Communication method and device

Abstract

The present application provides a communication method and device that can solve the problem of data packet loss when the terminal performs path switching / path switch in a relay scenario where data packets need to be transferred, such as a sidelink relay, thereby improving data transmission efficiency. The method includes: a remote terminal receives a first indication message from a relay terminal. The remote terminal receives a second indication message. The remote terminal determines the second data based on the first indication message and the second indication message. Alternatively, the remote terminal determines the second data based on the second indication message. The remote terminal sends the second data to the relay terminal or the second access network device. Lossless transmission of downlink data is achieved when the terminal switches, ensuring business continuity.

Description

Technical Field

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

[0002] Vehicle to everything (V2X) refers to the interconnection between vehicles and the outside world through devices configured on vehicles and various communication technologies, such as vehicle-to-vehicle, vehicle-to-people, vehicle-to-roadside infrastructure, vehicle-to-network, etc. The 3rd Generation Partnership Project (3GPP) International Standardization Organization discussed the standardization of New Radio (NR) V2X in R16. NR V2X is further studied and standardized based on Long Term Evolution (LTE) V2X. The communication architecture of NR V2X includes two communication interfaces, namely the PC5 interface and the Uu interface. The NR PC5 interface is a direct communication interface between V2X user equipment (UE). The direct communication link between V2X UEs is also defined as a sidelink or sidelink (SL).

[0003] During the NR R17 standardization project discussion, two sidelink relay scenarios were considered: UE-to-Network relay and UE-to-UE relay. UE-to-Network relay primarily addresses insufficient network coverage. By relaying data through relay nodes, remote UEs located at the cell edge or outside of the cell can communicate with access network equipment, thereby enhancing network coverage. During UE-to-Network relay communication, there is a remote UE and one or more relay terminals (such as relay UEs). Data and signaling can be transmitted between the remote terminal and the access network equipment through the relay terminals. Because both the remote terminal and the relay terminal are mobile, if the remote terminal discovers that the link with the relay terminal is deteriorating and the link with other relay terminals is better, or the direct link with the access network equipment / opposite UE is better, the remote terminal can communicate with the access network equipment / opposite UE through other relay terminals, or directly with the access network equipment / opposite UE. This process is similar to UE handover on the Uu interface and is sometimes referred to as a path switch.

[0004] In a scenario where the UE and the access network device are communicating directly, if the UE receives a radio link control (RLC) status report indicating that a data packet has been successfully transmitted at the RLC layer entity, then the data packet must have been successfully transmitted to the access network device. However, in relay scenarios where data packets need to be transferred, such as sidelink relay, a data packet sent by the packet data convergence protocol (PDCP) layer entity on the sending side needs to be transmitted over two hops before it can reach the PDCP layer entity on the receiving side. At this time, the sending side receives an RLC status report indicating that a data packet has been successfully transmitted at the RLC layer entity, which does not mean that the data packet has been successfully transmitted to the receiving side. Therefore, if the remote terminal switches its connection to another access network device, that is, when data packet transmission is performed after a path switch occurs, data packet loss during the transmission process may occur. Summary of the Invention

[0005] The embodiments of the present application provide a communication method and apparatus that can solve the problem of data packet loss when a terminal performs path switching in relay scenarios such as sidelink relay where data packets need to be transferred, thereby improving data transmission efficiency.

[0006] To achieve the above objectives, this application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a communication method, which can be applied to a remote terminal or a chip or processor in the remote terminal. Exemplarily, the method is described using a remote terminal as an example. The communication method includes: the remote terminal receives first indication information from a relay terminal; wherein the first indication information is used to indicate that the relay terminal has received first data, and the first data is data sent to a first access network device. The remote terminal receives second indication information; wherein the second indication information is used to indicate whether the first access network device has received the first data. The remote terminal determines second data based on the second indication information; the second data includes data in the first data that the first access network device has not received. The remote terminal sends the second data to the relay terminal or the second access network device.

[0008] Based on the communication method of the first aspect, the remote terminal sends an indication to the PDCP layer entity, indicating successful data transmission, only after confirming that the data has been successfully transmitted to the access network device. When the remote terminal switches from the first access network device to the second access network device, data that was not successfully transmitted to the access network device is resent by the remote terminal to the access network device. Data that was not successfully transmitted to the access network device is not missed, thus avoiding data loss. This enables lossless transmission of downlink data during terminal switching in relay scenarios, ensuring service continuity.

[0009] In one possible design, the remote terminal determines the second data based on the second indication information, including: the remote terminal determines the second data based on the first indication information and the second indication information. Based on this, the remote terminal can obtain information about whether the first access network device has received the first data based on the indication information fed back by the relay terminal. In one possible design, the method may also include: after the remote terminal switches from the first access network device to the second access network device, the remote terminal sends the second data to the relay terminal or the second access network device. Based on this, when the remote terminal undergoes path switching, the remote terminal can continue to interact with the second access network device and upload the data to the network side.

[0010] In one possible design, the method may further include: the second indication information comes from the relay terminal or the first access network device. Based on this, after receiving the second indication information from the relay terminal or the first access network device, the remote terminal can learn about the data reception status on the network side.

[0011] In one possible design, the method may further include: first indication information is included in a radio link control RLC control PDU; wherein the first indication information includes a first identifier of the first data and reception confirmation information of the first data; the reception confirmation information of the first data is used to indicate whether the relay terminal has successfully received each data in the first data; second indication information is included in a packet data convergence protocol PDCP control PDU; wherein the second indication information includes a second identifier of the first data; the second indication information is used to indicate whether the first access network device has successfully received each data in the first data. Based on this, the remote terminal can confirm whether the access network device has successfully received the first data by receiving the RLC control PDU, or the remote terminal can confirm whether the access network device has successfully received the first data through the relay function of the relay terminal.

[0012] In one possible design, the method may further include: the first identifier including the serial number of the first data; and the second identifier including the COUNT value or the serial number SN of the first data. Based on this, the remote terminal can quickly determine the first data based on the serial number, COUNT value, or the serial number SN of the first data.

[0013] In one possible design, the method may further include: the remote terminal receiving configuration information of a first function from the first access network device; wherein the first function is used by the remote terminal to determine third indication information based on the first indication information and / or the second indication information; wherein the third indication information is used to indicate data in the first data that has been successfully received by the first access network device. Based on this, the remote terminal can feedback the third indication information to the PDCP layer entity, so that the PDCP layer entity obtains an identifier of the data in the first data that has been successfully transmitted to the first access network device.

[0014] In one possible design, the method may further include: the remote terminal determining, based on the third indication information, the second data. Based on this, the remote terminal can determine the data in the first data that needs to be resent to the second access network device, determine the data as the second data, and then send it to the second access network device.

[0015] In a second aspect, a communication method is provided. The method can be applied to a first access network device or to a chip or processor in the first access network device. Exemplarily, the method is described using the first access network device as an example. The communication method includes: the first access network device receives first indication information from a relay terminal; wherein the first indication information is used to indicate that the relay terminal has received first data, where the first data is data sent to a remote terminal. The first access network device receives second indication information; wherein the second indication information is used to indicate whether the remote terminal has received the first data. The first access network device determines second data based on the second indication information; the second data includes data in the first data that the remote terminal has not received. The second access network device sends the second data to the relay terminal or the remote terminal.

[0016] Based on the communication method of the second aspect, the first access network device sends an indication to the PDCP layer entity, indicating successful data transmission, only after confirming that the data has been successfully transmitted to the remote terminal. When the remote terminal switches from the first access network device to the second access network device, data that was not successfully transmitted to the remote terminal will be resent by the second access network device to the remote terminal. Data that was not successfully transmitted to the remote terminal will not be missed, thus avoiding data loss. This enables lossless transmission of downlink data during terminal switching in relay scenarios, ensuring service continuity.

[0017] In one possible design, the first access network device determining the second data based on the second indication information includes: the first access network device determining the second data based on the first indication information and the second indication information. Based on this, the first access network device can determine whether the remote terminal has received the first data based on the indication information fed back by the relay terminal.

[0018] In one possible design, the method may further include: after the remote terminal switches from the first access network device to the second access network device, the second access network device sending second data to the relay terminal or the remote terminal. Based on this, after the remote terminal undergoes path switching, the remote terminal can continue to exchange data with the second access network device and upload the data to the network side.

[0019] In one possible design, the method may further include: the second indication information comes from the relay terminal or the remote terminal. Based on this, after receiving the second indication information from the relay terminal or the first access network device, the remote terminal can know the data reception status on the network side.

[0020] In one possible design, the method may further include: first indication information is included in an RLC control PDU; wherein the first indication information includes a first identifier of the first data and reception confirmation information of the first data; the reception confirmation information of the first data is used to indicate whether the relay terminal has successfully received the data corresponding to each count value or sequence number in the first data; second indication information is included in a PDCP control PDU; wherein the second indication information includes a second identifier of the first data. Based on this, the remote terminal can confirm whether the access network device has successfully received the first data by receiving the RLC control PDU, or the remote terminal can confirm whether the access network device has successfully received the first data through the relay function of the relay terminal.

[0021] In one possible design, the method may further include: the first identifier including the serial number of the first data; and the second identifier including the COUNT value or the serial number SN of the first data. Based on this, the first access network device can quickly determine the first data based on the serial number, COUNT value, or the serial number SN of the first data.

[0022] In one possible design, the method may further include: the first access network device sending configuration information for a second function to the relay terminal; wherein the second function is configured to cause the relay terminal to send second indication information to the first access network device. Based on this, the relay terminal can configure the second function to provide feedback to the first access network device regarding the transmission result of the first data between the relay terminal and the remote terminal.

[0023] In one possible design, the method may further include: the first access network device determining third indication information based on the first indication information and the second indication information; the third indication information being used to indicate data in the first data that has been successfully received by the first access network device. Based on this, the first access network device can feed back the third indication information to the PDCP layer entity, so that the PDCP layer entity obtains an identifier of the data in the first data that has been successfully transmitted to the first access network device.

[0024] In one possible design, the method may further include: the first access network device determining the second data based on the third indication information. Based on this, the first access network device can determine the data in the first data that needs to be re-sent to the remote terminal, determine the data as the second data, and then send it to the remote terminal.

[0025] In a third aspect, the present application provides a communication method that can be applied to a relay terminal or a chip or processor in a relay terminal. Exemplarily, the method is described using a relay terminal as an example. The communication method includes: the relay terminal sends first indication information to a remote terminal; wherein the first indication information is used to indicate that the relay terminal has received first data, where the first data is data sent to a first access network device. The relay terminal sends second indication information to the remote terminal; wherein the second indication information is used to indicate whether the first access network device has received the first data. The relay terminal sends second data to the second access network device; wherein the second data includes data in the first data that the first access network device has not received.

[0026] In one possible design, the method may further include: after the remote terminal switches from the first access network device to the second access network device, the relay terminal sends second data from the remote terminal to the second access network device.

[0027] In one possible design, the method may also include: the relay terminal sends second indication information to the remote terminal, specifically including: the relay terminal receives the second indication information from the first access network device; the relay terminal sends the second indication information from the first access network device to the remote terminal.

[0028] In one possible design, the method may also include: first indication information is included in the RLC control PDU; wherein the first indication information includes a first identifier of the first data and reception confirmation information of the first data; the reception confirmation information of the first data is used to indicate whether the relay terminal has successfully received each data in the first data; second indication information is included in the PDCP control PDU; wherein the second indication information includes a second identifier of the first data; the second indication information is used to indicate whether the first access network device has successfully received each data in the first data.

[0029] In a possible design, the method may further include: the first identifier includes the number of the first data; the second identifier includes the count COUNT value or serial number SN of the first data.

[0030] In one possible design, the method may further include: the relay terminal receives configuration information of a third function from the first access network device; wherein the third function is used by the relay terminal to send first indication information to the remote terminal.

[0031] In addition, the technical effects of the communication method of the third aspect can refer to the technical effects of the communication method of the first aspect, and will not be repeated here.

[0032] In a fourth aspect, the present application provides a communication method, which can be applied to a relay terminal or a chip or processor in a relay terminal. Exemplarily, the method is described using a relay terminal as an example. The communication method includes: the relay terminal sends first indication information to a first access network device; wherein the first indication information is used to indicate that the relay terminal has received first data, and the first data is data sent to a remote terminal. The relay terminal sends second indication information to the first access network device; wherein the second indication information is used to indicate whether the remote terminal has received the first data. The relay terminal sends second data to the remote terminal; wherein the second data includes data in the first data that the remote terminal has not received.

[0033] In one possible design, the method may further include: after the remote terminal switches from the first access network device to the second access network device, the relay terminal sends second data to the remote terminal.

[0034] In one possible design, the method may also include: the relay terminal sends second indication information to the first access network device, specifically including: the relay terminal receives the second indication information from the remote terminal; the relay terminal sends the second indication information from the remote terminal to the first access network device.

[0035] In one possible design, the method may also include: first indication information is included in the RLC control PDU; wherein the first indication information includes a first identifier of the first data and reception confirmation information of the first data; the reception confirmation information of the first data is used to indicate whether the relay terminal has successfully received each data in the first data; second indication information is included in the PDCP control PDU; wherein the second indication information includes a second identifier of the first data; the second indication information is used to indicate whether the first access network device has successfully received each data in the first data.

[0036] In a possible design, the method may further include: the first identifier includes the number of the first data; the second identifier includes the count COUNT value or serial number SN of the first data.

[0037] In one possible design, the method may further include: the relay terminal receives configuration information of a second function from the first access network device; wherein the second function is used by the relay terminal to send first indication information to the first access network device.

[0038] In addition, the technical effects of the communication method of the fourth aspect can refer to the technical effects of the communication method of the first aspect, and will not be repeated here.

[0039] In a fifth aspect, the present application provides a communication method that can be applied to a first access network device or a chip or processor in the first access network device. For example, the method is described using the first access network device as an example. The communication method includes: the first access network device sends second indication information to a remote terminal via a relay terminal; the second indication information indicates whether the first access network device has received first data, where the first data is data sent to the first access network device. The second access network device receives second data from the relay terminal or the remote terminal; the second data includes data in the first data that the first access network device did not receive.

[0040] In one possible design, the method may further include: after the remote terminal switches from the first access network device to the second access network device, the second access network device receives second data from the relay terminal or the remote terminal.

[0041] In one possible design, the method may further include: second indication information is included in the PDCP status report; wherein the second indication information includes a second identifier of the first data; and the second indication information is used to indicate whether the first access network device successfully receives each data in the first data.

[0042] In one possible design, the method may further include: the second identifier includes a count COUNT value or a serial number SN of the first data.

[0043] In one possible design, the method may also include: the first access network device sends configuration information of the first function to the remote terminal; wherein, the first function is used by the remote terminal to determine third indication information based on the first indication information and / or the second indication information; wherein, the third indication information is used to indicate the data in the first data that is successfully received by the first access network device.

[0044] In addition, the technical effects of the communication method of the fifth aspect can refer to the technical effects of the communication method of the first aspect, and will not be repeated here.

[0045] In a sixth aspect, the present application provides a communication method that can be applied to a remote terminal or a chip or processor in the remote terminal. For example, the method is described using a remote terminal as an example. The communication method includes: the remote terminal sends second indication information to a first access network device via a relay terminal; wherein the second indication information is used to indicate whether the remote terminal has received first data, where the first data is data sent to the remote terminal. The remote terminal receives second data sent by the relay terminal or the second access network device; wherein the second data includes data in the first data that the remote terminal did not receive.

[0046] In one possible design, the method may further include: after the remote terminal switches from the first access network device to the second access network device, the remote terminal receives second data sent from the relay terminal or the second access network device.

[0047] In one possible design, the method may further include: second indication information is included in the PDCP control PDU; wherein the second indication information includes a second identifier of the first data; and the second indication information is used to indicate whether the first access network device successfully receives each data in the first data.

[0048] In one possible design, the method may further include: the second identifier includes a count COUNT value or a serial number SN of the first data.

[0049] In addition, the technical effects of the communication method in the sixth aspect can refer to the technical effects of the communication method in the first aspect, and will not be repeated here.

[0050] In a seventh aspect, a communication device is provided. The communication device includes a receiving module, a processing module, and a sending module: the receiving module is used to receive first indication information from a relay terminal; wherein the first indication information is used to indicate that the relay terminal has received first data, and the first data is data sent to a first access network device. The receiving module is also used to receive second indication information; wherein the second indication information is used to indicate whether the first access network device has received the first data. The processing module is used to determine second data based on the second indication information; the second data includes data in the first data that the first access network device has not received. The sending module is used to send the second data to the relay terminal or the second access network device.

[0051] In one possible design, the processing module is further used to determine the second data based on the first indication information and the second indication information.

[0052] In one possible design, the second indication information comes from the relay terminal or the first access network device.

[0053] In one possible design, the first indication information is included in a radio link control (RLC) control protocol data unit (PDU); wherein the first indication information includes a first identifier of the first data and reception confirmation information of the first data; the reception confirmation information of the first data is used to indicate whether the relay terminal successfully receives each data item in the first data. The second indication information is included in a packet data convergence protocol (PDCP) control PDU; wherein the second indication information includes a second identifier of the first data; the second indication information is used to indicate whether the first access network device successfully receives each data item in the first data.

[0054] In a possible design, the first identifier includes the serial number of the first data; the second identifier includes the count COUNT value or serial number SN of the first data.

[0055] In one possible design, the receiving module is also used to receive configuration information of a first function from a first access network device; wherein the first function is used by the remote terminal to determine third indication information based on the first indication information and / or the second indication information; the third indication information is used to indicate the data in the first data that is successfully received by the first access network device.

[0056] In one possible design, the processing module is further used to determine the second data based on the third indication information.

[0057] In addition, the technical effects of the communication device described in the seventh aspect can refer to the technical effects of the communication method described in the first aspect, and will not be repeated here.

[0058] In an eighth aspect, a communication device is provided, comprising a receiving module, a processing module, and a sending module: the receiving module is configured to receive first indication information from a relay terminal, wherein the first indication information is configured to indicate that the relay terminal has received first data, the first data being data sent to a remote terminal. The receiving module is further configured to receive second indication information, wherein the second indication information is configured to indicate whether the remote terminal has received the first data. The processing module is configured to determine second data based on the second indication information, wherein the second data includes data in the first data that the remote terminal has not received. The sending module is configured to send the second data to the relay terminal or the remote terminal.

[0059] In one possible design, the processing module is further used to determine second data based on the first indication information and the second indication information; the second data includes data in the first data that is not received by the remote terminal.

[0060] In one possible design, the second indication information comes from the relay terminal or the remote terminal.

[0061] In one possible design, the first indication information is included in the RLC control PDU; wherein the first indication information includes a first identifier of the first data and reception confirmation information of the first data; the reception confirmation information of the first data is used to indicate whether the relay terminal has successfully received the data corresponding to each count value or sequence number in the first data; the second indication information is included in the PDCP control PDU; wherein the second indication information includes a second identifier of the first data.

[0062] In a possible design, the first identifier includes the serial number of the first data; the second identifier includes the count COUNT value or the serial number SN of the first data.

[0063] In one possible design, the sending module is also used to send configuration information of a second function to the relay terminal; wherein the second function is used by the relay terminal to send second indication information to the first access network device.

[0064] In one possible design, the processing module is also used to determine third indication information based on the first indication information and / or the second indication information; wherein the third indication information is used to indicate the data in the first data that is successfully received by the first access network device.

[0065] In one possible design, the processing module is further used to determine the second data based on the third indication information.

[0066] In addition, the technical effects of the communication device described in the eighth aspect can refer to the technical effects of the communication method described in the second aspect, and will not be repeated here.

[0067] In a ninth aspect, a communication device is provided. The communication device includes a sending module: the sending module is configured to send first indication information to a remote terminal; wherein the first indication information is configured to indicate that the relay terminal has received first data, the first data being data sent to a first access network device. The sending module is further configured to send second indication information to the remote terminal; wherein the second indication information is configured to indicate whether the first access network device has received the first data. The sending module is further configured to send second data to a second access network device; wherein the second data includes data in the first data that the first access network device has not received.

[0068] In one possible design, the communication device also includes a receiving module: the receiving module is used to receive second indication information from the first access network device.

[0069] The sending module is further configured to send second indication information from the first access network device to the remote terminal.

[0070] In one possible design, the first indication information is included in an RLC control PDU; the first indication information includes a first identifier of the first data and reception confirmation information of the first data; the reception confirmation information of the first data is used to indicate whether the relay terminal successfully receives each data item in the first data. The second indication information is included in a PDCP control PDU; the second indication information includes a second identifier of the first data; the second indication information is used to indicate whether the first access network device successfully receives each data item in the first data.

[0071] In a possible design, the first identifier includes the serial number of the first data; the second identifier includes the count COUNT value or the serial number SN of the first data.

[0072] In one possible design, the receiving module is further used to receive configuration information of a third function from the first access network device; wherein the third function is used by the relay terminal to send first indication information to the remote terminal.

[0073] In addition, the technical effects of the communication device described in the ninth aspect can refer to the technical effects of the communication method described in the first aspect, and will not be repeated here.

[0074] In a tenth aspect, a communication device is provided. The communication device includes a sending module: the sending module is configured to send first indication information to a first access network device; wherein the first indication information is configured to indicate that a relay terminal has received first data, the first data being data sent to a remote terminal. The sending module is further configured to send second indication information to the first access network device; wherein the second indication information is configured to indicate whether the remote terminal has received the first data. The sending module is further configured to send second data to the remote terminal; wherein the second data includes data in the first data that the remote terminal has not received.

[0075] In one possible design, the communication device also includes a receiving module: the receiving module is used to receive second indication information from the remote terminal.

[0076] The sending module is further configured to send second indication information from the remote terminal to the first access network device.

[0077] In one possible design, the first indication information is included in an RLC control PDU; the first indication information includes a first identifier of the first data and reception confirmation information of the first data; the reception confirmation information of the first data is used to indicate whether the relay terminal successfully receives each data item in the first data. The second indication information is included in a PDCP control PDU; the second indication information includes a second identifier of the first data; the second indication information is used to indicate whether the first access network device successfully receives each data item in the first data.

[0078] In a possible design, the first identifier includes the serial number of the first data; the second identifier includes the count COUNT value or the serial number SN of the first data.

[0079] In one possible design, the receiving module is also used to receive configuration information of a second function from the first access network device; wherein the second function is used by the relay terminal to send first indication information to the first access network device.

[0080] In addition, the technical effects of the communication device described in the tenth aspect can refer to the technical effects of the communication method described in the second aspect, and will not be repeated here.

[0081] In an eleventh aspect, a communication device is provided, comprising a sending module and a receiving module: the sending module is configured to send second indication information to a remote terminal; wherein the second indication information indicates whether a first access network device has received first data, the first data being data sent to the first access network device; and the receiving module is configured to receive second data from a relay terminal or a remote terminal; wherein the second data includes data in the first data that the first access network device has not received.

[0082] In one possible design, the second indication information is included in the PDCP control PDU; wherein the second indication information includes a second identifier of the first data; and the second indication information is used to indicate whether the first access network device successfully receives each data in the first data.

[0083] In one possible design, the second identifier includes a COUNT value or SN of the first data.

[0084] In one possible design, the sending module is also used to send configuration information of the first function to the remote terminal; wherein the first function is used by the remote terminal to determine third indication information based on the first indication information and / or the second indication information; the third indication information is used to indicate the data in the first data that is successfully received by the first access network device.

[0085] In addition, the technical effects of the communication device described in the eleventh aspect can refer to the technical effects of the communication method described in the first aspect, and will not be repeated here.

[0086] In a twelfth aspect, a communication device is provided, comprising a sending module and a receiving module: the sending module is configured to send second indication information to a first access network device; wherein the second indication information indicates whether a remote terminal has received first data, the first data being data sent to the remote terminal; and the receiving module is configured to receive second data sent by a relay terminal or a second access network device; wherein the second data includes data in the first data that the remote terminal has not received.

[0087] In one possible design, the second indication information is included in the PDCP control PDU; wherein the second indication information includes a second identifier of the first data; and the second indication information is used to indicate whether the first access network device successfully receives each data in the first data.

[0088] In one possible design, the second identifier includes a COUNT value or SN of the first data.

[0089] In addition, the technical effects of the communication device described in the twelfth aspect can refer to the technical effects of the communication method described in the second aspect, and will not be repeated here.

[0090] In a thirteenth aspect, a communication device is provided. The communication device includes: a processor coupled to a memory, the memory being configured to store a computer program; the processor being configured to execute the computer program stored in the memory, so that the communication device performs the communication method as described in any possible implementation of aspects 1 to 6.

[0091] In one possible design, the communication device described in the thirteenth aspect may further include a transceiver. The transceiver may be a transceiver circuit or an input / output port. The transceiver may be used for the communication device to communicate with other communication devices.

[0092] In the present application, the communication device described in the thirteenth aspect may be a terminal device or a network device, or a chip (system) or other parts or components arranged inside the terminal device or the network device.

[0093] In addition, the technical effects of the communication device described in the thirteenth aspect can refer to the technical effects of the communication method described in any one of the implementation methods in the first to sixth aspects, and will not be repeated here.

[0094] In a fourteenth aspect, a communication system is provided, which includes one or more terminal devices and one or more network devices.

[0095] In the fifteenth aspect, a computer-readable storage medium is provided, comprising: a computer program or instructions; when the computer program or instructions are run on a computer, the computer executes the communication method described in any possible implementation method of the first to sixth aspects.

[0096] In the sixteenth aspect, a computer program product is provided, comprising a computer program or instructions, which, when executed on a computer, enables the computer to execute the communication method described in any one of the possible implementations of the first to sixth aspects.

[0097] In the seventeenth aspect, a communication system is provided, which is used to execute the communication method described in any possible implementation method of the first to sixth aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0098] Figure 1 A schematic diagram of a V2X communication scenario provided in an embodiment of the present application;

[0099] Figure 2 A schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0100] Figure 3a A schematic diagram of a communication scenario provided in an embodiment of the present application;

[0101] Figure 3b A schematic diagram of another communication scenario provided in an embodiment of the present application;

[0102] Figure 3c A flow chart of a communication method provided in an embodiment of the present application;

[0103] Figure 3d A flowchart of another communication method provided in an embodiment of the present application;

[0104] Figure 4 A flowchart of another communication method provided in an embodiment of the present application;

[0105] Figure 5 A flowchart of another communication method provided in an embodiment of the present application;

[0106] Figure 6a A flowchart of another communication method provided in an embodiment of the present application;

[0107] Figure 6b A schematic diagram of the format of a second indication information provided in an embodiment of the present application;

[0108] Figure 6c A flowchart of another communication method provided in an embodiment of the present application;

[0109] Figure 7a A flowchart of another communication method provided in an embodiment of the present application;

[0110] Figure 7b A flowchart of another communication method provided in an embodiment of the present application;

[0111] Figure 8 A flowchart of another communication method provided in an embodiment of the present application;

[0112] Figure 9 A flowchart of another communication method provided in an embodiment of the present application;

[0113] Figure 10 A flowchart of another communication method provided in an embodiment of the present application;

[0114] Figure 11 A flowchart of another communication method provided in an embodiment of the present application;

[0115] Figure 12 A flowchart of another communication method provided in an embodiment of the present application;

[0116] Figure 13 A flowchart of another communication method provided in an embodiment of the present application;

[0117] Figure 14 A schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0118] Figure 15 A schematic structural diagram of another communication device provided in an embodiment of the present application;

[0119] Figure 16 A schematic structural diagram of another communication device provided in an embodiment of the present application;

[0120] Figure 17 A schematic diagram of the structure of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0121] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. In the present application, "at least one" refers to one or more, and "plurality" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can represent: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b and c can be single or multiple. In addition, to facilitate a clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, the words "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that the words "first" and "second" do not limit the quantity or execution order. For example, the "first" in the first terminal and the "second" in the second terminal in the embodiments of the present application are only used to distinguish different terminal devices.

[0122] It should be noted that, in this application, words such as "exemplarily" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplarily" or "for example" is intended to present the relevant concepts in a concrete manner.

[0123] The present invention provides a communication method for Figure 1 In the V2X communication scenario shown in Figure 1As shown, the first terminal and the second terminal communicate via a sidelink. The sidelink refers to the auxiliary link in the V2X network. In addition to the auxiliary link, the V2X network also has an uplink (UL) and a downlink (DL). Exemplarily, V2X communication includes vehicle-to-vehicle (V2V) communication, vehicle-to-roadside infrastructure (V2I) communication, vehicle-to-people (V2P) communication, and vehicle-to-application server (V2N) communication. Figure 1 In the example, only the V2V communication in which the first terminal and the second terminal are both vehicles is used for illustration. The embodiment of the present application does not limit the specific communication scenario of V2X. For example, the first terminal and the second terminal can be the communication between vehicle-mounted devices and vehicle-mounted devices, or the communication between the road side unit (RSU) and the vehicle-mounted device and / or the network device (such as the base station device), or the communication between the network device (such as the base station device) and the vehicle-mounted device and / or the RSU, etc. The network device (can be an LTE base station device or an NR base station device or a base station in a subsequent evolution system. It can be understood that the embodiment of the present application does not limit the specific form of the first terminal and the second terminal, and this is only an exemplary explanation. For example, Figure 1 The access network device in the network may be a base station, or a device in a network that provides wireless access.

[0124] Figure 1 The illustrated V2X communication architecture includes two communication interfaces: the PC5 interface and the Uu interface. The V2X PC5 interface is a direct communication interface between V2X terminals. V2X Uu interface communication is a communication method in which a transmitting V2X terminal (e.g., a second terminal) sends V2X data via the Uu interface to an access network device (e.g., a base station). The data is then sent to a V2X application server via the access network device for processing. The V2X application server then sends the data to the access network device, which then sends the data to a receiving V2X terminal (e.g., a first terminal) via the access network device. In the V2X Uu interface communication method, the access network device that forwards uplink data from the terminal to the server and the access network device that forwards downlink data from the server to the receiving terminal can be the same access network device or different access network devices, depending on the V2X application server.

[0125] Figure 2A communication device provided in an embodiment of the present application may be the first terminal or the second terminal in the present application. The communication device may be a vehicle; or it may be an on-board communication device or a on-board terminal installed on a vehicle to assist the vehicle in driving, or a chip in the on-board communication device or the on-board terminal. The on-board terminal may be a device for implementing wireless communication functions, such as a terminal or a chip that can be used in a terminal. The terminal may be a user equipment (UE), an access terminal, a terminal unit, a terminal station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a wireless communication device, a terminal agent or a terminal device in a 5G network or a future evolved public land mobile network (PLMN). The access terminal may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication capabilities, a computing device or other processing device connected to a wireless modem, an in-vehicle device or a wearable device, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical care, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc. The in-vehicle terminal may be mobile or fixed.

[0126] like Figure 2 As shown, the communication device 200 includes at least one processor 201 , a memory 202 , a transceiver 203 and a communication bus 204 .

[0127] The following combination Figure 2 The following is a detailed introduction to the various components of the communication equipment:

[0128] Processor 201 is the control center of the communication device and can be a single processor or a collective term for multiple processing elements. For example, processor 201 can be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention, such as one or more microprocessors (digital signal processors, DSPs) or one or more field programmable gate arrays (FPGAs).

[0129] The processor 201 may execute various functions of the communication device by running or executing software programs stored in the memory 202 and calling data stored in the memory 202 .

[0130] In a specific implementation, as an embodiment, the processor 201 may include one or more CPUs, such as Figure 2 CPU0 and CPU1 are shown in the figure.

[0131] In a specific implementation, as an embodiment, the communication device may include multiple processors, such as Figure 2 201 and processor 205 are shown in FIG. Each of these processors can be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). A processor herein can refer to one or more communication devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0132] The memory 202 may be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other type of dynamic storage device 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, an optical disc storage (including a compact 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 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 202 may exist independently and be connected to the processor 201 via the communication bus 204. The memory 202 may also be integrated with the processor 201.

[0133] The memory 202 is used to store the software program for executing the solution of the present invention, and the execution is controlled by the processor 201.

[0134] Transceiver 203 is used to communicate with other communication devices. Of course, transceiver 203 can also be used to communicate with communication networks, such as Ethernet, radio access networks (RAN), wireless local area networks (WLAN), etc. Transceiver 203 can include a receiving unit to implement a receiving function and a sending unit to implement a sending function.

[0135] The communication bus 204 can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. This bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 2 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0136] Figure 2The communication device structure shown in does not constitute a limitation of the communication device, and may include more or fewer components than shown in the figure, or a combination of certain components, or a different arrangement of components. In scenarios where the terminal communicates with the network, or the terminal communicates with the terminal, for service data with very high reliability requirements, an acknowledgement mode (AM) data radio bearer (DRB) is usually configured on the air interface side or the sidelink interface side for data transmission. The AM DRB is a DRB configured with an AM radio link control RLC layer entity, which can ensure the reliability of data packet transmission through the automatic repeat request (ARQ) mechanism of the RLC layer entity, and also needs to ensure lossless transmission of data when the terminal makes a switch.

[0137] In the scenario where the terminal and the network communicate, such as Figure 3a As shown, after being transferred through the relay node, remote terminals located at the edge of the cell coverage or outside the cell can realize data transmission with the access network equipment, thereby enhancing the network coverage capability. When the terminal and the network communicate, there is a remote terminal and one or more relay terminals (i.e., relay nodes), wherein the remote terminal and the access network equipment can transmit data and signaling through the relay node. At present, there are two ways to implement communication between the terminal and the network: a relay method based on Layer 3 (L3, Layer 3) and a relay method based on Layer 2 (L2, Layer 2). In the relay method based on L3, user data is relayed and forwarded at the IP layer; while in the relay method based on L2, user data is relayed and forwarded below the PDCP layer entity.

[0138] In the scenario where terminals communicate with each other, such as Figure 3b As shown, after the relay is performed through the relay node, the problem that the communication distance is not very far due to insufficient hardware capabilities of the sending side terminal and the like, resulting in limited scenarios for terminal-to-terminal communication through sidelink can be solved. At present, there are two ways to implement communication between terminals: a relay method based on L3 and a relay method based on L2. In the prior art, for AM DRB, in the process of the terminal switching from the first access network device to the second access network device, the first access network device transmits the uplink / downlink PDCP sequence number SN and hyper frame number (HFN) status to the target station through the SN status transfer information, and transmits the uplink / downlink PDCP service data unit (SDU) to the target station through the data forwarding process.

[0139] Specifically, the existing technology is introduced in two cases: uplink and downlink:

[0140] Case 1: Downlink transmission, including the following steps:

[0141] S3011. The first access network device indicates to the second access network device in the SN status transfer information the COUNT value that needs to be allocated to the next downlink PDCP SDU that has not yet been allocated a COUNT value in an AM DRB.

[0142] The COUNT value and SN are both used to indicate the sequence number of the PDCP SDU. The COUNT value is 32 bits long, the SN is the lower 12 / 18 bits of the COUNT, and the HFN is the upper 20 / 14 bits.

[0143] In this application, the COUNT value and SN can be used as identifiers of data packets in the PDCP layer entity.

[0144] S3012. During the data forwarding process, the first access network device first sequentially forwards all PDCP SDUs and corresponding SNs for which the terminal has not received confirmation feedback to the second access network device, and then forwards the PDCP SDUs received from the user plane function (UPF) to the second access network device.

[0145] Terminal confirmation feedback refers to feedback indicated by the RLC layer entity of the terminal confirming successful data reception, and is included in the RLC status report sent by the terminal.

[0146] S3013. The second access network device first sends the PDCP SDU with SN forwarded by the first access network device to the terminal, and then sends the PDCP SDU without SN forwarded by the first access network device to the terminal; if the second access network device receives the PDCP status report sent by the terminal, the second access network device does not need to send the PDCP status report to the terminal to confirm that it has received the PDCP SDU.

[0147] S3014: After receiving the PDCP SDU from the second access network device, the terminal reorders the received PDCP SDU and submits it to the upper layer.

[0148] Case 2: Uplink transmission, including the following steps:

[0149] S3021. The first access network device indicates to the second access network device in the SN status transfer information the COUNT value (FMC, first missing COUNT) corresponding to the first PDCP SDU that was not received, and a bit sequence indicating the PDCP SDU reception status of the first access network device, where the Nth bit of the bit sequence represents the reception status of the Nth PDCP SDU after the above-mentioned first PDCP SDU that was not received. A value of 1 indicates successful reception, and a value of 0 indicates failure to receive.

[0150] The second access network device may use this part of the information in the SN status transfer information to generate a PDCP status report and send it to the terminal.

[0151] S3022. The first access network device forwards the PDCP SDU and the corresponding SN received out of sequence to the second access network device during the data forwarding process.

[0152] S3023. The terminal retransmits or transmits the PDCP SDUs to the second access network device in ascending order of COUNT values, starting with the first PDCP SDU for which no acknowledgment feedback was received from the first access network device. If the terminal receives a PDCP status report from the second access network device, the terminal does not need to send the PDCP SDU indicated in the PDCP status report as successfully received to the second access network device. Acknowledgment feedback from the first access network device refers to feedback indicating successful data reception by the RLC layer entity of the first access network device.

[0153] In the prior art, AM DRB uses the ARQ mechanism to ensure data transmission reliability. After the AM RLC layer entity receives a data packet (PDCP PDU) from the PDCP layer entity and transmits it, it stores the data packet in the RLC layer entity's buffer. Upon receiving an RLC status report from the peer AM RLC layer entity, if the RLC status report indicates that the data packet was not received, the AM RLC layer entity retransmits the data packet. If the RLC status report confirms that the data packet has been received, the AM RLC layer entity does not need to retransmit the data packet, and the RLC layer entity sends an indication to the PDCP layer entity indicating that the data packet has been successfully transmitted.

[0154] Specifically, in a scenario where the terminal and the access network device communicate directly, if the terminal receives an RLC status report indicating that a data packet has been successfully transmitted at the RLC layer entity, then the data packet must have been successfully transmitted to the access network device. However, in relay scenarios such as sidelink relay scenarios where data packets need to be transferred, a data packet sent by the PDCP layer entity on the sending side needs to be transmitted over two hops before it reaches the PDCP layer entity on the receiving side. At this time, the sending side receives an RLC status report indicating that a data packet has been successfully transmitted at the RLC layer entity, which does not mean that the data packet has been successfully transmitted to the receiving side. Therefore, when a path switch occurs at the terminal, data packets that have not been successfully transmitted to the receiving side may be lost.

[0155] like Figure 3c As shown, when uplink data transmission is performed, the remote terminal sends data packets #100-#103 at the RLC layer, and receives an RLC status report fed back by the relay terminal, indicating that #100-#102 are successfully received, but #103 is not received. At this time, the relay terminal transfers the data packets to the first access network device, and only the data packet corresponding to #100 is successfully transmitted to the first access network device. At this time, the remote terminal switches, the PDCP layer entity will re-establish, and start from the PDCP SDU corresponding to #103 (that is, the first PDCP SDU that has not received confirmation feedback from the first access network device) to retransmit or transmit the PDCP SDU in ascending order of COUNT. If the transmission channel between the relay terminal and the access network device also deteriorates at this time, the PDCP SDU corresponding to #101 and #102 may be lost, and the remote terminal will not retransmit the PDCP SDU corresponding to #101 and #102.

[0156] like Figure 3d As shown, during downlink data transmission, when the remote terminal switches, the first access network device forwards the PDCP SDU starting from the PDCP SDU corresponding to #103 to the second access network device; but if the link between the remote terminal and the relay terminal is disconnected at this time, the PDCP SDU corresponding to #101 and #102 may be lost.

[0157] To solve the problem of data packet loss when a terminal performs path switching in relay scenarios such as sidelink relay scenarios, an embodiment of the present application provides a communication method that can ensure that data packets are successfully received by a receiving end when a terminal performs path switching, thereby improving data transmission efficiency.

[0158] Combine Figure 1-Figure 3d ,like Figure 4As shown, a communication method provided in an embodiment of the present application includes steps S401-S408 and can be applied to uplink data transmission.

[0159] S401. A remote terminal sends first data to a first access network device through a relay terminal.

[0160] The first data may include multiple data packets. Further, the first data may include multiple data packets sent simultaneously or multiple data packets sent successively.

[0161] Optionally, the first data has a first identifier, which may include a serial number of the first data.

[0162] It is understandable that each data packet in the first data has a corresponding number. For example, the first data includes four data packets, and the corresponding numbers of these data packets are #100, #101, #102, and #103.

[0163] S402: The relay terminal sends first indication information to the remote terminal.

[0164] The first indication information is used to indicate the reception status of the data packets in the first data by the relay terminal. Exemplarily, the first indication information indicates whether each data packet in the first data has been received successfully.

[0165] Optionally, the first indication information includes a first identifier of the first data.

[0166] Optionally, the first indication information is included in an RLC control PDU. Exemplarily, the RLC control PDU may be an RLC status report, and the subsequent steps S403-408 are described by taking the first indication information included in the RLC status report as an example.

[0167] S403: The first access network device sends an RLC status report to the relay terminal.

[0168] S404: The relay terminal sends second indication information to the remote terminal.

[0169] The second indication information may include numbers of some or all of the data packets in the first data. The second indication information may be called a Relay ACK Indication message, which is used to indicate whether the first access network device has successfully received the data packets in the first data.

[0170] S405. The RLC layer entity of the remote terminal sends third indication information to the PDCP layer entity.

[0171] The third indication information is used by the RLC layer entity of the remote terminal to indicate to the PDCP layer entity the successful transmission of the data packet in the first data that has been successfully transmitted to the first access network device.

[0172] Optionally, the remote terminal determines the third indication information based on the first indication information and / or the second indication information.

[0173] S406: The remote terminal determines the second data.

[0174] Optionally, the remote terminal determines the second data based on the third indication information.

[0175] The second data includes data packets in the first data that are not successfully received by the first access network device.

[0176] Optionally, the second data includes the first data packet in the first data that is not successfully received by the first access network device, and subsequent data packets with consecutive numbers.

[0177] S407: The remote terminal performs path switching from the first access network device to the second access network device.

[0178] S408. The remote terminal sends second data to the second access network device.

[0179] Optionally, the remote terminal sends the second data to the second access network device through the relay terminal.

[0180] It is understood that if, after path switching, the remote terminal is directly connected to the second access network device and directly transmits data with the second access network device, the remote terminal directly sends the second data to the second access network device without further transmission through the relay terminal. For example, after the remote terminal accesses the second access network device through a random access process, it sends the second data to the second access network device.

[0181] Optionally, in step S407, the first access network device may instruct the remote terminal to re-establish the PDCP layer entity; at this time, in step S408, the remote terminal sends the second data to the first access network device.

[0182] It should be noted that, for data successfully sent to the first access network device before the remote terminal performs path switching, the first access network device can forward the data that has not been delivered to the core network to the second access network device after the remote terminal performs path switching.

[0183] Based on the above technical solution, the remote terminal sends an indication to the PDCP layer entity, indicating successful data transmission, only after confirming that the data has been successfully transmitted to the access network device. When the remote terminal switches from the first access network device to the second, any data that was not successfully transmitted to the access network device is resent by the remote terminal to the access network device. This prevents data loss and eliminates the risk of missed transmissions. This enables lossless transmission of downlink data during terminal handover in relay scenarios, ensuring service continuity.

[0184] Combine Figure 1-Figure 3d ,like Figure 5 As shown, a communication method provided in an embodiment of the present application includes steps S501-S509 and can be applied to downlink data transmission.

[0185] S501. A first access network device sends first data to a remote terminal through a relay terminal.

[0186] The first data may include multiple data packets. Further, the first data may include multiple data packets sent simultaneously or multiple data packets sent successively.

[0187] Optionally, the first data has a first identifier, which may include a serial number of the first data.

[0188] It is understandable that each data packet in the first data has a corresponding number. For example, the first data includes four data packets, and the corresponding numbers of these data packets are #100, #101, #102, and #103.

[0189] S502. The relay terminal sends first indication information to the first access network device.

[0190] The first indication information is used to indicate the reception status of the data packets in the first data by the relay terminal. Exemplarily, the first indication information indicates whether each data packet in the first data has been received successfully.

[0191] Optionally, the first indication information includes a first identifier of the first data.

[0192] Optionally, the first indication information is included in an RLC control PDU. Exemplarily, the RLC control PDU may be an RLC status report, and the subsequent steps S503-S509 are described by taking the first indication information included in the RLC status report as an example.

[0193] S503: The remote terminal sends an RLC status report to the relay terminal.

[0194] S504. The relay terminal sends second indication information to the first access network device.

[0195] The second indication information includes the serial numbers of some or all of the data packets in the first data. The second indication information may be called a Relay ACK Indication message, which is used to indicate whether the remote terminal has successfully received the data packets in the first data.

[0196] S505. The RLC layer entity of the first access network device sends third indication information to the PDCP layer entity.

[0197] The third indication information is used by the RLC layer entity of the remote terminal to indicate to the PDCP layer entity the successful transmission of the data packet in the first data that has been successfully transmitted to the remote terminal.

[0198] Optionally, the first access network device determines the third indication information based on the first indication information and / or the second indication information.

[0199] S506: The first access network device confirms the second data.

[0200] Optionally, the first access network device determines the second data based on the third indication information.

[0201] The second data includes data packets in the first data that are not successfully received by the remote terminal.

[0202] S507: The remote terminal switches from the first access network device to the second access network device.

[0203] S508: The first access network device forwards the second data to the second access network device.

[0204] S509: The second access network device sends second data to the remote terminal.

[0205] Optionally, the second access network device sends the second data to the remote terminal through the relay terminal.

[0206] It is understood that if the remote terminal is directly connected to the second access network device after the path switch, the second access network device can directly transmit data with the remote terminal to send the second data, without having to send it through the relay terminal. Exemplarily, after the remote terminal accesses the second access network device through a random access process, the second access network device sends the second data to the remote terminal.

[0207] Optionally, in step S507, the first access network device may instruct the remote terminal to re-establish the PDCP layer entity. In this case, in steps S508-S509, the remote terminal sends the second data to the first access network device.

[0208] Based on the above technical solution, the first access network device sends an indication to the PDCP layer entity, indicating successful data transmission, only after confirming that the data has been successfully transmitted to the remote terminal. When the remote terminal switches from the first access network device to the second access network device, data that was not successfully transmitted to the remote terminal will be resent by the second access network device to the remote terminal. Data that was not successfully transmitted to the remote terminal will not be missed, thus avoiding data loss. This enables lossless transmission of downlink data during terminal switching in relay scenarios, ensuring service continuity.

[0209] For example, the present invention also provides a communication method. Figure 6a As shown, the method includes steps S601-S610 and can be applied to uplink data transmission in relay scenarios such as sidelink relay scenarios.

[0210] S601. A first access network device sends configuration information of a first function to a remote terminal through a relay terminal.

[0211] The first function is for the RLC layer of the remote terminal to send indication information indicating successful data transmission to the PDCP layer according to the received second indication information. The configuration information of the first function can be carried in an information element of the RRC reconfiguration message, exemplarily carried in an RLC configuration information element.

[0212] It should be noted that after the remote terminal configures the first function, after the RLC layer entity of the remote terminal receives the RLC control PDU fed back by the relay terminal, it does not send data transmission success indication information to the PDCP layer for the RLC SDUs indicated as having been successfully transmitted. Only after the remote terminal also receives the second indication information sent by the relay terminal will the RLC layer entity of the remote terminal send data transmission success indication information corresponding to the RLC SDUs that have been successfully delivered to the first access network device to the PDCP layer based on the information in the message indicating that the RLC SDUs have been successfully delivered to the first access network device.

[0213] S602: The first access network device sends configuration information of the second function to the relay terminal.

[0214] The second function is used for the relay terminal to send second indication information to the remote terminal. The second indication information is used for the remote terminal to obtain the result of the first access network device receiving the first data.

[0215] It should be noted that after the relay terminal is configured with the second function, after receiving the RLC status report from the first access network device, the relay terminal triggers the sending of second indication information to the remote terminal. Furthermore, the relay terminal indicates in the second indication information, based on the RLC control PDU fed back by the first access network device, information about the RLC SDU that has been successfully delivered to the first access network device. The second indication information is used to indicate whether the first access network device successfully received some or all of the data packets in the first data.

[0216] Optionally, after receiving the RLC control PDU from the first access network device, the relay terminal triggers sending the second indication information to the remote terminal.

[0217] Optionally, the first access network device configures a second function for the relay terminal, which can configure the relay terminal to send a second indication message only to one or part of the remote terminals, for indicating the first access network device to receive a confirmation result of the first data sent by the corresponding remote terminal. Exemplarily, the identification information of the remote terminal can be carried in the configuration information of the second function. For example, the relay terminal is connected to remote terminal A and remote terminal B, and the first access network device can configure the relay terminal to send a second indication message to remote terminal A. Then, when the relay terminal receives the RLC control PDU fed back by the first access network device, which indicates that some of the data packets sent by remote terminal A and remote terminal B have been successfully delivered to the first access network device, the relay terminal only sends the second indication message to remote terminal A.

[0218] Optionally, in steps S601-S602, the RLC control PDU may be an RLC status report.

[0219] S603: The remote terminal sends first data to the first access network device through the relay terminal.

[0220] The first data may include multiple data packets. Further, the first data may include multiple data packets sent simultaneously or multiple data packets sent successively.

[0221] Optionally, the first data has a first identifier, which may include a serial number of the first data.

[0222] It is understood that each data packet in the first data has a corresponding number, which is the number corresponding to the data packet at the RLC layer. For example, the first data includes four data packets, and the corresponding numbers of these data packets are #100, #101, #102, and #103.

[0223] S604: After receiving the first data, the relay terminal sends first indication information to the remote terminal.

[0224] The first indication information is used to indicate the reception status of the data packets in the first data by the relay terminal. Exemplarily, the first indication information indicates whether each data packet in the first data has been received successfully.

[0225] Optionally, the first indication information includes a first identifier of the first data.

[0226] Optionally, the first indication information is included in an RLC control PDU. Exemplarily, the RLC control PDU may be an RLC status report, and the subsequent steps S605-S610 are described by taking the first indication information included in the RLC status report as an example.

[0227] S605: The first access network device sends an RLC status report to the relay terminal.

[0228] S606. After receiving the RLC status report from the first access network device, the relay terminal sends second indication information to the remote terminal.

[0229] The second indication information is used to indicate whether the first access network device has successfully received the data packet in the first data.

[0230] by Figure 6b For example, the second indication information may be an RLC control PDU, and the second indication information may be identified by the control protocol data unit type (CPT) field. Exemplarily, the second indication information may be called a relay acknowledgment indication message. Exemplarily, the message includes an indication field (such as FFSN, first failed SN) to identify the SN of the first RLC SDU that has not yet been delivered to the first access network device. RLC SDUs with SNs less than FFSN may be considered to have been successfully delivered to the first access network device. Optionally, the message also includes a bitmap for identifying the delivery status of the RLC SDU after the FFSN, wherein the nth bit after the FFSN identifies the delivery status of the RLC SDU corresponding to SN=FFSN+n. If the value of the bit is 0, it indicates that it has not yet been delivered to the first access network device; otherwise, it indicates that it has been delivered to the first access network device.

[0231] It is understandable that, when the relay terminal is configured with the second function, it can generate the second indication information and send it to the remote terminal.

[0232] S607: The remote terminal determines third indication information according to the first indication information and the second indication information.

[0233] The third indication information is used by the RLC layer entity of the remote terminal to indicate to the PDCP layer entity the successful transmission of the data packet in the first data that has been successfully transmitted to the first access network device.

[0234] Optionally, when the remote terminal is configured with the first function, it can determine the third indication information based on the first indication information and the second indication information, or based on the second indication information, and the RLC layer entity can indicate the third indication information to the PDCP layer entity.

[0235] Optionally, the remote terminal determines the third indication information based on the number corresponding to the data packet successfully received by the relay terminal in the first indication information and the number corresponding to the data packet successfully received by the first access network device in the second indication information.

[0236] For example, the numbers corresponding to the data packets successfully received by the relay terminal in the first indication information are #100, #101, and #103, and the number corresponding to the data packet successfully received by the first access network device in the second indication information is #100. The remote terminal determines that the data packet numbered #100 is successfully received by the first access network device, and the RLC layer entity indicates to the PDCP layer entity through the third indication information that the PDCP SDU corresponding to the #100 data packet has been successfully transmitted.

[0237] S608. The remote terminal determines the second data according to the third indication information.

[0238] The second data includes data packets in the first data that are not successfully received by the first access network device.

[0239] Optionally, the second data includes the first data packet in the first data that is not successfully received by the first access network device, and subsequent data packets with consecutive numbers.

[0240] Optionally, the remote terminal determines the second data based on the number corresponding to the data successfully received by the first access network device in the third indication information and the number corresponding to each data included in the first data.

[0241] It is understood that if the numbers corresponding to a portion of the first data are not included in the numbers corresponding to the data successfully received by the first access network device in the third indication information, it indicates that the data corresponding to this portion of the numbers was not successfully transmitted to the first access network device. The data corresponding to this portion of the numbers is the second data.

[0242] Exemplarily, the number corresponding to the data packet successfully received by the first access network device in the third indication information is #100, and the numbers corresponding to the data packets contained in the first data are #100, #101, #102, and #103. The remote terminal then determines the data packets numbered #101, #102, and #103 in the first data as the second data.

[0243] S609: The remote terminal switches from the first access network device to the second access network device.

[0244] Optionally, after the remote terminal switches from the first access network device to the second access network device, it can connect to the second access network device through a relay terminal to transmit data, or directly connect to the second access network device to transmit data.

[0245] It is understood that if, after path switching, the remote terminal is directly connected to the second access network device and directly transmits data with the second access network device, the remote terminal directly sends the second data to the second access network device without further transmission through the relay terminal. For example, after the remote terminal accesses the second access network device through a random access process, it sends the second data to the second access network device.

[0246] S610: The remote terminal sends second data to the second access network device.

[0247] Optionally, the remote terminal sends the second data to the second access network device through the relay terminal; or, the remote terminal sends the second data directly to the second access network device.

[0248] It is understandable that, for data successfully transmitted to the first access network device before the remote terminal switches from the first access network device to the second access network device, the first access network device can forward the data packets that are not delivered to the core network to the second access network device.

[0249] Optionally, in step S609, the first access network device may instruct the remote terminal to re-establish the PDCP layer entity. In this case, in step S610, the remote terminal sends the second data to the first access network device.

[0250] Optionally, in steps S601 and S610, there may be multiple relay terminals. Figure 6c As shown, the remote terminal sends uplink data to the first access network device through relay terminal A and relay terminal B. At this time, in step S602, the first access network device sends configuration information of the second function to relay terminal A and relay terminal B respectively, configuring the second function A for relay terminal A and configuring the second function B for relay terminal B.

[0251] It is understood that after relay terminal A is configured with the second function A, upon receiving the second indication information B sent by relay terminal B, it triggers the sending of the second indication information A to the remote terminal, so that the remote terminal obtains the result of the first access network device receiving the first data. The second indication information A is used to enable the remote terminal to obtain the result of the first access network device receiving the first data, and the second indication information B is used to enable relay terminal A to obtain the result of the first access network device receiving the first data.

[0252] Based on the above technical solution, before the remote terminal performs uplink data transmission, the first access network device will configure the first function for the remote terminal and the second function for the relay terminal, so that after the remote terminal confirms that the data has been successfully transmitted to the access network device, the RLC layer entity of the remote terminal will send an indication message to the PDCP layer entity, indicating that the data transmission is successful, and the remote terminal can also be informed of the data that has not been successfully transmitted to the access network device. When the remote terminal undergoes path switching, the data that has not been successfully transmitted to the access network device will be re-sent by the remote terminal to the access network device, and the data that has not been successfully transmitted to the access network device will not be missed, thereby avoiding data loss. This achieves lossless transmission of data when the terminal switches in the relay scenario, ensuring business continuity.

[0253] For example, the present invention also provides a communication method. Figure 7a As shown, the method includes steps S701-S710 and can be applied to downlink data transmission in a relay scenario.

[0254] S701. A first access network device sends configuration information of a second function to a relay terminal.

[0255] The second function is used for the relay terminal to send a second indication message to the first access network device. The second indication message is used to enable the first access network device to obtain the result of the remote terminal receiving the first data. It should be noted that, corresponding to the uplink data transmission, after the relay terminal is configured with the second function, after the RLC layer entity of the relay terminal receives the RLC control PDU from the remote terminal, it triggers the sending of the second indication message to the first access network device, and the relay terminal indicates the information of the RLC SDU that has been successfully delivered to the first access network device in the RLC status report fed back by the first access network device. The second information is used to indicate whether the remote terminal has successfully received some or all of the data packets in the first data.

[0256] Optionally, after receiving the RLC control PDU from the remote terminal, the RLC layer entity of the relay terminal triggers sending the second indication information to the first access network device.

[0257] Optionally, the first access network device configures a second function for the relay terminal, enabling the relay terminal to trigger the sending of the second indication information to the first access network device only in response to RLC control PDUs fed back by one or more remote terminals. Exemplarily, the configuration information for the second function may include identification information of the remote terminals. For example, if the relay terminal is connected to remote terminal A and remote terminal B, the first access network device may configure the relay terminal to trigger the sending of the second indication information to the first access network device only upon receipt of an RLC control PDU from remote terminal A.

[0258] Optionally, in step S701, the RLC control PDU may be an RLC status report.

[0259] S702: The first access network device sends first data to the remote terminal through the relay terminal.

[0260] The first data may include multiple data packets. Further, the first data may include multiple data packets sent simultaneously or multiple data packets sent successively.

[0261] Optionally, the first data has a first identifier, which may include a serial number of the first data.

[0262] It is understandable that each data packet in the first data has a corresponding number. For example, the first data includes four data packets, and the corresponding numbers of these data packets are #100, #101, #102, and #103.

[0263] S703. After receiving the first data, the relay terminal sends first indication information to the first access network device.

[0264] The first indication information is used to indicate the reception status of the data packets in the first data by the relay terminal. Exemplarily, the first indication information indicates whether each data packet in the first data has been received successfully.

[0265] Optionally, the first indication information includes a first identifier of the first data.

[0266] Optionally, the first indication information is included in an RLC control PDU. Exemplarily, the RLC control PDU may be an RLC status report, and the subsequent steps S704-S710 are described by taking the first indication information included in the RLC status report as an example.

[0267] S704: The remote terminal sends an RLC status report to the relay terminal.

[0268] S705: After receiving the RLC status report from the remote terminal, the relay terminal sends second indication information to the first access network device.

[0269] The second indication information is used to indicate whether the remote terminal has successfully received part or all of the data packets in the first data.

[0270] S706. The first access network device determines third indication information according to the first indication information and the second indication information.

[0271] The third indication information is used by the RLC layer entity of the first access network device to indicate to the PDCP layer entity the successful transmission of the data packet in the first data that has been successfully transmitted to the remote terminal.

[0272] Optionally, the first access network device determines the third indication information based on the number corresponding to the data packet successfully received by the relay terminal in the first indication information and the number corresponding to the data packet successfully received by the remote terminal in the second indication information.

[0273] Exemplarily, the numbers corresponding to the data packets successfully received by the relay terminal in the first indication information are #100, #101, and #103, and the number corresponding to the data packet successfully received by the remote terminal in the second indication information is #100. The first access network device determines that the data packet numbered #100 is successfully received by the remote terminal, and generates a third indication information corresponding to the data packet.

[0274] S707. The first access network device determines the second data according to the third indication information.

[0275] Optionally, the first access network device determines the second data based on the number corresponding to the data packet successfully received by the remote terminal in the third indication information and the number corresponding to each data packet included in the first data.

[0276] It is understood that if the numbers corresponding to a portion of the first data are not included in the numbers corresponding to the data successfully received by the remote terminal in the third indication information, it indicates that the data corresponding to this portion of the numbers was not successfully transmitted to the remote terminal. The data corresponding to this portion of the numbers is the second data.

[0277] Exemplarily, the number corresponding to the data packet successfully received by the remote terminal in the third indication information is #100, and the numbers corresponding to the data packets contained in the first data are #100, #101, #102, and #103. Then the first access network device determines the data packets numbered #101, #102, and #103 in the first data as the second data.

[0278] S708. The remote terminal switches from the first access network device to the second access network device.

[0279] Optionally, after the remote terminal switches from the first access network device to the second access network device, it can connect to the second access network device through a relay terminal to transmit data, or directly connect to the second access network device to transmit data.

[0280] It can be understood that if the remote terminal is still not within the coverage of the second access network device after switching from the first access network device to the second access network device, the remote terminal connects to the second access network device through the relay terminal to transmit data; if the remote terminal is within the coverage of the second access network device after switching from the first access network device to the second access network device, the remote terminal directly connects to the second access network device to transmit data; at this time, after the remote terminal accesses the second access network device through the random access process, the second access network device sends the second data to the remote terminal.

[0281] S709: The first access network device sends second data to the second access network device.

[0282] S710. The second access network device sends second data to the remote terminal.

[0283] Optionally, the second access network device sends the second data to the remote terminal through the relay terminal; or, the second access network device sends the second data directly to the remote terminal.

[0284] Optionally, in step S708, the first access network device may instruct the remote terminal to re-establish the PDCP layer entity. In this case, in steps S709-S710, the first access network device sends the second data to the remote terminal.

[0285] Optionally, in steps S701 and S710, there may be multiple relay terminals. Figure 7b As shown, the first access network device sends downlink data to the remote terminal through relay terminal A and relay terminal B. At this time, in step S701, the first access network device sends configuration information of the second function to relay terminal A and relay terminal B respectively, configuring the second function A for relay terminal A and configuring the second function B for relay terminal B.

[0286] It is understood that after relay terminal B is configured with the second function B, upon receiving the second indication information A sent by relay terminal A, it triggers the sending of the second indication information B to the first access network device, causing the first access network device to obtain the result of the remote terminal receiving the first data. The second indication information B is used to cause the first access network device to obtain the result of the remote terminal receiving the first data, and the second indication information A is used to cause relay terminal B to obtain the result of the remote terminal receiving the first data.

[0287] Based on the above technical solution, before the first access network device performs downlink data transmission, the first access network device will configure the second function for the relay terminal, so that after the first access network device confirms that the data has been successfully transmitted to the remote terminal, the RLC layer entity of the first access network device will send an indication message to the PDCP layer entity to indicate that the data transmission is successful, and thereby the first access network device can also be informed of the data that has not been successfully transmitted to the remote terminal. When the remote terminal undergoes a path switch, the data that has not been successfully transmitted to the remote terminal will be re-sent to the remote terminal by the second access network device, and the data that has not been successfully transmitted to the remote terminal will not be missed, thereby avoiding data loss. This achieves lossless transmission of data during terminal switching in the relay scenario, ensuring business continuity.

[0288] For example, the present invention also provides a communication method. Figure 8 As shown, the method includes steps S801-S806, and can be applied to uplink data transmission in a relay scenario.

[0289] S801. A remote terminal sends first data to a first access network device through a relay terminal.

[0290] The first data may include multiple data packets. Further, the first data may include multiple data packets sent simultaneously or multiple data packets sent successively.

[0291] Optionally, the first data has a first identifier, which may include a serial number of the first data.

[0292] It is understandable that each data packet in the first data has a corresponding number. For example, the first data includes four data packets, and the corresponding numbers of these data packets are #100, #101, #102, and #103.

[0293] S802. After receiving the first data, the relay terminal sends first indication information to the remote terminal.

[0294] Optionally, the first indication information includes a first identifier of the first data.

[0295] Optionally, the first indication information is included in an RLC control PDU. Exemplarily, the RLC control PDU may be an RLC status report.

[0296] Optionally, the first indication information includes a number of the first data and reception confirmation information of the first data. The reception confirmation information of the first data is used to indicate whether the relay terminal has successfully received the data corresponding to each number in the first data.

[0297] S803. The first access network device sends second indication information to the remote terminal.

[0298] Optionally, the second indication information is included in a PDCP status report fed back by the first access network device to the remote terminal.

[0299] Optionally, the first access network device carries the second indication information through the PDCP control PDU to send it to the remote terminal. Exemplarily, the second indication information includes a COUNT value, which is the highest COUNT value of the PDCP SDU continuously received by the first access network device, or the highest COUNT value plus 1, and is updated according to the data packet in the received first data. Exemplarily, the COUNT value can be the RX_DELIV parameter maintained by the receiving side PDCP layer entity of the first access network device. The RX_DELIV parameter is a state variable maintained by the receiving side PDCP layer entity, indicating the COUNT value of the first PDCP SDU that has not yet been submitted to the upper layer and is still waiting to be received.

[0300] Optionally, the first access network device may periodically send the second indication information to the remote terminal; or, after receiving a request message from the remote terminal, the first access network device feeds back the second indication information to the remote terminal. The request message is used to request the first access network device to send the second indication information.

[0301] S804. The remote terminal determines the second data according to the second indication information.

[0302] Optionally, the remote terminal maintains a variable for recording the COUNT value received from the first access network device through the second indication information. The variable can be initialized to 0, and each time the second indication information is received, the variable is updated to the COUNT value indicated in the second indication information. The remote terminal uses the PDCP SDU corresponding to the COUNT value recorded in the variable as the first data packet included in the second data. For example, the COUNT value included in the second indication information is #101. After receiving the second indication information, the remote terminal updates the maintained variable to #101 and uses the PDCP SDU corresponding to #101 as the first data packet included in the second data.

[0303] S805. The remote terminal switches from the first access network device to the second access network device.

[0304] Optionally, after the remote terminal switches from the first access network device to the second access network device, it can connect to the second access network device through a relay terminal to transmit data, or directly connect to the second access network device to transmit data.

[0305] It can be understood that if the remote terminal is still not within the coverage of the second access network device after switching from the first access network device to the second access network device, the remote terminal is connected to the second access network device through the relay terminal to transmit data; if the remote terminal is within the coverage of the second access network device after switching from the first access network device to the second access network device, the remote terminal is directly connected to the second access network device to transmit data.

[0306] S806. The remote terminal sends second data to the second access network device.

[0307] Optionally, the remote terminal sends the second data to the second access network device through the relay terminal; or, the remote terminal sends the second data directly to the second access network device.

[0308] It is understandable that, for data successfully transmitted to the first access network device before the remote terminal switches from the first access network device to the second access network device, the first access network device can forward the data packets that are not delivered to the core network to the second access network device.

[0309] Optionally, in the above embodiment, the function of the CONUT value may also be replaced by the SN.

[0310] Based on the above technical solution, the first access network device will feedback the COUNT value or SN to the remote terminal, allowing the remote terminal to know which data has been successfully uploaded to the first access network device and, therefore, which data has not been successfully transmitted to the access network device. When the remote terminal experiences a path switch, the data that has not been successfully transmitted to the access network device will be resent by the remote terminal to the access network device, preventing data loss. This enables lossless data transmission during terminal switching in relay scenarios, ensuring service continuity.

[0311] For example, the present invention also provides a communication method. Figure 9 As shown, the method includes steps S901-S908, and can be applied to downlink data transmission in a relay scenario.

[0312] S901. A first access network device sends configuration information of a third function to a remote terminal through a relay terminal.

[0313] Among them, the third function is used for the remote terminal to send a second indication message to the first access network device after receiving the first data. The second indication message includes a COUNT value, which is the highest COUNT value of the PDCP SDU continuously received by the first access network device, or the highest COUNT value plus 1, and is updated according to the data packet in the received first data. Exemplarily, the COUNT value can be the RX_DELIV parameter maintained by the receiving side PDCP layer entity of the first access network device. The RX_DELIV parameter is a state variable maintained by the receiving side PDCP layer entity, indicating the COUNT value of the first PDCP SDU that has not yet been submitted to the upper layer and is still waiting to be received.

[0314] Optionally, the remote terminal may periodically send a second indication message to the first access network device. Exemplarily, the first access network device configures a timer for the remote terminal, such as count_feedback_Timer, and starts the timer when the PDCP layer entity of the remote terminal receives the first downlink PDCP PDU. When the timer times out, the remote terminal triggers the generation and sends the second indication message to the first access network device, and then the remote terminal restarts the timer count_feedback_Timer. Optionally, when the timer times out, the remote terminal determines that the highest COUNT value of the continuously received PDCP PDU is different from the value fed back last time, or the COUNT value has not been fed back, and then triggers the generation and sends the second indication message to the first access network device, and then restarts the timer. Otherwise, the timer can be restarted directly. Alternatively, after receiving the request information from the first access network device, the remote terminal feeds back the second indication information to the first access network device. The request message is used to request the remote terminal to send the second indication information.

[0315] S902: The first access network device sends first data to the remote terminal through the relay terminal.

[0316] The first data may include multiple data packets. Further, the first data may include multiple data packets sent simultaneously or multiple data packets sent successively.

[0317] Optionally, the first data has a first identifier, which may include a serial number of the first data.

[0318] It is understandable that each data packet in the first data has a corresponding number. For example, the first data includes four data packets, and the corresponding numbers of these data packets are #100, #101, #102, and #103.

[0319] S903. After receiving the first data, the relay terminal sends first indication information to the first access network device.

[0320] Optionally, the first indication information is an RLC status report fed back by the relay terminal to the first access network device.

[0321] Optionally, the first indication information includes a number of the first data and reception confirmation information of the first data. The reception confirmation information of the first data is used to indicate whether the relay terminal has successfully received the data corresponding to each number in the first data.

[0322] S904. The remote terminal sends second indication information to the first access network device.

[0323] S905. The first access network device determines second data according to the second indication information.

[0324] Optionally, the first access network device maintains a variable for recording a COUNT value received from the remote terminal via the second indication information. The variable may be initialized to 0 and updated to the COUNT value indicated in the second indication information each time the second indication information is received. The first access network device uses the PDCP SDU corresponding to the COUNT value recorded in the variable as the first data packet included in the second data.

[0325] Exemplarily, the COUNT value included in the second indication information is #101. After receiving the second indication information, the first access network device updates the maintained variable to #101 and uses the PDCP SDU corresponding to #101 as the first data packet included in the second data.

[0326] S906. The remote terminal switches from the first access network device to the second access network device.

[0327] Optionally, after the remote terminal switches from the first access network device to the second access network device, it can connect to the second access network device through a relay terminal to transmit data, or directly connect to the second access network device to transmit data.

[0328] It can be understood that if the remote terminal is still not within the coverage of the second access network device after switching from the first access network device to the second access network device, the remote terminal is connected to the second access network device through the relay terminal to transmit data; if the remote terminal is within the coverage of the second access network device after switching from the first access network device to the second access network device, the remote terminal is directly connected to the second access network device to transmit data.

[0329] S907: The first access network device forwards the second data to the second access network device.

[0330] S908. The second access network device sends second data to the remote terminal.

[0331] Optionally, the second access network device sends the second data to the remote terminal through the relay terminal; or, the second access network device sends the second data directly to the remote terminal.

[0332] Optionally, in the above embodiment, the function of the CONUT value may also be replaced by the SN.

[0333] Based on the above technical solution, before the first access network device performs downlink data transmission, the first access network device will configure a third function for the remote terminal, so that the remote terminal can feedback the COUNT value or SN to the first access network device, so that the first access network device can know which data has been successfully uploaded to the remote terminal, and the first access network device can also know the data that has not been successfully transmitted to the remote terminal. When the remote terminal undergoes a path switch, the data that has not been successfully transmitted to the remote terminal will be resent to the access network device by the second access network device, and the data that has not been successfully transmitted to the remote terminal will not be missed, thus avoiding data loss. This achieves lossless transmission of data during terminal switching in the relay scenario, ensuring business continuity.

[0334] For example, the present invention also provides a communication method. Figure 10 As shown, the method includes steps S1001-S1006, and can be applied to uplink data transmission in a relay scenario.

[0335] S1001. A first access network device sends configuration information of a fourth function to a remote terminal through a relay terminal.

[0336] The fourth function is to cause the RLC layer entity of the remote terminal to delay for a first duration after receiving the RLC control PDU sent by the relay terminal before sending an indication of successful first data transmission to the PDCP layer entity. The first duration can be set by the remote terminal based on actual data transmission conditions or configured for the remote terminal by the first access network device.

[0337] For example, a timer, such as a delay_ACK_Indication-Timer, can be used to control the AM RLC layer entity to delay for a first period of time before sending an indication of successful data transmission to the PDCP layer entity. After the RLC layer entity of the remote terminal receives the RLC control PDU fed back by the relay terminal, it starts a timer for the RLC control PDU. When the timer expires, it feeds back the successfully transmitted data in the RLC control PDU, and the remote terminal then sends an indication of successful data transmission to the PDCP layer entity.

[0338] Optionally, in step S1001, the RLC control PDU may be an RLC status report, and subsequent steps S1002-S1006 are described by taking the RLC control PDU being the RLC status report as an example.

[0339] S1002. The remote terminal sends first data to the first access network device through the relay terminal.

[0340] The first data may include multiple data packets. Further, the first data may include multiple data packets sent simultaneously or multiple data packets sent successively.

[0341] Optionally, the first data has a first identifier, which may include a serial number of the first data.

[0342] It is understood that each data packet in the first data has a corresponding number, which is the number corresponding to the data at the RLC layer. For example, the first data includes four data packets, and the corresponding numbers of these data packets are #100, #101, #102, and #103.

[0343] S1003. The relay terminal sends an RLC status report to the remote terminal.

[0344] S1004. The RLC layer entity of the remote terminal sends an indication message of successful first data transmission to the PDCP layer entity after the first duration.

[0345] It is understandable that, after receiving the RLC status report sent from the relay terminal, the RLC layer entity of the remote terminal indicates to the PDCP layer entity the indication information indicating successful transmission of the data packet in the first data after the first time period has passed. By setting the first time period, a period of time can be reserved for transmission of the first data between the relay terminal and the first access network device. During this period of time, the relay terminal can successfully transmit the first data to the first access network device.

[0346] Optionally, after receiving the RLC status report fed back by the first access network device, the relay terminal retransmits, to the first access network device within a first duration, the data that the first access network device failed to receive. For example, if the relay terminal successfully receives data numbered #100, #101, and #102, and the RLC status report fed back by the first access network device indicates that the first access network device successfully received data numbered #100, then within the first duration, the relay terminal retransmits data numbered #101 and #102 to the first access network device.

[0347] S1005. The remote terminal switches from the first access network device to the second access network device.

[0348] Optionally, after the remote terminal switches from the first access network device to the second access network device, it can connect to the second access network device through a relay terminal to transmit data, or directly connect to the second access network device to transmit data.

[0349] It can be understood that if the remote terminal is still not within the coverage of the second access network device after switching from the first access network device to the second access network device, the remote terminal is connected to the second access network device through the relay terminal to transmit data; if the remote terminal is within the coverage of the second access network device after switching from the first access network device to the second access network device, the remote terminal is directly connected to the second access network device to transmit data.

[0350] S1006. The remote terminal sends second data to the second access network device.

[0351] The second data includes that the PDCP layer of the remote terminal does not receive the PDCP SDU indicated by the RLC layer as having been successfully transmitted.

[0352] Optionally, the second data includes the first PDCP SDU for which the PDCP layer of the remote terminal does not receive an indication of successful transmission from the RLC layer, and subsequent consecutive PDCP SDUs.

[0353] Optionally, the remote terminal sends the second data to the second access network device through the relay terminal; or, the remote terminal sends the second data directly to the second access network device.

[0354] It is understandable that, for data successfully transmitted to the first access network device before the remote terminal switches from the first access network device to the second access network device, the first access network device can forward the data packets that are not delivered to the core network to the second access network device.

[0355] Based on the above technical solution, before the remote terminal performs uplink data transmission, the first access network device will configure the fourth function for the remote terminal, so that after the remote terminal receives the RLC status report from the relay terminal, it will send indication information to the PDCP layer entity after the first time period to indicate that the data transmission is successful. A period of time is reserved for the transmission of the first data between the relay terminal and the first access network device, during which the relay terminal can successfully transmit the first data to the first access network device. Therefore, when the remote terminal undergoes path switching, the remote terminal continues to upload data starting from the data that was not successfully transmitted as fed back by the relay terminal before the switching, and will not miss the data that was not successfully transmitted to the access network device, thereby avoiding data loss. This achieves lossless transmission of data when the terminal switches in the relay scenario, ensuring business continuity.

[0356] For example, the present invention also provides a communication method. Figure 11 As shown, the method includes steps S1101-S1106, and can be applied to downlink data transmission in a relay scenario.

[0357] S1101. A first access network device sends first data to a remote terminal through a relay terminal.

[0358] The first data may include multiple data packets. Further, the first data may include multiple data packets sent simultaneously or multiple data packets sent successively.

[0359] Optionally, the first data has a first identifier, which may include a serial number of the first data.

[0360] It is understood that each data packet in the first data has a corresponding number, which is the number corresponding to the data packet at the RLC layer. For example, the first data includes four data packets, and the corresponding numbers of these data packets are #100, #101, #102, and #103.

[0361] Optionally, after the first access network device sends the first data to the remote terminal via the relay terminal, the relay terminal sends an RLC control PDU to the first access network device. Exemplarily, the RLC control PDU may be an RLC status report. Subsequent steps S1102-S1106 are described using the RLC control PDU being an RLC status report as an example.

[0362] S1102. The relay terminal sends an RLC status report to the first access network device.

[0363] S1103. After a first time period, the first access network device sends an indication message of successful first data transmission to the PDCP layer entity.

[0364] It can be understood that after the RLC layer entity of the first access network device receives the RLC status report sent from the relay terminal, it will send an indication of the successful transmission of the data packet in the first data to the PDCP layer entity after the first time period. By setting the first time period, a period of time can be reserved for the transmission of the first data between the relay terminal and the remote terminal. During this period of time, the relay terminal can successfully transmit the first data to the remote terminal. Among them, the first time period can be specifically set by the first access network device according to the actual data transmission situation, or by the centralized unit (Central Unit, CU) of the first access network device according to the actual situation, and notified to the distributed unit (Distributed Unit, DU) through the F1 interface message transmitted between the centralized unit and the remote terminal.

[0365] Optionally, after receiving the RLC status report fed back by the remote terminal, the relay terminal retransmits the data that the remote terminal failed to receive to the remote terminal within a first duration. For example, if the relay terminal successfully receives data numbered #100, #101, and #102, and the RLC status report fed back by the remote terminal indicates that the remote terminal successfully received data numbered #100, then within the first duration, the relay terminal retransmits data numbered #101 and #102 to the remote terminal.

[0366] S1104. The remote terminal switches from the first access network device to the second access network device.

[0367] Optionally, after the remote terminal switches from the first access network device to the second access network device, it can connect to the second access network device through a relay terminal to transmit data, or directly connect to the second access network device to transmit data.

[0368] It can be understood that if the remote terminal is still not within the coverage of the second access network device after switching from the first access network device to the second access network device, the remote terminal is connected to the second access network device through the relay terminal to transmit data; if the remote terminal is within the coverage of the second access network device after switching from the first access network device to the second access network device, the remote terminal is directly connected to the second access network device to transmit data.

[0369] S1105. The first access network device sends second data to the second access network device.

[0370] The second data includes that the PDCP layer of the remote terminal does not receive the PDCP SDU indicated by the RLC layer as having been successfully transmitted.

[0371] Optionally, the second data includes the first PDCP SDU for which the PDCP layer of the remote terminal does not receive an indication of successful transmission from the RLC layer, and subsequent consecutive PDCP SDUs.

[0372] S1106. The second access network device sends second data to the remote terminal.

[0373] Optionally, the second access network device sends the second data to the remote terminal through the relay terminal; or, the second access network device sends the second data directly to the remote terminal.

[0374] Based on the above technical solution, after receiving the RLC status report from the relay terminal, the first access network device will send an indication message to the PDCP layer entity after a first period of time, indicating that the data transmission is successful. A period of time is reserved for the transmission of the first data between the relay terminal and the remote terminal. During this period of time, the relay terminal can successfully transmit the first data to the remote terminal. When the remote terminal undergoes a path switch, the second access network device starts from the data that was not successfully transmitted and fed back by the relay terminal before the switch, and continues to upload data. Data that was not successfully transmitted to the remote terminal will not be missed, thus avoiding data loss. This achieves lossless transmission of data during terminal switching in the relay scenario, ensuring business continuity.

[0375] For example, the present invention also provides a communication method. Figure 12 As shown, the method includes steps S1201-S1206, and can be applied to uplink data transmission in a relay scenario.

[0376] S1201. A remote terminal sends first data to a first access network device through a relay terminal.

[0377] The first data may include multiple data packets. Further, the first data may include multiple data packets sent simultaneously or multiple data packets sent successively.

[0378] Optionally, the first data has a first identifier, which may include a serial number of the first data.

[0379] It is understood that each data packet in the first data has a corresponding number, which is the number corresponding to the data at the RLC layer. For example, the first data includes four data packets, and the corresponding numbers of these data packets are #100, #101, #102, and #103.

[0380] Optionally, after the remote terminal sends the first data to the first access network device via the relay terminal, the relay terminal sends an RLC control PDU to the remote terminal. Exemplarily, the RLC control PDU may be an RLC status report. The subsequent steps S1202-S1206 are described using the RLC control PDU being an RLC status report as an example.

[0381] S1202. The relay terminal sends an RLC status report to the remote terminal.

[0382] S1203. The remote terminal switches from the first access network device to the second access network device.

[0383] Optionally, after the remote terminal switches from the first access network device to the second access network device, it can connect to the second access network device through a relay terminal to transmit data, or directly connect to the second access network device to transmit data.

[0384] It can be understood that if the remote terminal is still not within the coverage of the second access network device after switching from the first access network device to the second access network device, the remote terminal is connected to the second access network device through the relay terminal to transmit data; if the remote terminal is within the coverage of the second access network device after switching from the first access network device to the second access network device, the remote terminal is directly connected to the second access network device to transmit data.

[0385] S1204. The second access network device sends a PDCP status report to the remote terminal.

[0386] S1205. The remote terminal determines the second data.

[0387] Optionally, the remote terminal determines the data indicated in the PDCP status report as not successfully transmitted to the first access network device as the second data.

[0388] Optionally, the remote terminal determines the data packet indicated in the PDCP status report as the second data, which is not successfully transmitted to the first access network device and is not sent to the second access network device after the handover is completed.

[0389] S1206. The remote terminal sends second data to the second access network device.

[0390] Optionally, the remote terminal sends the second data to the second access network device through the relay terminal; or, the remote terminal sends the second data directly to the second access network device.

[0391] It can be understood that, for data successfully transmitted to the first access network device before the remote terminal switches from the first access network device to the second access network device, the second access network device can send a request to the first access network device, requesting the first access network device to send the data to the second access network device.

[0392] Optionally, in the above embodiment, the function of the CONUT value may also be replaced by the SN.

[0393] Optionally, in the above embodiment, after the remote terminal switches from the first access network device to the second access network device, the remote terminal directly sends the second data to the second access network device. In this case, the second data also includes PDCP SDUs corresponding to packets with M COUNT or SN values ​​preceding the COUNT or SN value of the first unsuccessfully transmitted packet. The value of M is determined by the remote terminal.

[0394] For example, the COUNT values ​​corresponding to the data packets that were not successfully transmitted are #101, #102, and #103. After the remote terminal switches from the first access network device to the second access network device, the remote terminal directly sends the PDCP SDU corresponding to the data packets with CONUT values ​​of #98, #99, #100, #101, #102, and #103 to the second access network device.

[0395] It can be understood that after the remote terminal switches from the first access network device to the second access network device, the remote terminal directly sends the second data determined by the remote terminal to the second access network device, and the second access network device does not need to provide additional feedback on the transmission results of the first data, thereby reducing the signaling interaction between the remote terminal and the second access network device and saving network resources.

[0396] Based on the above technical solution, after a path switch occurs at a remote terminal, the remote terminal learns about data that was not successfully transmitted to the access network device based on the PDCP report sent by the second access network device and retransmits this data, preventing any missed data and thus avoiding data loss. This enables lossless data transmission during terminal handover in relay scenarios, ensuring service continuity.

[0397] For example, the present invention also provides a communication method. Figure 13 As shown, the method includes steps S1301-S1308, and can be applied to downlink data transmission in a relay scenario.

[0398] S1301. A first access network device sends first data to a remote terminal through a relay terminal.

[0399] The first data may include multiple data. Further, the first data may include multiple data sent simultaneously or multiple data sent successively.

[0400] Optionally, the first data has a first identifier, which may include a serial number of the first data.

[0401] It is understandable that each data in the first data has a corresponding number, which is the number corresponding to the data in the RLC layer. For example, the first data includes four data packets, and the corresponding numbers of these data packets are #100, #101, #102, and #103.

[0402] Optionally, after the first access network device sends the first data to the remote terminal via the relay terminal, the relay terminal sends an RLC control PDU to the first access network device. Exemplarily, the RLC control PDU may be an RLC status report. Subsequent steps S1302-S1308 are described using the RLC control PDU being an RLC status report as an example.

[0403] S1302. The relay terminal sends an RLC status report to the first access network device.

[0404] S1303. The remote terminal switches from the first access network device to the second access network device.

[0405] Optionally, after the remote terminal switches from the first access network device to the second access network device, it can connect to the second access network device through a relay terminal to transmit data, or directly connect to the second access network device to transmit data.

[0406] It can be understood that if the remote terminal is still not within the coverage of the second access network device after switching from the first access network device to the second access network device, the remote terminal is connected to the second access network device through the relay terminal to transmit data; if the remote terminal is within the coverage of the second access network device after switching from the first access network device to the second access network device, the remote terminal is directly connected to the second access network device to transmit data.

[0407] S1304. The remote terminal sends a PDCP status report to the second access network device.

[0408] S1305. The second access network device determines second data.

[0409] Optionally, the second access network device determines the data indicated in the PDCP status report as not successfully transmitted to the remote terminal as the second data.

[0410] Optionally, the second access network device determines the data packet indicated in the PDCP status report as not successfully transmitted to the remote terminal and not sent to the remote terminal after the handover is completed as the second data.

[0411] S1306. The second access network device sends a first request to the first access network device.

[0412] The first request is used to request the second access network device to send the PDCP SDU and COUNT value corresponding to the second data to the first access network device.

[0413] Optionally, the first request may include information such as the data radio bearer identifier DRB ID and / or the data forwarding tunnel endpoint identifier.

[0414] Optionally, the first request may include information contained in a PDCP status report sent by the remote terminal.

[0415] S1307. The first access network device sends the PDCP SDU and COUNT value corresponding to the second data to the first access network device.

[0416] S1308. The second access network device sends second data to the remote terminal.

[0417] Optionally, the second access network device sends the second data to the remote terminal through the relay terminal; or, the second access network device sends the second data directly to the remote terminal.

[0418] Optionally, in the above embodiment, the function of the CONUT value may also be replaced by the SN.

[0419] Optionally, in the above embodiment, after the remote terminal switches from the first access network device to the second access network device, the first access network device directly sends the second data to the second access network device. In this case, the second data also includes PDCP SDUs corresponding to packets with N COUNT or SN values ​​preceding the COUNT or SN value of the first unsuccessfully transmitted packet. The value of N is determined by the first access network device.

[0420] For example, the COUNT values ​​corresponding to the data packets that were not successfully transmitted are #101, #102, and #103. After the remote terminal switches from the first access network device to the second access network device, the first access network device directly sends the PDCP SDU corresponding to the data packets with CONUT values ​​of #98, #99, #100, #101, #102, and #103 to the second access network device.

[0421] It can be understood that after the remote terminal switches from the first access network device to the second access network device, the first access network device directly sends the second data determined by the first access network device to the second access network device, avoiding the second access network device from sending an additional request message to request forwarding of the data packet, thereby reducing the signaling interaction between the first access network device and the second access network device and saving network resources.

[0422] Based on the above technical solution, after a path switch occurs at a remote terminal, the second access network device learns of the data that was not successfully transmitted to the remote terminal based on the PDCP report sent by the remote terminal, and requests the first access network device to forward the PDCP SDU and COUNT value or SN of this data. The device then retransmits this data to the remote terminal, preventing any data that was not successfully transmitted to the remote terminal from being missed and thus avoiding data loss. This enables lossless data transmission during terminal handover in relay scenarios, ensuring service continuity.

[0423] It should be noted that in specific implementations, some of the steps in the corresponding diagrams may be selected for implementation, and the order of the steps in the diagrams may be adjusted for implementation, and this application does not limit this. It should be understood that implementing some of the steps in the diagrams or adjusting the order of the steps for specific implementation falls within the scope of protection of this application.

[0424] The above mainly introduces the solution provided by the embodiment of the present application from the perspective of method steps. It is understandable that, in order to implement the above functions, the computer includes a hardware structure and / or software module corresponding to each function. Those skilled in the art should easily appreciate that, in combination with the modules and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of a combination of hardware and computer software. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0425] The embodiment of the present application can divide the computer into functional modules according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical function division. In actual implementation, there may be other division methods.

[0426] Combination of the above Figure 4-13 The communication method provided by the embodiment of the present application is described in detail. Figure 14-17 The communication device provided in the embodiments of the present application is described in detail.

[0427] For example, Figure 14 This is a schematic diagram of the structure of a communication device provided in an embodiment of the present application. Figure 14 As shown, the communication device 1400 includes: a receiving module 1401, a processing module 1402 and a sending module 1403. For ease of description, Figure 14 Only the main components of the communication device are shown.

[0428] In a possible embodiment, the receiving module 1401 is configured to receive first indication information from a relay terminal.

[0429] The receiving module 1401 is further configured to receive second indication information.

[0430] The processing module 1402 is configured to determine second data according to the second indication information; the second data includes data in the first data that is not received by the first access network device.

[0431] The sending module 1403 is configured to send the second data to the relay terminal or the second access network device.

[0432] Optionally, the processing module 1402 is further configured to determine second data according to the first indication information and the second indication information.

[0433] Optionally, the receiving module 1401 is further configured to receive configuration information of the first function from the first access network device.

[0434] Optionally, the processing module 1402 is further configured to determine the second data according to the third indication information.

[0435] In another possible embodiment, Figure 14 The sending module 1403 is used to send the second data to the relay terminal or the remote terminal.

[0436] Optionally, the processing module 1402 is further configured to determine second data based on the first indication information and the second indication information; the second data includes data in the first data that is not received by the remote terminal.

[0437] Optionally, the sending module 1403 is further configured to send configuration information of the second function to the relay terminal.

[0438] also, Figure 14 The technical effects of the communication device can refer to the technical effects of the communication method described in the above embodiment, and will not be repeated here.

[0439] For example, Figure 15 This is a schematic diagram of the structure of another communication device provided in an embodiment of the present application. Figure 15 As shown, the communication device 1500 includes: a sending module 1501. For the convenience of explanation, Figure 15 Only the main components of the communication device are shown.

[0440] In a possible embodiment, the sending module 1501 is configured to send first indication information to a remote terminal.

[0441] The sending module 1501 is further configured to send second indication information to the remote terminal.

[0442] The sending module 1501 is further configured to send second data to the second access network device.

[0443] Optionally, the communication device 1500 further includes a receiving module 1502 ( Figure 15 (shown by dotted lines): Receiving module 1502, used to receive second indication information from the first access network device.

[0444] Optionally, the sending module 1501 is further configured to send second indication information from the first access network device to the remote terminal.

[0445] Optionally, the receiving module 1502 is further configured to receive configuration information of a third function from the first access network device.

[0446] In another possible embodiment, Figure 15The sending module 1501 is used to send the first indication information to the first access network device.

[0447] The sending module 1501 is further configured to send second indication information to the first access network device.

[0448] The sending module 1501 is further configured to send second data to the remote terminal.

[0449] Optionally, the receiving module 1502 is configured to receive second indication information from a remote terminal.

[0450] Optionally, the sending module 1501 is further configured to send second indication information from the remote terminal to the first access network device.

[0451] Optionally, the receiving module 1502 is further configured to receive configuration information of a second function from the first access network device.

[0452] also, Figure 15 The technical effects of the communication device can refer to the technical effects of the communication method described in the above embodiment, and will not be repeated here.

[0453] For example, Figure 16 This is a schematic diagram of the structure of another communication device provided in an embodiment of the present application. Figure 16 As shown, the communication device 1600 includes: a sending module 1601 and a receiving module 1602. For ease of description, Figure 16 Only the main components of the communication device are shown.

[0454] In a possible embodiment, the sending module 1601 is configured to send second indication information to a remote terminal.

[0455] The receiving module 1602 is configured to receive second data from a relay terminal or a remote terminal.

[0456] Optionally, the sending module 1601 is further configured to send configuration information of the first function to the remote terminal.

[0457] In another possible embodiment, Figure 16 The sending module 1601 is used to send the second indication information to the first access network device.

[0458] The receiving module 1602 is configured to receive second data sent by the relay terminal or the second access network device.

[0459] also, Figure 16 The technical effects of the communication device can refer to the technical effects of the communication method described in the above embodiment, and will not be repeated here.

[0460] For example, Figure 17It is a structural diagram of another communication device provided in an embodiment of the present application.

[0461] The communication device may be a terminal device or a network device, or may be a chip (system) or other component or assembly that can be provided in the terminal device or the network device. Figure 17 As shown, the communication device 1700 may include a processor 1701. Optionally, the communication device 1700 may further include a memory 1702 and / or a transceiver 1703. The processor 1701 is coupled to the memory 1702 and the transceiver 1703, for example, via a communication bus.

[0462] The following combination Figure 17 The components of the communication device 1700 are described in detail.

[0463] The processor 1701 is the control center of the communication device 1700 and can be a single processor or a collective term for multiple processing elements. For example, the processor 1701 can be one or more central processing units (CPUs), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application, such as one or more digital signal processors (DSPs) or one or more field programmable gate arrays (FPGAs).

[0464] Optionally, the processor 1701 may execute various functions of the communication device 1700 by running or executing a software program stored in the memory 1702 and calling data stored in the memory 1702 .

[0465] In a specific implementation, as an embodiment, the processor 1701 may include one or more CPUs.

[0466] In a specific implementation, as an embodiment, the communication device 1700 may also include multiple processors, each of which may be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). The processor here may refer to one or more communication devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0467] Among them, the memory 1702 is used to store the software program for executing the solution of this application, and the execution is controlled by the processor 1701. The specific implementation method can refer to the above method embodiment and will not be repeated here.

[0468] Alternatively, the memory 1702 may be a read-only memory (ROM) or other type of static storage communication device that can store static information and instructions, a random access memory (RAM) or other type of dynamic storage communication device 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 compact disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage communication device, or any other medium that can be used to carry or store 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 1702 may be integrated with the processor 1701 or exist independently and access the processor 1701 through the input / output port ( Figure 17 (not shown) is coupled to the processor 1701, and this embodiment of the present application does not specifically limit this.

[0469] Transceiver 1703 is used for communication with other communication devices. For example, if communication device 1700 is a terminal device, transceiver 1703 can be used to communicate with a network device or another terminal device. For another example, if communication device 1700 is a network device, transceiver 1703 can be used to communicate with a terminal device or another network device.

[0470] Optionally, the transceiver 1703 may include a receiver and a transmitter ( Figure 17 (not shown separately in the figure). The receiver is used to implement a receiving function, and the transmitter is used to implement a sending function.

[0471] Optionally, the transceiver 1703 may be integrated with the processor 1701 or may exist independently and communicate with the processor 1701 via the input / output port ( Figure 17 (not shown) is coupled to the processor 1701, and this embodiment of the present application does not specifically limit this.

[0472] It should be noted that Figure 17The structure of the communication device 1700 shown in the figure does not constitute a limitation on the communication device. The actual communication device may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0473] The embodiment of the present application further provides a communication system, which includes one or more terminal devices and one or more network devices.

[0474] It should be understood that the processor in the embodiments of the present application may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0475] It should also be understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of random access memory (RAM) are available, such as static RAM (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0476] The above embodiments can be implemented in whole or in part by software, hardware (such as circuits), firmware or any other combination. When implemented using software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer program are loaded or executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (such as infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that contains one or more available media sets. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a tape), an optical medium (for example, a DVD), or a semiconductor medium. The semiconductor medium can be a solid-state drive.

[0477] It should be understood that the term "and / or" as used herein simply describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A alone, A and B together, or B alone. A and B can be singular or plural. Furthermore, the character " / " as used herein generally indicates an "or" relationship between the associated objects, but it may also indicate an "and / or" relationship. For specific understanding, please refer to the context.

[0478] In this application, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or plural.

[0479] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0480] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0481] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0482] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, 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.

[0483] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0484] 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.

[0485] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0486] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A communication method, applied to a remote terminal, characterized in that: The method comprises: Receiving first indication information from a relay terminal; wherein the first indication information is used to indicate that the relay terminal has received first data, and the first data is data sent to a first access network device; Receive second indication information; wherein the second indication information is used to indicate whether the first access network device has received the first data; Determining second data according to the first indication information and the second indication information; the second data includes data in the first data that is not received by the first access network device; Send the second data to the relay terminal or the second access network device.

2. The method according to claim 1, characterized in that The method further comprises: After the remote terminal switches from the first access network device to the second access network device, the second data is sent to the relay terminal or the second access network device.

3. The method according to claim 2, characterized in that The second indication information comes from the relay terminal or the first access network device.

4. The method according to any one of claims 1 to 3, characterized in that The method comprises: The first indication information is included in a radio link control RLC control protocol data unit PDU; wherein the first indication information includes a first identifier of the first data and reception confirmation information of the first data; the reception confirmation information of the first data is used to indicate whether the relay terminal has successfully received each data in the first data; The second indication information is included in a Packet Data Convergence Protocol (PDCP) control PDU; wherein the second indication information includes a second identifier of the first data; the second indication information is used to indicate whether the first access network device has successfully received each data in the first data.

5. The method according to claim 4, characterized in that The method comprises: The first identifier includes the serial number of the first data; The second identifier includes a count COUNT value or a sequence number SN of the first data.

6. The method according to any one of claims 1 to 3, characterized in that The method comprises: Receive configuration information of a first function from the first access network device; wherein, the first function is used by the remote terminal to determine third indication information based on the first indication information and / or the second indication information; the third indication information is used to indicate the data in the first data that is successfully received by the first access network device.

7. The method according to claim 6, characterized in that The method further comprises: The second data is determined according to the third indication information.

8. A communication method, characterized in that: The method comprises: The first access network device receives first indication information from the relay terminal; wherein the first indication information is used to indicate that the relay terminal has received first data, and the first data is data sent to the remote terminal; The first access network device receives second indication information; wherein the second indication information is used to indicate whether the remote terminal has received the first data; The first access network device determines second data according to the first indication information and the second indication information; the second data includes data in the first data that is not received by the remote terminal; The second access network device sends the second data to the relay terminal or the remote terminal.

9. The method according to claim 8, characterized in that The method further comprises: After the remote terminal switches from the first access network device to the second access network device, the second access network device sends the second data to the relay terminal or the remote terminal.

10. The method according to claim 9, characterized in that The second indication information comes from the relay terminal or the remote terminal.

11. The method according to any one of claims 8 to 10, characterized in that: The method comprises: The first indication information is included in the RLC control PDU; wherein the first indication information includes a first identifier of the first data and reception confirmation information of the first data; the reception confirmation information of the first data is used to indicate whether the relay terminal has successfully received the data corresponding to each count value or sequence number in the first data; The second indication information is included in the PDCP control PDU; wherein, the second indication information includes a second identifier of the first data.

12. The method according to claim 11, characterized in that The method comprises: The first identifier includes the serial number of the first data; The second identifier includes a count COUNT value or a sequence number SN of the first data.

13. The method according to any one of claims 8 to 10, characterized in that: The method comprises: The first access network device sends configuration information of a second function to the relay terminal; wherein the second function is used by the relay terminal to send the second indication information to the first access network device.

14. The method according to claim 13, characterized in that The method comprises: The first access network device determines third indication information based on the first indication information and / or the second indication information; wherein the third indication information is used to indicate data in the first data that is successfully received by the first access network device.

15. The method according to claim 14, characterized in that The method comprises: The first access network device determines the second data according to the third indication information.

16. A communication method, characterized in that: Applied to a relay terminal, the method includes: Sending first indication information to the remote terminal; wherein the first indication information is used to indicate that the relay terminal has received first data, and the first data is data sent to the first access network device; Sending second indication information to the remote terminal; wherein the second data is determined based on the first indication information and the second indication information, and the second indication information is used to indicate whether the first access network device has received the first data; Sending second data to a second access network device; wherein the second data includes data in the first data that is not received by the first access network device.

17. The method according to claim 16, characterized in that The method further comprises: After the remote terminal switches from the first access network device to the second access network device, the second data from the remote terminal is sent to the second access network device.

18. The method according to claim 16 or 17, characterized in that The sending of the second instruction information to the remote terminal specifically includes: receiving the second indication information from the first access network device; The second indication information from the first access network device is sent to the remote terminal.

19. The method according to any one of claims 16-17, characterized in that The method comprises: The first indication information is included in the RLC control PDU; wherein the first indication information includes a first identifier of the first data and reception confirmation information of the first data; the reception confirmation information of the first data is used to indicate whether the relay terminal has successfully received each data in the first data; The second indication information is included in the PDCP control PDU; wherein, the second indication information includes a second identifier of the first data; the second indication information is used to indicate whether the first access network device has successfully received each data in the first data.

20. The method according to claim 19, characterized in that The method comprises: The first identifier includes the serial number of the first data; The second identifier includes a count COUNT value or a sequence number SN of the first data.

21. The method according to any one of claims 16-17, characterized in that The method comprises: Receive configuration information of a third function from the first access network device; wherein the third function is used by the relay terminal to send the first indication information to the remote terminal.

22. A communication method, characterized in that: Applied to a relay terminal, the method includes: Sending first indication information to the first access network device; wherein the first indication information is used to indicate that the relay terminal has received first data, and the first data is data sent to the remote terminal; Sending second indication information to the first access network device; wherein the second indication information is used to indicate whether the remote terminal has received the first data; Sending second data to the remote terminal; wherein the second data is determined based on the first indication information and the second indication information, and the second data includes data in the first data that is not received by the remote terminal.

23. The method according to claim 22, characterized in that The method further comprises: After the remote terminal switches from the first access network device to the second access network device, the second data is sent to the remote terminal.

24. The method according to claim 22 or 23, characterized in that The sending the second indication information to the first access network device specifically includes: receiving the second indication information from the remote terminal; Send the second indication information from the remote terminal to the first access network device.

25. The method according to any one of claims 22-23, characterized in that The method comprises: The first indication information is included in the RLC control PDU; wherein the first indication information includes a first identifier of the first data and reception confirmation information of the first data; the reception confirmation information of the first data is used to indicate whether the relay terminal has successfully received each data in the first data; The second indication information is included in the PDCP control PDU; wherein, the second indication information includes a second identifier of the first data; the second indication information is used to indicate whether the first access network device has successfully received each data in the first data.

26. The method according to claim 25, characterized in that The method comprises: The first identifier includes the serial number of the first data; The second identifier includes a count COUNT value or a sequence number SN of the first data.

27. The method according to any one of claims 22-23, characterized in that The method comprises: Receive configuration information of a second function from the first access network device; wherein the second function is used by the relay terminal to send the first indication information to the first access network device.

28. A communication method, characterized in that: The method comprises: The first access network device sends second indication information to the remote terminal through the relay terminal; wherein the second indication information is used to indicate whether the first access network device has received the first data, and the first data is data sent to the first access network device; The second access network device receives second data from the relay terminal or the remote terminal; wherein the second data is determined based on the second indication information, and the second data includes data in the first data that is not received by the first access network device.

29. The method according to claim 28, characterized in that The method further comprises: After the remote terminal switches from the first access network device to the second access network device, the second access network device receives the second data from the relay terminal or the remote terminal.

30. The method according to claim 28 or 29, characterized in that The method comprises: The second indication information is included in the PDCP control PDU; wherein, the second indication information includes a second identifier of the first data; the second indication information is used to indicate whether the first access network device has successfully received each data in the first data.

31. The method according to claim 30, wherein The method comprises: The second identifier includes a COUNT value or SN of the first data.

32. The method according to any one of claims 28-29, characterized in that The method comprises: The first access network device sends configuration information of a first function to the remote terminal; wherein the first function is used by the remote terminal to determine third indication information based on the first indication information and / or the second indication information; the third indication information is used to indicate the data in the first data that is successfully received by the first access network device.

33. A communication method, characterized in that: Applied to a remote terminal, the method includes: Sending second indication information to the first access network device through the relay terminal; wherein the second indication information is used to indicate whether the remote terminal has received the first data, and the first data is data sent to the remote terminal; Receive second data sent by the relay terminal or the second access network device; wherein the second data is determined based on the second indication information, and the second data includes data in the first data that is not received by the remote terminal.

34. The method according to claim 33, wherein The method further comprises: After the remote terminal switches from the first access network device to the second access network device, the remote terminal receives the second data sent from the relay terminal or the second access network device.

35. The method according to claim 33 or 34, characterized in that The method comprises: The second indication information is included in the PDCP control PDU; wherein, the second indication information includes a second identifier of the first data; the second indication information is used to indicate whether the first access network device has successfully received each data in the first data.

36. The method according to claim 35, characterized in that The method comprises: The second identifier includes a COUNT value or SN of the first data.

37. A communication device, characterized in that: The communication device includes a receiving module, a processing module and a sending module; The receiving module is configured to receive first indication information from the relay terminal; wherein the first indication information is used to indicate that the relay terminal has received first data, and the first data is data sent to the first access network device; The receiving module is further configured to receive second indication information; wherein the second indication information is used to indicate whether the first access network device has received the first data; The processing module is configured to determine second data according to the first indication information and the second indication information; the second data includes data in the first data that is not received by the first access network device; The sending module is used to send the second data to the relay terminal or the second access network device.

38. The communication device according to claim 37, wherein: The second indication information comes from the relay terminal or the first access network device.

39. The communication device according to any one of claims 37-38, characterized in that The first indication information is included in a radio link control RLC control protocol data unit PDU; wherein the first indication information includes a first identifier of the first data and reception confirmation information of the first data; the reception confirmation information of the first data is used to indicate whether the relay terminal has successfully received each data in the first data; The second indication information is included in a Packet Data Convergence Protocol (PDCP) control PDU; wherein the second indication information includes a second identifier of the first data; the second indication information is used to indicate whether the first access network device has successfully received each data in the first data.

40. The communication device according to claim 39, wherein: The first identifier includes the serial number of the first data; the second identifier includes the count COUNT value or the serial number SN of the first data.

41. The communication device according to any one of claims 37-38, characterized in that The receiving module is also used to receive configuration information of the first function from the first access network device; wherein, the first function is used by the remote terminal to determine third indication information based on the first indication information and / or the second indication information; the third indication information is used to indicate the data in the first data that is successfully received by the first access network device.

42. The communication device according to claim 41, wherein: The processing module is further configured to determine the second data according to the third indication information.

43. A communication device, characterized in that The communication device includes a receiving module, a processing module and a sending module; The receiving module is configured to receive first indication information from the relay terminal; wherein the first indication information is used to indicate that the relay terminal has received first data, and the first data is data sent to the remote terminal; The receiving module is further configured to receive second indication information; wherein the second indication information is configured to indicate whether the remote terminal has received the first data; The processing module is configured to determine second data according to the first indication information and the second indication information, wherein the second data includes data in the first data that is not received by the remote terminal; The sending module is used to send the second data to the relay terminal or the remote terminal.

44. The communication device according to claim 43, wherein: The second indication information comes from the relay terminal or the remote terminal.

45. The communication device according to any one of claims 43-44, characterized in that The first indication information is included in the RLC control PDU; wherein the first indication information includes a first identifier of the first data and reception confirmation information of the first data; the reception confirmation information of the first data is used to indicate whether the relay terminal has successfully received the data corresponding to each count value or sequence number in the first data; The second indication information is included in the PDCP control PDU; wherein, the second indication information includes a second identifier of the first data.

46. ​​The communication device according to claim 45, characterized in that The first identifier includes the serial number of the first data; the second identifier includes the count COUNT value or the serial number SN of the first data.

47. The communication device according to any one of claims 43-44, characterized in that The sending module is further used to send configuration information of a second function to the relay terminal; wherein the second function is used by the relay terminal to send the second indication information to the first access network device.

48. The communication device according to claim 47, characterized in that The processing module is further used to determine third indication information based on the first indication information and / or the second indication information; wherein the third indication information is used to indicate the data in the first data that is successfully received by the first access network device.

49. The communication device according to claim 48, characterized in that The processing module is further configured to determine the second data according to the third indication information.

50. A communication device, characterized in that The communication device includes a sending module; The sending module is configured to send first indication information to the remote terminal; wherein the first indication information is used to indicate that the relay terminal has received first data, and the first data is data sent to the first access network device; The sending module is further configured to send second indication information to the remote terminal; wherein the second indication information is used to indicate whether the first access network device has received the first data; The sending module is further used to send second data to the second access network device; wherein the second data is determined based on the first indication information and the second indication information, and the second data includes data in the first data that is not received by the first access network device.

51. The communication device according to claim 50, characterized in that The communication device further includes a receiving module; The receiving module is configured to receive the second indication information from the first access network device; The sending module is further used to send the second indication information from the first access network device to the remote terminal.

52. The communication device according to claim 50 or 51, characterized in that The first indication information is included in the RLC control PDU; wherein the first indication information includes a first identifier of the first data and reception confirmation information of the first data; the reception confirmation information of the first data is used to indicate whether the relay terminal has successfully received each data in the first data; The second indication information is included in the PDCP control PDU; wherein, the second indication information includes a second identifier of the first data; the second indication information is used to indicate whether the first access network device has successfully received each data in the first data.

53. The communication device according to claim 52, characterized in that The first identifier includes the serial number of the first data; the second identifier includes the count COUNT value or the serial number SN of the first data.

54. The communication device according to any one of claims 50-51, characterized in that The receiving module is further used to receive configuration information of a third function from the first access network device; wherein the third function is used by the relay terminal to send the first indication information to the remote terminal.

55. A communication device, characterized in that The communication device includes a sending module; The sending module is configured to send first indication information to the first access network device; wherein the first indication information is used to indicate that the relay terminal has received first data, and the first data is data sent to the remote terminal; The sending module is further configured to send second indication information to the first access network device; wherein the second data is determined based on the first indication information and the second indication information, and the second indication information is used to indicate whether the remote terminal has received the first data; The sending module is further configured to send second data to the remote terminal; wherein the second data includes data in the first data that the remote terminal has not received.

56. The communication device according to claim 55, characterized in that The communication device further includes a receiving module; The receiving module is configured to receive the second indication information from the remote terminal; The sending module is further used to send the second indication information from the remote terminal to the first access network device.

57. The communication device according to claim 55 or 56, characterized in that The first indication information is included in the RLC control PDU; wherein the first indication information includes a first identifier of the first data and reception confirmation information of the first data; the reception confirmation information of the first data is used to indicate whether the relay terminal has successfully received each data in the first data; The second indication information is included in the PDCP control PDU; wherein, the second indication information includes a second identifier of the first data; the second indication information is used to indicate whether the first access network device has successfully received each data in the first data.

58. The communication device according to claim 57, characterized in that The first identifier includes the serial number of the first data; the second identifier includes the count COUNT value or the serial number SN of the first data.

59. The communication device according to any one of claims 55-56, characterized in that The receiving module is further used to receive configuration information of a second function from the first access network device; wherein the second function is used by the relay terminal to send the first indication information to the first access network device.

60. A communication device, characterized in that The communication device includes a sending module and a receiving module; The sending module is configured to send second indication information to the remote terminal; wherein the second indication information is used to indicate whether the first access network device has received the first data, and the first data is data sent to the first access network device; The receiving module is used to receive second data from the relay terminal or the remote terminal; wherein the second data is determined according to the second indication information, and the second data includes data in the first data that is not received by the first access network device.

61. The communication device according to claim 60, characterized in that The second indication information is included in the PDCP control PDU; wherein, the second indication information includes a second identifier of the first data; the second indication information is used to indicate whether the first access network device has successfully received each data in the first data.

62. The communication device according to claim 61, characterized in that The second identifier includes a COUNT value or SN of the first data.

63. The communication device according to any one of claims 60 to 62, characterized in that: The sending module is also used to send configuration information of the first function to the remote terminal; wherein, the first function is used by the remote terminal to determine third indication information based on the first indication information and / or the second indication information; the third indication information is used to indicate the data in the first data that is successfully received by the first access network device.

64. A communication device, characterized in that The communication device includes a sending module and a receiving module; The sending module is configured to send second indication information to the first access network device; wherein the second indication information is used to indicate whether the remote terminal has received the first data, the first data being data sent to the remote terminal; The receiving module is used to receive second data sent by the relay terminal or the second access network device; wherein the second data is determined according to the second indication information, and the second data includes data in the first data that is not received by the remote terminal.

65. The communication device according to claim 64, characterized in that The second indication information is included in the PDCP control PDU; wherein, the second indication information includes a second identifier of the first data; the second indication information is used to indicate whether the first access network device has successfully received each data in the first data.

66. The communication device according to claim 65, characterized in that The second identifier includes a COUNT value or SN of the first data.

67. A communication device, characterized in that The communication device includes: a processor coupled to a memory; The memory is used to store computer programs; The processor is configured to execute the computer program stored in the memory, so that the communication device executes the communication method according to any one of claims 1 to 36.

68. A computer-readable storage medium, characterized in that The computer-readable storage medium includes a computer program or instructions, and when the computer program or instructions are executed on a computer, the computer is caused to perform the communication method according to any one of claims 1 to 36.

69. A computer program product, characterized in that The computer program product comprises: a computer program or instructions, and when the computer program or instructions are run on a computer, the computer is caused to perform the communication method according to any one of claims 1 to 36.

70. A communication chip, characterized in that: Instructions are stored therein, and when the chip runs on a communication device, the method according to any one of claims 1 to 36 is implemented.

71. A communication system, characterized in that The communication system is configured to execute the communication method according to any one of claims 1 to 36.

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