Method and apparatus for timers and operations in an L2 U2N relay case

Abstract

An embodiment of the present application relates to a method and apparatus for conditions and operations associated with several timers in a Layer 2 (L2) UE-to-Network (U2N) relay case. According to one 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 from the serving cell via the transceiver configuration information associated with at least one of a timer associated with a Radio Resource Control (RRC) setup request, a timer associated with an RRC re-establishment request, a timer associated with an RRC resume request, or a timer associated with receiving an RRC release or an RRC reject. When at least one timer is started, the UE shall stop the timer based on a relay-related condition.

Description

[Technical field]

[0001] FIELD Embodiments of the present application generally relate to wireless communication technologies, and more particularly, to methods and apparatus for conditions and operations associated with certain timers in a Layer 2 (L2) UE-to-Network (U2N) relay case. [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, without the need for data to pass through a base station (BS) or core network.

[0003] The Third Generation Partnership Project (3GPP) 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 experience relatively poor signal quality. RNs are also sometimes referred to as relay UEs. A 3GPP 5G sidelink system that includes 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 conditions and operations associated with some timers in the case of L2 U2N relaying in 3GPP 5G 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] IEEE802.11 Family [Non-Patent Document 4] 3GPP 5G Protocols [Non-Patent Document 5] 3GPP standard document TS38.331 [Non-Patent Document 6] Section 5.3.3.7 of TS38.331 [Non-Patent Document 7] Section 5.3.14.4 of TS38.331 [Non-Patent Document 8] Section 5.3.13.5 of TS38.331 Summary of the Invention [Means for solving the problem]

[0006] Some embodiments of the present application provide a user equipment (UE), including a processor and a transceiver coupled to the processor, the processor being configured to access a serving cell via a relay UE, and receive from the serving cell via the transceiver configuration information associated with at least one of a radio resource control (RRC) setup request, a timer associated with an RRC re-establishment request, a timer associated with an RRC resume request, or a timer associated with receiving an RRC release or an RRC reject.

[0007] In some embodiments, the processor of the UE is configured to, in response to transmitting the RRC setup request message, start a timer associated with the RRC setup request.

[0008] In some embodiments, the processor of the UE is configured to stop a timer associated with the RRC setup request in response to satisfying at least one of: when receiving a first notification from the relay UE associated with 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; when declaring a sidelink RLF on a link between the UE and the relay UE; when determining that the relay UE has become unsuitable; or when upon relay selection or relay reselection, when determining that the selected relay UE or the reselected relay UE has become unsuitable.

[0009] In some embodiments, in response to expiration of a timer associated with the RRC setup request, the processor of the UE is configured to transmit information to higher layers of the UE indicating at least one of a failure to establish an RRC connection, a sidelink RLF on a link between the UE and the relay UE, an RLF on a Uu link of the relay UE, receipt of a notification of a relay UE handover, the UE determining that a relay UE has become unsuitable, a relay selection or a relay reselection, or the UE determining that a selected or reselected relay UE has become unsuitable.

[0010] In some embodiments, the processor of the UE is configured to, in response to transmitting the RRC re-establishment request message, start a timer associated with the RRC re-establishment request.

[0011] In some embodiments, the processor of the UE is configured to stop a timer associated with the RRC re-establishment request in response to satisfying at least one of: when receiving a first notification from the relay UE associated with 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; when declaring a sidelink RLF on a link between the UE and the relay UE; the UE determining that the relay UE has become unsuitable; upon relay selection or relay reselection; or the UE determining that the selected or reselected relay UE has become unsuitable.

[0012] In some embodiments, the processor of the UE is configured to determine that the relay UE has become unsuitable or to determine that the selected relay UE or the reselected relay UE has become unsuitable in response to at least one of receiving a first notification from the relay UE, receiving a second notification from the relay UE associated with at least one of a handover failure of the relay UE or a recovery failure on the Uu link of the relay UE, declaring a sidelink RLF on a link between the UE and the relay UE, a channel quality of the link between the UE and the relay UE being below a first threshold, declaring a sidelink RLF on a link between the UE and the selected relay UE or the reselected relay UE, or a channel quality of the link between the UE and the selected relay UE or the reselected relay UE being below a second threshold.

[0013] In some embodiments, the processor of the UE is configured to, in response to transmitting the RRC resume request message, start a timer associated with the RRC resume request.

[0014] In some embodiments, the processor of the UE is configured to continue at least one of measurements related to relay selection or relay reselection or evaluations related to relay selection or relay reselection, and to perform relay selection or relay reselection in response to a condition for relay selection or relay reselection being satisfied.

[0015] In some embodiments, the processor of the UE is configured to stop a timer associated with the RRC resumption request in response to satisfying at least one of: when receiving from the relay UE a first notification associated with 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; when receiving from the relay UE a second notification associated with at least one of a handover failure of the relay UE, or a recovery failure on a Uu link of the relay UE; or when declaring a sidelink RLF on a link between the UE and the relay UE.

[0016] In some embodiments, the processor of the UE is configured to enter the RRC idle state in response to a timer associated with an RRC resumption request being running and in response to receiving a notification from the relay UE that a second serving cell of the selected relay UE or the reselected relay UE is different from the serving cell of the UE at the time of relay selection or relay reselection, or associated with 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.

[0017] In some embodiments, the processor of the UE is configured to start a timer associated with receiving an RRC release or an RRC reject in response to transmitting the RRC resume request message.

[0018] In some embodiments, the processor of the UE is configured to stop a timer associated with receiving an RRC release or an RRC reject in response to satisfying at least one of the following: upon relay selection or upon relay reselection, a second serving cell of the selected relay UE or the reselected relay UE being different from the serving cell of the UE, or upon receiving a notification from the relay UE associated with 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.

[0019] In some embodiments, the processor of the UE is configured to enter the RRC idle state in response to a timer running that is associated with receiving an RRC release or an RRC reject, and a second serving cell of the selected relay UE or the reselected relay UE that is different from the serving cell of the UE at the time of relay selection or relay reselection, or receiving a notification from the relay UE that is associated with 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.

[0020] 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 is configured to access a serving cell, where a remote UE communicates with the serving cell via the relay UE, and receive from the serving cell via the transceiver configuration information associated with at least one of a radio resource control (RRC) setup request, a timer associated with an RRC re-establishment request, a timer associated with an RRC resume request, or a timer associated with receiving an RRC release or an RRC reject.

[0021] In some embodiments, the processor of the relay UE is configured to receive, via the transceiver, from the serving cell, a channel quality threshold for a link between the UE and the relay UE, and to transmit, via the transceiver, the channel quality threshold to the UE.

[0022] In some embodiments, the processor of the relay UE is configured to send, via the transceiver, to the UE a first notification associated with 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.

[0023] In some embodiments, the processor of the relay UE is configured to send, via the transceiver, to the UE, a second notification associated with at least one of a handover failure of the relay UE or a recovery failure on the Uu link of the relay UE.

[0024] In some embodiments, the processor of the relay UE is configured to transmit, via the transceiver to the UE, an identifier (ID) of the second serving cell of the selected relay UE or the reselected relay UE in response to the second serving cell being different from the serving cell of the UE upon relay selection or relay reselection.

[0025] Some embodiments of the present application provide a network node (e.g., BS), including a processor and a transceiver coupled to the processor, configured to transmit, via the transceiver, to a user equipment (UE) via a relay UE, configuration information associated with at least one of a radio resource control (RRC) setup request, a timer associated with an RRC re-establishment request, a timer associated with an RRC resume request, or a timer associated with receiving an RRC release or an RRC reject.

[0026] In some embodiments, the processor of the network node is configured to transmit, via the transceiver, to the UE via the relay UE, a channel quality threshold of a link between the UE and the relay UE.

[0027] 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, from the serving cell, configuration information associated with at least one of a timer associated with a Radio Resource Control (RRC) setup request, a timer associated with an RRC re-establishment request, a timer associated with an RRC resume request, or a timer associated with receiving an RRC release or an RRC reject.

[0028] In some embodiments, the method further comprises starting a timer associated with the RRC setup request in response to transmitting the RRC setup request message.

[0029] In some embodiments, the method further comprises stopping a timer associated with the RRC setup request in response to at least one of: receiving from the relay UE a first notification associated with 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; declaring a sidelink RLF on a link between the UE and the relay UE; the UE determining that the relay UE has become unsuitable; upon relay selection or upon relay reselection; or the UE determining that the selected or reselected relay UE has become unsuitable.

[0030] In some embodiments, the method further comprises, in response to expiry of a timer associated with the RRC setup request, transmitting to higher layers in the UE information indicating at least one of: failure to establish an RRC connection, a sidelink RLF on a link between the UE and the relay UE, an RLF on a Uu link of the relay UE, receipt of a notification of a relay UE handover, the UE determining that a relay UE has become unsuitable, a relay selection or a relay reselection, or the UE determining that a selected or reselected relay UE has become unsuitable.

[0031] In some embodiments, the method further comprises starting a timer associated with the RRC re-establishment request in response to transmitting the RRC re-establishment request message.

[0032] In some embodiments, the method further comprises stopping a timer associated with the RRC re-establishment request in response to satisfying at least one of: when receiving a first notification from the relay UE associated with 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; when declaring a sidelink RLF on a link between the UE and the relay UE; when determining that the relay UE has become unsuitable; upon relay selection or relay reselection; or when determining that the selected or reselected relay UE has become unsuitable.

[0033] In some embodiments, the method further comprises the steps of receiving a first notification from the relay UE, receiving a second notification from the relay UE associated with at least one of a handover failure of the relay UE or a recovery failure on the Uu link of the relay UE, declaring a sidelink RLF on a link between the UE and the relay UE, and determining that the relay UE has become unsuitable in response to at least one of a channel quality of the link between the UE and the relay UE being below a first threshold, declaring a sidelink RLF on a link between the UE and the selected or reselected relay UE, or a channel quality of the link between the UE and the selected or reselected relay UE being below a second threshold, or determining that the selected or reselected relay UE has become unsuitable.

[0034] In some embodiments, the method further comprises starting a timer associated with the RRC resume request in response to transmitting the RRC resume request message.

[0035] In some embodiments, the method further comprises continuing at least one of measurements related to relay selection or relay reselection or evaluations related to relay selection or relay reselection, and performing relay selection or relay reselection in response to a condition for relay selection or relay reselection being satisfied.

[0036] In some embodiments, the method further comprises stopping a timer associated with the RRC resumption request in response to at least one of: receiving from the relay UE a first notification associated with 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; receiving from the relay UE a second notification associated with at least one of a handover failure of the relay UE, or a recovery failure on a Uu link of the relay UE; or declaring a sidelink RLF on a link between the UE and the relay UE.

[0037] In some embodiments, the method is configured to enter an RRC idle state in response to a timer associated with an RRC resumption request running and in response to receiving a notification from the relay UE that a second serving cell of the selected or reselected relay UE is different from the serving cell of the UE at the time of relay selection or relay reselection, or associated with 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.

[0038] In some embodiments, the method further comprises starting a timer associated with receiving an RRC release or an RRC reject in response to transmitting the RRC resume request message.

[0039] In some embodiments, the method further comprises stopping a timer associated with receiving an RRC release or an RRC reject in response to at least one of: upon relay selection or upon relay reselection, a second serving cell of the selected or reselected relay UE being different from the serving cell of the UE, or upon receiving a notification from the relay UE associated with 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.

[0040] In some embodiments, the method further comprises entering an RRC idle state in response to a timer running that is associated with receiving an RRC release or an RRC reject and that a second serving cell of the selected or reselected relay UE is different from the serving cell of the UE at the time of relay selection or relay reselection, or receiving from the relay UE a notification associated with 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.

[0041] Some embodiments of the present application provide a method that may be performed by a relay UE, the method including: accessing a serving cell, where a remote UE communicates with the serving cell via the relay UE, and receiving, from the serving cell, configuration information associated with at least one of a Radio Resource Control (RRC) setup request, a timer associated with an RRC re-establishment request, a timer associated with an RRC resume request, or a timer associated with receiving an RRC release or an RRC reject.

[0042] In some embodiments, the method comprises receiving a channel quality threshold for a link between the UE and a relay UE from a serving cell, and transmitting the channel quality threshold to the UE.

[0043] In some embodiments, the method further comprises sending, to the UE, a first notification associated with 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.

[0044] In some embodiments, the method further comprises sending, to the UE, a second notification associated with at least one of a handover failure of the relay UE or a recovery failure on the Uu link of the relay UE.

[0045] In some embodiments, the method further comprises transmitting, to the UE, an identifier (ID) of the second serving cell of the selected relay UE or the reselected relay UE in response to the second serving cell being different from the serving cell of the UE upon relay selection or relay reselection.

[0046] Some embodiments of the present application provide a method that may be performed by a network node (e.g., a BS), comprising transmitting, via a relay UE to a user equipment (UE), configuration information associated with at least one of a timer associated with a Radio Resource Control (RRC) setup request, a timer associated with an RRC re-establishment request, a timer associated with an RRC resume request, or a timer associated with receiving an RRC release or an RRC reject.

[0047] In some embodiments, the method further comprises transmitting, via the relay UE, to the UE, a channel quality threshold for a link between the UE and the relay UE.

[0048] 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).

[0049] 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.

[0050] 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]

[0051] [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. [Figure 5A] 4 is a flowchart of two example procedures for wireless communication according to some embodiments of the present disclosure. [Figure 5B] 4 is a flowchart of two example procedures for wireless communication according to some embodiments of the present disclosure. [Figure 6A] 4 is a flowchart of two example procedures for wireless communication according to some embodiments of the present disclosure. [Figure 6B] 4 is a flowchart of two example procedures for wireless communication according to some embodiments of the present disclosure. [Figure 7] 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 8] 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

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] In some embodiments of the present application, the BS 102 may communicate using other communication protocols, such as the IEEE 802.11 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.

[0063] 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.

[0064] 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).

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] According to the 3GPP standard document TS38.331, timers T300, T301, T302, and T319 are defined as follows: (1) Timer T300: The trigger condition for starting T300 is "upon transmission of RRCSetupRequest". The trigger condition for stopping T300 is "upon reception of RRCSetup or RRCReject message, on cell reselection, and on abort of connection establishment by higher layers". When T300 expires, the UE performs the actions specified in section 5.3.3.7 of TS38.331. (2) Timer T301: The trigger condition for starting T301 is "when an RRCReestablishmentRequest is sent". The trigger condition for stopping T301 is "when an RRCReestablishment or RRCSetup message is received, and when the selected cell becomes unsuitable". When T301 ends, the UE enters the RRC_IDLE state. (3) Timer T302: The triggering conditions for starting T302 are "upon receipt of RRCReject during RRC connection establishment or resumption, upon receipt of RRCRelease with waitTime". The triggering conditions for stopping T302 are "upon entering RRC_CONNECTED or RRC_IDLE, upon cell reselection, and upon receipt of an RRCReject message". Upon expiration of T302, the UE shall notify higher layers of the prohibition relaxation as specified in section 5.3.14.4 of TS38.331. (4) Timer T319: The triggering condition for starting T319 is "sending RRCResumeRequest or RRCResumeRequest1". The triggering conditions for stopping T319 are "receiving RRCResume, RRCSetup, RRCRelease, suspendConfig or RRCRelease with RRCReject message, cell reselection and aborting of connection establishment by higher layers". When T319 expires, the UE performs the actions specified in section 5.3.13.5 of TS 38.331.

[0070] The embodiments of the present application aim to solve the problem in the case of L2 U2N relaying, including new triggering conditions for stopping timer T300, timer T301, timer T302, and / or timer T319 in the case of L2 U2N relaying. For example, some embodiments of the present application study a new case of cell change when timer T319 or timer T302 is running.

[0071] 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.

[0072] 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.

[0073] The exemplary procedure 300 refers to a timer (marked as "Timer T1" for simplicity) associated with an RRC setup request (e.g., T300). With reference 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:

[0074] In step 311, a remote UE 301 accesses a BS 303 via a relay UE 302, which may be, for example, a Layer 2 UE-to-Network (L2 U2N) relay UE.

[0075] In step 312, the remote UE 301 receives a configuration from the BS 303, e.g., via an RRCReconfiguration message, including a timer T1 associated with the RRC setup request (e.g., T300). In some embodiments, the configuration may be broadcast via SIB1. For example, the configuration includes a timer value for timer T1.

[0076] In step 313 , the BS 303 sends a RRCRelease message to the remote UE 301 .

[0077] In step 314, the remote UE 301 enters the RRC_IDLE state after receiving the RRCRelease message.

[0078] In step 315, the remote UE 301 initiates a procedure for RRC connection establishment when the upper layers of the remote UE 301 request establishment of an RRC connection while the remote UE 301 is in an RRC_IDLE state. In some embodiments, the remote UE 301 transmits an RRCSetupRequest message. For example, the RRCSetupRequest message includes an identifier (ID) of the remote UE 301 and / or an establishment cause (e.g., mt-Access, mo-Signalling, mo-Data, mo-VoiceCall, and / or mo-VideoCall).

[0079] In some embodiments, in step 315, the remote UE 301 has acquired the required system information. In some embodiments, the remote UE 301 shall start a timer T1 (e.g., T300) when sending the RRCSetupRequest message. In some embodiments, the remote UE 301 may continue relay (re)selection related measurements and / or relay (re)selection related evaluations. If the conditions for relay (re)selection are met, the remote UE 301 shall perform relay (re)selection.

[0080] In step 316, there may be different cases, as follows:

[0081] In particular, in some embodiments of step 316, the remote UE 301 stops the timer T1 (eg, T300) when at least one of the following conditions is met: (1) When an RRCSetup message or an RRCReject message is received, when a relay UE 302 reselects a cell, and when a connection establishment is aborted by higher layers of a remote UE 301. (2) Upon receiving a notification from the relay UE 302 associated with at least one of a handover of the relay UE 302, an RLF on a Uu link of the relay UE 302, or a cell reselection of the relay UE 302. For example, the Uu link is between the relay UE 302 and the BS 303, e.g., the Uu link shown in FIG. (3) When declaring a sidelink RLF on a link between the remote UE 301 and the relay UE 302, for example the PC5 link shown in FIG. 1 . (4) When it is determined that the relay UE 302 has become unsuitable. (5) When broadcasting (re)selected. (6) When it is determined that the (re)selected relay UE (eg, another relay UE different from relay UE 302) has become unsuitable.

[0082] In some other embodiments of step 316, when timer T1 (eg, T300) expires, the remote UE 301 notifies the upper layer with information indicating at least one of the following: (1) Failure to establish an RRC connection; (2) Sidelink RLF on the link between remote UE 301 and relay UE 302; (3) RLF on the Uu link of relay UE 302; (4) Receiving a handover notification from the relay UE 302; (5) The remote UE 301 determines that the relay UE 302 has become unsuitable; (6) Relay (re)selection, or (7) The remote UE 301 determines that the (re)selected relay UE has become unsuitable.

[0083] In some embodiments, the remote UE 301 determines that the relay UE 302 has become unsuitable or determines that the (re)selected relay UE (e.g., another relay UE different from the relay UE 302) has become unsuitable in response to at least one of the following events: (1) receiving a notification from the relay UE 302 associated with at least one of a handover of the relay UE 302, an RLF on a Uu link of the relay UE 302, or a cell reselection of the relay UE 302; (2) receiving a notification from the relay UE 302 associated with at least one of a handover failure of the relay UE 302 or a recovery failure on the Uu link of the relay UE 302; (3) Declare a sidelink RLF on a link between the remote UE 301 and the relay UE 302, e.g., the PC5 link shown in FIG. 1 ; (4) the channel quality of the link between the remote UE 301 and the relay UE 302 is below a threshold; (5) Declaring a sidelink RLF on the link between the remote UE 301 and the (re)selected relay UE; or (6) The channel quality of the link between the remote UE 301 and the (re)selected relay UE is below a threshold.

[0084] In some embodiments of the present disclosure, the triggering conditions for stopping timer T300 may be defined, for example, in a standard document as follows: "upon receipt of an RRCSetup or RRCReject message, upon cell reselection, the (re)selected L2 UE-to-Network (U2N) relaying UE becomes unsuitable upon abort of connection establishment by higher layers, upon receipt of relay handover indication, Uu RLF, and / or cell reselection, upon receipt of relay handover failure and / or Uu recovery failure indication, when declaring sidelink RLF, and when the sidelink channel quality is below one threshold."

[0085] In some embodiments of the present disclosure, the definition of "the (re)selected L2 U2N relay UE becomes unsuitable" includes at least one of the following events: (1) receiving a notification from a relay UE associated with at least one of a handover of the relay UE, an RLF on a Uu link of the relay UE, or a cell reselection of the relay UE; (2) receiving a notification from the relay UE associated with at least one of a handover failure of the relay UE or a recovery failure on a Uu link of the relay UE; (3) declaring a sidelink RLF on a link between the UE and a relay UE; (4) the channel quality of the link between the UE and the relay UE is less than a threshold; (5) declaring a sidelink RLF on a link between the UE and the (re)selected relay UE; or (6) The channel quality of the link between the UE and the (re)selected relay UE is below a threshold.

[0086] 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.

[0087] 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.

[0088] The exemplary procedure 400 refers to a timer (marked as "Timer T2" for simplicity) associated with an RRC re-establishment request (e.g., T301). With reference 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:

[0089] In step 411, a remote UE 401 accesses a BS 403 via a relay UE 402, which is, for example, a L2 U2N relay UE.

[0090] In step 412, the remote UE 401 receives a configuration from the BS 403, e.g., via an RRCReconfiguration message, including a timer T2 associated with the RRC re-establishment request (e.g., T301). In some embodiments, the configuration may be broadcast via SIB1. For example, the configuration includes a timer value for the timer T2.

[0091] In step 413, the remote UE 401 in RRC_CONNECTED state initiates an RRC re-establishment procedure when at least one of the following conditions is met: (1) The remote UE 401 declares a sidelink RLF on a link between the remote UE 401 and the relay UE 402, for example, the PC5 link shown in FIG. 1 ; or (2) The remote UE 401 receives, from the relay UE 402, a notification associated with at least one of a handover of the relay UE 402, an RLF on a Uu link of the relay UE 402, or a cell reselection of the relay UE 402. The Uu link of the relay UE 402 is between the relay UE 402 and the BS 403, e.g., the Uu link shown in FIG.

[0092] In some embodiments, the remote UE 401 shall start timer T311 at the start of the RRC re-establishment procedure.

[0093] Upon selecting a suitable cell or a suitable relay UE in step 414, the remote UE 401 shall stop timer T311 and send an RRCReestablishmentRequest message. In some embodiments, the remote UE 401 may start timer T2 (e.g., T301) upon sending the RRCReestablishmentRequest message.

[0094] In step 415, the remote UE 401 stops the timer T2 (eg, T301) when at least one of the following conditions is met: (1) The remote UE 401 receives, from the relay UE 402, a notification associated with at least one of a handover of the relay UE 402, an RLF on a Uu link (between the relay UE 402 and the BS 403, e.g., the Uu link shown in FIG. 1 ) of the relay UE 402, or a cell reselection of the relay UE 402; (2) The remote UE 401 declares a sidelink RLF on a link between the remote UE 401 and the relay UE 402, for example, the PC5 link shown in FIG. 1; (3) The remote UE 401 determines that the relay UE 402 has become unsuitable; (4) When a relay is (re)selected, or (5) The remote UE 401 determines that the (re)selected relay UE (e.g., another relay UE different from the relay UE 402) has become unsuitable.

[0095] In some embodiments, the remote UE 401 determines that the relay UE 402 has become unsuitable or determines that the (re)selected relay UE (e.g., another relay UE different from the relay UE 402) has become unsuitable in response to at least one of the following events: (1) receiving a notification from a relay UE 402 associated with at least one of a handover of the relay UE 402, an RLF on a Uu link of the relay UE 402, or a cell reselection of the relay UE 402; (2) receiving a notification from the relay UE 402 associated with at least one of a handover failure of the relay UE 402 or a recovery failure on a Uu link of the relay UE 402; (3) Declare a sidelink RLF on a link between the remote UE 401 and the relay UE 402, e.g., the PC5 link shown in FIG. 1; (4) the channel quality of the link between the remote UE 401 and the relay UE 402 is below a threshold; (5) Declaring a sidelink RLF on the link between the remote UE 401 and the (re)selected relay UE; (6) The channel quality of the link between the remote UE 401 and the (re)selected relay UE is below a threshold.

[0096] In some embodiments of the present disclosure, the triggering conditions for stopping timer T301 may be defined, for example, in a standard document as follows: "upon receipt of an RRCReestablishment message or an RRCSetup message, and when the selected cell becomes unsuitable or the (re)selected L2 U2N relay UE becomes unsuitable, upon receipt of a relay handover indication, a Uu RLF, and / or a cell reselection, upon receipt of a relay handover failure and / or a Uu recovery failure indication, upon declaring a sidelink RLF, and when the sidelink channel quality becomes unsuitable below one threshold."

[0097] In some embodiments of the present disclosure, the definition of "the (re)selected L2 U2N relay UE becomes unsuitable" includes at least one of the following events: (1) receiving a notification from a relay UE associated with at least one of a handover of the relay UE, an RLF on a Uu link of the relay UE, or a cell reselection of the relay UE; (2) receiving a notification from the relay UE associated with at least one of a handover failure of the relay UE or a recovery failure on a Uu link of the relay UE; (3) declaring a sidelink RLF on a link between the UE and a relay UE; (4) the channel quality of the link between the UE and the relay UE is less than a threshold; (5) declaring a sidelink RLF on a link between the UE and the (re)selected relay UE; or (6) The channel quality of the link between the UE and the (re)selected relay UE is below a threshold.

[0098] 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.

[0099] 5A and 5B are flowcharts of two exemplary procedures 500A and 500B of 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 shown in FIG. 5A and 5B.

[0100] The example procedures 500A and 500B refer to a timer (marked as "timer T3" for simplicity) associated with an RRC resume request (e.g., T319). With reference to Figures 5A and 5B, 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.

[0101] Steps 511-514 in the exemplary procedures 500A and 500B are the same. The difference is that the exemplary procedure 500A includes step 516, whereas the exemplary procedure 500B includes steps 516B and 517B. In particular, the steps in the exemplary procedures 500A and 500B are as follows:

[0102] In step 511, a remote UE 501 accesses a BS 503 via a relay UE 502, which is, for example, a L2 U2N relay UE.

[0103] In step 512, the remote UE 501 receives a configuration from the BS 503, e.g., via an RRCReconfiguration message, including a timer T3 associated with the RRC resume request (e.g., T319). In some embodiments, the configuration may be broadcast via SIB1. For example, the configuration includes a timer value for timer T3.

[0104] In step 513, the BS 503 sends a RRCRelease message including a suspend indication to the remote UE 501.

[0105] In step 514, the remote UE 501 enters the RRC_INACTIVE state after receiving the RRCRelease message.

[0106] In step 515, the remote UE 501 initiates the procedure when an upper layer or access stratum (AS) of the remote UE 501 requests resumption of a suspended RRC connection. In some embodiments, the remote UE 501 sends a RRCResumeRequest message or a RRCResumeRequest1 message.

[0107] In some embodiments, the remote UE 501 may start a timer T3 (e.g., T319) when sending the RRC Resume Request message. For example, the RRC Resume Request message includes a Resume ID and a Resume Cause (e.g., mo-Data, mo-VoiceCall, mo-VideoCall, mo-SMS, rna-Update, etc.).

[0108] In some embodiments, the remote UE 501 may continue relay (re)selection related measurements and / or relay (re)selection related evaluations. If the conditions for relay (re)selection are met, the remote UE 501 shall perform relay (re)selection.

[0109] In step 516 in the example procedure 500A, the remote UE 501 stops timer T3 (eg, T319) when at least one of the following conditions is met: (1) When an RRCResume message, an RRCSetup message, an RRCRelease message, or an RRCRelease message with suspendConfig is received. (2) When an RRCReject message is received. (3) When cell is reselected. (4) When broadcasting (re)selected. (5) The remote UE 501 receives a notification from the relay UE 502 associated with at least one of a handover of the relay UE 502, an RLF on a Uu link of the relay UE 502, or a cell reselection of the relay UE 502. For example, the Uu link is between the relay UE 502 and the BS 503, e.g., the Uu link shown in FIG. (6) The remote UE 501 receives, from the relay UE 502, a notification associated with at least one of a handover failure of the relay UE 502 or a recovery failure on the Uu link of the relay UE 502. (7) When declaring a sidelink RLF on a link between the UE and a relay UE.

[0110] At step 516B in the example procedure 500B, in different embodiments, there may be two options: option 1 and option 2. In some embodiments, the remote UE 501 may perform an action for these options, for example, at step 517B, when transitioning to an RRC_IDLE state with release cause "RRC Restart Failed." (1) Option 1: If a relay (re)selection occurs while timer T3 (e.g., T319) is running and the serving cell of the (re)selected relay UE (e.g., another relay UE different from relay UE 502) is different from the current serving cell of remote UE 501, remote UE 501 may enter RRC_IDLE state. (2) Option 2: If, during the execution of timer T3 (e.g., T319), the remote UE 501 receives a notification from the relay UE 502 associated with at least one of a handover of the relay UE 502, an RLF on the Uu link of the relay UE 502, or a cell reselection from the relay UE 502, the remote UE 501 may enter an RRC_IDLE state.

[0111] At step 517B in the example procedure 500B, the remote UE 501 may perform actions upon transitioning to the RRC_IDLE state. In some embodiments, the remote UE 501 performs at least one of the following actions upon transitioning to the RRC_IDLE state: In different embodiments, it may be contemplated that the remote UE 501 may perform more or less actions. (1) reset the media access control (MAC), (2) If the variable pendingRNA-Update is set to true, set it to false. The UE variable VarPendingRNA-Update indicates whether there is a Radio Access Network-based Notification Area (RNA) Update procedure pending; (3) Stop all running timers except T302, T320, T325, T330, T331, and T400, (4) Discard the UE Inactive AS context if there is one; (5) Release suspendConfig, if set. (6) Delete all entries in VarConditionalReconfig, if any. (7) Releasing all radio resources, including releasing the Radio Link Control (RLC) entity, Backhaul Adaptation Protocol (BAP) entity, MAC configuration and associated Packet Data Convergence Protocol (PDCP) entities and Service Data Adaptation Protocol (SDAP) entities for all established Resource Blocks (RBs) and Backhaul (BH) RLC channels; (8) Indicate to higher layers the release of the RRC connection along with the cause of the release, or (9) Discard any segments of the stored segmented RRC message.

[0112] In some embodiments of the present disclosure, the triggering conditions for stopping timer T319 may be defined, for example, in a standard document as follows: "upon receipt of RRCResume, RRCSetup, RRCRelease, suspendConfig or RRCRelease with RRCReject message, upon cell reselection, upon abort of connection establishment by higher layers, upon relay (re)selection, upon receipt of relay handover indication, Uu RLF and / or cell reselection, upon receipt of relay handover failure and / or Uu recovery failure indication, and upon declaration of sidelink RLF."

[0113] Those skilled in the art will appreciate that the sequence of operations in the example procedures 500A and 500B of FIG. 5 may be changed, and some of the operations in the example procedures 500A and 500B of FIG. 5 may be deleted or modified without departing from the spirit and scope of the present disclosure.

[0114] 6A and 6B are flowcharts of two exemplary procedures 600A and 600B of wireless communication according to some embodiments of the present disclosure. Details described in all other embodiments of the present disclosure are applicable to the embodiments shown in FIG. 6A and 6B.

[0115] The example procedures 600A and 600B refer to a timer (marked as "Timer T4" for simplicity) associated with receiving an RRC release and an RRC reject (e.g., T302). Referring to Figures 6A and 6B, a remote UE 601, a relay UE 602, and a BS 603 may function as the UE 101, the relay UE 103, and the BS 102 shown in Figure 1, respectively.

[0116] Steps 611-614 in the exemplary procedures 600A and 600B are the same. The difference is that the exemplary procedure 600A includes step 615, whereas the exemplary procedure 600B includes steps 615B and 616B. In particular, the steps in the exemplary procedures 600A and 600B are as follows:

[0117] In step 611, a remote UE 601 accesses a BS 603 via a relay UE 602, which is, for example, a L2 U2N relay UE.

[0118] In step 612, the remote UE 601 receives a configuration from the BS 603, e.g., via an RRCReconfiguration message, including a timer T4 associated with receiving an RRC release or an RRC reject (e.g., T320). In some embodiments, the configuration may be broadcast via SIB1. For example, the configuration includes a timer value for timer T4.

[0119] In step 613, the BS 603 sends an RRCReject or RRCRelease message to the remote UE 601, including the waitTime.

[0120] In step 614, the remote UE 601 may start a timer T4 (eg, T302) upon receiving an RRCReject message during an RRC connection establishment or resumption or upon receiving an RRCRelease message with waitTime.

[0121] In step 615 in the example procedure 600A, the remote UE 601 stops timer T4 (eg, T302) when at least one of the following conditions is met: (1) When entering RRC_CONNECTED or RRC_IDLE state. (2) When cell is reselected. (3) When an RRCReject message is received. (4) When broadcasting (re)selected. (5) The serving cell of the (re)selected relay UE (eg, another relay UE different from relay UE 602) is different from the serving cell of remote UE 601. (6) Upon receiving a notification from the relay UE 602 associated with at least one of a handover of the relay UE 602, an RLF on a Uu link of the relay UE 602, or a cell reselection of the relay UE 602. For example, the Uu link is between the relay UE 602 and the BS 603, e.g., the Uu link shown in FIG.

[0122] At step 615B in the example procedure 600B, in different embodiments, there may be two options: option 1 and option 2. In some embodiments, the remote UE 601 may perform an action for these options, for example, at step 616B, when transitioning to an RRC_IDLE state with release cause "RRC Restart Failed." (1) Option 1: If a relay (re)selection occurs while timer T4 (e.g., T302) is running and the serving cell of the (re)selected relay UE (e.g., another relay UE different from relay UE 602) is different from the current serving cell of remote UE 601, remote UE 601 may enter RRC_IDLE state. (2) Option 2: If, during the execution of timer T4 (e.g., T302), the remote UE 601 receives a notification from the relay UE 602 associated with at least one of a handover of the relay UE 602, an RLF on the Uu link of the relay UE 602, or a cell reselection from the relay UE 602, the remote UE 601 may enter an RRC_IDLE state.

[0123] At step 616B in the example procedure 600B, the remote UE 601 may perform actions upon transitioning to the RRC_IDLE state. In some embodiments, the remote UE 601 performs at least one of the following actions upon transitioning to the RRC_IDLE state: In different embodiments, it may be contemplated that the remote UE 601 may perform more or less actions. (1) Reset your MAC. (2) If the variable PendingRNA-Update is set to true, set it to false. The UE variable VarPendingRNA-Update indicates whether there is a pending RNA update procedure. (3) Stop all running timers except T302, T320, T325, T330, T331, and T400, (4) Discard the UE Inactive AS context if there is one; (5) Release suspendConfig, if set. (6) Delete all entries in VarConditionalReconfig, if any. (7) releasing all radio resources, including releasing the RLC entities, BAP entities, MAC configurations and associated PDCP entities and SDAPs for all established RB and BH RLC channels; (8) Indicate to higher layers the release of the RRC connection along with the cause of the release, or (9) Discard any segments of the stored segmented RRC message.

[0124] In some embodiments of the present disclosure, the triggering conditions for stopping timer T302 may be defined, for example, in a standard document as follows: "upon entering RRC_CONNECTED or RRC_IDLE state, upon cell reselection, upon receipt of an RRCReject message, upon relay (re)selection, when the (re)selected serving cell is different from the current serving cell, and upon receipt of a relay handover indication, a Uu RLF, and / or a cell reselection."

[0125] Those skilled in the art will appreciate that the sequence of operations in the example procedures 600A and 600B of FIG. 6 may be changed, and some of the operations in the example procedures 600A and 600B of FIG. 6 may be deleted or modified without departing from the spirit and scope of the present disclosure.

[0126] Some embodiments of the present application also provide a wireless communication device in a case of L2 U2N relay. For example, FIG. 7 shows an example block diagram of a device 700 in a case of L2 U2N relay according to some embodiments of the present application.

[0127] 7, the apparatus 700 may include at least one non-transitory computer-readable medium 702, at least one receiving circuit 704, at least one transmitting circuit 706, and at least one processor 708 coupled to the non-transitory computer-readable medium 702, the receiving circuit 704, and the transmitting circuit 706. The at least one processor 708 may be a CPU, a DSP, a microprocessor, etc. The apparatus 700 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.

[0128] In this drawing, elements such as at least one processor 708, receiving circuitry 704, and transmitting circuitry 706 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 704 and the transmitting circuitry 706 may be combined into a single device, such as a transceiver. In certain embodiments of the present application, the apparatus 700 may further include an input device, a memory, and / or other components.

[0129] In some embodiments of the present application, the non-transitory computer-readable medium 702 may store computer-executable instructions that cause a processor to implement a method with respect to a remote UE as described above. For example, the computer-executable instructions, when executed, cause the processor 708 to interact with the receiving circuitry 704 and the transmitting circuitry 706 to perform steps with respect to the remote UE as shown above.

[0130] In some embodiments of the present application, the non-transitory computer-readable medium 702 may store computer-executable instructions for causing a processor to implement a method for a relay UE as described above. For example, the computer-executable instructions, when executed, cause the processor 708 to interact with the receiving circuitry 704 and the transmitting circuitry 706 to perform steps for a relay UE as shown above.

[0131] In some embodiments of the present application, the non-transitory computer-readable medium 702 may store computer-executable instructions for causing a processor to implement a method with respect to a network device, e.g., a BS, as described above. For example, the computer-executable instructions, when executed, cause the processor 708 to interact with the receiving circuitry 704 and the transmitting circuitry 706 to perform steps with respect to a network device, e.g., a BS, as shown above.

[0132] FIG. 8 illustrates a further exemplary block diagram of an apparatus 800 in a L2 U2N relay case, according to some embodiments of the present application.

[0133] 8, an apparatus 800, e.g., a BS or a UE, may include at least one processor 802 and at least one transceiver 804 coupled to the at least one processor 802. The transceiver 804 may include at least one separate receiving circuit 806 and transmitting circuit 808, or at least one integrated receiving circuit 806 and transmitting circuit 808. The at least one processor 802 may be a CPU, a DSP, a microprocessor, etc.

[0134] According to some other embodiments of the present application, when the apparatus 800 is a remote UE, the processor 802 may be configured to access a serving cell via a relay UE and receive from the serving cell via the transceiver 804 configuration information associated with at least one of a timer associated with an RRC setup request, a timer associated with an RRC re-establishment request, a timer associated with an RRC resume request, or a timer associated with receiving an RRC release or an RRC reject.

[0135] According to some embodiments of the present application, when the apparatus 800 is a relay UE, the processor 802 is configured to access a serving cell, where the remote UE communicates with the serving cell via the relay UE, and receive from the serving cell via the transceiver 804 configuration information associated with at least one of a timer associated with an RRC setup request, a timer associated with an RRC re-establishment request, a timer associated with an RRC resume request, or a timer associated with receiving an RRC release or an RRC reject.

[0136] According to some embodiments of the present application, when the apparatus 800 is a BS, the processor 802 is configured to transmit, via the transceiver 804, to the UE via the relay UE, configuration information associated with at least one of a timer associated with an RRC setup request, a timer associated with an RRC re-establishment request, a timer associated with an RRC resume request, or a timer associated with receiving an RRC release or an RRC reject.

[0137] 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.

[0138] 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.

[0139] 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]

[0140] 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 500A Procedure 500B Procedure 501 Remote UE 502 Relay UE 503 BS 600A Procedure 600B Procedure 601 Remote UE 602 Relay UE 603 BS 700 equipment 702 Non-transitory computer-readable medium 704 Receiving circuit 706 Transmitting Circuit 708 Processor 800 equipment 802 Processor 804 Transmitter / Receiver 806 Receiver Circuit 808 Transmitting circuit

Claims

1. A processor; a transceiver coupled to the processor; A user equipment (UE) comprising: The processor, accessing the serving cell via a relay UE; from the serving cell via the transceiver, A timer associated with a radio resource control (RRC) setup request; a timer associated with the RRC re-establishment request; a timer associated with the RRC resume request; or Timers associated with receiving an RRC Release or RRC Reject receiving configuration information associated with at least one of A user equipment (UE) configured to perform the above.

2. The UE of claim 1 , wherein the processor of the UE is configured to start the timer associated with an RRC setup request in response to transmitting an RRC setup request message.

3. The processor of the UE, When receiving a first notification from the relay UE, the first notification being associated with 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; when declaring a sidelink RLF on a link between the UE and the relay UE, When determining that the relay UE has become unsuitable, When a relay is selected or reselected, or When it is determined that the selected relay UE or the reselected relay UE has become unsuitable.

3. The UE of claim 2, configured to stop the timer associated with an RRC setup request in response to satisfying at least one of:

4. In response to expiration of the timer associated with an RRC setup request, the processor of the UE: Failure to establish an RRC connection, a sidelink RLF on a link between the UE and the relay UE; an RLF on a Uu link of the relay UE; Receiving a notification of handover of the relay UE; the UE determining that the relay UE has become unsuitable; Relay selection or relay reselection, or The UE determines that the selected relay UE or the reselected relay UE has become unsuitable. The UE of claim 2 , configured to transmit information indicative of at least one of the following to a higher layer of the UE:

5. The UE of claim 1 , wherein the processor of the UE is configured to start the timer associated with an RRC re-establishment request in response to transmitting an RRC re-establishment request message.

6. The processor of the UE, When receiving a first notification from the relay UE, the first notification being associated with 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; when declaring a sidelink RLF on a link between the UE and the relay UE, the UE determining that the relay UE has become unsuitable; When a relay is selected or reselected, or The UE determines that the selected relay UE or the reselected relay UE has become unsuitable.

6. The UE of claim 5, configured to stop the timer associated with an RRC re-establishment request in response to satisfying at least one of:

7. The processor of the UE, receiving the first notification from the relay UE; receiving a second notification from the relay UE, the second notification being associated with at least one of a handover failure of the relay UE or a recovery failure on the Uu link of the relay UE; declaring the sidelink RLF on the link between the UE and the relay UE; a channel quality of the link between the UE and the relay UE is less than a first threshold; declaring a sidelink RLF on a link between the UE and the selected or reselected relay UE; or the channel quality of the link between the UE and the selected relay UE or the reselected relay UE is less than a second threshold.

7. The UE of claim 3, configured to determine that the relay UE has become unsuitable, or to determine that the selected relay UE or a reselected relay UE has become unsuitable, in response to at least one of the following:

8. The UE of claim 1 , wherein the processor of the UE is configured to start the timer associated with an RRC resume request in response to transmitting an RRC resume request message.

9. The processor of the UE, continuing at least one of measurements related to relay selection or relay reselection or evaluations related to relay selection or relay reselection; performing relay selection or relay reselection in response to the condition for relay selection or relay reselection being satisfied; The UE of claim 2 or 8, configured to:

10. The processor of the UE, When receiving a first notification from the relay UE, the first notification being associated with 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; or upon receiving a second notification from the relay UE, the second notification being associated with at least one of a handover failure of the relay UE or a recovery failure on the Uu link of the relay UE; or When declaring a sidelink RLF on a link between the UE and the relay UE.

10. The UE of claim 8, configured to stop the timer associated with an RRC restart request in response to satisfying at least one of:

11. the processor of the UE in response to the timer associated with an RRC restart request being running; and a second serving cell of the selected relay UE or the reselected relay UE is different from the serving cell of the UE; or receiving a notification from the relay UE associated with 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 8, configured to enter an RRC idle state in response to

12. The UE of claim 1, wherein the processor of the UE is configured to start the timer associated with receiving an RRC release or an RRC reject in response to transmitting an RRC resume request message.

13. The processor of the UE, When a relay is selected or reselected, a second serving cell of the selected relay UE or the reselected relay UE is different from the serving cell of the UE; or Upon receiving a notification from the relay UE associated with 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.

13. The UE of claim 12, configured to stop the timer associated with receiving an RRC Release or an RRC Reject in response to satisfying at least one of:

14. The processor of the UE indicates that the timer associated with receiving an RRC Release or an RRC Reject is running; and a second serving cell of the selected relay UE or the reselected relay UE is different from the serving cell of the UE; or receiving a notification from the relay UE associated with 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; 13. The UE of claim 12, configured to enter an RRC idle state in response to:

15. A processor; a transceiver coupled to the processor; A network node comprising: The processor, via the transceiver, to a user equipment (UE) via a relay UE; A timer associated with a radio resource control (RRC) setup request; a timer associated with the RRC re-establishment request; a timer associated with the RRC resume request; or Timers associated with receiving an RRC Release or RRC Reject a network node configured to transmit configuration information associated with at least one of the

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