Method and apparatus for handling relay links with TAU and RNAU in L2 U2N relay case

Abstract

An embodiment of the present application relates to a method and apparatus for processing a relay link with a tracking area update (TAU) and a radio access network-based notification area update (RNAU) in a layer 2 (L2) UE-to-network (U2N) relay case. According to an embodiment of the present application, a user equipment (UE) includes a processor and a transceiver coupled to the processor, the processor is configured to access a serving cell via the relay UE and receive a radio resource control (RRC) message from the serving cell via the transceiver, the RRC message including at least one of an RRC reconfiguration message or an RRC release message.

Description

[Technical field]

[0001] The embodiments of the present application generally relate to wireless communication technologies, and more particularly, to a method and apparatus for processing relay links with Tracking Area Updates (TAU) and Radio Access Network-based Notification Area Updates (RNAU) in Layer 2 (L2) UE-to-Network (U2N) relay cases. [Background technology]

[0002] Vehicle-to-Vehicle and Vehicle-to-Infrastructure (V2X) have been introduced into 5G wireless communication technology. From the perspective of the channel structure of V2X communication, the direct link between two User Equipments (UEs) is called sidelink. Sidelink is a Long-Term Evolution (LTE) feature introduced in 3GPP Release 12 that enables direct communication between nearby UEs, and data does not need to go through the base station (BS) or core network.

[0003] The Third Generation Partnership Project (3GPP (registered trademark, hereinafter the same)) is promoting the introduction of relay nodes (RNs) in wireless communication systems. One purpose of deploying RNs is to extend the coverage area of ​​a BS by improving the throughput of user equipment (UE) located within the coverage of the BS or far away from the BS, which may relatively degrade the signal quality. RNs are also sometimes referred to as relay UEs. A 3GPP 5G sidelink system including relay UEs is sometimes referred to as a sidelink relay system. A U2N relay UE is a UE that provides the functionality to support the connection of U2N remote UEs to the network.

[0004] Currently, details regarding the processing of relay links using TAU and RNAU in the case of L2 U2N relay in wireless communication systems and the like have not yet been specifically discussed. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] 3GPP Release 12 [Non-Patent Document 2] 3GPP Standards Documents [Non-Patent Document 3] IEEE702.11 Family [Non-Patent Document 4] 3GPP 5G Protocols [Non-Patent Document 5] 3GPP standard document TS38.331 [Non-Patent Document 6] Section 5.3.14.4 of TS38.331 Summary of the Invention [Means for solving the problem]

[0006] Some embodiments of the present application provide a user equipment (UE), the UE including a processor and a transceiver coupled to the processor, the processor configured to access a serving cell via a relay UE and receive a radio resource control (RRC) message from the serving cell via the transceiver, the RRC message including at least one of an RRC reconfiguration message or an RRC release message.

[0007] In some embodiments, in response to the RRC message including an RRC reconfiguration message, the RRC reconfiguration message includes a measurement configuration, and the measurement configuration includes at least one of a blacklist of cells, where each cell in the blacklist of cells is not applicable for the event evaluation or measurement procedure, or a whitelist of cells, where each cell in the whitelist of cells is applicable for the event evaluation or measurement procedure.

[0008] In some embodiments, in response to the relay UE's serving cell belonging to the blacklist, the relay UE is not applicable for the event evaluation or measurement procedure. In some embodiments, in response to the relay UE's serving cell belonging to the whitelist, the relay UE is applicable for the event evaluation or measurement procedure. In some embodiments, in response to the relay UE's serving cell belonging to neither the blacklist nor the whitelist, the relay UE is not applicable for the event evaluation or measurement procedure or the relay UE is applicable for the event evaluation or measurement procedure.

[0009] In some embodiments, the processor of the UE is configured to report the measurement result when an event associated with the relay UE is satisfied during execution of the event evaluation, in response to the relay UE being applicable to the event evaluation or measurement procedure.

[0010] In some embodiments, the event associated with the relay UE includes one of: the relay UE becoming worse than a first threshold and the second cell becoming better than a second threshold; the relay UE becoming worse than a third threshold; the relay UE becoming worse than a fourth threshold and the candidate relay UE becoming better than a fifth threshold; or the candidate relay UE becoming better than a sixth threshold.

[0011] In some embodiments, the processor of the UE is configured to enter an RRC idle state in response to the RRC message including an RRC release message, to initiate an RRC setup request procedure, and to start a timer associated with the RRC setup request upon sending the RRC setup request message.

[0012] In some embodiments, the processor of the UE is configured to perform a unified access control procedure in response to initiation of an RRC setup request procedure.

[0013] In some embodiments, the processor of the UE is configured to start a timer associated with an access barring check in response to the UE's access attempt being considered barred.

[0014] In some embodiments, the processor of the UE is configured to stop the timer associated with the access barring check in response to the timer being running and in response to satisfying at least one of relay selection or reselection, a change of serving cell due to relay selection or reselection, relay reselection, and receiving a notification message from the relay UE associated with an indication of at least one of a handover of the relay UE, a Radio Link Failure (RLF) on the Uu link of the relay UE, or a cell reselection of the relay UE.

[0015] In some embodiments, in response to receiving a notification message including an indication of cell reselection from the relay UE, and in response to the reselected cell and the serving cell belonging to different tracking areas, the processor of the UE is configured to: in response to the timer associated with the RRC setup request being running, stop a timer associated with the RRC setup request and perform a Tracking Area Update (TAU) procedure, or perform an RRC setup procedure.

[0016] In some embodiments, the processor of the UE is configured to, in response to receiving a notification message associated with a declaration of a Radio Link Failure (RLF) or an indication of at least one of a handover of the relay UE or an RLF on a Uu link of the relay UE, initiate an RRC re-establishment procedure, send an RRC re-establishment request message, and start a timer associated with the RRC re-establishment request.

[0017] In some embodiments, in response to receiving a notification message including an indication of cell reselection from the relay UE, and in response to the reselected cell and the serving cell belonging to different tracking areas, the processor of the UE is configured to: in response to the timer associated with the RRC re-establishment request being running, stop a timer associated with the RRC re-establishment request and perform a Tracking Area Update (TAU) procedure, or perform an RRC re-establishment procedure.

[0018] In some embodiments, the processor of the UE is configured to, in response to the RRC message including an RRC release message and in response to the RRC release message including a suspend indication, enter an RRC inactive state, send an RRC resume request message, and start a timer associated with the RRC resume request.

[0019] In some embodiments, in response to receiving a notification message including an indication of cell reselection from the relay UE, and in response to the reselected cell and the serving cell belonging to different Radio Access Network-based Notification Areas (RNA), the processor of the UE is configured to: in response to a timer associated with the RRC restart request being running, stop a timer associated with the RRC restart request and perform a Radio Access Network-based Notification Area Update (RNAU) procedure, or perform an RRC restart procedure.

[0020] In some embodiments, the notification message received from the relay UE includes identity (ID) information of the reselected cell, in some embodiments, the ID information of the reselected cell includes at least one of a new radio cell identity (NCI) of the reselected cell, a cell ID of the reselected cell, or a public land mobile network (PLMN) ID of the reselected cell.

[0021] In some embodiments, the RRC resume request message includes a resume cause. In response to performing an RNAU procedure, the resume cause is associated with the RNAU procedure. In response to performing an RRC resume procedure, the resume cause is associated with transmitting data or signaling.

[0022] Some embodiments of the present application provide a network node (e.g., BS), including a processor and a transceiver coupled to the processor, the processor configured to transmit, via the transceiver, a measurement configuration to a remote user equipment (UE) via a relay UE, the remote UE communicating with a serving cell of the network node via the relay UE, the measurement configuration including at least one of a blacklist of cells, where each cell in the blacklist of cells is not applicable for an event evaluation or measurement procedure, or a whitelist of cells, where each cell in the whitelist of cells is applicable for an event evaluation or measurement procedure.

[0023] In some embodiments, in response to the relay UE belonging to the blacklist, the relay UE is not applicable for the event evaluation or measurement procedure. In some embodiments, in response to the relay UE belonging to the whitelist, the relay UE is applicable for the event evaluation or measurement procedure. In some embodiments, in response to the relay UE belonging to neither the blacklist nor the whitelist, the relay UE is not applicable for the event evaluation or measurement procedure or the relay UE is applicable for the event evaluation or measurement procedure.

[0024] In some embodiments, the processor of the network node is configured to receive the measurement result when an event associated with the relaying UE is met during execution of the event evaluation, in response to the relaying UE being applicable to the event evaluation or measurement procedure.

[0025] In some embodiments, the event associated with the relay UE includes one of: the relay UE becoming worse than a first threshold and the second cell becoming better than a second threshold; the relay UE becoming worse than a third threshold; the relay UE becoming worse than a fourth threshold and the candidate relay UE becoming better than a fifth threshold; or the candidate relay UE becoming better than a sixth threshold.

[0026] Some embodiments of the present application provide a relay UE, the relay UE including: a processor; and a transceiver coupled to the processor, the processor being configured to: access a first serving cell, where a remote UE communicates with the first serving cell through the relay UE; perform a handover procedure or declare a radio link failure (RLF) on a Uu link of the relay UE; and send a notification message associated with at least one indication of the handover procedure or the RLF on the Uu link of the relay UE.

[0027] In some embodiments, the processor of the relay UE is configured to transmit a discovery message including identification (ID) information of the second serving cell in response to at least one of a handover procedure being successfully completed or a radio resource control (RRC) re-establishment procedure being successfully completed.

[0028] In some embodiments, the ID information of the second serving cell includes at least one of a new radio cell identity (NCI) of the second serving cell, a cell ID of the second serving cell, or a public land mobile network (PLMN) ID of the second serving cell.

[0029] Some embodiments of the present application provide a method that may be performed by a UE, the method including: accessing a serving cell via a relay UE; and receiving a radio resource control (RRC) message from the serving cell, the RRC message including at least one of an RRC reconfiguration message or an RRC release message.

[0030] In some embodiments, in response to the RRC message including an RRC reconfiguration message, the RRC reconfiguration message includes a measurement configuration, and the measurement configuration includes at least one of a blacklist of cells, where each cell in the blacklist of cells is not applicable for the event evaluation or measurement procedure, or a whitelist of cells, where each cell in the whitelist of cells is applicable for the event evaluation or measurement procedure.

[0031] In some embodiments, in response to the relay UE's serving cell belonging to the blacklist, the relay UE is not applicable for the event evaluation or measurement procedure, or in response to the relay UE's serving cell belonging to the whitelist, the relay UE is applicable for the event evaluation or measurement procedure.

[0032] In some embodiments, in response to the relay UE's serving cell not belonging to either the blacklist or the whitelist, the relay UE is not applicable for the event evaluation or measurement procedure, or the relay UE is applicable for the event evaluation or measurement procedure.

[0033] In some embodiments, the method further comprises the step of reporting a measurement result when an event associated with the relay UE is satisfied during execution of the event evaluation, in response to the relay UE being applicable for the event evaluation or measurement procedure.

[0034] In some embodiments, the event associated with the relay UE includes one of: the relay UE becoming worse than a first threshold and the second cell becoming better than a second threshold; the relay UE becoming worse than a third threshold; the relay UE becoming worse than a fourth threshold and the candidate relay UE becoming better than a fifth threshold; or the candidate relay UE becoming better than a sixth threshold.

[0035] In some embodiments, the method further comprises the steps of entering an RRC idle state in response to the RRC message including an RRC release message, initiating an RRC setup request procedure, and starting a timer associated with the RRC setup request upon sending the RRC setup request message.

[0036] In some embodiments, the method further comprises performing a unified access control procedure in response to initiating the RRC Setup Request procedure.

[0037] In some embodiments, the method further comprises starting a timer associated with an access barring check in response to the UE's access attempt being considered barred.

[0038] In some embodiments, the method further comprises stopping a timer associated with the access barring check in response to the timer being running and in response to satisfying at least one of relay selection or reselection, a change of serving cell due to relay selection or reselection, relay reselection, and a notification message associated with at least one indication of a handover of the relay UE, a Radio Link Failure (RLF) on the Uu link of the relay UE, or a cell reselection of the relay UE from the relay UE.

[0039] In some embodiments, in response to receiving a notification message including an indication of cell reselection from the relay UE and in response to the reselected cell and the serving cell belonging to different tracking areas, the method further comprises, in response to the timer associated with the RRC setup request being running, stopping a timer associated with the RRC setup request, performing a Tracking Area Update (TAU) procedure, or performing an RRC setup procedure.

[0040] In some embodiments, the method further comprises initiating an RRC re-establishment procedure in response to receiving a notification message associated with a declaration of a Radio Link Failure (RLF) or an indication of at least one of a handover of the relay UE or an RLF on a Uu link of the relay UE, sending an RRC re-establishment request message, and starting a timer associated with the RRC re-establishment request.

[0041] In some embodiments, in response to receiving a notification message including an indication of cell reselection from the relay UE and in response to the reselected cell and the serving cell belonging to different tracking areas, the method further comprises, in response to a timer associated with the RRC re-establishment request being running, stopping a timer associated with the RRC re-establishment request and performing a Tracking Area Update (TAU) procedure or performing an RRC re-establishment procedure.

[0042] In some embodiments, the method further comprises the steps of entering an RRC inactive state in response to the RRC message including an RRC release message and in response to the RRC release message including a suspend indication, sending an RRC resume request message, and starting a timer associated with the RRC resume request.

[0043] In some embodiments, the method further comprises the steps of: in response to receiving a notification message from the relay UE including an indication of cell reselection, and in response to the reselected cell and the serving cell belonging to different Radio Access Network based Notification Areas (RNA), in response to a timer associated with the RRC Restart Request being running, stopping a timer associated with the RRC Restart Request and performing a Radio Access Network based Notification Area Update (RNAU) procedure or performing an RRC Restart procedure.

[0044] In some embodiments, the notification message received from the relay UE includes identity (ID) information of the reselected cell. In some embodiments, the ID information of the reselected cell includes at least one of a new radio cell identity (NCI) of the reselected cell, a cell ID of the reselected cell, or a public land mobile network (PLMN) ID of the reselected cell.

[0045] In some embodiments, the RRC resume request message includes a resume cause, and in response to performing an RNAU procedure, the resume cause is associated with the RNAU procedure, or in response to performing an RRC resume procedure, the resume cause is associated with the transmission of data or signaling.

[0046] Some embodiments of the present application provide a method that may be performed by a network node (e.g., a BS), comprising transmitting a measurement configuration to a remote user equipment (UE) via a relay UE, the remote UE communicating with a serving cell of the network node via the relay UE, the measurement configuration including at least one of a blacklist of cells, where each cell in the blacklist of cells is not applicable for an event evaluation or measurement procedure, or a whitelist of cells, where each cell in the whitelist of cells is applicable for an event evaluation or measurement procedure.

[0047] In some embodiments, in response to the relay UE belonging to the blacklist, the relay UE is not applicable for the event evaluation or measurement procedure. In some embodiments, in response to the relay UE belonging to the whitelist, the relay UE is applicable for the event evaluation or measurement procedure. In some embodiments, in response to the relay UE belonging to neither the blacklist nor the whitelist, the relay UE is not applicable for the event evaluation or measurement procedure or the relay UE is applicable for the event evaluation or measurement procedure.

[0048] In some embodiments, the method further comprises receiving a measurement result when an event associated with the relay UE is met during execution of the event evaluation in response to the relay UE being applicable for the event evaluation or measurement procedure.

[0049] In some embodiments, the event associated with the relay UE includes one of: the relay UE becoming worse than a first threshold and the second cell becoming better than a second threshold; the relay UE becoming worse than a third threshold; the relay UE becoming worse than a fourth threshold and the candidate relay UE becoming better than a fifth threshold; or the candidate relay UE becoming better than a sixth threshold.

[0050] Some embodiments of the present application provide a method that may be performed by a relay UE, the method including: accessing a first serving cell, where a remote UE communicates with the first serving cell through the relay UE; performing a handover procedure or declaring a radio link failure (RLF) on a Uu link of the relay UE; and sending a notification message associated with at least one indication of the handover procedure or the RLF on the Uu link of the relay UE.

[0051] In some embodiments, the method further comprises transmitting a discovery message including identification (ID) information of the second serving cell in response to at least one of the handover procedure being successfully completed or the radio resource control (RRC) re-establishment procedure being successfully completed.

[0052] In some embodiments, the ID information of the second serving cell includes at least one of a new radio cell identity (NCI) of the second serving cell, a cell ID of the second serving cell, or a public land mobile network (PLMN) ID of the second serving cell.

[0053] Some embodiments of the present application also provide an apparatus for wireless communication, the apparatus including a non-transitory computer-readable medium having computer-executable instructions stored thereon, a receiving circuit, a transmitting circuit, and a processor coupled to the non-transitory computer-readable medium, the receiving circuit, and the transmitting circuit, the computer-executable instructions causing the processor to implement any of the above-mentioned methods performed by a UE, a relay UE, or a network node (e.g., a BS).

[0054] The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will become apparent from the description and drawings, and from the claims.

[0055] To explain how the advantages and features of the present application can be obtained, the present application will be described with reference to specific embodiments that are illustrated in the accompanying drawings. These drawings depict only exemplary embodiments of the present application and therefore should not be considered as limiting the scope of the present application. [Brief description of the drawings]

[0056] [Figure 1] 1 is a schematic diagram of a wireless communication system in accordance with some embodiments of the present application. [Diagram 2] 1 is an example flowchart of a sidelink RRC reconfiguration procedure according to some embodiments of the present application. [Diagram 3] 4 is a flowchart of an example procedure for wireless communication in accordance with some embodiments of the present disclosure. [Figure 4] 4 is a flowchart of an example procedure for wireless communication in accordance with some embodiments of the present disclosure. [Diagram 5] 4 is a flowchart of an example procedure for wireless communication in accordance with some embodiments of the present disclosure. [Figure 6] FIG. 2 is an exemplary block diagram of an apparatus in a L2 U2N relay case according to some embodiments of the present application. [Figure 7]FIG. 13 is a further exemplary block diagram of an apparatus in a case of L2 U2N relay according to some embodiments of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0057] The detailed description of the accompanying drawings is intended to illustrate preferred embodiments of the present application and is not intended to represent the only form in which the present application may be practiced. It is to be understood that the same or equivalent functions may be accomplished by different embodiments that are intended to be encompassed within the spirit and scope of the present application.

[0058] Reference will now be made in detail to some embodiments of the present application, examples of which are illustrated in the accompanying drawings. For ease of understanding, the embodiments are provided under specific network architectures and new service scenarios, such as 3rd Generation Partnership Project (3GPP) LTE and LTE Advanced, 3GPP 5G NR, 5G Advanced, 6G, etc. With the development of network architectures and new service scenarios, it is contemplated that all embodiments of the present application are also applicable to similar technical problems, and further, the terms listed in the present application may be changed, which should not affect the principle of the present application.

[0059] 1 illustrates a schematic diagram of a wireless communication system 100 in accordance with some embodiments of the present application. As shown in FIG 1, the wireless communication system 100 includes, for illustrative purposes, a UE 101, a BS 102, and a relay UE 103. Although a particular number of UEs, relay UEs, and BSs are shown in FIG 1, it is contemplated that any number of UEs, relay UEs, and BSs may be included in the wireless communication system 100.

[0060] Because the distance between the UE 101 and the BS 102 is long, they communicate with each other through the relay UE 103. The UE 101 may be connected to the relay UE 103 through a network interface, for example, a PC5 interface defined in a 3GPP standard document. The relay UE 103 may be connected to the BS 102 through a network interface, for example, a Uu interface defined in a 3GPP standard document. Referring to FIG. 1, the UE 101 is connected to the relay UE 103 through a PC5 link, and the relay UE 103 is connected to the BS 102 through a Uu link. The UE 101 may be a U2N remote UE. The relay UE 103 may be a U2N relay UE, which is a UE that provides a function to support connection to a network for the U2N remote UE.

[0061] In some embodiments of the present application, the UE 101 or relay UE 103 may include computing devices such as desktop computers, laptop computers, personal digital assistants (PDAs), tablet computers, smart televisions (e.g., televisions connected to the Internet), set-top boxes, gaming consoles, security systems (including security cameras), in-vehicle computers, network devices (e.g., routers, switches, and modems), etc.

[0062] In some further embodiments of the present application, the UE 101 or relaying UE 103 may include a portable wireless communications device, a smartphone, a cellular telephone, a flip phone, a device having a subscriber identity module, a personal computer, selective call receiving circuitry, or any other device capable of sending and receiving communication signals over a wireless network.

[0063] In some other embodiments of the present application, the UE 101 or relaying UE 103 may include a wearable device such as a smart watch, a fitness band, an optical head mounted display, etc. Additionally, the UE 101 or relaying UE 103 may be referred to as a subscriber unit, a mobile, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a subscriber station, a user terminal, or a device, or may be described using other terms used in the art.

[0064] The BSs 102 may be distributed across a geographic region. In certain embodiments of the present application, each of the BSs 102 may also be referred to as an access point, access terminal, base, base unit, macro cell, Node B, evolved Node B (eNB), gNB, Home Node B, relay node, or device, or may be described using other terms used in the art. The BSs 102 are generally part of a radio access network, which may include one or more controllers communicatively coupled to one or more corresponding BSs 102.

[0065] The wireless communication system 100 may be compatible with any type of network capable of transmitting and receiving wireless communication signals. For example, the wireless communication system 100 may be compatible with a wireless communication network, a cellular telephone network, a time division multiple access (TDMA)-based network, a code division multiple access (CDMA)-based network, an orthogonal frequency division multiple access (OFDMA)-based network, an LTE network, a 3GPP-based network, a 3GPP 5G network, a satellite communication network, a high altitude platform network, and / or other communication networks.

[0066] In some embodiments of the present application, the wireless communication system 100 is compatible with the 3GPP protocol 5G NR, where the BS 102 transmits data using an OFDM modulation scheme on the downlink (DL) and the UE 101 (e.g., the UE 101 or other similar UEs) transmits data on the uplink (UL) using a Discrete Fourier Transform Spread Orthogonal Frequency Division Multiplexing (DFT-S-OFDM) or Cyclic Prefix OFDM (CP-OFDM) scheme. However, more generally, the wireless communication system 100 may implement some other open or proprietary communication protocol, such as, for example, WiMAX, among others.

[0067] In some embodiments of the present application, the BS 102 may communicate using other communication protocols, such as the IEEE 702.11 family of wireless communication protocols. Additionally, in some embodiments of the present application, the BS 102 may communicate over a licensed spectrum, while in other embodiments, the BS 102 may communicate over an unlicensed spectrum. This application is not intended to be limited to any particular wireless communication system architecture or protocol implementation. In further embodiments of the present application, the BS 102 may communicate with the UE 101 using 3GPP 5G protocols.

[0068] The UE 101 may access the BS 102 to receive data packets from the BS 102 via a downlink channel and / or to transmit data packets to the BS 102 via an uplink channel. In normal operation, the UE 101 does not know when the BS 102 will transmit a data packet to the UE 101, so it must be constantly awake to monitor the downlink channel (e.g., the physical downlink control channel (PDCCH)) to be ready to receive data packets from the BS 102. However, if the UE 101 keeps constantly monitoring the downlink channel even when there is no traffic between the BS 102 and the UE 101, a significant power waste occurs, which is problematic for power-limited or power-sensitive UEs.

[0069] 2 illustrates an example flow chart of a sidelink RRC reconfiguration procedure according to some embodiments of the present application. As shown in FIG. 2, in step 201, UE(a) (e.g., UE 101 shown and illustrated in FIG. 1) initiates a sidelink RRC reconfiguration procedure for UE(b) (e.g., relay UE 103 shown and illustrated in FIG. 1) by sending an RRCReconfigurationSidelink message to UE(b).

[0070] If the sidelink RRC reconfiguration procedure is completed successfully, then in step 202 UE(b) may send to UE(a) an "RRC reconfiguration complete sidelink message", e.g., an RRCReconfigurationCompleteSidelink message as defined in the 3GPP standard documents. Alternatively, if the sidelink RRC reconfiguration procedure is not completed successfully, then in step 202 UE(b) may send to UE(a) an "RRC reconfiguration failure sidelink message", e.g., an RRCReconfigurationFailureSidelink message as defined in the 3GPP standard documents.

[0071] The purpose of the sidelink RRC reconfiguration procedure is to modify the PC5 RRC connection, e.g., to establish, modify, or release sidelink data radio bearers (DRBs), to configure NR sidelink measurements and reporting, and to configure sidelink channel state information (CSI) reference signal resources.

[0072] A UE (e.g., UE (a) shown and illustrated in FIG. 2) may initiate a sidelink RRC reconfiguration procedure and perform operations on the corresponding PC5 RRC connection when: - release of a sidelink DRB associated with a peer UE (e.g., UE (b) shown and illustrated in FIG. 2); - Establishment of a sidelink DRB associated with the peer UE; - modifying parameters contained in the Sidelink Radio Bearer (SLRB)-Config of the Sidelink DRB associated to the peer UE; - configuration information of the peer UE for performing NR sidelink measurements and reporting; - Configuration information for sidelink CSI reference signal resources.

[0073] A UE capable of NR sidelink communication may initiate a Sidelink UE Information procedure for NR to report to the network or BS that a sidelink Radio Link Failure (RLF) (e.g., expiration of timer T400) or a sidelink RRC reconfiguration failure has been declared.

[0074] According to 3GPP standard documents, the agreement on core network (CN) registration of UE in RRC idle state (also called idle UE) is as follows: Reachability management is responsible for detecting whether the UE is reachable and providing the UE's location (i.e., access node) so that the network can reach the UE. This is done by UE paging and UE location tracking. UE location tracking includes both UE registration area tracking (i.e., UE registration area update) and UE reachability tracking (i.e., UE periodic registration area update). Based on the above description, there are two trigger conditions to trigger the UE to perform CN registration, namely, the change of registration area and the expiration of the registration timer (periodic registration update timer). The CN registration area (TrackingAreaCode IE (information element)) is broadcast by SIB1 (system information block 1). If the idle UE leaves this registration area, the idle UE needs to perform CN registration by establishing a connection.

[0075] According to the 3GPP standard documents, the agreement on Radio Access Network (RAN) based notification areas is as follows: A UE in RRC_INACTIVE state can be configured by the last serving NG-RAN node with an RNA. The RNA can cover a single or multiple cells and must be contained within the CN registration area and, in this release, an Xn connection must be available within the RNA. RAN based notification area updates (RNAU) are sent by the UE periodically and also when the UE cell reselection procedure selects a cell that does not belong to the configured RNA.

[0076] The RNA update sequence including context acquisition may be triggered when the UE moves out of the configured RNA or periodically. During the UE-triggered RNA update procedure including context acquisition over the Xn interface, the UE resumes from RRC_INACTIVE and provides the I-RNTI assigned by the last serving BS (e.g., gNB) and an appropriate cause value, e.g., RAN notification area update. If the gNB can resolve the gNB identity included in the I-RNTI, it requests the last serving gNB to provide the UE context, providing the received cause value. The last serving gNB may then provide the UE context. The gNB may return the UE to RRC_INACTIVE. The gNB provides a forwarding address if necessary to prevent loss of buffered DL user data at the last serving gNB. The gNB then performs a path switch. The gNB keeps the UE in RRC_INACTIVE state by sending a RRCRelease including a suspend indication. The gNB then triggers the release of UE resources at the last serving gNB.

[0077] According to the agreement of 3GPP standard documents, four reporting events associated with L2 U2N relay UE are introduced, namely event X1, event X2, event Y1 and event Y2, as follows: (1) Event X1 (serving L2 U2N relay UE becomes worse than threshold 1, and NR cell becomes better than threshold 2) 1> The UE shall consider the entering condition of this event to be satisfied if both condition X1-1 and condition X1-2 specified below are satisfied. 1> The UE shall consider the leaving condition of this event to be satisfied if at least one of condition X1-3 or condition X1-4, i.e. the two specified below, is satisfied. Inequality X1-1 (entering condition 1): Mr+Hys <Thresh1 Inequality X1-2 (entering condition 2): Mn+Ofn+Ocn-Hys>Thresh2 Inequality X1-3 (Leaving condition 1): Mr-Hys>Thresh1 Inequality X1-4 (Leaving condition 2): Mn+Ofn+Ocn+Hys <Thresh2 The variables in the formula are defined as follows: · Mr is the measurement result of the serving L2 U2N relay UE without considering the offset. ·Mn is the measurement result of an NR cell without considering the offset. Ofn is the measurement object specific offset of the frequency of the NR cell. · Ocn is a cell-specific offset for NR cells, and is set to zero if not configured in the cell. ·Hys is the hysteresis parameter for this event. ·Thresh1 is the threshold parameter for this event (i.e., x1-Threshold1-Relay as defined in reportConfigNR for this event). ·Thresh2 is the threshold parameter for this event (i.e., x1-Threshold2 as defined in reportConfigNR for this event). · Mr is expressed in dBm. ·Mn is expressed in dBm for RSRP and in dB for RSRQ and RS-SINR. Ofn, Ocn, Hys are expressed in dB. · Thresh1 is expressed in the same units as Mr. ·Thresh2 is expressed in the same units as Mn. (2) Event X2 (Serving L2 U2N relay UE becomes worse than the threshold) 1> The UE shall consider the entering conditions for this event to be met when condition X2-1 specified below is met. 1> The UE shall consider the leaving conditions for this event to be met when condition X2-2 specified below is met. Inequality X2-1 (entering condition): Mr+Hys <Thresh Inequality X2-2 (leaving condition): Mr-Hys>Thresh The variables in the formula are defined as follows: · Mr is the measurement result of the serving L2 U2N relay UE without considering the offset. ·Hys is the hysteresis parameter for this event. ·Thresh is the threshold parameter for this event (i.e., x2-Threshold-Relay defined in reportConfigNR for this event). · Mr is expressed in dBm. · Hys is expressed in dB. · Thresh is expressed in the same units as Mr. (3) Event Y1 (PCell becomes worse than threshold 1 and candidate L2 U2N relay UE becomes better than threshold 2) 1> The UE shall consider the entering conditions of this event to be met when both condition Y1-1 and condition Y1-2 specified below are met. 1> The UE shall consider the leaving condition of this event to be satisfied if at least one of condition Y1-3 or condition Y1-4, i.e., the two specified below, is satisfied. Inequality Y1-1 (entering condition 1): Mp + Hys <Thresh1 Inequality Y1-2 (entering condition 2): Mr-Hys>Thresh2 Inequality Y1-3 (Leaving condition 1): Mp-Hys>Thresh1 Inequality Y1-4 (Leaving condition 2): Mr+Hys <Thresh2 The variables in the formula are defined as follows: · Mp is the measurement result of the PCell without taking into account the offset. · Mr is the measurement result of the candidate L2 U2N relay UE without considering the offset. ·Hys is the hysteresis parameter for this event (i.e. the hysteresis defined in reportConfigInterRAT for this event). ·Thresh1 is the threshold parameter for this event (i.e. y1-Threshold1 defined in reportConfigInterRAT for this event). ·Thresh2 is the threshold parameter for this event (i.e. y1-Threshold2-Relay defined in reportConfigInterRAT for this event). · Mp is expressed in dBm for RSRP and in dB for RSRQ and SINR. · Mr is expressed in dBm or dB depending on the measurement quantity of the candidate L2 U2N relay UE. · Hys is expressed in dB. · Thresh1 is expressed in the same units as Mp. · Thresh2 is expressed in the same units as Mr. (4) Event Y2 (candidate L2 U2N relay UE becomes better than threshold) 1>UE shall consider the entering conditions of this event to be satisfied when condition Y2-1 specified below is satisfied. 1> The UE shall consider the leaving condition for this event to be met when condition Y2-2 specified below is met. Inequality Y2-1 (entering condition): Mr-Hys>Thresh2 Inequality Y2-2 (Leaving condition): Mr+Hys <Thresh2 The variables in the formula are defined as follows: · Mr is the measurement result of the candidate L2 U2N relay UE without considering the offset. ·Hys is the hysteresis parameter for this event (i.e. the hysteresis defined in reportConfigInterRAT for this event). ·Thresh is the threshold parameter for this event (i.e., y2-Threshold-Relay defined in reportConfigInterRAT for this event). · Mr is expressed in dBm or dB depending on the measurement quantity of the candidate L2 U2N relay UE. · Hys is expressed in dB. · Thresh is expressed in the same units as Mr.

[0078] According to the 3GPP standard document TS38.331, timer T390 is defined as follows: The triggering condition for starting T390 is "when an access attempt is barred in the access barring check for the access category. The UE maintains one instance of this timer per access category". The triggering conditions for stopping T390 are "on cell (re)selection, on entering RRC_CONNECTED, on receipt of RRCReconfiguration containing reconfigurationWithSync, on change of PCell during RRC_CONNECTED, on receipt of MobilityFromNRCommand, or on receipt of RRCRelease". When T390 expires, the UE performs the actions specified in section 5.3.14.4 of TS38.331.

[0079] The embodiments of the present application aim to solve the problems in the case of L2 U2N relaying, including, for example, whether the blacklisted and whitelisted cells of the remote UE can be applied to the serving cell of the relay UE, as well as new triggering conditions for stopping timer T390 in the case of L2 U2N relaying. For example, some embodiments of the present application study the mechanism when the serving cell of the relay UE is changed after the remote UE initiates the procedure of RRCSetupRequest or RRCReestablishmentRequest, but the serving cell belongs to a different CN tracking area. Some embodiments of the present application study the mechanism when the serving cell of the relay UE is changed after the remote UE initiates the procedure of RRCResumeRequest, but the serving cell belongs to a different RAN area. Some embodiments of the present application study a new mechanism for the remote UE to determine the time point of the success of the relay handover or the success of the recovery after receiving a notification message associated with at least one indication of the relay handover or the Uu RLF of the relay UE. Some embodiments of the present application study a new case of cell change when timer T390 is running.

[0080] A more detailed description will be given in the following text in conjunction with the accompanying drawings. Those skilled in the art should be well aware that terms such as "a / the first", "a / the second" and "a / the third" are used for clarity of description only and should not be considered as substantial limitations, such as order limitations.

[0081] The following text describes specific embodiments 1-3 of the present application, in which a remote UE, a relay UE, and a network node (e.g., a BS) perform the following operations. For example, in embodiments 1-3, a remote UE, a relay UE, and a BS can function as a UE 101, a relay UE 103, and a BS 102 shown in FIG. 1, respectively.

[0082] EMBODIMENT 1 The first embodiment refers to a scenario in which the blacklisted cell and the whitelisted cell of the remote UE can be applied to the serving cell of the relay UE. In particular, in the first embodiment, the following steps may be performed: (1) Step 1: A remote UE accesses a BS through a relay UE, for example, a L2 U2N relay UE. For example, the BS may send an indication to indicate whether the L2 U2N relay UE is supported. (2) Step 2: The BS sends an RRC reconfiguration message, for example including a measurement configuration, to the remote UE. In some embodiments, the measurement configuration includes a whitelist of cells (sometimes referred to as a list of whitelisted cells, etc.) and / or a blacklist of cells (sometimes referred to as a list of blacklisted cells, etc.). Cells in the whitelist are the only cells applicable for event evaluation (e.g., Event X1, Event X2, Event Y1, and / or Event Y2 above) or measurement reporting. Cells in the blacklist are not applicable for event evaluation (e.g., Event X1, Event X2, Event Y1, and / or Event Y2) or measurement reporting. In some embodiments, the reporting configuration is a list of reporting configurations, where there is one or more reporting configurations per measurement object. Each measurement reporting configuration may include at least one of the following: 1) Report Criteria: The criteria that triggers the UE to send a measurement report, which may be periodic or a single event description. 2) Reference Signal (RS) Type: The RS (SS / PBCH (Synchronization Signal / Physical Broadcast Channel) block or CSI-RS (Channel State Information Reference Signal)) that the UE uses for beam and cell measurement results. 3) Reporting Format: The per-cell and per-beam quantities (e.g., Reference Signal Received Power (RSRP)) that the UE includes in its measurement reports, along with other associated information such as the maximum number of cells to report and the maximum number of beams per cell. (3) Step 3: The remote UE receives a discovery message from the relay UE. In some embodiments, the discovery message includes a serving cell of the relay UE. For example, a new radio cell identity (NCI) is included in the discovery message as a cell ID of the serving cell of the relay UE. (4) Step 4: The remote UE performs a measurement procedure. In different embodiments, there may be different cases as follows: - Relay UEs served by cells included in the cell blacklist (i.e. the list of blacklisted cells) may not be applicable for event evaluation or measurement reporting. - Relay UEs served by cells included in the cell whitelist (i.e. the list of whitelisted cells) may be applicable for event evaluation or measurement reporting. - Relay UEs served by cells that do not belong to either the cell blacklist or the cell whitelist may be applicable for event evaluation or measurement reporting. - Relay UEs served by cells that do not belong to either the cell blacklist or the cell whitelist may not be applicable for event evaluation or measurement reporting. (5) Step 5: The remote UE reports the measurement result when an event (eg, event X1, event X2, event Y1, or event Y2) is satisfied during the execution of the event evaluation. In different embodiments, there may be different cases as follows: - Relay UEs served by cells included in the blacklist of cells may not be included in the measurement report. - Relay UEs served by cells that are not included in both the cell blacklist and the cell whitelist may not be included in the measurement report.

[0083] EMBODIMENT 2 The second embodiment refers to a scenario in which the "time of successful relay handover or successful recovery after receiving at least one indication of relay handover or a notification message associated with the Uu RLF of the relay UE" can be known or determined. In particular, if the remote UE does not further notify the remote UE of the "success or failure" of the relay handover or recovery after receiving at least one indication of relay handover or a notification message associated with the Uu RLF of the relay UE and prioritizing maintaining the PC5 connection, the time of sending the RRC re-establishment message needs to be known or determined. In the second embodiment, the following steps can be performed. (1) Step 1: A remote UE accesses a BS through a relay UE, for example, a L2 U2N relay UE. For example, the BS may send an indication to indicate whether the L2 U2N relay UE is supported. (2) Step 2: The BS sends an RRC reconfiguration message, for example including a measurement configuration, to the remote UE. (3) Step 3: The remote UE receives at least one indication of a relay handover or a notification message associated with a Uu RLF of the relay UE. (4) Step 4: The remote UE decides to maintain the PC5 link between the remote UE and the relay UE. In some embodiments, if the remote UE decides to maintain the PC5 link, the remote UE does not send a release indication to the relay UE. (5) Step 5: After the relay UE completes the handover or recovery procedure, the relay UE sends a discovery message including a cell ID (e.g., an NCI, a cell ID, or a public land mobile network (PLMN) ID). In some embodiments, completion of the handover or recovery procedure includes, but is not limited to, successful handover, successful recovery, unsuccessful handover, and / or unsuccessful recovery. (6) Step 6: The remote UE may send an RRC re-establishment request message based on the discovery message from the relay UE. The remote UE may infer the success of the handover or the success of the recovery based on the discovery message.

[0084] EMBODIMENT 3 The third embodiment refers to a scenario that handles the case where the serving cell of the relay UE is changed after the remote UE initiates the RRCResumeRequest procedure. The third embodiment refers to a timer (e.g., T390) associated with the access barring check. In particular, in the third embodiment, the following steps may be performed: (1) Step 1: A remote UE accesses a BS via a relay UE, for example, an L2 U2N relay UE. - In some embodiments, the remote UE receives a configuration from the BS that includes one timer associated with the connection setup of the indirect path, e.g., a timer associated with the access barring check (e.g., T390). For example, the configuration may be received via an RRC reconfiguration message. In one embodiment, the configuration may be broadcast via SIB1 (System Information Block 1). For example, the configuration includes a timer value for a timer associated with the access barring check (e.g., T390). (2) Step 2: The remote UE performs an access barring check. In some embodiments, if the remote UE's access attempt is deemed barred, the remote UE shall start a timer (eg T390) associated with the access barring check for the access category. (3) After step 2, in different embodiments, there may be two cases: case 1 and case 2. In case 1, step 3 is executed. In case 2, both step 3' and step 4' are executed. a) Case 1: Step 3: The remote UE stops a timer (eg, T390) associated with the access barring check if this timer is running while at least one condition is met. 1) When relay (re)selection is performed, 2) When changing cells due to relay (re)selection, 3) During relay (re)selection and the serving cell of the selected relay is different from the current serving cell of the remote UE, or 4) Upon receipt of a notification message associated with at least one indication of relay handover, Uu RLF, or cell reselection from a relay UE. b) Case 2 - Step 3': In this step, in different embodiments there can be two options: option 1 and option 2. 1) Option 1 of step 3': If a cell change due to relay (re)selection occurs while a timer associated with the access barring check (e.g. T390) is running, the remote UE shall stop the timer associated with the access barring check (e.g. T390). 2) Option 2 of step 3': If the remote UE receives a "notification message associated to at least one of the following indications: relay handover, Uu RLF, or cell (re)selection" from the relay UE while a timer associated with the access barring check (e.g. T390) is running, the remote UE shall stop the timer associated with the access barring check (e.g. T390). - Step 4': If a timer (eg T390) associated with an access barring check corresponding to access category "2" expires or is stopped, the remote UE considers the barring of this access category relaxed. 1) If the prohibition of an access category is deemed to be relaxed, the remote UE shall notify higher layers about the relaxation of the prohibition of the access category if the higher layers have been notified that the access category is restricted.

[0085] 3 illustrates a flowchart of an example procedure 300 for wireless communication according to some embodiments of the present disclosure. Details described in all other embodiments of the present disclosure are applicable to the embodiment illustrated in FIG.

[0086] The exemplary procedure 300 refers to a scenario that handles the case where the serving cell of a relay UE is changed after a remote UE initiates an RRC setup request procedure. Referring to Figure 3, a remote UE 301, a relay UE 302, and a BS 303 may function as the UE 101, the relay UE 103, and the BS 102 shown in Figure 1, respectively. In particular, the exemplary procedure 300 includes the following steps:

[0087] In step 311, the remote UE 301 accesses the BS 303 via a relay UE 302, which is, for example, a L2 U2N relay UE. For example, the BS 303 may send an indication to indicate whether the L2 U2N relay UE is supported.

[0088] In step 312 , the BS 303 sends an RRC release message to the remote UE 301 .

[0089] In step 313, the remote UE 301 enters an RRC_IDLE state after receiving the RRC release message.

[0090] In step 314, the remote UE 301 initiates the procedure for connection establishment when higher layers request establishment of an RRC connection while the remote UE 301 is in RRC_IDLE state.

[0091] In step 315, the remote UE 301 sends an RRC SETUP REQUEST message to the BS 303 via the relay UE 302, and starts timer T300 or timer "T300-remote UE" upon sending the RRC SETUP REQUEST message.

[0092] In step 316, in different embodiments, there can be two options: option 1 and option 2. (1) In some embodiments, in option 1 of step 316, if the remote UE 301 receives a notification message including an instruction for cell (re)selection, and the (re)selected cell of the relay UE 302 belongs to a different tracking area than the current serving cell of the remote UE 301, the remote UE 301 stops the timer T300 or the timer “T300-remote UE” and performs a TAU procedure. In one embodiment, the remote UE 301 receives the ID information of the new serving cell included in the discovery message when the relay UE 302 performs a handover procedure or an RRC re-establishment procedure. (2) In some other embodiments, in option 2 of step 316, if the remote UE 301 receives a notification message including an instruction for cell (re)selection during the execution of timer T300 or timer “T300-remote UE”, and the (re)selected cell of the relay UE 302 belongs to a different tracking area than the current serving cell of the remote UE 301, then the remote UE 301 performs an RRC setup procedure instead of performing a TAU procedure.

[0093] Those skilled in the art will appreciate that the sequence of operations in the example procedure 300 of FIG. 3 may be changed, and some of the operations in the example procedure 300 of FIG. 3 may be deleted or modified without departing from the spirit and scope of the present disclosure.

[0094] 4 illustrates a flowchart of an example procedure 400 for wireless communication according to some embodiments of the present disclosure. Details described in all other embodiments of the present disclosure are applicable to the embodiment illustrated in FIG.

[0095] The exemplary procedure 400 refers to a scenario that handles the case where the serving cell of a relay UE is changed after a remote UE initiates an RRC re-establishment request procedure. Referring to Figure 4, a remote UE 401, a relay UE 402, and a BS 403 may function as the UE 101, the relay UE 103, and the BS 102 shown in Figure 1, respectively. In particular, the exemplary procedure 400 includes the following steps:

[0096] In step 411, the remote UE 401 accesses the BS 403 via a relay UE 402, which is, for example, a L2 U2N relay UE. For example, the BS 403 may send an indication to indicate whether the L2 U2N relay UE is supported.

[0097] In step 412, the BS 403 sends an RRC reconfiguration message to the remote UE 401, for example including the measurement configuration.

[0098] In step 413, the remote UE 401 initiates the RRC re-establishment procedure upon sending an RRC Re-establishment Request message, and starts timer T301 or timer "T301-remote UE".

[0099] In step 414, in different embodiments, there may be two options: option 1 and option 2. (1) In some embodiments, in option 1 of step 414, if the remote UE 401 receives a notification message including an instruction for cell (re)selection while the timer T301 or the timer “T301-remote UE” is running, and the (re)selected cell of the relay UE 402 belongs to a different tracking area than the current serving cell of the remote UE 401, the remote UE 401 stops the timer T301 or the timer “T301-remote UE” and performs a TAU procedure. In one embodiment, the remote UE 401 receives ID information of the new serving cell included in a discovery message when the relay UE 402 performs a handover procedure or an RRC re-establishment procedure. (2) In some other embodiments, in option 2 of step 414, if the remote UE 401 receives a notification message including an instruction for cell (re)selection while timer T301 or timer “T301-remote UE” is running, and the (re)selected cell of the relay UE 402 belongs to a different tracking area than the current serving cell of the remote UE 401, then the remote UE 401 performs an RRC setup procedure instead of performing a TAU procedure.

[0100] Those skilled in the art will appreciate that the sequence of operations in the example procedure 400 of FIG. 4 may be changed, and some of the operations in the example procedure 400 of FIG. 4 may be deleted or modified without departing from the spirit and scope of the present disclosure.

[0101] 5 illustrates a flowchart of an example procedure 500 for wireless communication according to some embodiments of the present disclosure. Details described in all other embodiments of the present disclosure are applicable to the embodiment illustrated in FIG.

[0102] The exemplary procedure 500 refers to a scenario that handles the case where the serving cell of a relay UE is changed after a remote UE initiates an RRC resume request procedure. Referring to Figure 5, a remote UE 501, a relay UE 502, and a BS 503 may function as the UE 101, the relay UE 103, and the BS 102 shown in Figure 1, respectively. In particular, the exemplary procedure 500 includes the following steps:

[0103] In step 511, the remote UE 501 accesses the BS 503 via a relay UE 502, which is, for example, a L2 U2N relay UE. For example, the BS 503 may send an indication to indicate whether the L2 U2N relay UE is supported.

[0104] In step 512, the BS 503 sends an RRC release message to the remote UE 501, for example including a suspend indication.

[0105] In step 513, the remote UE 501 enters the RRC_INACTIVE state after receiving the RRC release message.

[0106] In step 514, the remote UE 501 initiates an RRC resumption procedure.

[0107] In step 515, the remote UE 501 sends an RRC Resume Request message and starts timer T319 or timer "T319-remote UE" upon sending the RRC Resume Request message.

[0108] In step 516, in different embodiments, there may be two options: option 1 and option 2.

[0109] (1) In some embodiments, in option 1 of step 516, if the remote UE 501 in RRC_INACTIVE state receives a notification message including an instruction for cell (re)selection while timer T319 or timer "T319-remote UE" is running, and the (re)selected cell of the relay UE 502 belongs to a different notification area than the current serving cell of the remote UE 501, then the remote UE 501 stops timer T319 or timer "T319-remote UE" and performs the RNAU procedure. In an embodiment of option 1 of step 516, the RRC Resume Request message includes a resume cause (e.g., ResumeCause) associated with the RNAU procedure. For example, the ResumeCause in the RRC Resume Request message may be set to "rna-Update". In another embodiment of option 1 of step 516, the RRC Resume Request message includes a resume cause (e.g., ResumeCause) associated with the transmission of data or signaling. For example, the ResumeCause in the RRC Resume Request message can be set to any of "mo-Signalling, mo-Data, mo-VoiceCall, mo-VideoCall, and / or mo-SMS". (2) In some embodiments, in option 2 of step 516, if the remote UE 501 receives a notification message including an instruction for cell (re)selection while timer T319 or timer "T319-remote UE" is running, and the (re)selected cell of the relay UE belongs to a different tracking area than the current serving cell of the remote UE 501, the remote UE 501 performs an RRC resumption procedure instead of performing an RNAU procedure. In an embodiment of option 2 of step 516, the RRC Resume Request message includes a resume cause (e.g., ResumeCause) associated with the transmission of data or signaling. For example, the ResumeCause in the RRC Resume Request message can be set to any of "mo-Signalling, mo-Data, mo-VoiceCall, mo-VideoCall, and / or mo-SMS".

[0110] Those skilled in the art will appreciate that the sequence of operations in the example procedure 500 of FIG. 5 may be changed, and some of the operations in the example procedure 500 of FIG. 5 may be deleted or modified without departing from the spirit and scope of the present disclosure.

[0111] Some embodiments of the present application also provide a wireless communication device in a case of L2 U2N relay. For example, FIG. 6 shows an example block diagram of a device 600 in a case of L2 U2N relay according to some embodiments of the present application.

[0112] 6, the apparatus 600 may include at least one non-transitory computer-readable medium 602, at least one receiving circuit 604, at least one transmitting circuit 606, and at least one processor 608 coupled to the non-transitory computer-readable medium 602, the receiving circuit 604, and the transmitting circuit 606. The at least one processor 608 may be a CPU, a DSP, a microprocessor, etc. The apparatus 600 may be a network device (e.g., a BS) or a UE (e.g., a remote UE or a relay UE) configured to perform methods, such as those illustrated above.

[0113] In this drawing, elements such as at least one processor 608, the receiving circuitry 604, and the transmitting circuitry 606 are described in the singular, but the plural is contemplated unless limitation to the singular is explicitly stated. In some embodiments of the present application, the receiving circuitry 604 and the transmitting circuitry 606 may be combined into a single device, such as a transceiver. In certain embodiments of the present application, the apparatus 600 may further include an input device, a memory, and / or other components.

[0114] In some embodiments of the present application, the non-transitory computer-readable medium 602 may store computer-executable instructions that cause the processor to implement a method for a remote UE, a relay UE, or a network device (e.g., a BS), as described above. For example, the computer-executable instructions, when executed, cause the processor 608 to interact with the receiving circuitry 604 and the transmitting circuitry 606 to perform steps for a remote UE, a relay UE, or a network device (e.g., a BS), as shown above.

[0115] FIG. 7 illustrates a further exemplary block diagram of an apparatus 700 in a L2 U2N relay case, according to some embodiments of the present application.

[0116] 7, an apparatus 700, e.g., a BS or a UE, may include at least one processor 702 and at least one transceiver 704 coupled to the at least one processor 702. The transceiver 704 may include at least one separate receiving circuit 706 and transmitting circuit 708, or at least one integrated receiving circuit 706 and transmitting circuit 708. The at least one processor 702 may be a CPU, DSP, microprocessor, etc.

[0117] According to some other embodiments of the present application, when the apparatus 700 is a remote UE, the processor 702 may be configured to access a serving cell via the relay UE and receive an RRC message from the serving cell via the transceiver 704, the RRC message including at least one of an RRC reconfiguration message or an RRC release message.

[0118] According to some embodiments of the present application, when the apparatus 700 is a BS, the processor 702 is configured to transmit, via the transceiver 704, a measurement configuration to a remote user equipment (UE) via a relay UE, where the remote UE communicates with a serving cell of the network node via the relay UE, and the measurement configuration includes at least one of a blacklist of cells, where each cell in the blacklist of cells is not applicable for the event evaluation or measurement procedure, or a whitelist of cells, where each cell in the whitelist of cells is applicable for the event evaluation or measurement procedure.

[0119] According to some embodiments of the present application, when the apparatus 700 is a relay UE, the processor 702 is configured to: access a serving cell, where the remote UE communicates with the serving cell via the relay UE; perform a handover procedure or declare an RLF on a Uu link of the relay UE; and send a notification message associated with an indication of at least one of the handover procedure or the RLF on the Uu link of the relay UE.

[0120] The methods of the present disclosure can be implemented on a programmed processor. However, the controllers, flowcharts, and modules can also be implemented on hardware electronic or logical circuits, such as general-purpose or special-purpose computers, programmed microprocessors or microcontrollers and peripheral integrated circuit elements, integrated circuits, discrete element circuits, programmable logic devices, etc. In general, any device having a finite state machine capable of implementing the flowcharts shown in the figures can be used to implement the processing functions of the present disclosure.

[0121] Although the present disclosure has been described with its specific embodiments, it is apparent that many alternatives, modifications, and variations may be apparent to those skilled in the art. For example, various components of the embodiments may be exchanged, added, or substituted in other embodiments. Also, not all elements of each drawing are necessary for the operation of the disclosed embodiments. For example, a person skilled in the art could make and use the teachings of the present disclosure by simply adopting the elements of the independent claims. Thus, the embodiments of the present disclosure described herein are illustrative and not intended to be limiting. Various changes may be made without departing from the spirit and scope of the present disclosure.

[0122] As used herein, the terms "includes," "including," or other variations thereof are intended to cover a non-exclusive inclusion, and thus a process, method, article, or apparatus that includes a list of elements does not include only those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element preceded by "a," "an," etc., does not preclude the presence of additional identical elements in a process, method, article, or apparatus that includes the element, unless further constrained. Also, the term "another" is defined as at least a second or more. As used herein, terms such as "having" are defined as "including." [Explanation of symbols]

[0123] 100 Wireless communication system 101UE 102 BS 103 Relay UE 300 Steps 301 Remote UE 302 Relay UE 303BS 400 Steps 401 Remote UE 402 Relay UE 403BS 500 steps 501 Remote UE 502 Relay UE 503 BS 600 equipment 602 Non-transitory computer-readable medium 604 Receiving circuit 606 Transmitting Circuit 608 Processor 700 equipment 702 Processor 704 Transceiver 706 Receiving circuit 708 Transmitting Circuit

Claims

1. A processor; a transceiver coupled to the processor; Equipped with The processor, accessing the serving cell via a relay UE; receiving a radio resource control (RRC) message from the serving cell via the transceiver; and the RRC message is configured to: An RRC reconfiguration message, or RRC Release Message A user equipment (UE) including at least one of:

2. In response to the RRC message including the RRC reconfiguration message, the RRC reconfiguration message includes a measurement configuration, the measurement configuration comprising: a blacklist of cells, each cell in said blacklist of cells being not applicable for event evaluation or measurement procedures; or a whitelist of cells, each cell in the whitelist of cells being applicable to the event evaluation or measurement procedure; The UE of claim 1 , comprising at least one of:

3. In response to the serving cell of the relay UE belonging to the blacklist, the relay UE is not applicable to the event evaluation or measurement procedure; or The UE of claim 2 , wherein in response to the serving cell of the relay UE belonging to the whitelist, the relay UE is applicable to the event evaluation or the measurement procedure.

4. In response to the serving cell of the relay UE not belonging to either the blacklist or the whitelist, The relay UE is not applicable to the event evaluation or measurement procedure, or The UE of claim 2 , wherein the relay UE is applicable to the event evaluation or the measurement procedure.

5. 5. The UE of claim 3 or 4, wherein the processor of the UE is configured to report a measurement result when an event associated with the relay UE is satisfied during execution of the event evaluation in response to the relay UE being applicable to the event evaluation or the measurement procedure.

6. The event associated with the relay UE: the relay UE becomes worse than a first threshold and a second cell becomes better than a second threshold; the relay UE becomes worse than a third threshold; the relay UE becomes worse than a fourth threshold and the candidate relay UE becomes better than a fifth threshold; or The candidate relay UE is better than a sixth threshold. The UE of claim 5, comprising one of:

7. The processor of the UE, entering an RRC idle state in response to the RRC message including the RRC release message; initiating an RRC setup request procedure; transmitting the RRC setup request message starts a timer associated with the RRC setup request; The UE of claim 1 , configured to:

8. The UE of claim 7, wherein the processor of the UE is configured to perform a unified access control procedure in response to initiation of the RRC setup request procedure.

9. 10. The UE of claim 8, wherein the processor of the UE is configured to start a timer associated with an access barring check in response to an access attempt of the UE being considered barred.

10. the processor of the UE in response to the timer associated with an access barring check being running; and Relay selection or reselection, Changing the serving cell due to the relay selection or relay reselection; Relay reselection, and a second serving cell of the selected relay UE is different from the serving cell of the UE; or receiving, from the relay UE, a notification message associated with an indication of at least one of a handover of the relay UE, a radio link failure (RLF) on a Uu link of the relay UE, or a cell reselection of the relay UE; 10. The UE of claim 9, configured to stop the timer associated with an access barring check in response to satisfying at least one of:

11. The processor of the UE, in response to receiving a notification message including an indication of cell reselection from the relay UE, and in response to the reselected cell and the serving cell belonging to different tracking areas; in response to the timer associated with an RRC setup request being running, stopping the timer associated with an RRC setup request and performing a Tracking Area Update (TAU) procedure; or Performing the RRC setup procedure The UE of claim 7, configured to:

12. The processor of the UE, initiating an RRC re-establishment procedure in response to receiving a notification message associated with a declaration of a Radio Link Failure (RLF) or an indication of at least one of a handover of the relay UE or an RLF on a Uu link of the relay UE; sending an RRC re-establishment request message; starting a timer associated with the RRC re-establishment request; The UE of claim 1 , configured to:

13. The processor of the UE, in response to receiving a notification message including an indication of cell reselection from the relay UE, and in response to the reselected cell and the serving cell belonging to different tracking areas; in response to the timer associated with an RRC re-establishment request being running, stopping the timer associated with an RRC re-establishment request and performing a Tracking Area Update (TAU) procedure; or Performing the RRC re-establishment procedure The UE of claim 12, configured to:

14. The processor of the UE, entering an RRC inactive state in response to the RRC message including the RRC Release message and in response to the RRC Release message including a suspend indication; sending an RRC resume request message; starting a timer associated with the RRC resume request; The UE of claim 1 , configured to:

15. The processor of the UE, in response to receiving a notification message including an indication of cell reselection from the relay UE, and in response to the reselected cell and the serving cell belonging to different radio access network-based notification areas (RNAs), in response to the timer associated with an RRC restart request being running, stopping the timer associated with an RRC restart request and performing a Radio Access Network based Notification Area Update (RNAU) procedure; or Performing the RRC restart procedure The UE of claim 14, configured to:

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