A method and apparatus for application migration

Abstract

This application discloses an application migration method and apparatus, relating to the field of communication technology, which solves the problem in the prior art where the target AS is not accurately determined, resulting in large latency for the UE to access the application server. The specific solution is as follows: the source application function (AF) obtains first information, which is the UE's location information after the user plane path of the user equipment UE's Protocol Data Unit (PDU) session changes; based on the first information, the source AF determines the target application server (AS).

Description

[0001] This application claims priority to Chinese Patent Application No. PCT / CN2020 / 108751, filed on August 12, 2020, entitled "A Method and Apparatus for Application Migration", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communication technology, and in particular to a method and apparatus for application migration. Background Technology

[0003] In 5G mobile communication networks, to improve user experience and reduce latency when users access application servers (AS), operators or service providers can deploy application servers locally. When the terminal is in motion, there may be scenarios where user plane function (UPF) entities and ASs need to be switched.

[0004] Existing technologies propose an application migration method based on Session and Service Continuity (SSC) mode 3. SSC mode 3 is characterized by establishing a connection through the new PDU session anchor point before the connection between the user equipment (UE) and the previous protocol data unit (PDU) session anchor point is released, thus ensuring service continuity. In existing migration methods, during handover, when the UE's operating system (OS) detects the establishment of a new PDU session, the OS needs to notify the application client (AC). Upon receiving this notification, the AC triggers a Domain Name System (DNS) query to obtain the New AS address. The AC sends the New AS address to the Old AS, instructing the Old AS to perform application migration. After state synchronization between the Old AS and the New AS, the UE begins sending data packets to the New AS. However, when this method determines the New AS based on a DNS query, the DNS query results are not always accurate. The New AS determined based on this DNS query result may not be the most suitable application server. Therefore, migrating the AS accessed by the UE to the New AS can cause significant latency issues when the UE accesses the New AS. Summary of the Invention

[0005] This application provides a method and apparatus for application migration, which can more accurately determine the target AS and reduce the latency of UE accessing the application server.

[0006] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0007] A first aspect of this application provides an application migration method, comprising: a source application function (AF) acquiring first information, the first information being the location information of a user equipment (UE) after a change in the user plane path of its Protocol Data Unit (PDU) session; the source AF determining a target application server (AS) based on the first information; and the source AF sending connection information of the target AS to the UE. Based on this scheme, the target AS is determined by the source AF based on the UE's location information after a change in the user plane path of its PDU session. Therefore, the determined target AS is more accurate, and the latency when the UE accesses the target AS is lower, i.e., this scheme can reduce the latency of the UE accessing the application server. It is understood that this scheme is triggered by the network-side device (source AF) to reselect the target AS and migrate the application, without modifying the AC in the UE. Therefore, it does not require the AC to understand the network logic, simplifying the design of the AC. For example, the source AF in this scheme can be either a source AS or a source ES; that is, this application can determine the target AS by either the source AS or the source ES.

[0008] In conjunction with the first aspect, in one possible implementation, the target AS and the source AS serve the same application. The source AS can be the AS accessed by the UE before the user plane path of the UE's PDU session changes. Based on this scheme, the target AS determined by the source AF is an AS serving the same application as the source AS, thus ensuring the continuity of services accessed by the UE during UE movement. Optionally, a change in the user plane path of the UE's PDU session can be understood as a change in the UPF.

[0009] In conjunction with the first aspect and the aforementioned possible implementations, in another possible implementation, the location information of the UE is at least one of the following: the UE's IP address, the data network access identifier (DNAI) corresponding to the user plane path of the UE's PDU session, the UE's tracking area identifier (TAI), the UE's cell ID, the UE's radio access network identifier (RAN ID), or the UE's geographical location information. Based on this scheme, the source AF can determine the target AS based on the UE's IP address, DNAI, TAI, cell ID, RAN ID, or the UE's geographical location information, thus the determined target AS is more accurate. It is understood that in this application, the DNAI corresponding to the user plane path of the UE's PDU session is the DNAI corresponding to the data network that the UE can access.

[0010] In conjunction with the first aspect and the aforementioned possible implementations, in another possible implementation, the source AF determines the target AS based on the first information, including: the source AF obtaining information about the User Plane Function (UPF) entity after the user plane path of the UE's PDU session has changed based on the first information; and the source AF determining the target AS based on the information of the UPF entity. Based on this scheme, the source AF can determine the target AS based on the information of the user plane UPF, thus the determined target AS is more accurate, resulting in lower latency when the UE accesses the target AS. For example, the UPF information can be, for instance, DNAI or other information that can identify the UPF. Optionally, the source AF can obtain the UPF information by sending a query request to the 5GC.

[0011] Combining the first aspect and the aforementioned possible implementations, in another possible implementation, the source AF is the source AS. Based on this scheme, the source AS can determine the target AS and send the target AS's connection information to the UE, thereby reducing the latency for the UE to access the application server.

[0012] In conjunction with the first aspect and the above possible implementations, in another possible implementation, the source AF obtains the first information by: the source AS receiving a first notification message from a Policy Control Function (PCF) entity or a Session Management Function (SMF) entity. This first notification message is used to notify the source AS that the user plane path of the UE's PDU session has changed, and the first notification message includes the first information. Based on this scheme, the source AS can learn that the user plane path of the UE's PDU session has changed by receiving the first notification message sent by the PCF or SMF, and thus the source AS can determine the target AS based on the notification message. Optionally, the first notification message may not include the first information. When the first notification message does not include the first information, after receiving the first notification message, the source AS can request the first information from a core network element (e.g., the PCF or SMF) and then determine the target AS based on the first information.

[0013] In conjunction with the first aspect and the aforementioned possible implementations, in another possible implementation, the method further includes: the source AS subscribing to user plane management event notifications from the PCF entity or the SMF entity. These user plane management event notifications are used to notify the source AS when the user plane path of the UE's PDU session changes. Based on this scheme, by having the source AS subscribe to user plane management event notifications from the PCF or SMF, the source AS can be notified when the PCF or SMF determines that the user plane path of the UE's PDU session has changed.

[0014] In conjunction with the first aspect and the aforementioned possible implementations, in another possible implementation, the source AF obtains the first information by: the source AS receiving a second notification message from the source enable server ES. This second notification message notifies the source AS that the user plane path of the UE's PDU session has changed, and the second notification message includes the aforementioned first information. Based on this scheme, the source AS can learn that the user plane path of the UE's PDU session has changed by receiving the second notification message sent by the source ES. Therefore, the source AS can determine the target AS and decide to perform application migration based on this notification message.

[0015] In conjunction with the first aspect and the aforementioned possible implementations, in another possible implementation, the method further includes: the source AS subscribing to user plane management event notifications from the source ES. These user plane management event notifications are used to notify the source AS when the user plane path of the UE's PDU session changes. Based on this scheme, by having the source AS subscribe to user plane management event notifications from the source ES, the source AS can be notified when the source ES determines that the user plane path of the UE's PDU session has changed. Optionally, the source ES can learn of the change in the user plane path of the UE's PDU session by subscribing to user plane management event notifications from core network elements; the source ES can also learn of the change in the user plane path of the UE's PDU session by receiving notification messages sent by the UE.

[0016] In conjunction with the first aspect and the aforementioned possible implementations, in another possible implementation, the method further includes: the source AS sending connection information of the target AS to the UE. Based on this scheme, by sending connection information of the target AS to the UE through the source AS, the UE can establish a connection with the target AS, thereby reducing the latency for the UE to access the application server.

[0017] Combining the first aspect and the aforementioned possible implementations, in another possible implementation, the source AF is the source ES. Based on this scheme, the source ES can determine the target AS and send the connection information of the target AS to the UE, thereby reducing the latency for the UE to access the application server.

[0018] In conjunction with the first aspect and the aforementioned possible implementations, in another possible implementation, the source AF obtains the first information by: the source ES receiving a third notification message from a PCF entity or an SMF entity. This third notification message notifies the source ES that the user plane path of the UE's PDU session has changed, and the third notification message includes the aforementioned first information. Based on this scheme, the source ES can learn that the user plane path of the UE's PDU session has changed by receiving the third notification message sent by the PCF or SMF, thereby allowing the source ES to determine the target AS based on the notification message.

[0019] In conjunction with the first aspect and the aforementioned possible implementations, in another possible implementation, the method further includes: the source ES subscribing to user plane management event notifications from the PCF entity or the SMF entity. These user plane management event notifications are used to notify the source ES when the user plane path of the UE's PDU session changes. Based on this scheme, by having the source ES subscribe to user plane management event notifications from the PCF or SMF, the source ES can be notified when the PCF or SMF determines that the user plane path of the UE's PDU session has changed.

[0020] In conjunction with the first aspect and the aforementioned possible implementations, in another possible implementation, the source AF obtains the first information by: the source ES receiving a fourth notification message sent by the edge-enabled client (EEC) of the UE. This fourth notification message is used to notify the source ES of the UE's PDU session reconstruction, and includes the aforementioned first information. Based on this scheme, the source ES can learn about the UE's PDU session reconstruction by receiving the fourth notification message sent by the UE's EEC. Therefore, the source ES can determine the target AS based on this notification message, resulting in a more accurate target AS and reducing the latency for the UE to access the application server.

[0021] In conjunction with the first aspect and the aforementioned possible implementations, another possible implementation further includes: the source ES sending connection information of the target AS to the UE. Based on this scheme, by sending connection information of the target AS to the UE through the source ES, the UE can establish a connection with the target AS, thereby reducing the latency for the UE to access the application server.

[0022] In conjunction with the first aspect and the aforementioned possible implementations, in another possible implementation, the source AF is a configuration server (CS), and the method further includes: the CS receiving first indication information from the UE, the first indication information instructing the CS to send target data network (DN) information to the UE when the user plane path of the UE's PDU session changes; the CS determining the target DN based on the first information; and the CS sending the target DN information to the UE. Based on this scheme, the CS determines the target DN based on the UE's location information after the user plane path of the UE's PDU session changes, thus the determined target AF is more accurate. Therefore, after the UE accesses the target DN, the latency of the UE accessing the data network can be reduced. For example, when the UE moves, the SMF decides to rebuild the PDU session. The CS can determine the target DN based on the UE's location information after the PDU session is rebuilt and send the target DN information to the UE, thereby allowing the UE to access the target DN.

[0023] In conjunction with the first aspect and the aforementioned possible implementations, in another possible implementation, the CS obtaining the first information includes: the CS receiving second indication information from the UE, the second indication information being used to indicate that the UE's PDU session has been rebuilt, and the second indication information including the aforementioned first information. Based on this scheme, the CS can know that the UE's PDU session has been rebuilt by receiving the UE's indication information, and thus the CS can determine the target DN based on the indication information. Therefore, the determined target AS is more accurate, and the latency of the UE accessing the data network can be reduced after the UE accesses the target DN.

[0024] In conjunction with the first aspect and the aforementioned possible implementations, in another possible implementation, the CS obtaining the first information includes: the CS receiving a fifth notification message from a Policy Control Function (PCF) entity or a Session Management Function (SMF) entity. This fifth notification message notifies the CS that the user plane path of the UE's PDU session has changed, and the fifth notification message includes the aforementioned first information. Based on this scheme, the CS can learn that the UE's PDU session has been rebuilt by receiving the notification message from the PCF or SMF. Therefore, the CS can determine the target DN based on this notification message, resulting in a more accurate determined target AS.

[0025] In conjunction with the first aspect and the aforementioned possible implementations, in another possible implementation, the method further includes: the CS subscribing to user plane management event notifications from the PCF entity or the SMF entity. These user plane management event notifications are used to notify the CS when the user plane path of the UE's PDU session changes. Based on this scheme, by having the CS subscribe to user plane management event notifications from the PCF or SMF, the CS can be notified when the PCF or SMF determines that the user plane path of the UE's PDU session has changed.

[0026] Combining the first aspect and the aforementioned possible implementations, in another possible implementation, the change in the user plane path of the UE's PDU session includes a change in the UE's PDU session anchor point, and the session and service continuity (SSC) mode of the UE's PDU session is mode 3. Based on this scheme, the source AF can determine the target AS when the UE's PDU session anchor point changes. Optionally, if the UE's PDU session anchor point does not change, the data network accessed by the UE may not change, and therefore application migration may not be necessary. Thus, the change in the user plane path of the UE's PDU session in this application can be understood as a change in the UE's PDU session anchor point.

[0027] A second aspect of this application provides an application migration method, comprising: a source enabling server (ES) acquiring first information, the first information being the location information of a user equipment (UE) after a change in the user plane path of its Protocol Data Unit (PDU) session; the source ES sending a second notification message to a source application server (AS); the second notification message notifying the source AS of the change in the user plane path of the UE's PDU session, the source AS being the AS accessed by the UE before the change in the user plane path of the UE's PDU session. Based on this scheme, by notifying the source AS of the change in the user plane path of the UE's PDU session through the source ES, the source AS can determine the target AS. It is understood that the source AS can determine the target AS based on the first information, therefore the determined target AS is more accurate, and the latency when the UE accesses the target AS is lower, i.e., this scheme can reduce the latency of the UE accessing the application server. It is also understood that this scheme can trigger the reselection of the target AS and application migration by the source AS without modifying the AC in the UE; therefore, it does not require the AC to understand network logic, simplifying the design of the AC.

[0028] In conjunction with the second aspect, in one possible implementation, the location information of the UE is at least one of the following: the UE's network protocol IP address, the data network access identifier (DNAI) corresponding to the user plane path of the UE's PDU session, the UE's tracking area identifier (TAI), the UE's cell ID, the UE's radio access network identifier (RAN ID), or the UE's geographical location information. Based on this scheme, the source ES can determine the target AS based on the UE's IP address, DNAI, TAI, cell ID, RAN ID, or the UE's geographical location information, thus the determined target AS is relatively accurate.

[0029] In conjunction with the second aspect and the above possible implementations, in another possible implementation, the method further includes: the source ES receiving a user plane management event notification subscribed to by the source AS, the user plane management event notification being used to notify the source AS when the user plane path of the UE's PDU session changes. Based on this scheme, by having the source AS subscribe to user plane management event notifications from the source ES, the source AS can be notified when the source ES determines that the user plane path of the UE's PDU session has changed.

[0030] In conjunction with the second aspect and the aforementioned possible implementations, in another possible implementation, the source ES obtaining the first information includes: the source ES receiving a fourth notification message sent by the edge-enabled client (EEC) of the UE, the fourth notification message being used to notify the source ES of the UE's PDU session reconstruction, and the fourth notification message including the aforementioned first information. Based on this scheme, the source ES can learn of the UE's PDU session reconstruction by receiving the fourth notification message sent by the UE's EEC, thereby the source ES can notify the source AS that the user plane path of the UE's PDU session has changed.

[0031] Combining the second aspect and the aforementioned possible implementations, in another possible implementation, the change in the user plane path of the UE's PDU session includes a change in the UE's PDU session anchor point, and the session and service continuity (SSC) mode of the UE's PDU session is mode 3. Based on this scheme, since the UE's PDU session SSC mode is mode 3, after the UE's PDU session anchor point changes, the source ES can notify the source AS, thereby enabling the source AS to determine the target AS and trigger application migration. The determined target is more accurate, reducing the latency of the UE accessing the application server. Moreover, this scheme allows the source AS to trigger the reselection of the target AS and application migration without modifying the AC in the UE. Therefore, it does not require the AC to understand the network logic, simplifying the design of the AC.

[0032] A third aspect of this application provides an application migration method, comprising: an edge-enabled client (EEC) of a user equipment (UE) subscribing to a session reconstruction event notification from the UE's operating system (OS), the session reconstruction event notification being used to notify the EEC when the UE's Protocol Data Unit (PDU) session is reconstructed; the EEC receiving a sixth notification message from the OS, the sixth notification message being used to notify the EEC of the UE's PDU session reconstruction, the sixth notification message including first information, the first information being the UE's location information after the PDU session reconstruction. Based on this scheme, by having the EEC in the UE subscribe to the session reconstruction event notification from the OS in the UE, the OS in the UE can notify the EEC in the UE when the UE's PDU session is reconstructed, allowing the EEC to obtain relevant user plane information. Optionally, the EEC in the UE can determine the target AS based on the first information (UE's location information), thus the determined target AS is more accurate, and the latency when the UE accesses the target AS is lower, i.e., this scheme can reduce the latency of the UE accessing the application server. Moreover, this method does not require the AC in the UE to understand network logic, which simplifies the design of the AC.

[0033] In conjunction with the third aspect, in one possible implementation, the location information of the UE is at least one of the following: the UE's IP address, the Data Network Access Identifier (DNAI) corresponding to the user plane path of the UE's PDU session, the UE's Tracking Area Identifier (TAI), the UE's Cell ID, the UE's Radio Access Network Identifier (RAN ID), or the UE's geographical location information. Based on this scheme, the EEC can determine the target AS based on the UE's IP address, DNAI, TAI, cell ID, RAN ID, or the UE's geographical location information, thus the determined target AS is relatively accurate.

[0034] In conjunction with the third aspect and the above possible implementations, in another possible implementation, the method further includes: the EEC sending a fourth notification message to the source enabling server ES. This fourth notification message is used to notify the source ES of the PDU session reconstruction of the UE, and includes the first information mentioned above. Based on this scheme, by notifying the source ES of the UE's PDU session reconstruction through the EEC in the UE, the source ES can determine the target AS and perform application migration based on the notification message sent by the EEC. The target AS determined by this method is more accurate, thus reducing the latency for the UE to access the target AS. Moreover, this method does not require the AC in the UE to understand the network logic, which simplifies the design of the AC.

[0035] In conjunction with the third aspect and the above possible implementations, in another possible implementation, the method further includes: the EEC determining the target application server AS based on the first information; the target AS serving the same application as the source AS, which is the AS accessed by the UE before the PDU session reconstruction. Based on this scheme, when the EEC in the UE learns that the user plane path of the UE's PDU session has changed, it can determine the target AS itself. This not only ensures a more accurate determination of the target AS but also eliminates the need for the AC in the UE to understand the network logic, thus simplifying AC design.

[0036] In conjunction with the third aspect and the aforementioned possible implementations, in another possible implementation, the EEC determines the target application server AS based on the first information, including: the EEC determining the target ES based on the first information; the EEC sending a discovery request to the target ES; the EEC receiving a first message from the target ES, the first message including connection information of one or more ASs managed by the target ES, wherein the one or more ASs managed by the target ES serve the same application as the source AS; and the EEC determining the target AS from the one or more ASs managed by the target ES. Based on this scheme, the EEC in the UE can determine the target AS from the one or more ASs managed by the target ES, thereby enabling access to the target AS. Therefore, the determined target AS is more accurate, and the latency for the UE to access the target AS is lower. Moreover, this scheme does not require modification to the AC in the UE, simplifying the AC design.

[0037] In conjunction with the third aspect and the aforementioned possible implementations, in another possible implementation, the method further includes: the EEC sending connection information of the target AS to the source AS or source ES, so that the source AS or source ES migrates the UE's context from the source AS to the target AS. Based on this scheme, the source AS or source ES can migrate the UE's context from the source AS to the target AS, thereby eliminating the need to strengthen the AC logic in the UE and simplifying the AC design.

[0038] Combining the third aspect and the aforementioned possible implementations, in another possible implementation, the user plane path change of the UE's PDU session includes the reconstruction of the UE's PDU session. Based on this scheme, the OS in the UE can notify the EEC in the UE when the UE's PDU session is reconstructed. This method does not require the AC in the UE to understand the network logic, thus simplifying the design of the AC.

[0039] Combining the third aspect and the aforementioned possible implementations, in another possible implementation, the user plane path change of the UE's PDU session includes a change in the UE's PDU session anchor point, and the session and service continuity (SSC) mode of the UE's PDU session is mode 3. Based on this scheme, since the SSC mode of the UE's PDU session is mode 3, it is possible to determine the target AS and perform application migration after the UE's PDU session anchor point changes, thereby reducing the latency of the UE accessing the application server.

[0040] A fourth aspect of this application provides an application migration method, comprising: a source application server (AS) sending a subscription request to a source enable server (ES), the subscription request being used to notify the source AS when the source ES determines that a target AS exists; the source AS receiving a seventh notification message from the source ES, the seventh notification message including connection information of the target AS; and the source AS determining to migrate the context of a user equipment (UE) from the source AS to the target AS. For example, the target AS and the source AS serve the same application. Based on this scheme, by sending a subscription request from the source AS to the source ES, a notification message including the connection information of the target AS can be sent to the source AS when the source ES determines that a target AS exists in the data network accessible to the UE, and then the application migration is triggered by the source AS. Since the user plane path of the UE's PDU session changes, the data network accessible to the UE may not necessarily have an AS serving the same application as the source AS deployed. Therefore, by sending a subscription request, the source ES can notify the source AS when it determines that an AS serving the same application exists in the data network accessible to the UE, thereby initiating the application migration. This reduces invalid notifications during the application migration process and lowers latency.

[0041] In conjunction with the fourth aspect, in one possible implementation, the above method further includes: the source AS sending a fourth indication message to the source ES, which instructs the source ES to migrate the UE's context from the source AS to the target AS. Based on this scheme, by sending the indication message from the source AS to the source ES instructing the source ES to migrate the UE's context from the source AS to the target AS, the source ES can migrate the UE's context from the source AS to the target AS, thereby reducing the latency of the UE accessing the application server.

[0042] In conjunction with the fourth aspect, in one possible implementation, the method further includes: the source AS sending an application handover request message to the target AS, the application handover request message being used to migrate the context on the source AS to the target AS. Based on this scheme, by sending an application handover request message from the source AS to the target AS, the target AS can migrate the context on the source AS to the target AS, thereby reducing the latency for the UE to access the application server.

[0043] In conjunction with the fourth aspect, in one possible implementation, the method further includes: the source AS receiving an application handover response message from the target AS, the application handover response message including third indication information, the third indication information being used to indicate whether the target AS agrees to the application handover; correspondingly, the source AS determining to migrate the UE's context from the source AS to the target AS includes: if the third indication information indicates that the target AS agrees to the application handover, the source AS determining to migrate the UE's context from the source AS to the target AS. Based on this scheme, the target AS can send an application handover response message to the source AS, thereby determining to trigger the application migration only after the target AS agrees to the application handover, thus avoiding migration failure.

[0044] In conjunction with the fourth aspect and the above possible implementations, in another possible implementation, the method further includes: the source AS sending a fifth indication message to the source ES, the fifth indication message indicating whether the source AS supports application handover. Based on this scheme, the source ES can determine whether the source AS supports application handover. If the source ES determines that the source AS supports application handover, then after the source ES determines that a target AS exists in the data network accessible to the UE, the source ES can perform application migration.

[0045] In conjunction with the fourth aspect and the above possible implementations, another possible implementation includes the method further comprising: the source AS sending a seventh indication message to the source ES, which indicates that service continuity needs to be maintained during application handover. Based on this scheme, by sending the seventh indication message from the source AS to the source ES, a forwarding tunnel between UPFs can be established when the DNAI changes for service continuity purposes, so that the UE can send application data to the source AS.

[0046] A fifth aspect of this application provides an application migration method, comprising: a source enable server (ES) receiving a subscription request from a source application server (AS), the subscription request being used to notify the source AS when the source ES determines that a target AS exists; the source ES obtaining first information, the first information being the location information of the UE after the user plane path of the UE's Protocol Data Unit (PDU) session has changed; and the source ES determining the target AS based on the first information. For example, the target AS and the source AS serve the same application. Based on this scheme, by sending a subscription request from the source AS to the source ES, when the source ES determines that a target AS exists in the DN accessible to the UE, the source ES sends a notification message including connection information of the target AS to the source AS. Since after the user plane path of the UE's PDU session changes, the data network accessible to the UE may not necessarily have an AS serving the same application as the source AS deployed. Therefore, by sending a subscription request, the source ES can notify the source AS only when it determines that an AS serving the same application exists in the data network accessible to the UE, thereby initiating application migration. This reduces invalid notifications during the application migration process and lowers latency.

[0047] In conjunction with the fifth aspect, in one possible implementation, the source ES sends a seventh notification message to the source AS, which includes the connection information of the target AS. Based on this scheme, by having the source AS send a subscription request to the source ES, the source ES can send a notification message including the connection information of the target AS to the source AS when it determines that a target AS exists in the DN accessible to the UE. It is understandable that when the source ES determines that a target AS exists, the source ES sends a seventh notification message to the source AS.

[0048] In conjunction with the fifth aspect and the aforementioned possible implementations, in another possible implementation, the location information of the UE is at least one of the following: the UE's IP address, the Data Network Access Identifier (DNAI) corresponding to the user plane path of the UE's PDU session, the UE's Tracking Area Identifier (TAI), the UE's Cell Identifier (cell ID), the UE's Radio Access Network Identifier (RAN ID), or the UE's geographical location information. Based on this scheme, the source ES can determine the existence of a target AS in the DNs accessible to the UE based on the UE's IP address, DNAI, TAI, cell ID, RAN ID, or the UE's geographical location information, thus the determination result is relatively accurate.

[0049] In conjunction with the fifth aspect and the above possible implementations, in another possible implementation, the source ES obtains the first information by receiving a third notification message from a Policy Control Function (PCF) entity or a Session Management Function (SMF) entity. This third notification message notifies the source ES that the user plane path of the UE's PDU session has changed, and the third notification message includes the aforementioned first information. Based on this scheme, by receiving the third notification message sent by the PCF or SMF, the source ES can learn that the user plane path of the UE's PDU session has changed, and thus the source ES can determine, based on the notification message, that a target AS exists in the DNs accessible to the UE.

[0050] In conjunction with the fifth aspect and the possible implementations described above, in another possible implementation, the method further includes: the source ES subscribing to user plane management event notifications from the PCF entity or the SMF entity. These user plane management event notifications are used to notify the source ES when the user plane path of the UE's PDU session changes. Based on this scheme, by having the source ES subscribe to user plane management event notifications from the PCF or SMF, the source ES can be notified when the PCF or SMF determines that the user plane path of the UE's PDU session has changed.

[0051] In conjunction with the fifth aspect and the aforementioned possible implementations, in another possible implementation, the subscription request includes information about the UE's PDU session. This PDU session information includes at least one of the UE's network protocol IP address, data network name (DNN), or single network slice selection auxiliary information (S-NSSAI). Based on this scheme, by carrying the UE's PDU session information in the subscription request, the source ES can identify the 5GC network element accessed by the UE based on this PDU session information.

[0052] In conjunction with the fifth aspect and the above possible implementations, in another possible implementation, the method further includes: the source ES determining the Policy Control Function (PCF) entity or the Session Management Function (SMF) entity based on the UE's PDU session information. Based on this scheme, the source ES can determine the PCF entity or SMF entity accessed by the UE based on the UE's PDU session information.

[0053] In conjunction with the fifth aspect and the above possible implementations, in another possible implementation, the subscription request includes the application identification information, and the source ES determines the target AS based on the first information, including: the source ES determining the target AS based on the first information and the application identification information. Based on this scheme, the source ES can determine the target AS based on the first information and the application identification information; therefore, the determined target AS is more accurate, which can reduce the latency for the UE to access the application server.

[0054] In conjunction with the fifth aspect and the above possible implementations, in another possible implementation, the method further includes: the source ES sending a sixth indication message to the SMF, which indicates whether the source AS supports application handover. Based on this scheme, by sending the indication message from the source ES to the 5GC to indicate whether the source AS supports application handover, the 5GC can terminate the user plane path of the PDU session of the UE in scenarios where the source AS does not support application handover.

[0055] In conjunction with the fifth aspect and the above possible implementations, in another possible implementation, the method further includes: the source ES receiving a seventh indication information from the source AS, which indicates that service continuity needs to be maintained during application handover. Based on this scheme, a forwarding tunnel between UPFs can be established when the DNAI changes for service continuity, so that the UE can send application data to the source AS.

[0056] In conjunction with the fifth aspect and the above possible implementations, another possible implementation further includes: the source ES sending an eighth indication message to the SMF or PCF, which indicates that service continuity needs to be maintained during application handover. Based on this scheme, by sending the eighth indication message from the source ES to the SMF or PCF, the 5GC network element can release the forwarding tunnel after the application handover is completed.

[0057] In conjunction with the fifth aspect and the above possible implementations, in another possible implementation, the method further includes: the source ES sending the connection information of the target AS to the SMF or PCF. Based on this scheme, by sending the connection information of the target AS to the SMF or PCF through the source ES, the SMF or PCF can send the connection information of the target AS to the UE, thereby enabling the UE to establish a connection with the target AS and reducing the latency of the UE accessing the application server.

[0058] A sixth aspect of this application provides an application migration method, comprising: a configuration server (CS) receiving first indication information from a user equipment (UE), the first indication information instructing the CS to send target data network (DN) information to the UE when the user plane path of the UE's Protocol Data Unit (PDU) session changes; the CS acquiring first information, the first information being the UE's location information after the user plane path of the UE's PDU session changes; the CS determining the target DN based on the first information; and the CS sending the target DN information to the UE. Based on this scheme, the CS determines the target DN based on the UE's location information after the user plane path of the UE's PDU session changes, thus the determined target DN is more accurate, and therefore the latency of the UE accessing the data network can be reduced after the UE accesses the target DN. Optionally, the SSC mode of the UE's PDU session can be mode 3. When the SSC mode of the UE's PDU session can be mode 3, the aforementioned change in the user plane path of the UE's PDU session includes the reconstruction of the UE's PDU session.

[0059] In conjunction with the sixth aspect, in one possible implementation, the location information of the UE is at least one of the following: the UE's IP address, the Data Network Access Identifier (DNAI) corresponding to the user plane path of the UE's PDU session, the UE's Tracking Area Identifier (TAI), the UE's Cell Identifier (cell ID), the UE's Radio Access Network Identifier (RAN ID), or the UE's geographical location information. Based on this scheme, the CS can determine the target DN based on the UE's IP address, DNAI, TAI, cell ID, RAN ID, or the UE's geographical location information, thus the determination result is relatively accurate.

[0060] In conjunction with the sixth aspect and the above possible implementations, in another possible implementation, the CS obtaining the first information includes: the CS receiving second indication information from the UE, the second indication information being used to indicate that the UE's PDU session has been rebuilt, and the second indication information including the first information. Based on this scheme, the CS can know that the UE's PDU session has been rebuilt by receiving the UE's indication information, and thus the CS can determine the target DN based on the indication information. Therefore, the determined target AS is more accurate, and the latency of the UE accessing the data network can be reduced after the UE accesses the target DN.

[0061] In conjunction with the sixth aspect and the above possible implementations, in another possible implementation, the CS obtaining the first information includes: the CS receiving a fifth notification message from the Policy Control Function (PCF) entity or the Session Management Function (SMF) entity. This fifth notification message notifies the CS that the user plane path of the UE's PDU session has changed, and the fifth notification message includes the aforementioned first information. Based on this scheme, the CS can learn that the UE's PDU session has been rebuilt by receiving the notification message from the PCF or SMF. Therefore, the CS can determine the target DN based on this notification message, resulting in a more accurate determined target AS.

[0062] In conjunction with the sixth aspect and the above possible implementations, in another possible implementation, the method further includes: the CS subscribing to user plane management event notifications from the PCF entity or the SMF entity. These user plane management event notifications are used to notify the CS when the user plane path of the UE's PDU session changes. Based on this scheme, by having the CS subscribe to user plane management event notifications from the PCF or SMF, the CS can be notified when the PCF or SMF determines that the user plane path of the UE's PDU session has changed.

[0063] In conjunction with the sixth aspect and the above possible implementations, in another possible implementation, the user plane path change of the UE's PDU session includes the reconstruction of the UE's PDU session. Based on this scheme, the CS can determine the target DN when the UE's PDU session is reconstructed. Optionally, if the UE's PDU session is not reconstructed, the data network accessed by the UE may not change, and therefore application migration may not be required. Thus, the user plane path change of the UE's PDU session in this application can be considered as the reconstruction of the UE's PDU session.

[0064] In conjunction with the sixth aspect and the aforementioned possible implementations, in another possible implementation, the user plane path change of the UE's PDU session includes a change in the UE's PDU session anchor point, and the session and service continuity (SSC) mode of the UE's PDU session is mode 3. Based on this scheme, since the SSC mode of the UE's PDU session is mode 3, the target DN can be determined after the UE's PDU session is rebuilt.

[0065] A seventh aspect of this application provides an application migration method, comprising: a configuration server (CS) acquiring first information, wherein the first information is the location information of a user equipment (UE) after a change in the user plane path of a Protocol Data Unit (PDU) session; and the CS determining a target enabling server (ES) based on the first information. Based on this scheme, the CS determines the target ES based on the UE's location information after the change in the user plane path of the UE's PDU session, thus the determined target ES is more accurate, making the target AS determined based on the target ES more accurate, and reducing the latency when the UE accesses the target AS. In other words, this scheme can reduce the latency of the UE accessing the application server.

[0066] In conjunction with the seventh aspect, in one possible implementation, the aforementioned UE location information includes at least one of the following: the UE's network protocol IP address, the data network access identifier (DNAI) corresponding to the user plane path of the UE's PDU session, the UE's tracking area identifier (TAI), the UE's cell identifier, the UE's radio access network identifier, or the UE's geographic location information. Based on this scheme, the CS can determine the target ES based on the UE's IP address, DNAI, TAI, cell ID, RAN ID, or the UE's geographic location information, thus the determined target ES is relatively accurate.

[0067] In conjunction with the seventh aspect and the above possible implementations, in another possible implementation, the CS obtains the first information by receiving first information from the UE. Based on this scheme, the CS can receive the UE's location information after the user plane path of the UE's PDU session has changed, thereby making the target ES determined by the CS based on the UE's location information more accurate and reducing the latency of the UE accessing the application server.

[0068] In conjunction with the seventh aspect and the above possible implementations, in another possible implementation, the method further includes: the CS sending the connection information of the target ES to the UE. Based on this scheme, by having the CS send the connection information of the target ES to the UE, the UE can request the target AS based on the connection information of the target ES, thereby reducing the latency of the UE accessing the application server.

[0069] In conjunction with the seventh aspect and the above possible implementations, in another possible implementation, the CS obtains the first information by receiving first information from the source ES. Based on this scheme, the CS can receive the UE's location information after the user plane path of the UE's PDU session has changed from the source ES, thereby making the target ES determined by the CS based on the UE's location information more accurate and reducing the latency of the UE accessing the application server.

[0070] In conjunction with the seventh aspect and the above possible implementations, in another possible implementation, the method further includes: the CS sending the connection information of the target ES to the source ES. Based on this scheme, by having the CS send the connection information of the target ES to the source ES, the UE can request the target AS based on the connection information of the target ES, thereby reducing the latency of the UE accessing the application server.

[0071] In conjunction with the seventh aspect and the aforementioned possible implementations, in another possible implementation, the first information is the UE's IP address after the user plane path of the UE's PDU session has changed. The CS determines the target ES based on this first information, including: the CS determining the DNAI of the UE's PDU session after the user plane path change based on the UE's IP address; and the CS determining the target ES based on this DNAI. Based on this scheme, the CS can determine the DNAI based on the UE's IP address, and thus can determine the target ES based on the DNAI, resulting in a more accurate determination of the target ES.

[0072] Combining the seventh aspect and the aforementioned possible implementations, in another possible implementation, the user plane path change of the UE's PDU session includes a change in the UE's PDU session anchor point, and the UE's session and service continuity SSC mode is mode 3. Based on this scheme, the UE's PDU session SSC mode is mode 3, and the user plane path change of the UE's PDU session includes a change in the UE's PDU session anchor point. In other words, this scheme determines the target ES based on the UE's location information after the session anchor point change when the UE's PDU session anchor point changes; therefore, the determined target ES is more accurate.

[0073] An eighth aspect of this application provides an application migration method, comprising: a source enabling server (ES) acquiring first information, the first information being the location information of a user equipment (UE) after a change in the user plane path of its Protocol Data Unit (PDU) session; the source ES sending the first information to a configuration server (CS); and the source ES receiving connection information from a target ES from the CS. Based on this scheme, by sending the first information from the source ES to the CS, the CS can determine the target ES based on the first information, thus the determined target ES is more accurate and can reduce the latency of the UE accessing the application server.

[0074] In conjunction with aspect eight, in one possible implementation, the aforementioned UE location information includes at least one of the following: the UE's network protocol IP address, the data network access identifier (DNAI) corresponding to the user plane path of the UE's PDU session, the UE's tracking area identifier (TAI), the UE's cell identifier, the UE's radio access network identifier, or the UE's geographic location information. Based on this scheme, the CS can determine the target ES based on the UE's IP address, DNAI, TAI, cell ID, RAN ID, or the UE's geographic location information, thus the determined target ES is relatively accurate.

[0075] In conjunction with the eighth aspect and the above possible implementations, in another possible implementation, the source ES obtains the first information by receiving first information from the UE. Based on this scheme, the source ES receives the first information from the UE and sends the first information to the CS, thereby enabling the CS to determine the target ES more accurately based on the first information.

[0076] In conjunction with the eighth aspect and the above possible implementations, in another possible implementation, the source ES obtains the aforementioned first information by: the source ES receiving a third notification message from a Policy Control Function (PCF) entity or a Session Management Function (SMF) entity. This third notification message is used to notify the source ES that the user plane path of the UE's PDU session has changed, and the third notification message includes the aforementioned first information. Based on this scheme, the source ES can also obtain the first information from the 5GC network element and send it to the CS, thereby enabling the CS to more accurately determine the target ES based on the first information.

[0077] In conjunction with the eighth aspect and the aforementioned possible implementations, in another possible implementation, the source ES subscribes to user plane management event notifications from the aforementioned PCF entity or the aforementioned SMF entity. These user plane management event notifications are used to notify the source ES when the user plane path of the aforementioned UE's PDU session changes. Based on this scheme, the source ES can subscribe to user plane management event notifications from the 5GC network element, thereby becoming aware of changes in the user plane path of the UE's PDU session and obtaining the UE's location information after the user plane path change.

[0078] In conjunction with the eighth aspect and the above possible implementations, in another possible implementation, the method further includes: the source ES sending a first application discovery request to the target ES, the first application discovery request being used to request the acquisition of the target AS; and the source ES receiving connection information of the target AS from the target ES. Based on this scheme, the source ES can send a first application discovery request to the target ES to obtain information about the target AS from the target ES.

[0079] In conjunction with the eighth aspect and the aforementioned possible implementations, in another possible implementation, the target AS serves the same application as the source AS, which is the AS accessed by the UE before the user plane path of the UE's PDU session changes. Based on this scheme, the target AS determined by the target ES is an AS serving the same application as the source AS, thus ensuring the continuity of services accessed by the UE during UE movement.

[0080] In conjunction with the eighth aspect and the above possible implementations, in another possible implementation, the method further includes: the source ES sending connection information of the target AS to the UE. Based on this scheme, by sending connection information of the target AS to the UE through the source ES, the UE can establish a connection with the target AS, thereby enabling the UE's context to switch from the source AS to the target AS, reducing the latency of the UE accessing the application server.

[0081] A ninth aspect of this application provides an application migration method, comprising: a user equipment (UE) receiving first information from a session management function (SMF) entity or a user plane function (UPF) entity, the first information being the location information of the UE after a change in the user plane path of its protocol data unit (PDU) session; and the UE sending the first information to an application function (AF). The AF can be a service center (CS) or a source application server (ES). Based on this scheme, by having the UE send the location information of the UE after a change in the user plane path of its PDU session to the CS or the source ES, the CS can determine a target ES based on the UE's location information. Therefore, the determined target ES is more accurate, and consequently, the target application server (AS) determined based on the target ES is more accurate, resulting in lower latency when the UE accesses the target AS. In other words, this scheme can reduce the latency of the UE accessing the application server.

[0082] In conjunction with aspect nine, in one possible implementation, the UE's location information includes at least one of the following: the UE's network protocol IP address, the data network access identifier (DNAI) corresponding to the user plane path of the UE's PDU session, the UE's tracking area identifier (TAI), the UE's cell identifier, the UE's radio access network identifier, or the UE's geographic location information. Based on this scheme, the UE can send its IP address, DNAI, TAI, cell ID, RAN ID, or geographic location information to the AF, enabling the CS to determine the target ES based on the above information, thus resulting in a more accurate determined target ES.

[0083] In conjunction with the ninth aspect and the above possible implementations, in another possible implementation, the AF is a configuration server (CS), and the method further includes: the UE receiving connection information from the target enable server (ES) from the CS. Based on this scheme, the CS can determine the target ES based on the UE's location information after the user plane path of the PDU session changes, and send the target ES to the UE, thereby enabling the UE to request the target AS from the target ES and establish a connection with the target AS, reducing the latency for the UE to access the application server.

[0084] In conjunction with aspect nine and the aforementioned possible implementations, in another possible implementation, the method further includes: the UE sending a second application discovery request to the target ES, the second application discovery request being used to request the acquisition of a target AS; and the UE receiving connection information of the target AS from the target ES. Based on this scheme, the UE can request the acquisition of a target AS from the target ES, thereby enabling the UE to establish a connection with the target AS and reducing the latency of the UE accessing the application server.

[0085] Combining the ninth aspect and the above possible implementations, in another possible implementation, the aforementioned AF is the source ES. Based on this scheme, by having the UE send the UE's location information after the user plane path of the UE's PDU session changes to the source ES, the source ES can send this location information to the CS. The CS can then determine the target ES based on the UE's location information. Therefore, the determined target ES is more accurate, and consequently, the determined target AS based on the target ES is more accurate. The latency when the UE accesses the target AS is lower, meaning this scheme can reduce the latency when the UE accesses the application server.

[0086] In conjunction with aspect nine and the aforementioned possible implementations, in another possible implementation, the method further includes: the UE receiving connection information from the target AS of the source ES. Based on this scheme, the UE can obtain the connection information of the target AS from the source ES, thereby enabling the UE to establish a connection with the target AS and reducing the latency of the UE accessing the application server.

[0087] A tenth aspect of this application provides an application migration method, comprising: a source application server (AS) subscribing to an available AS notification from a source enable server (ES), the available AS notification being used to notify the source AS when the source ES determines that a target AS exists in a data network (DN) accessible to a user equipment (UE); the source AS receiving a seventh notification message from the source ES, the seventh notification message including the address information of the target AS; and the source AS determining to migrate the AS accessed by the UE from the source AS to the target AS. For example, the target AS and the source AS serve the same application. Based on this scheme, by having the source AS subscribe to the available AS notification from the source ES, a notification message including the address information of the target AS can be sent to the source AS only when the source ES determines that a target AS exists in a data network (DN) accessible to the UE, and then the application migration is triggered by the source AS. Since the user plane path of the UE's PDU session may change, the data network that the UE can access may not have an AS with the same application as the source AS. Therefore, by subscribing to the notification of the available AS, the source ES can notify the source AS when it determines that there is an AS with the same application as the source AS in the data network that the UE can access, and then initiate the application migration. This can reduce invalid notifications during the application migration process and reduce latency.

[0088] In conjunction with the tenth aspect, in one possible implementation, the method further includes: the source AS sending an application switching request message to the target AS; the source AS receiving an application switching response message from the target AS, the application switching response message including third indication information, the third indication information being used to indicate whether the target AS agrees to the application switching. Based on this scheme, the source AS can avoid migration failure by sending an application switching request message to the target AS and then determining to trigger application migration only if the target AS agrees to the application switching.

[0089] In conjunction with the tenth aspect and the above possible implementations, in another possible implementation, the source AS determines to migrate the AS accessed by the UE from the source AS to the target AS, including: if the third indication information indicates that the target AS agrees to the application handover, the source AS determines to migrate the AS accessed by the UE from the source AS to the target AS. Based on this scheme, the source AS can determine to trigger the application migration only after the target AS agrees to the application handover, thereby avoiding migration failure.

[0090] The eleventh aspect of this application provides an application migration method, comprising: a source enable server (ES) receiving an available AS notification subscribed to by a source application server (AS), the available AS notification being used to notify the source AS when the source ES determines that a target AS exists in a data network (DN) accessible to a user equipment (UE); the source ES obtaining first information, the first information being the location information of the UE after the user plane path of the UE's Protocol Data Unit (PDU) session has changed; the source ES determining, based on the first information, that a target AS exists in a DN accessible to the UE; and the source ES sending a seventh notification message to the source AS, the seventh notification message including the address information of the target AS. For example, the target AS and the source AS serve the same application. Based on this scheme, by having the source AS subscribe to available AS notifications from the source ES, the source ES can send a notification message including the address information of the target AS to the source AS when the source ES determines that a target AS exists in a DN accessible to the UE. Since the user plane path of the UE's PDU session changes, the data network accessible to the UE may not necessarily have an AS serving the same application as the source AS. Therefore, by subscribing to the available AS notification, the source ES can notify the source AS only when it determines that an AS serving the same application exists in the data network accessible to the UE, thereby initiating application migration. This reduces invalid notifications during application migration and lowers latency. Understandably, when the source ES determines that the target AS exists in the DN accessible to the UE, the source ES sends a seventh notification message to the source AS.

[0091] In conjunction with the eleventh aspect, in one possible implementation, the location information of the UE is at least one of the following: the UE's IP address, the Data Network Access Identifier (DNAI) corresponding to the data network accessible to the UE, the UE's Tracking Area Identifier (TAI), the UE's Cell ID, the UE's Radio Access Network Identifier (RAN ID), or the UE's geographical location information. Based on this scheme, the source ES can determine the existence of a target AS in the DNs accessible to the UE based on the UE's IP address, DNAI, TAI, cell ID, RAN ID, or the UE's geographical location information, thus the determination result is relatively accurate.

[0092] In conjunction with the eleventh aspect and the above possible implementations, in another possible implementation, the source ES obtains the first information by receiving a third notification message from a Policy Control Function (PCF) entity or a Session Management Function (SMF) entity. This third notification message notifies the source ES that the user plane path of the UE's PDU session has changed, and the third notification message includes the aforementioned first information. Based on this scheme, by receiving the third notification message sent by the PCF or SMF, the source ES can learn that the user plane path of the UE's PDU session has changed, and thus the source ES can determine, based on the notification message, that a target AS exists in the DNs accessible to the UE.

[0093] In conjunction with the eleventh aspect and the above possible implementations, in another possible implementation, the method further includes: the source ES subscribing to user plane management event notifications from the PCF entity or the SMF entity. These user plane management event notifications are used to notify the source ES when the user plane path of the UE's PDU session changes. Based on this scheme, by having the source ES subscribe to user plane management event notifications from the PCF or SMF, the source ES can be notified when the PCF or SMF determines that the user plane path of the UE's PDU session has changed.

[0094] A twelfth aspect of this application provides a communication system including a source application server (AS) and a source enable server (ES). The source AS subscribes to user plane management event notifications from the source ES. These user plane management event notifications are used to notify the source AS when the user plane path of a UE's Protocol Data Unit (PDU) session changes. The source AS is the AS accessed by the UE before the user plane path of the PDU session changes. The source ES obtains first information, which is the location information of the UE after the user plane path of the UE's PDU session changes. The source ES sends a second notification message to the source AS, which is used to notify the source AS of the change in the user plane path of the UE's PDU session. The second notification message includes the first information. Based on the first information, the source AS determines a target AS and sends connection information of the target AS to the UE.

[0095] In conjunction with the twelfth aspect, in one possible implementation, the above-mentioned communication system further includes the above-mentioned UE, which receives connection information of the target AS from the source AS; the UE establishes a connection with the target AS based on the connection information of the target AS.

[0096] A thirteenth aspect of this application provides an application migration apparatus that has the function of implementing the application migration method described in any of the first to ninth aspects. This function can be implemented in hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-described function.

[0097] A fourteenth aspect of this application provides an application migration apparatus, comprising: a processor, a memory, a bus, and a communication interface; the memory is used to store computer execution instructions, the processor is connected to the memory via the bus, and when the application migration apparatus is running, the processor executes the computer execution instructions stored in the memory to cause the application migration apparatus to perform the application migration method as described in any of the first to ninth aspects above.

[0098] According to a fifteenth aspect of the present application, a computer-readable storage medium is provided that stores instructions which, when executed on a computer, enable the computer to perform the application migration method described in any of the first to ninth aspects.

[0099] According to a sixteenth aspect of the present application, the present application provides a computer program product containing instructions that, when run on a computer, enable the computer to perform the application migration method described in any of the first to ninth aspects.

[0100] According to a seventeenth aspect of the present application, a chip system is provided, the chip system including a processor and a memory, the memory storing instructions; when the instructions are executed by the processor, the application migration method described in any of the first to ninth aspects is implemented. Attached Figure Description

[0101] Figure 1 A schematic diagram of a 5G network architecture provided for an embodiment of this application;

[0102] Figure 2 A schematic diagram of an SA6 workgroup edge service enabling architecture provided in this application embodiment;

[0103] Figure 3 A schematic diagram of a network deployment architecture provided for an embodiment of this application;

[0104] Figure 4a A schematic diagram of a PDU session handover process in SSC mode3 provided in this application embodiment;

[0105] Figure 4b A schematic diagram of a PDU session switching process for a multi-homed session mechanism provided in this application embodiment;

[0106] Figure 5 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0107] Figure 6 A flowchart illustrating an application migration method provided in an embodiment of this application;

[0108] Figure 7 A flowchart illustrating another application migration method provided in an embodiment of this application;

[0109] Figure 8 A flowchart illustrating another application migration method provided in an embodiment of this application;

[0110] Figure 9A flowchart illustrating another application migration method provided in an embodiment of this application;

[0111] Figure 10 A flowchart illustrating another application migration method provided in this application embodiment;

[0112] Figure 11 A flowchart illustrating another application migration method provided in an embodiment of this application;

[0113] Figure 12 A flowchart illustrating another application migration method provided in an embodiment of this application;

[0114] Figure 13 A flowchart illustrating another application migration method provided in this application embodiment;

[0115] Figure 14 A flowchart illustrating another application migration method provided in this application embodiment;

[0116] Figure 15 A flowchart illustrating another application migration method provided in this application embodiment;

[0117] Figure 16 A flowchart illustrating another application migration method provided in this application embodiment;

[0118] Figure 17 A flowchart illustrating another application migration method provided in this application embodiment;

[0119] Figure 18 This is a schematic diagram of the composition of a communication device provided in an embodiment of this application;

[0120] Figure 19 This is a schematic diagram illustrating the composition of another communication device provided in an embodiment of this application;

[0121] Figure 20 This is a schematic diagram illustrating the composition of another communication device provided in an embodiment of this application;

[0122] Figure 21 This is a schematic diagram illustrating the composition of another communication device provided in an embodiment of this application. Detailed Implementation

[0123] The technical solutions in the embodiments of this application will be described below with reference to the accompanying drawings. In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple. Furthermore, to facilitate a clear description of the technical solutions in the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order. For example, the "first" in the first notification message and the "second" in the second notification message in the embodiments of this application are only used to distinguish different notification messages. The descriptions of "first" and "second" appearing in the embodiments of this application are only for illustration and to distinguish the described objects, and have no order, nor do they indicate a special limitation on the number of devices in the embodiments of this application, and cannot constitute any limitation on the embodiments of this application.

[0124] It should be noted that, in this application, the terms "exemplary" or "for example" are used to indicate that something is being described as an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0125] In the embodiments of this application, "multiple" refers to two or more.

[0126] The descriptions of "first," "second," etc., appearing in the embodiments of this application are for illustrative purposes and to distinguish the objects being described. They have no order and do not indicate any special limitation on the number of devices in the embodiments of this application, nor do they constitute any limitation on the embodiments of this application.

[0127] In this application embodiment, "connection" refers to various connection methods such as direct connection or indirect connection to realize communication between devices. This application embodiment does not limit this in any way.

[0128] In this application, "network" and "system" refer to the same concept, and the communication system is the same as the communication network.

[0129] The network architecture and business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0130] Figure 1 This is a schematic diagram of a 5G network architecture provided in an embodiment of this application. Figure 1 As shown, the user plane network elements and control plane network elements in this 5G network are deployed separately. This 5G network includes User Equipment (UE), access network (AN) equipment / radio access network (RAN) equipment, user plane function (UPF) entities and data network (DN), access and mobility management function (AMF) entities, session management function (SMF) entities, policy control function (PCF) entities and application function (AF), network slice selection function (NSSF) entities, authentication server function (AUSF) entities, and unified data management (UDM) entities.

[0131] Access network equipment refers to equipment that connects to the core network, such as base stations, broadband network gateways (BNGs), aggregation switches, and non-3GPP access equipment. Base stations can include various types, such as macro base stations, micro base stations (also known as small stations), relay stations, and access points.

[0132] The UPF entity is primarily responsible for PDU routing, forwarding, and policy enforcement for packet data. For example, a UPF entity can implement the user plane functions of a Serving Gateway (SGW) and a Packet Data Network Gateway (PGW). The UPF entity can also be a software-defined network (SDN) switch; this embodiment does not specifically limit its application to this. The UPF entity communicates with the DN via the N6 interface, where the DN is the destination for the user's PDU session access.

[0133] The AMF entity primarily accesses the UE's non-access stratum (NAS) signaling (including session management (SM) signaling) through the N1 interface and the radio access network signaling through the N2 interface, mainly responsible for access authentication, authorization, and mobility management.

[0134] The SMF entity communicates with the UPF entity through the N4 interface. The SMF entity is mainly responsible for completing the process of establishing, releasing, and updating sessions, as well as the allocation and management of network protocol (IP) addresses, the selection and control of the UPF entity, and session-related control functions such as lawful eavesdropping.

[0135] The PCF entity is primarily responsible for user policy management, including both mobility-related policies and protocol data unit (PDU) session-related policies, such as quality of service (QoS) policies and billing policies.

[0136] The AF (Agent Front-end) is primarily responsible for providing the PCF (Programmable Center) with service information about user access, which is used for the PCF's policy decisions. The NSSF (Network Slicing Service Provider) is primarily responsible for managing network slicing. The UDM (User DM) is primarily responsible for storing user subscription data. The AUSF (User Access Service Provider) is primarily responsible for authenticating and authorizing UE (User Equipment) access.

[0137] It should be noted that, Figure 1 The interface names between various network elements in the example are merely examples; in actual implementations, the interface names may be different, and this application embodiment does not specifically limit this. Optionally, the 5G network may also include, in addition to Figure 1 Other network devices besides those shown. Figure 1 This is merely an illustrative example.

[0138] It is understood that the application migration method provided in the embodiments of this application can be adapted to... Figure 1The 5G network shown can also be applied to long-term evolution (LTE) wireless communication networks or other next-generation (NG) communication networks, etc., and this application does not limit this. The following embodiments are only illustrated using 5G networks as an example.

[0139] Figure 2 An SA (System and architecture) 6 workgroup edge service enabling architecture provided in this application embodiment, such as Figure 2 As shown, the UE can access the edge data network (EDN) via the 5G network, which can also be called the local data network (LDN). This EDN can include an edge enabler server (EES) and an edge application server (EAS). The EES can be a control or management network element in a mobile edge computing (MEC) node. The EES is responsible for managing the EAS deployed in the EDN, such as registration and domain name system (DNS) resolution. The EES stores the configuration information (profile) of the EAS.

[0140] For example, each EDN has a specific service scope, and one or more EAS can be deployed in an EDN. Figure 2 This example illustrates the deployment of a single EAS within an EDN network. When multiple EASs are deployed in an EDN network, they can serve multiple different applications. For instance, three EASs might be deployed in the EDN network: EAS1, EAS2, and EAS3. EAS1 serves the Baidu application, EAS2 serves the iQiyi application, and EAS3 serves the Tencent Video application. Optionally, when multiple EASs are deployed in an EDN network, some or all of them can serve the same application for disaster recovery or load balancing. Another example: three EASs might be deployed in the EDN network: EAS1, EAS2, and EAS3. EAS1 and EAS2 serve the Baidu application, and EAS3 serves the Tencent Video application.

[0141] An edge configuration server (ECS) can be a global management network element responsible for maintaining information about various EDNs, including service scope and EES addresses. It should be noted that in some standard protocols (e.g., technical specifications (TS) 23.501, TS 23.502, etc.), the aforementioned EES, EAS, and ECS can all be referred to as AF.

[0142] The UE can include an edge enabler client (EEC) and an application client (AC). The EEC provides necessary support for the AC on the UE. The functions of the EEC include retrieving EDN information through the EDGE-4 interface, retrieving available EAS, EAS availability changes, notifying the EEC of EAS migration, and UE registration with the EES.

[0143] like Figure 2 As shown, the EEC in the UE can communicate with the EES through the EDGE-1 interface (edge ​​interface-1), the EEC in the UE can communicate with the AC in the UE through the EDGE-5 interface (edge ​​interface-5), the network element in the 5G network can communicate with the EES through the EDGE-2 interface (edge ​​interface-2), the network element in the 5G network can communicate with the ECS through the EDGE-8 interface (edge ​​interface-8), the EES deployed in the DN can communicate with the EAS through the EDGE-3 interface (edge ​​interface-3), and the ESC can communicate with the EES through the EDGE-6 interface (edge ​​interface-6).

[0144] It should be noted that the source AS or target AS in the following embodiments of this application can be Figure 2 In EAS, the source enabler server (ES) or the target ES can be... Figure 2 In the EES, CS can be Figure 2 In SA6, AS can be called EAS, ES can be called EES, and CS can be called ECS.

[0145] To improve user experience and reduce latency when users access application servers, operators or service providers may deploy application servers in prefecture-level cities or hotspot areas. Figure 3 This is a schematic diagram of a network deployment architecture provided in an embodiment of this application.

[0146] like Figure 3As shown, EAS1, EAS2, and EAS3 are deployed in MEC1 node or EDN1, EAS2, EAS3, and EAS4 are deployed in MEC2 node, and EAS1, EAS2, EAS3, and EAS4 are deployed in MEC3. Figure 3 In the PDU session anchor (PSA1), PSA1 connects to MEC1 / EDN1 (or PSA1 serves MEC1 / EDN1), PSA2 connects to MEC2, and PSA3 connects to MEC3. Each MEC has a corresponding service area, and the service areas of different MECs can overlap.

[0147] Figure 3 The same EAS service indicates the same application, while different EAS services indicate different applications. For example, Figure 3 EAS1, EAS2, EAS3, and EAS4 deployed in MEC1 serve different applications. EAS2 deployed in MEC1 and EAS2 deployed in MEC2 serve the same application; that is, EAS2 in MEC1 and EAS2 in MEC2 are different servers serving the same application. It should be noted that in actual deployments, more EAS instances can be deployed within a single MEC or EDN. Figure 3 This example illustrates the deployment of three or four EAS instances within a single MEC.

[0148] For example, 5G introduces three Session and Service Continuity (SSC) modes: SSC mode1, SSC mode2, and SSC mode3. For SSC mode1 PDU sessions, the network maintains the UPF that served as the PDU session anchor at the time of PDU session establishment, and the UE's IP address remains unchanged. For SSC mode2 PDU sessions, if the network needs to migrate the anchor UPF, it first releases the old PDU session and then initiates a new PDU session establishment process. For SSC mode3 PDU sessions, the network allows the establishment of a PDU session connection through the new anchor point before releasing the old anchor PDU session connection, thus ensuring service continuity.

[0149] Figure 4a This is a schematic diagram of a PDU session handover process provided in an embodiment of this application for SSC mode3. Figure 4aAs shown, for a PDU session in SSC mode 3, before the UE moves, it accesses the EAS in the EDN through UPF1. When the UE moves and the anchor UPF changes, the SMF notifies the UE to first establish a new PDU session with UPF2, and then disconnect the source PDU session when the timer expires. During the process of the UE's anchor UPF switching from UPF1 to UPF2, both sessions can transmit data simultaneously. The UE's old IP address corresponds to UPF1, and the UE's new address corresponds to UPF2. It should be noted that the EDN accessed after the UE moves can be the same as or different from the EDN accessed before the UE moves. That is, the data network accessed after the UE moves may change or remain the same. Figure 4 illustrates this only if the EDN accessed after the UE moves remains unchanged.

[0150] Figure 4b This is a schematic diagram of a PDU session switching process for a multi-homed session mechanism provided in an embodiment of this application. Figure 4b As shown, when using the multi-homed session creation mechanism to implement SSC mode 3, before the UE moves, it accesses the AS in the DN through UPF1. When the UE moves and the anchor point UPF is switched, a branching point UPF and UPF2 are created. During the switching process, the branching point UPF is connected to UPF1 and UPF2. After the switching is completed, UPF1 and the connection between the branching point UPF and UPF2 are released.

[0151] It should be noted that the above Figure 1 In Figure 4, AMF, SMF, PCF, UPF, EDN, EAS, and EES are merely names and do not limit the devices themselves. In 5G networks and other future networks, AMF, SMF, PCF, UPF, EDN, EAS, and EES may also be other names, and this application embodiment does not specifically limit them.

[0152] Combination Figure 3 As shown in Figure 4, when the SSC mode of the UE's PDU session is SSC mode3, if the UE needs to switch UPF during movement, the corresponding application server can also be switched to reduce the latency of accessing the application.

[0153] During UE mobility, to reduce latency when the UE accesses the application server, one application migration method based on SSC mode 3 involves the OS on the UE discovering a new PDU session. The OS then notifies the AC (Application Server). Upon receiving this notification, the AC triggers a DNS query to obtain the New EAS (Application Server Address). The AC sends the New EAS address to the Old EAS, instructing the Old EAS to perform application migration. After state synchronization between the Old EAS and the New EAS, the UE begins sending data packets to the New EAS. However, this method, based on DNS queries to determine the New AS, suffers from inaccuracies. The New AS determined by the DNS query is not always the most suitable application server, leading to significant latency when migrating the UE to the New AS. Furthermore, this application migration method requires an additional interface between the OS and the AC, and the AC needs to understand SSC mode 3 to initiate a DNS query to determine the New EAS and send its address to the Old EAS to trigger application handover upon receiving notification from the OS. Therefore, this scheme necessitates enhanced AC logic, resulting in significant design complexity for the AC.

[0154] To address the issue of inaccurate target AS identification in the application migration method, which leads to significant latency for UE accessing the application server, this application provides an application migration method that can more accurately identify the target AS, thereby reducing the latency for UE accessing the application server.

[0155] In practical implementation, the application migration method provided in this application can employ source AS, source ES, target AS, target ES, CS, and UE, etc. Figure 5 The shown composition structure, or including Figure 5 The components shown.

[0156] For example, Figure 5 This is a schematic diagram illustrating the composition of a communication device 500 provided in an embodiment of this application. Figure 5 As shown, the communication device 500 may include at least one processor 501, a memory 502, a transceiver 503, and a communication bus 504.

[0157] The following is combined with Figure 5 The various components of the communication device 500 are described in detail below:

[0158] Processor 501 is the control center of communication device 500. It can be a single processor or a collective term for multiple processing elements. For example, processor 501 can be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application, such as one or more digital signal processors (DSPs), or one or more field-programmable gate arrays (FPGAs).

[0159] The processor 501 can perform various functions of the communication device by running or executing software programs stored in the memory 502 and calling data stored in the memory 502.

[0160] In a specific implementation, as one example, the processor 501 may include one or more CPUs, for example... Figure 5 CPU0 and CPU1 are shown in the diagram.

[0161] In a specific implementation, as one example, the communication device 500 may include multiple processors, such as... Figure 5 The processors 501 and 505 are shown. Each of these processors can be a single-core processor or a multi-core processor. Here, "processor" can refer to one or more communication devices, circuits, and / or processing cores used to process data (e.g., computer program instructions).

[0162] Memory 502 may be a read-only memory (ROM) or other type of static storage communication device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage communication device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage communication devices, or any other medium capable of including or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. Memory 502 may exist independently and be connected to processor 501 via communication bus 504. Memory 502 may also be integrated with processor 501.

[0163] The memory 502 stores the software program that executes the solution of this application, and its execution is controlled by the processor 501. The processor 501 executes the application program code stored in the memory 502, thereby implementing the application migration method provided in the following embodiments of this application.

[0164] Transceiver 503 is used for communication with an access point. Of course, transceiver 503 can also be used to communicate with a communication network, such as Ethernet, radio access network (RAN), wireless local area network (WLAN), etc. Transceiver 503 may include a receiving unit to implement the receiving function and a transmitting unit to implement the transmitting function.

[0165] The communication bus 504 can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. This bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 5 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0166] It should be noted that the communication device 500 can be a general-purpose communication device or a dedicated communication device. In specific implementations, the communication device 500 can be a desktop computer, a laptop computer, a network server, a mobile phone, a tablet computer, a wireless terminal, an embedded device, a chip system, or something else. Figure 5 Devices with similar structures. This application does not limit the type of communication device 500. Furthermore, Figure 5 The structural composition shown does not constitute a limitation on the communication device, except... Figure 5 In addition to the components shown, the communication device may include more or fewer components than illustrated, or combine certain components, or have different component arrangements.

[0167] For example, the UE in this application embodiment can be various handheld devices, vehicle-mounted devices, wearable devices, computing devices, or other processing devices connected to a wireless modem with wireless communication capabilities; it can also include a subscriber unit, cellular phone, smartphone, wireless data card, personal digital assistant (PDA) computer, tablet computer, wireless modem, handheld device, laptop computer, cordless phone, wireless local loop (WLL) station, machine type communication (MTC) terminal, user equipment (UE), mobile station (MS), terminal device, etc. For ease of description, the devices mentioned above are collectively referred to as UE in this application.

[0168] The following will combine Figures 1 to 5 The application migration method provided in the embodiments of this application will be described in detail.

[0169] Combination Figures 1-5 ,like Figure 6 The image shown illustrates an application migration method provided in an embodiment of this application. Figure 6 As shown, the method for migrating the application includes steps S601-S604.

[0170] S601, Source AF obtains the first information.

[0171] The first information refers to the UE's location information after the user plane path of the UE's PDU session changes. This location information can be the UE's IP address, the data network access identity (DNAI) corresponding to the user plane path of the UE's PDU session, or the UE's identification information in the network (e.g., cell ID, RAN ID, track area ID (TAI), geographic location information, etc.). It is understood that the DNAI corresponding to the user plane path of the UE's PDU session is the DNAI corresponding to the data network that the UE can access. For example, the first information could be the UE's IP address after reconstructing the PDU session or the UE's IP address corresponding to the newly inserted anchor point UPF when using the multi-homed session creation mechanism to implement SSC mode 3. Another example is the DNAI corresponding to the UPF after the UE reconstructs the PDU session. Yet another example is the information of the base station to which the UE attaches after moving, such as the cell ID. This application embodiment does not limit the specific content of the first information. It should be noted that in the scenario of SSC mode 3 session reconstruction, the DNAI corresponding to the data network that the UE can access can be understood as the DNAI corresponding to the UPF after the UE reconstructs the PDU session, or the DNAI corresponding to the newly inserted anchor UPF when using the multi-homed session creation mechanism to implement SSC mode 3.

[0172] For example, DNAI can be used to identify the path between the UPF and the data network; that is, DNAI can be used to determine the UPF or DN. For instance, the relationship between DNAI and UPF can be stored on the SMF, allowing the SMF to determine the UPF based on the DNAI, and conversely, the SMF can also determine the corresponding DNAI based on the UPF. Therefore, when the UE reconstructs the PDU session, if the UPF changes, the DNAI corresponding to the UPF will also change. Since the SMF needs to consider the UE's location information when selecting the UPF, DNAI can also be considered a type of UE location information. Alternatively, the relationship between DNAI and DN can be stored on the SMF or other network elements such as AF, allowing the SMF or AF to determine the DN based on the DNAI, and conversely, the SMF can also determine the corresponding DNAI based on the DN.

[0173] For example, in step S601 above, the source AF can obtain the first information when the user plane path of the UE's PDU session changes.

[0174] The user plane path of the UE's PDU session mentioned above refers to the path from the UE to the base station and then to the UPF entity. Changes in the user plane path of the UE's PDU session can include the following situations: First, the UPF changes. A UPF change includes a change in the anchor UPF, which can be understood as a change in the UE's PDU session anchor point. When the UPF changes, the UE's IP address also changes, or the data network that the UE can access changes, i.e., the DNAI that the UE can access changes. Second, the UPF remains unchanged, but the base station changes. Third, both the UPF and the base station change. In this application embodiment, the user plane path change of the UE's PDU session can be any of the above situations, and this application embodiment does not limit this. The following embodiment only illustrates the case where the change in the user plane path of the UE's PDU session leads to the reconstruction of the UE's PDU session. That is, if the UE's PDU session is reconstructed, the user plane path of the UE's PDU session changes, and the source AF obtains the first information.

[0175] For example, the aforementioned source AF can be either a source AS or a source ES. This source AS or source ES is the AS or ES accessed by the UE before the user plane path of the PDU session changes. For instance, before the UE's PDU session is rebuilt, the UE accesses the AS of Tencent Video, and this Tencent Video AS is the source AS. Optionally, the source AS can be... Figure 2 EAS in the source ES can be Figure 2 EES in.

[0176] For example, when the source AF in step S601 is the source AS, the source AF obtaining the first information in step S601 is the source AS obtaining the first information. The first information obtained by the source AS can come from core network elements (e.g., AMF entity, UPF entity, PCF entity or SMF entity), or it can come from the source ES.

[0177] In the first implementation, when the first information obtained by the source AS comes from the PCF entity or the SMF entity, before step S601, the source AS can subscribe to a User plane management event notification from the PCF entity or the SMF entity. This User plane management event notification is used to notify the source AS when the User plane path of the UE's PDU session changes. When the User plane path of the UE's PDU session changes, the PCF entity or the SMF entity sends a first notification message to the source AS to indicate the change in the User plane path of the UE's PDU session. This first notification message may include the first information.

[0178] In the second implementation, when the first information obtained by the source AS comes from the source ES, before step S601, the source AS can subscribe to user plane management event notifications from the source ES. These user plane management event notifications are used to notify the source AS when the user plane path of the UE's PDU session changes. When the user plane path of the UE's PDU session changes, the source ES sends a second notification message to the source AS to indicate the change in the user plane path of the UE's PDU session. This second notification message may include the first information. Optionally, the source ES can learn of the change in the user plane path of the UE's PDU session through a PCF entity, an SMF entity, or the UE itself.

[0179] In the third implementation, when the first information obtained by the source AS comes from a core network element, before step S601, the source AS can subscribe to user plane management event notifications from the source ES. These user plane management event notifications are used to notify the source AS when the user plane path of the UE's PDU session changes. When the user plane path of the UE's PDU session changes, the source ES sends a second notification message to the source AS to indicate the change. This second notification message may include the first information; if the second notification message does not include the first information, the source AS, after receiving the second notification message, can send a request message to a core network element (e.g., an AMF entity, SMF entity, or UPF entity) to obtain the aforementioned first information. That is, in this implementation, the first information is not included in the second notification message sent by the source ES, but is obtained by the source AS after receiving the second notification message from the source ES by sending a request message to the core network element.

[0180] For example, when the source AF in step S601 is the source ES, the source AF obtaining the first information in step S601 is the source ES obtaining the first information. The first information obtained by the source ES can come from the PCF entity or the SMF entity, or it can come from the UE.

[0181] In the first implementation, when the first information obtained by the source ES comes from the PCF entity or the SMF entity, before step S601, the source ES can subscribe to user plane management event notifications from the PCF entity or the SMF entity. These user plane management event notifications are used to notify the source ES when the user plane path of the UE's PDU session changes. When the user plane path of the UE's PDU session changes, the PCF entity or the SMF entity sends a third notification message to the source ES to indicate the change in the user plane path of the UE's PDU session. This third notification message may include the aforementioned first information.

[0182] In the second implementation, when the first information obtained by the source ES comes from the UE, step S601 includes: the source ES receiving a fourth notification message sent by the UE's EEC to instruct the UE to re-establish the PDU session, the fourth notification message including the aforementioned first information. Optionally, the first information obtained by the source ES can also be obtained by requesting it from the 5GC after receiving the fourth notification message sent by the UE's EEC.

[0183] Optionally, when the first information is not included in the third or fourth notification message, the source ES may also send a request to a core network element (e.g., an AMF entity, an SMF entity, or a UPF entity) to obtain the first information.

[0184] It should be noted that the embodiments of this application do not limit which of the above-mentioned implementation methods is used for the source AF to obtain the first information.

[0185] S602, the source AF determines the target AS based on the first information.

[0186] The target AS serves the same application as the source AS. For example, if the source AS is the Tencent Video app, then the target AS is also the Tencent Video app; that is, both the source and target ASs can serve the Tencent Video app. After migrating the UE's context from the source AS to the target AS, the target AS can continue to provide services to the UE. In other words, the source and target ASs are two application servers that can serve the same application.

[0187] Optionally, the target AS and the source AS can have the same application identifier (edge ​​application server ID, EAS ID).

[0188] In one implementation, the fact that the target AS and the source AS offer the same application indicates that the services provided by the two application servers are consistent; both the source AS and the target AS can only provide Tencent Video service. In another implementation, the target AS and the source AS offer the same application, but the services provided by the two application servers are different. For example, the source AS can provide Tencent Video service, while the target AS can provide both Tencent Video service and Tencent Maps service. For instance, before the UE moves, the UE connects to the source AS to access Tencent Video service; after the application migration, the target AS can continue to provide Tencent Video service.

[0189] Optionally, the source AS and the target AS can be deployed in the same data network or in different data networks. For example, if the data network switches when the user plane path of the UE's PDU session changes, then the source AS is the application server deployed in the source data network (the data network before the switch), and the target AS is the application server deployed in the target data network (the data network after the switch). As another example, if the UE's PDU session accesses the same data network before and after the user plane path change, then the source AS and the target AS are two servers deployed in that data network and serving the same application. This application embodiment only illustrates the example of the source AS and the target AS being deployed in different data networks. When the source AS and the target AS are the source EAS and the target EAS, respectively, the source AS and the target AS are deployed in different edge data networks (EDNs) and serve the same application.

[0190] For example, in step S602 above, the source AF determining the target AS based on the first information may include: the source AF obtaining information about the UPF entity after the user plane path of the UE's PDU session has changed based on the first information; and the source AF determining the target AS based on the information of the UPF entity. For example, taking the UE's IP address as the first information and the DNAI as the information of the UPF entity as the DNAI, after obtaining the UE's IP address, the source AF can send a request to the 5GC based on the UE's IP address to obtain the UE's DNAI, and determine the target AS based on the DNAI.

[0191] For example, the source AF determines the target AS based on DNAI by: the source AF determining a new PSA based on DNAI, then determining the MEC connected to the new PSA, and then selecting the EAS deployed in the MEC as the target AS.

[0192] For example, the source AF stores the relationship between first information and the target AS. The source AF queries this mapping relationship based on the obtained first information to determine the target AS. The storage format of this mapping relationship can be a relational table, context, key-value pairs, etc., and this application embodiment does not limit this. For example, if the source AF stores the relationship between the target AS and the service range information corresponding to the target AS, then after obtaining the UE's location information, the source AF can determine which AS's service range protects the UE's location, i.e., determine that AS as the target AS. Alternatively, if the source AF stores the correspondence between the target AS and DNAI, then the source AF obtains the DNAI corresponding to the UPF entity after the user plane path change, thereby determining the target AS. Or, if the source AF stores the correspondence between the target AS and an IP address or IP address range, then the source AF obtains the UE's new IP address after the user plane path change, thereby determining the target AS. This application embodiment does not limit the specific implementation method of how the source AF determines the target AS based on the first information; this is merely an illustrative example.

[0193] (Optional) S603, The source AF sends the connection information of the target AS to the UE.

[0194] The connection information of the target AS includes the address information of the AS, which can be the IP address of the target AS, the Uniform Resource Identifier (URI) or Uniform Resource Locator (URL) of the target AS, the endpoint of the target AS, etc.

[0195] For example, the source AS can send the connection information of the target AS to the UE's AC.

[0196] For example, in step S603 above, the connection information of the target AS can be sent from the source AS to the UE; or the connection information of the target AS can be sent from the source ES to the UE; or the source AS can send the connection information of the target AS to the source ES, and then the source ES sends the connection information of the target AS to the UE; or other network devices can send the connection information of the target AS to the UE. This application embodiment does not limit this.

[0197] Optionally, the connection information of the target AS sent from the source AF to the UE in step S603 above may be included in the application layer message or in the non-access stratum (NAS) signaling. This embodiment of the application does not limit this. For example, when the connection information of the target AS is included in the NAS signaling, the process of the source AF sending the connection information of the target AS to the UE in step S603 above may include: the source AF sending the connection information of the target AS to the 5GC (e.g., AMF, SMF, PCF), and the 5GC sending the connection information of the target AS to the UE through NAS signaling.

[0198] (Optional) S604. The UE receives the connection information of the target AS and establishes a connection with the target AS.

[0199] For example, after the AC in the UE receives the connection information of the target AS, the AC establishes a Socket, and the OS in the UE selects the target AS according to the connection information of the target AS and establishes a connection.

[0200] Optionally, the connection information of the target AS received by the UE in step S604 can come from the source ES. For example, before step S604, the UE can request the target AS information from the source ES. After receiving the UE's request, the source ES sends the target AS connection information to the UE. Optionally, the UE sends the above request to the source ES after learning that the user plane path of its PDU session has changed.

[0201] Optionally, step S603 above may also include triggering an application migration from the source AF. This application migration is also called application handover or state migration. Application migration refers to migrating the UE's context from the source AS to the target AS. This application migration can be understood as state synchronization (context synchronization) between the source AS and the target AS. For example, before the user plane path of the UE's PDU session changes, the UE accesses the source AS corresponding to the Tencent Video APP to watch a video. The video being watched is at the 30-minute mark. When the source AF triggers the application migration, the source AS and the target AS perform context synchronization. If the migration is successful, the UE starts accessing the target AS and continues watching the video at the 30-minute mark.

[0202] Optionally, the ES accessed after the UE moves can be the same as or different from the ES accessed before the move. If the ES accessed after the UE moves changes, then the ES accessed before the UE moves is the source ES, and the ES accessed after the UE moves is the target ES.

[0203] Understandably, in this embodiment, when the user plane path of the UE's PDU session changes, the location information of the UE after the change is obtained through the source AF, and the target AS can be determined and application migration is triggered based on the UE's location information. This scheme determines the target AS based on the UE's location information after the change of the user plane path of the UE's PDU session with relatively high accuracy, thus reducing the latency when the UE accesses the target AS. Furthermore, this scheme does not require the AC in the UE to receive a notification from the OS instructing the UE to rebuild the session, initiate a DNS query, and obtain the address of the target AS. That is, this scheme triggers the reselection of the target AS and application migration by the network-side device, without modifying the AC in the UE. Therefore, it does not require the AC to understand network logic, simplifying the design of the AC.

[0204] The various implementation methods of the application migration method provided in the embodiments of this application will be described in detail below.

[0205] The flowchart of the application migration method provided in this application embodiment is shown below. Figure 7 As shown, the interaction between the source AS, PCF entity / SMF entity, and UE involves the following steps:

[0206] S701, the source AS subscribes to user plane management event notifications from the PCF entity or SMF entity.

[0207] This user plane management event notification is used to notify the source AS when the user plane path of the UE's PDU session changes.

[0208] For example, the source AS can subscribe to user plane management event notifications directly from the PCF entity or directly from the SMF entity. It should be noted that since the change of the user plane path of the UE's PDU session is managed by the SMF, when the source AS subscribes to user plane management events from the PCF, the PCF can subscribe to user plane management events from the SMF. Therefore, when the SMF determines to change the user plane path of the UE's PDU session, the SMF can notify the PCF, and the PCF can then notify the source AS. Optionally, when the SMF determines to change the user plane path of the UE's PDU session, it can also directly notify the source AS.

[0209] Optionally, before step S701 above, the source AS may request to establish a policy association with the PCF entity or SMF entity, and the PCF entity or SMF entity may send a session mode to the source AS, which may be SSCmode 3.

[0210] S702, PCF entity or SMF entity sends the first notification message to the source AS.

[0211] The first notification message is used to notify the source AS that the user plane path of the UE's PDU session has changed. That is, when the PCF entity or SMF entity determines that the user plane path of the UE's PDU session has changed, the PCF entity or SMF entity sends this first notification message to the source AS. Optionally, the first notification message may include first information. A description of the first information can be found in the foregoing embodiments and will not be repeated here.

[0212] When the SSC mode of the UE's PDU session is SSC mode3, the user plane path change of the UE's PDU session includes the reconstruction of the UE's PDU session.

[0213] For example, a change in the user plane path of a UE's PDU session can be triggered based on UE mobility or load balancing. For instance, such as... Figure 3 As shown, taking the UE's IP address as the first piece of information as an example, when the UE accesses EAS2 in MEC1, the session anchor UPF is PSA1, and the UE's IP address is IP@1. If the UE moves to the service range of MEC2, the SMF decides to rebuild the PDU session and sends an instruction to the UE to create a new session. Optionally, this instruction may include a timer; when the timer expires, the old PDU session is released. Correspondingly, the UE initiates a request to create a session. After receiving the session request, the SMF selects a new session anchor UPF for the current session, namely PSA2, and assigns a new IP address IP@2 to the UE. The SMF sends the new IP address IP@2 to the PCF, and the PCF sends the new IP address IP@2 to the source AS.

[0214] It should be noted that the SMF of the PDU session before reconstruction (the old PDU session) and the reconstructed PDU session (the new PDU session) can be the same or different. In other words, the SMF can be changed or left unchanged when reconstructing the PDU session.

[0215] For example, when rebuilding a PDU session does not change the SMF, the SMF can associate the old PDU session (the PDU session before rebuilding) and the new PDU session (the PDU session after rebuilding). The SMF can send the new IP address or the DNAI corresponding to the anchor point PSA2 of the new PDU session or the location information of the UE to the source AS.

[0216] For example, when the SMF is changed during PDU session reconstruction, the old SMF (i.e., the SMF before PDU session reconstruction) sends PCF information to the AMF. The AMF then sends this PCF information to the new SMF (the SMF after PDU session reconstruction). The new SMF selects the same PCF based on this PCF information. That is, although the SMF is changed during PDU session reconstruction, the PCF remains unchanged. Therefore, the PCF can be used to associate the new and old PDU sessions, and it can send the new IP address, new DNAI, or UE location information to the source AS.

[0217] Understandably, the first notification message in step S702 is a response to the user plane management event notification subscribed by the source AS to the PCF entity or SMF entity in step S701.

[0218] S703, the source AS receives the first notification message.

[0219] S704. The source AS determines the target AS based on the first information.

[0220] For example, when the first notification message includes first information, the source AS can determine the target AS based on the first information included in the first notification message. Optionally, when the first notification message does not include first information, before step S704, after receiving the first notification message, the source AS can send a request to the 5GC network element to obtain the first information, and determine the target AS based on the first information obtained from the 5GC network element. For example, the source AS can obtain UE location information from the AMF entity, or obtain the DNAI corresponding to the UPF of the currently serving UE from the SMF entity, or obtain the IP address of the current UE from the SMF entity or UPF entity, etc.

[0221] Understandably, in step S704 above, the source AS determines the specific implementation method of the target AS based on the first information. This can be referred to in step S602, where the source AF determines the implementation method of the target AS based on the first information. It will not be repeated here.

[0222] S705, Source AS triggers application migration.

[0223] Application migration refers to migrating the application server accessed by the UE from the source AS to the target AS.

[0224] Optionally, step S705 can also be triggered by the source ES to initiate the application migration. When step S705 is triggered by the source ES to initiate the application migration, the process can further include the source AS sending connection information of the target AS to the source ES before step S705, so that the source ES migrates the UE's context from the source AS to the target AS based on the connection information of the target AS. That is, in this embodiment, the device that determines the target AS and the device that triggers the application migration can be the same device or different devices.

[0225] Understandable. Figure 7 Step S705 is an optional step.

[0226] S706. The source AS sends the connection information of the target AS to the UE.

[0227] Understandably, the relevant description of the connection information of the target AS can be found in step S603, and will not be repeated here.

[0228] S707. The UE receives the connection information of the target AS and establishes a connection with the target AS.

[0229] For example, after the AC in the UE receives the connection information of the target AS, the AC establishes a Socket, and the OS in the UE selects the target AS according to the connection information of the target AS and establishes a connection.

[0230] Optionally, if the source AS still receives data packets from the UE after the application migration is complete, the source AS can forward the received data packets to the target AS.

[0231] It should be noted that this application does not impose any limitation on the order in which steps S701-S707 are performed. Figure 7 This is merely an illustrative example.

[0232] Understandably, the application migration method provided in this application subscribes to user plane event management notifications from the core network element via the source AS. This allows the method to receive a first notification message from the core network element when the user plane path of the UE's PDU session changes. Based on the first information included in the first notification message, the method determines the target AS and triggers application migration. This method accurately determines the target AS based on the UE's location information after the user plane path of the UE's PDU session changes, resulting in lower latency when the UE accesses the target AS. Furthermore, since the method triggers the reselection of the target AS and application migration from the source AS, it does not modify the AC in the UE. Therefore, it does not require the AC to understand network logic, simplifying AC design.

[0233] The flowchart of the application migration method provided in this application embodiment is shown below. Figure 8 As shown, the interaction between the source ES, PCF entity / SMF entity, and UE involves the following steps:

[0234] S801, Source ES subscribes to user plane management event notifications from PCF entity or SMF entity.

[0235] This user plane management event notification is used to notify the source ES when the user plane path of the UE's PDU session changes.

[0236] For example, the source ES can subscribe to user plane management event notifications directly from the PCF entity or directly from the SMF entity. It should be noted that since the change of the user plane path of the UE's PDU session is managed by the SMF, when the source ES subscribes to user plane management events from the PCF, the PCF can subscribe to user plane management events from the SMF. Therefore, when the SMF determines to change the user plane path of the UE's PDU session, the SMF can notify the PCF, and the PCF can then notify the source ES. Optionally, when the SMF determines to change the user plane path of the UE's PDU session, it can also directly notify the source ES.

[0237] Optionally, before step S801 above, the source ES may request to establish a policy association with the PCF entity or SMF entity, and the PCF entity or SMF entity may send a session mode to the source ES, which may be SSCmode 3.

[0238] S802, PCF entity or SMF entity sends a third notification message to the source ES.

[0239] The third notification message is used to notify the source ES that the user plane path of the UE's PDU session has changed. That is, when the PCF entity or SMF entity determines that the user plane path of the UE's PDU session has changed, the PCF entity or SMF entity sends this third notification message to the source ES. Optionally, the third notification message may include first information. A description of the first information can be found in the foregoing embodiments and will not be repeated here.

[0240] Understandably, the third notification message in step S802 is a response to the user plane management event notification subscribed to by the source ES from the PCF entity or SMF entity in step S801.

[0241] S803, the source ES receives the third notification message.

[0242] S804, the source ES determines the target AS based on the first information.

[0243] For example, when the third notification message includes the first information, the source AS can determine the target AS based on the first information included in the third notification message. Optionally, when the third notification message does not include the first information, after receiving the third notification message, the source AS can send a request to the 5GC network element to obtain the first information, and determine the target AS based on the first information obtained from the 5GC network element. For example, the source ES can obtain UE location information from the AMF entity, or obtain the DNAI corresponding to the UPF of the currently serving UE from the SMF entity, or obtain the IP address of the current UE from the SMF entity or UPF entity, etc.

[0244] Understandably, in step S804 above, the source ES determines the specific implementation method of the target AS based on the first information. This can be referred to in step S602, where the source AF determines the implementation method of the target AS based on the first information. It will not be repeated here.

[0245] S805, source ES triggers application migration.

[0246] Application migration refers to migrating the application server accessed by the UE from the source AS to the target AS.

[0247] Optionally, step S805 can also be triggered by the source AS for application migration. When step S805 is triggered by the source AS for application migration, before step S805, the source ES may send connection information of the target AS to the source AS, so that the source AS can migrate the UE's context from the source AS to the target AS based on the connection information of the target AS.

[0248] Understandable. Figure 8 Step S805 is an optional step.

[0249] S806, the source ES sends the connection information of the target AS to the UE.

[0250] The connection information for the target AS includes the address information of the target AS. This connection information can be the IP address of the target AS, the URI of the target AS, the URL of the target AS, or the endpoint of the target AS, etc.

[0251] For example, the source ES can send the connection information of the target AS to the AC in the UE.

[0252] S807. The UE receives the connection information of the target AS and establishes a connection with the target AS.

[0253] Understandably, the specific implementation of steps S806-S807 can be found in steps S706-S707, and will not be repeated here.

[0254] It should be noted that this application does not impose any limitation on the order in which steps S801-S807 are performed. Figure 8 This is merely an illustrative example.

[0255] As is understood, the application migration method provided in this application subscribes to user plane event management notifications from the core network element through the source ES, thereby enabling it to receive a third notification message sent by the core network element when the user plane path of the UE's PDU session changes. Based on the first information included in the third notification message, the method determines the target AS and triggers application migration. This method accurately determines the target AS based on the UE's location information after the user plane path of the UE's PDU session changes, resulting in lower latency when the UE accesses the target AS. Furthermore, since the method triggers the reselection of the target AS and application migration from the source ES, it does not modify the AC in the UE. Therefore, it does not require the AC to understand network logic, simplifying AC design.

[0256] The flowchart of the application migration method provided in this application embodiment is shown below. Figure 9 As shown, the interaction between the source AS, source ES, PCF entity / SMF entity, and UE involves the following steps:

[0257] S901, Source AS subscribes to user plane management event notifications from Source ES.

[0258] This user plane management event notification is used to notify the source AS when the user plane path of the UE's PDU session changes.

[0259] S902, Source ES subscribes to user plane management event notifications from PCF entity or SMF entity.

[0260] This user plane management event notification is used to notify the source ES when the user plane path of the UE's PDU session changes.

[0261] S903, PCF entity or SMF entity sends a third notification message to the source ES.

[0262] The third notification message is used to notify the source ES that the user plane path of the UE's PDU session has changed. That is, when the PCF entity or SMF entity determines that the user plane path of the UE's PDU session has changed, the PCF entity or SMF entity sends this third notification message to the source ES. Optionally, the third notification message may include first information. A description of the first information can be found in the foregoing embodiments and will not be repeated here.

[0263] Understandably, the third notification message in step S903 is a response to the user plane management event notification subscribed to by the source ES to the PCF entity or SMF entity in step S902.

[0264] S904, the source ES receives the third notification message.

[0265] S905, the source ES sends a second notification message to the source AS.

[0266] The second notification message is used to notify the source AS that the user plane path of the UE's PDU session has changed. That is, when the source ES determines that the user plane path of the UE's PDU session has changed, the source ES sends this second notification message to the source AS. Optionally, the second notification message may include first information. This first information may be the UE's DNAI after the user plane path of the UE's PDU session has changed.

[0267] Understandably, the second notification message in step S905 is a response to the user plane management event notification subscribed by the source AS to the source ES in step S901.

[0268] S906, the source AS receives the second notification message.

[0269] S907. The source AS determines the target AS based on the first information.

[0270] For example, when the second notification message includes the first information, the source AS can determine the target AS based on the first information included in the second notification message. Optionally, when the second notification message does not include the first information, after receiving the second notification message, the source AS can send a request to the 5GC network element to obtain the first information, and determine the target AS based on the first information obtained from the 5GC network element.

[0271] Understandably, in step S907 above, the source AS determines the specific implementation method of the target AS based on the first information. This can be referred to in step S602, where the source AF determines the implementation method of the target AS based on the first information. It will not be repeated here.

[0272] S908, Source AS triggers application migration.

[0273] Application migration refers to migrating the application server accessed by the UE from the source AS to the target AS.

[0274] Optionally, step S908 can also be triggered by the source ES to initiate the application migration. When step S908 is triggered by the source ES to initiate the application migration, the step S908 can also include the source AS sending connection information of the target AS to the source ES, so that the source ES can migrate the UE's context from the source AS to the target AS based on the connection information of the target AS.

[0275] Understandable. Figure 9 Step S908 is an optional step.

[0276] S909, The source AS sends the connection information of the target AS to the UE.

[0277] S910, the UE receives the connection information of the target AS and establishes a connection with the target AS.

[0278] Understandably, the specific implementation of steps S909-S910 can be found in steps S706-S707, and will not be repeated here.

[0279] It should be noted that this application does not impose any restrictions on the order in which steps S901-S910 are performed. Figure 9 This is merely an illustrative example.

[0280] As is understood, the application migration method provided in this application involves the source AS subscribing to user plane event management notifications from the source ES, and the source ES subscribing to user plane event management notifications from the core network elements. This allows the source ES to receive notification messages from the core network elements and send notifications to the source AS when the user plane path of the UE's PDU session changes. The source AS can then determine the target AS based on the first information included in the notification sent by the source ES and trigger application migration. This method accurately determines the target AS based on the UE's location information after the user plane path of the UE's PDU session changes, resulting in lower latency when the UE accesses the target AS. Furthermore, since the method triggers the reselection of the target AS and application migration from the source AS, it does not modify the AC in the UE. Therefore, it does not require the AC to understand network logic, simplifying AC design.

[0281] The flowchart of the application migration method provided in this application embodiment is shown below. Figure 10 As shown, the interaction between the source AS, source ES, EEC in the UE, OS in the UE, and AC in the UE includes the following steps:

[0282] S1001, Source AS subscribes to user plane management event notifications from Source ES.

[0283] This user plane management event notification is used to notify the source AS when the user plane path of the UE's PDU session changes. It is understood that a change in the user plane path of the UE's PDU session includes PDU session reconstruction.

[0284] S1002, The EEC in the UE subscribes to the OS in the UE for a session reconstruction event notification.

[0285] This session rebuild event notification is used to notify the EEC in the UE when the UE's PDU session is rebuilt.

[0286] S1003, the OS in the UE sends a sixth notification message to the EEC in the UE.

[0287] The sixth notification message is used to notify the EEC in the UE that the UE's PDU session has been rebuilt. That is, when the OS in the UE determines that the UE's PDU session has been rebuilt, the OS in the UE sends this sixth notification message to the EEC in the UE. Optionally, the sixth notification message includes first information.

[0288] Understandably, the sixth notification message in step S1003 is a response to the session reconstruction event notification from the EEC in the UE to the OS in the UE in step 1002.

[0289] S1004, the EEC in the UE receives the sixth notification message.

[0290] S1005, the EEC in the UE sends a fourth notification message to the source ES.

[0291] This fourth notification message is used to notify the source ES of the UE's PDU session reconstruction. Specifically, when the EEC in the UE determines that the UE's PDU session is being reconstructed, the EEC in the UE sends this fourth notification message to the source ES. Optionally, this fourth notification message includes the first information.

[0292] Optionally, the fourth notification message sent by the EEC in the UE to the source ES in step S1005 may include a new DNAI, and / or a new IP address, and / or the UE's location identification information in the network.

[0293] S1006, Source ES receives the fourth notification message.

[0294] Optionally, when the fourth notification message does not include the first information, the source ES can send a request to the 5GC network element (such as the AMF entity or SMF entity) to obtain the first information, such as obtaining the UE's location identifier information in the network from the AMF entity, or obtaining the DNAI corresponding to the UPF of the current serving UE from the SMF entity, or obtaining the IP address of the current UE from the SMF entity or UPF entity.

[0295] S1007, Source ES sends a second notification message to Source AS.

[0296] The second notification message is used to notify the source AS that the user plane path of the UE's PDU session has changed. That is, when the source ES determines that the user plane path of the UE's PDU session has changed, the source ES sends this second notification message to the source AS. Optionally, the second notification message may include the first information.

[0297] Understandably, the second notification message in step S1007 is a response to the user plane management event notification subscribed by the source AS to the source ES in step S1001.

[0298] S1008, the source AS receives the second notification message.

[0299] S1009. The source AS determines the target AS based on the first information.

[0300] For example, when the second notification message includes the first information, the source AS can determine the target AS based on the first information included in the second notification message. Optionally, when the second notification message does not include the first information, after receiving the second notification message, the source AS can send a request to the 5GC network element to obtain the first information, and determine the target AS based on the first information obtained from the 5GC network element.

[0301] Optionally, when the first information included in the second notification message is the UE's IP address, the source AS, upon receiving the second notification message, can query the 5GC network element for the path information of the UE's IP address and determine the target AS based on the path information. For example, the source AS can establish an AF policy association based on the IP address, and query the path information of the session (e.g., the DNAI corresponding to the session) or the UE's location information through the AF policy association, and determine the target AS based on the DNAI or the UE's location information.

[0302] Understandably, in step S1009 above, the source AS determines the specific implementation method of the target AS based on the first information. This can be referred to in step S602, where the source AF determines the implementation method of the target AS based on the first information. It will not be repeated here.

[0303] S1010, Source AS triggers application migration.

[0304] Optionally, in step S1010, the application migration can also be triggered by the source ES. When step S1010 is triggered by the source ES, before step S1010, the source AS may send the connection information of the target AS to the source ES, so that the source ES can migrate the UE's context from the source AS to the target AS based on the connection information of the target AS.

[0305] Understandable. Figure 10 Step S1010 is an optional step.

[0306] S1011. The source AS sends the connection information of the target AS to the UE.

[0307] The connection information for the target AS includes the address information of the target AS. This connection information can be the IP address of the target AS, the URI of the target AS, the URL of the target AS, or the endpoint of the target AS, etc.

[0308] For example, the source AS can send the connection information of the target AS to the AC in the UE.

[0309] S1012. The UE receives the connection information of the target AS and establishes a connection with the target AS.

[0310] Understandably, the specific implementation of steps S1011-S1012 can be found in steps S706-S707, and will not be repeated here.

[0311] It should be noted that this application does not impose any restrictions on the order in which steps S1001-S1012 are performed. Figure 10 This is merely an illustrative example.

[0312] As is understood, the application migration method provided in this application subscribes to session reconstruction event notifications from the EEC in the UE to the OS in the UE. This allows the OS in the UE to notify the EEC in the UE when the UE's PDU session is reconstructed. The EEC in the UE then notifies the source ES, and the source ES sends a notification to the source AS. The source AS can then determine the target AS based on the information included in the notification sent by the source ES and trigger application migration. This method accurately determines the target AS based on the UE's location information after the user plane path of the UE's PDU session changes, resulting in lower latency when the UE accesses the target AS. Furthermore, since the method triggers the reselection of the target AS and application migration from the source AS, it does not modify the AC in the UE. Therefore, it does not require the AC to understand network logic, simplifying AC design.

[0313] The flowchart of the application migration method provided in this application embodiment is shown below. Figure 11 As shown, the interaction between the source ES, the EEC in the UE, the OS in the UE, and the AC in the UE includes the following steps:

[0314] S1101, The EEC in the UE subscribes to the OS in the UE for a session reconstruction event notification.

[0315] S1102, The OS in the UE sends a sixth notification message to the EEC in the UE.

[0316] S1103, the EEC in the UE receives the sixth notification message.

[0317] S1104, The EEC in the UE sends a fourth notification message to the source ES.

[0318] S1105, the source ES receives the fourth notification message.

[0319] Understandably, the specific implementation methods of the above steps S1101-S1105 can refer to the implementation methods of steps S1002-S1006, and will not be repeated here.

[0320] S1106. The source ES determines the target AS based on the first information.

[0321] For example, when the fourth notification message includes the first information, the source ES can determine the target AS based on the first information included in the fourth notification message. Optionally, when the fourth notification message does not include the first information, after receiving the fourth notification message, the source ES can send a request to the 5GC network element to obtain the first information, and determine the target AS based on the first information obtained from the 5GC network element.

[0322] Understandably, in step S1106 above, the source ES determines the specific implementation method of the target AS based on the first information. This can be referred to in step S602, where the source AF determines the implementation method of the target AS based on the first information. It will not be repeated here.

[0323] S1107, Source ES triggers application migration.

[0324] Optionally, in step S1107, the application migration can also be triggered by the source AS. When step S1107 is triggered by the source AS, before step S1107, the source ES can send the connection information of the target AS to the source AS, so that the source AS can migrate the UE's context from the source AS to the target AS based on the connection information of the target AS.

[0325] Understandable. Figure 11 Step S1107 is an optional step.

[0326] S1108, The source ES sends the connection information of the target AS to the UE.

[0327] For example, the source ES can send the connection information of the target AS to the AC in the UE.

[0328] S1109. The UE receives the connection information of the target AS and establishes a connection with the target AS.

[0329] It should be noted that this application does not impose any restrictions on the order in which steps S1101-S1109 are performed. Figure 11 This is merely an illustrative example.

[0330] The application migration method provided in this application embodiment subscribes to session reconstruction event notifications from the EEC in the UE to the OS in the UE. This allows the OS in the UE to notify the EEC in the UE when the UE's PDU session is reconstructed, and the EEC in the UE to notify the source ES. The source ES then determines the target AS and triggers application migration. This method accurately determines the target AS based on the UE's location information after the user plane path of the UE's PDU session changes, resulting in lower latency when the UE accesses the target AS. Furthermore, since the method triggers the target AS reselection and application migration from the source ES, it does not modify the AC in the UE. Therefore, it does not require the AC to understand network logic, simplifying AC design.

[0331] The flowchart of the application migration method provided in this application embodiment is shown below. Figure 12 As shown, the interaction between the source AS, target ES, EEC in the UE, OS in the UE, and AC in the UE includes the following steps:

[0332] S1201, The EEC in the UE subscribes to the OS in the UE for a session reconstruction event notification.

[0333] S1202, the OS in the UE sends a sixth notification message to the EEC in the UE.

[0334] S1203, the EEC in the UE receives the sixth notification message.

[0335] For example, after receiving the sixth notification message, the EEC in the UE learns from the sixth notification message that the UE's PDU session has been rebuilt and determines that an application handover is required.

[0336] Understandably, the specific implementation methods of the above steps S1201-S1203 can refer to the implementation methods of steps S1002-S1004, and will not be repeated here.

[0337] S1204. The EEC in the UE determines the target ES based on the first information.

[0338] For example, when the sixth notification message includes the first information, the EEC in the UE can determine the target ES based on the first information in the sixth notification message.

[0339] In one implementation, the target ES and the source ES are the same ES. In another implementation, the target ES and the source ES are different ESs.

[0340] The target ES can be an ES deployed in a DN that the UE can access. Optionally, the UE can access one or more DNs.

[0341] S1205, the EEC in the UE sends a discovery request to the target ES.

[0342] The discovery request is used to request a list of Application Servers (AS) managed by the target Elasticsearch (ES). Optionally, this list of ASes can be a list of ASes of the same application as the source AS service. For example, if the source AS is Tencent Video's AS, the discovery request is used to request a list of Tencent Video's ASes managed by the target ES.

[0343] Optionally, the discovery request may include identification information of the source AS.

[0344] S1206, The target ES receives a discovery request.

[0345] S1207, The target ES sends the first message to the EEC in the UE.

[0346] The first message includes connection information for one or more ASs managed by the target ES. Optionally, these one or more ASs can be the same application served by the source AS. For example, the target ES sends connection information for all Tencent Video ASs it manages to the UE.

[0347] S1208, the EEC in the UE receives the first message and determines the target AS from one or more ASs managed by the target ES based on the first message.

[0348] For example, the EEC in the UE can select one AS as the target AS from one or more ASs managed by the target ES. In one implementation, the first message contains the priorities of one or more ASs, and the EEC selects the AS with the highest priority as the target AS.

[0349] S1209, The EEC in the UE sends the connection information of the target AS to the AC in the UE.

[0350] S1210, the AC in the UE receives the connection information of the target AS and establishes a connection with the target AS.

[0351] S1211, The AC in the UE sends the connection information of the target AS to the source AS.

[0352] Optionally, in step S1211, the AC in the UE can also send the connection information of the target AS to the source ES, so that the source ES can receive the connection information of the target AS and migrate the UE's context from the source AS to the target AS.

[0353] S1212, The source AS receives the connection information of the target AS and triggers application migration.

[0354] For example, after receiving the connection information of the target AS, the source AS can perform a state transition between the source AS and the target AS, or an application context transition.

[0355] Application migration refers to migrating the UE's context from the source AS to the target AS.

[0356] Optionally, when the AC in the UE sends the connection information of the target AS to the source ES in step S1211, the source ES can receive the connection information of the target AS in step S1212 and trigger application migration. That is, in this embodiment, the application migration can be triggered by either the source AS or the source ES.

[0357] Understandably, steps S1011-S1212 above are optional. To improve the latency of UE accessing applications, the source AS or source ES can perform context synchronization between the source AS and the target AS.

[0358] It should be noted that this application does not impose any restrictions on the order in which steps S1201-S1212 are performed. Figure 12 This is merely an illustrative example.

[0359] As is understood, the application migration method provided in this application subscribes to session reconstruction event notifications from the EEC in the UE to the OS in the UE. This allows the OS in the UE to notify the EEC in the UE when the UE's PDU session is reconstructed. The EEC in the UE then determines the target AS and sends the connection information of the target AS to the source ES or source AS. The source ES or source AS then triggers application migration. This method accurately determines the target AS based on the UE's location information after the user plane path of the UE's PDU session changes, resulting in lower latency when the UE accesses the target AS. Furthermore, since the method triggers the reselection of the target AS and application migration from the source ES or source AS, it does not modify the AC in the UE. Therefore, it does not require the AC to understand network logic, simplifying AC design.

[0360] For example, consider the source ES subscribing to user plane management event notifications from the PCF / SMF entity. When a UE accesses a source AS deployed in the source DN (e.g., a Tencent Video AS), if the UE moves and its PDU session is rebuilt, the source ES can learn from the PCF / SMF entity that the user plane path of the UE's PDU session has changed. However, since the source ES does not know which AS in the source DN the UE is currently accessing, the source ES will send a notification message to all ASs deployed in the source DN to indicate that the user plane path of the UE's PDU session has changed. However, the UE may only access the Tencent Video AS in the source DN; therefore, notification messages sent by the source ES to other ASs (AS deployed in the source DN that the UE has not accessed) are invalid. Moreover, if the UE moves and no Tencent Video AS is deployed in the accessible DN, then the notification message sent by the source ES to the source AS is invalid. Therefore, in order to reduce invalid notifications during application migration, this application embodiment also provides an application migration method. This method sends a subscription request from the source AS to the source ES, so that when the source ES determines that a target AS exists, it sends a notification message including the connection information of the target AS to the source AS, thereby reducing invalid notifications during application migration.

[0361] The flowchart of the application migration method provided in this application embodiment is shown below. Figure 13 As shown, the interaction between the source AS, source ES, PCF entity / SMF entity, target AS, and UE includes the following steps:

[0362] S1301, Source AS sends a subscription request to Source ES.

[0363] This subscription request is used to notify the source AS when the source ES determines that a target AS exists. Optionally, the subscription request can also be used to notify the source AS when the source ES determines that a target AS exists in the DNs accessible to the UE. In one implementation, the subscription request can be an application handover event notification, and the name of the subscription request is not limited.

[0364] Optionally, the subscription request may include application identification information. This application identification information can be the identification information corresponding to the application, such as the application ID, or it can be the identification information of the server corresponding to the application, such as EASID (edge ​​application server ID).

[0365] For example, the target AS and the source AS serve the same application. That is, the application identifier (edgeapplication server ID, EAS ID) of the target AS and the source AS are the same.

[0366] Optionally, the source ES obtains available or accessible ASs from the target ES or CS, and determines that the target AS exists in the DNs accessible to the UE. This can be used to switch the application server accessed by the UE from the source AS to the target AS, thereby improving the user experience, such as lower latency and higher bandwidth.

[0367] Optionally, when the UE establishes a connection with the source AS or after establishing a connection with the source AS, the source AS may send a subscription request to the source ES.

[0368] For example, the DN that the UE can access can be one or more data networks that the UE can access at its new location. It is understood that after the UE moves, the data networks that it can access may not have an AS that provides the same application as the source AS. Therefore, by sending a subscription request, the source ES can notify the source AS when it determines that there is an AS that provides the same application as the source AS in the data networks that the UE can access, and then initiate application migration.

[0369] In one implementation, a DN has a specific service range or service area. When a UE enters this specific service range or service area, the DN can be considered an accessible DN for the UE; otherwise, it can be considered not an accessible DN for the UE at its current location. It should be understood that a UE can have zero, one, or more accessible DNs at its current location. In other words, the aforementioned subscription request can be used to notify the source AS when the source ES determines that a target AS can serve a UE at its current location, indicating that the target AS and the source AS serve the same application. For example, an AS has a specific service range or service area. When a UE is within this specific service range or service area, it can be considered that the AS can serve the UE at its current location; otherwise, it can be considered that the AS cannot serve the UE at its current location. It should be understood that the source ES determining that a target AS exists among the DNs accessible to the UE and determining that a target AS can serve the UE at its current location have the same meaning. The following explanation only uses the example of the source ES determining that a target AS exists among the DNs accessible to the UE.

[0370] Optionally, step S1301 can also involve the source AS sending indication information to the source ES indicating whether the source AS supports application handover, or indicating whether the application corresponding to the source AS supports handover. It is understood that when the source AS sends indication information to the source ES indicating that it supports application handover, the source ES can directly determine to perform application migration or determine to execute application migration when it determines that a target AS exists in the DNs accessible to the UE. It should be noted that the application migration in this embodiment can also be called application handover, which means switching the UE's context from the source AS to the target AS.

[0371] Optionally, the subscription request may also include information about the UE's PDU session. This PDU session information may include at least one of the UE's network protocol IP address, data network name (DNN), or single network slice selection assistance information (S-NSSAI). Optionally, the source ES may determine the Policy Control Function (PCF) entity or the Session Management Function (SMF) entity based on the UE's PDU session information included in the subscription request.

[0372] Optionally, the subscription request includes application identification information. The source ES can determine the target AS based on the application identification information, and notify the source AS when the source ES determines that a target AS exists that can serve the UE at the current location. In another implementation, the source ES can determine the application identification information corresponding to the source AS based on the received subscription request from the source AS.

[0373] S1302. The source ES subscribes to user plane management event notifications from the PCF entity or SMF entity. These user plane management event notifications are used to notify the source ES when the user plane path of the UE's PDU session changes. Optionally, the change in the user plane path of the UE's PDU session includes the reconstruction of the UE's PDU session. Alternatively, the source ES subscribes to UE mobility event or location change event notifications from the AMF entity. These mobility event or location change event notifications are used to notify the source ES when the UE's location changes. Optionally, the granularity of the location change may include UE cell change, RAN change, TA change, RA change, etc., and this application does not limit this.

[0374] It is understandable that the source ES may subscribe to notifications from the PCF, SMF, or AMF entities directly, or it may subscribe through other entities, such as NEF. This application does not limit this.

[0375] Optionally, in this embodiment, the SSC mode of the UE's PDU session can be SSC mode1, SSC mode2, or SSC mode3.

[0376] S1303, the PCF entity or SMF entity sends a third notification message to the source ES.

[0377] Understandably, the third notification message in step S1303 is a response to the user plane management event notification subscribed by the source ES to the PCF entity or SMF entity in step S1302, or it may be a response to the location change event notification subscribed by the source ES to the AMF entity in step S1302. Optionally, the third notification message may include the first information. A description of the first information can be found in the foregoing embodiments and will not be repeated here.

[0378] Optionally, step S1303 can also be that the AMF entity sends a third notification message to the source ES.

[0379] Optionally, the third notification message can be an ealier notification sent by the SMF or PCF to indicate that the source ES 5GC is about to or wants to switch the user plane path of the UE session.

[0380] S1304, the source ES receives the third notification message.

[0381] S1304a, Source ES determines whether target AS exists.

[0382] Optionally, the source ES determines whether a target AS exists in the DNs accessible to the UE based on the first information, including: the source ES can request the CS or the target ES to determine whether a target AS exists in the DNs accessible to the UE. In one implementation, the source ES sends the first information and application identification information to the CS. The CS determines the target ES based on the first information and application identification information, and the CS sends the target ES to the source ES. The source ES obtains from the target ES that one or more ASs exist in the DNs accessible to the UE, wherein the target ES is located in the DNs accessible to the UE. The target ES sends information about one or more ASs to the source ES. If the target ES manages multiple ASs, it can determine one and send it to the source ES, or it can send information about multiple ASs to the source ES, and the source ES determines the target AS. In another implementation, the source ES sends the first information and application identification information to the CS. The CS determines that one or more ASs exist in the DNs accessible to the UE based on the first information and application identification information, and the CS sends information about one or more ASs to the source ES, and the source ES determines the target AS. In another implementation, the source ES sends the first information and application identification information to the target ES. The target ES determines, based on the first information and application identification information, that one or more ASs exist in the DN corresponding to the target ES. The target ES then sends the information of the one or more ASs to the source ES, which then identifies the target AS. If the source ES obtains the target AS from the target ES or CS, the source ES determines that an accessible target AS exists; otherwise, the source ES determines that no accessible target AS exists. It is understandable that if both the source AS and the target ES are managed by the source ES, the source ES and target ES may be the same ES, and the interaction between the source ES and target ES can be skipped. The AS information can be the AS's connection information.

[0383] Optionally, determining whether a target AS exists may include: the source ES determining whether a target AS exists based on the first information and the application identifier information. In one implementation, the first information included in the third notification message is the DNAI corresponding to the user plane path of the UE's PDU session. If the source ES determines that an AS corresponding to the application identifier information exists in the DN corresponding to the DNAI, then the source ES determines that a target AS exists. Otherwise, if the source ES determines that an AS corresponding to the application identifier information does not exist in the DN corresponding to the DNAI, then the source ES can send the first information and the application identifier information to the CS or the target ES to determine the target AS, using the same method as described above, and will not be repeated here.

[0384] Optionally, if the source ES determines that the target AS does not exist in the DN that the UE can access, that is, there is no AS with the same application as the source AS deployed in the DN that the UE can access, then the source ES will not send a notification message to the source AS or send a notification message that the target AS does not exist. The source AS will not trigger application migration, and the UE will continue to access the source AS.

[0385] Optionally, after receiving the third notification message, the source ES performs the step of determining whether the target AS exists in the DNs accessible to the UE. Alternatively, the source ES performs this step after detecting that the source AS is overloaded. In other cases, this step is not performed to save computing resources.

[0386] Optionally, if the source ES determines that the target AS exists in the DN that the UE can access, continue to execute steps S1305-S1314.

[0387] S1305, Source ES sends the seventh notification message to Source AS.

[0388] In one implementation, when the source ES determines that a target AS exists in the DNs accessible to the UE, the source ES sends a seventh notification message to the source AS. Optionally, the seventh notification message includes connection information of the target AS.

[0389] Optionally, when the source ES determines that there is no target AS among the DNs accessible to the UE, the source ES may send a notification message to the source AS indicating that there is no target AS among the DNs accessible to the UE. Alternatively, when the source ES determines that there is no target AS that can serve the UE at its current location, the source ES may send a notification message to the source AS indicating that there is no target AS that can serve the UE at its current location.

[0390] Optionally, if in S1301, the source AS sends an indication message to the source ES, the indication message is used to indicate that the source AS supports application switching. If the source ES determines that there is an accessible target AS, the source ES can directly determine that application migration is required, or in other words, the source ES determines to perform application migration. Subsequent steps where the source AS determines that application migration is required can be skipped.

[0391] In another implementation, if the source ES directly determines that application migration is required, the source ES sends a seventh notification message to the source AS. The seventh notification message instructs the source AS to send the UE's context to the source ES.

[0392] AS.

[0393] Understandably, the seventh notification message in step S1305 is a response to the subscription request sent by the source AS to the source ES in step S1301. When the source ES determines that a target AS exists in the DNs accessible to the UE, the source ES sends the seventh notification message to the source AS.

[0394] S1306, Source AS receives the seventh notification message.

[0395] S1307, The source AS determines to migrate the context of the user equipment (UE) from the source AS to the target AS.

[0396] Step S1307 can also be that the source AS determines that application migration is needed, or that the source AS determines to perform application migration. This application migration refers to migrating the UE's context from the source AS to the target AS. Alternatively, this application migration refers to application context migration, that is, migrating the context on the source AS to the target AS. Here, the UE's context can also be called application context, and the name of the context is not limited. In one implementation, the source AS sends the UE's context to the target AS. In another implementation, the source AS sends the UE's context to the source ES, and subsequently the source ES sends it to the target AS. The source ES may need to pass through the target ES before being sent to the target AS.

[0397] Optionally, the source AS may also send a fourth indication message to the source ES, which instructs the source ES to migrate the context of the UE from the source AS to the target AS.

[0398] In one implementation, the source AS receives a seventh notification message, which includes connection information for the target AS, and the source AS determines that application migration is necessary. In another implementation, the source AS can determine whether application migration is needed based on different scenarios; that is, the source AS can determine that application migration is necessary or not. For example, the source AS might determine that application migration is not suitable at present based on factors such as load and the urgency of the business; this application does not limit this.

[0399] In one implementation, if the source Elasticsearch determines that application migration is required, the source Activated Service (AS) will execute the application migration upon receiving the request.

[0400] For example, after receiving the first notification message, the source AS can directly determine to trigger application migration. That is, if a target AS exists in the DNs accessible to the UE, the source AS directly determines to trigger application migration.

[0401] Optionally, steps S1308-S1311 may be included before step S1307 above, in which the source AS can negotiate with the target AS to determine whether application migration can be performed at present.

[0402] Optionally, in S1308, the source AS sends an application switching request message to the target AS.

[0403] The application switch request message is used to migrate the context on the source AS to the target AS.

[0404] Optionally, the first request message can also be used to request the target AS to allocate the resources required for application switching.

[0405] Optionally, in S1309, the target AS receives an application switching request message.

[0406] Optionally, in S1310, the target AS sends an application switching response message to the source AS.

[0407] The application switching response message includes a third indication message, which is used to indicate whether the target AS agrees to or accepts the application switching.

[0408] For example, the target AS can determine whether to agree to or accept the application switching request based on its resource usage. If the target AS has sufficient remaining resources, it will agree to accept the application switching. This third instruction information can instruct the target AS to agree to the application switching.

[0409] Optionally, S1311, the source AS receives the application switching response message.

[0410] In step S1307 above, the source AS determining to migrate the context of the user equipment UE from the source AS to the target AS may include: the source AS determining to migrate the context of the user equipment UE from the source AS to the target AS based on third indication information. If the third indication information in the application handover response message indicates that the target AS agrees to the application handover, the source AS determines to trigger the application migration.

[0411] Optionally, the source AS sends a fifth indication message to the source ES. This fifth indication message indicates whether the source AS supports application handover, agrees to application handover, or performs application handover. It is understood that this fifth indication message is a response to the seventh notification message. That is, after the source ES sends a seventh notification message to the source AS indicating that a target AS exists in the DNs accessible to the UE, the source AS sends the fifth indication message to the source ES indicating whether the source AS supports application handover.

[0412] Optionally, after receiving the fifth indication message, the source ES sends a sixth indication message to the 5GC (such as SMF, PCF, or AMF). This sixth indication message indicates whether the source AS supports application handover. Understandably, this sixth indication message is a response to the third notification message. The 5GC can determine whether to terminate the user plane path of the handover session based on this sixth indication message. For example, if the sixth indication message indicates that the source AS does not support application handover, the SMF will terminate the user plane path of the handover UE's PDU session after receiving the sixth indication message from the source ES.

[0413] Optionally, the source AS can also send a seventh indication message to the source ES, which indicates that service continuity needs to be maintained during application handover. This seventh indication message is used to establish a forwarding tunnel between UPFs when the DNAI changes, for service continuity purposes, so that the UE can send application data to the source AS.

[0414] Optionally, after receiving the seventh indication information, the source ES sends an eighth indication information to the SMF or PCF. This eighth indication information is used to indicate that service continuity needs to be maintained during application handover. Thus, after the source ES completes the handover, by sending this eighth indication information to the 5GC network element, the 5GC network element can release the forwarding tunnel.

[0415] S1312, Source AS triggers application migration.

[0416] Understandable. Figure 13 Step S1312 is an optional step.

[0417] In one implementation, when the source AS receives connection information from the target AS, the source AS triggers application migration.

[0418] In one implementation, the source AS sends the application context directly to the target AS.

[0419] In another implementation, the source AS sends the application context to the source ES, the source ES sends the context to the target ES, and then the target ES sends it to the target AS.

[0420] S1313, Optional, the source AS sends connection information of the target AS to the UE.

[0421] Optionally, step S1313 can also involve the source ES sending connection information of the target AS to the UE, or the source ES sending connection information of the target AS to the 5GC network element (e.g., SMF or PCF), and then the 5GC network element sending connection information of the target AS to the UE.

[0422] S1314, Optionally, the UE receives connection information from the target AS and establishes a connection with the target AS.

[0423] Optionally, the connection information of the target AS that the UE can receive can come from the source AS, source ES, 5GC network element or other devices, and this application embodiment does not limit this.

[0424] It should be noted that this application does not impose any restrictions on the order in which steps S1301-S1314 are performed. Figure 13 This is merely an illustrative example.

[0425] Understandably, the application migration method provided in this embodiment sends a subscription request from the source AS to the source ES. This allows the source ES to send a notification message containing connection information of the target AS to the source AS only after determining the existence of the target AS, and then the source AS triggers the application migration. Since the user plane path of the UE's PDU session may change, the data network accessible to the UE may not necessarily have an AS serving the same application as the source AS deployed. Therefore, by sending a subscription request, the source ES can notify the source AS only after determining that an AS serving the same application exists in the data network accessible to the UE, thus initiating the application migration. This reduces invalid notifications during the application migration process and lowers latency.

[0426] Optionally, embodiments of this application also provide an application migration method, which may include: a source AS sending indication information to a source ES indicating whether the source AS supports application handover, and the source ES receiving the indication information. The source ES subscribes to user plane management event notifications or mobility event notifications from the 5GC network element. When the user plane path of the UE's PDU session changes or the UE's location changes, the 5GC network element sends a third notification message to the source ES. The source ES receives the third notification message and determines whether a target AS exists in the DNs accessible to the UE based on first information. If the indication information indicates that the source AS supports application handover, then after the source ES determines that a target AS exists in the DNs accessible to the UE, the source ES determines to perform application migration. The source ES may request the context on the source AS from the source AS and migrate the context on the source AS to the target AS.

[0427] For example, during UE mobility, the data network serving the UE may change. The CS can update the data network information sent to the UE. Therefore, this application embodiment also provides an application migration method, which involves how to update network information during application migration. The flowchart of the method is shown below. Figure 14 As shown, the interaction between the CS, UE, and PCF / SMF entities involves the following steps:

[0428] S1401, UE sends first indication information to CS.

[0429] The first indication information is used to instruct the CS to send the target DN information to the UE when the user plane path of the UE's PDU session changes.

[0430] Optionally, in this embodiment, the change of the user plane path of the UE's PDU session includes the reconstruction of the UE's PDU session. In this embodiment, the SSC mode of the UE's PDU session can be SSC mode3. When the UE's PDU session is reconstructed, the data network accessed by the UE can be switched accordingly.

[0431] Optionally, in this embodiment, CS can be Figure 2 In the ECS, DN can be Figure 2 EDN in the context.

[0432] S1402, CS receives the first instruction information.

[0433] S1403, CS subscribes to user plane management event notifications from the PCF entity or SMF entity.

[0434] This user plane management event notification is used to notify the CS when the user plane path of the UE's PDU session changes.

[0435] S1404, the PCF entity or the SMF entity sends the fifth notification message to the CS.

[0436] The fifth notification message is used to notify the CS that the user plane path of the UE's PDU session has changed. That is, when the PCF entity or SMF entity determines that the user plane path of the UE's PDU session has changed, the PCF entity or SMF entity sends this fifth notification message to the CS. Optionally, the fifth notification message may include first information. A description of the first information can be found in the foregoing embodiments and will not be repeated here.

[0437] Understandably, the fifth notification message in step S1404 is a response to the user plane management event notification subscribed by CS to the PCF entity or SMF entity in step S1403.

[0438] S1405, CS receives the fifth notification message.

[0439] S1406 and CS determine the target DN based on the first information.

[0440] For example, the CS can determine the target DN based on the first information included in the fifth notification message. For instance, the first information is the UE's DNAI.

[0441] Optionally, the CS may also query the PCF entity or SMF entity for UPF information based on the first information included in the fifth notification message, and determine the target DN based on the UPF information. For example, the CS may query the DNAI from the PCF entity or SMF entity based on the UE's IP address included in the fifth notification message, and determine the target DN based on the DNAI.

[0442] S1407, CS sends the target DN information to UE.

[0443] S1408, The UE receives information from the target DN and establishes a connection with the target DN.

[0444] It should be noted that this application does not impose any restrictions on the order in which steps S1401-S1408 are performed. Figure 14 This is merely an illustrative example.

[0445] In this embodiment, the UE instructs the CS to send the target DN information to the UE when the UE's PDU session is re-established. This enables the CS to send the target DN information to the UE when the UE's PDU session is re-established, so that the UE can access the target DN.

[0446] For example, this application also provides a method for application migration, which involves how to update network information during the application migration process. A flowchart of the method is shown below. Figure 15 As shown, the interaction between the CS and UE involves the following steps:

[0447] S1501, UE sends the first indication information to CS.

[0448] The first indication information is used to instruct the CS to send the target DN information to the UE when the user plane path of the UE's PDU session changes.

[0449] Optionally, in this embodiment, the change of the user plane path of the UE's PDU session includes the reconstruction of the UE's PDU session. When the UE's PDU session is reconstructed, the data network accessed by the UE can be switched accordingly.

[0450] Optionally, in this embodiment, CS can be Figure 2 In the ECS, DN can be Figure 2 EDN in the context.

[0451] Optionally, in this embodiment, the SSC mode of the UE's PDU session can be SSC mode3.

[0452] S1502, CS receives the first instruction information.

[0453] S1503, UE sends a second instruction message to CS.

[0454] The second indication information is used to indicate that the UE's PDU session has been rebuilt. Optionally, the second indication information includes the first information.

[0455] S1504, CS receives the second instruction information.

[0456] S1505 and CS determine the target DN based on the first information.

[0457] For example, the CS can determine the target DN based on the first information included in the second indication information. For example, the first information is the UE's DNAI.

[0458] Optionally, when the second indication information does not include the first information or the first information included in the second indication information is the UE's IP address, after receiving the second indication information, the CS can query the DNAI from the PCF entity or SMF entity and determine the target DN based on the DNAI.

[0459] S1506, CS sends the target DN information to UE.

[0460] S1507. The UE receives information from the target DN and establishes a connection with the target DN.

[0461] It should be noted that this application does not impose any restrictions on the order in which steps S1501-S1507 are performed. Figure 15 This is merely an illustrative example.

[0462] Understandable. Figure 14 The illustrated embodiments and Figure 15 The difference in the illustrated embodiments is that, Figure 14 The illustrated embodiment learns that the UE's PDU session has been rebuilt by the CS subscribing to user plane management event notifications from the PCF or SMF entity. Figure 15 The illustrated embodiment shows that after the UE rebuilds the session, it sends an indication message to the CS to inform the CS that the UE's PDU session has been rebuilt. In other words, Figure 14 The illustrated embodiments and Figure 15 The difference between the embodiments shown is that the CS learns of the UE's PDU session and re-establishes it.

[0463] In this embodiment, the UE instructs the CS to send the target DN information to the UE when the UE's PDU session is re-established, and notifies the CS when the UE's PDU session is re-established. Thus, the CS can determine the target DN and send the target DN information to the UE so that the UE can access the target DN.

[0464] The flowchart of the application migration method provided in this application embodiment is shown below. Figure 16 As shown, the interaction between the target ES, CS, 5GC network elements (such as SMF, UPF or other entities capable of assigning IPs) and UE (which may include AC, EEC, OS, etc.) includes the following steps:

[0465] The S1601 and 5GC network elements send the first information to the UE.

[0466] For example, the 5GC network element can be an SMF entity, a UPF entity, or other network elements that can be assigned IP addresses.

[0467] In one implementation, the SSC mode of the session established by the UE is mode 3. When the UE re-establishes a new session or creates a multi-homed session, the UE obtains a new IP address from the 5GC network element. This new IP address can be the IP address after the UE re-establishes the PDU session or the UE's IP address corresponding to the newly inserted anchor UPF when using the multi-homed session creation mechanism to implement SSC mode 3. This new IP address may be assigned by the SMF entity, the UPF entity, the DN-AAA entity, or other entities; this application does not limit this. Optionally, the 5GC network element (such as the SMF network element) can also send the DNAI corresponding to the anchor UPF of the new session or the newly inserted anchor UPF of the multi-homed session to the UE.

[0468] It is understood that a detailed description of the first information can be found in the foregoing embodiments, and will not be repeated here.

[0469] S1602, UE receives the first information.

[0470] For example, step S1602 may involve the EEC module, AC module, or OS in the UE receiving the first information, and this application does not limit this.

[0471] S1603, UE sends the first message to CS.

[0472] For example, this first information can be included in the Service provisioning request.

[0473] Optionally, in one implementation, the EEC module in the UE can send the first information to the CS.

[0474] S1604 and CS receive the first information.

[0475] S1605 and CS determine the target ES based on the first information.

[0476] In the first implementation, the UE sends a new IP address to the CS. If the CS is configured with a mapping relationship between IP address (segment) and target ES or DN, the CS can determine the target ES, where the target ES serves the target DN.

[0477] In the second implementation, the UE sends a new IP address to the CS. The CS can then send a request to the 5GC network element containing the new IP address. This request is used to obtain the anchor point UPF for the new session of the UE or the DNAI corresponding to the newly inserted anchor point UPF for a multi-homed session based on the UE's IP address. If the CS has configured a mapping relationship between the DNAI and the target ES or DN, the CS can determine the target ES.

[0478] In the third implementation, the UE sends the anchor point UPF of the new session or the DNAI corresponding to the newly inserted anchor point UPF of the multi-homed session to the CS. If the CS has configured the mapping relationship between the DNAI and the target ES or DN, the CS can determine the target ES. Compared with the second implementation, the process of querying the DNAI from the 5GC network element can be eliminated.

[0479] S1606, CS sends connection information of target ES to UE.

[0480] Optionally, in step S1605, the CS may also send connection information of the target ES to the UE. The connection information of the target ES includes the address information of the target ES, which may be the IP address, URI, URL, endpoint, etc. of the target ES.

[0481] S1607, The UE receives the connection information of the target ES.

[0482] Optionally, in step S1606, the connection information of the target ES can be received by the EEC module in the UE.

[0483] S1608, the UE sends a second application discovery request to the target ES.

[0484] The second application discovery request is used to request the acquisition of the target AS.

[0485] In one implementation, the UE's EEC module sends a second application discovery request to the target ES. Optionally, the second application discovery request includes a new IP address.

[0486] Optionally, the second application discovery request may include the application identifier of the source AS.

[0487] Optionally, the second application discovery request may include the first information.

[0488] S1609, The target ES receives the second application discovery request.

[0489] S1610, Target ES determines Target AS.

[0490] Optionally, the target ES can determine the target AS based on the first information. For details on how the target ES determines the target AS based on the first information, please refer to the process for determining the target AS in S602; it will not be elaborated here. It is understood that the target AS determined by the target ES based on the first information has the same application identifier as the source AS.

[0491] S1611, Optional, the target ES determines to trigger application migration.

[0492] In one implementation, the target ES determines that an application migration is needed based on receiving a new IP address and a second application discovery request. The target ES can then send the connection information of the target AS to the source ES or the source AS.

[0493] Optionally, if the target ES determines that it is triggering application migration, the target ES may send the connection information of the target AS to the UE.

[0494] S1612, The target ES sends the connection information of the target AS to the UE.

[0495] Optionally, the target ES can also send connection information of the target AS to the UE. This connection information of the target AS includes the address information of the target AS, which can be IP address, URI, URL, endpoint, etc.

[0496] S1613, The UE receives the connection information of the target AS.

[0497] In one implementation, the UE's EEC module receives connection information from the target AS.

[0498] S1614, Optional, the UE determines to trigger application migration.

[0499] In one implementation, the UE's EEC module determines that application migration is required after receiving the connection information of the target AS.

[0500] In one implementation, the source AS sends the application context directly to the target AS.

[0501] In another implementation, the source AS sends the application context to the source ES, the source ES sends the context to the target ES, and then the target ES sends it to the target AS.

[0502] It is understood that the application migration can be triggered by the target ES, the UE, or other network devices, and the application migration is not limited in this respect.

[0503] It should be noted that this application does not impose any limitation on the order in which steps S1601-S1614 are performed. Figure 16 This is merely an illustrative example.

[0504] Understandably, the application migration method provided in this application embodiment, for SSC mode 3 sessions, involves the UE receiving first information from the 5GC network element during PDU session reconstruction. The UE sends this first information to the CS, which determines the target ES based on the first information. The UE can then obtain target AS connection information from the target ES. This method accurately determines the target ES based on the UE's location information after the user plane path of the UE's PDU session changes, resulting in a more accurate target AS. Therefore, the latency when the UE accesses the target AS is lower. Furthermore, this method triggers the reselection of the target AS and application migration via the target ES or EEC, without modifying the AC in the UE. Therefore, it does not require the AC to understand network logic, simplifying AC design.

[0505] The flowchart of the application migration method provided in this application embodiment is shown below. Figure 17 As shown, the interaction between the source ES, target ES, CS, 5GC network elements (such as SMF, UPF or other entities capable of assigning IPs) and UE (which may include AC, EEC, OS, etc.) includes the following steps:

[0506] The S1701 and 5GC network elements send the first information to the UE.

[0507] It is understood that a detailed description of the first information can be found in the foregoing embodiments, and will not be repeated here.

[0508] S1702, UE receives the first information.

[0509] For example, step S1702 may involve the EEC module, AC module, or OS in the UE receiving the first information, and this application does not limit this.

[0510] Understandably, the specific implementation methods of the above steps S1701-S1702 can refer to the implementation methods of steps S1601-S1602, and will not be repeated here.

[0511] S1703, UE sends the first information to the source ES.

[0512] Optionally, in one implementation, the EEC module in the UE can send the first information to the source ES.

[0513] Optionally, the first information may be included in a request message, which may be a discovery request message for the application server.

[0514] S1704, the source ES receives the first information.

[0515] S1705, Source ES sends the first message to CS.

[0516] Optionally, the first information sent by the source ES to the CS may be included in a request message used to obtain the target ES from the CS.

[0517] S1706, CS receives the first information.

[0518] S1707 and CS determine the target ES based on the first information.

[0519] Understandably, the specific implementation of CS determining the target ES based on the first information in step S1707 can refer to the implementation of step S1605, and will not be repeated here.

[0520] S1708, CS sends the connection information of the target ES to the source ES.

[0521] S1709, The source ES receives the connection information of the target ES.

[0522] S1710, the source ES sends the first application discovery request to the target ES.

[0523] The first application discovery request is used to request the target AS.

[0524] Optionally, the first application discovery request includes first information. This first application discovery request is used to obtain the target AS from the target ES.

[0525] Optionally, the first application discovery request may include the application identifier of the source AS.

[0526] S1711, The target ES receives the first application discovery request.

[0527] S1712, Target ES determines Target AS.

[0528] Optionally, the target ES can determine the target AS based on the first information. For example, the target ES can be determined based on the first information and the application identification information. For details on how the target ES determines the target AS based on the first information, please refer to the process of determining the target AS in S602, which will not be elaborated here.

[0529] Optionally, the target ES can also be determined solely based on application identification information. This application identification information is the identification information of the application corresponding to the source AS.

[0530] S1713, The target ES sends the connection information of the target AS to the source ES.

[0531] Optionally, the target ES can also directly send the target AS connection information to the UE, or the target ES can also send the target AS connection information to the CS, and the CS will then send the target AS connection information to the UE.

[0532] S1714. The source ES receives the connection information of the target AS.

[0533] S1715, The source ES sends the connection information of the target AS to the UE.

[0534] S1716, The UE receives the connection information of the target AS.

[0535] In one implementation, the UE's EEC module receives connection information from the target AS.

[0536] S1717, Optional, if the target Elasticsearch instance is determined to require application migration.

[0537] In one implementation, the target ES determines that an application migration is needed based on the new IP address and the first application discovery request received. Then, the target ES sends the connection information of the target AS to the source ES or the source AS.

[0538] S1718. Optional, if the UE determines that application migration is required.

[0539] In one implementation, the UE's EEC module determines that application migration is required after receiving the connection information of the target AS.

[0540] In one implementation, the source AS sends the application context directly to the target AS.

[0541] In another implementation, the source AS sends the application context to the source ES, the source ES sends the context to the target ES, and then the target ES sends it to the target AS.

[0542] It should be noted that this application does not impose any restrictions on the order in which steps S1701-S1718 are performed. Figure 17 This is merely an illustrative example.

[0543] Understandably, the application migration method provided in this application embodiment, for SSC mode 3 sessions, involves the UE receiving first information from a 5GC network element during UE PDU session reconstruction. The UE sends the first information to the source ES, the source ES sends the first information to the CS, and the CS determines the target ES based on the first information. The source ES can then obtain the connection information of the target AS from the target ES and send the connection information of the target AS to the UE. This method accurately determines the target ES based on the UE's location information after the user plane path of the UE's PDU session changes, and the target AS determined based on the target ES is also accurate. Therefore, the latency when the UE accesses the target AS is low. Moreover, this method triggers the reselection of the target AS and application migration by the target ES or EEC, without modifying the AC in the UE. Therefore, it does not require the AC to understand network logic, simplifying AC design.

[0544] The foregoing mainly describes the solutions provided by the embodiments of this application from the perspective of method steps. It is understood that, in order to implement the above functions, a computer includes corresponding hardware structures and / or software modules for executing each function. Those skilled in the art should readily recognize that, in conjunction with the units and algorithm steps of the various examples described in the embodiments disclosed herein, this application can be implemented in a combination of hardware and computer software. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0545] This application embodiment can divide the computer into functional modules according to the above method example. For example, each function can be divided into its own functional modules, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0546] Figure 18 A schematic diagram of a communication device 1800 is shown. The communication device can be the aforementioned source AS or a chip within the aforementioned source AS. The communication device 1800 can be used to implement the methods and functions of the source AS involved in any of the above embodiments.

[0547] The communication device 1800 includes a processing unit 1801 and a transceiver unit 1802. For example, the transceiver unit 1802 can be used to support communication between the source AS and the source ES, PCF entity / SMF entity, or UE in the above embodiments. The processing unit 1801 is used to control and manage the actions of the source AS and to execute the processing performed by the source AS in the above embodiments. Optionally, if the communication device 1800 includes a storage unit, the processing unit 1801 can also execute programs or instructions stored in the memory to enable the communication device 1800 to implement the methods and functions involved in any of the above embodiments.

[0548] For example, the processing unit 1801 described above can be used to perform, for example... Figure 6 Steps S602-S603, or, Figure 7 Steps S704 and S705, or, Figure 9 Steps S907 and S908 in the process, or, Figure 10 Steps S1009 and S1010 in the process, or, Figure 12 In step S1212, the application migration is triggered, or... Figure 13 Steps S1307 and S1312, and / or other processes used in the technology described herein. The transceiver unit 1802 can be used to perform, for example... Figure 6 Step S601, or, Figure 7 Steps S701, S703, and S706, or, Figure 9 Steps S901, S906, and S909 in the above, or, Figure 10 Steps S1001, S1008, and S1011, or, Figure 12 In step S1212, the connection information of the target AS is received, or... Figure 13 Steps S1301, S1306, S1308, S1311, and S1313, and / or other processes used in the technology described herein. All relevant content regarding each step in the above method embodiments can be referenced to the functional description of the corresponding functional module, and will not be repeated here.

[0549] For example, the communication device 1800 can be Figure 5 The communication device shown, the processing unit 1801 can be Figure 5 The processor 501 and transceiver unit 1802 in the middle can be Figure 5 The transceiver 503 is included. Optionally, the communication device 1800 may further include a memory for storing program code and data corresponding to the communication device 1800 executing any of the application migration methods provided above. Figure 5All descriptions of the relevant components can be found in the functional descriptions of the corresponding components of the communication device 1800, and will not be repeated here.

[0550] Figure 19 A schematic diagram of a communication device 1900 is shown. The communication device can be the aforementioned source ES, or it can be a chip within the aforementioned source ES. The communication device 1900 can be used to implement the methods and functions related to the source ES in any of the above embodiments.

[0551] The communication device 1900 includes a processing unit 1901 and a transceiver unit 1902. For example, the transceiver unit 1902 can be used to support communication between the source ES and the source AS, PCF entity / SMF entity, or UE in the above embodiments. The processing unit 1901 is used to control and manage the actions of the source ES and to execute the processing performed by the source ES in the above embodiments. Optionally, if the communication device 1900 includes a storage unit, the processing unit 1901 can also execute programs or instructions stored in the memory to enable the communication device 1900 to implement the methods and functions involved in any of the above embodiments.

[0552] For example, the processing unit 1901 described above can be used to perform, for example... Figure 6 Step S602, or, Figure 8 Steps S804 and S805, or, Figure 11 Steps S1106 and S1107, and / or other processes used in the technology described herein. The transceiver unit 1902 can be used to perform, for example... Figure 6 Steps S601 and S603, or, Figure 8 Steps S801, S803, and S806, or, Figure 9 Steps S902, S904, and S905, or, Figure 10 Steps S1006 and S1007, or, Figure 11 Steps S1105 and S1108, or, Figure 13 Steps S1302, S1304, and S1305, or, Figure 17 Steps S1704, S1705, S1709, S1710, S1714, and S1715, and / or other processes used in the technology described herein. All relevant content regarding each step in the above method embodiments can be referenced to the functional description of the corresponding functional module, and will not be repeated here.

[0553] For example, the communication device 1900 can be Figure 5 The communication device shown, the processing unit 1901 can be Figure 5 The processor 501 and transceiver unit 1902 in the middle can be Figure 5 The transceiver 503 is included. Optionally, the communication device 1900 may further include a memory for storing program code and data corresponding to the communication device 1900 performing any of the application migration methods described above. Figure 5 All descriptions of the relevant components can be found in the functional descriptions of the corresponding components of the communication device 1900, and will not be repeated here.

[0554] Figure 20 A schematic diagram of a communication device 2000 is shown. The communication device can be the UE described above, or it can be a chip within the UE. The communication device 2000 can be used to implement the methods and functions of the UE involved in any of the above embodiments.

[0555] The communication device 2000 includes a processing unit 2001 and a transceiver unit 2002. For example, the transceiver unit 2002 can be used to support communication between the UE and the source ES, source AS, and target ES in the above embodiments. The processing unit 2001 is used to control and manage the actions of the UE and to execute the processes performed by the UE in the above embodiments. Optionally, if the communication device 2000 includes a storage unit, the processing unit 2001 can also execute programs or instructions stored in the memory to enable the communication device 2000 to implement the methods and functions involved in any of the above embodiments.

[0556] For example, the processing unit 2001 described above can be used to perform, for example... Figures 6 to 13 Establish a connection with the target AS, or execute... Figure 14 or Figure 15 Establish a connection with the target DN, or execute... Figure 12 In steps S1204 and S1208, the target AS is determined from one or more ASs managed by the target ES based on the first message, or... Figure 16 Step S1614, or, Figure 17 Step S1708 in the document, and / or other processes used in the technology described herein. The transceiver unit 2002 can be used to perform, for example, receiving connection information from the target AS, or... Figure 10 Step S1005, or, Figure 11 Step S1104, or, Figure 12 S1201-S1203, receiving the first message in steps S1205 and S1208, S1209 and S1211, or, Figure 14 In steps S1401 and S1408, the information of the target DN is received, or... Figure 15 In steps S1501, S1503, and S1507, the information of the target DN is received, or... Figure 16Steps S1602, S1603, S1607, S1608, and S1612, or... Figure 17 Steps S1702, S1703, and S1716, and / or other processes used in the technology described herein. All relevant content regarding each step in the above method embodiments can be referenced to the functional description of the corresponding functional module, and will not be repeated here.

[0557] For example, the communication device 2000 can be Figure 5 The communication device shown, the processing unit 2001 can be Figure 5 The processor 501 and transceiver unit 2002 in the middle can be Figure 5 The transceiver 503 is included. Optionally, the communication device 2000 may further include a memory for storing program code and data corresponding to the communication device 2000 executing any of the application migration methods provided above. Figure 5 All descriptions of the relevant components can be found in the functional descriptions of the corresponding components in the communication device 2000, and will not be repeated here.

[0558] Figure 21 A schematic diagram of a communication device 2100 is shown. The communication device can be the CS mentioned above, or it can be a chip within the CS. The communication device 2100 can be used to implement the methods and functions of the CS involved in any of the above embodiments.

[0559] The communication device 2100 includes a processing unit 2101 and a transceiver unit 2102. For example, the transceiver unit 2102 can be used to support communication between the CS and the PCF entity, SMF entity, or UE in the above embodiments. The processing unit 2101 is used to control and manage the actions of the CS and to execute the processing performed by the CS in the above embodiments. Optionally, if the communication device 2100 includes a storage unit, the processing unit 2101 can also execute programs or instructions stored in the memory to enable the communication device 2100 to implement the methods and functions involved in any of the above embodiments.

[0560] For example, the processing unit 2101 described above can be used to perform, for example... Figure 14 In step S1406, or, Figure 15 In step S1505, or, Figure 16 Step S1605, or, Figure 17 Step S1707 in the document, and / or other processes used in the technology described herein. The transceiver unit 2102 can be used to perform, for example... Figure 14 Steps S1402, S1403, S1405, and S1407, or... Figure 15Steps S1502, S1504, and S1506, or, Figure 16 Steps S1604 and S1606, or, Figure 17 Steps S1706 and S1708, and / or other processes used in the technology described herein. All relevant content regarding each step in the above method embodiments can be referenced to the functional description of the corresponding functional module, and will not be repeated here.

[0561] For example, the communication device 2100 can be Figure 5 The communication device shown, the processing unit 2101 can be Figure 5 The processor 501 and transceiver unit 2102 in the middle can be Figure 5 The transceiver 503 is included. Optionally, the communication device 2100 may further include a memory for storing program code and data corresponding to the communication device 2100 executing any of the application migration methods provided above. Figure 5 All descriptions of the relevant components can be found in the functional descriptions of the corresponding components of the communication device 2100, and will not be repeated here.

[0562] For example, embodiments of this application also provide an application migration apparatus, which includes a processor configured to execute computer execution instructions to support the implementation of the application migration apparatus. Figures 6 to 17 The application migration method in any of the embodiments is described. Optionally, the application migration apparatus may further include a transceiver and a memory; the transceiver is used for sending and receiving information or for communicating with other network elements; the memory is used for storing computer-executed instructions.

[0563] This application embodiment also provides a computer storage medium storing computer program code. When the processor executes the computer program code, the electronic device performs... Figures 6 to 17 The application migration method in any of the embodiments.

[0564] This application also provides a computer program product that, when run on a computer, causes the computer to perform... Figures 6 to 17 The application migration method in any of the embodiments.

[0565] This application embodiment also provides a communication system, which includes a source application server (AS), a source enable server (ES), and a user equipment (UE). The source AS subscribes to user plane management event notifications from the source ES. These user plane management event notifications are used to notify the source AS when the user plane path of the UE's Protocol Data Unit (PDU) session changes. The source AS is the AS accessed by the UE before the user plane path of the PDU session changes. The source ES obtains first information, which is the location information of the UE after the user plane path of the UE's PDU session changes. The source ES sends a second notification message to the source AS, which is used to notify the source AS that the user plane path of the UE's PDU session has changed. The second notification message includes the first information. Based on the first information, the source AS determines a target AS and triggers application migration, which refers to migrating the UE from the source AS to the target AS. The source AS sends connection information of the target AS to the UE. The UE receives the connection information of the target AS and establishes a connection with the target AS.

[0566] This application also provides a chip system, which includes a processor and a memory, wherein the memory stores instructions; when the instructions are executed by the processor, they implement the above-described... Figures 6 to 17 The application migration method in any of the embodiments.

[0567] The steps of the methods or algorithms described in this application can be implemented in hardware or by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in random access memory (RAM), flash memory, erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. Alternatively, the ASIC can reside in a core network interface device. Of course, the processor and storage medium can also exist as discrete components in the core network interface device.

[0568] Those skilled in the art will recognize that, in one or more of the examples above, the functions described in this application can be implemented using hardware, software, firmware, or any combination thereof. When implemented in software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any medium that facilitates the transfer of a computer program from one place to another. Storage media can be any available medium accessible to a general-purpose or special-purpose computer.

[0569] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above description is only a specific embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solution of this application should be included within the scope of protection of this application.

Claims

1. A method for application migration, characterized in that, The method includes: The source edge application server (EAS) sends a subscription request to the source edge enable server (EES). The subscription request is used to notify the source EAS when the source EES determines that a target EAS exists in the data network DN that the terminal device can access. The source EAS receives a seventh notification message from the source EES. The seventh notification message is used to indicate that a target EAS exists in the DN that the terminal device can access. The seventh notification message includes the address information of the target EAS. The source EAS determines to migrate the context of the terminal device from the source EAS to the target EAS.

2. The method according to claim 1, characterized in that, The method further includes: The source EAS sends a fourth indication message to the source EES, the fourth indication message being used to instruct the source EES to migrate the context of the terminal device from the source EAS to the target EAS.

3. The method according to claim 1 or 2, characterized in that, The target EAS and the source EAS serve the same application.

4. The method according to claim 1 or 2, characterized in that, The method further includes: The source EAS sends an application switching request message to the target EAS, the application switching request message being used to migrate the context on the source EAS to the target EAS.

5. The method according to claim 4, characterized in that, The method further includes: The source EAS receives an application switching response message from the target EAS. The application switching response message includes third indication information, which is used to indicate whether the target EAS agrees to the application switching. The source EAS determines to migrate the context of the terminal device from the source EAS to the target EAS, including: if the third indication information indicates that the target EAS agrees to the application switching, the source EAS determines to migrate the context of the terminal device from the source EAS to the target EAS.

6. The method according to claim 5, characterized in that, The source EAS determines to migrate the context of the terminal device from the source EAS to the target EAS, including: If the third indication information indicates that the target EAS agrees to the application handover, the source EAS determines to migrate the context of the terminal device from the source EAS to the target EAS.

7. The method according to any one of claims 1, 2, 5, and 6, characterized in that, The method further includes: The source EAS sends a fifth indication message to the source EES, which is used to indicate whether the source EAS supports application switching.

8. The method according to any one of claims 1, 2, 5, and 6, characterized in that, The method further includes: The source EAS sends a seventh indication message to the source EES, which is used to indicate that service continuity needs to be maintained when the application is switched.

9. A method for application migration, characterized in that, The method includes: The source edge enabling server (EES) receives a subscription request from the source edge application server (EAS). The subscription request is used to notify the source EAS when the source EES determines that a target EAS exists in the data network (DN) that the terminal device can access. The source EES acquires first information, which is the location information of the terminal device after the user plane path of the protocol data unit (PDU) session of the terminal device has changed; the location information of the terminal device includes the data network access identifier (DNAI) corresponding to the user plane path of the PDU session of the terminal device. Based on the first information, the source EES determines that the target EAS exists in the DN that the terminal device indicated by the DNAI can access; The source EES sends a seventh notification message to the source EAS. The seventh notification message is used to indicate that a target EAS exists in the DN that the terminal device can access. The seventh notification message includes the address information of the target EAS.

10. The method according to claim 9, characterized in that, The location information of the terminal device includes at least one of the following: the IP address of the terminal device, the data network access identifier (DNAI) corresponding to the user plane path of the PDU session of the terminal device, the tracking area identifier (TAI) of the terminal device, the cell identifier of the terminal device, the radio access network identifier of the terminal device, or the geographical location information of the terminal device.

11. The method according to claim 9 or 10, characterized in that, The target EAS and the source EAS serve the same application.

12. The method according to claim 9 or 10, characterized in that, The source EES acquires the first information, including: The source EES receives a third notification message from a Policy Control Function (PCF) entity or a Session Management Function (SMF) entity. The third notification message is used to notify the source EES that the user plane path of the PDU session of the terminal device has changed, and the third notification message includes the first information.

13. The method according to claim 12, characterized in that, The method further includes: The source EES subscribes to user plane management event notifications from the PCF entity or the SMF entity. The user plane management event notifications are used to notify the source EES when the user plane path of the PDU session of the terminal device changes.

14. The method according to any one of claims 9, 10, and 13, characterized in that, The subscription request includes information about the PDU session of the terminal device; the information about the PDU session of the terminal device includes at least one of the terminal device's network protocol IP address, data network name (DNN), or single network slice selection auxiliary information (S-NSSAI).

15. The method according to claim 14, characterized in that, The method further includes: The source EES determines the Policy Control Function (PCF) entity or the Session Management Function (SMF) entity based on the PDU session information of the terminal device.

16. The method according to any one of claims 9, 10, and 13, characterized in that, The subscription request includes application identification information. The source EES determines the target EAS based on the first information, including: The source EES determines the target EES based on the first information and the application identification information.

17. The method according to any one of claims 9, 10, and 13, characterized in that, The method further includes: The source EES sends a sixth indication message to the SMF, which is used to indicate whether the source EES supports application switching.

18. The method according to any one of claims 9, 10, and 13, characterized in that, The method further includes: The source EES receives a seventh indication from the source EAS, which indicates that service continuity needs to be maintained during application switching.

19. The method according to claim 18, characterized in that, The method further includes: The source EES sends an eighth indication message to the SMF or PCF, which is used to indicate that service continuity needs to be maintained during application switching.

20. The method according to any one of claims 9, 10, 13, and 19, characterized in that, The method further includes: The source EES sends the address information of the target EAS to the SMF or PCF.

21. An apparatus for application migration, characterized in that, The apparatus includes a unit for performing the application migration method as described in any one of claims 1-8.

22. An apparatus for application migration, characterized in that, The apparatus includes a unit for performing the application migration method as described in any one of claims 9-20.

23. An apparatus for application migration, characterized in that, The device includes: A transceiver is used to send and receive information, or to communicate with other network elements. A processor for executing computer program instructions to implement the application migration method as described in any one of claims 1-20.

24. A communication system, characterized in that, The communication system includes a source edge application server (EAS) and a source edge enable server (EES), wherein... The source EAS subscribes to the source EES for user plane management event notifications. The user plane management event notifications are used to notify the source EAS when the user plane path of the terminal device's Protocol Data Unit (PDU) session changes. The source EAS is the EAS accessed by the terminal device before the user plane path of the terminal device's PDU session changes. The source EES obtains first information, which is the location information of the terminal device after the user plane path of the PDU session of the terminal device has changed; the location information of the terminal device includes the data network access identifier (DNAI) corresponding to the user plane path of the PDU session of the terminal device. The source EES sends a second notification message to the source EAS. The second notification message is used to notify the source EAS that the user plane path of the PDU session of the terminal device has changed. The second notification message includes first information. Based on the first information, the source EAS determines the target EAS and sends the address information of the target EAS to the terminal device.

25. The communication system according to claim 24, characterized in that, The communication system also includes the terminal device; The terminal device receives the address information of the target EAS from the source EAS; The terminal device establishes a connection with the target EAS based on the address information of the target EAS.

26. A chip system, characterized in that, The chip system includes a processor and a memory, wherein the memory stores instructions; when the instructions are executed by the processor, they implement the application migration method as described in any one of claims 1-20.

27. A computer storage medium having computer program code therein, characterized in that, When the computer program code is run on a processor, it causes the processor to perform the application migration method as described in any one of claims 1-20.

28. A method for application migration, characterized in that, The method includes: The source edge application server (EAS) sends a subscription request to the source edge enable server (EES). The subscription request is used to notify the source EAS when the source EES determines that a target EAS exists in the data network DN that the terminal device can access. The source EES receives the subscription request from the source EAS; The source EES acquires first information, which is the location information of the terminal device after the user plane path of the protocol data unit (PDU) session of the terminal device has changed; the location information of the terminal device includes the data network access identifier (DNAI) corresponding to the user plane path of the PDU session of the terminal device. Based on the first information, the source EES determines that the target EAS exists in the DN that the terminal device indicated by the DNAI can access; The source EES sends a seventh notification message to the source EAS. The seventh notification message is used to indicate that a target EAS exists in the DN that the terminal device can access. The seventh notification message includes the address information of the target EAS. The source EAS receives the seventh notification message from the source EES; The source EAS determines to migrate the context of the terminal device from the source EAS to the target EAS.

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