Handover method, apparatus and system

Abstract

The embodiment of the application provides a switching method, device and system, which can meet the determinacy of transmission between a target access network device and a user plane network element in a terminal device mobility scenario. The method comprises the following steps: a first device determines interface configuration information of a second device in the case that a first service flow is switched from a source access network device serving a terminal device to a target access network device serving the terminal device; the interface configuration information is used for the second device to send the first service flow at a service flow sending time after receiving the first service flow; if the first service flow is an uplink service flow, the second device is the target access network device or a converter corresponding to the target access network device; if the first service flow is a downlink service flow, the second device is a first user plane network element; the first device sends the interface configuration information to the second device, and after learning that an interface configuration associated with the interface configuration information is completed from the second device, informs the target access network device or the source access network device to execute a switching execution process.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to switching methods, apparatus and systems. Background Technology

[0002] In the traditional Ethernet packet forwarding process, when a large number of packets arrive at the forwarding port in an instant, it will cause large forwarding delays or packet loss. Therefore, traditional Ethernet cannot provide highly reliable services with guaranteed transmission latency, and cannot meet the needs of fields such as automotive control and industrial internet.

[0003] The Institute of Electrical and Electronics Engineers (IEEE) defined the Time Sensitive Networking (TSN) standard to address the need for reliable latency transmission. This standard can provide reliable latency transmission services based on Layer 2 switching, ensuring the reliability of data transmission for latency-sensitive services and predictable end-to-end transmission latency.

[0004] like Figure 1 As shown, a TSN system may include a centralized network configuration (CNC) network element, a centralized user configuration (CUC) network element, TSN end stations, and various switching nodes (TSN bridges). A TSN end station includes a talker and a listener.

[0005] In this system, the 5G System (5GS) as a whole can function as a switching node. The CNC network element can configure each switching node based on information reported by the 5GS and other switching nodes to ensure deterministic end-to-end latency (from TSN Talker to TSN Listener). For example... Figure 2As shown, a 5GS switching node includes at least the following devices: a user plane function (UPF) network element, a TSN translator (TT) on the UPF network element side (hereinafter referred to as network-side TT, NW-TT), a next-generation NodeB (gNB), and a TT on the terminal device side (hereinafter referred to as device-side TT, DS-TT). Taking a downstream data packet as an example, the data packet is transmitted from the TSN system to the NW-TT, and the NW-TT sends the data packet to the DS-TT through the UPF network element, gNB, and terminal device.

[0006] However, in terminal device mobility scenarios, if a terminal device switches from its current radio access network (RAN) device (referred to as the source RAN device) to another RAN device (referred to as the target RAN device), how to ensure deterministic transmission between the target RAN device and the UPF network element is a pressing issue that needs to be addressed. Summary of the Invention

[0007] This application provides a handover method, apparatus, and system that can satisfy the deterministic transmission between the target access network device and the user plane network element in terminal device mobility scenarios.

[0008] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0009] Firstly, a handover method is provided. This method can be executed by a first device or by a component within the first device, such as a processor, chip, or chip system. This application uses the execution of the handover method by a first device as an example for illustration. The method includes: when the first device determines that a first service flow is being switched from a source access network device serving a terminal device to a target access network device serving the terminal device, interface configuration information is provided for a second device. The interface configuration information is used by the second device to send the first service flow at the service flow transmission time after receiving the first service flow. Wherein, if the first service flow is an uplink service flow, the second device is the target access network device or a converter corresponding to the target access network device; if the first service flow is a downlink service flow, the second device is a first user plane network element; the first device sends the interface configuration information to the second device; after the first device learns from the second device that the interface configuration associated with the interface configuration information is complete, it notifies the target access network device or the source access network device to execute (or continue executing) the handover execution process. In other words, the handover method provided in this application embodiment can complete the interface configuration for the second device before the handover process ends, so that after the second device receives the first service flow, it can send the first service flow at the service flow sending time. Therefore, this solution can meet the deterministic transmission between the target access network device and the user plane network element in the terminal device mobility scenario.

[0010] In conjunction with the first aspect mentioned above, in one possible implementation, the interface configuration information includes first interface configuration information. This first interface configuration information is used by the second device to send the first service flow through a first path at the first service flow transmission time. The first path is the path from the second device to the third device. If the first service flow is an uplink service flow, the third device is a first user plane network element; if the first service flow is a downlink service flow, the third device is a target access network device or a converter corresponding to the target access network device. Based on this scheme, deterministic transmission between the target access network device and the user plane network element can be satisfied in terminal device mobility scenarios when the first service flow is transmitted on the first path.

[0011] In conjunction with the first aspect mentioned above, in one possible implementation, the first interface configuration information includes information about the first service flow sending time.

[0012] In conjunction with the first aspect above, in one possible implementation, the information of the first service flow transmission time includes at least one of the following: the first service flow transmission time, the offset of the first service flow transmission time relative to the reference time, or a first gating scheduling parameter. The first gating scheduling parameter is used by the second device to transmit the first service flow through the first path at the first service flow transmission time.

[0013] In conjunction with the first aspect described above, in one possible implementation, the switching method provided in this application further includes: a first device receiving first indication information, the first indication information indicating that data transmission of a first service flow on a second path is complete, the second path being the path from a first user plane network element to a source access network device; the first device sending second indication information to a centralized network configuration network element, the second indication information indicating the deletion of information about the service flow group corresponding to the first service flow during transmission on the second path. Based on this scheme, after the data transmission of the first service flow on the second path is completed, the information about the service flow group corresponding to the first service flow during transmission on the second path stored in the centralized network configuration network element can be deleted promptly, saving storage space in the centralized network configuration network element.

[0014] In conjunction with the first aspect mentioned above, in one possible implementation, the first service flow is a downlink service flow; the interface configuration information includes second interface configuration information, which is used by the second device to send the first service flow to the target access network device through the forwarding path during the second service flow transmission time. Based on this scheme, deterministic transmission between the target access network device and the user plane network element can be satisfied in terminal device mobility scenarios when the first service flow is transmitted on the forwarding path.

[0015] In conjunction with the first aspect mentioned above, in one possible implementation, the second interface configuration information includes information about the second service flow sending time.

[0016] In conjunction with the first aspect above, in one possible implementation, the information on the second service flow transmission time includes at least one of the following: the second service flow transmission time, the offset of the second service flow transmission time relative to the reference time, or a second gating scheduling parameter. The second gating scheduling parameter is used by the second device to transmit the first service flow through the forwarding path during the second service flow transmission time.

[0017] In conjunction with the first aspect described above, in one possible implementation, the switching method provided in this application further includes: a first device receiving third indication information, the third indication information indicating that the data transmission of the first service flow on the forwarding path is complete; the first device sending fourth indication information to the centralized network configuration element, the fourth indication information indicating the deletion of information about the service flow group corresponding to the first service flow during transmission on the forwarding path; and / or, the first device sending fifth indication information to the first user plane element, the fifth indication information indicating the deletion of second interface configuration information. Based on this scheme, after the data transmission of the first service flow on the forwarding path is complete, the information about the service flow group corresponding to the first service flow during transmission on the forwarding path stored in the centralized network configuration element and the second interface configuration information stored in the first user plane element can be deleted in a timely manner, thereby saving storage space in the centralized network configuration element and the first user plane element.

[0018] In conjunction with the first aspect above, in one possible implementation, the forwarding path consists of a path from the first user plane network element to the source access network device and a path from the source access network device to the target access network device; or, the forwarding path consists of a path from the first user plane network element to the second user plane network element, a path from the second user plane network element to the source access network device, a path from the source access network device to the second user plane network element, and a path from the second user plane network element to the target access network device.

[0019] Secondly, a handover method is provided. This method can be executed by a second device or by a component within the second device, such as a processor, chip, or chip system. This application uses the execution of the handover method by a second device as an example for illustration. The method includes: the second device receiving interface configuration information for itself when a first service flow switches from a source access network device serving a terminal device to a target access network device serving the terminal device; wherein, if the first service flow is an uplink service flow, the second device is the target access network device or a converter corresponding to the target access network device; if the first service flow is a downlink service flow, the second device is a first user plane network element; the second device performs interface configuration according to the interface configuration information, the interface configuration being used by the second device to send the first service flow at the service flow transmission time after receiving the first service flow; after performing interface configuration, the second device notifies the first device that the interface configuration is complete. In other words, the handover method provided in this application embodiment can enable the second device to send the first service flow at the service flow transmission time after receiving the first service flow through interface configuration. Therefore, this solution can meet the deterministic transmission between the target access network device and the user plane network element in terminal device mobility scenarios.

[0020] In conjunction with the second aspect described above, in one possible implementation, the second device is a target access network device. The handover method provided in this application further includes: after the second device notifies the first device that the interface configuration is complete, it executes a handover execution process according to the notification from the first device. Based on this scheme, the interface configuration for the second device can be completed before the handover process ends. Thus, after the handover process ends, once the second device receives the first service flow, it can promptly send the first service flow according to the interface configuration at the service flow sending time, thereby satisfying the deterministic transmission between the target access network device and the user plane network element.

[0021] In conjunction with the second aspect above, in one possible implementation, the interface configuration information includes first interface configuration information. This first interface configuration information is used by the second device to send the first service flow through a first path at the first service flow transmission time. The first path is the path from the second device to the third device. If the first service flow is an uplink service flow, the third device is a first user plane network element; if the first service flow is a downlink service flow, the third device is a target access network device or a converter corresponding to the target access network device. Based on this scheme, deterministic transmission between the target access network device and the user plane network element can be satisfied in terminal device mobility scenarios when the first service flow is transmitted on the first path.

[0022] In conjunction with the second aspect above, in one possible implementation, the first interface configuration information includes information about the first service flow sending time.

[0023] In conjunction with the second aspect above, in one possible implementation, the information of the first service flow transmission time includes at least one of the following: the first service flow transmission time, the offset of the first service flow transmission time relative to the reference time, or a first gating scheduling parameter. The first gating scheduling parameter is used by the second device to transmit the first service flow through the first path at the first service flow transmission time.

[0024] In conjunction with the second aspect mentioned above, in one possible implementation, the first service flow is a downlink service flow; the second device configures the interface according to the interface configuration information, including: the second device updates the locally stored interface configuration information, wherein the updated interface configuration information includes first interface configuration information, which replaces the initial interface configuration information. The initial interface configuration information is used by the second device to send the first service flow through a second path at the initial service flow transmission time. The second path is the path from the first user plane network element to the source access network device. In other words, in this implementation, the first interface configuration information and the initial interface configuration information cannot coexist. This scheme can save the storage resources of the second device while ensuring the deterministic transmission of the first service flow on the first path.

[0025] In conjunction with the second aspect mentioned above, in one possible implementation, the first service flow is a downlink service flow; the second device configures the interface according to the interface configuration information, including: the second device updates the locally stored interface configuration information, wherein the updated interface configuration information includes first interface configuration information and initial interface configuration information. The initial interface configuration information is used by the second device to send the first service flow through the second path at the initial service flow sending time, and the second path is the path from the first user plane network element to the source access network device. In other words, in this implementation, the first interface configuration information and the initial interface configuration information can coexist. This solution can, in terminal device mobility scenarios, satisfy the deterministic transmission of the first service flow on the first path while still satisfying the deterministic transmission of the first service flow on the second path.

[0026] In conjunction with the second aspect described above, in one possible implementation, the updated interface configuration information further includes a first identifier, which indicates that the first interface configuration information corresponds to the first path. Based on this scheme, it is easier to distinguish between multiple sets of interface configuration information stored on the second device.

[0027] In conjunction with the second aspect described above, in one possible implementation, the switching method provided in this application further includes: after the second device obtains the tunnel information of the target access network device, the second device deletes the initial interface configuration information; or, after the second device sends a data packet with an end marker corresponding to the first service flow to the source access network device, the second device deletes the initial interface configuration information. Based on this scheme, the second device can promptly delete the initial interface configuration information when it is not needed, thereby saving the storage resources of the second device.

[0028] In conjunction with the second aspect described above, in one possible implementation, the switching method provided in this application further includes: after the second device sends a data packet with an end marker corresponding to the first service flow to the source access network device, the second device sends the first service flow through the first path according to the first interface configuration information. This solution provides a solution for determining when to use the first interface configuration information when multiple sets of interface configuration information are stored simultaneously on the second device. It can be understood that in this application embodiment, the second device sending the first service flow through the first path according to the first interface configuration information can also be understood as the second device updating the interface configuration information mapped to the first service flow to the first interface configuration information. This will be uniformly explained here and will not be repeated below.

[0029] In conjunction with the second aspect above, in one possible implementation, the initial interface configuration information includes information about the initial business flow sending time.

[0030] In conjunction with the second aspect above, in one possible implementation, the information on the initial service flow transmission time includes at least one of the following: the initial service flow transmission time, the offset of the initial service flow transmission time relative to the reference time, or the initial gating scheduling parameters. The initial gating scheduling parameters are used by the second device to transmit the first service flow through the second path at the initial service flow transmission time.

[0031] In conjunction with the second aspect mentioned above, in one possible implementation, the first service flow is a downlink service flow; the interface configuration information also includes second interface configuration information, which is used by the second device to send the first service flow to the target access network device through the forwarding path during the second service flow transmission time; wherein, the updated interface configuration information also includes the second interface configuration information. Based on this scheme, deterministic transmission between the target access network device and the user plane network element can be satisfied in terminal device mobility scenarios when the first service flow is transmitted on the forwarding path.

[0032] In conjunction with the second aspect described above, in one possible implementation, the updated interface configuration information also includes a second identifier, which indicates that the second interface configuration information is the interface configuration information corresponding to the forwarding path. Based on this scheme, it is easier to distinguish multiple sets of interface configuration information stored on the second device.

[0033] In conjunction with the second aspect described above, in one possible implementation, the switching method provided in this application further includes: the second device receiving fifth indication information from the first device; the second device deleting second interface configuration information according to the fifth indication information; or, after the second device sends a data packet with an end marker corresponding to the first service flow to the source access network device, the second device deletes the second interface configuration information. Based on this scheme, the second device can promptly delete the second interface configuration information when it is not needed, thereby saving the storage resources of the second device.

[0034] In conjunction with the second aspect described above, in one possible implementation, the switching method provided in this application embodiment further includes: after the second device obtains the tunnel information of the target access network device, the second device sends the first service flow through a forwarding path according to the second interface configuration information. This solution provides a solution for when to use the second interface configuration information when multiple sets of interface configuration information are stored simultaneously on the second device. It can be understood that in this application embodiment, the second device sending the first service flow through a forwarding path according to the second interface configuration information can also be understood as the second device updating the interface configuration information mapped to the first service flow to the second interface configuration information. This will be uniformly explained here and will not be repeated below.

[0035] In conjunction with the second aspect above, in one possible implementation, the second interface configuration information includes information about the second service flow sending time.

[0036] In conjunction with the second aspect above, in one possible implementation, the information on the second service flow transmission time includes at least one of the following: the second service flow transmission time, the offset of the second service flow transmission time relative to the reference time, or a second gating scheduling parameter. The second gating scheduling parameter is used by the second device to transmit the first service flow through the forwarding path during the second service flow transmission time.

[0037] In conjunction with the second aspect above, in one possible implementation, the forwarding path consists of a path from the first user plane network element to the source access network device and a path from the source access network device to the target access network device; or, the forwarding path consists of a path from the first user plane network element to the second user plane network element, a path from the second user plane network element to the source access network device, a path from the source access network device to the second user plane network element, and a path from the second user plane network element to the target access network device.

[0038] Thirdly, a communication device is provided for implementing the various methods described above. This communication device can be the first device described in the first aspect, or a device comprising the first device, or a device included in the first device, such as a chip or chip system. The communication device includes modules, units, or means corresponding to the methods described above, which can be implemented in hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the functions described above.

[0039] In conjunction with the third aspect described above, in one possible implementation, the communication device may include a processing module and a transceiver module. This transceiver module, also referred to as a transceiver unit, is used to implement the sending and / or receiving functions in the first aspect and any of its possible implementations. The transceiver module may consist of a transceiver circuit, a transceiver, a transceiver unit, or a communication interface. The processing module can be used to implement the processing functions in the first aspect and any of its possible implementations.

[0040] In conjunction with the third aspect above, in one possible implementation, the transceiver module includes a sending module and a receiving module, which are used to implement the sending and receiving functions in the first aspect above and any possible implementation thereof.

[0041] The communication device provided by the third aspect is used to execute the first aspect or any possible implementation of the first aspect. For details, please refer to the first aspect or any possible implementation of the first aspect, which will not be repeated here.

[0042] Fourthly, a communication device is provided for implementing the various methods described above. This communication device can be the second device described in the second aspect, or a device comprising the second device, or a device included in the second device, such as a chip or chip system. The communication device includes modules, units, or means corresponding to the methods described above, which can be implemented in hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the functions described above.

[0043] In conjunction with the fourth aspect above, in one possible implementation, the communication device may include a processing module and a transceiver module. This transceiver module, also referred to as a transceiver unit, is used to implement the sending and / or receiving functions in the second aspect above and any possible implementation thereof. The transceiver module may consist of a transceiver circuit, a transceiver, a transceiver unit, or a communication interface. The processing module can be used to implement the processing functions in the second aspect above and any possible implementation thereof.

[0044] In conjunction with the fourth aspect above, in one possible implementation, the transceiver module includes a sending module and a receiving module, which are used to implement the sending and receiving functions in the second aspect above and any possible implementation thereof.

[0045] The communication device provided in the fourth aspect is used to execute the second aspect or any possible implementation of the second aspect. For details, please refer to the second aspect or any possible implementation of the second aspect, which will not be repeated here.

[0046] Fifthly, a communication device is provided, comprising: a processor; the processor being coupled to a memory and, after reading instructions from the memory, executing the method as described in any of the preceding aspects according to the instructions. The communication device may be a first device as described in the first aspect, or an apparatus including the first device; or, the communication device may be a second device as described in the second aspect, or an apparatus including the second device.

[0047] In conjunction with the fifth aspect above, in one possible implementation, the communication device further includes a memory for storing necessary program instructions and data.

[0048] In conjunction with the fifth aspect above, in one possible implementation, the communication device is a chip or a chip system. Optionally, when the communication device is a chip system, it can be composed of chips or may include chips and other discrete components.

[0049] A sixth aspect provides a communication device, comprising: a processor and an interface circuit; the interface circuit is configured to receive signals from other communication devices outside the communication device and transmit them to the processor, or to send signals from the processor to other communication devices outside the communication device, wherein the processor implements the method as described in any of the preceding aspects via logic circuits or by executing code instructions.

[0050] In conjunction with the sixth aspect above, in one possible implementation, the communication device is a chip or a chip system. Optionally, when the communication device is a chip system, it can be composed of chips or may include chips and other discrete components.

[0051] In a seventh aspect, a computer-readable storage medium is provided, which stores instructions that, when executed on a computer, cause the computer to perform the methods described in any of the preceding aspects.

[0052] Eighthly, a computer program product containing instructions is provided, which, when run on a computer, enables the computer to perform the methods described in any of the preceding aspects.

[0053] The technical effects of any possible implementation of aspects three through eight can be found in the technical effects of any of aspects one through two or different design methods, and will not be repeated here.

[0054] A ninth aspect provides a communication system comprising a first device for performing the switching method described in the first aspect and a second device for performing the switching method described in the second aspect. Attached Figure Description

[0055] Figure 1 This is a diagram illustrating the centralized management architecture of TSN;

[0056] Figure 2 This is a schematic diagram of the transmission path of the first service flow in a 5G system.

[0057] Figure 3 This is a schematic diagram of the TSN architecture;

[0058] Figure 4A A 5G system architecture defined in 3GPP TS23.501;

[0059] Figure 4B Another 5G system architecture defined in 3GPP TS23.501;

[0060] Figure 5A System architecture diagram for interoperability between 3GPP networks and TSN systems;

[0061] Figure 5B System architecture diagram for interoperability between 3GPP networks and non-TSN TSC systems;

[0062] Figure 6 This is a schematic diagram of the long-tail effect;

[0063] Figure 7A This is a schematic diagram of an architecture used in an embodiment of this application;

[0064] Figure 7B This is a schematic diagram of another architecture used in an embodiment of this application;

[0065] Figure 8A This is a schematic diagram of another architecture used in an embodiment of this application;

[0066] Figure 8B This is a schematic diagram of another architecture used in an embodiment of this application;

[0067] Figure 9 This is a schematic diagram of another architecture used in an embodiment of this application;

[0068] Figure 10 This is a schematic diagram of the architecture of the communication system provided in the embodiments of this application;

[0069] Figure 11 This is a schematic diagram of the structure of the communication device provided in the embodiments of this application;

[0070] Figure 12A A schematic diagram of the transmission path of the first service flow when the first service flow is an uplink service flow, as provided in the embodiments of this application;

[0071] Figure 12B A schematic diagram of the transmission path of the first service flow when the first service flow is a downlink service flow, provided for embodiments of this application;

[0072] Figure 13A This application provides a schematic diagram illustrating the relationship between different PDBs in an uplink scenario.

[0073] Figure 13B This is a schematic diagram illustrating the relationship between different PDBs in another uplink scenario provided in this application embodiment;

[0074] Figure 13C This application provides a schematic diagram illustrating the relationship between different PDBs in a downlink scenario.

[0075] Figure 13D This is a schematic diagram illustrating the relationship between different PDBs in another downlink scenario provided in this application embodiment;

[0076] Figure 14 A flowchart illustrating a switching method provided in an embodiment of this application;

[0077] Figure 15 A schematic diagram of the first path provided for an embodiment of this application;

[0078] Figure 16 A schematic diagram of a gated state provided in an embodiment of this application;

[0079] Figure 17 This is another schematic diagram of a gating state provided in an embodiment of this application;

[0080] Figure 18 This is another schematic diagram of a gated state provided in an embodiment of this application;

[0081] Figure 19 This is another schematic diagram of a gated state provided in an embodiment of this application;

[0082] Figure 20 This is another schematic diagram of a gated state provided in an embodiment of this application;

[0083] Figure 21 This is another schematic diagram of a gated state provided in an embodiment of this application;

[0084] Figure 22 A schematic diagram of the second path provided in the embodiments of this application;

[0085] Figure 23 A schematic diagram of a forwarding path provided in an embodiment of this application;

[0086] Figure 24A A schematic diagram illustrating another forwarding path provided in an embodiment of this application;

[0087] Figure 24B A schematic diagram illustrating a forwarding path when there is no intermediate user plane network element handover, as provided in an embodiment of this application;

[0088] Figure 24C A schematic diagram illustrating a forwarding path during intermediate user plane network element handover, provided as an embodiment of this application;

[0089] Figure 25 A flowchart illustrating another switching method provided in an embodiment of this application;

[0090] Figure 26 An interactive schematic diagram of a handover method in an uplink scenario provided in an embodiment of this application;

[0091] Figure 27 An interactive schematic diagram of a handover method in a downlink scenario provided in an embodiment of this application;

[0092] Figure 28 An interactive schematic diagram of another downlink scenario handover method provided in an embodiment of this application;

[0093] Figure 29 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0094] To facilitate understanding of the solutions in the embodiments of this application, a brief introduction to the TSN system and 5GS is given below:

[0095] See Figure 1 This diagram illustrates the centralized management architecture of TSN, one of the three architectures defined in the TSN standard 802.1qcc. This centralized management architecture includes CNC network elements, CUC network elements, TSN endpoints (endstations), and various switching nodes (TSN Bridges). TSN endpoints include talkers and listeners.

[0096] It should be noted that, Figure 1 The number of network elements and network topology shown are merely examples, and this application does not impose specific limitations on them. The following... Figure 1 Here is a brief introduction to the functions of each device:

[0097] The CUC network element is responsible for discovering and managing TSN terminals. For example, the CUC network element can obtain the service flow requirements of the TSN terminal and send a flow creation request carrying the service flow requirements to the CNC network element; or, the CUC network element can configure the TSN terminal according to the instructions of the CNC network element.

[0098] The CNC network element is responsible for managing the topology of the TSN user plane (including the topology between each TSN terminal and switching node) and the capability information of the switching nodes. Based on the flow creation request carrying service flow requirements provided by the CNC network element, it generates end-to-end (E2E) paths for service flows and forwarding rules on each switching node. Then, it distributes the forwarding rules (such as flow characteristics of the service flow, identifiers of ingress and egress ports during service transmission), and scheduling information (such as time information of ingress ports and flow classification information corresponding to egress ports) to the corresponding switching nodes. The descriptions of the time information of ingress ports and the flow classification information corresponding to egress ports can be found in existing technologies and will not be repeated here.

[0099] It is understood that in the embodiments of this application, the CNC network element and the CUC network element are control plane network elements or configuration network elements in the TSN system.

[0100] A TSN terminal consists of a talker and a listener. The sender of the service flow is called the talker, and the receiver of the service flow is called the listener.

[0101] The switching node is responsible for reporting its capability and topology information to the CNC network element, and scheduling and forwarding service flows according to the forwarding rules and scheduling information issued by the CNC network element. In addition to service flow forwarding, the switching nodes in the TSN also have other functions, such as topology discovery, determining the identifier and port identifier of the switching node, supporting protocols such as the Link Layer Discovery Protocol (LLDP), and determining transmission delay. Furthermore, upon detecting the internal transmission delay of the switching node, it reports the detected transmission delay to the CNC network element. This application embodiment does not specifically limit these functions.

[0102] In this embodiment, TSN terminals and switching nodes can form a network topology. Currently, there are various network topologies formed by TSN terminals and switching nodes, which can be configured according to the application scenario. See also... Figure 3 This is a schematic diagram of a network topology for TSN, which includes multiple domains ( Figure 3 (The example illustrates multiple domains, including domain 1, domain 2, domain 3, and domain 4. Each domain includes one or more TSN terminals and one or more switching nodes. Devices and ports within the same domain share the same domain identifier (e.g., traffic class).

[0103] It should be noted that the TSN terminal in this application embodiment can also be called a data terminal, and the following description only uses the TSN terminal as an example; the data packet in this application embodiment can also be called a message, data packet, data frame or frame, etc., and the following description only uses the data packet as an example; the service flow in this application embodiment can also be called a data flow, and the following description only uses the service flow as an example. This will be explained uniformly here and will not be repeated below.

[0104] Specifically, based on Figure 1 The specific implementation of TSN configuration using the centralized management architecture shown can be found in existing technologies and will not be elaborated here.

[0105] See Figure 4AThis refers to the 5G system architecture defined by 3GPP technology standard (TS) 23.501. This 5G system architecture is divided into two parts: the access network and the core network. The access network implements radio access-related functions. Access network elements include gNBs. The core network mainly includes the following network elements: access and mobility management function (AMF) elements, session management function (SMF) elements, UPF elements, policy control function (PCF) elements, network exposure function (NEF) elements, or application function (AF) elements, etc.

[0106] Specifically, the terminal equipment communicates with the AMF network element through the next-generation (N)1 interface (N1), the gNB communicates with the AMF network element through the N2 interface (N2), the gNB communicates with the UPF network element through the N3 interface (N3), the UPF network element communicates with the DN through the N6 interface (N6), the AMF network element communicates with the SMF network element through the N11 interface (N11), the AMF network element communicates with the PCF network element through the N15 interface (N15), the SMF network element communicates with the PCF network element through the N7 interface (N7), and the SMF network element communicates with the UPF network element through the N4 interface (N4). Optionally, the PCF network element communicates with the AF network element through the NEF network element; for example, the PCF network element communicates with the NEF network element through the N30 interface (N30), and the NEF network element communicates with the AF network element through the N33 interface (N33). Of course, the AF network element can also communicate directly with the PCF network element or the SMF network element. For example, the AF network element can communicate with the PCF network element through the N5 interface (N5 for short). This application embodiment does not specifically limit this.

[0107] It should be noted that, Figure 4A The control plane network elements shown, such as AF, AMF, SMF, PCF, or NEF network elements, can also interact using service-oriented interfaces. For example, ... Figure 4BAs shown, the service interface provided by the AF network element can be Naf; the service interface provided by the AMF network element can be Namf; the service interface provided by the SMF network element can be Nsmf; the service interface provided by the PCF network element can be Npcf; and the service interface provided by the NEF network element can be Nnef. For relevant descriptions, please refer to the 5G system architecture in the 23501 standard, which will not be elaborated upon here.

[0108] It should be noted that, Figure 4A and Figure 4B The 5G system architecture described above is merely an example listing some network elements required for the embodiments of this application. Of course, the 5G system architecture defined by 3GPP is not limited to the above network elements, and may also include unified data management (UDM) network elements, unified data repository (UDR) network elements, authentication server function (AUSF) network elements, etc. The embodiments of this application do not specifically limit these.

[0109] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. In the description of this application, unless otherwise stated, " / " indicates that the objects before and after are in an "or" relationship. For example, A / B can represent A or B. "And / or" in this application is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone, where A and B can be singular or plural. Furthermore, in the description of this application, unless otherwise stated, "multiple" refers to two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple. Furthermore, to facilitate a clear description of the technical solutions in the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that "first" and "second" are not necessarily different. Meanwhile, in the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is being used as an example, illustration, or description. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of terms such as "exemplary" or "for example" is intended to present related concepts in a concrete manner for ease of understanding.

[0110] Furthermore, the network architecture and business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0111] like Figure 5A The diagram illustrates a system architecture for interoperability between a 3GPP network and a TSN system. The 5GS acts as a single switching node. The TSN AF network element within the 5GS interacts with nodes in the TSN system.

[0112] It should be noted that the DS-TT may be located inside or outside the terminal device; the NW-TT may be located within the UPF network element. Taking a downstream data packet as an example, the DS-TT can determine the gating scheduling parameters based on the configuration information sent by the CNC network element, and send data packets according to the gating scheduling parameters. To ensure timely transmission of data packets, the arrival time of the data packet at the DS-TT cannot be later than a certain time, ensuring that it can be sent during the gate opening process. The gate opening process refers to the duration within which the gate state is open. If the data packet arrives at the DS-TT before the start time of the gate opening state indicated by the gating scheduling parameters, it needs to be buffered at the DS-TT until the gate state is open before transmission. If the data packet arrives at the DS-TT after the start time of the gate opening state indicated by the gating scheduling parameters, the DS-TT needs to complete the transmission of the data packet before the gate state transitions to the closed state. Similarly, the NW-TT can also determine the gating scheduling parameters based on the configuration information sent by the CNC network element, and send data packets according to the gating scheduling parameters. For example, NW-TT can send uplink traffic received through 5GS to the next-hop switching node adjacent to 5GS on the E2E path, or NW-TT can receive downlink traffic from the previous-hop switching node adjacent to 5GS on the E2E path and send it to 5GS.

[0113] like Figure 5B The diagram illustrates a system architecture for interoperability between a 3GPP network and a non-TSN (Time Sensitive Communication) Time-Sensitive Communication (TSC) system. In non-TSN scenarios, clock synchronization services are supported through the Time Sensitive Communication and Time Synchronization Function (TSCTSF) network element, enabling TSC services in non-TSN scenarios. In 5GS, the TSCTSF network element directly exchanges information with the AF (Active Front-End) network element, or the TSCTSF network element interacts with the AF network element through the NEF (Non-Active Front-End) network element. For example... Figure 5B As shown, the TSCTSF network element communicates with the PCF network element through the N84 interface (N84 for short), and the TSCTSF network element communicates with the NEF network element through the N85 interface (N85 for short).

[0114] like Figure 2As shown, in deterministic low-latency scenarios, such as certain industrial control scenarios, very low end-to-end latency is required. For example, the latency between the terminal device (or DS-TT) and the UPF network element (or NW-TT) must be less than 2ms. The transmission between the gNB and the UPF network element uses tunnel mode. This means that when a data packet of a service flow arrives at the output port of the gNB, UPF network element, or the transmission node (e.g., a switch) between the gNB and UPF network elements, the data packet is sent directly without waiting, provided there are available transmission resources. However, when data packets from several service flows arrive at the output port of one of these nodes simultaneously (i.e., a micro-burst scenario), congestion may cause a longer transmission delay between the gNB and the UPF network element, for example, exceeding 0.5ms. This results in the end-to-end transmission latency failing to meet service requirements, for example, exceeding 2ms, thus affecting the achievement of low end-to-end latency. It is understandable that the transmission path between the gNB and the UPF network element may also include at least one transmission node (…). Figure 5A and Figure 5B (Not shown in the image), this transmission node can be a switch (such as...) Figure 2 (as shown) or routers, etc.

[0115] like Figure 6 As shown, in micro-burst scenarios, the delay distribution of data packets exhibits a long-tail effect, such as... Figure 6 As shown in the left-hand diagram, the maximum latency has no upper boundary or the upper boundary is a very large value, causing the end-to-end latency to exceed the service's transmission latency requirements. To achieve low end-to-end latency, the packet latency needs to be limited to a range, such as... Figure 6 As shown in the right-hand figure, it is necessary to limit the time delay jitter between the gNB and UPF network elements to a certain time range.

[0116] To solve the above problems, the following approach is adopted: Figure 1 The TSN system shown follows a similar principle, and will Figure 2 In this system, gNB and UPF network elements are considered as TSN terminals, transmission nodes (e.g., switches) between gNB and UPF network elements are considered as switching nodes, and SMF network elements are considered as CUC network elements. Low transmission latency between gNB and UPF network elements can also be achieved through the relevant configuration of gNB and UPF network elements by SMF network elements.

[0117] In one possible implementation, embodiments of this application can be applied to, for example... Figure 7A and Figure 7B In domain2 shown, low transmission latency is implemented between the gNB and UPF network elements. Among them, Figure 7A The network architecture is suitable for TSN scenarios. Figure 7B The network architecture is suitable for TSC scenarios that are not TSN.

[0118] For example, such as Figure 7A As shown, Figure 7A It involves two domains, where domain 1 uses... Figure 5A The architecture shown includes TSN terminals, user plane network elements in the 5GS (such as terminal devices, gNB and UPF network elements, and the switches between them), and other TSN switching nodes; the control plane includes various control plane network elements in the 5GS (such as SMF network elements, PCF network elements, and TSN AF network elements), CUC network elements, and CNC network elements. The TSN AF network elements in the 5GS interact with the CNC network elements in the TSN system. The dashed box in domain 1 constitutes domain 2, as shown... Figure 7A The upper half is indicated by the middle arrow. In domain 2, the user plane includes the gNB and UPF network elements in 5GS and the switches between them, while the control plane includes the SMF network element, the CNC-transport network (TN) network element, the TSN AF network element, and the PCF network element.

[0119] In domain 2, a converter corresponding to the gNB is added on the gNB side. The converter corresponding to the gNB can be denoted as AN-TT (e.g., ...). Figure 7A (As shown). AN-TT is used to achieve deterministic transmission between the gNB and UPF network elements, which will be described in detail with reference to the flowchart below. AN-TT can be located inside or outside the gNB. When AN-TT is located inside the gNB, it can be understood as a functional module integrated within the gNB. Alternatively, when AN-TT is located outside the gNB, it can be understood as two separately deployed devices. In this case, AN-TT can be deployed between the gNB and the terminal device, or between the gNB and the UPF network element.

[0120] In addition, another converter corresponding to the UPF network element is added on one side of the UPF network element. This converter is located inside the UPF network element. That is, the UPF network element integrates the functional modules of two converters. One converter is the aforementioned NW-TT, and the other converter can be referred to as the N3 interface converter, i.e., N3-TT (e.g., Figure 7A(As shown). The newly added N3-TT is used to implement deterministic transmission between the gNB and the UPF network element, which will be described in detail with reference to the flowchart below. Alternatively, the functionality of the existing NW-TT can be enhanced to include the functions of the N3-TT described above. In this way, a converter functional module is retained within the UPF network element. In addition, if an intermediate UPF (I-UPF) network element is included in the path between the gNB and the UPF network element, the newly added converter can be designated as N9-TT. The following explanation only uses the N3-TT as an example of the newly added converter.

[0121] Furthermore, the two newly added converters mentioned above may also have other names, which are not limited herein.

[0122] pass Figure 7A The network architecture layout shown can meet the deterministic latency requirements of user plane devices in both domain 1 and domain 2 when transmitting service flows.

[0123] For example, such as Figure 7B As shown, Figure 7B It also involves two domains, with domain 1 using... Figure 5B The architecture shown includes endstation devices, user plane network elements in the 5GS (such as terminal devices, gNB and UPF network elements, and the switches between them), and other switching nodes, such as the switching nodes in the DN. The control plane includes various control plane network elements of the 5GS (such as SMF network elements, PCF network elements, and TSCTSF network elements) and AF network elements. The dashed box in domain 1 constitutes domain 2, as shown... Figure 7B The upper half is indicated by the middle arrow. In domain 2, the user plane includes the gNB and UPF network elements in 5GS and the switches between them, while the control plane includes the SMF, CNC-TN, TSCTSF, and PCF network elements. Similarly, AN-TT and N3-TT have been added in domain 2; see details below. Figure 7A The description in [the document] will not be repeated here. Through [the following]... Figure 7B The network architecture layout shown can meet the deterministic latency requirements of user plane devices in both domain 1 and domain 2 when transmitting service flows.

[0124] In another possible implementation, embodiments of this application can be applied to, for example... Figure 8A and Figure 8B In domain2 shown, low transmission latency is implemented between the gNB and UPF network elements. Among them, Figure 8AThe network architecture is suitable for TSN scenarios. Figure 8B The network architecture is suitable for TSC scenarios that are not TSN.

[0125] For example, such as Figure 8A As shown, domain 1 and domain 2 can be referenced above. Figure 7A The relevant description in [the document / article]. With Figure 7A The difference lies in, Figure 8A In the network architecture shown, the TSN AF network element is connected to the CNC-TN network element, and information can be exchanged through the interface between the TSN AF network element and the CNC-TN network element.

[0126] For example, such as Figure 8B As shown, domain 1 and domain 2 can be referenced above. Figure 7B The relevant description in [the document / article]. With Figure 7B The difference lies in, Figure 7B In the network architecture shown, the TSCTSF network element is connected to the CNC-TN network element, and information can be exchanged between the TSCTSF network element and the CNC-TN network element through the interface between them.

[0127] In yet another possible implementation, embodiments of this application can be applied to, for example... Figure 9 In domain2 shown, low transmission latency is implemented between the gNB and UPF network elements. Among them, Figure 9 For a description of domain1 shown, please refer to [link / reference]. Figure 7A The description of domain1 shown will not be repeated here. Figure 9 As shown, in domain 2, the user plane includes the gNB and UPF network elements in the 5GS and the switches between them, while the control plane includes the element manager (EM), network manager (NM), and CNC-CN network elements. The EM provides element management functions, managing one or more network elements. The NM provides network management functions, managing the network between the network elements managed by the EM.

[0128] It should be noted that, regarding the above Figure 7A , Figure 7B , Figure 8A , Figure 8B and Figure 9The forwarding behavior of domain 1 and domain 2 in the user plane can be independent. That is, when controlling the forwarding behavior of 5GS, the control plane of domain 1 treats 5GS as a whole, without considering the transmission between the terminal equipment and gNB, or between gNB and UPF network elements within 5GS. However, when controlling the forwarding behavior of the switching nodes in domain 2, the control plane of domain 2 treats gNB and UPF network elements as the sender and receiver of the service flow respectively when the service flow is uplink, or treats AN-TT and N3-TT as the sender and receiver of the service flow respectively. When the service flow is downlink, UPF network elements and gNB are treated as the sender and receiver of the service flow respectively, or N3-TT and AN-TT as the sender and receiver of the service flow respectively. The timing of data packet transmission by the sender is limited by the time the 5GS node in domain 1 receives data packets from the upstream switching node, but the specific transmission and forwarding behavior is not affected or controlled by domain 1. This is explained uniformly here and will not be elaborated further below.

[0129] It should be noted that, regarding the above Figure 7A , Figure 7B , Figure 8A , Figure 8B and Figure 9 These examples are all illustrative, using the SMF network element as a CUC network element as an example. Of course, other control plane network elements in 5GS can also be regarded as CUC network elements, or the functions of CUC network elements can be integrated into other control plane network elements in 5GS. This application does not specifically limit this.

[0130] Based on the above Figure 7A , Figure 7B , Figure 8A , Figure 8B and Figure 9 The network architecture shown can achieve low transmission latency between gNB and UPF network elements. However, in terminal device mobility scenarios, if a terminal device switches from its currently accessed RAN device (denoted as the source RAN device) to another RAN device (denoted as the target RAN device), there is currently no solution to ensure deterministic transmission between the target RAN device and the UPF network element.

[0131] Based on this, embodiments of this application provide a communication system 100, and the handover method based on this communication system 100 can satisfy the deterministic transmission between the target access network device and the user plane network element in a terminal device mobility scenario. For example... Figure 10As shown, the communication system 100 includes a first device 1001 and a second device 1002. The first device 1001 is used to determine the interface configuration information for the second device 1002 when a first service flow switches from a source access network device serving a terminal device to a target access network device serving the terminal device, and sends the interface configuration information to the second device 1002. The second device 1002 is used to receive the interface configuration information from the first device 1001, configure the interface according to the interface configuration information, and then notify the first device 1001 that the interface configuration is complete. The first device 1001 is also used to notify the target access network device or the source access network device to execute the handover execution procedure after learning from the second device 1002 that the interface configuration associated with the interface configuration information is complete. Wherein, if the first service flow is an uplink service flow, the second device is the target access network device or the converter corresponding to the target access network device; if the first service flow is a downlink service flow, the second device is the first user plane network element. The specific implementation and technical effects of this scheme can be referred to in subsequent method embodiments, and will not be repeated here.

[0132] Optionally, in this embodiment, the first device 1001 can be a session management network element, a TSN application function network element, a network element with time-sensitive communication and clock synchronization functions, or a network management device, etc. This embodiment does not specifically limit this.

[0133] Optional, such as Figure 10 As shown, the communication system 100 may further include a third device 1003, and a first path is formed between the second device 1002 and the third device 1003. Wherein, if the first service flow is an uplink service flow, the third device is a first user plane network element; if the first service flow is a downlink service flow, the third device is a target access network device or a converter corresponding to the target access network device.

[0134] The above-mentioned network elements will be introduced separately below.

[0135] Optionally, the terminal device in this application embodiment can be a device for implementing wireless communication functions, such as a terminal or a chip that can be used in the terminal. It can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it can also be deployed on water (such as ships); and it can also be deployed in the air (such as airplanes, balloons, and satellites). Among them, the terminal can be user equipment (UE), access terminal, terminal unit, terminal station, mobile station, mobile station, remote station, remote terminal, mobile device, wireless communication device, terminal agent, or terminal device in a 5G network or a future evolved public land mobile network (PLMN). Access terminals can be cellular phones, cordless phones, Session Initiation Protocol (SIP) phones, Wireless Local Loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to a wireless modem, in-vehicle devices or wearable devices, virtual reality (VR) terminal devices, augmented reality (AR) terminal devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical care, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, etc. Terminals can be mobile or fixed.

[0136] Optionally, the access network device (including the aforementioned source access network device and target access network device) in this application embodiment can be any communication device with wireless transceiver capabilities used to communicate with terminal devices. This access network device includes, but is not limited to: evolved node B (eNB), baseband unit (BBU), access point (AP), wireless relay node, wireless backhaul node, transmission point (TP), or transmission receiver point (TRP) in a wireless fidelity (WIFI) system. This access network device can also be a RAN device in 5GS, which includes, for example, a gNB (e.g., Figure 7A , Figure 7B , Figure 8A , Figure 8B or Figure 9 The RAN device can be a gNB (gNB), TRP (Telecommunications Base Station), or TP (Telecommunications Platform), or one or a group of antenna panels (including multiple antenna panels) of a base station in 5GS. Furthermore, the RAN device can also be a network node constituting a gNB or TP, such as a BBU (Broadband Unit), or a distributed unit (DU), etc., but this application does not specifically limit this.

[0137] Optionally, the converter corresponding to the access network device in this embodiment can be, for example, the one described above. Figure 7A , Figure 7B , Figure 8A , Figure 8B or Figure 9 AN-TT in.

[0138] Optionally, the session management network element in this embodiment is used for session management. For example, session establishment, modification, and release. The session management network element is also used to assign Internet Protocol (IP) addresses to terminal devices and select user plane network elements that provide packet forwarding functions. In 5GS, the session management network element can be an SMF network element, for example... Figure 7A or Figure 7B The SMF network element in the context of this application. In future mobile communication systems such as the 6th generation (6G) mobile communication system, the session management function network element can still be an SMF network element, or it may have other names; this application does not limit this.

[0139] Optionally, the user plane network elements in this embodiment (including the first user plane network element mentioned above and other user plane network elements such as the second user plane network element described below) are mainly responsible for processing data packets of the terminal device, such as forwarding and billing. Furthermore, the first user plane network element in this embodiment can also be called a Protocol Data Unit (PDU) session anchor (PSA), which remains unchanged before and after the terminal device handover. In 5GS, the user plane network element can be a UPF network element, for example... Figure 7A , Figure 7B , Figure 8A , Figure 8B or Figure 9 The UPF network element in this context. In future communication systems such as 6G communication, the user plane network element can still be a UPF network element, or it may have other names; this application does not limit this.

[0140] Optionally, the converter corresponding to the user plane network element in this application embodiment can be, for example, the one described above. Figure 7A , Figure 7B , Figure 8A , Figure 8B or Figure 9 N3-TT in.

[0141] Optionally, the TSN application function network element in this application embodiment can be, for example, a network element that enables TSN application functions. Figure 8A The TSN AF network element is mentioned. Of course, the TSN application function network element can also be other, and this application embodiment does not specifically limit it.

[0142] Optionally, the network element with time-delay-sensitive communication and clock synchronization functions in the embodiments of this application can be, for example, a network element with time-delay-sensitive communication and clock synchronization functions. Figure 8B The TSCTSF network element is used in this application. Of course, other network elements can also have time-delay-sensitive communication and clock synchronization functions, and this application does not specifically limit them.

[0143] Optionally, the network management device in this application embodiment can be, for example, a... Figure 9 The NM in this context. Of course, the network management device can be other types as well, and this application does not specifically limit this.

[0144] Although not shown, optionally, the communication system 100 provided in this application embodiment may further include a fourth device, which may be, for example, a centralized network configuration element. Figure 7A , Figure 7B , Figure 8A , Figure 8B or Figure 9The CNC-TN network element in the first device can be a new network element with the functions of a CNC network element, or it can be a functional module in the first device. This application does not limit this.

[0145] Optionally, the first or second device in the embodiments of this application may also be referred to as a communication device or communication equipment. It may be a general-purpose device or a special-purpose device. The embodiments of this application do not specifically limit it in this regard.

[0146] Optionally, the relevant functions of the first or second device in the embodiments of this application can be implemented by one device, multiple devices working together, or one or more functional modules within a single device. This application does not specifically limit these functions. It is understood that the aforementioned functions can be network elements in hardware devices, software functions running on dedicated hardware, a combination of hardware and software, or virtualization functions instantiated on a platform (e.g., a cloud platform).

[0147] For example, the relevant functions of the first or second device in the embodiments of this application can be achieved through... Figure 11 This is achieved through the communication device 1100. Figure 11 The diagram shown is a structural schematic of a communication device 1100 provided in an embodiment of this application. The communication device 1100 includes one or more processors 1101, a communication line 1102, and at least one communication interface. Figure 11 (This is merely an example illustration, using a communication interface 1104 and a processor 1101 as examples. Optionally, it may also include a memory 1103.)

[0148] The processor 1101 may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits used to control the execution of the program of the present application.

[0149] The communication line 1102 may include a path for connecting different components.

[0150] The communication interface 1104 can be a transceiver module used to communicate with other devices or communication networks, such as Ethernet, RAN, wireless local area networks (WLAN), etc. For example, the transceiver module can be a transceiver or a similar device. Optionally, the communication interface 1104 can also be a transceiver circuit located within the processor 1101, used to implement the processor's signal input and signal output.

[0151] The memory 1103 can be a device with storage function. For example, it can be read-only memory (ROM) or other types of static storage devices capable of storing static information and instructions; random access memory (RAM) or other types of dynamic storage devices capable of storing information and instructions; electrically erasable programmable read-only memory (EEPROM); compact disc read-only memory (CD-ROM) or other optical disc storage; optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.); magnetic disk storage media or other magnetic storage devices; or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. The memory can exist independently and be connected to the processor via communication line 1102. The memory can also be integrated with the processor.

[0152] The memory 1103 stores computer execution instructions for implementing the scheme of this application, and its execution is controlled by the processor 1101. The processor 1101 executes the computer execution instructions stored in the memory 1103, thereby implementing the switching method provided in the embodiments of this application.

[0153] Alternatively, in this embodiment, the processor 1101 may execute the processing-related functions in the switching method provided in the following embodiments of this application, and the communication interface 1104 may be responsible for communicating with other devices or communication networks. This embodiment does not specifically limit this.

[0154] Optionally, the computer execution instructions in the embodiments of this application may also be referred to as application code, and the embodiments of this application do not specifically limit this.

[0155] In a specific implementation, as one example, the processor 1101 may include one or more CPUs, for example... Figure 11 CPU0 and CPU1 in the CPU.

[0156] In a specific implementation, as one embodiment, the communication device 1100 may include multiple processors, for example... Figure 11The processors 1101 and 1108 are described herein. Each of these processors may be a single-core processor or a multi-core processor. The processors herein may include, but are not limited to, at least one of the following: a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), a microcontroller unit (MCU), or an artificial intelligence processor, and other computing devices that run software. Each computing device may include one or more cores for executing software instructions to perform calculations or processing.

[0157] In a specific implementation, as one embodiment, the communication device 1100 may further include an output device 1105 and an input device 1106. The output device 1105 communicates with the processor 1101 and can display information in various ways. For example, the output device 1105 may be a liquid crystal display (LCD), a light-emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector, etc. The input device 1106 communicates with the processor 1101 and can receive user input in various ways. For example, the input device 1106 may be a mouse, keyboard, touchscreen device, or sensing device, etc.

[0158] The aforementioned communication device 1100 may sometimes be referred to as a communication equipment, which can be a general-purpose device or a dedicated device. For example, the communication device 1100 may be a desktop computer, a portable computer, a network server, a handheld digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, an embedded device, the aforementioned terminal equipment, the aforementioned network equipment, or a device with... Figure 11 Devices with similar structures. This application does not limit the type of communication device 1100 to any particular embodiment.

[0159] The switching method provided in the embodiments of this application will be described below in conjunction with specific scenarios.

[0160] First, the following are exemplary descriptions of the upstream business flow scenario (i.e., scenario 1) and the downstream business flow scenario (i.e., scenario 2) involved in the switching method provided in the embodiments of this application.

[0161] Scenario 1: When the service flow (e.g., the first service flow in the embodiments of this application) is an uplink service flow, the second device is the target access network device or the converter corresponding to the target access network device, that is, the service flow is the uplink service flow that the target access network device is to send to the first user plane network element.

[0162] In this embodiment, the second device being the target access network device or the converter corresponding to the target access network device can be understood as follows: If the converter corresponding to the target access network device is deployed separately from the target access network device, the second device can be the converter corresponding to the target access network device. For example, the service flow arrival time can be the time when the service flow arrives at the converter corresponding to the target access network device (e.g., the AN-TT mentioned above). If the converter corresponding to the target access network device is a functional module within the target access network device, the second device can be the target access network device that includes converter functionality; that is, the second device can be the target access network device. Accordingly, the service flow arrival time can be the time when the service flow arrives at the target access network device. For example, the service flow arrival time can be the time when the service flow arrives at the Packet Data Convergence Protocol (PDCP) layer or the Service Data Adaptation Protocol (SDAP) layer of the target access network device.

[0163] At this point, after the terminal device switches from the source access network device to the target access network device, the transmission path of the service flow in the mobile communication system includes at least: the terminal device, the target access network device, and the first user plane network element. Optionally, at least one switch or router may also be included between the target access network device and the first user plane network element on this transmission path.

[0164] For example, such as Figure 12A As shown, 5GS is used as switching node 2, and the service flow is an uplink service flow. The entire forwarding path of the service flow is: Talker, Switching Node 1, Switching Node 2, Switching Node 3, Listener. The transmission path of the service flow in 5GS (i.e., switching node 2) is: DS-TT, terminal equipment, target gNB, UPF1 network element (or NW-TT). The transmission path of the service flow from the target gNB to the UPF1 network element is: target gNB (AN-TT, i.e., AN-TT is located inside the target gNB as a functional module), Switching Node 4, Switching Node 5, UPF1 network element (N3-TT, i.e., N3-TT is located inside the UPF1 network element as a functional module), or, the transmission path of the service flow from the target gNB to the UPF1 network element is: target gNB, AN-TT (AN-TT is deployed separately from the target gNB), Switching Node 4, Switching Node 5, UPF1 network element (N3-TT). It should be noted that... Figure 12A The following explanation uses AN-TT as an example, where a functional module of the target gNB is located inside the target gNB.

[0165] Scenario 2: When the service flow (e.g., the first service flow in the embodiments of this application) is a downlink service flow, the second device is a first user plane network element, that is, the service flow is a downlink service flow that the first user plane network element is to send to the target access network device.

[0166] At this point, after the terminal device switches from the source access network device to the target access network device, the transmission path of the service flow in the mobile communication system is: first user plane network element, target access network device, terminal device. Optionally, at least one switch or router may be included between the target access network device and the first user plane network element on this transmission path.

[0167] For example, such as Figure 12B As shown, 5GS is used as switching node 2, and the service flow is a downlink service flow. The transmission path of the service flow is: Talker, switching node 3, switching node 2, switching node 1, Listener. The transmission path of the service flow in 5GS (i.e., switching node 2) is: UPF1 network element (or NW-TT), target gNB, terminal equipment, DS-TT. The transmission path of the service flow from UPF1 network element to target gNB is UPF1 network element (N3-TT, i.e., N3-TT is a functional module of UPF1 network element located inside UPF1 network element), switching node 5, switching node 4, target gNB (AN-TT, i.e., AN-TT is a functional module of gNB located inside gNB), or, the transmission path of the service flow from UPF network element to gNB is UPF1 network element (N3-TT), switching node 5, switching node 4, AN-TT (AN-TT is located outside gNB), target gNB. Figure 12B This explanation will focus on an example where AN-TT is used as the target gNB, and one of its functional modules is located within the gNB.

[0168] It should be noted that, Figure 12A and Figure 12B The following examples illustrate the scenarios of uplink and downlink traffic transmitted on paths composed of the same network elements. Of course, a path may also transmit only uplink traffic or only downlink traffic, and this application does not make any specific limitations on this.

[0169] Secondly, the following is an exemplary description of the packet delay budget (PDB) used in subsequent embodiments of this application.

[0170] It should be noted that, in the following embodiments, for the scenario where the service flow (e.g., the first service flow in the embodiments of this application) is an uplink service flow (i.e., scenario 1), the packet delay budget (PDB3) for the transmission of the service flow between the terminal device and the first user plane network element represents the upper limit of the delay experienced by the data packet of the service flow from the time it is received by the terminal device until the first user plane network element or NW-TT finishes processing the data packet and sends it to the next hop node.

[0171] When the second device is the target access network device and the third device is the first user plane network element, the converter corresponding to the target access network device (i.e., the aforementioned AN-TT) serves as a functional module within the target access network device. The packet delay budget (PDB1) for service flow transmission between the terminal device and the target access network device represents the upper limit of the delay experienced by the service flow's data packet from its reception at the terminal device to its arrival at the PDCP or SDAP layer of the target access network device. The packet delay budget (PDB2) for service flow transmission between the target access network device and the first user plane network element represents the upper limit of the delay experienced by the service flow's data packet from its issuance at the PDCP or SDAP layer of the target access network device to its processing by the first user plane network element or NW-TT before being sent to the next-hop node. PDB3 is equal to the sum of PDB1 and PDB2, such as... Figure 13A As shown.

[0172] At this point, the packet latency budget for the service flow transmitted between the second and third devices corresponds to the aforementioned PDB2.

[0173] When the second device is the converter corresponding to the target access network device (i.e., the aforementioned AN-TT), and the third device is the first user plane network element, the AN-TT is a device independently deployed outside the target access network device. The packet delay budget (PDB1') for service flow transmission between the terminal device and the converter corresponding to the target access network device (i.e., the aforementioned AN-TT) represents the upper limit of the delay experienced by the service flow's data packet from the time it is received by the terminal device until it reaches the AN-TT. The packet delay budget (PDB2') for service flow transmission between the converter corresponding to the target access network device and the first user plane network element represents the upper limit of the delay experienced by the service flow's data packet from the time it is received by the AN-TT until the first user plane network element or NW-TT processes the data packet and sends it to the next-hop node. PDB3 is equal to the sum of PDB1' and PDB2', as shown below. Figure 13B As shown.

[0174] At this point, the packet latency budget for the service flow transmitted between the second and third devices corresponds to the aforementioned PDB2'.

[0175] It should be noted that, in the following embodiments, for the scenario where the service flow (e.g., the first service flow in the embodiments of this application) is a downlink service flow (i.e., scenario 2), the packet delay budget (PDB6) transmitted between the first user plane network element and the terminal device represents the upper limit of the delay experienced by the data packet of the service flow from the first user plane network element or NW-TT receiving it from the previous hop switching node until it reaches the terminal device (e.g., the application layer of the terminal device).

[0176] When the second device is the first user plane network element and the third device is the target access network device, the converter corresponding to the target access network device (i.e., the aforementioned AN-TT) serves as a functional module within the target access network device. The packet delay budget (PDB4) for service flow transmission between the first user plane network element and the target access network device represents the upper limit of the delay experienced by the service flow's data packets from the first user plane network element or NW-TT receiving them from the previous hop switching node until the data packets are processed by the GPRS Tunnel Protocol for the User Plane (GTP-U) layer of the target access network device. The packet delay budget (PDB5) for service flow transmission between the target access network device and the terminal device represents the upper limit of the delay experienced by the service flow's data packets from the PDCP layer or SDAP layer of the target access network device until they reach the terminal device (e.g., the application layer of the terminal device). PBD6 is equal to the sum of PDB4 and PDB5, such as... Figure 13C As shown.

[0177] At this point, the packet latency budget for the service flow transmitted between the second and third devices corresponds to PDB4 mentioned above.

[0178] When the second device is the first user plane network element and the third device is the converter corresponding to the target access network device (i.e., the aforementioned AN-TT), the AN-TT is a device independently deployed outside the target access network device. The packet delay budget (PDB4') for service flow transmission between the first user plane network element and the converter corresponding to the target access network device (i.e., the aforementioned AN-TT) represents the upper limit of the delay experienced by the service flow's data packet from the first user plane network element or NW-TT receiving it from the previous hop switching node until the AN-TT finishes processing the data packet; the packet delay budget (PDB5') for service flow transmission between the converter corresponding to the target access network device (i.e., the aforementioned AN-TT) and the terminal device represents the upper limit of the delay experienced by the service flow's data packet from the time the AN-TT sends it until it reaches the terminal device (e.g., the application layer of the terminal device). Here, PBD6 is equal to the sum of PDB4' and PDB5', such as... Figure 13D As shown.

[0179] At this point, the packet latency budget for the service flow transmitted between the second and third devices corresponds to the aforementioned PDB4'.

[0180] It is understood that, in the embodiments of this application, for a specific service flow (such as the first service flow mentioned above), if the service flow has both uplink and downlink transmissions, then the packet delay budget (PDB3) transmitted between the terminal device and the first user plane network element is equal to the packet delay budget (PDB6) transmitted between the first user plane network element and the terminal device; the packet delay budget (PDB1) transmitted between the terminal device and the target access network device is equal to the packet delay budget (PDB5) transmitted between the target access network device and the terminal device; the packet delay budget (PDB2) transmitted between the target access network device and the first user plane network element is equal to the packet delay budget (PDB6) transmitted between the first user plane network element and the target access network device. The packet delay budget (PDB4) transmitted between access network devices is equal; the packet delay budget (PDB1') of the service flow transmitted between the terminal device and the converter (i.e., the aforementioned AN-TT) corresponding to the target access network device is equal to the packet delay budget (PDB5') of the service flow transmitted between the converter (i.e., the aforementioned AN-TT) corresponding to the target access network device and the terminal device; the packet delay budget (PDB2') of the service flow transmitted between the converter (i.e., the aforementioned AN-TT) corresponding to the target access network device and the first user plane network element is equal to the packet delay budget (PDB4') of the service flow transmitted between the first user plane network element and the converter (i.e., the aforementioned AN-TT) corresponding to the target access network device. This is stated uniformly here and will not be repeated below. Of course, in the deterministic transmission scenario provided in the embodiments of this application, a certain service flow may only have uplink or only downlink, and the embodiments of this application do not specifically limit this.

[0181] It should be noted that in the embodiments of this application, PDB3 or PDB6 can also be referred to as E2E PDB; PDB1, PDB1', PDB5 or PDB5' can also be referred to as AN PDB; PDB2, PDB2', PDB4 or PDB4' can also be referred to as CN PDB. This is a unified explanation here and will not be repeated below.

[0182] like Figure 14 As shown, this application provides a switching method applied to a first device. The switching method includes the following steps:

[0183] S1401. When the first device determines that the first service flow has switched from a source access network device serving the terminal device to a target access network device serving the terminal device, the interface configuration information for the second device is provided. This interface configuration information is used by the second device to send the first service flow at the service flow transmission time after receiving the first service flow.

[0184] Wherein, if the first service flow is an uplink service flow, the second device is a target access network device or a converter corresponding to the target access network device; or, if the first service flow is a downlink service flow, the second device is a first user plane network element.

[0185] S1402, The first device sends interface configuration information to the second device.

[0186] S1403. After the first device learns from the second device that the interface configuration associated with the interface configuration information has been completed, it notifies the target access network device or the source access network device to execute the handover execution process.

[0187] For steps S1401-S1402 above:

[0188] Optionally, in this embodiment, the first service flow may correspond to a TSC service flow, or simply a TSC flow. For example, the first service flow may be from... Figure 12A or Figure 12B The first service flow can be a TSC stream sent from the Talker to the Listener; or, it can be an aggregated Quality of Services (QoS) stream, that is, multiple TSC streams with the same or similar characteristics are aggregated into a QoS stream; or, the first service flow can also refer to a Protocol Data Unit (PDU) session, that is, a PDU session that transmits TSC streams. Of course, the first service flow may be other than these, and this application embodiment does not specifically limit it.

[0189] Optionally, in this embodiment, the interface configuration information includes first interface configuration information. This first interface configuration information is used by the second device to send the first service flow through a first path at the first service flow transmission time. The first path is the path from the second device to the third device. If the first service flow is an uplink service flow, the third device is a first user plane network element; if the first service flow is a downlink service flow, the third device is a target access network device or a converter corresponding to the target access network device. For example, a schematic diagram of the first path can be shown below. Figure 15 As shown.

[0190] Optionally, in this embodiment, the first interface configuration information includes information about the first service flow transmission time. For example, the information about the first service flow transmission time includes at least one of: the first service flow transmission time, the offset of the first service flow transmission time relative to a reference time, or a first gating scheduling parameter. The first gating scheduling parameter is used by the second device to transmit the first service flow through the first path at the first service flow transmission time. In this embodiment, the reference time refers to the start time of a time domain (e.g., January 1, 1970, 00:00:00), which is explained uniformly here and will not be repeated below.

[0191] The following describes how to obtain the first service stream transmission time and / or the offset of the first service stream transmission time relative to the reference time.

[0192] In one possible implementation, the first device can first determine the transmission time of the first service stream. Further, the first device can determine the offset of the first service stream transmission time relative to a reference time based on the first service stream transmission time. Of course, the first device may also, after determining the first service stream transmission time, not further determine the first service stream transmission time or the offset relative to the reference time; this embodiment does not specifically limit this approach.

[0193] In the second possible implementation, the first device can first determine the offset of the first service stream transmission time relative to the reference time. Further, the first device can determine the first service stream transmission time based on this offset. Of course, the first device can also, after determining the offset of the first service stream transmission time relative to the reference time, not further determine the first service stream transmission time; this embodiment does not specifically limit this approach.

[0194] First, the specific implementation of determining the sending time of the first service flow is provided by the first device.

[0195] In this implementation, the first service flow transmission time is no earlier than the earliest transmission time and no later than the latest transmission time. The first device can determine a time that is no earlier than the earliest transmission time and no later than the latest transmission time as the first service flow transmission time. The first service flow transmission time can be understood as the time when the second device is advised to transmit the first service flow through the first path. The methods for determining the earliest and latest transmission times are given below.

[0196] For example, in a scenario where jitter is not considered, the earliest transmission time is the sum of the arrival time of the first service stream and the processing time of the first service stream on the second device, that is:

[0197] T2=T1+T'. Formula (1)

[0198] Where T2 represents the earliest sending time, T1 represents the arrival time of the first service flow, and T' represents the processing time of the first service flow on the second device.

[0199] In this embodiment, the arrival time of the first service flow can also be understood as the time when the first service flow arrives at the second device. It is understood that the first device can determine at least one of the arrival time of the first service flow or the offset of the arrival time of the first service flow relative to a reference time. In one possible implementation, the first device can first determine the offset of the arrival time of the first service flow relative to the reference time, and then determine the arrival time of the first service flow based on the offset of the arrival time of the first service flow relative to the reference time; alternatively, the first device can directly determine the arrival time of the first service flow, and this embodiment does not specifically limit this. The following examples, using scenarios 1 and 2 above, illustrate the specific process by which the first device determines the information of the arrival time of the first service flow (including the arrival time of the first service flow or the offset of the arrival time of the first service flow relative to the reference time):

[0200] Scenario 1: When the first service flow is an uplink service flow, in one implementation, the first device can obtain the time information of the first service flow arriving at the converter (e.g., DS-TT) on the terminal device side, the dwell time of the first service flow in the terminal device and in the converter on the terminal device side, and the packet delay budget of the first service flow transmitted between the terminal device and the second device.

[0201] For example, the time information of the first service flow arriving at the converter (e.g., DS-TT) on the terminal device side specifically refers to the time information of data packets arriving at the converter on the terminal device side within a specific period of the first service flow. This information can be determined based on the burst arrival time information of the first service flow, the period of the first service flow, and the direction of the first service flow. Specifically, the time information of the first service flow arriving at the converter on the terminal device side can be the time of arrival of the first service flow at the converter on the terminal device side or the offset of the time of arrival of the first service flow at the converter on the terminal device side relative to a reference time.

[0202] The dwell time of the first service flow within the terminal device and within the converter on the terminal device side can be used to determine the dwell time of the first service flow. Figure 2 The length of stay between DS-TT and UE, i.e., UE-DS-TT Residence Time.

[0203] Furthermore, the first device can determine the arrival time of the first service flow or the offset of the arrival time of the first service flow relative to the reference time based on the time information of the first service flow arriving at the converter on the terminal device side, the dwell time of the first service flow within the terminal device and the converter on the terminal device side, and the packet delay budget of the first service flow transmitted between the terminal device and the second device. For example:

[0204] T1 (uplink)=Burst Arrival Time1+(UE-DS-TT Residence time)+AN PDB. Formula (2)

[0205] T1-offset (uplink)=Burst Arrival Time1*+(UE-DS-TT Residence Time)+ANPDB. Formula (3)

[0206] Wherein, T1 (uplink) represents the arrival time of the first service flow in the uplink scenario, T1-offset (uplink) represents the offset of the arrival time of the first service flow in the uplink scenario relative to the reference time, Burst Arrival Time1 represents the time when the first service flow arrives at the converter on the terminal device side, and Burst Arrival Time1* represents the offset of the time when the first service flow arrives at the converter on the terminal device side relative to the reference time. UE-DS-TT Residence Time represents the dwell time of the first service flow within the terminal device and within the converter on the terminal device side, and AN PDB represents the packet delay budget for the first service flow transmitted between the terminal device and the second device, which can be the aforementioned PDB1 or PDB1'. For example, the dwell times of each service flow within the terminal device and within the converter on the terminal device side can be the same or different.

[0207] It is understandable that when the first device is implemented through different devices, the way the first device obtains the above three parameters will also be different. The following examples of methods 1 to 3 illustrate the specific process by which the first device can obtain the above three parameters:

[0208] Method 1: The first device is a session management network element (e.g., Figure 7A or Figure 7B When the SMF network element is used, the first device may obtain the above three parameters in, but is not limited to, the following methods.

[0209] Regarding the timing information of the first service flow arriving at the converter on the terminal device side, the session management network element can determine the timing information of the first service flow arriving at the converter on the terminal device side based on the information obtained from the policy control network element.

[0210] For example, the policy control network element sends parameters such as the burst arrival time of the first service flow, the period of the first service flow, and the direction of the first service flow to the session management network element. The session management network element can determine the arrival time of the first service flow at the converter on the terminal device side based on the burst arrival time of the first service flow, the period of the first service flow, and the direction of the first service flow.

[0211] The burst arrival time information of the first service flow can be the time when the first data packet of the first service flow's data burst arrives at the 5G system ingress port, or the duration or offset of the first data packet of the first service flow's data burst arriving at the 5G system ingress port relative to a reference time. When the direction of the first service flow indicates that the first service flow is an uplink service flow, the 5G system ingress port here refers to the port of the converter (e.g., DS-TT) on the terminal device side. In this case, the burst arrival time information of the first service flow is the time when the first data packet of the first service flow's data burst arrives at the converter on the terminal device side.

[0212] Furthermore, in this embodiment of the application, the period of the first service flow can also be described as the time interval between two adjacent burst start times of the first service flow, and this embodiment of the application does not specifically limit this.

[0213] In one possible implementation, the policy control network element can draw from the TSN application function network element (such as...). Figure 7A The TSN AF network element shown) or a network element with time-delay-sensitive communication and clock synchronization functions (such as...) Figure 7B The TSCTSF network element shown obtains the burst arrival time information of the first service flow, the period of the first service flow, and the direction of the first service flow, etc.

[0214] For example, for Figure 7A In the network architecture shown, the TSN AF network element acts as the control plane of the 5GS switching node. The TSN AF network element determines the above parameters based on the information obtained from the CNC network element and sends them to the policy control network element.

[0215] For example, regarding Figure 7B In the network architecture shown, the TSCTSF network element serves as the control plane of the 5GS switching node. The TSCTSF network element determines the above parameters based on the information obtained from the application function network element and sends them to the policy control network element.

[0216] For example, the policy control network element sends Policy Control and Charging (PCC) rules to the session management network element. The PCC rules include the burst arrival time information of the first service flow, the period of the first service flow, and the direction of the first service flow. For instance, the PCC rules include a TSC assistance container. The TSC assistance container carries the burst arrival time information of the first service flow, the period of the first service flow, and the direction of the first service flow.

[0217] In addition, PCC rules may also include service requirement description parameters. These parameters are obtained by the policy control network element from the TSN application function network element or a network element with time-sensitive communication and clock synchronization functions. These parameters may include at least one of the following: maximum burst size, first service flow priority (StreamRank), first service flow latency requirement, or maximum flow bitrate. The maximum burst size can be the maximum data volume within a specified time period. The first service flow priority defines the priority (Rank) of the first service flow relative to other service flows when transmitted within the TSN domain or within 5GS. The first service flow latency requirement refers to the latency requirement of the first service flow transmission within 5GS (i.e., the transmission latency requirement of the first service flow between the first user plane network element of the terminal equipment). The maximum flow bitrate refers to the highest expected bitrate of the first service flow.

[0218] After receiving the burst arrival time information of the first service flow, the period of the first service flow, and the direction of the first service flow from the policy control network element, the session management network element can determine the time information of the data packets in a specific period of the first service flow arriving at the converter on the terminal device side based on these parameters. That is, the aforementioned time information of the first service flow arriving at the converter on the terminal device side, such as Burst Arrival Time1 or Burst Arrival Time1*.

[0219] Regarding the residence time of the first service flow within the terminal device and within the converter on the terminal device side (UE-DS-TT Residence time), the session management network element can obtain the residence time of the first service flow within the terminal device and within the converter on the terminal device side from the terminal device.

[0220] For example, during the establishment of a Protocol Data Unit (PDU) session, the session management network element can receive a PDU session establishment request message from the terminal device. The PDU session establishment request message carries the dwell time of the first service flow within the terminal device and within the converter on the terminal device side. Optionally, the PDU session establishment request message may also carry the Media Access Control Address (MAC) address of the DS-TT port.

[0221] Based on the packet delay budget for the transmission of the first service flow between the terminal device and the second device, the session management network element can determine the packet delay budget for the transmission of the first service flow between the terminal device and the second device.

[0222] For example, in combination Figure 13A or Figure 13B The session management network element can determine PDB1 or PDB1' based on the 5G QoS Identifier (5QI) in the PCC rules. For example, if the session management network element has already configured PDB2 or PDB2', it can also determine PDB3 based on the 5QI. Then, the session management network element can calculate the difference between PDB3 and PDB2 to obtain PDB1. Alternatively, the session management network element can calculate the difference between PDB3 and PDB2' to obtain PDB1'. For details, please refer to [link / reference]. Figure 13A or Figure 13B The relevant content will not be elaborated further here. Optionally, if the session management network element does not configure PDB2 or PDB2', the session management network element may also determine PDB2 or PDB2'. For example, if the converter corresponding to the target access network device is deployed together with the target access network device, the session management network element may determine PDB2 based on the identifier of the target access network device; or, if the converter corresponding to the target access network device is deployed separately from the target access network device, the session management network element may determine PDB2' based on the identifier of the target access network device and / or the identifier of the converter corresponding to the target access network device. This application embodiment does not specifically limit this. For example, in this application embodiment, the identifier information of the target access network device may include, for example, the identifier of the target access network device, the cell identifier, or the tunnel identifier; the identifier information of the converter corresponding to the target access network device may include, for example, the identifier of the converter corresponding to the target access network device or the port identifier of the converter corresponding to the target access network device. This application embodiment does not specifically limit this.

[0223] Method 2: When the first device is a TSN application function network element (e.g. Figure 8A The TSN AF network element shown) or a network element with time-delay-sensitive communication and clock synchronization functions (such as Figure 8B When the TSCTSF network element is shown, the first device may obtain the above three parameters in, but is not limited to, the following methods.

[0224] Based on the time information of the first service flow arriving at the converter on the terminal device side, the first device can determine the time information of the first service flow arriving at the converter on the terminal device side.

[0225] For example, when the first device is a TSN application function network element, the TSN application function network element also acts as the control plane of the 5GS switching node. Based on information obtained from the CNC network element, it determines parameters such as the burst arrival time of the first service flow, the period of the first service flow, and the direction of the first service flow. Then, the TSN application function network element can determine the time information of the first service flow arriving at the converter on the terminal device side based on these parameters. As another example, when the first device is a network element with delay-sensitive communication and clock synchronization functions, this network element also acts as the control plane of the 5GS switching node. Based on information obtained from the application function network element, it determines parameters such as the burst arrival time of the first service flow, the period of the first service flow, and the direction of the first service flow. Then, the network element with delay-sensitive communication and clock synchronization functions can determine the time information of the first service flow arriving at the converter on the terminal device side based on these parameters. The burst arrival time information of the first business flow and the relevant description of the cycle of the first business flow can be referred to Method 1 above, and will not be repeated here.

[0226] Regarding the dwell time of the first service flow within the terminal device and in the converter on the terminal device side, and the packet delay budget for the first service flow transmitted between the terminal device and the second device, referring to Method 1 above, the session management network element can obtain the dwell time of the first service flow within the terminal device and in the converter on the terminal device side from the terminal device. The session management network element can also determine the packet delay budget (i.e., PDB1 or PDB1') for the first service flow transmitted between the terminal device and the second device. Further, exemplaryly, the first device can directly receive the above information from the session management network element, or receive the above information from the session management network element through other network elements (such as policy control network elements), or the session management network element stores the above information into a data storage network element (e.g., UDM network element) through a data management network element (e.g., UDR network element), and the first device can obtain the above information from the data storage network element.

[0227] Method 3: When the first device is a network management device (e.g., Figure 9 When NM is shown, the first device may obtain the above three parameters in, but is not limited to, the following ways.

[0228] Based on the time information of the first service flow arriving at the converter on the terminal device side, the first device can determine the time information of the first service flow arriving at the converter on the terminal device side.

[0229] For example, when the first device is NM, NM can determine parameters such as the burst arrival time information of the first service flow, the period of the first service flow, and the direction of the first service flow based on the information obtained from the policy control network element. Then, NM can determine the time information of the first service flow arriving at the converter on the terminal device side based on the burst arrival time information of the first service flow, the period of the first service flow, and the direction of the first service flow.

[0230] Regarding the dwell time of the first service flow within the terminal device and in the converter on the terminal device side, and the packet delay budget for the first service flow transmitted between the terminal device and the second device, referring to Method 1 above, it can be seen that the session management network element can obtain the dwell time of the first service flow within the terminal device and in the converter on the terminal device side from the terminal device. The session management network element can also determine the packet delay budget (i.e., PDB1 or PDB1') for the first service flow transmitted between the terminal device and the second device. Further, for example, the first device can directly receive the above information from the session management network element, or receive the above information from the session management network element through other network elements (such as CNC-TN network elements), or the session management network element stores the above information into a data storage network element (e.g., UDM network element) through a data management network element (e.g., UDR network element), and the first device can obtain the above information from the data storage network element.

[0231] Scenario 2: When the first service flow is a downlink service flow, in one implementation, the first device can obtain the time information of the arrival of the first service flow to the first user plane network element, and then the first device can determine the arrival time of the first service flow or the offset of the arrival time of the first service flow relative to the reference time based on the time information of the arrival of the first service flow to the first user plane network element.

[0232] In this embodiment, the time information of the first service flow arriving at the first user plane network element can also be understood as the time information of the first service flow arriving at the converter (e.g., NW-TT) corresponding to the first user plane network element. Optionally, the time information of the first service flow arriving at the first user plane network element may include the time of arrival of the first service flow at the first user plane network element, or the offset of the time of arrival of the first service flow at the first user plane network element relative to a reference time. For example:

[0233] T1 (downward) = Burst Arrival Time2. Formula (4)

[0234] T1-offset (downstream)=Burst Arrival Time2*. Formula (5)

[0235] Where T1 (downlink) represents the arrival time of the first service flow in the downlink scenario, T1-offset (downlink) represents the offset of the arrival time of the first service flow in the downlink scenario relative to the reference time, Burst Arrival Time2 represents the time when the first service flow arrives at the first user plane network element, and Burst Arrival Time2* represents the offset of the time when the first service flow arrives at the first user plane network element relative to the reference time.

[0236] Similarly, when the first device is implemented through different devices, the way the first device obtains the time information of the arrival of the first service flow at the first user plane network element also differs. For example, when the first device is a session management network element (e.g., Figure 7A or Figure 7B When the first device is an SMF network element (such as a policy control network element), the session management network element can determine the time information of the arrival of the first service flow at the first user plane network element based on the information obtained from the policy control network element. Alternatively, for example, when the first device is a TSN application function network element (such as a policy control network element), the session management network element can determine the time information of the arrival of the first service flow at the first user plane network element based on the information obtained from the policy control network element. Figure 8A The TSN AF network element shown) or a network element with time-delay-sensitive communication and clock synchronization functions (such as...) Figure 8B The TSCTSF network element shown) or network management equipment (such as Figure 9 When the NM (as shown) is reached, the first device can determine the time information of the arrival of the first service flow at the first user plane network element. The relevant implementations are similar to those in methods 1 to 3 above, where the first device obtains the time information of the arrival of the first service flow at the converter on the terminal device side. The difference, for example, is that when the direction of the first service flow indicates that it is a downlink service flow, the 5G system ingress port here refers to the port of the converter (e.g., NW-TT) on the first user plane network element side. In this case, the burst arrival time information of the first service flow is the time information of the first data packet of the first service flow's data burst arriving at the converter on the first user plane network element side. Other related descriptions can be found in methods 1 to 3 above, and will not be repeated here.

[0237] The above describes the specific implementation of the first device obtaining the arrival time T1 of the first service flow. The processing time (T') of the first service flow in the second device mentioned in the above formula can be understood as the time required for the second device to decapsulate and process the data packet of the first service flow after it arrives, then encapsulate it again and send it to the output port of the second device. This output port is the port corresponding to the second device sending the first service flow. In other words, the processing time of the first service flow in the second device can be understood as the time elapsed from when the second device receives the data packet of the first service flow until the data packet arrives at the output port of the second device and is ready to be sent. For example, assuming the second device receives the data packet of the first service flow from the upstream node at time t1, and the data packet arrives at the output port of the second device at time t2 after processing, waiting to be sent to the next device, then t2-t1 is the processing time of the first service flow in the second device. Here, time t1 corresponds to the arrival time of the first service flow, and time t2, without considering jitter, corresponds to the earliest sending time.

[0238] In one implementation, when the second device is a first user plane network element, t1 is the time when the data packet of the first service flow arrives at the ingress port of the NW-TT corresponding to the first user plane network element, and t2 is the time when the data packet of the first service flow arrives at the first user plane network element or the egress port of the NW-TT corresponding to the first user plane network element. For example, when the transmission path from the first user plane network element to the target access network device does not include an I-UPF network element, t2 is the time when the data packet of the first service flow arrives at the egress port of the N3-TT corresponding to the first user plane network element. Here, the egress port is the egress port destined for the target access network device or the AN-TT corresponding to the target access network device. Alternatively, for example, when the transmission path from the first user plane network element to the target access network device includes an I-UPF network element, t2 is the time when the data packet of the first service flow arrives at the egress port of the N9-TT corresponding to the first user plane network element. Here, the egress port is the egress port destined for the I-UPF network element.

[0239] In another implementation, when the second device is the target access network device, t1 is the time when the data packet of the first service flow arrives at the target access network device after passing through the air interface, such as the time when it arrives at the PDCP layer or SDAP layer of the target access network device, and t2 is the time when the data packet of the first service flow arrives at the output port after being processed by the target access network device.

[0240] In another implementation, when the second device is the converter corresponding to the target access network device, t1 is the time when the data packet of the first service flow arrives at the converter corresponding to the target access network device after being transmitted over the air interface, and t2 is the time when the data packet of the first service flow arrives at the output port after being processed by the converter corresponding to the target access network device.

[0241] Optionally, in this embodiment of the application, the first device can obtain the processing time information of the second device from the second device, and determine the processing time of the first service flow on the second device based on the processing time information of the second device.

[0242] The processing time information of the second device may include 5QI and the processing time of the service flow corresponding to 5QI in the second device. Further, the first device may determine the processing time of the first service flow in the second device based on the 5QI of the first service flow and the processing time information of the second device.

[0243] Alternatively, the processing time information of the second device includes the range of data packet sizes and the processing time of the service flow that meets the data packet size range in the second device. Further, the first device can determine the range of data packet sizes to which the data packet of the first service flow falls based on the size of the data packet of the first service flow, and determine the processing time of the first service flow in the second device based on the processing time information of the second device.

[0244] Alternatively, the processing time information of the second device includes the processing time of the business flow on the second device, that is, all business flows take the same processing time on the second device, and then the first device determines the processing time of the business flow on the second device in the processing time information of the second device as the processing time of the first business flow on the second device.

[0245] The following examples illustrate how the first device obtains the processing time information of the second device from the second device, using scenarios 1 and 2 as examples:

[0246] Corresponding to scenario 1 above, when the converter corresponding to the target access network device is a functional module within the target access network device, the first device can obtain the processing time information of the second device from the target access network device. In this case, the processing time information of the second device is also referred to as the processing time information of the target access network device.

[0247] When the converter corresponding to the target access network device is a standalone device deployed outside the target access network device, the converter can send the processing time information of the second device to the target access network device. The first device can obtain the processing time information of the second device from the target access network device, or the processing time information of the second device can be configured on the target access network device, or the first device can obtain the processing time information of the second device from the converter corresponding to the target access network device. In this case, the processing time information of the second device is also referred to as the processing time information of the converter corresponding to the target access network device.

[0248] For example, when the first device is a session management network element, before the handover preparation phase, the target access network device can send an NG Setup Request message to the access and mobility management function (AM) network element when establishing a connection with it. This NG Setup Request message carries the processing time information of the second device. Alternatively, the target access network device can send a RAN Configuration Update message to the AM, carrying the processing time information of the second device. Or, during the registration process of a terminal device (e.g., the first terminal device), the target access network device can send the processing time information of the second device to the AM. Furthermore, the AM can send the processing time information of the second device to the session management network element during the handover preparation phase. For example, during the handover preparation phase of the Xn / N2 handover process, the access and mobility management function network element can carry the processing time information of the second device in the PDU session update SM context request message sent to the session management network element; or, during the handover preparation phase of the Xn / N2 handover process, the access and mobility management function network element can send the processing time information of the second device to the session management network element through a newly introduced message. This application embodiment does not specifically limit this.

[0249] Alternatively, for example, when the first device is a session management network element, during the handover preparation process, the target access network device can send the processing time information of the second device to the session management network element through the access and mobility management function network element. For example, in the handover preparation phase of the Xn handover process, the target access network device sends a message to the access and mobility management function network element, such as an N2 path switch request, which carries the processing time information of the second device. Furthermore, the access and mobility management function network element can carry the processing time information of the second device in a message sent to the session management network element, such as a PDU session update SM context request. Or, for example, in the handover preparation phase of the N2 handover process, the target access network device sends a message to the access and mobility management function network element, such as a handover request acknowledgement, which carries the processing time information of the second device. Furthermore, the access and mobility management function network element can carry the processing time information of the second device in a message sent to the session management network element, such as a PDU session update SM context request. Of course, during the handover preparation phase of the Xn / N2 handover process, the target access network device may send the processing time information of the second device to the session management network element through the access and mobility management function network element, and this application embodiment does not specifically limit this.

[0250] Corresponding to scenario 2 above, the first device can obtain the processing time information of the first user plane network element from the first user plane network element.

[0251] For example, when the first device is a session management network element, before the handover preparation phase, the session management network element sends a request message to the first user plane network element. This request message requests the processing time information of the first user plane network element. For example, this request message can be an N4 session establishment message or an N4 session modification request message. The first user plane network element can send a response message to the first device in response to the request message, and the response message carries the processing time information of the first user plane network element. For example, when the request message is an N4 session establishment message, the response message is the same as the response message for the N4 session establishment message; when the request message is an N4 session modification request message, the response message is the same as the response message for the N4 session modification message. Alternatively, the first user plane network element can directly report its processing time information to the session management network element without the session management network element requesting the processing time of the first service flow on the user plane network element.

[0252] Alternatively, for example, when the first device is a session management network element, during the handover preparation process, the session management network element obtains the processing time information of the first user plane network element from the first user plane network element. For instance, during the handover preparation phase of the Xn / N2 handover process, the session management network element sends a request message to the first user plane network element, which requests the processing time information of the first user plane network element. Furthermore, the first user plane network element can send a response message to the session management network element in response to the request message, the response message carrying the processing time information of the first user plane network element. For example, the request message could be an N4 session modification request message, and the response message to the request message could be a response message to the N4 session modification message.

[0253] Furthermore, when the first device is a device other than the session management network element, the session management network element can send the processing time information of the first service flow on the second device to the first device. The first device can directly receive the above information from the session management network element, or receive the above information from the session management network element through other network elements (such as policy control network elements). Alternatively, the session management network element can store the above information into a data storage network element (such as a UDM network element) through a data management network element (e.g., a UDR network element). The first device can obtain the above information from the data storage network element. Alternatively, the processing time information of the second device can also be configured on the first device (for example, the session management network element may configure the processing time information of each user plane network element. After the PDU session is established, the session management network element can obtain the processing time information of the user plane network element based on the obtained identifier of the specific user plane network element (e.g., the identifier of the first user plane network element). This application embodiment does not specifically limit this.

[0254] For example, in a scenario considering jitter, the earliest transmission time is the sum of the arrival time of the first service flow, the processing time of the first service flow on the second device, and the jitter delay associated with the first service flow, i.e.:

[0255] T2 = T1 + Processing time of the first service flow on the second device + Jitter. Formula (6)

[0256] The relevant descriptions of T1, T2, and the processing time of the first business flow on the second device can be found in the above formula (1), and will not be repeated here.

[0257] In this embodiment, Jitter represents the jitter latency associated with the first service flow, which is the transmission latency caused by the existence of a service flow with the same priority as the first service flow. It can be determined based on the size of the largest frame of the service flow with the same priority as the first service flow.

[0258] For example, if a flow does not have any other flows with the same priority, its Jitter value is 0. If a flow has other flows with the same priority, its Jitter value will be affected by the [MaxFrameSize] of all other flows with the same priority. [MaxFrameSize] refers to the time required to send a data packet of size MaxFrameSize in the service flow, or in other words, the duration corresponding to sending the largest data packet in the service flow.

[0259] For example, if streams J and K have the same priority, the maximum time to send a frame of stream J is determined by its [MaxFrameSize] to be 120 μs, and the maximum time to send a frame of stream K is determined by its [MaxFrameSize] to be 80 μs. The jitter of stream K depends on the maximum time to send a frame of stream J. For example, the jitter of stream K is determined by half the maximum time to send a frame of stream J, which is 60 μs. It is understandable that since streams J and K have the same priority, they will enter the same transmission queue. When streams J and K are waiting to be sent simultaneously in the same transmission queue, if stream J is sent first, stream K needs to wait for the maximum duration, which is the maximum time to send a frame of stream J; if stream K is sent first, stream K needs to wait for the minimum duration, which is 0. Therefore, here, based on probability, the jitter of stream K is defined as half the maximum duration (120 μs) of sending a frame of stream J, which is 60 μs. Similarly, the jitter of stream J is 40 μs.

[0260] For example, if streams J, K, and G have the same priority, the maximum duration for sending a frame of stream J is determined by its [MaxFrameSize] as 120 μs, by stream K's [MaxFrameSize] as 80 μs, and by stream G's [MaxFrameSize] as 100 μs. Similarly, the jitter of stream J depends on the maximum duration of a frame sent from stream K and stream G. For instance, the jitter of stream J is determined by the sum of half the maximum duration of a frame sent from stream K and half the maximum duration of a frame sent from stream G, i.e., stream J's jitter is 90 μs. Likewise, the jitter of stream K is 110 μs, and the jitter of stream G is 100 μs.

[0261] Optionally, in this embodiment, when the first device is a session management network element, [MaxFrameSize] can be determined based on the information in the service requirement description parameters included in the PCC rules sent by the policy control network element to the session management network element. For example, the session management network element can determine MaxFrameSize based on the difference between the maximum burst size and the media framing field size in the service requirement description parameters. Then, the session management network element can convert MaxFrameSize into [MaxFrameSize] based on the port capability information of the converter corresponding to the second device. For instance, when the port capability information of the converter corresponding to the second device is the rate at which service flows are sent through the port of the converter corresponding to the second device, [MaxFrameSize] = MaxFrameSize / port capability information of the converter corresponding to the second device. The media framing field can include at least one of the following: preamble, IEEE 802.3 header, priority or VLAN identifier (VID), cyclic redundancy check (CRC), and inter-frame gap. Furthermore, when the first device is a device other than the session management network element, the session management network element can send [MaxFrameSize] to the first device. The first device can directly receive the above information from the session management network element, or receive the above information from the session management network element through other network elements (such as policy control network elements). Alternatively, the session management network element can store the above information into a data storage network element (such as a UDM network element) through a data management network element (e.g., a UDR network element), and the first device can obtain the above information from the data storage network element. This application embodiment does not specifically limit this. Of course, the first device can also determine [MaxFrameSize] itself by using the method determined by the session management network element. This application embodiment does not specifically limit this.

[0262] In summary, in scenarios where jitter is not considered, after the first device obtains the arrival time of the first service flow and the processing time of the first service flow in the second device, it can determine the earliest transmission time by combining formula (1); or, in scenarios where jitter is considered, after the first device obtains the arrival time of the first service flow, the processing time of the first service flow in the second device, and the jitter delay associated with the first service flow, it can determine the earliest transmission time by combining formula (6). Of course, the first device can also omit the process of calculating T1 and directly calculate T2, and this application embodiment does not specifically limit this.

[0263] Furthermore, the first service flow transmission time shall not be later than the latest transmission time. The latest transmission time may be determined using, but is not limited to, the following methods: A, B, or C.

[0264] Method A: Since the first service flow is a periodic service flow, the data packets of the first service flow arriving at the second device need to be sent before the data packets of the next period of the first service flow arrive at the second device. That is, the second device needs to send the data packets of the first service flow within the duration corresponding to the period of the first service flow after the service flow's arrival time. Therefore, the latest time (i.e., the latest sending time) for the second device to send the data packets of the first service flow needs to be earlier than the sum of the arrival time of the first service flow and the period of the first service flow. Furthermore, to ensure that the data packets of the first service flow currently arriving at the second device have been sent before the data packets of the next period of the first service flow arrive, rather than being sent in the process of being sent, based on the above discussion, the latest time (i.e., the latest sending time) for the second device to send the first service flow can be equal to the difference between the sum of the arrival time of the first service flow and the period of the first service flow and the duration corresponding to the largest data packet of the first service flow being sent.

[0265] Optionally, in this embodiment of the application, in a scenario where jitter is not considered, the latest transmission time is determined based on the arrival time of the first service stream, the period of the first service stream, and the size of the largest frame of the first service stream. For example:

[0266] T3A=T1+Interval-[MaxFrameSize]. Formula (7)

[0267] Where T3A represents the latest sending time determined according to method A, and T1 represents the arrival time of the first service flow, which can be obtained by one of the formulas (2) to (5) above. Interval represents the period of the first service flow, and [MaxFrameSize] represents the duration corresponding to the sending of a data packet of size MaxFrameSize by the output port of the second device, that is, the duration corresponding to the sending of the largest data packet of the first service flow. The relevant description can be referred to the above embodiments, and will not be repeated here.

[0268] Of course, the first device can also omit the process of calculating T1 and directly calculate T3A. This application embodiment does not specifically limit this.

[0269] Optionally, in this embodiment of the application, in a scenario considering jitter, the latest transmission time is determined based on the arrival time of the first service stream, the period of the first service stream, the size of the maximum frame of the first service stream, and the jitter latency associated with the first service stream. For example:

[0270] T3A=T1+Interval-[MaxFrameSize]-Jitter. Formula (8)

[0271] The definitions of the relevant parameters in formula (8) can be found in formula (7) above, and will not be repeated here. In addition, Jitter represents the jitter latency associated with the first service flow, and the relevant description can be found in formula (6) above, and will not be repeated here.

[0272] It is understandable that, in scenarios that take jitter into account, the second device must send the data packets of the first service flow earlier than T1+Interval-[MaxFrameSize]-Jitter in order to ensure that when the data packets of the next cycle of the first service flow arrive at the second device, the data packets of the current cycle of the first service flow have already been sent by the second device, rather than being sent. Therefore, Jitter is subtracted here.

[0273] Similarly, the first device can also omit the process of calculating T1, which will not be elaborated here.

[0274] Method B: After the first service flow arrives at the second device, the second device needs to process the first service flow, and is limited by the maximum buffering time of the first service flow on the second device. Therefore, optionally, the latest time (i.e., the latest sending time) for the second device to send the first service flow can be determined based on the arrival time of the first service flow, the processing time of the first service flow on the second device, and the maximum buffering time of the first service flow on the second device. The maximum buffering time of the first service flow on the second device refers to the maximum duration for which the first service flow can be buffered on the second device.

[0275] For example, in a scenario where jitter is not considered,

[0276] T3B = T1 + T' + T*. Formula (9)

[0277] Where T3B represents the latest sending time determined according to method B, T1 represents the arrival time of the first service flow, which can be obtained by one of the formulas (2) to (5) above. T' represents the processing time of the first service flow on the second device, and the relevant description can be found in the formula (1) above, which will not be repeated here. T* represents the maximum buffering time of the first service flow on the second device.

[0278] In one possible implementation, in this embodiment of the application, the maximum buffering time of the first service flow on the second device is related to the maximum buffering time information of the second device. This maximum buffering time information may include, for example, at least one 5QI and the maximum buffering time that the service flow corresponding to each 5QI can be buffered on the second device, a data packet size range and the maximum buffering time of the service flow satisfying the data packet size range on the second device, or the maximum buffering time of the service flow on the second device.

[0279] For example, the first device obtains the maximum caching duration information of the second device, and determines the maximum caching duration that the first service flow can be cached on the second device based on the maximum caching duration information of the second device. For example, the maximum caching duration information includes at least one 5QI and the maximum caching duration that the service flow corresponding to each 5QI can be cached on the second device. Further, the first device can determine the maximum caching duration of the first service flow on the second device based on the 5QI of the first service flow. Alternatively, for example, the maximum caching duration information includes a data packet size range and the maximum caching duration of service flows that satisfy the data packet size range on the second device. Further, the first device can determine the maximum caching duration of the first service flow on the second device by combining the data packet size of the first service flow. Alternatively, for example, the maximum caching duration information includes the maximum caching duration of the service flow on the second device, that is, all service flows have the same maximum caching duration on the second device. Then, the first device determines the maximum caching duration of the service flow on the second device as the maximum caching duration of the first service flow on the second device.

[0280] The method by which the first device obtains the maximum cache duration information of the second device can refer to the method by which the first device obtains the processing time information of the second device in the above embodiments, and will not be repeated here.

[0281] Another possible implementation involves the first device determining the maximum buffer duration of the first service flow on the second device based on the processing time information of the second device, the processing time information of the third device, the packet delay budget for the first service flow transmitted between the second and third devices, and the maximum transmission delay of the first service flow between the second and third devices. For example, the maximum buffer duration T* of the first service flow on the second device = packet delay budget for the first service flow transmitted between the second and third devices - processing time of the first service flow on the third device - processing time of the first service flow on the second device - maximum transmission delay of the first service flow between the second and third devices. The relevant descriptions of the processing time of the first service flow on the second device and the processing time of the first service flow on the third device can be found in the above embodiments and will not be repeated here. The following describes the method for obtaining the packet delay budget for the first service flow transmitted between the second and third devices and the maximum transmission delay of the first service flow between the second and third devices.

[0282] Optionally, in this embodiment, when the first device is a session management network element, the session management network element can determine the packet delay budget for the transmission of the first service flow between the second and third devices based on the 5QI corresponding to the first service flow, determine the processing time of the first service flow in the second device based on the processing time information of the second device, and the session management network element can also determine the maximum transmission delay of the first service flow between the second and third devices. Furthermore, it can calculate the maximum buffering time of the first service flow in the second device based on the above parameters.

[0283] For example, the packet latency budget for the first service flow transmitted between the second and third devices can refer to the relevant descriptions of PDB2 (or PDB2') and PDB4 (or PDB4') in Scenario 1 and Scenario 2 above. For example, taking the first service flow as an uplink service flow, if the latency requirement for the first service flow transmitted between the terminal device and the first user plane network element is 2ms, the session management network element can determine that the packet latency budget (PDB3) transmitted between the terminal device and the first user plane network element is 2ms, and the packet latency budget (PDB2) transmitted between the second and third devices is 1ms.

[0284] Optionally, in this embodiment, the maximum transmission delay of the first service flow between the second and third devices depends on the capabilities of each transmission node between the second and third devices, and is used to indicate the delay required for the first service flow to be transmitted between the second and third devices. The maximum transmission delay of the first service flow between the second and third devices refers to the time elapsed from when the second device sends out the data packet of the first service flow to when the second and third devices, as well as other transmission nodes between them, perform forwarding of the data packet of the first service flow based on gating scheduling parameters under the control of the CNC-TN network element.

[0285] The maximum transmission delay of the first service flow between the second and third devices can be pre-configured on the session management network element. For example, the session management network element can be configured with different maximum transmission delays between different access network devices (or their corresponding converters) and the first user plane network element. Alternatively, it can be configured based on different 5QIs, meaning that for specific access network devices (or their corresponding converters) and the first user plane network element, corresponding maximum transmission delays are pre-configured for different 5QIs. Or, a uniform maximum transmission delay value can be configured, without distinguishing between the 5QIs corresponding to different services. This application embodiment does not specifically limit this.

[0286] Based on the above method, the first device can obtain the maximum buffer duration of the first service flow on the second device, and then calculate T3B by combining formula (9).

[0287] Optionally, in this embodiment of the application, the first device may omit the process of calculating T1 and directly calculate T3B. This embodiment of the application does not specifically limit this.

[0288] For example, in a scenario that takes jitter into account,

[0289] T3B = T1 + T' + T* - Jitter. Formula (10)

[0290] Understandably, in scenarios that take jitter into account, the second device needs to send the data packets of the first service flow earlier than T1+T'+T*-Jitter in order to ensure that the data packets of the first service flow are buffered on the second device for no more than the maximum buffering time.

[0291] Similarly, the first device can also omit the process of calculating T1, which will not be elaborated here.

[0292] Method C: Based on Method A and Method B, select the smaller value between the latest transmission times determined by Method A and Method B as the latest transmission time. For example, take the smaller value between T3A and T3B.

[0293] It should be noted that the above three methods for determining the latest transmission time are only examples. The first device can also obtain the latest transmission time through other methods, and this application embodiment does not specifically limit this.

[0294] Optionally, in this embodiment, after determining the earliest and latest transmission times in the above manner, the first device can determine a time no earlier than the earliest transmission time and no later than the latest transmission time as the first service flow transmission time. Further, the first device can determine the offset of the first service flow transmission time relative to the reference time based on the first service flow transmission time; this embodiment does not specifically limit this.

[0295] Next, the first device will determine the specific implementation of the offset of the first service flow transmission time relative to the reference time.

[0296] In this implementation, the first device can obtain an offset selection value and use it as the offset of the first service flow transmission time relative to the reference time. Alternatively, the difference between the offset selection value and the jitter delay associated with the first service flow can be used as the offset of the first service flow transmission time relative to the reference time. The method for obtaining the offset selection value is given below.

[0297] In this embodiment, the offset selection value is not less than the minimum offset and not greater than the maximum offset. The minimum offset is the smallest offset of the time the second device sends the first service stream relative to the reference time, which is equal to the offset of the earliest sending time relative to the reference time in the first implementation described above. The maximum offset is the largest offset of the time the second device sends the first service stream relative to the reference time, which is equal to the offset of the latest sending time relative to the reference time in the first implementation described above. The methods for determining the minimum and maximum offsets are given below.

[0298] For example, the minimum offset can be the Earliest TransmitOffset in TSpecTimeAware, which defines the earliest time offset relative to the base time at which the second device can start sending data packets within the period (Interval) of the first service flow.

[0299] For the minimum offset, the first device can determine the minimum offset based on the arrival time information of the first service flow and the processing time of the first service flow in the second device. For example, the minimum offset is the sum of the offset of the arrival time of the first service flow relative to the reference time and the processing time of the first service flow in the second device, or the minimum offset is the sum of the offset of the arrival time of the first service flow relative to the reference time, the processing time of the first service flow in the second device, and the jitter delay associated with the first service flow.

[0300] For example, in a scenario where jitter is not considered,

[0301] EarliestTransmitOffset=(T1-offset)+T'. Formula (11)

[0302] For example, in a scenario that takes jitter into account,

[0303] EarliestTransmitOffset=(T1-offset)+T'+Jitter. Formula (12)

[0304] Where EarliestTransmitOffset represents the minimum offset, T1-offset represents the offset of the arrival time of the first service flow relative to the reference time, which can be T1-offset (uplink) obtained by formula (3) above or T1-offset (downlink) obtained by formula (5) above, T' represents the processing time of the first service flow on the second device, and Jitter represents the jitter latency associated with the first service flow. The relevant description can be referred to the description in the first implementation method above, and will not be repeated here.

[0305] Similarly, in the above formulas (11) and (12), the first device can also omit the process of calculating T1-offset, which will not be elaborated here.

[0306] For example, the maximum offset can be the latest transmission offset in TSpecTimeAware, which defines the latest time offset between the time when the second device can start sending data packets and the base time within the period (Interval) of the first service flow.

[0307] In this embodiment of the application, since the maximum offset corresponds to the latest transmission time in the first implementation method described above, the method by which the first device determines the maximum offset can refer to the method for determining the latest transmission time described above, and is briefly explained as follows.

[0308] Method A*: For example, in a scenario where jitter is not considered,

[0309] LatestTransmitOffset=(T1-offset)+Interval-[MaxFrameSize]. Formula (13)

[0310] For example, in a scenario that takes jitter into account,

[0311] LatestTransmitOffset=(T1-offset)+Interval-[MaxFrameSize]-Jitter.

[0312] Formula (14)

[0313] Wherein, LatestTransmitOffset represents the maximum offset, T1-offset represents the offset of the arrival time of the first service flow relative to the base time, which can be T1-offset (uplink) obtained by formula (3) above or T1-offset (downlink) obtained by formula (5) above, Interval represents the period of the first service flow, [MaxFrameSize] represents the duration corresponding to the transmission of a data packet of size MaxFrameSize by the output port of the second device, that is, the duration corresponding to the transmission of the maximum data packet of the first service flow, and Jitter represents the jitter latency associated with the first service flow. The relevant description can be referred to the description in the first implementation method above, and will not be repeated here.

[0314] Method B*: For example, in a scenario where jitter is not considered,

[0315] LatestTransmitOffset=(T1-offset)+T'+T*. Formula (15)

[0316] For example, in a scenario that takes jitter into account,

[0317] LatestTransmitOffset=(T1-offset)+T'+T*-Jitter. Formula (16)

[0318] Wherein, LatestTransmitOffset represents the maximum offset, T1-offset represents the offset of the arrival time of the first service flow relative to the base time, which can be obtained by formula (3) above (uplink) or by formula (5) above (downlink), T' represents the processing time of the first service flow on the second device, Jitter represents the jitter latency associated with the first service flow, and T* represents the maximum buffering time of the first service flow on the second device. The relevant descriptions can be found in the description of the first implementation method above, and will not be repeated here.

[0319] Method C*: Based on Method A* and Method B*, select the smaller value as the maximum offset according to the maximum offset determined by Method A* and Method B* respectively.

[0320] Optionally, in this embodiment of the application, after determining the minimum offset and the maximum offset in the above manner, the first device may obtain the offset selection value in, but is not limited to, the following manner.

[0321] In one possible design, the first device sends a minimum offset and a maximum offset to the fourth device. The fourth device can determine an offset selection value based on the minimum and maximum offsets and then send the offset selection value to the first device.

[0322] In addition, the above method can also be applied to the first implementation described above. For example, the first device sends the offset of the earliest transmission time relative to the reference time and the offset of the latest transmission time relative to the reference time to the fourth device. The fourth device can determine the offset selection value based on the offset of the earliest transmission time relative to the reference time and the offset of the latest transmission time relative to the reference time, and send the offset selection value to the first device. The offset selection value corresponding to the first service flow is greater than or equal to the minimum offset corresponding to the first service flow, and less than or equal to the maximum offset corresponding to the first service flow.

[0323] It is understandable that the earliest sending time offset from the base time is equal to the minimum offset, and the latest sending time offset from the base time is equal to the maximum offset. The following explanation will only use the maximum and minimum offsets as examples.

[0324] In one possible implementation, in addition to the minimum and maximum offsets corresponding to the first service flow, the fourth device can also obtain the minimum and maximum offsets corresponding to the second service flow, wherein the second service flow arrives at the second device at the same time as the first service flow, or the difference between the time when the second service flow arrives at the second device and the time when the first service flow arrives at the second device is less than or equal to a threshold.

[0325] Furthermore, the fourth device can determine the offset selection value corresponding to the first service flow and the offset selection value corresponding to the second service flow based on the minimum and maximum offsets corresponding to the first service flow and the minimum and maximum offsets corresponding to the second service flow.

[0326] Specifically, the offset selection value corresponding to the first service flow is greater than or equal to the minimum offset corresponding to the first service flow and less than or equal to the maximum offset corresponding to the first service flow. The offset selection value corresponding to the second service flow is greater than or equal to the minimum offset corresponding to the second service flow and less than or equal to the maximum offset corresponding to the second service flow. This ensures the deterministic latency requirements of both the first and second service flows. Furthermore, the difference between the offset selection values ​​corresponding to the first and second service flows is greater than or equal to the [MaxFrameSize] of the first service flow (when the fourth device determines that the offset selection value corresponding to the first service flow is less than the offset selection value corresponding to the second service flow) or the [MaxFrameSize] of the second service flow (when the fourth device determines that the offset selection value corresponding to the first service flow is not less than the offset selection value corresponding to the second service flow), thus preventing congestion in the first and second service flows.

[0327] Optionally, the first device can also send the priority of the first service flow to the fourth device. The fourth device can determine the offset selection value based on the maximum and minimum offsets corresponding to the first service flow, as well as the priority of the first service flow. For example, a smaller offset selection value can be set for a higher priority service flow. The smaller the offset selection value, the shorter the buffering time of the service flow's data packets on the second device; the larger the offset selection value, the longer the buffering time of the service flow's data packets on the second device. By setting a relatively small offset selection value for higher priority service flows, it can be ensured that the data packets of that service flow are sent first, thereby ensuring lower transmission latency.

[0328] Alternatively, the first device may send the priority of the second service flow to the fourth device, and the fourth device may comprehensively consider the priorities of each service flow to determine the offset selection value for each service flow.

[0329] Optionally, the first device may also send the maximum latency requirement for the transmission of the first service flow between the second and third devices to the fourth device. The fourth device may determine an offset selection value by combining the maximum latency requirement for the transmission of the first service flow between the second and third devices, the minimum offset, and the maximum offset, and send the offset selection value to the first device. The maximum latency requirement for the transmission of the first service flow between the second and third devices refers to the maximum allowable value of the time elapsed from when the first service flow is sent by the second device to when it is received by the third device, or the maximum allowable value of the time elapsed from when the first service flow is sent by the third device to when it is received by the second device.

[0330] For example, if the packet delay budget for the first service flow transmitted between the second and third devices does not include the processing time of the first service flow at the target access network device or the converter corresponding to the target access network device, the first device can determine the maximum delay requirement for the first service flow transmitted between the second and third devices based on the packet delay budget for the first service flow transmitted between the second and third devices and the processing time of the first service flow at the first user plane network element. An example:

[0331] Maximum latency requirement for the first service flow transmission between the second and third devices = Packet latency budget for the first service flow transmission between the second and third devices - Processing time of the first service flow in the first user plane network element. Formula (17)

[0332] Alternatively, for example, if the packet latency budget for the first service flow transmitted between the second and third devices includes the processing time of the first service flow at the target access network device or the converter corresponding to the target access network device, the first device can determine the maximum latency requirement for the first service flow transmitted between the second and third devices based on the packet latency budget for the first service flow transmitted between the second and third devices, the processing time of the first service flow at the second device, and the processing time of the first service flow at the third device. An example:

[0333] Maximum latency requirement for the first service flow transmission between the second and third devices = Budgeted packet latency for the first service flow transmission between the second and third devices - Processing time of the first service flow on the second device - Processing time of the first service flow on the third device. Formula (18)

[0334] The packet delay budget for the transmission of the first service flow between the second and third devices, the processing time of the first service flow on the second device, and the processing time of the first service flow on the third device can be referred to the above embodiments and will not be repeated here.

[0335] Understandably, the smaller the maximum latency requirement, the higher the latency requirement of the business flow, and the more quickly the business flow needs to be sent out. Conversely, the larger the maximum latency requirement, the lower the latency requirement of the business flow, and the less urgent it is to send out the business flow.

[0336] For example, the fourth device may determine the offset selection value in, but is not limited to, the following ways:

[0337] In one implementation, the fourth device can determine the offset selection value based on the maximum and minimum offsets corresponding to the first service flow, and the maximum latency requirements corresponding to the other service flows mentioned above. For example, for service flows with smaller maximum latency requirements transmitted between the second and third devices, a smaller offset selection value is set. The smaller the offset selection value, the shorter the buffering time of the service flow's data packets on the second device; the larger the offset selection value, the longer the buffering time of the service flow's data packets on the second device. By setting relatively smaller offset selection values ​​for service flows with more stringent latency requirements, it can be ensured that the data packets of that service flow are sent first, thereby ensuring lower transmission latency.

[0338] Optionally, the first device can also send the maximum latency requirements for multiple service flows transmitted between the second and third devices to the fourth device. The fourth device can comprehensively consider the maximum latency requirements of each service flow between the second and third devices to determine the offset selection value for each service flow. For example, if the maximum latency requirement of a service flow between the second and third devices is small, the fourth device can determine a value closer to the minimum offset corresponding to that service flow as the offset selection value for that service flow; if the maximum latency requirement of a service flow between the second and third devices is large, the fourth device can determine a value closer to the maximum offset as the offset selection value for that service flow.

[0339] It should be noted that this application does not limit the specific method by which the fourth device determines the offset selection value. The above content is only an example and is not intended to limit this application. Moreover, the above methods can be combined.

[0340] In another possible design, the first device can determine the offset selection value itself based on the minimum offset and the maximum offset, which is not specifically limited in this embodiment of the application.

[0341] Understandably, in some special cases, the offset selection value can also be equal to the minimum offset, or in other words, the service flow sending time can be equal to the earliest sending time. For example, if at a certain moment no other service flow arrives at the second device besides the first service flow, the second device can send the first service flow based on the minimum offset. Another example is that three service flows arrive at the second device simultaneously: service flow a, service flow b, and service flow c. For service flow a, the offset selection value can be equal to the minimum offset of service flow a; that is, after service flow a arrives at the second device and is processed by the second device, the second device immediately sends service flow a to the third device. For service flow b, the offset selection value can be greater than the minimum offset of service flow b and less than or equal to the maximum offset of service flow b (the offset selection value for service flow b is denoted as the first value). Then, after service flow b arrives at the second device and is processed by the second device, the second device needs to wait for a period of time corresponding to the difference between the first value and the minimum offset of service flow b before sending service flow b to the third device. For service flow c, the offset selection value corresponding to service flow c can be greater than the minimum offset corresponding to service flow c and less than or equal to the maximum offset corresponding to service flow c (the offset selection value corresponding to service flow c is denoted as the second value), and the second value is greater than the first value. After service flow c arrives at the second device and is processed by the second device, the second device needs to wait for a period of time corresponding to the difference between the second value and the minimum offset corresponding to service flow c before sending service flow c to the third device. Therefore, by configuring different service flow sending times for each service flow using the above method, the data packets of the three service flows will not experience congestion, and the latency requirements of the three service flows can be met respectively.

[0342] Optionally, the difference between the first value and the minimum offset is the [MaxFrameSize] corresponding to service flow a, and the difference between the second value and the first value is the [MaxFrameSize] corresponding to service flow b. This setting allows service flow b to be sent after service flow a has been sent, and service flow c to be sent after service flow b has been sent. This better avoids congestion during the sending of service flows a, b, and c, while fully utilizing network resources and improving overall network performance.

[0343] In summary, using the above method, the first device can obtain an offset selection value, which can be used as the offset of the first service stream transmission time relative to the reference time. Alternatively, the difference between the offset selection value and the jitter delay associated with the first service stream can be used as the offset of the first service stream transmission time relative to the reference time. Furthermore, the first device can determine the first service stream transmission time based on the offset of the first service stream transmission time relative to the reference time; this embodiment of the application does not specifically limit this.

[0344] The following is a description of the first gating scheduling parameters.

[0345] For example, the first device can determine the first gating scheduling parameters based on the first service flow transmission time / the offset of the first service flow transmission time relative to the base time, the period of the first service flow, and the maximum burst size of the first service flow. The first gating scheduling parameters may include the management value of the port gating period (AdminCycleTime), the management value of the base time (AdminBaseTime), and the management value of the port gating list (AdminControlList). Further, the second device determines the third gating scheduling parameters based on the first gating scheduling parameters. The third gating scheduling parameters may include the operation value of the port gating period (OperCycleTime), the operation value of the base time (OperBaseTime), the start time of the gating period (CycleStartTime), and the operation value of the gating list running on the port (OperControlList).

[0346] The relationship between the first gating scheduling parameter and the third gating scheduling parameter is described below:

[0347] AdminCycleTime: Used to configure the gating cycle for each port. The second device uses this parameter to set the operating value (OperCycleTime) for the port gating cycle. AdminCycleTime and OperaCycleTime can be the same or different.

[0348] AdminBaseTime: Used to configure the start time of the gating cycle for each port. Typically, AdminBaseTime represents the duration relative to the start time of a time domain (e.g., January 1, 1970, 00:00:00). The second device uses this parameter to set the operating value (OperBaseTime) of the base time. AdminBaseTime and OperaBaseTime can be the same or different. Furthermore, the second device can determine the start time of the gating cycle (CycleStartTime) based on OperaBaseTime and OperaCycleTime, where CycleStartTime = OperaBaseTime + (N-1) * OperaCycleTime, and N represents the Nth cycle and is a positive integer.

[0349] AdminControlList: This parameter configures the gating actions for each port's transmission queues, including the gating state (gateState) and the time interval (TimeInterval). gateState represents the gating state (on or off) of each transmission queue on the port. When the gating state is on, the switch can transmit service flows; when it is off, the switch cannot transmit service flows. TimeInterval specifies the duration of this gating state. The switch uses this parameter to set the operation value of the port's operating gating list (OperControlList). AdminControlList and OperatorControlList can be the same or different.

[0350] Figure 16 A schematic diagram of an AdminControlList or OperaControlList is shown. Figure 16 The gate control list on the right can represent either AdminControlList or OperaControlList. The following description uses AdminControlList as an example. Figure 16 As shown, at time T00 (AdminBaseTime), the gating states of the eight transmission queues (7 to 0) are as follows: oCooCooo. Here, C indicates a closed gating state, meaning data packets in the corresponding queue cannot be sent; o indicates an open gating state, meaning data packets in the corresponding queue can be sent. The duration of this state is T01 minus the duration of T00. That is, at time T01, the gating state changes, and at time T01, the gating states of the eight transmission queues (7 to 0) are as follows: CoCooCCo. For example, at time T05, the gating state of the transmission queue corresponding to sequence number 7 is C, meaning the second device does not transmit data packets from the transmission queue corresponding to sequence number 7 at time T05. At time T05, the gating state of the transmission queue corresponding to sequence number 6 is o, meaning the second device can transmit data packets from the transmission queue corresponding to sequence number 6 at time T05.

[0351] Understandably, the second device can be used to transmit multiple service flows, which may arrive simultaneously or at different times. The priorities of each service flow can be the same or different. When multiple service flows have different priorities, the second device can place them into different transmission queues based on their priorities. Service flows with the same priority are placed into the same transmission queue. For each transmission queue, the first device can determine the corresponding first gating scheduling parameter based on the service flows to be transmitted in that queue, and the second device can determine the corresponding third gating scheduling parameter based on the first gating scheduling parameter. In other words, the gating scheduling parameter corresponding to a transmission queue is used to schedule one or more service flows of the same priority transmitted through that transmission queue.

[0352] Specifically, the method for configuring the first gating scheduling parameters for the first device and the third gating scheduling parameters for the second device can be seen in the following example:

[0353] Example 1: When multiple service flows with the same priority arrive at the second device simultaneously, the second device places these multiple service flows into a transmission queue. In this scenario, the first device can determine AdminBaseTime based on the minimum value among the offset selection values ​​corresponding to the multiple service flows, determine AdminCycleTime based on the least common multiple of the periods corresponding to the multiple service flows, and determine the duration for which the gate state is open based on [MaxFrameSize] corresponding to each service flow.

[0354] For example, assume that periodic traffic flows J and K have the same priority. Both periodic traffic flows J and K have a period of 500μs. The [MaxFrameSize] (representing the duration corresponding to the largest data packet of periodic traffic flow J) for periodic traffic flow J is 120μs in time; the [MaxFrameSize] (representing the duration corresponding to the largest data packet of periodic traffic flow K) for periodic traffic flow K is 80μs in time; the offset selection values ​​(TimeAwareOffset) for periodic traffic flows J and K are respectively:

[0355] For a periodic business flow J, TimeAwareOffset = 1600,000,000,000,320μs;

[0356] For a periodic business flow K, TimeAwareOffset = 1600,000,000,000,440μs;

[0357] Then the first device can determine the first gate scheduling parameters corresponding to periodic service flow J and periodic service flow K: AdminBaseTime is 1600,000,000,000,320μs; AdminCycleTime is 500μs; AdminControlList, where GateState = Open, TimeInterval = 200μs; GateState = Closed, TimeInterval = 300μs.

[0358] Subsequently, the first device sends the aforementioned determined first gating scheduling parameters to the second device, and the second device determines the third gating scheduling parameters based on the first gating scheduling parameters. Among these, the OperaBaseTime, OperaCycleTime, and OperaControlList of periodic service flows J and K are, for example:

[0359] OperCycleTime=AdminCycleTime=500μs;

[0360] OperBaseTime=AdminBaseTime=1600,000,000,000,320μs;

[0361] CycleStartTime = OperaBaseTime + (N-1) * OperaCycleTime, where N represents the Nth cycle and N is a positive integer;

[0362] AdminControlList is the same as OperaControlList.

[0363] Example 2: When multiple service flows with different priorities arrive at different times, after the first device puts the multiple service flows into different transmission queues, it can determine AdminBaseTime based on the minimum value among the offset selection values ​​corresponding to the multiple service flows, and determine AdminCycleTime based on the least common multiple of the cycles corresponding to the multiple service flows.

[0364] For example, suppose periodic traffic flows J and K have different priorities, and periodic traffic flow J has a higher priority than periodic traffic flow K, meaning that periodic traffic flow J has priority in transmission compared to periodic traffic flow K. Furthermore, the period of periodic traffic flow J is 400μs; the period of periodic traffic flow K is 800μs; the [MaxFrameSize] (representing the duration corresponding to the largest data packet of periodic traffic flow J) for periodic traffic flow J is 120μs in time; the [MaxFrameSize] (representing the duration corresponding to the largest data packet of periodic traffic flow K) for periodic traffic flow K is 80μs in time; and the offset selection values ​​(TimeAwareOffset) for periodic traffic flows J and K are respectively:

[0365] For a periodic business flow J, TimeAwareOffset = 1600,000,000,000,260μs;

[0366] For a periodic business flow K, TimeAwareOffset = 1600,000,000,000,380μs.

[0367] It should be noted that the difference between the TimeAwareOffset of periodic service flow K and the TimeAwareOffset of periodic service flow J is equal to the [MaxFrameSize] of flow K. This allows periodic service flows K and J to be sent out at different times, preventing congestion. Of course, this application is not limited to this; the difference between the TimeAwareOffset of periodic service flow K and the TimeAwareOffset of periodic service flow J can also be greater than the [MaxFrameSize] of flow K.

[0368] The first device can determine AdminBaseTime as 1600,000,000,000,260μs based on the TimeAwareOffset of the different streams (for example, taking the minimum value among the TimeAwareOffsets of the different streams). The first device also determines AdminCycleTime as 800μs (i.e., the least common multiple of the Intervals corresponding to periodic service streams J and K), and configures AdminControlList according to AdminCycleTime, the Intervals corresponding to periodic service streams J and K, and the [MaxFrameSize] corresponding to periodic service streams J and K.

[0369] Subsequently, the first device sends the aforementioned determined first gating scheduling parameters to the second device, and the second device determines the third gating scheduling parameters based on the first gating scheduling parameters. Among these, the OperaBaseTime, OperaCycleTime, and OperaControlList of periodic service flows J and K are, for example:

[0370] OperCycleTime=AdminCycleTime=800μs;

[0371] OperBaseTime=AdminBaseTime=1600,000,000,000,260μs;

[0372] CycleStartTime = OperaBaseTime + (N-1) * OperaCycleTime, where N represents the Nth cycle and N is a positive integer;

[0373] AdminControlList is the same as OperaControlList.

[0374] Optionally, in this embodiment of the application, the first interface configuration information may include the offset of the first service flow transmission time relative to the reference time and the first gating scheduling parameters, that is, the first device simultaneously sends the offset of the first service flow transmission time relative to the reference time and the first gating scheduling parameters to the second device.

[0375] Alternatively, in this embodiment, the first interface configuration information includes first gating scheduling parameters but does not include the offset of the first service flow transmission time relative to the base time. That is, the first device may not directly configure the transmission times of multiple service flows respectively, but instead implicitly indicate a transmission time for one service flow through AdminBaseTime. This transmission time can be the transmission time of any one of the multiple service flows, with other service flows being sent randomly after this transmission time; that is, the transmission order of each service flow is not specified. By reserving a sufficiently long duration for the gate to be open, it is ensured that multiple service flows can be sent from the second device while the gate is open.

[0376] The following explanations will be based on Examples 1 and 2 above.

[0377] In this embodiment of the application, the first interface configuration information includes the offset of the first service flow transmission time relative to the base time and the first gating scheduling parameters. Referring to Example 1 above, see... Figure 17As shown, the duration corresponding to the largest data packet of periodic service flow J is 120μs, and the duration corresponding to the largest data packet of periodic service flow K is 80μs. The difference between the TimeAwareOffset corresponding to periodic service flow J and the TimeAwareOffset corresponding to periodic service flow K can be the duration corresponding to the largest data packet of periodic service flow J (i.e., 120μs). The duration for which the gate remains open in each cycle is 200μs. That is, the duration for which the gate remains open in each cycle is the sum of the duration corresponding to the largest data packet of periodic service flow J and the duration corresponding to the largest data packet of periodic service flow K. After 200μs of the gate state switching to open, the gate state switches to closed. In addition, the period of periodic service flow J is the same as the period of periodic service flow K, which is 500μs. That is, after 300μs of the gate state switching to closed, the next cycle begins, and the gate state switches to open again. By using the above method and configuring the gating scheduling parameters corresponding to periodic service flow J and periodic service flow K, it is possible to avoid congestion of service flows with the same priority that arrive at the second device at the same time, while ensuring the deterministic latency requirements of the service flows.

[0378] Assuming that in this embodiment, the first interface configuration information includes the first gating scheduling parameters but does not include the offset of the first service flow sending time relative to the base time, see Example 1 above. Figure 18 As shown, the duration corresponding to the largest data packet sent in periodic service flow J is 120μs, and the duration corresponding to the largest data packet sent in periodic service flow K is 80μs. Therefore, the time the gate remains open in each cycle is 200μs. That is, after 200μs of the gate being open, the gate is closed. Furthermore, the period of periodic service flow J is the same as that of periodic service flow K, which is 500μs. This means that after 300μs of the gate being closed, the next cycle begins, and the gate is open again.

[0379] like Figure 19As shown, since periodic service streams J and K have the same priority, they will be transmitted in the same transmission queue. For ease of description, it is assumed that the output port of the second device only supports two transmission queues. It is assumed that periodic service streams J and K are transmitted in transmission queue 1, and another periodic service stream M is transmitted in transmission queue 0. To facilitate the explanation of the gating operation process of the second device for periodic service streams J and K, it is assumed that periodic service stream M does not have a low transmission latency requirement and is transmitted when the transmission node has idle resources. Taking the time corresponding to AdminBaseTime as T00 as an example, at this time, the gating state of transmission queue 1 is open, and the second device can send periodic service streams J and K. If periodic service streams J and K arrive at the second device simultaneously, it is possible that periodic service stream J is sent first, followed by periodic service stream K, or vice versa. The gate is open for 200 μs. The second device completes the transmission of periodic service streams J and K. At time T01, the gating state of each transmission queue changes; transmission queue 1 is now closed, and the gate is open for 300 μs. The second device stops transmitting periodic service streams J and K and begins transmitting periodic service stream M. At time T02, the gating operation lasts for one cycle, or OperaCycleTime (500 μs). The gating operation at time T00 is repeated starting at time T02.

[0380] It should be noted that in the above example, whenever the gating state corresponding to periodic service streams J and K is open, although the first device does not indicate the order in which periodic service streams J and K are sent—that is, the order in which periodic service streams J and K are sent is uncertain (for example, the second device may send periodic service stream J first or periodic service stream K first)—it still will not cause micro-bursts or micro-congestion in the transmission nodes between the second device and the third device. This is because the first device can configure the second device to reserve a sufficiently long transmission time for periodic service streams J and K; that is, the duration of the open gating state is long enough. For the second device, regardless of whether periodic service stream J or K is sent first, it can complete the transmission of periodic service streams J and K within the duration of the open gating state. Similarly, for the transmission node between the second and third devices, regardless of whether the periodic service stream J or the periodic service stream K is received first, the fourth device can configure the transmission node to reserve a fixed and sufficiently long duration for the gating state to be open for transmitting these two periodic service streams. This allows the periodic service streams J and K to be transmitted within the duration the gating state is open. Using the solution provided in this application, it can be ensured that the second device and the transmission node between the second and third devices reserve sufficient resources for transmitting periodic service streams J and K, thereby achieving determinism in the transmission time of periodic service stream J and the transmission time of periodic service stream K.

[0381] In other words, in the example above, the gating scheduling parameters implicitly indicate the transmission time of service flows with the same priority. The transmission time of the service flows passed through the gating scheduling parameters can be used to send multiple service flows in the transmission queue in sequence. At the same time, the gating state is open for a long enough time to ensure that multiple service flows are transmitted completely, thereby achieving deterministic transmission and improving the overall network performance.

[0382] Assuming that in this embodiment, the first interface configuration information includes the first gating scheduling parameters but does not include the offset of the first service flow sending time relative to the base time, see Example 2 above. Figure 20As shown, the queue containing periodic service flow J has a gate state that remains open for 120μs within each cycle, since the duration corresponding to the maximum data packet transmission of periodic service flow J is 120μs. This means that after the gate state of the queue containing periodic service flow J switches to open for 120μs, the gate state of the queue containing periodic service flow J switches to closed. Furthermore, the cycle of periodic service flow J is 400μs, meaning that after the gate state of the queue containing periodic service flow J switches to closed for 280μs, the next cycle begins, and the gate state of the queue containing periodic service flow J switches to open again. Therefore, the AdminControlList of periodic business flow J includes: GateState = Open, TimeInterval = 120μs (indicating that the gate state switches to open for 120μs); GateState = Closed, TimeInterval = 280μs (indicating that the gate state switches to open for 280μs); GateState = Open, TimeInterval = 120μs; GateState = Closed, TimeInterval = 280μs.

[0383] For the queue containing periodic business flow K, the gate state is initially closed, and only switches to open when the gate state of periodic business flow J is closed. The rest of the principle is similar to that of periodic business flow J. Therefore, the AdminControlList of periodic business flow K includes: GateState = Closed, TimeInterval = 120μs; GateState = Open, TimeInterval = 80μs; ​​GateState = Closed, TimeInterval = 720μs; GateState = Open, TimeInterval = 80μs; ​​GateState = Closed, TimeInterval = 720μs.

[0384] Understandably, the first device determines AdminBaseTime, AdminCycleTime, the AdminControlList of periodic service flow J, and the AdminControlList of periodic service flow K. It also determines the service flow transmission time of periodic service flow J, i.e., AdminBaseTime, and the service flow transmission time of periodic service flow K. That is, it determines the time when the gate state of periodic service flow K is open based on AdminBaseTime, the AdminControlList of periodic service flow J, and the AdminControlList of periodic service flow K, and uses this as the service flow transmission time of periodic service flow K.

[0385] Furthermore, after the second device determines the third gating scheduling parameter based on the first gating scheduling parameter, the queues containing periodic service flow J and periodic service flow K, corresponding to the time offset of OperaBaseTime, are operated according to their respective OperaControlLists.

[0386] For example, for a periodic traffic flow J, at a time offset of 1600,000,000,000,260μs, the gate state of the transmission queue for periodic traffic flow J is open. The gate state remains open for 120μs. At a time offset of 1600,000,000,000,380μs, the gate state of the transmission queue for periodic traffic flow J is closed. The gate state remains closed for 280μs. At a time offset of 1600,000,000,000,660μs, the gate state of the transmission queue for periodic traffic flow J is reopened, entering the next cycle, and so on.

[0387] For a periodic traffic flow K, at a time offset of 1600,000,000,000,260μs, the gate state of the transmission queue for periodic traffic flow K is closed. The gate state remains closed for 120μs. At a time offset of 1600,000,000,000,380μs, the gate state of the transmission queue for periodic traffic flow K is opened. The gate state remains open for 80μs. At a time offset of 1600,000,000,000,460μs, the gate state of the transmission queue for periodic traffic flow K is closed again, and the next cycle begins, and so on.

[0388] like Figure 21As shown, due to the different priorities of periodic service streams J and K, they are transmitted in different transmission queues. For ease of description, it is assumed that periodic service stream J is transmitted in transmission queue 1 and periodic service stream K is transmitted in transmission queue 0. At the time corresponding to AdminBaseTime T00, the gate state of transmission queue 1 corresponding to periodic service stream J is open, and the gate state of transmission queue 0 corresponding to periodic service stream K is closed. The second device can send periodic service stream J. The gate of transmission queue 1 is open for 120μs, and the second device completes the transmission of periodic service stream J. Until the time corresponding to T01, the gate state of each transmission queue changes. The gate state of transmission queue 1 corresponding to periodic service stream J is closed, and the gate state of transmission queue 0 corresponding to periodic service stream K is open. The second device can send periodic service stream K. The gate of transmission queue 0 is open for 80μs. The second device completes the transmission of periodic service stream K. Until time T02, the gating states of each transmission queue change again. The gating state of transmission queue 1 corresponding to periodic service stream J is closed, and the gating state of transmission queue 0 corresponding to periodic service stream K is closed. This state lasts for 200 μs until time T03. At this time, the gating state of transmission queue 1 corresponding to periodic service stream J is open, and the gating state of transmission queue 0 corresponding to periodic service stream K is closed. The second device can then transmit periodic service stream J. The gate is open for 120 μs. The second device completes the transmission of periodic service stream J until time T04, when the gating states of each transmission queue change again. The gating state of transmission queue 1 corresponding to periodic service stream J is closed, and the gating state of transmission queue 0 corresponding to periodic service stream K is closed. This state lasts for 280 μs. From time T0 to time T05, the gating operation corresponds to one cycle, namely OperaCycleTime (800 μs). The gating operation corresponding to time T00 will be repeated starting at time T05.

[0389] It should be noted that, in the above example, although periodic service stream J and periodic service stream K have different priorities and arrive at the second device at different times, the method provided in this application embodiment can ensure that the higher-priority service stream is sent first. Specifically, the priority of periodic service stream J is higher than that of periodic service stream K. By controlling the gating state and duration corresponding to the different transmission queues of periodic service streams J and K, the method provided in this application embodiment can still achieve priority transmission of the higher-priority periodic service stream J even when periodic service stream K arrives at the second device before periodic service stream J, thus avoiding the situation where periodic service stream J has to wait for periodic service stream K to finish sending before it can be sent because periodic service stream K is sending.

[0390] In some embodiments, the first device may also send information for determining the first gating scheduling parameters to the second device, which then determines the first gating scheduling parameters. The information for determining the first gating scheduling parameters may include the aforementioned first service flow transmission time / offset of the first service flow transmission time relative to the reference time, the period of the first service flow, and the maximum burst size of the first service flow. The method by which the second device determines the first gating scheduling parameters based on the above information can be referred to the above embodiments, and will not be repeated here.

[0391] The above embodiments provide a relevant implementation for configuring first interface configuration information for a second device using a first device. Of course, the first device can also configure the first interface configuration information for the second device in other ways, and no specific limitations are made here.

[0392] Regarding step S1403 above:

[0393] Optionally, in this embodiment, when the first device is a session management network element, the session management network element can notify the target access network device or the source access network device to execute the handover execution process by reusing messages in the existing handover procedure, or it can notify the target access network device or the source access network device to execute the handover execution process by introducing new messages. This embodiment does not specifically limit this. Alternatively, when the first device is a device other than a session management network element, the first device can notify the target access network device or the source access network device to execute the handover execution process by (or instruct) the session management network element. The method by which the session management network element notifies the target access network device or the source access network device to execute the handover execution process can be referred to the above description and will not be repeated here.

[0394] For example, in the Xn handover process, the session management network element can send a handover indication message to the target access network device during the handover preparation phase. This handover indication message is used to instruct the target access network device to execute the handover execution process, for example, instructing the target access network device to start execution from the first step of the handover execution process. Of course, the session management network element can also notify the target access network device to execute the handover execution process through other notification messages, and this application embodiment does not specifically limit this.

[0395] Alternatively, for example, in the N2 handover process, the session management network element (SLE) can send a PDU session update SM context response message to the mobility management network element (MLE) during the handover preparation phase. After receiving the PDU session update SM context response message, the MLE can reuse the handover command from the handover execution phase to notify the source access network device to continue the handover execution process, such as notifying the source access network device to continue other handover steps after receiving the handover command. Alternatively, the SLE can send a handover indication message to the source access network device after the handover preparation phase ends and before the handover execution phase begins. This handover indication message instructs the source access network device to continue the handover execution process. The source access network device then forwards the handover indication message to the SLE, allowing the SLE to start execution from the first step of the handover execution process. Of course, the SLE can also notify the source access network device to execute the handover execution process through other notification messages; this embodiment does not specifically limit this.

[0396] Optionally, the switching method provided in this application embodiment further includes: a first device receiving first indication information, the first indication information being used to indicate that data transmission of the first service flow on the second path is complete, the second path being the path from the first user plane network element to the source access network device / or the converter corresponding to the source access network device. Then, the first device sends second indication information to the centralized network configuration network element, the second indication information being used to indicate the deletion of information about the service flow group corresponding to the first service flow transmitted on the second path. For example, a schematic diagram of the second path can be as follows... Figure 22 As shown. Based on this scheme, after the data transmission of the first service flow on the second path is completed, the information of the service flow group corresponding to the first service flow during transmission on the second path, stored on the centralized network configuration element, can be deleted in a timely manner, saving storage space of the centralized network configuration element.

[0397] Optionally, in this embodiment, the first service flow is a downlink service flow; the interface configuration information includes second interface configuration information, which is used by the second device to send the first service flow to the target access network device through the forwarding path during the second service flow transmission time. Further optional, in this embodiment, when there is a direct tunnel between the source access network device and the target access network device, the forwarding path consists of the path from the first user plane network element to the source access network device, and the path from the source access network device to the target access network device / the corresponding converter of the target access network device, such as... Figure 23The arrows in the diagram indicate this; or, when there is no direct tunnel between the source access network device and the target access network device (which can also be understood as having an indirect tunnel), the forwarding path consists of the path from the first user plane network element to the second user plane network element, the path from the second user plane network element to the source access network device, the path from the source access network device to the second user plane network element, and the path from the second user plane network element to the target access network device / the corresponding converter of the target access network device, as shown in the diagram. Figure 24A As indicated by the arrow, the second user plane network element is an intermediate user plane network element. It should be noted that in this embodiment, the second user plane network element can be a collective term for one or more user plane network elements. For example, in an N2 handover scenario, if the intermediate user plane network element remains unchanged, the second user plane network element can be a single intermediate user plane network element, and the forwarding path is as follows: Figure 24B The arrow in the diagram points to the desired path; or, in an N2 handover scenario, if the intermediate user plane network element changes, the second user plane network element may include the source intermediate user plane network element and the target intermediate user plane network element, etc., with the forwarding path as shown below. Figure 24C As indicated by the arrow in the image, this application does not impose specific limitations on this embodiment.

[0398] Optionally, in this embodiment, the second interface configuration information includes information about the second service flow transmission time. For example, the second service flow transmission time information includes at least one of the following: the second service flow transmission time, the offset of the second service flow transmission time relative to the base time, or a second gating scheduling parameter. The second gating scheduling parameter is used by the second device to transmit the first service flow through the forwarding path during the second service flow transmission time. The second service flow transmission time can be understood as the suggested time for the second device to transmit the first service flow through the forwarding path. The implementation of configuring the second interface configuration information for the second device by the first device can refer to the configuration implementation for scenario 2 (downlink) in the above implementation of configuring the first interface configuration information for the second device. For example, the earliest transmission time T2 can be determined by referring to formula (1) or formula (6); the latest transmission time can be determined by referring to any one of formulas (7) to (10); the minimum offset can be determined by referring to formula (11) or formula (12); and the maximum offset can be determined by referring to any one of formulas (13) to (16). The second gating scheduling parameter can be referred to the description of the first gating scheduling parameter above. Similarly, the second device can determine the fourth gating scheduling parameter based on the second gating scheduling parameter. The fourth gating scheduling parameter can be referred to the description of the second gating scheduling parameter above, and will not be repeated here.

[0399] Optionally, the switching method provided in this application embodiment further includes: a first device receiving third indication information, the third indication information being used to indicate that the data transmission of the first service flow on the forwarding path is complete; the first device sending fourth indication information to the centralized network configuration element, the fourth indication information being used to indicate the deletion of the service flow group information corresponding to the first service flow during transmission on the forwarding path; and / or, the first device sending fifth indication information to the first user plane element, the fifth indication information being used to indicate the deletion of the second interface configuration information. Based on this scheme, after the data transmission of the first service flow on the forwarding path is complete, the information of the service flow group corresponding to the first service flow during transmission on the forwarding path stored in the centralized network configuration element and the second interface configuration information stored in the first user plane element can be deleted in a timely manner, thereby saving storage space in the centralized network configuration element and the first user plane element.

[0400] As an alternative, in this embodiment, the fourth indication information can also be used to indicate the completion of data transmission on the forwarding path. After receiving the fourth indication information, the centralized network configuration element can delete the information of the service flow group corresponding to the first service flow during transmission on the forwarding path. Similarly, the fifth indication information can also be used to indicate the completion of data transmission on the forwarding path. After receiving the fifth indication information, the first user plane network element can delete the second interface configuration information. This embodiment does not specifically limit this.

[0401] In the handover method provided in this application embodiment, the first device can determine the interface configuration information for the second device before executing the handover execution process, in the case where the first service flow is switched from a source access network device serving the terminal device to a target access network device serving the terminal device. The first device then sends the interface configuration information to the second device, which configures the interface associated with the interface configuration information. This interface configuration information is used by the second device to send the first service flow at the service flow sending time after receiving the first service flow. Specifically, if the first service flow is an uplink service flow, the second device is the target access network device or its corresponding converter; if the first service flow is a downlink service flow, the second device is the first user plane network element. The first device will only notify the target access network device or the source access network device to execute the handover execution process after learning from the second device that the interface associated with the interface configuration information has been configured. In other words, the handover method provided in this application embodiment can complete the interface configuration for the second device before the handover process ends, enabling the second device to send the first service flow at the service flow sending time after receiving it. Therefore, this scheme can guarantee deterministic transmission between the target access network device and the user plane network element in terminal device mobility scenarios.

[0402] The operation of the first device in steps S1401 to S1403 can be performed by... Figure 11 The processor 1101 in the communication device 1100 shown calls the application code stored in the memory 1103 to execute it, and this embodiment does not impose any restrictions on this.

[0403] like Figure 25 As shown, this application provides a switching method applied to a second device. The switching method includes the following steps:

[0404] S2501, When the second device receives interface configuration information for the second device when the first service flow switches from the source access network device serving the terminal device to the target access network device serving the terminal device.

[0405] Wherein, if the first service flow is an uplink service flow, the second device is a target access network device or a converter corresponding to the target access network device; if the first service flow is a downlink service flow, the second device is a first user plane network element.

[0406] S2502. The second device configures the interface according to the interface configuration information. This interface configuration is used by the second device to send the first service flow at the service flow sending time after receiving the first service flow.

[0407] S2503. After the second device performs interface configuration, it notifies the first device that the interface configuration is complete.

[0408] For steps S2501-S2503 above:

[0409] For a description of the first business flow, please refer to [link / reference]. Figure 14 The embodiments described herein will not be repeated here.

[0410] Optionally, in this embodiment of the application, the interface configuration information includes first interface configuration information, and a description of the first interface configuration information can be found in [reference needed]. Figure 14 The embodiments described herein will not be repeated here.

[0411] Optionally, in one possible implementation, in this embodiment of the application, for the scenario where the first service flow is a downlink service flow (i.e., scenario 2 above), the second device performs interface configuration according to the interface configuration information, including: the second device updates the interface configuration information stored locally, wherein the updated interface configuration information includes first interface configuration information, which is used to replace the initial interface configuration information. The initial interface configuration information is used by the second device to send the first service flow through the second path at the initial service flow sending time. The second path is the path from the first user plane network element to the converter corresponding to the source access network device / source access network device. For example, a schematic diagram of the second path can be shown as follows: Figure 22As shown. In other words, in this implementation, the first interface configuration information and the initial interface configuration information cannot coexist. This scheme can save storage resources of the second device while ensuring the deterministic transmission of the first service flow on the first path.

[0412] Optionally, in this embodiment, the initial interface configuration information includes information about the initial service flow transmission time. For example, the initial service flow transmission time information includes at least one of the following: the initial service flow transmission time, the offset of the initial service flow transmission time relative to a reference time, or an initial gating scheduling parameter. The initial gating scheduling parameter is used by the second device to transmit the first service flow through the second path at the initial service flow transmission time. The initial service flow transmission time can be understood as the suggested time for the second device to transmit the first service flow through the second path. It is understood that before a handover occurs at the terminal device, in order to enable the first service flow to support deterministic transmission, the first device can configure the aforementioned initial interface configuration information for the first user plane network element or the converter corresponding to the source access network device / source access network device. The relevant implementation of the first device configuring the aforementioned initial interface configuration information for the first user plane network element or the converter corresponding to the source access network device / source access network device can be found in the implementation of the first device configuring the first interface configuration information for the second device described above. The difference lies in that, when configuring the initial interface configuration information, the target access network device in the above embodiment needs to be replaced with the source access network device, and the initial interface configuration information is configured in the process before the terminal device switches. Other related information can be referred to the above embodiment, and will not be repeated here. For example, the earliest transmission time T2 can be determined by referring to the above formula (1) or formula (6); the latest transmission time can be determined by referring to any one of the above formulas (7) to (10); the minimum offset can be determined by referring to the above formula (11) or formula (12); and the maximum offset can be determined by referring to any one of the above formulas (13) to (16). The initial gating scheduling parameters can be referred to the description of the first gating scheduling parameters above. Similarly, the second device can determine the fifth gating scheduling parameters based on the initial gating scheduling parameters. The fifth gating scheduling parameters can be referred to the description of the second gating scheduling parameters above, and will not be repeated here.

[0413] Optionally, in another possible implementation, in this embodiment of the application, for the scenario where the first service flow is a downlink service flow (i.e., scenario 2 above), the second device configures the interface according to the interface configuration information, including: the second device updates the locally stored interface configuration information, wherein the updated interface configuration information includes first interface configuration information and initial interface configuration information. The initial interface configuration information is used by the second device to send the first service flow through the second path at the initial service flow sending time. The second path is the path from the first user plane network element to the source access network device. In other words, in this implementation, the first interface configuration information and the initial interface configuration information can coexist. This scheme can satisfy the deterministic transmission of the first service flow on the first path while still satisfying the deterministic transmission of the first service flow on the second path.

[0414] Optionally, in this embodiment of the application, before the handover process ends, to ensure the reliability of data transmission, the first user plane network element can simultaneously transmit the first service to both the source access network device and the target access network device. For example, the first user plane network element can copy the data packets of the first service flow (two copies in total) and send the first service flow simultaneously on the first path and the second path. This embodiment of the application does not specifically limit this.

[0415] Optionally, the updated interface configuration information may further include a first identifier, which indicates that the first interface configuration information corresponds to the first path. This scheme facilitates the differentiation of multiple sets of interface configuration information stored on the second device.

[0416] Further optionally, the switching method provided in this application embodiment includes: after the second device obtains the tunnel information of the target access network device, the second device deletes the initial interface configuration information; or, after the second device sends a data packet with an end marker corresponding to the first service flow to the source access network device, the second device deletes the initial interface configuration information. For example, after the second device sends a data packet with an end marker corresponding to the first service flow to the source access network device through the second path, the second device deletes the initial interface configuration information. Based on this scheme, the second device can delete the initial interface configuration information in a timely manner when it is not needed, thereby saving the storage resources of the second device.

[0417] Optionally, the switching method provided in this application embodiment further includes: after the second device sends a data packet with an end marker corresponding to the first service flow to the source access network device, the second device sends the first service flow through the first path according to the first interface configuration information. This solution provides a solution for when to use the first interface configuration information when multiple sets of interface configuration information are stored simultaneously on the second device. It can be understood that in this application embodiment, the second device sending the first service flow through the first path according to the first interface configuration information can also be understood as the second device updating the interface configuration information mapped to the first service flow to the first interface configuration information. This will be uniformly explained here and will not be repeated below.

[0418] Optionally, in this embodiment of the application, for the scenario where the first service flow is a downlink service flow (i.e., scenario 2 above), the interface configuration information further includes second interface configuration information, and the updated interface configuration information also includes the second interface configuration information. A description of the second interface configuration information can be found in [reference needed]. Figure 14 The aforementioned embodiments will not be elaborated further. In other words, in this implementation, the first interface configuration information and the second interface configuration information can coexist. This solution satisfies the deterministic transmission of the first service flow on the first path while still satisfying the deterministic transmission of the first service flow on the forwarding path. Alternatively, in other words, in this implementation, the first interface configuration information, the second interface configuration information, and the initial interface configuration information can coexist. This solution satisfies the deterministic transmission of the first service flow on the first path while still satisfying the deterministic transmission of the first service flow on the forwarding path and the second path.

[0419] Similarly, for the above implementation, optionally, in this embodiment, before the handover process ends, in order to ensure the reliability of data transmission, the first user plane network element can simultaneously transmit the first service to both the source access network device and the target access network device. For example, the first user plane network element can copy the data packets of the first service flow (two copies in total) and send the first service flow simultaneously on the first path and the second path. This embodiment does not specifically limit this.

[0420] Optionally, the updated interface configuration information may also include a second identifier, which indicates that the second interface configuration information is the interface configuration information corresponding to the forwarding path. Based on this scheme, it is easier to distinguish between multiple sets of interface configuration information stored on the second device.

[0421] Further optionally, the switching method provided in this application embodiment further includes: the second device receiving fifth indication information from the first device; the second device deleting the second interface configuration information according to the fifth indication information; or, after the second device sends a data packet with an end marker corresponding to the first service flow to the source access network device, the second device deletes the second interface configuration information. For example, after the second device sends a data packet with an end marker corresponding to the first service flow to the source access network device through a forwarding path, the second device deletes the initial interface configuration information. Based on this scheme, the second device can delete the second interface configuration information in a timely manner when it is not needed, thereby saving the storage resources of the second device.

[0422] In summary, in this embodiment, the second device can delete the initial interface configuration information after obtaining the tunnel information of the target access network device; and the second device can delete the second interface configuration information according to the aforementioned fifth instruction information. Alternatively, the second device can delete the initial interface configuration information after obtaining the tunnel information of the target access network device; and the second device can delete the second interface configuration information after sending a data packet with an end marker corresponding to the first service flow to the source access network device. Alternatively, the second device can delete both the initial interface configuration information and the second interface configuration information simultaneously after sending a data packet with an end marker corresponding to the first service flow to the source access network device. Alternatively, the second device can delete the initial interface configuration information after sending a data packet with an end marker corresponding to the first service flow to the source access network device; and the second device can delete the second interface configuration information according to the aforementioned fifth instruction information. This embodiment does not specifically limit the triggering conditions for deleting the initial interface configuration information and the second interface configuration information.

[0423] Optionally, the switching method provided in this application embodiment further includes: after the second device obtains the tunnel information of the target access network device, the second device sends the first service flow through the forwarding path according to the second interface configuration information. This solution provides a solution for when to use the second interface configuration information when multiple sets of interface configuration information are stored simultaneously on the second device. It can be understood that in this application embodiment, the second device sending the first service flow through the forwarding path according to the second interface configuration information can also be understood as the second device updating the interface configuration information mapped to the first service flow to the second interface configuration information. This will be explained uniformly here and will not be repeated below.

[0424] In other words, according to the above method, in the downlink scenario, before handover, the second device (first user plane network element) sends the first service flow through the second path from the first user plane network element to the source access network device according to the initial interface configuration information, which can achieve deterministic transmission between the source access network device and the first user plane network element. After the second device obtains the tunnel information of the target access network device, the second device (first user plane network element) sends the first service flow through the forwarding path from the first user plane network element to the target access network device according to the second interface configuration information, which can achieve deterministic transmission between the target access network device and the first user plane network element when the first service flow is transmitted on the forwarding path. After the second device sends the data packet with the end marker corresponding to the first service flow to the source access network device, the second device (first user plane network element) sends the first service flow through the first path from the first user plane network element to the target access network device according to the first interface configuration information, which can achieve deterministic transmission between the target access network device and the first user plane network element when the first service flow is transmitted on the first path. Therefore, deterministic transmission between the access network device and the user plane network element can be achieved in each stage of handover.

[0425] Optionally, in embodiments of this application, for scenarios where the second device is the target access network device, the handover method provided in this application further includes: after the second device notifies the first device that the interface configuration is complete, the handover execution process is executed according to the notification from the first device. Based on this scheme, the interface configuration for the second device can be completed before the handover process ends. Thus, after the handover process ends, once the second device receives the first service flow, it can promptly send the first service flow according to the interface configuration at the service flow sending time, thereby satisfying the deterministic transmission between the target access network device and the user plane network element.

[0426] In the handover method provided in this application embodiment, the second device can receive interface configuration information for itself when the first service flow switches from a source access network device serving the terminal device to a target access network device serving the terminal device. After configuring the interface according to the interface configuration information, the second device notifies the first device that the interface configuration is complete. This interface configuration is used by the second device to send the first service flow at the service flow transmission time after receiving the first service flow. Wherein, if the first service flow is an uplink service flow, the second device is the target access network device or a converter corresponding to the target access network device; if the first service flow is a downlink service flow, the second device is the first user plane network element. In other words, the handover method provided in this application embodiment can enable the second device to send the first service flow at the service flow transmission time after receiving it through interface configuration. Therefore, this scheme can meet the deterministic transmission between the target access network device and the user plane network element in terminal device mobility scenarios.

[0427] The operation of the second device in steps S2501 to S2503 can be performed by... Figure 11 The processor 1101 in the communication device 1100 shown calls the application code stored in the memory 1103 to execute it, and this embodiment does not impose any restrictions on this.

[0428] The following will combine, for example, Figure 7A or Figure 7B or Figure 8A or Figure 8B or Figure 9 The network architecture combining 5GS with TSN / non-TSN TSC illustrated in this application illustrates the handover method provided in the embodiments of this application. Of course, the handover method provided in the embodiments of this application is not limited to the network architecture combining 5GS with TSN / non-TSN TSC, and can also be applied to other future communication systems, such as network architectures combining 6G systems with TSN or other systems. Furthermore, the names of the various network elements used in the embodiments of this application may remain functionally the same in future communication systems, but their names may change.

[0429] It should be noted that the message names between network elements or the names of parameters in the messages in the following embodiments of this application are just examples. Other names may be used in the specific implementation. This application does not limit them in this respect.

[0430] First, taking the above-mentioned business flow scenario (i.e., scenario 1 above) as an example, combined with the above... Figure 7A and Figure 7B The architecture shown illustrates the switching method provided in the embodiments of this application. Assume... Figure 7A and Figure 7B The gNB in ​​the above-mentioned terminal device is the target gNB that serves the terminal device after the handover. Figure 7A and Figure 7B The UPF network element in this context is the aforementioned UPF1 network element. Therefore, in this handover method, Figure 7A and Figure 7B The SMF network element in the above-mentioned device is used to implement the functions of the first device. Figure 7A and Figure 7B The gNB or the AN-TT corresponding to the gNB is used to implement the functions of the second device mentioned above. Figure 7A and Figure 7B The UPF network element in the network is used to implement the functions of the aforementioned third device. For example, such as... Figure 26 As shown, a switching method provided in an embodiment of this application includes the following steps:

[0431] S2601. When a terminal device determines that it needs to switch from the source gNB serving the terminal device to the target gNB, the target gNB learns during the handover preparation phase that the terminal device needs to switch to the target gNB, and the first service flow to be switched supports deterministic transmission.

[0432] The existing handover process includes Xn handover and N2 handover. Both Xn handover and N2 handover processes include a handover preparation phase and a handover execution phase. The specific process by which the target gNB learns that the terminal device wants to hand over to the target gNB during the handover preparation phase of Xn handover can be referred to the handover preparation phase process of Xn handover. The specific process by which the target gNB learns that the terminal device wants to hand over to the target gNB during the handover preparation phase of N2 handover can be referred to the handover preparation phase process of N2 handover. It will not be repeated here.

[0433] Optionally, in this embodiment, the first service flow supporting deterministic transmission means that the service flow supports interoperability with a deterministic transmission network (such as a transmission network that supports TSN or TSC). This will be explained uniformly here and will not be repeated below.

[0434] As described above, the first service flow in the embodiments of this application can be a TSC flow or a QoS flow, or the first service flow can refer to a PDU session.

[0435] In one possible implementation, if the first service flow refers to a PDU session, corresponding indication information can be added to the session context of that PDU session. This indication information is used to indicate that the PDU session supports deterministic transmission. Furthermore, during the handover preparation phase, after the target gNB obtains the session context of the PDU session, it can determine that the PDU session supports deterministic transmission based on the indication information in the session context.

[0436] Alternatively, in one possible implementation, if the first service flow is a QoS flow, corresponding indication information can be added to the QoS profile corresponding to that QoS flow. This indication information is used to indicate that the QoS flow supports deterministic transmission. Then, during the handover preparation phase, after the target gNB obtains the QoS profile corresponding to the QoS flow, it can determine that the QoS flow supports deterministic transmission based on the indication information in the QoS profile.

[0437] S2602, the target gNB or the AN-TT corresponding to the target gNB sends the processing time information and port information of the AN-TT corresponding to the target gNB to the SMF network element. Correspondingly, the SMF network element receives the processing time information and port information of the AN-TT corresponding to the target gNB from the target gNB or the AN-TT corresponding to the target gNB.

[0438] Specifically, the AN-TT port information includes an identifier for each port, which comprises the MAC address and interface name of each port. Furthermore, the AN-TT port information may also include other parameters, which are not limited in this application. Optionally, in the embodiments of this application, the AN-TT port information may also include AN-TT port capability information, such as the rate at which service flows are transmitted through the AN-TT port, which is not specifically limited in this embodiment.

[0439] For example, the specific implementation of the target gNB or its corresponding AN-TT sending the processing time information and port information of the AN-TT corresponding to the target gNB to the SMF network element can be found in [reference needed]. Figure 14 The implementation related to scenario 1 in the embodiment described above, where the first device obtains the processing time information of the second device from the second device, will not be repeated here.

[0440] Although not shown, alternatively, as a solution, the SMF network element can also obtain the AN-TT processing time information and AN-TT port information corresponding to the target gNB from the source gNB serving the terminal device. For example, the source gNB sends the AN-TT processing time information and AN-TT port information corresponding to the target gNB to the SMF network element. The AN-TT processing time information and AN-TT port information corresponding to the target gNB can be pre-configured on the source gNB, or they can be sent from the target gNB to the source gNB; this embodiment does not specifically limit this.

[0441] S2603 and SMF network elements determine the information of the service flow group (hereinafter referred to as the information of service flow group 1) corresponding to the first service flow transmitted on the first path in the uplink scenario, based on the processing time information and port information of the AN-TT corresponding to the target gNB. Among them, the first path is the path from the second device to the UPF1 network element, and the second device is the target gNB or the AN-TT corresponding to the target gNB.

[0442] In this embodiment, the information of service flow group 1 includes the identifier of the first service flow (such as StreamID or MAC address), minimum offset 1, and maximum offset 1. The minimum offset 1 is the minimum offset of the time the second device sends the first service flow through the first path relative to the reference time; it can also be understood as the offset of the earliest transmission time of the first service flow transmitted through the first path on the second device relative to the reference time. The maximum offset 1 is the maximum offset of the time the second device sends the first service flow through the first path relative to the reference time; it can also be understood as the offset of the latest transmission time of the first service flow transmitted through the first path on the second device relative to the reference time.

[0443] For example, the minimum offset 1 can be determined with reference to the above formula (11) or formula (12); the maximum offset 1 can be determined with reference to any of the above formulas (13) to (16), which will not be repeated here. Among them, the second device in the above formulas (11) to (16) corresponds to the target gNB or the AN-TT corresponding to the target gNB in ​​the embodiments of this application, and the third device corresponds to the UPF1 network element in the embodiments of this application.

[0444] Optionally, in this embodiment of the application, the information of service flow group 1 may also include one or more of the following parameters: TSN sender information and TSN receiver information corresponding to the first service flow, priority (StreamRank) of the first service flow, period (Interval) of the first service flow, maximum number of frames that can be sent per unit time length (MaxFramesPerInterval), maximum burst size, UserToNetworkRequirements parameter, or jitter.

[0445] The information in service flow group 1 includes the TSN sending end information corresponding to the first service flow, which can be, for example, the AN-TT port information corresponding to the target gNB. The information in service flow group 1 also includes the TSN receiving end information corresponding to the first service flow, which can be, for example, the N3-TT port information corresponding to the UPF1 network element. The description of the N3-TT port information can be found in the description of the AN-TT port information above, and will not be repeated here. Furthermore, the period of the first service flow is carried in the TSC auxiliary container of the PCC rule sent from the PCF network element to the SMF network element. The priority (StreamRank) and maximum burst size of the first service flow are carried in the service requirement description parameters of the PCC rule sent from the PCF network element to the SMF network element. Jitter can be determined by the SMF network element; relevant descriptions can be found in [reference needed]. Figure 14 The described embodiments will not be repeated here. The following is a brief description of other parameters:

[0446] The maximum number of frames that can be sent per unit time (MaxFramesPerInterval) defines the maximum number of frames that the second device can send within one interval. Since the terminal device switches from the source gNB to the target gNB, after the switch, this parameter refers to the maximum number of frames that the target gNB or its corresponding AN-TT can send within one interval. This can be reported to the SMF network element as capability information of the target gNB or its corresponding AN-TT. The implementation method of the SMF network element obtaining MaxFramesPerInterval can be found in the specific implementation of the SMF network element obtaining the processing time information and port information of the AN-TT corresponding to the target gNB in ​​the above embodiment, and will not be repeated here.

[0447] User-to-NetworkRequirements define the latency and redundancy requirements of the first service flow, and may include the following parameters:

[0448] The first service flow's maximum latency requirement between the second and third devices (UserToNetworkRequirements.MaxLatency) and redundancy requirement between the second and third devices (UserToNetworkRequirements.NumSeamlessTrees).

[0449] UserToNetworkRequirements.MaxLatency defines the maximum latency requirement for the first service flow when it is transmitted between the second and third devices. For a related description, please refer to [link / reference]. Figure 14 The embodiments described herein will not be repeated here.

[0450] In this embodiment of the application, UserToNetworkRequirements.NumSeamlessTrees defines the number of paths that require redundant transmission when the first service flow is transmitted between the second and third devices. For example, the SMF network element can configure the value of UserToNetworkRequirements.NumSeamlessTrees to 1.

[0451] It is understood that, in this embodiment of the application, since the UPF1 network element remains unchanged, the processing time information of the UPF1 network element required by the SMF network element when determining the information of service flow group 1 (e.g., the processing time information of the UPF1 network element is required when determining the latest transmission time according to formula (9)) and / or the port information of the N3-TT corresponding to the aforementioned UPF1 network element can be obtained by the SMF network element in the process before the handover, or it can be obtained in the handover preparation stage, so it is not shown in the flowchart. Specifically, the relevant implementation of the SMF network element obtaining the processing time information of the UPF1 network element and / or the port information of the N3-TT corresponding to the UPF1 network element can be referred to Figure 14 The description of scenario 2 in the implementation of the first device obtaining the processing time information of the second device from the second device in the above embodiments will not be repeated here.

[0452] S2604. The SMF network element sends information about service flow group 1 to the CNC-TN network element. Correspondingly, the CNC-TN network element receives information about service flow group 1 from the SMF network element.

[0453] S2605 and CNC-TN network elements determine the offset selection value 1 corresponding to the first service flow based on the minimum offset 1 and maximum offset 1 contained in the information of service flow group 1.

[0454] The method by which the CNC-TN network element determines the offset selection value 1 corresponding to the first service flow based on the minimum offset 1 and maximum offset 1 contained in the information of service flow group 1 can be referred to [reference needed]. Figure 14 The description of the fourth device determining the offset selection value in the above embodiments will not be repeated here.

[0455] Optionally, in this embodiment of the application, the CNC-TN network element can also configure the first service flow according to the TSN transmitter and TSN receiver information corresponding to the first service flow. The relevant description can be referred to the prior art, and will not be repeated here.

[0456] S2606, the CNC-TN network element sends the identifier of the first service flow, the interface identifier (InterfaceID), and the offset selection value 1 corresponding to the first service flow to the SMF network element. Correspondingly, the SMF network element receives the identifier of the first service flow, the InterfaceID, and the offset selection value 1 corresponding to the first service flow from the CNC-TN network element.

[0457] Among them, InterfaceID is used to identify a port indicated by the AN-TT port information corresponding to the target gNB in ​​step S2602.

[0458] Optionally, in this embodiment of the application, after the SMF obtains the offset selection value 1 corresponding to the first service flow, it can also determine the time when the second device sends the first service flow through the first path (hereinafter referred to as the first service flow sending time) based on the offset selection value 1 corresponding to the first service flow.

[0459] Optionally, in this embodiment of the application, the SMF network element can also determine the offset selection value 1 based on the minimum offset 1 and the maximum offset 1. The relevant implementation can refer to the way the CNC-TN network element determines the offset selection value 1, which will not be described in detail here.

[0460] The S2607 and SMF network elements determine the first gating scheduling parameters corresponding to the first service flow's transmission through the first path via the port indicated by the InterfaceID, based on the identifier of the first service flow, the InterfaceID, and the offset corresponding to the first service flow, selecting a value of 1. A description of the first gating parameters can be found in [reference needed]. Figure 14 The embodiments described herein will not be repeated here.

[0461] S2608, the SMF network element sends the identifier of the first service flow, the interface identifier (InterfaceID), and the first interface configuration information to the target gNB or the AN-TT corresponding to the target gNB. Correspondingly, the target gNB or the AN-TT corresponding to the target gNB receives the identifier of the first service flow, the interface identifier (InterfaceID), and the first interface configuration information from the SMF network element. The first interface configuration information is used by the target gNB or the AN-TT corresponding to the target gNB to send the first service flow through the first path at the first service flow transmission time.

[0462] Optionally, in this embodiment, the first interface configuration information includes information about the first service flow transmission time. For example, the information about the first service flow transmission time includes at least one of: the first service flow transmission time, the offset of the first service flow transmission time relative to a reference time (i.e., the offset selection value 1 corresponding to the first service flow mentioned above), or a first gating scheduling parameter. The first gating scheduling parameter is used for the target gNB or the AN-TT corresponding to the target gNB to transmit the first service flow through the first path at the first service flow transmission time.

[0463] Optionally, in this embodiment of the application, the priority of the SMF network element sending the first service flow to the target gNB or the AN-TT corresponding to the target gNB is not specifically limited in this embodiment of the application.

[0464] S2609. The target gNB or its corresponding AN-TT configures the interface according to the first interface configuration information. This interface configuration is used by the target gNB or its corresponding AN-TT to send the first service flow through the first path at the first service flow transmission time after receiving the first service flow.

[0465] Optionally, in this embodiment of the application, the target gNB or the AN-TT corresponding to the target gNB performs interface configuration according to the first interface configuration information, including: the target gNB or the AN-TT corresponding to the target gNB locally stores the first interface configuration information.

[0466] Optionally, in this embodiment, if the first interface configuration information includes a first gating scheduling parameter, then after the target gNB or the AN-TT corresponding to the target gNB obtains the first gating scheduling parameter, it can determine the third gating scheduling parameter based on the first gating scheduling parameter. Related implementations can be found in [reference needed]. Figure 14 The embodiments described herein will not be repeated here.

[0467] S2610. After the configuration information of the first interface is completed, the target gNB or the AN-TT corresponding to the target gNB notifies the SMF network element that the interface configuration is complete.

[0468] In this embodiment, the target gNB or the AN-TT corresponding to the target gNB can be configured by reusing the message notification SMF network element interface in the existing handover process, or it can be configured by the newly introduced message notification SMF network element interface. This embodiment does not specifically limit this.

[0469] For example, in the handover preparation phase of the Xn handover process, after the first interface configuration information is configured, the target gNB or the AN-TT corresponding to the target gNB can send a configuration completion indication message to the SMF network element. This configuration completion indication message is used to indicate that the interface configuration is complete. Alternatively, for example, in the handover preparation phase or handover execution phase of the N2 handover process, after the first interface configuration information is configured, the target gNB or the AN-TT corresponding to the target gNB can send a configuration completion indication message to the SMF network element. This configuration completion indication message is used to indicate that the interface configuration is complete.

[0470] Of course, the target gNB or the AN-TT corresponding to the target gNB can also notify the SMF network element interface configuration is complete through other means, and this application embodiment does not specifically limit this.

[0471] S2611. After the SMF network element learns from the target gNB or the AN-TT corresponding to the target gNB that the interface configuration associated with the first interface configuration information has been completed, it notifies the target gNB or the source gNB (not shown) to execute the handover execution process.

[0472] In this embodiment of the application, the SMF network element can execute the handover execution process by reusing the message notification in the existing handover process to the target gNB or the source gNB (not shown), or by notifying the target gNB or the source gNB (not shown) of the handover execution process by newly introduced messages. This embodiment of the application does not specifically limit this.

[0473] For example, in the Xn handover process, after the SMF network element learns from the target gNB or the AN-TT corresponding to the target gNB that the interface configuration associated with the first interface configuration information is complete, it can notify the target gNB to execute the handover execution process. For instance, the SMF network element can send a handover indication message to the target gNB during the handover preparation phase. This handover indication message is used to instruct the target gNB to execute the handover execution process, such as instructing the target gNB to start execution from the first step of the handover execution process. Of course, the SMF network element can also notify the target gNB to execute the handover execution process through other notification messages, and this application embodiment does not specifically limit this.

[0474] Alternatively, for example, in the N2 handover process, after the SMF network element learns from the target gNB or the AN-TT corresponding to the target gNB that the interface configuration associated with the first interface configuration information is complete, it can notify the source gNB (not shown) to execute the handover execution process. For example, the SMF network element can send a PDU session update SM context response message to the AMF network element during the handover preparation phase; after receiving the PDU session update SM context response message, the AMF network element can reuse the handover command from the handover execution phase to notify the source gNB (not shown) to continue executing the handover execution process, such as notifying the source gNB to continue executing other handover steps after receiving the handover command; or, the SMF network element can send a handover indication message to the source gNB after the handover preparation phase and before the start of the handover execution phase. This handover indication message is used to instruct the source gNB to continue executing the handover execution process, and then the source gNB forwards the handover indication message to the SMF network element so that the SMF network element starts executing from the first step of the handover execution process. Of course, the SMF network element can also notify the source gNB to continue the handover process through other notification messages, and this application embodiment does not specifically limit this.

[0475] S2612. The target gNB (or source gNB) executes the handover procedure according to the notification from the SMF network element. The handover procedure can refer to existing technologies and will not be described in detail here.

[0476] This concludes the handover method provided in this application embodiment. The handover method provided in this application embodiment can complete the interface configuration for the second device before the handover process ends, enabling the second device to send the first service flow after receiving it during the service flow transmission time. Therefore, this solution can satisfy the deterministic transmission on the first path between the target gNB and the UPF1 network element in terminal device mobility scenarios.

[0477] The actions of the SMF network element in steps S2601 to S2612 above can be performed by... Figure 11 The processor 1101 in the communication device 1100 shown executes the application code stored in the memory 1103. The actions of the target gNB or the AN-TT corresponding to the target gNB in ​​the above steps S2601 to S2612 can be performed by... Figure 11 The processor 1101 in the communication device 1100 shown calls the application code stored in the memory 1103 to execute the application code. This embodiment does not impose any limitations on this.

[0478] Secondly, taking the following business flow scenario (i.e., scenario 2 above) as an example, combined with the above... Figure 7A and Figure 7B The architecture shown illustrates the switching method provided in the embodiments of this application. Assume... Figure 7A and Figure 7B The gNB in ​​the above-mentioned terminal device is the target gNB that serves the terminal device after the handover. Figure 7A and Figure 7B The UPF network element in this context is the aforementioned UPF1 network element. Therefore, in this handover method, Figure 7A and Figure 7B The SMF network element in the above-mentioned device is used to implement the functions of the first device. Figure 7A and Figure 7B The UPF network element in the network is used to implement the functions of the second device described above. For example, such as... Figure 27 As shown, a switching method provided in an embodiment of this application includes the following steps:

[0479] S2701. When a terminal device determines that it needs to switch from a source gNB serving the terminal device to a target gNB, the target gNB learns during the handover preparation phase that the terminal device needs to switch to the target gNB, and the first service flow to be switched supports deterministic transmission.

[0480] For a description of step S2701, please refer to [link / reference]. Figure 26 Step S2601 in the embodiments described herein will not be repeated here.

[0481] S2702, the target gNB or the AN-TT corresponding to the target gNB sends a sixth indication message to the SMF network element, and correspondingly, the SMF network element receives the sixth indication message from the target gNB or the AN-TT corresponding to the target gNB. The sixth indication message indicates that the terminal device needs to switch to the target gNB, and that the first service flow to be switched supports deterministic transmission.

[0482] Optionally, in this embodiment, the target gNB or the AN-TT corresponding to the target gNB may also send the processing time information and / or port information of the AN-TT corresponding to the target gNB to the SMF network element. A description of the processing time information and / or port information of the AN-TT corresponding to the target gNB can be found in [reference needed]. Figure 26 The embodiments described herein will not be repeated here.

[0483] Based on the processing time information of the UPF1 network element and the port information of the N3-TT corresponding to the UPF1 network element, the S2703 and SMF network elements determine the information of the service flow group (hereinafter referred to as the information of service flow group 2) corresponding to the first service flow transmitted on the first path in the downlink scenario. Among them, the first path is the path from the UPF1 network element to the third device, and the third device is the target gNB or the AN-TT corresponding to the target gNB.

[0484] It is understood that, in this embodiment of the application, since the UPF1 network element remains unchanged, the processing time information of the UPF1 network element and the N3-TT port information corresponding to the UPF1 network element required by the SMF network element when determining the information of service flow group 2 can be obtained by the SMF network element in the process before handover or in the handover preparation phase; therefore, they are not illustrated in the flowchart. Specifically, the relevant implementation for the SMF network element to obtain the processing time information of the UPF1 network element and the N3-TT port information corresponding to the UPF1 network element can be found in [reference needed]. Figure 14 The description of scenario 2 in the implementation of the first device obtaining the processing time information of the second device from the second device in the above embodiments will not be repeated here.

[0485] In this embodiment, the information of service flow group 2 includes the identifier of the first service flow (such as StreamID or MAC address), minimum offset 2, and maximum offset 2. The minimum offset 2 is the minimum offset of the time when the UPF1 network element sends the first service flow through the first path relative to the reference time; it can also be understood as the offset of the earliest transmission time of the first service flow transmitted through the first path within the UPF1 network element relative to the reference time. The maximum offset 2 is the maximum offset of the time when the UPF1 network element sends the first service flow through the first path relative to the reference time; it can also be understood as the offset of the latest transmission time of the first service flow transmitted through the first path within the UPF1 network element relative to the reference time.

[0486] For example, the minimum offset 2 can be determined with reference to the above formula (11) or formula (12); the maximum offset 2 can be determined with reference to any of the above formulas (13) to (16), which will not be repeated here. Among them, the second device in the above formulas (11) to (16) corresponds to the UPF1 network element in the embodiment of this application, and the third device corresponds to the target gNB or the AN-TT corresponding to the target gNB in ​​the embodiment of this application.

[0487] Optionally, in this embodiment of the application, the information of the service flow group 2 may also include one or more of the following parameters: TSN sender information and TSN receiver information corresponding to the first service flow, priority (StreamRank) of the first service flow, period (Interval) of the first service flow, maximum number of frames that can be sent per unit time length (MaxFramesPerInterval), maximum burst size, UserToNetworkRequirements parameter, or jitter.

[0488] The information in service flow group 2 includes, for example, the TSN transmitter information corresponding to the first service flow, which could be the N3-TT port information corresponding to the UPF1 network element. The information in service flow group 2 also includes, for example, the AN-TT port information corresponding to the target gNB. Furthermore, descriptions of the first service flow's priority (StreamRank), interval, maximum burst size, UserToNetworkRequirements parameters, or jitter can be found in [reference needed]. Figure 26 The described embodiments will not be repeated here. The following is a brief description of other parameters:

[0489] The maximum number of frames that can be sent per unit time (MaxFramesPerInterval) defines the maximum number of frames that a UPF1 network element can send within one interval. Since the terminal device switches from the source gNB to the target gNB, the UPF1 network element remains unchanged after the switch, therefore this parameter does not change before or after the switch. In this embodiment, this parameter can be reported to the SMF network element as the capability information of the UPF1 network element. The implementation method of the SMF network element obtaining MaxFramesPerInterval can be referred to in the above embodiment for the specific implementation of the SMF network element obtaining the processing time information of the UPF1 network element and the port information of the corresponding N3-TT of the UPF1 network element, and will not be repeated here.

[0490] It is understood that, in the embodiments of this application, the processing time information of the AN-TT corresponding to the target gNB required by the SMF network element when determining the information of the service flow group 2 (for example, the processing time information of the AN-TT corresponding to the target gNB is required when determining the latest transmission time according to formula (9)) and / or the port information of the AN-TT corresponding to the target gNB can be actively sent to the SMF network element by the target gNB, or it can be requested by the SMF network element from the target gNB. The embodiments of this application do not specifically limit this.

[0491] S2704. The SMF network element sends information about service flow group 2 to the CNC-TN network element. Correspondingly, the CNC-TN network element receives information about service flow group 2 from the SMF network element.

[0492] Optionally, in this embodiment of the application, the CNC-TN network element can also configure the first service flow according to the TSN transmitter and TSN receiver information corresponding to the first service flow. The relevant description can be referred to the prior art, and will not be repeated here.

[0493] S2705 and CNC-TN network elements determine the offset selection value 2 corresponding to the first service flow based on the minimum offset 2 and maximum offset 2 contained in the information of service flow group 2.

[0494] The method by which the CNC-TN network element determines the offset selection value 2 corresponding to the first service flow based on the minimum offset 2 and maximum offset 2 contained in the information of service flow group 2 can be referred to [reference needed]. Figure 14 The description of the fourth device determining the offset selection value in the above embodiments will not be repeated here.

[0495] S2706, the CNC-TN network element sends the identifier of the first service flow, the interface identifier (InterfaceID), and the offset selection value 2 corresponding to the first service flow to the SMF network element. Correspondingly, the SMF network element receives the identifier of the first service flow, the InterfaceID, and the offset selection value 2 corresponding to the first service flow from the CNC-TN network element.

[0496] Among them, InterfaceID is used to identify a port indicated by the N3-TT port information corresponding to the UPF1 network element in step S2703.

[0497] Optionally, in this embodiment of the application, after the SMF obtains the offset selection value 2 corresponding to the first service flow, it can also determine the time when the second device sends the first service flow through the first path (hereinafter referred to as the first service flow sending time) based on the offset selection value 2 corresponding to the first service flow.

[0498] Optionally, in this embodiment of the application, the SMF network element can also determine the offset selection value 2 based on the minimum offset 2 and the maximum offset 2. The relevant implementation can refer to the way the CNC-TN network element determines the offset selection value 2, which will not be described in detail here.

[0499] The S2707 and SMF network elements determine the first gating scheduling parameters corresponding to the first service flow's transmission through the first path via the port indicated by the InterfaceID, based on the identifier of the first service flow, the InterfaceID, and the offset value 2 corresponding to the first service flow. A description of the first gating parameters can be found in [reference needed]. Figure 14 The embodiments described herein will not be repeated here.

[0500] S2708, the SMF network element sends the identifier of the first service flow, the interface identifier (InterfaceID), and the first interface configuration information to the UPF1 network element. Correspondingly, the UPF1 network element receives the identifier of the first service flow, the interface identifier (InterfaceID), and the first interface configuration information from the SMF network element. The first interface configuration information is used by the UPF1 network element to send the first service flow through the first path at the first service flow transmission time.

[0501] Optionally, in this embodiment, the first interface configuration information includes information about the first service flow transmission time. For example, the information about the first service flow transmission time includes at least one of: the first service flow transmission time, the offset of the first service flow transmission time relative to a reference time (i.e., the offset selection value 2 corresponding to the first service flow mentioned above), or a first gating scheduling parameter. The first gating scheduling parameter is used by the UPF1 network element to transmit the first service flow through the first path at the first service flow transmission time.

[0502] Optionally, in this embodiment of the application, the priority of the SMF network element sending the first service flow to the UPF1 network element is not specifically limited in this embodiment of the application.

[0503] S2709 and UPF1 network elements configure their interfaces according to the first interface configuration information. This interface configuration is used by the UPF1 network element to send the first service flow via the first path after receiving it, at the first service flow transmission time.

[0504] In one possible implementation, in this embodiment of the application, the UPF1 network element configures the interface according to the first interface configuration information, including: the UPF1 network element updates the interface configuration information stored locally, wherein the updated interface configuration information includes the first interface configuration information, the first interface configuration information is used to replace the initial interface configuration information, and the initial interface configuration information is used by the UPF1 network element to send the first service flow through the second path at the initial service flow sending time.

[0505] Optionally, in this embodiment, the initial interface configuration information includes information about the initial service flow transmission time. For example, the initial service flow transmission time information includes at least one of the following: the initial service flow transmission time, the offset of the initial service flow transmission time relative to a reference time (hereinafter referred to as offset selection value 3), or initial gating scheduling parameters. The initial gating scheduling parameters are used by the UPF1 network element to transmit the first service flow through the second path at the initial service flow transmission time. Related descriptions can be found in [reference]. Figure 14 The aforementioned embodiments will not be elaborated further. In this implementation, the first interface configuration information and the initial interface configuration information cannot coexist. This solution, while ensuring the deterministic transmission of the first service flow on the first path, can save storage resources on the second device.

[0506] In another possible implementation, in this embodiment, the UPF1 network element configures its interface according to the first interface configuration information, including: the UPF1 network element updates the locally stored interface configuration information, wherein the updated interface configuration information includes the first interface configuration information and initial interface configuration information. The initial interface configuration information is used by the UPF1 network element to send the first service flow through the second path at the initial service flow sending time. In this implementation, the first interface configuration information and the initial interface configuration information can coexist. This scheme can satisfy the deterministic transmission of the first service flow on the first path while still satisfying the deterministic transmission of the first service flow on the second path.

[0507] For the aforementioned implementation method where the first interface configuration information and the initial interface configuration information coexist, optionally, the updated interface configuration information also includes a first identifier, which indicates that the first interface configuration information is the interface configuration information corresponding to the first path. Based on this scheme, it is easier to distinguish multiple sets of interface configuration information stored on the second device.

[0508] Optionally, in this embodiment, if the first interface configuration information includes a first gating scheduling parameter, the UPF1 network element can determine the third gating scheduling parameter based on the first gating scheduling parameter after obtaining it. Related implementations can be found in [reference needed]. Figure 14 The embodiments described herein will not be repeated here.

[0509] S2710. After the configuration information of the first interface is completed, the UPF1 network element notifies the SMF network element that the interface configuration is complete.

[0510] In this embodiment, the UPF1 network element can complete the configuration by reusing the message notification SMF network element interface configuration in the existing handover process, or it can complete the configuration by newly introduced message notification SMF network element interface configuration. This embodiment does not specifically limit this.

[0511] For example, in the handover preparation phase of the Xn handover process, after the first interface configuration information is configured, the UPF1 network element can send a configuration completion indication message to the SMF network element. This configuration completion indication message is used to indicate that the interface configuration is complete. Alternatively, for example, in the handover preparation phase or handover execution phase of the N2 handover process, after the first interface configuration information is configured, the UPF1 network element can send a configuration completion indication message to the SMF network element. This configuration completion indication message is used to indicate that the interface configuration is complete.

[0512] Of course, the UPF1 network element can also notify the SMF network element that the interface configuration is complete through other means, and this application embodiment does not specifically limit this.

[0513] S2711 After the SMF network element learns from the UPF1 network element that the interface configuration associated with the first interface configuration information is complete, it notifies the target gNB or the source gNB (not shown) to execute the handover execution process.

[0514] The implementation details regarding the SMF network element's notification of the target gNB or source gNB (not shown) to execute the handover process can be found in [reference needed]. Figure 26 The embodiments described herein will not be repeated here.

[0515] S2712. The target gNB (or source gNB) executes the handover procedure according to the notification from the SMF network element. The handover procedure can refer to existing technologies and will not be described in detail here.

[0516] It is understood that, in this embodiment of the application, for the implementation method where the first interface configuration information and the initial interface configuration information coexist, the CNC-TN network element can not only store the information of service flow group 2, but also simultaneously store the information of the service flow group corresponding to the first service flow transmitted on the second path in the downlink scenario (hereinafter referred to as the information of service flow group 3). The information of service flow group 3 includes the identifier of the first service flow, the minimum offset 3, and the maximum offset 3. The minimum offset 3 is the minimum offset of the time when the UPF1 network element sends the first service flow through the second path relative to the reference time; it can also be understood as the offset of the earliest transmission time of the first service flow transmitted through the second path in the UPF1 network element relative to the reference time. The maximum offset 3 is the maximum offset of the time when the UPF1 network element sends the first service flow through the second path relative to the reference time; it can also be understood as the offset of the latest transmission time of the first service flow transmitted through the second path in the UPF1 network element relative to the reference time. Optionally, the information of service flow group 3 may also include one or more of the following parameters: TSN transmitter and receiver information corresponding to the first service flow, priority (StreamRank) of the first service flow, period (Interval) of the first service flow, maximum number of frames that can be sent per unit time length (MaxFramesPerInterval), maximum burst size, UserToNetworkRequirements parameter, or jitter. The TSN transmitter information corresponding to the first service flow included in the information of service flow group 3 may, for example, be the N3-TT port information corresponding to the UPF1 network element, and the TSN receiver information corresponding to the first service flow included in the information of service flow group 3 may, for example, be the AN-TT port information corresponding to the source gNB. The descriptions of the other parameters mentioned above can be found in step S2703 and will not be repeated here.

[0517] Based on the above scheme, optionally, the switching method provided in this application embodiment further includes: the SMF network element receiving first indication information, the first indication information being used to indicate that the data transmission of the first service flow on the second path is complete. Then, the SMF network element sends second indication information to the CNC-TN network element, the second indication information being used to indicate the deletion of information for service flow group 3.

[0518] For example, in the Xn handover process or the N2 handover process, the SMF network element receiving the first indication information may include: the SMF network element receiving a PDU session update SMcontext request from the AMF network element, the PDU session update SMcontext request carrying the aforementioned first indication information.

[0519] Based on the above scheme, after the data transmission of the first service flow on the second path is completed, the information of service flow group 3 stored on the CNC-TN network element can be deleted in a timely manner, saving the storage space of the CNC-TN network element.

[0520] Optionally, in the embodiments of this application, for the implementation of the coexistence of the first interface configuration information and the initial interface configuration information, the switching method provided in the embodiments of this application may further include: after the UPF1 network element obtains the tunnel information of the target gNB, the UPF1 network element deletes the initial interface configuration information; or, after the UPF1 network element sends the data packet with the end marker corresponding to the first service flow to the source gNB, the UPF1 network element deletes the initial interface configuration information.

[0521] For example, in the Xn handover process or the N2 handover process, the UPF1 network element obtaining the tunnel information of the target gNB may include: the UPF1 network element receiving an N4 session modification request from the SMF network element, which includes the tunnel information of the target gNB.

[0522] For example, in this embodiment of the application, the end marker may be an end marker.

[0523] Based on the above scheme, the UPF1 network element can promptly delete the initial interface configuration information when it is not needed, thereby saving the storage resources of the UPF1 network element.

[0524] Optionally, the switching method provided in this application embodiment further includes: after the UPF1 network element sends a data packet with an end marker corresponding to the first service flow to the source gNB, the UPF1 network element sends the first service flow through the first path according to the first interface configuration information. This solution provides a solution for when to use the first interface configuration information when multiple sets of interface configuration information are stored on the UPF1 network element at the same time. It can be understood that in this application embodiment, the UPF1 network element sending the first service flow through the first path according to the first interface configuration information can also be understood as the UPF1 network element updating the interface configuration information mapped to the first service flow to the first interface configuration information. This is explained uniformly here and will not be repeated below.

[0525] Optionally, in this embodiment, the UPF1 network element can send the first service flow through the first path according to the first interface configuration information. Simultaneously, the UPF1 network element can send the first service flow through the second path according to the initial interface configuration information. In other words, the UPF1 network element can copy the data packets of the first service flow (two copies in total) and send the first service flow simultaneously through the first and second paths. This embodiment does not specifically limit this.

[0526] This concludes the handover method provided in this application embodiment. The handover method provided in this application embodiment can complete the interface configuration for the second device before the handover process ends, enabling the second device to send the first service flow after receiving it, at the service flow transmission time. Therefore, this solution can satisfy deterministic transmission on the first path between the target gNB and the UPF1 network element in terminal device mobility scenarios. Furthermore, this solution can also satisfy deterministic transmission on the second path between the source gNB and the UPF1 network element.

[0527] The actions of the SMF network element in steps S2701 to S2712 above can be performed by... Figure 11 The processor 1101 in the communication device 1100 shown executes the application code stored in the memory 1103. The actions of the UPF1 network element in steps S2601 to S2612 can be performed by... Figure 11 The processor 1101 in the communication device 1100 shown calls the application code stored in the memory 1103 to execute the application code. This embodiment does not impose any limitations on this.

[0528] Optional, in Figure 27 In the scenarios corresponding to the described embodiments, this application embodiment can also provide a switching method, such as... Figure 28 As shown, the switching method includes the following steps:

[0529] S2801. When a terminal device determines that it needs to switch from a source gNB serving the terminal device to a target gNB, the target gNB learns during the handover preparation phase that the terminal device needs to switch to the target gNB, and the first service flow to be switched supports deterministic transmission.

[0530] S2802, the target gNB or the AN-TT corresponding to the target gNB sends a sixth indication message to the SMF network element, and correspondingly, the SMF network element receives the sixth indication message from the target gNB or the AN-TT corresponding to the target gNB. The sixth indication message indicates that the terminal device needs to switch to the target gNB, and that the first service flow to be switched supports deterministic transmission.

[0531] For a description of steps S2801 and S2802, please refer to [link / reference]. Figure 27 Steps S2701-S2702 in the embodiments described herein will not be repeated here.

[0532] Based on the processing time information of the UPF1 network element and the port information of the N3-TT corresponding to the UPF1 network element, the S2803 and SMF network elements determine the information of service flow group 2 and the information of the service flow group corresponding to the first service flow when it is transmitted on the forwarding path in the downlink scenario (hereinafter referred to as the information of service flow group 4). For relevant descriptions of the first path and the forwarding path, please refer to... Figure 14 In the aforementioned embodiment, information about service flow group 2 can be found by referring to... Figure 27 The embodiments described herein will not be repeated here.

[0533] It is understood that, in this embodiment of the application, since the UPF1 network element remains unchanged, the processing time information of the UPF1 network element and the N3-TT port information corresponding to the UPF1 network element required by the SMF network element to determine the information of service flow group 2 and service flow group 4 can be obtained by the SMF network element in the process before handover or in the handover preparation phase; therefore, they are not illustrated in the flowchart. Specifically, the relevant implementation for the SMF network element to obtain the processing time information of the UPF1 network element and the N3-TT port information corresponding to the UPF1 network element can be found in [reference needed]. Figure 14 The description of scenario 2 in the implementation of the first device obtaining the processing time information of the second device from the second device in the above embodiments will not be repeated here.

[0534] In this embodiment, the information of service flow group 4 includes the identifier of the first service flow (such as StreamID or MAC address), minimum offset 4, and maximum offset 4. The minimum offset 4 is the minimum offset of the time the UPF1 network element sends the first service flow through the forwarding path relative to the reference time; it can also be understood as the offset of the earliest transmission time of the first service flow transmitted through the forwarding path within the UPF1 network element relative to the reference time. The maximum offset 4 is the maximum offset of the time the UPF1 network element sends the first service flow through the forwarding path relative to the reference time; it can also be understood as the offset of the latest transmission time of the first service flow transmitted through the forwarding path within the UPF1 network element relative to the reference time.

[0535] For example, the minimum offset 4 can be determined with reference to the above formula (11) or formula (12); the maximum offset 4 can be determined with reference to any of the above formulas (13) to (16), which will not be repeated here. Among them, the second device in the above formulas (11) to (16) corresponds to the UPF1 network element in the embodiment of this application, and the third device corresponds to the target gNB or the AN-TT corresponding to the target gNB in ​​the embodiment of this application.

[0536] Optionally, in this embodiment, the information of service flow group 4 may further include one or more of the following parameters: TSN transmitter information and TSN receiver information corresponding to the first service flow, the priority (StreamRank) of the first service flow, the period (Interval) of the first service flow, the maximum number of frames that can be sent per unit time length (MaxFramesPerInterval), the maximum burst size, the UserToNetworkRequirements parameter, or jitter. The TSN transmitter information corresponding to the first service flow included in the information of service flow group 4 may, for example, be the N3-TT port information corresponding to the UPF1 network element, and the TSN receiver information corresponding to the first service flow included in the information of service flow group 4 may, for example, be the AN-TT port information corresponding to the target gNB. The descriptions of the other parameters can be found in the description of step S2703, and will not be repeated here.

[0537] It should be noted that the calculation method of the maximum latency requirement (UserToNetworkRequirements.MaxLatency) of the first service flow between the second and third devices in the UserToNetworkRequirements parameter of the above-mentioned service flow group 4 information is different from the calculation method of the maximum latency requirement (UserToNetworkRequirements.MaxLatency) of the first service flow between the second and third devices in the UserToNetworkRequirements parameter of the above-mentioned service flow group 2 information. The reason is that in this embodiment, a forwarding path is introduced between the UPF1 network element and the target gNB. Therefore, in this embodiment, the forwarding path latency needs to be introduced when calculating the maximum latency requirement of the first service flow between the second and third devices. In other words, in this embodiment, the maximum latency requirement of the first service flow transmitted between the UPF1 network element and the target gNB = the packet latency budget of the first service flow transmitted between the UPF1 network element and the source gNB + the transmission latency of the first service flow between the source gNB and the target gNB - the processing time of the first service flow in the UPF1 network element. Formula (19)

[0538] Alternatively, the maximum latency requirement for the first service flow transmission between the UPF1 network element and the target gNB = the packet latency budget for the first service flow transmission between the UPF1 network element and the source gNB + the transmission latency of the first service flow between the source gNB and the target gNB - the processing time of the first service flow at the target gNB - the processing time of the first service flow at the UPF1 network element. Formula (20)

[0539] Optionally, in this embodiment of the application, when there is a direct tunnel between the target gNB and the source gNB, the method by which the SMF network element obtains the transmission delay of the first service flow between the source gNB and the target gNB can refer to the method by which the SMF network element obtains the processing time information of the AN-TT corresponding to the target gNB, and will not be repeated here.

[0540] Optionally, in this embodiment of the application, when there is no direct tunnel between the target gNB and the source gNB, the calculation method for the transmission delay of the first service flow between the source gNB and the target gNB is relatively complex. Two calculation methods are provided below as examples:

[0541] For example, in a scenario where the terminal device switches over, the forwarding path between the UPF1 network element and the target gNB can be, for example, UPF1 network element -> UPF2 network element -> source gNB -> UPF2 network element -> target gNB. In this case, the transmission delay of the first service flow between the source gNB and the target gNB can be, for example, the processing time of the first service flow in the source gNB + the packet delay budget of the first service flow between the source gNB and the UPF2 network element + the packet delay budget of the first service flow between the UPF2 network element and the target gNB - the processing time of the first service flow in the UPF2 network element. Accordingly, combined with formula (19), the maximum latency requirement for the transmission of the first service flow between the UPF1 network element and the target gNB = the packet latency budget for the t...

Claims

1. A handover method, characterized by, The method comprises: The first device determines interface configuration information for a second device in the case that a first service flow is switched from a source access network device serving a terminal device to a target access network device serving the terminal device, the interface configuration information comprising information of a service flow sending time, the interface configuration information being used by the second device to send the first service flow at the service flow sending time after receiving the first service flow; if the first service flow is an uplink service flow, the second device is the target access network device or a converter corresponding to the target access network device; if the first service flow is a downlink service flow, the second device is a first user plane network element; The first device sends the interface configuration information to the second device; After the first device learns from the second device that interface configuration associated with the interface configuration information is completed, the first device notifies the target access network device or the source access network device to execute a switching execution process.

2. The method of claim 1, wherein, The interface configuration information comprises first interface configuration information, the first interface configuration information being used by the second device to send the first service flow through a first path at a first service flow sending time, wherein the first path is a path from the second device to a third device, if the first service flow is an uplink service flow, the third device is a first user plane network element; if the first service flow is a downlink service flow, the third device is the target access network device or a converter corresponding to the target access network device.

3. The method of claim 2, wherein, The first interface configuration information comprises information of the first service flow sending time.

4. The method of claim 3, wherein, The information of the first service flow sending time comprises at least one of the first service flow sending time, an offset of the first service flow sending time relative to a reference time, or a first gating scheduling parameter, the first gating scheduling parameter being used by the second device to send the first service flow through the first path at the first service flow sending time.

5. The method according to any one of claims 2-4, characterized in that, The method further comprises: The first device receives first indication information, the first indication information being used to indicate that data transmission of the first service flow on a second path is completed, the second path being a path from the first user plane network element to the source access network device; The first device sends second indication information to a centralized network configuration network element, the second indication information being used to indicate information of deleting a service flow group corresponding to transmission of the first service flow on the second path.

6. The method according to any one of claims 1 to 4, characterized in that, The first service flow is a downlink service flow; the interface configuration information comprises second interface configuration information, the second interface configuration information being used by the second device to send the first service flow to the target access network device through a forwarding path at a second service flow sending time.

7. The method of claim 6, wherein, The second interface configuration information comprises information of the second service flow sending time.

8. The method of claim 7, wherein, The information of the second service flow sending time comprises at least one of the second service flow sending time, an offset of the second service flow sending time relative to a reference time, or a second gating scheduling parameter used by the second device to send the first service flow through the forwarding path at the second service flow sending time.

9. The method of claim 6, wherein, The method further comprises: The first device receives third indication information, the third indication information being used to indicate that data transmission of the first service flow on the forwarding path is completed; The first device sends fourth indication information to a centralized network configuration network element, the fourth indication information being used to indicate that information of a service flow group corresponding to transmission of the first service flow on the forwarding path is deleted; And / or, the first device sends fifth indication information to the first user plane network element, the fifth indication information being used to indicate that the second interface configuration information is deleted.

10. The method of claim 6, wherein, The forwarding path comprises a path from the first user plane network element to the source access network device and a path from the source access network device to the target access network device. Or, the forwarding path comprises a path from the first user plane network element to a second user plane network element, a path from the second user plane network element to the source access network device, a path from the source access network device to the second user plane network element, and a path from the second user plane network element to the target access network device.

11. A handover method, characterized by, The method comprises: A second device receives interface configuration information of the second device in a case where a first service flow is switched from a source access network device serving a terminal device to a target access network device serving the terminal device, the interface configuration information comprising information of service flow sending time; wherein if the first service flow is an uplink service flow, the second device is the target access network device or a converter corresponding to the target access network device; if the first service flow is a downlink service flow, the second device is a first user plane network element; The second device performs interface configuration according to the interface configuration information, the interface configuration being used for the second device to send the first service flow at a service flow sending time after receiving the first service flow; After the second device performs the interface configuration, the second device notifies a first device that the interface configuration is completed.

12. The method of claim 11, wherein, The second device is the target access network device; the method further comprises: After the second device notifies the first device that the interface configuration is completed, the second device executes a switching execution process according to notification of the first device.

13. The method according to claim 11 or 12, characterized in that, The interface configuration information comprises first interface configuration information, the first interface configuration information being used for the second device to send the first service flow through a first path at a first service flow sending time, wherein the first path is a path from the second device to a third device, if the first service flow is an uplink service flow, the third device is a first user plane network element; if the first service flow is a downlink service flow, the third device is the target access network device or a converter corresponding to the target access network device.

14. The method of claim 13, wherein, The first interface configuration information comprises information of the first service flow sending time.

15. The method of claim 14, wherein, The information of the first service flow sending time comprises at least one of the first service flow sending time, an offset of the first service flow sending time relative to a reference time, or a first gating scheduling parameter used by the second device to send the first service flow through the first path at the first service flow sending time.

16. The method of claim 13, wherein, The first service flow is a downlink service flow; and the second device performs interface configuration according to the interface configuration information, comprising: The second device updates the locally stored interface configuration information, wherein the updated interface configuration information comprises the first interface configuration information, and the first interface configuration information is used to replace initial interface configuration information, and the initial interface configuration information is used by the second device to send the first service flow through a second path at an initial service flow sending time, and the second path is a path from the first user plane network element to the source access network device.

17. The method of claim 13, wherein, The first service flow is a downlink service flow; and the second device performs interface configuration according to the interface configuration information, comprising: The second device updates the locally stored interface configuration information, wherein the updated interface configuration information comprises the first interface configuration information and initial interface configuration information, and the initial interface configuration information is used by the second device to send the first service flow through a second path at an initial service flow sending time, and the second path is a path from the first user plane network element to the source access network device.

18. The method of claim 17, wherein, The updated interface configuration information further comprises a first identifier, and the first identifier is used to indicate that the first interface configuration information is interface configuration information corresponding to the first path.

19. The method of claim 17 or 18, wherein, The method further comprises: After the second device acquires the tunnel information of the target access network device, the second device deletes the initial interface configuration information; Or, after the second device sends the data packet corresponding to the first service flow with an end marker to the source access network device, the second device deletes the initial interface configuration information.

20. The method according to any one of claims 14-18, characterized by, The method further comprises: After the second device sends the data packet corresponding to the first service flow with an end marker to the source access network device, the second device sends the first service flow through the first path according to the first interface configuration information.

21. The method of any one of claims 16-18, wherein, The initial interface configuration information comprises information of the initial service flow sending time.

22. The method of claim 21, wherein, The information of the initial service flow sending time comprises at least one of the initial service flow sending time, an offset of the initial service flow sending time relative to a reference time, or an initial gating scheduling parameter used by the second device to send the first service flow through the second path at the initial service flow sending time.

23. The method of any one of claims 16-18, wherein, The first service flow is a downlink service flow; and the interface configuration information further comprises second interface configuration information, and the second interface configuration information is used by the second device to send the first service flow to the target access network device through a forwarding path at a second service flow sending time. The updated interface configuration information further comprises the second interface configuration information.

24. The method of claim 23, wherein, The updated interface configuration information further comprises a second identifier, and the second identifier is used to indicate that the second interface configuration information is the interface configuration information corresponding to the forwarding path.

25. The method of claim 23, wherein, The method further comprises: The second device receives fifth indication information from the first device, and deletes the second interface configuration information according to the fifth indication information. Or, after the second device sends the data packet with the end marker corresponding to the first service flow to the source access network device, the second device deletes the second interface configuration information.

26. The method of claim 23, wherein, The method further comprises: After the second device obtains the tunnel information of the target access network device, the second device sends the first service flow through the forwarding path according to the second interface configuration information.

27. The method of claim 23, wherein, The second interface configuration information comprises information of the second service flow sending time.

28. The method of claim 27, wherein, The information of the second service flow sending time comprises at least one of the second service flow sending time, an offset of the second service flow sending time relative to a reference time, or a second gating scheduling parameter used by the second device to send the first service flow through the forwarding path at the second service flow sending time.

29. The method of claim 23, wherein, The forwarding path comprises a path from the first user plane network element to the source access network device, and a path from the source access network device to the target access network device. Or, the forwarding path comprises a path from the first user plane network element to a second user plane network element, a path from the second user plane network element to the source access network device, a path from the source access network device to the second user plane network element, and a path from the second user plane network element to the target access network device.

30. A communications device, characterized by The apparatus comprises a processor and an interface circuit, the interface circuit is used to receive signals from other communication apparatuses outside the communication apparatus and transmit the signals to the processor or send signals from the processor to other communication apparatuses outside the communication apparatus, and the processor is used to realize the method according to any one of claims 1 to 10 by logic circuit or code instruction execution.

31. A communications device, characterized by The apparatus comprises a processor and an interface circuit, the interface circuit is used to receive signals from other communication apparatuses outside the communication apparatus and transmit the signals to the processor or send signals from the processor to other communication apparatuses outside the communication apparatus, and the processor is used to realize the method according to any one of claims 11 to 29 by logic circuit or code instruction execution.

32. A computer program product, characterised in that, The computer program product comprises instructions, when the instructions are executed, the computer executes the method according to any one of claims 1 to 29.

33. A computer-readable storage medium, comprising: The computer readable storage medium stores instructions, when the instructions are executed on the computer, the processor executes the method according to any one of claims 1 to 29.

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