Method and apparatus for wireless communication

Abstract

The embodiment of the invention relates to a method and equipment for wireless communication. In accordance with some embodiments of the present disclosure, a method may include receiving, at a user equipment (UE), configuration information indicating a timer associated with fast primary cell group (MCG) link recovery; transmitting an MCG failure information message in response to detecting a radio link failure on the MCG; and starting the timer associated with fast MCG link recovery. Configured authorized sidelink resources of a first type can be used while the timer is running. When the timer is running, the UE assistance information and sidelink UE information can be allowed. In addition, the sidelink configuration can be included in an RRC reconfiguration message for conditional handover commands.

Description

[0001] Information about divisional applications

[0002] This case is a divisional application. The parent case of this divisional application is an invention patent application with application date of May 19, 2020, application number 202080100973.6., and invention name “Method and device for wireless communication”. Technical Field

[0003] Embodiments of the present application generally relate to wireless communication technology, and more particularly to fault information reporting and conditional handover (CHO) in a wireless communication system. Background Art

[0004] Wireless communication systems are widely used to provide various telecommunication services, such as telephony, video, data, messaging, broadcast, etc. Wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of wireless communication systems may include fourth generation (4G) systems, such as long term evolution (LTE) systems, advanced LTE (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems, which may also be referred to as new radio (NR) systems.

[0005] In the above wireless communication system, a user equipment (UE) can communicate with another UE via a data path supported by an operator network (eg, a cellular or Wi-Fi network infrastructure). The data path supported by the operator network may include a base station (BS) and multiple gateways.

[0006] Some wireless communication systems may support sidelink (SL) communications, where devices (e.g., UEs) that are relatively close to each other may communicate directly with each other via the SL, rather than being linked through a BS. The term "SL" may refer to a direct radio link established to communicate between devices rather than communicating via a cellular infrastructure (uplink and downlink) as discussed above. The term "SL" may also be referred to as a sidelink communication link.

[0007] In addition, in the third generation partnership project (3GPP) release 16, multi-radio dual connectivity (MR-DC) operation is supported. In MR-DC, the UE can be connected to a master node (MN) and a secondary node (SN). When a radio link failure (RLF) occurs at the UE, such as between the UE and the MN or between the UE and the SN, the UE can transmit a fault report to the network, such as a master cell group (MCG) fault report or a secondary cell group (SCG) fault report.

[0008] How to handle side link communications during the fault reporting procedure and conditional handover (CHO) procedure has not been specifically discussed in 3GPP 5G NR technology. The industry expects a technology for handling side link communications during the above procedures. Summary of the invention

[0009] According to some embodiments of the present application, a method may include: receiving configuration information indicating a timer associated with fast master cell group (MCG) link recovery at a user equipment (UE); transmitting an MCG failure information message in response to detecting a radio link failure on the MCG; and starting the timer associated with the fast MCG link recovery.

[0010] According to some other embodiments of the present application, a method may include transmitting, at a user equipment (UE), UE assistance information or a sidelink UE information message when a timer associated with a fast master cell group (MCG) link recovery is not running.

[0011] According to some other embodiments of the present application, a method may include: receiving a radio resource control (RRC) reconfiguration message including conditional RRC reconfiguration, execution conditions of conditional handover (CHO), and sidelink configuration; executing a CHO procedure when the execution conditions of CHO are met; and transmitting an RRC reconfiguration completion message in response to completion of the CHO procedure.

[0012] Some embodiments of the present application also provide an apparatus comprising: at least one non-transitory computer-readable medium having computer-executable instructions stored therein, at least one receiving circuit system; at least one transmitting circuit system; and at least one processor coupled to the at least one non-transitory computer-readable medium, the at least one receiving circuit system, and the at least one transmitting circuit system. The computer-executable instructions are programmed to implement any method as stated above with the at least one receiving circuit system, the at least one transmitting circuit system, and the at least one processor.

[0013] Embodiments of the present application provide technical solutions for handling side link communications during fault reporting procedures and conditional handover procedures, and can facilitate and improve the implementation of 5G NR technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to describe the manner in which the advantages and features of the present application can be obtained, the description of the present application is presented by reference to specific embodiments of the present application illustrated in the accompanying drawings. These drawings depict only example embodiments of the present application and therefore should not be considered to limit its scope.

[0015] Figure 1A schematic diagram illustrating a wireless communication system according to some embodiments of the present application;

[0016] Figure 2A An exemplary flow chart illustrating a fast MCG link recovery procedure according to some embodiments of the present application;

[0017] Figure 2B An exemplary timeline illustrating RLF with a fast MCG link recovery procedure according to some embodiments of the present application;

[0018] Figure 3 An exemplary flow chart illustrating a CHO procedure according to some embodiments of the present application;

[0019] Figure 4 A schematic diagram illustrating a wireless communication system according to some embodiments of the present application;

[0020] Figure 5 An exemplary procedure for providing UE assistance information according to some embodiments of the present application is described;

[0021] Figure 6 Describe an exemplary procedure for providing sidelink UE information according to some embodiments of the present application;

[0022] Figure 7 Describe an exemplary procedure for transmitting fault information according to some embodiments of the present application;

[0023] Figure 8 An exemplary flow chart illustrating a CHO procedure according to some embodiments of the present application; and

[0024] Fig. 9 A block diagram illustrating an exemplary apparatus according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0025] The detailed description of the accompanying drawings is intended as a description of the preferred embodiments of the present application, but is not intended to represent the only form in which the present application can be practiced. It should be understood that the same or equivalent functions can be implemented by different embodiments that are intended to be included in the spirit and scope of the present application.

[0026] Reference will now be made in detail to some embodiments of the present application, examples of which are illustrated in the accompanying drawings. To facilitate understanding, embodiments are provided under specific network architectures and new service scenarios (e.g., 3GPP 5G, 3GPP LTE Release 8, etc.). It can be considered that, with the development of network architectures and new service scenarios, all embodiments in the present application are also applicable to similar technical problems; and in addition, the terms listed in the present application may change, which should not affect the principles of the present application.

[0027] The next generation radio access network (NG-RAN) supports multi-radio dual connectivity (MR-DC) operation. In MR-DC operation, a UE with multiple transceivers can be configured to utilize resources provided by two different nodes connected via a non-ideal backhaul. Among them, one node can provide NR access, and the other node can provide Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA) (E-UTRA) or NR access. One node can act as a master node (MN), and the other node can act as a secondary node (SN). MN and SN are connected via a network interface (e.g., an Xn interface specified in a 3GPP standard document), and at least MN is connected to a core network.

[0028] For example, Figure 1 A schematic diagram illustrating a wireless communication system according to some embodiments of the present application.

[0029] As in Figure 1 , the wireless communication system 100 may be a dual connectivity system including at least one user equipment (UE) 101, at least one MN 102, and at least one SN 103. In particular, for illustrative purposes, Figure 1 The dual connectivity system in FIG. 1 includes one UE 101 shown, one MN 102 shown, and one SN 103 shown. Figure 1 A specific number of UEs 101, MNs 102, and SNs 103 are depicted in FIG. 1 , but it is contemplated that any number of UEs 101, MNs 102, and SNs 103 may be included in the wireless communication system 100.

[0030] refer to Figure 1 UE 101 may be connected to MN 102 and SN 103 via a network interface (e.g., a Uu interface specified in a 3GPP standard document). MN 102 and SN 103 may be connected to each other via a network interface (e.g., an Xn interface specified in a 3GPP standard document). MN 102 may be connected to MN 102 and SN 103 via a network interface (e.g., an Xn interface specified in a 3GPP standard document). Figure 1 102 is connected to the core network. In some embodiments of the present application, SN 103 may also be connected to the core network. UE 102 may be configured to utilize resources provided by MN 102 and SN 103 to perform data transmission, signaling transmission, or both.

[0031] MN 102 may refer to a radio access node that provides a control plane connection to a core network. In some embodiments of the present application, in an E-UTRA-NR DC (EN-DC) scenario, MN 102 may be an eNB. In some other embodiments of the present application, in a next generation E-UTRA-NR DC (NGEN-DC) scenario, MN 102 may be an ng-eNB. In other embodiments of the present application, in an NR-DC scenario or an NR-E-UTRA=DC (NE-DC) scenario, MN 102 may be a gNB.

[0032] A MN may be associated with a Master Cell Group (MCG). An MCG may refer to a set of serving cells associated with a MN and may include a primary cell (PCell) and optionally one or more secondary cells (SCells). A PCell may provide a control plane connection to a UE (eg, UE 101).

[0033] SN 103 may refer to a radio access node that does not have a control plane connection to the core network but provides additional resources to UE 101. In some embodiments of the present application, in an EN-DC scenario, SN 103 may be an en-gNB. In some other embodiments of the present application, in a NE-DC scenario, SN 103 may be an ng-eNB. In still other embodiments of the present application, in an NR-DC scenario or a NGEN-DC scenario, SN 103 may be a gNB.

[0034] A SN may be associated with a secondary cell group (SCG). An SCG may refer to a group of serving cells associated with a SN, and may include a primary secondary cell (PSCell) and optionally one or more secondary cells (SCells).

[0035] The PCell of MCG and the PSCell of SCG can also be called special cells (SpCell).

[0036] In some embodiments of the present application, UE 101 may include a computing device, such as a desktop computer, a laptop computer, a personal digital assistant (PDA), a tablet computer, a smart TV (e.g., a TV connected to the Internet), a set-top box, a game console, a security system (including a security camera), a vehicle onboard computer, a network device (e.g., a router, a switch and a modem) or the like. In some other embodiments of the present application, UE 101 may include a portable wireless communication device, a smart phone, a cellular phone, a flip phone, a device with a user identity module, a personal computer, a selective call receiving circuit system, or any other device capable of sending and receiving communication signals on a wireless network. In some other embodiments of the present application, UE 101 includes a wearable device, such as a smart watch, a fitness band, an optical head-mounted display or the like. In addition, UE 101 may be referred to as a user unit, a mobile device, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a user station, a user terminal or a device, or other terms used in the field are used to describe.

[0037] UE 101 may be configured to monitor the MCG of MN 102 and may detect MCG failure. In some embodiments of the present disclosure, UE 101 may initiate an MCG recovery procedure (e.g., a fast MCG link recovery procedure) to notify MN 102 of the RLF on the MCG via an SCG link (e.g., SN 103), so that the UE in the RRC_CONNECTED state may initiate a fast MCG link recovery procedure to quickly continue the RRC connection without performing a reestablishment procedure.

[0038] Figure 2A An exemplary flow chart illustrating a fast MCG link recovery procedure according to some embodiments of the present application. Figure 2A In the embodiment, UE 201 can communicate with MN (e.g., MN 202) and SN (not in Figure 2A In some examples, UE 201 can be used as Figure 1 UE 101 in, and MN 202 can be used as Figure 1 MN 102.

[0039] As in Figure 2AAs shown in , in the event that RLF occurs on the MCG of UE 201, UE 201 may initiate (or trigger) a fast MCG link recovery procedure. For example, in step 211, UE 201 may transmit an MCG failure information message to MN 202 in response to the RLF on the MCG. In some embodiments of the present application, the RLF on the MCG may refer to the RLF occurring in the PCell of the MCG. In some embodiments of the present application, the MCG failure information message associated with the RLF in step 211 may be the MCGFailureInformation message specified in the 3GPP standard document. In some embodiments of the present application, UE 201 may not transmit the MCG failure information message directly to MN 202. Instead, UE 201 may transmit the MCG failure information message associated with the RLF to the SN (for example, Figure 1 SN 103 shown in ), and then the SN can transmit the MCG failure information message received from UE 201 to MN 202.

[0040] In some embodiments of the present application, UE 201 may be configured with a separate signaling radio bearer (SRB) 1 or SRB3 to report MCG failure information when RLF occurs on the MCG. In the case of configuring a separate SRB1 (or SRB1 is configured as a separate SRB1), UE 201 may submit an MCG failure information message to a lower layer for transmission via SRB1 (i.e., separate SRB1). In the case of configuring SRB3, UE 201 may submit an MCG failure information message to a lower layer for transmission via SRB3. For example, the MCG failure information message may be encapsulated or embedded in an RRC message (e.g., the NR RRC message ULInformationTransferMRDC specified in the 3GPP standard document) for transmission via SRB3.

[0041] When or after transmitting the MCG Failure Information message in step 211, UE 201 may start a timer associated with fast MCG link recovery (hereinafter referred to as "link recovery timer"). In some embodiments of the present application, the link recovery timer may be timer T316 as specified in the 3GPP standard document.

[0042] After receiving the MCG Failure Information message, in step 213, MN 202 may determine to maintain, change, or release the faulty radio link, and may transmit a response message to UE 201. For example, in the case where MN 202 determines to change or release the faulty radio link, MN 202 may transmit an RRC reconfiguration (e.g., reconfiguration with synchronization) message or an RRC release message to UE 201. The RRC reconfiguration message may include a handover (HO) command for the cell. In some embodiments of the present application, the handover command may be a reconfigurationWithSync configuration as specified in a 3GPP standard document. MN 202 may not transmit a response message directly to UE 201. Instead, MN 202 may send a response message to SN (e.g., Figure 1 SN103) shown in transmits a response message, and then the SN can transmit a response message to UE 201.

[0043] In some embodiments of the present application, when SRB3 is configured for transmitting MCG failure information messages, after receiving a response message from MN 202, the SN may encapsulate the response message in an RRC message (for example, a DLInformationTransferMRDC message as specified in the 3GPP standard document), and then transmit the RRC message to UE 201.

[0044] In some embodiments of the present application, the MCG fault information message may indicate a fault type, which may indicate a link failure due to, for example, one of the following: (1) expiration of a physical layer problem timer; (2) a random access problem; and (3) reaching a maximum number of retransmissions.

[0045] Failure type (1) may refer to a case where the UE initiates transmission of an MCG Failure Information message (e.g., as shown in step 211) in response to expiration of a physical layer problem timer (e.g., T310 as specified in the 3GPP standard document). Failure type (2) may refer to a case where the UE initiates transmission of an MCG Failure Information message (e.g., as shown in step 211) to provide a random access problem indication from the media access control (MAC) layer of the MCG. Failure type (3) may refer to a case where the UE initiates transmission of an MCG Failure Information message (e.g., as shown in step 211) to provide an indication from the MCG Radio Link Control (RLC) that the maximum number of retransmissions has been reached.

[0046] Before the link recovery timer expires, if UE 201 receives one of the RRC reconfiguration message or the RRC release message, UE 201 should stop the link recovery timer, which means that the fast MCG link recovery procedure is terminated. In the case where UE 201 receives an RRC reconfiguration message including a handover command for a cell, the UE may perform a handover for the UE to the cell. In the case where UE 201 receives an RRC release message, the UE should enter the RRC_IDLE state. In some embodiments of the present application, before the link recovery timer expires, the UE may not receive any response message from MN 202. UE 201 may perform an RRC reestablishment procedure after the link recovery timer expires.

[0047] Figure 2B An exemplary timeline of RLF with fast MCG link recovery procedure is illustrated according to some embodiments of the present application. Figure 2B Embodiments of the present invention may be implemented by a UE (eg, Figure 1 UE 101 shown in or Figure 2A UE 201) shown in FIG.

[0048] according to Figure 2B , at the beginning, the UE may perform data transmission in the normal operation phase. At some time, when (for example) the MAC layer of the UE receives N310 continuous out-of-sync indication from the physical layer of the UE, the UE may detect a radio problem. This means that a radio link problem has occurred. The UE may start a physical layer problem timer (for example, timer T310). During the period of timer T310, when the MAC layer of the UE receives N311 continuous in-sync indication from the physical layer of the UE, this means that the UE is successfully connected to the network, and the UE may stop timer T310.

[0049] When the timer T310 expires, which means that there is no recovery during the timer T310, the UE may initiate a fast MCG link recovery procedure. For example, the UE may perform the following steps: Figure 2A , and a link recovery timer (e.g., timer T316) associated with the fast MCG link recovery procedure may be started. In the case where the UE receives an RRC reconfiguration from the MN via the SN, the UE may stop timer T316, which means that the fast MCG link recovery procedure is terminated. Otherwise, in response to the expiration of timer T316, which means that there is no recovery during timer T316, the UE may perform a reestablishment procedure and start a timer associated with the reestablishment procedure (e.g., timer T311 as specified in the 3GPP standard document).

[0050] When the timer T311 expires, which means that there is no recovery during the timer T311, the UE may enter an idle state, such as the RRC_IDLE state. Figure 2B As shown in , before expiration of timer T311, the UE is in the RRC_CONNECTED state, and the UE may enter the RRC_IDLE state in response to expiration of the timer T311.

[0051] In some embodiments of the present application, the UE may be configured with a conditional handover (CHO) procedure. The CHO procedure is defined as a handover procedure performed by the UE when one or more handover execution conditions are met. In the CHO procedure, the UE may start evaluating the execution conditions after receiving CHO configuration information, and once the execution conditions are met, stop evaluating the execution conditions during the CHO execution.

[0052] For example, Figure 3 An exemplary flow chart illustrating a CHO procedure according to some embodiments of the present application. Figure 3 , which describes a basic condition handover scenario, where the Access and Mobility Management Function (AMF) and the User Plane Function (UPF) are unchanged.

[0053] exist Figure 3 In step 300, the UE is connected to a source base station (BS), which may operate under the control of core network entities (e.g., AMF and UPF). In step 300, the AMF may provide the UE context of the UE to the source BS. The UE context may contain information about roaming and access restrictions of the UE.

[0054] In step 301, the source BS may transmit measurement configuration information to the UE. The UE may report a measurement result to the source BS based on the measurement configuration information.

[0055] In step 302, the source BS uses CHO for the UE, which may be based on the measurement results reported by the UE. In step 303, the source BS may transmit a CHO request message to one or more candidate BSs. For example, the one or more candidate BSs may include at least the target BS, and may further include other potential target BSs. In step 304, the target BS (and other potential target BSs) may perform admission control to decide whether to allow CHO of the UE after receiving the CHO request message from the source BS.

[0056] In step 305, based on the admission control result, at least one of the target BS and other potential target BSs may transmit a CHO response message to the source BS. The CHO response message may include CHO configurations of one or more candidate cells.

[0057] In step 306, the source BS may transmit an RRC reconfiguration message to the UE. The RRC reconfiguration message may include CHO configuration information indicating a set of CHO configurations for a set of cells and a set of execution conditions for the set of cells. Each cell in the set of cells may be referred to as a CHO candidate cell and is associated with a CHO configuration and an execution condition. Each CHO configuration may include a configuration of a corresponding CHO candidate cell generated by a corresponding candidate BS, and may include parameters for the UE to perform a handover to the cell. For example, a CHO configuration associated with a cell may include parameters for the UE to access the cell and / or perform data transmission with the cell.

[0058] The set of execution conditions may be generated by the source BS. The execution conditions may include one or two trigger conditions. For example, in the case where the execution conditions include one trigger condition, the trigger condition may be an A3 event or an A5 event as specified in the 3GPP standard document TS38.331. In the case where the execution conditions include two trigger conditions, the two trigger conditions may be an A3 event and an A5 event as specified in the 3GPP standard document TS38.331.

[0059] In addition, only a single reference signal (RS) type can be used to evaluate the execution condition of a single cell, and up to two different execution quantities can be configured simultaneously to evaluate the execution condition of a single cell. For example, the two different execution quantities may be reference signal received power (RSRP) and reference signal received quality (RSRQ), or RSRP and signal interference plus noise ratio (SINR) or the like. In some embodiments of the present application, more than one execution condition may be satisfied, that is, more than one cell may be suitable for handover of the UE. In this case, the UE may select a cell for performing CHO based on the execution quantity.

[0060] After receiving the RRC reconfiguration message, in step 307, the UE may transmit an RRC reconfiguration complete message to the source BS.

[0061] In step 308, the UE may maintain connection with the source BS and start evaluating a set of execution conditions for the set of cells. Before any execution conditions are met, when a handover (HO) command without CHO configuration is received, the UE may perform a HO procedure regardless of any previously received CHO configuration information. Otherwise, in the event that at least one execution condition for at least one cell is met, in step 309, the UE may detach from the source BS and perform (or apply) a CHO procedure to a cell selected from the at least one cell (e.g., a cell corresponding to the target BS). The selected cell may be referred to as a target cell.

[0062] Executing a CHO procedure to the selected cell may include applying a corresponding CHO configuration of the selected cell. When executing the CHO procedure, the UE no longer monitors the source BS, for example, from the time the UE starts synchronization with the selected cell. The UE may complete the CHO procedure by transmitting an RRC reconfiguration complete message to the target cell.

[0063] In step 310, the UE, the source BS, the target BS and the core network (eg, AMF and / or UPF) may perform data forwarding and path switching. For example, the target BS corresponding to the target cell may trigger the release of resources at the source BS.

[0064] Figure 4 A schematic diagram illustrating a wireless communication system 400 according to some embodiments of the present application.

[0065] As in Figure 4 As shown in , the wireless communication system 400 may support sidelink communication. In the context of the present application, sidelink communication may be classified according to the wireless communication technology employed. For example, NR sidelink communication (specified in 3GPP specification TS 38.311) may refer to access layer (AS) functionality that uses NR technology to at least implement vehicle-to-everything (V2X) communication between neighboring UEs as defined in 3GPP specification TS23.287 but does not traverse any network nodes. V2X sidelink communication (specified in 3GPP specification TS 36.311) may refer to AS functionality that uses E-UTRA technology to implement V2X communication between neighboring UEs as defined in 3GPP specification TS23.285 but does not traverse any network nodes. However, if not specified, "sidelink communication" may refer to either NR sidelink communication or V2X sidelink communication.

[0066] exist Figure 4 In the embodiment, the wireless communication system 400 may include some BSs (eg, BS 402 and BS 403) and some UEs (eg, UE 401-A, UE 401-B, and UE 401-C). Figure 4 A specific number of UEs and BSs are depicted in FIG400 , but it is contemplated that any number of UEs and BSs may be included in the wireless communication system 400. BS 402 may be a gNB, and BS 403 may be an ng-eNB. Figure 4 The UE in can be used as Figures 1 to 3 The UE shown in .

[0067] UE 401-A and UE 401-B may be within the coverage area, for example, Figure 4, UE 401-A may be within the coverage of BS 402, and UE 401-B may be within the coverage of BS 403, and UE 401-C may be out of coverage, for example, as shown in FIG. Figure 4 , UE 401-C may be out of coverage of both BS 402 and BS 403. UE 401A and UE 401-B may be connected to BS 402 and BS 403, respectively, via a network interface (e.g., a Uu interface as specified in a 3GPP standard document). BS 402 and BS 403 may be connected to each other via a network interface (e.g., an Xn interface as specified in a 3GPP standard document). UE 401-A, UE 401-B, and UE 401-C may be connected to each other, respectively, via, for example, a PC5 interface as specified in a 3GPP standard document.

[0068] Support for V2X services via the PC5 interface may be provided through NR sidelink communication and / or V2X sidelink communication. NR sidelink communication may support one of the following three types of transmission modes for a pair of source layer 2 ID and destination layer 2 ID: unicast transmission, multicast transmission, and broadcast transmission. Sidelink communication transmission and reception via the PC5 interface is supported when the UE is within coverage or out of coverage.

[0069] For example, UE 401-A within the coverage of BS 402 may perform sidelink transmission and reception (e.g., sidelink unicast transmission, sidelink multicast transmission, or sidelink broadcast transmission) through the PC5 interface. UE 401-C outside the coverage of both BS 402 and BS 403 may also perform sidelink transmission and reception through the PC5 interface.

[0070] A UE supporting sidelink communication or V2X communication may be referred to as a V2X UE. According to some other embodiments of the present application, the V2X UE may be a mobile phone, a vehicle, a road map device, a computer, a laptop, an IoT (Internet of Things) device, or other types of devices.

[0071] The V2X UE may operate in different modes. At least two sidelink resource allocation modes are defined for sidelink communications. For example, mode 1 may refer to a case where the base station schedules the sidelink resources to be used by the UE for sidelink transmission, and mode 2 may refer to a case where the UE determines the sidelink transmission resources within a resource pool. The resource pool may be configured by the base station or the network, or may be pre-configured according to a standard. In mode 2, the base station does not need to dynamically schedule sidelink resources for the UE, and the UE determines the sidelink transmission resources and timing in the resource pool based on measurement results and sensing results.

[0072] In Mode 1, the UE may need to be in the RRC_CONNECTED state in order to transmit data. The base station may dynamically schedule resources to the UE for NR sidelink communications via the Physical Downlink Control Channel (PDCCH). In addition, the base station may allocate sidelink resources to the UE using two types of configured sidelink grants (e.g., sidelink resources):

[0073] - Sidelink Configured Grant Type 1 (or Type 1): RRC directly provides a configured sidelink grant only for NR sidelink communications; and

[0074] - Sidelink configured grant type 2 (or Type 2): RRC defines the periodicity of the configured sidelink grant, while PDCCH can signal and activate or deactivate the configured sidelink grant.

[0075] For a UE performing NR sidelink communication, more than one configured sidelink grant may be active at a time on a carrier configured for sidelink transmission.

[0076] When a beam failure or physical layer problem occurs on the Uu interface, the UE may continue to use resources of the sidelink configured grant type 1. During the handover procedure, the configured sidelink grant may be provided to the UE via a handover command. When the configured sidelink grant is provided in the handover command, the UE may activate resources of the sidelink configured grant type 1 in response to receipt of the handover command.

[0077] In mode 2, the UE may transmit data when the UE is in coverage or out of coverage. The UE may autonomously select a sidelink grant from a resource pool provided by system information (e.g., system information block (SIB)) or dedicated signaling when the UE is in coverage of the BS, or autonomously select a sidelink grant from a pre-configured resource pool when the UE is out of coverage of the BS.

[0078] For NR sidelink communications, a resource pool may be provided for a given validity area, wherein the UE does not need to acquire a new resource pool when moving within the validity area, at least when a new resource pool is provided by a SIB (e.g., reusing the validity area of ​​the NR SIB). The UE may be allowed to temporarily use a UE autonomous resource selection method with random selection for sidelink transmissions based on the configuration of an exceptional transmission resource pool as specified in 3GPP specification TS 38.331.

[0079] Figure 5 An exemplary procedure for providing UE assistance information according to some embodiments of the present application is described. Figure 5In step 512, UE 501 and network 504 (eg, BS) may perform an RRC reconfiguration procedure between them. In step 514, UE 501 may transmit UE assistance information associated with itself to network 504.

[0080] The purpose of the procedure for providing UE assistance information may include, for example, one of the following:

[0081] -UE overheat assistance information;

[0082] - UE preference for discontinuous reception (DRX) parameters for power saving;

[0083] - UE preference for maximum aggregate bandwidth for power saving; and

[0084] -Sidelink information.

[0085] In some embodiments of the present application, the sidelink information included in the UE assistance information may include configured authorized assistance information for NR sidelink communication (also referred to as "UE assistance for NR sidelink communication"). For example, sl-UE-AssistanceInformationNR as specified in the 3GPP standard document may be included in the UE assistance information.

[0086] In some embodiments of the present application, the sidelink information included in the UE assistance information may include configured authorized assistance information for V2X sidelink communication (also referred to as "UE assistance for V2X sidelink communication"). For example, UEAssistanceInformationEUTRA as specified in the 3GPP standard document may be included in the UE assistance information.

[0087] In some embodiments of the present application, the configured grant assistance information may include periodicity and offset information of the UE's sidelink communication. For example, the configured grant assistance information may indicate that the periodicity of the sidelink resource is 10ms, and the offset of the sidelink resource with respect to the reference point is 2ms.

[0088] The UE assistance information for NR sidelink communication may be designed to indicate the traffic characteristics of the sidelink logical channel set up for NR sidelink communication. A UE capable of providing configured authorized assistance information for NR sidelink communication in the RRC_CONNECTED state may initiate the above procedure under certain conditions, including, for example, in response to the UE being configured to provide traffic mode information and in response to a change in the UE's traffic mode.

[0089] The UE assistance information for V2X sidelink communication may indicate the traffic characteristics of the sidelink logical channel set for the V2X sidelink communication. For example, it may be used to inform the network of the UE's semi-persistent scheduling (SPS) assistance information for V2X sidelink communication.

[0090] Figure 6 An exemplary procedure for providing sidelink UE information according to some embodiments of the present application is described. Figure 6 In the example, UE 601 is connected to a network 604 (eg, a BS).

[0091] In some embodiments of the present application, the sidelink UE information may be sidelink UE information for NR sidelink communication. In these embodiments, in step 612, UE 601 may receive SIB from network 604. In some instances, the SIB may be SIB12. In step 614, UE 601 may transmit sidelink UE information for NR sidelink communication to network 604. The sidelink UE information may be transmitted in a sidelink UE information message, for example, SidelinkUEInformationNR as specified in a 3GPP standard document. This message may also be referred to as a sidelink UE information message for NR sidelink communication.

[0092] The purpose of the above procedure may be, for example, to inform the network UE:

[0093] - is interested or no longer interested in receiving NR sidelink communications;

[0094] - Requesting the assignment or release of transmission resources for NR sidelink communications;

[0095] - Parameters and QoS profile related to NR sidelink communications are being reported;

[0096] - is reporting that a sidelink radio link failure has been detected; or

[0097] - any combination thereof.

[0098] In several cases, a UE capable of NR sidelink communication in RRC_CONNECTED state may initiate the above procedure to indicate that the UE is receiving (interested in) NR sidelink communication. These cases may include: 1) in case of successful link establishment and recovery, 2) in case of a change of interest, or 3) in case of a change of PCell providing SIB12, which includes parameters such as sl-ConfigCommonNR as specified in the 3GPP standard documents.

[0099] A UE capable of NR sidelink communication may initiate a procedure to request the assignment of dedicated resources for NR sidelink communication transmission. A UE capable of NR sidelink communication may initiate a procedure to report to the network that a sidelink radio link failure or a sidelink RRC reconfiguration failure has been declared.

[0100] In some embodiments of the present application, the sidelink UE information may be sidelink UE information for NR sidelink communication. In these embodiments, in step 612, UE 601 may receive a SIB from network 604. In some instances, the SIB may be SIB 13 or SIB 14. In step 614, UE 601 may transmit sidelink UE information for V2X sidelink communication to network 604. The sidelink UE information may be transmitted in a sidelink UE information message, for example, SidelinkUEInformationEUTRA as specified in a 3GPP standard document. This message may also be referred to as a sidelink UE information message for E-UTRA sidelink communication. The initiation and procedure of the transmission of the sidelink UE information message may follow the procedure specified for V2X sidelink communication in 3GPP specification TS 36.331.

[0101] For example, the purpose of the above procedure may include one or more of the following: notifying the network that the UE is interested or no longer interested in receiving V2X sidelink communications, requesting assignment or release of transmission resources for V2X sidelink communications, and reporting parameters related to V2X sidelink communications.

[0102] As detailed above, in certain situations, the UE may initiate a procedure to transmit UE assistance information or sidelink UE information to the network. A UE with multiple connectivity (e.g., dual connectivity) may initiate a fault reporting procedure (e.g., a fast MCG link recovery procedure) when RLF occurs. Embodiments of the present application provide a solution for handling UE assistance information and sidelink UE information during a fault reporting procedure.

[0103] In addition, the UE may be configured with resources for sidelink communications. For example, the sidelink resources may be indicated by a sidelink configured grant (e.g., indicated by an rrc-ConfiguredSidelinkGrant specified in a 3GPP standard document). Embodiments of the present application provide a solution for handling sidelink resources during a fault reporting procedure.

[0104] Additionally, embodiments of the present application provide a solution for handling side link configuration during a conditional handover procedure.

[0105] More details about the embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0106] Figure 7An exemplary procedure 700 for transmitting fault information according to some embodiments of the present disclosure is described. The details described in all the above embodiments of the present disclosure are applicable to Figure 7 Embodiments of the display.

[0107] Exemplary process 700 shows a UE (e.g., Figure 1 The UE may be in a MR-DC scenario, where the UE is connected to a MN (e.g., Figure 1 MN 102) and SN (e.g., Figure 1 SN 103 in ).

[0108] In step 712, the UE may receive configuration information from the network (e.g., a MN connected to the UE). The configuration information may be associated with a fast MCG link recovery procedure. For example, the configuration information may indicate a timer associated with fast MCG link recovery (e.g., timer T316). In some embodiments of the present application, the UE may also be configured with sidelink communications. For example, the UE may be configured with resources of a sidelink configured with grant type 1, resources of a sidelink configured with grant type 2, or both.

[0109] At some time, the UE may detect a radio link failure on an MCG associated with a MN connected to the UE. The UE may then initiate a fast MCG link recovery procedure as described above with respect to Figure 2A and 2B Description. For example, in step 714, the UE may transmit an MCG failure information message in response to detecting a radio link failure on the MCG. The MCG failure information message may be transmitted to the MN via the SN. In step 716, the UE may start a timer indicated in the configuration information received in step 712. For example, the UE may start a timer associated with fast MCG link recovery.

[0110] In some embodiments of the present application, the UE may release configured side link resources or grants during a fast MCG link recovery procedure. For example, the UE may be configured with side link configured grant type 1 resources. In some examples, the UE (e.g., lower layers, such as the physical layer and MAC layer of the UE) may release such resources in response to the start of a timer associated with fast MCG link recovery. For example, the UE may release such resources at any time while a timer associated with fast MCG link recovery is running or when a timer associated with fast MCG link recovery is started (or thereafter).

[0111] In some embodiments of the present application, the UE may be allowed to use configured sidelink resources or grants during the fast MCG link recovery procedure. For example, the UE may be configured with resources of sidelink configured grant type 1. The UE may use such resources to perform sidelink communications while the timer associated with the fast MCG link recovery is running.

[0112] In some embodiments of the present application, the UE may be allowed to transmit UE assistance information during a fast MCG link recovery procedure. While a timer associated with fast MCG link recovery is running, the UE may initiate a procedure for providing UE assistance information. For example, when a timer associated with fast MCG link recovery is running, the UE transmits UE assistance information under certain conditions, including, for example, when the UE is configured to provide business mode information and when the business mode of the UE changes.

[0113] As described above, the UE may be configured with a separate SRB1 or SRB3. In the case where a separate SRB1 is configured at the UE, the UE may transmit UE assistance information on SRB1 while a timer associated with fast MCG link recovery is running. For example, the UE may submit the UE assistance information to the lower layer for transmission via SRB1 (i.e., separate SRB1). In the case where a separate SRB3 is configured at the UE, the UE may transmit UE assistance information on SRB3 while a timer associated with fast MCG link recovery is running. For example, the UE assistance information may be encapsulated or embedded in an RRC message (e.g., an uplink information transfer message, such as ULInformationTransferMRDC as specified in the 3GPP standard document) for transmission via SRB3.

[0114] In some embodiments of the present application, the UE may be allowed to transmit sidelink UE information during the fast MCG link recovery procedure.When the timer associated with the fast MCG link recovery is running, the UE may initiate a procedure for providing sidelink UE information.

[0115] For example, while a timer associated with fast MCG link recovery is running, the UE may transmit sidelink UE information for certain purposes, including, for example, notifying the network that the UE is or is no longer interested in receiving sidelink communications, requesting the assignment or release of transmission resources for sidelink communications, reporting parameters related to sidelink communications, and reporting that a radio link failure on the sidelink has been detected.

[0116] In some instances, the sidelink UE information message may be used for NR sidelink communications. In some other instances, the sidelink UE information message may be used for E-UTRA sidelink communications.

[0117] As described above, the UE may be configured with a separate SRB1 or SRB3. In the case where a separate SRB1 is configured at the UE, the UE may transmit a sidelink UE information message on SRB1 while a timer associated with fast MCG link recovery is running. For example, the UE may submit a sidelink UE information message to a lower layer for transmission via SRB1 (i.e., separate SRB1). In the case where a separate SRB3 is configured at the UE, the UE may transmit a sidelink UE information message on SRB3 while a timer associated with fast MCG link recovery is running. For example, the sidelink UE information message may be encapsulated or embedded in an RRC message (e.g., an uplink information transfer message, such as ULInformationTransferMRDC as specified in a 3GPP standard document) for transmission via SRB3.

[0118] In some embodiments of the present application, the UE may receive an RRC reconfiguration message from the MN, for example via the SN. In embodiments that allow the UE to transmit UE assistance information, sidelink UE information, or both during the fast MCG link recovery procedure, the UE may, under certain conditions, maintain (not stop) a timer associated with the fast MCG link recovery in response to receiving an RRC reconfiguration message. For example, the UE may maintain a timer associated with the fast MCG link recovery in the following cases: (1) the RRC reconfiguration message includes only a configuration for sidelink communication, (2) the RRC reconfiguration message does not include a reconfiguration with synchronization; or (3) the RRC reconfiguration message includes an indication to maintain a timer associated with the fast MCG link recovery. Otherwise, the UE may stop the timer associated with the fast MCG link recovery.

[0119] In some embodiments of the present application, during the fast MCG link recovery procedure, the UE may not be allowed to transmit UE assistance information and sidelink UE information. In these embodiments of the present application, when the timer associated with the fast MCG link recovery is not running, the UE may transmit UE assistance information or sidelink UE information messages.

[0120] Those skilled in the art will appreciate that the sequence of operations in the exemplary process 700 may be changed, and some operations in the exemplary process 700 may be eliminated or modified without departing from the spirit and scope of the present disclosure.

[0121] Figure 8 An exemplary flow chart illustrating a CHO procedure 800 according to some embodiments of the present application. The details described in all the above embodiments of the present disclosure apply to Figure 8 For example, regarding Figure 3 The description can be applied to Figure 8 .

[0122] As in Figure 8 , a UE (e.g., UE 801) is connected to a BS (e.g., source BS 802a). In step 812 (represented by a dashed arrow as an option), UE 801 and source BS 802a may communicate with each other, for example, to perform data transmission. In some examples, source BS 802a may transmit measurement configuration information to UE 801. In step 814, UE 801 may report measurement results (e.g., RSRP, RSRQ, or the like) to source BS 802a. Figure 3 The description of step 301 in FIG. 814 may be applied to step 814. After receiving the measurement result, source BS 802a may decide to perform CHO for UE 801. In step 816, source BS 802a may transmit a CHO request message to one or more candidate BSs (eg, candidate BS 802b and candidate BS 802c).

[0123] In step 818, source BS 802a may receive a CHO response message (e.g., a handover confirmation) from one or more candidate BSs (e.g., candidate BS 802b and candidate BS 802c). Each handover confirmation from the corresponding candidate BS may include a conditional RRC reconfiguration. In some embodiments of the present disclosure, the CHO response message may also include a sidelink configuration of the UE. The sidelink configuration may be included in the conditional RRC reconfiguration. The sidelink configuration may include a configured sidelink grant for the UE. The configured sidelink grant may be a sidelink configured grant type 1, a sidelink configured grant type 2, or both.

[0124] After receiving the CHO response message, source BS 802a may generate one or more execution conditions for handing over to candidate BS 802b and candidate BS 802c. In step 822, source BS 802a may transmit an RRC reconfiguration message to UE 801, the message including conditional RRC reconfiguration, execution conditions of CHO, and sidelink configuration. UE 801 may store the RRC reconfiguration message. UE 801 may apply the sidelink configuration at a later time, as will be described below.

[0125] In step 824, UE 801 may maintain connection with source BS 802a and begin evaluating execution conditions. When at least one execution condition is met, UE 801 may detach from source BS 802a. UE 801 may then perform (or apply) a CHO procedure to a target BS (e.g., candidate BS 802b), and may access candidate BS 802b in step 826. Performing the CHO procedure may include applying a conditional RRC reconfiguration associated with the target BS and applying a sidelink configuration associated with the target BS. In some embodiments of the present disclosure, the sidelink configuration may indicate that the sidelink is configured with resources of grant type 1. The UE may activate resources of the sidelink configured with grant type 1.

[0126] In step 828, the UE may transmit an RRC reconfiguration complete message to the candidate BS 802b. In step 832, the candidate BS 802b may perform a path switching procedure with respect to a core network entity (e.g., AMF). In step 834, the candidate BS 802b may notify the source BS 802a that the handover is successfully completed.

[0127] Those skilled in the art will appreciate that the sequence of operations in the exemplary process 800 may be changed, and some operations in the exemplary process 800 may be eliminated or modified without departing from the spirit and scope of the present disclosure.

[0128] Fig. 9 An example block diagram illustrating an apparatus 900 according to some embodiments of the present disclosure. The apparatus 900 may be a BS or a UE.

[0129] refer to Fig. 9 , the apparatus 900 may include at least one non-transitory computer-readable medium 902, at least one receiving circuit system 904, at least one transmitting circuit system 906, and at least one processor 908. In some embodiments of the present application, the at least one receiving circuit system 904 and the at least one transmitting circuit system 906 may be integrated into at least one transceiver. At least one processor 908 may be coupled to the at least one non-transitory computer-readable medium 902, the at least one receiving circuit system 904, and the at least one transmitting circuit system 906. In some embodiments of the present disclosure, the apparatus 900 may further include an input device, a memory, and / or other components.

[0130] In some embodiments of the present disclosure, at least one non-transitory computer-readable medium 902 may store computer-executable instructions thereon to cause at least one processor 908 to implement operations, steps, or methods related to the UE as described above. For example, when the computer-executable instructions are executed, the at least one processor 908 interacts with at least one receiving circuit system 904 and at least one transmitting circuit system 906 to facilitate execution of the related Figures 1 to 3and the steps of the UE depicted in 5 to 8. In some examples, at least one receiving circuit system 904 may receive configuration information indicating a timer associated with fast MCG link recovery. At least one transmitting circuit system 906 may transmit an MCG failure information message in response to detecting a radio link failure on the MCG. At least one processor 908 may start a timer associated with fast MCG link recovery.

[0131] In some embodiments of the present disclosure, at least one non-transitory computer-readable medium 902 may store computer-executable instructions thereon to cause at least one processor 908 to implement operations, steps, or methods related to the BS as described above. For example, when the computer-executable instructions are executed, the at least one processor 908 interacts with at least one receiving circuit system 904 and at least one transmitting circuit system 906 to perform Figures 1 to 3 and the steps regarding the UE described in 5 to 8.

[0132] Those of ordinary skill in the art will appreciate that the steps of the methods described in conjunction with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. Additionally, in some aspects, the steps of the methods may reside as one or any combination or group of codes and / or instructions on a non-transitory computer-readable medium that may be incorporated into a computer program product.

[0133] Although the present disclosure has been described with specific embodiments of the present disclosure, it is apparent that many alternatives, modifications and variations may be apparent to those skilled in the art. For example, in other embodiments, the various components of the embodiments may be interchangeable, added or replaced. In addition, all elements of each figure are not necessary for the operation of the disclosed embodiments. For example, a person of ordinary skill in the art of the disclosed embodiments will be able to make and use the teachings of the present disclosure by simply adopting the elements of the independent claims. Therefore, the embodiments of the present disclosure set forth herein are intended to be illustrative, rather than restrictive. Various changes may be made without departing from the spirit and scope of the present disclosure.

[0134] In this document, the term "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment comprising a series of elements not only comprises the elements, but also may comprise other elements not explicitly listed or inherent to the process, method, article or equipment. In the absence of more constraints, elements beginning with "one" or the like do not exclude the presence of additional equivalent elements in the process, method, article or equipment comprising the elements. In addition, the term "another" is defined as at least the second or more. The term "having" and the like as used herein are defined as "comprising".

Claims

1. A method for wireless communication, comprising: receiving an RRC reconfiguration message including a conditional radio resource control RRC reconfiguration, an execution condition of a conditional handover CHO, and a side link configuration; executing the CHO procedure when the execution condition of the CHO is met; and An RRC reconfiguration complete message is transmitted in response to completion of the CHO procedure.

2. The method of claim 1 , wherein the conditional RRC reconfiguration comprises the sidelink configuration, and the method further comprises: The sidelink configuration is stored in response to receipt of the conditional RRC reconfiguration.

3. The method of claim 1, wherein performing the CHO procedure comprises: Applying the conditional RRC reconfiguration; and The sidelink configuration is applied.

4. The method of claim 1 , wherein the sidelink configuration indicates a first type of configured authorized sidelink resources, and applying the sidelink configuration comprises: The sidelink resources of the first type that are granted by the configuration are activated.

5. A device for wireless communication, comprising: Receiving circuit system; Transmission circuit system; as well as a processor coupled to the receive circuitry and the transmit circuitry and configured to cause the apparatus to: receiving an RRC reconfiguration message including a conditional radio resource control RRC reconfiguration, an execution condition of a conditional handover CHO, and a side link configuration; executing the CHO procedure when the execution condition of the CHO is met; and An RRC reconfiguration complete message is transmitted in response to completion of the CHO procedure.

6. The apparatus of claim 5, wherein the conditional RRC reconfiguration comprises the sidelink configuration, and the processor is further configured to cause the apparatus to: The sidelink configuration is stored in response to receipt of the conditional RRC reconfiguration.

7. The apparatus of claim 5, wherein to perform the CHO procedure, the processor is configured to cause the apparatus to: applying the conditional RRC reconfiguration; and The sidelink configuration is applied.

8. The apparatus of claim 5, wherein the sidelink configuration indicates a first type of configured authorized sidelink resources, and to apply the sidelink configuration, the processor is configured to cause the apparatus to: The sidelink resources of the first type that are granted by the configuration are activated.

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