Method executed by user equipment, and user equipment

Abstract

Provided in the present invention are a method executed by a user equipment, and a user equipment. The method comprises: receiving an RRC message comprising synchronization reconfiguration information; and when the synchronization reconfiguration information comprises a sidelink path switching configuration and meets at least one of the following conditions, indicating to an upper layer target relay UE identification information indicated by the synchronization reconfiguration information, such that the upper layer triggers the establishment of a PC5 unicast link with a target relay UE corresponding to the target relay UE identification information: on a source side, a UE serving as an L2 U2N remote UE which is not configured with multiple paths; on a target side, the UE serving as an L2 U2N remote UE which is not configured with multiple paths; the target relay UE identification information being different from the identification of a source-side relay UE; the synchronization reconfiguration information comprising an indirect path release instruction; and the synchronization reconfiguration information comprising an indirect path release instruction, and the indirect path release instruction instructing the UE to release a source-side indirect path.

Description

Method performed by user equipment and user equipment Technical Field

[0001] The present invention relates to the field of wireless communication technology, and more particularly, to a method performed by a user equipment during communication based on a multi-path communication mode and a corresponding user equipment. Background Art

[0002] Within a cell covered by a base station, a user equipment (UE) can communicate directly with the base station. This type of communication connection is called a direct connection. The UE can also communicate with the base station through a relay UE. This type of connection is called an indirect connection or indirect connection. When communicating with the base station through a relay UE, the UE is called a remote UE.

[0003] To improve the UE's uplink and downlink transmission rates and throughput, the UE can operate in both direct and indirect connection modes. As shown in Figure 1, this mode of operation is also known as multi-path communication, as the UE and base station communicate simultaneously through different paths.

[0004] In Figure 1 , wireless communication is generally used between the remote UE and the base station, as well as between the relay UE and the base station, such as 5G NR or LTE. Communication between the remote UE and the relay UE can be based on sidelink communication or other communication methods (for example, Wi-Fi based on hotspot coverage or wired connection).

[0005] Based on information such as UE service changes, radio link conditions, and base station load, the base station can initiate path additions and modifications. For example, it can configure the UE to switch from a single path to multiple paths, remove a path from multiple paths to a single path, or modify one or two paths in a multipath. How the UE executes the path addition, deletion, or modification process is a challenge. Summary of the Invention

[0006] In order to solve at least part of the above problems, the present invention provides a method performed by a user equipment and the user equipment, which enables the UE to correctly perform path addition, deletion, and modification operations upon receiving configuration from a base station.

[0007] According to one aspect of the present invention, a method performed by a user equipment (UE) is provided, comprising: receiving an RRC message including synchronous reconfiguration information; indicating to an upper layer target relay UE identification information indicated by the synchronous reconfiguration information when the synchronous reconfiguration information includes a sidelink path switching configuration and at least one of the following conditions is satisfied, so that the upper layer triggers establishment of a PC5 unicast link with a target relay UE corresponding to the target relay UE identification information: the UE acts as an L2 U2N remote UE not configured with multipath on the source side; the UE acts as an L2 U2N remote UE not configured with multipath on the target side; the target relay UE identification information is different from the source-side relay UE identification; the synchronous reconfiguration information includes a release indirect path indication; the synchronous reconfiguration information includes the release indirect path indication, and the release indirect path indication instructs the UE to release the source-side indirect path.

[0008] According to another aspect of the present invention, a method performed by a user equipment (UE) is provided, comprising: after successfully performing a handover and switching to a target side, and sending an RRC reconfiguration complete message to a network, if the synchronous reconfiguration information that triggered the handover includes a sidelink path switching configuration, releasing the source-side MAC configuration except for the MAC configuration used for the source-side sidelink communication when at least one of the following conditions is met: the UE acts as an L2 U2N remote UE configured with multipath on the source side; the UE acts as an L2 U2N remote UE not configured with multipath on the target side; a target relay UE identifier included in the synchronous reconfiguration information is the same as a source-side relay UE identifier; the synchronous reconfiguration information does not include a release indirect path indication; the synchronous reconfiguration information includes a release indirect path indication, and the release indirect path indication instructs the UE not to release the source-side indirect path.

[0009] According to one aspect of the present invention, a method performed by a user equipment (UE) is provided, comprising: receiving an RRC message including synchronization reconfiguration information; indicating to an upper layer to trigger release of a PC5 unicast link between the UE and a source-side relay UE when the synchronization reconfiguration information includes a sidelink path switching configuration and at least one of the following conditions is met: the UE functions as an L2 U2N remote UE on the source side; the UE functions as an L2 U2N remote UE configured with multipath on the source side; the UE functions as an L2 U2N remote UE not configured with multipath on the target side; a target relay UE identifier included in the synchronization reconfiguration information is different from a source-side relay UE identifier; the RRC message includes a release indirect path indication; the RRC message includes the release indirect path indication, and the release indirect path indication instructs the UE to release the source-side indirect path.

[0010] Optionally, the method also includes: after instructing the upper layer to trigger the release of the PC5 unicast link between the source side relay UE, indicating the target relay UE identifier included in the synchronization reconfiguration information to the upper layer, so that the upper layer triggers the establishment of a PC5 unicast link between the target relay UE corresponding to the target relay UE identifier.

[0011] According to one aspect of the present invention, a method performed by a user equipment (UE) is provided, comprising: receiving an RRC message including synchronous reconfiguration information; indicating to an upper layer to trigger release of a PC5 unicast link between the UE and a source-side relay UE when the synchronous reconfiguration information does not include a sidelink path switching configuration and at least one of the following conditions is met: the UE acts as an L2 U2N remote UE not configured with multipath on the source side; the UE acts as an L2 U2N remote UE not configured with multipath on the target side; the synchronous reconfiguration information includes a release indirect path indication; the synchronous reconfiguration information includes a release indirect path indication, and the release indirect path indication instructs the UE to release the source-side indirect path.

[0012] Optionally, in the case where the synchronization reconfiguration information in the RRC message includes a sidelink indirect path release indication, the method further includes: if the sidelink indirect path release indication instructs the UE to release the sidelink indirect path, then when the UE is determined to be currently in a state of executing release instructed by the network, the UE releases the configuration for the sidelink indirect path.

[0013] Optionally, the indirect path release indication instructs the UE to release the sidelink indirect path, and the state of executing the release indicated by the network includes at least one of the following: being in the path switching process; the connection of the indirect path is a PC5 unicast link; the indirect path is a sidelink indirect path; the UE is an L2 U2N remote UE configured with multipath on the target side after executing the switching.

[0014] Optionally, the indirect path release indication instructs the UE to release the N3C indirect path, and the state of executing the release indicated by the network includes at least one of the following: being in the path switching process; the connection of the indirect path of the UE is an N3C connection; the UE is an L2 U2N remote UE configured with multipath on the target side.

[0015] According to one aspect of the present invention, a user equipment is provided, comprising: a processor; and a memory storing instructions, wherein the instructions, when executed by the processor, execute the method described above.

[0016] According to the present invention, the UE can correctly perform path addition / modification / deletion operations after receiving the path addition / modification / deletion configuration sent by the base station, and reduce unnecessary message reconfiguration, thereby reducing the impact on service performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG1 is a schematic diagram showing UE-to-Network relay.

[0018] FIG. 2 is a schematic diagram showing a multi-path communication method in which direct connection and indirect path are operated in parallel (multi-path).

[0019] FIG3 is a flowchart illustrating a method according to an embodiment of the present invention.

[0020] FIG4 is a flowchart illustrating a method according to another embodiment of the present invention.

[0021] FIG5 is a flowchart illustrating a method according to another embodiment of the present invention.

[0022] FIG6 is a simplified structural block diagram of a user equipment UE according to the present invention. DETAILED DESCRIPTION

[0023] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the present invention is not limited to the specific embodiments described below. In addition, for the sake of simplicity, detailed descriptions of known technologies that are not directly related to the present invention are omitted to prevent confusion in understanding the present invention.

[0024] The following describes some of the terms involved in this invention. The specific meanings of the terms can be found in the latest 3GPP standards.

[0025] UE: User Equipment

[0026] NR: New Radio, a new generation of wireless technology

[0027] PHY: physical layer, physical layer

[0028] MAC: Medium Access Control, multimedia access control

[0029] RLC: Radio Link Control

[0030] SDAP: Service Data Adaptation Protocol

[0031] PDCP: Packet Data Convergence Protocol, Packet Data Convergence Protocol

[0032] SRAP: Sidelink Relay Adaptation Protocol, Sidelink Relay Adaptation Protocol

[0033] RRC: Radio Resource Control

[0034] RRC_CONNECTED: RRC connected state

[0035] RRC_INACTIVE: RRC inactive state

[0036] RRC_IDLE: RRC idle state

[0037] RAN: Radio Access Network

[0038] NG-RAN: Next-generation radio access network

[0039] gNB: the next Generation Node B

[0040] Sidelink: Sidelink communication, sidelink

[0041] SL: Sidelink

[0042] SCI: Sidelink Control Information, sidelink communication control information

[0043] AS: Access Stratum, access layer

[0044] IE: Information Element

[0045] CE: Control Element

[0046] MIB: Master Information Block

[0047] SIB: System Information Block

[0048] DCI: Downlink Control Information, downlink control information

[0049] RB: radio bearer

[0050] DRB: Data Radio Bearer

[0051] SRB: Signaling Radio Bearer

[0052] Uu: air interface

[0053] ProSe:Proximity based Services:Proximity services

[0054] V2X: Vehicle-to-Everything

[0055] NAS: Non-Access-Stratum

[0056] PC5-S: PC5 signalling, PC5 signaling

[0057] SL-SRB: Sidelink Signalling Radio Bearer

[0058] SL-DRB: Sidelink Data Radio Bearer, sidelink communication data radio bearer

[0059] U2U: UE-to-UE, UE to UE

[0060] U2N: UE-to-Network

[0061] L2: Layer 2, layer 2 architecture

[0062] RSRP: Reference Signal Received Power

[0063] SL-RSRP: Sidelink RSRP, sidelink communication reference signal received power

[0064] SD-RSRP: sidelinkdiscoveryRSRP, sidelink communication discovery message reference signal received power

[0065] SpCell: Special Cell, including PCell and PSCell

[0066] PCell: Primary Cell

[0067] PSCell: Primary SCG Cell, SCG main cell

[0068] L2-ID: Layer-2 ID (identity), layer 2 identification

[0069] MP: Multi-path

[0070] N3C: Non-3GPP Connection

[0071] 3GPP: 3rd Generation Partnership Project

[0072] In the present invention, network (network or NW), base station (base station or gNB or eNB) and RAN are used interchangeably. The network may be a Long Term Evolution LTE network, a New Radio Access Technology (NewRAT, NR) network, an enhanced Long Term Evolution eLTE network, or other networks defined in subsequent evolution versions of 3GPP. The base station in the present invention may be any type of base station, including Node B, enhanced base station eNB, 5G communication system base station gNB; 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 may also be a cell under any of the above-mentioned types of base stations. Unless otherwise specified, the cell, beam, and transmission point (TRP) may be interchangeable, and the base station may also be a central unit (gNB-Central Unit, gNB-CU) or a distributed unit (gNB-Distributed Unit, gNB-DU) constituting the base station.

[0073] In the present invention, the user equipment UE may refer to the NR device supporting the NR Sidelink relay function described in the background technology, or to the NR device supporting the multipath communication function, or may refer to other types of NR devices or LTE devices.

[0074] In the present invention, sidelink, SL and PC5 can be used interchangeably.

[0075] In the present invention, unless otherwise specified, “Relay UE”, “U2N Relay UE” and “L2 U2N Relay UE” can be used interchangeably. Unless otherwise specified, “Remote UE”, “U2N Remote UE” and “L2 U2N Remote UE” can be used interchangeably.

[0076] In the present invention, "switch", "path switch", and "handover" can be used interchangeably. "Change" and "update" can be used interchangeably.

[0077] In the present invention, "working in a multipath mode" and "being configured with multipath" can be used interchangeably.

[0078] In the present invention, "configure", "set" and "present" can be used interchangeably.

[0079] In the present invention, “used,” “available,” “active,” “applied,” “performed,” and “enabled” may be used interchangeably.

[0080] In the present invention, "use", "make available", "apply", "implement", "enable", "activate", "perform", "use (d0)", etc. can be used interchangeably.

[0081] In the present invention, "feedback", "submit", "report", "send", "transmit or transport", "inform", "indicate" and "provide" can be used interchangeably.

[0082] In the present invention, "trigger" and "initiate" can be used interchangeably.

[0083] In the present invention, "associate", "correspond" and "map" can be used interchangeably.

[0084] In the present invention, "non-3GPP connection" and "N3C connection" can be used interchangeably.

[0085] In the present invention, the "source-side Relay UE Identity" can also be described as: the Relay UE Identity to which the UE is currently connected through an indirect path, or the Relay UE Identity to which the UE is currently connected.

[0086] In the present invention, "not release" and "retain" can be used interchangeably.

[0087] In the present invention, "path" and "connection" can be used interchangeably.

[0088] It should be noted that in this specification, two things connected by "and", "or", or "and / or" may represent different ways of expressing the same meaning in different application scenarios. There may be a relationship of inclusion and being included between the two, and they do not necessarily refer to completely different content.

[0089] Hereinafter, a description is given of related technologies of the present invention.

[0090] PC5 interface

[0091] The PC5 interface is used for control and user plane sidelink communication between UEs. For sidelink unicast, a PC5-RRC connection is a logical connection at the AS layer between a source Layer 2 ID and a target Layer 2 ID. The upper layer establishes a PC5 unicast link for sidelink unicast communication. Each established PC5 unicast link corresponds to a corresponding PC5-RRC connection.

[0092] Uu interface

[0093] The Uu interface is the wireless communication interface between the UE and the base station. The UE can communicate with the gNB using NR over the Uu interface.

[0094] L2 Architecture

[0095] The L2 architecture is relative to the L3 architecture. In the L2 architecture, the access layer controls or participates in the selection and reselection of relays, as well as the communication between a UE and the network or another UE through relays. In the L3 architecture, the access layer is largely unaware of the existence of relays, or in other words, relays are transparent to the access layer.

[0096] U2N (UE-to-Network) relay

[0097] Figure 1 shows a UE-to-network relay. The left side shows the remote UE (Remote UE), the middle side shows the relay UE (Relay UE), and the right side shows the network. The remote UE and relay UE are connected via the PC5 interface, while the relay UE and the network are connected via the Uu interface. Because the remote UE is far from the network or the communication environment is poor, the relay UE is required to relay signaling and data between the two.

[0098] In the U2U relay architecture, a U2N Remote UE refers to a UE that communicates with the network through a U2N Relay UE. An L2 U2N Remote UE refers to a U2N Remote UE in the L2 architecture. A U2N Relay UE refers to a UE that provides functionality to enable a U2U Remote UE to connect to the network. An L2 U2N Relay UE refers to a U2N Relay UE in the L2 architecture.

[0099] Multi-path communication

[0100] As shown in Figure 2, when a UE communicates with the network via a direct path or an indirect path, communication between the UE and the network can be referred to as single-path communication, or single-path communication. When there is only an indirect path between the UE and the network, the PCell of the relay UE can serve as the PCell of the remote UE it serves. When there is only a direct path between the UE and the network, since there is no relay UE, such a UE cannot be referred to as a remote UE. The PCell of this UE serves as the serving cell for the UE's RRC connection.

[0101] To improve the UE's uplink and downlink transmission rates and throughput, the UE can simultaneously transmit data to the network via two paths, such as a direct path and an indirect path. In this operating mode, since the UE and the network communicate via different paths, it can also be called a multi-path (MP) communication mode. The directly connected path can be called a direct path, and the indirectly connected path can be called an indirect path. A UE that communicates with the network via multiple paths can be called an MP Remote UE.

[0102] An MP Remote UE is a remote UE configured with multipath. When the indirect path is a PC5 unicast link, the MP Remote UE is acting as an L2 U2N Remote UE, or an SL MP Remote UE. When the indirect path is a non-3GPP connection, the MP Remote UE is acting as an N3C Remote UE, or an N3C Remote UE.

[0103] An MP Relay UE provides an indirect path connection for an MP remote UE. When the indirect path connection is a PC5 unicast link, the MP Relay UE is acting as an L2 U2N Relay UE, or an SL MP Relay UE. When the indirect path connection is a non-3GPP connection, the MP Relay UE is acting as an N3C Relay UE, or an N3C MP Relay UE.

[0104] The MP Remote UE communicates with the network both through the MP Relay UE and directly with the network.

[0105] In the case of multi-path, the serving cells corresponding to the indirect path and the direct path may be the same or different, and the serving cell corresponding to the direct path is the primary cell (PCell).

[0106] Remote UE is relative to Relay UE. It exists only in single-path or multi-path scenarios with Relay UE. In single-path scenarios without Relay UE, for example, when there is only a direct path between the UE and the network, the UE cannot function as a Remote UE.

[0107] In order to achieve communication from a single path to multiple paths (i.e., path addition), as well as path modification during multi-path communication (modifying the direct path: for example, changing the cell connected to the direct path; modifying the indirect path: for example, changing the current serving Relay UE of the indirect path to another Relay UE), the UE can report the information of the candidate MP relay UE to the base station, and the base station configures the UE through RRC messages to achieve path addition / modification / deletion.

[0108] This invention discusses a method for communicating via a multipath communication method. This invention enables a UE to correctly perform path addition, modification, or deletion operations after receiving a path addition, modification, or deletion configuration from a base station, while reducing unnecessary message reconfiguration and thus minimizing the impact on service performance.

[0109] Below, several embodiments of the present invention for the above-mentioned problems are described in detail with reference to Figures 3 to 5. In Figures 3 to 5, in order to highlight the key points of each embodiment and avoid confusing the contents of each embodiment, the process after certain judgment results is shown as "end". However, this does not mean that no other operations are performed when the corresponding judgment result occurs. In fact, the user equipment can also perform other logically consistent operations as needed. In the following description of this application, the source side refers to the state before the handover is performed, and the target side refers to the state after the handover is performed.

[0110] Example 1

[0111] Optionally, this embodiment is directed to deleting a direct path from a multipath while retaining the connection and / or configuration of the original indirect path.

[0112] FIG3 is a flow chart showing the method of Example 1.

[0113] Optionally, in step 302, the UE receives an RRC message (eg, RRCReconfiguration) sent by the network. Optionally, the RRC message includes synchronization reconfiguration information (reconfigurationWithSync).

[0114] In step 304, it is determined whether the synchronization reconfiguration information includes a sidelink path switching configuration.

[0115] The synchronous reconfiguration information may include a sidelink path switching configuration (sl-PathSwitchConfig), and / or a target Relay UE identity (target Relay UE Identity), and / or a release indirect path indication. The release indirect path indication is used to indicate whether the UE releases the indirect path, and / or releases the connection of the indirect path, and / or whether to release the PC5 unicast link with the L2 U2N Relay UE connected to the indirect path, and / or release the PC5 unicast link with the source-side L2 U2N Relay UE. For example, the release indirect path indication is set to TRUE to indicate release, and is set to FALSE to indicate non-release (i.e., retention); or the release indirect path indication is set to release to indicate release.

[0116] Optionally, if the synchronous reconfiguration information of the RRC message includes a sidelink path switching configuration (sl-PathSwitchConfig), then in step 306, the UE determines at least one of the following conditions:

[0117] -The UE is acting as an L2 U2N Remote UE that is not configured with an MP on the source side;

[0118] -The UE is acting as an L2 U2N Remote UE that is not configured with an MP on the target side;

[0119] -The target Relay UE Identity is different from the source-side Relay UE Identity;

[0120] - the RRC message includes a release indirect path indication;

[0121] -The release indirect path indication instructs the UE to release the connection of the indirect path, and / or release the indirect path, and / or release the PC5 unicast link between the UE and the L2 U2N Relay UE connected to the indirect path, and / or release the PC5 unicast link between the UE and the source-side L2 U2N Relay UE.

[0122] If the UE meets at least one of the above conditions, in step 308, the UE indicates the target L2 U2N Relay UE to the upper layer (above the RRC layer). The target L2 U2N Relay UE is indicated by the target Relay UE Identity carried in the received RRC message, so that the upper layer triggers the establishment of a PC5 unicast link with the relay UE. Otherwise, the UE does not perform related operations.

[0123] Optionally, in step 310, the UE sends an RRCReconfigurationComplete message to the network via the L2 U2N Relay UE. Optionally, in step 312, when the UE successfully sends the RRCReconfigurationComplete message, it determines whether the synchronization reconfiguration information triggering the corresponding handover includes the sidelink path switch configuration. If the previously received synchronization reconfiguration information includes sl-PathSwitchConfig, then in step 314, the UE determines whether at least one of the following conditions is met:

[0124] -The UE is acting as a L2 U2N Remote UE configured with MP on the source side;

[0125] -The UE is acting as an L2 U2N Remote UE that is not configured with an MP on the target side;

[0126] -The target Relay UE Identity is the same as the source side Relay UE Identity;

[0127] - the RRC message does not include a release indirect path indication;

[0128] The indirect path release indication indicates that the UE does not release (i.e., retain) the connection of the indirect path, and / or does not release the indirect path, and / or does not release (i.e., retain) the PC5 unicast link between the UE and the L2 U2N Relay UE of the indirect path, and / or does not release (i.e., retain) the PC5 unicast link between the UE and the source-side L2 U2N Relay UE.

[0129] If the UE satisfies at least one of the above conditions, in step 316, the UE retains at least one of the following MAC configurations on the source side. Alternatively, if the UE satisfies at least one of the above conditions, the UE releases the source side MAC configuration, and the released source side MAC configuration does not include at least one of the following, that is, the MAC configuration on the source side is released except for at least one of the following:

[0130] -MAC configuration (sidelink or for sidelink communication) received by the UE from the (indirect path) L2 U2N Relay UE;

[0131] -MAC configuration (sidelink or for sidelink communication) received by the UE from the source-side L2 U2N Relay UE;

[0132] -The sidelink (or sidelink communication) MAC configuration received by the UE from the indirect path on the source side.

[0133] -UE MAC configuration for sidelink communication.

[0134] Example 2

[0135] Optionally, this embodiment is directed to deleting a direct path from a multipath, while releasing and then reestablishing an original indirect path.

[0136] FIG4 is a flow chart showing the method of the second embodiment.

[0137] In step 402, an RRC message including synchronization reconfiguration information is received.

[0138] In step 404, it is determined whether the synchronization reconfiguration information includes a sidelink path switching configuration.

[0139] Optionally, if the synchronous reconfiguration information in the RRC message includes a sidelink path switching configuration (sl-PathSwitchConfig), then in step 406, the UE determines whether at least one of the following conditions is met:

[0140] -The UE is acting as a L2 U2N Remote UE on the source side;

[0141] -The UE is acting as an L2 U2N Remote UE configured as an MP on the source side;

[0142] -The UE is acting as an L2 U2N Remote UE that is not configured with an MP on the target side;

[0143] -The target Relay UE Identity is different from the source-side Relay UE Identity;

[0144] - the RRC message includes a release indirect path indication;

[0145] -The release indirect path indication instructs the UE to release the connection of the indirect path, and / or release the indirect path, and / or release the PC5 unicast link between the UE and the L2 U2N Relay UE connected to the indirect path, and / or release the PC5 unicast link between the UE and the source-side L2 U2N Relay UE.

[0146] When the UE satisfies at least one of the above conditions, in step 408, the UE indicates to the upper layer (above the RRC layer) to trigger the release of the PC5 unicast link (with the source-side L2 U2N Relay UE).

[0147] Optionally, after the UE indicates to the upper layer (above the RRC layer) to trigger the release of the PC5 unicast link (with the source-side L2 U2N Relay UE), the UE further indicates to the upper layer (above the RRC layer) the target L2 U2N Relay UE, where the target L2 U2N Relay UE is indicated by the target Relay UE Identity carried in the received RRC message, so that the upper layer triggers the establishment of a PC5 unicast link with the target L2 U2N Relay UE.

[0148] Optionally, the other steps of this embodiment may be the same as those of Embodiment 1.

[0149] Example 3

[0150] Optionally, this embodiment aims to modify a direct path in a multipath, or to add a direct path to an indirect path to form a multipath, while retaining the connection and / or configuration of the original indirect path.

[0151] FIG5 is a flow chart showing the method of Embodiment 3.

[0152] Optionally, in step 502, the UE receives an RRC message (e.g., RRCReconfiguration) sent by the network. Optionally, the RRC message includes synchronization reconfiguration information (reconfigurationWithSync) and / or a release indirect path indication. The meaning of the release indirect path indication is the same as that of the release indirect path indication in Example 1.

[0153] In step 504, the UE determines whether the synchronization reconfiguration information includes a sidelink path switching configuration.

[0154] Optionally, if the synchronous reconfiguration information does not include the sidelink path switching configuration (sl-PathSwitchConfig), then in step 506, the UE determines at least one of the following conditions:

[0155] -The UE is acting as an L2 U2N Remote UE that is not configured with an MP on the source side;

[0156] -The UE is acting as an L2 U2N Remote UE that is not configured with an MP on the target side;

[0157] - The UE is acting as an L2 U2N Remote UE that is not configured with an MP before performing (or receiving) synchronization reconfiguration;

[0158] - The UE is acting as an L2 U2N Remote UE that is not configured with an MP after performing (or receiving) synchronization reconfiguration;

[0159] - the RRC message includes a release indirect path indication;

[0160] -The release indirect path indication instructs the UE to release the connection of the indirect path, and / or release the indirect path, and / or release the PC5 unicast link between the UE and the L2 U2N Relay UE connected to the indirect path, and / or release the PC5 unicast link between the UE and the source-side L2 U2N Relay UE.

[0161] If the UE meets at least one of the above conditions, in step 508, the UE indicates to the upper layer (above the RRC layer) to trigger the release of the PC5 unicast link (with the source side L2 U2N Relay UE); otherwise, the UE retains the PC5 unicast link (with the source side L2 U2N Relay UE).

[0162] Example 4

[0163] Optionally, according to embodiment 1, and / or embodiment 2, and / or 3, the release indirect path indication in the RRC message (e.g., RRCReconfiguration) received by the UE from the network may be two indication information, and / or indicate two types of information: one is a sidelink indirect path release indication, and the other is an N3C (i.e., non-3GPP) indirect path release indication.

[0164] Optionally, if the sidelink indirect path release indication indicates that the UE releases the sidelink indirect path (connection), the UE may further determine at least one of the following conditions:

[0165] - In the path switching process;

[0166] -The indirect path connection is a PC5 unicast link;

[0167] -indirect path is SL indirect path;

[0168] - The UE is acting as a L2 U2N Remote UE configured with MP on the target side.

[0169] When at least one of the above conditions is met, the UE considers that the (source side) SL indirect path is released and releases the corresponding configuration, and / or instructs the upper layer (above the RRC layer) to trigger the release of the PC5 unicast link between the UE and the source side L2 U2N Relay UE.

[0170] Optionally, if the N3C indirect path release indication indicates that the UE releases the N3C indirect path (connection), the UE may further determine at least one of the following conditions:

[0171] - In the path switching process;

[0172] -The indirect path connection is an N3C connection;

[0173] -Indirect path is N3C path;

[0174] - The UE is acting as a L2 U2N Remote UE configured with MP on the target side.

[0175] When at least one of the above conditions is met, the UE considers that the (source side) N3C indirect path is released and releases the corresponding configuration, and / or instructs the upper layer (above the RRC layer) to trigger the release of the N3C connection between the UE and the source side N3C Relay UE.

[0176] Example 5

[0177] Optionally, the UE receives an RRC message (eg, RRCReconfiguration) sent by the network. Optionally, the RRC message includes SpCell configuration, and / or the RRC message includes synchronization reconfiguration information (reconfiguration WithSync).

[0178] Optionally, the UE determines at least one of the following conditions:

[0179] -In the process of synchronous reconfiguration;

[0180] - In the path switching process;

[0181] -The UE is acting as an L2 U2N Remote UE that is not configured with an MP on the target side;

[0182] - The UE is acting as an L2 U2N Remote UE that is not configured with an MP after performing (or receiving) a path switch.

[0183] When the UE meets at least one of the above conditions, if rlf-TimersAndConstants is not configured, the values ​​of timer T301, timer T310, counter N310, and counter N311 are not applied; otherwise, if rlf-TimersAndConstants is not configured, for timer T301, timer T310, counter N310, and counter N311, the values ​​in SIB1 are applied.

[0184] Among them, timer T301 is a timer for RRC connection reestablishment and is started after the UE sends an RRC RestabilshmentRequest message. Timer T310 is a timer used to detect SpCell link failure (i.e., physical layer problem) and is started when N310 consecutive out-of-sync indications are received from the bottom layer (i.e., physical layer). Counter N310 and counter N311 are timers used to detect link failure. When an out-of-sync indication is received from the bottom layer (i.e., physical layer), N310 increases; when a synchronization indication is received from the bottom layer (i.e., physical layer), N311 increases.

[0185] Example 6

[0186] Optionally, in step 1, the UE receives an RRC message (e.g., RRCReconfiguration) sent by the network. Optionally, when the RRC message includes an indication for reporting N3C Relay UE information, or when the RRC message includes an indication for reporting N3C Relay UE information and the indication for reporting N3C Relay UE information is TRUE, the UE considers that it is configured to report information of (available) (candidate) relay UEs with non-3GPP connections (or N3C connections) to the network.

[0187] Optionally, in step 2, when the UE is configured to report information of (available) (candidate) relay UEs with non-3GPP connections to the network, the UE determines at least one of the following conditions:

[0188] - The UE has a non-3GPP connection available;

[0189] -The UE has one or more available non-3GPP connections;

[0190] - The UE has at least one available non-3GPP connection.

[0191] When the UE meets at least one of the above conditions, or since the UE is configured to report information of (candidate) relay UEs with non-3GPP connections (or N3C connections) to the network, no UE assistance information message (UEAssistanceInformation) containing N3C Relay UE information (list) has been sent and the UE meets at least one of the above conditions, or the non-3GPP connection of the previously reported Relay UE is not available and the UE meets at least one of the above conditions, the UE initiates the transmission of UEAssistanceInformation.

[0192] Optionally, in step 3, when the UE initiates UEAssistanceInformation transmission in order to report information of (available) (candidate) relay UEs with non-3GPP connections, the UE determines at least one of the following conditions:

[0193] - The UE has a non-3GPP connection available;

[0194] -The UE has one or more available non-3GPP connections;

[0195] - The UE has at least one available non-3GPP connection.

[0196] When the UE meets at least one of the above conditions, or since the UE is configured to report the information of (candidate) relay UEs with non-3GPP connections (or N3C connections) to the network, no UE assistance information message (UEAssistanceInformation) containing N3C Relay UE information (list) has been sent and the UE meets at least one of the above conditions, or the non-3GPP connection of the previously reported Relay UE is not available and the UE meets at least one of the above conditions, the UE includes the N3C Relay UE information (list) in the UEAssistanceInformation message to report the information of the Relay UE with the non-3GPP connection.

[0197] The (available) (candidate) relay UE with a non-3GPP connection may also be expressed as: a (available) (candidate) relay UE with a non-3GPP connection to the UE.

[0198] Figure 6 is a simplified block diagram of the user equipment (UE) according to the present invention. As shown in Figure 6, the user equipment (UE) 600 includes a processor 601 and a memory 602. The processor 601 may include, for example, a microprocessor, a microcontroller, an embedded processor, etc. The memory 602 may include, for example, a volatile memory (such as a random access memory (RAM), a hard disk drive (HDD), a non-volatile memory (such as a flash memory), or other memory. The memory 602 stores program instructions. When executed by the processor 601, these instructions may execute the above-described method performed by the user equipment as described in detail in the present invention.

[0199] The program running on the device according to the present invention can be a program that controls the central processing unit (CPU) to enable the computer to implement the functions of the embodiments of the present invention. The program or the information processed by the program can be temporarily stored in a volatile memory (such as a random access memory RAM), a hard disk drive (HDD), a non-volatile memory (such as a flash memory), or other memory systems.

[0200] The program for realizing each embodiment of the present invention function can be recorded on a computer-readable recording medium. Can realize corresponding function by making a computer system read the program recorded on the recording medium and executing these programs. So-called "computer system" herein can be the computer system embedded in the device, can include operating system or hardware (such as peripheral device). "Computer-readable recording medium" can be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a short-term dynamic storage program recording medium or any other recording medium that is computer-readable.

[0201] The various features or functional modules of the devices used in the above embodiments can be implemented or executed by circuits (e.g., single-chip or multi-chip integrated circuits). The circuits 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 circuits may be digital circuits or analog circuits. In the event that new integrated circuit technologies have emerged to replace existing integrated circuits due to advances in semiconductor technology, one or more embodiments of the present invention may also be implemented using these new integrated circuit technologies.

[0202] Furthermore, the present invention is not limited to the above-described embodiments. Although various examples of the embodiments have been described, the present invention is not limited thereto. Fixed or non-mobile electronic devices installed indoors or outdoors can be used as terminal devices or communication devices, such as AV equipment, kitchen equipment, cleaning equipment, air conditioners, office equipment, vending machines, and other household appliances.

[0203] As described above, 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-described embodiments, and the present invention also includes any design changes that do not deviate from the main purpose of the present invention. In addition, 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. In addition, components with the same effect described in the above embodiments can be replaced with each other.

Claims

1. A method performed by a user equipment UE, comprising: receiving an RRC message including synchronization reconfiguration information; When the synchronization reconfiguration information includes a sidelink path switching configuration and at least one of the following conditions is met, indicating to an upper layer the target relay UE identification information indicated by the synchronization reconfiguration information, so that the upper layer triggers establishment of a PC5 unicast link with the target relay UE corresponding to the target relay UE identification information: The UE acts as a L2 U2N remote UE not configured with multipath at the source side; The UE acts as a L2 U2N remote UE not configured with multipath on the target side; The target relay UE identification information is different from the source side relay UE identification; The synchronous reconfiguration information includes a release indirect path indication; The synchronization reconfiguration information includes a release indirect path indication, and the release indirect path indication instructs the UE to release a source-side indirect path.

2. A method performed by a user equipment UE, comprising: After the handover is successfully performed and the handover is switched to the target side, and an RRC reconfiguration complete message is sent to the network, if the synchronization reconfiguration information triggering the handover includes a sidelink path switching configuration, the source side MAC configuration other than the MAC configuration used for the source side sidelink communication is released when at least one of the following conditions is met: The UE acts as a L2 U2N remote UE configured with multipath at the source side; The UE acts as a L2 U2N remote UE not configured with multipath on the target side; The target relay UE identifier included in the synchronization reconfiguration information is the same as the source side relay UE identifier; The synchronous reconfiguration information does not include a release indirect path indication; The synchronization reconfiguration information includes a release indirect path indication, and the release indirect path indication indicates that the UE does not release the source-side indirect path.

3. A method performed by a user equipment UE, comprising: receiving an RRC message including synchronization reconfiguration information; When the synchronization reconfiguration information includes a sidelink path switching configuration and at least one of the following conditions is met, an upper layer is indicated to trigger the release of the PC5 unicast link between the source-side relay UE and the source-side relay UE: The UE acts as a L2 U2N remote UE at the source side; The UE acts as a L2 U2N remote UE configured with multipath at the source side; The UE acts as a L2 U2N remote UE not configured with multipath on the target side; The target relay UE identifier included in the synchronization reconfiguration information is different from the source side relay UE identifier; The RRC message includes a release indirect path indication; The RRC message includes a release indirect path indication, and the release indirect path indication instructs the UE to release the source side indirect path.

4. The method according to claim 3, further comprising: After indicating to the upper layer triggering the release of the PC5 unicast link with the source-side relay UE, the target relay UE identifier included in the synchronization reconfiguration information is indicated to the upper layer so that the upper layer triggers the establishment of a PC5 unicast link with the target relay UE corresponding to the target relay UE identifier.

5. A method performed by a user equipment UE, comprising: receiving an RRC message including synchronization reconfiguration information; When the synchronization reconfiguration information does not include the sidelink path switching configuration and at least one of the following conditions is met, the triggering of releasing the PC5 unicast link between the source-side relay UE and the upper layer is indicated: The UE acts as a L2 U2N remote UE not configured with multipath at the source side; The UE acts as a L2 U2N remote UE not configured with multipath on the target side; The synchronous reconfiguration information includes a release indirect path indication; The synchronization reconfiguration information includes a release indirect path indication, and the release indirect path indication instructs the UE to release the source-side indirect path.

6. The method according to any one of claims 1 to 5, wherein: In the case where the synchronization reconfiguration information in the RRC message includes a sidelink indirect path release indication, the method further includes: If the sidelink indirect path release indication instructs the UE to release the sidelink indirect path, the UE releases the configuration for the sidelink indirect path when it is determined that the UE is currently in a state of performing release instructed by the network.

7. The method according to claim 6, wherein: The indirect path release indication indicates that the UE releases the sidelink indirect path, and the state of performing the release indicated by the network includes at least one of the following: In the process of path switching; The connection of the indirect path is a PC5 unicast link; The indirect path is a sidelink indirect path; The UE acts as a L2 U2N remote UE configured with multipath at the target side after the handover.

8. The method according to claim 6, wherein: The indirect path release indication indicates that the UE releases the N3C indirect path, and the state of executing the release indicated by the network includes at least one of the following: In the path switching process; The connection of the indirect path of the UE is an N3C connection; The UE acts as a L2 U2N remote UE configured with multipath on the target side.

9. A user equipment, comprising: processor; as well as Memory, which stores instructions, Wherein, when the instructions are executed by the processor, the method according to any one of claims 1 to 8 is performed.

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