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 a 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 μs; 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 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:
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., recoverySearchSpaceId). 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.
5G network may provide service for various kinds of vertical industries and various kinds of users. Existing 5G quality of service (QOS) requirements may not be sufficient to provide good user experience for all the user requirements. Thus in the 5G network, it is necessary to collect the user key performance indicators (KPI) information, e.g., application layer end-to-end reliability statistic indicator, etc. For example, KPIs for characterizing insufficient video streaming performance (e.g., as perceived by the user) comprise initial stalling of the playout; periods of stalling and freezing of the video while playing; interruption of the audio while playing; low coding quality appearing as blurring, macroblocking or mosquito artefacts; and/or varying coding quality while playing. KPIs and other information may be collected (e.g., by a network, measurement collection entity (MCE) of the network, etc.). The collected information may be used to determine and/or manage the user's Quality of Experience (QoE). QoE support may be useful for any service type, for example, streaming services, multimedia telephony services for IMS (MTSI), multimedia broadcast and multicast services (MBMS), augmented reality (AR), virtual reality (VR), extended reality (XR), video streaming services, etc. In addition to the QoE metrics, the radio related measurements and information to assist the NR QoE management functionality are considered.
New radio (NR) and long-term evolution (LTE) support an application layer measurement collection functionality for QoE. This functionality enables the collection of application layer measurements from a user equipment (UE) or one or more UEs in an area. The collected information is transported to a collection center (e.g., MCE), where it can be analyzed.
Initiation of measurement collection may be signaling-based or management-based. For the signaling-based case (an example of which is shown in
In an example, the QoE measurement configuration parameters and/or information may comprise at least one of: a container for application layer measurement configuration, a measurement configuration application layer identifier, a list of cell identifiers for quality of experience measurement configuration (QMC), a list of tracking area identities (TAIs) for QMC, a list of public land mobile networks (PLMNs) for QMC, a service type of a service of the wireless device associated with QMC, a QoE reference; a measurement collection entity (MCE) IP address, a list of single network slice selection assistance information (S-NSSAls) associated with the QMC, and/or the like.
In an example, the service type of the service of the wireless device associated with QMC may comprise at least one of: a streaming service, a multimedia telephony service for IMS (MTSI) service, a virtual reality (VR) service, an extended reality (XR) service, a multimedia broadcast and multicast service (MBMS), a multicast broadcast service (MBS), and/or the like.
In an example, the application layer measurement configuration parameters may comprise at least one of: an average throughput of streaming services and/or VR services, an initial playout delay of streaming services and/or VR services, a buffer level status streaming services and/or VR services, a list of playback periods (play list) of streaming services and/or VR services, a successive loss of real-time transport protocol packets of MTSI services, a frame rate of MTSI services, a jitter duration of MTSI services, a sync loss duration of MTSI services, a round-trip time of MTSI services, an average codec bitrate of MTSI services, a call setup time for MTSI service of MTSI services, a comparable quality viewport switching latency of VR services, a list of viewports that have been rendered during the media presentation of VR services, and/or the like.
The base station may send the QoE measurement configuration parameters and/or information to the UE. The QoE measurement configuration parameters and/or information may be sent in a radio resource control (RRC) message. The QoE measurement configuration parameters and/or information may be received by an access stratum (AS) layer of the UE. The AS layer of the UE may send the QoE measurement configuration parameters and/or information to an application layer of the UE. Configuration and reporting for multiple simultaneous QoE measurements for a UE may be supported.
The UE may perform one or more measurements based on the QoE measurement configuration parameters and/or information. For example, UE may perform QoE metric comprising average throughput, initial playout delay, buffer level status, a list of playback periods (play list) for streaming and VR services. UE may perform QoE metric comprising successive loss of real-time transport protocol packets, frame rate, jitter duration, sync loss duration, round-trip time, average codec bitrate, call setup time for MTSI service. For VR services, UE may additional perform QoE metric comprising comparable quality viewport switching latency, a list of viewports that have been rendered during the media presentation. One or more results of the measurements may be used to generate a QoE report.
The UE application layer may send the QoE report to the UE AS layer. The UE AS layer may send the QoE report to the base station. The QoE report may be sent in an RRC message. The QoE report may be sent via a separate signaling radio bearer (SRB) in NR. The base station may transmit the QoE report to the configured destination, e.g., a measurement collection entity (MCE). RRC segmentation may be needed for transmission of QoE reports, and any potential solutions need detailed technical specification of the procedures. Management based QoE configuration should not override signaling based QoE configuration.
In the signaling-based deactivation procedure, deactivation of the QoE measurements is configured by the OAM and triggered by the CN. The CN may initiate the deactivation of QoE measurement as configured by OAM and may send the deactivation indication to the NG-RAN node to indicate which QoE measurement should be deactivated. The NG-RAN node may send the deactivation indication to the UE AS layer, and then the UE AS layer may send the deactivation indication to the UE application layer.
In the management-based activation procedure, measurement and reporting aspects may be similar to the signaling-based activation procedure described above.
In the management-based deactivation procedure, deactivation of the QoE measurements is configured and triggered by the OAM. OAM may send the deactivation configuration to the base station to indicate which QoE measurement should be deactivated. If the NG-RAN node receives the indication that the QoE measurement configuration is to be deactivated, then NG-RAN node may send the deactivation indication to the UE AS layer, and the UE AS layer may send it to the application layer in UE.
In an example, QoE measurement triggering and stopping can be realized using time-based and/or threshold-based criteria, configured by the OAM. Threshold-based QoE measurement triggering and stopping allows to start and stop QoE measurement when given thresholds are passed.
In an example, an NG-RAN node may issue a release of QoE measurement configuration for UEs previously configured for QoE measurement reporting, provided that the session for which the QoE measurements are reported is completed. RAN may need to release an ongoing QoE measurement configuration or QoE reporting configuration, e.g. if handing over to a network that does not support this.
In an example, RAN, in case of overload in standalone connectivity, may stop new QoE measurement configurations, may release existing QoE measurement configurations and may pause QoE measurement reporting. RRC signaling may be used by the gNB to indicate the UE to pause or resume the QoE reporting.
In an example, seamless mobility may be a key functionality in NR and its impacts should be measurable at the application layer. To enable measuring the impact of the mobility on the application and users' QoE, it may be required to support QoE measurement reporting continuity in intra-system intra-RAT intra-node and inter-node mobility scenarios: for intra-node mobility for both management-based and signaling-based QoE. At least signaling-based QoE supports this also in case of inter-node mobility.
In an example, to support the QoE measurement in LTE mobility scenarios, the QoE configuration may be forwarded from the source eNB to the target eNB inside the Trace Activation IE over the X2 interface. The same information may be sent over the S1 interfaces for mobility scenarios when the X2 interface is not established between the source and the target. In NR, to support mobility for QoE measurements in RRC CONNECTED state, the QoE measurement configuration transfer may be supported on the Xn and NG interfaces, inside the Trace Activation IE as a part of UE Application Layer Measurement Configuration IE that may contain multiple QoE configurations for multiple service types. QoE measurements in RRC IDLE and RRC INACTIVE state can be supported for MBS. To support keeping QoE measurement configuration in RRC INACTIVE state mobility, QoE measurement configuration for a UE may be fetched from the node hosting the UE Context.
In addition, the requirements for QoE measurements stipulate that the client may check the QoE configuration when a session starts. This means that the client may continue the QoE measurements for an ongoing session even if the UE moves out of the configured area. The requirements are RAT independent and may therefore be applied to the mobility solution for QoE measurement in NR as well. QoE measurement reporting continuity in intra-system inter-RAT mobility scenarios may be supported. QoE measurement reporting continuity in inter-system mobility scenarios may be supported as well.
In an example, RAN (eNB or gNB) may not be able to understand or make use of the legacy QoE metrics as they are assembled by the OAM, sent inside containers and intended to be processed by the Measurement Collection Entity in the network. If the eNB or gNB needs to make use of the QoE concept, there might be requirements that QoE information should be visible by the eNB or gNB. RAN-visible QoE information is simplified QoE information abstracted from QoE metrics by UE, which the eNB or gNB may use for various types of enhancement. The RAN-visible QoE can be used for all services. RAN may be responsible for assembling the RAN-visible QoE measurement configuration. The RAN may be responsible for triggering e.g., activating the RAN-visible QoE measurement. The RAN may be able to configure RAN-visible QoE autonomously for a given service type if the application layer QoE for the same service type is already configured. The RAN-visible QoE value can be generated by UE and QoE server. RAN generating RAN-visible QoE values may require that RAN reads the QoE report in XML format.
The UE may receive and apply the RAN-visible QoE configuration and/or QoE measurement configuration container. The RAN-visible QoE configuration may be so that the corresponding RAN-visible QoE information that is reported can be a unique value or a combination of values reflecting the QoE metrics useful for RAN (e.g., buffer level), e.g., RAN visible QoE metrics. The RAN-visible report may be provided from the application layer of the UE to the UE's RRC layer by means of an AT command. The UE's RRC layer then may include the RAN-visible report, along with the QoE report container, but as a separate IE, in the MeasReportAppLayer IE, and may send it to the RAN. The NG-RAN node may read the RAN-visible QoE information and/or may forward the (legacy) QoE report container to the QoE server accordingly. Alternatively, the OAM server may generate the RAN-visible QoE report and may send it to the RAN.
In an example, the RAN visible QoE metrics may comprise at least one of: a buffer level, a playout delay for media startup, an application layer buffer level, an initial playout delay, a round-trip time, a jitter duration, a correction duration, an average throughput, a device information, rendered viewports, a codec information, representation switch events, play list (e.g., a list of playback periods), a media presentation description (MPD) information, an interactivity summary, an interactivity event list, and/or the like.
In an example, the RAN could also trigger radio-related measurements towards a certain UE for the network to further evaluate and improve the QoE, based on the QoE measurement configuration parameters and/or information received from the OAM. For triggering the measurements, an existing mechanism can be used. Collection of radio related measurements may be done by existing methods such as Minimization of Drive-Tests (MDT). The radio related QoE measurements may be reported for all types of supported services, which may include additional measurements related to the radio interface. If new radio-related measurements, with respect to what is currently specified in MDT, are required for NR QoE management, these additional radio-related QoE measurements may be performed as a part of MDT measurements. Application-related QoE measurements may be collected when the application session is ongoing. If these radio-related measurements are used for assisting application-related QoE measurements, it is efficient if measurement collection and reporting can start at the same time. If configured together e.g., using same trace reference and time aligned, e.g., based on time stamps, correlation of the results may be done by post processing. Besides radio-related measurement results, radio-related information may also be reported. Radio-related information may be reported even when radio-related measurements are not triggered over the radio. Both radio-related measurement results and radio-related information may be aligned and correlated with the QoE report.
In an example, the OAM/CN may transmit the QoE measurement configuration parameters and/or information to the NG-RAN node, including slice scope (a list of single network slice selection assistance information (S-NSSAIs). The NG-RAN node may map the slice scope to the ongoing PDU session list and may send the QoE measurement configuration with the PDU session list to the UE. The UE may receive the QoE measurement configuration and may send it to the corresponding application layer according to the PDU session list. The UE may send the QoE report with PDU session ID to NG-RAN node. The NG-RAN node may remap the PDU session ID back to slice ID (S-NSSAI) and attach it in the QoE report. The NG-RAN node may forward the QoE report with slice ID to the MCE.
In an example, the OAM or CN may transmit the QoE measurement configuration parameters and/or information to the NG-RAN node, including Slice Scope. The NG-RAN node may check the slice scope with the ongoing PDU sessions and may send the QoE measurement configuration parameters and/or information to a UE with qualified PDU session including slice scope. The UE may receive the QoE measurement configuration and may send it to the corresponding application layer according to the slice scope. The mapping may be performed in application layer or in access stratum (AS) layer. The UE may send the QoE report with slice ID to the NG-RAN node. The NG-RAN node may forward the QoE report with slice ID to the MCE.
In an example, the OAM or CN may transmit the QoE measurement configuration parameters and/or information to the NG-RAN node including the associated slice ID, outside the QoE configuration container, e.g., visible to the RAN. The NG-RAN node may check the slice ID against the ongoing PDU sessions, and sends QoE measurement configuration parameters and/or information to a UE with qualified PDU session, including slice ID. The UE may receive the QoE measurement configuration parameters and/or information and perform QoE measurements. The UE may send the QoE report to the NG-RAN node and may add the slice ID outside the QoE report container. The NG-RAN node may forwards the QoE report with slice ID to the MCE.
When multi connectivity is configured for a wireless device 210 (e.g., via an RRC reconfiguration message), the wireless device 210, which may support multiple reception/transmission functions in an RRC connected state, may be configured to utilize radio resources provided by multiple schedulers of a multiple base stations. Multiple base stations may be inter-connected via a non-ideal or ideal backhaul (e.g., Xn interface, X2 interface, and/or the like). A base station involved in multi connectivity for a certain wireless device may perform at least one of two different roles: a base station may either act as a master base station or as a secondary base station. In multi connectivity, a wireless device may be connected to one master base station and one or more secondary base stations. In an example, a master base station (e.g., the MN 2030) may provide a master cell group (MCG) comprising a primary cell and/or one or more secondary cells for a wireless device (e.g., the wireless device 210). A secondary base station (e.g., the SN 2050) may provide a secondary cell group (SCG) comprising a primary secondary cell (PSCell) and/or one or more secondary cells for a wireless device (e.g., the wireless device 210).
In multi connectivity, a radio protocol architecture that a bearer employs may depend on how a bearer is set up. In an example, three different type of bearer setup options may be supported: an MCG bearer, an SCG bearer, and/or a split bearer. A wireless device may receive/transmit packets of an MCG bearer via one or more cells of the MCG, and/or may receive/transmits packets of an SCG bearer via one or more cells of an SCG. Multi-connectivity may also be described as having at least one bearer configured to use radio resources provided by the secondary base station. Multi-connectivity may or may not be configured/implemented in some of the example embodiments.
In an example, a wireless device (e.g. Wireless Device 210) may transmit and/or receive: packets of an MCG bearer via an SDAP layer (e.g. SDAP 2010), a PDCP layer (e.g. NR PDCP 2011), an RLC layer (e.g. MN RLC 2014), and a MAC layer (e.g. MN MAC 2018); packets of a split bearer via an SDAP layer (e.g. SDAP 2010), a PDCP layer (e.g. NR PDCP 2012), one of a master or secondary RLC layer (e.g. MN RLC 2015, SN RLC 2016), and one of a master or secondary MAC layer (e.g. MN MAC 2018, SN MAC 2019); and/or packets of an SCG bearer via an SDAP layer (e.g. SDAP 2010), a PDCP layer (e.g. NR PDCP 2013), an RLC layer (e.g. SN RLC 2017), and a MAC layer (e.g. MN MAC 2019).
In an example, a master base station (e.g. MN 2030) and/or a secondary base station (e.g. SN 2050) may transmit/receive: packets of an MCG bearer via a master or secondary node SDAP layer (e.g. SDAP 2020, SDAP 2040), a master or secondary node PDCP layer (e.g. NR PDCP 2021, NR PDCP 2042), a master node RLC layer (e.g. MN RLC 2024, MN RLC 2025), and a master node MAC layer (e.g. MN MAC 2028); packets of an SCG bearer via a master or secondary node SDAP layer (e.g. SDAP 2020, SDAP 2040), a master or secondary node PDCP layer (e.g. NR PDCP 2022, NR PDCP 2043), a secondary node RLC layer (e.g. SN RLC 2046, SN RLC 2047), and a secondary node MAC layer (e.g. SN MAC 2048); packets of a split bearer via a master or secondary node SDAP layer (e.g. SDAP 2020, SDAP 2040), a master or secondary node PDCP layer (e.g. NR PDCP 2023, NR PDCP 2041), a master or secondary node RLC layer (e.g. MN RLC 2026, SN RLC 2044, SN RLC 2045, MN RLC 2027), and a master or secondary node MAC layer (e.g. MN MAC 2028, SN MAC 2048).
In multi connectivity, a wireless device may configure multiple MAC entities: one MAC entity (e.g., MN MAC 2018) for a master base station, and other MAC entities (e.g., SN MAC 2019) for a secondary base station. In multi-connectivity, a configured set of serving cells for a wireless device may comprise two subsets: an MCG comprising serving cells of a master base station, and SCGs comprising serving cells of a secondary base station. For an SCG, one or more of following configurations may be applied: at least one cell of an SCG has a configured UL CC and at least one cell of a SCG, named as primary secondary cell (PSCell, PCell of SCG, or sometimes called PCell), is configured with PUCCH resources; when an SCG is configured, there may be at least one SCG bearer or one Split bearer; upon detection of a physical layer problem or a random access problem on a PSCell, or a number of NR RLC retransmissions has been reached associated with the SCG, or upon detection of an access problem on a PSCell during a SCG addition or a SCG change: an RRC connection re-establishment procedure may not be triggered, UL transmissions towards cells of an SCG may be stopped, a master base station may be informed by a wireless device of a SCG failure type, for split bearer, a DL data transfer over a master base station may be maintained; an NR RLC acknowledged mode (AM) bearer may be configured for a split bearer; PCell and/or PSCell may not be de-activated; PSCell may be changed with a SCG change procedure (e.g. with security key change and a RACH procedure); and/or a bearer type change between a split bearer and a SCG bearer or simultaneous configuration of a SCG and a split bearer may or may not supported.
With respect to interaction between a master base station and a secondary base stations for multi-connectivity, one or more of the following may be applied: a master base station and/or a secondary base station may maintain RRM measurement configurations of a wireless device; a master base station may (e.g. based on received measurement reports, traffic conditions, and/or bearer types) may decide to request a secondary base station to provide additional resources (e.g. serving cells) for a wireless device; upon receiving a request from a master base station, a secondary base station may create/modify a container that may result in configuration of additional serving cells for a wireless device (or decide that the secondary base station has no resource available to do so); for a UE capability coordination, a master base station may provide (a part of) an AS configuration and UE capabilities to a secondary base station; a master base station and a secondary base station may exchange information about a UE configuration by employing of RRC containers (inter-node messages) carried via Xn messages; a secondary base station may initiate a reconfiguration of the secondary base station existing serving cells (e.g. PUCCH towards the secondary base station); a secondary base station may decide which cell is a PSCell within a SCG; a master base station may or may not change content of RRC configurations provided by a secondary base station; in case of a SCG addition and/or a SCG SCell addition, a master base station may provide recent (or the latest) measurement results for SCG cell(s); a master base station and secondary base stations may receive information of SFN and/or subframe offset of each other from OAM and/or via an Xn interface, (e.g. for a purpose of DRX alignment and/or identification of a measurement gap). In an example, when adding a new SCG SCell, dedicated RRC signaling may be used for sending required system information of a cell as for CA, except for a SFN acquired from a MIB of a PSCell of a SCG.
In this disclosure, “radio resource management” may be interpreted as “modify radio resources”; “adjust radio resources”; “enhance radio resources”; “configure and/or reconfigure radio resources”; “allocate and/or reallocate radio resources”; and/or the like.
QoE metrics may enable wireless devices to measure user experience at the level of the application layer. For example, a choppy video stream may be reflected by poor QoE metrics. QoE metrics may be reported and/or compiled at a central server (e.g., MCE). Additionally or alternatively, QoE metrics may be reported to one or more base stations. QoE metrics that are available to a base station may be referred to as RAN-visible. For example, an application layer buffer level of a video stream service in a wireless device may be measured as low by the wireless device, which may be subsequently reported to a base station. The base station may use the data to improve the radio resource management for the wireless device so that the application layer buffer level in the wireless device finally gets to be high enough. Thus, the user experience on the video stream service is improved for the wireless device.
In existing technologies, a problem arises if the base station which receives the report is not the sole provider of the service associated with the report. For example, a problem arises if a first base station receives a QoE report for a service that is provided, at least in part, by a second base station. The first base station may receive a QoE report from the wireless device. The first base station may use the QoE report to adjust the provision of the service (e.g., reallocate radio resources of the first base station). However, the adjustment made by the first base station may not be effective, since the first base station is not the sole provider of the service. Additionally or alternatively, the second base station may not have access to the QoE report, and may be unaware that an adjustment is necessary and/or unable to adjust effectively. The existing technologies may not be effective for improving network performance and user experience.
To improve the provision of the service, the network may use radio resources of BS2. For example, BS1 may configure the wireless device and/or BS2 for dual connectivity. BS1 may be a master base station and BS2 may be a secondary base station (e.g., secondary node). The service may be provided via radio resources of both the master base station and the secondary base station. The radio resources may be physical layer radio resources. The radio resources may be associated with one or more PDU sessions, one or more bearers (e.g., radio bearers, data radio bearers (DRBs)), and/or one or more QoS flows.
In an example, to configure dual connectivity, BS1 may send, to BS2, a secondary node (SN) modification request message and/or SN addition request message comprising at least one of: QoS information; UE capability information; and/or the like to BS2, requesting BS2 to allocate resources for one or more PDU Sessions, DRBs and/or QoS Flows. BS2 may determine to admit the resource request from BS1 and may allocate respective radio resources associated with the PDU Sessions, DRBs and/or QoS Flows. BS2 may send to BS1 SN modification request acknowledge message and/or SN addition request acknowledge message comprising a SCG radio resource configuration. BS1 may send to the wireless device an RRC reconfiguration message comprising the SCG radio resource configuration. The wireless device may apply the SCG radio resource configuration and reply to BS1 a RRC reconfiguration complete message, which may be forwarded to BS2.
In an example, BS1 may provide the service via a master cell group (MCG) bearer (e.g., DRB1) and BS2 may provide the service via a secondary cell group (SCG) bearer (e.g., DRB2). Both of DRB1 and DRB2 may be associated with the service.
In an example, BS1 may provide the service via a first portion of an MCG split bearer and BS2 may provide the service via a second portion of the MCG split bearer. The MCG split bearer may be associated with the service.
In an example, BS1 may provide the service via a first portion of an SCG split bearer and BS2 may provide the service via a second portion of the SCG split bearer. The SCG split bearer may be associated with the service.
In an example, BS1 may provide the service via one or more QoS flows of BS1 (e.g., QoS flow 1A, QoS flow 1B, . . . . QoS flow 1n) and BS2 may provide the service via one or more QoS flows of BS2 (e.g., QoS flow 2A, QoS flow 2B, . . . . QoS flow 2n). The QoS flows of BS1 and BS2 may be associated with the service.
BS1 may receive (and/or continue to receive) QoE reports after BS2 begins to provide at least a portion of the service to the wireless device (e.g., BS2 allocates radio resources for the service). However, BS1 may not be able to effectively adjust provision of the service, because BS1 is not the sole provider of the service. Additionally or alternatively, BS2 may not have access to the QoE report, and may be unaware that an adjustment is necessary and/or unable to adjust effectively.
To improve the provision of the service, the network may use radio resources of a BS2. For example, BS1 may offload provision of the service to BS2. BS1 may be a master base station, but the service may be provided by a second (secondary) base station. BS1 may be a master base station and BS2 may be a secondary base station. The service may be provided via radio resources of the secondary base station. The radio resources may be physical layer radio resources. The radio resources may be associated with one or more PDU sessions, one or more bearers, and/or one or more QoS flows (as described previously).
BS1 may receive (and/or continue to receive) QoE reports after or during the service is offloaded to BS2.
However, BS1 may not be able to effectively adjust provision of the service, because BS1 is not the sole provider of the service. Additionally or alternatively, BS2 may not have access to the QoE report, and may be unaware that an adjustment is necessary and/or unable to adjust effectively.
BS2 may configure the wireless device for QoE reporting relating to the offloaded service. The service configured for QoE reporting may be a QoE-sensitive service (e.g., video streaming, VR, etc.). BS1 may reverse the offloading of the offloaded service (e.g., take back provision of the service from BS2). BS2 may receive (and/or continue to receive) QoE reports after or during the offloading of the service is reversed by BS1. However, BS1 may not have access to the QoE report, and may be unaware that an adjustment is necessary and/or unable to adjust effectively.
In existing technologies, as illustrated with specific examples in
In example embodiments, a first base station sends, to a second base station, a message comprising one or more QoE measurement results associated with a service. The message comprises packet flow information of a packet flow associated with the one or more QoE measurement results. By sending the one or more QoE measurement results associated with the service to the second base station, the first base station may enable the second base station to efficiently provide the service to the wireless device. For example, the second base station may efficiently allocate, reallocate, modify, and/or adjust one or more radio resources associated with the service. In accordance with the example embodiments, the network may leverage QoE reporting to improve provision of a service, even in a scenario wherein the base station that receives the report is not a sole provider of the service (e.g., a dual connectivity scenario).
In existing technologies, even if the second base station were to obtain the QoE report, the second base station may not be capable of using the QoE report to improve the service. For example, even if the QoE report indicates that the provision of a particular service should be improved, the second base station may not be capable of determining which radio resources are associated with that particular service. For example, the second base station may not be capable of determining which particular radio resources to allocate, reallocate, adjust, and/or modify.
In example embodiments, the second base station receives packet flow information from the first base station. The packet flow information enables the second base station to identify one or more particular radio resources that are associated with the service. For example, the packet flow information may comprise an identifier of a packet flow. The packet flow may be, for example, a bearer, a data radio bearer (DRB), a portion of a split bearer, and/or a QoS flow. The packet flow identifier may be a radio bearer identifier and/or a QoS flow identifier. The one or more radio resources may be physical layer radio resources.
Based on the packet flow information, the second base station may determine (e.g., identify) the one or more radio resources associated with the service. Based on the packet flow information, the second base station may determine (e.g., identify) the one or more radio resources to be allocated, reallocated, modified, and/or adjusted. Based on the one or more QoE measurement results received from the first base station, the second base station may determine the allocation, reallocation, modification, and/or adjustment of the one or more radio resources (e.g., the one or more radio resources associated with the service, the one or more radio resources identified based on the packet flow information). In accordance with the example embodiments, the network may leverage QoE reporting (e.g., RAN-visible QoE reporting) to improve provision of a service, even in a scenario wherein the base station that receives the report is not a sole provider of the service (e.g., a dual connectivity scenario).
Initially, BS1 may provide one or more services to the wireless device. BS1 may configure the wireless device to measure QoE (e.g., QoE measurement configuration). The QoE may be associated with a service of the one or more services. The service may be, for example, QoE-sensitive (e.g., video streaming, VR, etc.). The wireless device may generate one or more QoE measurement results based on the QoE measurement configuration.
BS1 may configure the wireless device to report QoE (e.g., QoE reporting configuration). BS1 may transmit, to the wireless device, an RRC reconfiguration message comprising the QoE reporting configuration. The wireless device may measure QoE of a service based on the QoE reporting configuration. The wireless device may determine a QoE report comprising one or more QoE measurement results based on measuring the QoE of the service. Based on the QoE reporting configuration, the wireless device may transmit, to BS1, a QoE report via an SRB. The QoE report may comprise one or more QoE measurement results. The QoE measurement results may comprise at least one value of RAN visible QoE metrics (as described previously). One or more of the one or more QoE measurement results may be associated with the service. One or more of the one or more QoE measurement results may comprise one or more PDU session IDs and/or RRC identifiers associated with the service. The SRB may be, for example, an SRB3, an SRB4, an SRB5 and/or the like. In an example, the QoE measurement results may comprise measurement report application layer container comprising application layer measurement results associated with the service.
BS1 may configure the wireless device and/or BS2 for dual connectivity as shown in
BS1 may send one or more QoE measurement results to BS2. The QoE measurement results may comprise at least one value of RAN visible QoE metrics (as described previously). The QoE measurement results may be associated with the service. The QoE measurement results may be determined, by BS1, based on a QoE report received from the wireless device and PDU session, DRB and/or QoS flow mapping information associated with the service of the wireless device. The PDU session, DRB and/or QoS flow mapping information may be from the dual connectivity configuration for the wireless device. The QoE measurement results sent to BS2 may comprise all of the QoE measurement results (e.g., every QoE measurement result in the QoE report) or a portion thereof (e.g., the QoE measurement results associated with the service).
Additionally or alternatively, BS1 may send to BS2 an indication (e.g., cause value) that one or more QoE measurement results are adequate/inadequate, satisfactory/unsatisfactory, etc. For example, BS1 may send a QoE measurement result (indicating a quality of experience) and/or an indication that the QoE measurement result falls below a threshold (indicating that the quality of experience is low).
BS1 may send packet flow information to BS2. The packet flow information may be determined, by BS1, based on a QoE report received from the wireless device and PDU session, DRB and/or QoS flow mapping information associated with the service of the wireless device. The packet flow information may indicate one or more packet flows associated with the service and/or the QoE measurement results. The packet flow information may comprise an identifier of a packet flow. The packet flow may be, for example, a bearer, a data radio bearer (DRB), a portion of a split bearer, and/or a QoS flow. The packet flow identifier may be a radio bearer identifier and/or a QoS flow identifier. The packet flow may also be a PDU session. The packet flow identifier may be a PDU session identifier. The packet flow information may not be included in one or more of the QoE measurement results, QoE report, etc. The packet flow information may be sent separately (e.g., in a separate message, or in the same message, but not within the one or more QoE measurement results, QoE report, etc.). The one or more radio resources may be physical layer radio resources.
The BS1 may send, to BS2, one or more messages comprising the one or more QoE measurement results and the packet flow information. The one or more messages may be, for example, a single message. The one or more messages may be, for example, a secondary node (SN) modification request message, SN addition request message, SN release request acknowledge message, SN release required message, QoE information transfer message, etc. The one or more messages may comprise at least one of an identifier (e.g., MeNB UE X2AP ID, SgNB UE X2AP ID) of the wireless device within eNB or gNB; an identifier (e.g., M-NG-RAN node UE XnAP ID, S-NG-RAN node UE XnAP ID) of the wireless device within master NG-RAN node or secondary NG-RAN node; and/or the like.
Based on the one or more QoE measurement results and the packet flow information, BS2 may configure (e.g., reconfigure, allocate, reallocate, modify, and/or adjust) one or more radio resources and/or radio resource parameters. For example, an application layer buffer level of a video stream service in a wireless device may be measured as low by the wireless device, which may be subsequently reported to BS2. BS2 may allocate more radio resources (e.g., more time/frequency and/or space resource, more carriers, more physical resource blocks (PRBs) to the wireless device so that the wireless downlink data rate is increased. Thus, the QoE on the video stream service is improved for the wireless device.
In an example, a user of a wireless device may be provided with a QoE-sensitive service (e.g., a video streaming application) in a dual connectivity scenario. BS1 may receive, from the wireless device, a QoE measurement result in a QoE report. The QoE measurement result may indicate that the user of the wireless device is experiencing a low quality of experience while using the service (e.g., choppy video). Based on the dual connectivity configuration (e.g., PDU session, DRB and/or QoS flow mapping information associated with the service of the wireless device) of BS1 and BS2, BS1 may know that BS2 is providing the service using radio resources associated with DRB1 (e.g., based on a dual connectivity configuration of BS1 and/or BS2). BS1 may send a message to BS2. The message may comprise the QoE measurement result (indicating poor QoE) and an identifier of DRB1. After receiving the message, BS2 may identify radio resources (e.g., physical layer radio resources) that are associated with DRB1. BS2 may modify one or more parameters of the radio resources to improve the QoE of the user. In an example, the QoE measurement result enables BS2 to recognize that the user is experiencing a low QoE. As a result, BS2 can modify the radio resource parameters and improve the user's QoE. In an example, the packet flow information enables BS2 to identify one or more particular radio resource parameters. As a result, BS2 can efficiently modify the radio resource parameters and improve the user's QoE.
In example embodiments, as shown in
In an example, the master base station of the wireless device may send, to the secondary base station of the wireless device, a cause value associated with the packet flow. The cause value may indicate that the sending of the request message (e.g., initiating an SN modification request) is due to a low QoE for the service. The secondary base station may adjust and/or enhance radio resource allocation for the packet flow as described in
In an example embodiment, as shown in
In an example, the secondary base station of the wireless device may send, to the master base station of the wireless device, a cause value associated with the packet flow. The required message may comprise the cause value associated with the packet flow. The cause value may indicate a low QoE for the service. The cause value may indicate that the sending the required message (e.g., initiating an SN modification) is due to low QoE for the service. The master base station may configure (reconfigure, allocate, reallocate, modify, adjust and/or enhance) radio resource allocation for the packet flow as described in
In an example embodiment, as shown in
In an example, the master base station of the wireless device may send, to the secondary base station of the wireless device, the request message comprising at least one of: available RAN visible QoE metrics (as descripted above, e.g., buffer level, playout delay for media startup); a QoE measurement type (e.g., signaling based, management based); QoE measurement status (e.g., ongoing, paused); MDT alignment information indicating that signaling-based MDT measurements with which alignment is required, wherein it may comprise NG-RAN trace identifier; a cause value indicating a low QoE for the service, which may be associated with the packet flow; and or the like. The cause value may indicate that the sending the request message (e.g., initiating an SN modification request) is due to low QoE for the service.
In an example, the secondary base station may select/determine RAN visible QoE metrics based on the received available RAN visible QoE metrics. The secondary base station may also adjust and/or enhance radio resource allocation for the packer flow, as described above, in
In an example embodiment, as shown in
In an example, the secondary base station may determine and/or include the required information and send it to the master base station via a release request acknowledge message (e.g., SN release request acknowledge message), wherein the information comprising at least one of: available RAN visible QoE metrics (as descripted above, e.g., buffer level, playout delay for media startup); a QoE measurement type (e.g., signaling based, management based); QoE measurement status (e.g., ongoing, paused); MDT alignment information indicating that signaling-based MDT measurements with which alignment is required, wherein it may comprise NG-RAN trace identifier; and or the like. Based on the received information, the master base station may take it into account. For example, the master base station may apply at least one of: the same or partial of the received RAN visible QoE metrics (as described above, e.g., buffer level, playout delay for media startup); a QoE measurement type (e.g., signaling based, management based); keep to perform QoE measurement (e.g., ongoing) or pause the QoE measurement; apply the MDT alignment information (e.g., NG-RAN trace identifier) with QoE measurement associated with the service. The SN release request acknowledge message may indicate that the secondary base station accept the release request and include the required information of the master base station.
In an example, the master base station may send to the wireless device a RRC message indicating the QoE measurement configuration/information determined as above. The wireless device may apply the configuration and may send a response message confirming the RRC connection reconfiguration complete to the master base station, which may forward the reconfiguration complete message to the secondary base station.
In an example embodiment, as shown in
For example, based on the received information, the master base station may take it into account. For example, the master base station may apply at least one of: the same or partial of the received RAN visible QoE metrics (as descripted above, e.g., buffer level, playout delay for media startup); a QoE measurement type (e.g., signaling based, management based); keep to perform QoE measurement (e.g., ongoing) or pause the QoE measurement; apply the MDT alignment information (e.g., NG-RAN trace identifier) with QoE measurement associated with the service. In response of the actions above, the master base station may send a SN release request acknowledge message, which indicates that the master base station adjusted and/or enhanced radio resource allocation for the packet flow, based on the SN release required message comprising the cause value. In an example, the master base station may send to the wireless device a RRC message indicating the QoE measurement configuration/information determined as above. The wireless device may apply the configuration and may send a response message confirming the RRC connection reconfiguration complete to the master base station.
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In an example, the packet flow associated with the QoE may be established via the second base station. The secondary node configuration may comprise a secondary node modification. In an example, the packet flow associated with the QoE may be established via the first base station. The secondary node configuration may comprise at least one of: a secondary node addition; a secondary node modification; and/or the like.
In an example, the secondary node addition and/or the secondary node modification comprises at least one of: an identifier (e.g., MeNB UE X2AP ID, SgNB UE X2AP ID) of the wireless device within eNB or gNB; an identifier (e.g., M-NG-RAN node UE XnAP ID, S-NG-RAN node UE XnAP ID) of the wireless device within master NG-RAN node or secondary NG-RAN node. In an example, the packet flow may comprise at least one of: a quality-of-service (QOS) flow; a bearer; a logical channel. The measurement report may comprise at least one of: a PDU session identifier; a RRC identifier; and/or the like.
In an example, the wireless device may be associated with one or more protocol data unit (PDU) sessions; one or more data radio bearers (DRB); and/or one or more quality of service (QOS) flows. The measurement report of the QoE for the service may comprise at least one value of RAN visible QoE metrics comprising: buffer level; playout delay for media setup; an application layer buffer level; an initial playout delay; a round-trip time; a jitter duration; a correction duration; an average throughput; a device information; rendered viewports; a codec information; representation switch events; play list (e.g., a list of playback periods); a media presentation description (MPD) information; an interactivity summary; an interactivity event list; and/or the like.
In an example, the measurement result of the QoE for the service may comprise at least one value of RAN visible QoE metrics comprising: buffer level; playout delay for media setup; an application layer buffer level; an initial playout delay; a round-trip time; a jitter duration; a correction duration; an average throughput; a device information; rendered viewports; a codec information; representation switch events; play list (e.g., a list of playback periods); a media presentation description (MPD) information; an interactivity summary; an interactivity event list; and/or the like.
In an example, the first base station may determine the QoE measurement result and/or the packet flow information of the packet flow associated with the QoE for sending to the second base station based on the PDU session, DRB and QoS flow mapping information associated with the service of the wireless device.
In an example, The first base station may send to the wireless device QoE measurement configuration information comprising at least one of: a container for application layer measurement configuration; a measurement configuration application layer identifier; a list of cell identifiers for QMC; a list of tracking area identities (TAIs) for QMC; a list of public land mobile networks (PLMNs) for QMC; a service type to perform QMC for the wireless device; a QoE reference; a measurement collection entity IP address; a list of single network slice selection assistance information (S-NSSAls); and/or the like. In an example, the service type may comprise at least one of: a streaming service; a multimedia telephony service for IMS (MTSI) service; a virtual reality (VR) service; an extended reality (XR) service; a multimedia broadcast and multicast service (MBMS); a multicast broadcast service (MBS); and/or the like.
In an example, the application layer measurement configuration parameters may comprise at least one of: an average throughput of streaming services and/or VR services; an initial playout delay of streaming services and/or VR services; a buffer level status of streaming services and/or VR services; a list of playback periods (play list) of streaming services and/or VR services; a successive loss of real-time transport protocol packets of MTSI services; a frame rate of MTSI services; a jitter duration of MTSI services; a sync loss duration of MTSI services; a round-trip time of MTSI services; an average codec bitrate of MTSI services; a call setup time for MTSI service of MTSI services; a comparable quality viewport switching latency of VR services; a list of viewports that have been rendered during the media presentation of VR services; and/or the like.
In an example, the radio resource control message may comprises at least one of: an SRB3; an SRB4; an SRB5 (e.g., combination of SRB3 and SRB4); and/or the like. The measurement report may comprise the measurement report application layer message comprising at least one of: a measurement configuration application layer identifier; a measurement report application layer container; and/or the like.
In an example, the measurement report application layer container may comprise application layer measurement results for at least one of: an average throughput of streaming services and/or VR services; an initial playout delay of streaming services and/or VR services; a buffer level status of streaming services and/or VR services; a list of playback periods (play list) of streaming services and/or VR services; a successive loss of real-time transport protocol packets of MTSI services; a frame rate of MTSI services; a jitter duration of MTSI services; a sync loss duration of MTSI services; a round-trip time of MTSI services; an average codec bitrate of MTSI services; a call setup time for MTSI service of MTSI services; a comparable quality viewport switching latency of VR services; a list of viewports that have been rendered during the media presentation of VR services; and/or the like.
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This application is a continuation of International Application No. PCT/US2023/026605, filed Jun. 29, 2023, which claims the benefit of U.S. Provisional Application No. 63/356,811, filed Jun. 29, 2022, all of which are hereby incorporated by reference in their entireties.
Number | Date | Country | |
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63356811 | Jun 2022 | US |
Number | Date | Country | |
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Parent | PCT/US2023/026605 | Jun 2023 | WO |
Child | 18760863 | US |