Communication method and communication device

Abstract

According to the communication method and the communication device, an application function network element provides information for synchronous transmission of multi-mode service flows, and a user plane function network element identifies associated PDU Sets among the multi-mode service flows based on the information and adds association information to GTP-U of the associated PDU Sets, so that access network equipment can determine the associated PDU Sets, and the GTP-U of the associated PDU Sets can be transmitted to the multi-mode service flows. Or the access network equipment identifies the associated PDU Set among the multi-mode service flows according to the information provided by the application function network element, and further performs synchronous transmission on the associated PDU Set. Therefore, the synchronous transmission guarantee of the multi-mode service flow can be realized.

Description

Technical Field

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

[0002] Multimodal services generally refer to services that include multiple modal service flows. Exemplarily, multimodal service flows can be service flows of different modalities such as audio streams, video streams, tactile streams, temperature streams, and / or brightness streams. For example, common multimedia services can include audio streams, video streams, and / or control data, etc. To provide a good and consistent service experience, synchronous transmission guarantee is required between multiple service flows of multimodal services.

[0003] Therefore, how to perform synchronous transmission guarantee between multiple service flows of multimodal services has become an urgent problem to be solved. Summary of the Invention

[0004] This application provides a communication method and a communication device, aiming to achieve synchronous transmission guarantee for multiple service flows of multimodal services.

[0005] In a first aspect, a communication method is provided. The method can be executed by an access network device. Without special instructions, the "access network device" can refer to the access network device itself, or a device that can support the access network device to implement its functions. For the convenience of description, the access network device is uniformly used hereinafter to describe.

[0006] The method includes: the access network device obtains first indication information, where the first indication information is used to indicate that a first service flow is associated with a second service flow; the access network device receives a first protocol data unit set (PDU Set) of the first service flow and a second PDU Set of the second service flow, where the first PDU Set and / or the second PDU Set carry association information, and the association information is used for the access network device to determine that the first PDU Set is associated with the second PDU Set; the access network device synchronously transmits the first PDU Set and the second PDU Set according to the first indication information and the association information.

[0007] Based on the above method, the access network device can determine that the first PDU Set of the first service flow is associated with the second PDU Set of the second service flow according to the first indication information and the association information carried by the first PDU Set and / or the second PDU Set, and then synchronously transmit the associated PDU Sets, so as to achieve synchronous transmission guarantee for multiple service flows.

[0008] In combination with the first aspect, in some implementations, the method further includes: the access network device obtains second indication information, where the second indication information is used to indicate the synchronization requirement between the first traffic flow and the second traffic flow; the access network device synchronously transmits the first PDU Set and the second PDU Set according to the first indication information and the association information, including: the access network device synchronously transmits the first PDU Set and the second PDU Set according to the first indication information, the association information, and the second indication information.

[0009] Optionally, the above synchronization requirement comes from the core network side, such as an application function network element, a session management function network element, or a policy control function network element.

[0010] Based on the above implementation, the access network device can transmit the associated PDU Sets in the first traffic flow and the second traffic flow according to the synchronization requirement between the first traffic flow and the second traffic flow, which helps to achieve the synchronous transmission guarantee of multiple traffic flows.

[0011] In combination with the first aspect or any of its implementations, in some other implementations, the synchronization requirement includes the maximum value of the transmission delay difference between the associated PDU Sets between the first traffic flow and the second traffic flow. Or the synchronization requirement includes the overall transmission delay requirement between the associated PDU Sets between the first traffic flow and the second traffic flow, such as the delay budget requirement from the start of receiving the first data packet of any associated PDU Set to the sending out of all associated PDUSets.

[0012] Based on the above implementation, the access network device can transmit the associated PDU Sets in the first traffic flow and the second traffic flow according to the maximum value of the transmission delay difference between the associated PDU Sets between the first traffic flow and the second traffic flow or the overall transmission delay requirement between the associated PDU Sets between the first traffic flow and the second traffic flow, which helps to achieve the synchronous transmission guarantee of multiple traffic flows.

[0013] In combination with the first aspect or any of its implementations, in some other implementations, the access network device synchronously transmits the first PDU Set and the second PDU Set according to the first indication information and the association information, including: the access network device determines the association between the first traffic flow and the second traffic flow according to the first indication information; the access network device determines the association between the first PDU Set and the second PDU Set according to the association information; the access network device synchronously transmits the associated first PDU Set and second PDU Set.

[0014] In combination with the first aspect or any implementation thereof, in some other implementations, the first PDU Set and / or the second PDU Set carry association information, including: the first PDU Set carries first association information, and the second PDU Set carries second association information; the access network device determines that the first PDU Set and the second PDU Set are associated according to the association information, including: when the first association information and the second association information are the same, the difference between the first association information and the second association information is within a threshold range, or the difference between the first association information and the second association information is less than or equal to the threshold, the access network device determines that the first PDU Set and the second PDU Set are associated.

[0015] Based on the above implementation, the access network device can determine the associated PDU Sets in multiple traffic flows, and then perform synchronous transmission on the associated PDU Sets, thereby realizing the synchronous transmission guarantee of multiple traffic flows.

[0016] In combination with the first aspect or any implementation thereof, in some other implementations, the threshold comes from the core network side, such as an application function network element, a session management function network element, a policy control function network element, or a user plane function network element.

[0017] In combination with the first aspect or any implementation thereof, in some other implementations, the association information is used to indicate the offset value between the identification information of the associated PDU Sets between the first traffic flow and the second traffic flow; the first PDU Set also carries first identification information, and the second PDU Set also carries second identification information; the access network device determines that the first PDU Set and the second PDU Set are associated according to the association information, including: when the difference between the first identification information and the second identification information is equal to the offset value, the access network device determines that the first PDU Set and the second PDU Set are associated.

[0018] Based on the above implementation, the access network device can receive the offset value between the identification information of the associated PDU Sets between the first traffic flow and the second traffic flow through the user plane. Compared with pre-configuring the offset value in advance through the control plane, the obtained offset value can better conform to the current traffic flow, which helps to realize the synchronous transmission guarantee of multiple traffic flows. That is, the association information is sent to the access network device through the user plane.

[0019] In combination with the first aspect or any of its implementations, in some other implementations, the first PDU Set carries the association information, and the second PDU Set does not carry the association information. The association information includes the identifier of the second traffic flow and the offset value, that is, the access network device can find the second PDU Set associated with this PDU Set in the second traffic flow according to the identifier of the second traffic flow and the offset value carried in the first PDU Set; or, the first PDU Set does not carry the association information, and the second PDU Set carries the association information. The association information includes the identifier of the first traffic flow and the offset value, that is, the access network device can find the first PDU Set associated with this PDU Set in the first traffic flow according to the identifier of the first traffic flow and the offset value carried in the second PDU Set; or, the first PDU Set and / or the second PDU Set carry the association information, including: the first PDU Set carries the first association information, and the second PDU Set carries the second association information. The first association information includes the identifier of the reference traffic flow and the first offset value, and the first offset value is the offset value between the identification information of the PDU Sets associated between the first traffic flow and the reference traffic flow. The second association information includes the identifier of the reference traffic flow and the second offset value, and the second offset value is the offset value between the identification information of the PDU Sets associated between the second traffic flow and the reference traffic flow; or, the first PDU Set and / or the second PDU Set carry the association information, including: the first PDU Set carries the first association information, and the second PDU Set carries the second association information. The first association information includes the identifier of the second traffic flow and the offset value, and the second association information includes the identifier of the first traffic flow and the offset value; or, the first PDU Set and / or the second PDU Set carry the association information, including: the first PDU Set carries the first association information, and the second PDU Set carries the second association information. The first association information includes the first identification information, and the second association information includes the first identification information, so that the access network device determines that the first PDU Set is associated with the second PDU Set based on the same first identification information carried in the associated first traffic flow and second traffic flow, and synchronously transmits the associated first PDU Set and second PDU Set.

[0020] In combination with the first aspect or any implementation thereof, in some other implementations, the first identification information is the sequence number (SN) of the first PDU Set, and the second identification information is the second PDU Set SN; or, the first identification information is the first timestamp, and the second identification information is the second timestamp; or the first identification information is the first PDU Set synchronization sequence identifier, and the second identification information is the second PDU Set synchronization sequence identifier, where the first PDU Set synchronization sequence identifier and the second PDU Set synchronization sequence identifier are used to identify the corresponding order information of the first PDU Set and the second PDU Set and are the same. Exemplarily, the first PDU Set sequence identifier and the second PDU Set sequence identifier may be the first PDU Set sequence number and the second PDU Set sequence number.

[0021] In combination with the first aspect or any implementation thereof, in some other implementations, the method further includes: the access network device receives, through control plane signaling, an offset value between the associated PDU Sets of the first traffic flow and the second traffic flow from the user plane function network element or the application function network element; the first PDU Set and / or the second PDU Set carry association information, including: the first PDU Set carries first association information, and the second PDU Set carries second association information; the access network device determines that the first PDU Set and the second PDU Set are associated according to the association information, including: when the difference between the first association information and the second association information is equal to the offset value, the access network device determines that the first PDU Set and the second PDU Set are associated.

[0022] Based on the above implementation, the access network device can receive, through the control plane, the offset value between the identification information of the associated PDU Sets of the first traffic flow and the second traffic flow. Compared with obtaining the offset value through the user plane, it can reduce the implementation complexity and directly identify the associated first PDU Set and second PDU Set according to the pre-configured offset value.

[0023] In combination with the first aspect or any implementation thereof, in some other implementations, the first association information is the first PDU Set SN, and the second association information is the second PDU Set SN; or, the first association information is the first timestamp, and the second association information is the second timestamp.

[0024] Combined with the first aspect or any implementation thereof, in some other implementations, the associated information is included in the general packet radio service tunneling protocol-user plane (GTP-U) header of the PDU Set.

[0025] Exemplarily, the associated information is included in the GTP-U layer of the data packet corresponding to the PDU Set.

[0026] Combined with the first aspect or any implementation thereof, in some other implementations, the first indication information includes the identifier of the first traffic flow and the identifier of the second traffic flow; or, the first indication information includes the identifier of the first traffic flow, the identifier of the first session to which the first traffic flow belongs, the identifier of the first terminal device to which the first session belongs, the identifier of the second traffic flow, the identifier of the second session to which the second traffic flow belongs, and / or the identifier of the second terminal device to which the second session belongs.

[0027] In a second aspect, a communication method is provided. The method may be executed by a user plane function network element. Without special instructions, the "user plane function network element" may refer to the user plane function network element itself or a device capable of supporting the user plane function network element to implement its functions. For the sake of convenient description, the user plane function network element is uniformly used hereinafter to describe.

[0028] The method includes: the user plane function network element obtains first indication information, which is used to indicate that a first traffic flow is associated with a second traffic flow; the user plane function network element receives a first PDU Set of the first traffic flow and a second PDU Set of the second traffic flow, the first PDU Set carries third associated information, and the second PDU Set carries fourth associated information, and the third associated information and the fourth associated information are used for the user function network element to determine that the first PDU Set is associated with the second PDU Set; the user plane function network element adds associated information to the first PDU Set and / or the second PDU Set according to the first indication information, the third associated information, and the fourth associated information, and the associated information is used for the access network device to determine that the first PDU Set is associated with the second PDU Set; the user plane function network element sends the first PDU Set and the second PDU Set to the access network device.

[0029] Based on the above method, the user plane function network element can determine that the first PDU Set of the first service flow is associated with the second PDU Set of the second service flow based on the first indication information, as well as the third association information carried in the first PDU Set and the fourth association information carried in the second PDU Set, and add association information that can be obtained by the access network device to the first PDU Set and / or the second PDU Set, so that the access network device can determine that the first PDU Set of the first service flow is associated with the second PDU Set of the second service flow based on the association information carried in the first PDU Set and / or the second PDU Set, and then synchronously transmit the associated PDU Sets, thereby realizing the synchronous transmission guarantee of multiple service flows.

[0030] Combined with the second aspect, in some implementation manners, the user plane function network element adding association information to the first PDU Set and / or the second PDU Set according to the first indication information, the third association information, and the fourth association information includes: the user plane function network element determining that the first service flow is associated with the second service flow according to the first indication information; the user plane function network element determining that the first PDU Set is associated with the second PDU Set according to the third association information carried in the first PDU Set and the fourth association information carried in the second PDU Set; and the user plane function network element adding the association information to the first PDU Set and / or the second PDU Set.

[0031] Combined with the second aspect or any of its implementation manners, in some other implementation manners, the user plane function network element determining that the first PDU Set is associated with the second PDU Set according to the third association information and the fourth association information includes: when the third association information is the same as the fourth association information, the difference between the third association information and the fourth association information is less than or equal to a threshold, the difference between the third association information and the fourth association information is within the threshold range, or the difference between the third association information and the fourth association information is equal to an offset value, the user plane function network element determines that the first PDU Set is associated with the second PDU Set, and the offset value is the offset value between the association information of the associated PDU Sets between the first service flow and the second service flow.

[0032] Based on the above implementation manners, the user plane function network element can determine the associated PDU Sets in multiple service flows, and then add association information that can be obtained by the access network device to the associated PDU Sets, which helps to realize the synchronous transmission guarantee of multiple service flows.

[0033] In combination with the second aspect or any implementation thereof, in some other implementations, the threshold value and / or the offset value are from a session management function network element, or a policy control function network element, or an application function network element.

[0034] In combination with the second aspect or any implementation thereof, in some other implementations, the user plane function network element adds association information to the first PDU Set and / or the second PDU Set according to the first indication information, the third association information, and the fourth association information, including: the user plane function network element adds first association information to the first PDU Set and second association information to the second PDU Set according to the first indication information, the third association information, and the fourth association information, and the first association information and the second association information are the same.

[0035] Based on the above implementation, the user plane function network element can add the same association information to the associated PDU Sets, so that the access network device can synchronously transmit the PDU Sets carrying the same association information in the associated traffic flows.

[0036] In combination with the second aspect or any implementation thereof, in some other implementations, the first association information is the first PDU Set synchronization sequence identifier, and the second association information is the second PDU Set synchronization sequence identifier. That is, the user plane function network element adds the same PDU Set sequence identifier to the associated PDU Sets.

[0037] In combination with the second aspect or any implementation thereof, in some other implementations, the first association information is the first PDU Set SN, and the second association information is the second PDU Set SN. That is, the user plane function network element adds the same PDU Set SN to the associated PDU Sets.

[0038] In combination with the second aspect or any implementation thereof, in some other implementations, the association information is used to indicate the offset value between the identification information of the associated PDU Sets between the first traffic flow and the second traffic flow; the method further includes: the user plane function network element adds first identification information to the first PDU Set and second identification information to the second PDU Set, the first identification information is the same as the third association information, and the second identification information is the same as the fourth association information.

[0039] Based on the above implementation manner, the user plane function network element can provide the offset value between the identification information of the associated PDU Set between the first service flow and the second service flow to the access network device facing the user. Compared with pre-configuring this offset value in advance through the control plane, the obtained offset value can better conform to the current service flow, which helps to ensure the synchronous transmission of multiple service flows.

[0040] Combined with the second aspect or any of its implementation manners, in some other implementation manners, adding association information to the first PDU Set and / or the second PDU Set includes: adding the association information to the first PDU Set and not adding the association information to the second PDU Set, where the association information includes the identifier of the second service flow and the offset value; or, not adding the association information to the first PDU Set and adding the association information to the second PDU Set, where the association information includes the identifier of the first service flow and the offset value; or, adding first association information to the first PDU Set and adding second association information to the second PDU Set, where the first association information includes the identifier of the reference service flow and the first offset value, and the first offset value is the offset value between the identification information of the associated PDU Set between the first service flow and the reference service flow, and the second association information includes the identifier of the reference service flow and the second offset value, and the second offset value is the offset value between the identification information of the associated PDU Set between the second service flow and the reference service flow; or, adding first association information to the first PDU Set and adding second association information to the second PDU Set, where the first association information includes the identifier of the second service flow and the offset value, and the second association information includes the identifier of the first service flow and the offset value; or, adding first association information to the first PDU Set and adding second association information to the second PDU Set, where the first association information includes the first identification information and the second association information includes the first identification information, so that the access network device determines that the first PDU Set is associated with the second PDU Set based on the same first identification information carried in the associated first service flow and second service flow, and performs synchronous transmission on the associated first PDU Set and second PDU Set.

[0041] In combination with the second aspect or any implementation thereof, in some other implementations, the third association information and the first identification information are the first PDU Set synchronization sequence identifiers, such as PDU SetSN, and the fourth association information and the second identification information are the second PDU Set synchronization sequence identifiers, such as PDU Set SN; or, the third association information and the first identification information are the first timestamp, and the fourth association information and the second identification information are the second timestamp.

[0042] In combination with the second aspect or any implementation thereof, in some other implementations, the method further includes: the user plane function network element determines the offset value according to the third association information and the fourth association information.

[0043] Based on the above implementation, the user plane function network element can determine the offset value between the identification information of the associated PDU Sets of the first service flow and the second service flow. Compared with pre-configuring this offset value in advance through the control plane, the offset value obtained in this way can be more real-time and accurate, more in line with the current service flow, and helps to ensure the synchronous transmission of multiple service flows.

[0044] In combination with the second aspect or any implementation thereof, in some other implementations, the method further includes: the user plane function network element obtains third indication information, and the third indication information is used to indicate the user plane function network element to identify the associated PDU Set.

[0045] In combination with the second aspect or any implementation thereof, in some other implementations, the third indication information is further used to indicate the manner in which the user plane function network element identifies the associated PDU Set, and the manner is any one of the following manners: identification based on timestamp, or identification based on PDU SetSN.

[0046] In combination with the second aspect or any implementation thereof, in some other implementations, the identification based on timestamp includes at least one of the following manners: PDU Sets with the same timestamp are associated, PDU Sets with the difference between timestamps less than or equal to a threshold are associated, PDU Sets with the difference between timestamps equal to the offset value are associated, PDU Sets with the difference between timestamps within the threshold range are associated; and / or, the identification based on PDU Set SN includes at least one of the following manners: PDU Sets with the same PDU Set SN are associated, PDU Sets with the difference between PDU Set SNs less than or equal to a threshold are associated, PDU Sets with the difference between PDU Set SNs equal to the offset value are associated, PDU Sets with the difference between PDU Set SNs within the threshold range are associated.

[0047] In combination with the second aspect or any implementation thereof, in some other implementations, the method further includes: the user plane function network element obtains fourth indication information, where the fourth indication information is used to instruct the user plane function network element to mark the associated PDU Set.

[0048] In combination with the second aspect or any implementation thereof, in some other implementations, the first indication information includes the identifier of the first traffic flow and the identifier of the second traffic flow; or, the first indication information includes the identifier of the first traffic flow, the identifier of the first session to which the first traffic flow belongs, the identifier of the first terminal device to which the first session belongs, the identifier of the second traffic flow, the identifier of the second session to which the second traffic flow belongs, and / or the identifier of the second terminal device to which the second session belongs.

[0049] In a third aspect, a communication method is provided. The method may be executed by a user plane function network element. Without special instructions, the "user plane function network element" may refer to the user plane function network element itself or a device capable of supporting the user plane function network element to implement its functions. For the sake of description convenience, the user plane function network element is uniformly used hereinafter to describe.

[0050] The method includes: the user plane function network element obtains fifth indication information, where the fifth indication information is used to instruct the user plane function network element to add associated information to a first traffic flow, and the associated information is used for an access network device to determine the associated PDU Set between the first traffic flow and the second traffic flow; the user plane function network element receives a first PDU Set of the first traffic flow; the user plane function network element adds the associated information to the first PDU Set according to the fifth indication information; the user plane function network element sends the first PDU Set to the access network device.

[0051] Based on the above method, the user plane function network element can obtain information used to instruct the associated information added to the first traffic flow, and then add specific associated information to the PDU Set in the first traffic flow according to the obtained information. Based on this, in a scenario where multiple traffic flows that need to be synchronously transmitted correspond to multiple user plane function network elements, the multiple user plane function network elements can add specific associated information to the traffic flows, so as to ensure that the associated PDU Sets between the multiple traffic flows carry the same associated information, enabling the access network device to synchronously transmit the PDU Sets carrying the same associated information, thereby realizing the synchronous transmission guarantee of multiple traffic flows.

[0052] In combination with the third aspect, in some implementation manners, the fifth indication information includes a third timestamp corresponding to the first service flow and a third PDU Set SN corresponding to the third timestamp, and the association information added by the user plane function network element for the first PDU Set is the first PDU Set SN; adding the association information for the first PDU Set according to the fifth indication information includes: adding the first PDU Set SN for the first PDU Set according to the third timestamp, the third PDU Set SN, and the first timestamp carried by the first PDU Set.

[0053] Based on the above implementation manner, the user plane function network element can add a PDU Set SN for the current PDU Set based on the timestamp obtained in advance, the PDU Set SN corresponding to the timestamp, and the timestamp carried by the current PUD set. In this way, in a scenario where multiple service flows that need to be synchronously transmitted correspond to multiple user plane function network elements, as long as the timestamp corresponding to each service flow and the PDU Set SN corresponding to the timestamp are designed well, it can be ensured that the associated PDU Sets among the multiple service flows carry the same PDU Set SN, so that the access network device can determine the associated PDU Sets among the multiple service flows, so that the access network device can synchronously transmit the PDU Sets carrying the same PDU Set SN, thereby realizing the synchronous transmission guarantee of multiple service flows.

[0054] In combination with the third aspect or any of its implementation manners, in some other implementation manners, the method further includes: obtaining period information, where the period information is used to indicate the time interval between two adjacent PDU Sets of the first service flow; adding a second PDU Set SN for the first PDU Set according to the third timestamp, the third PDU Set SN, and the first timestamp carried by the first PDU Set includes: adding the first PDU Set SN for the first PDU Set according to the third timestamp, the third PDU Set SN, the first timestamp, and the period information.

[0055] In combination with the third aspect or any implementation thereof, in some other implementations, the fifth indication information includes the offset value of the PDU Set SN corresponding to the first traffic flow, and the association information added by the user plane function network element for the first PDU Set is the first PDU Set SN; adding association information for the first PDU Set according to the fifth indication information includes: adding the first PDU Set SN to the PDU Set according to the offset value and the fourth PDU Set SN carried by the first PDU Set, and the first PDU Set SN is offset from the fourth PDU Set SN by the offset value.

[0056] Based on the above implementation, the user plane function network element can adjust the PDU Set SN carried by the current PUD set based on the pre-obtained PDU Set SN offset value, and add the adjusted PDU Set SN to the current PDU Set. In this way, in a scenario where multiple traffic flows that need to be synchronously transmitted correspond to multiple user plane function network elements, as long as the offset values to be adjusted for each traffic flow are designed well, it can be ensured that the associated PDU Sets among multiple traffic flows carry the same PDU Set SN, enabling the access network device to determine the associated PDU Sets among multiple traffic flows, so that the access network device can synchronously transmit the PDU Sets carrying the same PDU Set SN, thereby realizing the synchronous transmission guarantee of multiple traffic flows.

[0057] In a fourth aspect, a communication method is provided. The method can be executed by an application function network element. Without special instructions, the "user plane function network element" may refer to the application function network element itself or a device capable of supporting the application function network element to implement its functions. For the sake of convenience of description, the application function network element is uniformly used hereinafter to describe.

[0058] The method includes: the application function network element determines synchronization assistance information, and the synchronization assistance information includes first indication information, and the first indication information is used to indicate that the first traffic flow and the second traffic flow are associated; the application function network element sends the synchronization assistance information to the policy control function network element.

[0059] Based on the above method, the application function network element can provide synchronization assistance information for the synchronous transmission of the PDU Sets associated among multiple traffic flows, which helps to realize the synchronous transmission guarantee of multiple traffic flows.

[0060] In combination with the fourth aspect, in some implementations, the synchronization assistance information includes second indication information, and the second indication information is used to indicate the synchronization requirement between the first traffic flow and the second traffic flow.

[0061] Based on the above implementation method, the application function network element can provide the synchronization requirement for the transmission of the associated PDU Set between multiple service flows. This synchronization requirement better conforms to the actual requirements of multiple service flows and helps to achieve the synchronization transmission guarantee of multiple service flows.

[0062] Combined with the fourth aspect or any of its implementation methods, in some other implementation methods, the synchronization requirement includes the maximum value of the transmission delay difference between the associated PDU Sets between the first service flow and the second service flow.

[0063] Combined with the fourth aspect or any of its implementation methods, in some other implementation methods, the synchronization assistance information further includes at least one of the following information: offset value, third indication information, fourth indication information, fifth indication information, or sixth indication information. Among them, the offset value is the offset value between the associated information of the associated PDU Sets between the first service flow and the second service flow; the third indication information is used to indicate the user plane function network element to identify the associated PDU Set; the fourth indication information is used to indicate the user plane function network element to mark the associated PDU Set; the fifth indication information is used to indicate the associated information added by the user plane function network element to the first service flow and / or the associated information added to the second service flow, and the associated information is used to determine the associated PDU Set between the first service flow and the second service flow; the sixth indication information is used to indicate the user plane function network element to add the associated information carried by the PDU Set to the GTP-U header.

[0064] Based on the above implementation method, the application function network element can provide more information for the synchronous transmission of the associated PDU Sets between multiple service flows, which helps to achieve the synchronous transmission guarantee of multiple service flows.

[0065] Combined with the fourth aspect or any of its implementation methods, in some other implementation methods, the third indication information is further used to indicate the manner in which the user plane function network element identifies the associated PDU Set, and the manner is any one of the following manners: identification based on timestamp, or identification based on PDU Set SN.

[0066] Combined with the fourth aspect or any of its implementation manners, in some other implementation manners, the fifth indication information includes the offset value of the PDU Set SN corresponding to the first service flow and / or the offset value of the PDU Set SN corresponding to the second service flow. The offset value of the PDU Set SN corresponding to the first service flow is the offset value of the PDU Set SN added by the user plane function network element for the PDU Set of the first service flow relative to the PDU Set SN added by the application server for the PDU Set of the first service flow. The offset value of the PDU Set SN corresponding to the second service flow is the offset value of the PDU Set SN added by the user plane function network element for the PDU Set of the second service flow relative to the PDU Set SN added by the application server for the PDU Set of the second service flow.

[0067] Based on the above implementation manners, the application function network element can provide a timestamp and the PDU Set SN corresponding to the timestamp, so that the user plane function network element can add a PDU Set SN for the current PDU Set based on the timestamp obtained in advance, the PDU Set SN corresponding to the timestamp, and the timestamp carried by the current PUDset. In this way, in a scenario where multiple service flows that need to be synchronously transmitted correspond to multiple user plane function network elements, as long as the timestamp corresponding to each service flow and the PDU Set SN corresponding to the timestamp are designed well, it can be ensured that the associated PDU Sets among the multiple service flows carry the same PDU Set SN, so that the access network device can determine the associated PDU Sets among the multiple service flows, and thus the access network device can synchronously transmit the PDU Sets carrying the same PDU Set SN, thereby realizing the synchronous transmission guarantee of multiple service flows.

[0068] Combined with the fourth aspect or any of its implementation manners, in some other implementation manners, the fifth indication information includes: the third timestamp corresponding to the first service flow and the first PDU Set SN corresponding to the third timestamp, and / or, the fourth timestamp corresponding to the second service flow and the third PDU Set SN corresponding to the fourth timestamp.

[0069] Based on the above implementation manner, the application function network element can provide a PDU Set SN offset value, enabling the user plane function network element to adjust the PDU Set SN carried in the current PUD set based on the pre-obtained PDU Set SN offset value and add the adjusted PDU Set SN to the current PDU Set. In this way, in a scenario where multiple service flows that require synchronous transmission correspond to multiple user plane function network elements, as long as the offset values to be adjusted for each service flow are designed well, it can be ensured that the PDU Sets associated with multiple service flows carry the same PDU Set SN, enabling the access network device to determine the associated PDU Sets among multiple service flows, so that the access network device can perform synchronous transmission on the PDU Sets carrying the same PDU Set SN, thereby achieving the synchronous transmission guarantee for multiple service flows.

[0070] Combined with the fourth aspect or any of its implementation manners, in some other implementation manners, the synchronization assistance information includes the sixth indication information, and the method further includes: the application function network element receives first configuration information from the application service provider, where the first configuration information is used to indicate synchronous transmission for the first service flow and the second service flow of the service; the application function network element sends second configuration information to the application server according to the first configuration information, where the second configuration information is used to indicate adding the same association information to the PDU Sets associated between the first service flow and the second service flow.

[0071] Based on the above implementation manner, a solution for the application layer to guarantee the synchronous transmission of multiple service flows can be provided.

[0072] Combined with the fourth aspect or any of its implementation manners, in some other implementation manners, the second configuration information is further used to indicate a synchronization type, where the synchronization type is single-user synchronization or multi-user synchronization. Single-user synchronization means that the first service flow and the second service flow are service flows of the same user, and multi-user synchronization means that the first service flow and the second service flow are service flows of different users.

[0073] In a fifth aspect, a communication method is provided. The method can be executed by an application service provider. Without special instructions, the "application service provider" can refer to the application service provider itself or a device capable of supporting the application service provider to implement its functions. For the sake of convenient description, the application service provider is uniformly used hereinafter to describe.

[0074] The method includes: the application service provider determines first configuration information, where the first configuration information is used to indicate synchronous transmission for the first service flow and the second service flow of the service; the application service provider sends the first configuration information to the application function.

[0075] Based on the above implementation manner, a solution for ensuring synchronous transmission of multiple service flows at the application layer can be provided.

[0076] In a sixth aspect, a communication method is provided. The method can be executed by an application server. Without special instructions, the "application server" may refer to the application server itself or a device capable of supporting the application server to implement its functions. For the sake of convenient description, the application server is uniformly used hereinafter to describe.

[0077] The method includes: the application server receives second configuration information from an application function, where the second configuration information is used to indicate adding the same association information to a PDU Set associated between a first service flow and a second service flow of a service; the application server adds the same association information to a first PDU Set of the first service flow and a second PDU Set of the second service flow according to the second configuration information.

[0078] Based on the above implementation manner, a solution for ensuring synchronous transmission of multiple service flows at the application layer can be provided.

[0079] In combination with the sixth aspect, in some implementation manners, the association information is a PDU SetSN.

[0080] In combination with the sixth aspect or any of its implementation manners, in some other implementation manners, the second configuration information is further used to indicate a synchronization type, where the synchronization type is single-user synchronization or multi-user synchronization. The single-user synchronization indicates that the first service flow and the second service flow are service flows of the same user, and the multi-user synchronization indicates that the first service flow and the second service flow are service flows of different users.

[0081] In a seventh aspect, a communication method is provided. The method can be executed by a user plane function network element. Without special instructions, the "user plane function network element" may refer to the user plane function network element itself or a device capable of supporting the user plane function network element to implement its functions. For the sake of convenient description, the user plane function network element is uniformly used hereinafter to describe.

[0082] The method includes: a user plane function network element receiving a first PDU Set of a first traffic flow and a second PDU Set of a second traffic flow, where the first PDU Set carries first association information, the second PDU Set carries second association information, and the first association information and the second association information are used to determine that the first PDU Set is associated with the second PDU Set; the user plane function network element adding the first association information to the GTP-U header of the first PDU Set and adding the second association information to the GTP-U header of the second PDU Set; and the user plane function network element sending the first PDU Set and the second PDU Set to an access network device.

[0083] Based on the above method, the user plane function network element can add the association information carried in the PDU Set to the GTP-U layer, so that the access network device can obtain the association information, thereby identifying the PDU Sets associated between multiple traffic flows according to the association information, and then performing synchronous transmission on the associated PDU Sets, so as to achieve the synchronous transmission guarantee of multiple traffic flows.

[0084] Combined with the seventh aspect, in some implementation manners, the method further includes: the user plane function network element receiving sixth indication information, where the sixth indication information is used for the user plane function network element to add the association information carried in the PDU Set to the GTP-U header.

[0085] Combined with the seventh aspect or any of its implementation manners, in some other implementation manners, the first association information and the second association information are PDU Set SN or timestamp.

[0086] In an eighth aspect, a communication method is provided. The method includes the method steps performed by an access network device in the first aspect or its implementation, the method steps performed by a user plane function network element in the second aspect or its implementation, and the method steps performed by an application function network element in the fourth aspect or its implementation. Alternatively, the method includes the method steps performed by an access network device in the first aspect or its implementation, the method steps performed by a user plane function network element in the third aspect or its implementation, and the method steps performed by an application function network element in the fourth aspect or its implementation. Alternatively, the method includes the method steps performed by an access network device in the first aspect or its implementation, the method steps performed by a user plane function network element in the seventh aspect or its implementation, and the method steps performed by an application function network element in the fourth aspect or its implementation. Alternatively, the method includes the method steps performed by an access network device in the first aspect or its implementation, the method steps performed by a user plane function network element in the seventh aspect or its implementation, the method steps performed by an application function network element in the fourth aspect or its implementation, the method steps performed by an application service provider in the fifth aspect or its implementation, the method steps performed by an application server in the sixth aspect or its implementation, and the method steps performed by an application function network element in the fourth aspect or its implementation.

[0087] In a ninth aspect, a communication device is provided. The communication device may be an access network device, a user plane function network element, an application function network element, an application service provider, or an application server, or may be a device, module, circuit, or chip configured to be disposed in an access network device, a user plane function network element, an application function network element, an application service provider, or an application server, or may be a device capable of being used in matching with an access network device, a user plane function network element, an application function network element, an application service provider, or an application server. In one design, the communication device may include modules corresponding one by one to the methods / operations / steps / actions described in the above corresponding aspect or its implementation. The module may be a hardware circuit, software, or a combination of a hardware circuit and software. In one design, the communication device may include a processing module and a communication module.

[0088] Among them, the sending module is used to perform the sending action in the method described above, and the processing module is used to perform the actions related to processing in the method described above.

[0089] In a tenth aspect, a communication device is provided, including a processing circuit and a storage medium. The storage medium stores instructions, and when the instructions are run by the processing circuit, the method in any of the above aspects or any of its possible implementations is implemented.

[0090] Optionally, the communication device may be an access network device, a user plane function network element, an application function network element, an application service provider, or an application server.

[0091] Optionally, the communication device may be a chip applied to an access network device, a user plane function network element, an application function network element, an application service provider, or an application server.

[0092] In an eleventh aspect, a communication device is provided, including a processing circuit configured to process data and / or information so that the method in any of the above aspects or its implementation manners is implemented. Optionally, the device may further include a memory configured to store programs or instructions. Optionally, the communication device may further include a communication interface configured to receive data and / or information and transmit the received data and / or information to the processing circuit. Optionally, the communication interface is further configured to output the data and / or information processed by the processing circuit. The communication interface may also be referred to as an interface circuit or a transceiver circuit.

[0093] Optionally, the communication device may be an access network device, a user plane function network element, an application function network element, an application service provider, or an application server.

[0094] Optionally, the communication device may be a chip applied to an access network device, a user plane function network element, an application function network element, an application service provider, or an application server.

[0095] In a twelfth aspect, a chip system is provided, including a processing circuit configured to run programs or instructions so that the method in any of the above aspects or its implementation manners is implemented. Optionally, the chip system may further include an input / output interface. Optionally, the chip system may further include a memory configured to store programs or instructions. The processing circuit may also be referred to as a logic circuit.

[0096] In a thirteenth aspect, a computer-readable storage medium is provided, where the computer-readable storage medium includes instructions that, when run by a processing circuit, cause the method in any of the above aspects or its implementation manners to be implemented.

[0097] In a fourteenth aspect, a computer program product is provided, where the computer program product includes computer program code or instructions that, when run, cause the method in any of the above aspects or its implementation manners to be implemented.

[0098] In a fifteenth aspect, a communication system is provided, which includes a combination of one or more of the following devices: a communication device implementing the communication device in the first aspect or any possible implementation of the first aspect, or a communication device implementing the communication device in the second aspect or any possible implementation of the second aspect, a communication device implementing the communication device in the third aspect or any possible implementation of the third aspect, a communication device implementing the communication device in the fourth aspect or any possible implementation of the fourth aspect, a communication device implementing the communication device in the fifth aspect or any possible implementation of the fifth aspect, a communication device implementing the communication device in the sixth aspect or any possible implementation of the sixth aspect, or a communication device implementing the communication device in the seventh aspect or any possible implementation of the seventh aspect. Description of the Drawings

[0099] Figure 1 FIG. is a schematic diagram of a communication system applicable to an embodiment of the present application.

[0100] Figure 2 FIG. is a schematic flowchart of a communication method 200 provided by an embodiment of the present application.

[0101] Figure 3 FIG. is a schematic flowchart of a communication method 300 provided by an embodiment of the present application.

[0102] Figure 4 FIG. is a schematic flowchart of a communication method 400 provided by an embodiment of the present application.

[0103] Figure 5 FIG. is a schematic flowchart of a communication method 500 provided by an embodiment of the present application.

[0104] Figure 6 FIG. is a schematic flowchart of a communication method 600 provided by an embodiment of the present application.

[0105] Figure 7 FIG. is a schematic flowchart of a communication method 700 provided by an embodiment of the present application.

[0106] Figure 8 FIG. is a schematic flowchart of a communication method 800 provided by an embodiment of the present application.

[0107] Figure 9 FIG. is a schematic flowchart of a communication method 900 provided by an embodiment of the present application.

[0108] Figure 10 FIG. is a schematic flowchart of a communication method 1000 provided by an embodiment of the present application.

[0109] Figure 11 FIG. is a schematic structural diagram of a device provided by an embodiment of the present application.

[0110] Figure 12It is another structural schematic diagram of the device provided by the embodiment of the present application.

[0111] Figure 13 It is a schematic diagram of a chip system provided by the embodiment of the present application. Detailed implementation manners

[0112] To facilitate the understanding of the embodiments of the present application, before introducing the embodiments of the present application, the following points are first explained.

[0113] "Indication" includes direct indication (also known as explicit indication) and implicit indication. Among them, directly indicating information A means including this information A; implicitly indicating information A means indicating information A through the correspondence between information A and information B and directly indicating information B. Among them, the correspondence between information A and information B can be predefined, prestored, pre-burned, or pre-configured. Information C is used for the determination of information D, which includes both the case where information D is determined only based on information C and the case where it is determined based on information C and other information. In addition, when information C is used for the determination of information D, there can also be an indirect determination case. For example, information D is determined based on information E, and information E is determined based on information C. "Network element A sends information A to network element B" can be understood as the destination end of this information A or an intermediate network element in the transmission path between the destination ends being network element B, which can include sending information to network element B directly or indirectly. "Network element B receives information A from network element A" can be understood as the source end of this information A or an intermediate network element in the transmission path between the source ends being network element A, which can include receiving information from network element A directly or indirectly. Necessary processing may be performed on the information between the source end and the destination end where the information is sent, such as format change, etc., but the destination end can understand the valid information from the source end. The various digital numbers such as first, second, etc. are only for the convenience of description and are not used to limit the scope of the embodiments of this application. For example, they are used to distinguish different messages, different information, etc. "Predefined" can be implemented by pre-saving the corresponding codes, tables, or other ways that can be used to indicate relevant information in the device. This application does not limit its specific implementation method. The "protocol" involved can refer to the standard protocols in the communication field. For example, it can include the long term evolution (LTE) protocol, the new radio (NR) protocol, and the relevant protocols applied to future communication systems. This application does not limit this. Words such as "exemplary", "for example", "exemplarily", "as (another) example", etc. are used to represent examples, illustrations, or explanations. Any embodiment or design solution described as "exemplary" in this application should not be interpreted as being more preferred or having more advantages than other embodiments or design solutions. The terms "include", "comprise", "have" and their variants all mean "including but not limited to", unless otherwise specifically emphasized in other ways. "Multiple" means two or more. "And / or" describes the association relationship of associated objects and indicates that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one (item)" or its similar expression refers to any combination of these items, including any combination of single item (item) or plural items (items).For example, at least one of a, b, and c may represent: a, or b, or c, or a and b, or a and c, or b and c, or a, b, and c. Wherein a, b, and c may each be single or multiple. Descriptions such as "when...", "in the case of...", "if", and "if" all refer to the device making corresponding processing under a certain objective situation, not limited to time, and do not require the device to have a judgment action when implemented, nor does it mean there are other limitations.

[0114] In addition, the network architecture and service scenarios described in the embodiments of the present application are for more clearly illustrating the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those of ordinary skill in the art know that with the evolution of the network architecture and the emergence of new service scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0115] Next, a communication system to which the embodiments of the present application can be applied will be described.

[0116] The embodiments of the present application can be applied to various communication systems, such as: LTE system, frequency division duplex (FDD) system, time division duplex (TDD) system, universal mobile telecommunication system (UMTS), worldwide interoperability for microwave access (WiMAX) communication system, fifth generation (5G) system or NR system, sixth generation (6G) system or future communication systems, etc. The 5G mobile communication system described in the present application includes a non-standalone (NSA) 5G mobile communication system or a standalone (SA) 5G mobile communication system. The communication system may also be a public land mobile network (PLMN) network, device-to-device (D2D) communication system, machine-to-machine (M2M) communication system, Internet of Things (IoT) communication system, vehicle-to-everything (V2X) communication system, uncrewed aerial vehicle (UAV) communication system or other communication systems.

[0117] Exemplarily, Figure 1 A network architecture diagram of an embodiment to which the present application is applicable is shown. As Figure 1 shown, the network architecture may specifically include three parts, namely, a terminal device part, a data network (DN), and a carrier network part. The functions of the network elements of each part will be briefly described below.

[0118] The terminal device part may include a terminal device, which may also be referred to as a user equipment (UE). The terminal device in this application is a device with wireless transceiver functions and can communicate with one or more core network (CN) devices via an access network device (or also referred to as an access device) in a radio access network (RAN). The terminal device may also be referred to as an access terminal, terminal, user unit, user station, mobile station, mobile device, remote station, remote terminal, mobile device, user terminal, user agent, or user device, etc. The terminal device can be deployed on land, including indoor or outdoor, handheld or vehicle-mounted; it can also be deployed on water (such as a ship, etc.); it can also be deployed in the air (such as an airplane, balloon, satellite, etc.). The terminal device can be a cellular phone, cordless phone, session initiation protocol (SIP) phone, smart phone, mobile phone, wireless local loop (WLL) station, personal digital assistant (PDA), etc. Alternatively, the terminal device can also be a handheld device with wireless communication functions, a computing device, or other devices connected to a wireless modem, a vehicle-mounted device, a wearable device, a drone device, or a terminal in the Internet of Things, vehicle-to-everything network, any form of terminal in a 5G network and future networks, a relay user equipment, or a terminal in a future evolved 6G network, etc. Among them, the relay user equipment can be, for example, a 5G residential gateway (RG). For example, the terminal device can be a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc. The terminal device here refers to a 3GPP terminal. The embodiments of this application do not limit the specific technologies and specific device forms adopted by the terminal device.

[0119] A data network, which can also be referred to as a packet data network (PDN), is usually a network located outside the operator's network, such as a third-party network. Of course, in some implementation manners, the DN can also be deployed by the operator, that is, the DN belongs to a part of the PLMN. The operator's network can access multiple data networks DN, and various services can be deployed on the data network DN to provide services such as data and / or voice for terminal devices. The terminal device can also access the data network DN through the operator's network, use the operator services deployed on the data network DN, and / or the services provided by a third party.

[0120] The operator network part includes but is not limited to the (radio) access network ((R)AN) part and the core network (CN) part.

[0121] (R)AN can be regarded as a sub-network of the operator network and is an implementation system between the service nodes and the terminal devices in the operator network. For a terminal device to access the operator network, it first passes through the (R)AN and then can be connected to the service nodes of the operator network through the (R)AN. The access network device (RAN device) in the embodiments of the present application is a device that provides wireless communication functions for terminal devices and can also be referred to as a network device. The RAN device includes but is not limited to: the next generation node base station (gNB) in the 5G system, the evolved node B (eNB) in the long term evolution (LTE), the radio network controller (RNC), the node B (NB), the base station controller (BSC), the base transceiver station (BTS), the home base station (for example, home evolved node B, or home node B, HNB), the base band unit (BBU), the transmitting and receiving point (TRP), the transmitting point (TP), the pico base station device, the mobile switching center, or the network device in the future network, etc. In systems using different radio access technologies, the names of the devices with the functions of access network devices may be different. The embodiments of the present application do not limit the specific technologies and specific device forms adopted by the access network devices.

[0122] The CN part includes but is not limited to the following network functions (NFs): User Plane Function (UPF), Network Exposure Function (NEF), Network Function Repository Function (NRF), Policy Control Function (PCF), UDM, UDR, Network Data Analytics Function (NWDAF), Authentication Server Function (AUSF), Access and Mobility Management Function (AMF), Session Management Function (SMF), and Application Function (AF).

[0123] The following provides a further brief description of the NF functions included in the CN.

[0124] 1. The UPF is the gateway for the operator network to communicate with the data network DN, mainly providing user plane functions such as forwarding and processing of user messages, connection to the DN, session anchor point, and execution of quality of service (QoS) policies.

[0125] 2. The NEF is a control plane function, mainly used to securely expose the services and capabilities provided by 3GPP network functions to the outside (such as AF). The NEF also allows authenticated and authorized application functions to securely provide information in the 3GPP network.

[0126] 3. The NRF is a control plane function that can be used to maintain real-time information about network functions and services in the network.

[0127] 4. The PCF is a control plane function that supports a unified policy framework to govern network behavior, provides policy rules and subscription information related to policy decisions to other control functions, etc.

[0128] 5. The UDM is a control plane function, mainly responsible for storing the subscription data of subscribed users in the operator network.

[0129] 6. UDR is a control plane function mainly responsible for data storage and retrieval. For example, it provides the functions of storing and retrieving subscription data for UDM, storing and retrieving policy data for PCF, storing and retrieving the NF group ID (group ID) information of users, etc.

[0130] 7. AUSF is a control plane function, usually used for primary authentication, that is, the authentication between the terminal device (subscribed user) and the operator network.

[0131] 8. AMF is a control plane function mainly responsible for access control and mobility management of the terminal device accessing the operator network. For example, it includes functions such as mobile status management, allocating user temporary identity identifiers, authenticating and authorizing users, etc.

[0132] 9. SMF is a control plane function mainly responsible for session management (such as session establishment, modification, and release), selection and control of the UPF network function, selection of the service and session continuity (SSC) mode, roaming, and other session-related functions.

[0133] 10. AF is a control plane function used to provide application layer information. AF is mainly divided into two categories: The first category is the AF that is considered trusted by the operator according to the operator's deployment. This type of AF can directly interact with other network functions in the network; the second category is the AF that the operator does not allow to directly access network functions, such as third-party AF. This type of AF can interact through other network functions in the NEF network.

[0134] Figure 1 Among them, Nnef, Nnrf, Npcf, Nudm, Nudr, Nausf, Namf, Nsmf, N1, N2, N3, N4, N6, and N9 are interface sequence numbers. Exemplarily, the meanings of the above interface sequence numbers can be referred to the meanings defined in the 3GPP standard protocol. This application does not limit the meanings of the above interface sequence numbers. It should be noted that Figure 1 The interface names between the various network functions in are only examples. In specific implementations, the interface names of this system architecture may also be other names, and this application does not limit this. In addition, the names of the messages (or signaling) transmitted between the above-mentioned network elements are also only examples and do not constitute any limitation to the functions of the messages themselves. In Figure 1 In the network architecture shown, the network elements can communicate through interfaces. The interfaces between the network elements can be point-to-point interfaces or service-based interfaces, and this application does not limit this.

[0135] It should be understood that the network architecture shown above is only an exemplary illustration, and the network architecture applicable to the embodiments of the present application is not limited thereto. Any network architecture that can implement the functions of the above-mentioned network elements is applicable to the embodiments of the present application.

[0136] It should also be understood that Figure 1 the functions or network elements such as AMF, SMF, UPF, PCF, UDM, AUSF, UDR, NEF, NRF, AF shown in can be understood as network elements for implementing different functions. For example, they can be combined into network slices as needed. These network elements can be individual devices, or can be integrated into the same device to implement different functions, or can be network elements in hardware devices, or can be software functions running on dedicated hardware, or can be virtualized functions instantiated on a platform (such as a cloud platform). The present application does not limit the specific form of the above-mentioned network elements.

[0137] It should also be understood that the above names are only defined for the convenience of distinguishing different functions and should not constitute any limitation to the present application. The present application does not exclude the possibility of using other names in 6G networks and future other networks. For example, in 6G networks, some or all of the above-mentioned network elements may continue to use the terms in 5G, or may use other names, etc.

[0138] To facilitate the understanding of the embodiments of the present application, several concepts or terms related to the embodiments of the present application are briefly described below.

[0139] The concepts or terms introduced below are described based on the concepts or terms defined in the reference protocol, but it does not mean that the embodiments of the present application can only be applied to existing systems. The concepts or terms related to the embodiments of the present application can be applied to future systems. And the specific names of the concepts or terms therein (such as the concepts or terms involving functional descriptions) can be adjusted with the development of future systems.

[0140] 1. QoS flow

[0141] When there is a service communication requirement, the terminal device will establish a data connection session (such as a protocol data unit (PDU) session, and the PDU session will be used as an example for subsequent description). A PDU session can have one or more QoS flows, and the service data stream or service flow is carried on the QoS flow. Specifically, the terminal device obtains an Internet Protocol (IP) address through the PDU session establishment process to interact with the service server and realize service communication. And 5GS maps the service to different QoS flows based on the service flow description information and performs corresponding QoS processing on the service flow.

[0142] 2. QoS Flow Identifier (QFI)

[0143] The QFI is the unique identifier for different QoS flows within a PDU session.

[0144] 3. QoS Rule

[0145] The QoS rule is the QoS configuration sent to the terminal device side. The QoS rule can contain at least one of the following information: QFI, packet filter (such as IP quintuple), or QoS rule identifier, etc.

[0146] 4. QoS Profile

[0147] The QoS profile is the QoS configuration sent to the RAN side. Specifically, it can contain at least one of the following information: 5G QoS Identifier (5QI), allocation and retention priority (ARP), guaranteed flow bit rate (GFBR) / maximum flow bit rate (MFBR), or QFI, etc.

[0148] 5. N4 Rule

[0149] The N4 rule is the service flow identification and processing rule sent to the UPF side, which can contain at least one of the following information: packet detection rule, usage reporting rule, or QoS enforcement rule, etc. Among them, the QoS enforcement rule can contain at least one of the following information: maximum bit rate, guaranteed bit rate, or average window, etc.

[0150] 6. Protocol Data Unit Set

[0151] The QoS mechanism guarantees services at the granularity of packets. For example, service guarantee is performed through the packet error rate (PER) or packet delay budget (PDB) in the QoS parameters. The packets of a certain service will be mapped to the same QoS flow and processed and transmitted one by one using the same QoS parameters. In other words, all packets within a QoS flow will be processed equally and without discrimination during the transmission process.

[0152] In the research of extended reality and media service (XRM), real-time media services, such as currently emerging virtual reality (VR), augmented reality (AR), mixed reality (MR), or cloud gaming services, have extremely stringent requirements for end-to-end latency. Moreover, the granularity of data processing during the encoding, rendering, and decoding processes of these services is no longer the data packet. For example, when encoding service data at the upper service layer (such as the media layer) at the sending end, encoding is often performed at the granularity of media frames or slices, that is, media frames or slices can be independently encoded; at the same time, the receiving end of the service will also decode and display the received service data at the same granularity of media frames or slices. Data units such as media frames or slices often contain multiple data packets. If a data packet in a data unit such as a media frame or slice is lost or damaged, the entire data unit may be difficult to correctly decode and display.

[0153] Therefore, the standard introduces a QoS mechanism at the PDU Set granularity, that is, it will give the loss rate or latency requirements at the PDU Set granularity, etc. The communication system identifies the relationship between different data packets and PDU Sets, clarifies which data packets are included in a PDU Set, and schedules, processes, and transmits all the data packets within the PDU Set as a whole based on the QoS parameters at the PDU Set granularity, thereby ensuring the user's service experience.

[0154] 7. Multimodal Services

[0155] Multimodal services generally refer to services that contain multiple modal service flows. Exemplarily, multimodal service flows can be service flows of different modalities such as audio streams, video streams, tactile streams, temperature streams, and / or brightness streams. For example, common multimedia services can include audio streams, video streams, and / or control data, etc.

[0156] To provide a good and consistent service experience, synchronous transmission guarantee is required between multiple service flows of multimodal services.

[0157] Table 1 shows an example of the synchronization requirements between multiple service flows of multimodal services.

[0158] Table 1

[0159]

[0160] As shown in Table 1, there are certain synchronous delay requirements between the audio-haptic or visual-haptic of the multimodal service. It should be noted that for each media component, "delay" refers to the delay situation of this media component compared with other media components. For example, for audio-haptic, an audio delay of 50 milliseconds (ms) is relative to haptic.

[0161] Currently, in the discussion of the 3rd generation partnership project (3GPP) standard, the support for multimodal services has been preliminarily determined, but how to ensure the synchronous transmission between multiple service flows of multimodal services has not been clearly discussed and defined.

[0162] In view of the above problems, embodiments of the present application provide a communication method and a communication device, aiming to provide a solution for ensuring the synchronous transmission between multiple service flows of multimodal services.

[0163] The method embodiments of the present application will be described below.

[0164] Embodiments of the present application can be applied to scenarios where multiple service flows that require synchronous transmission guarantee are transmitted through the same UPF, or can also be applied to scenarios where multiple service flows that require synchronous transmission guarantee are transmitted through multiple UPFs. The solutions in the two scenarios will be described separately below.

[0165] Scenario 1: Multiple service flows that require synchronous transmission guarantee are transmitted through the same UPF

[0166] Figure 2 It is a schematic flowchart of communication method 200 provided by an embodiment of the present application.

[0167] Method 200 can be executed by an access network device, a UPF, an SMF, a PCF, and / or an AF. Without special instructions, "access network device", "UPF", "SMF", "PCF", or "AF" can refer to the access network device, UPF, SMF, PCF, or AF itself, or can also refer to a device capable of supporting the access network device, UPF, SMF, PCF, or AF to implement its functions. For the convenience of description, the access network device, UPF, SMF, PCF, or AF will be uniformly used to describe below.

[0168] Method 200 includes at least some of the following content.

[0169] Optionally, in step 201, the AF determines synchronous assistance information.

[0170] Among them, the synchronization assistance information is used for the synchronous transmission of the first service flow and the second service flow. It should be noted that there may be two or more service flows that require synchronous transmission guarantee. The implementation of this application only takes the first service flow and the second service flow among them as examples to describe the solutions of the embodiments of this application. The embodiments of this application can be applied to the synchronous transmission guarantee of more service flows. It should also be noted that the multiple service flows that require synchronous transmission guarantee in the embodiments of this application can be multiple service flows of the same service, or multiple service flows of the same application. These multiple service flows can be multiple service flows for the same terminal device, or multiple service flows for multiple terminal devices, without limitation. It should also be noted that the various embodiments of this application can be applied to the synchronous transmission guarantee of multiple service flows of multi-modal services, or can be applied to other scenarios of multiple service flows that require synchronous transmission guarantee, without limitation.

[0171] The synchronization assistance information may include first indication information. The first indication information is used to indicate that the first service flow and the second service flow are associated. The first service flow and the second service flow being associated means that the first service flow and the second service flow need to be guaranteed for synchronous transmission.

[0172] Exemplarily, the first indication information may be flow description information, which is used to determine the first service flow and the second service flow that need to be synchronously processed. For example, the first indication information may include description information such as the IP five-tuple, IP three-tuple, etc. of the first service flow, and the IP five-tuple, IP three-tuple, etc. of the second service flow. For another example, the first indication information may include the identifier of the first service flow and the identifier of the second service flow, such as the application identifier of the first service flow and the application identifier of the second service flow. For another example, when the first service flow is the service flow of the first terminal device and the second service flow is the service flow of the second terminal device, the first indication information may include the identifier of the first service flow, the identifier of the first session to which the first service flow belongs, the identifier of the first terminal device to which the first session belongs, the identifier of the second service flow, the identifier of the second session to which the second service flow belongs, and / or the identifier of the second terminal device to which the second session belongs. For another example, the AF can indicate the association between the first service flow and the second service flow by carrying the same synchronization identifier in the flow description information of the first service flow and the flow description information of the second service flow, that is, the first service flow and the second service flow carrying the same synchronization identifier are associated.

[0173] Optionally, the synchronization assistance information may further include second indication information. The second indication information is used to indicate the synchronization requirement between the first service flow and the second service flow. Exemplarily, the synchronization requirement may indicate the maximum value of the transmission delay difference between the PDU Sets associated between the first service flow and the second service flow; it may also be an indication of the common transmission delay requirement of the PDU Sets associated between the first service flow and the second service flow, that is, the upper limit of the delay for all the associated PDU Sets to complete transmission. For example, the PDU Set #A of the first service flow and the PDU Set #B of the second service flow need to be completely transmitted under the delay requirement corresponding to this synchronization requirement, that is, the delay requirement from the reception of the first data packet of the PDU Set #A and the PDU Set #B to the completion of the transmission of the last data packet. When the synchronization assistance information does not include the second indication information, the PCF may determine the synchronization requirement between the first service flow and the second service flow by itself, or the access network device may independently determine the synchronization requirement between the first service flow and the second service flow. For example, the access network device may transmit the associated PDU Sets strictly according to the same transmission delay.

[0174] In addition, it should be noted that there may be two or more PDU Sets that need to be synchronously transmitted and guaranteed between the first service flow and the second service flow. The embodiments of the present application only describe the solutions of the embodiments of the present application by taking the first PDU Set and the second PDU Set as examples. The embodiments of the present application can be applied to the synchronous transmission guarantee of more associated PDU Sets.

[0175] Optionally, the synchronization assistance information further includes at least one of the following information: offset value, third indication information, or fourth indication information.

[0176] The offset value is the offset value between the associated information of the PDU Sets associated between the first service flow and the second service flow. For example, the PDU Set A of the first service flow is associated with the PDU Set B of the second service flow. The PDU Set A carries the associated information A, and the PDU Set B carries the associated information B. This offset value is the offset value between the associated information A and the associated information B. Exemplarily, the associated information here may be the real-time transport protocol (RTP) timestamp of the PDU Set, PDU Set SN, or other synchronization identifiers. Among them, the RTP timestamp is used to represent the generation or transmission time of the PDU Set carrying this timestamp information. The PDU Set SN is used to represent the order of the PDU Set. The synchronization identifier is used to identify the identification information for synchronizing the PDU Set.

[0177] It should be noted that when carrying the offset value, the offset value also carries identification information for indicating the reference service flow, that is, the offset value is the offset value between the current service flow and the reference service flow.

[0178] The third indication information is used to indicate the UPF to identify the associated PDU Set, that is, to identify the associated PDU Set in the associated service flow. For example, when the UPF is default to identify the associated PDU Set, the synchronization assistance information may not include the third indication information, or the UPF identifies the associated PDU Set in the associated service flow based on the fourth indication information mentioned later. Optionally, the third indication information is further used to indicate the manner in which the UPF identifies the associated PDU Set. When there is only one default identification method, the third indication information may not indicate the manner in which the UPF identifies the associated PDU Set. Exemplarily, the manner in which the UPF identifies the associated PDU Set is any one of the following: identification based on the RTP timestamp, or identification based on the PDU Set SN, where the identification method based on the PDU Set SN is applicable to the scenario where the application server (AS) uses an RTP extension header carrying the PDU Set SN or the scenario where the application server uses other protocol headers carrying the PDU Set SN or the synchronization identifier.

[0179] The identification based on the RTP timestamp includes at least one of the following methods: associating PDU Sets with the same RTP timestamp, associating PDU Sets with the difference between RTP timestamps less than or equal to a threshold, associating PDU Sets with the difference between RTP timestamps within a threshold range, and associating PDU Sets with the difference between RTP timestamps equal to an offset value. For the method of associating PDU Sets with the same RTP timestamp, the UPF can perform association identification based on the timestamps in the RTP headers of the downlink data packets in the first service flow and the second service flow, and determine the association of PDU Sets with the same RTP timestamp. For the method of associating PDU Sets with the difference between RTP timestamps less than or equal to the threshold K1, the UPF can perform association identification based on the timestamps in the RTP headers of the downlink data packets in the first service flow and the second service flow, and determine the association of PDU Sets with the difference between RTP timestamps within the threshold range (0, K1). In this method, the synchronization assistance information can also include the RTP timestamp threshold for identifying the PDU Set association relationship. For the method of associating PDU Sets with the difference between RTP timestamps within the threshold range (M1, N1), the UPF can perform association identification based on the timestamps in the RTP headers of the downlink data packets in the first service flow and the second service flow, and determine the association of PDU Sets with the difference between RTP timestamps within the threshold range (M1, N1), where 0 < M1 < N1. For the method of associating PDU Sets with the difference between RTP timestamps equal to the offset value, the UPF can perform association identification based on the timestamps in the RTP headers of the downlink data packets in the first service flow and the second service flow, and determine the association of PDU Sets with the difference between RTP timestamps equal to the offset value. In this method, the synchronization assistance information can also include the offset value.

[0180] Identifying based on the PDU Set SN includes at least one of the following methods: associating PDU Sets with the same PDU Set SN, associating PDU Sets with the difference between PDU Set SNs less than or equal to a threshold, associating PDU Sets with the difference between PDU Set SNs within a threshold range, and associating PDU Sets with the difference between PDU Set SNs equal to an offset value. For the method of associating PDU Sets with the same PDU Set SN, the UPF can perform association identification based on the PDU Set SN in the RTP header of the downlink data packets in the first service flow and the second service flow, and determine that the PDU Sets with the same PDU Set SN are associated. For the method of associating PDU Sets with the difference between PDU Set SNs less than or equal to the threshold K2, the UPF can perform association identification based on the PDU Set SN in the RTP header of the downlink data packets in the first service flow and the second service flow, and determine that the PDU Sets with the PDU Set SN difference within the threshold range (0, K2) are associated. In this method, the synchronization assistance information can also include the PDU Set SN threshold for identifying the PDU Set association relationship. For the method of associating PDU Sets with the difference between PDU Set SNs within the threshold range (M2, N2), the UPF can perform association identification based on the PDU Set SN in the RTP header of the downlink data packets in the first service flow and the second service flow, and determine that the PDU Sets with the PDU Set SN difference within the threshold range are associated. In this method, the synchronization assistance information can also include the PDU Set SN threshold range (M2, N2) for identifying the PDU Set association relationship, where 0 < M2 < N2. For the method of associating PDU Sets with the difference between PDU Set SNs equal to the offset value, the UPF can perform association identification based on the PDU Set SN in the RTP header of the downlink data packets in the first service flow and the second service flow, and determine that the PDU Sets with the difference between PDU Set SNs equal to the offset value are associated. In this method, the synchronization assistance information can also include this offset value.

[0181] In the embodiments of the present application, the threshold and the offset value can be interchanged.

[0182] The fourth indication information is used to indicate the PDU Set associated with the UPF marking. For example, when the PDU Set associated with the UPF is marked by default, the synchronization assistance information may not include the fourth indication information. Optionally, the fourth indication information is further used to indicate the manner in which the UPF marks the associated PDU Set. Optionally, the fourth indication information is also used to indicate the UPF to identify the associated PDU Set. When there is only one default marking method, the fourth indication information may not indicate the manner in which the UPF marks the associated PDU Set. Exemplarily, the manner in which the UPF marks the associated PDU Set is any one of the following: adding the same association information to the associated PDU Set, where the association information may be the RTP timestamp of the PDU Set, the PDU Set SN, or other synchronization identifiers.

[0183] Optionally, in step 202, the AF sends synchronization assistance information to the PCF. Correspondingly, the PCF receives the synchronization assistance information from the AF.

[0184] In step 203, the PCF sends the first indication information to the SMF according to the received synchronization assistance information. Correspondingly, the SMF receives the first indication information from the PCF.

[0185] Optionally, when the synchronization assistance information further includes the second indication information, the offset value, the third indication information, or the fourth indication information, the PCF also sends the second indication information, the offset value, the third indication information, or the fourth indication information to the SMF. Correspondingly, the SMF also receives the second indication information, the offset value, the third indication information, or the fourth indication information from the PCF.

[0186] Optionally, if the PCF does not receive the synchronization assistance information from the AF side, the synchronization assistance information may be from the local configuration on the PCF side. That is, the PCF generates the above first indication information, second indication information, offset value, third indication information, or fourth indication information by itself. Exemplarily, the operator configures the above information for the multi-modal service by itself, and the information may be from the agreement between the operator and the third-party application manufacturer.

[0187] In step 204, the SMF sends the first indication information to the UPF according to the information received from the PCF. Correspondingly, the UPF receives the first indication information from the SMF.

[0188] Optionally, when the SMF also receives the offset value, the third indication information, or the fourth indication information, the SMF also sends the offset value, the third indication information, or the fourth indication information to the UPF. Correspondingly, the UPF also receives the offset value, the third indication information, or the fourth indication information from the SMF.

[0189] It should be noted that the form of the first indication information, offset value, third indication information, or fourth indication information sent by the SMF to the UPF may be the same as or different from the first indication information, offset value, third indication information, or fourth indication information received by the SMF from the PCF, without limitation.

[0190] Step 205, the SMF sends the first indication information to the access network device. Correspondingly, the access network device receives the first indication information from the SMF.

[0191] Optionally, when the SMF also receives the second indication information, the SMF also sends the second indication information to the access network device. Correspondingly, the access network device also receives the second indication information from the SMF.

[0192] It should be noted that the form of the first indication information or second indication information sent by the SMF to the access network device may be the same as or different from the first indication information or second indication information received by the SMF from the PCF, without limitation.

[0193] Step 206, the UPF receives the first PDU Set of the first traffic flow and the second PDU Set of the second traffic flow.

[0194] Among them, the first PDU Set carries the third association information, the second PDU Set carries the fourth association information, and the third association information and the fourth association information are used by the UPF to determine that the first PDU Set is associated with the second PDU Set.

[0195] As an example, the third association information is the first PDU Set SN carried by the first PDU Set, and the fourth association information is the second PDU Set SN carried by the second PDU Set.

[0196] As another example, the third association information is the first RTP timestamp carried by the first PDU Set, and the fourth association information is the second RTP timestamp carried by the second PDU Set. Among them, the first RTP timestamp may represent the generation or transmission time of the first PDU Set, that is, the time when the first PDU Set is generated on the application server side or the time when it is sent from the application server side. The second RTP timestamp may represent the generation or transmission time of the second PDU Set, that is, the time when the second PDU Set is generated on the application server side or the time when it is sent from the application server side.

[0197] Prior to this, the UPF determines that the first traffic flow and the second traffic flow are associated with each other according to the received first indication information.

[0198] Step 207: The UPF adds association information to the first PDU Set and / or the second PDU Set according to the first indication information, the third association information, and the fourth association information.

[0199] Among them, the UPF adding association information to the first PDU Set and / or the second PDU Set is used for the access network device to determine that the first PDU Set is associated with the second PDU Set.

[0200] Among them, the first indication information is used to indicate that the first service flow is associated with the second service flow. The first service flow being associated with the second service flow means that the first service flow and the second service flow need to be synchronously transmitted and guaranteed. The first indication information may specifically be the identifier of the first service flow and the identifier information of the second service flow. Exemplarily, it may be the flow description information of the first service flow and the flow description information of the second service flow, such as the service data flow template (SDF) template, so as to ensure that the UPF determines the two associated service flows based on the SDF templates of the first service flow and the second service flow.

[0201] In a possible implementation, the UPF adds the above-mentioned association information to the GTP-U layer of the data packets included in the first PDU Set and / or the second PDU Set, such as in the GTP-U header. The information in the GTP-U layer is information that can be obtained by the access network device. Therefore, the access network device can determine that the first PDU Set is associated with the second PDU Set based on the association information added by the UPF to the first PDU Set and / or the second PDU Set. Exemplarily, the UPF adding the association information to the GTP-U header of the first PDU Set and / or the second PDU Set may refer to the UPF adding the association information to the GTP-U header of the data packets corresponding to the first PDU Set and / or the second PDU Set.

[0202] The embodiments of the present application do not limit the specific implementation manner of the UPF adding association information to the first PDU Set and / or the second PDU Set according to the first indication information, the third association information, and the fourth association information. In a possible implementation, the UPF determines that the first service flow is associated with the second service flow according to the first indication information; the UPF determines that the first PDU Set is associated with the second PDU Set according to the third association information and the fourth association information; the UPF adds association information to the associated first PDU Set and / or the second PDU Set.

[0203] The embodiments of the present application do not limit the specific implementation manner of the UPF determining that the first PDU Set is associated with the second PDU Set according to the third association information and the fourth association information.

[0204] In a possible implementation, when the third association information is the same as the fourth association information, the difference between the third association information and the fourth association information is less than or equal to a threshold, the difference between the third association information and the fourth association information is within the threshold range, or the difference between the third association information and the fourth association information is equal to an offset value, the UPF determines that the first PDU Set of the first traffic flow is associated with the second PDU Set of the second traffic flow.

[0205] When the UPF receives the third indication information from the SMF, the UPF determines that the first PDU Set is associated with the second PDU Set according to the third indication information, the third association information, and the fourth association information. Exemplarily, when the third indication information is further used to indicate the manner in which the UPF identifies the associated PDU Sets, the UPF identifies that the first PDU Set is associated with the second PDU Set based on the third association information and the fourth association information in the manner indicated by the third indication information. For example, when the third association information is the first RTP timestamp carried by the first PDU Set, the fourth association information is the second RTP timestamp carried by the second PDU Set, and the third indication information indicates that PDU Sets with the same RTP timestamp are associated, when the first RTP timestamp is the same as the second RTP timestamp, the UPF determines that the first PDU Set is associated with the second PDU Set.

[0206] The embodiments of the present application do not limit the specific implementation manner in which the UPF adds association information to the first PDU Set and / or the second PDU Set.

[0207] In a possible implementation, the UPF adds the first association information to the first PDU Set and adds the second association information to the second PDU Set, where the first association information and the second association information are the same, that is, the UPF adds the same association information to the associated first PDU Set and second PDU Set. Exemplarily, the first association information and the second association information may be PDU Set SN, timestamp, or other synchronization identifiers.

[0208] In another possible implementation, the UPF adds association information to the first PDU Set and / or the second PDU Set to indicate the offset value between the identification information of the associated PDU Sets between the first traffic flow and the second traffic flow. The UPF adds association information to the first PDU Set and does not add association information to the second PDU Set. The association information includes the identifier of the second traffic flow and the offset value between the identification information of the associated PDU Sets between the first traffic flow and the second traffic flow. Alternatively, the UPF adds association information to the second PDU Set and does not add association information to the first PDU Set. The association information includes the identifier of the first traffic flow and the offset value between the identification information of the associated PDU Sets between the first traffic flow and the second traffic flow. Alternatively, the UPF adds first association information to the first PDU Set and second association information to the second PDU Set. The first association information includes the identifier of the reference traffic flow and the first offset value, where the first offset value is the offset value between the identification information of the associated PDU Sets between the first traffic flow and the reference traffic flow. The second association information includes the identifier of the reference traffic flow and the second offset value, where the second offset value is the offset value between the identification information of the associated PDU Sets between the second traffic flow and the reference traffic flow. Alternatively, the UPF adds first association information to the first PDU Set and second association information to the second PDU Set. The first association information includes the identifier of the second traffic flow and the offset value between the identification information of the associated PDU Sets between the first traffic flow and the second traffic flow. The second association information includes the identifier of the first traffic flow and the offset value between the identification information of the associated PDU Sets between the first traffic flow and the second traffic flow. Alternatively, the UPF adds first association information to the first PDU Set and second association information to the second PDU Set. The first association information includes the first identification information, and the second association information includes the first identification information, so that the access network device determines that the first PDU Set is associated with the second PDU Set based on the same first identification information carried in the associated first traffic flow and second traffic flow, and synchronously transmits the associated first PDU Set and second PDU Set.

[0209] For the above implementation, the UPF can also add first identification information to the first PDU Set and second identification information to the second PDU Set, where the first identification information is the same as the third association information and the second identification information is the same as the fourth association information. In addition, when the UPF does not receive the offset value between the identification information of the associated PDU Sets between the first traffic flow and the second traffic flow from the SMF, the UPF can also determine the offset value between the identification information of the associated PDU Sets between the first traffic flow and the second traffic flow according to the third association information and the fourth association information.

[0210] When the UPF receives the fourth indication information from the SMF and the fourth indication information indicates the manner of marking the associated PDU Set, the UPF may add association information for the first PDU Set and / or the second PDU Set based on the manner indicated by the fourth indication information.

[0211] Step 208, the UPF sends the first PDU Set of the first service flow and the second PDU Set of the second service flow to the access network device. Correspondingly, the access network device receives the first PDU Set of the first service flow and the second PDU Set of the second service flow from the UPF.

[0212] Among them, association information for determining the association between the first PDU Set and the second PDU Set is added to the first PDU Set and / or the second PDU Set.

[0213] Step 209, the access network device synchronously transmits the first PDU Set and the second PDU Set according to the first indication information and the association information carried in the first PDU Set and / or the second PDU Set.

[0214] Synchronously transmitting the first PDU Set and the second PDU Set can be understood as: the difference in transmission delay between the first PDU Set and the second PDU Set is less than or equal to x ms, where x can be 0 or other values that do not affect the service experience. Alternatively, it can also be understood as: transmitting the first PDU Set and the second PDU Set is completed, that is, the upper bound of the delay from the arrival of the first data of the first PDU Set and the second PDU Set at the access network device side to the completion of the transmission of all data packets or the last data packet of the first PDU Set and the second PDU Set is x ms. That is, x ms is the combined or total transmission delay budget of the first PDU Set and the second PDU Set, and x is a value that does not affect the service experience. Among them, x can be indicated to the access network device by the core network side (such as AF, PCF or SMF, etc.) through the second indication information, can also be pre-configured in the access network device, or can also be determined by the access network device itself, without limitation.

[0215] A possible implementation manner is that when the access network device obtains the second indication information from the SMF, the access network device synchronously transmits the first PDU Set and the second PDU Set according to the first indication information, the association information carried in the first PDU Set and / or the second PDU Set, and the second indication information to meet the synchronization requirements indicated by the second indication information. Optionally, the synchronization requirements indicated by the second indication information can also be configured on the RAN side.

[0216] Embodiments of the present application do not limit the implementation manner in which the access network device synchronously transmits the first PDU Set and the second PDU Set according to the first indication information and the association information carried in the first PDU Set and / or the second PDU Set.

[0217] In a possible implementation manner, the access network device determines that the first service flow is associated with the second service flow according to the first indication information; determines that the first PDU Set is associated with the second PDU Set according to the association information carried in the first PDU Set and / or the second PDU Set; and synchronously transmits the associated first PDU Set and second PDU Set.

[0218] Embodiments of the present application do not limit the specific implementation manner in which the access network device determines that the first PDU Set is associated with the second PDU Set.

[0219] In a possible implementation manner, when the UPF adds the same association information to the associated PDU Sets, the first PDU Set and / or the second PDU Set carry the association information, including: the first PDU Set carries the first association information, and the second PDU Set carries the second association information. When the first association information is the same as the second association information, the access network device determines that the first PDU Set is associated with the second PDU Set. Exemplarily, the first association information and the second association information may be the PDU Set SN, the timestamp, or other synchronization identifiers.

[0220] In another possible implementation manner, when the UPF adds an offset value between the identification information of the PDU Sets used to indicate the association between the first service flow and the second service flow to the first PDU Set and / or the second PDU Set, the association information is the offset value, the first PDU Set carries the first identification information, and the second PDU Set carries the second identification information. When the difference between the first identification information and the second identification information is equal to the offset value indicated by the association information, the access network device determines that the first PDU Set is associated with the second PDU Set.

[0221] The first identification information, the second identification information, and the manner in which the first PDU Set and / or the second PDU Set carry the offset value may refer to step 207.

[0222] It should be noted that the UPF may send the offset value between the identification information of the associated PDU Set between the first service flow and the second service flow to the access network device through the user plane as described in steps 207 and 208, or may also send the offset value between the identification information of the associated PDU Set between the first service flow and the second service flow determined by it to the access network device through the control plane signaling, without limitation. In other words, the offset value may not be carried in the first PDU Set and / or the second PDU Set, and the access network device determines that the first PDU Set and the second PDU Set are associated according to the offset value, the first identification information, and the second identification information received from the control plane. At this time, the first identification information and the second identification information may also be respectively referred to as the first association information and the second association information.

[0223] In method 200, the UPF may identify and add association information to the associated PDU Set in the first service flow and the second service flow. The access network device may determine the associated PDU Set in the first service flow and the second service flow according to the association information added by the UPF, and then perform synchronous transmission on the associated PDU Set, so as to realize the synchronous transmission guarantee of multiple service flows.

[0224] The following combines Figure 3 and Figure 4 to describe in detail the case where multiple service flows that need to be guaranteed for synchronous transmission are transmitted through the same UPF. Figure 3 and Figure 4 The flow description information, synchronization indication information #1, synchronization indication information #2, and synchronization indication information #3 of the multi-modal service flow in

[0225] Figure 3 may correspond to the first indication information above, the synchronization requirement information and the synchronization transmission delay may correspond to the second indication information above, the association identification information #1, the association identification information #2, and the association identification information #3 may correspond to the third indication information above, and the association marking information #1 may correspond to the fourth indication information above.

[0225] Figure 3 FIG. is a schematic flowchart of a communication method 300 provided by an embodiment of the present application.

[0226] In method 300, according to the synchronization assistance information of the AF, the UPF may identify multiple service flows that need to be synchronized and the association relationship of the PDU Set between the multiple service flows, and send them to the access network device after marking the association relationship, and the access network device performs synchronous transmission on the PDU Set with the association relationship, so as to realize the synchronous transmission guarantee of the multi-modal service flow.

[0227] Step 301, the AF sends an AF request message to the PCF. Correspondingly, the PCF receives the AF request message from the AF.

[0228] Among them, the AF request message includes synchronization assistance information. The synchronization assistance information is used for synchronous transmission of multiple service flows.

[0229] The synchronization assistance information may include flow description information of the multi-modal service flow. The flow description information of the multi-modal service flow is used to determine the multi-modal service flows that need to be synchronized. Exemplarily, the flow description information of the multi-modal service flow may include description information such as the IP five-tuple or IP three-tuple corresponding to each multi-modal service flow in the multi-modal service flows that need to be synchronized.

[0230] Optionally, the synchronization assistance information may further include association identification information #1. The association identification information #1 is used for the 5GS (such as UPF or access network device) to determine the association relationship between PDU Sets of multi-modal service flows. Exemplarily, the association identification information #1 may be used to indicate the identification method of the association relationship between PDU Sets of multi-modal service flows, and the specific description may refer to the third indication information in step 201.

[0231] Optionally, the synchronization assistance information may further include synchronization requirement information. The synchronization requirement information is used to characterize the synchronization requirement of the application layer for multi-modal service flows. Exemplarily, the synchronization requirement information may be that the transmission delay difference of the PDU Set granularity of the associated PDU Sets between multi-modal service flows is less than or equal to x ms, or the joint transmission delay budget between the associated PDU Sets of multi-modal service flows is x ms, that is, the associated PDU Sets between multi-modal service flows are transmitted within x ms.

[0232] It should be noted that if the AF is within the trusted domain (for example, the AF is an AF deployed by the operator), the AF can directly interact with the PCF, that is, the AF sends an AF request message to the PCF by invoking the service interface of the PCF, such as the Npcf_PolicyAuthorization service interface. If the AF is within the non-trusted domain (for example, the AF is a third-party AF), the AF interacts with the PCF through the NEF, that is, the AF invokes the service interface of the NEF, such as the Nnef_AFSessionWithQoS service interface, to send an AF request message to the NEF, and then the NEF invokes the service interface of the PCF, such as the Npcf_PolicyAuthorization service interface, to send an AF request message to the PCF.

[0233] It should be noted that this step 301 is optional.

[0234] Step 302, the PCF generates a PCC rule according to the synchronization assistance information in the AF request message. Optionally, the PCF may also generate the PCC rule according to the local policy when generating the PCC rule.

[0235] Among them, the PCC rule may include synchronization indication information #1. The synchronization indication information #1 is used to determine multi-modal service flows that need to be synchronized. Exemplarily, the PCC rule may be a PCC rule at the service flow granularity, and the PCC rule corresponding to each multi-modal service flow that needs to be synchronized may include the same synchronization indication information #1. In other words, the multi-modal service flows corresponding to the PCC rules carrying the synchronization indication information #1 are associated and need to be synchronized. That is, the service flows corresponding to the PCC rules carrying the synchronization indication information #1 are multi-modal service flows for the same service, and association and synchronization processing at the PDU Set granularity are required between these service flows. The embodiments of the present application do not limit the implementation manner of the synchronization indication information #1. For example, the synchronization indication information #1 may be the IP five-tuples or IP three-tuples respectively corresponding to the multi-modal service flows that need to be synchronized. For another example, the synchronization indication information #1 may be multi-modal service identification information or other identification information.

[0236] Optionally, the PCC rule may further include a synchronization requirement. Specifically, the synchronization requirement may be included in the PDU Set QoS parameter, where the PDU Set QoS parameter is a QoS parameter for the PDU Set granularity. The synchronization requirement may include a synchronization transmission delay, and the synchronization transmission delay may be the upper limit of the transmission delay between associated PDU Sets of multi-modal service flows, that is, the joint transmission delay budget between associated PDU Sets of multi-modal service flows, or the transmission delay difference between associated PDU Sets. The synchronization transmission delay may also be described as: the delay requirement for the joint transmission of PDU Sets between multi-modal service flows, or the upper limit of the transmission delay for the PDU Set transmission across multi-modal service flows, or the upper limit of the transmission delay difference for the transmission of associated PDU Sets between multi-modal service flows. The PDU Set QoS parameter may further include other conventional parameters, which will not be elaborated here. The PCC rule may include one or more groups of PDU Set QoS parameters. When the PCC rule does not include the synchronization transmission delay, the access network device can independently determine the synchronization transmission delay between multi-modal service flows. For example, the access network device may transmit the associated PDU Sets strictly according to the same transmission delay. Exemplarily, the access network device ensures that the transmission delay difference between the associated PDU Sets is 0.

[0237] Optionally, the PCC rule may further include association identification information #2. The association identification information #2 is used to indicate the identification method of the association relationship between PDU Sets of multi-modal service flows. For a specific description, reference may be made to the description at the association identification information #1. For example, when there is only one default identification method, the PCC rule may not include the association identification information #2.

[0238] Step 303: When the PDU session establishment or modification process is initiated by the terminal device, the terminal device sends a PDU session establishment request or a PDU session modification request to the AMF, and the AMF forwards the PDU session establishment request or the PDU session modification request to the SMF to trigger the SM (Session Management) policy association establishment or modification process initiated by the SMF.

[0239] Step 303 is an optional step.

[0240] Step 304: The PCF sends PCC rules to the SMF. Correspondingly, the SMF receives the PCC rules from the PCF.

[0241] The PCC rules can be PCC rules at the service flow granularity. In this case, the PCF will send multiple PCC rules to the SMF, and the multiple PCC rules respectively correspond to multiple multi-modal service flows that need to be synchronized. The description of the PCC rules can refer to Step 302.

[0242] A possible implementation: When the PDU session establishment or modification process is initiated by the terminal device, that is, when Step 303 is executed before Step 304, after receiving the PDU session establishment request or the PDU session modification request, the SMF will actively initiate the SM policy association establishment or modification process to obtain PCC rules from the PCF.

[0243] Another possible implementation: The PCF initiates the session management policy association modification process and sends the PCC rules to the SMF, thereby triggering the PDU session modification process. In this case, Step 303 may not be executed.

[0244] Step 305: The SMF provides N4 rules to the UPF through the N4 session establishment or modification process according to the received PCC rules. Optionally, the SMF can also act according to local policies when providing N4 rules to the UPF.

[0245] Among them, the N4 rules may include synchronization indication information #2. The synchronization indication information #2 is used to determine the multi-modal service flows that need to be synchronized. The embodiments of the present application do not limit the implementation manner of the synchronization indication information #2. For example, the synchronization indication information #2 may be the IP five-tuple or IP three-tuple information corresponding to the multi-modal service flows that need to be synchronized, or the SDF template information corresponding to the multi-modal service flows. Another example, the synchronization indication information #2 may be multi-modal service identification information or other identification information. Another example, the synchronization indication information #2 may be the QFI of the multi-modal service flows that need to be synchronized.

[0246] Synchronization indication information #1 and synchronization indication information #2 can be the same or different. For example, synchronization indication information #1 can be the IP five-tuples or IP three-tuples corresponding to the multi-modal service flows that need to be synchronized, and synchronization indication information #2 can be the QFI of the multi-modal service flows that need to be synchronized. For example, both synchronization indication information #1 and synchronization indication information #2 are multi-modal service identification information or other identification information.

[0247] It should be noted that when the multi-modal service flows that need to be synchronized are service flows sent to multiple terminal devices, that is, when multiple service flows of multiple terminal devices need to be synchronized, synchronization indication information #2 also includes information that uniquely identifies the terminal device, such as the identifier of the PDU session of the terminal device and / or the identifier of the terminal device.

[0248] Optionally, the N4 rule may further include association identification information #3. The association identification information #3 is used to indicate the identification method of the association relationship between PDU Sets of multi-modal service flows. For specific descriptions, reference can be made to the description at association identification information #1. For example, when there is only one default identification method or the identification method is pre-provisioned on the UPF side, the N4 rule may not include the association identification information #3.

[0249] Optionally, the N4 rule may further include association marking information #1. The association marking information #1 is used to indicate the marking method of the associated PDU Sets of multi-modal service flows. The marking method may include at least one of the following: adding the same PDU Set SN to the associated PDU Sets, or adding the same synchronization mark to the associated PDU Sets. For example, when there is only one default marking method, the N4 rule may not include the association marking information #1. This synchronization mark may be a synchronization identification mark other than the PDU Set SN.

[0250] It should be noted that the association identification information #3 and the association marking information #1 can be one piece of information or two independent pieces of information.

[0251] Step 306, the SMF sends an N2 session management message to the access network device according to the received PCC rule. Optionally, the SMF may also follow local policies when sending the N2 session management message to the access network device.

[0252] Among them, the N2 session management message is specifically an N2 session management message sent by the SMF to the RAN through the AMF. Exemplarily, the SMF can call Namf_Communication_N1N2MessageTransfer to send this information to the AMF side, and then the AMF sends it to the RAN side through an N2 session request message.

[0253] Among them, the N2 session management message includes PDU Set QoS parameters and synchronization indication information #3.

[0254] The PDU Set QoS parameter is a QoS parameter for the PDU Set granularity.

[0255] The synchronization indication information #3 is used to determine the multi-modal service flows that need to be synchronized. Embodiments of the present application do not limit the implementation manner of the synchronization indication information #3. For example, the synchronization indication information #3 may be multi-modal service identification information or other identification information. For another example, the synchronization indication information #3 may be the QFI of the multi-modal service flows that need to be synchronized.

[0256] It should be noted that when the multi-modal service flows that need to be synchronized are service flows sent to multiple terminal devices, that is, when multiple service flows of multiple terminal devices need to be synchronized, the synchronization indication information #3 further includes information that uniquely identifies the terminal device, such as the identifier of the PDU session of the terminal device and / or the identification information of the terminal device.

[0257] Optionally, the PDU Set QoS parameter may further include a synchronization transmission delay, which may be the upper limit of the transmission delay between associated PDU Sets of multi-modal service flows, or the joint transmission delay budget between associated PDU Sets, or the transmission delay difference between associated PDU Sets. The synchronization transmission delay may also be described as: the delay requirement for joint transmission of PDU Sets between multi-modal service flows, or the upper limit of the transmission delay for transmitting associated PDU Sets across multi-modal service flows, or the upper limit of the transmission delay difference for transmitting associated PDU Sets between multi-modal service flows. When the PDU Set QoS parameter does not include the synchronization transmission delay, when the access network device can autonomously determine the synchronization transmission delay between multi-modal service flows, for example, the access network device can transmit associated PDU Sets strictly according to the same transmission delay.

[0258] Step 307, each network element or device executes the remaining process of the PDU session establishment or modification process. The specific process can refer to the prior art, such as Section 4.3.2.1 of TS23.502, which will not be elaborated here.

[0259] Step 308, when the downlink data packet of the multi-modal service arrives at the UPF, the UPF identifies the multi-modal service flows that need to be synchronized according to the N4 rules from the SMF.

[0260] Specifically, the UPF can identify the multi-modal service flows that need to be synchronized according to the synchronization indication information #2 in the N4 rules.

[0261] Step 309, the UPF performs PDU Set association recognition among multi-modal service flows that need to perform synchronization processing, determines PDU Sets with an association relationship, and marks the PDU Sets with an association relationship.

[0262] In a possible implementation, when the N4 rule includes association recognition information #3, the UPF can perform PDU Set association recognition among multi-modal service flows that need to perform synchronization processing according to the association recognition information #3, and determine PDU Sets with an association relationship.

[0263] For example, when the association recognition information #3 indicates recognition based on the RTP timestamp, the UPF determines that PDU Sets with the same timestamp are associated according to the timestamps carried in the RTP headers of the downstream data packets within each multi-modal service flow.

[0264] For another example, when the association recognition information #3 indicates recognition based on the RTP timestamp difference, the UPF determines that PDU Sets with a timestamp difference within the threshold range are associated according to the timestamps carried in the RTP headers of the downstream data packets within each multi-modal service flow. It should be noted that the threshold range here can be within K1, (0, K1), or (M1, N1), where 0 < M1 < N1.

[0265] For another example, when the association recognition information #3 indicates recognition based on the PDU Set SN, the UPF determines that PDU Sets with the same PDU Set SN are associated according to the PDU Set SN carried in the RTP extension headers of the downstream data packets within each multi-modal service flow.

[0266] For another example, when the association recognition information #3 indicates recognition based on the PDU Set SN offset value, the UPF determines that PDU Sets with a PDU Set SN offset value within the threshold range are associated according to the PDU Set SN carried in the RTP extension headers of the downstream data packets within each multi-modal service flow. It should be noted that the threshold range here can be within K2, (0, K2), or (M2, N2), where 0 < M2 < N2.

[0267] In another possible implementation, when the N4 rule does not include the association recognition information #3, the UPF can perform PDU Set association recognition among multi-modal service flows that need to perform synchronization processing based on a default recognition method. The default recognition method can be the recognition method mentioned above or other recognition methods, without limitation.

[0268] Another possible implementation is that when the N4 rule does not include the association identification information #3, the UPF, based on its internal implementation, performs PDU Set association identification among the multi-modal service flows that require synchronization processing to determine the PDU Sets with an association relationship. The embodiments of the present application do not limit the specific manner of the UPF's internal implementation, which may be the identification manner mentioned above or other identification manners.

[0269] One possible implementation is that when the N4 rule includes the association marking information #1, the UPF can mark the PDU Sets with an association relationship according to the association marking information #1.

[0270] For example, when the association marking information #1 indicates adding the same PDU Set SN to the associated PDU Sets, the UPF adds the same PDU Set SN to the GTP-U header of the downlink data packet corresponding to the associated PDU Sets, so that the access network device can determine the associated PDU Sets based on the same PDU Set SN.

[0271] Another example is that when the association marking information #1 indicates adding the same synchronization mark to the associated PDU Sets, the UPF adds the same synchronization mark to the GTP-U header of the downlink data packet corresponding to the associated PDU Sets, so that the access network device can determine the associated PDU Sets based on the same synchronization mark.

[0272] Another possible implementation is that when the N4 rule does not include the association marking information #1, the UPF can mark the PDU Sets with an association relationship based on the default marking method. The default marking method can be the marking method mentioned above or other marking methods, without limitation.

[0273] Another possible implementation is that when the N4 rule does not include the association marking information #1, the UPF can mark the PDU Sets with an association relationship based on its internal implementation. The embodiments of the present application do not limit the specific manner of the UPF's internal implementation, which may be the marking method mentioned above or other marking methods.

[0274] In addition, at the UPF, the downlink data packets can also be identified to determine and mark the downlink data packets belonging to the same PDU Set.

[0275] Step 310, the UPF sends the marked downlink data packets to the access network device. Correspondingly, the access network device receives the downlink data packets from the UPF.

[0276] Step 311, the access network device determines the multi-modal service flows that need to be synchronized according to the synchronization indication information #3 from the SMF.

[0277] Step 312, the access network device synchronously transmits the PDU Sets carrying the same PDU Set SN or synchronization mark in the multi-modal service flow.

[0278] A possible implementation manner is that when the PUD set QoS parameter includes the synchronization transmission delay, the access network device synchronously transmits the PDU Sets carrying the same PDU Set SN or synchronization mark in the multi-modal service flow based on the synchronization transmission delay in the PUD set QoS parameter.

[0279] Another possible implementation manner is that when the PUD set QoS parameter does not include the synchronization transmission delay, when the access network device autonomously determines that it can determine the synchronization transmission delay between multi-modal service flows. For example, the access network device can strictly transmit the associated PDU Sets according to the same transmission delay.

[0280] Figure 4 It is a schematic flowchart of the communication method 400 provided by the embodiment of the present application.

[0281] In the method 400, the AF or UPF can determine the offset value between the PDU Set SNs corresponding to the PDU Sets with an association relationship among multiple service flows that need to be synchronously processed, and provide it to the access network device. Then, the access network device synchronously transmits the PDU Sets with an association relationship according to the received PDU Set SN offset value, so as to realize the synchronization transmission guarantee of the multi-modal service flow.

[0282] Steps 401 to 405 are the same as steps 301 to 305, and reference can be made to steps 301 to 305, which will not be elaborated here.

[0283] Step 406, the SMF sends an N2 session management message to the access network device according to the received PCC rule. Optionally, the SMF can also follow the local policy when sending the N2 session management message to the access network device.

[0284] Among them, the N2 session management message is specifically an N2 session management message sent by the SMF to the RAN through the AMF. Exemplarily, the SMF can call Namf_Communication_N1N2MessageTransfer to send this information to the AMF side, and then the AMF sends it to the RAN side through the N2 session request message.

[0285] Among them, the N2 session management message includes the PDU Set QoS parameter and the synchronization indication information #3.

[0286] The PDU Set QoS parameter is a QoS parameter for the PDU Set granularity.

[0287] The synchronization indication information #3 is used to determine the multi-modal service flows that need to be synchronized. Embodiments of the present application do not limit the implementation manner of the synchronization indication information #3. For example, the synchronization indication information #3 may be multi-modal service identification information or other identification information. For another example, the synchronization indication information #3 may be the QFI of the multi-modal service flows that need to be synchronized.

[0288] It should be noted that when the multi-modal service flows that need to be synchronized are service flows sent to multiple terminal devices, that is, when multiple service flows of multiple terminal devices need to be synchronized, the synchronization indication information #3 further includes information that uniquely identifies the terminal device, such as the identifier of the PDU session of the terminal device and / or the identification information of the terminal device.

[0289] Optionally, the PDU Set QoS parameter may further include a synchronization transmission delay. The synchronization transmission delay may be the upper limit of the transmission delay between associated PDU Sets of multi-modal service flows, or the joint transmission delay budget between associated PDU Sets, or the transmission delay difference between associated PDU Sets. The synchronization transmission delay may also be described as: the delay requirement for the joint transmission of PDU Sets between multi-modal service flows, or the upper limit of the transmission delay for the transmission of associated PDU Sets across multi-modal service flows, or the upper limit of the transmission delay difference for the transmission of associated PDU Sets between multi-modal service flows. When the PDU Set QoS parameter does not include the synchronization transmission delay, when the access network device can autonomously determine the synchronization transmission delay between multi-modal service flows, for example, the access network device can transmit the associated PDU Sets strictly according to the same transmission delay.

[0290] Optionally, the N2 session management message may further include a PDU Set SN offset value. The PDU Set SN offset value here refers to the offset value between the PDU Set SNs corresponding to the associated PDU Sets of different service flows. Exemplarily, in the case where the application server uses an RTP extension header carrying the PDU Set SN or other protocol headers carrying the PDU Set SN or the synchronization identifier, the AF can determine the offset value between the PDU Set SNs corresponding to the associated PDU Sets of the multi-modal service flows that need to be synchronized, and provide it to the access network device through the PCF and the SMF.

[0291] Embodiments of the present application do not limit the setting manner of the PDU Set SN offset value.

[0292] As an example, the PDU Set SN offset value of a certain service flow can be the offset value relative to the PDU Set SN corresponding to the PDU Set of the reference flow, and the reference flow can be one of the multi-modal service flows that need to be synchronized. For example, the multi-modal service flows that need to be synchronized are service flow #1, service flow #2, and service flow #3. Taking service flow #1 as the reference flow, PDU Set A in service flow #1, PDU Set B in service flow #2, and PDU Set C in service flow #3 are associated. The PDU Set SN in the RTP header corresponding to PDU Set A is 10, the PDU Set SN in the RTP header corresponding to PDU Set B is 15, and the PDU Set SN in the RTP header corresponding to PDU Set C is 12. Then, the PDU Set SN offset value in the PDU Set QoS parameter of service flow #1 is 0, the PDU Set SN offset value in the PDU Set QoS parameter of service flow #2 is 5, and the PDU Set SN offset value in the PDU Set QoS parameter of service flow #3 is 2. Note that it is assumed here that the UPF copies the PDU Set SN in the RTP header when adding the PDU Set SN. If there is a data packet in the QoS flow that does not carry the PDU Set SN, then when the UPF adds the PDU Set SN to the data packet, it will update the PDU Set SN offset value accordingly.

[0293] As another example, the PDU Set SN offset value of a certain service flow may include the offset value of the PDU Set SN of this service flow relative to the PDU Set of each other service flow that needs to be synchronized. For example, there are service flow #1, service flow #2, and service flow #3 as multi-modal service flows that need to be synchronized. PDU Set A in service flow #1, PDU Set B in service flow #2, and PDU Set C in service flow #3 are associated. The PDU Set SN in the RTP header corresponding to PDU Set A is 10, the PDU Set SN in the RTP header corresponding to PDU Set B is 15, and the PDU Set SN in the RTP header corresponding to PDU Set C is 12. Then, the PDU Set QoS parameter of service flow #1 may include the offset value of the PDU Set SN relative to service flow #2 (i.e., 5) and the offset value of the PDU Set SN relative to service flow #3 (i.e., 2). The PDU Set QoS parameter of service flow #2 may include the offset value of the PDU Set SN relative to service flow #1 (i.e., 5) and the offset value of the PDU Set SN relative to service flow #3 (i.e., 3). The PDU Set QoS parameter of service flow #3 may include the offset value of the PDU Set SN relative to service flow #1 (i.e., 2) and the offset value of the PDU Set SN relative to service flow #2 (i.e., 3). Note that it is assumed here that the UPF copies the PDU Set SN in the RTP header when adding the PDU Set SN. If there is a data packet in this QoS flow that does not carry the PDU Set SN, then when the UPF adds the PDU Set SN to this data packet, it will update the PDU Set SN offset value accordingly.

[0294] Step 407, each network element or device executes the remaining process of the PDU session establishment or modification process. The specific process can refer to the prior art, such as Section 4.3.2.1 of TS23.502, which will not be elaborated here.

[0295] Subsequently, there can be two ways to transmit the downlink data packets of the multi-modal service, which are introduced separately below.

[0296] Method A: Step 408 to Step 411

[0297] Step 408, when the downlink data packet of the multi-modal service arrives at the UPF, the UPF identifies the multi-modal service flows that need to be synchronized according to the N4 rules from the SMF.

[0298] Specifically, the UPF can identify the multi-modal service flows that need to be synchronized according to the synchronization indication information #2 in the N4 rules.

[0299] Step 409: The UPF performs PDU Set association recognition among multi-modal service flows that require synchronization processing, determines the PDU Sets with an association relationship, and identifies the offset value of the PDU Set SN corresponding to the PDU Sets with an association relationship. The setting method of the PDU Set SN offset value can refer to Step 406.

[0300] The implementation method for the UPF to perform PDU Set association recognition among multi-modal service flows that require synchronization processing and determine the PDU Sets with an association relationship can refer to Step 309 and will not be elaborated here.

[0301] Step 410: The UPF adds the PDU Set SN to the GTP-U header of the downlink data packet based on the existing method. The UPF can also add the offset value of the PDU Set SN to the GTP-U header of the downlink data packet so that the access network device can determine the associated PDU Set based on the offset value of the PDU Set SN. In other words, the UPF can send the PDU Set SN offset value to the access network device through the user plane along with the downlink data packet in the GTP-U header. For example, if there is a data packet in the QoS flow that does not carry the PDU Set SN, then when the UPF adds the PDU Set SN to this data packet, it will correspondingly update the PDU Set SN offset value.

[0302] In addition, the UPF can also send the determined PDU Set SN offset value to the access network device through the control plane, that is, via the SMF, so that the access network device can determine the associated PDU Set based on the offset value of the PDU Set SN.

[0303] Figure 4 Taking the example of sending the PDU Set SN offset value to the access network device through the GTP-U header of the downlink data packet.

[0304] Step 411: The UPF sends the downlink data packet to the access network device. Correspondingly, the access network device receives the downlink data packet from the UPF.

[0305] Among them, the GTP-U header of the downlink data packet includes the PDU Set SN offset value.

[0306] In Method A, the UPF determines the offset value of the PDU Set SN corresponding to the associated PDU Sets among the multi-modal service flows that require synchronization processing and provides it to the access network device.

[0307] Method B: Steps 412 to 414

[0308] Step 412: When the downlink data packet of the multimodal service arrives at the UPF, the UPF identifies the multimodal service flow that needs to be synchronized according to the N4 rule from the SMF.

[0309] Specifically, the UPF can identify the multimodal service flow that needs to be synchronized according to the synchronization indication information #2 in the N4 rule.

[0310] Step 413: Optionally, the UPF copies the PDU Set SN in the RTP header of the downlink data packet and adds it to the GTP-U header of the downlink data packet.

[0311] Step 414: The UPF sends the downlink data packet to the access network device. Correspondingly, the access network device receives the downlink data packet from the UPF.

[0312] Among them, the GTP-U header of the downlink data packet includes the PDU Set SN in the RTP header.

[0313] Method B can be applied to the scenario where the application server uses the RTP extension header carrying the PDU Set SN. In this scenario, the AF can determine the offset value between the PDU Set SNs corresponding to the associated PDU Sets of the multimodal service flows that need to be synchronized, and provide it to the access network device through the PCF and the SMF. For example, the UPF provides the PDU Set SN offset value to the access network device through steps 401 to 406.

[0314] In addition, at the UPF, the downlink data packet can also be identified to determine and mark the downlink data packets belonging to the same PDU Set.

[0315] Subsequently, steps 415 to 416 can be executed.

[0316] Step 415: The access network device determines the multimodal service flow that needs to be synchronized according to the synchronization indication information #3 from the SMF.

[0317] Step 416: The access network device performs PDU Set association identification between the multimodal service flows that need to be synchronized according to the PDU Set SN offset value from the UPF, determines the PDU Sets with an association relationship, and synchronously transmits the PDU Sets with an association relationship.

[0318] Among them, the PDU Set SN offset value used by the access network device can be provided by the UPF or by the AF.

[0319] Scenario 2: Multiple service flows that require synchronous transmission guarantee are transmitted through multiple UPFs

[0320] Figure 5 It is a schematic flowchart of the communication method 500 provided by an embodiment of the present application.

[0321] The method 500 can be executed by an access network device, a UPF, an SMF, a PCF, and / or an AF. Without special instructions, "access network device", "UPF", "SMF", "PCF", or "AF" can refer to the access network device, UPF, SMF, PCF, or AF itself, or can refer to a device capable of supporting the access network device, UPF, SMF, PCF, or AF to implement its functions. For the convenience of description, the access network device, UPF, SMF, PCF, or AF will be uniformly used to describe hereinafter.

[0322] The method 500 includes at least some of the following content.

[0323] Optionally, in step 501, the AF determines synchronization assistance information.

[0324] Among them, the synchronization assistance information is used for synchronous transmission of a first service flow and a second service flow. The first service flow and the second service flow are transmitted through different UPFs.

[0325] The synchronization assistance information may include first indication information. The first indication information is used to indicate that the first service flow and the second service flow are associated. The first service flow and the second service flow are associated, that is, the first service flow and the second service flow need to perform synchronous transmission guarantee.

[0326] Optionally, the synchronization assistance information may further include second indication information. The second indication information is used to indicate the synchronization requirement between the first service flow and the second service flow.

[0327] The description of the service flow that needs to perform synchronous transmission guarantee, the first indication information, and the second indication information can refer to step 201.

[0328] The synchronization assistance information may further include fifth indication information. The fifth indication information is used to indicate the association information added by the UPF to the first service flow. This association information can be used to determine the associated PDU Set between the first service flow and the second service flow.

[0329] A possible implementation manner is that the fifth indication information includes a third timestamp corresponding to the first service flow and a third PDU Set SN corresponding to the third timestamp. Exemplarily, the third PDU Set SN corresponding to the third timestamp may be the PDU Set SN that the UPF needs to add to the PDU Set with the third timestamp.

[0330] In another possible implementation manner, the fifth indication information includes the offset value of the PDU Set SN corresponding to the first service flow. The offset value of the PDU Set SN corresponding to the first service flow is the offset value of the PDU Set SN added by the UPF for the PDU Set of the first service flow relative to the PDU Set SN added by the AS for the PDU Set of the first service flow.

[0331] Optionally, the synchronization assistance information may further include period information. The period information is used to indicate the time interval between two adjacent PDU Sets of the first service flow.

[0332] Optionally, in step 502, the AF sends the synchronization assistance information to the PCF. Correspondingly, the PCF receives the synchronization assistance information from the AF.

[0333] In step 503, the PCF sends the first indication information and the fifth indication information to the SMF according to the received synchronization assistance information. Correspondingly, the SMF receives the first indication information and the fifth indication information from the PCF.

[0334] Optionally, when the synchronization assistance information further includes the second indication information or the period information, the PCF also sends the second indication information or the period information to the SMF. Correspondingly, the SMF also receives the second indication information or the period information from the PCF.

[0335] If the PCF does not receive the synchronization assistance information from the AF side, the synchronization assistance information may be from the local configuration on the PCF side. That is, the PCF generates the above first indication information, second indication information, fifth indication information, or period information by itself.

[0336] In step 504, the SMF sends the fifth indication information to the UPF according to the information received from the PCF. Correspondingly, the UPF receives the fifth indication information from the SMF.

[0337] Optionally, when the SMF also receives the period information, the SMF also sends the period information to the UPF. Correspondingly, the UPF also receives the period information from the SMF.

[0338] It should be noted that the form of the fifth indication information or the period information sent by the SMF to the UPF may be the same as or different from the fifth indication information or the period information received by the SMF from the PCF, without limitation.

[0339] In step 505, the SMF sends the first indication information to the access network device. Correspondingly, the access network device receives the first indication information from the SMF.

[0340] Optionally, when the SMF also receives the second indication information, the SMF also sends the second indication information to the access network device. Correspondingly, the access network device also receives the second indication information from the SMF.

[0341] It should be noted that the form of the first indication information or the second indication information sent by the SMF to the UPF may be the same as or different from the first indication information or the second indication information received by the SMF from the PCF, without limitation.

[0342] It should be noted that Figure 5 The PCF, SMF, and UPF shown correspond to the first traffic flow. The above only describes the control plane signaling interaction for the first traffic flow. For the control plane signaling interaction of the second traffic flow, reference can be made to steps 502 to 505, which will not be elaborated here. The fifth indication information for the second traffic flow is used to indicate the association information added by the UPF to the second traffic flow.

[0343] Step 506, the UPF receives the first PDU Set of the first traffic flow.

[0344] Among them, the first PDU Set carries the third association information. Exemplarily, the third association information is the first PDU Set SN or the first RTP timestamp carried by the first PDU Set.

[0345] Step 507, the UPF adds the first association information to the first PDU Set according to the fifth indication information and the third association information.

[0346] A possible implementation manner is that the UPF adds the first association information to the GTP-U layer of the first PDU Set, such as in the GTP-U header. The information in the GTP-U layer is information that the access network device can obtain. Therefore, the access network device can determine the PDU Set associated with the first PDU Set based on the first association information added by the UPF to the first PDU Set.

[0347] The embodiments of the present application do not limit the implementation manner in which the UPF adds the first association information to the first PDU Set according to the fifth indication information and the third association information.

[0348] A possible implementation is that when the fifth indication information includes the third timestamp corresponding to the first traffic flow, the third PDU Set SN corresponding to the third timestamp, and the first PDU Set carries the first timestamp, the UPF adds the first PDU Set SN to the first PDU Set according to the third timestamp, the third PDU Set SN, and the first timestamp. When the UPF obtains the periodic information, the UPF adds the first PDU Set SN to the first PDU Set according to the third timestamp, the third PDU Set SN, the first timestamp, and the periodic information.

[0349] For example, the third timestamp is 10:00:00, the third PDU Set SN is 10, the periodic information indicates that the time interval between two adjacent PDU Sets of the first traffic flow is 2s, the first timestamp carried by the first PDU Set is 10:00:04, and the first PDU Set is the second PDU Set after the third timestamp. Therefore, the first PDU Set SN added by the UPF to the first PDU Set can be 12.

[0350] Another possible implementation is that when the fifth indication information includes the offset value of the PDU Set SN corresponding to the first traffic flow and the first PDU Set carries the fourth PDU Set SN, the UPF adds the first PDU Set SN to the PDU Set according to the offset value in the fifth indication information and the fourth PDU Set SN, and the first PDU Set SN is offset by the offset value in the fifth indication information relative to the fourth PDU Set SN.

[0351] For example, the offset value in the fifth indication information is 5, the fourth PDU Set SN carried by the first PDU Set is 12, and the first PDU Set SN added by the UPF to the first PDU Set can be 17.

[0352] It should be noted that only the method for the UPF to add the first association information to the first PDU Set of the first traffic flow is described above. The method for the UPF of the second traffic flow to add the second association information to the second PDU Set of the second traffic flow can refer to steps 506 to 507 and will not be elaborated here.

[0353] Step 508, the UPF sends the first PDU Set of the first traffic flow to the access network device. Correspondingly, the access network device receives the first PDU Set of the first traffic flow from the UPF.

[0354] Among them, the first association information used to determine the association between the first PDU Set and the second PDU Set is added to the first PDU Set.

[0355] Step 509, the access network device receives a second PDU Set from the UPF of the second service flow.

[0356] Among them, second association information for determining the association between the first PDU Set and the second PDU Set is added to the second PDU Set.

[0357] Step 510, the access network device synchronously transmits the first PDU Set and the second PDU Set according to the first indication information, the first association information carried by the first PDU Set, and the second association information carried by the second PDU Set.

[0358] Synchronously transmitting the first PDU Set and the second PDU Set can be understood as follows: the difference in transmission delay between the first PDU Set and the second PDU Set is less than or equal to x ms, where x can be 0 or other values that do not affect the service experience. Or it can also be understood as: transmitting the first PDU Set and the second PDU Set is completed, that is, the upper bound of the delay from the arrival of the first data of the first PDU Set and the second PDU Set at the access network device side to the completion of the transmission of all data packets or the last data packet of the first PDU Set and the second PDU Set is x ms. That is, x ms is the combined or total transmission delay budget of the first PDU Set and the second PDU Set, and x is a value that does not affect the service experience. Among them, x can be indicated to the access network device by the core network side (such as AF, PCF, or SMF, etc.) through the second indication information, can be pre-configured in the access network device, or can also be determined by the access network device itself, without limitation.

[0359] A possible implementation manner is that when the access network device obtains the second indication information from the SMF, the access network device synchronously transmits the first PDU Set and the second PDU Set according to the first indication information, the first association information carried by the first PDU Set, the second association information carried by the second PDU Set, and the second indication information to meet the synchronization requirements indicated by the second indication information. Optionally, the synchronization requirements indicated by the second indication information can also be configured on the RAN side.

[0360] The embodiments of this application do not limit the implementation manner in which the access network device synchronously transmits the first PDU Set and the second PDU Set according to the first indication information, the first association information carried by the first PDU Set, and the second association information carried by the second PDU Set.

[0361] In a possible implementation, the access network device determines that a first traffic flow is associated with a second traffic flow according to first indication information; determines that a first PDU Set is associated with a second PDU Set according to first association information carried in the first PDU Set and second association information carried in the second PDU Set; and synchronously transmits the associated first PDU Set and second PDU Set.

[0362] Embodiments of this application do not limit the specific implementation for the access network device to determine the association between the first PDU Set and the second PDU Set. In a possible implementation, when the first association information is the same as the second association information, the access network device determines that the first PDU Set is associated with the second PDU Set.

[0363] In method 500, the AF may indicate to the UPF the association information added for the traffic flow, so that the UPF can add association information to the PDU Set based on the association information indicated by the AF. Based on this, the UPF corresponding to the first traffic flow and the UPF corresponding to the second traffic flow can ensure that the PDU Sets associated between the first traffic flow and the second traffic flow carry the same association information, and the access network device can synchronously transmit the PDU Sets carrying the same association information, thereby realizing the synchronous transmission guarantee of multiple traffic flows.

[0364] The following combines Figure 6 to describe method 500 in detail.

[0365] Figure 6 is a schematic flowchart of a communication method 600 provided by an embodiment of this application.

[0366] Figure 6 The association tag information #A, association tag information #B, and association tag information #C in [[ ]] can correspond to the fifth indication information above, the synchronization indication information #3 can correspond to the first indication information above, and the synchronous transmission delay can correspond to the second indication information above.

[0367] In method 600, the UPF needs to add a PDU Set SN or a synchronization identifier to the downlink data packet according to specific rules, so as to ensure that the PDU Sets associated between multiple traffic flows that need to be synchronously transmitted carry the same PDU Set SN or synchronization identifier, so that the access network device can synchronously transmit the PDU Sets carrying the same PDU Set SN or synchronization identifier, thereby realizing the synchronous transmission guarantee of multi-modal traffic flows.

[0368] Step 601, the AF sends an AF request message to the PCF. Correspondingly, the PCF receives the AF request message from the AF.

[0369] Among them, the AF request message includes synchronization assistance information. The synchronization assistance information is used for synchronous transmission of multiple service flows.

[0370] Step 601 may refer to step 301. Different from step 301, the synchronization assistance information in step 601 includes association tag information #A.

[0371] In a possible implementation, the association tag information #A may include the RTP timestamp and the PDU Set SN or synchronization tag corresponding to the RTP timestamp. In this case, when receiving a downlink data packet carrying the RTP timestamp, the UPF may add the PDU Set SN or synchronization tag corresponding to the RTP timestamp to the GTP-U header of the downlink data packet.

[0372] In another possible implementation, the association tag information #A may include a PDU Set SN offset value. The PDU Set SN offset value may refer to the difference between the PDU Set SN carried in the RTP extension header of the downlink data packet and the PDU Set SN added to the GTP-U header of the downlink data packet. In this case, when receiving a downlink data packet carrying the PDU Set SN, the UPF may determine the PDU Set SN to be added to the GTP-U header of the downlink data packet according to the PDU Set SN carried in the RTP extension header and the PDU Set SN offset value.

[0373] Before sending the AF request message to the PCF, the AF may determine or coordinate the association relationship between the RTP timestamp and the PDU Set SN or synchronization tag corresponding to the RTP timestamp, or determine the PDU Set SN offset value corresponding to each multi-modal service flow in the multi-modal service flows that need to be synchronously processed.

[0374] Step 602: The PCF generates a PCC rule according to the synchronization assistance information in the AF request message. Optionally, the PCF may also generate the PCC rule according to local policies when generating the PCC rule.

[0375] Step 602 may refer to step 302. Different from step 302, the PCC rule includes association tag information #B, which may include the RTP timestamp and the PDU Set SN or synchronization tag corresponding to the RTP timestamp, or include a PDU Set SN offset value. The description of the association tag information #B may refer to the association tag information #A.

[0376] Steps 603 and 604 may refer to steps 303 and 304, and will not be elaborated here.

[0377] Step 605: The SMF provides N4 rules to the UPF through the N4 session establishment or modification process according to the received PCC rules. Optionally, the SMF may also act according to local policies when providing N4 rules to the UPF.

[0378] Among them, the N4 rules may include associated marking information #C. The associated marking information #C may include the RTP timestamp and the PDU Set SN or synchronization mark corresponding to the RTP timestamp, or include the PDU Set SN offset value. The description of the associated marking information #C may refer to the associated marking information #A.

[0379] It should be noted that when multi-modal service flows that require synchronous transmission are transmitted through multiple UPFs (such as Figure 6 UPF #1 and UPF #2 in), the AF may, in the manner shown in steps 601 to 605, provide N4 rules carrying the associated marking information #C to the multiple UPFs respectively. Among them, for the case where the associated marking information #C includes the RTP timestamp and the PDU Set SN or synchronization mark corresponding to the RTP timestamp, the N4 rules of multiple service flows may carry the same associated marking information #C. For the case where the associated marking information #C includes the PDU Set SN offset value, the N4 rule of each service flow among the multiple service flows includes the PDU Set SN offset value corresponding to the service flow. In other words, the associated marking information #C in the N4 rules of multiple service flows may be different.

[0380] Steps 606 and 607 may refer to steps 306 and 307 and will not be elaborated here.

[0381] After multiple UPFs receive the downlink data packets, each UPF may add a PDU Set SN or synchronization mark to the downlink data packets in the manner of steps 608 and 609 and send the downlink data packets with the added PDU Set SN or synchronization mark to the access network device. Steps 608 and 609 are as follows.

[0382] Step 608: When the downlink data packet of the multi-modal service arrives at the UPF, the UPF adds a PDU Set SN or synchronization mark to the downlink data packet according to the N4 rule from the SMF.

[0383] A possible implementation is that when the N4 rule includes the associated marking information #C, and the associated marking information #C includes the RTP timestamp and the PDU Set SN or synchronization mark corresponding to the RTP timestamp, the UPF determines the PDU Set SN or synchronization mark corresponding to the PDU Set to which the downlink data packet belongs according to the timestamp in the RTP header of the downlink data packet, the RTP timestamp in the associated marking information #C, and the correspondence between the RTP timestamp in the associated marking information #C and the PDU Set SN or synchronization mark, and adds the determined PDU Set SN or synchronization mark to the GTP-U header of the downlink data packet.

[0384] Another possible implementation is that when the N4 rule includes the associated marking information #C, and the associated marking information #C includes the PDU Set SN offset value, the UPF determines the PDU Set SN corresponding to the PDU Set to which the downlink data packet belongs according to the PDU Set SN in the RTP header of the downlink data packet and the PDU Set SN offset value in the associated marking information #C, and adds the determined PDU Set SN to the GTP-U header of the downlink data packet. For example, if the PDU Set SN in the RTP header of the downlink data packet is 10 and the PDU Set SN offset value in the associated marking information #C is 5, then the PDU Set SN corresponding to the PDU Set to which the downlink data packet belongs is 15.

[0385] Another possible implementation is that when the N4 rule does not include the associated marking information #C, the UPF adds a PDU Set SN or synchronization mark to the downlink data packet based on its internal implementation. The embodiments of the present application do not limit the specific manner of the UPF's internal implementation, which may be the manner mentioned above or other manners.

[0386] In addition, at the UPF, the downlink data packets can also be identified to determine and mark the downlink data packets belonging to the same PDU Set.

[0387] Step 609, the UPF sends the downlink data packet to the access network device. Correspondingly, the access network device receives the downlink data packet from the UPF.

[0388] Step 610, the access network device determines the multi-modal service flow that needs to be synchronized according to the synchronization indication information #3 from the SMF.

[0389] Step 611, the access network device synchronously transmits the PDU Sets carrying the same PDU Set SN or synchronization mark in the multi-modal service flow.

[0390] Figure 5 and Figure 6The method shown realizes the synchronous transmission of multiple service flows in Scenario 2 by indicating to the UPF the association information to be added to the service flow. In this application, the synchronous transmission of multiple service flows in Scenario 2 can also be realized by the access network device performing the identification of the associated PDU Set and the UPF not performing the identification of the associated PDU Set. The following describes this method.

[0391] Figure 7 It is a schematic flowchart of a communication method 700 provided by an embodiment of this application.

[0392] Method 500 can be executed by an access network device, UPF, SMF, PCF, and / or AF. Without special instructions, "access network device", "UPF", "SMF", "PCF", or "AF" can refer to the access network device, UPF, SMF, PCF, or AF itself, or can refer to a device capable of supporting the access network device, UPF, SMF, PCF, or AF to implement its functions. For the convenience of description, the access network device, UPF, SMF, PCF, or AF will be uniformly used to describe below.

[0393] Method 700 includes at least some of the following content.

[0394] Optionally, in step 701, the AF determines synchronization assistance information.

[0395] Among them, the synchronization assistance information is used for the synchronous transmission of the first service flow and the second service flow. The first service flow and the second service flow are transmitted through different UPFs.

[0396] The synchronization assistance information may include first indication information. The first indication information is used to indicate that the first service flow and the second service flow are associated. The first service flow and the second service flow being associated means that the first service flow and the second service flow need to perform synchronous transmission guarantee.

[0397] Optionally, the synchronization assistance information may further include second indication information. The second indication information is used to indicate the synchronization requirement between the first service flow and the second service flow.

[0398] The description of the service flow that needs to perform synchronous transmission guarantee, the first indication information, and the second indication information can refer to step 201.

[0399] Optionally, the synchronization assistance information may further include sixth indication information. The sixth indication information is used to indicate that the UPF adds the association information carried in the PDU Set to the GTP-U header.

[0400] Optionally, in step 702, the AF sends the synchronization assistance information to the PCF. Correspondingly, the PCF receives the synchronization assistance information from the AF.

[0401] Step 703: The PCF sends a first indication message to the SMF according to the received synchronization assistance information. Correspondingly, the SMF receives the first indication message from the PCF.

[0402] Optionally, when the synchronization assistance information further includes a second indication message or a sixth indication message, the PCF further sends the second indication message or the sixth indication message to the SMF. Correspondingly, the SMF further receives the second indication message or the sixth indication message from the PCF.

[0403] Step 704: The SMF sends a sixth indication message to the UPF according to the information received from the PCF. Correspondingly, the UPF receives the sixth indication message from the SMF.

[0404] Step 704 is an optional step.

[0405] It should be noted that the form of the sixth indication message sent by the SMF to the UPF may be the same as or different from the sixth indication message received by the SMF from the PCF, without limitation.

[0406] Step 705: The SMF sends a first indication message to the access network device. Correspondingly, the access network device receives the first indication message from the SMF.

[0407] Optionally, when the SMF further receives a second indication message, the SMF further sends the second indication message to the access network device. Correspondingly, the access network device further receives the second indication message from the SMF.

[0408] It should be noted that the form of the first indication message or the second indication message sent by the SMF to the UPF may be the same as or different from the first indication message or the second indication message received by the SMF from the PCF, without limitation.

[0409] It should be noted that Figure 7 The PCF, SMF, and UPF shown correspond to the first traffic flow. The above only describes the control plane signaling interaction for the first traffic flow. For the control plane signaling interaction of the second traffic flow, reference can be made to Steps 702 to 705, which will not be elaborated here.

[0410] Step 706: The UPF receives the first PDU Set of the first traffic flow.

[0411] Among them, the first PDU Set carries first association information. Exemplarily, the first association information is the first PDU Set SN carried by the first PDU Set or the first RTP timestamp.

[0412] Step 707: The UPF adds the first association information to the GTP-U header of the first PDU Set.

[0413] When the UPF receives the sixth indication information, the UPF may add the first association information to the GTP-U header of the first PDU Set according to the sixth indication information.

[0414] It should be noted that only the method of adding the first association information to the first PDU Set of the first traffic flow by the UPF is described above. The method of adding the second association information to the second PDU Set of the second traffic flow by the UPF of the second traffic flow may refer to steps 706 to 707 and will not be elaborated here.

[0415] Step 708, the UPF sends the first PDU Set of the first traffic flow to the access network device. Correspondingly, the access network device receives the first PDU Set of the first traffic flow from the UPF.

[0416] Among them, the first association information for determining the association between the first PDU Set and the second PDU Set is added to the first PDU Set.

[0417] Step 709, the access network device receives the second PDU Set from the UPF of the second traffic flow.

[0418] Among them, the second association information for determining the association between the first PDU Set and the second PDU Set is added to the second PDU Set.

[0419] Step 710, the access network device synchronously transmits the first PDU Set and the second PDU Set according to the first indication information, the first association information carried by the first PDU Set, and the second association information carried by the second PDU Set.

[0420] A possible implementation manner is that when the access network device obtains the second indication information from the SMF, the access network device synchronously transmits the first PDU Set and the second PDU Set to meet the synchronization requirements indicated by the second indication information according to the first indication information, the first association information carried by the first PDU Set, the second association information carried by the second PDU Set, and the second indication information.

[0421] The embodiments of the present application do not limit the implementation manner of the access network device to synchronously transmit the first PDU Set and the second PDU Set according to the first indication information, the first association information carried by the first PDU Set, and the second association information carried by the second PDU Set.

[0422] In a possible implementation, the access network device determines that a first traffic flow is associated with a second traffic flow according to first indication information; determines that a first PDU Set is associated with a second PDU Set according to first association information carried in the first PDU Set and second association information carried in the second PDU Set; and synchronously transmits the associated first PDU Set and second PDU Set.

[0423] Embodiments of this application do not limit the specific implementation for the access network device to determine the association between the first PDU Set and the second PDU Set. The specific implementation may refer to the manner in which the UPF determines the association between the first PDU Set and the second PDU Set according to the third association information and the fourth association information in step 207. Among them, various information required by the access network device can be obtained from the SMF.

[0424] In method 700, the access network device can perform the identification of the associated PDU Sets, and the UPF does not perform the identification of the associated PDU Sets. The access network device can synchronously transmit the associated PDU Sets, thereby realizing the synchronous transmission guarantee of multiple traffic flows.

[0425] The following combines Figure 8 to describe method 700 in detail.

[0426] Figure 8 is a schematic flowchart of a communication method 800 provided by an embodiment of this application.

[0427] Figure 8 The association marking information #D in [[ ]] can correspond to the sixth indication information above, the synchronization indication information #3 can correspond to the first indication information above, and the synchronous transmission delay can correspond to the second indication information above.

[0428] In method 800, according to the synchronization assistance information of the AF, the access network device can identify multiple traffic flows that need to be synchronized and the association relationship between the PDU Sets of the multiple traffic flows, and synchronously transmit the PDU Sets with an association relationship, thereby realizing the synchronous transmission guarantee of multi-modal traffic flows.

[0429] Steps 801 to 804 are the same as steps 301 to 304. Reference can be made to steps 301 to 304 and will not be elaborated here.

[0430] Step 805, the SMF provides N4 rules to the UPF through the N4 session establishment or modification process according to the received PCC rules. Optionally, the SMF can also follow local policies when providing N4 rules to the UPF.

[0431] Optionally, the N4 rule may include associated marking information #D. The associated marking information #D is used to instruct the UPF to add the timestamp or PDU Set SN in the RTP header of the downlink data packet to the GTP-U header of the downlink data packet. Exemplarily, when there is only one default marking method, the N4 rule may not include the associated marking information #D.

[0432] It should be noted that when multi-modal traffic flows that require synchronous transmission are transmitted through multiple UPFs (such as Figure 8 the UPF #1 and UPF #2 in), the AF can provide the N4 rules carrying the associated marking information #D to the multiple UPFs respectively in the manner shown in steps 801 to 805.

[0433] Step 806, the SMF sends an N2 session management message to the access network device according to the received PCC rule. Optionally, the SMF may also follow the local policy when sending the N2 session management message to the access network device.

[0434] Among them, the N2 session management message includes PDU Set QoS parameters and synchronization indication information #3. The PDU Set QoS parameters and synchronization indication information #3 can refer to step 306.

[0435] Optionally, the N2 session management message may also include associated identification information #3. The associated identification information #3 is used to indicate the identification method of the association relationship between PDU Sets in multi-modal traffic flows. For specific descriptions, reference can be made to the description at the associated identification information #1 in step 301. Exemplarily, when there is only one default identification method, the N2 session management message may not include the associated identification information #3.

[0436] Step 807, each network element or device executes the remaining processes of the PDU session establishment or modification process. The specific process can refer to the prior art, such as Section 4.3.2.1 of TS23.502, which will not be elaborated here.

[0437] After multiple UPFs receive the downlink data packet, each UPF can process the downlink data packet in the manner of steps 808 and 809. Steps 808 and 809 are as follows.

[0438] Step 808, when the downlink data packet of multi-modal traffic arrives at the UPF, the UPF adds the timestamp or PDU Set SN in the PTR header of the downlink data packet to the GTP-U header of the downlink data packet according to the N4 rule from the SMF.

[0439] In a possible implementation, when the N4 rule includes the associated marking information #D, the UPF can, according to the associated marking information #D, add the timestamp in the PTR header of the downlink data packet to the GTP-U header of the downlink data packet, or add the PDU Set SN in the PTR header of the downlink data packet to the GTP-U header of the downlink data packet.

[0440] In another possible implementation, when the N4 rule does not include the associated marking information #D, the UPF can, based on a default method or an internal implementation, add the timestamp in the PTR header of the downlink data packet to the GTP-U header of the downlink data packet, or add the PDU Set SN in the PTR header of the downlink data packet to the GTP-U header of the downlink data packet.

[0441] In addition, at the UPF, the downlink data packets can also be identified to determine and mark the downlink data packets belonging to the same PDU Set.

[0442] Step 809: The UPF sends the downlink data packet to the access network device. Correspondingly, the access network device receives the downlink data packet from the UPF.

[0443] Step 810: The access network device determines the multi-modal service flows that need to be synchronized according to the synchronization indication information #3 from the SMF.

[0444] Step 811: The access network device performs PDU Set association identification among the multi-modal service flows that need to be synchronized, determines the PDU Sets with an association relationship, and performs synchronized transmission on the PDU Sets with an association relationship.

[0445] The manner in which the access network device performs PDU Set association identification among the multi-modal service flows that need to be synchronized can refer to the manner in which the UPF performs PDU Set association identification among the multi-modal service flows that need to be synchronized. The difference is that the access network device relies on the timestamp or PDU set SN in the GTP-U header of the downlink data packet.

[0446] The manner in which the access network device performs synchronized transmission on the PDU Sets with an association relationship can refer to Step 312 and will not be elaborated further.

[0447] In addition, Figure 7 and Figure 8 the manner shown is also applicable to Scenario 1.

[0448] The embodiments of the present application also provide a solution for ensuring synchronized transmission of multiple service flows at the application layer. The solution will be described below.

[0449] Figure 9It is a schematic flowchart of a communication method 900 provided by an embodiment of the present application.

[0450] The method 900 may be executed by an access network device, a UPF, an AF, an AS, and / or an application service provider (ASP). Without special instructions, "access network device", "UPF", "AF", "AS", or "ASP" may refer to the access network device, UPF, AF, AS, or ASP itself, or may refer to a device capable of supporting the access network device, UPF, AF, AS, or ASP to implement its functions. For the convenience of description, the access network device, UPF, AF, AS, or ASP will be uniformly used hereinafter for description.

[0451] Exemplarily, the AF may be a real-time communication (RTC) AF.

[0452] It should be noted that Figure 9 the AF, AS, and ASP in may be independent network elements or devices, or may be functional units obtained by logical partitioning on a communication device, without limitation.

[0453] The method 900 includes at least some of the following content.

[0454] Step 901, the ASP determines and sends first configuration information to the AF. Correspondingly, the AF receives the first configuration information from the ASP.

[0455] Among them, the first configuration information is used to indicate synchronous transmission of a first traffic flow and a second traffic flow of a service or to indicate that the AF configures an application server to ensure synchronous transmission of the first traffic flow and the second traffic flow, that is, to configure the application server to perform corresponding marking processing on the associated PDU Set of the first traffic flow and the second traffic flow.

[0456] Step 902, the AF sends second configuration information to the AS according to the first configuration information. Correspondingly, the AS receives the second configuration information from the AF.

[0457] Among them, the second configuration information is used to indicate adding the same association information to the PDU Set associated between the first traffic flow and the second traffic flow.

[0458] Optionally, the second configuration information is further used to indicate a synchronization type. The synchronization type is single-user synchronization or multi-user synchronization. Single-user synchronization means that the first traffic flow and the second traffic flow are traffic flows of the same user. Multi-user synchronization means that the first traffic flow and the second traffic flow are traffic flows of different users.

[0459] Step 903, the AF sends the first indication information to the access network device. Correspondingly, the access network device receives the first indication information from the AF.

[0460] Among them, the first indication information is used to indicate that the first service flow and the second service flow are associated.

[0461] The implementation manner of step 903 can refer to steps 701, 702, 703, and 705, which will not be elaborated here.

[0462] Step 904, the AF sends the sixth indication information to the UPF. Correspondingly, the UPF receives the sixth indication information from the AF.

[0463] Among them, the sixth indication information is used to indicate that the UPF adds the association information carried in the PDU Set to the GTP-U header.

[0464] Step 904 is an optional step. The implementation manner of step 904 can refer to steps 701, 702, 703, and 704, which will not be elaborated here.

[0465] Step 905, the AS adds the same association information to the first PDU Set of the first service flow and the second PDU Set of the second service flow according to the second configuration information.

[0466] Among them, the first PDU Set and the second PDU Set are associated.

[0467] Specifically, the AS adds the first association information to the first PDU Set and the second association information to the second PDU Set, and the first association information and the second association information are the same.

[0468] Exemplarily, the first association information and the second association information are PDU SetSN or other synchronization marks.

[0469] Step 906, the AS sends the first PDU Set of the first service flow and the second PDU Set of the second service flow to the UPF. Correspondingly, the UPF receives the first PDU Set of the first service flow and the second PDU Set of the second service flow from the AS.

[0470] Among them, the first PDU Set and the second PDU Set carry the same association information.

[0471] Step 907, the UPF adds the first association information in the first PDU Set to the GTP-U header of the first PDU Set, and adds the second association information in the second PDU Set to the GTP-U header of the second PDU Set.

[0472] When the UPF receives the sixth indication information, according to the sixth indication information, the UPF adds the first association information in the first PDU Set to the GTP-U header of the first PDU Set, and adds the second association information in the second PDU Set to the GTP-U header of the second PDU Set. It should be noted that at this time, the UPF needs to strictly copy the PDU Set SN in the RTP extension header of the first PDU Set to the GTP-U layer of the corresponding data packet of the first PDU Set.

[0473] Step 908, the UPF sends the first PDU Set of the first service flow and the second PDU Set of the second service flow to the access network device. Correspondingly, the access network device receives the first PDU Set of the first service flow and the second PDU Set of the second service flow from the UPF.

[0474] Step 909, the access network device synchronously transmits the first PDU Set and the second PDU Set according to the first indication information, the first association information carried by the first PDU Set, and the second association information carried by the second PDU Set.

[0475] Step 909 can refer to Step 510 and will not be elaborated here.

[0476] The following combines Figure 10 , and details the solution for synchronously transmitting application layer guaranteed multi-modal service flows.

[0477] Figure 10 is a schematic flowchart of the communication method 1000 provided by the embodiments of the present application.

[0478] Figure 10 The configuration information #1 and configuration information #2 in

[0479] can correspond to the first configuration information and the second configuration information above.

[0480] Step 1001, the ASP sends the configuration information #1 to the AF. Correspondingly, the AF receives the configuration information #1 from the ASP.

[0481] Among them, the configuration information #1 is used to configure or create service #1.

[0482] The configuration information #1 in the embodiment of the present application may include indication information #1, which is used to indicate the synchronous transmission guarantee for multiple service flows serving service #1. Optionally, the indication information #1 may also be used to indicate that the multiple service flows belong to the same terminal device or to indicate that the multiple service flows belong to multiple terminal devices. In other words, the indication information #1 is used to indicate the synchronous transmission guarantee for multiple service flows belonging to the same terminal device of service #1 or to indicate the synchronous transmission guarantee for multiple service flows belonging to multiple terminal devices of service #1. Optionally, the indication information #1 is also used to indicate that when identifying and marking the PDU Set in the service flow, it is marked according to the PDU Set SN carried in the downlink data packet.

[0483] In a possible implementation, the ASP carries the above configuration information #1 in the message for creating a provisioning session (create a provisioning session).

[0484] Step 1002, the AF sends the configuration information #2 to the AS according to the configuration information #1. Correspondingly, the AS receives the configuration information #2 from the AF.

[0485] Among them, the configuration information #2 includes indication information #2, and the indication information #2 is used to indicate that when adding the PDU Set SN to the PDU Set of multiple service flows serving service #1, the same PDU Set SN or synchronous marking is added to the PDU Sets with an associated relationship between the multiple service flows.

[0486] Optionally, the configuration information #2 includes a synchronization type, and the synchronization type is single-user synchronization or multi-user synchronization. Among them, single-user synchronization means that multiple service flows of the same user need to be synchronously transmitted and guaranteed. Multi-user synchronization means that multiple service flows between multiple users need to be synchronously transmitted and guaranteed.

[0487] Step 1003, the AF sends a response message to the ASP. Correspondingly, the ASP receives the response message from the AF.

[0488] Among them, the response message is used to confirm the creation of service #1.

[0489] In a possible implementation, the response message is a message for confirming the creation of a provisioning session (confirm creation of provisioning session).

[0490] The configuration process of service #1 of the ASP is completed through steps 1001 to 1003.

[0491] Step 1004, the terminal device establishes a connection with the AS.

[0492] Specifically, an application (App) in the terminal device starts, and the client establishes a connection with the AS, such as a WebRTC connection. Specifically, it can be that the RTC media session handler (MSH) in the terminal device establishes a connection with the AS.

[0493] Step 1005: The AS adds the same PDU Set SN or synchronization mark to the PDU Set with an association relationship among multiple service flows serving Service #1 according to the configuration information #2 from the AF.

[0494] Specifically, the AS adds the same PDU Set SN or synchronization mark to the PDU Set with an association relationship among multiple service flows serving Service #1 according to the indication information #2 in the configuration information #2. Optionally, when the configuration information #2 includes a synchronization type, the AS adds the same PDU Set SN or synchronization mark to the PDU Set with an association relationship among multiple service flows serving Service #1 according to the indication information #2 and the synchronization type.

[0495] Adding the same PDU Set SN or synchronization mark to the PDU Set with an association relationship among multiple service flows serving Service #1 based on the configuration information of the AF is just one implementation manner of adding the same PDU Set SN or synchronization mark to the PDU Set with an association relationship among multiple service flows serving Service #1. In other implementation manners, the AF can also add the same PDU Set SN or synchronization mark to the PDU Set with an association relationship among multiple service flows serving Service #1 based on local configuration or based on negotiation with the terminal device.

[0496] Step 1006: The AF provides synchronization assistance information to the core network.

[0497] The implementation of Step 1006 can refer to Steps 301 to 305. The difference is that the synchronization assistance information may not have the association identification information #1, and the PCC rules generated by the PCF may also not have the association identification information #2. The SMF does not need to provide the synchronization indication information #2, the association identification information #3, and the association mark information #1 to the UPF. Additionally, the synchronization assistance information further includes indication information for indicating that the PDU Set in the service flow is marked according to the PDU Set SN carried in the downlink data packet.

[0498] Optionally, AF may provide indication information #3 to the UPF via the PCF and the SMF, and the indication information #3 is used to indicate that the UPF adds the PDU Set SN or the synchronization mark in the RTP header of the downlink data packet to the GTP-U header of the downlink data packet.

[0499] Step 1007: The core network provides the synchronization indication information #3 and an optional synchronization transmission delay to the access network device. Step 1007 may refer to Step 306.

[0500] Step 1008: When the downlink data packet of the multi-modal service arrives at the UPF, the UPF adds the PDU Set SN or the synchronization mark in the PTR header of the downlink data packet to the GTP-U header of the downlink data packet.

[0501] Step 1009: The UPF sends the downlink data packet to the access network device. Correspondingly, the access network device receives the downlink data packet from the UPF.

[0502] Step 1010: The access network device determines the multi-modal service flows that need to be synchronized according to the synchronization indication information #3 from the SMF.

[0503] Step 1011: The access network device performs synchronous transmission on the PDU Sets carrying the same PDU Set SN or the same synchronization mark in the multi-modal service flows that need to be synchronized. Step 1010 may refer to Step 312.

[0504] As described above in conjunction with Figures 2 to 10 , the method embodiments provided in this application have been described in detail. Next, the device embodiments of this application will be described in conjunction with Figures 11 to 13 .

[0505] It can be understood that, in order to implement the functions in the above embodiments, Figures 11 to 13 the devices in

[0506] Figure 11 and Figure 12 are schematic structural diagrams of possible devices provided in the embodiments of this application. These devices can be used to implement the functions of the access network device, the user plane function network element, the application function network element, the application service provider, or the application server in the above method embodiments, and thus can also achieve the beneficial effects possessed by the above method embodiments.

[0507] As Figure 11 shown, the device 10 includes a transceiver unit 11 and a processing unit 12.

[0508] When the apparatus 10 is used to implement the functions of the access network device, user plane function network element, application function network element, application service provider, or application server in the above method embodiments, the transceiver unit 11 is used to execute the transceiver steps of the access network device, user plane function network element, application function network element, application service provider, or application server, and the processing unit 12 is used to execute the processing steps of the access network device, user plane function network element, application function network element, application service provider, or application server.

[0509] For a more detailed description of the above transceiver unit 11 and processing unit 12, reference may be made to the relevant descriptions in the above method embodiments, which will not be elaborated here.

[0510] As Figure 12 shown, the apparatus 20 includes a processing circuit 21. The processing circuit 21 is coupled to a memory 23, and the memory 23 is used to store instructions. When the apparatus 20 is used to implement the method described above, the processing circuit 21 is used to execute the instructions in the memory 23 to implement the function of the above processing unit 12.

[0511] Optionally, the apparatus 20 further includes a memory 23.

[0512] Optionally, the apparatus 20 further includes a transceiver circuit 22. The transceiver circuit may be referred to as a communication interface. The processing circuit 21 and the transceiver circuit 22 are coupled to each other. It can be understood that the transceiver circuit 22 may be a transceiver or an input / output interface. When the apparatus 20 is used to implement the method described above, the processing circuit 21 is used to execute instructions to implement the function of the above processing unit 12, and the transceiver circuit 22 is used to implement the function of the above transceiver unit 11.

[0513] Optionally, the apparatus 20 may be an access network device, user plane function network element, application function network element, application service provider, or application server. Correspondingly, the transceiver circuit may be a transceiver.

[0514] Optionally, the apparatus 20 may be a chip applied to an access network device, user plane function network element, application function network element, application service provider, or application server. Correspondingly, the transceiver circuit may be an input / output interface.

[0515] Exemplarily, when the device 20 is a chip applied to an access network device, a user plane function network element, an application function network element, an application service provider, or an application server, the chip implements the functions of the access network device, the user plane function network element, the application function network element, the application service provider, or the application server in the above method embodiments. The chip receives information from other modules (such as a radio frequency module or an antenna) in the access network device, the user plane function network element, the application function network element, the application service provider, or the application server, and the information is sent by other devices to the access network device, the user plane function network element, the application function network element, the application service provider, or the application server; or, the chip sends information to other modules (such as a radio frequency module or an antenna) in the access network device, the user plane function network element, the application function network element, the application service provider, or the application server, and the information is sent by the access network device, the user plane function network element, the application function network element, the application service provider, or the application server to other devices.

[0516] Figure 13 It is a schematic diagram of a chip system 30 provided by an embodiment of the present application. The chip system 30 (or can also be referred to as a processing system) includes a logic circuit 31 and an input / output interface 32.

[0517] Among them, the logic circuit 31 can be a processing circuit in the chip system 30. The logic circuit 31 can be coupled to a storage unit and call instructions in the storage unit, so that the chip system 30 can implement the methods and functions of the embodiments of the present application. The input / output interface 32 can be an input / output circuit in the chip system 30, output the information processed by the chip system 30, or input the data or signaling information to be processed into the chip system 30 for processing.

[0518] As a solution, the chip system 30 is used to implement the operations performed by the access network device, the user plane function network element, the application function network element, the application service provider, or the application server in the above method embodiments.

[0519] For example, the logic circuit 31 is used to implement the operations related to processing performed by the access network device, the user plane function network element, the application function network element, the application service provider, or the application server in the above method embodiments; the input / output interface 32 is used to implement the operations related to sending and / or receiving performed by the access network device, the user plane function network element, the application function network element, the application service provider, or the application server in the above method embodiments.

[0520] The present application further provides a communication device, including a processing circuit, which is coupled to a memory. The memory is used to store computer programs or instructions and / or data. The processing circuit is used to execute the computer programs or instructions stored in the memory, or read the data stored in the memory, so as to execute the methods in the above method embodiments. Optionally, the processing circuit is one or more. Optionally, the communication device includes a memory. Optionally, the memory is one or more. Optionally, the memory is integrated with the processing circuit or is separately provided.

[0521] The present application further provides a chip, including a processing circuit, and the processing circuit is coupled to a memory. The memory is used to store computer programs or instructions. The processing circuit is used to execute the computer programs or instructions stored in the memory to implement the methods executed by the access network device, user plane function network element, application function network element, application service provider or application server in the above method embodiments. The memory may be located inside the chip or may be independent of the chip and located outside the chip, which is not limited herein.

[0522] The present application further provides a computer-readable storage medium, on which computer instructions are stored for implementing the methods executed by the access network device, user plane function network element, application function network element, application service provider or application server in the above method embodiments.

[0523] The present application further provides a computer program product, including instructions, which when executed by a computer, implement the methods executed by the access network device, user plane function network element, application function network element, application service provider or application server in the above method embodiments.

[0524] The present application further provides a communication system, which includes at least one of the access network device, user plane function network element, application function network element, application service provider or application server in the above embodiments.

[0525] For the explanations and beneficial effects of the relevant content in any of the above provided devices, reference may be made to the corresponding method embodiments provided above, and details are not described herein again.

[0526] It can be understood that the processing circuit in the embodiments of the present application may be a processor or a circuit in the processor for performing processing operations. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0527] The method steps in the embodiments of the present application may be implemented in a hardware manner or by a processor executing software instructions. The software instructions may be composed of corresponding software modules, and the software modules may be stored in a random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, removable hard disks, compact disc read-only memories (CD-ROMs), or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium may also be a component of the processor. The processor and the storage medium may be located in an ASIC. Additionally, the ASIC may be located in an access network device, a user plane function network element, an application function network element, an application service provider, or an application server. Of course, the processor and the storage medium may also exist as discrete components in an access network device, a user plane function network element, an application function network element, an application service provider, or an application server.

[0528] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are executed in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device, or other programmable devices. The computer program or instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer program or instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center in a wired or wireless manner. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or a data center integrating one or more available media. The available medium can be a magnetic medium, such as a floppy disk, a hard disk, or a magnetic tape; it can also be an optical medium, such as a digital video disc; or it can be a semiconductor medium, such as a solid-state drive.

[0529] In various embodiments of the present application, if there is no special explanation and logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0530] Unless otherwise specified, all technical and scientific terms used in the embodiments of the present application have the same meaning as commonly understood by those skilled in the technical field of the present application. The terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the scope of the present application. It should be understood that the above is for illustrative purposes only, and the above examples are only to help those skilled in the art understand the embodiments of the present application, rather than to limit the embodiments of the application to the specific numerical values or specific scenarios shown. Obviously, those skilled in the art can make various equivalent modifications or changes based on the examples given above, and such modifications and changes also fall within the scope of the embodiments of the present application.

Claims

1. A communication method, characterized in that, the method includes: The access network device obtains first indication information, where the first indication information is used to indicate that a first traffic flow and a second traffic flow are associated; The access network device receives a first protocol data unit set (PDU Set) of the first traffic flow and a second PDU Set of the second traffic flow, where the first PDU Set and / or the second PDU Set carry association information, and the association information is used for the access network device to determine that the first PDU Set and the second PDU Set are associated; The access network device synchronously transmits the first PDU Set and the second PDU Set according to the first indication information and the association information.

2. The method according to claim 1, characterized in that, the method further includes: the access network device obtains second indication information, where the second indication information is used to indicate the synchronization requirement between the first traffic flow and the second traffic flow; The access network device synchronously transmits the first PDU Set and the second PDU Set according to the first indication information and the association information, including: the access network device synchronously transmits the first PDU Set and the second PDU Set according to the first indication information, the association information, and the second indication information.

3. The method according to claim 2, characterized in that, the synchronization requirement includes the maximum value of the transmission delay difference between the PDU Sets associated between the first traffic flow and the second traffic flow.

4. The method according to any one of claims 1 to 3, characterized in that, The access network device synchronously transmits the first PDU Set and the second PDU Set according to the first indication information and the association information, including: The access network device determines that the first traffic flow and the second traffic flow are associated according to the first indication information; The access network device determines that the first PDU Set and the second PDU Set are associated according to the association information; The access network device synchronously transmits the associated first PDU Set and second PDU Set.

5. The method according to claim 4, characterized in that, The first PDU Set and / or the second PDU Set carry association information, including: the first PDU Set carries first association information, and the second PDU Set carries second association information; The access network device determines that the first PDU Set and the second PDU Set are associated according to the association information, including: when the first association information and the second association information are the same, the difference between the first association information and the second association information is within a threshold range, or the difference between the first association information and the second association information is less than or equal to the threshold, the access network device determines that the first PDU Set and the second PDU Set are associated.

6. The method according to claim 5, wherein, the threshold value comes from the core network.

7. The method according to claim 4, wherein, the association information is used to indicate an offset value between the identification information of the associated PDU Set between the first traffic flow and the second traffic flow; the first PDU Set further carries first identification information, and the second PDU Set further carries second identification information; The access network device determines that the first PDU Set and the second PDU Set are associated according to the association information, including: when the difference between the first identification information and the second identification information is equal to the offset value, the access network device determines that the first PDU Set and the second PDU Set are associated.

8. The method according to claim 4, wherein, the method further includes: the access network device receives, through control plane signaling, an offset value between the association information of the associated PDU Set between the first traffic flow and the second traffic flow from a user plane function network element or an application function network element; The first PDU Set and / or the second PDU Set carry association information, including: the first PDU Set carries first association information, and the second PDU Set carries second association information; The access network device determines that the first PDU Set and the second PDU Set are associated according to the association information, including: when the difference between the first association information and the second association information is equal to the offset value, the access network device determines that the first PDU Set and the second PDU Set are associated.

9. The method according to any one of claims 1 to 8, wherein, the association information is included in the General Packet Radio Service Tunneling Protocol - User Plane (GTP-U) header of the PDU Set.

10. The method according to any one of claims 1 to 9, wherein, the first indication information includes the identifier of the first traffic flow and the identifier of the second traffic flow; or, the first indication information includes the identifier of the first traffic flow, the identifier of the first session to which the first traffic flow belongs, the identifier of the first terminal device to which the first session belongs, the identifier of the second traffic flow, the identifier of the second session to which the second traffic flow belongs, and / or the identifier of the second terminal device to which the second session belongs.

11. A communication method, wherein, the method includes: a user plane function network element obtains first indication information, and the first indication information is used to indicate that a first traffic flow is associated with a second traffic flow; The user plane function network element receives a first set of protocol data units (PDU Set) of the first service flow and a second PDU Set of the second service flow. The first PDU Set carries third association information, and the second PDU Set carries fourth association information. The third association information and the fourth association information are used by the user function network element to determine that the first PDU Set is associated with the second PDU Set; The user plane function network element adds association information to the first PDU Set and / or the second PDU Set according to the first indication information, the third association information, and the fourth association information. The association information is used by the access network device to determine that the first PDU Set is associated with the second PDU Set; The user plane function network element sends the first PDU Set and the second PDU Set to the access network device.

12. The method according to claim 11, wherein, The user plane function network element adding association information to the first PDU Set and / or the second PDU Set according to the first indication information, the third association information, and the fourth association information includes: The user plane function network element determines that the first service flow and the second service flow are associated according to the first indication information; The user plane function network element determines that the first PDU Set and the second PDU Set are associated according to the third association information and the fourth association information; The user plane function network element adds the association information to the first PDU Set and / or the second PDU Set.

13. The method according to claim 12, wherein, The user plane function network element determining that the first PDU Set and the second PDU Set are associated according to the third association information and the fourth association information includes: When the third association information and the fourth association information are the same, the difference between the third association information and the fourth association information is less than or equal to a threshold, the difference between the third association information and the fourth association information is within the threshold range, or the difference between the third association information and the fourth association information is equal to an offset value, the user plane function network element determines that the first PDU Set and the second PDU Set are associated. The offset value is the offset value between the association information of the PDU Sets associated between the first service flow and the second service flow.

14. The method according to claim 13, wherein, The threshold and / or the offset value are from the session management function network element.

15. The method according to any one of claims 11 to 14, wherein, The user plane function network element adding association information to the first PDU Set and / or the second PDU Set according to the first indication information, the third association information, and the fourth association information includes: The user plane function network element adds first association information to the first PDU Set and second association information to the second PDU Set according to the first indication information, the third association information, and the fourth association information, and the first association information and the second association information are the same.

16. The method according to any one of claims 11 to 14, wherein, the association information is used to indicate an offset value between identification information of associated PDU Sets between the first traffic flow and the second traffic flow; the method further includes: the user plane function network element adds first identification information to the first PDU Set and second identification information to the second PDU Set, the first identification information is the same as the third association information, and the second identification information is the same as the fourth association information.

17. The method according to claim 16, wherein, the method further includes: the user plane function network element determines the offset value according to the third association information and the fourth association information.

18. The method according to any one of claims 11 to 17, wherein, the method further includes: the user plane function network element obtains third indication information, and the third indication information is used to indicate that the user plane function network element identifies associated PDU Sets.

19. The method according to claim 18, wherein, the third indication information is further used to indicate the manner in which the user plane function network element identifies associated PDU Sets, and the manner is any one of the following manners: identifying based on a time stamp, or identifying based on a PDU Set sequence number SN.

20. The method according to any one of claims 11 to 19, wherein, the method further includes: the user plane function network element obtains fourth indication information, and the fourth indication information is used to indicate that the user plane function network element marks associated PDU Sets.

21. The method according to any one of claims 11 to 20, wherein, the first indication information includes an identifier of the first traffic flow and an identifier of the second traffic flow; or, the first indication information includes an identifier of the first traffic flow, an identifier of a first session to which the first traffic flow belongs, an identifier of a first terminal device to which the first session belongs, an identifier of the second traffic flow, an identifier of a second session to which the second traffic flow belongs, and / or an identifier of a second terminal device to which the second session belongs.

22. A communication method, wherein, the method includes: a user plane function network element obtains fifth indication information, and the fifth indication information is used to indicate association information added by the user plane function network element to a first traffic flow, and the association information is used for an access network device to determine associated protocol data unit sets PDU Sets between the first traffic flow and a second traffic flow; the user plane function network element receives a first PDU Set of the first traffic flow; The user plane function network element adds association information to the first PDU Set according to the fifth indication information; The user plane function network element sends the first PDU Set to the access network device.

23. The method according to claim 22, wherein, the fifth indication information includes a third timestamp corresponding to the first traffic flow and a third PDU Set sequence number SN corresponding to the third timestamp, and the association information added by the user plane function network element to the first PDU Set is the first PDU Set SN; Adding association information to the first PDU Set according to the fifth indication information includes: adding the first PDU Set SN to the first PDU Set according to the third timestamp, the third PDU Set SN, and the first timestamp carried by the first PDU Set.

24. The method according to claim 23, wherein, the method further includes: obtaining period information, where the period information is used to indicate the time interval between two adjacent PDU Sets of the first traffic flow; Adding the second PDU Set SN to the first PDU Set according to the third timestamp, the third PDU Set SN, and the first timestamp carried by the first PDU Set includes: adding the first PDU Set SN to the first PDU Set according to the third timestamp, the third PDU Set SN, the first timestamp, and the period information.

25. The method according to claim 22, wherein, the fifth indication information includes an offset value of the PDU Set sequence number SN corresponding to the first traffic flow, and the association information added by the user plane function network element to the first PDU Set is the first PDU Set SN; Adding association information to the first PDU Set according to the fifth indication information includes: adding the first PDU Set SN to the PDU Set according to the offset value and the fourth PDU Set SN carried by the first PDU Set, and the first PDU Set SN is offset from the fourth PDU Set SN by the offset value.

26. A communication method, wherein, the method includes: A user plane function network element and an access network device obtain first indication information, where the first indication information is used to indicate that a first traffic flow is associated with a second traffic flow; The user plane function network element receives a first protocol data unit set PDU Set of the first traffic flow and a second PDU Set of the second traffic flow, the first PDU Set carries third association information, the second PDU Set carries fourth association information, and the third association information and the fourth association information are used for the user function network element to determine that the first PDU Set is associated with the second PDU Set; The user plane function network element adds association information to the first PDU Set and / or the second PDU Set according to the first indication information, the third association information, and the fourth association information, where the association information is used for the access network device to determine that the first PDU Set is associated with the second PDU Set; The user plane function network element sends the first PDU Set and the second PDU Set to the access network device; The access network device synchronously transmits the first PDU Set and the second PDU Set according to the first indication information and the association information carried in the first PDU Set and / or the second PDU Set.

27. A communication method, characterized in that, the method includes: The access network device obtains first indication information, where the first indication information is used to indicate that a first service flow and a second service flow are associated; The user plane function network element obtains fifth indication information, where the fifth indication information is used to indicate the association information added by the user plane function network element to the first service flow and / or the association information added to the second service flow, and the association information is used to determine the protocol data unit set (PDU Set) associated between the first service flow and the second service flow; The user plane function network element receives a first PDU Set of the first service flow and a second PDU Set of the second service flow; According to the fifth indication information, add association information to the first PDU Set and / or the second PDU Set; The user plane function network element sends the first PDU Set and the second PDU Set to the access network device; The access network device synchronously transmits the first PDU Set and the second PDU Set according to the first indication information and the association information carried in the first PDU Set and / or the second PDU Set.

28. A communication device, characterized in that, it includes a module or unit for executing the method according to any one of claims 1 to 27.

29. A communication device, characterized in that, it includes a processor and an interface circuit. The interface circuit is used to receive signals from other communication devices outside the communication device and transmit them to the processor or send signals from the processor to other communication devices outside the communication device. The processor uses logic circuits or executes code instructions to implement the method according to any one of claims 1 to 27.

30. A chip, characterized in that, it includes a processor, the processor is coupled to a memory, the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory to implement the method according to any one of claims 1 to 27.

31. A computer-readable storage medium, characterized in that, the storage medium stores a computer program or instruction, and when the computer program or instruction is executed by a communication device, it implements the method according to any one of claims 1 to 27.

32. A computer program product, characterized in that, it includes a computer program which, when run, implements the method according to any one of claims 1 to 27.

33. A communication system, characterized in that, it includes a communication device for executing the method according to any one of claims 1 to 10 and a communication device for executing the method according to any one of claims 11 to 21, or includes a communication device for executing the method according to any one of claims 1 to 10 and a communication device for executing the method according to any one of claims 22 to 25.

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