CN114222341A

CN114222341A - Session connection method and session management functional entity

Info

Publication number: CN114222341A
Application number: CN202111571379.8A
Authority: CN
Inventors: 张伦泳
Original assignee: China United Network Communications Group Co Ltd
Current assignee: China United Network Communications Group Co Ltd
Priority date: 2021-12-21
Filing date: 2021-12-21
Publication date: 2022-03-22
Anticipated expiration: 2041-12-21
Also published as: CN114222341B

Abstract

The invention discloses a session continuing method and a session management functional entity, and relates to the technical field of communication. The method comprises the following steps: responding to migration failure reminding information for migrating the target session from the first mobile communication network to the second mobile communication network, and changing the next hop of the user terminal in the routing information corresponding to the target session to a target network entity; and sending the first session operation information to the access and mobility management functional entity so that the access and mobility management functional entity forwards the first session operation information to the user terminal, and enabling the user terminal to respond to the first session operation information and continue a target session with the correspondent node through the target network entity after the user terminal is switched from the first mobile communication network to the second mobile communication network. The invention can effectively ensure that the target session between the user terminal and the communication opposite terminal is not interrupted when the user terminal carries out network switching.

Description

Session connection method and session management functional entity

Technical Field

The invention relates to the technical field of communication, in particular to a session connection method, a session management functional entity, an access and mobility management functional entity and a user terminal.

Background

A User Equipment (UE) may establish a target session connection with a correspondent node in a target Data Network (DN) through a fifth Generation Mobile Communication Network (5th Generation Mobile Communication Technology, 5G). In case that the user terminal is handed over from the 5G network to a fourth Generation Mobile Communication network (4G), the 5G network will try to migrate the target session connection to the 4G network to ensure the continuity of the user session service.

However, if the 4G network and the target data network where the correspondent node is located are not interworked, the target session connection established by the user terminal in the 5G network cannot be migrated to the 4G network, which results in a session interruption between the user terminal and the correspondent node.

Disclosure of Invention

Therefore, the invention provides a session connection method, a session management function entity, an access and mobility management function entity and a user terminal, so as to solve the problem of session interruption caused by the fact that a mobile communication network after the user terminal is switched and a target data network where a communication opposite end is located are not communicated in the prior art.

In order to achieve the above object, a first aspect of the present invention provides a session connection method applied to a session management function entity in a first mobile communication network, the method including:

responding to migration failure reminding information for migrating a target session from a first mobile communication network to a second mobile communication network, and changing next hop of a user terminal in routing information corresponding to the target session to a target network entity; the target session is a session established by the user terminal and the communication opposite terminal through the first mobile communication network;

and sending first session operation information to an access and mobility management functional entity so that the access and mobility management functional entity forwards the first session operation information to a user terminal, and the user terminal responds to the first session operation information and continues the target session with the correspondent node through the target network entity after the user terminal is switched from the first mobile communication network to the second mobile communication network.

Optionally, the step of changing the next hop of the user equipment in the routing information corresponding to the target session to the target network entity includes:

sending an entity query request to the access and mobility management functional entity; the entity query request comprises a network identification of the second mobile communication network;

receiving an entity query result returned by the access and mobility management functional entity, wherein the entity query result is generated based on an entity identifier corresponding to a predetermined network entity included in each target data network after the access and mobility management functional entity determines at least one target data network from at least one data network connected with the second mobile communication network in response to the entity query request; the target data network is a data network connected with the first mobile communication network and including the predetermined network entity;

selecting a target entity identifier from at least one entity identifier included in the query result, and taking a predetermined network entity corresponding to the target entity identifier as the target network entity;

wherein the method further comprises: and sending the target entity identification to the access and mobility management functional entity so that the access and mobility management functional entity forwards the target entity identification to the user terminal.

Optionally, the predetermined network entity is a non-third generation partnership project interoperability function entity.

Optionally, the method further comprises:

sending second session operation information to an access and mobility management functional entity so that the access and mobility management functional entity forwards the second session operation information to a target network entity; the second session operation information is used for enabling the target network entity to cache first session data corresponding to the target session; the first session data is session data sent by the correspondent node to the user terminal.

A second aspect of the present invention provides a session connection method, applied to an access and mobility management function entity in a first mobile communication network, including:

receiving first session operation information sent by a session management functional entity; the first session operation information is information sent by the session management function entity after the next hop of the user terminal in the routing information corresponding to the target session is changed to a predetermined target network entity in response to the migration failure reminding information for migrating the target session from the first mobile communication network to the second mobile communication network; the target session is a session established by the user terminal and the communication opposite terminal through the first mobile communication network;

and forwarding the first session operation information to the user terminal so that the user terminal responds to the first session operation information and continues the target session with the correspondent node through the target network entity after the user terminal is switched to the second mobile communication network.

Optionally, before receiving the first session operation information sent by the session management function entity, the method further includes:

receiving an entity query request sent by the session management functional entity; the entity query request comprises a network identification of the second mobile communication network;

determining at least one target data network from at least one data network connected to the second mobile communication network acquired in advance; the target data network is a data network connected with the first mobile communication network and including a predetermined network entity;

generating an entity query result based on entity identifications corresponding to predetermined network entities contained in each target data network;

returning the entity query result to the session management function entity so that the session management function entity selects a target entity identifier from at least one entity identifier included in the query result, and taking a predetermined network entity corresponding to the target entity identifier as the target network entity;

receiving a target entity identifier returned by the session management functional entity;

and sending the target entity identification to a user terminal, so that the user terminal determines a target network entity needing to establish connection based on the target entity identification after switching from the first mobile communication network to the second mobile communication network.

Optionally, after receiving the target entity identifier returned by the session management function entity, the method further includes:

sending control information to a target network entity corresponding to the target entity identifier, wherein the control information comprises a user identifier corresponding to the user terminal;

receiving user registration information corresponding to the user identification forwarded by the target network entity in response to the control information; the user registration information is information that the user terminal requests user registration in a first mobile communication network;

and performing user registration on the user terminal in the first mobile communication network according to the user registration information.

The third aspect of the present invention provides a session connection method, applied to a user equipment, where the method includes:

receiving first session operation information forwarded by an access and mobility management functional entity; the first session operation information is information which is sent by a session management function entity after a next hop of a user terminal in routing information corresponding to a target session is changed into a predetermined target network entity in response to migration failure reminding information for migrating the target session from a first mobile communication network to a second mobile communication network; the target session is a session established with a correspondent node through a first mobile communication network;

and responding to the first session operation information, and continuing the target session with the correspondent node through the target network entity under the condition of switching from the first mobile communication network to the second mobile communication network.

Optionally, before continuing the target session with the correspondent through the target network entity in case of switching from the first mobile communication network to the second mobile communication network in response to the first session operation information, the method further includes:

receiving a target entity identification sent by an access and mobility management functional entity;

under the condition of switching from the first mobile communication network to the second mobile communication network, establishing tunnel connection with a target network entity corresponding to the target entity identification;

and sending network registration information to the target network entity through the tunnel connection, so that the target network entity responds to the control information received in advance and sends the network registration information to an access and mobility management functional entity, and the access and mobility management functional entity performs user registration in the first mobile communication network.

Optionally, the step of continuing the target session with the correspondent node through the target network entity includes:

receiving first session data cached in advance by the target network entity through the tunnel connection; the first session data is session data sent by the correspondent node to the user terminal;

and sending second session data to the target network entity through the tunnel connection so that the target network entity sends the second session data to the correspondent node through a user plane function entity in the first mobile communication network.

A fourth aspect of the present invention provides a session management function entity, including:

the session processing module is used for responding to migration failure reminding information for migrating the target session from the first mobile communication network to the second mobile communication network, and enabling next hop of the user terminal in the routing information corresponding to the target session to be a predetermined target network entity; the target session is a session established by the user terminal and the communication opposite terminal through the first mobile communication network;

a first sending module, configured to send first session operation information to an access and mobility management functional entity, so that the access and mobility management functional entity forwards the first session operation information to a user terminal, and the user terminal responds to the first session operation information, and continues the target session with the correspondent node through the target network entity after switching from the first mobile communication network to the second mobile communication network.

A fifth aspect of the present invention provides an access and mobility management functional entity, including:

the second receiving module is used for receiving the first session operation information sent by the session management functional entity; the first session operation information is information sent by the session management function entity after the next hop of the user terminal in the routing information corresponding to the target session is changed to a predetermined target network entity in response to the migration failure reminding information for migrating the target session from the first mobile communication network to the second mobile communication network; the target session is a session established by the user terminal and the communication opposite terminal through the first mobile communication network;

a second sending module, configured to forward the first session operation information to a user terminal, so that the user terminal responds to the first session operation information and continues the target session with the correspondent node through the target network entity after switching to the second mobile communication network.

A sixth aspect of the present invention provides a user terminal, including:

the terminal receiving module is used for receiving the first session operation information forwarded by the access and mobility management functional entity; the first session operation information is information which is sent by a session management function entity after a next hop of a user terminal in routing information corresponding to a target session is changed into a predetermined target network entity in response to migration failure reminding information for migrating the target session from a first mobile communication network to a second mobile communication network; the target session is a session established with a correspondent node through a first mobile communication network;

and the terminal processing module is used for responding to the first session operation information, and continuing the target session with the communication opposite terminal through the target network entity under the condition of switching from the first mobile communication network to the second mobile communication network.

The invention has the following advantages:

the invention provides a session continuing method, which comprises the following steps: responding to migration failure reminding information for migrating the target session from the first mobile communication network to the second mobile communication network, and changing the next hop of the user terminal in the routing information corresponding to the target session to a target network entity; the first session operation information is sent to the access and mobility management functional entity, so that the access and mobility management functional entity forwards the first session operation information to the user terminal, the user terminal responds to the first session operation information, after the user terminal is switched from the first mobile communication network to the second mobile communication network, the target session with the communication opposite end is continued through the target network entity, and the target session between the user terminal and the communication opposite end can be effectively ensured not to be interrupted under the condition that the second mobile communication network switched by the user terminal is not communicated with the target data network where the communication opposite end is located.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.

Fig. 1 is a flowchart of a session connection method according to an embodiment of the present invention;

fig. 2 is a schematic view of an application scenario provided in the embodiment of the present invention;

fig. 3 is a flowchart illustrating a method for determining a target network entity according to an embodiment of the present invention;

fig. 4 is a flowchart of another session connection method according to an embodiment of the present invention;

fig. 5 is a flowchart of another session connection method according to an embodiment of the present invention;

fig. 6 is a flowchart of another session connection method according to an embodiment of the present invention;

fig. 7 is a schematic view of another application scenario provided in the embodiment of the present invention;

fig. 8 is a schematic structural diagram of a session management function entity according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of an access and mobility management functional entity according to an embodiment of the present invention;

fig. 10 is a schematic structural diagram of a user terminal according to an embodiment of the present invention;

fig. 11 is a signaling diagram of another session connection method according to an embodiment of the present invention.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

When the terms "comprises" and/or "comprising … …" are used in this specification, the presence of stated features, integers, steps, operations, elements, and/or components are specified, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

The embodiments of the invention may be described with reference to plan and/or cross-sectional views in idealized schematic representations of the invention. Accordingly, the example illustrations can be modified in accordance with manufacturing techniques and/or tolerances.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present invention and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Fig. 1 is a flowchart of a session connection method according to an embodiment of the present invention. The Session connection method is applied to a Session Management Function (SMF) in a first mobile communication network. Wherein the first mobile communication network is a 5G network, the first mobile communication network further comprising: access and mobility Management Function (AMF), User Plane Function (UPF), etc.

As shown in fig. 1, the session connection method includes: step S101-step S102.

Step S101, responding to the migration failure reminding information for migrating the target session from the first mobile communication network to the second mobile communication network, and changing the next jump of the user terminal in the routing information corresponding to the target session to a target network entity.

The target session is a session established by the user terminal and the communication opposite end through the first mobile communication network.

The second mobile communication network, e.g. a 4G network, is the mobile communication network to which the user terminal is currently prepared to be handed over.

The migration failure reminding information is information which is sent by the second mobile communication network to the first mobile communication network and used for reminding the target session of migration failure. The migration failure reminding information comprises: one or more kinds of information such as a session identifier of the target session, a mobile network identifier of the second mobile communication network, an IP Address (Internet Protocol Address) of the correspondent node, and a failure reason. The failure reason is that the second mobile communication network is not connected with the data network where the communication opposite end is located, that is, the IP address of the communication opposite end is not reachable by the second mobile communication network.

The routing information corresponding to the target session comprises path information for routing the session data of the target session from the user terminal to the correspondent node. The next hop of the user terminal refers to a next routing node to which the session data of the target session is directed after being sent by the user terminal, and the routing node and the user terminal can be connected through at least one router and/or a switch.

The target network entity is a network entity for enabling the ue to access the first mobile communication network after handover to the second mobile communication network, for example, the target network entity is a Non-third generation partnership project interworking Function (N3 IWF), and the N3IWF is used for assisting the ue to access the first mobile communication network through a Non-3GPP manner, i.e., not through a radio access network defined by 3 GPP.

Fig. 2 is a schematic view of an application scenario provided in the embodiment of the present invention. As shown in fig. 2, the first mobile communication Network 21 includes a 5G access Network (5G radio access Network, 5G-RAN)210 and a 5G Core Network (5G Core Network, 5GC)211, and the 5G Core Network 211 includes: AMF2111, SMF2112 and UPF 2113. The user terminal 22 accesses the first mobile communication network 21 through the 5G access network 210, and establishes a communication connection with the AMF2111 in the 5G core network. The 5G core network 211 is connected to a first data network 23 and a second data network 24. The second mobile communication network 25 is connected to the first data network 23 but not to the second data network 24. The first data network 23 includes an N3IWF attributed to the 5G core network 211. The correspondent is located in the second data network 24. It should be noted that the data network is a service network carried on the mobile communication network, and is a network system composed of devices such as a terminal, a transmission device, a switching device, and a processing device, and is used for carrying a plurality of services and application systems.

In this scenario, the user terminal and the correspondent node in the second data network establish a target session through the first mobile communication network. The current data transmission process of the target session is shown by a dotted line in fig. 2: the user terminal 22 is transmitted to the 5G access network 210, then to the UPF2113 by the 5G access network 210, and then to the correspondent node in the second data network 24 by the UPF2113, otherwise to the user terminal 22 by the correspondent node along the path.

When the user terminal needs to be switched from the first mobile communication network to the second mobile communication network, in order to avoid interruption of the target session, the first mobile communication network attempts to transfer the session connection established by the user terminal in the first mobile communication network to the second mobile communication network, that is, to transfer the target session established by the user terminal and the correspondent node to the second mobile communication network.

However, during the migration of the target session, the second mobile communication network may recognize that the second data network where the correspondent node corresponding to the target session is located does not have communication connection, that is, the IP address of the correspondent node is not reachable. In this case, the second mobile communication network generates migration failure notification information, and sends the migration failure notification information to the first mobile communication network. The AMF in the first mobile communication network receives the migration failure reminding message, and forwards the migration failure reminding message to the SMF, and the SMF performs the step S101.

In one embodiment, the step of the session management functional entity changing the next hop of the ue in the routing information corresponding to the target session to the target network entity in step S101 includes: and determining a target network entity, and changing the next hop of the user terminal in the routing information corresponding to the target session to the target network entity.

Fig. 3 is a flowchart illustrating a method for determining a target network entity according to an embodiment of the present invention, which is applied to a session management function entity. As shown in fig. 3, the method for determining a target network entity includes: step S301 to step S303.

Step S301, sending an entity query request to an access and mobility management functional entity.

Wherein the entity query request is a request for querying a predetermined network entity belonging to the first mobile communication network included in a data network connected to both the second mobile communication network and the first mobile communication network. The entity query request includes a network identification of the second mobile communication network and a terminal identification of the user terminal.

In one embodiment, the predetermined network entity may be an N3 IWF.

In one embodiment, the access and mobility management function entity determines, in response to the entity query request, at least one target data network from among the at least one data network previously acquired in connection with the second mobile communication network, wherein the target data network is a data network connected to the first mobile communication network and containing a predetermined network entity belonging to the first mobile communication network. After at least one target data network is determined, the access and mobility management functional entity generates a query result based on an entity identifier corresponding to a predetermined network entity contained in each target data network, and returns the query result to the session management functional entity, wherein the entity identifier corresponding to the predetermined network entity is the unique identity identifier of the predetermined network entity.

And step S302, receiving an entity query result returned by the access and mobility management functional entity.

The entity query result is generated based on the entity identifier corresponding to the predetermined network entity included in each target data network after the access and mobility management functional entity determines at least one target data network from at least one data network connected with the second mobile communication network in response to the entity query request. The query result includes: an entity identity of at least one predetermined network entity.

Step S303, selecting a target entity identifier from the at least one entity identifier included in the query result, and using a predetermined network entity corresponding to the target entity identifier as a target network entity.

In an embodiment, the session management functional entity may randomly select one entity identifier from at least one entity identifier included in the query result as the target entity identifier, or may select one entity identifier as the target entity identifier according to a preset rule, where the preset rule may be set according to an actual application scenario, and is not specifically limited in this embodiment.

In this embodiment, the session management functional entity obtains, through the above steps S301 to S303, a target network entity capable of providing a service for the user equipment to access the first mobile communication network in a non-3GPP manner.

In an embodiment, after determining the target network entity, the session management function entity further sends a target entity identifier to the access and mobility management function entity, so that the access and mobility management function entity forwards the target entity identifier to the user terminal, and the user terminal may determine the target network entity needing to establish a connection by using the target entity identifier when the user terminal needs to establish a connection with the target network entity.

In an embodiment, the step of changing the next hop of the ue in the routing information corresponding to the target session to the target network entity includes: and configuring the next hop of the user terminal in the routing information as a target network entity from the communication opposite end, and configuring the next hop of the target network entity as the communication opposite end at the same time.

It should be noted that the "next hop" in this embodiment represents a next routing node pointed to by the present routing node, where the present routing node and the next routing node are connected through at least one router and/or switch.

It should be further noted that, in an actual application scenario, the step of the session management functional entity changing the next hop of the user terminal in the routing information corresponding to the target session to the target network entity may be implemented by initiating a session change procedure. The specific process of the session management function initiating the session change procedure can be detailed in section 4 of 3GPP TS23.502, which is not specifically limited in this embodiment.

In one embodiment, after the session management functional entity changes the next hop of the ue in the routing information corresponding to the target session to the target network entity, the method further includes: first session operation information is generated.

The first session operation information is information for instructing the user terminal to continue a target session with the correspondent node through the target network entity. The first session operation information includes a session identification of the target session.

Step S102, sending the first session operation information to the access and mobility management functional entity, so that the access and mobility management functional entity forwards the first session operation information to the user terminal, and the user terminal responds to the first session operation information, and after the user terminal is switched from the first mobile communication network to the second mobile communication network, continuing the target session with the correspondent node through the target network entity.

In one embodiment, after the user terminal is switched from the first mobile communication network to the second mobile communication network in response to the first session operation information, the user terminal establishes a tunnel connection with the target network entity and sends session data to the target network entity through the tunnel connection, so that the target network entity sends the session data to the correspondent node through the first mobile communication network, and connection of a target session between the user terminal and the correspondent node is realized.

In one embodiment, in order to avoid loss of session data sent by the correspondent node to the user terminal during the target session migration, the session management functional entity further sends second session operation information to the access and mobility management functional entity, so that the access and mobility management functional entity forwards the second session operation information to the target network entity. The second session operation information is used for enabling the target network entity to cache first session data corresponding to the target session, and the first session data is session data sent by the communication opposite end to the user terminal.

It should be noted that the execution time of the step of the session management function entity sending the second session operation information to the access and mobility management function entity is not specifically limited, for example, the step may be executed after determining the target network entity and before sending the first session operation information to the access and mobility management function entity, or may be executed after sending the first session operation information to the access and mobility management function entity, or may be executed simultaneously with the step of sending the first session operation information to the access and mobility management function entity.

The embodiment of the invention provides a session continuing method applied to a session management function entity in a first mobile communication network, which comprises the steps of responding to migration failure reminding information for migrating a target session from the first mobile communication network to a second mobile communication network, and changing the next jump of a user terminal in routing information corresponding to the target session into a target network entity; then, sending the first session operation information to the access and mobility management functional entity, so that the access and mobility management functional entity forwards the first session operation information to the user terminal, and the user terminal responds to the first session operation information, and after the user terminal is switched from the first mobile communication network to the second mobile communication network, continuing the target session with the correspondent node through the target network entity, so that the target session between the user terminal and the correspondent node can be effectively ensured not to be interrupted under the condition that the second mobile communication network switched by the user terminal is not intercommunicated with the target data network where the correspondent node is located.

Fig. 4 is a flowchart of another session connection method according to an embodiment of the present invention. The session joining method is applied to an access and mobility management function entity in a first mobile communication network. As shown in fig. 4, the another session connection method includes: step S401 to step S402.

Step S401, receiving the first session operation information sent by the session management functional entity.

The first session operation information is information sent by the session management function entity after the next hop of the user terminal in the routing information corresponding to the target session is changed to a predetermined target network entity in response to the migration failure reminding information for migrating the target session from the first mobile communication network to the second mobile communication network. The target session is a session established by the user terminal with the correspondent node through the first mobile communication network.

In one embodiment, the first session operation information comprises a session identification of the target session and a terminal identification of the user terminal.

Step S402, the first session operation information is forwarded to the user terminal, so that the user terminal responds to the first session operation information and continues the target session with the correspondent node through the target network entity after switching to the second mobile communication network.

In one embodiment, the step of forwarding the first session operation information to the user terminal by the access and mobility management functional entity comprises: and extracting a terminal identifier from the first session operation information, and sending the first session operation information to the user terminal corresponding to the terminal identifier.

The embodiment of the invention provides a session continuing method applied to an access and mobility management functional entity of a first mobile communication network, which comprises the steps of firstly, receiving first session operation information sent by the session management functional entity, wherein the first session operation information is information sent by the session management functional entity after responding to migration failure reminding information for migrating a target session from the first mobile communication network to a second mobile communication network and changing the next jump of a user terminal in routing information corresponding to the target session to a predetermined target network entity; and then, the first session operation information is forwarded to the user terminal, so that the user terminal responds to the first session operation information, and continues the target session with the correspondent node through the target network entity after switching to the second mobile communication network, thereby effectively ensuring that the target session between the user terminal and the correspondent node is not interrupted under the condition that the second mobile communication network switched by the user terminal is not intercommunicated with the target data network where the correspondent node is located.

Fig. 5 is a flowchart of another session connection method according to an embodiment of the present invention. In an embodiment, before the access and mobility management functional entity receives the first session operation information sent by the session management functional entity (step S401 above), as shown in fig. 5, the method further includes: step S501 to step S504.

Step S501, an entity query request sent by the session management function entity is received.

In one embodiment, after receiving the entity query request sent by the session management function entity, the access and mobility management function entity acquires at least one data network connected with the second mobile communication network based on the network identification of the second mobile communication network in the entity query request.

In some embodiments, the step of the access and mobility management function entity acquiring at least one data network connected to the second mobile communications network comprises: and sending a data network query request to the second mobile communication network so that the second mobile communication network can return a network query result based on the data network query request. The network query result includes a network identification of at least one data network connected to the second mobile communication network.

In further embodiments, the step of the access and mobility management functional entity acquiring at least one data network connected to the second mobile communications network comprises: the network identification of at least one data network connected to the second mobile communication network is retrieved from a local database.

The local database is a database which is exclusive to the access and mobility management functional entity, and network query results obtained by the previous query of the access and mobility management functional entity are stored in the local database. The network query result obtained by the previous query may be data stored in the local database by the access and mobility management function entity, or may be a network query result automatically cached by the local database.

In still other embodiments, the step of the access and mobility management functional entity acquiring at least one data network connected to the second mobile communications network comprises: the network identification of the at least one Data network connected to the second mobile communication network is obtained from a Unified Data Storage Function (UDR) or Unstructured Data Storage Function (UDSF).

Wherein, the UDR and the UDSF store data network reachability information, the data network reachability information comprises network identification of at least one data network connected with the second mobile communication network and network identification of at least one data network connected with the first mobile communication network. Sources of data network reachability information stored in the UDR or UDSF include, but are not limited to, any of:

the first, first and second mobile communication networks have a predetermined agreement therebetween to exchange data network reachability information, which is stored in the UDR or UDSF, with each other.

In the second, the administrator of the first mobile communication network manually stores the data network reachability information configuration in the UDR or UDSF.

It should be noted that the first mobile communication network and the second mobile communication network are respectively connected with a plurality of data networks, and both of them may be simultaneously connected with the same data network. The user terminal can access the first mobile communication network only after being handed over from the first mobile communication network to the second mobile communication network through the data network simultaneously connected with the first mobile communication network and the second mobile communication network.

Step S502, determining at least one target data network from at least one data network connected to the second mobile communication network acquired in advance.

Wherein the target data network is a data network connected to the first mobile communication network and comprising a predetermined network entity belonging to the first mobile communication network. The predetermined network entity may be an N3 IWF.

In this embodiment, since the target data network is determined from at least one data network connected to the second mobile communication network, the determined at least one target data network is connected to both the first mobile communication network and the second mobile communication network and includes a predetermined network entity belonging to the first mobile communication network. The predetermined network entities included in each target data network can provide the service for the user terminal to access the first mobile communication network in a non-3GPP mode.

Step S503, generating an entity query result based on the entity identifier corresponding to the predetermined network entity included in each target data network.

The entity query result includes entity identifiers corresponding to predetermined network entities included in each target data network.

Step S504, returning the entity query result to the session management function entity, so that the session management function entity selects a target entity identifier from the at least one entity identifier included in the query result, and takes a predetermined network entity corresponding to the target entity identifier as a target network entity.

The target entity identifier is an entity identifier randomly selected by the session management function from at least one entity identifier included in the query result, or an entity identifier selected by the session management function according to a preset rule from at least one entity identifier included in the query result

In one embodiment, after the entity query result is returned to the session management function entity, the session continuation method further includes:

receiving a target entity identifier returned by the session management function entity, and sending the target entity identifier to the user terminal, so that the user terminal can determine a target network entity needing to establish connection by virtue of the target entity identifier after switching from the first mobile communication network to the second mobile communication network.

In one embodiment, after the access and mobility management function entity receives the target entity identifier returned by the session management function entity, the session connection method further includes the following steps one to three.

Step one, control information is sent to a target network entity corresponding to a target entity identification.

The control information is used for indicating the target network entity to forward the user registration information to an access and mobility management function entity in the first mobile communication network after receiving the user registration information of the user terminal. The control information includes a user identifier corresponding to the user terminal.

The user registration information is information that the user terminal requests user registration in the first mobile communication network.

And step two, receiving user registration information corresponding to the user identification forwarded by the target network entity in response to the control information.

The user registration information is a request sent by the target network entity for requesting user registration in the first mobile communication network when the user terminal needs to continue the target session through the target network entity and establish connection with the target network entity after being switched from the first mobile communication network to the second mobile communication network.

And step three, performing user registration on the user terminal in the first mobile communication network according to the user registration information.

In this step, the process of the access and mobility management functional entity performing the user registration on the user terminal in the first mobile communication network according to the user registration information may refer to a registration flow of the user terminal in the 5G network in the prior art or related art, which is not specifically limited in this embodiment.

In this embodiment, after the access and mobility management functional entity completes the user registration process of the user terminal in the first mobile communication network, the first mobile communication network may provide a communication service for the user terminal that is accessed to itself through the target network entity, and further may assist the user terminal to continue the target session with the correspondent node through the target network entity.

Fig. 6 is a flowchart of another session connection method according to an embodiment of the present invention. The session continuing method is applied to the user terminal. As shown in fig. 6, the session access method includes: step S601-step S602.

Step S601, receiving the first session operation information forwarded by the access and mobility management functional entity.

The first session operation information is information sent by the session management function entity after the next hop of the user terminal in the routing information corresponding to the target session is changed to a predetermined target network entity in response to the migration failure reminding information for migrating the target session from the first mobile communication network to the second mobile communication network. The target session is a session established with a correspondent node through the first mobile communication network.

The target network entity is a network entity for enabling the user terminal to access the first mobile communication network after handover to the second mobile communication network, e.g. the target network entity is an N3 IWF.

It should be noted that the first session operation information is information for instructing the user terminal to continue the target session with the correspondent node through the target network entity. Therefore, after receiving the first session operation information, the user terminal can know how to continue the target session with the correspondent node in the case of switching from the first mobile communication network to the second mobile communication network.

Step S602, responding to the first session operation information, and continuing the target session with the correspondent node through the target network entity under the condition of switching from the first mobile communication network to the second mobile communication network.

The case of switching from the first mobile communication network to the second mobile communication network includes, but is not limited to, any one of the following:

in case one, the user terminal leaves the coverage of the first mobile communication network and enters the coverage of the second mobile communication network, the user terminal selects handover from the first mobile communication network to the second mobile communication network.

In case two, the coverage areas of the first mobile communication network and the second mobile communication network overlap, but the user terminal selects the second mobile communication network when reselecting the network.

In this embodiment, the target network entity is configured to enable the ue to access the first mobile communication network after being switched to the second mobile communication network, so that the ue can first establish a connection with the target network entity, then access the first mobile communication network through the target network entity, and then continue a target session originally established with the correspondent node in the first mobile communication network.

In one embodiment, the session connection method further includes:

step one, receiving a target entity identification sent by an access and mobility management functional entity.

Wherein the target entity identification is a unique identity of the target network entity.

In this embodiment, after receiving the target entity identifier, the user terminal may determine, by using the target entity identifier, the target network entity that needs to establish the connection, under the condition that the connection with the target network entity needs to be established.

And step two, under the condition of switching from the first mobile communication network to the second mobile communication network, establishing tunnel connection with a target network entity corresponding to the target entity identification.

In this embodiment, when the user terminal is handed over from the first mobile communication network to the second mobile communication network, it is the second mobile communication network that currently provides the communication service for the user terminal. Therefore, the step of establishing a tunnel connection with the target network entity corresponding to the target entity identifier includes: and establishing tunnel connection with the target network entity corresponding to the target entity identification through the second mobile communication network.

The process of establishing the tunnel connection may participate in the process of establishing the tunnel connection in the corresponding technology, and is not specifically limited in this embodiment.

It should be noted that, after the user terminal establishes the tunnel connection with the target network entity, in order to obtain the communication service provided by the first mobile communication network through the target network entity, the user terminal needs to perform user registration in the first mobile communication network.

And step three, sending the network registration information to the target network entity through the tunnel connection, so that the target network entity responds to the control information received in advance and sends the network registration information to the access and mobility management functional entity, and the access and mobility management functional entity performs user registration in the first mobile communication network.

The network registration information includes information such as a terminal identifier of the user terminal, protocol data for interacting with the first mobile communication network, and the like.

The control information is information for instructing the target network entity to forward the user registration information to the access and mobility management function entity in the first mobile communication network after receiving the user registration information of the user terminal.

In this embodiment, after the access and mobility management functional entity completes the user registration process of the user terminal in the first mobile communication network, the first mobile communication network may provide a communication service for the user terminal that is accessed to itself through the target network entity.

Fig. 7 is a schematic view of another application scenario provided in the embodiment of the present invention. As shown in fig. 7, the first mobile communication network 21 includes a 5G core network 211, and the 5G core network 211 includes: AMF2111, SMF2112 and UPF 2113. The 5G core network 211 is connected to a first data network 23 and a second data network 24. The second mobile communication network 25 is connected to the first data network 23 but not to the second data network 24. The first data network 23 includes an N3IWF attributed to the 5G core network 211. The correspondent is located in the second data network 24. The user terminal 22 establishes a tunnel connection with the N3IWF in the first data network 23 through the second mobile communication network 25, as indicated by the dashed line L1 in fig. 7. The communication connection of the target network entity N3IWF with the correspondent node is shown by the dashed line L2 in fig. 7.

In this scenario, the step of the user terminal continuing the target session with the correspondent node through the target network entity N3IWF includes the following fourth and fifth steps.

And step four, receiving the first session data cached in advance by the target network entity through the tunnel connection.

The first session data is session data sent by the correspondent node to the user terminal.

In this embodiment, the step of receiving, by the user terminal, the first session data pre-cached by the target network entity can effectively prevent the user terminal from missing the session data sent by the correspondent node in the process of switching the user terminal from the first mobile communication network to the second mobile communication network, and meanwhile, the user terminal can receive the session data from the correspondent node in real time after completing the user registration in the first mobile communication network through the tunnel connection.

And step five, sending the second session data to the target network entity through the tunnel connection so that the target network entity sends the second session data to the communication opposite terminal through the user plane function entity in the first mobile communication network.

And the second session data is session data which needs to be sent to the opposite communication terminal by the user terminal.

The embodiment of the invention provides a session continuing method applied to a user terminal, which comprises the steps of firstly, receiving first session operation information forwarded by an access and mobility management functional entity, wherein the first session operation information is information sent by the session management functional entity after responding to migration failure reminding information for migrating a target session from a first mobile communication network to a second mobile communication network and enabling next jump of the user terminal in routing information corresponding to the target session to be more than a predetermined target network entity; the target session is a session established with a correspondent node through a first mobile communication network; then, responding to the first session operation information, and under the condition of switching from the first mobile communication network to the second mobile communication network, continuing the target session with the correspondent node through the target network entity, and under the condition that the second mobile communication network switched by the user terminal is not intercommunicated with the target data network where the correspondent node is located, effectively ensuring that the target session between the user terminal and the correspondent node is not interrupted.

The steps of the above methods are divided for clarity, and the implementation may be combined into one step or split some steps, and the steps are divided into multiple steps, so long as the same logical relationship is included, which are all within the protection scope of the present patent; it is within the scope of the patent to add insignificant modifications to the algorithms or processes or to introduce insignificant design changes to the core design without changing the algorithms or processes.

Fig. 8 is a schematic structural diagram of a session management function entity according to an embodiment of the present invention. Wherein the session management function entity is an entity belonging to a first mobile communication network, such as a 5G network. As shown in fig. 8, the session management function entity includes: a session handling module 81 and a first sending module 82.

The session processing module 81 is configured to, in response to the migration failure reminding information for migrating the target session from the first mobile communication network to the second mobile communication network, update the next hop of the user terminal in the routing information corresponding to the target session to a predetermined target network entity.

The target session is a session established by the user terminal and the communication opposite end through the first mobile communication network. The predetermined network entity is a non-third generation partnership project interoperability function entity.

A first sending module 82, configured to send the first session operation information to the access and mobility management function entity, so that the access and mobility management function entity forwards the first session operation information to the user terminal, and so that the user terminal responds to the first session operation information and continues a target session with a correspondent node through the target network entity after switching from the first mobile communication network to the second mobile communication network.

In one embodiment, the session processing module 81 includes a sending submodule, a receiving submodule, and a selecting submodule.

The sending submodule is used for sending an entity query request to the access and mobility management functional entity, wherein the entity query request comprises a network identifier of the second mobile communication network.

The receiving submodule is used for receiving an entity query result returned by the access and mobility management functional entity, wherein the entity query result is generated based on an entity identifier corresponding to a predetermined network entity contained in each target data network after the access and mobility management functional entity determines at least one target data network from at least one data network connected with the second mobile communication network in response to an entity query request; the target data network is a data network connected to the first mobile communication network and comprising a predetermined network entity.

And the selection sub-module is used for selecting a target entity identifier from at least one entity identifier included in the query result and taking a predetermined network entity corresponding to the target entity identifier as a target network entity.

In an embodiment, the first sending module 82 is further configured to send the target entity identifier to the access and mobility management functional entity, so that the access and mobility management functional entity forwards the target entity identifier to the user terminal.

In one embodiment, the first sending module 82 is further configured to send the second session operation information to the access and mobility management function entity, so that the access and mobility management function entity forwards the second session operation information to the target network entity.

The second session operation information is used for enabling the target network entity to cache first session data corresponding to the target session, and the first session data is session data sent by the communication opposite end to the user terminal.

The embodiment of the invention provides a session management functional entity, which comprises: the session processing module is used for responding to migration failure reminding information for migrating the target session from the first mobile communication network to the second mobile communication network, and changing the next hop of the user terminal in the routing information corresponding to the target session into a target network entity; the first sending module is used for sending the first session operation information to the access and mobility management functional entity so that the access and mobility management functional entity forwards the first session operation information to the user terminal, and the user terminal responds to the first session operation information, and after the user terminal is switched from the first mobile communication network to the second mobile communication network, the target session with the communication opposite terminal is continued through the target network entity, so that the target session between the user terminal and the communication opposite terminal can be effectively ensured not to be interrupted under the condition that the second mobile communication network switched by the user terminal is not communicated with the target data network where the communication opposite terminal is located.

Fig. 9 is a schematic structural diagram of an access and mobility management functional entity according to an embodiment of the present invention. The access and mobility management function entity is an entity belonging to the first mobile communication network. As shown in fig. 9, the access and mobility management functional entity includes: a second receiving module 91 and a second transmitting module 92.

The second receiving module 91 is configured to receive the first session operation information sent by the session management functional entity.

Wherein. The first session operation information is information sent by the session management function entity after the next hop of the user terminal in the routing information corresponding to the target session is changed to a predetermined target network entity in response to the migration failure reminding information for migrating the target session from the first mobile communication network to the second mobile communication network. The target session is a session established by the user terminal with the correspondent node through the first mobile communication network.

And a second sending module 92, configured to forward the first session operation information to the user terminal, so that the user terminal responds to the first session operation information and continues the target session with the correspondent node through the target network entity after switching to the second mobile communication network.

In one embodiment, the access and mobility management functional entity further includes an AMF processing module, an AMF generating module, and a third sending module.

The second receiving module 91 is further configured to receive an entity query request sent by the session management function entity, where the entity query request includes a network identifier of the second mobile communication network.

The AMF processing module is configured to determine at least one target data network from at least one data network acquired in advance and connected to the second mobile communication network.

Wherein the target data network is a data network connected to the first mobile communication network and comprising a predetermined network entity.

The AMF generation module is configured to generate an entity query result based on an entity identifier corresponding to a predetermined network entity included in each target data network.

The third sending module is configured to return the entity query result to the session management function entity, so that the session management function entity selects a target entity identifier from the at least one entity identifier included in the query result, and uses a predetermined network entity corresponding to the target entity identifier as the target network entity.

The second receiving module 91 is further configured to receive a target entity identifier returned by the session management function entity.

The second sending module 92 is further configured to send the target entity identifier to the user terminal, so that the user terminal establishes a tunnel connection with the target network entity corresponding to the target entity identifier after switching from the first mobile communication network to the second mobile communication network.

In one embodiment, the access and mobility management functional entity further includes a third receiving module, a fourth sending module and a registration module.

The fourth sending module is configured to send control information to a target network entity corresponding to the target entity identifier, where the control information includes a user identifier corresponding to the user terminal.

A third receiving module, configured to receive user registration information corresponding to the user identifier forwarded by the target network entity in response to the control information, where the user registration information is information for a user terminal to request user registration in the first mobile communication network.

And the registration module performs user registration on the user terminal in the first mobile communication network every day according to the user registration information.

The embodiment of the invention provides an access and mobility management functional entity, which comprises the following components: a second receiving module, configured to receive first session operation information sent by a session management function entity, where the first session operation information is information sent by the session management function entity after a next hop of a user terminal in routing information corresponding to a target session is changed to a predetermined target network entity in response to a migration failure notification message for migrating the target session from a first mobile communication network to a second mobile communication network; the second sending module is used for forwarding the first session operation information to the user terminal so that the user terminal responds to the first session operation information, continues the target session with the correspondent node through the target network entity after being switched to the second mobile communication network, and can effectively ensure that the target session between the user terminal and the correspondent node is not interrupted under the condition that the second mobile communication network switched by the user terminal is not intercommunicated with the target data network where the correspondent node is located.

Fig. 10 is a schematic structural diagram of a user terminal according to an embodiment of the present invention. As shown in fig. 10, the user terminal includes: a terminal reception module 1001 and a terminal processing module 1002.

The terminal receiving module 1001 is configured to receive the first session operation information forwarded by the access and mobility management functional entity.

And the terminal processing module 1002 is configured to respond to the first session operation information, and continue the target session with the correspondent node through the target network entity in case of switching from the first mobile communication network to the second mobile communication network.

In an embodiment, the terminal receiving module 1001 is further configured to receive a target entity identifier sent by the access and mobility management functional entity.

The terminal processing module 1002 is further configured to establish a tunnel connection with a target network entity corresponding to a target entity identifier when the first mobile communication network is switched to the second mobile communication network; and sending the network registration information to the target network entity through the tunnel connection, so that the target network entity responds to the control information received in advance and sends the network registration information to the access and mobility management functional entity, and the access and mobility management functional entity performs user registration in the first mobile communication network.

In one embodiment, the terminal processing module 1002 includes a terminal receiving sub-module and a terminal sending sub-module.

And the terminal receiving submodule is used for receiving first session data cached in advance by the target network entity through tunnel connection, wherein the first session data is session data sent to the user terminal by the communication opposite terminal.

And the terminal sending submodule is used for sending the second session data to the target network entity through the tunnel connection so that the target network entity sends the second session data to the communication opposite terminal through the user plane functional entity in the first mobile communication network.

An embodiment of the present invention provides a user terminal, including: a terminal receiving module, configured to receive first session operation information forwarded by an access and mobility management functional entity, where the first session operation information is information sent by the session management functional entity after a next hop of a user terminal in routing information corresponding to a target session is changed to a predetermined target network entity in response to a migration failure reminding information for migrating the target session from a first mobile communication network to a second mobile communication network; the target session is a session established with a correspondent node through a first mobile communication network; and the terminal processing module is used for responding to the first session operation information, and continuing the target session with the communication opposite end through the target network entity under the condition of switching from the first mobile communication network to the second mobile communication network, so that the target session between the user terminal and the communication opposite end can be effectively ensured not to be interrupted under the condition that the second mobile communication network switched by the user terminal is not communicated with the target data network where the communication opposite end is located.

It is to be understood that the invention is not limited to the particular arrangements and instrumentality described in the above embodiments and shown in the drawings. For convenience and brevity of description, detailed description of a known method is omitted here, and for the specific working processes of the system, the module and the unit described above, reference may be made to corresponding processes in the foregoing method embodiments, which are not described herein again.

An embodiment of the present invention further provides an electronic device, which includes:

one or more processors;

a memory having one or more programs stored thereon, which when executed by the one or more processors, cause the one or more processors to implement the session continuation method of any one of the above;

and one or more I/O interfaces connected between the processor and the memory and configured to realize information interaction between the processor and the memory.

Wherein, the processor is a device with data processing capability, which includes but is not limited to a Central Processing Unit (CPU) and the like; memory is a device with data storage capabilities including, but not limited to, random access memory (RAM, more specifically SDRAM, DDR, etc.), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), FLASH memory (FLASH); the I/O interface (read/write interface) is connected between the processor and the memory, and can realize information interaction between the processor 901 and the memory, which includes but is not limited to a data Bus (Bus) and the like.

In some embodiments, the processor, memory, and I/O interface are interconnected by a bus, which in turn connects with other components of the computing device.

The present embodiment further provides a computer readable medium, on which a computer program is stored, where the computer program, when executed by a processor, implements any of the above-mentioned session continuation methods provided in this embodiment, and in order to avoid repeated descriptions, detailed steps of any of the above-mentioned session continuation methods are not described herein again.

The embodiment of the invention also provides a session connection system. The session connecting system includes: the system comprises a first mobile communication network, a second mobile communication network, a first data network, a second data network, a user terminal and a communication opposite terminal. The first mobile communication network may be a 5G network and the second mobile communication network may be a 4G network. The first mobile communication network comprises a session management function entity, an access and mobility management function entity and a user plane function entity. The first data network comprises a target network function entity N3IWF belonging to the first mobile communication network, and a communication opposite end is positioned in the second data network.

In the embodiment of the present invention, the detailed working manner of each device in the session continuation system is referred to the foregoing embodiment of the present invention, and is not described herein again.

Fig. 11 is a signaling diagram of another session connection method according to an embodiment of the present invention. The conversation connecting method is applied to the conversation connecting system. As shown in fig. 11, the session connection method includes:

step S1101, the UE initiates a network handover notification message to the AMF in the first mobile communication network.

The UE establishes a target session with a communication opposite end through a first mobile communication network currently. The network handover alert message includes a network identity of the second mobile communication network to which the UE is prepared to handover.

Step S1102, the AMF sends the network handover reminder to the SMF, so that the SMF initiates the target session migration to the second mobile communication network.

Step S1103, the SMF sends a target session migration request to the AMF, so that the AMF forwards the target session migration request to the second mobile communication network.

Step S1104, the AMF sends a target session migration request to the second mobile communication network, so as to migrate the target session established between the UE and the correspondent node to the second mobile communication network.

The target session migration request comprises a session identifier of a target session and an IP address of a communication opposite end.

Step S1105, the second mobile communication network identifies that the IP address of the second mobile communication network to the communication opposite terminal is not reachable, and returns migration failure reminding information of the target session migrated from the first mobile communication network to the second mobile communication network to the SMF through the AMF.

Step S1106, the SMF sends an entity query request to the AMF in response to the migration failure reminding information.

Wherein the entity query request comprises a network identification of the second mobile communication network.

Step S1107, the AMF returns the entity query result to the SMF.

In this embodiment, after receiving the entity query request sent by the SMF, the AMF determines at least one target data network from at least one data network connected to the second mobile communication network, where the target data network is a data network connected to the first mobile communication network and includes a predetermined N3 IWF; and then, generating an entity query result based on the entity identification corresponding to the preset N3IWF contained in each target data network.

Step S1108, the SMF receives the entity query result, selects a target entity identifier from at least one entity identifier included in the query result, and takes a predetermined N3IWF corresponding to the target entity identifier as a target N3IWF, and the SMF initiates a session change process to change the next hop of the UE in the routing information corresponding to the target session to the target N3 IWF.

Wherein the target N3IWF is an N3IWF for enabling the UE to access the first mobile communication network after handover to the second mobile communication network, for example, the target N3IWF is a non-third generation partnership project interworking function entity.

In this embodiment, after the SMF initiates the session change procedure, the SMF further generates the first session operation information and the second session operation information. The first session operation information is used for instructing the UE to continue the target session with the correspondent node through the target N3 IWF. The second session operation information is used for indicating the target N3IWF to cache first session data corresponding to the target session, wherein the first session data is session data sent by the correspondent node to the UE.

Step 1109, the SMF sends the target entity identification, the first session operation information and the second session operation information to the AMF.

It should be noted that, in order to avoid repeated descriptions, in this embodiment, the SMF sends the target entity identifier, the first session operation information, and the second session operation information to the AMF in the same step. It should be understood that, in the actual application process, the SMF may send the target entity identification, the first session operation information and the second session operation information to the AMF through different steps.

Step S1110, the AMF sends the second session operation information and the control information to the target N3 IWF.

Wherein the control information AMF generates information for instructing the target N3IWF to forward the user registration information to the AMF in the first mobile communication network after receiving the user registration information of the UE. The second session operation information is used for indicating the target N3IWF to cache first session data corresponding to the target session, wherein the first session data is session data sent by the correspondent node to the UE.

Step S1111, the target N3IWF caches the first session data sent by the correspondent node through the UPF.

Step S1112, the AMF forwards the target entity identity and the first session operation information to the UE.

Step S1113, when the UE is switched to the second mobile communication network, that is, when the UE is connected to the second mobile communication network, the UE establishes a tunnel connection with the target N3IWF corresponding to the target entity identifier through the second mobile communication network, and sends the user registration information to the target N3IWF through the established tunnel connection.

Step S1114, the target N3IWF receives the user registration information through the tunnel connection with the UE, and transmits the user registration information to the AMF in response to the control information.

Step S1115, the AMF receives the user registration information, and performs user registration for the UE in the first mobile communication network according to the user registration information. After the registration is completed, the AMF returns a registration success reminding message to the target N3 IWF.

Step S1116, the target N3IWF returns the registration success reminding information to the UE.

Step S1117, the target N3IWF sends the first session data to the UE through the tunnel connection, where the first session data is the session data sent by the correspondent node to the UE.

It should be noted that the first session data may be session data cached by the target N3IWF, or may be session data currently sent by the correspondent node in real time through the UPF.

Step S1118, the UE sends the second session data to the target N3IWF through the tunnel connection.

Step S1119, the target N3IWF forwards the second session data to the UPF.

Step S1120, the UPF forwards the second session data to the correspondent node.

By the session continuing method provided by the embodiment of the invention, when the UE is switched from the first mobile communication network to the second mobile communication network and the second mobile communication network switched by the UE is not communicated with the target data network where the communication opposite terminal is located, the target session between the UE and the communication opposite terminal can be effectively ensured not to be interrupted.

It will be understood by those of ordinary skill in the art that all or some of the steps of the above inventive method, systems, functional modules/units in the apparatus may be implemented as software, firmware, hardware, and suitable combinations thereof. In a hardware implementation, the division between functional modules/units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be performed by several physical components in cooperation. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). The term computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, as is well known to those of ordinary skill in the art. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, Digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer. In addition, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media as known to those skilled in the art.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

Those skilled in the art will appreciate that although some embodiments described herein include some features included in other embodiments instead of others, combinations of features of different embodiments are meant to be within the scope of the embodiments and form different embodiments.

It will be understood that the above embodiments are merely exemplary embodiments taken to illustrate the principles of the present invention, which is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and substance of the invention, and these modifications and improvements are also considered to be within the scope of the invention.

Claims

1. A session connection method applied to a session management function entity in a first mobile communication network, the method comprising:

2. The method of claim 1, wherein the changing the next hop of the user equipment in the routing information corresponding to the target session to the target network entity comprises:

3. The method of claim 2, wherein the predetermined network entity is a non-third generation partnership project interoperability function entity.

4. The method of claim 1, further comprising:

5. A session joining method applied to an access and mobility management function entity in a first mobile communication network, the method comprising:

6. The method according to claim 5, wherein before receiving the first session operation information sent by the session management function entity, the method further comprises:

7. The session splicing method according to claim 6, wherein after receiving the target entity identifier returned by the session management function entity, the method further comprises:

8. A session connection method is applied to a user terminal, and the method comprises the following steps:

9. The method of claim 8, wherein the responding to the first session operation information further comprises, before continuing the target session with the correspondent through the target network entity in case of handover from the first mobile communication network to the second mobile communication network:

10. The method of claim 9, wherein the step of continuing the target session with the correspondent node through the target network entity comprises:

11. A session management function entity, comprising:

12. An access and mobility management functional entity, characterized in that the access and mobility management functional entity comprises:

13. A user terminal, characterized in that the user terminal comprises: