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 effect 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 road side 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, WiFi 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 a 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 11311 and/or the Msg 31313. Based on the one or more RACH parameters, the UE may determine a reception timing and a downlink channel for receiving the Msg 21312 and the Msg 41314.
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 11311. 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 11311 and/or Msg 31313. 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 11311 and the Msg 31313; 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 11311 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 31313. 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 31313. 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 11311 based on the association. The Msg 11311 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 21312 received by the UE may include an RAR. In some scenarios, the Msg 21312 may include multiple RARs corresponding to multiple UEs. The Msg 21312 may be received after or in response to the transmitting of the Msg 11311. The Msg 21312 may be scheduled on the DL-SCH and indicated on a PDCCH using a random access RNTI (RA-RNTI). The Msg 21312 may indicate that the Msg 11311 was received by the base station. The Msg 21312 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 31313, 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 21312. 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:
The Msg 41314 may be received after or in response to the transmitting of the Msg 31313. If a C-RNTI was included in the Msg 31313, 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 31313 (e.g., if the UE is in an RRC_IDLE state or not otherwise connected to the base station), Msg 41314 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 31313, 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 11311 and/or the Msg 31313) may remain on the selected carrier. The UE may switch an uplink carrier during the random access procedure (e.g., between the Msg 11311 and the Msg 31313) in one or more cases. For example, the UE may determine and/or switch an uplink carrier for the Msg 11311 and/or the Msg 31313 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 31313 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 31313 illustrated in
Depending on the purpose and/or content of a DCI, the base station may transmit the DCIs with one or more DCI formats. For example, DCI format 0_0 may be used for scheduling of PUSCH in a cell. DCI format 0_0 may be a fallback DCI format (e.g., with compact DCI payloads). DCI format 0_1 may be used for scheduling of PUSCH in a cell (e.g., with more DCI payloads than DCI format 0_0). DCI format 1_0 may be used for scheduling of PDSCH in a cell. DCI format 1_0 may be a fallback DCI format (e.g., with compact DCI payloads). DCI format 1_1 may be used for scheduling of PDSCH in a cell (e.g., with more DCI payloads than DCI format 1_0). DCI format 2_0 may be used for providing a slot format indication to a group of UEs. DCI format 2_1 may be used for notifying a group of UEs of a physical resource block and/or OFDM symbol where the UE may assume no transmission is intended to the UE. DCI format 2_2 may be used for transmission of a transmit power control (TPC) command for PUCCH or PUSCH. DCI format 2_3 may be used for transmission of a group of TPC commands for SRS transmissions by one or more UEs. DCI format(s) for new functions may be defined in future releases. DCI formats may have different DCI sizes, or may share the same DCI size.
After scrambling a DCI with a RNTI, the base station may process the DCI with channel coding (e.g., polar coding), rate matching, scrambling and/or QPSK modulation. A base station may map the coded and modulated DCI on resource elements used and/or configured for a PDCCH. Based on a payload size of the DCI and/or a coverage of the base station, the base station may transmit the DCI via a PDCCH occupying a number of contiguous control channel elements (CCEs). The number of the contiguous CCEs (referred to as aggregation level) may be 1, 2, 4, 8, 16, and/or any other suitable number. A CCE may comprise a number (e.g., 6) of resource-element groups (REGs). A REG may comprise a resource block in an OFDM symbol. The mapping of the coded and modulated DCI on the resource elements may be based on mapping of CCEs and REGs (e.g., CCE-to-REG mapping).
The base station may transmit, to the UE, RRC messages comprising configuration parameters of one or more CORESETs and one or more search space sets. The configuration parameters may indicate an association between a search space set and a CORESET. A search space set may comprise a set of PDCCH candidates formed by CCEs at a given aggregation level. The configuration parameters may indicate: a number of PDCCH candidates to be monitored per aggregation level; a PDCCH monitoring periodicity and a PDCCH monitoring pattern; one or more DCI formats to be monitored by the UE; and/or whether a search space set is a common search space set or a UE-specific search space set. A set of CCEs in the common search space set may be predefined and known to the UE. A set of CCEs in the UE-specific search space set may be configured based on the UE's identity (e.g., C-RNTI).
As shown in
The UE may transmit uplink control signaling (e.g., uplink control information (UCI) to a base station. The uplink control signaling may comprise hybrid automatic repeat request (HARQ) acknowledgements for received DL-SCH transport blocks. The UE may transmit the HARQ acknowledgements after receiving a DL-SCH transport block. Uplink control signaling may comprise channel state information (CSI) indicating channel quality of a physical downlink channel. The UE may transmit the CSI to the base station. The base station, based on the received CSI, may determine transmission format parameters (e.g., comprising multi-antenna and beamforming schemes) for a downlink transmission. Uplink control signaling may comprise scheduling requests (SR). The UE may transmit an SR indicating that uplink data is available for transmission to the base station. The UE may transmit a UCI (e.g., HARQ acknowledgements (HARQ-ACK), CSI report, SR, and the like) via a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH). The UE may transmit the uplink control signaling via a PUCCH using one of several PUCCH formats.
There may be five PUCCH formats and the UE may determine a PUCCH format based on a size of the UCI (e.g., a number of uplink symbols of UCI transmission and a number of UCI bits). PUCCH format 0 may have a length of one or two OFDM symbols and may include two or fewer bits. The UE may transmit UCI in a PUCCH resource using PUCCH format 0 if the transmission is over one or two symbols and the number of HARQ-ACK information bits with positive or negative SR (HARQ-ACK/SR bits) is one or two. PUCCH format 1 may occupy a number between four and fourteen OFDM symbols and may include two or fewer bits. The UE may use PUCCH format 1 if the transmission is four or more symbols and the number of HARQ-ACK/SR bits is one or two. PUCCH format 2 may occupy one or two OFDM symbols and may include more than two bits. The UE may use PUCCH format 2 if the transmission is over one or two symbols and the number of UCI bits is two or more. PUCCH format 3 may occupy a number between four and fourteen OFDM symbols and may include more than two bits. The UE may use PUCCH format 3 if the transmission is four or more symbols, the number of UCI bits is two or more and PUCCH resource does not include an orthogonal cover code. PUCCH format 4 may occupy a number between four and fourteen OFDM symbols and may include more than two bits. The UE may use PUCCH format 4 if the transmission is four or more symbols, the number of UCI bits is two or more and the PUCCH resource includes an orthogonal cover code.
The base station may transmit configuration parameters to the UE for a plurality of PUCCH resource sets using, for example, an RRC message. The plurality of PUCCH resource sets (e.g., up to four sets) may be configured on an uplink BWP of a cell. A PUCCH resource set may be configured with a PUCCH resource set index, a plurality of PUCCH resources with a PUCCH resource being identified by a PUCCH resource identifier (e.g., pucch-Resourceid), and/or a number (e.g. a maximum number) of UCI information bits the UE may transmit using one of the plurality of PUCCH resources in the PUCCH resource set. When configured with a plurality of PUCCH resource sets, the UE may select one of the plurality of PUCCH resource sets based on a total bit length of the UCI information bits (e.g., HARQ-ACK, SR, and/or CSI). If the total bit length of UCI information bits is two or fewer, the UE may select a first PUCCH resource set having a PUCCH resource set index equal to “0”. If the total bit length of UCI information bits is greater than two and less than or equal to a first configured value, the UE may select a second PUCCH resource set having a PUCCH resource set index equal to “1”. If the total bit length of UCI information bits is greater than the first configured value and less than or equal to a second configured value, the UE may select a third PUCCH resource set having a PUCCH resource set index equal to “2”. If the total bit length of UCI information bits is greater than the second configured value and less than or equal to a third value (e.g., 1406), the UE may select a fourth PUCCH resource set having a PUCCH resource set index equal to “3”.
After determining a PUCCH resource set from a plurality of PUCCH resource sets, the UE may determine a PUCCH resource from the PUCCH resource set for UCI (HARQ-ACK, CSI, and/or SR) transmission. The UE may determine the PUCCH resource based on a PUCCH resource indicator in a DCI (e.g., with a DCI format 1_0 or DCI for 1_1) received on a PDCCH. A three-bit PUCCH resource indicator in the DCI may indicate one of eight PUCCH resources in the PUCCH resource set. Based on the PUCCH resource indicator, the UE may transmit the UCI (HARQ-ACK, CSI and/or SR) using a PUCCH resource indicated by the PUCCH resource indicator in the DCI.
The base station 1504 may connect the wireless device 1502 to a core network (not shown) through radio communications over the air interface (or radio interface) 1506. The communication direction from the base station 1504 to the wireless device 1502 over the air interface 1506 is known as the downlink, and the communication direction from the wireless device 1502 to the base station 1504 over the air interface is known as the uplink. Downlink transmissions may be separated from uplink transmissions using FDD, TDD, and/or some combination of the two duplexing techniques.
In the downlink, data to be sent to the wireless device 1502 from the base station 1504 may be provided to the processing system 1508 of the base station 1504. The data may be provided to the processing system 1508 by, for example, a core network. In the uplink, data to be sent to the base station 1504 from the wireless device 1502 may be provided to the processing system 1518 of the wireless device 1502. The processing system 1508 and the processing system 1518 may implement layer 3 and layer 2 OSI functionality to process the data for transmission. Layer 2 may include an SDAP layer, a PDCP layer, an RLC layer, and a MAC layer, for example, with respect to
After being processed by processing system 1508, the data to be sent to the wireless device 1502 may be provided to a transmission processing system 1510 of base station 1504. Similarly, after being processed by the processing system 1518, the data to be sent to base station 1504 may be provided to a transmission processing system 1520 of the wireless device 1502. The transmission processing system 1510 and the transmission processing system 1520 may implement layer 1 OSI functionality. Layer 1 may include a PHY layer with respect to
At the base station 1504, a reception processing system 1512 may receive the uplink transmission from the wireless device 1502. At the wireless device 1502, a reception processing system 1522 may receive the downlink transmission from base station 1504. The reception processing system 1512 and the reception processing system 1522 may implement layer 1 OSI functionality. Layer 1 may include a PHY layer with respect to
As shown in
The processing system 1508 and the processing system 1518 may be associated with a memory 1514 and a memory 1524, respectively. Memory 1514 and memory 1524 (e.g., one or more non-transitory computer readable mediums) may store computer program instructions or code that may be executed by the processing system 1508 and/or the processing system 1518 to carry out one or more of the functionalities discussed in the present application. Although not shown in
The processing system 1508 and/or the processing system 1518 may comprise one or more controllers and/or one or more processors. The one or more controllers and/or one or more processors may comprise, for example, a general-purpose processor, a digital signal processor (DSP), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) and/or other programmable logic device, discrete gate and/or transistor logic, discrete hardware components, an on-board unit, or any combination thereof. The processing system 1508 and/or the processing system 1518 may perform at least one of signal coding/processing, data processing, power control, input/output processing, and/or any other functionality that may enable the wireless device 1502 and the base station 1504 to operate in a wireless environment.
The processing system 1508 and/or the processing system 1518 may be connected to one or more peripherals 1516 and one or more peripherals 1526, respectively. The one or more peripherals 1516 and the one or more peripherals 1526 may include software and/or hardware that provide features and/or functionalities, for example, a speaker, a microphone, a keypad, a display, a touchpad, a power source, a satellite transceiver, a universal serial bus (USB) port, a hands-free headset, a frequency modulated (FM) radio unit, a media player, an Internet browser, an electronic control unit (e.g., for a motor vehicle), and/or one or more sensors (e.g., an accelerometer, a gyroscope, a temperature sensor, a radar sensor, a lidar sensor, an ultrasonic sensor, a light sensor, a camera, and/or the like). The processing system 1508 and/or the processing system 1518 may receive user input data from and/or provide user output data to the one or more peripherals 1516 and/or the one or more peripherals 1526. The processing system 1518 in the wireless device 1502 may receive power from a power source and/or may be configured to distribute the power to the other components in the wireless device 1502. The power source may comprise one or more sources of power, for example, a battery, a solar cell, a fuel cell, or any combination thereof. The processing system 1508 and/or the processing system 1518 may be connected to a GPS chipset 1517 and a GPS chipset 1527, respectively. The GPS chipset 1517 and the GPS chipset 1527 may be configured to provide geographic location information of the wireless device 1502 and the base station 1504, respectively.
A wireless device may receive from a base station one or more messages (e.g. RRC messages) comprising configuration parameters of a plurality of cells (e.g. primary cell, secondary cell). The wireless device may communicate with at least one base station (e.g. two or more base stations in dual-connectivity) via the plurality of cells. The one or more messages (e.g. as a part of the configuration parameters) may comprise parameters of physical, MAC, RLC, PCDP, SDAP, RRC layers for configuring the wireless device. For example, the configuration parameters may comprise parameters for configuring physical and MAC layer channels, bearers, etc. For example, the configuration parameters may comprise parameters indicating values of timers for physical, MAC, RLC, PCDP, SDAP, RRC layers, and/or communication channels.
A timer may begin running once it is started and continue running until it is stopped or until it expires. A timer may be started if it is not running or restarted if it is running. A timer may be associated with a value (e.g. the timer may be started or restarted from a value or may be started from zero and expire once it reaches the value). The duration of a timer may not be updated until the timer is stopped or expires (e.g., due to BWP switching). A timer may be used to measure a time period/window for a process. When the specification refers to an implementation and procedure related to one or more timers, it will be understood that there are multiple ways to implement the one or more timers. For example, it will be understood that one or more of the multiple ways to implement a timer may be used to measure a time period/window for the procedure. For example, a random access response window timer may be used for measuring a window of time for receiving a random access response. In an example, instead of starting and expiry of a random access response window timer, the time difference between two time stamps may be used. When a timer is restarted, a process for measurement of time window may be restarted. Other example implementations may be provided to restart a measurement of a time window.
A base station may transmit one or more MAC PDUs to a wireless device. In an example, a MAC PDU may be a bit string that is byte aligned (e.g., aligned to a multiple of eight bits) in length. In an example, bit strings may be represented by tables in which the most significant bit is the leftmost bit of the first line of the table, and the least significant bit is the rightmost bit on the last line of the table. More generally, the bit string may be read from left to right and then in the reading order of the lines. In an example, the bit order of a parameter field within a MAC PDU is represented with the first and most significant bit in the leftmost bit and the last and least significant bit in the rightmost bit.
In an example, a MAC SDU may be a bit string that is byte aligned (e.g., aligned to a multiple of eight bits) in length. In an example, a MAC SDU may be included in a MAC PDU from the first bit onward. A MAC CE may be a bit string that is byte aligned (e.g., aligned to a multiple of eight bits) in length. A MAC subheader may be a bit string that is byte aligned (e.g., aligned to a multiple of eight bits) in length. In an example, a MAC subheader may be placed immediately in front of a corresponding MAC SDU, MAC CE, or padding. A MAC entity may ignore a value of reserved bits in a DL MAC PDU.
In an example, a MAC PDU may comprise one or more MAC subPDUs. A MAC subPDU of the one or more MAC subPDUs may comprise: a MAC subheader only (including padding); a MAC subheader and a MAC SDU; a MAC subheader and a MAC CE; a MAC subheader and padding, or a combination thereof. The MAC SDU may be of variable size. A MAC subheader may correspond to a MAC SDU, a MAC CE, or padding.
In an example, when a MAC subheader corresponds to a MAC SDU, a variable-sized MAC CE, or padding, the MAC subheader may comprise: an R field with a one bit length; an F field with a one-bit length; an LCID field with a multi-bit length; an L field with a multi-bit length, or a combination thereof.
In an example, a MAC entity of a base station may transmit one or more MAC CEs to a MAC entity of a wireless device.
In an example, the MAC entity of the wireless device may transmit to the MAC entity of the base station one or more MAC CEs.
In carrier aggregation (CA), two or more component carriers (CCs) may be aggregated. A wireless device may simultaneously receive or transmit on one or more CCs, depending on capabilities of the wireless device, using the technique of CA. In an embodiment, a wireless device may support CA for contiguous CCs and/or for non-contiguous CCs. CCs may be organized into cells. For example, CCs may be organized into one primary cell (PCell) and one or more secondary cells (SCells). When configured with CA, a wireless device may have one RRC connection with a network. During an RRC connection establishment/re-establishment/handover, a cell providing NAS mobility information may be a serving cell. During an RRC connection re-establishment/handover procedure, a cell providing a security input may be a serving cell. In an example, the serving cell may denote a PCell. In an example, a base station may transmit, to a wireless device, one or more messages comprising configuration parameters of a plurality of one or more SCells, depending on capabilities of the wireless device.
When configured with CA, a base station and/or a wireless device may employ an activation/deactivation mechanism of an SCell to improve battery or power consumption of the wireless device. When a wireless device is configured with one or more SCells, a base station may activate or deactivate at least one of the one or more SCells. Upon configuration of an SCell, the SCell may be deactivated unless an SCell state associated with the SCell is set to “activated” or “dormant”.
A wireless device may activate/deactivate an SCell in response to receiving an SCell Activation/Deactivation MAC CE. In an example, a base station may transmit, to a wireless device, one or more messages comprising an SCell timer (e.g., sCellDeactivation Timer). In an example, a wireless device may deactivate an SCell in response to an expiry of the SCell timer.
When a wireless device receives an SCell Activation/Deactivation MAC CE activating an SCell, the wireless device may activate the SCell. In response to the activating the SCell, the wireless device may perform operations comprising SRS transmissions on the SCell; CQI/PMI/RI/CRI reporting for the SCell; PDCCH monitoring on the SCell; PDCCH monitoring for the SCell; and/or PUCCH transmissions on the SCell. In response to the activating the SCell, the wireless device may start or restart a first SCell timer (e.g., sCellDeactivation Timer) associated with the SCell. The wireless device may start or restart the first SCell timer in the slot when the SCell Activation/Deactivation MAC CE activating the SCell has been received. In an example, in response to the activating the SCell, the wireless device may (re-) initialize one or more suspended configured uplink grants of a configured grant Type 1 associated with the SCell according to a stored configuration. In an example, in response to the activating the SCell, the wireless device may trigger PHR.
When a wireless device receives an SCell Activation/Deactivation MAC CE deactivating an activated SCell, the wireless device may deactivate the activated SCell. In an example, when a first SCell timer (e.g., sCellDeactivation Timer) associated with an activated SCell expires, the wireless device may deactivate the activated SCell. In response to the deactivating the activated SCell, the wireless device may stop the first SCell timer associated with the activated SCell. In an example, in response to the deactivating the activated SCell, the wireless device may clear one or more configured downlink assignments and/or one or more configured uplink grants of a configured uplink grant Type 2 associated with the activated SCell. In an example, in response to the deactivating the activated SCell, the wireless device may: suspend one or more configured uplink grants of a configured uplink grant Type 1 associated with the activated SCell; and/or flush HARQ buffers associated with the activated SCell.
When an SCell is deactivated, a wireless device may not perform operations comprising: transmitting SRS on the SCell; reporting CQI/PMI/RI/CRI for the SCell; transmitting on UL-SCH on the SCell; transmitting on RACH on the SCell; monitoring at least one first PDCCH on the SCell; monitoring at least one second PDCCH for the SCell; and/or transmitting a PUCCH on the SCell. When at least one first PDCCH on an activated SCell indicates an uplink grant or a downlink assignment, a wireless device may restart a first SCell timer (e.g., sCellDeactivation Timer) associated with the activated SCell. In an example, when at least one second PDCCH on a serving cell (e.g., a PCell or an SCell configured with PUCCH, i.e., PUCCH SCell) scheduling the activated SCell indicates an uplink grant or a downlink assignment for the activated SCell, a wireless device may restart the first SCell timer (e.g., sCellDeactivation Timer) associated with the activated SCell. In an example, when an SCell is deactivated, if there is an ongoing random access procedure on the SCell, a wireless device may abort the ongoing random access procedure on the SCell.
In
A base station may configure a wireless device with uplink (UL) bandwidth parts (BWPs) and downlink (DL) BWPs to enable bandwidth adaptation (BA) on a PCell. If carrier aggregation is configured, the base station may further configure the wireless device with at least DL BWP(s) (i.e., there may be no UL BWPs in the UL) to enable BA on an SCell. For the PCell, an initial active BWP may be a first BWP used for initial access. For the SCell, a first active BWP may be a second BWP configured for the wireless device to operate on the SCell upon the SCell being activated. In paired spectrum (e.g., FDD), a base station and/or a wireless device may independently switch a DL BWP and an UL BWP. In unpaired spectrum (e.g., TDD), a base station and/or a wireless device may simultaneously switch a DL BWP and an UL BWP.
In an example, a base station and/or a wireless device may switch a BWP between configured BWPs by means of a DCI or a BWP inactivity timer. When the BWP inactivity timer is configured for a serving cell, the base station and/or the wireless device may switch an active BWP to a default BWP in response to an expiry of the BWP inactivity timer associated with the serving cell. The default BWP may be configured by the network. In an example, for FDD systems, when configured with BA, one UL BWP for each uplink carrier and one DL BWP may be active at a time in an active serving cell. In an example, for TDD systems, one DL/UL BWP pair may be active at a time in an active serving cell. Operating on the one UL BWP and the one DL BWP (or the one DL/UL pair) may improve wireless device battery consumption. BWPs other than the one active UL BWP and the one active DL BWP that the wireless device may work on may be deactivated. On deactivated BWPs, the wireless device may: not monitor PDCCH; and/or not transmit on PUCCH, PRACH, and UL-SCH.
In an example, a serving cell may be configured with at most a first number (e.g., four) of BWPs. In an example, for an activated serving cell, there may be one active BWP at any point in time. In an example, a BWP switching for a serving cell may be used to activate an inactive BWP and deactivate an active BWP at a time. In an example, the BWP switching may be controlled by a PDCCH indicating a downlink assignment or an uplink grant. In an example, the BWP switching may be controlled by a BWP inactivity timer (e.g., bwp-Inactivity Timer). In an example, the BWP switching may be controlled by a MAC entity in response to initiating a Random Access procedure. Upon addition of an SpCell or activation of an SCell, one BWP may be initially active without receiving a PDCCH indicating a downlink assignment or an uplink grant. The active BWP for a serving cell may be indicated by RRC and/or PDCCH. In an example, for unpaired spectrum, a DL BWP may be paired with a UL BWP, and BWP switching may be common for both UL and DL.
In an example, the wireless device may start (or restart) a BWP inactivity timer (e.g., bwp-Inactivity Timer) at an mth slot in response to receiving a DCI indicating DL assignment on BWP 1. The wireless device may switch back to the default BWP (e.g., BWP 0) as an active BWP when the BWP inactivity timer expires, at sth slot. The wireless device may deactivate the cell and/or stop the BWP inactivity timer when the sCellDeactivation Timer expires (e.g., if the cell is a SCell). In response to the cell being a PCell, the wireless device may not deactivate the cell and may not apply the sCellDeactivation Timer on the PCell.
In an example, a MAC entity may apply normal operations on an active BWP for an activated serving cell configured with a BWP comprising: transmitting on UL-SCH; transmitting on RACH; monitoring a PDCCH; transmitting PUCCH; receiving DL-SCH; and/or (re-) initializing any suspended configured uplink grants of configured grant Type 1 according to a stored configuration, if any.
In an example, on an inactive BWP for each activated serving cell configured with a BWP, a MAC entity may: not transmit on UL-SCH; not transmit on RACH; not monitor a PDCCH; not transmit PUCCH; not transmit SRS, not receive DL-SCH; clear any configured downlink assignment and configured uplink grant of configured grant Type 2; and/or suspend any configured uplink grant of configured Type 1.
In an example, if a MAC entity receives a PDCCH for a BWP switching of a serving cell while a Random Access procedure associated with this serving cell is not ongoing, a wireless device may perform the BWP switching to a BWP indicated by the PDCCH. In an example, if a bandwidth part indicator field is configured in DCI format 1_1, the bandwidth part indicator field value may indicate the active DL BWP, from the configured DL BWP set, for DL receptions. In an example, if a bandwidth part indicator field is configured in DCI format 0_1, the bandwidth part indicator field value may indicate the active UL BWP, from the configured UL BWP set, for UL transmissions.
In an example, for a primary cell, a wireless device may be provided by a higher layer parameter Default-DL-BWP a default DL BWP among the configured DL BWPs. If a wireless device is not provided a default DL BWP by the higher layer parameter Default-DL-BWP, the default DL BWP is the initial active DL BWP. In an example, a wireless device may be provided by higher layer parameter bwp-InactivityTimer, a timer value for the primary cell. If configured, the wireless device may increment the timer, if running, every interval of 1 millisecond for frequency range 1 or every 0.5 milliseconds for frequency range 2 if the wireless device may not detect a DCI format 1_1 for paired spectrum operation or if the wireless device may not detect a DCI format 1_1 or DCI format 0_1 for unpaired spectrum operation during the interval.
In an example, if a wireless device is configured for a secondary cell with higher layer parameter Default-DL-BWP indicating a default DL BWP among the configured DL BWPs and the wireless device is configured with higher layer parameter bwp-Inactivity Timer indicating a timer value, the wireless device procedures on the secondary cell may be same as on the primary cell using the timer value for the secondary cell and the default DL BWP for the secondary cell.
In an example, if a wireless device is configured by higher layer parameter Active-BWP-DL-SCell a first active DL BWP and by higher layer parameter Active-BWP-UL-SCell a first active UL BWP on a secondary cell or carrier, the wireless device may use the indicated DL BWP and the indicated UL BWP on the secondary cell as the respective first active DL BWP and first active UL BWP on the secondary cell or carrier.
In an example, a set of PDCCH candidates for a wireless device to monitor is defined in terms of PDCCH search space sets. A search space set comprises a CSS set or a USS set. A wireless device monitors PDCCH candidates in one or more of the following search spaces sets: a Type0-PDCCH CSS set configured by pdcch-ConfigSIB1 in MIB or by searchSpaceSIB1 in PDCCH-ConfigCommon or by searchSpaceZero in PDCCH-ConfigCommon for a DCI format with CRC scrambled by a SI-RNTI on the primary cell of the MCG, a Type0A-PDCCH CSS set configured by search SpaceOtherSystemInformation in PDCCH-ConfigCommon for a DCI format with CRC scrambled by a SI-RNTI on the primary cell of the MCG, a Type1-PDCCH CSS set configured by ra-Search Space in PDCCH-ConfigCommon for a DCI format with CRC scrambled by a RA-RNTI, a MsgB-RNTI, or a TC-RNTI on the primary cell, a Type2-PDCCH CSS set configured by pagingSearchSpace in PDCCH-ConfigCommon for a DCI format with CRC scrambled by a P-RNTI on the primary cell of the MCG, a Type3-PDCCH CSS set configured by SearchSpace in PDCCH-Config with searchSpace Type=common for DCI formats with CRC scrambled by INT-RNTI, SFI-RNTI, TPC-PUSCH-RNTI, TPC-PUCCH-RNTI, TPC-SRS-RNTI, CI-RNTI, or PS-RNTI and, only for the primary cell, C-RNTI, MCS-C-RNTI, or CS-RNTI(s), and a USS set configured by SearchSpace in PDCCH-Config with searchSpace Type=ue-Specific for DCI formats with CRC scrambled by C-RNTI, MCS-C-RNTI, SP-CSI-RNTI, CS-RNTI(s), SL-RNTI, SL-CS-RNTI, or SL-L-CS-RNTI.
In an example, a wireless device determines a PDCCH monitoring occasion on an active DL BWP based on one or more PDCCH configuration parameters (e.g., based on example embodiment of
In an example, a wireless device decides, for a search space set s associated with CORESET p, CCE indexes for aggregation level L corresponding to PDCCH candidate ms,n
where, Yp,n
In an example, a wireless device may monitor a set of PDCCH candidates according to configuration parameters of a search space set comprising a plurality of search spaces (SSs). The wireless device may monitor a set of PDCCH candidates in one or more CORESETs for detecting one or more DCIs. A CORESET may be configured based on example embodiment of
In an example, a pdcch-ConfigSIB1 may comprise a first parameter (e.g., controlResourceSetZero) indicating a common ControlResourceSet (CORESET) with ID #0 (e.g., CORESET #0) of an initial BWP of the cell. controlResourceSetZero may be an integer between 0 and 15. Each integer between 0 and 15 may identify a configuration of CORESET #0.
In an example, a pdcch-ConfigSIB1 may comprise a second parameter (e.g., searchSpaceZero) indicating a common search space with ID #0 (e.g., SS #0) of the initial BWP of the cell. search SpaceZero may be an integer between 0 and 15. Each integer between 0 and 15 may identify a configuration of SS #0.
In an example, based on receiving a MIB, a wireless device may monitor PDCCH via SS #0 of CORESET #0 for receiving a DCI scheduling a system information block 1 (SIB1). A SIB1 message may be implemented based on example embodiment of
In an example, a DownlinkConfigCommonSIB IE may comprise parameters of an initial downlink BWP (intialDownlinkBWP IE) of the serving cell (e.g., SpCell). The parameters of the initial downlink BWP may be comprised in a BWP-DownlinkCommon IE (as shown in
In an example, the DownlinkConfigCommonSIB IE may comprise parameters of a paging channel configuration. The parameters may comprise a paging cycle value (T, by defaultPagingCycle IE), a parameter (nAndPagingFrameOffset IE) indicating total number N) of paging frames (PFs) and paging frame offset (PF_offset) in a paging DRX cycle, a number (Ns) for total paging occasions (POs) per PF, a first PDCCH monitoring occasion indication parameter (firstPDCCH-MonitoringOccasionofPO IE) indicating a first PDCCH monitoring occasion for paging of each PO of a PF. The wireless device, based on parameters of a PCCH configuration, may monitor PDCCH for receiving paging message, e.g., based on example embodiments of
In an example, the parameter first-PDCCH-MonitoringOccasionOfPO may be signaled in SIB1 for paging in initial DL BWP. For paging in a DL BWP other than the initial DL BWP, the parameter first-PDCCH-MonitoringOccasionOfPO may be signaled in the corresponding BWP configuration.
As shown in
In an example, a wireless device, in RRC_IDLE or RRC_INACTIVE state, may periodically monitor paging occasions (POs) for receiving paging message for the wireless device. Before monitoring the POs, the wireless device, in RRC_IDLE or RRC_INACTIVE state, may wake up at a time before each PO for preparation and/or turn all components in preparation of data reception (warm up). The gap between the waking up and the PO may be long enough to accommodate all the processing requirements. The wireless device may perform, after the warming up, timing acquisition from SSB and coarse synchronization, frequency and time tracking, time and frequency offset compensation, and/or calibration of local oscillator. After that, the wireless device may monitor a PDCCH for a paging DCI in one or more PDCCH monitoring occasions based on configuration parameters of the PCCH configuration configured in SIB1. The configuration parameters of the PCCH configuration may be implemented based on example embodiments described above with respect to
In an example, a default BWP may be different from a dormant BWP. The configuration parameters may indicate one or more search spaces or one or more CORESETs configured on the default BWP. When a BWP inactivity timer expires or receiving a DCI indicating switching to the default BWP, a wireless device may switch to the default BWP as an active BWP. The wireless device, when the default BWP is in active, may perform at least one of: monitoring PDCCH on the default BWP of the SCell, receiving PDSCH on the default BWP of the SCell, transmitting PUSCH on the default BWP of the SCell, transmitting SRS on the default BWP of the SCell, and/or transmitting CSI report (e.g., periodic, aperiodic, and/or semi-persistent) for the default BWP of the SCell. In an example, when receiving a dormancy/non-dormancy indication indicating a dormant state for a SCell, the wireless device may switch to the dormant BWP as an active BWP of the SCell. In response to switching to the dormant BWP, the wireless device may perform at least one of: refraining from monitoring PDCCH on the dormant BWP of the SCell (or for the SCell if the SCell is cross-carrier scheduled by another cell), refraining from receiving PDSCH on the dormant BWP of the SCell, refraining from transmitting PUSCH on the dormant BWP of the SCell, refraining from transmitting SRS on the dormant BWP of the SCell, and/or transmitting CSI report (e.g., periodic, aperiodic, and/or semi-persistent) for the dormant BWP of the SCell.
As shown in
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As shown in
In an example, a power saving mechanism may be based on a go-to-sleep indication via a PSCH.
In an example, a power saving mechanism may be implemented by combining
In an example, one or more embodiments of
In an example, the wireless device may not be provided searchSpaceGroupIdList for a search space set. The embodiments of
In an example, if a wireless device is provided cellGroupsForSwitchList (e.g., based on example embodiments shown in
In an example, if a wireless device is provided searchSpaceGroupldList, the wireless device may reset PDCCH monitoring according to search space sets with group index 0, if provided by searchSpaceGroupIdList.
In an example, a wireless device may be provided by search SpaceSwitchDelay (e.g., as shown in
In an example, a wireless device may be provided, by search SpaceSwitch Timer (in units of slots, e.g., as shown in
In an example, searchSpaceSwitch Timer may be defined as a value in unit of slots for monitoring PDCCH in the active DL BWP of the serving cell before moving to a default search space group (e.g., search space group 0). For 15 kHz SCS, a valid timer value may be one of {1, . . . , 20}. For 30 KHz SCS, a valid timer value may be one of {1, . . . , 40}. For 60 KHz SCS, a valid timer value may be one of {1, . . . , 80}. In an example, the base station may configure a same timer value for all serving cells in the same CellGroupForSwitch.
As shown in
In an example, the wireless device may monitor PDCCH on a second SSS group (e.g., 2nd SSS group or a SSS with group index 1) based on configuration of SSS groups of a BWP of a cell. The wireless device may be provided by SearchSpaceSwitch Trigger a location of a search space set group switching flag field for a serving cell in a DCI format 2_0. The wireless device may receive a DCI. The DCI may indicate a SSS group switching for the cell, e.g., when a value of the search space set group switching flag field in the DCI format 2_0 is 0, the wireless device may start monitoring PDCCH according to search space sets with group index 0 and stop monitoring PDCCH according to search space sets with group index 1 for the serving cell. The wireless device may start monitoring the PDCCH according to search space set with group index 0 and stop monitoring PDCCH according to search space sets with group 1 at a first slot that is at least Pswitch symbols after the last symbol of the PDCCH with the DCI format 2_0.
In an example, if the wireless device monitors PDCCH for a serving cell according to a first SSS group (e.g., search space sets with group index 1), the wireless device may start monitoring PDCCH for the serving cell according to a second SSS group (e.g., search space sets with group index 0), and stop monitoring PDCCH according to the first SSS group, for the serving cell at the beginning of the first slot that is at least Pswitch symbols after a slot where the timer expires or after a last symbol of a remaining channel occupancy duration for the serving cell that is indicated by DCI format 2_0.
In an example, a wireless device may not be provided Search SpaceSwitch Trigger for a serving cell, e.g., Search SpaceSwitch Trigger being absent in configuration parameters of SlotFormatIndicator, wherein the SlotFormatIndicator is configured for monitoring a Group-Common-PDCCH for Slot-Format-Indicators (SFI). In response to the SearchSpaceSwitch Trigger not being provided, the DCI format 2_0 may not comprise a SSS group switching flag field. When the SearchSpaceSwitchTrigger is not provided, if the wireless device detects a DCI format by monitoring PDCCH according to a first SSS group (e.g., a search space set with group index 0), the wireless device may start monitoring PDCCH according to a second SSS group (e.g., a search space sets with group index 1) and stop monitoring PDCCH according to the first SSS group, for the serving cell. The wireless device may start monitoring PDCCH according to the second SSS group and stop monitoring PDCCH according to the first SSS group at a first slot that is at least Pswitch symbols after the last symbol of the PDCCH with the DCI format. The wireless device may set (or restart) the timer value to the value provided by searchSpaceSwitch Timer if the wireless device detects a DCI format by monitoring PDCCH in any search space set.
In an example, a wireless device may not be provided SearchSpaceSwitch Trigger for a serving cell. When the SearchSpaceSwitch Trigger is not provided, if the wireless device monitors PDCCH for a serving cell according to a first SSS group (e.g., a search space sets with group index 1), the wireless device may start monitoring PDCCH for the serving cell according to a second SSS group (e.g., a search space sets with group index 0), and stop monitoring PDCCH according to the first SSS group, for the serving cell at the beginning of the first slot that is at least Pswitch symbols after a slot where the timer expires or, if the wireless device is provided a search space set to monitor PDCCH for detecting a DCI format 2_0, after a last symbol of a remaining channel occupancy duration for the serving cell that is indicated by DCI format 2_0.
In an example, a wireless device may determine a slot and a symbol in a slot to start or stop PDCCH monitoring according to search space sets for a serving cell that the wireless device is provided searchSpaceGroupIdList or, if cellGroupsForSwitchList is provided, for a set of serving cells, based on the smallest SCS configuration u among all configured DL BWPs in the serving cell or in the set of serving cells and, if any, in the serving cell where the wireless device receives a PDCCH and detects a corresponding DCI format 2_0 triggering the start or stop of PDCCH monitoring according to search space sets.
In an example, a wireless device may perform PDCCH skipping mechanism for power saving operation.
In an example, a base station may transmit to a wireless device one or more RRC messages comprising configuration parameters of PDCCH for a BWP of a cell (e.g., based on example embodiments described above with respect to
As shown in
As shown in
In an example, a base station may transmit one or more SSBs periodically to a wireless device, or a plurality of wireless devices. The wireless device (in RRC_idle state, RRC_inactive state, or RRC_connected state) may use the one or more SSBs for time and frequency synchronization with a cell of the base station. An SSB, comprising a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), a PBCH DM-RS, may be transmitted based on example embodiments described above with respect to
In an example, the base station may indicate a transmission periodicity of SSB via RRC message (e.g., ssb-PeriodicityServingCell in ServingCellConfigCommonSIB of SIB1 message, as shown in
In an example, a starting OFDM symbol index of a candidate SSB (occupying 4 OFDM symbols) within a SSB burst (5 ms) may depend on a subcarrier spacing (SCS) and a carrier frequency band of the cell.
As shown in
In an example, the SSB bust (also for each SSB of the SSB burst) may be transmitted in a periodicity. In the example of
In an example embodiment, a base station may transmit a RRC messages (e.g., SIB1) indicating cell specific configuration parameters of SSB transmission. The cell specific configuration parameters may comprise a value for a transmission periodicity (ssb-PeriodicityServingCell) of a SSB burst, locations of a number of SSBs (e.g., active SSBs), of a plurality of candidate SSBs, comprised in the SSB burst. The plurality of candidate SSBs may be implemented based on example embodiments described above with respect to
In the example of
As shown in
In the example of
In an example embodiment, when fc≤3 GHz, maximum number of SSBs within SS burst equals to four and a wireless device may determine that the four leftmost bits of a bitmap (e.g., the first bitmap and/or the second bitmap) are valid. The wireless device may ignore the 4 rightmost bits of the first bitmap and/or the second bitmap.
In the example of
In an example, a base station may transmit a Master Information Block (MIB) on PBCH, to indicate configuration parameters (for CORESET #0) for a wireless device monitoring PDCCH for scheduling a SIB1 message. The base station may transmit a MIB message with a transmission periodicity of 80 ms. The same MIB message may be repeated (according to SSB periodicity) within the 80 ms. Contents of a MIB message are same over 80 ms period. The same MIB is transmitted over all SSBs within a SS burst. In an example, PBCH may indicate that there is no associated SIB1, in which case a wireless device may be pointed to another frequency from where to search for an SSB that is associated with a SIB1 as well as a frequency range where the wireless device may assume no SSB associated with SIB1 is present. The indicated frequency range may be confined within a contiguous spectrum allocation of the same operator in which SSB is detected.
In an example, a base station may transmit a SIB1 message with a periodicity of 160 ms. The base station may transmit the same SIB1 message with variable transmission repetition periodicity within 160 ms. A default transmission repetition periodicity of SIB1 is 20 ms. The base station may determine an actual transmission repetition periodicity based on network implementation. In an example, for SSB and CORESET multiplexing pattern 1, SIB1 repetition transmission period is 20 ms. For SSB and CORESET multiplexing pattern 2/3, SIB1 transmission repetition period is the same as the SSB period. SIB1 may comprise information regarding the availability and scheduling (e.g., mapping of SIBs to SI message, periodicity, SI-window size) of other SIBs, an indication whether one or more SIBs are only provided on-demand and in which case, configuration parameters needed by a wireless device to perform an SI request.
where c(i) is a pseudo-random sequence with a pseudo-random sequence generator being initialized with cinit=(210(Nsymbslot ns,fμ+1+1) (2nID+1)+nID) mod 231 at the start of each OFDM symbol where nID is the slot number within a radio frame, l is the OFDM symbol number within a slot, and nID equals the higher-layer parameter scramblingID or sequenceGenerationConfig. The scramblingID or sequenceGenerationConfig may be implemented based on example embodiments of
In an example, for each CSI-RS configured, the wireless device may determine the sequence r(m) being mapped to resources elements (k,l)p,μ according to
In an example, the reference point for k=0 is subcarrier 0 in common resource block 0. The value of ρ is given by the higher-layer parameter density in CSI-RS-ResourceMapping IE or CSI-RS-CellMobility IE and the number of ports X is given by the higher-layer parameter nrofPorts.
In an example, the wireless device is not expected to receive CSI-RS and DM-RS on the same resource elements.
In an example, a wireless device may assume (or determine) βCSIRS>0 for a non-zero-power CSI-RS where βCSIRS is selected such that the power offset specified by the higher-layer parameter powerControlOffsetSS in the NZP-CSI-RS-Resource IE, if provided, is fulfilled. An NZP-CSI-RS is a CSI-RS with non-zero power transmission, which is contrast to ZP-CSI-RS which is a CSI-RS with zero power transmission.
In an example, the quantities k′, l′, wf(k′), and wt(l′) are given by one or more tables (e.g., as shown in
In an example, time-domain locations l0∈{0, 1, . . . , 13} and l1∈{2, 3, . . . , 12} are provided by the higher-layer parameters firstOFDMSymbolInTimeDomain and firstOFDMSymbolInTimeDomain2, respectively, in the CSI-RS-ResourceMapping IE or the CSI-RS-ResourceConfigMobility IE and defined relative to the start of a slot.
In an example, frequency-domain location is given by a bitmap provided by the higher-layer parameter frequency DomainAllocation in the CSI-RS-ResourceMapping IE or the CSI-RS-ResourceConfigMobility IE with the bitmap and value of k; in the table (as shown in
In an example, a wireless device may determine that a CSI-RS is transmitted using antenna ports p numbered according to
where s is the sequence index provided by Tables 7.4.1.5.3-2 to 7.4.1.5.3-5 of TS 38.211, L∈{1,2,4,8} is the CDM group size, and N is the number of CSI-RS ports. The CDM group index j given in Table 7.4.1.5.3-1 (as shown in
In an example, a wireless device may assume that antenna ports within a CSI-RS resource are quasi co-located with QCL Type A, Type D (when applicable), and average gain.
As shown in
As shown in
In an example, the base station may configure a plurality of CSI-RS resource sets, each CSI-RS resource set comprising a plurality of CSI-RS resources. As shown in
In an example, the base station may configure a plurality of CSI resource configurations. As shown in
In an example, as shown in
In an example, as shown in
As shown in
In an example, a base station may transmit, each CSI-RS resource, of the CSI-RS resource set, with different spatial domain filter (or transmission beam), in response to the repetition indicator, of the CSI-RS resource set, being set to ‘off’. Based on transmitting each CSI-RS resource in different beam, a wireless device may perform downlink beam management (e.g., P2 in
In an example, a base station may transmit, each CSI-RS resource, of the CSI-RS resource set, with the same spatial domain filter (or transmission beam), in response to the repetition indicator, of the CSI-RS resource set, being set to ‘on’. Based on transmitting each CSI-RS resource in the same beam, a wireless device may perform downlink beam management (e.g., P3 in
In the example of
Based on example embodiments of
In an example, a wireless device may transmit periodic CSI report, aperiodic CSI report and/or semi-persistent CSI report to a base station. The time and frequency resources that may be used by the wireless device to report CSI are controlled by the base station. CSI may consist of Channel Quality Indicator (CQI), precoding matrix indicator (PMI), CSI-RS resource indicator (CRI), SS/PBCH Block Resource indicator (SSBRI), layer indicator (LI), rank indicator (RI), L1-RSRP or L1-SINR.
Based on
Based on
In an example, each CSI Resource Setting CSI-ResourceConfig (e.g., as shown in
In an example, time domain behavior of the CSI-RS resources within a CSI Resource Setting are indicated by the higher layer parameter resource Type and may be set to aperiodic, periodic, or semi-persistent (e.g., based on example of
For periodic and semi-persistent CSI Resource Settings, the configured periodicity and slot offset is given in the numerology of its associated DL BWP, as given by BWP-id. When a wireless device is configured with multiple CSI-ResourceConfigs including the same NZP CSI-RS resource ID, the same time domain behavior may be configured for the CSI-ResourceConfigs. When a wireless device is configured with multiple CSI-ResourceConfigs including the same CSI-IM resource ID, the same time-domain behavior may be configured for the CSI-ResourceConfigs. All CSI Resource Settings linked to a CSI Report Setting may have the same time domain behavior.
In an example, for L1-SINR measurement, when one Resource Setting is configured, the Resource Setting (given by higher layer parameter resourcesForChannelMeasurement) is for channel and interference measurement on NZP CSI-RS for L1-SINR computation. A wireless device may assume that same 1 port NZP CSI-RS resource(s) with density 3 REs/RB is used for both channel and interference measurements.
In an example, for L1-SINR measurement, when two Resource Settings are configured, the first one Resource Setting (given by higher layer parameter resourcesForChannelMeasurement) is for channel measurement on SSB or NZP CSI-RS and the second one (given by either higher layer parameter csi-IM-ResourcesForInterference or higher layer parameter nzp-CSI-RS-ResourcesForInterference) is for interference measurement performed on CSI-IM or on 1 port NZP CSI-RS with density 3 REs/RB, where each SSB or NZP CSI-RS resource for channel measurement is associated with one CSI-IM resource or one NZP CSI-RS resource for interference measurement by the ordering of the SSB or NZP CSI-RS resource for channel measurement and CSI-IM resource or NZP CSI-RS resource for interference measurement in the corresponding resource sets. The number of SSB(s) or CSI-RS resources for channel measurement equals to the number of CSI-IM resources or the number of NZP CSI-RS resource for interference measurement. In this case, a wireless device may apply the SSB, or ‘typeD’ RS configured with qcl-Type set to ‘typeD’ to the NZP CSI-RS resource for channel measurement, as the reference RS for determining ‘typeD’ assumption for the corresponding CSI-IM resource or the corresponding NZP CSI-RS resource for interference measurement configured for one CSI reporting. A wireless device may expect that the NZP CSI-RS resource set for channel measurement and the NZP-CSI-RS resource set for interference measurement, if any, are configured with the higher layer parameter repetition.
In an example, for semi-persistent or periodic CSI, each CSI-ReportConfig is linked to periodic or semi-persistent Resource Setting(s). When one Resource Setting (given by higher layer parameter resourcesForChannelMeasurement) is configured, the Resource Setting is for channel measurement for L1-RSRP or for channel and interference measurement for L1-SINR computation. When two Resource Settings are configured, the first Resource Setting (given by higher layer parameter resourcesForChannelMeasurement) is for channel measurement and the second Resource Setting (e.g., by csi-IM-ResourcesForInterference) is used for interference measurement performed on CSI-IM. For L1-SINR computation, the second Resource Setting (given by higher layer parameter csi-IM-ResourcesForInterference or higher layer parameter nzp-CSI-RS-ResourceForInterference) is used for interference measurement performed on CSI-IM or on NZP CSI-RS.
In an example, for L1-RSRP computation, a wireless device may be configured with CSI-RS resources, SS/PBCH Block resources or both CSI-RS and SS/PBCH block resources, when resource-wise quasi co-located with ‘type C’ and ‘typeD’ when applicable. The wireless device may be configured with CSI-RS resource setting up to 16 CSI-RS resource sets having up to 64 resources within each set. The total number of different CSI-RS resources over all resource sets is no more than 128.
In an example, for L1-RSRP reporting, if the higher layer parameter nrofReportedRS in CSI-ReportConfig is configured to be one, the reported L1-RSRP value is defined by a 7-bit value in the range [−140,−44] dBm with 1 dB step size, if the higher layer parameter nrofReportedRS is configured to be larger than one, or if the higher layer parameter groupBasedBeamReporting is configured as ‘enabled’, or if the higher layer parameter groupBasedBeamReporting-r17 is configured, the wireless device may use differential L1-RSRP based reporting, where the largest measured value of L1-RSRP is quantized to a 7-bit value in the range [−140,−44] dBm with 1 dB step size, and the differential L1-RSRP is quantized to a 4-bit value. The differential L1-RSRP value is computed with 2 dB step size with a reference to the largest measured L1-RSRP value which is part of the same L1-RSRP reporting instance. The mapping between the reported L1-RSRP value and the measured quantity is described in TS 38.133.
In an example, when the higher layer parameter groupBasedBeamReporting-r17 in CSI-ReportConfig is configured, the wireless device may indicate the CSI Resource Set associated with the largest measured value of L1-RSRP, and for each group, CRI or SSBRI of the indicated CSI Resource Set is present first.
In an example, if the higher layer parameter timeRestrictionForChannelMeasurements in CSI-ReportConfig is set to “notConfigured”, the wireless device may derive the channel measurements for computing L1-RSRP value reported in uplink slot n based on only the SS/PBCH or NZP CSI-RS, no later than the CSI reference resource, (defined in TS 38.211) associated with the CSI resource setting.
In an example, if the higher layer parameter timeRestrictionForChannelMeasurements in CSI-ReportConfig is set to “Configured”, the wireless device may derive the channel measurements for computing L1-RSRP reported in uplink slot n based on only the most recent, no later than the CSI reference resource, occasion of SS/PBCH or NZP CSI-RS (defined in TS 38.211) associated with the CSI resource setting.
In an example, for L1-SINR computation, for channel measurement the wireless device may be configured with NZP CSI-RS resources and/or SS/PBCH Block resources, for interference measurement the wireless device may be configured with NZP CSI-RS or CSI-IM resources. for channel measurement, the wireless device may be configured with CSI-RS resource setting with up to 16 resource sets, with a total of up to 64 CSI-RS resources or up to 64 SS/PBCH Block resources.
In an example, for L1-SINR reporting, if the higher layer parameter nrofReportedRS in CSI-ReportConfig is configured to be one, the reported L1-SINR value is defined by a 7-bit value in the range [−23, 40] dB with 0.5 dB step size, and if the higher layer parameter nrofReportedRS is configured to be larger than one, or if the higher layer parameter groupBasedBeamReporting is configured as ‘enabled’, the wireless device may use differential L1-SINR based reporting, where the largest measured value of L1-SINR is quantized to a 7-bit value in the range [−23, 40] dB with 0.5 dB step size, and the differential L1-SINR is quantized to a 4-bit value. The differential L1-SINR is computed with 1 dB step size with a reference to the largest measured L1-SINR value which is part of the same L1-SINR reporting instance. When NZP CSI-RS is configured for channel measurement and/or interference measurement, the reported L1-SINR values should not be compensated by the power offset(s) given by higher layer parameter powerControOffsetSS or powerControlOffset.
In an example, when one or two resource settings are configured for L1-SINR measurement, if the higher layer parameter timeRestrictionForChannelMeasurements in CSI-ReportConfig is set to ‘notConfigured’, the wireless device may derive the channel measurements for computing L1-SINR reported in uplink slot n based on only the SSB or NZP CSI-RS, no later than the CSI reference resource, (defined in TS 38.211) associated with the CSI resource setting. If the higher layer parameter timeRestrictionForChannelMeasurements in CSI-ReportConfig is set to ‘configured’, the wireless device may derive the channel measurements for computing L1-SINR reported in uplink slot n based on only the most recent, no later than the CSI reference resource, occasion of SSB or NZP CSI-RS (defined in TS 38.211) associated with the CSI resource setting. If the higher layer parameter timeRestrictionForInterferenceMeasurements in CSI-ReportConfig is set to ‘notConfigured’, the wireless device may derive the interference measurements for computing L1-SINR reported in uplink slot n based on only the CSI-IM or NZP CSI-RS for interference measurement (defined in TS 38.211) or NZP CSI-RS for channel and interference measurement no later than the CSI reference resource associated with the CSI resource setting. If the higher layer parameter timeRestrictionForInterferenceMeasurements in CSI-ReportConfig is set to ‘configured’, the wireless device may derive the interference measurements for computing the L1-SINR reported in uplink slot n based on the most recent, no later than the CSI reference resource, occasion of CSI-IM or NZP CSI-RS for interference measurement (TS 38.211) or NZP CSI-RS for channel and interference measurement associated with the CSI resource setting.
In an example, a wireless device may derive CSI report based on SS/PBCH block and/or CSI-RSs. The wireless device may measure SS-RSRP (L1-RSRP) (also described in specification of TS 38.215) within a SMTC occasion based on the SS-RSRP being defined as the linear average over the power contributions (in [W]) of the REs that carry SSSs. For SS-RSRP determination based on DM-RS for PBCH and, if indicated by higher layers, the wireless device may use CSI-RSs in addition to SSSs for SS-RSRP measurement. The wireless device may measure SS-RSRP using DM-RS for PBCH or CSI-RSs by linear averaging over the power contributions of the REs that carry corresponding RSs taking into account power scaling for the RSs. If SS-RSRP is not used for L1-RSRP, the additional use of CSI-RS for SS-RSRP determination is not applicable. The wireless device may measure SS-RSRP only among the reference signals corresponding to SS/PBCH blocks with the same SS/PBCH block index and the same physical-layer cell identity. The wireless device may measure SS-RSRP only from an indicated set of SS/PBCH block(s) if SS-RSRP is not used for L1-RSRP and higher-layers indicate the set of SS/PBCH blocks for performing SS-RSRP measurements. The wireless device may determine, for frequency range 1, a reference point for the SS-RSRP measurement as an antenna connector of the wireless device. The wireless device may, for frequency range 2, measure SS-RSRP based on a combined signal from antenna elements corresponding to a given receiver branch. For frequency range 1 and 2, if receiver diversity is in use by the wireless device, the wireless device may report SS-RSRP with a value not lower than the corresponding SS-RSRP of any of the individual receiver branches.
In an example, the wireless device may measure CSI-RSRP (L1-RSRP) (also described in specification of TS 38.215) based on the CSI-RSRP being defined as the linear average over the power contributions (in [W]) of the resource elements of the antenna port(s) that carry CSI reference signals configured for RSRP measurements within the considered measurement frequency bandwidth in the configured CSI-RS occasions. For CSI-RSRP determination CSI reference signals transmitted on antenna port 3000 may be used. If CSI-RSRP is used for L1-RSRP, CSI reference signals transmitted on antenna ports 3000, 3001 may be used for CSI-RSRP determination. For intra-frequency CSI-RSRP measurements, if the measurement gap is not configured, wireless device is not expected to measure the CSI-RS resource(s) outside of the active downlink bandwidth part. For frequency range 1, the reference point for the CSI-RSRP may be the antenna connector of the UE. For frequency range 2, CSI-RSRP may be measured based on the combined signal from antenna elements corresponding to a given receiver branch. For frequency range 1 and 2, if receiver diversity is in use by the UE, the reported CSI-RSRP value may not be lower than the corresponding CSI-RSRP of any of the individual receiver branches.
In an example, the wireless device may measure SS-RSRQ (L1-RSRQ) (also described in specification of TS 38.215) based on SS-RSRQ being defined as the ratio of N×SS-RSRP/NR carrier RSSI, where N is the number of resource blocks in the NR carrier RSSI measurement bandwidth. The measurements in the numerator and denominator may be made over the same set of resource blocks. NR carrier Received Signal Strength Indicator (NR carrier RSSI), comprises the linear average of the total received power (in [W]) observed only in certain OFDM symbols of measurement time resource(s), in the measurement bandwidth, over N number of resource blocks from all sources, including co-channel serving and non-serving cells, adjacent channel interference, thermal noise etc. For cell selection, the measurement time resources(s) for NR Carrier RSSI are not constrained. Otherwise, the measurement time resource(s) for NR Carrier RSSI are confined within SMTC window duration. If indicated by higher-layers, if measurement gap is not used, the NR Carrier RSSI is measured in slots within the SMTC window duration that are indicated by the higher layer parameter measurementSlots and in predefined OFDM symbols and, if measurement gap is used, the NR Carrier RSSI is measured in slots within the SMTC window duration that are indicated by the higher layer parameter measurementSlots and in the predefined OFDM symbols that are overlapped with the measurement gap. For intra-frequency measurements, NR Carrier RSSI is measured with timing reference corresponding to the serving cell in the frequency layer. For inter-frequency measurements, NR Carrier RSSI is measured with timing reference corresponding to any cell in the target frequency layer. Otherwise not indicated by higher-layers, if measurement gap is not used, NR Carrier RSSI is measured from OFDM symbols within SMTC window duration and, if measurement gap is used, NR Carrier RSSI is measured from OFDM symbols corresponding to overlapped time span between SMTC window duration and the measurement gap. If higher-layers indicate certain SS/PBCH blocks for performing SS-RSRQ measurements, then SS-RSRP is measured only from the indicated set of SS/PBCH block(s). For frequency range 1, the reference point for the SS-RSRQ may be the antenna connector of the UE. For frequency range 2, NR Carrier RSSI may be measured based on the combined signal from antenna elements corresponding to a given receiver branch, where the combining for NR Carrier RSSI may be the same as the one used for SS-RSRP measurements. For frequency range 1 and 2, if receiver diversity is in use by the UE, the reported SS-RSRQ value may not be lower than the corresponding SS-RSRQ of any of the individual receiver branches.
In an example, the wireless device may measure CSI-RSRQ (L1-RSRQ) (also described in specification of TS 38.215) based on CSI-RSRQ being defined as the ratio of N×CSI-RSRP to CSI-RSSI, where N is the number of resource blocks in the CSI-RSSI measurement bandwidth. The measurements in the numerator and denominator may be made over the same set of resource blocks. CSI Received Signal Strength Indicator (CSI-RSSI), comprises the linear average of the total received power (in [W]) observed only in OFDM symbols of measurement time resource(s), in the measurement bandwidth, over N number of resource blocks from all sources, including co-channel serving and non-serving cells, adjacent channel interference, thermal noise etc. The measurement time resource(s) for CSI-RSSI corresponds to OFDM symbols containing configured CSI-RS occasions. For CSI-RSRQ determination CSI reference signals transmitted on antenna port 3000 may be used. For intra-frequency CSI-RSRQ measurements, if the measurement gap is not configured, wireless device is not expected to measure the CSI-RS resource(s) outside of the active downlink bandwidth part. For frequency range 1, the reference point for the CSI-RSRQ may be the antenna connector of the UE. For frequency range 2, CSI-RSSI may be measured based on the combined signal from antenna elements corresponding to a given receiver branch, where the combining for CSI-RSSI may be the same as the one used for CSI-RSRP measurements. For frequency range 1 and 2, if receiver diversity is in use by the UE, the reported CSI-RSRQ value may not be lower than the corresponding CSI-RSRQ of any of the individual receiver branches.
In an example, the wireless device may measure SS-SINR (L1-SINR) (also described in specification of TS 38.215) based on SS-SINR being defined as the linear average over the power contribution (in [W]) of the resource elements carrying SS signals divided by the linear average of the noise and interference power contribution (in [W]). If SS-SINR is used for L1-SINR reporting with dedicated interference measurement resources, the interference and noise is measured over resource(s) indicated by higher layers. Otherwise, the interference and noise are measured over the resource elements carrying SS signals within the same frequency bandwidth. The measurement time resource(s) for SS-SINR are confined within SMTC window duration. If SS-SINR is used for L1-SINR as configured by reporting configurations, the measurement time resources(s) restriction by SMTC window duration is not applicable. For SS-SINR determination demodulation reference signals for physical broadcast channel (PBCH) in addition to secondary synchronization signals may be used. If SS-SINR is not used for L1-SINR and higher-layers indicate certain SS/PBCH blocks for performing SS-SINR measurements, then SS-SINR is measured only from the indicated set of SS/PBCH block(s). For frequency range 1, the reference point for the SS-SINR may be the antenna connector of the UE. For frequency range 2, SS-SINR may be measured based on the combined signal from antenna elements corresponding to a given receiver branch. For frequency range 1 and 2, if receiver diversity is in use by the UE, the reported SS-SINR value may not be lower than the corresponding SS-SINR of any of the individual receiver branches.
In an example, the wireless device may measure CSI-SINR (L1-SINR) (also described in specification of TS 38.215) based on CSI-SINR being defined as the linear average over the power contribution (in [W]) of the resource elements carrying CSI reference signals divided by the linear average of the noise and interference power contribution (in [W]). If CSI-SINR is used for L1-SINR reporting with dedicated interference measurement resources, the interference and noise is measured over resource(s) indicated by higher layers. Otherwise, the interference and noise are measured over the resource elements carrying CSI reference signals within the same frequency bandwidth. For CSI-SINR determination CSI reference signals transmitted on antenna port 3000 may be used. If CSI-SINR is used for L1-SINR, CSI reference signals transmitted on antenna ports 3000, 3001 may be used for CSI-SINR determination. For intra-frequency CSI-SINR measurements not used for L1-SINR reporting, if the measurement gap is not configured, wireless device is not expected to measure the CSI-RS resource(s) outside of the active downlink bandwidth part. For frequency range 1, the reference point for the CSI-SINR may be the antenna connector of the UE. For frequency range 2, CSI-SINR may be measured based on the combined signal from antenna elements corresponding to a given receiver branch. For frequency range 1 and 2, if receiver diversity is in use by the UE, the reported CSI-SINR value may not be lower than the corresponding CSI-SINR of any of the individual receiver branches.
Based on
In an example, network energy saving may be of great importance for environmental sustainability, to reduce environmental impact (greenhouse gas emissions), and for operational cost savings. As 5G is becoming pervasive across industries and geographical areas, handling more advanced services and applications requiring very high data rates (e.g., XR), networks may become denser, use more antennas, larger bandwidths and more frequency bands. The environmental impact of 5G may need to stay under control, and novel solutions to improve network energy savings need to be developed.
In existing technologies, a base station, when a wireless device does not have data traffic to transmit/receive, may indicate the wireless device to perform power saving operations, e.g., based on examples described above with respect to
In existing technologies, a base station, when there is no active wireless devices in the coverage of the base station, may still transmit some always-on signals (e.g., MIB, SIB1, SSBs, periodical CSI-RSs, discovery RS, etc.). If the base station needs to reduce transmission power of the always-on downlink signal transmission and/or reduce beams/antenna port of transmission of the always-on downlink signal, the base station may transmit a RRC message (e.g., SIB1, cell-specific RRC message, UE-specific RRC message, etc.) indicating a reduced transmission power for the always-on downlink signal transmission and/or a reduced number of beams (e.g., by ssb-PositionsInBurst) for the always-on downlink signal transmission, e.g., based on example embodiments described above with respect to
In existing implementations of wireless systems, SIB1 may be transmitted with a fixed transmission periodicity of 160 ms (with repetition transmissions within 160 ms). The contents of SIB transmission may be same among the repetition transmissions within 160 ms. The base station may transmit, at least 160 ms after transmitting a first SIB1, a second SIB1 indicating a change of SSB transmission power, SSB transmission periodicity and/or SSB locations in a SSB burst.
In existing technologies, a base station may configure (by RRC messages) a plurality of NZP-CSI-RS resource sets for a wireless device. In an example, for aperiodic resource type, at most maxNrofNZP-CSI-RS-ResourceSetsPerConfig (which may be 16) NZP-CSI-RS resource sets may be configured. For the periodic resource type, at most 1 resource set may be configured. For each CSI-RS resource set, at most maxNrofNZP-CSI-RS-ResourcesPerSet (which may be 64) NZP-CSI-RS resources may be configured.
In existing technologies, for CSI report, a number (e.g., at most 8) of NZP-CSI-RS resources may be configured for an NZP-CSI-RS resource set. For periodic CSI-RS type, an NZP-CSI-RS resource may be configured with a transmission periodicity (e.g., a value of 4 slots, 5 slots, 8 slots, 10 slots, 16 slots, 20 slots, 32 slots, 40 slots, 64 slots, 80 slots, 160 slots, 320 slots, 640 slots and etc.). In an example, when a CSI-RS resource is 1 port, the density may be at most 3 REs/RB. A CSI-RS resource may be mapped to a plurality of RBs (e.g., multiples of 4) comprised in a cell. The smallest configurable number is the minimum of 24 and the width of the associated BWP. If the configured value is larger than the width of the corresponding BWP, the wireless device may assume that the actual CSI-RS bandwidth is equal to the width of the BWP.
In existing technologies, when configured with periodic NZP-CSI-RS resources (and resource set(s), the base station may keep transmitting the periodic NZP-CSI-RS resources according to the configuration parameters of the periodic NZP-CSI-RS resources, e.g., with a transmission density, a transmission periodicity, a number of CSI-RS resources, a transmission bandwidth, a number of antenna ports, etc. Different from aperiodic NZP-CSI-RS resources (which is triggered by DCI and is transmitted one-shot by the base station) or semi-persistent CSI-RS resources (which is activated by a first SP-CSI-RS resource set Activation/Deactivation MAC CE and is transmitted by the base station until deactivated by second SP-CSI-RS resource set Activation/Deactivation MAC CE), the base station may keep transmitting the periodic NZP-CSI-RS resources, even when there are few wireless devices in the cell, or no (active) wireless device in the cell. The periodic NZP-CSI-RSs may be transmitted based on example embodiments described above with respect to
There is a need to dynamically reduce power consumption of a base station for transmission of periodic CSI-RSs, especially when there is no load or light load in coverage of a cell of the base station.
Example embodiments may comprise a base station dynamically adjusting P-CSI-RS transmission parameters, by transmitting a MAC CE and/or a DCI, when the base station transitions from a non-energy-saving state to an energy saving state. A search space, a DCI format, and/or a control resource set, associated with the DCI for the energy saving indication, may be configured by the base station in one or more RRC messages. The adjusted parameters, of the P-CSI-RS transmissions, may comprise at least one of: a number of beams, a number of antenna ports, a transmission density, a transmission periodicity, a transmission bandwidth, etc. The MAC CE/DCI may comprise a bitfield with a codepoint indicating which P-CSI-RS resource (or set) of a plurality of P-CSI-RSs (or sets) will be switched on (or switched off) in the energy saving state. The MAC CE/DCI may comprise a bitmap wherein each bit of the bitmap corresponds to a respective P-CSI-RS resource (or set) of the plurality of P-CSI-RS resource (or sets) and indicates whether to switch off the transmission of the corresponding P-CSI-RS resource (or set). The bitfield and/or the bitmap may be configured by the base station for a DCI format to indicate the P-CSI-RS switch on/off. Based on receiving the MAC CE/DCI indicating the adjusted parameters, the wireless device may adjust channel quality monitoring or beam management procedure according to the adjusted CSI-RS parameters. The wireless device may obtain correct CSI report and/or beam report for the base station in the energy saving state. Example embodiments may improve power consumption of the base station for transmitting P-CSI-RS resources because, for example, the base station may be enabled to dynamically switch off transmission of some P-CSI-RS resources. Example embodiments may allow the base station to obtain accurate CSI/beam report, in the energy saving state, which may be used for maintaining connection with the wireless device and/or may be used as initial CSI/beam report later when the base station switches to the non-energy-saving state from the energy saving state.
Example embodiments may comprise a base station switching off periodical transmissions of P-CSI-RSs (or P-CSI-RS resource set(s)), in response to transmitting a DCI indicating an energy saving. The base station may keep transmitting the SSBs (or one or more of the SSBs) based on a periodicity, in response to transmitting the DCI indicating the energy saving. In response to receiving the DCI, a wireless device may determine that the P-CSI-RSs (configured in RRC messages) are switched off by the base station. In response to receiving the DCI, the wireless device may determine that the SSBs are still being periodically transmitted by the base station (with or without parameter changes based on configuration or indication of the RRC message, a MAC CE and/or the DCI). Also, the DCI indicating the energy saving may indicate to the wireless device of a portion of the P-CSI-RSs that are switched off and that will no longer be transmitted by the base station. The wireless device may obtain (or measure) periodic CSI quantities based on SSBs for a cell (e.g., when the cell is transitioned into an energy saving state by the base station, or when the base station is in the energy saving state). Also, based on the DCI, the wireless device will not receive the P-CSI-RSs that are switched off and may stop obtaining periodic CSI quantities of those switched off P-CSI-RSs.
In an example, based on the one or more RRC messages, the base station may transmit the P-CSI-RSs in the configured resources.
As shown in
In an example, the wireless device may further measure CSI quantities based on periodic transmitted SSBs. A SSB may be implemented based on example embodiments described above with respect to
In an example (e.g., in high frequency deployment), the base station may transmit SSBs with wider beams than the P-CSI-RSs. The base station transmits SSBs with wider beams to achieve sufficient coverage for multiple wireless devices in a cell. The base station transmits P-CSI-RSs with narrower beams to facilitate a specific wireless device to identify a good beam pair between the wireless device and the base station, e.g., for actual data/control information transmissions.
In an example, the wireless device, based on the measured CSI report, may transmit 1st periodic CSI report via uplink channel (e.g., PUCCH/PUSCH). The 1st periodic CSI report may comprise a plurality of CSI quantities (e.g., CQI, PMI, CRI, SSBRI, LI, RI, L1-RSRP, L1-SINR, and etc.), based on configuration parameters of the CSI report, as shown in
In an example, the 1st periodic CSI report measured via 1st P-CSI-RSs and/or SSBs may be referred to CSI report in normal power state (or non-energy-saving state). The 1st P-CSI-RSs transmitted by the base station may be referred to as CSI-RSs in normal power state.
In an example embodiment, the base station may determine to transition from a normal power state (or a non-energy-saving state) to an energy saving state, for one or more cells. The base station may transmit 1st number of P-CSI-RSs with 1st configuration parameters when the base station is in the normal power state. The base station may transmit 1st number of P-CSI-RSs (via a cell) with 1st transmission periodicity, with 1st transmission density, with 1st transmission bandwidth, with a first number of P-CSI-RSs (in a CSI-RS resource set), and/or with a first number of CSI-RS resource sets, in transmission occasions when the base station is in the normal power state. The base station may determine the transitioning based on wireless device assistance information, received from the wireless device, regarding traffic pattern, data volume, latency requirement, etc. In the example (not shown in
As shown in
In an example embodiment, the energy saving indication may be indicated by a MAC CE. The base station may transmit, and/or the wireless device may receive, a MAC CE comprising an energy saving indication. A MAC CE associated with a LCID identifying a specific usage of the MAC CE may be implemented based on example embodiments described above with respect to
In an example, a MAC CE comprising the energy saving indication may reuse an existing MAC CE. In an example, a R bit of SCell activation/deactivation MAC CE (based on example of
In an example embodiment, the search space, for transmission of the DCI indicating the energy saving, may be a type 0 common search space. The DCI comprising the energy saving indication may share a same type 0 common search space with other DCIs (e.g., scheduling SIBx message). The base station may transmit configuration parameter of the type 0 common search space in a MIB message or a SIB1 message. The base station transmits the MIB message via a PBCH and indicating system information of the base station. The base station transmits the SIB1 message, scheduled by a group common PDCCH with CRC scrambled by SI-RNTI, indicating at least one of: information for evaluating if a wireless device is allowed to access a cell of the base station, information for scheduling of other system information, radio resource configuration information that is common for all wireless devices, and barring information applied to access control.
In an example embodiment, the search space, for transmission of the DCI indicating the energy saving, may be a type 2 common search space. The DCI comprising the energy saving indication may share a same type 2 common search space with other DCIs (e.g., scheduling paging message) with CRC scrambled by P-RNTI.
In an example embodiment, the search space, for transmission of the DCI indicating the energy saving, may be a type 3 common search space. The DCI comprising the energy saving indication may share the same type 3 common search space with a plurality of group common DCIs. The plurality of group common DCIs may comprise: a DCI format 2_0 indicating slot format based on CRC bits scrambled by SFI-RNTI, a DCI format 2_1 indicating a downlink pre-emption based on CRC being scrambled by an INT-RNTI, a DCI format 2_4 indicating an uplink cancellation based on CRC being scrambled by a CI-RNTI, a DCI format 2_2/2_3 indicating uplink power control based on CRC bits being scrambled with TPC-PUSCH-RNTI, TPC-PUCCH-RNTI, or TPC-SRS-RNTI, a DCI format 2_6 indicating a power saving operation (wake-up/go-to-sleep and/or SCell dormancy) based on CRC bits being scrambled by PS-RNTI, etc.
In an example embodiment, the search space, for transmission of the DCI indicating the energy saving, may be a wireless device specific search space, different from common search spaces (type 0/0A/1/2/3).
In an example embodiment, the DCI indicating the energy saving may be a legacy DCI format (e.g., DCI format 1_0/1_1/1_2/0_0/0_1/0_2/2_0/2_1/2_2/2_3/2_4/2_5/2_6). The DCI may be a new DCI format, with a same DCI size as DCI format 2_0/2_1/2_2/2_3/2_4/2_5/2_6. The DCI may be a new DCI format with a same DCI size as DCI format 1_0/0_0. The DCI may be a new DCI format with a same DCI size as DCI format 1_1/0_1.
In an example embodiment, the configuration parameters of the one or more RRC messages may indicate that a control resource set of a plurality of control resource sets is associated with the search space for the DCI indicating the energy saving for the base station. The configuration parameters may indicate, for the control resource set, frequency radio resources, time domain resources, CCE-to-REG mapping type, etc.
In an example embodiment, the wireless device may monitor the search space (of the control resource set) for receiving the DCI indicating the energy saving for the base station. The base station may transmit the DCI, in one or radio resources associated with the search space (in the control resource set), comprising the energy saving indication for the base station.
In an example, a DCI (or the MAC CE), indicating the energy saving operation for the base station, may indicate second configuration parameters (density, bandwidth, antenna ports, number of resources of the resource set, etc.) of the P-CSI-RS resources. The DCI may have a DCI format (e.g., based on example embodiments of
In an example, the field may be a bitmap, wherein each bit of the bitmap may correspond to a respective CSI-RS of the 1st number of CSI-RSs and may indicate whether to switch off the corresponding CSI-RS. The bitmap may be implemented based on example embodiments of
In an example, the field may indicate a CSI-RS switching on/off pattern of a plurality of CSI-RS switching on/off patterns. The plurality of CSI-RS switching on/off patterns may be implemented based on example embodiments of
In an example, the field may indicate a second transmission periodicity of the P-CSI-RS resources. The second transmission periodicity may be longer than the first transmission periodicity for normal state (or non-energy-saving state). In an example, the second transmission periodicity of the P-CSI-RS resources for the energy saving operation may be configured by the base station or preconfigured without indication by the MAC CE and/or DCI.
In an example, the field may indicate a second transmission density of the P-CSI-RS resources. The second transmission density may be smaller than the first transmission density for the normal power state. In an example, the second transmission density of the P-CSI-RS resources for the energy saving operation may be configured by the base station or preconfigured without indication by the MAC CE and/or DCI.
In an example, the field may indicate a second transmission bandwidth of the P-CSI-RS resources. The second transmission bandwidth may be smaller than the first transmission bandwidth for the normal power state. In an example, the second transmission bandwidth of the P-CSI-RS resources for the energy saving operation may be configured by the base station or preconfigured without indication by the MAC CE and/or DCI.
In an example, the field may indicate a second transmission power of the P-CSI-RS resources. The second transmission power may be smaller than the first transmission power for the normal power state. In an example, the second transmission power of the P-CSI-RS resources for the energy saving operation may be configured by the base station or preconfigured without indication by the MAC CE and/or DCI.
Based on the transmitting the DCI, the base station may transition from the non-energy-saving state to an energy saving state. In an example, the base station, when in an energy saving state, may reduce transmission power, reduce transmission beams/ports, and/or increase transmission periodicity value of P-CSI-RSs (e.g., from 4 ms to 20 ms, from 20 ms to 40 ms, etc.), compared with a non-energy-saving state. A transmission periodicity of P-CSI-RSs may be implemented based on example embodiments described above with respect to
In an example, the base station, when in an energy saving state, may keep receiving uplink transmissions from wireless device(s).
In an example, the base station, when in the energy saving state, may maintain RRC connections (or may not break RRC connections) with one or more wireless devices which have set up RRC connections with one or more cells of the base station. The base station, in the energy saving state, may maintain existing interface(s) with other network entities (e.g., another base station, an AMF, a UPF, etc., as shown in
In an example, a transition from the non-energy-saving state to the energy saving state may comprise maintaining an active state of a BWP unchanged in the cell. Maintaining the active state of the BWP for the energy saving state transition may allow a quick switching (without BWP switching) between non-energy-saving state and energy saving state. A BWP switching may be implemented based on example embodiments described above with respect to
In an example, a transition from the non-energy-saving state to the energy saving state may comprising switching an active BWP from a first active BWP to a second BWP of the cell comprising a plurality of BWPs. Switching active BWPs for the energy saving state transition may simplify implementation of the wireless device and the base station, e.g., by maintaining backward compatibility. A BWP may be implemented based on example embodiments described above with respect to
As shown in
In an example, the base station may transmit the 3rd number of CSI-RSs with a second transmission periodicity, a second transmission density, a second transmission bandwidth and/or with a second number of antenna ports.
In an example, based on receiving the DCI indicating to switch off 2nd number of CSI-RSs from the 1st number of CSI-RSs, the wireless device may stop monitoring (or measuring) beam/CSI quantities for the 2nd number of CSI-RSs and/or may monitor 3rd number of CSI-RSs from the 1st number of CSI-RSs for beam/CSI measurements.
In an example, based on monitoring 3rd number of CSI-RSs (and/or stopping monitoring 2nd number of CSI-RSs, the wireless device may obtain 2nd periodic CSI report.
In an example, in the energy saving state, the wireless device may transmit 2nd periodic CSI report, obtained based on the 3rd number of CSI-RSs, to the base station.
In an example, in the energy saving state, the wireless device may skip transmitting 2nd periodic CSI report to the base station.
In an example, the base station may transmit a command (e.g., RRC/MAC CE/DCI) indicating whether the wireless device may transmit the 2nd periodic CSI report to the base station in the energy saving state. In response to the command indicating that the wireless device may transmit the 2nd periodic CSI report in the energy saving state, the wireless device may transmit the 2nd periodic CSI report to the base station in the energy saving state. In response to the command indicating that the wireless device may skip the transmission of the 2nd periodic CSI report in the energy saving state, the wireless device may skip the transmitting the 2nd periodic CSI report to the base station in the energy saving state. Example embodiments may allow the base station to flexibly control periodic CSI report transmission of a wireless device when the base station is in energy saving state.
Based on example embodiments of
In an example, one or more embodiments of
In an example, one or more embodiments of
In an example, one or more embodiments of
In an example, one or more embodiments of
In an example, a bitmap (in the MAC CE and/or the DCI for energy saving indication) described above may be 8 bits, e.g., when there are 8 P-CSI-RS resources in a P-CSI-RS resource set, or 16 bits when there are 16 P-CSI-RS resources in a P-CSI-RS resource set.
In an example embodiment, the bitmap described above may be replaced with a bit field, e.g., when the base station transmits few P-CSI-RS resources among a plurality of P-CSI-RS resources and/or switches off most of the plurality of P-CSI-RS resources in energy saving state. In an example, the base station may transmit RRC messages comprising configuration parameters indicating that the DCI format of the DCI comprises the bit field indicating the P-CSI-RS switch on/off. The base station may transmit a MAC CE/DCI, for indicating energy saving operation for the base station, comprising a bit field indicating to switch off one or more P-CSI-RS resources of a P-CSI-RS resource set. The bit field, being set to a codepoint, may indicate to transmit one or more P-CSI-RS resources of a plurality of P-CSI-RS resources of a P-CSI-RS resource set and to switch off the rest resources of the plurality of P-CSI-RS resources. In an example, the base station may transmit a single P-CSI-RS resource of a plurality of P-CSI-RS resources of a P-CSI-RS resource set in the energy saving state. Where there are 8 P-CSI-RS resources in the P-CSI-RS resource set, the bit field of the MAC CE/DCI may be 3 bits. The bit field set to a first codepoint (e.g., ‘000’) may indicate to transmit 1st P. CSI-RS resource, e.g., with the lowest CSI-RS resource index among CSI-RS resource indexes of the 8 P-CSI-RS resources and stop transmitting the rest 7 P-CSI-RS resources of the 8 P-CSI-RS resources of the P-CSI-RS resource set. The bit field set to a second codepoint (e.g., ‘001’) may indicate to transmit 2nd P-CSI-RS resource, e.g., with the second lowest CSI-RS resource index among CSI-RS resource indexes of the 8 P-CSI-RS resources and stop transmitting the rest 7 P-CSI-RS resources of the 8 P-CSI-RS resources of the P-CSI-RS resource set, etc. Example embodiments may further improve power consumption of the base station and reduce signaling overhead for energy saving indication with regard to dynamic switching off P-CSI-RS resources.
In the example of
In the example of
In an example, the first transmission beam may be same as the transmission beam used for CSI-RS with index 0 before the base station transmits the MAC CE or the DCI.
In an example, the first transmission beam may be different from the transmission beam used for CSI-RS with index 0 before the base station transmits the MAC CE or the DCI. The base station may determine the first transmission beam for the CSI-RS with index 0 based on a transmission beam of a SSB transmission.
Example embodiments of
In an example, a CSI-RS resource group may be CSI-RS resources within a CSI-RS resource set. The base station may transmit RRC messages comprising configuration parameters indicating that a CSI-RS resource set comprises a plurality of CSI-RS resource groups, for the energy saving operation, each CSI-RS resource group comprising CSI-RS resources. Based on example embodiment, the base station may switch off a subset (or a group) of CSI-RS resources from the plurality of CSI-RS resources comprised in a CSI-RS resource set, e.g., by transmitting the MAC CE and/or DCI comprising a per-group CSI-RS switching on/off indication.
In an example, the association between a bit and a set/group may be configured by the base station in RRC messages. The RRC messages may comprise configuration parameters, for the plurality of CSI-RS resource sets (or groups), wherein each set/group is associated with a location parameter indication a location of a bit in the bitmap for the set/group.
In an example, the association between a bit and a set/group may be predefined based on CSI-RS resource set/group indexes (e.g., in ascending or descending order of the set/group indexes). The first bit (or the rightmost bit) of the bitmap may correspond to the first CSI-RS resource set/group, with the lowest set/group index among set/group indexes of the plurality of CSI-RS resource sets/groups. The second bit (or the second rightmost bit) of the bitmap may correspond to the second CSI-RS resource set/group, with the second lowest set/group index among set/group indexes of the plurality of CSI-RS resource sets/groups. The last bit (or the leftmost bit) of the bitmap may correspond to the last CSI-RS resource set/group, with a highest set/group index among set/group indexes of the plurality of CSI-RS resource sets/groups, or verse visa.
In an example, the base station may switch off first CSI-RSs, of a plurality of CSI-RSs (in one or more CSI-RS resource sets) in a first time and switch off second CSI-RSs, of the plurality of CSI-RSs, in a second time. The base station may switch on/off different CSI-RS resources in different time when the base station is in energy saving state.
In an example, the base station may transmit a MAC CE and/or a DCI comprising an energy saving indication (e.g., based on examples of
In an example, as shown in
In an example, the 1st slots may be slots with even slot numbers and the 2nd slots may be slots with odd slot numbers, or verse vice.
In an example, the 1st slot(s) may be first occasion(s) of periodic transmission occasions of the P-CSI-RSs based on configuration parameters. The 2nd slot(s) may be second occasion(s) of the periodic transmission occasions of the P-CSI-RSs.
In an example, as shown in
In an example, the MAC CE and/or the DCI may comprise a field (with one or more bits) indicating one of the plurality of switching on/off patterns for P-CSI-RS transmissions.
In an example, the base station may indicate, from the plurality of switching on/off patterns, a (default) switching on/off pattern for P-CSI-RS transmissions in energy saving state. in response to transitioning from a non-energy-saving state to an energy saving state, the base station may use the (default) switching on/off pattern to determine to switch on/off P-CSI-RSs in different slots.
In an example, the (default) switching on/off pattern may be preconfigured as the first switching on/off pattern as shown in
Based on examples of
In an example, a wireless device may take a time period (duration, or gap) to adapt CSI/beam measurements when the base station dynamically (or semi-persistently) P-CSI-RS resource transmission parameters. The time duration may be determined based on a process capability (power amplifier, AGC, AD/DA converter, RF modules, etc.) of the wireless device. The time duration may be determined based on a process capability (power amplifier, AGC, AD/DA converter, RF modules, etc.) of the base station. When the base station transmits a DCI/MAC CE indicating to switch on/off P-CSI-RSs or adjust parameters of P-CSI-RSs, the wireless device may not be aware of when the base station will use (or switch to) new transmission parameters for P-CSI-RSs. When the base station transmits a DCI/MAC CE indicating P-CSI-RS parameter changes, the wireless device may not be able to catch up the speed of the transmission parameter changing at the base station due to limited capability of the wireless device. Existing technologies may cause misalignment between the base station and the wireless device regarding a timing of the P-CSI-RS transmission parameter adjustment. Misalignment regarding the timing of the P-CSI-RS transmission parameter adjustment may cause the wireless device to incorrectly measure beam/cell channel qualities. There is a need to align the P-CSI-RS transmission parameter adjustment between the base station and the wireless device when the base station dynamically adjusts P-CSI-RS transmission parameters.
In an example, the base station may transmit 1st CSI-RSs periodically according to the configuration parameters of the CSI-RSs. The wireless device may measure 1st CSI quantities according to the periodically transmitted 1st CSI-RSs. The wireless device may transmit 1st CSI quantities to the base station, e.g., based on example embodiments described above with respect to
As shown in
In the example of
As shown in
After receiving the DCI (or the MAC CE) at T0, the wireless device may determine (or assume) that the 1st CSI-RSs are transmitted by the base station with the same transmission parameters (e.g., a number of beams, ports, density, bandwidth and etc.) during a time window from T0 to T1, wherein a time offset between T0 and T1 is the time gap. The wireless device may obtain 2nd CSI quantities based on 1st CSI-RS resources, between T0 and T1.
After receiving the DCI (or the MAC CE) at T0, the wireless device may determine (or assume) that the base station switches off 2nd CSI-RS from T1, transmits 3rd CSI-RSs of 1st CSI-RS from T1 and/or changes to new transmission parameters (e.g., ports, density, bandwidth etc.) for CSI-RS resources from T1, wherein a time offset between T0 and T1 is the time gap.
As shown in
By implementing example embodiment of
In an example, a base station may transmit both SSBs and P-CSI-RSs to a wireless device or a group of wireless devices for beam and CSI measurements. In an example, the base station may transmit the SSBs with wider transmission beams, while may transmit the P-CSI-RSs with narrower transmission beams. In an example, the base station may transmit the SSBs with longer transmission periodicity, while may transmit the P-CSI-RSs with shorter transmission periodicity. Transmitting both SSBs and P-CSI-RSs may increase power consumption of the base station, when the base station is in energy saving state. There is a need to improve power consumption for SSB/CSI-RS transmission in energy saving operation.
In the example of
Based on the periodically transmitted SSBs and the P-CSI-RSs, the wireless device may (measure) obtain 1st periodic CSI quantities. The wireless device may transmit 1st CSI report based on the 1st periodic CSI quantities. In an example, the 1st CSI report may comprise a SSB index of a SSB (e.g., with the best RSRP value among RSRP values of the SSBs), a CSI-R resource index of a P-CSI-RS (e.g., with the best RSRP value among RSRP values of the P-CSI-RSs), a RSRP value and/or a differential RSRP value. The wireless device may transmit 1st CSI report via a PUCCH resource configured for the periodic CSI report.
In an example, the base station may transmit, and/or the wireless device may receive, a DCI (and/or a MAC CE) indicating an energy saving for the base station. The DCI indicating the energy saving may be implemented based on example embodiments of
In an example, in response to transmitting the DCI indicating the energy saving, the base station may switch off the periodical transmissions of the P-CSI-RSs (or P-CSI-RS resource sets). In response to transmitting the DCI indicating the energy saving, the base station may keep transmitting the SSBs (or one or more of the SSBs) with the same transmission parameters (e.g., periodicity, number of beams/SSBs, transmission power etc.). In an example, in response to transmitting the DCI indicating the energy saving, the base station may transmit the SSBs (or one or more of the SSBs) with adjusted transmission parameters (e.g., longer periodicity, smaller number of beams/SSBs, reduced transmission power etc.).
In the example of
In an example, based on determining that the P-CSI-RSs are switched off by the base station in the energy saving, the wireless device may obtain (or measure) 2nd periodic CSI quantities based on SSBs only. The wireless device may transmit 2nd periodic CSI report comprising 2nd periodic CSI quantities, to the base station.
In an example, example embodiments of
In response to transmitting the DCI indicating the energy saving, the base station may keep transmitting the SSBs (or one or more of the SSBs) with the same transmission parameters (e.g., periodicity, number of beams/SSBs, transmission power etc.).
In an example, in response to transmitting the DCI indicating the energy saving, the base station may transmit the SSBs (or one or more of the SSBs) with adjusted transmission parameters (e.g., longer periodicity, smaller number of beams/SSBs, reduced transmission power etc.).
In an example, in response to transmitting the DCI indicating the energy saving, the base station may keep transmitting one or more P-CSI-RSs (or resource set(s) of the P-CSI-RSs (or P-CSI-RS resource sets).
In an example, the one or more P-CSI-RSs (or resource set(s)) transmitted by the base station in the energy saving may be configured, by the base station (via RRC messages), from the P-CSI-RSs (or the P-CSI-RS resource sets) configured for the non-energy saving state.
In an example, the one or more P-CSI-RSs (or resource set(s) transmitted by the base station in the energy saving may be predefined (or preconfigured) from the P-CSI-RSs (or the P-CSI-RS resource sets) configured for the non-energy saving state. In this case, the one or more P-CSI-RSs (or resource sets) may be referred to as default P-CSI-RSs (or resource sets). The one or more P-CSI-RSs (or sets) for the energy saving may have a lowest (or highest) RS (or set) index among RS (or set) indexes of the P-CSI-RSs (or sets) configured for the non-energy saving state. The one or more P-CSI-RSs set(s) for the energy saving may be a CSI-RS resource set, among the plurality of CSI-RS resource sets, configured with resource type being set ‘periodic’. The one or more P-CSI-RSs set(s) for the energy saving may be a CSI-RS resource set, among the plurality of CSI-RS resource sets, configured for a primary TRP (or with a CORESET pool index 0) of a plurality of TRPs of the base station. Predefining or preconfiguring default P-CSI-RS(s) or set(s) for energy saving operation may reduce signaling overhead for indicating which P-CSI-RS(s) will be transmitted by the base station in the energy saving operation.
Based on the periodically transmitted SSBs and predefined/preconfigured (default) P-CSI-RSs (or sets) in the energy saving state of the base station, the wireless device may obtain CSI quantities comprising SSB index, CSI-RS resource index and one or more RSRP values. Example embodiments may allow the wireless device to transmit CSI report based on SSBs and CSI-RSs transmitted by the base station in the energy saving operation.
As shown in
In an example embodiment, the BS ES parameters may indicate a search space (e.g., a common search space or a UE-specific search space) for a (group common or UE-specific) DCI indicating the ES (or an energy saving DCI) for the base station. A search space may be implemented based on example embodiments described above with respect to
In an example embodiment, the BS ES parameters may indicate one or more P-SI-RS resources (and/or resource sets) of the ES operation for the base station.
In an example embodiment, the base station may be working in a normal power state (or a non-energy-saving state) during which the base station may transmit downlink signals and receive uplink signals with a normal transmission power (or full transmission power). A wireless device may receive downlink signals and transmit uplink signals with the base station in the normal power state. While the base station is in the normal power state, the wireless device may be indicated to perform one or more power saving operations based on example embodiments described above with respect to
As shown in
Based on the determination of the transition from the normal power state to the energy saving state, the base station may transmit the DCI, in the PDCCH transmission occasion of the search space, indicating that the base station will switch off one or more CSI-RSs from the periodic CSI-RS resources.
In response to receiving the DCI indicating the energy saving for the base station, the wireless device may determine a reduced number (a longer periodicity, a narrower occupied bandwidth, a smaller transmission density and etc.) of periodic CSI-RS resources, e.g., based on example embodiments described above with respect to
Based on example embodiments of
In an example embodiment, when configured with multiple cells (e.g., based on example embodiments described above with respect to
In an example embodiment, a base station may transmit a periodic CSI-RS switching on/off indication for all cells (in active state) jointly. A periodic CSI-RS switching on/off indication, implemented based on example embodiments described above with respect to
In an example embodiment, the base station may transmit separate per-cell periodic CSI-RS switching on/off indication via a cell of a plurality of cells. A per cell periodic CSI-RS switching on/off indication may be applied only on a cell on which the base station transmits the per-cell periodic CSI-RS switching on/off indication. A first periodic CSI-RS switching on/off indication received on a PCell may be applied on the PCell. A second periodic CSI-RS switching on/off indication received on an activated SCell may be applied on the activated SCell, etc.
In an example embodiment, the base station may transmit per cell group periodic CSI-RS switching on/off indication for a group of cells of a plurality of cells. A per cell group periodic CSI-RS switching on/off indication may be applied on a cell group comprising a cell on which the base station transmits the per cell group periodic CSI-RS switching on/off indication. The base station may transmit RRC messages comprising configuration parameters of energy saving operation, wherein the configuration parameters may indicate a plurality of cells are grouped into one or more cell groups.
In an example, the base station may automatically stop transmission of periodic CSI-RSs when the base station determines that there is no active wireless device (e.g., no wireless devices in RRC_CONNECTED state) in the cell. The base station may (automatically) stop transmission of the P-CSI-RSs, without transmitting RRC messages for reconfiguration of the P-CSI-RSs, and/or without transmitting DCI indicating to stop the transmission of the P-CSI-RSs, e.g., in response to determining that there is no active wireless device in a cell. The base station may (automatically) stop transmission of the P-CSI-RSs, without transmitting RRC messages for reconfiguration of the P-CSI-RSs, and/or without transmitting DCI indicating to stop the transmission of the P-CSI-RSs to a wireless device, e.g., in response to determining that the wireless device transitions from RRC_CONNECTED state to RRC_IDLE state or RRC_INACTIVE state. The base station may (automatically) stop transmission of the P-CSI-RSs, without transmitting RRC messages for reconfiguration of the P-CSI-RSs, and/or without transmitting DCI indicating to stop the transmission of the P-CSI-RSs to a wireless device, e.g., in response to receiving an uplink signal, from the wireless device. The uplink signal may indicate that the wireless device has no new data. The uplink signal may indicate a transition of a cell from a non-energy-saving state to an energy saving state. The uplink signal may be a UCI via PUCCH, a MACE CE from the wireless device, a wireless device assistant information in RRC message. Example embodiments may reduce signaling overhead for indication of P-CSI-RS switch off for energy saving of the base station.
In an example, a base station may transmit messages comprising configuration parameters of periodic CSI-RSs resources being grouped to CSI-RS resource sets, wherein each CSI-RS resource set of the CSI-RS resource sets comprises at least one CSI-RS resource of the periodic CSI-RSs resources. The base station may transmit the CSI-RS resource sets in a cell. The base station may transmit a DCI comprising an energy saving indication indicating to switch off a first CSI-RS resource set of the CSI-RS resource sets. The base station may transmit, based on switching off the first CSI-RS resource set, at least a second CSI-RS resource set of the CSI-RS resource sets. In an example, the second CSI-RS resource set is from the CSI-RS resource sets with the first CSI-RS resource set being excluded based on the energy saving indication. In other words, the at least second CSI-RS resource set is not one of the first CSI-RS resource sets switched off.
In an example, a base station may transmit messages comprising configuration parameters of a CSI-RS resource set comprising periodic CSI-RS resources. The base station may transmit the CSI-RS resource set in a cell. The base station may transmit a command comprising an energy saving indication indicating to switch off first CSI-RS resources of the periodic CSI-RS resources of the CSI-RS resource set. The base station may transmit, based on the command and via the cell, at least a second CSI-RS resource of the periodic CSI-RS resources of the CSI-RS resource set. In an example, the second CSI-RS resource set is from the CSI-RS resource sets with the first CSI-RS resource set being excluded based on the energy saving indication. In other words, the at least second CSI-RS resource set is not one of the first CSI-RS resource sets switched off.
In an example, a base station may transmit, RRC messages comprising first parameters of periodic CSI-RS resources. The base station may transmit the periodic CSI-RS resources comprising: first periodic CSI-RS resources and second periodic CSI-RS resources. The base station may transmit a DCI comprising an energy saving indication. In response to the transmitting the DCI, the base state may stop transmissions of the first periodic CSI-RS resources and continue the transmission of the second periodic CSI-RS resources.
In an example, a base station may transmit RRC messages comprising: first parameters of SSBs and second parameters of periodic CSI-RS resources. The base station may transmit the SSBs and the periodic CSI-RS resources. For example, the base station may transmit the SSBs periodically according to a periodicity. The base station may transmit a DCI comprising an energy saving indication. In response to the transmitting the DCI, the base station may continue the transmission of the periodic SSBs and stop periodic transmissions of the periodic CSI-RS resources.
In an example, a wireless device may receive, from a base station, RRC messages comprising configuration parameters of periodic CSI reporting, wherein the configuration parameters comprise first parameters of SSBs and second parameters of periodic CSI-RS resources. The wireless device may receive the SSBs and the periodic CSI-RS resources. The wireless device may transmit, for the periodic CSI reporting, first periodic CSI report based on the SSBs and the periodic CSI-RS resources. The wireless device may receive a DCI comprising an energy saving indication. As discussed above, based on the base station transmitting the DCI with the energy saving indication, the base station may stop transmitting the periodic CSI-RS resources. So, in response to receiving the DCI including the energy saving indication, the wireless device may transmit, for the periodic CSI reporting, second periodic CSI report based on the SSBs (that are periodically received from the base station). Additionally, the second periodic CSI report are not based on (e.g., exclude CSI related measurements of) the periodic CSI RS resources.
In an example, a wireless device may receive, from a base station, RRC messages comprising configuration parameters of periodic CSI reporting, wherein, the configuration parameters comprise parameters of periodic CSI-RS resources and the periodic CSI-RS resources comprise a first periodic CSI-RS resource used for energy saving state. The wireless device may transmit, for the periodic CSI reporting, first periodic CSI report based on receiving the periodic CSI-RS resources. The wireless device may receive a DCI indicating a transition to the energy saving state. For example, the base station may transmit the DCI indicating to transition to the energy saving state in which the base station may stop transmitting periodic CSI-RS resources except the first periodic CSI-RS resource. Based on receiving the DCI indicating to transition to the energy saving state, the wireless device may stop receiving the periodic CSI-RS resources except the first periodic CSI-RS resource. The wireless device may transmit, for the periodic CSI reporting, second periodic CSI report based on the first periodic CSI-RS resource of the periodic CSI-RS resources. Additionally, the second periodic CSI report are not based on (e.g., exclude CSI related measurements of) other periodic CSI-RS resources of the periodic CSI-RS resources.
According to an example embodiment, each CSI-RS resource of the CSI-RES resource set is associated with one or more parameters comprising at least one of: a CSI-RS resource index identifying the CSI-RS resource, parameters of time and frequency resources for mapping the CSI-RS resource, one or more power control parameters, a scrambling identifier, a periodicity and offset indicator and a quasi-correction information indication. The parameters of time and frequency resources for mapping the CSI-RS resource comprise at least one of: indications of one or more subcarriers of a resource block (RB) for the CSI-RS resource, indication of a number of ports for the CSI-RS, indication of first (starting) OFDM symbol in a slot for the CSI-RS resource, a code-division multiplexing (CDM) type indication, a density indication and a frequency band indication. The frequency band indication indicates: a starting RB of a plurality of RBs, of a bandwidth part, for the CSI-RS resource, and a number of the plurality RBs for the CSI-RS resource.
According to an example embodiment, the CSI-RS resource set is associated with one or more parameters comprising at least one of: a CSI-RS resource set identifier identifying the CSI-RS resource set, CSI-RS resource indexes identifying the CSI-RS resources, and a repetition indicator.
According to an example embodiment, the base station may skip, based on the command, a transmission of the first CSI-RS resources of the CSI-RS resource set on the cell.
According to an example embodiment, the command comprises at least one of: DCI, MAC CE and/or RRC message.
According to an example embodiment, the DCI is different from at least one of: DCI format 2_0 for indication of slot format, available RB sets, COT duration and search space set group switching, DCI format 2_1 for indication of downlink pre-emption, DCI format 2_4 for indication of uplink cancellation and DCI format 2_6 for indication of power saving information outside DRX Active time for one or more wireless devices.
According to an example embodiment, the DCI has a same DCI size with at least one of: the DCI format 2_0, the DCI format 2_1, DCI format 2_4 for indication of uplink cancellation, DCI format 2_6 for indication of power saving information outside DRX Active time for one or more wireless devices.
According to an example embodiment, the DCI is with a DCI format comprising a bitmap, wherein each bit of the bitmap corresponds to a respective CSI-RS resource of the CSI-RS resources of the CSI-RS resource set and a bit of the bitmap indicates whether to switch off a corresponding CSI-RS resource of the CSI-RS resources of the CSI-RS resource set.
According to an example embodiment, the DCI is with a DCI format comprising a bit field indicating a CSI-RS switching on/off pattern of a plurality of CSI-RS switching on/off patterns. The plurality of CSI-RS switching on/off patterns comprise a first CSI-RS switching on/off pattern wherein CSI-RS resources with even CSI-RS indexes, of the CSI-RS resources in the CSI-RS resource set, are switched on for transmissions in slots with even slot number and CSI-RS resources with odd CSI-RS indexes, of the CSI-RS resources in the CSI-RS resource set, are switched off for transmissions in the slots with even slot number. The plurality of CSI-RS switching on/off patterns comprise a second CSI-RS switching on/off pattern wherein CSI-RS resources with even CSI-RS indexes, of the CSI-RS resources in the CSI-RS resource set, are switched off for transmission in slots with even slot number and CSI-RS resources with odd CSI-RS indexes, of the CSI-RS resources in the CSI-RS resource set, are switched on for transmissions in the slots with even slot number.
According to an example embodiment, the transmitting the CSI-RS resource set comprises transmitting the CSI-RS resources comprised in the CSI-RS resource set. The transmitting the CSI-RS resources, in response to a repetition indicator of the CSI-RS resource set being set to a first value, comprises transmitting a first CSI-RS resources, of the CSI-RS resources, with a first transmission spatial domain filter and transmitting a first CSI-RS resources, of the CSI-RS resources, with a second transmission spatial domain filter. The first transmission spatial domain filter is different from the second transmission spatial domain filter. The transmitting the CSI-RS resources, in response to a repetition indicator of the CSI-RS resource set being set to a second value, comprises transmitting a first CSI-RS resources, of the CSI-RS resources, with a transmission spatial domain filter and transmitting a first CSI-RS resources, of the CSI-RS resources, with the same transmission spatial domain filter.
According to an example embodiment, the base station transmits the DCI via a second cell. The second cell is a primary cell. In an example, the second cell is a secondary cell.
According to an example embodiment, the base station transmits the DCI via the cell. The cell is a primary cell of a plurality of cells comprising one or more secondary cells.
According to an example embodiment, the base station may receive, from a wireless device, a wireless device assistance information indicating a transition of the base station from a non-energy-saving state to an energy saving state. The base station transmits the DCI based on receiving the wireless device assistance information. The wireless device assistance information is a second RRC message transmitted from the wireless device to the base station. The wireless device assistance information is an uplink control information (UCI) transmitted via a physical uplink channel (PUCCH and/or PUSCH) to the base station.
According to an example embodiment, the messages comprise RRC message and/or SIB1 message.
According to an example embodiment, the base station transmits the CSI-RS resources with a first transmission periodicity based on the base station being in a non-energy-saving state. The non-energy-saving state comprises a time duration when the base station transmits downlink signals with a first transmission power and a first number of beams and receives uplink signals. The downlink signals comprise at least one of: SSBs/SIBs/PDSCH/PDCCH/CSI-RS/DM-RS. The uplink signals comprise at least one of: CSI reports/PUSCH/PUCCH/SRS/RACH.
According to an example embodiment, the energy saving indication indicates a transition of the base station from the non-energy-saving state to an energy saving state. The configuration parameters indicate the at least second CSI-RS resource, of the CSI-RS resources of the CSI-RS resource set, for transmission in the energy saving state. The at least second CSI-RS resource may have a lowest CSI-RS index among CSI-RS indexes of the CSI-RS resources of the CSI-RS resource set. The at least second CSI-RS resource may have a longest transmission periodicity among transmission periodicities of the CSI-RS resources of the CSI-RS resource set. The at least second CSI-RS resource may have a smallest transmission density among transmission densities of the CSI-RS resources of the CSI-RS resource set. The at least second CSI-RS resource may have a smallest transmission bandwidth among transmission bandwidths of the CSI-RS resources of the CSI-RS resource set. The configuration parameters indicate the first CSI-RS resources, of the CSI-RS resources of the CSI-RS resource set, for switching off transmission in the energy saving state.
According to an example embodiment, the energy saving state may comprise a second time duration when the base station transmits the downlink signals with a second transmission power, wherein the second transmission power is less than the first transmission power. The energy saving state may comprise a second time duration when the base station transmits the downlink signals with a second number of beams, wherein the second number is smaller than the first number. The energy saving state may comprise a second time duration when the base station stops the receiving uplink signals.
According to an example embodiment, the base station may transition from the non-energy-saving state to the energy saving state based on the transmitting the DCI.
According to an example embodiment, the messages further comprise configuration parameters of a search space for transmitting the DCI comprising the energy saving indication. The search space may be a type 0 common search space, wherein the configuration parameters is comprised in master information block (MIB) message, wherein the base station transmits the MIB message via a physical broadcast channel (PBCH) and indicating system information of the base station. The search space may be a type 0 common search space, wherein the configuration parameters is comprised in system information block 1 (SIB1) message, wherein the base station transmits the SIB1 message, scheduled by a physical downlink control channel, indicating at least one of: information for evaluating if a wireless device is allowed to access a cell of the base station, information for scheduling of other system information, radio resource configuration information that is common for all wireless devices and barring information applied to access control. The search space may be a type 2 common search space, wherein the type 2 common search space is further used for downlink paging message transmission. The search space may be a type 3 common search space, wherein the type 3 common search space is further used for transmission, via a cell, of a second group common DCI with CRC bits scrambled by at least one of: INT-RNTI/SFI-RNTI/CI-RNTI/TPC-PUSCH-RNTI/TPC-PUCCH-RNTI/TPC-SRS-RNTI. In response to the cell being a primary cell of a plurality of cells of the base station, the type 3 common search space is further used for transmission of a second group common DCI with CRC bits scrambled by at least one of: PS-RNTI/C-RNTI/MCS-C-RNTI/CS-RNTI.
According to an example embodiment, the configuration parameters comprise a RNTI for a transmission of the DCI comprising the energy saving indication, wherein the DCI is a group common DCI. The base station may transmit the DCI comprising the energy saving indication based on CRC bits of the DCI being scrambled by the RNTI.
According to an example embodiment, the DCI may have a same DCI format as a DCI format 1_0.
According to an example embodiment, the RNTI associated with the DCI is different from a C-RNTI identifying a specific wireless device.
According to an example embodiment, the DCI may have a same DCI format as at least one of: DCI format 2_0 for indication of slot format, available resource block (RB) sets, channel occupancy time (COT) duration and search space set group switching, DCI format 2_1 for indication of downlink pre-emption, DCI format 2_4 for indication of uplink cancellation and DCI format 2_6 for indication of power saving information outside DRX Active time for one or more wireless devices.
According to an example embodiment, the RNTI associated with the DCI may be different from: a slot format indication RNTI (SFI-RNTI) associated with the DCI format 2_0, an interruption RNTI (INT_RNTI) associated with DCI format 2_1, a cancellation RNTI (CI-RNTI) associated with the DCI format 2_4 and a power saving RNTI (PS-RNTI) associated with the DCI format 2_6.
According to an example embodiment, the configuration parameters may comprise a PDCCH monitoring periodicity value for the search space, wherein the PDCCH monitoring periodicity value indicates a number of slots between two contiguous transmissions of two DCIs for the energy saving indication. The base station may transmit the DCI at a beginning slot of the number of slots. The DCI may comprise a DCI field indicating a second transmission periodicity of the CSI resource set. The DCI field may indicate a ratio between the second transmission periodicity and the first transmission periodicity.
According to an example embodiment, the base station transmits the command at a first slot. The base station may switch off, based on transmitting the command at the first slot, the first CSI-RS resources at a second slot, wherein a time gap between the first slot and the second slot is greater than a time threshold for an application of a transition from the non-energy-saving state to the energy saving state. The time threshold may be configured in the messages. The wireless device may transmit to the base station, a RRC message indicating the time threshold. The RRC message may comprise a wireless device capability information comprising the time threshold. The RRC message may comprise a wireless device assistance information comprising the time threshold.
This application is a continuation of International Application No. PCT/US2023/017459, filed Apr. 4, 2023, which claims the benefit of U.S. Provisional Application No. 63/331,470, filed Apr. 15, 2022, all of which are hereby incorporated by reference in their entireties.
Number | Date | Country | |
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63331470 | Apr 2022 | US |
Number | Date | Country | |
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Parent | PCT/US2023/017459 | Apr 2023 | WO |
Child | 18667698 | US |