Radio Access Network Notification Area Update Failed

Abstract

A method and a base station are provided. The method includes: sending a first message by a first base station to a wireless device, the first message indicating an RRC state transition of the wireless device from a radio resource control (RRC) connected state to an RRC inactive state, wherein the first message includes a parameter indicating a value associated with a wireless device radio access network notification area update timer for a periodic radio access network (RAN) notification area (RNA) update process; receiving a second message indicating RNA update from the wireless device by the first base station; starting a network RNA update timer by the first base station, wherein the first base station determines that the periodic RNA update process is unsuccessful based on expiration of the network RNA update timer; and sending a third message by the first base station to a core network entity indicating a wireless device context release request for the wireless device in response to expiration of the network RNA update timer, wherein the third message includes an identifier of the wireless device.

Description

[0001] This application is a divisional application of the application with the application date of March 19, 2018 and the application number 201880018836.0, and the invention name is "Radio access network notification area update failure".

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Application No. 62 / 473,010, filed on March 17, 2017, which is incorporated herein by reference in its entirety. Technical Field

[0004] Embodiments of the present invention generally relate to a base station and a method for a base station. Summary of the invention

[0005] According to one aspect of the present invention, a method is provided. The method includes: sending a first message by a first base station to a wireless device, the first message indicating an RRC state transition of the wireless device from a radio resource control (RRC) connected state to an RRC inactive state, wherein the first message includes a parameter indicating a value associated with a wireless device radio access network notification area update timer for a periodic radio access network (RAN) notification area (RNA) update process; receiving a second message indicating RNA update from the wireless device by the first base station; starting a network RNA update timer by the first base station, wherein the first base station determines that the periodic RNA update process is unsuccessful based on the expiration of the network RNA update timer; and sending a third message by the first base station to a core network entity and in response to the expiration of the network RNA update timer indicating a wireless device context release request for the wireless device, wherein the third message includes an identifier of the wireless device.

[0006] According to another aspect of the present invention, a base station is provided. The base station includes a transceiver and at least one processor, wherein the at least one processor is configured to: control the transceiver to send a first message to a wireless device, the first message indicating an RRC state transition of the wireless device from a radio resource control (RRC) connected state to an RRC inactive state, wherein the first message includes a parameter indicating a value associated with a wireless device radio access network notification area update timer for a periodic radio access network (RAN) notification area (RNA) update process; control the transceiver to receive a second message indicating an RNA update from the wireless device; start a network RNA update timer, wherein the base station determines that the periodic RNA update process is unsuccessful based on the expiration of the network RNA update timer; and control the transceiver to send a third message indicating a wireless device context release request for the wireless device to a core network entity and in response to the expiration of the network RNA update timer, wherein the third message includes an identifier of the wireless device. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Examples of several of the various embodiments of the present disclosure are described herein with reference to the drawings.

[0008] Figure 1 is a diagram of an example RAN architecture according to aspects of an embodiment of the present disclosure.

[0009] Figure 2A is a diagram of an example user plane protocol stack according to aspects of an embodiment of the present disclosure.

[0010] Figure 2B is a diagram of an example control plane protocol stack in accordance with aspects of an embodiment of the present disclosure.

[0011] Figure 3 is a diagram of an example wireless device and two base stations in accordance with aspects of an embodiment of the present disclosure.

[0012] Figure 4A , Figure 4B , Figure 4C and Figure 4D is an example diagram of uplink and downlink signal transmission according to aspects of an embodiment of the present disclosure.

[0013] Figure 5A is a diagram of an example uplink channel map and example uplink physical signals according to aspects of an embodiment of the present disclosure.

[0014] Figure 5B is a diagram of an example downlink channel map and example downlink physical signals according to aspects of an embodiment of the present disclosure.

[0015] Figure 6 A diagram depicting an example frame structure according to aspects of an embodiment of the present disclosure.

[0016] Fig. 7A and Figure 7B A diagram depicting an example set of OFDM subcarriers according to aspects of an embodiment of the present disclosure.

[0017] Figure 8 A diagram depicting example OFDM radio resources in accordance with aspects of an embodiment of the present disclosure.

[0018] Fig.9A and Fig. 9B is a diagram of example multiple connectivity according to aspects of an embodiment of the present disclosure.

[0019] Fig.10 is a diagram of an example random access procedure according to aspects of an embodiment of the present disclosure.

[0020] Fig.11 Detailed Description of the Invention The structure of an example MAC entity according to aspects of an embodiment of the present disclosure.

[0021] Fig.12 is a diagram of an example RAN architecture according to aspects of an embodiment of the present disclosure.

[0022] Fig.13 is a diagram of example RRC states according to aspects of an embodiment of the present disclosure.

[0023] Fig.14 Detailed description of the invention The invention is an example diagram according to aspects of embodiments of the present disclosure.

[0024] Fig.15 is an example flow chart according to aspects of an embodiment of the present disclosure.

[0025] Fig.16 Detailed description of the invention The invention is an example diagram according to aspects of embodiments of the present disclosure.

[0026] Fig.17 is an example flow chart according to aspects of an embodiment of the present disclosure.

[0027] Fig.18 Detailed description of the invention The invention is an example diagram according to aspects of embodiments of the present disclosure.

[0028] Fig.19 is an example flow chart according to aspects of an embodiment of the present disclosure.

[0029] Fig. 20 Detailed description of the invention The invention is an example diagram according to aspects of embodiments of the present disclosure.

[0030] Fig.21 is an example flow chart according to aspects of an embodiment of the present disclosure.

[0031] Fig. 22 Detailed description of the invention The invention is an example diagram according to aspects of embodiments of the present disclosure.

[0032] Fig.23 Detailed description of the invention The invention is an example diagram according to aspects of embodiments of the present disclosure.

[0033] Fig.24 is an example flow chart according to aspects of an embodiment of the present disclosure.

[0034] Fig.25 Detailed description of the invention The invention is an example diagram according to aspects of embodiments of the present disclosure.

[0035] Fig.26 is an example flow chart according to aspects of an embodiment of the present disclosure.

[0036] Fig. 27 is an example flow chart according to aspects of an embodiment of the present disclosure.

[0037] Fig.28 Detailed description of the invention The invention is an example diagram according to aspects of embodiments of the present disclosure.

[0038] Fig.29 is an example flow chart according to aspects of an embodiment of the present disclosure.

[0039] Fig.30 Detailed description of the invention The invention is an example diagram according to aspects of embodiments of the present disclosure.

[0040] Fig.31 is an example flow chart according to aspects of an embodiment of the present disclosure.

[0041] Fig.32 Detailed description of the invention The invention is an example diagram according to aspects of embodiments of the present disclosure.

[0042] Fig.33 is an example flow chart according to aspects of an embodiment of the present disclosure.

[0043] Fig.34 Detailed description of the invention The invention is an example diagram according to aspects of embodiments of the present disclosure.

[0044] Fig.35 is an example flow chart according to aspects of an embodiment of the present disclosure.

[0045] Fig.36 Detailed description of the invention The invention is an example diagram according to aspects of embodiments of the present disclosure.

[0046] Fig.37 Detailed description of the invention The invention is an example diagram according to aspects of embodiments of the present disclosure.

[0047] Fig.38 is an example flow chart according to aspects of an embodiment of the present disclosure.

[0048] Fig.39 Detailed description of the invention The invention is an example diagram according to aspects of embodiments of the present disclosure.

[0049] Fig.40 is an example flow chart according to aspects of an embodiment of the present disclosure.

[0050] Fig.41 is an example flow chart according to aspects of an embodiment of the present disclosure. DETAILED DESCRIPTION

[0051] Example embodiments of the present disclosure enable the operation of a communication network. Embodiments of the technology disclosed herein may be used in the technical field of multi-carrier communication systems. More specifically, embodiments of the technology disclosed herein may relate to a radio access network in a multi-carrier communication system.

[0052] The following abbreviations are used throughout this disclosure:

[0053] 3GPP Third Generation Partnership Project

[0054] 5GC 5G Core Network

[0055] ACK

[0056] AMF Access and Mobility Management Function

[0057] ARQ Automatic Repeat Request

[0058] AS access layer

[0059] ASIC Application-Specific Integrated Circuit

[0060] BA Bandwidth Adaptation

[0061] BCCH Broadcast Control Channel

[0062] BCH Broadcast Channel

[0063] BPSK Binary Phase Shift Keying

[0064] BWP Bandwidth Part

[0065] CA Carrier Aggregation

[0066] CC Component Carrier

[0067] CCCH Common Control Channel

[0068] CDMA Code Division Multiple Access

[0069] CN Core Network

[0070] CP Cyclic Prefix

[0071] CP-OFDM Cyclic Prefix-Orthogonal Frequency Division Multiplexing

[0072] C-RNTI Cell-Radio Network Temporary Identifier

[0073] Scheduling of CS Configuration

[0074] CSI Channel State Information

[0075] CSI-RS Channel State Information-Reference Signal

[0076] CQI Channel Quality Indicator

[0077] CSS Common Search Space

[0078] CU Central Unit

[0079] DC Dual Connectivity

[0080] DCCH Dedicated Control Channel

[0081] DCI Downlink Control Information

[0082] DL Downlink

[0083] DL-SCH Downlink Shared Channel

[0084] DM-RS Demodulation Reference Signal

[0085] DRB Data Radio Bearing

[0086] DRX Discontinuous Reception

[0087] DTCH Dedicated Traffic Channel

[0088] DU Distributed Unit

[0089] EPC Evolved Packet Core

[0090] E-UTRA Evolved UMTS Terrestrial Radio Access

[0091] E-UTRAN Evolved Universal Terrestrial Radio Access Network

[0092] FDD Frequency Division Duplex

[0093] FPGA Field Programmable Gate Array

[0094] F1-C F1-Control Plane

[0095] F1-U F1-User Plane

[0096] gNB Next Generation Node B

[0097] HARQ Hybrid Automatic Repeat Request

[0098] HDL Hardware Description Language

[0099] IE Information Elements

[0100] IP Internet Protocol

[0101] LCID Logical Channel Identifier

[0102] LTE Long Term Evolution

[0103] MAC Media Access Control

[0104] MCG Master Cell Group

[0105] MCS modulation and coding scheme

[0106] MeNB Leading Node B

[0107] MIB Master Information Block

[0108] MME Mobility Management Entity

[0109] MN Master Node

[0110] NACK Negative Acknowledgement

[0111] NAS Non-Access Layer

[0112] NG CP Next Generation Control Plane

[0113] NGC Next Generation Core

[0114] NG-C NG-Control Plane

[0115] ng-eNB Next Generation Evolved Node B

[0116] NG-U NG-User Plane

[0117] NR New Radio

[0118] NR MAC New Radio MAC

[0119] NR PDCP New Radio PDCP

[0120] NR PHY New Radio Physics

[0121] NR RLC New Radio RLC

[0122] NR RRC New Radio RRC

[0123] NSSAI Network Slice Selection Assistant Information

[0124] O&M Operation and Maintenance

[0125] OFDM Orthogonal Frequency Division Multiplexing

[0126] PBCH Physical Broadcast Channel

[0127] PCC Primary Component Carrier

[0128] PCCH Paging Control Channel

[0129] PCell Primary Community

[0130] PCH Paging Channel

[0131] PDCCH Physical Downlink Control Channel

[0132] PDCP Packet Data Convergence Protocol

[0133] PDSCH Physical Downlink Shared Channel

[0134] PDU Protocol Data Unit

[0135] PHICH Physical HARQ Indicator Channel

[0136] PHY

[0137] PLMN Public Land Mobile Network

[0138] PMI Precoding Matrix Indicator

[0139] PRACH Physical Random Access Channel

[0140] PRB Physical Resource Block

[0141] PSCell Primary Secondary Cell

[0142] PSS Primary Synchronization Signal

[0143] pTAG Primary Timing Advance Group

[0144] PT-RS Phase Tracking Reference Signal

[0145] PUCCH Physical Uplink Control Channel

[0146] PUSCH Physical Uplink Shared Channel

[0147] QAM Quadrature Amplitude Modulation

[0148] QFI Quality of Service Indicator

[0149] QoS Quality of Service

[0150] QPSK Quadrature Phase Shift Keying

[0151] RA Random Access

[0152] RACH Random Access Channel

[0153] RAN Radio Access Network

[0154] RAT Radio Access Technology

[0155] RA-RNTI Random Access-Radio Network Temporary Identifier

[0156] RB Resource Block

[0157] RBG Resource Block Group

[0158] RI Rank Indicator

[0159] RLC Radio Link Control

[0160] RRC Radio Resource Control

[0161] RS reference signal

[0162] RSRP Reference Signal Received Power

[0163] SCC Secondary Component Carrier

[0164] SCell Secondary Cell

[0165] SCG Secondary Cell Group

[0166] SC-FDMA Single Carrier Frequency Division Multiple Access

[0167] SDAP Service Data Adaptation Protocol

[0168] SDU Service Data Unit

[0169] SeNB Secondary Evolved Node B

[0170] SFN System Frame Number

[0171] S-GW Service Gateway

[0172] SI System Information

[0173] SIB System Information Block

[0174] SMF session management functions

[0175] SN Secondary Node

[0176] SpCell Special Cell

[0177] SRB Signal Radio Carrier

[0178] SRS Sounding Reference Signal

[0179] SS Sync Signal

[0180] SSS Secondary Sync Signal

[0181] sTAG Secondary Timing Advance Group

[0182] TA Timing Advance

[0183] TAG Timing Advance Group

[0184] TAI Tracking Area Identifier

[0185] TAT Time Alignment Timer

[0186] TB Transfer Block

[0187] TC-RNTI Temporary Cell-Radio Network Temporary Identifier

[0188] TDD Time Division Duplex

[0189] TDMA Time Division Multiple Access

[0190] TTI Transmit Time Interval

[0191] UCI Uplink Control Information

[0192] UE User Equipment

[0193] UL Uplink

[0194] UL-SCH Uplink Shared Channel

[0195] UPF User Plane Function

[0196] UPGW User Plane Gateway

[0197] VHDL VHSIC Hardware Description Language

[0198] Xn-C Xn-Control Plane

[0199] Xn-U Xn-User Plane

[0200] Various physical layer modulation and transmission mechanisms may be used to implement example embodiments of the present disclosure. Example transmission mechanisms may include, but are not limited to, code division multiple access (CDMA), orthogonal frequency division multiple access (OFDMA), time division multiple access (TDMA), wavelet techniques, etc. Hybrid transmission mechanisms such as TDMA / CDMA and OFDM / CDMA may also be employed. Various modulation schemes may be applied to signal transmission in the physical layer. Examples of modulation schemes include, but are not limited to, phase, amplitude, code, combinations of these, and / or the like. Example radio transmission methods may implement quadrature amplitude modulation (QAM) using binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), 16-QAM, 64-QAM, 256-QAM, etc. Physical radio transmission may be enhanced by dynamically or semi-dynamically changing the modulation and coding schemes according to transmission requirements and radio conditions.

[0201] Figure 11 is an example radio access network (RAN) architecture according to aspects of an embodiment of the present disclosure. As shown in the example, the RAN node can be a next generation node B (gNB) (e.g., 120A, 120B) that provides a new radio (NR) user plane and control plane protocol termination to a first wireless device (e.g., 110A). In an example, the RAN node can be a next generation evolved node B (ng-eNB) (e.g., 124A, 124B) that provides an evolved UMTS terrestrial radio access (E-UTRA) user plane and control plane protocol termination to a second wireless device (e.g., 110B). The first wireless device can communicate with the gNB via a Uu interface. The second wireless device can communicate with the ng-eNB via a Uu interface. In the present disclosure, wireless devices 110A and 110B are structurally similar to wireless device 110. Base stations 120A and / or 120B can be structurally similar to base station 120. The base station 120 may include at least one of a gNB (e.g., 122A and / or 122B), an ng-eNB (e.g., 124A and / or 124B), and the like.

[0202] The gNB or ng-eNB may host functions such as radio resource management and scheduling, IP header compression, encryption and integrity protection of data, selection of the access and mobility management function (AMF) at which the user equipment (UE) attaches, routing of user plane and control plane data, connection setup and release, scheduling and transmission of paging messages (originating from the AMF), scheduling and transmission of system broadcast information (originating from the AMF or operation and maintenance (O&M)), measurements and measurement report configuration, transport layer packet marking in the uplink, session management, network slicing support, Quality of Service (QoS) flow management and mapping to data radio bearers, support for UEs in RRC_INACTIVE state, distribution functions for non-access stratum (NAS) messages, RAN sharing, and dual connectivity or tight interworking between NR and E-UTRA.

[0203] In an instance, one or more gNBs and / or one or more ng-eNBs may be interconnected to each other via an Xn interface. A gNB or ng-eNB may be connected to a 5G core network (5GC) via an NG interface. In an instance, a 5GC may include one or more AMF / User Planning Function (UPF) functions (e.g., 130A or 130B). A gNB or ng-eNB may be connected to the UPF via an NG user plane (NG-U) interface. The NG-U interface may provide delivery of user plane protocol data units (PDUs) (e.g., non-guaranteed delivery) between the RAN node and the UPF. A gNB or ng-eNB may be connected to the AMF via an NG control plane (NG-C) interface. The NG-C interface may provide, for example, NG interface management, UE context management, UE mobility management, transmission of NAS messages, paging, PDU session management, configuration delivery and / or warning message transmission, combinations thereof, and the like.

[0204] In one instance, the UPF may host functions such as an anchor point for intra / inter-radio access technology (RAT) mobility (when applicable), an external PDU session point for interconnection to a data network, packet routing and forwarding, user plane portion of packet inspection and policy rule enforcement, service usage reporting, an uplink classifier to support routing of service flows to the data network, a branch point to support multi-host PDU sessions, QoS processing for the user plane (e.g., packet filtering, gating), uplink (UL) / downlink (DL) rate enforcement, uplink service verification (e.g., service data flow (SDF) to QoS flow mapping), downlink packet buffering and / or downlink data notification triggering.

[0205] In one instance, the AMF may host functions such as NAS signaling termination, NAS signaling security, access layer (AS) security control, core network (CN) inter-node signaling for mobility between 3rd Generation Partnership Project (3GPP) access networks, idle mode UE reachability (e.g., control and execution of paging retransmissions), registration area management, support for intra-system and inter-system mobility, access authentication, access authorization including roaming rights check, mobility management control (subscription and policy), support for network slicing and / or session management function (SMF) selection, etc.

[0206] Figure 2Ais an example user plane protocol stack, in which service data adaptation protocol (SDAP) (e.g., 211 and 221), packet data convergence protocol (PDCP) (e.g., 212 and 222), radio link control (RLC) (e.g., 213 and 223), and medium access control (MAC) (e.g., 214 and 224) sublayers and physical (PHY) (e.g., 215 and 225) layers may be terminated in a wireless device (e.g., 110) and a gNB (e.g., 120) on the network side. In an example, the PHY layer provides transport services to higher layers (e.g., MAC, RRC, etc.). In an example, the services and functions of the MAC sublayer may include mapping between logical channels and transport channels, multiplexing of MAC service data units (SDUs) belonging to one or different logical channels into transport blocks (TBs) delivered to / from the PHY layer / demultiplexing from the transport blocks, scheduling information reporting, error correction by hybrid automatic repeat request (HARQ) (e.g., one HARQ entity per carrier in the case of carrier aggregation (CA)), priority handling between UEs through dynamic scheduling, priority handling between logical channels of a UE through logical channel prioritization and / or padding. The MAC entity may support one or more digital and / or transmission timings. In an example, mapping restrictions in logical channel prioritization may control which digital and / or transmission timing a logical channel may use. In an example, the RLC sublayer may support transparent mode (TM), unacknowledged mode (UM), and acknowledged mode (AM) transmission modes. The RLC configuration may be based on each logical channel, independent of the digital and / or transmission time interval (TTI) duration. In an example, the automatic repeat request (ARQ) may operate on any digital and / or TTI duration configured for the logical channel. In an example, the services and functions of the PDCP layer for the user plane may include sequence numbering, header compression and decompression, delivery of user data, reordering and duplication detection, PDCP PDU routing (e.g., in the case of separate bearer), retransmission of PDCP SDU, encryption, decryption and integrity protection, PDCP SDU discard, PDCP reconstruction and data recovery of RLC AM, and / or duplication of PDCP PDU. In an example, the services and functions of SDAP may include mapping between QoS flows and data wireless bearers. In an example, the services and functions of SDAP may include mapping of service quality indicators (QFIs) in DL and UL packets. In an example, the protocol entities of SDAP may be configured for individual PDU sessions.

[0207] Figure 2Bis an example control plane protocol stack, wherein PDCP (e.g., 233 and 242), RLC (e.g., 234 and 243) and MAC (e.g., 235 and 244) sublayers and PHY (e.g., 236 and 245) layers may be terminated in a wireless device (e.g., 110) and a gNB (e.g., 120) on the network side and perform the above services and functions. In an example, RRC (e.g., 232 and 241) may be terminated in a wireless device and a gNB on the network side. In an example, the services and functions of RRC may include: broadcasting system information related to AS and NAS, paging initiated by 5GC or RAN, establishment, maintenance and release of an RRC connection between a UE and a RAN, security functions including key management, establishment, configuration, maintenance and release of a signaling radio bearer (SRB) and a data radio bearer (DRB), mobility functions, QoS management functions, UE measurement reporting and control of reporting, detection of recovery from a radio link failure, and / or delivery of NAS messages from UE to NAS / from NAS to UE. In an example, the NAS control protocol (e.g., 231 and 251) may be terminated in the wireless device and AMF (e.g., 130) on the network side, and may perform functions such as authentication, mobility management between UE and AMF for 3GPP access and non-3GPP access, and session management between UE and SMF for 3GPP access and non-3GPP access.

[0208] In an example, a base station may configure a plurality of logical channels for a wireless device. A logical channel in the plurality of logical channels may correspond to a radio bearer, and the radio bearer may be associated with a QoS requirement. In an example, the base station may configure a logical channel to be mapped to one or more TTI / digits in a plurality of TTI / digits. The wireless device may receive downlink control information (DCI) indicating an uplink grant via a physical downlink control channel (PDCCH). In an example, the uplink grant may be for a first TTI / digit and may indicate an uplink resource for transmission of a transport block. The base station may configure each of the plurality of logical channels, wherein one or more parameters will be used by a logical channel prioritization procedure at a MAC layer of the wireless device. The one or more parameters may include a priority, a prioritized bit rate, and the like. A logical channel in the plurality of logical channels may correspond to one or more buffers including data associated with the logical channel. The logical channel prioritization procedure may allocate uplink resources to one or more first logical channels and / or one or more MAC control elements (CEs) in the plurality of logical channels. One or more first logical channels may be mapped to a first TTI / digit. The MAC layer at the wireless device may multiplex one or more MAC CEs and / or one or more MAC SDUs (e.g., logical channels) in a MAC PDU (e.g., a transport block). In an example, the MAC PDU may include a MAC header including a plurality of MAC subheaders. A MAC subheader in a plurality of MAC subheaders may correspond to a MAC CE or MAC SUD (logical channel) in one or more MAC CEs and / or one or more MAC SDUs. In an example, a MAC CE or a logical channel may be configured with a logical channel identifier (LCID). In an example, the LCID for a logical channel or MAC CE may be fixed / preconfigured. In an example, the LCID for a logical channel or MAC CE may be configured for the wireless device by the base station. The MAC subheader corresponding to the MAC CE or MAC SDU may include an LCID associated with the MAC CE or MAC SDU.

[0209] In an example, a base station may activate and / or deactivate and / or affect one or more processes at a wireless device (e.g., setting values ​​of one or more parameters of one or more processes or starting and / or stopping one or more timers of one or more processes) by using one or more MAC commands. The one or more MAC commands may include one or more MAC control elements. In an example, one or more processes may include activation and / or deactivation of PDCP packet duplication for one or more radio bearers. The base station may transmit a MAC CE including one or more fields, the values ​​of the fields indicating activation and / or deactivation of PDCP duplication for one or more radio bearers. In an example, one or more processes may include channel state information (CSI) transmission on one or more cells. The base station may transmit one or more MAC CEs indicating activation and / or deactivation of CSI transmission on one or more cells. In an example, one or more processes may include activation or deactivation of one or more secondary cells. In an example, the base station may transmit a MAC CE indicating activation or deactivation of one or more secondary cells. In an example, the base station may transmit one or more MAC CEs indicating starting and / or stopping one or more discontinuous reception (DRX) timers at the wireless device. In an example, the base station may transmit one or more MAC CEs indicating one or more timing advance values ​​for one or more timing advance groups (TAGs).

[0210] Figure 3 1 is a block diagram of a base station (base station 1, 120A and base station 2, 120B) and a wireless device 110. The wireless device may be referred to as a UE. The base station may be referred to as a NB, an eNB, a gNB, and / or an ng-eNB. In an example, the wireless device and / or the base station may act as a relay node. Base station 1, 120A may include at least one communication interface 320A (e.g., a wireless modem, an antenna, a wired modem, etc.), at least one processor 321A, and at least one set of program code instructions 323A, which are stored in a non-transitory memory 322A and can be executed by at least one processor 321A. Base station 2, 120B may include at least one communication interface 320B, at least one processor 321B, and at least one set of program code instructions 323B, which are stored in a non-transitory memory 322B and can be executed by at least one processor 321B.

[0211] A base station may include many sectors, for example: 1, 2, 3, 4 or 6 sectors. A base station may include many cells, for example, ranging from 1 to 50 cells or more. Cells may be classified as, for example, primary cells or secondary cells. During radio resource control (RRC) connection establishment / reconstruction / handover, a serving cell may provide NAS (non-access layer) mobility information (e.g., tracking area identifier (TAI)). During RRC connection reconstruction / handover, a serving cell may provide security input. The cell may be referred to as a primary cell (PCell). In the downlink, the carrier corresponding to the PCell may be a DL primary component carrier (PCC), and in the uplink, the carrier may be a UL PCC. Depending on the wireless device capabilities, a secondary cell (SCell) may be configured to form a group of serving cells together with the PCell. In the downlink, the carrier corresponding to the SCell may be a downlink secondary component carrier (DL SCC), and in the uplink, the carrier may be an uplink secondary component carrier (UL SCC). The SCell may or may not have an uplink carrier.

[0212] A physical cell ID and a cell index may be assigned to a cell including a downlink carrier and an optional uplink carrier. A carrier (downlink or uplink) may belong to a cell. A cell ID or a cell index may also identify a downlink carrier or an uplink carrier of a cell (depending on the context in which it is used). In the present disclosure, a cell ID may refer to a carrier ID equivalently, and a cell index may be referred to as a carrier index. In an embodiment, a physical cell ID or a cell index may be assigned to a cell. A synchronization signal transmitted on a downlink carrier may be used to determine the cell ID. An RRC message may be used to determine the cell index. For example, when the present disclosure relates to a first physical cell ID of a first downlink carrier, the present disclosure may mean that the first physical cell ID is used for a cell including a first downlink carrier. The same concept may be applied, for example, to carrier activation. When the present disclosure indicates that a first carrier is activated, the specification may also mean activating a cell including the first carrier.

[0213] The base station may transmit one or more messages (e.g., RRC messages) including multiple configuration parameters of one or more cells to the wireless device. The one or more cells may include at least one primary cell and at least one secondary cell. In an example, the RRC message may be broadcast or unicast to the wireless device. In an example, the configuration parameters may include common parameters and dedicated parameters.

[0214] The services and / or functions of the RRC sublayer may include at least one of the following: broadcasting system information related to AS and NAS; paging initiated by 5GC and / or NG-RAN; establishment, maintenance and / or release of an RRC connection between a wireless device and NG-RAN, which may include at least one of the addition, modification and release of carrier aggregation; or the addition, modification and / or release of a dual connection in NR or between E-UTRA and NR. The services and / or functions of the RRC sublayer may further include at least one of the following security functions: key management; establishment, configuration, maintenance and / or release of signaling radio bearers (SRBs) and / or data radio bearers (DRBs); mobility functions, which may include handover (e.g., intra-NR mobility or inter-RAT mobility) and context transfer; or wireless device cell selection and reselection and control of cell selection and reselection. The services and / or functions of the RRC sublayer may further include at least one of the following: QoS management functions; wireless device measurement configuration / reporting; detection and / or recovery of radio link failures; or delivery of NAS messages from the wireless device to a core network entity (e.g., AMF, Mobility Management Entity (MME)) / from a core network entity to the wireless device.

[0215] The RRC sublayer may support the RRC_Idle state, RRC_Inactive state, and / or RRC_Connected state of the wireless device. In the RRC_Idle state, the wireless device may perform at least one of the following: public land mobile network (PLMN) selection; receiving broadcast system information; cell selection / reselection; monitoring / receiving paging of mobile terminated data initiated by 5GC; paging of mobile terminated data area managed by 5GC; or DRX for CN paging configured by NAS. In the RRC_Inactive state, the wireless device may perform at least one of the following: receiving broadcast system information; cell selection / reselection; monitoring / receiving RAN / CN paging initiated by NG-RAN / 5GC; RAN-based Notification Area (RNA) managed by NG-RAN; or DRX for RAN / CN paging configured by NG-RAN / NAS. In the RRC_Idle state of the wireless device, the base station (e.g., NG-RAN) may maintain a 5GC-NG-RAN connection (both C / U planes) for the wireless device; and / or store a UE AS context for the wireless device. In the RRC_Connected state of the wireless device, the base station (e.g., NG-RAN) may perform at least one of the following: establishing a 5GC-NG-RAN connection (both C / U planes) for the wireless device; storing a UE AS context for the wireless device; transmitting / receiving unicast data to / from the wireless device; or network-controlled mobility based on measurement results received from the wireless device. In the RRC_Connected state of the wireless device, the NG-RAN may know the cell to which the wireless device belongs.

[0216] System information (SI) can be divided into minimum SI and other SI. Minimum SI can be broadcast periodically. Minimum SI may include basic information required for initial access and information for obtaining any other SI that is broadcast periodically or provided on demand, i.e., scheduling information. Other SI may be broadcast, or provided in a dedicated manner, or triggered by the network, or upon request by a wireless device. Minimum SI may be transmitted via two different downlink channels using different messages (e.g., MasterInformationBlock and SystemInformationBlockType1). Another SI may be transmitted via SystemInformationBlockType2. For wireless devices in the RRC_Connected state, dedicated RRC signaling may be used for requesting and delivering other SI. For wireless devices in the RRC_Idle state and / or the RRC_Inactive state, the request may trigger a random access procedure.

[0217] The wireless device may report radio access capability information which may be static. The base station may request what capabilities the wireless device reports based on the band information. When the network allows, the wireless device may send a temporary capability restriction request to signal the limited availability of certain capabilities to the base station (e.g., due to hardware sharing, interference, or overheating). The base station may confirm or deny the request. Temporary capability restrictions may be transparent to the 5GC (e.g., static capabilities may be stored in the 5GC).

[0218] When CA is configured, the wireless device may have an RRC connection with the network. During the RRC connection establishment / reestablishment / handover procedure, one serving cell may provide NAS mobility information, and during RRC connection establishment / handover, one serving cell may provide security input. This cell may be referred to as a PCell. Depending on the capabilities of the wireless device, an SCell may be configured to form a group of serving cells together with the PCell. The configured serving cell group for the wireless device may include one PCell and one or more SCells.

[0219] Reconfiguration, addition and removal of SCells may be performed by RRC. RRC may also add, remove or reconfigure SCells for use with the target PCell during intra-NR handover. When adding a new SCell, dedicated RRC signaling may be used to send all required system information for the SCell, i.e., when in connected mode, the wireless device may not need to obtain broadcast system information directly from the SCell.

[0220] The purpose of the RRC connection reconfiguration procedure may be to modify the RRC connection, (e.g., establish, modify and / or release RBs, perform handover, set, modify and / or release measurements, add, modify and / or release SCells and cell groups). As part of the RRC connection reconfiguration procedure, NAS-specific information may be delivered from the network to the wireless device. The RRCConnectionReconfiguration message may be a command to modify the RRC connection. It may convey information for measurement configuration, mobility control, radio resource configuration (e.g., RBs, MAC primary configuration, and physical channel configuration), including any associated dedicated NAS information and security configuration. If the received RRC connection reconfiguration message contains sCellToReleaseList, the wireless device may perform an SCell release. If the received RRC connection reconfiguration message contains sCellToAddModList, the wireless device may perform an SCell addition or modification.

[0221] The RRC connection establishment (or reestablishment, restoration) procedure may be to establish (or reestablish, restore) an RRC connection. The RRC connection establishment procedure may include SRB1 establishment. The RRC connection establishment procedure may be used to transfer initial NAS dedicated information / messages from the wireless device to the E-UTRAN. The RRCConnectionReesta blishment message may be used to reestablish SRB1.

[0222] The measurement report procedure may be to transfer the measurement results from the wireless device to the NG-RAN. After successful security activation, the wireless device may initiate the measurement report procedure. The measurement results may be transmitted using a measurement report message.

[0223] The wireless device 110 may include at least one communication interface 310 (e.g., a wireless modem, an antenna, etc.), at least one processor 314, and at least one set of program code instructions 316 stored in a non-transitory memory 315 and executable by the at least one processor 314. The wireless device 110 may further include at least one of at least one speaker / microphone 311, at least one keypad 312, at least one display / touchpad 313, at least one power supply 317, at least one global positioning system (GPS) chipset 318, and other peripherals 319.

[0224] The processor 314 of the wireless device 110, the processor 321A of the base station 1 120A, and / or the processor 321B of the base station 2 120B may include at least one of a general purpose processor, a digital signal processor (DSP), a controller, 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, etc. The processor 314 of the wireless device 110, the processor 321A in the base station 1 120A, and / or the processor 321B in the base station 2 120B may perform at least one of signal decoding / processing, data processing, power control, input / output processing, and / or any other functionality that may enable the wireless device 110, the base station 1 120A, and / or the base station 2 120B to operate in a wireless environment.

[0225] The processor 314 of the wireless device 110 may be connected to the speaker / microphone 311, the keypad 312, and / or the display / touchpad 313. The processor 314 may receive user input data from the speaker / microphone 311, the keypad 312, and / or the display / touchpad 313, and / or provide user output data to the speaker / microphone 311, the keypad 312, and / or the display / touchpad 313. The processor 314 in the wireless device 110 may receive power from the power supply 317, and / or may be configured to distribute power to other components in the wireless device 110. The power supply 317 may include at least one of one or more dry cell batteries, solar cells, fuel cells, etc. The processor 314 may be connected to the GPS chipset 318. The GPS chipset 318 may be configured to provide geographic location information of the wireless device 110.

[0226] The processor 314 of the wireless device 110 may further be connected to other peripherals 319, which may include one or more software and / or hardware modules that provide additional features and / or functionality. For example, the peripherals 319 may include at least one of an accelerometer, a satellite transceiver, a digital camera, a universal serial bus (USB) port, a hands-free headset, a frequency modulation (FM) radio unit, a media player, an Internet browser, etc.

[0227] The communication interface 320A of base station 1, 120A and / or the communication interface 320B of base station 2, 120B may be configured to communicate with the communication interface 310 of the wireless device 110 via the wireless link 330A and / or the wireless link 330B, respectively. In an example, the communication interface 320A of base station 1, 120A may communicate with the communication interface 320B of base station 2 and other RAN and core network nodes.

[0228] The wireless link 330A and / or the wireless link 330B may include at least one of a bidirectional link and / or a directional link. The communication interface 310 of the wireless device 110 may be configured to communicate with the communication interface 320A of the base station 1 120A and / or with the communication interface 320B of the base station 2 120B. The base station 1 120A and the wireless device 110 and / or the base station 2 120B and the wireless device 110 may be configured to send and receive transport blocks via the wireless link 330A and / or via the wireless link 330B, respectively. The wireless link 330A and / or the wireless link 330B may use at least one frequency carrier. According to some different aspects of the embodiments, a transceiver may be used. A transceiver may be a device that includes both a transmitter and a receiver. A transceiver may be used in devices such as wireless devices, base stations, relay nodes, etc. In Figure 4A , Figure 4B , Figure 4C , Figure 4D , Figure 6 , Fig. 7A , Figure 7B , Figure 8 Example embodiments of radio technologies implemented in the communication interfaces 310, 320A, 320B and wireless links 330A, 330B are shown in EMBODIMENTS and related text.

[0229] In an example, other nodes in the wireless network (eg, AMF, UPF, SMF, etc.) may include one or more communication interfaces, one or more processors, and a memory for storing instructions.

[0230] A node (e.g., a wireless device, a base station, an AMF, an SMF, an UPF, a server, a switch, an antenna, etc.) may include one or more processors and a memory storing instructions that, when executed by the one or more processors, cause the node to perform certain processes and / or functions. Example embodiments may implement operations of single carrier and / or multi-carrier communications. Other example embodiments may include a non-transitory tangible computer-readable medium that includes instructions that can be executed by one or more processors to cause operations of single carrier and / or multi-carrier communications. Other example embodiments may include an article of manufacture that includes a non-transitory tangible computer-readable machine-accessible medium on which instructions are encoded for enabling programmable hardware to enable a node to implement operations of single carrier and / or multi-carrier communications. A node may include a processor, a memory, an interface, etc.

[0231] The interface may include at least one of a hardware interface, a firmware interface, a software interface, and / or a combination thereof. The hardware interface may include connectors, wires, electronic devices such as drivers, amplifiers, etc. The software interface may include code stored in a memory device to implement a protocol, a protocol layer, a communication device, a device driver, a combination thereof, etc. The firmware interface may include a combination of embedded hardware and code stored in and / or in communication with a memory device to implement a connection, an electronic device operation, a protocol, a protocol layer, a communication driver, a device driver, a hardware operation, a combination thereof, etc.

[0232] Figure 4A , Figure 4B , Figure 4C and Figure 4D is an example diagram of uplink and downlink signal transmission according to aspects of an embodiment of the present disclosure. Figure 4AAn example uplink transmitter for at least one physical channel is shown. A baseband signal representing a physical uplink shared channel may perform one or more functions. The one or more functions may include at least one of: scrambling; modulating scrambled bits to generate complex-valued symbols; mapping complex-valued modulation symbols to one or several transmission layers; transform pre-decoding to generate complex-valued symbols; pre-decoding of complex-valued symbols; mapping of pre-decoded complex-valued symbols to resource elements; generating a complex-valued time-domain single carrier frequency division multiple access (SC-FDMA) or CP-OFDM signal for an antenna port; and the like. In an example, when transform pre-decoding is enabled, an SC-FDMA signal for uplink transmission may be generated. In an example, when transform pre-decoding is not enabled, the uplink transmission may be performed by Figure 4A A CP-OFDM signal is generated for uplink transmission. These functions are shown as examples, and it is contemplated that other mechanisms may be implemented in various embodiments.

[0233] Example structures for modulation and up-conversion of the carrier frequency of a complex-valued SC-FDMA or CP-OFDM baseband signal and / or a complex-valued physical random access channel (PRACH) baseband signal for an antenna port are shown in Figure 4B In. Filtering can be used before transmission.

[0234] Figure 4C An example structure for downlink transmission is shown in . A baseband signal representing a downlink physical channel may perform one or more functions. The one or more functions may include: scrambling the decoded bits in a codeword to be transmitted on a physical channel; modulating the scrambled bits to generate complex-valued modulation symbols; mapping the complex-valued modulation symbols to one or several transmission layers; pre-decoding of complex-valued modulation symbols on layers for transmission on antenna ports; mapping complex-valued modulation symbols for antenna ports to resource elements; generating complex-valued time-domain OFDM signals for antenna ports; and the like. These functions are shown as examples, and it is contemplated that other mechanisms may be implemented in various embodiments.

[0235] In an example, a gNB may transmit a first symbol and a second symbol to a wireless device on an antenna port. The wireless device may infer a channel (e.g., fading gain, multipath delay, etc.) used to communicate the second symbol on the antenna port from the channel used to communicate the first symbol on the antenna port. In an example, the first antenna port and the second antenna port may be quasi-co-located if one or more large-scale properties of a channel on which the first symbol on the first antenna port is communicated may be inferred from a channel on which the second symbol on the second antenna port is communicated. The one or more large-scale properties may include at least one of: delay spread; Doppler spread; Doppler shift; average gain; average delay; and / or spatial receive (Rx) parameters.

[0236] Example modulation and up-conversion of the carrier frequency of a complex-valued OFDM baseband signal for an antenna port Figure 4D Filtering can be applied before emission.

[0237] Figure 5A is a diagram of an example uplink channel map and an example uplink physical signal. Figure 5B is a diagram of an example downlink channel mapping and downlink physical signals. In an example, the physical layer may provide one or more information transfer services to the MAC and / or one or more higher layers. For example, the physical layer may provide the one or more information transfer services to the MAC via one or more transport channels. The information transfer service may indicate the manner and characteristics of transferring data over the radio interface.

[0238] In an example embodiment, the radio network may include one or more downlink and / or uplink transmission channels. Figure 5A The figure in shows an example uplink transport channel including an uplink shared channel (UL-SCH) 501 and a random access channel (RACH) 502. Figure 5B The figure in shows an example downlink transport channel including a downlink shared channel (DL-SCH) 511, a paging channel (PCH) 512, and a broadcast channel (BCH) 513. The transport channels can be mapped to one or more corresponding physical channels. For example, UL-SCH 501 can be mapped to a physical uplink shared channel (PUSCH) 503. RACH 502 can be mapped to PRACH 505. DL-SCH 511 and PCH 512 can be mapped to a physical downlink shared channel (PDSCH) 514. BCH 513 can be mapped to a physical broadcast channel (PBCH) 516.

[0239] There may be one or more physical channels without corresponding transport channels. The one or more physical channels may be used for uplink control information (UCI) 509 and / or downlink control information (DCI) 517. For example, a physical uplink control channel (PUCCH) 504 may carry UCI 509 from a UE to a base station. For example, a physical downlink control channel (PDCCH) 515 may carry DCI 517 from a base station to a UE. When UCI 509 and PUSCH 503 transmissions may overlap at least partially in a time slot, NR may support UCI 509 multiplexing in PUSCH 503. UCI 509 may include at least one of CSI, acknowledgment (ACK) / negative acknowledgment (NACK), and / or a scheduling request. DCI 517 on PDCCH 515 may indicate at least one of: one or more downlink assignments and / or one or more uplink scheduling grants.

[0240] In the uplink, the UE may transmit one or more reference signals (RS) to the base station. For example, the one or more RSs may be at least one of a demodulation-RS (DM-RS) 506, a phase tracking-RS (PT-RS) 507, and / or a sounding RS (SRS) 508. In the downlink, the base station may transmit (e.g., unicast, multicast, and / or broadcast) one or more RSs to the UE. For example, the one or more RSs may be at least one of a primary synchronization signal (PSS) / secondary synchronization signal (SSS) 521, a CSI-RS 522, a DM-RS 523, and / or a PT-RS 524.

[0241] In an example, the UE may transmit one or more uplink DM-RS 506 to the base station for channel estimation, for example, for coherent demodulation of one or more uplink physical channels (e.g., PUSCH 503 and / or PUCCH 504). For example, the UE may transmit at least one uplink DM-RS 506 to the base station using PUSCH 503 and / or PUCCH 504, wherein the at least one uplink DM-RS 506 may span the same frequency range as the corresponding physical channel. In an example, the base station may configure the UE with one or more uplink DM-RS configurations. At least one DM-RS configuration may support a front-loaded DM-RS pattern. The front-loaded DM-RS may be mapped on one or more OFDM symbols (e.g., 1 or 2 adjacent OFDM symbols). One or more additional uplink DM-RS may be configured to be transmitted at one or more symbols of PUSCH and / or PUCCH. The base station may semi-statistically configure the UE with a maximum number of front-loaded DM-RS symbols for PUSCH and / or PUCCH. For example, the UE may schedule single-symbol DM-RS and / or dual-symbol DM-RS based on the maximum number of front-loaded DM-RS symbols, wherein the base station may configure the UE with one or more additional uplink DM-RS for PUSCH and / or PUCCH. The new radio network may, for example, support a common DM-RS structure for DL ​​and UL at least for CP-OFDM, wherein the DM-RS position, DM-RS pattern and / or scrambling sequence may be the same or different.

[0242] In an example, whether uplink PT-RS 507 exists may depend on RRC configuration. For example, the presence of uplink PT-RS may be UE-specifically configured. For example, the presence and / or pattern of uplink PT-RS 507 in scheduled resources may be UE-specifically configured by a combination of RRC signaling and / or association with one or more parameters (e.g., modulation and coding scheme (MCS)) for other purposes that may be indicated by DCI. When configured, the dynamic presence of uplink PT-RS 507 may be associated with one or more DCI parameters including at least MCS. The radio network may support multiple uplink PT-RS densities defined in the time / frequency domain. When present, the frequency domain density may be associated with at least one configuration of the scheduled bandwidth. The UE may use the same precoding for DMRS ports and PT-RS ports. The number of PT-RS ports may be less than the number of DM-RS ports in the scheduled resources. For example, uplink PT-RS 507 may be limited to the scheduled time / frequency duration of the UE.

[0243] In an example, the UE may transmit SRS 508 to a base station for channel state estimation to support uplink channel-dependent scheduling and / or link adaptation. For example, the SRS 508 transmitted by the UE may allow the base station to estimate the uplink channel state of one or more different frequencies. The base station scheduler may use the uplink channel state to assign one or more resource blocks of high quality for uplink PUSCH transmission from the UE. The base station may semi-statistically configure the UE using one or more SRS resource sets. For the SRS resource set, the base station may configure the UE using one or more SRS resources. The SRS resource set applicability may be configured by a higher layer (e.g., RRC) parameter. For example, when a higher layer parameter indicates beam management, SRS resources in each of one or more SRS resource sets may be transmitted at a certain moment. The UE may transmit one or more SRS resources in different SRS resource sets at the same time. The new radio network may support non-periodic, periodic, and / or semi-persistent SRS transmissions. The UE may transmit SRS resources based on one or more trigger types, wherein the one or more trigger types may include higher layer signaling (e.g., RRC) and / or one or more DCI formats (e.g., at least one DCI format may be used for the UE to select at least one of one or more configured SRS resource sets. SRS trigger type 0 may refer to SRS triggered based on higher layer signaling. SRS trigger type 1 may refer to SRS triggered based on one or more DCI formats. In an example, when PUSCH 503 and SRS 508 are transmitted in the same time slot, the UE may be configured to transmit SRS 508 after transmission of PUSCH 503 and corresponding uplink DM-RS 506.

[0244] In an instance, the base station may semi-statistically configure the UE using one or more SRS configuration parameters indicating at least one of: an SRS resource configuration identifier, a number of SRS ports, a time domain behavior of the SRS resource configuration (e.g., an indication of periodic, semi-persistent, or aperiodic SRS), a slot (mini-slot and / or subframe) level periodicity and / or offset of periodic and / or aperiodic SRS resources, a number of OFDM symbols in an SRS resource, a starting OFDM symbol of an SRS resource, an SRS bandwidth, a frequency hopping bandwidth, a cyclic shift, and / or an SRS sequence ID.

[0245] In an example, in the time domain, the SS / PBCH block may include one or more OFDM symbols within the SS / PBCH block (e.g., 4 OFDM symbols numbered in increasing order from 0 to 3). The SS / PBCH block may include PSS / SSS 521 and PBCH 516. In an example, in the frequency domain, the SS / PBCH block may include one or more consecutive subcarriers within the SS / PBCH block (e.g., 240 consecutive subcarriers, the subcarriers are numbered in increasing order from 0 to 239). For example, PSS / SSS 521 may occupy 1 OFDM symbol and 127 subcarriers. For example, PBCH 516 may span 3 OFDM symbols and 240 subcarriers. The UE may assume that one or more SS / PBCH blocks transmitted using the same block index may be quasi-co-located, for example, with respect to Doppler spread, Doppler shift, average gain, average delay, and spatial Rx parameters. The UE may not assume quasi-co-location of other SS / PBCH block transmissions. The periodicity of the SS / PBCH blocks may be configured by the radio network (e.g., via RRC signaling), and the subcarrier spacing may determine the one or more time locations at which the SS / PBCH blocks may be sent. In an example, the UE may assume a band-specific subcarrier spacing for the SS / PBCH blocks unless the radio network has configured the UE to assume a different subcarrier spacing.

[0246] In an example, a downlink CSI-RS 522 may be used for the UE to obtain channel state information. The radio network may support periodic, aperiodic and / or semi-persistent transmission of the downlink CSI-RS 522. For example, the base station may semi-statistically configure and / or reconfigure the UE using the periodic transmission of the downlink CSI-RS 522. The configured CSI-RS resources may be activated / deactivated. For semi-persistent transmission, the activation and / or deactivation of the CSI-RS resources may be dynamically triggered. In an example, the CSI-RS configuration may include one or more parameters indicating the number of at least antenna ports. For example, the base station may configure the UE using 32 ports. The base station may semi-statistically configure the UE using one or more CSI-RS resource sets. One or more CSI-RS resources may be allocated to one or more UEs from one or more CSI-RS resource sets. For example, the base station may semi-statistically configure one or more parameters indicating CSI RS resource mapping, such as the time domain position of one or more CSI-RS resources, the bandwidth of the CSI-RS resources, and / or periodicity. In an example, the UE may be configured to use the same OFDM symbol for the downlink CSI-RS 522 and the control resource set (core set) when the downlink CSI-RS 522 and the core set are quasi-co-located in space and the resource elements associated with the downlink CSI-RS 522 are outside the PRB configured for the core set. In an example, the UE may be configured to use the same OFDM symbol for the downlink CSI-RS 522 and the SSB / PBCH when the downlink CSI-RS 522 and the SSB / PBCH are quasi-co-located in space and the resource elements associated with the downlink CSI-RS 522 are outside the PRB configured for the SSB / PBCH.

[0247] In an example, the UE may transmit one or more downlink DM-RS 523 to a base station for channel estimation, e.g., for coherent demodulation of one or more downlink physical channels (e.g., PDSCH 514). For example, the radio network may support one or more variable and / or configurable DM-RS patterns for data demodulation. At least one downlink DM-RS configuration may support a front-load DM-RS pattern. The front-load DM-RS may be mapped on one or more OFDM symbols (e.g., 1 or 2 adjacent OFDM symbols). The base station may semi-statistically configure the UE with a maximum number of front-load DM-RS symbols for PDSCH 514. For example, the DM-RS configuration may support one or more DM-RS ports. For example, for single-user-MIMO, the DM-RS configuration may support at least 8 orthogonal downlink DM-RS ports. For example, for multi-user-MIMO, the DM-RS configuration may support 12 orthogonal downlink DM-RS ports. The radio network may support a common DM-RS structure for DL ​​and UL, for example, at least for CP-OFDM, where the DM-RS positions, DM-RS patterns and / or scrambling sequences may be the same or different.

[0248] In an example, whether a downlink PT-RS 524 exists may depend on an RRC configuration. For example, the presence of a downlink PT-RS 524 may be UE-specifically configured. For example, the presence and / or pattern of a downlink PT-RS 524 in a scheduled resource may be UE-specifically configured by a combination of RRC signaling and / or association with one or more parameters (e.g., MCS) for other purposes that may be indicated by a DCI. When configured, the dynamic presence of a downlink PT-RS 524 may be associated with one or more DCI parameters including at least an MCS. A radio network may support multiple PT-RS densities defined in a time / frequency domain. When present, a frequency domain density may be associated with at least one configuration of a scheduled bandwidth. The UE may use the same precoding for a DMRS port and a PT-RS port. The number of PT-RS ports may be less than the number of DM-RS ports in the scheduled resource. For example, a downlink PT-RS 524 may be limited to a scheduled time / frequency duration of the UE.

[0249] Figure 6 is a diagram depicting an example frame structure of a carrier according to aspects of an embodiment of the present disclosure. A multi-carrier OFDM communication system may include one or more carriers, for example, ranging from 1 to 32 carriers in the case of carrier aggregation, or ranging from 1 to 64 carriers in the case of dual connectivity. Different radio frame structures (e.g., for FDD and for TDD duplexing schemes) may be supported. Figure 6An example frame structure is shown. Downlink and uplink transmissions may be organized into radio frames 601. In this example, the radio frame duration is 10 ms. In this example, the 10 ms radio frame 601 may be divided into 10 equally sized subframes 602 with a duration of 1 ms. A subframe may include one or more time slots (e.g., time slots 603 and 605), depending on the subcarrier spacing and / or CP length. For example, subframes with 15 kHz, 30 kHz, 60 kHz, 120 kHz, 240 kHz, and 480 kHz subcarrier spacing may include one, two, four, eight, sixteen, and thirty-two time slots, respectively. Figure 6 In the embodiment of the present invention, a subframe can be divided into two equally sized time slots 603 with a duration of 0.5 ms. For example, at an interval of 10 ms, 10 subframes can be used for downlink transmission and 10 subframes can be used for uplink transmission. Uplink and downlink transmissions are separated in the frequency domain. A time slot can contain multiple OFDM symbols 604. The number of OFDM symbols 604 in a time slot 605 can depend on the cyclic prefix length. For example, for the same subcarrier spacing of up to 480 kHz with normal CP, a time slot can be 14 OFDM symbols. For the same subcarrier spacing of 60 kHz with extended CP, a time slot can be 12 OFDM symbols. A time slot can contain a downlink, an uplink, or a downlink part and an uplink part, etc.

[0250] Fig. 7A700. The diagram depicts an example OFDM subcarrier set according to aspects of an embodiment of the present disclosure. In this example, a gNB may communicate with a wireless device using a carrier having an example channel bandwidth 700. The arrows in the diagram may depict subcarriers in a multi-carrier OFDM system. The OFDM system may use techniques such as OFDM techniques, SC-FDMA techniques, etc. In the example, arrows 701 show subcarriers that transmit information symbols. In the example, a subcarrier spacing 702 between two consecutive subcarriers in a carrier may be any one of 15KHz, 30KHz, 60KHz, 120KHz, 240KHz, etc. In the example, different subcarrier spacings may correspond to different transmission numbers. In the example, the transmission number may include at least: a digital index; a value of the subcarrier spacing; a type of cyclic prefix (CP). In the example, the gNB may transmit to / receive from a UE on several subcarriers 703 in the carrier. In the example, due to guard bands 704 and 705, the bandwidth occupied by several subcarriers 703 (transmission bandwidth) may be less than the channel bandwidth 700 of the carrier. In an example, guard bands 704 and 705 may be used to reduce interference to one or more adjacent carriers. The number of subcarriers in a carrier (transmit bandwidth) may depend on the channel bandwidth and subcarrier spacing of the carrier. For example, for a carrier with a 20 MHz channel bandwidth and a 15 KHz subcarrier spacing, the transmit bandwidth may be the number of 1024 subcarriers.

[0251] In an example, when CA configuration is utilized, the gNB and wireless device may communicate with multiple CCs. In an example, if CA is supported, different component carriers may have different bandwidths and / or subcarrier spacings. In an example, the gNB may transmit a first type of service to the UE on a first component carrier. The gNB may transmit a second type of service to the UE on a second component carrier. Different types of services may have different service requirements (e.g., data rate, latency, reliability), which may be suitable for transmission via different component carriers with different subcarrier spacings and / or bandwidths. Figure 7B An example embodiment is shown. The first component carrier may include a first number of subcarriers 706 having a first subcarrier spacing 709. The second component carrier may include a second number of subcarriers 707 having a second subcarrier spacing 710. The third component carrier may include a third number of subcarriers 708 having a third subcarrier spacing 711. The carriers in a multi-carrier OFDM communication system may be contiguous carriers, non-contiguous carriers, or a combination of contiguous and non-contiguous carriers.

[0252] Figure 8801. In an example, a carrier may have a transmission bandwidth 801. In an example, a resource grid may be in a frequency domain 802 and a time domain 803 structure. In an example, a resource grid may include a first number of OFDM symbols and a second number of resource blocks in a subframe, starting from a common resource block for transmitting a number and a carrier indicated by higher layer signaling (e.g., RRC signaling). In an example, in a resource grid, a resource unit identified by a subcarrier index and a symbol index may be a resource element 805. In an example, depending on the number associated with the carrier, a subframe may include a first number of OFDM symbols 807. For example, when the subcarrier spacing of the number of the carrier is 15KHz, the subframe may have 14 OFDM symbols for the carrier. When the subcarrier spacing of the number is 30KHz, the subframe may have 28 OFDM symbols. When the subcarrier spacing of the number is 60Khz, the subframe may have 56 OFDM symbols, etc. In an example, the second number of resource blocks included in the resource grid of the carrier may depend on the bandwidth and number of carriers.

[0253] like Figure 8 As shown, resource block 806 may include 12 subcarriers. In an example, multiple resource blocks may be grouped into resource block groups (RBGs) 804. In an example, the size of the RBG may depend on at least one of: an RRC message indicating an RBG size configuration; the size of the carrier bandwidth; or the size of a bandwidth portion of the carrier. In an example, the carrier may include multiple bandwidth portions. A first bandwidth portion of the carrier may have a different frequency location and / or bandwidth than a second bandwidth portion of the carrier.

[0254] In an example, the gNB may transmit downlink control information including downlink or uplink resource block assignments to the wireless device. The base station may transmit to or receive from the wireless device a data packet (e.g., a transport block) scheduled and transmitted via one or more resource blocks and one or more time slots according to the downlink control information and / or parameters in the RRC message. In an example, a starting symbol of a first time slot relative to the one or more time slots may be indicated to the wireless device. In an example, the gNB may transmit to or receive from the wireless device a data packet scheduled on one or more RBGs and one or more time slots.

[0255] In an example, the gNB may transmit downlink control information including a downlink assignment to the wireless device via one or more PDCCHs. The downlink assignment may include parameters indicating at least a modulation and coding format; a resource allocation; and / or HARQ information related to the DL-SCH. In an example, the resource allocation may include parameters for a resource block allocation; and / or a time slot allocation. In an example, the gNB may dynamically allocate resources to the wireless device via a cell-radio network temporary identifier (C-RNTI) on one or more PDCCHs. The wireless device may monitor the one or more PDCCHs to find possible allocations when its downlink reception is enabled. When the one or more PDCCHs are successfully detected, the wireless device may receive one or more downlink data packets on one or more PDSCHs scheduled by the one or more PDCCHs.

[0256] In an example, the gNB may allocate a configuration scheduling (CS) resource for downlink transmission to the wireless device. The gNB may transmit one or more RRC messages indicating the periodicity of the CS grant. The gNB may transmit the DCI via a PDCCH addressed to a configuration scheduling-RNTI (CS-RNTI) that activates the CS resources. The DCI may include a parameter indicating that the downlink grant is a CS grant. The CS grant may be implicitly reused according to the periodicity defined by the one or more RRC messages until deactivated.

[0257] In an example, the gNB may transmit downlink control information including an uplink grant to the wireless device via one or more PDCCHs. The uplink grant may include parameters indicating at least a modulation and code format; a resource allocation; and / or HARQ information related to the UL-SCH. In an example, the resource allocation may include parameters for a resource block allocation; and / or a time slot allocation. In an example, the gNB may dynamically allocate resources to the wireless device via a C-RNTI on one or more PDCCHs. The wireless device may monitor the one or more PDCCHs for possible resource allocations. Upon successful detection of the one or more PDCCHs, the wireless device may transmit one or more uplink data packets via one or more PUSCHs scheduled by the one or more PDCCHs.

[0258] In an example, the gNB may allocate CS resources for uplink data transmission to the wireless device. The gNB may transmit one or more RRC messages indicating the periodicity of the CS grant. The gNB may transmit a DCI via a PDCCH addressed to the CS-RNTI that activated the CS resources. The DCI may include a parameter indicating that the uplink grant is a CS grant. The CS grant may be implicitly reused according to the periodicity defined by the one or more RRC messages until deactivated.

[0259] In an example, a base station may transmit DCI / control signaling via a PDCCH. DCI may adopt a format in a variety of formats. DCI may include downlink and / or uplink scheduling information (e.g., resource allocation information, HARQ related parameters, MCS), a request for CSI (e.g., aperiodic CQI report), a request for SRS, an uplink power control command for one or more cells, one or more timing information (e.g., TB transmission / reception timing, HARQ feedback timing, etc.), etc. In an example, DCI may indicate an uplink grant including transmission parameters for one or more transport blocks. In an example, DCI may indicate a downlink assignment indicating parameters for receiving one or more transport blocks. In an example, a base station may use DCI to initiate contention-free random access at a wireless device. In an example, a base station may transmit a DCI including a slot format indicator (SFI) that notifies a slot format. In an example, a base station may transmit a DCI including a preemptive indication of a notification PRB and / or OFDM symbol, wherein the UE may assume that there is no transmission intended for the UE. In an example, a base station may transmit a DCI for group power control of a PUCCH or PUSCH or SRS. In an example, the DCI may correspond to an RNTI. In an example, a wireless device may obtain an RNTI (e.g., C-RNTI) in response to completing initial access. In an example, a base station may configure an RNTI (e.g., CS-RNTI, TPC-CS-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI, TPC-SRS-RNTI) for wireless. In an example, a wireless device may calculate an RNTI (e.g., a wireless device may calculate an RA-RNTI based on resources used to transmit a preamble). In an example, the RNTI may have a preconfigured value (e.g., P-RNTI or SI-RNTI). In an example, a wireless device may monitor a group common search space, which may be used by a base station to transmit a DCI intended for a group of UEs. In an example, a group common DCI may correspond to an RNTI configured for a group of UEs. In an example, a wireless device may monitor a UE-specific search space. In an example, the UE-specific DCI may correspond to the RNTI configured for the wireless device.

[0260] The NR system may support single beam operation and / or multi-beam operation. In multi-beam operation, the base station may perform downlink beam sweeping to provide coverage for a common control channel and / or downlink SS block that may include at least PSS, SSS and / or PBCH. The wireless device may use one or more RSs to measure the quality of the beam to the link. One or more SS blocks, or one or more CSI-RS resources associated with a CSI-RS resource index (CRI), or one or more DM-RSs of the PBCH may be used as RSs for measuring the quality of the beam to the link. The quality of the beam to the link may be defined as a reference signal received power (RSRP) value, or a reference signal received quality (RSRQ) value, and / or a CSI value measured on the RS resource. The base station may indicate whether the RS resource used to measure the quality of the beam to the link is quasi-co-located (QCL) with the DM-RS of the control channel. When the channel characteristics of the transmission from the RS to the wireless device and the transmission from the control channel to the wireless device are similar or identical under the configured criteria, the RS resources and DM-RS of the control channel may be referred to as QCL. In multi-beam operation, a wireless device may perform uplink beam sweeping to access a cell.

[0261] In one example, the wireless device may be configured to monitor PDCCH on one or more beam pair links simultaneously depending on the capabilities of the wireless device. This may increase robustness against beam pair link blocking. The base station may transmit one or more messages to configure the wireless device to monitor PDCCH on one or more beam pair links in different PDCCH OFDM symbols. For example, the base station may transmit higher layer signaling (e.g., RRC signaling) or MAC CE, which includes parameters for Rx beam settings of the wireless device for monitoring PDCCH on one or more beam pair links. The base station may transmit an indication of the spatial QCL assumption between the DL RS antenna port (e.g., cell-specific CSI-RS, or wireless device-specific CSI-RS, or SS block, or PBCH with or without DM-RS of PBCH) and the DL RS antenna port for demodulating the DL control channel. The signaling for the beam indication for PDCCH may be MAC CE signaling, or RRC signaling, or DCI signaling, or canonical transparent and / or implicit methods, and combinations of these signaling methods.

[0262] For reception of unicast DL data channels, the base station may indicate spatial QCL parameters between the DL RS antenna ports and the DM-RS antenna ports of the DL data channel. The base station may transmit a DCI (e.g., a downlink grant) including information indicating the RS antenna ports. The information may indicate the RS antenna ports that may be QCLed with the DM-RS antenna ports. Different sets of DM-RS antenna ports for DL ​​data channels may be indicated as different sets of QCLed with the RS antenna ports.

[0263] Fig.9A and Fig. 9B Packet flows employing multiple connections (eg, dual connection, multiple connections, tight interworking, etc.) are shown. Fig.9A is an example diagram of a protocol structure for a wireless device 110 (eg, UE) with CA and / or multiple connections in accordance with aspects of the embodiments. Fig. 9B 1 is an example diagram of a protocol structure of multiple base stations with CA and / or multiple connections according to aspects of an embodiment. The multiple base stations may include a master node MN 1130 (e.g., a master node, a master base station, a master gNB, a master eNB, etc.) and a secondary node SN 1150 (e.g., a secondary node, a secondary base station, a secondary gNB, a secondary eNB, etc.). The master node 1130 and the secondary node 1150 may work together to communicate with the wireless device 110.

[0264] When multiple connections are configured for the wireless device 110, the wireless device 110, which can support multiple receive / transmit functions in the RRC connection state, can be configured to utilize radio resources provided by multiple schedulers of multiple base stations. Multiple base stations can be interconnected through non-ideal or ideal backhauls (e.g., Xn interface, X2 interface, etc.). The base stations involved in the multiple connections for a certain wireless device can perform at least one of two different roles: the base station can act as a primary base station or a secondary base station. In multiple connections, the wireless device can be connected to a primary base station and one or more secondary base stations. In an example, a primary base station (e.g., MN 1130) can provide a wireless device (e.g., wireless device 110) with a primary cell group (MCG) including a primary cell and / or one or more secondary cells. A secondary base station (e.g., SN 1150) can provide a secondary cell group (SCG) including a primary secondary cell (PSCell) and / or one or more secondary cells for a wireless device (e.g., wireless device 110).

[0265] In multiple connections, the radio protocol architecture used for the bearer may depend on how the bearer is set up. In an example, three different types of bearer setting options may be supported: MCG bearer, SCG bearer, and / or separate bearer. The wireless device may receive / transmit packets carried by the MCG via one or more cells of the MCG, and / or may receive / transmit packets carried by the SCG via one or more cells of the SCG. Multiple connections may also be described as having at least one bearer that is configured to use radio resources provided by a secondary base station. In some example embodiments, multiple connections may or may not be configured / implemented.

[0266] In an example, a wireless device (e.g., wireless device 110) may transmit and / or receive packets carried by the MCG via an SDAP layer (e.g., SDAP 1110), a PDCP layer (e.g., NR PDCP 1111), an RLC layer (e.g., MN RLC 1114), and a MAC layer (e.g., MN MAC 1118); transmit and / or receive packets carried by the separated MCG via an SDAP layer (e.g., SDAP 1110), a PDCP layer (e.g., NR PDCP 1112), one of the primary or secondary RLC layers (e.g., MN RLC 1115, SN RLC 1116), and one of the primary or secondary MAC layers (e.g., MN MAC 1118, SN MAC 1119); and / or transmit and / or receive packets carried by the separated MCG via an SDAP layer (e.g., SDAP 1110), a PDCP layer (e.g., NR PDCP 1113), an RLC layer (e.g., SN RLC 1117), and a MAC layer (e.g., MN MAC 1118). 1119) to transmit and / or receive packets carried by SCG.

[0267] In an example, a primary base station (e.g., MN 1130) and / or a secondary base station (e.g., SN 1150) may transmit / receive packets carried by the MCG via a primary or secondary node SDAP layer (e.g., SDAP 1120, SDAP 1140), a primary or secondary node PDCP layer (e.g., NR PDCP 1121, NR PDCP 1142), a primary node RLC layer (e.g., MN RLC 1124, MN RLC 1125), and a primary node MAC layer (e.g., MN MAC 1128); and may transmit / receive packets carried by the MCG via a primary or secondary node SDAP layer (e.g., SDAP 1120, SDAP 1140), a primary or secondary node PDCP layer (e.g., NR PDCP 1122, NR PDCP 1143), a secondary node RLC layer (e.g., SN RLC 1146, SN RLC 1147), and a secondary node MAC layer (e.g., SN MAC 1128). 1148) transmits / receives packets carried by SCG; transmits / receives packets carried separately via the primary or secondary node SDAP layer (e.g., SDAP 1120, SDAP 1140), the primary or secondary node PDCP layer (e.g., NR PDCP 1123, NR PDCP 1141), the primary or secondary node RLC layer (e.g., MN RLC 1126, SN RLC 1144, SNRLC1145, MN RLC 1127) and the primary or secondary node MAC layer (e.g., MN MAC 1128, SN MAC 1148).

[0268] In multiple connections, the wireless device may configure multiple MAC entities: one MAC entity for the primary base station (e.g., MN MAC 1118), and other MAC entities for the secondary base stations (e.g., SN MAC 1119). In multiple connections, the configured service cell set for the wireless device may include two subsets: an MCG including service cells of the primary base station, and an SCG including service cells of the secondary base stations. For SCG, one or more of the following configurations may apply: at least one cell of the SCG has a configured UL CC, and at least one cell of the SCG, referred to as a primary secondary cell (PSCell, PCell of the SCG, or sometimes referred to as PCell) is configured with PUCCH resources; when the SCG is configured, there may be at least one SCG bearer or one split bearer; after a physical layer problem or random access problem is detected on the PSCell, or after a number of NR RLC retransmissions associated with the SCG have been reached, or after an access problem is detected on the PSCell during SCG addition or SCG change: the RRC connection reestablishment procedure may not be triggered, UL transmission to the cells of the SCG may be stopped, the primary base station may be notified of the SCG failure type by the wireless device, and for a split bearer, DL data delivery on the primary base station may be maintained; NR may be configured for a split bearer RLC Acknowledged Mode (AM) bearer; PCell and / or PSCell cannot be contacted for activation; SCG change procedures may be used to change PSCell (e.g., using security key change and RACH procedures); and / or bearer type change between separate bearer and SCG bearer, or simultaneous configuration of SCG and separate bearer may or may not be supported.

[0269] Regarding the interaction between the primary base station and the secondary base station for multiple connections, one or more of the following may be applied: the primary base station and / or the secondary base station may maintain the RRM measurement configuration of the wireless device; the primary base station may (for example, based on the received measurement report, traffic conditions and / or carrier type) decide to request the secondary base station to provide additional resources (for example, service cells) for the wireless device; upon receiving the request from the primary base station, the secondary base station may create / modify a container, which may result in the configuration of additional service cells for the wireless device (or determine that the secondary base station has no available resources to do so); for UE capability coordination, the primary base station may provide (partial) AS configuration and UE capabilities to the secondary base station; the primary base station and the secondary base station may exchange information about UE configuration by adopting an RRC container (inter-node message) carried via an Xn message; the secondary base station may initiate reconfiguration of the secondary base station's existing service cell (for example, towards the PUCCH of the secondary base station); the secondary base station may decide which cell is the PSCell within the SCG; the primary base station may change or not change the content of the RRC configuration provided by the secondary base station; adding and / or re-adding a secondary base station to the SCG In the case of adding an SCell, the primary base station can provide the most recent (or latest) measurement results for the SCG cell; the primary base station and the secondary base station can receive information about SFN and / or each other's subframe offsets from OAM and / or via the Xn interface (for example, for the purpose of DRX alignment and / or identification of measurement gaps). In an example, when a new SCG SCell is added, dedicated RRC signaling can be used to send the required system information of the cell of the CA, except for the SFN obtained from the MIB of the PSCell of the SCG.

[0270] Fig.10 is an example diagram of a random access procedure. One or more events may trigger the random access procedure. For example, the one or more events may be at least one of: initial access from RRC_IDLE, RRC connection reestablishment procedure, handover, DL or UL data arrival during RRC_CONNECTED when the UL synchronization state is asynchronous, transition from RRC_Inactive, and / or a request for other system information. For example, a PDCCH command, a MAC entity, and / or a beam failure indication may initiate the random access procedure.

[0271] In an example embodiment, the random access procedure may be at least one of a contention-based random access procedure and a contention-free random access procedure. For example, the contention-based random access procedure may include one or more Msg 1 1220 transmissions, one or more Msg2 1230 transmissions, one or more Msg3 1240 transmissions, and contention resolution 1250. For example, the contention-free random access procedure may include one or more Msg 1 1220 transmissions and one or more Msg2 1230 transmissions.

[0272] In an example, the base station may transmit (e.g., unicast, multicast, or broadcast) a RACH configuration 1210 to the UE via one or more beams. The RACH configuration 1210 may include one or more parameters indicating at least one of: a set of available PRACH resources for transmission of a random access preamble, an initial preamble power (e.g., a random access preamble initial reception target power), an RSRP threshold for selecting an SS block and a corresponding PRACH resource, a power ramp factor (e.g., a random access preamble power ramp step size), a random access preamble index, a maximum number of preamble transmissions, preamble groups A and B, a threshold (e.g., a message size) for determining a random access preamble group, a set of one or more random access preambles and corresponding PRACH resources (if any) for a system information request, a set of one or more random access preambles and corresponding PRACH resources (if any) for a beam failure recovery request, a time window for monitoring a RA response, a time window for monitoring a response to a beam failure recovery request, and / or a contention resolution timer.

[0273] In an example, Msg1 1220 may be one or more transmissions of a random access preamble. For a contention-based random access procedure, the UE may select an SS block with an RSRP above an RSRP threshold. If there is a random access preamble group B, the UE may select one or more random access preambles from group A or group B based on the potential Msg3 1240 size. If there is no random access preamble group B, the UE may select one or more random access preambles from group A. The UE may randomly (e.g., with equal probability or normal distribution) select one or more random access preamble indexes from one or more random access preambles associated with the selected group. If the base station semi-statistically configures the UE with an association between the random access preamble and the SS block, the UE may randomly select a random access preamble index with equal probability from one or more random access preambles associated with the selected SS block and the selected group.

[0274] For example, the UE may initiate a contention-free random access procedure based on a beam failure indication from a lower layer. For example, the base station may semi-statistically configure the UE with one or more contention-free PRACH resources for a beam failure recovery request associated with at least one of the SS blocks and / or CSI-RS. If at least one of the SS blocks having an RSRP higher than a first RSRP threshold among the associated SS blocks or at least one of the CSI-RS having an RSRP higher than a second RSRP threshold among the associated CSI-RS is available, the UE may select a random access preamble index corresponding to the selected SS block or CSI-RS from a set of one or more random access preambles for the beam failure recovery request.

[0275] For example, the UE may receive a random access preamble index from the base station via PDCCH or RRC for a contention-free random access procedure. If the base station does not configure the UE with at least one contention-free PRACH resource associated with an SS block or CSI-RS, the UE may select a random access preamble index. If the base station configures the UE with one or more contention-free PRACH resources associated with the SS block, and at least one SS block with an RSRP higher than a first RSRP threshold is available among the related SS blocks, the UE may select the at least one SS block and select a random access preamble corresponding to the at least one SS block. If the base station configures the UE with one or more contention-free PRACH resources associated with the CSI-RS, and at least one CSI-RS with an RSRP higher than a second RSPR threshold is available among the associated CSI-RS, the UE may select the at least one CSI-RS and select a random access preamble corresponding to the at least one CSI-RS.

[0276] The UE may perform one or more Msg1 1220 transmissions by transmitting a selected random access preamble. For example, if the UE selects an SS block and is configured with an association between one or more PRACH opportunities and one or more SS blocks, the UE may determine the PRACH opportunity from one or more PRACH opportunities corresponding to the selected SS block. For example, if the UE selects a CSI-RS and is configured with an association between one or more PRACH opportunities and one or more CSI-RS, the UE may determine the PRACH opportunity from one or more PRACH opportunities corresponding to the selected CSI-RS. The UE may transmit the selected random access preamble to the base station via the selected PRACH opportunity. The UE may determine the transmit power for transmitting the selected random access preamble based at least on the initial preamble power and the power ramp factor. The UE may determine the RA-RNTI associated with the selected PRACH opportunity in which the selected random access preamble is transmitted. For example, the UE may not determine the RA-RNTI for the beam failure recovery request. The UE may determine the RA-RNTI based at least on an index of the first OFDM symbol and an index of a first slot of a selected PRACH opportunity and / or an uplink carrier index used for transmission of Msg1 1220 .

[0277] In an example, the UE may receive a random access response Msg 2 1230 from the base station. The UE may start a time window (e.g., ra-ResponseWindow) to monitor the random access response. For a beam failure recovery request, the base station may configure the UE with a different time window (e.g., bfr-ResponseWindow) to monitor the response to the beam failure recovery request. For example, the UE may start the time window (e.g., ra-ResponseWindow or bfr-ResponseWindow) at the beginning of the first PDCCH opportunity after a fixed duration of one or more symbols from the end of the preamble transmission. If the UE transmits multiple preambles, the UE may start the time window at the beginning of the first PDCCH opportunity after a fixed duration of one or more symbols from the end of the first preamble transmission. The UE may monitor the PDCCH of the cell for at least one random access response identified by the RA-RNTI or for at least one response to the beam failure recovery request identified by the C-RNTI while the timer of the time window is running.

[0278] In an example, if at least one random access response includes a random access preamble identifier corresponding to the random access preamble transmitted by the UE, the UE may consider that the reception of the random access response is successful. If the reception of the random access response is successful, the UE may consider that the contention-free random access procedure is successfully completed. If the contention-free random access procedure is triggered for a beam failure recovery request, the UE may consider that the contention-free random access procedure is successfully completed if the PDCCH transmission is addressed to the C-RNTI. In an example, if at least one random access response includes a random access preamble identifier, the UE may consider that the random access procedure is successfully completed and may indicate receipt of an acknowledgment of the system information request of the upper layer. If the UE has signaled multiple preamble transmissions, the UE may stop transmitting the remaining preambles (if any) in response to successfully receiving the corresponding random access responses.

[0279] In an example, the UE may perform one or more Msg 3 1240 transmissions (e.g., for a contention-based random access procedure) in response to successful reception of a random access response. The UE may adjust uplink transmission timing based on a timing advance command indicated by the random access response, and may transmit one or more transport blocks based on an uplink grant indicated by the random access response. The subcarrier spacing for PUSCH transmission of Msg3 1240 may be provided by at least one higher layer (e.g., RRC) parameter. The UE may transmit a random access preamble via PRACH and Msg3 1240 via PUSCH on the same cell. The base station may indicate the UL BWP for PUSCH transmission of Msg3 1240 via a system information block. The UE may retransmit Msg 3 1240 using HARQ.

[0280] In an example, multiple UEs may perform Msg 1 1220 by transmitting the same preamble to the base station and receiving the same random access response including an identity (e.g., TC-RNTI) from the base station. Contention resolution 1250 may ensure that the UE does not mistakenly use the identity of another UE. For example, contention resolution 1250 may be based on a C-RNTI on a PDCCH or a UE contention resolution identity on a DL-SCH. For example, if a base station assigns a C-RNTI to a UE, the UE may perform contention resolution 1250 based on the reception of a PDCCH transmission addressed to the C-RNTI. In response to detecting the C-RNTI on the PDCCH, the UE may deem contention resolution 1250 successful and may deem the random access procedure to have been successfully completed. If the UE does not have a valid C-RNTI, contention resolution may be resolved by adopting the TC-RNTI. For example, if the MAC PDU is successfully decoded and the MAC PDU includes a UE contention resolution identity MAC CE that matches the CCCH SDU transmitted in Msg3 1250, the UE may consider contention resolution 1250 to be successful and the random access procedure to be successfully completed.

[0281] Fig.11 It is an example structure of a MAC entity according to aspects of an embodiment. In an example, a wireless device can be configured to operate in a multiple connection mode. A wireless device in RRC_CONNECTED with multiple RX / TX can be configured to utilize radio resources provided by multiple schedulers located in multiple base stations. Multiple base stations can be connected via non-ideal or ideal backhaul on an Xn interface. In an example, a base station among multiple base stations can act as a primary base station or a secondary base station. The wireless device can be connected to a primary base station and one or more secondary base stations. The wireless device can be configured with multiple MAC entities, for example, one MAC entity for a primary base station, and one or more other MAC entities for a secondary base station. In an example, a configured service cell set for a wireless device can include two subsets: an MCG, which includes service cells of a primary base station; and one or more SCGs, which include service cells of secondary base stations. Fig.13 An example structure of a MAC entity when MCG and SCG are configured for a wireless device is shown.

[0282] In an instance, at least one cell in an SCG may have a configured UL CC, where the cell of at least one cell may be referred to as a PSCell or a PCell of the SCG, or sometimes simply referred to as a PCell. The PSCell may be configured with PUCCH resources. In an instance, when an SCG is configured, there may be at least one SCG bearer or one separate bearer. In an instance, after a physical layer problem or a random access problem is detected on the PSCell, or after the number of RLC retransmissions associated with the SCG is reached, or after an access problem is detected on the PSCell during an SCG addition or SCG change: the RRC connection reestablishment procedure may not be triggered, UL transmission to the cells of the SCG may be stopped, the UE may notify the primary base station of the SCG failure type, and DL data delivery on the primary base station may be maintained.

[0283] In an example, the MAC sublayer can provide services such as data transfer and radio resource allocation to an upper layer (e.g., 1310 or 1320). The MAC sublayer can include multiple MAC entities (e.g., 1350 and 1360). The MAC sublayer can provide data transfer services on logical channels. In order to accommodate different types of data transfer services, multiple types of logical channels can be defined. Logical channels can support the transfer of specific types of information. The logical channel type can be defined by what type of information (e.g., control or data) is transferred. For example, BCCH, PCCH, CCCH and DCCH can be control channels, and DTCH can be a traffic channel. In an example, a first MAC entity (e.g., 1310) can provide services on PCCH, BCCH, CCCH, DCCH, DTCH and MAC control elements. In an example, a second MAC entity (e.g., 1320) can provide services on BCCH, DCCH, DTCH and MAC control elements.

[0284] The MAC sublayer may expect services from the physical layer (e.g., 1330 or 1340), such as data transfer services, signaling of HARQ feedback, scheduling requests, or signaling of measurement values ​​(e.g., CQI). In an instance, in a dual connection, two MAC entities may be configured for the wireless device: one for the MCG and one for the SCG. The MAC entity of the wireless device may process multiple transport channels. In an instance, a first MAC entity may process a first transport channel, including a PCCH of the MCG, a first BCH of the MCG, one or more first DL-SCHs of the MCG, one or more first UL-SCHs of the MCG, and one or more first RACHs of the MCG. In an instance, a second MAC entity may process a second transport channel, including a second BCH of the SCG, one or more second DL-SCHs of the SCG, one or more second UL-SCHs of the SCG, and one or more second RACHs of the SCG.

[0285] In an example, if a MAC entity is configured with one or more SCells, there can be multiple DL-SCHs per MAC entity, and there can be multiple UL-SCHs as well as multiple RACHs. In an example, there can be one DL-SCH and UL-SCH on a SpCell. In an example, for a SCell, there can be one DL-SCH, zero or one UL-SCH, and zero or one RACH. The DL-SCH can support reception using different numbers and / or TTI durations within the MAC entity. The UL-SCH can also support transmission using different numbers and / or TTI durations within the MAC entity.

[0286] In an example, the MAC sublayer may support different functions and these functions may be controlled using control (e.g., 1355 or 1365) elements. Functions performed by the MAC entity may include mapping between logical channels and transport channels (e.g., in uplink or downlink), multiplexing (e.g., 1352 or 1362) MAC SDUs from one or different logical channels to a transport block (TB) to be delivered to a physical layer on a transport channel (e.g., in uplink), demultiplexing (e.g., 1352 or 1362) MAC SDUs from a transport block (TB) delivered from a physical layer on a transport channel to one or different logical channels (e.g., in downlink), scheduling information reporting (e.g., in uplink), error correction by HARQ in uplink or downlink (e.g., 1363), and logical channel prioritization in uplink (e.g., 1351 or 1361). The MAC entity may handle a random access procedure (e.g., 1354 or 1364).

[0287] Fig.12 is an example diagram of a RAN architecture including one or more base stations. In an example, a protocol stack (e.g., RRC, SDAP, PDCP, RLC, MAC, and PHY) can be supported at a node. A base station (e.g., 120A or 120B) may include a base station central unit (CU) (e.g., gNB-CU 1420A or 1420B) and at least one base station distributed unit (DU) (e.g., gNB-DU1430A, 1430B, 1430C, or 1430D) (if functional division is configured). The upper protocol layers of the base station may be located in the base station CU, and the lower layers of the base station may be located in the base station DU. The F1 interface (e.g., CU-DU interface) connecting the base station CU and the base station DU may be an ideal or non-ideal backhaul. F1-C may provide a control plane connection via the F1 interface, and F1-U may provide a user plane connection via the F1 interface. In an example, an Xn interface may be configured between base station CUs.

[0288] In an example, the base station CU may include an RRC function, an SDAP layer, and a PDCP layer, and the base station DU may include an RLC layer, a MAC layer, and a PHY layer. In an example, various functional division options between the base station CU and the base station DU are possible by locating different combinations of upper protocol layers (RAN functions) in the base station CU and different combinations of lower protocol layers (RAN functions) in the base station DU. The functional division may support the flexibility of moving protocol layers between the base station CU and the base station DU according to service requirements and / or network environment.

[0289] In an instance, the functional partitioning options can be configured for each base station, each base station CU, each base station DU, each UE, each bearer, each slice, or at other granularity. In each base station CU partition, the base station CU can have a fixed partitioning option, and the base station DU can be configured to match the partitioning option of the base station CU. In each base station DU partition, the base station DU can be configured with different partitioning options, and the base station CU can provide different partitioning options for different base station DUs. In each UE partition, the base station (base station CU and at least one base station DU) can provide different partitioning options for different wireless devices. In each bearer partition, different partitioning options can be used for different bearers. In each slice splicing, different partitioning options can be applied to different slices.

[0290] Fig.13is an example diagram showing RRC state transitions of a wireless device. In an example, the wireless device may be in at least one of an RRC connected state (e.g., RRC connected 1530, RRC_Connected), an RRC idle state (e.g., RRC idle 1510, RRC_Idle), and / or an RRC inactive state (e.g., RRC inactive 1520, RRC_Inactive). In an example, in the RRC connected state, the wireless device may have at least one RRC connection with at least one base station (e.g., gNB and / or eNB), which may have a UE context of the wireless device. The UE context (e.g., wireless device context) may include at least one of an access layer context, one or more radio link configuration parameters, a bearer (e.g., a data radio bearer (DRB), a signaling radio bearer (SRB), a logical channel, a QoS flow, a PDU session, etc.), configuration information, security information, PHY / MAC / RLC / PDCP / SDAP layer configuration information, and / or similar configuration information for the wireless device. In an example, in the RRC idle state, the wireless device may not have an RRC connection with the base station, and the UE context of the wireless device may not be stored in the base station. In an example, in the RRC inactive state, the wireless device may not have an RRC connection with the base station. The UE context of the wireless device may be stored in the base station, which may be referred to as an anchor base station (e.g., a last serving base station).

[0291] In an example, the wireless device may transition the UE RRC state between the RRC idle state and the RRC connected state in two ways (e.g., connection release 1540 or connection establishment 1550; or connection reestablishment) and / or between the RRC inactive state and the RRC connected state in two ways (e.g., connection deactivation 1570 or connection recovery 1580). In an example, the wireless device may transition its RRC state from the RRC inactive state to the RRC idle state (e.g., connection release 1560).

[0292] In an example, an anchor base station may be a base station that maintains a UE context (wireless device context) of a wireless device at least during a period of time when the wireless device stays in a RAN notification area (RNA) of the anchor base station and / or when the wireless device stays in an RRC inactive state. In an example, an anchor base station may be a base station to which a wireless device in an RRC inactive state was last connected in the latest RRC connected state, or a base station where the wireless device last performed an RNA update procedure. In an example, an RNA may include one or more cells operated by one or more base stations. In an example, a base station may belong to one or more RNAs. In an example, a cell may belong to one or more RNAs.

[0293] In an example, the wireless device may transition the UE RRC state from the RRC connected state to the RRC inactive state in the base station. The wireless device may receive RNA information from the base station. The RNA information may include at least one of an RNA identifier, one or more cell identifiers of one or more cells of the RNA, a base station identifier, an IP address of the base station, an AS context identifier of the wireless device, a recovery identifier, etc.

[0294] In an instance, an anchor base station may broadcast a message (e.g., a RAN paging message) to a base station of the RNA to reach a wireless device in an RRC inactive state, and / or a base station receiving a message from the anchor base station may broadcast and / or multicast another message (e.g., a paging message) over an air interface to wireless devices in its coverage area, a cell coverage area, and / or a beam coverage area associated with the RNA.

[0295] In an example, when a wireless device in an RRC inactive state moves to a new RNA, the wireless device may perform an RNA update (RNAU) procedure, which may include a random access procedure and / or a UE context retrieval procedure for the wireless device. The UE context retrieval may include: a base station receiving a random access preamble from the wireless device; and the base station extracting a UE context of the wireless device from an old anchor base station. The extraction may include: sending a retrieve UE context request message including a recovery identifier to the old anchor base station, and receiving a retrieve UE context response message including the UE context of the wireless device from the old anchor base station.

[0296] In an example embodiment, a wireless device in an RRC inactive state may select a cell to camp on based on measurement results of at least one or more cells, cells that the wireless device may monitor RNA paging messages, and / or core network paging messages from a base station. In an example, a wireless device in an RRC inactive state may select a cell to perform a random access procedure to restore an RRC connection and / or transmit one or more packets to a base station (e.g., to a network). In an example, if the selected cell belongs to an RNA different from the RNA of the wireless device in an RRC inactive state, the wireless device may initiate a random access procedure to perform an RNA update procedure. In an example, if the wireless device in an RRC inactive state has one or more packets in a buffer to transmit to the network, the wireless device may initiate a random access procedure to transmit one or more packets to a base station of a cell selected by the wireless device. The random access procedure may be performed using two messages (e.g., level 2 random access) and / or four messages (e.g., level 4 random access) between the wireless device and the base station.

[0297] In an example embodiment, a base station receiving one or more uplink packets from a wireless device in an RRC inactive state may extract a UE context for the wireless device based on at least one of an AS context identifier, an RNA identifier, a base station identifier, a recovery identifier, and / or a cell identifier received from the wireless device by transmitting a retrieve UE context request message for the wireless device to an anchor base station of the wireless device. In response to extracting the UE context, the base station may transmit a path switch request for the wireless device to a core network entity (e.g., AMF, MME, etc.). The core network entity may update a downlink tunnel endpoint identifier of one or more bearers established between a user plane core network entity (e.g., UPF, S-GW, etc.) and a RAN node (e.g., a base station) for the wireless device, for example, changing the downlink tunnel endpoint identifier from an address of the anchor base station to an address of the base station.

[0298] The gNB may communicate with the wireless device via a wireless network that employs one or more new radio technologies. The one or more radio technologies may include at least one of: multiple technologies associated with a physical layer; multiple technologies associated with a media access control layer; and / or multiple technologies associated with a radio resource control layer. Example embodiments that enhance the one or more radio technologies may improve the performance of the wireless network. Example embodiments may increase system throughput or data transmission rate. Example embodiments may reduce battery consumption of the wireless device. Example embodiments may improve latency of data transmission between the gNB and the wireless device. Example embodiments may improve network coverage of the wireless network. Example embodiments may increase transmission efficiency of the wireless network.

[0299] In an example embodiment, a wireless device of a 5G network may remain in at least one RRC state among an RRC connected state, an RRC idle state, and an RRC inactive state. In one example, in the RRC connected state, the wireless device may have at least one RRC connection with at least one base station, and the base station may have a UE context of the wireless device. The UE context (wireless device context) may include at least one of an AS context, bearer configuration information, security information, PDCP configuration information, and / or other configuration information of the wireless device. In an example, in the RRC idle state, the wireless device may not have an RRC connection with a base station, and the UE context of the wireless device may not be stored in the base station. In one example, in the RRC inactive state, the wireless device may not have an RRC connection with a base station, but the UE context of the wireless device may be stored in a base station, which may be referred to as an anchor base station.

[0300] In an example embodiment, the wireless device may transition its RRC state in two ways between an RRC idle state and an RRC connected state, and in two ways between an RRC inactive state and an RRC connected state, and in one direction from an RRC inactive state to an RRC idle state.

[0301] In an example embodiment, an anchor base station may be a base station that can maintain a UE context (wireless device context) at least as long as the UE context's associated wireless device remains in the RNA (RAN Notification Area) of the anchor base station. In an example, the anchor base station in the UE-specific anchor case may be the base station to which the wireless device in the RRC inactive state was last connected in the most recent RRC connected state, or the base station where the wireless device last performed an RNA update procedure. In an example, the anchor base station in the common anchor case may be a base station determined to maintain the UE context of the wireless device in the RRC inactive state that stays in the RNA of the anchor base station. In the common anchor case, one or more anchor base stations may be present in the RNA.

[0302] In an example embodiment, an RNA may include one or more cells operated by one or more base stations. In an example, a base station may belong to one or more RNAs. In an example, a cell may belong to one or more RNAs. In an example, an anchor base station may broadcast a message to a base station in an RNA to reach a wireless device in an RRC inactive state, and a base station receiving a broadcast message from an anchor base station may broadcast and / or multicast another message to wireless devices in its coverage area, cell coverage area, and / or beam coverage area associated with an RNA via an air interface. In an example, when a wireless device in an RRC inactive state moves to a new RNA, it may perform an RNA update (RNAU) procedure, which may include a random access procedure and / or a UE context retrieval procedure performed by the wireless device, the UE context retrieval procedure being to extract the UE context of the wireless device from the old anchor base station of the old RNA to the new anchor base station of the new RNA by receiving a random access preamble from the wireless device through the base station.

[0303] In an example embodiment, the wireless device may transition its RRC state from an RRC connected state to an RRC inactive state in the first base station. In an example, the wireless device may receive RNA information from the first base station. If the first base station is an anchor base station for the wireless device (i.e., in a UE-specific anchor case, or if the first base station is an anchor base station in a common anchor case), the RNA information may include at least one of an RNA identifier, a cell identifier, a base station identifier, an IP address of the first base station, and / or an AS context identifier of the wireless device. If the first base station is not an anchor base station for the wireless device (i.e., if the first base station is not an anchor base station in a common anchor case), the RNA information may include at least one of an RNA identifier, a cell identifier of the first base station, a base station identifier of the anchor base station, an IP address of the anchor base station, and / or an AS context identifier.

[0304] In one example, if the first base station is an anchor base station for the wireless device, the first base station may maintain the UE context of the wireless device at least during the period that the wireless device stays in the RNA associated with the wireless device. If the first base station is not an anchor base station for the wireless device, the first base station may transmit one or more elements of the UE context of the wireless device to the anchor base station, and the anchor base station may maintain the one or more elements of the UE context of the wireless device at least during the period that the wireless device stays in the RNA associated with the wireless device.

[0305] In an example embodiment, a wireless device in an RRC inactive state may select a cell in which the wireless device receives an RNA paging message and / or a core network paging message from a base station. In one example, a wireless device in an RRC inactive state may select a cell to perform a random access procedure to establish an RRC connection and / or transmit one or more packets. In one example, if the selected cell belongs to an RNA different from the RNA associated with the wireless device, the wireless device may initiate a random access procedure to perform an RNA update procedure. In one example, if the wireless device in an RRC inactive state has one or more packets in its buffer to transmit to the network, the wireless device may initiate a random access procedure to transmit the one or more packets to the base station of the cell selected by the wireless device. The random access procedure may be performed with two messages and / or four messages between the wireless device and the base station. In one example, one or more uplink packets of the wireless device in an RRC inactive state may be PDCP protocol layer packets.

[0306] In an example embodiment, one or more uplink packets from a wireless device in an RRC inactive state may be transmitted to a core network entity. In an example, a first base station that receives one or more uplink packets from a wireless device in an RRC inactive state may transmit the one or more uplink packets to an anchor base station of the wireless device based on at least one of an AS context identifier, an RNA identifier, a base station identifier, and / or a cell identifier received from the wireless device. In an example, the anchor base station may transmit the uplink data packet to the core network entity based at least on a UE context, the UE context being retrieved based at least on the AS context identifier and / or the wireless device identifier received from the first base station.

[0307] In an example embodiment, a first base station receiving one or more uplink packets from a wireless device in an RRC inactive state may transmit a UE context extraction request for the wireless device to an anchor base station of the wireless device based on at least one of an AS context identifier, an RNA identifier, a base station identifier, and / or a cell identifier received from the wireless device. In one example, the anchor base station may transmit the UE context of the wireless device to the first base station based on at least one of the AS context identifier and / or the wireless device identifier received from the first base station. The first base station receiving the UE context may transmit a path switch request for the wireless device to a core network entity, and the core network entity may update a downlink tunnel endpoint identifier of one or more bearers established for the wireless device between the user plane core network entity and the RAN node, for example, changing the downlink tunnel endpoint identifier from the address of the anchor base station to the address of the first base station. In one example, the first base station may transmit the one or more uplink packets to the user plane core network entity based on the UE context and / or at least one of the one or more bearers updated between the user plane core network entity and the first base station. In one example, the anchor base station may remove the UE context of the wireless device.

[0308] In addition to the CN tracking area, UEs in RRC_INACTIVE can also be tracked on a "RAN-based notification area" (herein referred to as "RAN area"), where the UE can move freely without notifying the network. Once the UE moves outside the RAN area, it can perform a RAN area update.

[0309] Since the RAN area is only applicable to UEs in RRC_INACTIVE, a RAN area update may be performed using an RRCConnectionResume Request message (e.g., which may be used to transition from RRC_INACTIVE to RRC_CONNECTED) with a causeValue equal to, for example, "ranNotificationAreaUpdateRequest". A motivation for using this message may be that there may be DL data waiting, so the network may have the possibility to command the UE to enter the RRC_CONNECTED state (and complete the "resume" procedure).

[0310] When the network receives the RRCConnectionResumeRequest message, if it finds the UE context, it can relocate the UE context and CN / RAN connection, and then use the RRCConnection Suspend message to directly suspend the UE with the updated RAN notification area. If there is DL data for the UE at this time, the network can respond to the RRCConnectionResume message that causes the UE to transition to RRC_CONNECTED. If there is no UL or DL ​​data, the UE can return to RRC_INACTIVE as soon as possible. The UE may need to be given a new resumption identity when it is suspended to RRC_INACTIVE to indicate the new location of the UE context. The UE-specific RAN area can be updated with the ranAreaInformation included in the RRCConnectionSuspend message. ranAreaInformation can indicate the entire new RAN area using a list of cells, or use delta signaling to inform which cells can be added / removed from the RAN area. In addition, ranAreaInformation can also indicate whether the UE can use its old RAN area, or whether the RAN area can be composed of the UE's TAI list.

[0311] Because the UE may be assigned a new RAN area and a new resume ID (resumption identity) when the connection is suspended, it may be important that the RRCConnectionSuspend message may be encrypted and integrity protected. In LTE, this may be achieved by providing the UE with the next hop chaining counter (NCC) in the RRCConnectionSetup message and transitioning to RRC_CONNECTED if security may be enabled. In order to optimize the RAN area update procedure and allow the UE to suspend directly to RRC_INACTIVE as a response to the RRCConnectionResumeRequest, it may be necessary that the UE may have derived encryption keys at MSG3. This may be achieved by providing the UE with the NCC already in the RRCConnectionSuspend message. This may also allow integrity protection of the RRCConnectionResumeRequest.

[0312] Furthermore, there may be situations where the RAN is unable to retrieve the old UE context, e.g. it is lost or discarded or resides in a gNB from which it cannot extract the context. In this case, it may not be possible to complete the RAN area update without first reestablishing the RAN context.

[0313] In this case, when the UE transmits an RRCConnectionResumeRequest message, the RAN may respond with an RRCConnectionSetup, which may trigger the UE to initiate NAS level procedures, causing the CN to reestablish the UE context in the RAN. Because the RAN may sense that the UE wants to perform a RAN Notification Area Update and there may not be UL or DL ​​data available, Figure 3 As can be seen in FIG. 1 , once the AS context has been reestablished, it can quickly cause the UE to re-suspend to RRC_INACTIVE.

[0314] If the RAN decides that the UE may not re-suspend to RRC_INACTIVE after the RAN notifies the area update, it may respond with an RRCConnectionReject, which may cause the UE to transition to RRC_IDLE. Additional signaling may be required on the network side to trigger the removal of the RAN context.

[0315] In LTE, a UE in RRC_IDLE may perform a periodic TAU (Tracking Area Update) upon expiration of the TA Update Timer (T3412) so that the CN confirms the UE location on the tracking area level and checks whether the UE is still attached to the network. For example, if the UE is switched off, the absence of a periodic TAU may indicate to the CN that the UE may no longer be in an attached state and the network context may be removed. In RRC_CONNECTED, it may not be necessary to perform a periodic TAU, as the network may know the UE location on the cell level, and it may be the responsibility of the RAN layer to ensure that the UE is still connected. For RRC_INACTIVE, the motivation for performing a periodic area update may remain the same as for a periodic TAU in RRC_IDLE, i.e., the network may need to be able to confirm that the UE cannot disappear from the network (e.g., powered off) without informing the network. A UE in an RRC inactive state may perform a periodic TAU, a RAN area update, or both.

[0316] Since the periodic area update is mainly intended to inform the network that the UE may remain in the same area as before, this signaling may be performed as lightly as possible. If a periodic TAU is performed from RRC_INACTIVE, the UE may enter RRC_CONNECTED to transmit the NAS message "TAU Request" and may wait for the NAS message "TAU Accept" from the CN, after which it may return to RRC_INACTIVE. On the other hand, a successful periodic RAN area update may consist of an RRCConnectionResumeRequest message with, for example, causeValue "ranNotificationAreaUpdateRequest". If the periodic RAN area update is performed in the same gNB as the UE may have been suspended, the UE context may already be available in the gNB and the UE may suspend directly to RRC_INACTIVE. The RRCConnectionSuspend message from the gNB may contain the new resumeId (resumption identity), "ranAreaInformation" (e.g. a list of cells, or an indication to use the old RAN area, or an indication to use the TA list as the RAN area), and the next hop chaining counter (NCC). The new resumption ID (resumption identity) may indicate the updated UE context, the RAN area information may ensure that the UE may maintain the latest RAN area, and the NCC may ensure that the UE may resume the connection even in a different gNB if encryption has been enabled in message three of the random access procedure.

[0317] If the UE resumes connectivity in another gNB inside the RAN area, the UE context may be extracted from the old gNB based on mobility using a procedure similar to that used for RAN Area Update. Additionally, the RAN may decide to release the UE to RRC_IDLE during a periodic RAN Area Update, for example if it may have performed multiple periodic RAN Area Updates in the same area without any UP activity. If the UE resumes connectivity in the old gNB, the RAN may respond to the RRCConnectionResumeRequest with an RRCConnectionRelease as seen in Figure 5. When the RAN releases the UE context, the CN may need to be informed so that it can release the CN context and / or the UE context stored in another gNB.

[0318] The periodic TA update timer (T3412) may be set by the CN and may have a default value of 54 minutes in LTE. However, in some cases, the RAN may want to have a periodic location update with a different period than the periodic TAU. Therefore, the RAN may be able to configure a separate timer for the RAN area update. If the periodic RAN area update fails, for example if the UE context cannot be retrieved, the RAN may decide to respond with an RRCConnectionSetup or RRCConnectionSetup to cause the UE to transition to RRC_CONNECTED so that the CN is also updated, such as Figure 6 It may be important to update the CN in the case where the CN believes that the UE may be in RRC_IDLE and may have started a periodic TAU timer.

[0319] Since the RAN area update may be lighter weight compared to a TAU, the UE may perform periodic RAN area updates only in RRC_INACTIVE.

[0320] Example of inactive data forwarding

[0321] In the existing RAN paging procedure, the base station exchanges backhaul signaling to transmit downlink packets to the wireless device in the RRC inactive state. The anchor base station may transmit the paging message via its cell and / or transmit the paging message to its neighboring base station of the RAN notification area associated with the wireless device. The implementation of the existing backhaul signaling when the RAN paging procedure fails may be due to the inefficiency of packet forwarding to the wireless device, resulting in an increased packet loss rate and / or an increased call drop rate. The failure of the RAN paging procedure may require further enhancement of the communication between network nodes (e.g., base stations, core network entities, wireless devices). In one example, the failure rate of receiving downlink user plane or control plane packets (e.g., data packets, NAS / RRC signaling packets) may increase for RRC inactive state wireless devices. The increased packet loss rate may degrade the network system reliability. It is necessary to improve the backhaul signaling mechanism for RRC inactive state wireless devices. The example embodiment enhances the information exchange between network nodes to improve the network communication reliability when the wireless device is in the RRC inactive state or the RRC idle state. The example may enhance the signaling procedure when the RAN paging procedure fails. In existing network signaling, when the RAN paging procedure initiated for packet transmission fails, the anchor base station may discard packets received from the core network entity.

[0322] In such Fig.14 and Fig.15 In the example embodiment shown in , when receiving a packet for a wireless device (e.g., UE) in an RRC inactive state from a user plane core network entity (e.g., UPF), a first base station (e.g., gNB) may initiate a RAN paging procedure by transmitting one or more first paging messages to one or more second base stations. If the first base station fails in the RAN paging procedure, the first base station may transmit a paging failure indication to a control plane core network entity (e.g., AMF). The core network entity may initiate core network paging (e.g., a paging procedure based on a tracking area) for the wireless device. A third base station may receive a response to the core network paging procedure from the wireless device, and the third base station may send a tunnel endpoint identifier (e.g., an IP address) of the third base station to the first base station, for example, via the core network entity. The first base station may transmit a packet received from the user plane core network entity to the third base station based on the tunnel endpoint identifier.

[0323] Example embodiments may enhance system reliability by enabling network nodes to share tunnel information for packet forwarding to wireless devices when RAN paging procedures fail. Example embodiments may enable network nodes to reduce packet loss or call drop rates for RRC inactive and / or idle state wireless devices in the event of RAN paging failure.

[0324] In one example, a first base station may receive one or more packets for a wireless device in a radio resource control (RRC) inactive state from a first core network entity. The first base station may be an anchor base station for the wireless device, and / or a base station that initiates a state transition of the wireless device to the RRC inactive state. The first base station may maintain a UE context for the wireless device. The UE context may include at least one of a PDU session configuration, a security configuration, a radio bearer configuration, a logical channel configuration, a recovery identifier associated with the RRC inactive state, and RAN notification area information (e.g., a RAN area identifier, a cell identifier, and a base station identifier of a RAN notification area of ​​the wireless device). When the first base station adopts a base station-core network colocation structure (e.g., selected IP service offload, SIPTO), the first core network entity may include a user plane core network entity (e.g., UPF), a control plane core network entity (e.g., AMF), and / or an application server. The one or more packets may include a downlink data packet for the wireless device in the RRC inactive state. In one example, the downlink data packet may be associated with a specific service, such as a vehicle communication downlink packet transmission, an ultra-reliable low latency (URLLC) service, a machine type communication (MTC) service, and the like. The one or more packets may include control signaling packets, such as one or more NAS layer messages transmitted by the AMF.

[0325] In one example, the first base station may initiate a RAN paging procedure, which includes sending at least one RAN paging message to at least one second base station. The at least one RAN paging message may include a first identifier of the wireless device. The RAN paging procedure may be initiated to page the wireless device in an RRC inactive state to forward the one or more packets received from the first core network entity. The at least one paging message may include at least one of the following: a UE identifier of the wireless device, a UE paging identifier associated with a RAN paging procedure for the wireless device, paging DRX information for transmitting a radio paging indication to the wireless device (e.g., the at least one second base station may transmit a paging message via a radio interface based on the paging DRX information, thereby indicating when the wireless device monitors radio signaling), RAN paging area information of a RAN paging area (e.g., a RAN notification area associated with the RAN paging procedure, a RAN area identifier, a cell identifier), a RAN paging priority, and the like.

[0326] In one example, the at least one second base station may serve at least one cell associated with a RAN paging area (e.g., a RAN notification area, a RAN area, a cell). In one example, when the at least one second base station receives the at least one RAN paging message, the at least one second base station may transmit / broadcast / multicast one or more paging indications via one or more cells associated with the RAN paging area (e.g., a RAN notification area, a RAN area, a cell) of the wireless device. The one or more paging indications may be transmitted via one or more beams of the one or more cells. In one example, the first base station may transmit the at least one RAN paging message (e.g., an RRC paging indication) via one or more of its serving cells associated with the RAN paging area of ​​the wireless device.

[0327] In one example, the first base station may determine a failure of the RAN paging procedure in response to not receiving a response to the at least one RAN paging message. In one example, the first base station may determine the failure based on no response to the at least one RAN paging message within a specific time period. When the first base station receives a message indicating a UE context retrieval request for the wireless device from at least one of the at least one second base station in response to the at least one RAN paging message, the first base station may consider the RAN paging procedure to be successful (e.g., not failed). When the first base station receives a random access preamble and / or an RRC connection recovery request message from the wireless device in response to the at least one RAN paging message, the first base station may consider the RAN paging procedure to be successful (e.g., not failed).

[0328] In one example, the first base station may send a first message to a second core network entity in response to a failure of a RAN paging procedure. In one example, the second core network entity may be a control plane core network entity (e.g., AMF). For example, the first message may include a UE context release request message and / or a RAN paging failure indication message. In one example, the first message may indicate a RAN paging failure for the wireless device. In one example, the first message may be a UE context release request message including a cause information element indicating that a cause of the UE context release request includes a failure of a RAN paging procedure for the wireless device.

[0329] In one example, the second core network entity may transmit one or more core network paging messages (e.g., tracking area paging messages) to one or more base stations of a tracking area of ​​the wireless device in response to the first message. The one or more base stations may include a third base station. The third message may transmit paging messages via one or more serving cells of the tracking area, and may receive a response to at least one of the paging messages from the wireless device. The response may include a random access preamble and / or an RRC connection request / resumption message.

[0330] In one example, the one or more core network paging messages and / or paging messages may include an indication parameter indicating that the wireless device is in an RRC inactive state or that a RAN paging procedure for the wireless device has failed. In one example, the one or more core network paging messages and / or paging messages may include an indication parameter indicating that the anchor base station (e.g., the first base station) has a UE context for the wireless device. In one example, the indication parameter may include a recovery identifier (ID) of the wireless device in the RRC inactive state. In response to receiving a response from the wireless device, the third base station may transmit a tunnel endpoint identifier (e.g., a tunnel identifier) ​​of the tunnel for data forwarding to the second core network entity. The data forwarding may include transmitting the one or more packets from the first base station to the third base station. The tunnel endpoint identifier may include an IP address of the third base station. The tunnel may include a logical IP tunnel between the first base station and the third base station. The transmission of the tunnel endpoint identifier may be based on an indication parameter (of the one or more core network paging messages) indicating that the anchor base station (e.g., the first base station) has a UE context for the wireless device.

[0331] In one example, the first base station may receive a second message including a tunnel endpoint identifier of a third base station from the second core network entity and in response to the first message for forwarding the one or more packets. In one example, the second message may include a UE context release request complete message (e.g., a response message to the UE context release request message) and / or a path switch message.

[0332] In one example, the first base station may send the one or more packets to the third base station based on the tunnel endpoint identifier. The third base station may forward the one or more packets to the wireless device via a radio interface. In one example, the one or more packets may be sent from the first base station to the third base station using a GTP-U protocol. In one example, the first base station may send a packet sequence number (e.g., a PDCP packet sequence number) for packet reordering at the third base station and / or at the wireless device.

[0333] In an example embodiment, the first base station may forward the one or more packets to a new serving base station (e.g., a third base station) of the wireless device when a RAN paging procedure for transmitting the one or more packets fails. Example embodiments may enhance the transmission reliability of packets (e.g., data packets and / or control plane packets, NAS messages) for RRC inactive state wireless devices and / or RRC idle state wireless devices by enabling forwarding of downlink packets received by an anchor base station to a new serving base station.

[0334] In an example embodiment, a process for transmitting a downlink packet to a wireless device in an RRC inactive state when a RAN paging procedure fails needs to be implemented. The example embodiment describes how a base station initiates a core network paging procedure and forwards the downlink packet to a new base station when the base station fails to complete the RAN paging procedure for the downlink packet, and the new base station receives a response to a paging message of the core network paging procedure from the wireless device.

[0335] In one example, there may be two potential options for transmitting one or more downlink packets to a wireless device in an RRC inactive state: paging together with the wireless device in the RNA (option 1), and / or transmitting after the wireless device is located (option 2). Option 1 benefits from lower latency at the expense of more radio resources because the data is transmitted in all cells in the RNA. From a power consumption perspective, other wireless devices in an RRC inactive state in the same paging occasion may have to decode more data to check whether they are the target UE. As for option 2: the anchor gNB (base station) with a connection to the CN should initiate paging in the entire RAN-based area. The one or more downlink packets may be transmitted only after the UE responds to save air resources.

[0336] In conventional LTE, the UE may send a paging response for identification via a random access procedure carrying an RRC message (RRC request / RRC resume) and initiate protocol setup / resumption, as shown in FIG. 7 .

[0337] In a traditional system, a 4-step RA may be required to identify the UE identity, and RRC messages may also be involved. For small data transmission cases, traditional procedures may be inefficient in terms of signaling overhead and waiting time. In this case, RRC messages may be used for 3 main reasons: 1). UE resolution. 2). Configuration of related parameters / protocols 3) State transition to connected for better scheduling of data. Because the UE in the inactive state has stored the AS context and the DL data packet size is limited, although UE resolution can be handled by other solutions, direct small data transmission without the involvement of RRC messages may be possible for the inactive state. For example, if Figure 8 As shown in , this procedure can significantly reduce signaling overhead and latency.

[0338] In one example, paging may carry a message indicating a direct small data transmission in an inactive state (except for state transitions, which may have an impact on UE behavior). A UE receiving a paging may send a UEID on a pre-configured contention-based resource (e.g., no grant / preamble+UE ID, where the UE ID used here may be valid at least in the RAN notification area). The gNB receiving may confirm the UE location after receiving the UE ID, and may then extract the UE context as needed and schedule DL data transmission on a pre-configured receive window along with a UL grant for the ACK. Latency may be further reduced by forwarding the UE context along with the paging message on the Xn interface. An acknowledgment may be sent with the received UL grant.

[0339] If the UE location is known at the cell level, direct DL transmission without paging may be considered. Because the UE may be monitoring paging, one possibility may be to directly schedule data transmission using a unique UE ID during the UE paging occasion. The UE ID may be an S-TMSI / long UE ID valid in the RAN notification area or C-RNTI in the inactive state. If DL data is scheduled based on a common RNTI and a long UE ID is indicated in the MAC CE, other inactive UEs receiving the data may need to further check the long UE ID, which may require more potential power consumption. If there is a valid C_RNTI, the C-RNTI may be preferred, which may be similar to UMTS CELL_FACH.

[0340] After data reception, the UE may need to send feedback to the RAN side. The data transmission may include an indication of whether the UE continues to monitor the PDCCH for subsequent data reception. If the UE does not monitor the PDCCH subsequently, the network may wait until the next paging occasion to send the data.

[0341] Using UL based mobility, the network may have enough information so that instead of paging the UE in one or more cells, it may be possible to even enable dedicated transmissions to the UE using beamforming, which may greatly enhance transmission efficiency.

[0342] For UEs with DL-based mobility (i.e., cell reselection), the time interval since the last interaction between the UE and the network may be considered. If the interactions are frequent, such as when a DL ACK arrives shortly after a UL transmission, the network may consider that the UE is still camped on the same cell. DL data may be forwarded directly to this cell for transmission. If an ACK is not received, the network may forward the information to its neighbors or start paging.

[0343] In one example, when the wireless device is in an RRC inactive state, the core network entity may transmit a downlink packet for the wireless device to an anchor base station having a wireless device context of the wireless device, and the anchor base station may initiate an RNA paging procedure to forward the downlink packet. In one example, the downlink packet may require an RRC connected state of the wireless device, and / or may be transmitted to a wireless device that remains in an RRC inactive state. The RNA paging procedure may include transmitting a first RNA paging message by the anchor base station to multiple base stations belonging to an RNA associated with the wireless device, and / or broadcasting a second RNA paging message via a radio interface by a base station that receives the first RNA paging message. In one example, if the wireless device receives the second RNA paging message, it may transmit a first RNA paging response to the base station that transmits the second RNA paging message. After receiving the first RNA paging response, the base station may transmit a second RNA paging response to the anchor base station.

[0344] In one example, the first RNA paging message may include at least one of an RNA identifier, an AS context identifier, a wireless device identifier, and / or a reason for RNA paging. The base station receiving the first RNA message may broadcast / multicast a second RNA paging message in one or more beam coverage areas and / or in one or more cell coverage areas based at least on the RNA identifier. In one example, the second RNA paging message may include at least one of an AS context identifier, a wireless device identifier, and / or a reason for RNA paging. The wireless device as the target of RNA paging may recognize the second RNA paging message based on at least one of the AS context identifier and / or the wireless device identifier, and may perform a random access procedure to transmit a first RNA paging response based at least on the reason for RNA paging, wherein the random access procedure may be one of a level 2 random access and / or a level 4 random access. In one example, the first RNA paging response may include an RRC connection request. In one example, the second RNA paging response may include a wireless device context extraction request.

[0345] In one example, if the anchor base station does not receive a second RNA paging response after initiating an RNA paging procedure for a downlink packet, the anchor base station may transmit a core network paging request message to a core network entity. The core network paging request message may be configured by the core network entity to initiate a core network paging procedure. The core network paging procedure may include transmitting a first core network paging message to multiple base stations belonging to a tracking area associated with the wireless device through a core network entity, and / or broadcasting / multicasting a second core network paging message via a radio interface by a base station receiving the first core network paging message. In one example, if the wireless device receives a second core network paging message, it may transmit a first core network paging response to the base station that transmitted the first core network paging message. In one example, the first core network paging response may be one of the messages of a level 2 random access and / or level 4 random access procedure. In one example, the first core network paging response may include an RRC connection request.

[0346] In one example, the first core network paging message may include a base station identifier of the anchor base station. The first base station receiving the first core network paging response may determine whether a direct interface (eg, an Xn interface) exists between the anchor base station and the first base station based at least on the base station identifier of the anchor base station.

[0347] In one example, the first base station may transmit a tunnel endpoint identifier of the first base station to a core network entity in response to receiving the first core network paging response, and the core network entity may forward the tunnel endpoint identifier of the first base station to the anchor base station. In one example, the anchor base station may forward one or more downlink packets for the wireless device to the first base station based at least on the tunnel endpoint identifier of the first base station. In one example, the first base station may forward the one or more downlink packets to the wireless device via radio signaling. In one example, the radio signaling may be one or more messages of a random access procedure and / or may be packet transmission via a radio bearer established between the first base station and the wireless device in an RRC connected state.

[0348] In one example, the first base station may transmit a tunnel endpoint identifier of the first base station to the anchor base station, and the anchor base station may forward one or more downlink packets for the wireless device to the first base station based at least on the tunnel endpoint identifier. In one example, the first base station may forward the one or more downlink packets to the wireless device via radio signaling. In one example, the radio signaling may be one or more messages of a random access procedure and / or may be packet transmission via a radio bearer established between the first base station and the wireless device in an RRC connected state.

[0349] In one example, the first base station may transmit a first tunnel endpoint identifier of the first base station to a core network entity, and the core network entity may transmit a second tunnel endpoint identifier of the user plane core network entity to the anchor base station. In one example, the anchor base station may forward one or more downlink packets for the wireless device to the user plane core network entity based at least on the second tunnel endpoint identifier, and the user plane core network entity may forward the one or more downlink packets to the first base station based at least on the first tunnel endpoint identifier received from the core network entity. In one example, the first base station may forward the one or more downlink packets to the wireless device via radio signaling. In one example, the radio signaling may be one or more messages of a random access procedure and / or may be packet transmission via a radio bearer established between the first base station and the wireless device in an RRC connected state.

[0350] In an example, the tunnel endpoint identifier of the first base station may be an IP address of the first base station, and the tunnel endpoint identifier of the user plane core network entity may be an IP address of the user plane core network entity.

[0351] In one example, the first base station may transmit a wireless device context request message to the anchor base station via an Xn interface in response to receiving the first core network paging response, and the anchor base station may transmit the wireless device context to the first base station. In one example, the first base station may indirectly transmit a wireless device context request message to the anchor base station via a core network entity in response to receiving the first core network paging response, and the anchor base station may transmit the wireless device context to the first base station via the core network entity.

[0352] In one example, a base station may receive one or more packets for a wireless device in an RRC inactive state from a first network entity. The first base station may perform an RNA paging procedure, including transmitting a first message to one or more second base stations. The first message may include an identifier of the wireless device. The first base station may determine that the RNA procedure is unsuccessful. The first base station may transmit a second message to the second network entity and in response to determining that the RNA paging procedure is unsuccessful, wherein the second message initiates a core network paging procedure. The first base station may receive a third message indicating a data forwarding procedure in response to the core network paging procedure determining that the wireless device may be in a coverage area of ​​the second base station. The first base station may forward the one or more packets to the second base station. In one example, the first network entity may be the second network entity.

[0353] In one example, the forwarding by the first base station to the second base station may employ a direct tunnel between the first base station and the second base station, and / or the one or more packets may be transmitted to a core network node. The first base station may transmit a PDCP sequence number of one of the one or more downlink data packets. The second message may include the sequence number.

[0354] Example of Radio Access Network Area Information

[0355] In example embodiments, a problem with respect to exchanging RNA information between base stations is how a base station obtains RNA information of its neighboring cells or their neighboring base stations and employs the information when the base station initiates a RNA paging procedure for a wireless device in an RRC inactive state.

[0356] In the existing RAN paging procedure, the base station may configure the wireless device with one or more RAN areas (e.g., RAN notification areas, RAN paging areas, one or more cells associated with the RAN areas) for the RRC inactive state. The base station may initiate the RAN paging procedure by transmitting a RAN paging message to one or more base stations when the base station has a packet, control signaling, and / or state transition cause for the wireless device. The wireless device in the RRC inactive state may receive a paging indication from the one or more base stations and / or from the base station based on the one or more RAN areas. The implementation of existing signaling when paging the RRC inactive state wireless device may increase network resource utilization, increase paging delay, increase packet loss rate, and / or increase call drop rate due to the inefficiency of the paging procedure for the wireless device in the RRC inactive state. The existing RAN area coordination may need to further enhance the communication between network nodes (e.g., base stations, core network entities, wireless devices). In one example, the failure rate of transmitting RAN paging messages (e.g., for data packets, NAS / RRC signaling packets) may increase for RRC inactive state wireless devices. Increasing the RAN paging failure rate may degrade the network system reliability. There is a need for improved backhaul signaling for RRC inactive state wireless devices.

[0357] Example embodiments enhance information exchange mechanisms between network nodes to improve network communication reliability and / or efficiency when a wireless device is in an RRC inactive state. Example embodiments may enhance signaling procedures for exchanging RAN area information between base stations. Fig.16 and Fig.17 In the example embodiment shown, the base station may transmit its RAN region information (e.g., a RAN region identifier, a RAN notification identifier, one or more cell information of the RAN region). Based on the RAN region information of neighboring base stations (or neighboring cells), the base station may enhance RAN paging reliability for RRC inactive wireless devices by sending RAN paging messages to neighboring base stations associated with the RAN region of the RRC inactive wireless device. The example embodiment may increase backhaul signaling efficiency by limiting RAN paging message transmission to corresponding base stations associated with the RAN region of the RAN paging target wireless device.

[0358] In one example, a base station may perform an Xn setup procedure to set up an Xn interface with its neighboring base station. The Xn setup procedure may include receiving a first message from a second base station by a first base station, and / or transmitting a second message to the second base station by the first base station in response to the first message. In one example, the first message may be an Xn setup request message, and the second message may be an Xn setup response message. The first message may include at least one of a gNB identifier of the second base station, a cell identifier of a cell served by the second base station, and / or an RNA identifier, wherein the RNA identifier may be associated with the second base station and / or the cell of the second base station. The second message may include at least one of a gNB identifier of the first base station, a cell identifier of a cell served by the first base station, and / or an RNA identifier associated with the first base station and / or the cell of the first base station.

[0359] In one instance, a base station may perform a gNB configuration update procedure to update configuration information of its neighboring base stations. In one instance, the base station may initiate a gNB configuration update procedure at least if a cell is added, modified and / or removed in the base station and / or if RNA information for the base station or for a cell of the base station changes. The gNB configuration update procedure may include receiving a first message from a second base station by a first base station, and / or transmitting a second message to the second base station by the first base station in response to the first message. In one instance, the first message may be a gNB configuration update message, and the second message may be a gNB configuration update confirmation message. The first message may include at least one of a gNB identifier of the second base station, a cell identifier of a cell served by the second base station, and / or an RNA identifier, wherein the RNA identifier may be associated with the second base station and / or the cell of the second base station. The second message may include a confirmation of the first message.

[0360] In one example, the RNA identifier may include RAN notification area information, RAN area information (eg, RAN area identifier), one or more cell identifiers of one or more cells associated with the RAN notification area (eg, RAN area, RAN paging area).

[0361] In an example embodiment, the RNA identifier may be globally and / or identifiable in the PLMN. In one example, the base station may employ the RNA identifier exchanged via the Xn setup procedure and / or the gNB configuration update procedure to determine the paging area for the RNA paging procedure, which may be used to inform the wireless device in the RRC inactive state that at least one of the following events has occurred: the base station receives one or more packets for the wireless device; the wireless device needs to transition its RRC state from the RRC inactive state to the RRC idle state; and / or the wireless device needs to transition its RRC state from the RRC inactive state to the RRC connected state. In one example, the one or more packets may include data packets from a user plane core network entity (e.g., UPF) and / or control signaling (e.g., NAS messages) from a control plane core network entity (e.g., AMF).

[0362] In one example, the base station may transmit RAN notification area information (e.g., a RAN area identifier of a RAN area, a RAN paging area identifier of a RAN paging area, and / or one or more cell identifiers of a RAN notification area, a RAN paging area, and / or one or more cells of a RAN area) to the wireless device. The base station may indicate a state transition from an RRC connected state to an RRC inactive state to the wireless device by transmitting an RRC message (e.g., an RRC connection release message, an RRC connection suspend message). In one example, the RRC message may include RAN notification area information for the wireless device. When the wireless device stays in the RRC inactive state, the wireless device may move around one or more cells of the RAN notification area. When the wireless device stays in the RRC inactive state, the wireless device may move out of the RAN notification area, and a RAN notification area update procedure may be initiated, thereby informing the base station that the wireless device moves to a RAN notification area different from the RAN notification area. The RAN notification area may include the RAN area of ​​a neighboring base station, information of a RAN area received from a neighboring base station via an Xn setup request / response message and / or a gNB configuration update message.

[0363] In one example, the RNA paging procedure may include transmitting a first RNA paging message by a first base station to a plurality of second base stations belonging to an RNA associated with the wireless device, and / or broadcasting / multicasting a second RNA paging message via a radio interface by a plurality of second base stations receiving the first RNA paging message, wherein the first base station may be an anchor base station for the wireless device. In one example, if the wireless device receives the second RNA paging message, it may transmit a first RNA paging response to the base station from which it received the second RNA paging message. After receiving the first RNA paging response, the base station may transmit a second RNA paging response to the first base station, the anchor base station for the wireless device. In one example, the second RNA paging response may include a wireless device context request.

[0364] In an example embodiment, during an RNA paging procedure, a first RNA paging message transmitted from a first base station to a plurality of second base stations may include at least one of the following: an identifier of the wireless device, an AS context identifier for the wireless device, an RNA identifier, and / or a cause of RNA paging for the wireless device to notify the plurality of second base stations of at least one of a downlink packet for the wireless device, a required RRC state transition from an RRC inactive state to an RRC idle state, and / or a required RRC state transition from an RRC inactive state to an RRC connected state. In one example, the first RNA paging message may be transmitted to one or more base stations serving at least one cell belonging to an RNA associated with the wireless device (a target device of the RNA paging procedure). The first base station may determine the one or more base stations (e.g., RAN paging target base stations) based on RNA information received from the one or more base stations. In one example, when the RNA information includes a cell and / or RAN area configured for the wireless device (e.g., when the RRC state is transitioned to an RRC inactive state), the first base station transmits the RAN paging message to the base station transmitting the RNA information.

[0365] In an example embodiment, during the RNA paging procedure, the second RNA paging message broadcast / multicast by the second base station may include at least one of the following: an AS context identifier for the wireless device, an identifier of the wireless device, and / or a cause of RNA paging to notify the wireless device of at least one event of a downlink packet for the wireless device, a required RRC state transition from an RRC inactive state to an RRC idle state, and / or a required RRC state transition from an RRC inactive state to an RRC connected state. In an example, the second RNA paging message may be broadcast and / or multicast in a coverage area of ​​the second base station, in a coverage area of ​​a cell belonging to the RNA, and / or in a coverage area of ​​a beam of a cell belonging to the RNA.

[0366] In an example embodiment, after an RNA paging procedure, in the case where the cause of the RNA paging is the transmission of the one or more packets for the wireless device, if the anchor base station receives a second RNA paging response from a base station that received a first RNA paging response from a wireless device in an RRC inactive state (which is a target device of the RNA paging procedure), the anchor base station may forward the one or more packets to the base station that transmitted the second RNA paging response. In one example, the second RNA paging response may include a UE context retrieval request message for the wireless device. In one example, the second RNA paging response message may include a recovery identifier of the wireless device, and the anchor base station may retrieve the UE context based on the recovery identifier. In one example, the first RNA paging response may include an RRC context recovery / setup request message. The first RNA paging response may include a recovery identifier of a wireless device in an RRC inactive state. The base station that receives the first RNA paging response may identify the anchor base station based on the recovery identifier and may transmit the second RNA paging response message.

[0367] In one example, in the case where the cause of the RNA paging procedure is an RRC state transition of the initiating wireless device, the anchor base station receiving the second RNA paging response may release the UE context of the wireless device. If the RRC state transition is a transition to an RRC connected state, the anchor base station may transmit one or more elements of the UE context of the wireless device to the base station transmitting the second RNA paging response before releasing the UE context. If the RRC state transition is a transition to an RRC idle state, the anchor base station may release the UE context without transmitting at least one element of the UE context to the base station.

[0368] In one example, a first base station may receive a first message including a first radio access network notification area (RNA) identifier associated with the second base station from a second base station. When the first base station is also associated with the first RNA identifier, the first base station may transmit a second message including an identifier of the wireless device to the second base station.

[0369] In one example, a first base station may receive a first message including a first radio access network notification area (RNA) identifier associated with the second base station from a second base station. The first base station may transmit one or more third messages including radio configuration parameters to a wireless device, wherein the radio configuration parameters may include an RNA identifier, and the wireless device may be in a radio resource control (RRC) connected state. The first base station may initiate a procedure for transitioning the wireless device from an RRC connected state to an RRC inactive state. When the first base station is also associated with the first RNA identifier, the first base station may transmit a second message including an identifier of the wireless device to the second base station, wherein the wireless device may be in a radio resource control (RRC) inactive state and configured with the first RNA identifier. The second message may be configured to initiate a third message including an indication broadcast and / or multicast by the second base station. The second message may be configured to initiate a third message including an indication broadcast or multicast by the second base station and in a coverage area or beam area of ​​the second base station.

[0370] In one example, the second message may be a paging message. The indication may be a paging indication. The first base station may further transmit one or more third messages including an identifier of the wireless device to one or more third base stations. The indication may be configured to cause the wireless device to change from an RRC inactive state to an RRC idle state. The indication may be configured to cause the wireless device to change from an RRC inactive state to an RRC connected state. The indication may indicate one or more downlink data packets for the wireless device. The wireless device and / or at least one base station may release a wireless device context. The second base station may receive a fourth message including an RRC connection request from the wireless device. The second base station may transmit a fifth message including a request for a wireless device context to the first base station for the wireless device. The second base station may receive a sixth message including a wireless device context from the first base station.

[0371] In one example, at least one base station may have a wireless device context for a wireless device in an RRC inactive state, and the wireless device may not have an RRC connection with the at least one base station having the wireless device context. The wireless device context may include at least one of bearer configuration information, logical channel information, security information, PDCP configuration information, AS context, and one or more parameters of the wireless device. The RNA identifier may be associated with a cell of a second base station. When at least one cell in a first base station is associated with a first RNA identifier, the first base station may also be associated with the first RNA identifier. The first base station may be associated with multiple RNA identifiers. The first base station may transmit a message including the first RNA identifier to the second base station. The first base station may transmit a second message in response to receiving at least one data or control packet from a core network entity. The first base station may receive a message including the first RNA identifier from a network entity.

[0372] Example of radio access network paging area configuration

[0373] In an example embodiment, a problem with respect to determining an area for RNA paging is how a base station transmits a paging message to a wireless device in an RRC inactive state by broadcasting the paging message in a limited area to achieve signaling efficiency.

[0374] In the existing RAN paging procedure, the base station exchanges backhaul signaling to transmit downlink packets to the wireless device in the RRC inactive state. The base station may transmit the paging message via its cell and / or transmit the paging message to its neighboring base station of the RAN notification area associated with the wireless device. The implementation of the existing backhaul signaling may result in increased network resource utilization due to the inefficiency of RAN paging message transmission. The inefficient RAN paging procedure may require further enhancement of the communication and / or control mechanism of the network node (e.g., base station, core network entity, wireless device). In one example, the increased signaling load of the RAN paging procedure to wake up the RRC inactive state wireless device may increase the backhaul signaling delay and may reduce the signaling reliability. The increased packet loss rate due to the signaling overhead may degrade the network system reliability. It is necessary to improve the backhaul signaling mechanism for the RAN paging procedure for the RRC inactive state wireless device. The example embodiment enhances the RAN paging mechanism by enabling the base station to adopt the duration of the signaling since the RAN paging target wireless device in the RRC inactive state when selecting the RAN paging target base station. In an example, by transmitting the RAN paging message to a neighboring base station that most recently communicated with the wireless device, the base station can avoid unnecessary signaling of the RAN paging message to other base stations that would be less likely to be selected by the RAN paging target wireless device.

[0375] In such Fig.18 and Fig.19 In the illustrated example embodiment, a base station (e.g., an anchor base station, gNB) may determine a duration between receiving / transmitting a most recent packet from / to a wireless device and receiving a packet from a core network entity (e.g., AMF) of the wireless device. In one example, the packet from the core network entity may cause the base station to initiate a RAN paging procedure. Based on the duration, the base station may select a target base station to which the base station transmits a RAN paging message for the wireless device. In one example, when the duration is less than and / or equal to a first time value, the base station may transmit the RAN paging message to a second base station that sent / received the most recent packet to / from the base station. In one example, when the duration is greater than the first time value, the base station may transmit the RAN paging message to a third base station that belongs to a RAN notification area associated with the wireless device. In one example, the third base station may include the second base station.

[0376] In one example, if Fig. 20 and Fig.21 As shown in , if the base station receives / transmits the most recent packet from the wireless device via its cell, then when the duration is less than and / or equal to the first time value, the base station may transmit a RAN paging message (e.g., radio interface paging) via its cell, and when the duration is greater than the first time value, the base station may transmit the RAN paging message to a second base station belonging to the RAN notification area associated with the wireless device.

[0377] In an example embodiment, by limiting the RAN paging area based on the duration since the most recent communication with the wireless device, the base station may reduce signaling overhead for unnecessary RAN paging message transmissions.

[0378] In an example embodiment, the first base station may determine the paging area of ​​the RNA paging procedure and / or the core network paging procedure targeting the wireless device in the RRC inactive state based at least on the duration between the latest signaling for the wireless device and the occurrence of the event requiring the transmission of the paging message, and the first base station may transmit the paging message in the determined paging area. The first paging timer may be configured in the base station. The base station may restart the first paging timer in response to receiving and / or transmitting a paging message and / or predefined signaling (e.g., uplink data transmission, random access preamble, downlink data transmission, ACK, etc.) between the first base station and the wireless device. For example, if the paging process is started when the first paging timer is in operation, the base station may consider the previous position of the wireless device. When the paging process starts after the timer expires, the base station may page the wireless device in the RNA area or the core TA area.

[0379] In one example, the first base station may determine the paging area based on at least one of: a moving speed of the paging target wireless device, a service type of the paging target wireless device (e.g., a logical channel type, a bearer type, a slice type, etc.), subscription information of the paging target wireless device, a cause of establishing the paging target wireless device, mobility information of the paging target wireless device, and / or mobility estimation information of the paging target wireless device.

[0380] In one example, the determined paging area may be at least one of one or more base stations in the RNA, one or more cells of a base station in the RNA, and / or one or more beams of a cell operated by a base station in the RNA. In one example, if the determined paging area belongs entirely or partially to the coverage area of ​​one or more second base stations, the first base station that determines the paging area may transmit a first paging message to the one or more second base stations, and the one or more second base stations may broadcast and / or multicast a second paging message in its coverage area. In one example, if the determined paging area belongs entirely or partially to the coverage area of ​​the first base station that determines the paging area, the first base station may broadcast and / or multicast a second paging message in its coverage area. In one example, if the determined paging area belongs only to the coverage area of ​​the first base station, the first base station may not transmit the first paging message.

[0381] In one example, if the determined paging area belongs to the coverage area of ​​the first cell of the first base station, the first base station may broadcast and / or multicast the second paging message in the first cell. In one example, if the determined paging area belongs to the coverage area of ​​the first beam in the first cell of the first base station, the first base station may broadcast and / or multicast the second paging message in the first beam.

[0382] In one example, a first paging message transmitted from a first base station to the one or more second base stations may include at least one of a wireless device identifier and / or an RNA identifier of a wireless device targeted for paging, and a second paging message broadcast and / or multicast by the first base station and / or the one or more second base stations may include the wireless device identifier. In one example, a base station receiving the first paging message with the RNA identifier may broadcast and / or multicast the second paging message in a coverage area of ​​a cell associated with the RNA identified by the RNA identifier.

[0383] In one example, the latest signaling to the wireless device may be a signaling message transmitted for at least the following procedures: a random access procedure for uplink and / or downlink packet transmission (e.g., data and / or control packets) to the wireless device, uplink and / or downlink packet transmission and / or confirmation signaling, an RNA update and / or tracking area update procedure initiated by the wireless device, an RRC state transition from an RRC connected state to an RRC inactive state, and / or a paging and / or response procedure.

[0384] In one example, the event requiring the transmission of a paging message may be at least one of the following events: reception of a downlink packet for the wireless device (e.g., data and / or control packets), an event requiring an RRC state transition of the wireless device to an RRC connected state (e.g., reception of one or more downlink packets for a service requiring an RRC connected state, receipt of a command from a core network entity requesting an RRC connected state for the wireless device, expiration of a timer for an RRC inactive state, a high load of random access procedure attempts, and / or other abnormal events), and / or an event requiring an RRC state transition of the wireless device to an RRC idle state (e.g., receipt of a command from a core network entity requesting an RRC idle state for the wireless device, expiration of a timer for an RRC inactive state, a high load of random access procedure attempts, and / or other abnormal events).

[0385] In one example, a random access procedure for uplink and / or downlink packet transmission may be initiated by a wireless device in an RRC inactive state at least when its buffer has one or more packets to be transmitted and / or when the wireless device receives a paging message for one or more downlink packets from a base station. In one example, the random access procedure may be performed with two messages (e.g., level 2 random access) and / or four messages (e.g., level 4 random access).

[0386] In a level 2 random access procedure, a first message may be transmitted by a wireless device to a base station, and the first message may include at least one of a random access preamble and / or one or more uplink packets. A second message of the level 2 random access procedure may be transmitted to the wireless device by a base station that receives the first message, and the second message may include a confirmation of reception of the one or more uplink packets. In an example, the second message of the level 2 random access procedure may further include a resource grant for further uplink packet transmission, and the wireless device may transmit a third message including one or more packets based at least on the resource grant. The base station that receives the third message may transmit a confirmation and / or a further resource grant for further uplink packet transmission. In an example, further resource grants by the base station and the wireless device may be associated with uplink packet transmissions via further messages.

[0387] In a level 4 random access procedure, a first message may be transmitted by a wireless device to a base station, and the first message may include at least one of a random access preamble and / or one or more uplink packets. A second message of the level 4 random access procedure may be transmitted by a base station receiving the first message to a wireless device, and the second message may include a resource grant for uplink packet transmission. A third message of the level 4 random access procedure may be transmitted by a wireless device to a base station based at least on the resource grant in the second message, and may include one or more uplink packets. A fourth message transmitted by the base station to the wireless device may include a confirmation of reception of the one or more uplink packets. In an example, the fourth message of the level 4 random access procedure may further include another resource grant for further uplink packet transmission, and the wireless device may transmit a fifth message including one or more packets based at least on the another resource grant in the fourth message. The base station receiving the fifth message may transmit a confirmation and / or a further resource grant for further uplink packet transmission. In an example, further resource grants by the base station and the wireless device may be associated with uplink packet transmission via further messages.

[0388] In an example, an RNA update procedure may be initiated by a wireless device in an RRC inactive state at least when the wireless device selects a cell belonging to a new RNA and / or when a time threshold for periodic RNA updates expires. In an example, the base station may configure the wireless device to periodically perform RNA updates when the time threshold expires. In an example, a cell may broadcast one or more RNA identifiers of one or more RNAs associated with the cell, and the wireless device may determine whether one of the broadcasted one or more RNA identifiers is the same as its RNA identifier assigned in at least one of a cell in which the wireless device performed a latest RNA update procedure, a cell in which the wireless device performed a latest uplink and / or downlink packet transmission, and / or a cell in which the wireless device was most recently in an RRC connected state.

[0389] In one example, the RNA update procedure may include at least one of a random access procedure initiated by the wireless device in an RRC inactive state, a wireless device context extraction procedure initiated by the new base station, a path switching procedure initiated by the new base station, and / or storage of an RNA identifier of the new RNA by the wireless device. In one example, the wireless device context extraction procedure may include requesting the wireless device context of the wireless device initiating the RNA update procedure from the old anchor base station of the wireless device by the new base station, and / or receiving the wireless device context from the old anchor base station by the new base station. In one example, the wireless device context may include at least one of an AS context, bearer configuration information, security information, PDCP configuration information, and / or other configuration information of the wireless device. In one example, the path switching procedure may include requesting the new base station to update a downlink tunnel endpoint identifier for one or more bearers established for the wireless device between the user plane core network entity and the RAN node (e.g., changing the downlink tunnel endpoint identifier from the address of the old anchor base station to the address of the new base station).

[0390] In one example, a tracking area update procedure may be initiated by a wireless device in an RRC inactive state (and / or in an RRC idle state) at least when the wireless device selects a cell belonging to a new tracking area and / or when a time threshold for periodic tracking area updates expires. In one example, a core network entity may configure the wireless device to periodically perform tracking area updates when the time threshold expires. In one example, a cell may broadcast one or more tracking area identifiers of one or more tracking areas associated with the cell, and the wireless device may determine whether one of the broadcasted one or more tracking area identifiers is the same as a tracking area identifier assigned in at least one of a cell in which the wireless device performed a most recent tracking area update procedure, a cell in which the wireless device performed a most recent uplink and / or downlink packet transmission, and / or a cell in which the wireless device was most recently in an RRC connected state.

[0391] In one example, the RRC state transition from the RRC connected state to the RRC inactive state may be accomplished by a first RRC message transmitted by the base station to the wireless device in the RRC connected state. The first RRC message may include a command for the RRC state transition of the wireless device. In one example, the wireless device may transmit a confirmation via a second RRC message, a MAC layer message, and / or a physical layer message.

[0392] In one example, the paging and response procedure may include a paging message broadcast / multicast by the base station for RNA paging and / or core network paging and / or random access procedure. The random access procedure may be a level 2 random access procedure and / or a level 4 random access procedure.

[0393] In one example, the downlink packet reception for the wireless device may be receiving one or more packets for the wireless device from a core network entity and / or an anchor base station. The downlink packet reception for the wireless device may require an RNA paging procedure. In one example, the base station receiving the one or more packets may measure the duration of the occurrence of the latest signaling and downlink packet reception for the wireless device, and may determine a paging area for RNA paging.

[0394] In one example, the event in the base station that requires an RRC state transition of the wireless device to the RRC connected state may be at least one of receiving one or more downlink packets for the wireless device, receiving an RRC state transition request for the wireless device from a core network entity, and / or a decision of the base station on the RRC state transition. In one example, the base station may measure the duration from the latest signaling to the wireless device and the occurrence of the event requiring the RRC state transition, and may determine the paging area for RNA paging and / or core network paging.

[0395] In one example, the event in the base station that requires an RRC state transition of the wireless device to the RRC idle state can be one of receiving an RRC state transition request for the wireless device from a core network entity and / or a decision of the base station on the RRC state transition. In one example, the base station can measure the duration from the latest signaling to the wireless device and the occurrence of the event requiring the RRC state transition, and can determine the paging area for RNA paging and / or core network paging.

[0396] In one example, a first base station may receive or transmit a first message associated with a wireless device in an RRC inactive state. The first base station may determine which selected base station is selected by the wireless device. The first base station may receive a downlink data packet for the wireless device from a core network node. The first base station may determine whether a duration between receipt of the first message and receipt of the downlink data packet is less than a first time period. When the first base station is the same as the selected base station and when the determination indicates that the duration is less than the first time period, the first base station may transmit one or more second messages including at least one of the downlink data indications and at least one of the one or more downlink data packets.

[0397] In one example, when the first base station is the same as the selected base station and when the determination indicates that the duration is not less than the first time period, the first base station may transmit one or more third messages including indications of downlink data to the plurality of base stations. When the first base station is different from the selected base station and when the determination indicates that the duration is less than the first time period, the first base station may transmit one or more second messages including at least one of the downlink data indications and at least one of the one or more downlink data packets to the second base station. When the first base station is different from the selected base station and when the determination indicates that the duration is not less than the first time period, the first base station may transmit one or more third messages including indications of downlink data to the plurality of base stations.

[0398] In one example, the first message may be at least one uplink signaling transmission of: an uplink data transmission procedure in an RRC inactive state, a downlink data transmission procedure in an RRC inactive state, an RNA update procedure, and / or a procedure for an RRC state transition from an RRC connected state to an RRC inactive state. The first time period may be defined based at least on a moving speed of the wireless device. The limited area may be determined based at least on one of: a moving speed of the wireless device, a size of a cell in which the one or more first messages are transmitted, and / or a size of a beam area in which the one or more first messages are transmitted. At least one base station may have a UE context for the wireless device in the RRC inactive state, and the wireless device in the RRC inactive state may not have an RRC connection with the at least one base station having a UE context.

[0399] Example of cell selection for an inactive wireless device

[0400] In an example embodiment, an issue with respect to cell selection by a wireless device in an RRC inactive state or an RRC idle state is how the wireless device determines cells that support services that the wireless device is likely to receive in order to reduce further signaling assigning cells that provide the services.

[0401] In the existing network mechanism, a wireless device in an RRC inactive state may select / reselect a cell to be camped on based on the received power and / or quality from one or more cells. The wireless device may adopt a certain type of service (e.g., network slicing, bearer, logical channel, QoS flow, PDU session). In one example, a cell may not support a specific type of service. For example, a cell may support different types of parameter sets, TTIs, subcarrier spacing configurations, and / or approved / unapproved spectrums. The different types of parameter sets, TTIs, subcarrier spacing configurations, and / or approved / unapproved spectrums may be used for specific types of services. In one example, a small TTI configuration may support URLLC type services (network slicing) for low latency requirements, and / or unapproved spectrum may not support URLLC type services due to its smaller reliability. In one example, some limited cells may support configured grant type 1 (e.g., no grant uplink resources), which may be required for URLLC services and / or IoT (e.g., MTC) services.

[0402] In one example, if a wireless device selects / reselects a cell that does not support a service type required by the wireless device, the wireless device may need to increase signaling to the base station to reselect a cell that supports the service type and / or perform a handover or secondary cell addition procedure to adopt a cell that supports the service type. The increased signaling caused by selecting a cell that does not support the required service type may increase communication delay, packet loss rate and / or communication reliability. Example embodiments enhance the cell selection / reselection procedure by enabling a base station to configure an association between a cell (e.g., cell type, registration area, parameter set, TTI, subcarrier spacing, spectrum band) and a service type (e.g., network slice, bearer, logical channel, QoS flow, PDU session) for a wireless device in an RRC inactive state (and / or an RRC idle state).

[0403] In one example, in the RRC idle state, the wireless device may not have activated logical channels (and / or bearers), and the wireless device may need an RRC connection to transmit / receive data for services. Unlike the RRC idle state, in the RRC inactive state, the wireless device may be configured to have one or more logical channels (and / or one or more bearers), and the wireless device may have a configured buffer to queue packets associated with the one or more logical channels in the RRC inactive state (without transitioning to the RRC connected state).

[0404] In an example embodiment, if Fig. 22 , Fig.23 and Fig.24As shown in , a cell may or may not support a service for a wireless device. The service may be associated with at least one of a logical channel, bearer, slice, UE type, and / or classification type for packet transmission. In an example, a base station may configure the wireless device to adopt one or more cells and / or cell types to transmit packets for a logical channel. The configuration may be provided to the wireless device via one or more dedicated RRC messages and / or one or more broadcast / multicast system information messages. In an example, a base station may broadcast / multicast a cell identifier and / or cell type information via a system information message of the cell. In an example, a cell of a base station may broadcast / multicast a list of restricted and / or allowed services (e.g., a list of logical channel types, a list of bearer types, and / or a list of slices). In one example, a wireless device in an RRC inactive state and / or an RRC idle state may select a cell based at least on information broadcast / multicast by a cell for at least one of the following purposes: receiving a paging message of an RNA paging and / or a core network paging (e.g., a tracking area paging) for receiving one or more downlink packets and / or an RRC state transition command, transmitting one or more uplink packets, and / or initiating an RRC state transition to an RRC connected state. In one example, when a wireless device in an RRC inactive state obtains data for a first logical channel (e.g., a first bearer) in a corresponding buffer, the wireless device may select / reselect a cell configured by a base station for the first logical channel (or the first bearer), and may transmit data to the base station via the cell. In one example, when a wireless device in an RRC inactive state obtains data for a first service type (e.g., a first network slice) in a corresponding buffer, the wireless device may select / reselect a cell configured by a base station for the first service type (or the first network slice), and may transmit data to the base station via the cell. The cells may be configured into registration areas, cell types (eg, parameter sets, TTIs, subcarrier spacing, spectrum bands), and the like.

[0405] In one example, the wireless device may receive / transmit one or more packets from / to a base station via one or more logical channels and / or one or more bearers for one or more services. When the base station establishes a radio bearer and / or a logical channel for the wireless device, the base station may provide the wireless device with a list of cells and / or cell types that can be used to transmit one or more packets associated with the logical channel and / or bearer. In one example, if the wireless device is in an RRC connected state, the list of cells and / or cell types for logical channels and / or bearers may be transmitted via one or more RRC messages. In one example, the list of cells and / or cell types for logical channels and / or bearers may be transmitted via one or more MAC CEs. In one example, a cell may broadcast / multicast a list of one or more restricted and / or allowed logical channel types, bearer types, and / or slice types, wherein the list may be transmitted via one or more system information messages.

[0406] In one example, a wireless device in an RRC inactive state may select a cell to further receive an RNA paging message or a core network paging message. The RNA paging message or the core network paging message may be transmitted by a base station to transmit one or more downlink packets to the wireless device, and the one or more downlink packets are associated with a logical channel and / or a bearer. If the wireless device selects a cell that does not support a logical channel and / or a bearer, the base station may assign another cell to the wireless device to transmit the one or more downlink packets after the wireless device responds to the paging message. In one example, if the wireless device selects a cell that can support a logical channel and / or a bearer, the base station may not need to assign another cell to transmit the one or more downlink packets.

[0407] In an example, if a first logical channel and / or bearer is established for the wireless device and if one or more cells and / or cell types are configured by the base station for the first logical channel and / or bearer, the wireless device in the RRC inactive state may select one of the one or more cells and / or cell types for further downlink packet reception associated with the first logical channel and / or bearer based at least on a cell identifier and / or cell type broadcast / multicast in the cell. In an example, the wireless device may not select a cell in which the first logical channel and / or bearer is associated with a list of one or more restricted logical channel types, bearer types, and / or slice types based at least on information broadcast / multicast from the cell. In an example, the wireless device may select a cell in which the first logical channel and / or bearer is associated with a list of one or more allowed logical channel types, bearer types, and / or slice types based at least on information broadcast / multicast from the cell.

[0408] In one example, the wireless device in the RRC idle state may select a cell to further receive a core network paging message. The core network paging message may be transmitted by the base station to transmit one or more downlink packets to the wireless device, the one or more downlink packets being associated with a logical channel type and / or a bearer type. In one example, if the wireless device in the RRC idle state selects a cell that can support a logical channel and / or bearer for a service that the wireless device can receive, the base station may not need to assign another cell to transmit the one or more downlink packets after the wireless device responds to the core network paging message.

[0409] In an example, if one or more cells and / or cell types are configured by the base station for a first logical channel type and / or bearer type, the wireless device after transitioning to the RRC idle state may select one of the one or more cells and / or cell types for further downlink packet reception associated with the first logical channel type and / or bearer type based at least on a cell identifier and / or cell type broadcast / multicast in the cell. In an example, the wireless device may not select a cell in which the first logical channel type and / or bearer type is associated with a list of one or more restricted logical channel types, bearer types, and / or slice types based at least on information broadcast / multicast from the cell. In an example, the wireless device may select a cell in which the first logical channel type and / or bearer type is associated with a list of one or more allowed logical channel types, bearer types, and / or slice types based at least on information broadcast / multicast from the cell.

[0410] In one example, a wireless device in an RRC inactive state may select a cell to further transmit one or more uplink packets to the network. In one example, the wireless device may transmit one or more uplink packets to the base station via one or more random access procedures in the selected cell, the one or more uplink packets being associated with a logical channel and / or a transport. If the wireless device selects a cell that does not support the logical channel and / or the transport, the base station may assign another cell to the wireless device to receive the one or more uplink packets. In one example, if the wireless device selects a cell that can support the logical channel and / or the transport, the base station may not need to assign another cell to receive the one or more uplink packets.

[0411] In an example, if a first logical channel and / or bearer is established for the wireless device and if one or more cells and / or cell types are configured by the base station for the first logical channel and / or bearer, the wireless device in the RRC inactive state may select one of the one or more cells and / or cell types for further uplink packet transmission associated with the first logical channel and / or bearer based at least on a cell identifier and / or cell type broadcast / multicast in the cell. In an example, the wireless device may not select a cell in which the first logical channel and / or bearer is associated with a list of one or more restricted logical channel types, bearer types, and / or slice types based at least on information broadcast / multicast from the cell. In an example, the wireless device may select a cell in which the first logical channel and / or bearer is associated with a list of one or more allowed logical channel types, bearer types, and / or slice types based at least on information broadcast / multicast from the cell.

[0412] In one example, a wireless device in an RRC inactive state and / or an RRC idle state may select a cell to initiate an RRC state transition to an RRC connected state. The wireless device may perform a random access procedure to make an RRC connection in a selected cell. After completing the RRC state transition, the wireless device may transmit and / or receive one or more packets associated with a logical channel and / or a transport. In one example, if the wireless device selects a cell that does not support logical channels and / or transport, the base station may assign another cell to the wireless device to transmit and / or receive the one or more packets after completing the RRC state transition. In one example, if the wireless device selects a cell that can support logical channels and / or transport, the base station may not need to assign another cell to transmit and / or receive the one or more packets.

[0413] In an example, if a first logical channel and / or bearer is established for the wireless device and if one or more cells and / or cell types are configured by the base station for the first logical channel and / or bearer, the wireless device in the RRC inactive state may select one of the one or more cells and / or cell types for further packet transmission and / or reception associated with the first logical channel and / or bearer based at least on a cell identifier and / or cell type broadcast / multicast in the cell after completing the RRC state transition to the RRC connected state. In an example, the wireless device may not select a cell in which the first logical channel and / or bearer is associated with a list of one or more restricted logical channel types, bearer types, and / or slice types based at least on information broadcast / multicast from the cell. In an example, the wireless device may select a cell in which the first logical channel and / or bearer is associated with a list of one or more allowed logical channel types, bearer types, and / or slice types based at least on information broadcast / multicast from the cell.

[0414] In an example, if one or more cells and / or cell types are configured by the base station for a first logical channel type and / or bearer type, the wireless device after transitioning to the RRC idle state may select one of the one or more cells and / or cell types for further packet transmission and / or reception associated with the first logical channel type and / or bearer type based at least on the cell identifier and / or cell type broadcast / multicast in the cell. In an example, the wireless device may not select a cell in which the first logical channel type and / or bearer type is associated with a list of one or more restricted logical channel types, bearer types, and / or slice types based at least on information broadcast / multicast from the cell. In an example, the wireless device may select a cell in which the first logical channel type and / or bearer type is associated with a list of one or more allowed logical channel types, bearer types, and / or slice types based at least on information broadcast / multicast from the cell.

[0415] In an example, a wireless device may receive a first message including a configuration parameter from a base station, wherein the configuration parameter may indicate an association of a bearer or logical channel with one or more cells of the wireless device in an RRC connected state. The wireless device may receive a second message including an RRC state transition command from the base station, wherein the RRC state transition command is configured to cause an RRC state transition of the wireless device from the RRC connected state to the RRC inactive state. The wireless device in the RRC inactive state may select a first cell based at least on one or more criteria, wherein the one or more criteria may employ at least the configuration parameter. The wireless device may transmit a random access preamble message to the base station via the first cell. The wireless device in the RRC connected state may have an RRC connection with at least one base station. When the wireless device is in the RRC inactive state, at least one base station may have a wireless device context of the wireless device, and / or the wireless device may not have an RRC connection with the at least one base station having the wireless device context. The wireless device context may include at least one of bearer configuration information, logical channel information, security information, AS context, PDCP configuration information, and other information of the wireless device. The transmitting of the random access preamble message may be in response to at least one of: an uplink buffer containing one or more data packets, the wireless device receiving a paging indication, and / or the wireless device detecting movement to a new RNA or TA. The association of the bearer or logical channel with one or more cells may include an association of the bearer or logical channel with a cell type and / or a cell in a frequency band.

[0416] Instances of Radio Access Network Notification Area Update Failures

[0417] Example embodiments provide methods and systems for determining failure of periodic RNA updates in base stations and wireless devices. Example embodiments provide mechanisms for base stations to transmit notification of failure to core network entities. Example embodiments provide processing in wireless devices when periodic RNA update procedures fail.

[0418] In an existing RAN Notification Area Update (RNAU) procedure, a base station and / or a wireless device may exchange signaling to update location information of a wireless device in an RRC inactive state. The wireless device may transmit an RNAU indication to a base station to update its RAN notification area, which may be employed by a base station (e.g., an anchor base station) to page the wireless device in the RRC inactive state. The implementation of existing signaling may result in increased communication delays, increased packet loss rates, and / or increased call drop rates due to inefficient packet transmission for wireless devices in an RRC inactive state and / or an RRC idle state.

[0419] In the RRC idle state of the wireless device, the core network entity may recognize that the wireless device is unreachable by the base station, and the core network entity may not transmit packets for the wireless device to the base station before initiating the core network paging procedure. Unlike the RRC idle state, when the wireless device is in the RRC inactive state, the core network entity may consider that the wireless device has an RRC connection with the base station, and may transmit packets for the wireless device to the base station when the wireless device is unreachable by the base station. In existing network signaling, when the RAN notification area update procedure fails, the core network entity may keep sending packets for the RRC inactive state wireless device to the anchor base station, although the anchor base station is not sure whether the wireless device is reachable. An example embodiment may prevent the core network entity from transmitting packets toward the base station by informing the core network entity of the wireless device status when the wireless device is unreachable.

[0420] For example, when there is a failure in the periodic RNAU procedure, there is a need to further enhance the communication between network nodes (e.g., base stations, core network entities, wireless devices). In an example, in some scenarios, the periodic RNAU update procedure of the wireless device may increase the failure rate in the process of transmitting downlink user plane or control plane packets (e.g., data packets, NAS / RRC signaling packets) for the RRC inactive wireless device. The increased packet loss rate and / or increased transmission delay may degrade the network system reliability. There is a need to improve the backhaul signaling mechanism for the RRC inactive wireless device. Example embodiments enhance the information exchange between network nodes when the wireless device is in the RRC inactive state to improve the network communication reliability. Example embodiments may enhance the signaling procedure when the RAN notifies that the area update procedure has failed.

[0421] In an example embodiment, after transitioning the RRC state from the RRC connected state to the RRC inactive state, the wireless device may periodically perform a RAN Notification Area Update (RNAU) procedure by sending an RNAU indication to the anchor base station. The anchor base station receiving the RNAU indication may consider the wireless device in the RRC inactive state to stay in the RAN notification area associated with the anchor base station, and / or may consider the wireless device to be in a reliable service area of ​​a cell (e.g., reachable) in the RAN notification area. During the RRC inactive state, the core network entity (e.g., AMF and / or UPF) may consider the wireless device to have an RRC connection with the anchor base station, and may send downlink packets (e.g., data packets and / or control signaling packets, NAS messages) to the anchor base station. In an example embodiment, when the anchor base station recognizes that the RNAU procedure (e.g., the periodic RNAU procedure) of the RRC inactive state wireless device has failed, the anchor base station may indicate the RNAU failure to the wireless device and / or the wireless device is unreachable (e.g., a UE context release request indicating a state transition of the wireless device to the RRC idle state).

[0422] Example embodiments may enhance system reliability by enabling a base station to inform a core network entity of a wireless device state when a RAN Notified Area Update procedure for a wireless device in an RRC Inactive state fails. Example embodiments may enable a network node to reduce packet loss or call drop rates for RRC Inactive and / or RRC Idle state wireless devices in the event of a RAN Notified Area Update failure.

[0423] In conventional LTE, the NAS identifier (usually S-TMSI) can be used to address the UE (wireless device) in the paging procedure. In the case of Rel-14 optical connection WI and the introduction of RAN initiated paging, it may have been agreed that when paging is initiated in the RAN, the RAN assigned UE identity (recovery identity) can be used in the RRC paging message. One of the reasons behind this agreement may be the potential security issues in case the NAS identity (S-TMSI) may be exposed on the radio interface without the CN having control over this.

[0424] In NR (New Radio), similar security issues are likely to arise due to exposure of the NAS identity over the radio interface. Furthermore, the use of NAS identifiers at RAN initiated paging may also result in additional signaling between the RAN and the CN, as a mechanism for frequent updates of the NAS identity may be required. It is also possible that the update mechanism may be more complex, as a recovery procedure may be required if reallocation of the NAS identity fails.

[0425] For the reasons stated above, the UE may be addressed at RAN initiated paging using the RAN assigned UE identity (Recovery Identity). A UE in RRC_INACTIVE may normally be paged from the RAN, however for robustness purposes, a UE in RRC_INACTIVE may also need to be reached by CN initiated paging. To resolve state inconsistency scenarios where the UE is in RRC_INACTIVE but the network considers the UE to be idle (e.g. if the UE is temporarily out of coverage when a release message is sent), a UE in RRC_INACTIVE may need to respond on a CN initiated paging containing its NAS identifier.

[0426] The UE may need to monitor and respond to RAN initiated paging as well as CN initiated paging (when in RRC_INACTIVE). RAN initiated paging messages may contain the RAN assigned UE identity, while CN initiated paging messages are sent with the CN assigned (NAS) identity.

[0427] However, when receiving an RRC Paging message while in RRC_INACTIVE, the UE may behave the same, irrespective of whether the paging procedure was triggered in the RAN or in the CN, i.e. independently of the UE identifier contained in the message. That is, the UE may utilize the stored AS context and may attempt to resume the RRC connection by sending an RRC Connection Resumption Request message (or equivalent) to the gNB identifying itself with the RAN-assigned UE Identity sent to the UE once the UE may transition to RRC_INACTIVE.

[0428] When the AS context is successfully retrieved from the network, the UE may transition to RRC_CONNECTED as part of the recovery procedure, see below Fig.16 .

[0429] If the AS context cannot be retrieved in the network for some reason and therefore the recovery of the RRC connection fails, a fallback procedure may be proposed where the gNB triggers the RRC connection establishment procedure due to the recovery failure. Fig.17 The signaling flow for this scenario is shown in .

[0430] In one example, if the recovery attempt fails, it does not add any extra round-trip cost between the UE and the network compared to the normal RRC connection establishment procedure triggered from RRC_IDLE (the UE may send an RRC Connection Request message instead of an RRC Connection Recovery Request message).

[0431] The fact that the UE may keep the AS context until informed by the network (upon reception of the RRC connection setup message) may also be viewed as a safer solution compared to a solution where the AS context may simply be released upon reception of a paging message.

[0432] The paging procedure may also be initiated from the CN if, for example, the UE may be temporarily out of coverage when the release message is sent.

[0433] The following is an example call flow. There may be additional messages (not shown in the call flow) transmitted between network nodes.

[0434] In such Fig.25 and Fig.26 In the illustrated example embodiment, a first base station may transmit to a wireless device at least one first message indicating a radio resource control (RRC) state transition of the wireless device from a RRC connected state to an RRC inactive state. The at least one first message may include a parameter indicating a value associated with a wireless device RAN notification area update timer for a periodic radio access network (RAN) notification area update procedure. In an example, the first base station may be an anchor base station for the wireless device. The first base station may maintain a UE context for the wireless device. The UE context may include at least one of a PDU session configuration, a security configuration, a radio bearer configuration, a logical channel configuration, a recovery identifier associated with the RRC inactive state, RAN notification area information (e.g., a RAN area identifier, a cell identifier, a base station identifier of a RAN notification area of ​​the wireless device).

[0435] In one example, a wireless device in an RRC inactive state may perform an RNA update procedure when a UE RNA update timer (periodic RAN notification area update timer value) expires. Periodic RNA may be configured for the wireless device by the base station. The UE RNA update timer may be configured and / or (re)started when the wireless device makes an RRC connection, when performing an RNA update procedure, and / or via one or more signaling messages between the wireless device and the base station. In one example, the UE RNA update timer may be configured based on the mobile speed of the wireless device, the network slice, the UE type, the established bearer type and / or the service type. The base station may transmit one or more messages including configuration parameters such as RNA timer values ​​and / or RNA counters. The RNA timer and / or counter may be restarted when the UE successfully transmits an RNA update to the base station.

[0436] In one example, the wireless device may be unable to initiate an RNA update procedure when the UE RNA update timer expires due to multiple reasons (e.g., multiple system errors, moving out of network coverage, and / or power outage). In one example, if the network RNA update timer expires without receiving an RNA update message from the wireless device in an RRC inactive state and / or if the first base station does not receive a number of RNA update messages exceeding a periodic RNA update counter, the first base station may determine that the periodic RNA update is unsuccessful. In one example, when a first number (e.g., subsequent) of expected periodic RNA update messages have not been received, the base station may consider the periodic RNA update to be unsuccessful. In one example, the network RNA update timer may be longer than the UE RNA update timer. When one or more periodic RNA update procedures of the wireless device fail, the base station (e.g., an anchor base station) may determine that the periodic RNA update of the wireless device has failed. The determination of the periodic RNA update failure by the base station may be based on the expiration of a network RNA update timer (e.g., a RAN notification area update protection timer).

[0437] In one example, the first base station may start the network RNA update timer in response to receiving an RNA update indication from the wireless device. The RNA update indication may include an RRC connection recovery message from the wireless device, a UE context retrieval request message from a base station where the wireless device resides, an Xn message indicating an RNA update for the wireless device, etc. In one example, the first base station may start the network RNA update timer in response to communicating with the wireless device (e.g., transmitting one or more packets to / receiving one or more packets from the wireless device). In one example, the first base station may stop the network RNA update timer in response to communicating with the wireless device.

[0438] After determining that the periodic RNA update is unsuccessful, the first base station may transmit a first message to the core network entity. The first message may include at least one of the following: a wireless device identifier of the wireless device that failed in the periodic RNA update, an AS context identifier of the wireless device, an RNA update failure indication for the wireless device, a wireless device context release indication for the wireless device in the first base station, an RRC state transition indication notifying the wireless device of the RRC state transition to the RRC idle state, a recovery ID of the wireless device, and / or a core network paging request for the wireless device. In one example, after transmitting the first message, the first base station may release the wireless device context (UE context). In one example, the first message may include a UE context release request message for the wireless device. The first message may include a cause information element indicating that the wireless device is unreachable, the wireless device is in the RRC idle state, and / or the periodic RAN notification area update of the wireless device failed.

[0439] In an example, the core network entity can release the UE context of the wireless device in response to receiving the first message from the base station (eg, the anchor base station).

[0440] In one example, a core network entity that receives a first message from a first base station indicating that a periodic RNA update of a wireless device has failed may configure the RRC state of the wireless device to an RRC idle state. In one example, the core network entity may maintain the RRC state of the wireless device to an RRC inactive state. In one example, the core network entity that receives the first message may transmit a first core network paging message to multiple base stations. The first core network paging message may include at least one of the following: a wireless device identifier, an AS context identifier of the wireless device, a tracking area identifier (and / or a tracking area code), a base station identifier of the first base station, an RNA identifier associated with the wireless device, a cause of the core network paging, a recovery ID of the wireless device, and / or an action indication for the wireless device. In one example, the action indication may be configured for the wireless device to perform an RRC state transition to an RRC idle state, an RRC state transition to an RRC connected state, an RNA update procedure, and / or a random access procedure. In one example, a second base station that receives the first core network paging message may determine whether there is a direct interface (e.g., an Xn interface) between the first base station and the second base station based at least on the base station identifier of the first base station.

[0441] In one example, the second base station receiving the first core network paging message may broadcast / multicast a second core network paging message including a wireless device identifier such as a recovery ID, an S-TMSI, or an IMSI. In one example, the second core network paging message may further include an AS context identifier, an RNA identifier, a reason for the core network paging, and / or an action indication for the wireless device. The second core network paging message may be configured to initiate a random access procedure by the wireless device. In one example, the wireless device may identify the second core network paging message based on at least one of the wireless device identifier, the AS context identifier, and / or the RNA identifier. In one example, after receiving the second core network paging message, the wireless device may initiate a random access procedure by transmitting a preamble message to the second base station. In one example, the random access procedure may be a level 2 random access procedure and / or a level 4 random access procedure. In one example, during the random access procedure, the second base station may inform the wireless device of an action to be taken based at least on an action indication for the wireless device, wherein the action may be at least one of transitioning the RRC state to an RRC connected state, transitioning the RRC state to an RRC idle state, remaining in an RRC inactive state, and / or initiating an RNA update procedure.

[0442] In one example, after receiving a preamble message for random access from a wireless device, the second base station may transmit a core network paging confirmation message for a first core network paging message to a core network entity. The core network paging confirmation message may include a wireless device context request for the wireless device. In one example, the core network entity may transmit a confirmation message for a first message received from a first base station to the first base station. The confirmation message to the first base station may include a wireless device context request for the wireless device. In one example, after receiving a preamble message for random access from a wireless device, the second base station may transmit a wireless device context request message to the first base station via a direct interface (e.g., an Xn interface) between the first base station and the second base station based at least on a base station identifier of the first base station included in the first core network paging message. In one example, the first base station may transmit the wireless device context to the second base station indirectly via the core network entity and / or directly via a direct interface. In one example, after transmitting the wireless device context to the second base station, the first base station may release the wireless device context (UE context).

[0443] In one example, where the second base station extracts the wireless device context from the first base station via a direct interface, the second base station may transmit a path switch request for the wireless device to the core network entity, and the core network entity may update one or more carried downlink tunnel endpoint identifiers established between the user plane core network entity and the RAN node for the wireless device, such as changing the downlink tunnel endpoint identifier from the address of the first base station to the address of the second base station.

[0444] In one example, after a successful core network paging procedure, the wireless device may remain in an RRC inactive state, transition to an RRC connected state, and / or transition to an RRC idle state. In the event that the wireless device remains in the RRC inactive state or transitions to the RRC connected state, the second base station may maintain the wireless device context of the wireless device and may maintain one or more bearers for the wireless device between the second base station and the user plane core network entity. If the wireless device remains in the RRC inactive state, the second base station may become an anchor base station for the wireless device. If the wireless device transitions to the RRC connected state, the second base station may initiate an RRC state transition of the wireless device to the RRC inactive state, and the second base station may become an anchor base station. In the event that the wireless device transitions to the RRC idle state, the second base station may not request the wireless device context to the first base station and / or to the core network entity.

[0445] In one example, if the wireless device in the RRC inactive state does not perform the RNA update procedure before the UE RNA update timer (periodic RAN notification area update timer value) expires, the wireless device may determine that the periodic RNA update has failed. The UE may start the RNA update timer in response to the RRC message configuring the periodic RNA timer in the UE and the UE transitioning to the inactive RRC state. The UE may restart the UE RNA timer when the UE transmits the RNA update.

[0446] In one example, if a periodic RNA update failure occurs, the wireless device may immediately transition its RRC state to the RRC idle state after another timer expires and / or after the number of failures in performing the RNA update procedure exceeds the periodic RNA update counter. For example, when the UE RNA update procedure is unsuccessful for a first (e.g., consecutive) number of times, the UE may determine that the periodic RNA update has failed. In one example, the base station may transmit a configuration message including the periodic RNA update timer and / or counter value to the wireless device.

[0447] In one example, the first base station may determine that the periodic RNA fails for the wireless device based on one or more criteria including expiration of a periodic RAN notification area update timer. The first base station may transmit a first message to a core network entity in response to determining that the periodic RNA fails, wherein the first message may include a first wireless device identifier of the wireless device, and / or the first message may indicate that the periodic RNA fails for the wireless device. The first message may further include a first indication indicating that the first base station releases the wireless device context. The first base station may further release the wireless device context of the wireless device. The first message may further include a second indication indicating that a first duration associated with the RNA update period has passed and no RNA update has been received. The second base station may further receive a second message including the first page and the second wireless device identifier of the wireless device from the core network entity. The second base station may broadcast and / or multicast a third message including the second page and the second wireless device identifier. The second base station may receive a fourth message including a confirmation of the second page from the wireless device, wherein the wireless device may recognize the second paging request based at least on the second wireless device identifier. The second base station may transmit a fifth message indicating a response to the second message to the core network entity.

[0448] In one example, the first base station may further receive a fifth message including a request for a wireless device context for the wireless device. The first base station may transmit a sixth message including the wireless device context. The first base station may release the wireless device context. The wireless device may further transition the radio resource control state to the radio resource control idle state in response to the paging message from the base station. The wireless device may further transition the radio resource control state to the radio resource control idle state after receiving the paging message. The wireless device may be in a radio resource control RRC inactive state after receiving the paging message. The second base station may further transmit to the wireless device at least one of the following: a message including a radio resource control state transition indication of completing the radio resource control state transition from the radio resource control connected state to the radio resource control inactive state, a message including a radio access network notification area update acceptance, and / or one of one or more packets. The second base station may receive from the wireless device at least one of the following: a message including a radio access network notification area update request, one of the one or more packets received by the first base station from the wireless device, and / or a message including a confirmation of the radio access network notification area paging.

[0449] In one example, the first base station may further release the RAN context of the wireless device. The first base station and / or the core network entity may cause the radio resource control state to transition from the RRC inactive state to the RRC idle state. In one example, if the second criterion is met, the wireless device may transition from the RRC inactive state to the RRC idle state. The first base station may transmit one or more messages including one or more configuration parameters of the RNA to the wireless device, the one or more configuration parameters including a parameter indicating a value for a periodic RAN notification area update timer value. In one example, the first base station may transmit one or more criteria including reaching a periodic RAN notification area update counter to the wireless device. If the number of failures of the RNA update reaches the periodic RAN notification area update counter, the wireless device may transition to the RRC idle state.

[0450] In an example, the wireless device may receive one or more first messages including one or more configuration parameters for RNA from a base station, the one or more configuration parameters including a parameter indicating a value for a periodic RAN notification area update timer value. The wireless device may determine that the periodic RNA update has failed based on one or more criteria including expiration of the periodic RAN notification area update timer. The wireless device may transition to an RRC idle state in response to determining that the periodic RNA update has failed.

[0451] Embodiments may be configured as desired. The disclosed mechanisms may be performed, for example, in a wireless device, a base station, a radio environment, a network, a combination of the above, etc., 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 settings, packet size, traffic characteristics, a combination of the above, etc. When the one or more criteria are met, various example embodiments may be applied. Thus, it is possible to implement example embodiments that selectively implement the disclosed protocol.

[0452] According to various embodiments, a device (e.g., a wireless device, an off-grid wireless device, a base station, etc.) may include one or more processors and a memory. The memory may store instructions that, when executed by the one or more processors, cause the device to perform a series of actions. Examples of examples of actions are shown in the drawings and the specification. Features from various embodiments may be combined to create additional embodiments.

[0453] Fig. 27 is an example flow chart according to aspects of an embodiment of the present disclosure. At 2710, a first base station may receive one or more packets for a wireless device in a radio resource control (RRC) inactive state from a first core network entity. At 2720, the first base station may initiate a radio access network (RAN) paging procedure, including sending at least one RAN paging message to at least one second base station. The at least one RAN paging message may include a first identifier of the wireless device. At 2730, the first base station may determine a failure of the RAN paging procedure in response to not receiving a response to the at least one RAN paging message. At 2740, the first base station may send a first message to a second core network entity in response to the failure of the RAN paging procedure. At 2750, the first base station may receive a second message from the second core network entity in response to the first message. The second message may include a tunnel endpoint identifier of a third base station for forwarding the one or more packets. At 2760, the first base station may send the one or more packets to the third base station based on the tunnel endpoint identifier.

[0454] According to an embodiment, the second core network entity may initiate a core network paging procedure in response to receiving the first message. The core network paging procedure may include sending the first paging message to the third base station. The first paging message may include a second identifier of the wireless device. The second core network entity may receive a third message from the third base station in response to the first paging message. The third message may include a tunnel endpoint identifier of the third base station. According to an embodiment, the first core network entity may include a control plane core network node. The second core network entity may include a user plane core network node. According to an embodiment, the sending of the one or more packets may be via a direct tunnel between the first base station and the third base station. The direct tunnel may be associated with a tunnel endpoint identifier. According to an embodiment, the tunnel endpoint identifier may include an Internet Protocol (IP) address of the third base station. According to an embodiment, the first message may indicate a failure of the RAN paging procedure. According to an embodiment, the at least one RAN paging message may include at least one of the following: RAN notification information; a context identifier of the wireless device; a reason for initiating the RAN paging procedure; and the like. According to an embodiment, the at least one second base station may transmit a second RAN paging message via a radio interface in response to receiving the at least one RAN paging message.

[0455] Fig.28 is an example flow chart according to aspects of an embodiment of the present disclosure. At 2810, a third base station may receive a first paging message for a wireless device from a second core network entity. The first paging message may include a second identifier of the wireless device. At 2820, the third base station may transmit a second paging message for the wireless device via a radio interface in response to receiving the first paging message. At 2830, the third base station may receive a random access preamble for a radio resource control (RRC) connection from the wireless device in response to the first paging message. At 2840, the third base station may transmit a third message including a tunnel endpoint identifier of the third base station to the second core network entity in response to the RRC connection. At 2850, the third base station may receive one or more packets from the first base station based on the tunnel endpoint identifier.

[0456] According to an embodiment, the second core network entity may include a user plane core network node. According to an embodiment, the receiving of the one or more packets may be via a direct tunnel between the first base station and the third base station. The direct tunnel may be associated with a tunnel endpoint identifier. According to an embodiment, the tunnel endpoint identifier may include an Internet Protocol (IP) address of the third base station.

[0457] Fig.29is an example flow chart according to aspects of an embodiment of the present disclosure. At 2910, a first base station may receive one or more packets for a wireless device from a first core network entity. At 2920, the first base station may initiate a paging procedure. The paging procedure may include sending at least one paging message to at least one second base station. The at least one paging message may include a first identifier of the wireless device. At 2930, the first base station may send the first message to the second core network entity in response to determining a failure of the paging procedure. At 2940, the first base station may receive a second message from the second core network entity in response to the first message. The second message may include a tunnel identifier of a third base station for forwarding the one or more packets. At 2950, ​​the first base station may send the one or more packets to the third base station based on the tunnel identifier.

[0458] According to an embodiment, the paging procedure may include a radio access network (RAN) paging procedure. According to an embodiment, the tunnel identifier may include a tunnel endpoint identifier. According to an embodiment, the wireless device may be in a radio resource control inactive state. According to an embodiment, determining the failure may be in response to not receiving a response to the at least one paging message. According to an embodiment, the first message may indicate a failure of the paging procedure.

[0459] Fig.30 is an example flow chart according to aspects of an embodiment of the present disclosure. At 3010, a first base station may transmit a first message including a first radio access network (RAN) area identifier of the first base station to a second base station. At 3020, the first base station may receive a second message including a second RAN area identifier of the second base station from the second base station. At 3030, the first base station may transmit at least one radio resource control (RRC) message to the wireless device. The at least one RRC message may include a first RAN area identifier. The at least one RRC message may indicate a state transition of the wireless device to an RRC inactive state. At 3040, the first base station may receive one or more packets for the wireless device. At 3050, when the first RAN area identifier is equal to the second RAN area identifier, the first base station may transmit a RAN paging message to the second base station and in response to receiving the one or more packets. The RAN paging message may include an identifier of the wireless device and the first RAN area identifier.

[0460] According to an embodiment, the first message may further include a first cell identifier of a first cell of the first base station. The first cell may be associated with a first RAN area identifier. According to an embodiment, the second message may further include a second cell identifier of a second cell of the second base station. The second cell may be associated with a second RAN area identifier. According to an embodiment, the transmission of the RAN paging message may be in response to the wireless device being in an RRC inactive state. According to an embodiment, the first base station may further receive a third message from the second base station in response to the RAN paging message. According to an embodiment, the first base station may further transmit the one or more packets for the wireless device to the second base station in response to the third message. According to an embodiment, the first base station may maintain a wireless device context of the wireless device at least during the time when the wireless device is in the RRC inactive state. The wireless device context may include at least one of the following: bearer configuration information; logical channel configuration information; security information; and the like. According to an embodiment, the first message may include at least one of the following: an interface setup request message; an interface setup response message; a base station configuration update message; and the like. According to an embodiment, the first base station may receive the one or more packets from a core network entity. According to an embodiment, the first base station may further transmit one or more RAN paging messages to one or more third base stations associated with the first RAN identifier.

[0461] Fig.31 is an example flow chart according to aspects of an embodiment of the present disclosure. At 3110, the second base station may receive a first message including a first radio access network (RAN) area identifier of the first base station from the first base station. At 3120, the second base station may transmit a second message including a second RAN area identifier of the second base station to the first base station. At 3130, when the first RAN area identifier is equal to the second RAN area identifier, the second base station may receive a RAN paging message for the wireless device from the first base station. The wireless device may: be in a radio resource control (RRC) inactive state; and be assigned a first RAN area identifier. According to an embodiment, the RAN paging message may include an identifier of the wireless device and the first RAN area identifier.

[0462] Fig.32is an example flow chart according to aspects of an embodiment of the present disclosure. At 3210, a first base station may receive a second message including a second radio access network (RAN) area identifier of the second base station from a second base station. At 3220, the first base station may transmit at least one third message including the first RAN area identifier to the wireless device. The at least one third message may indicate a state transition of the wireless device to a radio resource control inactive state. At 3230, the first base station may receive one or more packets for the wireless device. At 3240, when the first RAN area identifier is equal to the second RAN area identifier, the first base station may transmit a RAN paging message to the second base station and in response to receiving the one or more packets. The RAN paging message may include an identifier of the wireless device and the first RAN area identifier. According to an embodiment, the first base station may further transmit a first message including the first RAN area identifier of the first base station to the second base station.

[0463] Fig.33 is an example flow chart according to aspects of an embodiment of the present disclosure. At 3310, a first base station may receive at least one first packet associated with a wireless device from a second base station. At 3320, when the wireless device is in a radio resource control (RRC) inactive state, the first base station may receive at least one second packet for the wireless device from a core network entity. At 3330, the first base station may transmit a first RAN paging message to a third base station of a radio access network (RAN) area associated with the wireless device and in response to a first duration being greater than a first time value. The first duration may include a duration between the reception of the at least one first packet and the reception of the at least one second packet. At 3340, the first base station may transmit a second RAN paging message to the second base station, regardless of whether the first duration is less than or greater than the first time value. At 3350, the first base station may transmit at least one second packet to one of the second base station or the third base station based on a received response to one of the first RAN paging message or the second RAN paging message.

[0464] According to an embodiment, the RAN area may be associated with a RAN notification area. According to an embodiment, the first RAN paging message or the second RAN paging message may include: an identifier of the wireless device; and RAN area information of the RAN area. According to an embodiment, the at least one first packet may be associated with at least one of: uplink data transmission of the wireless device in the RRC inactive state; data transmission; RAN notification area update procedure; or a state transition of the wireless device from the RRC inactive state connected state to the RRC inactive state. According to an embodiment, the first time value may be based on the moving speed of the wireless device. According to an embodiment, the first base station may maintain the wireless device context of the wireless device at least during the time when the wireless device is in the RRC inactive state. The wireless device context may include at least one of the following: bearer configuration information; logical channel configuration information; packet data convergence protocol configuration information; or security information. According to an embodiment, the first base station may be associated with the RAN area. According to an embodiment, the first base station may further transmit at least one RRC message including the RAN area information of the RAN area to the wireless device. The at least one RRC message may indicate the state transition of the wireless device to the RRC inactive state.

[0465] According to an embodiment, the second base station may transmit a first paging message via a first cell of a RAN area associated with the wireless device in response to: receiving a second RAN paging message; and the second duration is greater than a second time value. The second duration may include a duration between receiving the at least one first packet from the wireless device and receiving the second RAN paging message. The second base station may transmit the second paging message via a second cell, regardless of whether the second duration is less than or greater than the second time value, wherein the second base station may have received the at least one first packet from the wireless device by the second cell. According to an embodiment, the second base station may further transmit the at least one second packet via one of the first cell or the second cell based on a received response to one of the first paging message or the second paging message.

[0466] Fig.34is an example flow chart according to aspects of an embodiment of the present disclosure. At 3410, a first base station may receive at least one first packet associated with a wireless device from a second base station. At 3420, when the wireless device is in a radio resource control (RRC) inactive state, the first base station may receive at least one second packet for the wireless device from a core network entity. At 3430, the first base station may determine whether a duration between the reception of the at least one first packet and the reception of the at least one second packet is greater than a first time value. When the duration is greater than the first time value (3440), the first base station may transmit a first RAN paging message to a third base station of a radio access network (RAN) area associated with the wireless device at 3445. When the duration is less than or equal to the first time value (3450), the first base station may transmit a second RAN paging message to the second base station at 3455. At 3460, the first base station may transmit at least one second packet to one of the second base station or the third base station based on a received response to one of the first RAN paging message or the second RAN paging message.

[0467] Fig.35 is an example flow chart according to aspects of an embodiment of the present disclosure. At 3510, a first base station may receive at least one first packet from a wireless device via a first cell of the first base station. At 3520, when the wireless device is in a radio resource control inactive state, the first base station may receive at least one second packet for the wireless device from a core network entity. At 3530, the first base station may transmit a first RAN paging message to a second base station of a radio access network (RAN) area associated with the wireless device and in response to a first duration being greater than a first time value. The first duration may include a duration between the reception of the at least one first packet and the reception of the at least one second packet. At 3540, the first base station may transmit a second RAN paging message via one or more second cells of the RAN area, regardless of whether the first duration is less than or greater than the first time value. The one or more second cells may include the first cell. At 3550, the first base station may transmit the at least one second packet to the wireless device via one or more second cells or one of the second base stations based on a received response to one of the first RAN paging message or the second RAN paging message.

[0468] Fig.36is an example flow chart according to aspects of an embodiment of the present disclosure. At 3610, the wireless device may receive at least one first message including configuration parameters of at least one of the following from a base station: at least one logical channel; or at least one radio bearer. At 3620, the wireless device may receive a second message from the base station indicating a radio resource control (RRC) state transition of the wireless device from an RRC connected state to an RRC inactive state. At 3630, the wireless device in the RRC inactive state may select a first cell based on the configuration parameters. At 3640, the wireless device may transmit a random access preamble to the base station via the first cell.

[0469] According to an embodiment, the configuration parameter may further include at least one of the following: a first cell identifier of the first cell; at least one logical channel identifier of the at least one logical channel; or at least one radio bearer identifier of the at least one radio bearer. According to an embodiment, the configuration parameter may indicate an association of the at least one logical channel or the at least one radio bearer with the first cell. According to an embodiment, the configuration parameter may indicate an association of the at least one logical channel or the at least one radio bearer with at least one of the following: one or more cell types; or one or more frequency bands. According to an embodiment, the configuration parameter may further indicate an association of the first network slice with at least one of the following: the first cell; one or more cell types; or one or more frequency bands. According to an embodiment, the at least one logical channel or the at least one radio bearer may be associated with the first network slice. According to an embodiment, the base station may maintain a wireless device context of the wireless device at least during the time when the wireless device is in an RRC inactive state. The wireless device context may include at least one of the following: bearer configuration information; logical channel configuration information; packet data convergence protocol configuration information; security information; and the like. According to an embodiment, the selection of the first cell may be responsive to the uplink buffer including one or more packets associated with at least one of the following: the at least one logical channel; or the at least one radio bearer. According to an embodiment, the transmission of the random access preamble message may be responsive to at least one of: an uplink buffer including one or more packets; a paging indication from a base station; moving to a first radio access network notification area; or moving to a first tracking area.

[0470] Fig.37is an example flow chart according to aspects of an embodiment of the present disclosure. At 3710, a base station may transmit at least one first message to a wireless device. The at least one first message may include configuration parameters of at least one of the following: at least one logical channel; or at least one radio bearer. At 3720, the base station may transmit a second message to the wireless device indicating a radio resource control (RRC) state transition of the wireless device from an RRC connected state to an RRC inactive state. At 3730, the base station may receive a random access preamble from the wireless device via a first cell selected by the wireless device based on the configuration parameters. The wireless device may be in an RRC inactive state. According to an embodiment, the configuration parameters may further include at least one of the following: a first cell identifier of the first cell; at least one logical channel identifier of the at least one logical channel; or at least one radio bearer identifier of the at least one radio bearer.

[0471] Fig.38 is an example flow chart according to aspects of an embodiment of the present disclosure. At 3810, a first base station may transmit at least one first message to a wireless device indicating a radio resource control (RRC) state transition of the wireless device from an RRC connected state to an RRC inactive state. The at least one first message may include a parameter indicating a value associated with a wireless device RAN notification area update timer for a periodic radio access network (RAN) notification area update procedure. At 3820, the first base station may receive a second message indicating a RAN notification area update performed by the wireless device in response to expiration of the wireless device RAN notification area update timer. At 3830, the first base station may start a network RAN ​​notification area update timer in response to receiving the second message. At 3840, the first base station may transmit a third message indicating a wireless device context release request for the wireless device to a core network entity and in response to expiration of the network RAN ​​notification area update timer. The third message may include an identifier of the wireless device.

[0472] According to an embodiment, the at least one first message may further include RAN notification area information associated with the wireless device. The RAN notification area information may include at least one of the following: a RAN area identifier; or a cell identifier. According to an embodiment, the first base station may further release the wireless device context of the wireless device based on the expiration of the network RAN ​​notification area update timer. According to an embodiment, the third message may further indicate that the wireless device failed in the periodic RAN notification area update. According to an embodiment, the core network entity may determine that the wireless device is in an idle state in response to receiving the third message. According to an embodiment, the first base station may maintain the wireless device context of the wireless device at least during the time when the wireless device is in the RRC inactive state. The wireless device context may include at least one of the following: bearer configuration information; logical channel configuration information; packet data convergence protocol configuration information; security information, etc. According to an embodiment, the wireless device RAN notification area update timer may be configured based on at least one of the following: a moving speed of the wireless device; a wireless device type of the wireless device; a network slice of the wireless device; a bearer of the wireless device; etc. According to an embodiment, the core network entity may further transmit a paging message for the wireless device to the second base station based on the third message. The core network entity may further receive a response message to the paging message from the second base station. According to an embodiment, the wireless device may transition the RRC state from the RRC inactive state to the RRC idle state in response to the periodic RAN notification area update failure. According to an embodiment, the second message may include an RRC connection recovery request message.

[0473] Fig.39 is an example flow chart according to aspects of an embodiment of the present disclosure. At 3910, the first base station may transmit to the wireless device at least one first message indicating a radio resource control (RRC) state transition of the wireless device from an RRC connected state to an RRC inactive state. At 3920, the first base station may receive from the wireless device a second message indicating a RAN notification area update performed by the wireless device. At 3930, the first base station may start a network radio access network (RAN) notification area update timer in response to receiving the second message. At 3940, the first base station may transmit to the core network entity and in response to the expiration of the network RAN ​​notification area update timer a third message indicating a wireless device context release request for the wireless device. The third message may include an identifier of the wireless device.

[0474] Fig.40is an example flow chart according to aspects of an embodiment of the present disclosure. At 4010, a first base station may transmit at least one first message to a wireless device indicating a radio resource control (RRC) state transition of the wireless device from an RRC connected state to an RRC inactive state. The at least one first message may include a parameter indicating a value associated with a wireless device RAN notification area update timer for a periodic radio access network (RAN) notification area update procedure. At 4020, the first base station may receive a second message indicating a RAN notification area update performed by the wireless device in response to the expiration of the wireless device RAN notification area update timer. At 4030, the first base station may transmit a third message indicating a wireless device context release request for the wireless device to a core network entity and in response to not receiving a RAN notification area update within a certain duration. The time period may be longer than the value associated with the wireless device RAN notification area update timer. According to an embodiment, the third message may include an identifier of the wireless device.

[0475] Fig.41 is an example flow chart according to aspects of embodiments of the present disclosure. At 4110, a first base station may transmit to a wireless device at least one first message indicating a radio resource control (RRC) state transition of the wireless device from an RRC connected state to an RRC inactive state. The at least one first message may include a parameter indicating a first value associated with a wireless device RAN notification area update timer for a periodic radio access network (RAN) notification area update procedure. At 4120, the wireless device may start the RAN notification area update timer in response to the RRC state transition. At 4130, the first base station may receive a second message indicating a RAN notification area update performed by the wireless device with a second value in response to the expiration of the wireless device RAN notification area update timer. At 4140, the first base station may start a network RAN ​​notification area update timer in response to receiving the second message. At 4140, the first base station may transmit to a core network entity and in response to the expiration of the network RAN ​​notification area update timer a third message indicating a wireless device context release request for the wireless device. The third message may include an identifier of the wireless device. The second value of the network RAN ​​notification area update timer may be greater than the first value of the wireless device RAN notification area update timer.

[0476] A base station may communicate with a mixture of wireless devices. A wireless device and / or a base station may support multiple technologies, and / or multiple versions of the same technology. A wireless device may have certain specific capabilities, depending on the wireless device category and / or capabilities. A base station may include multiple sectors. When the present disclosure refers to a base station that communicates with multiple wireless devices, the present disclosure may refer to a subset of the total wireless devices in the coverage area. For example, the present disclosure may refer to multiple wireless devices of a given LTE or 5G version with a given capability and in a given sector of a base station. The multiple wireless devices in the present disclosure may refer to a selected plurality of wireless devices and / or a subset of the total wireless devices in the coverage area executed according to the disclosed method, and so on. There may be multiple base stations or multiple wireless devices in the coverage area that may not comply with the disclosed method, for example, because those wireless devices or base stations are executed based on older versions of LTE or 5G technology.

[0477] In the present disclosure, "a" and similar phrases should be understood as "at least one" and "one or more". Similarly, any term ending with the suffix "(s)" should be understood as "at least one" and "one or more". In the present disclosure, for example, the term "may" should be understood as "may". 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 for one or more of the various embodiments.

[0478] If A and B are sets and each element in A is also an element of B, then A is called a subset of B. In this specification, only non-empty sets and subsets are considered. For example, the possible subsets of B = {cell1, cell2} are: {cell1}, {cell2}, and {cell1, cell2}. The phrase "based on" (or equivalently "at least based on") indicates that the phrase after the term "based on" is an example of one of multiple suitable possibilities that may or may not be used in one or more of the various embodiments. The phrase "in response to" (or equivalently "at least in response to") indicates that the phrase after the phrase "in response to" is an example of one of multiple suitable possibilities that may or may not be used in one or more of the various embodiments. The phrase "depends on" (or equivalently "at least depends on") indicates that the phrase after the phrase "depends on" is an example of one of multiple suitable possibilities that may or may not be used in one or more of the various embodiments. The phrase "employing / using" (or equivalently "at least employing / using") indicates that the phrase following the phrase "employing / using" is an example of one of a variety of suitable possibilities that may or may not be employed in one or more of the various embodiments.

[0479] The term "configuration" may mean a capability of a device, whether the device is in an operational state or a non-operational state. "Configuration" may also mean a specific setting in a device that affects an operational characteristic of the device, whether the device is in an operational state or a non-operational state. In other words, hardware, software, firmware, registers, memory values, etc. may be "configured" within a device, whether the device is in an operational state or a non-operational state, to provide a specific characteristic to the device. Terms such as "a control message to cause in a device" may mean that a control message has parameters that may be used to configure a specific characteristic, or may be used to implement certain actions in a device, whether the device is in an operational state or a non-operational state.

[0480] In the present disclosure, various embodiments are disclosed. Limitations, features and / or elements from the disclosed example embodiments may be combined to create additional embodiments within the scope of the present disclosure.

[0481] In the present disclosure, a parameter (or equivalently referred to as a field or information element: IE) may include one or more information objects, and an information object may include one or more other objects. For example, if parameter (IE) N includes parameter (IE) M, and parameter (IE) M includes parameter (IE) K, and parameter (IE) K includes parameter (information element) J. Then, for example, N includes K, and N includes J. In an example embodiment, when one or more messages include multiple parameters, it means that a parameter of the multiple parameters is in at least one of the one or more messages, but not necessarily in each of the one or more messages.

[0482] In addition, many of the features set forth above are described as optional through the use of "may" or the use of parentheses. For the sake of brevity and readability, the present disclosure does not explicitly recite every permutation that can be obtained by selecting from the set of optional features. However, the present disclosure should be interpreted as explicitly disclosing all such permutations. For example, a system described as having three optional features can be embodied in seven different ways, namely, having only one of the three possible features, having any two of the three possible features, or having all three of the three possible features.

[0483] Many elements described in the disclosed embodiments can be implemented as modules. Modules are defined herein as elements that perform defined functions and have defined interfaces to other elements. The modules described in the present disclosure can be implemented in hardware, software combined with hardware, firmware, wetware (i.e., hardware with biological elements) or combinations thereof, all of which are behaviorally equivalent. For example, a module can be implemented as a software routine written in a computer language, which is configured to be executed by a hardware machine (e.g., C, C++, Fortran, Java, Basic, Matlab, etc.) or modeling / simulation programs such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript. In addition, it is possible to implement a module using physical hardware including 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, which configure connections between internal hardware modules with less functionality on programmable devices. The above techniques are often used in combination to achieve the effect of functional modules.

[0484] The disclosure of this patent document incorporates material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent files or records for the limited purpose required by law, but otherwise reserves all copyright rights whatsoever.

[0485] Although various embodiments have been described above, it should be understood that they are presented by way of example and not limitation. It will be apparent to those skilled in the relevant art that various changes in form and detail may be made therein without departing from the scope of the present invention. Indeed, after reading the above description, it will be apparent to those skilled in the relevant art how to implement alternative embodiments. Therefore, the present embodiments should not be limited by any of the exemplary embodiments described above.

[0486] In addition, it should be understood that any diagrams highlighting functionality and advantages are provided for exemplary purposes only. The disclosed architecture is flexible and configurable enough that it can be utilized in a manner different from that shown. For example, the actions listed in any flow chart may be reordered or only optionally used in certain embodiments.

[0487] In addition, the purpose of the abstract is to generally enable the USPTO and the public, especially scientists, engineers, and practitioners in the field who are not familiar with patent or legal terms or phraseology, to quickly determine the nature and substance of the technical disclosure of the application through a cursory review. The abstract is not intended to limit the scope of the invention in any way.

[0488] Finally, it is Applicant's intent that only claims containing the express language "means for" or "step for" be interpreted under 35 USC 112. Claims that do not expressly contain the phrase "means for" or "step for" should not be interpreted under 35 USC 112.

Claims

1. A method performed by a base station in a wireless communication system, the method include: sending a first message to the wireless device, the first message indicating an RRC state transition of the wireless device from a Radio Resource Control (RRC) connected state to an RRC inactive state, wherein the first message includes a parameter indicating a value associated with a wireless device Radio Access Network Notification Area Update (RAN) timer for a periodic Radio Access Network (RAN) Notification Area (RNA) update procedure; In response to expiration of a wireless device RNA update timer, receiving a second message for periodic RNA update from the wireless device, and starting a network RNA update timer that is longer than the wireless device RNA update timer; determining that the periodic RNA update process is unsuccessful without receiving a second message for periodic RNA update from the wireless device based on expiration of a network RNA update timer; as well as Based on the determination, a third message indicating a wireless device context release request for the wireless device is sent to an access and mobility management function (AMF), wherein the third message includes an identifier of the wireless device and cause information as a reason for the wireless device context release request, and the cause information indicates that the wireless device in the RRC inactive state is unreachable.

2. The method of claim 1, wherein the first message further comprises RNA information associated with the wireless device, the RNA information comprising at least one of the following: RAN region identifier; and Cell identifier.

3. The method of claim 1 , further comprising releasing, by the base station, the wireless device context of the wireless device based on expiration of a network RNA update timer.

4. The method as recited in claim 1, wherein the third message further indicates that the wireless device has failed in a periodic RNA update process.

5. The method of claim 1 , wherein in response to receiving the third message, the AMF determines that the wireless device is in an idle state.

6. The method of claim 1 , wherein the base station maintains a wireless device context of the wireless device at least during a time when the wireless device is in an RRC inactive state, the wireless device context comprising at least one of: Carrying configuration information; Logical channel configuration information; Packet Data Convergence Protocol configuration information; and Safety Information.

7. The method of claim 1 , wherein the value associated with the timer is updated with the wireless device RNA based on at least one of the following configurations: a moving speed of the wireless device; The wireless device type of the wireless device: A network slice of the wireless device; and Carrying of the wireless device.

8. The method of claim 1, wherein the wireless device transitions the RRC state from the RRC inactive state to the RRC idle state based on a failure in the periodic RNA update process.

9. A base station in a wireless communication system, the base station comprising Transceiver; Communication interface; and Processor, configured as: sending, via the transceiver, a first message to the wireless device, the first message indicating an RRC state transition of the wireless device from a radio resource control, RRC connected, state to an RRC inactive state, wherein the first message includes a parameter indicating a value associated with a wireless device radio access network notification area update timer for periodic radio access network notification area RNA updates; In response to expiration of a wireless device RNA update timer, receiving a second message for periodic RNA update from the wireless device via the transceiver, and starting a network RNA update timer that is longer than the wireless device RNA update timer; determining that the periodic RNA update process is unsuccessful without receiving a second message for periodic RNA update from the wireless device based on expiration of a network RNA update timer; as well as Based on the determination, a third message indicating a wireless device context release request for the wireless device is sent to an access and mobility management function (AMF) via a communication interface, wherein the third message includes an identifier of the wireless device and cause information as a reason for the wireless device context release request, and the cause information indicates that the wireless device in the RRC inactive state is unreachable.

10. The base station as claimed in claim 9, wherein the first message further includes RNA information associated with the wireless device, the RNA information including at least one of the following: RAN region identifier; or Cell identifier.

11. The base station of claim 9, wherein the processor is further configured to release the wireless device context of the wireless device based on expiration of a network RNA update timer.

12. The base station as claimed in claim 9, wherein the third message further indicates that the wireless device has failed in a periodic RNA update process.

13. The base station as claimed in claim 9, wherein in response to receiving the third message, the AMF determines that the wireless device is in an idle state.

14. The base station of claim 9, wherein the processor is further configured to maintain a wireless device context of the wireless device at least during a time when the wireless device is in an RRC inactive state, the wireless device context comprising at least one of: Carrying configuration information; Logical channel configuration information; Packet Data Convergence Protocol configuration information; and Safety Information.

15. The base station of claim 9, wherein the value associated with the timer is updated with the wireless device RNA based on at least one of the following configurations: a moving speed of the wireless device; The wireless device type of the wireless device: A network slice of the wireless device; and Carrying of the wireless device.

16. The base station as claimed in claim 9, wherein based on the failure in the periodic RNA update, the wireless device changes the RRC state from the RRC inactive state to the RRC idle state.

Images