Data recovery method, device and system

Abstract

The invention discloses a data recovery method, device and system, relates to the field of communication, and is used for reducing packet loss probability and improving communication performance. The method comprises the following steps: sending a first data packet to a second terminal through a first relay device; obtaining radio bearer configuration information, the radio bearer configuration information comprising first indication information, and the first indication information being used for indicating execution of data recovery; receiving second indication information, wherein the second indication information is used for indicating the transmission condition of the first data packet; and according to the first indication information and the second indication information, retransmitting the data packets which are not successfully transmitted in the first data packets. Thus, in a relay scene, the first terminal can accurately determine the data packet which is not actually received by the second terminal according to the first indication information and the second indication information included in the radio bearer configuration information, and retransmit the part of the data packet, so that the probability of packet loss of the data packet can be reduced, and the transmission reliability can be improved.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a data recovery method, device and system. Background Art

[0002] At present, terminals (such as UE) can communicate through at least two communication interfaces, namely PC5 interface (direct communication interface between terminal devices) and Uu interface (cellular communication interface between terminal devices and base stations). When the terminal is within cellular coverage, it can use the Uu interface under the control of the cellular network to communicate with the base station through uplink (UL) or downlink (DL). Figure 1 Regardless of whether there is network coverage, the terminal can use the PC5 interface to communicate with other terminals through the sidelink (SL). Figure 2 The protocol stack used for communication between terminals is shown.

[0003] In order to improve system performance, such as enhancing coverage and increasing capacity, in some cases, relay equipment can be introduced to assist the source terminal (source UE) in forwarding data to the target terminal (target UE). Figure 3 It shows the protocol stack used for communication between the source terminal (UE1), the relay device, and the destination terminal (UE2) after the relay device is introduced.

[0004] In scenarios where there are relay devices, the communication path between the source terminal and the destination terminal includes multiple hops, and the communication situation is relatively complicated. In some scenarios, data from some of the multiple hops may be lost, resulting in data transmission failure and affecting the communication performance of the system. Summary of the invention

[0005] The present application provides a data recovery method, device and system for improving the reliability of data transmission.

[0006] In order to achieve the above objectives, this application adopts the following technical solutions:

[0007] In a first aspect, the technical solution of the present application provides a data recovery method, which can be applied to a first terminal or a component supporting the function of the first terminal (such as a chip system), and the method includes: sending a first data packet to a second terminal through a first relay device; obtaining wireless bearer configuration information, the wireless bearer configuration information includes first indication information, and the first indication information is used to indicate the execution of data recovery; receiving second indication information, and the second indication information is used to indicate the transmission status of the first data packet; according to the first indication information and the second indication information, retransmitting the data packets in the first data packet that were not successfully transmitted.

[0008] In the relay scenario, compared with the related technology, the RLC status report cannot accurately reflect whether the receiving end has actually received the data packet, resulting in retransmission failure. In the method of the embodiment of the present application, the first terminal can accurately determine the data packets that the second terminal has not actually received based on the first indication information and the second indication information included in the wireless bearer configuration information, and retransmit these data packets, which can reduce the probability of data packet loss, ensure business continuity as much as possible, and improve transmission reliability.

[0009] In a possible design, the first indication information is used to indicate the execution of data recovery, including: the radio bearer configuration information also includes a data radio bearer DRB identifier; the first indication information is used to instruct the PDCP entity corresponding to the DRB identifier of the first terminal to execute data recovery;

[0010] Or, the first indication information is used to indicate the execution of data recovery, including: the wireless bearer configuration information also includes first configuration information; the first indication information is used to instruct the PDCP entity corresponding to the first DRB identifier of the first terminal to perform data recovery; the first DRB identifier is the DRB identifier corresponding to the first configuration information.

[0011] In one possible design, it also includes:

[0012] A transmission completion indication is received from the first relay device, where the transmission completion indication is used to indicate that the first relay device has completed sending the first data packet to the second terminal.

[0013] For example, before the first terminal stops forwarding data packets through the first relay device, it sends data packets #100-#104, then the first relay device on the source link can forward the successfully received data packets (such as data packets #100-#102, #104) among the five data packets to the second terminal. In this way, the risk of packet loss can be reduced and the amount of data that the first terminal needs to retransmit can be reduced.

[0014] In one possible design, obtaining radio bearer configuration information includes:

[0015] Receiving, through the first relay device, the radio bearer configuration information from the second terminal;

[0016] or, receiving the radio bearer configuration information from the network device;

[0017] Alternatively, the radio bearer configuration information is pre-configured.

[0018] In one possible design, receiving the radio bearer configuration information from the second terminal includes:

[0019] receiving a link update message from the second terminal, wherein the link update message includes the radio bearer configuration information; the link update message is a link update request message;

[0020] or, receiving a connection establishment request from the second terminal, the connection establishment request including the radio bearer configuration information;

[0021] Or, receiving a radio resource control RRC message from the second terminal, where the RRC message includes the radio bearer configuration information.

[0022] In one possible design, receiving second indication information includes:

[0023] A packet data convergence layer protocol PDCP status report is received from the second terminal, where the PDCP status report includes the second indication information.

[0024] In one possible design, receiving second indication information includes:

[0025] receiving a first identifier from the first relay device, where the first identifier is the second indication information;

[0026] The second indication information is used to indicate the transmission status of the first data packet, including: the first identifier is used to indicate the identifier of the third data packet in the first data packet, and the third data packet is the data packet with the largest identifier among the consecutive data packets successfully received by the second terminal; or, the first identifier is used to indicate: the identifier of the data packet in the first data packet that the second terminal fails to receive; or, the first identifier is used to indicate: the identifier of the data packet in the first data packet that the second terminal successfully receives.

[0027] In this way, the first terminal can learn, based on the first identifier, the data packet that the second terminal has not actually received successfully, and retransmit the data packet accordingly.

[0028] In a possible design, before receiving the first identifier from the first relay device, the method further includes:

[0029] The length information of the identifier of the data packet is sent to the first relay device.

[0030] In this way, after the first terminal indicates the PDCP SN length to the relay device, the relay device can determine the PDCP SN number of the data packet according to the length of the PDCP SN, and indicate to the first terminal the PDCP SN of the data packet that the second terminal has not successfully received, and / or indicate the PDCP SN of the data packet that the second terminal has successfully received. For example, if the length of the PDCP SN number is 12 bits, when forwarding a data packet, the relay device can determine that the first 12 bits of the data packet are the PDCP SN number corresponding to the data packet.

[0031] In one possible design, it also includes:

[0032] If a first condition is met, a first communication configuration between the first terminal and the second terminal is maintained; the first communication configuration includes a PDCP configuration and / or a service data adaptation protocol SDAP configuration;

[0033] The first condition includes at least one of the following conditions: a radio link failure RLF occurs between the first terminal and the first relay device; the signal quality between the first terminal and the first relay device is lower than a first threshold; a notification message is received from the first relay device, and the notification message indicates that an RLF occurs between the second terminal and the first relay device, or indicates that the signal quality between the second terminal and the first relay device is lower than a second threshold; a first timer corresponding to the second terminal times out.

[0034] Compared with the related art in which the corresponding communication configuration is released once RLF occurs between the terminals, resulting in data packet loss, in the present application, it is determined that the first condition is met, which means that the signal quality between the first terminal and the second terminal is poor or RLF occurs. In this case, the first terminal can maintain the first communication configuration with the first terminal, so that PDCP data recovery can be performed subsequently (such as after establishing a new link) to reduce the probability of packet loss.

[0035] In one possible design, it also includes:

[0036] The first radio link control RLC entity of the first terminal receives an ACK message from the first relay device, where the ACK message is used to indicate that the first relay device successfully receives the second data packet in the first data packet;

[0037] After a first delay, the first RLC entity of the first terminal sends an indication of successful transmission of the second data packet to the PDCP entity of the first terminal;

[0038] The first duration is the duration of a second timer, and the second timer corresponds to the second data packet.

[0039] For example, compared to the related art, after the RLC entity receives the ACK message indicating the successful transmission of packet #100-102, it notifies the PDCP entity that the data transmission is successful, and the PDCP discards packet #100-102 accordingly. In the technical solution of the present application, after the RLC entity of the first terminal receives the ACK message indicating the successful transmission of packet #100-102, it delays for a period of time to indicate to the PDCP entity that the transmission of packet #100-102 is successful, so that when receiving the PDCP status report, the PDCP entity does not know the reception status of packet #100-102, and therefore does not delete the packet #101-102 that the second terminal actually failed to receive. That is, the first terminal can maintain the E2E configuration. In this way, the first terminal can perform PDCP data recovery later, thereby reducing packet loss. For example, the PDCP entity of the first terminal accurately learns that the second terminal has not successfully received packets #101-#103 based on the indication of the PDCP status report, and retransmits packets #101-#103 that have not been deleted, which can enable lossless transmission of data packets and thereby improve the reliability of data packet transmission.

[0040] In one possible design, configuration information of the second timer is received from the second terminal, or configuration information of the second timer is received from the first relay device; or a link update message is received, where the link update message includes the configuration information of the second timer;

[0041] The configuration information of the second timer includes the first duration.

[0042] In one possible design, receiving configuration information of the second timer from the first relay device includes:

[0043] Meeting a second condition, receiving configuration information of the second timer from the first relay device;

[0044] The second condition includes at least one of the following conditions: the signal quality between the first relay device and the first terminal is lower than a third threshold; the signal quality between the first relay device and the second terminal is lower than a fourth threshold; the load of the first relay device is higher than a fifth threshold.

[0045] In this way, when the signal quality between the first terminal and the second terminal is not good, the first relay device configures a timer for the first terminal so that the first terminal can delay indicating to the PDCP layer that the data transmission is successful after receiving the RLC status report, so as to avoid the PDCP entity from releasing data incorrectly, resulting in packet loss. Or, when the load of the first relay device is higher than the threshold and some of the data packets may not be forwarded in time, this method is used to reduce the probability of data packet loss.

[0046] In one possible design, receiving configuration information of the second timer from the second terminal includes:

[0047] satisfying a third condition, receiving configuration information of the second timer from the second terminal;

[0048] The third condition includes at least one of the following conditions: the signal quality between the first relay device and the first terminal is lower than a sixth threshold; the signal quality between the first relay device and the second terminal is lower than a seventh threshold; the third timer corresponding to the second terminal times out.

[0049] Meeting the third condition means that the signal quality between the first terminal and the second terminal is not good. In this case, the second terminal configures a timer for the first terminal so that the first terminal can delay indicating successful data transmission to the PDCP layer after receiving the RLC status report, so as to avoid the PDCP entity from erroneously releasing data and causing packet loss.

[0050] In one possible design, it also includes:

[0051] Receiving an ACK message from the first relay device;

[0052] The ACK message is discarded.

[0053] In this way, the first terminal can determine the data packets that need to be retransmitted based on the PDCP status report or the first identifier that can reflect the transmission status of multiple hops instead of the RLC status report (ACK / NACK) that reflects the transmission status of a single hop.

[0054] In one possible design, it also includes:

[0055] An identifier of a second relay device is sent to the first relay device, where the identifier of the second relay device is used to instruct the first relay device to establish a communication connection with the second relay device.

[0056] In this way, the first relay device can know that the two terminals have selected the second relay device, so that the data packets that the second terminal has not successfully received can be forwarded through the second relay device in the future. For example, the second relay terminal can retransmit the data packets that were successfully transmitted on the first hop of the source link but failed to be transmitted on the second hop to the second terminal, thereby ensuring the continuity of the service.

[0057] In the second aspect, a data recovery method is applied to a second terminal or a component supporting the function of the second terminal (such as a chip system), and the method includes: receiving a first data packet from a first terminal through a first relay device; obtaining wireless bearer configuration information, the wireless bearer configuration information including first indication information, and the first indication information is used to indicate the execution of data recovery; sending a packet data convergence layer protocol PDCP status report according to the first indication information; the PDCP status report is used to indicate the transmission status of the first data packet.

[0058] In a possible design, the first indication information is used to instruct to perform data recovery, including:

[0059] The radio bearer configuration information also includes a data radio bearer DRB identifier; the first indication information is used to instruct the PDCP entity corresponding to the DRB identifier of the second terminal to perform data recovery.

[0060] After the second terminal receives the data from the first terminal, it determines that data recovery needs to be performed based on the first indication information, and then sends a PDCP status report to the first terminal, so that the first terminal can determine the data that the second terminal actually did not receive successfully based on the PDCP status report, and retransmit the data accordingly.

[0061] In one possible design, obtaining radio bearer configuration information includes:

[0062] Receiving, through the first relay device, the radio bearer configuration information from the first terminal;

[0063] or, receiving the radio bearer configuration information from a network device;

[0064] Alternatively, the radio bearer configuration information is pre-configured.

[0065] In one possible design, receiving the radio bearer configuration information from the first terminal includes:

[0066] receiving a link update message from the first terminal, wherein the link update message includes the radio bearer configuration information; the link update message is a link update accept message;

[0067] or, receiving a connection establishment request from the first terminal, the connection establishment request including the radio bearer configuration information;

[0068] Or, receiving a radio resource control RRC message from the first terminal, where the RRC message includes the radio bearer configuration information.

[0069] In one possible design, it also includes:

[0070] If the fourth condition is met, a PDCP status report is sent to the second terminal;

[0071] The fourth condition includes at least one of the following conditions: the link establishment with the second relay device is completed; the second communication configuration between the first terminal and the second relay device is obtained; a link update request message is sent; a link update acceptance message is received; a transmission completion indication is received from the first relay device;

[0072] The second relay device is a relay device selected by the first terminal or the second terminal; the second communication configuration includes at least one of the following configurations: a radio link control RLC channel, and a mapping relationship between the RLC channel and the DRB.

[0073] In some of the above methods, before the link is switched between the first terminal and the second terminal, the second terminal can send a PDCP status report on the source link to inform the first terminal in advance of the data packet that was not successfully received, so that the first terminal can retransmit the data packet as soon as possible after establishing a new link.

[0074] In some embodiments, the link between the first terminal and the second relay device is established, and a new link is switched to and a second communication configuration between the first terminal and the second relay device is obtained, so that the second terminal can send a PDCP status report on the new link with better link quality, and can ensure as much as possible that the PDCP status report is successfully received by the first terminal.

[0075] In one possible design, it also includes:

[0076] If a first condition is met, a first communication configuration between the first terminal and the second terminal is maintained; the first communication configuration includes a PDCP configuration and / or a Service Data Adaptation Protocol SDAP configuration;

[0077] The fifth condition includes at least one of the following conditions: a radio link failure RLF occurs between the second terminal and the first relay device; the signal quality between the second terminal and the first relay device is lower than an eighth threshold; a notification message is received from the first relay device, and the notification message indicates that an RLF occurs between the first terminal and the first relay device, or indicates that the signal quality between the first terminal and the first relay device is lower than a ninth threshold; the first timer corresponding to the first terminal times out.

[0078] According to a third aspect, a data recovery method is provided, which is applied to a first relay device or a component (such as a chip system) supporting the function of the first relay device, and the method includes: receiving a first data packet from a first terminal; sending the first data packet to the second terminal; sending a first identifier to the first terminal, wherein the first identifier is used to indicate an identifier of a third data packet in the first data packet, wherein the third data packet is an identifier of a continuous data packet successfully received by the second terminal and has the largest identifier; or, the first identifier is used to indicate: an identifier of a data packet in the first data packet that the second terminal fails to receive; or, the first identifier is used to indicate: an identifier of a data packet in the first data packet that the second terminal successfully receives.

[0079] In a possible design, before sending the first identifier to the first terminal, the method further includes:

[0080] Receive length information of the identifier of the data packet from the first terminal.

[0081] In one possible design, it also includes:

[0082] After sending the first data packet, a transmission completion indication is sent to the first terminal, where the transmission completion indication is used to indicate that the first relay device has completed sending the first data packet to the second terminal.

[0083] In a fourth aspect, a data recovery method is provided for a second relay device, or a component (such as a chip system) supporting the function of the second relay device, the method comprising:

[0084] Sending the split QoS information and the corresponding identifier of the second terminal to the first terminal;

[0085] The split QoS information and the corresponding identifier of the first terminal are sent to the second terminal.

[0086] In this way, the first terminal and the second terminal can obtain information of the split QoS flow (QoS information) and transmit according to the QoS information.

[0087] In a fifth aspect, the technical solution of the present application provides a device, comprising: one or more processors, a memory, and one or more computer programs; wherein the processor is coupled to the memory, and the one or more computer programs are stored in the memory, and when the device is running, the processor executes the one or more computer programs stored in the memory so that the device executes the method in any design of any of the above aspects.

[0088] In a sixth aspect, the present application provides a device, including a functional module for executing a method in any possible design of any of the above aspects of the present application, the module can be implemented by software or hardware, or by a combination of software and hardware, such as a processing unit and a communication unit.

[0089] In a seventh aspect, the technical solution of the present application provides a computer-readable storage medium, including computer instructions. When the computer instructions are executed on a device, the device executes any possible design method in any of the above aspects.

[0090] In an eighth aspect, the technical solution of the present application provides a computer program product, which, when executed on a device, enables the device to execute any possible design method in any of the above aspects.

[0091] In a ninth aspect, the technical solution of the present application provides a data recovery system, which includes a first terminal, a second terminal and a first relay device in any possible design of any of the above aspects. Optionally, the system may also include a second relay device in any possible design of any of the above aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0092] Figure 1 A schematic diagram of a side link scenario provided in an embodiment of the present application;

[0093] Figure 2 A schematic diagram of the architecture of a protocol stack for a sidelink direct connection scenario provided in an embodiment of the present application;

[0094] Figure 3 A schematic diagram of the architecture of a protocol stack for a relay scenario provided in an embodiment of the present application;

[0095] Figure 4 A flowchart of a data transmission method in a relay scenario provided for related technologies;

[0096] Figure 5 A schematic diagram of the architecture of the system provided in the embodiment of the present application;

[0097] Figure 6 A schematic diagram of the architecture of the device provided in the embodiment of the present application;

[0098] Figure 7-Figure 13 A schematic diagram of a flow chart of a signaling transmission method provided in an embodiment of the present application;

[0099] Fig.14 A schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0100] Fig.15 A schematic diagram of the structure of a chip system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0101] First, the technical terms involved in the embodiments of the present application are introduced:

[0102] 1. Relay

[0103] In the terminal-to-terminal relay (UE-to-UE relay, referred to as U2U relay) scenario, there is an initiating terminal (also referred to as a source terminal), one or more target terminals (also referred to as destination terminals), and one or more relay devices. The source terminal may refer to the initiating terminal where the connection is established, and the target terminal is the opposite end of the source terminal. The relay device has stronger capabilities, such as having more receiving antennas and transmitting antennas. For example, if there is a need for unicast communication between the source terminal and the destination terminal, the signal between the source terminal and the destination terminal is poor, or the source terminal is outside the communication range of the destination terminal, the data or signaling between the source terminal and the destination terminal can be forwarded through the relay device.

[0104] like Figure 3 An example of the protocol architecture of the user plane of U2U relay is shown, and an adaptation layer is added between the radio link control (RLC) layer and the packet data convergence protocol (PDCP) layer to perform routing forwarding. For example, the adaptation layer can be used for multiplexing and demultiplexing of bearers, supporting different bearers to be multiplexed into one bearer, or splitting one bearer into different bearers. For example, in the case where a source terminal communicates with multiple destination terminals through a relay device, in order to distinguish information belonging to different destination terminals, the relay device can assign a local ID to each destination terminal, and carry the local ID in the data packet routing process to indicate the destination terminal to which the data belongs.

[0105] The data packets mentioned in the embodiments of the present application may carry signaling and / or data. For example, the source terminal may transmit data to the destination terminal via the data packet. For another example, the source terminal may transmit signaling to the destination terminal via the data packet.

[0106] Data can have different encapsulation formats at different protocol layers in the protocol stack. For example, the packet obtained by processing data at the RLC layer can be called an RLC packet.

[0107] 2. RLC acknowledgment mode (acknaw|edged mode, AM)

[0108] RLC transmission may include the following modes: unacknowiedged mode (UM), acknowledged mode (AM), and transport mode (TM).

[0109] AM can use the automatic repeat request (ARQ) mechanism to ensure the reliability of data transmission. Figure 2 , the RLC entity of the transmitting end (such as UE1) receives a data packet (PDCP protocol data unit (PDU)) from the PDCP entity, processes the data packet, and obtains an RLC packet. Figure 4 (a), UE1 sends RLC packets #100-#103 to the receiving end (such as UE2), and UE1 saves RLC packets #100-#103 in the buffer of the RLC layer. The RLC entity of UE1 receives the RLC status report from the RLC entity of UE2, and the RLC status report indicates that UE2 has not received RLC packet #103, then the RLC entity of UE1 retransmits the RLC packet #103. The RLC entity of UE1 receives the RLC status report from the RLC entity of UE2, and the RLC status report indicates that UE2 has received RLC packets #100-#102, then the RLC entity of UE1 does not need to retransmit the RLC packets #100-#102, and the RLC entity of UE1 sends an indication to the PDCP entity, indicating that RLC packets #100-#102 have been successfully transmitted. After confirming that the RLC packets #100-#102 have been successfully transmitted, the RLC entity of UE1 deletes the successfully transmitted RLC packets #100-#102.

[0110] In the U2U relay scenario, Figure 4 (a), taking UE1 sending data to UE2 as an example, UE1 sends RLC packets #100-#103 to UE2, and receives an RLC status report fed back by relay device 1, indicating that RLC packets #100-#102 are transmitted successfully, and RLC packet #103 fails to be transmitted. Relay device 1 forwards RLC packets #100-#102 to UE2, of which only RLC packet #100 is successfully transmitted to UE2. If UE1 or UE2 reselects another relay device (such as relay device 2) at this time, and establishes a new link between UE1 and UE2 through relay device 2 for communication, the information corresponding to RLC packet #103 will be lost. In addition, during the process of establishing a new link, if the unicast connection between UE1 and UE2 is released, the PDCP entity of UE1 will be released first and then reestablished, resulting in the loss of information corresponding to RLC packets #101-#103.

[0111] Visible, not like Figure 4 In the terminal direct communication scenario shown in (a), UE1 receives an RLC status report indicating that the data packet is successfully transmitted at the RLC layer, then the data packet must have been successfully transmitted to UE2. Figure 4 In the U2U relay scenario shown in (b), the data packet sent by the PDCP entity of UE1 needs to be transmitted through two or more hops before reaching the PDCP entity of UE2. The RLC status report received by UE1 indicates that the data packet is successfully transmitted at the RLC layer. The RLC status report may indicate that the data packet is successfully transmitted to the relay device, but it does not mean that the data packet has been successfully transmitted to UE2. In the U2U relay scenario, UE1 cannot accurately determine the information that needs to be retransmitted based on the RLC status report.

[0112] It can be seen that in the scenario of terminal direct communication, retransmitting the failed information according to the RLC status report can improve the reliability of information transmission to a certain extent, but this method cannot be directly applied to the relay scenario. In the relay scenario, the sender cannot accurately determine the information to be retransmitted based on the RLC status report, resulting in packet loss and information transmission failure in some cases.

[0113] In order to solve the above technical problems, an embodiment of the present application provides a data recovery method, which can be applicable to a communication system with a relay node. The communication system can be, but is not limited to, a long term evolution (LTE) system, a new radio (NR) system, or a next generation wireless communication system. Figure 5 An example of the architecture of a communication system to which the embodiments of the present application are applicable is shown. The system may include a source terminal, a relay device, and a destination terminal.

[0114] Terminal: Also known as user equipment (UE), mobile station (MS), mobile terminal (MT), etc., it refers to a device that provides voice and / or data connectivity to users. The terminal can be a mobile phone, computer, vehicle-mounted equipment, etc., without limitation. In the embodiment of the present application, the terminal can refer to a device capable of sidelink communication.

[0115] Optionally, the terminal may be in an RRC connected state, an RRC idle state (IDLE), an RRC inactive state (INACTIVE), or an out of coverage (OoC) state.

[0116] The source terminal and the destination terminal support end-to-end communication in the relay scenario through the relay service.

[0117] A relay device is a device that supports providing relay services and can be used to assist the source terminal and the destination terminal to forward data packets between the two to expand the communication range. The relay device can be a terminal, or the relay device can also be other forms of devices (such as network devices), without limitation.

[0118] Exemplarily, SL unicast communication is performed between the source terminal and the relay device, and between the destination terminal and the relay device.

[0119] Optionally, the system may also include network equipment. For example, it includes access network equipment: a radio access network (RAN) node or device that connects a terminal to a wireless network. The access network equipment is connected to a core network, such as EPC or 5GC. The access network equipment may be, but is not limited to, various base stations, such as LTE eNB, NR gNB or ng-eNB. The access network equipment may also be non-3GPP-based equipment, such as a router.

[0120] Optionally, one or more devices (such as terminals and relay devices) in the embodiments of the present application may be connected via Figure 6 This is achieved by the communication device in. Figure 6 The hardware structure diagram of the communication device provided in the embodiment of the present application is shown in FIG.

[0121] The processor 401 may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the program of the present application.

[0122] Optionally, the communication device may include a communication line 402, which may include a path for transmitting information between corresponding components of the device.

[0123] The communication interface 404 uses any transceiver or other device for communicating with other devices or communication networks, such as Ethernet, RAN, wireless local area networks (WLAN), etc.

[0124] The memory 403 may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory may exist independently and be connected to the processor via a communication line 402. The memory may also be integrated with the processor.

[0125] The memory 403 is used to store computer-executable instructions for executing the solution of the present application, and the execution is controlled by the processor 401. The processor 401 is used to execute the computer-executable instructions stored in the memory 403, thereby implementing the method provided in the following embodiments of the present application.

[0126] Optionally, the computer-executable instructions in the embodiments of the present application may also be referred to as application code, which is not specifically limited in the embodiments of the present application.

[0127] In a specific implementation, as an embodiment, the processor 401 may include one or more CPUs, such as Figure 6 CPU0 and CPU1 in.

[0128] In a specific implementation, as an embodiment, the communication device 400 may include multiple processors, such as Figure 6 401 and processor 408 in the embodiment of the present invention. Each of these processors may be a single-CPU processor or a multi-CPU processor. The processor herein may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0129] The communication device 400 mentioned above may be a general device or a special device. The embodiment of the present application does not limit the type of the communication device 400.

[0130] It should be noted that the message names between network elements or the names of parameters in the messages in the following embodiments of the present application are merely examples, and other names may be used in specific implementations, and the embodiments of the present application do not impose any specific limitations on this.

[0131] The embodiment of the present application takes a two-hop relay communication scenario as an example, which can be expanded to a multi-hop scenario in the future and is also applicable to the present technical solution.

[0132] In the embodiments of the present application, the reference to "used for..." does not necessarily mean exclusively used for. For example, information is used to indicate A. One design is that the information is not exclusively used to indicate A, but may also indicate B. One design is that the information is exclusively used to indicate A.

[0133] The method provided in the embodiments of the present application is described in detail below.

[0134] This article takes the example of a first terminal sending data to a second terminal for explanation, and the data recovery method of the second terminal sending data to the first terminal is also applicable to the technical solution of the embodiment of the present application.

[0135] like Figure 7 As shown, the method provided in the embodiment of the present application includes the following steps:

[0136] S101. A first terminal sends a first data packet to a second terminal through a first relay device.

[0137] For example, Figure 7 , the first terminal sends data packets #100-#103 to the second terminal through the first relay device.

[0138] S102: The first terminal obtains radio bearer configuration information, where the radio bearer configuration information includes first indication information, and the first indication information is used to instruct execution of data recovery.

[0139] Optionally, the wireless bearer configuration information also includes a DRB identifier; the first indication information is used to instruct the PDCP entity corresponding to the DRB identifier of the first terminal to perform data recovery. Subsequently, the first terminal may execute the data recovery method of the embodiment of the present application according to the first indication information. For example, if a new link is established between the first terminal and the second terminal, data recovery can be performed after the new link is established. In other examples, if the first terminal is not configured with the first indication information, the first terminal does not execute the data recovery method of the embodiment of the present application, and may use the solution of the related technology to retransmit according to the RLC status report.

[0140] As a possible implementation manner, S102 may be implemented as: receiving, through the first relay device, end-to-end (E2E) radio bearer configuration information from the second terminal.

[0141] E2E stands for end-to-end, and can refer to the concept between terminals at both ends in a U2U relay scenario. For example, an E2E unicast connection represents a unicast connection between UEs at both ends, and an E2E configuration represents a communication configuration between UEs at both ends.

[0142] Optionally, receiving the radio bearer configuration information from the second terminal can be implemented as: receiving a link update message from the second terminal, the link update message including the radio bearer configuration information; the link update message is a link update request message (Link modification request) or a link update accept message (Link modification accept).

[0143] Alternatively, receiving the radio bearer configuration information from the second terminal may be implemented as: receiving a connection establishment request from the second terminal, wherein the connection establishment request includes the radio bearer configuration information. The connection establishment request may be, but is not limited to, a direct communication request (DCR).

[0144] Alternatively, receiving the radio bearer configuration information from the second terminal may be implemented as follows: receiving an RRC message from the second terminal, the RRC message including the radio bearer configuration information. Exemplarily, the second terminal sends the RRC message before switching the relay device, for example, after the first terminal establishes an end-to-end connection with the second terminal, the second terminal sends the RRC message.

[0145] As another possible implementation, S102 may be implemented as follows: the first terminal receives radio bearer configuration information from the network device. The specific implementation of S102 may be referred to below.

[0146] As a possible implementation manner, the second terminal also obtains radio bearer configuration information, the radio bearer configuration information includes first indication information, and the first indication information is used to indicate the execution of data recovery. The first indication information is used to indicate the execution of data recovery, including: the radio bearer configuration information also includes a data radio bearer DRB identifier; the first indication information is used to indicate the PDCP entity corresponding to the DRB identifier of the second terminal to execute data recovery.

[0147] Optionally, the second terminal obtains the wireless bearer configuration information, which can be implemented as: receiving the wireless bearer configuration information from the first terminal through the first relay device; or receiving the wireless bearer configuration information from the network device; or, the wireless bearer configuration information is pre-configured.

[0148] Optionally, receiving the wireless bearer configuration information from the first terminal can be implemented as: receiving a link update message from the first terminal, the link update message including the wireless bearer configuration information; the link update message is a link update acceptance message; or, receiving a connection establishment request from the first terminal, the connection establishment request including the wireless bearer configuration information; or, receiving a wireless resource control RRC message from the first terminal, the RRC message including the wireless bearer configuration information.

[0149] S103: The first terminal receives second indication information, where the second indication information is used to indicate a transmission status of the first data packet.

[0150] For example, Figure 7 After the first terminal sends data packets #100-#103 to the second terminal through the first relay device, it receives indication information, which indicates that the second terminal successfully received data packet #100 (an example of the second data packet) and the second terminal did not successfully receive data packets #101-#103 (an example of the first data packet).

[0151] As a possible implementation manner, S103 may be implemented by receiving a PDCP status report from the second terminal.

[0152] Alternatively, S103 may be implemented as follows: receiving a first identifier from a first relay device, the first identifier being the second indication information. Accordingly, the second indication information is used to indicate the transmission status of the first data packet, and may be implemented as follows: the first identifier is used to indicate the identifier of the third data packet in the first data packet, the third data packet being the identifier of the data packet with the largest identifier among the consecutive data packets successfully received by the second terminal; or, the first identifier is used to indicate: the identifier of the data packet in the first data packet that the second terminal fails to receive; or, the first identifier is used to indicate: the identifier of the data packet in the first data packet that the second terminal successfully receives. For the specific implementation of S103, please refer to the following text.

[0153] S104. The first terminal retransmits the data packets that are not successfully transmitted in the first data packet according to the first indication information and the second indication information.

[0154] For example, Figure 7 The first terminal learns, based on the second indication information, that the second terminal has not successfully received the data packets #101-#103, and then the first terminal performs data recovery and retransmits the data packets #101-#103 to the second terminal.

[0155] In the relay scenario, compared with the related art, the RLC status report cannot accurately reflect whether the receiving end has actually received the data packet, resulting in retransmission failure. In the method of the embodiment of the present application, the first terminal can accurately determine the data packets that the second terminal has not actually received based on the first indication information and the second indication information included in the wireless bearer configuration information, and retransmit these data packets, which can reduce the probability of data packet loss and improve transmission reliability.

[0156] As follows, the method of the embodiment of the present application is introduced with reference to examples of specific scenarios.

[0157] In some scenarios, a first link is established between a first terminal and a second terminal through a first relay device, and a negotiation process is performed through the first link, during which the configuration of the radio bearer configuration information is completed. Figure 8 An example of the method flow in this scenario is shown. Figure 8 , the method may include:

[0158] S101. A first terminal sends data to a second terminal through a first relay device.

[0159] S201. The second terminal decides to reselect a relay device.

[0160] Optionally, the conditions for triggering reselection of the relay device include but are not limited to at least one of the following conditions: the signal quality between the second terminal and the first relay device is lower than a threshold; the timer (Timer) corresponding to the first terminal maintained by the second terminal times out (or expires).

[0161] Optionally, the timer may be a timer for PC5 RRC configuration. The value of the timer may be understood as a period of time.

[0162] Exemplarily, the value of the timer (also referred to as the duration of the timer, the timing duration, etc.) can be pre-configured (pre-configured), or obtained through a system information block (SIB), or obtained through dedicated signaling, or obtained through other means. Exemplarily, before step S201, the second terminal sends a sidelink RRC reconfiguration (RRCReconfigurationSidelink) message to the first terminal, and starts the timer corresponding to the first terminal. If a sidelink RRC reconfiguration failure (RRCReconfigurationFailureSidelink) or sidelink RRC reconfiguration completion (RRCReconfigurationCompleteSidelink) message is received within the configured timing duration, the second terminal stops timing, otherwise the timer times out.

[0163] That is, between the first terminal and the second terminal, a first link is initially established through the first relay device. Subsequently, the first terminal or the second terminal can be triggered to reselect the relay device to better achieve information transmission between the two. For example, when the signal quality between the first relay device and the second terminal is not good, it can be triggered to reselect the second relay device, and the transmission performance between the first terminal and the second terminal can be improved through the relay of the second relay device.

[0164] Optionally, in one or more embodiments of the present application, the signal quality between devices is lower than a threshold value, which may be a reference signal receiving power (reference signal receiving power, RSRP) lower than a threshold value, or a reference signal receiving quality (reference signal receiving quality, RSRQ) lower than a threshold value, and other methods may be used to determine the signal quality between devices, which is not limited by the embodiments of the present application. It is uniformly explained here that when the signal quality between certain devices is mentioned later, various possible methods (such as RSRP or RSRQ) may also be used to determine the signal quality between devices.

[0165] In addition, one or more thresholds of the embodiments of the present application can be independently configured, and each threshold can be a different or the same threshold.

[0166] S102a: The second terminal sends a link update request to the first terminal.

[0167] S102a is an implementation of S102.

[0168] Optionally, the link update request carries a relay re-selection indication and a candidate relay list, and the candidate relay list may include the identifiers of one or more candidate relay devices. The identifier of the relay device includes but is not limited to a user information identifier (User Info ID).

[0169] Optionally, the link update request may also carry radio bearer configuration information.

[0170] S202: The first terminal reselects a second relay device.

[0171] As a possible implementation manner, the first terminal selects a target relay device (target relay UE) from the candidate relay list. Exemplarily, the target relay device reselected by the first terminal is the second relay device.

[0172] For example, the first terminal may make a selection based on whether the signal quality between the first terminal and the relay device is higher than a threshold.

[0173] S203: The first terminal returns a link update acceptance to the second terminal.

[0174] Optionally, the link update acceptance carries an identifier of the second relay device.

[0175] Optionally, the link update accept may also carry radio bearer configuration information.

[0176] For configuring the radio bearer configuration information, one implementation method is that the first terminal and the second terminal configure the radio bearer configuration information for each other, then the link update request of step S102a needs to carry the radio bearer configuration information, and the link update acceptance of step S203 virtually carries the radio bearer configuration information. Another implementation method is that the first terminal configures the radio bearer configuration information for the second terminal, and the first terminal also performs data recovery, then the link update request does not need to carry the radio bearer configuration information, and the link update acceptance needs to carry the radio bearer configuration information. Another implementation method is that the second terminal configures the radio bearer configuration information for the first terminal, and the second terminal also uses the same radio bearer configuration information to perform data recovery, then the link update request needs to carry the radio bearer configuration information, and the link update acceptance does not need to carry the radio bearer configuration information. Exemplarily, under this implementation method, all PDCP entities corresponding to the DRBs between the first terminal and the second terminal perform data recovery.

[0177] Figure 8 Taking the second terminal triggering the reselection of the relay as an example, in other embodiments, the first terminal may also trigger the reselection of the relay, send a link update request, and receive a link update acceptance. The specific implementation method can refer to the relevant description of the second terminal triggering the reselection, which will not be repeated here.

[0178] S204: A new link establishment process between the first terminal and the second terminal.

[0179] Through this process, the first terminal and the second terminal can respectively establish a connection (such as but not limited to a unicast connection) with the second relay device.

[0180] S205. The second relay device sends the split QoS information and the corresponding identifier of the second terminal to the first terminal.

[0181] S206: The second relay device sends the split QoS information and the corresponding identifier of the first terminal to the second terminal.

[0182] As a possible implementation, the second relay device performs QoS splitting, splitting the E2E QoS flow into per-hop QoS flows, and sending information about the split QoS flow (referred to as QoS information) and an identifier of the second terminal to the first terminal. Optionally, the identifier of the second terminal may be the L2 ID of the second terminal, or a local ID assigned by the second relay device to the second terminal.

[0183] Similarly, the second relay device sends the split QoS information and the identifier of the first terminal to the second terminal. The identifier may be the L2 ID of the first terminal or the local ID allocated by the second relay device to the first terminal.

[0184] In the L2 ID manner, the first terminal may determine, according to the L2 ID, that the QoS information from the second relay device is the QoS for communicating with the second terminal.

[0185] For the local ID method, the first terminal can determine, according to the QoS flow ID, that the QoS information from the second relay device is the QoS for communicating with the second terminal, and associate the local ID with the second terminal.

[0186] Optionally, the QoS information includes but is not limited to at least one of the following information: latency, transmission rate, and packet loss rate.

[0187] Among them, S205 and S206 may exist in multiple embodiments of the present application. For example, in a scenario where a relay is reselected, S205 and S206 may be executed.

[0188] S207: The first relay device sends a transmission completion indication (end indication) to the first terminal, where the transmission completion indication is used to indicate that the first relay device has finished sending data to the second terminal.

[0189] For the first terminal, after the new link with the second terminal is established, the first terminal stops sending data packets to the second terminal through the first relay device. After the new link is established, the first terminal sends data packets to the second terminal through the second relay device. Figure 8 , the first terminal sends data packet #105 to the second terminal through the second relay device.

[0190] Considering some scenarios, after the first terminal establishes a new link with the second terminal, the first relay device on the source link may still have untransmitted data packets. For example, the first terminal sends a data packet to the first relay device, but the first relay device does not have time to send it to the second terminal. As a possible implementation method, when there is a connection between the first terminals, the first relay device can continuously receive data packets from the first terminal and forward data packets to the second terminal. Figure 8 , the first terminal sends data packets #100-#104 before stopping forwarding data packets through the first relay device, then the first relay device can forward the successfully received data packets (such as data packets #100-#102, #104) among the 5 data packets to the second terminal.

[0191] After the first relay device completes transmission of the data packet from the first terminal to the second terminal, the first relay device sends a transmission completion indication to the first terminal, indicating that the first relay device has completed transmission of the data packet from the first terminal to the second terminal. After the first terminal receives the transmission completion indication from the first relay device, if there is no other service on the source link, the first terminal can release the source link.

[0192] S207 is an optional step.

[0193] S208. The first relay device sends a transmission completion indication to the second terminal.

[0194] This step is optional. The second terminal may release the source link according to the transmission completion indication.

[0195] Among them, S207 and S208 may exist in multiple embodiments of the present application. For example, Figure 8 , Fig. 9 In the corresponding scenarios, S207 and / or S208 can be executed.

[0196] S103a: The second terminal sends a PDCP status report to the first terminal. The PDCP status report includes second indication information.

[0197] Correspondingly, a packet data convergence layer protocol PDCP status report is received from the second terminal.

[0198] S103a is an implementation of S103.

[0199] As a possible implementation, the first terminal sends a PDCP status report to the second terminal when the fourth condition is met. Optionally, the fourth condition includes at least one of the following conditions: the link establishment with the second relay device is completed; the second communication configuration between the first terminal and the second relay device is obtained; a link update acceptance message is sent; a link update acceptance message is received; a transmission completion indication is received from the first relay device.

[0200] Optionally, the second communication configuration includes at least one of the following configurations: an RLC channel, and a mapping relationship between the RLC channel and the DRB.

[0201] For example, still Figure 8 After S208, the second terminal sends a PDCP status report to the first terminal through the second relay device.

[0202] For another example, after S203, the second terminal sends a PDCP status report through the first relay device. In this way, before the link is switched between the first terminal and the second terminal, the second terminal can send a PDCP status report on the source link to inform the first terminal in advance of the data packet that was not successfully received, so that the first terminal can retransmit the data packet as soon as possible after establishing a new link.

[0203] For another example, after S204, the second terminal can determine the second communication configuration of each link hop, and send a PDCP status report to the first terminal through the second relay device. In this way, since the link establishment with the second relay device is completed, the new link has been switched at this time, and the second communication configuration between the first terminal and the second relay device is obtained, so that the second terminal can send the PDCP status report on the new link with better link quality, and can ensure that the PDCP status report is successfully received by the first terminal as much as possible.

[0204] In some embodiments, the first terminal may also send a PDCP status report to indicate whether the data packet of the other terminal is successfully received. The conditions for the first terminal to send the PDCP status report can refer to the conditions for the second terminal to send the PDCP status report, which will not be repeated.

[0205] For example, Figure 8 , the PDCP status report sent by the second terminal indicates that the second terminal has not successfully received data packets #101-#103.

[0206] S104a. The first terminal retransmits the data packets that are not successfully transmitted in the first data packets according to the first indication information and the PDCP status report.

[0207] S104a is an example of an implementation manner of S104.

[0208] After receiving the PDCP status report from the second terminal, the first terminal performs a PDCP data recovery operation to retransmit the first data packet that was not successfully received by the second terminal. Exemplarily, the first terminal retransmits the PDCP SDU corresponding to COUNT=FMC or a bit in the bitmap being 0 in the PDCP status report.

[0209] The embodiment of the present application also provides a data recovery method. In some scenarios, the first link (source link) between the first terminal and the second terminal is disconnected, and the first terminal and the second terminal complete the configuration of the wireless bearer configuration information in the process of establishing a new link (second link). Fig. 9An example of a process is shown, and the process may include: S101, S301-S305, S102b, S306-S309, S103b, and S104a. The specific implementation of S101 and S104a can refer to the corresponding steps of the above embodiment, the specific implementation of S306-S309 can refer to S205-S208 of the above embodiment, and the specific implementation of S103b can refer to S103a of the above embodiment, which will not be repeated. The implementation of S301-S305 is introduced as follows:

[0210] S301. The second terminal decides to reselect a relay device.

[0211] Optionally, the conditions for triggering reselection of the relay device include but are not limited to at least one of the following conditions: RLF occurs between the second terminal and the first relay device; the signal quality (such as RSRP) between the second terminal and the first relay device is lower than a threshold; the timer of the second terminal times out, which timer can be a timer for E2E PC5 RRC configuration.

[0212] S302: The second terminal maintains a first communication configuration between the second terminal and the first terminal.

[0213] The first communication configuration includes PDCP configuration and / or service data adaptation protocol SDAP configuration. That is, when the second terminal determines that the signal quality of the source link between the second terminal and the first terminal is not good, the second terminal does not release the first communication configuration corresponding to the first terminal to prevent the data packets cached in the protocol entity from being deleted by mistake, which can reduce the probability of data packet loss and improve the reliability of data packet transmission.

[0214] As a possible implementation manner, the second terminal maintains the first communication configuration with the first terminal, which can be implemented as: satisfying the fifth condition and maintaining the first communication configuration between the first terminal and the second terminal.

[0215] The fifth condition includes at least one of the following conditions: a radio link failure RLF occurs between the second terminal and the first relay device; the signal quality between the second terminal and the first relay device is lower than an eighth threshold; a notification message is received from the first relay device, the notification message indicating that RLF occurs between the first terminal and the first relay device, or indicating that the signal quality between the first terminal and the first relay device is lower than a ninth threshold; the first timer corresponding to the first terminal times out.

[0216] As a possible implementation manner, the second terminal maintains the association relationship between the first communication configuration and the first terminal, for example, maintains the association relationship between the first communication configuration and an identifier (such as L2 ID or User Info ID) of the first terminal.

[0217] For example, determining that the fifth condition is met means that the signal quality between the first terminal and the second terminal is poor or RLF occurs. In this case, the second terminal can trigger relay reselection and maintain the first communication configuration with the first terminal to reduce the probability of packet loss.

[0218] Alternatively, the second terminal maintains the first communication configuration with the first terminal, which can be implemented as follows: the second terminal maintains the association between the first communication configuration and the E2E unicast connection, for example, maintaining the association between the first communication configuration and the ID pair of <first terminal identifier, second terminal identifier>.

[0219] S303: The first terminal receives a notification message from the first relay device.

[0220] The notification message indicates that RLF occurs between the second terminal and the first relay device, or indicates that the signal quality between the second terminal and the first relay device is lower than a second threshold.

[0221] Optionally, the notification message includes an RLF indication or a signal quality indication, and the notification message also includes an identifier of the second terminal, and the identifier of the second terminal may be, but is not limited to, an L2 ID of the second terminal, or a local ID allocated by the first relay device to the second terminal. In this way, the first terminal can learn, based on the notification message, that an RLF or poor signal quality occurs between the first terminal and the second terminal.

[0222] S304: The first terminal maintains the first communication configuration with the second terminal.

[0223] As a possible implementation manner, when the first condition is met, the second terminal maintains the first communication configuration with the second terminal.

[0224] The first condition includes: receiving a notification message from the first relay device. Following the above, after the first terminal receives the notification message, it learns that the signal quality between itself and the second terminal is poor or RLF occurs, and packet loss may occur. The first terminal maintains the first communication configuration with the second terminal to avoid packet loss caused by releasing the communication configuration.

[0225] In some other scenarios, the first condition may also be at least one of the following conditions: RLF occurs between the first terminal and the first relay device; the signal quality between the first terminal and the first relay device is lower than a first threshold; the first timer corresponding to the second terminal times out.

[0226] S305: Relay discovery and selection process.

[0227] Model A, model B, or an integrated method may be used to discover and select a relay device. In the methods of model A and model B, the terminal that triggers the reselection (such as the second terminal) selects the destination relay device. In the integrated method, the opposite terminal of the terminal that triggers the reselection (such as the first terminal) selects the destination relay device.

[0228] S102b. Establish a new link between the first terminal and the second terminal.

[0229] As a possible implementation manner, during the process of establishing a new link, radio bearer configuration information is configured.

[0230] The first terminal establishes a new link with the second terminal, including two situations:

[0231] Case 1: A direct link between the first terminal and the second terminal is established.

[0232] For example, the first terminal establishes a unicast connection with the second terminal, and the terminal of the destination relay device is selected to carry the radio bearer configuration information in the E2E DCR message.

[0233] Case 2: establishing a non-direct link between the first terminal and the second terminal.

[0234] For example, the first terminal and the second terminal respectively establish a hop-by-hop unicast connection with the second relay device, and the first terminal establishes an E2E unicast connection with the second terminal. The terminal that selects the destination relay device carries the radio bearer configuration information in the DCR message.

[0235] The embodiment of the present application also provides a data recovery method. In the above, the first terminal obtains the radio bearer configuration information from the second terminal as an example. In other scenarios, the first terminal can also obtain the radio bearer configuration information from the network device. When the first terminal or the second terminal is in a connected state, such as Fig.10 An example of a process is shown, which may include S101, S401, S402, S102c1, S102c2, S103 and S104. The specific implementation of S401 can refer to the process of establishing a new link in the above embodiment, and the specific implementation of S103 and S104 can refer to the above, which will not be repeated. S402, S102c1, S102c2 are introduced as follows:

[0236] S402: The second terminal sends information about a new link to the base station.

[0237] Optionally, the information of the new link may include but is not limited to the identification of the first terminal and the second relay device. Optionally, the identification of the terminal includes but is not limited to the L2 ID. Exemplarily, after establishing a new link with the first terminal, the second terminal in a connected state may report the unicast connection information of the new link to the base station, so that the base station knows that the new link is a link between the first terminal and the second terminal, and the relay device of the new link is the second relay device.

[0238] S102c1. The base station sends radio bearer configuration information to the second terminal.

[0239] Exemplarily, after receiving the radio bearer configuration information, the first terminal sends a PDCP status report to the first terminal. The first terminal retransmits the PDCP SDU for which the RLC layer does not indicate successful transmission.

[0240] The wireless bearer configuration information includes first indication information, and the first indication information is used to indicate the execution of data recovery. Optionally, the first indication information is used to indicate the execution of data recovery, including: the wireless bearer configuration information also includes the first configuration information; the first indication information is used to indicate that the PDCP entity corresponding to the first DRB identifier of the first terminal executes data recovery; the first DRB identifier is the DRB identifier corresponding to the first configuration information. Optionally, the first configuration information may be a Uu Config Index, or may be other information indicating the configuration of the Uu port.

[0241] S102c2. The second terminal sends radio bearer configuration information to the first terminal.

[0242] S102c1 and S102c2 are an implementation method of S102.

[0243] Fig.10 Taking the second terminal reporting the new link information to the base station as an example, in other embodiments, the first terminal may report the new link information and receive the wireless bearer configuration information from the base station, and then the first terminal sends the wireless bearer configuration information to the second terminal.

[0244] In some other embodiments, the radio bearer configuration information may also be pre-configured, for example, pre-defined by a protocol.

[0245] In some other embodiments, the radio bearer configuration information may also be carried in the SIB.

[0246] In one implementation, the first terminal or the second terminal does not perform the above data recovery process in the initial connection establishment process because no data is transmitted. Data recovery is performed by default when switching the relay device. The initial connection can be a direct connection or an indirect connection. Exemplarily, in this implementation, all PDCP entities corresponding to the DRB between the first terminal and the second terminal perform data recovery.

[0247] In another implementation, if the terminal is in a connected state, it may execute such as Fig.10 Corresponding data recovery method. If the terminal is in other states, you can recover data as follows:

[0248] If the terminal is in an idle state or an inactive state, the terminal can obtain a SIB message from the base station. In some examples, if the SIB message includes radio bearer configuration information, the terminal ignores the radio bearer configuration information when establishing an initial connection with the other end. When the two subsequently switch to a new link, PDCP data recovery is performed. In some examples, if the SIB message does not include radio bearer configuration information, the terminal does not perform PDCP data recovery during the initial connection and subsequent switching process.

[0249] If the terminal is in the OoC state, when the terminal establishes an initial connection with the other end, the radio bearer configuration information in the pre-configuration is ignored, and when switching to a new link later, PDCP data recovery is performed.

[0250] In another implementation, the terminal performs data recovery according to preconfiguration in any state.

[0251] In another implementation, the terminal performs data recovery according to preconfiguration in the OoC state, and performs data recovery according to SIB in other states.

[0252] The embodiment of the present application also provides a data recovery method, after the RLC layer of the terminal receives the (acknailed, ACK) message of the RLC layer, it delays for a period of time to send an indication of successful data packet transmission to the PDCP layer, so that when the PDCP status report of the other end is received, the data packet cached by the terminal still exists. Fig.11 An example of a process is shown, which may include:

[0253] S101. A first terminal sends a first data packet through a first relay device.

[0254] S501. A first RLC entity of a first terminal receives an ACK message from a first relay device, where the ACK message is used to indicate that the first relay device successfully receives a second data packet in a first data packet.

[0255] For example, Fig.11The second data packet successfully received by the first relay device is the data packet corresponding to #100-#102.

[0256] S102: The first terminal obtains radio bearer configuration information, where the radio bearer configuration information includes first indication information, and the first indication information is used to instruct execution of data recovery.

[0257] S103a. The first terminal receives a PDCP status report.

[0258] S502: After a delay of a first time period, the first RLC entity of the first terminal sends an indication of successful transmission of a second data packet to the PDCP entity of the first terminal.

[0259] Optionally, the first RLC entity sends an indication of successful transmission to the PDCP entity, which may be directly transmitted or sent in other ways without limitation.

[0260] Optionally, the first duration is the duration of a second timer, and the second timer corresponds to the second data packet.

[0261] As a possible implementation method, after the RLC entity of the first terminal receives the RLC status report, it starts the second timer corresponding to the first data packet; the duration of the second timer is the first duration; when the second timer times out, a successful transmission indication is sent. That is, a delay timer is introduced, which can be recorded as Timer#2, which is used to control the RLC entity to delay for a period of time to indicate to the PDCP layer that the data transmission is successful. When the RLC entity receives the RLC status report fed back by the relay device, it starts Timer#2 for the RLC SDU indicated to have been successfully transmitted. After the timer reaches the timing duration, the RLC layer indicates to the PDCP layer that the corresponding data packet has been successfully transmitted. Exemplarily, the RLC layer receives RLC status report 1, indicating that packet 1 is successfully transmitted, and then starts Timer#2 corresponding to packet 1. Afterwards, the RLC layer receives RLC status report 2, indicating that packet 2 is successfully transmitted, and then starts Timer#2 corresponding to packet 2.

[0262] As a possible implementation, the first terminal receives configuration information of the second timer from the second terminal, or receives configuration information of the second timer from the first relay device; or receives a link update message, the link update message includes configuration information of the second timer; the configuration information of the second timer includes the first duration. Or, the configuration information of the second timer is preconfigured. This embodiment of the present application does not limit this.

[0263] For example, the link update request or link update accept message carries the timer configuration information. For example, the link update request or link update accept message carries the data recovery indication and the timer configuration information.

[0264] As a possible implementation manner, receiving configuration information of a second timer from a first relay device includes:

[0265] Meeting the second condition, receiving configuration information of a second timer from the first relay device;

[0266] The second condition includes at least one of the following conditions: the signal quality between the first relay device and the first terminal is lower than a third threshold; the signal quality between the first relay device and the second terminal is lower than a fourth threshold; the load of the first relay device is higher than a fifth threshold.

[0267] For example, the first relay device sends an RRC message to the first terminal, and the RRC message carries timer configuration information. In this way, when the signal quality between the first terminal and the second terminal is not good, the first relay device configures a timer for the first terminal, so that the first terminal can delay indicating to the PDCP layer that the data transmission is successful after receiving the RLC status report, so as to avoid the PDCP entity from releasing data incorrectly, resulting in packet loss. Or, when the load of the first relay device is higher than the threshold, it may not be able to forward some of the data packets in time, and this method is used to reduce the probability of data packet loss.

[0268] As a possible implementation, receiving configuration information of a second timer from a second terminal includes: receiving configuration information of a second timer from a second terminal when a third condition is satisfied. The third condition includes at least one of the following conditions: signal quality between the first relay device and the first terminal is lower than a sixth threshold; signal quality between the first relay device and the second terminal is lower than a seventh threshold; a third timer corresponding to the second terminal times out. The third timer may be a timer for E2E PC5 RRC configuration.

[0269] For example, the second terminal sends an RRC message to the first terminal, and the RRC message carries timer configuration information, such as the value of Timer#2. Optionally, after the second terminal sends the RRC message, it also applies the same value of Timer#2. For another example, the second terminal sends an RRC message to the first terminal, and the RRC message carries timer configuration information, such as the value of Timer#2. And, the first terminal sends an RRC message to the second terminal, and carries the value of Timer#2 in the RRC message. That is, the terminals configure the value of Timer#2 for each other.

[0270] Optionally, the timing duration is the duration corresponding to the maximum number of RLC retransmissions.

[0271] S104a. The first terminal retransmits the data packets (such as packets #101-#103) that are not successfully transmitted in the first data packet according to the first indication information and the PDCP status report.

[0272] Compared with the related art, after the RLC entity receives the ACK message indicating the successful transmission of packet #100-102, it notifies the PDCP entity that the data transmission is successful, and the PDCP discards the packet #100-102 accordingly. The technical solution of the embodiment of the present application is as follows: Fig.11 After the RLC entity of the first terminal receives the ACK message indicating the successful transmission of packet #100-102, it delays for a period of time to indicate to the PDCP entity that packet #100-102 has been successfully transmitted, so that when receiving the PDCP status report, the PDCP entity does not know the reception status of packet #100-102, and therefore does not delete the packet #101-102 that the second terminal actually failed to receive. In this way, the PDCP entity of the first terminal accurately learns that the second terminal has not successfully received packet #101-#103 based on the indication of the PDCP status report, and retransmits the packet #101-#103 that has not been deleted, thereby improving the reliability of data packet transmission.

[0273] The embodiment of the present application also provides a data recovery method, in which the first relay device feeds back the identifier of the data packet successfully transmitted by the second hop to the first terminal, so that the first terminal knows that the second terminal has not actually received the data packet successfully, and retransmits the part of the data packet accordingly. Fig.12 An example of the process is shown, which may include the following steps:

[0274] S101. A first terminal sends data through a first relay device.

[0275] S601. A first RLC entity of a first terminal receives an ACK message from a first relay device.

[0276] S602: The first terminal discards the ACK message.

[0277] Discarding can also be understood as ignoring. That is, after receiving the ACK message from the first relay device, the RLC entity of the first terminal ignores the ACK message reflecting the transmission status of the first hop and does not indicate successful transmission to the PDCP entity.

[0278] S602 is an optional step, and in some embodiments, S602 may also be replaced by S502. Alternatively, it may be replaced by other steps, so that the first terminal determines the data packets that need to be retransmitted not based on the RLC status report reflecting the transmission status of a single hop, but based on the PDCP status report or the first identifier that can reflect the transmission status of multiple hops.

[0279] In some other embodiments, Fig.11 The S502 in the example can also be replaced by S602.

[0280] S102: The first terminal obtains radio bearer configuration information to indicate data recovery.

[0281] S103c. The first relay device sends a first identifier to the first terminal.

[0282] S103c is an implementation of S103.

[0283] In one or more embodiments of the present application, S103a, S103b, and S103c can be replaced with each other. Accordingly, when a solution includes S103a or S103b, S104 can be implemented as S104a, and when a solution includes S103c, S104 can be implemented as S104b. For example, Fig.12 S103c in can be replaced by S103a, and accordingly, Fig.12 Replace S104b with S104a.

[0284] Optionally, the first identifier is used to indicate the identifier of the third data packet in the first data packet, and the third data packet is the data packet with the largest identifier among the consecutive data packets successfully received by the second terminal; or, the first identifier is used to indicate: the identifier of the data packet in the first data packet that the second terminal fails to receive; or, the first identifier is used to indicate: the identifier of the data packet in the first data packet that the second terminal successfully receives. In this way, the first terminal can learn the data packets that the second terminal actually failed to receive based on the first identifier, and perform data packet retransmission accordingly.

[0285] Optionally, the identifier of the data packet may be, but is not limited to, a PDCP sequence number (SN). This document mainly takes the PDCP SN as an example, but this does not constitute a limitation on the identifier of the data packet.

[0286] The data packet with the largest identifier among the data packets with consecutive identifiers successfully received by the second terminal can also be understood as the data packet with the largest identifier among the data packets successfully sent sequentially and continuously by the first terminal to the second terminal.

[0287] Exemplarily, the first relay device sends 6 data packets to the second terminal, and the PDCP SN numbers are 1, 2, 3, 4, 5, and 6. The data packets with SN numbers 1, 2, 3, and 5 are successfully transmitted to the second terminal, and the data packets with SN numbers 4 and 6 are not successfully transmitted to the second terminal.

[0288] In some examples (Example 1), the first identifier fed back by the first relay device to the first terminal may indicate the highest SN number 3 among SN numbers 1, 2, and 3, indicating that the data packets with SN numbers 1, 2, and 3 are transmitted successfully.

[0289] In some other examples (Example 2), the first identifier fed back by the first relay device to the first terminal may be: SN number 4, 6, and the first identifier indicates that the data packets with SN numbers 4 and 6 are not successfully transmitted to the second terminal.

[0290] In some other examples (Example 3), the first identifier fed back by the first relay device to the first terminal may be: SN number 1, 2, 3, 5, and the first identifier indicates that the data packets with SN numbers 1, 2, 3, 5 are successfully transmitted to the second terminal.

[0291] Optional, such as Fig.12 Before step S103c, the first terminal may execute S603: sending the length information of the identifier of the data packet to the first relay device. Correspondingly, the first relay device receives the length information of the identifier of the data packet from the first terminal. In this way, after the first terminal indicates the PDCP SN length to the relay device, the relay device may determine the PDCP SN number of the data packet according to the length of the PDCP SN, and indicate to the first terminal the PDCP SN of the data packet that the second terminal has not successfully received, and / or indicate the PDCP SN of the data packet that the second terminal has successfully received. For example, if the length of the PDCP SN number is 12 bits, when forwarding a data packet, the relay device may determine that the first 12 bits of the data packet are the PDCP SN number corresponding to the data packet.

[0292] The first terminal sends the length information (PDCP SN length) of the identifier of the data packet to the first relay device, which can be implemented in any of the following ways:

[0293] Method 1: Before sending a data packet, the first terminal sends the length information of the data packet identifier to the first relay device. For example, the PDCP SN length is added to the configuration information, and the configuration information carrying the PDCP SN length and the RLC channel is sent to the first relay device. Alternatively, the PDCP SN length is indicated to the first relay device in other configuration information. The embodiments of the present application do not limit this.

[0294] Mode 2: When at least one of the following conditions is met, the first terminal sends the length information of the identifier of the data packet: the signal quality between the first terminal and the first relay device is lower than the threshold; the timer of the first terminal times out. For example, the timer is a timer for E2E PC5 RRC configuration. In other words, when the quality is not good, the terminal sends the length information of the identifier of the data packet to the relay device so that the relay device can identify the identifier of the data packet (such as the PDCP SN number) based on it.

[0295] Corresponding to mode 1, when at least one of the following conditions is met, the first terminal sends indication information #1 to the first relay device, and the indication information #1 is used to instruct the first relay device to feedback the transmission status of the second-hop data packet (such as the PDCP SN number of the successfully transmitted data packet): the signal quality between the first terminal and the first relay device is lower than the threshold; the timer of the first terminal times out. For example, the timer can be a timer for E2EPC5 RRC configuration.

[0296] Alternatively, the first terminal may also use other methods to send the length information of the identifier of the data packet at other times or under other conditions without limitation.

[0297] As a possible implementation, the first relay device feeds back the first identifier to the first terminal when certain conditions are met, such as the SN number of the data packet successfully transmitted by the second hop. For example, after receiving the length information (such as the PDCP SN length) of the identifier of the data packet from the first terminal, the first relay device starts to feed back the first identifier to the first terminal. For another example, after receiving the indication information #1 from the first terminal, the first relay device feeds back the first identifier to the first terminal.

[0298] S104b: The first terminal retransmits the data packets that are not successfully transmitted in the first data packets according to the first indication information and the first identifier.

[0299] S104b is a possible implementation of S104.

[0300] After receiving the first identifier from the first relay device, the first terminal determines the data packets that have not been successfully received by the second terminal according to the first identifier, and retransmits the part of the data packets.

[0301] For example, corresponding to the above example 1, the first terminal retransmits the data packets with SN numbers greater than the highest SN number (3) in sequence, that is, retransmits the data packets with SN numbers 4, 5, and 6.

[0302] Exemplarily, in one or more embodiments of the present application, if the source link is available, the first terminal may retransmit through the new link, or retransmit on the source link. For example, if the new link has not been established and the source link is still available, the first terminal may retransmit on the source link.

[0303] For another example, corresponding to the above example 2, the first terminal retransmits the data packets with SN numbers 4 and 6.

[0304] The embodiment of the present application also provides a data recovery method. Considering that the source relay device (such as the first relay device) knows the transmission status of the second hop, the first relay device can forward the data packet that the second terminal has not successfully received to the destination relay device (the second relay device). Fig.13 An example of the process is shown, which may include the following steps:

[0305] S101. A first terminal sends a first data packet to a second terminal through a first relay device.

[0306] S701: A first terminal sends an identifier of a second relay device to a first relay device, where the identifier of the second relay device is used to instruct the first relay device to establish a communication connection with the second relay device.

[0307] After determining the second relay device, the first terminal or the second terminal can send the identifier of the second relay device to the first relay device. For example, User Info ID or L2 ID or other identifiers used to indicate the second relay device. In this way, the first relay device can know that the two terminals have selected the second relay device, so that the data packets that are not successfully received by the second terminal can be forwarded through the second relay device in the future.

[0308] As a possible implementation, optionally, in order to ensure that the first relay device can forward the data packet to the second relay device as much as possible, the first relay device participates in the selection process of the second relay device. For example, the first relay device sends the RSRP measurement result to the first terminal (or the second terminal), and the first terminal (or the second terminal) selects a relay device with an RSRP higher than a threshold between the first relay device and the first relay device as the second relay device.

[0309] S702: The first relay device establishes a communication connection with the second relay device.

[0310] As a possible implementation manner, S702 may be implemented as follows: the first relay device establishes a communication connection (such as a unicast connection) with the second relay device according to the identifier of the second relay device.

[0311] As a possible implementation, the first relay device establishes a communication connection with the second relay device according to the identifier of the second relay device, which can be implemented as follows: the first relay device sends a connection establishment request (such as a DCR message) to the second relay device, and the connection establishment request is used to request to establish a communication connection between the first relay device and the second relay device. The connection establishment request carries the identifier of the first terminal and the identifier of the second terminal (such as User Info ID). Optionally, the connection establishment request may also carry indication information #2, and indication information #2 is used to indicate that the communication connection requested to be established is used to forward data packets between the first terminal and the second terminal. After receiving the connection establishment request, the second relay device replies to the first relay device with a connection establishment confirmation (such as a direct communication acknowledgement (DCA) message). In this way, the second relay device can know that the communication connection between the second relay device and the first relay device is used to forward data packets between the first terminal and the second terminal. This enables the second relay device to forward data packets received by this communication connection to the correct terminal.

[0312] The method in which the connection establishment request does not carry the indication information #2 can be called an implicit method, and the IDs of the two terminals carried in the connection establishment request can implicitly indicate the forwarding of data packets between the two terminals. The method in which the connection establishment request carries the indication information #2 can be called an explicit method, and the indication information #2 explicitly indicates the forwarding of data packets between the two terminals.

[0313] As a possible implementation, the second relay device may send configuration information #1 to the first relay device, where the configuration information #1 includes the local ID allocated by the second relay device to the first terminal and the local ID allocated to the second terminal. For example, the local ID is allocated by the adaptation layer of the second relay device.

[0314] S703: The first relay device sends the fourth data packet in the second data packet to the second relay device.

[0315] The second data packet is the data packet successfully received by the first relay device in the first data packet, and can also be understood as the data packet successfully transmitted by the first hop. The fourth data packet is the data packet not successfully received by the second terminal in the second data packet, and can also be understood as the data packet successfully transmitted by the second hop. Fig.13 , the first data packets sent by the first terminal to the second terminal via the first relay device are: packets #100-#103. Among them, the second data packets successfully received by the first relay device (successfully transmitted at the first hop) are: packets #100-#102. Among them, the data packets not successfully received by the second terminal (successfully transmitted at the second hop) are: packets #101-#102. The first relay device sends packets #101-#102 that the second terminal did not successfully receive to the second relay device.

[0316] Optionally, the fourth data packet includes the local ID assigned by the second relay device to the first terminal, the local ID assigned to the second terminal, and the DRB ID. In this way, the second relay device can know that the fourth data packet is a data packet between the first terminal and the second terminal, and forward the fourth data packet to the second terminal accordingly.

[0317] S704: The second relay device sends a fourth data packet to the second terminal.

[0318] As a possible implementation manner, the second relay device forwards the fourth data packet that the second terminal has not successfully received to the second terminal according to the local ID and the DRB ID of the second terminal included in the fourth data packet.

[0319] Optional, Fig.13 The method shown may also include S102-S104. For example, Fig.13, the second terminal successfully receives the fourth data packet (#101-#102) from the second relay device, then the data packets successfully received by the second terminal are: #100-102. Afterwards, the second terminal feeds back a PDCP status report to the first terminal, indicating that the second terminal did not successfully receive packet #100 (S103). The first terminal retransmits packet #100 according to the PDCP status report. For another example, the first relay device sends a first identifier to the first terminal, which is used to indicate the identifier of packet #100 that the second terminal did not successfully receive. The first terminal retransmits packet #100 according to the first identifier.

[0320] It should be noted that the above-mentioned multiple embodiments can be combined and the combined scheme can be implemented. Optionally, some operations in the process of each method embodiment are optionally combined, and / or the order of some operations is optionally changed. In addition, the execution order between the steps of each process is only exemplary and does not constitute a limitation on the execution order between the steps. There can also be other execution orders between the steps. It is not intended to indicate that the execution order is the only order in which these operations can be performed. A person of ordinary skill in the art will think of a variety of ways to reorder the operations described herein. In addition, it should be noted that the process details involved in a certain embodiment of this article are also applicable to other embodiments in a similar manner, or different embodiments can be used in combination.

[0321] In addition, some steps in the method embodiment may be equivalently replaced by other possible steps. Alternatively, some steps in the method embodiment may be optional and may be deleted in certain usage scenarios. Alternatively, other possible steps may be added in the method embodiment. Alternatively, the execution subject (such as a functional module) of some steps in the method embodiment may be replaced by other execution subjects.

[0322] Furthermore, the above method embodiments may be implemented separately or in combination.

[0323] Some other embodiments of the present application provide a device, which may be the above-mentioned first terminal or second terminal or first relay device or second relay device or corresponding components (such as chip systems), etc. The device may include: a memory and one or more processors. The memory and the processor are coupled. The memory is used to store computer program code, and the computer program code includes computer instructions. When the processor executes the computer instructions, the device may execute the various functions or steps executed by the corresponding device in the above-mentioned method embodiment. The structure of the device can refer to Figure 6 The equipment (device) shown.

[0324] The core structure of the device can be expressed as Fig.14 In the structure shown, the device includes: a processing module 1301 and a storage module 1303.

[0325] The processing module 1301 may include at least one of a central processing unit (CPU), an application processor (AP) or a communication processor (CP). The processing module 1301 may perform operations or data processing related to control and / or communication of at least one of other elements of the user equipment.

[0326] The storage module 1303 may include a volatile memory and / or a non-volatile memory. The storage module is used to store at least one instruction or data related to other modules of the user equipment device.

[0327] Optionally, a communication module 1305 is also included to support personal devices (via a communication network) to communicate with other personal devices. For example, the communication module can be connected to the network via wireless communication or wired communication to communicate with other personal devices or network servers. Wireless communication can use at least one of cellular communication protocols, such as long-term evolution (LTE), 5G, 6G, advanced long-term evolution (LTE-A), code division multiple access (CDMA), wideband code division multiple access (WCDMA), universal mobile telecommunications system (UMTS), wireless broadband (WiBro) or global mobile communication system (GSM). Wireless communication may include, for example, short-range communication. Short-range communication may include at least one of wireless fidelity (Wi-Fi), Bluetooth, near field communication (NFC), magnetic stripe transmission (MST) or GNSS.

[0328] It should be noted that each functional module of the device can execute one or more steps in the above method embodiment.

[0329] The present application also provides a chip system, such as Fig.15 As shown, the chip system includes at least one processor 1401 and at least one interface circuit 1402. The processor 1401 and the interface circuit 1402 can be interconnected via lines. For example, the interface circuit 1402 can be used to receive signals from other devices (such as the memory of the device). For another example, the interface circuit 1402 can be used to send signals to other devices (such as the processor 1401). Exemplarily, the interface circuit 1402 can read the instructions stored in the memory and send the instructions to the processor 1401. When the instructions are executed by the processor 1401, the device can execute the various steps in the above embodiments. Of course, the chip system can also include other discrete devices, which are not specifically limited in the embodiments of the present application.

[0330] An embodiment of the present application also provides a computer storage medium, which includes computer instructions. When the computer instructions are executed on the above-mentioned device, the device executes the corresponding functions or steps in the above-mentioned method embodiment.

[0331] The embodiment of the present application also provides a computer program product. When the computer program product is run on a computer, the computer is enabled to execute the corresponding functions or steps in the above method embodiment.

[0332] Through the description of the above implementation methods, technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0333] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0334] The units described as separate components may or may not be physically separated, and the components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple different places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0335] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0336] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium, including several instructions to enable a device (which can be a single-chip microcomputer, chip, etc.) or a processor (processor) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read only memory (ROM), random access memory (RAM), disk or optical disk and other media that can store program code.

[0337] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application shall be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A data recovery method, characterized in that: The method is applied to a first terminal, comprising: Sending a first data packet to a second terminal through a first relay device; Acquire radio bearer configuration information, where the radio bearer configuration information includes first indication information, where the first indication information is used to indicate execution of data recovery; receiving second indication information, where the second indication information is used to indicate a transmission status of the first data packet; According to the first indication information and the second indication information, data packets that are not successfully transmitted in the first data packet are retransmitted.

2. The method according to claim 1, characterized in that: The first indication information is used to instruct the execution of data recovery, including: the radio bearer configuration information also includes a data radio bearer DRB identifier; the first indication information is used to instruct the PDCP entity corresponding to the DRB identifier of the first terminal to execute data recovery; Or, the first indication information is used to indicate the execution of data recovery, including: the wireless bearer configuration information also includes first configuration information; the first indication information is used to instruct the PDCP entity corresponding to the first DRB identifier of the first terminal to perform data recovery; the first DRB identifier is the DRB identifier corresponding to the first configuration information.

3. The method according to claim 1 or 2, characterized in that: Also includes: A transmission completion indication is received from the first relay device, where the transmission completion indication is used to indicate that the first relay device has completed sending the first data packet to the second terminal.

4. The method according to any one of claims 1 to 3, characterized in that: Obtain radio bearer configuration information, including: Receiving, through the first relay device, the radio bearer configuration information from the second terminal; or, receiving the radio bearer configuration information from the network device; Alternatively, the radio bearer configuration information is pre-configured.

5. The method according to claim 4, characterized in that Receiving the radio bearer configuration information from the second terminal includes: receiving a link update message from the second terminal, wherein the link update message includes the radio bearer configuration information; the link update message is a link update request message; or, receiving a connection establishment request from the second terminal, the connection establishment request including the radio bearer configuration information; Or, receiving a radio resource control RRC message from the second terminal, where the RRC message includes the radio bearer configuration information.

6. The method according to any one of claims 1 to 5, characterized in that: Receiving second indication information includes: A packet data convergence layer protocol (PDCP) status report is received from the second terminal, where the PDCP status report includes the second indication information.

7. The method according to any one of claims 1 to 5, characterized in that: Receiving second indication information includes: receiving a first identifier from the first relay device, where the first identifier is the second indication information; The second indication information is used to indicate the transmission status of the first data packet, including: the first identifier is used to indicate the identifier of the third data packet in the first data packet, and the third data packet is the data packet with the largest identifier among the consecutive data packets successfully received by the second terminal; or, the first identifier is used to indicate: the identifier of the data packet in the first data packet that the second terminal fails to receive; or, the first identifier is used to indicate: the identifier of the data packet in the first data packet that the second terminal successfully receives.

8. The method according to claim 7, characterized in that Before receiving the first identifier from the first relay device, the method further includes: The length information of the identifier of the data packet is sent to the first relay device.

9. The method according to any one of claims 1 to 8, characterized in that: Also includes: If a first condition is met, a first communication configuration between the first terminal and the second terminal is maintained; the first communication configuration includes a PDCP configuration and / or a service data adaptation protocol SDAP configuration; The first condition includes at least one of the following conditions: a radio link failure RLF occurs between the first terminal and the first relay device; the signal quality between the first terminal and the first relay device is lower than a first threshold; a notification message is received from the first relay device, and the notification message indicates that an RLF occurs between the second terminal and the first relay device, or indicates that the signal quality between the second terminal and the first relay device is lower than a second threshold; the first timer corresponding to the second terminal times out.

10. The method according to any one of claims 1 to 9, characterized in that: Also includes: The first radio link control RLC entity of the first terminal receives an ACK message from the first relay device, where the ACK message is used to indicate that the first relay device successfully receives the second data packet in the first data packet; After a first delay, the first RLC entity of the first terminal sends an indication of successful transmission of the second data packet to the PDCP entity of the first terminal; The first duration is the duration of a second timer, and the second timer corresponds to the second data packet.

11. The method according to claim 10, characterized in that Receiving configuration information of the second timer from the second terminal, or receiving configuration information of the second timer from the first relay device; or receiving a link update message, wherein the link update message includes the configuration information of the second timer; The configuration information of the second timer includes the first duration.

12. The method according to claim 11, characterized in that Receiving configuration information of the second timer from the first relay device includes: Meeting a second condition, receiving configuration information of the second timer from the first relay device; The second condition includes at least one of the following conditions: the signal quality between the first relay device and the first terminal is lower than a third threshold; the signal quality between the first relay device and the second terminal is lower than a fourth threshold; the load of the first relay device is higher than a fifth threshold.

13. The method according to claim 11, characterized in that Receiving configuration information of the second timer from the second terminal includes: satisfying a third condition, receiving configuration information of the second timer from the second terminal; The third condition includes at least one of the following conditions: the signal quality between the first relay device and the first terminal is lower than a sixth threshold; the signal quality between the first relay device and the second terminal is lower than a seventh threshold; the third timer corresponding to the second terminal times out.

14. The method according to any one of claims 1 to 9, characterized in that: Also includes: Receiving an ACK message from the first relay device; The ACK message is discarded.

15. The method according to any one of claims 1 to 14, characterized in that: Also includes: An identifier of a second relay device is sent to the first relay device, where the identifier of the second relay device is used to instruct the first relay device to establish a communication connection with the second relay device.

16. A data recovery method, characterized in that: The method is applied to a second terminal, comprising: Receiving, through the first relay device, a first data packet from the first terminal; Acquire radio bearer configuration information, where the radio bearer configuration information includes first indication information, where the first indication information is used to indicate execution of data recovery; Send a packet data convergence layer protocol PDCP status report; the PDCP status report is used to indicate the transmission status of the first data packet.

17. The method according to claim 16, characterized in that The first indication information is used to instruct execution of data recovery, including: The radio bearer configuration information also includes a data radio bearer DRB identifier; the first indication information is used to instruct the PDCP entity corresponding to the DRB identifier of the second terminal to perform data recovery.

18. The method according to claim 16 or 17, characterized in that Obtain radio bearer configuration information, including: Receiving, through the first relay device, the radio bearer configuration information from the first terminal; or, receiving the radio bearer configuration information from a network device; Alternatively, the radio bearer configuration information is pre-configured.

19. The method according to claim 18, characterized in that Receiving the radio bearer configuration information from the first terminal includes: receiving a link update message from the first terminal, wherein the link update message includes the radio bearer configuration information; the link update message is a link update accept message; or, receiving a connection establishment request from the first terminal, the connection establishment request including the radio bearer configuration information; Or, receiving a radio resource control RRC message from the first terminal, where the RRC message includes the radio bearer configuration information.

20. The method according to any one of claims 16 to 19, characterized in that: Also includes: If a fourth condition is met, a PDCP status report is sent to the second terminal; The fourth condition includes at least one of the following conditions: the link establishment with the second relay device is completed; the second communication configuration between the first terminal and the second relay device is obtained; a link update request message is sent; a link update acceptance message is received; a transmission completion indication is received from the first relay device; The second relay device is a relay device selected by the first terminal or the second terminal; the second communication configuration includes at least one of the following configurations: a radio link control RLC channel, and a mapping relationship between the RLC channel and the DRB.

21. The method according to any one of claims 16 to 20, characterized in that: Also includes: If a first condition is met, a first communication configuration between the first terminal and the second terminal is maintained; the first communication configuration includes a PDCP configuration and / or a Service Data Adaptation Protocol SDAP configuration; The fifth condition includes at least one of the following conditions: a radio link failure RLF occurs between the second terminal and the first relay device; the signal quality between the second terminal and the first relay device is lower than an eighth threshold; a notification message is received from the first relay device, and the notification message indicates that an RLF occurs between the first terminal and the first relay device, or indicates that the signal quality between the first terminal and the first relay device is lower than a ninth threshold; the first timer corresponding to the first terminal times out.

22. A data recovery method, characterized in that: The method is applied to a first relay device, comprising: receiving a first data packet from a first terminal; Sending the first data packet to the second terminal; A first identifier is sent to the first terminal, where the first identifier is used to indicate an identifier of a third data packet in the first data packet, where the third data packet is the data packet with the largest identifier among consecutive data packets successfully received by the second terminal; or, the first identifier is used to indicate an identifier of a data packet in the first data packet that the second terminal fails to receive; or, the first identifier is used to indicate an identifier of a data packet in the first data packet that the second terminal successfully receives.

23. The method according to claim 22, characterized in that Before sending the first identifier to the first terminal, the method further includes: Receive length information of the identifier of the data packet from the first terminal.

24. The method according to claim 22 or 23, characterized in that Also includes: After sending the first data packet, a transmission completion indication is sent to the first terminal, where the transmission completion indication is used to indicate that the first relay device has completed sending the first data packet to the second terminal.

25. A computer-readable storage medium, characterized in that: The method comprises a program or an instruction. When the program or the instruction is executed, the method according to any one of claims 1 to 15 is implemented, or the method according to any one of claims 16 to 21 is implemented, or the method according to any one of claims 22 to 24 is implemented.

26. An electronic device, characterized in that: The electronic device comprises a processor and a memory; The memory is used to store computer-executable instructions. When the device is running, the processor executes the computer-executable instructions stored in the memory to enable the device to execute the method as described in any one of claims 1 to 15, or execute the method as described in any one of claims 16 to 21, or execute the method as described in any one of claims 22 to 24.

27. A data recovery system, characterized in that: The system includes a first terminal for implementing the method described in any one of claims 1 to 15, a second terminal for implementing the method described in any one of claims 16 to 21, and a first relay device for implementing the method described in any one of claims 22 to 24.

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