Continuity of service implementation method, session management function entity, control device, service continuity implementation system, and, computer readable storage media

Abstract

The modalities of this application provide a service continuity implementation method, a device, and a service continuity implementation system to ensure service continuity in a transfer process.The method includes: selecting, by a session management role entity, a target user plane role entity to serve a terminal; sending, by the session management role entity, a first message to a control device; receiving, by the session management role entity, information indicating a first application server as from the control device; and sending, by the session management role entity, a first routing rule to the target user plane role entity based on the information indicating the first as, wherein the first routing rule includes data whose destination address is an address of the first as sent to the first as.

Description

1 / 97 Service Continuity Implementation Method, Session Management Function Entity, Control Device, Service Continuity Implementation System, and Computer-Readable Storage Medium TECHNICAL FIELD

[001] This application relates to the field of communication technologies and, in particular, to a method for implementing continuity of service, a device, and a system for implementing continuity of service. FUNDAMENTALS

[002] To meet the challenges of wireless broadband technologies and maintain the cutting-edge advantages of third-generation partnership project (3GPP) networks, the 3GPP standards organization formulated a network architecture for a next-generation mobile communications system by the end of 2016, which is called the 5th generation (5G) network architecture.

[003] In 5G network architecture, an ultra-reliable low-latency communication (URLLC) scenario is defined, and it mainly includes services such as self-driving and industrial automation that require low-latency and high-reliability connectivity. For example, the existing 5G technical standard (TS) 22186 specifies that, in a remote driving scenario, end-to-end latency between a terminal and a server must always be less than 5 ms. To meet an end-to-end latency requirement, an application server (AS) needs to be deployed locally. Furthermore, if the Petition 870240061722, dated 07 / 22 / 2024, page 17 / 228 2 / 97 terminals move at high speed, and the handover of a user plane function (UPF) entity and the transfer of an AS can occur. However, continuity of service must be guaranteed during the handover process to meet end-to-end latency requirements at all times.

[004] Currently, a viable solution for deploying an application server locally is the use of an uplink classifier (ULCL) mechanism. In a ULCL scenario, for a packet data unit (PDU) session, there can be a plurality of PDU entities, and local offloading can be implemented using a ULCL. In this way, an application server that provides an ultra-low latency service or a high-value service can be deployed locally. In this deployment, a path between the endpoint and the AS is shorter, so the end-to-end latency can meet an ultra-low latency requirement.

[005] However, currently, there is no related solution to ensure continuity of service in the transfer process. SUMMARY

[006] The modalities of this application provide a service continuity implementation method, a device, and a service continuity implementation system, to ensure service continuity in a transfer process.

[007] According to a first aspect, a service continuity implementation method is provided. The method includes: selecting, by a function entity of Petition 870240061722, dated 07 / 22 / 2024, page 18 / 228 3 / 97 Session management, a target user plane role entity to serve a terminal; send, by the session management role entity, a first message to a control device; receive, by the session management role entity, information indicating a first application server AS from the control device; and send, by the session management role entity, a first routing rule to the target user plane role entity based on the information indicating the first AS, where the first routing rule includes data whose destination address is an address of the first AS is sent to the first AS.Based on this solution, in one aspect, after the session management role entity selects the target user plane role entity to serve the endpoint, the session management role entity can receive the first AS's indication information and send the first routing rule to the target user plane role entity based on the first AS's indication information, so that the target user plane role entity can transmit service data according to the first routing rule. Therefore, continuity of service can be guaranteed in a user plane role entity transfer process. In another aspect, the first routing rule dictates that data whose destination address is the address of the first AS is sent to the first AS.This prevents the target user plane function entity from routing data that should be sent to the first AS first to a remote data network and then to the first AS. Therefore, a path a. Petition 870240061722, dated 07 / 22 / 2024, page 19 / 228 4 / 97 from the terminal to the first AS is shorter, and the latency is controllable.

[008] Optionally, after a session management role entity selects a target user plane role entity to serve an endpoint, and before the session management role entity sends a first routing rule to the target user plane role entity, the method further includes: sending a second routing rule to the target user plane role entity, wherein the second routing rule includes data whose destination address is the address of a second AS is sent to a source user plane role entity, the second AS is an AS currently serving the endpoint, and the source user plane role entity is a user plane role entity communicatively connected to the second AS.Based on this solution, when a user plane role entity transfer occurs, the target user plane role entity after the transfer includes a routing rule for service data whose destination address is the current AS address. Therefore, service continuity can be maintained during the user plane role entity transfer.

[009] Optionally, after a session management role entity selects a target user plane role entity to serve a terminal, the method further includes: sending, by the session management role entity, initial path information to the target user plane role entity; and sending, Petition 870240061722, dated 07 / 22 / 2024, page 20 / 228 5 / 97 by the session management function entity, second path information for the source user plane function entity, where the first path information and the second path information are used to establish a routing path between the target user plane function entity and the source user plane function entity. Based on this solution, the routing path between the target user plane function entity and the source user plane function entity can be established.

[0010] Optionally, after a session management role entity selects a target user plane role entity to serve an endpoint, the method further includes: sending, by the session management role entity, a third routing rule to the target user plane role entity, where the third routing rule includes data whose destination address is an address of a first data network is sent to a remote user plane role entity, and the remote user plane role entity is a user plane role entity communicatively connected to the first data network. Based on this solution, when a user plane role entity transfer occurs, the target user plane role entity after the transfer includes a routing rule for service data whose destination address is the address of the first data network.Therefore, continuity of service can be maintained during the transfer of the user plan function entity.

[0011] Optionally, after selection, by a Petition 870240061722, dated 07 / 22 / 2024, page 21 / 228 6 / 97 session management function entity, from a target user plane function entity to serve a terminal, the method further includes: sending, by the session management function entity, third path information to the target user plane function entity; and sending, by the session management function entity, fourth path information to the remote user plane function entity, where the third path information and the fourth path information are used to establish a forwarding path between the target user plane function entity and the remote user plane function entity. Based on this solution, the forwarding path between the target user plane function entity and the remote user plane function entity can be established.

[0012] Optionally, after the session management role entity sends a first routing rule to the target user plane role entity, the method also includes: sending a second message to the target user plane role entity, where the second message is used to request the deletion of the second routing rule. In other words, when a network-side path is ready, a routing rule corresponding to an original service in the target user plane role entity can be released.

[0013] Optionally, after the session management role entity sends a first routing rule to the target user plane role entity, the method also includes: sending, by the role entity Petition 870240061722, dated 07 / 22 / 2024, page 22 / 228 In session management (7 / 97), a third message is sent to the target user plane role entity, where the third message is used to request the deletion of the first path information. In other words, if the network-side path is ready, path information corresponding to an original service in the target user plane role entity can be released.

[0014] Optionally, after the session management role entity sends a first routing rule to the target user plane role entity, the method also includes: sending, by the session management role entity, a fourth message to the source user plane role entity, where the fourth message is used to request the deletion of user plane information, corresponding to the endpoint, in the source user plane role entity, and the user plane information includes the second path information. In other words, if the network-side path is ready, the user plane information, corresponding to the endpoint, in the source user plane role entity can be released.

[0015] Optionally, before selecting, by a session management role entity, a target user plane role entity to serve a terminal, the method further includes: sending, by the session management role entity, fifth path information to a target base station; and sending, by the session management role entity, sixth path information to the source user plane role entity, where the fifth path information and the sixth path information Petition 870240061722, dated 07 / 22 / 2024, page 23 / 228 8 / 97 are used to establish a routing path between the target base station and the source user plane function entity. The source user plane function entity is a user plane function entity currently establishing a first packet data unit (PDU) session with the terminal, and the target base station is a base station currently communicatively connected to the target user plane function entity. Based on this solution, the routing path between the target base station and the source user plane function entity can be pre-established, so that when a user plane function entity transfer occurs, continuity of an existing service can be maintained.

[0016] Optionally, the selection, by a session management role entity, of a target user plane role entity to serve an endpoint includes: sending, by the session management role entity, a fifth message to the endpoint, where the fifth message is used to request the establishment of a second PDU session; and selecting, by the session management role entity in a process of establishing the second PDU session, the target user plane role entity to serve the endpoint. Based on this solution, the session management role entity can select the target user plane role entity to serve the endpoint.

[0017] Optionally, after the session management role entity sends a first routing rule to the target user plane role entity, the method also includes: sending, by the role entity Petition 870240061722, dated 07 / 22 / 2024, page 24 / 228 In session management (9 / 97), a sixth message is sent to the endpoint, where the sixth message is used to request the release of the first PDU session. In other words, when a network-side path for a new PDU session is ready, an old PDU session resource can be released.

[0018] Optionally, after the session management role entity sends a first routing rule to the target user plane role entity, the method also includes: sending, by the session management role entity, a seventh message to the control device, where the seventh message is used to request the switching of the terminal from the second AS to the first AS, and the second AS is the AS that is currently serving the terminal. Based on this solution, the terminal can be switched from the second AS to the first AS.

[0019] Optionally, after the session management function entity sends a seventh message to the control device, the method also includes: receiving an eighth message from the control device by the session management function entity, where the eighth message is used to indicate that the terminal has been switched from the second AS to the first AS. In this way, the control device can discover, in a timely manner, whether an AS transfer has been completed, and can also perform a subsequent operation in a timely manner.

[0020] Optionally, the first message includes at least one piece of location information for the target user plane function entity or location information. Petition 870240061722, dated 07 / 22 / 2024, page 25 / 228 10 / 97 of the terminal, and at least one of the location information of the target user plane function entity or the terminal location information is used to determine which AS to serve the terminal is the first AS. In this way, after receiving the first message, the control device can determine, based on the first message, the AS to serve the terminal.

[0021] Optionally, the information indicating the first AS includes location information of the first AS, identifier information of the first AS, information indicating that the AS does not change, or similar. This is not specifically limited in this embodiment of this application.

[0022] According to a second aspect, a service continuity implementation method is provided. The method includes: receiving, by a control device, a first message from a session management role entity; and sending, by the control device, information indicating a first application server AS to the session management role entity, where the information indicating the first AS is used to instruct the session management role entity to send a first routing rule to a target user plane role entity, and the first routing rule includes the data whose destination address is an address of the first AS is sent to the first AS.Based on this solution, in one aspect, after the control device sends the first AS indication information to the session management function entity, the session management function entity can receive the first AS indication information and send the first one. Petition 870240061722, dated 07 / 22 / 2024, p. 26 / 228 The 11 / 97 routing rule for the target user plane function entity is based on the first AS's indication information, so that the target user plane function entity can transmit service data according to the first routing rule. Therefore, continuity of service can be guaranteed in a user plane function entity transfer process. In another aspect, the first routing rule dictates that data whose destination address is the first AS's address is sent to the first AS. This prevents the target user plane function entity from routing data to the first AS's address first to a remote data network and then to the first AS. Therefore, a path from a terminal to the first AS is shorter, and latency is controllable.

[0023] Optionally, the first message includes at least one piece of target user plane function entity location information or terminal location information, and at least one piece of target user plane function entity location information or terminal location information is used to determine which AS to serve the terminal is the first AS. In this way, after receiving the first message, the control device can determine, based on the first message, the AS to serve the terminal.

[0024] Optionally, after the control device sends the information indicating a first AS to the session management function entity, the method also includes: receiving, by the control device, a seventh message from the function entity of Petition 870240061722, dated 07 / 22 / 2024, page 27 / 228 In 12 / 97 session management, the seventh message is used to instruct the terminal to be switched from a second AS to the first AS, and the second AS is currently serving the terminal; and the control device switches the terminal from the second AS to the first AS based on the seventh message. Based on this solution, the terminal can be switched from the second AS to the first AS.

[0025] Optionally, the control device includes a vehicle communication control function entity for all V2X.

[0026] According to a third aspect, a session management function entity is provided. The session management function entity has the function of implementing the method according to the first aspect. The function can be implemented using hardware or it can be implemented using hardware running the corresponding software. The hardware or software includes one or more modules corresponding to the function.

[0027] According to a fourth aspect, a session management function entity is provided, including a processor, memory, a bus, and a communications interface. The memory is configured to store a computer executable instruction. The processor is connected to the memory using the bus. When the session management function entity is executed, the processor executes the computer executable instruction stored in memory, so that the session management function entity performs the continuity of service implementation method according to any of the design ways of the first aspect. Petition 870240061722, dated 07 / 22 / 2024, page 28 / 228 13 / 97

[0028] According to a fifth aspect, an embodiment of this application provides a computer-readable storage medium. The computer-readable storage medium stores an instruction. When the instruction is executed on a computer, the computer is enabled to perform the continuity of service implementation method according to any of the design modes of the first aspect.

[0029] According to a sixth aspect, an embodiment of this application provides a computer program product including an instruction. When the computer program product is run on a computer, it is enabled to perform the service continuity implementation method according to any of the design modes of the first aspect.

[0030] For technical effects brought about by any of the design methods from the third aspect to the sixth aspect, see the technical effects brought about by different design methods from the first aspect. The details are not described here again.

[0031] According to a seventh aspect, a control device is provided. The control device has the function of implementing the method according to the second aspect. The function can be implemented using hardware or it can be implemented using hardware running the corresponding software. The hardware or software includes one or more modules corresponding to the function.

[0032] According to an eighth aspect, a control device is provided, including a processor, memory, a bus, and a communications interface. A Petition 870240061722, dated 07 / 22 / 2024, page 29 / 228 14 / 97 memory is configured to store a computer-executable instruction. The processor is connected to the memory using the bus. When the control device is executed, the processor executes the computer-executable instructions stored in memory, so the control device performs the continuity of service implementation method according to either of the second aspect design methods.

[0033] According to a ninth aspect, a computer-readable storage medium is provided. The computer-readable storage medium stores an instruction. When the instruction is executed on a computer, the computer is enabled to perform the continuity of service implementation method according to any of the design ways of the second aspect.

[0034] According to a tenth aspect, a computer program product is provided including an instruction. When the computer program product is executed on a computer, it is enabled to perform the service continuity implementation method according to any of the design ways of the second aspect.

[0035] For technical effects brought about by any of the design methods from the seventh aspect to the tenth aspect, see the technical effects brought about by different design methods from the second aspect. The details are not described here again.

[0036] According to an eleventh aspect, a method for implementing continuity of service is provided. The method includes: selecting, by a session management role entity, a role entity of Petition 870240061722, dated 07 / 22 / 2024, page 30 / 228 15 / 97 target user plane to serve a terminal; send, by the session management function entity, a first message to a control device and receive, by the control device, the first message from the session management function entity; send, by the control device, information indicating a first application server AS to the session management function entity, and receive, by the session management function entity, information indicating the first AS from the control device; and send, by the session management function entity, a first routing rule to the target user plane function entity based on the information indicating the first AS, where the first routing rule includes the data whose destination address is an address of the first AS sent to the first AS.

[0037] According to a twelfth aspect, a service continuity implementation system is provided, including the control device according to any of the previous aspects and the session management function entity according to any of the previous aspects.

[0038] These aspects or other aspects of this request may be clearer and easier to understand in the descriptions in the following modalities. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a first schematic architectural diagram of a service continuity implementation system according to one embodiment of this request; Petition 870240061722, dated 07 / 22 / 2024, page 31 / 228 16 / 97 Figure 2 is a second schematic architectural diagram of a service continuity implementation system according to one modality of this request; Figure 3 is a third schematic architectural diagram of a service continuity implementation system according to one modality of this request; Figure 4 is a schematic diagram of a hardware structure for a communications device according to one embodiment of this application; Figure 5 is a first schematic flowchart of a service continuity implementation method according to one modality of this request; Figure 6A and Figure 6B are a second schematic flowchart of a service continuity implementation method according to one modality of this request; Figure 7A and Figure 7B are a third schematic flowchart of a service continuity implementation method according to one modality of this request; Figure 8A and Figure 8B are a fourth schematic flowchart of a service continuity implementation method according to one modality of this request; Figure 9A and Figure 9B are a fifth schematic flowchart of a service continuity implementation method according to one modality of this request; Figure 10 is a first schematic structural diagram of a session management function entity according to one modality of this request; Figure 11 is a second schematic structural diagram of a session management function entity according to a modality of this request; Petition 870240061722, dated 07 / 22 / 2024, page 32 / 228 17 / 97 Figure 12 is a first schematic structural diagram of a control device according to an embodiment of this application; and Figure 13 is a second schematic structural diagram of a control device according to an embodiment of this application. DESCRIPTION OF THE MODALITIES

[0040] To facilitate understanding of technical solutions in the modalities of this application, the following first briefly describes the technologies related to this application. 1. Tunnel:

[0041] The tunnels in the embodiments of this application include a next-generation (N-N) interface 3 tunnel (N3 for short) and an interface N 9 tunnel (N9 for short). The N3 tunnel is a tunnel between an access device (e.g., a base station) and a UPF entity. The N9 tunnel is a tunnel between UPF entities. Generally, the N3 tunnel is a tunnel at a session granularity, and the N9 tunnel can be a tunnel at a session granularity, or a tunnel at a device granularity.

[0042] Tunneling at a session granularity means that tunnel resources are established for a PDU session, and the tunnel is used for only one PDU session. A tunnel at a session granularity includes only one routing rule, and only that routing rule can match the tunnel for data forwarding. Furthermore, a tunnel lifecycle at a session granularity is a PDU session lifecycle. To be Petition 870240061722, dated 07 / 22 / 2024, page 33 / 228 Specifically, in the 18 / 97 model, when a PDU session disappears or is released, the tunnel at that session granularity also needs to be released.

[0043] A tunnel at a device granularity is a tunnel resource established for one or more PDU sessions, and the tunnel can be used for one or more PDU sessions. A tunnel at a device granularity can include one or more routing rules, and each of the one or more routing rules can correspond to the tunnel for data forwarding. Furthermore, a tunnel lifecycle at a device granularity is a lifecycle of a plurality of PDU sessions corresponding to the tunnel.To be specific, assuming that the tunnel at a device granularity corresponds to M PDU sessions, when the first M - 1 PDU sessions in the plurality of PDU sessions corresponding to the tunnel disappear or are released, only routing rules corresponding to the corresponding PDU sessions are released; and the tunnel at a device granularity can only be released when an M-th PDU session in the plurality of PDU sessions corresponding to the tunnel disappears or is released. Certainly, when the M-th PDU session in the plurality of PDU sessions corresponding to the tunnel disappears or is released, the tunnel at a device granularity can alternatively be retained, so that the tunnel does not need to be re-established later. This is not specifically limited in the modalities of this application. 2. Routing rule:

[0044] A routing rule in the modalities of this request is specifically a rule for routing data from Petition 870240061722, dated 07 / 22 / 2024, p. 34 / 228 19 / 97 service for a next-hop device.

[0045] For example, a first routing rule on a target UPF entity in the following modes includes data whose destination address is the address of a first AS being sent to the first AS. This specifically means that a next-hop device for service data whose destination address is the address of the first AS is the first AS.

[0046] Alternatively, for example, a second routing rule on a target UPF entity in the following modes includes data whose destination address is an AS 1 address being sent to a source UPF entity. This specifically means that a next-hop device for service data whose destination address is the AS 1 address is the source UPF entity.

[0047] Alternatively, for example, a third routing rule in a target UPF entity includes data whose destination address is an anchor data network (A-DN) address or data whose destination address is the default is sent to an A-UPF entity. This specifically means that a next-hop device for service data whose destination address is the A-DN address or service data whose destination address is the default is the A-UPF entity.

[0048] Alternatively, for example, a fourth routing rule in a source UPF entity includes data whose destination address is an endpoint address being sent to a target UPF entity. This specifically means that a next device Petition 870240061722, dated 07 / 22 / 2024, p. 35 / 228 20 / 97 jump to service data whose destination address is the terminal address are the target UPF entity.

[0049] Alternatively, for example, a fifth routing rule in a source UPF entity includes data whose destination address is a terminal address being sent to a target base station. This specifically means that a next-hop device for service data whose destination address is the terminal address is the target base station. 3. Route information:

[0050] The path information in the embodiments of this application includes at least one piece of tunnel uplink information from A or tunnel downlink information from B, and is used to establish a tunnel between A and B. Tunnel uplink information from A may include a tunnel endpoint address on the A side, an address of A, and the like. Tunnel downlink information from B includes a tunnel endpoint address on the B side, an address of B, and the like. This is not specifically limited in the embodiments of this application.

[0051] It should be noted that the route information in the modes of this request may or may not include a routing rule. The following modes are described using an example in which the route information does not include a routing rule. A general description is provided here, and the details are not described again below.

[0052] The following describes the technical solutions in the embodiments of this application with reference to the drawings attached to the embodiments of this application. In the descriptions of this application, Petition 870240061722, dated 07 / 22 / 2024, p. 36 / 228 21 / 97 / means "or" unless otherwise specified. For example, A / B may represent A or B. In this specification, "and / or" describes only an association relation to describe associated objects and represents that three relations may exist. For example, A and / or B may represent the following three cases: Only A exists, A and B exist, and only B exists. Furthermore, in the descriptions of this application, a plurality of means two or more of two unless otherwise specified. Additionally, to clearly describe the technical solutions in the embodiments of this application, terms such as "first" and "second" are used in the embodiments of this application to distinguish between the same items or similar items that have basically the same functions or objectives. A person skilled in the art can understand that terms such as "first" and "second" do not limit a quantity or a sequence of execution, and that terms such as "first" and "second" do not indicate a definite difference.For example, a first AS and a second AS in the modalities of this request may be the same AS or they may be different ASs. This is not specifically limited in the modalities of this request.

[0053] A network architecture and service scenario described in the embodiments of this application are intended to describe technical solutions in the embodiments of this application more clearly and do not constitute a limitation of the technical solutions provided in the embodiments of this application. A person skilled in the art may know that, with the evolution of the network architecture and the emergence of a new service scenario, the technical solutions provided in the embodiments of this application are also applicable to problems Petition 870240061722, dated 07 / 22 / 2024, p. 37 / 228 22 / 97 similar technicians.

[0054] Figure 1 is a schematic architectural diagram of a service continuity implementation system 10 according to one embodiment of this application. The service continuity implementation system 10 includes a session management role entity 101 and a control device 102, and may further include a plurality of user plane role entities. For example, the plurality of user plane role entities may include a target user plane role entity 103 and a source user plane role entity 104.

[0055] In an initial state, session management role entity 101 communicates with source user plane role entity 104.

[0056] After a terminal moves, the session management role entity 101 is configured to: select the target user plane role entity 103 to serve the terminal, and send an initial message to the control device 102.

[0057] Control device 102 is configured to: receive the first message from session management function entity 101, and send information indicating a first AS to session management function entity 101.

[0058] Session management function entity 101 is further configured to: receive the first AS indication information from the control device 102, and send a first routing rule to the target user plane function entity 103 based on the Petition 870240061722, dated 07 / 22 / 2024, page 38 / 228 23 / 97 information indicating the first AS, where the first routing rule includes data whose destination address is an address of the first AS is sent to the first AS.

[0059] Target user plane role entity 103 is configured to: receive the first routing rule from session management role entity 101, and transmit service data according to the first routing rule after a PDU session is established.

[0060] Optionally, the session management function entity 101 and the control device 102 in Figure 1 may communicate directly with each other, or may communicate via routing through another network device. This is not specifically limited in this embodiment of this application.

[0061] Optionally, the session management role entity 101 and the target user plane role entity 103 in Figure 1 can communicate directly with each other, or they can communicate via routing through another network device. This is not specifically limited in this embodiment of this application.

[0062] According to the service continuity system provided in this modality of this request, in one aspect, after the session management role entity selects the target user plane role entity to serve the endpoint, the session management role entity can receive the first AS indication information, and send the first routing rule to the target user plane role entity based on the first AS indication information, of Petition 870240061722, dated 07 / 22 / 2024, page 39 / 228 24 / 97 mode: The target user plane function entity can transmit service data according to the first routing rule. Therefore, continuity of service can be guaranteed in a user plane function entity transfer process. In another aspect, the first routing rule dictates that data whose destination address is the address of the first AS is sent to the first AS. This prevents the target user plane function entity from routing data that should be sent to the first AS address first to a remote data network (DN) and then to the first AS. Therefore, a path from the endpoint to the first AS is shorter, and latency is controllable.

[0063] Optionally, the service continuity implementation system 10 can be applied to a future 5G network and to another future network. This is not specifically limited in this embodiment of this application. The following provides two typical scenarios in which the service continuity implementation system 10 is applied to an existing 5G network. Scenario 1:

[0064] If the service continuity implementation system 10 is applied to the current 5G network, a possible applicable architecture is a ULCL architecture shown in Figure 2. In a ULCL scenario, there can be a plurality of UPF entities for a PDU session, and local offloading can be implemented using a ULCL. The plurality of UPF entities includes at least one local UPF entity and one remote UPF entity. The at least one local UPF entity can include, for example, a local UPF entity 1, a local UPF entity 2, Petition 870240061722, dated 07 / 22 / 2024, p. 40 / 228 25 / 97 ...and a local UPF entity n. Specifically, the session management function entity 101 in Figure 1 can be a session management function (SMF) entity in the ULCL architecture, the control device 102 in Figure 1 can be an AS controller in the ULCL architecture, the target user plane function entity in Figure 1 can be any UPF entity in the ULCL architecture, for example, local UPF entity 1, and the source user plane function entity in Figure 1 can be any UPF entity other than local UPF entity 1 in the ULCL architecture, for example, local UPF entity 2. Furthermore, as shown in Figure 2, the ULCL architecture can also include a terminal, an access device, an access and mobility management function (AMF), the ULCL, and a plurality of data networks (DN).A plurality of DNs includes a remote DN and a plurality of local DNs. The plurality of local DNs may include, for example, a DN 1, a DN 2, ... and a DN n.

[0065] The terminal communicates with the AMF entity using a next-generation (N) network interface 1 (N1 for short), and communicates with the ULCL using the access device. The access device communicates with the AMF entity using an N2 interface (N2 for short) and communicates with the ULCL using an N3 interface (N3 for short). The AMF entity communicates with the SMF entity using an N11 interface (N11 for short). The SMF entity communicates with the UPF entities (including the remote UPF entity and the UPF entity). Petition 870240061722, dated 07 / 22 / 2024, p. 41 / 228 26 / 97 local) and the ULCL using an N4 interface (N4 for short). The ULCL communicates with the UPF entities (including the remote UPF entity and the local UPF entity) using an N9 interface (N9 for short). The UPF entities (including the remote UPF entity and the local UPF entity) communicate with the DNs (including the remote DN and the local DN) using an N6 interface (N6 for short).

[0066] Optionally, in this embodiment of this request, the local UPF entity and the ULCL can be deployed together or separately. This is not specifically limited in this embodiment of this request. When the local UPF entity and the ULCL are deployed separately, the ULCL can be deployed using the UPF entity. A general description is provided here, and the details are not described again below.

[0067] Optionally, in this embodiment of this request, the local UPF entity is a local service anchor. A local AS is deployed in a DN communicatively connected to the local UPF entity, and the terminal can access the local AS using the local UPF entity.

[0068] It should be noted that a communication connection in this mode of this application may be a direct connection, or it may be a connection using another network device. A general description is provided here, and the details are not described again below.

[0069] Optionally, in this embodiment of this request, the remote UPF entity is an internet protocol (IP) anchor. An IP address remains unchanged if the UPF entity remains unchanged. A remote AS can be deployed on a connected DN. Petition 870240061722, dated 07 / 22 / 2024, page 42 / 228 27 / 97 communicatively to the remote UPF entity, and the terminal can access the remote AS using the remote UPF entity. Certainly, the terminal can communicate with another terminal using the DN connected communicatively to the remote UPF entity. This is not specifically limited in this embodiment of this application.

[0070] In Figure 2, for uplink data, the ULCL forwards, according to an offloading rule delivered by the SMF entity, a local service to the local UPF entity and a non-local service to the remote UPF entity.

[0071] In this scenario, for a terminal using a URLLC service, during a terminal movement process, the remote UPF entity remains unchanged and therefore the IP address remains unchanged. However, to ensure a shorter path between the terminal and an AS, it may be necessary to perform a local UPF entity transfer and an AS transfer. The AS controller maintains AS topology information and can perform AS selection or re-selection based on the local UPF entity location information and / or the terminal location information. Therefore, when a local UPF entity transfer needs to be performed, the SMF entity needs to interact with the AS controller to implement AS re-selection in order to implement the shortest path between the terminal and the AS.

[0072] It should be noted that Figure 2 shows an example where different local UPF entities communicate with ASs in different DNs. Certainly, alternatively, the different local UPF entities Petition 870240061722, dated 07 / 22 / 2024, p. 43 / 228 28 / 97 can communicate with an AS on the same DN. In other words, after the transfer of the local UPF entity, the AS transfer may not occur. This is not specifically limited in this modality of this request. Scenario 2:

[0073] Optionally, if the service continuity implementation system 10 is applied to the current 5G network, another possible applicable architecture is shown in Figure 3. The network architecture shown in Figure 3 corresponds to a single anchor PDU session scenario. To be specific, a PDU session corresponds to a UPF entity. Specifically, the session management function entity 101 in Figure 1 can be an SMF entity in Figure 3, the control device 102 in Figure 1 can be an AS controller in Figure 3, the target user plane function entity in Figure 1 can be a UPF 1 entity in Figure 3, and the source user plane function entity in Figure 1 can be a UPF 2 entity in Figure 3. Furthermore, as shown in Figure 3, the network architecture can also include a terminal, an access device, an AMF entity, and a DN. An AS is deployed on the DN.To ensure the shortest possible path between the terminal and the AS, the UPF entity and the AS generally need to be deployed locally. However, for a service with a low end-to-end latency requirement, the UPF entity and the AS cannot be deployed locally. This is not specifically limited in this application modality.

[0074] The terminal communicates with the AMF entity using an N1 and communicates with UPF entities (including Petition 870240061722, dated 07 / 22 / 2024, p. 44 / 228 29 / 97 the UPF 1 entity to a UPF n entity) using the access device. The access device communicates with the AMF entity using an N2 and communicates with the UPF entities (including the UPF 1 entity to the UPF n entity) using an N3. The AMF entity communicates with the SMF entity using an N11. The SMF entity communicates with the UPF entities (including the UPF 1 entity to the UPF n entity) using an N4. The UPF entity (including the UPF 1 entity to the UPF n entity) communicates with DNs (including a DN 1 to a DN n) using an N6.

[0075] In this scenario, for a terminal using a URLLC service, during a terminal movement process, it may be necessary to perform a UPF entity transfer and an AS transfer. The AS controller maintains AS topology information and can perform AS selection or re-selection based on the location information of the local UPF entity and / or the terminal location information. Therefore, when a UPF entity transfer needs to be performed, the SMF entity needs to interact with the AS controller to implement AS re-selection in order to implement the shortest path between the terminal and the AS.

[0076] It should be noted that Figure 3 shows an example in which different UPF entities communicate with ASs on different DNs. Certainly, alternatively, different UPF entities can communicate with an AS on the same DN. In other words, after the UPF entity transfer, the AS transfer may not occur. This is not specifically limited in this mode. Petition 870240061722, dated 07 / 22 / 2024, p. 45 / 228 30 / 97 of this request.

[0077] It should be noted that the interface names between the network elements in Figure 2 and Figure 3 are merely examples, and the interfaces may have other names during the specific implementation. This is not specifically limited in this embodiment of this application.

[0078] It should be noted that the access device, AMF entity, SMF entity, UPF entity, AS, AS controller, and the like in Figure 2 and Figure 3 are merely names, and the names do not constitute a limitation on the devices. In the 5G network and other future networks, the access device, AMF entity, SMF entity, UPF entity, AS, and AS controller may have other names. This is not specifically limited in this embodiment of this application. For example, the UPF entity may alternatively be replaced by a UP, the AS may be replaced by an application management platform or a mobile edge computing (MEC) platform, and the AS controller may be replaced by a vehicle-to-everything (V2X) communication control function entity or the like. A general description is provided here, and the details are not described again below.

[0079] Optionally, the terminal in this embodiment of this application may include various portable devices, vehicle-mounted devices, wearable devices, and computing devices that have a wireless communication function or other processing devices connected to a wireless modem. The terminal may also include a subscriber unit, a Petition 870240061722, dated 07 / 22 / 2024, page 46 / 228 31 / 97 a cellular phone, a smartphone, a wireless data card, a personal digital assistant (PDA) computer, a tablet computer, a wireless modem, a handheld device, a laptop computer, a cordless phone or a wireless local loop (WLL) station, a machine-type communication (MTC) terminal, user equipment (UE), a mobile station (MS), a terminal device, and the like. For ease of description, the devices mentioned above are collectively referred to as a terminal in this application.

[0080] Optionally, the access device in this embodiment of this application is a device that accesses a core network. For example, the access device may be a base station, a broadband network gateway (BNG), an aggregation switch, or a non-3GPP access device. The base station may include a macro base station, a micro base station (also referred to as a small cell), a relay station, an access point, and the like in various ways.

[0081] Optionally, the AMF entity in this modality of this request is responsible for functions such as record management, mobility management and lawful interception.

[0082] Optionally, for functions of the SMF entity and the AS controller in this mode of this request, see the descriptions in Figure 1. Details are not Petition 870240061722, dated 07 / 22 / 2024, p. 47 / 228 32 / 97 described here again. Furthermore, the SMF entity is further configured to perform session management, including session establishment, modification, release, and other session-related control functions such as allocation and management of a terminal IP address, selection and control of the UPF entity, and lawful interception.

[0083] Optionally, the UPF entity in this embodiment of this application may be responsible for processing functions such as routing and collecting statistics from a terminal packet. For example, the UPF entity may perform user plane functions of a serving gateway (SGW) and a packet data network gateway (PGW). Alternatively, the UPF entity may be a software-defined network (SDN) switch. This is not specifically limited in this embodiment of this application.

[0084] Optionally, the session management function entity 101 and the control device 102 in Figure 1 may be implemented by a single physical device, or may be implemented jointly by a plurality of physical devices, or may be a logic function module on a single physical device. This is not specifically limited in this embodiment of this application.

[0085] For example, as shown in Figure 4, the session management function entity 101 and the control device 102 in Figure 1 can be implemented by a communications device in Figure 4.

[0086] Figure 4 is a schematic diagram of a Petition 870240061722, dated 07 / 22 / 2024, page 48 / 228 33 / 97 hardware structure of a communications device according to an embodiment of this application. The communications device 400 includes at least one processor 401, a communications bus 402, a memory 403 and at least one communications interface 404.

[0087] The 401 processor can be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to control the execution of a program in the solutions of this application.

[0088] The 402 communications bus may include a path used to transmit information between the preceding components.

[0089] A 404 communications interface is any device, such as a transceiver, that is configured to communicate with another device or communications network, such as Ethernet, a radio access network (RAN), or a wireless local area network (WLAN).

[0090] Memory 403 can be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, a random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or it can be an electrically erasable programmable read-only memory (EEPROM), a memory only Petition 870240061722, dated 07 / 22 / 2024, page 49 / 228 34 / 97 compact disc read-only memory (CD-ROM) or other compact disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray optical disc and the like), magnetic disc storage medium or other magnetic storage device, or any other medium capable of carrying or storing the expected program code in the form of instructions or data structures and capable of being accessed by a computer, but not limited to these. Memory may exist independently and is connected to the processor using the bus. Alternatively, memory may be integrated into the processor.

[0091] Memory 403 is configured to store the application program code for implementing the solutions in this application, and the application program code is executed under the control of processor 401. Processor 401 is configured to execute the application program code stored in memory 403, to implement a service continuity implementation method provided in the following embodiments of this application.

[0092] During a specific implementation, in one embodiment, the 401 processor may include one or more CPUs, for example, a CPU 0 and a CPU 1 in Figure 4.

[0093] During a specific implementation, in one embodiment, the communications device 400 may include a plurality of processors, for example, processor 401 and processor 408 in Figure 4. Each of these processors may be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). Petition 870240061722, dated 07 / 22 / 2024, page 50 / 228 35 / 97 (CPU). The processor referred to here may be one or more devices, circuits, and / or processing cores configured to process data (e.g., a computer program instruction).

[0094] During a specific implementation, in one embodiment, the communications device 400 may further include an output device 405 and an input device 406. The output device 405 communicates with the processor 401 and may display information in a plurality of ways. For example, the output device 405 may be a liquid crystal display (LCD), a light-emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector. The input device 406 communicates with the processor 401 and may receive user input in a plurality of ways. For example, the input device 406 may be a mouse, a keyboard, a touch-screen device, or a sensor device.

[0095] The communications device 400 can be a general-purpose communications device or a dedicated communications device. During specific implementation, the communications device 400 can be a desktop computer, a laptop computer, a network server, a palmtop computer (personal digital assistant, PDA), a mobile phone, a tablet computer, a wireless terminal device, an embedded device, or a device with a structure similar to that in Figure 4. One type of communications device 400 is not limited. Petition 870240061722, dated 07 / 22 / 2024, page 51 / 228 36 / 97 in this type of request.

[0096] The following describes in detail a method of implementing service continuity provided in the modalities of this application with reference to Figure 1 to Figure 4.

[0097] First, with reference to the service continuity implementation system 10 shown in Figure 1, Figure 5 is a schematic flowchart of a service continuity implementation method according to one embodiment of this application. Interactions between a session management function entity 101, a control device 102 and a target user plane function entity 103 are involved, and the following steps are included.

[0098] S501. The session management role entity selects the target user plane role entity to serve a terminal.

[0099] S502. The session management function entity sends a first message to the control device, so that the control device receives the first message from the session management function entity.

[00100] S503. The control device sends first AS indication information to the session management function entity, so that the session management function entity receives the first AS indication information from the control device.

[00101] Optionally, in this type of request, the information indicating the first AS may be location information of the first AS, identifier information Petition 870240061722, dated 07 / 22 / 2024, p. 52 / 228 37 / 97 of the first AS, information indicating that the AS does not change, or similar. This is not specifically limited to this modality of this request.

[00102] S504. The session management role entity sends a first routing rule to the target user plane role entity based on the first AS indication information, such that the target user plane role entity receives the first routing rule from the session management role entity, where the first routing rule includes data whose destination address is an address of the first AS is sent to the first AS.

[00103] For a related description of the routing rule, see the descriptions in the modalities section of the preface. The details are not described here again.

[00104] According to the service continuity implementation method provided in this embodiment of this application, in one aspect, after the session management role entity selects the target user plane role entity to serve the endpoint, the session management role entity can receive the first AS indication information and send the first routing rule to the target user plane role entity based on the first AS indication information, so that the target user plane role entity can transmit service data according to the first routing rule. Therefore, service continuity can be guaranteed in a user plane role entity transfer process. In another aspect, the first routing rule is that the data whose destination address Petition 870240061722, dated 07 / 22 / 2024, page 53 / 228 38 / 97 is the address of the first AS, and data is sent to the first AS. This prevents the target user plane role entity from routing data that should be sent to the first AS address first to a remote DN and then to the first AS. Therefore, a path from the endpoint to the first AS is shorter, and latency is controllable.

[00105] The actions of the session management function entity in steps S501, S502, and S504 can be performed by processor 401 on communications device 400 shown in Figure 4 by invoking the application program code stored in memory 403. This is not limited to this embodiment of this application.

[00106] The action of the control device in step 503 can be performed by processor 401 on communications device 400 shown in Figure 4 by invoking the application program code stored in memory 403. This is not limited to this embodiment of this application.

[00107] Then, the service continuity implementation method shown in Figure 5 is described in detail using an example where the service continuity implementation system 10 shown in Figure 1 is applied to scenario 1 shown in Figure 2.

[00108] It is assumed that in an initial state, a terminal communicates with an AS 1 using an access device (referred to as an originating base station here) and a local UPF entity 2 (referred to as an originating UPF entity here). Furthermore, the terminal communicates with a remote DN (referred to here as A-DN) using the originating UPF entity and a remote UPF entity (referred to here as an A-UPF entity). Figure 6A and Figure 6B are a flowchart. Petition 870240061722, dated 07 / 22 / 2024, p. 54 / 228 39 / 97 schematic of a service continuity implementation method according to one embodiment of this application. Interactions between the terminal, the originating base station, a target base station, the originating UPF entity, a local UPF entity 1 (referred to here as a target UPF entity), the A-UPF entity, an AMF entity, an SMF entity, an AS controller, AS 1 and AS 2 are involved, and the following steps are included.

[00109] S601. When the terminal moves, the originating base station initiates a radio transfer.

[00110] For a specific implementation of initiating an air interface transfer from the originating base station, please refer to an existing solution. Details are not described here.

[00111] S602. After completing the air interface transfer, the target base station sends a path switching request to the SMF entity, so that the SMF entity receives the path switching request from the target base station.

[00112] The path switching request includes N3 tunnel uplink information from the target base station, terminal location information, and the like. An N3 tunnel from the target base station is specifically a tunnel between the target base station and the target UPF entity. The N3 tunnel uplink information from the target base station may specifically include an endpoint address of the N3 tunnel from the target base station on the target base station side, an address of the target base station, and the like. This is not specifically limited in this embodiment of this request. Petition 870240061722, dated 07 / 22 / 2024, page 55 / 228 40 / 97

[00113] S603. The SMF entity selects, based on the terminal's location information, the target UPF entity to service the terminal.

[00114] Optionally, if a terminal location exceeds a service range of the originating UPF entity, the SMF entity may determine that local UPF entity re-selection needs to be performed.

[00115] Optionally, the SMF entity may select, based on at least one of the terminal location information, a service capacity of a local UPF entity managed by the SMF entity, or a loading status of the local UPF entity managed by the SMF entity, the target UPF entity to serve the terminal. This is not specifically limited in this modality of this request.

[00116] S604. The SMF entity sends an N4 1 session establishment request to the target UPF entity, such that the target UPF entity receives the N4 1 session establishment request from the SMF entity.

[00117] Optionally, the N4 1 session establishment request may include a second routing rule. The second routing rule includes data whose destination address is an AS 1 address is sent to the originating UPF entity.

[00118] Optionally, the N4 1 session establishment request may include initial path information. The initial path information is used to establish a routing path between the source UPF entity and the target UPF entity. Petition 870240061722, dated 07 / 22 / 2024, p. 56 / 228 41 / 97

[00119] The first path information in this embodiment of this request may include the first downlink information of an N9 tunnel from the source UPF entity. Optionally, the first path information in this embodiment of this request may also include the first uplink information of an N9 tunnel from the target UPF entity. A first N9 tunnel from the source UPF entity and a first N9 tunnel from the target UPF entity are specifically tunnels between the source UPF entity and the target UPF entity. The first downlink information of an N9 tunnel from the source UPF entity may specifically include an endpoint address of the first N9 tunnel from the source UPF entity on the source UPF entity side, an address of the source UPF entity, and the like. This is not specifically limited in this embodiment of this request.The first uplink information of the target UPF entity's N9 tunnel may specifically include an endpoint address of the first N9 tunnel of the target UPF entity on the target UPF entity side, an address of the target UPF entity, and the like. This is not specifically limited in this embodiment of this request. The first downlink information of the source UPF entity's N9 tunnel may be allocated by the SMF entity, or it may be allocated by the source UPF entity. This is not specifically limited in this embodiment of this request. The first uplink information of the target UPF entity's N9 tunnel may be allocated by the SMF entity, or it may be allocated by the target UPF entity. This is not specifically limited in this embodiment of this request. Petition 870240061722, dated 07 / 22 / 2024, p. 57 / 228 42 / 97

[00120] Optionally, the N4 1 session establishment request may include a third routing rule. The third routing rule includes whether data whose destination address is an A-DN address or data whose destination address is the default is sent to the A-UPF entity.

[00121] Optionally, the N4 1 session establishment request may include third path information. The third path information is used to establish a routing path between the target UPF entity and the A-UPF entity.

[00122] The third path information in this embodiment of this request may include second downlink information for the N9 tunnel of the A-UPF entity. Optionally, the third path information in this embodiment of this request may also include second uplink information for the N9 tunnel of the target UPF entity. A second N9 tunnel of the A-UPF entity and a second N9 tunnel of the target UPF entity are specifically tunnels between the A-UPF entity and the target UPF entity. The second downlink information for the N9 tunnel of the A-UPF entity may specifically include an endpoint address of the second N9 tunnel of the A-UPF entity on the A-UPF entity side, an address of the A-UPF entity, and the like. This is not specifically limited in this embodiment of this request.The second uplink information for the target UPF entity's N9 tunnel may specifically include an endpoint address for the second N9 tunnel from the target UPF entity on the target UPF entity side, the entity's address. Petition 870240061722, dated 07 / 22 / 2024, p. 58 / 228 43 / 97 of target UPF and similar. This is not specifically limited in this embodiment of this request. The second downlink information of the N9 tunnel of the A-UPF entity may be allocated by the SMF entity, or may be allocated by the A-UPF entity. This is not specifically limited in this embodiment of this request. The second uplink information of the N9 tunnel of the target UPF entity may be allocated by the SMF entity, or may be allocated by the target UPF entity. This is not specifically limited in this embodiment of this request.

[00123] Optionally, the N4 1 session establishment request may include seventh path information. The seventh path information is used to establish a forwarding path between the target UPF entity and the target base station.

[00124] The seventh route information in this embodiment of this request may include the N3 tunnel uplink information of the target base station in the route switching request. Optionally, if the N3 tunnel downlink information of the target UPF entity is allocated by the SMF entity, the seventh route information may further include the N3 tunnel downlink information of the target UPF entity. This is not specifically limited in this embodiment of this request. A target UPF entity N3 tunnel is specifically a tunnel between the target base station and the target UPF entity. The target UPF entity N3 tunnel downlink information may specifically include a target UPF entity N3 tunnel terminal address on the target UPF entity side, the target UPF entity address, and Petition 870240061722, dated 07 / 22 / 2024, p. 59 / 228 44 / 97 similar. This is not specifically limited in this modality of this request. Certainly, the downlink information of the N3 tunnel of the target UPF entity can alternatively be allocated by the target UPF entity. This is not specifically limited in this modality of this request.

[00125] In addition, the N4 1 session establishment request may also include other user plan information from an existing PDU session, for example, a data packet statistics collection and reporting rule and a quality of service (QoS) rule. This is not specifically limited in this modality of this request.

[00126] Optionally, the information included in the N4 1 session establishment request can be sent to the target UPF entity using different messages. This is not specifically limited in this modality of this request.

[00127] S605. The target UPF entity sends a Session Establishment Response 1 to the SMF entity, such that the SMF entity receives the Session Establishment Response 1 from the target UPF entity.

[00128] S606. The SMF entity sends an N4 2 session establishment request to the originating UPF entity, such that the originating UPF entity receives the N4 2 session establishment request from the SMF entity.

[00129] Optionally, the N4 2 session establishment request may include a fourth routing rule. The fourth routing rule includes data whose destination address is a terminal address. Petition 870240061722, dated 07 / 22 / 2024, p. 60 / 228 45 / 97 sent to the target UPF entity.

[00130] Optionally, the N4 2 session establishment request may include second path information. The second path information is used to establish the routing path between the source UPF entity and the target UPF entity.

[00131] The second route information in this modality of this request may include the first uplink information from the N9 tunnel of the target UPF entity. Optionally, the second route information in this modality of this request may also include the first downlink information from the N9 tunnel of the originating UPF entity.

[00132] Optionally, the N4 2 session establishment request may also include initial tunnel deletion indication information. The initial tunnel deletion indication information is used to instruct to delete an N3 tunnel from the originating UPF entity or to set the N3 tunnel of the originating UPF entity as invalid. The N3 tunnel of the originating UPF entity is specifically a tunnel between the originating UPF entity and the originating base station.

[00133] Optionally, the N4 2 session establishment request may also include second tunnel deletion indication information. The second tunnel deletion indication information is used to instruct to delete a second N9 tunnel from the source UPF entity or to set the second N9 tunnel from the source UPF entity as invalid. The second N9 tunnel from the source UPF entity is specifically a tunnel between Petition 870240061722, dated 07 / 22 / 2024, page 61 / 228 46 / 97 the originating UPF entity and the A-UPF entity.

[00134] In addition, the N4 2 session establishment request may also include other user plan information from the current PDU session, for example, the data packet statistics collection and reporting rule and the QoS rule. This is not specifically limited in this modality of this request.

[00135] Optionally, the information included in the N4 2 session establishment request can be sent to the originating UPF entity using different messages. This is not specifically limited in this modality of this request.

[00136] S607. The originating UPF entity sends a Session Establishment Response 2 to the SMF entity, such that the SMF entity receives the Session Establishment Response 2 from the originating UPF entity.

[00137] It should be noted that if the first path information in step S604 and the second path information in step S606 include the first downlink tunnel information from the source UPF entity and the first uplink tunnel information from the target UPF entity, the first path information may be the same as the second path information. Alternatively, the first path information in step S604 may be different from the second path information in step S606. For example, the first path information includes only the first downlink tunnel information from the source UPF entity, and the second path information includes only the first downlink tunnel information. Petition 870240061722, dated 07 / 22 / 2024, p. 62 / 228 47 / 97 N9 tunnel uplink from the target UPF entity. This is not specifically limited in this modality of this request.

[00138] S608. The SMF entity sends an N4 3 session establishment request to the A-UPF entity, such that the A-UPF entity receives the N4 3 session establishment request from the SMF entity.

[00139] Optionally, the N4 3 session establishment request may include the fourth routing rule. The fourth routing rule includes data whose destination address is the endpoint address is sent to the target UPF entity.

[00140] Optionally, the N4 3 session establishment request may include fourth path information. The fourth path information is used to establish the routing path between the A-UPF entity and the target UPF entity.

[00141] The fourth path information in this modality of this request may include the second N9 tunnel uplink information from the target UPF entity. Optionally, the fourth path information in this modality of this request may also include the second N9 tunnel downlink information from the A-UPF entity.

[00142] Optionally, the N4 3 session establishment request may also include a second tunnel deletion indication. The second tunnel deletion indication is used to instruct the deletion of a first N9 tunnel from entity A. Petition 870240061722, dated 07 / 22 / 2024, p. 63 / 228 48 / 97 UPF, or define the first N9 tunnel of the A-UPF entity as invalid. The first N9 tunnel of the A-UPF entity is specifically a tunnel between the source UPF entity and the A-UPF entity.

[00143] In addition, the N4 3 session establishment request may also include other user plan information from the current PDU session, for example, the data packet statistics collection and reporting rule and the QoS rule. This is not specifically limited in this type of request.

[00144] Optionally, the information included in the N4 3 session establishment request can be sent to the originating UPF entity using different messages. This is not specifically limited in this mode of this request.

[00145] S609. The A-UPF entity sends a Session Establishment Response 3 to the SMF entity, such that the SMF entity receives the Session Establishment Response 3 from the A-UPF entity.

[00146] It should be noted that if the third path information in step S604 and the fourth path information in step S608 include the second downlink tunnel information from N9 of the A-UPF entity and the second uplink tunnel information from N9 of the target UPF entity, the third path information may be the same as the fourth path information. Alternatively, the third path information in step S604 may be different from the fourth path information in step S608. For example, the third path information includes only the second downlink tunnel information from N9 of the Petition 870240061722, dated 07 / 22 / 2024, p. 64 / 228 49 / 97 A-UPF entity, and the fourth path information includes only the second N9 tunnel uplink information from the target UPF entity. This is not specifically limited in this modality of this request.

[00147] S610. The SMF entity sends a path switching response to the target base station, so that the target base station receives the path switching response from the SMF entity.

[00148] Optionally, the path switching response may include eighth path information. The eighth path information is used to establish the forwarding path between the target base station and the target UPF entity.

[00149] The eighth route information in this modality of this request may include the downlink information of the N3 tunnel of the target UPF entity. Optionally, the eighth route information in this modality of this request may also include the uplink information of the N3 tunnel of the target base station.

[00150] In addition, the path switching response may also include other user plan information from the current PDU session, for example, the data packet statistics collection and reporting rule and the QoS rule. This is not specifically limited in this modality of this request.

[00151] Optionally, the information included in the path switching response can be sent to the target base station using different messages. This is not specifically limited in this mode of this request.

[00152] It should be noted that, if the seventh piece of information Petition 870240061722, dated 07 / 22 / 2024, page 65 / 228 The 50 / 97 path information in step S604 and the eighth path information in step S610 include the N3 tunnel downlink information from the target UPF entity and the N3 tunnel uplink information from the target base station; the seventh path information can be the same as the eighth path information. Alternatively, the seventh path information in step S604 can be different from the eighth path information in step S610. For example, the seventh path information includes only the N3 tunnel uplink information from the target base station, and the second path information includes only the N3 tunnel downlink information from the target UPF entity. This is not specifically limited in this embodiment of this application.

[00153] S611. The target base station releases a resource from the source base station.

[00154] For a specific implementation of releasing the source base station resource by the target base station, please refer to an existing solution. Details are not described here.

[00155] In conclusion, steps S604 to S611 can be performed to delete: The tunnel between the originating UPF entity and the originating base station, and the tunnel between the originating UPF entity and the A-UPF entity.

[00156] Steps S604 through S611 can be performed to establish: The tunnel between the source UPF entity and the target UPF entity, and the tunnel between the target UPF entity and the A-UPF entity. Petition 870240061722, dated 07 / 22 / 2024, p. 66 / 228 51 / 97

[00157] In other words, the target UPF entity can be added to the current PDU session by performing step S604 to step S611. In this way, communication between the terminal and AS 1 can be maintained. In this case, the target UPF entity can be considered as a common hop of the UPF entity in a PDU session path. The corresponding service transmission paths are: the terminal <-> the target base station <-> the target UPF entity <-> the source UPF entity <-> AS 1; and the terminal <-> the target base station <-> the target UPF entity <-> the A-UPF entity <-> the A-DN.

[00158] It should be noted that there is no required sequence for performing steps S604 and S605, steps S606 and S607, and steps S608 and S609. Any group of steps in steps S604 and S605, steps S606 and S607, and steps S608 and S609 can be performed first, then any group of steps in the other two groups of steps can be performed, and finally, the last group of steps can be performed. For example, steps S604 and S605 can be performed first, then steps S606 and S607 can be performed, and finally, steps S608 and S609 can be performed. Certainly, alternatively, steps S604 and S605, steps S606 and S607, and steps S608 and S609 can be performed simultaneously. This is not specifically limited in this embodiment of this application.

[00159] It should be noted that steps S604 to S610 are described using an example in which an N9 tunnel (including the tunnel between the source UPF entity and the target UPF entity and the tunnel between the target UPF entity and the UPF entity) is an N9 tunnel at a granularity Petition 870240061722, dated 07 / 22 / 2024, p. 67 / 228 52 / 97 session. Certainly, alternatively, the N9 tunnel can be an N9 tunnel at a device granularity. This is not specifically limited in this embodiment of this application.

[00160] When the N9 tunnel is the N9 tunnel at a device granularity, if there is no N9 tunnel at a device granularity, the N9 tunnel at a device granularity is established in the previous way of establishing the N9 tunnel at a session granularity.

[00161] If the N9 tunnel at a device granularity exists, it may not be necessary to establish the N9 tunnel at a device granularity, and only one routing rule corresponding to the PDU session will be delivered. For example, the SMF entity sends the second routing rule to the target UPF entity, so that the target UPF entity can send the data whose destination address is the address of AS 1 to the source UPF entity through the tunnel between the source UPF entity and the target UPF entity. Alternatively, for example, the SMF entity sends the fourth routing rule to the source UPF entity, so that the source UPF entity can send the data whose destination address is the endpoint address to the target UPF entity through the tunnel between the source UPF entity and the target UPF entity.Alternatively, for example, the SMF entity sends the third routing rule to the target UPF entity, so that the target UPF entity can send the data whose destination address is the A-DN address to the A-UPF entity through the tunnel between the target UPF entity and the A-UPF entity. Petition 870240061722, dated 07 / 22 / 2024, p. 68 / 228 53 / 97 A-UPF entity. Alternatively, for example, the SMF entity sends the fourth routing rule to the A-UPF entity, so that the A-UPF entity can send the data whose destination address is the terminal address to the target UPF entity through the tunnel between the target UPF entity and the A-UPF entity.

[00162] When the N9 tunnel is the N9 tunnel at a device granularity, the N9 tunnel at a device granularity usually does not exist, and needs to be newly established in the following scenarios: 1. The source UPF entity or the target UPF entity is linked; 2. It is necessary to establish a routing rule corresponding to the N9 tunnel at the device granularity; and 3. Other cases.

[00163] S612. The SMF entity sends a first message to the AS controller, so that the AS controller receives the first message from the SMF entity.

[00164] Optionally, the first message in this mode of this request may be a PDU session change message.

[00165] Optionally, in this mode of this request, the first message may include at least one of the target UPF entity location information or terminal location information. At least one of the target UPF entity location information or terminal location information is used to determine that an AS to serve the terminal is AS 2.

[00166] Optionally, the SMF entity may Petition 870240061722, dated 07 / 22 / 2024, p. 69 / 228 54 / 97 determines, according to a local policy, that the first message must be sent to the AS controller. The local policy may include a service type or a 5G QoS identifier (5G QoS indicator, 5QI).

[00167] Alternatively, the SMF entity can sign this type of message. Furthermore, after the UPF entity is changed, the SMF entity is triggered to send the first message to the AS controller. This is not specifically limited in this mode of this request.

[00168] Optionally, in this embodiment of this application, the SMF entity may communicate directly with the AS controller, or it may communicate with the AS controller using a network exposure function (NEF) entity or a policy control function (PCF). A general description is provided here, and the details are not described again below.

[00169] It should be noted that there is no required sequence to perform steps S612 and steps S604 to S611. Step S612 can be performed before steps S604 to S611. Alternatively, steps S604 to S611 can be performed before step S612. Alternatively, steps S612 and steps S604 to S611 can be performed simultaneously. This is not specifically limited in this embodiment of this application.

[00170] S613. The AS controller determines, based on the first message, that the AS to service the terminal is AS 2.

[00171] Optionally, the AS controller may determine, based on at least one piece of information from Petition 870240061722, dated 07 / 22 / 2024, p. 70 / 228 55 / 97 location of the target UPF entity or the terminal location information included in the first message, indicating that the AS to service the terminal is AS 2.

[00172] S614. The AS controller sends an AS synchronization request to AS 1, so that AS 1 receives the AS synchronization request from the AS controller, where the AS synchronization request is used to request that AS 1 synchronize the terminal information in AS 2.

[00173] The information synchronized about the endpoint may include service authentication information, historical data, context, and the like. This is not specifically limited to this modality of this request.

[00174] It should be noted that the AS synchronization request in this mode of this request may also have another name, and the name does not constitute a limitation in the message. For example, the AS synchronization request may also be called an AS transfer request. A general description is provided here, and the details are not described again below.

[00175] S615. AS 1 synchronizes terminal information with AS 2.

[00176] S616. AS 1 sends an AS synchronization response to the AS controller, so that the AS controller receives the AS 1 synchronization response, where the synchronization response is used to indicate that synchronization between AS 1 and AS 2 has been completed.

[00177] Optionally, AS 2 can send an AS synchronization response to the AS controller, so that the AS controller receives the AS synchronization response. Petition 870240061722, dated 07 / 22 / 2024, page 71 / 228 56 / 97 2, where the AS synchronization response is used to indicate that synchronization between AS 1 and AS 2 has been completed. This is not specifically limited to this mode of this request.

[00178] It should be noted that the AS synchronization response in this mode of this request may also have another name, and the name does not constitute a limitation on the message. For example, the AS synchronization response may also be called the AS transfer response. A general description is provided here, and the details are not described again below.

[00179] S617. The AS controller sends AS 2 indication information to the SMF entity, so that the SMF entity receives the AS 2 indication information from the AS controller.

[00180] Optionally, the AS 2 indicator information can be AS 2 location information.

[00181] S618. The SMF entity sends an offload rule update request to the target UPF entity, such that the target UPF entity receives the offload rule update request from the SMF entity, where the offload rule update request includes a first routing rule, and the first routing rule includes such data whose destination address is an address of AS 2 is sent to AS 2.

[00182] In addition, after receiving the request to update the offload rule from the SMF entity, the target UPF entity can add the first routing rule to a local offload rule. This Petition 870240061722, dated 07 / 22 / 2024, p. 72 / 228 In the 57 / 97 manner, the target UPF entity can send data whose destination address is the address of AS 2 to AS 2. This prevents the target UPF entity from sending data that should be sent to the AS 2 address first to the A-UPF entity according to a standard ULCL rule and then to AS 2 using A-DN. Therefore, a path from the terminal to AS 2 is shorter, and the latency is manageable.

[00183] In addition, the target UPF entity's local offload rule also includes the second routing rule and the third routing rule. Therefore, the target UPF entity still transmits data according to the service transmission paths in step S610, i.e., it still sends the data whose destination address is AS 1 to the source UPF entity, and sends another data packet to the A-UPF entity according to a standard rule. This is not specifically limited in this modality of this request.

[00184] In this case, the corresponding service transmission paths are: the terminal <-> the target base station <-> the target UPF entity <-> AS 2; the terminal <-> the target base station <-> the target UPF entity <-> the source UPF entity <-> AS 1; and the terminal <-> the target base station <-> the target UPF entity <-> the A-UPF entity <-> the A-DN.

[00185] S619. The target UPF entity sends an offload rule update response to the SMF entity, such that the AS controller receives the offload rule update response from the SMF entity, where the offload rule update response of Petition 870240061722, dated 07 / 22 / 2024, p. 73 / 228 58 / 97 offload is used to indicate that the local offload rule has been established and that a network-side path is ready.

[00186] S620. The SMF entity sends a seventh message to the AS controller, so that the AS controller receives the seventh message from the SMF entity, where the seventh message is used to instruct the terminal to be switched from AS 1 to AS 2.

[00187] S621. The AS controller switches the terminal from AS 1 to AS 2 based on the seventh message.

[00188] S622. The AS controller sends an eighth message to the SMF entity, so that the SMF entity receives the eighth message from the AS controller, where the eighth message is used to indicate that the terminal has been switched from AS 1 to AS 2.

[00189] S623. The SMF entity sends an N4 session modification request to the target UPF entity, such that the target UPF entity receives the N4 session modification request from the SMF entity.

[00190] Optionally, when the N9 tunnel is the N9 tunnel at a session granularity, the N4 session modification request may include first indication information, where the first indication information is used to instruct to delete the second routing rule and the first path information, i.e., delete the tunnel between the source UPF entity and the target UPF entity.

[00191] Optionally, when the N9 tunnel is the N9 tunnel at a device granularity, there are the following two possible implementations:

[00192] Method 1: In the target UPF entity, in addition to Petition 870240061722, dated 07 / 22 / 2024, p. 74 / 228 59 / 97 second routing rule, if there is another routing rule corresponding to the tunnel between the source UPF entity and the target UPF entity, the N4 session modification request may include a second indication piece of information, where the second indication piece of information is used to instruct the deletion of the second routing rule.

[00193] Alternatively, in the target UPF entity, if there is no other routing rule corresponding to the tunnel between the source UPF entity and the target UPF entity except the second routing rule, the N4 session modification request may include first indication information, where the first indication information is used to instruct to delete the second routing rule and the first path information, i.e., delete the tunnel between the source UPF entity and the target UPF entity.

[00194] Method 2: On the target UPF entity, in addition to the second routing rule, regardless of whether there is another routing rule corresponding to the tunnel between the source UPF entity and the target UPF entity, the N4 session modification request includes only the second indication information, where the second indication information is used to instruct the deletion of the second routing rule. In other words, when the N9 tunnel is the tunnel at a device granularity, and a user plane resource is released, the tunnel at a device granularity is not released, and only the routing rule corresponding to the current PDU session is deleted.

[00195] For related descriptions of the second routing rule and the first path information, see Petition 870240061722, dated 07 / 22 / 2024, page 75 / 228 60 / 97 step S604. The details are not described here again.

[00196] Optionally, the information included in the N4 session modification request can be sent to the target UPF entity using different messages. This is not specifically limited in this mode of this request.

[00197] S624. The target UPF entity sends an N4 session modification response to the SMF entity, such that the SMF entity receives the N4 session modification response from the target UPF entity.

[00198] S625. The SMF entity sends an N4 session release request to the originating UPF entity, such that the originating UPF entity receives the N4 session release request from the SMF entity.

[00199] The N4 session release request is used to request the deletion of user plan information, corresponding to the terminal, in the originating UPF entity.

[00200] Optionally, when the N9 tunnel is the N9 tunnel at a session granularity, the N4 session release request may include third indication information, where the third indication information is used to instruct to delete the fourth routing rule and the second path information, i.e., delete the tunnel between the source UPF entity and the target UPF entity.

[00201] Optionally, when the N9 tunnel is the N9 tunnel at a device granularity, there are the following two possible implementations:

[00202] Method 1: In the originating UPF entity, in addition Petition 870240061722, dated 07 / 22 / 2024, p. 76 / 228 61 / 97 of the fourth routing rule, if there is another routing rule corresponding to the tunnel between the source UPF entity and the target UPF entity, the N4 session release request may include the fourth indication information, where the fourth indication information is used to instruct to delete the fourth routing rule.

[00203] Alternatively, in the source UPF entity, if there is no other routing rule corresponding to the tunnel between the source UPF entity and the target UPF entity except the fourth routing rule, the N4 session release request may include third indication information, where the third indication information is used to instruct to delete the fourth routing rule and the second path information, i.e., delete the tunnel between the source UPF entity and the target UPF entity.

[00204] Method 2: In the source UPF entity, in addition to the fourth routing rule, regardless of whether there is another routing rule corresponding to the tunnel between the source UPF entity and the target UPF entity, the N4 session release request includes only the fourth indication information, where the fourth indication information is used to instruct to delete the fourth routing rule. In other words, when the N9 tunnel is the tunnel at a device granularity, and a user plane resource is released, the tunnel at a device granularity is not released, and only the routing rule corresponding to the current PDU session is deleted.

[00205] For related descriptions of the fourth routing rule and the second route information, see Petition 870240061722, dated 07 / 22 / 2024, page 77 / 228 62 / 97 step S606. The details are not described here again.

[00206] Optionally, in addition to the fourth routing rule and the second path information, the user plan information corresponding to the terminal may also include a packet detection rule, a QoS rule, and the like. This is not specifically limited in this modality of this request.

[00207] Optionally, the information included in the N4 session release request can be sent to the originating UPF entity using different messages. This is not specifically limited in this modality of this request.

[00208] S626. The originating UPF entity sends an N4 session release response to the SMF entity, such that the SMF entity receives the N4 session release response from the originating UPF entity.

[00209] In conclusion, steps S623 to S626 can be performed to delete the tunnel between the source UPF entity and the target UPF entity. In this case, communication between the terminal and AS 1 terminates. The corresponding service transmission paths are: the terminal <-> the target base station <-> the target UPF entity <-> AS 2; and the terminal <-> the target base station <-> the target UPF entity <-> the A-UPF entity <-> the A-DN.

[00210] It should be noted that there is no required sequence to perform steps S623 and S624 and steps S625 and S626. Steps S623 and S624 can be performed before steps S625 and S626. Alternatively, steps S625 and S626 can be performed before steps S623 and S624. Petition 870240061722, dated 07 / 22 / 2024, p. 78 / 228 63 / 97 Alternatively, steps S623 and S624 and steps S625 and S626 can be performed simultaneously. This is not specifically limited in this embodiment of this application.

[00211] According to the service continuity implementation method provided in this embodiment of this application, in one aspect, after the SMF entity selects the target UPF entity to serve the terminal, the SMF entity can receive the AS 2 indication information and sends the first routing rule to the target UPF entity based on the AS 2 indication information, so that the target UPF entity can transmit service data according to the first routing rule after the terminal is switched from AS 1 to AS 2. Furthermore, before the terminal is switched from AS 1 to AS 2, the SMF entity can continue to maintain a service connection between the terminal and AS 1. Therefore, uninterrupted service data transfer can be implemented in a scenario where both a UPF entity transfer and an AS entity transfer occur, to ensure service continuity in a transfer process.In another aspect, the first routing rule is that data whose destination address is AS 2 is sent to AS 2. This can prevent the target UPF entity from routing data that should be sent to the AS 2 address first to the A-DN and then to AS 2. Therefore, the path from the terminal to AS 2 is shorter, and the latency is controllable.

[00212] The actions of the SMF entity in steps S603, S604, S606, S608, S610, S612, S618, S620, S621, S623 and S625 can be performed by processor 401 on communications device 400 shown in Figure 4 by invoking the code of Petition 870240061722, dated 07 / 22 / 2024, p. 79 / 228 64 / 97 application program stored in memory 403. This is not limited in this mode of this request.

[00213] The actions of the AS controller in steps S613, S614, S617, S621 and S622 can be performed by processor 401 on communications device 400 shown in Figure 4 by invoking the application program code stored in memory 403. This is not limited in this embodiment of this application.

[00214] Optionally, it is assumed that, in an initial state, a terminal communicates with an AS 1 using an access device (referred to here as a source base station) and a local UPF entity 2 (referred to here as a source UPF entity). Furthermore, the terminal communicates with a remote DN (referred to here as A-DN) using the source UPF entity and a remote UPF entity (referred to here as an A-UPF entity). Figure 7A and Figure 7B are a schematic flowchart of another method of implementing continuity of service according to one embodiment of this request. Interactions between the terminal, the source base station, a target base station, the source UPF entity, a local UPF entity 1 (referred to here as a target UPF entity), the A-UPF entity, an AMF entity, an SMF entity, an AS controller, and AS 1 are involved, and the following steps are included.

[00215] Steps S701 to S712 are the same as steps S601 to S612. For details, see the embodiment shown in Figure 6A and Figure 6B. The details are not described here again.

[00216] S713. The AS controller determines, based Petition 870240061722, dated 07 / 22 / 2024, pp. 80 / 228 65 / 97 in the first message, which indicates that the AS to serve the terminal is AS 1.

[00217] Optionally, the AS controller can determine, based on at least one of the target UPF entity location information or the terminal location information included in the first message, that the AS serving the terminal is AS 1.

[00218] S714. The AS controller sends AS 1 indication information to the SMF entity, so that the SMF entity receives the AS 1 indication information from the AS controller.

[00219] Optionally, the AS 1 identifier information may be AS 1 location information, AS 1 identifier information, information indicating that AS 1 does not change, or similar. This is not specifically limited in this embodiment of this application.

[00220] After receiving the AS 1 indication information from the AS controller, the SMF entity can determine, based on the AS 1 indication information, that an AS transfer will not occur. For example, if the AS 1 indication information is the AS 1 location information, the AS 1 location information can be compared with the location information of an existing AS; and if the AS 1 location information is the same as the current AS location information, it is determined that the AS transfer will not occur.

[00221] S715. The SMF entity sends an N4 session modification request to the target UPF entity, such that the target UPF entity receives the N4 session modification request from the SMF entity. Petition 870240061722, dated 07 / 22 / 2024, p. 81 / 228 66 / 97

[00222] The N4 session modification request includes a first routing rule. The first routing rule includes data whose destination address is an AS 1 address being sent to AS 1. Additionally, after receiving the first routing rule from the SMF entity, the target UPF entity can add the first routing rule to a local offload rule.

[00223] Optionally, when the N9 tunnel is the N9 tunnel at a session granularity, the N4 session modification request may include first indication information, where the first indication information is used to instruct to delete the second routing rule and the first path information, i.e., delete the tunnel between the source UPF entity and the target UPF entity.

[00224] Optionally, when the N9 tunnel is the N9 tunnel at a device granularity, there are the following two possible implementations:

[00225] Method 1: On the target UPF entity, in addition to the second routing rule, if there is another routing rule corresponding to the tunnel between the source UPF entity and the target UPF entity, the N4 session modification request may include a second indication piece of information, where the second indication piece of information is used to instruct the deletion of the second routing rule.

[00226] Alternatively, in the target UPF entity, if there is no other routing rule corresponding to the tunnel between the source UPF entity and the target UPF entity, except for the second routing rule, the N4 session modification request may include first information. Petition 870240061722, dated 07 / 22 / 2024, p. 82 / 228 67 / 97 indication, where the first indication information is used to instruct the deletion of the second routing rule and the first path information, that is, to delete the tunnel between the source UPF entity and the target UPF entity.

[00227] Method 2: On the target UPF entity, in addition to the second routing rule, regardless of whether there is another routing rule corresponding to the tunnel between the source UPF entity and the target UPF entity, the N4 session modification request includes only the second indication information, where the second indication information is used to instruct to delete the second routing rule. In other words, when the N9 tunnel is the tunnel at a device granularity, and a user plane resource is released, the tunnel at a device granularity is not released, and only the routing rule corresponding to the current PDU session is deleted.

[00228] For related descriptions of the second routing rule and the first path information, see step S704. The details are not described here again.

[00229] Optionally, the information included in the N4 session modification request can be sent to the target UPF entity using different messages. This is not specifically limited in this mode of this request.

[00230] S716. The target UPF entity sends an N4 session modification response to the SMF entity, such that the SMF entity receives the N4 session modification response from the target UPF entity.

[00231] The first indication information or the second indication information in step S715 is used for Petition 870240061722, dated 07 / 22 / 2024, p. 83 / 228 Rule 68 / 97 instructs to delete the second routing rule. Therefore, the target UPF entity can directly send data whose destination address is the address of AS 1 to AS 1, without forwarding through the originating UPF entity. In this way, a path from the terminal to AS 1 is shorter, and the latency is controllable.

[00232] In addition, the target UPF entity's local offload rule also includes the third routing rule. Therefore, the target UPF entity still sends another data packet to the A-UPF entity according to a standard rule. This is not specifically limited in this mode of this request.

[00233] In this case, the corresponding service transmission paths are: the terminal <-> the target base station <-> the target UPF entity <-> AS 1; and the terminal <-> the target base station <-> the target UPF entity <-> the A-UPF entity <-> the A-DN.

[00234] S717. The SMF entity sends an N4 session release request to the originating UPF entity, such that the originating UPF entity receives the N4 session release request from the SMF entity.

[00235] The N4 session release request is used to request the deletion of user plan information, corresponding to the terminal, in the originating UPF entity.

[00236] Optionally, when the N9 tunnel is the N9 tunnel at a session granularity, the N4 session modification request may include third indication information, where third indication information is used Petition 870240061722, dated 07 / 22 / 2024, page 84 / 228 69 / 97 to instruct to delete the fourth routing rule and the second path information, that is, to delete the tunnel between the source UPF entity and the target UPF entity.

[00237] Optionally, when the N9 tunnel is the N9 tunnel at a device granularity, there are the following two possible implementations:

[00238] Method 1: In the source UPF entity, in addition to the fourth routing rule, if there is another routing rule corresponding to the tunnel between the source UPF entity and the target UPF entity, the N4 session release request may include the fourth indication information, where the fourth indication information is used to instruct to delete the fourth routing rule.

[00239] Alternatively, in the source UPF entity, if there is no other routing rule corresponding to the tunnel between the source UPF entity and the target UPF entity except the fourth routing rule, the N4 session release request may include third indication information, where the third indication information is used to instruct to delete the fourth routing rule and the second path information, i.e., delete the tunnel between the source UPF entity and the target UPF entity.

[00240] Method 2: In the source UPF entity, in addition to the fourth routing rule, regardless of whether there is another routing rule corresponding to the tunnel between the source UPF entity and the target UPF entity, the N4 session release request includes only the fourth indication information, where the fourth indication information is used to instruct to delete the fourth rule. Petition 870240061722, dated 07 / 22 / 2024, page 85 / 228 70 / 97 routing. In other words, when the N9 tunnel is the tunnel at a device granularity, and a user plane resource is released, the tunnel at a device granularity is not released, and only the routing rule corresponding to the current PDU session is deleted.

[00241] For related descriptions of the fourth routing rule and the second path information, see step S706. The details are not described here again.

[00242] Optionally, in addition to the fourth routing rule and the second path information, the user plan information corresponding to the terminal may also include a packet detection rule, a QoS rule, and the like. This is not specifically limited in this modality of this request.

[00243] Optionally, the information included in the N4 session release request can be sent to the originating UPF entity using different messages. This is not specifically limited in this modality of this request.

[00244] S718. The originating UPF entity sends an N4 session release response to the SMF entity, such that the SMF entity receives the N4 session release response from the originating UPF entity.

[00245] Steps S715 to S718 can be performed to delete the tunnel between the source UPF entity and the target UPF entity.

[00246] It should be noted that there is no required sequence to perform steps S715 and S716 and steps S717 and S718. Steps S717 and S718 can be performed before steps S715 and S716. Alternatively, steps S715 and Petition 870240061722, dated 07 / 22 / 2024, p. 86 / 228 71 / 97 Steps S716 can be performed before steps S717 and S718. Alternatively, steps S715 and S716, and steps S717 and S718 can be performed simultaneously. This is not specifically limited in this embodiment of this application.

[00247] According to the service continuity implementation method provided in this embodiment of this application, in one aspect, after the SMF entity selects the target UPF entity to serve the terminal, the SMF entity can receive the AS 1 indication information and send the first routing rule to the target UPF entity based on the AS 1 indication information, so that the target UPF entity can transmit service data according to the first routing rule. Furthermore, before the AS controller determines whether the AS transfer occurs, the SMF entity can continue to maintain a service connection between the terminal and AS 1. Therefore, uninterrupted service data transfer can be implemented in a scenario where a UPF entity transfer occurs, to ensure service continuity in a transfer process.In another aspect, the first routing rule is that data whose destination address is AS 1 is sent to AS 1. This can prevent the target UPF entity from routing data that should be sent to the AS 1 address first to the A-DN and then to AS 1. Therefore, the path from the terminal to AS 1 is shorter, and the latency is controllable.

[00248] The actions of the SMF entity in steps S703, S704, S706, S708, S710, S712, S715 and S717 can be performed by processor 401 on communications device 400 shown in Figure 4 by invoking the code of Petition 870240061722, dated 07 / 22 / 2024, p. 87 / 228 72 / 97 application program stored in memory 403. This is not limited to this mode of this request.

[00249] The actions of the AS controller in steps S713 and S714 can be performed by processor 401 on communications device 400 shown in Figure 4 by invoking the application program code stored in memory 403. This is not limited in this embodiment of this application.

[00250] The following describes in detail the service continuity implementation method shown in Figure 5, using an example in which the service continuity implementation system 10 shown in Figure 1 is applied to scenario 2 shown in Figure 3.

[00251] It is assumed that, in an initial state, a terminal communicates with an AS 1 using an access device (referred to here as a source base station) and a UPF 2 entity (referred to here as the source UPF entity). Figure 8A and Figure 8B are a schematic flowchart of a service continuity implementation method according to one embodiment of this request. Interactions between the terminal, the source base station, a target base station, the source UPF entity, a UPF 1 entity (referred to here as the target UPF entity), an AMF entity, an SMF entity, an AS controller, AS 1, and an AS 2 are involved, and the following steps are included.

[00252] Steps S801 and S802 are the same as steps S601 and S602. For details, see the embodiment shown in Figure 6A and Figure 6B. The details are not described here again.

[00253] S803. The SMF entity determines that the Petition 870240061722, dated 07 / 22 / 2024, pp. 88 / 228 73 / 97 re-selection of UPF entity needs to be carried out.

[00254] Optionally, if a terminal location exceeds a service range of the originating UPF entity, the SMF entity may determine that local UPF entity re-selection needs to be performed.

[00255] S804. The SMF entity sends an N4 session establishment request to the originating UPF entity, such that the originating UPF entity receives the N4 session establishment request from the SMF entity.

[00256] Optionally, the N4 session establishment request may include a fifth routing rule. The fifth routing rule includes data whose destination address is a terminal address is sent to the target base station.

[00257] Optionally, the N4 session establishment request may include ninth path information. The ninth path information is used to establish a routing path between the originating UPF entity and the base station.

[00258] The ninth path information in this mode of this request may include N3 tunnel uplink information from the target base station in the path switching request in step S802. Optionally, the ninth path information in this mode of this request may also include N3 tunnel downlink information from the originating UPF entity. An N3 tunnel from the originating UPF entity and an N3 tunnel from the target base station are specifically tunnels between the originating UPF entity and the target base station. The N3 tunnel uplink information from Petition 870240061722, dated 07 / 22 / 2024, page 89 / 228 74 / 97 target base station may specifically include an N3 tunnel endpoint address of the target base station on the target base station side, an address of the target base station, and the like. This is not specifically limited in this embodiment of this request. The N3 tunnel downlink information of the source UPF entity may specifically include an N3 tunnel endpoint address of the source UPF entity on the source UPF entity side, an address of the source UPF entity, and the like. This is not specifically limited in this embodiment of this request. The N3 tunnel downlink information of the source UPF entity may be allocated by the SMF entity or may be allocated by the source UPF entity. This is not specifically limited in this embodiment of this request.

[00259] Optionally, the N4 session establishment request may also include the first tunnel exclusion indication information. The first tunnel exclusion indication information is used to instruct to exclude the N3 tunnel from the originating UPF entity or to set the N3 tunnel of the originating UPF entity as invalid. The N3 tunnel of the originating UPF entity is specifically a tunnel between the originating UPF entity and the originating base station.

[00260] In addition, the N4 session establishment request may also include other user plan information from an existing PDU session, for example, a data packet statistics collection and reporting rule and a QoS rule. This is not specifically limited in this modality of this request. Petition 870240061722, dated 07 / 22 / 2024, pp. 90 / 228 75 / 97

[00261] Optionally, the information included in the N4 session establishment request can be sent to the originating UPF entity using different messages. This is not specifically limited in this mode of this request.

[00262] S805. The originating UPF entity sends a session establishment response to the SMF entity, so that the SMF entity receives the session establishment response from the originating UPF entity.

[00263] S806. The SMF entity sends a path switching response to the target base station, so that the target base station receives the path switching response from the SMF entity.

[00264] Optionally, the path switching response may include tenth path information. The tenth path information is used to establish the forwarding path between the target base station and the originating UPF entity.

[00265] The tenth route information in this mode of this request may include the downlink information of the N3 tunnel from the originating UPF entity. Optionally, the tenth route information in this mode of this request may also include the uplink information of the N3 tunnel from the target base station.

[00266] In addition, the path switching response may include other user plan information from the current PDU session, for example, the data packet statistics collection and reporting rule and the QoS rule. This is not specifically limited in this mode of this request. Petition 870240061722, dated 07 / 22 / 2024, pp. 91 / 228 76 / 97

[00267] Optionally, the information included in the path switching response can be sent to the target base station using different messages. This is not specifically limited in this mode of this request.

[00268] It should be noted that if the ninth path information in step S804 and the tenth path information in step S806 include the N3 tunnel downlink information from the originating UPF entity and the N3 tunnel uplink information from the target base station, the ninth path information may be the same as the tenth path information. Alternatively, the ninth route information in step S804 may be different from the tenth route information in step S806. For example, the ninth path information includes only the N3 tunnel uplink information from the target base station, and the tenth path information includes only the N3 tunnel downlink information from the originating UPF entity. This is not specifically limited in this embodiment of this application.

[00269] S807. The target base station releases a resource from the source base station.

[00270] For a specific implementation of releasing the source base station resource by the target base station, please refer to an existing solution. Details are not described here.

[00271] In conclusion, steps S804 to S807 can be performed to delete the tunnel between the originating UPF entity and the originating base station.

[00272] Steps S804 to S806 can be performed to establish the tunnel between the source UPF entity. Petition 870240061722, dated 07 / 22 / 2024, p. 92 / 228 77 / 97 and the target base station.

[00273] In other words, communication between the terminal and AS 1 can be maintained by performing steps S804 to S807. In this case, a corresponding service transmission path is: the terminal <-> the target base station <-> the source UPF entity <-> AS 1.

[00274] S808. The SMF entity sends a PDU session restoration notification to the endpoint, such that the endpoint receives the PDU session restoration notification from the SMF entity, where the PDU session restoration notification includes an identifier of a PDU session to be restored (PDU session ID).

[00275] It should be noted that there is no required sequence to perform steps S804 to S807 and step S808. Steps S804 to S807 can be performed before step S808. Alternatively, step S808 can be performed before steps S804 to S807. Alternatively, steps S804 to S807 and step S808 can be performed simultaneously. This is not specifically limited in this embodiment of this application.

[00276] S809. The terminal initiates a procedure to establish a new PDU session (referred to here as a second PDU session), where the SMF entity selects, in a process to establish the second PDU session, the target UPF entity to serve the terminal.

[00277] Optionally, in the process of establishing the second PDU session, the terminal may send an identifier for the second PDU session and an identifier for an older PDU session (referred to here as the first session). Petition 870240061722, dated 07 / 22 / 2024, page 93 / 228 78 / 97 of PDU) to the SMF entity, such that the SMF entity receives the identifier of the first PDU session and the identifier of the second PDU session from the terminal, and maintains a mapping relationship between the first PDU session and the second PDU session based on the identifier of the first PDU session and the identifier of the second PDU session. This is not specifically limited in this embodiment of this application.

[00278] Steps S810 to S815 are the same as steps S612 to S617. For details, see the embodiment shown in Figure 6A and Figure 6B. The details are not described here again.

[00279] S816. The SMF entity sends an N4 session modification request to the target UPF entity, such that the target UPF entity receives the N4 session modification request from the SMF entity.

[00280] The N4 session modification request includes a first routing rule. The first routing rule includes data whose destination address is an AS 2 address is sent to AS 2.

[00281] S817. The target UPF entity sends an N4 session modification response to the SMF entity, such that the SMF entity receives the N4 session modification response from the target UPF entity, where the N4 session modification response is used to indicate that the establishment of a lower-layer network instruction segmentation between the terminal and AS 2 is complete.

[00282] Currently, there are two sessions: the first PDU session and the second PDU session. Therefore, Petition 870240061722, dated 07 / 22 / 2024, pp. 94 / 228 Currently, under 79 / 97, the corresponding service transmission paths are: the terminal <-> the target base station <-> the originating UPF entity <-> AS 1 and the terminal <-> the target base station <-> the target UPF entity <-> AS 2.

[00283] Steps S818 to S820 are the same as steps S620 to S622. For details, see the embodiment shown in Figure 6A and Figure 6B. The details are not described here again.

[00284] S821. The SMF entity sends a sixth message to the terminal, so that the terminal receives the sixth message from the SMF entity, where the sixth message is used to instruct the terminal to release the first PDU session.

[00285] S822. The terminal releases the first PDU session based on the sixth message.

[00286] For a procedure to release the first PDU session from the terminal, see the previous technique. Details are not described here.

[00287] According to the service continuity implementation method provided in this embodiment of this application, in one aspect, after the SMF entity selects the target UPF entity to serve the terminal, the SMF entity can receive the AS 2 indication information and sends the first routing rule to the target UPF entity based on the AS 2 indication information, so that the target UPF entity can transmit service data according to the first routing rule after the terminal is switched from AS 1 to AS 2. Furthermore, before the terminal is switched from AS 1 to AS 2, the entity Petition 870240061722, dated 07 / 22 / 2024, pp. 95 / 228 SMF 80 / 97 can continue to maintain a service connection between the endpoint and AS 1. Therefore, uninterrupted service data transfer can be implemented in a scenario where both a UPF entity transfer and an AS entity transfer occur, to ensure continuity of service in a transfer process. On another aspect, the first routing rule is that data whose destination address is AS 2 is sent to AS 2. This can prevent the target UPF entity from routing data that should be sent to the AS 2 address first to a remote DN and then to AS 2. Therefore, a path from the endpoint to AS 2 is shorter, and latency is controllable.

[00288] The actions of the SMF entity in steps S803, S804, S806, S808, S809, S810, S816, S818, S819, S821 and S822 can be performed by processor 401 in communications device 400 shown in Figure 4 by invoking the application program code stored in memory 403. This is not limited in this embodiment of this application.

[00289] The actions of the AS controller in steps S811, S812, S815, S819 and S820 can be performed by processor 401 on communications device 400 shown in Figure 4 by invoking the application program code stored in memory 403. This is not limited in this embodiment of this application.

[00290] Optionally, it is assumed that, in an initial state, a terminal communicates with an AS 1 using an access device (referred to here as a source base station) and a UPF 2 entity (referred to here as a source UPF entity). Figure 9A and Figure 9B are a Petition 870240061722, dated 07 / 22 / 2024, pp. 96 / 228 81 / 97 Schematic flowchart of a service continuity implementation method according to one modality of this request. Interactions between the terminal, the originating base station, a target base station, the originating UPF entity, a UPF 1 entity (referred to here as the target UPF entity), an AMF entity, an SMF entity, an AS controller, and AS 1 are involved, and the following steps are included.

[00291] Steps S901 to S910 are the same as steps S801 to S810. For details, see the embodiment shown in Figure 8A and Figure 8B. The details are not described here again.

[00292] S911. The AS controller determines, based on the first message, that the AS serving the terminal is AS 1.

[00293] Optionally, the AS controller can determine, based on at least one of the target UPF entity location information or the terminal location information included in the first message, that the AS serving the terminal is AS 1.

[00294] S912. The AS controller sends AS 1 indication information to the SMF entity, so that the SMF entity receives the AS 1 indication information from the AS controller.

[00295] Optionally, the AS 1 identifier information may be AS 1 location information, AS 1 identifier information, information indicating that AS 1 does not change, or similar. This is not specifically limited in this embodiment of this application.

[00296] After receiving the AS 1 referral information from the AS controller, the SMF entity can Petition 870240061722, dated 07 / 22 / 2024, pp. 97 / 228 82 / 97 determine, based on the AS 1 indication information, that an AS transfer does not occur. For example, if the AS 1 indication information is the AS 1 location information, the AS 1 location information can be compared with the location information of a current AS; and if the AS 1 location information is the same as the current AS location information, it is determined that the AS transfer does not occur.

[00297] S913. The SMF entity sends an N4 session modification request to the target UPF entity, such that the target UPF entity receives the N4 session modification request from the SMF entity.

[00298] The N4 session modification request includes a first routing rule. The first routing rule includes data whose destination address is an AS 1 address is sent to AS 1.

[00299] S914. The target UPF entity sends an N4 session modification response to the SMF entity, such that the SMF entity receives the N4 session modification response from the target UPF entity, where the N4 session modification response is used to indicate that the establishment of a lower-layer network instruction segmentation between the terminal and AS 2 is complete.

[00300] Currently, there are two sessions: the first PDU session and the second PDU session. Therefore, currently, the corresponding service transmission paths are: the terminal <-> the target base station <-> the originating UPF entity <-> AS 1 and the terminal <-> the target base station <-> the UPF entity Petition 870240061722, dated 07 / 22 / 2024, pp. 98 / 228 83 / 97 target <-> AS 2.

[00301] S915. The SMF entity sends a sixth message to the terminal, so that the terminal receives the sixth message from the SMF entity, where the sixth message is used to instruct the terminal to release the first PDU session.

[00302] S916. The terminal releases the first PDU session based on the sixth message.

[00303] For a procedure to release the first PDU session from the terminal, see the previous technique. Details are not described here.

[00304] According to the service continuity implementation method provided in this embodiment of this application, in one aspect, after the SMF entity selects the target UPF entity to serve the terminal, the SMF entity can receive the AS 1 indication information and send the first routing rule to the target UPF entity based on the AS 1 indication information, so that the target UPF entity can transmit service data according to the first routing rule. Furthermore, before the AS controller determines whether the AS transfer occurs, the SMF entity can continue to maintain a service connection between the terminal and AS 1. Therefore, uninterrupted service data transfer can be implemented in a scenario where a UPF entity transfer occurs, to ensure service continuity in a transfer process.In another aspect, the first routing rule is that data whose destination address is AS 1 is sent to AS 1. This may prevent the target UPF entity from routing the data that should be sent. Petition 870240061722, dated 07 / 22 / 2024, pp. 99 / 228 84 / 97 to the AS 1 address first to a remote DN and then to AS 1. Therefore, a path from the terminal to AS 1 is shorter, and the latency is controllable.

[00305] The actions of the SMF entity in steps S903, S904, S906, S908, S909, S910, S913, S915 and S916 can be performed by processor 401 on communications device 400 shown in Figure 4 by invoking the application program code stored in memory 403. This is not limited in this embodiment of this application.

[00306] The actions of the AS controller in steps S911 and S912 can be performed by processor 401 on communications device 400 shown in Figure 4 by invoking the application program code stored in memory 403. This is not limited to this embodiment of this application.

[00307] The foregoing mainly describes, from a network element interaction perspective, the solutions provided in the embodiments of this application. It may be understood that, to implement the foregoing functions, the session management function entity and the control device include corresponding hardware structures and / or software modules to perform the functions. A person skilled in the art should be aware that, in combination with the examples described in the embodiments disclosed in this specification, the units and steps of the algorithm may be implemented using hardware or a combination of computer hardware and software. The execution of a function using hardware or software-driven hardware depends on specific applications and design constraints of the technical solutions. A person skilled in the art should be aware that, in combination with the examples described in the embodiments disclosed in this specification, the units and steps of the algorithm may be implemented using hardware or a combination of computer hardware and software. Petition 870240061722, dated 07 / 22 / 2024, pp. 100 / 228 The 85 / 97 technique may use different methods to implement the functions for each particular application, but it should not be implied that the implementation goes beyond the scope of that application.

[00308] In the embodiments of this application, the session management function entity and the control device can be divided into function modules based on the examples of previous methods. For example, each function module can be obtained by dividing based on each corresponding function, or two or more functions can be integrated into a processing module. The integrated module can be implemented in a hardware form or it can be implemented in the form of a software function module. It should be noted that, in the embodiments of this application, the module division is an example and is only a division of logical functions. During the actual implementation, another method of division may be used.

[00309] For example, when each function module is obtained by splitting based on each corresponding function, Figure 10 is a possible schematic structural diagram of the session management function entity 100 in the previous embodiments. The session management function entity 100 includes a selection module 1001, a sending module 1002, and a receiving module 1003. The selection module 1001 is configured to select a target user plane function entity to serve a terminal. The sending module 1002 is configured to send a first message to a control device. The receiving module 1003 is configured to receive indication information from a first AS from the control device. Petition 870240061722, dated 07 / 22 / 2024, pp. 101 / 228 86 / 97 The 1002 dispatch module is further configured to send a first routing rule to the target user plane role entity based on the first AS's indication information. The first routing rule includes data whose destination address is an address of the first AS that is sent to the first AS.

[00310] Optionally, the 1002 sending module is further configured to send a second routing rule to the target user plane function entity after the 1001 selection module selects the target user plane function entity to serve the endpoint, and before the first routing rule is sent to the target user plane function entity. The second routing rule includes data whose destination address is the address of a second AS being sent to a source user plane function entity, the second AS being an AS currently serving the endpoint, and the source user plane function entity being a user plane function entity communicatively connected to the second AS.

[00311] Optionally, the sending module 1002 is further configured to send the first path information to the target user plane function entity after the selection module 1001 selects the target user plane function entity to serve the terminal; and the sending module 1002 is further configured to send the second path information to the source user plane function entity after the selection module 1001 selects the target user plane function entity to serve the terminal. The first path information and the second path information are used to establish a Petition 870240061722, dated 07 / 22 / 2024, pp. 102 / 228 87 / 97 routing path between the target user plan function entity and the source user plan function entity.

[00312] Optionally, the 1002 sending module is further configured to send a third routing rule to the target user plane function entity after the 1001 selection module selects the target user plane function entity to serve the endpoint. The third routing rule includes data whose destination address is an address of a first data network being sent to a remote user plane function entity, and the remote user plane function entity is a user plane function entity communicatively connected to the first data network.

[00313] Optionally, the 1002 sending module is further configured to send third path information to the target user plane function entity after the 1001 selection module selects the target user plane function entity to serve the endpoint; and the 1002 sending module is further configured to send fourth path information to the remote user plane function entity after the 1001 selection module selects the target user plane function entity to serve the endpoint. The third path information and the fourth path information are used to establish a forwarding path between the target user plane function entity and the remote user plane function entity.

[00314] Optionally, the 1002 sending module is also configured to send a second message to the entity. Petition 870240061722, dated 07 / 22 / 2024, pp. 103 / 228 88 / 97 of the target user plane role after sending the first routing rule to the target user plane role entity. The second message is used to request the deletion of the second routing rule.

[00315] Optionally, the 1002 sending module is further configured to send a third message to the target user plane role entity after sending the first routing rule to the target user plane role entity. The third message is used to request the deletion of the first path information.

[00316] Optionally, the 1002 sending module is further configured to send a fourth message to the source user plane role entity after sending the first routing rule to the target user plane role entity. The fourth message is used to request the deletion of the user plane information, corresponding to the endpoint, in the source user plane role entity, and the user plane information includes the second path information.

[00317] Optionally, the 1002 sending module is further configured to send fifth path information to a target base station before the 1001 selection module selects the target user plane function entity to serve the terminal; and the 1002 sending module is further configured to send sixth path information to the source user plane function entity before the 1001 selection module selects the target user plane function entity to serve the terminal. The fifth path information and the sixth path information are used to establish a routing path between Petition 870240061722, dated 07 / 22 / 2024, pp. 104 / 228 89 / 97 the target base station and the source user plane function entity, the source user plane function entity is a user plane function entity currently establishing a first PDU session with the terminal, and the target base station is a base station currently communicatively connected to the target user plane function entity.

[00318] Optionally, selection module 1001 is specifically configured to: send a fifth message to the terminal, where the fifth message is used to request the establishment of a second PDU session; and select, in a process of establishing the second PDU session, the target user plane role entity to serve the terminal.

[00319] Optionally, the 1002 dispatch module is configured to send a sixth message to the endpoint after sending the first routing rule to the target user plane role entity. The sixth message is used to request the release of the first PDU session.

[00320] Optionally, the 1002 sending module is further configured to send a seventh message to the control device after sending the first routing rule to the target user plane function entity. The seventh message is used to request the switching of the terminal from the second AS to the first AS, and the second AS is the AS that is currently serving the terminal.

[00321] Optionally, the receiving module 1003 is further configured to receive an eighth message from the control device after the sending module 1002 sends the seventh message to the control device. The eighth Petition 870240061722, dated 07 / 22 / 2024, pp. 105 / 228 The 90 / 97 message is used to indicate that the terminal has been switched from the second AS to the first AS.

[00322] All related content from the steps in the previous method modalities can be cited in the function descriptions of the corresponding function modules, and the details are not described again here.

[00323] When each function module is obtained through division in an integrated manner, Figure 11 is a possible schematic structural diagram of the session management function entity 110 in the preceding embodiments. The session management function entity 110 includes a processing module 1101 and a communications module 1102. The processing module 1101 can be configured to perform an operation that can be performed by the selection module 1001 in Figure 10. The communications module 1102 can be configured to perform operations that can be performed by the reception module 1003 and the sending module 1002 in Figure 10. For details, refer to the embodiment shown in Figure 10. The details are not described again in this embodiment of this application.

[00324] All related content from the steps in the previous method modalities can be cited in the function descriptions of the corresponding function modules, and the details are not described again here.

[00325] In this embodiment, the session management function entity is presented in a form in which each function module is obtained by splitting based on each corresponding function, or the session management function entity is presented in a form in which each function module is obtained by splitting into a Petition 870240061722, dated 07 / 22 / 2024, pp. 106 / 228 91 / 97 integrated manner. The module in this document may be an application-specific integrated circuit (ASIC), a circuit, a processor and a memory that executes one or more software programs or firmware programs, an integrated logic circuit and / or other component that may provide the foregoing function. In a simple embodiment, a person skilled in the art may find that the session management function entity 100 or the session management function entity 110 may be in the form shown in Figure 4. For example, the selection module 1001, the sending module 1002 and the receiving module 1003 in Figure 10 may be implemented using the processor 401 and the memory 403 in Figure 4. Specifically, the selection module 1001, the sending module 1002 and the receiving module 1003 may be implemented using the processor 401 invoking the application program code stored in memory 403.This is not limited to this embodiment of this application. Alternatively, for example, processing module 1101 and communications module 1102 in Figure 11 can be implemented using processor 401 and memory 403 in Figure 4. Specifically, processing module 1101 and communications module 1102 can be implemented using processor 401, invoking the application program code stored in memory 403. This is not limited to this embodiment of this application.

[00326] The session management function entity provided in this modality of this request can be configured to perform the service continuity implementation method. Therefore, to achieve an effect Petition 870240061722, dated 07 / 22 / 2024, pp. 107 / 228 92 / 97 technical data that can be obtained from the session management function entity, see the method modalities above. Details are not described here again.

[00327] For example, when each function module is obtained by splitting based on each corresponding function, Figure 12 is a possible schematic structural diagram of the control device in the previous embodiments. The control device 120 includes a receiving module 1201 and a sending module 1202. The receiving module 1201 is configured to receive a first message from a session management function entity. The sending module 1202 is configured to send first AS indication information to the session management function entity. The first AS indication information is used to instruct the session management function entity to send a first routing rule to a target user plane function entity, and the first routing rule includes the data whose destination address is an address of the first AS is sent to the first AS.

[00328] Optionally, as shown in Figure 12, the control device 120 also includes a switching module 1203. The receiving module 1201 is further configured to: receive a seventh message from the session management function entity after the sending module 1202 sends the indication information of the first AS to the session management function entity. The seventh message is used to instruct to switch a terminal from a second AS to the first AS, and the second AS is an AS currently serving the terminal. The switching module 1203 Petition 870240061722, dated 07 / 22 / 2024, pp. 108 / 228 93 / 97 is configured to switch the terminal from the second AS to the first AS based on the seventh message.

[00329] All related content from the steps in the previous method modalities can be cited in the function descriptions of the corresponding function modules, and the details are not described again here.

[00330] When each function module is obtained by division in an integrated manner, Figure 13 is a possible schematic structural diagram of the control device 130 in the preceding embodiments. The control device 130 includes a communications module 1301. The communications module 1301 can be configured to perform operations that can be performed by the receiving module 1201 and the sending module 1202 in Figure 12. For details, refer to the embodiment shown in Figure 12. The details are not described again in this embodiment of this application.

[00331] Optionally, as shown in Figure 13, the control device 130 supplied in this embodiment of this application may also include a processing module 1302. The processing module 1302 may be configured to perform an operation that can be performed by the switching module 1203 in Figure 12. For details, see the embodiment shown in Figure 12. The details are not described again in this embodiment of this application.

[00332] All related content from the steps in the previous method modes can be cited in the function descriptions of the corresponding function modules, and the details are not described again here.

[00333] In this embodiment, the control device is presented in a form in which each function module is Petition 870240061722, dated 07 / 22 / 2024, pp. 109 / 228 94 / 97 obtained by division based on each corresponding function, or the control device is presented in a form where each function module is obtained by division in an integrated manner. The module in this document may be an application-specific integrated circuit (ASIC), a circuit, a processor and a memory that executes one or more software programs or firmware programs, an integrated logic circuit and / or other component that may provide the aforementioned function. In a simple embodiment, a person skilled in the art may find that the control device 120 or the control device 130 may be in the form shown in Figure 4. For example, the receiving module 1201, the sending module 1202 and the switching module 1203 in Figure 12 may be implemented using the processor 401 and the memory 403 in Figure 4.Specifically, the receiving module 1201, the sending module 1202, and the switching module 1203 can be implemented using processor 401 by invoking the application program code stored in memory 403. This is not limited in this embodiment of this application. Alternatively, for example, the processing module 1302 and the communications module 1301 in Figure 13 can be implemented using processor 401 and memory 403 in Figure 4. Specifically, the processing module 1302 and the communications module 1301 can be implemented using processor 401 by invoking the application program code stored in memory 403. This is not limited in this embodiment of this application.

[00334] The control device supplied in this embodiment of this application can be configured to perform Petition 870240061722, dated 07 / 22 / 2024, pp. 110 / 228 95 / 97 the service continuity implementation method. Therefore, for a technical effect that can be achieved by the control device, refer to the previous method modalities. The details are not described here again.

[00335] All or some of the foregoing embodiments may be implemented using software, hardware, firmware, or any combination thereof. When a software program is used to implement the embodiments, all or some of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or some of the procedures or functions according to the embodiments of this application are generated. The computer may be a general-purpose computer, a dedicated computer, a computer network, or other programmable devices. The computer instructions may be stored on a computer-readable storage medium or may be transmitted from one computer-readable storage medium to another computer-readable storage medium.For example, computer instructions can be transmitted from one site, computer, server, or data center to another site, computer, server, or data center in a wired manner (e.g., a coaxial cable, a fiber optic cable, or a digital subscriber line (DSL)) or wirelessly (e.g., infrared, radio, or microwave). Computer-readable storage media can be any usable media accessible by a computer or device. Petition 870240061722, dated 07 / 22 / 2024, pp. 111 / 228 96 / 97 data storage, such as a server or a data center, integrating one or more usable media. The usable media may be a magnetic medium (e.g., a floppy disk, a hard disk, or a magnetic tape), an optical medium (e.g., a DVD), a semiconductor medium (e.g., a solid-state drive (SSD)), or similar.

[00336] Although this application is described with reference to embodiments, in a process of implementing this application claiming protection, a person skilled in the art may understand and implement another variation of the disclosed embodiments by viewing the attached drawings, the disclosed content, and the attached claims. In the claims, understanding does not exclude another component or another step, and one or one does not exclude a plurality meaning. A single processor or other unit may implement several functions listed in the claims. Some measures are recorded in dependent claims that are different from each other, but this does not mean that these measures cannot be combined to produce a better effect.

[00337] Although this application is described with reference to specific features and embodiments thereof, obviously, various modifications and combinations may be made to the specific features and embodiments without departing from the spirit and scope of this application. Correspondingly, the specification and accompanying drawings are merely exemplary descriptions of this application, as defined by the appended claims, and are considered as one or all of the modifications, variations, combinations or Petition 870240061722, dated 07 / 22 / 2024, pp. 112 / 228 97 / 97 equivalents that encompass the scope of this application. Obviously, a person skilled in the art may make various modifications and variations to this application without departing from the spirit and scope of this application. This application is intended to cover such modifications and variations of this application, provided that such modifications and variations fall within the scope of protection defined by the following claims and their equivalent technologies. Petition 870240061722, dated 07 / 22 / 2024, pp. 113 / 228

Claims

1 / 7 CLAIMS 1. A method for implementing continuity of service applied when a terminal switches from a second application server, AS, to a first AS, characterized in that the method comprises: selecting (501), by a session management role entity, a target user plane role entity to serve a terminal; sending, by the session management role entity, first path information to the target user plane role entity; sending, by the session management role entity, second path information to a source user plane role entity communicatively connected to the second AS currently serving the terminal, wherein the first path information and the second path information are used to establish a forwarding path between the target user plane role entity and the source user plane role entity;send (502), by the session management function entity, a first message to a control device, wherein the first message comprises location information of the target user plane function entity and the location information of the target user plane function entity is used to determine that an AS to serve the terminal is the first AS; receive (503), by the session management function entity from the control device, information indicating the first AS; and Petition 870260029411, dated 30 / 03 / 2026, page 10 / 24 2 / 7 send (504), by the session management function entity, a first routing rule to the target user plane function entity based on the information indicating the first AS, wherein the first routing rule understands that data whose destination address is an address of the first AS is sent to the first AS.; 2. A method according to claim 1, characterized in that after selecting, by a session management role entity, the target user plane role entity to serve a terminal and before sending, by the session management role entity, the first routing rule to the target user plane role entity, it further comprises: sending, by the session management role entity, a second routing rule to the target user plane role entity, wherein the second routing rule comprises that data whose destination address is an address of the second AS is sent to the source user plane role entity, the second AS being an AS currently serving the terminal.

3. A method according to claim 2, characterized in that after the session management role entity sends the first routing rule to the target user plane role entity, it further comprises: sending, by the session management role entity, a second message to the target user plane role entity, wherein the second message is used to request the deletion of the second routing rule.

4. Method, according to claim 1, characterized in Petition 870260029411, dated 03 / 30 / 2026, page 11 / 24 3 / 7 by the fact that after sending, by the session management function entity, the first routing rule to the target user plane function entity, it further comprises: sending, by the session management function entity, a seventh message to the control device, wherein the seventh message is used to request switching the terminal from a second AS to the first AS.

5. Method according to claim 4, characterized in that after the session management function entity sends the seventh message to the control device, it further comprises: receiving, by the session management function entity, an eighth message from the control device, wherein the eighth message is used to indicate that the terminal has been switched from the second AS to the first AS.

6. Method, according to any one of claims 1 to 5, characterized in that the indication information of the first AS comprises location information of the first AS.

7. Session management function entity, characterized in that the session management function entity comprises a selection module, a sending module, and a receiving module; the selection module is configured to select a target user plane function entity to serve a terminal; the sending module is configured to: send first path information to the target user plane function entity; send second path information to a source user plane function entity connected communicatively to the second AS currently serving the terminal, wherein the first path information and the second path information are used to establish a forwarding path between the target user plane function entity and the source user plane function entity;Send a first message to a control device, wherein the first message comprises location information of the target user plane function entity, and the location information of the target user plane function entity is used to determine which AS to serve the terminal is the first AS; the receiving module is configured to receive first AS indication information from the control device; and the sending module is further configured to send a first routing rule to the target user plane function entity based on the first AS indication information, wherein the first routing rule understands that data whose destination address is an address of the first AS is sent to the first AS.

8. Session management function entity, according to claim 7, characterized in that the sending module is additionally configured to send a second routing rule to the target user plane function entity after the selection module selects the target user plane function entity to serve the endpoint and before the first routing rule is sent to the target user plane function entity, wherein the second routing rule comprises that data, whose destination address is an address of the second AS, is sent to the originating user plane function entity.

9. A method for implementing continuity of service, characterized in that the method comprises: receiving, by a control device, a first message from a session management function entity, wherein the first message comprises location information of a target user plane function entity; and sending, by the control device, in response to the first message, information indicating a first application server, AS, to the session management function entity, wherein the information indicating the first AS is used to instruct the session management function entity to send a first routing rule to the target user plane function entity, and the first routing rule comprises that data whose destination address is an address of the first AS is sent to the first AS.

10. Method according to claim 9, characterized in that it further comprises: determining, based on the location information of the target user plane function entity, which AS to serve the terminal is the first AS.

11. Method, according to claim 9, characterized in that after sending, by the control device, the information indicating the first AS to the session management function entity, it further comprises: receiving, by the control device, a seventh message from the session management function entity, wherein the seventh message is used to instruct to switch the terminal from a second AS to the first AS, and the second AS is an AS currently serving the terminal; and switching, by the control device, the terminal from the second AS to the first AS based on the seventh message.

12. Control device, characterized in that the control device comprises a receiving module and a sending module; the receiving module is configured to receive a first message from a session management function entity, wherein the first message comprises location information of a target user plane function entity; and the sending module is configured to, in response to the first message, send indication information of a first application server AS to the session management function entity, wherein the indication information of the first AS is used to instruct the session management function entity to send a first routing rule to the target user plane function entity, and the first routing rule comprises that data, whose destination address is an address of the first AS, is sent to the first AS.

13. Control device according to claim 12, characterized in that the control device further comprises a switching module; the receiving module is further configured to receive a seventh message from the session management function entity after the sending module sends the indication information of the first AS to the session management function entity, wherein the seventh message is used to instruct switching of a terminal from a second AS to the first AS, and the second AS is an AS currently serving the terminal; and the switching module is configured to switch the terminal from the second AS to the first AS based on the seventh message.

14. Service continuity implementation system, characterized in that it comprises a session management function entity, configured to execute the method as defined in any one of claims 1 to 6, and a control device, configured to execute the method as defined in any one of claims 9 to 11.

15. Computer-readable storage medium, characterized in that it comprises an instruction, wherein when the instruction is executed on a computer, the computer is enabled to perform the continuity of service implementation method as defined in any one of claims 1 to 6.

16. Computer-readable storage medium, characterized in that it comprises an instruction, wherein when the instruction is executed on a computer, the computer is enabled to perform the continuity of service implementation method as defined in any of claims 9 to 11. Petition 870260029411, dated 03 / 30 / 2026, pp. 16 / 24

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