Method executed by user equipment and user equipment

Abstract

The invention provides a method executed by user equipment and the user equipment. The method comprises the following steps that: UE (User Equipment) receives a message containing indication information, wherein the indication information is used for indicating the change of sidewalk communication connection or sidewalk communication bearing corresponding to a certain target; the UE triggers a flow corresponding to the change according to the indication information; and the UE judges the type of the sidewalk communication connection or the sidewalk communication bearer and / or the association condition with the RLC channel or the RLC entity in the flow, and performs corresponding processing on the RLC layer and / or the MAC layer according to the type of the sidewalk communication connection or the sidewalk communication bearer and / or the association condition with the RLC channel or the RLC entity. Therefore, when the end-to-end connection and bearer between the remote UE are changed, the UE can correctly process the RLC layer and the MAC layer between the remote UE and the relay UE, thereby avoiding abnormity, and reducing the influence on the service performance.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technologies. More specifically, the present invention relates to a communication method based on a UE-to-UE sidelink communication relay architecture performed by a user equipment and a corresponding user equipment. Background Art

[0002] In March 2020, at the 91st plenary session of RAN, a work item on NR sidelink relaying for Release 17 was proposed (see non-patent literature: RP-210904 New Study Item on NR SidelinkRelaying) and approved. The latest version of this work item can be seen in non-patent literature: RP-212601reivised WIDNR sidelink relay. One of the objectives of this work item is to standardize the sidelink communication control plane procedures, such as the management of RRC connections, the reception of system messages, and the reception of paging. The objectives of this work item also include standardizing the selection and reselection procedures of sidelink communication relay UEs.

[0003] In December 2021, at the 94th plenary session of RAN, a work item on NR sidelink relay enhancements for Release 18 was proposed (see non-patent literature: RP-213585New WID on NRsidelink relay enhancements) and approved. The latest version of this work item can be seen in non-patent literature: RP-221262Revised WID on NR sidelink relay enhancements. One of the objectives of this work item is to standardize the control plane procedures of the U2U (UE-to-UE) relay architecture. In the U2U relay architecture, two remote UEs perform sidelink communication through a relay UE.

[0004] When the end-to-end connection and bearer between the remote UEs change, how to handle the RLC layer and MAC layer between the remote UEs and the relay UE is a problem that needs to be solved. Summary of the Invention

[0005] To solve at least a part of the above problems, the present invention provides a method performed by a user equipment and a user equipment, where when the end-to-end connection and bearer change, the UE processes the RLC layer and MAC layer between the remote UE and the relay UE.

[0006] According to a first aspect of the present invention, there is provided a method performed by a user equipment UE, including: the UE receives a message including indication information for indicating a change in a sidelink communication connection or a sidelink communication bearer corresponding to a certain target; the UE triggers a process corresponding to the change according to the indication information; the UE determines a type of the sidelink communication connection or the sidelink communication bearer and / or an association status with an RLC channel or an RLC entity in the process, and performs corresponding processing on an RLC layer and / or a MAC layer according to the type of the sidelink communication connection or the sidelink communication bearer and / or the association status with the RLC channel or the RLC entity.

[0007] According to a second aspect of the present invention, there is provided a user equipment, including: a processor; and a memory storing instructions, wherein the instructions, when run by the processor, perform the above method.

[0008] Advantages of the Invention

[0009] According to the present invention, when an end-to-end connection and bearer between remote UEs change, the UE can correctly process the RLC layer and the MAC layer between the remote UE and the relay UE, avoid generating anomalies, and thus reduce the impact on service performance. Description of the Drawings

[0010] Figure 1 is a schematic diagram showing relay forwarding between remote UEs through a relay UE.

[0011] Figure 2 is a schematic diagram showing a control plane protocol stack of a remote UE and a relay UE in an L2 U2U sidelink communication relay architecture.

[0012] Figure 3 is a schematic diagram showing a user plane protocol stack of a remote UE and a relay UE in an L2 U2U sidelink communication relay architecture.

[0013] Figure 4 is a flowchart of a method performed by a user equipment according to the present invention.

[0014] Figure 5 is a flowchart of a method performed by a user equipment according to Embodiment 1 of the present invention.

[0015] Figure 6 is a flowchart of a method performed by a user equipment according to Embodiment 2 of the present invention.

[0016] Figure 7 is a flowchart of a method performed by a user equipment according to Embodiment 3 of the present invention.

[0017] Figure 8It is a flowchart of the method executed by a user equipment according to Embodiment 4 of the present invention.

[0018] Figure 9 It is a flowchart of the method executed by a user equipment according to Embodiment 5 of the present invention.

[0019] Figure 10 It is a flowchart of the method executed by a user equipment according to Embodiment 6 of the present invention.

[0020] Figure 11 It is a flowchart of the method executed by a user equipment according to Embodiment 7 of the present invention.

[0021] Figure 12 It is a simplified structural block diagram of a user equipment UE according to the present invention. Detailed implementation manners

[0022] The present invention will be elaborated in detail below in conjunction with the accompanying drawings and specific implementation manners. It should be noted that the present invention should not be limited to the specific implementation manners described below. Additionally, for the sake of simplicity, the detailed descriptions of well-known technologies that have no direct relevance to the present invention are omitted to prevent confusion in the understanding of the present invention.

[0023] Some terms related to the present invention are described below. For the specific meanings of the terms, refer to the latest 3GPP standard specifications.

[0024] UE: User Equipment, user equipment

[0025] NR: New Radio, new generation wireless technology

[0026] PHY: physical layer, physical layer

[0027] MAC: Medium Access Control, multimedia access control

[0028] RLC: Radio Link Control, radio link control

[0029] SDAP: Service Data Adaptation Protocol, service data adaptation protocol

[0030] PDCP: Packet Data Convergence Protocol, packet data convergence protocol

[0031] SRAP: Sidelink Relay Adaptation Protocol, sidelink communication relay adaptation protocol

[0032] RRC: Radio Resource Control, Radio Resource Control

[0033] RRC CONNECTED: RRC Connected State

[0034] RRC INACTIVE: RRC Inactive State

[0035] RRC IDLE: RRC Idle State

[0036] RAN: Radio Access Network, Radio Access Network

[0037] NG-RAN: NG Radio Access Network, Next Generation Radio Access Network

[0038] gNB: the next Generation Node B, Next Generation Base Station

[0039] Sidelink: Sidelink Communication, Sidelink

[0040] SL: Sidelink, Sidelink Communication, Sidelink

[0041] SCI: Sidelink Control Information, Sidelink Communication Control Information

[0042] AS: Access Stratum, Access Stratum

[0043] IE: Information Element, Information Element

[0044] CE: Control Element, Control Element

[0045] MIB: Master Information Block, Master Information Block

[0046] SIB: System Information Block, System Information Block

[0047] DCI: Downlink Control Information, Downlink Control Information

[0048] RB: radio bearer, Radio Bearer

[0049] DRB: Data Radio Bearer, Data Radio Bearer

[0050] SRB: Signalling Radio Bearer, Signalling Radio Bearer

[0051] Uu: Air interface

[0052] ProSe: Proximity based Services: Proximity Services

[0053] V2X: Vehicle-to-Everything, Vehicle-to-Everything

[0054] NAS: Non-Access-Stratum, Non-Access-Stratum

[0055] PC5-S: PC5 signalling, PC5 signalling

[0056] SL-SRB: Sidelink Signalling Radio Bearer, Sidelink Signalling Radio Bearer

[0057] SL-DRB: Sidelink Data Radio Bearer, Sidelink Data Radio Bearer

[0058] U2U: UE-to-UE, UE-to-UE

[0059] U2N: UE-to-Network, UE-to-Network

[0060] L2: Layer 2, Layer 2 architecture

[0061] RSRP: Reference Signal Received Power, Reference Signal Received Power

[0062] SL-RSRP: Sidelink RSRP, Sidelink RSRP

[0063] SD-RSRP: sidelink discovery RSRP, sidelink discovery RSRP

[0064] SpCell: Special Cell, Special Cell, including PCell and PSCell

[0065] PCell: Primary Cell, Primary Cell

[0066] PSCell: Primary SCG Cell, SCG Primary Cell

[0067] L2-ID: Layer-2 ID(identity), Layer-2 identity

[0068] 3GPP: 3rd Generation Partnership Project, the Third Generation Partnership Project

[0069] In the present invention, the network (network or NW), base station (base station or gNB or eNB), and RAN can be used interchangeably. The network can be a Long-Term Evolution (LTE) network, a New Radio Access Technology (New RAT, NR) network, an enhanced Long-Term Evolution (eLTE) network, or other networks defined in subsequent evolved versions of 3GPP. The base station in the present invention can be any type of base station, including Node B, enhanced base station eNB, and base station gNB in a 5G communication system; or micro base station, pico base station, macro base station, home base station, etc. The network generally refers to a base station or a cell. The cell can also be a cell under any of the above types of base stations. Unless otherwise specified, the cell, beam, and Transmission Point (TRP) can be used interchangeably, and the base station can also be the central unit (gNB-Central Unit, gNB-CU) or distributed unit (gNB-Distributed Unit, gNB-DU) that makes up the base station.

[0070] In the present invention, the User Equipment (UE) can refer to the NR device supporting the NR Sidelink relay function described in the background art, or the NR device supporting the L2 U2U relay function, or other types of NR devices or LTE devices.

[0071] In the present invention, sidelink, SL, and PC5 can be used interchangeably.

[0072] In the present invention, unless otherwise specified, "Relay UE", "U2U Relay UE", and "L2 U2U Relay UE" can be used interchangeably. Unless otherwise specified, "Remote UE", "U2U Remote UE", and "L2 U2U Remote UE" can be used interchangeably.

[0073] In the present invention, "change" and "update" can be used interchangeably.

[0074] In the present invention, "configure", "set", and "present" can be used interchangeably.

[0075] In the present invention, the terms "used", "available", "active", "applied", "performed", "enabled" can be used interchangeably.

[0076] In the present invention, the terms "use", "be available", "apply", "implement", "enable", "active", "perform", "d0", etc. can be used interchangeably.

[0077] In the present invention, the terms "feedback", "submit", "report", "send", "transmit (or transport)", "inform", "indicate", "provide" can be used interchangeably.

[0078] In the present invention, the terms "trigger" and "initiate" can be used interchangeably.

[0079] In the present invention, the terms "associate", "correspond", "map" can be used interchangeably.

[0080] In the present invention, the upper layer may refer to the ProSe layer, or the V2X layer, or the NAS layer, or the PC5-S protocol layer, or a layer above the RRC layer. In the present invention, the ProSe layer, the V2X layer, the NAS layer and the PC5-S protocol layer can be used interchangeably.

[0081] In the present invention, the term "channel" may refer to a single channel or multiple channels.

[0082] In the present invention, the terms "PC5 RLC channel" and "PC5 Relay RLC channel" can be used interchangeably.

[0083] In the present invention, both "first hop" and "second hop" can be modified by "PC5", that is, both "first hop" and "second hop" are based on the PC5 interface.

[0084] In the present invention, unless otherwise specified, "remote UE" may refer to the source-side remote UE and / or the target-side remote UE. "Target-side remote UE" and "peer remote UE" may be used interchangeably.

[0085] It should be noted that in this specification, the two connected by "and", "or", and "and / or" may represent different expression methods of the same meaning in different application scenarios, and there may be an inclusion relationship between them, not necessarily referring to completely different contents.

[0086] The related technologies of the present invention are described below.

[0087] PC5 Interface

[0088] The PC5 interface is an interface for control plane and user plane Sidelink communication between UEs. For Sidelink unicast, the PC5-RRC connection is an AS layer logical connection between a pair of source layer 2 IDs and target layer 2 IDs. The upper layer establishes a PC5 unicast link for Sidelink unicast communication, and the establishment of a PC5 unicast link corresponds to the establishment of a PC5-RRC connection.

[0089] Uu Interface

[0090] The Uu interface is a wireless communication interface between the UE and the base station. The UE can communicate with the gNB using NR on the Uu interface.

[0091] L2 Architecture

[0092] The L2 architecture is relative to the L3 architecture. In the L2 architecture, the selection and reselection of relays and the communication of the UE with the network or another UE through the relay need to be controlled or participated in by the access layer. In the L3 architecture, the access layer is basically unaware of the existence of the relay, or the relay is transparent to the access layer.

[0093] UE-to-UE relay is as Figure 1 shown. The remote UEs are on the left and right sides, and the relay UE is in the middle. The remote UEs and the relay UE are respectively connected through the PC5 interface. Since the two remote UEs are far apart or the communication environment is poor, the relay UE needs to relay and forward the signaling and data between them.

[0094] The scenarios of UE-to-UE relay include:

[0095] 1) Within the coverage area: Both remote UEs and the relay UE are within the coverage area;

[0096] 2) Outside the coverage area: Both of the two remote UEs and the relay UE are outside the coverage area;

[0097] 3) Partial coverage: Among the two remote UEs and the relay UE, at least one UE is within the coverage area and at least one UE is outside the coverage area.

[0098] For the NR Sidelink L2 U2U relay architecture, one of the two remote UEs can be called the source-side remote UE, and the other can be called the target-side remote UE; or one is called the remote UE and the other is called the peer remote UE. When transmitting data / signaling between the two remote UEs, the transmitting remote UE of the data / signaling can be called the source-side remote UE, and the receiving UE of the data / signaling is called the target-side remote UE; or, the transmitting remote UE of the data / signaling is called the remote UE, and the receiving UE of the data / signaling is called the peer remote UE. The connection / link between the source-side remote UE and the relay UE, or the connection / link with the remote UE as the transmitter and the relay UE as the receiver can be called the first hop. The connection / link between the relay UE and the peer remote UE (or target-side remote UE), or the connection / link with the relay UE as the transmitter and the remote UE as the receiver can be called the second hop.

[0099] The two remote UEs respectively establish PC5-RRC connections with the relay UE. The PC5-RRC connection between the remote UE and the relay UE can be called the per-hop PC5-RRC connection, that is, there are two per-hop PC5-RRC connections: the first hop PC5-RRC connection and the second hop PC5-RRC connection. A PC5-RRC connection is also established between the two remote UEs (via the relay UE), which can be called the end-to-end PC5-RRC connection.

[0100] In the L2 U2U relay architecture, the upper layer establishes a PC5 unicast link between the two remote UEs (via the relay UE) (subsequently, the AS layer also establishes a PC5-RRC connection), which can be called the end-to-end PC5 unicast link. The upper layer also establishes PC5 unicast links between the two remote UEs and the relay UE respectively. The PC5 unicast link between the remote UE and the relay UE can be called the per-hop PC5 unicast link. When the upper layer releases the PC5 unicast link between the UE and the target UE, it will require the AS layer to release the PC5-RRC connection corresponding to this PC5 unicast link.

[0101] For the layer two (L2) U2U sidelink communication relay architecture, the control plane protocol stacks of the remote UE and the relay UE are as Figure 2as shown

[0102] For the layer 2 (L2) U2U side link communication relay architecture, the user plane protocol stacks of the remote UE and the relay UE are as Figure 3 shown

[0103] To carry the control plane signaling between remote UEs, an SL-SRB needs to be established between the remote UE and the peer remote UE. The SL-SRB between the remote UE and the peer remote UE (i.e., between two remote UEs) can be called an end-to-end SL-SRB. To carry the control plane signaling between the remote UE and the relay UE, an SL-SRB also needs to be established between the remote UE and the relay UE, which can be called a per-hop SL-SRB. To carry the user plane data between remote UEs, an SL-DRB needs to be established between the remote UE and the peer remote UE. The SL-DRB between the remote UE and the peer remote UE (i.e., between two remote UEs) can be called an end-to-end SL-DRB. To carry the user plane data between the remote UE and the relay UE, an SL-DRB also needs to be established between the remote UE and the relay UE, which can be called a per-hop SL-DRB.

[0104] The PC5 relay RLC channel refers to the RLC channel between the remote UE and the relay UE that forwards signaling and data for L2 U2U relay through the PC5 interface. In the L2 U2U relay architecture, when two remote UEs are connected through the relay UE, the PC5 relay RLC channel between the remote UE and the relay UE is used to carry the data and signaling between the two remote UEs, that is, to carry the end-to-end SL-SRB and end-to-end SL-DRB. The PC5 relay RLC channel on the first hop can be called the first-hop PC5 relay RLC channel (or the source-side PC5 relay RLC channel), and the PC5 relay RLC channel on the second hop can be called the second-hop PC5 relay RLC channel (or the target-side PC5 relay RLC channel). The remote UE configures the first-hop PC5 relay RLC channel for the relay UE, and the relay UE configures the second-hop PC5 relay RLC channel for the peer remote UE. The data / signaling sent from one remote UE to multiple peer remote UEs can be multiplexed on the same first-hop PC5 relay RLC channel, and the data / signaling sent to one peer remote UE from multiple remote UEs can be multiplexed on the same second-hop PC5 relay RLC channel.

[0105] The PC5-SRAP entity refers to the SRAP entity used for PC5 interface communication. PC5-SRAP is the adaptation layer for the L2 U2U architecture. In the L2 U2U relay architecture, when two remote UEs are connected through a relay UE, the PC5-SRAP of the remote UE determines the PC5 relay RLC channel corresponding to the uplink data / signaling (data sent by the remote UE to the peer remote UE) according to the configured mapping relationship between the end-to-end bearer and the PC5 relay RLC channel, and determines the PC5 relay RLC channel corresponding to the downlink data from the peer remote UE and forwarded by the relay UE. There is also a PC5-SRAP entity in the relay UE for data routing. The PC5-SRAP also exists in the peer remote UE, and its function is the same as that of the PC5-SRAP in the source-side UE. In this article, the terms "entity" and "layer" can be used interchangeably, such as the SRAP entity or the SRAP layer.

[0106] When the sidelink communication RLC entity indicates that a certain target has reached the maximum number of retransmissions, or when the T400 timer for a certain target times out, or when the MAC entity indicates that the HARQ DTX for a certain target has reached the maximum number of retransmissions, or when the sidelink PDCP entity indicates that the integrity check of the SL-SRB2 or SL-SRB3 for a certain target fails, the UE considers that the sidelink radio link failure for the said target is detected, and releases the PC5-RRC connection for the said target.

[0107] This invention discusses how to handle the RLC layer and MAC layer between the remote UE and the relay UE when the end-to-end connection and bearer between the remote UEs change. Figure 4 It is a flowchart of the method executed by the user equipment involved in this invention, as Figure 4 shown. In the first step, the UE receives a message containing indication information, which is used to indicate the change of the sidelink communication connection or sidelink communication bearer corresponding to a certain target; in the second step, the UE triggers the process corresponding to the change according to the said indication information; in the third step, the UE judges the type of the sidelink communication connection or sidelink communication bearer and / or the association status with the RLC channel or RLC entity in the said process, and performs corresponding processing on the RLC layer and / or MAC layer according to the type of the sidelink communication connection or sidelink communication bearer and / or the association status with the RLC channel or RLC entity. Through this invention, the UE can correctly handle the RLC layer and MAC layer between the remote UE and the relay UE, avoid generating anomalies, and thus reduce the impact on service performance.

[0108] Hereinafter, several embodiments of this invention for the above problems will be described in detail.

[0109] Embodiment 1

[0110] Figure 5 FIG. 5 is a flowchart of a method executed by a user equipment according to Embodiment 1 of the present invention.

[0111] Optionally, in step 101, the UE receives a PC5-RRC message (sent by the peer UE), such as a RRCReconfigurationSidelink message for sidelink communication. Optionally, the RRCReconfigurationSidelink message contains SL-DRB release information for indicating the release of the SL-DRB.

[0112] Optionally, in step 103, the UE triggers the SL-DRB release process according to the SL-DRB release information in the RRCReconfigurationSidelink message.

[0113] Optionally, in step 105, the UE processes the RLC layer in the SL-DRB release process.

[0114] Optionally, the UE determines at least one of the following first conditions:

[0115] - The SL-DRB is a per-hop SL-DRB;

[0116] - The SL-DRB is not an end-to-end SL-DRB;

[0117] - No (any) SL-DRB is associated with the RLC channel (or RLC entity) associated with the SL-DRB;

[0118] - No (any) other SL-DRB except the SL-DRB is associated with the RLC channel (or RLC entity) associated with the SL-DRB.

[0119] Optionally, when at least one of the above first conditions is met, the UE releases the RLC entity and / or the corresponding logical channel associated with the SL-DRB. Optionally, the UE performs the first condition determination only when the SL-DRB release is triggered by receiving the RRCReconfigurationSidelink message.

[0120] Optionally, the UE determines at least one of the following second conditions:

[0121] - The SL-DRB is an end-to-end SL-DRB;

[0122] - The SL-DRB is not a per-hop SL-DRB;

[0123] - There is no end-to-end SL-DRB associated with the PC5 Relay RLC channel associated with the SL-DRB;

[0124] - There is no other end-to-end SL-DRB other than the SL-DRB associated with the PC5 Relay RLC channel associated with the SL-DRB;

[0125] Optionally, when at least one of the above second conditions is met, the UE performs the release of the PC5 Relay RLC channel (associated with the SL-DRB). Optionally, the release of the PC5 Relay RLC channel includes: releasing the RLC entity associated with the PC5 Relay RLC channel and / or the corresponding logical channel. Optionally, the UE performs the second condition judgment only when the SL-DRB release is triggered by receiving the RRCReconfigurationSidelink message.

[0126] Optionally, in this embodiment, if the UE is an L2 U2U remote UE, the peer UE is a peer L2 U2U Remote UE or an L2 U2U Relay UE; if the UE is an L2 U2U Relay UE, the peer UE is an L2 U2U remote UE or a peer L2 U2U Remote UE.

[0127] Embodiment 2

[0128] Figure 6 It is a flowchart of a method performed by a user equipment according to Embodiment 2 of the present invention.

[0129] Optionally, in step 201, the UE receives SL-DRB configuration information. Among them, the SL-DRB configuration information may be included in a system message (such as SIB12), or a dedicated RRC message (such as an RRCReconfiguration message), or NR sidelink pre-configuration information. Optionally, the SL-DRB configuration information is included in the sidelink communication NR dedicated configuration (sl-ConfigDedicatedNR) cell in the RRCReconfiguration message.

[0130] Optionally, in step 203, the UE determines whether to release the SL-DRB. For example, if there is no data to be transmitted for the sidelink QoS flow mapped to the SL-DRB configured by the SL-DRB configuration information, it is determined that the SL-DRB is to be released.

[0131] Optionally, in step 205, the UE sends an RRCReconfigurationSidelink message to the peer UE, which includes SL-DRB release information for indicating the release of the SL-DRB.

[0132] Optionally, in step 207, the UE receives the RRCReconfigurationCompleteSidelink message (sent by the peer UE), triggering the release process of the SL-DRB determined to be released in step 203.

[0133] Optionally, in step 209, the UE processes the RLC layer in the SL-DRB release process.

[0134] Optionally, the UE judges at least one of the first conditions. When at least one of the first conditions is satisfied, the UE releases the RLC entity associated with the SL-DRB and / or the corresponding logical channel. Optionally, after receiving the RRCReconfigurationCompleteSidelink message, if the SL-DRB release is triggered by the configuration in the system message (or proprietary RRC message, or NR sidelink pre-configuration information), the UE performs the first condition judgment.

[0135] Optionally, the UE judges at least one of the second conditions. When at least one of the second conditions is satisfied, the UE performs the release of the PC5 Relay RLC channel (associated with the SL-DRB). Optionally, the release of the PC5 Relay RLC channel includes: releasing the RLC entity associated with the PC5 Relay RLC channel and / or the corresponding logical channel. Optionally, after receiving the RRCReconfigurationCompleteSidelink message, if the SL-DRB release is triggered by the configuration in the system message (or proprietary RRC message, or NR sidelink pre-configuration information), the UE performs the second condition judgment.

[0136] Among them, the first condition is the same as the first condition in Embodiment 1, and the second condition is the same as the second condition in Embodiment 1.

[0137] Optionally, in this embodiment, if the UE is an L2 U2U remote UE, the peer UE is a peer L2 U2U Remote UE or an L2 U2U Relay UE; if the UE is an L2 U2U Relay UE, the peer UE is an L2 U2U remote UE or a peer L2 U2U Remote UE.

[0138] Embodiment 3

[0139] Figure 7 It is a flowchart of a method executed by a user equipment according to Embodiment 3 of the present invention.

[0140] Optionally, in step 301, if the UE (AS layer or RRC layer) is required by the upper layer(s) to release the PC5-RRC connection for a certain target (UE or layer 2 ID), and / or if the UE detects a sidelink communication radio link failure for a certain target, the UE releases the PC5-RRC connection corresponding to the target.

[0141] Optionally, in step 303, the UE triggers the (one or more) SL-DRB release procedures associated with the PC5-RRC connection.

[0142] Optionally, in step 305, the UE processes the RLC layer in the SL-DRB release procedure.

[0143] Optionally, for each SL-DRB of the target, the UE determines at least one of the first conditions. When at least one of the first conditions is met, the UE releases the RLC entity and / or the corresponding logical channel associated with the SL-DRB of the target. Optionally, the UE performs the first condition determination only when the UE detects a sidelink communication radio link failure of the target and / or when the UE is required by the upper layer(s) to release the PCR-RRC connection for the target.

[0144] Optionally, for each SL-DRB of the target, the UE determines at least one of the second conditions, and when at least one of the second conditions is met, the UE performs the PC5 Relay RLC channel release (associated with the SL-DRB of the target). Optionally, the PC5 Relay RLC channel release includes: releasing the RLC entity associated with the PC5 Relay RLC channel and / or the corresponding logical channel. Optionally, the UE performs the second condition determination only when the UE detects a sidelink communication radio link failure of the target and / or when the UE is required by the upper layer(s) to release the PCR-RRC connection for the target.

[0145] Among them, the first condition is the same as the first condition in Embodiment 1, and the second condition is the same as the second condition in Embodiment 1.

[0146] Optionally, in this embodiment, if the UE is an L2 U2U remote UE, the peer UE is a peer L2 U2U Remote UE or an L2 U2U Relay UE; if the UE is an L2 U2U Relay UE, the peer UE is an L2 U2U remote UE or a peer L2 U2U Remote UE.

[0147] Embodiment 4

[0148] Figure 8 is a flowchart of the method performed by the user equipment involved in Embodiment 4 of the present invention.

[0149] Optionally, in step 401, the UE receives a PC5-RRC message (sent by the peer UE), such as a sidelink communication RRC reconfiguration (RRCReconfigurationSidelink) message. Optionally, the RRCReconfigurationSidelink message contains SL-DRB modification information for indicating the modification of the SL-DRB.

[0150] Optionally, in step 403, according to the SL-DRB modification information in the RRCReconfigurationSidelink message, the UE triggers the SL-DRB modification process.

[0151] Optionally, in step 405, the UE processes the RLC layer in the SL-DRB modification process.

[0152] Optionally, the UE determines at least one of the first conditions, and when at least one of the first conditions is met, the UE reconfigures the RLC entity associated with the SL-DRB and / or the corresponding logical channel. Optionally, the UE performs the determination of the first conditions only when the modification of the SL-DRB is triggered by receiving an RRCReconfigurationSidelink message.

[0153] Optionally, the UE determines at least one of the second conditions, and when at least one of the second conditions is met, the UE performs the modification of the PC5 Relay RLC channel (associated with the SL-DRB). Optionally, the modification of the PC5 Relay RLC channel includes: reconfiguring the RLC entity associated with the PC5 Relay RLC channel and the corresponding logical channel. Optionally, the UE performs the determination of the second conditions only when the modification of the SL-DRB is triggered by receiving an RRCReconfigurationSidelink message.

[0154] Among them, the first condition is the same as the first condition in Embodiment 1, and the second condition is the same as the second condition in Embodiment 1.

[0155] Optionally, in this embodiment, if the UE is an L2 U2U remote UE, the peer UE is a peer L2 U2U Remote UE or an L2 U2U Relay UE; if the UE is an L2 U2U Relay UE, the peer UE is an L2 U2U remote UE or a peer L2 U2U Remote UE.

[0156] Embodiment 5

[0157] Figure 9 is a flowchart of the method performed by a user equipment according to Embodiment 5 of the present invention.

[0158] Optionally, in step 501, the UE receives SL-DRB configuration information. Among them, the SL-DRB configuration information may be included in a system message (such as SIB12), or a dedicated RRC message (such as an RRCReconfiguration message), or NR sidelink pre-configuration information. Optionally, the SL-DRB configuration information is included in the sidelink communication NR dedicated configuration (sl-ConfigDedicatedNR) cell in the RRCReconfiguration message.

[0159] Optionally, in step 503, the UE determines whether the SL-DRB needs to be modified. For example, if any of the parameters related to the established SL-DRB are modified (e.g., modified by the SL-DRB configuration information), it is determined that the SL-DRB needs to be modified.

[0160] Optionally, in step 505, the UE sends an RRCReconfigurationSidelink message to the peer UE, which contains SL-DRB modification information for indicating the modification of the SL-DRB.

[0161] Optionally, in step 507, the UE receives the RRCReconfigurationCompleteSidelink message (sent by the peer UE), triggering the modification process of the SL-DRB determined to need modification in step 503.

[0162] Optionally, in step 509, the UE processes the RLC layer in the SL-DRB modification process.

[0163] Optionally, the UE judges at least one of the first conditions. When at least one of the first conditions is met, the UE reconfigures the RLC entity associated with the SL-DRB and / or the corresponding logical channel. Optionally, after receiving the RRCReconfigurationCompleteSidelink message, the UE performs the first condition judgment only if the SL-DRB modification is triggered by the configuration in the system message (or the dedicated RRC message, or the NR sidelink pre-configuration information).

[0164] Optionally, the UE judges at least one of the second conditions. When at least one of the second conditions is met, the UE performs the PC5 Relay RLC channel modification (associated with the SL-DRB). Optionally, the PC5 Relay RLC channel modification includes: reconfiguring the RLC entity associated with the PC5 Relay RLC channel and / or the corresponding logical channel. Optionally, after receiving the RRCReconfigurationCompleteSidelink message, the UE performs the second condition judgment only if the SL-DRB modification is triggered by the configuration in the system message (or the dedicated RRC message, or the NR sidelink pre-configuration information).

[0165] Among them, the first condition is the same as the first condition in Embodiment 1, and the second condition is the same as the second condition in Embodiment 1.

[0166] Optionally, in this embodiment, if the UE is an L2 U2U remote UE, the peer UE is a peer L2 U2U Remote UE or an L2 U2U Relay UE; if the UE is an L2 U2U Relay UE, the peer UE is an L2 U2U remote UE or a peer L2 U2U Remote UE.

[0167] Embodiment 6

[0168] Figure 10 It is a flowchart of a method executed by a user equipment according to Embodiment 6 of the present invention.

[0169] Optionally, in step 601, if the UE (AS layer or RRC layer) is required by the upper layer(s) to release the PC5-RRC connection for a certain target (UE or layer 2 ID), and / or if the UE (AS layer or RRC layer) is required by the upper layer(s) to terminate the PC5-S transmission for a certain target (UE or layer 2 ID), and / or if the UE detects a sidelink communication radio link failure for a certain target, the UE releases the PC5-RRC connection corresponding to the target.

[0170] Optionally, in step 603, the UE triggers the (one or more) SL-SRB release process for the PC5-RRC message, and / or triggers the (one or more) SL-SRB release process for the PC5-S message.

[0171] Optionally, in step 605, the UE processes the RLC layer in the SL-SRB release process. Optionally, the SL-SRB is an SL-SRB for the PC5-RRC message, and / or the SL-SRB is an SL-SRB for the PC5-S message.

[0172] Optionally, the UE determines at least one of the following third conditions:

[0173] - The SL-SRB is a per-hop SL-SRB;

[0174] - The SL-SRB is not an end-to-end SL-SRB;

[0175] - There is no (any) SL-SRB associated with the RLC channel (or RLC entity) associated with the SL-SRB;

[0176] - There is no (any) other SL-SRB other than the SL-SRB associated with the RLC channel (or RLC entity) associated with the SL-SRB;

[0177] - The PC5-RRC connection is a per-hop PC5-RRC connection;

[0178] - The PC5-RRC connection is not an end-to-end PC5-RRC connection;

[0179] - The PC5-S message is a per-hop PC5-S message;

[0180] - The PC5-S message is not an end-to-end PC5-S message.

[0181] Optionally, when at least one of the above third conditions is met, the UE releases the RLC entity associated with the SL-SRB and / or the corresponding logical channel. Optionally, the UE performs the third condition judgment only when the UE detects a failure of the target sidelink communication radio link, and / or when the UE is required by the upper layer(s) to release the PC5-RRC connection for the target, and / or when the UE (AS layer or RRC layer) is required by the upper layer(s) to terminate the PC5-S transmission for a certain target (UE or layer 2 ID).

[0182] Optionally, the UE judges at least one of the following fourth conditions:

[0183] - The SL-SRB is an end-to-end SL-SRB;

[0184] - The SL-SRB is not a per-hop SL-SRB;

[0185] - There is no (any) end-to-end SL-SRB associated with the PC5 RelayRLC channel associated with the SL-SRB;

[0186] - There is no (any) other end-to-end SL-SRB other than the SL-SRB associated with the PC5 Relay RLC channel associated with the SL-SRB;

[0187] - The PC5-RRC connection is an end-to-end PC5-RRC connection;

[0188] - The PC5-RRC connection is not a per-hop PC5-RRC connection;

[0189] - The PC5-S message is an end-to-end PC5-S message;

[0190] - The PC5-S message is not a per-hop PC5-S message.

[0191] Optionally, when at least one of the above fourth conditions is met, the UE performs the release of the PC5 Relay RLC channel (associated with the SL-SRB). Optionally, the release of the PC5 Relay RLC channel includes: releasing the RLC entity associated with the PC5 Relay RLC channel and / or the corresponding logical channel. Alternatively, optionally, when performing the release of the PC5 Relay RLC channel, the UE determines at least one of the fourth conditions, and when at least one of the fourth conditions is met, releases the RLC entity associated with the PC5 Relay RLC channel and / or the corresponding logical channel. Optionally, the UE performs the determination of the fourth conditions only when the UE detects the failure of the target sidelink communication radio link, and / or when the UE is required by the upper layer(s) to release the PC5-RRC connection for the target, and / or when the UE (at the AS layer or RRC layer) is required by the upper layer(s) to terminate the PC5-S transmission for a certain target (UE or layer 2 ID).

[0192] Optionally, in this embodiment, if the UE is an L2 U2U remote UE, the peer UE is a peer L2 U2U Remote UE or an L2 U2U Relay UE; if the UE is an L2 U2U Relay UE, the peer UE is an L2 U2U remote UE or a peer L2 U2U Remote UE.

[0193] Embodiment 7

[0194] Figure 11 It is a flowchart of a method performed by a user equipment according to Embodiment 7 of the present invention.

[0195] Optionally, in step 701, if the upper layer(s) requires the transmission of a PC5-S message for a certain target on the SL-SRB, or if the upper layer(s) indicates the establishment of a PC5-RRC connection, the UE adds (or establishes) the SL-SRB.

[0196] Optionally, in step 703, the UE processes the RLC layer in the SL-SRB addition (or establishment) process. Optionally, the SL-SRB is an SL-SRB for PC5-RRC messages and / or an SL-SRB for PC5-S messages.

[0197] Optionally, the UE determines at least one of the third conditions. When at least one of the third conditions is met, the UE establishes the associated RLC entity and / or the corresponding logical channel for the SL-SRB for the PC5-RRC message, and / or the UE establishes the associated RLC entity and / or the corresponding logical channel for the SL-SRB for the PC5-S message. Optionally, the UE determines the third conditions only when the upper layer(s) requests to transmit a PC5-S message for a certain target on the SL-SRB, or when the upper layer(s) indicates the establishment of a PC5-RRC connection.

[0198] Optionally, the UE determines at least one of the fourth conditions. When at least one of the fourth conditions is met, the UE performs the establishment of the PC5 Relay RLC channel, or the UE applies the RLC configuration specified by the SL-U2U-RLC protocol. Optionally, the establishment of the PC5 Relay RLC channel includes: establishing the RLC entity associated with the PC5 Relay RLC channel and / or the corresponding logical channel. Optionally, the UE determines the fourth conditions only when the upper layer(s) requests to transmit a PC5-S message for a certain target on the SL-SRB, or when the upper layer(s) indicates the establishment of a PC5-RRC connection.

[0199] Among them, the third condition is the same as the third condition in Embodiment 6, and the fourth condition is the same as the fourth condition in Embodiment 6.

[0200] Embodiment 8

[0201] Optionally, if the UE (AS layer or RRC layer) is requested by the upper layer(s) to release the PC5-RRC connection for a certain target (UE or layer 2 ID), and / or if the UE detects a sidelink communication radio link failure for a certain target, and / or if it receives a sl-ResetConfig included in the RRCReconfigurationSidelink message sent by a certain target (UE or layer 2 ID), the UE processes the MAC layer.

[0202] Optionally, when at least one of the following conditions is met, the processing performed by the UE on the MAC layer is to reset the sidelink specific MAC for the target:

[0203] - Except that the (target's) PC5-RRC connection is an end-to-end PC5-RRC connection;

[0204] - The (target) PC5-RRC connection is a per-hop PC5-RRC connection;

[0205] - The (target) PC5-RRC connection is not an end-to-end PC5-RRC connection.

[0206] Figure 12 is a simplified structural block diagram of a user equipment UE according to the present invention. As Figure 12 shown, the user equipment UE1200 includes a processor 1201 and a memory 1202. The processor 1201 may include, for example, a microprocessor, a microcontroller, an embedded processor, etc. The memory 1202 may include, for example, volatile memory (such as random access memory RAM), a hard disk drive (HDD), non-volatile memory (such as flash memory), or other memories, etc. Program instructions are stored on the memory 1202. When executed by the processor 1201, these instructions can perform the above methods executed by the user equipment described in detail in the present invention.

[0207] A program running on a device according to the present invention can be a program that enables a computer to implement the functions of the embodiments of the present invention by controlling a central processing unit (CPU). The program or the information processed by the program can be temporarily stored in volatile memory (such as random access memory RAM), a hard disk drive (HDD), non-volatile memory (such as flash memory), or other memory systems.

[0208] Programs for implementing the functions of the embodiments of the present invention can be recorded on a computer-readable recording medium. The corresponding functions can be implemented by causing a computer system to read the programs recorded on the recording medium and execute these programs. The so-called "computer system" here can be a computer system embedded in the device and can include an operating system or hardware (such as peripheral devices). The "computer-readable recording medium" can be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a recording medium for storing programs dynamically for a short time, or any other recording medium readable by a computer.

[0209] The various features or functional modules of the devices used in the above embodiments may be implemented or executed by circuitry (e.g., a single or multiple integrated circuits). The circuitry designed to perform the functions described in this specification may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination of the above devices. The general-purpose processor may be a microprocessor, or any existing processor, controller, microcontroller, or state machine. The above circuitry may be digital circuitry or analog circuitry. In the case where new integrated circuit technologies emerge as a result of the progress of semiconductor technology to replace existing integrated circuits, one or more embodiments of the present invention may also be implemented using these new integrated circuit technologies.

[0210] In addition, the present invention is not limited to the above embodiments. Although various examples of the described embodiments have been described, the present invention is not limited thereto. Fixed or non-mobile electronic devices installed indoors or outdoors may be used as terminal devices or communication devices, such as AV devices, kitchen devices, cleaning devices, air conditioners, office equipment, vending machines, and other household appliances, etc.

[0211] As described above, the embodiments of the present invention have been described in detail with reference to the accompanying drawings. However, the specific structure is not limited to the above embodiments, and the present invention also includes any design modifications that do not deviate from the gist of the present invention. Additionally, various modifications can be made to the present invention within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. Furthermore, components having the same effects described in the above embodiments may be substituted for each other.

Claims

1. A method performed by a user equipment UE, comprising: The UE receives a message containing indication information for indicating a change in a sidelink communication connection or a sidelink communication bearer corresponding to a certain target; The UE triggers a process corresponding to the change according to the indication information; In the process, the UE determines the type of the sidelink communication connection or sidelink communication bearer and / or the association status with the RLC channel or RLC entity, and performs corresponding processing on the RLC layer and / or MAC layer according to the type of the sidelink communication connection or sidelink communication bearer and / or the association status with the RLC channel or RLC entity.

2. The method according to claim 1, wherein, The UE receives a PC5-RRC message containing SL-DRB release information for indicating the release of an SL-DRB; The UE triggers an SL-DRB release process according to the SL-DRB release information; In the SL-DRB release process, the UE determines a first condition, and when at least one of the first conditions is met, the UE releases the RLC entity associated with the SL-DRB and / or the corresponding logical channel; and the UE determines a second condition, and when at least one of the second conditions is met, the UE performs a PC5-relayed RLC channel release associated with the SL-DRB.

3. The method according to claim 1, wherein, When the UE is required by the upper layer to release the PC5-RRC connection for a certain target and / or detects a sidelink communication radio link failure of a certain target, the UE releases the PC5-RRC connection corresponding to the target; The UE triggers an SL-DRB release process associated with the PC5-RRC connection; In the SL-DRB release process, the UE determines a first condition, and when at least one of the first conditions is met, the UE releases the RLC entity associated with the SL-DRB of the target and / or the corresponding logical channel; and the UE determines a second condition, and when at least one of the second conditions is met, the UE performs a PC5-relayed RLC channel release associated with the SL-DRB of the target.

4. The method according to claim 1, wherein, The UE receives a PC5-RRC message containing SL-DRB modification information for indicating the modification of an SL-DRB; The UE triggers the SL-DRB modification process according to the SL-DRB modification information; In the SL-DRB modification process, the UE determines a first condition, and when at least one of the first conditions is met, the UE reconfigures the RLC entity associated with the SL-DRB and / or the corresponding logical channel; and the UE determines a second condition, and when at least one of the second conditions is met, the UE performs a PC5-relayed RLC channel modification associated with the SL-DRB.

5. The method according to any one of claims 2 to 4, wherein, The first condition includes at least one of the following: - The SL-DRB is a per-hop SL-DRB; - The SL-DRB is not an end-to-end SL-DRB; - No SL-DRB is associated with the RLC channel or RLC entity associated with the SL-DRB; - There is no other SL-DRB other than the said SL-DRB associated with the RLC channel or RLC entity associated with the said SL-DRB. The second condition includes at least one of the following: - The said SL-DRB is an end-to-end SL-DRB; - The said SL-DRB is not a per-hop SL-DRB; - There is no end-to-end SL-DRB associated with the PC5 relay RLC channel associated with the said SL-DRB; - There is no other end-to-end SL-DRB other than the said SL-DRB associated with the PC5 relay RLC channel associated with the said SL-DRB.

6. The method according to claim 1, wherein, The UE releases the PC5-RRC connection corresponding to the said target when required by the upper layer to release the PC5-RRC connection for a certain target, and / or when required by the upper layer to terminate the PC5-S transmission for a certain target, and / or when detecting a sidelink communication radio link failure of a certain target. The UE triggers the SL-SRB release process for PC5-RRC messages and / or triggers the SL-SRB release process for PC5-S messages. In the SL-SRB release process, the UE judges the third condition, and when at least one of the third conditions is satisfied, the UE releases the RLC entity and / or the corresponding logical channel associated with the said SL-SRB; and the UE judges the fourth condition, and when at least one of the fourth conditions is satisfied, the UE executes the release of the PC5 relay RLC channel associated with the said SL-SRB.

7. The method according to claim 1, wherein, The UE adds or establishes an SL-SRB when the upper layer requires the transmission of a PC5-S message for a certain target on the SL-SRB, or when the upper layer indicates the establishment of a PC5-RRC connection. In the SL-SRB addition or establishment process, the UE judges the third condition, and when at least one of the third conditions is satisfied, the UE establishes the RLC entity and / or the corresponding logical channel associated with the SL-SRB for PC5-RRC messages, and / or the UE establishes the RLC entity and / or the corresponding logical channel associated with the SL-SRB for PC5-S messages; and the UE judges the fourth condition, and when at least one of the fourth conditions is satisfied, the UE executes the establishment of the PC5 relay RLC channel, or applies the RLC configuration stipulated by the SL-U2U-RLC protocol.

8. The method according to claim 6 or 7, wherein, The third condition includes at least one of the following: - The said SL-SRB is a per-hop SL-SRB; - The said SL-SRB is not an end-to-end SL-SRB; - There is no SL-SRB associated with the RLC channel or RLC entity associated with the said SL-SRB; - There is no other SL-SRB other than the said SL-SRB associated with the RLC channel or RLC entity associated with the said SL-SRB; - The PC5-RRC connection is a per-hop PC5-RRC connection; - The PC5-RRC connection is not an end-to-end PC5-RRC connection; - The PC5+S message is a per-hop PC5-S message; - The PC5-S message is not an end-to-end PC5-S message, The fourth condition includes at least one of the following: - The SL-SRB is an end-to-end SL-SRB; - The SL-SRB is not a per-hop SL-SRB; - No end-to-end SL-SRB is associated with the PC5 relay RLC channel associated with the SL-SRB; - No other end-to-end SL-SRB other than the SL-SRB is associated with the PC5 relay RLC channel associated with the SL-SRB; - The PC5-RRC connection is an end-to-end PC5-RRC connection; - The PC5-RRC connection is not a per-hop PC5-RRC connection; - The PC5-S message is an end-to-end PC5-S message; - The PC5-S message is not a per-hop PC5-S message.

9. According to the method of claim 1, wherein, The UE processes the MAC layer when being required by the upper layer to release the PC5-RRC connection for a certain target, and / or detecting a sidelink communication radio link failure for a certain target, and / or receiving a sidelink communication RRC reconfiguration message sent by a certain target that includes a sidelink communication reset configuration. When at least one of the following conditions is met, the processing performed by the UE on the MAC layer is to reset the MAC specific to the sidelink communication for the target: - Except that the PC5-RRC connection for the target is an end-to-end PC5-RRC connection; - The PC5-RRC connection for the target is a per-hop PC5-RRC connection; - The PC5-RRC connection for the target is not an end-to-end PC5-RRC connection.

10. A user equipment, comprising: A processor; and a memory storing instructions, wherein the instructions, when run by the processor, execute the method according to any one of claims 1 to 9.

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