Type of random access free cell handover

Abstract

A wireless device receives, from a base station, a signal indicating a type of RACH-free cell handover to a target cell, wherein the type of RACH-free cell handover includes a first type of RACH-free cell handover associated with a configured grant (CG)-based RACH-free cell handover or a second type of RACH-free cell handover associated with a dynamic grant (DG)-based RACH-free cell handover. The wireless device performs a RACH-free cell handover to the target cell based on the type of RACH-free cell handover indicated by the signal.

Description

Cross-references to related applications

[0001] This application claims priority to U.S. Provisional Application No. 63 / 532,008, filed August 10, 2023, the entire contents of which are incorporated herein by reference. Attached Figure Description

[0002] Examples of several embodiments of the various embodiments of this disclosure are described herein with reference to the accompanying drawings.

[0003] Figure 1A and Figure 1B An example mobile communication network in which embodiments of the present disclosure can be implemented is shown.

[0004] Figure 2A and Figure 2B The protocol stacks for the New Radio (NR) user plane and control plane are shown respectively.

[0005] Figure 3 It shows in Figure 2A An example of the services provided between the protocol layers of the NR user plane protocol stack.

[0006] Figure 4A It shows the flow through Figure 2A Example downlink data stream of the NR user plane protocol stack.

[0007] Figure 4B This shows an example format of the MAC subheader in a MAC PDU.

[0008] Figure 5A and Figure 5B The mappings between logical channels, transport channels, and physical channels used for downlink and uplink are shown respectively.

[0009] Figure 6 This is an example diagram illustrating the RRC state transition of the UE.

[0010] Figure 7 An example configuration is shown in which OFDM symbols are grouped into NR frames.

[0011] Figure 8 An example configuration of time slots in the time and frequency domains of an NR carrier is shown.

[0012] Figure 9 An example of bandwidth adaptation using three configured BWPs with NR carriers is shown.

[0013] Figure 10A Three carrier aggregation configurations with two component carriers are shown.

[0014] Figure 10BAn example is shown of how aggregated cells can be configured into one or more PUCCH groups.

[0015] Figure 11A An example of the SS / PBCH block structure and location is shown.

[0016] Figure 11B An example of CSI-RS mapped in the time and frequency domains is shown.

[0017] Figure 12A and Figure 12B Examples of three downlink and uplink beam management procedures are shown respectively.

[0018] Figure 13A , Figure 13B and Figure 13C Four-step contention-based random access procedures, two-step contention-free random access procedures, and another two-step random access procedure are shown respectively.

[0019] Figure 14A An example of the CORESET configuration for the bandwidth portion is shown.

[0020] Figure 14B An example of CCE-to-REG mapping for DCI transport is shown on CORESET and PDCCH processing.

[0021] Figure 15 An example of a wireless device communicating with a base station is shown.

[0022] Figure 16A , Figure 16B , Figure 16C and Figure 16D An example structure for uplink and downlink transmission is shown.

[0023] Figure 17 An example of an RRC connection reconstruction procedure is shown.

[0024] Figure 18 An example of an RRC connection recovery procedure is shown.

[0025] Figure 19 An example of a measurement model of a wireless device as one aspect of an embodiment of this disclosure is shown.

[0026] Figure 20 An example of Layer 3 (L3) switching of a wireless device is shown.

[0027] Figure 21 An example of an RRC message used for switching (HO) is shown.

[0028] Figure 22An example of an RRC message for RACH resource configuration used in a HO procedure is shown.

[0029] Figure 23 An example of a Conditional Hitch (CHO) procedure is shown.

[0030] Figure 24 An example of an RRC message used for CHO is shown.

[0031] Figure 25 An example of a connection restoration procedure with a conditional switching configuration is shown.

[0032] Figure 26 An example of adding / changing procedures in a conditional PSCell is shown.

[0033] Figure 27 An example of the MCG fault information program is shown.

[0034] Figure 28 An example of L1 / L2 triggering mobility is shown.

[0035] Figure 29 An example of L1 / L2 triggering mobility within a DU is shown.

[0036] Figure 30 An example of L1 / L2-triggered mobility between DUs is shown.

[0037] Figure 31A and Figure 31B An example of a timeline for PCell switching is shown.

[0038] Figure 32 An example of early TA acquisition for L1 / L2-triggered mobility between DUs is shown.

[0039] Figure 33 An example of the capabilities of a wireless device is shown.

[0040] Figure 34 An example of resource allocation for early TA acquisition is shown.

[0041] Figure 35A An example of RACH-free handover with configuration-based uplink permission is shown.

[0042] Figure 35B An example of RACH-free handover based on dynamic uplink permission is shown.

[0043] Figure 36A An example of intra-BS (or intra-CU) cell handover in a CU-DU split architecture is shown.

[0044] Figure 36BAn example of inter-BS (or inter-CU) cell handover in a CU-DU split architecture is shown.

[0045] Figure 37 An example of a parameter indicating the type of cell handover without RACH is shown.

[0046] Figure 38A An example of configuration parameters for DG-based RACH-free cell handover is shown.

[0047] Figure 38B An example of configuration parameters for CG-based RACH-free cell handover is shown.

[0048] Figure 39 An example of RACH-free cell handover within a BS in a CU-DU split architecture is shown.

[0049] Figure 40 An example of RACH-free cell handover between BSs in a CU-DU split architecture is shown.

[0050] Figure 41 An example of a type modification initiated by a DU is shown.

[0051] Figure 42A An example of the process by which the CU initiates a type of handover for a cell without RACH is shown.

[0052] Figure 42B An example of the process by which the DU initiates a type of handover for a cell without RACH is shown.

[0053] Figure 43 An example of a type change during cell handover without RACH is shown.

[0054] Figure 44 An example of a signal indicating a type of cell handover without RACH is shown.

[0055] Figure 45A An example of a service DU transmission indicating a type of message without RACH cell handover is shown.

[0056] Figure 45B An example of a CU transmission message indicating a type of cell handover without RACH is shown.

[0057] Figure 46 Examples of messages and signals indicating the type of cell handover without RACH are shown.

[0058] Figure 47A Examples of service DU and indications of the type of handover without RACH are shown.

[0059] Figure 47BExamples of CU and indications of the type of cell handover without RACH are shown. Detailed Implementation

[0060] In this disclosure, various embodiments are presented as examples of how the disclosed techniques can be implemented and / or how the disclosed techniques can be practiced in environments and scenarios. It will be apparent to those skilled in the art that various changes in form and detail can be made therein without departing from the scope of the invention. Indeed, after reading the specification, it will be apparent to those skilled in the art how to implement alternative embodiments. Embodiments of the invention should not be limited to any of the described exemplary embodiments. Embodiments of this disclosure will be described with reference to the accompanying drawings. Limitations, features, and / or elements from the disclosed exemplary embodiments can be combined to create additional embodiments within the scope of this disclosure. Any diagrams highlighting functionality and advantages are given for illustrative purposes only. The disclosed architecture is flexible and configurable enough that it can be utilized in ways other than those shown. For example, any actions listed in any flowchart can be reordered or used only optionally in certain embodiments.

[0061] The implementation scheme can be configured to operate as needed. For example, in wireless devices, base stations, radio environments, networks, combinations thereof, etc., the disclosed mechanisms can be executed when certain criteria are met. Example criteria may be based at least in part on, for example, wireless device or network node configuration, traffic load, initial system setup, packet size, service characteristics, combinations thereof, etc. Various example implementation schemes can be applied when one or more criteria are met. Therefore, example implementation schemes that selectively implement the disclosed protocols can be implemented.

[0062] A base station can communicate with a hybrid of wireless devices. Wireless devices and / or base stations can support multiple technologies and / or multiple versions of the same technology. Wireless devices may have certain specific capabilities, depending on the wireless device category and / or capabilities. When this disclosure refers to a base station communicating with multiple wireless devices, this disclosure may refer to a subset of the total number of wireless devices in the coverage area. For example, this disclosure may refer to multiple wireless devices having a given capability and a given LTE or 5G version in a given sector of a base station. Multiple wireless devices in this disclosure may refer to a selected set of wireless devices, and / or a subset of the total number of wireless devices in the coverage area performing according to the disclosed method, etc. Multiple base stations or multiple wireless devices may exist in the coverage area that may not conform to the disclosed method; for example, these wireless devices or base stations may be based on older versions of LTE or 5G technology.

[0063] In this disclosure, “a(a)” and “an(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 interpreted as “may, for example.” In other words, the term “may” indicates that the phrase following the term “may” is an example of one of a variety of suitable possibilities that may or may not be used in one or more of the various embodiments. As used herein, the terms “comprising” and “consisting of” enumerate one or more components of the element being described. The terms “comprising” and “including” are interchangeable and do not exclude the inclusion of unlisted components in the element being described. In contrast, “consisting of” provides a complete enumeration of the one or more components of the element being described. As used herein, the term “based on” should be interpreted as “at least partially based on” rather than, for example, “based on only.” As used herein, the term “and / or” indicates any possible combination of the enumerated 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.

[0064] 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, possible subsets of B = {cell1, cell2} are: {cell1}, {cell2}, and {cell1, cell2}. The phrase “based on” (or equivalently “at least based on”) indicates that the phrase following the term “based on” is an example of one of a variety of suitable possibilities that may or may not be used for one or more different implementations. The phrase “in response to” (or equivalently “at least in response to”) indicates that the phrase following the phrase “in response to” is an example of one of a variety of suitable possibilities that may or may not be used for one or more different implementations. The phrase “depends on” (or equivalently “at least depends on”) indicates that the phrase following the phrase “depends on” is an example of one of a variety of suitable possibilities that may or may not be used for one or more different implementations. The phrase “adopts / uses” (or equivalently “at least adopts / uses”) indicates that the phrase following the phrase “adopts / uses” is an example of one of a variety of suitable possibilities that may or may not be used for one or more different implementations.

[0065] The term "configured" can refer to the capabilities of a device, whether the device is in an operational or non-operational state. "Configured" can refer to specific settings within the device that affect its operational characteristics, regardless of 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 the device to provide specific characteristics to the device, whether the device is in an operational or non-operational state. Similarly, the term "control messages generated in the device" can mean that the control messages have parameters that can be used to configure specific characteristics in the device or to perform certain actions in the device, regardless of whether the device is in an operational or non-operational state.

[0066] In this disclosure, a parameter (or equivalently referred to as a field or information element: IE) may contain one or more information objects, and an information object may contain one or more other objects. For example, if parameter (IE)N contains parameter (IE)M, and parameter (IE)M contains parameter (IE)K, and parameter (IE)K contains parameter (information element)J, then, for example, N contains K, and N contains J. In an example implementation, when one or more messages contain multiple parameters, it means that a parameter among the multiple parameters is present in at least one of the one or more messages, but not necessarily in every one of the one or more messages.

[0067] Many of the proposed features are described as optional using the word "may" or parentheses. For brevity and readability, this disclosure does not explicitly describe every permutation that can be obtained by selecting from the group 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: having only one of the three possible features, having any two of the three possible features, or having three of the three possible features.

[0068] Many elements described in the disclosed embodiments can be implemented as modules. A module is defined herein as an element that performs the defined function and has the defined interface to other elements. Modules described in this disclosure can be implemented as hardware, software combined with hardware, firmware, wet hardware (e.g., hardware with biological elements), or combinations thereof, all of which may be behaviorally equivalent. For example, a module can be implemented as a software routine written in a computer language configured to be executed by a hardware machine (such as C, C++, Fortran, Java, Basic, Matlab, etc.) or a modeling / simulation program (such as Simulink, Stateflow, GNU Octave, or LabVIEW MathScript). It is possible to implement modules using physical hardware incorporating 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 typically programmed using hardware description languages ​​(HDLs), such as VHSIC Hardware Description Language (VHDL) or Verilog. These languages ​​configure the connections between internal hardware modules with limited functionality on the programmable device. The aforementioned techniques are often used in combination to achieve the result of functional modules.

[0069] Figure 1A An example of a mobile communication network 100 in which embodiments of the present disclosure may be implemented is shown. The mobile communication network 100 may, for example, be a Public Land Mobile Network (PLMN) operated by a network operator. Figure 1A As shown, the mobile communication network 100 includes a core network (CN) 102, a radio access network (RAN) 104, and a wireless device 106.

[0070] CN 102 can provide the wireless device 106 with an interface to one or more data networks (DNs) (such as public DNs (e.g., the Internet), private DNs, and / or carrier-internal DNs). As part of the interface functionality, CN 102 can establish an end-to-end connection between the wireless device 106 and one or more DNs, authenticate the wireless device 106, and provide charging functionality.

[0071] RAN 104 can connect CN 102 to radio device 106 via radio communication through an air interface. As part of the radio communication, RAN 104 can provide scheduling, radio resource management, and retransmission protocols. The communication direction from RAN 104 to radio device 106 via the air interface is referred to as the downlink, while the communication direction from radio device 106 to RAN 104 via the air interface is referred to as the uplink. Downlink transmissions can be separated from uplink transmissions using Frequency Division Duplex (FDD), Time Division Duplex (TDD), and / or some combination of the two duplexing technologies.

[0072] The term "wireless device" may be used throughout this disclosure to mean and cover any mobile or fixed (non-mobile) device that requires or can use wireless communication. For example, a wireless device may be a telephone, smartphone, tablet, computer, laptop computer, sensor, instrument, wearable device, Internet of Things (IoT) device, roadside unit (RSU) of a vehicle, relay node, automobile, and / or any combination thereof. The term "wireless device" also encompasses other terms including user equipment (UE), user terminal (UT), access terminal (AT), mobile station, handheld device, wireless transmit and receive unit (WTRU), and / or wireless communication device.

[0073] RAN 104 may include one or more base stations (not shown). The term "base station" may be used throughout this disclosure to mean and encompass: Node B (associated with UMTS and / or 3G standards); Evolved Node B (eNB, associated with E-UTRA and / or 4G standards); Remote Radio Header (RRH); Baseband Processing Unit coupled to one or more RRHs; Repeater Node or Relay Node for extending the coverage area of ​​the donor node; Next Generation Evolved Node B (ng-eNB); First Generation Node B (gNB, associated with NR and / or 5G standards); 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).

[0074] The base stations included in RAN 104 may include one or more sets of antennas for communicating with wireless device 106 via an 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 the cells may be determined by the range within which a receiver (e.g., a base station receiver) can successfully receive transmissions from a transmitter (e.g., a wireless device transmitter) operating within the cell. The cells of the base stations may together provide radio coverage over a wide geographical area to wireless device 106 to support wireless device mobility.

[0075] Besides three-sector sites, other implementations of the base stations are also possible. For example, one or more base stations in RAN 104 can be implemented as sectorized sites with more or fewer than three sectors. One or more base stations in RAN 104 can be implemented as access points, baseband processing units coupled to several remote radio heads (RRHs), and / or repeater or relay nodes for extending the coverage area of ​​the donor node. The baseband processing unit coupled to the RRH can be part of a centralized or cloud RAN architecture, where the baseband processing unit can be centralized in a pool of baseband processing units or virtualized. Repeater nodes can amplify and replay radio signals received from the donor node. Relay nodes can perform the same / similar functions as repeater nodes, but can decode the radio signals received from the donor node to remove noise before amplifying and replaying the radio signals.

[0076] RAN 104 can be deployed as a homogeneous network of macrocell base stations with similar antenna configurations and similar high-level transmission power. 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 overlapping with the relatively large coverage areas provided by macrocell base stations. Small coverage areas can be provided in areas with high data traffic (or so-called "hot spots") or in areas where macrocell coverage is weak. Examples of small cell base stations, in descending order of coverage area, include: microcell base stations, picocell base stations, and femtocell base stations or femtocell base stations.

[0077] The Third Generation Partnership Project (3GPP) was established in 1998 to facilitate collaboration with... Figure 1A The mobile communication network 100 in this disclosure provides global standardization for similar mobile communication networks. To date, 3GPP has defined specifications for three generations of mobile networks: the third-generation (3G) network known as Universal Mobile Telecommunications System (UMTS), the fourth-generation (4G) network known as Long Term Evolution (LTE), and the fifth-generation (5G) network known as 5G System (5GS). The embodiments of this disclosure are described with reference to the RAN of the 3GPP 5G network, known as Next Generation RAN (NG-RAN). These embodiments can be applied to the RAN of other mobile communication networks, such as... Figure 1A RAN 104, the RAN of early 3G and 4G networks, and those RANs of future networks that have not yet been specified (e.g., 3GPP 6G networks). NG-RAN implements 5G radio access technology known as New Radio (NR) and can be configured to implement 4G radio access technology or other radio access technologies, including non-3GPP radio access technologies.

[0078] Figure 1BAnother example mobile communication network 150 in which embodiments of the present disclosure can be implemented is shown. The mobile communication network 150 may be, for example, a PLMN operated by a network operator. Figure 1B As shown, the 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). This can be compared with... Figure 1A These components are implemented and operated in the same or similar manner as the corresponding components described.

[0079] 5G-CN 152 provides UE 156 with an interface to one or more DNs, such as public DNs (e.g., the Internet), private DNs, and / or operator-internal DNs. As part of the interface functionality, 5G-CN 152 can establish end-to-end connections between UE 156 and the one or more DNs, authenticate UE 156, and provide charging functions. Compared to the CNs in 3GPP 4G networks, the foundation of 5G-CN 152 can be a service-based architecture. This means that the architecture of the nodes constituting 5G-CN 152 can be defined as network functions that provide services to other network functions via the interface. The network functions of 5G-CN 152 can 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).

[0080] like Figure 1B As shown, 5G-CN 152 includes Access and Mobility Management Functions (AMF) 158A and User Plane Functions (UPF) 158B. For ease of explanation, in Figure 1B These are shown as a single component, AMF / UPF 158. UPF 158B can act as a gateway between NG-RAN 154 and the one or more DNs. Functions that UPF 158B can perform include: packet routing and forwarding, packet inspection and user plane policy rule enforcement, service usage reporting, uplink classification supporting the 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 authentication), 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 interconnecting with the one or more DNs, and / or a pivot point supporting multihomed PDU sessions. UE 156 can be configured to receive services via a PDU session, which is a logical connection between the UE and the DN.

[0081] The AMF 158A can perform functions such as: Non-Access Layer (NAS) signaling termination, NAS signaling security, Access Layer (AS) security control, inter-CN node signaling for mobility between 3GPP access networks, idle mode UE reachability (e.g., paging retransmission control and execution), registration area management, intra-system and inter-system mobility support, access authentication, access authorization including roaming rights verification, mobility management control (subscription and policies), network slicing support, and / or Session Management Function (SMF) selection. NAS can refer to functions operating between the CN and the UE, and AS can refer to functions operating between the UE and the RAN.

[0082] 5G-CN 152 may include, for clarity Figure 1B One or more additional network functions not shown in the diagram. For example, 5G-CN 152 may include one or more of the following: Session Management Function (SMF), NR Repository Function (NRF), Policy Control Function (PCF), Network Open Function (NEF), Unified Data Management (UDM), Application Function (AF), and / or Authentication Server Function (AUSF).

[0083] NG-RAN 154 can connect 5G-CN 152 to UE 156 via radio communication over an air interface. NG-RAN 154 may include: one or more gNBs, denoted as gNB 160A and gNB 160B (collectively referred to as gNB 160); and / or one or more ng-eNBs, denoted as ng-eNB 162A and ng-eNB 162B (collectively referred to as ng-eNB 162). gNB 160 and ng-eNB 162 may be more generally referred to as base stations. gNB 160 and ng-eNB 162 may include one or more sets of antennas for communicating with 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 sets of antennas to control three cells (or sectors) respectively. The gNB 160 and ng-eNB 162 cells can work together to provide UE 156 with radio coverage over a wide geographical area to support UE mobility.

[0084] like Figure 1BAs shown, gNB 160 and / or ng-eNB 162 can connect to 5G-CN 152 via the NG interface and to other base stations via the Xn interface. The NG and Xn interfaces can be established using a direct physical connection and / or an indirect connection via an underlying transport network (such as an Internet Protocol (IP) transport network). gNB 160 and / or ng-eNB 162 can connect to UE 156 via the Uu interface. For example, as... Figure 1B As shown, the gNB 160A can connect to the UE156A via the Uu interface. The NG, Xn, and Uu interfaces are associated with a protocol stack. The protocol stack associated with the interface can be... Figure 1B The network elements in the system are used to exchange data and signaling messages, and can include two planes: a user plane and a control plane. The user plane can handle data that is of interest to the user. The control plane can handle signaling messages that are of interest to the network elements.

[0085] The gNB 160 and / or ng-eNB 162 can connect to one or more AMF / UPF functions of the 5G-CN 152, such as AMF / UPF 158, via one or more NG interfaces. For example, the gNB 160A can connect to the UPF 158B of the AMF / UPF 158 via an NG user plane (NG-U) interface. The NG-U interface can provide user plane PDU delivery (e.g., non-guaranteed delivery) between the gNB 160A and the UPF 158B. The gNB 160A can connect to the AMF 158A via an NG control plane (NG-C) interface. The NG-C interface can provide, for example, NG interface management, UE context management, UE mobility management, NAS message delivery, paging, PDU session management, and configuration delivery and / or warning message transmission.

[0086] The gNB 160 can provide NR user plane and control plane protocol termination to UE 156 via the Uu interface. For example, the gNB 160A can provide NR user plane and control plane protocol termination to UE 156A via the 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 UE 156 via the Uu interface, where E-UTRA refers to 3GPP 4G radio access technology. For example, the ng-eNB 162B can provide E-UTRA user plane and control plane protocol termination to UE 156B via the Uu interface associated with the second protocol stack.

[0087] 5G-CN 152 is described as being configured to handle NR and 4G radio access. Those skilled in the art will understand that NR can potentially connect to the 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 The diagram shows only one AMF / UPF 158, but a gNB or ng-eNB can connect to multiple AMF / UPF nodes to provide redundancy and / or load sharing across those multiple AMF / UPF nodes.

[0088] As discussed, Figure 1B The interfaces between network elements (e.g., Uu, Xn, and NG interfaces) can be associated with the protocol stack used by the network elements to exchange data and signaling messages. The protocol stack can include two planes: a user plane and a control plane. The user plane handles data of interest to the user, while the control plane handles signaling messages of interest to the network elements.

[0089] Figure 2A and Figure 2B Examples of NR user plane and NR control plane protocol stacks for the Uu interface located between UE 210 and gNB 220 are shown respectively. Figure 2A and Figure 2B The protocol stack shown can be used with, for example, Figure 1B The protocol stacks of the Uu interface between UE156A and gNB 160A shown are the same or similar.

[0090] Figure 2A The diagram illustrates the five-layer NR user plane protocol stack implemented in UE 210 and gNB 220. At the bottom of the stack, the Physical Layer (PHY) 211 and 221 provide transport services to the higher layers and correspond to Layer 1 of the Open Systems Interconnection (OSI) model. The next four protocols above PHY 211 and 221 include Media Access Control (MAC) 212 and 222, Radio Link Control (RLC) 213 and 223, Packet Data Convergence Protocol (PDCP) 214 and 224, and Serving Data Application Protocol (SDAP) 215 and 225. These four protocols together constitute Layer 2 or the Data Link Layer of the OSI model.

[0091] Figure 3 This illustrates an example of services provided between protocol layers in the NR user plane protocol stack. From Figure 2A and Figure 3Starting from the top, SDAPs 215 and 225 can perform QoS flow processing. UE 210 can receive services through a PDU session, which can be a logical connection between UE 210 and the DN. The PDU session can have one or more QoS flows. The CN's UPF (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 reflected mapping or control signaling received from gNB 220. For reflective mapping, SDAP 225 at gNB 220 can mark downlink packets with QoS flow indicators (QFIs), which can be observed by SDAP 215 at UE 210 to determine the mapping / demapping between QoS flows and data radio bearers.

[0092] PDCP 214 and 224 can perform header compression / decompression to reduce the amount of data that needs to be transmitted over the air interface, can perform encryption / decryption to prevent unauthorized decoding of data transmitted over the air interface, and can perform integrity protection to ensure that control messages originate from their intended source. PDCP 214 and 224 can perform retransmission of undelivered packets, reordering and repackaging of packets, and removal of duplicate packets received due to, for example, intra-gNB handover. PDCP 214 and 224 can 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.

[0093] although Figure 3 Although not shown, PDCP 214 and 224 can perform mapping / demapping between split radio bearers and RLC channels in a dual connectivity scenario. Dual connectivity is a technique 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 those that occur 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 / demapping split radio bearers between RLC channels belonging to a cell group.

[0094] RLCs 213 and 223 can respectively perform segmentation, retransmission via Automatic Repeat Request (ARQ), and removal of duplicate data units received from MACs 212 and 222. RLCs 213 and 223 can support three transmission modes: Transparent Mode (TM); Unacknowledged Mode (UM); and Acknowledged Mode (AM). Based on the transmission mode the RLC is operating in, the RLC can perform one or more of the aforementioned functions. RLC configuration can be based on the logical channel, independent of the parameter set and / or Transmission Time Interval (TTI) duration. Figure 3 As shown, RLC 213 and 223 can provide RLC channels as services to PDCP 214 and 224, respectively.

[0095] MACs 212 and 222 can perform multiplexing / demultiplexing of logical channels and / or mapping between logical channels and transport channels. Multiplexing / demultiplexing may include multiplexing data units belonging to one or more logical channels into / from transport blocks (TBs) delivered to / from PHYs 211 and 221. MAC 222 can be configured to perform scheduling, scheduling information reporting, and priority processing between UEs by means of dynamic scheduling. Scheduling can be performed for downlink and uplink in gNB 220 (at MAC 222). MACs 212 and 222 can be configured to perform error correction via Hybrid Automatic Repeat Request (HARQ) (e.g., one HARQ entity per carrier in the case of carrier aggregation (CA), priority processing between logical channels of UE 210 by means of logical channel priority ordering, and / or padding. MACs 212 and 222 may support one or more parameter sets and / or transmission timing. In the example, the mapping constraints in logical channel priority ordering can control which set of parameters and / or transmission timing the logical channel can use. For example... Figure 3 As shown, MACs 212 and 222 can provide logical channels as services to RLCs 213 and 223.

[0096] PHYs 211 and 221 can perform transport-to-physical channel mapping and digital and analog signal processing functions for transmitting and receiving information over the air interface. These digital and analog signal processing functions may include, for example, encoding / decoding and modulation / demodulation. PHYs 211 and 221 can perform multi-antenna mapping. For example... Figure 3 As shown, PHYs 211 and 221 can provide one or more transport channels as services to MACs 212 and 222.

[0097] Figure 4A An example downlink data flow is shown that passes through the NR user plane protocol stack. Figure 4AThe diagram illustrates the downlink data flow through the NR user plane protocol stack to generate three IP packets (n, n+1, and m) of two TB at the gNB 220. The uplink data flow through the NR user plane protocol stack can be compared with... Figure 4A The downlink data flow described in the text is similar.

[0098] Figure 4A The downlink data flow begins when SDAP 225 receives three IP packets from one or more QoS flows and maps those three packets to a radio bearer. Figure 4A In SDAP 225, IP packets n and n+1 are mapped to the first radio bearer 402, and IP packet m is mapped to the second radio bearer 404. The SDAP header (in...) Figure 4A Data units marked with "H" are added to IP packets. Data units originating from / going to a higher protocol layer are called lower protocol layer Service Data Units (SDUs), and data units originating from / going to a lower protocol layer are called higher protocol layer Protocol Data Units (PDUs). Figure 4A As shown, the data unit from SDAP 225 is the SDU of the lower protocol layer PDCP 224 and the PDU of SDAP 225.

[0099] Figure 4A The remaining protocol layers can perform their associated functions (e.g., regarding...). Figure 3 This involves adding the corresponding headers and forwarding their output to the next lower layer. For example, PDCP 224 can perform IP header compression and encryption, and forward its output to RLC 223. RLC 223 can optionally perform fragmentation (e.g., as...). Figure 4A (As shown in the image regarding IP packet m) and forwards its output to MAC 222. MAC 222 can multiplex many RLC PDUs and can attach MAC subheaders to RLC PDUs to form transport blocks. In NR, MAC subheaders can be distributed throughout MAC PDUs, such as... Figure 4A As shown in the diagram. In LTE, the MAC sub-header 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 sub-header can be computed before the complete MAC PDU is assembled.

[0100] Figure 4BAn example format of the MAC subheader in a MAC PDU is shown. The MAC subheader includes: an SDU length field indicating the length (e.g., in bytes) of the MAC SDU to which the MAC subheader corresponds; a Logical Channel Identifier (LCID) field identifying the logical channel from which the MAC SDU originates to assist in the demultiplexing process; a flag (F) indicating the size of the SDU length field; and a reserved bit (R) field for future use.

[0101] Figure 4B The diagram further illustrates a MAC control element (CE) inserted into the MAC PDU by a MAC (such as MAC 223 or MAC 222). For example, Figure 4B This shows two MAC CEs inserted into the MAC PDU. These can be used at the beginning of downlink transmissions within the MAC PDU (e.g., ...). Figure 4B (As shown in the diagram) and a MAC CE is inserted at the end of the uplink transmission of the MAC PDU. MAC CEs can be used for in-band control signaling. Example MAC CEs include: scheduling-related MAC CEs, such as buffer status reports and power headroom reports; activation / deactivation MAC CEs, such as those used for PDCP repeated 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. A MAC subheader with a format similar to that described with respect to the MAC SDU may precede the MAC CE, and the MAC CE may be identified by a reserved value in the LCID field indicating the type of control information included in the MAC CE.

[0102] Before describing the NR control plane protocol stack, we will 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, which will be described later below.

[0103] Figure 5A and Figure 5BThe mappings between logical channels, transport channels, and physical channels are shown for both downlink and uplink. Information is transmitted through channels between the RLC, MAC, and PHY of the NR protocol stack. Logical channels can be used between the RLC and MAC and can be classified as control channels carrying control and configuration information in the NR control plane, or as service channels carrying data in the NR user plane. Logical channels can be classified as dedicated logical channels for 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: The Paging Control Channel (PCCH) is used to carry paging messages for paging UEs whose location is unknown to the network at the cell level. The Broadcast Control Channel (BCCH) is used to carry system information messages in the form of a Master Information Block (MIB) and several System Information Blocks (SIBs), wherein the system information messages can be used by the UE to obtain information about how the cell is configured and how it operates within the cell; The Common Control Channel (CCCH) is used to carry control messages and for random access. A dedicated control channel (DCCH) is used to carry control messages to a specific UE or to carry control messages from a specific UE to configure the UE; and Dedicated Service Channel (DTCH) is used to carry user data to a specific UE or carry user data from a specific UE.

[0104] 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: The paging channel (PCH) is used to carry paging messages originating from the PCCH; Broadcast channel (BCH), which is used to carry MIBs from the BCCH; Downlink Shared Channel (DL-SCH) is used to carry downlink data and signaling messages, including SIBs from BCCH; Uplink Shared Channel (UL-SCH), used to carry uplink data and signaling messages; and The Random Access Channel (RACH) is used to allow a UE to access the network without any prior scheduling.

[0105] The PHY can use physical channels to transfer information between processing levels of the PHY. A physical channel can be a set of associated time-frequency resources used to carry information from one or more transport channels. The PHY can generate control information to support lower-level PHY operations and provide this control information to 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: The Physical Broadcast Channel (PBCH) is used to carry MIBs from the BCH; The Physical Downlink Shared Channel (PDSCH) is used to carry downlink data and signaling messages from the DL-SCH and paging messages from the PCH. The Physical Downlink Control Channel (PDCCH) carries downlink control information (DCI), which may include downlink scheduling commands, uplink scheduling authorizations, and uplink power control commands. The Physical Uplink Shared Channel (PUSCH) is used to carry uplink data and signaling messages from the UL-SCH, and in some cases, uplink control information (UCI) as described below. The Physical Uplink Control Channel (PUCCH) carries a UCI, which may include a HARQ acknowledgment, a Channel Quality Indicator (CQI), a Precoding Matrix Indicator (PMI), a Rank Indicator (RI), and a Scheduling Request (SR); and The Physical Random Access Channel (PRACH) is used for random access.

[0106] Similar to the physical control channel, the physical layer generates physical signals to support low-level physical layer operations. For example... Figure 5A and Figure 5B As shown, 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.

[0107] Figure 2B An example NR control plane protocol stack is shown. Figure 2BAs shown, the NR control plane protocol stack can use the same / similar first four protocol layers as the example 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 has Radio Resource Control (RRC) 216 and 226 and NAS protocols 217 and 237 at the top of the NR control plane protocol stack.

[0108] NAS protocols 217 and 237 can provide control plane functions between UE 210 and AMF 230 (e.g., AMF 158A) or more generally between UE 210 and CN. NAS protocols 217 and 237 can provide control plane functions between UE 210 and AMF 230 via signaling messages known as NAS messages. There is no direct path through which NAS messages can be transmitted between UE 210 and AMF 230. NAS messages can be transmitted using the AS of the Uu and NG interfaces. NAS protocols 217 and 237 can provide control plane functions such as authentication, security, connection setup, mobility management, and session management.

[0109] RRC 216 and 226 can provide control plane functionality between UE 210 and gNB 220, or more generally between UE 210 and RAN. RRC 216 and 226 can provide control plane functionality between UE 210 and gNB 220 via signaling messages known as RRC messages. RRC messages can be transmitted between UE 210 and RAN using signaling radio bearers and the same / similar PDCP, RLC, MAC, and PHY protocol layers. MAC can multiplex control plane and user plane data into the same transport block (TB). RRC 216 and 226 can provide control plane functions such as: broadcasting system information related to AS and NAS; paging initiated by CN or RAN; establishment, maintenance, and release of RRC connections between UE 210 and 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 said reports; detection and recovery of radio link failures (RLFs); and / or NAS messaging. As part of establishing an RRC connection, RRC 216 and 226 can establish an RRC context, which may involve configuring parameters for communication between UE 210 and RAN.

[0110] Figure 6 This is an example diagram illustrating the RRC state transition of the UE. The UE can interact with... Figure 1A The wireless device 106 described in the document Figure 2A and Figure 2B The UE 210 depicted herein is the same as or similar to any other wireless device described in this disclosure. Figure 6 As shown, the UE can be in at least one of three RRC states: RRC connected 602 (e.g., RRC_CONNECTED), RRC idle 604 (e.g., RRC_IDLE), and RRC inactive 606 (e.g., RRC_INACTIVE).

[0111] 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 RAN 104 as depicted herein; Figure 1B One of gNB 160 or ng-eNB 162 described herein; Figure 2A and Figure 2B The gNB 220 depicted in this disclosure; or any other base station described herein. 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 contain parameters 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. When 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 the 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 a handover to a cell of one of the neighboring base stations based on the reported measurements. The RRC state can be changed from RRC connection 602 to RRC idle 604 through connection release procedure 608, or to RRC inactive 606 through connection deactivation procedure 610.

[0112] In RRC idle 604, an RRC context may not have been established for the UE. In RRC idle 604, the UE may not have an RRC connection with the base station. When in RRC idle 604, the UE may be in sleep mode most of the time (e.g., to conserve battery power). The UE may periodically wake up (e.g., once in each discontinuous reception cycle) to monitor paging messages from the RAN. UE mobility can be managed by the UE through a procedure called cell reselection. The RRC state can be transitioned from RRC idle 604 to RRC connected 602 via connection establishment procedure 612, which may involve a random access procedure, as discussed in more detail below.

[0113] In RRC inactivity 606, the previously established RRC context is maintained in both the UE and the base station. This allows for a faster transition to RRC connection 602 with reduced signaling overhead compared to the transition from RRC idle 604 to RRC connected 602. While in RRC inactivity 606, the UE can be in a sleep state, and the UE's mobility can be managed by the UE via cell reselection. The RRC state can transition from RRC inactivity 606 to RRC connected 602 via connection resumption procedure 614, or to RRC idle 604 via connection release procedure 616, which can be the same as or similar to connection release procedure 608.

[0114] RRC states 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 network. The mobility management mechanisms used in RRC Idle 604 and RRC Inactive 606 allow the network to track the UE at the cell group level, so that paging messages can be broadcast on the cells in the cell group where the UE is currently camped, rather than across the entire mobile network. Mobility management mechanisms for RRC Idle 604 and RRC Inactive 606 track the UE at the cell group level. These mobility management mechanisms can do this using groupings of different granularities. For example, there can be three levels of cell grouping granularity: a single cell; cells within a RAN area identified by a RAN Area Identifier (RAI); and cells within a group of RAN areas called tracking areas and identified by a Tracking Area Identifier (TAI).

[0115] A tracking area can be used to track the UE 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 not included in the list of TAIs associated with the UE's registration area via cell reselection, the UE can perform a registration update with the CN to allow the CN to update the UE's location and provide the UE with a new UE registration area.

[0116] RAN areas can be used to track UEs at the RAN level. For a UE in an RRC inactive 606 state, a RAN notification area can be assigned to that UE. A RAN notification area can contain one or more cell identifiers, a list of RAIs, or a list of TAIs. In the example, a base station can belong to one or more RAN notification areas. In the example, a cell can belong to one or more RAN notification areas. If a UE moves via cell reselection to a cell not included in the RAN notification area assigned to it, the UE can perform a notification area update on the RAN to update its RAN notification area.

[0117] The base station storing the RRC context for the UE, or the UE's last serving base station, may be referred to as the anchor base station. The anchor base station may maintain the RRC context for the UE at least during the period when the UE remains in the anchor base station's RAN notification area and / or during the period when the UE remains in RRC inactivity 606.

[0118] gNB, such as Figure 1B The gNB 160 can be divided into two parts: a central unit (gNB-CU) and one or more distributed units (gNB-DU). The gNB-CU can be coupled to one or more gNB-DUs using an F1 interface. The gNB-CU can contain RRC, PDCP, and SDAP. The gNB-DU can contain RLC, MAC, and PHY.

[0119] In NR, physical signals and physical channels (about Figure 5A and Figure 5BThe data discussed can be mapped onto Orthogonal Frequency Division Multiplexing (OFDM) symbols. OFDM is a multi-carrier communication scheme that transmits data via F orthogonal subcarriers (or tones). Before transmission, the data can be mapped to a series of complex symbols called source symbols (e.g., M-QAM or M-PSK symbols) and divided into F parallel symbol streams. These 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 takes F source symbols at a time (one source symbol from each of the F parallel symbol streams) and uses 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. These F time-domain samples can form a single OFDM symbol. After some processing (e.g., addition of a cyclic prefix) and upsampling, 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 an FFT block before being processed by the IFFT block. This operation produces OFDM symbols precoded by Discrete Fourier Transform (DFT) and can be used by the UE in the uplink to reduce the peak-to-average power ratio (PAPR). The inverse processing of the OFDM symbols at the receiver can be performed using the FFT block to recover the data mapped to the source symbols.

[0120] Figure 7 An example configuration of NR frames in which OFDM symbols are grouped is shown. NR frames can be identified by a System Frame Number (SFN). SFNs can repeat at a period of 1024 frames. As shown, the duration of an NR frame can be 10 milliseconds (ms) and can include 10 subframes with a duration of 1 ms. Subframes can be divided into time slots, which include, for example, 14 OFDM symbols per time slot.

[0121] The duration of a time slot can depend on the set of parameters used for the OFDM symbols in that time slot. 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). The parameter set can be defined in terms of subcarrier spacing and cyclic prefix duration. For the parameter set in NR, the subcarrier spacing can be scaled up from a baseline subcarrier spacing of 15 kHz by powers of two, and the cyclic prefix duration can be scaled down from a baseline cyclic prefix duration of 4.7 μs by powers of two. For example, NR defines parameter sets with the following combinations of subcarrier spacing / cyclic prefix duration: 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.

[0122] A time slot can have a fixed number of OFDM symbols (e.g., 14 OFDM symbols). Parameter sets with higher subcarrier spacing have shorter time slot durations and correspondingly more time slots per subframe. Figure 7 This illustrates the transmission structure of the time slot duration and per subframe time slot related to the parameter set (for ease of explanation). Figure 7 (A parameter set with a subcarrier spacing of 240 kHz is not shown in the diagram). Subframes in NR can be used as a time reference independent of the parameter set, while time slots can be used as units for scheduling uplink and downlink transmissions. To support low latency, scheduling in NR can be separated from the time slot duration and begin at any OFDM symbol, continuing to transmit as many symbols as needed. These partial time slot transmissions can be referred to as micro-time slots or sub-time slot transmissions.

[0123] Figure 8 An example configuration of time slots in the time and frequency domains of an NR carrier is shown. The time slots include resource elements (REs) and resource blocks (RBs). An RE is the smallest physical resource in NR. An RE spans one OFDM symbol in the time domain via a subcarrier in the frequency domain, such as... Figure 8 As shown in the diagram. RB spans twelve consecutive REs in the frequency domain, as... Figure 8 As shown in the diagram, the NR carrier can be limited to a width of 275 RBs or 275 × 12 = 3300 subcarriers. If this limitation is used, the NR carrier can be limited to 50 MHz, 100 MHz, 200 MHz, and 400 MHz for subcarrier spacing of 15 kHz, 30 kHz, 60 kHz, and 120 kHz, respectively, where the 400 MHz bandwidth can be set based on a bandwidth limit of 400 MHz per carrier.

[0124] Figure 8This illustrates a single set of parameters used across the entire bandwidth of an NR carrier. In other example configurations, multiple parameter sets can be supported on the same carrier.

[0125] NR can support wide carrier bandwidths (e.g., up to 400MHz for a subcarrier spacing of 120kHz). Not all UEs can receive the full carrier bandwidth (e.g., due to hardware limitations). Moreover, receiving the full carrier bandwidth can be prohibitively expensive in terms of UE power consumption. In the example, to reduce power consumption and / or for other purposes, the UE can adjust the size of its receive bandwidth based on the amount of traffic it plans to receive. This is called bandwidth adaptation.

[0126] The NR defines a Bandwidth Component (BWP) 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 consecutive Relay Buses (RBs) on a carrier. A UE can be configured (e.g., via the RRC layer) to have 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 the serving cell can be active. These one or more BWPs can be referred to as the active BWPs of the serving cell. When the serving cell is configured with a secondary uplink carrier, the serving cell can have one or more first active BWPs on the uplink carrier and one or more second active BWPs on the secondary uplink carrier.

[0127] For unpaired spectrum, if the downlink BWP index of the downlink BWP is the same as the uplink BWP index of the uplink BWP, then the downlink BWP from the set of configured downlink BWPs can link with the uplink BWP from the set of configured uplink BWPs. For unpaired spectrum, the UE can expect the center frequency of the downlink BWP to be the same as the center frequency of the uplink BWP.

[0128] For a set of configured downlink BWPs on the primary cell (PCell), the base station can configure a UE with one or more control resource sets (CORESETs) for at least one search space. A search space is a set of time-domain and frequency-domain locations where a UE can locate control information. The 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 the UE on the PCell or primary / secondary cell (PSCell) within active downlink BWPs.

[0129] For an uplink BWP in the set of configured uplink BWPs, the BS can configure one or more resource sets for the UE to transmit one or more PUCCHs. The UE can receive downlink reception (e.g., PDCCH or PDSCH) in the downlink BWP based on the configured set of parameters (e.g., subcarrier spacing and cyclic prefix duration) used for the downlink BWP. The UE can transmit uplink transmissions (e.g., PUCCH or PUSCH) in the uplink BWP based on the configured set of parameters (e.g., subcarrier spacing and cyclic prefix length of the uplink BWP).

[0130] One or more BWP indicator fields may be provided in the downlink control information (DCI). The value of the BWP indicator field can indicate which BWP in the 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 can indicate the active uplink BWP for one or more uplink transmissions.

[0131] The base station can semi-statically configure a default downlink BWP for the UE within a 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 can be the initial active downlink BWP. The UE can determine which BWP is the initial active downlink BWP based on the CORESET configuration obtained using the PBCH.

[0132] The base station can configure the BWP inactivity timer value for the UE for the PCell. The UE can start or restart the BWP inactivity timer at any appropriate time. For example, the UE can start or restart the BWP inactivity timer when: (a) the UE detects a DCI indicating an active downlink BWP other than the default downlink BWP for paired spectrum operation; or (b) the UE detects a DCI indicating an active downlink BWP or active uplink BWP other than the default downlink BWP or uplink BWP for unpaired spectrum operation. If the UE does not detect a DCI within a time interval (e.g., 1 ms or 0.5 ms), the UE can run the BWP inactivity timer toward its expiration (e.g., an increment from zero to the BWP inactivity timer value, or a decrement from the BWP inactivity timer value to zero). When the BWP inactivity timer expires, the UE can switch from the active downlink BWP to the default downlink BWP.

[0133] In the example, the base station can semi-statically configure the UE using one or more BWPs. The UE can 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 the expiration of a BWP inactivity timer (e.g., in the case that the second BWP is the default BWP).

[0134] Downlink and uplink BWP handovers can be performed independently in paired spectrum (where BWP handover refers to switching from the currently active BWP to a non-currently active BWP). In unpaired spectrum, downlink and uplink BWP handovers can be performed simultaneously. Handovers can occur between configured BWPs based on RRC signaling, DCI, the expiration of a BWP inactivity timer, and / or the initiation of random access.

[0135] Figure 9 An example of bandwidth adaptation using three configured BWPs on an NR carrier is shown. A UE configured with these three BWPs can switch from one BWP to another at a handover point. Figure 9 In the example shown, the BWPs include: BWP902 with a bandwidth of 40 MHz and a subcarrier spacing of 15 kHz; BWP904 with a bandwidth of 10 MHz and a subcarrier spacing of 15 kHz; and BWP906 with a bandwidth of 20 MHz and a subcarrier spacing of 60 kHz. BWP902 can be the initial active BWP, and BWP904 can be the default BWP. The UE can switch between BWPs at a handover point. Figure 9 In the example, the UE can switch from BWP 902 to BWP 904 at handover point 908. The handover at handover point 908 can occur for any suitable reason, such as in response to the expiration of a BWP inactivity timer (indicating a switch to the default BWP) and / or in response to receiving a DCI indicating that BWP 904 is the active BWP. The UE can switch from active BWP 904 to BWP 906 at handover point 910 in response to receiving a DCI indicating that BWP 906 is the active BWP. The UE can switch from active BWP 906 to BWP 904 at handover point 912 in response to the expiration of a BWP inactivity timer and / or in response to receiving a DCI indicating that BWP 904 is the active BWP. The UE can switch from active BWP 904 to BWP 902 at handover point 914 in response to receiving a DCI indicating that BWP 902 is the active BWP.

[0136] If a UE is configured for a secondary cell with default downlink BWP and timer values ​​from a set of configured downlink BWPs, the UE procedure for switching BWPs on the secondary cell can be the same as / similar to that on the primary cell. For example, the UE can use these values ​​on the secondary cell in the same / similar way as the UE would use the timer values ​​and default downlink BWP of the primary cell.

[0137] To provide higher data rates, carrier aggregation (CA) can be used to combine two or more carriers and transmit them simultaneously to / from the same UE. The aggregated carriers in CA can be referred to as component carriers (CCs). When using CA, there are multiple serving cells for the UE, with one serving cell per CC. A CC can have three configurations in the frequency domain.

[0138] 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 discontinuous configuration 1004, the two CCs are aggregated in the same frequency band (band A) and separated by a certain gap within the band. In the inter-band configuration 1006, the two CCs are located in frequency bands (band A and band B).

[0139] In the example, up to 32 CCs can be aggregated. Aggregated CCs can have the same or different bandwidths, subcarrier spacing, and / or duplex schemes (TDD or FDD). The serving cell for the UE using CA can have downlink CCs. For FDD, one or more uplink CCs can optionally be configured for the serving cell. For example, the ability to aggregate more downlink carriers than uplink carriers can be useful when the UE has more data traffic in the downlink than in the uplink.

[0140] When using CA, one of the aggregated cells used for the UE can be referred to as the primary cell (PCell). The PCell can be the serving cell to which the UE initially connects during RRC connection establishment, reconstruction, and / or handover. The PCell provides the UE with NAS mobility information and security input. The UE can have different PCells. In the downlink, the carrier corresponding to the PCell can be referred to as the downlink primary CC (DL PCC). In the uplink, the carrier corresponding to the PCell can be referred to as the uplink primary CC (UL PCC). Other aggregated cells used for the UE can be referred to as secondary cells (SCells). In the example, the SCell can be configured after the PCell is configured for the UE. For example, the SCell can be configured via an RRC connection reconfiguration procedure. In the downlink, the carrier corresponding to the SCell can be referred to as the downlink secondary CC (DL SCC). In the uplink, the carrier corresponding to the SCell can be referred to as the uplink secondary CC (UL SCC).

[0141] The configured SCell for the 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 transmissions on the SCell. (The remaining text appears to be incomplete and requires further context.) Figure 4B The MAC CE is used to activate and deactivate configured SCells. For example, the MAC CE can use a bitmap (e.g., one bit per SCell) to indicate which SCells for the UE (e.g., in a subset of configured SCells) are activated or deactivated. Configured SCells can be deactivated in response to the expiration of a SCell deactivation timer (e.g., one SCell deactivation timer per SCell).

[0142] Downlink control information for a cell (such as scheduling assignment and scheduling grant) can be transmitted on the cell corresponding to the assignment and grant, a process known as self-scheduling. A cell's DCI can be transmitted on another cell, a process known as cross-carrier scheduling. Uplink control information used for aggregation cells (e.g., HARQ acknowledgments and channel state feedback such as CQI, PMI, and / or RI) can be transmitted on the PCell's PUCCH. For a large number of aggregation downlink CCs, the PCell's PUCCH may become overloaded. Cells can be divided into multiple PUCCH groups.

[0143] Figure 10B This illustrates an example of how aggregated cells can be configured into one or more PUCCH groups. PUCCH group 1010 and PUCCH group 1050 can each include one or more downlink CCs. Figure 10BIn the example, 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 can be configured as PCell 1021, SCell 1022, and SCell 1023. One or more other uplink CCs can be configured as primary SCells (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) can be transmitted in the uplink of PCell 1021. Uplink control information (UCI) related to the downlink CC of PUCCH group 1050 (shown as UCI 1071, UCI 1072, and UCI 1073) can be transmitted in the uplink of PSCell 1061. In the example, if Figure 10B If the aggregated cell depicted is not divided into PUCCH group 1010 and PUCCH group 1050, a single uplink PCell will transmit UCIs associated with the downlink CC, and the PCell may become overloaded. Overload can be prevented by allocating UCI transmissions between PCell 1021 and PSCell 1061.

[0144] A physical cell ID and a cell index can be assigned to a cell that includes a downlink carrier and an optional uplink carrier. The physical cell ID or cell index can identify the cell's downlink carrier and / or uplink carrier, for example, depending on the context in which the physical cell ID is used. The physical cell ID can be determined using synchronization signals transmitted on the downlink component carriers. The cell index can be determined using RRC messages. In this disclosure, the physical cell ID can be referred to as a carrier ID, and the cell index can be referred to as a carrier index. For example, when this disclosure relates to a first physical cell ID for a first downlink carrier, this disclosure can mean that the first physical cell ID is used for a cell containing the first downlink carrier. The same / similar concepts can be applied, for example, to carrier activation. When this disclosure indicates that a first carrier is activated, this specification can mean that a cell containing the first carrier is activated.

[0145] In CA, the multi-carrier nature of the PHY can be exposed to the MAC. In the example, the HARQ entity can operate on the serving cell. Transport blocks can be generated based on the assignment / grant of each serving cell. Transport blocks and their potential HARQ retransmissions can be mapped to the serving cell.

[0146] In the downlink, the base station can transmit one or more reference signals (RS) (e.g., unicast, multicast, and / or broadcast) to the UE (e.g., PSS, SSS, CSI-RS, DMRS, and / or PT-RS, such as...). Figure 5A (As shown in the diagram). In the uplink, the UE can transmit one or more RSs to the base station (e.g., DMRS, PT-RS, and / or SRS, such as...). Figure 5B (As shown in the diagram). PSS and SSS can be transmitted by the base station and used by the UE to synchronize the UE with the base station. PSS and SSS can be provided in a synchronization signal (SS) / physical broadcast channel (PBCH) block that includes PSS, SSS, and PBCH. The base station can periodically transmit bursts of SS / PBCH blocks.

[0147] Figure 11A An example of the structure and location of SS / PBCH blocks is shown. A burst of SS / PBCH blocks can include one or more SS / PBCH blocks (e.g., 4 SS / PBCH blocks, such as...). Figure 11A (As shown in the diagram). Bursts can be transmitted periodically (e.g., every 2 frames or 20 ms). Bursts can be limited to half-frames (e.g., the first half-frame lasting 5 ms). It should be understood that... Figure 11A This is an example, and these parameters (the number of SS / PBCH blocks per burst, the periodicity of the burst, the burst location within a frame) can be configured based on, for example, the carrier frequency of the cell in which the SS / PBCH blocks are transmitted; the cell's parameter set or subcarrier spacing; configuration performed by the network (e.g., using RRC signaling); or any other suitable factors. In this example, the UE can 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.

[0148] SS / PBCH blocks can span one or more OFDM symbols in the time domain (e.g., 4 OFDM symbols, such as...). Figure 11A As shown in the example, and can span one or more subcarriers in the frequency domain (e.g., 240 consecutive subcarriers). PSS, SSS, and PBCH can have a common center frequency. PSS can be transmitted first and can span, for example, 1 OFDM symbol and 127 subcarriers. SSS can be transmitted after PSS (e.g., after two symbols) and can span 1 OFDM symbol and 127 subcarriers. PBCH can be transmitted after PSS (e.g., spanning the next 3 OFDM symbols) and can span 240 subcarriers.

[0149] The UE may not know the location of the SS / PBCH block in the time and frequency domains (e.g., when the UE is searching for a cell). To find and select a cell, the UE can monitor the carrier of the PSS. For example, the UE can monitor the frequency location within the carrier. If the PSS is not found after a certain duration (e.g., 20 ms), the UE can search for the PSS at different frequency locations within the carrier, as indicated by the synchronization grating. If the PSS is found at a certain location in the time and frequency domains, the UE can determine the locations of the SSS and PBCH based on the known structure of the SS / PBCH block, respectively. The SS / PBCH block can be a cell-defined SS block (CD-SSB). In the example, the primary cell can be associated with the CD-SSB. The CD-SSB can be located on the synchronization grating. In the example, cell selection / search and / or reselection can be based on the CD-SSB.

[0150] The UE can use the SS / PBCH block 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 sequences 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 mode in which the SS / PBCH block in the transmission mode is at a known distance from the frame boundary.

[0151] The PBCH can use QPSK modulation and forward error correction (FEC). FEC can use polarity coding. One or more symbols spanned by the PBCH can carry one or more DMRS for PBCH demodulation. The PBCH can include an indication of the cell's current system frame number (SFN) and / or an SS / PBCH block timing index. These parameters can help the UE synchronize time with the base station. The PBCH can include a Master Information Block (MIB) to provide one or more parameters to the UE. The MIB can be used by the UE to locate the Residual Minimum System Information (RMSI) associated with the cell. The RMSI can include System Information Block Type 1 (SIB1). SIB1 can contain information required for the UE to access the cell. The UE can use one or more parameters of the MIB to monitor the PDCCH that can be used to schedule the PDSCH. The PDSCH can include SIB1. SIB1 can be decoded using the parameters provided in the MIB. The PBCH can indicate that SIB1 does not exist. Based on the PBCH indicating that SIB1 does not exist, the UE can point to a frequency. The UE can search for SS / PBCH blocks at the frequency pointed to by the UE.

[0152] The UE may assume that one or more SS / PBCH blocks transmitted using 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.

[0153] SS / PBCH blocks (e.g., those within a half-frame) can be transmitted in spatial directions (e.g., using different beams across the coverage area of ​​the cell). In the example, the first SS / PBCH block can be transmitted in the first spatial direction using the first beam, and the second SS / PBCH block can be transmitted in the second spatial direction using the second beam.

[0154] In the example, within the carrier's frequency range, the base station can transmit multiple SS / PBCH blocks. In the example, the first PCI of the first SS / PBCH block among the multiple SS / PBCH blocks can be different from the second PCI of the second SS / PBCH block among the multiple SS / PBCH blocks. The PCIs of SS / PBCH blocks transmitted at different frequency locations can be different or the same.

[0155] CSI-RS can be transmitted by the base station and used by the UE to acquire Channel State Information (CSI). The base station can utilize one or more CSI-RS to configure the UE for channel estimation or any other suitable purpose. The base station can utilize one or more of the same / similar CSI-RS to configure the UE. The UE can measure the one or more CSI-RS. The UE can estimate the downlink channel state and / or generate a CSI report based on the measurements of the one or more downlink CSI-RS. The UE can provide the CSI report to the base station. The base station can use the feedback provided by the UE (e.g., the estimated downlink channel state) to perform link adaptation.

[0156] The base station can semi-statically configure the UE using one or more CSI-RS resource sets. CSI-RS resources can be associated with location and periodicity in the time and frequency domains. The base station can selectively activate and / or deactivate CSI-RS resources. The base station can instruct the UE that CSI-RS resources in the CSI-RS resource set are activated and / or deactivated.

[0157] The base station can configure the UE to report CSI measurements. 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 multiple CSI report timings and / or periods. For aperiodic CSI reporting, the base station can request CSI reports. For example, the base station can command the UE to measure configured CSI-RS resources and provide CSI reports related to the measurements. For semi-persistent CSI reporting, the base station can configure the UE to transmit periodically and selectively activate or deactivate periodic reports. The base station can configure the UE using CSI-RS resource sets and CSI reports using RRC signaling.

[0158] The CSI-RS configuration may include one or more parameters indicating, for example, up to 32 antenna ports. The UE can be configured to use the same OFDM symbols for both the downlink CSI-RS and the 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 block (PRB) configured for the CORESET. The UE can also be configured to use the same OFDM symbols for both the downlink CSI-RS and the SS / PBCH block 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 PRB configured for the SS / PBCH block.

[0159] Downlink DMRS can be transmitted by the base station and used by the UE for channel estimation. For example, 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 modes for data demodulation. At least one downlink DMRS configuration can support a frontload DMRS mode. 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 using the number (e.g., maximum number) of frontload DMRS symbols used for PDSCH. A DMRS configuration can support one or more DMRS ports. For example, for single-user MIMO, a DMRS configuration can support up to eight orthogonal downlink DMRS ports per UE. For multi-user MIMO, a 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 DMRS locations, DMRS types, and / or scrambling sequences can be the same or different. The base station can use the same precoding matrix to transmit downlink DMRS and the corresponding PDSCH. The UE can use one or more downlink DMRS to perform consistent demodulation / channel estimation of the PDSCH.

[0160] In the example, the transmitter (e.g., a base station) can use a precoder matrix for a portion of the transmission bandwidth. For example, the transmitter can use a first precoder matrix for a first bandwidth and a second precoder matrix for a second bandwidth. The first and second precoder matrices can differ based on the first and second bandwidths being different. The UE can assume that the same precoder matrix is ​​used across the set of PRBs. The set of PRBs can be represented as a Precode Resource Block Group (PRG).

[0161] A PDSCH can contain one or more layers. The UE can assume that at least one symbol with DMRS exists on one or more layers of the PDSCH. A higher layer can configure up to three DMRS for the PDSCH.

[0162] Downlink PT-RS can be transmitted by the base station and used by the UE for phase noise compensation. The presence of downlink PT-RS can depend on RRC configuration. The presence and / or type of downlink PT-RS can be configured UE-specifically using a combination of RRC signaling and / or association with one or more parameters (e.g., modulation and coding scheme (MCS)) indicated by the DCI for other purposes. When configured, the dynamic presence of downlink PT-RS can be associated with one or more DCI parameters containing at least one MCS. NR networks can support multiple PT-RS densities defined in the time and / or frequency domains. When present, the frequency domain density can be associated with at least one configuration of the scheduled bandwidth. The UE can employ the same precoding for both 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. Downlink PT-RS can be restricted to the UE's scheduled time / frequency duration. Downlink PT-RS can be transmitted on symbols to facilitate phase tracking at the receiver.

[0163] The UE can transmit uplink DMRS to the base station for channel estimation. For example, the base station can use uplink DMRS to perform consistent demodulation of one or more uplink physical channels. For example, the UE can transmit uplink DMRS with PUSCH and / or PUCCH. Uplink DMRS can span a frequency range similar to the frequency range associated with the corresponding physical channel. The base station can configure the UE using one or more uplink DMRS configurations. At least one DMRS configuration can support a frontload DMRS mode. Frontload DMRS can be mapped on one or more OFDM symbols (e.g., one or two adjacent OFDM symbols). One or more uplink DMRS can be configured to be transmitted at one or more symbols of PUSCH and / or PUCCH. The base station can semi-statically configure the UE with the number (e.g., maximum number) of frontload DMRS symbols for PUSCH and / or PUCCH, and the UE can use the frontload DMRS symbols to schedule single-symbol DMRS and / or dual-symbol DMRS. NR networks can support (e.g., for Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM)) a common DMRS structure for both downlink and uplink, where the DMRS location, DMRS type, and / or scrambling sequence of the DMRS can be the same or different.

[0164] A PUSCH can contain one or more layers, and a UE can transmit at least one symbol with DMRS present on one or more layers of the PUSCH. In the example, a higher layer can configure up to three DMRS for the PUSCH.

[0165] Depending on the UE's RRC configuration, 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 the UE 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 that include at least one 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 both 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 limited to the UE's scheduled time / frequency duration.

[0166] The UE can transmit 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 allows the base station to estimate the uplink channel state at one or more frequencies. The scheduler at the base station can use the estimated uplink channel state to assign one or more resource blocks to uplink PUSCH transmissions from the UE. The base station can semi-statically configure the UE using one or more SRS resource sets. For each SRS resource set, the base station can configure the UE using one or more SRS resources. SRS resource set suitability can be configured by higher-layer (e.g., RRC) parameters. For example, when higher-layer parameters indicate beam management, SRS resources in one or more SRS resource sets (e.g., having the same / similar time-domain behavior, periodic, aperiodic, etc.) can be transmitted at certain times (e.g., simultaneously). The UE can transmit one or more SRS resources from the SRS resource set. The NR network can support aperiodic, periodic, and / or semi-persistent SRS transmissions. The UE can 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 the 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 the example, when PUSCH and SRS are transmitted in the same time slot, the UE can be configured to transmit SRS after the transmission of PUSCH and the corresponding uplink DMRS.

[0167] The base station can semi-statically configure the UE using one or more SRS configuration parameters indicating at least one of the following: SRS resource configuration identifier; number of SRS ports; temporal behavior of SRS resource configuration (e.g., indication of periodic, semi-persistent, or aperiodic SRS); time slot, micro-time slot, and / or subframe level periodicity; offset of periodic and / or aperiodic SRS resources; number of OFDM symbols in SRS resources; starting OFDM symbol of SRS resources; SRS bandwidth; frequency hopping bandwidth; cyclic shift; and / or SRS sequence ID.

[0168] Antenna ports are defined such that a symbol on an antenna port, transmitted via its channel, can be inferred from another symbol on the same antenna port, transmitted via its channel. If a first symbol and a second symbol are transmitted on the same antenna port, the receiver can infer the channel used to transmit the second symbol on the antenna port (e.g., fading gain, multipath delay, etc.) from the channel used to transmit the first symbol on the antenna port. A first antenna port and a second antenna port can be referred to as quasi-co-located (QCLed) if one or more large-scale properties can be inferred from the channel through which the second symbol on the second antenna port is transmitted, and the channel through which the first symbol on the first antenna port is transmitted. 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 reception (Rx) parameters.

[0169] 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 and generate a beam measurement report based on downlink reference signals (e.g., Channel State Information Reference Signal (CSI-RS)). After establishing an RRC connection with the base station, the UE can execute the downlink beam measurement procedure.

[0170] Figure 11B An example of a Channel State Information Reference Signal (CSI-RS) mapped in the time and frequency domains is shown. Figure 11BThe square shown can represent a resource block (RB) within the cell's bandwidth. The base station can transmit one or more RRC messages containing CSI-RS resource configuration parameters indicating one or more CSI-RS. One or more of the following parameters can be configured for 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 subframes), CSI-RS subframe configuration (e.g., subframe position, offset, and periodicity in radio frames), CSI-RS power parameters, CSI-RS sequence parameters, Code Division Multiplexing (CDM) type parameters, frequency density, transport 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.

[0171] Figure 11B The three beams shown can be configured for use in a UE-specific configuration. Figure 11B The diagram shows three beams (beam #1, beam #2, and beam #3), with the possibility of configuring more or fewer beams. CSI-RS1101 can be assigned to beam #1, which can be transmitted on one or more subcarriers in the RB of the first symbol. CSI-RS1102 can be assigned to beam #2, which can be transmitted on one or more subcarriers in the RB of the second symbol. CSI-RS1103 can be assigned to beam #3, which can be transmitted on one or more subcarriers in the RB of the third symbol. By using frequency division multiplexing (FDM), the base station can use other subcarriers in the same RB (e.g., those 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), the beam for a UE can be configured such that the beam for the UE uses symbols from beams of other UEs.

[0172] CSI-RS, such as Figure 11BThose shown (e.g., CSI-RS 1101, 1102, 1103) can be transmitted by the base station and used by the UE for one or more measurements. For example, the UE can measure the Reference Signal Received Power (RSRP) configured with CSI-RS resources. The base station can configure the UE using a reporting configuration, and the UE can report RSRP measurements 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 downlink transmissions 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 mapping capability. If the UE has beam mapping capability, the UE can determine the spatial domain filter for the transmit (Tx) beam based on the spatial domain filter corresponding to the Rx beam. If the UE does not have beam correspondence capability, the UE can perform an uplink beam selection procedure to determine the spatial domain filter for the Tx beam. The UE can perform the uplink beam selection procedure based on one or more Sounding Reference Signal (SRS) resources configured for the UE by the base station. The base station can select and indicate the UE's uplink beam based on measurements of one or more SRS resources transmitted by the UE.

[0173] In the beam management procedure, the UE can assess (e.g., measure) the channel quality of one or more beampup links, beampup links containing transmit beams transmitted by the base station, and receive beams received by the UE. Based on the assessment, the UE can transmit a beam measurement report indicating one or more beampup quality parameters, which include, 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).

[0174] Figure 12AExamples of three downlink beam management procedures are shown: P1, P2, and P3. Procedure P1 can enable UE measurement of the transmit (Tx) beams for a Transport Receive Point (TRP) (or multiple TRPs), for example, to support the selection of one or more base station Tx beams and / or UE Rx beams (shown as ellipses in the top and bottom rows of P1, respectively). Beamforming at the TRP can include a Tx beam scan for the beam set (shown as an ellipse rotating counterclockwise in the top rows of P1 and P2, indicated by dashed arrows). Beamforming at the UE can include an Rx beam scan for the beam set (shown as an ellipse rotating clockwise in the bottom rows of P1 and P3, indicated by dashed arrows). Procedure P2 can be used to enable UE measurement of the Tx beams for a TRP (shown as an ellipse rotating counterclockwise in the top row of P2, indicated by dashed arrows). The UE and / or base station may perform procedure P2 using a smaller beam set than that used in procedure P1, or using a narrower beam than that used in procedure P1. This may be referred to as beam refinement. The UE may perform procedure P3 for Rx beam determination by using the same Tx beam at the base station and sweeping the Rx beam at the UE.

[0175] Figure 12B Examples of three uplink beam management procedures are shown: U1, U2, and U3. Procedure U1 can be used to enable the base station to perform measurements on the Tx beam of the UE, for example, to support the selection of one or more UE Tx beams and / or base station Rx beams (shown as ellipses in the top and bottom rows of U1, respectively). Beamforming at the UE may include, for example, a Tx beam scan from a set of beams (shown as an ellipse rotating clockwise in the bottom rows of U1 and U3, indicated by dashed arrows). Beamforming at the base station may include, for example, an Rx beam scan from a set of beams (shown as an ellipse rotating counterclockwise in the top rows of U1 and U2, indicated by dashed arrows). 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 may use a smaller beam set than that used in procedure P1, or use a narrower beam than that used in procedure P1, to perform procedure U2. This can be called beam refinement. The UE can execute procedure U3 to adjust its Tx beam when the base station is using a fixed Rx beam.

[0176] The UE can initiate a beam failure recovery (BFR) procedure based on the detection of a beam failure. The UE can initiate a BFR request (e.g., preamble, UCI, SR, MAC CE, etc.) based on the BFR procedure. The UE can detect a beam failure based on the determination that the quality of the beam pair link in the associated control channel is unsatisfactory (e.g., an error rate higher than the error rate threshold, received signal power lower than the received signal power threshold, timer expiration, etc.).

[0177] The UE can use one or more reference signals (RS) to measure the quality of the beamp-link, which include one or more SS / PBCH blocks, one or more CSI-RS resources, and / or one or more demodulation reference signals (DMRS). The quality of the beamp-link can be based on one or more of the following: block error rate (BLER), RSRP value, signal-to-interference-plus-noise ratio (SINR) value, reference signal reception quality (RSRQ) value, and / or CSI value measured on the RS resources. The base station can indicate one or more DM-RS quasi-co-located (QCLed) RS resources and channels (e.g., control channels, shared data channels, etc.). The one or more DMRS of the RS resources and channels can be QCLed when the channel characteristics (e.g., Doppler shift, Doppler spread, average delay, delay spread, spatial Rx parameter, fading, etc.) from the transmission to the UE via the RS resources are similar to or the same as the channel characteristics from the transmission to the UE via the channels.

[0178] The network (e.g., gNB and / or the network's ng-eNB) and / or the UE can initiate a random access procedure. A UE in the RRC_IDLE state and / or RRC_INACTIVE state can initiate a random access procedure to request connection settings to the network. A UE can initiate a random access procedure from the RRC_CONNECTED state. A UE can initiate a random access procedure to request uplink resources (e.g., for uplink transmission of SR when no PUCCH resources are available) and / or to acquire uplink timing (e.g., when the uplink synchronization state is not synchronized). A UE can initiate a random access procedure to request one or more System Information Blocks (SIBs) (e.g., other system information such as SIB2, SIB3, etc.). A UE can initiate a random access procedure for beam failure recovery requests. The network can initiate random access procedures for handover and / or for establishing time alignment for SCell addition.

[0179] Figure 13A A four-step contention-based random access procedure is illustrated. Before initiating the procedure, the base station may transmit configuration message 1310 to the UE. Figure 13AThe procedure shown involves 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).

[0180] 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 RRC_INACTIVE state). The UE may determine the time-frequency resources and / or uplink transmission power for transmitting Msg 11311 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 receive timing and downlink channel for receiving Msg 2 1312 and Msg 4 1314.

[0181] The one or more RACH parameters provided in configuration message 1310 may indicate one or more physical RACH (PRACH) timings available for transmitting Msg 11311. These one or more PRACH timings may be predefined. The one or more RACH parameters may indicate one or more available sets of one or more PRACH timings (e.g., prach-ConfigIndex). The one or more RACH parameters may indicate an association between (a) one or more PRACH timings 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 PRACH timings and / or the number of preambles mapped to SS / PBCH blocks.

[0182] The one or more RACH parameters provided in configuration message 1310 can 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 can indicate a reference power for preamble transmission (e.g., the received target power and / or the initial power of the preamble transmission). One or more power offsets indicated by the one or more RACH parameters may exist. For example, the one or more RACH parameters can indicate: power ramp step size; power offset between SSB and CSI-RS; power offset between transmissions of Msg 1 1311 and Msg 3 1313; and / or power offset values ​​between preamble groups. The one or more RACH parameters can indicate one or more thresholds upon which the UE can determine at least one reference signal (e.g., SSB and / or CSI-RS) and / or uplink carrier (e.g., normal uplink (NUL) carrier and / or supplementary uplink (SUL) carrier).

[0183] Msg 1 1311 may include one or more preamble transmissions (e.g., preamble transmission and one or more preamble retransmissions). The RRC message can be used to configure one or more preamble groups (e.g., group A and / or group B). A preamble group may contain one or more preambles. The UE may determine the preamble group based on path loss measurements and / or the magnitude 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 with an RSRP higher 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 the RRC message, the UE can select at least one preamble associated with the one or more reference signals and / or the selected preamble group.

[0184] The UE can determine the preamble based on one or more RACH parameters provided in configuration message 1310. For example, the UE can determine the preamble based on path loss measurement, RSRP measurement, and / or the size of Msg 3 1313. As another example, the one or more RACH parameters can indicate: the preamble format; the 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 can 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 can determine the preamble included in Msg 1 1311 based on the association. Msg 1 1311 can be transmitted to the base station via one or more PRACH timings. The UE can use one or more reference signals (e.g., SSB and / or CSI-RS) for selecting the preamble and for determining the PRACH timing. One or more RACH parameters (e.g., ra-ssb-OccasionMaskIndex and / or ra-OccasionList) can indicate the association between the PRACH timing and the one or more reference signals.

[0185] If no response is received after the preamble transmission, the UE may perform a preamble retransmission. The UE may increase the uplink transmission power used for the preamble retransmission. The UE may select the initial preamble transmission power based on path loss measurements and / or the target received preamble power configured by the network. The UE may determine the preamble to be retransmitted 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 step size used for the preamble retransmission. The ramp step size may be the amount by which the uplink transmission power used for the retransmission is incrementally increased. If the UE determines that the same reference signal (e.g., SSB and / or CSI-RS) is used as in 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 configured by one or more RACH parameters (e.g., preambleTransMax), the UE can determine that the random access procedure has not been successfully completed.

[0186] The 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 comparison command that the UE can use to adjust the UE's transmission timing, a scheduling permission 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., ra-ResponseWindow) to monitor the PDCCH for Msg 2 1312. The UE can determine when to initiate a time window based on the PRACH timing in which it transmits the preamble. For example, the UE can initiate a time window of one or more symbols after the last symbol of the preamble (e.g., at the first PDCCH timing starting from the end of the preamble transmission). The one or more symbols can be determined based on a set of parameters. The PDCCH can be in a common search space configured by RRC messages (e.g., a Type 1-PDCCH common search space). The UE can identify the RAR based on a Radio Network Temporary Identifier (RNTI). The RNTI can be used depending on one or more events that initiate a random access procedure. The UE can use a Random Access RNTI (RA-RNTI). The RA-RNTI can be associated with the PRACH timing in which the UE transmits the preamble. For example, the UE can determine the RA-RNTI based on: the OFDM symbol index; the time slot index; the frequency domain index; and / or the UL carrier indicator of the PRACH timing. Examples of RA-RNTIs include: RA-RNTI= 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 ×ul_carrier_id Where s_id can be the index of the first OFDM symbol of the PRACH timing (e.g., 0 ≤ s_id < 14), t_id can be the index of the first slot of the PRACH timing in the system frame (e.g., 0 ≤ t_id < 80), f_id can be the index of the PRACH timing in the frequency domain (e.g., 0 ≤ f_id < 8), and ul_carrier_id can be the UL carrier used for preamble transmission (e.g., 0 for NUL carriers and 1 for SUL carriers).

[0187] The UE may transmit Msg 3 1313 in response to successful reception of Msg 2 1312 (e.g., using the resource identified in Msg 2 1312). Msg 3 1313 can be used for, for example... Figure 13A The diagram illustrates contention resolution in a contention-based random access procedure. In some scenarios, multiple UEs may transmit the same preamble to a base station, and the base station may provide a RAR corresponding to each UE. A conflict may occur if the multiple UEs interpret the RAR as corresponding to themselves. Contention resolution (e.g., using Msg 3 1313 and Msg 4 1314) can be used to increase the likelihood that a UE will 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., the TC-RNTI included in Msg 2 1312 if a C-RNTI is assigned, and / or any other suitable identifier).

[0188] Msg 4 1314 can be received after or in response to the transmission of Msg 3 1313. If Msg 3 1313 includes a C-RNTI, 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 Msg 3 1313 includes a TC-RNTI (e.g., if the UE is in an RRC_IDLE state or not otherwise connected to the base station), Msg 4 1314 will be received using the DL-SCH associated with the TC-RNTI. If the MAC PDU is successfully decoded and the MAC PDU contains a UE contention resolution identity MAC CE that matches (e.g., is transmitted) the CCCH SDU sent in Msg 3 1313, the UE can determine that contention resolution was successful and / or the UE can determine that the random access procedure was successfully completed.

[0189] The UE can be configured with Supplemental Uplink (SUL) carriers and Normal Uplink (NUL) carriers. Initial access (e.g., random access procedure) can be supported on the uplink carriers. For example, the base station can configure two separate RACH configurations for the UE: one for the SUL carrier and another for the NUL carrier. To enable random access in a cell configured with an SUL carrier, the network can indicate which carrier (NUL or SUL) to use. For example, the UE can determine the SUL carrier if the measured quality of one or more reference signals is below a broadcast threshold. Uplink transmissions during the random access procedure (e.g., Msg 1 1311 and / or Msg 3 1313) can be preserved on the selected carrier. In one or more cases, the UE can switch uplink carriers during the random access procedure (e.g., between Msg 1 1311 and Msg 3 1313). For example, the UE can determine and / or switch uplink carriers for Msg 1 1311 and / or Msg 3 1313 based on channel clarity assessment (e.g., listen before speaking).

[0190] Figure 13B This illustrates a two-step contention-free random access procedure. (Compared to...) Figure 13A Similar to the four-step contention-based random access procedure shown, the base station can transmit configuration message 1320 to the UE before the procedure is initiated. Configuration message 1320 may be similar to configuration message 1310 in some respects. Figure 13B The program shown involves the transmission of two messages: Msg 1 1321 and Msg 2 1322. Msg 1 1321 and Msg 2 1322 can be similar in some respects to... Figure 13A The Msg 1 1311 and Msg2 1312 are shown. (As from...) Figure 13A and Figure 13B It will be understood that a contention-free random access procedure may not include messages such as Msg 3 1313 and / or Msg 4 1314.

[0191] It can be initiated for beam failure recovery, other SI requests, SCell addition and / or switching. Figure 13B The contention-free random access procedure is illustrated. For example, the base station may indicate or assign a preamble to the UE for Msg 1 1321. The UE may receive the preamble indication (e.g., ra-PreambleIndex) from the base station via PDCCH and / or RRC.

[0192] After transmitting the preamble, the UE can initiate a time window (e.g., ra-ResponseWindow) to monitor the PDCCH of the RAR. In the event of a beam failure recovery request, the base station can configure the UE with a separate time window and / or a separate PDCCH within the search space indicated by the RRC message (e.g., recoverySearchSpaceId). The UE can monitor PDCCH transmissions addressed to the Cell RNTI (C-RNTI) in the search space. Figure 13B In the contention-free random access procedure shown, the UE can determine that the random access procedure was 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 addresses to the C-RNTI, the UE can determine that the random access procedure was successfully completed. For example, if the UE receives a RAR containing a preamble identifier corresponding to the preamble transmitted by the UE and / or the RAR contains a MAC sub-PDU with a preamble identifier, the UE can determine that the random access procedure was successfully completed. The UE can determine this response as an indication of confirmation of the SI request.

[0193] Figure 13C Another two-step random access procedure is shown. (Compared to...) Figure 13A and Figure 13B Similar to the random access procedure shown, the base station can transmit configuration message 1330 to the UE before the procedure is initiated. Configuration message 1330 may be similar in some respects to configuration message 1310 and / or configuration message 1320. Figure 13C The program shown involves the transmission of two messages: Msg A1331 and Msg B1332.

[0194] Msg A 1331 can be transmitted by the UE in an uplink transmission. Msg A 1331 may contain one or more transmissions of preamble 1341 and / or one or more transmissions of transport block 1342. Transport block 1342 may contain... Figure 13A The content shown in Msg 3 1313 is similar to and / or equivalent to that of Msg 3 1313. Transport block 1342 may contain UCIs (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 contain content similar to... Figure 13A and Figure 13B The Msg 2 1312 shown (e.g., RAR) and / or Figure 13A The content shown is similar to and / or equivalent to Msg 41314.

[0195] UE can initiate [activities] on licensed spectrum and / or unlicensed spectrum. Figure 13C The two-step random access procedure is used in the UE. 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 be: the radio access technology being used (e.g., LTE, NR, etc.); whether the UE has a valid TA; cell size; the UE's RRC status; the type of spectrum (e.g., licensed vs. unlicensed); and / or any other suitable factors.

[0196] The UE can 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 configuration message 1330. The RACH parameters can 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) for the transmission of the preamble 1341 and the time-frequency resources (e.g., PUSCH) for the transmission of the transport block 1342 can be multiplexed using FDM, TDM, and / or CDM. The RACH parameters enable the UE to determine the receive timing and downlink channel for monitoring and / or receiving Msg B 1332.

[0197] Transport block 1342 may contain data (e.g., delay-sensitive data), a UE identifier, security information, and / or device information (e.g., International Mobile Subscriber Identity (IMSI)). The base station may transmit Msg B 1332 as a response to Msg A 1331. Msg B 1332 may contain at least one of the following: a preamble identifier; a timing advanced command; a power control command; uplink grant (e.g., radio resource assignment and / or MCS); a UE identifier for contention resolution; and / or an RNTI (e.g., a C-RNTI or a TC-RNTI). The UE can determine that the two-step random access procedure was 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).

[0198] The UE and the base station can 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.

[0199] Downlink control signaling may include: downlink scheduling assignment; uplink scheduling permission indicating uplink radio resources and / or transmission format; time slot format information; preemption indication; power control command; and / or any other suitable signaling. The UE may receive downlink control signaling in the payload transmitted by the base station on the 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-shared PDCCH (GC-PDCCH) common to the UE group.

[0200] A base station can attach one or more Cyclic Redundancy Check (CRC) parity bits to the DCI to aid in the detection of transmission errors. When the DCI is intended for use with a UE (or a group of UEs), the base station can scramble the CRC parity bits with the UE's identifier (or the UE group's identifier). Scrambling the CRC parity bits with the identifier can involve a modulo-2 addition (or XOR operation) of the identifier value and the CRC parity bits. The identifier can contain a 16-bit value of the Radio Network Temporary Identifier (RNTI).

[0201] DCIs can be used for various 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 using the Paging RNTI (P-RNTI) can indicate paging information and / or system information change notifications. The P-RNTI can be predefined as "FFFE" in hexadecimal. A DCI with CRC parity bits scrambled using the System Information RNTI (SI-RNTI) can indicate broadcast transmission of system information. The SI-RNTI can be predefined as "FFFF" in hexadecimal. A DCI with CRC parity bits scrambled using the Random Access RNTI (RA-RNTI) can indicate a Random Access Response (RAR). A DCI with CRC parity bits scrambled using the Cell RNTI (C-RNTI) can indicate dynamically scheduled unicast transmissions and / or triggering of PDCCH ordered random access. A DCI with CRC parity bits scrambled using the Temporary Cell RNTI (TC-RNTI) can indicate contention resolution (e.g., similar to...). Figure 13AThe Msg 3 shown is Msg 3 of 1313. Other RNTIs configured by the base station for the UE may include: the configured scheduling RNTI (CS-RNTI), transmission power control PUCCH RNTI (TPC-PUCCH-RNTI), transmission power control PUSCH RNTI (TPC-PUSCH-RNTI), transmission power control SRS RNTI (TPC-SRS-RNTI), interrupt 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.

[0202] 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 can be used for PUSCH scheduling in a cell. DCI format 0_0 can be a fallback DCI format (e.g., with a compact DCI payload). DCI format 0_1 ​​can be used for PUSCH scheduling in a cell (e.g., with a larger DCI payload than DCI format 0_0). DCI format 1_0 can be used for PDSCH scheduling in a cell. DCI format 1_0 can be a fallback DCI format (e.g., with a compact DCI payload). DCI format 1_1 can be used for PDSCH scheduling in a cell (e.g., with a larger DCI payload than DCI format 1_0). DCI format 2_0 can be used to provide slot format indication to UE groups. DCI format 2_1 can be used to notify UE groups of physical resource blocks and / or OFDM symbols, where UEs may assume that transmission to UEs is not expected. DCI format 2_2 can be used to transmit Transmission Power Control (TPC) commands for PUCCH or PUSCH. DCI format 2_3 can be used to transmit TPC command groups for SRS transmission by one or more UEs. New DCI formats for new features can be defined in future versions. DCI formats can have different DCI sizes, or they can share the same DCI size.

[0203] After scrambling the DCI with RNTI, the base station can process the DCI using channel coding (e.g., polarity coding), rate matching, scrambling, and / or QPSK modulation. The base station can map the coded and modulated DCI onto resource elements used for and / or configured for the PDCCH. Based on the DCI payload size and / or the base station's coverage area, 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. A CCE can contain a number of resource element groups (REGs) (e.g., 6). A REG can contain resource blocks in OFDM symbols. The mapping of the coded and modulated DCI onto resource elements can be based on a mapping between CCEs and REGs (e.g., CCE-to-REG mapping).

[0204] Figure 14A An example of a CORESET configuration for the bandwidth portion is shown. A base station can transmit DCI via PDCCH on one or more control resource sets (CORESETs). A CORESET can contain time-frequency resources in which the UE attempts to decode the DCI using one or more search spaces. The base station can configure the CORESET in the time-frequency domain. Figure 14A In the example, the first CORESET 1401 and the second CORESET 1402 appear at the first symbol of the time slot. The first CORESET 1401 overlaps with the second CORESET 1402 in the frequency domain. The third CORESET 1403 appears at the third symbol of the time slot. The fourth CORESET 1404 appears at the seventh symbol of the time slot. CORESETs can have different numbers of resource blocks in the frequency domain.

[0205] Figure 14B An example of CCE-to-REG mapping for DCI transmission is shown in CORESET and PDCCH processing. CCE-to-REG mapping can be interleaved (e.g., for providing frequency diversity) or non-interleaved (e.g., for facilitating interference coordination and / or frequency-selective transmission in the control channel). The base station can perform different or the same CCE-to-REG mappings for different CORESETs. A CORESET can be associated with CCE-to-REG mapping via RRC configuration. A CORESET can be configured with antenna port quasi-co-location (QCL) parameters. Antenna port QCL parameters can indicate the QCL information for the demodulation reference signal (DMRS) used for PDCCH reception in the CORESET.

[0206] The base station can transmit an RRC message to the UE containing configuration parameters for one or more CORESETs and one or more search space sets. The configuration parameters can indicate the association between the search space set and the CORESET. The search space set can contain a set of PDCCH candidates formed by CCEs at a given aggregation level. The configuration parameters can indicate: the number of PDCCH candidates to be monitored at each aggregation level; the PDCCH monitoring period and PDCCH monitoring type; 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 can be predefined and known to the UE. The set of CCEs in the UE-specific search space set can be configured based on the UE's identifier (e.g., C-RNTI).

[0207] like Figure 14B As shown, the UE can determine the time-frequency resources of the CORESET based on RRC messages. The UE can determine the CCE-to-REG mapping of the CORESET (e.g., interleaved or non-interleaved and / or mapping parameters) based on the CORESET's configuration parameters. The UE can determine the number of search space sets configured on the CORESET (e.g., up to 10) based on RRC messages. The UE can monitor a set of PDCCH candidates based on the configuration parameters of the search space sets. The UE can 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 according to the monitored DCI format. Monitoring may include decoding the DCI content of one or more PDCCH candidates, which have possible (or configured) PDCCH locations, 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 can determine that the DCI is valid for the UE in response to a CRC check (e.g., scrambling bits of the CRC parity bit of the DCI that match the RNTI value). The UE can process the information contained in the DCI (e.g., scheduling assignment, uplink grant, power control, slot format indication, downlink preemption, etc.).

[0208] The UE can transmit uplink control signaling (e.g., uplink control information (UCI)) to the base station. Uplink control signaling transmission may include a Hybrid Automatic Repeat Request (HARQ) acknowledgment for a received DL-SCH transport block. The UE may transmit the HARQ acknowledgment after receiving the DL-SCH transport block. 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 can determine transmission format parameters (e.g., including multiple antennas and beamforming schemes) for downlink transmission. Uplink control signaling may include a scheduling request (SR). The UE may transmit an SR indicating that uplink data is available for transmission to the base station. The UE can transmit UCI (e.g., HARQ acknowledgment, CSI report, SR, etc.) via the Physical Uplink Control Channel (PUCCH) or the Physical Uplink Shared Channel (PUSCH). The UE can transmit uplink control signaling via PUCCH using one of several PUCCH formats.

[0209] Five PUCCH formats can exist, and the UE can determine the PUCCH format based on the size of the UCI (e.g., the number of uplink symbols transmitted in the UCI and the number of UCI bits). PUCCH format 0 can have a length of one or two OFDM symbols and can include two or fewer bits. If more than one or two symbols are transmitted and the number of HARQ-ACK information bits (HARQ-ACK / SR bits) with positive or negative SR is one or two, the UE can use PUCCH format 0 to transmit the UCI in the PUCCH resource. PUCCH format 1 can occupy between four and fourteen OFDM symbols and can 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 can use PUCCH format 1. PUCCH format 2 can occupy one or two OFDM symbols and can include more than two bits. If more than one or two symbols are transmitted and the number of UCI bits is two or more, the UE can use PUCCH format 2. PUCCH format 3 can occupy between four and fourteen OFDM symbols and can include more than two bits. If four or more symbols are transmitted, the number of UCI bits is two or more, and the PUCCH resource does not include an orthogonal overlay code, the UE can use PUCCH format 3. PUCCH format 4 can occupy between four and fourteen OFDM symbols and can include more than two bits. If four or more symbols are transmitted, the number of UCI bits is two or more, and the PUCCH resource includes an orthogonal overlay code, the UE can use PUCCH format 4.

[0210] The base station can transmit configuration parameters for multiple PUCCH resource sets to the UE using, for example, an RRC message. These multiple PUCCH resource sets (e.g., up to four sets) can be configured on the cell's uplink BWP. A PUCCH resource set can be configured with: a PUCCH resource set index; multiple PUCCH resources identified by a PUCCH resource identifier (e.g., pucch-Resourceid); and / or multiple (e.g., a maximum number) UCI ​​information bits that the UE can transmit using one of the multiple PUCCH resources in the PUCCH resource set. When multiple PUCCH resource sets are configured, the UE can select one PUCCH resource set from the multiple PUCCH resource sets based on the total bit length of the UCI information bits (e.g., HARQ-ACK, SR, and / or CSI). If the total bit length of the UCI information bits is two or less, the UE can select a 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 can select a second PUCCH resource set with 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 can select a third PUCCH resource set with 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 the third value (e.g., 1406), the UE can select a fourth PUCCH resource set with a PUCCH resource set index equal to "3".

[0211] After determining a PUCCH resource set from multiple PUCCH resource sets, the UE can determine the PUCCH resources used for UCI (HARQ-ACK, CSI, and / or SR) transmission from the PUCCH resource set. The UE can determine the PUCCH resources based on the PUCCH resource indicator in the DCI received on the PDCCH (e.g., a DCI with DCI format 1_0 or a DCI for 1_1). The three-bit PUCCH resource indicator in the DCI can indicate one of the eight PUCCH resources in the PUCCH resource set. Based on the PUCCH resource indicator, the UE can use the PUCCH resource indicated by the PUCCH resource indicator in the DCI to transmit UCI (HARQ-ACK, CSI, and / or SR).

[0212] Figure 15 An example of a wireless device 1502 communicating with a base station 1504 according to an embodiment of this disclosure is shown. Both the wireless device 1502 and the base station 1504 can 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 The diagram shows only one wireless device 1502 and one base station 1504, but it should be understood that a mobile communication network may include more than one UE and / or more than one base station, which have the same characteristics as... Figure 15 The same or similar configurations shown.

[0213] Base station 1504 can connect wireless device 1502 to the core network (not shown) via radio communication through air interface (or radio interface) 1506. The communication direction from base station 1504 to wireless device 1502 via air interface 1506 is referred to as the downlink, while the communication direction from wireless device 1502 to base station 1504 via air interface 1506 is referred to as the uplink. Downlink transmissions can be separated from uplink transmissions using some combination of FDD, TDD, and / or two duplex technologies.

[0214] In the downlink, data to be transmitted from base station 1504 to wireless device 1502 can be provided to processing system 1508 of base station 1504. The data can be provided to processing system 1508 via, for example, a core network. In the uplink, data to be transmitted from wireless device 1502 to base station 1504 can be provided to processing system 1518 of wireless device 1502. Processing systems 1508 and 1518 can implement Layer 3 and Layer 2 OSI functions to process the data for transmission. Layer 2 may include, for example, regarding… Figure 2A , Figure 2B , Figure 3 and Figure 4A The SDAP layer, PDCP layer, RLC layer, and MAC layer. Layer 3 may include, for example, the SDAP layer, PDCP layer, RLC layer, and MAC layer. Figure 2B The RRC layer.

[0215] After being processed by processing system 1508, data to be sent to wireless device 1502 can be provided to transmission processing system 1510 of base station 1504. Similarly, after being processed by processing system 1518, data to be sent to base station 1504 can be provided to transmission processing system 1520 of wireless device 1502. Transmission processing systems 1510 and 1520 can implement Layer 1 OSI functions. Layer 1 may include information about... Figure 2A , Figure 2B , Figure 3 and Figure 4A The PHY layer. For transmission processing, the PHY layer can perform operations such as forward error correction coding of the transport channel, interleaving, rate matching, mapping of the transport channel to the physical channel, modulation of the physical channel, multiple-input multiple-output (MIMO) or multiple-antenna processing, etc.

[0216] At base station 1504, receiving processing system 1512 can receive uplink transmissions from wireless device 1502. At wireless device 1502, receiving processing system 1522 can receive downlink transmissions from base station 1504. Receiving processing systems 1512 and 1522 can implement Layer 1 OSI functions. Layer 1 may include information about... Figure 2A , Figure 2B , Figure 3 and Figure 4A The PHY layer. For receive processing, the PHY layer can perform tasks such as error detection, forward error correction decoding, deinterleaving, demapping of the transport channel to the physical channel, demodulation of the physical channel, MIMO or multi-antenna processing, etc.

[0217] like Figure 15 As shown, wireless device 1502 and base station 1504 may include multiple antennas. These multiple antennas can be used to perform 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.

[0218] Processing systems 1508 and 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 can be executed by processing systems 1508 and / or 1518 to perform one or more of the functions discussed in this application. Although Figure 15 Although not shown, the transmission processing system 1510, transmission processing system 1520, receiving processing system 1512 and / or receiving 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 can be executed to perform one or more of their respective functions.

[0219] Processing system 1508 and / or 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 devices, discrete gate and / or transistor logic, discrete hardware components, onboard units, or any combination thereof. Processing system 1508 and / or 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 function that enables wireless device 1502 and base station 1504 to operate in a wireless environment.

[0220] Processing system 1508 and / or processing system 1518 may 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 1526 may include software and / or hardware providing features and / or functions, such as speakers, microphones, keyboards, displays, touchpads, power supplies, satellite transceivers, Universal Serial Bus (USB) ports, hands-free headsets, FM radio units, media players, internet browsers, electronic control units (e.g., for motor vehicles), and / or one or more sensors (e.g., accelerometers, gyroscopes, temperature sensors, radar sensors, lidar sensors, ultrasonic sensors, light sensors, cameras, etc.). Processing system 1508 and / or processing system 1518 may receive user input data from the one or more peripheral devices 1516 and / or 1526 and / or provide user output data to the aforementioned one or more peripheral devices. Processing system 1518 in wireless device 1502 may receive power from a power source and / or may be configured to distribute power to other components in wireless device 1502. The power source may include one or more power sources, such as a battery, a solar cell unit, a fuel cell unit, or any combination thereof. Processing system 1508 and / or processing system 1518 may be connected to GPS chipset 1517 and GPS chipset 1527, respectively. GPS chipset 1517 and GPS chipset 1527 may be configured to provide geographic location information for wireless device 1502 and base station 1504, respectively.

[0221] Figure 16AAn example architecture for uplink transmission is shown. The baseband signal representing the physical uplink shared channel can perform one or more functions. These functions may include at least one of the following: scrambling; modulating scrambling bits to generate complex-valued symbols; mapping complex-valued modulation symbols onto one or more transport layers; transform precoding to generate complex-valued symbols; precoding of complex-valued symbols; mapping 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, etc. 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, it can be achieved through... Figure 16A Generate CP-OFDM signals for uplink transmission. These functions are shown as examples, and other mechanisms are expected to be implemented in various implementation schemes.

[0222] Figure 16B An example architecture for modulation and upsampling of a baseband signal to a carrier frequency is shown. The baseband signal can be a complex-value SC-FDMA or CP-OFDM baseband signal from the antenna port and / or a complex-value Physical Random Access Channel (PRACH) baseband signal. Filtering can be applied before transmission.

[0223] Figure 16C An example structure for downlink transmission is shown. The baseband signal representing the physical downlink channel can perform one or more functions. These functions may include: scrambling coded bits in a codeword to be transmitted over 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 for transmission at the antenna port; mapping the complex-valued modulation symbols for the antenna port to resource elements; generating a complex-valued time-domain OFDM signal for the antenna port, etc. These functions are shown as examples, and other mechanisms are expected to be implemented in various embodiments.

[0224] Figure 16D Another example architecture for modulation and upconversion 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.

[0225] A wireless device can receive one or more messages (e.g., RRC messages) from a base station, including configuration parameters for multiple cells (e.g., primary cell, secondary cell). The wireless device can communicate with at least one base station (e.g., two or more base stations in dual connectivity) via multiple cells. One or more messages (e.g., as part of the configuration parameters) can include parameters for configuring the wireless device at the physical layer, MAC layer, RLC layer, PCDP layer, SDAP layer, and RRC layer. For example, configuration parameters can include parameters for configuring physical and MAC layer channels, bearers, etc. For example, configuration parameters can include parameters indicating the values ​​of timers for the physical layer, MAC layer, RLC layer, PCDP layer, SDAP layer, RRC layer, and / or communication channels.

[0226] A timer can begin running once started and continues running until it stops or expires. If the timer is not running, it can be started, or if it is running, it can be restarted. The timer can be associated with a value (e.g., the timer can start or restart from a certain value, or it can start from zero and expire once it reaches that value). The duration of the timer may not be updated until the timer stops or expires (e.g., due to BWP switching). The timer can be used to measure time periods / windows of a process. When the specification refers to embodiments and procedures relating to one or more timers, it should be understood that there are multiple ways to implement the one or more timers. For example, it should be understood that one or more of the multiple ways of implementing a timer can be used to measure time periods / windows of a process. For example, a random access response window timer can be used to measure a time window for receiving a random access response. In the example, instead of starting and expiring the random access response window timer, the time difference between two timestamps can be used. When the timer restarts, the measurement process for the time window can be restarted. Other example embodiments for restarting the measurement of a time window can be provided.

[0227] When an RRC connection is established, the UE can be in either an RRC connected state or an RRC inactive state. When no RRC connection is established, the UE is in an RRC idle state.

[0228] When the UE is in RRC idle state, the UE (its RRC layer) or the base station can support PLMN selection; broadcasting system information; cell reselection mobility; paging for mobile termination data initiated by the 5GC; and DRX for paging to the core network (CN) configured by the non-access stratum (NAS). When the UE is in RRC idle state, UE-specific DRX can be configured by the upper layer; and / or the UE controls mobility based on network configuration. When the UE is in RRC idle state, the UE (its RRC layer) can: monitor short messages transmitted via DCI in P-RNTI; monitor paging channels for core network (CN) paging using the Serving Temporary Mobile Subscriber Identity (S-TMSI) (e.g., 5G-S-TMSI); perform neighbor cell measurements and cell (re)selection; acquire system information; send SI requests; perform recording of available measurements and configure the UE's location and time for the recorded measurements.

[0229] When a UE is in an RRC inactive state, the UE (its RRC layer) or the base station can support PLMN selection; broadcasting system information; cell reselection mobility; paging initiated by NG-RAN (RAN paging); RAN-based notification areas (RNAs) managed by NG-RAN; DRX for RAN paging configured by NG-RAN; core network (e.g., 5G core, 5GC) – establishing RAN (e.g., base station) connections (control plane and / or user plane) for the UE; storing the UE AS context in both 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 DRXs can be configured by the upper layer or the RRC layer; the UE can perform / support UE-controlled mobility based on network configuration; the UE can store the UE inactive AS context; and RAN-based notification areas (RNAs) can be configured by the RRC layer. When the UE is in an RRC inactive state, the UE (its RRC layer) can: monitor short messages transmitted via DCI using P-RNTI; monitor paging channels for CN paging using S-TMSI and monitor paging channels for RAN paging using fully inactive RNTI (I-RNTI) (or fully restored identity); perform neighboring 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 SI requests; perform recording of available measurements and configure the UE's location and time for the recorded measurements.

[0230] When the UE is in an RRC connection state, the UE (at the RRC layer) or the base station can support: 5GC - establishing an NG-RAN connection for the UE (both C-plane and U-plane); storing the UE AS context in the RAN (e.g., the base station) and the UE; the RAN knowing the cell to which the UE belongs; transmitting unicast data to / from the UE; and network-controlled mobility, including measurements. For example, when the UE is in RRC connected state, the UE (at the RRC layer) can: store AS context; transmit / 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 control mobility within NR and to / from E-UTRA; when the UE is in RRC connected state, the UE can: monitor short messages transmitted via DCI in P-RNTI; monitor control channels associated with shared data channels to determine whether to schedule data for that control channel; provide channel quality and feedback information; perform neighbor cell measurements and measurement reports; acquire system information; and perform immediate minimization of drive test (MDT) measurements and available location reports.

[0231] Radio bearers can be divided into two groups: Data Radio Bearers (DRBs) for user plane data and Signaling Radio Bearers (SRBs) for control plane data.

[0232] A Signalling Radio Bearer (SRB) can be defined as a radio bearer (RB) used solely for transmitting RRC and NAS messages. The following SRBs can be defined: SRB0 can be used for RRC messages using the Common Control Channel (CCCH) logical channel; SRB1 can be used for RRC messages (which may include carried NAS messages) and for NAS messages prior to the establishment of SRB2, all of which use the Dedicated Control Channel (DCCH) logical channel; SRB2 can be used for both NAS messages and RRC messages, which may include recorded measurement information, all of which use the DCCH logical channel. SRB2 can have a lower priority than SRB1 and can be configured by the network after Access Layer (AS) security activation; when the UE is in dual connectivity (e.g., (NG)EN-DC or NR-DC), SRB3 can be used for specific RRC messages, all of which use the DCCH logical channel. In the downlink, the carrying of NAS messages can be used for a correlated (e.g., with joint success / failure) scenario. Procedure: Bearer establishment / modification / release. In the uplink, the carrying of NAS messages can be used to deliver the initial NAS message during (RRC) connection setup and (RRC) connection recovery. NAS messages delivered via SRB2 can be included 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 via PDCP. NAS can independently apply integrity protection and encryption to NAS messages. Separate SRBs can be supported for dual connectivity (e.g., multiple radio (MR)-DC option) in both SRB1 and SRB2. Separate SRBs may not be supported for SRB0 and SRB3. For operations utilizing shared spectrum channel access, SRB0, SRB1, and SRB3 can be assigned the highest priority channel access priority class (CAPC) (e.g., CAPC=1), while the CAPC for SRB2 is configurable.

[0233] The MAC layer of a UE or base station can provide different types of data transmission services. Each logical channel type can be defined by the type of information transmitted. Logical channels can be divided into two groups: control channels and traffic channels. Control channels can be used to transmit control plane information: Broadcast Control Channel (BCCH), which is a downlink channel used to broadcast system control information; Paging Control Channel (PCCH), which is a downlink channel carrying paging messages; Common Control Channel (CCCH), which is used to transmit control information between the UE and the network. This channel is used by UEs without an RRC connection to the network; and Dedicated Control Channel (DCCH), which is a point-to-point bidirectional channel used by the UE to transmit dedicated control information between the UE and the network. It is used by UEs with an RRC connection. Traffic channels can be used to transmit user plane information: Dedicated Traffic Channel (DTCH), which is a point-to-point channel dedicated to a single UE for transmitting user information. DTCH can exist in both the uplink and downlink.

[0234] When an RRC connection is established or resumed, the UE can transition to an RRC connected state. When an RRC connection is released or suspended, the UE can transition to an RRC idle state. When an RRC connection is suspended, the UE can transition to an RRC inactive state. When the UE is in an RRC idle state, the UE can have a suspended RRC connection. Based on the suspended RRC connection in the RRC idle state, the UE is in an RRC idle state with a suspended RRC connection.

[0235] RRC connection establishment may include the establishment of SRB1. The base station can complete RRC connection establishment before completing 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)). Access stratum (AS) security may not be activated during the initial phase of the RRC connection. During the initial phase of the RRC connection, the base station can configure the UE to perform measurement reporting. After successful AS security activation, the UE can send the corresponding measurement report. When AS security is activated, the UE can receive or accept handover messages (e.g., handover commands).

[0236] When the UE context is received from the core network (e.g., AMF), the RAN (base station) can use an initial security activation procedure to activate AS security (both encryption and integrity protection). The RRC messages (command and success response) used to activate AS security can be integrity protected, with encryption beginning after the procedure completes. Responses to the RRC messages used to activate AS security may not be encrypted, while subsequent messages (e.g., those used to establish SRB2 and DRB) can be both integrity protected and encrypted. After the initial AS security activation procedure has been initiated, the network (e.g., the base station) can initiate the establishment of SRB2 and DRB; for example, the network can do so before receiving confirmation of the initial AS security activation from the UE. The network can apply both encryption and integrity protection to the RRC reconfiguration messages used to establish SRB2 and DRB. If the initial AS security activation and / or radio bearer establishment fails, the network should release the RRC connection. Configurations with SRB2 without DRB or DRB 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-MT), configurations with SRB2 but without DRB are supported.

[0237] The release of an 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.

[0238] The suspension of an RRC connection can be initiated by the network. When an RRC connection is suspended, the UE can store the UE inactive AS context and any configuration received from the network, and transition to an RRC inactive state. The RRC message used to suspend the RRC connection can be protected by integrity and encrypted.

[0239] When a UE needs to transition from an RRC inactive state to an RRC connected state, the restoration of the suspended RRC connection can be initiated by the upper layer, or by the RRC layer to perform an RNA update, or by RAN paging from the RAN (e.g., a base station). When the RRC connection is restored, the network can configure the UE according to the RRC connection restoration procedure based on the stored UE inactive AS context and any RRC configuration received from the network. The RRC connection restoration procedure reactivates AS security and rebuilds the SRB and DRB.

[0240] In response to a request to restore an RRC connection, the network can either restore a suspended RRC connection and put / transition the UE into an RRC connected state, or reject the restoration request and (using a wait timer) put the UE into an RRC inactive state, or directly re-suspend the RRC connection and put the UE into RRC_INACTIVE, or directly release the RRC connection and put / transition the UE into an RRC idle state, or instruct the UE to initiate a NAS-level recovery (in which case the network sends an RRC setup message). For User Data Bundles (DRBs), encryption provides confidentiality, and integrity protection provides integrity. For RRC Signaling Bundles (SRBs), encryption provides confidentiality and integrity protection for signaling data. In addition to RRC signaling with integrity protection always being configured, encryption and integrity protection can be optionally configured. Encryption and integrity protection can be configured for each DRB.

[0241] For key management and data processing, network entities or UEs processing plaintext can be protected from physical attacks and located in a secure environment. Base station (e.g., gNB or eNB) (AS) keys can be encrypted separately from (NAS) keys. Separate AS and NAS-level Security Mode Command (SMC) procedures can be used. A serial number (COUNT) can be used as input for both encryption and integrity protection, and a given serial number can be used once on the same radio bearer in the same direction for a given key (except for identical retransmissions).

[0242] Security keys can be organized and derived as follows: Keys for core network entities (e.g., AMF or keys for Mobility Management Entities (MMEs)) may include KAMF (or KMME). Keys for core network entities can be keys derived from keys for SEAFs (KSEAF) by the UE's mobile device (ME) and Security Anchor Function (SEAF). Keys for NAS signaling may include: KNASint, a key derived from keys for core network entities by the UE's mobile device (ME) and the core network, which can be used to protect NAS signaling using specific integrity algorithms; and KNASenc, a key derived from keys for core network entities (e.g., KAMF / KMME) by the ME and the core network entity, which can be used to protect NAS signaling using specific encryption algorithms. Keys for base stations (e.g., gNBs or eNBs) may include KgNBs (or KeNBs), which are keys derived from keys for core network entities (e.g., KAMF / KMME) by the ME and the core network entity (e.g., AMF / MME). When performing horizontal or vertical key derivation, the ME and the source base station can further derive base station-specific keys. Keys for UP services may include: KUPenc, a key derived by the ME and base station from the base station-specific keys, which can be used to protect UP services between the ME and the base station using specific encryption algorithms; and KUPint, a key derived by the ME and base station from the base station-specific keys, which can be used to protect UP services between the ME and the base station using specific integrity algorithms. Keys for RRC signaling may include: KRRCint, a key derived by the ME and base station from the base station-specific keys, which can be used to protect RRC signaling using specific integrity algorithms; and KRRCenc, a key derived by the ME and base station from the base station-specific keys, which can be used to protect RRC signaling using specific encryption algorithms. Intermediate keys may include: the next-hop parameter (NH), a key derived by the ME and core network entities (e.g., AMF / MME) to provide forward security; and KgNB* (or KeNB*), a key derived by the ME and base station during horizontal or vertical key derivation.

[0243] Master authentication enables mutual authentication between the UE and the network and provides an anchor key known as KSEAF. Based on KSEAF, keys for core network entities (such as KAMF / KMME) can be created during events such as master authentication, NAS key reset, and key refresh. Based on these core network entity keys, KNASint and KNASenc can be exported when a successful NAS SMC procedure is run.

[0244] Whenever an initial AS security context needs to be established between the UE and a base station, the core network entity (e.g., AMF / MME) and the UE can derive a key and next-hop parameter (NH) for the base station (e.g., KgNB / KeNB). The key for the base station and NH can be derived from the key 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 the NCC corresponding to the NH value from which the key is derived. During initial setup, the key for the base station can be directly derived from the key for the core network entity and is subsequently treated as associated with a virtual NH parameter with an NCC value equal to zero. During initial setup, the derived NH value can be associated with an NCC value of one. During handover, the basis of the key for the base station to be used between the UE and the target base station (referred to as KgNB* (or KeNB*)) can be derived from the currently active key or NH parameter for the base station. If KgNB* (or KeNB*) can be derived from the currently active key for the base station, this is called horizontal key deriving and is indicated to the UE with a non-incrementing NCC. If KgNB* (or KeNB*) is derived from the NH parameters, this derive is called a vertical key derive and is indicated to the UE with NCC. 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.

[0245] Based on key derivation, a base station that knows the key for a base station shared with the UE (e.g., KgNB / KeNB) may not be able to compute any previous KgNB already used between the same UE and a previous base station, thus providing backward security. A base station that knows the key for a base station shared with the UE may not be able to predict any future keys for a 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 computed by the UE and core network entities (e.g., AMF / MME)).

[0246] The AS SMC procedure can be used for RRC and UP security algorithm negotiation and RRC security activation. When an 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 is also 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 is also present in the security capabilities. The selected algorithm can be indicated to the UE in the AS SMC, and integrity protection can be performed on this message. RRC downlink ciphering at the base station can begin after sending the AS SMC message. RRC uplink deciphering at the base station can begin after receiving and successfully verifying the integrity protection AS security mode completion 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 encryption at the UE can begin after sending the AS security mode completion message. RRC downlink decryption (decryption) at the UE can begin after receiving and successfully verifying the AS SMC message. The RRC connection reconfiguration procedure for adding a DRB can only be executed after RRC security has been activated as part of the AS SMC procedure.

[0247] The UE can support DRBs with integrity protection. In the event of an integrity check failure (e.g., an error or loss of the integrity-based Message Authentication Code (MAC-I)), the relevant Packet Data Unit (PDU) can be discarded by the receiving PDCP entity. Key refresh is possible for base station keys (KgNB / KeNB), KRRC-enc, KRRC-int, KUP-enc, and KUP-int, and can be initiated by the base station when the PDCP COUNT will be reused with the same radio bearer identifier and the same KgNB. Key reset is possible for base station keys (KgNB / KeNB), KRRC-enc, KRRC-int, KUP-enc, and KUP-int, and can be initiated by core network entities (e.g., AMF / MME) when a different AS security context than the currently active one may be activated.

[0248] When a UE transitions from an RRC idle state to an RRC connected state, an RRC protection key and an UP protection key can be generated, assuming that the key 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 negotiation (AKA), or as a result of transmission from another AMF during handover or idle mode mobility. When a UE transitions from an RRC connected state to an RRC idle state, the base station can delete its stored keys for that UE, so that the state information for idle mode UEs only needs to be maintained in core network entities (e.g., AMF / MME). The base station may stop storing state information about the corresponding UE and delete the current key from its memory (e.g., when changing the RRC connected state to the RRC idle state): the base station and the UE may delete NH, the key for the base station, KgNB, KRRCint, KRRCenc, KUPint and KUPenc and the associated NCC; the core network entity (e.g., AMF / MME) and the UE may retain the key for the core network entity (e.g., KAMF / KMME), the stored KNASint and KNASenc.

[0249] In mobility with vertical key derivation, the NH can be further bound to the target Physical Cell Identifier (PCI) and its frequency absolute radio channel number-downlink link (ARFCN-DL) before being used as the key for the target base station. 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, and then this current active key is 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 handover within the gNB Central Cell (CU), it may not be necessary to change the AS security algorithm. If the UE does not receive an indication of a new AS security algorithm during handover within the gNB-CU, the UE can continue to use the same algorithm as before the handover.

[0250] AS security can include integrity protection and encryption of RRC signaling (SRB) and user data (DRB). The AS can apply four different security keys: a security key for integrity protection of RRC signaling (KRRCint), a security key for encryption of RRC signaling (KRRCenc), a security key for integrity protection of user data (KUPint), and a security key for encryption of user data (KUPenc). These four AS keys can be derived from base station keys (e.g., KgNB / KgNB). Base station keys can be based on core network entity keys (KAMF / KMME), which can be processed by upper layers (e.g., the NAS layer). Integrity protection and encryption algorithms can be changed using synchronized reconfiguration (e.g., handover commands). The AS keys (KgNB, KRRCint, KRRCenc, KUPint, and KUPenc) can be changed during synchronized reconfiguration and during connection re-establishment and restoration. 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.

[0251] Paging allows base stations to reach UEs in RRC idle and RRC inactive states via paging messages, notify UEs in these states of system information changes, and notify 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 P-RNTI on the PDCCH. Paging messages can be sent on the PCCH, while short messages can be sent directly via the PDCCH.

[0252] When a UE is in RRC idle state, it can monitor the paging channel for paging initiated by the core network (CN). When a UE is in RRC inactive state, it can monitor the paging channel for paging initiated by the RAN. However, a UE may not need to continuously monitor the paging channel. A paging DRX is defined as a UE in RRC idle or RRC inactive state that may only need to monitor the paging channel during one paging opportunity (PO) of each DRX cycle. The paging DRX cycle can be configured by the network (e.g., a base station or core network entity (e.g., AMF / MME)): for CN-initiated paging, a default cycle can be broadcast in system information; for CN-initiated paging, a UE-specific cycle can be configured via NAS signaling; for RAN-initiated paging, a UE-specific cycle can be configured via RRC signaling; the UE can use the shortest DRX cycle available. For example, a UE in RRC idle state can use the shortest cycle of the first two cycles mentioned above. A UE in RRC_INACTIVE state can use the shortest cycle of the three cycles mentioned above.

[0253] The Page Points (POs) for UEs used for CN-initiated paging and RAN-initiated paging can be based on the same UE identifier (ID), resulting in PO overlap for both. The number of different POs in the DRX cycle can be configured via system information, and the network can distribute UEs to those POs based on the UE ID.

[0254] When in RRC_CONNECTED state, the UE can monitor paging channels in any PO (Position Provider) signaled in the system information for SI (System Indicator) change indication and PWS (Personal Web Message) notification. A UE in RRC connected state can only monitor paging channels on active BWPs configured with a common search space. For operations using shared spectrum channel access, the UE can be configured to monitor an additional number of PDCCH monitoring opportunities in its PO for paging. When the UE detects a PDCCH transmission within a PO of a UE addressed by P-RNTI, the UE may not need to monitor subsequent PDCCH monitoring opportunities within that PO.

[0255] A network (e.g., a base station) can initiate a paging procedure by transmitting a paging message at the paging time of the UE. The network can address multiple UEs within the paging message by including one paging record for each UE. The paging message may include a list of paging records. The list of paging records may include one or more paging records. Each paging record may include at least one of the following: UE identifier (ID) and access type. The UE identifier may include S-TMSI or 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.

[0256] The transitions from Register-Management (RM) to Deregistered (RM-DEREGISTERED) to RM-Registered (RM-REGISTERED), from CM-Idle (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 network registration. A UE in the CM-IDLE state may not have (e.g., via the N1 / S1 interface) a NAS signaling connection established with a core network entity (e.g., AMF / MME). The UE can perform cell selection / cell reselection and PLMN selection. A UE in CM-CONNECTED state can have (e.g., via the N1 / S1 interface) a NAS signaling connection with a core network entity. The NAS signaling connection can be associated with an RRC connection between the UE and a base station (e.g., RAN) and a Next Generation Application Protocol (NGAP) / S1AP UE connection between the access network (AN) (e.g., the AN of the base station) and a core network entity (e.g., AMF / MME).

[0257] Cell selection can be based on the following principles. The UE NAS layer can identify the selected PLMN and the equivalent PLMN. Cell selection can be based on the cell definition SSB (CD-SSB) located on the synchronization grating: the UE can search the frequency (NR) band and identify the strongest cell for each carrier frequency according to the CD-SSB. The UE can then read the cell system information broadcast to identify its PLMN: the UE can search each carrier sequentially (“Initial Cell Selection”) or shorten the search using stored information (“Stored Information Cell Selection”). The UE can seek to identify a suitable cell; if the UE cannot identify a suitable cell, it seeks 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 procedure: a suitable cell is one that: the measured cell attributes meet the cell selection criteria; the cell PLMN is a selected PLMN, a registered PLMN, or an equivalent PLMN; the cell is not banned or reserved, and the cell is not part of the tracking area in the “No Tracking Areas for Roaming” list; an acceptable cell is one whose measured cell attributes meet the cell selection criteria and is not banned.

[0258] When transitioning from RRC connected or inactive to RRC idle, the UE can camp on the cell selected as a result of cell selection based on the frequency assigned by the RRC in the state transition message. The UE can attempt to find a suitable cell using the methods described above for stored information or initial cell selection. If no suitable cell is found on any frequency or RAT, the UE can attempt to find an acceptable cell. In multi-beam operation, cell quality can be derived between beams corresponding to the same cell.

[0259] A UE idle in RRC can perform cell reselection. The procedure follows these principles: Cell reselection can be based on the CD-SSB located on the synchronization grating. The UE can measure the attributes of the serving cell and neighboring cells to enable the reselection procedure: for searching and measuring inter-frequency neighboring cells, the carrier frequency needs to be indicated. Cell reselection can identify the cell the UE should camp on. Cell reselection can be based on cell reselection criteria involving measurements of the serving cell and neighboring cells: intra-frequency reselection is based on cell ordering; inter-frequency reselection is based on absolute priority, where the UE attempts to camp on the highest priority frequency available; the Neighboring Cell List (NCL) can be provided by the serving cell to handle specific cases of intra-frequency and inter-frequency neighboring cells; a blacklist can be provided to prevent the UE from reselecting to specific intra-frequency and inter-frequency neighboring cells; a whitelist can be provided to request the UE to reselect only to specific intra-frequency and inter-frequency neighboring cells; cell reselection can depend on speed; service-specific priority. In multi-beam operation, cell quality can be derived between beams corresponding to the same cell.

[0260] The UE can execute one of two procedures, such as initial cell selection and cell selection using stored information. When the UE has not yet stored cell information for a selected PLMN, it can perform initial cell selection. Otherwise, the UE can perform cell selection using stored information. For initial cell selection, the UE can scan all RF channels in the (NR) band based on its ability to find suitable cells. Based on the scan results, the UE can search for the strongest cell at each frequency. The UE can then select a cell as a suitable cell. For cell selection using stored information, the UE may need 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, it can search for and select that cell. If the UE does not find a suitable cell, it can perform initial cell selection.

[0261] The base station can configure cell selection criteria for cell selection. The UE can seek to identify cells suitable for cell selection. A suitable cell is one that meets the following conditions: (1) the measured cell attributes meet the cell selection criteria, (2) the cell PLMN is a selected PLMN, a registered PLMN, or an equivalent PLMN, (3) the cell is not banned or reserved, and (4) the cell is not part of a tracking area in the "Roaming Prohibited Tracking Areas" list. The RRC layer in the UE can notify the NAS layer in the UE of cell selection and reselection results based on changes in received system information related to NAS. For example, cell selection and reselection results can be cell identifiers, tracking area codes, and PLMN identifiers.

[0262] The UE-RRC layer can initiate RRC connection establishment procedures, RRC connection recovery procedures, or RRC connection reconstruction procedures. Based on the initiation of an RRC connection establishment procedure or an RRC connection restoration procedure, the UE may execute 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 prohibition check) for an access attempt in an RRC establishment / restoration procedure on the 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); for example, based on an allowed access attempt, performing the sending of a random access preamble to the serving cell; sending an RRC request message to the serving cell (e.g., sending an RRC request message to serving cell 0 based on a successful receipt of a random access response; starting a timer based on sending the RRC request message; receiving an RRC response message or an RRC rejection message from the serving cell (e.g., in response to the RRC request message); or sending an RRC completion message (e.g., sending an RRC completion message in response to receiving an RRC response message). For an RRC connection reconstruction procedure, the UE may not perform a unified access procedure (e.g., access prohibition check) for an access attempt in an RRC reconstruction procedure.

[0263] 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 denial mechanisms. A unified access control framework applies to all UE states (e.g., RRC idle, inactive, and connected states). Base stations can broadcast denial control information associated with access category and access identifier (in the case of network sharing, denial control information can be set individually for each PLMN). UEs can determine whether an access attempt is authorized based on the denial information broadcast for the selected PLMN, the selected access category, and the access identifier of the access attempt. For NAS-triggered requests, the UE-NAS layer can determine the access category and access identifier. For AS-triggered requests, the UE-RRC layer determines the access category, while the NAS layer determines the access identifier. Base stations can handle access attempts with high-priority establishment reasons such as "emergency," "MPS priority access," and "MCS priority access" (e.g., emergency calls, MPS, MCS subscribers), and respond to these access attempts with RRC rejection only under extreme network load conditions that may threaten base station stability.

[0264] Based on initiating an RRC connection establishment procedure or an RRC connection recovery procedure, a UE in an RRC inactive or idle state can perform or initiate an access denial check (or unified access control procedure) for an access attempt during an RRC connection establishment or recovery procedure. Based on performing or initiating the access denial check, the UE can determine the access category and access identifier of the access attempt. The UE can determine that the access attempt is denied 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 can determine that an access attempt is allowed 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) denial parameter is not broadcast by the serving cell. The UE may determine that an access attempt is blocked based on at least one of the following: the establishment reason (e.g., for the access attempt) is not an emergency; the access blocking for each RSRP parameter of the system information block includes (or is set to) threshold 0, and the radio device is in enhanced coverage; the access blocking for each RSRP parameter of the system information block includes (or is set to) threshold 1, and the measured RSRP is less than the first entry in the RSRP threshold PRACH information list; the access blocking parameter for each RSRP of the system information block includes (or is set to) threshold 2, and the measured RSRP is less than the second entry in the RSRP threshold PRACH information list; and the access blocking for each RSRP parameter of the system information block includes (or is set to) threshold 3, and the measured RSRP is less than the third entry in the RSRP threshold PRACH information list.

[0265] The UE can determine that an access attempt is permitted based on the fact that the system information block does not contain UAC prohibition parameters for the access attempt. For example, the UE can determine that the access attempt is permitted based on the fact that the system information block does not contain UAC prohibition parameters for the PLMN selected by the UE and common UAC prohibition parameters. The UE can determine that the access attempt is permitted based on the fact that the common UAC prohibition parameters do not contain the access category of the access attempt. UAC prohibition parameters may include at least one of the following: per-PLMN UAC prohibition parameters; and UAC prohibition parameters. The UE can perform an access prohibition check on the access category of the access attempt based on the UAC prohibition parameters in the system information block. The UE can determine that the access attempt is permitted based on the fact that at least one corresponding bit of the access identifier in the UAC prohibition parameters is zero. The UE can draw a first random number uniformly distributed within a range, where the range is greater than or equal to 0 and less than 1.

[0266] The UE can determine that an access attempt is permitted based on a first random number lower than the UAC prohibition factor in the UAC prohibition parameters. The UE can determine that an access attempt is prohibited based on a first random number greater than the UAC prohibition factor in the UAC prohibition parameters. In response to determining that an access attempt is prohibited, the UE can draw a second random number uniformly distributed within a range greater than or equal to 0 and less than 1. The UE can start a prohibition timer T309 for the access class based on the second random number. While the prohibition timer T309 is running, the access attempt associated with the access class is prohibited (e.g., transmission is not allowed). Upon the expiration of the prohibition timer T309, the UE can consider the prohibition for the access class to be mitigated. Based on the mitigation of the prohibition for the access class, if the UE has an access attempt for that access class, the UE can perform an access prohibition check for that access class.

[0267] Based on initiating the RRC connection reconstruction procedure, if one or more disable timers T309 are running, the UE can stop one or more disable timers T309 for all access categories. By stopping one or more disable timers T309, the UE can determine that the disablement for all access categories is being mitigated. The UE can execute the RRC connection reconstruction procedure based on the mitigation of the disablement for all access categories. For example, based on the mitigation of the disablement for all access categories, the UE can send an RRC reconstruction request even without a disablement.

[0268] To initiate RRC connection establishment / restoration / reconstruction procedures, the UE-RRC layer can use parameters from the received SIB1. The UE-RRC layer can use L1 parameter values ​​and time alignment timers from SIB1. The UE-RRC layer can use UAC prohibition information from SIB1 to execute unified access control procedures. Based on the unified access control procedures, the UE-RRC layer can determine whether access attempts for these RRC procedures are prohibited or permitted. If the access attempt is permitted, the UE-RRC layer can determine to send an RRC request message to the base station, where the RRC request message can be an RRC setup 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 a UE identifier. The UE-RRC layer can set the UE identifier in the RRC request message.

[0269] For RRC setup request messages, a UE in an RRC idle state can initiate an RRC connection establishment procedure. Based on initiating the RRC connection establishment procedure, if the UE-NAS layer provides an S-TMSI, the UE-RRC layer in an RRC idle state can set the UE identifier to the S-TMSI. Otherwise, the UE-RRC layer in an RRC idle state can extract a 39-bit random value and set the UE identifier to that random value. For RRC recovery request messages, a UE-RRC layer in an RRC inactive or idle state can set the UE identifier to the restored stored identifier. For RRC rebuild request messages, a UE-RRC layer in an RRC connected state can set the UE identifier to the C-RNTI used in the source PCell. The UE-NAS layer can provide a establishment reason (e.g., the UE-NAS layer itself). The UE-RRC layer can set the establishment reason for RRC request messages.

[0270] For RRC recovery request messages, a UE in an RRC inactive state can initiate an RRC connection recovery procedure. A UE in an RRC idle state with a suspended RRC connection can initiate an RRC connection recovery procedure. A UE in an RRC inactive or idle state can initiate an RRC connection procedure based on at least one of the following: restoring (suspending) the RRC connection; and performing / initiating UP small data transfer. Based on initiating the RRC connection recovery procedure, the UE-RRC layer can recover the stored configuration parameters and 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 can set the recovered 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 recovery 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). 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 stored NCC values ​​and recovery identifiers. The UE may receive an RRC release message with a pause indication (or pause configuration parameters), wherein the RRC release message includes at least one of the following: a recovery identifier; and an NCC value. The UE-RRC layer in an RRC inactive or idle state may rebuild PDCP entities for one or more bearers. The UE-RRC layer may recover one or more bearers. For example, based on recovering RRC connectivity, the UE-RRC layer may recover SRB1. Based on the execution of UP small data transmission, the UE-RRC layer can restore one or more SRBs and DRBs. A UE-RRC layer in an RRC inactive or idle state can send an RRC recovery request message to the base station, wherein the RRC recovery request message may contain at least one of the following: recovery identifier; recovery MAC-I; and recovery reason.

[0271] For an RRC re-establishment request message, a UE in RRC connected state can initiate an RRC connection re-establishment procedure. Based on initiating the RRC connection re-establishment procedure, the UE-RRC layer in RRC connected state can include the physical cell identifier of the source PCell and a short MAC-I in the RRC re-establishment message. The UE-RRC layer in RRC connected state can 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 for the integrity protection of the RRC layer (which is used in the source PCell or the PCell in which the re-establishment is triggered), and other security parameters (e.g., count, bearer, and direction). The variable short MAC input can 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 RRC connected state can reconstruct the PDCP entity and RLC entity for SRB1 and apply the default SRB1 configuration parameters to SRB1. A UE-RRC layer in an RRC connection state can configure a lower layer (e.g., PDCP layer) to suspend SRB1 integrity protection and encryption, and then resume SRB1.

[0272] The UE-RRC layer can send RRC request messages to lower layers (e.g., PDCP layer, RLC layer, MAC layer and / or PHY layer) for transmission. The RRC request message can be an RRC setup request message, an RRC recovery request message or an RRC reconstruction message.

[0273] The UE-RRC layer can receive RRC setup messages in response to RRC recovery request messages or RRC reconstruction request messages. Based on the RRC setup message, the UE-RRC layer can discard any stored AS context, pause configuration parameters, and current AS security context. The UE-RRC layer can release radio resources of all established RBs except SRB0, including releasing associated PDCP entities and SDAP RLC entities. The UE-RRC layer can release RRC configurations except for default L1 parameter values, default MAC cell group configurations, and CCCH configurations. The UE-RRC layer can indicate the fallback of RRC connections to higher layers (e.g., the NAS layer). If timer T380 is running as a periodic RAN-based notification area (RNA) update timer, the UE-RRC layer can stop timer T380.

[0274] The UE-RRC layer can receive an RRC setup message in response to an RRC setup request message, an RRC recovery request message, or an RRC reconstruction request message. The RRC setup message may include cell group configuration parameters and radio bearer configuration parameters. Radio bearer configuration parameters may include at least one of signaling bearer configuration parameters, data radio bearer configuration parameters, and / or security configuration parameters. Security configuration parameters may include security algorithm configuration parameters and a key usage indication indicating whether a master key or a secondary key is used for the radio bearer configuration parameters. Signaling radio bearer configuration parameters may include one or more signaling radio bearer configuration parameters. Each signaling radio bearer configuration parameter may include at least one of an SRB identifier, a PDCP configuration parameter, a PDCP reconstruction indication, and / or a PDCP discard indication. Data radio bearer configuration parameters may include one or more data radio bearer configuration parameters. Each data radio bearer configuration parameter may include at least one of a DRB identifier, a PDCP configuration parameter, an SDAP configuration parameter, a PDCP reconstruction indication, and / or a PDCP restoration 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 can establish SRB1. Based on the RRC setup message, the UE-RRC layer can perform cell group configuration or radio bearer configuration. The UE-RRC layer can stop the disable timer and wait timer to allow the cell to send the RRC setup message. Upon receiving the RRC setup message, the UE-RRC layer can perform one or more of the following: transition to RRC connected state; stop the cell reselection process; treat the current cell that sent the RRC setup message as a PCell; or / and send an RRC establishment completion message by configuring the content of the RRC establishment completion message.

[0275] The UE-RRC layer can receive an RRC recovery message in response to an RRC recovery request message. Based on the RRC recovery message, the UE-RRC layer can discard the UE inactive AS context and release the paused configuration parameters except for the RNA notification area information. The RRC recovery message may include at least one of the following: radio bearer configuration parameters; cell group configuration parameters; measurement configuration parameters; an 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 recovery message, the UE-RRC layer can perform procedures for configuring or restoring configuration parameters (e.g., cell group configuration, radio bearer configuration, and / or SCG configuration); a security key update procedure; and / or a measurement (configuration) procedure. Based on the received RRC recovery message, the UE-RRC layer may perform one or more of the following: indicate to the upper layer (e.g., the NAS layer) that the suspended RRC connection has been restored; restore SRB2, all DRBs and measurements; enter the RRC connection state; stop the cell reselection process; treat the current cell that sent the RRC recovery message as a PCell or / and send the RRC recovery completion message by setting the content of the RRC recovery completion message.

[0276] Cell group configuration parameters can be used to configure a primary cell group (MCG) or a secondary cell group (SCG). If the cell group configuration parameters are used to configure an MCG, then the cell group configuration parameters are primary cell group configuration parameters. If the cell group configuration parameters are used to configure an SCG, then the cell group configuration parameters are secondary cell group configuration parameters. A cell group comprises a MAC entity, logical channels with associated RLC entities, a primary cell (SpCell), and a collection of one or more secondary cells (SCells). Cell group configuration parameters (e.g., primary cell group configuration parameters or secondary cell group configuration parameters) may include at least one of the following: RLC bearer configuration parameters of the cell group, MAC cell group configuration parameters of the cell group, physical cell group configuration parameters of the cell group, SpCell configuration parameters of the cell group, or SCell configuration parameters of the cell group. MAC cell group configuration parameters may include MAC parameters of the cell group, wherein the MAC parameters may include at least DRX parameters. Physical cell group configuration parameters may include cell group-specific L1 (Layer 1) parameters.

[0277] A special cell (SpCell) can include the primary cell (PCell) of an MCG or the primary SCG cell (PSCell) of an SCG. SpCell configuration parameters may include serving cell-specific MAC and PHY parameters for the SpCell. MR-DC configuration parameters may include at least one of the following: SRB3 configuration parameters, SCG measurement configuration parameters, and SCG configuration parameters.

[0278] Cell group configuration parameters may include at least one of the following: RLC bearer configuration parameters of the first cell group, MAC cell group configuration parameters, physical cell group configuration parameters, SpCell configuration parameters, or SCell configuration parameters of other cells of the second base station. SpCell configuration parameters may include at least one of the following: radio link failure timer and constraints, radio link monitoring in synchronization / dissynchronization thresholds, and / or serving cell configuration parameters of the first cell. Serving cell configuration parameters may include at least one of the following: downlink BWP configuration parameters; uplink configuration parameters; uplink configuration parameters (SUL) for supplementary uplink carriers; 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 for the serving cell; timing advance group (TAG) identifier (ID) for 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 for the access procedure of shared spectrum channel access operation. CSI measurement configuration parameters can include configuring the CSI-RS (reference signal) belonging to the serving cell, configuring 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.

[0279] In the example, downlink BWP configuration parameters can be used to configure dedicated (UE-specific) parameters for one or more downlink BWPs. 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. Downlink BWP configuration parameters may include at least one of the following: configuration parameters for one or more downlink BWPs; one or more downlink BWP IDs for one or more downlink BWPs; and a BWP inactivity timer. 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 failures of the downlink BWP. One or more downlink BWP IDs may include at least one of an initial downlink BWP ID, a default downlink BWP identifier (ID), and a first active downlink BWP ID.

[0280] In the example, uplink configuration parameters can be uplink configuration parameters for a normal uplink carrier (not a supplementary uplink carrier). Uplink configuration parameters (or uplink configuration parameters for SUL) can be used to configure dedicated (UE-specific) parameters for one or more uplink BWPs. One or more uplink BWPs can include at least one of an initial uplink BWP and a first active uplink BWP. Uplink BWP configuration parameters can include at least one of the following: configuration parameters for one or more uplink BWPs; one or more uplink BWP IDs for one or more uplink BWPs; PUSCH parameters common to the UE's BWP in the serving cell; SRS carrier handover 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; uplink grant configuration parameters for one or more configurations of 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.

[0281] 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. SRS carrier switching information can be used to configure SRS carrier switching when the PUSCH is not configured, as well as PUSCH-independent SRS power control. Power control configuration parameters may include at least one of PUSCH power control configuration parameters, PUCCH power configuration control parameters, and SRS power control parameters.

[0282] A UE-RRC layer in an RRC inactive or idle state can receive an RRC rejection message in response to an RRC setup request message or an RRC recovery request message. The RRC rejection message may contain a wait timer. Based on the wait timer, the UE-RRC layer can start timer T302, with the timer value set to the wait timer value. Based on the RRC rejection message, the UE-RRC layer can notify the upper layer (e.g., the UE-NAS layer) about the failure to set up or recover the RRC connection. The UE-RRC layer can reset the MAC and release the default MAC cell group configuration. Based on an RRC rejection received in response to a request from an upper layer, the UE-RRC layer can notify the upper layer (e.g., the NAS layer) that access prohibition applies to all access categories except categories '0' and '2'.

[0283] A UE-RRC layer in an inactive or idle RRC state can receive an RRC rejection message in response to an RRC recovery request message. Based on the RRC rejection message, the UE-RRC layer can discard the current security key. The UE-RRC layer can then re-suspend the RRC connection. If recovery is triggered due to an RNA update, the UE-RRC layer can set the pending RNA update value to true.

[0284] A UE-RRC layer in an inactive or idle RRC state can perform a cell (re)selection procedure while simultaneously executing an RRC procedure to establish an RRC connection. Based on cell selection or cell reselection, the UE-RRC layer can change the cell on which the UE camps and stop the RRC procedure. The UE-RRC layer can notify upper layers (e.g., the NAS layer) of the RRC procedure failure.

[0285] A UE in RRC connection state can detect a connection failure with the base station. A UE in RRC connection state can activate AS security with the base station before detecting the failure. The failure includes at least one of the following: radio link failure (RLF); reconfiguration failure with synchronization; mobility failure from the New Radio (NR); integrity check failure indication from a lower layer (e.g., PDCP layer) regarding Signaling Radio Bearer 1 (SRB1) or Signaling Radio Bearer 2 (SRB2); or RRC connection reconfiguration failure.

[0286] A radio link failure can be a radio link failure in the primary cell of the base station. The base station can send a synchronized reconfiguration to a UE in an RRC-connected state in an RRC message. The synchronized reconfiguration can include a reconfiguration timer (e.g., T304). Based on the received synchronized reconfiguration, the UE can 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 can send mobility information from an NR command message to a UE in an RRC-connected state. Based on the received mobility information from the NR command message, the UE can perform a handover from the NR to the cell using another RAT (e.g., E-UTRA). The UE can determine a mobility failure from the NR based on at least one of the following conditions: if the UE fails to establish a connection to the target radio access technology; or if the UE does not meet any part of the configuration included in the mobility information from the NR command message; or if there is a protocol error in the inter-RAT information included in the mobility information from the NR message.

[0287] Based on the detected failure, a UE in RRC connection state can initiate an RRC connection reconstruction procedure. Upon initiating the RRC connection reconstruction procedure, the UE can start timer T311, suspend all radio bearers except SRB0, and reset the MAC (layer). Based on initiating the RRC connection reconstruction procedure, a UE in RRC connection state can release the MCG SCell, release special cell (SpCell) configuration parameters, and release Multi-Radio Dual Connectivity (MR-DC) related configuration parameters. For example, based on initiating the RRC connection reconstruction procedure, the UE can release the primary cell group configuration parameters.

[0288] Based on the RRC connection re-establishment procedure, a UE in RRC connected state can execute a cell selection procedure. Based on the cell selection procedure, the UE can select a cell based on whether the cell's signal quality exceeds a threshold. The UE can determine whether the selected cell exceeds the threshold based on the cell selection procedure. 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.

[0289] Based on the selection of a suitable cell, a UE in RRC connection state can stop timer 311 and start timer T301. Based on the selection of a suitable cell, a UE in RRC connection state can stop timer T390, which disables all access categories. Based on stopping timer T390, a UE in RRC connection state can consider mitigating the disabling of all access categories for a specific cell. Based on the selected cell, a UE in RRC connection state can apply the default L1 parameter values ​​(excluding those provided in SIB1), apply the default MAC cell group configuration, apply the CCCH configuration, apply the timer alignment timer in SIB1, and initiate the transmission of an RRC reconstruction request message.

[0290] A UE in RRC connected state can stop timer T301 upon receiving an RRC response message in response to an RRC rebuild request message. The RRC response message may include at least one of an RRC rebuild message, an RRC setting message, or an RRC rebuild rejection message. A UE in RRC connected state can also stop timer T301 when the selected cell becomes unsuitable.

[0291] Based on the cell selection procedure triggered by the RRC connection reconstruction procedure, a UE in RRC connected state can select an inter-RAT cell. Based on the selection of an inter-RAT cell, a UE in RRC connected state (UE-AS layer) can transition to RRCIDLE state and can provide the release reason 'RRC connection failure' to the upper layer (UE-NAS layer).

[0292] Based on the transmission of the RRC Reconstruction Request message, a UE in RRC connected state can send an RRC Reconstruction Request message. The RRC Reconstruction Request message may include at least one of the following: the C-RNTI used in the source PCell, the Physical Cell Identifier (PCI) of the source PCell, a short MAC-I, or a reconstruction reason. The reconstruction reason may include at least one of reconfiguration failure, handover failure, or other failures.

[0293] Based on the transmission of the RRC Reconstruction Request Message, a UE (RRC layer) in RRC connected state can reconstruct the PDCP of SRB1, reconstruct the RLC of SRB1, apply the default SRB configuration of SRB1, configure the lower layer (PDCP layer) to suspend the integrity protection and encryption of SRB1, resume SRB1, and submit the RRC Reconstruction Request Message to the lower layer (PDCP layer) for transmission. Based on submitting the RRC Reconstruction Request Message to the lower layer, the UE in RRC connected state can send the RRC Reconstruction Request Message to the target base station via the cell selected based on the cell selection procedure, where the target base station may or may not be the source base station.

[0294] Based on the expiration of timer T311 or T301, the UE (UE-AS layer) can transition to the RRC idle state and provide the release reason 'RRC connection failure' to the upper layer of the UE (UE-NAS layer).

[0295] Based on the received release reason "RRC connection failure", when the UE has no pending signaling and user data, the UE in the RRC idle state (UE-NAS layer) can execute the NAS signaling connection restoration procedure. Based on executing the NAS signaling connection restoration procedure, the UE in the RRC idle state can initiate the registration procedure by sending a registration request message to the AMF.

[0296] Based on the received release reason "RRC connection failure", when the UE has pending signaling or pending user data, the UE (UE-NAS layer) in the RRC idle state can execute the service request procedure by sending a service request message to the AMF.

[0297] Upon receiving an RRC reconstruction request message, the target base station can check whether the UE context is locally available. If the UE context is not locally available, the target base station can perform a UE context retrieval procedure by sending a UE context retrieval request message to the UE's source base station (the last serving base station).

[0298] For the RRC connection re-establishment procedure, the UE context request message may contain at least one of the following: UE context ID, integrity protection parameters, or 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 the PCI of the source PCell (the last serving PCell). The integrity protection parameters for the RRC re-establishment procedure may be short MAC-I. The new cell identifier may be an identifier of the target cell, where the target cell is the cell that has already requested to re-establish the RRC connection. The new cell identifier is the cell identifier in the system information block (e.g., SIB1) of the target cell (e.g., the selected cell).

[0299] For the RRC connection re-establishment procedure, based on the received UE Context Retrieval Request message, the source base station can examine the UE Context Retrieval Request message. If the source base station can identify the UE context using the UE context ID and successfully authenticate the UE using the integrity protection contained in the UE Context Retrieval Request message, and decides to provide the UE context to the target base station, then the source base station can respond to the target base station with a UE Context Retrieval Response message. If the source base station cannot identify the UE context using the UE context ID, or if the integrity protection contained in the UE Context Retrieval Request message is not valid, then the source base station can respond to the target base station with a UE Context Retrieval Failure message.

[0300] For the RRC connection re-establishment procedure, the UE context response message may contain at least one of the following: the target base station's Xn Application Protocol (XnAP) ID, the source base station's XnAP ID, a globally unique AMF identifier (GUAMI), or UE context information (e.g., UE context information retrieval UE context response). UE context information may include at least one of the following: NG-C UE-associated signaling reference, UE security capabilities, AS security information, UE aggregated maximum bit rate, a list of PDU sessions to be set, RRC context, a mobility restriction list, or an index to RAT / frequency selection priority. The NG-C UE-associated signaling reference may be the NG Application Protocol ID assigned at the UE's AMF on the NG-C connection with the source base station. AS security information may include the base station's security key (KgNB) and next-hop link count (NCC) value. The list of PDU sessions to be set may include PDU session resource information used at the UE context in the source base station. PDU session resource information may include the PDU session ID, PDU session resource aggregated maximum bit rate, security indication, PDU session type, or a list of QoS flows to be set. Security indications may include user plane integrity protection indications and confidentiality protection indications, which respectively indicate the requirements for user plane (UP) integrity protection and encryption for the corresponding PDU session. Security indications may also include indications of whether to apply UP integrity protection to the PDU session, whether to apply UP encryption to the PDU session, and at least one of the following: the maximum integrity protection data rate value (uplink and downlink) per UE for the integrity protection 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 configured may contain at least one of the following: QoS flow identifier, QoS flow level QoS parameter (QoS parameter to be applied to the QoS flow), or bearer identifier.

[0301] For the RRC connection reconstruction procedure, the UE context failure message can at least contain the XnAP ID of the target base station and the cause value.

[0302] For the RRC connection reconstruction procedure, based on the received UE context retrieval response message, the target base station can send an RRC reconstruction message to the UE. The RRC reconstruction message may contain at least the Network Hop Link Count (NCC) value.

[0303] Upon receiving an RRC reconstruction message, the UE can derive a new security key (KgNB) for the base station based on at least one of the current KgNB or next-hop (NH) parameters associated with the NCC value. Based on the new security key and the previously configured integrity protection algorithm, the UE can derive a security key (KRRCint) for RRC signaling integrity protection and a security key (KUPint) for user plane (UP) data integrity protection. Based on the new security key and the previously configured encryption algorithm, the UE can derive a security key (KRRCenc) for encrypting RRC signaling and a security key (KUPenc) for encrypting user plane (UP) data. Based on KRRCint and the previously configured integrity protection algorithm, the UE can verify the integrity protection of the RRC reconstruction message. If verification fails, the UE (UE-AS layer) can enter the RRC IDLE state and provide the release reason "RRC connection failure" to the UE's upper layer (UE-NAS layer). Based on successful verification, the UE can be configured to restore the integrity protection of SRB1 based on the previously configured integrity protection algorithm and KRRCint, and to restore the encryption of SRB1 based on the previously configured encryption algorithm and KRRCenc. The UE can then send an RRC reconstruction complete message to the target base station.

[0304] Based on the received UE context retrieval failure message, the target base station can send an RRC release message to the UE. For example, based on the UE context retrieval failure message including an RRC release message, the target base station can send an RRC release message to the UE. Based on the received UE context retrieval failure message, the target base station can send an RRC set message or an RRC reject message. Based on the received UE context retrieval failure message, the target base station may choose not to send any response message to the UE.

[0305] Figure 17 An example of an RRC connection reconstruction procedure is shown. A UE in an RRC connected state can send and receive data to / from a first base station (e.g., a source base station) via a cell, where the cell includes the primary cell (PCell) of the first base station. The UE can detect a connection failure with the first base station. Based on this failure, the UE can initiate an RRC reconstruction procedure.

[0306] exist Figure 17In the example, based on initiating the RRC connection re-establishment procedure, the UE can start timer T311 to suspend all radio bearers except SRB0 and / or reset the MAC (layer). Based on initiating the RRC connection re-establishment procedure, the UE can release the MCG SCell, release the special cell (SpCell) configuration parameters and the multiple radio dual connectivity (MR-DC) related configuration parameters. Based on initiating the RRC connection re-establishment procedure, the UE can perform a cell selection procedure. Based on the cell selection procedure, the UE can select cell 2 of the second base station (e.g., the target base station), where cell 2 is a suitable cell. Based on selecting a suitable cell, the UE can stop timer T311 and start timer T301. Based on selecting a suitable cell, if one or more disable timers T309 are running, the UE can stop one or more disable timers T309 for all access categories. Based on stopping one or more disable timers T309, the UE can consider mitigating the disable for all access categories for that cell. Based on cell selection, the UE can apply default L1 parameter values ​​other than those provided in SIB1, apply default MAC cell group configuration, apply CCCH configuration, apply timer alignment timer in SIB1, and initiate the transmission of RRC reconstruction request message.

[0307] exist Figure 17 In the example, the RRC reconstruction message may contain at least one of the following: the C-RNTI used in the source PCell (e.g., cell 1), the physical cell identifier (PCI) of the source PCell, a short MAC-I, or a reconstruction reason. Based on the transmission of the Initiate RRC Reconstruction Request message, the UE (RRC layer) can reconstruct the PDCP of SRB1, reconstruct the RLC of SRB1, apply the default SRB configuration of SRB1, configure the lower layer (PDCP layer) to suspend the integrity protection and encryption of SRB1, resume SRB1, and submit the RRC reconstruction request message to the lower layer (PDCP layer) for transmission. Based on the transmission of the Initiate RRC Reconstruction Request message, the UE can send the RRC reconstruction request message to the second base station via cell 2.

[0308] exist Figure 17In the example, based on receiving an RRC reconstruction request message, the second base station can check whether the UE's UE context is locally available. If the UE context is not locally available, the second base station can perform a UE context retrieval procedure by sending a UE context retrieval request message to the UE's source base station. The UE context retrieval request message can include at least one of the following: UE context ID; integrity protection parameters; or a new cell identifier. The UE context ID can include at least one of the following: a C-RNTI containing the RRC reconstruction request message; and the PCI of the source PCell (the last serving PCell). The integrity protection parameters of the RRC reconstruction procedure can be a short MAC-I. The new cell identifier can be the identifier of the target cell, where the target cell is the cell that has requested to rebuild the RRC connection. The new cell identifier is the cell identifier in the system information block (e.g., SIB1) of the target cell (e.g., the selected cell).

[0309] exist Figure 17 In the example, based on the received UE Context Retrieval Request Message, the source base station can examine the UE Context Retrieval Request Message. If the source base station successfully identifies the UE context using C-RNTI and successfully verifies the UE using Short MAC-I, and decides to provide the UE context to the second base station, the source base station can respond to the second base station using a UE Context Retrieval Response Message. The UE Context Retrieval Response Message may include at least GUAMI or UE context information. Based on the received UE Context Retrieval Response Message, the second base station can send an RRC Reconstruction Message to the UE. The RRC Reconstruction Message may contain a Network Hop Link Count (NCC) value.

[0310] exist Figure 17 In the example, based on receiving an RRC reconstruction message, the UE can derive a new security key (KgNB) for the base station based on at least one of the current KgNB or next-hop (NH) parameters associated with the NCC value. Based on the new security key (KgNB) and the previously configured security algorithm, the UE can derive security keys for integrity protection and encryption of RRC signaling (e.g., KRRCint and KRRCenc, respectively) and security keys for integrity protection and encryption of user plane (UP) data (e.g., KUPint and KUPenc, respectively). Based on the integrity protection security key (KRRCint) of the RRC signaling, the UE can verify the integrity protection of the RRC reconstruction message. Based on successful verification, the UE can be configured to restore integrity protection for one or more bearers (e.g., signaling radio bearers or RRC messages) based on the previously configured integrity protection algorithm and KRRCint, and configured to restore encryption for one or more bearers based on the previously configured encryption algorithm and KRRCenc.

[0311] exist Figure 17 In the example, the second base station can send a first RRC reconfiguration message. The first RRC reconfiguration message may include SpCell configuration parameters. Based on receiving the SpCell configuration parameters, the UE can initiate data transmission and reception to / from the second base station. The UE can 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 can determine the configuration of the SCell and / or secondary cell group (e.g., SCG or PSCell). Based on this determination, the second base station can 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 can transmit and receive data via the SCell and / or SCG.

[0312] exist Figure 17 In the example, the RRC reconfiguration message may contain at least one of the cell group configuration parameters of the MCG and / or SCG, radio bearer configuration parameters, or AS security key parameters.

[0313] The base station can 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 can also be used to release the UE's RRC connection and redirect the UE to another frequency. The base station can send an RRC release message to the UE including pause configuration parameters. Based on the RRC release message, the UE can pause the RRC connection. The UE can transition its RRC state to an RRC inactive state or an RRC idle state. The pause configuration parameters can include at least one of the following: a recovery identifier, RNA configuration, RAN paging loop, or network hop link count (NCC) value, where the RNA configuration can include RNA notification area information or a periodic RNA update timer value (e.g., a T380 value). When the UE is in an RRC inactive state, the base station can use a recovery identifier (e.g., an inactive RNTI (I-RNTI)) to identify the UE context.

[0314] If the base station has a new and unused {NCC, next-hop (NH)} pair, the base station can include the NCC in the pause configuration parameters. Otherwise, the base station can include the same NCC associated with the current KgNB in ​​the pause configuration parameters. The NCC is used for AS security. After sending an RRC release message to the UE including the pause configuration parameters, the base station can delete the current AS key (e.g., KRRCenc, KUPenc) and KUPint, but can retain the current AS key KRRCint. If the sent NCC value is new and belongs to an unused {NCC, NH} pair, the base station can save the {NCC, NH} pair in the current UE AS security context and can delete the current AS key KgNB. If the sent NCC value is equal to the NCC value associated with the current KgNB, the base station can retain the current AS key KgNB and the NCC. The base station can store the sent recovery identifier along with the current UE context, which includes the remainder of the AS security context.

[0315] Upon receiving an RRC release message containing pause configuration parameters from the base station, the UE can verify the integrity of the received RRC release message by checking the PDCP MAC-I. If the verification is successful, the UE can obtain the received NCC value and save it as a stored NCC with the current UE context. The UE can delete the current AS keys KRRCenc, KUPenc, and KUPint, but retain the current AS key KRRCint. If the stored NCC value is different from the NCC value associated with the current KgNB, the UE can delete the current AS key KgNB. If the stored NCC is equal to the NCC value associated with the current KgNB, the UE will retain the current AS key KgNB. The UE can store the received recovery identifier along with the current UE context, including the rest of the AS security context, for use in the next state transition.

[0316] Upon receiving an RRC release message containing pause configuration parameters, the UE can reset the MAC, release the default MAC cell group configuration, and rebuild the RLC entity for one or more bearers. Based on the received RRC release message including pause configuration parameters, the UE can store current configuration parameters and the current security key in the UE inactive AS context. For example, the UE can store several current configuration parameters. These stored parameters may include Robust Header Compression (ROHC) status, Quality of Service (QoS) flow-to-DRB mapping rules, the C-RNTI used in the source PCell, the global cell identifier and physical cell identifier of the source PCell, and all other parameters configured except for those in the synchronized reconfiguration and serving cell configuration common parameters in the SIB. The stored security key may include at least one of KgNB and KRRCint. The serving cell configuration common parameters in the SIB can be used to configure cell-specific parameters of the UE's serving cell in SIB1. Based on receiving an RRC release message including pause configuration parameters, the UE can pause all SRBs and DRBs except SRB0. Upon receiving an RRC release message that includes pause configuration parameters, the UE can start timer T380, enter the RRC inactive state, and execute the cell selection procedure.

[0317] A UE in an RRC inactive state can initiate an RRC connection restoration procedure. For example, a UE in an RRC inactive state can initiate an RRC connection restoration procedure if it has data or signaling to transmit or receive RAN paging messages. Based on initiating the RRC connection restoration procedure, the UE can select the access class based on the triggering conditions of the RRC connection restoration procedure and execute a unified access control procedure based on the access class. Based on the unified access control procedure, the UE can treat the access attempt of the RRC connection restoration procedure as permitted. Based on treating the access attempt as permitted, the UE can apply the default L1 parameter values ​​as specified in the corresponding physical layer specification, in addition to the parameters for which values ​​are provided in SIB1, apply the default SRB1 configuration, 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 the transmission of an RRC restoration request message.

[0318] Based on the transmission of the RRC recovery request message, the UE can configure the content of the RRC recovery request message. The RRC recovery request message may include at least one of the following: recovery identifier, recovery MAC-I, or recovery reason. The recovery reason may include at least one of the following: emergency, high priority access, MT access, MO signaling, MO data, MO voice call, MO SMS, RAN update, MPS priority access, and MCS priority access.

[0319] Based on 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 stored security keys from the (stored) UE inactive AS context. Configuration parameters may include at least one of the following: the C-RNTI used in the source PCell, the global cell identifier and physical cell identifier of the source PCell, and all other parameters configured except those in the synchronized reconfiguration and serving cell configuration common parameters in the SIB. Based on the current (restored) KgNB or next-hop (NH) parameters associated with the stored NCC value, the UE can derive the base station's new key (KgNB). Based on the base station's new key, the UE can derive the security keys for integrity protection and encryption of RRC signaling (e.g., KRRCenc and KRRCint, respectively) and the security keys for integrity protection and encryption of user plane data (e.g., KUPint and KUPenc, respectively). Based on the configured algorithm and KRRCint and KUPint, the UE can configure a lower layer (e.g., the PDCP layer) to apply integrity protection to all radio bearers except SRB0. Based on the configured algorithm and KRRCenc and KUPenc, the UE can configure a lower layer (e.g., the PDCP layer) to apply encryption to all radio bearers except SRB0.

[0320] Based on the transmission of the RRC recovery request message, the UE can rebuild the PDCP entity for one or more bearers, restore one or more bearers, and submit the RRC recovery request message to a lower layer, wherein the lower layer may include at least one of the PDCP layer, RLC layer, MAC layer, or physical (PHY) layer.

[0321] The target base station can receive RRC recovery request messages. Based on the received RRC recovery request message, the target base station can check whether the UE context is locally available. If the UE context is not locally available, the target base station can perform a UE context retrieval procedure by sending a UE context retrieval request message to the UE's source base station (the last serving base station). The UE context retrieval request message may contain at least one of the following: UE context ID, integrity protection parameters, new cell identifier, or recovery reason, where the recovery reason is included in the RRC recovery request message.

[0322] For the RRC connection recovery procedure, based on the received Retrieve UE Context Request message, the source base station can examine the message. If the source base station can identify the UE context using the UE context ID and successfully authenticate the UE using the integrity protection contained in the Retrieve UE Context Request message, and decides to provide the UE context to the target base station, the source base station can 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 contained in the Retrieve UE Context Request message is not valid, or if the source base station decides not to provide the UE context to the target base station, the source base station can respond to the target base station with a Retrieve UE Context Failure message.

[0323] For the RRC connection recovery procedure, the UE context failure message can contain at least the target base station's XnAPID, RRC release message, or cause value.

[0324] For the RRC connection restoration procedure, based on the received UE context retrieval response message, the target base station can send an RRC restoration message to the UE. The RRC restoration message may include at least one of the following: radio bearer configuration parameters, cell group configuration parameters of MCG and / or SCG, measurement configuration parameters, or sk counter, wherein the sk counter is used to derive the secondary base station's security key based on the KgNB.

[0325] Based on the received UE context retrieval failure message, the target base station can send an RRC release message to the UE. For example, based on the UE context retrieval failure message including an RRC release message, the target base station can send an RRC release message to the UE. Based on the received UE context retrieval failure message, the target base station can send an RRC set message or an RRC reject message. Based on the received UE context retrieval failure message, the target base station may choose not to send any response message to the UE.

[0326] Upon receiving the RRC recovery message, the UE can stop timers T319 and T380. Based on the received RRC recovery message, the UE can restore the primary cell group configuration parameters, secondary cell group configuration parameters, and PDCP configuration parameters in the UE inactive AS context. Based on the restored primary cell group configuration parameters and / or secondary cell group configuration parameters, the UE can configure the SCells of the MCG and / or SCG by configuring lower layers, treating the restored MCG and / or SCG SCells as deactivated, discarding the UE inactive AS context, and releasing the paused configuration parameters.

[0327] Based on the cell group configuration parameters received in the RRC recovery message, the UE can perform cell group configuration for the MCG and / or SCG. 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 update the security key of the secondary base station.

[0328] The UE can remain CM-CONNECTED and move within the area configured by the base station without notifying the base station when the UE is in an RRC inactive state in that area (RNA). In the RRC inactive state, the last serving base station can maintain the UE context and the NG connection associated with the UE in the serving AMF and UPF. Based on downlink data received from the UPF or downlink UE-associated signaling received from the AMF when the UE is in an RRC inactive state, the last serving base station can perform paging in the cell corresponding to the RNA, and can send RAN paging to neighboring base stations via the Xn interface if the RNA includes cells of neighboring base stations.

[0329] The AMF (Application Management Function) can provide core network auxiliary information to the base station to assist in determining whether the UE can be sent to an RRC inactive state. Core network auxiliary information may include the registration area configured for the UE, periodic registration update timers, UE identifier index values, UE-specific DRX, an indication of whether the UE is configured with a Mobile-Initiated Connection (MICO) mode via the AMF, or expected UE behavior. The base station can use the UE-specific DRX and UE identifier index value to determine the timing of paging for RAN paging. The base station can use periodic registration update timers to configure periodic RNA update timers (e.g., timer T380). The base station can use expected UE behavior to assist in UE RRC state transition decisions.

[0330] Figure 18 An example of an RRC connection restoration procedure 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 the RRC connected state to an RRC inactive state. Based on this determination, the base station can send an RRC release message containing pause configuration parameters.

[0331] exist Figure 18In the example, based on receiving an RRC release message containing pause configuration parameters, the UE can store the current security key (e.g., KgNB and KRRCint keys) and current configuration parameters in the UE inactive AS context. For example, the UE can store several current configuration parameters. The stored (current) configuration parameters can be at least one of the following: Robust Header Compression (ROHC) state; QoS flow-to-DRB mapping rules; C-RNTI used in the source PCell; global cell identifier and physical cell identifier of the source PCell; and all other parameters configured except for those in the synchronized reconfiguration and serving cell configuration common parameters in the SIB. The Robust Header Compression (ROHC) state can include the ROHC state of all PDCP entities (or all bearers), where each PDCP entity (or each bearer) of each bearer can have one ROHC state. The QoS flow-to-DRB mapping rules can be QoS flow-to-DRB mapping rules for all data radio bearers (DRBs), where each DRB can have one QoS flow-to-DRB mapping rule.

[0332] exist Figure 18 In the example, based on receiving an RRC release message containing pause configuration parameters, the UE can pause all SRBs and DRBs except SRB0. Based on receiving the RRC release message containing pause configuration parameters, the UE can start timer T380, enter the RRC inactive state, and execute the cell selection procedure. Based on the cell selection procedure, the UE can select cell 2 of the second base station (target base station). The UE in the RRC inactive state can initiate an RRC connection restoration procedure. The UE can execute a unified access control procedure. Based on the unified access control procedure, the UE can treat the access attempt of the RRC connection restoration procedure as permitted. The UE can apply the default L1 parameter values ​​as specified in the corresponding physical layer specification, in addition to the parameters for which values ​​are provided in SIB1, apply the default SRB1 configuration, 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 the transmission of an RRC restoration request message.

[0333] exist Figure 18In the example, based on the transmission of the RRC recovery request message, the UE can recover the stored configuration parameters and stored security keys from the (stored) UE inactive AS context. For example, in addition to 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 stored security keys (e.g., KgNB and KRRCint) from the stored UE inactive AS context. Based on the current (recovered) KgNB or next-hop (NH) parameter associated with the stored NCC value, the UE can derive a new key (KgNB) for the base station. Based on the new key for the base station, the UE can derive security keys (e.g., KRRCenc and KRRCint, respectively) for integrity protection and encryption of RRC signaling, as well as security keys (e.g., KUPint and KUPenc, respectively) for integrity protection and encryption of user plane data. Based on the configured algorithm and KRRCint and KUPint, the UE (RRC layer) can configure lower layers (e.g., PDCP layer) to apply integrity protection to all radio bearers except SRB0. Based on the configured algorithm and KRRCenc and KUPenc, the UE can configure lower layers (e.g., the PDCP layer) to apply encryption to all radio bearers except SRB0. For communication between the UE and the base station, integrity protection and / or encryption may be required. Based on integrity protection and / or encryption, the UE is able to transmit and receive data to / from the second base station. The UE can use the restored configuration parameters to transmit and receive data to / from the second base station.

[0334] exist Figure 18 In the example, based on the transmission of the RRC recovery request message, the UE can reconstruct the PDCP entity for one or more bearers, recover one or more bearers, and submit the RRC recovery request message to the lower layer. Upon receiving the RRC recovery request message, the second base station can check whether the UE's UE context is locally available. If the UE context is not locally available, the second base station can perform a UE context retrieval procedure by sending a UE context retrieval request message to the UE's first base station (the last serving base station). The UE context retrieval request message can contain at least one of the following: a recovery identifier; a recovery MAC-I; or a recovery reason.

[0335] exist Figure 18In the example, based on receiving the UE Context Retrieval Request message, the first base station can examine the UE Context Retrieval Request message. If the first base station can identify the UE context using the UE context ID and successfully verify the UE using the restored MAC-I, and decides to provide the UE context to the second base station, the first base station can respond to the second base station with a UE Context Retrieval Response message. Based on receiving the UE Context Retrieval Response message, the second base station can send an RRC Restore message to the UE. Based on receiving the RRC Restore message, the UE can 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 can configure the SCell of the MCG and / or SCG by configuring the lower layer to treat the restored MCG and / or SCG SCell as inactive, discard the UE inactive AS context, and release the pause configuration parameters. The UE can transmit and receive data via the SCell and / or SCG.

[0336] The base station can send an RRC release message to the UE to release the UE's RRC connection. Based on the RRC release message, the UE can release established radio bearers and all radio resources.

[0337] The base station can send an RRC release message to the UE to suspend the RRC connection. Based on the RRC release message, the UE can suspend all radio bearers except for Signaling Radio Bearer 0 (SRB0). The RRC release message may include suspension configuration parameters. The suspension configuration parameters may include the next-hop link count (NCC) and a recovery identifier (e.g., ID or identifier).

[0338] The base station can send an RRC release message to change a UE in the RRC connected state to the RRC idle state; or change a UE in the RRC connected state to the RRC inactive state; or change a UE in the RRC inactive state back to the RRC inactive state when the UE attempts to recover; or change a UE in the RRC inactive state to the RRC idle state when the UE attempts to recover.

[0339] The base station can send an RRC release message to redirect the UE to another frequency.

[0340] The UE can receive an RRC release message from the base station of the serving cell (or PCell). Based on the RRC release message, the UE can perform UE actions in response to the RRC release message from the base station. The UE can delay its actions for a period of time (e.g., 60 ms) from the moment the RRC release message is received or upon successful confirmation of receipt. The UE can send a HARQ acknowledgment to the base station to confirm the RRC release message. Based on the RLC Protocol Data Unit (PDU) containing the RRC release message and the RLC PDU containing polling bits, the UE can send an RLC message (e.g., a status report) to the base station to confirm the RRC release message.

[0341] A UE action in response to an RRC release message from a base station may include at least one of the following: suspending the RRC connection; releasing the RRC connection; cell (re)selection procedure; and / or idle / inactive measurement.

[0342] The RRC release message from the base station may contain pause configuration parameters. Based on the pause configuration parameters, the UE may suspend the RRC connection. Suspending the RRC connection may include at least one of the following: Media Access Control (MAC) reset (or MAC reset); release the default MAC cell group configuration; rebuild the RLC entity for one or more radio bearers; store the current configuration parameters and the current security key; suspend one or more bearers, wherein the bearer contains signaling radio bearers and data radio bearers; and / or change the RRC idle state or RRC inactive state.

[0343] For example, the pause configuration parameters may also include RNA configuration parameters. Based on the RNA configuration parameters, the UE can transition to an RRC inactive state. For example, if the pause configuration parameters do not include RNA configuration parameters, the UE can transition to an RRC idle state. For example, an RRC release message that includes pause configuration parameters may include an indication to transition to an RRC inactive state. Based on this indication, the UE can transition to an RRC inactive state. For example, if the RRC release message does not include this indication, the UE can transition to an RRC idle state.

[0344] Based on a MAC reset, the UE may perform at least one of the following: stop all timers running in the UE-MAC layer; treat all time-aligned timers as expired; set the New Data Indicator (NDI) for all uplink HARQ procedures to a value of 0; stop ongoing RACH procedures; discard contention-free random access resources that are explicitly signaled (if any); flush the Msg 3 buffer; cancel triggered scheduling request procedures; cancel triggered buffer status reporting procedures; cancel triggered power headroom reporting procedures; flush the soft buffers for all DL HARQ procedures; treat the next received transmission of the TB as the first transmission for each DL HARQ procedure; and / or release the temporary C-RNTI.

[0345] Based on treating the time alignment timers as expired, the UE may perform at least one of the following: refresh all HARQ buffers for all serving cells; notify the RRC to release PUCCH for all serving cells, if configured; notify the 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 runtime alignment timers to have expired.

[0346] The default MAC cell group configuration parameters may include the base station's cell group buffer state report (BSR) configuration parameters (e.g., BSR timer) and the base station's cell group power headroom report (PHR) configuration parameters (e.g., PHR timer or PHR transmission power factor change parameters).

[0347] Reconstructing an RLC entity may include at least one of the following: discarding all RLC SDUs, RLC SDU segments, and RLC PDUs, if any; stopping and resetting all timers of the RLC entity; and resetting all state variables of the RLC entity to their initial values.

[0348] The RRC release message from the base station may not contain pause configuration parameters. Based on the absence of pause configuration parameters in the RRC message, the UE can release the RRC connection. Releasing the RRC connection may include at least one of the following: MAC reset (or MAC reset); discarding stored configuration parameters and stored security keys (or discarding stored UE inactive AS context); releasing pause configuration parameters; releasing all radio resources, including releasing RLC entities, MAC configurations, and associated PDCP entities and SDAPs for all established radio bearers; and / or transitioning to an RRC idle state.

[0349] RRC release messages can include RRC early data completion messages.

[0350] The layers can be associated with the Open Systems Interconnection (OSI) model, which describes the functionality of computer networking. In the OSI model, Layer 1 may correspond to the bottom layer, with higher layers on top of the bottom layer. Layer 1 may correspond to the physical layer, which relates to the physical infrastructure (e.g., cables, optical fibers, and / or radio frequency transceivers) used to transmit signals. In New Radio (NR), Layer 1 may include the Physical Layer (PHY). Layer 2 may correspond to the Data Link Layer. Layer 2 may relate to the physical infrastructure that packages data (e.g., data frames) for transmission between nodes in the network using Layer 1. In NR, Layer 2 may include the Media Access Control (MAC) layer, Radio Link Control (RLC) layer, Packet Data Convergence Layer (PDCP) layer, and Service Data Application Protocol (SDAP) layer.

[0351] Layer 3 may correspond to the network layer. Layer 3 may relate to the routing of data already encapsulated in Layer 2. Layer 3 can handle the prioritization of data and traffic avoidance. In NR, Layer 3 may include the Radio Resource Control (RRC) layer and the Non-Access Layer (NAS) layer. Layers 4 through 7 may correspond to the transport layer, session layer, presentation layer, and application layer. The application layer interacts with end users to provide application-related data. In the example, an end user implementing an application may generate application-related data and initiate the transmission of said information to a target data network (e.g., the Internet, an application server, etc.). Starting at the application layer, each layer in the OSI model can manipulate and / or re-encapsulate information and deliver it to the next layer. At the lowest layer, manipulated and / or re-encapsulated information may be exchanged via physical infrastructure (e.g., electrically, optically, and / or electromagnetically). As it approaches the target data network, the information is decapsulated and provided to increasingly higher layers until it reaches the application layer again in a form available to the target data network (e.g., the same form it was provided by the end user). In response to end users, the data network can reverse-execute this procedure.

[0352] The user plane protocol stack shown in Figure 2 can be a New Radio (NR) protocol stack for the Uu interface between the UE and the gNB. In layer 1 of the UP protocol stack, the UE can implement PHY, and the gNB can also implement PHY. In layer 2 of the UP protocol stack, the UE can implement MAC, RLC, PDCP, and SDAP. The gNB can also implement MAC, RLC, PDCP, and SDAP.

[0353] The control plane protocol stack shown in Figure 2 can be an NR protocol stack used for the Uu interface between the UE and the gNB and / or the N1 interface between the UE and the AMF. In layer 1 of the CP protocol stack, the UE 1901 can implement PHY, and the gNB can also implement PHY. In layer 2 of the CP protocol stack, the UE can implement MAC, RLC, PDCP, RRC, and NAS. The gNB can implement MAC, RLC, PDCP, and RRC. The AMF can implement NAS.

[0354] The NAS shown in Figure 2 can be related to the non-access layer, specifically, communication between the UE and the core network (e.g., AMF). Lower layers can be related to the access layer, such as communication between the UE and the gNB. Messages sent between the UE and the core network can be referred to as NAS messages. In the example, NAS messages can be relayed by the gNB, but the content of the NAS message (e.g., the information elements of the NAS message) may not be visible to the gNB.

[0355] exist Figure 3 In this context, the UE can receive services via a PDU session, which can be a logical connection between the UE and the data network (DN). The UE and the DN can exchange data packets associated with the PDU session. A PDU session may include one or more Quality of Service (QoS) flows. SDAP can perform mapping and / or demapping between the one or more QoS flows and one or more radio bearers (e.g., data radio bearers) of the PDU session. The mapping between QoS flows and data radio bearers can be determined by the gNB in ​​the SDAP and can be notified to the UE (e.g., based on control signaling and / or reflection mapping). For reflection mapping, the gNB's SDAP can tag downlink packets with QoS Flow Indicators (QFIs) and deliver the downlink packets to the UE. The UE can determine the mapping based on the QFI of the downlink packets.

[0356] exist Figure 3 In this context, PDCP can perform header compression and / or decompression. Header compression reduces the amount of data transmitted at the physical layer. PDCP can also perform encryption and / or decryption. Encryption reduces unauthorized decoding of data transmitted at the physical layer (e.g., interception at the air interface) and protects data integrity (e.g., ensuring control messages originating from a designated source). PDCP can perform retransmission of undelivered packets, packet delivery and reordering, packet duplication, and / or identification and removal of duplicate packets. In dual-connectivity scenarios, PDCP can perform splitting the mapping between the radio bearer and the RLC channel.

[0357] exist Figure 3In this context, RLC can perform segmentation and retransmission via Automatic Repeat Request (ARQ). RLC can also remove duplicate data units received from the MAC and MAC separately. RLC can also serve the RLC channel as part of the PDCP.

[0358] exist Figure 3 In the MAC (Macro-MAC) interface, logical channels can be multiplexed and / or demultiplexed. MACs can map logical channels to transport channels. In the example, the UE can multiplex data elements from one or more logical channels into a transport block within the MAC. The UE can use the PHY to transmit the transport block to the gNB. The gNB can use the PHY to receive the transport block and demultiplex the data elements back into the logical channels. The MAC can perform error correction via Hybrid Automatic Repeat Request (HARQ), logical channel prioritization, and / or padding.

[0359] exist Figure 3 In a PHY, the transmission channel can perform mapping to the physical channel. The PHY and PHY can perform digital and analog signal processing functions (e.g., encoding / decoding and modulation / demodulation) for transmitting and receiving information (e.g., transmission via the air interface). The PHY can perform multi-antenna mapping.

[0360] One or more NG-RAN base stations can be split into a Central Unit (CU) and one or more Distributed Units (DUs). A CU can be connected to one or more DUs via an F1 interface. A CU can handle one or more upper layers of the protocol stack, and a DU can handle one or more lower layers of the protocol stack. For example, a CU can handle RRC, PDCP, and SDAP, while a DU can handle RLC, MAC, and PHY. The one or more DUs can be located geographically disparately from the CU and / or from each other. Accordingly, the CU / DU split architecture allows for increased coverage and / or better coordination.

[0361] The central unit may be referred to as the following and / or may be interchanged with the following: base station central unit or central unit of base station or CU or gNB-CU. The distributed unit may be referred to as the following and / or may be interchanged with the following: base station distributed unit or distributed unit of base station or DU or gNB-DU.

[0362] In RRC connected state, a wireless device can measure multiple beams (at least one) of a cell and average the measurement results (power values) to derive cell quality. In doing so, the wireless device can be configured to consider a subset of the detected beams. Filtering can be performed at two different levels: at the physical layer for deriving beam quality, and subsequently at the RRC layer for deriving cell quality from the multiple beams. For both serving and non-serving cells, cell quality from beam measurements can be derived in the same manner. If the base station (e.g., gNB) configures the UE to do this, the measurement report can include measurement results for X optimal beams.

[0363] Layer 1 filtering can be an internal Layer 1 filtering of the input measured at point A. The precision of the filtering depends on the implementation. Measurements can be performed in the physical layer using the implementation (input A and Layer 1 filtering). A is the measurement value (beam-specific sample) within the physical layer. A1 is the measurement value (e.g., beam-specific measurement) reported from Layer 1 to Layer 3 after Layer 1 filtering.

[0364] Layer 1 filtering may introduce a certain level of measurement averaging. How and when the UE precisely performs the required measurements can be specific to the implementation, as long as the output at B meets the performance requirement set. B is the measurement (e.g., cell quality) derived from beam-specific measurements reported to Layer 3 after beam combining / selection. Beam combining / selection is the merging of beam-specific measurements to derive cell quality. The configuration of this module is provided by RRC signaling. The reporting period at B can be equal to one measurement period at A1.

[0365] Layer 3 filtering for cell quality can be performed on the measurement values ​​provided at point B. The configuration of the Layer 3 filter can be provided by RRC signaling. The filtering reporting period at point C can be equal to one measurement period at point B. Layer 3 filtering for cell quality and the relevant parameters used may not introduce any delay in sample availability between B and C. The measurement value at point C, C1, is the input used in event evaluation. C is the measurement value after processing in the Layer 3 filter. The reporting rate is the same as the reporting rate at point B. This measurement value is used as input for one or more evaluations of the reporting criteria. The evaluation of the reporting criteria can check whether an actual measurement report is needed at point D. D is the measurement report information (message) sent on the radio interface. This evaluation can be based on more than one measurement stream at reference point C, for example, to compare between different measurement values. This can be illustrated by inputs C and C1. The UE evaluates the reporting criteria at least each time a new measurement result is reported at points C and C1. This configuration can be provided by RRC signaling (UE measurement value).

[0366] The L3 beam filtering and related parameters used may not introduce any delay in sample availability between E and F. L3 beam filtering is performed on the measurements provided at point A1 (e.g., beam-specific measurements). The beam filter configuration can be provided by RRC signaling. L3 beam filtering can provide K beams. The K beams can correspond to measurements on the SSB, or CSI-RS resources configured by the base station (e.g., gNB) for L3 mobility and detected by the UE at L1. The filtering reporting period at E can be equal to one measurement period at A1. E is the measurement after processing in the beam filter (e.g., beam-specific measurements). The reporting rate can be the same as the reporting rate at point A1. This measurement is used as input for selecting X measurements to be reported. Beam selection for beam reporting can be done by selecting X measurements from the measurements provided at point E. The configuration of this module can be provided by RRC signaling. F is the beam measurement information included in the measurement report transmitted on the radio interface.

[0367] Measurement reports can be characterized by the following: measurement reports include measurement identifiers of associated measurement configurations that triggered the report; cell and beam measurements included in the measurement report are configured by the network; the network can be configured to limit the number of non-serving cells to be reported; cells belonging to a blacklist configured by the network are not used for event assessment and reporting, and conversely, when a whitelist is configured by the network, only cells belonging to the whitelist are used for event assessment and reporting; beam measurements included in the measurement report are configured by the network (beam identifier only, measurement result and beam identifier, or no beam report).

[0368] Intra-frequency adjacent (cell) measurements and inter-frequency adjacent (cell) measurements can be defined as follows: Intra-frequency measurement based on SSB, wherein the measurement is defined as an intra-frequency measurement based on SSB, provided that the center frequency of the SSB of the serving cell is the same as the center frequency of the SSB of the adjacent cell, and the subcarrier spacing of the two SSBs is also the same; Inter-frequency measurement based on SSB, wherein the measurement is defined as an inter-frequency measurement based on SSB, provided that the center frequency of the SSB of the serving cell is different from the center frequency of the SSB of the adjacent cell, or the subcarrier spacing of the two SSBs is different; Intra-frequency measurement based on CSI-RS; and Inter-frequency measurement based on CSI-RS, wherein if the measurement is not an intra-frequency measurement based on CSI-RS, then the measurement is defined as an inter-frequency measurement based on CSI-RS.

[0369] In-frequency measurement based on CSI-RS is defined as a measurement based on CSI-RS within a frequency range, provided that: the subcarrier spacing of the CSI-RS resources configured for measurement on the neighboring cell is the same as the SCS of the CSI-RS resources indicated for measurement on the serving cell; for a 60kHz subcarrier spacing, the CP type of the CSI-RS resources configured for measurement on the neighboring cell is the same as the CP type of the CSI-RS resources indicated for measurement on the serving cell; and the center frequency of the CSI-RS resources configured for measurement on the neighboring cell is the same as the center frequency of the CSI-RS resources indicated for measurement on the serving cell.

[0370] For SSB-based measurements, one measurement object can correspond to one SSB, and the wireless device treats different SSBs as different cells.

[0371] Whether a measurement is non-gap-assisted or gap-assisted depends on the capabilities of the radio device, the active BWP of the radio device, and the current operating frequency. For SSB-based inter-frequency measurements, if the radio device reports measurement gap requirement information, a measurement gap configuration can be provided based on that information. Otherwise, a measurement gap configuration is provided if: the radio device only supports per-radio-device measurement gaps; or if the radio device supports per-FR measurement gaps, and any serving cell in the serving cell is within the same frequency range as the measurement object. For SSB-based intra-frequency measurements, if the radio device reports measurement gap requirement information, a measurement gap configuration can be provided based on that information. Otherwise, a measurement gap configuration is always provided if: any of the BWPs configured by the radio device, other than the initial BWP, does not contain the frequency domain resources of the SSB associated with the initial DL BWP.

[0372] In non-gap-assisted scenarios, wireless devices can perform such measurements without a measurement gap. In gap-assisted scenarios, wireless devices are not considered capable of performing such measurements without a measurement gap.

[0373] In the example, the measurement timing configuration can be used to convey auxiliary information for measurement timing. The measurement timing configuration can include at least one of the following: measurement timing; camp on first SSB; PScell ​​only on first SSB; and CSI-RS configuration. Measurement timing can include frequency and timing; SSB for measurement; and physical cell identifier. Frequency and timing can include at least one of the following: carrier frequency; SSB subcarrier spacing; SSB measurement timing configuration; and SS-RSSI measurement.

[0374] In the example, the CSI-RS configuration may include at least one of the following: CSI-RS subcarrier spacing; CSI-RS cell mobility; and a reference SSB frequency (refSSBfreq). csi-RS-cellmobility may indicate the CSI-RS configuration of the cell that includes this message. The timing of the CSI-RS resources may be based on the SSB indicated by refSSBfreq. csi-RS-subcarrier spacing may indicate the subcarrier spacing of the CSI-RS resources included in csi-RS-cellmobility.

[0375] In the example, *meastiming* can be a list of SMTC information, SSB RSSI measurement information, and associated frequencies (e.g., NR frequencies) exchanged via an X2 interface (e.g., for X2 setup / update, DC configuration setup / update, Xn setup / update, node (e.g., base station) configuration update, or F1 messages between the base station central unit and the base station distributed unit). *physcellid* can be the physical cell identifier of the SSB on the ARFCN, indicated by *arrierfreq* (carrier frequency). *camponfirstSSB* (e.g., indicated as true) can indicate that the SSB indicated in the first *meastiming* instance in the *meastiming* list can be used for camping and PCell configuration. The *meastiming* list can include one or more *meastimings*. *ssb-tomeasure* can be a set of SS blocks to be measured during the SMTC measurement duration.

[0376] In the example, `carrierfreq` and `ssbSubcarrierSpacing` indicate the frequency and subcarrier spacing of the SS block of the cell containing this message, or other SS blocks within the same carrier. `ssb-measurementtimingconfiguration` indicates the SMTC that can be used to search for the SSB of the cell containing the message. `SS-RSSI-measurement` provides the configuration for RSSI measurements that can be performed on the cell containing the message.

[0377] A transmitter (radio transmitter) of a wireless device can be an electronic device that generates radio waves using an antenna. A transmitter can generate radio frequency alternating current applied to an antenna. For example, an antenna can radiate radio waves. The term transmitter can be limited to devices that generate radio waves for communication purposes; or for radio positioning (e.g., radar and navigation transmitters). A transmitter can be a standalone electronic device or a circuit within another electronic device. A transmitter and receiver combined in one unit can be called a transceiver. In technical documents, the term transmitter is often abbreviated as "XMTR" or "TX". Most transmitters are used for radio information communication over a distance. Information can be provided to the transmitter in the form of electronic signals, such as audio (sound) signals from a microphone, video (TV) signals from a camera, or digital signals from a computer in a wireless (network service) device. The transmitter can combine the information signal to be carried with a radio frequency signal that generates radio waves, called a carrier signal. This process can be called modulation. The radio signal from the transmitter can be applied to an antenna, which radiates energy in the form of radio waves. Antennas can be encapsulated inside a housing or attached to the outside of the transmitter, as in portable devices such as cellular phones. The transmitter can be an antenna (group), an antenna panel (group), a MIMO layer (group), or a transmitter (group). Each antenna panel can have one or more antenna elements. For example, a first one or more antennas (or a first one or more antenna panels, or a first one or more MIMO layers) can be a first transmitter. A second one or more antennas (or a second one or more antenna panels, or a first one or more MIMO layers) can be a second transmitter. For example, a base station and / or wireless device can have multiple antennas. Many antenna elements can be assembled into multiple antennas. Multi-panel MIMO (layers) can be used for wireless communication between a base station and a wireless network.

[0378] In the example, the wireless device can receive a measurement configuration from a base station. The measurement configuration may instruct the wireless device on one or more frequencies and / or one or more cells on which to perform measurements. Based on the measurement configuration, the wireless device can perform measurements on the frequencies and / or cells indicated by the measurement configuration.

[0379] Wireless devices can perform measurements using a measurement configuration, for example, during a measurement gap indicated by the measurement configuration. In this disclosure, a measurement gap may be referred to as and / or interchangeably with the following: gap, interval (time period and / or interval), measurement gap (time period and / or interval), etc.

[0380] The measurement gap can be the duration of a wireless channel condition that a wireless device can measure associated with a cell of a specific base station (e.g., a network) and / or configured at a specific frequency using a specific RAT. For example, the specific base station (e.g., the network) can be the same base station (e.g., the same network) that the wireless device maintains a connection with (e.g., an RRC connection). For example, the specific base station (e.g., the network) can be different from the base station (e.g., the network) that the wireless device maintains a connection with (e.g., an RRC connection). For example, the specific RAT can be Wi-Fi, LTE, NR, etc. For example, the specific RAT can be the same RAT that the wireless device uses to maintain a connection (e.g., an RRC connection) with a first base station (e.g., the network). For example, the specific RAT can be different from the RAT that the wireless device uses to maintain a connection (e.g., an RRC connection) with a first base station (e.g., the network).

[0381] For example, a wireless device may maintain a connection (e.g., RRC connection) with the current base station (e.g., a network) during measurement intervals. A wireless device may not communicate with the current base station during measurement intervals. For example, a wireless device may not transmit and / or receive data (e.g., messages, packets, SDUs, PDUs, and / or transport blocks) and / or reference signals (e.g., SRS and / or CSI-RS) from the current base station during measurement intervals. A wireless device may not monitor the downlink control channel configured by the current base station during measurement intervals. A current base station may not communicate with the wireless device during measurement intervals. For example, a current base station may not transmit and / or receive data (e.g., messages, packets, SDUs, PDUs, and / or transport blocks) and / or reference signals (e.g., SRS and / or CSI-RS) from the wireless device during measurement intervals. A current base station may not monitor the uplink control channel configured for the wireless device during measurement intervals.

[0382] For example, a wireless device can communicate with a second device (e.g., a second wireless device, a second base station, a second network, etc.) during measurement intervals while maintaining a connection (e.g., an RRC connection) with the current base station (e.g., a network). For example, communication with the second device can include monitoring the downlink channels of the second device (e.g., paging channels, PDCCH, PDSCH, SSB, CSI-RS, etc.) during measurement intervals. For example, communication with the second device can include receiving signals and / or data from the second device via downlink channels (e.g., PDCCH, PDSCH, SSB, CSI-RS, etc.) during measurement intervals. For example, communication with the second device can include receiving signals (e.g., reference signals, such as SSB, CSI-RS) and / or data (e.g., messages, packets, SDUs, PDUs, and / or transport blocks) from the second device via downlink channels (e.g., PDCCH, PDSCH, SSB, CSI-RS, etc.) during measurement intervals. For example, communication with the second device may include transmitting signals (e.g., reference signals, such as SRS, preambles, etc.) and / or data (e.g., messages, packets, SDUs, PDUs, Msg3, MsgB, and / or transport blocks) to the second device via uplink channels (e.g., PRACH, PUSCH, PUCCH, and / or SRS, etc.) during measurement intervals.

[0383] During measurement intervals, the wireless device may not communicate with the current base station. For example, the wireless device may not transmit and / or receive data (e.g., packets, SDUs, PDUs, and / or transport blocks) and / or reference signals (e.g., SRS and / or CSI-RS) from the current base station. The wireless device may not monitor the downlink control channel configured by the current base station during measurement intervals. The current base station may not communicate with the wireless device during measurement intervals. For example, the current base station may not transmit and / or receive data (e.g., packets, SDUs, PDUs, and / or transport blocks) and / or reference signals (e.g., SRS and / or CSI-RS) from the wireless device during measurement intervals. The current base station may not monitor the uplink control channel configured for the wireless device during measurement intervals.

[0384] In the example, the wireless device can receive a measurement configuration from a base station. The measurement configuration may include a measurement gap configuration. The measurement gap configuration may include one or more configuration parameters. One or more configuration parameters of the measurement gap may indicate the time period during which the wireless device can perform measurements. One or more configuration parameters may indicate one or more measurement gaps. Each of the one or more measurement gaps may be associated with one or more frequency ranges in which the wireless device performs one or more measurements using one or more configuration parameters. For example, each of the one or more measurement gaps may be based on a frequency or frequency range (e.g., FR1, FR2, and / or FR3) and / or the wireless device / UE. For example, a measurement gap based on a frequency range (e.g., FR1, FR2, and / or FR3) may be applied to measurements performed by the wireless device within the corresponding frequency range. A measurement gap based on the wireless device / UE may be applied to measurements performed by the wireless device at one or more (e.g., all) frequencies (e.g., FR1, FR2, and / or FR3). Each measurement gap may include at least one of the following: a measurement gap repetition period (mgrp) value, a measurement gap length (mgl) value, a gap offset value, and a serving cell identifier. The mgrp value may indicate the measurement gap repetition period (ms) of the measurement gap. The mgl value indicates the measurement gap length (in milliseconds). The gap offset value can be indicated by mgrp in the mgrp field to indicate the gap offset of the gap pattern.

[0385] During measurement gaps, the wireless device may not transmit data to the base station. For example, the data may include at least one of the following: HARQ feedback, SR and CSI, SRS report, and UL-SCH. During measurement gaps, the wireless device may not monitor the downlink channel (e.g., PDCCH) of the base station's serving cell. The wireless device may not receive downlink data on the DL-SCH.

[0386] In the example, during the measurement gap period / time, the base station may not transmit downlink data to the base station. For example, downlink data may include at least one of the following: data on DCI, MAC CE, and DL-SCH. During the measurement gap, the base station (serving cell) may not monitor the uplink channels (e.g., PUCCH / PUSCH) of the radio equipment. The base station may not receive (uplink data) on UL-SCH.

[0387] A wireless device can receive one or more messages (e.g., RRC messages) from a base station, including configuration parameters for multiple cells (e.g., primary cell, secondary cell). The wireless device can communicate with at least one base station (e.g., two or more base stations in dual connectivity) via multiple cells. One or more messages (e.g., as part of the configuration parameters) can include parameters for configuring the wireless device at the physical layer, MAC layer, RLC layer, PCDP layer, SDAP layer, and RRC layer. For example, configuration parameters can include parameters for configuring physical and MAC layer channels, bearers, etc. For example, configuration parameters can include parameters indicating the values ​​of timers for the physical layer, MAC layer, RLC layer, PCDP layer, SDAP layer, RRC layer, and / or communication channels.

[0388] A timer can begin running once started and continues running until it stops or expires. If the timer is not running, it can be started, or if it is running, it can be restarted. The timer can be associated with a value (e.g., the timer can start or restart from a certain value, or it can start from zero and expire once it reaches that value). The duration of the timer may not be updated until the timer stops or expires (e.g., due to BWP switching). The timer can be used to measure time periods / windows of a process. When the specification refers to embodiments and procedures relating to one or more timers, it should be understood that there are multiple ways to implement the one or more timers. For example, it should be understood that one or more of the multiple ways of implementing a timer can be used to measure time periods / windows of a process. For example, a random access response window timer can be used to measure a time window for receiving a random access response. In the example, instead of starting and expiring the random access response window timer, the time difference between two timestamps can be used. When the timer restarts, the measurement process for the time window can be restarted. Other example embodiments for restarting the measurement of a time window can be provided.

[0389] In RRC-connected mode, a wireless device can measure multiple beams (at least one) of a cell and average the measurement results (power values) to derive cell quality. In doing so, the wireless device can be configured to consider a subset of the detected beams. Filtering can be performed at two distinct levels: at the physical layer for deriving beam quality, and subsequently at the RRC layer for deriving cell quality from the multiple beams. For both serving and non-serving cells, cell quality from the beam measurements can be derived in the same manner. If the base station (e.g., a gNB) configures the wireless device to do this, the measurement report can contain measurement results for X optimal beams.

[0390] Figure 19The diagram illustrates a measurement model for a UE in RRC connected state. Layer 1 filtering can be internal Layer 1 filtering of the input measured at point A. The precision of the filtering is determined by the UE implementation, such as how the measurement can be performed in the physical layer using the implementation (input A and Layer 1 filtering). A is the measurement value (beam-specific sample) within the physical layer. A1 is the measurement value (e.g., beam-specific measurement value) reported from Layer 1 to Layer 3 after Layer 1 filtering. Layer 1 filtering may introduce a certain level of measurement averaging. How and when the UE precisely performs the required measurements can be specific to the implementation, provided that the output at B meets the defined minimum performance requirements.

[0391] exist Figure 19 In the example, B is a measurement (e.g., cell quality) derived from beam-specific measurements reported to Layer 3 after beam combining / selection. Beam combining / selection is a beam-specific measurement that is combined to derive cell quality. The configuration of this module is provided by RRC signaling. The reporting period at B can be equal to one measurement period at A1.

[0392] exist Figure 19 In the example, Layer 3 filtering for cell quality can be filtering performed on the measurement provided at point B. The configuration of the Layer 3 filter can be provided by RRC signaling. The filtering reporting period at C can be equal to one measurement period at B. Layer 3 filtering for cell quality and the relevant parameters used may not introduce any delay in sample availability between B and C. The measurement at point C, C1, is the input used in the event assessment. C is the measurement after processing in the Layer 3 filter. The reporting rate is the same as the reporting rate at point B. This measurement is used as input for one or more assessments of the reporting criteria. The assessment of the reporting criteria can check whether an actual measurement report is needed at point D. D is the measurement report information (message) sent on the radio interface. This assessment can be based on more than one measurement stream at reference point C, for example, to compare between different measurements. This can be illustrated by inputs C and C1. The UE assesses the reporting criteria at least each time a new measurement result is reported at points C and C1. This configuration can be provided by RRC signaling (UE measurement value).

[0393] exist Figure 19In the example, the L3 beam filtering and related parameters used may not introduce any delay in sample availability between E and F. L3 beam filtering is performed on the measurement values ​​(e.g., beam-specific measurements) provided at point A1. The configuration of the beam filter can be provided by RRC signaling. L3 beam filtering can provide K beams. The K beams can correspond to measurements on the SSB, or CSI-RS resources configured by the base station (e.g., gNB) for L3 mobility and detected by the UE at L1. The filtering reporting period at E can be equal to one measurement period at A1. E is the measurement value after processing in the beam filter (e.g., beam-specific measurement). The reporting rate can be the same as the reporting rate at point A1. This measurement value is used as input for selecting X measurements to be reported. Beam selection for beam reporting can select X measurements from the measurements provided at point E. The configuration of this module can be provided by RRC signaling. F is the beam measurement information included in the measurement report (transmitted) on the radio interface.

[0394] Measurement reports can be characterized by the following: measurement reports include measurement identifiers of associated measurement configurations that trigger the report; cell and beam measurements to be included in the measurement report are configured by the network; the network can be configured to limit the number of non-serving cells to be reported; cells belonging to a blacklist or exclusion list configured by the network are not used for event assessment and reporting, and conversely, when a whitelist is configured by the network, only cells belonging to the whitelist or allow list are used for event assessment and reporting; beam measurement values ​​to be included in the measurement report are configured by the network (beam identifier only, measurement result and beam identifier, or no beam report).

[0395] Intra-frequency adjacent (cell) measurements and inter-frequency adjacent (cell) measurements can be defined as follows: Intra-frequency measurement based on SSB, wherein the measurement is defined as an intra-frequency measurement based on SSB, provided that the center frequency of the SSB of the serving cell is the same as the center frequency of the SSB of the adjacent cell, and the subcarrier spacing of the two SSBs is also the same; Inter-frequency measurement based on SSB, wherein the measurement is defined as an inter-frequency measurement based on SSB, provided that the center frequency of the SSB of the serving cell is different from the center frequency of the SSB of the adjacent cell, or the subcarrier spacing of the two SSBs is different; Intra-frequency measurement based on CSI-RS; and Inter-frequency measurement based on CSI-RS, wherein if the measurement is not an intra-frequency measurement based on CSI-RS, then the measurement is defined as an inter-frequency measurement based on CSI-RS.

[0396] In-frequency measurement based on CSI-RS is defined as a measurement based on CSI-RS within a frequency range, provided that: the subcarrier spacing of the CSI-RS resources configured for measurement on the neighboring cell is the same as the SCS of the CSI-RS resources indicated for measurement on the serving cell; for a 60kHz subcarrier spacing, the CP type of the CSI-RS resources configured for measurement on the neighboring cell is the same as the CP type of the CSI-RS resources indicated for measurement on the serving cell; and the center frequency of the CSI-RS resources configured for measurement on the neighboring cell is the same as the center frequency of the CSI-RS resources indicated for measurement on the serving cell.

[0397] For SSB-based measurements, one measurement object can correspond to one SSB, and the wireless device treats different SSBs as different cells.

[0398] Whether a measurement is non-gap-assisted or gap-assisted depends on the capabilities of the radio device, the active BWP of the radio device, and the current operating frequency. For SSB-based inter-frequency measurements, if the radio device reports measurement gap requirement information, a measurement gap configuration can be provided based on that information. Otherwise, a measurement gap configuration is provided if: the radio device only supports per-radio-device measurement gaps; or if the radio device supports per-FR measurement gaps, and any serving cell in the serving cell is within the same frequency range as the measurement object. For SSB-based intra-frequency measurements, if the radio device reports measurement gap requirement information, a measurement gap configuration can be provided based on that information. Otherwise, a measurement gap configuration is always provided if: any of the BWPs configured by the radio device, other than the initial BWP, does not contain the frequency domain resources of the SSB associated with the initial DL BWP.

[0399] In non-gap-assisted scenarios, wireless devices can perform such measurements without a measurement gap. In gap-assisted scenarios, wireless devices are not considered capable of performing such measurements without a measurement gap.

[0400] Figure 20An example of a Layer 3 (L3) handover procedure is shown. A radio device can transmit a measurement report to a base station. The source base station can decide to hand over the radio device to the target base station. This decision can be based on the measurement report, load balancing requirements, source-related issues, and other gNBs, etc. The source base station can send a handover request message to the target base station, thereby conveying the information required to prepare the HO on the target side (radio device / UE X2 / Xn signaling context reference at the source base station, radio device / UE S1 EPC signaling context reference, target cell ID, KeNB* / KgNB*, RRC context including the identifier of the radio device in the source base station (e.g., Cell Radio Network Temporary Identifier, C-RNTI), AS configuration, radio (access) bearer context of the source cell, and physical layer ID + short MAC-I for possible RLF recovery). The radio (access) bearer context may include necessary radio network layer (RNL) and transport network layer (TNL) addressing information, as well as the E-RAB QoS profile. This information may further include at least the RRM configuration, including radio device inactivity times. AS configuration may include antenna information and DL carrier frequency, current QoS flow to DRB mapping rules applied to radio devices, SIB1 from the source base station, radio device capabilities for different RATs, and PDU session-related information. AS configuration may further include measurement information reported by the radio devices, including beam-related information. PDU session-related information may include slicing information and QoS flow level QoS profiles. The source base station may also request DAPS handover for one or more DRBs.

[0401] exist Figure 20In the example, if the target base station can grant resources, it can perform admission control based on the received radio (access) bearer QoS information to increase the likelihood of a successful HO. The target base station can configure the required resources based on the received radio (access) bearer QoS information and retain the C-RNTI and optionally the RACH preamble. The AS configuration used in the target cell can be specified independently (e.g., "establish") or as an increment compared to the AS configuration used in the source cell (e.g., "reconfigure"). The target base station can prepare an HO with L1 / L2 and send a handover request acknowledgment to the source base station. The handover request acknowledgment message can include a transparent container that is sent as an RRC message to the radio device to perform the handover. The container includes a new C-RNTI, a target base station security algorithm identifier with the selected security algorithm, may include a dedicated RACH preamble, and may include other parameters such as access parameters, SIBs, etc. For a no-RACH HO (e.g., if a no-RACH HO is configured), the container includes a timing adjustment indication and optionally pre-allocated uplink permission. If necessary, the switch request confirmation message may also include the RNL / TNL information of the forwarding tunnel.

[0402] exist Figure 20 In the example, the target base station can generate an RRC message to perform a handover. The RRC message can be an RRC reconfiguration message, which includes information for HO (Hosting Operations) that the source base station will send to the radio device (e.g., mobility control information or reconfiguration synchronization). The source base station can perform necessary integrity protection and encryption of the message.

[0403] exist Figure 20 In the example, the source base station can trigger a Uu handover by sending an RRC reconfiguration message to the radio device. This message contains information required for accessing the target cell: at least the target cell ID, the new C-RNTI, and the target base station security algorithm identifier for the selected security algorithm. The RRC reconfiguration can include a set of dedicated RACH resources, the association between RACH resources and SSBs, the association between RACH resources and radio device-specific CSI-RS configurations, public RACH resources, and system information of the target cell.

[0404] exist Figure 20In the example, the wireless device can receive an RRC reconfiguration message with necessary parameters (e.g., a new C-RNTI, a target base station security algorithm identifier, and optionally a dedicated RACH preamble, a target base station SIB, etc.) and execute the HO as instructed by the source base station. For a no-RACH HO (e.g., if a no-RACH HO is configured), the RRC reconfiguration may include a timing adjustment indication and, optionally, a pre-allocated uplink permission for accessing the target base station. If the pre-allocated uplink permission is not included, the wireless device can monitor the target base station's PDCCH for uplink permission. The wireless device may not need to delay the handover execution to deliver the HARQ / ARQ response to the source base station.

[0405] exist Figure 20 In the example, for cases without a RACH HO (e.g., if no RACH HO is not configured), after receiving an RRC reconfiguration message including information for the HO (e.g., mobility control information or reconfiguration synchronization), the radio device can perform synchronization with the target base station and access the target cell via RACH. If a dedicated RACH preamble is indicated in the information for the HO, a contention-free procedure is followed; otherwise, a contention-based procedure is followed. The radio device can derive a target base station-specific key and configure a selected security algorithm for use in the target cell. For cases without a RACH HO (e.g., if no RACH HO is not configured), the target base station can respond in advance via UL allocation and timing. For cases without a RACH HO (e.g., if no RACH HO is not configured), if the radio device successfully accesses the target cell, the radio device can send an RRC reconfiguration complete message (C-RNTI) to the target base station to confirm the handover, along with uplink BSR (Buffer Status Report) and / or UL data, thereby indicating that the radio device's handover procedure has been completed. The target base station can verify the C-RNTI sent in the RRC reconfiguration completion message. The target base station can now begin sending data to the wireless device.

[0406] exist Figure 20In the example, for a no-RACH HO (e.g., if no-RACH HO is configured), the radio device can perform synchronization with the target base station. The radio device derives the target base station-specific key and configures the selected security algorithm to be used in the target cell. For a no-RACH HO (e.g., if no-RACH HO is configured), if the radio device does not receive periodically pre-allocated uplink permission in an RRC reconfiguration message that includes information for the HO (e.g., mobility control information or reconfiguration synchronization), the radio device can receive uplink permission via the target cell's PDCCH. The radio device can use the first available uplink permission after synchronizing with the target cell. For a no-RACH HO (e.g., if no-RACH HO is configured), after receiving uplink permission, the radio device can send an RRC reconfiguration complete message (C-RNTI) to the target base station to confirm the handover, along with uplink BSR and / or UL data, as far as possible. The target base station can verify the C-RNTI sent in the RRC reconfiguration complete message. The target base station can now be able to begin sending data to the radio device. The handover procedure of a wireless device can be completed when the wireless device receives the MAC control element (Wiring Control Element) from the target base station.

[0407] exist Figure 20 In the example, if both types of measurements are available, the RRM configuration can include beam measurement information (for Layer 3 mobility) associated with the SSB and CSI-RS of the reported cell. The RRM measurement information can include beam measurements belonging to the listed cells of the target base station. The public RACH configuration of beams in the target cell can be associated only with the SSB. The network may be able to have a dedicated RACH configuration associated with the SSB and / or a dedicated RACH configuration associated with the CSI-RS within the cell. The target base station can only include one of the following RACH configurations in its handover command to enable radio devices to access the target cell: public RACH configuration; public RACH configuration + dedicated RACH configuration associated with the SSB; public RACH configuration + dedicated RACH configuration associated with the CSI-RS. Dedicated RACH configurations can allocate RACH resources and quality thresholds for their use. When dedicated RACH resources are provided, radio devices can prioritize them, and will not switch to contention-based RACH resources as long as the quality thresholds for those dedicated resources are met. The order of access to dedicated RACH resources can depend on the radio device implementation.

[0408] In the example, the wireless device can transmit a no-RACH HO capability indication to the base station, thereby indicating whether the wireless device supports no-RACH handover. Based on the no-RACH HO capability indication, the base station can determine and transmit the configuration for no-RACH HO (RACH skip configuration).

[0409] In the example, for network-controlled mobility in an RRC connection state (e.g., L3 handover), an RRC connection reconfiguration message (e.g., RRCReconfiguration) can be used to change the PCell, which includes `reconfigurationWithSync` (in the NR specification) or `mobilityControlInfo` (in the LTE specification, handover). The SCell can be changed using an RRC connection reconfiguration message with or without `reconfigurationWithSync` or `mobilityControlInfo`. The network can trigger the HO procedure, for example, based on radio conditions, load, QoS, UE category, etc. The RRC connection reconfiguration message can be based on information to be provided later. Figure 21 and Figure 22 The example described in the document will be used for implementation.

[0410] like Figure 20 As shown, the network can configure the wireless device to perform measurement reporting (potentially including the configuration of measurement intervals). Measurement reporting is a Layer 3 report, distinct from Layer 1 CSI reporting. The wireless device can transmit one or more measurement reports to the source base station (or source PCell). In the example, the network can, for instance, blindly initiate a HO (House of Interest) even without receiving a measurement report from the wireless device. Before sending the HO message to the wireless device, the source base station can prepare one or more target cells. The source base station can select the target PCell.

[0411] like Figure 20 As shown, based on one or more measurement reports from wireless devices, the source base station can provide the target base station with a list of the best cells for which measurement information is available on each frequency, for example, in descending order of RSRP values. The source base station may also include available measurement information for the cells provided in the list. The target base station can determine which cells to configure for use after the HO (House of Interest), which may include cells other than those indicated by the source base station. In the example, as... Figure 20 As shown, the source base station can transmit a HO request to the target base station. The target base station can respond with a HO message. In the example, the target base station can indicate the access layer configuration to be used in the target cell of the wireless device in the HO message.

[0412] In the example, the source base station can transparently (e.g., without changing the values / content) forward HO messages / information received from the target base station to the radio device. Within the HO message, RACH resource configuration can be set to enable the radio device to access the cell in the target base station. Where appropriate, the source base station can initiate data forwarding for a subset of dedi...

Claims

1. A method comprising: A radio resource control (RRC) reconfiguration message is received by a wireless device from a base station including a base station central unit and the serving base station distributed unit via a serving cell associated with the serving base station distributed unit. The radio resource control (RRC) reconfiguration message includes: First configuration parameters for a first type of RACH-less cell handover, wherein the first configuration parameters indicate the physical uplink shared channel (PUSCH) resources of the target cell for the radio device to perform a configuration-based CG-granted RACH-less cell handover; and A second type of second configuration parameter for RACH-free cell handover, wherein the second configuration parameter indicates the physical downlink control channel (PDCCH) resources of the target cell for the radio device to perform RACH-free cell handover based on dynamic granting (DG); and The wireless device receives a signal from the base station via the serving cell, including a Medium Access Control (MACCE) control element or Downlink Control Information (DCI) signal, wherein the signal indicates the target cell and the type of RACH-free cell handover to the target cell, wherein: The type of RACH-free cell handover is determined by the base station, the base station central unit, and / or the serving base station distributed unit; and The types of RACH-free cell handover include the first type of RACH-free cell handover associated with CG-based RACH-free cell handover, or the second type of RACH-free cell handover associated with DG-based RACH-free cell handover. The wireless device performs a RACH-free cell handover to the target cell based on the type of RACH-free cell handover indicated by the signal, wherein performing the RACH-free cell handover includes: Based on the first type indicated by the signal as having no RACH cell handover: The wireless device transmits an RRC reconfiguration complete message to the target base station distributed element via the PUSCH resource of the target cell indicated by the first configuration parameter; and Based on the second type indicated by the signal as having no RACH cell handover: The wireless device monitors the PDCCH resources indicated by the second configuration parameter; Receive the DG indicating the uplink resources of the target cell via the PDCCH resources indicated by the second configuration parameter; and The wireless device transmits an RRC reconfiguration complete message to the target base station distributed unit via the uplink resources of the target cell indicated by the DG.

2. A method comprising: A wireless device receives from a base station a signal indicating a type of RACH-free cell handover to a target cell, wherein the type of RACH-free cell handover includes: The first type of RACH-free cell handover associated with configuration-based CG-granted RACH-free cell handover; or The second type of RACH-free cell handover associated with RACH-free cell handover based on dynamic permission DG; and The wireless device performs a RACH-free cell handover to the target cell based on the type of RACH-free cell handover indicated by the signal.

3. The method of claim 2, wherein the signal includes a Media Access Control Element (MAC CE) or Downlink Control Information (DCI).

4. The method as described in one or more of claims 2 to 3, wherein the signal is a cell handover command.

5. The method according to one or more of claims 2 to 4, wherein: The signal includes fields; and The field includes a value indicating the type of cell handover.

6. The method of claim 5, wherein: The value is a first value indicating the first type of cell handover; and The value is a second value indicating the second type of cell handover.

7. The method of one or more of claims 2 to 6, wherein the RACH-free cell handover comprises: Normal handover, conditional handover (CHO); mobility LTM triggered by Layer 1 or Layer 2; Conditional LTM; Normal primary and secondary cell PSCell changes; And / or normal PSCell addition; conditional primary and secondary cell PSCell change; and / or conditional PSCell addition.

8. The method of one or more of claims 2 to 7, wherein the type of no-RACH cell handover is determined by the base station, the base station central unit of the base station, the first base station distributed unit of the base station, and / or the serving base station distributed unit of the base station.

9. The method of one or more of claims 2 to 8, wherein the signal indicates the target cell.

10. The method of one or more of claims 2 to 9, further comprising the wireless device receiving from the base station a first configuration parameter of the first type for RACH-free cell handover and / or a second configuration parameter of the second type for RACH-free cell handover.

11. The method of claim 10, wherein the first configuration parameter and / or the second configuration parameter are received in an RRC reconfiguration message and / or via the serving cell of the radio device.

12. The method of one or more of claims 10 to 11, wherein the RRC reconfiguration message indicates a timing adjustment (TA) indication for the target cell.

13. The method of one or more of claims 10 to 12, wherein the first configuration parameter indicates the Physical Uplink Shared Channel (PUSCH) resource of the target cell.

14. The method of one or more of claims 10 to 13, wherein the second configuration parameter indicates the physical downlink control channel (PDCCH) resources of the target cell.

15. The method of one or more of claims 2 to 14, further comprising performing a RACH-free cell handover to the target cell by the wireless device based on the type of RACH-free cell handover indicated by the signal.

16. The method of one or more of claims 2 to 15, further comprising transmitting an RRC reconfiguration complete message by the wireless device via the target cell.

17. The method of claim 16, wherein the RRC reconfiguration complete message is transmitted based on the first type indicated by the signal as no RACH cell handover: Use the first configuration parameters for the handover of the RACH-free cell; and / or This is done via the Physical Uplink Shared Channel (PUSCH) resources of the target cell.

18. The method of claim 16, wherein the RRC reconfiguration complete message is transmitted based on the second type indicated by the signal as no RACH cell handover: Use the second configuration parameter for the handover of the RACH-free cell; and / or This is done via the uplink resources of the target cell indicated by the DG.

19. The method of claim 18, further comprising: The physical downlink control channel (PDCCH) resources of the target cell, as indicated by the second configuration parameter, are monitored by the wireless device. And / or The DG, which indicates the uplink resources of the target cell, is received by the wireless device.

20. The method of claim 19, wherein the DG is received via the PDCCH resources of the target cell indicated by the second configuration parameter.

21. A method comprising: A signal indicating a type of RACH-free cell handover to a target cell is transmitted from the base station to the radio device, wherein the type of RACH-free cell handover includes: The first type of RACH-free cell handover associated with configuration-based CG-granted RACH-free cell handover; or The second type of RACH-free cell handover is associated with RACH-free cell handover based on dynamic grant DG.

22. The method of claim 21, further comprising determining the type of cell handover without RACH by the base station.

23. The method of one or more of claims 21 to 22, further comprising transmitting, from the base station to the wireless device, a first configuration parameter of the first type for RACH-free cell handover and / or a second configuration parameter of the second type for RACH-free cell handover.

24. The method of claim 23, wherein the first configuration parameter and / or the second configuration parameter are received in an RRC reconfiguration message and / or via the serving cell of the radio device.

25. The method of claim 24, wherein the RRC reconfiguration message indicates a timing adjustment (TA) indication for the target cell.

26. The method of one or more of claims 23 to 25, wherein the first configuration parameter indicates the Physical Uplink Shared Channel (PUSCH) resource of the target cell.

27. The method of one or more of claims 23 to 26, wherein the second configuration parameter indicates the physical downlink control channel (PDCCH) resources of the target cell.

28. The method of one or more of claims 21 to 25, wherein the transmission of the signal is performed via: The first cell of the first base station distributed unit of the base station; and / or The base station serves the cell of the base station distributed unit.

29. The method of one or more of claims 21 to 28, further comprising the base station receiving a Radio Resource Control (RRC) reconfiguration complete message from the wireless device.

30. The method of claim 29, wherein receiving the RRC reconfiguration complete message is performed via: The second cell of the second base station distributed unit of the base station; and / or The target cell of the target base station distributed unit of the base station.

31. A method comprising: The base station central unit of the base station sends an indication of the type of RACH-free cell handover to the target cell to the first base station distributed unit of the base station, wherein the type of RACH-free cell handover includes: The first type of RACH-free cell handover associated with configuration-based CG-granted RACH-free cell handover; or The second type of RACH-free cell handover is associated with RACH-free cell handover based on dynamic grant DG.

32. The method of claim 31, further comprising sending the indication of the type of handover without RACH to a second base station distributed unit of the base station from the central unit of the base station.

33. The method of one or more of claims 31 to 32, further comprising determining the type of cell handover without RACH by the central unit of the base station.

34. The method of one or more of claims 31 to 33, further comprising transmitting, by the base station central unit, a first configuration parameter of the first type for RACH-free cell handover and / or a second configuration parameter of the second type for RACH-free cell handover to the wireless device and / or via the first base station distributed unit.

35. The method of claim 34, wherein the first configuration parameter and / or the second configuration parameter are received in an RRC reconfiguration message and / or via the serving cell of the radio device.

36. The method of claim 35, wherein the RRC reconfiguration message indicates a timing adjustment (TA) indication for the target cell.

37. The method of one or more of claims 34 to 36, wherein the first configuration parameter indicates the Physical Uplink Shared Channel (PUSCH) resource of the target cell.

38. The method of one or more of claims 34 to 37, wherein the second configuration parameter indicates the physical downlink control channel (PDCCH) resources of the target cell.

39. The method of one or more of claims 31 to 38, further comprising receiving a Radio Resource Control (RRC) reconfiguration complete message from the radio device by the central unit of the base station.

40. The method of claim 39, wherein receiving the RRC reconfiguration complete message is performed via: The second cell of the second base station distributed unit of the base station; and / or The target cell of the target base station distributed unit of the base station.

41. A method comprising: The first base station distributed unit of the base station transmits a signal to the radio device indicating the type of RACH-free cell handover to the target cell, wherein the type of RACH-free cell handover includes: The first type of RACH-free cell handover associated with configuration-based CG-granted RACH-free cell handover; or The second type of RACH-free cell handover is associated with RACH-free cell handover based on dynamic grant DG.

42. The method of claim 41, further comprising: The type of cell handover without RACH is determined by the first base station distributed unit; And / or The first base station distributed unit sends an indication of the type of handover for cells without RACH to the base station central unit.

43. The method of claim 41, further comprising receiving, from the base station central unit, an indication of the type of handover without RACH by the first base station distributed unit.

44. The method of one or more of claims 41 to 43, further comprising receiving, by the first base station distributed unit from the base station central unit and / or transmitting, by the first base station distributed unit to the wireless device, a first configuration parameter of the first type for RACH-free cell handover and / or a second configuration parameter of the second type for RACH-free cell handover.

45. The method of claim 44, wherein the RRC reconfiguration message indicates a timing adjustment (TA) indication for the target cell.

46. ​​The method of one or more of claims 44 to 45, wherein the first configuration parameter indicates the Physical Uplink Shared Channel (PUSCH) resource of the target cell.

47. The method of one or more of claims 44 to 46, wherein the second configuration parameter indicates the physical downlink control channel (PDCCH) resources of the target cell.

48. The method of one or more of claims 41 to 46, wherein the transmission of the signal is performed via: The first cell of the first base station distributed unit of the base station; and / or The base station serves the cell of the base station distributed unit.

49. The method of one or more of claims 41 to 47, wherein the first base station distributed unit of the base station is the serving base station distributed unit of the wireless device.

50. A method comprising: The second base station distributed unit of the base station receives from the base station central unit of the base station an indication of the type of RACH-free cell handover to the target cell of the second base station distributed unit, wherein the type of RACH-free cell handover includes: The first type of RACH-free cell handover associated with configuration-based CG-granted RACH-free cell handover; or The second type of RACH-free cell handover is associated with RACH-free cell handover based on dynamic grant DG.

51. The method of claim 49, wherein the type of RACH-free cell handover is the first type of RACH-free cell handover, and the Radio Resource Control (RRC) reconfiguration complete message is received from the radio device via the Physical Uplink Shared Channel (PUSCH) resource of the target cell.

52. The method of claim 49, wherein the type of no-RACH cell handover is the second type of no-RACH cell handover, and a Radio Resource Control (RRC) reconfiguration complete message is received from the radio device via the uplink resources of the target cell.

53. The method of claim 52, further comprising transmitting a DG indicating the uplink resources of the target cell to the wireless device by the second base station distributed unit.

54. The method of claim 53, wherein the DG is transmitted via the Physical Downlink Control Channel (PDCCH) resources of the target cell.

55. The method of one or more of claims 50 to 54, wherein the second base station distributed unit of the base station is a target base station distributed unit of the wireless device.

56. An apparatus comprising one or more processors and a memory storing instructions, the instructions, when executed by the one or more processors, causing the apparatus to perform the method as claimed in any one of claims 1 to 55.

57. A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors of a device, cause the device to perform the method as claimed in any one of claims 1 to 55.

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