A method for influencing data traffic routing in a core network

Abstract

The present disclosure relates to a method for implementing data traffic routing impact for a relocated application service in a core network of a communication system. In an embodiment, the core network may include a communication session control node and an application service node. The method may include: transmitting, by the communication session control node, a message for notifying a relocation triggering event to the application service node. The relocation triggering event triggers the application service node to relocate an application service provided to a user device in a pre-established communication session from a previous application hosting server to a new application hosting server outside the mobile core network. The method may also include: receiving, by the communication session control node, relocation information from the application service node, so that the communication session control node can reconfigure and modify the data traffic routing for the relocated application service.

Description

Technical Field

[0001] The present disclosure relates generally to mechanisms for influencing data traffic routing in a core communication network, and more particularly to mechanisms for enabling offloading of data traffic to application services when the application services are relocated. Background Art

[0002] A wireless or wired communication system may include a core network. The core network provides various network nodes for providing and routing data traffic between a user equipment (UE) and an application service. The application service may be hosted in an application server outside the core network. When the UE is far away from the application server, it is desirable that the application service be relocated to a new application server that hosts such application service and is geographically close to the UE. As such, the core network needs to affect new data traffic routing for offloading the UE data traffic to the new application server. Summary of the invention

[0003] The present disclosure relates to methods, systems, and devices for enabling offloading of data traffic to application services when the application services are relocated.

[0004] In one embodiment, a method performed in a mobile core network is disclosed. The mobile core network may include a communication session control node and an application service node. The method may include: transmitting, by the communication session control node, information for notifying a relocation triggering event to the application service node. The relocation triggering event triggers the application service node to relocate an application service provided to a user device in a pre-established communication session from a previous application hosting server to a new application hosting server outside the mobile core network. The method may also include: receiving, by the communication session control node, relocation information from the application service node. The relocation information may include a network address of the new application hosting server.

[0005] In another embodiment, a method performed in a mobile core network is disclosed. The mobile core network may include a communication session control node and an application service node. The method may include: receiving, by the application service node, a message from the communication session control node for notifying a relocation triggering event. The method may also include: in response to the relocation triggering event, relocating, by the application service node, an application service provided to a user device in a pre-established communication session from a previous application hosting server to a new application hosting server outside the mobile core network. The method may also include: transmitting, by the application service node, relocation information to the communication session control node. The relocation information may include a network address of the new application hosting server.

[0006] In another embodiment, a method performed in a mobile core network is disclosed. The mobile core network may include a communication session control node and an application service node. The method may include: in response to an application service provided to a user device in a pre-established communication session being relocated from a previous application hosting server to a new application hosting server outside the mobile core network, generating, by the application service node, a request for updating the application service relocation. The request may include a network address of the new application hosting server. The method may also include: transmitting, by the application service node, the request to the communication session control node.

[0007] In another embodiment, a method performed in a mobile core network is disclosed. The mobile core network may include a communication session control node and an application service node. The method may include: receiving, by the communication session control node, a request from the application service node to update an application service relocation, wherein the application service relocation is to relocate an application service provided to a user device in a pre-established communication session to a new application hosting server outside the mobile core network. The request includes a network address of the new application hosting server. The method may also include: transmitting, by the communication session control node, the network address of the new application hosting server to an intermediate user plane node.

[0008] In some other embodiments, one or more core network nodes may include one or more memories storing instructions and one or more processors communicating with the one or more memories. The one or more processors are configured to read instructions from the one or more memories to execute the above method.

[0009] In some other embodiments, a computer program product may include a non-transitory computer readable program medium having computer code stored thereon. The computer code, when executed by one or more processors, causes the one or more processors to perform the above method.

[0010] The above embodiments and other aspects as well as alternatives to their implementation are described in more detail in the following drawings, description and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 An example communication network system is shown that includes a carrier communication network including an access network and a core network.

[0012] Figure 2 An example core network is shown that supports the impact of data traffic routing.

[0013] Figure 3 An example wireless core network showing the impact of supporting data traffic routing.

[0014] Figure 4Example data and logic flows are shown for establishing and configuring network nodes for a communication session in a core network supporting data traffic routing effects.

[0015] Figure 5 Example data and logic flow for influencing data traffic routing for application services according to an embodiment are shown.

[0016] Figure 6 Depicted are example data and logic flows for affecting data traffic routing following relocation of an application service, according to an embodiment.

[0017] Figure 7 Depicted are example data and logic flows for affecting data traffic routing following relocation of an application service, according to an embodiment. DETAILED DESCRIPTION

[0018] like Figure 1 As shown in 100 in FIG. 1 , the communication network may include: user equipment (UE) 110 and UE 112, operator network 102, various application services 140 and other data networks 150. The operator network 102 may include, for example, an access network 120 and a core network 130. The operator network 102 may be configured to transmit voice, data and other information (collectively referred to as data traffic) between UE 110 and UE 112, between UE and application service 140, or between UE and other data networks 150. The access network 120 may be configured to interact with the UE on one side of the communication session and with the core network 130 on the other side. The core network 130 may include various network nodes configured to control the communication session and perform network access management and traffic routing. The application service 140 may be hosted by various application servers accessible to the UE through the core network 130 of the operator network 102. The application service 140 may be deployed as a data network outside the core network 130. Likewise, other data networks 150 may be accessed by the UE through the core network 130 and appear as a destination or source of data for a particular communication session instantiated in the operator network 102 .

[0019] Figure 1 The core network 130 may include various network nodes that are geographically distributed and interconnected to provide network coverage for the service area of ​​the operator network 102. These network nodes may be implemented as dedicated hardware network nodes. Alternatively, these network nodes may be virtualized and implemented as virtual machines or software entities. These network nodes may each be configured with one or more types of network functions that together provide the supply and routing functionality of the core network 130.

[0020] Figure 2 An example division of network node functions in the core network 130 is shown. Figure 2 Only a single instance of a network node for certain functions is shown, but a person skilled in the art will appreciate that each of these network nodes may be instantiated into multiple instances distributed throughout the core network 130. Figure 2 As shown, the core network 130 may include but is not limited to: an access management network node (AMNN) 230, a session management network node (SMNN) 240, a data routing network node (DRNN) 250, a policy control network node (PCNN) 220, and an application data management network node (ADMNN) 210.

[0021] The access management network node 230 communicates with the access network 120, the session management network node 240, and the policy control network node 220 via the communication interfaces 122, 232, and 224, respectively, and may be responsible for providing UE registration, authentication, and access to the core network 130, as well as the allocation of the session management network node 240 to support specific UE communication requirements. The session management network node 240 allocated by the access management network node 230 may in turn be responsible for allocating data routing network nodes 250 for supporting specific UE communication requirements, and controlling these allocated data routing network nodes 250 via the communication interface 246. Alternatively or additionally, in some embodiments, the data routing network node 250 may be directly allocated by the access management network node 230 via the interface 234, and controlled by the session management network 242 via the communication interface 246. The access policy and session routing policy applicable to the UE may be managed by the policy control network node 220, which transmits the policy to the access management network node 230 and the session management network node 240 via communication interfaces 224 and 222, respectively. Figure 2 The various communication interfaces indicated by the various connection lines in the figure, the signaling and data exchange between the various types of network nodes can be carried by signaling or data messages that follow a predefined type of format or protocol.

[0022] In order to support a specific end-to-end communication task requested by the UE, a communication session may be established to support a data traffic pipe for transmitting specific end-to-end communication data traffic. Figure 2As shown in 270, the operator network portion of the data traffic pipe may include one or more network nodes in the access network 120 and a set of data routing network nodes 252, 254, and 256 in the core network 130, which are selected and controlled by, for example, a set of session management network nodes 242 and 244, which may be selected and controlled by the access management network node 230 responsible for establishing and managing communication sessions. Data traffic is routed between the UE at one end of the data traffic pipe, the operator network portion of the data traffic pipe (including the set of network nodes in the access network 120 and the selected data routing network nodes 252, 254, and 256 in the core network 130), and the other end of the data traffic pipe (including, for example, another UE, an application server 140, or another data network 150) via communication interfaces such as 124, 258, and 259.

[0023] For some communication sessions, data transmitted in the core network 130 may terminate at an application server 140 that hosts an application service. In other words, the application server 140 may be the destination of data traffic routed in the core network 130. Likewise, the application server 140 may also be the source of data traffic to be routed to other destinations by the core network 130. In such a communication session, the application server 140 may be accessed by the operator network portion 270 of the data traffic pipe for the communication session, as shown by 259.

[0024] The application server 140 may also transmit other configuration and control information to the core network 130. The information transmitted to the core network 130 may be referred to as application data. Such application data may be processed and managed by a specific type of network node, which may be in the form of a Figure 2 The application data may be transmitted from the application server 140 to the application data management network node 210 via the communication interface 214, for example, in a message. Alternatively, the application server 140 may access the application data management network node 210 using an open API provided by the core network 130. Figure 2 Only a single application server is shown, but those skilled in the art will appreciate that in actual implementations, the core network 130 may support a variety of different types of application services.

[0025] Above Figure 1 and Figure 2 The embodiments described in the specification are applicable to both wireless and wired communication systems. For wireless communication systems, the access network 120 will be implemented as a radio access network (RAN) distributed in the service area of ​​the operator network 102, for example.

[0026] Figure 3An example wireless communication network 300 is shown in which embodiments of the present disclosure may be implemented. Figure 3 As shown, the wireless communication network 300 may include: UE 310, local data network 340, central data network 350, and operator networks including RAN 322, RAN 324, and core network 330. Figure 3 Only a single instance of a network node used for some functions of the wireless network 300 and the core network 330 is shown, but one of ordinary skill in the art understands that each of these network nodes may have multiple instances distributed throughout the wireless communication network 300 .

[0027] For example, RAN 322 and 324 may include multiple wireless base stations such as wireless base stations implemented in various generations of cellular wireless networks. For example, the wireless base stations may include: 4G LTE base stations, 5G New Radio (NR) base stations, 5G centralized cell base stations, and 5G distributed cell base stations.

[0028] UE 310 may be implemented as various types of mobile devices configured to communicate with RAN 322 and 324 via an over-the-air (OTA) communication channel. UE 310 may include, but is not limited to, a mobile phone, a laptop computer, a tablet computer, an Internet of Things (IoT) device, a distributed sensor network node, a wearable device, etc.

[0029] like Figure 3 As shown, the core network 330 may include: application function (AF) 332, network exposure function (NEF) 335 and unified data repository (UDR) function 336. The network "nodes" in the core network 330 are also referred to as network "functions" in this article. These three types of network nodes can act together Figure 2 The core network 330 may also include an access and mobility management function (AMF) 339 and a session management function (SMF) 331. AMF and SMF act as Figure 2 The access management network node (AMNN) 230 and the session management network node (SMNN) 240 of the SMF 331 can obtain communication policy information from the policy control function (PCF) 334. The PCF 334 acts as Figure 2 The policy control network node (PCNN) 220.

[0030] like Figure 3As further shown, SMF 331 controls a plurality of user plane functions (UPFs) 337 and 338a-338c. RAN 322 and 324 and one or more UPFs may be allocated by the core network and form the operator network portion of the data traffic pipe (or alternatively, the data traffic path) for a particular communication session. UPFs 337 and 338a-338c act as Figure 2 The data routing network node (DRNN) 250. The user planning function may include: one or more packet data unit (PDU) session anchor UPF (PSA / UPF) 338a-338c and one or more intermediate UPF (I-UPF) 337, as will be described in more detail below.

[0031] like Figure 3 As shown, application servers 342, 346, and 348 are deployed in local data network 340, and application server 352 is deployed in central data network 350. These application servers can be connected to a separate PSA / UPF of core network 330 to transmit data traffic between the application servers and core network 330. PSA / UPF can be connected to one or more application servers. Figure 3 As shown, PSA / UPF 338a is connected to application server 352; PSA / UPF 338b is connected to application servers 342 and 346; and PSA / UPF 338c is connected to application server 348.

[0032] Figure 3 The various network nodes or network functions in the network use signaling or data messages that follow a predefined type of format or protocol, such as Figure 3 Various communication interfaces indicated by various connection lines in the communication network are used to transmit signaling information and data. Some example communication interfaces defined in, for example, the fifth generation new air interface wireless communication specification can be used between various network nodes in the communication network 300, such as Figure 3 As indicated by the labels along the connection lines, the example communication interfaces include an N1 interface between UE 310 and AMF339, an N2 interface between RAN 322, 324 and AMF 339, an N3 interface between RAN 322, 324 and I-UPF 337, an N4 interface between SMF 331 and I-UPF 337, an N6 interface between PSA / UPF 338a-338c and application servers 342, 346, 348 and 352, and an N11 interface between AMF 339 and SMF 331.

[0033] The following describes in more detail Figure 3 3. An example of the functionality of various network nodes and network functions in the wireless communication network 300.

[0034] 1) AMF (Access and Mobility Management Function) 339. The functionality performed by these network nodes includes, but is not limited to, registration management, connection management, reachability management, and mobility management of UE 310. These network nodes also perform access authentication and access authorization. AMF 339 can serve as a non-access stratum (NAS) security terminal and relay session management NAS messages between UE 310 and SMF 331.

[0035] 2) SMF (Session Management Function) 331. The functionality performed by these network nodes includes, but is not limited to, establishment, modification and release of communication sessions, UE Internet Protocol (IP) address allocation and management (including optional authorization functions), selection and control of PSA / UPF 338a-338c, and downlink data notification.

[0036] 3) UPF (User Plane Function) 337 and 338a-338c. The functionality performed by these network nodes includes, but is not limited to, acting as an anchor point for intra / inter-radio access technology (RAT) mobility, packet routing and forwarding, traffic usage reporting, user plane quality of service (QoS) processing, downlink packet caching, and downlink data notification triggering. UPF can be deployed as I-UPF and PSA / UPF. PSA / UPF is the UPF that terminates the N6 interface to the data network. I-UPF provides traffic forwarding between RAN and PSA / UPF. I-UPF can support uplink classifier (ULCL) or branch point (BP) to offload some data traffic to the local PSA / UPF. ULCL offloads uplink traffic based on the target IP address of the traffic. BP offloads uplink traffic based on the source IP address of the traffic.

[0037] 4) PCF (Policy Control Function) 334. The functionality performed by these network nodes includes, but is not limited to, providing policy rules and controlling the UPF to enforce policy rules. Specifically, the PCF 334 converts application function (AF, see below) requests into policies applied to PDU sessions. The PCF 334 provides traffic steering enforcement control affected by the AF to the SMF 331 in the Policy Control and Charging (PCC) rules, so that the SMF 331 can establish a data path to offload traffic to the local data network 340, as will be described in more detail below.

[0038] 5) UDR (Unified Data Repository) 336. These network nodes can support but are not limited to storing and retrieving structured data for network opening, application data such as AF request information of multiple UEs, etc. When application data is updated, the UDR can send a notification to the PCF 334 if the PCF 334 has signed up for the change. The PCF can also retrieve application data from the UDR 336.

[0039] 6) NEF (Network Exposure Function) 335. These network nodes can store and retrieve information as structured data using a standardized interface (e.g., Nudr interface) to UDR 336. NEF 335 can provide a means for AF 332 (see below) to securely provide various information to the core network 330, including but not limited to information about the impact of applications on data traffic routing. NEF 335 can authenticate, authorize, and assist in throttling requests from AF 332.

[0040] 7) AF (Application Function) 332. These network nodes can interact with the core network 330 to serve application services, such as supporting the impact of applications on data traffic routing. AF 332 can interact with application services on one end and interact with network functions in the core network 330 via NEF 335 on the other end. In some embodiments, AF 332, which is considered trusted by the core network 330, can bypass NEF 335 and interact directly with other relevant network functions in the core network 330.

[0041] The above described and Figure 3 The various network nodes or functions depicted may be configured to enable offloading of data traffic to application services in the core network 330 in a coordinated manner.

[0042] Figure 4 An example data and logic flow 400 is shown for establishing and configuring network nodes in the core network 330 for a new PDU session when the UE 310 accesses the core network 330 via the RAN 322. The example data and logic flow 400 may include the following steps.

[0043] 1. To establish a new PDU session, the UE 310 generates a new PDU session ID. The UE 310 sends a PDU session establishment request 402 to the AMF 339 via the RAN 322. For example, the request may be carried by a non-access stratum (NAS) message between the core network and the UE 310. The message may include information such as a data network name (DNN), a new PDU session ID, and a PDU session establishment request. In some embodiments, the PDU session establishment request is encapsulated in a session management (SM) container for transporting N1.

[0044] 2. AMF 339 selects SMF 331 based on the requested DNN. Then, AMF 339 sends an M-context creation request message 404 to SMF 331, which is used to request the creation of an SM context S for the new PDU session. The SM context creation message 404 may, for example, include information such as a subscription permanent identifier (SUPI), a DNN, a PDU session ID, an AMF ID, and an N1 SM container containing the PDU session establishment request 402. SUPI uniquely identifies the UE subscription. The AMF ID is the UE's globally unique AMF ID (GUAMI), which uniquely identifies the AMF serving the UE.

[0045] 3. Upon receiving the SM context creation request message 404 from AMF 339, if SMF 331 is able to process the PDU session establishment request, SMF 331 creates an SM context and sends a response message 406 including an SM context identifier to AMF 339.

[0046] 4. SMF 331 determines that PCC authorization is required and requests establishment of an SM policy associated with PCF 334 by sending a policy control create request message 408 to PCF 334 .

[0047] 5. PCF 334 performs authorization based on UE subscription and local configuration, and responds to policy control creation request 408 from SMF 331 by sending policy control response 410 to SMF 331. In its response, PCF 334 may provide PCC rules to SMF 331 so that SMF 331 may execute the PCC rules.

[0048] 6. SMF 331 selects PSA / UPF 338a based on DNN. SMF 331 then sends N4 session establishment request message 412 to PSA / UPF 338a. N4 session establishment request message 412 may include packet detection, execution and reporting rules to be installed on PSA / UPF 338a for the PDU session. If core network (CN) tunnel information is allocated by SMF 331, session establishment request message 412 may also include CN tunnel information.

[0049] 7. Upon receiving the N4 Session Establishment Request message 412, the PSA / UPF 338a acknowledges by sending an N4 Session Establishment Response message 414 to the SMF 331. If the CN tunnel information is allocated by the PSA / UPF 338a, the Session Establishment Response message 414 may include the CN tunnel information.

[0050] 8. SMF 331 then sends a transmission request message 416 to AMF 339. The transmission request message 416 may include, for example, information such as a PDU session ID, information about the communication interface between AMF 339 and RAN 322 (e.g., Figure 3 The N2 information may include information about the N2 interface in the UE 310 and information parameters such as the N1 SM container. For example, the N2 information may include a PDU session ID, CN tunnel information, a QoS profile, and a corresponding QoS flow identifier. The N1 SM container may include a PDU session establishment accept message that the AMF 339 should provide to the UE 310.

[0051] 9. AMF 339 via e.g. Figure 3 The N2 interface is shown sending a session access request 418 for the PDU session to the RAN 322. The session access request 418 may, for example, include information such as N2 SM information, a NAS message including information such as a PDU session ID, and an N1 SM container containing a PDU session setup accept message.

[0052] 10. As Figure 4 As indicated by 420, RAN 322 issues access network specific signaling exchanges with UE 310 for UE session configuration related to the information received from SMF 331. For example, in the case of a new air interface RAN, a radio resource control (RRC) connection reconfiguration may be performed with the UE for establishing the necessary new air interface RAN resources related to the QoS rules of the session access request 418. RAN 322 may also allocate tunnel information for the PDU session. RAN 320 may also forward the NAS message provided in step 9 above to UE 310.

[0053] 11. Then, RAN 322 sends a session access response message 422 to AMF 339 in response to the session access request 418 in step 9 above. The session access response message may, for example, include information such as PDU session ID, cause, and N2 SM information, which may include PDU session ID, access network tunnel information, and accepted / rejected QFI list. The access network tunnel information corresponds to the access network address of the tunnel corresponding to the PDU session.

[0054] 12. The AMF 339 then sends a context update request message 424 to the SMF 331. The context update request message 424 may include information such as N2 SM information, for example. For example, the AMF 339 may forward the N2 SM information received from the RAN 322 to the SMF 331. If the rejected QFI list is included in the N2 SM information, the SMF 331 will release the rejected QoS profile associated with the QFI.

[0055] 13. Then, SMF 331 initiates the N4 session modification process with PSA / UPF 338a, and sends the access network tunnel information and corresponding forwarding rules to PSA / UPF338a.

[0056] At this point, the PDU session is successfully established, and the UE 310 can use the established user plane for uplink and downlink data transmission to the application server 352 in the central data network 350 .

[0057] Figure 5 An example data and logic flow 500 is shown for offloading UE data traffic to an anchor UPF connected to an application server in a local data network 340 instead of a central data network 350. The example data and logic flow 500 may include the following steps.

[0058] 1. As Figure 5 As shown, AF 332 sends a data traffic routing impact request 502 to PCF 334 via NEF 312. In some implementations, AF 332 may send data traffic routing impact request 502 directly to PCF 334. The information content of data traffic routing impact request 502 may include, for example:

[0059] a. Information about identifying data traffic. For example, the information may include, for example, a target DNN and possible slice information (S-NSSAI). Alternatively, the information may include, for example, an AF service identifier, i.e., an identifier of the application service on whose behalf the AF 332 makes the request. When the AF service identifier is included in the information, the NEF 332 maps it to the target DNN and S-NSSAI. Additionally, the information may include an application identifier or traffic filtering information. The application identifier refers to the application service that handles user plane traffic and is used by the UPF to detect traffic from the application service.

[0060] b. Information about N6 data traffic routing requirements for the data traffic identified above. This information may include, for example, a routing profile ID for each DNAI for the data traffic. Alternatively or additionally, this information may include N6 data traffic routing information for each DNAI.

[0061] c. Information about potential locations of application services to which traffic routing should be applied. This information may, for example, include a list of DNAIs available for selection by the UPF.

[0062] d. Information identifying the UE to which the request 502 is directed. The UE may include an individual UE, and the individual UE may be identified by a general public subscription identifier (GPSI), an IP address, an IP prefix, or a media access control (MAC) address. If the UE is identified by a GPSI, the GPSI may be mapped to a SUPI based on the subscription information received from the UDM. In some embodiments, the UE may include one or more groups of UEs. When the AF 332 interacts with the PCF 334 via the NEF 335, each group of UEs may be identified by an external group identifier. When the AF 332 interacts directly with the PCF 334, each group of UEs may be identified by an internal group identifier. In some embodiments, the UE may include a specific type of UE, such as all UEs that access a combination of a DNN, S-NSSAI, and DNAI. When the request 502 targets a specific type of UE or UE group, the request 502 may affect multiple PDU sessions that may be served by multiple SMFs and PCFs.

[0063] e. Indication of application service relocation possibility. This indicates whether the application service can be relocated once the location of the application service is selected by the core network 330. If application service relocation is not possible, the core network 330 will ensure that the data network access identifier (DNAI) used for traffic related to the application service will not be changed once it is selected for the application service.

[0064] f. Information about the subscription from AF 332 to the relevant SMF event. AF 332 can subscribe to a change of the user plane path that is associated with the data traffic identified in request 502. The information about the subscription may include the type of subscription, such as a subscription for early notification or delayed notification. In the case of signing up for early notification, SMF 331 sends the notification before the new user plane path is configured. In the case of signing up for delayed notification, SMF 331 sends the notification after the new user plane path has been configured. Optionally, the information about the subscription may also include an indication suggesting that AF 332 will provide a response to the notification of the user plane path management event to the core network 330. Based on the indication, SMF 331 may determine to wait for a response from AF 332 before it activates the new user plane path.

[0065] 2. If Figure 5 As shown in 504, NEF 335 ensures necessary authorization control, performs throttling on requests from AF 332, and maps request information provided by AF to information identified by the core network (e.g., as described above, from AF service identifier to DNN and S-NSSAI or from external group identifier to internal group identifier). NEF 312 stores the request information in UDR 336.

[0066] 3. Such as Figure 5 As shown in 506, PCF 334, which subscribes to notifications from UDR 336, receives notifications of application data changes from UDR 336 and may store the notification data locally.

[0067] 4. Such as Figure 5 As shown in 508 , the NEF 335 responds to the AF 332 to acknowledge receipt of the data traffic routing influence request 502 .

[0068] 5. Once the PCF 334 is notified of the new data traffic routing impact request, it determines whether the existing established PDU session is potentially affected or implicated by the new request. Specifically, the PCF 334 updates the SMF 331 associated with the existing communication session with the corresponding new PCC rule by sending a notification message 510. The notification message 510 may include: information identifying the PDU session, information identifying the traffic that needs to be offloaded, and DNAI information identifying which anchor UPF the traffic should be offloaded to. In addition, if the data traffic impact request 502 includes a notification reporting request for a user plane path change, the PCF 334 may include the information required to report the event in the PCC rule, and the required information includes a notification target address pointing to the NEF 335 and a notification correlation ID containing an AF transaction internal ID.

[0069] 6. Upon receiving the notification message 510 from the PCF 334, the SMF 331 performs anchor UPF selection to select, for example, the PSA / UPF 338b based on the DNAI and the network address requested by the UE 310 included in the notification message 510. For example, the PSA / UPF 338b is selected because the PSA / UPF 338b is geographically close to the UE 310. The SMF may also select an I-UPF 337 capable of performing ULCL or BP to offload traffic to the PSA / UPF 338b. Due to the geographical proximity between the UE 310 and the PSA / UPF 338b, data traffic transmission efficiency can be achieved.

[0070] 7. Such as Figure 5 As shown, SMF 331 then sends a PDU session establishment request 512 to I-UPF 337, which is intended to establish a PDU session with I-UPF 337. If the core network tunnel information of the PDU session is allocated by SMF 331, the request 512 may include the core network tunnel information. Optionally, the request 512 may include a traffic filter that is subject to offloading. I-UPF 337 may use the traffic filter to identify the data packet and forward the data packet to the local data network 340.

[0071] 8. As Figure 5As shown in 514 in FIG. 5 , the I-UPF 337 responds to the SMF 331 to confirm the receipt of the PDU session establishment request 512. If the core network tunnel information for the PDU session is allocated by the I-UPF 337, the tunnel information may be provided to the SMF 331 in the response.

[0072] 9. As Figure 5 As shown in 516 in FIG, SMF 331 sends a transmission request message to AMF 339. The transmission request message may, for example, include a PDU session ID and N2 SM information. The N2 SM information carries information that AMF 516 will forward to RAN 322, which may, for example, include N3 core network tunnel information of I-UPF 337.

[0073] 10. As Figure 5 As shown in 518 in FIG, AMF 339 sends a PDU session request to RAN 322. The PDU session request may, for example, include the N2 SM information received from SMF 331.

[0074] 11. As Figure 5 As shown in 520, RAN 322 sends a PDU session response to AMF 339. The PDU session response may, for example, include a PDU session ID and N2 SM information. The N2 SM message information carries information that AMF 339 will forward to SMF 331, which may, for example, include a PDU session ID and a cause.

[0075] 12. If Figure 5 As shown in 522, AMF 339 sends a PDU session SM context update request to SMF 331. The request may include the N2 SM information received from RAN 322.

[0076] 13. As Figure 5 As shown in 524 in, upon receiving the PDU session SM context update request 522 from AMF 339, SMF 331 sends an N4 session establishment request to PSA / UPF 338b. The request may, for example, include N9 tunnel information of I-UPF 337.

[0077] 14. As Figure 5 As shown in 526 in , PSA / UPF 338b responds to SMF 331 to confirm receipt of the session establishment request 524.

[0078] 15. As Figure 5 As shown in 528, SMF 331 sends an N4 session modification request to PSA / UPF 338a. The request may include, for example, N9 tunnel information of I-UPF 337.

[0079] 16. As Figure 5 As shown in 530 in FIG. 5 , PSA / UPF 338a responds to SMF 331 to confirm receipt of session modification request 528.

[0080] 17. As Figure 5 As shown in 532, SMF 331 also sends a session modification request to I-UPF 337. The request may, for example, include N9 tunnel information of PSA / UPF 338b.

[0081] 18. As Figure 5 As shown in 534 in FIG. 5 , the I-UPF 337 responds to the SMF 331 to confirm receipt of the session modification request 532 .

[0082] After these steps, I-UPF 337 may perform ULCL or BP to offload UE data traffic to PSA / UPF 338b. PSA / UPF 338b may also transmit the offload traffic to application server 342 in local data network 340 via N6. Application server 342 hosts application services provided to UE 310.

[0083] When the UE 310 roams within the wireless communication network 300, for example, when the UE 310 moves from the RAN 322 to the RAN 324, the UE data traffic offloading to the application server 342 via the PSA / UPF 338b may not be optimized because the PSA / UPF 338b is geographically close to the RAN 322 but far away from the RAN 324. In this case, it is desirable to offload the data traffic of the UE 310 to a PSA / UPF (e.g., PSA / UPF 338c) that is close to the RAN 324. To this end, the application service provided to the UE 310 needs to be relocated from the application server 342 to the application server 348 connected to the PSA / UPF 338c, so that the data traffic of the UE 310 can be switched to be offloaded to the application server 348 via the PSA / UPF 338c.

[0084] Figure 6 and 7 Provided in Figure 3 In a communication system 300 of the present invention, example data and logic flows for implementing a UE data traffic offload handover to a new application server after an application service provided to the UE is relocated to the new application server. Although these flowcharts are discussed in the context of a specific example wireless communication network 300, the underlying principles are applicable to other wireless and non-wireless communication networks.

[0085] In an embodiment, SMF 331 may send a relocation trigger event to AF 332, which may trigger AF 332 to relocate the application service to a new application server and return the relocation information to SMF 331. Using the relocation information, SMF 331 may configure a data traffic offload path to the new application server hosting the application service.

[0086] Figure 6 An example data and logic flow for implementing data traffic offloading to a new application server according to this embodiment is provided. The data and logic flow 600 includes example steps numbered 1 to 11. Also refer to Figure 3 The network functions or nodes in the example data and logic flow 600 may include the following steps.

[0087] 1. When SMF 331 detects a relocation triggering event related to an application service, SMF 331 may send a notification of the relocation triggering event to AF 332 via NEF 335. Specifically, SMF 331 sends a notification of the relocation triggering event to NEF 335, such as Figure 6 602 in . In some embodiments, the relocation triggering event may, for example, include that a communication session anchor point (e.g., PSA / UPF) has been established or released, and that the DNAI for the PDU session between the UE and the PSA / UPF has changed. The notification of the relocation triggering event may include a list of target DNAIs supported by the SMF 331. Optionally, the notification of the relocation triggering event may also include location information of the UE 310 such as the cell ID of the cell in which the UE is currently located.

[0088] 2. After receiving the notification of the relocation triggering event from SMF 331, NEF 335 performs information mapping (if applicable). For example, the AF transaction internal ID provided in the notification correlation ID of the notification is mapped to the AF transaction external ID, and the SUPI in the notification is mapped to the GPSI. NEF 335 then forwards the mapped notification of the relocation triggering event to AF 332, as shown in FIG. Figure 6 As shown in 604.

[0089] 3. Alternatively, SMF 331 may directly send a notification of a relocation triggering event to AF 332 bypassing NEF 335. Specifically, SMF 331 directly sends a notification of a relocation triggering event to AF 335, such as Figure 6 As shown in 606.

[0090] 4. Such as Figure 6As shown in 608 in , based on the notification, AF 332 performs relocation for the application service. In some embodiments, AF 332 can perform relocation for the application service based on the location information of the UE. For example, AF 332 relocates the application service to application server 348 because application server 348 is geographically closer to UE 310. As a result, a shorter data traffic routing path can be achieved between UE 310 and the application service, thereby improving the service efficiency with respect to UE 310. Then, AF 332 can determine the target DNAI that identifies the PSA / UPF (e.g., PSA / UPF338c) connected to application server 348. AF 332 can also determine the corresponding N6 data traffic route between PSA / UPF 338c and application server 348, and the uplink data traffic can reach application server 348 via this route.

[0091] 5. In response to the notification of the relocation trigger event sent in steps 1 and 2, AF 332 may send application service relocation information to SMF 331 via NEF 335. Specifically, AF 332 sends relocation information to NEF 335, such as Figure 6 610 in . The relocation information may, for example, include a target DNAI identifying the PSA / UPF 338c and a corresponding N6 data traffic route between the PSA / UPF 338c and the application server 348. In addition, in order to enable offloading of data traffic to the PSA / UPF 338c, the AF 332 may provide the network address of the application server 348 to the SMF 331 in the relocation information. For example, the relocation information may include traffic filtering information (e.g., a 5-tuple) containing the network address of the application server 348. The network address of the application server 348 may, for example, be an IP address or a MAC address.

[0092] 6. When NEF 335 receives relocation information from AF 332, NEF may trigger forwarding of the relocation information to SMF 331, e.g. Figure 6 As shown in 612.

[0093] 7. Alternatively, as a response to the notification of the relocation triggering event sent in step 3, AF 332 may directly send relocation information about the application service to SMF 331, such as Figure 6 As shown in 614.

[0094] 8. Upon receiving the relocation information directly from AF 332 or indirectly from NEF 335, SMF 331 may reselect PSA / UPF 338c according to the target DNAI in the relocation information. SMF 331 may then send an N4 session establishment request message to PSA / UPF 338c, such as Figure 6 As shown in 616 in FIG. , this can be used with reference to Figure 4 The N4 session establishment request message may be performed in a similar manner to step 6 in the process 400. The N4 session establishment request message may, for example, include the N9 tunnel information of the I-UPF 337. If the SMF 331 allocates a new network address (e.g., an IPv6 address / prefix) to the UE 310, the N4 session establishment request message may also include the new network address / prefix of the UE 310.

[0095] 9. As Figure 6 As shown in 618 in FIG. 1 , PSA / UPF 338c responds to SMF 331 to confirm receipt of the N4 session establishment request message, which can be used with reference to Figure 4 The response message may be performed in a similar manner to step 7 in process 400. If PSA / UPF 338c allocates a new network address (eg, IPv6 address / prefix) to UE 310, the response message may include the new network address / prefix of UE 310.

[0096] 10. In addition, the SMF 331 sends an N4 Session Modification Request message to the I-UPF 337. The N4 Session Modification Request message may, for example, include the N9 tunnel information of the PSA / UPF 338c. In order to enable the uplink traffic to be offloaded to the PSA / UPF 338c in ULCL mode, the SMF 331 may provide the I-UPF 337 with, for example, traffic filtering information including the network address of the application server 348 in the N4 Session Modification Request message. In order to enable the uplink traffic to be offloaded to the PSA / UPF 338c in BP mode, the SMF 331 may provide, for example, traffic filtering information including the new IPv6 address / prefix of the UE 310 in the N4 Session Modification Request message. Alternatively, the SMF 331 may provide, for example, the new IPv6 address / prefix of the UE 310 and a rule for routing to the UE 310 in the N4 Session Modification Request message. The routing rule may, for example, include the network address of the application server 338c to which the application service is relocated.

[0097] 11. Based on the N4 session modification request message received from SMF 331, I-UPF 337 updates its forwarding rules for data traffic of UE 310 so that the data traffic of UE can be offloaded to PSA / UPF 338c. Then, I-UPF 337 may respond to SMF 331 to confirm receipt of the N4 session modification request message, such as Figure 6 As shown in 622.

[0098] After these steps, I-UPF 337 may perform ULCL or BP to offload UE data traffic to PSA / UPF 338c. PSA / UPF 338c may also transmit the offloaded traffic to application server 348 in local data network 340 via N6 interface.

[0099] In another embodiment, AF 332 may also initiate application service relocation by detecting a relocation triggering event by itself (e.g., detecting that UE 310 roams from RAN 322 to RAN 324), rather than receiving a notification of a relocation triggering event to trigger application service relocation. In this way, after relocating the application service provided to UE 310 to a new application server, AF 332 may send an update notifying application service relocation to core network 330, so that data traffic of UE 310 can be offloaded to the new application server.

[0100] Figure 7 An example data and logic flow for implementing data traffic offloading to a new application server according to this embodiment is provided. The data and logic flow 700 includes example steps numbered 1 to 9. Also refer to Figure 3 The network functions or nodes in the example data and logic flow 700 may include the following steps.

[0101] 1. After relocating the application service provided to UE 310 to application server 348, AF 332 may send a relocation update request message to PCF 334 via NEF 335. Specifically, AF 332 sends a relocation update request message to NEF 335, such as Figure 7702 in . Alternatively, AF 332 may send a relocation update request message directly to PCF 334. The update request message may, for example, include a target DNAI identifying PSA / UPF 338c connected to PSA / UPF 338c, and a corresponding N6 data traffic route between PSA / UPF 338c and application server 348. In addition, in order to be able to offload data traffic to PSA / UPF 338c, AF 332 may provide the network address of application server 348 to PCF 334 in the relocation update request message. For example, the relocation update request message may include traffic filtering information (e.g., a 5-tuple) containing the network address of application server 348. The network address of application server 348 may, for example, be an IP address or a MAC address.

[0102] 2. When NEF 335 receives the relocation update request message from AF 332, NEF 335 ensures that the relocation update request has the necessary authorization in core network 300, and maps the information in the relocation request message to the required information in core network 300. For example, the AF transaction internal ID provided in the update request message is mapped to the AF transaction external ID, and the SUPI in the update request message is mapped to the GPSI. NEF 335 can then find the address of the PCF corresponding to the relocation update request in its local configuration. If the address of the PCF is not available locally, NEF 335 can send a discovery request for the PCF address to the binding support function (BSF), such as Figure 7 As shown in 704 in FIG.

[0103] 3. Based on the address of UE 310 in the discovery request, the BSF finds the address of the PCF (e.g., PCF 334) corresponding to UE 310. The BSF then sends a discovery response including the address of PCF 334 to NEF 335, such as Figure 7 As shown in 706.

[0104] 4. After obtaining the address of PCF 334, NEF 335 sends the mapped relocation update request message to PCF 334, such as Figure 7 Optionally, PCF 334 may respond to NEF 335 to confirm receipt of the update request message.

[0105] 5. As Figure 7 As shown in 710 in FIG. 1 , PCF 334 sends an update message notifying relocation to SMF 331, which can be used in conjunction with reference to FIG. Figure 5The update message may be performed in a similar manner to step 5 of process 500. The update message may, for example, include relocation information such as new PCC rules corresponding to the relocation.

[0106] 6. Upon receiving the update message notifying the relocation from PCF 334, SMF 331 may reselect PSA / UPF 338c according to the target DNAI in the relocation information. SMF 331 may then send an N4 session establishment request message to PSA / UPF 338c, such as Figure 7 As shown in 712, this can be used with reference Figure 4 The N4 session establishment request message may be performed in a similar manner to step 6 in the process 400. The N4 session establishment request message may, for example, include the N9 tunnel information of the I-UPF 337. If the SMF 331 allocates a new network address (e.g., an IPv6 address / prefix) to the UE 310, the N4 session establishment request message may also include the network address of the UE 310.

[0107] 7. Such as Figure 7 As shown in 714 in FIG. 1 , PSA / UPF 338c responds to SMF 331 to confirm receipt of the N4 session establishment request message, which can be used with reference to Figure 4 The response message may be performed in a similar manner to step 7 in process 400. If PSA / UPF 338c allocates a new network address (eg, IPv6 address / prefix) to UE 310, the response message may include the new network address / prefix of UE 310.

[0108] 8. In addition, SMF 331 sends an N4 session modification request message to I-UPF 337, such as Figure 7 716 in . The N4 session modification request message may, for example, include the N9 tunnel information of the PSA / UPF 338c. In order to enable the uplink traffic to be offloaded to the PSA / UPF 338c in ULCL mode, the SMF 331 may provide the I-UPF 337 with traffic filtering information, for example, including the network address of the application server 348, in the N4 session modification request message. In order to enable the uplink traffic to be offloaded to the PSA / UPF 338c in BP mode, the SMF 331 may provide traffic filtering information, for example, including the new IPv6 address / prefix of the UE 310, in the N4 session modification request message. Alternatively, the SMF 331 may provide, for example, the new IPv6 address / prefix of the UE 310 and the rules for routing to the UE 310 in the N4 session modification request message. The routing rules may include the network address of the application server 338c to which the application service is relocated.

[0109] 9. Based on the N4 session modification request message received from SMF 331, I-UPF 337 updates its forwarding rules for data traffic of UE 310 so that the data traffic of UE can be offloaded to PSA / UPF 338c. Then, I-UPF 337 may respond to SMF 331 to confirm receipt of the N4 session modification request message, such as Figure 7 As shown in 716.

[0110] After these steps in flow 700, I-UPF 337 may perform ULCL or BP to offload UE data traffic to PSA / UPF 338. PSA / UPF 338 may also transmit the offload traffic to application server 348 in local data network 340 via an N6 interface.

[0111] The above description and the accompanying drawings provide specific example embodiments and implementations. However, the subject matter described may be embodied in a variety of different forms, and therefore, the subject matter covered or claimed is intended to be interpreted as not being limited to any example embodiment set forth herein. It is intended to be a reasonably broad scope of the subject matter claimed or covered. Among them, for example, the subject matter may be embodied as a method, device, component, system or non-transitory computer-readable medium for storing computer code. Therefore, the embodiment may, for example, take the form of hardware, software, firmware, storage medium or any combination thereof. For example, the method embodiment described above may be implemented by a component, device or system including a memory and a processor by executing a computer code stored in the memory.

[0112] Throughout the specification and claims, in addition to the meanings explicitly stated, terms may have subtle meanings that are suggested or implied by the context. Likewise, the phrase "in one embodiment / implementation" as used herein does not necessarily refer to the same embodiment, and the phrase "in another embodiment / implementation" as used herein does not necessarily refer to a different embodiment. For example, it is intended that the claimed subject matter includes all or part combinations of the example embodiments.

[0113] In general, terms can be understood at least in part from the usage in the context. For example, terms such as "and", "or", "and / or" as used herein may include various meanings, which may depend at least in part on the context in which the terms are used. Typically, "or", if used to associate lists such as A, B, or C, is intended to mean A, B, and C, which are used here for inclusive meanings, and A, B, or C, which are used here for exclusive meanings. In addition, the term "one or more" as used herein, at least in part depending on the context, may be used to describe any feature, structure, or characteristic in a singular sense, or may be used to describe a combination of features, structures, or characteristics in a plural sense. Similarly, terms such as "a", "an," or "the," may be understood to convey singular usage or convey plural usage, at least in part depending on the context. In addition, the term "based on" may be understood to not necessarily be intended to convey an exclusive set of factors, but may allow the presence of additional factors that are not necessarily explicitly described, again at least in part depending on the context.

[0114] Throughout the specification, references to features, advantages, or similar language do not imply that all features and advantages that can be achieved with the present solution should be, or are included in, any single embodiment. Rather, language referring to features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present solution. Thus, throughout the specification, discussion of features and advantages and similar language may, but do not necessarily, refer to the same embodiment.

[0115] In addition, the described features, advantages, and characteristics of the present solution may be combined in any suitable manner in one or more embodiments. One of ordinary skill in the relevant art will recognize that, based on the description herein, the present solution may be practiced without one or more specific features or advantages of a particular embodiment. In other cases, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the present solution.

Claims

1. A method performed in a mobile core network including a communication session control node and an application service node, the method comprising: The communication session control node transmits a message for notifying the application service node of a relocation triggering event, wherein the relocation triggering event triggers the application service node to relocate an application service provided to the user equipment in a pre-established communication session from a previous application hosting server to a new application hosting server outside the mobile core network; as well as Relocation information is received by the communication session control node from the application service node, wherein the relocation information includes a network address of the new application hosting server.

2. The method according to claim 1, wherein: The mobile core network further includes an intermediate user plane node, and the method further includes: The network address of the new application hosting server is transmitted by the communication session control node to the intermediate user plane node.

3. The method according to claim 1, wherein: The relocation triggering event includes: The communication session anchor point identified in the subscription of the application service node has been established or released; or The data network access identifier used in the pre-established communication session has been changed.

4. The method according to claim 1, wherein: The message for notifying the relocation triggering event includes at least one of a list of one or more target data network access identifiers supported by the communication session control node and location information of the user equipment.

5. The method according to claim 1, wherein: The mobile core network further includes a plurality of anchor user plane nodes, the relocation information further includes a target data network access identifier and traffic routing information corresponding to the target data network access identifier, the target data network access identifier identifying one of the plurality of anchor user plane nodes associated with the new application hosting server.

6. The method of claim 5, further comprising establishing, by the communication session control node, a communication session between the user equipment and the anchor user plane node identified by the target data network access identifier.

7. The method according to claim 1, wherein: The relocation information also includes traffic filtering information, and the network address of the new application hosting server is included in the traffic filtering information.

8. The method according to claim 1, wherein: The network address of the new application hosting server is an Internet Protocol address or a Media Access Control address.

9. The method according to claim 1, wherein: The mobile core network further includes a network open node, and the transmitting a message for notifying a relocation triggering event includes transmitting a message for notifying a relocation triggering event to the application service node via the network open node.

10. The method according to claim 9, wherein: The receiving the relocation information includes receiving the relocation information from the application service node via the network open node.

11. A method performed in a mobile core network comprising a communication session control node and an application service node, the method comprising: The application service node receives a message for notifying a relocation triggering event from the communication session control node; In response to the relocation triggering event, the application service node relocates the application service provided to the user equipment in the pre-established communication session from the previous application hosting server to a new application hosting server outside the mobile core network; as well as The application service node transmits relocation information to the communication session control node, wherein the relocation information includes a network address of the new application hosting server.

12. The method according to claim 11, wherein: The message for notifying the relocation triggering event includes the location information of the user equipment, and relocating the application service includes relocating the application service to the new application hosting server based on the location information of the user equipment.

13. The method according to claim 11, wherein: The mobile core network includes multiple anchor user plane nodes, the message for notifying the relocation triggering event includes a list of one or more target data network access identifiers supported by the communication session control node, and the method also includes selecting, by the application service node, a target data network access identifier from the list of one or more target data network access identifiers, the target data network access identifier identifying one of the multiple anchor user plane nodes associated with the new application hosting server.

14. The method according to claim 13, wherein: The relocation information also includes the target data network access identifier and traffic routing information corresponding to the target data network access identifier.

15. The method according to claim 11, wherein: The relocation information also includes traffic filtering information, and the network address of the new application hosting server is included in the traffic filtering information.

16. The method according to claim 11, wherein: The mobile core network further includes a network open node, and the receiving a message for notifying a relocation triggering event includes receiving a message for notifying the relocation triggering event from the communication session control node via the network open node.

17. The method according to claim 16, wherein: Transmitting the relocation information includes transmitting the relocation information to the communication session control node via the network open node.

18. A method performed in a mobile core network comprising a communication session control node and an application service node, the method comprising: in response to an application service provided to a user equipment in a pre-established communication session being relocated by the application service node from a previous application hosting server to a new application hosting server outside the mobile core network, generating by the application service node a request for updating the application service relocation, wherein the request includes a network address of the new application hosting server; as well as The request is transmitted by the application service node to the communication session control node.

19. The method according to claim 18, wherein: The mobile core network further includes a plurality of anchor user plane nodes, the request further includes a target data network access identifier and traffic routing information corresponding to the target data network access identifier, the target data network access identifier identifying one of the plurality of anchor user plane nodes associated with the new application hosting server.

20. The method according to claim 18, wherein: The request also includes traffic filtering information, and the network address of the new application hosting server is included in the traffic filtering information.

21. The method according to claim 18, wherein: The mobile core network further includes a policy control node, and transmitting the request includes transmitting the request to the communication session control node via the policy control node.

22. The method according to claim 21, wherein: The mobile core network further includes a network open node, and transmitting the request includes transmitting the request to the communication session control node via the network open node and the policy control node.

23. The method according to claim 18, wherein: The network address of the new application hosting server is an Internet Protocol address or a Media Access Control address.

24. One or more core network nodes, the core network nodes comprising one or more processors and one or more memories, wherein the one or more processors are configured to read computer code from the one or more memories to implement the method according to any one of claims 1 to 23.

25. A computer program product comprising a non-transitory computer readable program medium having computer code stored thereon, which, when executed by one or more processors, causes the one or more processors to implement the method according to any one of claims 1 to 23.

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