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WO2018201973A1 - 一种消息传输的方法及装置 - Google Patents

一种消息传输的方法及装置 Download PDF

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Publication number
WO2018201973A1
WO2018201973A1 PCT/CN2018/084729 CN2018084729W WO2018201973A1 WO 2018201973 A1 WO2018201973 A1 WO 2018201973A1 CN 2018084729 W CN2018084729 W CN 2018084729W WO 2018201973 A1 WO2018201973 A1 WO 2018201973A1
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WO
WIPO (PCT)
Prior art keywords
interface
group
management function
session
session management
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/CN2018/084729
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English (en)
French (fr)
Inventor
朱奋勤
吴问付
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Huawei Technologies Co Ltd
Original Assignee
Huawei Technologies Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from CN201810289567.3A external-priority patent/CN108810988B/zh
Application filed by Huawei Technologies Co Ltd filed Critical Huawei Technologies Co Ltd
Publication of WO2018201973A1 publication Critical patent/WO2018201973A1/zh
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/30—Connection release
    • H04W76/34—Selective release of ongoing connections
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/30—Connection release
    • H04W76/34—Selective release of ongoing connections
    • H04W76/36—Selective release of ongoing connections for reassigning the resources associated with the released connections

Definitions

  • the present application relates to the field of communications technologies, and in particular, to a method and an apparatus for message transmission.
  • the Serving GateWay can save the session context of the User Equipment (UE), and the session context of the UE includes the UE.
  • the IP address of the Mobility Management Entity (MME) when the SGW needs to send a downlink message related to the UE to the MME, the IP of the MME serving the UE may be obtained from the saved session context of the UE. The address, and further, sends a downlink message related to the UE to the MME according to the obtained IP address.
  • MME Mobility Management Entity
  • the UE session context is saved in the SMF, and the UE session context is included in the The external interface information of the processing unit (or the AMF instance served by the UE) in the access and Mobility Management Function (AMF) of the UE service, when the SMF needs to send the downlink message related to the UE,
  • the external interface information of the processing unit (or the AMF instance served by the UE) in the AMF that is served by the UE is obtained according to the session context of the UE, and the downlink message related to the UE is sent according to the obtained external interface information.
  • the SMF each time the SMF needs to send a downlink message related to the UE, the SMF sends a downlink message to the processing unit (or the AMF instance served by the UE) in the AMF that was last served for the UE, which will cause the UE to Always being served by the same processing unit or AMF instance, load imbalance will occur.
  • the embodiment of the present invention provides a method and a device for transmitting a message, which can solve the problem that the session management function device sends a UE-related downlink message to the first device that is served by the UE for the last time, and the load is unbalanced.
  • the application provides a method for message transmission, the method comprising:
  • the session management function device receives the deletion indication from the first device and the indication information of the group to which the first device belongs.
  • the session management function device is configured according to the session management function device.
  • the deletion indicates that the second interface information in the UE session context is deleted. Then, when the session management function device needs to send the downlink message, the session management function device sends the downlink message to the second device, where the second device is the indication information according to the group.
  • the deletion indication is used to indicate that the session management function device deletes the second interface information in the session context of the user equipment UE when the first interface release message is received, where the first interface is the radio access network RAN and the An interface between the first device, where the second interface is an interface between the first device and the session management function device.
  • the session management function device may be an AMF device, and the first device and the second device may each be an instance of the AMF group, or both the first device and the second device may be one of the AMF devices.
  • the session management function device deletes the second interface information in the UE session context, and then when the session management function device needs to send the downlink message, Searching for the interface information of the first device serving the UE last time from the UE context, and then triggering the process of reselecting the second device serving the UE, the session management function device may send the downlink message to the second device.
  • the phenomenon of load imbalance that always occurs when the same device is used to serve the UE is avoided.
  • the session management function device receives the deletion indication from the first device and the indication information of the group to which the first device belongs, and may be implemented as: the session management function device receives the session establishment request from the first device.
  • the session establishment request includes the group indication information, the deletion indication, and the second interface information.
  • the session management function device may save the indication information of the group, the deletion indication, and the second interface information in the UE session context.
  • the second interface information is saved in the UE session context, and before the UE is not switched to the idle state, the session management function device can directly communicate with the first device serving the UE according to the second interface information, without frequently reselecting The device served by the UE can improve the service quality when the UE is in the connected state.
  • the session management function device can delete the second interface information in the UE session context in time when receiving the release message of the first interface, so as to avoid the UE entering the connection state every time.
  • the session management function device deletes the second interface information in the UE session context according to the deletion indication, which may be implemented by: the session management function device deleting the UE session context according to the deletion indication in the UE session context. Second interface information.
  • the session management function device receives the deletion indication from the first device and the indication information of the group to which the first device belongs, and may be implemented as: the session management function device receives the session establishment request from the first device.
  • the session establishment request includes the indication information of the group and the second interface information, and then the session management function device receives the first interface release message from the first device, where the first interface release message includes a deletion indication.
  • the session management function device may save the indication information of the group and the second interface information in the UE session context.
  • the second interface information is saved in the UE session context, and before the UE is not switched to the idle state, the session management function device can directly communicate with the first device serving the UE according to the second interface information, without frequently reselecting
  • the device served by the UE can improve the service quality when the UE is in the connected state.
  • the session management function device receives the deletion indication from the first device and the indication information of the group to which the first device belongs, and may be implemented as: the session management function device receives the first interface from the first device. Release the message, the first interface releases the indication information including the group and the deletion indication in the message.
  • the session management function device Before the session management function device receives the first interface release message from the first device, the session management function device receives a session establishment request from the first device, where the second interface information is included in the session establishment request, and then the session management function device The second interface information is saved in a UE session context.
  • the first interface release message carries the deletion indication, so that the session management function device deletes the second interface information in the UE session context in time when the first interface release message is received, so as to prevent the UE from entering the connection state every time.
  • the same device service solves the problem of load imbalance in the prior art.
  • the session management function device deletes the second interface information in the UE session context according to the deletion indication, which may be implemented as follows: the session management function device deletes the session of the UE according to the deletion indication included in the first interface release message. Second interface information in context.
  • the indication information of the group is the group identity ID of the group; the session management function device may determine the second device serving the UE according to the group ID, and then the session management function device passes the session management function. The interface between the device and the second device sends a downlink message to the second device.
  • the indication information of the group is a default route of the group; when the session management function device needs to send a downlink message, the session management function device sends a downlink message to the device corresponding to the default route of the group. Then, the second device identifier of the device corresponding to the default route of the group is received, and the device corresponding to the default route of the group is the second device selected by the UE, and the session management function device uses the session management function device to The interface between the second device sends a downlink message to the second device corresponding to the second device identifier.
  • the indication information of the group is the default route of the group; when the session management function device needs to send the downlink message, the session management function device sends the device corresponding to the default route of the group to the second device.
  • the device that sends the downlink message, where the second device is the default route of the group, is the second device selected by the UE.
  • the session management function device after the session management function device sends a downlink message to the second device by using the device corresponding to the default route of the group, after the session management function device receives the message from the second device, the session The management function device saves the interface information between the session management function device and the second device in the UE session context.
  • the session management function device does not need to reselect each time the downlink message of the UE is sent before the UE switches to the idle state.
  • the device serving the UE can save overhead and avoid the situation in which the UE service is interrupted due to reselection of the device served by the UE.
  • the application provides a method for message transmission, the method comprising:
  • the session management function device acquires the stateless indication information and the group indication information of the group to which the first device belongs, and the stateless indication information is used to indicate that the session management function device determines the binding of the signaling connection corresponding to the user equipment UE to the first interface.
  • the second device for serving the UE is selected according to the group indication information, and then, when the session management function device receives the release notification from the first device, when the session management function device needs When the downlink message is sent, the session management function device sends a downlink message to the second device.
  • the first device is a device that serves the UE before the binding of the signaling connection and the first interface is released, the first interface is an interface between the radio access network RAN and the first device, and the second device is according to the group indication information.
  • the release notification is used to indicate that the binding of the signaling connection to the first interface has been released.
  • the session management function device may be an AMF device, and both the first device and the second device may be one instance of the AMF group, or both the first device and the second device may be one of the AMF devices.
  • the group indication information of the group to which the first device belongs may be an AMF group ID, or may be a default route of the AMF group.
  • the binding release of the signaling connection and the first interface includes but is not limited to the following two situations:
  • the first type the signaling connection corresponding to the UE is released, and the binding of the signaling connection to the first interface is also released.
  • the second type the binding of the signaling connection to the first interface is released, and the signaling connection corresponding to the UE is not released.
  • the session management function device may determine to re-select the service for the UE in the case that it is determined that the binding of the signaling connection corresponding to the UE and the first interface has been released, and the downlink message needs to be sent.
  • the two devices send downlink messages, thus avoiding the load imbalance that always occurs when the same device provides services for the UE.
  • the session management function device may determine the binding release of the signaling connection corresponding to the UE and the first interface before the session management function device sends the downlink message to the second device.
  • the session management function module needs to send a downlink message, and determines that the binding connection of the signaling connection corresponding to the UE and the first interface is released, determining, according to the group indication information, the second service for serving the UE device.
  • the second device that is determined to serve the UE can avoid the service provided by the first device to the terminal at all times.
  • the session management function device needs to send a downlink message
  • the second device may send a downlink message to the terminal.
  • the session management function device obtains the group indication information of the group to which the first device belongs, which may be implemented as follows:
  • the session management function device receives the session establishment request from the first device, where the session establishment request includes the group indication information; or the session management function device receives the release notification from the first device, where the release notification includes the group indication information.
  • the session management function device obtains stateless indication information, including:
  • the session management function device receives a session establishment request from the first device, where the session establishment request includes stateless indication information; or the session management function device receives the release notification notification from the first device, including stateless indication information; or, the session The management function device obtains stateless indication information from the local configuration information.
  • the release notification includes a deletion indication.
  • the deletion indication is used to instruct the session management function device to delete the information of the first device.
  • the session management function device deletes the information about the first device in the UE session context when the binding of the signaling connection corresponding to the UE and the binding of the first interface is released, and then the session management function device needs to send
  • the information of the first device serving the UE last time cannot be searched from the UE context, and then the process of reselecting the second device serving the UE may be triggered, and the session management function device may send the downlink message.
  • the load imbalance that always occurs when the same device provides services for the UE is avoided.
  • the session management function device after the session management function device receives the release notification from the first device, the session management function device deletes the information of the first device in the UE session context according to the stateless indication information.
  • the session management function device after the session management function device receives the release notification from the first device, the session management function device saves the release state of the binding of the signaling connection with the first interface, and then when the session management function device When the downlink message needs to be sent, the session management function determines that the binding of the signaling connection to the first interface is released according to the release state of the binding of the signaling connection with the first interface, and then the session management function determines, according to the group indication information, that The second device served by the UE.
  • the session management function device can save the release state of the binding of the signaling connection and the first interface, and further, if the session management function device needs to send the downlink message, Determining the second device for serving the UE, and avoiding that the first device is used to provide services for the UE, and the load is unbalanced. If the session management function does not need to send the downlink message, the second device for serving the UE does not need to be determined. Can save system overhead.
  • the group indication information is a group identity ID of the group to which the first device belongs; correspondingly, the session management function device sends a downlink message to the second device, which may be implemented as: The function device needs to send a downlink message, and determines that the binding of the signaling connection corresponding to the UE to the first interface is released, and then determines the second device that serves the UE according to the group ID.
  • the present application provides an apparatus for message transmission, which may implement the functions performed by the session management function device in the above first aspect or the second aspect, and the functions may be implemented by hardware or by hardware.
  • the hardware or software includes one or more modules corresponding to the above functions.
  • the apparatus includes a processor and a communication interface configured to support the apparatus to perform the corresponding functions of the above methods.
  • the communication interface is used to support communication between the device and other network elements.
  • the apparatus can also include a memory for coupling with the processor that retains the program instructions and data necessary for the apparatus.
  • the application provides a system for message transmission, comprising the session management function device of the first aspect or the second aspect, the UE, the RAN, and a group to which the first device belongs.
  • the present application provides a computer storage medium for storing computer software instructions for use in the above-described session management function device, including a program designed to perform the above aspects.
  • the application provides a computer program product, such as a computer readable storage medium, comprising a program designed to perform the above aspects.
  • the session management function device deletes the second interface information in the UE session context, and then when the session management function device needs to send the downlink message, Searching for the interface information of the first device serving the UE last time from the UE context, and then triggering the process of reselecting the second device serving the UE, the session management function device may send the downlink message to the second device.
  • the phenomenon of load imbalance that always occurs when the same device is used to serve the UE is avoided.
  • FIG. 1 is a schematic structural diagram of a communication system provided by the present application.
  • FIG. 2 is a schematic structural diagram of another communication system provided by the present application.
  • FIG. 3 is a schematic structural diagram of an AMF device provided by the present application.
  • FIG. 4 is a schematic structural diagram of another AMF device provided by the present application.
  • FIG. 5 is a schematic structural diagram of an SMF device provided by the present application.
  • FIG. 6 is a flowchart of a method for message transmission provided by the present application.
  • FIG. 7 is a flowchart of another method for message transmission provided by the present application.
  • FIG. 8 is a flowchart of another method for message transmission provided by the present application.
  • FIG. 9 is a schematic structural diagram of an apparatus for message transmission according to the present application.
  • FIG. 10 is a flowchart of another method for message transmission provided by the present application.
  • FIG. 11 is a schematic structural diagram of another apparatus for message transmission provided by the present application.
  • the embodiment of the present application is applied to a communication system as shown in FIG. 1, which includes a session management function device 101, an access and mobility management function device 102, and an access network device 103.
  • the access and mobility management function device 102 includes multiple devices, for example, the first device and the second device, and the access and mobility management function device 102 may further include an ASF unit, and the ASF unit is a network.
  • the function may be a default AMF instance as shown in FIG. 3, or may be a dedicated network function, for example, may be a load balancer.
  • the session management function device 101 is configured to receive the deletion indication from the first device and the indication information of the group to which the first device belongs, where the first device is the device currently serving the UE in the access and mobility management function device 102.
  • the group to which the first device belongs is the access and mobility management function device 102.
  • the first device in the access and mobility management function device 102 is configured to send a first interface release message to the session management function device 101, where the first interface is an interface between the access network device 103 and the first device.
  • the session management function device 101 is further configured to delete, according to the deletion indication, the second interface information in the UE session context, where the first interface is the first device and the session management, in the case that the first interface release message from the first device is received. Interface between functional devices 101. Then, when the session management function device 101 needs to send a downlink message, the downlink device may be sent to the second device, where the second device is a device for serving the UE according to the indication information of the group.
  • the UE involved in the present application may include various handheld devices with wireless communication functions, in-vehicle devices, wearable devices, computing devices, or other processing devices connected to the wireless modem, and various forms of terminals.
  • MS Mobile station
  • UE user equipment
  • Terminal Equipment Terminal Equipment
  • soft terminal and the like.
  • the devices mentioned above are collectively referred to as UEs.
  • the present application is applicable to a 5G network.
  • the architecture diagram of the communication system is as shown in FIG. 2, which includes an Authentication Server Function (AUSF) device and unified data management (Unified).
  • Data Management (UDM) device AMF device, SMF device, Policy Control Function (PCF) device, UE, Radio Access Network (RAN) or Access Network (AN), user User Plane Function (UPF) device, Data Network (DN) device.
  • AUSF Authentication Server Function
  • UDM Data Management
  • AMF Access Management
  • SMF Policy Control Function
  • PCF Policy Control Function
  • UE Radio Access Network
  • AN Access Network
  • UPF User Plane Function
  • DN Data Network
  • the session management function device 101 in FIG. 1 can be implemented as the SMF device in FIG. 2, and the access and mobility management function device 102 in FIG. 1 can be implemented as the AMF device in FIG. 2, and the access network in FIG. Device 103 may be implemented as a RAN or AN in FIG.
  • the AMF device can serve the UE, authorize the access of the UE, and manage the mobility of the UE. At the same time, the AMF device is also used to transmit non-access stratum (NAS) messages between the UE and the SMF.
  • the RAN can communicate with the UE and the AMF device. For example, after receiving the NAS message sent by the UE, the RAN can forward the NAS message to the AMF device.
  • the SMF device can communicate with the AMF device, for example, can send downlink messages to the AMF device, and the like.
  • the SMF device is also used to manage the session.
  • the SMF device can maintain interface information between the AMF device and the SMF device in the context of the UE session, so that the SMF device can directly obtain the downlink message for a certain UE.
  • the interface information stored in the session context of the UE is determined to be the AMF device served by the UE.
  • the serial number marked on the connecting line between the devices in FIG. 2 is used to distinguish the interfaces between different devices.
  • FIG. 2 is only an exemplary schematic diagram, and the serial number of the interface between the devices is not limited in this application.
  • the UE communicates with the AMF through the N1 interface
  • the RAN communicates with the AMF through the N2 interface
  • each UPF communicates through the N9 interface
  • the UPF communicates with the DN through the N6 interface.
  • the SMF controls the SMF through the N4 interface.
  • the AMF communicates with the SMF through the N11 interface.
  • the AMF and the SMF obtain the user subscription data from the UDM through the N8 interface and the N10 interface respectively, and obtain the policy data from the PCF through the N15 interface and the N7 interface respectively.
  • the AMF devices communicate through the N14 interface
  • the AUSF communicates with the AMF through the N12 interface and communicates with the UDM through the N13 interface.
  • FIG. 1 and FIG. 2 are only schematic structural diagrams of a communication system to which the present application is applied. In actual deployment, the number of devices in the communication system is not limited to the number of devices shown in FIGS. 1 and 2.
  • each device in FIG. 1 to FIG. 2 may be implemented by one physical device, or may be implemented by multiple physical devices, or may be a logical functional module in a physical device. limited.
  • the UE, the RAN, the AMF device, the SMF device, the AUSF device, and the UDM device in the above 5G network are only one name, and the name does not limit the device itself.
  • the network element or the entity corresponding to the UE, the RAN, the AMF device, the SMF device, the AUSF device, and the UDM device may also be other names, which is not specifically limited in this embodiment of the present application.
  • the UDM device may be replaced with a Home Subscriber Server (HSS) or a User Subscription Database (USD) or a database entity, and the like, and is not described here.
  • HSS Home Subscriber Server
  • USD User Subscription Database
  • FIG. 3 shows one of the AMF devices, and the AMF device includes a database (Database, DB). At least one Load Balancer (LB) unit and at least two processing units.
  • the LB unit is configured to select a processing unit for the UE, and distribute the received NAS message to a corresponding processing unit.
  • the processing unit is configured to process the received NAS and other messages, and the multiple processing units can share the data in the database.
  • each LB unit and the processing unit have an external interface.
  • the external interface of the LB unit in the AMF device is configured as an external interface of the AMF device in the RAN device, and when the RAN device receives the After the NAS message sent by the UE in the idle state, the RAN device first selects an AMF device, then selects one of the LB unit interfaces configured in the RAN device from the AMF device, and then sends the NAS message to the AMF device through the selected LB unit interface. After receiving the NAS message, the LB unit allocates a processing unit for the NAS message. When the UE is in the connected state, the RAN device can directly communicate with the processing unit, and there is no need to forward data through the LB unit.
  • the AMF device in FIG. 2 can also be implemented in a group manner.
  • the AMF group includes a database, at least one LB unit, and at least two AMF instances.
  • the LB unit is configured to select an AMF instance for the UE, and distribute the received NAS message to the corresponding AMF instance.
  • the AMF instance is used to process the received NAS and other messages, and the multiple AMF instances may share the data in the data.
  • each LB unit and the AMF instance have an external interface.
  • the external interface of the LB unit is configured as an external interface of the AMF group in the RAN device, and when the RAN device receives the idle state.
  • the RAN device selects an AMF group, and then selects an LB unit interface of the AMF group, and sends the NAS message to the LB unit in the AMF group through the LB unit interface, and the LB unit receives
  • an AMF instance is assigned to the NAS message.
  • the RAN device can directly communicate with the AMF instance without having to forward data through the LB unit.
  • the SMF device saves the external interface information of the processing unit or the AMF instance serving the UE when the session is established or the session is activated, in the UE session context.
  • the SMF device needs to send a downlink message
  • the SMF device always sends the downlink message to the processing unit served last time for the UE according to the last interface information of the processing unit or the AMF instance that is saved for the UE in the UE session context. AMF instance.
  • the principle of the present application is: when the AMF device in FIG. 2 is implemented as FIG. 3, the processing unit in the AMF device carries the deletion in the session establishment request or the N2 release message sent to the SMF device. Instructing and SMF identification, and in the case that the SMF device receives the N2 release message, the SMF device can delete the interface information between the processing unit and the SMF device in the UE session context according to the deletion indication, so that the SMF device needs to send the downlink message.
  • the SMF device can only send the downlink message to the processing unit reselected according to the AMF identifier, thereby avoiding sending to the same processing unit each time.
  • the AMF instance in the AMF group carries the deletion indication and the AMF group identifier in the session establishment request or the N2 release message sent to the SMF device, and then received on the SMF device.
  • the SMF device can delete the interface information between the AMF instance and the SMF device in the UE session context according to the deletion indication, so that when the SMF device needs to send the downlink message, there is no AMF instance in the UE session context. Interface information with the SMF device, so the SMF device can only send downlink messages to the reselected AMF instance according to the AMF group identity, thus avoiding the load imbalance that occurs when sending downlink messages to the same AMF instance each time. problem.
  • the SMF device may include: a memory 501, a processor 502, a communication interface 503, and a bus 504. Connections between devices and mutual communication.
  • the communication interface 503 can be implemented by an antenna, and can be used for data interaction with an external network element.
  • the communication interface 503 of the SMF device can send and receive data packets or other information between the AMF device.
  • the processor 502 which may be a central processing unit (CPU), may be an application specific integrated circuit (ASIC), or one or more configured to implement the embodiments of the present invention. Integrated circuits. For example: one or more microprocessors (English: Digital Singnal Processor, DSP), or one or more Field Programmable Gate Arrays (FPGAs).
  • the processor 502 has a processing management function. Specifically, the processor 502 in the SMF device can process data or information sent by the received AMF device, the UPF device, or the PCRF device, or process information or data sent by other devices. .
  • the memory 501 may be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other information storage instructions and instructions.
  • ROM read-only memory
  • RAM random access memory
  • Type of dynamic storage device or Electrostatic Erasable Programmable Read-Only Memory (EEPROM), Compact Disc Read-Only Memory (CD-ROM) or other optical disc storage, optical disc Storage (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or can be used to carry or store desired program code in the form of instructions or data structures and can be Any other medium accessed by the computer, but is not limited to this.
  • Memory 501 can exist independently and is coupled to processor 502 via bus 504. Memory 501 can also be integrated with processor 502.
  • the first interface is an interface between the AMF device and the RAN device shown in FIG. 2 (corresponding to N2 in FIG. 2).
  • the second interface is an interface between the AMF device and the SMF device shown in FIG. 2, specifically an interface between the first device and the SMF device that is serving the UE in the AMF device.
  • the first device is a processing unit in the AMF device
  • the group to which the first device belongs is the AMF device where the processing unit is located
  • the second interface is one of the AMF devices.
  • the interface between the unit and the SMF device (corresponding to N11 in Figure 2).
  • the first device is an AMF instance in the AMF group
  • the group to which the first device belongs is the AMF group in which the AMF instance is located
  • the second The interface is an interface between an AMF instance and an SMF device in the AMF group (corresponding to N11 in FIG. 2).
  • the second device is a device that is re-determined for serving the UE after the SMF device deletes the second interface information between the first device and the SMF device saved in the UE session context.
  • the second device is one of the AMF devices.
  • the second device is an AMF instance in the AMF group.
  • an embodiment of the present application provides a method for message transmission.
  • the UE and the RAN are used.
  • the interaction process between the device, the AMF instance 1, the AMF instance 2, and the SMF device is described as an example.
  • the AMF instance 1 and the AMF instance 2 belong to the same AMF group.
  • the method includes three phases, and the first phase is The session establishment process corresponds to steps 601 to 603; the second phase is a process in which the UE enters an idle state, corresponding to steps 604 to 607; and the third phase is a process in which the UE re-enters the connection state when the SMF device needs to send a downlink message. Corresponding to steps 608 to 611.
  • the method specifically includes:
  • the UE sends a session establishment request to the AMF instance 1, and the AMF instance 1 receives the session establishment request.
  • the UE sends a session establishment request to the AMF instance 1 to trigger a user datagram protocol (PDU) session establishment process.
  • PDU user datagram protocol
  • the AMF instance 1 sends a session establishment request to the SMF device, and the SMF device receives the session establishment request.
  • the session establishment request may have the following three implementation manners.
  • the first type the second interface information (N11 interface information) of the AMF instance 1 is included in the session establishment request.
  • the second type the session establishment request includes the second interface information (N11 interface information) of the AMF instance 1, and the indication information of the AMF group to which the AMF instance 1 belongs.
  • the third type the session establishment request includes the second interface information (N11 interface information) of the AMF instance 1, the deletion indication, and the indication information of the AMF group to which the AMF instance 1 belongs.
  • the indication information of the AMF group may be an AMF group ID or a default route of the AMF group.
  • the indication information of the AMF group is taken as an example of the AMF group ID.
  • the AMF instance 1 needs to first determine whether the AMF group to which it belongs supports statelessness. If the AMF group supports stateless, the AMF instance 1 will carry the deletion indication. In the session establishment request. With reference to FIG. 4, the AMF group supports the stateless state, the AMF instance does not save the UE session context information, and the session context information of the UE served by each AMF instance in the AMF group is saved in the DB of the AMF group.
  • the AMF instances in the same AMF group can share the UE session context information stored in the DB, so that each AMF instance can process not only related information of the UEs served by itself but also related information of other UEs.
  • the deletion indication is used to instruct the SMF device to delete the second interface information in the UE session context stored by the SMF device when receiving the first interface release message.
  • the SMF device saves information carried in the session establishment request in a UE session context.
  • the session establishment request carries the second interface information of the AMF instance 1, because the AMF instance currently serving the UE is the AMF instance 1, so
  • the SMF device needs to save the second interface information of the AMF instance 1 in the UE session context, so that when the UE is in the connected state, the SMF device can directly access the AMF serving the UE by using the second interface information saved in the UE session context.
  • Example 1 sends a downlink message.
  • the SMF device further needs to save the indication information of the AMF group in the UE session context, and similarly, if the session establishment request further includes the deletion indication, the SMF device The deletion indication also needs to be saved in the UE session context.
  • the UE session context can be saved in the SMF device or in other devices with storage functions.
  • the foregoing steps 601 to 603 are the session establishment process. After the session is established, when the UE enters the idle state, the process of the UE entering the idle state needs to be performed.
  • the RAN device sends a first interface release request message to the AMF instance 1, and the AMF instance 1 receives the first interface release request message.
  • the AMF instance 1 device releases the first interface according to the first interface release request message.
  • the UE switches from the connected state to the idle state.
  • the AMF instance 1 sends a first interface release message to the SMF device, and the SMF device receives the first interface release message.
  • the first interface release message also includes three implementation manners.
  • the first interface release message may carry the deletion indication, the indication information of the AMF group to which the AMF instance 1 belongs, and the first interface release notification.
  • the first interface release message may carry the deletion indication and the first interface release notification.
  • the third type if the session establishment request is the third implementation manner described in step 602, the first interface release message may carry the first interface release notification.
  • AMF instance 1 is to carry the deletion indication in the first interface release message, it is necessary to first determine whether the AMF group to which it belongs supports stateless. If the AMF group supports stateless, AMF instance 1 will delete. The indication is carried in the first interface release message.
  • the SMF device deletes the second interface information in the UE session context according to the deletion indication, when the first interface release message is received.
  • the SMF device directly deletes the second interface information in the UE session context according to the deletion indication carried in the first interface release message. If the deletion indication is not carried in the first interface release message, and the deletion indication is saved in the UE session context, the SMF device deletes the second interface information according to the deletion indication saved in the UE session context.
  • the SMF device receives the first interface release message, indicating that the UE has entered the idle state, and the SMF device deletes the second interface information in the UE session context, so that the SMF device still avoids the UE session context when the UE re-enters the link state.
  • the second interface information in the AMF instance 1 is taken as an AMF instance serving the UE. At this time, since the second interface information does not exist in the UE session context, the AMF instance serving as the UE can only be re-selected in the AMF group, and the UE is always served by the same AMF instance.
  • steps 604 to 607 are the process of the UE entering the idle state. If the subsequent SMF device receives the downlink message for the UE, the following steps 608 to 611 are also performed to enable the UE to re-enter the connection state.
  • the SMF device When the SMF device needs to send a downlink message, the SMF device selects an AMF instance serving as the UE from the AMF group according to the AMF group ID, for example, AMF instance 2.
  • the SMF device may look up an AMF instance serving the UE from a Network Function Repository Function (NRF) device or other device according to the AMF group ID.
  • NRF Network Function Repository Function
  • the specific method for the SMF device to select an AMF instance for serving the UE according to the AMF group ID is the same as that of the prior art, and details are not described herein again.
  • the SMF device may save the interface information between the SMF device and the AMF instance 2 in the UE session context after reselecting the AMF instance 2 serving the UE, so that the UE is always connected. In the case of a state, the SMF device communicates directly with AMF instance 2 without having to reselect the AMF instance.
  • the SMF device may also save the interface information between the SMF device and the AMF instance 2 through the subsequent steps 610 to 611.
  • the SMF device sends a downlink message to the AMF instance 2 through the interface between the SMF device and the AMF instance 2.
  • the AMF instance 2 receives the downlink message.
  • the AMF instance 2 may also re-select an AMF instance for the UE, for example, AMF instance 3, and send the message to the AMF instance 3.
  • the downlink message, or the identifier of the AMF instance 3 is sent to the SMF device, and the SMF device sends a downlink message to the AMF instance 3.
  • steps 610 to 611 may also be performed.
  • the AMF instance 2 sends a response message to the SMF device, where the response message includes interface information between the AMF instance 2 and the SMF device, and the SMF device receives the response message.
  • the SMF device saves interface information between the AMF instance 2 and the SMF device in a UE session context.
  • the method for transmitting a message provided by the embodiment of the present application is that the SMF device in the prior art always selects an AMF instance that is served by the UE to provide a service for the UE.
  • the RAN is released in the RAN.
  • the SMF device deletes the interface information between the SMF device in the UE context and the AMF instance served by the UE, and then the SMF device needs to send the UE for the UE.
  • the interface information between the AMF instance serving the UE and the SMF device last time cannot be directly searched from the UE context, and the AMF instance served last time for the UE is not selected, but is re-selected.
  • the AMF instance avoids the load imbalance caused by the SMF device always selecting the AMF instance that was last served for the UE.
  • the indication information of the AMF group is taken as an example of the AMF group ID. In another implementation manner provided by the embodiment of the present application, the indication information of the AMF group is used. It can also be a default route of the AMF group. When the indication information of the AMF group is the default route of the AMF group, as shown in FIG. 7, the method can be implemented as the following steps 701 to 712.
  • the steps 701 to 707 are the same as the above steps 601 to 607, and the steps 711 to 712 are the same as the above steps 610 to 611, and details are not described herein again.
  • the SMF device When the SMF device needs to send the downlink message, the SMF device sends a downlink message to the device corresponding to the default route of the AMF group, and the device corresponding to the default route of the AMF group receives the downlink message.
  • the default route of the AMF group is directed to the ASF unit, where the ASF unit is a network function, which may be a default AMF instance in the AMF group, or may be a dedicated network function, for example, may be a load. Equalizer.
  • the ASF unit selects an AMF instance serving the UE, for example, AMF instance 2.
  • the ASF unit sends a downlink message to the AMF instance 2, and the AMF instance 2 receives the downlink message.
  • step 710 may be replaced by the ASF unit sending an identifier of the AMF instance 2 to the SMF device, and then the SMF device sends a downlink message to the AMF instance 2 according to the identifier of the AMF instance 2.
  • the embodiment corresponding to FIG. 6 and FIG. 7 is an implementation manner when the method for message transmission of the present application is applied to the scenario shown in FIG. 4.
  • the method for message transmission of the present application may also be In the scenario shown in FIG. 3, the interaction process between the UE, the RAN device, the processing unit 1, the processing unit 2, and the SMF device is taken as an example.
  • the processing unit 1 and the processing unit 2 belong to the same AMF.
  • the device as shown in Figure 8, includes:
  • the UE sends a session establishment request to the processing unit 1, and the processing unit 1 receives the session establishment request.
  • the UE sends the session establishment request to the processing unit 1 to trigger the process of establishing the PDU session.
  • the UE initiates the process of establishing the PDU session, the UE is in a connected state, and the UE is serving the processing unit 1 at this time.
  • the processing unit 1 sends a session establishment request to the SMF device, and the SMF device receives the session establishment request.
  • the session establishment request may have the following three implementation manners.
  • the first type the session establishment request includes the second interface information (N11 interface information) of the processing unit 1.
  • the second type the session establishment request includes the second interface information (N11 interface information) of the processing unit 1 and the indication information of the AMF device to which the processing unit 1 belongs.
  • the third type the session establishment request includes the second interface information (N11 interface information) of the processing unit 1, the deletion indication, and the indication information of the AMF device to which the processing unit 1 belongs.
  • the indication information of the AMF device may be an AMF device ID or a default route of the AMF device.
  • the indication information of the AMF device is taken as an AMF device ID as an example for description.
  • the SMF device saves information carried in the session establishment request in a UE session context.
  • the second interface information of the processing unit 1 is carried in the session establishment request, because the processing unit currently serving the UE is the processing unit 1, so
  • the SMF device needs to save the second interface information of the processing unit 1 in the UE session context, so that when the UE is in the connected state, the SMF device can directly process the service for the UE by using the second interface information saved in the UE session context.
  • Unit 1 sends a downlink message.
  • the SMF device further needs to save the indication information of the AMF device in the UE session context.
  • the SMF device needs to The deletion indication is saved in the UE session context.
  • the foregoing steps 801 to 803 are the session establishment process. After the session is established, when the UE enters the idle state, the process of the UE entering the idle state needs to be performed.
  • the RAN device sends a first interface release message to the processing unit 1, and the processing unit 1 receives the first interface release message.
  • the processing unit 1 releases the first interface according to the first interface release message.
  • the processing unit 1 releases the first interface between the processing unit 1 and the RAN, the UE is switched from the connected state to the idle state.
  • the processing unit 1 sends a first interface release message to the SMF device, and the SMF device receives the first interface release message.
  • the first interface release message also includes three implementation manners.
  • the first interface release message may carry the deletion indication, the indication information of the AMF group to which the processing unit 1 belongs, and the first interface release notification.
  • the first interface release message may carry the deletion indication and the first interface release notification.
  • the first interface release message may carry the first interface release notification.
  • each processing unit of the AMF device supports stateless means that the UE session context information is not saved in each processing unit, and the UE served by each processing unit The session context information is saved in the DB, and the processing unit in the same AMF device can share the UE session context information stored in the DB.
  • the SMF device deletes the second interface information in the UE session context according to the deletion indication, when the first interface release message is received.
  • the SMF device directly deletes the second interface information in the UE session context according to the deletion indication carried in the first interface release message. If the deletion indication is not carried in the first interface release message, and the deletion indication is saved in the UE session context, the SMF device deletes the second interface information according to the deletion indication saved in the UE session context.
  • the SMF device receives the first interface release message, indicating that the UE has entered the idle state, and the SMF device deletes the second interface information in the UE session context, so that the SMF device still avoids the UE session context when the UE re-enters the link state.
  • the second interface information in the processing unit 1 is treated as a processing unit serving the UE. At this time, since the second interface information does not exist in the UE session context, the processing unit serving as the UE can only be reselected in the SMF device, and the UE is always served by the same processing unit.
  • steps 804 to 807 are the process of the UE entering the idle state. If the subsequent SMF device receives the downlink message for the UE, the following steps 808 to 811 are also performed to enable the UE to re-enter the connection state.
  • the SMF device When the SMF device needs to send a downlink message, the SMF device selects an ASF unit of the AMF device according to the AMF device ID.
  • the SMF device can search for an external interface of the AMF device from the NRF device or other device according to the AMF device ID, and the interface can be the transport layer information of the ASF unit.
  • the ASF unit may be one LB unit in the AMF device, or may be one processing unit in the AMF device.
  • the SMF device may directly send a downlink message to the processing unit, and the processing unit provides a service for the UE, or the processing unit receives the downlink message sent by the SMF device.
  • the following steps 810 to 811 may also be performed to reselect the processing unit serving the UE and send the downlink message to the reselected processing unit.
  • the SMF device sends a downlink message to the ASF unit, and the ASF unit receives the downlink message.
  • steps 810 to 811 may also be performed.
  • the ASF unit selects a processing unit serving the UE, for example, the processing unit 2.
  • the ASF unit sends a downlink message to the processing unit 2, and the processing unit 2 receives the downlink message.
  • the ASF unit may further send an identifier of the processing unit 2 to the SMF device, and the SMF device sends a downlink message to the processing unit 2 according to the identifier of the processing unit 2.
  • steps 812 to 813 may also be performed.
  • the processing unit 2 sends a response message to the SMF device, where the response message includes interface information between the processing unit 2 and the SMF device, and the SMF device receives the response message.
  • the SMF device saves interface information between the processing unit 2 and the SMF device in a UE session context.
  • the method for message transmission provided by the embodiment of the present application, after the RAN releases the interface between the RAN and the processing unit serving the UE, the SMF device will between the SMF device in the UE context and the processing unit serving the UE.
  • the interface is deleted, and when the SMF device needs to send a downlink message, the process of selecting the processing unit needs to be triggered again, and load balancing between the processing units can be implemented.
  • the solution provided by the embodiment of the present invention is mainly introduced from the perspective of the SMF device. It can be understood that the SMF device includes corresponding hardware structures and/or software modules for performing various functions.
  • the present application can be implemented in a combination of hardware or hardware and computer software in combination with the elements and algorithm steps of the various examples described in the embodiments disclosed herein. Whether a function is implemented in hardware or computer software to drive hardware depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods for implementing the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.
  • the embodiment of the present application may divide the function module into the SMF device according to the foregoing method example.
  • each function module may be divided according to each function, or two or more functions may be integrated into one processing module.
  • the above integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiments of the present application is schematic, and is only a logical function division, and may be further divided in actual implementation.
  • FIG. 9 shows a possible structural diagram of the SMF device involved in the above embodiment.
  • the SMF device includes: a receiving module 901, a deleting module 902, and a sending module 903.
  • the receiving module 901 is configured to receive the deletion indication from the first device and the indication information of the group to which the first device belongs, and the deletion indication is used to instruct the deletion module 902 to delete the user when the receiving module 901 receives the first interface release message. Second interface information in the device UE session context.
  • the deleting module 902 is configured to delete the second interface information in the UE session context according to the deletion indication if the receiving module 901 receives the first interface release message.
  • the sending module 903 is configured to send a downlink message to the second device when the downlink message needs to be sent.
  • the device further includes: a storage module 904.
  • the receiving module 901 is specifically configured to receive a session establishment request from the first device, where the session establishment request includes the group indication information, the deletion indication, and the second interface information.
  • the storage module 904 is configured to save the indication information of the group, the deletion indication, and the second interface information in a UE session context.
  • the deleting module 902 is specifically configured to: when the receiving module receives the first interface release message sent by the first device, delete the second interface information in the UE session context according to the deletion indication in the UE session context.
  • the receiving module 901 is specifically configured to receive a session establishment request from the first device, where the session establishment request includes the group indication information and the second interface information, and the receiving The first interface from the first device releases the message, and the first interface release message includes a deletion indication.
  • the storage module 904 is configured to save the indication information of the group and the second interface information in a UE session context.
  • the receiving module 901 is specifically configured to receive a session establishment request from the first device, where the session establishment request includes second interface information, and receive from the first device.
  • the first interface releases the message, and the first interface release message includes the group indication information and the deletion indication.
  • the storage module 904 is configured to save the second interface information in a UE session context.
  • the deleting module 902 is specifically configured to delete the second interface information in the session context of the UE according to the deletion indication included in the first interface release message.
  • the indication information of the group is a group identity ID of the group
  • the sending module 903 is specifically configured to determine, according to the group ID, a second device that is served by the UE, and send, by using an interface between the device for transmitting the message and the second device, a downlink message to the second device.
  • the indication information of the group is a default route of the group
  • the sending module 903 is specifically configured to send a downlink message to the device corresponding to the default route of the group, receive the second device identifier of the device corresponding to the default route of the group, and the second device is the default route corresponding to the group.
  • the device is a second device selected by the UE.
  • the second device corresponding to the second device identifier received by the receiving module sends a downlink message to the second device corresponding to the second device identifier.
  • the indication information of the group is a default route of the group
  • the sending module 903 is configured to send, by the device corresponding to the default route of the group, a downlink message to the second device, where the device corresponding to the default route of the second device is the second device selected by the UE.
  • the storage module 904 is configured to save the interface information between the device for transmitting the message and the second device in the UE session context after the receiving module 901 receives the message from the second device.
  • the receiving module 901 is configured to support the SMF device to receive the session establishment request sent in step 602 in FIG. 6, the first interface release message sent in step 606, the response message sent in step 610, and FIG.
  • the first interface release message sent in step 702, the first interface release message sent in step 706, and the response message sent in step 711 is further used to support the SMF device to receive the session establishment request sent in step 802 in FIG. 8, and the step 806 sends the message.
  • the first interface releases the message and the response message sent in step 812.
  • the deleting module 903 is configured to support the SMF device to perform step 607 in FIG. 6, step 707 in FIG. 7, and step 807 in FIG.
  • the sending module 903 is configured to support the SMF device to perform step 609 in FIG. 6, step 708 in FIG. 7, and step 809 in FIG.
  • the storage module 904 is configured to support the SMF device to perform step 603 and step 611 in FIG. 6, step 703 and step 712 in FIG. 7, step 803 and step 813 in FIG.
  • the receiving module 901 and the transmitting module 903 shown in FIG. 9 can be integrated in the communication interface 503 shown in FIG. 5, so that the communication interface 503 executes the receiving module 901 and transmits.
  • the delete module 902 can be integrated into the processor 502 shown in FIG. 5, causing the processor 502 to perform the specific functions of the delete module 902.
  • the storage module 904 can be integrated in the memory 501 shown in FIG. 5 to cause the memory 501 to perform the specific functions of the storage module 904.
  • FIG. 10 in order to solve the problem of load imbalance in the prior art, another embodiment of the present application provides a data transmission method.
  • the UE and the RAN device are used.
  • the process of the interaction between the AMF instance and the SMF device is described as an example.
  • the AMF instance 1 and the AMF instance 2 belong to the same AMF group.
  • the method includes three phases.
  • the first phase is a session establishment process, and the corresponding step is 1001.
  • the second phase is a process in which the UE enters an idle state, corresponding to step 1004 to step 1007;
  • the third phase is a process in which the UE re-enters the connection state when the SMF device needs to send a downlink message, corresponding to step 1008 to step 1009.
  • the method specifically includes:
  • the UE sends a session establishment request to the AMF instance 1, and the AMF instance 1 receives the session establishment request.
  • the UE sends the session establishment request to the AMF instance 1 to trigger the establishment of the PDU session.
  • the UE initiates the process of establishing the PDU session, the UE is in the connected state, and the UE is serving the AMF instance 1 at this time.
  • the AMF instance 1 sends a session establishment request to the SMF device, and the AMF instance 1 receives the session establishment request.
  • the session establishment request may have the following three implementation manners.
  • the first type the information of the AMF instance 1 is included in the session establishment request.
  • the information of the AMF instance 1 is used by the SMF device to address the AMF instance.
  • the information of the AMF instance 1 may be an AMF instance identifier, a uniform resource identifier (URI) of the service endpoint in the AMF instance, or an AMF instance.
  • the second type the session establishment request includes the information of the AMF instance 1 and the indication information of the AMF group to which the AMF instance 1 belongs.
  • the third type the session establishment request includes the AMF instance 1 information, the stateless indication information, and the indication information of the AMF group to which the AMF instance 1 belongs.
  • the indication information of the AMF group may be an AMF group ID or a default route of the AMF group.
  • the indication information of the AMF group is taken as an example of the AMF group ID.
  • the AMF instance 1 needs to first determine whether the AMF group to which it belongs supports the stateless mode. If the AMF group supports the stateless mode, the AMF instance 1 will be stateless. The indication information is carried in the session establishment request. With reference to FIG. 4, the AMF group supports the stateless mode, that is, the AMF instance does not save the UE session context information when the UE is in the idle state, and the session context information of the idle state UE served by each AMF instance in the AMF group is The AMF instances in the same AMF group can share the UE session context information stored in the DB, so that each AMF instance can process not only related information of the UEs served by itself, but also can be processed. Information about other UEs.
  • the stateless indication information is used to indicate that the SMF device needs to send a downlink message to the AMF instance after the SMF device needs to send the downlink message to the AMF instance, and the SMF device needs to follow the indication information of the AMF group.
  • the AMF instance is reselected from the AMF group and the downstream message is sent to the newly selected AMF instance.
  • the stateless indication information may be a single indication information, for example, carrying a bit in the message to indicate that the AMF group works in the stateless mode, or may be embodied in other manners, for example, carrying a special AMF in the message.
  • the pointer indicates that the AMF group works in stateless mode (for example, if the AMF pointer identifier carried in the message is 1111, the AMF group works in the stateless mode).
  • the binding release of the signaling connection to the first interface includes but is not limited to the following two cases:
  • the first type the signaling connection corresponding to the UE is released, and the binding of the signaling connection to the first interface is also released.
  • the second type the binding of the signaling connection to the first interface is released, and the signaling connection corresponding to the UE is not released.
  • the signaling in the signaling connection may refer to a Next Generation Application Protocol (NGAP) signaling, or may be an N2 reference application protocol (N2AP).
  • NGAP Next Generation Application Protocol
  • N2AP N2 reference application protocol
  • the SMF may further obtain the foregoing stateless indication information from the local configuration information according to the indication information of the AMF group.
  • the SMF device saves information carried in the session establishment request in a UE session context.
  • the session establishment request carries the information of the AMF instance 1, because the AMF instance currently serving the UE is the AMF instance 1, so the SMF device needs The information of the AMF instance 1 is saved in the UE session context, so that when the UE is in the connected state, the SMF device can directly send the downlink message to the AMF instance 1 serving the UE by directly using the information of the AMF instance 1 saved in the UE session context. .
  • the SMF device further needs to save the indication information of the AMF group in the UE session context.
  • the SMF device further needs to save the stateless indication information in the UE session context, or alternatively, the SMF device may save the stateless indication information in the AMF group. Group or AMF corresponding context.
  • the UE session context can be saved in the SMF device or in other devices with storage functions.
  • the above steps 1001 to 1003 are the session establishment process. After the session is established, when the UE enters the idle state, the process of the UE entering the idle state needs to be performed.
  • the RAN device sends a release message to the AMF instance 1, and the AMF instance 1 receives the release message.
  • the release message is used to indicate that the AMF instance 1 releases the binding of the signaling connection corresponding to the UE to the first interface.
  • the AMF instance 1 device releases the binding of the signaling connection corresponding to the UE to the first interface according to the release message.
  • the UE switches from the connected state to the idle state.
  • the AMF instance 1 sends a session update request or a release notification to the SMF device, where the session update request includes a release reason, and the SMF device receives the session update request or the release notification.
  • the reason for the release is used to indicate the reason for the release of the binding of the signaling connection corresponding to the UE to the first interface.
  • the release notification is used to indicate that the binding of the signaling connection corresponding to the UE to the first interface has been released.
  • the session update request message also includes three implementation manners.
  • the session update request may carry the indication information and the release reason of the AMF group to which the AMF instance 1 belongs.
  • the optional session update request may also carry stateless indication information.
  • the session update request may carry the release reason.
  • the optional session update request may also carry stateless indication information.
  • the third type If the session establishment request is the third implementation manner described in step 1002, the session update request message may carry the release reason.
  • the AMF instance 1 is to carry the stateless indication information in the session update request message, it is necessary to first determine whether the AMF group to which it belongs supports the stateless mode. If the AMF group supports the stateless mode, the AMF instance 1 The stateless indication information will be carried in the session update request.
  • the release notification also includes the above three implementations.
  • the AMF instance 1 may also send a notification that the UE enters the idle state to the SMF device. Similarly, entering the idle state notification also includes the above three implementations.
  • the SMF device determines, according to the release reason, the release notification, or the UE to enter the idle state notification, that the binding connection of the signaling connection corresponding to the UE and the first interface is released.
  • the SMF device deletes information of the AMF instance 1 in the UE session context according to the stateless indication information.
  • the SMF device directly deletes the information of the AMF instance 1 in the UE session context according to the stateless indication information carried in the session update request. If the state update indication message is not carried in the session update request message, and the stateless indication information is saved in the UE session context, the SMF device deletes the information of the AMF instance 1 according to the stateless indication information saved in the UE session context. In addition, the SMF device can obtain the stateless indication information from the local configuration information according to the information of the configured AMF group, and delete the information of the AMF strength 1 according to the stateless indication information in the local configuration information.
  • the SMF device determines that the UE has entered the idle state according to the received session update request or the release notification or according to the received UE entering the idle state notification. At this time, the SMF device deletes the information of the AMF instance 1 in the UE session context, and the UE can be avoided. Upon re-entering the connection state, the SMF device still uses AMF instance 1 as the AMF instance serving the UE according to the information of AMF instance 1 in the UE session context. At this time, since the AMF instance 1 information does not exist in the UE session context, the AMF instance serving as the UE can only be re-selected in the AMF group, and the same AMF instance is always used to serve the UE.
  • the SMF device does not delete the information of the AMF instance 1 in step 1007, and the SMF device determines that the UE has entered the idle state according to receiving the session update request or the release notification or according to the received UE entering the idle state notification. State, the SMF device sets the UE's Connection Management (CM) state to the idle state.
  • CM Connection Management
  • steps 1004 to 1007 are the process of the UE entering the idle state. If the subsequent SMF device receives the downlink message for the UE, the following steps 1008 to 1009 are also performed to enable the UE to re-enter the connection state.
  • the SMF device When the SMF device needs to send a downlink message, the SMF device selects an AMF instance serving as the UE from the AMF group according to the AMF group ID, for example, AMF instance 2.
  • the SMF device when the SMF device needs to send the downlink message, it may be determined whether the binding of the signaling connection corresponding to the UE and the first interface is released, and if it is determined that the binding of the signaling connection corresponding to the UE to the first interface is released, According to the AMF group ID, an AMF instance serving the UE is selected from the AMF group.
  • the SMF device queries the UE session context. If the information of the AMF instance is not saved in the UE session context, the SMF device selects an AMF instance serving the UE according to the AMF group ID.
  • the SMF device determines that the CM status of the UE is in an idle state, and the SMF device receives the stateless indication information from the AMF instance 1 (as in step 1001 or 1006) or the SMF device determines the AMF group according to the configuration.
  • the SMF device selects an AMF instance serving the UE according to the AMF group ID even if the AMF instance information is saved in the UE session context.
  • the SMF device may look up an AMF instance serving the UE from a Network Function Repository Function (NRF) device or other device according to the AMF group ID.
  • NRF Network Function Repository Function
  • the specific method for the SMF device to select an AMF instance for serving the UE according to the AMF group ID is the same as that of the prior art, and details are not described herein again.
  • the SMF device may save the information of the AMF instance 2 in the UE session context after reselecting the AMF instance 2 serving the UE, so that the SMF device directly communicates with the AMF instance 2 when the UE is always in the connected state. There is no need to re-select the AMF instance.
  • the SMF device sends a downlink message to the AMF instance 2, and the AMF instance 2 receives the downlink message.
  • the AMF instance 2 may also re-select an AMF instance for the UE, for example, AMF instance 3, and send the message to the AMF instance 3.
  • the downlink message, or the identifier of the AMF instance 3 is sent to the SMF device, and the SMF device sends a downlink message to the AMF instance 3.
  • the method for transmitting a message provided by the embodiment of the present application is that the SMF device in the prior art always selects an AMF instance that is served by the UE to provide a service for the UE.
  • the RAN is released in the RAN.
  • the SMF device deletes the information of the AMF instance in the UE context, and then the SMF device needs to send the UE for the UE.
  • the downlink message When the downlink message is used, it is impossible to directly search for the information of the AMF instance that was last served for the UE from the UE context, and instead of continuing to select the AMF instance that was last served for the UE, the AMF instance is reselected, thus avoiding The SMF device always selects the load imbalance caused by the last AMF instance served for the UE.
  • the embodiment of the present application provides a device for message transmission, and the device can be implemented as the SMF device in the above embodiment.
  • FIG. 11 shows another possible structural diagram of the SMF device involved in the above embodiment.
  • the SMF device includes an acquisition module 1101 and a transmission module 1102.
  • the obtaining module 1101 is configured to obtain the stateless indication information and the group indication information of the group to which the first device belongs, where the stateless indication information is used to indicate that after determining that the binding of the signaling connection corresponding to the user equipment UE and the first interface is released
  • the second device that is used for serving the UE is selected according to the group indication information, where the first device is a device that serves the UE before the binding of the signaling connection and the first interface is released, and the first interface is a wireless connection. The interface between the incoming network RAN and the first device.
  • the sending module 1102 is configured to: when the obtaining module 1101 receives the release notification from the first device, when the downlink message needs to be sent, send a downlink message to the second device, where the second device is determined according to the group indication information.
  • the release notification is used to indicate that the binding of the signaling connection corresponding to the UE to the first interface has been released.
  • the apparatus further includes a determining module 1103.
  • the determining module 1103 is configured to determine binding release of the signaling connection corresponding to the UE and the first interface.
  • the determining module 1103 is further configured to: if the sending module needs to send a downlink message, and the determining module 1103 determines that the signaling connection corresponding to the UE is released from the first interface, Then determining a second device for serving the UE according to the group indication information.
  • the acquiring module 1101 is specifically configured to receive a session establishment request from the first device, where the session establishment request includes the group indication information; or, the receiving is from the first A release notification of the device, and the group notification information is included in the release notification.
  • the acquiring module 1101 is configured to receive a session establishment request from the first device, where the session establishment request includes stateless indication information, or receive the information from the first device.
  • the release notification includes the stateless indication information; or the stateless indication information is obtained from the local configuration information.
  • the apparatus further includes a deleting module 1104.
  • the deleting module 1104 is configured to delete the information of the first device in the UE session context according to the stateless indication information after the obtaining module 1101 receives the release notification from the first device.
  • the device further includes: a storage module 1105.
  • the storage module 1105 is configured to save the release state of the binding of the signaling connection and the first interface after the obtaining module 1101 receives the release notification from the first device.
  • the determining module 1103 is further configured to determine that the binding of the signaling connection to the first interface is released according to the release state of the binding of the signaling connection with the first interface;
  • the determining module 1103 is further configured to: if the sending module 1102 needs to send a downlink message, and the determining module 1103 determines that the binding of the signaling connection to the first interface is released according to the release state of the binding of the signaling connection with the first interface. And determining, according to the group indication information, a second device for serving the UE.
  • the group indication information is a group identity ID of the group to which the first device belongs;
  • the determining module 1103 is specifically configured to: if the sending module 1102 needs to send a downlink message, and the determining module 1103 determines that the binding of the signaling connection to the first interface is released according to the release state of the binding of the signaling connection and the first interface, The group ID is determined to be the second device served by the UE.
  • the acquiring module 1101 is configured to support the SMF device to obtain the session establishment request sent by step 1002 in FIG. 10, and the first interface sent by the step 1006 releases the message.
  • the sending module 1102 is configured to support the SMF device to perform step 1009 in FIG.
  • the deleting module 1104 is configured to support the SMF device to perform step 1007 in FIG.
  • the determining module 1103 is configured to support the SMF device to perform step 1008 in FIG.
  • the storage module 1105 is configured to support the SMF device to perform step 1003 in FIG.
  • the obtaining module 1101 and the transmitting module 1102 shown in FIG. 11 may be integrated in the communication interface 503 shown in FIG. 5, so that the communication interface 503 executes the obtaining module 1101 and transmits.
  • the determination module 1103 and the deletion module 1104 can be integrated into the processor 502 shown in FIG. 5, causing the processor 502 to perform the specific functions of the determination module 1103 and the deletion module 1104.
  • the storage module 1105 can be integrated in the memory 501 shown in FIG. 5 to cause the memory 501 to perform the specific functions of the storage module 1105.
  • Embodiments of the present application also provide a computer storage medium for storing computer software instructions for use in the above-described SMF device, the device comprising a program designed to perform the steps performed by the SMF device in the above embodiment.
  • Embodiments of the present application also provide a computer program product, such as a computer readable storage medium, including a program designed to perform the steps performed by the SMF device in the above-described embodiments.
  • the steps of a method or algorithm described in connection with the present disclosure may be implemented in a hardware or may be implemented by a processor executing software instructions.
  • the software instructions may be composed of corresponding software modules, which may be stored in a random access memory (RAM), a flash memory, a read only memory (ROM), an erasable programmable read only memory ( Erasable Programmable ROM (EPROM), electrically erasable programmable read only memory (EEPROM), registers, hard disk, removable hard disk, compact disk read only (CD-ROM) or any other form of storage medium known in the art.
  • An exemplary storage medium is coupled to the processor to enable the processor to read information from, and write information to, the storage medium.
  • the storage medium can also be an integral part of the processor.
  • the processor and the storage medium can be located in an ASIC. Additionally, the ASIC can be located in a core network interface device.
  • the processor and the storage medium may also exist as discrete components in the core network interface device.
  • the disclosed system, apparatus, and method may be implemented in other manners.
  • the device embodiments described above are merely illustrative.
  • the division of the unit is only a logical function division.
  • there may be another division manner for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed.
  • the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be electrical or otherwise.
  • the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network devices. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.
  • each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each functional unit may exist independently, or two or more units may be integrated into one unit.
  • the above integrated unit can be implemented in the form of hardware or in the form of hardware plus software functional units.
  • the present application can be implemented by means of software plus necessary general hardware, and of course, by hardware, but in many cases, the former is a better implementation. .
  • the technical solution of the present application which is essential or contributes to the prior art, may be embodied in the form of a software product stored in a readable storage medium, such as a floppy disk of a computer.
  • a hard disk or optical disk, etc. includes instructions for causing a computer device (which may be a personal computer, server, or network device, etc.) to perform the methods described in various embodiments of the present application.

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Abstract

本申请公开了一种消息传输的方法及装置，涉及通信技术领域，能够解决为UE服务的设备间负载不均衡的问题。本申请的方法包括：会话管理功能设备接收来自第一设备的删除指示和第一设备所属的群组的指示信息，在会话管理功能设备接收到来自第一设备的第一接口释放消息的情况下，根据删除指示删除UE会话上下文中的第二接口信息，然后，当需要发送下行消息时，会话管理功能设备向第二设备发送下行消息，第二设备为根据群组的指示信息确定的用于为所述UE服务的设备。本申请适用于消息传输的过程中。

Description

一种消息传输的方法及装置
本申请要求了2017年5月3日提交的、申请号为201710305752.2、发明名称为“一种消息传输的方法及装置”的中国申请的优先权，以及2018年4月3日提交的、申请号为201810289567.3、发明名称为“一种消息传输的方法及装置”的中国申请的优先权，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，尤其涉及一种消息传输的方法及装置。
背景技术
在第四代移动通信技术(the 4th Generation mobile communication，4G)中，服务网关(Serving GateWay，SGW)可以保存用户设备(User Equipment，UE)的会话上下文，UE的会话上下文中包含为该UE服务的移动性管理网元(Mobility Management Entity，MME)的IP地址，当SGW需要向MME发送与UE相关的下行消息时，可以从保存的该UE的会话上下文中获取服务于该UE的MME的IP地址，进而根据获取到的IP地址向该MME发送与该UE相关的下行消息。
如果在第五代移动通信技术(5th-Generation mobile communication，5G)的会话管理功能(Session Management Function，SMF)中也采用这种方法，即SMF中保存了UE会话上下文，UE会话上下文中包含为UE服务的接入和移动性管理功能(Core Access and Mobility Management Function，AMF)中的处理单元(或者为UE服务的AMF实例)的对外接口信息，当SMF需要发送与UE相关的下行消息时，会根据UE的会话上下文获取上次为UE服务的AMF中的处理单元(或者为UE服务的AMF实例)的对外接口信息，进而根据获取到的对外接口信息，将与UE相关的下行消息发送给上次为该UE服务的AMF中的处理单元(或者为UE服务的AMF实例)。
然而采用这种方法，SMF每次需要发送与UE相关的下行消息时，都会将下行消息发送给上次为该UE服务的AMF中的处理单元(或者为UE服务的AMF实例)，会使得UE一直由同一个处理单元或AMF实例服务，会出现负载不均衡的现象。
发明内容
本申请实施例提供一种消息传输的方法及装置，能够解决会话管理功能设备每次都将UE相关下行消息发送至上次为该UE服务的第一设备，导致的负载不均衡的问题。
为达到上述目的，本申请采用如下技术方案：
第一方面，本申请提供一种消息传输的方法，该方法包括：
会话管理功能设备接收来自第一设备的删除指示和第一设备所属的群组的指示信息，在会话管理功能设备接收到来自第一设备的第一接口释放消息的情况下，会话管理功能设备根据删除指示删除UE会话上下文中的第二接口信息，然后，当会话管理功能设备需要发 送下行消息时，会话管理功能设备向第二设备发送所述下行消息，第二设备为根据群组的指示信息确定的用于为所述UE服务的设备。
其中，所述删除指示用于指示会话管理功能设备在收到第一接口释放消息时，删除用户设备UE会话上下文中的第二接口信息，所述第一接口为无线接入网RAN与所述第一设备间的接口，所述第二接口为所述第一设备与所述会话管理功能设备间的接口。
会话管理功能设备可以为AMF设备，第一设备和第二设备均可以为AMF群组中的一个实例，或者第一设备和第二设备均可以为AMF设备中的一个处理单元。
相比于现有技术，会话管理功能设备在第一设备的第一接口释放的情况下，会删除UE会话上下文中的第二接口信息，然后当会话管理功能设备需要发送下行消息时，就无法从UE上下文中查找上一次为该UE服务的第一设备的接口信息，进而就可以触发重新选取为UE服务的第二设备的过程，会话管理功能设备即可将下行消息发送给第二设备，避免了总是由同一个设备为UE提供服务而出现的负载不均衡的现象。
在一种可能的设计中，会话管理功能设备接收来自第一设备的删除指示和第一设备所属的群组的指示信息，具体可以实现为：会话管理功能设备接收来自第一设备的会话建立请求，会话建立请求中包括群组的指示信息、删除指示以及第二接口信息。
在会话管理功能设备接收来自第一设备的会话建立请求之后，会话管理功能设备可以将群组的指示信息，删除指示以及第二接口信息保存在所述UE会话上下文中。
将第二接口信息保存在UE会话上下文中，在UE未切换至空闲状态之前，会话管理功能设备就可以直接根据第二接口信息与为UE服务的第一设备进行通信，无需频繁地重选为UE服务的设备，可以提高UE处于连接状态时的业务质量。将删除指示保存在UE会话上下文中，会话管理功能设备就可以在接收到第一接口的释放消息时，及时删除UE会话上下文中的第二接口信息，以避免每次UE进入连接状态都由同一个设备服务，解决了现有技术中的负载不均衡的问题。
在一种可能的设计中，会话管理功能设备根据删除指示删除UE会话上下文中的第二接口信息，具体可以实现为：会话管理功能设备根据UE会话上下文中的删除指示，删除UE会话上下文中的第二接口信息。
在一种可能的设计中，会话管理功能设备接收来自第一设备的删除指示和第一设备所属的群组的指示信息，具体可以实现为：会话管理功能设备接收来自第一设备的会话建立请求，会话建立请求中包括所述群组的指示信息和所述第二接口信息，然后会话管理功能设备接收来自第一设备的第一接口释放消息，第一接口释放消息中包括删除指示。
在会话管理功能设备接收来自第一设备的会话建立请求之后，会话管理功能设备可以将群组的指示信息和第二接口信息保存在UE会话上下文中。
将第二接口信息保存在UE会话上下文中，在UE未切换至空闲状态之前，会话管理功能设备就可以直接根据第二接口信息与为UE服务的第一设备进行通信，无需频繁地重选为UE服务的设备，可以提高UE处于连接状态时的业务质量。
在一种可能的设计中，会话管理功能设备接收来自第一设备的删除指示和第一设备所属的群组的指示信息，具体可以实现为：会话管理功能设备接收来自第一设备的第一接口释放消息，第一接口释放消息中包括群组的指示信息和所述删除指示。
在会话管理功能设备接收来自第一设备的第一接口释放消息之前，会话管理功能设备接收来自第一设备的会话建立请求，会话建立请求中包括所述第二接口信息，然后会话管理功能设备将所述第二接口信息保存在UE会话上下文中。
第一接口释放消息中携带删除指示，可以使得会话管理功能设备在接收到第一接口释放消息的情况下，及时删除UE会话上下文中的第二接口信息，以避免每次UE进入连接状态都由同一个设备服务，解决了现有技术中的负载不均衡的问题。
在一种可能的设计中，会话管理功能设备根据删除指示删除UE会话上下文中的第二接口信息，具体可以实现为：会话管理功能设备根据第一接口释放消息中包括的删除指示删除UE的会话上下文中的第二接口信息。
在一种可能的设计中，群组的指示信息为群组的群组身份标识ID；会话管理功能设备可以根据群组ID确定为UE服务的第二设备，然后会话管理功能设备通过会话管理功能设备与第二设备之间的接口向第二设备发送下行消息。
在一种可能的设计中，群组的指示信息为群组的缺省路由；当会话管理功能设备需要发送下行消息时，会话管理功能设备向群组的缺省路由对应的设备发送下行消息，然后接收来自群组的缺省路由对应的设备的第二设备标识，第二设备为群组的缺省路由对应的设备为UE选择的第二设备，进而会话管理功能设备通过会话管理功能设备与第二设备之间的接口，向第二设备标识对应的第二设备发送下行消息。
在一种可能的设计中，群组的指示信息为群组的缺省路由；当会话管理功能设备需要发送下行消息时，会话管理功能设备通过群组的缺省路由对应的设备向第二设备发送下行消息，第二设备为群组的缺省路由对应的设备为UE选择的第二设备。
在一种可能的设计中，在会话管理功能设备通过群组的缺省路由对应的设备向第二设备发送下行消息之后，当会话管理功能设备接收到来自所述第二设备的消息后，会话管理功能设备将会话管理功能设备与第二设备之间的接口信息保存在UE会话上下文中。
通过将会话管理功能设备与第二设备之间的接口信息保存在UE会话上下文中，在UE切换至空闲状态之前，会话管理功能设备就不需要在每次发送该UE的下行消息时都重新选择为UE服务的设备，可以节省开销，避免由于重选为UE服务的设备而导致UE业务中断的情况。
第二方面，本申请提供了一种消息传输的方法，该方法包括：
会话管理功能设备获取无状态指示信息和第一设备所属群组的群组指示信息，无状态指示信息用于指示会话管理功能设备在确定用户设备UE对应的信令连接与第一接口的绑定释放后需要发送下行消息时，根据群组指示信息选择用于为UE服务的第二设备，然后，在会话管理功能设备接收到来自第一设备的释放通知的情况下，当会话管理功能设备需要发送下行消息时，会话管理功能设备向第二设备发送下行消息。其中，第一设备为信令连接与第一接口的绑定释放前为UE服务的设备，第一接口为无线接入网RAN与第一设备间的接口，第二设备为根据群组指示信息确定的用于为UE服务的设备。释放通知用于表示信令连接与第一接口的绑定已释放。
会话管理功能设备可以为AMF设备，第一设备和第二设备均可以为AMF群组中的一个 实例，或者第一设备和第二设备均可以为AMF设备中的一个处理单元。第一设备所属的群组的群组指示信息可以为AMF群组ID，也可以为AMF群组的缺省路由。
其中，信令连接与第一接口的绑定释放包括但不限于以下两种情况：
第一种：UE对应的信令连接释放，且信令连接与第一接口的绑定也释放。
第二种：信令连接与第一接口的绑定释放，UE对应的信令连接不释放。
相比于现有技术，会话管理功能设备在确定UE对应的信令连接与第一接口的绑定已释放，且需要发送下行消息的情况下，可以向重新选择的用于为UE服务的第二设备发送下行消息，这样就避免了总是由同一个设备为UE提供服务而出现的负载不均衡的现象。
在一种可能的设计中，会话管理功能设备在向第二设备发送下行消息之前，会话管理功能设备可确定UE对应的信令连接与第一接口的绑定释放。
在一种可能的设计中，若会话管理功能模块需要发送下行消息，且确定UE对应的信令连接与第一接口的绑定释放，则根据群组指示信息确定用于为UE服务的第二设备。
采用该方法，在会话管理功能设备确定UE的信令连接与第一接口的绑定释放的情况下，确定为UE服务的第二设备，可以避免始终由第一设备为终端提供服务，在后续会话管理功能设备需要发送下行消息时，可通过第二设备向终端发送下行消息。
在一种可能的设计中，会话管理功能设备获取第一设备所属群组的群组指示信息，具体可以实现为：
会话管理功能设备接收来自第一设备的会话建立请求，会话建立请求中包括群组指示信息；或者，会话管理功能设备接收来自第一设备的释放通知，释放通知中包括群组指示信息。
在一种可能的设计中，会话管理功能设备获取无状态指示信息，包括：
会话管理功能设备接收来自第一设备的会话建立请求，会话建立请求中包括无状态指示信息；或者，会话管理功能设备接收来自第一设备的释放通知释放通知中包括无状态指示信息；或者，会话管理功能设备从本地配置信息中获取无状态指示信息。
在另一种可能的设计中，释放通知中包括删除指示。其中，删除指示用于指示会话管理功能设备删除第一设备的信息。
采用该方法，会话管理功能设备在UE对应的的信令连接与第一接口的绑定释放的情况下，会删除UE会话上下文中的第一设备的信息信息，然后当会话管理功能设备需要发送下行消息时，就无法从UE上下文中查找上一次为该UE服务的第一设备的信息，进而就可以触发重新选取为UE服务的第二设备的过程，会话管理功能设备即可将下行消息发送给第二设备，避免了总是由同一个设备为UE提供服务而出现的负载不均衡的现象。
在一种可能的设计中，在会话管理功能设备接收到来自第一设备的释放通知后，会话管理功能设备根据无状态指示信息删除UE会话上下文中的第一设备的信息。
在另一种可能的设计中，在会话管理功能设备接收到来自第一设备的释放通知后，会话管理功能设备保存信令连接与第一接口的绑定的释放状态，然后当会话管理功能设备需要发送下行消息时，会话管理功能根据信令连接与第一接口的绑定的释放状态确定信令连接与第一接口的绑定已释放，然后会话管理功能根据群组指示信息确定用于为UE服务的第二设备。
采用该方法，信令连接与第一接口的绑定释放后，会话管理功能设备可以保存信令连接与第一接口的绑定的释放状态，进而，如果会话管理功能设备需要发送下行消息，则确定用于为UE服务的第二设备，避免始终使用第一设备为UE提供服务而导致负载不均衡，若会话管理功能后续不需要发送下行消息，则无需确定用于为UE服务的第二设备，可以节省系统开销。
在另一种可能的设计中，群组指示信息为第一设备所属群组的群组身份标识ID；相应的，会话管理功能设备向第二设备发送下行消息，具体可以实现为：若会话管理功能设备需要发送下行消息，且确定UE对应的信令连接与第一接口的绑定已释放，则根据群组ID确定为UE服务的第二设备。
第三方面，本申请提供了一种消息传输的装置，该装置可以实现上述第一方面或第二方面中会话管理功能设备所执行的功能，所述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。所述硬件或软件包括一个或多个上述功能相应的模块。
在一种可能的设计中，该装置的结构中包括处理器和通信接口，该处理器被配置为支持该装置执行上述方法中相应的功能。该通信接口用于支持该装置与其他网元之间的通信。该装置还可以包括存储器，该存储器用于与处理器耦合，其保存该装置必要的程序指令和数据。
第四方面，本申请提供一种消息传输的系统，该系统包括第一方面或第二方面的会话管理功能设备、UE、RAN以及第一设备所属的群组。
第五方面，本申请提供了一种计算机存储介质，用于储存为上述会话管理功能设备所用的计算机软件指令，其包括用于执行上述方面所设计的程序。
第六方面，本申请提供一种计算机程序产品，例如计算机可读存储介质，包括用于执行上述方面所设计的程序。
相比于现有技术，会话管理功能设备在第一设备的第一接口释放的情况下，会删除UE会话上下文中的第二接口信息，然后当会话管理功能设备需要发送下行消息时，就无法从UE上下文中查找上一次为该UE服务的第一设备的接口信息，进而就可以触发重新选取为UE服务的第二设备的过程，会话管理功能设备即可将下行消息发送给第二设备，避免了总是由同一个设备为UE提供服务而出现的负载不均衡的现象。
附图说明
图1为本申请提供的一种通信系统的结构示意图；
图2为本申请提供的另一种通信系统的结构示意图；
图3为本申请提供的一种AMF设备的结构示意图；
图4为本申请提供的另一种AMF设备的结构示意图；
图5为本申请提供的一种SMF设备的结构示意图；
图6为本申请提供的一种消息传输的方法的流程图；
图7为本申请提供的另一种消息传输的方法的流程图；
图8为本申请提供的另一种消息传输的方法的流程图；
图9为本申请提供的一种消息传输的装置的结构示意图；
图10为本申请提供的另一种消息传输的方法的流程图；
图11为本申请提供的另一种消息传输的装置的结构示意图。
具体实施方式
本申请描述的系统架构以及业务场景是为了更加清楚的说明本申请的技术方案，并不构成对于本申请提供的技术方案的限定，本领域普通技术人员可知，随着系统架构的演变和新业务场景的出现，本申请提供的技术方案对于类似的技术问题，同样适用。
需要说明的是，本申请中，“示例性的”或者“例如”等词用于表示作例子、例证或说明。本申请中被描述为“示例性的”或者“例如”的任何实施例或设计方案不应被解释为比其他实施例或设计方案更优选或更具优势。确切而言，使用“示例性的”或者“例如”等词旨在以具体方式呈现相关概念。
需要说明的是，本申请中“的(英文：of)”，相应的“(英文corresponding，relevant)”和“对应的(英文：corresponding)”有时可以混用，应当指出的是，在不强调其区别时，其所要表达的含义是一致的。
在详细描述本申请的技术方案之前，为了便于理解，先对本申请的实施例所应用的场景进行介绍。
本申请的实施例应用于如图1所示的通信系统中，该系统中包括会话管理功能设备101，接入和移动性管理功能设备102，以及接入网设备103。
其中，接入和移动性管理功能设备102中包括多个设备，例如，可以包含第一设备和第二设备，接入和移动性管理功能设备102中还可以包括ASF单元，ASF单元为一个网络功能，具体可以为图3所示的一个缺省AMF实例，或者也可以为一个专门的网络功能，例如可以为一个负载均衡器。
会话管理功能设备101，用于接收来自第一设备的删除指示和第一设备所属的群组的指示信息，其中，第一设备为接入和移动性管理功能设备102中当前为UE服务的设备，第一设备所属的群组为接入和移动性管理功能设备102。
接入和移动性管理功能设备102中的第一设备，用于向会话管理功能设备101发送第一接口释放消息，第一接口为接入网设备103与第一设备间的接口。
会话管理功能设备101，还用于在接收到来自第一设备的第一接口释放消息的情况下，根据删除指示删除UE会话上下文中的第二接口信息，第二接口为第一设备与会话管理功能设备101之间的接口。然后当会话管理功能设备101需要发送下行消息时，可以向第二设备发送下行消息，第二设备为根据群组的指示信息确定的用于为所述UE服务的设备。
需要说明的是，本申请所涉及到的UE可以包括各种具有无线通信功能的手持设备、车载设备、可穿戴设备、计算设备或连接到无线调制解调器的其它处理设备，以及各种形式的终端，移动台(Mobile Station，MS)，用户设备(User Equipment，UE)，终端设备(Terminal Equipment)，软终端等等。为方便描述，本申请中，上面提到的设备统称为UE。
另外，本申请适用于5G网络，当本申请应用于5G网络时，通信系统的架构图如图2所示，该系统中包括认证服务器功能(Authentication Server Function，AUSF)设备、统一数据管理(Unified Data Management，UDM)设备、AMF设备、SMF设备、策略控制功能 (Policy Control function，PCF)设备、UE、无线接入网(Radio Access Network，RAN)或者接入网(Access Network，AN)、用户面功能(User Plane Function，UPF)设备、数据网络(Data Network，DN)设备。
其中，图1中的会话管理功能设备101可以实现为图2中的SMF设备，图1中的接入和移动管理功能设备102可以实现为图2中的AMF设备，图1中的接入网设备103可以实现为图2中的RAN或AN。下文中均以会话管理功能设备101为SMF设备、接入和移动管理功能设备102为AMF设备、接入网设备103为RAN为例进行描述。
AMF设备可以服务于UE，为UE的接入进行授权及管理UE的移动性，同时，AMF设备还用于在UE与SMF间传递非接入层(Non Access Stratum，NAS)消息等。RAN能够与UE和AMF设备通信，例如，RAN接收到UE发送的NAS消息之后，可以将该NAS消息转发给AMF设备。SMF设备可以与AMF设备进行通信，例如可以向AMF设备发送下行消息等。SMF设备还用于对会话进行管理，例如SMF设备可以维护UE会话上下文中的AMF设备与SMF设备之间的接口信息，以便于SMF设备在收到针对某一UE的下行消息时，可以直接根据该UE的会话上下文中存储的接口信息确定为该UE服务的AMF设备。
其中，图2中各设备之间的连线上标注的序号用于区分不同设备之间的接口，图2仅为一种示例性示意图，本申请并不对各设备间接口的序号进行限制。示例性的，图2中UE通过N1接口与AMF进行通信，RAN通过N2接口与AMF进行通信，通过N3接口与UPF进行通信，各UPF之间通过N9接口进行通信，UPF通过N6接口与DN互联。SMF通过N4接口控制SMF，AMF通过N11接口与SMF进行通信，AMF和SMF分别通过N8接口和N10接口从UDM获取用户签约数据，分别通过N15接口和N7接口从PCF获取策略数据。另外，AMF设备间通过N14接口进行通信，AUSF通过N12接口与AMF进行通信，通过N13接口与UDM进行通信。
需要说明的是，图1和图2仅为本申请所应用的通信系统的结构示意图，在实际部署过程中，通信系统中设备的数量不限于图1和2所示出的设备数量。另外，图1至图2中的各个设备均可能由一个实体设备实现，也可能由多个实体设备共同实现，还可能是一个实体设备内的一个逻辑功能模块，本申请实施例对此不作具体限定。
还需说明的是，上述5G网络中的UE、RAN、AMF设备、SMF设备、AUSF设备和UDM设备等仅是一个名字，名字对设备本身不构成限定。在5G网络以及未来其它的网络中，UE、RAN、AMF设备、SMF设备、AUSF设备和UDM设备所对应的网元或实体也可以是其他的名字，本申请实施例对此不作具体限定。例如，该UDM设备还有可能被替换为用户归属服务器(Home Subscriber Server，HSS)或者用户签约数据库(User Subscription Database，USD)或者数据库实体，等等，在此进行统一说明，以下不再赘述。
需要说明的是，图2中的AMF设备可以有两种实现方式，第一种实现方式如图3所示，图3示出了其中一个AMF设备，AMF设备中包含数据库(Database，DB)、至少一个负载均衡(Load Balancer，LB)单元以及至少两个处理单元。其中，LB单元用于为UE选择处理单元，并将接收到的NAS消息分发至相应的处理单元，处理单元用于处理接收到的NAS等消息，多个处理单元可以共享数据库中的数据。
具体的，每个LB单元和处理单元都有对外的接口，在RAN设备初始化时，会将AMF 设备中LB单元的对外接口作为AMF设备的对外接口配置在RAN设备中，当RAN设备接收到处于空闲状态的UE发送的NAS消息后，RAN设备先选择一个AMF设备，然后从该AMF设备配置在RAN设备中的LB单元接口中选择一个，然后通过选择的LB单元接口将NAS消息发送至AMF设备中的LB单元，LB单元接收到该NAS消息后，为该NAS消息分配一个处理单元。当UE处于连接状态时，RAN设备可直接与该处理单元进行通信，无需再通过LB单元转发数据。
图2中的AMF设备还可以以群组的方式实现，如图4所示，AMF群组中包含数据库、至少一个LB单元以及至少两个AMF实例。其中，LB单元用于为UE选择AMF实例，并将接收到的NAS消息分发至相应的AMF实例，AMF实例用于处理接收到的NAS等消息，多个AMF实例可以共享数据中的数据。
具体的，每个LB单元和AMF实例都有对外的接口，在RAN设备初始化时，会将LB单元的对外接口作为AMF群组的对外接口配置在RAN设备中，当RAN设备接收到处于空闲状态的UE发送的NAS消息后，RAN设备会选择一个AMF群组，然后选择该AMF群组的一个LB单元接口，通过该LB单元接口将NAS消息发送至AMF群组中的LB单元，LB单元接收到该NAS消息后，为该NAS消息分配一个AMF实例。当UE处于连接状态时，RAN设备可直接与该AMF实例进行通信，无需再通过LB单元转发数据。
在现有技术中，在LB单元为UE选择处理单元或者AMF实例之后，SMF设备会将建立会话或者会话激活时为UE服务的处理单元或者AMF实例的对外接口信息保存在UE会话上下文中，当SMF设备需要发送下行消息时，SMF设备总是根据UE会话上下文中保存的上次为UE服务的处理单元或AMF实例的对外接口信息，将下行消息发送给上次为该UE服务的处理单元或者AMF实例。这样就使得即使UE从空闲状态切换至连接状态的过程中也不会触发对处理单元或者AMF实例的重选过程，在SMF设备的UE会话上下文中保存为UE服务的处理单元或者AMF实例之后，该UE会始终由同一个处理单元或者AMF实例服务，即使上次为该UE服务的AMF实例的负载很大，而AMF群组中的其他AMF实例的负载很小，AMF依然会将下行消息发送给上次为该UE服务的AMF实例，容易出现负载不均衡的现象。
为了避免出现负载不均衡的现象，本申请的原理为：当图2中的AMF设备实现为图3时，AMF设备中的处理单元在向SMF设备发送的会话建立请求或N2释放消息中携带删除指示和SMF标识，进而在SMF设备接收到N2释放消息的情况下，SMF设备就能够根据删除指示删除UE会话上下文中的处理单元与SMF设备之间的接口信息，这样当SMF设备需要发送下行消息时，由于UE会话上下文中已经没有处理单元与SMF设备之间的接口信息，所以SMF设备只能向根据AMF标识重新选择的处理单元发送下行消息，就避免了每次都向同一个处理单元发送下行消息而出现的负载不均衡的问题。
同样，当图2中的AMF实现为图4时，AMF群组中的AMF实例在向SMF设备发送的会话建立请求或者N2释放消息中携带删除指示和AMF群组标识，进而在SMF设备接收到N2释放消息的情况下，SMF设备就能够根据删除指示删除UE会话上下文中的AMF实例与SMF设备之间的接口信息，这样当SMF设备需要发送下行消息时，由于UE会话上下文中已经没有AMF实例与SMF设备之间的接口信息，所以SMF设备只能根据AMF群组标识向重新选择的AMF实例发送下行消息，就避免了每次都向同一个AMF实例发送下行消息而出现的 负载不均衡的问题。
在本申请的实施例中，图1和图2中的SMF设备的结构如图5所示，SMF设备可以包括：存储器501、处理器502、通信接口503以及总线504，总线504用于实现这些装置之间的连接和相互通信。
其中，通信接口503，可以由天线来实现，可用于与外部网元之间进行数据交互，如：SMF设备的通信接口503可收发与AMF设备间的数据包或其他信息。
处理器502，可能是中央处理器(英文：Central Processing Unit，CPU)，也可以是特定集成电路(英文：Application Specific Integrated Circuit，ASIC)，或者是被配置成实施本发明实施例的一个或多个集成电路。例如：一个或多个微处理器(英文：Digital Singnal Processor，DSP)，或，一个或者多个现场可编程门阵列(英文：Field Programmable Gate Array，FPGA)。处理器502具有处理管理功能，具体的，SMF设备中的处理器502可以对接收到的AMF设备、UPF设备或PCRF设备发送的数据或信息进行处理，或者对其他设备发送的信息或数据进行处理。
存储器501，可以是只读存储器(Read-Only Memory，ROM)或可存储静态信息和指令的其他类型的静态存储设备，随机存取存储器(Random Access Memory，RAM)或者可存储信息和指令的其他类型的动态存储设备，也可以是电可擦可编程只读存储器(Electrically Erasable Programmable Read-Only Memory，EEPROM)、只读光盘(Compact Disc Read-Only Memory，CD-ROM)或其他光盘存储、光碟存储(包括压缩光碟、激光碟、光碟、数字通用光碟、蓝光光碟等)、磁盘存储介质或者其他磁存储设备、或者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。存储器501可以是独立存在，通过总线504与处理器502相连接。存储器501也可以和处理器502集成在一起。
以下将结合图1至图5所示的通信系统以及AMF设备和SMF设备对本申请提供的消息传输的方法进行具体阐述。
首先，对本申请涉及到的术语进行简单介绍，以方便理解。
1)、第一接口
第一接口为图2所示的AMF设备与RAN设备之间的接口(对应图2中的N2)。
2)、第二接口
第二接口为图2所示的AMF设备与SMF设备之间的接口，具体为AMF设备中正在为UE服务的第一设备与SMF设备之间的接口。
3)、第一设备
当图2中的AMF设备实现为图3时，第一设备为AMF设备中的一个处理单元，第一设备所属的群组为处理单元所在的AMF设备,第二接口为AMF设备中的一个处理单元与SMF设备之间的接口(对应图2中的N11)。
当图2中的AMF设备实现为图4所示的AMF群组时，第一设备为AMF群组中的一个AMF实例，第一设备所属的群组为AMF实例所在的AMF群组，第二接口为AMF群组中的一个AMF实例与SMF设备之间的接口(对应图2中的N11)。
4)、第二设备
第二设备为SMF设备在删除UE会话上下文中保存的第一设备与SMF设备之间的第二接口信息之后，重新确定的用于为UE服务的设备。
当图2中的AMF设备实现为图3时，第二设备为AMF设备中的一个处理单元。
当图2中的AMF设备实现为图4所示的AMF群组时，第二设备为AMF群组中的一个AMF实例。
如图6所示，为了解决现有技术中负载不均衡的问题，本申请的实施例提供了一种消息传输的方法，当该方法应用于图4所示的场景中时，以UE、RAN设备、AMF实例1、AMF实例2、以及SMF设备之间的交互流程为例进行说明，其中，AMF实例1和AMF实例2属于同一个AMF群组，该方法包括三个阶段，第一阶段为会话建立过程，对应步骤601至步骤603；第二阶段为UE进入空闲状态的处理过程，对应步骤604至步骤607；第三阶段为SMF设备需要发送下行消息时，UE重新进入连接状态的过程，对应步骤608至步骤611。该方法具体包括：
601、UE向AMF实例1发送会话建立请求，AMF实例1接收会话建立请求。
其中，UE向AMF实例1发送会话建立请求是为了触发用户数据报协议(User Datagram Protocol，PDU)会话建立的过程，当UE发起PDU会话建立的过程时，UE处于连接状态，此时为UE服务的是AMF实例1。
602、AMF实例1向SMF设备发送会话建立请求，SMF设备接收会话建立请求。
其中，会话建立请求可以有以下三种实现方式。
第一种：会话建立请求中包括AMF实例1的第二接口信息(N11接口信息)。
第二种：会话建立请求中包括AMF实例1的第二接口信息(N11接口信息)、AMF实例1所属的AMF群组的指示信息。
第三种：会话建立请求中包括AMF实例1的第二接口信息(N11接口信息)、删除指示、AMF实例1所属的AMF群组的指示信息。
需要说明的是，AMF群组的指示信息可以为AMF群组ID，也可以为AMF群组的缺省路由。在图6对应的实施例中以AMF群组的指示信息为AMF群组ID为例进行说明。
还需说明的是，若采用上述第三种实现方式，AMF实例1需先判断自身所属的AMF群组是否支持无状态，若AMF群组支持无状态，AMF实例1才会将删除指示携带在会话建立请求中。其中，结合图4，AMF群组支持无状态是指，AMF实例不保存UE会话上下文信息，AMF群组中的各AMF实例服务的UE的会话上下文信息均被保存在AMF群组的DB中，同一AMF群组中的各个AMF实例可以共享DB中存储的UE会话上下文信息，这样每个AMF实例不仅可以处理自身服务过的UE的相关信息，也可以处理其他UE的相关信息。
其中，删除指示用于指示SMF设备在接收到第一接口释放消息时，删除SMF设备存储的UE会话上下文中的第二接口信息。
603、SMF设备将会话建立请求中携带的信息保存在UE会话上下文中。
可以理解的是，在上述步骤602描述的会话建立请求的每种实现方式中，会话建立请求中都会携带AMF实例1的第二接口信息，因为当前为UE服务的AMF实例为AMF实例1，所以SMF设备需将AMF实例1的第二接口信息保存在UE会话上下文中，以便于在UE处于连接状态时，SMF设备可以直接通过UE会话上下文中保存的第二接口信息，向为UE服务的 AMF实例1发送下行消息。
另外，如果会话建立请求中还包括AMF群组的指示信息，则SMF设备还需将AMF群组的指示信息保存在UE会话上下文中，同样，如果会话建立请求中还包括删除指示，则SMF设备还需将删除指示保存在UE会话上下文中。
需要说明的是UE会话上下文可以保存在SMF设备中，也可以保存在其他具有存储功能的设备中。
上述步骤601至步骤603为会话建立过程，在完成会话建立之后，当UE进入空闲状态时，还需执行UE进入空闲状态的处理过程。
604、RAN设备向AMF实例1发送第一接口释放请求消息，AMF实例1接收第一接口释放请求消息。
605、AMF实例1设备根据第一接口释放请求消息释放第一接口。
可以理解的是，AMF实例1释放AMF实例1与RAN之间的第一接口后，UE由连接状态切换为空闲状态。
606、AMF实例1向SMF设备发送第一接口释放消息，SMF设备接收第一接口释放消息。
需要说明的是，对应于步骤602，第一接口释放消息也包含三种实现方式。
第一种：若会话建立请求为步骤602中描述的第一种实现方式，则第一接口释放消息中可以携带删除指示、AMF实例1所属的AMF群组的指示信息、第一接口释放通知。
第二种：若会话建立请求为步骤602中描述的第二种实现方式，则第一接口释放消息中可以携带删除指示、第一接口释放通知。
第三种：若会话建立请求为步骤602中描述的第三种实现方式，则第一接口释放消息中可以携带第一接口释放通知。
需要说明的是，若AMF实例1要在第一接口释放消息中携带删除指示，需先判断自身所属的AMF群组是否支持无状态，若AMF群组支持无状态，AMF实例1才会将删除指示携带在第一接口释放消息中。
607、SMF设备在接收到第一接口释放消息的情况下，根据删除指示删除UE会话上下文中的第二接口信息。
其中，若第一接口释放消息中携带删除指示，则SMF设备直接根据第一接口释放消息中携带的删除指示删除UE会话上下文中的第二接口信息。若第一接口释放消息中未携带删除指示，且UE会话上下文中保存了删除指示，则SMF设备根据UE会话上下文中保存的删除指示删除第二接口信息。
SMF设备接收到第一接口释放消息，说明UE已经进入空闲状态，此时SMF设备删除UE会话上下文中的第二接口信息，可以避免在该UE重新进入链接状态时，SMF设备仍根据UE会话上下文中的第二接口信息将AMF实例1作为为UE服务的AMF实例。此时由于UE会话上下文中不存在第二接口信息，就只能在AMF群组中重新选取为UE服务的AMF实例，避免了一直由同一个AMF实例为UE服务。
上述步骤604至步骤607为UE进入空闲状态的处理过程，如果后续SMF设备接收到针对该UE的下行消息，则还需执行以下步骤608至步骤611，使UE重新进入连接状态。
608、当SMF设备需要发送下行消息时，SMF设备根据AMF群组ID，从AMF群组中选 择为UE服务的AMF实例，例如为AMF实例2。
其中，SMF设备可以根据AMF群组ID从网络存储功能(Network Function Repository Function，NRF)设备或者其他设备中查找为UE服务的AMF实例。SMF设备根据AMF群组ID选择为UE服务的AMF实例的具体方法与现有技术相同，此处不再赘述。
在一种可能的实现方式中，SMF设备可以在重新选择为UE服务的AMF实例2后，在UE会话上下文中保存SMF设备与AMF实例2之间的接口信息，以便于在该UE一直处于连接状态的情况下，SMF设备直接与AMF实例2进行通信，无需重新选择AMF实例。或者，在另一种可能的实现方式中，SMF设备也可以通过后续步骤610至步骤611来保存SMF设备与AMF实例2之间的接口信息。
609、SMF设备通过SMF设备与AMF实例2之间的接口向AMF实例2发送下行消息，AMF实例2接收下行消息。
需要说明的是，SMF设备在将下行消息发送给根据AMF群组标识查找到的AMF实例2之后，AMF实例2也可以重新为UE选取一个AMF实例，例如AMF实例3，并向AMF实例3发送下行消息，或者将AMF实例3的标识发送给SMF设备，由SMF设备向AMF实例3发送下行消息。
其中，AMF实例2接收到下行消息之后的后续处理下行消息的流程与现有技术相同，此处不再赘述。
需要说明的是，在后续的流程中，在UE重新进入连接状态之后，还可以执行步骤610至611。
610、AMF实例2向SMF设备发送响应消息，响应消息中包括AMF实例2与SMF设备之间的接口信息，SMF设备接收响应消息。
611、SMF设备将AMF实例2与SMF设备之间的接口信息保存在UE会话上下文中。
本申请的实施例提供的消息传输的方法，相比于现有技术中SMF设备总是选择上次为UE服务的AMF实例为UE提供服务，本申请的实施例中，在RAN释放RAN与为UE服务的AMF实例之间的接口时，说明UE进入空闲状态，SMF设备会将UE上下文中的SMF设备与为UE服务的AMF实例之间的接口信息删除，进而当SMF设备需要发送针对该UE的下行消息时，就无法直接从UE上下文中查找上一次为该UE服务的AMF实例与SMF设备之间的接口信息，就不会继续选择上次为UE服务的AMF实例，而是去重新选择AMF实例，这样就避免了SMF设备总是选择上次为UE服务的AMF实例而导致的负载不均衡的现象出现。
在图6所示的实施例中，是以AMF群组的指示信息为AMF群组ID为例进行说明的，在本申请的实施例提供的另一种实现方式中，AMF群组的指示信息还可以为AMF群组的缺省路由，当AMF群组的指示信息为AMF群组的缺省路由时，如图7所示，该方法可以实现为以下步骤701至步骤712。
其中，步骤701至步骤707与上述步骤601至步骤607相同，步骤711至712与上述步骤610至步骤611相同，此处不再赘述。
708、当SMF设备接需要发送下行消息时，SMF设备向AMF群组的缺省路由对应的设备发送下行消息，AMF群组的缺省路由对应的设备接收下行消息。
其中，AMF群组的缺省路由指向ASF单元，其中，ASF单元是一个网络功能，具体可 以为AMF群组中的缺省AMF实例，或者也可以为一个专门的网络功能，例如可以为一个负载均衡器。
709、ASF单元选择为UE服务的AMF实例，例如为AMF实例2。
710、ASF单元向AMF实例2发送下行消息，AMF实例2接收下行消息。
或者，在另一种可能的实现方式中，步骤710还可以替换为ASF单元向SMF设备发送AMF实例2的标识，然后SMF设备根据AMF实例2的标识，向AMF实例2发送下行消息。
图6和图7对应的实施例为当本申请的消息传输的方法应用于图4所示的场景时的实现方式，在本申请的另一实施例中，本申请的消息传输的方法还可以应用于图3所示的场景中，以UE、RAN设备、处理单元1、处理单元2、以及SMF设备之间的交互流程为例进行说明，其中，处理单元1和处理单元2属于同一个AMF设备，如图8所示，该方法包括：
801、UE向处理单元1发送会话建立请求，处理单元1接收会话建立请求。
其中，UE向处理单元1发送会话建立请求是为了触发PDU会话建立的过程，当UE发起PDU会话建立的过程时，UE处于连接状态，此时为UE服务的是处理单元1。
802、处理单元1向SMF设备发送会话建立请求，SMF设备接收会话建立请求。
其中，会话建立请求可以有以下三种实现方式。
第一种：会话建立请求中包括处理单元1的第二接口信息(N11接口信息)。
第二种：会话建立请求中包括处理单元1的第二接口信息(N11接口信息)、处理单元1所属的AMF设备的指示信息。
第三种：会话建立请求中包括处理单元1的第二接口信息(N11接口信息)、删除指示、处理单元1所属的AMF设备的指示信息。
需要说明的是，AMF设备的指示信息可以为AMF设备ID，也可以为AMF设备的缺省路由，在图8对应的实施例中，以AMF设备的指示信息为AMF设备ID为例进行说明。
803、SMF设备将会话建立请求中携带的信息保存在UE会话上下文中。
可以理解的是，在上述步骤802描述的会话建立请求的每种实现方式中，会话建立请求中都会携带处理单元1的第二接口信息，因为当前为UE服务的处理单元为处理单元1，所以SMF设备需将处理单元1的第二接口信息保存在UE会话上下文中，以便于在UE处于连接状态时，SMF设备可以直接通过UE会话上下文中保存的第二接口信息，向为UE服务的处理单元1发送下行消息。
另外，如果会话建立请求中还包括AMF设备的指示信息，则SMF设备还需将AMF设备的指示信息保存在UE会话上下文中，同样，如果会话建立请求中还包括删除指示，则SMF设备还需将删除指示保存在UE会话上下文中。
上述步骤801至步骤803为会话建立过程，在完成会话建立之后，当UE进入空闲状态时，还需执行UE进入空闲状态的处理过程。
804、RAN设备向处理单元1发送第一接口释放消息，处理单元1接收第一接口释放消息。
805、处理单元1根据第一接口释放消息释放第一接口。
可以理解的是，处理单元1释放处理单元1与RAN之间的第一接口后，UE由连接状态切 换为空闲状态。
806、处理单元1向SMF设备发送第一接口释放消息，SMF设备接收第一接口释放消息。
需要说明的是，对应于步骤802，第一接口释放消息也包含三种实现方式。
第一种：若会话建立请求为步骤802中描述的第一种实现方式，则第一接口释放消息中可以携带删除指示、处理单元1所属的AMF群组的指示信息、第一接口释放通知。
第二种：若会话建立请求为步骤802中描述的第二种实现方式，则第一接口释放消息中可以携带删除指示、第一接口释放通知。
第三种：若会话建立请求为步骤802中描述的第三种实现方式，则第一接口释放消息中可以携带第一接口释放通知。
需要说明的是，若处理单元1要在第一接口释放消息中携带删除指示，需先判断自身所属的AMF设备的各处理单元是否支持无状态，若AMF设备的各处理单元支持无状态，处理单元1才会将删除指示携带在第一接口释放消息中，结合图3，AMF设备的各处理单元支持无状态是指，各个处理单元中不保存UE会话上下文信息，各处理单元服务的UE的会话上下文信息均保存在DB中，同一AMF设备中的处理单元可以共享DB中存储的UE会话上下文信息。
807、SMF设备在接收到第一接口释放消息的情况下，根据删除指示删除UE会话上下文中的第二接口信息。
其中，若第一接口释放消息中携带删除指示，则SMF设备直接根据第一接口释放消息中携带的删除指示删除UE会话上下文中的第二接口信息。若第一接口释放消息中未携带删除指示，且UE会话上下文中保存了删除指示，则SMF设备根据UE会话上下文中保存的删除指示删除第二接口信息。
SMF设备接收到第一接口释放消息，说明UE已经进入空闲状态，此时SMF设备删除UE会话上下文中的第二接口信息，可以避免在该UE重新进入链接状态时，SMF设备仍根据UE会话上下文中的第二接口信息将处理单元1作为为UE服务的处理单元。此时由于UE会话上下文中不存在第二接口信息，就只能在SMF设备中重新选取为UE服务的处理单元，避免了一直由同一个处理单元为UE服务。
上述步骤804至步骤807为UE进入空闲状态的处理过程，如果后续SMF设备接收到针对该UE的下行消息，则还需执行以下步骤808至步骤811，使UE重新进入连接状态。
808、当SMF设备需要发送下行消息时，SMF设备根据AMF设备ID选择AMF设备的ASF单元。
其中，SMF设备可以根据AMF设备ID从NRF设备或者其他的设备中查找AMF设备的对外接口，该接口可以为ASF单元的传输层信息。在本实施例中，ASF单元可以为AMF设备中的一个LB单元，也可以为AMF设备中的一个处理单元。
在ASF单元为AMF设备中的一个处理单元的情况下，SMF设备可以直接将下行消息发送给该处理单元，由该处理单元为UE提供服务，或者，该处理单元接收到SMF设备发送的下行消息后，也可以执行以下步骤810至步骤811，重新选择为UE服务的处理单元，并将下行消息发送至重新选取的处理单元。
809、SMF设备向ASF单元发送下行消息，ASF单元接收下行消息。
需要说明的是，当ASF单元为LB单元时，也可以执行步骤810至811。
810、ASF单元选择为UE服务的处理单元，例如为处理单元2。
811、ASF单元向处理单元2发送下行消息，处理单元2接收下行消息。
在另一种可能的实现方式中，ASF单元还可以向SMF设备发送处理单元2的标识，由SMF设备根据处理单元2的标识向处理单元2发送下行消息。
其中，处理单元2接收到下行消息之后的后续处理下行消息的流程与现有技术相同，此处不再赘述。
需要说明的是，在后续的流程中，在UE重新进入连接状态之后，还可以执行步骤812至813。
812、处理单元2向SMF设备发送响应消息，响应消息中包括处理单元2与SMF设备之间的接口信息，SMF设备接收响应消息。
813、SMF设备将处理单元2与SMF设备之间的接口信息保存在UE会话上下文中。
本申请的实施例提供的消息传输的方法，由于在RAN释放RAN与为UE服务的处理单元之间的接口后，SMF设备会将UE上下文中的SMF设备与为UE服务的处理单元之间的接口删除，进而当SMF设备需要发送下行消息时，就需要重新触发选择处理单元的过程，可以实现处理单元之间的负载均衡。
上述主要从SMF设备的角度对本发明实施例提供的方案进行了介绍。可以理解的是，SMF设备中包含了执行各个功能相应的硬件结构和/或软件模块。本领域技术人员应该很容易意识到，结合本文中所公开的实施例描述的各示例的单元及算法步骤，本申请能够以硬件或硬件和计算机软件的结合形式来实现。某个功能究竟以硬件还是计算机软件驱动硬件的方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本发明的范围。
本申请的实施例可以根据上述方法示例对SMF设备进行功能模块的划分，例如，可以对应各个功能划分各个功能模块，也可以将两个或两个以上的功能集成在一个处理模块中。上述集成的模块既可以采用硬件的形式实现，也可以采用软件功能模块的形式实现。需要说明的是，本申请的实施例中对模块的划分是示意性的，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式。
在采用对应各个功能划分各个功能模块的情况下，本申请的实施例提供一种消息传输的装置，该装置可以实现为上述实施例中的SMF设备。如图9所示，图9示出了上述实施例中所涉及的SMF设备的一种可能的结构示意图。该SMF设备包括：接收模块901，删除模块902，发送模块903。
其中，接收模块901，用于接收来自第一设备的删除指示和第一设备所属群组的指示信息，删除指示用于指示删除模块902在接收模块901接收到第一接口释放消息时，删除用户设备UE会话上下文中的第二接口信息。
删除模块902，用于在接收模块901接收到第一接口释放消息的情况下，根据删除指示删除UE会话上下文中的第二接口信息。
发送模块903，用于当需要发送下行消息时，向第二设备发送下行消息。
在本申请实施例的另一种可能的实现方式中，该装置还包括：存储模块904。
接收模块901，具体用于接收来自第一设备的会话建立请求，会话建立请求中包括群组的指示信息、删除指示以及第二接口信息。
存储模块904，用于将群组的指示信息、删除指示以及第二接口信息保存在UE会话上下文中。
删除模块902，具体用于在接收模块接收到第一设备发送的第一接口释放消息的情况下，根据UE会话上下文中的删除指示，删除UE会话上下文中的第二接口信息。
在本申请实施例的另一种可能的实现方式中，接收模块901，具体用于接收来自第一设备的会话建立请求，会话建立请求中包括群组的指示信息和第二接口信息；以及接收来自第一设备的第一接口释放消息，第一接口释放消息中包括删除指示。
存储模块904，用于将群组的指示信息和第二接口信息保存在UE会话上下文中。
在本申请实施例的另一种可能的实现方式中，接收模块901，具体用于接收来自所述第一设备的会话建立请求，会话建立请求中包括第二接口信息；以及接收来自第一设备的第一接口释放消息，第一接口释放消息中包括群组的指示信息和删除指示。
存储模块904，用于将第二接口信息保存在UE会话上下文中。
删除模块902，具体用于根据第一接口释放消息中包括的删除指示删除UE的会话上下文中的第二接口信息。
在本申请实施例的另一种可能的实现方式中，群组的指示信息为群组的群组身份标识ID；
对应的，发送模块903，具体用于根据所述群组ID确定为UE服务的第二设备；通过消息传输的装置与第二设备之间的接口向第二设备发送下行消息。
在本申请实施例的另一种可能的实现方式中，群组的指示信息为群组的缺省路由；
发送模块903，具体用于当向群组的缺省路由对应的设备发送下行消息；接收来自群组的缺省路由对应的设备的第二设备标识，第二设备为群组的缺省路由对应的设备为UE选择的第二设备；通过消息传输的装置与第二设备之间的接口，向接收模块接收到的第二设备标识对应的第二设备发送下行消息。
在本申请实施例的另一种可能的实现方式中，群组的指示信息为群组的缺省路由；
发送模块903，具体用于通过群组的缺省路由对应的设备向第二设备发送下行消息，第二设备为群组的缺省路由对应的设备为UE选择的第二设备。
另外，存储模块904，用于当接收模块901接收到来自第二设备的消息后，将消息传输的装置与第二设备之间的接口信息保存在UE会话上下文中。
具体的，对应上述方法实施例，接收模块901用于支持SMF设备接收图6中的步骤602发送的会话建立请求，步骤606发送的第一接口释放消息，步骤610发送的响应消息，以及图7中步骤702发送的第一接口释放消息，步骤706发送的第一接口释放消息，步骤711发送的响应消息，还用于支持SMF设备接收图8中步骤802发送的会话建立请求，步骤806发送的第一接口释放消息，以及步骤812发送的响应消息。删除模块903，用于支持SMF设备执行图6中的步骤607，图7中的步骤707，以及图8中的步骤807。发送模块903，用于支持SMF设备执行图6中的步骤609，图7中的步骤708，以及图8中的步骤809。存储模块904，用于支持SMF设备执行图6中的步骤603和步骤611，图7中的步骤703和步骤712，图8中的步骤803 和步骤813。
其中，上述方法实施例涉及的各步骤的所有相关内容均可援引到对应功能模块的功能描述，在此不再赘述。
在采用集成的单元的情况下，需要说明的是，图9所示的接收模块901和发送模块903，可以集成在图5所示的通信接口503中，使通信接口503执行接收模块901和发送模块903的具体功能。删除模块902可以集成在图5所示处理器502中，使处理器502执行删除模块902的具体功能。存储模块904，可以集成在图5所示的存储器501中，使存储器501执行存储模块904的具体功能。
如图10所示，为了解决现有技术中负载不均衡的问题，本申请的另一实施例提供一种数据传输的方法，当该方法应用于图4的场景中时，以UE、RAN设备、AMF实例以及SMF设备之间的交互流程为例进行说明，其中，AMF实例1和AMF实例2属于同一个AMF群组，该方法包括三个阶段，第一阶段为会话建立过程，对应步骤1001至步骤1003；第二阶段为UE进入空闲状态的处理过程，对应步骤1004至步骤1007；第三阶段为SMF设备需要发送下行消息时，UE重新进入连接状态的过程，对应步骤1008至步骤1009。该方法具体包括：
1001、UE向AMF实例1发送会话建立请求，AMF实例1接收会话建立请求。
其中，UE向AMF实例1发送会话建立请求是为了触发PDU会话建立的过程，当UE发起PDU会话建立的过程时，UE处于连接状态，此时为UE服务的是AMF实例1。
1002、AMF实例1向SMF设备发送会话建立请求，AMF实例1接收会话建立请求。
其中，会话建立请求可以有以下三种实现方式。
第一种：会话建立请求中包括AMF实例1的信息。
其中，AMF实例1的信息用于SMF设备寻址AMF实例，例如，AMF实例1的信息可以为AMF实例标识、AMF实例中业务端点的统一资源标识符(uniform resource identifier,URI)或者AMF实例在NRF设备中注册的资源标识等。
第二种：会话建立请求中包括AMF实例1的信息、AMF实例1所属的AMF群组的指示信息。
第三种：会话建立请求中包括AMF实例1信息、无状态指示信息、AMF实例1所属的AMF群组的指示信息。
需要说明的是，AMF群组的指示信息可以为AMF群组ID，也可以为AMF群组的缺省路由。在图9对应的实施例中以AMF群组的指示信息为AMF群组ID为例进行说明。
还需说明的是，若采用上述第三种实现方式，AMF实例1需先判断自身所属的AMF群组是否支持无状态模式，若AMF群组支持无状态模式，AMF实例1才会将无状态指示信息携带在会话建立请求中。其中，结合图4，AMF群组支持无状态模式是指，当UE处于空闲态时AMF实例不保存UE会话上下文信息，AMF群组中的各AMF实例服务的空闲态的UE的会话上下文信息均被保存在AMF群组的DB中，同一AMF群组中的各个AMF实例可以共享DB中存储的UE会话上下文信息，这样每个AMF实例不仅可以处理自身服务过的UE的相关信息，也可以处理其他UE的相关信息。
其中，无状态指示信息用于指示SMF设备在确定UE对应的信令连接与第一接口的绑定 释放后，若SMF设备需要给AMF实例发送下行消息，SMF设备需根据AMF群组的指示信息从AMF群组中重新选择AMF实例，并将下行消息发送给新选择的AMF实例。
无状态指示信息可以是一个单独的指示信息，例如，在消息中携带一个比特位来指示AMF群组工作在无状态模式，也可以是用其他方式来体现，比如，在消息中携带特殊的AMF指针来表示AMF群组工作在无状态模式(例如，若消息中携带的AMF指针标识为1111则表示该AMF群组工作在无状态模式)。
信令连接与第一接口的绑定释放包括但不限于以下两种情况：
第一种：UE对应的信令连接释放，且信令连接与第一接口的绑定也释放。
第二种：信令连接与第一接口的绑定释放，UE对应的信令连接不释放。
在具体实现中，信令连接中的信令可以指下一代应用协议(Next Generation application protocol，NGAP)信令，也可以指N2接口的应用协议(N2reference application protocol，N2AP)。
需要说明的是，除了上述获取无状态指示信息的方法之外，SMF还可根据AMF群组的指示信息从本地配置信息中获取上述无状态指示信息。
1003、SMF设备将会话建立请求中携带的信息保存在UE会话上下文中。
可以理解的是，在上述步骤1002描述的会话建立请求的每种实现方式中，会话建立请求中都会携带AMF实例1的信息，因为当前为UE服务的AMF实例为AMF实例1，所以SMF设备需将AMF实例1的信息保存在UE会话上下文中，以便于在UE处于连接状态时，SMF设备可以直接通过UE会话上下文中保存的AMF实例1的信息，向为UE服务的AMF实例1发送下行消息。
另外，如果会话建立请求中还包括AMF群组的指示信息，则SMF设备还需将AMF群组的指示信息保存在UE会话上下文中。可选地，如果会话建立请求中还包括无状态指示信息，则SMF设备还需将无状态指示信息保存在UE会话上下文中，或者可选地，SMF设备可将无状态指示信息保存在AMF群组或AMF对应的上下文中。
需要说明的是UE会话上下文可以保存在SMF设备中，也可以保存在其他具有存储功能的设备中。
上述步骤1001至步骤1003为会话建立过程，在完成会话建立之后，当UE进入空闲状态时，还需执行UE进入空闲状态的处理过程。
1004、RAN设备向AMF实例1发送释放消息，AMF实例1接收释放消息。
其中，释放消息用于指示AMF实例1释放UE对应的信令连接与第一接口的绑定。
1005、AMF实例1设备根据释放消息释放UE对应的信令连接与第一接口的绑定。
可以理解的是，AMF实例1释放AMF实例1与RAN之间的UE对应的信令连接与第一接口的绑定后，UE由连接状态切换为空闲状态。
1006、AMF实例1向SMF设备发送会话更新请求或释放通知，该会话更新请求中包括释放原因，SMF设备接收会话更新请求或者释放通知。
其中，释放原因用于表示UE对应的信令连接与第一接口的绑定释放的原因。释放通知用于表示UE对应的信令连接与第一接口的绑定已释放。
需要说明的是，对应于步骤1002，会话更新请求消息也包含三种实现方式。
第一种：若会话建立请求为步骤1002中描述的第一种实现方式，则会话更新请求中可以携带AMF实例1所属的AMF群组的指示信息和释放原因。可选的会话更新请求中还可以携带无状态指示信息。
第二种：若会话建立请求为步骤1002中描述的第二种实现方式，则会话更新请求中可以携带释放原因。可选的会话更新请求中还可以携带无状态指示信息。
第三种：若会话建立请求为步骤1002中描述的第三种实现方式，则会话更新请求消息中可以携带释放原因。
需要说明的是，若AMF实例1要在会话更新请求消息中携带无状态指示信息，需先判断自身所属的AMF群组是否支持无状态模式，若AMF群组支持无状态模式，AMF实例1才会将无状态指示信息携带在会话更新请求中。
类似地，释放通知也包括以上三种实现方式。
需要说明的是，这一步，除了AMF实例1向SMF设备发送会话更新请求或者释放通知，并且在会话更新请求或携带释放原因，AMF实例1也可能向SMF设备发送UE进入空闲态的通知。类似地，进入空闲态通知也包括上述三种实现方式。
1007、SMF设备根据释放原因、释放通知或者UE进入空闲态通知判断UE对应的信令连接与第一接口的绑定释放。
在一种实现方式中，SMF设备根据无状态指示信息删除UE会话上下文中的AMF实例1的信息。
其中，若会话更新请求消息中携带无状态指示信息，则SMF设备直接根据会话更新请求中携带的无状态指示信息删除UE会话上下文中的AMF实例1的信息。若会话更新请求消息中未携带无状态指示信息，且UE会话上下文中保存了无状态指示信息，则SMF设备根据UE会话上下文中保存的无状态指示信息删除AMF实例1的信息。除此之外，SMF设备还可根据配置AMF群组的信息从本地配置信息中获取无状态指示信息，并根据本地配置信息中的无状态指示信息删除AMF实力1的信息。
SMF设备根据接收到会话更新请求或释放通知或者根据接收到的UE进入空闲态通知，判断UE已经进入空闲状态，此时SMF设备删除UE会话上下文中的AMF实例1的信息，可以避免在该UE重新进入连接状态时，SMF设备仍根据UE会话上下文中的AMF实例1的信息将AMF实例1作为为UE服务的AMF实例。此时由于UE会话上下文中不存在AMF实例1的信息，就只能在AMF群组中重新选取为UE服务的AMF实例，避免了一直由同一个AMF实例为UE服务。
在另外一种实现方式中，SMF设备在步骤1007中不删除AMF实例1的的信息，SMF设备根据接收到会话更新请求或释放通知或者根据接收到的UE进入空闲态通知，判断UE已经进入空闲状态，SMF设备将UE的连接管理(Connection Management，CM)状态设置为空闲态。
上述步骤1004至步骤1007为UE进入空闲状态的处理过程，如果后续SMF设备接收到针对该UE的下行消息，则还需执行以下步骤1008至步骤1009，使UE重新进入连接状态。
1008、当SMF设备需要发送下行消息时，SMF设备根据AMF群组ID，从AMF群组中选择为UE服务的AMF实例，例如为AMF实例2。
可选地，当SMF设备需要发送下行消息时，可判断UE对应的信令连接与第一接口的绑定是否释放，若确定UE对应的信令连接与第一接口的绑定已释放，则根据AMF群组ID，从AMF群组中选择为UE服务的AMF实例。
在一种实现方式中，SMF设备查询UE会话上下文，若UE会话上下文中没有保存任何AMF实例的信息，则SMF设备根据AMF群组ID选择为UE服务的AMF实例。
在另一种实现方式中，SMF设备判断UE的CM状态为空闲态，并且，SMF设备收到了来自AMF实例1的无状态指示信息(如步骤1001或者1006)或者SMF设备根据配置确定AMF群组工作在无状态模式，则，即使UE会话上下文中保存了AMF实例信息，SMF设备还是根据AMF群组ID选择为UE服务的AMF实例。
其中，SMF设备可以根据AMF群组ID从网络存储功能(Network Function Repository Function，NRF)设备或者其他设备中查找为UE服务的AMF实例。SMF设备根据AMF群组ID选择为UE服务的AMF实例的具体方法与现有技术相同，此处不再赘述。
SMF设备可以在重新选择为UE服务的AMF实例2后，在UE会话上下文中保存AMF实例2的信息，以便于在该UE一直处于连接状态的情况下，SMF设备直接与AMF实例2进行通信，无需重新选择AMF实例。
1009、SMF设备向AMF实例2发送下行消息，AMF实例2接收下行消息。
需要说明的是，SMF设备在将下行消息发送给根据AMF群组标识查找到的AMF实例2之后，AMF实例2也可以重新为UE选取一个AMF实例，例如AMF实例3，并向AMF实例3发送下行消息，或者将AMF实例3的标识发送给SMF设备，由SMF设备向AMF实例3发送下行消息。
其中，AMF实例2接收到下行消息之后的后续处理下行消息的流程与现有技术相同，此处不再赘述。
本申请的实施例提供的消息传输的方法，相比于现有技术中SMF设备总是选择上次为UE服务的AMF实例为UE提供服务，本申请的实施例中，在RAN释放RAN与为UE服务的AMF实例之间的接口与UE对应的信令的绑定时，说明UE进入空闲状态，SMF设备会将UE上下文中的AMF实例的信息删除，进而当SMF设备需要发送针对该UE的下行消息时，就无法直接从UE上下文中查找上一次为该UE服务的AMF实例的信息，就不会继续选择上次为UE服务的AMF实例，而是去重新选择AMF实例，这样就避免了SMF设备总是选择上次为UE服务的AMF实例而导致的负载不均衡的现象出现。
在采用对应各个功能划分各个功能模块的情况下，本申请的实施例提供一种消息传输的装置，该装置可以实现为上述实施例中的SMF设备。如图11所示，图11示出了上述实施例中所涉及的SMF设备的另一种可能的结构示意图。该SMF设备包括：获取模块1101和发送模块1102。
获取模块1101，用于获取无状态指示信息和第一设备所属群组的群组指示信息，无状态指示信息用于指示在确定用户设备UE对应的信令连接与第一接口的绑定释放后需要发送下行消息时，根据群组指示信息选择用于为UE服务的第二设备，第一设备为信令连接与第一接口的绑定释放前为UE服务的设备，第一接口为无线接入网RAN与第一设备间的接口。
发送模块1102，用于在获取模块1101接收到来自第一设备的释放通知的情况下，当需要发送下行消息时，向第二设备发送下行消息，第二设备为根据群组指示信息确定的用于为UE服务的设备。其中，释放通知用于表示UE对应的信令连接与第一接口的绑定已释放。
在本申请实施例的另一种可能的实现方式中，该装置还包括确定模块1103。
确定模块1103，用于确定UE对应的信令连接与第一接口的绑定释放。
在本申请实施例的另一种可能的实现方式中，确定模块1103，还用于若发送模块需要发送下行消息，且确定模块1103确定UE对应的信令连接与第一接口的绑定释放，则根据群组指示信息确定用于为UE服务的第二设备。
在本申请实施例的另一种可能的实现方式中，获取模块1101，具体用于接收来自第一设备的会话建立请求，会话建立请求中包括所述群组指示信息；或者，接收来自第一设备的释放通知，释放通知中包括群组指示信息。
在本申请实施例的另一种可能的实现方式中，获取模块1101，具体用于接收来自第一设备的会话建立请求，会话建立请求中包括无状态指示信息；或者，接收来自第一设备的释放通知，释放通知种包括无状态指示信息；或者，从本地配置信息中获取无状态指示信息。
在本申请实施例的另一种可能的实现方式中，该装置还包括删除模块1104。
删除模块1104，用于在获取模块1101接收到来自第一设备的释放通知后，根据无状态指示信息删除UE会话上下文中的第一设备的信息。
在本申请实施例的另一种可能的实现方式中，该装置还包括：存储模块1105。
存储模块1105，用于在获取模块1101接收到来自第一设备的释放通知后，保存信令连接与第一接口的绑定的释放状态。
可选地，确定模块1103，还用于根据信令连接与第一接口的绑定的释放状态确定信令连接与第一接口的绑定已释放；
进一步地，确定模块1103，还用于若发送模块1102需要发送下行消息，且确定模块1103根据信令连接与第一接口的绑定的释放状态确定信令连接与第一接口的绑定已释放，则根据群组指示信息确定用于为UE服务的第二设备。
其中，群组指示信息为第一设备所属群组的群组身份标识ID；
确定模块1103，具体用于若发送模块1102需要发送下行消息，且确定模块1103根据信令连接与第一接口的绑定的释放状态确定信令连接与第一接口的绑定已释放，则根据群组ID确定为UE服务的第二设备。
具体的，对应上述方法实施例，获取模块1101用于支持SMF设备获取图10中的步骤1002发送的会话建立请求，步骤1006发送的第一接口释放消息。发送模块1102，用于支持SMF设备执行图10中的步骤1009。删除模块1104，用于支持SMF设备执行图10中的步骤1007。确定模块1103，用于支持SMF设备执行图10中的步骤1008。存储模块1105，用于支持SMF设备执行图10中的步骤1003。
其中，上述方法实施例涉及的各步骤的所有相关内容均可援引到对应功能模块的功能描述，在此不再赘述。
在采用集成的单元的情况下，需要说明的是，图11所示的获取模块1101和发送模块1102， 可以集成在图5所示的通信接口503中，使通信接口503执行获取模块1101和发送模块1102的具体功能。确定模块1103和删除模块1104可以集成在图5所示处理器502中，使处理器502执行确定模块1103和删除模块1104的具体功能。存储模块1105，可以集成在图5所示的存储器501中，使存储器501执行存储模块1105的具体功能。
本申请的实施例还提供了一种计算机存储介质，用于存储为上述SMF设备所用的计算机软件指令，器包含用于执行上述实施例中SMF设备执行的步骤所设计的程序。
本申请的实施例还提供了一种计算机程序产品，例如计算机可读存储介质，包括用于执行上述实施例中SMF设备执行的步骤所设计的程序。
结合本申请公开内容所描述的方法或者算法的步骤可以硬件的方式来实现，也可以是由处理器执行软件指令的方式来实现。软件指令可以由相应的软件模块组成，软件模块可以被存放于随机存取存储器(Random Access Memory，RAM)、闪存、只读存储器(Read Only Memory，ROM)、可擦除可编程只读存储器(Erasable Programmable ROM，EPROM)、电可擦可编程只读存储器(Electrically EPROM，EEPROM)、寄存器、硬盘、移动硬盘、只读光盘(CD-ROM)或者本领域熟知的任何其它形式的存储介质中。一种示例性的存储介质耦合至处理器，从而使处理器能够从该存储介质读取信息，且可向该存储介质写入信息。当然，存储介质也可以是处理器的组成部分。处理器和存储介质可以位于ASIC中。另外，该ASIC可以位于核心网接口设备中。当然，处理器和存储介质也可以作为分立组件存在于核心网接口设备中。
在本申请所提供的几个实施例中，应该理解到，所揭露的系统，装置和方法，可以通过其它的方式实现。例如，以上所描述的装置实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个系统，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口，装置或单元的间接耦合或通信连接，可以是电性或其它的形式。
所述作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的部件可以是或者也可以不是物理单元，即可以位于一个地方，或者也可以分布到多个网络设备上。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。
另外，在本发明各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个功能单元独立存在，也可以两个或两个以上单元集成在一个单元中。上述集成的单元既可以采用硬件的形式实现，也可以采用硬件加软件功能单元的形式实现。
通过以上的实施方式的描述，所属领域的技术人员可以清楚地了解到本申请可借助软件加必需的通用硬件的方式来实现，当然也可以通过硬件，但很多情况下前者是更佳的实施方式。基于这样的理解，本申请的技术方案本质上或者说对现有技术做出贡献的部分可以以软件产品的形式体现出来，该计算机软件产品存储在可读取的存储介质中，如计算机的软盘，硬盘或光盘等，包括若干指令用以使得一台计算机设备(可以是个人计算机，服务器，或者网络设备等)执行本申请各个实施例所述的方法。
以上所述，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，在本申请揭露的技术范围内的变化或替换，都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应以所述权利要求的保护范围为准。

Claims (32)

  1. 一种消息传输的方法，其特征在于，包括：
    会话管理功能设备接收来自第一设备的删除指示和所述第一设备所属的群组的指示信息，所述删除指示用于指示所述会话管理功能设备在收到第一接口释放消息时，删除用户设备UE会话上下文中的第二接口信息，所述第一接口为无线接入网RAN与所述第一设备间的接口，所述第二接口为所述第一设备与所述会话管理功能设备间的接口；
    在所述会话管理功能设备接收到来自所述第一设备的第一接口释放消息的情况下，所述会话管理功能设备根据所述删除指示删除所述UE会话上下文中的第二接口信息；
    当所述会话管理功能设备需要发送下行消息时，所述会话管理功能设备向第二设备发送所述下行消息，所述第二设备为根据所述群组的指示信息确定的用于为所述UE服务的设备。
  2. 根据权利要求1所述的方法，其特征在于，所述会话管理功能设备接收来自第一设备的删除指示和所述第一设备所属的群组的指示信息，包括：
    所述会话管理功能设备接收来自所述第一设备的会话建立请求，所述会话建立请求中包括所述群组的指示信息、所述删除指示以及所述第二接口信息；
    在所述会话管理功能设备接收来自所述第一设备的会话建立请求之后，所述方法还包括：
    所述会话管理功能设备将所述群组的指示信息，所述删除指示以及所述第二接口信息保存在所述UE会话上下文中。
  3. 根据权利要求2所述的方法，其特征在于，所述会话管理功能设备根据所述删除指示删除所述UE会话上下文中的第二接口信息，包括：
    所述会话管理功能设备根据所述UE会话上下文中的所述删除指示，删除所述UE会话上下文中的第二接口信息。
  4. 根据权利要求1所述的方法，其特征在于，所述会话管理功能设备接收来自第一设备的删除指示和所述第一设备所属的群组的指示信息，包括：
    所述会话管理功能设备接收来自所述第一设备的会话建立请求，所述会话建立请求中包括所述群组的指示信息和所述第二接口信息；
    所述会话管理功能设备接收来自所述第一设备的第一接口释放消息，所述第一接口释放消息中包括所述删除指示；
    在所述会话管理功能设备接收来自所述第一设备的会话建立请求之后，所述方法还包括：
    所述会话管理功能设备将所述群组的指示信息和所述第二接口信息保存在所述UE会话上下文中。
  5. 根据权利要求1所述的方法，其特征在于，所述会话管理功能设备接收来自第一设备的删除指示和所述第一设备所属的群组的指示信息，包括：
    所述会话管理功能设备接收来自所述第一设备的第一接口释放消息，所述第一接口释放消息中包括所述群组的指示信息和所述删除指示；
    在所述会话管理功能设备接收来自所述第一设备的第一接口释放消息之前，所述方法还包括：
    所述会话管理功能设备接收来自所述第一设备的会话建立请求，所述会话建立请求中包括所述第二接口信息；
    所述会话管理功能设备将所述第二接口信息保存在所述UE会话上下文中。
  6. 根据权利要求4或5所述的方法，其特征在于，所述会话管理功能设备根据所述删除指示删除所述UE会话上下文中的第二接口信息，包括：
    所述会话管理功能设备根据所述第一接口释放消息中包括的所述删除指示删除所述UE的会话上下文中的第二接口信息。
  7. 根据权利要求1所述的方法，其特征在于，所述群组的指示信息为所述群组的群组身份标识ID；相应的，所述会话管理功能设备向第二设备发送所述下行消息，包括：
    所述会话管理功能设备根据所述群组ID确定为所述UE服务的第二设备；
    所述会话管理功能设备通过所述会话管理功能设备与所述第二设备之间的接口向所述第二设备发送所述下行消息。
  8. 根据权利要求1所述的方法，其特征在于，所述群组的指示信息为所述群组的缺省路由；相应的，所述会话管理功能设备向第二设备发送所述下行消息，包括：
    当所述会话管理功能设备需要发送下行消息时，所述会话管理功能设备向所述群组的缺省路由对应的设备发送所述下行消息；
    所述会话管理功能设备接收来自所述群组的缺省路由对应的设备的第二设备标识，所述第二设备为所述群组的缺省路由对应的设备为所述UE选择的第二设备；
    所述会话管理功能设备通过所述会话管理功能设备与所述第二设备之间的接口，向所述第二设备标识对应的第二设备发送所述下行消息。
  9. 根据权利要求1所述的方法，其特征在于，所述群组的指示信息为所述群组的缺省路由；相应的，所述会话管理功能设备向第二设备发送所述下行消息，包括：
    当所述会话管理功能设备需要发送下行消息时，所述会话管理功能设备通过所述群组的缺省路由对应的设备向所述第二设备发送所述下行消息，所述第二设备为所述群组的缺省路由对应的设备为所述UE选择的第二设备。
  10. 根据权利要求7至9中任一项所述的方法，其特征在于，在所述会话管理功能设备通过所述群组的缺省路由对应的设备向所述第二设备发送所述下行消息之后，所述方法还包括：
    当所述会话管理功能设备接收到来自所述第二设备的消息后，所述会话管理功能设备将所述会话管理功能设备与所述第二设备之间的接口信息保存在所述UE会话上下文中。
  11. 一种消息传输的装置，其特征在于，包括：
    接收模块，用于接收来自第一设备的删除指示和所述第一设备所属的群组的指示信息，所述删除指示用于指示删除模块在所述接收模块接收到第一接口释放消息时，删除用户设备UE会话上下文中的第二接口信息，所述第一接口为无线接入网RAN与所述第一设备间的接口，所述第二接口为所述第一设备与所述消息传输的装置间的接口；
    所述删除模块，用于在所述接收模块接收到来自所述第一设备的第一接口释放消息的情况下，根据所述删除指示删除所述UE会话上下文中的第二接口信息；
    发送模块，用于当需要发送下行消息时，向第二设备发送所述下行消息，所述第二设备为根据所述群组的指示信息确定的用于为所述UE服务的设备。
  12. 根据权利要求11所述的装置，其特征在于，所述装置还包括：存储模块；
    所述接收模块，具体用于接收来自所述第一设备的会话建立请求，所述会话建立请求中包括所述群组的指示信息、所述删除指示以及所述第二接口信息；
    所述存储模块，用于将所述群组的指示信息，所述删除指示以及所述第二接口信息保存在所述UE会话上下文中。
  13. 根据权利要求12所述的装置，其特征在于，
    所述删除模块，具体用于在所述接收模块接收到所述第一设备发送的第一接口释放消息的情况下，根据所述UE会话上下文中的所述删除指示，删除所述UE会话上下文中的第二接口信息。
  14. 根据权利要求11所述的装置，其特征在于，所述装置还包括：存储模块；
    所述接收模块，具体用于接收来自所述第一设备的会话建立请求，所述会话建立请求中包括所述群组的指示信息和所述第二接口信息；以及接收来自所述第一设备的第一接口释放消息，所述第一接口释放消息中包括所述删除指示；
    所述存储模块，用于将所述群组的指示信息和所述第二接口信息保存在所述UE会话上下文中。
  15. 根据权利要求11所述的装置，其特征在于，所述装置还包括：存储模块；
    所述接收模块，具体用于接收来自所述第一设备的第一接口释放消息，所述第一接口释放消息中包括所述群组的指示信息和所述删除指示；以及接收来自所述第一设备的会话建立请求，所述会话建立请求中包括所述第二接口信息；
    所述存储模块，用于将所述第二接口信息保存在所述UE会话上下文中。
  16. 根据权利要求14或15所述的装置，其特征在于，
    所述删除模块，具体用于根据所述第一接口释放消息中包括的所述删除指示删除所述UE的会话上下文中的第二接口信息。
  17. 根据权利要求11所述的装置，其特征在于，所述群组的指示信息为所述群组的群组身份标识ID；
    所述发送模块，具体用于根据所述群组ID确定为所述UE服务的第二设备；通过所述消息传输的装置与所述第二设备之间的接口向所述第二设备发送所述下行消息。
  18. 根据权利要求11所述的装置，其特征在于，所述群组的指示信息为所述群组的缺省路由；
    所述发送模块，具体用于向所述群组的缺省路由对应的设备发送所述下行消息；接收来自所述群组的缺省路由对应的设备的第二设备标识，所述第二设备为所述群组的缺省路由对应的设备为所述UE选择的第二设备；通过所述消息传输的装置与所述第二设备之间的接口，向所述接收模块接收到的第二设备标识对应的第二设备发送所述下行消息。
  19. 根据权利要求11所述的装置，其特征在于，所述群组的指示信息为所述群组的缺省路由；
    所述发送模块，具体用于通过所述群组的缺省路由对应的设备向所述第二设备发送所述下行消息，所述第二设备为所述群组的缺省路由对应的设备为所述UE选择的第二设备。
  20. 根据权利要求17至19中任一项所述的装置，其特征在于，所述装置还包括：存储模块；
    所述存储模块，用于当所述接收模块接收到来自所述第二设备的消息后，将所述消息传输的装置与所述第二设备之间的接口信息保存在所述UE会话上下文中。
  21. 一种消息传输的方法，其特征在于，包括：
    会话管理功能设备获取无状态指示信息和第一设备所属群组的群组指示信息，所述无状态指示信息用于指示所述会话管理功能设备在确定用户设备UE对应的信令连接与第一接口的绑定释放后需要发送下行消息时，根据所述群组指示信息选择用于为所述UE服务的第二设 备，所述第一设备为所述信令连接与所述第一接口的绑定释放前为所述UE服务的设备，所述第一接口为无线接入网RAN与所述第一设备间的接口；
    在所述会话管理功能设备接收到来自所述第一设备的释放通知的情况下，当所述会话管理功能设备需要发送下行消息时，所述会话管理功能设备向第二设备发送所述下行消息，所述第二设备为根据所述群组指示信息确定的用于为所述UE服务的设备。
  22. 根据权利要求21所述的方法，其特征在于，所述方法还包括：
    所述会话管理功能设备确定所述UE对应的信令连接与第一接口的绑定释放。
  23. 根据权利要求21或22所述的方法，其特征在于，所述会话管理功能设备获取第一设备所属群组的群组指示信息，包括：
    所述会话管理功能设备接收来自所述第一设备的会话建立请求，所述会话建立请求中包括所述群组指示信息；或者，
    所述会话管理功能设备接收来自所述第一设备的所述释放通知，所述释放通知中包括所述群组指示信息。
  24. 根据权利要求21或22所述的方法，其特征在于，所述会话管理功能设备获取无状态指示信息，包括：
    所述会话管理功能设备接收来自所述第一设备的会话建立请求，所述会话建立请求中包括所述无状态指示信息；或者，
    所述会话管理功能设备接收来自所述第一设备的所述释放通知，所述释放通知中包括所述无状态指示信息；或者，
    所述会话管理功能设备从本地配置信息中获取所述无状态指示信息。
  25. 根据权利要求21或22所述的方法，其特征在于，所述群组指示信息为所述第一设备所属群组的群组身份标识ID；相应的，所述方法还包括：
    若所述会话管理功能设备需要发送下行消息，且所述会话管理功能设备确定UE对应的信令连接与第一接口的绑定释放，则所述会话管理功能设备根据所述群组ID确定为所述UE服务的第二设备。
  26. 一种消息传输的装置，其特征在于，包括：获取模块和发送模块；
    所述获取模块，用于获取无状态指示信息和第一设备所属群组的群组指示信息，所述无状态指示信息用于指示在确定用户设备UE对应的信令连接与第一接口的绑定释放后需要发送下行消息时，根据所述群组指示信息选择用于为所述UE服务的第二设备，所述第一设备为所述信令连接与所述第一接口的绑定释放前为所述UE服务的设备，所述第一接口为无线接入网RAN与所述第一设备间的接口；
    所述发送模块，用于在所述获取模块接收到来自所述第一设备的释放通知的情况下，当需要发送下行消息时，向第二设备发送所述下行消息，所述第二设备为根据所述群组指示信息确定的用于为所述UE服务的设备。
  27. 根据权利要求26所述的装置，其特征在于，所述装置还包括：确定模块；
    所述确定模块，用于确定UE对应的信令连接与第一接口的绑定释放。
  28. 根据权利要求26或27所述的装置，其特征在于，
    所述获取模块，具体用于接收来自所述第一设备的会话建立请求，所述会话建立请求中包括所述群组指示信息；或者，接收来自所述第一设备所述释放通知，所述释放通知中包括所述群组指示信息。
  29. 根据权利要求26或27所述的装置，其特征在于，
    所述获取模块，具体用于接收来自所述第一设备的会话建立请求，所述会话建立请求中包括所述无状态指示信息；或者，接收来自所述第一设备的所述释放通知，所述释放通知中包括所述无状态指示信息；或者，从本地配置信息中获取所述无状态指示信息。
  30. 根据权利要求26或27所述的装置，其特征在于，所述群组指示信息为所述第一设备所属群组的群组身份标识ID；
    所述确定模块，具体用于若所述发送模块需要发送下行消息，且所述确定模块确定UE对应的信令连接与第一接口的绑定已释放，则根据所述群组ID确定为所述UE服务的第二设备。
  31. 一种会话管理功能设备，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如权利要求1-10中任一一项所述的方法。
  32. 一种会话管理功能设备，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如权利要求21-25中任一一项所述的方法。
PCT/CN2018/084729 2017-05-03 2018-04-27 一种消息传输的方法及装置 Ceased WO2018201973A1 (zh)

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CN103428787A (zh) * 2012-05-17 2013-12-04 大唐移动通信设备有限公司 一种基站切换方法及装置
CN105813079A (zh) * 2016-05-17 2016-07-27 工业和信息化部电信研究院 一种终端接入方法
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CN102378295A (zh) * 2010-08-23 2012-03-14 中兴通讯股份有限公司 承载释放方法及系统
CN103428787A (zh) * 2012-05-17 2013-12-04 大唐移动通信设备有限公司 一种基站切换方法及装置
WO2017029909A1 (ja) * 2015-08-17 2017-02-23 株式会社Ｎｔｔドコモ 無線通信システム、ゲートウェイ装置、移動管理エンティティ及び通信制御方法
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