Serial number indication, determination method and device

Abstract

This application discloses a method and apparatus for indicating and determining a sequence number. The indicating method includes: a first network device sending first indication information to a first terminal device, instructing the first terminal device to report a first sequence number in an RLC entity. The first terminal device sends the first sequence number in the RLC entity according to the first indication information; wherein the first sequence number indicates the starting sequence number in the RLC entity of the first network device. The first network device determines the starting sequence number in the RLC entity of the first network device based on the first sequence number. The determining method includes: the network device determining a first data packet; determining the RLC sequence number corresponding to the first data packet based on the PDCP sequence number corresponding to the first data packet; adding the RLC sequence number to the RLC header of the first data packet; and sending the first data packet. The terminal device receives the first data packet. Using the above indicating and determining scheme improves the reliability of communication.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a method and apparatus for indicating and determining a serial number. Background Technology

[0002] In wireless communication, radio link control (RLC) sits between the media access control (MAC) layer and the packet data convergence protocol (PDCP) layer. For example... Figure 1 The diagram illustrates the protocol stack structure in an uplink transmission scenario (data transmission from the terminal to the next-generation node B (gNB)). Data transmission proceeds in the direction indicated by the arrows. Downlink transmission proceeds in the opposite direction to uplink transmission, sequentially passing through the protocol stack. Each layer processes the data and adds its corresponding header. For example, at the PDCP layer, the data undergoes security processing and header compression before being appended with a PDCP header; at the RLC layer, it undergoes processing before being appended with an RLC header, and so on. When service data units (SDUs) of each protocol stack are segmented during transmission, the header of each protocol layer typically carries the corresponding sequence number (SN) to facilitate processing of the data packets by the receiving layer based on the SN.

[0003] In some application scenarios, such as industrial settings, the reliability requirements for service transmission are high, which in turn places high demands on the reliability of the equipment itself. If the equipment fails, service transmission cannot be guaranteed. Currently, one solution employed is the A / B network solution, such as... Figure 2 The diagram of the A / B network structure illustrates the idea of ​​deploying two sets of access network equipment (NG-RAN1 and NG-RAN2), referred to as the A-network equipment and the B-network equipment, respectively. When the A-network equipment fails, the B-network equipment is activated to continue service transmission. However, the A / B network requires the deployment of two communication frequencies, which is a waste of scarce frequency resources. Furthermore, the service switching time between the two sets of equipment is long and results in significant data packet loss, reducing communication reliability. Summary of the Invention

[0004] This application provides a method and apparatus for indicating and determining serial numbers, so as to accurately determine the serial number in an RLC entity and improve the reliability of communication.

[0005] In a first aspect, a method for indicating a sequence number is provided, comprising: a first terminal device receiving first indication information from a first network device, the first indication information being used to instruct the first terminal device to report a first sequence number in a Radio Link Control (RLC) entity; and the first terminal device sending the first sequence number in the RLC entity to the first network device according to the first indication information; wherein the first sequence number is used to indicate a starting sequence number in the RLC entity of the first network device. In this aspect, the first terminal device reports the first sequence number in the RLC entity according to the instruction of the first network device, and the first network device can determine the starting sequence number in its own RLC entity based on the first sequence number, such that the sequence numbers of the RLC entities in the first network device and the first terminal device are aligned. Therefore, when the first terminal device receives data packets sent by the first network device, it can accurately merge them based on the aligned sequence numbers, thereby improving the reliability of communication.

[0006] In conjunction with the first aspect, in one possible implementation, a second network device malfunctions before the first terminal device receives the first indication information from the first network device. The second network device is the network device that communicated with the first terminal device before the malfunction occurred. In this implementation, when the second network device malfunctions and the first network device takes over the services of the second network device, it instructs the first terminal device to report the first sequence number in the RLC entity.

[0007] In conjunction with the first aspect, in another possible implementation, the first serial number is the maximum value among the serial numbers of the RLC entity of the first terminal device. In this implementation, the first serial number is the maximum value among the serial numbers of the RLC entity of the first terminal device, so that the first network device starts setting from the next serial number after the maximum value, thereby enabling the serial numbers of the first network device to be aligned with those of the RLC entity in the first terminal device.

[0008] In a second aspect, a method for indicating a serial number is provided, comprising: a first network device sending first indication information to a first terminal device, the first indication information being used to instruct the first terminal device to report a first serial number in a Radio Link Control (RLC) entity; the first network device receiving the first serial number from the RLC entity of the first terminal device; and the first network device determining a starting serial number in its RLC entity based on the first serial number.

[0009] In conjunction with the second aspect, in one possible implementation, before the first network device sends the first indication information to the first terminal device, the method further includes: the first network device detecting a failure in the second network device, wherein the second network device is a network device that was communicating with the first terminal device before the failure occurred.

[0010] In conjunction with the second aspect, in yet another possible implementation, the first serial number is the maximum value among the serial numbers of the RLC entity of the first terminal device.

[0011] Thirdly, a method for indicating a sequence number is provided, comprising: a first network device receiving first information from a second network device, the first information including a second sequence number; and the first network device determining a starting sequence number in the RLC entity of the first network device based on the second sequence number. In this aspect, when the second network device is not experiencing a fault, it sends the second sequence number to the first network device, and the first network device determines the starting sequence number in the RLC entity of the first network device based on the second sequence number. Therefore, when the second network device fails and the first network device takes over, the sequence numbers of the RLC entities in the first network device and the first terminal device can be aligned. When the first terminal device receives data packets sent by the first network device, it can accurately merge them based on the aligned sequence numbers, improving the reliability of communication.

[0012] In conjunction with the third aspect, in one possible implementation, the second serial number is the maximum value among the serial numbers of the RLC entity of the second network device. In this implementation, since the second serial number is the maximum value among the serial numbers of the RLC entity of the second network device, after the first network device takes over the second network device, the first network device starts setting from the next serial number after the maximum value in the serial number, thereby enabling the serial numbers of the first network device to be aligned with those of the RLC entity in the first terminal device.

[0013] Fourthly, a method for indicating a serial number is provided, comprising: a second network device sending first information to a first network device, the first information including a second serial number, the second serial number being used to indicate a start serial number in the RLC entity of the first network device.

[0014] In conjunction with the fourth aspect, in one possible implementation, the second network device sends first information to the first network device, including: sending the first information to the first network device when the maximum sequence number in the RLC entity of the second network device is updated. In this implementation, the second network device sends the first information to the first network device whenever the maximum sequence number in the RLC entity of the second network device is updated, thereby enabling the first network device to obtain the second sequence number in a timely manner, allowing the first network device to accurately align with the sequence number of the RLC entity in the first terminal device based on the latest second sequence number.

[0015] Fifthly, a method for indicating a sequence number is provided, comprising: a first terminal device periodically sending second information to a first network device, the second information including a first sequence number in an RLC entity, the first sequence number being used to indicate a starting sequence number in the RLC entity of the first network device. In this aspect, the first terminal device periodically sends the first sequence number in the RLC entity to the first network device, and the first network device can determine the starting sequence number in its RLC entity based on the first sequence number, such that the sequence numbers of the RLC entities in the first network device and the first terminal device are aligned. Therefore, when the first terminal device receives data packets sent by the first network device, it can accurately merge them based on the aligned sequence numbers, improving the reliability of communication.

[0016] In conjunction with the fifth aspect, in one possible implementation, the method further includes: the first terminal device starting a timer; after the timer expires, the first terminal device sending the second information to the first network device; and the first terminal device restarting the timer. In this implementation, by setting a timer, the first terminal device can periodically and promptly send the first sequence number in the RLC entity to the first network device.

[0017] In conjunction with the fifth aspect, in another possible implementation, the first serial number is the maximum value among the serial numbers of the RLC entity of the first terminal device. In this implementation, the first serial number is the maximum value among the serial numbers of the RLC entity of the first terminal device, so that the first network device starts setting from the next serial number after the maximum value, thereby enabling the serial numbers of the first network device to be aligned with those of the RLC entity in the first terminal device.

[0018] A sixth aspect provides a method for indicating a serial number, comprising: a first network device receiving second information periodically sent by a first terminal device, the second information including a first serial number in an RLC entity; and the first network device determining a starting serial number in its RLC entity based on the first serial number.

[0019] In conjunction with the sixth aspect, in one possible implementation, the first serial number is the maximum value among the serial numbers of the RLC entity of the first terminal device.

[0020] A seventh aspect provides a method for indicating sequence numbers, comprising: a first terminal device receiving third indication information from a first network device, the third indication information being used to indicate RLC entity reconstruction or RLC entity reset; and the first terminal device performing at least one of the following operations based on the third indication information: RLC variable initialization, RLC timer initialization, RLC entity buffer clearing, or data packet discarding. In this aspect, the first terminal device performs RLC variable initialization, RLC entity buffer clearing, or data packet discarding based on the indication information from the first network device, thereby aligning the sequence numbers of the first terminal device with those of the RLC entities in the first network device. This allows the first terminal device to accurately merge data packets received from the first network device based on the aligned sequence numbers, improving communication reliability.

[0021] In conjunction with the seventh aspect, in one possible implementation, the third indication information is any of the following: RRC signaling, PDCP control PDU, RLC control PDU, MAC CE, DCI.

[0022] In conjunction with the seventh aspect, in another possible implementation, a second network device malfunctions before the first terminal device receives the third indication information from the first network device, the second network device being the network device that communicated with the first terminal device before the malfunction occurred.

[0023] Eighthly, a method for sending indication information is provided, comprising: a first network device sending third indication information to a first terminal device, the third indication information being used to indicate RLC entity reconstruction or RLC entity reset.

[0024] In conjunction with the eighth aspect, in one possible implementation, before the first network device sends the third indication information to the first terminal device, the method further includes: the first network device detecting a failure in the second network device, the second network device being the network device that communicated with the first terminal device before the failure occurred.

[0025] A ninth aspect provides a method for determining a sequence number, comprising: a network device determining a first data packet; the network device determining a Radio Link Control (RLC) sequence number corresponding to the first data packet based on a Packet Data Convergence Protocol (PDCP) sequence number corresponding to the first data packet; the network device adding the RLC sequence number to an RLC header corresponding to the first data packet; and the network device sending the first data packet. In this aspect, the network device determines the RLC sequence number corresponding to the first data packet based on the PDCP sequence number, thereby ensuring consistent processing of sequence numbers by the RLC layer and PDCP layer of the network device. In the event of a network device failure, the RLC layer of the terminal device will not receive a first data packet corresponding to a duplicate sequence number, but will discard the first data packet, thus improving communication reliability.

[0026] In conjunction with aspect nine, in one possible implementation, the network device determines the RLC sequence number corresponding to the first data packet based on the PDCP sequence number corresponding to the first data packet, including: the RLC sequence number is equal to the PDCP sequence number, or the offset between the RLC sequence number and the PDCP sequence number is N, where N is an integer. In this implementation, both the network device and the terminal device determine the RLC sequence number corresponding to the first data packet based on the PDCP sequence number corresponding to the first data packet. This prevents the terminal device from mistaking a first data packet with a duplicate sequence number for one and discarding it, thus improving communication reliability.

[0027] In conjunction with the ninth aspect, in another possible implementation, the method further includes: the network device sending a second indication message to the terminal device, the second indication message indicating that a data packet corresponding to at least one RLC sequence number cannot be sent or instructing the terminal device to ignore the reception of the data packet corresponding to the at least one RLC sequence number. In this implementation, when the upper layer of the RLC layer loses a packet, the network device's RLC layer will also skip a sequence number when setting the sequence number of the RLC entity. Therefore, in AM RLC mode, the terminal device will also detect the loss of a data packet corresponding to a sequence number. At this time, the terminal device will send a feedback message to the network device requesting retransmission. Furthermore, if the lost data packet is not received, the terminal device cannot continue receiving data packets. The network device knows that the data packet corresponding to the sequence number has been lost and cannot be successfully sent. At this time, the network device sends the second indication message to the terminal device, indicating that a data packet corresponding to at least one RLC sequence number cannot be sent or instructing the terminal device to ignore the reception of the data packet corresponding to the at least one RLC sequence number. The terminal device, based on the second indication message, ignores the reception gap caused by the loss of the data packet corresponding to the at least one RLC sequence number, thereby allowing it to move its reception window forward and continue receiving subsequent data packets.

[0028] In conjunction with the ninth aspect, in yet another possible implementation, the second indication information is contained in the RLC control protocol data unit (PDU); or the second indication information is contained in the RLC data PDU, wherein the RLC data PDU contains only a header.

[0029] In a tenth aspect, a method for determining a sequence number is provided, comprising: a terminal device receiving a first data packet from a network device, wherein the RLC header of the first data packet includes an RLC sequence number, and the RLC sequence number corresponding to the first data packet is determined based on the Packet Data Convergence Protocol (PDCP) sequence number corresponding to the first data packet.

[0030] In conjunction with the tenth aspect, in one possible implementation, the RLC sequence number corresponding to the first data packet is equal to the PDCP sequence number corresponding to the first data packet, or the offset between the RLC sequence number corresponding to the first data packet and the PDCP sequence number corresponding to the first data packet is N, where N is an integer.

[0031] In conjunction with the tenth aspect, in another possible implementation, the method further includes: the terminal device receiving second indication information from the network device, the second indication information being used to indicate that a data packet corresponding to at least one RLC sequence number cannot be sent or to indicate that the terminal device ignores the reception of the data packet corresponding to the at least one RLC sequence number; and the first terminal device determining, based on the second indication information, to ignore the data packet corresponding to the at least one RLC sequence number that cannot be sent and continuing to slide the reception window backward.

[0032] In conjunction with the tenth aspect, in yet another possible implementation, the second indication information is contained in an RLC control protocol data unit (PDU); or the second indication information is contained in an RLC data PDU, wherein the RLC data PDU contains only a header.

[0033] Eleventhly, a serial number indicating device is provided for performing the method in the first aspect or any possible implementation thereof. The serial number indicating device may be a terminal device in the first aspect or any possible implementation thereof, or a module applied in a terminal device, such as a chip or chip system. The serial number indicating device includes modules, units, or means corresponding to the above-described method, which may be implemented in hardware, software, or by hardware executing corresponding software implementations. The hardware or software includes at least one module or unit corresponding to the above-described function.

[0034] In conjunction with the eleventh aspect above, in one possible implementation, the sequence number indication device includes: a receiving unit and a sending unit; wherein, the receiving unit is configured to receive first indication information from a first network device, the first indication information being used to instruct the first terminal device to report a first sequence number in a Radio Link Control (RLC) entity; and the sending unit is configured to send the first sequence number in the RLC entity to the first network device according to the first indication information; wherein, the first sequence number is used to indicate a starting sequence number in the RLC entity of the first network device.

[0035] In conjunction with the eleventh aspect above, in another possible implementation, the serial number indication device includes: an input interface, an output interface, and a processing circuit; wherein, the input interface is used to receive first indication information from a first network device, the first indication information being used to instruct the first terminal device to report a first serial number in a Radio Link Control (RLC) entity; and the output interface is used to send the first serial number in the RLC entity to the first network device according to the first indication information; wherein, the first serial number is used to indicate the starting serial number in the RLC entity of the first network device.

[0036] For example, the serial number indicating device further includes a memory coupled to the at least one processor for executing program instructions stored in the memory to cause the serial number indicating device to perform the methods in the first aspect or any possible implementation thereof.

[0037] In one possible implementation, the memory is used to store program instructions and data. The memory is coupled to the at least one processor, which can invoke and execute the program instructions stored in the memory to cause the indication device of the serial number to perform the method described in the first aspect or any possible implementation thereof.

[0038] For example, the serial number indicating device further includes a communication interface for communicating with other devices. When the serial number indicating device is a terminal, the communication interface is a transceiver, an input / output interface, or a circuit, etc.

[0039] In one possible design, the serial number indicating device includes: at least one processor and a communication interface for executing the methods described in the first aspect or any possible implementation thereof, specifically including: the at least one processor communicating with an external source using the communication interface; the at least one processor running a computer program that causes the serial number indicating device to execute the methods described in the first aspect or any possible implementation thereof. It is understood that the external source may be an object other than the processor, or an object other than the serial number indicating device.

[0040] In another possible design, the serial number indicator is a chip or chip system. The communication interface can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip or chip system. The processor can also be represented as a processing circuit or logic circuit.

[0041] The technical effects of any design method in the eleventh aspect can be seen in the technical effects of different design methods in the first aspect above, and will not be repeated here.

[0042] In a twelfth aspect, a serial number indicating device is provided for performing the methods of the second aspect or any possible implementation thereof. The serial number indicating device may be a first network device in the second aspect or any possible implementation thereof, or a module applied in the first network device, such as a chip or chip system. The serial number indicating device includes modules, units, or means corresponding to the methods described above, which may be implemented in hardware, software, or by hardware executing corresponding software implementations. The hardware or software includes at least one module or unit corresponding to the functions described above.

[0043] In conjunction with the twelfth aspect above, in one possible implementation, the sequence number indication device includes: a sending unit, a receiving unit, and a processing unit; wherein, the sending unit is configured to send first indication information to a first terminal device, the first indication information being configured to instruct the first terminal device to report a first sequence number in a Radio Link Control (RLC) entity; the receiving unit is configured to receive the first sequence number from the RLC entity of the first terminal device; and the processing unit is configured to determine a starting sequence number in the RLC entity of the first network device based on the first sequence number.

[0044] Optionally, the processing unit is further configured to detect a fault in the second network device, which was the network device that communicated with the first terminal device before the fault occurred.

[0045] In conjunction with the twelfth aspect above, in another possible implementation, the serial number indication device includes: an input interface, an output interface, and a processing circuit; the output interface is used to send first indication information to a first terminal device, the first indication information being used to instruct the first terminal device to report a first serial number in a Radio Link Control (RLC) entity; the input interface is used to receive the first serial number from the RLC entity of the first terminal device; and the processing circuit is used to determine a starting serial number in the RLC entity of the first network device based on the first serial number.

[0046] Optionally, the processing circuit is further configured to detect a fault in the second network device, which was communicating with the first terminal device before the fault occurred.

[0047] For example, the serial number indicating device further includes a memory coupled to the at least one processor for executing program instructions stored in the memory to cause the serial number indicating device to perform the methods in the second aspect or any possible implementation thereof.

[0048] In one possible implementation, the memory is used to store program instructions and data. The memory is coupled to the at least one processor, which can invoke and execute the program instructions stored in the memory to cause the indication device of the serial number to perform the methods of the second aspect or any possible implementation thereof.

[0049] For example, the serial number indicating device further includes a communication interface for communicating with other devices. When the serial number indicating device is an access network device, the communication interface is a transceiver, an input / output interface, or a circuit, etc.

[0050] In one possible design, the serial number indicating device includes: at least one processor and a communication interface for executing the methods described in the second aspect or any possible implementation thereof, specifically including: the at least one processor communicating with an external source using the communication interface; the at least one processor running a computer program that causes the serial number indicating device to execute the methods described in the second aspect or any possible implementation thereof. It is understood that the external source may be an object other than the processor, or an object other than the serial number indicating device.

[0051] In another possible design, the serial number indicator is a chip or chip system. The communication interface can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip or chip system. The processor can also be represented as a processing circuit or logic circuit.

[0052] The technical effects of any design method in the twelfth aspect can be found in the technical effects of different design methods in the second aspect above, and will not be repeated here.

[0053] In a thirteenth aspect, a serial number indicating device is provided for performing the methods described in the third aspect or any possible implementation thereof. The serial number indicating device may be a terminal device described in the third aspect or any possible implementation thereof, or a module applied in a terminal device, such as a chip or chip system. The serial number indicating device includes modules, units, or means corresponding to the described methods, which may be implemented in hardware, software, or by hardware executing corresponding software implementations. The hardware or software includes at least one module or unit corresponding to the described functions.

[0054] In conjunction with the thirteenth aspect above, in one possible implementation, the serial number indicating device includes: a receiving unit and a processing unit; wherein the receiving unit is configured to receive first information from a second network device, the first information including a second serial number; and the processing unit is configured to determine a starting serial number in the RLC entity of the first network device based on the second serial number.

[0055] In conjunction with the thirteenth aspect above, in another possible implementation, the serial number indicating device includes: an input interface, an output interface, and a processing circuit; wherein the input interface is configured to receive first information from the second network device, the first information including a second serial number; and the processing circuit is configured to determine a starting serial number in the RLC entity of the first network device based on the second serial number.

[0056] For example, the serial number indicating device further includes a memory coupled to the at least one processor for executing program instructions stored in the memory to cause the serial number indicating device to perform the methods described in the third aspect or any possible implementation thereof.

[0057] In one possible implementation, the memory is used to store program instructions and data. The memory is coupled to the at least one processor, which can invoke and execute the program instructions stored in the memory to cause the indication device of the serial number to perform the methods described in the third aspect or any possible implementation thereof.

[0058] For example, the serial number indicating device further includes a communication interface for communicating with other devices. When the serial number indicating device is a terminal, the communication interface is a transceiver, an input / output interface, or a circuit, etc.

[0059] In one possible design, the serial number indicating device includes: at least one processor and a communication interface for executing the methods described in the third aspect or any possible implementation thereof, specifically including: the at least one processor communicating with an external source using the communication interface; the at least one processor running a computer program that causes the serial number indicating device to execute the methods described in the third aspect or any possible implementation thereof. It is understood that the external source may be an object other than the processor, or an object other than the serial number indicating device.

[0060] In another possible design, the serial number indicator is a chip or chip system. The communication interface can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip or chip system. The processor can also be represented as a processing circuit or logic circuit.

[0061] The technical effects of any design method in aspect thirteen can be found in the technical effects of different design methods in aspect three above, and will not be repeated here.

[0062] In a fourteenth aspect, a serial number indicating device is provided for performing the methods of the fourth aspect or any possible implementation thereof. The serial number indicating device may be a first network device in the fourth aspect or any possible implementation thereof, or a module applied in the first network device, such as a chip or chip system. The serial number indicating device includes modules, units, or means that implement the methods described above. These modules, units, or means may be implemented in hardware, software, or by hardware executing corresponding software implementations. The hardware or software includes at least one module or unit corresponding to the functions described above.

[0063] In conjunction with the fourteenth aspect above, in one possible implementation, the serial number indicating device includes: a sending unit; wherein the sending unit is configured to send first information to a first network device, the first information including a second serial number, the second serial number being used to indicate the starting serial number in the RLC entity of the first network device.

[0064] Optionally, the sending unit is specifically used to send the first information to the first network device when the maximum sequence number in the RLC entity of the device is updated.

[0065] In conjunction with the fourteenth aspect above, in another possible implementation, the serial number indicating device includes: an input interface, an output interface, and processing circuitry; the output interface is used to send first information to a first network device, the first information including a second serial number, the second serial number being used to indicate the starting serial number in the RLC entity of the first network device.

[0066] Optionally, the output interface is specifically used to send the first information to the first network device when the maximum sequence number in the RLC entity of the device is updated.

[0067] For example, the serial number indicating device further includes a memory coupled to the at least one processor for executing program instructions stored in the memory to cause the serial number indicating device to perform the methods in the fourth aspect or any possible implementation of the fourth aspect.

[0068] In one possible implementation, the memory is used to store program instructions and data. The memory is coupled to the at least one processor, which can invoke and execute the program instructions stored in the memory to cause the indication device of the serial number to perform the methods described in the fourth aspect or any possible implementation thereof.

[0069] For example, the serial number indicating device further includes a communication interface for communicating with other devices. When the serial number indicating device is an access network device, the communication interface is a transceiver, an input / output interface, or a circuit, etc.

[0070] In one possible design, the serial number indicating device includes: at least one processor and a communication interface for executing the methods described in the fourth aspect or any possible implementation thereof, specifically including: the at least one processor communicating with an external source using the communication interface; the at least one processor running a computer program that causes the serial number indicating device to execute the methods described in the fourth aspect or any possible implementation thereof. It is understood that the external source may be an object other than the processor, or an object other than the serial number indicating device.

[0071] In another possible design, the serial number indicator is a chip or chip system. The communication interface can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip or chip system. The processor can also be represented as a processing circuit or logic circuit.

[0072] The technical effects of any design method in aspect fourteen can be found in the technical effects of different design methods in aspect four above, and will not be repeated here.

[0073] In a fifteenth aspect, a serial number indicating device is provided for performing the methods of the fifth aspect or any possible implementation thereof. The serial number indicating device may be a terminal device in the fifth aspect or any possible implementation thereof, or a module applied in a terminal device, such as a chip or chip system. The serial number indicating device includes modules, units, or means corresponding to the above-described methods, which may be implemented in hardware, software, or by hardware executing corresponding software implementations. The hardware or software includes at least one module or unit corresponding to the above-described functions.

[0074] In conjunction with the fifteenth aspect above, in one possible implementation, the serial number indicating device includes: a sending unit; wherein the sending unit is configured to periodically send second information to the first network device, the second information including a first serial number in an RLC entity, the first serial number being used to indicate a start serial number in the RLC entity of the first network device.

[0075] Optionally, the device further includes: a processing unit; wherein the processing unit is configured to start a timer; the sending unit is specifically configured to send the second information to the first network device after the timer expires; and the processing unit is further configured to restart the timer.

[0076] In conjunction with the fifteenth aspect above, in another possible implementation, the serial number indicating device includes: an input interface, an output interface, and a processing circuit; wherein the output interface is used to periodically send second information to the first network device, the second information including a first serial number in an RLC entity, the first serial number being used to indicate a starting serial number in the RLC entity of the first network device.

[0077] Optionally, the processing circuit is used to start a timer; the output interface is specifically used to send the second information to the first network device after the timer expires; and the processing circuit is also used to restart the timer.

[0078] For example, the serial number indicating device further includes a memory coupled to the at least one processor for executing program instructions stored in the memory to cause the serial number indicating device to perform the methods in the fifth aspect or any possible implementation thereof.

[0079] In one possible implementation, the memory is used to store program instructions and data. The memory is coupled to the at least one processor, which can invoke and execute the program instructions stored in the memory to cause the indication device of the serial number to perform the methods described in the fifth aspect or any possible implementation thereof.

[0080] For example, the serial number indicating device further includes a communication interface for communicating with other devices. When the serial number indicating device is a terminal, the communication interface is a transceiver, an input / output interface, or a circuit, etc.

[0081] In one possible design, the serial number indicating device includes: at least one processor and a communication interface for executing the methods described in the fifth aspect or any possible implementation thereof, specifically including: the at least one processor communicating with an external source using the communication interface; the at least one processor running a computer program that causes the serial number indicating device to execute the methods described in the fifth aspect or any possible implementation thereof. It is understood that the external source may be an object other than the processor, or an object other than the serial number indicating device.

[0082] In another possible design, the serial number indicator is a chip or chip system. The communication interface can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip or chip system. The processor can also be represented as a processing circuit or logic circuit.

[0083] The technical effects of any design method in aspect 15 can be found in the technical effects of different design methods in aspect 5 above, and will not be repeated here.

[0084] In a sixteenth aspect, a serial number indicating device is provided for performing the methods of the sixth aspect or any possible implementation thereof. The serial number indicating device may be a first network device in the sixth aspect or any possible implementation thereof, or a module applied in the first network device, such as a chip or chip system. The serial number indicating device includes modules, units, or means that implement the methods described above, which may be implemented in hardware, software, or by hardware executing corresponding software implementations. The hardware or software includes at least one module or unit corresponding to the functions described above.

[0085] In conjunction with the sixteenth aspect above, in one possible implementation, the serial number indicating device includes: a receiving unit and a processing unit; wherein the receiving unit is configured to receive second information periodically transmitted by the first terminal device, the second information including a first serial number in an RLC entity; and the processing unit is configured to determine a starting serial number in the RLC entity of the first network device based on the first serial number.

[0086] In conjunction with the sixteenth aspect above, in another possible implementation, the serial number indicating device includes: an input interface, an output interface, and a processing circuit; wherein the input interface is used to receive second information periodically sent by the first terminal device, the second information including a first serial number in the RLC entity; and the processing circuit is used to determine a starting serial number in the RLC entity of the first network device based on the first serial number.

[0087] For example, the serial number indicating device further includes a memory coupled to the at least one processor for executing program instructions stored in the memory to cause the serial number indicating device to perform the methods in the sixth aspect or any possible implementation thereof.

[0088] In one possible implementation, the memory is used to store program instructions and data. The memory is coupled to the at least one processor, which can invoke and execute the program instructions stored in the memory to cause the indication device of the serial number to perform the methods described in the sixth aspect or any possible implementation thereof.

[0089] For example, the serial number indicating device further includes a communication interface for communicating with other devices. When the serial number indicating device is an access network device, the communication interface is a transceiver, an input / output interface, or a circuit, etc.

[0090] In one possible design, the serial number indicating device includes: at least one processor and a communication interface for executing the methods described in the sixth aspect or any possible implementation thereof, specifically including: the at least one processor communicating with an external source using the communication interface; the at least one processor running a computer program that causes the serial number indicating device to execute the methods described in the sixth aspect or any possible implementation thereof. It is understood that the external source may be an object other than the processor, or an object other than the serial number indicating device.

[0091] In another possible design, the serial number indicator is a chip or chip system. The communication interface can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip or chip system. The processor can also be represented as a processing circuit or logic circuit.

[0092] The technical effects of any design method in the sixteenth aspect can be found in the technical effects of different design methods in the sixth aspect above, and will not be repeated here.

[0093] In a seventeenth aspect, a serial number indicating device is provided for performing the methods described in the seventh aspect or any possible implementation thereof. The serial number indicating device may be a terminal device described in the seventh aspect or any possible implementation thereof, or a module applied in a terminal device, such as a chip or chip system. The serial number indicating device includes modules, units, or means that implement the methods described above. These modules, units, or means may be implemented in hardware, software, or by hardware executing corresponding software implementations. The hardware or software includes at least one module or unit corresponding to the functions described above.

[0094] In conjunction with the seventeenth aspect above, in one possible implementation, the sequence number indication device includes: a receiving unit and a processing unit; wherein the receiving unit is configured to receive third indication information from a first network device, the third indication information being used to indicate RLC entity reconstruction or RLC entity reset; and the processing unit is configured to perform at least one of the following operations based on the third indication information: RLC variable initialization, RLC timer initialization, RLC entity buffer clearing, or packet dropping.

[0095] In conjunction with the seventeenth aspect above, in another possible implementation, the sequence number indication device includes: an input interface, an output interface, and a processing circuit; wherein the input interface is configured to receive third indication information from a first network device, the third indication information being configured to indicate RLC entity reconstruction or RLC entity reset; and the processing circuit is configured to perform at least one of the following operations based on the third indication information: RLC variable initialization, RLC entity buffer clearing, or packet dropping.

[0096] For example, the serial number indicating device further includes a memory coupled to the at least one processor for executing program instructions stored in the memory to cause the serial number indicating device to perform the methods in the seventh aspect or any possible implementation thereof.

[0097] In one possible implementation, the memory is used to store program instructions and data. The memory is coupled to the at least one processor, which can invoke and execute the program instructions stored in the memory to cause the indication device of the serial number to perform the methods in the seventh aspect or any possible implementation of the seventh aspect.

[0098] For example, the serial number indicating device further includes a communication interface for communicating with other devices. When the serial number indicating device is a terminal, the communication interface is a transceiver, an input / output interface, or a circuit, etc.

[0099] In one possible design, the serial number indicating device includes: at least one processor and a communication interface for executing the methods described in the seventh aspect or any possible implementation thereof, specifically including: the at least one processor communicating with an external source using the communication interface; the at least one processor running a computer program that causes the serial number indicating device to execute the methods described in the seventh aspect or any possible implementation thereof. It is understood that the external source may be an object other than the processor, or an object other than the serial number indicating device.

[0100] In another possible design, the serial number indicator is a chip or chip system. The communication interface can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip or chip system. The processor can also be represented as a processing circuit or logic circuit.

[0101] The technical effects of any design method in aspect seventeen can be found in the technical effects of different design methods in aspect seven above, and will not be repeated here.

[0102] In an eighteenth aspect, a serial number indicating device is provided for performing the methods of the eighth aspect or any possible implementation thereof. The serial number indicating device may be a first network device in the eighth aspect or any possible implementation thereof, or a module applied in the first network device, such as a chip or chip system. The serial number indicating device includes modules, units, or means that implement the methods described above, which may be implemented in hardware, software, or by hardware executing corresponding software implementations. The hardware or software includes at least one module or unit corresponding to the functions described above.

[0103] In conjunction with the eighteenth aspect above, in one possible implementation, the serial number indication device includes: a sending unit; wherein the sending unit is configured to send third indication information to the first terminal device, the second indication information being used to indicate RLC entity reconstruction or RLC entity reset.

[0104] Optionally, the device further includes: a processing unit; the processing unit is configured to detect a failure in the second network device, the second network device being the network device that communicated with the first terminal device before the failure occurred.

[0105] In conjunction with the eighteenth aspect above, in another possible implementation, the serial number indication device includes: an input interface, an output interface, and a processing circuit; wherein the output interface is used to send third indication information to the first terminal device, and the second indication information is used to indicate RLC entity reconstruction or RLC entity reset.

[0106] Optionally, the processing circuit is configured to detect a fault in the second network device, which was communicating with the first terminal device before the fault occurred.

[0107] For example, the serial number indicating device further includes a memory coupled to the at least one processor for executing program instructions stored in the memory to cause the serial number indicating device to perform the methods in the eighth aspect or any possible implementation of the eighth aspect.

[0108] In one possible implementation, the memory is used to store program instructions and data. The memory is coupled to the at least one processor, which can invoke and execute the program instructions stored in the memory to cause the indication device of the serial number to perform the methods in the eighth aspect or any possible implementation of the eighth aspect.

[0109] For example, the serial number indicating device further includes a communication interface for communicating with other devices. When the serial number indicating device is an access network device, the communication interface is a transceiver, an input / output interface, or a circuit, etc.

[0110] In one possible design, the serial number indicating device includes: at least one processor and a communication interface for executing the methods described in the eighth aspect or any possible implementation thereof, specifically including: the at least one processor communicating with an external source using the communication interface; the at least one processor running a computer program that causes the serial number indicating device to execute the methods described in the eighth aspect or any possible implementation thereof. It is understood that the external source may be an object other than the processor, or an object other than the serial number indicating device.

[0111] In another possible design, the serial number indicator is a chip or chip system. The communication interface can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip or chip system. The processor can also be represented as a processing circuit or logic circuit.

[0112] The technical effects of any design method in aspect eighteen can be found in the technical effects of different design methods in aspect eight above, and will not be repeated here.

[0113] In a nineteenth aspect, a serial number determining apparatus is provided for performing the method of the ninth aspect or any possible implementation thereof. The serial number determining apparatus may be a terminal device in the ninth aspect or any possible implementation thereof, or a module applied in a terminal device, such as a chip or chip system. The serial number determining apparatus includes modules, units, or means corresponding to the above-described method, which may be implemented in hardware, software, or by hardware executing corresponding software implementations. The hardware or software includes at least one module or unit corresponding to the above-described function.

[0114] In conjunction with the nineteenth aspect above, in one possible implementation, the sequence number determination device includes: a processing unit and a sending unit; wherein, the processing unit is configured to determine a first data packet; the processing unit is further configured to determine a Radio Link Control (RLC) sequence number corresponding to the first data packet based on the Packet Data Convergence Protocol (PDCP) sequence number corresponding to the first data packet; the processing unit is further configured to add the RLC sequence number to the RLC header corresponding to the first data packet; and the sending unit is configured to send the first data packet.

[0115] Optionally, the sending unit is further configured to send a second indication information to the terminal device, the second indication information being used to indicate that a data packet corresponding to at least one RLC sequence number cannot be sent or to indicate that the terminal device ignores the reception of the data packet corresponding to the at least one RLC sequence number.

[0116] In conjunction with the nineteenth aspect above, in another possible implementation, the sequence number determination device includes: an input interface, an output interface, and a processing circuit; wherein the processing circuit is configured to determine a first data packet; the processing circuit is further configured to determine a Radio Link Control (RLC) sequence number corresponding to the first data packet based on the Packet Data Convergence Protocol (PDCP) sequence number corresponding to the first data packet; the processing circuit is further configured to add the RLC sequence number to the RLC header corresponding to the first data packet; and the output interface is configured to transmit the first data packet.

[0117] Optionally, the output interface is further configured to send a second indication information to the terminal device, the second indication information being used to indicate that a data packet corresponding to at least one RLC sequence number cannot be sent or to indicate that the terminal device ignores the reception of the data packet corresponding to the at least one RLC sequence number.

[0118] For example, the serial number determining means further includes a memory coupled to the at least one processor for executing program instructions stored in the memory to cause the serial number determining means to perform the methods in the ninth aspect or any possible implementation thereof.

[0119] In one possible implementation, the memory is used to store program instructions and data. The memory is coupled to the at least one processor, which can invoke and execute the program instructions stored in the memory to cause the sequence number determining device to perform the method in the ninth aspect or any possible implementation thereof.

[0120] For example, the serial number determining device further includes a communication interface for communicating with other devices. When the serial number determining device is a terminal, the communication interface is a transceiver, an input / output interface, or a circuit, etc.

[0121] In one possible design, the serial number determining device includes: at least one processor and a communication interface for executing the methods described in the ninth aspect or any possible implementation thereof, specifically including: the at least one processor communicating with an external source using the communication interface; the at least one processor running a computer program that causes the serial number determining device to execute the methods described in the ninth aspect or any possible implementation thereof. It is understood that the external source may be an object other than the processor, or an object other than the serial number determining device.

[0122] In another possible design, the serial number is determined by a chip or chip system. The communication interface can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuitry on the chip or chip system. The processor can also be represented as a processing circuit or logic circuit.

[0123] The technical effects of any design method in aspect nineteen can be found in the technical effects of different design methods in aspect nine above, and will not be repeated here.

[0124] In a twentieth aspect, a serial number determining apparatus is provided for performing the method in the tenth aspect or any possible implementation thereof. The serial number determining apparatus may be a first network device in the tenth aspect or any possible implementation thereof, or a module applied in the first network device, such as a chip or chip system. The serial number determining apparatus includes modules, units, or means that implement the method described above. These modules, units, or means may be implemented in hardware, software, or by hardware executing corresponding software implementations. The hardware or software includes at least one module or unit corresponding to the functions described above.

[0125] In conjunction with the twentieth aspect above, in one possible implementation, the sequence number determination device includes: a receiving unit; wherein the receiving unit is configured to receive a first data packet from a network device, the first data packet having an RLC header including an RLC sequence number, and the RLC sequence number corresponding to the first data packet being determined based on the Packet Data Convergence Protocol (PDCP) sequence number corresponding to the first data packet.

[0126] Optionally, the device further includes a processing unit; wherein the receiving unit is further configured to receive second indication information from the network device, the second indication information being used to indicate that a data packet corresponding to at least one RLC sequence number cannot be sent or to indicate that the reception of the data packet corresponding to the at least one RLC sequence number should be ignored; and the processing unit is configured to determine, based on the second indication information, to ignore the data packet corresponding to the at least one RLC sequence number that cannot be sent and to continue sliding the receiving window backward.

[0127] In conjunction with the twentieth aspect above, in another possible implementation, the sequence number determination device includes: an input interface, an output interface, and a processing circuit; wherein, the input interface is used to receive a first data packet from a network device, the RLC header of the first data packet including an RLC sequence number, and the RLC sequence number corresponding to the first data packet is determined according to the Packet Data Convergence Protocol (PDCP) sequence number corresponding to the first data packet.

[0128] Optionally, the input interface is further configured to receive second indication information from the network device, the second indication information being used to indicate that a data packet corresponding to at least one RLC sequence number cannot be sent or to indicate that the reception of the data packet corresponding to the at least one RLC sequence number should be ignored; and the processing circuit is configured to determine, based on the second indication information, to ignore the data packet corresponding to the at least one RLC sequence number that cannot be sent and to continue sliding the receiving window backward.

[0129] For example, the serial number determining means further includes a memory coupled to the at least one processor for executing program instructions stored in the memory to cause the serial number determining means to perform the method in the tenth aspect or any possible implementation of the tenth aspect.

[0130] In one possible implementation, the memory is used to store program instructions and data. The memory is coupled to the at least one processor, which can invoke and execute the program instructions stored in the memory to cause the sequence number determining device to perform the method in the tenth aspect or any possible implementation thereof.

[0131] For example, the serial number determining device further includes a communication interface for communicating with other devices. When the serial number determining device is an access network device, the communication interface is a transceiver, an input / output interface, or a circuit, etc.

[0132] In one possible design, the serial number determining device includes: at least one processor and a communication interface for executing the methods described in the tenth aspect or any possible implementation thereof, specifically including: the at least one processor communicating with an external source using the communication interface; the at least one processor running a computer program that causes the serial number determining device to execute the methods described in the tenth aspect or any possible implementation thereof. It is understood that the external source may be an object other than the processor, or an object other than the serial number determining device.

[0133] In another possible design, the serial number is determined by a chip or chip system. The communication interface can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuitry on the chip or chip system. The processor can also be represented as a processing circuit or logic circuit.

[0134] The technical effects of any design method in aspect 20 can be found in the technical effects of different design methods in aspect 10 above, and will not be repeated here.

[0135] In a twentieth aspect, a communication system is provided, including a serial number indicating device in either the eleventh aspect or any implementation thereof, and a serial number indicating device in either the twelfth aspect or any implementation thereof.

[0136] In a twenty-second aspect, a communication system is provided, including a serial number indicating device in either the thirteenth aspect or any implementation thereof, and a serial number indicating device in either the fourteenth aspect or any implementation thereof.

[0137] In a twentieth aspect, a communication system is provided, including a serial number indicating device in either or any implementation of the fifteenth aspect, and a serial number indicating device in either or any implementation of the sixteenth aspect.

[0138] In a twentieth aspect, a communication system is provided, including a serial number indicating device in either the seventeenth aspect or any implementation thereof, and a serial number indicating device in either the eighteenth aspect or any implementation thereof.

[0139] In a twenty-fifth aspect, a communication system is provided, including a serial number determination device in the nineteenth aspect or any implementation thereof, and a serial number determination device in the twentieth aspect or any implementation thereof.

[0140] In a twenty-sixth aspect, a computer-readable storage medium is provided storing a computer program that, when run on a computer, executes the method described in any of the above aspects or implementations thereof.

[0141] In a twenty-seventh aspect, a computer program product is provided that, when run on a computer, causes the method described in any of the above aspects or implementations to be executed.

[0142] In a twenty-eighth aspect, a computer program is provided that, when run on a computer, causes the method described in any of the above aspects or implementations to be executed. Attached Figure Description

[0143] Figure 1 This is a schematic diagram of the protocol stack structure in an uplink transmission scenario;

[0144] Figure 2 This is a schematic diagram of an A / B network structure;

[0145] Figure 3 This application provides a schematic diagram of the architecture of a communication system.

[0146] Figure 4 This is a schematic diagram of the structure of a communication device 300 provided in an embodiment of this application;

[0147] Figure 5 Schematic diagram of a fast switching structure between primary and backup stations;

[0148] Figure 6 This is a schematic diagram illustrating a scenario where the terminal device receives data incorrectly because the starting sequence number in the standby RLC entity cannot be accurately determined after the standby station takes over in RLC non-response mode.

[0149] Figure 7A flowchart illustrating a serial number indication method provided in an embodiment of this application;

[0150] Figure 8 A flowchart illustrating another serial number indication method provided in this application embodiment;

[0151] Figure 9 A flowchart illustrating yet another serial number indication method provided in this application embodiment;

[0152] Figure 10 A flowchart illustrating yet another serial number indication method provided in this application embodiment;

[0153] Figure 11 This is a schematic diagram illustrating a scenario where a terminal device receives data incorrectly due to the serial number in the RLC entity and the serial number in the PDCP entity being set separately after the backup station takes over in RLC response mode.

[0154] Figure 12 A flowchart illustrating a method for determining a serial number provided in an embodiment of this application;

[0155] Figure 13 A schematic diagram of the structure of a serial number indicating device provided in an embodiment of this application;

[0156] Figure 14 A schematic diagram of another serial number indicating device provided in an embodiment of this application;

[0157] Figure 15 A schematic diagram of the structure of another serial number indicating device provided in an embodiment of this application;

[0158] Figure 16 A schematic diagram of the structure of another serial number indicating device provided in an embodiment of this application;

[0159] Figure 17 A schematic diagram of the structure of another serial number indicating device provided in an embodiment of this application;

[0160] Figure 18 A schematic diagram of the structure of a serial number indicating device provided in an embodiment of this application;

[0161] Figure 19 A schematic diagram of another serial number indicating device provided in an embodiment of this application;

[0162] Figure 20 A schematic diagram of the structure of another serial number indicating device provided in an embodiment of this application;

[0163] Figure 21 A schematic diagram of a serial number determination device provided in an embodiment of this application;

[0164] Figure 22 A schematic diagram of another serial number determination device provided in an embodiment of this application. Detailed Implementation

[0165] The embodiments of this application are described below with reference to the accompanying drawings.

[0166] The technical solutions of this application can be applied to various communication systems, such as Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD) systems, 5th Generation (5G) systems, or New Radio (NR). The 5G mobile communication systems involved in this application include non-standalone (NSA) 5G mobile communication systems or standalone (SA) 5G mobile communication systems. The technical solutions provided in this application can also be applied to future communication systems, such as 6th Generation (6G) mobile communication systems. The communication systems involved in this application can also be public land mobile networks (PLMNs), device-to-device (D2D) communication systems, machine-to-machine (M2M) communication systems, Internet of Things (IoT) systems, vehicle-to-everything (V2X) communication systems, or other communication systems.

[0167] Figure 3 This is a schematic diagram of the architecture of a communication system provided in an embodiment of this application. The communication system 1000 includes: a first network device 101, a second network device 102, and a terminal device 103. The first network device 101, the second network device 102, and the terminal device 103 can communicate with each other, for example, through a wireless network. When the second network device 102 is working normally, the first network device 101 does not transmit data to the terminal device. When the first network device 101 detects a fault in the second network device 102, it immediately takes over the second network device 102 and transmits data to the terminal device.

[0168] The terminal device 103 in this application embodiment may refer to an access terminal, user unit, user station, mobile station, mobile station, relay station, remote station, remote terminal, mobile device, user terminal, user equipment (UE), terminal, wireless communication device, user agent, user equipment, cellular phone, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, personal digital assistant (PDA), handheld device with wireless communication function, computing device or other processing device connected to a wireless modem, vehicle device, wearable device, terminal in future 5G network, terminal in future evolved PLMN, or terminal in future vehicle network, etc., but this application embodiment does not limit it to this.

[0169] By way of example and not limitation, in the embodiments of this application, the terminal device 103 may be a mobile phone, a tablet computer, a computer with wireless transceiver function, a virtual reality terminal, an augmented reality terminal, a wireless terminal in industrial control, a wireless terminal in autonomous driving, a wireless terminal in remote surgery, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc.

[0170] By way of example and not limitation, in this application embodiment, wearable devices can also be called wearable smart devices. This is a general term for devices that utilize wearable technology to intelligently design and develop everyday wearables, such as glasses, gloves, watches, clothing, and shoes. Wearable devices are portable devices that are worn directly on the body or integrated into the user's clothing or accessories. Wearable devices are not merely hardware devices; they achieve powerful functions through software support, data interaction, and cloud interaction. Broadly defined, wearable smart devices include those that are feature-rich, large in size, and can achieve complete or partial functionality without relying on a smartphone, such as smartwatches or smart glasses, as well as those that focus on a specific application function and require use with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0171] Furthermore, in this embodiment, the terminal device 103 can also be a terminal in an Internet of Things (IoT) system. IoT is an important component of future information technology development, and its main technical feature is connecting objects to networks through communication technologies, thereby realizing an intelligent network of human-machine interconnection and object-to-object interconnection. In this embodiment, IoT technology can achieve massive connectivity, deep coverage, and terminal power saving through technologies such as narrowband (NB).

[0172] In addition, in this embodiment, the terminal device 103 may also include sensors such as smart printers, train detectors, and gas stations. Its main functions include collecting data (for some terminals), receiving control information and downlink data from access network devices, and sending electromagnetic waves to transmit uplink data to access network devices.

[0173] Optionally, the first network device 101 / second network device 102 in this embodiment can be any communication device with wireless transceiver function for communicating with the terminal device 103. The first network device 101 / second network device 102 includes, but is not limited to: evolved node B (eNB), baseband unit (BBU), access point (AP), wireless relay node, wireless backhaul node, transmission point (TP), or transmission reception point (TRP) in a wireless fidelity (WIFI) system. The first network device 101 / second network device 102 can also be a gNB, TRP, or TP in a 5G system, or one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system. Furthermore, the first network device 101 / second network device 102 can also be a network node constituting a gNB or TP, such as a BBU, or a distributed unit (DU). The first network device 101 / second network device 102 can also be a network device in a 5.5G or 6G system.

[0174] In some deployments, a gNB may include a centralized unit (CU) and a dedicated unit (DU). Additionally, a gNB may include an active antenna unit (AAU). The CU implements some of the gNB's functions, and the DU implements others. For example, the CU handles non-real-time protocols and services, implementing radio resource control (RRC) and packet data convergence protocol (PDCP) layer functions. The DU handles physical layer protocols and real-time services, implementing radio link control (RLC), media access control (MAC), and physical layer (PHY) layer functions. The AAU implements some physical layer processing functions, radio frequency processing, and active antenna-related functions. Since RRC layer information ultimately becomes PHY layer information, or is derived from PHY layer information, in this architecture, higher-layer signaling, such as RRC layer signaling, can also be considered as being sent by the DU, or by both the DU and AAU. It is understandable that access network equipment can be one or more of the following: CU node, DU node, and AAU node.

[0175] Optionally, in this embodiment of the application, the first network device 101 / second network device 102 and the terminal device 103 can communicate via licensed spectrum, unlicensed spectrum, or both. The first network device 101 and the terminal device 103 can communicate via a higher spectrum (e.g., 4.9 GHz), while the second network device 102 and the terminal device 103 can communicate via a lower spectrum (e.g., 2.5 GHz).

[0176] Optionally, the first network device 101, the second network device 102, and the terminal device 103 in this application embodiment can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can also be deployed in the air on airplanes, balloons, and artificial satellites. The embodiments of this application embodiment do not limit the application scenarios of the first network device 101, the second network device 102, and the terminal device 103.

[0177] Optionally, in this embodiment, the first network device 101, the second network device 102, and the terminal device 103 include a hardware layer, an operating system layer running on top of the hardware layer, and an application layer running on top of the operating system layer. The hardware layer includes hardware such as a central processing unit (CPU), a memory management unit (MMU), and memory (also called main memory). The operating system can be any one or more computer operating systems that implement business processing through processes, such as Linux, Unix, Android, iOS, or Windows. The application layer includes applications such as browsers, address books, word processing software, and instant messaging software. Furthermore, the embodiments of this application do not particularly limit the specific structure of the execution subject of the method provided in the embodiments of this application. As long as it is possible to communicate according to the method provided in the embodiments of this application by running a program that records the code of the method provided in the embodiments of this application, for example, the execution subject of the method provided in the embodiments of this application may be the first network device 101, the second network device 102 and the terminal device 103, or it may be a functional module in the first network device 101, the second network device 102 and the terminal device 103 that can call and execute the program.

[0178] In other words, the related functions of the first network device 101, the second network device 102, and the terminal device 103 in the embodiments of this application can be implemented by one device, or by multiple devices, or by at least one functional module within a single device. This application does not impose specific limitations on these functions. It is understood that the aforementioned functions can be network elements in hardware devices, software functions running on dedicated hardware, a combination of hardware and software, or virtualization functions instantiated on a platform (e.g., a cloud platform).

[0179] For example, the related functions of the first network device 101, the second network device 102, and the terminal device 103 in the embodiments of this application can be achieved through... Figure 4 This is achieved through the communication device 300. Figure 4 The diagram shown is a structural schematic of a communication device 300 provided in an embodiment of this application. The communication device 300 includes at least one processor 301, a communication line 302, and at least one communication interface. Figure 4 (This is merely an example illustration, using a communication interface 304 and a processor 301 as examples. Optionally, a memory 303 may also be included.)

[0180] The processor 301 may be a central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or at least one integrated circuit for controlling the execution of the program of the embodiment of this application.

[0181] Communication line 302 may include a path for connecting different components.

[0182] The communication interface 304 can be a transceiver module used to communicate with other devices or communication networks, such as Ethernet, RAN, wireless local area networks (WLAN), etc. For example, the transceiver module can be a transceiver or a similar device. Optionally, the communication interface 304 can also be a transceiver circuit located within the processor 301, used to implement the processor's signal input and signal output.

[0183] Memory 303 can be a device with storage function. For example, it can be read-only memory (ROM) or other types of static storage devices capable of storing static information and instructions; random access memory (RAM) or other types of dynamic storage devices capable of storing information and instructions; electrically erasable programmable read-only memory (EEPROM); compact disc read-only memory (CD-ROM) or other optical disc storage; optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.); magnetic disk storage media or other magnetic storage devices; or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited to these. Memory can exist independently and be connected to the processor via communication line 302. Memory can also be integrated with the processor.

[0184] The memory 303 stores computer execution instructions for implementing the schemes of the embodiments of this application, and the processor 301 controls the execution. The processor 301 executes the computer execution instructions stored in the memory 303, thereby implementing the communication method provided in the embodiments of this application.

[0185] Alternatively, the processor 301 may execute the processing-related functions in the communication method provided in the embodiments of this application, and the communication interface 304 may be responsible for communicating with other devices or communication networks. The embodiments of this application do not specifically limit this.

[0186] The computer execution instructions in the embodiments of this application may also be referred to as application code, and the embodiments of this application do not specifically limit this.

[0187] In a specific implementation, as one example, the processor 301 may include at least one CPU, for example... Figure 4 CPU0 and CPU1 in the CPU.

[0188] In a specific implementation, as one example, the communication device 300 may include multiple processors, such as... Figure 4 Processors 301 and 305 are described herein. Each of these processors may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. A processor may refer to at least one device, circuit, and / or a processing core used for processing data (e.g., computer program instructions).

[0189] In a specific implementation, as one embodiment, the communication device 300 may further include an output device 306 and an input device 307. The output device 306 communicates with the processor 301 and can display information in various ways.

[0190] The aforementioned communication device 300 can be a general-purpose device or a special-purpose device. For example, the communication device 300 can be a desktop computer, a portable computer, a network server, a handheld digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal, an embedded device, or something else with... Figure 4 Devices with similar structures. This application does not limit the type of communication device 300 to any particular embodiment.

[0191] The following will combine Figures 1 to 12 The method for indicating and determining the serial number provided in the embodiments of this application will be described in detail.

[0192] It should be noted that the message names between various network elements or the names of the parameters in the messages in this embodiment are just examples. Other names may be used in the actual implementation. This embodiment does not impose any specific limitations on this.

[0193] The embodiments of this application can be used alone or in combination.

[0194] First, the terms that may be involved in the embodiments of this application will be explained:

[0195] In wireless communication, when a service needs to be transmitted, the network device will configure a radio bearer for the terminal device for service transmission. The configuration of the radio bearer includes PDCP configuration information. In addition, the configuration information of the radio bearer will be associated with the RLC configuration information through the radio bearer identifier, or the configuration information of the radio bearer may contain the RLC configuration information.

[0196] The configuration information of RLC can configure the operation of RLC. Among them, the working mode of RLC can be configured as any one of transparent mode (TM), unacknowledged mode (UM), and acknowledged mode (AM).

[0197] In AM RLC mode, the receiver determines which SDUs (or SDU segments) have been lost based on the SN (Signal Serial Number) in the header of the received RLC data PDU. When the conditions for sending a Status PDU are met, the receiver sends a Status PDU to the sender to inform them which RLC SDUs or segments have been successfully received and which have not. The sender can then retransmit the lost SDUs or SDU segments based on the status report, ensuring reliable data packet transmission. For RLCSDUs, if only a portion of a segment is lost, only the lost segment needs to be retransmitted; the entire SDU does not need to be retransmitted.

[0198] When RLC is configured as UM RLC, if an RLC SDU is not segmented during transmission, there is no need to add the SN number to the header of the RLC PDU composed of complete RLC SDUs. If the SDU is segmented during transmission, the SN number needs to be added to the header of the RLC PDU composed of RLC SDU segments. This is because if the PDU is composed of complete SDUs, the RLC layer at the receiving end can directly deliver it to the upper layer without reading the SN number. However, for PDUs composed of segmented SDUs, the receiving end needs to determine which SDU segments belong to the same complete SDU based on the SN number in the header, and then assemble them together.

[0199] To address equipment reliability issues, another rapid master / slave switchover solution has been proposed, such as... Figure 5The diagram illustrates a rapid failover architecture between the primary and backup stations. When the primary station is functioning normally, the backup station does not transmit data with the terminal device. However, when the backup station detects a failure in the primary station, it immediately initiates data transmission with the terminal device. But when the primary station fails and the backup station takes over communication with the terminal device, the backup station may not be aware of the terminal device's reception of RLC data packets. In other words, the backup station may not know which RLC data packets the terminal device has received from the primary station. Therefore, the sequence numbers of the RLC data packets sent by the backup station and those in the terminal device may not align, potentially leading to reception errors and reduced communication reliability.

[0200] However, despite improved equipment reliability, a significant number of data packets are lost during rapid switching between primary and backup stations due to the inability to determine the sequence number in the backup station.

[0201] like Figure 6 As shown, in UM RLC mode, because the starting sequence number in the standby RLC entity cannot be accurately determined after the standby station takes over, a reception error occurs when the terminal device receives RLC data packets due to the misalignment of the RLC SN numbers between the terminal device and the standby station. In UM mode, the SN number is only included in the packet header when the RLC PDU contains SDU segments; otherwise, it is not included. An example is given below. Figure 6As shown, in the main station, packet 8 is divided into segment A and segment B. The SN number carried in the header of the RLCPDU packet corresponding to both segments is 8. In addition, the PDU packet header also contains indication information indicating which segment it is, "8A" or "8B". Packet 9 is divided into segment A and segment B. The SN number carried in the header of the RLC PDU packet corresponding to both segments is 9. In addition, the PDU packet header also contains indication information indicating which segment it is, "9A" or "9B". Other RLC SDUs are not segmented, so their corresponding RLC PDU packet headers do not contain SN numbers. Assuming that before the primary station failure, the serial numbers (SNs) assigned to RLC segments have been sequentially arranged from the initial value to number 9, and segment B of packet 8 and segment A of packet 9 are lost during transmission, then the RLC buffer window maintained by the UE will store segment A of packet 8 and segment B of packet 9 awaiting reassembly. If the primary station fails at this time, the backup station will begin communicating with the UE. Since the backup station is unaware of the primary station's RLC SN settings, when transmitting SDU segments, it may start setting the SN from the initial value (e.g., SN=0 or SN=1). Suppose that during transmission, segment B of packet 1 and segment A of packet 2 are lost by the primary station. However, because the UE's RLC receive window size is fixed, segment A of packet 1 and segment B of packet 2 may fall outside the window and be discarded by the UE, resulting in packet loss. On the other hand, the UE had already received packet segments 8 and 9 (i.e., 8A and 9B) from the master station. These segments were waiting to be reassembled in the UE's RLC buffer window. If the backup station had reconfigured its SN from the initial stage, when the SN of a segment of an RLC SDU reached segment 8, the UE would have received segment 8 from the backup station and merged it with the segment 8 received from the master station. However, because the backup station had reconfigured its SN, the segment 8 sent by the backup station and the segment 8 sent by the master station were not segments of the same SDU. The UE might have incorrectly merged segments of different SDUs, leading to a transmission error.

[0202] Based on this, such as Figure 7 As shown in the figure, this application provides a method for indicating a serial number, which may include the following steps:

[0203] S101, the first network device sends a first indication message to the first terminal device, the first indication message being used to instruct the first terminal device to report the first sequence number in the RLC entity. Accordingly, the first terminal device receives the first indication message.

[0204] The first network device 101 can be either the aforementioned backup station or the aforementioned master station.

[0205] Before communicating with the first network device, the first terminal device may receive and cache the RLC PDU sent by the second network device. The RLC PDU may contain RLC SDU segments. The header of the RLC PDU corresponding to each RLC SDU segment contains the SN. Therefore, when the first network device establishes communication with the first terminal device (e.g., when the first network device starts sending data packets to the first terminal device), or during communication (e.g., when the first network device sends data packets to the first terminal device), a first indication information can be sent to the first terminal device. This first indication information instructs the first terminal device to report the first sequence number in its RLC entity. This first indication information may be radio resource control (RRC) signaling, media access control-control element (MAC-CE), or downlink control information (DCI), etc.

[0206] For example, when the first network device detects a malfunction in the second network device, the first network device sends the aforementioned first indication information to the first terminal device. Therefore, before step S101, the first network device detects a malfunction in the second network device, which is the network device that communicated with the first terminal device before the malfunction occurred. The first network device could be... Figure 6 The backup station shown, the second network device can be Figure 6 The main station shown.

[0207] S102. The first terminal device sends a first sequence number from the RLC entity to the first network device according to the first instruction information; wherein the first sequence number is used to indicate the starting sequence number in the RLC entity of the first network device. Accordingly, the first network device receives the first sequence number from the RLC entity.

[0208] After receiving the first indication information, the first terminal device sends the first sequence number from its RLC entity to the network device according to the indication information. The RLC entity can be understood as an entity that performs segmentation, header addition, and other processing on the PDUs received from the upper layer (PDCP layer). It is worth noting that the first terminal device may have established multiple RLC entities. In this case, the first terminal device can report the first sequence number from one or more RLC entities, or report the first sequence numbers from all RLC entities, based on the first indication information from the network device; this is not limited here. The specific first sequence numbers of which RLC entities the first terminal device reports can also be indicated by the indication information sent by the network device.

[0209] Optionally, the first sequence number is the sequence number of the RLC entity of the first terminal device. That is, the first sequence number is the sequence number of a segment of one or more RLC SDUs received or cached by the first terminal device. Since the first terminal device receives segments of one or more RLC SDUs from the second network device, the RLC sequence number in the first terminal device is aligned with the RLC sequence number of the second network device. Therefore, the first sequence number can also be the sequence number of the RLC entity of the second network device.

[0210] Furthermore, the first serial number is the maximum value among the serial numbers of the RLC entity of the first terminal device. That is, the first serial number is the maximum value among the serial numbers of segments of one or more RLC SDUs received or cached by the first terminal device. Figure 6 As shown, if the UE buffers segments 8A and 9B sent by the master station, then the maximum value in the sequence number of the UE's RLC entity is 9. Alternatively, the first sequence number could be the SN value corresponding to the upper boundary of the UE's RLC receive window.

[0211] S103. The first network device determines the starting serial number in the RLC entity of the first network device according to the first serial number.

[0212] The first network device receives a first sequence number from the RLC entity sent by the first terminal device, and determines a starting sequence number in the RLC entity of the first network device based on the first sequence number, so that the sequence numbers of the RLC entities in the first network device and the first terminal device are aligned. Specifically, for example, if the first sequence number is the maximum value among the sequence numbers in the RLC entity of the first terminal device, then the starting sequence number in the RLC entity of the first network device can be that maximum value, or it can be the next sequence number after the maximum sequence number, or it can be a sequence number associated with the maximum sequence number. Figure 6 As shown, if the maximum value of the sequence number in the RLC entity obtained by the backup station is 9, then the starting sequence number of the next SDU segment in the backup station's RLC entity can be either 9 or 10. Therefore, after the UE receives segment number 10 from the backup station, it will not incorrectly merge it with segments 8A and 9B previously received from the primary station, improving communication reliability. Furthermore, the UE caches RLC SDUs sequentially according to their sequence numbers, preventing packet loss due to segments received by the backup station being outside the RLC reception window.

[0213] According to an embodiment of this application, a serial number indication method is provided. A first terminal device reports a first serial number in an RLC entity according to an instruction from a first network device. The first network device can determine the starting serial number in its RLC entity based on the first serial number, so that the serial numbers of the RLC entities in the first network device and the first terminal device are aligned. Thus, when the first terminal device receives data packets sent by the first network device, it can accurately merge them based on the aligned serial numbers, thereby improving the reliability of communication.

[0214] like Figure 8 As shown in the embodiment of this application, another method for indicating a serial number is provided, which may include the following steps:

[0215] S201, the second network device sends first information to the first network device, the first information including a second sequence number, the second sequence number being used to indicate the starting sequence number in the RLC entity of the first network device. Accordingly, the first network device receives the first information from the second network device.

[0216] The second network device and the first network device can maintain communication at all times. Before the second network device fails, it can send first information to the first network device, which includes a second sequence number. This first information may be context information of the first terminal device interacting with the second network device and the first network device. The second network device and the first network device can maintain communication using a "heartbeat mechanism," such as periodically exchanging information or periodically sending first information to the first network device, to keep the communication states of the two network devices synchronized. The communication states include at least data transmission state, data reception state, signaling configuration state, UE context, and base station context.

[0217] Before the second network device fails, it segments the RLC SDU to be sent to the first terminal device and assigns a corresponding sequence number to each RLC SDU segment. Therefore, this second sequence number is the sequence number in the RLC entity of the second network device.

[0218] Specifically, the RLC entity of the second network device includes sequence numbers corresponding to one or more RLC SDU segments. The second sequence number can be the maximum value among the sequence numbers of the RLC entity of the second network device. Before the second network device malfunctions, if the transmission process is normal and no data packets are lost, the maximum value among the sequence numbers of the RLC entity of the second network device is the same as the maximum value among the sequence numbers of the RLC entity of the first terminal device. When the RLC layer of the second network device receives a new RLC SDU from the upper layer, if the SDU needs to be segmented, the RLC entity of the second network device needs to continue allocating new sequence numbers for the SDU segments. That is, the maximum sequence number in the RLC entity will be updated. Therefore, as an optional implementation, step S201 can be: when the maximum sequence number in the RLC entity of the second network device is updated, send first information to the first network device. That is, when the maximum sequence number in the RLC entity of the second network device is updated, the second network device is triggered to send first information to the first network device. The second network device sends the latest maximum value among the sequence numbers of the RLC entity to the first network device, so that the first network device can obtain the maximum value among the sequence numbers of the RLC entity in the second network device in a timely manner.

[0219] S202. The first network device determines the starting serial number in the RLC entity of the first network device according to the second serial number.

[0220] Because the first network device promptly obtains the second serial number, when the second network device malfunctions and takes over, it can determine the starting serial number in the RLC entity of the first network device based on the second serial number. As one implementation, after the first network device promptly obtains the maximum value of the serial numbers in the RLC entity of the second network device, it can determine the starting serial number in the RLC entity of the first network device based on the maximum value. This starting serial number can be the next serial number after the maximum value in the RLC entity of the second network device. Figure 6 As shown, if the maximum value of the sequence number in the RLC entity obtained by the backup station is 9, then the starting sequence number of the next SDU segment in the backup station's RLC entity is determined to be 10. Therefore, when the UE receives segment 10 from the backup station, it will not incorrectly merge it with segments 8 and 9 previously received from the primary station, improving communication reliability. Furthermore, the UE caches RLC SDUs sequentially according to their sequence numbers, preventing packet loss due to segments received by the backup station being outside the RLC reception window.

[0221] According to an embodiment of this application, a serial number indication method is provided. When no fault occurs, the second network device sends a second serial number to the first network device. The first network device determines the starting serial number in the RLC entity of the first network device based on the second serial number. Thus, when the second network device fails and the first network device takes over the second network device, the serial numbers of the RLC entities in the first network device and the first terminal device can be aligned. When the first terminal device receives data packets sent by the first network device, it can accurately merge them according to the aligned serial numbers, thereby improving the reliability of communication.

[0222] like Figure 9 As shown in the embodiment of this application, another method for indicating a serial number is provided, which may include the following steps:

[0223] S301. The first terminal device periodically sends second information to the first network device or the second network device. The second information includes a first sequence number in the RLC entity, which indicates the starting sequence number in the RLC entity of the first network device or the second network device. Correspondingly, the first network device or the second network device receives the second information periodically sent by the first terminal device. Specifically, before the second network fails, both the first and second network devices may receive the second information sent by the first terminal device; after the second network fails, only the first network device can receive the second information sent by the first terminal device.

[0224] Before communicating with the first network device, the first terminal device may receive and cache an RLC PDU sent by the second network device. The RLC PDU may contain RLC SDU segments. The header of the RLC PDU containing the RLC SDU segments includes a serial number (SN). The first terminal device may periodically send second information to the first network device, the second information including the first sequence number in the RLC entity. Specifically, the first terminal device may periodically send the second information to the first network device before or after the first network device takes over the second network device, thereby enabling the first network device to obtain the first sequence number in the RLC entity in a timely manner.

[0225] Specifically, in one implementation, the first terminal device starts a timer; when the timer expires, the first terminal device sends a second message to the first network device and restarts the timer. By setting a timer to periodically send the second message to the first network device according to the timeout duration, the first network device can obtain the first sequence number in the RLC entity in a timely manner. In one approach, the timeout duration can be set based on experimental or empirical values; in another implementation, the timer can be configured by the network device for the terminal device.

[0226] Optionally, the first sequence number is the sequence number of the RLC entity of the first terminal device. That is, the first sequence number is the sequence number of one or more RLC SDU segments received or cached by the first terminal device. Since the first terminal device receives segments of one or more RLC SDUs from the second network device, the first sequence number can also be the sequence number of the RLC entity of the second network device.

[0227] Furthermore, the first serial number can be the maximum value among the serial numbers of the RLC entities of the first terminal device. That is, the first serial number is the maximum value among the serial numbers of segments of one or more RLC SDUs received or cached by the first terminal device. The first serial number can contain multiple serial numbers from different RLC entities. Figure 6 As shown, the UE buffers segments 8A and 9B sent by the master station, so the maximum value in the sequence number of the UE's RLC entity is 9. That is, the first sequence number can be the SN value corresponding to the upper boundary of the UE's RLC receive window.

[0228] S302. The first network device determines the starting serial number in the RLC entity of the first network device according to the first serial number.

[0229] A first network device receives a first sequence number from at least one RLC entity sent by a first terminal device. Based on this first sequence number, it determines a starting sequence number in the corresponding RLC entity of the first network device, aligning the sequence numbers of the RLC entities in the first network device with those in the first terminal device. Specifically, for example, if the first sequence number is the maximum value among the sequence numbers in the RLC entities of the first terminal device, then the starting sequence number in the RLC entity of the first network device can be either this maximum value or the next sequence number after the maximum sequence number. Figure 6 As shown, if the maximum value of the sequence number in the RLC entity obtained by the backup station is 9, then the starting sequence number of the next SDU segment in the backup station's RLC entity is determined to be 10. Therefore, after the UE receives the 10A segment sent by the backup station, it will not incorrectly merge it with the 8A and 9B segments previously received from the primary station, improving communication reliability. Furthermore, the UE caches RLC SDUs sequentially according to their sequence numbers, preventing packet loss due to segments received by the backup station being outside the RLC reception window.

[0230] According to an embodiment of this application, a sequence number indication method is provided in which a first terminal device periodically sends a first sequence number in an RLC entity to a first network device. The first network device can determine the starting sequence number in its RLC entity based on the first sequence number, so that the sequence numbers of the RLC entities in the first network device and the first terminal device are aligned. This allows the first terminal device to avoid incorrectly merging segments of different RLCSDUs when receiving data packets sent by the first network device, thereby improving the reliability of communication.

[0231] like Figure 10 As shown in the embodiment of this application, another method for indicating a serial number is provided, which may include the following steps:

[0232] S401, the first network device sends third instruction information to the first terminal device, the third instruction information being used to instruct the RLC entity to rebuild or reset. Correspondingly, the first terminal device receives the third instruction information from the first network device.

[0233] The first network device detects a failure in the second network device, which was communicating with the first terminal device before the failure. Before communicating with the first network device, the first terminal device may have received and buffered RLC PDUs sent by the second network device. These RLC PDUs may contain RLC SDU segments. The header of the RLC PDU corresponding to each RLC SDU segment contains a serial number (SN). The first network device does not know the sequence number in the first terminal device's RLC entity, and therefore does not know from which starting sequence number to set the sequence number of the SDU segments to be transmitted in the RLC entity. In this case, the first network device can send a third indication message to the first terminal device. This third indication message instructs the first terminal device to rebuild or reset the RLC entity. Instructing the first terminal device to rebuild or reset the RLC entity means instructing it to perform at least one of the following actions on the RLC entity: initialize variables in the RLC entity, initialize timers in the RLC entity, clear the buffer of the RLC entity, or discard received data packets.

[0234] The third indication information can be any of the following: RRC signaling, PDCP control PDU, RLC control PDU, MAC CE, or downlink control information (DCI). A PDCP control PDU indicates that the PDCP PDU is used to transmit control information. An RLC control PDU indicates that the RLC PDU is used to transmit control information.

[0235] S402. The first terminal device performs at least one of the following operations according to the third instruction information: RLC variable initialization, RLC timer initialization, RLC entity buffer clearing, or packet dropping.

[0236] Upon receiving the third instruction, the first terminal device performs at least one of the following operations: RLC variable initialization, RLC entity buffer clearing, RLC timer initialization, or packet dropping. RLC variables include SN number, transmit window parameters, receive window parameters, etc. RLC variable initialization restores the aforementioned RLC variables to their initial state in the RRC configuration or sets them to zero. RLC timer initialization resets the timer, starting from 0 or from a pre-set initial state. In this way, the sequence numbers of the RLC entities in both the first terminal device and the first network device start from their initial values, and the previously cached SDU segments are cleared, thus preventing erroneous merging.

[0237] According to an embodiment of this application, a serial number indication method is provided in which a first terminal device performs RLC variable initialization, RLC timer initialization, RLC entity buffer clearing, or data packet discarding based on the indication information of a first network device, so that the serial numbers of the first terminal device and the RLC entities in the first network device are aligned. Thus, when the first terminal device receives data packets sent by the first network device, it can accurately merge them according to the aligned serial numbers, thereby improving the reliability of communication.

[0238] Each protocol layer (such as PDCP layer, RLC layer, etc.) adds a serial number (SN) to the header of its corresponding data packet so that the receiving end can process the data packet based on the SN in the header. Currently, the SNs of different protocol layers are set independently and are not related to each other. This can lead to packet loss problems in the UE's RLC layer due to inconsistent interpretation of data packets after the primary station fails and the backup station takes over. For example... Figure 11The diagram illustrates a scenario where a terminal device receives data incorrectly due to the sequence number in the RLC entity being set differently from the sequence number in the PDCP entity after the backup station takes over under AM RLC. It is assumed that before the master station fails, it has already sent all data packets with PDCP SNs 1-4, and the corresponding RLC SNs are also 1-4. Since both the PDCP and RLC layers are numbered starting from 1, a data packet with PDCP SN 1, after being processed by the RLC layer, will also have an RLC SN of 1. If the master station fails after sending packet number 4, the backup station will take over the work. The dummy device station starts sending data packets with PDCP SN 3, and its corresponding RLC SN is also 3. If the data packet with PDCP SN 4 is lost (for example, the core network device loses the data packet with PDCP SN 4 when transmitting it to the backup station), the backup station will send a data packet with PDCP SN 5 after sending the data packet with PDCP SN 3. Since the RLC layer is independent of the PDCP number, the RLC will set the RLC SN of the data packet with PDCP SN 5 to 4. At this time, because the RLC layer on the UE side has already received a data packet with RLC SN 4 sent by the primary station, it will consider the data packet with RLC SN 4 received from the backup station to be a duplicate data packet and discard it. However, the data packet with RLC SN 4 received from the backup station is actually a different data packet from the data packet with RLC SN 4 received from the primary station and should not be discarded.

[0239] Based on this, such as Figure 12 As shown in the embodiment of this application, a method for determining a serial number is provided, which may include the following steps:

[0240] S501, The network device determines the first data packet.

[0241] The network device can be as follows: Figure 11 The backup station is shown. The network device determines a first data packet, which can be any data packet to be sent to the terminal device. Specifically, the first data packet is an SDU segment of a PDCP PDU or an SDU segment of an RLC PDU.

[0242] S502. The network device determines the RLC sequence number corresponding to the first data packet based on the PDCP sequence number corresponding to the first data packet.

[0243] Both the PDCP layer and the RLC layer need to add a serial number (SN) to the header corresponding to the first data packet (i.e., the segment). The PDCP PDU is transmitted to the RLC layer. In this embodiment, the network device can determine the RLC sequence number corresponding to the first data packet based on the PDCP sequence number corresponding to the first data packet.

[0244] Specifically, in one implementation, the RLC sequence number can be equal to the PDCP sequence number. That is, assuming the PDCP layer sets the sequence number of the first data packet to X, the RLC layer will also set the sequence number of the first data packet to sequence number X.

[0245] In another implementation, the RLC sequence number can also be offset from the PDCP sequence number by a value of N, where N is a positive or negative integer. That is, the RLC sequence number can be larger or smaller than the PDCP sequence number. Specifically, assuming the PDCP layer marks the first data packet as sequence number X, the RLC layer will mark it as sequence number X+N. N can take values ​​of 0, 1, 2, etc. This offset N can be specified by the protocol or configured on the network side.

[0246] S503. The network device adds the RLC sequence number to the RLC header corresponding to the first data packet.

[0247] The network device adds the sequence number of each RLC SDU to the header of the corresponding RLC PDU, so that after receiving the RLC PDU, the terminal device can perform reassembly, retransmission, and other processing based on the sequence numbers of each RLC SDU.

[0248] S504. The network device sends a first data packet. Correspondingly, the terminal device receives the first data packet from the network device.

[0249] When a network device sends a first data packet, the actual processing involves passing the packet from the network device's RLC layer to its MAC layer, then from the MAC layer to its physical layer. After processing by the physical layer, the packet is sent to the terminal device over the air interface. Upon receiving the packet, the terminal device passes it to its physical layer, which then passes it to its MAC layer, which in turn passes it to its RLC layer.

[0250] After receiving the first data packet, the terminal device, due to the upper-layer guarantee that for the same first data packet, the PDCP SN is the same when the primary station and the backup station transmit data packets to the UE, can further guarantee that the RLC SN is also the same when the primary station and the backup station transmit the same first data packet. Thus, when the backup station's PDCP layer loses a data packet, the RLC will skip that SN when setting it. That is, if the data packet with PDCP SN 4 is lost, the backup station will send the data packet with PDCP SN 3 and then send the data packet with PDCP SN 5. For the data packet with PDCP SN 5, the RLC will also set its RLC SN to 5. Therefore, after receiving the first data packet, the UE will not mistakenly discard it as a duplicate data packet, but will instead hand it over to the PDCP layer for processing.

[0251] Furthermore, the method may also include (shown as dashed lines in the figure):

[0252] S505, the network device sends a second indication message to the terminal device, the second indication message being used to indicate that data packets corresponding to at least one RLC sequence number cannot be sent or to instruct the terminal device to ignore the reception of these data packets. Accordingly, the terminal device receives the second indication message from the network device.

[0253] When a packet is lost at the upper layer of the RLC layer, the network device's RLC layer will skip one sequence number when setting the sequence number of the RLC entity. Therefore, in AM RLC mode, the terminal device will also detect the loss of a data packet corresponding to a sequence number. At this point, the terminal device will send a feedback message to the network device requesting retransmission. Furthermore, if the lost data packet is not received, the terminal device cannot continue receiving data packets. The network device, knowing that the data packet corresponding to that sequence number has been lost and could not be successfully transmitted, sends a second indication message to the terminal device, indicating that at least one data packet corresponding to an RLC sequence number could not be transmitted. "Could not be transmitted" means that the network device cannot send these data packets to the terminal device, and the terminal device will not receive them. Therefore, even if the terminal device detects that at least one data packet corresponding to an RLC sequence number has not been successfully received, it does not need to continue waiting for these data packets but continues to receive other data packets.

[0254] The second indication information is contained in the RLC control PDU; or the second indication information is contained in the RLC data PDU. The RLC control PDU carries the first indication information, which indicates the function of the PDU. Furthermore, the RLC control PDU may also carry at least one RLC sequence number. Additionally, the RLC data PDU may not contain a payload or an RLC SDU (payload), but only a header.

[0255] S506, the first terminal device determines, based on the second instruction information, to ignore the data packet corresponding to at least one RLC sequence number that cannot be sent and continues to slide the receiving window backward (to continue receiving other data packets).

[0256] The terminal device ignores the reception gaps caused by the loss of data packets corresponding to at least one RLC sequence number based on the second indication information, thereby moving the reception window forward to continue receiving subsequent data packets and improving communication efficiency. Specifically, after receiving the second indication information, the terminal device updates the RX_next parameter to the next incompletely received RLC SDU. Here, the RX_next parameter refers to the SN number following the SN number corresponding to the last RLCSDU among multiple RLC SDUs received consecutively in the correct order, or it can be the lower boundary of the reception window.

[0257] According to an embodiment of this application, a method for determining a sequence number is provided. The network device determines the RLC sequence number corresponding to the first data packet based on the PDCP sequence number corresponding to the first data packet, thereby making the processing of the sequence number consistent between the RLC layer and the PDCP layer of the network device. When a network device failure occurs, the RLC layer of the terminal device will not receive the first data packet corresponding to the duplicate sequence number, but will discard the first data packet, thereby improving the reliability of communication.

[0258] for Figure 11 The problems mentioned can also be addressed using... Figure 10 The illustrated embodiment involves the network device sending instruction information to the terminal device, instructing the terminal device to perform RLC entity reconstruction or RLC entity reset. For details, please refer to... Figure 10 The embodiments shown are not described in detail here.

[0259] It is understood that, in the above embodiments, the methods and / or steps implemented by the terminal device can also be implemented by components (e.g., chips or circuits) that can be used in the terminal device; the methods and / or steps implemented by the first network device can also be implemented by components (e.g., chips or circuits) that can be used in the first network device; and the methods and / or steps implemented by the second network device can also be implemented by components (e.g., chips or circuits) that can be used in the second network device.

[0260] The above mainly describes the solutions provided by the embodiments of this application from the perspective of interaction between various network elements. Correspondingly, the embodiments of this application also provide a serial number indication / determination device, which is used to implement the various methods described above. This serial number indication / determination device can be a terminal device in the above method embodiments, or a device containing the above terminal device, or a component usable in a terminal device; or, the serial number indication / determination device can be a first network device in the above method embodiments, or a device containing the above first network device, or a component usable in a first network device. It is understood that, in order to implement the above functions, the serial number indication / determination device includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, in conjunction with the units and algorithm steps of the various examples described in the embodiments disclosed herein, the embodiments of this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed by hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this application.

[0261] This application embodiment can divide the serial number indication / determination device into functional modules according to the above method embodiment. For example, each function can be divided into a separate functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0262] Based on the same concept of the above-mentioned serial number indication method, such as Figure 13 As shown, a schematic diagram of a serial number indication device is also provided. This device 200 includes: a receiving unit 21 and a transmitting unit 22; wherein:

[0263] The receiving unit 21 is configured to receive first indication information from the first network device, wherein the first indication information is configured to instruct the first terminal device to report a first sequence number in the Radio Link Control (RLC) entity;

[0264] The sending unit 22 is configured to send a first sequence number in the RLC entity to the first network device according to the first indication information; wherein the first sequence number is used to indicate the starting sequence number in the RLC entity of the first network device.

[0265] The receiving unit 21 and transmitting unit 22 described above can be configured separately or combined into a single transceiver unit. Exemplarily, the device 200 can be a device, or a chip or other combined device or component with the functions of the device. When the device 200 is a device, the transceiver unit can be a transceiver, which may include an antenna and radio frequency circuitry. The device may also include a processing unit. The processing unit can be a processor (or processing circuitry), such as a baseband processor, which may include one or more central processing units (CPUs). When the device 200 is a component with the aforementioned device functions, the transceiver unit can be a radio frequency unit, and the processing unit can be a processor (or processing circuitry), such as a baseband processor. When the device 200 is a chip system, the transceiver unit can be the input / output interface of a chip (e.g., a baseband chip), and the processing unit can be the processor (or processing circuitry) of the chip system, which may include one or more central processing units. It should be understood that the processing unit in the embodiments of this application can be implemented by a processor or processor-related circuit components (or, processing circuitry), and the transceiver unit can be implemented by a transceiver or transceiver-related circuit components. The receiving unit described below is similar to the transmitting unit.

[0266] For details on the implementation of the aforementioned receiving unit 21 and transmitting unit 22, please refer to [reference needed]. Figure 7 The description of the first terminal device in the serial number indication method shown.

[0267] According to an embodiment of this application, a sequence number indicating device is provided. The device reports a first sequence number in an RLC entity according to an instruction from a first network device. The first network device can determine the starting sequence number in its RLC entity based on the first sequence number, so that the sequence numbers of the first network device and the RLC entity in the device are aligned. Thus, when the device receives data packets sent by the first network device, it can accurately merge them based on the aligned sequence numbers, thereby improving the reliability of communication.

[0268] Based on the same concept of the above-mentioned serial number indication method, such as Figure 14As shown, a schematic diagram of a serial number indication device is also provided. This device 300 includes: a transmitting unit 31, a receiving unit 32, and a processing unit 33; wherein:

[0269] The sending unit 31 is used to send first indication information to the first terminal device, the first indication information being used to instruct the first terminal device to report the first sequence number in the Radio Link Control (RLC) entity;

[0270] Receiving unit 32 is configured to receive a first serial number from the RLC entity of the first terminal device; and

[0271] Processing unit 33 is configured to determine the starting sequence number in the RLC entity of the first network device based on the first sequence number.

[0272] For details on the implementation of the aforementioned transmitting unit 31, receiving unit 32, and processing unit 33, please refer to [reference needed]. Figure 7 The description of the first network device in the indicated serial number method.

[0273] According to an embodiment of this application, a sequence number indicating device is provided. A first terminal device reports a first sequence number in an RLC entity according to the device's instruction. The device can determine the starting sequence number in the RLC entity of a first network device based on the first sequence number, so that the sequence number of the device is aligned with the sequence number of the RLC entity in the first terminal device. Thus, when the first terminal device receives data packets sent by the device, it can accurately merge them based on the aligned sequence number, thereby improving the reliability of communication.

[0274] Based on the same concept of the above-mentioned serial number indication method, such as Figure 15 As shown, a schematic diagram of a serial number indicating device is also provided. This device 400 includes: a receiving unit 41 and a processing unit 42; wherein:

[0275] Receiving unit 41 is configured to receive first information from a second network device, the first information including a second sequence number; and

[0276] Processing unit 42 is configured to determine the starting sequence number in the RLC entity of the first network device based on the second sequence number.

[0277] For details on the implementation of the receiving unit 41 and the processing unit 42, please refer to [reference needed]. Figure 8 The description of the first network device in the indicated serial number method.

[0278] According to an embodiment of this application, a serial number indicating device is provided. When a second network device is not malfunctioning, it sends a second serial number to the device. The device determines the starting serial number in the RLC entity of the device based on the second serial number. Thus, when the second network device malfunctions and the device takes over the second network device, the serial number of the device can be aligned with that of the RLC entity in the first terminal device. When the first terminal device receives data packets sent by the device, it can accurately merge them based on the aligned serial number, thereby improving the reliability of communication.

[0279] Based on the same concept of the above-mentioned serial number indication method, such as Figure 16 As shown, a schematic diagram of a serial number indication device is also provided. This device 500 includes: a transmitting unit 51; wherein:

[0280] The sending unit 51 is configured to send first information to the first network device, the first information including a second sequence number, the second sequence number being used to indicate the starting sequence number in the RLC entity of the first network device.

[0281] Optionally, the sending unit 51 is specifically used to send the first information to the first network device when the maximum sequence number in the RLC entity of the device is updated.

[0282] For details on the implementation of the above, please refer to [link / reference]. Figure 8 The description of the second network device in the indicated serial number method.

[0283] According to an embodiment of this application, a serial number indicating device sends a second serial number to a first network device when no fault occurs. The first network device determines the starting serial number in the RLC entity of the first network device based on the second serial number. Thus, when the device fails and the first network device takes over the device, the serial numbers of the RLC entities in the first network device and the first terminal device can be aligned. When the first terminal device receives data packets sent by the first network device, it can accurately merge them according to the aligned serial numbers, thereby improving the reliability of communication.

[0284] Based on the same concept of the above-mentioned serial number indication method, such as Figure 17 As shown, a schematic diagram of a serial number indication device is also provided. This device 600 includes: a transmitting unit 61, and may further include a processing unit 62; wherein:

[0285] The sending unit 61 is used to periodically send second information to the first network device, the second information including a first sequence number in the RLC entity, the first sequence number being used to indicate the starting sequence number in the RLC entity of the first network device.

[0286] Optionally, the processing unit 62 is used to start a timer; the sending unit 61 is specifically used to send the second information to the first network device after the timer expires; and the processing unit 62 is also used to restart the timer.

[0287] For details regarding the specific implementation of the aforementioned sending unit 61 and processing unit 62, please refer to [reference needed]. Figure 9 The description of the first terminal device in the serial number indication method shown.

[0288] According to an embodiment of this application, a sequence number indicating device periodically sends a first sequence number in an RLC entity to a first network device. The first network device can determine the starting sequence number in its RLC entity based on the first sequence number, so that the sequence numbers of the first network device and the RLC entity in the device are aligned. Thus, when the device receives data packets sent by the first network device, it can accurately merge them based on the aligned sequence numbers, thereby improving the reliability of communication.

[0289] Based on the same concept of the above-mentioned serial number indication method, such as Figure 18 As shown, a schematic diagram of a serial number indicating device is also provided. This device 700 includes: a receiving unit 71 and a processing unit 72; wherein:

[0290] The receiving unit 71 is configured to receive second information periodically sent by the first terminal device, the second information including a first sequence number in the RLC entity; and the processing unit 72 is configured to determine the starting sequence number in the RLC entity of the first network device based on the first sequence number.

[0291] For details on the implementation of the aforementioned receiving unit 71 and processing unit 72, please refer to [reference needed]. Figure 9 The description of the first network device in the indicated serial number method.

[0292] According to an embodiment of this application, a serial number indicating device is provided. A first terminal device periodically sends a first serial number in an RLC entity to the device. The device can determine the starting serial number in the RLC entity of the device based on the first serial number, so that the serial numbers of the device and the RLC entity in the first terminal device are aligned. Thus, when the first terminal device receives data packets sent by the device, it can accurately merge them based on the aligned serial numbers, thereby improving the reliability of communication.

[0293] Based on the same concept of the above-mentioned serial number indication method, such as Figure 19 As shown, a schematic diagram of a serial number indicating device is also provided. This device 800 includes: a receiving unit 81 and a processing unit 82; wherein:

[0294] The receiving unit 81 is configured to receive third indication information from the first network device, the third indication information being used to instruct the RLC entity to rebuild or reset; and the processing unit 82 is configured to perform at least one of the following operations based on the third indication information: RLC variable initialization, RLC timer initialization, RLC entity buffer clearing, or packet dropping.

[0295] For details on the implementation of the aforementioned receiving unit 81 and processing unit 82, please refer to [reference needed]. Figure 10 The description of the first network device in the indicated serial number method.

[0296] According to an embodiment of this application, a sequence number indication device is provided. The device performs RLC variable initialization, RLC entity buffer clearing, or data packet discarding based on the indication information of a first network device, so that the device is aligned with the sequence number of the RLC entity in the first network device. Thus, when the device receives data packets sent by the first network device, it can accurately merge them according to the aligned sequence number, thereby improving the reliability of communication.

[0297] Based on the same concept of the above-mentioned serial number indication method, such as Figure 20 As shown, a schematic diagram of a serial number indication device is also provided. This device 900 includes: a transmitting unit 91, and may further include a processing unit 92 (shown as dashed lines in the figure); wherein:

[0298] The sending unit 91 is used to send third indication information to the first terminal device, the third indication information being used to instruct the RLC entity to rebuild or reset.

[0299] Optionally, the processing unit 92 is further configured to detect a failure in the second network device, which was the network device that communicated with the first terminal device before the failure occurred.

[0300] For details regarding the specific implementation of the aforementioned sending unit 91 and processing unit 92, please refer to [reference needed]. Figure 10 The description of the first network device in the indicated serial number method.

[0301] According to an embodiment of this application, a sequence number indication device is provided. A first terminal device performs RLC variable initialization, RLC entity buffer clearing, or data packet discarding according to the indication information of the device, so that the sequence number of the first terminal device is aligned with that of the RLC entity in the device. Thus, when the first terminal device receives data packets sent by the device, it can accurately merge them according to the aligned sequence number, thereby improving the reliability of communication.

[0302] Based on the same concept of the above-mentioned serial number indication method, such as Figure 21As shown, a schematic diagram of a serial number determination device is also provided. The device 1000 includes: a processing unit 1001 and a sending unit 1002; wherein:

[0303] Processing unit 1001 is configured to determine a first data packet; processing unit 1001 is further configured to determine the Radio Link Control (RLC) sequence number corresponding to the first data packet based on the Packet Data Convergence Protocol (PDCP) sequence number corresponding to the first data packet; processing unit 1001 is further configured to add the RLC sequence number to the RLC header corresponding to the first data packet; and sending unit 1002 is configured to send the first data packet.

[0304] Optionally, the sending unit 1002 is further configured to send a second indication information to the terminal device, the second indication information being used to indicate that a data packet corresponding to at least one RLC sequence number cannot be sent or to indicate that the terminal device ignores the reception of the data packet corresponding to the at least one RLC sequence number.

[0305] For details on the implementation of the aforementioned processing unit 1001 and sending unit 1002, please refer to [reference needed]. Figure 12 The description of the network device in the serial number indication method shown.

[0306] According to an embodiment of this application, a sequence number determination device determines the RLC sequence number corresponding to the first data packet based on the PDCP sequence number corresponding to the first data packet. This ensures that the RLC layer and PDCP layer of the device process the sequence number in a consistent manner. In the event of a network device failure, the RLC layer of the terminal device will not receive the first data packet corresponding to a duplicate sequence number, but will discard the first data packet, thereby improving the reliability of communication.

[0307] Based on the same concept of the above-mentioned serial number indication method, such as Figure 22 As shown, a schematic diagram of a serial number determination device is also provided. This device 2000 includes a receiving unit 2001 and may further include a processing unit 2002 (shown as dashed lines in the figure); wherein...

[0308] The receiving unit 2001 is configured to receive a first data packet from a network device. The RLC header of the first data packet includes an RLC sequence number, and the RLC sequence number corresponding to the first data packet is determined based on the Packet Data Convergence Protocol (PDCP) sequence number corresponding to the first data packet.

[0309] Optionally, the receiving unit 2001 is further configured to receive second indication information from the network device, the second indication information being used to indicate that a data packet corresponding to at least one RLC sequence number cannot be sent or to indicate that the reception of the data packet corresponding to the at least one RLC sequence number should be ignored; and the processing unit 2002 is configured to determine, based on the second indication information, to ignore the data packet corresponding to the at least one RLC sequence number that cannot be sent and to continue sliding the receiving window backward.

[0310] For details on the specific implementation of the aforementioned receiving unit 2001 and processing unit 2002, please refer to [reference needed]. Figure 12 The description of the terminal device in the serial number indication method shown.

[0311] According to an embodiment of this application, a sequence number determination device is provided. The network device determines the RLC sequence number corresponding to the first data packet based on the PDCP sequence number corresponding to the first data packet. This makes the processing of sequence numbers by the RLC layer and PDCP layer of the network device consistent. When a network device failure occurs, the RLC layer of the device will not receive the first data packet corresponding to the duplicate sequence number, but will discard the first data packet, thereby improving the reliability of communication.

[0312] It should be noted that at least one of the above units can be implemented by software, hardware, or a combination of both. When any of the above units is implemented by software, the software exists as computer program instructions and is stored in memory. The processor can be used to execute the program instructions and implement the above method flow. The processor can be built into a system-on-chip (SoC) or ASIC, or it can be a separate semiconductor chip. In addition to the core that executes the software instructions for computation or processing, the processor may further include necessary hardware accelerators, such as field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), or logic circuits that implement dedicated logic operations.

[0313] When the above units or components are implemented in hardware, the hardware can be any one or any combination of a central processing unit (CPU), microprocessor, digital signal processing (DSP) chip, microcontroller unit (MCU), artificial intelligence processor, ASIC, SoC, FPGA, PLD, application-specific digital circuit, hardware accelerator, or non-integrated discrete device, which can run the necessary software or perform the above method flow independently of software.

[0314] Optionally, embodiments of this application also provide a chip system, including: at least one processor and an interface, wherein the at least one processor is coupled to a memory via the interface, and when the at least one processor executes a computer program or instructions in the memory, the method in any of the above method embodiments is executed. Optionally, the chip system may be composed of chips, or may include chips and other discrete devices; embodiments of this application do not specifically limit this.

[0315] It should be understood that in the description of the embodiments of this application, unless otherwise stated, " / " indicates that the objects before and after are in an "or" relationship. For example, A / B can represent A or B; where A and B can be singular or plural. Furthermore, in the description of the embodiments of this application, unless otherwise stated, "multiple" refers to two or more. "At least one of the following" or similar expressions refer 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, ab, ac, bc, or abc, where a, b, and c can be single or multiple. Additionally, to facilitate a clear description of the technical solutions of the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and the terms "first" and "second" do not necessarily imply difference. In this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being better or more advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner to facilitate understanding.

[0316] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software programs, implementation can be entirely or partially in the form of a computer program product. This computer program product includes at least one computer instruction. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. 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. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that can be integrated with the medium. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state disks (SSDs)).

[0317] Although embodiments of this application have been described herein in conjunction with various examples, those skilled in the art, by reviewing the accompanying drawings, disclosure, and appended claims, can understand and implement other variations of the disclosed embodiments in carrying out the claimed embodiments. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0318] Although embodiments of this application have been described in conjunction with specific features and examples, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of the embodiments of this application. Accordingly, this specification and drawings are merely exemplary illustrations of the embodiments of this application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of the embodiments of this application. Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of the embodiments of this application. Thus, if these modifications and variations of the embodiments of this application fall within the scope of the claims of the embodiments of this application and their equivalents, then the embodiments of this application are also intended to include these modifications and variations.

Claims

1. A method for indicating a serial number, characterized in that, include: The first terminal device receives first indication information from the first network device. The first indication information is used to instruct the first terminal device to report the first sequence number corresponding to the RLC Service Data Unit (SDU) segment in the Radio Link Control (RLC) entity. The RLC SDU segment is received by the first terminal device from the second network device. The second network device is the network device that communicated with the first terminal device before the fault occurred, and the first network device is the network device that communicated with the first terminal device after the fault occurred. The fault was detected by the first network device. The first terminal device sends the first sequence number in the RLC entity to the first network device according to the first instruction information; Wherein, the first sequence number is the SN value corresponding to the upper boundary of the RLC receiving window of the first terminal device and is used to indicate the starting sequence number in the RLC entity of the first network device.

2. A method for indicating a serial number, characterized in that, include: The first network device detects that the second network device has malfunctioned. The second network device is the network device that was communicating with the first terminal device before the malfunction occurred. The first network device sends a first indication message to the first terminal device. The first indication message is used to instruct the first terminal device to report the first sequence number corresponding to the RLC Service Data Unit (SDU) segment in the Radio Link Control (RLC) entity. The RLC SDU segment is received by the first terminal device from the second network device. The first network device receives a first serial number from the RLC entity of the first terminal device; The first network device determines the starting sequence number in the RLC entity of the first network device based on the first sequence number, where the first sequence number is the SN value corresponding to the upper boundary of the RLC receiving window of the first terminal device.

3. A method for determining a serial number, characterized in that, include: The network device determines the first data packet; The network device determines the Radio Link Control (RLC) sequence number corresponding to the first data packet based on the Packet Data Convergence Protocol (PDCP) sequence number corresponding to the first data packet. The network device adds the RLC sequence number to the RLC header corresponding to the first data packet; The network device sends the first data packet; The network device sends a second indication message to the terminal device, the second indication message being used to indicate that a data packet corresponding to at least one RLC sequence number preceding the first data packet cannot be sent or to indicate that the terminal device ignores receiving the data packet corresponding to the at least one RLC sequence number.

4. The method according to claim 3, characterized in that, The network device determines the RLC sequence number corresponding to the first data packet based on the PDCP sequence number corresponding to the first data packet, including: the RLC sequence number is equal to the PDCP sequence number, or the offset value between the RLC sequence number and the PDCP sequence number is N, where N is an integer.

5. The method according to claim 3, characterized in that, The second indication information is contained in the RLC control protocol data unit (PDU); Alternatively, the second indication information may be contained in an RLC data PDU, wherein the RLC data PDU contains only a header.

6. A method for determining a serial number, characterized in that, include: The terminal device receives a first data packet from the network device. The RLC header of the first data packet includes an RLC sequence number. The RLC sequence number corresponding to the first data packet is determined based on the Packet Data Convergence Protocol (PDCP) sequence number corresponding to the first data packet. The terminal device receives a second indication information from the network device, the second indication information being used to indicate that a data packet corresponding to at least one RLC sequence number preceding the first data packet cannot be sent or to indicate that the terminal device ignores the reception of the data packet corresponding to the at least one RLC sequence number; The terminal device determines, based on the second indication information, to ignore the data packets corresponding to the at least one RLC sequence number that cannot be sent and continues to slide the receiving window backward.

7. The method according to claim 6, characterized in that, The RLC sequence number corresponding to the first data packet is equal to the PDCP sequence number corresponding to the first data packet, or the offset between the RLC sequence number corresponding to the first data packet and the PDCP sequence number corresponding to the first data packet is N, where N is an integer.

8. The method according to claim 6, characterized in that, The second indication information is at least one of the following: RLC control protocol data unit (PDU) or RLC data PDU, wherein the RLC data PDU contains only a header or only an RLCSN number.

9. A first terminal device, characterized in that, The first terminal device includes: The receiving unit is configured to receive first indication information from a first network device. The first indication information is configured to instruct the first terminal device to report a first sequence number corresponding to an RLC Service Data Unit (SDU) segment in a Radio Link Control (RLC) entity. The RLC SDU segment is received by the first terminal device from a second network device. The second network device is the network device that communicated with the first terminal device before the fault occurred, and the first network device is the network device that communicated with the first terminal device after the fault occurred. The fault was detected by the first network device. A sending unit is configured to send the first sequence number in the RLC entity to the first network device according to the first indication information; Wherein, the first sequence number is the SN value corresponding to the upper boundary of the RLC receiving window of the first terminal device and is used to indicate the starting sequence number in the RLC entity of the first network device.

10. A first network device, characterized in that, The first network device includes: A processing unit is configured to detect a fault in a second network device, the second network device being the network device that communicated with the first terminal device before the fault occurred. The sending unit is configured to send first indication information to the first terminal device. The first indication information is configured to instruct the first terminal device to report the first sequence number corresponding to the RLC Service Data Unit (SDU) segment in the Radio Link Control (RLC) entity. The RLC SDU segment is received by the first terminal device from the second network device. The receiving unit is configured to receive a first serial number from the RLC entity of the first terminal device; The processing unit is further configured to determine the starting sequence number in the RLC entity of the first network device based on the first sequence number, wherein the first sequence number is the SN value corresponding to the upper boundary of the RLC receiving window of the first terminal device.

11. A serial number determining device, characterized in that, include: Processing unit, used to determine the first data packet; The processing unit is further configured to determine the Radio Link Control (RLC) sequence number corresponding to the first data packet based on the Packet Data Convergence Protocol (PDCP) sequence number corresponding to the first data packet; The processing unit is further configured to add the RLC sequence number to the RLC header corresponding to the first data packet; A sending unit is configured to send the first data packet; The sending unit is further configured to send a second indication information to the terminal device, the second indication information being used to indicate that a data packet corresponding to at least one RLC sequence number preceding the first data packet cannot be sent or to indicate that the terminal device ignores the reception of the data packet corresponding to the at least one RLC sequence number.

12. The apparatus according to claim 11, characterized in that, The RLC serial number is equal to the PDCP serial number, or the offset between the RLC serial number and the PDCP serial number is N, where N is an integer.

13. The apparatus according to claim 11, characterized in that, The second indication information is contained in the RLC control protocol data unit (PDU); or the second indication information is contained in the RLC data PDU, wherein the RLC data PDU contains only a header.

14. A serial number determining device, characterized in that, include: The receiving unit is configured to receive a first data packet from a network device. The RLC header of the first data packet includes an RLC sequence number, and the RLC sequence number corresponding to the first data packet is determined based on the Packet Data Convergence Protocol (PDCP) sequence number corresponding to the first data packet. The receiving unit is further configured to receive second indication information from the network device, the second indication information being configured to indicate that data packets corresponding to at least one RLC sequence number preceding the first data packet cannot be sent or to indicate that the reception of data packets corresponding to the at least one RLC sequence number should be ignored; The device further includes: The processing unit is configured to determine, based on the second indication information, to ignore the data packets corresponding to the at least one RLC sequence number that cannot be sent and to continue sliding the receiving window backward.

15. The apparatus according to claim 14, characterized in that, The RLC sequence number corresponding to the first data packet is equal to the PDCP sequence number corresponding to the first data packet, or the offset between the RLC sequence number corresponding to the first data packet and the PDCP sequence number corresponding to the first data packet is N, where N is an integer.

16. The apparatus according to claim 14, characterized in that, The second indication information is contained in the RLC control protocol data unit (PDU); or the second indication information is contained in the RLC data PDU, wherein the RLC data PDU contains only a header.

17. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store a computer program that, when run on a computer, causes the computer to perform the method as claimed in claim 1, or causes the computer to perform the method as claimed in claim 2, or causes the computer to perform the method as claimed in any one of claims 3 to 5, or causes the computer to perform the method as claimed in any one of claims 6 to 8.

18. A chip, characterized in that, The device includes a processor and a communication interface, wherein the processor is configured to read instructions to execute the method as claimed in claim 1, or to execute the method as claimed in claim 2, or to execute the method as claimed in any one of claims 3 to 5, or to execute the method as claimed in any one of claims 6 to 8.

19. A network device, characterized in that, The device includes a processor connected to a memory for storing a computer program, the processor for executing the computer program stored in the memory to cause the device to perform the method as claimed in claim 1, or the method as claimed in claim 2, or the method as claimed in any one of claims 3 to 5, or the method as claimed in any one of claims 6 to 8.

20. A communication system, characterized in that, It includes the first terminal device as described in claim 9, and the first network device as described in claim 10.

21. A communication system, characterized in that, The device includes the serial number determining device according to any one of claims 11 to 13, and the serial number determining device according to any one of claims 14 to 16.

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