap may be the first gap for the first procedure; or the second gap for the second procedure; or a third gap for the first procedure and the second procedure. The gap (or the configuration of the gap) may indicate a procedure which the gap is applied. The procedure may indicate one or more procedure. The procedure may be the first procedure; or the second procedure; or both of the first procedure and the second procedure. Based on receiving the gap (or the configuration of the gap), the base station central unit may transmit the gap (or the configuration of the gap) to the wireless device. The wireless device may perform the first procedure and/or the second procedure based on the gap (or the configuration of the gap).
For example, the base station distributed unit may determine, that the wireless device is not able to perform the second procedure and/or the first procedure (e.g., the second procedure together with the first procedure), based on a first gap for the first procedure being overlapped with a gap, for the second procedure, configured to the wireless device; or a time, which the first procedure is configured to be performed, being overlapped with the gap, for the second procedure, configured to the wireless device; or the time, which the first procedure is configured to be performed, being overlapped with a second time, which the second procedure is configured to be performed.
For example, the base station distributed unit may determine, whether the wireless device is not able to perform the second procedure and/or the first procedure (e.g., the second procedure together with the first procedure), based on a capability of the wireless device. The base station distributed unit may determine that the wireless device needs a gap for the first procedure and/or the second procedure based on the capability of the wireless device.
For example, based on receiving the information for the first procedure, the base station distributed unit may determine that the wireless device is not able to perform the second procedure and/or the first procedure (e.g., the second procedure together with the first procedure). Based on the determining, the base station distributed unit may determine that the second gap for the second procedure. Based on the determining, the base station distributed unit may transmit the configuration of the second gap to the base station central unit.
For example, based on receiving the information for the first procedure, the base station distributed unit may determine that the wireless device is not able to perform the second procedure and/or the first procedure (e.g., the second procedure together with the first procedure). The determining that the wireless device is not able to perform the second procedure and/or the first procedure (e.g., the second procedure together with the first procedure) may be further based on determining that the first gap for the first procedure needs for the wireless device. Based on the determining that the wireless device is not able to perform the second procedure and/or the first procedure (e.g., the second procedure together with the first procedure), the base station distributed unit may determine that the second gap for the second procedure. Based on the determining, the base station distributed unit may transmit the configuration of the second gap to the base station central unit. For example, based on the determining, the base station distributed unit may transmit the configuration of the second gap and a configuration of the first gap to the base station central unit.
In an example, the second gap may indicate that the second gap is able to be used for a procedure. the second gap may indicate that the wireless device is able to use the second gap for the procedure. For example, the procedure may indicate/comprise at least one of: the first procedure; and the other procedure (e.g., other than the first procedure).
In an example, based on receiving the information for the first procedure, the base station distributed unit may transmit to the base station central unit a configuration of a first gap for the first procedure. The base station distributed unit may transmit to the base station central unit the response message comprising a configuration of a first gap for the first procedure. The response message may comprise the configuration of the second gap and the configuration of the first gap.
In an example, the message may be a message for management of a context of the wireless device. The message may be a context setup request message or a context modification request message.
In an example, the response message may be a message for management of a context of the wireless device. the response message may be a context setup response message or a context modification response message. The response message is a response to the message.
In an example, a base station central unit may transmit, to a base station distributed unit, a message indicating information for a first procedure of a wireless device. The base station central unit may receive, from the base station distributed unit, a response message indicating a configuration of a second gap for a second procedure of the wireless device.
In an example, a base station central unit may transmit, to a base station distributed unit, a message indicating information for a first procedure of a wireless device. In response to transmitting the information, the base station central unit may receive, from the base station distributed unit, a response message indicating a configuration of a second gap for a second procedure of the wireless device.
In an example, the configuration of the second gap may comprise at least one of: a gap offset; a gap length; and a gap repetition period. The gap offset may indicate a starting position of the second gap. The gap length may indicate a time duration of each of the second gap. The gap repetition period may indicate a period which the second gap repeats. The configuration may further comprise at least one of: a gap timing advance and a cell identifier for reference of the second gap. The gap timing advance may indicate a timing advance for the second gap. The timing advance may be used for calculating the starting position of the second gap. The cell identifier may indicate a cell identifier whose SFN and subframe is used for the second gap calculation for this gap pattern.
In an example, the information for a first procedure may comprise at least one of: a configuration for the first procedure; assistance information for the first procedure; and a gap of the first procedure.
In an example, the assistance information for the first procedure may be assistance information for a first gap of the first procedure. The assistance information for the first gap may indicate preference, of the wireless device, for the first gap. The assistance information for the first gap may comprise at least one of: a gap offset which the wireless device preferred; a gap length which the wireless device preferred; and a gap repetition period which the wireless device preferred.
In an example, the gap for the first procedure may be a gap determined by the bases station central unit. The gap for the first procedure may comprise at least one of: a gap offset which the base station central unit determined; a gap length which the base station central unit determined; and a gap repetition period which the base station central unit determined. The base station central unit may determine the gap based on the assistance information.
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In an example, the assistance information for the MUSIM gap may indicating preference, of the wireless device, for the MUSIM gap. the assistance information for the MUSIM gap may comprise at least one of: a gap offset which the wireless device preferred; a gap length which the wireless device preferred; and a gap repetition period which the wireless device preferred. The first MUSIM gap determined by the bases station central unit may comprise at least one of: a gap offset which the base station central unit determined; a gap length which the base station central unit determined; and a gap repetition period which the base station central unit determined. The base station central unit may determine the first MUSIM gap based on the assistance information.
In an example, after transmitting the information, the base station central unit may receive the response message comprising a configuration of a first gap for the first procedure. For example, the response message may comprise the configuration of the second gap and the configuration of the first gap.
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In an example, a base station central unit may transmit to a base station distributed unit a request of a second gap for a second procedure of a wireless device.
In an example, the base station central unit may transmit the request to the base station distributed unit based on information for a first procedure. For example, the base station central unit may transmit to the base station distributed unit the request based on receiving the information for the first procedure from the wireless device. The base station central unit may transmit to the base station distributed unit the request based on receiving the assistance information for the first procedure from the wireless device.
In an example, the base station central unit may transmit the request to the base station distributed unit based on information for a first procedure. For example, the base station central unit may transmit to the base station distributed unit the request based on determining to transmit to the base station distributed unit information for a first procedure. The information for the first procedure may comprise at least one of: assistance information, for the first procedure, (e.g., received from the wireless device); a gap, for the first procedure, determined (e.g., based on the assistance information) by the base station central unit.
In an example, the base station central unit may determine whether a first gap for the first procedure needs for the wireless device; whether the wireless device is able to perform the first procedure together with second procedure. For example, the second procedure may be a procedure which was configured to the wireless device; or is supposed to be configured to the wireless device. For example, based on the information for the first procedure, the base station central unit may determine whether a first gap for the first procedure needs for the wireless device; whether the wireless device is able to perform the first procedure together with second procedure. The information for the first procedure may comprise at least one of: assistance information, for the first procedure, (e.g., received from the wireless device); a gap, for the first procedure, determined (e.g., based on the assistance information) by the base station central unit. For example, based on receiving a configuration for the second procedure, a base station distributed unit may determine that the second procedure is supposed to be configured to the wireless device. For example, based on receiving a measurement configuration for a measurement (procedure), a base station distributed unit may determine that the measurement (procedure) is supposed to be configured to the wireless device.
In an example, the base station central unit may determine that the wireless device is not able to perform the first procedure together with the second procedure. Based on the determining, the base station central unit may determine that the wireless device needs a gap for the first procedure and/or the second procedure. Based on the determining, the base station central unit may transmit (e.g., via a message) a request of the gap to the base station central unit. The request of the gap may be a first request of the first gap for the first procedure; or a second request of the second gap for the second procedure; or a third request of a third gap for the first procedure and the second procedure. The request of the gap may indicate a procedure which the gap is applied. The procedure may indicate one or more procedure. The procedure may be the first procedure; or the second procedure; or both of the first procedure and the second procedure. Based on receiving the request of the gap, the base station distributed unit may transmit the gap (or the configuration of the gap) (e.g., via a response message) to the base station central unit. The gap (or the configuration of the gap) may indicate a procedure which the gap is applied. Based on receiving the gap (or the configuration of the gap), the base station central unit may transmit the gap (or the configuration of the gap) to the wireless device. The wireless device may perform the first procedure and/or the second procedure based on the gap (or the configuration of the gap).
In an example, the base station central unit may determine, that the wireless device is not able to perform the first procedure together with the second procedure, based on a first gap for the first procedure being overlapped with a gap, for the second procedure, configured to the wireless device; or a time, which the first procedure is configured to be performed, being overlapped with the gap, for the second procedure, configured to the wireless device; or the time, which the first procedure is configured to be performed, being overlapped with a second time, which the second procedure is configured to be performed.
In an example, the base station central unit may determine whether the wireless device is not able to perform the first procedure together with the second procedure based on a capability of the wireless device. The base station central unit may determine that the wireless device needs a gap for the first procedure and/or the second procedure based on the capability of the wireless device.
In an example, the base station central unit may determine that the wireless device is not able to perform the second procedure together with the first procedure. Based on the determining, the base station central unit may determine to transmit the request of the second gap for the second procedure. Based on the determining, the base station central unit may transmit the request of the second gap to the base station central unit. For example, based on the information for the first procedure, the base station central unit may determine that the wireless device is not able to perform the second procedure together with the first procedure.
In an example, the base station central unit may determine that the wireless device is not able to perform the second procedure together with the first procedure. For example, based on the information for the first procedure, the base station central unit may determine that the wireless device is not able to perform the second procedure together with the first procedure. The determining that the wireless device is not able to perform the second procedure together with the first procedure may be further based on determining that the first gap for the first procedure needs for the wireless device. Based on the determining that the wireless device is not able to perform the second procedure together with the first procedure, the base station central unit may determine that a second gap for the second procedure needs. Based on the determining, the base station central unit may transmit a request of the second gap to the base station distributed unit. For example, based on the determining, the base station central unit may transmit the request of the second gap and a first request of the first gap to the base station central unit.
In an example, the base station central unit may transmit to the base station distributed unit the request of a second gap for a second procedure of a wireless device. The base station central unit may receive a configuration of the second gap from the base station distributed unit.
In an example, the base station central unit may transmit to the base station distributed unit a message comprising the request of a second gap for a second procedure of a wireless device. The base station central unit may receive a response message comprising a configuration of the second gap from the base station distributed unit.
In an example, the base station central unit may transmit to the base station distributed unit the request of the second gap for second procedure and the information for the first procedure. The base station central unit may receive the configuration of the second gap from the base station distributed unit. For example, the base station central unit may transmit to the base station distributed unit a message comprising: the request of the second gap for second procedure; and the information for the first procedure. The base station central unit may receive a response message comprising the configuration of the second gap from the base station distributed unit. The base station central unit may transmit the configuration of the second gap to the wireless device. The wireless device may perform the second procedure based on the configuration of second gap.
In an example, the base station central unit may transmit to the base station distributed unit the request of the second gap for second procedure and the information for the first procedure. From the base station distributed unit, the base station central unit may receive the configuration of the second gap for the second procedure and the configuration of the first gap for the first procedure. In an example, the base station central unit may transmit to the base station distributed unit a message comprising: the request of the second gap for second procedure; and the information for the first procedure. From the base station distributed unit, the base station central unit may receive a response message comprising the configuration of the second gap for the second procedure and the configuration of the first gap for the first procedure. The base station central unit may transmit to the wireless device an RRC reconfiguration message the configuration of the second gap and the configuration of the first gap. The wireless device may perform the second procedure based on the configuration of the second gap and the first procedure based on the configuration of the first gap.
In an example, the message may be a message for management of a context of the wireless device. The message may be a context setup request message or a context modification request message.
In an example, the response message may be a message for management of a context of the wireless device. the response message may be a context setup response message or a context modification response message. The response message is a response to the message.
In an example, the request of the second gap may indicate that the wireless device needs the second gap. The request of the second gap may indicate that the wireless device needs to modify a gap, for the second procedure, configured to the wireless device. The request may further request the base station distributed unit to determine the second gap based on the information for the first procedure. The request may further request the base station distributed unit to modify/update the gap configured to the wireless device based on the information for the first procedure.
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In an example, a wireless device may transmit to a base station a request of a second gap for a second procedure.
In an example, the wireless device may transmit the request to the base station based on information for a first procedure. For example, the wireless device may transmit to the base station the request based on determining to transmit the information for the first procedure to the base station. The wireless device may transmit to the base station the request based on determining to transmit the assistance information for the first procedure to the base station.
In an example, the wireless device may transmit the request to the base station based on the information for a first procedure. For example, the wireless device may transmit to the base station the request based on determining to transmit to the base station information for a first procedure. The information for the first procedure may comprise at least one of: assistance information, for the first procedure, (e.g., transmitted by the wireless device); a gap, for the first procedure, determined (e.g., based on the assistance information) by the wireless device.
In an example, the wireless device may determine whether a first gap for the first procedure needs for the wireless device; whether the wireless device is able to perform the first procedure together with second procedure. For example, the second procedure may be a procedure which was configured to the wireless device. For example, based on the information for the first procedure, the wireless device may determine whether a first gap for the first procedure needs for the wireless device; whether the wireless device is able to perform the first procedure together with second procedure. The information for the first procedure may comprise at least one of: assistance information, for the first procedure, (e.g., transmitted by the wireless device); a gap, for the first procedure, determined (e.g., based on the assistance information) by the wireless device.
In an example, the wireless device may determine that the wireless device is not able to perform the first procedure together with the second procedure. Based on the determining, the wireless device may determine that the wireless device needs a gap for the first procedure and/or the second procedure. Based on the determining, the wireless device may transmit (e.g., via an RRC message) a request of the gap to the wireless device. The request of the gap may be a first request of the first gap for the first procedure; or a second request of the second gap for the second procedure; or a third request of a third gap for the first procedure and the second procedure. The request of the gap may indicate a procedure which the gap is applied. The procedure may indicate one or more procedures. The procedure may be the first procedure; or the second procedure; or both of the first procedure and the second procedure. Based on receiving the request of the gap, the base station may transmit the gap (or the configuration of the gap) (e.g., via an RRC reconfiguration message) to the wireless device. The gap or a configuration of the gap may indicate a procedure which the gap is applied. The wireless device may perform the first procedure and/or the second procedure based on the gap (or the configuration of the gap).
In an example, the wireless device may determine, that the wireless device is not able to perform the first procedure together with the second procedure, based on a first gap for the first procedure being overlapped with a gap, for the second procedure, configured to the wireless device; or a time, which the first procedure is configured to be performed, being overlapped with the gap, for the second procedure, configured to the wireless device; or the time, which the first procedure is configured to be performed, being overlapped with a second time, which the second procedure is configured to be performed.
In an example, the wireless device may determine whether the wireless device is not able to perform the first procedure together with the second procedure based on a capability of the wireless device. The wireless device may determine that the wireless device needs a gap for the first procedure and/or the second procedure based on the capability of the wireless device.
In an example, the wireless device may determine that the wireless device is not able to perform the second procedure together with the first procedure. Based on the determining, the wireless device may determine to transmit the request of the second gap for the second procedure. Based on the determining, the wireless device may transmit the request of the second gap to the wireless device. For example, based on the information for the first procedure, the wireless device may determine that the wireless device is not able to perform the second procedure together with the first procedure.
In an example, the wireless device may determine that the wireless device is not able to perform the second procedure together with the first procedure. For example, based on the information for the first procedure, the wireless device may determine that the wireless device is not able to perform the second procedure together with the first procedure. The determining that the wireless device is not able to perform the second procedure together with the first procedure may be further based on determining that the first gap for the first procedure needs for the wireless device. Based on the determining that the wireless device is not able to perform the second procedure together with the first procedure, the wireless device may determine that a second gap for the second procedure needs. Based on the determining, the wireless device may transmit a request of the second gap to the base station unit.
In an example, the wireless device may transmit to the base station the request of the second gap via an RRC message. A base station central unit of the base station may receive the RRC message. Based on receiving the request of the RRC message, the base station central unit may transmit the request to a base station distributed unit. Based on receiving the request, the base station distributed unit may transmit a configuration of the second gap to the base station central unit. Based on receiving the configuration of the second gap, the base station central unit may transmit an RRC reconfiguration comprising the configuration of the second gap to the wireless device. Based on the configuration of the second gap, the wireless device may perform the second procedure. For example, the RRC message may be a UE assistance information message.
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In an example, the request for the MUSIM gap may be the assistance information for the MUSIM gap.
In an example, the second gap may indicate that the second gap is able to be used for a procedure. the second gap may indicate that the wireless device is able to use the second gap for the procedure. For example, the procedure may indicate/comprise at least one of: the first procedure; and the other procedure (e.g., other than the first procedure).
In an example, the information for the measurement gap may further comprise at least one of: assistance information, for the measurement gap, received from a wireless device; and a first measurement gap determined by the bases station central unit.
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In an example, a base station distributed unit may receive from a base station central unit a message indicating information for a first procedure of a wireless device wherein the information is capable of being used to determine a first gap for the first procedure. The base station distributed unit may transmit, based on the information and to a base station central unit, a response message indicating a configuration of a second gap for a second procedure of the wireless device.
In an example, the transmitting the configuration of the second gap may be based on at least one of: determining to configure the second gap; determining to modify a first gap, for the second procedure, configured to the wireless device; determining that the wireless device is not able to perform the first procedure together with the second procedure; determining that the wireless device is not able to perform the first procedure; determining that the wireless device is not able to perform the second procedure; determining that a third gap, for the first procedure, determined by the base station distributed unit is overlapped with the first gap for the second procedure; determining that a fourth gap, for the first procedure, configured to the wireless device is overlapped with the first gap for the second procedure; and
In an example, the base station distributed unit may receive, from the base station central unit, a request for the second gap. The request may be a request that the base station central unit received from the wireless device. The base station distributed unit may receive the request via the message. The request may be a first request to configure the second gap; or a second request to modify the first gap.
In an example, the first procedure may be a procedure on a second network during a multi universal subscriber identity module (MUSIM) gap. The second procedure may be a measurement (procedure). The second gap may be a measurement gap and the information for the first procedure may be a parameter of a MUSIM gap for the first procedure.
In an example, the first procedure may be a measurement (procedure) and the second procedure may be a procedure on a second network during a multi universal subscriber identity module (MUSIM) gap. The second gap may be a MUSIM gap; and the information for the first procedure may comprise at least one of: a measurement configuration; and a measurement timing configuration.
In an example, a base station distributed unit may receive, from a base station central unit, a message indicating information for a first procedure of a wireless device wherein the wireless device is configured to perform a second procedure. The base station distributed unit may transmit, based on the information and to a base station central unit, a response message indicating a configuration of a second gap for a second procedure of the wireless device.
In an example, the base station distributed unit may determine the wireless device being configured to perform the second procedure based on at least one of: receiving, from the base station distributed unit, a configuration of the second procedure; transmitting, to the base station distributed unit, a configuration of a gap for the second procedure; and receiving, from the base station distributed unit, the configuration of the gap for the second procedure.
In an example, the first procedure may be a procedure on a second network during a multi universal subscriber identity module (MUSIM) gap. The second procedure may be a measurement (procedure). The second gap may be a measurement gap and the information for the first procedure may be a parameter of a MUSIM gap for the first procedure.
In an example, the first procedure may be a measurement (procedure) and the second procedure may be a procedure on a second network during a multi universal subscriber identity module (MUSIM) gap. The second gap may be a MUSIM gap; and the information for the first procedure may comprise at least one of: a measurement configuration; and a measurement timing configuration.
In an example, a base station central unit may transmit, to a base station distributed unit, a message indicating information for a first procedure of a wireless device wherein the parameter is capable of being used to determine a first gap for the first procedure. The base station central unit may receive, from the base station distributed unit, a response message indicating a configuration of a second gap for a second procedure of the wireless device.
In an example, the base station central unit may transmit, to the wireless device, a radio resource control (RRC) reconfiguration message indicating the configuration of the second gap for the second procedure.
In an example, the base station central unit may transmit, to the wireless device, a configuration of a first gap for the first procedure via the RRC reconfiguration message based on receiving, from the base station distributed unit, the configuration of the first gap.
In an example, the response message may indicate the configuration of the first gap.
In an example, the base station central unit may transmit, via the message, a request for the second gap based on at least one of: determining to configure the second gap for the second procedure; determining to modify a first gap, for the second procedure, configured to the wireless device; determining that the wireless device is not able to perform the first procedure together with the second procedure; determining that the wireless device is not able to perform the first procedure; determining that the wireless device is not able to perform the second procedure; determining that a fifth gap, for the first procedure, determined by the base station central unit is overlapped with the first gap for the second procedure; determining that a fourth gap, for the first procedure, configured to the wireless device is overlapped with the first gap for the second procedure; and receiving, from the base station central unit, a request for the second gap for the second procedure.
In an example, the base station central unit may transmit receive, from the wireless device, the request. The request may be a first request to configure the second gap for the second procedure; or a second request to modify the first gap for the second procedure.
In an example, the first procedure may be a procedure on a second network during a multi universal subscriber identity module (MUSIM) gap. The second procedure may be a measurement (procedure). The second gap may be a measurement gap and the information for the first procedure may be a parameter of a MUSIM gap for the first procedure.
In an example, the first procedure may be a measurement (procedure) and the second procedure may be a procedure on a second network during a multi universal subscriber identity module (MUSIM) gap. The second gap may be a MUSIM gap; and the information for the first procedure may comprise at least one of: a measurement configuration; and a measurement timing configuration.
In an example, a base station central unit may transmit, to a base station distributed unit, a message indicating information for a first procedure of a wireless device wherein the wireless device is configured to perform a second procedure. The base station central unit may receive, from the base station distributed unit, a response message indicating a configuration of a second gap for a second procedure of the wireless device.
In an example, The base station central unit may determine the wireless device being configured to perform the second procedure based on at least one of: transmitting, to the base station distributed unit, a configuration of the second procedure; transmitting, to the wireless device, the configuration of the second procedure; transmitting, to the base station distributed unit, a configuration of a gap for the second procedure; and transmitting, to the wireless device, the configuration of the gap for the second procedure.
In an example, the first procedure may be a procedure on a second network during a multi universal subscriber identity module (MUSIM) gap. The second procedure may be a measurement (procedure). The second gap may be a measurement gap and the information for the first procedure may be a parameter of a MUSIM gap for the first procedure.
In an example, the first procedure may be a measurement (procedure) and the second procedure may be a procedure on a second network during a multi universal subscriber identity module (MUSIM) gap. The second gap may be a MUSIM gap; and the information for the first procedure may comprise at least one of: a measurement configuration; and a measurement timing configuration.
In an example, a wireless device may receive, from a base station, a measurement configuration for measurement. The wireless device may transmit, to the base station, a request of a measurement gap for the measurement based on determining transmission of assistance information for a multi universal subscriber identity module (MUSIM) gap for a procedure wherein the assistance information indicates a preferred MUSIM gap of the wireless device.
In an example, a wireless device may transmit, to a base station, a request of a measurement gap for a measurement based on determining transmission of assistance information for a multi universal subscriber identity module (MUSIM) gap for a procedure wherein: the wireless device is configured to perform the measurement; and the assistance information indicates a preferred MUSIM gap of the wireless device.
In an example, the wireless device may determine, based on receiving, from the base station, a measurement configuration for the measurement, that the wireless device is configured to perform the measurement.
In example, the transmitting the request may be further based on at least one of: determining to configure the measurement gap; determining to modify a first measurement gap, for the measurement, configured to the wireless device; determining that the wireless device is not able to perform the measurement together with the procedure; determining that the wireless device is not able to perform the procedure; determining that the wireless device is not able to perform the measurement; and determining that the preferred MUSIM gap for the procedure is overlapped with the first measurement gap for the measurement; and determining that a first MUSIM gap configured to the wireless device is overlapped with the first measurement gap for the measurement.
In an example, the wireless device may receive from the base station and after the transmitting the request the measurement gap via an RRC reconfiguration message.
In an example, the RRC reconfiguration message may comprise a MUSIM gap.
In an example, the transmitting the request may comprise transmitting the request via an RRC message.
In an example, the RRC message may be a user equipment (UE) assistance information message.
In an example, the RRC message may comprise the assistance information for the MUSIM gap.
In an example, a base station distributed unit may receive, from a base station central unit, a first message indicating a measurement information for measurement of a wireless device wherein the wireless device is configured to perform the measurement; The base station distributed unit may transmit, based on the measurement information and to the base station central unit, a first response message indicating a configuration of a first measurement gap for the measurement of the wireless device; The base station distributed unit may receive, from the base station central unit, a second message indicating a parameter of a multi universal subscriber identity module (MUSIM) gap for a procedure of the wireless device. The base station distributed unit may transmit, based on the parameter and to the base station central unit, a second response message indicating a configuration of a second measurement gap for the measurement of the wireless device.
In an example, a base station distributed unit may receive, from a base station central unit, a message indicating a parameter of a multi universal subscriber identity module (MUSIM) gap for a procedure of a wireless device wherein the wireless device is configured to perform measurement. The base station distributed unit may transmit, based on the parameter and to the base station central unit, a response message indicating a configuration of a measurement gap for the measurement of the wireless device.
In an example, the transmitting the measurement gap may be based on at least one of: determining to configure the measurement gap; determining to modify a first measurement gap, for the measurement, configured to the wireless device; determining that the wireless device is not able to perform the measurement together with the procedure; determining that the wireless device is not able to perform the procedure; determining that the wireless device is not able to perform the measurement; determining that the MUSIM gap determined by the base station distributed unit is overlapped with the first measurement gap for the measurement; determining that a first MUSIM gap configured to the wireless device is overlapped with the first measurement gap for the measurement; and receiving, from the base station central unit, a request for the measurement gap.
In an example, the request may be a request that the base station central unit received from the wireless device.
In an example, the base station distributed unit may receive the request via the message. The request may be a first request to configure the measurement gap; or a second request to modify the first measurement gap.
In an example, the base station distributed unit may transmit, to the base station central unit, the first measurement gap based on receiving, from the base station central unit, at least one of: a measurement configuration for the wireless device; and a measurement timing configuration for the wireless device.
In an example, the message may be a context setup request message, or a context modification request message.
In an example, the response message may be a context setup response message, or a context modification response message.
In an example, the parameter may comprise at least one of: assistance information received from a wireless device; and a first MUSIM gap determined by the bases station central unit.
In an example, the assistance information may indicate a preference, of the wireless device, for the first MUSIM gap.
In an example, the parameter may comprise at least one of: a gap offset indicating a gap offset of a MUSIM gap; a gap length indicating a length of a MUSIM gap; and a gap repetition period indicating a gap repetition period of a MUSIM gap.
In an example, the base station distributed unit may determine, based on receiving, from the base station central unit, a measurement configuration of the wireless device, that the wireless device is configured to perform measurement.
In an example, the base station distributed unit may receive, from the base station central unit, a first message indicating a measurement information for the measurement of the wireless device wherein the wireless device is configured to perform the measurement. The base station distributed unit may transmit, based on the measurement information and to the base station central unit, a first response message indicating a configuration of a first measurement gap for the measurement of the wireless device.
In an example, the measurement information may comprise at least one of: a measurement configuration for the wireless device; and a measurement timing configuration for the wireless device.
In an example, the base station distributed unit may transmit, based on the parameter and to the base station central unit, a configuration of the MUSIM gap.
In an example, the response message may indicate the configuration of the MUSIM gap.
In an example, the MUSIM gap may be a time duration in which the wireless device is allowed to communicate with a second device without releasing a connection of a first network; or the measurement gap is a time duration in which the wireless device is allowed to perform a measurement.
In an example, the base station distributed unit may be a base station distributed unit of the first network; and the base station central unit is a base station central unit of the first network.
In an example, the second device may be: a second base station of a second network; or a second wireless device.
In an example, the wireless device may comprise; a first universal subscriber identity module (USIM) being associated with the first network; and a second USIM being associated with the second network.
In an example, the first network may be associated with a first public land mobile network (PLMN); and the second network is associated with a second PLMN.
In an example, the connection may comprise at least one of: an RRC connection; and an (N1) NAS signalling connection.
In an example, the communicating may comprise at least one of: monitoring a channel of the second device; receiving a signal from the second device; transmitting a signal to the second device; and performing measurement on a cell/frequency of the second device.
In an example, the wireless device may be not capable of concurrent communication to multiple devices.
In an example, the wireless device being not capable of concurrent communication to multiple devices may be based on at least one of: the wireless device having single transmitter; the wireless device having single receiver; the wireless device not supporting the concurrent communication on radio frequencies of the multiple device; and the wireless device not supporting the concurrent communication on radio access technologies of the multiple devices.
In an example, a base station central unit may receive, from a base station distributed unit, a first response message indicating a configuration of a first measurement gap for measurement of a wireless device wherein the wireless device is configured to perform the measurement. The base station central unit may transmit, to the wireless device, a radio resource control (RRC) reconfiguration message comprising the configuration of the first measurement gap; The base station central unit may transmit, to the base station distributed unit, a second message indicating a parameter of a multi universal subscriber identity module (MUSIM) gap for a procedure of the wireless device. The base station central unit may receive, from the base station distributed unit and based on the parameter, a second response message indicating a configuration of a second measurement gap for the measurement of the wireless device.
In an example, a base station central unit may transmit, to a base station distributed unit, a message indicating a parameter of a multi universal subscriber identity module (MUSIM) gap for a procedure of a wireless device wherein the wireless device is configured to perform the measurement. The base station central unit may receive, from the base station distributed unit, a response message indicating a configuration of a measurement gap for the measurement of the wireless device.
In an example, the base station central unit may transmit, to the wireless device, a radio resource control (RRC) reconfiguration message indicating the configuration of the measurement gap.
In an example, the base station central unit may transmit, to the wireless device, a configuration of the MUSIM gap via the RRC reconfiguration message based on receiving, from the base station distributed unit, the configuration of the MUSIM gap.
In an example, the response message may indicate the configuration of the MUSIM gap.
In an example, the base station central unit may determine the wireless device being configured to perform the measurement based on transmitting a measurement configuration for the measurement to the wireless device; or transmitting a measurement configuration for the measurement to the base station distributed unit.
In an example, the base station central unit may transmit, via the message, a request for the measurement gap based on at least one of: determining to configure the measurement gap; determining to modify a first measurement gap, for the measurement, configured to the wireless device; determining that the wireless device is not able to perform the measurement together with the procedure; determining that the wireless device is not able to perform the procedure; determining that the wireless device is not able to perform the measurement; determining that a MUSIM gap, for the procedure, determined by the base station central unit is overlapped with the first measurement gap for the measurement; determining that a first MUSIM gap configured to the wireless device is overlapped with the first measurement gap for the measurement; and receiving, from the wireless device, the request for the measurement gap.
In an example, the base station central unit may receive, from the wireless device, the request. The request may be a first request to configure the measurement gap; or a second request to modify the first measurement gap.
In an example, the base station central unit may receive, from the base station distributed unit, the first measurement gap based on transmitting, to the base station distributed unit, at least one of: a measurement configuration for the wireless device; and a measurement timing configuration for the wireless device.
In an example, the base station central unit may receive, from the base station distributed unit, a first response message indicating a configuration of a first measurement gap for the measurement of the wireless device wherein the wireless device is configured to perform the measurement. The base station central unit may transmit, to the wireless device, a second RRC reconfiguration message comprising the configuration of the first measurement gap.
In an example, the receiving the first response message may be after transmitting, to the base station distributed unit, a first message indicating a measurement information for measurement of the wireless device wherein the wireless device is configured to perform the measurement.
In an example, a base station distributed unit may receive, from a base station central unit, a first message indicating a parameter of a first multi universal subscriber identity module (MUSIM) gap for a procedure of a wireless device. The base station distributed unit may transmit, based on the parameter and to the base station central unit, a first response message indicating a configuration of the first MUSIM gap for the procedure of the wireless device. The base station distributed unit may receive, from the base station central unit, a second message comprising measurement information of measurement of the wireless device. The base station distributed unit may transmit, based on the measurement information and to the base station central unit, a second response message indicating a configuration of a second MUSIM gap for the procedure of the wireless device.
In an example, a base station distributed unit may receive, from the base station central unit, a message comprising measurement information of measurement of the wireless device wherein the wireless device is configured with a first multi universal subscriber identity module (MUSIM) gap for a procedure. The base station distributed unit may transmit, based on the measurement information and to the base station central unit, a response message indicating a configuration of a second MUSIM gap for the procedure of the wireless device.
In an example, the transmitting the second MUSIM gap may be based on at least one of: determining to configure the second MUSIM gap; determining to modify the first MUSIM gap; determining that the wireless device is not able to perform the measurement together with the procedure; determining that the wireless device is not able to perform the procedure; determining that the wireless device is not able to perform the measurement; determining that a measurement gap determined by the base station distributed unit is overlapped with the first MUSIM gap; determining that a first measurement gap configured to the wireless device is overlapped with the first MUSIM gap; and receiving, from the base station central unit, a request for the second MUSIM gap.
In an example, the request may be a request that the base station central unit received from the wireless device.
In an example, the base station distributed unit may receive the request via the message. The request may be a first request to configure the second MUSIM gap; or a second request to modify the second MUSIM gap.
In an example, the base station distributed unit may transmit, to the base station central unit, the first MUSIM gap based on receiving, from the base station central unit, a parameter of the first multi MUSIM gap for a procedure of a wireless device.
In an example, the parameter may comprise at least one of: assistance information received from a wireless device; and a third MUSIM gap determined by the bases station central unit.
In an example, the assistance information may indicate preference, of the wireless device, for the first MUSIM gap.
In an example, the parameter may comprise at least one of: a gap offset indicating a gap offset of a MUSIM gap; a gap length indicating a length of a MUSIM gap; and a gap repetition period indicating a gap repetition period of a MUSIM gap.
In an example, the message may be a context setup request message or a context modification request message.
In an example, the response message may be a context setup response message or a context modification response message.
In an example, the base station distributed unit may determine, based on transmitting, to the base station central unit, a configuration of the first MUSIM gap of the wireless device.
In an example, a base station distributed unit may receiving, from the base station central unit, a first message indicating a parameter of the first MUSIM gap for the procedure of the wireless device. The base station distributed unit may transmit, based on the parameter and to the base station central unit, a first response message indicating a configuration of the first MUSIM gap for the procedure of the wireless device.
In an example, the base station distributed unit may transmit, based on the measurement information and to the base station central unit, a measurement gap.
In an example, wherein the response message indicates a configuration of the measurement gap.
In an example, wherein the measurement information comprises at least one of: a measurement configuration for the wireless device; and a measurement timing configuration for the wireless device.
In an example, a base station central unit may receive, from a base station distributed unit, a first response message indicating a configuration of a first multi universal subscriber identity module (MUSIM) gap for a procedure of a wireless device. The base station central unit may transmit, to the wireless device, a radio resource control (RRC) reconfiguration message comprising the configuration of the first MUSIM gap. The base station central unit may transmit, to the base station distributed unit, a second message comprising measurement information of measurement of the wireless device. The base station central unit may receive, from the base station distributed unit, a second response message indicating a configuration of a second MUSIM gap for the procedure of the wireless device.
In an example, a base station central unit may transmit, to a base station distributed unit, a message comprising measurement information of measurement of the wireless device wherein the wireless device is configured with a first multi universal subscriber identity module (MUSIM) gap for a procedure. The base station central unit may receive, from the base station distributed unit, a response message indicating a configuration of a second MUSIM gap for the procedure of the wireless device.
In an example, the base station central unit may transmit, to the wireless device, a radio resource control (RRC) reconfiguration message indicating the configuration of the second MUSIM gap.
In an example, the base station central unit may transmit, to the wireless device, a configuration of measurement gap for the measurement via the RRC reconfiguration message based on receiving, from the base station distributed unit, the configuration of the measurement gap.
In an example, the response message may indicate the configuration of the measurement gap.
In an example, the base station central unit may determine the wireless device being configured with the first MUSIM gap based on receiving, from the base station distributed unit, a configuration of the first MUSIM gap.
In an example, the base station central unit may transmit, via the message, a request for the second MUSIM gap based on at least one of: determining to configure the second MUSIM gap; determining to modify the first MUSIM gap; determining that the wireless device is not able to perform the measurement together with the procedure; determining that the wireless device is not able to perform the procedure; determining that the wireless device is not able to perform the measurement; determining that a first measurement gap configured to the wireless device is overlapped with the first MUSIM gap; and receiving, from the wireless device, the request for the second MUSIM gap.
In an example, the base station central unit may receive, from the wireless device, the request. The request may be a first request to configure the second MUSIM gap; or a second request to modify the first MUSIM gap.
In an example, the base station central unit may receive, from the base station distributed unit, the first measurement gap based on transmitting, to the base station distributed unit, at least one of: a measurement configuration for the wireless device; and a measurement timing configuration for the wireless device.
In an example, the base station central unit may receive, by the base station central unit from the base station distributed unit, a first response message indicating a configuration of the first MUSIM gap. The base station central unit may transmit, to the wireless device, a second RRC reconfiguration message comprising the configuration of the first MUSIM gap.
In an example, the receiving the first response message may be after transmitting, to the base station distributed unit, a first message indicating a parameter measurement of the first MUSIM gap for the procedure of the wireless device.
This application is a continuation of International Application No. PCT/US2023010125, filed Jan. 4, 2023, which claims the benefit of U.S. Provisional Application No. 63/296,773, filed Jan. 5, 2022, all of which are hereby incorporated by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| 63296773 | Jan 2022 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US2023/010125 | Jan 2023 | WO |
| Child | 18748748 | US |
