CN111586770A

CN111586770A - Session management method and device

Info

Publication number: CN111586770A
Application number: CN201910123108.2A
Authority: CN
Inventors: 李永翠; 余芳; 倪慧; 李岩; 陈中平; 吴义壮
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-02-19
Filing date: 2019-02-19
Publication date: 2020-08-25
Anticipated expiration: 2039-02-19
Also published as: CN111586770B

Abstract

The application relates to the technical field of wireless communication, and provides a session management method, which comprises the following steps: the method comprises the steps that a first network element receives first information from terminal equipment, wherein the first information is used for establishing a session for the terminal equipment, and the first network element is configured with an incidence relation between the first information and redundant information; and the first network element determines redundant information according to the first information and the incidence relation, wherein the redundant information is used for indicating that the session is a first redundant session in which the user plane is connected through the main base station or a second redundant session in which the user plane is connected through the auxiliary base station. Wherein the first redundant session is served by a first session management network element and the second redundant session is served by a second session management network element. By the scheme provided by the embodiment, in the dual-connection communication architecture, when two redundant sessions established by the terminal equipment are served by different session management network elements, the mutual independence of the user plane connections of the two redundant sessions can be realized, so that the high-reliability transmission from the terminal equipment to the data network is realized.

Description

Session management method and device

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a method and an apparatus for session management.

Background

The 5th-Generation (5G) communication era will have billions of internet-of-things devices accessing the network, and the demands of different types of application scenarios on the network are different. The third generation partnership project (3 GPP) organization defines three major application scenarios of 5G: enhanced Mobile Broadband (eMBB), large-scale internet of things (mtc), ultra-Reliable and Low latency communications (URLLC). The URLLC is characterized by high reliability, low delay, and extremely high availability, and includes the following various scenarios and applications: industrial applications and controls, traffic safety and controls, remote manufacturing, remote training, remote surgery, and the like.

In the prior art, for the URLLC service of a terminal device, a Dual Connectivity (DC) architecture may be used to enable the terminal device (which may also be referred to as a User Equipment (UE)) to establish two sessions, so as to implement end-to-end high-reliability transmission between the UE and a Data Network (DN). As shown in fig. 1, the DC architecture includes two base stations: a master base station (master RAN, M-RAN) and a secondary base station (secondary RAN, S-RAN). In the DC architecture, the user plane connection corresponding to the first session between the UE and the DN is: UE, an M-RAN, a first User Plane Function (UPF) network element and a DN; the user plane connection corresponding to the second session between the UE and the DN is: UE, S-RAN, a second UPF network element and DN. The two sessions transmit the same service packet, which may be referred to as a first redundant session and a second redundant session, respectively.

In the DC architecture of fig. 1, since both the first redundant session and the second redundant session are served by the same Session Management Function (SMF) network element (i.e., the first SMF network element), when the UE establishes a session, the first SMF network element may determine whether the session is the first redundant session or the second redundant session. Specifically, the first SMF network element may determine, according to session information carried by the UE, that if there is no correspondence between the session information and other session identifiers on the first SMF, the first SMF determines that the session is a first redundant session, that is, the user plane of the session is connected through the M-RAN; if the first SMF has the corresponding relation between the session information and other session identifiers, the first SMF judges that the session is a second redundant session, namely the user plane of the session is connected through the S-RAN.

However, in the DC architecture as shown in fig. 2, the first and second redundant sessions are served by different SMF network elements (as in fig. 2, the first redundant session is served by a first SMF network element and the second redundant session is served by a second SMF network element). When the UE establishes a session, since there is no interaction between the first SMF network element and the second SMF network element, the SMF network element (the first SMF network element or the second SMF network element) that manages the session cannot correctly determine whether the session is a first redundant session or a second redundant session.

For example, assume that the UE has established a first redundant session whose user plane connection traverses: UE, M-RAN, a first UPF network element and DN. When the UE establishes a session through the second SMF network element, since there is no interaction between the second SMF network element and the first SMF network element, the second SMF network element considers that the session currently established by the UE is the first redundant session, and the user plane connection corresponding to the current session passes through: UE, M-RAN, a second UPF network element and DN. In this case, the user plane connections of both sessions between the UE and the DN go through the M-RAN, and thus the requirement for highly reliable transmission cannot be guaranteed.

Disclosure of Invention

The embodiment of the invention provides a method and a device for session management.

In one aspect, an embodiment of the present application provides a session management method, where the method includes:

the method comprises the steps that a first network element receives first information from a terminal device, wherein the first information is used for establishing a session for the terminal device (for example, UE), and the first network element is configured with an incidence relation between the first information and redundant information; the first network element determines redundancy information according to the first information and the association relationship, wherein the redundancy information is used for indicating that the session is a first redundancy session of the user plane connection passing through a main base station (for example, M-RAN) or a second redundancy session of the user plane connection passing through a secondary base station (for example, S-RAN), the first redundancy session is served by a first session management network element, and the second redundancy session is served by a second session management network element.

According to the method, when two redundant sessions established by the UE are served by different session management network elements, the user plane connections of the two redundant sessions can be respectively passed through the M-RAN and the S-RAN, so that high-reliability transmission from the UE to the DN is realized.

In one possible design, the first information includes at least one of a Data Network Name (DNN) or single network slice selection assistance information (S-NSSAI).

In one possible design, the first network element is a first session management network element (e.g., a first SMF), a second session management network element (e.g., a second SMF), a unified data management network element (e.g., a UDM), or an access and mobility management network element (e.g., an AMF).

In one possible design, the first network element sends redundant information to a radio access device (e.g., RAN). Thus, the RAN can determine, based on the redundant information, whether the user plane connection corresponding to the session passes through the primary base station or the user plane connection passes through the secondary base station.

In one possible design, the redundant information includes a redundant sequence number (e.g., RSN).

In another aspect, the present application also discloses a method for session management, which includes:

the method comprises the steps that a first network element receives first information from a terminal device (for example, UE), wherein the first information is used for establishing a first redundant session for the service of the terminal device, the first network element is configured with an association relationship between the first information and second information, the second information is used for establishing a second redundant session for the service, the first redundant session is served by a first session management network element (for example, a first SMF), and the second redundant session is served by a second session management network element (for example, a second SMF); and the first network element determines that the user plane connection corresponding to the first redundant session passes through the main base station (for example, M-RAN) or the user plane connection passes through the secondary base station (for example, S-RAN) according to the first information and the association relation.

According to the method, when two redundant sessions established by the UE are served by different session management network elements, the association relationship between the second information and the third information is configured in the first network element, so that the user plane connection corresponding to the first redundant session can be determined to pass through the main base station or the user plane connection and pass through the auxiliary base station. By enabling the user plane connections of the two redundant sessions to pass through the M-RAN and the S-RAN respectively, high-reliability transmission from the UE to the DN is achieved.

In one possible design, the determining, by the first network element according to the first information and the association relationship, that the user plane corresponding to the first redundant session passes through the primary base station or the user plane passes through the secondary base station includes: the first network element acquires a session identifier of a second redundant session associated with the second information according to the first information and the association relation, and the first network element determines that a user plane corresponding to the first redundant session is connected through the auxiliary base station; or the first network element determines that the session identifier of the second redundant session associated with the second information does not exist according to the first information and the association relation, and the first network element determines that the user plane corresponding to the first redundant session passes through the main base station. Therefore, by configuring the association relationship between the second information and the third information in the first network element, the first network element can determine whether the session identifier of the second redundant session associated with the third information exists, and further determine that the user plane corresponding to the first redundant session passes through the primary base station or the user plane passes through the secondary base station.

In a possible design, the obtaining, by the first network element, a session identifier of a second redundant session associated with the second information according to the first information and the association relationship includes: the first network element determines second information according to the first information and the incidence relation; the first network element sends the first information and the second information to a unified data management network element (e.g., UDM); the first network element receives a session identification for the second redundant session from the unified data management network element. Thereby, the first session managing network element may obtain the session identification of the second redundant session associated with the second information.

In a possible design, the determining, by the first network element, that the session identifier of the second redundant session does not exist and is associated with the second information according to the first information and the association relationship includes: the first network element determines second information according to the first information and the incidence relation; the first network element sends first information and second information to the unified data management network element; the first network element receives indication information from the unified data management network element; and the first network element determines that the session identifier does not exist according to the indication information. Thereby, the first network element may determine that there is no session identity of the second redundant session associated with the second information.

In one possible design, the obtaining, by the first network element, a session identifier of a second redundant session associated with second information according to the first information and the association relationship includes: the first network element determines second information according to the first information and the incidence relation; and the first network element acquires the session identifier according to the corresponding relation between the second information stored in the first network element and the session identifier.

In one possible design, the first information includes at least one of a service-corresponding first data network name (e.g., a first DNN) or service-corresponding first single-network-slice selection assistance information (e.g., a first S-NSSAI), and the second information includes at least one of a service-corresponding second data network name (e.g., a second DNN) or service-corresponding second single-network-slice selection assistance information (e.g., a second S-NSSAI). In this way,

a first network element receives first information from a terminal device (for example, a UE), wherein the first information is used to establish a first redundant session for a service of the terminal device, and the first network element is configured with an association relationship between the first information and second information, and the second information is used to establish a second redundant session for the service, the first redundant session is served by a first session management network element, and the second redundant session is served by a second session management network element; the first network element acquires a session identifier of a second redundant session associated with the second information according to the first information and the association relation; and the first network element sends a session identifier to the first session management network element, wherein the session identifier is used for determining redundant information, and the redundant information is used for indicating that the user plane corresponding to the first redundant session is connected through the auxiliary base station.

According to the method, the first network element determines whether a session identifier of a second redundant session associated with the third information exists according to the acquired association relationship between the second information and the third information, and sends the session identifier to the session management network element, and the session management network element determines that the user plane connection corresponding to the first redundant session passes through the main base station or the user plane connection passes through the auxiliary base station.

in one possible design, the first network element is a unified data management network element or an access and mobility management network element.

In another aspect, an embodiment of the present application provides an apparatus for session management, where the apparatus has a function of implementing a behavior of a first network element (e.g., the first network element in fig. 4, the SMF in fig. 5, the UDM in fig. 6, and the AMF in fig. 7) in the foregoing method. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions. In one possible design, the structure of the apparatus includes a processor and a transceiver, and the processor is configured to process the apparatus to perform the corresponding functions of the method. The transceiver is used for realizing the communication between the device and the terminal equipment/wireless access equipment. The apparatus may also include a memory, coupled to the processor, that retains program instructions and data necessary for the apparatus.

In still another aspect, an embodiment of the present application provides an apparatus for session management, where the apparatus has a function of implementing a behavior of a first network element (e.g., an SMF in fig. 8, a UDM in fig. 9, and an AMF in fig. 10) in the foregoing method. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions. In one possible design, the structure of the apparatus includes a processor and a transceiver, and the processor is configured to process the apparatus to perform the corresponding functions of the method. The transceiver is used for realizing the communication between the device and the terminal equipment/unified data management network element. The apparatus may also include a memory, coupled to the processor, that retains program instructions and data necessary for the apparatus.

In still another aspect, an embodiment of the present application provides an apparatus for session management, where the apparatus has a function of implementing a behavior of a first network element (e.g., UDM in fig. 9, AMF in fig. 10) in the foregoing method. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions. In one possible design, the structure of the apparatus includes a processor and a transceiver, and the processor is configured to process the apparatus to perform the corresponding functions of the method. The transceiver is used for realizing the communication between the device and the terminal equipment/the first session management network element. The apparatus may also include a memory, coupled to the processor, that retains program instructions and data necessary for the apparatus.

In yet another aspect, the present application provides a computer-readable storage medium having stored therein instructions, which when executed on a computer, cause the computer to perform the method of the above aspects.

In yet another aspect, the present application provides a computer program product containing instructions which, when executed on a computer, cause the computer to perform the method of the above aspects.

In yet another aspect, the present application provides a chip system, which includes a processor, for enabling the apparatus or the terminal device to implement the functions referred to in the above aspects, for example, to generate or process the information referred to in the above methods. In one possible design, the system-on-chip further includes a memory for storing program instructions and data necessary for the data transmission device. The chip system may be constituted by a chip, or may include a chip and other discrete devices.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the embodiments or background of the present invention will be described below.

FIG. 1 is a schematic diagram of a first DC architecture;

FIG. 2 is a schematic diagram of a second DC architecture;

fig. 3 is a schematic diagram of a 5G communication system provided in an embodiment of the present application;

fig. 4 is a method for session management according to an embodiment of the present application;

fig. 5 is a flowchart of another session management method provided in accordance with an embodiment of the present application;

fig. 6 is a flowchart of another session management method provided in accordance with an embodiment of the present application;

fig. 7 is a flowchart of another session management method according to an embodiment of the present application;

fig. 8 is a flowchart of another session management method according to an embodiment of the present application;

fig. 9 is a flowchart of another session management method according to an embodiment of the present application;

fig. 10 is a flowchart of a further session management method according to an embodiment of the present application;

fig. 11 is a flowchart of another session management method according to an embodiment of the present application;

fig. 12 is a flowchart of a further session management method according to an embodiment of the present application;

fig. 13A and 13B are schematic structural diagrams of an apparatus for session management provided in an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application. In the description of the present application, "/" indicates an OR meaning, for example, A/B may indicate A or B; in the present application, "and/or" is only an association relationship describing an associated object, and means that there may be three relationships, for example, a and/or B, and may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the present application, "a plurality" means two or more.

Fig. 3 shows a schematic diagram of a 5G communication system provided in an embodiment of the present application. In the 5G mobile network architecture, the control plane function and the forwarding plane function of the mobile gateway are decoupled, and the separated control plane function is merged with a Mobility Management Entity (MME) of a 3GPP conventional control network element into a unified control plane (control plane). The UPF network element can implement user plane functions (SGW-U and PGW-U) of a Serving Gateway (SGW) and a packet data network gateway (PGW). Further, the unified control plane network element may be decomposed into an access and mobility management function (AMF) network element and an SMF network element.

As shown in fig. 3, the communication system includes at least a UE 301, an AMF network element 302, a first SMF network element 303, a second SMF network element 304, a Unified Data Management (UDM) network element 305, an M-RAN device 306, an S-RAN device 307, a first UPF network element 308, a second UPF network element 309, and a DN 310.

The UE 301 involved in the present system is not limited to the 5G network, and includes: the system comprises a mobile phone, an internet of things device, an intelligent household device, an industrial control device, a vehicle device and the like. The UE may also be referred to as a Mobile Station (Mobile Station), a Mobile Station (Mobile), a Remote Station (Remote Station), a Remote Terminal (Remote Terminal), an access Terminal (access Terminal), a Terminal device (User Terminal), and a User Agent (User Agent), which are not limited herein. The terminal device may be an automobile in Vehicle-to-Vehicle (V2V) communication, a device in device communication, or the like.

The AMF network element 302 involved in the system may be responsible for registration of terminal equipment, mobility management, tracking area update procedures, and the like. The AMF network element may also be referred to as an AMF device or an AMF entity.

The first and second

SMF network elements

303, 304 involved in the present system may be responsible for session management of the terminal device. For example, session management includes selection of a user plane device, reselection of the user plane device, network protocol (IP) address allocation, quality of service (QoS) control, and establishment, modification, or release of a session. An SMF network element may also be referred to as an SMF device or an SMF entity.

The UDM network element 305 involved in the present system is capable of storing subscription data for the user. For example, the subscription data of the user includes subscription data related to mobility management and subscription data related to session management. The UDM network element may also be referred to as a UDM device or a UDM entity.

The M-RAN device 306 and S-RAN device 307 devices involved in the present system are a means for providing wireless communication functions for the UE 301, and may include various forms of base stations, such as: macro base stations, micro base stations (also referred to as small stations), relay stations, access points, etc. In systems using different radio access technologies, names of devices having a base station function may be different, for example, in an LTE system, the device is called an evolved node B (eNB or eNodeB), and in a third generation (3G) system, the device is called a node B (node B). In a new generation system, called gnb (gnnodeb).

The first UPF network element 308 and the second UPF network element 309 involved in the system can implement functions of forwarding, counting, detecting, and the like of user messages. A UPF network element may also be referred to as a UPF device or UPF entity.

DN310, as referred to in the present system, may be an operator provided service, an internet access service, or a third party provided service.

In the 5G communication system shown in fig. 3, UE 301 may establish a first redundant session through signaling interaction between M-RAN 306, AMF 302, and first SMF303, and establish a second redundant session through signaling interaction between M-RAN 306, AMF 302, and second SMF 304, so that high-reliability transmission between UE 301 and DN310 is achieved through the two redundant sessions under the DC architecture. The user plane connection corresponding to the first redundant session is as follows: UE 301, M-RAN 306, first UPF network element 308, and DN 310; the user plane connection corresponding to the second redundant session is: UE 301, S-RAN 307, second UPF network element 309, DN 310.

The network elements may be network elements implemented on dedicated hardware, or may be software instances running on dedicated hardware, or may be instances of virtualized functions on a suitable platform, for example, the virtualized platform may be a cloud platform.

In addition, the embodiment of the application can also be applied to other communication technologies facing the future. The network architecture and the service scenario described in this application are for more clearly illustrating the technical solution of this application, and do not constitute a limitation to the technical solution provided in this application, and it can be known by those skilled in the art that the technical solution provided in this application is also applicable to similar technical problems along with the evolution of the network architecture and the appearance of new service scenarios.

The following takes the 5G communication system shown in fig. 2 as an example, and the technical solution of the present application is described in detail through some embodiments. The following several embodiments may be combined with each other and may not be described in detail in some embodiments for the same or similar concepts or processes.

Fig. 4 is a method for session management according to an embodiment of the present application, where the method may be applied to the 5G communication system shown in fig. 3. By the method, the user plane connections of two redundant sessions can be independent from each other in the DC architecture shown in FIG. 3, thereby realizing high-reliability transmission from the UE to the DN. As shown in fig. 4, the method may include:

s401, the first network element receives first information from the terminal equipment. The first information is used for establishing a session for the terminal equipment, and the first network element is configured with an association relationship between the first information and the redundant information.

For example, the first Information includes at least one of a Data Network Name (DNN) or Single Network Slice Selection Assistance Information (S-NSSAI). Wherein S-NSSAI is used to identify the network slice. For example, the network slice supports URLLC traffic.

For example, the first information is used for establishing a session related to URLLC service for the terminal device.

It should be noted that when the terminal device establishes the first redundant session and the second redundant session corresponding to the same URLLC service, the carried first information is different. For example, when the terminal device establishes the first redundant session, the carried first information includes DNN-a/S-NSSAI-a; when the terminal equipment establishes the second redundant session, the carried first information comprises DNN-b/S-NSSAI-b.

For example, the first network element is the first SMF network element, the second SMF network element, the UDM network element, or the AMF network element in fig. 1.

For example, the Redundancy information includes a Redundancy Sequence Number (RSN). For example, RSN takes the value 1 or 2. It should be noted that, in this embodiment, only the RSN value is described as 1 or 2, and the RSN value may also be other values.

For example, the association relationship between the first information and the redundant information configured by the first network element is as follows: as shown in table 1, when the first information is DNN-a/S-NSSAI-a, the RSN value associated with the first information is 1; and when the first information is DNN-b/S-NSSAI-b, the RSN value associated with the first information is 2.

TABLE 1 Association relationship of first information and redundant information

First information	Redundant information
		DNN-a/S-NSSAI-a	RSN＝1
DNN-b/S-NSSAI-b	RSN＝2

S402, the first network element determines redundant information according to the first information and the incidence relation. The redundancy information is used to indicate whether the session is a first redundancy session in which the user plane connection passes through a primary base station (M-RAN) or a second redundancy session in which the user plane connection passes through a secondary base station (S-RAN). Wherein the first redundant session is served by a first session managing network element (first SMF network element) and the second redundant session is served by a second session managing network element (second SMF network element).

Wherein the redundancy information having the first value is used to indicate that the session is a first redundancy session of a user plane connection through a master base station (M-RAN). The redundancy information having a second value is used to indicate that the session is a second redundant session of the user plane connection via a secondary base station (S-RAN). Wherein the control plane functions of both user plane connections are performed by the master base station.

Further, the association of the above configuration may be understood as: the redundant information having the first value already defines that the user plane connection corresponding to the session is via the primary base station. Even if the redundant information corresponding to the first information requested by the UE first has the second value, the first network element determines that the user plane connection requested to be established first passes through the secondary base station, and the redundant information corresponding to the first information requested by the UE later has the first value, so that the user plane connection requested to be established later passes through the primary base station. Regardless of whether the secondary base station or the main base station is previously determined, the control plane function is performed by the main base station.

For example, the redundant information includes the RSN. When the RSN value is 1, the RSN indicates that the session currently established by the UE is the first redundant session, that is, the user plane corresponding to the session currently established by the UE is connected through the M-RAN; when the RSN value is 2, the RSN indicates that the session currently established by the UE is the second redundant session, that is, the user plane corresponding to the session currently established by the UE is connected through the S-RAN.

For example, if the first information received by the first network element from the UE in step S401 is DNN-a/S-NSSAI-a, and the first network element determines that the RSN value is 1 according to the first information and the association relationship in table 1, the currently established session is a first redundant session in which the user plane connection passes through the M-RAN. If the first information received by the first network element from the UE in step S401 is DNN-b/S-NSSAI-b, and the first network element determines that the RSN value is 2 according to the first information and the association relationship in table 1, the currently established session is a second redundant session in which the user plane is connected through the S-RAN.

According to the method of the embodiment of the present invention, in the scenario shown in fig. 3, when two redundant sessions established by the UE are served by different session management network elements, it can be achieved that the user plane connections of the two redundant sessions pass through the M-RAN and the S-RAN, respectively, thereby achieving high-reliability transmission between the UE and the DN.

Fig. 5 is a flowchart of another session management method according to an embodiment of the present application. The method may be used in the case where the first network element in fig. 4 is the first SMF303 or the second SMF 304 in the 5G communication system shown in fig. 3. Fig. 5 will be described in conjunction with fig. 3 and 4, and as shown in fig. 5, the method may include:

s500, the SMF network element configures the association relationship between the first information and the redundant information.

For example, the SMF network element is the first SMF303 or the second SMF 304 in fig. 3.

For example, the association relationship between the first information and the redundant information may refer to the description of the association relationship between the first information and the redundant information in step S401 of fig. 4, and is not described herein again.

S501, the UE sends a session establishment request to an AMF network element. Accordingly, the AMF network element receives a session establishment request from the terminal device.

For example, the UE is UE 301 in fig. 3, and the AMF network element is AMF network element 302 in fig. 3.

For example, the session establishment request includes the first information. The first information may refer to the description of the first information in step S401 of fig. 4, and is not described herein again.

Optionally, the session establishment request further includes a Packet Data Unit (PDU) session Identifier (ID).

S502, the AMF network element selects the SMF network element.

For example, the AMF network element selects an SMF network element for the session based on the first information (at least one of S-NSSAI or DNN) in the session establishment request.

Optionally, the AMF network element stores a correspondence between the PDU session identifier and the first information (at least one of S-NSSAI or DNN).

S503, the AMF network element sends a request for creating a session management context to the SMF network element. Accordingly, the SMF network element receives a create session management context request from the AMF network element.

For example, the create session management context request includes the first information.

For example, the AMF network element triggers the SMF network element to create a session management context for the UE by calling a create session management context Request (e.g., Nsmf _ pdusesion _ CreateSMContext Request) service.

S504, the SMF network element sends a registration request to the UDM network element, and the UDM network element sends a registration response to the SMF network element.

The UDM network element is, for example, UDM network element 305 in fig. 3.

For example, the registration request includes one or more of the following: a user permanent identifier (SUPI) of the terminal device, a DNN, a PDU session identifier, or an address of an SMF network element.

For example, the SMF network element invokes a Registration (e.g., numdm UECM Registration) service to register with the UDM network element.

Optionally, the UDM network element stores one or more of: SUPI, DNN, PDU session identity, or address of SMF network element.

It should be noted that the execution sequence of step S504 is not limited in this embodiment, that is, step S504 may be executed before step S505, or may be executed after the session establishment is completed, which is not limited in this embodiment.

And S505, the SMF network element acquires the subscription information from the UDM network element.

For example, the SMF network element obtains session management subscription information from the UDM network element by invoking a Get session management subscription information (e.g., numm SDM Get) service. The SMF network element sends a message to the UDM network element by acquiring the session management subscription information service, wherein the message comprises one or more items of the following items: SUPI, DNN or S-NSSAI.

S506, the SMF network element sends a response to create the session management context to the AMF network element. Accordingly, the AMF network element receives a create session management context response from the SMF network element.

For example, the SMF network element sends a create session management context Response (e.g., Nsmf _ pdusesion _ CreateSMContext Response) to the AMF network element by calling the create session management context Response service.

And S507, the SMF network element determines redundant information according to the first information and the incidence relation.

For example, step S507 may refer to the description of step S402 in fig. 4, and is not described herein again.

And S508, the SMF network element selects the UPF network element.

S509, the SMF network element sends an N4 session establishment request to the UPF network element, and the UPF network element sends an N4 session establishment response to the SMF network element.

For example, if the SMF network element is the first SMF303 in fig. 3, the UPF network element is the first UPF network element 308 in fig. 3. If the SMF network element is the second SMF 304 in fig. 3, the UPF network element is the second UPF network element 309 in fig. 3.

S510, the SMF network element sends an information transmission message to the AMF network element. Accordingly, the AMF network element receives the information transmission message from the SMF network element. Wherein, the information transmission message includes redundant information.

For example, the SMF network element sends redundant information to the AMF network element by invoking an information transfer (e.g., Namf _ Communication _ N1N2MessageTransfer) service.

The information transmission message includes N2 session management information (N2 SM info) and N1 session management container (N1SM container). For example, N2 SM info contains PDU session identification, S-NSSAI and redundancy information, and N2 SM info is used for SMF network elements to send to RAN equipment through AMF network elements. N1SM container includes a session establishment accept message for the SMF network element to send to the UE through the AMF network element, the RAN device.

S511, the AMF network element sends an N2 session request to the RAN. Accordingly, the RAN receives an N2 session request from the AMF network element. The N2 session request includes redundant information.

The RAN device is, for example, M-RAN 306 in fig. 3.

For example, the N2 session request includes PDU session identification, N2 SM info, and N1SM container.

S512, the RAN initiates a radio resource establishment process with the UE.

For example, the RAN device establishes radio resources by sending a non-access stratum, NAS, message to the UE. Wherein, the NAS message comprises PDU conversation identification and N1SM container.

S513, the RAN determines that the user plane corresponding to the session is connected through the main base station or the user plane is connected through the auxiliary base station according to the redundant information.

For example, in one case, if the value of the redundancy information RSN is 1, the RAN determines that the currently established session is the first redundancy session according to the RSN. That is, the user plane connection corresponding to the currently established session passes through the M-RAN. The RAN allocates a master base station tunnel information (M-RAN tunnel info) for the session. In another case, if the value of the redundancy information RSN is 2, the RAN determines that the currently established session is the second redundancy session according to the RSN. That is, the user plane connection corresponding to the currently established session passes through the S-RAN. The RAN acquires secondary base station tunnel information (S-ranging info) from the S-RAN as an M-RAN in the DC architecture shown in fig. 2.

Optionally, when the value of the redundancy information RSN is 2, if the DC architecture is not established yet (for example, the S-RAN in fig. 3 has not established a connection with the M-RAN), the RAN line triggers the DC establishment first, and then acquires the S-RAN tunnel info from the S-RAN.

S514, the RAN sends an N2 session response to the AMF network element. Accordingly, the AMF network element receives the N2 session response from the RAN.

For example, the N2 session response includes the PDU session identification and the N2 SM info. Among them, N2 SM info includes the tunnel information (i.e., M-RAN tunnel info or S-RAN tunnel info) in step S513. That is, if the currently established session is the first redundant session, M-RAN tunnel info is included in N2 SM info; if the currently established session is the second redundant session, then the S-RAN tunnel info is included in the N2 SM info.

And S515, the AMF network element sends a request for updating the session management context to the SMF network element. Accordingly, the SMF network element receives an update session management context request from the AMF network element.

For example, the AMF element invokes an update session management context Request (e.g., Nsmf _ pdusesion _ update smcontext Request) service, sending an update session management context Request to the SMF element.

For example, N2 SM info in step S514 is included in the update session management context request.

S516, the SMF network element sends an N4 session modification request to the UPF network element, and the UPF network element sends an N4 session modification response to the SMF network element.

For example, the N4 session modification request includes the tunnel information in S514 (i.e., M-RAN tunnel info or S-RAN tunnel info). And sending the tunnel information to the UPF so as to establish the downlink user interface connection between the M-RAN or S-RAN and the UPF. That is, if the tunnel information in S514 is M-RAN tunnel info, a downlink user plane connection between the M-RAN and the UPF is established; and if the tunnel information in the S514 is S-RAN tunnel info, establishing downlink user plane connection between the S-RAN and the UPF.

S517, the SMF network element sends a session management context updating response to the AMF network element. Accordingly, the AMF network element receives an update session management context response from the SMF network element.

For example, the SMF network element invokes an update session management context Response (e.g., Nsmf _ pdusesion _ update smcontext Response) service to send an update session management context Response to the AMF network element.

According to the method of the embodiment of the present invention, in the scenario shown in fig. 3, when two redundant sessions established by the UE are served by different session management network elements, it can be determined whether the currently established session is a first redundant session in which the user plane is connected through the M-RAN or a second redundant session in which the user plane is connected through the S-RAN by configuring the association relationship between the first information and the redundant information in the SMF network element. By enabling the user plane connections of the two redundant sessions to pass through the M-RAN and the S-RAN respectively, high-reliability transmission from the UE to the DN is achieved.

Fig. 6 is a flowchart of another session management method according to an embodiment of the present application. The method can be used in the case where the first network element in fig. 4 is the UDM network element 305 in the 5G communication system shown in fig. 3. Fig. 6 will be described in conjunction with fig. 3, 4 and 5, and as shown in fig. 6, the method may include:

s600, the UDM network element acquires the association relation between the first information and the redundant information.

The UDM network element is, for example, UDM network element 305 in fig. 3.

For example, there are two ways for the UDM network element to obtain the association relationship between the first information and the redundant information: the UDM network element configures an association of the first information with the redundant information, or the UDM network element receives the association of the first information with the redundant information from a Unified Data Repository (UDR).

Steps S601 to S603 can refer to the descriptions of steps S501 to S503 in fig. 5, and are not repeated here.

In the example of fig. 6, the method may further include:

s604, the SMF network element sends the first information to the UDM network element. Accordingly, the UDM network element receives the first information from the SMF network element.

For example, the first information may refer to the description of the first information in step S401 of fig. 4, and is not described herein again.

For example, the SMF network element may send the first information to the UDM network element in any one of the following two ways:

in the first way, the SMF network element sends the first information to the UDM network element through a registration request. Correspondingly, the UDM network element sends a registration response to the SMF network element. Wherein, the registration request includes one or more of the following items: SUPI, DNN, PDU session identity, or address of SMF network element of the terminal device. For example, the SMF network element invokes a Registration (e.g., numdm UECM Registration) service to register with the UDM network element.

In the second way, the SMF network element sends the first information to the UDM network element by invoking the Get session management subscription information (e.g., numm _ SDM _ Get) service. Optionally, the message sent by the SMF network element to the UDM network element by acquiring the session management subscription information service further includes the SUPI.

S605, the UDM network element determines redundant information according to the first information and the incidence relation.

For example, step S605 may refer to the description of step S402 in fig. 4, which is not repeated herein.

S606, the UDM network element sends the redundant information to the SMF network element. Accordingly, the SMF network element receives redundant information from the UDM network element.

For example, the SMF network element obtains session management subscription information and redundancy information from the UDM network element by invoking a Get session management subscription information (e.g., numm SDM Get) service.

Step S607 may refer to the description of step S506 in fig. 5, and steps S608 to S617 may refer to the descriptions of steps S508 to S517 in fig. 5, which are not repeated herein.

According to the method of the embodiment of the present invention, in the scenario shown in fig. 3, when two redundant sessions established by the UE are served by different session management network elements, it can be determined whether the currently established session is a first redundant session in which the user plane is connected through the M-RAN or a second redundant session in which the user plane is connected through the S-RAN by obtaining the association relationship between the first information and the redundant information through the UDM network element. By enabling the user plane connections of the two redundant sessions to pass through the M-RAN and the S-RAN respectively, high-reliability transmission from the UE to the DN is achieved.

Fig. 7 is a flowchart of another session management method according to an embodiment of the present application. The method may be used in the case where the first network element in fig. 4 is the AMF network element 302 in the 5G communication system shown in fig. 3. Fig. 7 will be described in conjunction with fig. 3, 4 and 5, and as shown in fig. 7, the method may include:

s700, configuring the association relationship between the first information and the redundant information by the AMF network element.

For example, the AMF network element is the AMF network element 302 in fig. 3.

Step S701 may refer to the description of step S501 in fig. 5, and is not repeated here.

In the example of fig. 7, the method may further include:

s702, the AMF network element determines redundant information according to the first information and the incidence relation.

For example, step S702 may refer to the description of step S402 in fig. 4, and is not described herein again.

And S703, the AMF network element selects the SMF network element.

For example, step S703 may refer to the description of step S502 in fig. 5, which is not repeated herein.

It should be noted that the execution order of steps S702 and S703 is not limited in this embodiment. That is, step S702 may be performed first and then S703 may be performed, or step S703 may be performed first and then S702 may be performed, or steps S703 and S702 may be performed simultaneously.

S704, the AMF network element sends a request for creating a session management context to the SMF network element. Accordingly, the SMF network element receives a create session management context request from the AMF network element.

Optionally, the request for creating the session management context includes the redundant information in step S702.

Steps S705 to S707 may refer to descriptions of steps S504 to S506 in fig. 5, and steps S708 to S709 may refer to descriptions of steps S508 to S509 in fig. 5, which are not repeated herein.

S710, the SMF network element sends an information transmission message to the AMF network element. Accordingly, the AMF network element receives the information transmission message from the SMF network element.

For example, the SMF network element sends N2 SM info and N1SM container to the AMF network element by invoking an information transfer (e.g., Namf _ Communication _ N1N2MessageTransfer) service.

For example, N2 SM info contains PDU session identification and S-NSSAI, and N2 SM info is used for SMF network element to send to RAN equipment through AMF network element. N1SM container includes a session establishment accept message for the SMF network element to send to the UE through the AMF network element, the RAN device.

S711, the AMF network element sends an N2 session request to the RAN. Accordingly, the RAN receives an N2 session request from the AMF network element.

The RAN device is, for example, M-RAN 306 in fig. 3.

It should be noted that, if the request for creating a session management context in step S704 does not include the redundant information in step S702, the request for creating a session management context in N2 also includes the redundant information in step S702.

The descriptions of steps S712 to S717 can refer to the descriptions of steps S512 to S517 in fig. 5, and are not repeated herein.

According to the method of the embodiment of the present invention, in the scenario shown in fig. 3, when two redundant sessions established by the UE are served by different session management network elements, it can be determined whether the currently established session is a first redundant session in which the user plane is connected through the M-RAN or a second redundant session in which the user plane is connected through the S-RAN by configuring the association relationship between the first information and the redundant information through the AMF. By enabling the user plane connections of the two redundant sessions to pass through the M-RAN and the S-RAN respectively, high-reliability transmission from the UE to the DN is achieved.

Fig. 8 is a flowchart of another session management method according to an embodiment of the present application. The method can be used in the 5G communication system shown in fig. 3, where the first SMF303 or the second SMF 304 determines whether a session identifier of a second redundant session associated with the third information exists according to the configured association relationship between the second information and the third information, and further determines that the user plane corresponding to the first redundant session passes through the primary base station or the secondary base station through the user plane connection. Fig. 8 will be described in conjunction with fig. 3, 4 and 5, and as shown in fig. 8, the method may include:

s800, the SMF network element configures the association relationship between the second information and the third information.

The second information is used for establishing a first redundant session for a service of the UE, and the third information is used for establishing a second redundant session for the service. For example, the service corresponding to the first redundant session and the second redundant session is URLLC service. That is, the second information and the third information are respectively used for establishing a first redundant session and a second redundant session for the same URLLC service of the UE. Wherein the first redundant session and the second redundant session are served by different SMF network elements. That is, if a first redundant session is served by a first SMF303, then a second redundant session is served by a second SMF 304; if the first redundant session is served by the second SMF 304, the first redundant session is served by the first SMF 303.

For example, the second information includes at least one of a first DNN corresponding to the service or a first S-NSSAI corresponding to the service, and the third information includes at least one of a second DNN corresponding to the service or a second S-NSSAI corresponding to the service.

For example, the association relationship between the second information and the third information configured by the SMF network element is as follows: as shown in Table 2, when the first information is DNN-a/S-NSSAI-a, the third information is DNN-b/S-NSSAI-b.

TABLE 2 Association of the second information with the third information

Second information	Third information
		DNN-a/S-NSSAI-a	DNN-b/S-NSSAI-b

Steps S801 to S804 can refer to the descriptions of steps S501 to S504 in fig. 5, and are not described herein again. Note that, the first information transmitted by the UE to the SMF through the AMF in steps S501 to S503 of fig. 5 is the second information in steps S801 to S803 of fig. 8. That is, in steps S801 to S803 in fig. 8, the UE sends the second information to the SMF through the AMF, and the description of the second information may refer to the description of the first information in step S401 in fig. 4, which is not repeated herein.

In the example of fig. 8, the method may further include:

and S805, the SMF network element determines third information according to the second information and the incidence relation.

For example, if the second information received by the SMF from the UE is DNN-a/S-NSSAI-a, the SMF network element determines that the third information is DNN-b/S-NSSAI-b according to the second information and the association shown in table 2.

S806, the SMF network element sends the second information and the third information to the UDM network element. Accordingly, the UDM network element receives the second information and the third information from the SMF network element.

For example, the SMF network element sends the second information and the third information to the UDM network element by invoking the retrieve session management subscription information (e.g., the numm _ SDM _ Get) service, and retrieves the session management subscription information corresponding to the second information from the UDM network element.

Optionally, the message sent by the SMF network element to the UDM network element by acquiring the session management subscription information service further includes the SUPI.

For example, the SMF network element carries the second information and the third information in different information elements IE1, IE2, respectively, and sends them to the UDM. Thus, the UDM can acquire the second information and the third information according to the IEs 1 and 2.

S807, the UDM network element sends the session identifier/indication information of the second redundant session to the SMF network element. Accordingly, the SMF network element receives session identification/indication information for the second redundant session from the UDM network element.

For example, step S806 includes either of the following two cases:

case 1: and if the UDM can acquire the session identifier of the second redundant session corresponding to the third information, the UDM network element sends the session identifier of the second redundant session to the SMF network element. For example, the UDM stores therein a correspondence between the session identifier of the second redundant session and the third information, or the UDM receives the session identifier of the second redundant session from the UDR.

Case 2: and if the UDM cannot acquire the session identifier of the second redundant session corresponding to the third information, the UDM network element sends indication information to the SMF network element. For example, the indication information sent by the UDM network element to the SMF network element includes any one of the following two cases: (1) the UDM sends a response message to the SMF, wherein the response message is used for indicating that the session identification of the second redundant session does not exist; (2) and the UDM sends a session identification of the second redundant session to the SMF, wherein the session identification is a null value.

And S808, the SMF network element determines that the user plane corresponding to the first redundant session passes through the main base station or the auxiliary base station.

Corresponding to the two cases of step S807, step S808 includes either of the following two cases:

case a: and if the SMF network element receives the session identifier of the second redundant session from the UDM network element, the SMF network element determines that the session currently established by the UE is the second redundant session. Therefore, the SMF network element determines that the user plane corresponding to the first redundancy session is connected through the auxiliary base station, and sets the value of the redundancy information RSN to be 2.

Case b: and if the SMF network element receives the indication information from the UDM network element, the SMF network element determines that the session currently established by the UE is the first redundant session. Therefore, the SMF network element determines that the user plane corresponding to the first redundancy session is connected through the main base station, and sets the value of the redundancy information RSN to be 1.

Step S809 may refer to the description of step S506 in fig. 5, and steps S810 to S819 may refer to the description of steps S508 to S517 in fig. 5, which are not repeated herein.

According to the method of the embodiment of the present invention, in the scenario shown in fig. 3, when two redundant sessions established by the UE are served by different session management network elements, by configuring the association relationship between the second information and the third information in the SMF network element, it can be determined whether a session identifier of the second redundant session associated with the third information exists, and it is further determined that the user plane corresponding to the first redundant session is connected through the primary base station or the user plane is connected through the secondary base station. By enabling the user plane connections of the two redundant sessions to pass through the M-RAN and the S-RAN respectively, high-reliability transmission from the UE to the DN is achieved.

Fig. 9 is a flowchart of another session management method according to an embodiment of the present application. The method can be used in the 5G communication system shown in fig. 3, where the UDM determines whether a session identifier of a second redundant session associated with the third information exists according to the obtained association relationship between the second information and the third information, and the SMF or the UDM determines that a user plane corresponding to the first redundant session is connected through the primary base station or the user plane is connected through the secondary base station. Fig. 9 will be described in conjunction with fig. 3, 4 and 8, and as shown in fig. 9, the method may include:

s900, the UDM network element acquires the association relation between the second information and the third information.

For example, the UDM stores therein the association relationship between the second information and the third information, or the UDM receives the association relationship between the second information and the third information from the UDR.

For example, the association relationship between the second information and the third information may refer to the description of the association relationship between the second information and the third information in fig. 8, and is not described herein again.

Steps S901 to S904 can refer to the descriptions of steps S801 to S804 in fig. 8, and are not repeated here.

In the example of fig. 9, the method may further include:

s905, the SMF network element sends the second information to the UDM network element. Accordingly, the UDM network element receives the second information from the SMF network element.

For example, the SMF network element sends the second information to the UDM network element by invoking the Get session management subscription information (e.g., numm SDM Get) service, and gets the session management subscription information from the UDM network element.

S906, the UDM network element determines third information according to the second information and the incidence relation.

For example, if the second information received by the UDM from the SMF is DNN-a/S-NSSAI-a, the UDM network element determines that the third information is DNN-b/S-NSSAI-b according to the second information and the association shown in table 2.

It should be noted that, in the embodiment described in fig. 9, after step S906, it may be determined by the SMF that the user plane connection corresponding to the first redundancy session passes through the primary base station or the user plane connection passes through the secondary base station (as shown in steps S907a and S908 a), or it may also be determined by the UDM that the user plane connection corresponding to the first redundancy session passes through the primary base station or the user plane connection passes through the secondary base station (as shown in steps S907b and S908 b). That is, after step S906, steps S907a-S908a may be performed, or S907b-S908b may be performed.

The steps S907a and S908a can refer to the descriptions of steps S807 to S808 in fig. 8, and are not repeated here.

S907b, the UDM network element determines that the user plane connection corresponding to the first redundant session passes through the primary base station or passes through the secondary base station.

Step S907b includes either of the following two cases:

case 1: and if the UDM can acquire the session identifier of the second redundant session corresponding to the third information, the UDM determines that the session currently established by the UE is the second redundant session. Therefore, the UDM determines that the user plane corresponding to the first redundancy session is connected through the secondary base station, and sets the value of the redundancy information RSN to 2. For example, the UDM has stored therein a session identity for the second redundant session, or the UDM receives the session identity for the second redundant session from the UDR.

Case 2: and if the UDM cannot acquire the session identifier of the second redundant session corresponding to the third information, the UDM determines that the session currently established by the UE is the first redundant session. Therefore, the UDM determines that the user plane corresponding to the first redundancy session is connected through the main base station, and sets the value of the redundancy information RSN to be 1.

S908b, the UDM network element sends the redundant information to the SMF network element. Accordingly, the SMF network element receives redundant information from the UDM network element.

Steps S909 to S919 can refer to the description of steps S809 to S819 in fig. 8, and are not described herein again.

According to the method of the embodiment of the present invention, in the scenario shown in fig. 3, when two redundant sessions established by the UE are served by different session management network elements, the UDM network element obtains the association relationship between the second information and the third information, and can determine whether a session identifier of the second redundant session associated with the third information exists, so that the SMF network element or the UDM network element determines that the user plane connection corresponding to the first redundant session passes through the primary base station or the user plane connection and passes through the secondary base station. By enabling the user plane connections of the two redundant sessions to pass through the M-RAN and the S-RAN respectively, high-reliability transmission from the UE to the DN is achieved.

Fig. 10 is a flowchart of another session management method according to an embodiment of the present application. The method can be used in the 5G communication system shown in fig. 3, where the AMF determines whether a session identifier of a second redundant session associated with the third information exists according to the configured association relationship between the second information and the third information, and the SMF or the AMF determines that a user plane connection corresponding to the first redundant session passes through the primary base station or the user plane connection passes through the secondary base station. Fig. 10 will be described in conjunction with fig. 3, 4, 5, 7 and 8, and as shown in fig. 10, the method may include:

s1000, configuring the association relationship between the second information and the third information by the AMF network element.

S1001, the UE sends a session establishment request to the AMF network element. Accordingly, the AMF network element receives a session establishment request from the terminal device.

For example, the session establishment request includes the second information. The second information may refer to the description of the first information in step S401 of fig. 4, and is not repeated here.

Optionally, the session establishment request further includes a PDU session identifier.

Step S1002 can refer to the description of step S502 in fig. 5, and is not described herein again.

It should be noted that the present embodiment does not limit the execution sequence of steps S1002 and S1003. That is, step 1002 may be executed first and then step 1003 may be executed, step 1003 may be executed first and then step 1002 may be executed, or steps S1003 and S1002 may be executed simultaneously.

And S1003, the AMF network element determines third information according to the second information and the incidence relation.

For example, if the second information received by the AMF from the UE is DNN-a/S-NSSAI-a, the AMF determines that the third information is DNN-b/S-NSSAI-b according to the second information and the association relationship shown in table 2.

It should be noted that, in the embodiment illustrated in fig. 10, after step S1003, it may be determined by the SMF that the user plane connection corresponding to the first redundant session passes through the primary base station or the user plane connection passes through the secondary base station (as shown in steps S1004a and S1005 a), or it may also be determined by the AMF that the user plane connection corresponding to the first redundant session passes through the primary base station or the user plane connection passes through the secondary base station (as shown in steps S1004b and S1005 b). That is, after the step S1003, the steps S1004a-S1005a may be performed, or the steps S1004b-S1005b may be performed.

S1004a, the AMF network element sends the session identification/indication information of the second redundant session to the SMF network element. Accordingly, the SMF network element receives session identification/indication information for the second redundant session from the AMF network element.

For example, the AMF network element sends session identification/indication information of the second redundant session to the SMF network element by calling a create session management context Request (e.g., Nsmf _ pdusesion _ CreateSMContext Request) service, and triggers the SMF network element to create a session management context for the UE.

For example, step S1004a includes either of the following two cases:

case 1: and if the session identifier of the second redundant session corresponding to the third information is stored in the AMF, the AMF network element sends the session identifier of the second redundant session to the SMF network element.

Case 2: and if the AMF cannot acquire the session identifier of the second redundant session corresponding to the third information, the AMF network element sends indication information to the SMF network element. For example, the indication information sent by the AMF network element to the SMF network element includes any one of the following two cases: (1) the message sent by the AMF to the SMF is used for indicating that the session identification of the second redundant session does not exist; (2) and the AMF sends a session identification of the second redundant session to the SMF, wherein the session identification is a null value.

Optionally, before step S1004a, the method further includes: the SMF network element determines to perform redundancy processing on the session currently established by the UE, and sends a query request to the AMF network element, wherein the query request is used for requesting session identification/indication information of a second redundant session.

Step S1005a can refer to the description of step S808 in fig. 8, and will not be described herein again.

S1004b, the AMF network element determines that the user plane corresponding to the first redundant session passes through the primary base station or passes through the secondary base station.

Step S1004b includes either of the following two cases:

case 1: and if the session identifier of the second redundant session corresponding to the third information is stored in the AMF, the AMF determines that the session currently established by the UE is the second redundant session. Therefore, the AMF determines that the user plane corresponding to the first redundancy session is connected through the auxiliary base station, and sets the value of the redundancy information RSN to be 2.

Case 2: and if the AMF cannot acquire the session identifier of the second redundant session corresponding to the third information, the AMF determines that the session currently established by the UE is the first redundant session. Therefore, the AMF determines that the user plane corresponding to the first redundancy session is connected to pass through the main base station, and sets the value of the redundancy information RSN to be 1.

S1005b, the AMF network element sends the redundant information to the SMF network element. Accordingly, the SMF network element receives the redundant information from the AMF network element.

For example, the AMF network element sends redundant information to the SMF network element by calling a create session management context Request (e.g., Nsmf _ pdusesion _ CreateSMContext Request) service, and triggers the SMF network element to create a session management context for the UE.

Steps S1006 to S1011 can refer to the descriptions of steps S705 to S710 in fig. 7, which are not repeated herein.

S1012, the AMF network element sends an N2 session request to the RAN. Accordingly, the RAN receives an N2 session request from the AMF network element.

It should be noted that, if the request for creating the session management context in the step S1005b does not include the redundant information in the step S1004b, the request for creating the session management context in the N2 further includes the redundant information in the step S1004 b.

Steps S1013 to S1018 may refer to the descriptions of steps S712 to S717 in fig. 7, and are not described herein again.

According to the method of the embodiment of the present invention, in the scenario shown in fig. 3, when two redundant sessions established by the UE are served by different session management network elements, the association relationship between the second information and the third information is configured by the AMF network element, so that it can be determined whether a session identifier of the second redundant session associated with the third information exists, and further, the SMF network element or the AMF network element determines that the user plane connection corresponding to the first redundant session passes through the primary base station or the user plane connection and passes through the secondary base station. By enabling the user plane connections of the two redundant sessions to pass through the M-RAN and the S-RAN respectively, high-reliability transmission from the UE to the DN is achieved.

In the embodiments described in fig. 8 to 10, the first network element (SMF network element, UDM network element, AMF network element) receives second information from the terminal device, where the second information is used to establish a first redundant session for a service of the terminal device, and the first network element is configured with an association relationship between the second information and third information, where the third information is used to establish a second redundant session for the service, and the first redundant session is served by the first session management network element and the second redundant session is served by the second session management network element; and the first network element determines that the user plane corresponding to the first redundant session passes through the main base station or the user plane passes through the auxiliary base station according to the second information and the association relation. The user plane connection of the first redundant session and the second redundant session respectively passes through the M-RAN and the S-RAN, so that high-reliability transmission from the UE to the DN is realized.

Fig. 11 is a flowchart of another session management method according to an embodiment of the present application. The method may be used in the 5G communication system shown in fig. 3, where the RAN determines, according to the configured association between the second information and the third information or according to the redundant information, that the user plane corresponding to the first redundant session passes through the primary base station or the user plane passes through the secondary base station. Fig. 11 will be described in conjunction with fig. 3, 4, 5 and 8, and as shown in fig. 11, the method may include:

s1100, configuring the association relationship between the second information and the third information by the RAN network element.

Steps S1101 to S1106 can refer to the descriptions of steps S501 to S506 in fig. 5, which are not repeated herein. Note that, the first information transmitted by the UE to the SMF through the AMF in steps S501 to S503 of fig. 5 is the second information in steps S1101 to S1103 of fig. 11. That is, in steps S1101 to S1103 in fig. 11, the UE sends the second information to the SMF through the AMF, and the description of the second information may refer to the description of the first information in step S401 in fig. 4, which is not described herein again.

And S1107, the SMF network element determines the redundant information.

For example, the SMF determines to perform redundancy processing on the session currently established by the UE according to the second information (at least one of DNN or S-NSSAI) received in step S1103, the subscription data acquired in step S1105, and the local policy, and sets redundancy information. The description of the redundant information may refer to the description of the redundant information in step S401, and is not repeated here.

For example, if the SMF determines that the session currently established by the UE is the first redundant session, the SMF sets RSN to 1; if the SMF judges that the session currently established by the UE is the second redundant session, the SMF sets RSN to 2.

Steps S1108 to S1109 can refer to the descriptions of steps S508 to S509 in fig. 5, and are not described herein again.

Step S1110 may refer to the description of step S510 in fig. 5. Optionally, the N2 SM info of the information transfer message further includes DNN in the second information.

Step S1111 may refer to the description of step S511 in fig. 5. Optionally, the N2 SM info of the N2 session request further includes DNN in the second information.

Step S1112 can refer to the description of step S512 in fig. 5, and is not described herein again.

It should be noted that, in the embodiment described in fig. 11, after step S1111, the RAN may determine that the user plane corresponding to the first redundancy session passes through the primary base station or the secondary base station according to the association relationship between the second information and the third information (as shown in step S1113 a), or determine that the user plane corresponding to the first redundancy session passes through the primary base station or the secondary base station according to the redundancy information (as shown in step S1113 b). That is, after step S1111, step S1113a may be performed, or S1113b may be performed. When the RAN performs S1113a, the above step S1107 may skip not performing. When the RAN performs S1113b, the above step S1100 may be skipped from being performed. In this embodiment, the execution sequence of S1113a/S1113b and S1112 is not limited. That is, S1113a/S1113b may be performed first and then S1112 may be performed, or S1113a/S1113b may be performed first and then S1112 may be performed.

S1113a, RAN determines the user interface connection corresponding to the conversation passes through the main base station or the user interface connection passes through the auxiliary base station according to the incidence relation.

For example, the RAN determines the third information according to the second information received from step S1111 and the association relationship between the second information configured in the RAN and the third information. If the RAN stores the session identifier of the second redundant session corresponding to the third information, the RAN may determine that the session currently established by the UE is the second redundant session, that is, the RAN may determine that the user plane corresponding to the session is connected to the secondary base station; if the RAN does not store the session identifier of the second redundant session corresponding to the third information, the RAN may determine that the session currently established by the UE is the first redundant session, that is, the RAN may determine that the user plane connection corresponding to the session passes through the primary base station.

S1113b, RAN determines the user interface connection corresponding to the session to pass through the main base station or the user interface connection to pass through the auxiliary base station according to the redundant information.

For example, assume that the UE establishes that the third information carried by the first redundant session and the second information carried by the second redundant session are the same. Step S1100 is an optional step. That is, if the second information is used for both establishing the first redundant session for the service of the UE and the second information is used for establishing the second redundant session for the service of the UE, the third information for establishing the second redundant session for the service does not exist, i.e., step S1100 is not performed. If the second information is used to establish a first redundant session for a service of the UE and the third information is used to establish a second redundant session for the service, step S1100 is performed. If the RAN stores the redundant information related to the second information (referred to as the first redundant information), the RAN receives the redundant information related to the second information (referred to as the second redundant information) from step S1111, and the first redundant information and the second redundant information have the same value (for example, the second redundant information RSN2 is 1 when the first redundant information RSN1 is 1, or the second redundant information RSN2 is 2 when the first redundant information RSN1 is 2), the RAN may determine that the session currently established by the UE is the second redundant session, that is, the RAN may determine that the user plane connection corresponding to the session passes through the secondary base station, and further, the RAN acquires the secondary base station tunnel information (S-RAN tunnel info) from the S-RAN. If the RAN does not store the first redundant information; alternatively, if the RAN stores the first redundant information, but the first redundant information and the second redundant information have different values (for example, the second redundant information RSN2 is 2 when the first redundant information RSN1 is 1, or the second redundant information RSN2 is 1 when the first redundant information RSN1 is 2), or the RAN does not store the first redundant information, the RAN may determine whether the session currently established by the UE passes through the primary base station or the secondary base station according to the second redundant information. For example, when the second redundancy information RSN2 is equal to 1, the user plane corresponding to the session is connected to pass through the primary base station, and when the second redundancy information RSN2 is equal to 2, the user plane corresponding to the session is connected to pass through the secondary base station. Further, the RAN acquires base station tunnel information corresponding to the user plane connection, specifically, when RSN2 is equal to 1, the M-RAN allocates a master base station tunnel information (M-RAN tunnel info) for the session, and when RSN2 is equal to 2, the M-RAN acquires a secondary base station tunnel information (S-RAN tunnel info) from the secondary base station.

Optionally, when the RAN determines that the user plane connection corresponding to the session passes through the secondary base station, if the DC architecture is not established yet (for example, the S-RAN in fig. 3 has not established a connection with the M-RAN), the RAN line first triggers DC establishment, and then acquires S-RAN tunnel info from the S-RAN.

Steps S1114 to S1117 may refer to the descriptions of steps S514 to S517 in fig. 5, and are not repeated herein.

According to the method of the embodiment of the present invention, in the scenario shown in fig. 3, when two redundant sessions established by the UE are served by different session management network elements, the RAN determines, according to the configured association relationship between the second information and the third information or according to the redundant information, that the user plane connection corresponding to the first redundant session passes through the primary base station or the user plane connection passes through the secondary base station. The user plane connections of the two redundant sessions pass through the M-RAN and the S-RAN respectively, so that high-reliability transmission from the UE to the DN is realized.

Fig. 12 is a flowchart of another session management method according to an embodiment of the present application. The method can be used in the 5G communication system shown in fig. 3, where the AMF network element selects the same SMF network element management session for sessions that need to be redundantly processed. Since it can be determined whether the currently established session is the first redundant session or the second redundant session for the same SMF network element, it can be determined that the user plane connection corresponding to the currently established session passes through the primary base station or the secondary base station. Fig. 12 will be described in conjunction with fig. 1, 3, and 10.

In the embodiment illustrated in fig. 12, before step S1208, the AMF may select the same SMF element management session according to the selection information received from the initial SMF element (as shown in steps S1200 to S1205), or according to the association relationship between the configured second information and the selection information (as shown in steps S1206 to S1207). That is, before step S1208, steps S1200 to S1205 may be performed, or steps S1206 to S1207 may be performed.

In a first possible scenario, the AMF may receive selection information from an initial SMF network element. Includes the following steps S1200 to S1205:

steps S1200 to S1201 can refer to the descriptions of steps S1000 to S1001 in fig. 10, and are not repeated here.

Step S1200 is an optional step. That is, if the second information is used for both establishing the first redundant session for the service of the UE and the second information is used for establishing the second redundant session for the service of the UE, the third information for establishing the second redundant session for the service does not exist, i.e., step S1200 is not performed. If the second information is used to establish a first redundant session for the service of the UE and the third information is used to establish a second redundant session for the service, step S1200 is executed.

S1202, the AMF network element selects an initial SMF network element.

For example, the AMF network element selects an initial SMF network element for the session based on the second information (at least one of S-NSSAI or DNN) in the session establishment request.

Optionally, the AMF network element stores a correspondence between the PDU session identifier and the second information.

S1203, the AMF network element sends a request for creating a session management context to the initial SMF network element. Accordingly, the SMF network element receives a create session management context request from the AMF network element.

For example, the second information is included in the create session management context request.

For example, the AMF network element triggers the initial SMF network element to create a session management context for the UE by calling a create session management context Request (e.g., Nsmf _ pdusesion _ CreateSMContext Request) service.

And S1204, the initial SMF network element determines to perform redundancy processing on the session.

For example, the initial SMF determines to perform redundancy processing on the session currently established by the UE according to the second information (at least one of DNN or S-NSSAI) received in step S1203 and the local policy,

and S1205, the initial SMF network element sends selection information to the AMF network element. Accordingly, the AMF network element receives selection information from the initial SMF network element.

It should be noted that the selection information can be understood as an explicit indication information, for example, the selection information is embodied in a specific cell; it can also be understood as an implicit indication, such as the selection information being embodied by other cells (e.g., DNN/S-NSAI); it may also be understood as a message.

If step S1200 is not performed, the selection information is used to instruct the AMF to select the same SMF network element for establishing the session corresponding to the second information.

If step S1200 is performed, the selection information is used to indicate that the AMF selects the same SMF network element for establishing the session corresponding to the second information or the third information.

In a second possible scenario, the AMF configures an association of the second information with the selection information. Includes the following steps S1206 to S1207:

s1206, the AMF configures the association relationship between the second information and the selection information.

For example, if the second information is used for both establishing the first redundant session for the service of the UE and establishing the second redundant session for the service of the UE, the association relationship between the second information and the selection information is shown in table 3. In table 3, when the second information is DNN-a/S-NSSAI-a, the selection information is used to instruct the AMF to select the same SMF network element for establishing the session corresponding to the second information.

TABLE 3 Association of second information with selection information

DNN-a/S-NSSAI-a

Selecting information

Optionally, if the second information is used to establish a first redundant session for a service of the UE, and the third information is used to establish a second redundant session for the service, the AMF further configures an association relationship between the second information, the third information, and the selection information. As shown in table 4, when the second information is DNN-a/S-NSSAI-a, the third information is DNN-b/S-NSSAI-b, and the selection information is used to instruct the AMF to select the same SMF network element when establishing the session corresponding to the second information or the third information.

TABLE 4 Association relationship of the second information, the third information, and the selection information

DNN-a/S-NSSAI-a

DNN-b/S-NSSAI-b

Selecting information

S1207, the UE sends a session establishment request to the AMF network element. The session establishment request includes second information (at least one of DNN or S-NSSAI). Reference may be made to the foregoing step S1000, which is not described herein again.

And S1208, the AMF network element selects the target SMF network element according to the selection information in the step S1205 or S1206.

For example, the target SMF network element may be the same as or different from the initial SMF network element.

For example, in the case that step S1200 is not performed, that is, the second information carried by the UE for establishing the first redundant session is the same as the third information carried by the UE for establishing the second redundant session: before the current session is established, the AMF stores the association relationship between the second information, the session identifier and the SMF. As shown in table 5, the second information is DNN-a/S-NSSAI-a, the session identifier corresponding to the second information is session 1, and the SMF network element corresponding to session 1 is SMF 1. When the current session is established, the second information received by the AMF network element from the UE is DNN-a/S-NSSAI-a, so the AMF selects the same SMF network element as session 1 for the current session according to the indication in step S1205. That is, the AMF network element selects the target SMF network element as SMF 1.

TABLE 5 Association of second information, session identification, and SMF

Session identification	Second information	Session-correspondent SMF
			Session 1	DNN-a/S-NSSAI-a	SMF1

For example, in the case of performing step S1200, that is, the second information carried by the UE for establishing the first redundant session is different from the third information carried by the UE for establishing the second redundant session: before the current session is established, the AMF stores the association relationship between the third information, the session identifier and the SMF. As shown in table 6, the third information is DNN-b/S-NSSAI-b, the session identifier corresponding to the third information is session 2, and the SMF network element corresponding to session 2 is SMF 2. When the current session is established, the second information received by the AMF network element from the UE is DNN-a/S-NSSAI-a, so the AMF selects the same SMF network element as session 2 for the current session according to the association relationship between the second information and the third information in table 2 and the selection information in step S1205. That is, the AMF network element selects the target SMF network element as SMF 2.

TABLE 6 Association of third information, Session identification, and SMF

Session identification	Third information	Session-correspondent SMF
			Session 2	DNN-b/S-NSSAI-b	SMF2

To this end, the AMF network element selects the same SMF network element for managing the session that needs to be redundantly processed, so that the communication system diagram in fig. 3 operates in the scenario shown in fig. 1. So when the UE establishes a session, the SMF network element can determine whether the session is a first redundant session or a second redundant session according to the prior art. If the session is a first redundant session, it may be determined that the user plane connection corresponding to the session passes through the M-RAN. If the session is a second redundant session, it may be determined that the user plane connection corresponding to the session passes through the S-RAN. The user plane connections of the two redundant sessions can be independent from each other, so that highly reliable transmission from the terminal device to the data network is realized.

In the embodiments provided in the present application, the schemes of the communication method provided in the embodiments of the present application are introduced from the perspective of each network element itself and from the perspective of interaction between each network element. It will be appreciated that the various network elements and devices, such as the above-described radio access network device, access and mobility management function network element, terminal device, data management function network element and network slice selection function network element, for implementing the above-described functions, include hardware structures and/or software modules corresponding to the implementation of the respective functions. Those of skill in the art would readily appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as hardware or combinations of hardware and computer software. Whether a function is performed as hardware or computer software drives hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

For example, when the network element implements the corresponding functions through software modules. The apparatus for session management may include a receiving module 1301, a processing module 1302, and a sending module 1303, as shown in fig. 13A.

In one embodiment, the session management apparatus may be configured to perform the operations of the first network element in fig. 4, the SMF in fig. 5, the UDM in fig. 6, and the AMF in fig. 7. For example:

a receiving module 1301, configured to receive first information from a terminal device, where the first information is used to establish a session for the terminal device, and the first network element is configured with an association relationship between the first information and redundant information. A processing module 1302, configured to determine redundant information according to the first information and the association relationship, where the redundant information is used to indicate that the session is a first redundant session in which the user plane is connected to pass through the primary base station or a second redundant session in which the user plane is connected to pass through the secondary base station, the first redundant session is served by the first session management network element, and the second redundant session is served by the second session management network element.

Therefore, in the embodiment of the invention, when two redundant sessions established by the UE are served by different session management network elements, the user plane connections of the two redundant sessions can be respectively passed through the M-RAN and the S-RAN, so that the high-reliability transmission from the UE to the DN is realized.

Optionally, the first information includes at least one of a data network name or single network slice selection assistance information.

Optionally, the session management device is a first session management network element, a second session management network element, a unified data management network element, or an access and mobility management network element.

Optionally, the apparatus further includes a sending module 1303, configured to send the redundant information to the wireless access device.

Optionally, the redundant information includes a redundant sequence number.

In addition, the receiving module 1301, the processing module 1302, and the sending module 1303 in the device for session management may further implement other operations or functions of the first network element in fig. 4, the SMF in fig. 5, the UDM in fig. 6, and the AMF in fig. 7, which are not described herein again.

In another embodiment, the apparatus for session management shown in fig. 13A may be further configured to perform the operations of the SMF in fig. 8, the UDM in fig. 9, and the AMF in fig. 10. For example:

a receiving module 1301, configured to receive first information from a terminal device, where the first information is used to establish a first redundant session for a service of the terminal device, where the first network element is configured with an association relationship between the first information and second information, the second information is used to establish a second redundant session for the service, the first redundant session is served by a first session management network element, and the second redundant session is served by a second session management network element. A processing module 1302, configured to determine, according to the first information and the association relationship, that the user plane corresponding to the first redundant session passes through the primary base station or the user plane passes through the secondary base station.

Therefore, in the embodiment of the present invention, when two redundant sessions established by the UE are served by different session management network elements, it can be determined that the user plane connection corresponding to the first redundant session passes through the primary base station or the user plane connection passes through the secondary base station by configuring the association relationship between the second information and the third information in the first network element. By enabling the user plane connections of the two redundant sessions to pass through the M-RAN and the S-RAN respectively, high-reliability transmission from the UE to the DN is achieved.

Optionally, the processing module 1302 is configured to obtain a session identifier of a second redundant session associated with second information according to the first information and the association relationship, and the processing module 1302 is configured to determine that a user plane corresponding to the first redundant session is connected to pass through the auxiliary base station; or, the processing module 1302 is configured to determine, according to the first information and the association relationship, that there is no session identifier of the second redundant session associated with the second information, and the processing module 1302 is configured to determine that the user plane corresponding to the first redundant session passes through the primary base station.

Optionally, the session management apparatus is a first session management network element, and the apparatus includes: the processing module 1302 is configured to determine second information according to the first information and the association relationship. A sending module 1303, configured to send the first information and the second information to the unified data management network element. A receiving module 1301, configured to receive a session identifier of the second redundant session from the unified data management network element.

Optionally, the session management apparatus is a first session management network element, and the apparatus includes: the processing module 1302 is configured to determine second information according to the first information and the association relationship. A sending module 1303, configured to send the first information and the second information to the unified data management network element. A receiving module 1301, configured to receive indication information from a unified data management network element; and a processing module 1302, configured to determine that the session identifier does not exist according to the indication information.

Optionally, the session management apparatus is a unified data management network element or an access and mobility management network element, and the apparatus includes: the processing module 1302 is configured to determine second information according to the first information and the association relationship. A processing module 1302, configured to obtain a session identifier according to a correspondence between the second information stored in the first network element and the session identifier.

Optionally, the first information includes at least one of a first data network name corresponding to the service or first single network slice selection auxiliary information corresponding to the service, and the second information includes at least one of a second data network name corresponding to the service or second single network slice selection auxiliary information corresponding to the service.

In addition, the receiving module 1301, the processing module 1302, and the sending module 1303 in the device for session management may also implement other operations or functions of the SMF in fig. 8, the UDM in fig. 9, and the AMF in fig. 10, which are not described herein again.

In another embodiment, the apparatus for session management shown in fig. 13A may be further configured to perform the operations of the SMF network element in fig. 9 or the UDM network element in fig. 10. For example:

a receiving module 1301, configured to receive first information from a terminal device, where the first information is used to establish a first redundant session for a service of the terminal device, where the first network element is configured with an association relationship between the first information and second information, the second information is used to establish a second redundant session for the service, the first redundant session is served by a first session management network element, and the second redundant session is served by a second session management network element. The processing module 1302 is configured to obtain a session identifier of a second redundant session associated with second information according to the first information and the association relationship. A sending module 1303, configured to send a session identifier to the first session management network element, where the session identifier is used to determine redundant information, and the redundant information is used to indicate that a user plane corresponding to the first redundant session is connected to pass through the secondary base station.

Therefore, in the embodiment of the present invention, the first network element determines whether a session identifier of the second redundant session associated with the third information exists according to the obtained association relationship between the second information and the third information, and sends the session identifier to the session management network element, and the session management network element determines that the user plane connection corresponding to the first redundant session passes through the primary base station or the user plane connection and passes through the secondary base station.

Optionally, the session management device is a unified data management network element or an access and mobility management network element.

In addition, the receiving module 1301, the processing module 1302, and the sending module 1303 in the session management apparatus may also implement other operations or functions of the UDM network element in fig. 9 or the AMF network element in fig. 10, which is not described herein again.

Fig. 13B shows another possible structural diagram of the session management apparatus involved in the above embodiment. The means for session management includes a transceiver 1304 and a processor 1305, as shown in fig. 13B. For example, the processor 1305 may be a general purpose microprocessor, a data processing circuit, an Application Specific Integrated Circuit (ASIC), or a field-programmable gate array (FPGA) circuit. The apparatus for session management may further include a memory 1306, for example, the memory is a Random Access Memory (RAM). The memory is for coupling with a processor 1305 that holds the necessary computer programs 13061 for the means of session management.

The session managing apparatus of the above embodiment further provides a carrier 1307, in which a computer program 13071 of the session managing apparatus is stored, and the computer program 13071 may be loaded into the processor 1305. The carrier may be an optical signal, an electrical signal, an electromagnetic signal, or a computer readable storage medium (e.g., a hard disk).

The

computer program

13061 or 13071, when executed on a computer (e.g., the processor 1305), may cause the computer to perform the methods described above.

For example, in one embodiment, the processor 1305 is configured for other operations or functions of a first network element (e.g., the first network element in fig. 4, the SMF in fig. 5, the UDM in fig. 6, the AMF in fig. 7). The transceiver 1304 is used to enable communication between the first network element and the terminal device/radio access device.

In another embodiment, the processor 1305 is configured for other operations or functions of the first network element (e.g., the SMF in fig. 8, the UDM in fig. 9, the AMF in fig. 10). The transceiver 1304 is used to enable communication between the first network element and the terminal device/unified data management network element.

In another embodiment, the processor 1305 is configured as other operations or functions of the first network element (e.g., UDM in fig. 9, AMF in fig. 10). The transceiver 1304 is used for enabling communication between the first network element and the terminal device/first session managing network element.

One or more of the above modules or units may be implemented in software, hardware or a combination of both. When any of the above modules or units are implemented in software, which is present as computer program instructions and stored in a memory, a processor may be used to execute the program instructions and implement the above method flows. The processor may include, but is not limited to, at least one of: various computing devices that run software, such as a Central Processing Unit (CPU), a microprocessor, a Digital Signal Processor (DSP), a Microcontroller (MCU), or an artificial intelligence processor, may each include one or more cores for executing software instructions to perform operations or processing. The processor may be built in an SoC (system on chip) or an Application Specific Integrated Circuit (ASIC), or may be a separate semiconductor chip. The processor may further include necessary hardware accelerators such as Field Programmable Gate Arrays (FPGAs), PLDs (programmable logic devices), or logic circuits for implementing dedicated logic operations, in addition to the core for executing software instructions to perform operations or processes.

When the above modules or units are implemented in hardware, the hardware may be any one or any combination of a CPU, a microprocessor, a DSP, an MCU, an artificial intelligence processor, an ASIC, an SoC, an FPGA, a PLD, a dedicated digital circuit, a hardware accelerator, or a discrete device that is not integrated, which may run necessary software or is independent of software to perform the above method flows.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the invention to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website site, computer, server, or data center to another website site, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made on the basis of the technical solutions of the present invention should be included in the scope of the present invention.

Claims

1. A method of session management, comprising:

a first network element receives first information from a terminal device, wherein the first information is used for establishing a session for the terminal device, and the first network element is configured with an incidence relation between the first information and redundant information;

the first network element determines the redundant information according to the first information and the incidence relation, the redundant information is used for indicating that the session is a first redundant session in which a user plane is connected and passes through a main base station or a second redundant session in which the user plane is connected and passes through a secondary base station, the first redundant session is served by a first session management network element, and the second redundant session is served by a second session management network element.

2. The method of claim 1, wherein the first information comprises at least one of a data network name or single network slice selection assistance information.

3. The method of claim 1 or 2, wherein the first network element is the first session management network element, the second session management network element, a unified data management network element, or an access and mobility management network element.

4. The method of any of claims 1 to 3, further comprising:

and the first network element sends the redundant information to wireless access equipment.

5. The method of any of claims 1 to 4, wherein the redundant information comprises a redundant sequence number.

6. A method of session management, comprising:

a first network element receives first information from a terminal device, wherein the first information is used for establishing a first redundant session for a service of the terminal device, the first network element is configured with an incidence relation between the first information and second information, the second information is used for establishing a second redundant session for the service, the first redundant session is served by a first session management network element, and the second redundant session is served by a second session management network element;

and the first network element determines that the user plane corresponding to the first redundant session passes through the main base station or the user plane passes through the auxiliary base station according to the first information and the association relation.

7. The method of claim 6, wherein the determining, by the first network element according to the first information and the association relationship, that the user plane corresponding to the first redundant session passes through the primary base station or the user plane passes through the secondary base station comprises:

the first network element obtains a session identifier of the second redundant session associated with the second information according to the first information and the association relationship, and the first network element determines that the user plane corresponding to the first redundant session is connected through the auxiliary base station; or the like, or, alternatively,

and the first network element determines that the session identifier of the second redundant session associated with the second information does not exist according to the first information and the association relationship, and the first network element determines that the user plane corresponding to the first redundant session passes through a master base station.

8. The method of claim 7, wherein the first network element is the first session management network element, and the obtaining, by the first network element according to the first information and the association relationship, the session identifier of the second redundant session associated with the second information comprises:

the first network element determines the second information according to the first information and the incidence relation;

the first network element sends the first information and the second information to a unified data management network element;

the first network element receives a session identification of the second redundant session from the unified data management network element.

9. The method of claim 7, wherein the first network element is the first session management network element, and the determining, by the first network element according to the first information and the association relationship, that the session identifier of the second redundant session associated with the second information does not exist includes:

the first network element receiving indication information from the unified data management network element;

and the first network element determines that the session identifier does not exist according to the indication information.

10. The method of claim 7, wherein the first network element is a unified data management network element or an access and mobility management network element, and the obtaining, by the first network element, the session identifier of the second redundant session associated with the second information according to the first information and the association relationship includes:

and the first network element acquires the session identifier according to the corresponding relationship between the second information and the session identifier stored in the first network element.

11. The method according to any of claims 6 to 10, wherein the first information comprises at least one of a first data network name corresponding to the service or first single network slice selection assistance information corresponding to the service, and the second information comprises at least one of a second data network name corresponding to the service or second single network slice selection assistance information corresponding to the service.

12. A method of session management, comprising:

the first network element acquires a session identifier of the second redundant session associated with the second information according to the first information and the association relation;

and the first network element sends the session identifier to the first session management network element, wherein the session identifier is used for determining redundant information, and the redundant information is used for indicating that the user plane corresponding to the first redundant session is connected through an auxiliary base station.

13. The method of claim 12, wherein the first information comprises at least one of a first data network name corresponding to the service or first single network slice selection assistance information corresponding to the service, and wherein the second information comprises at least one of a second data network name corresponding to the service or second single network slice selection assistance information corresponding to the service.

14. The method according to claim 12 or 13, wherein the first network element is a unified data management network element or an access and mobility management network element.

15. An apparatus for session management, comprising:

a receiving module, configured to receive first information from a terminal device, where the first information is used to establish a session for the terminal device, and the first network element is configured with an association relationship between the first information and redundant information;

and a processing module, configured to determine the redundant information according to the first information and the association relationship, where the redundant information is used to indicate that the session is a first redundant session in which a user plane is connected to pass through a master base station or a second redundant session in which the user plane is connected to pass through a secondary base station, the first redundant session is served by a first session management network element, and the second redundant session is served by a second session management network element.

16. The apparatus of claim 15, wherein the first information comprises at least one of a data network name or single network slice selection assistance information.

17. The apparatus according to claim 15 or 16, wherein the session management means is the first session management network element, the second session management network element, a unified data management network element, or an access and mobility management network element.

18. The apparatus of any one of claims 15 to 17, further comprising:

and the sending module is used for sending the redundant information to the wireless access equipment.

19. The apparatus of any of claims 15 to 18, wherein the redundant information comprises a redundant sequence number.

20. An apparatus for session management, comprising:

a receiving module, configured to receive first information from a terminal device, where the first information is used to establish a first redundant session for a service of the terminal device, where the first network element is configured with an association relationship between the first information and second information, the second information is used to establish a second redundant session for the service, the first redundant session is served by a first session management network element, and the second redundant session is served by a second session management network element;

and the processing module is used for determining that the user plane corresponding to the first redundant session passes through the main base station or the user plane passes through the auxiliary base station according to the first information and the association relation.

21. The apparatus of claim 20, comprising:

the processing module is configured to obtain a session identifier of the second redundant session associated with the second information according to the first information and the association relationship, and the processing module is configured to determine that the user plane corresponding to the first redundant session is connected through the secondary base station; or the like, or, alternatively,

the processing module is configured to determine, according to the first information and the association relationship, that there is no session identifier of the second redundant session associated with the second information, and the processing module is configured to determine that the user plane corresponding to the first redundant session passes through a master base station.

22. The apparatus of claim 21, wherein the means for session management is the first session management network element, and wherein the means for session management comprises:

the processing module is used for determining the second information according to the first information and the incidence relation;

a sending module, configured to send the first information and the second information to a unified data management network element;

the receiving module is configured to receive a session identifier of the second redundant session from the unified data management network element.

23. The apparatus of claim 21, wherein the means for session management is the first session management network element, and wherein the means for session management comprises:

the receiving module is configured to receive indication information from the unified data management network element;

and the processing module is used for determining that the session identifier does not exist according to the indication information.

24. The apparatus of claim 21, wherein the session management apparatus is a unified data management network element or an access and mobility management network element, and the apparatus comprises:

the processing module is configured to obtain the session identifier according to the correspondence between the second information stored in the first network element and the session identifier.

25. The apparatus according to any of claims 20 to 24, wherein the first information comprises at least one of a first data network name corresponding to the service or first single network slice selection assistance information corresponding to the service, and the second information comprises at least one of a second data network name corresponding to the service or second single network slice selection assistance information corresponding to the service.

26. An apparatus for session management, comprising:

the processing module is used for acquiring a session identifier of the second redundant session related to the second information according to the first information and the association relation;

a sending module, configured to send the session identifier to the first session management network element, where the session identifier is used to determine redundant information, and the redundant information is used to indicate that a user plane corresponding to the first redundant session passes through an auxiliary base station.

27. The apparatus of claim 26, wherein the first information comprises at least one of a first data network name corresponding to the service or first single network slice selection assistance information corresponding to the service, and wherein the second information comprises at least one of a second data network name corresponding to the service or second single network slice selection assistance information corresponding to the service.

28. The apparatus according to claim 26 or 27, wherein the session management apparatus is a unified data management network element or an access and mobility management network element.

29. A computer-readable storage medium comprising instructions which, when executed on a computer, cause the computer to perform the method of any one of claims 1 to 14.