Method and apparatus for small data transmission (SDT)

Abstract

A wireless device receives a radio resource control (RRC) release message from a base station, the radio resource control release message including: a measurement configuration for performing one or more measurements by the wireless device while the wireless device is in an RRC inactive state; and a small data transfer (SDT) configuration for transmitting an SDT procedure by the wireless device while the wireless device is in the RRC inactive state. When the wireless device is in the RRC inactive state based on the RRC release message, the wireless device initiates the SDT procedure based on the SDT configuration and does not perform measurements associated with the measurement configuration during the SDT procedure.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 226,882, filed on July 29, 2021, the entire contents of which are hereby incorporated by reference. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Examples of several of the various embodiments of the present disclosure are described herein with reference to the accompanying drawings.

[0004] Figure 1A and Figure 1B An exemplary mobile communications network is shown in which embodiments of the present disclosure may be implemented.

[0005] Figure 2A and Figure 2B The New Radio (NR) user plane and control plane protocol stacks are shown separately.

[0006] Figure 3 Shown in Figure 2A Examples of services provided between the protocol layers of the NR user plane protocol stack.

[0007] Figure 4A Shows the flow Figure 2A Example downlink data flow of the NR user plane protocol stack.

[0008] Figure 4B An exemplary format of a MAC subheader in a MAC PDU is shown.

[0009] Figure 5A and Figure 5B The mapping between logical channels, transport channels and physical channels is shown for downlink and uplink respectively.

[0010] Figure 6 is an example diagram showing RRC state transition of a UE.

[0011] Figure 7 An exemplary configuration of an NR frame into which OFDM symbols are grouped is shown.

[0012] Figure 8 An exemplary configuration of time slots in the time and frequency domains of an NR carrier is shown.

[0013] Figure 9 An example of bandwidth adaptation using three configured BWPs for NR carriers is shown.

[0014] Figure 10A Three carrier aggregation configurations with two component carriers are shown.

[0015] Figure 10B An example is shown of how aggregated cells may be configured into one or more PUCCH groups.

[0016] Figure 11A An example of SS / PBCH block structure and location is shown.

[0017] Figure 11B An example of CSI-RS mapped in the time and frequency domains is shown.

[0018] Figure 12A and Figure 12B Three examples of downlink and uplink beam management procedures are shown respectively.

[0019] Figure 13A 、 Figure 13B and Figure 13C A four-step contention-based random access procedure, a two-step contention-free random access procedure, and another two-step random access procedure are shown respectively.

[0020] Figure 14A An example of a CORESET configuration for the bandwidth portion is shown.

[0021] Figure 14B An example of CCE to REG mapping for DCI transmission on CORESET and PDCCH processing is shown.

[0022] Figure 15 An example of a wireless device communicating with a base station is shown.

[0023] Figure 16A 、 Figure 16B 、 Figure 16C and Figure 16D Exemplary structures for uplink and downlink transmissions are shown.

[0024] Figure 17 An example of an RRC connection re-establishment procedure is shown.

[0025] Figure 18 An example of an RRC connection recovery procedure is shown.

[0026] Figure 19 An example of the latter small data transfer (SDT) is shown.

[0027] Figure 20A An example of time window management for one or more subsequent transmissions of an SDT is shown.

[0028] Figure 20B An example of time window management for one or more subsequent transmissions of an SDT is shown.

[0029] Figure 21An example of idle / inactivity measurement utilizing the SDT procedure is shown.

[0030] Figure 22 An example of utilizing the SDT process to manage idle / inactive measurements is shown.

[0031] Figure 23 An example of using a timer to manage idle / inactive measurements based on an SDT procedure is shown.

[0032] Figure 24 An example of utilizing idle / inactivity measurements to detect failure of the SDT process is shown.

[0033] Figure 25 An example of utilizing the SDT process to manage idle / inactive measurements is shown.

[0034] Figure 26 An example of using a timer to manage idle / inactive measurements with the SDT procedure is shown. DETAILED DESCRIPTION

[0035] In the present disclosure, various embodiments are presented in the form of examples of how the disclosed technology can be implemented and / or how the disclosed technology can be practiced in environments and scenarios. It will be apparent to those skilled in the relevant art that various changes in form and detail can be made therein without departing from the scope of the present invention. In fact, after reading the specification, it will be apparent to those skilled in the relevant art how to implement alternative embodiments. The embodiments of the present invention should not be limited by any described exemplary embodiments. The embodiments of the present disclosure will be described with reference to the accompanying drawings. The limitations, features and / or elements from the disclosed exemplary embodiments can be combined to create additional embodiments within the scope of the present disclosure. Any figures that highlight functionality and advantages are provided for illustrative purposes only. The disclosed architecture is flexible and configurable enough that it can be utilized in a manner different from that shown. For example, the actions listed in any flow chart can be reordered or only optionally used in certain embodiments.

[0036] Implementations can be configured to operate as desired. For example, the disclosed mechanisms can be implemented when certain criteria are met in a wireless device, base station, radio environment, network, or combinations thereof. Exemplary criteria can be based, at least in part, on, for example, wireless device or network node configuration, traffic load, initial system setup, packet size, traffic characteristics, or combinations thereof. When one or more criteria are met, various exemplary implementations can be applied. Thus, exemplary implementations that selectively implement the disclosed protocol can be implemented.

[0037] A base station may communicate with a mixture of wireless devices. A wireless device and / or base station may support multiple technologies and / or multiple versions of the same technology. A wireless device may have certain specific capabilities, depending on the wireless device class and / or capabilities. When the present disclosure refers to a base station communicating with multiple wireless devices, the present disclosure may refer to a subset of the total wireless devices in the coverage area. For example, the present disclosure may refer to multiple wireless devices of a given LTE or 5G version with given capabilities and in a given sector of a base station. The multiple wireless devices in the present disclosure may refer to a selected plurality of wireless devices, and / or a subset of the total wireless devices in the coverage area that perform according to the disclosed methods, etc. There may be multiple base stations or multiple wireless devices in the coverage area that may not comply with the disclosed methods, for example, these wireless devices or base stations may perform based on older versions of LTE or 5G technology.

[0038] In this disclosure, "a" and "an" and similar phrases will be interpreted as "at least one" and "one or more". Similarly, any term ending with the suffix "(s)" will 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" indicates that the phrase following the term "may" is an example of one suitable possibility among multiple suitable possibilities that may or may not be used for one or more embodiments in various embodiments. As used herein, the terms "comprising" and "consisting of" list one or more components of the element being described. The terms "comprising" and "including" are interchangeable and do not exclude that unlisted components are included in the element being described. In contrast, "consisting of" provides a complete listing of the one or more components of the element being described. As used herein, the term "based on" should be interpreted as "based at least in part on" rather than, for example, "based only on". As used herein, the term "and / or" represents any possible combination of the listed elements. For example, "A, B and / or C" can mean A; B; C; A and B; A and C; B and C; or A, B and C.

[0039] If A and B are sets, and every element of A is also an element of B, then A is called a subset of B. In this specification, only non-empty sets and subsets are considered. For example, the possible subsets of B = {cell1, cell2} are: {cell1}, {cell2}, and {cell1, cell2}. The phrase "based on" (or equivalently, "based at least on") indicates that the phrase following the term "based on" is an example of one of multiple suitable possibilities that may or may not be used in one or more different embodiments. The phrase "in response to" (or equivalently, "in response to at least") indicates that the phrase following the phrase "in response to" is an example of one of multiple suitable possibilities that may or may not be used in one or more different embodiments. The phrase "depending on" (or equivalently, "depending on at least") indicates that the phrase following the phrase "depending on" is an example of one of multiple suitable possibilities that may or may not be used in one or more different embodiments. The phrase "using / adopting" (or equivalently, "at least adopting / adopting") indicates that the phrase following the phrase "adopting / adopting" is an example of one of multiple suitable possibilities that may or may not be used in one or more different embodiments.

[0040] The term "configured" can refer to the capabilities of a device, whether the device is in an operational or non-operational state. "Configured" can also refer to specific settings in a device that affect the operational characteristics of the device, whether the device is in an operational or non-operational state. In other words, hardware, software, firmware, registers, memory values, etc. can be "configured" within a device to provide specific characteristics to the device, whether the device is in an operational or non-operational state. Terms such as "a control message induced in a device" can mean that the control message has parameters that can be used to configure specific characteristics in the device or parameters that can be used to implement certain actions in the device, whether the device is in an operational or non-operational state.

[0041] In the present disclosure, a parameter (or equivalently referred to as a field or information element: IE) may include one or more information objects, and an information object may include one or more other objects. For example, if parameter (IE) N includes parameter (IE) M, and parameter (IE) M includes parameter (IE) K, and parameter (IE) K includes parameter (information element) J. Then, for example, N includes K, and N includes J. In an exemplary embodiment, when one or more messages include multiple parameters, it means that the parameters of the multiple parameters are in at least one of the one or more messages, but not necessarily in every one of the one or more messages.

[0042] Many of the features presented are described as optional, either by using the word "may" or by using parentheses. For the sake of brevity and readability, this disclosure does not explicitly recite every permutation that can be obtained by selecting from the set of optional features. This disclosure should be interpreted as explicitly disclosing all such permutations. For example, a system described as having three optional features can be embodied in seven different ways, namely, having only one of the three possible features, having any two of the three possible features, or having three of the three possible features.

[0043] Many elements described in the disclosed embodiments can be implemented as modules. Modules are defined here as elements that perform defined functions and have defined interfaces to other elements. The modules described in this disclosure can be implemented with hardware, software, firmware, wetware (e.g., hardware with biological elements) or a combination thereof in conjunction with hardware, all of which can be equivalent in behavior. For example, a module can be implemented as a software routine written in a computer language that is configured to be executed by a hardware machine (such as, C, C++, Fortran, Java, Basic, Matlab, etc.) or a modeling / simulation program (such as, Simulink, Stateflow, GNU Octave, or LabVIEW MathScript). It is possible to implement a module using physical hardware that incorporates discrete or programmable analog, digital, and / or quantum hardware. Examples of programmable hardware include: 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++, etc. FPGAs, ASICs, and CPLDs are often programmed using a hardware description language (HDL), such as VHSIC Hardware Description Language (VHDL) or Verilog, which configures the connections between the smaller internal hardware blocks on the programmable device. The mentioned techniques are often used in combination to achieve the results of the functional blocks.

[0044] Figure 1A 1 shows an example of a mobile communication network 100 in which embodiments of the present disclosure may be implemented. The mobile communication network 100 may be, for example, a public land mobile network (PLMN) operated by a network operator. Figure 1A As shown, mobile communication network 100 includes a core network (CN) 102 , a radio access network (RAN) 104 , and wireless devices 106 .

[0045] The CN 102 may provide an interface to one or more data networks (DNs), such as public DNs (e.g., the Internet), private DNs, and / or intra-carrier DNs, for the wireless device 106. As part of the interface functionality, the CN 102 may set up an end-to-end connection between the wireless device 106 and the one or more DNs, authenticate the wireless device 106, and provide charging functionality.

[0046] The RAN 104 can connect the CN 102 to the wireless device 106 via radio communication over an air interface. As part of the radio communication, the RAN 104 can provide scheduling, radio resource management, and retransmission protocols. The direction of communication from the RAN 104 to the wireless device 106 over the air interface is referred to as downlink, while the direction of communication from the wireless device 106 to the RAN 104 over the air interface is referred to as uplink. Downlink transmissions can be separated from uplink transmissions using frequency division duplexing (FDD), time division duplexing (TDD), and / or some combination of the two duplexing techniques.

[0047] The term "wireless device" may be used throughout this disclosure to refer to and encompass any mobile or fixed (non-mobile) device that requires or can use wireless communication. For example, a wireless device can be a phone, a smartphone, a tablet, a computer, a laptop, a sensor, a meter, a wearable device, an Internet of Things (IoT) device, a vehicle roadside unit (RSU), a relay node, an automobile, and / or any combination thereof. The term "wireless device" encompasses other terms including user equipment (UE), user terminal (UT), access terminal (AT), mobile station, handset, wireless transmit and receive unit (WTRU), and / or wireless communication device.

[0048] 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 forwarder 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 include at least one gNB central unit (gNB-CU) and at least one gNB distributed unit (gNB-DU).

[0049] The base stations included in the RAN 104 may include one or more sets of antennas for communicating with the wireless devices 106 over the air interface. For example, one or more of the base stations may include three sets of antennas to control three cells (or sectors) respectively. The size of a cell may be determined by the range at which a receiver (e.g., a base station receiver) can successfully receive 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 devices 106 over a wide geographic area to support wireless device mobility.

[0050] In addition to three-sector sites, other implementations of the base station are possible. For example, one or more of the base stations in the RAN 104 may be implemented as a sectorized 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, a baseband processing unit coupled to several remote radio heads (RRHs), and / or a repeater or relay node for extending the coverage area of ​​a donor node. The baseband processing units coupled to the RRHs may be part of a centralized or cloud RAN architecture, where the baseband processing units may be centralized in a pool of baseband processing units or virtualized. The repeater node may amplify and rebroadcast the radio signal received from the donor node. The relay node may perform the same / similar functions as the repeater node, but may decode the radio signal received from the donor node to remove noise before amplifying and rebroadcasting the radio signal.

[0051] The RAN 104 can be deployed as a homogeneous network of macrocell base stations with similar antenna types and similar high-level transmit power. The RAN 104 can also be deployed as a heterogeneous network. In a heterogeneous network, small cell base stations can be used to provide small coverage areas, such as coverage areas that overlap with the relatively larger coverage area provided by macrocell base stations. Small coverage areas can be provided in areas with high data traffic (or so-called "hotspots") or in areas where macrocell coverage is weak. Examples of small cell base stations include, in descending order of coverage area: microcell base stations, picocell base stations, and femtocell base stations or home base stations.

[0052] The Third Generation Partnership Project (3GPP) was established in 1998 to Figure 1A 100 in the mobile communication network 100. To date, 3GPP has developed specifications for three generations of mobile networks: the third generation (3G) network known as the Universal Mobile Telecommunications System (UMTS), the fourth generation (4G) network known as the Long Term Evolution (LTE), and the fifth generation (5G) network known as the 5G System (5GS). The embodiments of the present disclosure are described with reference to the RAN of the 3GPP 5G network known as the Next Generation RAN (NG-RAN). These embodiments are applicable to the RAN of other mobile communication networks, such as Figure 1A The RAN 104 in 5G networks, the RANs of earlier 3G and 4G networks, and those of yet-to-be-specified future networks (e.g., 3GPP 6G networks). The NG-RAN implements the 5G radio access technology known as New Radio (NR) and may be configured to implement 4G radio access technology or other radio access technologies, including non-3GPP radio access technologies.

[0053] Figure 1B Another exemplary mobile communication network 150 is shown in which embodiments of the present disclosure may be implemented. The mobile communication network 150 may be, for example, a PLMN operated by a network operator. Figure 1B As shown in FIG, a mobile communication network 150 includes a 5G core network (5G-CN) 152, an NG-RAN 154, and UEs 156A and 156B (collectively referred to as UE 156). Figure 1A The corresponding components described herein are implemented and operate in the same or similar manner.

[0054] 5G-CN 152 provides an interface to one or more DNs, such as a public DN (e.g., the Internet), a private DN, and / or an operator's internal DN, to the UE 156. As part of the interface functionality, the 5G-CN 152 may set up an end-to-end connection between the UE 156 and the one or more DNs, authenticate the UE 156, and provide charging functionality. Compared to the CN of the 3GPP 4G network, the basis of the 5G-CN 152 may be a service-based architecture. This means that the architecture of the nodes that make up the 5G-CN 152 may be defined as network functions that provide services to other network functions via interfaces. 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).

[0055] like Figure 1B As shown, 5G-CN 152 includes an access and mobility management function (AMF) 158A and a user plane function (UPF) 158B. Figure 1BIn the figure, they are shown as one component AMF / UPF 158. UPF 158B can act as a gateway between NG-RAN 154 and the one or more DNs. UPF 158B can perform functions such as: packet routing and forwarding, packet inspection and user plane policy rule enforcement, service usage reporting, uplink classification to support routing of service flows to the one or more DNs, user plane quality of service (QoS) processing (e.g., packet filtering, gating, uplink / downlink rate enforcement and uplink service verification), downlink packet buffering and downlink data notification triggering. UPF 158B can act as an anchor point for intra / inter-radio access technology (RAT) mobility, an external protocol (or packet) data unit (PDU) session point interconnected with the one or more DNs and / or a fulcrum to support multi-homed PDU sessions. UE 156 can be configured to receive services through a PDU session, which is a logical connection between the UE and the DN.

[0056] 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 retransmissions), registration area management, intra-system and inter-system mobility support, access authentication, access authorization including roaming rights verification, mobility management control (subscription and policy), network slicing support and / or session management function (SMF) selection. NAS may refer to a function operating between the CN and the UE, and AS may refer to a function operating between the UE and the RAN.

[0057] 5G-CN 152 may include Figure 1B For example, the 5G-CN 152 may include one or more of the following: a session management function (SMF), an NR repository function (NRF), a policy control function (PCF), a network exposure function (NEF), a unified data management (UDM), an application function (AF), and / or an authentication server function (AUSF).

[0058] The NG-RAN 154 can connect the 5G-CN 152 to the UE 156 via radio communications over the air interface. The NG-RAN 154 may include one or more gNBs, shown as gNB 160A and gNB 160B (collectively, gNB 160), and / or one or more ng-eNBs, shown as ng-eNB 162A and ng-eNB 162B (collectively, ng-eNB 162). The gNBs 160 and ng-eNB 162 may be more generally referred to as base stations. The gNBs 160 and ng-eNB 162 may include one or more antennas for communicating with the UE 156 over the air interface. For example, one or more gNBs in gNB 160 and / or one or more ng-eNBs in ng-eNB 162 may include three antennas to control three cells (or sectors), respectively. The cells of gNB 160 and ng-eNB 162 may together provide radio coverage to UE 156 over a wide geographic area to support UE mobility.

[0059] like Figure 1B As shown in FIG, gNB 160 and / or ng-eNB 162 may be connected to 5G-CN 152 via an NG interface and to other base stations via an Xn interface. The NG and Xn interfaces may be established using direct physical connections and / or indirect connections through an underlying transport network, such as an Internet Protocol (IP) transport network. gNB 160 and / or ng-eNB 162 may be connected to UE 156 via a Uu interface. For example, Figure 1B As shown in FIG, gNB 160A can be connected to UE 156A via a Uu interface. The NG, Xn, and Uu interfaces are associated with a protocol stack. The protocol stack associated with the interface can be composed of Figure 1B Network elements in a network exchange data and signaling messages and may include two planes: the user plane and the control plane. The user plane processes data of interest to users, while the control plane processes signaling messages of interest to network elements.

[0060] The gNB 160 and / or ng-eNB 162 may be connected to one or more AMF / UPF functions of the 5G-CN 152, such as the AMF / UPF 158, via one or more NG interfaces. For example, the gNB 160A may be connected to the UPF 158B of the AMF / UPF 158 via an NG user plane (NG-U) interface. The NG-U interface may provide for delivery of user plane PDUs (e.g., non-guaranteed delivery) between the gNB 160A and the UPF 158B. The gNB 160A may be connected to the AMF 158A via an NG control plane (NG-C) interface. The NG-C interface may provide, for example, NG interface management, UE context management, UE mobility management, delivery of NAS messages, paging, PDU session management, and configuration delivery and / or warning message transmission.

[0061] The gNB 160 can provide NR user plane and control plane protocol termination to the UE 156 via a Uu interface. For example, the gNB 160A can provide NR user plane and control plane protocol termination to the UE 156A via a Uu interface associated with the first protocol stack. The ng-eNB 162 can provide Evolved UMTS Terrestrial Radio Access (E-UTRA) user plane and control plane protocol termination to the UE 156 via a Uu interface, where E-UTRA refers to a 3GPP 4G radio access technology. For example, the ng-eNB 162B can provide E-UTRA user plane and control plane protocol termination to the UE 156B via a Uu interface associated with the second protocol stack.

[0062] The 5G-CN 152 is described as being configured to handle both NR and 4G radio access. One of ordinary skill in the art will appreciate that it is possible for NR to be connected to a 4G core network in a mode known as "non-standalone operation." In non-standalone operation, the 4G core network is used to provide (or at least support) control plane functions (e.g., initial access, mobility, and paging). Although Figure 1B Only one AMF / UPF 158 is shown in the figure, but one gNB or ng-eNB can be connected to multiple AMF / UPF nodes to provide redundancy and / or load sharing across the multiple AMF / UPF nodes.

[0063] As discussed, Figure 1B The interfaces between network elements in a network (e.g., Uu, Xn, and NG interfaces) can be associated with a protocol stack used by the network elements to exchange data and signaling messages. The protocol stack can include two planes: the user plane and the control plane. The user plane can handle data of interest to users, while the control plane can handle signaling messages of interest to network elements.

[0064] Figure 2A and Figure 2B Examples of NR user plane and NR control plane protocol stacks for the Uu interface between UE 210 and gNB 220 are shown, respectively. Figure 2A and Figure 2B The protocol stack shown in can be used with e.g. Figure 1B The protocol stacks of the Uu interface between UE 156A and gNB 160A shown in FIG are the same or similar.

[0065] Figure 2A The NR user plane protocol stack is shown, including five layers implemented in UE 210 and gNB 220. At the bottom of the protocol stack, physical layers (PHY) 211 and 221 can provide transport services to higher layers of the protocol stack and can correspond to layer 1 of the open systems interconnection (OSI) model. The next four protocols above PHY 211 and 221 include medium access control layer (MAC) 212 and 222, radio link control layer (RLC) 213 and 223, packet data convergence protocol layer (PDCP) 214 and 224, and service data application protocol layer (SDAP) 215 and 225. Together, these four protocols can constitute layer 2, or the data link layer, of the OSI model.

[0066] Figure 3 An example of services provided between protocol layers of the NR user plane protocol stack is shown. Figure 2A and Figure 3 Starting from the top, SDAPs 215 and 225 can perform QoS flow processing. UE 210 can receive services via a PDU session, which can be a logical connection between UE 210 and a DN. A PDU session can have one or more QoS flows. The UPF of the CN (e.g., UPF 158B) can map IP packets to the one or more QoS flows of the PDU session based on QoS requirements (e.g., in terms of latency, data rate, and / or error rate). SDAPs 215 and 225 can perform mapping / demapping between the one or more QoS flows and one or more data radio bearers. The mapping / demapping between QoS flows and data radio bearers can be determined by SDAP 225 at gNB 220. SDAP 215 at UE 210 can learn the mapping between QoS flows and data radio bearers through reflective mapping or control signaling received from gNB 220. For reflective mapping, the SDAP 225 at the gNB 220 may mark downlink packets with a QoS flow indicator (QFI), which may be observed by the SDAP 215 at the UE 210 to determine the mapping / de-mapping between QoS flows and data radio bearers.

[0067] PDCPs 214 and 224 can perform header compression / decompression to reduce the amount of data transmitted over the air interface, encryption / decryption to prevent unauthorized decoding of data transmitted over the air interface, and integrity protection to ensure that control messages originate from the intended source. PDCPs 214 and 224 can also perform retransmission of undelivered packets, in-sequence delivery and reordering of packets, and removal of duplicate packets received due to, for example, intra-gNB handovers. PDCPs 214 and 224 can also perform packet duplication to increase the likelihood of packet reception and remove any duplicate packets at the receiver. Packet duplication can be suitable for services requiring high reliability.

[0068] although Figure 3 Not shown, but PDCP 214 and 224 can perform mapping / demapping between split radio bearers and RLC channels in dual connectivity scenarios. Dual connectivity is a technology that allows a UE to connect to two cells or more generally to two cell groups: a primary cell group (MCG) and a secondary cell group (SCG). Split bearers are split bearers when a single radio bearer (such as one of the radio bearers provided by PDCP 214 and 224 as a service to SDAP 215 and 225) is handled by a cell group in dual connectivity. PDCP 214 and 224 can map / demapped split radio bearers between RLC channels belonging to a cell group.

[0069] RLC 213 and 223 can perform segmentation, retransmission via automatic repeat request (ARQ), and removal of duplicate data units received from MAC 212 and 222, respectively. RLC 213 and 223 can support three transmission modes: transparent mode (TM); unacknowledged mode (UM); and acknowledged mode (AM). Based on the transmission mode in which the RLC is operating, the RLC can perform one or more of the functions described. RLC configuration can be on a per-logical channel basis, independent of parameter sets and / or transmission time interval (TTI) durations. Figure 3 As shown in FIG, RLC 213 and 223 may provide RLC channels as services to PDCP 214 and 224, respectively.

[0070] MACs 212 and 222 may perform multiplexing / demultiplexing of logical channels and / or mapping between logical channels and transport channels. Multiplexing / demultiplexing may include multiplexing / demultiplexing data units belonging to one or more logical channels into / from transport blocks (TBs) delivered to / from PHYs 211 and 221. MAC 222 may be configured to perform scheduling, scheduling information reporting, and priority handling between UEs using dynamic scheduling. Scheduling may be performed in gNB 220 (at MAC 222) for both downlink and uplink. MACs 212 and 222 may be configured to perform error correction using hybrid automatic repeat request (HARQ) (e.g., one HARQ entity per carrier in the case of carrier aggregation (CA)), priority handling between logical channels of UE 210 using logical channel prioritization, and / or padding. MACs 212 and 222 may support one or more parameter sets and / or transmission timing. In an example, mapping restrictions in logical channel prioritization can control which parameter sets and / or transmission timings a logical channel can use. Figure 3 As shown, MAC 212 and 222 may provide logical channels as a service to RLC 213 and 223 .

[0071] PHY 211 and 221 can 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, encoding / decoding and modulation / demodulation. PHY 211 and 221 can perform multi-antenna mapping. Figure 3 As shown in , PHYs 211 and 221 may provide one or more transport channels as a service to MACs 212 and 222 .

[0072] Figure 4A An exemplary downlink data flow through the NR user plane protocol stack is shown. Figure 4A The figure shows the downlink data flow of three IP packets (n, n+1, and m) flowing through the NR user plane protocol stack to generate two TBs at the gNB 220. The uplink data flow flowing through the NR user plane protocol stack can be the same as Figure 4A The downlink data flow is similar to that depicted in .

[0073] Figure 4A The downlink data flow starts when the SDAP 225 receives three IP packets from one or more QoS flows and maps the three packets to a radio bearer. Figure 4A In the SDAP header (in Figure 4AThe data unit from / to the higher protocol layer is called the service data unit (SDU) of the lower protocol layer, and the data unit to / from the lower protocol layer is called the protocol data unit (PDU) of the higher protocol layer. Figure 4A As shown in , the data units from SDAP 225 are SDUs of the lower protocol layer PDCP 224 and are PDUs of SDAP 225 .

[0074] Figure 4A The remaining protocol layers in the Figure 3 ), add the corresponding headers and forward their corresponding output to the next lower layer. For example, PDCP 224 may perform IP header compression and encryption and forward its output to RLC 223. RLC 223 may optionally perform segmentation (e.g., Figure 4A 2) and forwards its output to the MAC 222. The MAC 222 may multiplex many RLC PDUs and may append MAC subheaders to the RLC PDUs to form a transport block. In NR, MAC subheaders may be distributed throughout the MAC PDUs, as shown in FIG. Figure 4A In LTE, the MAC subheader can be located entirely at the beginning of the MAC PDU. The NR MAC PDU structure can reduce processing time and associated latency because the MAC PDU subheader can be calculated before assembling the complete MAC PDU.

[0075] Figure 4B An exemplary format of a MAC subheader in a MAC PDU is shown. The MAC subheader includes: an SDU length field for indicating the length (e.g., in bytes) of the MAC SDU to which the MAC subheader corresponds; a logical channel identifier (LCID) field for identifying the logical channel from which the MAC SDU originates to assist in the demultiplexing process; a flag (F) for indicating the size of the SDU length field; and a reserved bit (R) field for future use.

[0076] Figure 4B Further shown is a MAC Control Element (CE) inserted into the MAC PDU by a MAC, such as MAC 223 or MAC 222. For example, Figure 4B Two MAC CEs are shown inserted into the MAC PDU. Figure 4B) and a MAC CE is inserted at the end of a MAC PDU for uplink transmission. MAC CE may be used for in-band control signaling. Example MAC CEs include: scheduling-related MAC CEs, such as buffer status reporting and power headroom reporting; activation / deactivation MAC CEs, such as those used for PDCP duplicate detection, channel state information (CSI) reporting, sounding reference signal (SRS) transmission, and activation / deactivation of previously configured components; discontinuous reception (DRX)-related MAC CEs; timing advance MAC CEs; and random access-related MAC CEs. The MAC CE may be preceded by a MAC subheader having a format similar to that described with respect to the MAC SDU, and the MAC CE may be identified with a reserved value in the LCID field that indicates the type of control information included in the MAC CE.

[0077] Before describing the NR control plane protocol stack, we first describe the mapping between logical channels, transport channels, and physical channels, as well as channel types. One or more of these channels can be used to perform functions associated with the NR control plane protocol stack described later below.

[0078] Figure 5A and Figure 5B The mapping between logical channels, transport channels and physical channels is shown for downlink and uplink respectively. Information is passed through channels between RLC, MAC and PHY of the NR protocol stack. Logical channels can be used between RLC and MAC and can be classified as control channels that carry control and configuration information in the NR control plane, or as traffic channels that carry data in the NR user plane. Logical channels can be classified as dedicated logical channels dedicated to a specific UE, or as common logical channels that can be used by more than one UE. Logical channels can also be defined by the type of information they carry. The set of logical channels defined by NR includes, for example:

[0079] - Paging Control Channel (PCCH), which is used to carry paging messages for UEs whose locations are unknown to the network at the cell level;

[0080] - Broadcast Control Channel (BCCH), which is used to carry system information messages in the form of a Master Information Block (MIB) and several System Information Blocks (SIBs), which can be used by UEs to obtain information about how a cell is configured and how it operates within the cell;

[0081] - Common Control Channel (CCCH), which is used to carry control messages and random access;

[0082] - a dedicated control channel (DCCH), which is used to carry control messages to / from a specific UE to configure the UE; and

[0083] - Dedicated Traffic Channel (DTCH), which is used to carry user data to / from a specific UE.

[0084] Transport channels are used between the MAC layer and the PHY layer and can be defined by how the information they carry is transmitted over the air interface. The set of transport channels defined by NR includes, for example:

[0085] - Paging Channel (PCH), which is used to carry paging messages originating from PCCH;

[0086] - Broadcast Channel (BCH), which is used to carry the MIB from the BCCH;

[0087] - Downlink Shared Channel (DL-SCH), which is used to carry downlink data and signaling messages, including SIBs from BCCH;

[0088] - Uplink Shared Channel (UL-SCH), which is used to carry uplink data and signaling messages; and

[0089] - Random Access Channel (RACH), which is used to allow a UE to contact the network without any previous scheduling.

[0090] The PHY may use physical channels to pass information between processing levels of the PHY. A physical channel may have a set of associated time-frequency resources for carrying information for one or more transport channels. The PHY may generate control information to support the low-level operation of the PHY and provide control information to the lower levels of the PHY via physical control channels (referred to as L1 / L2 control channels). The set of physical channels and physical control channels defined by NR includes, for example:

[0091] - Physical Broadcast Channel (PBCH), which is used to carry the MIB from the BCH;

[0092] - Physical Downlink Shared Channel (PDSCH), which is used to carry downlink data and signaling messages from DL-SCH and paging messages from PCH;

[0093] - Physical Downlink Control Channel (PDCCH), which is used to carry downlink control information (DCI), which may include downlink scheduling commands, uplink scheduling grants, and uplink power control commands;

[0094] - Physical Uplink Shared Channel (PUSCH), which is used to carry uplink data and signaling messages from the UL-SCH, and in some cases uplink control information (UCI) as described below;

[0095] - Physical Uplink Control Channel (PUCCH), which is used to carry UCI, which may include HARQ acknowledgment, channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI), and scheduling request (SR); and

[0096] - Physical Random Access Channel (PRACH), which is used for random access.

[0097] Similar to the physical control channel, the physical layer generates physical signals to support the low-level operations of the physical layer. Figure 5A and Figure 5B As shown in [1], the physical layer signals defined by NR include: Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), Channel State Information Reference Signal (CSI-RS), Demodulation Reference Signal (DMRS), Sounding Reference Signal (SRS), and Phase Tracking Reference Signal (PT-RS). These physical layer signals will be described in more detail below.

[0098] Figure 2B An exemplary NR control plane protocol stack is shown. Figure 2B As shown in FIG, the NR control plane protocol stack may use the same / similar first four protocol layers as the exemplary NR user plane protocol stack. These four protocol layers include PHY 211 and 221, MAC 212 and 222, RLC 213 and 223, and PDCP 214 and 224. Instead of having SDAP 215 and 225 at the top of the stack as in the NR user plane protocol stack, the NR control plane protocol stack instead has radio resource control (RRC) 216 and 226 and NAS protocols 217 and 237 at the top of the NR control plane protocol stack.

[0099] The NAS protocols 217 and 237 may provide control plane functionality between the UE 210 and the AMF 230 (e.g., 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 known as NAS messages. There is no direct path between the UE 210 and the AMF 230 through which NAS messages may be transmitted. NAS messages may be transmitted using the AS of the Uu and NG interfaces. The NAS protocols 217 and 237 may provide control plane functionality such as authentication, security, connection setup, mobility management, and session management.

[0100] RRCs 216 and 226 may provide control plane functionality between UE 210 and gNB 220, or more generally, between UE 210 and the RAN. RRCs 216 and 226 may provide control plane functionality between UE 210 and gNB 220 via signaling messages, referred to as RRC messages. RRC messages may be transported between UE 210 and the RAN using signaling radio bearers and the same / similar PDCP, RLC, MAC, and PHY protocol layers. MAC may multiplex control plane and user plane data into the same transport block (TB). The RRC 216 and 226 may provide control plane functions such as: broadcast of system information related to the AS and NAS; paging initiated by the CN or 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; UE measurement reporting and control of the reporting; detection of radio link failure (RLF) and recovery from radio link failure; and / or NAS messaging. As part of establishing an RRC connection, the RRC 216 and 226 may establish an RRC context, which may involve configuring parameters for communication between the UE 210 and the RAN.

[0101] Figure 6 is an example diagram showing the RRC state transition of the UE. The UE can Figure 1A The wireless device 106 depicted in Figure 2A and Figure 2B The UE 210 depicted in FIG or any other wireless device described in this disclosure is the same or similar. Figure 6 As shown in FIG, a UE may be in at least one of three RRC states: RRC connected 602 (eg, RRC_CONNECTED), RRC idle 604 (eg, RRC_IDLE), and RRC inactive 606 (eg, RRC_INACTIVE).

[0102] In RRC connection 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 following: Figure 1A The one or more base stations included in the RAN 104 depicted in FIG; Figure 1B One of the gNB 160 or ng-eNB 162 depicted in FIG; Figure 2A and Figure 2Bor any other base station described in the present disclosure. A base station connected to a UE may have an RRC context for the UE. The RRC context, referred to as the UE context, may include parameters used for communication between the UE and the base station. These parameters may include, for example: one or more AS contexts; one or more radio link configuration parameters; bearer configuration information (e.g., relating to data radio bearers, signaling radio bearers, logical channels, QoS flows, and / or PDU sessions); security information; and / or PHY, MAC, RLC, PDCP, and / or SDAP layer configuration information. While in RRC connection 602, the UE's mobility may be managed by the RAN (e.g., RAN 104 or NG-RAN 154). The UE may measure signal levels (e.g., reference signal levels) from a serving cell and neighboring cells and report these measurements to the base station currently serving the UE. The UE's serving base station may request handover to a cell of one of the neighboring base stations based on the reported measurements. The RRC state may transition from RRC connected 602 to RRC idle 604 through a connection release procedure 608 , or to RRC inactive 606 through a connection deactivation procedure 610 .

[0103] 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 a base station. While in RRC Idle 604, the UE may be in a sleep state most of the time (e.g., to conserve battery power). The UE may periodically wake up (e.g., once per discontinuous reception cycle) to monitor for paging messages from the RAN. The UE's mobility may be managed by the UE through a process 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 more detail below.

[0104] In RRC Inactive 606, the previously established RRC context is maintained in the UE and the base station. This allows for a quick transition to RRC Connected 602 with reduced signaling overhead 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 the UE's mobility may be managed by the UE through cell reselection. The RRC state may transition from RRC Inactive 606 to RRC Connected 602 via a Connection Resumption Procedure 614, or to RRC Idle 604 via a Connection Release Procedure 616, which may be the same as or similar to the Connection Release Procedure 608.

[0105] The RRC state can be associated with mobility management mechanisms. 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 notify the UE of events via paging messages without having to broadcast paging messages across the entire mobile communications network. The mobility management mechanisms used in RRC Idle 604 and RRC Inactive 606 can allow the network to track the UE at a cell group level, so that paging messages can be broadcast to cells in the cell group in which the UE is currently residing, rather than across the entire mobile communications network. The mobility management mechanisms used in RRC Idle 604 and RRC Inactive 606 track the UE at a cell group level. These mobility management mechanisms can do so using groupings of different granularities. For example, there can 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, known as tracking areas and identified by a Tracking Area Identifier (TAI).

[0106] Tracking areas can be used to track UEs at the CN level. The CN (e.g., CN 102 or 5G-CN 152) can provide the UE with a list of TAIs associated with the UE's registration area. If the UE moves to a cell associated with a TAI that is not included in the list of TAIs associated with the UE's registration area through cell reselection, the UE can perform a registration update on the CN to allow the CN to update the UE's location and provide the UE with a new UE registration area.

[0107] RAN areas can be used to track UEs at the RAN level. For a UE in the RRC Inactive 606 state, a RAN notification area can be assigned to the UE. The RAN notification area can include one or more cell identifiers, a list of RAIs, or a list of TAIs. In an example, a base station can belong to one or more RAN notification areas. In an example, a cell can belong to one or more RAN notification areas. If a UE moves to a cell not included in the RAN notification area assigned to the UE through cell reselection, the UE can perform a notification area update on the RAN to update the UE's RAN notification area.

[0108] The base station that stores the RRC context for the UE or the last serving base station of the UE may be referred to as the anchor base station. The anchor base station may maintain the RRC context for the UE at least for the period of time that the UE remains in the RAN notification area of ​​the anchor base station and / or for the period of time that the UE remains in RRC inactivity 606.

[0109] gNBs, such as Figure 1BThe gNB 160 in the LTE-M protocol can be divided into two parts: a central unit (gNB-CU) and one or more distributed units (gNB-DUs). The gNB-CU can be coupled to one or more gNB-DUs using the F1 interface. The gNB-CU can include RRC, PDCP, and SDAP. The gNB-DU can include RLC, MAC, and PHY.

[0110] In NR, physical signals and physical channels (about Figure 5A and Figure 5B Discussed) can be mapped onto orthogonal frequency division multiplexing (OFDM) symbols. OFDM is a multi-carrier communication scheme that transmits data over F orthogonal subcarriers (or tones). Before transmission, the data can be mapped to a series of complex symbols called source symbols (e.g., M-quadrature amplitude modulation (M-QAM) symbols or M-phase shift keying (M-PSK) symbols) and divided into F parallel symbol streams. The F parallel symbol streams can be treated as if they were in the frequency domain and used as input to an inverse fast Fourier transform (IFFT) block that transforms them into the time domain. The IFFT block can take F source symbols at a time (one source symbol from each of the F parallel symbol streams) and use each source symbol to modulate the amplitude and phase of one of the F sinusoidal basis functions corresponding to the F orthogonal subcarriers. The output of the IFFT block can be F time domain samples representing the sum of the F orthogonal subcarriers. The F time domain samples can form a single OFDM symbol. After some processing (e.g., addition of a cyclic prefix) and up-conversion, the OFDM symbols provided by the IFFT block can be transmitted over the air interface at the carrier frequency. The F parallel symbol streams can be mixed using the FFT block before being processed by the IFFT block. This operation produces discrete Fourier transform (DFT) precoded OFDM symbols and can be used by the UE in the uplink to reduce the peak-to-average power ratio (PAPR). The FFT block can be used to perform inverse processing on the OFDM symbols at the receiver to restore the data mapped to the source symbols.

[0111] Figure 7 An exemplary configuration of an NR frame into which OFDM symbols are grouped is shown. An NR frame may be identified by a system frame number (SFN). The SFN may repeat with a period of 1024 frames. As shown, an NR frame may have a duration of 10 milliseconds (ms) and may include 10 subframes of 1 ms duration. A subframe may be divided into time slots, which may include, for example, 14 OFDM symbols per time slot.

[0112] The duration of a timeslot may depend on the parameter set used for the OFDM symbol for that timeslot. In NR, flexible parameter sets are supported to accommodate different cell deployments (e.g., cells with carrier frequencies below 1 GHz, up to cells with carrier frequencies in the mmWave range). Parameter sets may be defined in terms of subcarrier spacing and cyclic prefix duration. For parameter sets in NR, the subcarrier spacing may be scaled up by powers of two from a baseline subcarrier spacing of 15 kHz, and the cyclic prefix duration may be scaled down by powers of two from a baseline cyclic prefix duration of 4.7 μs. For example, NR defines parameter sets 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.

[0113] A slot may have a fixed number of OFDM symbols (eg, 14 OFDM symbols). Parameter sets with higher subcarrier spacing have shorter slot durations and correspondingly more slots per subframe. Figure 7 The transmission structure of the time slot duration and time slot per subframe associated with the parameter set is shown (for ease of illustration, Figure 7 (The numerology with 240 kHz subcarrier spacing is not shown in the figure). The subframe in NR can be used as a time reference independent of the numerology, while the slot can be used as the unit for scheduling uplink and downlink transmissions. To support low latency, scheduling in NR can be decoupled from the slot duration and start at any OFDM symbol and continue for as many symbols as needed. These partial slot transmissions can be called mini-slots or sub-slot transmissions.

[0114] Figure 8 An exemplary configuration of a time slot in the time and frequency domains of an NR carrier is shown. The time slot includes a resource element (RE) and a resource block (RB). RE is the smallest physical resource in NR. RE spans one OFDM symbol in the time domain through one subcarrier in the frequency domain, as shown in FIG. Figure 8 As shown in . RB spans twelve consecutive REs in the frequency domain, as Figure 8 As shown. The NR carrier can be limited to a width of 275RBs or 275×12=3300 subcarriers. If this restriction is used, the NR carrier can be limited to 50MHz, 100MHz, 200MHz and 400MHz for subcarrier spacing of 15kHz, 30kHz, 60kHz and 120kHz, respectively, where the 400MHz bandwidth can be set based on the 400MHz bandwidth limit per carrier.

[0115] Figure 8A single parameter set is shown used across the entire bandwidth of the NR carrier. In other example configurations, multiple parameter sets may be supported on the same carrier.

[0116] NR can support wide carrier bandwidths (e.g., up to 400 MHz for a 120 kHz subcarrier spacing). Not all UEs may be able to receive the full carrier bandwidth (e.g., due to hardware limitations). Moreover, 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, the UE can adapt the size of the UE's receive bandwidth based on the amount of traffic the UE plans to receive. This is called bandwidth adaptation.

[0117] NR defines bandwidth parts (BWPs) to support UEs that cannot receive the full carrier bandwidth and to support bandwidth adaptation. In an example, a BWP can be defined by a subset of contiguous RBs on a carrier. The UE can be configured (e.g., via the 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 can be active. The one or more BWPs can be referred to as the active BWPs of the serving cell. When a serving cell is configured with a secondary uplink carrier, the serving cell can have one or more first active BWPs in the uplink carrier and one or more second active BWPs in the secondary uplink carrier.

[0118] For unpaired spectrum, a downlink BWP from the set of configured downlink BWPs may be linked with an uplink BWP from the set of configured uplink BWPs if the downlink BWP index of the downlink BWP is the same as the uplink BWP index of the uplink BWP. For unpaired spectrum, the UE may expect the center frequency of the downlink BWP to be the same as the center frequency of the uplink BWP.

[0119] For a downlink BWP in the set of configured downlink BWPs on a primary cell (PCell), the base station can configure the 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 domain where a UE can search for control information. A search space can be a UE-specific search space or a common search space (potentially usable by multiple UEs). For example, the base station can configure a common search space for a UE on a PCell or a primary / secondary cell (PSCell) in an active downlink BWP.

[0120] For an uplink BWP in the set of configured uplink BWPs, the BS may configure one or more resource sets for the UE for one or more PUCCH transmissions. The UE may receive downlink transmissions (e.g., PDCCH or PDSCH) in the downlink BWP based on the configured parameter set for the downlink BWP (e.g., subcarrier spacing and cyclic prefix duration). The UE may transmit uplink transmissions (e.g., PUCCH or PUSCH) in the uplink BWP based on the configured parameter set (e.g., subcarrier spacing and cyclic prefix length of the uplink BWP).

[0121] One or more BWP indicator fields may be provided in downlink control information (DCI). The value of the BWP indicator field may indicate which BWP in a set of configured BWPs is the active downlink BWP for one or more downlink receptions. The value of the one or more BWP indicator fields may indicate the active uplink BWP for one or more uplink transmissions.

[0122] The base station may semi-statically configure a default downlink BWP for the UE within the set of configured downlink BWPs associated with the PCell. If the base station does not provide a default downlink BWP to the UE, the default downlink BWP may be the initial active downlink BWP. The UE may determine which BWP is the initial active downlink BWP based on the CORESET configuration obtained using the PBCH.

[0123] The base station may configure the BWP inactivity timer value for the PCell for the UE. The UE may start or restart the BWP inactivity timer at any appropriate time. For example, the UE may start or restart the BWP inactivity timer in the following circumstances: (a) when the UE detects a DCI indicating an active downlink BWP other than the default downlink BWP for paired spectrum operation; or (b) when the UE detects a DCI indicating an active downlink BWP or an active uplink BWP other than the default downlink BWP or uplink BWP for unpaired spectrum operation. If the UE does not detect the DCI within a time interval (e.g., 1 ms or 0.5 ms), the UE may run the BWP inactivity timer towards expiration (e.g., incrementing the BWP inactivity timer value from zero to, or decrementing the BWP inactivity timer value from zero). When the BWP inactivity timer expires, the UE may switch from the active downlink BWP to the default downlink BWP.

[0124] In an example, the base station may semi-statically configure the UE with one or more BWPs. The UE may switch the active BWP from the first BWP to the second BWP in response to receiving a DCI indicating that the second BWP is the active BWP and / or in response to expiration of a BWP inactivity timer (e.g., when the second BWP is the default BWP).

[0125] Downlink and uplink BWP switching can be performed independently in paired spectrum (where BWP switching refers to switching from the currently active BWP to the non-currently active BWP). In unpaired spectrum, downlink and uplink BWP switching can be performed simultaneously. Switching between configured BWPs can occur based on RRC signaling, DCI, expiration of the BWP inactivity timer, and / or initiation of random access.

[0126] Figure 9 An example of bandwidth adaptation using three configured BWPs of an NR carrier is shown. A UE configured with these three BWPs can switch from one BWP to another at a switching point. Figure 9 In the example shown, the BWPs include: BWP 902, which has a bandwidth of 40 MHz and a subcarrier spacing of 15 kHz; BWP 904, which has a bandwidth of 10 MHz and a subcarrier spacing of 15 kHz; and BWP 906, which has a bandwidth of 20 MHz and a subcarrier spacing of 60 kHz. BWP 902 may be the initial active BWP, and BWP 904 may be the default BWP. The UE may switch between BWPs at a switching point. Figure 9 In the example shown in FIG. 1 , the UE may switch from BWP 902 to BWP 904 at switch point 908. The switch at switch point 908 may occur for any suitable reason, such as in response to expiration of a BWP inactivity timer (indicating a switch to a default BWP) and / or in response to receiving a DCI indicating that BWP 904 is the active BWP. The UE may switch from active BWP 904 to BWP 906 at switch point 910 in response to receiving a DCI indicating that BWP 906 is the active BWP. The UE may switch from active BWP 906 to BWP 904 at switch point 912 in response to expiration of a BWP inactivity timer and / or in response to receiving a DCI indicating that BWP 904 is the active BWP. The UE may switch from active BWP 904 to BWP 902 at switch point 914 in response to receiving a DCI indicating that BWP 902 is the active BWP.

[0127] If the UE is configured for a secondary cell with a default downlink BWP and timer values ​​from the set of configured downlink BWPs, the UE procedures for switching the BWP on the secondary cell may be the same / similar to those on the primary cell. For example, the UE may use the timer values ​​and default downlink BWP for the secondary cell in the same / similar manner as the UE would use these values ​​for the primary cell.

[0128] To provide higher data rates, carrier aggregation (CA) can be used to aggregate two or more carriers and transmit them simultaneously to / from the same UE. The aggregated carriers in CA may be referred to as component carriers (CCs). When CA is used, there are many serving cells for the UE, one for each CC. CCs can have three configurations in the frequency domain.

[0129] Figure 10A Three CA configurations with two CCs are shown. In the intra-band contiguous configuration 1002, the two CCs are aggregated in the same frequency band (Band A) and located directly adjacent to each other within the band. In the intra-band non-contiguous configuration 1004, the two CCs are aggregated in the same frequency band (Band A) and separated by a gap within the band. In the inter-band configuration 1006, the two CCs are located in frequency bands (Band A and Band B).

[0130] In an example, up to 32 CCs can be aggregated. Aggregated CCs can have the same or different bandwidths, subcarrier spacing, and / or duplexing schemes (TDD or FDD). A serving cell for a UE using CA can have downlink CCs. For FDD, one or more uplink CCs can optionally be configured for the serving cell. For example, when a UE has more data traffic in the downlink than in the uplink, the ability to aggregate more downlink carriers than uplink carriers can be useful.

[0131] 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 to which the UE initially connects at RRC connection establishment, reestablishment, and / or handover. The PCell may provide NAS mobility information and security input to the UE. The UE may have different PCells. In the downlink, the carrier corresponding to the PCell may be referred to as a downlink primary CC (DL PCC). In the uplink, the carrier corresponding to the PCell may be referred to as an uplink primary CC (UL PCC). Other aggregated cells for the UE may be referred to as secondary cells (SCells). In an example, the SCell may be configured after the PCell is configured for the UE. For example, the SCell may be configured through an RRC connection reconfiguration procedure. In the downlink, the carrier corresponding to the 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 an uplink secondary CC (UL SCC).

[0132] The configured SCell for a UE can be activated and deactivated based on, for example, traffic and channel conditions. Deactivation of an SCell can mean stopping PDCCH and PDSCH reception on the SCell, and stopping PUSCH, SRS, and CQI transmission on the SCell. Figure 4B The configured SCells may be activated and deactivated using a MAC CE. For example, the MAC CE may use a bitmap (e.g., one bit per SCell) to indicate which SCells (e.g., a subset of configured SCells) are activated or deactivated for the UE. The configured SCells may be deactivated in response to the expiration of an SCell deactivation timer (e.g., one SCell deactivation timer per SCell).

[0133] The downlink control information of a cell (such as scheduling assignments and scheduling grants) can be transmitted on the cell corresponding to the assignment and grant, which is called self-scheduling. The DCI of a cell can be transmitted on another cell, which is called cross-carrier scheduling. The uplink control information for the aggregated cell (e.g., HARQ confirmation and channel state feedback, such as CQI, PMI and / or RI) can be transmitted on the PUCCH of the PCell. For a large number of aggregated downlink CCs, the PUCCH of the PCell may become overloaded. The cell can be divided into multiple PUCCH groups.

[0134] Figure 10B An example of how aggregated cells can be configured into one or more PUCCH groups is shown. PUCCH group 1010 and PUCCH group 1050 may each include one or more downlink CCs. Figure 10BIn the example of FIG, PUCCH group 1010 includes three downlink CCs: PCell 1011, SCell 1012, and SCell 1013. PUCCH group 1050 in this example includes three downlink CCs: PCell 1051, SCell 1052, and SCell 1053. One or more uplink CCs may be configured as PCell 1021, SCell 1022, and SCell 1023. One or more other uplink CCs may be configured as primary SCell (PSCell) 1061, SCell 1062, and SCell 1063. Uplink control information (UCI) related to the downlink CCs of PUCCH group 1010 (shown as UCI 1031, UCI 1032, and UCI 1033) may be transmitted in the uplink of PCell 1021. Uplink control information (UCI) related to the downlink CCs of PUCCH group 1050 (shown as UCI 1071, UCI 1072, and UCI 1073) may be transmitted in the uplink of PSCell 1061. In this example, if Figure 10B If the aggregated cell depicted in FIG is not divided into PUCCH group 1010 and PUCCH group 1050, a single uplink PCell transmits UCI associated with the downlink CC, and the PCell may become overloaded. Overload can be prevented by dividing the transmission of UCI between PCell 1021 and PSCell 1061.

[0135] A physical cell ID and a cell index may be assigned to a cell comprising a downlink carrier and an optional uplink carrier. The physical cell ID or cell index may identify the downlink carrier and / or uplink carrier of the cell, for example, depending on the context in which the physical cell ID is used. The physical cell ID may be determined using a synchronization signal transmitted on a downlink component carrier. The cell index may be determined using an RRC message. In the present disclosure, the physical cell ID may be referred to as a carrier ID, and the cell index may be referred to as a carrier index. For example, when the present disclosure relates to a first physical cell ID of a first downlink carrier, the present disclosure may mean that the first physical cell ID is used for a cell comprising the first downlink carrier. The same / similar concepts may apply, for example, to carrier activation. When the present disclosure indicates that a first carrier is activated, the present specification may mean that a cell comprising the first carrier is activated.

[0136] In carrier aggregation, the multi-carrier nature of the PHY can be exposed to the MAC. In this example, the HARQ entity can operate on the serving cell. A transport block can be generated based on the assignment / grant of each serving cell. The transport block and potential HARQ retransmissions of the transport block can be mapped to the serving cell.

[0137] In the downlink, the base station may transmit (e.g., unicast, multicast, and / or broadcast) one or more reference signals (RS) to the UE (e.g., PSS, SSS, CSI-RS, DMRS, and / or PT-RS, such as Figure 5A In the uplink, the UE may transmit one or more RSs to the base station (e.g., DMRS, PT-RS, and / or SRS, as shown in FIG. Figure 5B (as shown). The PSS and SSS may be transmitted by a base station and used by a UE to synchronize the UE with the base station. The PSS and SSS may be provided in a synchronization signal (SS) / physical broadcast channel (PBCH) block that includes the PSS, SSS, and PBCH. The base station may periodically transmit bursts of SS / PBCH blocks.

[0138] Figure 11A An example of the structure and location of SS / PBCH blocks is shown. A burst of SS / PBCH blocks may include one or more SS / PBCH blocks (e.g., 4 SS / PBCH blocks, such as Figure 11A As shown). Bursts may be transmitted periodically (e.g., every 2 frames or 20 ms). Bursts may be limited to half a frame (e.g., the first half frame having a duration of 5 ms). It will be understood that Figure 11A are examples, and these parameters (number of SS / PBCH blocks per burst, periodicity of the burst, position of the burst within the frame) may be configured based on, for example: the carrier frequency of the cell in which the SS / PBCH blocks are transmitted; the parameter set or subcarrier spacing of the cell; configuration by the network (e.g., using RRC signaling); or any other suitable factor. In an example, the UE may assume the subcarrier spacing of the SS / PBCH blocks based on the carrier frequency being monitored unless the radio network configures the UE to assume a different subcarrier spacing.

[0139] SS / PBCH blocks may span one or more OFDM symbols in the time domain (e.g., 4 OFDM symbols, e.g., Figure 11A ) and may span one or more subcarriers in the frequency domain (e.g., 240 consecutive subcarriers). The PSS, SSS, and PBCH may have a common center frequency. The PSS may be transmitted first and may span, for example, 1 OFDM symbol and 127 subcarriers. The SSS may be transmitted after the PSS (e.g., two symbols later) and may span 1 OFDM symbol and 127 subcarriers. The PBCH may be transmitted after the PSS (e.g., spanning the next 3 OFDM symbols) and may span 240 subcarriers.

[0140] The UE may not know the location of the SS / PBCH blocks in the time and frequency domains (for example, when the UE is searching for cells). In order to find and select a cell, the UE may monitor the carrier of the PSS. For example, the UE may monitor the frequency position within the carrier. If no PSS is found after a certain duration (for example, 20ms), the UE may search for the PSS at different frequency positions within the carrier, as indicated by the synchronization raster. If the PSS is found at a certain position in the time and frequency domains, the UE may determine the location of the SSS and PBCH based on the known structure of the SS / PBCH block, respectively. The SS / PBCH block may be a cell definition SS block (CD-SSB). In an example, the primary cell may be associated with the CD-SSB. The CD-SSB may be located on the synchronization raster. In an example, cell selection / search and / or reselection may be based on the CD-SSB.

[0141] The SS / PBCH block can be used by the UE to determine one or more parameters of the cell. For example, the UE can determine the physical cell identifier (PCI) of the cell based on the sequence of the PSS and SSS, respectively. The UE can determine the location of the cell's frame boundary based on the location of the SS / PBCH block. For example, the SS / PBCH block can indicate that it has been transmitted according to a transmission pattern in which the SS / PBCH block is a known distance from the frame boundary.

[0142] The PBCH may use QPSK modulation and forward error correction (FEC). FEC may use polarity coding. One or more symbols spanned by the PBCH may carry one or more DMRS for demodulating the PBCH. The PBCH may include an indication of the current system frame number (SFN) of the cell and / or an SS / PBCH block timing index. These parameters may facilitate time synchronization between the UE and the base station. The PBCH may include a master information block (MIB) for providing one or more parameters to the UE. The MIB may be used by the UE to locate the remaining minimum system information (RMSI) associated with the cell. The RMSI may include a system information block type 1 (SIB1). SIB1 may contain information required for the UE to access the cell. The UE may use one or more parameters of the MIB to monitor the PDCCH that may be used to schedule the PDSCH. The PDSCH may include SIB1. SIB1 may be decoded using the parameters provided in the MIB. The PBCH may indicate that SIB1 does not exist. Based on the PBCH indicating that SIB1 does not exist, the UE may point to a frequency. The UE may search for SS / PBCH blocks at the frequency to which the UE is pointed.

[0143] The UE may assume that one or more SS / PBCH blocks transmitted with the 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 blocks transmitted with different SS / PBCH block indices.

[0144] SS / PBCH blocks (e.g., those within a half-frame) may be transmitted in spatial directions (e.g., using different beams across the 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.

[0145] In an example, a base station may transmit multiple SS / PBCH blocks within a frequency range of a carrier. In an example, a first PCI of a first SS / PBCH block in the multiple SS / PBCH blocks may be different from a second PCI of a second SS / PBCH block in the multiple SS / PBCH blocks. The PCIs of SS / PBCH blocks transmitted in different frequency locations may be different or the same.

[0146] The CSI-RS may be transmitted by a base station and used by a UE to obtain channel state information (CSI). The base station may configure the UE with one or more CSI-RS for channel estimation or any other suitable purpose. The base station may configure the UE with one or more of the same / similar CSI-RS. The UE may measure the one or more CSI-RS. The UE may estimate the downlink channel state and / or generate a CSI report based on the measurement of the one or more downlink CSI-RS. The UE may provide the CSI report to the base station. The base station may use the feedback provided by the UE (e.g., the estimated downlink channel state) to perform link adaptation.

[0147] The base station can semi-statically configure the UE with one or more CSI-RS resource sets. CSI-RS resources can be associated with a location in the time and frequency domains, as well as a periodicity. The base station can selectively activate and / or deactivate CSI-RS resources. The base station can indicate to the UE that CSI-RS resources in a CSI-RS resource set are activated and / or deactivated.

[0148] The base station can configure the UE to report CSI measurement values. The base station can configure the UE to provide CSI reports periodically, aperiodically, or semi-persistently. For periodic CSI reporting, the UE can be configured with the timing and / or period of multiple CSI reports. For aperiodic CSI reporting, the base station can request a CSI report. For example, the base station can command the UE to measure the configured CSI-RS resources and provide a CSI report related to the measurement value. For semi-persistent CSI reporting, the base station can configure the UE to transmit periodically and selectively activate or deactivate periodic reporting. The base station can configure the UE with a CSI-RS resource set and CSI reporting using RRC signaling.

[0149] The CSI-RS configuration may include one or more parameters indicating, for example, up to 32 antenna ports. The UE may be configured to use the same OFDM symbol for the downlink CSI-RS and control resource set (CORESET) when the downlink CSI-RS and CORESET are spatially QCLed and the resource elements associated with the downlink CSI-RS are outside the physical resource blocks (PRBs) configured for the CORESET. The UE may be configured to use the same OFDM symbol for the downlink CSI-RS and SS / PBCH blocks when the downlink CSI-RS and SS / PBCH blocks are spatially QCLed and the resource elements associated with the downlink CSI-RS are outside the PRBs configured for the SS / PBCH blocks.

[0150] Downlink DMRS can be transmitted by the base station and used by the UE for channel estimation. For example, the downlink DMRS can be used for consistent demodulation of one or more downlink physical channels (e.g., PDSCH). The NR network can support one or more variable and / or configurable DMRS patterns for data demodulation. At least one downlink DMRS configuration can support a frontload DMRS pattern. The frontload DMRS can be mapped on one or more OFDM symbols (e.g., one or two adjacent OFDM symbols). The base station can semi-statically configure the UE with the number (e.g., maximum number) of frontload DMRS symbols for PDSCH. The DMRS configuration can support one or more DMRS ports. For example, for single-user MIMO, the DMRS configuration can support up to eight orthogonal downlink DMRS ports per UE. For multi-user MIMO, the DMRS configuration can support up to four orthogonal downlink DMRS ports per UE. The radio network can (e.g., at least for CP-OFDM) support a common DMRS structure for downlink and uplink, where the DMRS position, DMRS pattern and / or scrambling sequence can be the same or different. The base station may use the same precoding matrix to transmit the downlink DMRS and the corresponding PDSCH. The UE may use the one or more downlink DMRSs to perform consistent demodulation / channel estimation on the PDSCH.

[0151] In an example, a transmitter (e.g., a base station) may use a precoder matrix for a portion of the 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 the same precoding matrix is ​​used across a set of PRBs. The set of PRBs may be denoted as a precoding resource block group (PRG).

[0152] The PDSCH may include one or more layers. The UE may assume that at least one symbol with DMRS is present on a layer in the one or more layers of the PDSCH. Higher layers may configure up to three DMRS for the PDSCH.

[0153] The downlink PT-RS may be transmitted by the base station and used by the UE for phase noise compensation. The presence or absence of the downlink PT-RS may depend on the RRC configuration. The presence and / or type of the downlink PT-RS may be configured on a UE-specific basis using a combination of RRC signaling and / or association with one or more parameters that may be indicated by the DCI for other purposes (e.g., modulation and coding scheme (MCS)). When configured, the dynamic presence of the downlink PT-RS may be associated with one or more DCI parameters including at least the MCS. NR networks may support multiple PT-RS densities defined in the time / frequency domain. When present, the frequency domain density may be associated with at least one configuration of the scheduled bandwidth. The UE may use the same precoding for both DMRS ports and PT-RS ports. The number of PT-RS ports may be less than the number of DMRS ports in the scheduled resources. The downlink PT-RS may be restricted to the scheduled time / frequency duration of the UE. The downlink PT-RS may be transmitted on a symbol to facilitate phase tracking at the receiver.

[0154] The UE may transmit an uplink DMRS to the base station for channel estimation. For example, the base station may use the uplink DMRS to uniformly demodulate 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 frequency range similar to the frequency range 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 frontload DMRS pattern. The frontload DMRS may be mapped on one or more OFDM symbols (e.g., one or two adjacent OFDM symbols). One or more uplink DMRS may be configured to be transmitted at one or more symbols of the PUSCH and / or PUCCH. The base station may semi-statically configure the UE with the number (e.g., maximum number) of frontload DMRS symbols for the PUSCH and / or PUCCH, and the UE may use the frontload DMRS symbols to schedule single-symbol DMRS and / or double-symbol DMRS. NR networks may support a common DMRS structure for downlink and uplink (e.g., for cyclic prefix orthogonal frequency division multiplexing (CP-OFDM)), where the DMRS position, DMRS pattern, and / or scrambling sequence of the DMRS may be the same or different.

[0155] The PUSCH may include one or more layers, and the UE may transmit at least one symbol having a DMRS present on a layer in the one or more layers of the PUSCH. In an example, a higher layer may configure up to three DMRSs for the PUSCH.

[0156] Depending on the RRC configuration of the UE, the uplink PT-RS (which can be used by the base station for phase tracking and / or phase noise compensation) may or may not be present. The presence and / or type of the uplink PT-RS can be configured based on UE specificity through a combination of RRC signaling and / or one or more parameters indicated by the DCI for other purposes (e.g., modulation and coding scheme (MCS)). When configured, the dynamic presence of the uplink PT-RS can be associated with one or more DCI parameters including at least the MCS. The radio network can support multiple uplink PT-RS densities defined in the time / frequency domain. When present, the frequency domain density can be associated with at least one configuration of the scheduled bandwidth. The UE can use the same precoding for DMRS ports and PT-RS ports. The number of PT-RS ports can be less than the number of DMRS ports in the scheduled resources. For example, the uplink PT-RS can be restricted to the scheduled time / frequency duration of the UE.

[0157] The UE may transmit an SRS to the base station for channel state estimation to support uplink channel-dependent scheduling and / or link adaptation. The SRS transmitted by the UE may allow the base station to estimate the uplink channel state at one or more frequencies. The scheduler at the base station may use the estimated uplink channel state to assign one or more resource blocks for 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. The applicability of the SRS resource set may be configured by a higher layer (e.g., RRC) parameter. For example, when the higher layer parameter indicates beam management, the SRS resources in the one or more SRS resource sets (e.g., having the same / similar time domain behavior, periodic, aperiodic, etc.) may be transmitted at a certain time (e.g., at the same time). The UE may transmit one or more SRS resources in the SRS resource set. The NR network may support aperiodic, periodic, and / or semi-persistent SRS transmission. The UE may transmit SRS resources based on one or more trigger types, wherein the one or more trigger types may include higher layer signaling (e.g., RRC) and / or one or more DCI formats. In an example, at least one DCI format may be used for the UE to select at least one configured SRS resource set from one or more configured SRS resource sets. SRS trigger type 0 may refer to SRS triggered based on higher layer signaling. SRS trigger type 1 may refer to SRS triggered based on one or more DCI formats. In an example, when PUSCH and SRS are transmitted in the same time slot, the UE may be configured to transmit SRS after the transmission of PUSCH and the corresponding uplink DMRS.

[0158] The base station can semi-statically configure the UE using one or more SRS configuration parameters indicating at least one of the following: an SRS resource configuration identifier; the number of SRS ports; the time domain behavior of the SRS resource configuration (e.g., an indication of periodic, semi-persistent, or aperiodic SRS); time slot, mini-slot, and / or subframe level periodicity; time slot of periodic and / or aperiodic SRS resources; the number of OFDM symbols in the SRS resources; the starting OFDM symbol of the SRS resources; the SRS bandwidth; the frequency hopping bandwidth; the cyclic shift; and / or the SRS sequence ID.

[0159] Antenna ports are defined such that the channel over which a symbol on the antenna port is communicated can be inferred from the channel over which another symbol on the same antenna port is communicated. If a first symbol and a second symbol are transmitted on the same antenna port, the receiver can infer the channel (e.g., fading gain, multipath delay, etc.) used to communicate the second symbol on the antenna port from the channel used to communicate the first symbol on the antenna port. If one or more large-scale properties of the channel over which the first symbol on the first antenna port is communicated can be inferred from the channel over which the second symbol on the second antenna port is communicated, the first antenna port and the second antenna port can be referred to as quasi-co-located (QCLed). The one or more large-scale properties may include at least one of the following: delay spread; Doppler spread; Doppler shift; average gain; average delay; and / or spatial receive (Rx) parameters.

[0160] Channels using beamforming require beam management. Beam management can include beam measurement, beam selection, and beam indication. A beam can be associated with one or more reference signals. For example, a beam can be identified by one or more beamforming reference signals. The UE can perform downlink beam measurements based on downlink reference signals (e.g., channel state information reference signals (CSI-RS)) and generate beam measurement reports. After setting up an RRC connection with a base station, the UE can perform a downlink beam measurement procedure.

[0161] Figure 11B An example of a channel state information reference signal (CSI-RS) mapped in the time and frequency domain is shown. Figure 11BThe squares shown in the figure may represent resource blocks (RBs) within the bandwidth of the cell. The base station may transmit one or more RRC messages including CSI-RS resource configuration parameters indicating one or more CSI-RSs. One or more of the following parameters may be configured for the CSI-RS resource configuration via higher layer signaling (e.g., RRC and / or MAC signaling): CSI-RS resource configuration identity, number of CSI-RS ports, CSI-RS configuration (e.g., symbol and resource element (RE) positions in a subframe), CSI-RS subframe configuration (e.g., subframe position, offset, and periodicity in a radio frame), CSI-RS power parameters, CSI-RS sequence parameters, code division multiplexing (CDM) type parameters, frequency density, transmission comb, quasi co-location (QCL) parameters (e.g., QCL-scramblingidentity, crs-portscount, mbsfn-subframeconfiglist, csi-rs-configZPid, qcl-csi-rs-configNZPid), and / or other radio resource parameters.

[0162] Figure 11B The three beams shown may be configured for the UE in a UE-specific configuration. Figure 11B Three beams (beam #1, beam #2, and beam #3) are illustrated in FIG, and more or fewer beams may be configured. CSI-RS 1101 may be allocated to beam #1, which may be transmitted in one or more subcarriers in the RB of the first symbol. CSI-RS 1102 may be allocated to beam #2, which may be transmitted in one or more subcarriers in the RB of the second symbol. CSI-RS 1103 may be allocated to beam #3, which may be transmitted in one or more subcarriers in the RB of the third symbol. By using frequency division multiplexing (FDM), a base station may use other subcarriers in the same RB (e.g., those subcarriers not used to transmit CSI-RS 1101) to transmit another CSI-RS associated with a beam of another UE. By using time domain multiplexing (TDM), a beam for a UE may be configured such that the beam for the UE uses symbols from beams of other UEs.

[0163] CSI-RS, such as Figure 11BThose shown in (e.g., CSI-RS1101, 1102, 1103) can be transmitted by a base station and used by a UE for one or more measurement values. For example, the UE can measure the reference signal received power (RSRP) of the configured CSI-RS resource. The base station can configure the UE with a reporting configuration, and the UE can report the RSRP measurement value to the network (e.g., via one or more base stations) based on the reporting configuration. In the example, the base station can determine one or more transmission configuration indication (TCI) states including multiple reference signals based on the reported measurement results. In the example, the base station can indicate one or more TCI states to the UE (e.g., via RRC signaling, MAC CE and / or DCI). The UE can receive a downlink transmission with a receive (Rx) beam determined based on the one or more TCI states. In the example, the UE may or may not have beam correspondence capability. If the UE has beam correspondence capability, the UE can determine the spatial domain filter of the transmit (Tx) beam based on the spatial domain filter of the corresponding Rx beam. If the UE does not have beam-matching capability, the UE may perform an uplink beam selection process to determine the spatial domain filter for the Tx beam. The UE may perform an uplink beam selection process based on one or more sounding reference signal (SRS) resources configured for the UE by the base station. The base station may select and instruct the UE on an uplink beam based on measurements of one or more SRS resources transmitted by the UE.

[0164] During the beam management process, the UE may assess (e.g., measure) the channel quality of one or more beam pair links, including the beam pair links of the transmit beam transmitted by the base station and the receive 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, including, for example, one or more beam identifiers (e.g., beam index, reference signal index, etc.), RSRP, precoding matrix indicator (PMI), channel quality indicator (CQI), and / or rank indicator (RI).

[0165] Figure 12AExamples of three downlink beam management procedures are shown: P1, P2, and P3. Procedure P1 can enable UE measurements of the transmit (Tx) beams of a transmit reception point (TRP) (or multiple TRPs), for example to support selection of one or more base station Tx beams and / or UE Rx beams (shown as ovals in the top and bottom rows of P1, respectively). Beamforming at the TRP can include Tx beam sweeping for a set of beams (shown as ovals rotating in a counterclockwise direction indicated by dashed arrows in the top rows of P1 and P2). Beamforming at the UE can include Rx beam sweeping for a set of beams (shown as ovals rotating in a clockwise direction indicated by dashed arrows in the bottom rows of P1 and P3). Procedure P2 can be used to enable UE measurements of the Tx beams of the TRPs (shown as ovals rotating in a counterclockwise direction indicated by dashed arrows in the top row of P2). The UE and / or base station may perform process P2 using a smaller beam set than the beam set used in process P1, or using a narrower beam than the beam used in process P1. This may be referred to as beam refinement. The UE may perform process P3 for Rx beam determination by using the same Tx beam at the base station and sweeping the Rx beam at the UE.

[0166] Figure 12B Examples of three uplink beam management procedures are shown: U1, U2, and U3. Procedure U1 can be used to enable a base station to perform measurements on a UE's Tx beam, for example, to support selection of one or more UE Tx beams and / or base station Rx beams (shown as ovals in the top and bottom rows of U1, respectively). Beamforming at the UE can include, for example, Rx beam sweeping from a set of beams (shown as ovals rotating in a clockwise direction indicated by dashed arrows in the bottom rows of U1 and U3). Beamforming at the base station can include, for example, Rx beam sweeping from a set of beams (shown as ovals rotating in a counterclockwise direction indicated by dashed arrows in the top rows of U1 and U2). When the UE uses a fixed Tx beam, procedure U2 can be used to enable the base station to adjust its Rx beam. The UE and / or base station can perform procedure U2 using a smaller beam set than the beam set used in procedure P1, or using a narrower beam than the beam used in procedure P1. This may be referred to as beam refinement. The UE may perform procedure U3 to adjust its Tx beam when the base station uses a fixed Rx beam.

[0167] The UE may initiate a beam failure recovery (BFR) procedure based on detecting a beam failure. The UE may transmit a BFR request (e.g., preamble, UCI, SR, MAC CE, etc.) based on the initiation of the BFR procedure. The UE may detect a beam failure based on a determination that the quality of the beam-pair link of the associated control channel is unsatisfactory (e.g., having an error rate above an error rate threshold, a received signal power below a received signal power threshold, expiration of a timer, etc.).

[0168] The UE may measure the quality of a beam-pair link using one or more reference signals (RS), the one or more reference signals including one or more SS / PBCH blocks, one or more CSI-RS resources and / or one or more demodulation reference signals (DMRS). The quality of a beam-pair link may be based on one or more of the following: 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 an RS resource. The base station may indicate that the 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, etc.). When the channel characteristics (e.g., Doppler shift, Doppler spread, average delay, delay spread, spatial Rx parameters, fading, etc.) from the transmission to the UE via the RS resource are similar or identical to the channel characteristics from the transmission to the UE via the channel, the RS resource and the one or more DMRSs of the channel may be QCLed.

[0169] The network (e.g., gNB and / or ng-eNB of the network) and / or the UE may initiate a random access procedure. A UE in RRC_IDLE state and / or RRC_INACTIVE state may initiate a random access procedure to request connection setup to the network. The UE may initiate a random access procedure from the RRC_CONNECTED state. The UE may initiate a random access procedure to request uplink resources (e.g., uplink transmission for SR when there are no available PUCCH resources) and / or to acquire uplink timing (e.g., when the uplink synchronization state is not synchronized). The UE may initiate a random access procedure to request one or more system information blocks (SIBs) (e.g., other system information, such as SIB2, SIB3, etc.). The UE may initiate a random access procedure for a beam failure recovery request. The network may initiate a random access procedure for handover and / or for establishing time alignment for SCell addition.

[0170] Figure 13A A four-step contention-based random access procedure is shown. Before initiating the procedure, the base station may transmit a configuration message 1310 to the UE. Figure 13AThe process shown includes the transmission of four messages: Msg 1 1311, Msg 2 1312, Msg 3 1313, and Msg 4 1314. Msg 1 1311 may include and / or be referred to as a preamble (or random access preamble). Msg 2 1312 may include and / or be referred to as a random access response (RAR).

[0171] 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 include at least one of the 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 the UE in the RRC_CONNECTED state and / or the RRC_INACTIVE state). The UE may determine the time-frequency resources and / or uplink transmission power for transmitting Msg 1 1311 and / or Msg 3 1313 based on the one or more RACH parameters. Based on the one or more RACH parameters, the UE may determine the reception timing and downlink channel for receiving Msg 2 1312 and Msg 4 1314.

[0172] The one or more RACH parameters provided in the configuration message 1310 may indicate one or more physical RACH (PRACH) opportunities that may be used to transmit Msg 11311. The one or more PRACH opportunities may be predefined. The one or more RACH parameters may indicate one or more available sets of one or more PRACH opportunities (e.g., prach-ConfigIndex). The one or more RACH parameters may indicate an association between: (a) one or more PRACH opportunities, 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-RS. For example, the one or more RACH parameters may indicate the number of SS / PBCH blocks mapped to the PRACH opportunity and / or the number of preambles mapped to the SS / PBCH block.

[0173] The one or more RACH parameters provided in the configuration message 1310 may be used to determine the uplink transmission power of Msg 1 1311 and / or Msg 3 1313. For example, the one or more RACH parameters may indicate a reference power for preamble transmission (e.g., a received target power and / or an initial power for 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 ramp step size; a power offset between an SSB and a CSI-RS; a power offset between transmissions of Msg 1 1311 and Msg 3 1313; and / or a power offset value between preamble groups. The one or more RACH parameters may indicate one or more thresholds based on which the UE may determine at least one reference signal (e.g., an SSB and / or a CSI-RS) and / or an uplink carrier (e.g., a normal uplink (NUL) carrier and / or a supplementary uplink (SUL) carrier).

[0174] Msg 1 1311 may include one or more preamble transmissions (e.g., a preamble transmission and one or more preamble retransmissions). The RRC message may be used to configure one or more preamble groups (e.g., group A and / or group B). A preamble group may include one or more preambles. The UE may determine the preamble group based on the path loss measurement value and / or the size of Msg 3 1313. The UE may measure the RSRP of one or more reference signals (e.g., SSB and / or CSI-RS) and determine at least one reference signal having an RSRP greater than an RSRP threshold (e.g., rsrp-ThresholdSSB and / or rsrp-ThresholdCSI-RS). 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 select at least one preamble associated with the one or more reference signals and / or the selected preamble group.

[0175] 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 path loss measurement, an RSRP measurement, and / or the size of Msg 3 1313. As another example, the one or more RACH parameters may indicate: a preamble format; a maximum number of preamble transmissions; and / or one or more thresholds for determining one or more preamble groups (e.g., Group A and Group B). The base station may use the one or more RACH parameters to configure an association between one or more preambles and one or more reference signals (e.g., SSB and / or CSI-RS) for the UE. If the association is configured, the UE may determine the preamble included in Msg 1 1311 based on the association. Msg 1 1311 may be transmitted to the base station via one or more PRACH opportunities. The UE may use one or more reference signals (e.g., SSB and / or CSI-RS) to select a preamble and to determine a PRACH opportunity. One or more RACH parameters (eg, ra-ssb-OccasionMskIndex and / or ra-OccasionList) may indicate an association between a PRACH opportunity and the one or more reference signals.

[0176] If no response is received after the preamble transmission, the UE may perform a preamble retransmission. The UE may increase the uplink transmission power for the preamble retransmission. The UE may select the initial preamble transmission power based on the path loss measurement and / or the target received preamble power configured by the network. The UE may determine to retransmit the preamble and may ramp up the uplink transmission power. The UE may receive one or more RACH parameters (e.g., PREAMBLE_POWER_RAMPING_STEP) indicating the ramp-up step size for preamble retransmission. The ramp-up step size may be the amount of incremental increase in the uplink transmission power for retransmission. If the UE determines the same reference signal (e.g., SSB and / or CSI-RS) as the previous preamble transmission, the UE may ramp up the uplink transmission power. The UE may count the number of preamble transmissions and / or retransmissions (e.g., PREAMBLE_TRANSMISSION_COUNTER). For example, if the number of preamble transmissions exceeds a threshold (eg, preambleTransMax) configured by the one or more RACH parameters, the UE may determine that the random access procedure is not successfully completed.

[0177] Msg 2 1312 received by the UE may include a RAR. In some scenarios, Msg 2 1312 may include multiple RARs corresponding to multiple UEs. Msg 2 1312 may be received after or in response to the transmission of Msg 1 1311. Msg 2 1312 may be scheduled on the DL-SCH and indicated on the PDCCH using a random access RNTI (RA-RNTI). Msg 2 1312 may indicate that Msg 1 1311 was received by the base station. Msg 2 1312 may include a time alignment command that the UE may use to adjust the UE's transmission timing, a scheduling grant for transmitting Msg 3 1313, and / or a temporary cell RNTI (TC-RNTI). After transmitting the preamble, the UE may initiate a time window (e.g., a RA-ResponseWindow) to monitor the PDCCH for Msg 2 1312. The UE may determine when to start the time window based on the PRACH opportunity that the UE uses to transmit the preamble. For example, the UE may start a time window of one or more symbols after the last symbol of the preamble (e.g., at the first PDCCH opportunity starting from the end of the preamble transmission). The one or more symbols may be determined based on a parameter set. The PDCCH may be in a common search space (e.g., Type1-PDCCH common search space) configured by an RRC message. The UE may identify the RAR based on a radio network temporary identifier (RNTI). The RNTI may be used depending on one or more events that initiate a random access procedure. The UE may use a random access RNTI (RA-RNTI). The RA-RNTI may be associated with the PRACH opportunity in which the UE transmits the preamble. For example, the UE may determine the RA-RNTI based on: an OFDM symbol index; a time slot index; a frequency domain index; and / or a UL carrier indicator of a PRACH opportunity. Examples of RA-RNTI may be as follows:

[0178] RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id

[0179] Where s_id may be the index of the first OFDM symbol of the PRACH opportunity (e.g., 0≤s_id<14), t_id may be the index of the first time slot of the PRACH opportunity in the system frame (e.g., 0≤t_id<80), f_id may be the index of the PRACH opportunity in the frequency domain (e.g., 0≤f_id<8), and ul_carrier_id may be the UL carrier used for preamble transmission (e.g., 0 for NUL carrier and 1 for SUL carrier).

[0180] The UE may transmit Msg3 1313 in response to successfully receiving Msg 2 1312 (e.g., using the resources identified in Msg 2 1312). Msg 3 1313 may be used, for example, Figure 13A 1314 ). Contention resolution in a contention-based random access procedure as shown in . In some scenarios, multiple UEs may transmit the same preamble to a base station, and the base station may provide RARs corresponding to the UEs. If the multiple UEs interpret the RARs as corresponding to themselves, a collision may occur. Contention resolution (e.g., using Msg 3 1313 and Msg 4 1314) may be used to increase the likelihood that a UE does not mistakenly use the identity of another UE. To perform contention resolution, the UE may include a device identifier in Msg 3 1313 (e.g., if a C-RNTI is assigned, the TC-RNTI included in Msg 2 1312 and / or any other suitable identifier).

[0181] Msg 4 1314 may be received after or in response to the transmission of Msg 3 1313. If a C-RNTI is included in Msg 3 1313, the base station will use the C-RNTI to address the UE on the PDCCH. If the UE's unique C-RNTI is detected on the PDCCH, the random access procedure is determined to have been successfully completed. If a TC-RNTI is included in Msg 3 1313 (e.g., if the UE is in the RRC_IDLE state or is not otherwise connected to the base station), Msg 4 1314 will be received using the DL-SCH associated with the TC-RNTI. If the MAC PDU is successfully decoded and the MAC PDU includes a UE contention resolution identity MAC CE that matches or otherwise corresponds to the CCCH SDU sent (e.g., transmitted) in Msg 3 1313, the UE may determine that contention resolution was successful and / or the UE may determine that the random access procedure was successfully completed.

[0182] The UE may be configured with a supplementary uplink (SUL) carrier and a normal uplink (NUL) carrier. Initial access (e.g., a random access procedure) may be supported in an uplink carrier. For example, a base station may configure two separate RACH configurations for a UE: one for the SUL carrier and another for the NUL carrier. For random access in a cell configured with a SUL carrier, the network may indicate which carrier (NUL or SUL) to use. For example, if the measured quality of one or more reference signals is below a broadcast threshold, the UE may determine the SUL carrier. The uplink transmissions (e.g., Msg 1 1311 and / or Msg 3 1313) of the random access procedure may remain on the selected carrier. In one or more cases, the UE may switch uplink carriers during the random access procedure (e.g., between Msg 1 1311 and Msg 3 1313). For example, the UE may determine and / or switch an uplink carrier for Msg 1 1311 and / or Msg 3 1313 based on channel clarity assessment (eg, listen before talk).

[0183] Figure 13B The two-step contention-free random access process is shown. Figure 13A Similar to the four-step contention-based random access procedure shown, the base station may transmit a configuration message 1320 to the UE before the procedure is initiated. The configuration message 1320 may be similar to the configuration message 1310 in some aspects. Figure 13B The process shown includes the transmission of two messages: Msg 1 1321 and Msg 2 1322. Msg 1 1321 and Msg 2 1322 may be similar in some respects to Figure 13A As shown in Msg 1 1311 and Msg 2 1312. Figure 13A and Figure 13B It will be appreciated that the contention-free random access procedure may not include messages similar to Msg 3 1313 and / or Msg 4 1314 .

[0184] Can be initiated for beam failure recovery, other SI requests, SCell addition and / or handover Figure 13B For example, the base station may indicate or assign a preamble to be used for Msg 1 1321 to the UE. The UE may receive an indication of the preamble (eg, ra-PreambleIndex) from the base station via PDCCH and / or RRC.

[0185] After transmitting the preamble, the UE may start a time window (e.g., ra-ResponseWindow) to monitor the PDCCH for the RAR. In the case of a beam failure recovery request, the base station may configure the UE with a separate time window and / or a separate PDCCH in the search space indicated by the RRC message (e.g., recoverySearchSpaceId). The UE may monitor PDCCH transmissions addressed to the Cell RNTI (C-RNTI) on the search space. Figure 13B In the illustrated contention-free random access procedure, the UE may determine that the random access procedure has been successfully completed after or in response to the transmission of Msg 1 1321 and the reception of the corresponding Msg 2 1322. For example, if the PDCCH transmission is addressed to the C-RNTI, the UE may determine that the random access procedure has been successfully completed. For example, if the UE receives a RAR including a preamble identifier corresponding to the preamble transmitted by the UE and / or the RAR includes a MAC sub-PDU with the preamble identifier, the UE may determine that the random access procedure has been successfully completed. The UE may determine that the response is an indication of confirmation of the SI request.

[0186] Figure 13C Another two-step random access process is shown. Figure 13A and Figure 13B Similar to the random access procedure shown, the base station may transmit a configuration message 1330 to the UE before the procedure is initiated. Configuration message 1330 may be similar to configuration message 1310 and / or configuration message 1320 in some aspects. Figure 13C The process shown includes the transmission of two messages: Msg A 1331 and Msg B 1332.

[0187] Msg A 1331 may be transmitted by the UE in an uplink transmission. Msg A 1331 may include one or more transmissions of a preamble 1341 and / or one or more transmissions of a transport block 1342. Transport block 1342 may include Figure 13A The transmission block 1342 may include UCI (e.g., SR, HARQ ACK / NACK, etc.). The UE may receive Msg B 1332 after or in response to the transmission of Msg A 1331. Msg B 1332 may include the same content as the content of Msg 3 1313 shown in FIG. Figure 13A and Figure 13B Msg 2 1312 (eg, RAR) and / or Figure 13A The content of Msg 4 1314 is similar and / or identical to that of Msg 4 1314 shown.

[0188] The UE can initiate a call for licensed spectrum and / or unlicensed spectrum. Figure 13C The UE may determine whether to initiate a two-step random access procedure based on one or more factors. The one or more factors may include: the radio access technology being used (e.g., LTE, NR, etc.); whether the UE has a valid TA; the cell size; the RRC state of the UE; the type of spectrum (e.g., licensed vs. unlicensed); and / or any other suitable factors.

[0189] The UE may determine the radio resources and / or uplink transmission power of the preamble 1341 and / or transport block 1342 included in Msg A 1331 based on the two-step RACH parameters included in the configuration message 1330. The RACH parameters may indicate the modulation and coding scheme (MCS), time-frequency resources, and / or power control of the preamble 1341 and / or transport block 1342. The time-frequency resources (e.g., PRACH) used for transmission of the preamble 1341 and the time-frequency resources (e.g., PUSCH) used for transmission of the transport block 1342 may be multiplexed using FDM, TDM, and / or CDM. The RACH parameters may enable the UE to determine the reception timing and downlink channel used for monitoring and / or receiving Msg B 1332.

[0190] Transport block 1342 may include 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 Msg B 1332 in response to Msg A 1331. Msg B 1332 may include at least one of the following: a preamble identifier; a timing high-level command; a power control command; an uplink grant (e.g., a radio resource assignment and / or MCS); a UE identifier for contention resolution; and / or an RNTI (e.g., a C-RNTI or TC-RNTI). The UE may determine that the two-step random access procedure is successfully completed if: the preamble identifier in Msg B 1332 matches the preamble transmitted by the UE; and / or the UE identifier in Msg B 1332 matches the UE identifier in Msg A 1331 (e.g., transport block 1342).

[0191] The UE and the 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 include downlink control signaling transmitted from the base station to the UE and / or uplink control signaling transmitted from the UE to the base station.

[0192] Downlink control signaling may include: downlink scheduling assignments; uplink scheduling grants indicating uplink radio resources and / or transport formats; time slot format information; preemption indications; power control commands; and / or any other suitable signaling. The UE may receive 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) common to a group of UEs.

[0193] The base station may attach one or more cyclic redundancy check (CRC) parity bits to the DCI to facilitate detection of transmission errors. When the DCI is intended for a UE (or a group of UEs), the base station may scramble the CRC parity bits with an identifier for the UE (or an identifier for the group of UEs). Scrambling the CRC parity bits with the identifier may include a Modulo-2 addition (or an exclusive OR operation) of the identifier value and the CRC parity bits. The identifier may include a 16-bit value of a Radio Network Temporary Identifier (RNTI).

[0194] DCI can be used for different purposes. The purpose can be indicated by the type of RNTI used to scramble the CRC parity bits. For example, a DCI with CRC parity bits scrambled with a paging RNTI (P-RNTI) can indicate paging information and / or system information change notification. The P-RNTI can be predefined as "FFFE" in hexadecimal. A DCI with CRC parity bits scrambled with a system information RNTI (SI-RNTI) can indicate a broadcast transmission of system information. The SI-RNTI can be predefined as "FFFF" in hexadecimal. A DCI with CRC parity bits scrambled with a random access RNTI (RA-RNTI) can indicate a random access response (RAR). A DCI with CRC parity bits scrambled with a cell RNTI (C-RNTI) can indicate a dynamically scheduled unicast transmission and / or the triggering of a PDCCH ordered random access. A DCI with CRC parity bits scrambled with a temporary cell RNTI (TC-RNTI) can indicate contention resolution (e.g., similar to Figure 13AThe other RNTIs configured by the base station to the UE may include: the configured scheduling RNTI (CS-RNTI), transmit power control PUCCH RNTI (TPC-PUCCH-RNTI), transmit power control PUSCH RNTI (TPC-PUSCH-RNTI), transmit power control SRS RNTI (TPC-SRS-RNTI), interruption RNTI (INT-RNTI), slot format indication RNTI (SFI-RNTI), semi-persistent CSI RNTI (SP-CSI-RNTI), modulation and coding scheme cell RNTI (MCS-C-RNTI), etc.

[0195] Depending on the purpose and / or content of the DCI, the base station may transmit DCI with one or more DCI formats. For example, DCI format 0_0 may be used for scheduling PUSCH in a cell. DCI format 0_0 may be a fallback DCI format (e.g., with a compact DCI payload). DCI format 0_1 ​​may be used for scheduling PUSCH in a cell (e.g., with a larger DCI payload than DCI format 0_0). DCI format 1_0 may be used for scheduling PDSCH in a cell. DCI format 1_0 may be a fallback DCI format (e.g., with a compact DCI payload). DCI format 1_1 may be used for scheduling PDSCH in a cell (e.g., with a larger DCI payload than DCI format 1_0). DCI format 2_0 may be used to provide a slot format indication to a UE group. DCI format 2_1 may be used to notify a UE group of physical resource blocks and / or OFDM symbols, where the UE may assume that no transmission to the UE is expected. DCI format 2_2 may be used to transmit a transmit power control (TPC) command for PUCCH or PUSCH. DCI formats 2_3 can be used to transmit a set of TPC commands for SRS transmission by one or more UEs. DCI formats for new functions may be defined in future releases. DCI formats can have different DCI sizes or can share the same DCI size.

[0196] After scrambling the DCI with the RNTI, the base station can process the DCI with channel coding (e.g., polarity coding), rate matching, scrambling and / or QPSK modulation. The base station can map the coded and modulated DCI on resource elements used for and / or configured for PDCCH. Based on the payload size of the DCI and / or the coverage of the base station, the base station can transmit the DCI via a PDCCH occupying multiple consecutive control channel elements (CCEs). The number of consecutive CCEs (referred to as the aggregation level) can be 1, 2, 4, 8, 16 and / or any other suitable number. CCE may include the number of resource element groups (REGs) (e.g., 6). REG may include a resource block in an OFDM symbol. The mapping of the coded and modulated DCI on the resource elements can be based on the mapping of CCEs and REGs (e.g., CCE to REG mapping).

[0197] Figure 14A An example of a CORESET configuration for a bandwidth portion is shown. The base station may transmit DCI via PDCCH on one or more control resource sets (CORESETs). A CORESET may include time-frequency resources in which the UE attempts to decode the DCI using one or more search spaces. The base station may configure the CORESET in the time-frequency domain. Figure 14A In the example shown in FIG1 , first CORESET 1401 and second CORESET 1402 appear at the first symbol in a time slot. First CORESET 1401 overlaps with second CORESET 1402 in the frequency domain. Third CORESET 1403 appears at the third symbol in a time slot. Fourth CORESET 1404 appears at the seventh symbol in a time slot. CORESETs can have different numbers of resource blocks in the frequency domain.

[0198] Figure 14B An example of CCE to REG mapping for DCI transmission on a CORESET and PDCCH processing is shown. The CCE to REG mapping can be an interleaved mapping (e.g., for the purpose of providing frequency diversity) or a non-interleaved mapping (e.g., for the purpose of facilitating interference coordination and / or frequency selective transmission of control channels). The base station can perform different or the same CCE to REG mapping for different CORESETs. A CORESET can be associated with the CCE to REG mapping through RRC configuration. A CORESET can be configured with an antenna port quasi-co-location (QCL) parameter. The antenna port QCL parameter can indicate the QCL information of the demodulation reference signal (DMRS) for PDCCH reception in the CORESET.

[0199] The base station may transmit an RRC message including configuration parameters of one or more CORESETs and one or more search space sets to the UE. The configuration parameters may indicate the association between the search space set and the CORESET. The search space set may include a set of PDCCH candidates formed by CCEs at a given aggregation level. The configuration parameters may indicate: the number of PDCCH candidates to be monitored per aggregation level; the PDCCH monitoring period and the PDCCH monitoring pattern; one or more DCI formats to be monitored by the UE; and / or whether the search space set is a common search space set or a UE-specific search space set. The set of CCEs in the common search space set may be predefined and known to the UE. The set of CCEs in the UE-specific search space set may be configured based on the identity of the UE (e.g., C-RNTI).

[0200] like Figure 14B As shown, the UE may determine the time-frequency resources of the CORESET based on the RRC message. The UE may determine the CCE to REG mapping of the CORESET based on the configuration parameters of the CORESET (e.g., interleaving or non-interleaving and / or mapping parameters). The UE may determine the number of search space sets configured on the CORESET based on the RRC message (e.g., up to 10). The UE may monitor a set of PDCCH candidates based on the configuration parameters of the search space set. The UE may monitor a set of PDCCH candidates in one or more CORESETs for detecting one or more DCIs. Monitoring may include decoding one or more PDCCH candidates in the set of PDCCH candidates based on the monitored DCI format. Monitoring may include decoding DCI content of one or more PDCCH candidates, which have possible (or configured) PDCCH positions, possible (or configured) PDCCH formats (e.g., the number of CCEs, the number of PDCCH candidates in the common search space, and / or the number of PDCCH candidates in the UE-specific search space), and possible (or configured) DCI formats. Decoding may be referred to as blind decoding. The UE may determine that the DCI is valid for the UE in response to a CRC check (e.g., scrambled bits of the CRC parity bits of the DCI matching the RNTI value). The UE may process the information contained in the DCI (e.g., scheduling assignments, uplink grants, power control, slot format indications, downlink preemption, etc.).

[0201] The UE may transmit uplink control signaling (e.g., uplink control information (UCI)) to the base station. The uplink control signaling transmission may include a hybrid automatic repeat request (HARQ) acknowledgment for the received DL-SCH transport block. The UE may transmit the HARQ acknowledgment after receiving the DL-SCH transport block. The uplink control signaling may include channel state information (CSI) indicating the channel quality of the physical downlink channel. The UE may transmit the CSI to the base station. Based on the received CSI, the base station may determine the transport format parameters for downlink transmission (e.g., including multiple antennas and beamforming schemes). The uplink control signaling may include a scheduling request (SR). The UE may transmit the SR indicating that uplink data is available for transmission to the base station. The UE may transmit UCI (e.g., HARQ acknowledgment (HARQ-ACK), CSI report, SR, etc.) via a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH). The UE may transmit uplink control signaling via the PUCCH using one of several PUCCH formats.

[0202] There may be five PUCCH formats, and the UE may determine the PUCCH format based on the size of the UCI (e.g., the number of uplink symbols for UCI transmission and the number of UCI bits). PUCCH format 0 may have a length of one or two OFDM symbols and may include two or fewer bits. If the transmission exceeds one or two symbols and the number of HARQ-ACK information bits (HARQ-ACK / SR bits) with positive or negative SR is one or two, the UE may use PUCCH format 0 to transmit UCI in the PUCCH resource. PUCCH format 1 may occupy between four and fourteen OFDM symbols and may include two or fewer bits. If four or more symbols are transmitted and the number of HARQ-ACK / SR bits is one or two, the UE may use PUCCH format 1. PUCCH format 2 may occupy one or two OFDM symbols and may include more than two bits. If the transmission exceeds one or two symbols and the number of UCI bits is two or more, the UE may use PUCCH format 2. PUCCH format 3 may occupy between four and fourteen OFDM symbols and may include more than two bits. If four or more symbols are transmitted, the number of UCI bits is two or more, and the PUCCH resources do not include orthogonal cover codes, the UE may use PUCCH format 3. PUCCH format 4 may occupy between four and fourteen OFDM symbols and may include more than two bits. If four or more symbols are transmitted, the number of UCI bits is two or more, and the PUCCH resources include orthogonal cover codes, the UE may use PUCCH format 4.

[0203] The base station may transmit configuration parameters of multiple PUCCH resource sets to the UE using, for example, an RRC message. The multiple PUCCH resource sets (e.g., up to four sets) may be configured on the uplink BWP of the cell. The PUCCH resource set may be configured with: a PUCCH resource set index; multiple PUCCH resources having PUCCH resources identified by a PUCCH resource identifier (e.g., pucch-Resourceid); and / or multiple (e.g., maximum number) UCI ​​information bits that the UE may transmit using one of the multiple PUCCH resources in the PUCCH resource set. When multiple PUCCH resource sets are configured, the UE may select one PUCCH resource set (e.g., HARQ-ACK, SR, and / or CSI) from the multiple PUCCH resource sets based on the total bit length of the UCI information bits. If the total bit length of the UCI information bits is two or less, the UE may select the first PUCCH resource set with a PUCCH resource set index equal to "0". If the total bit length of the UCI information bits is greater than two and less than or equal to the 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 the UCI information bits is greater than the first configured value and less than or equal to the 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 the 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".

[0204] After determining a PUCCH resource set from a plurality of PUCCH resource sets, the UE may determine the PUCCH resources for UCI (HARQ-ACK, CSI, and / or SR) transmission from the PUCCH resource set. The UE may determine the PUCCH resources based on a PUCCH resource indicator in a DCI received on a PDCCH (e.g., a DCI format 1_0 or a DCI for 1_1). The 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 use the PUCCH resource indicated by the PUCCH resource indicator in the DCI to transmit UCI (HARQ-ACK, CSI, and / or SR).

[0205] Figure 15 An example of a wireless device 1502 in communication with a base station 1504 is shown according to an embodiment of the present disclosure. The wireless device 1502 and the base station 1504 may be part of a mobile communication network, such as Figure 1A The mobile communication network 100 shown, Figure 1B The mobile communication network 150 shown or any other communication network. Figure 15 Only one wireless device 1502 and one base station 1504 are shown in FIG. 1 , but it should be understood that a mobile communication network may include more than one UE and / or more than one base station with the same Figure 15 The same or similar configurations as those shown.

[0206] The base station 1504 can connect the wireless device 1502 to a core network (not shown) via radio communication over an air interface (or radio interface) 1506. The direction of communication from the base station 1504 to the wireless device 1502 over the air interface 1506 is referred to as downlink, while the direction of communication from the wireless device 1502 to the base station 1504 over the air interface is referred to as uplink. Downlink transmissions can be separated from uplink transmissions using FDD, TDD, and / or some combination of the two duplexing techniques.

[0207] In the downlink, data to be transmitted from the base station 1504 to the wireless device 1502 may be provided to the processing system 1508 of the base station 1504. The data may be provided to the processing system 1508 via, for example, the core network. In the uplink, data to be transmitted from the wireless device 1502 to the base station 1504 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 functions to process the data for transmission. Layer 2 may include, for example, information about Figure 2A 、 Figure 2B 、 Figure 3 and Figure 4A Layer 3 may include the SDAP layer, PDCP layer, RLC layer and MAC layer. Figure 2B RRC layer.

[0208] After processing by processing system 1508, data to be transmitted to wireless device 1502 may be provided to transmission processing system 1510 of base station 1504. Similarly, after processing by processing system 1518, data to be transmitted to base station 1504 may be provided to transmission processing system 1520 of wireless device 1502. Transmission processing system 1510 and transmission processing system 1520 may implement layer 1 OSI functions. Layer 1 may include information about Figure 2A 、 Figure 2B 、 Figure 3 and Figure 4A For transmission processing, the PHY layer may perform, for example, forward error correction coding of transport channels, interleaving, rate matching, mapping of transport channels to physical channels, modulation of physical channels, multiple-input multiple-output (MIMO) or multi-antenna processing, and the like.

[0209] At base station 1504, receive processing system 1512 may receive uplink transmissions from wireless device 1502. At wireless device 1502, receive processing system 1522 may receive downlink transmissions from base station 1504. Receive processing system 1512 and receive processing system 1522 may implement layer 1 OSI functionality. Layer 1 may include information about Figure 2A 、 Figure 2B 、 Figure 3 and Figure 4A For receive processing, the PHY layer may perform, for example, error detection, forward error correction decoding, deinterleaving, demapping of transport channels to physical channels, demodulation of physical channels, MIMO or multi-antenna processing, and the like.

[0210] like Figure 15 As shown, wireless device 1502 and base station 1504 may include multiple antennas. The multiple antennas may be used to implement one or more MIMO or multi-antenna techniques, such as spatial multiplexing (e.g., single-user MIMO or multi-user MIMO), transmit / receive diversity, and / or beamforming. In other examples, wireless device 1502 and / or base station 1504 may have a single antenna.

[0211] Processing system 1508 and processing system 1518 may be associated with memory 1514 and memory 1524, respectively. Memory 1514 and memory 1524 (e.g., one or more non-transitory computer-readable media) may store computer program instructions or code that may be executed by processing system 1508 and / or processing system 1518 to perform one or more of the functions discussed herein. Figure 15 Not shown, transmit processing system 1510, transmit processing system 1520, receive processing system 1512, and / or receive processing system 1522 may be coupled to a memory (e.g., one or more non-transitory computer-readable media) storing computer program instructions or code that may be executed to perform one or more of their respective functions.

[0212] The processing system 1508 and / or the processing system 1518 may include one or more controllers and / or one or more processors. The one or more controllers and / or one or more processors may include, 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, onboard units, or any combination thereof. The processing system 1508 and / or the processing system 1518 may perform at least one of the following: signal encoding / 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.

[0213] The processing system 1508 and / or the processing system 1518 can be connected to one or more peripheral devices 1516 and one or more peripheral devices 1526, respectively. The one or more peripheral devices 1516 and the one or more peripheral devices 1526 can include software and / or hardware that provides features and / or functionality, such as a speaker, a microphone, a keyboard, a display, a touchpad, a power supply, a satellite transceiver, a universal serial bus (USB) port, a hands-free headset, a frequency modulation (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, etc.). The processing system 1508 and / or the processing system 1518 can receive user input data from the one or more peripheral devices 1516 and / or the one or more peripheral devices 1526 and / or provide user output data to the one or more peripheral devices. The processing system 1518 in the wireless device 1502 can receive power from a power source and / or can be configured to distribute power to other components in the wireless device 1502. The power source can include one or more power sources, such as batteries, solar cells, fuel cells, or any combination thereof. The processing system 1508 and / or the processing system 1518 can be connected to a GPS chipset 1517 and a GPS chipset 1527, respectively. The GPS chipset 1517 and the GPS chipset 1527 can be configured to provide geographic location information of the wireless device 1502 and the base station 1504, respectively.

[0214] Figure 16AAn exemplary structure for uplink transmission is shown. The baseband signal representing the physical uplink shared channel can perform one or more functions. The one or more functions may include at least one of the following: scrambling; modulating scrambled bits to generate complex-valued symbols; mapping complex-valued modulated symbols to one or several transmission layers; transform precoding to generate complex-valued symbols; precoding of complex-valued symbols; mapping of precoded complex-valued symbols to resource elements; generating complex-valued time-domain single-carrier frequency division multiple access (SC-FDMA) or CP-OFDM signals for antenna ports; and the like. In the example, when transform precoding is enabled, an SC-FDMA signal for uplink transmission can be generated. In the example, when transform precoding is not enabled, the uplink transmission can be performed by Figure 16A Generates a CP-OFDM signal for uplink transmission. These functions are shown as examples, and it is contemplated that other mechanisms may be implemented in various embodiments.

[0215] Figure 16B An exemplary structure for modulation and up-conversion of a baseband signal to a carrier frequency is shown. The baseband signal can be a complex-valued SC-FDMA or CP-OFDM baseband signal for an antenna port and / or a complex-valued physical random access channel (PRACH) baseband signal. Filtering can be employed prior to transmission.

[0216] Figure 16C An exemplary structure for downlink transmission is shown. The baseband signal representing the physical downlink channel can perform one or more functions. These one or more functions may include: scrambling coded bits in a codeword to be transmitted on the physical channel; modulating the scrambled bits to generate complex-valued modulation symbols; mapping the complex-valued modulation symbols onto one or more transmission layers; precoding the complex-valued modulation symbols on the layers for transmission on the antenna ports; mapping the complex-valued modulation symbols for the antenna ports to resource elements; generating a complex-valued time-domain OFDM signal for the antenna ports; and so on. These functions are shown as examples, and it is contemplated that other mechanisms may be implemented in various embodiments.

[0217] Figure 16D Another exemplary structure for modulation and up-conversion of a baseband signal to a carrier frequency is shown. The baseband signal can be a complex-valued OFDM baseband signal at the antenna port. Filtering can be applied before transmission.

[0218] A wireless device may receive one or more messages (e.g., RRC messages) from a base station including configuration parameters for multiple cells (e.g., a primary cell, a secondary cell). The wireless device may communicate with at least one base station (e.g., two or more base stations in dual connectivity) via multiple cells. The one or more messages (e.g., as part of the configuration parameters) may include parameters for configuring the wireless device at the physical layer, MAC layer, RLC layer, PCDP layer, SDAP layer, or RRC layer. For example, the configuration parameters may include parameters for configuring physical layer and MAC layer channels, bearers, etc. For example, the configuration parameters may include parameters indicating values ​​of timers for the physical layer, MAC layer, RLC layer, PCDP layer, SDAP layer, RRC layer, and / or communication channels.

[0219] Once started, a timer can begin running and continue running until it is stopped or expires. If a timer is not running, it can be started, or if it is running, it can be restarted. A timer can be associated with a value (e.g., a timer can start or restart at a certain value, or can start at 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 a BWP switch). A timer can be used to measure a time period / window in a measurement process. When the description refers to implementations and processes related to one or more timers, it should be understood that there are various ways to implement the one or more timers. For example, it should be understood that one or more of these various ways of implementing a timer can be used to measure a time period / window in a measurement process. For example, a random access response window timer can be used to measure the time window for receiving a random access response. In an example, instead of the start and expiration of the random access response window timer, the time difference between two timestamps can be used. When the timer is restarted, the measurement process for the time window can be restarted. Other exemplary implementations can be provided to restart the measurement of the time window.

[0220] When an RRC connection is established, the UE may be in an RRC connected state or an RRC inactive state. When no RRC connection is established, the UE is in an RRC idle state.

[0221] When the UE is in the RRC idle state, the UE (its RRC layer) or the base station may support PLMN selection; broadcast of system information; cell reselection mobility; paging for mobile terminated data initiated by 5GC; and DRX for core network (CN) paging configured by the non-access stratum (NAS). When the UE is in the RRC idle state, UE-specific DRX may be configured by upper layers; and / or the UE controls mobility based on network configuration. When the UE is in the RRC idle state, the UE (its RRC layer) may: monitor short messages transmitted via DCI with P-RNTI; monitor the paging channel for core network (CN) paging using a service temporary mobile subscriber identity (S-TMSI) (e.g., 5G-S-TMSI); perform neighboring cell measurements and cell (re)selection; obtain system information; send SI requests; perform logging of available measurements and configure logging of the UE's location and time for the logged measurements.

[0222] When a UE is in an RRC Inactive state, the UE (its RRC layer) or base station may support PLMN selection; broadcast of system information; cell reselection mobility; paging initiated by the NG-RAN (RAN paging); management of the RAN-based Notification Area (RNA) by the NG-RAN; DRX for RAN paging configured by the NG-RAN; the core network (e.g., 5G Core, 5GC) - establishing a RAN (e.g., base station) connection (control plane and / or user plane) for the UE; storing the UE AS context in the RAN and the UE; and the RAN being aware of the RNA to which the UE belongs. For example, when the UE (its RRC layer) is in an RRC Inactive state, UE-specific DRX may be configured by upper layers or the RRC layer; the UE may perform / support UE-controlled mobility based on network configuration; the UE may store the UE inactive AS context; and the RAN-based Notification Area (RNA) may be configured by the RRC layer. When the UE is in the RRC inactive state, the UE (its RRC layer) may: monitor short messages transmitted via DCI with a P-RNTI; monitor the paging channel for CN paging using an S-TMSI and monitor the paging channel for RAN paging using a completely inactive RNTI (I-RNTI) (or a complete recovery identity); perform neighbor cell measurements and cell (re)selection; perform RAN-based notification area (RNA) updates periodically and when moving out of the configured RAN-based notification area; obtain system information; send an SI request; perform logging of available measurements and configure logging of the UE's location and time for the logged measurements.

[0223] When the UE is in the RRC connected state, the UE (RRC layer) or the base station can support: 5GC-establishment of NG-RAN connection for the UE (both C-plane / U-plane); storage of UE AS context in the RAN (e.g. base station) and the UE; RAN awareness of the cell to which the UE belongs; delivery of unicast data to / from the UE; network-controlled mobility, including measurements. For example, when the UE is in the RRC connected state, the UE (its RRC layer) can: store AS context; deliver / receive unicast data; be configured with UE-specific DRX at the lower layer; for UEs supporting CA, use one or more SCells aggregated with SpCell to increase bandwidth; for UEs supporting DC, use one SCG aggregated with MCG to increase bandwidth; perform / support network controlled mobility within NR and to / from E-UTRA; when the UE is in the RRC connected state, the UE can: monitor short messages transmitted with P-RNTI via DCI; monitor the control channel associated with the shared data channel to determine whether data is scheduled for the control channel; provide channel quality and feedback information; perform neighbor cell measurements and measurement reports; obtain system information; perform immediate minimization of drive test (MDT) measurements and available location reports.

[0224] Radio bearers can be divided into two groups: Data Radio Bearers (DRBs) for user plane data and Signalling Radio Bearers (SRBs) for control plane data.

[0225] A Signaling Radio Bearer (SRB) may be defined as a radio bearer (RB) used only for transporting RRC and NAS messages. The following SRBs may be defined: SRB0 may be used for RRC messages using the Common Control Channel (CCCH) logical channel; SRB1 may be used for RRC messages (which may include piggybacked NAS messages) and for NAS messages before SRB2 is established, all of which use the Dedicated Control Channel (DCCH) logical channel; SRB2 may be used for NAS messages and RRC messages, which may include logged measurement information, all of which use the DCCH logical channel. SRB2 may have a lower priority than SRB1 and may be configured by the network after access stratum (AS) security is activated; SRB3 may be used for specific RRC messages when the UE is in dual connectivity (e.g., (NG)EN-DC or NR-DC), all of which use the DCCH logical channel. In the downlink, piggybacking of NAS messages may be used for a related (e.g., with joint success / failure) Procedure: Bearer establishment / modification / release. In the uplink, piggybacking of NAS messages can be used to deliver initial NAS messages during (RRC) connection setup and (RRC) connection recovery. NAS messages delivered via SRB2 can be contained in RRC messages, which may not include any RRC protocol control information. Once AS security is activated, all RRC messages on SRB1, SRB2, and SRB3 (including those containing NAS messages) can be integrity protected and encrypted by PDCP. NAS can apply integrity protection and encryption to NAS messages independently. Split SRBs can be supported in both SRB1 and SRB2 to achieve dual connectivity (e.g., multi-radio (MR)-DC option). SRB0 and SRB3 may not support split SRBs. For operations with shared spectrum channel access, SRB0, SRB1, and SRB3 can be assigned the highest priority channel access priority category (CAPC) (e.g., CAPC=1), while the CAPC for SRB2 is configurable.

[0226] The MAC layer of a UE or base station can provide different types of data transfer services. Each logical channel type can be defined by the type of information it transfers. Logical channels can be divided into two groups: control channels and traffic channels. Control channels can be used to transfer control plane information: the Broadcast Control Channel (BCCH), which is a downlink channel used to broadcast system control information; the Paging Control Channel (PCCH), which is a downlink channel that carries paging messages; the Common Control Channel (CCCH), which is a channel used to transmit control information between the UE and the network. This channel is used for UEs that do not have an RRC connection with the network; and the Dedicated Control Channel (DCCH), which is a point-to-point bidirectional channel that transmits dedicated control information between the UE and the network. It is used by UEs with an RRC connection. Traffic channels can be used to transfer user plane information: the Dedicated Traffic Channel (DTCH), which is a point-to-point channel dedicated to one UE and used to transfer user information. The DTCH can exist in both the uplink and downlink.

[0227] When establishing or resuming an RRC connection, the UE may transition to the RRC Connected state. When the RRC connection is released or suspended, the UE may transition to the RRC Idle state. When the RRC connection is suspended, the UE may transition to the RRC Inactive state. When the UE is in the RRC Idle state, the UE may have a suspended RRC connection. Based on the RRC connection suspended in the RRC Idle state, the UE is in the RRC Idle state with a suspended RRC connection.

[0228] The RRC connection establishment may include the establishment of SRB1. The base station may complete the RRC connection establishment before completing the connection establishment with the core network (e.g., N2 / N3 connection) (e.g., before receiving UE context information from a core network entity (e.g., AMF). During the initial phase of the RRC connection, access stratum (AS) security may not be activated. During the initial phase of the RRC connection, the base station may configure the UE to perform measurement reporting. After AS security activation is successful, the UE may send a corresponding measurement report. When AS security is activated, the UE may receive or accept a handover message (e.g., a handover command).

[0229] Upon receiving the UE context from the core network (e.g., AMF), the RAN (base station) may activate AS security (both encryption and integrity protection) using the initial security activation procedure. RRC messages (command and success response) used to activate AS security may be integrity protected, with encryption initiated after the procedure is complete. The response to the RRC message used to activate AS security may not be encrypted, while subsequent messages (e.g., for establishing SRB2 and DRBs) may be both integrity protected and encrypted. After initiating the initial AS security activation procedure, the network (e.g., base station) may initiate the establishment of SRB2 and DRBs, e.g., before receiving confirmation of the initial AS security activation from the UE. The network may apply both encryption and integrity protection to the RRC reconfiguration message used to establish SRB2 and DRBs. If the initial AS security activation and / or radio bearer establishment fails, the network shall release the RRC connection. Configurations with SRB2 without DRBs or DRBs without SRB2 may not be supported (i.e., SRB2 and at least one DRB must be configured in the same RRC reconfiguration message, and releasing all DRBs without releasing the RRC connection may not be permitted). For integrated access and backhaul mobile terminals (IAB-MTs), configurations with SRB2 but without DRBs may be supported.

[0230] The release of the RRC connection can be initiated by the network. The release procedure can be used to redirect the UE to an NR frequency or an E-UTRA carrier frequency.

[0231] The suspension of an RRC connection may be initiated by the network. When an RRC connection is suspended, the UE may store the UE inactive AS context and any configuration received from the network and transition to the RRC inactive state. The RRC message used to suspend the RRC connection may be integrity protected and encrypted.

[0232] When the UE needs to transition from the RRC Inactive state to the RRC Connected state, the resumption of the suspended RRC connection may be initiated by upper layers, by the RRC layer to perform an RNA update, or by a RAN paging from the RAN (e.g., a base station). When the RRC connection is resumed, the network may configure the UE according to the RRC Connection Resumption Procedure based on the stored UE Inactive AS Context and any RRC configuration received from the network. The RRC Connection Resumption Procedure reactivates AS security and reestablishes SRBs and DRBs.

[0233] In response to the request to resume the RRC connection, the network may resume the suspended RRC connection and cause the UE to enter / transition to the RRC connected state, or reject the resumption request and cause the UE to enter the RRC inactive state (using a wait timer), or directly re-suspend the RRC connection and cause the UE to enter RRC_INACTIVE, or directly release the RRC connection and cause the UE to enter / transition to the RRC idle state, or instruct the UE to initiate NAS-level recovery (in this case, the network sends an RRC setup message). For user data (DRB), encryption can provide user data confidentiality and integrity protection can provide user data integrity. For RRC signaling (SRB), encryption can provide signaling data confidentiality and integrity protection can provide signaling data integrity. In addition to RRC signaling, which can always be configured with integrity protection, encryption and integrity protection can also be optionally configured. Encryption and integrity protection can be configured for each DRB.

[0234] For key management and data processing, network entities or UEs handling plaintext can be protected from physical attacks and located in a secure environment. Base station (e.g., gNB or eNB) (AS) keys can be cryptographically separated from NAS (NAS) keys. Separate AS and NAS-level Security Mode Command (SMC) procedures can be used. A sequence number (COUNT) can be used as input for encryption and integrity protection, and a given sequence number can be used once for a given key on the same radio bearer in the same direction (except for retransmissions).

[0235] Keys for security may be organized and derived as follows. Keys for core network entities (e.g., AMF or keys for mobility management entity (MME)) may include KAMF (or KMME). Keys for core network entities may be keys derived by the UE's mobile equipment (ME) and security anchor function (SEAF) from keys for SEAF (KSEAF). Keys for NAS signaling may include: KNASint is a key derived by the UE's mobile equipment (ME) and the core network from keys for core network entities, which may be used to protect NAS signaling using a specific integrity algorithm; and KNASenc is a key derived by the ME and core network entity from keys for core network entities (e.g., KAMF / KMME), which may be used to protect NAS signaling using a specific encryption algorithm. Keys for base stations (e.g., gNB or eNB) may include KgNB (or KeNB), which is a key derived by the ME and core network entities (e.g., AMF / MME) from keys for core network entities (e.g., KAMF / KMME). When performing horizontal or vertical key derivation, the ME and the source base station may further derive a key for the base station. Keys for UP services may include: KUPenc is a key derived by the ME and the base station from the key for the base station, which can be used to protect the UP service between the ME and the base station using a specific encryption algorithm; KUPint may be a key derived by the ME and the base station from the key for the base station, which can be used to protect the UP service between the ME and the base station using a specific integrity algorithm. Keys for RRC signaling may include: KRRCint is a key derived by the ME and the base station from the key for the base station, which can be used to protect RRC signaling using a specific integrity algorithm; KRRCenc is a key derived by the ME and the base station from the key for the base station, which can be used to protect RRC signaling using a specific encryption algorithm. Intermediate keys may include: Next Hop Parameter (NH) is a key derived by the ME and the core network entity (e.g., AMF / MME) to provide forward security; KgNB* (or KeNB*) is a key derived by the ME and the base station when performing horizontal or vertical key derivation.

[0236] The master authentication can achieve mutual authentication between the UE and the network and provide an anchor key called KSEAF. Based on the KSEAF, keys for core network entities (such as KAMF / KMME) can be created during events such as master authentication or NAS key re-keying and key refresh. Based on the keys for the core network entities, KNASint and KNASenc can be derived when a successful NAS SMC procedure is run.

[0237] Whenever an initial AS security context needs to be established between a UE and a base station, a core network entity (e.g., AMF / MME) and the UE can derive keys and next-hop parameters (NH) for the base station (e.g., KgNB / KeNB). The keys for the base station and NH can be derived from the keys for the core network entity. A next-hop link counter (NCC) can be associated with each key and NH parameter for the base station. The key for the base station can be associated with an NCC corresponding to the NH value from which the key was derived. During initial setup, the key for the base station can be derived directly from the keys for the core network entity and then treated as associated with a virtual NH parameter with an NCC value of zero. During initial setup, the derived NH value can be associated with an NCC value of one. During handover, the basis for the base station's keys to be used between the UE and the target base station (referred to as KgNB* (or KeNB*)) can be derived from the currently active keys or NH parameters for the base station. If KgNB* (or KeNB*) can be derived from the currently active keys for the base station, this is referred to as horizontal key derivation and is indicated to the UE with a non-incremented NCC. If KgNB* (or KeNB*) is derived from the NH parameters, this derivation is called vertical key derivation and is indicated to the UE using the NCC addition. After deriving the new key for the base station, KRRCint, KRRCenc, KUPint, and KUPenc can be derived based on the key for the base station.

[0238] Based on key derivation, a base station that knows the keys for a base station shared with a UE (e.g., KgNB / KeNB) may not be able to calculate any previous KgNB that has been used between the same UE and the previous base station, thereby providing backward security. A base station that knows the keys for a base station shared with a UE may not be able to predict any future keys for the base station that will be used between the same UE and another base station after n or more handovers (because the NH parameter can only be calculated by the UE and the core network entity (e.g., AMF / MME).

[0239] The AS SMC process can be used for RRC and UP security algorithm negotiation and RRC security activation. When the AS security context is established in the base station, the AMF (or MME) can send the UE's security capabilities to the base station. The base station can select an encryption algorithm. The selected encryption algorithm can have the highest priority from its configuration list and also be present in the security capabilities. The base station can select an integrity algorithm. The selected integrity algorithm can have the highest priority from its configuration list and also be present in the security capabilities. The selected algorithm can be indicated to the UE in the AS SMC, and this message can be integrity protected. RRC downlink ciphering (encryption) at the base station can start after sending the AS SMC message. RRC uplink deciphering (decryption) at the base station can start after receiving and successfully verifying the integrity-protected AS security mode complete message from the UE. The UE can verify the validity of the AS SMC message from the base station by verifying the integrity of the received message. RRC uplink ciphering (encryption) at the UE can start after sending the AS security mode complete message. RRC downlink decryption (decryption) at the UE may begin after the AS SMC message is received and successfully verified.The RRC connection reconfiguration procedure for adding DRBs may only be performed after RRC security has been activated as part of the AS SMC procedure.

[0240] The UE may support integrity protected DRBs. In case of integrity check failure (e.g. Message Authentication Code for Integrity (MAC-I) is erroneous or missing), the associated Packet Data Unit (PDU) may be discarded by the receiving PDCP entity. Key refresh is for the key (K gNB / K eNB ), K RRC-enc , K RRC-int , K UP-enc and K UP-int It is possible and possible to combine the same radio bearer identity and the same K gNB The key reset is initiated by the base station when the key is reused together. gNB / K eNB ), K RRC-enc , K RRC-int , K UP-enc and K UP-int It is possible and can be initiated by a core network entity (e.g. AMF / MME) when an AS security context different from the currently active security context is activated.

[0241] When the UE transitions from the RRC idle state to the RRC connected state, RRC protection keys and UP protection keys may be generated, assuming that keys for NAS protection and higher layer keys are already available. These higher layer keys may have been established as a result of authentication and key agreement (AKA), or as a result of being transferred from another AMF during handover or idle mode mobility. When the UE transitions from the RRC connected state to the RRC idle state, the base station may delete the keys it has stored for the UE, so that state information for the idle mode UE only needs to be maintained in the core network entities (e.g., AMF / MME). The base station may no longer store status information about the corresponding UE and delete the current keys from its memory (for example, when the RRC connection state is transitioned to the RRC idle state): the base station and the UE may delete the NH, the keys for the base station, KgNB, KRRCint, KRRCenc, KUPint and KUPenc, and the related NCC; the core network entity (for example, AMF / MME) and the UE may save the keys for the core network entity (for example, KAMF / KMME), the stored KNASint and KNASenc.

[0242] In mobility with vertical key derivation, the NH can be further bound to the target physical cell identifier (PCI) and its frequency absolute radio frequency channel number - downlink (ARFCN-DL) before being used as the key for the base station in the target gNB. In mobility with horizontal key derivation, the current active key for the base station can be further bound to the target PCI (the PCI of the target cell) and its frequency ARFCN-DL, which is then used as the key for the base station in the target gNB. In both cases, the ARFCN-DL can be the absolute frequency of the SSB of the target primary cell (PCell). During an intra-gNB central unit (CU) handover, a change in the AS security algorithm may not be required. If the UE does not receive an indication of a new AS security algorithm during an intra-gNB-CU handover, the UE may continue to use the same algorithm as before the handover.

[0243] AS security can include integrity protection and encryption of RRC signaling (SRB) and user data (DRB). AS can apply four different security keys: security key for integrity protection of RRC signaling (KRRCint), security key for encryption of RRC signaling (KRRCenc), security key for integrity protection of user data (KUPint), and security key for encryption of user data (KUPenc). The four AS keys can be derived from the key for the base station (e.g., KgNB / KgNB). The key for the base station can be based on the key for the core network entity (KAMF / KMME), which can be processed by the upper layer (e.g., NAS layer). The integrity protection and encryption algorithms can be changed using synchronous reconfiguration (e.g., handover command). AS keys (KgNB, KRRCint, KRRCenc, KUPint, and KUPenc) can be changed during synchronous reconfiguration and when the connection is reestablished and restored. For each radio bearer, an independent counter (count) can be maintained for each direction. For each radio bearer, the count can be used as input for encryption and integrity protection.

[0244] Paging allows the base station to reach UEs in RRC idle and RRC inactive states via paging messages, notify UEs in RRC idle, RRC inactive, and RRC connected states of changes in UE system information, and notify UEs of Earthquake and Tsunami Warning System (ETWS) or Commercial Mobile Alert Service (CMAS) indications via short messages. Both paging messages and short messages can be addressed using the P-RNTI on the PDCCH. Paging messages can be sent on the PCCH, and short messages can be sent directly via the PDCCH.

[0245] When the UE is in RRC idle state, the UE may monitor the paging channel for core network (CN) initiated paging. When the UE is in RRC inactive state, the UE may monitor the paging channel for RAN initiated paging. However, the UE may not need to monitor the paging channel continuously. Paging DRX is defined as a state in which a UE in RRC idle state or RRC inactive state may only need to monitor the paging channel during one paging occasion (PO) of each DRX cycle. The paging DRX cycle may be configured by the network (e.g., a base station or a core network entity (e.g., AMF / MME)): for CN initiated paging, a default cycle may be broadcast in system information; for CN initiated paging, a UE specific cycle may be configured via NAS signaling; for RAN initiated paging, a UE specific cycle may be configured via RRC signaling; the UE may use the shortest DRX cycle among the available DRX cycles. For example, a UE in RRC idle state may use the shortest of the first two cycles mentioned above. A UE in RRC_INACTIVE may use the shortest of the three cycles mentioned above.

[0246] The PO of a UE for CN initiated paging and RAN initiated paging may be based on the same UE identity (ID), resulting in an overlap of POs for both. The number of different POs in a DRX cycle may be configured via system information, and the network may distribute the UEs to those POs based on their IDs.

[0247] When in RRC_CONNECTED, the UE may monitor the paging channel in any PO signaled in the system information for SI change indication and PWS notification. A UE in the RRC connected state may only monitor the paging channel on the active BWP configured with a common search space. For operation using shared spectrum channel access, the UE may be configured for an additional number of PDCCH monitoring opportunities in its PO to monitor for paging. When the UE detects a PDCCH transmission within a PO for a UE addressed with a P-RNTI, the UE may not need to monitor subsequent PDCCH monitoring opportunities within this PO.

[0248] The network (e.g., a base station) may initiate a paging procedure by transmitting a paging message at a paging occasion for the UE. The network may address multiple UEs within a paging message by including a paging record for each UE. The paging message may include a paging record list. The paging record list may include one or more paging records. Each paging record may include at least one of the following: a UE identifier (ID) and an access type. The UE identifier may include an S-TMSI or an I-RNTI (recovery identifier). The access type may indicate whether the paging message was initiated due to a PDU session from a non-3GPP access.

[0249] The transition from Registration Management (RM)-Deregistration ((RM)-DEREGISTERED) to RM-Registration (RM-REGISTERED), from CM-IDLE to CM-Connected (CM-CONNECTED), and from CM-CONNECTED to CM-IDLE may require cell selection. In the RM-DEREGISTERED state, the UE may not be registered with the network. The UE context in the core network entity (e.g., AMF / MME) may not store valid location or routing information for the UE. The UE may not be accessible by the AMF. In the RM-REGISTERED state, the UE is registered with the network. In the RM-REGISTERED state, the UE can receive services that require registration with the network. A UE in the CM-IDLE state may not have a NAS signaling connection established with a core network entity (e.g., AMF / MME) (e.g., via the N1 / S1 interface). The UE can perform cell selection / cell reselection and PLMN selection. A UE in the CM-CONNECTED state may have a NAS signaling connection with a core network entity (e.g., via an N1 / S1 interface). The NAS signaling connection may use an RRC connection between the UE and a base station (e.g., a RAN) and a Next Generation Application Protocol (NGAP) / S1AP UE association between an access network (AN) (e.g., a base station's AN) and a core network entity (e.g., an AMF / MME).

[0250] Cell selection can be based on the following principles. The UE NAS layer can identify the selected PLMN and equivalent PLMNs. Cell selection can be based on the Cell Definition SSB (CD-SSB) located on the synchronization raster: the UE can search the frequency (NR) band and, for each carrier frequency, can identify the strongest cell based on the CD-SSB. The UE can then read the cell system information broadcast to identify its PLMN: the UE can search each carrier in turn ("initial cell selection") or use stored information to shorten the search ("stored information cell selection"). The UE can seek to identify a suitable cell; if the UE is unable to identify a suitable cell, it can seek to identify an acceptable cell. When a suitable cell is found, or only an acceptable cell is found, the UE can camp on that cell and begin the cell reselection process: a suitable cell is a cell where: the measured cell attributes meet the cell selection criteria; the cell PLMN is the selected PLMN, a registered PLMN, or an equivalent PLMN; the cell is not barred or reserved, and the cell is not part of a tracking area in the "prohibited tracking area for roaming" list; an acceptable cell is a cell where the measured cell attributes meet the cell selection criteria and is not barred.

[0251] When transitioning from the RRC Connected state or the RRC Inactive state to the RRC Idle state, the UE may camp on a cell selected based on the frequency assigned by the RRC in the state transition message. The UE may attempt to find a suitable cell in the manner described above for stored information or initial cell selection. If no suitable cell is found on any frequency or RAT, the UE may attempt to find an acceptable cell. In multi-beam operation, cell quality may be derived between beams corresponding to the same cell.

[0252] A UE in RRC Idle may perform cell reselection. The principles of the procedure are as follows. Cell reselection may be based on the CD-SSB located on the synchronization raster. The UE may measure properties of the serving cell and neighboring cells to enable the reselection procedure: For search and measurement of inter-frequency neighboring cells, the carrier frequency needs to be indicated. Cell reselection may identify the cell on which the UE should camp. Cell reselection may be based on cell reselection criteria involving measurements of the serving cell and neighboring cells: intra-frequency reselection is based on ranking of cells; inter-frequency reselection is based on absolute priority, where the UE attempts to camp on the highest priority frequency available; a neighbor cell list (NCL) may be provided by the serving cell to handle specific cases of intra-frequency and inter-frequency neighboring cells; a blacklist may be provided to prevent the UE from reselecting to specific intra-frequency and inter-frequency neighboring cells; a whitelist may be provided to request the UE to reselect only to specific intra-frequency and inter-frequency neighboring cells; cell reselection may be speed dependent; service specific priorities. In multi-beam operation, cell quality may be derived between beams corresponding to the same cell.

[0253] The UE may perform one of two processes, such as initial cell selection and cell selection by utilizing stored information. When the UE has not yet stored cell information for the selected PLMN, the UE may perform initial cell selection. Otherwise, the UE may perform cell selection by utilizing stored information. For initial cell selection, the UE may scan all RF channels in the (NR) frequency band based on its ability to find a suitable cell. Based on the results of the scan, the UE may search for the strongest cell on each frequency. The UE may select a cell as a suitable cell. For cell selection by utilizing stored information, the UE may require stored frequency information, and optionally information about cell parameters from previously received measurement control information elements or from previously detected cells. Based on the stored information, if the UE finds a suitable cell, the UE may search for a suitable cell and select a suitable cell. If the UE does not find a suitable cell, the UE may perform initial cell selection.

[0254] The base station may configure cell selection criteria for cell selection. The UE may seek to identify cells suitable for cell selection. A suitable cell is one that satisfies the following conditions: (1) the measured cell attributes satisfy the cell selection criteria, (2) the cell PLMN is the selected PLMN, a registered or equivalent PLMN, (3) the cell is not barred or reserved, and (4) the cell is not part of a tracking area in the "roaming prohibited tracking area" list. The RRC layer in the UE may inform the NAS layer in the UE of cell selection and reselection results based on changes in received system information related to the NAS. For example, the cell selection and reselection results may be a cell identity, a tracking area code, and a PLMN identity.

[0255] The UE-RRC layer may initiate an RRC connection establishment procedure, an RRC connection recovery procedure, or an RRC connection re-establishment procedure. Based on initiating an RRC connection establishment procedure or an RRC connection recovery procedure, the UE may perform one or more procedures, wherein the one or more procedures include at least one of the following: performing a unified access control procedure (e.g., access barring check) for an access attempt of an RRC establishment / recovery procedure on a serving cell; applying default configuration parameters and configuration / parameters provided by SIB1 (e.g., applying the default configuration and configuration / parameters provided by SIB1 based on an allowed access attempt); performing, for example, sending a random access preamble to a serving cell based on an allowed access attempt; sending an RRC request message to a serving cell (e.g., sending an RRC request message to serving cell 0 based on determining that a random access response is successfully received; starting a timer based on sending the RRC request message; receiving an RRC response message or an RRC reject message from the serving cell (e.g., in response to the RRC request message); or sending an RRC complete message (e.g., sending an RRC complete message in response to receiving an RRC response message). For an RRC connection reestablishment procedure, the UE may not perform a unified access procedure (e.g., access barring check) for an access attempt of an RRC reestablishment procedure.

[0256] Base stations (e.g., NG-RAN) can support overload and access control functions such as RACH backoff, RRC connection rejection, RRC connection release, and UE-based access barring mechanisms. A unified access control framework applies to all UE states (e.g., RRC idle, inactive, and connected). The base station can broadcast barring control information associated with the access class and access identity (in the case of network sharing, the barring control information can be set separately for each PLMN). The UE can determine whether the access attempt is authorized based on the barring information broadcast for the selected PLMN, the selected access class, and the access identity of the access attempt. For NAS-triggered requests, the UE-NAS layer can determine the access class and access identity. For AS-triggered requests, the UE-RRC layer determines the access class, while the NAS determines the access identity. The base station can process access attempts with the high-priority establishment causes "emergency," "MPS priority access," and "MCS priority access" (i.e., emergency call, MPS, MCS subscribers) and respond to these access attempts with RRC rejection only under extreme network load conditions that may threaten base station stability.

[0257] Based on initiating the RRC connection establishment procedure or the RRC connection recovery procedure, the UE in the RRC inactive or idle state may perform or initiate an access barring check (or unified access control procedure) for the access attempt of the RRC connection establishment procedure or the RRC connection recovery procedure. Based on performing or initiating the access barring check, the UE may determine the access category and access identity of the access attempt. The UE may determine that the access attempt is prohibited based on at least one of the following: timer T309 is running for the access category of the access attempt; and timer T302 is running and the access category is neither '2' nor '0'. The UE may determine the allowed access attempt based on at least one of the following: the access category is '0'; and the system information block (system information block type 25) including the unified access control (UAC) barring parameter is not broadcast by the serving cell. The UE may determine that the access attempt is barred based on at least one of the following: the establishment cause (e.g., for the access attempt) is not an emergency; the access barring per RSRP parameter of the system information block includes (or is set to) a threshold of 0, and the wireless device is in enhanced coverage; the access barring per RSRP parameter of the system information block includes (or is set to) a threshold of 1, and the measured RSRP is less than the first entry in the RSRP threshold PRACH information list; the per RSRP access barring parameter of the system information block includes (or is set to) a threshold of 2, and the measured RSRP is less than the second entry in the RSRP threshold PRACH information list; and the access barring per RSRP parameter of the system information block includes (or is set to) a threshold of 3, and the measured RSRP is less than the third entry in the RSRP threshold PRACH information list.

[0258] The UE may determine that the access attempt is allowed based on that the system information block does not include the UAC barring parameter for the access attempt. For example, the UE may determine that the access attempt is allowed based on that the system information block does not include the UAC barring parameter of the PLMN selected by the UE and the common UAC barring parameter. The UE may determine that the access attempt is allowed based on that the common UAC barring parameter does not include the access category of the access attempt. The UAC barring parameter may include at least one of the following: a UAC barring parameter per PLMN; and a UAC barring parameter. The UE may perform an access barring check on the access category of the access attempt based on the UAC barring parameter in the system information block. The UE may determine that the access attempt is allowed based on that the corresponding bit of at least one access identifier in the access identifier in the UAC barring parameter is zero. The UE may extract a first random number uniformly distributed within a range, where the range is greater than or equal to 0 and less than 1.

[0259] The UE may determine that the access attempt is allowed based on that the first random number is lower than the UAC prohibition factor in the UAC prohibition parameter. The UE may determine that the access attempt is prohibited based on that the first random number is greater than the UAC prohibition factor in the UAC prohibition parameter. In response to determining that the access attempt is prohibited, the UE may extract a second random number uniformly distributed within a range, where the range is greater than or equal to 0 and less than 1. The UE may start a prohibition timer T309 for the access category based on the second random number. While the prohibition timer T309 is running, the access attempt associated with the access category is prohibited (e.g., transmission is not allowed). Based on the expiration of the prohibition timer T309, the UE may consider that the prohibition of the access category is relieved. Based on the prohibition of the access category being relieved, if the UE has an access attempt to the access category, the UE may perform an access prohibition check for the access category.

[0260] Upon initiating the RRC connection re-establishment procedure, if one or more inhibit timers T309 are running, the UE may stop the one or more inhibit timers T309 for all access classes. Based on stopping the one or more inhibit timers T309, the UE may determine that barring for all access classes is being alleviated. The UE may perform the RRC connection re-establishment procedure based on barring being alleviated for all access classes. For example, based on barring being alleviated for all access classes, the UE may send an RRC re-establishment request without barring.

[0261] In order to initiate the RRC connection establishment / recovery / re-establishment process, the UE-RRC layer may use the parameters in the received SIB1. The UE-RRC layer may use the L1 parameter value and time alignment timer in SIB1. The UE-RRC layer may use the UAC prohibition information in SIB1 to perform a unified access control process. Based on the unified access control process, the UE-RRC layer may determine whether the access attempts of these RRC processes are prohibited or allowed. Based on determining that the access attempt is allowed, the UE-RRC layer may determine to send an RRC request message to the base station, where the RRC request message may be an RRC establishment request message, an RRC recovery request message, or an RRC reconstruction message. The UE-NAS layer may or may not provide the S-TMSI as the UE identity. The UE-RRC layer may set the UE identity in the RRC request message.

[0262] For the RRC setup request message, the UE in the RRC idle state can initiate the RRC connection establishment process. Based on the initiation of the RRC connection establishment process, if the UE-NAS layer provides the S-TMSI, the UE-RRC layer in the RRC idle state can set the UE identity to the S-TMSI. Otherwise, the UE-RRC layer in the RRC idle state can extract a 39-bit random value and set the UE identity to the random value. For the RRC recovery request message, the UE-RRC layer in the RRC inactive or idle state can set the UE identity to the restored stored identity. For the RRC re-establishment request message, the UE-RRC layer in the RRC connected state can set the UE identity to the C-RNTI used in the source PCell. The UE-NAS layer can provide the establishment cause (e.g., the UE-NAS layer). The UE-RRC layer can set the establishment cause of the RRC request message.

[0263] For the RRC recovery request message, a UE in RRC inactive may initiate an RRC connection recovery procedure. A UE in an RRC idle state with a suspended RRC connection may initiate an RRC connection recovery procedure. A UE in an RRC inactive state or an RRC idle state may initiate an RRC connection procedure based on at least one of: resuming (suspending) the RRC connection; and performing / initiating UP small data transmission. Based on initiating the RRC connection recovery procedure, the UE-RRC layer may recover the stored configuration parameters and the stored security keys from the stored UE inactive AS context. Based on the security key, the UE-RRC layer in an RRC inactive or idle state may set the recovery MAC-I value to the 16 least significant bits of the MAC-I calculated based on the variable recovery MAC input, the security key for integrity protection of the RRC layer in the UE inactive AS context, the previously configured integrity protection algorithm, and other security parameters (e.g., count, bearer, and direction). The variable resumption MAC input may include at least one of the following: a physical cell identifier of the source cell; a C-RNTI of the source cell; and a cell identifier of the target cell (e.g., the selected cell), wherein the cell identifier is a cell identifier in a system information block (e.g., SIB1) of the target cell (e.g., the selected cell). Based on the security key and the next hop link count (NCC) value, the UE-RRC layer in an RRC inactive or idle state derives new security keys for integrity protection and encryption and configures lower layers (e.g., the UE-PDCP layer) to apply them. The UE may have a stored NCC value and a resumption identifier. The UE may receive an RRC release message with a suspension indication (or suspension configuration parameters), wherein the RRC release message includes at least one of the following: a resumption identifier; and an NCC value. The UE-RRC layer in an RRC inactive or idle state may re-establish a PDCP entity for one or more bearers. The UE-RRC layer may resume one or more bearers. For example, based on resuming the RRC connection, the UE-RRC layer may resume SRB1. Based on the UP small data transmission, the UE-RRC layer may restore one or more SRBs and DRBs. The UE-RRC layer in the RRC inactive or idle state may send an RRC recovery request message to the base station, where the RRC recovery request message may include at least one of the following: a recovery identifier; a recovery MAC-I; and a recovery reason.

[0264] For the RRC reestablishment request message, the UE in the RRC connected state may initiate an RRC connection reestablishment procedure. Based on initiating the RRC connection reestablishment procedure, the UE-RRC layer in the RRC connected state may include the physical cell identifier and short MAC-I of the source PCell in the RRC reestablishment message. The UE-RRC layer in the RRC connected state may set the short MAC-I to the 16 least significant bits of the MAC-I calculated based on the variable short MAC input, the security key and integrity protection algorithm of the RRC layer (which is used in the source PCell or the PCell in which the reestablishment trigger occurs), and other security parameters (e.g., count, bearer, and direction). The variable short MAC input may include at least one of the following: the physical cell identifier of the source cell; the C-RNTI of the source cell; and the cell identifier of the target cell (e.g., the selected cell), wherein the cell identifier is the cell identifier in the system information block (e.g., SIB1) of the target cell (e.g., the selected cell). The UE-RRC layer in the RRC connected state may reestablish the PDCP entity and the RLC entity for SRB1 and apply the default SRB1 configuration parameters for SRB1. The UE-RRC layer in the RRC connected state may configure the lower layer (eg, the PDCP layer) to suspend integrity protection and ciphering of SRB1 and resume SRB1.

[0265] The UE-RRC layer may send an RRC request message to a lower layer (eg, PDCP layer, RLC layer, MAC layer, and / or PHY layer) for transmission, where the RRC request message may be an RRC setup request message, an RRC recovery request message, or an RRC re-establishment message.

[0266] The UE-RRC layer may receive an RRC setup message in response to an RRC recovery request message or an RRC re-establishment request message. Based on the RRC setup message, the UE-RRC layer may discard any stored AS context, suspended configuration parameters, and current AS security context. The UE-RRC layer may release the radio resources of all established RBs except SRB0, including releasing the associated PDCP entity and SDAP RLC entity. The UE-RRC layer may release the RRC configuration except for the default L1 parameter value, the default MAC cell group configuration, and the CCCH configuration. The UE-RRC layer may indicate the fallback of the RRC connection to the upper layer (e.g., the NAS layer). If the timer T380 is running as a periodic RAN-based notification area (RNA) update timer, the UE-RRC layer may stop the timer T380.

[0267] The UE-RRC layer may receive an RRC setup message in response to an RRC setup request message, an RRC resume request message, or an RRC reestablishment request message. The RRC setup message may include cell group configuration parameters and radio bearer configuration parameters. The radio bearer configuration parameters may include at least one of signaling bearer configuration parameters, data radio bearer configuration parameters, and / or security configuration parameters. The security configuration parameters may include security algorithm configuration parameters and a key usage indication indicating whether the radio bearer configuration parameters use a primary key or a secondary key. The signaling radio bearer configuration parameters may include one or more signaling radio bearer configuration parameters. Each signaling radio configuration parameter may include at least one of an SRB identifier, a PDCP configuration parameter, a reestablishment PDCP indication, and / or a discard PDCP indication. The data radio bearer configuration parameters may include one or more data radio bearer configuration parameters. Each data radio configuration parameter may include at least one of a DRB identifier, a PDCP configuration parameter, a SDAP configuration parameter, a reestablishment PDCP indication, and / or a restoration PDCP indication. The radio bearer configuration in the RRC setup message may include signaling radio configuration parameters for SIB1. Based on the RRC setup message, the UE-RRC layer may establish SRB1. Based on the RRC Setup message, the UE-RRC layer may perform cell group configuration or radio bearer configuration. The UE-RRC layer may stop the inhibit timer and wait timer to facilitate the cell sending the RRC Setup message. Upon receiving the RRC Setup message, the UE-RRC layer may perform one or more of the following: transition to the RRC Connected state; terminate the cell reselection process; treat the current cell sending the RRC Setup message as a PCell; and / or send an RRC Setup Complete message by setting the content of the RRC Setup Complete message.

[0268] The UE-RRC layer may receive an RRC resume message in response to the RRC resume request message. Based on the RRC resume message, the UE-RRC layer may discard the UE inactive AS context and release the suspension configuration parameters except the RNA notification area information. The RRC resume message may include at least one of the following: radio bearer configuration parameters; cell group configuration parameters; measurement configuration parameters; sk counter for AS security; a first indication requesting idle / inactive measurement results; a second indication for restoring the secondary cell (SCell) of the primary cell group (MCG); a third indication for restoring the secondary cell group (SCG); and SCG configuration parameters; based on the RRC resume message, the UE-RRC layer may perform a process for configuring or restoring configuration parameters (e.g., cell group configuration, radio bearer configuration, and / or SCG configuration); a security key update process; and / or a measurement (configuration) process. Based on receiving the RRC recovery message, the UE-RRC layer can perform one or more of the following: indicate to the upper layer (e.g., the NAS layer) that the suspended RRC connection has been resumed; resume SRB2, all DRBs, and measurements; enter the RRC connected state; stop the cell reselection process; regard the current cell sending the RRC recovery message as a PCell or / and send an RRC recovery complete message by setting the content of the RRC recovery complete message.

[0269] The cell group configuration parameter can be used to configure a primary cell group (MCG) or a secondary cell group (SCG). If the cell group configuration parameter is used to configure the MCG, the cell group configuration parameter is a primary cell group configuration parameter. If the cell group configuration parameter is used to configure the SCG, the cell group configuration parameter is a secondary cell group configuration parameter. The cell group includes a MAC entity, a logical channel with an associated RLC entity and a set of a primary cell (SpCell) and one or more secondary cells (SCells). The cell group configuration parameter (e.g., a primary cell group configuration parameter or a secondary cell group configuration parameter) may include at least one of the RLC bearer configuration parameters of the cell group, the MAC cell group configuration parameter of the cell group, the physical cell group configuration parameter of the cell group, the SpCell configuration parameter of the cell group, or the SCell configuration parameter of the cell group. The MAC cell group configuration parameter may include MAC parameters of the cell group, wherein the MAC parameters may include at least DRX parameters. The physical cell group configuration parameter may include cell group-specific L1 (Layer 1) parameters.

[0270] The special cell (SpCel) may include a primary cell (PCell) of an MCG or a primary SCG cell (PSCell) of an SCG. The SpCell configuration parameters may include serving cell-specific MAC and PHY parameters of the SpCell. The MR-DC configuration parameters may include at least one of SRB3 configuration parameters, measurement configuration parameters of the SCG, and SCG configuration parameters.

[0271] The cell group configuration parameters may include at least one of the RLC bearer configuration parameters of the first cell group, the MAC cell group configuration parameters, the physical cell group configuration parameters, the SpCell configuration parameters or the SCell configuration parameters of other cells of the second base station. The SpCell configuration parameters may include at least one of the radio link failure timer and constraints, the radio link monitoring in the synchronization-out-of-synchronization threshold and / or the serving cell configuration parameters of the first cell. The serving cell configuration parameters may include at least one of the following: downlink BWP configuration parameters; uplink configuration parameters; uplink configuration parameters of the supplementary uplink carrier (SUL); PDCCH parameters applicable to all BWPs of the serving cell; PDSCH parameters applicable to all BWPs of the serving cell; CSI measurement configuration parameters; SCell deactivation timer; cross-carrier scheduling configuration parameters of the serving cell; timing advance group (TAG) identification (ID) of the serving cell; path loss reference link, indicating whether the UE should use the downlink of the SpCell or the SCell as the path loss reference for the uplink; serving cell measurement configuration parameters; channel access configuration parameters of the access procedure of the shared spectrum channel access operation;

[0272] The CSI measurement configuration parameters may be the configuration of the CSI-RS (reference signal) belonging to the serving cell, the configuration of the channel state information report of the CSI-RS (reference signal) belonging to the serving cell, and the channel state information report on the PUSCH triggered by the DCI received on the serving cell.

[0273] In an example, downlink BWP configuration parameters may be used to configure dedicated (UE-specific) parameters for one or more downlink BWPs. The one or more downlink BWPs may include at least one of an initial downlink BWP, a default downlink BWP, and a first active downlink BWP. The downlink BWP configuration parameters may include at least one of the following: configuration parameters for the one or more downlink BWPs; one or more downlink BWP IDs for the one or more downlink BWPs; and a BWP inactivity timer. The downlink BWP configuration parameters may include at least one of the following: PDCCH configuration parameters for the downlink BWP; PDSCH configuration parameters for the downlink BWP; semi-persistent scheduling (SPS) configuration parameters for the downlink BWP; beam failure recovery SCell configuration parameters for candidate RSs; and / or radio link monitoring configuration parameters for detecting cell and beam radio link failure opportunities for the downlink BWP. The one or more downlink BWP IDs may include at least one of an initial downlink BWP ID, a default downlink BWP identification (ID), and a first active downlink BW PID.

[0274] In an example, the uplink configuration parameters may be uplink configuration parameters for a normal uplink carrier (not a supplementary uplink carrier). The uplink configuration parameters (or uplink configuration parameters for a SUL) may be used to configure dedicated (UE-specific) parameters for one or more uplink BWPs. The one or more uplink BWPs may include at least one of an initial uplink BWP and a first active uplink BWP. The uplink BWP configuration parameters may include at least one of the following: configuration parameters for the one or more uplink BWPs; one or more uplink BWP IDs for the one or more uplink BWPs; PUSCH parameters that are common across the BWPs of the UEs in the serving cell; SRS carrier switching information; and power control configuration parameters. The configuration parameters for the uplink BWP may include at least one of the following: one or more PUCCH configuration parameters for the uplink BWP; PUSCH configuration parameters for the uplink BWP; one or more configured uplink grant configuration parameters for the uplink BWP; SRS configuration parameters for the uplink BWP; beam failure recovery configuration parameters for the uplink BWP; and / or cyclic prefix (CP) extension parameters for the uplink BWP.

[0275] The one or more uplink BWP IDs may include at least one of an initial uplink BWP ID (e.g., initial uplink BWP ID = 0) and / or a first active uplink BWP ID. The SRS carrier switching information may be used to configure SRS carrier switching when the PUSCH is not configured, as well as SRS power control independent of the PUSCH. The power control configuration parameters may include at least one of a PUSCH power control configuration parameter, a PUCCH power configuration control parameter, and an SRS power control parameter.

[0276] The UE-RRC layer in the RRC inactive or idle state may receive an RRC reject message in response to an RRC setup request message or an RRC resume request message. The RRC reject message may include a waiting timer. Based on the waiting timer, the UE-RRC layer may start timer T302, where the timer value is set to the waiting timer. Based on the RRC reject message, the UE-RRC layer may notify the upper layer (e.g., the UE-NAS layer) about the failure to set up the RRC connection or restore the RRC connection. The UE-RRC layer may reset the MAC and release the default MAC cell group configuration. Based on the RRC reject received in response to a request from the upper layer, the UE-RRC layer may notify the upper layer (e.g., the NAS layer) that access barring applies to all access categories except categories '0' and '2'.

[0277] The UE-RRC layer in the RRC Inactive or Idle state may receive an RRC Reject message in response to the RRC Resume Request message. Based on the RRC Reject message, the UE-RRC layer may discard the current security keys. The UE-RRC layer may resuspend the RRC connection. If the resumption was triggered due to an RNA update, the UE-RRC layer may set the pending RNA update value to true.

[0278] The UE-RRC layer in the RRC inactive or idle state may perform a cell (re)selection procedure while performing an RRC procedure to establish an RRC connection. Based on cell selection or cell reselection, the UE-RRC layer may change the cell on which the UE resides and stop the RRC procedure. The UE-RRC layer may notify upper layers (e.g., the NAS layer) of the failure of the RRC procedure.

[0279] A UE in an RRC connected state may detect a connection failure with a base station. The UE in an RRC connected state may activate AS security with the base station before detecting the failure. The failure includes at least one of the following: a radio link failure (RLF), a synchronization reconfiguration failure, a mobility failure from New Radio (NR), an integrity check failure indication from a lower layer (e.g., a PDCP layer) on a signaling radio bearer 1 (SRB1) or a signaling radio bearer 2 (SRB2), or an RRC connection reconfiguration failure.

[0280] The radio link failure may be a radio link failure of a primary cell of the base station. The base station may send a synchronized reconfiguration to the UE in the RRC connected state in an RRC message. The synchronized reconfiguration may include a reconfiguration timer (e.g., T304). Based on receiving the synchronized reconfiguration, the UE may start the reconfiguration timer and perform synchronized reconfiguration (e.g., handover). Based on the expiration of the reconfiguration timer, the UE determines that the reconfiguration synchronization has failed. The base station may send a mobility from NR command message to the UE in the RRC connected state. Based on receiving the mobility from NR command message, the UE may perform a handover from NR to a cell using another RAT (e.g., E-UTRA). The UE may determine a mobility failure from NR based on satisfying at least one of the conditions: if the UE does not successfully establish a connection to the target radio access technology; or if the UE cannot comply with any part of the configuration included in the mobility from NR command message; or if there is a protocol error in the inter-RAT information included in the mobility from NR message.

[0281] Based on the detection of the failure, the UE in the RRC connected state may initiate an RRC connection reestablishment procedure. Based on the initiation of the RRC connection reestablishment procedure, the UE may start timer T311, suspend all radio bearers except SRB0, and reset the MAC (layer). Based on the initiation of the RRC connection reestablishment procedure, the UE in the RRC connected state may release the MCG SCell, release the special cell (SpCell) configuration parameters, and the multi-radio dual connectivity (MR-DC) related configuration parameters. For example, based on the initiation of the RRC connection reestablishment procedure, the UE may release the primary cell group configuration parameters.

[0282] Upon initiating the RRC connection reestablishment procedure, the UE in the RRC connected state may perform a cell selection procedure. Based on the cell selection procedure, the UE may select a cell based on the cell's signal quality exceeding a threshold. The UE in the RRC connected state may select a cell based on the cell's signal quality exceeding a threshold. The UE may determine, based on the cell selection procedure, that the selected cell exceeds the threshold. Signal quality includes at least one of the following: reference signal received power; received signal strength indicator; reference signal received quality; or signal to interference plus noise ratio.

[0283] Based on selecting an appropriate cell, the UE in the RRC connected state may stop timer 311 and start timer T301. Based on selecting an appropriate cell, the UE in the RRC connected state may stop the prohibition timer T390 for all access categories. Based on stopping the prohibition timer T390, the UE in the RRC connected state may consider mitigating the prohibition of all access categories for the cell. Based on selecting a cell, the UE in the RRC connected state may apply default L1 parameter values ​​in addition to the parameters provided in SIB1, apply the default MAC cell group configuration, apply the CCCH configuration, apply the timer alignment timer in SIB1, and initiate transmission of an RRC re-establishment request message.

[0284] A UE in an RRC connected state may stop timer T301 upon receipt of an RRC response message in response to an RRC reestablishment request message. The RRC response message may include at least one of an RRC reestablishment message, an RRC setup message, or an RRC reestablishment reject message. If the selected cell becomes unsuitable, the UE in an RRC connected state may stop timer T301.

[0285] Based on the cell selection procedure triggered by initiating the RRC connection reestablishment procedure, the UE in the RRC connected state may select an inter-RAT cell. Based on the selection of the inter-RAT cell, the UE in the RRC connected state (UE-AS layer) may transition to the RRC IDLE state and may provide the release cause 'RRC connection failure' to the upper layer of the UE (UE-NAS layer).

[0286] Upon initiating transmission of the RRC Reestablishment Request message, the UE in the RRC Connected state may send an RRC Reestablishment Request message. The RRC Reestablishment Request message may include at least one of the C-RNTI used in the source PCell, the Physical Cell Identity (PCI) of the source PCell, a short MAC-I, or a reestablishment cause. The reestablishment cause may include at least one of a reconfiguration failure, a handover failure, or other failures.

[0287] Based on initiating transmission of the RRC re-establishment request message, the UE in the RRC connected state (RRC layer) may re-establish PDCP for SRB1, re-establish RLC for SRB1, apply the default SRB configuration for SRB1, configure the lower layer (PDCP layer) to suspend integrity protection and ciphering for SRB1, resume SRB1, and submit the RRC re-establishment request message to the lower layer (PDCP layer) for transmission. Based on submitting the RRC re-establishment request message to the lower layer, the UE in the RRC connected state may send the RRC re-establishment request message to the target base station via the cell selected based on the cell selection process, where the target base station may or may not be the source base station.

[0288] Upon expiration of timer T311 or T301, the UE (UE-AS layer) may transition to the RRC idle state and may provide a release cause 'RRC connection failure' to an upper layer of the UE (UE-NAS layer).

[0289] Upon receiving the release cause "RRC Connection Failure", the UE in RRC Idle state (UE-NAS layer) may perform the NAS signaling connection restoration procedure when the UE has no pending signaling and user data pending. Upon performing the NAS signaling connection restoration procedure, the UE in RRC Idle state may initiate a registration procedure by sending a Registration Request message to the AMF.

[0290] Upon receiving the release cause "RRC Connection Failure", the UE in RRC Idle state (UE-NAS layer) may perform a Service Request procedure by sending a Service Request message to the AMF when the UE has pending signalling or pending user data.

[0291] Upon receiving the RRC Reestablishment Request message, the target base station may check whether the UE context of the UE is locally available. If the UE context is not locally available, the target base station may perform a UE context retrieval procedure by sending a Retrieve UE Context Request message to the source base station (last serving base station) of the UE.

[0292] For the RRC connection reestablishment procedure, the retrieve UE context request message may include at least one of a UE context ID, an integrity protection parameter, or a new cell identifier. The UE context ID may include at least one of the following: the C-RNTI containing the RRC reestablishment request message; and the PCI of the source PCell (the last serving PCell). The integrity protection parameter for the RRC reestablishment procedure may be a short MAC-I. The new cell identifier may be an identifier of a target cell, where the target cell is the cell for which the RRC connection reestablishment has been requested. The new cell identifier is a cell identifier in a system information block (e.g., SIB1) of the target cell (e.g., the selected cell).

[0293] For the RRC connection reestablishment procedure, upon receiving the Retrieve UE Context Request message, the source base station may check the Retrieve UE Context Request message. If the source base station is able to identify the UE context using the UE Context ID and successfully authenticate the UE using the integrity protection included in the Retrieve UE Context Request message, and decides to provide the UE context to the target base station, the source base station may respond to the target base station with a Retrieve UE Context Response message. If the source base station cannot identify the UE context using the UE Context ID, or if the integrity protection included in the Retrieve UE Context Request message is not valid, the source base station may respond to the target base station with a Retrieve UE Context Failure message.

[0294] For the RRC connection reestablishment procedure, the Retrieve UE Context Response message may include at least one of the Xn Application Protocol (XnAP) ID of the target base station, the XnAP ID of the source base station, a Globally Unique AMF Identifier (GUAMI), or UE context information (e.g., UE Context Information Retrieve UE Context Response). The UE context information may include at least one of an NG-C UE associated signaling reference, UE security capabilities, AS security information, UE aggregate maximum bit rate, a list of PDU sessions to be set, an RRC context, a mobility restriction list, or an index to a RAT / frequency selection priority. The NG-C UE associated signaling reference may be an NG Application Protocol ID allocated at the AMF of the UE on the NG-C connection with the source base station. The AS security information may include a security key (K gNB ) and next hop link count (NCC) value. The PDU session list to be set may include PDU session resource related information used at the UE context in the source base station. The PDU session resource related information may include a PDU session ID, a PDU session resource aggregated maximum bit rate, a security indication, a PDU session type, or a QoS flow list to be set. The security indication may include a user plane integrity protection indication and a confidentiality protection indication, which respectively indicate the requirements for user plane (UP) integrity protection and encryption for the corresponding PDU session. The security indication may also include an indication of whether UP integrity protection is applied to the PDU session, an indication of whether UP encryption is applied to the PDU session, and at least one of the maximum integrity protection data rate values ​​(uplink and downlink) for each UE of the integrity-protected DRB. The PDU session type may indicate at least one of Internet Protocol version 4 (IPv4), IPv6, IPv4v6, Ethernet, or unstructured. The QoS flow list to be set may include at least one of a QoS flow identifier, a QoS flow level QoS parameter (QoS parameter to be applied to the QoS flow), or a bearer identifier.

[0295] For the RRC connection reestablishment process, the UE context retrieval failure message may include at least the XnAP ID of the target base station and a cause value.

[0296] For the RRC connection reestablishment process, upon receiving the retrieve UE context response message, the target base station may send an RRC reestablishment message to the UE. The RRC reestablishment message may include at least a network hop connection count (NCC) value.

[0297] Upon receiving the RRC re-establishment message, the UE may re-establish the NCC value based on the current K value associated with the NCC value. gNB or next hop (NH) parameters to derive the new security key (K gNBBased on the new security key of the base station and the previously configured integrity protection algorithm, the UE can derive the security key (K RRCint ) and the security key (K UPint Based on the new security key of the base station and the previously configured encryption algorithm, the UE can derive the security key (K RRCenc ) and the security key (K UPenc ). Based on K RRCint and the previously configured integrity protection algorithm, the UE can verify the integrity protection of the RRC re-establishment message. Based on the verification failure, the UE (UE-AS layer) can enter the RRC IDLE state and provide the release reason "RRC connection failure" to the upper layer of the UE (UE-NAS layer). Based on the verification success, the UE can be configured to be based on the previously configured integrity protection algorithm and K RRCint To restore the integrity protection of SRB1, and configure it based on the previously configured encryption algorithm and K RRCenc To restore the encryption of SRB1. The UE can send an RRC re-establishment complete message to the target base station.

[0298] Upon receiving the UE context retrieval failure message, the target base station may send an RRC release message to the UE. For example, upon receiving the UE context retrieval failure message including an RRC release message, the target base station may send an RRC release message to the UE. Upon receiving the UE context retrieval failure message, the target base station may send an RRC setup message or an RRC reject message. Upon receiving the UE context retrieval failure message, the target base station may not send any response message to the UE.

[0299] Figure 17 An example of an RRC connection reestablishment procedure is shown. A UE in an RRC connected state may send and receive data to and from a first base station (e.g., a source base station) via a cell, wherein the cell includes a primary cell (PCell) of the first base station. The UE may detect a failure in the connection with the first base station. Based on the failure, the UE may initiate an RRC reestablishment procedure.

[0300] exist Figure 17In the example, based on initiating the RRC connection reestablishment process, the UE may start timer T311, suspend all radio bearers except SRB0, and / or reset the MAC (layer). Based on initiating the RRC connection reestablishment process, the UE may release the MCG SCell, release the special cell (SpCell) configuration parameters and the multi-radio dual connection (MR-DC) related configuration parameters. Based on initiating the RRC connection reestablishment process, the UE may perform a cell selection process. Based on the cell selection process, the UE may select cell 2 of a second base station (e.g., a target base station), where cell 2 is a suitable cell. Based on selecting a suitable cell, the UE may stop timer T311 and start timer T301. Based on selecting a suitable cell, if one or more prohibition timers T309 are running, the UE may stop one or more prohibition timers T309 for all access categories. Based on stopping one or more prohibition timers T309, the UE may consider alleviating the prohibition of all access categories for that cell. Based on the selected cell, the UE may apply default L1 parameter values ​​in addition to the parameters provided in SIB1, apply default MAC cell group configuration, apply CCCH configuration, apply timer alignment timers in SIB1, and initiate transmission of an RRC re-establishment request message.

[0301] exist Figure 17 In the example of , the RRC re-establishment message may include at least one of the C-RNTI used in the source PCell (e.g., cell 1), the physical cell identity (PCI) of the source PCell, a short MAC-I, or a re-establishment cause. Based on initiating the transmission of the RRC re-establishment request message, the UE (RRC layer) may re-establish the PDCP of SRB1, re-establish the RLC of SRB1, apply the default SRB configuration of SRB1, configure the lower layer (PDCP layer) to suspend integrity protection and ciphering of SRB1, resume SRB1 and submit the RRC re-establishment request message to the lower layer (PDCP layer) for transmission. Based on initiating the transmission of the RRC re-establishment request message, the UE may send an RRC re-establishment request message to the second base station via cell 2.

[0302] exist Figure 17In the example, based on receiving the RRC re-establishment request message, the second base station may check whether the UE context of the UE is locally available. Based on the UE context being unavailable locally, the second base station may perform a UE context retrieval process by sending a UE context retrieval request message to the source base station of the UE. The UE context retrieval request message may include at least one of the following: a UE context ID; an integrity protection parameter; or a new cell identifier. The UE context ID may include at least one of the following: a C-RNTI containing the RRC re-establishment request message; and a PCI of the source PCell (the last serving PCell). The integrity protection parameter of the RRC re-establishment process may be a short MAC-I. The new cell identifier may be an identifier of a target cell, where the target cell is a cell for which re-establishment of the RRC connection has been requested. The new cell identifier is a cell identifier in a system information block (e.g., SIB1) of the target cell (e.g., the selected cell).

[0303] exist Figure 17 In the example, based on receiving the Retrieve UE Context Request message, the source base station may check the Retrieve UE Context Request message. If the source base station successfully identifies the UE context using the C-RNTI and successfully authenticates the UE using the short MAC-I, and decides to provide the UE context to the second base station, the source base station may respond to the second base station with a Retrieve UE Context Response message. The Retrieve UE Context Response message may include at least the GUAMI or UE context information. Based on receiving the Retrieve UE Context Response message, the second base station may send an RRC Reestablishment message to the UE. The RRC Reestablishment message may include a Network Hop Connection Count (NCC) value.

[0304] exist Figure 17 In the example of FIG, upon receiving the RRC reestablishment message, the UE may determine the current K value associated with the NCC value based on the current K value associated with the NCC value. gNB or next hop (NH) parameters to derive the new security key (K gNB ). New security key based on the base station (K gNB ) and the previously configured security algorithm, the UE can derive the security keys for integrity protection and encryption of RRC signaling (e.g., K RRCint and K RRCenc ) and the security keys for integrity protection and encryption of user plane (UP) data (e.g., K UPint and K UPenc ). Security key (K RRCint ), the UE can verify the integrity protection of the RRC reestablishment message. Based on the successful verification, the UE can be configured to use the integrity protection algorithm based on the previously configured K RRCintTo restore integrity protection for one or more bearers (e.g., signaling radio bearers or RRC messages), and is configured based on a previously configured encryption algorithm and K RRCenc to recover encryption for one or more bearers.

[0305] exist Figure 17 In the example, the second base station may send a first RRC reconfiguration message. The RRC first reconfiguration message may include SpCell configuration parameters. Based on receiving the SpCell configuration parameters, the UE may initiate transmission and reception of data to / from the second base station. The UE may send an RRC reconstruction completion message to the second base station. The RRC reconstruction completion message may include a measurement report. Based on receiving the measurement report, the second base station may determine to configure the SCell and / or secondary cell group (e.g., SCG or PSCell). Based on the determination, the second base station may send a second RRC reconfiguration message including SCell configuration parameters and / or MR-DC related configuration parameters. Based on receiving the second RRC reconfiguration message, the UE may transmit and receive data via the SCell and / or SCG.

[0306] exist Figure 17 In the example, the RRC reconfiguration message may include at least one of the cell group configuration parameters of the MCG and / or SCG, the radio bearer configuration parameters, or the AS security key parameters.

[0307] The base station may initiate an RRC connection release procedure to transition the UE's RRC state from an RRC connected state to an RRC idle state, from an RRC connected state to an RRC inactive state, from an RRC inactive state to an RRC inactive state when the UE attempts to resume, or from an RRC inactive state to an RRC idle state when the UE attempts to resume. The RRC connection procedure may also be used to release the UE's RRC connection and redirect the UE to another frequency. The base station may send an RRC release message including suspension configuration parameters to the UE. Based on the RRC release message, the UE may suspend the RRC connection. The UE may transition the UE's RRC state to an RRC inactive state or an RRC idle state. The suspension configuration parameters may include at least one of a recovery identity, an RNA configuration, a RAN paging cycle, or a network hop connection count (NCC) value, where the RNA configuration may include RNA notification area information or a periodic RNA update timer value (e.g., a T380 value). When the UE is in the RRC inactive state, the base station may use a recovery identifier (e.g., an inactive RNTI (I-RNTI)) to identify the UE context.

[0308] If the base station has a new and unused {NCC, next hop (NH)} pair, the base station may include the NCC in the pause configuration parameters. Otherwise, the base station may include the NCC in the pause configuration parameters that is consistent with the current K gNB The same NCC associated with the AS. The NCC is used for AS security. After sending the RRC release message including the suspension configuration parameters to the UE, the base station may delete the current AS key (e.g., K RRCenc , K UPenc ) and K UPint , but the current AS key K can be kept RRCint If the sent NCC value is new and belongs to an unused {NCC, NH} pair, the base station may save the {NCC, NH} pair in the current UE AS security context and may delete the current AS key K gNB If the NCC value sent is equal to the current K gNB The associated NCC value, the base station can maintain the current AS key K gNB The base station may store the sent recovery identifier together with the current UE context, which includes the remaining part of the AS security context.

[0309] After receiving the RRC release message including the suspension configuration parameters from the base station, the UE can verify that the integrity of the received RRC release message including the suspension configuration parameters is correct by checking the PDCP MAC-I. If the verification is successful, the UE can obtain the received NCC value and save it as the stored NCC with the current UE context. The UE can delete the current AS key K RRCenc , K UPenc and K UPint , but keep the current AS key K RRCint If the stored NCC value is different from the current K gNB The associated NCC value, the UE can delete the current AS key K gNB If the stored NCC is equal to the current K gNB If the NCC value associated with the AS key KgNB is not found, the UE shall keep the current AS key KgNB. The UE may store the received recovery identifier together with the current UE context including the rest of the AS security context for the next state transition.

[0310] Based on the receipt of the RRC release message including the suspension configuration parameters, the UE may reset the MAC, release the default MAC cell group configuration, and re-establish the RLC entity for one or more bearers. Based on the receipt of the RRC release message including the suspension configuration parameters, the UE may store the current configuration parameters and the current security keys in the UE inactive AS context. For example, the UE may store some current configuration parameters. The stored current configuration parameters may include the robust header compression (ROHC) state, the quality of service (QoS) flow to DRB mapping rules, the C-RNTI used in the source PCell, the global cell identity and physical cell identity of the source PCell, and all other parameters configured except the parameters within the synchronized reconfiguration and serving cell configuration common parameters in the SIB. The stored security keys may include K gNB and K RRCint At least one of the following. The serving cell configuration common parameters in the SIB can be used to configure the cell-specific parameters of the UE's serving cell in SIB1. Upon receiving the RRC release message including the suspension configuration parameters, the UE can suspend all SRBs and DRBs except SRB0. Upon receiving the RRC release message including the suspension configuration parameters, the UE can start timer T380, enter the RRC inactive state, and perform the cell selection process.

[0311] A UE in an RRC inactive state may initiate an RRC connection recovery procedure. For example, based on having data or signaling to transmit or receiving a RAN paging message, a UE in an RRC inactive state may initiate an RRC connection recovery procedure. Based on initiating the RRC connection recovery procedure, the UE may select an access category based on the triggering condition of the RRC connection recovery procedure, and perform a unified access control procedure based on the access category. Based on the unified access control procedure, the UE may regard the access attempt of the RRC connection recovery procedure as allowed. Based on regarding the access attempt as allowed, the UE may apply the default L1 parameter values ​​as specified in the corresponding physical layer specification, apply the default SRB1 configuration except for the parameters for which values ​​are provided in SIB1, apply the CCCH configuration, apply the common time alignment timer included in SIB1, apply the default MAC cell group configuration, start timer T319 and initiate transmission of an RRC recovery request message.

[0312] Based on initiating transmission of the RRC recovery request message, the UE may configure the content of the RRC recovery request message. The RRC recovery request message may include at least one of a recovery identifier, a recovery MAC-I, or a recovery reason. The recovery reason may include at least one of emergency, high priority access, MT access, MO signaling, MO data, MO voice call, MO SMS, RAN update, MPS priority access, and MCS priority access.

[0313] Based on the initiation of the transmission of the RRC recovery request message, in addition to the primary cell group configuration parameters, MR-DC related configuration parameters (e.g., secondary cell group configuration parameters) and PDCP configuration parameters, the UE can restore the stored configuration parameters and the stored security keys from the (stored) UE inactive AS context. The configuration parameters may include at least one of the following: the C-RNTI used in the source PCell, the global cell identity and physical cell identity of the source PCell, and all other parameters configured except the parameters within the synchronized reconfiguration and serving cell configuration common parameters in the SIB. Based on the current (recovered) K associated with the stored NCC value gNB or next hop (NH) parameter, the UE can derive the new key (K gNB Based on the new key of the base station, the UE can derive the security keys for integrity protection and encryption of RRC signaling (for example, K RRCenc and K RRCint ) and the security keys for integrity protection and encryption of user plane data (e.g., K UPint and K UPenc ). Configuration-based algorithms and K RRCint and K UPint , the UE can configure the lower layers (e.g., PDCP layer) to apply integrity protection to all radio bearers except SRB0. Based on the configured algorithm and K RRCenc and K UPenc , the UE may configure lower layers (eg, PDCP layer) to apply encryption to all radio bearers except SRB0.

[0314] Based on initiating the transmission of the RRC recovery request message, the UE can re-establish the PDCP entity for one or more bearers, recover one or more bearers and submit the RRC recovery request message to the lower layer, where the lower layer may include at least one of the PDCP layer, RLC layer, MAC layer or physical (PHY) layer.

[0315] The target base station may receive the RRC recovery request message. Based on receiving the RRC recovery request message, the target base station may check whether the UE context of the UE is locally available. Based on the UE context not being locally available, the target base station may perform a UE context retrieval procedure by sending a retrieve UE context request message to the source base station (the last serving base station) of the UE. The retrieve UE context request message may include at least one of a UE context ID, an integrity protection parameter, a new cell identifier, or a recovery cause, wherein the recovery cause is in the RRC recovery request message.

[0316] For the RRC connection recovery procedure, upon receiving the Retrieve UE Context Request message, the source base station may check the Retrieve UE Context Request message. If the source base station is able to identify the UE context using the UE Context ID and is able to successfully authenticate the UE using the integrity protection included in the Retrieve UE Context Request message, and decides to provide the UE context to the target base station, the source base station may respond to the target base station with a Retrieve UE Context Response message. If the source base station cannot identify the UE context using the UE Context ID, or if the integrity protection included in the Retrieve UE Context Request message is not valid, or if the source base station decides not to provide the UE context to the target base station, the source base station may respond to the target base station with a Retrieve UE Context Failure message.

[0317] For the RRC connection recovery process, the retrieval UE context failure message may include at least the XnAPID of the target base station, the RRC release message or the cause value.

[0318] For the RRC connection recovery process, upon receiving the retrieve UE context response message, the target base station may send an RRC recovery message to the UE. The RRC recovery message may include at least one of radio bearer configuration parameters, MCG and / or SCG cell group configuration parameters, measurement configuration parameters, or sk counters, wherein the sk counter is used to gNB The security key of the secondary base station is derived.

[0319] Upon receiving the UE context retrieval failure message, the target base station may send an RRC release message to the UE. For example, upon receiving the UE context retrieval failure message including an RRC release message, the target base station may send an RRC release message to the UE. Upon receiving the UE context retrieval failure message, the target base station may send an RRC setup message or an RRC reject message. Upon receiving the UE context retrieval failure message, the target base station may not send any response message to the UE.

[0320] Based on receiving the RRC resume message, the UE may stop timers T319 and T380. Based on receiving the RRC resume message, the UE may restore the primary cell group configuration parameters, secondary cell group configuration parameters, and PDCP configuration parameters in the UE inactive AS context. Based on restoring the primary cell group configuration parameters and / or secondary cell group configuration parameters, the UE may configure the SCells of the MCG and / or SCG by configuring lower layers to treat the restored MCG and / or SCG SCell as being in a deactivated state, discard the UE inactive AS context, and release the suspension configuration parameters.

[0321] Based on the cell group configuration parameters received in the RRC recovery message, the UE can perform MCG and / or SCG cell group configuration. Based on the radio bearer configuration parameters received in the RRC recovery message, the UE can perform radio bearer configuration. Based on the sk counter in the RRC recovery message, the UE can perform security key update for the secondary base station.

[0322] The UE can remain in CM-CONNECTED and move within the area configured by the base station without notifying the base station when the UE is in the RRC inactive state where the area is RNA. In the RRC inactive state, the last serving base station can maintain the UE context and the NG connection associated with the UE serving the AMF and UPF. Based on the downlink data received from the UPF when the UE is in the RRC inactive state or the downlink UE-associated signaling received from the AMF, the last serving base station can perform paging in the cell corresponding to the RNA, and can send RAN paging to the neighboring base station via the Xn interface if the RNA includes the cell of the neighboring base station.

[0323] The AMF may provide core network assistance information to the base station to assist the base station in deciding whether the UE can be sent to the RRC inactive state. The core network assistance information may include the registration area configured for the UE, the periodic registration update timer, the UE identity index value, the UE-specific DRX, an indication of whether the UE is configured with mobile initiated connection only (MICO) mode through the AMF; or the expected UE behavior. The base station may use the UE-specific DRX and UE identity index value to determine the paging occasion for RAN paging. The base station may use the periodic registration update timer to configure the periodic RNA update timer (e.g., timer T380). The base station may use the expected UE behavior to assist the UE RRC state transition decision.

[0324] Figure 18 An example of an RRC connection recovery process is shown. A UE in an RRC connected state can transmit and receive data to / from a first base station (source base station) via cell 1. The first base station can determine to transition the UE in an RRC connected state to an RRC inactive state. Based on this determination, the base station can send an RRC release message including a suspension configuration parameter.

[0325] exist Figure 18In an example, based on receiving an RRC release message including suspended configuration parameters, the UE may store current security keys (e.g., KgNB and KRRCint keys) and current configuration parameters in the UE inactive AS context. For example, the UE may store some current configuration parameters. The stored (current) configuration parameters may be at least one of: robust header compression (ROHC) state; QoS flow to DRB mapping rules; C-RNTI used in the source PCell; global cell identity and physical cell identity of the source PCell; and all other parameters configured except for the parameters within the synchronized reconfiguration and serving cell configuration common parameters in the SIB. The robust header compression (ROHC) state may include the ROHC state of all PDCP entities (or all bearers), where each PDCP entity (or each bearer) for each bearer may have one ROHC state. The QoS flow to DRB mapping rule may be a QoS flow to DRB mapping rule for all data radio bearers (DRBs), where each DRB may have one QoS flow to DRB mapping rule.

[0326] exist Figure 18 In the example, based on receiving the RRC release message including the suspension configuration parameters, the UE may suspend all SRBs and DRBs except SRB0. Based on receiving the RRC release message including the suspension configuration parameters, the UE may start timer T380, enter the RRC inactive state, and perform a cell selection process. Based on the cell selection process, the UE may select cell 2 of the second base station (target base station). The UE in the RRC inactive state may initiate an RRC connection recovery process. The UE may perform a unified access control process. Based on the unified access control process, the UE may regard the access attempt of the RRC connection recovery process as allowed. The UE may apply the default L1 parameter values ​​as specified in the corresponding physical layer specification, apply the default SRB1 configuration except for the parameters for which values ​​are provided in SIB1, apply the CCCH configuration, apply the common time alignment timer included in SIB1, apply the default MAC cell group configuration, start timer T319 and initiate transmission of the RRC recovery request message.

[0327] exist Figure 18 In the example of the RRC resume request message, the UE can recover the stored configuration parameters and the stored security keys from the (stored) UE inactive AS context. For example, in addition to the primary cell group configuration parameters, MR-DC related configuration parameters (e.g., secondary cell group configuration parameters) and PDCP configuration parameters, the UE can recover the stored configuration parameters and the stored security keys (e.g., K gNB and K RRCint). Based on the current (recovered) K associated with the stored NCC value gNB or next hop (NH) parameter, the UE can derive the new key (K gNB Based on the new key of the base station, the UE can derive the security keys for integrity protection and encryption of RRC signaling (for example, K RRCenc and K RRCint ) and the security keys for integrity protection and encryption of user plane data (e.g., K UPint and K UPenc ). Configuration-based algorithms and K RRCint and K UPint , the UE (RRC layer) can configure the lower layers (e.g., PDCP layer) to apply integrity protection to all radio bearers except SRB0. Based on the configured algorithm and K RRCenc and K UPenc , the UE may configure lower layers (e.g., the PDCP layer) to apply encryption to all radio bearers except SRB0. Integrity protection and / or encryption may be required for communications between the UE and the base station. Based on the integrity protection and / or encryption, the UE may be able to transmit and receive data to / from the second base station. The UE may transmit and receive data to / from the second base station using the recovered configuration parameters.

[0328] exist Figure 18 In the example, based on initiating the transmission of the RRC recovery request message, the UE can re-establish the PDCP entity for one or more bearers, recover the one or more bearers, and submit the RRC recovery request message to the lower layer. Based on receiving the RRC recovery request message, the second base station can check whether the UE context of the UE is locally available. Based on the UE context being unavailable locally, the second base station can perform a UE context retrieval process by sending a UE context retrieval request message to the first base station (the last serving base station) of the UE. The UE context retrieval request message may include at least one of the following: a recovery identifier; a recovery MAC-I; or a recovery reason.

[0329] exist Figure 18In the example, based on receiving the retrieve UE context request message, the first base station may check the retrieve UE context request message. If the first base station is able to identify the UE context by means of the UE context ID, and is able to successfully verify the UE by means of the restore MAC-I, and decides to provide the UE context to the second base station, the first base station may respond to the second base station with a retrieve UE context response message. Based on receiving the retrieve UE context response message, the second base station may send an RRC resume message to the UE. Based on receiving the RRC resume message, the UE may restore the primary cell group configuration parameters, secondary cell group configuration parameters and PDCP configuration parameters in the UE inactive AS context. Based on restoring the primary cell group configuration parameters and / or secondary cell group configuration parameters, the UE may configure the SCell of the MCG and / or SCG by configuring the lower layer to regard the restored MCG and / or SCG SCell as being in an inactive state, discard the UE inactive AS context, and release the suspension configuration parameters. The UE may transmit and receive data via the SCell and / or SCG.

[0330] The base station may send an RRC release message to the UE to release the UE's RRC connection. Based on the RRC release message, the UE may release the established radio bearer and all radio resources.

[0331] The base station may send an RRC release message to the UE to suspend the RRC connection. Based on the RRC release message, the UE may suspend all radio bearers except Signaling Radio Bearer 0 (SRB0). The RRC release message may include suspension configuration parameters. The suspension configuration parameters may include a next hop link count (NCC) and a resume identifier (e.g., an ID or identifier).

[0332] The base station may send an RRC release message to transition a UE in an RRC connected state to an RRC idle state; or transition a UE in an RRC connected state to an RRC inactive state; or transition a UE in an RRC inactive state back to an RRC inactive state when the UE attempts to resume; or transition a UE in an RRC inactive state to an RRC idle state when the UE attempts to resume.

[0333] The base station may send an RRC release message to redirect the UE to another frequency.

[0334] The UE may receive an RRC release message from the base station of the serving cell (or PCell). Based on the RRC release message, the UE may perform a UE action for the RRC release message from the base station. The UE may delay the UE action for the RRC release message for a period of time (e.g., 60 ms) from the moment the RRC release message is received or when the RRC release message is successfully acknowledged. The UE may send a HARQ acknowledgement to the base station to acknowledge the RRC release message. Based on the RLC protocol data unit (PDU) including the RRC release message and the RLC PDU including the polling bit, the UE may send an RLC message (e.g., a status report) to the base station to acknowledge the RRC release message.

[0335] The UE action for the RRC release message from the base station may include at least one of: suspending the RRC connection; releasing the RRC connection; a cell (re)selection procedure; and / or idle / inactive measurements.

[0336] The RRC release message from the base station may include a suspension configuration parameter. Based on the suspension configuration parameter, the UE may suspend the RRC connection. Suspending the RRC connection may include at least one of: a media access control (MAC) reset (or reset MAC); releasing a default MAC cell group configuration; reestablishing an RLC entity for one or more radio bearers; storing current configuration parameters and current security keys; suspending one or more bearers, including signaling radio bearers and data radio bearers; and / or transitioning to an RRC idle state or an RRC inactive state.

[0337] For example, the suspend configuration parameters may also include RNA configuration parameters. Based on the RNA configuration parameters, the UE may transition to the RRC inactive state. For example, based on the suspend configuration parameters not including the RNA configuration parameters, the UE may transition to the RRC idle state. For example, the RRC release message including the suspend configuration parameters may include an indication of transitioning to the RRC inactive state. Based on the indication, the UE may transition to the RRC inactive state. For example, based on the RRC release message not including the indication, the UE may transition to the RRC idle state.

[0338] Based on the MAC reset, the UE may perform at least one of the following: stop all timers running in the UE-MAC layer; consider all time alignment timers expired; set the new data indicator (NDI) of all uplink HARQ processes to a value of 0; stop the ongoing RACH process; discard the explicitly signaled contention-free random access resources (if any); flush the Msg 3 buffer; cancel the triggered scheduling request process; cancel the triggered buffer status report process; cancel the triggered power headroom report process; flush the soft buffers of all DL HARQ processes; for each DL HARQ process, treat the next received transmission of the TB as the first transmission; and / or release the temporary C-RNTI.

[0339] Based on considering the time alignment timer to be expired, the UE may perform at least one of the following: flush all HARQ buffers for all serving cells; notify RRC to release PUCCH for all serving cells, if configured; notify RRC to release SRS for all serving cells, if configured; clear any configured downlink assignments and configured uplink grants; clear any PUSCH resources used for semi-persistent CSI reporting; and / or consider all running time alignment timers to be expired.

[0340] The default MAC cell group configuration parameters may include buffer status report (BSR) configuration parameters of the cell group of the base station (e.g., BSR timer) and power headroom report (PHR) configuration parameters of the cell group of the base station (e.g., PHR timer or PHR transmission power factor change parameter).

[0341] Reestablishing the RLC entity may include at least one of: discarding all RLC SDUs, RLC SDU segments, and RLC PDUs, if any; stopping and resetting timers of all RLC entities; and resetting all state variables of the RLC entity to their initial values.

[0342] The RRC release message from the base station may not include the suspend configuration parameter. Based on the RRC message not including the suspend configuration parameter, the UE may perform a release of the RRC connection. Releasing the RRC connection may include at least one of: a MAC reset (or resetting the MAC); discarding stored configuration parameters and stored security keys (or discarding stored UE inactive AS contexts); releasing the suspension configuration parameters; releasing all radio resources, including releasing the RLC entity, MAC configuration, and associated PDCP entity and SDAP for all established radio bearers; and / or transitioning to an RRC idle state.

[0343] The RRC release message may include an RRC early data complete message.

[0344] Small Data Transfer (SDT) is a procedure that allows data transmission / reception while the wireless device remains in the RRC Inactive State or the RRC Idle State (eg, without transitioning to the RRC Connected State).

[0345] In an example, a small data transfer (SDT) procedure may include exchanging user data between a wireless device and a base station when the wireless device is in a non-connected state (e.g., a radio resource control (RRC) non-connected state) (e.g., an idle state, an inactive state, etc.). The amount of data exchanged in an SDT transmission of the SDT procedure may be less than a threshold amount of data. The SDT procedure may include a single SDT transmission and / or a sequence of SDT transmissions of a small amount of data. For example, using the SDT procedure, the wireless device and / or the base station may transmit and / or receive data via a user plane (UP) or a control plane (CP) while the wireless device remains in a non-connected state (e.g., idle, inactive, etc.). For example, using the SDT procedure, the wireless device may transmit and / or receive data without completing a connection setup or recovery procedure (and without control plane signaling associated with the setup and / or recovery). The data may include user data and signals.

[0346] In an example, a wireless device may require an authorization to transmit data associated with an SDT process (e.g., uplink data). The wireless device may receive an authorization from / via a base station. The authorization may be an uplink authorization for one or more uplink resources, and the wireless device may use the one or more uplink resources to transmit data (e.g., uplink data). The authorization may be a dynamic uplink authorization or a configured uplink authorization for one or more uplink resources. A dynamic uplink authorization may indicate one or more specific uplink resources to be used for uplink transmission at a specific time. A configured uplink authorization may indicate recurring, intermittent, and / or periodic resources. For example, a configured uplink authorization configuration may indicate the periodicity of a configured uplink authorization, and one or more uplink resources configured by the configured uplink authorization may be used and reused at periodic intervals. For example, a configured uplink authorization may be configured / activated, and resources associated with the configured uplink authorization configuration of the configured uplink authorization may be used until the configured uplink authorization is released / deactivated. As an illustration, a dynamic uplink grant may indicate resources at time k, while a configured uplink grant may grant resources at time k+nT, where T is the period of the configured uplink grant and n is an integer [0, 1, 2, ...].

[0347] In an example, the wireless device may obtain an uplink grant via a physical or MAC signal (e.g., DCI or random access (RA) response) indicating an uplink grant. For example, in a random access (RA)-based procedure (e.g., an early data transfer (EDT) procedure), the wireless device may send an RA preamble requesting one or more uplink resources. Based on the RA preamble, the wireless device may receive an uplink grant indicating one or more uplink resources for transmitting small data.

[0348] In an example, the wireless device may obtain an uplink grant based on a configured uplink grant (CG). The configured uplink grant may be associated with a configured uplink grant configuration (e.g., a preconfigured uplink resource (PUR) configuration). The wireless device may receive the configured uplink grant configuration via an RRC message (e.g., an RRC release message). The configured uplink grant configuration may indicate a grant of one or more uplink resources, and the wireless device may use and / or reuse one or more uplink resources (e.g., preconfigured uplink resources) to transmit small data.

[0349] SDT may be configured to be performed on RACH or configured uplink grant (CG) resources (e.g., type 1 CG resources). SDT configured to be performed on RACH may be referred to as RACH-based SDT (or EDT). SDT configured to be performed on CG resources may be referred to as CG-based SDT (or uplink transmission using PUR). For example, the wireless device may transmit a first uplink message for the SDT procedure based on an uplink grant from a RACH-based SDT or a CG-based SDT. For example, the wireless device may transmit a first uplink message for the SDT procedure based on an RA response indicating an uplink grant for the SDT procedure or a configured uplink grant for the SDT procedure. For example, for subsequent transmissions, the wireless device may transmit data / signals using a dynamic uplink grant or a configured uplink grant. The base station may transmit the dynamic uplink grant or the configured uplink grant to the wireless device.

[0350] The configured uplink grant for SDT (e.g., SDT resources) can be configured on the initial BWP or a dedicated BWP. The configured uplink grant for SDT can be configured on the normal uplink (NUL) carrier and / or the supplementary uplink (SUL) carrier. The configured uplink grant for SDT can be provided to the wireless device in the RRC connected state via / within the RRC release message. For RACH, the base station can configure to the wireless device whether the 2-step and 4-step RA types are available for SDT. When both are available, the UE can select one of the RA types.

[0351] The wireless device may select RACH resources for SDT. The RACH resources may be different from the RACH resources used for the RRC connection. The RACH resources may include at least one of the following: an RA preamble and a RACH opportunity (RO). The wireless device may use the RACH resources to perform a RACH procedure for SDT. The wireless device may receive a random access response (RAR) via a serving cell of a base station. The RAR may include / indicate an uplink grant for SDT. Based on the RAR, the wireless device in an RRC inactive state or an RRC idle state may transmit a first (uplink) message for SDT to the base station.

[0352] SDT may include user plane (UP) small data transmission and control plane (CP) small data transmission. Based on UP small data transmission, a UE in an RRC idle state or RRC inactive may transmit / receive data via the user plane (e.g., via DTCH). Based on CP small data transmission, a UE in an RRC idle state or RRC inactive may transmit / receive data via the control plane (e.g., CCCH). Based on UP small data transmission, the base station of the UE may receive downlink data from the UPF of the UE via the user plane. Based on CP small data transmission, the base station of the UE may receive downlink data from the AMF of the UE via the control plane. / Non-SDT

[0353] The base station may configure / indicate a first radio bearer to the wireless device. The first radio bearer may be configured for SDT. For example, the base station may transmit an RRC release message to the wireless device to configure / indicate the first radio bearer. The base station may transmit a configuration of an SDT process (SDT configuration) to the wireless device. The SDT configuration may include parameters of the first radio bearer. The RRC release message may include the SDT configuration. The wireless device may transmit SDT data for the first radio bearer during the SDT process.

[0354] The SDT data may be data of the first logical channel of the first radio bearer. The data may include user data and signals. The first radio bearer may include a data radio bearer (DRB) and a signaling radio bearer (SRB). The SRBs may include SRB1 and SRB2. The base station may allow the wireless device to transmit SDT data during the SDT process.

[0355] The user data may be user data of a DRB. The signal may be a signal of an SRB. The wireless device may transmit the user data via the DRB. The wireless device may transmit the signal via the SRB. For example, the signal may be an RRC message or a NAS message.

[0356] The second radio bearer may not be configured for the SDT process. The second radio bearer may not be the first radio bearer. The base station may not allow the wireless device to transmit data of the second radio bearer during the SDT process. Non-SDT data may be data of the second logical channel of the second radio bearer. The data may include user data and signals. The second radio bearer may include a data radio bearer (DRB) and a signaling radio bearer (SRB). The SRB may include SRB1 and SRB2. The user data may be user data of the DRB. The base station may not allow the wireless device to transmit non-SDT data during the SDT process.

[0357] The wireless device may determine to initiate an SDT procedure. For example, the wireless device may determine to initiate an SDT procedure based on at least one of: less than a configured amount of uplink (UL) data awaiting transmission across an SDT-enabled radio bearer; and a signal strength (e.g., RSRP) measured in a cell being above a configured threshold.

[0358] Based on initiating the SDT procedure, the wireless device may (re)activate AS security. For example, the wireless device may have a stored value of the Next Hop Link Count (NCC) provided in the RRC Release message during the previous RRC Connection Release procedure. For example, the RRC Release message may include suspended configuration parameters. Based on initiating the SDT procedure, the wireless device may derive base station-specific keys (e.g., KgNB / KeNB) using the NCC. Based on the base station-specific keys, the wireless device may derive keys for integrity protection and keys for ciphering. The keys for integrity protection may include a key KRRCint for integrity protection of RRC messages and a key KUPint for integrity protection of the user plane (data). The keys for ciphering may include a key KRRCenc for ciphering of RRC messages and a key KUPenc for ciphering of the user plane (data). The wireless device may be configured to use the keys for integrity protection to restore integrity protection for data / signals received and sent by the wireless device during the SDT procedure. The wireless device may be configured to use the keys for ciphering to restore ciphering for data / signals received and sent by the wireless device during the SDT procedure.

[0359] Once initiated, the SDT process may continue as long as the wireless device is not explicitly directed to RRC idle or RRC inactive (via RRC release) or RRC connected (via RRC resume).

[0360] The SDT process may include at least one of an initial SDT transmission and subsequent transmissions. Upon initiating the SDT process, the wireless device may transmit a first (uplink) message for the SDT process. The wireless device may transmit the first message via SDT resources. The SDT resources may be CG resources or an uplink grant in response to a RACH preamble for the SDT process.

[0361] The first message may be Msg 3 or Msg A. The first message may include at least one of the following: an RRC request message; first uplink data; auxiliary parameters for an SDT process (or auxiliary information for an SDT process); and a request for an uplink grant for second uplink data. The RRC request message may be transmitted via a common control channel (CCCH). The CCCH message may include the RRC request message. The first uplink data may include user data and a signal (e.g., an RRC message). The user data of the first uplink data may be transmitted via a dedicated traffic channel (DTCH). The signal of the first uplink data may be transmitted via a dedicated control channel (DCCH). The DTCH message may include the user data of the first uplink data. The DCCH message may include the signal of the first uplink data. The CCCH message and the DTCH / DCCH message may be multiplexed into the first message. The first message may include at least one of the following: a CCCH message, a DTCH message, and a DCCH message. The auxiliary parameters (or auxiliary information) may include (expected) service information for the wireless device. The traffic information may indicate at least one of: whether subsequent transmission of uplink and / or downlink data is expected; and the amount of data for the subsequent transmission. For example, the auxiliary parameter may include release assistance information (RAI). The request for an uplink grant for the second uplink data may be a buffer status report (BSR).

[0362] The wireless device may receive a response to the first message from the base station. The response may include an RRC response message to the RRC request message of the first uplink message. Based on the response including the RRC response message, the wireless device may complete the SDT procedure. The RRC response message may be an RRC release message, an RRC resume message, or an RRC setup message. Based on the RRC response message being the RRC release message, the wireless device may transition back to the RRC idle state or the RRC inactive state. Based on the RRC message being the RRC resume / setup message, the wireless device may transition to the RRC connected state.

[0363] The wireless device may receive a response to the first message from the base station. The response may not include an RRC response message. The base station may determine that the wireless device is permitted to perform a subsequent transmission in an RRC inactive or RRC idle state. The response may indicate an uplink grant for the subsequent transmission. The response may indicate the subsequent transmission. Based on the response, the wireless device may perform the subsequent transmission while remaining in the RRC inactive or RRC idle state. For example, the response may be Msg 4 or Msg B.

[0364] After the initial SDT transmission, subsequent transmissions can be handled differently depending on the configured resource type: when CG resources are used, the network can use dynamic grants to schedule subsequent UL transmissions, or they can be performed at the next CG resource opportunity; when RACH resources are used, the network can use dynamic grants and allocations to schedule subsequent UL and downlink DL transmissions after completing the RA process.

[0365] During a subsequent transmission, the wireless device may receive an RRC response message in response to the RRC request message of the first uplink message. Based on the RRC response message, the wireless device may complete the SDT procedure. The RRC response message may be an RRC release message, an RRC resume message, or an RRC setup message. Based on the RRC response message being an RRC release message, the wireless device may transition back to the RRC idle state or the RRC inactive state. Based on the RRC response message being an RRC resume / setup message, the wireless device may transition to the RRC connected state.

[0366] Based on receiving the paging message indicating SDT (procedure), the wireless device may determine to initiate the SDT procedure. The wireless device may transmit a first uplink message for the SDT procedure, wherein the first uplink message may include an RRC request message. The RRC request message may indicate the SDT (procedure).

[0367] Based on satisfying the configured uplink grant conditions, the UE may determine to use the configured uplink grant to perform initiated SDT (CG-based SDT). The configured uplink grant conditions may include at least one of the following: the UE has valid configured uplink grant configuration parameters; the UE has a valid timing alignment (TA) value; the system information of the serving cell indicates that the configured uplink grant is supported; the establishment or resumption request is for a mobile originated call and the establishment reason is mo data or mo exception data or delay tolerant access; the UE supports the configured uplink grant; the size of the result MAC PDU including the total uplink data is expected to be less than or equal to the TBS configured for the configured uplink grant and the UE has a stored NCC value provided in the RRC release message, which includes the suspension configuration parameters during the previous suspension process.

[0368] The UE may determine that the timing alignment value for the small data transmission of the configured uplink grant is valid based on satisfying a TA verification condition for the configured uplink grant. The TA verification condition for the configured uplink grant may include at least one of the following: a time alignment timer for the configured uplink grant is running; or a serving cell RSRP has not increased by more than an RSRP increase threshold and has not decreased by more than an RSRP increase threshold.

[0369] For CG-based SDT (or uplink transmission using PUR), a UE in an RRC connected state may transmit a CG (or PUR) configuration request message (or auxiliary information message) to the base station, wherein the CG configuration request message may include at least one of: a requested number of CG opportunities, where the number may be one or infinity; a requested CG periodicity; a requested transport block size (TBS) for the CG; and / or a requested time offset for the first CG opportunity.

[0370] The base station may transmit a configured uplink grant configuration (parameters) including a (pre-)configured uplink grant (resource) to the wireless device. For example, in response to a configured uplink grant configuration request message, the base station may transmit the configured uplink grant configuration parameters including the pre-configured uplink resources to the UE. For example, the base station may send an RRC release message including the configured uplink grant configuration parameters.

[0371] The configured uplink grant configuration parameters may include at least one of the following: an indication of setting or releasing the configured uplink grant configuration parameters; the number of configured uplink grant opportunities; a configured uplink grant resource identifier (configured uplink grant RNTI); a configured uplink grant configuration identifier (configured uplink grant configID); a time offset value of the first configured uplink grant opportunity (configured uplink grant start time); a periodicity of the configured uplink grant resource (configured uplink grant periodicity); a duration of the configured uplink grant response window (configured uplink grant response window time); a threshold value for the change in RSRP of the serving cell in dB for TA verification (configured uplink grant change threshold), wherein the threshold value includes an RSRP increase threshold and an RSRP decrease threshold; a value of a time calibration timer for the configured uplink grant; and / or physical configuration parameters for the configured uplink grant. The physical configuration parameters for the configured uplink grant may include at least one of: a PUSCH configuration parameter for the configured uplink grant; a PDCCH configuration parameter for the configured uplink grant; a PUCCH configuration parameter for the configured uplink grant; a downlink carrier configuration parameter for the configured uplink grant; and / or an uplink carrier frequency for the uplink carrier of the configured uplink grant. The configured uplink grant RNTI may be assigned to more than one wireless device. The configured uplink grant configID may be unique within a base station.

[0372] Based on the configured uplink grant configuration parameters, the UE may store or replace the configured uplink grant configuration parameters provided by the configured uplink grant configuration parameters based on an indication requesting to set the configured uplink grant configuration parameters. In response to receiving the configured uplink grant configuration parameters, the UE may start a time alignment timer for the configured uplink grant with the value of the time alignment timer for the configured uplink grant and configure the configured uplink grant configuration parameters. For example, based on an indication requesting to set the configured uplink grant configuration parameters, the UE may start a time alignment timer for the configured uplink grant with the value of the time alignment timer for the configured uplink grant and configure the configured uplink grant configuration parameters. In response to receiving the configured uplink grant configuration parameters, the UE may discard the configured uplink grant configuration parameters based on an indication requesting to release the configured uplink grant configuration parameters. In response to configuring the configured uplink grant configuration parameters, the UE may generate a configured uplink grant based on the configured uplink grant configuration parameters. For example, based on configured uplink grant configuration parameters, the UE may determine when to generate a configured uplink grant. For example, based on a configured uplink grant start time and a configured uplink grant period, the UE may determine when to generate a configured uplink grant. For example, based on PUSCH configuration parameters, the UE may determine (the transport block of) a configured uplink grant. For example, based on PUSCH configuration parameters, the UE may determine (the transport block of) a configured uplink grant.

[0373] Based on the CG configuration parameters, the UE in the RRC idle state or the RRC inactive state can use the value of the time alignment timer for the CG to start the time alignment timer for the CG and configure the CG configuration parameters. In response to configuring the CG configuration parameters, the UE in the RRC idle state or the RRC inactive state can generate pre-configured uplink resources / grants for the CG based on the CG configuration parameters. Based on the first RRC release message, the UE can perform a cell (re)selection process. Based on the cell (re)selection process, the UE in the RRC idle state or the RRC inactive state can select cell 2 of the second base station (target base station). The UE in the RRC idle state or the RRC inactive state can have first uplink data in the uplink buffer. The UE in the RRC idle state or the RRC inactive state can determine to initiate a CG-based SDT based on satisfying one or more conditions.

[0374] The wireless device may use the CG (or uplink resources / grants for the CG) to transmit a message (e.g., the first uplink message for the SDT process), and the UE (UE-MAC entity) may use the CG response window time to start the CG response window timer. Based on the start, the UE may monitor the PDCCH identified by the CG RNTI until the CG response window timer expires. The UE (UE-MAC entity) may receive a downlink message (e.g., DCI) identified by the CG RNTI on the PDCCH. Based on the receipt of a downlink message indicating an uplink grant for retransmission, the UE may restart the CG response window timer at the last subframe, pulse time gap (e.g., 4 subframes) of the PUSCH transmission indicating the uplink grant. Based on the restart, a UE in an RRC idle state or an RRC inactive state may monitor the PDCCH identified by the CG RNTI until the CG response window timer expires. Based on the receipt of a downlink message indicating an L1 (layer 1) confirmation for the CG, the UE in an RRC idle state or an RRC inactive state may stop the CG response window timer and deem the CG-based SDT successful. Based on receiving a downlink message indicating a fallback for PUR, a UE in an RRC idle state or an RRC inactive state may stop the CG response window timer and consider that the CG-based SDT has failed. Based on receiving a downlink message indicating a PDCCH transmission (downlink grant or downlink assignment) addressed to a CG RNTI and / or MAC PDU including successfully decoded uplink data, a UE in an RRC idle state or an RRC inactive state may stop the CG response window timer and consider that the CG-based SDT has succeeded. Based on the PDCCH transmission, the UE in an RRC idle state or an RRC inactive state may receive at least one of an RRC response message and downlink data. The RRC response message may include at least one of an RRC release message or an RRC early data complete message. Based on not receiving any downlink message until the CG response window timer expires, the UE in an RRC idle state or an RRC inactive state may consider that the CG-based SDT has failed. Based on considering that the CG-based SDT has failed, the UE may perform a random access procedure. For example, the random access procedure may include a RACH procedure for RACH-based SDT.

[0375] The CG resources for the SDT process may be configured on the NUL and / or SUL. The wireless device may initiate (respond to) the window after the CG transmission or the dynamic grant (DG) transmission for CG-based SDT. The wireless device may start a timer for the window based on the activation window.

[0376] The wireless device may start a timer alignment timer (TAT) associated with a CG-SDT resource (TAT-SDT) upon receiving a TAT-SDT configuration from a base station (e.g., via an RRC release message). The wireless device may restart the TAT-SDT upon receiving a TA command. The wireless device may determine that the CG resource for the SDT process is valid based on a TA verification mechanism. For example, the wireless device may determine that the CG resource for the SDT process is valid based on the RSRP associated with the CG resource and an RSRP threshold associated with the CG resource.

[0377] For CG-based SDT, the subsequent data transmission can use CG resources or DG (e.g., a dynamic grant addressed to the UE's C-RNTI). The C-RNTI can be a C-RNTI previously assigned or explicitly configured by the base station. The base station can transmit multiple CG-SDT configurations per carrier in the RRC idle state or the RRC inactive state. The CG-SDT resources can be valid in one cell. When the TAT-SDT expires in the RRC idle state or the RRC inactive state, the wireless device can release the CG-SDT resources.

[0378] The base station may transmit the configuration of the SDT process to the wireless device via an RRC release message. The configuration may indicate the radio bearers (e.g., SDT bearers) configured for the SDT process. Based on receiving the RRC release message, the wireless device may suspend one or more radio bearers. The wireless device may suspend the RRC connection. The wireless device may resume the SDT bearers based on initiating the SDT process while keeping non-SDT bearers suspended. During the SDT process, the wireless device may transmit / receive data / signals associated with the SDT bearers.

[0379] During the SDT process, the wireless device may receive an RRC message (eg, an RRC resume message) to transition to the RRC connected state. Based on receiving the RRC resume message, the wireless device may resume the non-SDT bearers. The wireless device may transition to the RRC connected state.

[0380] During the SDT process, the wireless device may transmit a message based on having data / signals associated with a non-SDT bearer. The message may indicate the arrival of data / signals associated with the non-SDT bearer. The message may request a transition to the RRC connected state. The message may be a common control channel (CCCH) message; or a dedicated control channel (DCCH) message. For example, the CCCH message may include an RRC (resume) request message. The DCCH message may include an auxiliary information message. Based on receiving the message, the base station may transmit an RRC message (e.g., an RRC resume message) to transition to the RRC connected state.

[0381] A wireless device performing an SDT procedure may detect a failure of the SDT procedure. The failure may include at least one of: expiration of an SDT failure detection timer; cell (re)selection / change; inability to comply with an RRC message; radio link failure (RLF); RLC (PDU) maximum retransmission failure; receiving a rejection / backoff indication from a base station; or expiration of a CG response window timer.

[0382] The wireless device may start the SDT failure detection timer based on initiating the SDT procedure. The wireless device may not start T319 or T300, where T319 or T300 is configured to be started based on the RRC recovery request message.

[0383] Upon detecting a failure of the SDT procedure, the wireless device may release the RRC connection. For example, the wireless device may transition to an RRC idle state by releasing the RRC connection. The wireless device may perform a higher layer (eg, application layer) retransmission.

[0384] Based on detecting a failure of the SDT procedure, the wireless device may maintain the RRC connection suspended. For example, the wireless device may remain in an RRC inactive state. The wireless device may remain in an RRC idle state while the RRC connection is suspended. The wireless device may transmit an RRC resume request to the new cell. For example, the wireless device may select a new cell based on a cell (re)selection procedure in response to detecting the failure.

[0385] Figure 19 An example of a Small Data Transfer (SDT) is shown. The wireless device may be in a non-connected state (e.g., an RRC idle state, an RRC inactive state, etc.). For example, the wireless device may receive a release message. The release message may be an RRC release message. The wireless device may transition to a non-connected state based on the release message. The wireless device may determine to initiate an SDT (procedure). The determination may be made while the wireless device is in the non-connected state. The determination may be based on the wireless device being in the non-connected state.

[0386] exist Figure 19 In an example, the wireless device may determine to initiate an SDT procedure (e.g., based on satisfying one or more SDT conditions). The determination may be made when the UE is in a non-connected state. The determination may be based on the UE being in a non-connected state. Initiating SDT may include at least one of: activating / deriving security keys for integrity protection and / or ciphering; configuring to restore integrity protection; applying security keys for ciphering to data / signals; configuring to use SDT; and generating an RRC request message.

[0387] exist Figure 19In the example of , based on initiating SDT, the wireless device may transmit a first (uplink) message (for the initial SDT). The first message may be transmitted when in a non-connected state. The first message may be transmitted to the base station (via the serving cell of the base station). The first message may be Msg 3 and / or Msg A. The first message may include at least one of the following: an RRC request message for SDT; first uplink data; and auxiliary parameters for SDT (or auxiliary information for the SDT process). The first message may indicate that a subsequent transmission (and reception) is expected / required. For example, the auxiliary parameters may indicate the (expected) traffic type / size for the subsequent transmission. Msg 3 and / or Msg A may be transmitted on an uplink shared channel (UL-SCH). As part of the random access procedure, Msg 3 and / or Msg A may contain a C-RNTI MAC CE and / or a CCCH SDU and be associated with a UE contention resolution identifier. The wireless device may perform a RACH procedure for SDT. For example, the wireless device may perform a RACH procedure using RACH resources configured for SDT.The RACH resources may include at least one of: a RA preamble for SDT and a RACH opportunity (RO).

[0388] exist Figure 19 In an example, the SDT (process) may include an initial small data transmission (or an initial small data transmission phase) and a subsequent transmission (or a subsequent transmission phase or a subsequent SDT (phase)). For example, the wireless device may initiate the SDT process. The wireless device may determine to initiate the SDT process based on receiving a paging message indicating an SDT; or having a packet associated with the SDT. For example, the packet may be a packet of a radio bearer configured for the SDT. The wireless device may initiate the SDT based on satisfying an SDT condition, wherein the SDT condition includes at least one of the following: a first condition for an RA-based SDT; or a second condition for a CG-based SDT. Based on initiating the SDT, the wireless device may transmit a first (uplink) message for the initial SDT. The initial SDT may include transmitting the first message and receiving a response to the first message. The initial SDT phase may be a duration from the transmission time of the first message to the time of determining whether the transmission is successfully completed. The time may be the reception time of the response to the first message. The wireless device may initiate the subsequent SDT (phase) after successfully completing the initial (SDT) transmission. The wireless device may complete the (latter) SDT process based on receiving a message indicating that the SDT process is completed; or detecting that the SDT process has failed. The message may be an RRC release message.

[0389] exist Figure 19In an example, based on satisfying the second condition, the wireless device may transmit the first message using the CG configured for the SDT. The wireless device may start a CG (or PUR) response window timer and monitor the PDCCH of the cell for a response to the first message. Based on receiving a response, the wireless device may determine that the initial SDT (or transmission of the first message) was successfully completed. Based on not receiving a response (e.g., before the CG response window timer expires), the wireless device may determine that the initial SDT (or transmission of the first message) was not successfully completed.

[0390] exist Figure 19 In an example, based on satisfying a first condition, the wireless device may transmit an RA preamble using RA resources for an (initial) SDT. Based on receiving an RA response indicating uplink resources for the (initial) SDT, the wireless device may transmit a first message using the uplink resources. Based on receiving a response to the first message, the wireless device may determine that the initial SDT (or the transmission of the first message) was successfully completed. Based on not receiving a response, the wireless device may determine that the initial SDT (or the transmission of the first message) was not successfully completed.

[0391] exist Figure 19 In the example, based on the first message, the base station may determine whether to allow / configure subsequent transmission / reception using SDT (subsequent SDT). The base station may transmit a second message via the serving cell to indicate the result of the determination of whether to perform the subsequent SDT. The second message may be Msg 4 and / or Msg B. The second message may be a response to the first message.

[0392] exist Figure 19 In the example, the base station may determine not to configure / allow the next SDT. In the example, the base station may determine to complete the SDT. Based on the determination to configure the next SDT, the second message may indicate that the next SDT is not configured. Based on the determination that the next SDT is not configured, the second message may indicate that the SDT is completed. The second message may include an RRC release message. Based on the second message, the UE may complete the SDT. Based on the second message, the UE may remain in and / or transition (back) to an RRC inactive state or an RRC idle state. The second message may include an RRC setup / resumption message. Based on the second message, the UE may transition to an RRC connected state.

[0393] exist Figure 19In the example of , the base station may determine to configure / allow a subsequent SDT. Based on determining to configure the subsequent SDT, the base station may send a second message to the wireless device. For example, the second message may indicate the subsequent SDT. The second message may indicate an uplink grant. For example, the uplink grant may indicate the subsequent SDT. The uplink grant may be used for the subsequent SDT. Based on the second message, the UE may perform the subsequent SDT. The subsequent SDT may include transmitting and / or receiving data and / or signals (e.g., control signals). The transmission and / or reception may be based on the uplink grant. The subsequent SDT may be performed without transitioning to an RRC connected state (e.g., when in an RRC idle state or RRC inactive). The second message may not include an RRC setup / recovery message (which will transition the UE to an RRC connected state). The second message may not include an RRC release message (which will complete the SDT).

[0394] exist Figure 19 In an example, the second message may indicate that the contention resolution of the wireless device is successful. For example, the second message may include a UE contention resolution identifier (MAC CE). The UE contention resolution identifier media access control element (MAC CE) may match a predetermined first bit (e.g., the first bit of 48) of a common control channel (CCCH) service data unit (SDU), where the CCCH SDU includes the RRC request message. Based on receiving the second message, the wireless device may determine that the C-RNTI of the serving cell is assigned. The wireless device may (start) monitoring the PDCCH of the serving cell. The wireless device may (start) monitoring the PDCCH of the BWP configured for the SDT, where the BWP is the BWP of the serving cell. The PDCCH may be a PDCCH addressed by the C-RNTI.

[0395] exist Figure 19In the example of , the second message may be a (physical) downlink message (e.g., DCI). The physical message may instruct the wireless device to start monitoring the window for the next SDT. For example, the wireless device may transmit a first message to the base station using the CG configured for the SDT (or PUR). Based on the transmission, the wireless device may (start) monitoring the start of the CG response window timer using the CG response window time. Based on the start, the UE may monitor the PDCCH identified by the RNTI of the CG (e.g., CS RNTI, or PURRNTI, or C-RNTI) until the CG response window timer expires. The UE (UE-MAC entity) may receive a downlink message (e.g., DCI) identified by the RNTI of the CG on the PDCCH. Based on the downlink message, the wireless device may start a second CG response window timer or restart the CG response window timer. Based on the start or restart, the wireless device may monitor the PDCCH identified by the RNTI of the CG. The base station may transmit a downlink message to control the CG response window of the wireless device. The downlink message may indicate an extension or restart of the CG response window. For example, the downlink message may indicate the next SDT. The base station can control / modify the period of the (next) SDT via a downlink message. Based on the downlink message, the wireless device determines to initiate the next SDT (or continue SDT). When the wireless device monitors the PDCCH on the CG response window, the base station can communicate with the wireless device.

[0396] exist Figure 19 In an example, during an SDT process, the wireless device may transmit one or more data or signals to the base station. During the SDT process, the wireless device may receive one or more data or signals from the base station. During the SDT process, the wireless device may transmit a request for uplink resources / grants for subsequent data / signals to the base station. For example, the request may be a BSR indicating information about subsequent data / signal capacity (e.g., uplink data / signal capacity). Based on the request, the base station may provide uplink resources to the wireless device. Based on the request, the base station may determine to transition the wireless device to an RRC connected state. Based on the determination, the base station may transmit an RRC response message to the wireless device, the RRC response message transitioning the wireless device to the RRC connected state. For example, the RRC response message may be an RRC resume message.

[0397] exist Figure 19In an example, during the SDT procedure, the base station may determine that the SDT procedure is complete. Based on this determination, the base station may transmit a message to the wireless device terminating the SDT procedure. Based on this message, the wireless device may complete the SDT procedure. Based on this message, the wireless device may remain in a non-connected state and / or transition back to a non-connected state (e.g., from an RRC inactive state to an RRC idle state). For example, the message may be an RRC release message. For example, the message may be a second RRC message. The second RRC message may be an RRC response message in response to the RRC request message (of the first message).

[0398] exist Figure 19 In an example, the wireless device may configure an SDT configuration. The SDT configuration may include configurations of one or more layers, wherein the one or more layers include at least one of the following: an RRC layer; a PDCP layer, an RLC layer; a MAC layer; and a PHY layer. For example, the SDT configuration may include at least one of the following: a BWP for SDT; a search space; and a RACH configuration. The RACH configuration may indicate RACH resources for an SDT procedure (or an initial SDT). The RACH resources may include at least one of the following: a RACH opportunity (RO) and an RA preamble. The wireless device may use the RACH configuration to perform a random access procedure during the SDT procedure (or the initial SDT or the initial transmission). The wireless device may use the SDT configuration to perform the SDT procedure. Based on the completion or termination of the SDT or a subsequent SDT, the wireless device may suspend or release the SDT configuration.

[0399] Figure 20A An example of time window management for one or more subsequent transmissions of an SDT according to aspects of an embodiment of the present disclosure is shown. A wireless device may receive a message (e.g., an RRC release message) including and / or indicating configuration parameters for an SDT. The configuration parameters may indicate an uplink grant for the SDT and / or one or more uplink radio resources for the uplink grant. Figure 20A In the embodiment, the first SDT and the second SDT are transmitted via an uplink grant and / or one or more uplink radio resources with a periodicity. The wireless device may (restart) the start time window in response to transmitting uplink data via the uplink grant and / or one or more uplink radio resources. For example, the wireless device may (restart) the start time window in response to executing Figure 20AThe time window may be (re)started for the first SDT in the time window. The message may include the value of the time window. The wireless device may monitor the PDCCH using one or more RNTIs during the time window. The one or more RNTIs may be predefined and / or configured by the base station (e.g., indicated by one or more RRC messages that may include the message) for PDCCH monitoring in the SDT and / or non-RRC connected state (non-connected state). For example, the one or more RNTIs may include a C-RNTI. The one or more RNTIs may include an SDT-RNTI. The one or more RNTIs may include a P-RNTI (e.g., an RNTI for a paging message). During the time window, the wireless device may receive one or more DCIs via the PDCCH. The one or more DCIs may include a UL grant scheduling a new UL transmission. The one or more DCIs may include a UL grant scheduling a UL (re)transmission. The one or more DCIs may include a DL grant scheduling a new DL transmission. The one or more DCIs may include a DL grant scheduling a DL (re)transmission. The wireless device may maintain the running time window independently of receiving the one or more DCIs and / or independently of performing UL and / or DL ​​new transmissions and / or (re)transmissions. For example, the wireless device may not stop or (re)start the time window in response to receiving one or more DCIs and / or in response to performing UL and / or DL ​​new transmissions and / or (re)transmissions. The wireless device may continue to monitor (and / or maintain monitoring) the PDCCH until the time window expires. The wireless device may stop monitoring the PDCCH in response to the expiration of the time window.

[0400] The wireless device may maintain a time window for an SDT and / or one or more subsequent transmissions of the SDT. The wireless device may receive a message (e.g., an RRC release message) from a base station including a value (e.g., a length) of the time window. The value may indicate a time period (or interval) during which the wireless device performs (e.g., is permitted to perform) the SDT and / or one or more subsequent transmissions of the SDT. The value may indicate a time period (or interval) during which the wireless device monitors (e.g., is permitted to monitor) the PDCCH to receive new UL and / or DL ​​transmissions and / or retransmissions of the SDT and / or one or more UL and / or DL ​​grants for one or more subsequent transmissions of the SDT. The wireless device may receive one or more DCIs via the PDCCH. The one or more DCIs may include one or more UL and / or DL ​​grants. The wireless device may (re)start the time window in response to receiving a grant (e.g., a UL grant and / or a DL grant) for the one or more DCIs. The wireless device may (re)start the time window in response to performing a transmission scheduled by a grant (e.g., a UL grant and / or a DL grant) for the SDT and / or one or more subsequent transmissions of the SDT. The wireless device may stop monitoring the PDCCH in response to expiration of the time window. The wireless device may cease performing the SDT and / or one or more subsequent transmissions of the SDT in response to expiration of the time window.

[0401] Figure 20B An example of time window management for one or more subsequent transmissions of an SDT according to aspects of an embodiment of the present disclosure is shown. A wireless device may receive a message (e.g., an RRC release message) including and / or indicating configuration parameters for an SDT. The configuration parameters may indicate an uplink grant for the SDT and / or one or more uplink radio resources for the uplink grant. Figure 20B In the embodiment, the first SDT and the second SDT are transmitted via an uplink grant and / or one or more uplink radio resources with a periodicity. The wireless device may (restart) the start time window in response to transmitting uplink data via the uplink grant and / or one or more uplink radio resources. For example, the wireless device may (restart) the start time window in response to executing Figure 20BThe message may include a value for the first time window. The wireless device may monitor the PDCCH using one or more RNTIs during the first time window. The one or more RNTIs may be predefined and / or configured by the base station (e.g., indicated by one or more RRC messages that may include the message) for PDCCH monitoring for the SDT and / or non-RRC connected state. For example, the one or more RNTIs may include a C-RNTI. The one or more RNTIs may include an SDT-RNTI. The one or more RNTIs may include a P-RNTI (e.g., an RNTI for a paging message). During the first time window, the wireless device may receive a first DCI via the PDCCH. The first DCI may include a UL grant scheduling a new UL transmission. The first DCI may include a UL grant scheduling a UL (re)transmission of the first SDT. The first DCI may include a DL grant scheduling a new DL transmission. The wireless device may restart the second time window in response to receiving the first DCI and / or in response to performing an UL or DL ​​transmission scheduled by the first DCI. The second time window may have the same length as the first time window. For example, the wireless device may (re)start the first time window as the second time window in response to receiving the first DCI and / or in response to performing an UL or DL ​​transmission scheduled by the first DCI. The wireless device may monitor the PDCCH using one or more RNTIs during the second time window. The wireless device may (re)start a new time window and / or (re)start the first time window in response to receiving the DCI and / or in response to performing a transmission scheduled by the DCI. Figure 20B In the embodiment of the present invention, the wireless device may (re)start the third time window in response to receiving the second DCI during the second time window and / or in response to performing the UL or DL ​​transmission scheduled by the second DCI. The third time window may be the first time window that the wireless device (re)starts in response to receiving the second DCI during the second time window and / or in response to performing the UL or DL ​​transmission scheduled by the second DCI. The wireless device may keep monitoring the PDCCH while the time windows (e.g., the first time window, the second time window, and / or the third time window) started for the SDT and / or its associated subsequent transmissions are running. If the time window expires, the wireless device may stop monitoring the PDCCH with one or more RNTIs. For example, in Figure 20B In the embodiment of the present invention, if the wireless device has not received DCI (eg, introduced based on one or more RNTIs) and / or if the third time window expires, the wireless device may stop monitoring the PDCCH.

[0402] For example, the response (e.g., the second message) to the RRC request message may be an RRC release message. For example, the wireless device may maintain the RRC state of the wireless device in a non-RRC connected state after or in response to receiving the response (e.g., the RRC release message). For example, the wireless device may stop monitoring the PDCCH using one or more RNTIs associated with the SDT and / or one or more subsequent transmissions, for example, after or in response to receiving the response (e.g., the RRC release message). The wireless device may stop the time window (if running) after or in response to receiving the response (e.g., the RRC release message). For example, the wireless device may not (re)start the time window (e.g., after or in response to receiving the response (e.g., the RRC release message). Figure 20A and / or Figure 20B ).

[0403] For example, the response to the RRC request message may be an RRC connection setup message. For example, the RRC connection setup message may include an RRC resume message, an RRC (re)establishment message, an RRC setup message, and / or an RRC message including parameters indicating that the wireless device transitions from a non-RRC connected state to an RRC connected state. For example, the wireless device may transition the RRC state of the wireless device from a non-RRC connected state to an RRC connected state after receiving a response (e.g., an RRC connection setup message) or in response to receiving a response. For example, the wireless device may determine, for example, that a transmission group is successfully completed and / or terminated after receiving a response (e.g., an RRC connection setup message) or in response to receiving a response. For example, the wireless device may stop monitoring the PDCCH using one or more RNTIs associated with the SDT and / or one or more subsequent transmissions, for example, after receiving a response (e.g., an RRC connection setup message) or in response to receiving a response. For example, the wireless device may operate in response to a time window and / or stop a time window ...

Claims

1. A method for communication, comprising: A radio resource control (RRC) release message is received by a wireless device from a base station, the RRC release message including: a measurement configuration for performing one or more measurements by the wireless device while the wireless device is in an RRC inactive state; and an SDT configuration for a small data transfer (SDT) procedure transmitted by the wireless device while the wireless device is in the RRC inactive state; and When the wireless device is in the RRC inactive state, based on the RRC release message: Initiating the SDT process based on the SDT configuration; and Based on initiating the SDT procedure, measurements associated with the measurement configuration are not performed.

2. The method of claim 1 , further comprising performing, by the wireless device, the measurements associated with the measurement configuration, wherein performing the measurements is: After the wireless device is in an RRC inactive state; and Before the wireless device initiates the SDT process.

3. The method of claim 2, wherein the measuring is performed based on one or more of: receiving the RRC release message; or The wireless device is in the RRC inactive state. 4 . The method of claim 1 , further comprising transitioning, by the wireless device, to the RRC inactive state based on the RRC release message. 5 . The method according to claim 1 , wherein the measurement configuration comprises a carrier frequency list and / or a validity area list. 6 . The method according to claim 1 , further comprising starting, by the wireless device, a measurement timer based on the RRC release message.

7. The method of claim 6, wherein the measurement timer is one or more of: A timer for measuring in the RRC inactive state; or T331。 8. The method according to one of claims 6 to 7, further comprising: When the measurement timer runs, the wireless device performs the measurement associated with the measurement configuration based on the RRC release message.

9. The method according to one of claims 1 to 8, further comprising performing, by the wireless device, the measurements associated with the measurement configuration based on the RRC release message.

10. The method of one of claims 1 to 9, further comprising transmitting, by the wireless device, one or more results of the one or more measurements associated with the measurement configuration based on: Initiate the SDT process; or The measurements associated with the measurement configuration are not performed.

11. The method of one of claims 1 to 10, wherein the SDT configuration comprises at least one of: Next hop link count NCC; A recovery identifier for the wireless device; and An indication of the radio bearers configured for the SDT process.

12. The method of one of claims 1 to 11, wherein initiating the SDT process is based on one or more of the following: receiving, by the wireless device, a paging message indicating the SDT process; and / or The data of the SDT process can be used by the wireless device.

13. The method according to claim 1, wherein: The wireless device supports carrier aggregation and / or dual connectivity; and / or The measurement configuration is used for the carrier aggregation and / or the dual connectivity of the wireless device.

14. A wireless device comprising one or more processors and a memory storing instructions which, when executed by the one or more processors, cause the wireless device to perform the method of any one of claims 1 to 13.

15. A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform the method of any one of claims 1 to 13.

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