A communication method and a communication device

Abstract

The present application relates to a communication method and a communication device, in which a terminal device receives first information from a network device, wherein the first information includes information of a first HFN and information of a first SN, or information of the first HFN and information of an SN range, or information of a COUNT range; receives a first PDCP PDU from the network device, wherein the first PDCP PDU includes a second SN; and determines the HFN of the first PDCP PDU according to the first information and the second SN. With this method, the terminal device can determine the HFN of the first PDCP PDU according to the first information provided by the network device, so that the terminal device and the network device can align the HFN of the PDCP PDU, thereby helping to improve reliability.

Description

Technical Field

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

[0002] Currently, wireless communication systems are widely deployed to provide various types of communications, such as voice services, data services, etc. The communication system includes one or more terminal devices connected to the core network through an access network to achieve communication between multiple communication devices. In some scenarios, such as the new radio (NR) multicast broadcast scenario, high reliability requirements are placed on data service transmission.

[0003] In the prior art, when performing unicast communication, the receiving end and the transmitting end can use the same initial value of the hyperframe number (HFN) to communicate, so that the sending and receiving sides can perform subsequent HFN maintenance based on the same initial value of the HFN and the same mechanism. However, in some scenarios, such as multicast broadcast service communication scenarios, when the terminal device starts to receive a multicast service, the network device may have transmitted the multicast service for a period of time, and the terminal device cannot determine the HFN used by the network device, making it impossible to align the HFN between the terminal device and the network device. Summary of the invention

[0004] The present application provides a communication method and device, which can improve the reliability of data communication.

[0005] In a first aspect, an embodiment of the present application provides a communication method, which is applied to a terminal device or a chip inside a terminal device. In the method, the terminal device receives first information from a network device, the first information including any one of the following: information of a first HFN and information of a first SN; or information of the first HFN and information of an SN range; or information of a COUNT range; receives a first PDCP PDU from the network device, the first PDCP PDU including a second SN; determines the HFN of the first PDCP PDU according to the first information and the second SN.

[0006] In this scheme, the terminal device receives the first information from the network device, and determines the HFN corresponding to the first PDCP PDU according to the first information and the second SN information carried in the received PDCP PDU; so that the terminal device and the network device can align the HFN or the initial value of the HFN of the PDCP PDU. The normal reception of data is guaranteed, and the packet loss or disordered delivery caused by HFN misalignment is avoided, which helps to improve reliability. In addition, it may also be beneficial to the decryption and integrity verification on the terminal device side, avoiding the packet loss problem caused by unsuccessful integrity verification, and improving reliability. In addition, compared with the scheme in which the terminal device sets RX_DELIV to the COUNT provided by the network device, the above method can avoid the problem of data packet loss and / or receiving side window jamming due to unreasonable COUNT setting (for example, because some data failed to be successfully received, the window cannot slide, resulting in the inability to deliver data to the upper layer, increasing communication delay), improves the reliability of data reception, improves communication efficiency, and reduces communication delay.

[0007] In a possible implementation manner, the first information includes information of a first HFN and information of a first SN, and determining the HFN of the first PDCP PDU according to the first information and the second SN includes any one or more of the following:

[0008] If the second SN is less than the difference between the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN plus 1; if the second SN is greater than or equal to the sum of the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN minus 1; if the second SN is greater than or equal to the difference between the first SN and the first parameter, and / or the second SN is less than the sum of the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN.

[0009] In another possible implementation manner, the first information includes: information of a first HFN and information of an SN range, and determining the HFN of the first PDCP PDU according to the first information and the second SN includes any one or more of the following:

[0010] If the second SN is within the SN range, the HFN of the first PDCP PDU is equal to the first HFN; if the second SN is less than the minimum value within the SN range, the HFN of the first PDCP PDU is equal to the first HFN plus 1; if the second SN is greater than the maximum value within the SN range, the HFN of the first PDCP PDU is equal to the first HFN minus 1.

[0011] Optionally, the information of the SN range includes information of the third SN and information of the fourth SN. It can be understood that the information of the SN range can be determined by the information of the third SN and the information of the fourth SN. In a possible implementation, the information of the third SN is the lower boundary of the SN range (or the minimum value in the SN range), and the information of the fourth SN is the upper boundary of the SN range (or the maximum value in the SN range).

[0012] Optionally, the minimum value in the SN range is 0; Optionally, the maximum value in the SN range is 2 X-1 , where X represents the number of bits corresponding to the SN length.

[0013] In another possible implementation manner, the first information includes information of a COUNT range, and determining the HFN of the first PDCP PDU according to the first information and the second SN includes any one or more of the following:

[0014] If the second SN is greater than or equal to the SN corresponding to the minimum value in the COUNT range, the HFN of the first PDCP PDU is equal to the HFN corresponding to the minimum value in the COUNT range; if the second SN is less than or equal to the SN corresponding to the maximum value in the COUNT range, the HFN of the first PDCP PDU is equal to the HFN corresponding to the maximum value in the COUNT range.

[0015] The COUNT range information includes: the first COUNT information and the second COUNT information. It can be understood that the COUNT range can be determined by the first COUNT information and the second COUNT information. There are many ways to implement the first COUNT information and the second COUNT information:

[0016] In a possible design, the information of the first COUNT and the information of the second COUNT include: information of the first HFN, information of the second HFN and information of the fifth SN. In this manner, the information of the fifth SN is shared. For example, the default terminal device can use the information of the fifth SN to perform calculations with the information of the first HFN and the information of the second HFN, respectively, to obtain the information of the first COUNT and the second COUNT. Therefore, the network device does not need to repeatedly indicate the information of the fifth SN, thereby saving signaling overhead.

[0017] In another possible design, the information of the first COUNT and the information of the second COUNT include: information of the first HFN, information of the second HFN, information of the sixth SN, and information of the seventh SN. In this manner, the information of the first HFN includes information of its corresponding SN (e.g., information of the sixth SN or information of the seventh SN), and the information of the second HFN also includes information of its corresponding SN (e.g., information of the seventh SN or information of the sixth SN). The information of which SN the above HFN information corresponds to may be indicated by a network device or predefined by a protocol. For example, the information order of the default HFN is the same as the information order of the corresponding SN, or the information of the first SN after the information of the default HFN includes information of the corresponding SN.

[0018] In another possible design, the information of the first COUNT and the information of the second COUNT include: information of the first COUNT and information of the eighth SN. In this manner, the HFN information corresponding to the first COUNT is shared. For example, the default terminal device can use the HFN information corresponding to the first COUNT and the information of the eighth SN to perform calculations to obtain the information of the second COUNT. Therefore, the network device does not need to repeatedly indicate the HFN information corresponding to the second COUNT, thereby saving signaling overhead.

[0019] In a possible implementation manner, the first information is carried in a radio resource control RRC message, or a broadcast message, or a radio bearer configuration or a PDCP control PDU corresponding to the first PDCP PDU.

[0020] In a possible implementation manner, the method further includes: before receiving the first information from the network device, sending a request message to the network device, where the request message is used to request the first information.

[0021] In this way, the terminal device can send a request message to the network device to inform the network device of its own demand for the first information. Correspondingly, the network device can send the first information based on the request message sent by the terminal device. On the one hand, this makes the way for the terminal device to obtain the first information more flexible. On the other hand, it can avoid the waste of resources caused by the network device sending the first information to unnecessary terminal devices.

[0022] In one possible implementation, the method also includes: setting a first state variable according to one of the following methods: setting the minimum or maximum value between the COUNT of the first PDCP PDU received and the COUNT corresponding to the first information to the first state variable; setting the minimum or maximum value between the COUNT of the N PDCP PDUs received to the first state variable, where N is a positive integer; setting the minimum or maximum value between the COUNT of the N PDCP PDUs received and the COUNT corresponding to the first information to the first state variable, where N is a positive integer; setting the minimum or maximum value between the COUNT of the PDCP PDUs received within a first time period T to the first state variable; setting the minimum or maximum value between the COUNT of the PDCP PDUs received within the first time period T and the COUNT corresponding to the first information to the first state variable.

[0023] In one possible implementation, any one or more of the first PDCP PDU, the first received PDCP PDU, the N received PDCP PDUs, the PDCP PDUs received within the first time period T, and the first information is associated with a first PDCP entity or a first radio bearer.

[0024] In a possible implementation manner, the first PDCP entity and / or the first radio bearer is associated with a first service, and the first service includes a broadcast service and / or a multicast service.

[0025] In a possible implementation, the first PDCP PDU includes the first PDCP PDU received by the terminal device.

[0026] In a second aspect, a communication method is provided, which is applied to a network device or a chip inside the network device. In the method, the network device sends first information to a terminal device, where the first information includes any of the following: information about a first HFN and information about a first SN; or information about the first HFN and information about an SN range; or information about a COUNT range; and sends a first PDCP PDU to the terminal device, where the first PDCP PDU includes a second SN. For possible implementations and technical effects of the first information, refer to the description related to the first aspect.

[0027] In a possible implementation, before the network device sends the first information to the terminal device, the method further includes: receiving a request message sent by the terminal device, where the request message is used to request the first information.

[0028] Optionally, the request message is carried in a radio resource control RRC message, or a broadcast message, or downlink control information DCI, or a media access control control element MAC CE, or a message in a random access process.

[0029] Optionally, the message in the random access process includes: the first message of the random access process (for example, Msg1 or MsgA), or the third message of the random access process (for example, Msg3).

[0030] In one possible implementation, the network device counts a first quantity, and the first quantity includes: the number of request messages received by the network device; or the number of terminal devices requesting the first information; if a first preset condition is met, the network device sends the first information in a broadcast and / or multicast manner; if the first preset condition is not met, the network device sends the first information in a unicast manner, wherein the first preset condition may be: the first quantity is not greater than or less than a preset quantity.

[0031] In this way, when there are fewer terminal devices requesting to obtain the first information, the network device can use unicast to send the first information, thereby avoiding unnecessary information reception by the terminal device; when there are more terminal devices requesting the first information, the network device can use broadcast and / or multicast to send the first information, thereby avoiding the waste of resources caused by excessive unicast sending of the first information.

[0032] For the technical effects brought about by some possible implementation methods of the second aspect, reference may be made to the introduction to the technical effects of the first aspect or the corresponding implementation methods of the first aspect.

[0033] In a third aspect, a communication method is provided, which is applied to a terminal device or a chip inside the terminal device. In the method, the terminal device receives a PDCP PDU from a network device; the terminal device receives first indication information from the network device, the first indication information is used to indicate whether there is HFN information in the PDCP PDU, or to indicate whether there is COUNT information in the PDCP PDU; or,

[0034] The first indication information is used to indicate a PDCP PDU format type, the format type includes a first type and / or a second type, the PDCP PDU corresponding to the first type includes HFN information or COUNT information, and the PDCP PDU corresponding to the second type does not include the HFN information or COUNT information; or,

[0035] The first indication information is used to indicate whether there is HFN information or COUNT information before or after the first indication information in the PDCP PDU; or,

[0036] The first indication information is used to indicate whether there is HFN information or COUNT information before or after the indication field of the PDCP PDU;

[0037] The indication field includes at least one of the following information: SN, reserved bit R, PDU type, data, and integrity message authentication code MAC-I.

[0038] In one possible implementation, the terminal device sends capability information to the network device, where the capability information is used to indicate whether the terminal device supports format type conversion, or to indicate the format types supported by the terminal device, or to indicate whether the terminal device only supports the first type.

[0039] In a possible implementation, second indication information is received from the network device, where the second indication information is used to indicate whether the network device supports format type conversion, or to indicate the format types supported by the network device, or to indicate whether the network device only supports the first type.

[0040] In a possible implementation manner, the first indication information is carried in a radio resource control RRC message, or a PDCP control PDU, or the PDCP PDU or a radio bearer configuration corresponding to the PDCP PDU.

[0041] In a possible implementation, any one or more of the first indication information, the second indication information, and the format type corresponds to a first PDCP entity or a first radio bearer.

[0042] In a possible implementation manner, the first PDCP entity and / or the first radio bearer is associated with a first service, and the first service includes a broadcast service and / or a multicast service.

[0043] In this way, on the one hand, by carrying HFN information or COUNT information in the PDCP PDU, the terminal device can quickly determine the HFN of the received PDCP PDU, and the HFN maintenance between the terminal device and the network device is more flexible, thereby improving the continuity and reliability of the service. On the other hand, by introducing the first indication information, the terminal device can know the PDCP PDU format in advance, which helps the terminal device to quickly parse the data packet.

[0044] In a fourth aspect, a communication method is provided, which is applied to a network device or a chip inside the network device. In the method, the network device sends a PDCP PDU to a terminal device; the network device sends first indication information to the terminal device, where the first indication information is used to indicate whether there is HFN information in the PDCP PDU, or to indicate whether there is COUNT information in the PDCP PDU; or,

[0045] The first indication information is used to indicate a PDCP PDU format type, the format type includes a first type and / or a second type, the PDCP PDU corresponding to the first type includes HFN information or COUNT information, and the PDCP PDU corresponding to the second type does not include the HFN information or COUNT information; or,

[0046] The first indication information is used to indicate whether there is HFN information or COUNT information before or after the first indication information in the PDCP PDU; or,

[0047] The first indication information is used to indicate whether there is HFN information or COUNT information before or after the indication field of the PDCP PDU;

[0048] The indication field includes at least one of the following information: SN, reserved bit R, PDU type, data, and integrity message authentication code MAC-I.

[0049] In one possible implementation, the network device receives capability information sent by the terminal device, where the capability information is used to indicate whether the terminal device supports format type conversion, or to indicate the format types supported by the terminal device, or to indicate whether the terminal device only supports the first type.

[0050] In one possible implementation, the network device sends second indication information to the terminal device, where the second indication information is used to indicate whether the network device supports format type conversion, or to indicate the format type supported by the network device, or to indicate whether the network device only supports the first type.

[0051] In a possible implementation manner, the first indication information is carried in a radio resource control RRC message, or a PDCP control PDU, or the PDCP PDU or a radio bearer configuration corresponding to the PDCP PDU.

[0052] In a possible implementation, any one or more of the first indication information, the second indication information, and the format type corresponds to a first PDCP entity or a first radio bearer.

[0053] In a possible implementation manner, the first PDCP entity and / or the first radio bearer is associated with a first service, and the first service includes a broadcast service and / or a multicast service.

[0054] Regarding the technical effects brought about by some possible implementation methods of the fourth aspect, reference may be made to the introduction to the technical effects of the second aspect or the corresponding implementation methods of the second aspect.

[0055] In a fifth aspect, a communication device is provided, the communication device is used to execute the method in the first aspect or any possible implementation of the first aspect. Specifically, the communication device may include a module for executing the method in the first aspect or any optional implementation of the first aspect, for example, including a sending module and a receiving module, and optionally, may also include a processing module. Exemplarily, the sending module and the receiving module may belong to a transceiver module, and the sending module and the receiving module may be different functional modules, or may also be the same functional module (that is, a transceiver module or a transceiver unit), but can realize the sending function and the receiving function. Exemplarily, the communication device is a communication device, or a chip or other component arranged in a communication device. Exemplarily, the communication device is a terminal device. For example, the transceiver module may also be implemented by a transceiver, and the processing module may also be implemented by a processor. Alternatively, the sending module may be implemented by a transmitter, and the receiving module may be implemented by a receiver. The transmitter and the receiver may be different functional modules, or may also be the same functional module (for example, a transceiver), but can realize the sending function and the receiving function. If the communication device is a communication device, the transceiver is implemented, for example, by an antenna, a feeder, and a codec in the communication device. Alternatively, if the communication device is a chip set in a communication device, then the transceiver (or, transmitter and receiver) is, for example, a communication interface in the chip, which is connected to a radio frequency transceiver component in the communication device to realize information transmission and reception through the radio frequency transceiver component.

[0056] The transceiver unit is used to receive first information from a network device, and the first information includes any one of the following:

[0057] Information of the first HFN and information of the first SN; or,

[0058] Information of the first HFN and information of the SN range; or,

[0059] COUNT range information;

[0060] The transceiver unit is further configured to receive a first PDCP PDU from the network device, wherein the first PDCP PDU includes a second SN;

[0061] A processing unit is configured to determine the HFN of the first PDCP PDU according to the first information and the second SN.

[0062] In a sixth aspect, a communication device is provided. The communication device is used to execute the method in the second aspect or any optional implementation of the second aspect. Specifically, the communication device may include a module for executing the method in the first aspect or any optional implementation of the first aspect, for example, including a sending module and a receiving module, and optionally, a processing module. Exemplarily, the sending module and the receiving module may belong to a transceiver module, and the sending module and the receiving module may be different functional modules, or may also be the same functional module (i.e., a transceiver module or a transceiver unit), but can realize the sending function and the receiving function. Exemplarily, the communication device is a communication device, or a chip or other component arranged in a communication device. Exemplarily, the communication device is a terminal device. For example, the transceiver module may also be implemented by a transceiver, and the processing module may also be implemented by a processor. Alternatively, the sending module may be implemented by a transmitter, and the receiving module may be implemented by a receiver. The transmitter and the receiver may be different functional modules, or may also be the same functional module (e.g., a transceiver), but can realize the sending function and the receiving function. If the communication device is a communication device, the transceiver is implemented, for example, by an antenna, a feeder, and a codec in the communication device. Alternatively, if the communication device is a chip set in a communication device, then the transceiver (or, transmitter and receiver) is, for example, a communication interface in the chip, which is connected to a radio frequency transceiver component in the communication device to realize information transmission and reception through the radio frequency transceiver component.

[0063] The transceiver unit is used to send first information to the terminal device, and the first information includes any one of the following:

[0064] Information of the first HFN and information of the first SN; or,

[0065] Information of the first HFN and information of the SN range; or,

[0066] COUNT range information;

[0067] The transceiver unit is also used to send a first PDCP PDU to the terminal device, where the first PDCP PDU includes a second SN.

[0068] In a seventh aspect, a communication device is provided, the communication device is used to execute the method in the third aspect or any possible implementation of the third aspect. Specifically, the communication device may include a module for executing the method in the first aspect or any optional implementation of the first aspect, for example, including a sending module and a receiving module, and optionally, may also include a processing module. Exemplarily, the sending module and the receiving module may belong to a transceiver module, and the sending module and the receiving module may be different functional modules, or may also be the same functional module (that is, a transceiver module or a transceiver unit), but can implement the sending function and the receiving function. Exemplarily, the communication device is a communication device, or a chip or other component arranged in a communication device. Exemplarily, the communication device is a terminal device. For example, the transceiver module may also be implemented by a transceiver, and the processing module may also be implemented by a processor. Alternatively, the sending module may be implemented by a transmitter, and the receiving module may be implemented by a receiver. The transmitter and the receiver may be different functional modules, or may also be the same functional module (for example, a transceiver), but can implement the sending function and the receiving function. If the communication device is a communication device, the transceiver is implemented, for example, by an antenna, a feeder, and a codec in the communication device. Alternatively, if the communication device is a chip set in a communication device, then the transceiver (or, transmitter and receiver) is, for example, a communication interface in the chip, which is connected to a radio frequency transceiver component in the communication device to realize information transmission and reception through the radio frequency transceiver component.

[0069] Wherein, the transceiver unit is used to receive the PDCP PDU from the network device;

[0070] The transceiver unit is further configured to receive first indication information from a network device, where the first indication information is used to indicate whether there is HFN information in the PDCP PDU, or to indicate whether there is COUNT information in the PDCP PDU; or,

[0071] The first indication information is used to indicate a PDCP PDU format type, the format type includes a first type and / or a second type, the PDCP PDU corresponding to the first type includes HFN information or COUNT information, and the PDCP PDU corresponding to the second type does not include the HFN information or COUNT information; or,

[0072] The first indication information is used to indicate whether there is HFN information or COUNT information before or after the first indication information in the PDCP PDU; or,

[0073] The first indication information is used to indicate whether there is HFN information or COUNT information before or after the indication field of the PDCP PDU;

[0074] The indication field includes at least one of the following information: SN, reserved bit R, PDU type, data, and integrity message authentication code MAC-I.

[0075] In an eighth aspect, a communication device is provided, the communication device is used to execute the method in the fourth aspect or any possible implementation of the fourth aspect. Specifically, the communication device may include a module for executing the method in the first aspect or any optional implementation of the first aspect, for example, including a sending module and a receiving module, and optionally, may also include a processing module. Exemplarily, the sending module and the receiving module may belong to a transceiver module, and the sending module and the receiving module may be different functional modules, or may also be the same functional module (that is, a transceiver module or a transceiver unit), but can implement the sending function and the receiving function. Exemplarily, the communication device is a communication device, or a chip or other component arranged in a communication device. Exemplarily, the communication device is a terminal device. For example, the transceiver module may also be implemented by a transceiver, and the processing module may also be implemented by a processor. Alternatively, the sending module may be implemented by a transmitter, and the receiving module may be implemented by a receiver. The transmitter and the receiver may be different functional modules, or may also be the same functional module (for example, a transceiver), but can implement the sending function and the receiving function. If the communication device is a communication device, the transceiver is implemented, for example, by an antenna, a feeder, and a codec in the communication device. Alternatively, if the communication device is a chip set in a communication device, then the transceiver (or, transmitter and receiver) is, for example, a communication interface in the chip, which is connected to a radio frequency transceiver component in the communication device to realize information transmission and reception through the radio frequency transceiver component.

[0076] The transceiver unit is used to send a PDCP PDU to a terminal device; the transceiver unit is also used to send first indication information to the terminal device, wherein the first indication information is used to indicate whether there is information of a first HFN in the PDCP PDU, or to indicate whether there is information of a COUNT in the PDCP PDU; or,

[0077] The first indication information is used to indicate a PDCP PDU format type, the format type includes a first type and / or a second type, the PDCP PDU corresponding to the first type includes HFN information or COUNT information, and the PDCP PDU corresponding to the second type does not include the HFN information or COUNT information; or,

[0078] The first indication information is used to indicate whether there is HFN information or COUNT information before or after the first indication information in the PDCP PDU; or,

[0079] The first indication information is used to indicate whether there is HFN information or COUNT information before or after the indication field of the PDCP PDU;

[0080] The indication field includes at least one of the following information: SN, reserved bit R, PDU type, data, and integrity message authentication code MAC-I.

[0081] In the ninth aspect, a communication device is provided. The communication device includes one or more processors, and optionally, may also include a communication interface, which may be used to communicate with other devices or equipment. Optionally, the communication device may also include one or more memories for storing computer instructions. One or more processors and one or more memories are coupled to each other to implement the method described in the first aspect or various optional embodiments of the first aspect or the third aspect or various optional embodiments of the third aspect. Alternatively, the communication device may not include a memory, and at least one memory may be located outside the communication device. One or more processors, one or more memories and a communication interface are coupled to each other to implement the method described in the first aspect or various optional embodiments of the first aspect or the third aspect or various optional embodiments of the third aspect. For example, the communication device may also include one or more computer programs, the one or more computer programs are stored in one or more memories, and the one or more computer programs include computer instructions. When one or more processors execute the computer instructions stored in the one or more memories, the communication device executes the method described in the first aspect or various optional embodiments of the first aspect or the third aspect or various optional embodiments of the third aspect. Exemplarily, the communication device is a communication device, or a chip or other component arranged in a communication device. Exemplarily, the communication device is a terminal device.

[0082] Wherein, if the communication device is a communication device, the communication interface is implemented, for example, by a transceiver (or a transmitter and a receiver) in the communication device, for example, the transceiver is implemented by an antenna, a feeder, and a codec, etc. in the communication device. Alternatively, if the communication device is a chip provided in the communication device, the communication interface is, for example, an input / output interface of the chip, such as an input / output pin, etc., and the communication interface is connected to a radio frequency transceiver component in the communication device to implement information transmission and reception through the radio frequency transceiver component.

[0083] In the tenth aspect, a communication device is provided. The communication device includes one or more processors, and optionally, may also include a communication interface, which may be used to communicate with other devices or equipment. Optionally, the communication device may also include one or more memories for storing computer instructions. One or more processors and one or more memories are coupled to each other to implement the method described in the second aspect or various optional embodiments of the second aspect or the fourth aspect or various optional embodiments of the fourth aspect. Alternatively, the communication device may not include a memory, and at least one memory may be located outside the communication device. One or more processors, one or more memories and a communication interface are coupled to each other to implement the method described in the second aspect or various optional embodiments of the second aspect or the fourth aspect or various optional embodiments of the fourth aspect. For example, the communication device may also include one or more computer programs, the one or more computer programs are stored in one or more memories, and the one or more computer programs include computer instructions. When one or more processors execute the computer instructions stored in the one or more memories, the communication device executes the method described in the second aspect or various optional embodiments of the second aspect or the fourth aspect or various optional embodiments of the fourth aspect. Exemplarily, the communication device is a communication device, or a chip or other component provided in a communication device. Exemplarily, the communication device is a network device, such as an access network device, such as a base station.

[0084] Wherein, if the communication device is a communication device, the communication interface is implemented, for example, by a transceiver (or a transmitter and a receiver) in the communication device, for example, the transceiver is implemented by an antenna, a feeder, and a codec, etc. in the communication device. Alternatively, if the communication device is a chip provided in the communication device, the communication interface is, for example, an input / output interface of the chip, such as an input / output pin, etc., and the communication interface is connected to a radio frequency transceiver component in the communication device to implement information transmission and reception through the radio frequency transceiver component.

[0085] In the eleventh aspect, a computer program product is provided, which includes: a computer program (also referred to as code, or instruction), which, when executed, enables a computer to execute a method in any one of the above aspects or any possible implementation of that aspect.

[0086] In the twelfth aspect, a computer-readable medium is provided, which stores a computer program (also referred to as code, or instruction) which, when executed on a computer, enables the computer to execute a method in any of the above aspects or any possible implementation of that aspect.

[0087] In the thirteenth aspect, a chip system is provided, which includes one or more processors and a communication interface, wherein the processor is coupled to the communication interface and is used to implement the method in any one of the above aspects or any possible implementation of that aspect.

[0088] Optionally, the chip system may further include a memory, for example, the processor may read and execute a software program stored in the memory to implement the method provided in the first aspect or any one of the optional implementations. Alternatively, the memory may not be included in the chip system, but may be located outside the chip system, which is equivalent to the processor reading and executing a software program stored in an external memory to implement the method in any one of the above aspects or any possible implementation of the aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Figure 1 A schematic diagram of a network architecture applicable to an embodiment of the present application;

[0090] Figure 2 A schematic diagram of another network architecture applicable to an embodiment of the present application;

[0091] Figure 3 A schematic diagram of another network architecture applicable to the embodiment of the present application;

[0092] Figure 4a A schematic diagram of a COUNT provided in an embodiment of the present application;

[0093] Figure 4b A schematic diagram of a process for determining HFN provided in an embodiment of the present application;

[0094] Figure 4c A schematic diagram of the positional relationship between HFN information and its corresponding SN provided in an embodiment of the present application;

[0095] Figure 4d A schematic diagram of the positional relationship between another HFN information and its corresponding SN provided in an embodiment of the present application;

[0096] Figure 5 A flow chart of a communication method provided in an embodiment of the present application;

[0097] Figure 6 A flowchart of another communication method provided in an embodiment of the present application;

[0098] Figure 7a A schematic diagram of a PDCP PDU format provided in an embodiment of the present application;

[0099] Figure 7bA schematic diagram of another PDCP PDU format provided in an embodiment of the present application;

[0100] Figure 7c A schematic diagram of another PDCP PDU format provided in an embodiment of the present application;

[0101] Figure 7d A schematic diagram of another PDCP PDU format provided in an embodiment of the present application;

[0102] Figure 7e A schematic diagram of another PDCP PDU format provided in an embodiment of the present application;

[0103] Figure 7f A schematic diagram of another PDCP PDU format provided in an embodiment of the present application;

[0104] Figure 8 A flowchart of another communication method provided in an embodiment of the present application;

[0105] Fig. 9 A schematic block diagram of a terminal device provided in an embodiment of the present application;

[0106] Fig.10 A schematic block diagram of a network device provided in an embodiment of the present application;

[0107] Fig.11 A schematic block diagram of a communication device provided in an embodiment of the present application;

[0108] Fig.12 Another schematic block diagram of a communication device provided in an embodiment of the present application;

[0109] Fig.13 Another schematic block diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0110] The technical solutions in the embodiments of the present invention will be described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0111] First, some terms in the embodiments of the present application are explained to facilitate understanding by those skilled in the art.

[0112] (1) Terminal device: A terminal device is a device with wireless transceiver functions, which can be a fixed device, a mobile device, a handheld device (such as a mobile phone), a wearable device, a vehicle-mounted device, or a wireless device built into the above devices (such as a communication module, a modem, or a chip system, etc.). The terminal device is used to connect people, objects, machines, etc., and can be widely used in various scenarios, such as but not limited to the following scenarios: cellular communication, device-to-device communication (D2D), vehicle to everything (V2X), machine-to-machine / machine-type communications (M2M / MTC), Internet of Things (IoT), virtual reality (VR), augmented reality (AR), industrial control, self driving, remote medical, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city, drones, robots and other scenarios. The terminal device may sometimes be referred to as user equipment (UE), terminal, access station, UE station, remote station, wireless communication equipment, or user device, etc. For the convenience of description, the terminal device will be explained using UE as an example in this application.

[0113] (2) Network equipment: for example, including access network equipment and / or core network equipment. The access network equipment is a device with wireless transceiver function, which is used to communicate with the terminal device. The access network equipment includes but is not limited to base stations (BTS, Node B, eNodeB / eNB, or gNodeB / gNB), transmission reception points (TRP) in the above-mentioned communication system, base stations of subsequent evolution of 3GPP, access nodes in WiFi systems, wireless relay nodes, wireless backhaul nodes, etc. The base station can be: macro base station, micro base station, micro-micro base station, small station, relay station, etc. Multiple base stations can support the networks of the same access technology mentioned above, or they can support the networks of different access technologies mentioned above. The base station can include one or more co-site or non-co-site transmission and reception points. The network device can also be a wireless controller, a centralized unit (CU), and / or a distributed unit (DU) in the cloud radio access network (CRAN) scenario. The network device can also be a server, a wearable device, or an in-vehicle device, etc. For example, the network equipment in the V2X technology may be a road side unit (RSU). The following describes the access network equipment by taking the base station as an example. The multiple network devices in the communication system may be base stations of the same type or different types. The base station may communicate with the terminal device or communicate with the terminal device through a relay station. The terminal device may communicate with multiple base stations in different access technologies. The core network equipment is used to implement functions such as mobility management, data processing, session management, policy and billing. The names of the devices that implement the core network functions in systems with different access technologies may be different, and this application does not limit this. Taking the 5G system as an example, the core network equipment includes: access and mobility management function (AMF), session management function (SMF), or user plane function (UPF), etc.

[0114] (3) In the embodiment of the present application, the terminal device or network device includes a hardware layer, an operating system layer running on the hardware layer, and an application layer running on the operating system layer. The hardware layer includes hardware such as a central processing unit (CPU), a memory management unit (MMU), and a 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 a Linux operating system, a Unix operating system, an Android operating system, an iOS operating system, or a Windows operating system. The application layer includes applications such as browsers, address books, word processing software, and instant messaging software. In addition, the embodiment of the present application does not specifically limit the specific structure of the execution subject of the method provided in the embodiment of the present application. As long as it can communicate according to the method provided in the embodiment of the present application by running a program that records the code of the method provided in the embodiment of the present application, for example, the execution subject of the method provided in the embodiment of the present application can be a terminal device or a network device, or a functional module in the terminal device or the network device that can call and execute a program.

[0115] In addition, various aspects or features of the present application can be implemented as methods, devices or products using standard programming and / or engineering techniques. The term "product" used in this application covers computer programs that can be accessed from any computer-readable device, carrier or medium. For example, computer-readable media may include, but are not limited to: magnetic storage devices (e.g., hard disks, floppy disks or tapes, etc.), optical disks (e.g., compact discs (CDs), digital versatile discs (DVDs), etc.), smart cards and flash memory devices (e.g., erasable programmable read-only memory (EPROM), cards, sticks or key drives, etc.). In addition, the various storage media described herein may represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing and / or carrying instructions and / or data.

[0116] (4) The terms "system" and "network" in the embodiments of the present application can be used interchangeably. "At least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and subsequent associated objects are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of A, B and C" includes A, B, C, AB, AC, BC or ABC.

[0117] Furthermore, unless otherwise specified, ordinal numbers such as "first" and "second" mentioned in the embodiments of the present application are used to distinguish multiple objects, and are not used to limit the order, timing, priority or importance of multiple objects. For example, the first SN and the second SN are only used to distinguish different SNs, and do not indicate the difference in priority or importance of the two SNs.

[0118] The technical solution of the present application is further described in detail below in conjunction with the accompanying drawings.

[0119] Figure 1 Schematic diagram of a communication system applicable to the embodiment of the present application. Figure 1 As shown, the terminal device 130 can access the wireless network to obtain services of the external network (such as the Internet) through the wireless network, or communicate with other devices through the wireless network, such as communicating with other terminal devices. The wireless network includes a radio access network (RAN) device 110 and a core network (CN) device 120, wherein the RAN device 110 is used to access the terminal device 130 to the wireless network, and the CN device 120 is used to manage the terminal device and provide a gateway for communicating with the external network. It should be understood that Figure 1 The number of devices in the communication system shown is for illustration only, and the embodiments of the present application are not limited thereto. In actual applications, the communication system may further include more terminal devices 130, more RAN devices 110, and other devices.

[0120] Figure 2 FIG. 1 is another schematic diagram of a network architecture applicable to the embodiment of the present application. Figure 2As shown, the network architecture includes CN equipment, RAN equipment and terminal equipment. Among them, the RAN equipment includes a baseband device and a radio frequency device, wherein the baseband device can be implemented by one node or by multiple nodes, and the radio frequency device can be implemented independently from the baseband device, or integrated in the baseband device, or some functions are integrated independently and some functions are integrated in the baseband device. For example, in an LTE communication system, the RAN equipment (eNB) includes a baseband device and a radio frequency device, wherein the radio frequency device can be arranged remotely relative to the baseband device, for example, a remote radio unit (RRU) is a remote wireless unit arranged relative to the BBU.

[0121] The communication between RAN equipment and terminal equipment follows a certain protocol layer structure. For example, the control plane protocol layer structure may include the functions of protocol layers such as the radio resource control (RRC) layer, the packet data convergence protocol (PDCP) layer, the radio link control (RLC) layer, the media access control (MAC) layer and the physical layer; the user plane protocol layer structure may include the functions of protocol layers such as the PDCP layer, the RLC layer, the MAC layer and the physical layer; in a possible implementation, a service data adaptation protocol (SDAP) layer may also be included above the PDCP layer.

[0122] The RAN device may implement the functions of the protocol layers such as RRC, PDCP, RLC and MAC by one node, or may implement the functions of these protocol layers by multiple nodes. For example, in an evolutionary structure, the RAN device may include a CU) and a DU, and multiple DUs may be centrally controlled by one CU. Figure 2 As shown, CU and DU can be divided according to the protocol layers of the wireless network, for example, the functions of the PDCP layer and above protocol layers are set in the CU, and the functions of the protocol layers below the PDCP, such as the RLC layer and the MAC layer, are set in the DU.

[0123] This division of the protocol layer is only an example. It can also be divided in other protocol layers, such as dividing in the RLC layer, setting the functions of the RLC layer and the protocol layers above in the CU, and the functions of the protocol layers below the RLC layer in the DU; or dividing in a certain protocol layer, for example, setting some functions of the RLC layer and the functions of the protocol layers above the RLC layer in the CU, and setting the remaining functions of the RLC layer and the functions of the protocol layers below the RLC layer in the DU. In addition, it can also be divided in other ways, such as dividing by latency, setting the functions whose processing time needs to meet the latency requirements in the DU, and the functions that do not need to meet the latency requirements in the CU.

[0124] In addition, the radio frequency device can be independently integrated and not placed in the DU, or it can be integrated in the DU, or partly remotely located and partly integrated in the DU, without any limitation here.

[0125] Figure 3 FIG. 1 is another schematic diagram of a network architecture applicable to an embodiment of the present application. Figure 2 The network architecture shown, Figure 3 The control plane (CP) and the user plane (UP) of the CU can also be separated and implemented by dividing them into different entities, namely, a control plane (CP) CU entity (i.e., a CU-CP entity) and a user plane (UP) CU entity (i.e., a CU-UP entity).

[0126] In the above network architecture, the signaling generated by the CU can be sent to the terminal device through the DU, or the signaling generated by the terminal device can be sent to the CU through the DU. The DU can directly encapsulate the signaling through the protocol layer and transparently transmit it to the terminal device or CU without parsing it. In the following embodiments, if the transmission of such signaling between the DU and the terminal device is involved, at this time, the sending or receiving of the signaling by the DU includes this scenario. For example, the signaling of the RRC or PDCP layer will eventually be processed as the signaling of the PHY layer and sent to the terminal device, or it will be converted from the received signaling of the PHY layer. Under this architecture, the signaling of the RRC or PDCP layer can also be considered to be sent by the DU, or sent by the DU and the RF loader.

[0127] Above Figure 1 , Figure 2 or Figure 3The network architecture shown can be applicable to communication systems of various radio access technologies (RAT), for example, it can be an LTE communication system, it can also be a 5G (or new radio (NR)) communication system, it can also be a transition system between an LTE communication system and a 5G communication system, the transition system can also be called a 4.5G communication system, and of course it can also be a future communication system. The network architecture and service scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. It is known to those skilled in the art that with the evolution of the communication network architecture and the emergence of new service scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems. For example, the present invention can be applicable to broadcast-multicast scenarios, or vehicle to everything (V2X) scenarios.

[0128] The devices in the following embodiments of the present application may be located in a terminal device or a network device according to the functions implemented. When the above CU-DU structure is adopted, the network device may be a CU node, a DU node, or a RAN device including a CU node and a DU node.

[0129] It should be noted that, in the embodiments of the present application, "if" can be understood as "when..." or "when the conditions..." or "under the circumstances..."; in addition, "located in" can also be understood as "occupied" or "in"; the present application does not make a distinction between the two, and they can be used interchangeably in the following description.

[0130] It should be noted that, in the embodiments of the present application, "HFN of PDCP protocol data unit (PDU)" can be understood as "HFN corresponding to PDCP PDU"; the present application does not make a distinction between the two, and they can be used interchangeably in the following description.

[0131] It should be noted that in the embodiments of the present application, "groupcast" can also be understood as "multicast", "broadcast", and "multicast broadcast"; the present application does not make any distinction between the two and they are used interchangeably in the following description.

[0132] It should be noted that in the embodiments of the present application, "setting" can be understood as "determining". The present application does not make any distinction between the two and they can be used interchangeably in the following description.

[0133] It should be noted that in the embodiments of the present application, "SN" can be understood as "PDCP SN". The present application does not make any distinction between the two and they can be used interchangeably in the following description.

[0134] It should be noted that, in the embodiments of the present application, "COUNT of PDCP PDU" can be understood as: "COUNT corresponding to PDCP PDU". The present application does not make any distinction between the two and they can be used interchangeably in the following description.

[0135] It should be noted that in the embodiments of the present application, "existence" can be understood as "includes" or "including", and the present application does not make any distinction between the two, and they can be used interchangeably in the following description.

[0136] It should be noted that in the embodiments of the present application, "domain (e.g., field)" can be understood as "field", and the present application does not make any distinction between the two, and they can be used interchangeably in the following description.

[0137] It should be noted that in the embodiments of the present application, the "PDU header" can be understood as the "PDCP PDU (or the first PDCP PDU) header" or the "PDU header of the PDCP PDU (or the first PDCP PDU)" or the "header of the PDCP PDU (or the first PDCP PDU)". The present application does not make any distinction between the two and they can be used interchangeably in the following description.

[0138] Optionally, in an embodiment of the present application, PDCP PDU can be understood as a "first PDCP PDU", and the present application does not make any distinction between the two, and they can be used interchangeably in the following description.

[0139] For example, the receiving side window may include (or be understood as) a reordering window.

[0140] The following is an introduction to the relevant technical features involved in the embodiments of the present application.

[0141] In the prior art, COUNT can be used for integrity protection and encryption of PDCP data packets. After the sender encrypts the data packet using COUNT, it sends the encrypted data packet to the receiver. The receiver needs to obtain COUNT to decrypt the data packet. Each PDCP PDU is associated with a COUNT, where COUNT is 32 bits. Figure 4aAs shown, COUNT can be composed of two parts: a high-order Hyper Frame Number (HFN) and a low-order PDCP Sequence Number (SN). The length of the PDCP SN is configured by an upper layer (e.g., a radio access control RRC layer) or a network device, and the length of the HFN varies with the length of the PDCP SN. For example, the length of the PDCP SN can be 12 bits or 18 bits, and accordingly, the length of the HFN can be (32-PDCP SN size) bits, wherein the PDCP SN size is the number of bits corresponding to the length of the PDCP SN. For example, if the PDCP SN size is 12 bits, the length of the HFN is (32-12) bits, i.e., 20 bits.

[0142] The two communicating parties (e.g., the terminal device 130 and the wireless access network device 110) will each maintain their own HFN. Before data transmission, the same HFN initial value (e.g., HFN starts from 0) can be used. During the data transmission process, the sending end uses COUNT to encrypt and / or integrity protect the data packet, and then sends the encrypted data packet and the SN of the data packet to the receiving end. After parsing the SN of the data packet, the receiving end can determine the COUNT of the received PDCP data PDU based on the SN and the HFN calculated by the receiving end, and then use the COUNT to decrypt and / or integrity check the data packet. The schematic diagram of the process of the existing receiving end calculating HFN can be found in Figure 4b As shown, including:

[0143] Step 1: Receive a PDCP PDU and determine the PDCP SN of the PDCP PDU;

[0144] Step 2: If the PDCP SN of the PDCP PDU is less than the difference between the SN part of the state variable and the reordering window size, then execute step 3; otherwise, execute step 4.

[0145] Step 3: PDCP HFN of PDCP PDU = HFN part of state variable + 1.

[0146] Step 4: If the PDCP SN of the PDCP PDU is greater than or equal to the sum of the SN part of the state variable and the reordering window size, then execute step 5; otherwise, execute step 6.

[0147] Step 5, PDCP HFN of PDCP PDU = HFN part of state variable - 1.

[0148] Step 6, PDCP HFN of PDCP PDU = HFN part of state variable

[0149] The COUNT of the PDCP PDU is determined based on the calculated PDCP HFN of the PDCP PDU and the PDCP SN of the PDCP PDU. As above, the reordering window size is equal to 2 (X-1) , the state variable indicates the COUNT of the first PDCP SDU that has not been delivered to the upper layer but is still waiting. The initial value is 0. In addition, ">=" means greater than or equal to.

[0150] According to the above technical feature description, the existing mechanism can keep the same HFN initial value (for example, HFN starts from 0) at the receiving end and the sending end before data is sent and received. Based on this, the sending and receiving parties can perform HFN maintenance based on the same HFN initial value and the same mechanism. However, for some scenarios, before the terminal device and the network device send and receive data, the data packet transmission may have been for a period of time. At this time, the terminal device cannot correctly determine the HFN value. In other words, the HFN between the terminal device and the network device is out of sync at this time, and the data packets subsequently sent and received by the terminal device and the network device may be due to the HFN out of sync problem. It may cause the COUNT understood by the terminal device and the network device to be inconsistent, which may cause the decrypted data to be problematic or invalid data packets, affecting the reliability of data communication. It may also cause the terminal device to be unable to correctly perform integrity verification, thereby discarding the data packet, affecting the reliability of data communication. It may also cause the network device to be unable to correctly understand the receiving status of the terminal device side when the terminal device feeds back the status report to the network device, which may cause erroneous packet loss or unnecessary retransmission, affecting the reliability and / or communication efficiency of data communication. It may also cause out-of-order delivery by terminal devices, affecting the reliability and / or communication efficiency of data communications.

[0151] Some of the above scenarios include but are not limited to the following two scenarios: 1) The terminal device newly joins a network device that is sending a multicast broadcast service (MBS). If the network device has sent the MBS for a period of time before, the HFN between the terminal device and the network device is not synchronized at this time; 2) The network device newly joins the MBS service, but the MBS service has been sent in other network devices for a period of time, making the HFN between the network device and the terminal device served by it not synchronized.

[0152] Based on this, the embodiment of the present application provides a communication method and apparatus to solve the problem of HFN asynchronism between a terminal device and a network device. Exemplarily, the method provided in the embodiment of the present application may include two possible solutions, which are referred to as Solution 1 and Solution 2 for ease of description.

[0153] In scheme 1, the terminal device receives the first information from the network device, and determines the HFN corresponding to the received PDCP PDU according to the first information and the second SN information carried in the received PDCP PDU; in this way, the first information is provided by the network device to assist the terminal device in determining the HFN of the received PDCP PDU, so that the terminal device and the network device can align the HFN or the initial value of the HFN of the PDCP PDU. The normal reception of data is guaranteed, and the packet loss or disordered delivery caused by HFN misalignment is avoided, which helps to improve reliability. In addition, it may also be beneficial to the decryption and integrity verification on the terminal device side, avoiding the packet loss problem caused by unsuccessful integrity verification, and improving reliability. In addition, compared with the scheme in which the terminal device sets RX_DELIV to the COUNT provided by the network device, the above method can avoid the problem of data packet loss and / or receiving side window jamming caused by unreasonable COUNT setting (for example, because some data failed to be successfully received, the window cannot slide, resulting in the inability to deliver data to the upper layer, increasing communication delay), improves the reliability of data reception, improves communication efficiency, and reduces communication delay.

[0154] In the second scheme, the terminal device receives the first indication information from the network device, and determines whether the PDCP PDU carries HFN information or COUNT information according to the first indication information. If the PDCP PDU carries HFN information or COUNT information, the terminal device can determine the HFN of the received PDCP PDU according to the HFN information or COUNT information. In this way, on the one hand, by carrying HFN information or COUNT information in the PDCP PDU / PDU header, the terminal device can accurately determine the HFN of the received PDCP PDU, and the HFN maintenance between the terminal device and the network device is simpler and / or more flexible, ensuring the normal reception of data, avoiding packet loss or disordered delivery caused by HFN misalignment, and helping to improve reliability. In addition, it may also be beneficial to decryption and integrity verification on the terminal device side, avoiding packet loss due to unsuccessful integrity verification, and improving reliability. In addition, compared with the solution in which the terminal device sets RX_DELIV to the COUNT provided by the network device, the above method can avoid the problem of data packet loss and / or receiving side window jamming due to unreasonable COUNT setting (for example, because some data failed to be successfully received, the window cannot slide, resulting in the inability to deliver data to the upper layer, increasing communication delay), thereby improving the reliability of data reception, improving communication efficiency, and reducing communication delay. On the other hand, by introducing the first indication information, the PDCP PDU (or, PDU header) does not need to carry HFN information or COUNT information all the time, which can reduce the overhead of air interface resources. At the same time, the terminal device can correctly determine the format of the PDCP PDU (or, PDU header), so that the PDCP PDU (or, PDU header) can be correctly decoded, thereby improving the reliability of data reception.

[0155] The method provided by the present application is described below. It should be understood that the method embodiments described below only take the execution subject as a network device and a terminal device as an example, but it is not limited to a network device and a terminal device. The network device and the terminal device can be replaced by a device that can implement the method in the application. For example, the network device can also be replaced by a chip configured in the network device, and the terminal device can also be replaced by a chip configured in the terminal device.

[0156] Figure 5 A flow chart corresponding to a communication method provided in an embodiment of the present application is shown in FIG. Figure 5 As shown, including:

[0157] S501. A terminal device receives first information from a network device, and correspondingly, the network device sends the first information to the terminal device.

[0158] The first information includes any one of the following: information of the first HFN and information of the first SN; or information of the first HFN and information of the SN range; or information of the COUNT range.

[0159] The first information includes the information of the first HFN and the information of the first SN. It can be understood (or replaced) that the first information includes the information of the first COUNT. It can be understood that the terminal device determines the information of the first HFN and the information of the first SN according to the information of the first COUNT. Figure 4a It can be known that COUNT may include a high-order HFN and a low-order SN. It can be understood that the terminal device determines the information of the first HFN and the information of the first SN according to the information of the first COUNT, which can be specifically: the terminal device sets the high-order bits of the first COUNT to the bits of the first HFN, and sets the low-order bits of the first COUNT to the bits of the first SN.

[0160] It can be understood that (1) the information of the first HFN may include the first HFN value or the index of the first HFN. The information of the first SN may include the first SN value or the index of the first SN.

[0161] Optionally, the information of the first HFN may include information of all bits or part of bits of the first HFN.

[0162] Optionally, the information of the first SN may include information of all bits or part of the bits of the first SN.

[0163] (2) The information of the SN range may include (or be called, or be replaced by) information of the third SN and information of the fourth SN. It can be understood that the information of the SN range can be determined by the information of the third SN and the fourth SN. In one possible implementation, the third SN is the lower boundary of the SN range (or the minimum value in the SN range), and the fourth SN is the upper boundary of the SN range (or the maximum value in the SN range). For example, the SN range may be: an SN that is greater than (or greater than or equal to) the third SN and less than (or less than or equal to) the fourth SN. For example, the third SN is less than or equal to the fourth SN. For example, the minimum value in the SN range (or the third SN) may be 0. For example, the maximum value in the SN range (or the fourth SN) may be 2 X -1. Wherein, X represents the number of bits corresponding to the SN (or SN length). For example, the third SN is 50, the fourth SN is 100, and the SN range is: greater than (or, greater than or equal to) 50, less than (or, less than or equal to) 100. Specifically, the SN range can be one of the following: greater than 50 and less than 100; greater than or equal to 50 and less than 100; greater than 50 and less than or equal to 100; greater than or equal to 50 and less than or equal to 100.

[0164] Optionally, the information of the third SN may include information of all bits or information of part of the bits of the third SN.

[0165] Optionally, the information of the fourth SN may include information of all bits or information of part of the bits of the fourth SN.

[0166] As can be seen from the above, the third SN and the fourth SN are configurable. In other words, the third SN and the fourth SN are variable. For example, the minimum value of the third SN is 0. For example, the maximum value of the fourth SN is 2. X -1.

[0167] The first information includes the information of the first HFN and the information of the SN range. It can be understood (or replaced by): the first information includes the information of the first COUNT and the information of the fourth SN; or, the information of the third SN and the information of the second COUNT. It can be understood that the terminal device determines the information of the first HFN and the third SN according to the information of the first COUNT. It can be understood that the terminal device determines the information of the first HFN and the fourth SN according to the information of the second COUNT. Figure 4a It can be known that COUNT may include a high-order HFN and a low-order SN. It can be understood that the terminal device determines the information of the first HFN and the information of the third SN based on the information of the first COUNT, which can be specifically: the terminal device sets the high-order bits of the first COUNT to the bits of the first HFN, and sets the low-order bits of the first COUNT to the bits of the third SN. The terminal device determines the information of the first HFN and the information of the fourth SN based on the information of the second COUNT, which can be specifically: the terminal device sets the high-order bits of the second COUNT to the bits of the first HFN, and sets the low-order bits of the first COUNT to the bits of the fourth SN.

[0168] In one possible implementation, the network device may send one of the information of the third SN and the information of the fourth SN. In other words, the first information sent by the network device may include one of the information of the third SN and the information of the fourth SN. It is understandable that the terminal device receives one of the information of the third SN and the information of the fourth SN from the network device. In this case, the terminal device determines the other of the information of the third SN and the information of the fourth SN based on one of the information of the third SN and the information of the fourth SN. For example, if the network device sends the information of the third SN but does not send the information of the fourth SN, or in other words, the first information may include the information of the third SN but does not include the information of the fourth SN, the terminal device determines the information of the fourth SN based on the information of the third SN. For example, the fourth SN is equal to the third SN+b, where b is an integer. For example, b can be 2. (X-1). Wherein, X represents the number of bits corresponding to SN (or SN length). For another example, if the network device sends the information of the fourth SN but does not send the information of the third SN, or in other words, the first information includes the information of the fourth SN but does not include the information of the third SN; the terminal device determines the information of the third SN based on the information of the fourth SN. For example, the third SN is equal to the fourth SN-b, where b is an integer. For example, b can be 2 (X-1) . Where X represents the number of bits corresponding to SN (or SN length).

[0169] It should be noted that b can be determined by the protocol, or can be indicated by the network device to the terminal device, or can be pre-configured, and this application does not limit it.

[0170] (3) The information of the COUNT range includes (or is called or replaced by): information of the first COUNT and information of the second COUNT. It can be understood that the COUNT range can be determined by the information of the first COUNT and the second COUNT. In one possible implementation, the first COUNT is the lower boundary of the COUNT range (or the minimum value in the COUNT range), and the second COUNT is the upper boundary of the COUNT range (or the maximum value in the COUNT range). For example, the COUNT range may include / be: greater than (or, greater than or equal to) the first COUNT, less than (or, less than or equal to) the second COUNT. For example, the first COUNT is less than or equal to the second COUNT. For example, the minimum value in the COUNT range (or the first COUNT) is 0. For example, the maximum value in the COUNT range (or the second COUNT) is 2 Y -1. Wherein, Y represents the number of bits corresponding to COUNT (or COUNT length). For example, the first COUNT is 1000, the second COUNT is 1500, and the COUNT range includes / is: greater than (or, greater than or equal to) 1000, and less than (or, less than or equal to) 1500. Specifically, the COUNT range can be one of the following: greater than 1000 and less than 1500; greater than or equal to 1000 and less than 1500; greater than 1000 and less than or equal to 1500; greater than or equal to 1000 and less than or equal to 1500.

[0171] Optionally, the information of the first COUNT may include information of all bits or information of part of the bits of the first COUNT.

[0172] Optionally, the information of the second COUNT may include information of all bits or information of part of the bits of the second COUNT.

[0173] As can be seen from the above, the first COUNT and the second COUNT are configurable. In other words, the first COUNT and the second COUNT are variable. For example, the minimum value of the first COUNT is 0. For example, the maximum value of the second COUNT is 2. Y -1.

[0174] There are many implementations of the first COUNT information and the second COUNT information, which are described below in conjunction with implementations A1 to A4.

[0175] Implementation A1 The information of the first COUNT and the information of the second COUNT may include information of the second HFN, information of the third HFN and information of the fifth SN.

[0176] In this way, the information of the fifth SN is shared. For example, the terminal device can obtain the information of the first COUNT and the second COUNT based on the information of the fifth SN, the information of the second HFN and the information of the third HFN. Through this method, the network device does not need to repeatedly indicate the information of the fifth SN, thereby saving signaling overhead.

[0177] Depend on Figure 4a It can be known that COUNT may include a high-order HFN and a low-order SN. It can be understood that the above-mentioned terminal device obtains the information of the first COUNT according to the information of the fifth SN and the information of the second HFN, and specifically, the terminal device sets the bit of the second HFN to the high bit of the first COUNT, and sets the bit of the fifth SN to the low bit of the first COUNT. The above-mentioned terminal device obtains the information of the second COUNT according to the information of the fifth SN and the information of the third HFN, and specifically, the terminal device sets the bit of the third HFN to the high bit of the second COUNT, and sets the bit of the fifth SN to the low bit of the second COUNT.

[0178] Optionally, the information of the second HFN may include information of all bits or part of bits of the second HFN. Optionally, the information of the third HFN may include information of all bits or part of bits of the third HFN. Optionally, the information of the fifth SN may include information of all bits or part of bits of the fifth SN.

[0179] In a possible implementation, the network device may send one of the information of the second HFN and the information of the third HFN. In other words, the first information sent by the network device may include one of the information of the second HFN and the information of the third HFN. It can be understood that the terminal device receives one of the information of the second HFN and the information of the third HFN from the network device. In this case, the terminal device determines the other of the information of the second HFN and the information of the third HFN according to one of the information of the second HFN and the information of the third HFN. For example, if the network device sends the information of the second HFN but does not send the information of the third HFN, or in other words, the first information includes the information of the second HFN but does not include the information of the third HFN, the terminal device determines the information of the third HFN according to the information of the second HFN. For example, the third HFN is equal to the second HFN+m, where m is an integer. For example, m can be 1. For another example, if the network device sends the information of the third HFN but does not send the information of the second HFN, or the first information includes the information of the third HFN but does not include the information of the second HFN; the terminal device determines the information of the second HFN according to the information of the third HFN. For example, the second HFN is equal to the third HFN-m, where m is an integer. For example, m can be 1.

[0180] It should be noted that m can be determined by the protocol, or can be indicated by the network device to the terminal device, or can be pre-configured, and this application does not limit it.

[0181] Implementation A2 The information of the first COUNT and the information of the second COUNT may include information of the fourth HFN, information of the fifth HFN, information of the sixth SN, and information of the seventh SN.

[0182] In this manner, the information of the fourth HFN includes the information of its corresponding SN (e.g., the information of the sixth SN or the information of the seventh SN), and the information of the fifth HFN also includes the information of its corresponding SN (e.g., the information of the seventh SN or the information of the sixth SN). The information of which SN the above HFN information corresponds to may be indicated by the network device or predefined by the protocol. It can be understood that as long as the same understanding method is maintained between the terminal device and the network device, the present invention does not limit this.

[0183] For example, Figure 4c As shown, the terminal device can learn that there is a corresponding relationship between the information of the fourth HFN and the information of the sixth SN, and then determine the information of the first COUNT (or the information of the second COUNT) according to the information of the fourth HFN and the information of the sixth SN; accordingly, the terminal device can learn that there is a corresponding relationship between the information of the fifth HFN and the information of the seventh SN, and then determine the information of the second COUNT (or the information of the first COUNT) according to the information of the fifth HFN and the information of the seventh SN.

[0184] For example, Figure 4d As shown, the terminal device can learn that there is a correspondence between the information of the fourth HFN and the information of the sixth SN, and between the information of the fifth HFN and the information of the seventh SN, and then determine the information of the first COUNT and the information of the second COUNT according to the above two correspondences.

[0185] It should be noted that, for determining the information of the first COUNT according to the information of the fourth HFN and the sixth SN, and determining the information of the second COUNT according to the information of the fifth HFN and the seventh SN, reference can be made to the explanation of obtaining the information of the first COUNT according to the information of the fifth SN and the second HFN in implementation method A1, which will not be repeated here.

[0186] Optionally, the information of the fourth HFN may include information of all bits or part of bits of the fourth HFN. Optionally, the information of the fifth HFN may include information of all bits or part of bits of the fifth HFN.

[0187] Optionally, the information of the sixth SN may include information of all bits or information of part of the bits of the sixth SN.

[0188] Optionally, the information of the seventh SN may include information of all bits or part of the bits of the seventh SN.

[0189] In a possible implementation, the network device may send one of the information of the fourth HFN and the information of the fifth HFN. In other words, the first information sent by the network device may include one of the information of the fourth HFN and the information of the fifth HFN. It can be understood that the terminal device receives one of the information of the fourth HFN and the information of the fifth HFN from the network device. In this case, the terminal device determines the other of the information of the fourth HFN and the information of the fifth HFN according to one of the information of the fourth HFN and the information of the fifth HFN. For example, if the network device sends the information of the fourth HFN but does not send the information of the fifth HFN, or in other words, the first information may include the information of the fourth HFN but does not include the information of the fifth HFN, the terminal device determines the information of the fifth HFN according to the information of the fourth HFN. For example, the fifth HFN is equal to the fourth HFN+n, where n is an integer. For example, n may be 1. For another example, if the network device sends the information of the fifth HFN but does not send the information of the fourth HFN, or in other words, the first information includes the information of the fifth HFN but does not include the information of the fourth HFN; the terminal device determines the information of the fourth HFN according to the information of the fifth HFN. For example, the fourth HFN is equal to the fifth HFN-n, where n is an integer. For example, n may be 1.

[0190] It should be noted that n can be determined by the protocol, or can be indicated by the network device to the terminal device, or can be pre-configured, and this application does not limit it.

[0191] In one possible implementation, the network device may send one of the information of the sixth SN and the information of the seventh SN. In other words, the first information sent by the network device may include one of the information of the sixth SN and the information of the seventh SN. It is understandable that the terminal device receives one of the information of the sixth SN and the information of the seventh SN from the network device. In this case, the terminal device determines the other of the information of the sixth SN and the information of the seventh SN based on one of the information of the sixth SN and the information of the seventh SN. For example, if the network device sends the information of the sixth SN but does not send the information of the seventh SN, or in other words, the first information may include the information of the sixth SN but does not include the information of the seventh SN, the terminal device determines the information of the seventh SN based on the information of the sixth SN. For example, the seventh SN is equal to the sixth SN+p, where p is an integer. For example, p can be 2. (X-1) . Wherein, X represents the number of bits corresponding to SN (or SN length). For another example, if the network device sends the information of the seventh SN but does not send the information of the sixth SN, or in other words, the first information includes the information of the seventh SN but does not include the information of the sixth SN; the terminal device determines the information of the sixth SN based on the information of the seventh SN. For example, the sixth SN is equal to the seventh SN-p, where p is an integer. For example, p can be 2 (X-1) . Where X represents the number of bits corresponding to SN (or SN length).

[0192] It should be noted that p can be determined by the protocol, or can be indicated by the network device to the terminal device, or can be pre-configured, and this application does not limit it.

[0193] Implementation A3: The information of the first COUNT and the information of the second COUNT may include: information of the first COUNT / information of the second COUNT and information of the eighth SN.

[0194] In this manner, in a possible implementation, the HFN information corresponding to the first COUNT / the second COUNT may be shared.

[0195] In this manner, in another possible implementation, the terminal device may determine the HFN information corresponding to the second COUNT (or the HFN information corresponding to the first COUNT) according to the HFN information corresponding to the first COUNT (or the HFN information corresponding to the second COUNT).

[0196] For example, the terminal device may determine the information of the HFN corresponding to the second COUNT according to the information of the HFN corresponding to the first COUNT. For example, the HFN corresponding to the second COUNT is equal to the HFN corresponding to the first COUNT+v, where v is an integer. For example, v may be 1.

[0197] For example, the terminal device may determine the information of the HFN corresponding to the first COUNT according to the information of the HFN corresponding to the second COUNT. For example, the HFN corresponding to the first COUNT is equal to the HFN corresponding to the second COUNT-v, where v is an integer. For example, v may be 1.

[0198] It should be noted that v can be determined by the protocol, or can be indicated by the network device to the terminal device, or can be pre-configured, and this application does not limit it.

[0199] For example, the terminal device can obtain the second COUNT / first COUNT information according to the HFN information corresponding to the first COUNT / second COUNT and the information of the eighth SN. Through this method, the network device does not need to repeatedly indicate the HFN information corresponding to the second COUNT / first COUNT, thereby saving signaling overhead.

[0200] Depend on Figure 4a It can be known that COUNT may include a high-order HFN and a low-order SN. It can be understood that the above-mentioned terminal device obtains the information of the second COUNT / first COUNT according to the HFN information corresponding to the first COUNT / second COUNT and the information of the eighth SN. For example, the terminal device sets the bit of the HFN corresponding to the first COUNT / second COUNT to the high bit of the second COUNT / first COUNT, and sets the bit of the eighth SN to the low bit of the second COUNT / first COUNT. For example, the terminal device determines the HFN information corresponding to the second COUNT (or the HFN information corresponding to the first COUNT) according to the HFN information corresponding to the first COUNT (or the HFN information corresponding to the second COUNT), and the terminal device sets the bit of the HFN corresponding to the determined second COUNT (or the HFN corresponding to the first COUNT) to the high bit of the second COUNT / first COUNT, and sets the bit of the eighth SN to the low bit of the second COUNT / first COUNT.

[0201] Optionally, the information of the first COUNT may include information of all bits or information of part of the bits of the first COUNT.

[0202] Optionally, the information of the second COUNT may include information of all bits or information of part of the bits of the second COUNT.

[0203] Optionally, the information of the eighth SN may include information of all bits or part of the bits of the eighth SN.

[0204] Implementation A4 The information of the first COUNT and the information of the second COUNT may include information of the sixth HFN, information of the ninth SN, and information of the tenth SN.

[0205] In this manner, in a possible implementation, the information of the sixth HFN may be shared.

[0206] In this manner, in another possible implementation, the terminal device may determine the HFN information corresponding to the second COUNT (or the HFN information corresponding to the first COUNT) according to the information of the sixth HFN.

[0207] For example, the terminal device determines the second COUNT (or the information of the HFN corresponding to the first COUNT) according to the information of the sixth HFN. For example, the HFN corresponding to the second COUNT / first COUNT is equal to the sixth HFN+q or the sixth HFN-q, where q is an integer. For example, q can be 1.

[0208] It should be noted that q can be determined by the protocol, or can be indicated by the network device to the terminal device, or can be pre-configured, and this application does not limit it.

[0209] For example, the terminal device can obtain the information of the first COUNT and the second COUNT according to the information of the sixth HFN, in combination with the information of the ninth SN and the information of the tenth SN. Through this method, the network device does not need to repeatedly indicate the information of the sixth HFN or the HFN information corresponding to the second COUNT / first COUNT, which can save signaling overhead.

[0210] For example, the terminal device obtains the information of the first COUNT according to the information of the ninth SN and the sixth HFN. Specifically, the terminal device sets the bit of the sixth HFN to the high bit of the first COUNT and sets the bit of the ninth SN to the low bit of the first COUNT.

[0211] For example, the terminal device obtains the information of the second COUNT according to the information of the tenth SN and the sixth HFN. Specifically, the terminal device sets the bit of the sixth HFN as the high bit of the second COUNT and sets the bit of the tenth SN as the low bit of the second COUNT.

[0212] For example, the terminal device obtains the information of the first COUNT based on the information of the ninth SN and the information of the sixth HFN. Specifically, the terminal device determines the information of the HFN corresponding to the first COUNT based on the information of the sixth HFN, and the terminal device sets the bit of the HFN corresponding to the determined first COUNT as the high bit of the first COUNT, and sets the bit of the ninth SN to the low bit of the first COUNT.

[0213] For example, the terminal device obtains the information of the second COUNT according to the information of the tenth SN and the information of the sixth HFN, which may be specifically as follows: the terminal device determines the information of the HFN corresponding to the second COUNT according to the information of the sixth HFN, and the terminal device sets the bit of the HFN corresponding to the determined second COUNT as the high bit of the second COUNT, and sets the bit of the tenth SN as the low bit of the second COUNT. Optionally, the information of the sixth HFN may include information of all or part of the bits of the sixth HFN.

[0214] Optionally, the information of the ninth SN may include information of all bits or part of the bits of the ninth SN.

[0215] Optionally, the information of the tenth SN may include information of all bits or part of the bits of the tenth SN.

[0216] For the information involved in implementations A1 to A4, the specific indication method may be an explicit indication or an implicit indication. It can be understood that if explicit indication is adopted, the network device can indicate according to the explicit bit (or field), and accordingly, the terminal device can determine the corresponding information according to the explicit bit (or field); if implicit indication is adopted, the network device can indicate implicitly according to the existing bit (or field) or other information without introducing additional bits (or fields) for indication. For example, for the information of the first HFN, if it is indicated in an explicit manner, the network device can indicate the information of the first HFN through an explicit bit (or field), wherein the information of the first HFN includes the first HFN value or the index of the first HFN; if it is indicated in an implicit manner, since COUNT is composed of HFN and SN, the network device can implicitly indicate the first HFN information according to the COUNT information, and accordingly, the terminal device can determine the first HFN information according to the COUNT information.

[0217] It can be understood that if the information of the first HFN includes the index of the first HFN, the terminal device can determine the HFN value corresponding to the index of the first HFN according to the correspondence between the index, the HFN index and the HFN value.

[0218] In addition, for the information involved in the first information, the specific indication method can also be direct indication or indirect indication. It can be understood that if it is a direct indication, the terminal device can directly determine the corresponding information according to the indication information; if an indirect indication is used, the terminal device indirectly determines the corresponding information according to the indication information and the auxiliary parameters. For example, for the information of the first SN, if a direct indication is used, the terminal device can directly determine the first SN according to the information of the first SN; if an indirect indication method is used, the terminal device can indirectly determine the first SN according to the information of the first SN and the parameter r. Exemplarily, the terminal device determines the first SN as (SN+r corresponding to the information of the first SN) or (SN-r corresponding to the information of the first SN). For another example, for the information of the first HFN, if a direct indication is used, the terminal device can directly determine the first HFN according to the information of the first HFN; if an indirect indication method is used, the terminal device can indirectly determine the first HFN according to the information of the first HFN and the parameter s. Exemplarily, the terminal device determines the first HFN as (HFN+s corresponding to the information of the first HFN) or (HFN-s corresponding to the information of the first HFN). Among them, the parameter r and / or s can be obtained by the terminal device itself or from the network device. Here, if the terminal device obtains it by itself, it can be obtained by the terminal device through a preset subscriber identity module (SIM) card or by protocol preset; this method can save communication resources or signaling overhead between the terminal device and the network device. If the terminal device obtains it from the network device, it can be obtained through dedicated signaling, broadcast information, multicast information, and system information, which is not limited in this application. Specifically, the dedicated signaling can be a radio resource control (RRC) message, a media access control (MAC) control element (CE) or a downlink control information (DCI) message, which is not limited in the present invention.

[0219] In a possible implementation, the first information is carried in a radio resource control RRC message, or a broadcast message, or a radio bearer configuration corresponding to a first PDCP PDU (or, a first radio bearer configuration), or a PDCP control PDU, or a configuration corresponding to a first service. The first service includes a broadcast service and / or a multicast service.

[0220] In a possible implementation, the method further includes: before S501, the terminal device sends a request message to the network device, where the request message is used to request the first information; accordingly, the network device receives the request message sent by the terminal device.

[0221] Optionally, the request message may also be used to indicate that the terminal device is interested in the first service, or is receiving the first service, or is no longer interested in the first service, or is no longer receiving the first service. It should be noted that the request message may be implicitly used to request the first information, that is, the function of the request message and the name of the request message are not limited.

[0222] The first information is associated with the first PDCP entity and / or the first radio bearer.

[0223] The first PDCP entity and / or the first radio bearer are associated with a first service. The first service includes a broadcast and / or multicast service.

[0224] Optionally, the request message is carried in a radio resource control RRC message, a media access control control element MACCE, or a message in a random access process.

[0225] Optionally, the message in the random access process includes: the first message of the random access process (for example, Msg1 or MsgA), or the third message of the random access process (for example, Msg3).

[0226] Optionally, the network device may count a first quantity, the first quantity including: the number of request messages received by the network device; or the number of terminal devices requesting the first information; if a first preset condition is met, the network device sends the first information in a broadcast and / or multicast manner; if the first preset condition is not met, the network device sends the first information in a unicast manner, wherein the first preset condition may be: the first quantity is greater than or equal to a preset quantity.

[0227] In this way, the terminal device can send a request message to the network device to inform the network device of its own demand for the first information. Correspondingly, the network device can send the first information based on the request message sent by the terminal device. On the one hand, this makes the terminal device more flexible in obtaining the first information. On the other hand, the network device can use unicast to send the first information when there are fewer terminal devices requesting to obtain the first information, thereby avoiding unnecessary information reception by the terminal device. When there are many terminal devices requesting the first information, the first information is sent by broadcast and / or multicast, thereby avoiding the waste of resources caused by excessive use of unicast to send the first information.

[0228] S502, the terminal device receives a first PDCP PDU from the network device, where the first PDCP PDU includes a second SN; accordingly, the network device sends the first PDCP PDU to the terminal device.

[0229] Optionally, data corresponding to the first PDCP PDU may be scrambled by the first RNTI or the second RNTI, where the data may be a transport block (TB) or a MAC PDU.

[0230] It should be noted that the data corresponding to the first PDCP PDU may include multiple data, and the multiple data may be scrambled by different RNTIs. For example, some data are scrambled by the first RNTI, and some data are scrambled by the second RNTI.

[0231] The first RNTI and / or the second RNTI are associated with a broadcast and / or multicast service.

[0232] The first RNTI can be used for unicast, and can be used for any one or more of the following: for scheduling dynamic resources, for retransmission resources of dynamic resources, for activating configuration resources, for reactivating configuration resources, for deactivating configuration resources, for scheduling retransmission resources of configuration resources, and for scrambling (for example, for scrambling PDCCH or PDSCH).

[0233] For example, the first RNTI may be a cell radio network temporary identifier (C-RNTI) or a configured scheduling RNTI (CS-RNTI).

[0234] The second RNTI is used for broadcast and / or multicast, and can be used for any one or more of the following: for scheduling dynamic resources, for retransmission resources of dynamic resources, for activating configuration resources, for reactivating configuration resources, for deactivating configuration resources, for scheduling retransmission resources of configuration resources, and for scrambling (for example, for scrambling PDCCH or PDSCH).

[0235] For example, the second RNTI may be a group RNTI (G-RNTI).

[0236] Optionally, the first PDCP PDU is associated with a first channel (or a first logical channel).

[0237] The first channel (or first logical channel) may include a channel associated with any one or more of the first service, the first PDCP entity, and the first radio bearer. For example, the first channel may include a multicast broadcast service channel and / or a dedicated traffic channel (Dedicated Traffic Channel, DTCH).

[0238] For example, the channels associated with the first service may include: channels associated with unicast transmission of the first service and / or channels associated with multicast transmission of the first service.

[0239] It should be noted that the multicast broadcast service channel can be replaced by: a channel for broadcast and / or multicast, or a logical channel for broadcast and / or multicast services (eg, a channel for transmitting services).

[0240] In a possible implementation, the first channel is a multicast / multicast broadcast service logical channel (multicast traffic channel or MBS traffic channel, MTCH),

[0241] Optionally, the first PDCP PDU is associated with a first RLC entity.

[0242] The first RLC entity may include an RLC entity associated with the first service.

[0243] In a possible implementation, the first RLC entity is associated with a multicast broadcast service channel corresponding to the first service (or first radio bearer).

[0244] In a possible implementation, the first RLC entity is associated with a dedicated service channel corresponding to the first service (or first radio bearer).

[0245] For example, the network device may send the first PDCP PDU through the first logical channel, and correspondingly, the terminal device may receive the first PDCP PDU through the first logical channel. Here, the first logical channel is associated with a broadcast and / or multicast service.

[0246] It should be noted that S502 may be executed before S501, or S501 and S502 may be executed simultaneously. The sequence of S501 and S502 is not limited in the embodiment of the present application.

[0247] S503: The terminal device determines the HFN of the first PDCP PDU according to the first information and the second SN.

[0248] As described in S501, the first information may include a variety of possible information for determining the HFN of the first PDCP PDU, which is described below in conjunction with Examples a1 to a3.

[0249] Example a1 : The first information includes information of the first HFN and information of the first SN.

[0250] “The terminal device determines the HFN of the first PDCP PDU according to the first information and the second SN” may include: the terminal device determines the HFN of the first PDCP PDU according to the first information, the second SN and the first parameter.

[0251] It can be understood that the first SN can be directly or indirectly determined by the terminal device through information of the first SN. For the first SN, please refer to the description of the first SN in S501, which will not be repeated here.

[0252] It can be understood that the first HFN can be determined directly or indirectly by the terminal device through information of the first HFN.

[0253] For example a1, there are multiple ways for the terminal device to determine the HFN of the first PDCP PDU. For example, the terminal device may determine the HFN of the first PDCP PDU according to the second SN, the first SN, and the first parameter.

[0254] The first parameter may be obtained by the terminal device itself or from a network device. For specific methods, refer to the method for obtaining parameter a in S501, which will not be described in detail here.

[0255] Optionally, the first parameter can be the window size (or 2 (X-1) ), or the window size (or 2 (X-1) ) and the value obtained by mathematical operation of the pre-acquired parameter, where the pre-acquired parameter can be obtained by the terminal device itself or from the network device. For the specific method, refer to the method for obtaining the parameter r in S501, which will not be repeated here. Wherein, X represents the number of bits corresponding to the SN (or the SN length). The mathematical operation includes one or more of the following: addition, subtraction, multiplication, division, exponentiation, square root, logarithm, etc., which are not limited in the present invention.

[0256] Exemplarily, the pre-acquired parameter may be t1, t2, or t3, and accordingly, the first parameter may be (window size-t1), (window size+t1), (window size*t2), or (window size*2 t3 ) or (window size * 2 (-t3) ). For example, the window size can be 2 (X-1) Optionally, the number of bits of the SN may be 12 bits, 16 bits, or 18 bits, which is not limited in the present invention.

[0257] The following is an explanation of the combination of methods a1 to a3:

[0258] Mode a1: The terminal device determines the HFN of the first PDCP PDU, including any one or more of the following:

[0259] If the second SN is less than the difference between the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN plus 1;

[0260] If the second SN is greater than or equal to the sum of the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN minus 1;

[0261] If the second SN is greater than or equal to the difference between the first SN and the first parameter, and the second SN is less than the sum of the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN.

[0262] It should be noted that, in the present application, “the second SN is equal to the sum of the first SN and the first parameter, and the HFN of the first PDCP PDU is equal to the first HFN minus 1” is only a possible example.

[0263] It should be noted that, in the present application, “the second SN is equal to the difference between the first SN and the first parameter, and the HFN of the first PDCP PDU is equal to the first HFN” is only a possible example.

[0264] It should be noted that, for the case in the present application where the second SN is equal to the difference between the first SN and the first parameter or the second SN is equal to the sum of the first SN and the first parameter, the HFN of the first PDCP PDU may be equal to one of the following: the first HFN, the first HFN plus 1, or the first HFN minus 1, and the present invention is not limited to this.

[0265] For example, the length of SN is 12 bits, that is, the value range of SN is 0 to 4095, and accordingly, the SN space corresponding to one HFN is 0 to 4095. If the first parameter value is 2048, the first HFN carried by the network device through the first information is equal to 11, and the first SN is equal to 2500, then the sum of the first SN and the first parameter is 4548, and the difference between the first SN and the first parameter is 452. From method a1, it can be seen that if the second SN is equal to 800, 800 is greater than the difference between the first SN and the first parameter, and less than the sum of the first SN and the first parameter, that is, 800 is greater than 452 and 800 is less than 4548, then the HFN of the first PDCP PDU is equal to the first HFN, that is, the HFN of the first PDCP PDU is equal to 11; if the second SN is equal to 200, 200 is less than the difference between the first SN and the first parameter, that is, 200 is less than 452, then the HFN of the first PDCP PDU is equal to the first HFN plus 1, that is, the HFN of the first PDCP PDU is equal to 12.

[0266] Mode a2: The terminal device determines the HFN of the first PDCP PDU, including any one or more of the following:

[0267] If the second SN is less than the difference between the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN plus 1;

[0268] If the second SN is greater than or equal to the difference between the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN.

[0269] Mode a3: The terminal device determines the HFN of the first PDCP PDU, including any one or more of the following:

[0270] If the second SN is greater than or equal to the sum of the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN minus 1;

[0271] If the second SN is less than the sum of the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN.

[0272] It should be noted that any one or more of the methods a1 to a3 can be combined, and this application does not limit this.

[0273] Example a2 : The first information includes information of the first HFN and information of the SN range.

[0274] For example a2, there are multiple ways for the terminal device to determine the HFN of the first PDCP PDU, which are described below using ways b1 and b2 as examples.

[0275] Mode b1: The terminal device determines the HFN of the first PDCP PDU, including any one or more of the following:

[0276] If the second SN is within the SN range, the HFN of the first PDCP PDU is equal to the first HFN;

[0277] If the second SN is less than the minimum value in the SN range, the HFN of the first PDCP PDU is equal to the first HFN plus 1;

[0278] If the second SN is greater than a maximum value in the SN range, the HFN of the first PDCP PDU is equal to the first HFN minus 1.

[0279] The minimum value in the SN range may be understood or replaced by the third SN.

[0280] The maximum value in the SN range can be understood or replaced by the fourth SN.

[0281] The second SN within the SN range can be understood or replaced as: the second SN is greater than or equal to the third SN, and the second SN is less than or equal to the fourth SN.

[0282] It should be noted that, in the present application, “the second SN is equal to the minimum value in the SN range, and the HFN of the first PDCP PDU is equal to the first HFN” is only a possible example.

[0283] It should be noted that, in the present application, “the second SN is equal to the maximum value in the SN range, and the HFN of the first PDCP PDU is equal to the first HFN” is only a possible example.

[0284] It should be noted that, for the case where the second SN is equal to the minimum value in the SN range, or the second SN is equal to the maximum value in the SN range in the present application, the HFN of the first PDCP PDU may be equal to one of the following: the first HFN, the first HFN plus 1, and the first HFN minus 1, and the present invention is not limited to this.

[0285] For example, the length of SN is 12 bits, that is, the value range of SN is 0-4095. Accordingly, a round of SN space corresponding to one HFN is 0-4095, and the SN range is from 0 to 1700. From mode b1, it can be seen that if the second SN is equal to 2000, 2000 is greater than the maximum value in the SN range, that is, 2000 is greater than 1700, then the HFN of the first PDCP PDU is equal to the first HFN minus 1, that is, the HFN of the first PDCP PDU is equal to 10; if the second SN is equal to 800, 800 is greater than the minimum value in the SN range and less than the maximum value in the SN range, that is, 800 is greater than 300 and 800 is less than 1700, then the HFN of the first PDCP PDU is equal to the first HFN, that is, the HFN of the first PDCP PDU is equal to 11.

[0286] Mode b2: The terminal device determines the HFN of the first PDCP PDU, including any one or more of the following:

[0287] If the value corresponding to the received SN range starts from 0, and if the second SN is within the SN range, the HFN of the first PDCP PDU is equal to the first HFN;

[0288] If the value corresponding to the received SN range starts from 0, and if the second SN is greater than the maximum value in the SN range, the HFN of the first PDCP PDU is equal to the first HFN minus 1;

[0289] If the received SN range corresponds to the maximum SN value (for example, 2 X -1) ends, and if the second SN is within the SN range, the HFN of the first PDCP PDU is equal to the first HFN;

[0290] If the received SN range corresponds to the maximum SN value (for example, 2 X-1) ends, and if the second SN is less than the minimum value in the SN range, the HFN of the first PDCP PDU is equal to the first HFN plus 1.

[0291] "The values ​​corresponding to the SN range start from 0" can be understood / replaced as: the minimum value in the SN range (or the third SN) is 0.

[0292] "The value corresponding to the SN range is the maximum value of SN (for example, 2 X -1) ends" can be understood or replaced by: the maximum value in the SN range (or the fourth SN) is 2 X -1.

[0293] For example, in a possible implementation, the process of the terminal device determining the HFN of the first PDCP PDU includes:

[0294] Step 1: If the value corresponding to the received SN range starts from 0, then execute step 2; if not, then execute step 3;

[0295] Step 2: If the second SN is within the above SN range, the HFN of the first PDCP PDU is equal to the first HFN; otherwise, the HFN of the first PDCP PDU is equal to the first HFN minus 1;

[0296] Step 3: If the value corresponding to the received SN range is the maximum value of SN (for example, 2 X -1) ends, and if the second SN is within the above SN range, the HFN of the first PDCP PDU is equal to the first HFN, otherwise, the HFN of the first PDCP PDU is equal to the first HFN plus 1.

[0297] For example, the length of SN is 12 bits, that is, the value range of SN is 0 to 4095, and accordingly, the SN space corresponding to one HFN is 0 to 4095. The first parameter value is 2048. The received SN range is 0 to 2000, and the first HFN is equal to 11. If the received second SN is 1000, it can be seen from the above implementation method that the second SN is within the SN range, that is, 1000 is within the range of 0 to 2000. At this time, the HFN of the first PDCP PDU is equal to the first HFN, that is, the HFN of the first PDCP PDU is equal to 11; if the received second SN is 3000, the second SN is not within the SN range. At this time, the HFN of the first PDCP PDU is equal to the first HFN minus 1, that is, the HFN of the first PDCP PDU is equal to 10.

[0298] For another example, the length of SN is 12 bits, that is, the value range of SN is 0-4095, and accordingly, the SN space corresponding to one HFN is 0-4095. The first parameter value is 2048. The received SN range is 2500-4095, and the first HFN is equal to 11. If the received second SN is 3000, it can be seen from the above implementation method that the second SN is within the SN range, that is, 3000 is within the range of 2500-4095. At this time, the HFN of the first PDCP PDU is equal to the first HFN, that is, the HFN of the first PDCP PDU is equal to 11; if the received second SN is 2000, at this time, the second SN is not within the SN range, that is, 2000 is not within the range of 2500-4095, at this time, the HFN of the first PDCP PDU is equal to the first HFN plus 1, that is, the HFN of the first PDCP PDU is equal to 12.

[0299] Example a3 : The first information includes information of the COUNT range.

[0300] For example a3, there are multiple ways for the terminal device to determine the HFN of the first PDCP PDU, which are described below using way c1 and way c2 as examples.

[0301] Method c1: The terminal device determines the HFN of the first PDCP PDU, including any of the following:

[0302] If the second SN is greater than or equal to the SN corresponding to the minimum value in the COUNT range, the HFN of the first PDCP PDU is equal to the HFN corresponding to the minimum value in the COUNT range;

[0303] If the second SN is less than or equal to the SN corresponding to the maximum value in the COUNT range, the HFN of the first PDCP PDU is equal to the HFN corresponding to the maximum value in the COUNT range.

[0304] Optionally, the SN corresponding to the maximum value in the COUNT range is less than or equal to the SN corresponding to the minimum value in the COUNT range.

[0305] Optionally, the HFN corresponding to the minimum value in the COUNT range is different from the HFN corresponding to the maximum value in the COUNT range. For example, the HFN corresponding to the minimum value in the COUNT range is equal to the HFN corresponding to the maximum value in the COUNT range - 1, or the HFN corresponding to the maximum value in the COUNT range is equal to the HFN corresponding to the minimum value in the COUNT range + 1.

[0306] Optionally, the difference between the maximum value in the COUNT range and the minimum value in the COUNT range is less than or equal to 2 X or (2 X-1). The difference between the maximum value in the COUNT range and the minimum value in the COUNT range is the maximum value in the COUNT range minus the minimum value in the COUNT range.

[0307] Optionally, the minimum value in the COUNT range can be understood or replaced by the first COUNT.

[0308] Optionally, the maximum value in the COUNT range can be understood or replaced by the second COUNT.

[0309] Optionally, the SN corresponding to the minimum value in the COUNT range can be understood or replaced by any one of the fifth SN, the sixth SN, the SN corresponding to the first COUNT, the eighth SN, the ninth SN, and the ninth SN.

[0310] Optionally, the SN corresponding to the maximum value in the COUNT range can be understood or replaced by any one of the fifth SN, the seventh SN, the eighth SN, the SN corresponding to the second COUNT, the tenth SN, and the tenth SN.

[0311] Optionally, the HFN corresponding to the minimum value in the COUNT range can be understood or replaced by any one of the second HFN, the fourth HFN, the HFN corresponding to the first COUNT, the HFN corresponding to the second COUNT (or, the HFN-v corresponding to the second COUNT), the sixth HFN, and the sixth HFN (or, the sixth HFN-q).

[0312] Optionally, the HFN corresponding to the maximum value in the COUNT range can be understood or replaced by any one of the third HFN, the fifth HFN, the HFN corresponding to the first COUNT (or, the HFN corresponding to the first COUNT+v), the HFN corresponding to the second COUNT, the sixth HFN (or, the sixth HFN+q), and the sixth HFN.

[0313] For example, combined with the description in Section S501, Table 1 gives 6 possible values ​​for the SN corresponding to the minimum value in the COUNT range, the SN corresponding to the maximum value in the COUNT range, the HFN corresponding to the minimum value in the COUNT range, and the HFN corresponding to the maximum value in the COUNT range.

[0314] Table 1

[0315]

[0316]

[0317] Mode c2: The terminal device determines the HFN of the first PDCP PDU, including any one or more of the following:

[0318] The first condition is met, if the second SN is greater than or equal to the SN corresponding to the minimum value in the COUNT range, the HFN of the first PDCP PDU is equal to the HFN corresponding to the minimum value in the COUNT range;

[0319] The first condition is met: if the second SN is less than or equal to the SN corresponding to the maximum value in the COUNT range, the HFN of the first PDCP PDU is equal to the HFN corresponding to the maximum value in the COUNT range.

[0320] The first condition includes any one or more of the following:

[0321] The information of the first COUNT and the information of the second COUNT may include: information of the second HFN, information of the third HFN, and information of the fifth SN, information of the fourth HFN, information of the fifth HFN, information of the sixth SN, and information of the seventh SN; the information of the first COUNT and the information of the second COUNT may include: any one of information of the first COUNT / information of the second COUNT and information of the eighth SN, information of the sixth HFN, information of the ninth SN, and information of the tenth SN;

[0322] The SN corresponding to the maximum value in the COUNT range is less than or equal to the SN corresponding to the minimum value in the COUNT range;

[0323] The HFN corresponding to the minimum value in the COUNT range is different from the HFN corresponding to the maximum value in the COUNT range;

[0324] The difference between the maximum value in the COUNT range and the minimum value in the COUNT range is less than or equal to 2 SN比特数 or less than or equal to (2 SN比特数 -1).

[0325] S504: The terminal device sets a first state variable.

[0326] Exemplarily, the terminal device may set the first state variable according to one of the following methods:

[0327] Mode d1: setting the first state variable to the minimum value, maximum value or average value of the COUNT of the first received PDCP PDU and the COUNT corresponding to the first information;

[0328] Mode d2: setting the first state variable to the minimum value, maximum value or average value of the COUNT of the N received PDCP PDUs, where N is a positive integer;

[0329] Mode d3: setting the first state variable to the minimum value, maximum value or average value of the COUNT of the N received PDCP PDUs and the COUNT corresponding to the first information, where N is a positive integer or a non-negative integer;

[0330] Mode d4: setting the first state variable to the minimum value, maximum value or average value in the COUNT of the PDCP PDUs received in the first time period T;

[0331] Mode d5: Set the first state variable to the minimum value, maximum value or average value of the COUNT of the PDCP PDU received within the first time period T and the COUNT corresponding to the first information.

[0332] Optionally, the first state variable may be a state variable used in a PDCP data transmission process;

[0333] Optionally, the first state variable may include a state variable maintained by the terminal device (or a PDCP entity of the terminal device).

[0334] For example, the first state variable may include RX_NEXT and / or RX_DELIV.

[0335] For example, RX_NEXT may indicate the COUNT of the next PDCP PDU expected to be received.

[0336] For example, RX_DELIV may indicate the COUNT of the next PDCP PDU that has not been delivered to the upper layer and is waiting. For example, RX_DELIV may be understood as the lower limit of the reordering window.

[0337] For example, in the present application, the upper layer may include any one or more of the SDAP layer, the RRC layer, the NAS layer, and the APP layer.

[0338] It should be noted that any multiple of the above methods d1 to d5 can be combined with each other. For example, the first state variable is set to the minimum value, maximum value, or average value of the COUNT of the N PDCP PDUs received in the first time period T, where N is a positive integer. For example, the first state variable is set to the minimum value, maximum value, or average value of the COUNT of the N PDCP PDUs received in the first time period T and the COUNT corresponding to the first information, where N is a positive integer or a non-negative integer.

[0339] Exemplarily, any one or more of the first PDCP PDU, the first received PDCP PDU, the N received PDCP PDUs, the PDCP PDU received within the first time period T, the N PDCP PDUs received within the first time period T, and the first information is associated with the first PDCP entity or with the first wireless bearer and the first service.

[0340] Exemplarily, the first PDCP entity and / or the first radio bearer are associated with a first service, and the first service includes a broadcast service and / or a multicast service.

[0341] Exemplarily, the first PDCP PDU includes the first PDCP PDU received by the terminal device.

[0342] In a possible implementation, for the first PDCP PDU received (or, the N PDCP PDUs received, or, the PDCP PDUs received within the first time period T), the terminal device may determine the HFN of the PDCP PDU according to the method described in the present application; based on this method, the HFN of the PDCP PDU is aligned between the terminal device and the network device; for the PDCP PDU received thereafter, the terminal device may determine the HFN of the PDCP PDU based on the method in the prior art. It is to be understood that the present application does not limit which PDCP PDUs the terminal device uses the method described in the present application to determine the HFN of the PDCP PDU.

[0343] It should be noted that S504 can be used as a separate embodiment, or as an optional step combined with any one or more of S501 to S503, and the present invention does not limit this.

[0344] It should be noted that, for the HFN of the PDCP PDU involved in S504, the terminal device can determine the HFN of the PDCP PDU according to the method described in this application, the terminal device can also determine the HFN of the PDCP PDU based on the method in the prior art, and the terminal device can also determine the HFN of the PDCP PDU based on other methods, which is not limited here. For the HFNs of different PDCP PDUs involved in S504, different methods can also be used to determine, which is not limited here.

[0345] By adopting the above method, the terminal device receives the first information from the network device, and determines the HFN corresponding to the first PDCP PDU according to the first information and the second SN information carried in the received PDCP PDU; so that the terminal device and the network device can align the HFN or the initial value of the HFN of the PDCP PDU. The normal reception of data is guaranteed, and the packet loss or disordered delivery caused by HFN misalignment is avoided, which helps to improve reliability. In addition, it may also be beneficial to the decryption and integrity verification on the terminal device side, avoiding the packet loss problem caused by unsuccessful integrity verification, and improving reliability. In addition, compared with the solution in which the terminal device sets RX_DELIV to the COUNT provided by the network device, the above method can avoid the problem of data packet loss and / or receiving side window jamming due to unreasonable COUNT setting (for example, because some data failed to be successfully received, the window cannot slide, resulting in the inability to deliver data to the upper layer, increasing communication delay), improves the reliability of data reception, improves communication efficiency, and reduces communication delay.

[0346] Figure 6 A flow chart of a communication method provided in an embodiment of the present application is shown as follows: Figure 6 As shown, including:

[0347] S600, the network device sends a PDCP PDU to the terminal device, and correspondingly, the terminal device receives the PDCP PDU from the network device.

[0348] For example, the PDCP PDU may include / be replaced by / be understood as: a first PDCP PDU.

[0349] In this embodiment, the PDCP PDU (or the first PDCP PDU) may include (or be replaced by): a PDU header, or a PDCP PDU (or the first PDCP PDU) header, or a PDU header of the PDCP PDU (or the first PDCP PDU), or a header of the PDCP PDU (or the first PDCP PDU).

[0350] It should be noted that S600 is optional.

[0351] It should be noted that S600 may be executed before S601, or S600 and S601 may be executed simultaneously, or S600 may be executed after S601. The order of S600 and S601 is not limited in the embodiment of the present application.

[0352] S601, the network device sends first indication information to the terminal device, and correspondingly, the terminal device receives the first indication information from the network device.

[0353] The first indication information is used to indicate whether there is HFN information in the PDCP PDU (or, PDU header), or to indicate whether there is COUNT information in the PDCP PDU (or, PDU header); or, the first indication information is used to indicate a PDCP PDU (or, PDU header) format type, the format type includes a first type and / or a second type, the PDCP PDU (or, PDU header) corresponding to the first type includes HFN information or COUNT information, and the PDCP PDU (or, PDU header) corresponding to the second type does not include HFN information or COUNT information; or, the first indication information is used to indicate whether there is HFN information or COUNT information before or after the first indication information in the PDCP PDU (or, PDU header); or, the first indication information is used to indicate whether there is HFN information or COUNT information before or after the indication field of the PDCP PDU (or, PDU header); or, the first indication information is used to indicate whether the PDCP PDU (or, PDU header) includes only SN information; or, the first indication information is used to indicate whether the PDCP PDU (or, PDU header) does not include COUNT information or HFN information.

[0354] It can be understood that the description and location of the PDCP PDU in this embodiment can be replaced by "PDU header". For example, the first indication information is used to indicate whether there is HFN information in the PDCP header, or to indicate whether there is COUNT information in the PDCP header. This application does not limit this.

[0355] The indication field may include at least one of the following information (or fields): SN, reserved bit R, PDU type, data, and message authentication code for integrity MAC-I (Message Authentication Code for Integrity).

[0356] Optionally, the HFN field may include a HFN value or an HFN index.

[0357] Optionally, the HFN field may be used to indicate HFN information of the PDCP PDU.

[0358] For example, the number of bits of the HFN field (or the number of bits occupied) may be 20 bits, or 14 bits, or 16 bits. The above is only an example. The number of bits occupied by the HFN field in the PDCP PDU / PDU header and the position of the HFN field in the PDCP PDU (or, PDU header) are not limited in this application.

[0359] Optionally, the HFN field may include information of all or part of the bits of the HFN of the HFN / PDCP PDU.

[0360] Optionally, the COUNT field includes a COUNT value or an index of COUNT.

[0361] Optionally, the COUNT field may be used to indicate COUNT information of the PDCP PDU.

[0362] For example, the number of bits of the COUNT field (or the number of bits occupied) can be 32 bits. The above is only an example. The specific number of bits occupied by the COUNT field in the PDCP PDU (or, PDU header) and the position of the COUNT field in the PDCP PDU (or, PDU header) are not limited in this application.

[0363] Optionally, the COUNT field may include information of all bits or information of part bits of the COUNT (or, COUNT of the PDCP PDU).

[0364] Optionally, the SN field includes an SN value or an SN index.

[0365] Optionally, the SN field may be used to indicate information about the SN of the PDCP PDU.

[0366] For example, the number of bits of the SN field (or the number of bits occupied) may be 12 bits, 18 bits, or 16 bits. The above is only an example. The number of bits occupied by the SN field in the PDCP PDU (or, PDU header) and the position of the SN field in the PDCP PDU (or, PDU header) are not limited in this application.

[0367] Optionally, the SN field may include information about all bits or part of bits of the SN (or the SN of the PDCP PDU).

[0368] Optionally, the R field is a reserved bit.

[0369] Optionally, the PDU type field may be used to indicate whether the PDCP PDU is a PDCP data PDU or a PDCP control PDU. For example, the PDU type may be represented by D / C.

[0370] For example, the number of bits of the PDCP type field (or the number of bits occupied) can be 1 bit. The above is only an example. The specific number of bits occupied by the PDCP type field in the PDCP PDU (or, PDU header) and the position of the PDCP type field in the PDCP PDU (or, PDU header) are not limited in this application.

[0371] Optionally, the data field may include any one or more of the following: a PDCP service data unit (SDU), a compressed PDCP SDU, and an uncompressed PDCP SDU. For example, the data may be represented by Data. For example, the data field may be represented by a Data field.

[0372] For example, any one or more of the PDCP SDU, the compressed PDCP SDU, and the uncompressed PDCP SDU may include: user plane data, and / or, control plane data.

[0373] For example, the number of bits of the data field (or the number of bits occupied) may be variable. For example, the number of bits of the data field (or the number of bits occupied) may be X bytes, or 8 times Y bits, where X and / or Y may be positive integers.

[0374] Optionally, the MAC-I field can be used for integrity protection.

[0375] For example, the number of bits of the MAC-I domain (or the number of bits occupied) can be 32 bits. The above is only an example. The specific number of bits occupied by the MAC-I domain in the PDCP PDU and the position of the MAC-I domain in the PDCP PDU are not limited in this application.

[0376] Optionally, the first indication information can be carried in a variety of possible messages, such as a radio resource control RRC message, or a PDCP control PDU, or a PDCP PDU (or a first PDCP PDU), or a radio bearer configuration corresponding to the PDCP PDU (or, a radio bearer configuration corresponding to the first PDCP PDU, or, a first radio bearer configuration), or a configuration corresponding to the first service, or downlink control information (Downlink Control Information, DCI), or a media access control (media access control, MAC) control element (control element, CE), or other possible messages, without specific limitation.

[0377] The first service includes a broadcast service and / or a multicast service.

[0378] It can be understood that the first indication information is carried in the PDCP PDU (or the first PDCP PDU), and the terminal device receives the PDCP PDU (or the first PDCP PDU) and also obtains the first indication information. In this possible case, S600 and S601 can be understood as being executed simultaneously. S600 and S601 can be understood or replaced as: the network device sends a PDCP PDU to the terminal device, and accordingly, the terminal device receives a PDCP PDU from the network device, wherein the PDCP PDU includes the first indication information.

[0379] Furthermore, there are multiple specific implementations of the first indication information. As a possible implementation method, the first indication information may include one or more bits, and then indicate the content information carried by the PDCP PDU through different bit values. For example, if the first indication information indicates whether there is HFN information in the PDCP PDU, the first indication information may include one bit. When the value of the bit is "1", the HFN information exists in the indicated PDCP PDU. When the bit is set to "0", the HFN information does not exist in the indicated PDCP PDU. For another example, if the first indication information indicates the format type of the PDCP PDU, the first indication information may include one bit. When the value of the bit is "1", the indicated PDCP PDU format type is the first type. When the bit is set to "0", the indicated PDCP PDU format type is the second type. In this example, the first indication information may also include 2 bits. When the bit position is "00", the indicated PDCP PDU format type is the first type. When the bit position is "01", the indicated PDCP PDU format type is the second type. When the bit position is "10", the indicated PDCP PDU format type is the third type. When the bit position is "11", the indicated PDCP PDU format type is an existing PDCP PDU type or a reserved type. It can be understood that the above is only an example, and the specific number of bits used and the meanings corresponding to different values ​​are not limited in the embodiments of the present application.

[0380] As another possible implementation, the first indication information may include one or more fields, and further indicate the content information carried by the PDCP PDU by the presence or absence of one or more fields. For example, if the first indication information indicates whether there is HFN information in the PDCP PDU, the first indication information may include one field. If the field exists in the first indication information, it means that there is HFN information in the PDCP PDU; if the field does not exist, it means that there is no HFN information in the PDCP PDU. It can be understood that the above is only an example, and the specific number of fields used and the meaning corresponding to the presence or absence of different fields may not be limited in the embodiments of the present application.

[0381] Optionally, the above-mentioned PDCP PDU (or first PDCP PDU) may include: PDCP data PDU and / or PDCP control PDU.

[0382] For example, a PDCP data PDU may be used to transmit any one or more of the following: a PDU header, user plane data, control plane data, or a MAC-I.

[0383] For example, the PDCP control PDU may be used to transmit any one or more of the following: a PDU header, a PDCP status report, a robust header compression (ROHC) feedback, and an Ethernet Header Compression (EHC) feedback.

[0384] Optionally, the first indication information can be located at any position in the PDCP PDU (or the first PDCP PDU) / PDU header. In other words, the first indication information occupies the Zth bit in the PDCP PDU (or the first PDCP PDU) / PDU header, or the first indication information can occupy one bit or multiple bits starting from the Zth bit of the PDCP PDU (or the first PDCP PDU) / PDU header, where Z is a positive integer greater than or equal to 1.

[0385] It should be noted that the PDCP PDU may be a byte-aligned (ie, a multiple of 8 bits) bit string. Figure 7a As shown, the bit string is represented by a table, where the most significant bit is the leftmost bit in the first row of the table, and the least significant bit is the rightmost bit in the last row of the table. The most significant bit can be called the first bit, and starting from the most significant bit, in order from left to right and from top to bottom, the first bit, the second bit, the third bit, and so on.

[0386] In a possible implementation, the first indication information is located at the first bit (or the most significant bit) in the PDCP PDU (or, PDU header), and the first indication information is used to indicate whether there is HFN information in the PDCP PDU (or, PDU header). Figure 7a-7b As shown, the value of the first indication information can be set (for example, represented by H) to indicate whether there is HFN information in the PDCP PDU (or, PDU header), the HFN information occupies 14 bits, the SN information occupies 18 bits, and the HFN information can be located before the SN information. It can be understood that the HFN information can also be located after the SN information.

[0387] For example, Figure 7aAs shown, the PDCP PDU includes the following information, where each 8 bits is 1 byte:

[0388] First indication information: 1 bit;

[0389] Reserved bit: that is, reserved bit, including 7 bits;

[0390] HFN field: 14 bits;

[0391] SN field: 18 bits;

[0392] Data domain.

[0393] For example, Figure 7b As shown, the PDCP PDU includes the following information, where each 8 bits is 1 byte:

[0394] First indication information: 1 bit;

[0395] Reserved bit: that is, reserved bit, including 5 bits;

[0396] SN field: 18 bits;

[0397] Data domain.

[0398] In another possible implementation, the first indication information is located at the second bit in the PDCP PDU (or, PDU header), and the first indication information is used to indicate whether there is HFN information in the PDCP PDU (or, PDU header), and the PDCP PDU (or, PDU header) includes a D / C field and a MAC-I field. Figure 7c-7d As shown, the value of the first indication information can be set to indicate whether there is HFN information in the PDCP PDU (or, PDU header), the HFN information occupies 14 bits, the SN information occupies 18 bits, and the HFN information can be located before the SN information. It can be understood that the HFN information can also be located after the SN information.

[0399] For example, Figure 7c As shown, the PDCP PDU includes the following information, where each 8 bits is 1 byte:

[0400] PDU type field: 1 bit;

[0401] First indication information: 1 bit;

[0402] Reserved bit: that is, reserved bit, including 6 bits;

[0403] HFN field: 14 bits;

[0404] SN field: 18 bits;

[0405] Data domain;

[0406] MAC-I field: 32 bits.

[0407] For example, Figure 7d As shown, the PDCP PDU includes the following information, where each 8 bits is 1 byte:

[0408] PDU type field: 1 bit;

[0409] First indication information: 1 bit;

[0410] Reserved bit: that is, reserved bit, including 4 bits;

[0411] SN field: 18 bits;

[0412] Data domain;

[0413] MAC-I field: 32 bits.

[0414] It should be noted that the above is only an example. In the present application, any one or more of the above COUNT, HFN, SN, R, D / C, Data, and MAC-I may be optionally included in the PDCP PDU, and there is no restriction on their existence. In addition, the number of bits corresponding to the above COUNT, HFN, SN, R, D / C, Data, and MAC-I may be the above-mentioned example values ​​or other values, and the present application does not impose any restriction on this.

[0415] Optionally, the terminal device may receive a PDCP PDU corresponding to the third type from the network device, wherein the format of the PDCP PDU (or, PDU header) corresponding to the third type may have multiple implementations, which are described below using implementation a1 and implementation a2 as examples:

[0416] Implementation a1: The PDCP PDU (or PDU header) does not include the first indication information, but includes one of the following: COUNT information, or HFN information and SN information.

[0417] Optionally, the PDCP PDU (or, PDU header) may include at least one of the following: a reserved bit R, a PDU type, data, and a MAC-I.

[0418] For implementation a1, for example, Figure 7e As shown, the PDCP PDU (or, PDU header) includes a HFN field, a SN field and a Data field, wherein the HFN field occupies 14 bits and the SN field occupies 18 bits.

[0419] Implementation a2: The PDCP PDU (or PDU header) does not include the first indication information, and the PDCP PDU (or PDU header) satisfies one of the following: including SN information, not including HFN information or COUNT information, or including SN information but not including HFN information or COUNT information.

[0420] Optionally, the PDCP PDU (or, PDU header) may include at least one of the following: a reserved bit R, a PDU type, data, and a MAC-I.

[0421] For implementation a2, for example, Figure 7f As shown, the PDCP PDU includes information of a reserved bit R, a SN, and information of a Data field, wherein the reserved bit R occupies 6 bits and the SN field occupies 18 bits.

[0422] It can be understood that the above is only an example, and the number of bits corresponding to each field in the PDCP PDU corresponding to the third type may not be limited.

[0423] It should be noted that if the network device always carries HFN information or COUNT information in the PDCP PDU (or, PDU header), it can ensure that the HFN is aligned between the terminal device and the network device, but this will cause a large overhead on air interface resources and waste resources. Therefore, the first indication information can be added to the PDCP PDU / PDU header, which is used by the terminal device to determine whether the PDCP PDU (or, PDU header) contains HFN information or COUNT information, or it is used by the terminal device to determine the format of the PDCP PDU (or, PDU header) so as to correctly decode the PDCP PDU (or, PDU header). In this case, the network device can carry HFN information or COUNT information in the PDCP PDU (or, PDU header) when necessary, so that the network device and the terminal device can align HFN; when not needed (for example, the terminal device corresponding to the first service or the first radio bearer has aligned HFN with the network device), the HFN information or COUNT information may not be carried in the PDCP PDU (or, PDU header). In this way, the overhead of air interface resources can be saved.

[0424] When the network device carries HFN information or COUNT information in the PDCP PDU (or, PDU header), and when it does not carry HFN information or COUNT information in the PDCP PDU (or, PDU header), can be determined by the network device according to certain parameters, or depends on the implementation of the network device. Here, certain parameters may include at least one of the following: feedback information of the terminal device (for example, ACK or NACK), the number of terminal devices that send feedback information, the time when the network device sends the first indication information, and the number of PDCP PDUs sent that carry HFN information or COUNT information. Among them, the feedback information includes at least one of the following: hybrid automatic repeat request (HARQ) feedback, channel state information (CSI), rank indication (RI), RLC status report, and PDCP status report.

[0425] For example, the network device determines that a new terminal device is interested in the data corresponding to the first service or the first radio bearer, or the network device determines that a new terminal device will receive the data corresponding to the first service or the first radio bearer, and the network device can carry HFN information or COUNT information in the PDCP PDU (or, PDU header) sent to the terminal device. For example, the PDCP PDU sent to the terminal device may include: a PDCP PDU sent to the terminal device via a point-to-point (PTP) mode or a PDCP PDU sent to the terminal device via a point-to-multipoint (PTM) mode.

[0426] For example, the network device determines that it will start transmitting data corresponding to the first service or the first radio bearer, and the network device may carry HFN information or COUNT information in the PDCP PDU / PDU header sent to (one or more) terminal devices. For example, the PDCP PDU sent to (one or more) terminal devices may include: a PDCP PDU sent to (one or more) terminal devices respectively in a PTP manner or a PDCP PDU sent to (one or more) terminal devices in a PTM manner.

[0427] For example, the network device can determine, based on feedback from the terminal device, that each terminal device receiving data corresponding to the first service or the first wireless bearer has received at least one PDCP PDU containing HFN information or COUNT information, so that the network device can determine not to carry HFN information or COUNT information in the PDCP PDU / PDU header.

[0428] For example, the network device can determine, based on feedback from the terminal device, that the terminal device receiving the data corresponding to the first service or the first wireless bearer has received at least one PDCP PDU containing HFN information or COUNT information, so that the network device can determine not to carry HFN information or COUNT information in the PDCP PDU (or, PDU header).

[0429] For another example, the network device may determine that the HFN information or COUNT information is not carried in the PDCP PDU subsequently according to the time when the PDCP PDU carrying the HFN information or COUNT information sent is greater than a preset threshold. Specifically, the network device may determine that the HFN information or COUNT information is not carried in the PDCP PDU / PDU header.

[0430] For another example, the network device may determine that the HFN information or COUNT information is not carried in the PDCP PDU (or, PDU header) subsequently based on the number of PDCP PDUs carrying HFN information or COUNT information sent being greater than a preset threshold. Specifically, the network device may determine that the HFN information or COUNT information is not carried in the PDCP PDU (or, PDU header).

[0431] For example, the number of sent PDCP PDUs carrying HFN information or COUNT information may include: the number of continuously sent PDCP PDUs carrying HFN information or COUNT information.

[0432] S602: The terminal device decodes the PDCP PDU according to the first indication information.

[0433] It should be noted that, as an optional step, in S602, after receiving the first indication information, the terminal device can determine or obtain the format of the PDCP PDU (or, PDU header) (or the format type of the PDU header of the PDCP PDU, or the format type of the PDU header). In other words, the terminal device can obtain the content included in the PDCP PDU (or, PDU header) (for example, whether it includes HFN) based on the first indication information, and then decode the PDCP PDU (or, PDU header) based on the first indication information.

[0434] In this way, the terminal device can obtain the PDCP PDU (or the format of the PDU header, or the content information carried) before decoding the PDCP PDU (or, PDU header), and can correctly decode the meaning of each field in the PDCP PDU (or, PDU header), or in other words, can correctly decode the PDCP PDU.

[0435] It should be noted that S602 can be understood or replaced as: the terminal device can determine, according to the first indication information: whether there is HFN information in the PDCP PDU (or, PDU header), or whether there is COUNT information in the PDCP PDU (or, PDU header); or, the PDCP PDU (or, PDU header) format type, the format type includes the first type and / or the second type, the PDCP PDU (or, PDU header) corresponding to the first type includes HFN information or COUNT information, and the PDCP PDU (or, PDU header) corresponding to the second type does not include HFN information or COUNT information; or, whether there is HFN information or COUNT information before or after the first indication information in the PDCP PDU (or, PDU header); or, whether there is HFN information or COUNT information before or after the indication field of the PDCP PDU (or, PDU header); or, whether the PDCP PDU (or, PDU header) includes only SN information; or whether the PDCP PDU (or, PDU header) does not include COUNT information or HFN information.

[0436] S603: The terminal device sends capability information to the network device.

[0437] Correspondingly, the network device receives the capability information sent by the terminal device.

[0438] S603 is optional.

[0439] The capability information is used to indicate whether the terminal device supports format type conversion, or to indicate the format type supported by the terminal device, or to indicate whether the terminal device only supports the first type, or the format type or PDCP PDU format type or PDU header format type that the terminal device will receive, wants to receive, or can receive. Here, the format type may include at least one of the first type, the second type, or the third type. For the description of the first type, the second type, and the third type, please refer to the relevant description in S601, which will not be repeated here.

[0440] For example, whether the terminal device supports format type conversion can be understood as: whether the terminal device supports the first type and / or the second type of format type; or, whether the terminal device supports the PDCP PDU (or, PDCP PDU format) carrying the first indication information; or, whether the terminal device supports the PDCP PDU (or, PDCP PDU format) carrying HFN information or COUNT information.

[0441] Optionally, the capability information may be carried in a variety of possible messages, such as a Radio Resource Control (RRC) message or other possible messages, which are not specifically limited.

[0442] It should be noted that S603 can be used as a separate embodiment, or as an optional step combined with any one or more of S600, S601, and S604, and the present invention is not limited to this.

[0443] S604: The terminal device receives second indication information from the network device.

[0444] Correspondingly, the network device sends second indication information to the terminal device.

[0445] S604 is optional.

[0446] The second indication information is used to indicate whether the network device supports format type conversion, or to indicate the format type supported by the network device, or to indicate whether the network device only supports the first type, or the format type or PDCP PDU format type or PDU header format type that the network device will send or wants to send or is able to send.

[0447] For example, whether the network device supports format type conversion can be understood as whether the network device supports the first type and / or the second type of format type; or, whether the network device supports the PDCP PDU (or, PDCP PDU format) carrying the first indication information; or, whether the network device supports the PDCP PDU (or, PDCP PDU format) carrying HFN information or COUNT information.

[0448] Optionally, the second indication information can be carried in a variety of possible messages, such as a radio resource control RRC message, or a PDCP control PDU, or a PDCP PDU (or a first PDCP PDU), or a radio bearer configuration corresponding to the PDCP PDU (or, a radio bearer configuration corresponding to the first PDCP PDU, or, a first radio bearer configuration), or a configuration corresponding to the first service, or downlink control information (Downlink Control Information, DCI), or a media access control (media access control, MAC) control element (control element, CE), or other possible messages, without specific limitation.

[0449] It should be noted that S604 can be used as a separate embodiment, or as an optional step combined with any one or more of S600, S601, and S603, and the present invention does not limit this.

[0450] Optionally, any one or more of the first indication information, the second indication information, the format type, the capability information, and the PDCP PDU (or the first PDCP PDU) are associated with any one or more of the first PDCP entity, the first radio bearer, and the first service.

[0451] Optionally, the first PDCP entity and / or the first radio bearer are associated with the first service.

[0452] Optionally, the first PDCP PDU is associated with a first channel (or a first logical channel).

[0453] The first channel (or first logical channel) may include a channel associated with any one or more of the first service, the first PDCP entity, and the first radio bearer. For example, the first channel may include a multicast broadcast service channel and / or a dedicated traffic channel (Dedicated Traffic Channel, DTCH).

[0454] For example, the channel associated with the first service may include: a channel associated with unicast transmission of the first service and / or a channel associated with multicast transmission of the first service.

[0455] It should be noted that the multicast broadcast service channel can be replaced by: a channel for broadcast and / or multicast, or a logical channel for broadcast and / or multicast services (eg, a channel for transmitting services).

[0456] In a possible implementation, the first channel is a multicast traffic channel (MTCH).

[0457] Optionally, the first PDCP PDU is associated with a first RLC entity. The first RLC entity may include an RLC entity associated with the first service.

[0458] In a possible implementation, the first RLC entity is associated with a multicast broadcast service channel corresponding to the first service (or first radio bearer).

[0459] In a possible implementation, the first RLC entity is associated with a dedicated service channel corresponding to the first service (or first radio bearer).

[0460] It should be noted that S604 can be executed before S603, or S604 and S603 can be executed at the same time, or S601 can be executed after S604, or S601 can be executed after S603. The order of S601, S603 and S604 is not limited in the embodiment of the present application.

[0461] It should be noted that the present application does not limit the order of HFN and SN in the PDCP PDU, nor does it limit the order of HFN and SN to be adjacent. The above is only an example, and it can be understood that the order of HFN and SN can be reversed. There can be a gap between HFN and SN, or there can be no gap.

[0462] By adopting the above method, the terminal device receives the first indication information from the network device, and determines whether the PDCP PDU (or, PDU header) carries HFN information or COUNT information according to the first indication information. If the PDCP PDU (or, PDU header) carries HFN information or COUNT information, the terminal device can determine the HFN of the received PDCP PDU according to the HFN information or COUNT information. In this way, on the one hand, by carrying HFN information or COUNT information in the PDCP PDU / PDU header, the terminal device can accurately determine the HFN of the received PDCP PDU, and the HFN maintenance between the terminal device and the network device is simpler and / or more flexible, ensuring the normal reception of data, avoiding the problem of packet loss or disordered delivery caused by HFN misalignment, and helping to improve reliability. In addition, it may also be beneficial to the decryption and integrity verification on the terminal device side, avoiding the problem of packet loss due to unsuccessful integrity verification, and improving reliability. In addition, compared with the solution in which the terminal device sets RX_DELIV to the COUNT provided by the network device, the above method can avoid the problem of data packet loss and / or receiving side window jamming due to unreasonable COUNT setting (for example, because some data failed to be successfully received, the window cannot slide, resulting in the inability to deliver data to the upper layer, increasing communication delay), thereby improving the reliability of data reception, improving communication efficiency, and reducing communication delay. On the other hand, by introducing the first indication information, the PDCP PDU (or, PDU header) does not need to carry HFN information or COUNT information all the time, which can reduce the overhead of air interface resources. At the same time, the terminal device can correctly determine the format of the PDCP PDU (or, PDU header), so that the PDCP PDU (or, PDU header) can be correctly decoded, thereby improving the reliability of data reception.

[0463] It can be understood that the above-mentioned embodiments can be combined with each other.

[0464] Figure 8 A flow chart of another communication method provided in an embodiment of the present application is as follows: Figure 8 As shown, including:

[0465] S801, optionally, the terminal device sends capability information to the network device.

[0466] Correspondingly, the network device receives the capability information sent by the terminal device.

[0467] S801 is optional.

[0468] It should be noted that the above content related to capability information can be referred to Figure 6 The relevant description will not be repeated here.

[0469] S802, optionally, the terminal device receives second indication information from the network device.

[0470] Correspondingly, the network device sends second indication information to the terminal device.

[0471] S802 is optional.

[0472] It should be noted that the content related to the second indication information can be referred to Figure 6 The relevant description will not be repeated here.

[0473] S803, optionally, the network device determines to send a third type of PDCP PDU.

[0474] Optionally, the network device may determine whether to send the third type of PDCP PDU based on the capability information sent by the terminal device.

[0475] For example, the network device determines that the terminal device does not support the first type and / or the second type of PDCP PDU, and the network device sends a third type of PDCP PDU.

[0476] Optionally, the network device determines when to send the third type of PDCP PDU and how long to send the third type of PDCP PDU, which may be determined by the network device according to a preset rule or depend on the implementation of the network device.

[0477] Optionally, the network device may determine to send the third type of PDCP PDU based on at least one of the following: the number of feedback information of the terminal devices, the number of terminal devices sending feedback information, and the time when the network device sends the first indication information. The feedback information includes at least one of the following: hybrid automatic repeat request (HARQ), channel state information (CSI), and rank indication (RI).

[0478] For example, the network device can determine that each UE in a service (such as MBS) group has received a PDCP PDU containing MBS data based on the number of HARQ feedbacks from the terminal device, so that the network device can determine not to carry HFN information or COUNT information in the PDCP PDU.

[0479] For another example, the network device may determine not to carry the HFN information or COUNT information in the subsequent PDCP PDU according to the time of sending the PDCP PDU carrying the HFN information or COUNT information being greater than a preset threshold.

[0480] S804: The network device sends a third type of PDCP PDU to the terminal device.

[0481] Accordingly, the terminal device receives the third type of PDCP PDU from the network device.

[0482] It should be noted that the possible implementation of the third type of PDCP PDU can refer to Figure 6 The relevant description will not be repeated here.

[0483] Through this method, the network device can send the third type of PDCP PDU to the terminal device, enriching the sending method of PDCP PDU. In addition, the network device can further send the third type of PDCP PDU to the terminal device according to the capability of the terminal device, which can avoid the network device sending a PDCP PDU of a type that it does not support to the terminal device, such as the first type and / or the second type of PDCP PDU. Optionally, the terminal device can also align the HFN with the network device based on the third type of PDCP PDU.

[0484] It should be noted that S804 and S803 may be executed simultaneously, or S804 may be executed after S803. The sequence of S803 and S804 is not limited in the embodiment of the present application.

[0485] It should be noted that (1) Figure 5 , Figure 6 , Figure 8 The corresponding embodiments may be implemented separately or in combination (for example Figure 5 All or part of the schemes involved in Figure 8 The corresponding embodiments are combined), and no specific limitation is made.

[0486] (2) The various flow charts described in the embodiments of this application (such as Figure 5 , Figure 6 , Figure 8 ) is only an example of the execution process and does not constitute a limitation on the order of execution of the steps. In the embodiments of the present application, there is no strict execution order between the steps that have no timing dependency on each other.

[0487] In view of the above method flow, the present application also provides a communication device, which is used to execute the above method flow.

[0488] Fig. 9 A possible exemplary block diagram of the device involved in the embodiments of the present application is shown. Fig. 9 As shown, the device 900 may include: a transceiver unit 920 and a processing unit 910. The processing unit 910 is used to control and manage the actions of the device 900. The transceiver unit 920 may include a receiving unit and / or a sending unit, which are used to perform receiving and sending operations respectively. The elements of the transceiver unit 920 may be a receiver or a transceiver, and the hardware elements of the processing unit 910 may be a processor.

[0489] The communication device 900 may be a terminal device in the above embodiment, or may be a chip set in the terminal device, and the device 900 may execute the process corresponding to the terminal device in the above method embodiment. The processing unit 910 may support the device 900 to execute the actions of the terminal device in each method example above. Alternatively, the processing unit 910 mainly executes the internal actions of the terminal device in the method example, and the transceiver unit 920 may support the communication between the device 900 and other devices.

[0490] Specifically, in one embodiment, the transceiver unit 920 is used to receive first information from the network device, where the first information includes any one of the following:

[0491] Information of the first HFN and information of the first SN; or,

[0492] Information of the first HFN and information of the SN range; or,

[0493] COUNT range information;

[0494] The transceiver unit 920 is further configured to receive a first PDCP PDU from the network device, where the first PDCP PDU includes a second SN;

[0495] The processing unit 910 is configured to determine the HFN of the first PDCP PDU according to the first information and the second SN.

[0496] In a possible design, the first information includes information of a first HFN and information of a first SN, and the processing unit 910 is specifically configured to determine, according to the first information and the second SN, the HFN of the first PDCP PDU, including any one or more of the following:

[0497] If the second SN is less than the difference between the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN plus 1;

[0498] If the second SN is greater than or equal to the sum of the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN minus 1;

[0499] If the second SN is greater than or equal to a difference between the first SN and a first parameter, and / or the second SN is less than a sum of the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN.

[0500] In one possible design, the first information includes: information of a first HFN and information of an SN range, and the processing unit 910 is specifically configured to determine, according to the first information and the second SN, the HFN of the first PDCP PDU, including any one or more of the following:

[0501] If the second SN is within the SN range, the HFN of the first PDCP PDU is equal to the first HFN;

[0502] If the second SN is less than a minimum value in the SN range, the HFN of the first PDCP PDU is equal to the first HFN plus 1;

[0503] If the second SN is greater than a maximum value in the SN range, the HFN of the first PDCP PDU is equal to the first HFN minus 1.

[0504] In one possible design, the first information includes information of a COUNT range, and the processing unit 910 is specifically configured to determine, according to the first information and the second SN, the HFN of the first PDCP PDU, including any one or more of the following:

[0505] If the second SN is greater than or equal to the SN corresponding to the minimum value in the COUNT range, the HFN of the first PDCP PDU is equal to the HFN corresponding to the minimum value in the COUNT range;

[0506] If the second SN is less than or equal to the SN corresponding to the maximum value in the COUNT range, the HFN of the first PDCP PDU is equal to the HFN corresponding to the maximum value in the COUNT range.

[0507] In one possible design, the processing unit 910 is further configured to:

[0508] Set the first state variable according to one of the following methods:

[0509] Setting the minimum value or the maximum value between the COUNT of the first received PDCP PDU and the COUNT corresponding to the first information as the first state variable;

[0510] Setting the minimum value or the maximum value in the COUNT of the N received PDCP PDUs as the first state variable, where N is a positive integer;

[0511] Set the minimum value or the maximum value between the COUNT of the N received PDCP PDUs and the COUNT corresponding to the first information as the first state variable, where N is a positive integer;

[0512] Setting the minimum value or the maximum value in the COUNT of the PDCP PDUs received in the first time period T as the first state variable;

[0513] The minimum value or the maximum value between the COUNT of the PDCP PDU received in the first time period T and the COUNT corresponding to the first information is set as the first state variable.

[0514] In one possible design, any one or more of the first PDCP PDU, the first received PDCP PDU, the received N PDCP PDUs, the PDCP PDU received within the first time period T, and the first information is associated with a first PDCP entity or with a first wireless bearer.

[0515] In one possible design, the first PDCP entity and / or the first wireless bearer is associated with a first service, and the first service includes a broadcast service and / or a multicast service.

[0516] Specifically, in another embodiment, the transceiver unit 920 is configured to receive first indication information from a network device, where the first indication information is used to indicate whether there is HFN information in the PDCP PDU, or to indicate whether there is COUNT information in the PDCP PDU; or,

[0517] The first indication information is used to indicate a PDCP PDU format type, the format type includes a first type and / or a second type, the PDCP PDU corresponding to the first type includes HFN information or COUNT information, and the PDCP PDU corresponding to the second type does not include the HFN information or COUNT information; or,

[0518] The first indication information is used to indicate whether there is HFN information or COUNT information before or after the first indication information in the PDCP PDU; or,

[0519] The first indication information is used to indicate whether there is HFN information or COUNT information before or after the indication field of the PDCP PDU;

[0520] The indication field includes at least one of the following information: SN, reserved bit R, PDU type, data, and integrity message authentication code MAC-I.

[0521] In one possible design, the transceiver unit 920 is also used to send capability information to the network device, wherein the capability information is used to indicate whether the terminal device supports format type conversion, or to indicate the format type supported by the terminal device, or to indicate whether the terminal device only supports the first type.

[0522] In one possible design, the transceiver unit 920 is also used to receive second indication information from the network device, wherein the second indication information is used to indicate whether the network device supports format type conversion, or to indicate the format type supported by the network device, or to indicate whether the network device only supports the first type.

[0523] Fig.10 A possible exemplary block diagram of the device involved in the embodiments of the present application is shown. Fig.10 As shown, the device 1000 may include: a transceiver unit 1020 and a processing unit 1010. The processing unit 1010 is used to control and manage the actions of the device 1000, and the transceiver unit 1020 may include a receiving unit and / or a sending unit, which are respectively used to perform receiving and sending operations. The elements of the transceiver unit 1020 may be a receiver or a transceiver, and the hardware elements of the processing unit 1010 may be a processor.

[0524] The communication device 1000 may be a network device in the above embodiment, or may be a chip set in the network device, and the device 1000 may execute the process corresponding to the network device in the above method embodiment. The processing unit 1010 may support the device 1000 to execute the actions of the network device in each method example above. Alternatively, the processing unit 1010 mainly executes the internal actions of the network device in the method example, and the transceiver unit 1020 may support the communication between the device 1000 and other devices.

[0525] Specifically, in one embodiment, the transceiver unit 1020 is used to send first information to the terminal device, where the first information includes any one of the following:

[0526] Information of the first HFN and information of the first SN; or,

[0527] Information of the first HFN and information of the SN range; or,

[0528] COUNT range information;

[0529] The transceiver unit 1020 is further used to send a first PDCP PDU to the terminal device, where the first PDCP PDU includes a second SN.

[0530] Specifically, in another embodiment, the transceiver unit 1020 is configured to receive first indication information from a network device, where the first indication information is used to indicate whether there is HFN information in the PDCP PDU, or to indicate whether there is COUNT information in the PDCP PDU; or,

[0531] The first indication information is used to indicate a PDCP PDU format type, the format type includes a first type and / or a second type, the PDCP PDU corresponding to the first type includes HFN information or COUNT information, and the PDCP PDU corresponding to the second type does not include the HFN information or COUNT information; or,

[0532] The first indication information is used to indicate whether there is HFN information or COUNT information before or after the first indication information in the PDCP PDU; or,

[0533] The first indication information is used to indicate whether there is HFN information or COUNT information before or after the indication field of the PDCP PDU;

[0534] The indication field includes at least one of the following information: SN, reserved bit R, PDU type, data, and integrity message authentication code MAC-I.

[0535] In one possible design, the transceiver unit 1020 is also used to receive capability information sent by the terminal device, and the capability information is used to indicate whether the terminal device supports format type conversion, or to indicate the format type supported by the terminal device, or to indicate whether the terminal device only supports the first type.

[0536] In one possible design, the transceiver unit 1020 is also used to send second indication information to the terminal device, wherein the second indication information is used to indicate whether the network device supports format type conversion, or to indicate the format type supported by the network device, or to indicate whether the network device only supports the first type.

[0537] When the communication device is a UE, Fig.11 A simplified UE structure diagram is shown. For ease of understanding and illustration, Fig.11 In the example, UE takes a mobile phone as an example. Fig.11As shown, the UE includes a processor, a memory, a radio frequency circuit, an antenna, and an input-output device. The processor is mainly used to process communication protocols and communication data, as well as to control the UE, execute software programs, process software program data, etc. The memory is mainly used to store software programs and data. The radio frequency circuit is mainly used for conversion between baseband signals and radio frequency signals and processing of radio frequency signals. The antenna is mainly used to send and receive radio frequency signals in the form of electromagnetic waves. Input-output devices, such as touch screens, display screens, keyboards, etc., are mainly used to receive data input by users and output data to users. It should be noted that some types of UE may not have input-output devices.

[0538] When data needs to be sent, the processor performs baseband processing on the data to be sent, and then outputs the baseband signal to the RF circuit. The RF circuit performs RF processing on the baseband signal and then sends the RF signal outward in the form of electromagnetic waves through the antenna. When data is sent to the UE, the RF circuit receives the RF signal through the antenna, converts the RF signal into a baseband signal, and outputs the baseband signal to the processor. The processor converts the baseband signal into data and processes the data. For ease of explanation, Fig.11 Only one memory and processor are shown. In an actual UE product, there may be one or more processors and one or more memories. The memory may also be referred to as a storage medium or a storage device, etc. The memory may be set independently of the processor or may be integrated with the processor, which is not limited in the embodiments of the present application.

[0539] Please refer to Fig.12 , which is a schematic diagram of the structure of a terminal device provided in an embodiment of the present application. It can be the terminal device in the above embodiment, and is used to implement the operation of the terminal device in the above embodiment. Figure 3 As shown, the terminal device includes: an antenna 1210, a radio frequency part 1220, and a signal processing part 1230. The antenna 1210 is connected to the radio frequency part 1220. In the downlink direction, the radio frequency part 1220 receives information sent by the network device through the antenna 1210, and sends the information sent by the network device to the signal processing part 1230 for processing. In the uplink direction, the signal processing part 1230 processes the information of the terminal device and sends it to the radio frequency part 1220. The radio frequency part 1220 processes the information of the terminal device and sends it to the network device through the antenna 1210.

[0540] The signal processing part 1230 may include a modulation and demodulation subsystem for processing each communication protocol layer of the data; it may also include a central processing subsystem for processing the operating system and application layer of the terminal device; in addition, it may also include other subsystems, such as a multimedia subsystem, a peripheral subsystem, etc., wherein the multimedia subsystem is used to control the camera, screen display, etc. of the terminal device, and the peripheral subsystem is used to connect to other devices. The modulation and demodulation subsystem may be a separately set chip. Optionally, the above device for the terminal device may be located in the modulation and demodulation subsystem.

[0541] The modem subsystem may include one or more processing elements 1231, for example, including a main control CPU and other integrated circuits. In addition, the modem subsystem may also include a storage element 1232 and an interface circuit 1233. The storage element 1232 is used to store data and programs, but the program for executing the method executed by the terminal device in the above method may not be stored in the storage element 1232, but stored in a memory outside the modem subsystem, and loaded and used by the modem subsystem when used. The interface circuit 1233 is used to communicate with other subsystems. The above device for the terminal device may be located in the modem subsystem, and the modem subsystem may be implemented by a chip, which includes at least one processing element and an interface circuit, wherein the processing element is used to execute each step of any method executed by the above terminal device, and the interface circuit is used to communicate with other devices. In one implementation, the unit for the terminal device to implement each step in the above method can be implemented in the form of a processing element scheduling program, for example, the device for the terminal device includes a processing element and a storage element, and the processing element calls the program stored in the storage element to execute the method executed by the terminal device in the above method embodiment. The storage element may be a storage element on the same chip as the processing element, that is, an on-chip storage element.

[0542] In another implementation, the program for executing the method executed by the terminal device in the above method can be in a storage element on a different chip from the processing element, that is, an off-chip storage element. In this case, the processing element calls or loads the program from the off-chip storage element to the on-chip storage element to call and execute the method executed by the terminal device in the above method embodiment.

[0543] In another implementation, the unit of the terminal device implementing each step in the above method may be configured as one or more processing elements, which are arranged on the modulation and demodulation subsystem. The processing elements here may be integrated circuits, such as one or more ASICs, or one or more DSPs, or one or more FPGAs, or a combination of these integrated circuits. These integrated circuits may be integrated together to form a chip.

[0544] The units of the terminal device implementing the various steps in the above method can be integrated together and implemented in the form of a system-on-a-chip (SOC), and the SOC chip is used to implement the above method. The chip can integrate at least one processing element and a storage element, and the method executed by the above terminal device can be implemented in the form of a program stored in the storage element by the processing element; or, the chip can integrate at least one integrated circuit to implement the method executed by the above terminal device; or, the above implementation methods can be combined, and the functions of some units can be implemented in the form of a processing element calling a program, and the functions of some units can be implemented in the form of an integrated circuit.

[0545] It can be seen that the above apparatus for terminal equipment may include at least one processing element and an interface circuit, wherein at least one processing element is used to execute any of the methods performed by the terminal equipment provided in the above method embodiments. The processing element may execute part or all of the steps performed by the terminal equipment in a first manner: that is, by calling a program stored in a storage element; or in a second manner: that is, by combining an integrated logic circuit of hardware in a processor element with instructions to execute part or all of the steps performed by the terminal equipment; of course, the first manner and the second manner may also be combined to execute part or all of the steps performed by the terminal equipment.

[0546] The processing element here is the same as described above, and can be a general-purpose processor, such as a CPU, or can be one or more integrated circuits configured to implement the above method, such as: one or more ASICs, or, one or more microprocessors DSPs, or, one or more FPGAs, etc., or a combination of at least two of these integrated circuit forms.

[0547] A storage element may be a memory or a collective term for multiple storage elements.

[0548] Please refer to Fig.13 , which is a schematic diagram of the structure of a network device provided in an embodiment of the present application. It is used to implement the operation of the network device (such as the second network device) in the above embodiment. Fig.13 As shown, the network device includes: an antenna 1301, a radio frequency device 1302, and a baseband device 1303. The antenna 1301 is connected to the radio frequency device 1302. In the uplink direction, the radio frequency device 1302 receives information sent by the terminal device through the antenna 1301, and sends the information sent by the terminal device to the baseband device 1303 for processing. In the downlink direction, the baseband device 1303 processes the information of the terminal device and sends it to the radio frequency device 1302, and the radio frequency device 1302 processes the information of the terminal device and sends it to the terminal device through the antenna 1301.

[0549] The baseband device 1303 may include one or more processing elements 13031, for example, including a main control CPU and other integrated circuits. In addition, the baseband device 1303 may also include a storage element 13032 and an interface 13033, the storage element 13032 is used to store programs and data; the interface 13033 is used to interact with the radio frequency device 1302. The interface is, for example, a common public radio interface (CPRI). The above device for the network device may be located in the baseband device 1303. For example, the above device for the network device may be a chip on the baseband device 1303, the chip includes at least one processing element and an interface circuit, wherein the processing element is used to execute each step of any method executed by the above network device, and the interface circuit is used to communicate with other devices. In one implementation, the unit for the network device to implement each step in the above method can be implemented in the form of a processing element scheduler. For example, the device for the network device includes a processing element and a storage element, and the processing element calls the program stored in the storage element to execute the method executed by the network device in the above method embodiment. The storage element may be a storage element on the same chip as the processing element, ie, an on-chip storage element, or may be a storage element on a different chip from the processing element, ie, an off-chip storage element.

[0550] In another implementation, the unit of the network device implementing each step in the above method may be configured as one or more processing elements, which are arranged on the baseband device. The processing elements here may be integrated circuits, such as one or more ASICs, or one or more DSPs, or one or more FPGAs, or a combination of these integrated circuits. These integrated circuits may be integrated together to form a chip.

[0551] The units of the network device implementing the various steps in the above method can be integrated together and implemented in the form of a system-on-a-chip (SOC). For example, the baseband device includes the SOC chip to implement the above method. The chip can integrate at least one processing element and a storage element, and the processing element calls the stored program of the storage element to implement the method executed by the above network device; or, the chip can integrate at least one integrated circuit to implement the method executed by the above network device; or, the above implementation methods can be combined, and the functions of some units are implemented by the processing element calling the program, and the functions of some units are implemented by the integrated circuit.

[0552] It can be seen that the above apparatus for network equipment may include at least one processing element and an interface circuit, wherein at least one processing element is used to execute any one of the methods performed by the network equipment provided in the above method embodiments. The processing element may execute part or all of the steps performed by the network equipment in a first manner: that is, by calling a program stored in a storage element; or in a second manner: that is, by combining an integrated logic circuit of hardware in a processor element with instructions to execute part or all of the steps performed by the network equipment; of course, the first manner and the second manner may be combined to execute part or all of the steps performed by the above network equipment.

[0553] The processing element here is the same as described above, and can be a general-purpose processor, such as a CPU, or can be one or more integrated circuits configured to implement the above method, such as: one or more ASICs, or, one or more microprocessors DSPs, or, one or more FPGAs, etc., or a combination of at least two of these integrated circuit forms.

[0554] A storage element may be a memory or a collective term for multiple storage elements.

[0555] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state hard disk Solid State Disk (SSD)), etc.

Claims

1. A communication method, characterized in that: Applied to terminal equipment, including: Receiving first information from a network device, wherein the first information includes information of a count range COUNT; receiving a first packet data convergence layer protocol PDCP protocol data unit PDU from the network device, wherein the first PDCP PDU includes a second sequence number SN; If the second SN is greater than or equal to the SN corresponding to the minimum value in the COUNT range, the HFN of the first PDCP PDU is equal to the HFN corresponding to the minimum value in the COUNT range; If the second SN is less than or equal to the SN corresponding to the maximum value in the COUNT range, the HFN of the first PDCP PDU is equal to the HFN corresponding to the maximum value in the COUNT range.

2. A communication method, characterized in that: Applied to terminal equipment, including: receiving first information from a network device, wherein the first information includes information of a first superframe number HFN and information of a first sequence number SN; receiving a first packet data convergence layer protocol PDCP protocol data unit PDU from the network device, wherein the first PDCP PDU includes a second SN; If the second SN is less than the difference between the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN plus 1; If the second SN is greater than or equal to the sum of the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN minus 1; If the second SN is greater than or equal to a difference between the first SN and a first parameter, and / or the second SN is less than a sum of the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN.

3. A communication method, characterized in that: Applied to terminal equipment, including: Receive first information from a network device, wherein the first information includes: information about a first superframe number HFN and information about a sequence number SN range; receiving a first packet data convergence layer protocol PDCP protocol data unit PDU from the network device, wherein the first PDCP PDU includes a second SN; If the second SN is within the SN range, the HFN of the first PDCP PDU is equal to the first HFN; If the second SN is less than a minimum value in the SN range, the HFN of the first PDCP PDU is equal to the first HFN plus 1; If the second SN is greater than a maximum value in the SN range, the HFN of the first PDCP PDU is equal to the first HFN minus 1.

4. The method according to any one of claims 1 to 3, characterized in that The method further comprises: Set the first state variable according to one of the following methods: Setting the minimum value or the maximum value between the COUNT of the first received PDCP PDU and the COUNT corresponding to the first information as the first state variable; Setting the minimum value or the maximum value in the COUNT of the N received PDCP PDUs as the first state variable, where N is a positive integer; Set the minimum value or the maximum value between the COUNT of the N received PDCP PDUs and the COUNT corresponding to the first information as the first state variable, where N is a positive integer; Setting the minimum value or the maximum value in the COUNT of the PDCP PDUs received in the first time period T as the first state variable; The minimum value or the maximum value between the COUNT of the PDCP PDU received in the first time period T and the COUNT corresponding to the first information is set as the first state variable.

5. The method according to claim 4, characterized in that Any one or more of the first PDCP PDU, the first received PDCP PDU, the N received PDCP PDUs, the PDCP PDUs received within the first time period T, and the first information is associated with the first PDCP entity or the first radio bearer.

6. The method according to claim 5, characterized in that The first PDCP entity and / or the first radio bearer are associated with a first service, and the first service includes a broadcast service and / or a multicast service.

7. A communication method, characterized in that: Applied to network equipment, including: Sending first information to the terminal device, where the first information includes information of a COUNT range; Sending a first PDCP PDU to the terminal device, where the first PDCP PDU includes a second SN; If the second SN is greater than or equal to the SN corresponding to the minimum value in the COUNT range, the HFN of the first PDCP PDU is equal to the HFN corresponding to the minimum value in the COUNT range; If the second SN is less than or equal to the SN corresponding to the maximum value in the COUNT range, the HFN of the first PDCP PDU is equal to the HFN corresponding to the maximum value in the COUNT range.

8. A communication method, characterized in that: Applied to network equipment, including: Sending first information to the terminal device, where the first information includes information about the first HFN and information about the first SN; Sending a first PDCP PDU to the terminal device, where the first PDCP PDU includes a second SN; If the second SN is less than the difference between the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN plus 1; If the second SN is greater than or equal to the sum of the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN minus 1; If the second SN is greater than or equal to a difference between the first SN and a first parameter, and / or the second SN is less than a sum of the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN.

9. A communication method, characterized in that: Applied to network equipment, including: Sending first information to the terminal device, where the first information includes information about the first HFN and information about the SN range; Sending a first PDCP PDU to the terminal device, where the first PDCP PDU includes a second SN; If the second SN is within the SN range, the HFN of the first PDCP PDU is equal to the first HFN; If the second SN is less than a minimum value in the SN range, the HFN of the first PDCP PDU is equal to the first HFN plus 1; If the second SN is greater than a maximum value in the SN range, the HFN of the first PDCP PDU is equal to the first HFN minus 1.

10. A communication method, characterized in that: Applied to terminal equipment, including: receiving a PDCP PDU from a network device; receiving first indication information from the network device, The first indication information is used to indicate whether there is HFN information in the PDCP PDU, or is used to indicate whether there is COUNT information in the PDCP PDU; or, The first indication information is used to indicate a format type of the PDCP PDU, the format type includes a first type and / or a second type, the PDCP PDU corresponding to the first type includes HFN information or COUNT information, and the PDCP PDU corresponding to the second type does not include the HFN information or COUNT information; or, The first indication information is used to indicate whether there is HFN information or COUNT information before or after the first indication information in the PDCP PDU; or, The first indication information is used to indicate whether there is HFN information or COUNT information before or after the indication field of the PDCP PDU; The indication field includes at least one of the following information: SN, reserved bit R, PDU type, data, and integrity message authentication code MAC-I; The method further comprises: Second indication information is received from the network device, where the second indication information is used to indicate whether the network device supports format type conversion, or is used to indicate the format type supported by the network device, or is used to indicate whether the network device only supports the first type.

11. The method according to claim 10, characterized in that Also includes: Capability information is sent to the network device, where the capability information is used to indicate whether the terminal device supports format type conversion, or is used to indicate the format types supported by the terminal device, or is used to indicate whether the terminal device only supports the first type.

12. A communication method, characterized in that: Applied to network equipment, including: Send PDCP PDU to the terminal device; Sending first indication information to the terminal device, where the first indication information is used to indicate whether there is HFN information in the PDCP PDU, or to indicate whether there is COUNT information in the PDCP PDU; or, The first indication information is used to indicate the PDCP PDU format type, the format type includes a first type and / or a second type, the PDCP PDU corresponding to the first type includes HFN information or COUNT information, and the PDCP PDU corresponding to the second type does not include the HFN information or COUNT information; or, The first indication information is used to indicate whether there is HFN information or COUNT information before or after the first indication information in the PDCP PDU; or, The first indication information is used to indicate whether there is HFN information or COUNT information before or after the indication field of the PDCP PDU; The indication field includes at least one of the following information: SN, reserved bit R, PDU type, data, and integrity message authentication code MAC-I; The method further comprises: Sending second indication information to the terminal device, wherein the second indication information is used to indicate whether the network device supports format type conversion, or is used to indicate the format type supported by the network device, or is used to indicate whether the network device only supports the first type.

13. The method according to claim 12, characterized in that Also includes: Receive capability information sent by the terminal device, where the capability information is used to indicate whether the terminal device supports format type conversion, or is used to indicate the format types supported by the terminal device, or is used to indicate whether the terminal device only supports the first type.

14. A communication device, characterized in that: include: A transceiver unit, configured to receive first information from a network device, wherein the first information includes information of a COUNT range; The transceiver unit is further configured to receive a first PDCP PDU from the network device, wherein the first PDCP PDU includes a second SN; A processing unit for: If the second SN is greater than or equal to the SN corresponding to the minimum value in the COUNT range, determine that the HFN of the first PDCP PDU is equal to the HFN corresponding to the minimum value in the COUNT range; If the second SN is less than or equal to the SN corresponding to the maximum value in the COUNT range, it is determined that the HFN of the first PDCP PDU is equal to the HFN corresponding to the maximum value in the COUNT range.

15. A communication device, characterized in that: include: A transceiver unit, configured to receive first information from a network device, wherein the first information includes information of a first HFN and information of a first SN; The transceiver unit is further configured to receive a first PDCP PDU from the network device, wherein the first PDCP PDU includes a second SN; A processing unit for: If the second SN is less than the difference between the first SN and the first parameter, determining that the HFN of the first PDCP PDU is equal to the first HFN plus 1; If the second SN is greater than or equal to the sum of the first SN and a first parameter, determine that the HFN of the first PDCP PDU is equal to the first HFN minus 1; If the second SN is greater than or equal to a difference between the first SN and a first parameter, and / or the second SN is less than a sum of the first SN and the first parameter, it is determined that the HFN of the first PDCP PDU is equal to the first HFN.

16. A communication device, characterized in that: include: A transceiver unit, configured to receive first information from a network device, wherein the first information includes: information of a first HFN and information of an SN range; The transceiver unit is further configured to receive a first PDCP PDU from the network device, wherein the first PDCP PDU includes a second SN; A processing unit for: If the second SN is within the SN range, determining that the HFN of the first PDCP PDU is equal to the first HFN; If the second SN is less than a minimum value in the SN range, determining that the HFN of the first PDCP PDU is equal to the first HFN plus 1; If the second SN is greater than a maximum value in the SN range, it is determined that the HFN of the first PDCP PDU is equal to the first HFN minus 1.

17. The device according to any one of claims 14 to 16, characterized in that The processing unit is also used for: Set the first state variable according to one of the following methods: Setting the minimum value or the maximum value between the COUNT of the first received PDCP PDU and the COUNT corresponding to the first information as the first state variable; Setting the minimum value or the maximum value in the COUNT of the N received PDCP PDUs as the first state variable, where N is a positive integer; Set the minimum value or the maximum value between the COUNT of the N received PDCP PDUs and the COUNT corresponding to the first information as the first state variable, where N is a positive integer; Setting the minimum value or the maximum value in the COUNT of the PDCP PDUs received in the first time period T as the first state variable; The minimum value or the maximum value between the COUNT of the PDCP PDU received in the first time period T and the COUNT corresponding to the first information is set as the first state variable.

18. The device according to claim 17, characterized in that Any one or more of the first PDCP PDU, the first received PDCP PDU, the N received PDCP PDUs, the PDCP PDUs received within the first time period T, and the first information is associated with the first PDCP entity or the first radio bearer.

19. The device according to claim 18, characterized in that The first PDCP entity and / or the first radio bearer are associated with a first service, and the first service includes a broadcast service and / or a multicast service.

20. A communication device, characterized in that: include: A transceiver unit, configured to send first information to a terminal device, wherein the first information includes information of a COUNT range; The transceiver unit is further configured to send a first PDCP PDU to the terminal device, where the first PDCP PDU includes a second SN; If the second SN is greater than or equal to the SN corresponding to the minimum value in the COUNT range, the HFN of the first PDCP PDU is equal to the HFN corresponding to the minimum value in the COUNT range; If the second SN is less than or equal to the SN corresponding to the maximum value in the COUNT range, the HFN of the first PDCP PDU is equal to the HFN corresponding to the maximum value in the COUNT range.

21. A communication device, characterized in that: include: A transceiver unit, configured to send first information to a terminal device, wherein the first information includes information about a first HFN and information about a first SN; The transceiver unit is further configured to send a first PDCP PDU to the terminal device, where the first PDCP PDU includes a second SN; If the second SN is less than the difference between the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN plus 1; If the second SN is greater than or equal to the sum of the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN minus 1; If the second SN is greater than or equal to a difference between the first SN and a first parameter, and / or the second SN is less than a sum of the first SN and the first parameter, the HFN of the first PDCP PDU is equal to the first HFN.

22. A communication device, characterized in that: include: A transceiver unit, configured to send first information to a terminal device, wherein the first information includes information about a first HFN and information about an SN range; The transceiver unit is further configured to send a first PDCP PDU to the terminal device, where the first PDCP PDU includes a second SN; If the second SN is within the SN range, the HFN of the first PDCP PDU is equal to the first HFN; If the second SN is less than a minimum value in the SN range, the HFN of the first PDCP PDU is equal to the first HFN plus 1; If the second SN is greater than a maximum value in the SN range, the HFN of the first PDCP PDU is equal to the first HFN minus 1.

23. A communication device, characterized in that: include: A transceiver unit, configured to receive a PDCP PDU from a network device; The transceiver unit is further configured to receive first indication information from the network device, where the first indication information is used to indicate whether there is HFN information in the PDCP PDU, or to indicate whether there is COUNT information in the PDCP PDU; or, The first indication information is used to indicate the PDCP PDU format type, the format type includes a first type and / or a second type, the PDCP PDU corresponding to the first type includes HFN information or COUNT information, and the PDCP PDU corresponding to the second type does not include the HFN information or COUNT information; or, The first indication information is used to indicate whether there is HFN information or COUNT information before or after the first indication information in the PDCP PDU; or, The first indication information is used to indicate whether there is HFN information or COUNT information before or after the indication field of the PDCP PDU; The indication field includes at least one of the following information: SN, reserved bit R, PDU type, data, and integrity message authentication code MAC-I; The transceiver unit is also used to receive second indication information from the network device, wherein the second indication information is used to indicate whether the network device supports format type conversion, or to indicate the format type supported by the network device, or to indicate whether the network device only supports the first type.

24. The device according to claim 23, characterized in that Also includes: The transceiver unit is also used to send capability information to the network device, where the capability information is used to indicate whether the communication device supports format type conversion, or to indicate the format type supported by the communication device, or to indicate whether the communication device only supports the first type.

25. A communication device, characterized in that: include: A transceiver unit, used to send PDCP PDU to a terminal device; The transceiver unit is further used to send first indication information to the terminal device, where the first indication information is used to indicate whether there is information about the first HFN in the PDCP PDU, or to indicate whether there is information about the COUNT in the PDCP PDU; or, The first indication information is used to indicate the PDCP PDU format type, the format type includes a first type and / or a second type, the PDCP PDU corresponding to the first type includes HFN information or COUNT information, and the PDCP PDU corresponding to the second type does not include the HFN information or COUNT information; or, The first indication information is used to indicate whether there is HFN information or COUNT information before or after the first indication information in the PDCP PDU; or, The first indication information is used to indicate whether there is HFN information or COUNT information before or after the indication field of the PDCP PDU; The indication field includes at least one of the following information: SN, reserved bit R, PDU type, data, and integrity message authentication code MAC-I; The transceiver unit is also used to send second indication information to the terminal device, wherein the second indication information is used to indicate whether the communication device supports format type conversion, or to indicate the format type supported by the communication device, or to indicate whether the communication device only supports the first type.

26. The device according to claim 25, characterized in that Also includes: The transceiver unit is also used to receive capability information sent by the terminal device, wherein the capability information is used to indicate whether the terminal device supports format type conversion, or to indicate the format types supported by the terminal device, or to indicate whether the terminal device only supports the first type.

27. A communication device comprising at least one processor and a memory, wherein the memory stores instructions, characterized in that: When the instructions are executed on a computer, the computer is caused to execute the method according to any one of claims 1 to 6 or 10 to 11.

28. A communication device, comprising at least one processor and a memory, wherein the memory stores instructions, characterized in that: When the instructions are executed on a computer, the computer is caused to execute the method according to any one of claims 7 to 9 or 12 to 13.

29. A computer-readable storage medium for storing instructions, characterized in that: When the instructions are executed on a computer, the computer is caused to execute the method according to any one of claims 1 to 6 or 10 to 11.

30. A computer-readable storage medium for storing instructions, characterized in that: When the instructions are executed on a computer, the computer is caused to execute the method according to any one of claims 7 to 9 or 12 to 13.

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