WO2023207555A1

WO2023207555A1 - Communication method and apparatus

Info

Publication number: WO2023207555A1
Application number: PCT/CN2023/086982
Authority: WO
Inventors: 张海森; 李秉肇; 许斌
Original assignee: 华为技术有限公司
Priority date: 2022-04-24
Filing date: 2023-04-07
Publication date: 2023-11-02
Also published as: CN116980838A

Abstract

A communication method and apparatus. The method comprises: an access network device receives a first data packet from a core network device, and sends first indication information to the core network device, wherein the first data packet is a data packet of a first QoS flow of a multicast and broadcast service (MBS), and an MBS QFI SN of the first data packet is less than a first threshold; and after receiving the first indication information from the access network device, the core network device sets an MBS QFI SN of a second data packet of the first QoS flow according to the first indication information, wherein the second data packet is a data packet after the first data packet, the MBS QFI SN of the second data packet is greater than or equal to 0 and less than the MBS QFI SN of the first data packet. On the basis of the solution, when the MBS QFI SN of the data packet of the first QoS flow does not reach the first threshold, the core network device can reset the MBS QFI SN of the data packet of the first QoS flow, thereby effectively reducing overflow of a COUNT value in the access network device caused by too large MBS QFI SN, thus reducing packet loss caused by the overflow of the COUNT value.

Description

A communication method and device

This application claims priority to the Chinese patent application submitted to the State Intellectual Property Office on April 24, 2022, with application number 202210436049.6 and application title "A communication method and device", the entire content of which is incorporated into this application by reference. .

Technical field

The embodiments of the present application relate to the field of communication, and in particular, to a communication method and device.

Background technique

The data protocol data unit (PDU) of the packet data convergence protocol (PDCP) layer is identified by the COUNT value. As shown in Figure 1, the COUNT value consists of the high-order hyperframe number (HFN) and the low-order PDCP sequence number (SN). Usually, the PDCP PDU sent by the sender to the receiver includes the PDCP SN, and the receiver calculates the HFN based on the PDCP SN to determine the COUNT value of the PDCP PDU.

For a certain multicast and broadcast service (MBS), in order to enable different access network equipment to generate the same COUNT value for the same data packet of the service, the core network equipment is quality of service (QoS). Each data packet of the flow generates a QoS flow identifier (QFI) SN so that different access network devices can generate COUNT values based on the QFI SN.

Among them, the number of bits of QFI SN is the same as the number of bits of COUNT value. When the MRB and QoS flow have a one-to-one relationship, the access network device usually intercepts the high bits of the QFI SN as the HFN of the COUNT value, and the low bits as the PDCP SN of the COUNT value.

However, in order to avoid the situation where the initial HFN of the state variable RX_DELIV maintained by the receiving end is a negative value, the access network equipment usually takes certain measures. For example, when the access network generates a COUNT value, it will add a certain value to the HFN generated through the QFI SN as the HFN corresponding to the COUNT value. That is, for a certain data packet, the HFN corresponding to the COUNT value may be greater than the high value of QFI SN. It may happen that the COUNT value has reached the upper limit, but the QFI SN has not yet reached the upper limit. If the COUNT value reaches the upper limit (or overflow), it will cause packet loss, thus affecting the reliability of the service.

Contents of the invention

This application provides a communication method and device that can effectively reduce COUNT value overflow caused by excessive MBS QFI SN, thereby reducing packet loss caused by COUNT value overflow.

In the first aspect, a communication method is provided. The method can be executed by a core network device, or by a component of the core network device, such as a processor, a chip, or a chip system of the core network device. It can also be executed by a device capable of implementing Logic modules or software implementation of all or part of the core network equipment functions. The method includes: sending a first data packet to an access network device. Wherein, the first data packet is a data packet of the first QoS flow of the MBS service, and the MBS QFI SN of the first data packet is less than the first threshold. Receive first indication information from the access network device, and set the MBS QFI SN of the second data packet of the first QoS flow according to the first indication information. Among them, the MBS QFI SN of the second data packet is greater than or equal to 0 and less than the MBS QFI SN of the first data packet, and the second data packet is the data packet after the first data packet.

Based on the solution of this application, the access network device sends the first indication information to the core network device, so that the core network device can set the second data packet based on the first indication information when the MBS QFI SN of the first data packet is less than the first threshold. MBS The QFI SN is greater than or equal to 0 and less than the MBS QFI SN of the first data packet. That is to say, the core network device can reset the MBS QFI SN of the data packet of the first QoS flow when the MBS QFI SN of the data packet of the first QoS flow does not reach the first threshold, effectively reducing the problem caused by excessive MBS QFI SN. The COUNT value in the access network equipment overflows, thereby reducing packet loss caused by COUNT value overflow and improving service reliability.

In the second aspect, a communication method is provided. The method can be executed by the access network device, or by components of the access network device, such as the processor, chip, or chip system of the access network device. It can also be executed by It is implemented by logical modules or software that can realize all or part of the access network equipment functions. The method includes: receiving a first data packet from a core network device and sending first indication information to the core network device. Wherein, the first data packet is a data packet of the QoS flow of the MBS service, and the MBS QFI SN of the first data packet is less than the first threshold. The first indication information is used by the core network device to set the MBS QFI SN of the second data packet of the first QoS flow. The MBS QFI SN of the second data packet is greater than or equal to 0 and less than the MBS QFI SN of the first data packet. The data packet is the data packet after the first data packet. Among them, the technical effects brought by the second aspect can be referred to the technical effects brought by the above-mentioned first aspect, which will not be described again here.

In combination with the first aspect or the second aspect, in a possible design, the first indication information includes at least one of the following:

Information indicating that the maximum COUNT value of data packets of the first MBS radio bearer MRB is equal to the second threshold, where the first MRB is the MRB associated with the first QoS flow;

Information indicating that the difference between the maximum COUNT value of the data packet of the first MRB and the second threshold is less than or equal to M1, where M1 is a positive integer;

Information indicating a difference between the maximum COUNT value of the data packet of the first MRB and the second threshold;

Status information of the first MRB;

Information indicating that the maximum MBS QFI SN of the first QoS flow is equal to the third threshold;

Information indicating that the difference between the maximum MBS QFI SN of the first QoS flow and the third threshold is less than or equal to M2, where M2 is a positive integer; or,

Information indicating the difference between the maximum MBS QFI SN of the first QoS flow and the third threshold.

Based on this possible design, the first indication information includes information indicating that the difference between the maximum COUNT value of the data packet of the first MRB and the second threshold is less than or equal to M1, or includes information indicating the maximum MBS QFI SN of the first QoS flow When the difference between the third threshold and the information of M2 is less than or equal to M2, it means that the maximum COUNT value of the access network device in the first MRB is close to the second threshold, or the maximum MBS QFI SN of the first QoS flow is close to the third threshold. When , the first indication information is sent to the core network device, and a long time is reserved for the transmission of the first indication information, so that the core network device can receive the first indication information before the COUNT value overflows, and according to the first indication information Setting the MBS QFI SN of the second data packet effectively reduces the COUNT value overflow in the access network equipment caused by excessive MBS QFI SN, thereby reducing packet loss caused by COUNT value overflow and improving service reliability.

In conjunction with the first aspect or the second aspect, in a possible design, the first indication information further includes at least one of the following: an identifier of the first MRB, an identifier of the first QoS flow, or an identifier of the MBS service.

In combination with the first aspect or the second aspect, in a possible design, the second data packet is the data packet after the first data packet, including: the second data packet is the M3th data packet after the first data packet. M3 is less than or equal to M1+1, M1 is the maximum difference between the maximum COUNT value of the data packet of the first MRB and the second threshold, and the first MRB is the MRB associated with the first QoS flow. Or, M3 is less than or equal to M2+1, and M2 is the maximum difference between the maximum MBS QFI SN of the first QoS flow and the third threshold.

In the third aspect, a communication method is provided. The method can be executed by the core network equipment, or by components of the core network equipment, such as the processor, chip, or chip system of the core network equipment. It can also be implemented by Logic modules or software implementation of all or part of the core network equipment functions. The method includes: receiving second indication information from the access network device. Release the first MBS session of the multicast broadcast service MBS service according to the second instruction information, and establish the second MBS session of the MBS service. Alternatively, delete the first QoS flow of the first MBS session according to the second indication information, and add the second QoS flow to the first MBS session.

Based on this solution, the core network device can release the first MBS session of the MBS service based on the second instruction information of the access network device, and establish the second MBS session of the MBS service. Because when the first MBS session is released, the QoS flow of the first MBS session is deleted. After the second MBS session is created, the QoS flow in the second MBS session is also newly created. Therefore, the core network device subsequently passes the third MBS session. When the QoS stream in the second MBS session transmits the data packet of the MBS service, the MBS QFI SN of the data packet can start from 0, and the corresponding COUNT value of the data packet is smaller. Therefore, the access network device can send the second indication information according to the actual situation, for example, when the COUNT value is about to overflow, so that the MBS QFI SN of subsequent data packets is smaller, thereby reducing the problem of excessive MBS QFI SN in the access network device. COUNT value overflow, thereby reducing packet loss caused by COUNT value overflow and improving service reliability.

Alternatively, the core network device may delete the first QoS flow of the first MBS session based on the second indication information of the access network device, and add the second QoS flow to the first MBS session. Since the second QoS flow is newly added, when the core network equipment subsequently transmits the MBS service data packet through the second QoS flow, the MBS QFI SN of the data packet can start from 0, thereby reducing the MBS QFI SN from being too large. The resulting COUNT value overflows and improves business reliability.

In the fourth aspect, a communication method is provided. The method can be executed by the access network device, or by components of the access network device, such as the processor, chip, or chip system of the access network device. It can also be executed by the access network device. It is implemented by logical modules or software that can realize all or part of the access network equipment functions. The method includes: generating second indication information and sending the second indication information to the core network device. The second instruction information is used by the core network device to release the first MBS session of the multicast broadcast service MBS service and to establish the second MBS session of the MBS service. Alternatively, the second instruction information is used by the core network device to delete the first quality of service QoS flow of the first MBS session and add the second QoS flow to the first MBS session. Among them, the technical effects brought by the fourth aspect can be referred to the technical effects brought by the above-mentioned third aspect, which will not be described again here.

Combined with the third aspect or the fourth aspect, in a possible design, the second indication information includes at least one of the following:

Status information of the first MRB;

In the fifth aspect, a communication method is provided. The method can be executed by the access network device, or by components of the access network device, such as the processor, chip, or chip system of the access network device. It can also be executed by the access network device. It is implemented by logical modules or software that can realize all or part of the access network equipment functions. The method includes: generating third indication information and sending the third indication information to the core network device. Wherein, the third indication information indicates the maximum value and/or the minimum value of the multicast broadcast service MBS quality of service flow identification sequence number QFI SN.

Based on this solution, the access network device can send third indication information to the core network device to indicate the maximum value and/or minimum value of the MBS QFI SN, so that the maximum value and/or the minimum value of the MBS QFI SN can be flexibly changed. For example, the access network device can flexibly indicate the maximum value and/or the minimum value of the MBS QFI SN to the core network device according to actual needs. In access network equipment When the equipment needs to avoid COUNT value overflow, it can indicate to the core network equipment the maximum value of the MBS QFI SN used to limit the COUNT value overflow, thereby reducing the COUNT value overflow in the access network equipment caused by the MBS QFI SN being too large, thereby reducing the risk of COUNT value overflow. Packet loss caused by value overflow improves service reliability.

In addition, when the access network device indicates the minimum value of MBS QFI SN to the core network device, since the COUNT value of the data packet is equal to the MBS QFI SN of the data packet, and the maximum MBS QFI SN can only be 2 ^N -1, therefore, The maximum COUNT value of a data packet is also 2 ^N -1, which avoids overflow of the COUNT value and thus improves service reliability.

In one possible design, the maximum value is less than 2 ^N -1 and the minimum value is greater than 0, where N is the length of the MBS QFI SN.

The sixth aspect provides a communication method, which can be executed by the core network device, or can be executed by components of the core network device, such as the processor, chip, or chip system of the core network device, or can be implemented by Logic modules or software implementation of all or part of the core network equipment functions. The method includes: obtaining the maximum value and/or the minimum value of the MBS QFI SN. Among them, the maximum value is less than 2 ^N -1, the minimum value is greater than 0, and N is the length of MBS QFI SN. Send the first data packet, the MBS QFI SN of the first data packet is less than or equal to the maximum value, and/or is greater than or equal to the minimum value, and the first data packet is a data packet of the first QoS flow of the MBS service.

Based on this solution, the core network equipment can obtain the maximum value and/or the minimum value of the MBS QFI SN, and can also make the maximum value and/or the minimum value flexible. When it is necessary to avoid COUNT value overflow, the core network equipment can set the maximum value of MBS QFI SN that limits COUNT value overflow, thereby reducing COUNT value overflow caused by excessive MBS QFI SN. Alternatively, the core network equipment can set the minimum value of MBS QFI SN. At this time, since the COUNT value of the data packet is equal to the MBS QFI SN of the data packet, and the maximum MBS QFI SN can only be 2 ^N -1, therefore, the maximum value of the data packet The COUNT value is also 2 ^N -1, which avoids the overflow of the COUNT value in the access network equipment, thus improving the reliability of the service.

The seventh aspect provides a communication method, which can be executed by the core network equipment, or can be executed by components of the core network equipment, such as the processor, chip, or chip system of the core network equipment, or can be implemented by Logic modules or software implementation of all or part of the core network equipment functions. The method includes: obtaining the maximum value and/or the minimum value of the MBS QFI SN. Among them, the maximum value is less than 2 ^N -1, the minimum value is greater than 0, and N is the length of MBS QFI SN. A first data packet and a second data packet are sent. The first data packet is a data packet of the first quality of service QoS flow of the MBS service, and the second data packet is a data packet of the second QoS flow of the MBS service. Wherein, the sum of the MBS QFI SN of the first data packet and the MBS QFI SN of the second data packet is less than or equal to the maximum value; and/or, the sum of the MBS QFI SN of the first data packet and the MBS QFI SN of the second data packet Greater than or equal to the minimum value, the first QoS flow and the second QoS flow are associated with one MRB. Among them, the technical effects brought by the seventh aspect can be referred to the technical effects brought by the above-mentioned sixth aspect, which will not be described again here.

In one possible design, obtaining the maximum value and/or the minimum value of the MBS QFI SN includes: receiving third indication information from the access network device; obtaining the maximum value of the MBS QFI SN according to the third indication information, and/or, min.

Combined with the fifth aspect, the sixth aspect, or the seventh aspect, in a possible design, the maximum value of the MBS QFI SN is based on the length N of the MBS QFI SN, the length of the packet data convergence protocol sequence number PDCP SN, or the offset At least one of the values is determined. Alternatively, the minimum value of the MBS QFI SN is determined based on at least one of the length N of the MBS QFI SN, the length of the PDCP SN, or the offset value. Among them, the offset value is used to determine the superframe number HFN of the COUNT value of the data packet.

Combining the fifth, sixth or seventh aspect, in a possible design, the maximum value of MBS QFI SN satisfies the following formula:
MBS QFI SN _max =2 ^N -Y

Among them, MBS QFI SN _max represents the maximum value of MBS QFI SN, and Y is an integer greater than 1.

Combining the fifth, sixth or seventh aspect, in a possible design, Y satisfies the following formula:
Y≥X*2 ^{[PDCP-SN-Size]} +Q ₁

Among them, X represents the offset value, * represents the multiplication operation, PDCP-SN-Size represents the length of the PDCP SN, and Q ₁ is the maximum An integer equal to or equal to 1.

Combined with the fifth, sixth or seventh aspect, in a possible design, the minimum value of MBS QFI SN and the length of PDCP SN satisfy one of the following formulas:

MBS QFI SN _min =2 ^{[PDCP-SN-Size]} ;
MBS QFI SN _min =X*2 ^{[PDCP-SN-Size]} +Q ₂ ; or,
MBS QFI SN _min =0.5*2 ^{[PDCP-SN-Size]-1}

Among them, MBS QFI SN _min represents the minimum value of MBS QFI SN, PDCP-SN-Size represents the length of PDCP SN, X represents the offset value, * represents multiplication operation, and Q ₂ is an integer greater than or equal to 0.

In combination with the fifth aspect, the sixth aspect, or the seventh aspect, in a possible design, when the third indication information indicates the maximum value of the MBS QFI SN, the HFN of the COUNT value of the data packet is equal to the K of the MBS QFI SN of the data packet. The sum of the value of the high-order bits and the offset value, K is the length of HFN.

Based on this possible design, the HFN of the COUNT value of the first data packet is equal to the sum of the value of the K high-order bits of the MBS QFI SN of the first data packet and the offset value, so that the initial value of HFN of RX_DELIV will not be a negative value. . Moreover, the maximum MBS QFI SN of the first data packet is the above-mentioned maximum value, and this maximum value can ensure that the COUNT value of the first data packet will not overflow. Therefore, in this method, the MBS QFI SN of the first data packet will not cause the initial value of HFN of RX_DELIV to be a negative value, and the COUNT value of the first data packet will not overflow.

Combined with the fifth aspect, the sixth aspect, or the seventh aspect, in a possible design, when the third indication information indicates the minimum value of the MBS QFI SN, the COUNT value of the data packet is equal to the MBS QFI SN of the data packet.

Based on this possible design, the COUNT value of the first data packet is equal to the MBS QFI SN of the first data packet, and the maximum MBS QFI SN of the first data packet is 2 ^N -1, so that the maximum COUNT value of the first data packet is 2 ^N -1, avoids the overflow of the COUNT value of the first data packet. Therefore, in this method, the MBS QFI SN of the first data packet will not cause the initial value of HFN of RX_DELIV to be a negative value, and the COUNT value of the first data packet will not overflow.

In combination with the fifth aspect, the sixth aspect, or the seventh aspect, in a possible design, when the third indication information indicates the maximum value and minimum value of the MBS QFI SN, the HFN of the COUNT value of the data packet is equal to the MBS QFI of the data packet. The sum of the value of the K high-order bits of SN and the offset value, K is the length of HFN; alternatively, the COUNT value of the data packet is equal to the MBS QFI SN of the data packet.

Based on this possible design, the MBS QFI SN of the first data packet will not make the initial value of HFN of RX_DELIV a negative value, and the COUNT value of the first data packet will not overflow.

In an eighth aspect, a communication method is provided. The method can be executed by the access network device, or can be executed by a component of the access network device, such as a processor, chip, or chip system of the access network device. It can also be executed by It is implemented by logical modules or software that can realize all or part of the access network equipment functions. The method includes: receiving a first data packet from a core network device, and when the MBS QFI SN of the first data packet meets a first condition, releasing a first MRB associated with the first QoS flow, and establishing a second MRB associated with the first QoS flow. MRB, the first data packet is carried in the first MRB. The first data packet is a data packet of the first QoS flow of the MBS.

Based on this solution, when the MBS QFI SN of the received data packet meets the first condition, the access network device releases the first MRB carrying the data packet and creates a second MRB. That is to say, in the process of increasing the MBS QFI SN of the first QoS flow from 0 to 2 ^N -1, the access network device can perform the release and creation of the MRB at least once. After a new MRB is created, the COUNT value of the MRB's data packets can start from the minimum value that can be obtained. Therefore, in the process of the MBS QFI SN of the first QoS flow increasing from 0 to 2 ^N -1, the COUNT value can be flipped at least once, thereby reducing the risk of COUNT value overflow.

In one possible design, the first condition is related to the first value. Among them, the first value is based on MBS QFI SN The length of the packet data convergence protocol sequence number PDCP SN is determined; or the first value is a preset value.

In a possible design, the first condition includes: the MBS QFI SN of the first data packet is greater than 0 and is evenly divided by the first value; or, the MBS QFI SN of the first data packet plus 1 is evenly divided by the first value; or, the first The MBS QFI SN of the data packet is equal to the first value.

In a possible design, the first value satisfies one of the following formulas:
S ₁ = ^2NM
S ₁ =2 ^NM -1;
S ₁ =2 ^PDCP-SN-Size -1;
S ₁ ≥0.5*2 ^{[PDCP-SN-Size]-1} -1; or,
S ₁ ＝2 ^N -X*2 ^PDCP-SN-Size -1

Among them, S ₁ represents the first numerical value, N represents the length of the MBS QFI SN, M is a positive integer, PDCP-SN-Size represents the length of the PDCP SN, * represents the multiplication operation, X represents the offset value, and the offset value is used to determine The superframe number HFN of the packet's COUNT value.

In one possible design, 2 ^N data packets of the first QoS flow are carried on 2 ^M MRBs. Among the 2 ^N data packets, the MBS QFI SN of the starting data packet is 0, and the MBS QFI SN of the terminating data packet is 0. QFI SN is 2 ^N-1 .

In a possible design, the method further includes: receiving a second data packet from the core network device, and when the MBS QFI SN of the second data packet is equal to 2 ^N -1, releasing the third MRB associated with the first QoS, and A fourth MRB associated with the first QoS flow is established, the second data packet is carried in the third MRB, and the second data packet is a data packet of the first QoS flow.

In a ninth aspect, a communication system is provided, which includes access network equipment and core network equipment. The core network device sends the first data packet to the access network device, and correspondingly, the access network device receives the first data packet from the core network device. Wherein, the first data packet is a data packet of the first QoS flow of the MBS service, and the MBS QFI SN of the first data packet is less than the first threshold.

The access network device sends the first indication information to the core network device. Correspondingly, the core network device receives the first indication information from the access network device and sets the MBS of the second data packet of the first QoS flow according to the first indication information. QFI SN, the MBS QFI SN of the second data packet is greater than or equal to 0 and less than the MBS QFI SN of the first data packet, and the second data packet is the data packet after the first data packet.

In a tenth aspect, a communication system is provided, which includes access network equipment and core network equipment. The access network device generates second indication information and sends the second indication information to the core network device. Correspondingly, the core network device receives the second instruction information from the access network device, releases the first MBS session of the MBS service according to the second instruction information, and establishes the second MBS session of the MBS service; or deletes it according to the second instruction information. the first QoS flow of the first MBS session and adds the second QoS flow in the first MBS session.

In an eleventh aspect, a communication system is provided, which includes access network equipment and core network equipment. Wherein, the access network device generates third indication information and sends the third indication information to the core network device. Correspondingly, the core network device receives the third indication information from the access network device, and obtains the maximum value and/or the minimum value of the MBS QFI SN according to the third indication information. The core network device sends the first data packet, and the MBS QFI SN of the first data packet is less than or equal to the maximum value, and/or is greater than or equal to the minimum value. The first data packet is a data packet of the first QoS flow of the MBS service.

In a twelfth aspect, a communication system is provided, which includes access network equipment and core network equipment. Wherein, the access network device generates third indication information and sends the third indication information to the core network device. Correspondingly, the core network device receives the third indication information from the access network device, and obtains the maximum value and/or the minimum value of the MBS QFI SN according to the third indication information. The core network device sends the first data packet and the second data packet. The first data packet is the first QoS of the MBS service. The second data packet is the data packet of the second QoS flow of the MBS service. The first QoS flow and the second QoS flow are associated with one MRB. The sum of the MBS QFI SN of the first data packet and the MBS QFI SN of the second data packet is less than or equal to the maximum value; and/or the sum of the MBS QFI SN of the first data packet and the MBS QFI SN of the second data packet is greater than or equal to the minimum value.

In a thirteenth aspect, a communication device is provided for implementing various methods. The communication device may be the core network equipment in the first aspect, the third aspect, the sixth aspect, or the seventh aspect, or a device included in the core network equipment, such as a chip; or, the communication device may be the second aspect or The access network equipment in the fourth aspect, the fifth aspect, or the eighth aspect, or the device included in the access network equipment, such as a chip. The communication device includes modules, units, or means (means) corresponding to the implementation method. The modules, units, or means can be implemented by hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to functions.

In some possible designs, the communication device may include a processing module and a transceiver module. This processing module can be used to implement the processing functions in any of the above aspects and any possible implementation manner thereof. The transceiver module, which may also be called a transceiver unit, is used to implement the sending and/or receiving functions in any of the above aspects and any possible implementation manner thereof. The transceiver module can be composed of a transceiver circuit, a transceiver, a transceiver or a communication interface.

In some possible designs, the transceiver module includes a sending module and/or a receiving module, respectively used to implement the sending or receiving function in any of the above aspects and any possible implementation thereof.

A fourteenth aspect, a communication device is provided, including: a processor and a communication interface; the communication interface is used to communicate with a module outside the communication device; the processor is used to execute a computer program or instructions to enable the communication The apparatus performs the method described in any aspect. The communication device may be the core network equipment in the first aspect, the third aspect, the sixth aspect, or the seventh aspect, or a device included in the core network equipment, such as a chip; or, the communication device may be the second aspect or The access network equipment in the fourth aspect, the fifth aspect, or the eighth aspect, or the device included in the access network equipment, such as a chip.

In a fifteenth aspect, a communication device is provided, including: at least one processor; the processor is configured to execute a computer program or instructions stored in a memory, so that the communication device executes the method described in any aspect. The memory may be coupled to the processor, or the memory may exist independently of the processor. For example, the memory and the processor may be two independent modules. The memory may be located outside the communication device or within the communication device. The communication device may be the core network equipment in the first aspect, the third aspect, the sixth aspect, or the seventh aspect, or a device included in the core network device, such as a chip or a chip system. When the device is a chip system, it may be The chip structure may also include chips and other discrete components; or, the communication device may be the access network equipment in the second aspect, the fourth aspect, the fifth aspect, or the eighth aspect, or the access network equipment included in the access network equipment. A device, such as a chip or a system-on-a-chip. When the device is a system-on-a-chip, it may be composed of a chip or may include a chip and other discrete components.

In a sixteenth aspect, a computer-readable storage medium is provided. Computer programs or instructions are stored in the computer-readable storage medium. When run on a communication device, the communication device can perform the method described in any aspect. .

A seventeenth aspect provides a computer program product containing instructions that, when run on a communication device, enable the communication device to perform the method described in any aspect.

It can be understood that when the communication device provided in any one of the thirteenth to seventeenth aspects is a chip, the sending action/function can be understood as outputting information, and the receiving action/function can be understood as inputting information.

Among them, the technical effects brought by any one of the design methods in the thirteenth to seventeenth aspects can be found in the technical effects brought by the different design methods in the first to eighth aspects, and will not be described again here.

Description of the drawings

Figure 1 is a schematic structural diagram of a COUNT provided by this application;

Figure 2 is a schematic structural diagram of a communication system provided by this application;

Figure 3 is a schematic structural diagram of a communication device provided by this application;

Figure 4 is a schematic diagram of the transmission path of an MBS service provided by this application;

Figure 5 is a schematic structural diagram of a user plane protocol stack provided by this application;

Figure 6 is a schematic structural diagram of a PDCP PDU provided by this application;

Figure 7 is a calculation example diagram of RX_DELIV provided by this application;

Figure 8 is a schematic diagram for determining the COUNT value based on MBS QFI SN provided by this application;

Figure 9 is a schematic flow chart of a communication method provided by this application;

Figure 10 is a schematic flow chart of another communication method provided by this application;

Figure 11 is a schematic flow chart of another communication method provided by this application;

Figure 12 is a schematic flow chart of yet another communication method provided by this application;

Figure 13a is a schematic diagram of the release and new location of an MRB provided by this application;

Figure 13b is a schematic diagram 2 of the release and new location of an MRB provided by this application;

Figure 13c is a schematic diagram 3 of the release and new location of an MRB provided by this application;

Figure 13d is a schematic diagram 4 of the release and new location of an MRB provided by this application;

Figure 14 is a schematic diagram 5 of the release and new location of an MRB provided by this application;

Figure 15a is a schematic diagram 6 of the release and new location of an MRB provided by this application;

Figure 15b is a schematic diagram 7 of the release and new location of an MRB provided by this application;

Figure 16a is a schematic diagram 8 of the release and new location of an MRB provided by this application;

Figure 16b is a schematic diagram 9 of the release and new location of an MRB provided by this application;

Figure 17a is a schematic diagram 10 of the release and new location of an MRB provided by this application;

Figure 17b is a schematic diagram 11 of the release and new location of an MRB provided by this application;

Figure 18 is a schematic structural diagram of an access network device provided by this application;

Figure 19 is a schematic structural diagram of a core network device provided by this application.

Detailed ways

In the description of this application, unless otherwise stated, "/" means that the related objects are in an "or" relationship. For example, A/B can mean A or B; "and/or" in this application only means It is an association relationship that describes associated objects. It means that there can be three relationships. For example, A and/or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. Among them, A and B Can be singular or plural.

In the description of this application, unless otherwise stated, "plurality" means two or more than two. "At least one of the following" or similar expressions thereof refers to any combination of these items, including any combination of a single item (items) or a plurality of items (items). For example, at least one of a, b, or c can mean: a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, c can be single or multiple .

In addition, in order to facilitate a clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as “first” and “second” are used to distinguish identical or similar items with basically the same functions and effects. Those skilled in the art can understand that words such as "first" and "second" do not limit the number and execution order, and words such as "first" and "second" do not limit the number and execution order.

In the embodiments of this application, words such as "exemplary" or "for example" are used to represent examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "such as" in the embodiments of the present application is not to be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete manner that is easier to understand.

It will be understood that reference throughout this specification to "an embodiment" means that a particular feature, structure, or characteristic associated with the embodiment is included in at least one embodiment of the present application. Therefore, various embodiments are not necessarily referred to the same embodiment throughout this specification. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments. It can be understood that in the various embodiments of the present application, the size of the sequence numbers of each process does not mean the order of execution. The execution order of each process should be determined by its functions and internal logic, and should not be determined by the execution order of the embodiments of the present application. The implementation process constitutes no limitation.

It can be understood that some optional features in the embodiments of the present application, in certain scenarios, can be implemented independently without relying on other features, such as the solutions they are currently based on, to solve corresponding technical problems and achieve corresponding effects. , and can also be combined with other features according to needs in certain scenarios. Correspondingly, the devices provided in the embodiments of the present application can also implement these features or functions, which will not be described again here.

In this application, unless otherwise specified, the same or similar parts between various embodiments may be referred to each other. In the various embodiments of this application, if there are no special instructions or logical conflicts, the terms and/or descriptions between different embodiments are consistent and can be referenced to each other. Different embodiments can be combined to form new ones according to their inherent logical relationships. Embodiments. The embodiments of the present application described below do not constitute a limitation on the protection scope of the present application.

The technical solution provided by this application can be used in various communication systems. The communication system can be a third generation partnership project (3GPP) communication system, for example, the fourth generation (4th generation, 4G) long-term evolution (long term evolution, LTE) system, fifth generation (5th generation, 5G) new radio (NR) system, vehicle to everything (V2X) system, LTE and NR hybrid networking system, or device-to-device (device-to-device, D2D) system, machine to machine (machine to machine, M2M) communication system, Internet of Things (IoT), and other next-generation communication systems, etc. Alternatively, the communication system may also be a non-3GPP communication system, without limitation.

Among them, the above-mentioned communication systems applicable to the present application are only examples. The communication systems applicable to the present application are not limited to these and will be explained uniformly here, and will not be described in detail below.

Referring to Figure 2, an exemplary communication system is provided in this application. The communication system includes a core network device 201 and at least one access network device 202. Further, at least one terminal device 203 may also be included.

Optionally, when the communication system includes multiple access network devices 202, each of the multiple access network devices 202 can receive MBS service data packets through the core network device 203.

Optionally, the core network device 201 is mainly used for packet routing and forwarding of data packets, data packet inspection, implementation of some policy rules on the user plane, QoS processing on the user plane, etc. For example, in the 5G communication system, the core network device 201 may be a user plane function (UPF) network element or a multicast/broadcast user plane function (MB-UPF) network. Yuan.

Optionally, the access network device 202 is a device that connects terminal devices to a wireless network, and may be an evolutionary base station (evolutional Node B) in LTE or an evolved LTE system (LTE-Advanced, LTE-A). eNB or eNodeB), such as traditional macro base station eNB and micro base station eNB in heterogeneous network scenarios; or it can be the next generation node B (next generation node B, gNodeB or gNB) in the 5G system; or it can be a transmission receiving point (transmission reception point, TRP); or it can be a base station in the future evolved public land mobile network (public land mobile network, PLMN); or it can be a broadband network service gateway (broadband network gateway, BNG), aggregation switch or non-3GPP Access device; or it can be a wireless controller in a cloud radio access network (CRAN); or it can be an access point (AP) in a WiFi system; or it can be a wireless relay node Or a wireless backhaul node; or it can be a device that implements the base station function in IoT, a device that implements the base station function in V2X, a device that implements the base station function in D2D, or a device that implements the base station function in M2M. This is not specified in the embodiments of this application. limited.

For example, the base stations in the embodiments of the present application may include various forms of base stations, such as macro base stations, micro base stations (also called small stations), relay stations, access points, etc., which are not specifically limited in the embodiments of the present application. .

Optionally, during specific implementation, the access network device 202 may refer to a centralized unit (central unit, CU), or the access network device may be composed of a CU and a distributed unit (DU). CU and DU can be divided according to the protocol layer of the wireless network. For example, the functions of the radio resource control (RRC) protocol layer, service data adaptation protocol (SDAP) layer and packet data convergence protocol (PDCP) layer are set in the CU. The functions of the radio link control (RLC) layer, media access control (MAC) layer, and physical (physical, PHY) layer are set in the DU.

It can be understood that the division of CU and DU processing functions according to this protocol layer is only an example, and can also be divided in other ways, which is not specifically limited in this application.

In some embodiments, a CU may be composed of a CU control plane (CU control plane, CU-CP) and a CU user plane (CU user plane, CU-UP).

Optionally, the terminal device 203 may refer to a device with a wireless transceiver function. Terminal equipment can also be called user equipment (UE), terminal, access terminal, user unit, user station, mobile station (MS), remote station, remote terminal, mobile terminal (MT) , user terminal, wireless communication equipment, user agent or user device, etc. The terminal may be, for example, a wireless terminal in an IoT, V2X, D2D, M2M, 5G network, or a future evolved PLMN. The terminal device 203 can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it can also be deployed on water (such as ships, etc.); it can also be deployed in the air (such as aircraft, balloons, satellites, etc.).

Exemplarily, the terminal device 203 may be a drone, an IoT device (for example, a sensor, an electric meter, a water meter, etc.), a V2X device, a station (ST) in a wireless local area network (WLAN), or a cellular phone. , cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistant (PDA) devices, handheld devices with wireless communication capabilities, computing Equipment or other processing equipment connected to a wireless modem, vehicle-mounted equipment, wearable devices (also known as wearable smart devices), tablets or computers with wireless transceiver functions, virtual reality (VR) terminals, industrial controls Wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical, wireless terminals in smart grid, and transportation safety Wireless terminals, wireless terminals in smart cities, wireless terminals in smart homes, vehicle-mounted terminals, vehicles with vehicle-to-vehicle (V2V) communication capabilities, intelligent network connections Vehicles, drones with UAV to UAV (U2U) communication capabilities, etc. The terminal may be mobile or fixed, which is not specifically limited in this application.

Optionally, during specific implementation, the terminal equipment, access network equipment, or core network equipment shown in Figure 2 can adopt the composition structure shown in Figure 3, or include the components shown in Figure 3. Figure 3 is a schematic diagram of the composition of a communication device 300 provided by this application. The communication device 300 can be a terminal device or a chip or a system on a chip in the terminal device; or it can be an access network device or a module in the access network device. Or a chip or a system on a chip; or, it can be a core network device or a module or a chip or a system on a chip in the core network device.

As shown in FIG. 3 , the communication device 300 includes at least one processor 301 and at least one communication interface (FIG. 3 is only an example of including a communication interface 304 and a processor 301 for illustration). Optionally, the communication device 300 may also include a communication bus 302 and a memory 303.

The processor 301 may be a general central processing unit (CPU), general processor, network processor (NP), digital signal processing (DSP), microprocessor processor, microcontroller, programmable logic device (PLD) or any combination thereof. The processor 301 can also be other devices with processing functions, such as circuits, devices or software modules, without limitation.

The communication bus 302 is used to connect different components in the communication device 300 so that different components can communicate. The communication bus 302 may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of presentation, only one thick line is used in Figure 3, but it does not mean that there is only one bus or one type of bus.

Communication interface 304 is used to communicate with other devices or communication networks. For example, the communication interface 304 may be a module, a circuit, a transceiver, or any device capable of realizing communication. Optionally, the communication interface 304 may also be an input and output interface located within the processor 301 to implement signal input and signal output of the processor.

Memory 303 may be a device with a storage function, used to store instructions and/or data. Wherein, the instructions may be computer programs.

Exemplarily, the memory 303 may be a read-only memory (ROM) or other types of static storage devices that can store static information and/or instructions, or may be a random access memory (RAM). or other types of dynamic storage devices that can store information and/or instructions, and can also be electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory, CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, etc., are not restricted.

It should be noted that the memory 303 may exist independently of the processor 301 or may be integrated with the processor 301 . The memory 303 may be located inside the communication device 300 or outside the communication device 300, without limitation. The processor 301 can be used to execute instructions stored in the memory 303 to implement the methods provided by the following embodiments of the application.

As an optional implementation manner, the communication device 300 may also include an output device 305 and an input device 306. Output device 305 communicates with processor 301 and can display information in a variety of ways. For example, the output device 305 may be a liquid crystal display (LCD), a light emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector (projector), etc. Input device 306 communicates with processor 301 and can receive user input in a variety of ways. For example, the input device 306 may be a mouse, a keyboard, a touch screen device, a sensing device, or the like.

It should be noted that the structure shown in Figure 3 does not constitute a specific limitation on access network equipment, core network equipment, or terminal equipment. For example, in other embodiments of the present application, access network equipment, core network equipment, or terminal equipment may include more or less components than shown in the figures, or some components may be combined, or some components may be separated, or Different component arrangements. The components illustrated may be implemented in hardware, software, or a combination of software and hardware.

In order to facilitate understanding of the technical solutions of the embodiments of the present application, a brief introduction to the relevant technologies of the present application is first provided as follows.

1. Broadcast and multicast service (multicast and broadcast service, MBS):

MBS is a service for multiple terminal devices. Common MBS include live broadcast services, public safety services, batch software update services, etc. As shown in Figure 4, the transmission path of MBS can be: data server (or MBS server) → core network equipment → access network equipment → multiple terminal devices.

When the core network device sends the MBS service to the access network device, the service data is transmitted through an MBS session, and the MBS session includes at least one MBS quality of service (QoS) flow. When the access network device sends the MBS service to the terminal device, the service data is transmitted through the MBS radio bear (MBS radio bear, MRB). One MRB can be associated with one or more QoS flows. For an MRB, point-to-multipoint (PTM) or point-to-point (PTP) transmission can be used.

2. Wireless access network side protocol stack:

The protocol stack on the wireless access network side can be divided into a user plane protocol stack and a control plane protocol stack. The user plane protocol stack can include a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a media interface layer. Access control (media access control, MAC) layer and physical (physical, PHY) layer, etc. Among them, the physical layer belongs to the first layer (also called layer 1 (L1)), and the MAC layer, RLC layer, PDCP layer, and SDAP layer belong to the second layer (also called layer 2 (L2) ). In addition, the radio resource control (RRC) layer of the control plane belongs to the third layer (also called layer 3 (L3)).

As shown in Figure 5, in the user plane protocol stack of MBS, the SDAP layer is located above the PDCP layer, the PDCP layer is located above the RLC layer, the RLC layer is located above the MAC layer, and the MAC layer is located above the physical layer. For the MBS service, after the data reaches the access network device, each protocol layer processes the data packets in sequence from top to bottom as shown in Figure 5, and finally transmits them to the terminal device through the air interface. After receiving the data packet at the air interface, the terminal device processes the data packet accordingly in the reverse order of the access network device. Among them, the processing of data packets by each protocol layer is implemented by the multi-functional entity corresponding to the protocol layer. For example, the processing of the PDCP layer is implemented by the corresponding PDCP layer entity.

Generally, the service provided by Layer 2 to transmit user data between terminal equipment and access network equipment can be called a radio bearer (RB). For MBS services, the service provided by Layer 2 to transmit user data between terminal equipment and access network equipment can be called MRB. For example, the service of transmitting user data between the terminal device and the access network device can be implemented by each protocol layer belonging to layer 2 mentioned above.

It should be noted that the user plane protocol stack shown in Figure 5 does not constitute any limitation on the solution of this application. In actual applications, the user plane protocol stack may include more or fewer protocol layers than shown.

3. PDCP layer:

The PDCP layer is mainly used to process RRC messages on the control plane and Internet Protocol (IP) packets on the user plane. Mainly implements the following functions:

a) Security functions, such as data encryption/decryption, integrity protection/verification;

b)Compression/decompression of IP header;

c) Discard timed-out user plane data packets;

d) Reordering and retransmission of user plane data packets, etc.

The protocol data unit (packet data unit, PDU) of the PDCP layer is composed of the service data unit (SDU) of the PDCP layer and the PDCP header. In addition, the PDU at the PDCP layer is divided into data PDU (Data PDU) and control PDU (Control PDU). Data PDU can include user plane data and control plane data; control PDU can include PDCP status report and robust header compression (ROHC) feedback.

Among them, PDCP Data PDU (or SDU) is identified by the COUNT value, which consists of the high-order super frame number (HFN) and the low-order PDCP sequence number (SN). Usually, the PDCP PDU sent by the sender to the receiver includes PDCP SN. The receiving side can calculate the HFN based on the PDCP SN to determine the COUNT value of the PDCP PDU. The length of the COUNT value is usually 32 bits. The length of PDCP SN is 12 bits or 18 bits. The length of the HFN is 32-PDCP SN size.

Exemplarily, as shown in Figure 6, taking the size of the PDCP SN as 12 bits as an example, a PDCP PDU format is shown. Among them, the R field represents a reserved field and can be set to 0. The PDCP SN field is used to carry PDCP SN, cont. means continue, and the data field is used to carry data with variable length. The message authentication code for integrity (MAC-I) field is used to carry the digital signature generated by integrity protection.

Among them, the COUNT value is generated by the access network device. When there are multiple MRBs, the access network equipment can be Each MRB in the MRB maintains a COUNT value separately. For example, assuming that the length of the COUNT value is equal to 32 bits, when there are two MRBs, the COUNT value of the data packet of MRB#1 can range from 0 to 2 ³² -1, and the COUNT value of the data packet of MRB#2 has the same range. It is 0~2 ³² -1.

It should be noted that the “COUNT value” in this application can also be called (or described as) “COUNT”, and the two can be replaced with each other.

In the PDCP layer data transmission on the user plane, the sending PDCP entity maintains the state variable TX_NEXT. This state variable indicates the COUNT value of the next transmitted PDCP SDU. The initial value is 0.

The receiving PDCP entity maintains the following state variables:

RX_NEXT: This status variable indicates the COUNT value of the next PDCP SDU expected to be received. The initial value is 0.

RX_DELIV: This status variable indicates the COUNT value of the first (first) PDCP SDU that has not been submitted to the upper layer but is waiting to be submitted. The initial value is 0.

RX_RECORD: This status variable indicates that the COUNT value of the PDCP Data PDU that triggers the reordering (t-reordering) timer (timer) is increased by 1.

After receiving the PDCP PDU, the receiving PDCP entity first determines the HFN and COUNT values of the PDCP PDU based on the PDCP SN in the PDCP PDU header and the current state variable. Subsequent decryption and integrity verification can be performed based on the COUNT value, and the status variable can be updated.

For example, the receiving PDCP entity can determine the HFN of the PDCP PDU according to the following method:

If RCVD_SN<SN(RX_DELIV)-Window_Size:
RCVD_HFN=HFN(RX_DELIV)+1.

Otherwise, if RCVD_SN>=SN(RX_DELIV)+Window_Size:
RCVD_HFN=HFN(RX_DELIV)-1.

Otherwise (that is, RCVD_SN is greater than or equal to SN(RX_DELIV)-Window_Size, and less than SN(RX_DELIV)+Window_Size):
RCVD_HFN=HFN(RX_DELIV);
RCVD_COUNT=[RCVD_HFN, RCVD_SN].

Among them, RCVD_COUNT represents the COUNT value, RCVD_HFN in [RCVD_HFN, RCVD_SN] represents the HFN of the COUNT value, and RCVD_SN represents the PDCP SN of the COUNT value.

That is, the COUNT value in this application can be expressed in the form of [HFN, PDCP SN]. For example, [X ₁ , X ₂ ] indicates that the HFN of the COUNT value is equal to X ₁ and the PDCP SN is equal to X ₂ .

Among the above parameters:

HFN (state variable): represents the HFN part of the state variable;

SN (state variable): represents the SN part of the state variable;

RCVD_SN: Indicates the PDCP SN of the received PDCP Data PDU, included in the PDU header;

RCVD_HFN: Indicates the HFN of the received PDCP Data PDU calculated by the receiving PDCP entity;

RCVD_COUNT: Indicates the COUNT of the received PDCP Data PDU = [RCVD_HFN, RCVD_SN];

Window_Size: Indicates the (reordering) window size, its value is 2 ^{PDCP-SN-Size-1} ;

RX_DELIV is a status variable. SN(RX_DELIV) represents the SN part of RX_DELIV, and HFN(RX_DELIV) represents the HFN part of RX_DELIV.

In the unicast service, when the terminal device and the access network device start communicating, HFN=0, and the subsequent receiver calculates the HFN and COUNT values of the received PDCP PDU according to the above algorithm. Since in unicast services, when the access network device starts sending data to the terminal device, the terminal device starts to receive data. Therefore, the HFN of the terminal device and the access network device is always the same. Qi.

However, in the MBS service, the following situation may occur: after a certain access network device sends the MBS service for a period of time, a terminal device accesses the access network device to receive the MBS service. At this time, the HFN on the access network device side may not be 0. If the terminal equipment still follows the unicast technology and sets the initial value of HFN to 0, it will cause the HFN of the access network equipment and the terminal equipment to be misaligned, or the HFN will be out of sync (or out of synchronization).

In order to solve the problem of HFN out-of-synchronization between access network equipment and terminal equipment in MBS services, the following solutions are currently proposed:

The access network device sends the reference HFN and PDCP SN to the terminal device so that the terminal device can calculate the HFN of the first MBS data packet received by the terminal device, thereby aligning the HFN between the access network device and the terminal device;

For MRB, the initial value of PDCP SN of RX_NEXT is set to (x+1)mod2 ^PDCP-SN-Size ;

For MRB, the initial value of PDCP SN of RX_DELIV is set to (x-0.5*2 ^{[PDCP-SN-Size]-1} ) mod 2 ^PDCP-SN-Size .

Among them, x represents the value of PDCP SN of the first PDCP PDU received by the terminal device. The initial COUNT value of RX_DELIV can be obtained from the COUNT value of the first PDCP PDU received by the terminal device and the (reordered) window size (i.e. Window_Size). For example, from the initial COUNT value of RX_DELIV to the first PDCP PDU received by the terminal device The COUNT value of PDCP PDU includes a total of 0.5*Window_Size COUNT values.

Based on this solution, when the COUNT value of the first MBS data packet received by the terminal device is small (less than 0.5*2 ^{[PDCP-SN-Size]-1} ), the HFN part of the initial value of RX_DELIV will be negative. , such as -1.

For example, assuming that the length of the PDCP SN is 12 bits, the range of the PDCP SN is 0~2 ¹² -1=0~4095, and the size of the PDCP (reordering) window is 2 ^12-1 =2048. The window size Half of is equal to 0.5*2 ^12-1 = 1024. As shown in Figure 7, assuming that the PDCP SN=500 and HFN=0 of the first PDCP PDU received by the terminal device, then RX_NEXT=501. Based on a COUNT value of HFN=0, PDCP SN=500 and half the window size (i.e. 1024) the resulting RX_DELIV is negative. Among them, HFN of RX_DELIV=-1 and PDCP SN=3571.

In order to avoid the initial value of HFN of RX_DELIV being negative, a feasible implementation method is: the access network device adds 1 to the initial HFN of the PDCP PDU to obtain the final HFN of the PDCP PDU. Based on this implementation, the HFN of all PDCP PDUs of the MBS service is equal to the initial HFN plus 1. At this time, there is no PDCP PDU with HFN=0 and PDCP SN less than 0.5*2 ^{[PDCP-SN-Size]-1} on the access network device side, and the initial value of HFN of RX_DELIV will not be a negative number. The initial HFN of the PDCP PDU may be generated based on the MBS quality of service flow identifier (QoS flow identifier, QFI) SN (ie, MBS QFI SN).

For MBS services, there may be multiple access network devices transmitting data for the same MBS service. In order to ensure switching of terminal devices, different access network devices need to generate the same COUNT value for the same data packet. For example, different access network devices can generate the COUNT value of the data packet based on the MBS QFI SN of the data packet.

Among them, the MBS QFI SN of the data packet is generated by the core network equipment. When the MBS session includes multiple QoS flows, the core network device maintains the MBS QFI SN for each QoS flow in the multiple QoS flows. For example, when there are two QoS flows, the MBS QFI SN of the data packet of QoS flow 1 can range from 0 to 2 ^{MBS-QFI-SN-Size} -1, and the MBS QFI SN of the data packet of QoS flow 2 can also range from 0 to 2 MBS-QFI-SN-Size -1. 0～2MBS ^-QFI-SN-Size -1. Among them, MBS-QFI-SN-Size represents the length of the MBS QFI SN. The length can be the same as the length of the COUNT value, for example, 32 bits, so that the access network device can refer to the MBS QFI SN to generate the COUNT value. For example, the access network device can generate the COUNT value as follows:

When there is a one-to-one relationship between the MRB and the QoS flow, the access network device can intercept the K high-order bits of the MBS QFI SN as the HFN of the COUNT value, and the NK low-order bits as the PDCP SN of the COUNT value. Among them, K is the length of HFN, and N is the length of MBS QFI SN. In other words, the access network equipment can set the COUNT value equal to the MBS QFI SN. Of course, in order to avoid the initial value of HFN of RX_DELIV being negative, the access network equipment can Based on the K high-order bits of QFI SN, a certain constant is added as the HFN of the COUNT value. where the constant is greater than or equal to 1.

When there is a one-to-many relationship between an MRB and a QoS flow, the access network device can generate a COUNT value based on the MBS QFI SN of all QoS flows corresponding to the MRB.

For example, assume that there are three QoS flows with QFI equal to 1, 2, and 3 respectively. Among them, the QoS flows with QFI equal to 1 and QFI equal to 2 are associated with MRB#1, and the QoS flows with QFI equal to 3 are associated with MRB#2. As shown in Figure 8, the data packets sent by the core network equipment include: QFI SN equals 19 and 20 in the QoS flow with QFI equal to 1, QFI SN equals 48, 49, 50, 51, and QFI SN in the QoS flow with QFI equal to 2. 52 data packets, and QFI SN equals 95, 96, 97, 98, 99, 100, 101, 102, 103, 104 data packets in the QoS flow with QFI equal to 3.

For MRB#2, since it is only associated with QoS flows with QFI equal to 3, the access network device can use the QFI SN of the data packet as the COUNT value.

For MRB#1, since it is associated with QoS flows with QFI equal to 1 and QFI equal to 2, the access network device can regard the sum of the QFI SNs of the next expected received data packets of the two QoS flows as the next received The COUNT value of the packet. For example, at time A, the QFI SN of the next data packet expected to be received by QFI 1 is 20, and the QFI SN of the next data packet expected to be received by QFI 2 is 50, then the first received data packet after time A The packet's COUNT value is equal to 70.

Or, as another way not shown in Figure 8, the network device can use the sum of the maximum QFI SNs of the two QoS flows that have been received as the COUNT value of the next received data packet. For example, at time A, the maximum QFI SN of QFI 1 received is 19, and the maximum QFI SN of QFI 2 received is 49, then the COUNT value of the first received data packet after time A is equal to 68.

It should be noted that, for the convenience of drawing, MBS QFI SN is briefly described as QFSN in Figure 8. In addition, in Figure 8, the access network equipment does not add a certain constant as HFN on the basis of the K high-order bits of MBS QFI SN as an example. In practical applications, it can also be added to the K high-order bits of MBS QFI SN. Add a certain constant to obtain the final HFN. In addition, unless otherwise specified, the QFI SN in this application refers to MBS QFI SN, which can be replaced by MBS QFI SN.

When comprehensively considering the problem of avoiding the initial HFN of RX_DELIV being a negative number and the need for different access network equipment to generate the same COUNT value for the same data packet, since the lengths of the MBS QFI SN and COUNT values are the same, when the high-order bits of the MBS QFI SN are added by a certain When a constant is used as the HFN of the COUNT value, it may happen that the COUNT value has reached the upper limit, but the QFI SN has not yet reached the upper limit.

Based on this, this application provides a communication method that can effectively prevent the COUNT value in the access network device from overflowing for the MBS service, thereby improving communication reliability. Of course, the solution of this application can be used to solve the situation where the COUNT value has reached the upper limit due to any reason, but the QFI SN has not yet reached the upper limit.

The method provided by the embodiment of the present application will be described below with reference to the accompanying drawings, taking the interaction between the core network device 201, the access network device 202, and the terminal device 203 shown in Figure 2 as an example.

It can be understood that in the embodiment of the present application, the execution subject can perform some or all of the steps in the embodiment of the present application. These steps or operations are only examples. The embodiment of the present application can also perform other operations or variations of various operations. In addition, various steps may be performed in a different order than those presented in the embodiments of the present application, and it may not be necessary to perform all operations in the embodiments of the present application.

It should be noted that in the following embodiments of the present application, the names of the messages between the devices or the names of the parameters in the messages are just examples, and other names may also be used in specific implementations. This is not specifically limited in the embodiments of the present application. .

By way of example, the methods provided in the following embodiments of this application can be applied in the transmission scenario of MBS services. Of course, this is only an exemplary description of the application scenarios of the present application, and this application scenario does not impose any limitations on the present application. Please do not limit the application scenarios of the methods provided below.

As shown in Figure 9, a communication method provided by an embodiment of the present application includes the following steps:

S901. The core network device sends the first data packet to the access network device. Correspondingly, the access network device receives the first data packet from the core network device.

The first data packet is a data packet of the first QoS flow of the MBS service. The MBS QFI SN of the first packet is less than the first threshold.

Optionally, the first QoS flow is associated with the first MRB. The first QoS flow may be one QoS flow, or may include multiple QoS flows. When the first QoS flow is one QoS flow, the first MRB and the QoS flow have a one-to-one relationship; when the first QoS flow includes multiple QoS flows, the first MRB and the QoS flow have a one-to-many relationship. In addition, when the first QoS flow includes multiple QoS flows, the first data packet may be a data packet of any one of the multiple QoS flows.

Optionally, after receiving the first data packet, the access network device may send the first data packet to the terminal device through the first MRB. Wherein, the payload of the first data packet received by the access network device and the first data packet sent to the terminal device are the same, but the structures or data packet headers of the two may be different. For example, the first data packet received by the access network device is a data packet encapsulated using the GPRS tunneling protocol for the user plane (GTP-U), and the first data packet sent by the access network device to the terminal device is The data packet is a data packet encapsulated using the air interface protocol. Among them, GPRS refers to the general packet radio system (GPRS).

In the following embodiments of the present application, for convenience of description, if the payload of the data packet received by the access network device and the data packet sent by the access network device to the terminal device are the same, the same name will be used for both. But it is understood that the structure of these two packets may be different. In addition, when the MBS QFI SN attribute of the data packet appears, the data packet usually refers to the data packet received by the access network device. When the COUNT value attribute of the data packet appears, the data packet usually refers to the data packet sent by the access network device to the terminal device. sent packet. The COUNT value of the data packet can also be understood as the COUNT value of the PDCP PDU (or SDU) of the data packet.

Optionally, the access network device can determine the COUNT value of the first data packet based on the MBS QFI SN of the first data packet. Among them, in order to prevent the initial HFN of RX_DELIV from being negative, the access network equipment can add an offset value to the HFN deduced based on MBS QFI SN to obtain the HFN of the COUNT value of the first data packet, and deduced based on MBS QFI SN Get the PDCP SN of the COUNT value of the first packet. Among them, the offset value is a positive integer. The COUNT value of the data packets subsequent to the first data packet is generated in the same manner as the COUNT value of the first data packet.

Optionally, the offset value in this application can be predefined by the protocol; or it can be negotiated between access network devices; or it can be configured by the core network device, which is not specifically limited in this application.

For the first threshold, as a possible implementation, the first threshold may be 2 ^N -1, where N is the length of the MBS QFI SN.

In the embodiment of this application, the length of a parameter refers to the number of bits of the parameter. In practical applications, the length of a parameter can also be called the size of the parameter. For example, the length of MBS QFI SN can also be called the size of MBS QFI SN. The two are interchangeable.

As another possible implementation, when the access network device determines the COUNT value of the data packet based on the MBS QFI SN and offset value of the data packet, the first threshold may be greater than or equal to the corresponding MBS when the COUNT value is equal to 2 ^N -1 QFI SN increases by 1 and is less than or equal to 2 ^N -1.

S902. The access network device sends the first instruction information to the core network device. Correspondingly, the core network device receives the first indication information from the access network device.

The first indication information is used by the core network device to set the MBS QFI SN of the second data packet of the first QoS flow to be greater than or equal to 0 and smaller than the MBS QFI SN of the first data packet. The second data packet is the data packet after the first data packet.

Optionally, the access network device includes a CU, and when the CU includes a CU-UP and a CU-CP, the CU-UP may notify the CU-CP to send the first indication information, and then the CU-CP may send the first indication information to the core network device. Instructions. The content of the information sent by the CU-UP to the CU-CP and the content of the first instruction information sent by the CU-CP to the core network device may be the same or different. The information sent by the CU-UP to the CU-CP is used to notify the CU-CP to send the first indication information.

Optionally, the access network device may send the first indication information to the core network device when any of the following conditions occurs, or in other words, the access network device may send the first indication information to the core network device when any of the following conditions are met. Send the first instruction information to the core network device:

1) The maximum COUNT value of the data packet of the first MRB is equal to the second threshold.

Optionally, the maximum COUNT value of the data packet of the first MRB can be understood as: the maximum value of the COUNT values that the access network device has actually used/allocated/occupied/sent for the first MRB, rather than the maximum value that can theoretically be The maximum value of COUNT reached.

For example, when the first QoS flow is a QoS flow, after the access network device receives the first data packet and determines the COUNT value of the first data packet based on the MBS QFI SN and offset value of the first data packet, The COUNT value of the first data packet is the maximum COUNT value of the data packet of the first MRB.

Or, in the scenario where the first QoS flow includes multiple QoS flows, assume that the first QoS flow includes QoS flow A (represented by QFI#A) and QoS flow B (represented by QFI#B), and after receiving the first Before the data packet, the MBS QFI SN of the next expected QFI#A is a, and the MBS QFI SN of the next expected QFI#B is b. Then after receiving the first data packet, the access network device can add the value of the K high-order bits of a and the value of the K high-order bits of b and then add the offset value to obtain the COUNT value of the first data packet. HFN, add the N-K low-order bit values of a and b as the PDCP SN of the COUNT value of the first data packet. The COUNT value of the first data packet obtained through this calculation is the maximum COUNT value of the data packet of the first MRB.

It should be noted that when the length of the COUN value is equal to N and the length of HFN is equal to K, the length of the PDCP SN is equal to N-K. In this application, the length of PDCP SN can also be expressed by PDCP-SN-Size. In addition, the length of HFN can also be expressed as N-[PDCP-SN-Size]. That is to say, in this application, N-K can be replaced by PDCP-SN-Size, and K can be replaced by N-[PDCP-SN-Size].

Optionally, the second threshold may be less than or equal to 2 ^N -1, where N is the length of COUNT. When the length of COUNT is equal to the length of MBS QFI SN, from the perspective of COUNT, N is the length of COUNT, and from the perspective of MBS QFI SN, N is the length of MBS QFI SN.

2) The difference between the maximum COUNT value of the data packet of the first MRB and the second threshold is less than or equal to M1, where M1 is a positive integer.

For the maximum COUNT value of the data packet of the first MRB, reference may be made to the relevant description in case 1) above, which will not be described again here.

Optionally, the difference between the maximum COUNT value of the data packet of the first MRB and the second threshold is less than or equal to M1, which can also be understood as: the maximum COUNT value of the data packet of the first MRB is close to the second threshold.

Optionally, after receiving the first data packet, the access network device can calculate the COUNT value of the first data packet. When the difference between the COUNT value of the first data packet and the second threshold is less than or equal to M1, The COUNT value of the first data packet is the maximum COUNT value of the data packet of the first MRB.

3) The first MRB will be deactivated or will be released.

Optionally, the reason why the first MRB is deactivated or released may be that the above situation 1) or situation 2) occurs, or the following situation 4) or situation 5) occurs. Of course, there may also be other reasons, which are not specifically limited in this application.

4) The maximum MBS QFI SN of the first QoS flow is equal to the third threshold.

Optionally, when the access network device determines the COUNT value based on the MBS QFI SN and the offset value, the third threshold may be the MBS QFI SN such that the COUNT value is equal to the second threshold, for example, when the second threshold is 2 ^N -1 When , the third threshold is less than or equal to 2 ^N -X*2 ^{[PDCP-SN-Size]} -1. Among them, X represents the offset value.

Optionally, the maximum MBS QFI SN of the first QoS flow can be understood as: for the first QoS flow, the maximum value of the MBS QFI SN actually used by the core network equipment, rather than the theoretically achievable MBS QFI SN. Maximum value (e.g. 2 ^N -1).

Optionally, after the access network device receives the first data packet and obtains the MBS QFI SN of the first data packet, it can use the MBS QFI SN of the first data packet as the maximum MBS QFI SN of the first QoS flow.

5) The difference between the maximum MBS QFI SN of the first QoS flow and the third threshold is less than or equal to M2. Among them, M2 is a positive integer. Optional, M2 and M1 are equal.

Among them, the description of the third threshold and the maximum MBS QFI SN of the first QoS flow may refer to the relevant description in case 4) above.

It should be noted that in actual applications, when the relationships described in the above situations 1)-5) are satisfied, the access network device can send the first indication information. The descriptions of situations 1)-5) above should not be used as strict restrictions. For example, in situation 1), when the access network device determines that the maximum COUNT value of the data packet of the first MRB minus the second threshold is equal to 0, it also The first instruction information can be sent.

S903. The core network device sets the MBS QFI SN of the second data packet of the first QoS flow according to the first indication information. Among them, the MBS QFI SN of the second data packet is smaller than the MBS QFI SN of the first data packet. Further, the MBS QFI SN of the second data packet is greater than or equal to 0.

Optionally, the core network device sets the second data packet of the first QoS flow, which can also be understood as: the core network device wraps around or resets or initializes the MBS QFI SN of the first QoS flow.

Optionally, when the first QoS flow includes multiple QoS flows, the second data packet may include data packets of some of the multiple QoS flows, or the second data packet may include data packets of some of the multiple QoS flows. packets for all QoS flows.

That is to say, when the first QoS flow includes multiple QoS flows, the core network device can set the MBS QFI SN of some of the multiple QoS flows to be greater than or equal to 0 and less than the MBS QFI of the first data packet. The value of SN. Alternatively, the MBS QFI SN of all QoS flows in the multiple QoS flows may be set to a value greater than or equal to 0 and less than the value of the MBS QFI SN of the first data packet.

For example, taking the first QoS flow including QoS flow A (denoted by QFI#A) and QoS flow B (denoted by QFI#B), assuming that the first data packet is a data packet of QFI#A, then the second The data packet may be a data packet of QFI#A, or the second data packet may be a data packet of QFI#B, or the second data packet may include a data packet of QFI#A and a data packet of QFI#B.

Optionally, the core network device sets the MBS QFI SN of the second data packet of the first QoS flow according to the first indication information. It can be understood that the core network device sets the second data of the first QoS flow based on the trigger of the first indication information. Package MBS QFI SN.

Optionally, after the core network device sets the MBS QFI SN of the second data packet of the first QoS flow, the core network device can send the second data packet to the access network device. Correspondingly, after receiving the second data packet, the access network device can determine the COUNT value of the second data packet and send the second data packet to the terminal device, and include the COUNT value in the second data packet sent to the terminal device. PDCP SN.

In the existing solution, when the MBS QFI SN of the first data packet is less than 2 ^N -1, the MBS QFI SN of the data packets sent after the first data packet will increase sequentially based on the MBS QFI SN of the first data packet. The MBS QFI SN of the packets up to the first QoS flow is equal to 2 ^N -1. Based on the solution of this application, the access network equipment sends the first instruction letter to the core network equipment. information, so that when the MBS QFI SN of the first data packet is less than the first threshold, the core network device can set the MBS QFI SN of the second data packet to be greater than or equal to 0 and less than the MBS QFI of the first data packet based on the first indication information. SN. That is to say, the core network device can reset the MBS QFI SN of the data packet of the first QoS flow when the MBS QFI SN of the data packet of the first QoS flow does not reach the first threshold, effectively reducing the problem caused by excessive MBS QFI SN. The COUNT value overflows, thereby reducing packet loss caused by COUNT value overflow and improving communication reliability.

In some embodiments of the method shown in Figure 9, the second data packet is the data packet after the first data packet, which may include: the second data packet is the M3th data packet after the first data packet, and M3 is a positive integer. . Optionally, from the perspective of the access network equipment, M3 is less than or equal to M1+1, and M1 is the maximum difference between the maximum COUNT value of the data packet of the first MRB and the second threshold; from the core network equipment From the perspective of M3 is less than or equal to M2+1, M2 is the maximum difference between the maximum MBS QFI SN of the first QoS flow and the third threshold.

When M3 is equal to 1, the second data packet is the first data packet after the first data packet. In this scenario, it can be considered that after the core network device sends the first data packet, it does not send the data packet to the access network device before receiving the first indication information; or, it can be considered that after the core network device sends the first data packet, it receives Before the first indication information is received, at least one data packet is sent to the access network device, but the access network device discards this part of the data packet, and the core network device resends the at least one data packet after receiving the first indication information based on the implementation. Bag. In addition, it can be considered that the access network device sends the first indication information to the core network device when the above situation 1) or 4) occurs.

For example, assuming that the second threshold is equal to 1000 and the maximum COUNT value of the first MRB is the COUNT value of the first data packet, it is assumed that after receiving the first data packet, the access network device determines the COUNT value of the first data packet. is equal to 1000, then the access network device sends the first indication information to the core network device. After receiving the first indication information, the core network device sends a second data packet to the access network device, and the MBS QFI SN of the second data packet may be equal to 0.

When M3 is greater than 1 and less than or equal to M1 (or M2), there is at least one third data packet between the second data packet and the first data packet. In this scenario, it can be considered that after sending the first data packet, the core network device also sends the at least one third data packet to the access network device, and after the at least one third data packet, sends the third data packet to the access network device. Two data packets. In addition, it can be considered that the access network device sends the first indication information to the core network device when the above situation 2) or situation 5) occurs.

Wherein, the third data packet is a data packet of the first QoS flow. When the first QoS flow is a QoS flow, the MBS QFI SN of the third data packet is greater than the MBS QFI SN of the first data packet. When the first QoS flow is a QoS flow and there are multiple third data packets, the MBS QFI SN of the last third data packet is less than or equal to the third threshold, or the COUNT value of the last third data packet Less than or equal to the second threshold. In the case where the first QoS flow includes multiple QoS flows and there are multiple third data packets, the sum of the MBS QFI SNs of the multiple third data packets is less than or equal to the third threshold.

For example, assuming that the second threshold is equal to 1000, M1 is equal to 10, and the maximum COUNT value of the first MRB is the COUNT value of the first data packet, it is assumed that after receiving the first data packet, the access network device determines the first data The COUNT value of the packet is equal to 990, and the difference between it and the second threshold is equal to 10, that is, the difference between the maximum COUNT value of the first MRB and the second threshold is equal to M1. At this time, the access network device can send a request to the core network device. Send the first instruction message.

In the scenario where the core network device sends the first data packet but before receiving the first instruction information, the data packet is not sent to the access network device. After the core network device receives the first instruction information, it may send a data packet to the access network device. 10 third packets. At this time, the second data packet is the 11th data packet after the first data packet. Of course, the number of third data packets sent by the core network device may also be less than 10. For example, 8 third data packets are sent. In this case, the second data packet is the ninth data packet after the first data packet.

In the scenario where the core network device sends the first data packet but before receiving the first instruction information, it also sends the data packet to the access network device. After receiving the first instruction information, the core network device may send the data packet to the access network device. Send (10-M4) third data packets. Wherein, M4 is the number of data packets sent by the core network device to the access network device after sending the first data packet and before receiving the first indication information. For example, the access network device sends the first indication information to the core network device when the COUNT value of the first data packet is equal to 990. Due to the transmission delay, the core network device sends two more data packets after the first data packet. , after receiving the first indication information, the core network device can send 10-2=8 third data packets to the access network device after receiving the first indication information. At this time, the second data packet is the first data The 8th data packet after the packet. Of course, the number of third data packets sent by the core network device can also be less than (10-M4). For example, 4 third data packets are sent. In this case, the second data packet is the fifth data after the first data packet. Bag.

Optionally, when the access network device sends the first indication information to the core network device, it can also indicate the first data packet to the core network device, for example, send the MBS QFI SN of the first data packet to the core network device so that the core network device The network device determines the above M4. Of course, the access network device may not indicate the first data packet to the core network device. In this case, after receiving the first indication information, the core network device may send as few third data packets as possible before the second data packet.

Based on this solution, when the maximum COUNT value of the first MRB is close to the second threshold, or when the maximum MBS QFI SN of the first QoS flow is close to the third threshold, the access network device sends the first indication information to the core network device. A long time is reserved for the transmission of the first indication information, so that the core network equipment can receive the first indication information before the COUNT value overflows, and set the MBS QFI SN of the second data packet according to the first indication information, effectively reducing the MBS QFI The COUNT value overflow caused by excessive SN reduces packet loss caused by COUNT value overflow and improves communication reliability.

In some embodiments of the method shown in Figure 9, the content included in the first indication information may be implemented in the following two possible ways:

As a possible implementation, the first indication information may include at least one of the following a)-g):

a) Information indicating that the maximum COUNT value of the data packet of the first MRB is equal to the second threshold.

Optionally, the first indication information may include bit A. When the value of bit A is 1 or 0, it may indicate that the maximum COUNT value of the data packet of the first MRB is equal to the second threshold.

b) Information indicating that the difference between the maximum COUNT value of the data packet of the first MRB and the second threshold is less than or equal to M1.

Optionally, the first indication information may include bit B. When the value of bit B is 1 or 0, it may indicate that the difference between the maximum COUNT value of the data packet of the first MRB and the second threshold is less than or equal to M1. M1 can be defined by the protocol or pre-configured by the access network device.

Alternatively, the first indication information may include a difference between the maximum COUNT value of the data packet of the first MRB and the second threshold or M1. Among them, the difference is less than or equal to M1.

c) Information indicating the difference between the maximum COUNT value of the data packet of the first MRB and the second threshold.

Optionally, the first indication information may include a difference between the maximum COUNT value of the data packet of the first MRB and the second threshold.

Alternatively, the first indication information may include field C, and a value of field C corresponds to a difference between the maximum COUNT value of the data packet of the first MRB and the second threshold.

For example, the field C may indicate the number of remaining HFNs that can be used before the COUNT value of the data packet of the first MRB is equal to the second threshold, or the number of remaining PDCP SNs that can be used.

When field C indicates the number of remaining HFNs that can be used, the difference between the maximum COUNT value of the data packet of the first MRB and the second threshold is L*2 ^PDCP-SN-Size , and L is the remaining HFNs that can be used. number. When field C indicates the number of remaining usable PDCP SNs, the maximum COUNT value of the data packet of the first MRB is equal to the number of remaining usable PDCP SNs.

d) Status information of the first MRB.

Optionally, the status information of the first MRB may include: the first MRB (will be) deactivated, or the first MRB (will be) released, or the first MRB will no longer be used, or the first MRB cannot be used. continue to use.

e) Information indicating that the maximum MBS QFI SN of the first QoS flow is equal to the third threshold.

Optionally, the first indication information may include bit D. When the value of bit D is 1 or 0, it may be indicated that the maximum MBS QFI SN of the first QoS flow is equal to the third threshold.

f) Information indicating that the difference between the maximum MBS QFI SN of the first QoS flow and the third threshold is less than or equal to M2.

Optionally, the first indication information may include bit E. When the value of bit E is 1 or 0, it may indicate that the difference between the maximum MBS QFI SN of the first QoS flow and the third threshold is less than or equal to M2 .

Alternatively, the first indication information may include a difference between the maximum MBS QFI SN of the first QoS flow and the third threshold. Among them, the difference is less than or equal to M2.

g) Information indicating the difference between the maximum MBS QFI SN of the first QoS flow and the third threshold.

Optionally, the first indication information may include a difference between the maximum MBS QFI SN of the first QoS flow and the third threshold. Alternatively, the first indication information may include field F, and a value of field F corresponds to a difference between the maximum MBS QFI SN of the first QoS flow and the third threshold.

Further, the first indication information may also include identification information, and the identification information includes at least one of the following: an identification of the first MRB, an identification of the first QoS flow, or an identification of the MBS service. The identification information is used to indicate to the core network device that the first indication information is indication information about the first MRB, the first QoS flow, or the above-mentioned MBS service.

As another possible implementation manner, the first indication information may include at least one of the following: an identity of the first MRB, an identity of the first QoS flow, or an identity of the MBS service. Wherein, at least one of the identity of the first MRB, the identity of the first QoS flow, or the identity of the MBS service may indicate at least one of the above information a)-g).

For example, when the first indication information includes the identification of the first MRB, it may indicate the information related to the first MRB in the above a)-g). For example, it may indicate that the maximum COUNT value of the data packet of the first MRB is equal to the second threshold, or it may indicate that the difference between the maximum COUNT value of the data packet of the first MRB and the second threshold is less than or equal to M1, or it may indicate that the first MRB status information.

When the first indication information includes the identifier of the first QoS flow (or includes the identifier of the first QoS flow and the identifier of the MBS service), it may indicate the information related to the first QoS flow in the above a)-g). For example, it may be indicated that the maximum MBS QFI SN of the first QoS flow is equal to the third threshold, or it may be indicated that the difference between the maximum MBS QFI SN of the first QoS flow and the third threshold is less than or equal to M2.

Of course, since there is an association relationship between the first MRB and the first QoS flow, when the first indication information includes the identification of the first MRB, the information related to the first QoS flow in a)-g) may also be indicated. When the first indication information includes the identifier of the first QoS flow (or includes the identifier of the first QoS flow and the identifier of the MBS service), the information related to the first MRB in a)-g) may also be indicated.

Optionally, the first indication information can be carried in an existing information element (IE) or in a newly defined IE, which is not specifically limited in this application.

In some embodiments of the method shown in Figure 9, the access network device may release the first MRB and establish the second MRB. The second data packet is carried on the second MRB.

Optionally, the related configuration of the second MRB and the related configuration of the first MRB may be the same or different, and this application does not specifically limit this.

Optionally, the establishment of the second MRB may be performed after the release of the first MRB is completed. Alternatively, it can be executed before releasing the first MRB. For example, the access network device may establish the second MRB before sending the first data to the terminal device through the first MRB, which is not specifically limited in this application. If the access network device establishes the second MRB before releasing the first MRB, Then, after receiving the second data packet, the access network device can promptly send the second data packet to the terminal device, thereby reducing service delay.

As a possible implementation, the access network device may release the first MRB after sending the first data packet to the terminal device through the first MRB.

As another possible implementation, the access network device may release the first MRB after receiving the second data packet. In this scenario, if the access network device establishes the second MRB after releasing the first MRB, the access network device needs to cache the second data packet, and after the second MRB is established, send the second MRB to the terminal device through the second MRB. Two data packets.

As another possible implementation, when the third data packet exists, the access network device may release the first MRB after sending the first data packet and the third data packet to the terminal device through the first MRB. Alternatively, after sending the first data packet and the third data packet to the terminal device through the first MRB and receiving the second data packet, the first MRB is released.

Optionally, the access network device releasing the first MRB may include: sending a first signaling to the terminal device, the first signaling being used to release the first MRB.

Optionally, the access network device may send the first signaling to the terminal device based on the status indication information reported by the terminal device. That is to say, after receiving the status indication information from the terminal device, the access network device sends the first signaling to the terminal device.

As a possible implementation, the status indication information may be used to indicate the maximum COUNT value of the data packet of the first MRB successfully received by the terminal device.

Optionally, in this possible implementation, after receiving the status indication information, the access network device can determine whether the maximum COUNT value of the data packet of the first MRB successfully received by the terminal device is equal to the second threshold. If equal, the first signaling is sent to the terminal device.

Alternatively, in this possible implementation, the access network device may configure a second threshold to the terminal device in advance, so that when the maximum COUNT value of the successfully received data packet of the first MRB is equal to the second threshold, the terminal device sends a request to the access network device. The network device sends this status indication information. Alternatively, the second threshold and M1 may be configured in advance for the terminal device, so that when the difference between the maximum COUNT value of the successfully received data packet of the first MRB and the second threshold is less than or equal to M1, the terminal device will access the terminal device. The network device sends this status indication information. At this time, after receiving the status indication information, the access network device may not perform judgment and immediately send the first signaling to the terminal device.

For example, assuming that the COUNT value of the first data packet is equal to the second threshold, the terminal device may send the status indication information to the access network device after successfully receiving the first data packet.

As another possible implementation, the status indication information is used to indicate the maximum COUNT value of the data packet of the first MRB successfully received by the terminal device, and the data packet whose COUNT value is smaller than the maximum COUNT value has been submitted to the upper layer. Among them, at the receiving end, the upper layer refers to the protocol layer that processes data packets after the PDCP layer, such as the SDAP layer or application layer.

Alternatively, in this possible implementation, the access network device may pre-configure the second threshold, or pre-configure the second threshold and M1. Reference may be made to the above related description, which will not be described again here.

As another possible implementation, the status indication information is used to indicate the COUNT value of the first PDCP SDU that has not been submitted to the upper layer but is waiting to be submitted, that is, it is used to indicate RX_DELIV.

Optionally, in this possible implementation, after receiving the status indication information, the access network device can determine whether RX_DELIV is greater than or equal to the second threshold, and if RX_DELIV is greater than or equal to the second threshold, send the first message to the terminal device. signaling.

Alternatively, in this possible implementation, the access network device may configure the second threshold to the terminal device in advance, so that the terminal device sends the status indication information to the access network device when RX_DELIV is greater than or equal to the second threshold. At this time, the access network After receiving the status indication information, the device may immediately send the first signaling to the terminal device without performing judgment.

Based on this solution, the access network device releases the first MRB based on the status information reported by the terminal device, which can avoid data loss caused by releasing the first MRB when the terminal device uses the first MRB, and improves the reliability of communication.

Optionally, the access network device establishing the second MRB may include: sending second signaling to the terminal device, the second signaling being used to establish the second MRB.

Optionally, when the access network device establishes the second MRB after releasing the first MRB, the first signaling and the second signaling may be carried in the same message, or the first signaling and the second signaling may be carried In the two messages, this application does not specifically limit this.

Optionally, the access network device may perform the above step 902 when the status of the MBS service is deactivated. Because in the deactivated state, the core network equipment does not send MBS service data, and the RRC connection of the terminal equipment may be released. When releasing the RRC connection, the MRB needs to be released. At this time, the first MRB can be released without the access network device sending the first signaling, thereby saving signaling overhead. Subsequently, when the status of the MBS service changes from the deactivated state to the activated state, the access network device needs to re-establish an RRC connection with the terminal device. During the process of re-establishing the RRC connection, a new MRB needs to be created. Therefore, when the access network device does not send the second signaling, the second MRB can also be created, which also saves signaling overhead.

In the method shown in Figure 9, based on the first indication information of the access network device, the core network device sets the MBS QFI SN of the data packet of the QoS flow before the MBS QFI SN of the QoS flow reaches the first threshold, thereby reducing the MBS QFI SN process. The COUNT value overflows due to a large value. In addition, this application also provides a communication method in which the core network device can limit the MBS QFI SN from being too large by releasing the MBS session or deleting the QoS flow, thereby reducing the COUNT value overflow caused by the MBS QFI SN being too large. As shown in Figure 10, the communication method includes the following steps:

S1001. The access network device generates second indication information.

Optionally, before step S1001, the core network device may send the first data packet to the access network device. Correspondingly, the access network device receives the first data packet from the core network device. The first data packet is a data packet of the first QoS flow of the MBS service, and the MBS QFI SN of the first data packet is less than the first threshold. The first QoS flow is associated with the first MRB. The first QoS flow is the QoS flow in the first MBS session of the MBS service.

Optionally, the access network device may generate the second indication information when any of the following conditions occurs, or in other words, the access network device may generate the second indication when any of the following conditions are met. information:

3) The first MRB will be deactivated or will be released.

For descriptions of these five situations, reference may be made to the relevant descriptions in the above step S902, which will not be described again here.

In some embodiments, when the access network device generates the second indication information when any of the above situations 1)-5) occurs:

As a possible implementation, the second indication information is used by the core network device to release the first MBS session of the MBS. Further, the second indication information can also be used by the core network device to establish a second MBS session of the MBS service.

As another possible implementation, the second indication information is used by the core network device to delete the first QoS flow of the first MBS session. Further, the second indication information can also be used by the core network device to add the second QoS in the first MBS session. flow.

In other embodiments, without limiting the conditions for the access network device to generate the second indication information:

As a possible implementation, the second instruction information is used by the core network device to release the first MBS session of the MBS and establish the second MBS session of the MBS service.

As another possible implementation, the second indication information is used by the core network device to delete the first QoS flow of the first MBS session and add the second QoS flow to the first MBS session.

S1002. The access network device sends the second instruction information to the core network device. Correspondingly, the core network device receives the second indication information from the access network device.

After receiving the second instruction information, the core network device may perform the following step S1003a, or perform the following step S1003b.

For example, when the second instruction information is used by the core network device to release the first MBS session of the MBS and establish the second MBS session of the MBS service, the following step S1003a is performed. When the second instruction information is used for the core network device to delete the first QoS flow of the first MBS session and add the second QoS flow to the first MBS session, the following step S1003b is performed.

S1003a. The core network device releases the first MBS session of the MBS service according to the second instruction information, and establishes the second MBS session of the MBS service.

Optionally, in step S1003a, it can be considered that the core network device releases the first MBS session based on the trigger of the second indication information and establishes the second MBS session.

Optionally, the session identifier, temporary multicast group identifier (TMGI), etc. of the first MBS session and the second MBS session may be the same or different, and this application does not specifically limit this.

Optionally, the core network device can release the first MBS session with the terminal device as the granularity, and correspondingly, establish the second MBS session with the terminal device as the granularity. Alternatively, the core network device may delete the first MBS session with the MBS service as the granularity, and correspondingly, establish the second MBS session with the MBS service as the granularity.

Optionally, the core network device releasing the first MBS session of the MBS service may include: the core network device sending third signaling to the access network device, the third signaling being used to release the first MBS session. The core network device establishing the second MBS session may include: the core network device sending fourth signaling to the access network device, where the fourth signaling is used to establish the second MBS session.

S1003b. The core network device deletes the first QoS flow of the first MBS session according to the second instruction information, and adds the second QoS flow to the first MBS session.

Optionally, in step S1003, it can be considered that the core network device deletes the first QoS flow of the first MBS session based on the triggering of the second indication information, and adds the second QoS flow to the first MBS session. The QFIs of the first QoS flow and the second QoS flow may be the same or different, and this application does not specifically limit this.

Optionally, the second QoS flow is used to transmit data planned to be transmitted using the first QoS flow. That is, the second QoS flow can be understood as a substitute QoS flow for the first QoS flow, realizing the functions that should be realized by the first QoS flow.

Optionally, the core network device deleting the first QoS flow of the first MBS session may include: the core network device sending a fifth signaling to the access network device, the fifth signaling being used to delete the first QoS flow. The core network device adding the second QoS flow to the first MBS session may include: the core network device sending sixth signaling to the access network device, the sixth signaling being used to add the second QoS flow to the first MBS session. .

Optionally, the fifth signaling and the sixth signaling may be carried in the same message, or may be carried in two messages, which is not specifically limited in this application. For example, the message carrying the fifth signaling and/or the sixth signaling may be a service update request message. The service update request message may be based on the MBS session as the granularity or the terminal device as the granularity.

Optionally, when the MBS session is released, the QoS flow of the MBS session is deleted. When a QoS flow is deleted, the MRB associated with the QoS flow also needs to be released. Therefore, after step S1003a or S1003b, the access network device can release Place the first MRB and build the second MRB. The second MRB may be associated with the QoS flow in the second MBS session, or may be associated with the second QoS flow added in the first MBS session. For the release of the first MRB and the establishment of the second MRB, reference may be made to the relevant description in the embodiment shown in FIG. 9 , which will not be described again here.

Based on this solution, the core network device can release the first MBS session of the MBS service based on the second instruction information of the access network device, and establish the second MBS session of the MBS service. Because when the first MBS session is released, the QoS flow of the first MBS session is deleted. After the second MBS session is created, the QoS flow in the second MBS session is also newly created. Therefore, the core network device subsequently passes the third MBS session. When the QoS stream in the second MBS session transmits the data packet of the MBS service, the MBS QFI SN of the data packet can start from 0, and the corresponding COUNT value of the data packet is smaller. Therefore, the access network device can send the second indication information according to the actual situation, for example, when the COUNT value is about to overflow, so that the MBS QFI SN of subsequent data packets is smaller, thereby reducing the COUNT value overflow caused by the MBS QFI SN being too large. This reduces packet loss caused by COUNT value overflow and improves communication reliability.

Alternatively, the core network device may delete the first QoS flow of the first MBS session based on the second indication information of the access network device, and add the second QoS flow to the first MBS session. Since the second QoS flow is newly added, when the core network equipment subsequently transmits the MBS service data packet through the second QoS flow, the MBS QFI SN of the data packet can start from 0, thereby reducing the MBS QFI SN from being too large. The resulting COUNT value overflows and improves communication reliability.

In some embodiments of the method shown in Figure 10, the content included in the second indication information may be implemented in the following two possible ways:

As a possible implementation, the second indication information may include at least one of the following a)-g):

d) Status information of the first MRB.

Further, the second indication information may also include identification information, and the identification information includes at least one of the following: an identification of the first MRB, an identification of the first QoS flow, or an identification of the MBS service. The identification information is used to indicate to the core network device that the second indication information is indication information about the first MRB, the first QoS flow, or the above-mentioned MBS service.

As another possible implementation manner, the second indication information may include at least one of the following: an identity of the first MRB, an identity of the first QoS flow, or an identity of the MBS service. Wherein, at least one of the identity of the first MRB, the identity of the first QoS flow, or the identity of the MBS service may indicate at least one of the above information a)-g).

For a detailed description of the content included in the second indication information, please refer to the relevant description in the above-mentioned first indication information, which will not be described again here.

Optionally, after receiving the second indication information, the core network device can learn that the reason for releasing the first MBS session or deleting the first QoS flow of the first MBS session is: MRB (will) be stopped from use, MRB (will be) One or more of the items will be released or the MRB will be reset. Therefore, in the above third signaling, the core network device may indicate the reason for releasing the first MBS session, or in the above fifth signaling, the core network device may indicate the reason for deleting the first QoS flow.

For the MBS service, there may be multiple access network devices sending data of the MBS service. Among the multiple access network devices, there may be some access network devices that need to generate the same COUNT value for the same data packet (called synchronized access network devices), while other access network devices do not need to generate the same COUNT value for the same data packet. generate the same COUNT value (called out of sync access network equipment). When the core network device may send the third signaling or the fifth signaling to each of the multiple access network devices, each access network device may determine whether to respond based on the above reasons indicated in the signaling. Should signal.

For example, the synchronized access network device can respond to the signaling according to the above reasons indicated in the signaling, that is, perform related actions of releasing the MBS session or deleting the QoS flow. Access network equipment that is not synchronized may not respond to the signaling based on the above reasons indicated in the signaling.

For the method shown in Figure 9 or Figure 10, since the synchronized access network equipment generates the same COUNT value for the same data packet, each synchronized access network equipment may perform the above step S902 or step S1002. At this time, the core network equipment will be forced to process a large amount of the same information. Based on this, the core network device can designate a synchronized access network device to perform the above step S902 or S1002. Alternatively, multiple synchronized access network devices may negotiate and determine that one of the access network devices performs the above step S902 or S1002. At this time, the core network equipment does not need to process a large amount of the same information, which reduces the data processing complexity of the core network equipment.

In addition to the communication methods shown in Figures 9 and 10, this application also provides another communication method. As shown in Figure 11, the method includes the following steps:

S1101. The access network device generates third indication information. The third indication information indicates the maximum value and/or the minimum value of the MBS QFI SN.

Among them, the maximum value and minimum value of the MBS QFI SN can be understood as capability values, that is, the maximum value that the MBS QFI SN can obtain and the minimum value that the MBS QFI SN can obtain. Or, the maximum and minimum values of the MBS QFI SN are used to limit the value range of the MBS QFI SN of a certain QoS flow. For example, the value range of the MBS QFI SN of a certain QoS flow can be any of the following: [0, maximum value], [minimum value, 2 ^N -1], or [minimum value, maximum value]. Among them, N is the length of MBS QFI SN.

Optionally, the maximum value of the MBS QFI SN can be used to limit the overflow of the COUNT value, or the maximum value of the MBS QFI SN can be understood as the maximum value that the access network device can accept, and the maximum value that the access network device can accept. That is, the maximum MBS QFI SN corresponding to the COUNT value that does not overflow. For example, the maximum value of the MBS QFI SN is less than 2 ^N -1.

Optionally, the minimum value of the MBS QFI SN can be used to avoid the initial value of the HFN of RX_DELIV being negative. For example, the minimum value of the MBS QFI SN is greater than 0.

Optionally, the third indication information may explicitly indicate the maximum value and/or the minimum value, for example, the third indication information includes the maximum value and/or the minimum value.

Alternatively, the third indication information may implicitly indicate the maximum value and/or the minimum value. For example, the third indication information may include parameters for determining the maximum value and/or the minimum value. The parameters used to determine the maximum value and/or the minimum value will be described in subsequent embodiments and will not be described again here. For another example, a set of maximum values and/or a set of minimum values may be predefined, and in this case, the third indication information may include the index of the maximum value and/or the index of the minimum value.

S1102. The access network device sends third instruction information to the core network device. Correspondingly, the core network device receives the third indication information from the access network device.

S1103. The core network device obtains the maximum value and/or the minimum value of MBS QFI SN.

As a possible implementation, the core network device can obtain the maximum value and/or the minimum value of the MBS QFI SN according to the third indication information.

Optionally, when the third indication information indicates the parameters used to determine the maximum value and/or the minimum value, step S1003 may be: the core network device determines the maximum value according to the parameters indicated by the third indication information, and /or, min.

As another possible implementation manner, the access network device may not send the third indication information, that is, the above steps S1101 and S1102 are optional steps. At this time, in step S1103, the core network device can use default parameter values to determine the maximum value and/or minimum value of the MBS QFI SN; or use default values (such as default parameters, fixed values) to determine the MBS QFI The maximum value, and/or the minimum value of SN.

As another possible implementation manner, when the access network device indicates to the core network device some of the parameters used to determine the maximum value and/or the minimum value, another part of the parameters used to determine the maximum value and/or the minimum value may be Use default parameters or default parameter values.

When a certain MRB is only associated with the first QoS flow, the following steps S1104a-S1105a may be performed; when a certain MRB is associated with the first QoS flow and the second QoS flow, the following steps S1104b-S1105b may be performed.

S1104a. The core network device sends the first data packet to the access network device. Correspondingly, the access network device receives the first data packet from the core network device.

Among them, the MBS QFI SN of the first data packet is less than or equal to the maximum value of the above-mentioned MBS QFI SN, and/or, is greater than or equal to the minimum value of MBS QFI SN.

That is to say, the value range of the MBS QFI SN of the first data packet can be any of the following: [0, maximum value], [minimum value, 2 ^N -1], or [minimum value, maximum value].

Wherein, the first data packet is a data packet of the first QoS flow.

S1105a. The access network device sends the first data packet to the terminal device. Correspondingly, the terminal device receives the first data packet from the access network device.

Optionally, when the third indication information indicates the maximum value of MBS QFI SN, or when the value range of MBS QFI SN of the first data packet is [0, maximum value], the HFN of the COUNT value of the first data packet It is equal to the sum of the value of the K high-order bits of the MBS QFI SN of the first data packet and the offset value. K is the length of the HFN. The PDCP SN of the COUNT value of the first data packet is equal to the value of the N-K low-order bits of the MBS QFI SN of the first data packet.

In this method, it can be considered that the MBS QFI SN that causes the COUNT value of the first data packet to overflow is discarded. In addition, the HFN of the COUNT value of the first data packet is equal to the sum of the value of the K high-order bits of the MBS QFI SN of the first data packet and the offset value, so that the initial value of HFN of RX_DELIV will not be a negative value. Moreover, the maximum MBS QFI SN of the first data packet is the above-mentioned maximum value, and this maximum value can ensure that the COUNT value of the first data packet will not overflow. Therefore, in this method, the MBS QFI SN of the first data packet will not cause the initial value of HFN of RX_DELIV to be a negative value, and the COUNT value of the first data packet will not overflow.

Optionally, when the third indication information indicates the minimum value of the MBS QFI SN, or when the value range of the MBS QFI SN of the first data packet is [minimum value, 2 ^N -1], the COUNT of the first data packet The value is equal to the MBS QFI SN of the first packet.

In this method, it can be considered that the MBS QFI SN that makes the initial value of HFN of RX_DELIV be a negative value is discarded. Furthermore, some MBS QFI SNs that will not cause the initial value of HFN of RX_DELIV to be negative may also be discarded. In addition, the COUNT value of the first data packet is equal to the MBS QFI SN of the first data packet, and the maximum MBS QFI SN of the first data packet is 2 ^N -1, so that the maximum COUNT value of the first data packet is 2 ^N -1, The overflow of the COUNT value of the first data packet is avoided. Therefore, in this method, the MBS QFI SN of the first data packet will not cause the initial value of HFN of RX_DELIV to be a negative value, and the COUNT value of the first data packet will not overflow.

Optionally, when the third indication information indicates the maximum value and minimum value of the MBS QFI SN, the HFN of the COUNT value of the first data packet is equal to the value of the K high-order bits and the offset value of the MBS QFI SN of the first data packet. The sum of the PDCP SN of the COUNT value of the first packet is equal to the value of the N-K low-order bits of the MBS QFI SN of the first packet. Alternatively, the COUNT value of the first data packet is equal to the MBS QFI SN of the first data packet.

In the same way as the above analysis, in this method, the MBS QFI SN of the first data packet will not make the initial value of HFN of RX_DELIV a negative value, and the COUNT value of the first data packet will not overflow.

S1104b. The core network device sends the first data packet and the second data packet to the access network device. Correspondingly, access network equipment Receive the first data packet and the second data packet from the core network device.

Wherein, the first data packet is a data packet of the first QoS flow. The second data packet is a data packet of the second QoS flow.

Among them, the sum of the MBS QFI SN of the first data packet and the MBS QFI SN of the second data packet is less than or equal to the maximum value of the above MBS QFI SN; and/or,

The sum of the MBS QFI SN of the first data packet and the MBS QFI SN of the second data packet is greater than or equal to the minimum value of the MBS QFI SN.

That is to say, for multiple QoS flows associated with a certain MRB, the value range of the sum of the MBS QFI SNs of the data packets of the multiple QoS flows can be any of the following: [0, maximum value], [minimum value , 2 ^N -1], or [minimum value, maximum value]. Among them, "multiple" refers to two or more. This application only takes an MRB associated with two QoS as an example for explanation.

S1105b. The access network device sends the first data packet and the second data packet to the terminal device. Correspondingly, the terminal device receives the first data packet and the second data packet from the access network device.

Among them, the COUNT value of the first data packet can refer to the MBS QFI SN of the next data packet expected to be received in the first QoS flow, the MBS QFI SN of the next data packet expected to be received in the second QoS flow, and the offset. The value is determined. The method for determining the COUNT value of the second data packet is the same as the method for determining the COUNT value of the first data packet.

It can be understood that no matter how the COUNT values of the first data packet and the second data packet are determined, the value range of the sum of the MBS QFI SN of the first data packet and the second data packet is one of the above three ranges. In this case, the MBS QFI SN of the first data packet and the second data packet will not cause the initial value of HFN of RX_DELIV to be a negative value, and the COUNT value of the first data packet and the second data packet will not overflow.

It is understandable that after the core network device obtains the value range of the MBS QFI SN, when the MRB and QoS flow have a one-to-one relationship, the MBS QFI SN of the QoS flow can start from the lower boundary of the value range, and then Increasingly until the value of the MBS QFI SN of the QoS flow is equal to the upper boundary of the value range. After the MBS QFI SN value of the QoS flow reaches the upper boundary, the MBS QFI SN value of the QoS flow starts again from the lower boundary of the value range, and so on.

When MRB and QoS flows have a one-to-many relationship, the sum of the MBS QFI SNs of the multiple QoS flows can start from the lower boundary of the value range, and then increase in sequence until the sum of the MBS QFI SNs of the multiple QoS flows The sum is equal to the upper bound of the value range. Subsequently, the MBS QFI SNs of some or all of the multiple QoS flows can be reset so that the sum of the MBS QFI SNs of the multiple QoS flows still starts from the lower boundary of the value range, and so on.

Optionally, on the access network device side, for a certain MRB, whether the MRB is associated with one QoS flow or multiple QoS flows, the access network device can release the MRB after the COUNT value of the MRB is equal to 2 ^N -1 this MRB and create another MRB.

Optionally, when an MRB is associated with a QoS flow, the access network device can release the MRB and create a new MRB after the MBS QFI SN of the received data packet is equal to the lower boundary of the MBS QFI SN value range. Another MRB. Alternatively, the access network device can release the MRB and create another MRB when the MBS QFI SN of the currently received data packet is smaller than the MBS QFI SN of the last received data packet.

Optionally, when a certain MRB is associated with multiple QoS flows, the access network device can receive the MBS QFI SN of the data packets of the multiple QoS flows after the sum is equal to the lower boundary of the above value range. Release the MRB and create another MRB. Or, for any QoS flow among the multiple QoS flows, if the MBS QFI SN of the currently received data packet of the QoS flow is less than the MBS QFI SN of the last received data packet of the QoS flow, the access network The device can also release the MRB and create another MRB.

Among them, the newly created MRB and the released MRB can be associated with the same QoS flow.

Based on this solution, the access network equipment can send the third indication information to the core network equipment to indicate the MBS QFI SN. The maximum value and/or minimum value makes the maximum value and/or minimum value of MBS QFI SN flexible. For example, the access network device can flexibly indicate the maximum value and/or the minimum value of the MBS QFI SN to the core network device according to actual needs. When the access network equipment needs to avoid COUNT value overflow, it can indicate to the core network equipment the maximum value of the MBS QFI SN used to limit the COUNT value overflow, thereby reducing the COUNT value overflow caused by the MBS QFI SN being too large, thereby reducing the COUNT value overflow. Packet loss caused by overflow improves communication reliability.

Alternatively, when the access network device does not send the third indication information, the core network device can also obtain the maximum value and/or the minimum value of the MBS QFI SN, and can also make the maximum value and/or the minimum value flexibly variable. When it is necessary to avoid COUNT value overflow, the core network equipment can set the maximum value of MBS QFI SN that limits COUNT value overflow, thereby reducing COUNT value overflow caused by excessive MBS QFI SN.

In addition, when the core network device only obtains the minimum value of MBS QFI SN, since the COUNT value of the data packet is equal to the MBS QFI SN of the data packet, and the maximum MBS QFI SN can only be 2 ^N -1, therefore, the COUNT value of the data packet The maximum COUNT value is also 2 ^N -1, which avoids overflow of the COUNT value.

In some embodiments of the method shown in Figure 11, the maximum value of the MBS QFI SN is determined based on at least one of the length N of the MBS QFI SN, the length of the PDCP SN, or the offset value. Among them, the offset value is used to determine the HFN of the COUNT value of the data packet.

As a possible implementation, the maximum value of MBS QFI SN can satisfy the following formula:
MBS QFI SN _max =2 ^N -Y

Optionally, Y can be a larger value defined by the protocol or preset. For example, when the length of the PDCP SN is 12 bits, Y can be defined or set to be greater than or equal to 4097; when the length of the PDCP SN is 18 bits, Y can be defined or set to be greater than or equal to 262145. If the core network device cannot know whether the length of the PDCP SN is 12 bits or 18 bits, you can define or set Y to be greater than or equal to 262145.

Alternatively, Y can satisfy the following formula:
Y≥X*2 ^{[PDCP-SN-Size]} +Q ₁

That is to say,
MBS QFI SN _max ≤2 ^N -X*2 ^{[PDCP-SN-Size]} -Q ₁

Among them, X represents the offset value, * represents the multiplication operation, PDCP-SN-Size represents the length of the PDCP SN, and Q ₁ is an integer greater than or equal to 1.

It can be understood that when the offset value is equal to 1, the maximum value of MBS QFI SN satisfies the following formula:
MBS QFI SN _max ＝2 ^N -2 ^{[PDCP-SN-Size]} -Q ₁

It should be noted that when the offset value is equal to 1, the offset value does not need to be reflected in the protocol. The access network device can default the offset value to be equal to 1, thereby determining the COUNT value of the data packet based on the offset value being equal to 1.

As another possible implementation, the maximum value of MBS QFI SN can satisfy one of the following formulas:

MBS QFI SN _max =X*Q ₃ -Q ₀ ; or

Among them, Q ₀ , Q ₃ , Q ₄ and Q ₅ are integers.

In some embodiments of the method shown in Figure 11, the minimum value of the MBS QFI SN is determined based on at least one of the length N of the MBS QFI SN, the length of the PDCP SN, or the offset value.

As a possible implementation, the minimum value of MBS QFI SN and the length of PDCP SN can satisfy one of the following two formulas:
MBS QFI SN _min =2 ^{[PDCP-SN-Size]}
MBS QFI SN _min =0.5*2 ^{[PDCP-SN-Size]-1}

Among them, MBS QFI SN _min represents the minimum value of MBS QFI SN, PDCP-SN-Size represents the length of PDCP SN, and * represents multiplication operation.

As another possible implementation, the minimum value of MBS QFI SN, the length of PDCP SN, and the offset value can satisfy the following formula:
MBS QFI SN _min =X*2 ^{[PDCP-SN-Size]} +Q ₂

Among them, X represents the offset value, and Q ₂ is an integer greater than or equal to 0.

As another possible implementation, the minimum value of MBS QFI SN can satisfy one of the following formulas:
MBS QFI SN _min =X*Q ₆ +Q ₇

Among them, Q ₆ , Q ₇ , Q ₈ and Q ₉ are integers.

Optionally, in the above calculation method of the maximum and minimum values of MBS QFI SN, if the access network equipment does not send the third indication information, or the third indication information does not indicate all parameters, then the core network equipment can use Default parameter values are used for calculations. For example, when calculating the maximum value, the default PDCP SN length can be or 18; when calculating the minimum value, the default PDCP SN length can be 18 bits. Alternatively, the default offset value can be 1 when calculating maximum and minimum values.

Optionally, the method shown in Figure 11 can be executed before the core network device transmits the data packet of the MBS service to the access network device. For example, it can be executed during the MBS session establishment process. Of course, it can also be executed at other times before the core network device transmits the data packet of the MBS service to the access network device, and this application does not specifically limit this.

The above-mentioned methods shown in Figures 9 to 11 all involve the relevant implementation of core network equipment and access network equipment. In addition, as shown in Figure 12, this application also provides a communication method. This communication method mainly involves the implementation of access network equipment. When the MBS QFI SN or COUNT value of the data packet meets certain conditions, the access network equipment , perform the release and establishment of MRB.

It should be noted that in the communication method shown in Figure 12, the value range of the MBS QFI SN of a certain QoS flow is [0, 2 ^N -1]. Among them, N is the length of MBS QFI SN. In addition, the communication method shown in Figure 12 can be executed while the MBS QFI SN of a certain QoS flow increases from 0 to 2 ^N -1. Referring to Figure 12, the communication method includes the following steps:

S1201. The core network device sends the first data packet to the access network device. Correspondingly, the access network device receives the first data packet from the core network device.

The first data packet is a data packet of the first QoS flow of the MBS service. The first QoS flow may be associated with the first MRB. The MBS QFI SN of the first packet belongs to [0,2 ^N -1]. Optionally, after receiving the first data packet, the access network device may send the first data packet to the terminal device through the first MRB, that is, the first data packet is carried on the first MRB.

S1202. When the MBS QFI SN of the first data packet meets the first condition, the access network device releases the first MRB and establishes the second MRB associated with the first QoS flow.

Optionally, in step S1202, when the MBS QFI SN of the first data packet meets the first condition, releasing the first MRB may include: when the MBS QFI SN of the first data packet meets the first condition, and through the first After the MRB sends the first data packet to the terminal device, the first MRB is released.

Based on this solution, when the MBS QFI SN of the received data packet meets the first condition, the access network device releases the first MRB carrying the data packet and creates a second MRB. That is to say, in the process of increasing the MBS QFI SN of the first QoS flow from 0 to 2 ^N -1, the access network device can perform the release and creation of the MRB at least once. After a new MRB is created, the COUNT value of the MRB's data packets can start from the minimum value that can be obtained. Therefore, the MBS QFI of the first QoS flow When SN increases from 0 to 2 ^N -1, the COUNT value can be flipped at least once, thereby reducing the risk of COUNT value overflow and improving communication reliability.

Considering that the data packets of the MBS service are usually larger than 2 ^N -1, in order to make the MBS QFI SN of a certain QoS flow increase from 0 to 2 ^N -1 each time, the above step S1202 can be used to release and release the MRB. New. In some embodiments, the method shown in Figure 12 may also include the following steps S1203-S1204:

S1203. The core network device sends the second data packet to the access network device. Correspondingly, the access network device receives the second data packet from the core network device.

The second data packet is a data packet of the first QoS flow. After receiving the second data packet, the access network device may send the second data packet to the terminal device through the third MRB, that is, the second data packet is carried on the third MRB.

S1204. When the MBS QFI SN of the second data packet is equal to 2 ^N -1, the access network device releases the third MRB associated with the first QoS flow and establishes the fourth MRB associated with the first QoS flow.

In other words, the access network equipment can release the current MRB and create a new MRB when the MBS QFI SN is equal to 2 ^N -1 to carry subsequent data packets.

Optionally, after receiving the second data packet, the access network device may send the second data packet to the terminal device through the third MRB, and then release the third MRB after the second data packet is sent. That is to say, step S1204 can be understood as:

When the MBS QFI SN of the second data packet is equal to 2 ^N -1, and after the access network device sends the second data packet to the terminal device, it releases the third MRB and establishes the fourth MRB associated with the first QoS flow.

Optionally, during the process of the MBS QFI SN of the first QoS flow from 0 to 2 ^N -2, if the access network device releases and creates multiple MRBs, then the third MRB can be used by the access network device away from the current one. The latest MRB created during the release process; if the access network device has released and created an MRB once, then the third MRB and the second MRB are the same.

The overall flow of the method shown in Figure 12 has been described above, and the first condition will be explained below.

In some embodiments of the method shown in Figure 12, the first condition is related to the first value. For example, the first condition may include one of the following items:

(1) The MBS QFI SN of the first data packet is greater than 0 and is evenly divided by the first value;

(2) The MBS QFI SN of the first data packet plus 1 divides the first value; or,

(3) The MBS QFI SN of the first data packet is equal to the first value.

Optionally, the MBS QFI SN of the first data packet is greater than 0 and is evenly divided by the first value, which can also be understood as: the MBS QFI SN of the first data packet is greater than 0 and modulo the first value is equal to 0. The MBS QFI SN of the first data packet plus 1 divides the first value, which can also be understood as: the MBS QFI SN of the first data packet plus 1 modulo the first value is equal to 0.

As a possible implementation, the first value is determined based on the length of the MBS QFI SN and/or the length of the PDCP SN.

For example, the first numerical value may satisfy one of the following formulas (a)-(e):
S ₁ =2 ^NM (a)
S ₁ =2 ^NM -1 (b)
S ₁ =2 ^PDCP-SN-Size -1 (c)
S ₁ ≥0.5*2 ^{[PDCP-SN-Size]-1} -1 (d)
S ₁ ＝2 ^N -X*2 ^PDCP-SN-Size -1 (e)

Among them, S ₁ represents the first numerical value, N represents the length of the MBS QFI SN, M is a positive integer, PDCP-SN-Size represents the length of the PDCP SN, * represents the multiplication operation, X represents the offset value, and the offset value is used to determine HFN of the packet's COUNT value.

It should be noted that when the first condition is the above-mentioned condition (1), the first numerical value can satisfy any one of the above-mentioned formulas (a)-(e); when the first condition is the above-mentioned condition (2), the first value A numerical value can also satisfy any one of the above formulas (a)-(e); similarly, when the first condition is the above-mentioned condition (3), the first numerical value can also satisfy any of the above formulas (a)-(e). any kind. That is, the first numerical value may not be different depending on the first condition.

As another possible implementation, the first value is a preset value. The preset value may be defined by the protocol, or may be determined by the access network device itself. For example, the preset value may be 10,000. Of course, the preset value can also be other values, which is not specifically limited in this application.

It should be noted that the position of the released MRB calculated based on the above first condition and the first numerical value all fall within the protection scope of the present application. That is to say, this application intends to protect the position where the MRB is released, and does not limit the position where the MRB is released to be determined based on the above-mentioned first condition and first value.

Optionally, when the first condition includes the above condition (2) and the first value satisfies the above formula (a), 2 ^N data packets of the first QoS flow can be carried on 2 ^M MRBs. Among them, the MBS QFI SN of the starting data packet among the 2 ^N data packets is 0, and the MBS QFI SN of the terminating data packet is 2 ^N-1 . The ^2M MRBs can use the same or different configurations.

That is to say, for 2 ^N data packets with MBS QFI SN of the first QoS flow from 0 to 2 ^N-1 , the access network device can divide the 2 ^N data packets into 2 ^M segments, each segment using one MRB carry.

For example, assuming N is equal to 4 and M is equal to 2, then the first numerical value is equal to 4. As shown in Figure 13a, the MBS QFI SNs of the 16 packets of the first QoS flow range from 0 to 15. Among them, the MBS QFI SNs that can be divided by 4 after adding 1 are: 3, 7, 11, 15.

Therefore, as shown in Figure 13a, the access network device releases MRB#1 and establishes MRB#2 when the MBS QFI SN of the data packet is equal to 3; it releases MRB#2 and establishes MRB# when the MBS QFI SN of the data packet is equal to 7. 3; When the MBS QFI SN of the data packet is equal to 11, MRB#3 is released and MRB#4 is established; when the MBS QFI SN of the data packet is equal to 15, MRB#4 is released and MRB#5 is established. Among them, MRB#5 can be used to carry subsequent data packets of the first QoS flow.

It should be noted that in this application, the MRB is released when the MBS QFI SN (or COUNT value) of the data packet is equal to a certain value, which can be understood as: when the MRB QFI SN (or COUNT value) of the data packet is equal to the certain value , and after sending the data packet to the terminal device through the MRB, release the MRB. Or, it can be understood as: when the MBS QFI SN (or COUNT value) of the data packet is equal to a certain value, the access network device can release the MRB, but the specific release timing may need to be determined based on other conditions.

For example, data packets may arrive out of order between the core network device and the access network device. That is, the access network equipment may receive the data packet with the larger MBS QFI SN first, and then the data packet with the smaller MBS QFI SN. At this time, if the MBS QFI SN of a data packet received by the access network device meets the first condition (recorded as data packet #A), but the data packet before the data packet #A has not been received, the access network device The device can start a timer. Before the timer expires, if the access network device receives the data packet before the data packet #A, the access network device can send the data packet #A and the data packet before it to the terminal device, and then release the MRB. Before the timer expires, if the access network device does not receive the data packet before the data packet #A, the access network device can release the MRB after the timer expires.

Optionally, in the case where the first condition includes the above condition (2) and the first value satisfies the above formula (a), the scenario of releasing and establishing the MRB when the MBS QFI SN of the data packet is equal to 2 ^N -1 is included. Therefore, in this case, the access network device may not perform the above steps S1203-S1204.

Optionally, when the first condition includes the above condition (2) and the first value satisfies the above formula (a), for each MRB, the PDCP SN of the COUNT value of the data packet of the MRB is equal to the MBS QFI SN of the data packet. The value of the NK low-order bits. The HFN of the COUNT value of this packet satisfies the following formula:

Among them, MBS QFI SN represents the MBS QFI SN of the data packet, PDCP-SN-Size represents the length of the PDCP SN, and X represents the offset value. Indicates rounding down.

It's understandable, That is, the value of the K high-order bits of the MBS QFI SN of the data packet. It can also be understood as intercepting the first N-[PDCP-SN-Size] (ie, K) bits of the MBS QFI SN.

Optionally, when the PDCP SN of the COUNT value of the data packet is equal to the value of the N-K low-order bits of the MBS QFI SN of the data packet, and the HFN of the COUNT value of the data packet satisfies the above formula (f), the first The conditions include the above condition (2). The position of releasing the MRB determined when the first value satisfies the above formula (a) can also be determined by the following conditions:

When the COUNT value of the first data packet satisfies [2 ^KM -1+X, 2 ^NK -1], the first MRB is released and the second MRB is established.

For example, taking N equals 4, is 4 to 7. When the subsequent MBS QFI SNs of the data packets of the first QoS flow are 4 to 7, 8 to 11, or 12 to 15, the corresponding COUNT values are 4 to 7. ^Since [2 ^KM -1 + MRB.

Optionally, when the access network device releases the MRB when the COUNT value is equal to a certain value, the specific release timing can be determined based on the reception status of the terminal device. For example, when the COUNT value of a certain data packet meets the conditions for releasing the MRB, the access network device can send the data packet (recorded as data packet #B) to the terminal device.

The terminal device can report the COUNT value of the successfully received data packet to the access network device. When the successfully received COUNT value is equal to the COUNT value of data packet #B, the access network device releases the MRB. Alternatively, the terminal device can report RX_DELIV to the access network device. When the RX_DELIV is greater than or equal to the COUNT value of data packet #B, the access network device releases the MRB.

Optionally, the access network device can be configured to report the COUNT value or RX_DELIV condition of successfully received data packets to the terminal device. Reference may be made to the relevant description of the access network device releasing the first MRB in the method shown in Figure 9, which will not be described again here.

Optionally, when the first condition includes the above condition (2) and the first value is a preset value, 2 ^N data packets of the first QoS flow can be carried on multiple MRBs. Among them, the MBS QFI SN of the starting data packet among the 2 ^N data packets is 0, and the MBS QFI SN of the terminating data packet is 2 ^N-1 . The multiple MRBs can use the same or different configurations.

That is to say, for 2 ^N data packets with MBS QFI SN of the first QoS flow from 0 to 2 ^N-1 , the access network device can divide the 2 ^N data packets into multiple segments, and each segment is carried by one MRB.

Exemplarily, the first condition includes the above condition (2). For example, the first value is a preset value. Assume that N is equal to 4 and the first value is equal to 5. As shown in Figure 13c, the 16 data of the first QoS flow The MBS QFI SN of the package is 0 to 15. Among them, the MBS QFI SNs that can be divided evenly by 5 after adding 1 are: 4, 9, 14.

Therefore, as shown in Figure 13c, the access network device releases MRB#1 and establishes MRB#2 when the MBS QFI SN of the data packet is equal to 4; it releases MRB#2 and establishes MRB# when the MBS QFI SN of the data packet is equal to 9. 3; When the MBS QFI SN of the data packet is equal to 14, MRB#3 is released and MRB#4 is established.

Optionally, in the case where the first condition includes the above condition (2) and the first value is a preset value, the scenario in which the MRB is released and established when the MBS QFI SN of the data packet is equal to 2 ^N -1 may not be included. Therefore, in this case, the access network equipment can to perform the above steps S1203-S1204. For example, in the example shown in Figure 13c, the access network device releases MRB#4 when the MBS QFI SN is equal to 15, and establishes MRB#5. Among them, MRB#5 can be used to carry subsequent data packets of the first QoS flow.

Optionally, when the first condition includes the above condition (2) and the first value is a preset value, for each MRB, the HFN of the COUNT value of the data packet satisfies the following formula:

The PDCP SN of the COUNT value of the MRB packet satisfies the following formula:
PDCP SN＝[(MBS QFI SN)mod S ₁ ]mod(2 ^PDCP-SN-Size ) (h)

Among them, MBS QFI SN represents the MBS QFI SN of the data packet, PDCP-SN-Size represents the length of the PDCP SN, S ₁ represents the first value, and X represents the offset value. Indicates rounding down.

Optionally, when the HFN of the COUNT value of the data packet satisfies the above formula (g), and the PDCP SN of the COUNT value of the data packet satisfies the above formula (h), the first condition includes the above condition (2), the first The position where the MRB is released when the value is the preset value can also be determined by the following conditions:

When the HFN of the COUNT value of the first data packet satisfies the following formula (i) and the PDCP SN satisfies the following formula (j), the first MRB is released and the second MRB is established.

PDCP SN=(S ₁ -1)mod(2 ^PDCP-SN-Size ) (j)

For example, assume that N is equal to 4, the first value is equal to 5, X is equal to 1, and PDCP-SN-Size is equal to 2. As shown in Figure 13d, the MBS QFI SN of the data packet of the first QoS flow is 0 to 4. When the MBS QFI SN of the data packet in the first QoS flow is 5 to 9 and 10 to 14, the corresponding COUNT value is 4 to 8.

because When PDCP SN=(S ₁ -1)mod(2 ^PDCP-SN-Size )=0, the binary representation is 1000 and the decimal representation is 8. Therefore, the access network device releases and creates a new data packet when the COUNT value of the data packet is equal to 8. MRB.

Optionally, when the HFN of the COUNT value of the data packet satisfies formula (i) and the PDCP SN satisfies formula (j), the scenario in which the MRB is released and established when the MBS QFI SN of the data packet is equal to 2 ^N -1 may not be included. . Therefore, in this case, the access network device can perform the above steps S1203-S1204.

For example, assuming that the first condition includes the above condition (1) and the first value is a preset value, assuming that N is equal to 4 and the first value is equal to 4, then as shown in Figure 14, the 16 first QoS flows The MBS QFI SN of the packet is 0 to 15. Among them, the MBS QFI SNs that are greater than 0 and can be evenly divided by 4 are: 4, 8, 12.

Therefore, as shown in Figure 14, the access network device releases MRB#1 and establishes MRB#2 when the MBS QFI SN of the data packet is equal to 4; it releases MRB#2 and establishes MRB# when the MBS QFI SN of the data packet is equal to 8. 3; When the MBS QFI SN of the data packet is equal to 12, MRB#3 is released and MRB#4 is established.

Optionally, when the first condition includes the above condition (1) and the first value is a preset value, the scenario in which the MRB is released and established when the MBS QFI SN of the data packet is equal to 2 ^N -1 may not be included. Therefore, in this case, the access network device can perform the above steps S1203-S1204. For example, in the example shown in Figure 14, the access network device releases MRB#4 and establishes MRB#5 when the MBS QFI SN is equal to 15. Among them, MRB#5 can be used to carry subsequent data packets of the first QoS flow.

Optionally, when the first condition includes the above condition (3) and the first value satisfies the above formula (e), 2 ^N data packets of the first QoS flow can be carried on two MRBs. Among them, the MBS QFI SN of the starting data packet among the 2 ^N data packets is 0, and the MBS QFI SN of the terminating data packet is 2 ^N-1 . The two MRBs can use the same or different configurations.

For example, assuming that the first condition includes the above condition (3) and the first value satisfies the above formula (e), assuming that N is equal to 4, X is equal to 1, PDCP-SN-Size is equal to 2, then the first value is equal to 11 , as shown in Figure 15a, the MBS QFI SNs of the 16 packets of the first QoS flow are 0 to 15. The access network device releases MRB#1 and establishes MRB#2 when the MBS QFI SN of the data packet is equal to 11.

Optionally, when the first condition includes the above condition (3) and the first value satisfies the above formula (e), before the access network device performs the above step S1202, the HFN of the COUNT value of the data packet of the first MRB is equal to the data packet The sum of the K high-order bits of the MBS QFI SN and the offset value X, the PDCP SN of the COUNT value of the first MRB packet is equal to the N-K low-order bits of the MBS QFI SN of the data packet.

After the access network device performs the above step S1202, the minimum HFN of the COUNT value of the data packet of the second MRB may be equal to P ₁ and the maximum HFN may be equal to P ₁ +X-1. Among them, P ₁ is an integer greater than 1, and P ₁ +X is less than 2 ^K . That is, the minimum COUNT value of the data packet of the second MRB can be [P _1,0 ], and the maximum COUNT value can be [P ₁ +X-1,2 ^PDCP-SN-Size ].

Optionally, when the first condition includes the above condition (3) and the first value satisfies the above formula (e), the scenario in which the MRB is released and established when the MBS QFI SN of the data packet is equal to 2 ^N -1 may not be included. Therefore, in this case, the access network device can perform the above steps S1203-S1204. For example, in the example shown in Figure 15a, the access network device releases MRB#3 when the MBS QFI SN is equal to 15, and establishes MRB#3. Among them, MRB#3 can be used to carry subsequent data packets of the first QoS flow.

Optionally, for the first MRB, the HFN of the COUNT value of the data packet in the first MRB is equal to the sum of the K high-order bits of the MBS QFI SN of the data packet and the offset value X, and the PDCP SN of the COUNT value is equal to the data In the case of the value of the N-K low-order bits of the MBS QFI SN of the package, the first condition includes the above condition (3). The position of releasing the MRB determined when the first value satisfies the above formula (e) can also be determined by the following conditions :

When the COUNT value of the data packet of the first MRB is equal to 2 ^N -1, the first MRB is released and the second MRB is established.

For example, taking N equals 4, . Since 2 ^N -1=15, the access network device releases MRB#1 and establishes MRB#2 when the COUNT value of the data packet is equal to 15. When 2 ^N -1=15, the corresponding MBS QFI SN is equal to 11, that is, the corresponding positions of releasing MRB in Figure 15a and Figure 15b are the same.

Optionally, the minimum COUNT value of the data packet of the second MRB can be [P _1,0 ], and the maximum COUNT value can be [P ₁ +X-1,2 ^PDCP-SN-Size ]. For P ₁ , please refer to the above related information. illustrate. In Figure 15b, P ₁ and X are equal to 1 as an example for illustration.

Optionally, the scenario where the MRB is released and created when the COUNT value of the data packet is equal to 2 ^N -1 may not include the scenario where the MRB is released and created when the MBS QFI SN of the data packet is equal to 2 ^N -1. Therefore, in this case, the access network device can perform the above steps S1203-S1204.

Optionally, when the first condition includes the above condition (3) and the first value satisfies the above formula (c), 2 ^N data packets of the first QoS flow can be carried on two MRBs. Among them, the MBS QFI SN of the starting data packet among the 2 ^N data packets is 0, and the MBS QFI SN of the terminating data packet is 2 ^N-1 . The two MRBs can use the same or different configurations.

For example, assuming that the first condition includes the above condition (3) and the first value satisfies the above formula (c), assuming that N is equal to 4 and PDCP-SN-Size is equal to 2, then the first value is equal to 3, as shown in Figure 16a As shown, the MBS QFI SNs of the 16 packets of the first QoS flow are 0 to 15. The access network device releases MRB#1 when the MBS QFI SN of the data packet is equal to 3, and Create MRB#2.

Optionally, when the first condition includes the above condition (3) and the first value satisfies the above formula (c), before the access network device performs the above step S1202, the HFN of the COUNT value of the data packet of the first MRB is equal to the data packet The sum of the K high-order bits of the MBS QFI SN and the offset value X, the PDCP SN of the COUNT value of the first MRB packet is equal to the N-K low-order bits of the MBS QFI SN of the data packet. After the access network device performs the above step S1202, the COUNT value of the data packet of the second MRB may be equal to the MBS QFI SN of the data packet.

Optionally, when the first condition includes the above condition (3) and the first value satisfies the above formula (c), the scenario in which the MRB is released and established when the MBS QFI SN of the data packet is equal to 2 ^N -1 may not be included. Therefore, in this case, the access network device can perform the above steps S1203-S1204. For example, in the example shown in Figure 16a, the access network device releases MRB#2 and establishes MRB#3 when the MBS QFI SN is equal to 15. Among them, MRB#3 can be used to carry subsequent data packets of the first QoS flow.

Optionally, for the first MRB, the HFN of the COUNT value of the data packet in the first MRB is equal to the sum of the K high-order bits of the MBS QFI SN of the data packet and the offset value X, and the PDCP SN of the COUNT value is equal to the data In the case of the value of the N-K low-order bits of the MBS QFI SN of the package, the first condition includes the above condition (3). The position of releasing the MRB determined when the first value satisfies the above formula (c) can also be determined by the following conditions :

When the COUNT value of the first data packet is equal to [X,2 ^NK -1], the first MRB is released and the second MRB is established.

For example, taking N equals 4, . ^Since N equals 4, When equal to 7, MRB#1 is released and MRB#2 is established. When the COUNT value is equal to 7, the corresponding MBS QFI SN is equal to 3, that is, the positions corresponding to the release of MRB in Figure 16a and Figure 16b are the same.

Optionally, the COUNT value of the data packet of the second MRB can be equal to the MBS QFI SN of the data packet.

Optionally, when the COUNT value of the data packet is equal to [X, 2 ^NK -1], the MRB is released and created. This may not include the scenario where the MRB is released and created when the MBS QFI SN of the data packet is equal to 2 ^N -1. Therefore, in this case, the access network device can perform the above steps S1203-S1204.

Optionally, when the first condition includes the above condition (3) and the first value satisfies the above formula (d), 2 ^N data packets of the first QoS flow can be carried on two MRBs. Among them, the MBS QFI SN of the starting data packet among the 2 ^N data packets is 0, and the MBS QFI SN of the terminating data packet is 2 ^N-1 . The two MRBs can use the same or different configurations.

For example, assuming that the first condition includes the above condition (3) and the first value satisfies the above formula (d), assuming that N is equal to 4 and PDCP-SN-Size is equal to 3, then the first value is greater than or equal to 1, such as As shown in Figure 17a, the MBS QFI SNs of the 16 packets of the first QoS flow range from 0 to 15. The access network device releases MRB#1 and establishes MRB#2 when the MBS QFI SN of the data packet is equal to 1.

Optionally, when the first condition includes the above condition (3) and the first value satisfies the above formula (d), before the access network device performs the above step S1202, the HFN of the COUNT value of the data packet of the first MRB is equal to the data packet The sum of the K high-order bits of the MBS QFI SN and the offset value X, the PDCP SN of the COUNT value of the first MRB packet is equal to the N-K low-order bits of the MBS QFI SN of the data packet. After the access network device performs the above step S1202, the COUNT value of the data packet of the second MRB may be equal to the MBS QFI SN of the data packet.

Optionally, when the first condition includes the above condition (3) and the first value satisfies the above formula (d), the scenario in which the MRB is released and established when the MBS QFI SN of the data packet is equal to 2 ^N -1 may not be included. Therefore, in this case, the access network device can perform the above steps S1203-S1204. For example, in the example shown in Figure 17a, the access network device releases MRB#2 and establishes MRB#3 when the MBS QFI SN is equal to 15. Among them, MRB#3 can be used to carry the first QoS flow subsequent packets.

Optionally, for the first MRB, the HFN of the COUNT value of the data packet in the first MRB is equal to the sum of the K high-order bits of the MBS QFI SN of the data packet and the offset value X, and the PDCP SN of the COUNT value is equal to the data In the case of the value of the N-K low-order bits of the MBS QFI SN of the package, the first condition includes the above condition (3). The position of releasing the MRB determined when the first value satisfies the above formula (d) can also be determined by the following conditions :

When the COUNT value of the first data packet is equal to [X,0.5*2 ^PDCP-SN-Size -1], the first MRB is released and the second MRB is established.

For example, taking N equals 4, is 4 to 5. Since N is equal to 4 ^, The access network device releases MRB#1 and establishes MRB#2 when the COUNT value of the data packet is equal to 5. When the COUNT value is equal to 5, the corresponding MBS QFI SN is equal to 1, that is, the corresponding position of releasing the MRB in Figure 17a and Figure 17b is the same.

Optional, when the COUNT value of the data packet is equal to [X,0.5*2 ^PDCP-SN-Size -1] and a new MRB is released, it may not include the MBS QFI SN of the data packet and is released when it is equal to 2 ^N -1 And establish the MRB scenario. Therefore, in this case, the access network device can perform the above steps S1203-S1204.

It should be noted that the above-mentioned Figures 13a to 17b take a process in which the MBS QFI SN increases from 0 to 2 ^N -1 as an example, or one MBS QFI SN cycle as an example. In actual applications, during each round of increase of MBS QFI SN, the access network equipment can use the method shown in Figure 12 to release and create new MRBs.

It can be understood that the above embodiment takes the MBS service scenario as an example for description. Of course, the methods described in the embodiments of this application can also be appropriately modified to be applied to other scenarios, for example, to unicast service scenarios. At this time, the MBS QFI SN in this application can be replaced with the MBS QFI SN in the unicast service accordingly. QFI SN; Alternatively, it can be applied to determine parameter B based on parameter A. If parameter A reaches the upper limit before parameter B, parameter B may overflow.

It can be understood that in the above embodiments, the methods and/or steps implemented by the access network equipment can also be implemented by components (such as processors, chips, chip systems, circuits, and logic modules) that can be used in the access network equipment. , or software such as chips or circuits); the methods and/or steps implemented by the core network equipment may also have components that can be used in the core network equipment (such as processors, chips, chip systems, circuits, logic modules, or software Such as chip or circuit) implementation.

The above mainly introduces the solutions provided by this application. Correspondingly, this application also provides a communication device, which is used to implement the various methods mentioned above. The communication device may be the access network equipment in the above method embodiment, or a device including the above access network equipment, or a component that can be used in the access network equipment, such as a chip or a chip system; or, the communication device may be The core network equipment in the above method embodiment is either a device including the above core network equipment, or a component that can be used in the core network equipment, such as a chip or a chip system.

It can be understood that, in order to implement the above functions, the communication device includes corresponding hardware structures and/or software modules for performing each function. Persons skilled in the art should easily realize that, with the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is performed by hardware or computer software driving the hardware depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each specific application, but such implementations should not be considered beyond the scope of this application.

Embodiments of the present application can divide the communication device into functional modules according to the above method embodiments. For example, functional modules can be divided into corresponding functional modules, or two or more functions can be integrated into one processing module. The above integrated modules can be implemented in the form of hardware or software function modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical function division. In actual implementation, it can be There are other ways to divide.

Optionally, taking the communication device as the access network device in the above method embodiment as an example, FIG. 18 shows a schematic structural diagram of an access network device 180. The access network device 180 includes a processing module 1801 and a transceiver module 1802.

In some embodiments, the access network device 180 may also include a storage module (not shown in Figure 18) for storing program instructions and data.

In some embodiments, the transceiver module 1802, which may also be called a transceiver unit, is used to implement sending and/or receiving functions. The transceiver module 1802 may be composed of a transceiver circuit, a transceiver, a transceiver or a communication interface.

In some embodiments, the transceiver module 1802 may include a receiving module and a transmitting module, respectively configured to perform the receiving and transmitting steps performed by the access network device in the above method embodiments, and/or to support the steps described herein. Other processes of the technology; the processing module 1801 can be used to perform steps of the processing class (such as determination, generation, etc.) performed by the access network device in the above method embodiments, and/or to support the technology described herein. Other processes.

As a possible implementation:

The transceiver module 1802 is configured to receive the first data packet from the core network device. The first data packet is the data packet of the first quality of service QoS flow of the multicast broadcast service MBS service, and the MBS quality of service flow identification sequence of the first data packet. No. QFI SN is less than the first threshold;

The transceiver module 1802 is also used to send first indication information to the core network device. The first indication information is used by the core network device to set the MBS QFI SN of the second data packet of the first QoS flow. The MBS QFI SN of the second data packet is greater than Or equal to 0, and less than the MBS QFI SN of the first data packet, and the second data packet is the data packet after the first data packet.

Optionally, the processing module 1801 is used to generate the first indication information.

As another possible implementation:

Processing module 1801, generates second indication information;

The transceiver module 1802 is configured to send second instruction information to the core network device. The second instruction information is used by the core network device to release the first MBS session of the multicast broadcast service MBS service and establish the second MBS session of the MBS service; or, The second instruction information is used by the core network device to delete the first quality of service QoS flow of the first MBS session and add the second QoS flow to the first MBS session.

As yet another possible implementation:

The processing module 1801 is configured to generate third indication information, and the third indication information indicates the maximum value and/or the minimum value of the multicast broadcast service MBS quality of service flow identification sequence number QFI SN;

The transceiver module 1802 is configured to send the third indication information to the core network device.

As yet another possible implementation:

The transceiver module 1802 is configured to receive the first data packet from the core network device, where the first data packet is the data packet of the first quality of service QoS flow of the multicast broadcast service MBS;

The processing module 1801 is configured to release the first MBS radio bearer MRB associated with the first QoS when the MBS quality of service flow identification sequence number QFI SN of the first data packet meets the first condition, and establish the second MRB associated with the first QoS flow. MRB, the first data packet is carried in the first MRB.

All relevant content of each step involved in the above method embodiments can be quoted from the functional description of the corresponding functional module, and will not be described again here.

In this application, the access network device 180 is presented in the form of dividing various functional modules in an integrated manner. A "module" here may refer to an application-specific integrated circuit (ASIC), a circuit, a processor and memory that executes one or more software or firmware programs, an integrated logic circuit, and/or others that may provide the above functions. device.

In some embodiments, in terms of hardware implementation, those skilled in the art can imagine that the access network device 180 may take the form of the communication device 300 shown in FIG. 3 .

As an example, the function/implementation process of the processing module 1801 in Figure 18 can be implemented by the processor 301 in the communication device 300 shown in Figure 3 calling the computer execution instructions stored in the memory 303. The function/implementation process of the transceiver module 1802 in Figure 18 can be implemented through the communication interface 304 in the communication device 300 shown in Figure 3 .

In some embodiments, when the access network device 180 in Figure 18 is a chip or chip system, the function/implementation process of the transceiver module 1802 can be implemented through the input and output interface (or communication interface) of the chip or chip system, and the processing module The function/implementation process of 1801 can be realized through the processor (or processing circuit) of the chip or chip system.

Since the access network device 180 provided in this embodiment can perform the above method, the technical effects it can obtain can be referred to the above method embodiment, which will not be described again here.

Optionally, taking the communication device as the core network device in the above method embodiment as an example, FIG. 19 shows a schematic structural diagram of a core network device 190. The core network device 190 includes a processing module 1901 and a transceiver module 1902.

In some embodiments, the core network device 190 may also include a storage module (not shown in Figure 19) for storing program instructions and data.

In some embodiments, the transceiver module 1902, which may also be called a transceiver unit, is used to implement sending and/or receiving functions. The transceiver module 1902 may be composed of a transceiver circuit, a transceiver, a transceiver or a communication interface.

In some embodiments, the transceiver module 1902 may include a receiving module and a sending module, respectively configured to perform the receiving and sending steps performed by the core network device in the above method embodiments, and/or to support the steps described herein. Other processes of the technology; the processing module 1901 can be used to perform steps of the processing class (such as determination, generation, etc.) performed by the core network device in the above method embodiments, and/or other processes used to support the technology described herein .

As a possible implementation:

The transceiver module 1902 is configured to send a first data packet to the access network device. The first data packet is a data packet of the first quality of service QoS flow of the multicast broadcast service MBS, and the MBS quality of service flow identification sequence number of the first data packet QFI SN is less than the first threshold;

The transceiver module 1902 is also used to receive the first indication information from the access network device;

The processing module 1901 is configured to set the MBS QFI SN of the second data packet of the first QoS flow according to the first indication information. The MBS QFI SN of the second data packet is greater than or equal to 0 and less than the MBS QFI SN of the first data packet. The second data packet is the data packet after the first data packet.

As another possible implementation:

The transceiver module 1902 is configured to receive the second instruction information from the access network device; the processing module 1901 is configured to release the first MBS session of the multicast broadcast service MBS service according to the second instruction information, and establish the second MBS session of the MBS service ; Alternatively, the processing module 1901 is configured to delete the first quality of service QoS flow of the first MBS session according to the second indication information, and add the second QoS flow to the first MBS session.

As yet another possible implementation:

The processing module 1901 is used to obtain the maximum value and/or the minimum value of the multicast broadcast service MBS quality of service flow identification sequence number QFI SN. The maximum value is less than 2 ^N -1, the minimum value is greater than 0, and N is the MBS QFI SN. Length; the transceiver module 1902 is used to send the first data packet. The MBS QFI SN of the first data packet is less than or equal to the maximum value, and/or is greater than or equal to the minimum value. The first data packet is the first quality of service of the MBS service. QoS flow packets.

As yet another possible implementation:

The processing module 1901 is used to obtain the maximum value and/or the minimum value of the multicast broadcast service MBS quality of service flow identification sequence number QFI SN. The maximum value is less than 2 ^N -1, the minimum value is greater than 0, and N is the MBS QFI SN. Length; transceiver module 1902, Used to send a first data packet and a second data packet, the first data packet is a data packet of the first quality of service QoS flow of the MBS service, and the second data packet is a data packet of the second QoS flow of the MBS service. Where: the sum of the MBS QFI SN of the first data packet and the MBS QFI SN of the second data packet is less than or equal to the maximum value; and/or, the sum of the MBS QFI SN of the first data packet and the MBS QFI SN of the second data packet Greater than or equal to the minimum value, the first QoS flow and the second QoS flow are associated with an MBS radio bearer MRB.

Optionally, the processing module 1901 is used to obtain the maximum value and/or the minimum value of the MBS QFI SN, including: the processing module 1901 is used to obtain the maximum value of the MBS QFI SN according to the third instruction information received by the transceiver module 1902. , and/or, minimum value.

In this application, the core network device 190 is presented in the form of dividing various functional modules in an integrated manner. "Module" here may refer to ASICs, circuits, processors and memories that execute one or more software or firmware programs, integrated logic circuits, and/or other devices that can provide the above functions.

In some embodiments, in terms of hardware implementation, those skilled in the art can imagine that the core network device 190 may take the form of the communication device 300 shown in FIG. 3 . As an example, the function/implementation process of the processing module 1901 in Figure 19 can be implemented by the processor 301 in the communication device 300 shown in Figure 3 calling the computer execution instructions stored in the memory 303. The function/implementation process of the transceiver module 1902 in Figure 19 can be implemented through the communication interface 304 in the communication device 300 shown in Figure 3 .

In some embodiments, when the core network device 190 in Figure 19 is a chip or chip system, the function/implementation process of the transceiver module 1902 can be implemented through the input and output interface (or communication interface) of the chip or chip system, and the processing module 1901 The function/implementation process can be realized by the processor (or processing circuit) of the chip or chip system.

Since the core network device 190 provided in this embodiment can perform the above method, the technical effects it can obtain can be referred to the above method embodiment, which will not be described again here.

As a possible product form, the access network equipment or core network equipment described in the embodiments of this application can also be implemented using the following: one or more field programmable gate arrays (FPGA), Programmable logic device (PLD), controller, state machine, gate logic, discrete hardware components, any other suitable circuit, or any combination of circuits capable of performing the various functions described throughout this application.

In some embodiments, embodiments of the present application further provide a communication device, which includes a processor and is configured to implement the method in any of the above method embodiments.

As a possible implementation manner, the communication device further includes a memory. This memory is used to store necessary computer programs and data. The computer program may include instructions, and the processor may call the instructions in the computer program stored in the memory to instruct the communication device to perform the method in any of the above method embodiments. Of course, the memory may not be in the communication device.

As another possible implementation, the communication device further includes an interface circuit, which is a code/data reading and writing interface circuit. The interface circuit is used to receive computer execution instructions (computer execution instructions are stored in the memory and may be directly read from memory, or possibly through other devices) and transferred to the processor.

As yet another possible implementation manner, the communication device further includes a communication interface, which is used to communicate with modules external to the communication device.

It can be understood that the communication device may be a chip or a chip system. When the communication device is a chip system, it may be composed of a chip or may include a chip and other discrete devices. This is not specifically limited in the embodiments of the present application.

This application also provides a computer-readable storage medium on which computer programs or instructions are stored. The computer program When the program or instructions are executed by the computer, the functions of any of the above method embodiments are implemented.

This application also provides a computer program product, which implements the functions of any of the above method embodiments when executed by a computer.

Those of ordinary skill in the art can understand that for the convenience and simplicity of description, the specific working processes of the systems, devices and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be described again here.

It can be understood that the systems, devices and methods described in this application can also be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or can be integrated into another system, or some features can be ignored, or not implemented. On the other hand, the coupling or direct coupling or communication connection between each other shown or discussed may be through some interfaces, and the indirect coupling or communication connection of the devices or units may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separate, that is, they may be located in one place, or they may be distributed to multiple network units. Components shown as units may or may not be physical units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment. In addition, each functional unit in each embodiment of the present application can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using a software program, it may 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 computer program instructions are loaded and executed on a computer, all or part of the processes (or functions) described in the embodiments of this application are implemented. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transferred from a website, computer, server, or data center Transmission to another website, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that can be accessed by a computer or include one or more data storage devices such as servers and data centers that can be integrated with the medium. The available media may be magnetic media (eg, floppy disk, hard disk, magnetic tape), optical media (eg, DVD), or semiconductor media (eg, solid state disk (SSD)), etc. In the embodiment of the present application, the computer may include the aforementioned device.

Although the present application has been described herein in connection with various embodiments, in practicing the claimed application, those skilled in the art will understand and understand by reviewing the drawings, the disclosure, and the appended claims. Other variations of the disclosed embodiments are implemented. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality. A single processor or other unit may perform several of the functions recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not mean that a combination of these measures cannot be combined to advantageous effects.

Although the present application has been described in conjunction with specific features and embodiments thereof, it will be apparent that various modifications and combinations may be made without departing from the spirit and scope of the application. Accordingly, the specification and drawings are intended to be merely illustrative of the application as defined by the appended claims and are to be construed to cover any and all modifications, variations, combinations or equivalents within the scope of the application. Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. In this way, if these modifications and variations of the present application fall within the scope of the claims of the present application and equivalent technologies, the present application is also intended to include these modifications and variations.

Claims

A communication method, characterized in that the method includes:

Send a first data packet to the access network device, the first data packet is a data packet of the first quality of service QoS flow of the multicast broadcast service MBS, and the MBS quality of service flow identification sequence number QFI SN of the first data packet less than the first threshold;

Receive first indication information from the access network device;

The MBS QFI SN of the second data packet of the first QoS flow is set according to the first indication information. The MBS QFI SN of the second data packet is greater than or equal to 0 and less than the MBS QFI SN of the first data packet. SN, the second data packet is the data packet after the first data packet.
A communication method, characterized in that the method includes:

Receive the first data packet from the core network device, the first data packet is the data packet of the first quality of service QoS flow of the multicast broadcast service MBS service, and the MBS quality of service flow identification sequence number QFI of the first data packet SN is less than the first threshold;

Send first indication information to the core network device, the first indication information is used for the core network device to set the MBS QFI SN of the second data packet of the first QoS flow, and the MBS QFI SN of the second data packet QFI SN is greater than or equal to 0 and less than the MBS QFI SN of the first data packet, and the second data packet is the data packet after the first data packet.
The method according to claim 1 or 2, characterized in that the first indication information includes at least one of the following:

Information indicating that the maximum COUNT value of data packets of the first MBS radio bearer MRB is equal to the second threshold, wherein the first MRB is the MRB associated with the first QoS flow;

Information indicating that the difference between the maximum COUNT value of the data packet of the first MRB and the second threshold is less than or equal to M1, where M1 is a positive integer;

Information indicating the difference between the maximum COUNT value of the data packet of the first MRB and the second threshold;

The status information of the first MRB;

Information indicating that the maximum MBS QFI SN of the first QoS flow is equal to the third threshold;

Information indicating that the difference between the maximum MBS QFI SN of the first QoS flow and the third threshold is less than or equal to M2, where M2 is a positive integer; or,

Information indicating a difference between the maximum MBS QFI SN of the first QoS flow and the third threshold.
The method of claim 3, wherein the first indication information further includes at least one of the following: an identifier of the first MRB, an identifier of the first QoS flow, or an identifier of the MBS service .
The method according to any one of claims 1 to 4, characterized in that the second data packet is a data packet after the first data packet, including:

The second data packet is the M3th data packet after the first data packet, M3 is less than or equal to M1+1, and M1 is the maximum difference between the maximum COUNT value of the data packet of the first MRB and the second threshold. value, the first MRB is the MRB associated with the first QoS flow; or,

M3 is less than or equal to M2+1, and M2 is the maximum difference between the maximum MBS QFI SN of the first QoS flow and the third threshold.
A communication method, characterized in that the method includes:

Receive second indication information from the access network device;

Release the first MBS session of the multicast broadcast service MBS service according to the second instruction information, and establish the second MBS session of the MBS service; or,

Delete the first quality of service QoS flow of the first MBS session according to the second indication information, and perform the Add a second QoS flow to the MBS session.
A communication method, characterized in that the method includes:

Generate second instruction information;

Send the second instruction information to the core network device, where the second instruction information is used by the core network device to release the first MBS session of the multicast broadcast service MBS service and establish the second MBS session of the MBS service; or,

The second instruction information is used by the core network device to delete the first quality of service QoS flow of the first MBS session and add a second QoS flow to the first MBS session.
The method according to claim 6 or 7, characterized in that the second indication information includes at least one of the following:

Information indicating that the maximum COUNT value of data packets of the first MBS radio bearer MRB is equal to the second threshold, wherein the first MRB is the MRB associated with the first QoS flow;

Information indicating that the difference between the maximum COUNT value of the data packet of the first MRB and the second threshold is less than or equal to M1, where M1 is a positive integer;

Information indicating the difference between the maximum COUNT value of the data packet of the first MRB and the second threshold;

The status information of the first MRB;

Information indicating that the maximum MBS QFI SN of the first QoS flow is equal to the third threshold;

Information indicating that the difference between the maximum MBS QFI SN of the first QoS flow and the third threshold is less than or equal to M2, where M2 is a positive integer; or,

Information indicating a difference between the maximum MBS QFI SN of the first QoS flow and the third threshold.
A communication method, characterized in that the method includes:

Generate third indication information, the third indication information indicates the maximum value and/or the minimum value of the multicast broadcast service MBS quality of service flow identification sequence number QFI SN;

Send the third indication information to the core network device.
The method according to claim 9, wherein the maximum value is less than 2 N -1, the minimum value is greater than 0, and N is the length of the MBS QFI SN.
A communication method, characterized in that the method includes:

Obtain the maximum value and/or minimum value of the multicast broadcast service MBS quality of service flow identification sequence number QFI SN. The maximum value is less than 2 N -1, the minimum value is greater than 0, and N is the MBS QFI SN. length;

Send a first data packet, the MBS QFI SN of the first data packet is less than or equal to the maximum value, and/or, greater than or equal to the minimum value, and the first data packet is the first quality of service of the MBS service QoS flow packets.
A communication method, characterized in that the method includes:

Obtain the maximum value and/or minimum value of the multicast broadcast service MBS quality of service flow identification sequence number QFI SN. The maximum value is less than 2 N -1, the minimum value is greater than 0, and N is the MBS QFI SN. length;

Send a first data packet and a second data packet, the first data packet is a data packet of the first quality of service QoS flow of the MBS service, and the second data packet is a data packet of the second QoS flow of the MBS service ,

in:

The sum of the MBS QFI SN of the first data packet and the MBS QFI SN of the second data packet is less than or equal to the maximum value; and/or,

The sum of the MBS QFI SN of the first data packet and the MBS QFI SN of the second data packet is greater than or equal to the minimum value, and the first QoS flow and the second QoS flow are associated with an MBS wireless bearer MRB. .
The method according to claim 11 or 12, characterized in that: obtaining the maximum value of MBS QFI SN, and/or, minimum value, including:

Receive third indication information from the access network device;

Obtain the maximum value of the MBS QFI SN and/or the minimum value according to the third indication information.
The method according to any one of claims 9-13, characterized in that the maximum value of the MBS QFI SN is based on the length N of the MBS QFI SN, the length of the packet data convergence protocol sequence number PDCP SN, or the bias At least one of the transfer values is determined; or,

The minimum value of the MBS QFI SN is determined based on at least one of the length N of the MBS QFI SN, the length of the PDCP SN, or the offset value;

The offset value is used to determine the superframe number HFN of the COUNT value of the data packet.
The method according to claim 14, characterized in that the maximum value of the MBS QFI SN satisfies the following formula:
MBS QFI SN max =2 N -Y

Wherein, MBS QFI SN max represents the maximum value of the MBS QFI SN, and Y is an integer greater than 1.
The method according to claim 15, characterized in that said Y satisfies the following formula:
Y≥X*2 [PDCP-SN-Size] +Q 1

Wherein, X represents the offset value, * represents the multiplication operation, PDCP-SN-Size represents the length of the PDCP SN, and Q 1 is an integer greater than or equal to 1.
The method according to any one of claims 14 to 16, characterized in that the minimum value of the MBS QFI SN and the length of the PDCP SN satisfy one of the following formulas:
MBS QFI SN min =2 [PDCP-SN-Size] ;
MBS QFI SN min =X*2 [PDCP-SN-Size] +Q 2 ; or,
MBS QFI SN min =0.5*2 [PDCP-SN-Size]-1

Among them, MBS QFI SN min represents the minimum value of the MBS QFI SN, PDCP-SN-Size represents the length of the PDCP SN, X represents the offset value, * represents multiplication, and Q 2 is greater than or equal to 0. integer.
The method according to any one of claims 14-17, characterized in that when the third indication information indicates the maximum value of the MBS QFI SN, the HFN of the COUNT value of the data packet is equal to the HFN of the data packet. The sum of the value of the K high-order bits of MBS QFI SN and the offset value, K is the length of HFN.
The method according to any one of claims 14-17, characterized in that when the third indication information indicates the minimum value of the MBS QFI SN, the COUNT value of the data packet is equal to the MBS QFI of the data packet. SN.
The method according to any one of claims 14 to 17, characterized in that when the third indication information indicates the maximum value and minimum value of the MBS QFI SN,

The HFN of the COUNT value of the data packet is equal to the sum of the value of the K high-order bits of the MBS QFI SN of the data packet and the offset value, where K is the length of the HFN; or,

The COUNT value of the packet is equal to the MBS QFI SN of the packet.
A communication method, characterized in that the method includes:

Receive a first data packet from the core network device, where the first data packet is a data packet of the first quality of service QoS flow of the multicast broadcast service MBS;

When the MBS quality of service flow identification sequence number QFI SN of the first data packet meets the first condition, release the first MBS radio bearer MRB associated with the first QoS flow, and establish the second MRB associated with the first QoS flow. , the first data packet is carried in the first MRB.
The method according to claim 21, characterized in that the first condition is related to a first numerical value;

Wherein, the first value is determined based on the length of the MBS QFI SN, and/or the length of the packet data convergence protocol sequence number PDCP SN; or,

The first value is a preset value.
The method according to claim 22, characterized in that the first condition includes:

The MBS QFI SN of the first data packet is greater than 0 and is evenly divided by the first value; or,

The MBS QFI SN of the first data packet is divided by 1 as the first value; or,

The MBS QFI SN of the first data packet is equal to the first value.
The method according to claim 22 or 23, characterized in that the first numerical value satisfies one of the following formulas:
S 1 = 2NM
S 1 =2 NM -1;
S 1 =2 PDCP-SN-Size -1;
S 1 ≥0.5*2 [PDCP-SN-Size]-1 -1; or,
S 1 ＝2 N -X*2 PDCP-SN-Size -1

Wherein, S 1 represents the first numerical value, N represents the length of the MBS QFI SN, M is a positive integer, PDCP-SN-Size represents the length of the PDCP SN, * represents the multiplication operation, and X represents the offset value, The offset value is used to determine the superframe number HFN of the COUNT value of the data packet.
The method according to claim 24, characterized in that 2 N data packets of the first QoS flow are carried in 2 M MRBs, wherein the MBS QFI of the starting data packet in the 2 N data packets is The SN is 0 and the MBS QFI SN of the terminated packet is 2 N-1 .
The method according to any one of claims 21-25, characterized in that the method further includes:

Receive a second data packet from the core network device, where the second data packet is a data packet of the first QoS flow;

When the MBS QFI SN of the second data packet is equal to 2 N -1, the third MRB associated with the first QoS flow is released, and the fourth MRB associated with the first QoS flow is established. The second data packet carries on the third MRB.
A communication device, characterized in that the communication device includes a processor; the processor is used to run a computer program or instructions, so that the communication device executes claims 1, 3-5, 6, 8, The communication method according to any one of 11-20, wherein claims 3-5 refer to claim 1, claim 8 refers to claim 6, and claims 13-20 refer to claim 11 or 12.
A communication device, characterized in that the communication device includes a processor; the processor is used to run a computer program or instructions, so that the communication device executes claims 2, 3-5, 7-8, The communication method according to any one of 9-10, 14-20, and 21-26, wherein claims 3-5 refer to claim 2, claim 8 refers to claim 7, and claims 14-20 refer to claim 9.
A computer-readable storage medium, characterized in that the computer-readable storage medium stores computer instructions or programs, and when the computer instructions or programs are run on the computer, the results as claimed in claims 1, 3-5, 6, 8, 11 The communication method according to any one of -20 is implemented, wherein claims 3-5 refer to claim 1, claim 8 refers to claim 6, and claims 13-20 refer to claim 11 or 12.
A computer-readable storage medium, characterized in that the computer-readable storage medium stores computer instructions or programs, and when the computer instructions or programs are run on the computer, the results as claimed in claims 2, 3-5, 7-8, 9 -The communication method described in any one of 10, 14-20, and 21-26 is executed, wherein claims 3-5 cite claim 2, claim 8 cites claim 7, and claims 14-20 cite claim 9. .
A computer program product, characterized in that the computer program product includes computer instructions; when part Or when all the computer instructions are run on the computer, the communication method as described in any one of claims 1, 3-5, 6, 8, 11-20 is executed, wherein claims 3-5 refer to the claims 1. Claim 8 refers to claim 6, and claims 13-20 refer to claim 11 or 12.
A computer program product, characterized in that the computer program product includes computer instructions; when part or all of the computer instructions are run on a computer, the results as claimed in claims 2, 3-5, 7-8, 9-10 The communication method described in any one of , 14-20, and 21-26 is executed, wherein claims 3-5 cite claim 2, claim 8 cites claim 7, and claims 14-20 cite claim 9.
A communication system, characterized in that the communication system includes the communication device according to claim 27 and the communication device according to claim 28.