WO2019158109A1 - 一种网元的选择方法及装置 - Google Patents

一种网元的选择方法及装置 Download PDF

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Publication number
WO2019158109A1
WO2019158109A1 PCT/CN2019/075073 CN2019075073W WO2019158109A1 WO 2019158109 A1 WO2019158109 A1 WO 2019158109A1 CN 2019075073 W CN2019075073 W CN 2019075073W WO 2019158109 A1 WO2019158109 A1 WO 2019158109A1
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WO
WIPO (PCT)
Prior art keywords
network element
session management
management network
user plane
base station
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PCT/CN2019/075073
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English (en)
French (fr)
Inventor
聂胜贤
周润泽
陈中平
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华为技术有限公司
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Publication of WO2019158109A1 publication Critical patent/WO2019158109A1/zh

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0011—Control or signalling for completing the hand-off for data sessions of end-to-end connection
    • H04W36/0016—Hand-off preparation specially adapted for end-to-end data sessions
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0011—Control or signalling for completing the hand-off for data sessions of end-to-end connection
    • H04W36/0033—Control or signalling for completing the hand-off for data sessions of end-to-end connection with transfer of context information
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0055—Transmission or use of information for re-establishing the radio link
    • H04W36/0066—Transmission or use of information for re-establishing the radio link of control information between different types of networks in order to establish a new radio link in the target network
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W60/00—Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/10—Connection setup
    • H04W76/12—Setup of transport tunnels

Definitions

  • the present application relates to the field of communications technologies, and in particular, to a method and an apparatus for selecting a network element.
  • the session management function (SMF) selected by the access and mobility management function (AMF) can serve the entire public land mobile network. (public land mobile network, PLMN).
  • the user plane function (UPF) managed by the SMF can simultaneously connect the base station and the data network (DN) to ensure the data connection between the user equipment (UE) and the DN.
  • the present application provides a method and device for selecting a network element to solve the problem of data service interruption.
  • the embodiment of the present application provides a method for selecting a network element, where the method includes: a first session management network element receives a first message from a mobility management network element, where the first message is used to indicate that the terminal is from a source The area is switched to the target area; the first session management network element determines whether there is a user plane network element that can establish a connection with the base station of the target area in the user plane network element managed by the first session management network element; When it is determined that there is no user plane network element that can establish a connection with the base station of the target area, the first session management network element sends a second message to the mobility management network element, where the second message is used to trigger the The mobility management network element performs an operation of selecting a second session management network element.
  • the base station corresponding to the source area is a source base station
  • the base station corresponding to the target area is a target base station.
  • the user plane selected by the first session management network element serving the source base station may only establish a connection with the DN, and may not be able to establish a connection with the target base station.
  • the mobility management network element can select another session management network element to ensure that the user plane network element in the control range of the other selected session management network element has a user plane network element that establishes a connection with the target base station, so that the UE can pass
  • the target base station establishes a connection with the DN for data transmission, and avoids data transmission interruption caused by the first session management network element of the source base station failing to serve the target base station.
  • the first message includes the target area information of the terminal, where the first session management network element determines that the user plane network element managed by the first session management network element does not exist.
  • the user plane network element that can establish a connection with the base station in the target area can be implemented as follows:
  • the service area of the surface network element it is determined that there is no user plane network element that can establish a connection with the base station of the target area in the user plane network element managed by the first session management network element.
  • the first message includes target area information of the terminal and session management information of the terminal, where the first session management network element determines that the first session management network element manages
  • the user plane network element that can establish a connection with the base station in the target area does not exist in the user plane network element, and can be implemented as follows:
  • the terminal Determining that the terminal is located in the first session management network element according to the target area information of the terminal and the service area information of one or more user plane network elements managed by the first session management network element a service area of the at least one user plane network element managed by the session management network element; the first session management network element determining, according to the session management information of the terminal, that the at least one user plane network element cannot be related to the target area Base station establishes a connection; or,
  • the first session management network element Determining, by the first session management network element, that the terminal is located in the at least one user managed by the first session management network element, according to the target area information of the terminal and the service area information of the first session management network element.
  • the first session management network element determines, according to the session management information of the terminal, that the at least one user plane network element cannot establish a connection with the base station of the target area.
  • the first session management network element determines that there is no user plane network element that can establish a connection with the base station of the target area in the user plane network element managed by the first session management network element.
  • the first session management network element determines that the first user plane network element of the base station connected to the source area cannot establish a connection with the base station of the target area, and determines that the first session management network element manages the A user plane network element other than a user plane network element cannot establish a connection with a base station of the target area.
  • the first session management network element may determine whether the first user plane network element of the base station connected to the source area can establish a connection with the base station of the target area, and the connection may be determined by the mobility management network element. Whether the first user plane network element of the base station of the source area can establish a connection with the base station of the target area.
  • the first message further includes first indication information, where the first indication information is used to indicate that the first user plane network element cannot establish a connection with a base station of the target area; the first session management network The element determines that the first user plane network element cannot establish a connection with the base station of the target area, which is specifically implemented by:
  • the first session management network element determines, according to the first indication information, that the first user plane network element cannot establish a connection with a base station of the target area.
  • the mobility management network element first determines whether the first user plane network element of the base station connected to the source area can establish a connection with the base station of the target area, if the first user plane network element can be associated with the target If the base station of the area establishes a connection, the first session management network element does not need to be triggered to make a judgment, thereby saving signaling resources.
  • the second message is used to notify the mobility management network element that there is no base station that can communicate with the target area in the user plane network element managed by the first session management network element. Establishing a connected user plane network element; or the second message includes second indication information, where the second indication information is used to indicate that the user plane network element managed by the first session management network element does not exist The base station of the target area establishes a connected user plane network element.
  • the above design provides two operations for triggering the mobility management network element to perform selection of the second session management network element.
  • the first message includes third indication information, where the third indication information is used to indicate that the mobility management network element is configured to serve the terminal by maintaining the first session management network element.
  • the operation of adding the second session management network element is performed on the basis of the third session management network element; or the third indication information is used to instruct the mobility management network element to perform an operation of reselecting the second session management network element.
  • the first session management network element determines that the mobility management network element performs an operation of adding or reselecting the second session management network element.
  • the second message includes an identifier of the first user plane network element. Based on this, after the mobility management network element selects the second session management network element according to the second message, the mobility management network element may send the identifier of the first user plane network element to the second session.
  • the network element is configured to enable the second user plane network element selected by the second session management network element to establish a connection between the base station of the target area and the first user plane network element respectively.
  • the embodiment of the present application provides a method for selecting a network element, where the method includes:
  • the mobility management network element sends a first message to the first session management network element, where the first message is used to indicate that the terminal is switched from the source area to the target area; the mobility management network element receives the first session management network element and sends the a second message, the second message is used to indicate that there is no user plane network element that can establish a connection with the base station of the target area in the user plane network element managed by the first session management network element; The management network element selects the second session management network element according to the second message, so that the second session management network element selects a user plane network element that establishes a connection with the base station of the target area.
  • the user plane selected by the first session management network element serving the source base station may only establish a connection with the DN, but may not establish a connection with the target base station.
  • the mobility management network element is notified. After receiving the notification, the mobility management network element can select another session management network element to ensure that the user plane network element in the control range of the other selected session management network element has a user plane network element that establishes a connection with the target base station. Therefore, the UE can establish a connection with the DN through the target base station to perform data transmission, thereby avoiding data transmission interruption caused by the first session management network element of the source base station failing to serve the target base station.
  • the method before the mobility management network element sends the first message to the first session management network element, the method further includes: the mobility management network element according to the first base station that connects the source area Determining, by the information of the user plane network element, that the first user plane network element cannot establish a connection with the base station of the target area; the service area information of the first user plane network element is used by the first session management network element The information about the base station accessing the source area is sent to the mobility management network element, where the information of the first user plane network element includes the service area information and/or the location of the first user plane network element.
  • An identifier of the first user plane network element where the first message sent by the mobility management network element to the first session management network element further includes first indication information, where the first indication information is used to indicate the The first user plane network element cannot establish a connection with the base station of the target area.
  • the information of the first user plane network element of the base station connected to the source area is obtained in advance by the mobility management network element, so that the first time may be determined in the process of the terminal switching from the source area to the target area. Whether the user plane network element can establish a connection with the base station of the target area, and when determining yes, it is no longer necessary to trigger the session management network element to perform the determining operation.
  • the second message is used to notify the first session management network element that the user plane network element managed by the first session management network element does not exist with the target area.
  • the base station establishes a connected user plane network element; or the second message includes second indication information, where the second indication information is used to indicate that the user plane network element managed by the first session management network element does not exist.
  • the first message includes third indication information, where the third indication information is used to indicate that the mobility management network element performs to maintain the first session management network element as the terminal. On the basis of the service, the operation of the session management network element serving the terminal is added; or the third indication information is used to instruct the mobility management network element to perform reselection of the session management network element serving the terminal. Operation.
  • the first message includes an identifier of a first user plane network element of a base station that connects the source area, and the mobility management network element selects a second session management according to the second message.
  • the method further includes: the mobility management network element sending the identifier of the first user plane network element to the second session management network element, so that the second session management network element selects The second user plane network element can respectively establish a connection between the base station of the target area and the first user plane network element.
  • the first session management network element sends the identifier of the first user plane network element of the base station connected to the source area to the mobility management network element in the first message, so that the mobility management network element sends the identifier to the mobility management network element.
  • the selected second session management network element, and the second session management network element when selecting the user plane network element connected to the target base station, selects according to the first user plane network element.
  • an embodiment of the present application provides a method for selecting a network element, where the method includes:
  • the first mobility management network element acquires the service area information of the first session management network element, where the first session management network element is configured to use the first session management network element for the terminal and the first communication Providing a service in a process of network connection; in a process in which the terminal is switched from the first communication network to the second communication network, the first mobility management network element sends a first message to the second mobility management network element
  • the first message includes the service area information of the first session management network element, so that the second mobility management network element determines whether to select according to the service area information of the first session management network element.
  • the second session management network element is configured to provide a service in the process of connecting the terminal to the second communication network.
  • the above solution provides a way of determining how to select a second session management network element during handover between base stations in different communication networks. For example, when the terminal is switched from 4G to 5G, the MME obtains the service area information of the first session management network element in the process of connecting the terminal to the 4G when the terminal accesses the 4G, so that when the terminal is switched from 4G to 5G, the MME will The service area information of the first session management network element is notified to the AMF, so that the AMF can determine whether the service area information of the first session management network element can also serve the terminal connection 5G, thereby determining whether to perform other session management selection. The operation of the network element.
  • the embodiment of the present application provides a method for selecting a network element, where the method includes: in a process in which the terminal is switched from the first communication network to the second communication network, the second mobility management network element is from the first Receiving, by the mobility management network element, the first message, where the first message includes service area information of the first session management network element, where the first session management network element is used for the terminal and the first communication network Providing a service in the process of the connection; the second mobility management network element determines whether to select the second session management network element according to the service area information of the first session management network element, where the second session management network element is used Providing a service for the terminal in connection with the second communication network.
  • the above solution provides a way of determining how to select a second session management network element during handover between base stations in different communication networks. For example, when the terminal accesses the 4G, the MME obtains the service area information of the first session management network element in the process of connecting the terminal to the 4G, so that the MME will be the first when the terminal is switched from 4G to 5G. The service area information of the session management network element is notified to the AMF, so that the AMF can determine whether the service area information of the first session management network element can also serve the terminal to connect to the 5G, and further determine whether to perform other session management network elements. Operation.
  • the first message further includes location information of the terminal, and the second mobility management network element determines whether to select the second according to the service area information of the first session management network element.
  • the session management network element includes: when determining, according to the location information of the terminal and the service area information of the first session management network element, that the terminal is not in the service area of the first session management network element, Determining, by the second mobility management network element, the second session management network element; or determining, according to the location information of the terminal and the service area information of the first session management network element, that the terminal is in the When the session management network element is in the service area, the second mobility management network element determines not to select the second session management network element.
  • the above design provides a simple and effective way for the second mobility management network element to determine whether to select the second session management network element.
  • an embodiment of the present application provides an apparatus.
  • the device may be a session management network element, or may be a chip that can be applied to a session management network element.
  • the device has the functionality to implement the various embodiments of the first aspect described above. This function can be implemented in hardware or in hardware by executing the corresponding software.
  • the hardware or software includes one or more modules corresponding to the functions described above.
  • an embodiment of the present application provides an apparatus, including: a processor and a memory; the memory is configured to store an instruction, when the device is running, the processor executes the instruction stored in the memory, so that the device performs the foregoing The method for selecting a network element in the first aspect or any implementation method of the first aspect. It should be noted that the memory may be integrated in the processor or may be independent of the processor.
  • an embodiment of the present application provides an apparatus, where the apparatus includes a processor, the processor is configured to couple with a memory, and read an instruction in the memory, and execute the first aspect or the first aspect according to the instruction.
  • an embodiment of the present application provides an apparatus.
  • the device may be a mobility management network element or a chip applied to the mobility management network element.
  • the device has the function of implementing the embodiments of the second aspect described above or the device has the function of implementing the third aspect described above or the device has the function of implementing the fourth aspect described above.
  • This function can be implemented in hardware or in hardware by executing the corresponding software.
  • the hardware or software includes one or more modules corresponding to the functions described above.
  • an embodiment of the present application provides an apparatus, including: a processor and a memory; the memory is configured to store an instruction, when the device is running, the processor executes the instruction stored in the memory, so that the device performs the foregoing
  • the method for selecting a network element in any implementation method of the second aspect or the second aspect, or the method for selecting a network element in the foregoing third aspect, or performing any of the foregoing fourth or fourth implementation methods The method of selecting the network element.
  • the memory may be integrated in the processor or may be independent of the processor.
  • an embodiment of the present application provides an apparatus, where the apparatus includes a processor, the processor is configured to couple with a memory, and read an instruction in the memory, and execute the second aspect or the second aspect according to the instruction.
  • the embodiment of the present application further provides a readable storage medium, where the readable storage medium stores a program or an instruction, and when it is run on a computer, the method for selecting any network element of the foregoing aspects is selected. Executed.
  • the embodiment of the present application further provides a computer program product comprising instructions, when executed on a computer, causing the computer to perform a selection method of any of the foregoing network elements.
  • the embodiment of the present application further provides a chip system, including: the chip system includes at least one processor, and an interface circuit, wherein the interface circuit and the at least one processor are interconnected by a line
  • the processor executes the instructions of any of the above aspects and the first aspect by running instructions.
  • the embodiment of the present application further provides a chip system, including: the chip system includes at least one processor, and an interface circuit, wherein the interface circuit and the at least one processor are interconnected by a line
  • the processor is configured to execute the method of any one of the second aspect and the second aspect, or the method of any one of the third aspect and the third aspect, or the fourth Aspects and methods of any of the fourth aspects of the design.
  • the embodiment of the present application further provides a system, where the system includes a session management network element and a mobility management network element, where the session management network element is configured to perform any of the foregoing first aspect and the first aspect.
  • the system may further include other devices that interact with the session management network element and/or the mobility management network element in the solution provided by the embodiment of the present invention, such as a user plane network element, or a terminal, and the like. .
  • the embodiment of the present application further provides a system, where the system includes a first mobility management network element of a first communication network, a second mobility management network element of a second communication network, and the first mobility
  • the management network element may be configured to perform the steps performed by the first mobility management network element in the foregoing third aspect, where the second mobility management network element may be used to perform the fourth aspect or the fourth aspect 2.
  • the steps performed by the mobility management network element may further include other devices that interact with the two mobility management network elements in the solution provided by the embodiment of the present invention, for example, a terminal, a session management network element, and the like.
  • FIGS. 1A-1C are schematic diagrams of a system architecture provided by an embodiment of the present application.
  • FIGS. 2A to 2B are schematic structural diagrams of a system in an application scenario according to an embodiment of the present disclosure
  • FIG. 3 is a flowchart of a method for selecting a network element according to an embodiment of the present disclosure
  • FIG. 4 is a schematic diagram of a method for selecting a network element according to Embodiment 1 of the present application.
  • FIG. 5 is a schematic diagram of a method for selecting a network element according to Embodiment 2 of the present application.
  • FIG. 6 is a flowchart of another method for selecting a network element according to an embodiment of the present disclosure.
  • FIG. 7 is a schematic diagram of a method for attaching a UE according to Embodiment 3 of the present application.
  • FIG. 8 is a schematic diagram of a method for selecting a network element according to Embodiment 3 of the present application.
  • FIG. 9 is a schematic structural diagram of a device according to an embodiment of the present disclosure.
  • FIG. 10 is a schematic structural diagram of a session management network element according to an embodiment of the present disclosure.
  • FIG. 11 is a schematic structural diagram of another device according to an embodiment of the present application.
  • FIG. 12 is a schematic structural diagram of a mobility management network element according to an embodiment of the present disclosure.
  • the embodiments of the present application can be applied to a 4G (fourth generation mobile communication system) evolution system, such as a long term evolution (LTE) system, or can also be a 5G (fifth generation mobile communication system) system, such as adopting a new wireless system.
  • 4G fourth generation mobile communication system
  • LTE long term evolution
  • 5G fifth generation mobile communication system
  • New RAT new radio access technology
  • CRAN Cloud Radio Access Network
  • FIG. 1A is a schematic diagram showing a system architecture applicable to an embodiment of the present application. It should be understood that the embodiment of the present application is not limited to the system shown in FIG. 1.
  • the device in FIG. 1A may be hardware, or may be functionally divided software or a combination of the two.
  • the system architecture provided by the embodiment of the present application includes a terminal, a base station, a mobility management network element, a session management network element, a user plane network element, and a data network (DN).
  • the terminal communicates with the DN through the base station and the user plane network element.
  • the base station and the mobility management network element are connected through an N2 interface.
  • the user plane network element is connected to the base station through the N3 interface.
  • the user plane NEs and the DN can be connected through the N6 interface.
  • the multiple UPFs are connected through the N9 interface.
  • the interface name is only an example. The embodiment of the present application does not specifically limit this.
  • the network element shown in FIG. 1A may be a network element in a 4G architecture or a network element in a 5G architecture.
  • a data network provides a data transmission service for a user, and may be a PDN network, such as the Internet, IP Multi-media Service (IMS), and the like.
  • IMS IP Multi-media Service
  • the mobility management network element may include an access and mobility management entity in 5G (access and mobility management). Function, AMF), or the control plane function (SGW-C) and mobility management entity (MME) of the Serving GateWay (SGW) in 4G, or the control function formed by the fusion of the Internet elements All or part of it.
  • the mobility management network element is responsible for access and mobility management of UEs in the mobile network.
  • AMF is responsible for UE access and mobility management, NAS message routing, SMF selection and so on.
  • the AMF can be used as an intermediate network element to transmit session management messages between the UE and the SMF.
  • the first mobility management network element involved in the embodiment of the present application is an MME, and the second mobility management network element involved is an AMF.
  • the mobility management network element may still be an AMF network element, or have other names, which are not limited in this application.
  • the session management network element is responsible for forwarding the path management.
  • the packet forwarding policy is sent to the user plane network element, and the user plane network element is configured to process and forward the packet according to the packet forwarding policy.
  • the session management network element may be a session management function (SMF) in the 5G, and is responsible for session management, such as session creation/modification/deletion, UPF selection, and allocation and management of user plane tunnel information.
  • SMF session management function
  • the session management network element may also be a control plane function (SGW-C) of a Serving GateWay (SGW) or a control plane function of a packet data network (PDN) gateway (GW) in the 4G ( PGW-C), the session management network element may also be all or part of the control function formed by the fusion of the SMF and the PGW-C network element.
  • the session management network element may still be an SMF network element, or have other names, which are not limited in this application.
  • the user plane network element may be a user plane function (UPF) in the 5G architecture, as shown in FIG. 1B or FIG. 1C.
  • the UPF is responsible for packet processing and forwarding.
  • the user plane network element may also be a PGW forwarding plane function (PGW-U), a SGW forwarding plane function (SGW-U), a physical or virtual forwarding device such as a router or a switch.
  • PGW-U PGW forwarding plane function
  • SGW-U SGW forwarding plane function
  • the user plane network element may still be a UPF network element, or have other names, which are not limited in this application.
  • the system architecture provided by the embodiment of the present application may further include a policy control function (PCF) or a policy and charging control function (PCRF).
  • PCF policy control function
  • PCRF policy and charging control function
  • PCF or PCRF is responsible for policy control decision and flow based charging control.
  • the system architecture may also include a subscriber data management (SDM) or a home subscriber server (HSS).
  • SDM subscriber data management
  • HSS home subscriber server
  • the user data management entity English may also correspond to User Data Management or unified data management, and the abbreviation may also correspond to UDM.
  • SDM, UDM or HSS are used to help operators achieve unified management of all user-related data.
  • the network function (NF) repository function stores information about many network elements, such as SMF information, UPF information, and AMF information.
  • Network elements such as AMF, SMF, and UPF in the network may be connected to the NRF.
  • the NE information of the network can be registered to the NRF.
  • other network elements can obtain the information of the registered NEs from the NRF.
  • the other network element (such as AMF) can obtain an optional network element by requesting the NRF according to the network element type, the data network identifier, and the unknown area information. If the domain name system (DNS) server is integrated in the NRF, the corresponding selected function network element (such as AMF) can request the NRF to obtain other network elements (such as SMF) to be selected.
  • DNS domain name system
  • a base station may also be referred to as an access node. If it is a form of radio access, it is called a radio access network (RAN), as shown in FIG. 1B. Or 1C, providing wireless access services for the terminal.
  • RAN radio access network
  • the access node may be a base station in a global system for mobile communication (GSM) system or a code division multiple access (CDMA) system, or may be a wideband code division multiple A base station (NodeB) in an access, WCDMA system may also be an evolved base station (evolutional node B, eNB or eNodeB) in an LTE system, or a base station device, a small base station device, a wireless access node (WiFi) in a 5G network.
  • GSM global system for mobile communication
  • CDMA code division multiple access
  • NodeB wideband code division multiple A base station
  • WCDMA system may also be an evolved base station (evolutional node B, eNB or eNodeB) in an LTE system, or a base station device, a small base station device, a wireless access node (WiFi) in a 5G network.
  • GSM global system for mobile communication
  • CDMA code division multiple access
  • NodeB wideband code division multiple A base station
  • a terminal which may also be referred to as an access terminal, user equipment (UE), a subscriber unit, a subscriber station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent, or User device, etc.
  • the UE is taken as an example in FIG. 1B and FIG. 1C.
  • the terminal can be a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), and a wireless communication function.
  • SIP session initiation protocol
  • WLL wireless local loop
  • PDA personal digital assistant
  • the system architecture may also include a network application function (AF).
  • AF mainly performs dynamic policy/billing control on forwarding plane behavior. These services require dynamic policy and charging control.
  • the AF transmits the dynamic session information required by the PCF, and receives the IP-CAN access network (IP-CAN) specific information and the IP-CAN bearer layer event confirmation.
  • IP-CAN IP-CAN access network
  • the above functions can be either network components in a hardware device, software functions running on dedicated hardware, or virtualization functions instantiated on a platform (eg, a cloud platform).
  • the plurality of items referred to in the present application mean two or more. "and/or”, describing the association relationship of the associated objects, indicating that there may be three relationships, for example, A and/or B, which may indicate that there are three cases where A exists separately, A and B exist at the same time, and B exists separately.
  • the character "/" generally indicates that the contextual object is an "or" relationship.
  • the prior art SMF serves the entire PLMN, and thus the AMF selects the SMF by one or more of the data network name, the slice information, the subscription information, the access technology, and the like, for example, only according to the data network name (DNN).
  • DNN data network name
  • the SMF can always select a suitable UPF based on the user location information to ensure data connection with the base station.
  • some specific UPFs are deployed, and these specific UPFs are only controlled by a specific SMF.
  • the service area of the specific SMF is limited to a specific range and cannot serve the entire PLMN.
  • the AMF selects the SMF according to the information such as the DNN, and the UPF selected by the SMF can only establish a connection with the DN, and may not establish a connection with the target base station, thereby As a result, the UE cannot be connected to the DN through the target base station after the base station is switched during the mobile process, and the data transmission is interrupted.
  • the embodiment of the present application provides a method and a device for selecting a network element, which are used to solve the problem that data transmission is interrupted when an existing UE switches to a target base station. Specifically, how the AMF determines that the current SMF cannot meet the data transmission requirements, and needs to select the SMF. In addition, how the AMF selects a suitable SMF enables the UPF managed by the SMF to establish a connection with the target base station, thereby ensuring that the UE can perform data transmission between the selected UPF and the DN.
  • the method and the device are based on the same inventive concept. Since the principles of the method and the device for solving the problem are similar, the implementation of the device and the method can be referred to each other, and the repeated description is not repeated.
  • the appropriate SMF may be selected, or a new SMF may be added based on the source SMF determined by the AMF according to information such as DNN, or the AMF may reselect an SMF.
  • the AMF first selects an SMF according to information such as the DNN.
  • the SMF selects one or more UPFs to ensure that a user plane connection is established with the base station 1 and the data network.
  • a certain UPF can be connected to the base station 1 and can be connected to the DN, or one of the UPFs can be connected to the base station 1, and the other UPF can be connected to the DN.
  • the UE is handed over to the base station 2 by the base station 1, and the SMF may not be able to select one or more UPFs to ensure that the user plane connection is established with the base station 2.
  • the current SMF can select at least one UPF to connect with the DN, and the AMF can select another SMF, and the SMF selected by the AMF can select one UPF or multiple UPFs to connect with the base station 2.
  • the AMF can also re-select an SMF, and the one or more UPFs selected by the SMF can establish a connection with the DN as well as a connection with the base station 2.
  • SMF1 manages UPF1
  • SMF2 manages UPF2.
  • the SMF selected by the AMF according to the DNN is SMF2, and the UPF2 selected by SMF2 can connect both the DN and the AN1.
  • SMF2 does not serve the entire PLMN
  • UPF2 managed by SMF2 cannot establish a connection with AN2 when AN1 is switched to AN2 after the UE moves.
  • the AMF can select another SMF1, so that the UPF1 selected by SMF1 can establish a connection with UPF2 and AN2, thereby ensuring uninterrupted data transmission between the UE and the DN.
  • a connection is established between the UE and the DN.
  • Multiple SMFs are required in the network due to deployment, and multiple UPFs are selected under the control of the SMF to establish a user plane connection.
  • there may be other SMFs between SMF1 and SMF2 and there are other UPFs between UPF1 and UPF2.
  • SMF1 manages UPF1
  • SMF2 manages UPF2.
  • the SMF selected by the AMF according to the DNN is SMF2, and the UPF2 selected by SMF2 can connect both the DN and the AN1.
  • the SMF2 does not serve the entire PLMN, the UPF2 managed by the SMF2 cannot establish a connection with the AN2 when the UE moves from the service area of the AN1 to the service area of the AN2.
  • the AMF can reselect an SMF1, so that the UPF1 selected by the SMF1 can establish a connection with the DN and the AN2, thereby ensuring uninterrupted data transmission between the UE and the DN.
  • the following describes the selection scheme of the session management network element.
  • a flow chart of a method for selecting a network element is provided in the embodiment of the present application.
  • the UE moves from one area (source area) to another area (target area).
  • the corresponding base stations in the two areas are different.
  • the base station in the source area is referred to as the source base station
  • the base station in the target area is referred to as the target base station.
  • the mobility management network element sends a first message to the first session management network element, where the first message is used to indicate that the terminal is switched from the source area to the target area.
  • the first session management network element is a session management network element that is determined by the mobility management network element according to one or more of DNN, slice information, subscription information, and access technology.
  • the first message may be a handover request message, or a message indicating that the terminal is switched from the source area to the target area is applicable to the embodiment of the present application.
  • the first session management network element receives the first message from the mobility management network element.
  • the first session management network element determines whether there is a user plane network element that can establish a connection with the base station of the target area in the user plane network element managed by the first session management network element.
  • the first session management network element when it is determined that there is no user plane network element that can establish a connection with the base station of the target area, the first session management network element sends a second message to the mobility management network element, where the second The message is used to trigger the mobility management network element to perform an operation of selecting a second session management network element.
  • the second session management network element selects a user plane network element that establishes a connection with the base station of the target area.
  • the mobility management network element selects a second session management network element according to the second message, so that the second session management network element selects a user plane network element that establishes a connection with the base station of the target area.
  • the user plane selected by the first session management network element serving the source base station may only be able to establish a connection with the DN, and may not be able to establish a connection with the target base station.
  • the first session management network element serving the source base station determines whether there are user plane network elements that can establish a connection with the target base station in the multiple user plane network elements under control, and if not, notify the mobility.
  • the network element is managed, so that the mobility management network element can select another session management network element to ensure that the user plane network element in the control range of the other selected session management network element has a user plane network element that establishes a connection with the target base station. Therefore, the UE can establish a connection with the DN through the target base station to perform data transmission, thereby avoiding data transmission interruption caused by the first session management network element of the source base station failing to serve the target base station.
  • the first message may further include target area information of the terminal, such as location information of the terminal.
  • the target area information of the terminal may be the location information/identity of the base station located in the target area or the location information/identification of the target area corresponding to the target cell, and the first session management network element determines the first session management network element.
  • the user plane network element that can establish a connection with the base station of the target area in the managed user plane network element can be implemented by any of the following methods:
  • the first session management network element is configured according to target area information of the terminal and service area information of one or more user plane network elements managed by the first session management network element (or Determining, by the service information of the first session management network element, that the terminal is not in the service area of any user plane network element managed by the first session management network element, that is, determining the first session management network element There is no user plane network element in the managed user plane network element that can establish a connection with the base station in the target area.
  • the service area information may reflect service area information of one or more user plane network elements that it manages, then the first session management network element is according to the Determining that the terminal is not in the service area of any user plane network element managed by the first session management network element, that is, the target area information of the terminal and the service area information of the first session management network element, that is, determining the The user plane network element that can be connected to the base station of the target area does not exist in the user plane network element managed by the first session management network element.
  • the first session management network element is configured according to target area information of the terminal and service area information of one or more user plane network elements managed by the first session management network element (or The service area information of the first session management network element is determined to be located in a service area of at least one user plane network element (such as user plane network element A) managed by the first session management network element;
  • the first session management network element determines, according to the session management information of the terminal, that the at least one user plane network element (such as the user plane network element A) cannot establish a connection with the base station of the target area.
  • the service area information may reflect service area information of one or more user plane network elements that it manages, then the first session management network element is according to the Determining, by the target area information of the terminal, the service area information of the first session management network element, that the terminal is in a service area of any user plane network element managed by the first session management network element; The session management network element determines, according to the session management information of the terminal, that the at least one user plane network element cannot establish a connection with the base station of the target area.
  • the first session management network element attempts to select at least one UPF in the at least one user plane network element to match session management information of the terminal. If at least one UPF cannot match the session management information of the terminal, the at least one user plane network element cannot establish a connection with the base station of the target area.
  • the session management information of the terminal includes the following information: DNN, Session and Service Continuity mode (SSC mode), slice information, session type, user plane network element capability (cache, local offload, etc.), user One or more of the information such as the service area of the surface network element.
  • the session management information of the terminal may be obtained by the mobility management network element from the subscription server and sent to the first session management network element.
  • the user plane network element managed by the first session management network element includes a user plane network element A and a user plane network element B.
  • the first session management network element determines that the target area where the terminal is located is located on the user plane managed by the first session management network element.
  • the first session management network element determines whether the user plane network element A meets the session management information, and if not, determines that the user plane network element A cannot establish a connection with the base station of the target area. For example, if the user plane network element A does not meet the requirements of the SSC mode in the session management information of the terminal, it is determined that the user plane network element A cannot establish a connection with the base station of the target area.
  • the session management information of the terminal may be obtained by the first session management network element during the session creation process.
  • the SSC mode is sent by the terminal to the first session management network element during the session creation process.
  • the information of the user plane network element (cache, local offload, etc.), the service area of the user plane network element, and the like may be obtained by the subscription data of the first session management network element user.
  • the first session management network element attempts to select a user plane network element that satisfies the condition, and if it is selected, it exists, and if it is not selected, it does not exist.
  • Specific conditions may include one or more of information such as UE location, DNN, SSC mode, slice information, PDU session type, capability of the user plane network element (cache, local offload, etc.), and service area of the user plane network element. .
  • information such as UE location, DNN, SSC mode, slice information, PDU session type, capability of the user plane network element (cache, local offload, etc.), and service area of the user plane network element.
  • the existing SMF selects the UPF.
  • the first session management network element determines whether there is a user plane network element that can establish a connection with the base station of the target area in the user plane network element managed by the first session management network element. Specifically, it can be realized as follows:
  • the first session management network element may first determine whether the first user plane network element connected to the source base station can establish a connection with the target base station, and if not, determine the first session management network element management. Whether the user plane network element other than the first user plane network element can establish a connection with the target base station.
  • the user plane network element connected to the source base station and other user plane network elements are not distinguished in the user plane network element managed by the first session management network element.
  • the first session management network element may directly determine whether there is a user plane network element that can establish a connection with the target base station in one or more user plane network elements managed by the first session management network element.
  • the mobility management network element determines whether the first user plane network element connected to the source base station can establish a connection with the target base station.
  • the first session management network element After the terminal accesses the source base station, the first session management network element sends the information of the first user plane network element to the mobility management network element after selecting the first user plane network element.
  • the information of the first user plane network element includes the service area information of the first user plane network element and/or the identifier of the first user plane network element, and the service of the first user plane network element is subsequently described.
  • the area information is described as an example. Therefore, after receiving the handover request, the mobility management network element may determine, according to the target area information of the terminal and the information of the first user plane network element, whether the terminal is located in the service area of the first user plane network element, and if not, Then, the first user plane network element cannot establish a connection with the target base station.
  • the mobility management network element in the embodiment corresponding to FIG. 2 is the AMF
  • the session management network element is the SMF
  • the user plane network element is the UPF.
  • Embodiment 1 is a diagrammatic representation of Embodiment 1:
  • FIG. 4 is a schematic flowchart of a network element selection provided by an embodiment of the present application.
  • ASMF SMF
  • target AN target AN, T-AN
  • ISMF ISMF
  • the newly selected SMF the UPF connected to the DN is called AUPF (that is, the UPF corresponding to the S-AN, corresponding to the UPF2 in FIG. 2A)
  • the selected UPF connected to the T-AN is called For IUPF.
  • the S-AN sends a handover requirement to the S-AMF when determining that the UE needs to switch from the S-AN to the T-AN (target AN).
  • the handover request includes an identifier of a protocol data unit (PDU) session and a target location information (UE location) of the UE, and the target area information of the UE is also location information of the target AN or a cell ID corresponding to the target area.
  • the identifier of the PDU session may be a PDU session ID.
  • the S-AMF After receiving the handover indication, the S-AMF sends a forward relocation request to the T-AMF.
  • the forward redirect request includes an ID of the PDU session and target area information of the UE.
  • S-AMF serves S-AN and T-AMF serves T-AN.
  • the T-AMF sends a PDU handover request 1 to the ASMF, where the handover request 1 includes target area information of the UE.
  • the ASMF After receiving the handover request 1, the ASMF determines that there is no UPF that can establish a connection with the T-AN in the UPF managed by the ASMF.
  • the ASMF determines whether the UPF1 (ie, AUPF) that establishes the connection with the S-AN can establish a connection with the T-AN according to the target area information of the UE, if the ASMF triggers the process of establishing a user plane connection between the T-AN and the UPF1, that is, the ASMF An N4 session update request is sent to the UPF1.
  • the UPF1 can connect to the AN and can be connected to the S-AN and the T-AN, respectively.
  • the ASMF determines whether the UPF managed by the ASMF other than the UPF1 can establish a connection with the T-AN.
  • the ASMF determines that the UPF2 managed by the ASMF can establish a connection with the T-AN, the ASMF triggers the process of establishing a user plane connection between the T-AN and the UPF2. Specifically, the ASMF sends an N4 session update request to the UPF2 (N4). Session update).
  • the ASMF determines that the UPF managed by the ASMF cannot establish a connection with the T-AN, the UPF managed by the ASMF does not have a UPF that can establish a connection with the T-AN.
  • the ASMF sends a message 1 to the T-AMF, where the message 1 is used to trigger the T-AMF to perform an operation of selecting the SMF.
  • the message 1 may be a PDU handover response (1).
  • other messages for triggering the T-AMF to perform the operation of selecting the SMF are applicable to the embodiment of the present application. 1 is an example.
  • the ASMF judges that the result of the determination that there is no UPF that can establish a connection with the T-AN in the UPF managed by the ASMF can be sent to the T-AMF through the message 1. Thereby the T-AMF performs an operation of selecting the SMF according to the judgment structure.
  • the message 1 itself has the function of notifying the judgment result, that is, if the T-AMF is not required to perform the operation of selecting the SMF, the ASMF does not need to send the message 1 to the T-AMF, and once the message 1 is sent to the transmitting T-AMF, Then the T-AMF is triggered to perform the operation of selecting the SMF.
  • the notification result is sent in the form of a reason value in the message 1.
  • the reason value is used to indicate that the reason for transmitting the message 1 is that the UPF managed by the ASMF does not exist and can be established with the T-AN. Connected UPF.
  • the PDU switching response 1 may further carry indication information, where the indication information is used to indicate an action performed by the T-AMF.
  • Actions include: reselect SMF or add SMF.
  • the ASMF can determine the actions required to be performed by the T-AMF by:
  • the ASMF determines the actions required to be performed by the T-AMF according to the network policy, wherein the network policy may be pre-configured in the ASMF.
  • the network policy may include: performing conditions for newly satisfied conditions and performing conditions for performing reselection.
  • the service may be added to a specific session according to the service-related information. For example, if a session includes a locally-divided service, the session is added.
  • the data network access identifier (DNAI) or the service identifier or the data feature indicates the service type corresponding to the data transmitted by the UE.
  • the DNAI may be obtained during the session creation or update process, the SMF is obtained from the policy control network element, or the DNAI is pre-configured on the SMF.
  • the specific network policy may include: performing a data network access identifier (DNAI) corresponding to the action of adding an ISMF, or performing a service identification range corresponding to the action of adding an ISMF, or performing an additional ISMF.
  • DNAI data network access identifier
  • the data characteristics corresponding to the action may include: performing a data network access identifier (DNAI) corresponding to the action of adding an ISMF, or performing a service identification range corresponding to the action of adding an ISMF, or performing an additional ISMF.
  • the SSC mode information indicates that session continuity is required, then the UPF (AUPF) as an anchor cannot be changed, then an ISMF needs to be added; if session continuity is not required, the SMF and UPF can be reselected.
  • the network policy may also be pre-configured in the T-AMF, and the PDU switching response 1 may not carry the foregoing indication information for indicating an action performed by the T-AMF.
  • the actions required to be performed are determined by the T-AMF according to the network policy.
  • the T-AMF After receiving the PDU switching response 1 sent by the ASMF, the T-AMF performs an operation of adding or reselecting the SMF.
  • an operation of adding a new SMF is taken as an example.
  • the session creation or session update process is performed. For details, refer to the process of establishing or updating or modifying an existing PDU session, and details are not described herein again.
  • the T-AMF can be implemented as follows:
  • the T-AMF queries the NRF (or the DNS server) for an optional list 1 of the SMF according to the target area information of the UE (such as the identity of the cell, the location information of the base station, etc.), and obtains an SMF according to the DNN query. Pick list 2. Then, the T-AMF first selects an SMF from the optional list 2 as a session anchor or an IP anchor, which may be selected according to information such as load and capability of each SMF, for example, the selected SMF is SMF1. Then compare the SMF with the optional list 1, and preferentially select the SMF with the same identifier as the SMF1 in the optional list 1.
  • the same SMF is not identified, compare the identifier of the SMF included in the optional list 1 with the identifier of the SMF1. , select the SMF closest to the SMF1 topology.
  • the identifier of the SMF is determined according to the service area, and the closer the service areas of the two SMFs are, the closer the identifiers of the two SMFs are. Therefore, the two SMF topologies are closest, that is, the two SMFs are closest to each other.
  • the ultimate goal of selecting an SMF is to choose to UPF, where UPF can be connected to T-AN and DN, respectively.
  • the AMF selects the service area of the SMF in the process of selecting the SMF.
  • the service area of the SMF is related to the service area of the corresponding UPF. For example, if the SMF can control multiple UPFs, the service area of the SMF will be split into many In the small service area corresponding to the UPF, the SMF actually knows that the service area of the SMF also knows the service area of the UPF when selecting the UPF. Therefore, it can be guaranteed that after selecting an SMF, a UPF can be found to be able to connect with the T-AN.
  • the service area of the SMF is a collection or a union of service areas of multiple UPFs, and the SMF knows that the service area of the SMF knows that there is at least one service area of the UPF when selecting the UPF. In this range. Therefore, it can be guaranteed that after selecting an SMF, a UPF can be found to be able to connect with the T-AN.
  • the T-AMF may also send the UE location and DNN information to the DNS server (or NRF) at the same time, and the DNS server (or NRF) separately queries to obtain two selectable lists and selects the SMF, and returns the selection result to T-AMF.
  • the DNS server or NRF
  • the SMF identifier is returned; if the DNS server (or NRF) selects two SMFs, one of the SMFs satisfies the UE location The other SMF satisfies the DNN, and returns two SMFs, and indicates the role of each SMF of the AMF, that is, which T-AN is indicated, which is the ISMF, and which DN is used as the ASMF (for the connection DN).
  • the current ASMF is maintained as a session anchor or an IP anchor, which can be implemented as follows:
  • the DNN remains unchanged during the hold of the PDU session, and the ASMF can always maintain a connection with the DN. Only one more SMF is needed to ensure that the UPF connected to the T-AN can be selected.
  • the T-AMF queries the DNS server (or NRF) for an optional list 1 of the SMF according to the target area information of the UE (such as the cell identifier, the location of the base station, etc.), and then compares the ASMF with the optional list 1, and preferentially In the optional list 1, the SMF with the same identifier as the ASMF is selected. If the SMF is not identified, the SMF identifier included in the optional list 1 is compared with the identifier of the SMF1, and the SMF closest to the SMF1 topology is selected as the ISMF.
  • the DNS server or NRF
  • the T-AMF may also send the identity of the UE location and the ASMF to the DNS server (or NRF), the DNS server (or NRF) queries the optional list 1 and selects the SMF, and returns the selection result to the T- AMF.
  • the PDU switching response sent by the T-AMF to the ASMF may further include an identifier of the AUP that is connected to the S-AN. If the T-AMF determines that the ISMF needs to be newly added, after the newly added ISMF is selected, The identifier of the AUP that is connected to the S-AN may be sent to the newly added ISMF, so that the newly added ISMF may select the IUPF closest to the AUPF topology according to the identifier of the AUP when selecting the UPF.
  • an operation of adding a new SMF by using T-AMF is taken as an example.
  • the T-AMF After determining the new I-SMF, the T-AMF performs a subsequent session update process, that is, updates the user plane connection between the UE and the DN. Specifically include the following:
  • the T-AMF sends a PDU handover request (2) to the ISMF.
  • the PDU switching request 2 may include T-AN tunnel information (T-AN tunnel info), ID of the PDU session, and ASMF ID.
  • T-AN tunnel info T-AN tunnel info
  • ID of the PDU session ID of the PDU session
  • ASMF ID ASMF ID
  • the ISMF selects the IUPF, and then sends an N4 session management request 1 to the IUPF, where the N4 session management request may be an N4 session establishment/modification/update request (N4 session establishment). /modification/update request).
  • the N4 session management request may include an ID of the PDU session and a T-AN tunnel info.
  • the N4 session management request is used to indicate that the IUPF establishes a user plane connection with the T-AN.
  • the IUPF After establishing the user plane connection with the T-AN, the IUPF sends an N4 session management response 1 to the ISMF.
  • the N4 session management response 1 may be an N4 session establishment/modification/update response.
  • the N4 session management response 1 is used to indicate whether the IUPF successfully establishes a user plane connection with the T-AN.
  • the I-SMF can obtain the tunnel information of the IUGF, and can include the N3 tunnel information corresponding to the user plane connection between the IUPF and the T-AN, and can also include the N9 between the IUPF and the AUPF.
  • Tunnel information (N9 tunnel info).
  • N3 is the interface between the UPF and the AN
  • N9 is the interface between the two UPFs, such as IUPF and AUPF.
  • the N3 tunnel information and the N9 tunnel information are sent to the IUPF by the I-SMF in the N4 session management request of S408; if the tunnel information is allocated by the UPF, the Iubf is managed by the IUP in the N4 session management response of S409. The N3 tunnel information and the N9 tunnel information are sent to the I-SMF.
  • the ISMF sends a PDU handover request 3 to the ASMF, where the PDU handover request 3 includes N3 tunnel information (N3 tunnel info) and N9 tunnel information, and an ID of the PDU session.
  • the PDU switching request 3 is used to instruct the ASMF to establish a user plane connection between the IUPF and the AUPF.
  • the ASMF After receiving the PDU switching request 3 sent by the ISLF, the ASMF sends an N4 session management request 2 to the AUP.
  • the N4 session management request 2 includes an ID of the PDU session and an N9 tunnel info.
  • the N4 session management request 2 is used to indicate that the AUPF establishes a user plane connection with the IUPF.
  • the AUPF After receiving the N4 session management request 2 sent by the ASMF, the AUPF sends an N4 session management response 2 to the ASMF.
  • the N4 session management response 2 is used to indicate whether the AUPF successfully establishes a user plane connection with the IUPF.
  • the N4 session management response 2 may include the N9 tunnel info of AUPF.
  • the ASMF sends a PDU handover response 3 to the ISLF, and the PDU handover response 3 includes an N9 tunnel info of the AUPF.
  • the ISMF After receiving the PDU handover response 3 sent by the ASMF, the ISMF sends a PDU handover response 2 to the T-AMF, where the PDU handover response 2 includes the N3 tunnel info of the IUPF.
  • the T-AMF After receiving the PDU handover response 2 sent by the I-SMF, the T-AMF sends a handover request to the T-AN, and carries the N3 tunnel info of the IUPF, so that the T-AN can send the uplink data to the IUPF.
  • the T-AN After receiving the handover request sent by the T-AMF, the T-AN confirms the PDU session information that can be switched, and sends a handover response to the T-AMF.
  • the T-AMF After receiving the handover response sent by the T-AN, the T-AMF sends a modify PDU request to the I-SMF, which may include an N9 tunnel info of the AUPF.
  • the I-SMF After receiving the modification PDU request sent by the T-AMF, the I-SMF sends an N4 session management request 3 to the IUPF.
  • the N4 session modification request may include the N9 tunnel info of the AUPF, so that the IUPF can send the uplink data by the AUPF.
  • the IUPP After receiving the N4 session management request 3 sent by the I-SMF, the IUPP completes the PDU session modification, and sends an N4 session management response 4 to the I-SMF, where the N4 session management response 4 may be an N4 session modification response (N4 session modification). Response).
  • the T-AMF After receiving the modified PDU response sent by the I-SMF, the T-AMF sends a forward relocation response to the S-AMF, where the forward redirect response is used to indicate that the S-AN is successfully completed to the T-AN. Switching.
  • the AMF when the AMF cannot perceive the service area range of the UPF, when the UE mobility causes the current SMF to fail to select a suitable UPF to establish a connection with the target base station, the current SMF can determine whether there is a target base station established within the control range. The connected UPF, and informs the AMF of the judgment result, so that the AMF can re-select or add the SMF, thereby adding the SMF to select an appropriate UPF(s), so that the user plane connection can be established between the target base station and the DN.
  • the SMF determines, according to the target area information of the UE, whether the current SMF can select the UPF connected to the target base station, and if not, notifies the AMF, and the AMF reselects or adds the SMF according to the judgment result, thereby reselecting or adding the new The SMF selects the UPF to connect to the target base station.
  • Embodiment 2 is a diagrammatic representation of Embodiment 1:
  • FIG. 5 is a schematic flowchart of a network element selection provided by an embodiment of the present application.
  • ASMF SMF
  • target AN target AN
  • ISMF ISMF
  • IUPF IUPF
  • the premise of the second embodiment is that the AMF knows the location information of the AUP connected to the S-AN, such as the service area information or the identification information of the AUPF (related to the location), but the AMF does not know the service range information of all the UPFs managed by the current ASMF. .
  • the location information of the AUPF such as the AUPF service area information (UPF service area), may be sent to the S-AMF.
  • UPF service area AUPF service area information
  • the S-AN sends a handover requirement to the S-AMF when determining that the UE needs to switch from the S-AN to the T-AN (target AN).
  • the handover request includes an identifier of the PDU session and a UE location information, and the target area information of the UE may be location information of the target AN.
  • the identifier of the PDU session may be a PDU session ID.
  • the S-AMF After receiving the handover indication, the S-AMF sends a forward relocation request to the T-AMF.
  • the forward redirect request includes an ID of the PDU session and target area information of the UE.
  • S-AMF serves S-AN and T-AMF serves T-AN.
  • both the S-AN and the T-AN are located in the service area of the same AMF, the S-AMF and the T-AMF are the same AMF, and the process of selecting the network element in the embodiment of the present application does not Go to S502.
  • the S-AMF stores the service area information of the AUPF.
  • the forward redirection request sent by the S-AMF to the T-AMF further includes the service area information of the AUPF.
  • the T-AMF After receiving the forward redirection request, the T-AMF determines that the UE is located in the service area of the AUPF according to the target area information of the UE and the service area information of the AUPF, and does not need to perform an operation of updating the SMF and the UPF.
  • the T-AMF determines that the UE is located outside the service area of the AUPF according to the target area information of the UE and the service area information of the AUPF.
  • the T-AMF sends a PDU handover request 1 to the ASMF, where the handover request 1 includes target area information of the UE.
  • the handover request 1 further includes indication information, where the indication information is used to indicate that the UE is located outside the service area of the AUPF, that is, the AUPF cannot establish a user plane connection with the T-AN.
  • the handover request 1 may further include a DNN, a session and service continuity mode (SSC mode), a slice information, a PDU session type, a capability of the UPF (cache, local offload, etc.), a service area of the UPF, and an SMF.
  • SSC mode session and service continuity mode
  • the ASMF determines that there is no UPF that can establish a connection with the T-AN in the UPF other than the AUPF managed by the ASMF. For the specific determination manner, refer to the first embodiment, and details are not described herein again.
  • the AMF determines whether the current UPF can be connected to the target base station according to the UE location and the saved service area information of the UPF, and sends the initial judgment result to the current SMF, and the current SMF performs subsequent actions according to the initial judgment result. If the initial judgment result is that the current UPF can establish a connection with the target base station, only a simple session update is needed; if the initial judgment result is that the current UPF cannot establish a connection with the target base station, the SMF further determines whether there are other possible targets in the management scope. The UPF of the base station connection.
  • the SMF further judges that the UPF connected to the target base station can be found, reselect or add the UPF and complete the session update; if the appropriate UPF is not found, the judgment result is returned to the AMF, and the AMF is added or reselected. SMF, the newly added or reselected SMF selects the appropriate UPF to ensure the connection with the target base station.
  • the difference between the foregoing embodiment 2 and the first embodiment is that: in the second embodiment, the AMF and the SMF determine twice, and if the final SMF determines that there is no UPF connected to the target base station in the current SMF management scope, the SMF notifies the AMF by the AMF. The SMF is added or reselected, and accordingly, the SMF selects the UPF, and finally completes the user plane connection between the base station and the DN.
  • FIG. 6 is a schematic flowchart of a method for selecting a network element according to an embodiment of the present application. The method is applied to handover between base stations in different communication networks.
  • the first mobility management network element acquires service area information of the first session management network element during the process of the terminal accessing the first communication network.
  • the first session management network element During the process of connecting the terminal to the first communication network, the first session management network element provides a service for the terminal to satisfy the terminal to establish a user plane connection with the first communication network.
  • the first mobility management network element sends a first message to the second mobility management network element in a process in which the terminal is switched by the first communications network to the second communications network.
  • the first message includes the service area information of the first session management network element, so that the second mobility management network element determines whether to select the first part according to the service area information of the first session management network element.
  • Determining whether to select the second session management network element that is, determining whether the second session management network element needs to provide services for the terminal after the terminal switches from the first communication network to the second communication network, to satisfy the The terminal establishes a user plane connection with the second communication network.
  • the first mobility management network element is a mobility management network element corresponding to the first communication network
  • the second mobility management network element is a mobility management network element corresponding to the second communication network.
  • the second mobility management network element receives the first message from the first mobility management network element.
  • the second mobility management network element determines whether to select the second session management network element according to the service area information of the first session management network element.
  • the above solution provides a way of determining how to select a second session management network element during handover between base stations in different communication networks.
  • the terminal is switched from 4G to 5G.
  • the MME obtains the service area information of the first session management network element (such as the SMF deployed on the same device as the PGW-C) in the process of connecting the terminal to the 4G. Therefore, when the terminal is switched from the 4G network to the 5G network, the MME notifies the service area information of the first session management network element to the AMF, so that the AMF can determine whether the service area information of the first session management network element can also serve the terminal.
  • the process of connecting to the 5G it is determined whether it is necessary to perform an operation of selecting another session management network element.
  • the first message may further include location information of the terminal.
  • the location information of the terminal is also the target area information where the terminal is located.
  • the second mobility management network element determines whether to select the second session management network element according to the service area information of the first session management network element, which can be implemented as follows:
  • the second mobility management network element Determining to select the second session management network element
  • the second mobility management network element is determined when the terminal is in the service area of the first session management network element according to the location information of the terminal and the service area information of the first session management network element. It is determined that the second session management network element is not selected.
  • a base station (eNB) of a 4G communication network located in a source area is switched to a base station (AN) of a 5G communication network located in a target area as an example for detailed description.
  • the first mobility management network element is an MME
  • the second mobility management network element is an AMF.
  • the session management network element is a network element (ie, PGW-C+SMF) deployed by the PGW-C and the SMF.
  • the user plane network element is a network element (PGW-U+UPF) deployed by the PGW-U and the UPF.
  • the MME may acquire service area information of the PGW-C (SMF).
  • the service area information of the PGW-C (SMF) may be an identifier of PGW-C (SMF), or a service area range of PGW-C (SMF) or the like.
  • the service areas of the PGW-C and the SMF deployed may be the same or different. If they are the same, the service area information is both a PGW-C and a service area of the SMF; if different, the service area information is a service of the SMF. region.
  • FIG. 7 a flow chart of obtaining service area information of (PGW-C+SMF) is shown.
  • the UE sends an attach request to the eNB.
  • the eNB After receiving the attach request sent by the UE, the eNB forwards the attach request to the MME.
  • the attach request includes the UE's target location information (UE location).
  • the MME After receiving the attach request, the MME performs selection of SGW-C and PGW-C (ie, SMF).
  • the MME obtains an SGW-C list by querying the DNS server according to the UE location, and obtains a PGW-C list by querying the DNS server according to the Access Point Name (APN), and then first in the PGW-C list ( Depending on the load, capability, and other information of the network element, after determining a PGW-C, and then comparing the selected PGW-C and SGW-C lists, the SGW-C list is preferentially selected from the SGW-C list to be the same as the selected SGW-CIP address. SGW-C, if the IP addresses are the same, compare the selected PGW-C IP address with the SGW-C in the SGW-C list and the SGW-C with the PGW-C topology.
  • APN Access Point Name
  • the ultimate goal of selecting SGW-C and PGW-C is to select the corresponding SGW-U and PGW-U, where the SGW-U can be connected to the base station and the PGW-U can be connected to the data network DN.
  • the service areas of the SGW-C and the PGW-C are considered in the process of the MME selecting the SGW-C and the PGW-C.
  • the service areas of the SGW-C and the PGW-C are related to the service area range of the corresponding user plane, for example,
  • the SGW-C can control multiple SGW-Us
  • the service area of the SGW-C is split into many small service areas corresponding to the SGW-U, and the MME knows the service of the SGW-C when selecting the SGW-C.
  • the MME sends a create session request 1 (creat session request 1) to the selected SGW-C.
  • the SGW-C After receiving the create session request 1 sent by the MME, the SGW-C sends the create session request 2 to the selected PGW-C (ie, the SMF), where the create session request 2 is used to indicate that the SGW-C is established. User plane connection.
  • PGW-C ie, the SMF
  • the PGW-C selects the PGW-U (UPF) and sends a session establishment request to the selected PGW-U.
  • the PGW-U After receiving the session establishment request, the PGW-U creates a user plane connection and sends a session establishment request to the PGW-C.
  • the PGW-C After receiving the session establishment request, the PGW-C sends a creat session response 2 to the SGW-C.
  • the PGW-C may carry the service area information of itself (SMF) in the creat session response 2 and send it to the SGW-C.
  • SMS service area information of itself
  • the SGW-C forwards the creat session response2 to the MME. After receiving the service area information of the SMF, the MME saves it.
  • the MME sends an initial context setup request to the eNB.
  • the RRC connection reconfiguration is completed between the eNB and the UE.
  • the eNB sends an attach complete message (attach complete) to the MME.
  • the MME obtains the service area information of the PGW-C (SMF) by creating a session response message.
  • SMF PGW-C
  • the MME may obtain the service area information of the PGW-C (SMF) from the DNS server.
  • SMF service area information
  • the MME After the MME acquires the service area information of the PGW-C (SMF), and the UE is handed over to the base station (AN) of the 5G communication network by the base station (eNB) of the 4G communication network, the MME sets the service area of the PGW-C (SMF). The information is sent to the AMF, so that the AMF can determine whether the SMF needs to be selected again according to the service area information of the PGW-C (SMF) to ensure the user plane connection between the UE and the data network.
  • SMF service area information of the PGW-C
  • FIG. 8 a schematic diagram of a flow of a base station (AN) for a UE to be handed over by a base station (eNB) of a 4G communication network to a 5G communication network is shown.
  • the SMF (PGW-C) corresponding to the 4G communication network is referred to as ASMF
  • the SMF corresponding to the AN is referred to as ISMF.
  • the UPF (PGW-U) connected to the DN is called AUPF (ie, The UPF corresponding to the eNB)) refers to the selected UPF connected to the AN as IUPF.
  • the eNB sends a handover requirement to the MME when determining that the UE needs to switch from the eNB to the AN.
  • the handover request includes an identifier of the AN, an identifier of the AMF, and a UE location information.
  • the target area information of the UE may be the location information of the target AN, or the location information of the UE, or the identifier of the target cell corresponding to the location where the UE is located.
  • the MME After receiving the handover required, the MME sends a forward relocation request to the AMF.
  • the forward relocation request includes the UE location and the service area information of the ASMF.
  • the forwarding relocation request may further include an identifier of the AN, a session context, and a bearer context (including an address of the ASMF).
  • the AMF determines, according to the service area information of the ASMF, whether the second session management network element needs to be selected.
  • the AMF determines that the ISMF needs to be selected, that is, performs a selection operation. If it is determined that the UE is within the service area of the ASMF, the AMF does not perform the operation of selecting the ISMF.
  • the network policy can be configured in the AMF.
  • the AMF can perform the new ISMF or re-select the ISMF to replace the original ASMF according to the network policy.
  • S804 is executed.
  • the process of establishing a PDU session between the UE and the DN is performed. For details, refer to the process of establishing an existing PDU session, and details are not described herein.
  • the AMF sends a PDU session management request 1 to the selected ISMF.
  • the ISMF can obtain the address of the ASMF according to the PDU session update request 1, so that signaling interaction can be performed with the ASMF.
  • the PDU session management request may be a PDU session establishment/update/modification request.
  • the PDU session update request may be an Nsmf_PDU sesseion_update SMC Context request.
  • the bearer context information is included in the PDU session update request 1.
  • the bearer context includes the address information (address) of PGW-C (ie ASMF).
  • the ISMF After receiving the PDU session management request 1 sent by the AMF, the ISMF sends a PDU session management request 2 to the ASMF (PGW-C).
  • the ASMF After receiving the PDU session management request 2, the ASMF performs session modification corresponding to the N4 interface according to the bearer context and the PGW-U (ie, AUPF).
  • the ASMF sends a PDU session update response 2 to the ISMF, and the PDU session update response 2 is used to send some ASMF pre-acquired session information to the ISMF.
  • the PDU session management response may be a PDU session establishment/update/modification response.
  • the PDU session management response may be an Nsmf_PDU sesseion_update SMC Context response.
  • the PDU session management response includes AUP tunnel information (A-CN tunnel info).
  • the PDU session management response further includes session management information (such as N2 SM information) that is not perceived by the mobility management network element, and an identifier of the PDU session.
  • the session management information that is not perceived by the mobility management network element may also include a quality of service (QoS) profile.
  • QoS quality of service
  • the ISMF controls the IUPF to establish a tunnel between the IUGF and the AUPF and a tunnel between the IUPF and the AN according to the tunnel information of the AUPF and the N2 SM information.
  • the ISMF sends the PDU session management response 1 to the AMF.
  • the PDU session management response 1 includes information of a tunnel between the IUPF and the AUP (N9 tunnel info) and information of a tunnel between the IUPF and the AN (N3 tunnel info).
  • N9 tunnel info and N3 tunnel info are collectively referred to as I-CN tunnel info.
  • the AMF After receiving the PDU session management response 1 sent by the ISMF, the AMF sends a handover request to the AN.
  • the handover request includes I-CN tunnel info.
  • the AN After receiving the handover request, the AN sends a handover request acknowledgement (ACK) to the AMF.
  • ACK handover request acknowledgement
  • the AN tunnel info is included in the handover request ACK.
  • the AMF After receiving the handover request ACK, the AMF sends a PDU session management request 3 to the ISMF.
  • the PDU session management request instructs the ISMF to create an indirect forwarding tunnel for the session that needs to be handed over.
  • the PDU session update request 3 may be an Nsmf_PDU sesseion_update SMC Context request.
  • the PDU session update request 3 includes AN tunnel info of the intermediate forwarding tunnel.
  • the ISMF After receiving the PDU session management request 3 sent by the AMF, the ISMF performs an N4 session management process between the ISIF and the IUPF, and sends the AN tunnel info to the IUPF in the N4 session management process, so that the IUPF obtains the AN.
  • Tunnel information which controls the IUPF to establish a tunnel between the IUPF and the AN.
  • the ISIF and the IUPF obtain the N3 tunnel information and the N9 tunnel information of the intermediate forwarding tunnel of the IUPF.
  • the ISMF sends the PDU session management request 4 to the ASMF, where the PDU session management request includes an N9 tunnel info of the intermediate forwarding tunnel of the IUPF.
  • the ASMF After receiving the PDU session management request, the ASMF sends an N4 session management request, such as an N4 session modification request, to the AUP.
  • the N4 session modification request includes the N9 tunnel info of the intermediate forwarding tunnel of the IUPF.
  • the AUP After receiving the N4 session modification request, the AUP sends an N4 session management response, such as an N4 session modification response, to the ASMF.
  • the N4 session modification request includes A-CN tunnel info.
  • the ASMF sends a PDU session management response 4 to the ISMF.
  • the PDU session management response 4 is an acknowledgment message corresponding to the PDU session management request 3, and may be, for example, an Nsmf_PDU sesseion_update SMC Context response.
  • the PDU session management response 4 includes A-CN tunnel info.
  • the ISMF sends the PDU session management response 4 to the AMF.
  • the PDU session management response 4 includes A-CN tunnel info.
  • the AMF After receiving the PDU session update response 4 sent by the ISMF, the AMF sends a forward redirect response to the MME.
  • the forward redirect response includes A-CN tunnel info.
  • the MME sends an indirect data forwarding tunnel request to the SGW, to notify the SGW that indirect data forwarding is required, and informs the SGW of the uplink destination tunnel information that is indirectly forwarded.
  • the indirect data forwarding tunnel request is created by the createindiret data forwarding tunnel request, and the indirect data forwarding tunnel request includes the A-CN tunnel info.
  • the data that needs to be forwarded is sent to the SGW and then sent to the AUPF indicated by the A-CN tunnel info.
  • the SGW-C sends an indirect data forwarding tunnel response, such as a createindiret data forwarding tunnel response (including SGW tunnel info), to the MME.
  • an indirect data forwarding tunnel response such as a createindiret data forwarding tunnel response (including SGW tunnel info)
  • the foregoing embodiment provides a method for determining a second session management network element in a handover process between base stations in different communication networks, and details a specific handover procedure.
  • the MME obtains the service area information of the first session management network element in the process of connecting the terminal to the 4G, so that when the terminal is switched from 4G to 5G, the MME will The service area information of the first session management network element is notified to the AMF, so that the AMF can determine whether the service area information of the first session management network element can also serve the terminal connection 5G, thereby determining whether to perform other session management selection.
  • the operation of the network element if the selection is determined, ensures that the user plane network element in the control range of the other selected session management network element has a user plane network element that establishes a connection with the target base station, so that the UE can establish a connection with the DN through the target base station.
  • Data transmission is performed to avoid interruption of data transmission caused by the first session management network element of the source base station being unable to serve the target base station.
  • the embodiment of the present application further provides an apparatus, and the apparatus 900 is applied to a session management network element.
  • the device 900 may specifically be a processor in a session management network element, or a chip or chip system, or a function module or the like.
  • the apparatus may include a receiving unit 901, a processing unit 902, and a transmitting unit 903.
  • the processing unit 902 is configured to control and manage the actions of the device 900.
  • the receiving unit 901 is configured to execute S302, the processing unit 902 is configured to execute S303, and the sending unit 903 is configured to execute S304, where it is repeated, and details are not described herein again.
  • the processing unit 902 can also be used to indicate a process related to a session management network element (SMF or PGW-C) in any of the above embodiments and/or other processes of the technical solutions described herein.
  • SMS session management network element
  • the embodiment of the present application further provides a structure of a session management network element.
  • the session management network element 1000 may include a communication interface 1010 and a processor 1020.
  • the session management network element 1000 may further include a memory 1030.
  • the memory 1030 may be disposed inside the session management network element, and may also be disposed outside the session management network element.
  • the processing unit 902 shown in FIG. 9 above may each be implemented by the processor 1020.
  • the receiving unit 901 and the transmitting unit 903 can be implemented by the communication interface 1010.
  • the processor 1020 receives information or messages through the communication interface 1010 and is used to implement the methods performed by the session management network elements (SMF or PGW-C) described in Figures 3-8.
  • each step of the processing flow may complete the method executed by the session management network element described in FIG. 3 to FIG. 8 through the integrated logic circuit of the hardware in the processor 1020 or the instruction in the form of software.
  • the communication interface 1010 in the embodiment of the present application may be a circuit, a bus, a transceiver, or any other device that can be used for information interaction.
  • the other device may be a device connected to the session management device 1000, for example, the other device may be an AMF or a UPF or the like.
  • the processor 1020 in the embodiment of the present application may be a general-purpose processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or a transistor logic device, and a discrete hardware component, which may be implemented or executed.
  • a general purpose processor can be a microprocessor or any conventional processor or the like.
  • the steps of the method disclosed in the embodiments of the present application may be directly implemented as a hardware processor, or may be performed by a combination of hardware and software units in the processor.
  • Program code for processor 1020 to implement the above methods may be stored in memory 1030. Memory 1030 is coupled to processor 1020.
  • the coupling in the embodiments of the present application is an indirect coupling or communication connection between devices, units or modules, and may be in an electrical, mechanical or other form for information interaction between devices, units or modules.
  • Processor 1020 may operate in conjunction with memory 1030.
  • the memory 1030 may be a non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), or a volatile memory such as a random access memory (random). -access memory, RAM).
  • Memory 1030 is any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited thereto.
  • connection medium between the communication interface 1010, the processor 1020, and the memory 1030 is not limited in the embodiment of the present application.
  • the embodiment of the present application is connected by a bus between the memory 1030, the processor 1020, and the communication interface 1010 in FIG. 10, and the bus is indicated by a thick line in FIG. 10, and the connection manner between other components is only schematically illustrated. Not limited to limits.
  • the bus can be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, only one thick line is shown in FIG. 10, but it does not mean that there is only one bus or one type of bus.
  • the embodiment of the present application further provides an apparatus based on the same inventive concept as the above method embodiment.
  • the apparatus 1100 is applied to a mobility management network element.
  • the device may specifically be a processor in a mobility management network element, or a chip or chip system, or a functional module or the like.
  • the apparatus may include a communication unit 1101 and a processing unit 1102.
  • the communication unit 1101 includes a transmitting unit and a receiving unit.
  • the device can apply the mobility management network element in the embodiment shown in FIG. 3 to FIG. 5, such as AMF, the communication unit 1101 is used to execute S301, the processing unit 1102 is used to execute S305, and the processing unit 1102 can also be used to execute
  • the processes shown in FIG. 3 to FIG. 5 relate to the processing procedure of the mobility management network element and/or other processes of the technical solutions described in the present application.
  • the device may apply the first mobility management network element in the embodiment shown in FIG. 6 to FIG.
  • FIG. 8 such as the MME, and the communication unit 1101 is configured to execute S602, the processing unit 1102 is configured to execute S601, or FIG. 6 to FIG.
  • the embodiment shown in FIG. 8 relates to the processing of the first mobility management network element (MME) and/or other processes of the technical solutions described herein.
  • the device may also apply the second mobility management network element in the embodiment shown in FIG. 6 to FIG. 8 , such as AMF, the communication unit 1101 is used to execute S603, the processing unit 1102 is used to execute S604, or FIG. 6 is performed.
  • the embodiment shown in FIG. 8 relates to the processing of the second mobility management network element (AMF) and/or other processes of the technical solutions described herein.
  • AMF second mobility management network element
  • the embodiment of the present application further provides a structure of another mobility management network element.
  • the mobility management network element 1200 may include a communication interface 1210 and a processor 1220.
  • Memory 1230 may also be included in mobility management network element 1200.
  • the memory 1230 can be disposed inside the mobility management network element, and can also be disposed outside the mobility management network element.
  • the processing unit 1102 shown in FIG. 11 above may be implemented by the processor 1220.
  • the communication unit 1101 can be implemented by the communication interface 1210.
  • the processor 1220 receives the service data through the communication interface 1210 and is used to implement the method performed by any of the mobility management network elements (such as MME or AMF) described in FIGS. 3-8.
  • each step of the processing flow may complete the method performed by any of the mobility management network elements described in FIG. 3 to FIG. 8 through the integrated logic circuit of the hardware in the processor 1220 or the instruction in the form of software.
  • the communication interface 1210 in the embodiment of the present application may be a circuit, a bus, a transceiver, or any other device that can be used for information interaction.
  • the other device may be a device connected to the mobility management network element 1200.
  • the other device may be an AN or a UE.
  • the processor 1220 in the embodiment of the present application may be a general-purpose processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or a transistor logic device, and a discrete hardware component, which may be implemented or executed.
  • a general purpose processor can be a microprocessor or any conventional processor or the like.
  • the steps of the method disclosed in the embodiments of the present application may be directly implemented as a hardware processor, or may be performed by a combination of hardware and software units in the processor.
  • Program code for processor 1220 to implement the above methods may be stored in memory 1230. Memory 1230 is coupled to processor 1220.
  • Processor 1220 may operate in conjunction with memory 1230.
  • the memory 1230 may be a non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), or a volatile memory such as a random access memory (random). -access memory, RAM).
  • Memory 1230 is any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited thereto.
  • connection medium between the communication interface 1210, the processor 1220, and the memory 1230 is not limited in the embodiment of the present application.
  • the memory 1230, the processor 1220, and the communication interface 1210 are connected by a bus in FIG. 12, and the bus is indicated by a thick line in FIG. 12, and the connection manner between other components is only schematically illustrated. Not limited to limits.
  • the bus can be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, only one thick line is shown in Figure 12, but it does not mean that there is only one bus or one type of bus.
  • the embodiment of the present application further provides a computer storage medium, where the software program stores a software program, and the software program can implement any one or more of the foregoing when being read and executed by one or more processors.
  • the computer storage medium may include various media that can store program codes, such as a USB flash drive, a removable hard disk, a read only memory, a random access memory, a magnetic disk, or an optical disk.
  • the embodiment of the present application further provides a chip, where the chip includes a processor, for implementing functions related to any one or more of the foregoing embodiments, for example, acquiring or processing information involved in the foregoing method or Message.
  • the chip further includes a memory for the processor to execute necessary program instructions and data.
  • the chip can be composed of a chip, and can also include a chip and other discrete devices.
  • the user plane selected by the first session management network element serving the source base station may only establish a connection with the DN, and may not be able to communicate with the target.
  • the base station establishes a connection.
  • the first session management network element serving the source base station determines whether there are user plane network elements that can establish a connection with the target base station in the multiple user plane network elements under control. If not, Notifying the mobility management network element, so that the mobility management network element can select another session management network element to ensure that the user plane network element within the control range of the other selected session management network element has a connection with the target base station.
  • the network element is enabled, so that the UE can establish a connection with the DN through the target base station to perform data transmission, thereby avoiding data transmission interruption caused by the first session management network element of the source base station failing to serve the target base station.
  • embodiments of the present application can be provided as a method, system, or computer program product.
  • the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment in combination of software and hardware.
  • the application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) including computer usable program code.
  • the computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device.
  • the apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.
  • These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device.
  • the instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

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Abstract

本申请提供一种网元的选择方法及装置，用以解决数据业务中断的问题。该方法包括：第一会话管理网元从移动性管理网元接收第一消息，所述第一消息用于指示终端从源区域切换到目标区域；所述第一会话管理网元确定所述第一会话管理网元所管理的用户面网元中是否存在能与所述目标区域的基站建立连接的用户面网元；当确定不存在能与所述目标区域的基站建立连接的用户面网元时，所述第一会话管理网元向所述移动性管理网元发送第二消息，所述第二消息用于触发所述移动性管理网元执行选择第二会话管理网元的操作。

Description

一种网元的选择方法及装置
本申请要求在2018年2月14日提交中国专利局、申请号为201810151839.3、发明名称为“一种网元的选择方法及装置”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及通信技术领域，尤其涉及一种网元的选择方法及装置。
背景技术
在第五代移动通信技术(5G)系统中，目前接入与移动性管理实体(access and mobility management function，AMF)选择的会话管理功能实体(session management function，SMF)能够服务整个公共陆地移动网络(public land mobile network，PLMN)。SMF管理的用户面功能实体(user plane function，UPF)能够同时连接基站以及数据网络(datanetwork，DN)，来保证用户设备(user equipment，UE)与DN之间的数据连接。
现在针对网络系统部署时，部署了一些特定的UPF，而这些特定UPF只受特定的SMF控制，从而该特定的SMF并不能服务于整个PLMN。所以，当UE从源基站切换到新基站时，可能存在当前UPF和当前SMF控制范围内的其他UPF均不能与新基站建立连接，导致数据业务中断。
发明内容
本申请提供一种网元的选择方法及装置，用以解决数据业务中断的问题。
第一方面，本申请实施例提供了一种网元的选择方法，该方法包括：第一会话管理网元从移动性管理网元接收第一消息，所述第一消息用于指示终端从源区域切换到目标区域；所述第一会话管理网元确定所述第一会话管理网元所管理的用户面网元中是否存在能与所述目标区域的基站建立连接的用户面网元；当确定不存在能与所述目标区域的基站建立连接的用户面网元时，所述第一会话管理网元向所述移动性管理网元发送第二消息，所述第二消息用于触发所述移动性管理网元执行选择第二会话管理网元的操作。其中，源区域对应的基站为源基站，目标区域对应的基站为目标基站。
在UE从源基站移动到目标基站的服务区域时，服务于源基站的第一会话管理网元选择的用户面可能仅能与DN建立连接，而可能无法与目标基站建立连接，通过上述方案，由服务于源基站的第一会话管理网元确定其控制下的多个用户面网元中是否存在能够与目标基站建立连接的用户面网元，如果不存在，通知到移动性管理网元，从而移动性管理网元能够再选择其它会话管理网元，来保证再选择的其它会话管理网元的控制范围内的用户面网元存在与目标基站建立连接的用户面网元，从而UE能够通过目标基站与DN建立连接进行数据传输，避免了由于源基站的第一会话管理网元无法服务于目标基站导致的数据传输中断。
在一种可能的设计中，所述第一消息中包括所述终端的目标区域信息，所述第一会话管理网元确定所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元，可以通过如下方式实现：
所述第一会话管理网元根据所述终端的目标区域信息和所述第一会话管理网元所管理的一个或者多个用户面网元的服务区域信息，确定所述终端不在所述第一会话管理网元所管理的任一用户面网元的服务区域内，则确定所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元；或者，
所述第一会话管理网元根据所述终端的目标区域信息，和所述第一会话管理网元的服务区域信息，确定所述终端不在所述第一会话管理网元所管理的任一用户面网元的服务区域内，则确定所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元。
通过上述设计，提供了一种简单有效的确定所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元的方式。
在一种可能的设计中，所述第一消息中包括所述终端的目标区域信息以及所述终端的会话管理信息，所述第一会话管理网元确定所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元，具体可以通过如下方式实现：
所述第一会话管理网元根据所述终端的目标区域信息，和所述第一会话管理网元所管理的一个或者多个用户面网元的服务区域信息，确定所述终端位于所述第一会话管理网元所管理的至少一个用户面网元的服务区域内；所述第一会话管理网元根据所述终端的会话管理信息确定所述至少一个用户面网元不能与所述目标区域的基站建立连接；或者，
所述第一会话管理网元根据所述终端的目标区域信息，和所述第一会话管理网元的服务区域信息，确定所述终端位于所述第一会话管理网元所管理的至少一个用户面网元的服务区域内；所述第一会话管理网元根据所述终端的会话管理信息确定所述至少一个用户面网元不能与所述目标区域的基站建立连接。
通过上述设计，提供了一种简单有效的确定所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元的方式。
在一种可能的设计中，所述第一会话管理网元确定所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元，包括：
所述第一会话管理网元确定连接所述源区域的基站的第一用户面网元不能与所述目标区域的基站建立连接，且确定所述第一会话管理网元管理的除所述第一用户面网元以外的用户面网元均不能与所述目标区域的基站建立连接。
可选地，可以由第一会话管理网元确定连接所述源区域的基站的第一用户面网元是否能与所述目标区域的基站建立连接，还可以由移动性管理网元确定连接所述源区域的基站的第一用户面网元是否能与所述目标区域的基站建立连接。
具体的，所述第一消息还包括第一指示信息，所述第一指示信息用于指示所述第一用户面网元不能与所述目标区域的基站建立连接；所述第一会话管理网元确定所述第一用户面网元不能与所述目标区域的基站建立连接，具体通过如下方式实现：
所述第一会话管理网元基于第一指示信息确定所述第一用户面网元不能与所述目标区域的基站建立连接。
上述设计，通过移动性管理网元先针对连接源区域的基站的第一用户面网元是否能够与所述目标区域的基站建立连接作初次判断，如果第一用户面网元能够与所述目标区域的基站建立连接，则不需要再触发第一会话管理网元做判断，从而节省了信令资源。
在一种可能的设计中，所述第二消息用于通知所述移动性管理网元在所述第一会话管 理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元；或者，所述第二消息包括第二指示信息，所述第二指示信息用于指示所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元。
上述设计，提供了两种触发所述移动性管理网元执行选择第二会话管理网元的操作。
在一种可能的设计中，所述第一消息包括第三指示信息，所述第三指示信息用于指示所述移动性管理网元在保持所述第一会话管理网元为所述终端服务的基础上，执行增加所述第二会话管理网元的操作；或者，所述第三指示信息用于指示所述移动性管理网元执行重新选择所述第二会话管理网元的操作。
上述设计中，由第一会话管理网元来确定移动性管理网元执行新增或者重选第二会话管理网元的操作。
在一种可能的设计中，所述第二消息中包括所述第一用户面网元的标识。基于此，所述移动性管理网元根据所述第二消息选择第二会话管理网元后，所述移动性管理网元可以将该第一用户面网元的标识发送给所述第二会话管理网元，以使得所述第二会话管理网元选择的第二用户面网元分别能够所述目标区域的基站以及所述第一用户面网元建立连接。
第二方面，本申请实施例提供了一种网元的选择方法，该方法包括：
移动性管理网元向第一会话管理网元发送第一消息，所述第一消息用于指示终端由源区域切换到目标区域；移动性管理网元接收所述第一会话管理网元发送的第二消息，所述第二消息用于指示所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元；所述移动性管理网元根据所述第二消息选择第二会话管理网元，以便于所述第二会话管理网元选择与所述目标区域的基站建立连接的用户面网元。
上述方案，在UE从源基站移动到目标基站的服务区域时，服务于源基站的第一会话管理网元选择的用户面可能仅能与DN建立连接，而可能无法与目标基站建立连接，通过上述方案，由服务于源基站的第一会话管理网元确定其控制下的多个用户面网元中不存在能够与目标基站建立连接的用户面网元时，通知到移动性管理网元，移动性管理网元在收到通知后，能够再选择其它会话管理网元，来保证再选择的其它会话管理网元的控制范围内的用户面网元存在与目标基站建立连接的用户面网元，从而UE能够通过目标基站与DN建立连接进行数据传输，避免了由于源基站的第一会话管理网元无法服务于目标基站导致的数据传输中断。
在一种可能的设计中，移动性管理网元向第一会话管理网元发送第一消息之前，所述方法还包括：所述移动性管理网元根据连接所述源区域的基站的第一用户面网元的信息，确定所述第一用户面网元不能与所述目标区域的基站建立连接；所述第一用户面网元的服务区域信息由所述第一会话管理网元在所述终端接入所述源区域的基站的流程中发送给所述移动性管理网元，所述第一用户面网元的信息包括所述第一用户面网元的服务区域信息和/或所述第一用户面网元的标识；所述移动性管理网元向所述第一会话管理网元发送的第一消息中还包括第一指示信息，所述第一指示信息用于指示所述第一用户面网元不能与所述目标区域的基站建立连接。
上述设计中，由移动性管理网元提前获取到连接源区域的基站的第一用户面网元的信息，从而在终端由所述源区域切换到所述目标区域过程中，可以预先确定第一用户面网元是否能够与目标区域的基站建立连接，在确定是时，不再需要触发会话管理网元执行判断操作。
在一种可能的设计中，所述第二消息用于通知所述第一会话管理网元在所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元；或者，所述第二消息包括第二指示信息，所述第二指示信息用于指示所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元。
在一种可能的设计中，所述第一消息包括第三指示信息，所述第三指示信息用于指示所述移动性管理网元执行在保持所述第一会话管理网元为所述终端服务的基础上，增加为所述终端服务的会话管理网元的操作；或者，所述第三指示信息用于指示所述移动性管理网元执行重新选择为所述终端服务的会话管理网元的操作。
在一种可能的设计中，所述第一消息中包括连接所述源区域的基站的第一用户面网元的标识；所述移动性管理网元根据所述第二消息选择第二会话管理网元后，所述方法还包括：所述移动性管理网元向所述第二会话管理网元发送所述第一用户面网元的标识，以使得所述第二会话管理网元选择的第二用户面网元分别能够所述目标区域的基站以及所述第一用户面网元建立连接。
通过上述设计，第一会话管理网元在第一消息将连接所述源区域的基站的第一用户面网元的标识发送给移动性管理网元，从而移动性管理网元将该标识发送给选择的第二会话管理网元，进而第二会话管理网元在选择与目标基站连接的用户面网元时，根据该第一用户面网元来选择。
第三方面，本申请实施例提供了一种网元的选择方法，该方法包括：
在终端接入第一通信网络过程中，第一移动性管理网元获取第一会话管理网元的服务区域信息，所述第一会话管理网元用于为所述终端与所述第一通信网络连接的过程中提供服务；在终端由所述第一通信网络切换到第二通信网络的过程中，所述第一移动性管理网元向所述第二移动性管理网元发送第一消息；其中，所述第一消息包括所述第一会话管理网元的服务区域信息，以便于所述第二移动性管理网元根据所述第一会话管理网元的服务区域信息，确定是否选择第二会话管理网元，所述第二会话管理网元用于为所述终端与所述第二通信网络连接的过程中提供服务。
上述方案，提供了一种在不同的通信网络中基站间的切换过程中如何决定选择第二会话管理网元的方式。比如：终端由4G切换到5G，MME在终端接入4G时，获取服务于终端连接4G过程中的第一会话管理网元的服务区域信息，从而在终端由4G切换到5G时，MME将该第一会话管理网元的服务区域信息通知到AMF，从而AMF能够确定该第一会话管理网元的服务区域信息是否也能够服务于终端连接5G的过程中，进而确定是否需要执行选择其他会话管理网元的操作。
第四方面，本申请实施例提供了一种网元的选择方法，该方法包括：在终端由所述第一通信网络切换到第二通信网络的过程中，第二移动性管理网元从第一移动性管理网元接收第一消息，所述第一消息包括第一会话管理网元的服务区域信息，所述第一会话管理网元用于为所述终端在与所述第一通信网络连接的过程中提供服务；所述第二移动性管理网元根据所述第一会话管理网元的服务区域信息，确定是否选择第二会话管理网元，所述第二会话管理网元用于为所述终端在与所述第二通信网络连接的过程中提供服务。
上述方案，提供了一种在不同的通信网络中基站间的切换过程中如何决定选择第二会话管理网元的方式。比如由4G切换到5G，MME在终端接入4G时，获取服务于终端连接4G过程中的第一会话管理网元的服务区域信息，从而在终端由4G切换到5G时，MME 将该第一会话管理网元的服务区域信息通知到AMF，从而AMF能够确定该第一会话管理网元的服务区域信息是否也能够服务于终端连接5G的过程中，进而确定是否需要执行选择其他会话管理网元的操作。
在一种可能的设计中，所述第一消息还包括所述终端的位置信息；所述第二移动性管理网元根据所述第一会话管理网元的服务区域信息，确定是否选择第二会话管理网元，包括：在根据所述终端的位置信息和所述第一会话管理网元的服务区域信息，确定所述终端不在所述第一会话管理网元的服务区域内时，所述第二移动性管理网元确定选择所述第二会话管理网元；或者，在根据所述终端的位置信息和所述第一会话管理网元的服务区域信息，确定所述终端在所述第一会话管理网元的服务区域内时，所述第二移动性管理网元确定不选择所述第二会话管理网元。
上述设计，提供了一种简单有效的由第二移动性管理网元确定是否选择所述第二会话管理网元的方式。
第五方面，本申请实施例提供一种装置。示例性的，该装置可以是会话管理网元，也可以是能够应用于会话管理网元的芯片。该装置具有实现上述第一方面的各实施例的功能。该功能可以通过硬件实现，也可以通过硬件执行相应的软件实现。该硬件或软件包括一个或多个与上述功能相对应的模块。
第六方面，本申请实施例提供一种装置，包括：处理器和存储器；该存储器用于存储指令，当该装置运行时，该处理器执行该存储器存储的该指令，以使该装置执行上述第一方面或第一方面的任一实现方法中的网元的选择方法。需要说明的是，该存储器可以集成于处理器中，也可以是独立于处理器之外。
第七方面，本申请实施例提供一种装置，该装置包括处理器，所述处理器用于与存储器耦合，并读取存储器中的指令并根据所述指令执行上述第一方面或第一方面的任一实现方法中的网元的选择方法。
第八方面，本申请实施例提供一种装置。示例性的，该装置可以是移动性管理网元，也可以是应用于移动性管理网元中的芯片。该装置具有实现上述第二方面的各实施例的功能或者该装置具有实现上述第三方面的功能或者该装置具有实现上述第四方面的功能。该功能可以通过硬件实现，也可以通过硬件执行相应的软件实现。该硬件或软件包括一个或多个与上述功能相对应的模块。
第九方面，本申请实施例提供一种装置，包括：处理器和存储器；该存储器用于存储指令，当该装置运行时，该处理器执行该存储器存储的该指令，以使该装置执行上述第二方面或第二方面的任一实现方法中的网元的选择方法，或者执行上述第三方面中的网元的选择方法，或者执行上述第四方面或第四方面的任一实现方法中的网元的选择方法。需要说明的是，该存储器可以集成于处理器中，也可以是独立于处理器之外。
第十方面，本申请实施例提供一种装置，该装置包括处理器，所述处理器用于与存储器耦合，并读取存储器中的指令并根据所述指令执行上述第二方面或第二方面的任一实现方法中的网元的选择方法，或者执行上述第三方面中的网元的选择方法，或者执行上述第四方面或第四方面的任一实现方法中的网元的选择方法。
第十一方面，本申请实施例还提供一种可读存储介质，所述可读存储介质中存储有程序或指令，当其在计算机上运行时，使得上述各方面的任意网元的选择方法被执行。
第十二方面，本申请实施例还提供一种包含指令的计算机程序产品，当其在计算机上 运行时，使得计算机执行上述各方面中的任意网元的选择方法。
第十三方面，本申请实施例还提供一种芯片系统，其特征在于，包括：所述芯片系统包括至少一个处理器，和接口电路，所述接口电路和所述至少一个处理器通过线路互联，所述处理器通过运行指令，以执行上述第一方面及第一方面的任一设计所述的方法。
第十四方面，本申请实施例还提供一种芯片系统，其特征在于，包括：所述芯片系统包括至少一个处理器，和接口电路，所述接口电路和所述至少一个处理器通过线路互联，所述处理器通过运行指令，以执行上述第二方面及第二方面的任一设计所述的方法，或者上述第三方面及第三方面的任一设计所述的方法，或者上述第四方面及第四方面的任一设计所述的方法。
第十五方面，本申请实施例还提供一种系统，该系统包括会话管理网元以及移动性管理网元，所述会话管理网元可用于执行上述第一方面及第一方面的任一方法中由第一会话管理网元执行的步骤，所述移动性管理网元可用于执行上述第二方面及第二方面的任一方法中由移动性管理网元执行的步骤。
在一个可能的设计中，该系统还可以包括本发明实施例提供的方案中与该会话管理网元和/或移动性管理网元进行交互的其他设备，例如用户面网元，或者终端等等。
第十六方面，本申请实施例还提供一种系统，该系统包括第一通信网络的第一移动性管理网元、第二通信网络的第二移动性管理网元，所述第一移动性管理网元可用于执行上述第三方面中由第一移动性管理网元执行的步骤，所述第二移动性管理网元可用于执行上述第四方面或者第四方面的任一方法中由第二移动性管理网元执行的步骤。在一个可能的设计中，该系统还可以包括本发明实施例提供的方案中与该两种移动性管理网元进行交互的其他设备，例如，终端、会话管理网元等等。
另外，第五方面至第十六方面中任一种设计方式所带来的技术效果可参见第一方面至第四方面中不同实现方式所带来的技术效果，此处不再赘述。本申请实施例的这些方面或其他方面在以下实施例的描述中会更加简明易懂。
附图说明
图1A～图1C为本申请实施例提供的系统架构示意图；
图2A～图2B为本申请实施例提供的应用场景下的系统结构示意图；
图3为本申请实施例提供的一种网元的选择方法流程图；
图4为本申请实施例一提供的一种网元的选择方法示意图；
图5为本申请实施例二提供的一种网元的选择方法示意图；
图6为本申请实施例提供的另一种网元的选择方法流程图；
图7为本申请实施例三提供的UE附着方法示意图；
图8为本申请实施例三提供的网元的选择方法示意图；
图9为本申请实施例提供的一种装置结构示意图；
图10为本申请实施例提供的会话管理网元结构示意图；
图11为本申请实施例提供的另一种装置结构示意图；
图12为本申请实施例提供的移动性管理网元结构示意图。
具体实施方式
本申请实施例可以适用于4G(第四代移动通信系统)演进系统，如长期演进(long term evolution，LTE)系统，或者还可以为5G(第五代移动通信系统)系统，如采用新型无线接入技术(new radio access technology，New RAT)的接入网；云无线接入网(Cloud Radio Access Network，CRAN)等通信系统。
图1A示例性示出了本申请实施例适用的一种系统架构示意图。应理解，本申请实施例并不限于图1所示的系统中，此外，图1A中的装置可以是硬件，也可以是从功能上划分的软件或者以上二者结合后的结构。如图1A所示，本申请实施例提供的系统架构包括终端、基站、移动性管理网元、会话管理网元、用户面网元以及数据网络(datanetwork，DN)。终端通过基站以及用户面网元与DN通信。基站与移动性管理网元之间通过N2接口相连。用户面网元与基站之间通过N3接口相连，用户面网元与DN之间可以通过N6接口相连，多个UPF之间通过N9接口相连。接口名称只是一个示例说明，本申请实施例对此不作具体限定。
其中图1A中所示的网元既可以是4G架构中的网元、还可以是5G架构中的网元。
数据网络(datanetwork，DN)，为用户提供数据传输服务，可以是PDN网络，如因特网(internet)、IP多媒体业务(IP Multi-media Service，IMS)等。
参见图1B所示的5G的系统架构示意图以及图1C所示的4G和5G融合后的系统架构图：移动性管理网元可以包括是5G中的接入与移动性管理实体(access and mobility management function，AMF)、或者是4G中服务网关(Serving GateWay，SGW)的控制面功能(SGW-C)和移动性管理实体(mobility management entity，MME)，或者是以上网元融合后形成的控制功能的全部或部分。移动性管理网元负责移动网络中UE的接入与移动性管理。其中，AMF，负责UE接入与移动性管理，NAS消息路由，SMF选择等。AMF可以作为中间网元，用来传输UE和SMF之间的会话管理消息。本申请实施例中涉及到的第一移动性管理网元为MME、涉及到的第二移动性管理网元为AMF。在未来通信(例如6G或者其他的网络中)，移动性管理网元仍可以是AMF网元，或有其它的名称，本申请不做限定。
会话管理网元，负责转发路径管理，如向用户面网元下发报文转发策略，指示用户面网元根据报文转发策略进行报文处理和转发。会话管理网元可以是5G中的会话管理功能实体(session management function，SMF)，负责会话管理，如会话创建/修改/删除，UPF选择以及用户面隧道信息的分配和管理等。会话管理网元还可以是4G中的服务网关(Serving GateWay，SGW)的控制面功能(SGW-C)或分组数据网(packet data network，PDN)网关(gate way，GW)的控制面功能(PGW-C)，会话管理网元还可以是SMF和PGW-C网元融合后形成的控制功能的全部或部分。在未来通信(例如6G或者其他的网络中)，会话管理网元仍可以是SMF网元，或有其它的名称，本申请不做限定。
用户面网元可以是5G架构中的用户面功能实体(user plane function，UPF)，如图1B或者图1C所示。UPF负责报文处理与转发。用户面网元还可以是PGW的转发面功能(PGW-U)、SGW的转发面功能(SGW-U)、路由器、交换机等物理或虚拟的转发设备。在未来通信(例如6G或者其他的网络中)，用户面网元仍可以是UPF网元，或有其它的名称，本申请不做限定。
本申请实施例提供的系统架构中还可以包括策略控制功能实体(policy controlfunction，PCF)或者为策略计费控制功能实体(policy and charging controlfunction，PCRF)。其中， PCF或者PCRF负责策略控制决策和基于流计费控制。
系统架构中还可以包括用户数据管理实体(subscriber data management，SDM)，或者归属签约用户服务器(home subscriber server，HSS)。用户数据管理实体英文还可以对应于User Data Management或unified data management，简称还可以对应于UDM。SDM、UDM或者HSS用于帮助运营商实现对所有与用户相关的数据的统一管理。
网络功能库功能((network function，NF)repository function，NRF)中存储了很多网元的信息，比如SMF的信息，UPF的信息，AMF的信息等。网络中AMF、SMF、UPF等网元都可能与NRF相连，一方面可以将自身的网元信息注册到NRF，另一方面其他网元可以从NRF中获得已经注册过的网元的信息。其他网元(比如AMF)可以根据网元类型、数据网络标识、未知区域信息等，通过向NRF请求获得可选的网元。如果域名系统(domain name system，DNS)服务器集成在NRF，那么相应的选择功能网元(比如AMF)可以向NRF请求获得要选择的其他网元(比如SMF)。
基站作为接入网络(access network，AN)的一个具体实现形式，还可以称为接入节点，如果是无线接入的形式，称为无线接入网(radio access network，RAN)，如图1B或者1C所示，为终端提供无线接入服务。接入节点具体可以是全球移动通信(global system for mobile communication，GSM)系统或码分多址(code division multiple access，CDMA)系统中的基站，也可以是宽带码分多址(wideband code division multiple access，WCDMA)系统中的基站(NodeB)，还可以是LTE系统中的演进型基站(evolutional node B，eNB或eNodeB)，或者是5G网络中的基站设备、小基站设备、无线访问节点(WiFi AP)、无线互通微波接入基站(worldwide interoperability for microwave access base station，WiMAX BS)等，本申请对此并不限定。
终端，也可称为接入终端、用户设备(user equipment，UE)，用户单元、用户站、移动站、移动台、远方站、远程终端、移动设备、用户终端、无线通信设备、用户代理或用户装置等。图1B和图1C中以UE为例进行说明。终端可以是蜂窝电话、无绳电话、会话启动协议(session initiation protocol，SIP)电话、无线本地环路(wireless local loop，WLL)站、个人数字处理(personal digital assistant，PDA)、具有无线通信功能的手持设备、计算设备或连接到无线调制解调器的其它处理设备、车载设备、可穿戴设备、物联网终端设备，比如火灾检测传感器、智能水表/电表、工厂监控设备等等。
另外系统架构中还可以包括网络应用功能(application function，AF)。AF，主要对转发面行为进行动态策略/计费控制。这些业务需要动态策略和计费控制。AF传送PCF需要的动态会话信息，接收IP连接接入网(IP-CAN)的特定信息和IP-CAN承载层事件的确认。
上述功能既可以是硬件设备中的网络元件，也可以是在专用硬件上运行软件功能，或者是平台(例如，云平台)上实例化的虚拟化功能。
需要说明的是，本申请中涉及的多个，是指两个或两个以上。“和/或”，描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。字符“/”一般表示前后关联对象是一种“或”的关系。
同时，应当理解，尽管在本申请实施例中可能采用术语第一、第二、第三等来描述各种消息、请求、网元，但这些消息、请求、设备以及核心网设备不应限于这些术语。这些 术语仅用来将消息、请求、网元彼此区分开。
现有技术SMF服务于整个PLMN，因而AMF依靠数据网络名称、切片信息、签约信息、接入技术等信息中的一项或多项选择SMF，比如仅根据数据网络名称(data network name，DNN)来选择一个SMF，该SMF总是可以根据用户位置信息选择一个合适的UPF，保证与基站的数据连接。针对网络系统部署时，部署了一些特定的UPF，而这些特定UPF只受特定的SMF控制的情况，该特定的SMF的服务区域是被限定在特定范围的，并不能服务于整个PLMN。因而当UE从源区域移动到目标区域，从源基站切换到目标基站时，AMF根据DNN等信息选择SMF，该SMF选择的UPF仅能保证与DN建立连接，可能无法与目标基站建立连接，从而导致UE在移动过程中，切换基站之后无法通过目标基站与DN建立连接而导致数据传输中断。
基于此，本申请实施例提供了一种网元的选择方法及装置，用以解决现有UE切换到目标基站时，数据传输中断的问题。具体的，AMF如何确定当前SMF不能满足数据传输的需求，需要选择SMF。另外，AMF如何选择合适SMF，使得该SMF管理的UPF能够与目标基站建立连接，从而保证UE能够通过选择的UPF与DN之间进行数据传输。其中，方法和装置是基于同一发明构思的，由于方法及装置解决问题的原理相似，因此装置与方法的实施可以相互参见，重复之处不再赘述。
其中选择合适的SMF，可以是在AMF根据DNN等信息确定的源SMF的基础上再新增加一个SMF，或者AMF重新选择一个SMF。
具体的，针对UE初始接入基站1时，AMF首先根据DNN等信息选择一个SMF，可参考现有技术，该SMF选择一个或者多个UPF能够来保证与基站1和数据网络建立起用户面连接，比如某一个UPF既能和基站1连接又能和DN连接，或者其中一个UPF能和基站1连接，另一个UPF能和DN连接。但是UE在由基站1切换到基站2，该SMF可能不能选择一个或多个UPF来保证与基站2建立起用户面连接。
一方面，当前的SMF至少可以选择一个UPF与DN连接，可以由AMF再选择一个SMF，AMF选择的SMF再选择一个UPF或者多个UPF与基站2连接即可。
另一方面，AMF还可以再重新选择一个SMF，该SMF选择的一个或者多个UPF既能够与DN建立连接，也能够与基站2建立连接。
例如，参见图2A所示，SMF1管理UPF1，SMF2管理UPF2。UE在连接AN1时，AMF根据DNN选择的SMF是SMF2，SMF2选择的UPF2既能连接DN又能连接AN1。但是由于SMF2并非服务于整个PLMN的，从而在UE移动之后，由AN1切换到AN2时，SMF2管理的UPF2不能够与AN2建立连接。在此基础上AMF可以再选择一个SMF1，从而SMF1选择的UPF1能够与UPF2以及AN2建立连接，从而保证UE与DN之间的数据传输不中断。
另外，需要说明的是，UE与DN之间建立连接，由于部署等原因网络中需要有多个SMF，并在SMF的控制下选择多个UPF建立用户面连接。从而图2所示的架构中，在SMF1和SMF2之间可以还有其他的SMF，在UPF1和UPF2之间还有其他的UPF。
例如，参见图2B所示，SMF1管理UPF1，SMF2管理UPF2。UE在连接AN1时，AMF根据DNN选择的SMF是SMF2，SMF2选择的UPF2既能连接DN又能连接AN1。但是由于SMF2并非服务于整个PLMN的，从而在UE由AN1的服务区域移动到AN2的服务区域时，SMF2管理的UPF2不能够与AN2建立连接。再此基础上AMF可以重新选 择一个SMF1，从而SMF1选择的UPF1能够与DN以及AN2建立连接，从而保证UE与DN之间的数据传输不中断。
下面针对会话管理网元的选择方案进行具体描述。
参见图3所示，为本申请实施例提供了网元的选择方法流程示意图。UE从一个区域(源区域)移动到另一个区域(目标区域)。两个区域的对应的基站不同，后续为了描述方便，将源区域的基站称为源基站，目标区域的基站称为目标基站。
S301，移动性管理网元向第一会话管理网元发送第一消息，所述第一消息用于指示终端由源区域切换到目标区域。其中第一会话管理网元是所述移动性管理网元根据DNN、切片信息、签约信息、接入技术等信息中的一项或多项确定的会话管理网元。
其中，第一消息可以是切换请求(handover request)消息，或者用于指示终端由源区域切换到目标区域的消息均适用于本申请实施例。
S302，第一会话管理网元从移动性管理网元接收第一消息。
S303，所述第一会话管理网元确定所述第一会话管理网元所管理的用户面网元中是否存在能与所述目标区域的基站建立连接的用户面网元。
S304，当确定不存在能与所述目标区域的基站建立连接的用户面网元时，所述第一会话管理网元向所述移动性管理网元发送第二消息，其中，所述第二消息用于触发所述移动性管理网元执行选择第二会话管理网元的操作。从而所述第二会话管理网元选择与所述目标区域的基站建立连接的用户面网元。
S305，所述移动性管理网元根据所述第二消息选择第二会话管理网元，以便于所述第二会话管理网元选择与所述目标区域的基站建立连接的用户面网元。
在UE从源基站移动到目标基站的服务区域时，服务于源基站的第一会话管理网元选择的用户面可能仅能与DN建立连接，而可能无法与目标基站建立连接。通过上述方案，由服务于源基站的第一会话管理网元确定其控制下的多个用户面网元中是否存在能够与目标基站建立连接的用户面网元，如果不存在，通知到移动性管理网元，从而移动性管理网元能够再选择其它会话管理网元，来保证再选择的其它会话管理网元的控制范围内的用户面网元存在与目标基站建立连接的用户面网元，从而UE能够通过目标基站与DN建立连接进行数据传输，避免了由于源基站的第一会话管理网元无法服务于目标基站导致的数据传输中断。
可选地，所述第一消息中还可以包括所述终端的目标区域信息(比如终端的位置信息)。所述终端的目标区域信息可以是位于目标区域的基站的位置信息/标识或者目标区域对应目标小区的位置信息/标识等)，所述第一会话管理网元确定所述第一会话管理网元所管理的用户面网元中是否存在能与所述目标区域的基站建立连接的用户面网元可以通过如下任一方式实现：
第一种可能的实现方式：所述第一会话管理网元根据所述终端的目标区域信息和所述第一会话管理网元所管理的一个或者多个用户面网元的服务区域信息(或者第一会话管理网元的服务区域信息)，确定所述终端不在所述第一会话管理网元所管理的任一用户面网元的服务区域内，即确定所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元。
如果第一会话管理网元获得它自身的服务区域信息，该服务区域信息可以反映它所管理的一个或多个用户面网元的服务区域信息，那么所述第一会话管理网元根据所述终端的 目标区域信息和所述第一会话管理网元的服务区域信息，确定所述终端不在所述第一会话管理网元所管理的任一用户面网元的服务区域内，即确定所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元。
第二种可能的实现方式：所述第一会话管理网元根据所述终端的目标区域信息和所述第一会话管理网元所管理的一个或者多个用户面网元的服务区域信息(或者所述第一会话管理网元的服务区域信息)，确定所述终端位于所述第一会话管理网元所管理的至少一个用户面网元(如用户面网元A)的服务区域内；所述第一会话管理网元根据所述终端的会话管理信息确定所述至少一个用户面网元(如用户面网元A)不能与所述目标区域的基站建立连接。
如果第一会话管理网元获得它自身的服务区域信息，该服务区域信息可以反映它所管理的一个或多个用户面网元的服务区域信息，那么所述第一会话管理网元根据所述终端的目标区域信息和所述第一会话管理网元的服务区域信息，确定所述终端在所述第一会话管理网元所管理的任一用户面网元的服务区域内；所述第一会话管理网元根据所述终端的会话管理信息确定所述至少一个用户面网元不能与所述目标区域的基站建立连接。
所述第一会话管理网元在所述至少一个用户面网元中尝试选择至少一个UPF来匹配终端的会话管理信息。若至少一个UPF均无法匹配终端的会话管理信息，则所述至少一个用户面网元不能与所述目标区域的基站建立连接。
其中终端的会话管理信息包括如下信息：DNN、会话和业务连续性模式(Session and Service Continuity mode，SSC mode)、切片信息、会话类型、用户面网元的能力(缓存、本地分流等)、用户面网元的服务区域等信息中的一项或多项。终端的会话管理信息可以由移动性管理网元从签约服务器中获取后发送给第一会话管理网元。
例如：第一会话管理网元管理的用户面网元包括用户面网元A和用户面网元B，第一会话管理网元确定终端所在的目标区域位于第一会话管理网元管理的用户面网元A的服务区域内，然后第一会话管理网元确定该用户面网元A是否符合上述会话管理信息，若不符合，则确定该用户面网元A不能与目标区域的基站建立连接，比如用户面网元A不符合终端的会话管理信息中的SSCmode的要求，则确定该用户面网元A不能与目标区域的基站建立连接。
上述终端的会话管理信息可以是在会话创建过程中，第一会话管理网元获取到的。比如SSC mode是由终端在会话创建过程中由终端发送给第一会话管理网元。又比如，用户面网元的能力(缓存、本地分流等)、用户面网元的服务区域等信息可以由第一会话管理网元用户的签约数据中获得。
第三种可能的实现方式：第一会话管理网元尝试去选择满足条件的用户面网元，如果选择到了就是存在，如果没有选到就是不存在。具体条件可以包括：UE location、DNN、SSC mode、切片信息、PDU会话类型、用户面网元的能力(缓存、本地分流等)、用户面网元的服务区域等信息中的一项或多项。具体可以参见现有SMF选择UPF的方式。
另外，本申请实施例中，所述第一会话管理网元确定所述第一会话管理网元所管理的用户面网元中是否存在能与所述目标区域的基站建立连接的用户面网元，具体可以通过如下方式实现：
方式1，第一会话管理网元可以先确定连接所述源基站的第一用户面网元是否能与所述目标基站建立连接，若不能，则再确定所述第一会话管理网元管理的除所述第一用户面 网元以外的用户面网元是否能与所述目标基站建立连接。
方式2，在所述第一会话管理网元管理的用户面网元中不区分连接源基站的用户面网元与其它用户面网元。进而第一会话管理网元可以直接确定所述第一会话管理网元所管理的一个或者多个用户面网元中是否存在能与所述目标基站建立连接的用户面网元。
方式3，由移动性管理网元确定连接所述源基站的第一用户面网元是否能与所述目标基站建立连接。
在所述终端接入所述源基站的流程中，第一会话管理网元在选择到所述第一用户面网元后，将该第一用户面网元的信息发送给移动性管理网元。所述第一用户面网元的信息包括所述第一用户面网元的服务区域信息和/或所述第一用户面网元的标识，后续在描述时以第一用户面网元的服务区域信息为例进行说明。从而在移动性管理网元接收到切换请求后，可以根据终端的目标区域信息以及所述第一用户面网元的信息确定终端是否位于所述第一用户面网元的服务区域，若否，则第一用户面网元不能与所述目标基站建立连接。
下面以5G通信网络中AN之间的切换为例进行详细说明，即图2对应的实施例中的移动性管理网元为AMF，会话管理网元为SMF，用户面网元为UPF。
下面实施例一针对上述方式1以及方式2进行详细说明。
实施例一：
参见图4所示，为本申请实施例提供的网元选择的流程示意图。为了描述方便，后续将DN对应的SMF称为ASMF(即对应图2A中的SMF2，切换之前的SMF)，将目标AN(target AN，T-AN)对应的SMF称为ISMF(即对应图2A中的SMF1，新选择的SMF)，同理，将与DN连接的UPF称为AUPF(即S-AN对应的UPF，对应图2A中的UPF2)，将选择的与T-AN相连的UPF称为IUPF。
S401，S-AN(source AN)在确定UE需要从S-AN切换到T-AN(target AN)时，向S-AMF发送切换指示(handover required)。该切换请求中包括协议数据单元(protocol data unit，PDU)会话的标识以及UE的目标区域信息(UE location)，UE的目标区域信息也是目标AN的位置信息或者目标区域对应的小区ID等。PDU会话的标识可以是PDU session ID。
S402，S-AMF在接收到所述切换指示后，S-AMF向T-AMF发送前向重定向请求(forward relocation request)。该前向重定向请求中包括PDU会话的ID以及UE的目标区域信息。
其中，S-AMF服务于S-AN，T-AMF服务于T-AN。
另外，需要说明的是，若S-AN和T-AN均位于同一个AMF的服务区域内，则S-AMF与T-AMF为同一个AMF，本申请实施例中网元选择的流程中不执行S402。
S403，T-AMF向ASMF发送PDU切换请求(handover request)1，该切换请求1包括UE的目标区域信息。
S404，ASMF在接收到切换请求1后，确定所述ASMF所管理的UPF中不存在能与所述T-AN建立连接的UPF。
若ASMF根据UE的目标区域信息确定与S-AN建立连接的UPF1(即AUPF)是否能够与T-AN建立连接，若是，ASMF触发建立T-AN与UPF1之间用户面连接的流程，即ASMF向UPF1发送N4会话更新请求(N4 session update)，此时对应的场景是UPF1能够连接AN，并且分别能够与S-AN、T-AN连接。
若ASMF根据UE的目标区域信息确定UPF1无法与T-AN建立连接，则ASMF确定ASMF所管理的除UPF1以外的其它的UPF是否能够与T-AN建立连接。
若ASMF确定ASMF所管理的除UPF1以外的UPF2能够与T-AN建立连接，则ASMF触发建立T-AN与UPF2之间用户面连接的流程，具体的，ASMF向UPF2发送N4会话更新请求(N4 session update)。
若ASMF确定ASMF所管理的除UPF1以外的其它UPF均不能够与T-AN建立连接，则ASMF所管理的UPF中不存在能与所述T-AN建立连接的UPF。
S405，ASMF向T-AMF发送消息1，该消息1用于触发T-AMF执行选择SMF的操作。消息1可以是PDU切换响应(PDU handover response)1，当然还可以是其他用于触发T-AMF执行选择SMF的操作的消息均适用于本申请实施例，图4中以消息1为PDU切换响应1为例。
ASMF判断在所述ASMF所管理的UPF中不存在能与所述T-AN建立连接的UPF的判断结果可以通过消息1发送给T-AMF。从而T-AMF根据判断结构执行选择SMF的操作。
其中，消息1本身具有通知判断结果的作用，即如果不需要触发T-AMF执行选择SMF的操作，则ASMF不需要给T-AMF发送该消息1，一旦向发送T-AMF发送该消息1，则触发T-AMF执行选择SMF的操作。或者以在消息1中携带指示值(indicator)的形式，比如：indicator＝1标识T-AMF需要执行选择SMF的操作，indicator＝0标识T-AMF不需要执行选择SMF的操作不需要SMF重选)；或者以在消息1中携带原因值的形式通知判断结果，比如，原因值用于表示发送该消息1的原因为：所述ASMF所管理的UPF中不存在能与所述T-AN建立连接的UPF。
可选地，PDU切换响应1还可以携带指示信息，该指示信息用于指示T-AMF执行的动作。动作包括：重选SMF或者新增SMF。
ASMF在确定T-AMF所需执行的动作时，可以通过如下方式：
ASMF根据网络策略来确定T-AMF所需执行的动作，其中，网络策略可以是预先配置在ASMF中的。
网络策略可以包括：执行新增满足的条件和执行重选满足的条件。
比如可以根据业务相关信息对特定的会话执行新增，比如某个会话包括了本地分流的业务，则该会话对应执行新增。其中，数据网络接入标识(data network access identifier，DNAI)或业务标识或数据特征等指示该UE传输的数据对应的业务类型。DNAI可以是在会话创建或更新的过程中，SMF从策略控制网元中获得的，或者DNAI是预先配置在SMF上的。
具体的网络策略中可以包括：执行新增ISMF的动作所对应的数据网络接入标识(data network access identifier，DNAI)，或者执行新增ISMF的动作所对应的业务标识范围、或者执行新增ISMF的动作所对应的数据特征等。
又比如，根据SSC mode信息确定执行新增或者重选。如果SSC mode信息指示要求保持会话连续性，那么作为锚点的UPF(AUPF)就不能变化，则需要新增ISMF；如果不要求保持会话连续性，那么可以重选SMF和UPF。
可选地，该网络策略也可以是预先配置在T-AMF中的，则PDU切换响应1可以不携带上述用于指示T-AMF执行的动作的指示信息。由T-AMF根据网络策略来确定所需执行的动作。
S406，T-AMF接收到ASMF发送的PDU切换响应1后，执行新增或者重选SMF的操作。图4中以执行新增SMF的操作为例。而T-AMF确定重新选择SMF后，执行会话创建或会话更新流程。具体可以参见现有PDU会话的建立或更新或修改流程，此处不再赘述。
T-AMF在确定需要重新选择SMF时，具体可以通过如下方式实现：
一方面，T-AMF根据UE的目标区域信息(比如小区的标识、基站的位置信息等)向NRF(或DNS服务器)查询到一个SMF的可选列表1，以及根据DNN查询得到一个SMF的可选列表2。然后T-AMF先从可选列表2中选择一个SMF作为会话锚点或IP锚点，具体可能根据各个SMF的负载、能力等信息来选择，比如选择的SMF为SMF1。再然后对比SMF与可选列表1，优先在可选列表1中选择与SMF1的标识相同的SMF，如果没有标识相同的SMF，那么将可选列表1包括的SMF的标识与SMF1的标识进行对比，选择和SMF1拓扑最近的SMF。目前SMF的标识根据服务区域来确定，两个SMF的服务区域越接近，则两个SMF的标识越接近。因此，两个SMF拓扑最近，也就是两个SMF的标识最接近。
实际上，选择SMF的最终目标是选择到UPF，其中UPF分别能够与T-AN和DN连接。AMF选择SMF的过程中会考虑SMF的服务区域，SMF的服务区域是与相应的UPF的服务区域范围相关的，比如SMF可以控制多个UPF的情况下，SMF的服务区域会拆分成很多与UPF对应的小服务区域，SMF在选择UPF的时候其实知道SMF的服务区域也就知道UPF的服务区域。所以可以保证选择到一个SMF之后一定可以找到一个UPF能够与T-AN连接。又比如SMF可以管理多个UPF的情况下，SMF的服务区域是多个UPF的服务区域的合集或并集，SMF在选择UPF的时候知道SMF的服务区域也就知道有至少一个UPF的服务区域在这个范围内。所以可以保证选择到一个SMF之后一定可以找到一个UPF能够与T-AN连接。
另一方面，T-AMF也可能同时将UE location和DNN信息发送给DNS服务器(或NRF)，由DNS服务器(或NRF)分别查询得到两个可选列表并选择SMF，并将选择结果返回给T-AMF。若DNS服务器(或NRF)确定有一个SMF能够同时满足UE location和DNN这两个查询条件，则返回该SMF的标识；如果DNS服务器(或NRF)选择到两个SMF，其中一个SMF满足UE location，另一个SMF满足DNN，则返回两个SMF，并指示AMF每个SMF的角色，即指示哪个对应T-AN，作为ISMF，哪个对应DN，作为ASMF(用于连接DN)。
T-AMF在确定需要新增加SMF时，保持当前ASMF，作为会话锚点或IP锚点，具体可以通过如下方式实现：
由于ASMF是根据DNN选择出来的，在PDU会话的保持期间DNN始终保持不变，ASMF始终可以保持与DN之间的连接。只需要再增加一个SMF来保证能选择与T-AN连接的UPF即可。
一方面，T-AMF根据UE的目标区域信息(比如小区标识、基站位置等)向DNS服务器(或NRF)查询到一个SMF的可选列表1，再然后对比ASMF与可选列表1，优先在可选列表1中选择与ASMF的标识相同的SMF，如果没有标识相同的SMF，那么将可选列表1包括的SMF的标识与SMF1的标识进行对比，选择和SMF1拓扑最近的SMF，作为ISMF。
另一方面，T-AMF也可能同时将UE location和ASMF的标识发送给DNS服务器(或NRF)，由DNS服务器(或NRF)查询可选列表1并选择SMF，并将选择结果返回给T-AMF。
可选地，T-AMF接收到ASMF发送的PDU切换响应中还可以包括与S-AN连接的AUPF的标识，如果T-AMF确定需要新增加ISMF，那么可以在选择到新增加的ISMF后，可以将与S-AN连接的AUPF的标识发送给新增加的ISMF，从而新增加的ISMF在选择UPF时，可以根据AUPF的标识选择与AUPF拓扑最近的IUPF。
参见图4所示，以T-AMF执行新增SMF的操作为例。T-AMF在确定新增I-SMF后，进行后续会话更新流程，即更新UE与DN之间的用户面连接。具体包括如下：
S407，T-AMF向ISMF发送PDU切换请求(PDU handover request)2。该PDU切换请求2中可以包括T-AN的隧道信息(T-AN tunnel info)、PDU会话的ID以及ASMF ID等。当I-SMF获得ASMF的信息，比如AMF ID或AMF address之后，可以向AMF发送信令消息。
S408，ISMF在接收到T-AMF发送的PDU切换请求2后，ISMF选择IUPF，然后向IUPF发送N4会话管理请求1，其中N4会话管理请求可以是N4会话建立/修改/更新请求(N4 session establishment/modification/update request)。其中，N4会话管理请求中可以包括PDU会话的ID以及T-AN tunnel info。N4会话管理请求用于指示IUPF建立与T-AN之间的用户面连接。
S409，IUPF在建立与T-AN之间的用户面连接后，向ISMF发送N4会话管理响应1。
其中N4会话管理响应1可以是N4会话建立/修改/更新响应(N4 session establishment/modification/update response)。N4会话管理响应1用于指示IUPF是否成功建立与T-AN之间的用户面连接。
N4会话管理流程中，I-SMF可以获得IUPF的隧道信息，可以包括IUPF与T-AN之间的用户面连接对应的N3隧道信息(N3 tunnel info)，还可以包括IUPF与AUPF之间的N9隧道信息(N9 tunnel info)。N3是UPF与AN之间连接的接口，N9是两个UPF之间的接口，比如IUPF和AUPF。如果隧道信息由SMF分配，那么在S408的N4会话管理请求中由I-SMF将N3隧道信息和N9隧道信息发送给IUPF；如果隧道信息由UPF分配，那么在S409的N4会话管理响应中由IUPF将N3隧道信息和N9隧道信息发送给I-SMF。
S410，ISMF向ASMF发送PDU切换请求3，该PDU切换请求3包括N3的隧道信息(N3 tunnel info)和N9隧道信息、PDU会话的ID。该PDU切换请求3用于指示ASMF建立IUPF与AUPF之间的用户面连接。
S411，ASMF在接收到ISMF发送的PDU切换请求3后，向AUPF发送N4会话管理请求2。其中，N4会话管理请求2中包括PDU会话的ID以及N9 tunnel info。N4会话管理请求2用于指示AUPF建立与IUPF之间的用户面连接。
S412，AUPF在接收到ASMF发送的N4会话管理请求2后，向ASMF发送N4会话管理响应2。N4会话管理响应2用于指示AUPF是否成功建立与IUPF之间的用户面连接。N4会话管理响应2可以包括AUPF的N9 tunnel info。
S413，ASMF向ISMF发送PDU切换响应3，PDU切换响应3包括AUPF的N9 tunnel info。
S414，ISMF在接收到ASMF发送的PDU切换响应3后，向T-AMF发送PDU切换响应2，该PDU切换响应2包括IUPF的N3 tunnel info。
S415，T-AMF在接收到I-SMF发送的PDU切换响应2后，向T-AN发送切换请求，携带IUPF的N3 tunnel info，从而T-AN可以向IUPF发送上行数据。
S416，T-AN在接收到T-AMF发送的切换请求后，确认可以切换的PDU会话信息，向T-AMF发送切换响应。
S417，T-AMF接收到T-AN发送的切换响应后，向I-SMF发送修改PDU请求(modify PDU request)，其中可以包括AUPF的N9 tunnel info。
S418，I-SMF接收到T-AMF发送的修改PDU请求后，向IUPF发送N4会话管理请求3。N4会话修改请求中可以包括AUPF的N9 tunnel info，从而IUPF可以行AUPF发送上行数据。
S419，IUPF接收到I-SMF发送的N4会话管理请求3后，完成PDU会话修改，并向I-SMF发送N4会话管理响应4，其中N4会话管理响应4可以是N4会话修改响应(N4 session modification response)。
S420，I-SMF接收到IUPF发送的N4会话修改响应4后，向T-AMF发送修改PDU响应(modify PDU response)。
S421，T-AMF接收到I-SMF发送的修改PDU响应后，向S-AMF发送前向重定向响应(forward relocation response)，前向重定向响应用于指示成功完成S-AN到T-AN的切换。
上述实施例中，在AMF不能感知UPF的服务区域范围的情况下，在UE移动性导致当前SMF不能选择合适的UPF与目标基站建立连接时，当前SMF可以判断控制范围内是否有与目标基站建立连接的UPF，并将判断结果告知AMF，使得AMF可以重选或者新增SMF，从而新增SMF选择合适的UPF(s)，使得目标基站和DN之间能够建立起用户面连接。具体是通过SMF根据UE的目标区域信息判断当前SMF是否能够选择到与目标基站连接的UPF，如果不能，则通知AMF，由AMF根据判断结果重选或新增SMF，从而重选或者新增的SMF选择到与目标基站连接的UPF。
下面实施例二针对上述方式3进行详细说明。
实施例二：
参见图5所示，为本申请实施例提供的网元选择的流程示意图。为了描述方便，后续将DN对应的SMF称为ASMF，将目标AN(target AN，T-AN)对应的SMF称为ISMF，同理，将与DN连接的UPF称为AUPF(即S-AN对应的UPF)，将选择的与T-AN相连的UPF称为IUPF。
本实施例二的前提是AMF知道与S-AN连接的AUPF的位置信息，比如AUPF的服务区域信息或标识信息(与位置相关)，但是AMF不知道当前ASMF所管理的所有UPF的服务范围信息。
在UE连接S-AN的会话创建流程中，ASMF选择了AUPF之后，可以将该AUPF的位置信息，比如AUPF的服务区域信息(UPF service area)发送给S-AMF。
S501，S-AN在确定UE需要从S-AN切换到T-AN(target AN)时，向S-AMF发送切换指示(handover required)。该切换请求中包括PDU会话的标识以及UE的目标区域信息(UE location)，UE的目标区域信息可以是目标AN的位置信息。PDU会话的标识可以是PDU session ID。
S502，S-AMF在接收到所述切换指示后，S-AMF向T-AMF发送前向重定向请求 (forward relocation request)。该前向重定向请求中包括PDU会话的ID以及UE的目标区域信息。
其中，S-AMF服务于S-AN，T-AMF服务于T-AN。
另外，需要说明的是，若S-AN和T-AN均位于同一个AMF的服务区域内，则S-AMF与T-AMF为同一个AMF，本申请实施例中网元选择的流程中不执行S502。
S-AMF存储了AUPF的服务区域信息，在步骤S502中，S-AMF向T-AMF发送的前向重定向请求中还包括AUPF的服务区域信息。
T-AMF在接收到所述前向重定向请求后，根据UE的目标区域信息以及AUPF的服务区域信息确定UE位于AUPF的服务区域内，则不需要执行更新SMF和UPF的操作。
S503，T-AMF根据UE的目标区域信息以及AUPF的服务区域信息确定UE位于AUPF的服务区域外。
S504，T-AMF向ASMF发送PDU切换请求1(handover request)，该切换请求1包括UE的目标区域信息。该切换请求1中还包括指示信息，该指示信息用于指示UE位于AUPF的服务区域外，即AUPF不能与T-AN建立用户面连接。
该切换请求1还可以包括DNN、会话和业务连续性模式(session and service continuity mode，SSC mode)、切片信息、PDU会话类型、UPF的能力(缓存、本地分流等)、UPF的服务区域、SMF的服务区域等信息中一项或多项。
S505，ASMF在接收到切换请求1后，确定所述ASMF所管理的除AUPF以外的其它UPF中不存在能与所述T-AN建立连接的UPF。具体的确定方式参见实施例一，此处不再赘述。
S506～S522，具体参见图4中S405～S421，此处不再赘述。
上述实施例中，AMF根据UE location和保存的UPF的服务区域信息判断当前UPF是否可以与目标基站连接，并将初始判断结果发送给当前SMF，当前SMF根据初始判断结果执行后续动作。如果初始判断结果为当前UPF可以与目标基站建立连接，那么只需要简单的会话更新；如果初始判断结果为当前UPF不能与目标基站建立连接，那么SMF进一步判断它管理范围内是否有其他可以与目标基站连接的UPF。如果SMF进一步判断结果是可以找到与目标基站连接的UPF则重选或新增UPF并完成会话更新；如果是找不到合适的UPF，那么将判断结果返回给AMF，由AMF新增或重选SMF，该新增或重选的SMF再选择合适的UPF，保证与目标基站的连接。
上述实施例二与实施例一的区别在于：本实施例二经过AMF和SMF两次判断，如果最终SMF判断当前SMF管理范围内没有与目标基站建立连接的UPF，SMF才会通知AMF，由AMF新增或重选SMF，相应地，SMF选择UPF，最终完成基站到DN之间的用户面连接。
参见图6所示，为本申请实施例提供的网元的选择方法流程示意图。该方法应用于不同通信网络中的基站之间的切换。
S601，在终端接入第一通信网络过程中，第一移动性管理网元获取第一会话管理网元的服务区域信息。
在所述终端与所述第一通信网络连接的过程中，由第一会话管理网元为终端提供服务，来满足所述终端与所述第一通信网络建立用户面连接。
S602，在终端由所述第一通信网络切换到第二通信网络的过程中，所述第一移动性管理网元向第二移动性管理网元发送第一消息。其中，所述第一消息包括所述第一会话管理网元的服务区域信息，以便于所述第二移动性管理网元根据所述第一会话管理网元的服务区域信息，确定是否选择第二会话管理网元。
确定是否选择第二会话管理网元，也就是确定在所述终端从所述第一通信网络切换到第二通信网络后，是否需要由第二会话管理网元为终端提供服务，来满足所述终端与所述第二通信网络建立用户面连接。
其中，第一移动性管理网元为第一通信网络对应的移动性管理网元，第二移动性管理网元为第二通信网络对应的移动性管理网元。
S603，所述第二移动性管理网元从第一移动性管理网元接收第一消息。
S604，所述第二移动性管理网元根据所述第一会话管理网元的服务区域信息，确定是否选择第二会话管理网元。
上述方案，提供了一种在不同的通信网络中基站间的切换过程中如何决定选择第二会话管理网元的方式。比如：终端由4G切换到5G，MME在终端接入4G时，获取服务于终端连接4G过程中的第一会话管理网元(比如与PGW-C部署在同一设备的SMF)的服务区域信息，从而在终端由4G网络切换到5G网络时，MME将该第一会话管理网元的服务区域信息通知到AMF，从而AMF能够确定该第一会话管理网元的服务区域信息是否也能够服务于终端连接5G的过程中，进而确定是否需要执行选择其他会话管理网元的操作。
可选地，所述第一消息还可以包括所述终端的位置信息。终端的位置信息也就是终端所在的目标区域信息。
所述第二移动性管理网元根据所述第一会话管理网元的服务区域信息，确定是否选择第二会话管理网元，具体可以通过如下方式实现：
在根据所述终端的位置信息和所述第一会话管理网元的服务区域信息，确定所述终端不在所述第一会话管理网元的服务区域内时，所述第二移动性管理网元确定选择所述第二会话管理网元；或者，
在根据所述终端的位置信息和所述第一会话管理网元的服务区域信息，确定所述终端在所述第一会话管理网元的服务区域内时，所述第二移动性管理网元确定不选择所述第二会话管理网元。
下面实施例三以位于源区域的4G通信网络的基站(eNB)切换到位于目标区域的5G通信网络的基站(AN)为例进行详细说明。第一移动性管理网元为MME，第二移动性管理网元为AMF。会话管理网元为PGW-C与SMF融合部署的网元(即PGW-C+SMF)。用户面网元为PGW-U与UPF融合部署的网元(PGW-U+UPF)。
作为本实施例三的前提，在4G创建会话的过程中，比如附着流程(attach procedure)中，MME可以获取PGW-C(SMF)的服务区域信息。PGW-C(SMF)的服务区域信息可以是PGW-C(SMF)的标识，或者是PGW-C(SMF)的服务区域范围等。合一部署的PGW-C和SMF的服务区域可能相同也可能不同，如果相同，则所述服务区域信息既是PGW-C也是SMF的服务区域；如果不同，则所述服务区域信息是SMF的服务区域。
参见图7所示，为获取(PGW-C+SMF)的服务区域信息的流程示意图。
S701，UE向eNB发送附着请求(attach request)。
S702，eNB接收到UE发送的attach request后，将所述attach request转发给MME。 attach request中包括UE的目标区域信息(UE location)。
S703，MME接收到attach request后，执行SGW-C和PGW-C(即SMF)的选择。
具体的，MME根据UE location向DNS服务器查询获得一个SGW-C列表，根据接入点名称(Access Point Name，APN)向DNS服务器查询获得一个PGW-C列表，然后先在PGW-C列表中(可能会依赖于网元的负载、能力等信息)确定一个PGW-C之后，然后对比选择的PGW-C与SGW-C列表，优先从SGW-C列表中选择与选择的SGW-CIP地址相同的SGW-C，如果IP地址相同的，那么对比选择的PGW-C IP地址与SGW-C列表中的SGW-C的IP地址选择和PGW-C拓扑近的SGW-C。
实际上，选择SGW-C和PGW-C的最终目标是选择到对应的SGW-U和PGW-U，其中SGW-U能够与基站连接，PGW-U能够与数据网络DN连接。MME选择SGW-C和PGW-C的过程中会考虑SGW-C和PGW-C的服务区域，这个SGW-C和PGW-C的服务区域是与相应的用户面的服务区域范围相关的，比如SGW-C可以控制多个SGW-U的情况下，SGW-C的服务区域会拆分成很多与SGW-U对应的小服务区域，MME在选择SGW-C的时候如果知道SGW-C的服务区域，也就知道SGW-U的服务区域。所以可以保证选择到一个SGW-C之后一定可以找到一个SGW-U能够与基站连接。
S704，MME向选择的SGW-C发送创建会话请求1(creat session request1)。
S705，SGW-C在接收到所述MME发送的创建会话请求1后，向选择的PGW-C(即SMF)发送所述创建会话请求2，所述创建会话请求2用于指示SGW-C建立用户面连接。
S706，PGW-C在接收到所述创建会话请求2后，PGW-C选择PGW-U(UPF)，并向选择的PGW-U发送会话建立请求(session establishment request)。
S707，PGW-U在接收到会话建立请求后，创建用户面连接，并向所述PGW-C发送会话建立响应(session establishment request)。
S708，PGW-C接收到session establishment request后，向SGW-C发送创建会话响应2(creat session response2)。其中，PGW-C可以将本身(SMF)的服务区域信息携带在creat session response2中发送给SGW-C。
S709，SGW-C将creat session response2转发给MME。MME在收到SMF的服务区域信息后，保存下来。
S710，MME向eNB发送初始化上下文建立请求(initial context setup request)。
S711，eNB与UE之间完成RRC连接重配置。
S712，eNB向MME发送附着完成消息(attach complete)。
上述流程中，MME通过在创建会话响应消息获取到PGW-C(SMF)的服务区域信息。
可选地，MME选择到PGW-C时，即执行步骤S703时，MME可以向DNS服务器获取该PGW-C(SMF)的服务区域信息。
在MME获取PGW-C(SMF)的服务区域信息后，且UE由4G通信网络的基站(eNB)切换到5G通信网络的基站(AN)过程中，MME将PGW-C(SMF)的服务区域信息发送给AMF，从而AMF可以根据该PGW-C(SMF)的服务区域信息确定是否需要再选择SMF来保证UE与数据网络之间的用户面连接。
参见图8所示，为UE由4G通信网络的基站(eNB)切换到5G通信网络的基站(AN)的流程示意图。为了描述方便，后续将4G通信网络对应的SMF(PGW-C)称为ASMF，将AN对应的SMF称为ISMF，同理，将与DN连接的UPF(PGW-U)称为AUPF((即 eNB对应的UPF))，将选择的与AN相连的UPF称为IUPF。
S801，eNB在确定UE需要从eNB切换到AN时，向MME发送切换指示(handover required)。该切换请求中包括AN的标识、AMF的标识以及UE的目标区域信息(UE location)。UE的目标区域信息可以是目标AN的位置信息，或者UE所在的位置信息，或者是UE所在的位置对应的目标小区的标识等。
S802，MME在接收到所述handover required后，向AMF发送前向重定向请求(forward relocation request)。该forward relocation request中包括UE location以及ASMF的服务区域信息。该forward relocation request中还可以包括AN的标识、会话上下文、承载上下文(包括ASMF的address)。
S803，AMF接收到forward relocation request后，根据ASMF的服务区域信息确定是否需要选择第二会话管理网元。
具体的，若确定UE不在ASMF的服务区域内，则AMF确定需要选择ISMF，即执行选择操作。若确定UE在ASMF的服务区域内，则AMF不执行选择ISMF的操作。
AMF中可以配置网络策略，AMF在确定需要选择ISMF时，可以根据网络策略确定执行新增ISMF或者重新选择ISMF来替换原来ASMF。具体确定的方式可以参见实施例一中的描述，此处不再赘述。
在确定执行新增ISMF时，执行S804。而AMF确定重新选择ISMF后，执行建立UE与DN之间的PDU会话的过程，具体可以参见现有PDU会话的建立流程，此处不再赘述。
S804，AMF向选择的ISMF发送PDU会话管理请求1。
ISMF可以根据PDU会话更新请求1中获得ASMF的地址，从而可以与ASMF之间进行信令交互。其中，PDU会话管理请求可以是PDU会话建立/更新/修改请求(PDU session establishment/update/modification request)。比如PDU会话更新请求可以是Nsmf_PDU sesseion_update SMC Context request。该PDU会话更新请求1中包括承载上下文(bearer context)信息。bearer context中包括PGW-C(即ASMF)的地址信息(address)。
S805，ISMF在接收到AMF发送的PDU会话管理请求1后，向ASMF(PGW-C)发送PDU会话管理请求2。
S806，ASMF在接收到所述PDU会话管理请求2后，根据所述bearer context与PGW-U(即AUPF)之间执行N4接口对应的会话修改。
S807，ASMF向ISMF发送PDU会话更新响应2，PDU会话更新响应2用于向ISMF发送一些ASMF预先获得的会话信息。其中，PDU会话管理响应可以是PDU会话建立/更新/修改响应(PDU session establishment/update/modification response)。比如PDU会话管理响应可以是Nsmf_PDU sesseion_update SMC Context response。PDU会话管理响应中包括AUPF的隧道信息(A-CN tunnel info)。PDU会话管理响应中还包括移动性管理网元不感知的会话管理信息(比如N2 SM information)以及PDU会话的标识等。移动性管理网元不感知的会话管理信息还可以包括服务质量(quality of service，QoS)配置(profile)。
S808，ISMF在接收到所述PDU会话更新响应2后，根据所述AUPF的隧道信息以及N2 SM information，控制IUPF建立IUPF与AUPF之间的隧道以及IUPF与AN之间隧道。
S809，ISMF向AMF发送所述PDU会话管理响应1。所述PDU会话管理响应1中包括IUPF与AUPF之间的隧道的信息(N9 tunnel info)以及IUPF与AN之间隧道的信息(N3 tunnel info)。N9 tunnel info和N3 tunnel info统称为I-CN tunnel info。
S810，AMF接收到所述ISMF发送的PDU会话管理响应1后，向AN发送切换请求(handover request)。该handover request中包括I-CN tunnel info。
S811，AN接收到handover request后，向AMF发送切换请求确认(handover request ACK)。在handover request ACK中包括AN隧道信息(AN tunnel info)。
S812，AMF接收到handover request ACK后，向ISMF发送PDU会话管理请求3。PDU会话管理请求指示ISMF为需要切换的会话创建间接转发隧道。比如PDU会话更新请求3可以是Nsmf_PDU sesseion_update SMC Context request。该PDU会话更新请求3中包括中间转发隧道的AN tunnel info。
S813，ISMF在接收到AMF发送的PDU会话管理请求3后，执行ISMF和IUPF之间的N4会话管理流程，并在N4会话管理流程中将所述AN tunnel info发送给IUPF，从而IUPF获得AN的隧道信息，控制IUPF建立IUPF与AN之间隧道。此外，在ISMF和IUPF之间的N4会话管理流程中，ISMF和IUPF获得IUPF的中间转发隧道的N3隧道信息和N9隧道信息。
S814，ISMF向ASMF发送所述PDU会话管理请求4，该PDU会话管理请求中包括IUPF的中间转发隧道的N9 tunnel info。
S815，ASMF接收到所述PDU会话管理请求后，向AUPF发送N4会话管理请求，比如N4 session modification request。该N4 session modification request中包括IUPF的中间转发隧道的N9 tunnel info。
S816，AUPF接收到所述N4 session modification request后，向ASMF发送N4会话管理响应，比如N4 session modification response。该N4 session modification request中包括A-CN tunnel info。
S817，ASMF向ISMF发送PDU会话管理响应4。比如PDU会话管理响应4是PDU会话管理请求3对应的确认消息，比如可以是Nsmf_PDU sesseion_update SMC Context response。PDU会话管理响应4中包括A-CN tunnel info。
S818，ISMF向AMF发送所述PDU会话管理响应4。所述PDU会话管理响应4中包括A-CN tunnel info。
S819，AMF接收到所述ISMF发送的PDU会话更新响应4后，向MME发送前向重定向响应。前向重定向响应中包括A-CN tunnel info。
S820，MME向SGW发送创建间接数据转发隧道请求，用于通知SGW需要进行间接数据转发，同时，告知SGW间接转发的上行目的隧道信息。比如创建间接数据转发隧道请求是createindiret data forwarding tunnel request，该创建间接数据转发隧道请求包括A-CN tunnel info，需要间接转发的数据上行发送到SGW之后向A-CN tunnel info所指示的AUPF发送。
S821，SGW-C向MME发送创建间接数据转发隧道响应，比如是createindiret data forwarding tunnel response(包括SGW tunnel info)。
另外需要说明的是，本申请实施例中涉及到的消息名称仅作为一种示例，并不对消息名称进行具体限定。
上述实施例，提供了一种在不同的通信网络中基站间的切换过程中如何决定选择第二会话管理网元的方式，并详细说明了具体的切换流程。比如：终端由4G切换到5G，MME在终端接入4G时，获取服务于终端连接4G过程中的第一会话管理网元的服务区域信息， 从而在终端由4G切换到5G时，MME将该第一会话管理网元的服务区域信息通知到AMF，从而AMF能够确定该第一会话管理网元的服务区域信息是否也能够服务于终端连接5G的过程中，进而确定是否需要执行选择其他会话管理网元的操作，如果确定选择，保证了再选择的其它会话管理网元的控制范围内的用户面网元存在与目标基站建立连接的用户面网元，从而UE能够通过目标基站与DN建立连接进行数据传输，避免了由于源基站的第一会话管理网元无法服务于目标基站导致的数据传输中断。
基于与方法实施例同样的发明构思，本申请实施例还提供了一种装置，该装置900应用于会话管理网元。该装置900具体可以是会话管理网元中的处理器，或者芯片或者芯片系统，或者是一个功能模块等。该装置可以包括接收单元901、处理单元902、发送单元903。处理单元902用于对装置900的动作进行控制管理。其中接收单元901用于执行S302，处理单元902用于执行S303，发送单元903用于执行S304，重复之处，此处不再赘述。处理单元902还可以用于指示上述任意实施例中涉及会话管理网元(SMF或者PGW-C)的处理过程和/或本申请所描述的技术方案的其他过程。
本申请实施例还提供另外一种会话管理网元的结构，如图10所示，会话管理网元1000中可以包括通信接口1010、处理器1020。可选的，会话管理网元1000中还可以包括存储器1030。其中，存储器1030可以设置于会话管理网元内部，还可以设置于会话管理网元外部。上述图9中所示的、处理单元902均可以由处理器1020实现。接收单元901、发送单元903可以由通信接口1010实现。处理器1020通过通信接口1010接收信息或者消息，并用于实现图3～图8中所述的会话管理网元(SMF或者PGW-C)所执行的方法。在实现过程中，处理流程的各步骤可以通过处理器1020中的硬件的集成逻辑电路或者软件形式的指令完成图3～图8中所述的会话管理网元所执行的方法。
本申请实施例中通信接口1010可以是电路、总线、收发器或者其它任意可以用于进行信息交互的装置。其中，示例性地，该其它装置可以是与该会话管理设备1000相连的设备，比如，该其它装置可以是AMF或者UPF等。
本申请实施例中处理器1020可以是通用处理器、数字信号处理器、专用集成电路、现场可编程门阵列或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件，可以实现或者执行本申请实施例中的公开的各方法、步骤及逻辑框图。通用处理器可以是微处理器或者任何常规的处理器等。结合本申请实施例所公开的方法的步骤可以直接体现为硬件处理器执行完成，或者用处理器中的硬件及软件单元组合执行完成。处理器1020用于实现上述方法所执行的程序代码可以存储在存储器1030中。存储器1030和处理器1020耦合。
本申请实施例中的耦合是装置、单元或模块之间的间接耦合或通信连接，可以是电性，机械或其它的形式，用于装置、单元或模块之间的信息交互。
处理器1020可能和存储器1030协同操作。存储器1030可以是非易失性存储器，比如硬盘(hard disk drive，HDD)或固态硬盘(solid-state drive，SSD)等，还可以是易失性存储器(volatile memory)，例如随机存取存储器(random-access memory，RAM)。存储器1030是能够用于携带或存储具有指令或数据结构形式的期望的程序代码并能够由计算机存取的任何其他介质，但不限于此。
本申请实施例中不限定上述通信接口1010、处理器1020以及存储器1030之间的具体连接介质。本申请实施例在图10中以存储器1030、处理器1020以及通信接口1010之间 通过总线连接，总线在图10中以粗线表示，其它部件之间的连接方式，仅是进行示意性说明，并不引以为限。所述总线可以分为地址总线、数据总线、控制总线等。为便于表示，图10中仅用一条粗线表示，但并不表示仅有一根总线或一种类型的总线。
基于与上述方法实施例同样的发明构思，本申请实施例还提供了一种装置。参见图11所示，该装置1100应用于移动性管理网元。该装置具体可以是移动性管理网元中的处理器，或者芯片或者芯片系统，或者是一个功能模块等。
参见图11所示，所述装置可以包括通信单元1101、处理单元1102。通信单元1101包括发送单元和接收单元。该装置可以应用图3～图5所示的实施例中的移动性管理网元，比如AMF，则通信单元1101用于执行S301、处理单元1102用于执行S305，处理单元1102还可以用于执行图3～图5所示的实施例中涉及移动性管理网元的处理过程和/或本申请所描述的技术方案的其他过程。该装置可以应用图6～图8所示的实施例中的第一移动性管理网元，比如MME，则通信单元1101用于执行S602，处理单元1102用于执行S601，或者执行图6～图8所示的实施例中涉及第一移动性管理网元(MME)的处理过程和/或本申请所描述的技术方案的其他过程。该装置还可以应用图6～图8所示的实施例中的第二移动性管理网元，比如AMF，则通信单元1101用于执行S603，处理单元1102用于执行S604，或者执行图6～图8所示的实施例中涉及第二移动性管理网元(AMF)的处理过程和/或本申请所描述的技术方案的其他过程。
本申请实施例还提供另外一种移动性管理网元的结构，如图12所示，移动性管理网元1200中可以包括通信接口1210、处理器1220。移动性管理网元1200中还可以包括存储器1230。存储器1230可以设置于移动管理网元内部，还可以设置于移动管理网元外部。上述图11中所示的处理单元1102可以由处理器1220实现。通信单元1101可以由通信接口1210实现。处理器1220通过通信接口1210接收业务数据，并用于实现图3～图8中所述的任一移动性管理网元(比如MME或者AMF)所执行的方法。在实现过程中，处理流程的各步骤可以通过处理器1220中的硬件的集成逻辑电路或者软件形式的指令完成图3～图8中所述的任一移动性管理网元所执行的方法。
本申请实施例中通信接口1210可以是电路、总线、收发器或者其它任意可以用于进行信息交互的装置。其中，示例性地，该其它装置可以是与该移动性管理网元1200相连的设备，比如，该其它装置可以是AN或者UE等。
本申请实施例中处理器1220可以是通用处理器、数字信号处理器、专用集成电路、现场可编程门阵列或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件，可以实现或者执行本申请实施例中的公开的各方法、步骤及逻辑框图。通用处理器可以是微处理器或者任何常规的处理器等。结合本申请实施例所公开的方法的步骤可以直接体现为硬件处理器执行完成，或者用处理器中的硬件及软件单元组合执行完成。处理器1220用于实现上述方法所执行的程序代码可以存储在存储器1230中。存储器1230和处理器1220耦合。处理器1220可能和存储器1230协同操作。存储器1230可以是非易失性存储器，比如硬盘(hard disk drive，HDD)或固态硬盘(solid-state drive，SSD)等，还可以是易失性存储器(volatile memory)，例如随机存取存储器(random-access memory，RAM)。存储器1230是能够用于携带或存储具有指令或数据结构形式的期望的程序代码并能够由计算机存取的任何其他介质，但不限于此。
本申请实施例中不限定上述通信接口1210、处理器1220以及存储器1230之间的具体 连接介质。本申请实施例在图12中以存储器1230、处理器1220以及通信接口1210之间通过总线连接，总线在图12中以粗线表示，其它部件之间的连接方式，仅是进行示意性说明，并不引以为限。所述总线可以分为地址总线、数据总线、控制总线等。为便于表示，图12中仅用一条粗线表示，但并不表示仅有一根总线或一种类型的总线。
基于以上实施例，本申请实施例还提供了一种计算机存储介质，该存储介质中存储软件程序，该软件程序在被一个或多个处理器读取并执行时可实现上述任意一个或多个实施例提供的方法。所述计算机存储介质可以包括：U盘、移动硬盘、只读存储器、随机存取存储器、磁碟或者光盘等各种可以存储程序代码的介质。
基于以上实施例，本申请实施例还提供了一种芯片，该芯片包括处理器，用于实现上述任意一个或多个实施例所涉及的功能，例如获取或处理上述方法中所涉及的信息或者消息。可选地，所述芯片还包括存储器，所述存储器，用于处理器所执行必要的程序指令和数据。该芯片，可以由芯片构成，也可以包含芯片和其他分立器件。
本申请提供的实施例中，在UE从源基站移动到目标基站的服务区域时，服务于源基站的第一会话管理网元选择的用户面可能仅能与DN建立连接，而可能无法与目标基站建立连接，通过上述方案，由服务于源基站的第一会话管理网元确定其控制下的多个用户面网元中是否存在能够与目标基站建立连接的用户面网元，如果不存在，通知到移动性管理网元，从而移动性管理网元能够再选择其它会话管理网元，来保证再选择的其它会话管理网元的控制范围内的用户面网元存在与目标基站建立连接的用户面网元，从而UE能够通过目标基站与DN建立连接进行数据传输，避免了由于源基站的第一会话管理网元无法服务于目标基站导致的数据传输中断。
本领域内的技术人员应明白，本申请的实施例可提供为方法、系统、或计算机程序产品。因此，本申请可采用完全硬件实施例、完全软件实施例、或结合软件和硬件方面的实施例的形式。而且，本申请可采用在一个或多个其中包含有计算机可用程序代码的计算机可用存储介质(包括但不限于磁盘存储器、CD-ROM、光学存储器等)上实施的计算机程序产品的形式。
本申请是参照根据本申请的方法、设备(系统)、和计算机程序产品的流程图和/或方框图来描述的。应理解可由计算机程序指令实现流程图和/或方框图中的每一流程和/或方框、以及流程图和/或方框图中的流程和/或方框的结合。可提供这些计算机程序指令到通用计算机、专用计算机、嵌入式处理机或其他可编程数据处理设备的处理器以产生一个机器，使得通过计算机或其他可编程数据处理设备的处理器执行的指令产生用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的装置。
这些计算机程序指令也可存储在能引导计算机或其他可编程数据处理设备以特定方式工作的计算机可读存储器中，使得存储在该计算机可读存储器中的指令产生包括指令装置的制造品，该指令装置实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能。
这些计算机程序指令也可装载到计算机或其他可编程数据处理设备上，使得在计算机或其他可编程设备上执行一系列操作步骤以产生计算机实现的处理，从而在计算机或其他可编程设备上执行的指令提供用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的步骤。
显然，本领域的技术人员可以对本申请进行各种改动和变型而不脱离本申请的范围。 这样，倘若本申请的这些修改和变型属于本申请权利要求及其等同技术的范围之内，则本申请也意图包含这些改动和变型在内。

Claims (35)

  1. 一种网元的选择方法，其特征在于，包括：
    第一会话管理网元从移动性管理网元接收第一消息，所述第一消息用于指示终端从源区域切换到目标区域；
    所述第一会话管理网元确定所述第一会话管理网元所管理的用户面网元中是否存在能与所述目标区域的基站建立连接的用户面网元；
    当确定不存在能与所述目标区域的基站建立连接的用户面网元时，所述第一会话管理网元向所述移动性管理网元发送第二消息，所述第二消息用于触发所述移动性管理网元执行选择第二会话管理网元的操作。
  2. 如权利要求1所述的方法，其特征在于，所述第一消息中包括所述终端的目标区域信息，所述第一会话管理网元确定所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元，包括：
    所述第一会话管理网元根据所述终端的目标区域信息，和所述第一会话管理网元所管理的一个或者多个用户面网元的服务区域信息，确定所述终端不在所述第一会话管理网元所管理的任一用户面网元的服务区域内，则确定所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元；或者，
    所述第一会话管理网元根据所述终端的目标区域信息，和所述第一会话管理网元的服务区域信息，确定所述终端不在所述第一会话管理网元所管理的任一用户面网元的服务区域内，则确定所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元。
  3. 如权利要求1所述的方法，其特征在于，所述第一消息中包括所述终端的目标区域信息以及所述终端的会话管理信息，所述第一会话管理网元确定所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元，包括：
    所述第一会话管理网元根据所述终端的目标区域信息，和所述第一会话管理网元所管理的一个或者多个用户面网元的服务区域信息，确定所述终端位于所述第一会话管理网元所管理的至少一个用户面网元的服务区域内；所述第一会话管理网元根据所述终端的会话管理信息确定所述至少一个用户面网元不能与所述目标区域的基站建立连接；或者，
    所述第一会话管理网元根据所述终端的目标区域信息，和所述第一会话管理网元的服务区域信息，确定所述终端位于所述第一会话管理网元所管理的至少一个用户面网元的服务区域内；所述第一会话管理网元根据所述终端的会话管理信息确定所述至少一个用户面网元不能与所述目标区域的基站建立连接。
  4. 如权利要求1～3任一项所述的方法，其特征在于，所述第一会话管理网元确定所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元，包括：
    所述第一会话管理网元确定连接所述源区域的基站的第一用户面网元不能与所述目标区域的基站建立连接，且确定所述第一会话管理网元管理的除所述第一用户面网元以外的用户面网元均不能与所述目标区域的基站建立连接。
  5. 如权利要求4所述的方法，其特征在于，所述第一消息还包括第一指示信息，所述第一指示信息用于指示所述第一用户面网元不能与所述目标区域的基站建立连接；
    所述第一会话管理网元确定所述第一用户面网元不能与所述目标区域的基站建立连接，包括：
    所述第一会话管理网元基于第一指示信息确定所述第一用户面网元不能与所述目标区域的基站建立连接。
  6. 如权利要求1～5任一项所述的方法，其特征在于，所述第二消息用于通知所述移动性管理网元在所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元；或者，
    所述第二消息包括第二指示信息，所述第二指示信息用于指示所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元。
  7. 如权利要求1～6任一项所述的方法，其特征在于，所述第一消息包括第三指示信息，所述第三指示信息用于指示所述移动性管理网元在保持所述第一会话管理网元为所述终端服务的基础上，执行增加所述第二会话管理网元的操作；或者，
    所述第三指示信息用于指示所述移动性管理网元执行重新选择所述第二会话管理网元的操作。
  8. 如权利要求1～7任一项所述的方法，其特征在于，所述第二消息中包括所述第一用户面网元的标识。
  9. 一种网元的选择方法，其特征在于，包括：
    移动性管理网元向第一会话管理网元发送第一消息，所述第一消息用于指示终端由源区域切换到目标区域；
    移动性管理网元接收所述第一会话管理网元发送的第二消息，所述第二消息用于指示所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元；
    所述移动性管理网元根据所述第二消息选择第二会话管理网元，以便于所述第二会话管理网元选择与所述目标区域的基站建立连接的用户面网元。
  10. 如权利要求9所述的方法，其特征在于，移动性管理网元向第一会话管理网元发送第一消息之前，所述方法还包括：
    所述移动性管理网元根据连接所述源区域的基站的第一用户面网元的信息，确定所述第一用户面网元不能与所述目标区域的基站建立连接；所述第一用户面网元的信息由所述第一会话管理网元在所述终端接入所述源区域的基站的流程中发送给所述移动性管理网元，所述第一用户面网元的信息包括所述第一用户面网元的服务区域信息和/或所述第一用户面网元的标识；
    所述移动性管理网元向所述第一会话管理网元发送的第一消息中还包括第一指示信息，所述第一指示信息用于指示所述第一用户面网元不能与所述目标区域的基站建立连接。
  11. 如权利要求9或10所述的方法，其特征在于，所述第二消息用于通知所述第一会话管理网元在所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元；或者，
    所述第二消息包括第二指示信息，所述第二指示信息用于指示所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元。
  12. 如权利要求9～11任一项所述的方法，其特征在于，所述第一消息包括第三指示信息，所述第三指示信息用于指示所述移动性管理网元执行在保持所述第一会话管理网元 为所述终端服务的基础上，增加为所述终端服务的会话管理网元的操作；或者，所述第三指示信息用于指示所述移动性管理网元执行重新选择为所述终端服务的会话管理网元的操作。
  13. 如权利要求9～12任一项所述的方法，其特征在于，所述第一消息中包括连接所述源区域的基站的第一用户面网元的标识；
    所述移动性管理网元根据所述第二消息选择第二会话管理网元后，所述方法还包括：
    所述移动性管理网元向所述第二会话管理网元发送所述第一用户面网元的标识，以使得所述第二会话管理网元选择的第二用户面网元分别能够所述目标区域的基站以及所述第一用户面网元建立连接。
  14. 一种装置，其特征在于，所述装置应用第一会话管理网元，包括：
    接收单元，用于从移动性管理网元接收第一消息，所述第一消息用于指示终端从源区域切换到目标区域；
    处理单元，用于确定所述第一会话管理网元所管理的用户面网元中是否存在能与所述目标区域的基站建立连接的用户面网元；
    发送单元，用于当所述处理单元确定不存在能与所述目标区域的基站建立连接的用户面网元时，向所述移动性管理网元发送第二消息，所述第二消息用于触发所述移动性管理网元执行选择第二会话管理网元的操作。
  15. 如权利要求14所述的装置，其特征在于，所述第一消息中包括所述终端的目标区域信息，所述处理单元，具体用于：
    根据所述终端的目标区域信息和所述第一会话管理网元所管理的一个或者多个用户面网元的服务区域信息，确定所述终端不在所述第一会话管理网元所管理的任一用户面网元的服务区域内，则确定所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元；或者，
    根据所述终端的目标区域信息，和所述第一会话管理网元的服务区域信息，确定所述终端不在所述第一会话管理网元所管理的任一用户面网元的服务区域内，则确定所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元。
  16. 如权利要求14所述的装置，其特征在于，所述第一消息中包括所述终端的目标区域信息以及所述终端的会话管理信息，所述处理单元具体用于：
    根据所述终端的目标区域信息和所述第一会话管理网元所管理的一个或者多个用户面网元的服务区域信息，确定所述终端位于所述第一会话管理网元所管理的至少一个用户面网元的服务区域内；所述第一会话管理网元根据所述终端的会话管理信息确定所述至少一个用户面网元不能与所述目标区域的基站建立连接；或者，
    所述第一会话管理网元根据所述终端的目标区域信息，和所述第一会话管理网元的服务区域信息，确定所述终端位于所述第一会话管理网元所管理的至少一个用户面网元的服务区域内；所述第一会话管理网元根据所述终端的会话管理信息确定所述至少一个用户面网元不能与所述目标区域的基站建立连接。
  17. 如权利要求14～16任一项所述的装置，其特征在于，所述处理单元，具体用于：
    确定连接所述源区域的基站的第一用户面网元不能与所述目标区域的基站建立连接，且确定所述第一会话管理网元管理的除所述第一用户面网元以外的用户面网元均不能与 所述目标区域的基站建立连接。
  18. 如权利要17所述的装置，其特征在于，所述第一消息还包括第一指示信息，所述第一指示信息用于指示所述第一用户面网元不能与所述目标区域的基站建立连接；
    所述处理单元，在确定所述第一用户面网元不能与所述目标区域的基站建立连接时，具体用于基于第一指示信息确定所述第一用户面网元不能与所述目标区域的基站建立连接。
  19. 如权利要求14～18任一项所述的装置，其特征在于，所述第二消息用于通知所述移动性管理网元在所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元；或者，
    所述第二消息包括第二指示信息，所述第二指示信息用于指示所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元。
  20. 如权利要求14～19任一项所述的装置，其特征在于，所述第一消息包括第三指示信息，所述第三指示信息用于指示所述移动性管理网元在保持所述第一会话管理网元为所述终端服务的基础上，执行增加所述第二会话管理网元的操作；或者，
    所述第三指示信息用于指示所述移动性管理网元执行重新选择所述第二会话管理网元的操作。
  21. 如权利要求14～20任一项所述的装置，其特征在于，所述第二消息中包括所述第一用户面网元的标识。
  22. 一种装置，其特征在于，包括：
    发送单元，用于向第一会话管理网元发送第一消息，所述第一消息用于指示终端由源区域切换到目标区域；
    接收单元，用于接收所述第一会话管理网元发送的第二消息，所述第二消息用于指示所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元；
    处理单元，用于根据所述第二消息选择第二会话管理网元，以便于所述第二会话管理网元选择与所述目标区域的基站建立连接的用户面网元。
  23. 如权利要求22所述的装置，其特征在于，所述处理单元，还用于在所述发送单元向第一会话管理网元发送第一消息之前，根据连接所述源区域的基站的第一用户面网元的信息，确定所述第一用户面网元不能与所述目标区域的基站建立连接；所述第一用户面网元的服务区域信息由所述第一会话管理网元在所述终端接入所述源区域的基站的流程中发送给所述移动性管理网元，所述第一用户面网元的信息包括所述第一用户面网元的服务区域信息和/或所述第一用户面网元的标识；
    所述发送单元向所述第一会话管理网元发送的第一消息中还包括第一指示信息，所述第一指示信息用于指示所述第一用户面网元不能与所述目标区域的基站建立连接。
  24. 如权利要求22或23所述的装置，其特征在于，所述第二消息用于通知所述第一会话管理网元在所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元；或者，
    所述第二消息包括第二指示信息，所述第二指示信息用于指示所述第一会话管理网元所管理的用户面网元中不存在能与所述目标区域的基站建立连接的用户面网元。
  25. 如权利要求22～24任一项所述的装置，其特征在于，所述第一消息包括第三指示 信息，所述第三指示信息用于指示所述移动性管理网元执行在保持所述第一会话管理网元为所述终端服务的基础上，增加为所述终端服务的会话管理网元的操作；或者，所述第三指示信息用于指示所述移动性管理网元执行重新选择为所述终端服务的会话管理网元的操作。
  26. 如权利要求22～25任一项所述的装置，其特征在于，所述第一消息中包括连接所述源区域的基站的第一用户面网元的标识；
    所述发送单元，还用于在所述处理单元根据所述第二消息选择第二会话管理网元后，向所述第二会话管理网元发送所述第一用户面网元的标识，以使得所述第二会话管理网元选择的第二用户面网元分别能够所述目标区域的基站以及所述第一用户面网元建立连接。
  27. 一种装置，其特征在于，包括处理器和存储器，所述存储器中存储有计算机程序，所述处理器读取并执行所述存储器中存储的计算机程序时，使得所述通信装置实现权利要求1至8中任意一项所述的方法。
  28. 一种装置，其特征在于，包括处理器和存储器，所述存储器中存储有计算机程序，所述处理器读取并执行所述存储器中存储的计算机程序时，使得所述通信装置实现权利要求9至13中任意一项所述的方法。
  29. 一种芯片系统，其特征在于，包括：所述芯片系统包括至少一个处理器，和接口电路，所述接口电路和所述至少一个处理器通过线路互联，所述处理器通过运行指令，以执行权利要求1至8中任意一项所述的方法。
  30. 一种芯片系统，其特征在于，包括：所述芯片系统包括至少一个处理器，和接口电路，所述接口电路和所述至少一个处理器通过线路互联，所述处理器通过运行指令，以执行权利要求9至13中任意一项所述的方法。
  31. 一种装置，用于执行权利要求1至8中任意一项所述的方法。
  32. 一种装置，用于执行权利要求9至13中任意一项所述的方法。
  33. 一种包含指令的计算机程序产品，当其在计算机上运行时，使得计算机执行上述权利要求1至13中任意一项所述的方法。
  34. 一种计算机可读存储介质，其特征在于，所述计算机可读存储介质中存储有程序或指令，当其在计算机上运行时，使得计算机执行如权利要求1至13中任意一项所述的方法。
  35. 一种通信系统，其特征在于，包括如权利要求14-21任一项所述的装置，和，如权利要求22至26中任一项所述的装置。
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021137180A1 (en) * 2019-12-30 2021-07-08 Telefonaktiebolaget Lm Ericsson (Publ) Using dnai to identify a smf supporting connection to a local dn
US20210273861A1 (en) * 2019-02-28 2021-09-02 Tencent Technology (Shenzhen) Company Limited Network slice processing method, system and device, and storage medium

Families Citing this family (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112533236B (zh) * 2019-09-19 2023-06-02 华为技术有限公司 通信方法及装置
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CN112752352B (zh) * 2019-10-30 2023-06-23 大唐移动通信设备有限公司 一种中间会话管理功能i-smf确定方法和设备
CN112929868A (zh) * 2019-12-05 2021-06-08 中兴通讯股份有限公司 跨区漫游通信方法、装置、电子设备及计算机可读介质
CN113133008A (zh) * 2019-12-31 2021-07-16 华为技术有限公司 通信方法及装置
CN113660702B (zh) * 2020-05-12 2023-05-09 中国移动通信有限公司研究院 信息传输方法、节点选择方法、装置及设备
CN114071791B (zh) * 2020-08-06 2024-01-26 北京佰才邦技术股份有限公司 用户面功能信息上报方法、接入网设备及核心网设备
CN114071799A (zh) * 2020-08-10 2022-02-18 华为技术有限公司 管理会话连接的方法和装置
CN114727361A (zh) * 2021-01-04 2022-07-08 中国移动通信有限公司研究院 一种用于网络功能选择的处理方法、装置和网络设备
TWI806289B (zh) * 2021-01-29 2023-06-21 瑞典商Lm艾瑞克生(Publ)電話公司 工作階段管理功能、藉由工作階段管理功能執行之方法、電腦可讀儲存媒體及電腦程式產品
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CN116390184A (zh) * 2023-05-31 2023-07-04 阿里巴巴（中国）有限公司 用户面功能网元在线更换方法、网元设备和存储介质

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20170171752A1 (en) * 2015-12-14 2017-06-15 Qualcomm Incorporated Securing signaling interface between radio access network and a service management entity to support service slicing
CN107040975A (zh) * 2015-07-16 2017-08-11 中兴通讯股份有限公司 一种网络接入方法和装置
CN107318158A (zh) * 2016-04-26 2017-11-03 中兴通讯股份有限公司 一种消息发送、识别及移动性、会话管理的方法及节点

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106686676B (zh) * 2015-11-06 2020-10-09 华为技术有限公司 一种会话切换的方法、设备及系统
US10362511B2 (en) * 2016-05-17 2019-07-23 Lg Electronics Inc. Method and apparatus for determining PDU session identity in wireless communication system
CN107404736B (zh) * 2016-05-18 2019-12-10 电信科学技术研究院 一种切换方法、设备及网络架构
WO2018006017A1 (en) * 2016-07-01 2018-01-04 Idac Holdings, Inc. Methods for supporting session continuity on per-session basis
CN107018542A (zh) * 2017-03-27 2017-08-04 中兴通讯股份有限公司 网络系统中状态信息的处理方法、装置及存储介质

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107040975A (zh) * 2015-07-16 2017-08-11 中兴通讯股份有限公司 一种网络接入方法和装置
US20170171752A1 (en) * 2015-12-14 2017-06-15 Qualcomm Incorporated Securing signaling interface between radio access network and a service management entity to support service slicing
CN107318158A (zh) * 2016-04-26 2017-11-03 中兴通讯股份有限公司 一种消息发送、识别及移动性、会话管理的方法及节点

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
HUAWEI: "SMF selection in roaming case", SA WG2 MEETING #122 S 2-174543, vol. SA WG2, 25 June 2017 (2017-06-25) - 30 June 2017 (2017-06-30), XP051303388 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20210273861A1 (en) * 2019-02-28 2021-09-02 Tencent Technology (Shenzhen) Company Limited Network slice processing method, system and device, and storage medium
US11979297B2 (en) * 2019-02-28 2024-05-07 Tencent Technology (Shenzhen) Company Limited Network slice processing method, system and device, and storage medium
WO2021137180A1 (en) * 2019-12-30 2021-07-08 Telefonaktiebolaget Lm Ericsson (Publ) Using dnai to identify a smf supporting connection to a local dn

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