Method and apparatus for designing an adaptation layer and for handling failures in a sidelink relay system - Patents.com

Abstract

According to one embodiment, the method includes the steps of receiving a radio resource control (RRC) configuration request from a user equipment (UE), where a PC5 RRC connection for a link between the UE and a relay UE is established; sending an RRC configuration request to a base station (BS), where the RRC connection for a link between the relay UE and the BS is established; receiving response information from the BS, where the response information includes at least one of a cell radio network temporary identifier (C-RNTI) and an identifier (ID) of the UE; and sending the response information to the UE. The relay UE is required to send a notification to the UE when a radio link failure (RLF) between the relay UE and the BS occurs. Furthermore, the relay UE is required to send a notification to the BS when an RLF between the relay UE and the UE occurs.

Description

[Technical field]

[0001] FIELD Embodiments of the present application relate generally to wireless communication technologies, and more particularly to a method and apparatus for designing an adaptation layer and handling impairments in a sidelink relay system. [Background technology]

[0002] Vehicle to Everything (V2X) has 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 a base station (BS) or core network.

[0003] The Third Generation Partnership Project (3GPP) promotes the deployment of relay nodes (RNs) in wireless communication systems. One purpose of deploying RNs is to enhance the coverage area of ​​a BS by improving the throughput of user equipment (UE) located in the coverage or far from the BS, which may lead to relatively low signal quality. The RN may also be named a relay UE in some cases. A 3GPP 5G sidelink system including a relay UE may be named a sidelink relay system.

[0004] Currently, in 3GPP 5G New Radio (NR) systems and the like, details on how to design an adaptation layer and handle impairments in a sidelink relay system have not yet been specifically discussed. Summary of the Invention [Means for solving the problem]

[0005] Some embodiments of the present application provide a method for wireless communication, which may be performed by a relay UE. The method includes the steps of receiving a Radio Resource Control (RRC) configuration request from a UE, where a PC5 RRC connection of a link between the UE and the relay UE is established, sending an RRC configuration request to a BS, where the RRC connection of a link between the relay UE and the BS is established, receiving response information from the BS, where the response information includes at least one of a Cell Radio Network Temporary Identifier (C-RNTI) and an Identifier (ID) of the UE, and sending the response information to the UE.

[0006] Some embodiments of the present application also provide an apparatus for wireless communication, the apparatus including a non-transitory computer-readable medium storing computer-executable instructions, a receiving circuitry, a transmitting circuitry, and a processor coupled to the non-transitory computer-readable medium, the receiving circuitry, and the transmitting circuitry, the computer-executable instructions causing the processor to implement the above-mentioned method for receiving response information made by a relay UE.

[0007] Some embodiments of the present application provide a further method for wireless communication, which may be performed by a BS, including the steps of receiving an RRC setup request from a relay UE, where a PC5 RRC connection of a link between the UE and the relay UE is established and an RRC connection of a link between the relay UE and the BS is established, and sending response information to the relay UE, where the response information includes at least one of a C-RNTI and an ID of the UE.

[0008] Some embodiments of the present application also provide an apparatus for wireless communication, the apparatus including a non-transitory computer-readable medium storing computer-executable instructions, a receiving circuitry, a transmitting circuitry, and a processor coupled to the non-transitory computer-readable medium, the receiving circuitry, and the transmitting circuitry, the computer-executable instructions causing the processor to implement the above-mentioned method for transmitting response information made by a BS.

[0009] Some embodiments of the present application provide a further method for wireless communication, which may be performed by a relay UE, including the steps of: establishing a PC5 RRC connection for a link between the UE and the relay UE, establishing an RRC connection for a link between the relay UE and a BS, establishing a relay connection for a link between the UE and the BS, detecting whether a failure occurs on the link between the UE and the relay UE, and transmitting failure information to the BS in response to detecting that a failure occurs on the link between the relay UE and the UE.

[0010] Some embodiments of the present application also provide an apparatus for wireless communication, the apparatus including a non-transitory computer-readable medium storing computer-executable instructions, a receiving circuitry, a transmitting circuitry, and a processor coupled to the non-transitory computer-readable medium, the receiving circuitry, and the transmitting circuitry, the computer-executable instructions causing the processor to implement the above-mentioned method for transmitting fault information performed by a relay UE.

[0011] Some embodiments of the present application provide a further method for wireless communication, which may be performed by a relay UE, including the steps of: establishing a relay logical connection of a link between the UE and a BS; detecting whether a failure occurs on the link between the relay UE and the BS, where a PC5 RRC connection of the link between the UE and the relay UE is established and an RRC connection of the link between the relay UE and the BS is established; and sending a failure notification to the UE in response to detecting that a failure occurs on the link between the relay UE and the BS.

[0012] Some embodiments of the present application also provide an apparatus for wireless communication, the apparatus including a non-transitory computer-readable medium storing computer-executable instructions, a receiving circuitry, a transmitting circuitry, and a processor coupled to the non-transitory computer-readable medium, the receiving circuitry, and the transmitting circuitry, the computer-executable instructions causing the processor to implement the above-mentioned method for transmitting a failure notification made by a relay UE.

[0013] Some embodiments of the present application provide a further method for wireless communication, which may be performed by a UE, including receiving a notification associated with a failure from a relay UE, where a PC5 RRC connection of a link between the UE and the relay UE is established, an RRC connection of a link between the relay UE and a BS is established, and the notification associated with the failure indicates a failure on the link between the relay UE and the BS, and initiating a relay reselection procedure.

[0014] Some embodiments of the present application also provide an apparatus for wireless communications that includes a non-transitory computer-readable medium having computer-executable instructions stored thereon, a receiving circuitry, a transmitting circuitry, and a processor coupled to the non-transitory computer-readable medium, the receiving circuitry, and the transmitting circuitry, the computer-executable instructions causing the processor to implement the above-mentioned method for initiating a relay reselection procedure performed by a UE.

[0015] The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.

[0016] To describe the manner in which the advantages and features of the present application can be obtained, the present application will be described by reference to specific embodiments thereof, which are illustrated in the accompanying drawings. These drawings depict only example embodiments of the present application and are therefore not to be considered as limiting its scope. [Brief description of the drawings]

[0017] [Figure 1] FIG. 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 in accordance with some embodiments of the present application. [Diagram 3] 1 is an example flowchart of a sidelink UE information procedure in accordance with some embodiments of the present application. [Figure 4] FIG. 1 is a diagram of an exemplary protocol stack having a Sidelink Adaptation Protocol (SLAP) layer in accordance with some embodiments of the present application. [Diagram 5] 1 is a flowchart of a method for receiving response information according to some embodiments of the present application. [Figure 6] 1 is a flowchart of a method for transmitting response information according to some embodiments of the present application. [Figure 7] 1 is a flowchart of a method for transmitting fault information according to some embodiments of the present application. [Figure 8] 1 is a flowchart of a method for sending a fault notification according to some embodiments of the present application. [Figure 9] 1 is a flowchart of a method for initiating a relay reselection procedure according to some embodiments of the present application. [Figure 10]FIG. 1 is a simplified block diagram of an apparatus for a fault handling procedure according to some embodiments of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The detailed description of the accompanying drawings is intended as an illustration of a preferred embodiment of the present application, and is not intended to represent the only form in which the present application may be practiced. It should be understood that the same or equivalent functions may be accomplished by various embodiments that are intended to be encompassed within the spirit and scope of the present application.

[0019] 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 3GPP 5G, 3GPP LTE Release 8, etc. With the development of network architectures and new service scenarios, it is contemplated that all the embodiments in the present application are also applicable to similar technical problems, and furthermore, the technical terms listed in the present application may change, but should not affect the principle of the present application.

[0020] FIG. 1 illustrates a schematic diagram of a wireless communication system in accordance with some embodiments of the present application.

[0021] 1, for illustrative purposes, the wireless communication system 100 includes a UE 101, a BS 102, and a relay UE 103. Although a particular number of UEs, relay UEs, and BSs are depicted in FIG. 1, it is contemplated that any number of UEs, relay UEs, and BSs may be included in the wireless communication system 100.

[0022] Due to the long distance between UE 101 and BS 102, UE 101 and BS 102 communicate with each other via relay UE 103. UE 101 may be connected to relay UE 103 via a network interface, for example, a PC5 interface as defined in 3GPP standard documents. Relay UE 103 may be connected to BS 102 via a network interface, for example, a Uu interface as defined in 3GPP standard documents. Referring to FIG. 1, UE 101 is connected to relay UE 103 via a PC5 link, and relay UE 103 is connected to BS 102 via a Uu link.

[0023] In some embodiments of the present application, the UE 101 or relay UE 103 may include a computing device such as a desktop computer, a laptop computer, a personal digital assistant (PDA), a tablet computer, a smart television (e.g., a television connected to the Internet), a set-top box, a game console, a security system (including security cameras), a vehicle-mounted computer, a network device (e.g., routers, switches, and modems), and the like.

[0024] In some further embodiments of the present application, the UE 101 or relay UE 103 may include a portable wireless communications device, a smartphone, a cellular phone, a flip phone, a device having a subscriber identity module, a personal computer, a selective call receiving network, or any other device capable of transmitting and receiving communication signals over a wireless network.

[0025] In some other embodiments of the present application, the UE 101 or relay 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 relay 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 device, or described using other technical terms used in the art.

[0026] The BSs 102 may be distributed throughout a geographic region. In some embodiments of the present application, each of the BSs 102 may 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 described using other terminology used in the art. The BSs 102 are generally part of a radio access network that may include one or more controllers communicatively coupled to one or more corresponding BSs 102.

[0027] 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.

[0028] 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 on the downlink (DL) using an OFDM modulation scheme, 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 WiMAX, among other protocols.

[0029] 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 licensed spectrum, while in other embodiments, the BS 102 may communicate over 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.

[0030] The UE 101 may access the BS 102 to receive data packets from the BS 102 via a downlink channel and / or transmit data packets to the BS 102 via an uplink channel. In normal operation, the UE 101 does not know when the BS 102 transmits data packets to the UE 101, so the UE 101 must be constantly awake and monitor a downlink channel (e.g., a physical downlink control channel (PDCCH)) to prepare 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, it will lead to significant power waste, which is problematic for power-limited or power-sensitive UEs.

[0031] FIG. 2 illustrates an example flow chart of a sidelink RRC reconfiguration procedure in accordance with some embodiments of the present application.

[0032] As shown in FIG. 2, in step 201, UE(a) (e.g., UE 101 as illustrated and shown in FIG. 1) initiates a sidelink RRC reconfiguration procedure for UE(b) (e.g., relay UE 1013 as illustrated and shown in FIG. 1) by sending an RRCReconfigurationSidelink message to UE(b).

[0033] If the sidelink RRC reconfiguration procedure is completed successfully, then UE(b) may send an "RRC reconfiguration complete sidelink message", e.g. an RRCReconfigurationCompleteSidelink message as defined in the 3GPP standard documents, to UE(a) in step 202. Alternatively, if the sidelink RRC reconfiguration procedure is not completed successfully, then UE(b) may send an "RRC reconfiguration failure sidelink message", e.g. an RRCReconfigurationFailureSidelink message as defined in the 3GPP standard documents, to UE(a) in step 202.

[0034] 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.

[0035] A UE (e.g., UE(a) as illustrated and depicted in FIG. 2) may initiate a sidelink RRC reconfiguration procedure and take action on the corresponding PC5 RRC connection if: - release of a sidelink DRB associated with a peer UE (e.g. UE (b) as illustrated and depicted in FIG. 2 ); - Establishment of a sidelink DRB associated with the peer UE; - changes to parameters contained in the Sidelink Radio Bearer (SLRB)-Config of a Sidelink DRB associated with the peer UE; - configuration information of the peer UE for NR sidelink measurements and reporting; and - Configuration information for sidelink CSI reference signal resources.

[0036] 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., timer T400 expiration) or a sidelink RRC reconfiguration failure has been declared.

[0037] The following table shows an implementation of timer T400 as specified in the 3GPP standard documents, including start conditions, stop conditions, action on expiration and possible common names for the timer.

[0038] [Table 1]

[0039] FIG. 3 illustrates an example flowchart of a sidelink UE information procedure in accordance with some embodiments of the present application.

[0040] As illustrated in Fig. 3, in step 301, a UE (e.g., UE 101 as illustrated and shown in Fig. 1 or UE(a) as illustrated and shown in Fig. 2) sends a "sidelink UE information NR message", e.g., a SidelinkUEinformationNR message as defined in a 3GPP standard document, to a BS (e.g., BS 102 as illustrated and shown in Fig. 1). Specifically, the sidelinkUEinformationNR message may include sidelink failure information. The sidelink failure information may include a sidelink destination ID and a sidelink failure cause.

[0041] Currently, in the sidelink relay system under 3GPP 5G NR, details on how to design the adaptation layer and handle failures have not yet been specifically discussed. The embodiments of the present application provide a failure handling procedure in the sidelink relay system, for example, whether the relay UE reports a failure notification to the UE when an RLF of a link between the relay UE and another UE occurs or when the relay UE receives an RRCReconfigurationFailureSidelink message from another UE. Further details will be illustrated in the following text in combination with the accompanying drawings.

[0042] FIG. 4 illustrates an exemplary protocol stack with a Sidelink Adaptation Protocol (SLAP) layer in accordance with some embodiments of the present application.

[0043] The embodiment of FIG. 4 illustrates protocol stacks on each side of UE1 (e.g., UE101 as illustrated and shown in FIG. 1, UE(a) as illustrated and shown in FIG. 2, or UE as illustrated and shown in FIG. 3), relay UE (e.g., relay UE103 as illustrated and shown in FIG. 1 or UE(b) as illustrated and shown in FIG. 2), and BS (e.g., BS102 as illustrated and shown in FIG. 1, or BS as illustrated and shown in FIG. 3). UE1 is connected to the relay UE via a PC-5 interface, which may also be named a PC5 interface. The relay UE is connected to the BS via a Uu interface.

[0044] In particular, as illustrated in FIG. 4, the UE1 side includes protocol layers of PC5-PHY, PC5-MAC, PC5-RLC, Uu-PDCP and Uu-SDAP. The relay UE side includes protocol layers of PC5-PHY, PC5-MAC, PC5-RLC, Uu-PHY, Uu-MAC and Uu-RLC. The BS side includes protocol layers of Uu-PHY, Uu-MAC, Uu-RLC, Uu-PDCP and Uu-SDAP. According to some embodiments of the present application, the relay UE side and the BS side further include a SLAP layer as illustrated in FIG. 4. Specific examples of using the SLAP layer are described in the following embodiments, for example, in FIG. 5 and FIG. 6.

[0045] 5 illustrates a flowchart of a method for receiving response information according to some embodiments of the present application. The method may be performed by a relay UE (e.g., the relay UE 103 illustrated and shown in FIG. 1 or the UE (b) as illustrated and shown in FIG. 2). Although described with respect to a UE, it should be understood that other devices may be configured to perform a method similar to that of FIG. 5.

[0046] In an exemplary method 500 as illustrated in Figure 5, a relay UE receives an RRC setup request from a UE (e.g., UE 101 as illustrated and shown in Figure 1) at operation 501. The relay UE sends an RRC setup request to a BS (e.g., BS 102 as illustrated and shown in Figure 1, or a BS as illustrated and shown in Figure 3) at operation 502. The embodiment of Figure 5 assumes that a PC5 RRC connection for a link between the UE and the relay UE has been established, and an RRC connection for a link between the relay UE and the BS has been established.

[0047] In operation 503, the relay UE receives response information from the BS. The response information includes at least one of a C-RNTI and a UE ID. In one example, the C-RNTI and / or the UE ID is used in a SLAP layer header of the relay UE.

[0048] At operation 504, the relay UE transmits response information to the UE. In one example, the response information includes a mapping association between the C-RNTI and the ID of the UE. The response information may further include configuration information of the SLAP layer of the relay UE. In a further example, the response information includes an ID of a logical channel between the UE and the BS. Specifically, the relay UE or the BS may configure the reduced size UE ID to be included in a header of a packet data unit (PDU) format. Thus, a mapping between the C-RNTI and the reduced size UE ID should be configured.

[0049] In another example, the response information includes a mapping association between "the ID of the logical channel between the UE and the relay UE" and "the ID of the logical channel between the relay UE and the BS". In other words, in this example, the ID of the logical channel between the first UE and the relay UE is included in the header of the PDU format. After the relay UE receives a packet from the UE with one logical channel ID, the relay UE will convey this PDU including this packet to the corresponding ID of the logical channel between the relay UE and the BS based on the mapping association.

[0050] In a further example, the response information includes a mapping association between "an ID of a logical channel between the UE and the relay UE" and "an ID of a logical channel between the UE and the BS". In other words, in this example, an ID of a logical channel between the first UE and the BS is included in the header of the PDU format. After the relay UE receives a packet from the UE with one logical channel ID, the relay UE will add this ID of the logical channel between the UE and the BS based on the mapping association to the header of the PDU format, and convey this PDU including this packet to one logical channel between the relay UE and the BS based on the mapping association.

[0051] In one embodiment, the relay UE further receives an RRC configuration complete message from the UE and sends an RRC configuration complete message to the BS.

[0052] In a further embodiment, the relay UE receives one or more packets associated with different UE bearers from the UE. The relay UE then transmits a SLAP PDU to the BS, which includes the received one or more packets. The header of the SLAP PDU may include one or more logical channel IDs associated with the one or more packets. The one or more logical channel IDs may be "IDs of logical channels between the UE and the relay UE" or "IDs of logical channels between the UE and the BS". That is, multiple packets associated with different UE bearers can be multiplexed into one PDU format. Multiple logical channel IDs should be added to the header.

[0053] Details described in all other embodiments of the present application (e.g., details regarding the response information received from the BS) are applicable to the embodiment of Fig. 5. Moreover, details described in the embodiment of Fig. 5 are applicable to all embodiments of Figs. 1-4 and 6-10.

[0054] 6 illustrates a flowchart of a method for transmitting response information according to some embodiments of the present application. The method may be performed by a BS (e.g., BS 102 as illustrated and shown in FIG. 1, or a BS as illustrated and shown in FIG. 3). Although described with respect to a BS, it should be understood that other devices may be configured to perform a method similar to that of FIG. 6.

[0055] In the exemplary method 600 as illustrated in FIG. 6, in operation 601, the BS receives an RRC setup request from a relay UE (e.g., the relay UE 103 as illustrated and illustrated in FIG. 1 or the UE (b) as illustrated and illustrated in FIG. 2). The embodiment of FIG. 6 assumes that a PC5 RRC connection of a link between the UE (e.g., the UE 101 as illustrated and illustrated in FIG. 1) and the relay UE is established, and an RRC connection of a link between the relay UE and the BS is established. In operation 602, the BS sends response information to the relay UE. The response information includes at least one of a C-RNTI and an ID of the UE.

[0056] The response information in the embodiment of Figure 6 has a similar format or content to those of the response information in the embodiment of Figure 5. For example, similar to the embodiment of Figure 5, in the embodiment of Figure 6, the response information may include a mapping association between the C-RNTI and the ID of the UE. The response information may further include an ID of a logical channel between the UE and the BS.

[0057] In one example, the BS receives an RRC configuration complete message from the relay UE, e.g., the UE sends an RRC configuration complete message to the relay UE, and then the relay UE sends an RRC configuration complete message to the BS.

[0058] In a further example, the BS receives a SLAP PDU from a relay UE. The SLAP PDU includes one or more packets associated with different UE bearers. The one or more packets are transmitted from the UE. The SLAP PDU in the embodiment of FIG. 6 may be of a similar format or content to those of the SLAP PDU in the embodiment of FIG. 5.

[0059] Details described in all other embodiments of the present application (e.g. details regarding response information transmitted to the relay UE) are applicable to the embodiment of Fig. 6. Moreover, details described in the embodiment of Fig. 6 are applicable to all embodiments of Figs. 1-5 and 7-10.

[0060] The following text describes a specific embodiment 1 of the method as depicted and illustrated in FIGS.

[0061] EMBODIMENT 1 According to embodiment 1, a UE (e.g., a UE 101 as shown and illustrated in FIG. 1 ), a relay UE (e.g., a relay UE 103 as shown and illustrated in FIG. 1 ), and a BS (e.g., a BS 102 as shown and illustrated in FIG. 1 ) perform the following steps: (1) An RRC connection of a PC5 link between the UE 101 and the relay UE 103 is already established. An RRC connection of a Uu link between the relay UE and the BS 102 is already established. (2) UE 101 sends an RRC setup request to relay UE 103. (3) The relay UE 103 forwards the RRC setup request to the BS 102 . The RRC configuration request may be included in another RRC message, for example an RRCReconfigurationSidelink message, i.e. the relay UE 103 may send the BS 102 an RRCReconfigurationSidelink message containing the RRC configuration request. (4) The BS 102 sends an RRC reconfiguration message including a response to the relay UE 103. The response is relayed by the relay UE 103 to the UE 101. The RRC reconfiguration message relayed by the relay UE 103 may include the C-RNTI of the UE 101. The RRC reconfiguration message may further include a mapping association between the C-RNTI and the identity of the UE 101. At least one of the C-RNTI and the identity of the UE 101 will be included in the SLAP layer header of the relay UE 103. (5) The relay UE 103 forwards the response to the UE 101. After receiving the RRC setup request, the BS 102 may send an RRC setup message to the UE 101 via the relay UE 103. The RRC setup message may be included in a response forwarded by the relay UE 103. (6) UE 101 sends an RRC setup complete message to BS 102 via relay UE 103. · The identity of the UE 101, e.g. C-RNTI, should be added to the RRC configuration complete message. (7) UE 101 will send a data packet associated with a different logical channel ID to relay UE 103. (8) After the relay UE 103 receives the multiple data packets associated with different logical channel IDs, the relay UE 103 may send a PDU format to the BS 102. · Multiple data packets associated with different UE bearers can be multiplexed into one PDU format. · Multiple logical channel IDs should be added to the PDU format header. (9) The BS 102 receives a PDU format that includes multiple data packets associated with different UE bearers. · The BS 102 can distinguish between different UE bearers based on the logical channel ID in the header of the PDU format.

[0062] 7 illustrates a flowchart of a method for transmitting fault information according to some embodiments of the present application. The method may be performed by a relay UE (e.g., a relay UE 103 as illustrated and shown in FIG. 1 or a UE (b) as illustrated and shown in FIG. 2). Although described with respect to a UE, it should be understood that other devices may be configured to perform a method similar to that of FIG. 7.

[0063] In an illustrative method 700 as illustrated in FIG. 7, in operation 701, a relay UE (e.g., relay UE 103 illustrated and shown in FIG. 1) establishes a PC5 RRC connection for a link between a UE (e.g., UE 101 illustrated and shown in FIG. 1) and the relay UE.

[0064] At operation 702, the relay UE establishes an RRC connection for a link between the relay UE and a BS (e.g., BS 102 as illustrated and shown in FIG. 1, or a BS as illustrated and shown in FIG. 3). At operation 703, the relay UE establishes a relay connection for the link between the UE and the BS.

[0065] In operation 704, the relay UE detects whether a failure occurs on the link between the UE and the relay UE. In operation 705, if the relay UE detects that a failure occurs on the link between the UE and the relay UE, the relay UE sends failure information to the BS. For example, the failure information may be: Sidelink UE information messages, e.g. the SidelinkUEinformation message as defined in the 3GPP standard documents; Control PDUs at the SLAP layer of the relay UE, and · It may be included in one of the Medium Access Control (MAC) Control Elements (CE).

[0066] In some embodiments, the failure information includes a UE ID configured by the BS. The UE ID may be a C-RNTI or an ID of the UE. The UE ID may be used in the SLAP layer header of the relay UE.

[0067] In some other embodiments, the failure information includes at least one of a failure cause, an ID of the UE, and an ID of a relay UE. The failure cause may be a listen-before-talk (LBT) failure or a beam failure recovery failure.

[0068] In some embodiments, the relay UE detects that a failure has occurred on the link between the UE and the relay UE based on at least one of the following conditions: The maximum number of retransmissions of the Radio Link Control (RLC) entity of the relay UE has been reached; Expiration of the timer for RRC reconfiguration transmission for sidelink, The maximum number of consecutive Hybrid Automatic Repeat Request (HARQ) discontinuous transmissions (DTX) has been reached, Integrity check failure, LBT disorder, and -Beam failure recovery failure.

[0069] In some embodiments, the relay UE sends an RRC reconfiguration sidelink message to the UE. In some cases, the relay UE further receives an RRC reconfiguration failure sidelink message from the UE. Upon receiving the RRC reconfiguration failure sidelink message, the relay UE detects that a failure has occurred on the link between the UE and the relay UE.

[0070] Details described in all other embodiments of the present application (e.g. details of how to handle failures on the link between the UE and the relay UE) are applicable to the embodiment of Fig. 7. Moreover, details described in the embodiment of Fig. 7 are applicable to all embodiments of Figs. 1-6 and 8-10.

[0071] The following text describes a specific embodiment 2 of the method as depicted and illustrated in FIG.

[0072] EMBODIMENT 2 According to embodiment 2, a UE (e.g., a UE 101 as shown and illustrated in FIG. 1 ), a relay UE (e.g., a relay UE 103 as shown and illustrated in FIG. 1 ), and a BS (e.g., a BS 102 as shown and illustrated in FIG. 1 ) perform the following steps: (1) An RRC connection of a PC5 link between the UE 101 and the relay UE 103 is already established. An RRC connection of a Uu link between the relay UE and the BS 102 is already established. (2) A relay RRC connection is established for the link between the UE 101 and the BS 102. The RRC relay connection for the link is a logical link, and may also be named an “end-to-end link” between the UE 101 and the BS 102. (3) There may be the following possible steps of the relay UE 103: Step (3a): The relay UE 103 detects the sidelink RLF between the UE 101 and the relay UE 103 when at least one of the following conditions occurs: upon an indication from the sidelink RLC entity of the relay UE 103 that the maximum number of retransmissions for a particular destination (i.e., the UE 101) has been reached, or upon expiration of timer T400, or upon indication from the sidelink MAC entity of the relay UE 103 that the maximum number of consecutive HARQ DTXs for a particular destination has been reached, or In response to an integrity check failure indication from the sidelink PDCP entity of the relay UE 103 for SL-SRB2 (sidelink signalling radio bearer 2) or SL-SRB3: a) LBT disorder, or b) Beam obstruction recovery failure. Step (3b): After the relay UE 103 sends an RRCReconfigurationSidelink message to the UE 101, the relay UE 103 receives an RRCReconfigurationFailureSidelink message from the UE 101. (4) The relay UE 103 reports the fault information to the BS 102. The fault information may differ according to the following different cases 1-1 to 1-4. Case 1-1: A sidelink RLF occurs between the UE 101 and the relay UE 103. The relay UE will declare a sidelink RLF. Case 1-2: The relay UE 103 receives an RRCReconfigurationFailureSidelink message from the UE 101. -For Case 1-1 and Case 1-2: The relay UE 103 reports failure information including the configured UE ID to the BS 102. The UE ID configured by the BS 102 may be the C-RNTI or UE ID used in the SLAP layer of the relay UE 103. The Sidelink UE information message or the control PDU at the SLAP layer can be used to transmit the fault information. Case 1-3: Unlicensed spectrum is used for the PC5 link between the UE 101 and the relay UE 103. An LBT failure may need to be indicated to the BS 102. -For cases 1-3: A new cause (e.g., LBT failure) should be added to the SidelinkUEinformation message, and The corresponding UE ID is also required, e.g., the ID of the UE 101 and / or the ID of the Relay UE 103 is included in the SidelinkUEinformation message. Case 1-4: FR2 is used for the link between the UE 101 and the relay UE 103. Beam obstruction related information may be indicated to the BS 102. -For cases 1-4: In FR2, the BS 102 or the relay UE 103 will configure a set of available beams. Once all beams fail, the relay UE 103 will report the beam failure recovery failure and the corresponding UE ID (e.g., the ID of the UE 101 and / or the ID of the relay UE 103) to the serving cell of the BS 102.

[0073] 8 illustrates a flowchart of a method for sending a failure notification according to some embodiments of the present application. The method may be performed by a relay UE (e.g., a relay UE 103 as illustrated and shown in FIG. 1 or a UE (b) as illustrated and shown in FIG. 2). Although described with respect to a UE, it should be understood that other devices may be configured to perform a method similar to that of FIG. 8.

[0074] In an exemplary method 800 as illustrated in FIG. 8, in operation 801, a relay UE (e.g., relay UE 103 as illustrated and shown in FIG. 1) establishes a relay logical connection of a link between a UE (e.g., UE 101 as illustrated and shown in FIG. 1) and a BS (e.g., BS 102 as illustrated and shown in FIG. 1, or a BS as illustrated and shown in FIG. 3).

[0075] In operation 802, the relay UE detects whether a failure occurs on the link between the relay UE and the BS. The embodiment of Figure 8 assumes that a PC5 RRC connection of the link between the UE and the relay UE is established, and an RRC connection of the link between the relay UE and the BS is established.

[0076] In operation 803, if the relay UE detects that a failure occurs on the link between the relay UE and the BS, the relay UE sends a failure notification to the UE. The failure occurring on the link between the relay UE and the BS may be an RLF. For example, if the relay UE detects that an RLF occurs on the link between the relay UE and the BS, the failure notification is an RLF notification.

[0077] In one embodiment, once the relay UE completes a successful RRC re-establishment procedure, the relay UE sends a successful recovery notification.

[0078] In a further embodiment, if the relay UE detects an RRC re-establishment failure on the link between the relay UE and the BS, the relay UE sends a recovery failure notification.

[0079] In one example, the failure notification, successful recovery notification, or recovery failure notification may be: RRC signalling, Control PDUs at the SLAP layer, and · May be included in one of the MAC CEs.

[0080] Details described in all other embodiments of the present application (e.g. details of how to handle a failure on the link between the UE and the relay UE) are applicable to the embodiment of Fig. 8. Moreover, details described in the embodiment of Fig. 8 are applicable to all the embodiments of Figs. 1-7, 9 and 10.

[0081] 9 illustrates a flowchart of a method for initiating a relay reselection procedure according to some embodiments of the present application. The method may be performed by a UE (e.g., a UE 101 as illustrated and illustrated in FIG. 1, a UE (a) as illustrated and illustrated in FIG. 2, or a UE as illustrated and illustrated in FIG. 3). Although described with respect to a UE, it should be understood that other devices may be configured to perform a method similar to that of FIG. 9.

[0082] The embodiment of FIG. 9 assumes that a PC5 RRC connection has been established for a link between a UE (e.g., UE 101 as illustrated and shown in FIG. 1) and a relay UE (e.g., relay UE 103 as illustrated and shown in FIG. 1 or UE(b) as illustrated and shown in FIG. 2), an RRC connection has been established for a link between the relay UE and a BS (e.g., BS 102 as illustrated and shown in FIG. 1 or a BS as illustrated and shown in FIG. 3), and an RRC relay connection has been established for a link between the UE and the BS.

[0083] In an example method 900 as illustrated in Figure 9, a UE receives a notification associated with a failure from a relay UE in operation 901. The notification associated with the failure indicates a failure on a link between the relay UE and the BS. In one embodiment, an access stratum (AS) layer of the UE sends the notification associated with the failure to a non-access stratum (NAS) layer of the UE.

[0084] At operation 902, the UE initiates a relay reselection procedure. The relay reselection procedure may be initiated in response to a notification associated with a failure indicating that an RLF of a link between the relay UE and the BS has been detected. In one example, in response to initiating the relay reselection procedure, the UE monitors a discovery resource pool.

[0085] In one embodiment, the UE receives a successful recovery notification from the relay UE. Upon receiving the successful recovery notification, the UE may stop the relay reselection procedure or stop monitoring the discovery resource pool.

[0086] In a further embodiment, the UE receives a recovery failure notification from the relay UE. A relay reselection procedure is initiated upon receiving the recovery failure notification from the relay UE. For example, while initiating the relay reselection procedure, the UE monitors a discovery resource pool in response to receiving the recovery failure notification from the relay UE. The UE may then further select a second relay UE and establish a PC5 RRC connection of the link between the UE and the second relay UE.

[0087] In one example, each of the notifications associated with the failure, the successful recovery notification and the recovery failure notification may be included in RRC signaling, a control PDU at the SLAP layer, or a MAC CE.

[0088] Details described in all other embodiments of the present application (e.g. details of how to handle a failure on the link between the UE and the relay UE) are applicable to the embodiment of Fig. 9. Moreover, details described in the embodiment of Fig. 9 are applicable to all embodiments of Figs. 1-8 and 10.

[0089] The following text describes a specific embodiment 3 of the method as depicted and illustrated in FIGS.

[0090] EMBODIMENT 3 According to embodiment 3, a UE (e.g., a UE 101 as shown and illustrated in FIG. 1 ), a relay UE (e.g., a relay UE 103 as shown and illustrated in FIG. 1 ), and a BS (e.g., a BS 102 as shown and illustrated in FIG. 1 ) perform the following steps: (1) An RRC connection of a PC5 link between the UE 101 and the relay UE 103 is already established. An RRC connection of a Uu link between the relay UE and the BS 102 is already established. (2) A relay RRC connection is established for the link between the UE 101 and the BS 102. The RRC relay connection for the link is a logical link, and may also be named an “end-to-end link” between the UE 101 and the BS 102. (3) Relay UE 103 sends an RLF notification to UE 101 when the following conditions are met: Case 2-1: RLF between the relay UE 103 and the BS 102 occurs. (4) When UE 101 receives an RLF notification from relay UE 103: The UE 101 is triggered to monitor the discovery resource pool, and The AS layer of UE101 conveys the RLF information to the NAS layer of UE101. (5) The relay UE 103 sends a successful recovery notification upon completing the recovery procedure. After receiving the successful recovery notification, the UE 101 stops the relay reselection procedure, or After receiving the successful recovery notification, the UE 101 stops monitoring the discovery resource pool. (6) The relay UE 103 transmits a recovery failure notification to the UE 101 when a recovery failure occurs in the recovery procedure. When the UE 101 receives the recovery failure notification, the UE 101 is triggered to initiate a relay reselection procedure.

[0091] FIG. 10 illustrates a simplified block diagram of an apparatus for fault handling procedures according to some embodiments of the present application.

[0092] In some embodiments of the present application, the apparatus 1000 may be a UE (e.g., a UE 101 as illustrated and shown in FIG. 1, a UE (a) as illustrated and shown in FIG. 2, or a UE as illustrated and shown in FIG. 3) and may be capable of at least performing the method illustrated in FIG. 9.

[0093] In some other embodiments of the present application, the apparatus 1000 may be a relay UE (e.g., a relay UE 103 as illustrated and shown in FIG. 1 or a UE (b) as illustrated and shown in FIG. 2) and may perform at least the method illustrated in FIG. 7 or FIG. 8.

[0094] In some additional embodiments of the present application, the apparatus 1000 may be a BS (e.g., the BS 102 as illustrated and shown in FIG. 1 or the BS as illustrated and shown in FIG. 3) and may be capable of at least performing the method illustrated in FIG. 6.

[0095] As shown in FIG. 10, the apparatus 1000 may include at least one receiver 1002, at least one transmitter 1004, at least one non-transitory computer-readable medium 1006, and at least one processor 1008 coupled to the at least one receiver 1002, the at least one transmitter 1004, and the at least one non-transitory computer-readable medium 1006.

[0096] 10, elements such as at least one receiver 1002, at least one transmitter 1004, at least one non-transitory computer-readable medium 1006, and at least one processor 1008 are described in the singular, but the plural is contemplated unless limitation to the singular is expressly stated. In some embodiments of the present application, the at least one receiver 1002 and the at least one transmitter 1004 are combined into a single device, such as a transceiver. In some embodiments of the present application, the apparatus 1000 may further include an input device, a memory, and / or other components.

[0097] In some embodiments of the present application, at least one non-transitory computer-readable medium 1006 may store computer-executable instructions programmed to implement operations of a method, such as those described with reference to any one of Figures 5-9, by at least one receiver 1002, at least one transmitter 1004, and at least one processor 1008.

[0098] Those skilled in the art will understand that the operations of the methods described in connection with the embodiments disclosed herein may be embodied directly in hardware, in software modules executed by a processor, or in a combination of the two. The software modules may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other form of known storage medium. Additionally, in some embodiments, the operations of the methods may reside as one or any combination or set of codes and / or instructions on a non-transitory computer-readable medium and may be incorporated into a computer program product.

[0099] 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 in each figure are necessary for the operation of the disclosed embodiments. For example, a person skilled in the art will be enabled to make and use the teachings of the present disclosure by simply utilizing the elements of the independent claims. Thus, the embodiments of the present disclosure described herein are intended to be illustrative and not limiting. Various changes may be made without departing from the spirit and scope of the present disclosure.

[0100] In this document, the terms "comprise", "comprising" or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that includes a set of elements does not include only those elements, but may include other elements not specified or inherent to such process, method, article, or apparatus. An element preceded by "a", "an", etc., does not, without further constraints, preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element. Also, the term "another" is defined as at least a second or more. The terms "having" and the like, as used herein, are defined as "comprising". [Explanation of symbols]

[0101] 100 Wireless communication system 101UE 102 BS 103 Relay UE 1000 devices 1002 Receiver 1004 Transmitter 1006 Non-transitory computer readable medium 1008 Processor T400 Timer

Claims

1. A method performed by a relay user equipment (UE), comprising: receiving a radio resource control (RRC) configuration request from a UE, where a PC5 RRC connection of a link between the UE and the relay UE is established; sending an RRC setup request to a base station (BS), where an RRC connection of a link between the relay UE and the BS is established; receiving response information from the BS, the response information including at least one of a Cell Radio Network Temporary Identifier (C-RNTI) and an Identifier (ID) of the UE; sending the response information to the UE; receiving, from the UE, one or more data packets associated with different UE bearers; transmitting a SLAP PDU to the BS, the SLAP PDU including the one or more data packets; Including, a header of the SLAP PDU including one or more logical channel IDs associated with the one or more data packets, and the one or more logical channel IDs include: An ID of a logical channel between the UE and the relay UE; or the ID of a logical channel between the UE and the BS. method.

2. The method of claim 1 , wherein the at least one of the C-RNTI and the ID of the UE is used in a Sidelink Adaptation Protocol (SLAP) layer header of the relay UE.

3. receiving an RRC configuration complete message from the UE; sending the RRC setup complete message to the BS; The method of claim 1, further comprising:

4. The response information is A mapping association between the C-RNTI and the ID of the UE; and configuration information of the SLAP layer of the relay UE.

5. The method of claim 1 , wherein the response information includes an ID of a logical channel between the UE and the BS.

6. The response information is a mapping association between an ID of a logical channel between the UE and the relay UE and an ID of a logical channel between the relay UE and the BS; The method of claim 1, comprising one of a mapping association between the ID of the logical channel between the UE and the relay UE and an ID of a logical channel between the UE and the BS.

7. A method performed by a base station (BS), comprising: receiving a radio resource control (RRC) configuration request from a relay user equipment (UE), where a PC5 RRC connection for a link between the UE and the relay UE is established, and an RRC connection for a link between the relay UE and the BS is established; sending response information to the relay UE, the response information including at least one of a Cell Radio Network Temporary Identifier (C-RNTI) and an Identifier (ID) of the UE; receiving a Sidelink Adaptation Protocol (SLAP) PDU from the relay UE, the SLAP PDU including one or more packets associated with different UE bearers, and the one or more packets being transmitted from the UE; a header of the SLAP PDU including one or more logical channel IDs associated with the one or more packets, and the one or more logical channel IDs include: An ID of a logical channel between the UE and the relay UE; or the ID of a logical channel between the UE and the BS. method.

8. receiving an RRC setup complete message from the relay UE, the RRC setup complete message being sent from the UE to the relay UE; The method of claim 7, further comprising:

9. The method of claim 7, wherein the response information includes a mapping association between the C-RNTI and the ID of the UE.

10. The method of claim 7, wherein the response information includes an ID of a logical channel between the UE and the BS.

11. The response information is a mapping association between an ID of a logical channel between the UE and the relay UE and an ID of a logical channel between the relay UE and the BS; The method of claim 7, comprising one of a mapping association between the ID of the logical channel between the UE and the relay UE and an ID of a logical channel between the UE and the BS.

12. at least one non-transitory computer-readable medium storing computer-executable instructions; at least one receiving circuitry; at least one transmission circuitry; at least one processor coupled to the at least one non-transitory computer readable medium, the at least one receiving circuitry, and the at least one transmitting circuitry; The computer executable instructions cause the at least one processor to implement a method according to any one of claims 1 to 6. Device.

13. at least one non-transitory computer-readable medium storing computer-executable instructions; at least one receiving circuitry; at least one transmission circuitry; at least one processor coupled to the at least one non-transitory computer readable medium, the at least one receiving circuitry, and the at least one transmitting circuitry; The computer executable instructions cause the at least one processor to implement a method according to any one of claims 7 to 11. Device.

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