Method and user equipment

Abstract

According to a method and user equipment for triggering relay reselection performed by a remote UE. The relay reselection is used to reselect a relay UE that provides a sideline communication relay for the remote UE. The method includes: when the SL-RSRP measurement configuration between the remote UE and the current relay UE is obtained, SL-RSRP measurement is performed to obtain the SL-RSRP measurement result of the sideline communication between the remote UE and the current relay UE; if the SL-RSRP measurement result is obtained within a first given period, based on the obtained SL-RSRP measurement result, it is determined whether relay reselection should be triggered; if the SL-RSRP measurement result is not obtained within the first given period, then: based on the SD-RSRP measurement result of the discovery message transmitted by the current relay UE to the remote UE, it is determined whether relay reselection should be triggered; or it is determined that relay reselection should be triggered; and when it is determined that relay reselection should be triggered, relay reselection is triggered.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and more specifically, to a method for executing sideline communication relay reselection by a user equipment and a corresponding user equipment. Background Art

[0002] In June 2018, at the 3rd Generation Partnership Project (3GPP) RAN#80 plenary meeting, the Release 16 V2X feasibility study project based on 5G NR network technology (see non-patent literature: RP-181480, New SID Proposal: Study on NR V2X) was approved. The main functions of Release 16 NR V2X include supporting unicast, multicast and broadcast in scenarios with and without network coverage.

[0003] In December 2019, at the RAN#86 plenary meeting, a research project on NR sidelink relaying for version 17 was proposed (see non-patent document: RP-193253 New Study Item on NR Sidelink Relaying) and approved. The latest version of this research project can be found in non-patent document: RP-201474 reivsed SID NR sidelink relay. This research project mainly studies UE (user equipment) to network and UE to UE relay solutions for extending coverage based on sidelink communication. One of the goals of this research project is to support the selection and reselection of sidelink communication relays.

[0004] In the existing relay architecture, after the remote UE has selected a relay UE to provide it with relay services for sidelink communication, it determines whether it is necessary to trigger relay reselection by measuring the reference signal received power of the discovery message (or discovery channel). In the NR sidelink relaying research project of version 17, if a PC5 unicast link is established between the remote UE and the relay UE, it is also possible to determine whether it is necessary to trigger relay reselection by measuring the received power of the reference signal on the unicast link, thereby reducing the power consumption generated by broadcasting or monitoring discovery messages to obtain measurement results.

[0005] The present invention discusses the related issues of how a remote UE determines whether to trigger relay reselection based on measurement of a discovery message or measurement of a PC5 unicast link. Summary of the invention

[0006] The object of the present invention is to provide a method for triggering relay reselection executed by a remote UE.

[0007] According to one aspect of the present invention, a method for triggering relay reselection performed by a remote UE is provided, wherein the relay reselection is used to reselect a relay UE that provides sideline communication relay for the remote UE, and the method comprises: when the SL-RSRP measurement configuration between the remote UE and the current relay UE is obtained, performing SL-RSRP measurement to obtain the SL-RSRP measurement result of the sideline communication between the remote UE and the current relay UE; if the SL-RSRP measurement result is obtained within a first given period, judging whether relay reselection should be triggered based on the obtained SL-RSRP measurement result; if the SL-RSRP measurement result is not obtained within the first given period, judging whether relay reselection should be triggered based on the SD-RSRP measurement result of the discovery message transmitted by the current relay UE to the remote UE; or judging that relay reselection should be triggered; and triggering relay reselection when it is judged that relay reselection should be triggered.

[0008] Optionally, the first given period is a first timing period starting from the moment when the SL-RSRP measurement configuration information is acquired. When the following conditions are met, it is judged that the SL-RSRP measurement result is acquired within the first given period: the SL-RSRP measurement result is acquired before the first timing timeout corresponding to the first timing period.

[0009] Optionally, the method further includes: when the SL-RSRP measurement result is obtained, recording the SL-RSRP acquisition time when the SL-RSRP measurement result is obtained. The first given period is a discovery cycle for discovering candidate relay UEs, and for each discovery cycle, when the following conditions are met, it is determined that the SL-RSRP measurement result is obtained within the first given period: the currently recorded SL-RSRP acquisition time is within the discovery cycle.

[0010] Optionally, the first given period is a given number of discovery periods, and when the following conditions are met, it is judged that the SL-RSRP measurement result is obtained within the first given period: when judging whether the currently recorded SL-RSRP acquisition moment is within the discovery period for each discovery period, the judgment result is that the number of times the currently recorded SL-RSRP acquisition moment is within the discovery period exceeds the first given number,

[0011] Optionally, the first given period is a given number of discovery periods, and when the following conditions are met, it is judged that the SL-RSRP measurement result is not obtained within the first given period: when judging whether the currently recorded SL-RSRP acquisition moment is within the discovery period for each discovery period, the judgment result is that the number of times the currently recorded SL-RSRP acquisition moment is not within the discovery period exceeds the first given number.

[0012] Optionally, the method further includes: for each acquired SL-RSRP measurement result, determining whether a first time interval between a SL-RSRP acquisition moment of the SL-RSRP measurement result and a previous SL-RSRP acquisition moment of a previously acquired SL-RSRP measurement result exceeds one discovery cycle, wherein when any of the following conditions is met, it is determined that the SL-RSRP measurement result is acquired within the first given period: for each acquired SL-RSRP, a first time interval corresponding to the SL-RSRP does not exceed one discovery cycle; when determining whether a first time interval corresponding to the SL-RSRP exceeds one discovery cycle for each acquired SL-RSRP, the judgment result is that the number of times that the first time interval does not exceed one discovery cycle exceeds a second given number,

[0013] Optionally, when the following conditions are met, it is judged that the SL-RSRP measurement result is not obtained within the first given period: when judging whether the first time interval corresponding to the SL-RSRP exceeds a discovery cycle for each acquired SL-RSRP, the judgment result is that the number of times the first time interval exceeds a discovery cycle exceeds a second given number.

[0014] Optionally, the method also includes: when the SL-RSRP measurement configuration between the remote UE and the current relay UE is obtained, stopping the discovery message transmission for discovering the candidate relay UE; and if the SL-RSRP measurement result is not obtained at the end of the first given period, starting the discovery message transmission.

[0015] Optionally, determining whether to trigger relay reselection includes: if the SL-RSRP measurement result is obtained within a first given period, then when the SL-RSRP measurement result is lower than a first given threshold, determining that relay reselection should be triggered; and / or if the SL-RSRP measurement result is not obtained within the first given period, then when the obtained SD-RSRP is lower than a second given threshold, determining that relay reselection should be triggered.

[0016] Optionally, when judging whether relay reselection should be triggered based on the SD-RSRP measurement result of the discovery message transmitted by the current relay UE to the remote UE, the method also includes: if the SL-RSRP measurement result is obtained within a second given period, then: stopping the discovery message transmission, and / or restarting the first given period to again determine whether the SL-RSRP measurement result is obtained within the first given period, and deciding whether to trigger relay reselection based on the judgment result; and judging whether relay reselection should be triggered based on the obtained SL-RSRP measurement result, the second given period being the period starting from the moment the first given period ends.

[0017] Optionally, the method also includes: if the SL-RSRP measurement result is not obtained within the first given period, starting a second timing, wherein the SL-RSRP measurement result is judged to be obtained within the second given period when any of the following conditions is met: the SL-RSRP measurement result is obtained before the second timing times out; within the second timing period, the number of times the SL-RSRP measurement result is obtained reaches a predetermined number of times.

[0018] Optionally, triggering relay reselection includes performing the following actions: starting discovery message transmission for candidate relay UEs to search for the candidate relay UEs; obtaining the SD-RSRP of the discovery message transmitted by the candidate relay UEs; and selecting a candidate relay UE whose SD-RSRP exceeds a third given threshold as a new relay UE.

[0019] According to another aspect of the present invention, a user equipment is provided, comprising: a processor; and a memory storing instructions; wherein the instructions execute the above method when executed by the processor.

[0020] According to the method of the present invention, a method can be provided which can save power consumption and trigger relay reselection in time. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram for illustrating a remote UE and a relay UE involved in the present invention.

[0022] Figure 2 It is a flowchart of a method for triggering relay reselection according to embodiment 1 of the present invention.

[0023] Figure 3 It is a partial flow chart of the method for triggering relay reselection according to embodiment 2 of the present invention.

[0024] Figure 4 It is a flowchart of a method for triggering relay reselection according to embodiment 3 of the present invention.

[0025] Figure 5 The figure is a simplified structural block diagram of a user equipment UE involved in the present invention. DETAILED DESCRIPTION

[0026] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the present invention should not be 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.

[0027] The following describes some of the terms involved in the present invention. The specific meanings of the terms can be found in the latest 3GPP standard specifications, such as TS38.300, TS38.331, TS36.300, TS36.331, etc. Unless otherwise specified, the terms involved in the present invention have the following meanings.

[0028] UE:User Equipment

[0029] NR: New Radio, a new generation of wireless technology

[0030] RRC: Radio Resource Control

[0031] RRC_CONNECTED: RRC connected state

[0032] RRC_INACTIVE: RRC inactive state

[0033] RRC_IDLE: RRC idle state

[0034] RAN: Radio Access Network, wireless access layer

[0035] Sidelink: Sidelink communication

[0036] SCI: Sidelink Control Information, sidelink communication control information

[0037] RSRP: Reference Signal Receiving Power, reference signal receiving power

[0038] PSCCH: Physical Sidelink Control Channel, physical sidelink communication control channel

[0039] PSSCH: Physical Sidelink Shared Channel, physical sidelink communication shared channel

[0040] AS: Access Stratum, access layer

[0041] PDCCH: Physical downlink control channel, physical downlink control channel

[0042] BWP: Bandwidth Part, bandwidth fragment

[0043] DCI: Downlink Control Information, downlink control information

[0044] DL: Downlink, downlink

[0045] IE: Information Element, information element

[0046] CE: Control Element

[0047] MIB: Master Information Block, master information block

[0048] NR — New Radio

[0049] SIB: System Information Block, system information block

[0050] DCI: Downlink Control Information, downlink control information

[0051] DM-RS: Dedicated demodulation reference signal, dedicated demodulation reference signal

[0052] SD-RSRP: Sidelink Discovery Reference Signal Received Power, sidelink communication discovery reference signal received power

[0053] SL-RSRP: Sidelink RSRP, sidelink communication reference signal received power

[0054] In the present invention, network, base station and RAN can be used interchangeably, and the network can be a long-term evolution LETS network, a new radio access technology (New RAT, NR) network, an enhanced long-term evolution eLTE network, or other networks defined in subsequent evolution versions of 3GPP.

[0055] 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 may refer to other types of NR devices or LTE devices.

[0056] The PC5 interface is the interface for control plane and user plane sidelink communication between UE and UE. For Sidelink unicast, the PC5-RRC connection is an AS layer logical connection between a pair of source layer 2 ID and target layer 2 ID. The establishment of a PC5 unicast link will correspond to the establishment of a PC5-RRC connection.

[0057] Figure 1 is a schematic diagram for explaining UE-to-UE relay. Figure 1 As shown, the left and right sides are remote UEs (the left UE can also be called the source side remote UE, and the right UE can also be called the target side remote UE), and the middle is the relay UE. The remote UE and the relay UE are connected through the PC5 interface respectively. Since the two remote UEs are far apart or the communication environment is not good, the relay UE is required to relay and forward the signaling and data between the two.

[0058] There are two modes found in Sidelink relay, namely Mode A and Mode B:

[0059] -Mode A is equivalent to "Here I am!".

[0060] Two roles are defined: notifying UE and listening UE. Notifying UE periodically broadcasts discovery notifications, while listening UE reads and processes discovery notifications.

[0061] - Mode B is equivalent to "Who's there?" or "Are you there?".

[0062] It also defines two roles: discovering UE and being discovered UE. The discovering UE sends a discovery request, and the being discovered UE responds to the discovery request.

[0063] Discovery notifications, discovery requests, and discovery responses may be collectively referred to as discovery messages.

[0064] In the prior art, if the remote UE has selected a relay UE to provide it with a relay service for side communication, it is determined whether it is necessary to trigger the relay UE to reselect by measuring the received power of the reference signal. If the discovery relay mode A is adopted, the relay UE periodically broadcasts the discovery notification, and the remote UE monitors the received power of the reference signal of the discovery notification. If the discovery relay mode B is adopted, the remote UE sends a discovery request message, the relay UE replies with a discovery response message, and the remote UE monitors the received power of the reference signal of the discovery response message. If the reference signal received power (SD-RSRP) of the discovery message of the currently selected relay UE is lower than a given threshold value, or the upper layer determines that the relay needs to be changed, the AS layer of the remote UE triggers the relay reselection. The sending and listening period of the discovery message can be configured by the network or pre-configured. If a PC5 unicast link is established between the remote UE and the relay UE, it is also possible to determine whether it is necessary to trigger the relay UE to reselect by measuring the received power (SL-RSRP) of the reference signal on the unicast link. The SL-RSRP measurement on the PC5 unicast link is based on the measurement of the DM-RS on the PSSCH channel. The DM-RS is only accompanied by data transmission on the PC5 unicast link. Therefore, if the relay UE has no data to send, the remote UE cannot obtain the SL-RSRP. The SL-RSRP measurement can be configured by the peer UE or by the network. Discovery messages are also transmitted on the PSSCH channel, and the AS layer needs to distinguish between discovery messages and other data. In order to reduce the power consumption generated by broadcasting or monitoring discovery messages to obtain measurement results, it can be determined whether relay reselection is required based on SL-RSRP.

[0065] Since SL-RSRP depends on whether there is data to be sent on the unicast link, the data transmission of the relay UE may be non-periodic, and the remote UE cannot predict when the relay UE will send data. The relay UE may not send data for a long time, so the remote UE may not obtain SL-RSRP for a long time. In this case, the remote UE needs to have a way to determine whether to trigger relay reselection based on SD-RSRP instead of triggering relay reselection based on SL-RSRP measurement. The present invention provides a corresponding method, which can save power consumption and minimize reselection delays, thereby avoiding adverse effects on service experience.

[0066] In the following, several embodiments of the present invention are described in detail on how the remote UE determines to trigger relay reselection based on SD-RSRP measurement or based on SL-RSRP measurement of PC5 unicast link.

[0067] Example 1

[0068] like Figure 2 As shown, in embodiment 1 of the present invention, the steps performed for user equipment UE include: steps 101, 103, and 105.

[0069] In step 101, when the remote UE receives the SL-RSRP measurement configuration, the remote UE performs one or more of the following actions:

[0070] -Start T1 timer;

[0071] - Stop broadcasting or monitoring discovery messages, where discovery messages include but are not limited to discovery notifications, discovery requests, and discovery responses.

[0072] The remote UE may receive the SL-RSRP measurement configuration in one or more of the following scenarios:

[0073] -After the remote UE and relay UE establish a PC5 unicast link, they receive the SL configured by the peer UE.

[0074] RSRP measurement configuration;

[0075] -The Remote UE receives the SL-RSRP measurement configuration configured by the network, which can be sent to the remote UE via system message broadcast or RRC dedicated signaling;

[0076] -The Remote UE pre-configures the SL-RSRP measurement configuration according to the protocol definition.

[0077] The duration of the T1 timer can be:

[0078] - Optionally, a multiple (integer or fractional) of the length of the discovery period;

[0079] -optionally, a number of time slots;

[0080] -optionally, a number of subframes;

[0081] -optionally, a number of radio frames;

[0082] - optionally, a number of milliseconds;

[0083] -optionally, a number of seconds.

[0084] During T1 operation, the remote UE determines whether to trigger relay reselection based on SL-RSRP.

[0085] In step 103, when the remote UE obtains the SL-RSRP measurement result, the T1 timer is restarted. If the SL-RSRP measurement result is lower than a certain threshold, relay reselection is triggered.

[0086] The relay reselection action may include one or more of the following:

[0087] - Start broadcasting or listening to discovery messages (corresponding to "discovery message transmission");

[0088] -Search for candidate sideline communication relay UEs;

[0089] - Apply layer 3 filtering to SD-RSRP measurements;

[0090] -Select a candidate sideline communication relay UE whose SD-RSRP exceeds a certain threshold as the relay UE.

[0091] In step 105, when the T1 timer times out, the UE performs one or more of the following actions:

[0092] - Optionally, the remote UE starts broadcasting or listening to discovery messages.

[0093] -Optionally, the remote UE sends an AS layer message (possible forms include but are not limited to:

[0094] RRC message, MAC CE, physical layer indication, etc.) to the Relay UE to instruct the Relay UE to send a discovery message; for discovery mode A, the Relay UE sends a discovery notification message after receiving the indication message; for discovery mode B, the Relay UE sends a discovery response message after receiving the indication message.

[0095] -Optionally, the Remote UE sends an AS layer message (possible forms include but are not limited to:

[0096] RRC message, MAC CE, physical layer indication, etc.) to the Relay UE to instruct the Relay UE to send data or response; after receiving the indication message, the Relay UE sends AS layer data (optionally,

[0097] The data is normal data or empty data) or AS layer response message.

[0098] - Optionally, the remote UE searches for a candidate sideline communication relay UE;

[0099] - Optionally, the remote UE applies layer 3 filtering to the SD-RSRP measurement result;

[0100] - Optionally, the remote UE selects a candidate sideline communication relay UE whose SD-RSRP exceeds a certain threshold value as the relay UE;

[0101] - Optionally, if the SD-RSRP measurement result is lower than a certain threshold value, the remote UE triggers relay reselection, and the relay reselection includes selecting a candidate sideline communication relay UE whose SD-RSRP exceeds a certain threshold value as the relay UE.

[0102] The expiration of the T1 timer can directly trigger relay reselection; or after the T1 timer expires, broadcast or monitor discovery messages first, and then determine whether to trigger relay reselection based on SD-RSRP.

[0103] Example 2

[0104] like Figure 3 As shown, in Embodiment 2 of the present invention, the steps performed for the user equipment UE include: Steps 201 and 203.

[0105] In step 201, based on embodiment 1, when timer T1 times out, timer T2 is started. The duration of timer T2 can be:

[0106] - Optionally, a multiple (integer or fractional) of the length of the discovery period;

[0107] -optionally, a number of time slots;

[0108] -optionally, a number of subframes;

[0109] -optionally, a number of radio frames;

[0110] - optionally, a number of milliseconds;

[0111] -optionally, a number of seconds.

[0112] In step 203, while the T2 timer is running:

[0113] - Optionally, if the remote UE obtains the SL-RSRP measurement result, the T2 timer is stopped, and the remote UE performs one or more of the following actions: Optionally, the T1 timer is started; Optionally, the broadcast or monitoring of the discovery message is stopped.

[0114] - Optionally, when the T2 timer is running, if the number of SL-RSRP measurement results continuously obtained by the remote UE exceeds a threshold value, the T2 timer is stopped, and the remote UE performs one or more of the following actions: Optionally, start the T1 timer; Optionally, stop broadcasting or monitoring discovery messages.

[0115] The subsequent processing of T1 is the same as that in Example 1.

[0116] Example 3

[0117] like Figure 4 As shown, in embodiment 3 of the present invention, the steps performed for user equipment UE include: steps 301, 303, 305, and 307.

[0118] In step 301, when the remote UE obtains the SL-RSRP measurement result, the first SL-RSRP time information (SL-RSRP acquisition time) is recorded. The recorded first SL-RSRP time information may be:

[0119] -Optionally, the absolute time (such as UTC time, GPS time, etc.) when the SL-RSRP measurement result is obtained;

[0120] -Optionally, the relative time when the SL-RSRP measurement result is obtained includes one or more of the following: a radio frame number, a subframe number, a time slot number, etc.

[0121] In step 303,

[0122] -Optionally, in each discovery period, the remote UE checks the first SL-RSRP time information (ie, the currently recorded SL-RSRP acquisition time).

[0123] ■Optionally, if the first SL-RSRP time information indicates that the time of acquiring the SL-RSRP is within the discovery period, the broadcasting or monitoring of the discovery message is stopped, and the remote UE determines whether to trigger relay reselection based on the SL-RSRP.

[0124] ■Optionally, if the first SL-RSRP time information indicates that the time when the SL-RSRP is acquired is within the discovery period, the counter C1 is incremented by 1 (the initial value of C1 is 0). If the counter C1 exceeds a certain threshold value, the counter C1 is reset, and the broadcast or monitoring of the discovery message is stopped. The remote UE determines whether to trigger relay reselection based on the SL-RSRP.

[0125] ■Optionally, if the first SL-RSRP time information indicates that the time when the SL-RSRP is acquired is not within the discovery period, the counter C2 is incremented by 1 (the initial value of C2 is 0).

[0126] -Optionally, each time the SL-RSRP is acquired, the remote UE first checks the saved first SL-RSRP time information of the previous SL-RSRP acquisition.

[0127] ■If the difference between the first SL-RSRP time information and the current time does not exceed one discovery cycle, stop broadcasting or monitoring the discovery message, and the remote UE determines whether to trigger relay reselection based on SL-RSRP.

[0128] ■Optionally, if the difference between the first SL-RSRP time information and the current time does not exceed one discovery cycle, counter C1 is incremented by 1 (the initial value of C1 is 0). If counter C1 exceeds a certain threshold value, counter C1 is reset, broadcasting or monitoring discovery messages is stopped, and the remote UE determines whether to trigger relay reselection based on SL-RSRP.

[0129] ■If the difference between the first SL-RSRP time information and the current time exceeds one discovery cycle, the counter C2 is incremented by 1 (the initialization value of C2 is 0).

[0130] Among them, the discovery message includes but is not limited to discovery notification, discovery request, and discovery response.

[0131] In step 305, if the SL-RSRP measurement result is lower than a certain threshold, relay reselection is triggered.

[0132] The relay reselection action may include one or more of the following:

[0133] - Start broadcasting or listening for discovery messages;

[0134] -Search for candidate sideline communication relay UEs;

[0135] - Apply layer 3 filtering to SD-RSRP measurements;

[0136] -Select a candidate sideline communication relay UE whose SD-RSRP exceeds a certain threshold as the relay UE.

[0137] In step 307 , when the counter C2 exceeds a certain threshold value, the remote UE clears the counter C2 , and other actions performed by the UE are the same as those in step 105 .

[0138] When counter C2 exceeds a certain threshold value, relay reselection can be directly triggered; or after counter C2 exceeds a certain threshold value, broadcast or monitor discovery messages are started first, and then whether to trigger relay reselection is determined based on SD-RSRP.

[0139] Figure 51 is a simplified structural diagram of a user equipment UE according to the present invention. Figure 5 As shown, the user equipment UE 500 includes a processor 501 and a memory 502. The processor 501 may include, for example, a microprocessor, a microcontroller, an embedded processor, etc. The memory 502 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 memories, etc. The memory 502 stores program instructions. When the instructions are executed by the processor 501, the above method performed by the user equipment described in detail in the present invention may be executed.

[0140] The program running on the 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 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.

[0141] The program for realizing the functions of various embodiments of the present invention can be recorded on a computer-readable recording medium. The corresponding functions can be realized by making a computer system read the program recorded on the recording medium and executing these programs. The so-called "computer system" herein can be a computer system embedded in the device, and can include an operating system or hardware (such as a peripheral device). "Computer-readable recording medium" can be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a recording medium of a short-term dynamic storage program, or any other recording medium that is computer-readable.

[0142] 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). Circuits designed to perform the functions described in this specification may include general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), 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 case where 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.

[0143] In addition, the present invention is not limited to the above-mentioned 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.

[0144] As mentioned 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 changes that do not deviate from the main purpose of the present invention. In addition, the present invention can be modified in various ways within the scope of the claims, and the 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, the components with the same effect described in the above embodiments can be replaced with each other.

Claims

1. A method for triggering relay reselection performed by a remote UE, the relay reselection being used to reselect a relay UE that provides a sideline communication relay for the remote UE, the method comprising: When the SL-RSRP measurement configuration between the remote UE and the current relay UE is obtained, perform SL-RSRP measurement to obtain the SL-RSRP measurement result of the remote communication between the remote UE and the current relay UE; If the SL-RSRP measurement result is obtained within the first given period, determining whether relay reselection should be triggered based on the obtained SL-RSRP measurement result; If the SL-RSRP measurement result is not obtained within the first given period, then: judging whether relay reselection should be triggered based on the SD-RSRP measurement result of the discovery message transmitted by the current relay UE to the remote UE; as well as When it is determined that relay reselection should be triggered, relay reselection is triggered.

2. The method according to claim 1, wherein: The first given period is a first timing period from the moment when the SL-RSRP measurement configuration information is acquired. When the following conditions are met, it is determined that the SL-RSRP measurement result is acquired within the first given period: The SL-RSRP measurement result is obtained before a first timing corresponding to the first timing period times out.

3. The method according to claim 1, further comprising: When the SL-RSRP measurement result is obtained, the SL-RSRP acquisition time at which the SL-RSRP measurement result is obtained is recorded, wherein: The first given period is a discovery period for discovering a candidate relay UE. For each discovery period, when the following conditions are met, it is determined that the SL-RSRP measurement result is obtained within the first given period: The currently recorded SL-RSRP acquisition time is within the discovery period, or, The first given period is a given number of discovery periods, and when the following conditions are met, it is determined that the SL-RSRP measurement result is obtained within the first given period: When determining for each discovery cycle whether the currently recorded SL-RSRP acquisition time is within the discovery cycle, the determination result is that the number of times the currently recorded SL-RSRP acquisition time is within the discovery cycle exceeds a first given number, or, The first given period is a given number of discovery cycles, and when the following conditions are met, it is determined that the SL-RSRP measurement result is not obtained within the first given period: When determining for each discovery cycle whether the currently recorded SL-RSRP acquisition time is within the discovery cycle, the determination result is that the number of times that the currently recorded SL-RSRP acquisition time is not within the discovery cycle exceeds a first given number.

4. The method according to claim 1, further comprising: For each SL-RSRP measurement result obtained, determine whether a first time interval between a SL-RSRP acquisition time of the SL-RSRP measurement result and a previous SL-RSRP acquisition time of a previous SL-RSRP measurement result obtained exceeds one discovery cycle, wherein: When any of the following conditions is met, it is determined that the SL-RSRP measurement result is obtained within the first given period: For each acquired SL-RSRP, the first time interval corresponding to the SL-RSRP does not exceed one discovery cycle; When determining, for each acquired SL-RSRP, whether a first time interval corresponding to the SL-RSRP exceeds one discovery cycle, the determination result is that the number of times that the first time interval does not exceed one discovery cycle exceeds a second given number, or, When the following conditions are met, it is determined that the SL-RSRP measurement result is not obtained within the first given period: When determining, for each acquired SL-RSRP, whether a first time interval corresponding to the SL-RSRP exceeds one discovery cycle, the determination result is that the number of times that the first time interval exceeds one discovery cycle exceeds a second given number of times.

5. The method according to any one of claims 1 to 4, further comprising: When the SL-RSRP measurement configuration between the remote UE and the current relay UE is acquired, stopping the transmission of a discovery message for discovering a candidate relay UE; as well as If the SL-RSRP measurement result is not obtained at the end of the first given period, the discovery message transmission is started.

6. The method according to any one of claims 1 to 4, wherein: Determining whether to trigger relay reselection includes: If the SL-RSRP measurement result is obtained within a first given period, when the SL-RSRP measurement result is lower than a first given threshold, it is determined that relay reselection should be triggered; and / or If the SL-RSRP measurement result is not obtained within the first given period, when the obtained SD-RSRP is lower than a second given threshold, it is determined that relay reselection should be triggered.

7. The method according to any one of claims 1 to 4, wherein: When judging whether relay reselection should be triggered based on the SD-RSRP measurement result of the discovery message transmitted by the current relay UE to the remote UE, the method further includes: If the SL-RSRP measurement result is obtained within the second given period, then: Stopping the discovery message transmission, and / or restarting the first given period; and Based on the acquired SL-RSRP measurement result, it is determined whether relay reselection should be triggered, and the second given period is a period starting from the moment when the first given period ends.

8. The method according to claim 7, further comprising: If the SL-RSRP measurement result is not obtained within the first given period, a second timing is started, wherein: When any of the following conditions is met, it is determined that the SL-RSRP measurement result is obtained within the second given period: The SL-RSRP measurement result is obtained before the second timing times out; During the second timing period, the number of times the SL-RSRP measurement result is obtained reaches a predetermined number of times.

9. The method according to any one of claims 1 to 4, wherein: Triggering relay reselection includes: Perform the following actions: Starting to transmit a discovery message for a candidate relay UE to search for the candidate relay UE; Obtaining the SD-RSRP of the discovery message transmitted by the candidate relay UE; and A candidate relay UE whose SD-RSRP exceeds a third given threshold is selected as a new relay UE.

10. A user equipment, comprising: processor; as well as A memory storing instructions; The instructions, when executed by the processor, perform the method according to any one of claims 1 to 9.

Images