WO2022165813A1 - 一种通信方法及装置 - Google Patents

一种通信方法及装置 Download PDF

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Publication number
WO2022165813A1
WO2022165813A1 PCT/CN2021/075875 CN2021075875W WO2022165813A1 WO 2022165813 A1 WO2022165813 A1 WO 2022165813A1 CN 2021075875 W CN2021075875 W CN 2021075875W WO 2022165813 A1 WO2022165813 A1 WO 2022165813A1
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WO
WIPO (PCT)
Prior art keywords
service
network element
network
information
terminal device
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PCT/CN2021/075875
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English (en)
French (fr)
Inventor
宗在峰
朱奋勤
Original Assignee
华为技术有限公司
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.)
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Publication date
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to PCT/CN2021/075875 priority Critical patent/WO2022165813A1/zh
Priority to CN202180069069.8A priority patent/CN116325821A/zh
Priority to EP21923929.0A priority patent/EP4274301A4/en
Priority to PCT/CN2021/080633 priority patent/WO2022165919A1/zh
Publication of WO2022165813A1 publication Critical patent/WO2022165813A1/zh

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0007—Control or signalling for completing the hand-off for multicast or broadcast services, e.g. MBMS
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/14—Reselecting a network or an air interface
    • H04W36/144—Reselecting a network or an air interface over a different radio air interface technology
    • H04W36/1443—Reselecting a network or an air interface over a different radio air interface technology between licensed networks
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
    • H04W4/06—Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services

Definitions

  • the present application relates to the field of wireless communication technologies, and in particular, to a communication method and device.
  • multicast/broadcast services are widely used, such as in high-definition video, autonomous driving, IoT devices, and public safety early warning.
  • the evolved multimedia broadcast multicast service (eMBMS) transmission was introduced into the 4th generation (4G) network.
  • the first service may be a multicast/broadcast service
  • data of the first service may be transmitted through an eMBMS transmission mode.
  • the 5th generation (5G) network has also introduced a multicast transmission method, that is, a multicast broadcast service (MBS) transmission method.
  • MBS multicast broadcast service
  • the present application provides a communication method and apparatus for sending data of a first service to the terminal device after the terminal device moves from the second network to the first network or from the first network to the second network.
  • an embodiment of the present application provides a communication method, which is applied to a terminal device moving from a second network to a first network, and the method is used to implement functions on the network element side of a core network.
  • the method can be applied to a session For the management network element or the chip in the session management network element, the embodiment of the present application does not limit the specific execution body of the method.
  • the session management network element obtains service area information of the first service, and the service area information is used to indicate that the first service is supported in the first network as the first transmission.
  • first information is sent, and the first information is used to establish a first transmission path, and the first transmission path is used to The first network sends the data of the first service to the terminal device in the second transmission mode; or, if the target cell is within the service area, the first information is not sent; wherein, The target cell is located in the first network.
  • the session management network element can determine whether the target cell is in the service area according to the service area information of the first service, and then perform different processing according to whether the target cell is in the service area, so as to facilitate the terminal equipment in a reasonable way.
  • Send the data of the first service For example, if the target cell is not in the service area, information 1 can be sent, and then the AS can send the data of the first service to the terminal device in the second transmission mode on the first network. If the target cell is in the service area, the information can not be sent. 1, and then the AS can send the data of the first service to the terminal device in the first transmission mode (ie, the eMBMS transmission mode) on the first network.
  • the first transmission mode ie, the eMBMS transmission mode
  • the service area information includes at least one of the following: an identifier of the public land mobile network PLMN corresponding to the service area; an identifier TAI of the tracking area corresponding to the service area; the service area corresponding to the identity of the cell.
  • the acquiring the service area information of the first service includes: receiving the service area information from a first core network element, where the first core network element includes any of the following: Multicast service network element, multicast session management network element, network open function network element, policy control network element, unified data storage network element, unified data management network element; or, receiving the service area information from the terminal device .
  • the receiving the service area information from the terminal device includes: receiving a first message from the terminal device, where the first message includes the service area information; wherein, The first message is a PDU session establishment request message or a PDU session modification request message.
  • the first message further includes a join request, where the join request is used to request to send the data of the first service to the terminal device in a third transmission manner in the second network .
  • the method further includes: acquiring information of the target cell; and determining whether the target cell is within the service area according to the information of the target cell.
  • the information of the target cell includes the TAI corresponding to the target cell and/or the identifier of the target cell.
  • acquiring the information of the target cell includes: receiving the information of the target cell from a mobility management network element.
  • the information of the target cell is carried in a session context request message from the mobility management network element, and the session context request message is used to request the terminal device for the first PDU session context, the first PDU session is associated with the first service.
  • the method further includes: if the session context request message does not carry the information of the target cell, determining that the target cell is not in the service area.
  • the sending the first information includes: receiving a session context request message from a mobility management network element, where the session context request message is used to request the context of the first PDU session of the terminal device , the first PDU session is associated with the first service; according to the session context request message, send the context of the first PDU session to the mobility management network element, where the context of the first PDU session includes the first information.
  • the not sending the context information includes: receiving a session context request message from the mobility management network element, where the session context request message is used to request a first PDU session of the terminal device
  • the context of the first PDU session is associated with the first service; according to the session context request message, the context of the first PDU session is sent to the mobility management network element, and the context of the first PDU session is The context does not include the first information.
  • the method further includes: releasing the second network for sending the first service to the terminal device Resources.
  • an embodiment of the present application provides a communication method.
  • the method is applied to a terminal device moving from a second network to a first network.
  • the method is used to implement functions on the network element side of the core network.
  • the method can be applied to mobile A mobility management network element or a chip in a mobility management network element, the embodiment of the present application does not limit the specific execution subject of the method.
  • the mobility management network element obtains service area information of the first service, and the service area information is used to indicate that the first service is supported in the first network as the first service area.
  • a service area for transmission in a transmission mode if the target cell of the terminal device is not in the service area, first information is sent, and the first information is used to establish a first transmission path, and the first transmission path is used for In the first network, the data of the first service is sent to the terminal device in the second transmission mode; or, if the target cell is within the service area, the context information is not sent; wherein , the target cell is located in the first network.
  • the mobility management network element can determine whether the target cell is in the service area according to the service area information of the first service, and then perform different processing according to whether the target cell is in the service area, so as to facilitate the terminal in a reasonable way.
  • the device sends data of the first service. For example, if the target cell is not in the service area, information 1 can be sent, and then the AS can send the data of the first service to the terminal device in the second transmission mode on the first network. If the target cell is in the service area, the information can not be sent. 1, and then the AS can send the data of the first service to the terminal device in the first transmission mode (ie, the eMBMS transmission mode) on the first network.
  • the first transmission mode ie, the eMBMS transmission mode
  • the service area information includes at least one of the following items: an identifier of a PLMN corresponding to the service area; a TAI corresponding to the service area; and an identifier of a cell corresponding to the service area.
  • the acquiring the service area information of the first service includes: receiving the service area information from a second core network element, where the second core network element includes any one of the following: Session management network elements, multicast service network elements, multicast session management network elements, network open function network elements, unified data storage network elements, and unified data management network elements.
  • the method further includes: acquiring information of the target cell; and determining whether the target cell is within the service area according to the information of the target cell.
  • the information of the target cell includes the TAI corresponding to the target cell and/or the identifier of the target cell.
  • acquiring information about the target cell includes: receiving information about the target cell from a source access network element of the terminal device, where the source access network element is located in the in the second network.
  • the method further includes: receiving the first information from the session management network element.
  • the method further includes: sending a second message to the session management network element, where the second message is used to acquire the first information.
  • the second message includes second information, and the second information is used to indicate that the first network is sent to the terminal device in the second transmission manner. business data.
  • the second message is a session context request message
  • the session context request message is used to request the context of the first PDU session of the terminal device, and the first PDU session is related to the first PDU session. a business association.
  • the method further includes: determining the first PDU session associated with the first service.
  • determining the first PDU session associated with the first service includes: determining the S-NSSAI and/or DNN according to the S-NSSAI and/or DNN of the first service
  • the PDU session corresponding to the DNN is the first PDU session associated with the first service; or, the first PDU session is used to receive the identifier of the first service from the session management network element, and the first PDU session is established.
  • An association relationship between a service and the first PDU session; according to the association relationship, the first PDU session associated with the first service is determined.
  • the method further includes: sending third information to the source access network element of the terminal device, the third information using For redirecting the terminal device to the target cell, the source access network element is located in the second network.
  • an embodiment of the present application provides a communication method.
  • the method is applied when a terminal device moves from a second network to a first network.
  • the method is used to implement functions on the network element side of an access network.
  • the method can be applied to The access network element or the chip in the access network element, the embodiment of the present application is not limited to the specific execution body of the method.
  • the access network element obtains the service area information of the first service, and the service area information is used to indicate that the first service is supported in the first network as the first service area.
  • a service area for transmission in a transmission mode if the target cell of the terminal device is not within the service area, send fourth information, where the fourth information is used to indicate that the first service is in the first network Allocate radio resources in the first network, and the radio resources are used to send the data of the first service to the terminal device in the second transmission mode in the first network; or, if the target cell is within the service area, then redirecting the terminal device to the target cell, or sending fifth information, where the fifth information is used to indicate that the radio resource is not allocated in the first network for the first service; wherein, The target cell is located in the first network.
  • the network element of the source access network can determine whether the target cell is in the service area according to the service area information of the first service, and then perform different processing according to whether the target cell is in the service area, so that it is convenient to send information to the service area in a reasonable way.
  • the terminal device sends data of the first service.
  • the service area information includes at least one of the following items: an identifier of a PLMN corresponding to the service area; a TAI corresponding to the service area; and an identifier of a cell corresponding to the service area.
  • acquiring the service area information of the first service includes: receiving the service area information from a third core network element, where the third core network element includes any one of the following: session management A network element, a mobility management network element, a multicast session management network element; or, receiving the service area information from the terminal device.
  • the receiving the service area information from the terminal device includes: receiving an RRC message from the terminal device, where the RRC message includes the service area information.
  • an embodiment of the present application provides a communication method, which is applied to a terminal device moving from a second network to a first network, and the method is used to implement functions on the network element side of the core network.
  • the method can be applied to mobile A mobility management network element or a chip in a mobility management network element, the embodiment of the present application does not limit the specific execution subject of the method.
  • the mobility management network element obtains the information of the target cell of the terminal equipment, and the target cell is located in the first network; and sends the information of the target cell to the session management network element. information.
  • the information of the target cell includes the TAI corresponding to the target cell and/or the identifier of the target cell.
  • sending the information of the target cell to the session management network element includes: determining that the terminal device has joined the multicast session of the first service, or determining that the terminal device uses a third transmission mode receiving the data of the first service; sending a session context request message to the session management network element, where the session context request message includes the information of the target cell; wherein the session context request message is used to request the terminal
  • the context of the first PDU session of the device, the first PDU session is associated with the first service.
  • the method further includes: determining the first PDU session associated with the first service.
  • determining the first PDU session associated with the first service includes: determining the S-NSSAI and/or DNN according to the S-NSSAI and/or DNN of the first service
  • the PDU session corresponding to the DNN is the first PDU session associated with the first service; or, the first PDU session is used to receive the identifier of the first service from the session management network element, and the first PDU session is established.
  • An association relationship between a service and the first PDU session; according to the association relationship, the first PDU session associated with the first service is determined.
  • the method further includes: determining that the first service supports transmission through the first network.
  • an embodiment of the present application provides a communication method, which is applied to a terminal device moving from a second network to a first network, and the method is used to implement functions on the network element side of a core network.
  • the method can be applied to a session For the management network element or the chip in the session management network element, the embodiment of the present application does not limit the specific execution body of the method.
  • the session management network element receives second information or fourth information, where the second information is used to instruct the terminal device in the first network in a second transmission manner Data of the first service is sent, and the fourth information is used to indicate that radio resources are allocated in the first network for the first service, and the radio resources are used in the first network to use the second
  • the transmission mode sends the data of the first service to the terminal device; according to the second information or the fourth information, the first information is sent, and the first information is used to establish a first transmission path, and the first transmission The path is used to send the data of the first service to the terminal device in the first network in a second transmission manner.
  • the method further includes: sending service area information of the first service to a mobility management network element or a source access network element of the terminal device, where the service area information is used for Indicates a service area that supports transmission of the first service in the first transmission manner in the first network, and the source access network element is located in the second network.
  • the method further includes: sending the identifier of the first service to the mobility management network element through a first PDU session of the terminal device, where the first PDU session is associated with the first service .
  • the method further includes: instructing a user plane network element to send the data of the first service to the terminal device through a transmission path corresponding to the second transmission mode.
  • an embodiment of the present application provides a communication method, which is applied to a terminal device moving from a second network to a first network, and the method is used to implement functions on the network element side of the core network.
  • the method can be applied to mobile A mobility management network element or a chip in a mobility management network element, the embodiment of the present application does not limit the specific execution subject of the method.
  • the mobility management network element receives fourth information from the source access network element of the terminal device, where the fourth information is used to indicate that the first service is located where the first service is located.
  • Allocate wireless resources in the first network are used to send the data of the first service to the terminal device in the second transmission mode in the first network; send the second information to the session management network element or the fourth information, the second information is obtained according to the fourth information, and the second information is used to indicate that the Data of the first business.
  • the embodiments of the present application provide a communication method, and the method is used to implement functions on the terminal side.
  • the method can be applied to a terminal device or a chip in the terminal device, and the embodiments of the present application are not limited to the specific method of the method.
  • Executive body Taking the method applied to a terminal device as an example, the terminal device acquires sixth information, where the sixth information is used to indicate that the second network supports sending the data of the first service in the third transmission mode; The network element in the second network sends a join request, where the join request is used for requesting to send the data of the first service to the terminal device in the second network in the third transmission manner.
  • the terminal device can determine, according to the sixth information, whether the network accessed by the terminal device supports sending the data of the first service in the third transmission mode. If it is not supported, the terminal device may not send a join request, so that the terminal device can determine whether to send a join request through the above judgment after accessing the second network, so as to receive the data of the first service in a reasonable way.
  • the sixth information includes identifiers of one or more networks, the one or more networks include the second network, and the one or more networks support the third transmission way to send the data of the first service.
  • the identifiers of the one or more networks are identifiers of one or more PLMNs.
  • the sixth information further includes the DNN and/or the S-NSSAI corresponding to the second network.
  • the method further includes: sending the join request to a network element in the second network through a first PDU session of the terminal device, the DNN and the corresponding DNN of the first PDU session.
  • the S-NSSAI is the same as the DNN and/or the S-NSSAI corresponding to the second network.
  • the acquiring the sixth information of the first service of the terminal device includes: receiving the sixth information from an application server; or, receiving the sixth information from a multicast service network element Six information.
  • the embodiments of the present application provide a communication method, which is used to implement functions on the application server side.
  • the method can be applied to an application server or a chip in an application server, and the embodiments of the present application are not limited to the specifics of the method. executor.
  • the application server receives a first notification message from the network element of the fourth core network, where the first notification message is used to notify the terminal device to access the second network, and the second network supports the Send the data of the first service in the third transmission mode; send seventh information to the network element of the fifth core network, where the seventh information is used to indicate the third transmission mode to the terminal device in the second network Send the data of the first service.
  • the application server can determine whether the network accessed by the terminal device supports sending the data of the first service in the third transmission mode, and if so, the core network element can be instructed to add the terminal device to the multicast of the first service. If the session is not supported, the terminal device may not be instructed to join the multicast session of the first service, so that after the terminal device accesses the second network, the data of the first service can be sent to the terminal device in a reasonable manner.
  • the method further includes: sending a first subscription request, where the first subscription request is used to request to send the first notification message after the terminal device accesses the second network.
  • sending the seventh information to the network element of the fifth core network includes: sending the seventh information to the network element of the fifth core network through an application policy session corresponding to the first session, the A session is a PDU session or PDN connection of the terminal device associated with the first service.
  • the seventh information includes an identifier corresponding to when the first service is transmitted in the third transmission manner.
  • the embodiments of the present application provide a communication method, which is used to implement functions on the application server side.
  • the method may be applied to an application server or a chip in an application server, and the embodiments of the present application are not limited to the specifics of the method. executor.
  • the application server receives a second notification message from the network element of the sixth core network, where the second notification message is used to instruct the terminal device to access the first network; according to the second notification message , send eighth information to the seventh core network element, where the eighth information is used to establish a second transmission path, and the second transmission path is used to send the terminal to the terminal in the fifth transmission mode in the first network
  • the device sends the data of the first service.
  • the application server can know that the terminal device is connected to the first network according to the notification message of the core network element, and then the application server can send the data of the first service to the terminal device through the transmission path corresponding to the fifth transmission mode.
  • the method further includes: sending the data of the first service to the terminal device through the second transmission path, and the destination address of the data of the first service is the terminal device IP address.
  • the method further includes: sending a second subscription request, where the second subscription request is used to request to send the second notification message after the terminal device accesses the first network.
  • the second subscription request includes ninth information, where the ninth information is used to indicate that a cell in the first network accessed by the terminal device does not support the The second notification message is sent when the data of the first service is sent in a transmission mode.
  • the second subscription request includes service area information of the first service, where the service area information is used to indicate that the first service is supported in the first network in the first transmission mode The service area for transmission, where the service area information is used to determine whether the target cell supports sending the data of the first service in the first transmission mode.
  • the second notification message includes information of a cell in the first network accessed by the terminal device; the method further includes: determining the cell according to the information of the cell Sending the data of the first service in the first transmission mode is not supported.
  • an embodiment of the present application provides a communication device, where the communication device may be a core network element (such as a session management network element or a mobility management network element) or a chip disposed inside the core network element.
  • the communication device has the function of implementing any one of the first aspect, the second aspect, the fourth aspect to the sixth aspect, for example, the communication device includes performing any one of the first aspect to the sixth aspect.
  • the modules or units or means (means) corresponding to the steps, the functions or units or means may be implemented by software, or by hardware, or by executing corresponding software by hardware.
  • the communication device includes a processing unit and a communication unit, wherein the communication unit can be used to send and receive signals to implement communication between the communication device and other devices, for example, the communication unit is used to receive data from Configuration information of the terminal device; the processing unit can be used to perform some internal operations of the communication device.
  • the communication device includes a processor, and may further include a transceiver, where the transceiver is used to send and receive signals, and the processor executes program instructions to accomplish the first and second aspects above .
  • the method in any possible design or implementation manner of the fourth aspect to the sixth aspect.
  • the communication apparatus may further include one or more memories, the memories are used for coupling with the processor, and the memories may store and implement any one of the first aspect, the second aspect, the fourth aspect to the sixth aspect.
  • the processor can execute computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, the communication device can implement the first aspect, the second aspect, the fourth aspect to the sixth aspect. method in any possible design or implementation.
  • the communication device includes a processor, which may be operative to couple with the memory.
  • the memory may store necessary computer programs or instructions to implement the functions involved in any of the above-mentioned first, second, fourth to sixth aspects.
  • the processor can execute computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, the communication device can implement the first aspect, the second aspect, the fourth aspect to the sixth aspect. method in any possible design or implementation.
  • the communication device includes a processor and an interface circuit, wherein the processor is configured to communicate with other devices through the interface circuit, and execute the above-mentioned first aspect, second aspect, fourth aspect to The method in any possible design or implementation of the sixth aspect.
  • an embodiment of the present application provides a communication device, where the communication device may be an access network element or a chip provided inside the access network element.
  • the communication device has the function of implementing the third aspect.
  • the communication device includes modules or units or means corresponding to the steps involved in the third aspect.
  • the functions, units or means may be implemented by software, or by It can be realized by hardware, and can also be realized by executing corresponding software by hardware.
  • the communication device includes a processing unit and a communication unit, wherein the communication unit can be used to send and receive signals to implement communication between the communication device and other devices, for example, the communication unit is used to receive data from Configuration information of the terminal device; the processing unit can be used to perform some internal operations of the communication device.
  • the communication device includes a processor, and may further include a transceiver, where the transceiver is configured to send and receive signals, and the processor executes program instructions to complete any possible design in the third aspect above or a method in an implementation.
  • the communication apparatus may further include one or more memories, the memories are used for coupling with the processor, and the memories may store necessary computer programs or instructions for realizing the functions involved in the third aspect.
  • the processor can execute the computer program or instructions stored in the memory, and when the computer program or instructions are executed, cause the communication apparatus to implement the method in any possible design or implementation manner of the third aspect.
  • the communication device includes a processor, which may be operative to couple with the memory.
  • the memory may hold the necessary computer programs or instructions to implement the functions involved in any of the above-mentioned third aspects.
  • the processor can execute the computer program or instructions stored in the memory, and when the computer program or instructions are executed, cause the communication apparatus to implement the method in any possible design or implementation manner of the third aspect.
  • the communication device includes a processor and an interface circuit, wherein the processor is configured to communicate with other devices through the interface circuit, and execute any of the possible designs or implementations of the third aspect above. Methods.
  • an embodiment of the present application provides a communication device, where the communication device may be a terminal device or a chip provided inside the terminal device.
  • the communication device has the function of implementing the seventh aspect.
  • the communication device includes modules or units or means corresponding to the steps involved in the seventh aspect.
  • the functions, units or means can be implemented by software, or by It can be realized by hardware, and can also be realized by executing corresponding software by hardware.
  • the communication device includes a processing unit and a communication unit, wherein the communication unit can be used to send and receive signals to implement communication between the communication device and other devices, for example, the communication unit is used to receive data from Configuration information of the terminal device; the processing unit can be used to perform some internal operations of the communication device.
  • the communication device includes a processor, and may further include a transceiver, where the transceiver is used to send and receive signals, and the processor executes program instructions to complete any possible design in the seventh aspect above or a method in an implementation.
  • the communication apparatus may further include one or more memories, the memories are used for coupling with the processor, and the memories may store necessary computer programs or instructions for realizing the functions involved in the seventh aspect.
  • the processor may execute the computer program or instructions stored in the memory, and when the computer program or instructions are executed, cause the communication apparatus to implement the method in any possible design or implementation manner of the seventh aspect.
  • the communication device includes a processor, which may be operative to couple with the memory.
  • the memory may store necessary computer programs or instructions to implement the functions involved in the seventh aspect above.
  • the processor may execute the computer program or instructions stored in the memory, and when the computer program or instructions are executed, cause the communication apparatus to implement the method in any possible design or implementation manner of the seventh aspect.
  • the communication device includes a processor and an interface circuit, wherein the processor is configured to communicate with other devices through the interface circuit, and execute any of the possible designs or implementations of the seventh aspect above. Methods.
  • an embodiment of the present application provides a communication device, where the communication device may be an application server or a chip provided inside the application server.
  • the communication device has the function of implementing the eighth aspect or the ninth aspect.
  • the communication device includes a module or unit or means corresponding to the steps involved in the eighth aspect or the ninth aspect.
  • the function or unit or The means may be implemented by software, or by hardware, or by executing corresponding software by hardware.
  • the communication device includes a processing unit and a communication unit, wherein the communication unit can be used to send and receive signals to implement communication between the communication device and other devices, for example, the communication unit is used to receive data from Configuration information of the terminal device; the processing unit can be used to perform some internal operations of the communication device.
  • the communication device includes a processor, and may further include a transceiver, where the transceiver is used to send and receive signals, and the processor executes program instructions to complete the eighth aspect or the ninth aspect. method in any possible design or implementation.
  • the communication device may further include one or more memories, the memories are used for coupling with the processor, and the memories may store necessary computer programs or instructions for realizing the functions involved in the eighth aspect or the ninth aspect.
  • the processor can execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, make the communication device implement any of the possible designs or implementations of the eighth aspect or the ninth aspect. method.
  • the communication device includes a processor, which may be operative to couple with the memory.
  • the memory may store necessary computer programs or instructions to implement the functions involved in the eighth or ninth aspect above.
  • the processor can execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, make the communication device implement any of the possible designs or implementations of the eighth aspect or the ninth aspect. method.
  • the communication device includes a processor and an interface circuit, wherein the processor is configured to communicate with other devices through the interface circuit, and execute any possible design of the eighth aspect or the ninth aspect or method in the implementation.
  • the processor may be implemented by hardware or software.
  • the processor When implemented by hardware, the processor may be a logic circuit, an integrated circuit, or the like. ;
  • the processor When implemented by software, the processor may be a general-purpose processor implemented by reading software codes stored in memory.
  • the above processors may be one or more, and the memory may be one or more.
  • the memory may be integrated with the processor, or the memory may be provided separately from the processor. In a specific implementation process, the memory and the processor may be integrated on the same chip, or may be separately provided on different chips.
  • the embodiment of the present application does not limit the type of the memory and the manner of setting the memory and the processor.
  • an embodiment of the present application provides a communication system, where the communication system includes the session management network element in the foregoing first aspect and the mobility management network element in the foregoing fourth aspect; or, the communication system includes the foregoing fourth aspect.
  • the present application provides a computer-readable storage medium, where computer-readable instructions are stored in the computer storage medium, and when the computer reads and executes the computer-readable instructions, the computer is made to execute the above-mentioned first aspect
  • the method in any possible design to the ninth aspect.
  • the present application provides a computer program product that, when the computer reads and executes the computer program product, causes the computer to execute the method in any possible design of the first to ninth aspects.
  • the present application provides a chip, the chip includes a processor, the processor is coupled to a memory, and is configured to read and execute a software program stored in the memory, so as to implement the above-mentioned first to sixth aspects A method in any possible design of the nine aspects.
  • FIG. 1 is a schematic diagram of a network architecture for independent deployment of a first network according to an embodiment of the present application
  • FIG. 2 is a schematic diagram of a network architecture for independent deployment of a second network according to an embodiment of the present application
  • FIG. 3 is a schematic diagram of a network architecture for joint deployment of a first network and a second network according to an embodiment of the present application
  • FIG. 4 is a schematic flowchart of data transmission of a first service on a 4G network and a 5G network according to an embodiment of the present application;
  • FIG. 5 is a schematic flowchart corresponding to the communication method provided in Embodiment 1 of the present application.
  • FIG. 6 is a schematic flowchart corresponding to the communication method provided in Embodiment 2 of the present application.
  • FIG. 7 is a schematic flowchart corresponding to the communication method provided in Embodiment 3 of the present application.
  • FIG. 8 is a schematic flowchart corresponding to the communication method provided in Embodiment 4 of the present application.
  • FIG. 9 is a schematic flowchart corresponding to the communication method provided in Embodiment 5 of the present application.
  • FIG. 10 is a schematic flowchart corresponding to the communication method provided in Embodiment 6 of the present application.
  • FIG. 11 is a possible exemplary block diagram of the apparatus involved in the embodiment of the application.
  • FIG. 12 is a schematic structural diagram of a core network element according to an embodiment of the present application.
  • FIG. 13 is a schematic structural diagram of a network element of an access network according to an embodiment of the present application.
  • FIG. 14 is a schematic structural diagram of a terminal device according to an embodiment of the present application.
  • FIG. 15 is a schematic structural diagram of an application server provided by an embodiment of the present application.
  • the first network and the second network may be networks supporting different communication standards, the first network may also be referred to as a network of a first communication standard, and the second network may also be referred to as a network of a second communication standard.
  • the first network may be a 4G network
  • the second network may be a 5G network, where the 5G network may also be called a 5G communication system
  • the 4G network may also be called an evolved packet system (EPS) network or 4G communication system.
  • EPS evolved packet system
  • the first network may be a certain public land mobile network (public land mobile network, PLMN) in the 4G network
  • the second network may be a certain PLMN in the 5G network.
  • first network and the second network may also be other types of networks, which are not specifically limited.
  • description will be given by taking as an example that the first network is a 4G network and the second network is a 5G network.
  • a protocol data network (PDN) connection refers to a data transmission channel established for a terminal device in a first network (such as a 4G network).
  • a PDN connection may include one or more bearers (ie EPS bearers).
  • the context of the PDN connection may include an internet protocol (IP) address used by the PDN connection, and the context of each EPS bearer in the PDN connection.
  • the context of the EPS bearer may include quality of service (quality of service, QoS) information of the EPS bearer, an EPS bearer identity (EPS bearer identity, EBI), a traffic flow template (traffic flow template, TFT) and the like.
  • QoS quality of service
  • EBI EPS bearer identity
  • TFT traffic flow template
  • a protocol data unit (PDU) session refers to a data transmission channel established for a terminal device in a second network (such as a 5G network).
  • a PDU session can include one or more QoS flows.
  • the context of the PDU session may include the IP address used by the PDU session, and information for each QoS flow in the PDU session.
  • the information of the QoS flow may include QoS information of the QoS flow, an identity of the QoS flow (QoS flow identity, QFI), and a QoS flow template.
  • the PDN connection in the 4G network may be a corresponding relationship between the PDN connection in the 4G network and the PDU session in the 5G network.
  • the 4G network and the 5G network coexist, when the terminal device moves from the 5G network to the 4G network, it is established in the 4G network.
  • the context of the PDN connection 1 can be obtained according to the context of the PDU session 1, and then the PDN connection 1 can be established according to the context of the PDN connection 1.
  • the implementation of obtaining the context of the PDN connection 1 according to the context of the PDU session 1 may refer to the prior art.
  • the IP addresses of PDU session 1 and PDN connection 1 may be the same;
  • PDU session 1 includes the first QoS flow, which may be a service data flow or a group of service data flows, and PDN connection 1 may include the first EPS bearer , the first QoS flow can be mapped to the first EPS bearer according to the predefined mapping rule, and then the context of the first EPS bearer can be obtained according to the information of the first QoS flow.
  • the embodiments of the present application involve five transmission modes, which are a first transmission mode, a second transmission mode, a third transmission mode, a fourth transmission mode, and a fifth transmission mode.
  • the first transmission mode may be a multicast transmission mode of the first network (such as a 4G network), and the multicast transmission mode may be understood as "point to multi-point" (point to multi-point, PTM) communication.
  • the first transmission manner may be applicable to a scenario where the first network and the second network are jointly deployed (or in other words, the first network and the second network coexist), or may also be applicable to a scenario where the first network is independently deployed.
  • the first transmission manner may refer to sending data to the terminal device through a multicast bearer, where the multicast bearer may also be referred to as an MBMS bearer.
  • the first transmission mode may also be referred to as a multicast bearer transmission mode, or an MBMS bearer transmission mode, or an eMBMS transmission mode.
  • the destination address of the data packet is a multicast IP address.
  • the fifth transmission mode may be a unicast transmission mode of the first network (such as a 4G network), and the unicast transmission mode may be understood as "point-to-point" (point to point, PTP) communication.
  • the fifth transmission manner may be applicable to a scenario where the first network and the second network are jointly deployed, or may also be applicable to a scenario where the first network is independently deployed.
  • the fifth transmission mode may refer to sending data to the terminal device through a PDN connection (or an EPS bearer, an EPS bearer may also be referred to as an EPS unicast bearer or a unicast bearer).
  • the destination address of the data packet is the IP address of the terminal device.
  • the second transmission mode may be another unicast transmission mode of the first network (such as a 4G network).
  • the second transmission manner may be applicable to a scenario where the first network and the second network are jointly deployed.
  • the data is also sent to the terminal device through the PDN connection of the first network.
  • the difference between the second transmission mode and the fifth transmission mode is: in the second transmission mode, the data is first sent to the multicast user plane network element, and then sent by the multicast user plane network element to the user plane network connected to the PDN of the terminal device.
  • the user plane network element sends the data to the terminal device through the PDN connection; and in the fifth transmission mode, the data does not go through the multicast user plane network element.
  • the destination address of the data packet is a multicast IP address.
  • the third transmission mode may be a multicast transmission mode of the second network (such as a 5G network).
  • the third transmission manner may be applicable to a scenario where the first network and the second network are jointly deployed, or may also be applicable to a scenario where the second network is independently deployed.
  • a corresponding multicast session can be created for the multicast service.
  • One multicast service may correspond to one multicast session, one multicast service may include one or more service data streams, and multiple service data streams may correspond to one or more multicast QoS streams, that is, a multicast session
  • the data of the multicast service within the network may be transmitted in the form of a multicast QoS stream, which is not limited in this embodiment of the present application.
  • the third transmission mode may also be referred to as 5MBS or 5G MBS transmission mode.
  • the third transmission mode may include shared MBS delivery mode (shared MBS delivery) and individual MBS delivery mode (individual MBS delivery).
  • shared MBS transmission mode means that the data is first sent to the multicast user plane network element, and the multiple The multicast user plane network element directly sends the data to the access network element through the shared tunnel, and then the access network element sends it to the terminal device;
  • the separate MBS transmission mode means that the data is first sent to the multicast user plane network element, and then the data is sent to the multicast user plane network element.
  • the broadcast user plane network element sends data to the anchor user plane network element of the PDU session of the terminal equipment, and the anchor point user plane network element sends the data to the terminal equipment through the PDU session.
  • the destination address of the data packet is a multicast IP address.
  • the fourth transmission mode may be a unicast transmission mode of the second network (such as a 5G network).
  • the fourth transmission manner may be applicable to a scenario where the first network and the second network are jointly deployed, or may also be applicable to a scenario where the second network is independently deployed.
  • the fourth transmission mode may refer to sending data to the terminal device through a PDU session of the terminal device; wherein, the data in the PDU session may be transmitted in the form of a QoS stream, which is not limited in this embodiment of the present application.
  • the difference from the separate MBS transmission mode in the third transmission mode is that in the fourth transmission mode, the data packet is not transmitted through a multicast session, and the destination address of the data packet is the IP address of the terminal device.
  • multicast in the embodiments of the present application is a broad concept, and may include multicast and/or broadcast, that is, the multicast service transmission in the embodiments of the present application can be applied to both For multicast service transmission, it can also be applied to broadcast service transmission. Understandably, the "multicast” mentioned in the embodiments of the present application may be replaced with “multicast” or “broadcast” or “multicast/broadcast”.
  • FIG. 1 is a schematic diagram of a possible network architecture for independent deployment of the first network according to an embodiment of the present application.
  • the first network is a 4G network
  • the network architecture can support eMBMS of the 4G network.
  • the network architecture may include the following possible devices or network elements:
  • Terminal equipment also known as user equipment (UE), terminal (terminal), mobile station (mobile station, MS), mobile terminal (mobile terminal, MT), customer premise equipment (Customer Premise Equipment) , CPE), home gateway (Residential Gateway, RG), etc.
  • Terminal equipment can be deployed on land, including indoors, outdoors, and/or handheld or vehicle; it can also be deployed on water (such as ships, etc.); it can also be deployed in the air (such as aircraft, balloons, and satellites, etc.).
  • Terminal devices may include handheld devices, in-vehicle devices, wearable devices, or computing devices with wireless communication capabilities.
  • the terminal device may be a mobile phone (mobile phone), a tablet computer or a computer with a wireless transceiver function.
  • the terminal device may also be a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in unmanned driving, a wireless terminal in telemedicine, intelligent A wireless terminal in a power grid, a wireless terminal in a smart city, and/or a wireless terminal in a smart home, etc.
  • VR virtual reality
  • AR augmented reality
  • Access network element the node or device that connects the terminal device to the wireless network, and the access network element may also be called a radio access network (RAN) device or an access network device.
  • the network elements of the access network include, but are not limited to, a new generation base station (generation node B, gNB), an evolved node B (evolved node B, eNB), a next generation node B (next generation eNB, ng-eNB), Wireless backhaul equipment, radio network controller (RNC), node B (node B, NB), base station controller (BSC), base transceiver station (base transceiver station, BTS), home base station ((home evolved nodeB, HeNB) or (home node B, HNB)), baseband unit (BBU), transmitting and receiving point (TRP), transmitting point (TP), mobile switching Center, access point (AP) in wireless local area networks (WLAN), etc.
  • generation node B, gNB new generation base station
  • eNB evolved node B
  • the access network element may also be a module or unit that completes some functions of the base station, such as a centralized unit (central unit, CU) or a distributed unit (distributed unit, DU).
  • a centralized unit central unit, CU
  • a distributed unit distributed unit
  • the embodiments of the present application do not limit the specific technology and specific device form adopted by the network element of the access network.
  • the network element of the access network may be an eNB.
  • Mobility management network element responsible for authentication, authorization, and mobility management of terminal equipment.
  • the mobility management network element may be a mobility management entity (mobility management entity, MME).
  • MME mobility management entity
  • Multicast service network element used to save subscription data, allocate temporary mobile group identity (TMGI), initiate or terminate MBMS bearer resources, etc.
  • the multicast service network element may be a multimedia broadcast multicast service center (broadcast-multicast service center, BM-SC).
  • Multicast service gateway used for receiving the data of the multicast service, and sending the data of the multicast service to the network element of the access network.
  • the multicast service gateway can be an MBMS gateway (MBMS gateway, MBMS-GW).
  • the MBMS-GW receives the multicast service data from the BM-SC through the SGimb interface with the BM-SC, and sends the data to the BM-SC.
  • the data of the multicast service is sent to the network element of the access network.
  • Application server It is the data source of the service and is used to send the data of the service to the terminal device.
  • the application server may be a group communication service application server (GSC AS).
  • SGW Serving gateway
  • PGW Packet data network gateway
  • PGW-U PGW user plane
  • PGW-C PGW control plane
  • PGW- C is the control plane network element of the 4G network, providing control plane services for the PDN connection of the terminal equipment
  • PGW-U is the user plane network element of the 4G network, providing user plane services for the PDN connection of the terminal equipment.
  • the SGW and the PGW may be co-located, and when the SGW and the PGW are co-located, it may be referred to as an S/P-GW.
  • S/P-GW the SGW and the PGW are combined as an example for illustration.
  • Policy control network element responsible for generating policies for users to establish data bearer.
  • the policy control network element may be a policy and charging rules function (policy and charging rules function, PCRF) network element.
  • Data management network element used to save the subscription data of the user.
  • the data management network element may be a home subscriber server (HSS).
  • HSS home subscriber server
  • network architecture shown in FIG. 1 except for the terminal equipment and the network elements of the access network, other network elements may be referred to as core network network elements.
  • the network architecture shown in FIG. 1 may also include other possible devices or network elements, which are not specifically limited.
  • the following describes the transmission paths when the data of the first service is transmitted using different transmission modes.
  • the AS may send the data of the first service to the terminal device through the first transmission mode (ie, the eMBMS transmission mode).
  • the transmission path corresponding to the eMBMS transmission mode can be: AS ⁇ BM-SC ⁇ MBMS-GW ⁇ eNB ⁇ terminal device, that is, the AS sends data to the BM-SC through the MB2-U interface, and the BM-SC sends the data to the BM-SC through the SGimb interface.
  • MBMS-GW, MBMS-GW sends data to eNB through M1 interface, and then eNB sends data to terminal equipment through Uu interface (or called air interface).
  • the AS may also send the data of the first service to the terminal device through the fifth transmission manner.
  • the transmission path corresponding to the fifth transmission mode may be: AS ⁇ S/P-GW ⁇ eNB ⁇ terminal device, that is, the AS sends data to the S/P-GW through the SGi interface, and the S/P-GW sends the data to the S/P-GW through the S1-U interface.
  • the data is sent to the eNB, and then the eNB sends the data to the terminal device through the Uu interface.
  • the transmission path corresponding to the fifth transmission mode may be: AS ⁇ PGW-U network element ⁇ SGW network element ⁇ eNB ⁇ terminal device.
  • FIG. 2 is a schematic diagram of a possible network architecture for independent deployment of the second network according to an embodiment of the present application.
  • the second network is a 5G network
  • the network architecture can support the MBS of the 5G network.
  • the network architecture may include the following possible devices or network elements:
  • the network element of the access network may be a gNB.
  • Mobility management network element used to authenticate and authorize the user, and manage the mobility of the user.
  • the mobility management network element may be an access and mobility management function (AMF) network element.
  • AMF access and mobility management function
  • Session management network element used for session management, IP address allocation and management of terminal equipment, selection and management of user plane functions.
  • the session management network element may be a session management function (session management function, SMF) network element.
  • User plane network element used to receive user plane data and send it to the access network element.
  • the user plane network element may be a user plane function (UPF) network element.
  • UPF user plane function
  • Policy control network element used to provide a unified policy framework for guiding network behavior, and to provide policy rule information for control plane functional network elements.
  • the policy control network element may be a policy control function (PCF) network element.
  • PCF policy control function
  • Multicast session management network element it is a session management network element for controlling multicast services.
  • the multicast session management network element may be a multicast/broadcast (MB)-SMF network element, and the MB-SMF controls the establishment of a path between the MB-UPF and the access network network element.
  • MB multicast/broadcast
  • Multicast user plane network element used to transmit data of multicast services, etc.
  • the multicast user plane network element can be an MB-UPF network element.
  • Application server It is the source of service data and is used to send service data to terminal equipment.
  • the application server can also be replaced by an application function (AF) network element.
  • AF application function
  • Network exposure function (NEF) network element Provide 5G network capabilities and events to the outside world, and receive related external messages.
  • Multicast service network element For example, in a 5G network, the multicast service network element may be a multicast/broadcast service function (MBSF) network element, and the MBSF network element may include the MBSF control plane (ie MBSF). -C) network element and MBSF user plane (ie MBSF-U) network element.
  • MBSF multicast/broadcast service function
  • -C MBSF control plane
  • MBSF-U MBSF user plane
  • the MBSF-C network element has the functions of the service layer, such as supporting the streaming (streaming) protocol, supporting the reliable retransmission protocol, etc., and the MBSF-C network element can also send a service announcement to the terminal equipment.
  • the MBSF-C network element can be an optional network element.
  • the AS can directly interface with the MBSF-C network element to send service requirements to the core network, and then the MBSF-C network element communicates with the MBSF-C network element.
  • the SMF network element interface to create a multicast session (optionally, the MBSF-C network element can also interface with the MB-SMF network element through the NEF network element), or the AS can also interface with the NEF network element first, and then the NEF network element can interface with the MB-SMF network element.
  • the MBSF-C network element interfaces, and then the MBSF-C network element interfaces with the MB-SMF network element.
  • the MBSF-C network element may be co-located with the NEF network element.
  • the main function of the MBSF-U network element is to process the data packets of the multicast service, such as encapsulating the data packets according to the stream protocol, encrypting the data packets, and encoding the data packets.
  • the MBSF-U network element may be an optional network element. If the data packet of the multicast service needs to be processed by the core network, the AS may first send the data packet to the MBSF-U network element, and the MBSF-U network element will send the data packet to the MBSF-U network element. After processing, it is sent to the MB-UPF network element. It should be understood that in the following embodiments of the present application, the AS sends the data packet to the MB-UPF network element as an example for description. In specific implementation, the AS may also first send the data packet to the MBSF-U network element, and the MBSF -U network element sends it to MB-UPF network element after processing.
  • the network architecture shown in FIG. 2 above may also include other possible devices or network elements, such as a unified data repository (UDR) and data management network elements.
  • the data management network elements may be unified Data management network element (unified data management, UDM).
  • the following describes the transmission paths when different transmission modes are used to transmit the first service.
  • the AS may send the data of the first service to the terminal device through the third transmission mode (ie, the 5MBS transmission mode).
  • the AS can send the data to the MB-UPF network element (the N6 interface or the MB2-U interface in FIG. 2, that is, the direct connection between the AS and the MB-UPF network element). interface).
  • the access network element supports 5G MBS
  • the MB-UPF network element can pass the shared tunnel (MB-N3 interface) between the MB-UPF network element and the access network element.
  • the access network element sends a piece of data, and the access network element can send the data to multiple terminal devices) to send the data to the access network element.
  • the network element of the access network can flexibly decide the playback mode, that is, the PTM mode or the PTP mode, according to the air interface conditions and the number of terminals listening to the service.
  • the access network element for the PTM method, the access network element only sends one piece of data, which can be received by multiple terminal devices; for the PTP method, the access network element sends one piece of data only by one terminal device. take over.
  • the network element of the access network may adopt the PTM mode and the PTP mode at the same time.
  • the terminal device 1 and the terminal device 2 adopt the PTM mode
  • the terminal device 3 adopts the PTP mode.
  • the transmission path corresponding to the shared MBS transmission mode in the third transmission mode is: AS ⁇ MB-UPF network element ⁇ gNB ⁇ terminal device. If the access network element does not support 5G MBS, the MB-UPF network element can send data to the anchor UPF network element of the PDU session, and then the UPF network element can send data to the terminal device through the access network element through the PDU session. Sending data, therefore, the transmission path corresponding to the independent MBS transmission mode in the third transmission mode may be: AS ⁇ MB-UPF network element ⁇ UPF network element ⁇ gNB ⁇ terminal device.
  • the AS may also send the data of the first service to the terminal device through the fourth transmission manner.
  • the transmission path corresponding to the fourth transmission mode may be: AS ⁇ UPF network element ⁇ gNB ⁇ terminal device, that is, the AS sends data to the anchor UPF network element of the PDU session (the relationship between the AS and the UPF network element is not shown in the figure for now). interface), and then the UPF network element can send data to the terminal device through the PDU session.
  • FIG. 3 is a schematic diagram of a possible network architecture for joint deployment of the first network and the second network according to the embodiment of the present application.
  • the first network is a 4G network
  • the second network is a 5G network.
  • the network architecture can support eMBMS of the 4G network and MBS of the 5G network.
  • the network architecture may include network elements in the 4G network, network elements in the 5G network, network elements shared by the 4G network and the 5G network (or network elements jointly set up by the 4G network and the 5G network), AS and terminal equipment.
  • the network elements in the 4G network may include the first access network element (ie the eNB in the 4G network), the first mobility management network element (ie the MME in the 4G network), the SGW, the MBMS-GW, and the like.
  • the network elements in the 5G network may include the second access network element (ie the gNB in the 5G network), the second mobility management network element (ie the AMF network element in the 5G network), MB-UPF, MB-SMF, etc. .
  • the network elements shared by the 4G network and the 5G network may include session management network elements (ie PGW-C+SMF), user plane network elements (ie PGW-U+UPF), MBSF+BM-SC, and policy control network elements (ie PCF). network element), etc.
  • the PGW-C+SMF may include the functions of the SMF network element and the PGW-C network element.
  • SMF+PGW-C can also be called PGW-C+SMF, as long as the network elements including the functions of the SMF network element and the PGW-C network element are the same as this network element.
  • "+" in the embodiment of this application means that the two network elements are co-located.
  • the UPF+PGW-U may include the functions of the UPF network element and the PGW-U network element.
  • UPF+PGW-U may also be called PGW-U+UPF, as long as the network elements including the functions of the UPF network element and the PGW-U network element are the same as this network element.
  • MBSF+BM-SC may include the functions of MBSF network elements and BM-SC.
  • MBSF+BM-SC may also be abbreviated as MBSF (that is, synthesizing the functions of BM-SC into MBSF network elements), as long as the network elements including the functions of MBSF network elements and BM-SC are the same as this network element.
  • MBSF network element is divided into two parts, MBSF-C and MBSF-U
  • the corresponding functions of BMSC are also divided into MBSF-C and MBSF-U accordingly, that is, the control plane function of BMSC is the same as that of MBSF-C.
  • the user plane function of BMSC is co-located with MBSF-U.
  • the MBSF network element and the BM-SC are used as an example for illustration. In actual deployment, the MBSF network element and the BM-SC network element can also be deployed separately. In this case below, the BMSC and the MBSF network element may have an interface to facilitate the communication between the BMSC and the MBSF network element.
  • the network architecture shown in FIG. 3 above may also include other possible devices or network elements, such as UDR network elements, HSS+UDM, NEF network elements, and the like.
  • HSS+UDM is used to realize the functions of HSS network element and UDM network element
  • HSS+UDM may also be referred to as UDM network element for short.
  • the NEF network element may be co-located with the MBSF network element, or may not be co-located with the MBSF network element.
  • the AS can communicate with the MBSF network element through the NEF network element, or the AS can directly communicate with the MBSF network element through the interface between the AS and the MBSF network element.
  • the AS can send the data of the first service in the eMBMS transmission mode in the 4G network, and send the data of the first service in the 5MBS transmission mode in the 5G network.
  • a possible flow is described below with reference to FIG. 4 .
  • FIG. 4 is a schematic flowchart of data transmission of a first service on a 4G network and a 5G network provided by an embodiment of the present application. As shown in FIG. 4 , the process may include:
  • the AS requests the MBSF network element to send the data of the first service in the eMBMS transmission mode in the 4G network, and to send the data of the first service in the 5MBS transmission mode in the 5G network.
  • the MBSF network element creates an MBMS bearer of the first service in the 4G network, and creates a multicast session of the first service in the 5G network.
  • creating the MBMS bearer of the first service in the 4G network may refer to establishing the MB2-U interface, establishing the interface from the MBSF network element to the MBMS-GW, and from the MBMS-GW to the eNB, and informing the eNB to establish the MBMS Air interface bearer.
  • Creating a multicast session of the first service in the 5G network may refer to establishing an interface between the AS and the MB-UPF network element.
  • the MBSF network element exists, the MB2-U interface between the AS and the MBSF network element is established, and the interface between the MBSF network element and the MB-UPF network element is established.
  • the AS sends the data of the first service in the eMBMS transmission mode in the 4G network, and sends the data of the first service in the 5MBS transmission mode in the 5G network.
  • the data of the first service is only sent to the MB-UPF network element. That is to say, if no terminal device joins the multicast session of the first service, the data will not continue to be sent down, that is, it will not be sent to the access network element or the anchor UPF network element of any PDU session.
  • the AS may send a request message to the MBSF network element to request The message is used to request to send the data of the first service in the eMBMS transmission mode in the 4G network and to send the data of the first service in the 5MBS transmission mode in the 5G network.
  • the MBSF network element can create an MBMS bearer in the 4G network, and then the AS can send the data of the first service in the eMBMS transmission mode in the 4G network; and, after receiving the request message, the MBSF network element, A multicast session can be created in the 5G network, and then the AS can send the data of the first service to the MB-UPF network element in a 5MBS transmission mode on the 5G network.
  • the AS may send a request message 1 to the MBSF network element, where the request message 1 is used to request to send the data of the first service in the eMBMS transmission mode in the 4G network; accordingly, the MBSF network element receives After the request message 1, the MBMS bearer can be created in the 4G network, and then the AS can send the data of the first service in the eMBMS transmission mode in the 4G network.
  • the AS can send a request message 2 to the MBSF network element, where the request message 2 is used to request to send the data of the first service in the 5MBS transmission mode in the 5G network; correspondingly, after receiving the request message 2, the MBSF network element can A multicast session is created in the network, and then the AS can send the data of the first service to the MB-UPF network element in a 5MBS transmission mode on the 5G network.
  • the AS can send a request message 1 to the BM-SC, and the request message 1 is used to request that the data of the first service be sent in the eMBMS transmission mode in the 4G network; and
  • the MBSF network element sends a request message 2, where the request message 2 is used to request to send the data of the first service in a 5MBS transmission mode in the 5G network.
  • the AS may send the data of the first service in the eMBMS transmission mode in the 4G network and send the data of the first service in the 5MBS transmission mode in the 5G network.
  • the above process may further include S404a and S405a, or S404b and S405b, or S404c and S405c.
  • the terminal device joins the multicast session of the first service.
  • the terminal device may request to join the multicast session of the first service, for example, the terminal device may request to join the multicast session of the first service through signaling of the PDU session.
  • a shared tunnel from the MB-UPF network element to the access network element can be established, and the access network element can configure the terminal equipment through the multicast session Radio resources for receiving data of the first service.
  • the transmission mode is a shared MBS transmission mode.
  • the radio resources configured by the network element of the access network for the terminal device may be the radio resources corresponding to the PTP mode, that is, the radio resources allocated only for the terminal device to receive the data of the first service, or the radio resources corresponding to the PTM mode, that is, the radio resources corresponding to the PTM mode. Radio resources allocated by a plurality of terminal devices (including the terminal device) for receiving the data of the first service.
  • the AS sends the data of the first service to the terminal device through the transmission path a, and correspondingly, the terminal device can receive the data of the first service through the transmission path a.
  • the transmission path a (that is, the path corresponding to the shared MBS transmission mode) may be: AS ⁇ MB-UPF ⁇ gNB ⁇ terminal device.
  • the terminal device joins the multicast session of the first service.
  • the terminal device may request to join the multicast session of the first service, for example, the terminal device may request to join the multicast session of the first service through signaling of the PDU session.
  • a tunnel from the MB-UPF to the PGW-U+UPF can be established, and the PGW-U+UPF can receive the first message from the MB-UPF network element.
  • the data of the service is mapped to the PDU session of the terminal device, and then sent to the terminal device through the PDU session.
  • the transmission mode is a separate MBS transmission mode.
  • the AS sends the data of the first service to the terminal device through the transmission path b, and correspondingly, the terminal device can receive the data of the first service through the transmission path b.
  • the transmission path b (that is, the transmission path corresponding to the independent MBS transmission mode) may be: AS ⁇ MB-UPF ⁇ PGW-U+UPF ⁇ gNB ⁇ terminal device.
  • the terminal device enters a service area that supports the transmission of the first service in the eMBMS transmission mode in the 4G network.
  • the AS sends the data of the first service to the terminal device through the transmission path c, and correspondingly, the terminal device can receive the data of the first service through the transmission path c.
  • the transmission path c (that is, the transmission path corresponding to the eMBMS transmission mode) may be: AS ⁇ MBSF network element ⁇ MBMS-GW ⁇ eNB ⁇ terminal device.
  • the network elements described in Figure 1, Figure 2 and Figure 3 can also be called entities or functional entities.
  • AMF network elements can also be called AMF entities or AMF functional entities.
  • SMF network elements May also be referred to as SMF entity or SMF functional entity.
  • the above-mentioned network elements may be either network elements in hardware devices, software functions running on dedicated hardware, or virtualized functions instantiated on a platform (eg, a cloud platform).
  • the foregoing network element may be implemented by one device, or may be implemented jointly by multiple devices, or may be a functional module in one device, which is not specifically limited in this embodiment of the present application.
  • the device for realizing the functions of the terminal equipment may be a terminal equipment, or It may be a device capable of supporting the terminal device to realize the function, such as a chip system or a combined device or component capable of realizing the function of the terminal device, and the device may be installed in the terminal device.
  • the chip system may be composed of chips, or may include chips and other discrete devices.
  • an embodiment of the present application provides a communication method for sending data of a first service to the terminal device after the terminal device moves from the second network to the first network or from the first network to the second network .
  • Information 1 involved in Embodiments 1 to 6 may be replaced by first information
  • Information 2 may be replaced by second information
  • Information 4 may be replaced by third information
  • Information 5 may be replaced by fourth information
  • information 6 can be replaced with fifth information
  • information 7 can be replaced with sixth information
  • information 8 can be replaced with seventh information
  • information 9 can be replaced with eighth information
  • information 10 can be replaced with ninth information.
  • the transmission path 1 involved in Embodiments 1 to 6 may be replaced with the first transmission path
  • the transmission path 4 may be replaced with the second transmission path.
  • the core network element 1 involved in the first embodiment to the sixth embodiment can be replaced with the first core network element
  • the core network element 2 can be replaced with the second core network element
  • the core network element 3 can be replaced with the third core network element.
  • the core network element, the core network element 4 can be replaced with the fourth core network element
  • the core network element 5 can be replaced with the fifth core network element
  • the core network element 6 can be replaced with the sixth core network element
  • the core network element 7 may be replaced with a seventh core network element.
  • the applicable scenarios of Embodiments 1 to 3 may be: when the terminal device receives the data of the first service in a 5MBS transmission mode in the 5G network, the terminal device moves from the 5G network to the 4G network.
  • the terminal device before the terminal device moves from the 5G network to the 4G network, the terminal device is in the connected state.
  • the terminal device moves from the 5G network to the 4G network, and can access the 4G network through the handover process, or can also access the 4G network through redirection.
  • the terminal device moves from the 5G network to the 4G network, if the target cell of the terminal device supports the transmission of the data of the first service through the multicast transmission mode of the 4G network (ie, the eMBMS transmission mode), it is not necessary to switch the first service to the 4G network.
  • the unicast transmission mode of the 4G network is used for transmission.
  • the terminal device can directly receive the data of the first service through the eMBMS transmission mode after accessing the target cell. If the target cell of the terminal device does not support the transmission of the data of the first service through the eMBMS transmission mode, in order to maintain the continuity of the first service, the data of the first service may be switched to the unicast transmission mode of the 4G network for transmission.
  • Embodiments 1 to 3 which are used to determine whether the target cell of the terminal device supports the transmission of the data of the first service through the multicast transmission mode of the 4G network, so that the terminal device can move from the 5G network to the 4G network when the terminal device is moved. Afterwards, the data of the first service is sent to the terminal device in a reasonable manner.
  • Embodiment 1 a possible implementation process of the communication method will be described by taking the network architecture shown in FIG. 3 as an example.
  • FIG. 5 is a schematic flowchart corresponding to the communication method provided in Embodiment 1 of the present application. As shown in Figure 5, the process may include:
  • the PGW-C+SMF acquires service area information of the first service, where the service area information is used to indicate a service area that supports transmission of the first service in a first transmission mode (ie, eMBMS transmission mode) in a 4G network.
  • a first transmission mode ie, eMBMS transmission mode
  • the service area information includes at least one of the following: an identifier of a PLMN corresponding to the service area; a TAI corresponding to the service area; and an identifier of a cell corresponding to the service area.
  • the core network element 1 may send the service area information of the first service to the PGW-C+SMF, and then the PGW-C+SMF may receive the service area information of the first service.
  • the core network element 1 may include any of the following: MBSF network elements, MB-SMF network elements, NEF network elements, PCF network elements, UDM network elements, and UDR network elements.
  • the MBSF network element/NEF network element may receive the play range information of the first service sent by the AS, and then determine the service area information of the first service according to the play range information of the first service. Further, for example, the MBSF network element/NEF network element may send the service area information of the first service to the PGW-C+SMF; for example, the MBSF network element/NEF network element may first send the service area information of the first service.
  • the MBSF network element/NEF network element may first send the service area information of the first service to the PCF network element, and then send the information to the PCF network element by the MBSF network element/NEF network element.
  • the PCF network element sends it to the PGW-C+SMF; for another example, the MBSF network element/NEF network element may save the service area information of the first service in the UDR network element/UDM network element, and then the UDR network element/UDM network element Send it to PGW-C+SMF; for another example, the MBSF network element/NEF network element can save the service area information of the first service in the UDR network element/UDM network element, and the MB-SMF network element can store the information from the UDR network element/UDM network element from the UDR network element/UDM network element. The element obtains the service area information of the first service, and then sends it to the PGW-C+SMF.
  • the PGW-C+SMF may request the core network element 1 for service area information of the first service after receiving the join request (for requesting to join the multicast session of the first service) sent by the terminal device, and then The service area information of the first service sent by the network element 1 of the core network may be received.
  • the terminal device may send the service area information of the first service to the PGW-C+SMF, and then the PGW-C+SMF may receive the service area information of the first service.
  • the terminal device may receive a service announcement sent by the AS or the MBSF network element, where the service announcement includes the service area information of the first service, and further, the terminal device may report to the PGW-C. +SMF sends the service area information of the first service.
  • the terminal device may send the service area information of the first service to the PGW-C+SMF when joining the multicast session of the first service.
  • the service area information of the first service and the join request may be Carrying in the same message, the message can be a PDU session establishment request message or a PDU session modification request message.
  • the terminal device may also send the service area information of the first service to the PGW-C+SMF after joining the multicast session of the first service.
  • the service area information of the first service may carry in the PDU Session Modification Request message.
  • the AMF network element sends the information of the target cell of the terminal device to the PGW-C+SMF; correspondingly, the PGW-C+SMF can receive the information of the target cell.
  • the information of the target cell may include a TAI corresponding to the target cell and/or an identifier of the target cell.
  • the AMF network element may obtain the information of the target cell first. For example, when a terminal device moves from a 5G network to a 4G network, the source access network element of the terminal device (ie, the gNB in the 5G network) can send a handover request to the AMF network element, and the handover request includes the information of the target cell. Furthermore, the AMF network element can acquire the information of the target cell from the handover request.
  • AMF network element may send the information of the target cell to the PGW-C+SMF, and two possible implementations are described below.
  • the AMF network element can actively send the information of the target cell to the PGW-C+SMF. For example, after the AMF network element obtains the information of the target cell, if it is determined that the terminal device has joined the multicast session of the first service, it can determine the first PDU session associated with the first service, and the first PDU session is the PDU of the terminal device. session, and send a session context request message to the PGW-C+SMF, where the session context request message may include information of the target cell, and the session context request message is used to request the context of the first PDU session. It should be noted that, in other possible embodiments, the AMF network element may not determine whether the terminal device has joined the multicast session of the first service, nor determine the PDU session associated with the first service. The PGW-C+SMF corresponding to each PDU session that needs to be switched sends the information of the target cell.
  • the AMF network element may determine the first PDU session associated with the first service.
  • the PGW-C+SMF can send the identifier of the multicast session of the first service to the AMF network element through the first PDU session.
  • the identifier of the multicast session may refer to the identifier corresponding to the transmission of the first service in the third transmission mode (that is, the 5MBS transmission mode); after the AMF network element receives the identifier of the multicast session of the first service, it can establish the first service and the The association relationship between the first PDU sessions, and then according to the association relationship, the first PDU session associated with the first service can be determined.
  • the AMF network element may obtain the single network slice selection assistance information (S-NSSAI) and/or the data network name (DNN) of the first service, and determine the information of the first service.
  • the PDU session corresponding to the S-NSSAI and/or the DNN is the first PDU session associated with the first service.
  • the AMF network element may acquire the S-NSSAI and/or DNN of the first service from the UDM network element.
  • the AMF network element after the AMF network element obtains the information of the target cell, it can unconditionally send the information of the target cell to the PGW-C+SMF; that is, as long as the AMF network element obtains the information of the target cell, The information of the target cell may be sent to the PGW-C+SMF.
  • the AMF network element after the AMF network element obtains the information of the target cell, it can also conditionally send the information of the target cell to the PGW-C+SMF; that is to say, after the AMF network element obtains the information of the target cell, it can determine whether the pre-defined information is satisfied.
  • the information of the target cell may be sent to the PGW-C+SMF, and if not, the information of the target cell may not be sent to the PGW-C+SMF.
  • the AMF network element can determine whether the first service supports transmission through the 4G network. If so, it can send the information of the target cell to the PGW-C+SMF. Then, the information of the target cell is sent to the PGW-C+SMF.
  • the AMF network element can determine whether the first service supports transmission through the 4G network. For example, the AMF network element can obtain the subscription data of the first service, and then determine whether the first service supports transmission through the 4G network according to the subscription data. to transmit.
  • the AMF network element can passively send the information of the target cell to the PGW-C+SMF.
  • the AMF network element may send the information of the target cell to the PGW-C+SMF based on the request or instruction of the PGW-C+SMF.
  • the AMF network element may send a session context request message to the PGW-C+SMF, where the session context request message is used to request the context of the first PDU session of the terminal device.
  • the session context request message does not include the information of the target cell.
  • the PGW-C+SMF can obtain the information of the target cell of the terminal device from the AMF network element.
  • the PGW-C+SMF can determine whether the first service supports transmission through the 4G network. If so, the information about the target cell of the terminal device can be obtained from the AMF network element. Then obtain the information of the target cell of the terminal equipment from the AMF network element.
  • the PGW-C+SMF may also acquire the service area information of the first service after receiving the information of the target cell, that is, S501 may be performed after S502.
  • the PGW-C+SMF judges whether the target cell is within the service area according to the information of the target cell, if the target cell is not within the service area, execute S504a and S505a, if the target cell is within the service area, execute S504b and S505b.
  • the PGW-C+SMF can determine whether the target cell is within the service area according to the information of the target cell and the service area information.
  • the information of the target cell includes the TAI corresponding to the target cell (for example, TAI-1), and the service area information includes the TAI corresponding to the service area (for example, including TAI-1, TAI-2, TAI-3). If the TAI includes the TAI corresponding to the target cell, it can be determined that the target cell is within the service area.
  • the PGW-C+SMF fails to obtain the information of the target cell from the AMF network element (for example, the AMF network element does not support sending the information of the target cell to the PGW-C+SMF), it can be considered that the target cell is not in service. within the area.
  • the PGW-C+SMF sends information 1, where the information 1 is used to establish a transmission path 1, and the transmission path 1 is used to send the data of the first service to the terminal device in the second transmission mode in the 4G network.
  • the transmission path 1 (that is, the transmission path corresponding to the second transmission mode) may be: AS ⁇ MB-UPF network element ⁇ PGW-U+UPF ⁇ SGW ⁇ eNB ⁇ terminal device.
  • the transmission path 1 includes a unicast bearer between the terminal device and the PGW-U+UPF, and the information 1 is used to establish the transmission path 1 may mean that the information 1 is used to establish the unicast bearer included in the transmission path 1.
  • the information 1 may include the context of the unicast bearer, such as the QoS information of the unicast bearer, the identifier of the unicast bearer, and the like.
  • the PGW-C+SMF can obtain the information 1.
  • the PGW-C+SMF can obtain the information of the multicast QoS flow of the first service, and then determine the information of the unicast QoS flow of the first service according to the information of the multicast QoS flow of the first service; further, the SMF network element
  • the unicast QoS flow of the first service can be mapped to the unicast bearer, and the identifier of the unicast bearer can be obtained (for example, the identifier of the unicast bearer can be obtained from the AMF network element), so that the information 1 can be obtained.
  • the PGW-C+SMF may directly map the multicast QoS flow of the first service to the unicast bearer, and obtain the identifier of the unicast bearer, thereby obtaining the information 1.
  • the embodiment of the present application does not limit the timing at which the PGW-C+SMF acquires the information 1.
  • the PGW-C+SMF may acquire the information 1 during the process of adding the terminal device to the multicast session of the first service. ;
  • the PGW-C+SMF may obtain information 1 after determining that the target cell is not in the service area.
  • sending the information 1 by the PGW-C+SMF may mean that the PGW-C+SMF sends the information 1 to the AMF network element.
  • the PGW-C+SMF sends a session context response message to the AMF network element, where the session context response message includes the context of the first PDU session, and the context of the first PDU session includes information 1 .
  • the AMF network element can send the information 1 to the MME in the 4G network in the handover process, and then the MME can establish a unicast bearer in the 4G network according to the information 1.
  • the PGW-C+SMF can also trigger the establishment of a slave The tunnel from the MB-UPF network element to the PGW-U+UPF, and notify the PGW-U+UPF to map the data of the first service to the above-mentioned unicast bearer when receiving the data of the first service from the MB-UPF network element sent to the end device.
  • the PGW-C+SMF may receive a session update request message (for example, receive a session update request message from the SGW or MME); after receiving the session update request message Afterwards, the PGW-C+SMF may notify the PGW-U+UPF to map the data of the first service to the above-mentioned unicast bearer and send it to the terminal device when receiving the data of the first service from the MB-UPF network element. If the tunnel between the MB-UPF network element and the PGW-U+UPF has not been established, the PGW-C+SMF can also trigger the establishment of the tunnel from the MB-UPF to the PGW-U+UPF.
  • a session update request message for example, receive a session update request message from the SGW or MME
  • the PGW-C+SMF may notify the PGW-U+UPF to map the data of the first service to the above-mentioned unicast bearer and send it to the terminal device when receiving the data of the first service from the MB
  • the AS can send the data of the first service to the terminal device through the transmission path 1; correspondingly, the terminal device receives the data of the first service through the transmission path 1.
  • the fact that the PGW-C+SMF does not send the information 1 may mean that the PGW-C+SMF may not send the information 1 to the AMF network element.
  • the PGW-C+SMF sends a session context response message to the AMF network element, where the session context response message includes the context of the first PDU session, and the context of the first PDU session does not include information 1. Since the AMF network element does not receive the information 1, the AMF network element may not send the information 1 to the MME in the 4G network during the handover process, and the MME may no longer establish a unicast bearer for the terminal device.
  • the AS can send the data of the first service to the terminal device through the transmission path 2; correspondingly, the terminal device receives the data of the first service through the transmission path 2.
  • the transmission path 2 (that is, the transmission path corresponding to the first transmission mode) may be: AS ⁇ MBSF network element ⁇ MBMS-GW ⁇ eNB ⁇ terminal device.
  • the information broadcast in the broadcast channel of the target cell may include the TMGI corresponding to the first service and the configuration information of the first service.
  • the terminal device can monitor the broadcast channel of the target cell according to the pre-acquired TMGI corresponding to the first service, and then can receive the data of the first service through transmission path 2 according to the configuration information of the first service.
  • the configuration information of the first service may be used to determine a resource bearing data of the first service.
  • the TMGI corresponding to the first service may be acquired by the terminal device from the AS in advance, or may also be acquired by the terminal device from the MBSF network element in advance, which is not specifically limited.
  • the PGW-C+SMF can release or delete resources in the 5G network for sending the data of the first service to the terminal device.
  • the PGW-C+SMF can delete the multicast information of the first service, for example, delete the identifier of the multicast session of the first service and the information of the multicast QoS flow, optionally, if there is a unicast corresponding to the multicast QoS flow
  • PGW-C+SMF can also delete information related to unicast QoS flows.
  • the PGW-C+SMF may also delete the session with the MB-SMF network element. If, before the terminal device switches to the 4G network, the terminal device receives the data of the first service through the separate MBS transmission mode in the third transmission mode, the PGW-C+SMF can also delete the configuration of the PGW-U+UPF, so that the PGW -U+UPF stops copying the data of the first service to the tunnel corresponding to the first PDU session for transmission; if the terminal device is the last terminal device that receives the data of the first service in a separate MBS transmission mode through PGW-U+UPF, Then the PGW-C+SMF can also notify the MB-SMF network element to delete the tunnel from the MB-UPF network element to the PGW-U+UPF.
  • the PGW-C+SMF can determine whether the target cell is in the service area according to the service area information of the first service and the target cell information of the terminal device, and then perform different processing according to whether the target cell is in the service area. For example, if the target cell is not in the service area, the PGW-C+SMF can send information 1, and then the AS can send the data of the first service to the terminal device in the second transmission mode on the 4G network. If the target cell is in the service area, then The PGW-C+SMF may not send the information 1, and then the AS may send the data of the first service to the terminal device in the first transmission mode (ie, the eMBMS transmission mode) on the 4G network.
  • the first transmission mode ie, the eMBMS transmission mode
  • the PGW-C+SMF may not send the information 1.
  • the PGW-C+SMF can also send information 1, and then the AS can send the data of the first service to the terminal device in the second transmission mode on the 4G network.
  • This application The embodiment may not limit the relevant implementation when the target cell is within the service area.
  • FIG. 6 is a schematic flowchart corresponding to the communication method provided by Embodiment 2 of the present application. As shown in Figure 6, the process can include:
  • the AMF network element obtains service area information of the first service, where the service area information is used to indicate the service area where the first service is transmitted in the first transmission mode (ie, eMBMS transmission mode) in the 4G network.
  • the service area information is used to indicate the service area where the first service is transmitted in the first transmission mode (ie, eMBMS transmission mode) in the 4G network.
  • the AMF network element may obtain the service area information of the first service in various ways.
  • the AMF network element may receive the service area information of the first service from the core network element 2.
  • the core network element 2 may include Any of the following: PGW-C+SMF, MBSF network element, MB-SMF network element, NEF network element, UDM network element, and UDR network element.
  • the MBSF network element/NEF network element may receive the play range information of the first service sent by the AS, and then determine the service area information of the first service according to the play range information of the first service. Further, for example, the MBSF network element/NEF network element may send the service area information of the first service to the AMF network element; for example, the MBSF network element/NEF network element may send the service area information of the first service to the PGW- C+SMF, and then the PGW-C+SMF sends it to the AMF network element; for another example, the MBSF network element/NEF network element can send the service area information of the first service to the MB-SMF network element, and then the MB-SMF network element Send to the AMF network element; for another example, the MBSF network element/NEF network element may save the service area information of the first service in the UDR network element/UDM network element, and then the UDR network element/UDM network element sends it to the AMF network element For another example, the MBSF
  • the AMF network element judges whether the target cell is in the service area according to the information of the target cell, if the target cell is not in the service area, execute S603a to S606a, if the target cell of the terminal equipment is in the service area, execute S603b to S605b, or S603c to S605c are performed.
  • the AMF network element may acquire the information of the target cell, and then determine whether the target cell is within the service area according to the information of the target cell and the service area information. For example, when a terminal device moves from a 5G network to a 4G network, the source access network element of the terminal device (ie, the gNB in the 5G network) can send a handover request to the AMF network element, and the handover request includes the information of the target cell. Furthermore, the AMF network element can acquire the information of the target cell from the handover request.
  • the AMF network element sends a session context request message to the PGW-C+SMF, where the session context request message includes information 2, which is used to indicate that the data of the first service is sent to the terminal device in the second transmission mode in the 4G network.
  • the AMF network element determines that the terminal device has joined the multicast session of the first service, it can determine the first PDU session associated with the first service.
  • the C+SMF sends a session context request message, and the session context request message is used to request the context of the first PDU session.
  • the implementation of the AMF network element determining the first PDU session associated with the first service may refer to the description in the first embodiment.
  • the information 2 is used to indicate that the data of the first service is sent to the terminal device in the second transmission mode in the 4G network, and can also be replaced with other possible descriptions, for example, the information 2 is used to indicate the terminal device.
  • the target cell is not in the service area, or the information 2 is used to indicate the acquisition of the information 1, which is not specifically limited.
  • the PGW-C+SMF receives the session context request message, and according to information 2, sends the context of the first PDU session to the AMF network element, where the context of the first PDU session includes information 1.
  • the AMF network element sends information 1, where the information 1 is used to establish a transmission path 1, and the transmission path 1 is used to send the data of the first service to the terminal device in the second transmission mode in the 4G network.
  • the transmission path 1 For the transmission path 1, reference may be made to the description in the first embodiment.
  • sending the information 1 by the AMF network element may mean that the AMF network element sends the information 1 to the MME in the 4G network in the handover process, and then the MME can establish the information included in the transmission path 1 in the 4G network according to the information 1.
  • Unicast bearer
  • the AS sends data of the first service to the terminal device through transmission path 1; correspondingly, the terminal device receives data of the first service through transmission path 1.
  • the AMF network element sends a session context request message to the PGW-C+SMF, the session context request message does not include information 2 or the session context request message includes information 3, and the information 3 is used to indicate that the first transmission mode (ie eMBMS transmission mode) to send the data of the first service to the terminal device.
  • the first transmission mode ie eMBMS transmission mode
  • the information 3 is used to indicate that the data of the first service is sent to the terminal device in the first transmission mode in the 4G network, and can also be replaced with other possible descriptions, for example, the information 3 is used to indicate the terminal device.
  • the target cell is in the service area, or the information 3 is used to indicate that the information 1 is not acquired, which is not specifically limited.
  • the PGW-C+SMF sends the context of the first PDU session to the AMF network element, and the context of the first PDU session does not include information 1; correspondingly, the AMF network element can receive the context of the first PDU session.
  • the AMF network element since the AMF network element has not received the message 1, the AMF network element may not send the message 1.
  • the AMF network element does not send the information 1, which may mean that the AMF does not send the information 1 to the MME in the 4G network in the handover process, and thus the MME can no longer establish a unicast bearer for the terminal device.
  • the PGW-C+SMF may release or delete the resources in the 5G network for sending the data of the first service to the terminal device, for details, please refer to the description in the first embodiment.
  • the AS sends the data of the first service to the terminal device through the transmission path 2; correspondingly, the terminal device receives the data of the first service through the transmission path 2.
  • the transmission path 2 that is, the transmission path corresponding to the first transmission mode
  • the session context request message sent to the PGW-C+SMF may carry information 2, and then the PGW-C+SMF can Send message 1 to the AMF network element; after receiving the message 1, the AMF network element can send the message 1.
  • the session context request message sent to the PGW-C+SMF may not carry information 2 or carry information 3, and then the PGW-C+SMF may not send the AMF network element Send message 1; since the AMF network element has not received the message 1, the AMF network element may not send the message 1.
  • the AMF network element may send a session context request message to the PGW-C+SMF, and upon receiving the session context request message, the PGW-C+SMF will send information 1 to the AMF network element; the AMF network element receives After the information 1 is reached, whether to send the information 1 can be determined according to whether the target cell is in the service area.
  • the AMF network element sends information 4 to the source access network element (ie, the gNB in the 5G network) of the terminal device, where the information 4 is used to redirect the terminal device to the target cell.
  • the source access network element ie, the gNB in the 5G network
  • the gNB redirects the terminal device to the target cell.
  • the gNB can notify the terminal device to access the target cell, and accordingly, the terminal device can access the 4G network through the target cell.
  • the MME requests the AMF network element for the context of the terminal device, and then the AMF network element can request the PGW- C+SMF sends a session context request message.
  • the session context request message may not carry information 2 or carry information 3, and then PGW-C+SMF may not send information 1 to the AMF network element, and the AMF network element may not send information 1 to the MME. , so that no unicast bearer can be established in the 4G network.
  • the PGW-C+SMF may release or delete the resources in the 5G network for sending the first service to the terminal device, for details, refer to the description in the first embodiment.
  • the AS sends the data of the first service to the terminal device through the transmission path 2; correspondingly, the terminal device receives the data of the first service through the transmission path 2.
  • the information broadcast in the broadcast channel of the target cell may include the TMGI corresponding to the first service and the configuration information of the first service.
  • the terminal device can monitor the broadcast channel of the target cell according to the pre-acquired TMGI corresponding to the first service, and then can receive data of the first service through transmission path 2 according to the configuration information of the first service.
  • the AMF network element can determine whether the target cell is in the service area according to the service area information of the first service and the information of the target cell of the terminal device, and then perform different processing according to whether the target cell is in the service area. For example, if the target cell is not in the service area, the AMF network element can send information 1, and then the AS can send the data of the first service to the terminal device in the second transmission mode on the 4G network. If the target cell is in the service area, the AMF network The element may not send the information 1, and then the AS may send the data of the first service to the terminal device in the first transmission mode (ie, the eMBMS transmission mode) on the 4G network.
  • the first transmission mode ie, the eMBMS transmission mode
  • Embodiment 3 a possible implementation process of the communication method will be described by taking the network architecture shown in FIG. 3 as an example.
  • FIG. 7 is a schematic flowchart corresponding to the communication method provided in Embodiment 3 of the present application. As shown in Figure 7, the process can include:
  • the source access network element of the terminal device acquires service area information of the first service, where the service area information is used to indicate that the first service is transmitted in the first transmission mode (that is, eMBMS transmission in the 4G network) mode) the service area in which the transmission takes place.
  • the gNB may obtain the service area information of the first service. Two possible implementations are described below.
  • the core network element 3 may send the service area information of the first service to the gNB, and then the gNB may receive the service area information of the first service.
  • the core network element 3 may include any one of the following: PGW-C+SMF, AMF network element, and MB-SMF network element.
  • the PGW-C+SMF or AMF network element may send the service area information of the first service to the gNB when requesting the gNB to add the terminal device to the multicast session of the first service.
  • the MB-SMF can send the service area information of the first service to the gNB when the gNB establishes the multicast session of the first service; specifically, the gNB receives the multicast session that adds the terminal device to the first service.
  • a request message can be sent to the MB-SMF to establish a multicast session of the first service, and then the MB-SMF can send the service area information of the first service to the gNB through a response message.
  • the implementation of the PGW-C+SMF, the AMF network element, or the MB-SMF network element acquiring the service area information of the first service may refer to the description in the first embodiment or the second embodiment.
  • the AMF may first trim the service area information of the first service, obtain the trimmed service area information, and use the trimmed service area information.
  • the information is sent to the gNB.
  • the tailored service area information may be used to indicate a first service area that supports transmission of the first service in the eMBMS transmission mode in the 4G network, and the first service area may be an area adjacent to the gNB in the service area. In this way, the size of the information sent to the gNB can be reduced, thereby saving transmission resources.
  • the terminal device may send the service area information of the first service to the gNB, and then the gNB may receive the service area information of the first service.
  • the terminal device may send a radio resource control (radio resource control, RRC) message to the gNB, where the RRC message includes service area information of the first service.
  • RRC radio resource control
  • the gNB judges whether the target cell of the terminal device is within the service area, and if the target cell is not within the service area, executes S703a to S704a; if the target cell is within the service area, executes S703b to S704b, or executes S703c to S704c.
  • the gNB sends information 5, where the information 5 is used to indicate that the data of the first service is sent to the terminal device in the second transmission mode in the 4G network, or the information 5 is used to indicate that radio resources are allocated on the 4G network for the first service.
  • the wireless resource is used to send the data of the first service to the terminal device in the second transmission mode in the 4G network, or the information 5 is used to instruct the switching of the first service to the 4G network (for example, it may refer to switching the first service in the switching process. business is switched to 4G network).
  • the gNB can send information 5 to the AMF network element (for example, carried in the handover request), and after receiving the information 5, the AMF network element can obtain the information 2 according to the information 5 (for the information 2, please refer to the above implementation. The description in Example 2), and send a session context request message to the PGW-C+SMF, where the session context request message carries information 2. Further, the PGW-C+SMF can send information 1 to the AMF network element. After receiving the information 1, the AMF network element can send the information 1 to the MME in the 4G network in the handover process, and then the MME can establish the unicast bearer included in the transmission path 1 in the 4G network according to the information 1.
  • the gNB can send information 5 to the PGW-C+SMF through the AMF network element (in this case, the AMF network element plays a forwarding role, and does not need to parse the information 5), for example, the information 5 can carry in the N2SM message.
  • the PGW-C+SMF can send the information 1 to the AMF network element according to the information 5.
  • the AMF network element can send the information 1 to the MME in the 4G network in the handover process, and then the MME can establish the unicast bearer included in the transmission path 1 in the 4G network according to the information 1.
  • the information 5 may include the identification and/or indication information of the multicast session of the first service (for example, the indication information may indicate the second transmission mode of the 4G network).
  • the information 5 may include indication information but not the identifier of the multicast session of the first service.
  • the AS sends the data of the first service to the terminal device through the transmission path 1; correspondingly, the terminal device receives the data of the first service through the transmission path 1.
  • the gNB sends information 6, where the information 6 is used to send the data of the first service to the terminal device in the first transmission mode (ie, the eMBMS transmission mode) in the 4G network, or the information 6 is used to indicate that the first service is not in the 4G network
  • the network allocates wireless resources, and the wireless resources are used to send the data of the first service to the terminal device in the second transmission mode in the 4G network, or the information 6 is used to indicate that the first service is not to be switched to the 4G network (for example, it may refer to The first service is not switched to the 4G network in the switching process).
  • the gNB can send the information 6 to the AMF network element (for example, it is carried in the handover request).
  • the AMF network element can obtain the information 3 according to the information 6, and send the information to the PGW-C+
  • the SMF sends a session context request message, and the session context request message carries the information 3, and the PGW-C+SMF may not send the information 1 to the AMF network element. Since the AMF network element does not receive the information 1, it may not send the information 1 to the MME in the 4G network in the handover process, and the MME may not establish the unicast bearer included in the transmission path 1 in the 4G network.
  • the gNB can send information 6 to the PGW-C+SMF through the AMF network element (in this case, the AMF network element plays a forwarding role and does not need to parse the information 6), for example, the information 6 can carry in the N2SM message.
  • the PGW-C+SMF may, according to the information 6, not send the information 1 to the AMF network element. Since the AMF network element does not receive the information 1, it may not send the information 1 to the MME in the 4G network in the handover process, and the MME may not establish the unicast bearer included in the transmission path 1 in the 4G network.
  • the information 6 may include the identification and/or indication information of the multicast session of the first service (for example, the indication information may indicate the first transmission mode of the 4G network).
  • the information 6 may include indication information, but not the identifier of the multicast session of the first service.
  • the PGW-C+SMF may also release or delete the resources in the 5G network for sending the data of the first service to the terminal device.
  • the PGW-C+SMF may also release or delete the resources in the 5G network for sending the data of the first service to the terminal device.
  • the AS sends the data of the first service to the terminal device through the transmission path 2; correspondingly, the terminal device receives the data of the first service through the transmission path 2.
  • the gNB redirects the terminal device to the target cell.
  • the AS sends the data of the first service to the terminal device through the transmission path 2; correspondingly, the terminal device receives the data of the first service through the transmission path 2.
  • the source access network network element of the terminal device can determine whether the target cell is in the service area according to the service area information of the first service and the information of the target cell of the terminal device, and then perform the operation according to whether the target cell is in the service area. different treatments. For example, if the target cell is not in the service area, the source access network element can send information 5, and then the AS can send the data of the first service to the terminal device in the second transmission mode on the 4G network. If the target cell is in the service area, Then the source access network element can redirect the terminal device to the target cell, or send information 6, and then the AS can send the data of the first service to the terminal device in the first transmission mode (ie eMBMS transmission mode) on the 4G network.
  • the first transmission mode ie eMBMS transmission mode
  • Embodiment 4 and Embodiment 5 may be: For example, in the network architecture (coexistence of 4G network and 5G network) shown in FIG. Before moving to the 5G network, the terminal device can be in the connected state, and then the terminal device can access the 5G network through the handover process; or, before the terminal device moves from the 4G network to the 5G network, the terminal device can be in the idle state, and then the terminal device It can be to access the 5G network from the idle state. For another example, in the network architecture shown in FIG. 2 , the terminal device may access the 5G network for the first time.
  • the terminal device After the terminal device accesses the 5G network, since the gNB will not broadcast the TMGI of the first service and the configuration information of the first service (the eNB in the 4G network can broadcast the TMGI of the first service and the configuration information of the first service), therefore, The terminal device needs to join the multicast session of the first service in order to obtain configuration information of the first service, and then receive data of the first service according to the configuration information of the first service.
  • the terminal device since there may be some PLMNs in the 5G network that do not support sending the data of the first service in the 5MBS transmission mode, the terminal device does not know whether the currently accessed PLMN supports sending the data of the first service in the 5MBS transmission mode, resulting in the terminal device The device cannot decide whether to join the multicast session of the first service.
  • Embodiment 4 and Embodiment 5 which are used to determine whether the PLMN currently accessed by the terminal device supports sending the data of the first service in the 5MBS transmission mode, so that after the terminal device accesses the 5G network, through a reasonable way to send the data of the first service to the terminal device.
  • Embodiment 4 a possible implementation process of the communication method will be described by taking the network architecture shown in FIG. 3 as an example. It should be noted that the fourth embodiment can also be applied to the network architecture shown in FIG. 2 .
  • FIG. 8 is a schematic flowchart corresponding to the communication method provided in Embodiment 4 of the present application. As shown in Figure 8, the process can include:
  • the terminal device obtains information 7, where the information 7 is used to indicate a network that supports sending data of the first service in a third transmission mode (ie, a 5MBS transmission mode).
  • a third transmission mode ie, a 5MBS transmission mode
  • the information 7 may include identifiers of one or more networks, and the one or more networks support sending the data of the first service in a 5MBS transmission manner.
  • the one or more networks may be one or more PLMNs in the 5G network, and the one or more PLMNs include the first PLMN.
  • the information 7 may also include the DNN and/or the S-NSSAI corresponding to each of the one or more networks.
  • the terminal device may acquire the information 7 in various manners. For example, the terminal device may receive a service announcement of the first service sent by the AS or the MBSF network element, and the service announcement includes the information 7 .
  • the terminal device accesses the first PLMN of the 5G network.
  • the terminal equipment accesses the first PLMN of the 5G network, which may include the following situations.
  • Scenario 1 for example, in the network architecture shown in Figure 3 (when the 4G network and the 5G network coexist), the terminal device moves from the 4G network to the 5G network, and before the terminal device moves from the 4G network to the 5G network, the terminal device can be in the connected state, and the terminal device may be the first PLMN that accesses the 5G network through the handover process; or, before the terminal device moves from the 4G network to the 5G network, the terminal device may be in an idle state, and then the terminal device may be connected from the idle state.
  • Scenario 2 for example, in the network architecture shown in FIG. 2 , the terminal device accesses the first PLMN of the 5G network for the first time.
  • the terminal device sends a join request to the network element (such as PGW-C+SMF) in the first PLMN according to the information 7, where the join request is used to request to join the multicast session of the first service, or the join request is used to request to join the multicast session of the first service.
  • the data of the first service is sent to the terminal device in a 5MBS transmission mode in the second network.
  • the terminal device may send a join request to the network element in the first PLMN through the first PDU session of the terminal device, the DNN and/or S-NSSAI corresponding to the first PDU session and the DNN and/or the DNN and/or the S-NSSAI corresponding to the first PLMN.
  • S-NSSAI is the same.
  • the terminal device may determine the first PDU session according to the DNN and/or S-NSSAI corresponding to the first PLMN.
  • the AS sends the data of the first service to the terminal device through the transmission path 3 (ie, the transmission path corresponding to the third transmission mode); correspondingly, the terminal device receives the data of the first service through the transmission path 3 .
  • the shared MBS transmission mode in the third transmission mode is used to send the data of the first service to the terminal device, and the corresponding transmission path 3 may be: AS ⁇ MB-UPF ⁇ gNB ⁇ Terminal equipment.
  • the gNB accessed by the terminal device does not support 5G MBS
  • the separate MBS transmission mode in the third transmission mode is used to send the data of the first service to the terminal device, and the corresponding transmission path 3 may be: AS ⁇ MB-UPF ⁇ PGW- U+UPF ⁇ gNB ⁇ terminal device.
  • the terminal device can determine whether the network accessed by the terminal device supports sending the data of the first service in the 5MBS transmission mode according to the information 7. If so, the terminal device can send a join request to join the multicast session of the first service. , if not, the terminal device may not send a join request, so that the terminal device can determine whether to send a join request through the above judgment after accessing the 5G network, so as to receive the data of the first service in a reasonable way.
  • Embodiment 5 a possible implementation process of the communication method will be described by taking the network architecture shown in FIG. 3 as an example. It should be noted that the fifth embodiment can also be applied to the network architecture shown in FIG. 2 .
  • FIG. 9 is a schematic flowchart corresponding to the communication method provided in Embodiment 5 of the present application. As shown in Figure 9, the process can include:
  • the MBSF network element or the AS sends a first subscription request to the core network element 4, where the first subscription request is used to request the core network element 4 to send a first notification message after the terminal device accesses the 5G network.
  • the first subscription request may include an identifier of the terminal device, and the identifier of the terminal device may be an IP address of the terminal device or a generic public subscription identifier GPSI.
  • the core network element 4 may be an AMF network element, a PGW-C+SMF or a PCF network element.
  • the core network element 4 may be an AMF network element, an SMF network element or a PCF network element.
  • the MBSF network element or the AS may send the first subscription request message to the core network network element 4 through the NEF network element.
  • the AS may send the first subscription request to the core network element 4 after determining that the terminal device needs to receive the data of the first service.
  • the terminal device may send a service request to the AS, where the service request is used to request to receive data of the first service, and then the AS may determine that the terminal device needs to receive data of the first service after receiving the service request.
  • the terminal device may indicate the capability information of the terminal device to the AS, that is, whether to support access to the 4G network and/or 5G network, and the AS may send the first subscription request based on the capability information of the terminal; for example, if the capability information of the terminal device If the terminal device supports access to the 5G network, the AS may send the first subscription request. If the capability information of the terminal device indicates that the terminal device does not support access to the 5G network, the AS may not send the first subscription request.
  • the terminal device may send the service request to the AS through the first session of the terminal device.
  • the first session may be a PDU session of the terminal device or a PDN connection of the terminal device.
  • the terminal device is connected to the 5G network.
  • the terminal device accessing the 5G network may include the following situations.
  • Scenario 1 for example, in the network architecture shown in Figure 3 (when the 4G network and the 5G network coexist), the terminal device moves from the 4G network to the 5G network, and before the terminal device moves from the 4G network to the 5G network, the terminal device can be in In the connected state, the terminal device can access the 5G network through the handover process; or, before the terminal device moves from the 4G network to the 5G network, the terminal device can be in the idle state, and then the terminal device can access the 5G network from the idle state.
  • Scenario 2 for example, in the network architecture shown in Figure 2, the terminal device accesses the 5G network for the first time.
  • S901 may be executed before S902, or S901 may also be executed after S902, which is not specifically limited.
  • the core network element 4 sends a first notification message to the MBSF network element or the AS, where the first notification message is used to notify the terminal device to access the 5G network; correspondingly, the MBSF network element or the AS may receive the first notification message.
  • the first notification message may include the identifier of the second PLMN.
  • S903 may be the response message of S901, that is, the AS terminal equipment is notified in the response message of the first subscription request that it has accessed the second PLMN of the 5G network.
  • the MBSF network element or the AS sends information 8 to the core network element 5, where the information 8 is used to indicate that the data of the first service is sent to the terminal device in the third transmission mode (5MBS transmission mode) in the 5G network.
  • the information 8 may include the identification of the multicast session of the first service.
  • the MBSF network element or the AS can determine whether the second PLMN supports sending the data of the first service in the 5MBS transmission mode according to the identifier of the second PLMN. If supported, the MBSF network element or AS can send information 8 to the core network element 5. After receiving the information 8, the core network element 5 can add the terminal device to the multicast session of the first service; if not, the MBSF The network element or the AS may not instruct the terminal device to join the multicast session of the first service.
  • the core network element 5 may be a PCF network element or an MB-SMF network element.
  • the AS may send the information 8 to the core network element 5 through the NEF network element.
  • the AS may send the information 8 to the core network element 5 through an application policy session or an application function session (ie, an AF session) corresponding to the PDU session associated with the first service.
  • the core network element 5 can notify the SMF network element (or PGW-C+SMF) corresponding to the PDU session associated with the first service to add the terminal device to the multicast of the first service. session.
  • the core network element 5 is a PCF network element.
  • the PCF network element can pass the PDU session.
  • the corresponding application policy session notifies the SMF network element corresponding to the PDU session to add the terminal device to the multicast session of the first service.
  • the information 8 may carry the information of the terminal device, and the core network element 5 may be a PCF network element or an SMF network element.
  • the information of the terminal device is the IP address of the terminal device.
  • the NEF network element can determine the PCF network element or SMF network element serving the PDU session corresponding to the IP address of the terminal device, and then can notify the The SMF network element served by the PDU session (notified directly or via the PCF network element) adds the terminal device to the multicast session of the first service.
  • the core network element 5 may send the identifier of the multicast session of the first service to the SMF network element.
  • the process of adding the terminal device to the multicast session of the first service by the SMF network element may refer to the prior art, and will not be repeated here.
  • the AS sends the data of the first service to the terminal device through the transmission path 3 ; correspondingly, the terminal device receives the data of the first service through the transmission path 3 .
  • the AS can determine whether the network accessed by the terminal device supports sending the data of the first service in the 5MBS transmission mode, and if so, the core network element can be instructed to add the terminal device to the multicast session of the first service. If not supported, the terminal device may not be instructed to join the multicast session of the first service, so that after the terminal device accesses the 5G network, the data of the first service can be sent to the terminal device in a reasonable manner.
  • Scenarios applicable to Embodiment 6 may include scenarios to which Embodiment 1 to Embodiment 3 are applicable. For details, refer to the above description.
  • Embodiment 6 a possible implementation process of the communication method will be described by taking the network architecture shown in FIG. 3 as an example.
  • FIG. 10 is a schematic flowchart corresponding to the communication method provided by Embodiment 6 of the present application. As shown in Figure 10, the process can include:
  • the MBSF network element or the AS sends a second subscription request to the core network element 6, where the second subscription request is used to request the core network element 6 to send a second notification message after the terminal device accesses the 4G network.
  • the second subscription request may include the identifier of the terminal device, and the identifier of the terminal device may be the IP address or GPSI of the terminal device.
  • the core network element 6 may be an MME network element, a PGW-C+SMF or a PCF network element.
  • the core network element 6 may be an MME network element or a PCF network element.
  • the AS may send a second subscription request to the core network element 6 after determining that the terminal device needs to receive data of the first service.
  • the terminal device may send a service request to the AS, where the service request is used to request to receive data of the first service, and then the AS may determine that the terminal device needs to receive data of the first service after receiving the service request.
  • the terminal device may indicate the capability information of the terminal device to the AS, that is, whether to support access to the 4G network and/or 5G network, and the AS may send the second subscription request based on the capability information of the terminal; for example, if the capability information of the terminal device If the terminal device supports access to the 4G network, the AS may send the second subscription request. If the capability information of the terminal device indicates that the terminal device does not support accessing the 4G network, the AS may not send the second subscription request.
  • the manner in which the terminal device sends the service request to the AS may refer to the description in the first embodiment.
  • the terminal device is connected to the 4G network.
  • a terminal device when a terminal device moves from a 5G network to a 4G network, it can access the 4G network through the attachment process or the tracking area update process, or it can also switch to the 4G network through the handover process.
  • S1001 may be executed before S1002, or S1001 may also be executed after S1002, which is not specifically limited.
  • the core network element 6 sends a second notification message to the MBSF network element or the AS, where the second notification message is used to notify the terminal device to access the 4G network; correspondingly, the MBSF network element or the AS may receive the second notification message.
  • S1003 may be a response message of S1001, that is, in the response message of the second subscription request, the AS is notified that the terminal device has accessed the 4G network.
  • the MBSF network element or the AS sends information 9 to the core network element 7, where the information 9 is used to establish a transmission path 4 (the transmission path corresponding to the fifth transmission mode), and the transmission path 4 is used to use the fifth transmission mode in the 4G network Send the data of the first service to the terminal device.
  • the destination address of the data packet is the IP address of the terminal device, and the transmission path 4 may be: AS ⁇ PGW-U network element ⁇ SGW ⁇ eNB ⁇ terminal device.
  • the second notification message may include information about cells in the 4G network accessed by the terminal device; further, after receiving the second notification message, the AS may The information of the cell, to determine whether the cell supports sending the data of the first service in eMBMS transmission mode (for example, determine whether the cell is in the service area that supports the transmission of the first service in eMBMS transmission mode), if not, send the data to the core
  • the network element 7 sends the information 9, and if supported, the information 9 may not be sent to the core network element 7.
  • the second subscription request may include information 10, where the information 10 is used to indicate that when the cell in the first network accessed by the terminal device does not support sending the data of the first service in the eMBMS transmission mode Send a second notification message.
  • the AS may send information 9 to the core network element 7 .
  • the information 10 may also include service area information that supports the transmission of the first service in the eMBMS transmission mode, so that the core network element 7 can determine whether the cell in the 4G network to which the terminal device accesses supports the transmission of the first service in the eMBMS transmission mode. business data.
  • the information 9 may include service information when the first service is sent in the fifth transmission mode, for example, the service information may include unicast filtering rules, and the information 9 may also include the QoS when the first service is sent in the fifth transmission mode. information.
  • the core network element 7 may be PGW-C+SMF, for example, the MBSF network element or the AS may send service information to the PGW-C+SMF through the NEF network element or the PCF network element.
  • the PCF network element Take the PCF network element as an example.
  • the PCF network element can determine the policy and charging control (PCC) rule according to the service information, and send the PCC rule to the PGW-C+SMF.
  • the PCC rule includes the unicast filtering rule.
  • the PGW-C+SMF can establish a unicast bearer according to the PCC rules, and send the unicast filtering rules to the PGW-U network element, and then the PGW-U network element receives the first
  • the data of the first service can be mapped to the unicast bearer according to the unicast filter rule, and sent to the terminal device through the unicast bearer.
  • the data of the first service can be sent to the terminal device through the default bearer first, so as to avoid data loss, but a small amount of data may not be guaranteed by QoS.
  • the AS sends the data of the first service to the terminal device through the transmission path 4 , and the destination address of the data packet is the IP address of the terminal device; correspondingly, the terminal device receives the data of the first service through the transmission path 4 .
  • the AS can know that the terminal equipment is connected to the 4G network according to the notification message of the core network element, and further, after the cell to which the terminal equipment is connected does not support sending the data of the first service in the eMBMS transmission mode, the AS can transmit the data of the first service through the fifth transmission method.
  • the transmission path corresponding to the mode sends the data of the first service to the terminal device.
  • the embodiment of the present application may not limit the message carrying the information; or, in Information 1 to Information 10 A message (or some) may itself be a message.
  • step numbers of the flowcharts described in Embodiments 1 to 6 are only an example of the execution flow, and do not constitute a restriction on the sequence of execution of the steps, and there is no timing dependency between the embodiments of the present application There is no strict order of execution between the steps of a relationship.
  • steps shown in each flowchart are steps that must be executed, and some steps may be added or deleted on the basis of each flowchart according to actual needs.
  • Embodiments 1 to 6 The above focuses on describing the differences between the different embodiments in Embodiments 1 to 6. Except for the other contents of the differences, mutual reference can be made between Embodiments 1 and 6; in addition, in the same embodiment , different implementations or different examples may also refer to each other.
  • Embodiments 1 to 6 may be implemented independently, or may also be implemented in combination.
  • Embodiment 1, Embodiment 2 or Embodiment 3 may be implemented in combination with Embodiment 4.
  • Embodiment 1, Embodiment 2 or Embodiment 1 may be used.
  • the solution in the third embodiment when the terminal device moves from the 4G network to the 5G network, the solution in the fourth embodiment can be adopted.
  • the fifth embodiment can be implemented in combination with the sixth embodiment. In this case, when the terminal device moves from the 5G network to the 4G network, the solution in the sixth embodiment can be adopted.
  • the solution in Embodiment 5 may be adopted; in addition, in this case, the first subscription request and the second subscription request may be carried in the same message or in different messages, which is not specifically limited.
  • the core network element, the access network element, the terminal device or the application server may include corresponding hardware structures and/or software modules for performing each function.
  • the embodiments of the present application can be implemented in hardware or a combination of hardware and computer software. Whether a function is performed by hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of this application.
  • the core network element, the access network element, the terminal device, or the application server may be divided into functional units according to the foregoing method examples.
  • each functional unit may be divided corresponding to each function, or two or two functional units may be divided. More than one function is integrated in one unit.
  • the above-mentioned integrated units may be implemented in the form of hardware, or may be implemented in the form of software functional units.
  • FIG. 11 shows a possible exemplary block diagram of the apparatus involved in the embodiment of the present application.
  • the apparatus 1100 may include: a processing unit 1102 and a communication unit 1103 .
  • the processing unit 1102 is used to control and manage the actions of the device 1100 .
  • the communication unit 1103 is used to support the communication between the apparatus 1100 and other devices.
  • the communication unit 1103 is also referred to as a transceiving unit, and may include a receiving unit and/or a sending unit, which are respectively configured to perform receiving and sending operations.
  • the apparatus 1100 may further include a storage unit 1101 for storing program codes and/or data of the apparatus 1100 .
  • the apparatus 1100 may be the first terminal device in the foregoing embodiment, or may also be a chip provided in the first terminal device.
  • the processing unit 1102 may support the apparatus 1100 to perform the actions of the first terminal device in each method example above. Alternatively, the processing unit 1102 mainly performs the internal actions of the first terminal device in the method example, and the communication unit 1103 may support the communication between the apparatus 1100 and other devices.
  • the processing unit 1102 is configured to: acquire service area information of the first service, where the service area information is used to indicate that the first service is supported in the first network in the first transmission mode The service area for transmission; the communication unit 1103 is configured to: if the target cell of the terminal device is not in the service area, send first information, where the first information is used to establish a first transmission path, the first The transmission path is used to send the data of the first service to the terminal device in a second transmission manner in the first network; or, if the target cell is within the service area, do not send the first service information; wherein the target cell is located in the first network.
  • the service area information includes at least one of the following: an identifier of the public land mobile network PLMN corresponding to the service area; an identifier TAI of the tracking area corresponding to the service area; the service area corresponding to the identity of the cell.
  • the apparatus 1100 may be a session management network element or a chip provided in the session management network element.
  • the communication unit 1103 is further configured to: receive the service area information from a first core network element, where the first core network element includes any one of the following: a multicast service network element, Multicast session management network element, network opening function network element, policy control network element, unified data storage network element, unified data management network element; or, receiving the service area information from the terminal device.
  • the first core network element includes any one of the following: a multicast service network element, Multicast session management network element, network opening function network element, policy control network element, unified data storage network element, unified data management network element; or, receiving the service area information from the terminal device.
  • the communication unit 1103 is specifically configured to: receive a first message from the terminal device, where the first message includes the service area information; wherein the first message is a PDU session establishment request message or PDU Session Modification Request message.
  • the first message further includes a join request, where the join request is used to request to send the data of the first service to the terminal device in a third transmission manner in the second network .
  • the processing unit 1102 is further configured to: acquire the information of the target cell; and determine whether the target cell is within the service area according to the information of the target cell.
  • the information of the target cell includes the TAI corresponding to the target cell and/or the identifier of the target cell.
  • the communication unit 1103 is further configured to: receive the information of the target cell from the mobility management network element.
  • the information of the target cell is carried in a session context request message from the mobility management network element, and the session context request message is used to request the terminal device for the first PDU session context, the first PDU session is associated with the first service.
  • the processing unit 1102 is further configured to: if the session context request message does not carry the information of the target cell, determine that the target cell is not in the service area.
  • the communication unit 1103 is further configured to: receive a session context request message from the mobility management network element, where the session context request message is used to request the context of the first PDU session of the terminal device, so the first PDU session is associated with the first service; according to the session context request message, send the context of the first PDU session to the mobility management network element, where the context of the first PDU session includes the first information.
  • the communication unit 1103 is further configured to: receive a session context request message from the mobility management network element, where the session context request message is used to request the context of the first PDU session of the terminal device , the first PDU session is associated with the first service; according to the session context request message, the context of the first PDU session is sent to the mobility management network element, and the context of the first PDU session is not including the first information.
  • the processing unit 1102 is further configured to: release the second network used for sending the first message to the terminal device business resources.
  • the apparatus 1100 may be a mobility management network element or a chip provided in the mobility management network element.
  • the communication unit 1103 is further configured to: receive the service area information from a second core network element, where the second core network element includes any one of the following: a session management NEs for broadcast services, NEs for multicast session management, NEs for network open functions, NEs for unified data storage, and NEs for unified data management.
  • the second core network element includes any one of the following: a session management NEs for broadcast services, NEs for multicast session management, NEs for network open functions, NEs for unified data storage, and NEs for unified data management.
  • the processing unit 1102 is further configured to: acquire the information of the target cell; and determine whether the target cell is within the service area according to the information of the target cell.
  • the information of the target cell includes the TAI corresponding to the target cell and/or the identifier of the target cell.
  • the communication unit 1103 is further configured to: receive information about the target cell from a source access network element of the terminal device, where the source access network element is located in the second network middle.
  • the communication unit 1103 is further configured to: receive the first information from the session management network element.
  • the communication unit 1103 is further configured to: send a second message to the session management network element, where the second message is used to acquire the first information.
  • the second message includes second information, and the second information is used to indicate that the first network is sent to the terminal device in the second transmission manner. business data.
  • the second message is a session context request message
  • the session context request message is used to request the context of the first PDU session of the terminal device, and the first PDU session is related to the first PDU session. a business association.
  • the processing unit 1102 is further configured to: determine the first PDU session associated with the first service.
  • the processing unit 1102 is specifically configured to: determine, according to the S-NSSAI and/or DNN of the first service, that the PDU session corresponding to the S-NSSAI and/or DNN is a PDU session corresponding to the first service. the first PDU session associated with the service; or, receiving the identifier of the first service from the session management network element through the first PDU session, and establishing the association between the first service and the first PDU session relationship; according to the association relationship, determine the first PDU session associated with the first service.
  • the communication unit 1103 is further configured to: send third information to the source access network element of the terminal device, the third information for redirecting the terminal device to the target cell, and the source access network element is located in the second network.
  • each unit in the above apparatus can be realized in the form of software calling through the processing element; also can all be realized in the form of hardware; some units can also be realized in the form of software calling through the processing element, and some units can be realized in the form of hardware.
  • each unit can be a separately established processing element, or can be integrated in a certain chip of the device to be implemented, and can also be stored in the memory in the form of a program, which can be called by a certain processing element of the device and execute the unit's processing. Function.
  • each operation of the above method or each of the above units may be implemented by an integrated logic circuit of hardware in the processor element or implemented in the form of software being invoked by the processing element.
  • a unit in any of the above apparatuses may be one or more integrated circuits configured to implement the above methods, eg, one or more application specific integrated circuits (ASICs), or, one or more Multiple microprocessors (digital singnal processors, DSPs), or, one or more field programmable gate arrays (FPGAs), or a combination of at least two of these integrated circuit forms.
  • ASICs application specific integrated circuits
  • DSPs digital singnal processors
  • FPGAs field programmable gate arrays
  • a unit in the apparatus can be implemented in the form of a processing element scheduler
  • the processing element can be a processor, such as a general-purpose central processing unit (CPU), or other processors that can invoke programs.
  • these units can be integrated together and implemented in the form of a system-on-a-chip (SOC).
  • SOC system-on-a-chip
  • the above unit for receiving is an interface circuit of the device for receiving signals from other devices.
  • the receiving unit is an interface circuit used by the chip to receive signals from other chips or devices.
  • the above unit for sending is an interface circuit of the device for sending signals to other devices.
  • the sending unit is an interface circuit used by the chip to send signals to other chips or devices.
  • FIG. 12 it is a schematic structural diagram of a network element of a core network according to an embodiment of the present application. It may be a session management network element (such as PGW-C+SMF) or a mobility management network element (such as an AMF network element) in the above embodiment, which is used to implement the session management network element or the mobility management network element in the above embodiment. operation.
  • a session management network element such as PGW-C+SMF
  • a mobility management network element such as an AMF network element
  • the core network element 1200 may include a processor 1201 , a memory 1202 and an interface circuit 1203 .
  • the processor 1201 can be used to process the communication protocol and communication data, and to control the communication device.
  • the memory 1202 may be used to store programs and data, and the processor 1201 may execute the method performed by the core network element in the embodiment of the present application based on the program.
  • the interface circuit 1203 can be used for the core network element 1200 to communicate with other devices, and the communication can be wired communication or wireless communication, and the interface circuit can be, for example, a service-oriented communication interface.
  • the above memory 1202 may also be externally connected to the core network element 1200 .
  • the core network element 1200 may include an interface circuit 1203 and a processor 1201 .
  • the above interface circuit 1203 may also be externally connected to the core network element 1200 .
  • the core network element 1200 may include a memory 1202 and a processor 1201 .
  • the communication device 1200 may include a processor 1201 .
  • the core network element shown in FIG. 12 can implement each process involving the core network element in the foregoing method embodiments.
  • the operations and/or functions of each module in the network element of the core network shown in FIG. 12 are respectively to implement the corresponding processes in the foregoing method embodiments.
  • the access network element 130 may include one or more distributed units (DUs) 1301 and one or more centralized units (CUs) 1302 .
  • the DU 1301 may include at least one antenna 13011, at least one radio frequency unit 13012, at least one processor 13013 and at least one memory 13014.
  • the DU 1301 part is mainly used for the transmission and reception of radio frequency signals, the conversion of radio frequency signals and baseband signals, and part of baseband processing.
  • the CU 1302 may include at least one processor 13022 and at least one memory 13021 .
  • the part of the CU 1302 is mainly used to perform baseband processing and control network elements of the access network.
  • the DU 1301 and the CU 1302 may be physically set together, or may be physically separated, that is, a distributed base station.
  • the CU 1302 is the control center of the access network element, which can also be called a processing unit, and is mainly used to complete the baseband processing function.
  • the CU 1302 may be used to control the access network element to perform the operation flow of the access network element in the foregoing method embodiments.
  • the access network element 130 may include one or more radio frequency units, one or more DUs, and one or more CUs.
  • the DU may include at least one processor 13013 and at least one memory 13014
  • the radio unit may include at least one antenna 13011 and at least one radio frequency unit 13012
  • the CU may include at least one processor 13022 and at least one memory 13021 .
  • the CU1302 may be composed of one or more boards, and the multiple boards may jointly support a wireless access network (such as a 5G network) with a single access indication, or may respectively support wireless access systems of different access standards.
  • Access network such as LTE network, 5G network or other network.
  • the memory 13021 and the processor 13022 may serve one or more single boards. That is to say, the memory and processor can be provided separately on each single board. It can also be that multiple boards share the same memory and processor. In addition, necessary circuits may also be provided on each single board.
  • the DU1301 can be composed of one or more single boards.
  • Multiple single boards can jointly support a wireless access network (such as a 5G network) with a single access indication, or can support a wireless access network with different access standards (such as a 5G network). LTE network, 5G network or other network).
  • the memory 13014 and processor 13013 may serve one or more single boards. That is to say, the memory and processor can be provided separately on each single board. It can also be that multiple boards share the same memory and processor. In addition, necessary circuits may also be provided on each single board.
  • the access network element shown in FIG. 13 can implement each process involving the access network element in the foregoing method embodiments.
  • the operations and/or functions of each module of the network element of the access network shown in FIG. 13 are respectively to implement the corresponding processes in the foregoing method embodiments.
  • the terminal device includes: an antenna 1410 , a radio frequency part 1420 , and a signal processing part 1430 .
  • the antenna 1410 is connected to the radio frequency part 1420 .
  • the radio frequency part 1420 receives the information sent by the network device through the antenna 1410, and sends the information sent by the network device to the signal processing part 1430 for processing.
  • the signal processing part 1430 processes the information of the terminal equipment and sends it to the radio frequency part 1420
  • the radio frequency part 1420 processes the information of the terminal equipment and sends it to the network equipment through the antenna 1410.
  • the signal processing part 1430 may include a modulation and demodulation subsystem, which is used to implement the processing of each communication protocol layer of the data; it can also include a central processing subsystem, which is used to implement the processing of the terminal device operating system and the application layer; in addition, it can also Including other subsystems, such as multimedia subsystem, peripheral subsystem, etc., wherein the multimedia subsystem is used to realize the control of the terminal equipment camera, screen display, etc., and the peripheral subsystem is used to realize the connection with other devices.
  • the modem subsystem can be a separate chip.
  • the modem subsystem may include one or more processing elements 1431, including, for example, a host CPU and other integrated circuits.
  • the modulation and demodulation subsystem may also include a storage element 1432 and an interface circuit 1433 .
  • the storage element 1432 is used to store data and programs, but the program used to execute the method performed by the terminal device in the above method may not be stored in the storage element 1432, but in a memory outside the modulation and demodulation subsystem, When used, the modem subsystem is loaded for use.
  • Interface circuit 1433 is used to communicate with other subsystems.
  • the modulation and demodulation subsystem can be implemented by a chip, the chip includes at least one processing element and an interface circuit, wherein the processing element is used to execute each step of any one of the methods performed by the above terminal equipment, and the interface circuit is used to communicate with other devices.
  • the unit for the terminal device to implement each step in the above method may be implemented in the form of a processing element scheduler.
  • an apparatus for a terminal device includes a processing element and a storage element, and the processing element calls the program stored in the storage element to Execute the method executed by the terminal device in the above method embodiments.
  • the storage element may be a storage element on the same chip as the processing element, ie, an on-chip storage element.
  • the program for executing the method performed by the terminal device in the above method may be in a storage element on a different chip from the processing element, that is, an off-chip storage element.
  • the processing element calls or loads the program from the off-chip storage element to the on-chip storage element, so as to call and execute the method performed by the terminal device in the above method embodiments.
  • the unit for the terminal device to implement each step in the above method may be configured as one or more processing elements, and these processing elements are provided on the modulation and demodulation subsystem, and the processing element here may be an integrated circuit, For example: one or more ASICs, or, one or more DSPs, or, one or more FPGAs, or a combination of these types of integrated circuits. These integrated circuits can be integrated together to form chips.
  • the units of the terminal device implementing each step in the above method may be integrated together and implemented in the form of an SOC, and the SOC chip is used to implement the above method.
  • At least one processing element and a storage element may be integrated in the chip, and the method executed by the above terminal device may be implemented in the form of a program stored in the storage element being invoked by the processing element; or, at least one integrated circuit may be integrated in the chip to implement the above terminal.
  • the above apparatus for a terminal device may include at least one processing element and an interface circuit, where the at least one processing element is configured to execute any method performed by the terminal device provided in the above method embodiments.
  • the processing element can execute part or all of the steps performed by the terminal device in the first way: by calling the program stored in the storage element; or in the second way: by combining the instructions with the integrated logic circuit of the hardware in the processor element Part or all of the steps performed by the terminal device may be performed in the manner of the first method; of course, some or all of the steps performed by the terminal device may also be performed in combination with the first manner and the second manner.
  • the processing element here is the same as the above description, which can be implemented by a processor, and the function of the processing element can be the same as that of the processing unit described in FIG. 11 .
  • the processing element may be a general-purpose processor, such as a CPU, or may be one or more integrated circuits configured to implement the above methods, such as: one or more ASICs, or, one or more microprocessors, DSPs , or, one or more FPGAs, etc., or a combination of at least two of these integrated circuit forms.
  • the storage element may be implemented by a memory, and the function of the storage element may be the same as that of the storage unit described in FIG. 11 .
  • the storage element may be implemented by a memory, and the function of the storage element may be the same as that of the storage unit described in FIG. 11 .
  • the storage element can be one memory or a collective term for multiple memories.
  • the terminal device shown in FIG. 14 can implement each process involving the terminal device in the foregoing method embodiments.
  • the operations and/or functions of each module in the terminal device shown in FIG. 14 are respectively to implement the corresponding processes in the foregoing method embodiments.
  • FIG. 15 a schematic structural diagram of an application server provided by an embodiment of the present application is used to implement the operations of the application server in the above embodiment.
  • the application server 1500 may include a processor 1501 , a memory 1502 and an interface circuit 1503 .
  • the processor 1501 can be used to process the communication protocol and communication data, and to control the communication device.
  • the memory 1502 may be used to store programs and data, and the processor 1501 may execute the method executed by the application server in this embodiment of the present application based on the program.
  • the interface circuit 1503 can be used for the application server 1500 to communicate with other devices, and the communication can be wired communication or wireless communication, and the interface circuit can be, for example, a service-oriented communication interface.
  • the above memory 1502 may also be externally connected to the application server 1500 , in which case the application server 1500 may include an interface circuit 1503 and a processor 1501 .
  • the above interface circuit 1503 may also be externally connected to the application server 1500 .
  • the application server 1500 may include a memory 1502 and a processor 1501 .
  • the communication device 1500 may include a processor 1501 .
  • the application server shown in FIG. 15 can implement each process involving the application server in the foregoing method embodiments.
  • the operations and/or functions of each module in the application server shown in FIG. 15 are respectively to implement the corresponding processes in the foregoing method embodiments.
  • system and “network” in the embodiments of the present application may be used interchangeably.
  • At least one means one or more, and “plurality” means two or more.
  • And/or which describes the association relationship of the associated objects, means that there can be three kinds of relationships, for example, A and/or B, which can mean: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A, B can be singular or plural.
  • the character “/” generally indicates that the associated objects are an “or” relationship.
  • At least one item(s) below” or similar expressions thereof refer to any combination of these items, including any combination of single item(s) or plural items(s).
  • At least one of A, B and C includes A, B, C, AB, AC, BC or ABC.
  • ordinal numbers such as “first” and “second” mentioned in the embodiments of the present application are used to distinguish multiple objects, and are not used to limit the order, sequence, priority or importance of multiple objects degree.
  • the embodiments of the present application may be provided as a method, a system, or a computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.
  • computer-usable storage media including, but not limited to, disk storage, CD-ROM, optical storage, etc.
  • These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory result in an article of manufacture comprising instruction means, the instructions
  • the apparatus implements the functions specified in the flow or flow of the flowcharts and/or the block or blocks of the block diagrams.

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Abstract

本申请涉及通信技术领域，公开了一种通信方法及装置。其中方法包括：第一通信装置获取第一业务的服务区域信息，服务区域信息用于指示支持第一业务在第一网络中以第一传输方式进行传输的服务区域；若终端设备的目标小区不在服务区域内，则发送第一信息，第一信息用于建立第一传输路径，第一传输路径用于在第一网络中以第二传输方式向终端设备发送第一业务的数据；或者，若目标小区在服务区域内，则不发送第一信息。采用上述方法，第一通信装置可以根据第一业务的服务区域信息，确定目标小区是否在服务区域内，进而根据目标小区是否在服务区域内进行不同的处理，从而便于通过合理的方式向终端设备发送第一业务的数据。

Description

一种通信方法及装置 技术领域
本申请涉及无线通信技术领域，特别涉及一种通信方法及装置。
背景技术
随着移动互联网的发展，组播/广播业务被广泛应用，例如应用于高清视频、自动驾驶、物联网设备和公共安全预警等领域。
为满足组播/广播业务的传输需求，第4代(the 4th generation，4G)网络中引入了一种多播传输方式，即演进的多媒体广播组播服务(evolved multimedia broadcast multicast service，eMBMS)传输方式。此种情形下，以第一业务为例，第一业务可以为组播/广播业务，在4G网络中，可以通过eMBMS传输方式来传输第一业务的数据。第5代(the 5th generation，5G)网络中也引入了一种多播传输方式，即组播广播服务(multicast broadcast service，MBS)传输方式。此种情形下，仍以第一业务为例，在5G网络中，可以通过5G MBS传输方式来传输第一业务的数据。
然而，在4G网络和5G网络共存的场景中，当终端设备由5G网络移动至4G网络或者由4G网络移动至5G网络后，如何向终端设备发送第一业务的数据，仍需进一步的研究。
发明内容
本申请提供了一种通信方法及装置，用于实现当终端设备由第二网络移动至第一网络或者由第一网络移动至第二网络后，向终端设备发送第一业务的数据。
第一方面，本申请实施例提供一种通信方法，该方法应用于终端设备由第二网络移动至第一网络，该方法用于实现核心网网元侧的功能，例如该方法可以应用于会话管理网元或者会话管理网元中的芯片，本申请实施例不限该方法的具体的执行主体。以该方法应用于会话管理网元为例，会话管理网元获取第一业务的服务区域信息，所述服务区域信息用于指示支持所述第一业务在所述第一网络中以第一传输方式进行传输的服务区域；若所述终端设备的目标小区不在所述服务区域内，则发送第一信息，所述第一信息用于建立第一传输路径，所述第一传输路径用于在所述第一网络中以第二传输方式向所述终端设备发送所述第一业务的数据；或者，若所述目标小区在所述服务区域内，则不发送所述第一信息；其中，所述目标小区位于所述第一网络中。
采用上述方法，会话管理网元可以根据第一业务的服务区域信息，确定目标小区是否在服务区域内，进而根据目标小区是否在服务区域内进行不同的处理，从而便于通过合理的方式向终端设备发送第一业务的数据。比如若目标小区不在服务区域内，则可以发送信息1，进而AS可以在第一网络以第二传输方式向终端设备发送第一业务的数据，若目标小区在服务区域内，则可以不发送信息1，进而AS可以在第一网络以第一传输方式(即eMBMS传输方式)向终端设备发送第一业务的数据。
在一种可能的设计中，所述服务区域信息包括以下至少一项：所述服务区域对应的公共陆地移动网络PLMN的标识；所述服务区域对应的跟踪区的标识TAI；所述服务区域对应的小区的标识。
在一种可能的设计中，所述获取第一业务的服务区域信息，包括：接收来自第一核心网网元的所述服务区域信息，所述第一核心网网元包括以下任一项：多播业务网元、多播会话管理网元、网络开放功能网元、策略控制网元、统一数据存储网元、统一数据管理网元；或者，接收来自所述终端设备的所述服务区域信息。
在一种可能的设计中，所述接收来自所述终端设备的所述服务区域信息，包括：接收来自所述终端设备的第一消息，所述第一消息包括所述服务区域信息；其中，所述第一消息为PDU会话建立请求消息或PDU会话修改请求消息。
在一种可能的设计中，所述第一消息还包括加入请求，所述加入请求用于请求在所述第二网络中以第三传输方式向所述终端设备发送所述第一业务的数据。
在一种可能的设计中，所述方法还包括：获取所述目标小区的信息；根据所述目标小区的信息，确定所述目标小区是否在所述服务区域内。
在一种可能的设计中，所述目标小区的信息包括所述目标小区对应的TAI和/或所述目标小区的标识。
在一种可能的设计中，获取所述目标小区的信息，包括：接收来自移动性管理网元的所述目标小区的信息。
在一种可能的设计中，所述目标小区的信息携带在来自所述移动性管理网元的会话上下文请求消息中，所述会话上下文请求消息用于请求所述终端设备的第一PDU会话的上下文，所述第一PDU会话与所述第一业务关联。
在一种可能的设计中，所述方法还包括：若所述会话上下文请求消息中未携带所述目标小区的信息，则确定所述目标小区不在所述服务区域内。
在一种可能的设计中，所述发送第一信息，包括：接收来自移动性管理网元的会话上下文请求消息，所述会话上下文请求消息用于请求所述终端设备的第一PDU会话的上下文，所述第一PDU会话与所述第一业务关联；根据所述会话上下文请求消息，向所述移动性管理网元发送所述第一PDU会话的上下文，所述第一PDU会话的上下文包括所述第一信息。
在一种可能的设计中，所述不发送上下文信息，包括：接收来自所述移动性管理网元的会话上下文请求消息，所述会话上下文请求消息用于请求所述终端设备的第一PDU会话的上下文，所述第一PDU会话与所述第一业务关联；根据所述会话上下文请求消息，向所述移动性管理网元发送所述第一PDU会话的上下文，所述第一PDU会话的上下文不包括所述第一信息。
在一种可能的设计中，若所述终端设备的目标小区在所述服务区域内，则所述方法还包括：释放所述第二网络中用于向所述终端设备发送所述第一业务的资源。
第二方面，本申请实施例提供一种通信方法，该方法应用于终端设备由第二网络移动至第一网络，该方法用于实现核心网网元侧的功能，例如该方法可以应用于移动性管理网元或者移动性管理网元中的芯片，本申请实施例不限该方法的具体的执行主体。以该方法应用于移动性管理网元为例，移动性管理网元获取第一业务的服务区域信息，所述服务区域信息用于指示支持所述第一业务在所述第一网络中以第一传输方式进行传输的服务区域；若所述终端设备的目标小区不在所述服务区域内，则发送第一信息，所述第一信息用于建立第一传输路径，所述第一传输路径用于在所述第一网络中以第二传输方式向所述终端设备发送所述第一业务的数据；或者，若所述目标小区在所述服务区域内，则不发送所述上下文信息；其中，所述目标小区位于所述第一网络中。
采用上述方法，移动性管理网元可以根据第一业务的服务区域信息，确定目标小区是否在服务区域内，进而根据目标小区是否在服务区域内进行不同的处理，从而便于通过合理的方式向终端设备发送第一业务的数据。比如若目标小区不在服务区域内，则可以发送信息1，进而AS可以在第一网络以第二传输方式向终端设备发送第一业务的数据，若目标小区在服务区域内，则可以不发送信息1，进而AS可以在第一网络以第一传输方式(即eMBMS传输方式)向终端设备发送第一业务的数据。
在一种可能的设计中，所述服务区域信息包括以下至少一项：所述服务区域对应的PLMN的标识；所述服务区域对应的TAI；所述服务区域对应的小区的标识。
在一种可能的设计中，所述获取第一业务的服务区域信息，包括：接收来自第二核心网网元的所述服务区域信息，所述第二核心网网元包括以下任一项：会话管理网元、多播业务网元、多播会话管理网元、网络开放功能网元、统一数据存储网元、统一数据管理网元。
在一种可能的设计中，所述方法还包括：获取所述目标小区的信息；根据所述目标小区的信息，确定所述目标小区是否在所述服务区域内。
在一种可能的设计中，所述目标小区的信息包括所述目标小区对应的TAI和/或所述目标小区的标识。
在一种可能的设计中，获取所述目标小区的信息，包括：接收来自所述终端设备的源接入网网元的所述目标小区的信息，所述源接入网网元位于所述第二网络中。
在一种可能的设计中，所述方法还包括：接收来自会话管理网元的所述第一信息。
在一种可能的设计中，所述方法还包括：向所述会话管理网元发送第二消息，所述第二消息用于获取所述第一信息。
在一种可能的设计中，所述第二消息包括第二信息，所述第二信息用于指示在所述第一网络中以所述第二传输方式向所述终端设备发送所述第一业务的数据。
在一种可能的设计中，所述第二消息为会话上下文请求消息，所述会话上下文请求消息用于请求所述终端设备的第一PDU会话的上下文，所述第一PDU会话与所述第一业务关联。
在一种可能的设计中，所述方法还包括：确定与所述第一业务关联的所述第一PDU会话。
在一种可能的设计中，确定与所述第一业务关联的所述第一PDU会话，包括：根据所述第一业务的S-NSSAI和/或DNN，确定所述S-NSSAI和/或DNN对应的PDU会话为与所述第一业务关联的所述第一PDU会话；或者，通过所述第一PDU会话从所述会话管理网元接收所述第一业务的标识，建立所述第一业务与所述第一PDU会话的关联关系；根据所述关联关系，确定与所述第一业务关联的所述第一PDU会话。
在一种可能的设计中，若所述目标小区在所述服务区域内，则所述方法还包括：向所述终端设备的源接入网网元发送第三信息，所述第三信息用于将所述终端设备重定向至所述目标小区，所述源接入网网元位于所述第二网络中。
第三方面，本申请实施例提供一种通信方法，该方法应用于终端设备由第二网络移动至第一网络，该方法用于实现接入网网元侧的功能，例如该方法可以应用于接入网网元或者接入网网元中的芯片，本申请实施例不限该方法的具体的执行主体。以该方法应用于接入网网元为例，接入网网元获取第一业务的服务区域信息，所述服务区域信息用于指示支 持所述第一业务在所述第一网络中以第一传输方式进行传输的服务区域；若所述终端设备的目标小区不在所述服务区域内，则发送第四信息，所述第四信息用于指示为所述第一业务在所述第一网络中分配无线资源，所述无线资源用于在所述第一网络中以第二传输方式向终端设备发送所述第一业务的数据；或者，若所述目标小区在所述服务区域内，则将所述终端设备重定向至所述目标小区，或者，发送第五信息，所述第五信息用于指示不为所述第一业务在所述第一网络中分配所述无线资源；其中，所述目标小区位于所述第一网络中。
采用上述方法，源接入网网元可以根据第一业务的服务区域信息，确定目标小区是否在服务区域内，进而根据目标小区是否在服务区域内进行不同的处理，从而便于通过合理的方式向终端设备发送第一业务的数据。
在一种可能的设计中，所述服务区域信息包括以下至少一项：所述服务区域对应的PLMN的标识；所述服务区域对应的TAI；所述服务区域对应的小区的标识。
在一种可能的设计中，获取第一业务的服务区域信息，包括：接收来自第三核心网网元的所述服务区域信息，所述第三核心网网元包括以下任一项：会话管理网元、移动性管理网元、多播会话管理网元；或者，接收来自所述终端设备的所述服务区域信息。
在一种可能的设计中，所述接收来自所述终端设备的所述服务区域信息，包括：接收来自所述终端设备的RRC消息，所述RRC消息包括所述服务区域信息。
第四方面，本申请实施例提供一种通信方法，该方法应用于终端设备由第二网络移动至第一网络，该方法用于实现核心网网元侧的功能，例如该方法可以应用于移动性管理网元或者移动性管理网元中的芯片，本申请实施例不限该方法的具体的执行主体。以该方法应用于移动性管理网元为例，移动性管理网元获取终端设备的目标小区的信息，所述目标小区位于所述第一网络中；向会话管理网元发送所述目标小区的信息。
在一种可能的设计中，所述目标小区的信息包括所述目标小区对应的TAI和/或所述目标小区的标识。
在一种可能的设计中，向会话管理网元发送所述目标小区的信息，包括：确定所述终端设备加入了第一业务的多播会话，或者，确定所述终端设备以第三传输方式接收所述第一业务的数据；向所述会话管理网元发送会话上下文请求消息，所述会话上下文请求消息包括所述目标小区的信息；其中，所述会话上下文请求消息用于请求所述终端设备的第一PDU会话的上下文，所述第一PDU会话与所述第一业务关联。
在一种可能的设计中，所述方法还包括：确定与所述第一业务关联的所述第一PDU会话。
在一种可能的设计中，确定与所述第一业务关联的所述第一PDU会话，包括：根据所述第一业务的S-NSSAI和/或DNN，确定所述S-NSSAI和/或DNN对应的PDU会话为与所述第一业务关联的所述第一PDU会话；或者，通过所述第一PDU会话从所述会话管理网元接收所述第一业务的标识，建立所述第一业务与所述第一PDU会话的关联关系；根据所述关联关系，确定与所述第一业务关联的所述第一PDU会话。
在一种可能的设计中，所述方法还包括：确定所述第一业务支持通过所述第一网络传输。
第五方面，本申请实施例提供一种通信方法，该方法应用于终端设备由第二网络移动至第一网络，该方法用于实现核心网网元侧的功能，例如该方法可以应用于会话管理网元 或者会话管理网元中的芯片，本申请实施例不限该方法的具体的执行主体。以该方法应用于会话管理网元为例，会话管理网元接收第二信息或第四信息，所述第二信息用于指示在所述第一网络中以第二传输方式向所述终端设备发送第一业务的数据，所述第四信息用于指示为所述第一业务在所述第一网络中分配无线资源，所述无线资源用于在所述第一网络中以所述第二传输方式向所述终端设备发送所述第一业务的数据；根据所述第二信息或第四信息，发送第一信息，所述第一信息用于建立第一传输路径，所述第一传输路径用于在所述第一网络中以第二传输方式向所述终端设备发送所述第一业务的数据。
在一种可能的设计中，所述方法还包括：向移动性管理网元或所述终端设备的源接入网网元发送所述第一业务的服务区域信息，所述服务区域信息用于指示支持所述第一业务在所述第一网络中以第一传输方式进行传输的服务区域，所述源接入网网元位于所述第二网络中。
在一种可能的设计中，所述方法还包括：通过所述终端设备的第一PDU会话向移动性管理网元发送所述第一业务的标识，所述第一PDU会话与第一业务关联。
在一种可能的设计中，所述方法还包括：指示用户面网元通过所述第二传输方式对应的传输路径向所述终端设备发送所述第一业务的数据。
第六方面，本申请实施例提供一种通信方法，该方法应用于终端设备由第二网络移动至第一网络，该方法用于实现核心网网元侧的功能，例如该方法可以应用于移动性管理网元或者移动性管理网元中的芯片，本申请实施例不限该方法的具体的执行主体。以该方法应用于移动性管理网元为例，移动性管理网元接收来自所述终端设备的源接入网网元的第四信息，所述第四信息用于指示为第一业务在所述第一网络中分配无线资源，所述无线资源用于在所述第一网络中以第二传输方式向所述终端设备发送所述第一业务的数据；向会话管理网元发送第二信息或所述第四信息，所述第二信息是根据所述第四信息得到的，所述第二信息用于指示在所述第一网络中以第二传输方式向所述终端设备发送所述第一业务的数据。
需要说明的是，上述第四方面至第六方面所描述的方法与上述第一方面至第三方面所描述的方法相对应，各个所描述的方法中相关技术特征的有益效果可以相互参照，具体不再赘述。
第七方面，本申请实施例提供一种通信方法，该方法用于实现终端侧的功能，例如该方法可以应用于终端设备或者终端设备中的芯片，本申请实施例不限该方法的具体的执行主体。以该方法应用于终端设备为例，终端设备获取第六信息，所述第六信息用于指示第二网络支持以第三传输方式发送第一业务的数据；根据所述第六信息，向所述第二网络中的网元发送加入请求，所述加入请求用于请求在所述第二网络中以所述第三传输方式向终端设备发送所述第一业务的数据。
采用上述方法，终端设备可以根据第六信息确定终端设备接入的网络是否支持以第三传输方式发送第一业务的数据，若支持，则终端设备可以发送加入请求，以加入第一业务的多播会话，若不支持，则终端设备可以不发送加入请求，从而使得终端设备在接入第二网络后，可以通过上述判断确定是否发送加入请求，以便通过合理的方式接收第一业务的数据。
在一种可能的设计中，所述第六信息包括一个或多个网络的标识，所述一个或多个网络包括所述第二网络，所述一个或多个网络支持以所述第三传输方式发送所述第一业务的 数据。
在一种可能的设计中，所述一个或多个网络的标识为一个或多个PLMN的标识。
在一种可能的设计中，所述第六信息还包括所述第二网络对应的DNN和/或S-NSSAI。
在一种可能的设计中，所述方法还包括：通过所述终端设备的第一PDU会话向所述第二网络中的网元发送所述加入请求，所述第一PDU会话对应的DNN和/或S-NSSAI与所述第二网络对应的DNN和/或S-NSSAI相同。
在一种可能的设计中，所述获取所述终端设备的第一业务的第六信息，包括：接收来自应用服务器的所述第六信息；或者，接收来自多播业务网元的所述第六信息。
第八方面，本申请实施例提供一种通信方法，该方法用于实现应用服务器侧的功能，例如该方法可以应用于应用服务器或者应用服务器中的芯片，本申请实施例不限该方法的具体的执行主体。以该方法应用于应用服务器为例，应用服务器接收来自第四核心网网元的第一通知消息，所述第一通知消息用于通知终端设备接入第二网络，所述第二网络支持以第三传输方式发送第一业务的数据；向第五核心网网元发送第七信息，所述第七信息用于指示在所述第二网络中以所述第三传输方式向所述终端设备发送所述第一业务的数据。
采用上述方法，可以由应用服务器来判断终端设备接入的网络是否支持以第三传输方式发送第一业务的数据，若支持，则可以指示核心网网元将终端设备加入第一业务的多播会话，若不支持，则可以不指示将终端设备加入第一业务的多播会话，从而使得在终端设备在接入第二网络后，可以通过合理的方式向终端设备发送第一业务的数据。
在一种可能的设计中，所述方法还包括：发送第一订阅请求，所述第一订阅请求用于请求在所述终端设备接入所述第二网络后发送所述第一通知消息。
在一种可能的设计中，向第五核心网网元发送第七信息，包括：通过第一会话对应的应用策略会话向所述第五核心网网元发送所述第七信息，所述第一会话是与所述第一业务关联的所述终端设备的PDU会话或者PDN连接。
在一种可能的设计中，所述第七信息包括所述第一业务以所述第三传输方式传输时所对应的标识。
第九方面，本申请实施例提供一种通信方法，该方法用于实现应用服务器侧的功能，例如该方法可以应用于应用服务器或者应用服务器中的芯片，本申请实施例不限该方法的具体的执行主体。以该方法应用于应用服务器为例，应用服务器接收来自第六核心网网元的第二通知消息，所述第二通知消息用于指示终端设备接入第一网络；根据所述第二通知消息，向第七核心网网元发送第八信息，所述第八信息用于建立第二传输路径，所述第二传输路径用于在所述第一网络中以第五传输方式向所述终端设备发送所述第一业务的数据。
采用上述方法，应用服务器可以根据核心网网元的通知消息获知终端设备接入第一网络，进而应用服务器可以通过第五传输方式对应的传输路径向终端设备发送第一业务的数据。
在一种可能的设计中，所述方法还包括：通过所述第二传输路径向所述终端设备发送所述第一业务的数据，所述第一业务的数据的目的地址为所述终端设备的IP地址。
在一种可能的设计中，所述方法还包括：发送第二订阅请求，所述第二订阅请求用于请求在所述终端设备接入所述第一网络后发送所述第二通知消息。
在一种可能的设计中，所述第二订阅请求包括第九信息，所述第九信息用于指示在所 述终端设备所接入的所述第一网络中的小区不支持以所述第一传输方式发送所述第一业务的数据时发送所述第二通知消息。
在一种可能的设计中，所述第二订阅请求包括第一业务的服务区域信息，所述服务区域信息用于指示支持所述第一业务在所述第一网络中以第一传输方式进行传输的服务区域，所述服务区域信息用于确定所述目标小区是否支持以所述第一传输方式发送所述第一业务的数据。
在一种可能的设计中，所述第二通知消息包括所述终端设备接入的所述第一网络中的小区的信息；所述方法还包括：根据所述小区的信息，确定所述小区不支持以所述第一传输方式发送所述第一业务的数据。
第十方面，本申请实施例提供一种通信装置，所述通信装置可以为核心网网元(比如会话管理网元或者移动性管理网元)或者设置在核心网网元内部的芯片。所述通信装置具备实现上述第一方面、第二方面、第四方面至第六方面中任一方面的功能，比如，所述通信装置包括执行上述第一方面至第六方面中任一方面涉及步骤所对应的模块或单元或手段(means)，所述功能或单元或手段可以通过软件实现，或者通过硬件实现，也可以通过硬件执行相应的软件实现。
在一种可能的设计中，所述通信装置包括处理单元、通信单元，其中，通信单元可以用于收发信号，以实现该通信装置和其它装置之间的通信，比如，通信单元用于接收来自终端设备的配置信息；处理单元可以用于执行该通信装置的一些内部操作。
在又一种可能的设计中，所述通信装置包括处理器，还可以包括收发器，所述收发器用于收发信号，所述处理器执行程序指令，以完成上述第第一方面、第二方面、第四方面至第六方面中任意可能的设计或实现方式中的方法。其中，所述通信装置还可以包括一个或多个存储器，所述存储器用于与处理器耦合，所述存储器可以保存实现上述第一方面、第二方面、第四方面至第六方面中任一方面涉及的功能的必要计算机程序或指令。所述处理器可执行所述存储器存储的计算机程序或指令，当所述计算机程序或指令被执行时，使得所述通信装置实现上述第一方面、第二方面、第四方面至第六方面中任意可能的设计或实现方式中的方法。
在又一种可能的设计中，所述通信装置包括处理器，处理器可以用于与存储器耦合。所述存储器可以保存实现上述第一方面、第二方面、第四方面至第六方面中任一方面涉及的功能的必要计算机程序或指令。所述处理器可执行所述存储器存储的计算机程序或指令，当所述计算机程序或指令被执行时，使得所述通信装置实现上述第一方面、第二方面、第四方面至第六方面中任意可能的设计或实现方式中的方法。
在又一种可能的设计中，所述通信装置包括处理器和接口电路，其中，处理器用于通过所述接口电路与其它装置通信，并执行上述第一方面、第二方面、第四方面至第六方面中任意可能的设计或实现方式中的方法。
第十一方面，本申请实施例提供一种通信装置，所述通信装置可以为接入网网元或者设置在接入网网元内部的芯片。所述通信装置具备实现上述第三方面的功能，比如，所述通信装置包括执行上述第三方面涉及步骤所对应的模块或单元或手段，所述功能或单元或手段可以通过软件实现，或者通过硬件实现，也可以通过硬件执行相应的软件实现。
在一种可能的设计中，所述通信装置包括处理单元、通信单元，其中，通信单元可以用于收发信号，以实现该通信装置和其它装置之间的通信，比如，通信单元用于接收来自 终端设备的配置信息；处理单元可以用于执行该通信装置的一些内部操作。
在又一种可能的设计中，所述通信装置包括处理器，还可以包括收发器，所述收发器用于收发信号，所述处理器执行程序指令，以完成上述第三方面中任意可能的设计或实现方式中的方法。其中，所述通信装置还可以包括一个或多个存储器，所述存储器用于与处理器耦合，所述存储器可以保存实现上述第三方面涉及的功能的必要计算机程序或指令。所述处理器可执行所述存储器存储的计算机程序或指令，当所述计算机程序或指令被执行时，使得所述通信装置实现上述第三方面中任意可能的设计或实现方式中的方法。
在又一种可能的设计中，所述通信装置包括处理器，处理器可以用于与存储器耦合。所述存储器可以保存实现上述第三方面中任一方面涉及的功能的必要计算机程序或指令。所述处理器可执行所述存储器存储的计算机程序或指令，当所述计算机程序或指令被执行时，使得所述通信装置实现上述第三方面中任意可能的设计或实现方式中的方法。
在又一种可能的设计中，所述通信装置包括处理器和接口电路，其中，处理器用于通过所述接口电路与其它装置通信，并执行上述第三方面中任意可能的设计或实现方式中的方法。
第十二方面，本申请实施例提供一种通信装置，所述通信装置可以为终端设备或者设置在终端设备内部的芯片。所述通信装置具备实现上述第七方面的功能，比如，所述通信装置包括执行上述第七方面涉及步骤所对应的模块或单元或手段，所述功能或单元或手段可以通过软件实现，或者通过硬件实现，也可以通过硬件执行相应的软件实现。
在一种可能的设计中，所述通信装置包括处理单元、通信单元，其中，通信单元可以用于收发信号，以实现该通信装置和其它装置之间的通信，比如，通信单元用于接收来自终端设备的配置信息；处理单元可以用于执行该通信装置的一些内部操作。
在又一种可能的设计中，所述通信装置包括处理器，还可以包括收发器，所述收发器用于收发信号，所述处理器执行程序指令，以完成上述第七方面中任意可能的设计或实现方式中的方法。其中，所述通信装置还可以包括一个或多个存储器，所述存储器用于与处理器耦合，所述存储器可以保存实现上述第七方面涉及的功能的必要计算机程序或指令。所述处理器可执行所述存储器存储的计算机程序或指令，当所述计算机程序或指令被执行时，使得所述通信装置实现上述第七方面中任意可能的设计或实现方式中的方法。
在又一种可能的设计中，所述通信装置包括处理器，处理器可以用于与存储器耦合。所述存储器可以保存实现上述第七方面涉及的功能的必要计算机程序或指令。所述处理器可执行所述存储器存储的计算机程序或指令，当所述计算机程序或指令被执行时，使得所述通信装置实现上述第七方面中任意可能的设计或实现方式中的方法。
在又一种可能的设计中，所述通信装置包括处理器和接口电路，其中，处理器用于通过所述接口电路与其它装置通信，并执行上述第七方面中任意可能的设计或实现方式中的方法。
第十三方面，本申请实施例提供一种通信装置，所述通信装置可以为应用服务器或者设置在应用服务器内部的芯片。所述通信装置具备实现上述第八方面或第九方面的功能，比如，所述通信装置包括执行上述第八方面或第九方面涉及步骤所对应的模块或单元或手段，所述功能或单元或手段可以通过软件实现，或者通过硬件实现，也可以通过硬件执行相应的软件实现。
在一种可能的设计中，所述通信装置包括处理单元、通信单元，其中，通信单元可以 用于收发信号，以实现该通信装置和其它装置之间的通信，比如，通信单元用于接收来自终端设备的配置信息；处理单元可以用于执行该通信装置的一些内部操作。
在又一种可能的设计中，所述通信装置包括处理器，还可以包括收发器，所述收发器用于收发信号，所述处理器执行程序指令，以完成上述第八方面或第九方面中任意可能的设计或实现方式中的方法。其中，所述通信装置还可以包括一个或多个存储器，所述存储器用于与处理器耦合，所述存储器可以保存实现上述第八方面或第九方面涉及的功能的必要计算机程序或指令。所述处理器可执行所述存储器存储的计算机程序或指令，当所述计算机程序或指令被执行时，使得所述通信装置实现上述第八方面或第九方面任意可能的设计或实现方式中的方法。
在又一种可能的设计中，所述通信装置包括处理器，处理器可以用于与存储器耦合。所述存储器可以保存实现上述第八方面或第九方面涉及的功能的必要计算机程序或指令。所述处理器可执行所述存储器存储的计算机程序或指令，当所述计算机程序或指令被执行时，使得所述通信装置实现上述第八方面或第九方面任意可能的设计或实现方式中的方法。
在又一种可能的设计中，所述通信装置包括处理器和接口电路，其中，处理器用于通过所述接口电路与其它装置通信，并执行上述第八方面或第九方面任意可能的设计或实现方式中的方法。
可以理解地，上述第十、十一、十二、十三方面中，处理器可以通过硬件来实现也可以通过软件来实现，当通过硬件实现时，该处理器可以是逻辑电路、集成电路等；当通过软件来实现时，该处理器可以是一个通用处理器，通过读取存储器中存储的软件代码来实现。此外，以上处理器可以为一个或多个，存储器可以为一个或多个。存储器可以与处理器集成在一起，或者存储器与处理器分离设置。在具体实现过程中，存储器可以与处理器集成在同一块芯片上，也可以分别设置在不同的芯片上，本申请实施例对存储器的类型以及存储器与处理器的设置方式不做限定。
第十四方面，本申请实施例提供一种通信系统，该通信系统包括上述第一方面中的会话管理网元和上述第四方面中的移动性管理网元；或者，该通信系统包括上述第二方面中的移动性管理网元和上述第五方面中的会话管理网元；或者，该通信系统包括上述第三方面中的接入网网元、上述第五方面中的会话管理网元和上述第六方面中的移动性管理网元。
第十五方面，本申请提供一种计算机可读存储介质，所述计算机存储介质中存储有计算机可读指令，当计算机读取并执行所述计算机可读指令时，使得计算机执行上述第一方面至第九方面的任一种可能的设计中的方法。
第十六方面，本申请提供一种计算机程序产品，当计算机读取并执行所述计算机程序产品时，使得计算机执行上述第一方面至第九方面的任一种可能的设计中的方法。
第十七方面，本申请提供一种芯片，所述芯片包括处理器，所述处理器与存储器耦合，用于读取并执行所述存储器中存储的软件程序，以实现上述第一方面至第九方面的任一种可能的设计中的方法。
本申请的这些方面或其它方面在以下实施例的描述中会更加简明易懂。
附图说明
图1为本申请实施例提供的第一网络独立部署的网络架构示意图；
图2为本申请实施例提供的第二网络独立部署的网络架构示意图；
图3为本申请实施例提供的第一网络和第二网络联合部署的网络架构示意图；
图4为本申请实施例提供的在4G网络和5G网络传输第一业务的数据的流程示意图；
图5为本申请实施例一提供的通信方法所对应的流程示意图；
图6为本申请实施例二提供的通信方法所对应的流程示意图；
图7为本申请实施例三提供的通信方法所对应的流程示意图；
图8为本申请实施例四提供的通信方法所对应的流程示意图；
图9为本申请实施例五提供的通信方法所对应的流程示意图；
图10为本申请实施例六提供的通信方法所对应的流程示意图；
图11为本申请实施例中所涉及的装置的可能的示例性框图；
图12为本申请实施例提供的一种核心网网元的结构示意图；
图13为本申请实施例提供的一种接入网网元的结构示意图；
图14为本申请实施例提供的一种终端设备的结构示意图；
图15为本申请实施例提供的一种应用服务器的结构示意图。
具体实施方式
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行描述。
首先，对本申请实施例中的部分用语进行解释说明，以便于本领域技术人员理解。
(1)第一网络、第二网络
第一网络和第二网络可以为支持不同通信制式的网络，第一网络也可以称为第一通信制式网络，第二网络也可以称为第二通信制式网络。比如，第一网络可以为4G网络，第二网络可以为5G网络，其中5G网络也可以称为5G通信系统，4G网络也可以称为演进型分组系统(evolved packet system，EPS)网络或4G通信系统。又比如，第一网络可以为4G网络中的某一公共陆地移动网络(public land mobile network，PLMN)，第二网络可以为5G网络中的某一PLMN。应理解，第一网络和第二网络还可以是其他类型的网络，具体不做限定。本申请实施例中将以第一网络为4G网络、第二网络为5G网络为例进行描述。
(2)PDN连接、PDU会话
协议数据网络(protocol data network，PDN)连接是指在第一网络(比如4G网络)内，为终端设备建立的数据传输通道。一个PDN连接可以包括一个或多个承载(即EPS承载)。PDN连接的上下文可以包括PDN连接使用的互联网协议(internet protocol，IP)地址、以及PDN连接中的每个EPS承载的上下文。EPS承载的上下文可以包括EPS承载的服务质量(quality of service，QoS)信息、EPS承载的标识(EPS bearer identity，EBI)、传输流模板(traffic flow template，TFT)等。
协议数据单元(protocol data unit，PDU)会话是指在第二网络(比如5G网络)内，为终端设备建立的数据传输通道。一个PDU会话可以包括一个或多个QoS流。PDU会话的上下文可以包括PDU会话使用的IP地址、以及PDU会话中的每个QoS流的信息。QoS流的信息可以包括QoS流的QoS信息、QoS流的标识(QoS flow identity，QFI)、以及QoS流模板。
示例性地，4G网络中的PDN连接与5G网络中的PDU会话可以存在对应关系，在4G网络和5G网络共存的场景中，当终端设备从5G网络移动到4G网络时，在4G网络内建 立与终端设备的PDU会话1相对应的PDN连接1，比如可以根据PDU会话1的上下文得到PDN连接1的上下文，进而可以根据PDN连接1的上下文建立PDN连接1。其中，根据PDU会话1的上下文得到PDN连接1的上下文的实现可以参见现有技术。比如，PDU会话1和PDN连接1的IP地址可以相同；PDU会话1包括第一QoS流，第一QoS流可以为一个业务数据流或者一组业务数据流，PDN连接1可以包括第一EPS承载，则可以根据预定义的映射规则，将第一QoS流映射为第一EPS承载，进而可以根据第一QoS流的信息得到第一EPS承载的上下文。
(3)传输方式
本申请实施例中涉及五种传输方式，分别为第一传输方式、第二传输方式、第三传输方式、第四传输方式、第五传输方式。
第一传输方式可以为第一网络(比如4G网络)的多播传输方式，多播传输方式可以理解为“点对多点”(point to multi-point，PTM)通信。第一传输方式可以适用于第一网络和第二网络联合部署(或者说第一网络和第二网络共存)的场景中，或者也可以适用于第一网络独立部署的场景中。第一传输方式可以是指通过多播承载向终端设备发送数据，其中，多播承载也可以称为MBMS承载。第一传输方式也可以称为多播承载传输方式，或MBMS承载传输方式，或eMBMS传输方式。在第一传输方式中，数据包的目的地址为多播IP地址。
第五传输方式可以为第一网络(比如4G网络)的单播传输方式，单播传输方式可以理解为“点对点”(point to point，PTP)通信。第五传输方式可以适用于第一网络和第二网络联合部署的场景中，或者也可以适用于第一网络独立部署的场景中。第五传输方式可以是指通过PDN连接(或者EPS承载，EPS承载也可以称为EPS单播承载或者单播承载)向终端设备发送数据。在第五传输方式中，数据包的目的地址为终端设备的IP地址。
第二传输方式可以为第一网络(比如4G网络)的另一种单播传输方式。第二传输方式可以适用于第一网络和第二网络联合部署的场景中。在第二传输方式中，数据也是通过第一网络的PDN连接发送给终端设备。第二传输方式与第五传输方式的区别是：在第二传输方式中，数据是先发送给多播用户面网元，由多播用户面网元发送给终端设备的PDN连接的用户面网元，再由用户面网元通过该PDN连接发送给终端设备；而在第五传输方式中，数据是不经过多播用户面网元的。在第二传输方式中，数据包的目的地址为多播IP地址。
第三传输方式可以为第二网络(比如5G网络)的多播传输方式。第三传输方式可以适用于第一网络和第二网络联合部署的场景中，或者也可以适用于第二网络独立部署的场景中。当采用第三传输方式传输多播业务的数据时，可以为多播业务创建对应的多播会话。其中，一个多播业务可以对应一个多播会话，一个多播业务可以包括一个或多个业务数据流，多个业务数据流可以对应一个或多个多播QoS流，也就是说，多播会话内的多播业务的数据可以以多播QoS流的形式传输，本申请实施例对此不作限定。第三传输方式也可以称为5MBS或5G MBS传输方式。第三传输方式可以包括共享MBS传输方式(shared MBS delivery)和单独MBS传输方式(individual MBS delivery)两种方式，其中，共享MBS传输方式是指先将数据发送给多播用户面网元，由多播用户面网元通过共享隧道将数据直接发送给接入网网元，再由接入网网元发送给终端设备；单独MBS传输方式是指先将数据发送给多播用户面网元，由多播用户面网元将数据发送给终端设备的PDU会话的锚点 用户面网元，由锚点用户面网元通过该PDU会话发送给终端设备。在第三传输方式中，数据包的目的地址为多播IP地址。
第四传输方式可以为第二网络(比如5G网络)的单播传输方式。第四传输方式可以适用于第一网络和第二网络联合部署的场景中，或者也可以适用于第二网络独立部署的场景中。第四传输方式可以是指通过终端设备的PDU会话向终端设备发送数据；其中，PDU会话内的数据可以以QoS流的形式传输，本申请实施例对此不作限定。与第三传输方式中的单独MBS传输方式的区别是：在第四传输方式中，数据包是不通过多播会话传输的，数据包的目的地址为终端设备的IP地址。
需要说明的是：本申请实施例中的“多播”是广义上的概念，可以包括组播(multicast)和/或广播(broadcast)，即本申请实施例中的多播业务传输既可以应用于组播业务传输，也可以应用于广播业务传输。可以理解地，本申请实施例中提及的“多播”可以替换为“组播”或“广播”或“组播/广播”。
下面对本申请实施例提供的网络架构进行描述。
一、第一网络独立部署的网络架构
图1为本申请实施例提供的第一网络独立部署的一种可能的网络架构示意图。比如第一网络为4G网络，该网络架构可以支持4G网络的eMBMS。如图1所示，该网络架构中可以包括如下可能的设备或网元：
(1)终端设备：又称之为用户设备(user equipment，UE)、终端(terminal)、移动台(mobile station，MS)、移动终端(mobile terminal，MT)、客户前置设备(Customer Premise Equipment，CPE)、家庭网关(Residential Gateway，RG)等，可以是一种具有无线收发功能的设备。终端设备可以部署在陆地上，包括室内、室外、和/或手持或车载；也可以部署在水面上(如轮船等)；还可以部署在空中(例如飞机、气球和卫星上等)。终端设备可以包括具有无线通信功能的手持式设备、车载设备、可穿戴设备或计算设备。示例性地，终端设备可以是手机(mobile phone)、平板电脑或带无线收发功能的电脑。终端设备还可以是虚拟现实(virtual reality，VR)终端设备、增强现实(augmented reality，AR)终端设备、工业控制中的无线终端、无人驾驶中的无线终端、远程医疗中的无线终端、智能电网中的无线终端、智慧城市(smart city)中的无线终端、和/或智慧家庭(smart home)中的无线终端等。
(2)接入网网元：即为将终端设备接入到无线网络的节点或设备，接入网网元又可以称为无线接入网(radio access network，RAN)设备或接入网设备。接入网网元例如包括但不限于：新一代基站(generation node B，gNB)、演进型节点B(evolved node B，eNB)、下一代演进型节点B(next generation eNB，ng-eNB)、无线回传设备、无线网络控制器(radio network controller，RNC)、节点B(node B，NB)、基站控制器(base station controller，BSC)、基站收发台(base transceiver station，BTS)、家庭基站((home evolved nodeB，HeNB)或(home node B，HNB))、基带单元(baseBand unit，BBU)、传输接收点(transmitting and receiving point，TRP)、发射点(transmitting point，TP)、移动交换中心、无线局域网(wireless local area networks，WLAN)中的接入点(access point，AP)等。接入网网元也可以是完成基站部分功能的模块或单元，例如集中式单元(central unit，CU)或者分布式单元(distributed unit，DU)。本申请实施例对接入网网元所采用的具体技术和具体设备形态不 作限定。比如在4G网络中，接入网网元可以为eNB。
(3)移动性管理网元：负责对终端设备进行鉴权、授权，移动性管理等。比如在4G网络中，移动性管理网元可以为移动管理实体(mobility management entity，MME)。
(4)多播业务网元：用于保存签约数据，分配临时移动组标识(temporary mobile group identity，TMGI)，发起或终止MBMS承载资源等。比如在4G网络中，多播业务网元可以为多媒体广播组播业务中心(broadcast-multicast service centre，BM-SC)。
(5)多播业务网关：用于接收多播业务的数据，以及将多播业务的数据发送给接入网网元。比如在4G网络中，多播业务网关可以为MBMS网关(MBMS gateway，MBMS-GW)，MBMS-GW通过与BM-SC之间的SGimb接口，从BM-SC接收多播业务的数据，并将多播业务的数据发送给接入网网元。
(6)应用服务器(application server，AS)：为业务的数据来源，用于向终端设备发送业务的数据。比如在4G网络中，应用服务器可以为群组通信服务应用服务器(group communication service application server，GSC AS)。
(7)服务网关(serving gateway，SGW)：负责数据的转发，下行数据存储等。
(8)分组数据网络网关(packet data network gateway，PGW)：PGW包括PGW用户面(PGW-user plane，PGW-U)和PGW控制面(PGW-control plane，PGW-C)，其中，PGW-C为4G网络的控制面网元，为终端设备的PDN连接提供控制面服务；PGW-U是4G网络的用户面网元，为终端设备的PDN连接提供用户面服务。
示例性地，SGW和PGW可以合设，当SGW和PGW合设时，可以称为S/P-GW。图1中是以SGW和PGW合设为例进行示意的。
(9)策略控制网元：负责产生用户建立数据承载的策略。比如在4G网络中，策略控制网元可以为策略和计费规则功能(policy and charging rules function，PCRF)网元。
(10)数据管理网元：用于保存用户的签约数据。比如在4G网络中，数据管理网元可以是归属签约用户服务器(home subscriber server，HSS)。
需要说明的是，上述图1所示意的网络架构中除终端设备和接入网网元外，其它的网元均可以称为核心网网元。此外，上述图1所示意的网络架构中还可以包括其它可能的设备或网元，具体不做限定。
基于上述图1所示意的网络架构，以第一业务为例，下面对采用不同传输方式传输第一业务的数据时的传输路径进行描述。
比如，AS可以通过第一传输方式(即eMBMS传输方式)向终端设备发送第一业务的数据。eMBMS传输方式对应的传输路径可以为：AS→BM-SC→MBMS-GW→eNB→终端设备，即AS通过MB2-U接口将数据发送给BM-SC，BM-SC通过SGimb接口将数据发送给MBMS-GW，MBMS-GW通过M1接口将数据发送给eNB，进而由eNB通过Uu接口(或称为空口)将数据发送给终端设备。
又比如，AS也可以通过第五传输方式向终端设备发送第一业务的数据。第五传输方式对应的传输路径可以为：AS→S/P-GW→eNB→终端设备，即AS通过SGi接口将数据发送给S/P-GW，S/P-GW通过S1-U接口将数据发送给eNB，进而由eNB通过Uu接口将数据发送给终端设备。此外，当SGW和PGW分设时，上述第五传输方式对应的传输路径可以为：AS→PGW-U网元→SGW网元→eNB→终端设备。
二、第二网络独立部署的网络架构
图2为本申请实施例提供的第二网络独立部署的一种可能的网络架构示意图。比如第二网络为5G网络，该网络架构可以支持5G网络的MBS。如图2所示，该网络架构中可以包括如下可能的设备或网元：
(1)终端设备：具体参见上文的描述。
(2)接入网网元：具体可以参见上文的描述。比如在5G网络中，接入网网元可以为gNB。
(3)移动性管理网元：用于对用户进行鉴权、授权，对用户的移动性进行管理。比如在5G网络中，移动性管理网元可以为接入管理功能(access and mobility management function，AMF)网元。
(4)会话管理网元：用于会话管理、终端设备的IP地址分配和管理、选择和管理用户平面功能。比如在5G网络中，会话管理网元可以为会话管理功能(session management function，SMF)网元。
(5)用户面网元：用于接收用户面数据并发送给接入网网元。比如在5G网络中，用户面网元可以为用户面功能(user plane function，UPF)网元。
(6)策略控制网元：用于提供指导网络行为的统一策略框架，为控制面功能网元提供策略规则信息等。比如在5G网络中，策略控制网元可以为策略控制功能(policy control function，PCF)网元。
(7)多播会话管理网元：是用于控制多播业务的会话管理网元。比如在5G网络中，多播会话管理网元可以为组播/广播(multicast/broadcast，MB)-SMF网元，MB-SMF控制MB-UPF到接入网网元之间的路径的建立。
(8)多播用户面网元：用于传输多播业务的数据等。比如在5G网络中，多播用户面网元可以为MB-UPF网元。
(9)应用服务器：为业务的数据的来源，用于向终端设备发送业务的数据。比如在5G网络中，应用服务器也可以替换为应用功能(application function，AF)网元。
(10)网络开放功能(network exposure function，NEF)网元：对外提供5G网络的能力和事件的开放，以及接收相关的外部消息。
(11)多播业务网元：比如在5G网络中，多播业务网元可以为组播/广播业务(multicast/broadcast service function，MBSF)网元，MBSF网元可以包括MBSF控制面(即MBSF-C)网元和MBSF用户面(即MBSF-U)网元。
其中，MBSF-C网元具有业务层的功能，例如支持流(streaming)协议、支持可靠重传协议等，MBSF-C网元还可以给终端设备发送业务通告(service announcement)，给终端设备分发多播业务的秘钥等。MBSF-C网元可以是可选网元，当MBSF-C网元存在时，AS可以与MBSF-C网元直接接口以便将业务需求发送给核心网，进而MBSF-C网元再与MB-SMF网元接口以便创建多播会话(可选地，MBSF-C网元也可以通过NEF网元与MB-SMF接口)，或者，AS也可以先与NEF网元接口，再由NEF网元与MBSF-C网元接口，进而MBSF-C网元再与MB-SMF网元接口。示例性地，MBSF-C网元可以与NEF网元合设。
MBSF-U网元的主要功能是对多播业务的数据包进行处理，例如对数据包按流协议进行封装、对数据包进行加密、对数据包进行编码等。示例性地，MBSF-U网元可以是可选网元，若多播业务的数据包需要核心网进行处理，则AS可以先将数据包发送给MBSF-U 网元，由MBSF-U网元处理后发送给MB-UPF网元。应理解，本申请实施例下文中，是以AS将数据包发送给MB-UPF网元为例进行描述的，具体实施中，AS也可以先将数据包发送给MBSF-U网元，由MBSF-U网元处理后发送给MB-UPF网元。
需要说明的是，上述图2所示意的网络架构中除终端设备和接入网网元外，其它的网元均可以称为核心网网元。此外，上述图2所示意的网络架构中还可以包括其它可能的设备或网元，比如统一数据库(unified data repository，UDR)、数据管理网元，在5G网络中，数据管理网元可以为统一数据管理网元(unified data management，UDM)。
基于上述图2所示意的网络架构，以第一业务为例，下面对采用不同传输方式传输第一业务时的传输路径进行描述。
比如，AS可以通过第三传输方式(即5MBS传输方式)向终端设备发送第一业务的数据。具体来说，当以第三传输方式发送数据时，AS可将数据发送给MB-UPF网元(图2中的N6接口或MB2-U接口，即AS与MB-UPF网元之间的直接接口)。若接入网网元支持5G MBS，MB-UPF网元可以通过MB-UPF网元与接入网网元间的共享隧道(MB-N3接口，共享隧道是指通过该隧道MB-UPF可以给接入网网元发送一份数据，接入网网元可发送给多个终端设备)将数据发送给接入网网元。接入网网元可以根据空口条件、收听该业务的终端数量等灵活决定播放方式，即PTM方式或PTP方式。其中，针对于PTM方式来说，接入网网元仅发送一份数据，多个终端设备均可接收；针对于PTP方式来说，接入网网元发送一份数据只能由一个终端设备接收。针对同一业务，接入网网元可同时采用PTM方式和PTP方式，例如，针对终端设备1、终端设备2采用PTM方式，针对终端设备3采用PTP方式。因此，第三传输方式中的共享MBS传输方式对应的传输路径为：AS→MB-UPF网元→gNB→终端设备。若接入网网元不支持5G MBS，则MB-UPF网元可以将数据发送给PDU会话的锚点UPF网元，进而该UPF网元可以通过该PDU会话通过接入网网元向终端设备发送数据，因此，第三传输方式中的单独MBS传输方式对应的传输路径可以为：AS→MB-UPF网元→UPF网元→gNB→终端设备。
又比如，AS也可以通过第四传输方式向终端设备发送第一业务的数据。第四传输方式对应的传输路径可以为：AS→UPF网元→gNB→终端设备，即AS将数据发送给PDU会话的锚点UPF网元(暂未在图中示意AS与该UPF网元之间的接口)，进而该UPF网元可以通过PDU会话向终端设备发送数据。
三、第一网络和第二网络联合部署的网络架构
图3为本申请实施例提供的第一网络和第二网络联合部署的一种可能的网络架构示意图。比如第一网络为4G网络，第二网络为5G网络，该网络架构可以支持4G网络的eMBMS和5G网络的MBS。如图3所示，该网络架构中可以包括4G网络中的网元、5G网络中的网元、4G网络和5G网络共用的网元(或者说4G网络和5G网络合设的网元)、AS以及终端设备。其中，4G网络中的网元可以包括第一接入网网元(即4G网络中的eNB)、第一移动性管理网元(即4G网络中的MME)、SGW、MBMS-GW等。5G网络中的网元可以包括第二接入网网元(即5G网络中的gNB)、第二移动性管理网元(即5G网络中的AMF网元)、MB-UPF、MB-SMF等。4G网络和5G网络共用的网元可以包括会话管理网元(即PGW-C+SMF)、用户面网元(即PGW-U+UPF)、MBSF+BM-SC、策略控制网元(即PCF网元)等。
其中，PGW-C+SMF可以包括SMF网元和PGW-C网元的功能。SMF+PGW-C也可被 称为PGW-C+SMF，只要是包含SMF网元和PGW-C网元的功能的网元均与本网元相同。本申请实施例中的“+”即表示两个网元是合设的。
UPF+PGW-U可以包括UPF网元和PGW-U网元的功能。UPF+PGW-U也可被称为PGW-U+UPF，只要是包含UPF网元和PGW-U网元的功能的网元均与本网元相同。
MBSF+BM-SC可以包括MBSF网元和BM-SC的功能。MBSF+BM-SC也可以简称为MBSF(即将BM-SC的功能合成到了MBSF网元中)，只要是包含MBSF网元和BM-SC的功能的网元均与本网元相同。当MBSF网元被分为MBSF-C和MBSF-U两部分时，对应的BMSC的功能也被相应地拆分到MBSF-C和MBSF-U中，即BMSC的控制面部分功能与MBSF-C合设，BMSC的用户面部分功能与MBSF-U合设。可以理解地，图3中是以MBSF网元和BM-SC是合设的为例进行示意的，在实际部署时，MBSF网元和BM-SC网元也可以是分开部署的，此种情形下，BMSC和MBSF网元可以存在接口，以便于BMSC和MBSF网元进行通信。
可以理解地，上述图3所示意的网络架构中还可以包括其它可能的设备或网元，比如UDR网元、HSS+UDM、NEF网元等。其中，HSS+UDM用于实现HSS网元和UDM网元的功能，HSS+UDM也可以简称为UDM网元。NEF网元可以与MBSF网元合设，或者，也可以不与MBSF网元合设。当NEF网元不与MBSF网元合设时，AS可以通过NEF网元与MBSF网元通信，或者AS也可以通过AS与MBSF网元的接口直接与MBSF网元通信。
在图3所示意的网络架构中，AS可以在4G网络中以eMBMS传输方式发送第一业务的数据，以及在5G网络中以5MBS传输方式发送第一业务的数据。下面结合图4描述一种可能的流程。
图4为本申请实施例提供的在4G网络和5G网络传输第一业务的数据的流程示意图，如图4所示，该流程可以包括：
S401，AS向MBSF网元请求在4G网络中以eMBMS传输方式发送第一业务的数据，以及在5G网络中以5MBS传输方式发送第一业务的数据。
S402，MBSF网元在4G网络中创建第一业务的MBMS承载，以及在5G网络中创建第一业务的多播会话。
此处，在4G网络中创建第一业务的MBMS承载可以是指，建立MB2-U接口，并建立从MBSF网元到MBMS-GW，以及从MBMS-GW到eNB的接口，并且通知eNB建立MBMS空口承载。
在5G网络中创建第一业务的多播会话可以是指，建立AS与MB-UPF网元之间的接口。当存在MBSF网元时，建立AS与MBSF网元之间的MB2-U接口，并建立MBSF网元与MB-UPF网元之间的接口。
S403，AS在4G网络中以eMBMS传输方式发送第一业务的数据，以及在5G网络中以5MBS传输方式发送第一业务的数据。
需要说明的是，在5G网络中，在任何终端设备加入第一业务的多播会话前，第一业务的数据仅仅发送到MB-UPF网元。也就是说，若没有终端设备加入第一业务的多播会话，则该数据不会继续往下发送，即不会发送给接入网网元或任何PDU会话的锚点UPF网元。
针对于上述S401至S403，以图3所示意的网络架构(即BM-SC与MBSF网元合设)为例，在一种可能的实现方式中，AS可以向MBSF网元发送请求消息，请求消息用于请 求在4G网络中以eMBMS传输方式发送第一业务的数据以及在5G网络中以5MBS传输方式发送第一业务的数据。相应地，MBSF网元接收到请求消息后，可以在4G网络中创建MBMS承载，进而AS可以在4G网络中以eMBMS传输方式发送第一业务的数据；以及，MBSF网元接收到请求消息后，可以在5G网络中创建多播会话，进而AS可以在5G网络以5MBS传输方式将第一业务的数据发送给MB-UPF网元。
在又一种可能的实现方式中，AS可以向MBSF网元发送请求消息1，请求消息1用于请求在4G网络中以eMBMS传输方式发送第一业务的数据；相应地，MBSF网元接收到请求消息1后，可以在4G网络中创建MBMS承载，进而AS可以在4G网络中以eMBMS传输方式发送第一业务的数据。以及，AS可以向MBSF网元发送请求消息2，请求消息2用于请求在5G网络中以5MBS传输方式发送第一业务的数据；相应地，MBSF网元接收到请求消息2后，可以在5G网络中创建多播会话，进而AS可以在5G网络以5MBS传输方式将第一业务的数据发送给MB-UPF网元。
需要说明的是，当BM-SC与MBSF网元分设时，AS可以向BM-SC发送请求消息1，请求消息1用于请求在4G网络中以eMBMS传输方式发送第一业务的数据；以及向MBSF网元发送请求消息2，请求消息2用于请求在5G网络中以5MBS传输方式发送第一业务的数据。后续，AS可以在4G网络中以eMBMS传输方式发送第一业务的数据以及在5G网络中以5MBS传输方式发送第一业务的数据。
进一步地，上述流程还可以包括S404a和S405a，或者S404b和S405b，或者S404c和S405c。
S404a，终端设备加入第一业务的多播会话。
此处，终端设备可以请求加入第一业务的多播会话，比如终端设备可通过PDU会话的信令请求加入第一业务的多播会话。该方式中，在将终端设备加入多播会话的过程中，可以建立从MB-UPF网元到接入网网元的共享隧道，并且，接入网网元可以为终端设备配置通过多播会话接收第一业务的数据的无线资源。应理解，该传输方式为共享MBS传输方式。接入网网元为终端设备配置的无线资源可以是PTP方式对应的无线资源，即只针对该终端设备接收第一业务的数据而分配的无线资源，或者是PTM方式对应的无线资源，即针对多个终端设备(包括该终端设备)接收该第一业务的数据而分配的无线资源。
S405a，AS通过传输路径a向终端设备发送第一业务的数据，相应地，终端设备可以通过传输路径a接收第一业务的数据。
此处，传输路径a(即共享MBS传输方式对应的路径)可以为：AS→MB-UPF→gNB→终端设备。
S404b，终端设备加入第一业务的多播会话。
此处，终端设备可以请求加入第一业务的多播会话，比如终端设备可通过PDU会话的信令请求加入第一业务的多播会话。该方式中，在将终端设备加入多播会话的过程中，可以建立从MB-UPF到PGW-U+UPF的隧道，并且PGW-U+UPF可以将从MB-UPF网元接收到的第一业务的数据映射到终端设备的PDU会话，进而通过PDU会话发送给终端设备。应理解，该传输方式为单独MBS传输方式。
S405b，AS通过传输路径b向终端设备发送第一业务的数据，相应地，终端设备可以通过传输路径b接收第一业务的数据。
传输路径b(即单独MBS传输方式对应的传输路径)可以为： AS→MB-UPF→PGW-U+UPF→gNB→终端设备。
S404c，终端设备进入支持第一业务在4G网络中以eMBMS传输方式进行传输的服务区域。
S405c，AS通过传输路径c向终端设备发送第一业务的数据，相应地，终端设备可以通过传输路径c接收第一业务的数据。
此处，传输路径c(即eMBMS传输方式对应的传输路径)可以为：AS→MBSF网元→MBMS-GW→eNB→终端设备。
需要说明的是：(1)上述图1、图2和图3中所述的网元也可以称为实体或功能实体，例如AMF网元也可以称为AMF实体或AMF功能实体，SMF网元也可以称为SMF实体或SMF功能实体。上述网元既可以是硬件设备中的网络元件，也可以是在专用硬件上运行的软件功能，或者是平台(例如，云平台)上实例化的虚拟化功能。可选的，上述网元可以由一个设备实现，也可以由多个设备共同实现，还可以是一个设备内的一个功能模块，本申请实施例对此不作具体限定。
(2)在图1、图2或图3中，各个网元之间连线附近的字母和数字表示各个网元之间的通信接口的名称，这些通信接口的含义可参见相关标准协议中定义的含义。可以理解地，各个网元之间的通信接口还可以具有其他名称，本申请实施例对此不做限定。
(3)上述图1、图2和图3描述的网络架构以及业务场景是为了更加清楚的说明本申请实施例的技术方案，并不构成对于本申请实施例提供的技术方案的限定，本领域普通技术人员可知，随着通信系统架构的演变和新业务场景的出现，本申请实施例提供的技术方案对于类似的技术问题，同样适用。
(4)针对于本申请实施例中的终端设备、接入网网元、核心网网元、应用服务器等，以终端设备为例，用于实现终端设备的功能的装置可以是终端设备，也可以是能够支持终端设备实现该功能的装置，例如芯片系统或可实现终端设备功能的组合器件、部件，该装置可以被安装在终端设备中。本申请实施例中，芯片系统可以由芯片构成，也可以包括芯片和其他分立器件。本申请实施例提供的技术方案中，以用于实现终端设备的功能的装置是终端设备为例，描述本申请实施例提供的技术方案。
基于上文的描述，本申请实施例中将针对终端设备在第一网络和第二网络之间移动时的相关实现进行研究。具体来说，本申请实施例提供一种通信方法，用于实现当终端设备由第二网络移动至第一网络或者由第一网络移动至第二网络后，向终端设备发送第一业务的数据。
下面结合实施例一至实施例六对本申请实施例提供的通信方法进行详细描述。需要说明的是：实施例一至实施例六中所涉及的信息1可以替换为第一信息、信息2可以替换为第二信息、信息4可以替换为第三信息、信息5可以替换为第四信息、信息6可以替换为第五信息、信息7可以替换为第六信息、信息8可以替换为第七信息、信息9可以替换为第八信息、信息10可以替换为第九信息。实施例一至实施例六中所涉及的传输路径1可以替换为第一传输路径，传输路径4可以替换为第二传输路径。实施例一至实施例六中所涉及的核心网网元1可以替换为第一核心网网元、核心网网元2可以替换为第二核心网网元、核心网网元3可以替换为第三核心网网元、核心网网元4可以替换为第四核心网网元、核心网网元5可以替换为第五核心网网元、核心网网元6可以替换为第六核心网网元、核 心网网元7可以替换为第七核心网网元。
示例性地，实施例一至实施例三所适用的场景可以为：当终端设备在5G网络中以5MBS传输方式接收第一业务的数据时，终端设备由5G网络移动至4G网络。该场景中，在终端设备由5G网络移动至4G网络之前，终端设备处于连接态。此种情形下，终端设备由5G网络移动至4G网络，可以通过切换流程接入4G网络，或者也可以通过重定向接入4G网络，具体可以参见实施例一至实施例三中的描述。
当终端设备从5G网络移动至4G网络时，若终端设备的目标小区支持通过4G网络的多播传输方式(即eMBMS传输方式)传输第一业务的数据，则可以不用将第一业务切换到经过4G网络的单播传输方式进行传输，此种情形下，终端设备可以在接入目标小区后，直接通过eMBMS传输方式来接收第一业务的数据。若终端设备的目标小区不支持通过eMBMS传输方式传输第一业务的数据，则为了保持第一业务的连续性，可以将第一业务的数据切换到经过4G网络的单播传输方式进行传输。
然而，目前无法确定终端设备的目标小区是否支持通过4G网络的多播传输方式传输第一业务的数据。
基于此，本申请提供实施例一至实施例三，用于确定终端设备的目标小区是否支持通过4G网络的多播传输方式传输第一业务的数据，进而可以在终端设备从5G网络移动至4G网络后，通过合理的方式向终端设备发送第一业务的数据。
实施例一
在实施例一中，将以图3所示意的网络架构为例，描述通信方法的一种可能的实现流程。
图5为本申请实施例一提供的通信方法所对应的流程示意图。如图5所示，该流程可以包括：
S501，PGW-C+SMF获取第一业务的服务区域信息，服务区域信息用于指示支持第一业务在4G网络中以第一传输方式(即eMBMS传输方式)进行传输的服务区域。
示例性地，服务区域信息包括以下至少一项：服务区域对应的PLMN的标识；服务区域对应的TAI；服务区域对应的小区的标识。
PGW-C+SMF获取第一业务的服务区域信息的实现方式可以有多种。下面描述两种可能的实现方式。
(1)实现方式1
核心网网元1可以向PGW-C+SMF发送第一业务的服务区域信息，进而PGW-C+SMF可以接收第一业务的服务区域信息。核心网网元1可以包括以下任一项：MBSF网元、MB-SMF网元、NEF网元、PCF网元、UDM网元、UDR网元。
示例性地，MBSF网元/NEF网元可以接收AS发送的第一业务的播放范围信息，进而根据第一业务的播放范围信息确定第一业务的服务区域信息。进一步地，比如，MBSF网元/NEF网元可以将第一业务的服务区域信息发送给PGW-C+SMF；又比如，MBSF网元/NEF网元可以先将第一业务的服务区域信息发送给MB-SMF网元，进而由MB-SMF网元发送给PGW-C+SMF；又比如，MBSF网元/NEF网元可以先将第一业务的服务区域信息发送给PCF网元，进而由PCF网元发送给PGW-C+SMF；又比如，MBSF网元/NEF网元可以将第一业务的服务区域信息保存在UDR网元/UDM网元中，进而由UDR网元/UDM网元发送给PGW-C+SMF；又比如，MBSF网元/NEF网元可以将第一业务的服务区域信息保 存在UDR网元/UDM网元中，MB-SMF网元从UDR网元/UDM网元获取第一业务的服务区域信息，进而发送给PGW-C+SMF。
示例性地，PGW-C+SMF可以在接收到终端设备发送的加入请求(用于请求加入第一业务的多播会话)后，向核心网网元1请求第一业务的服务区域信息，进而可以接收核心网网元1发送的第一业务的服务区域信息。
(2)实现方式2
终端设备可以向PGW-C+SMF发送第一业务的服务区域信息，进而PGW-C+SMF可以接收第一业务的服务区域信息。示例性地，终端设备在加入第一业务的多播会话之前，可以接收AS或者MBSF网元发送的业务通告，业务通告中包括第一业务的服务区域信息，进而，终端设备可以向PGW-C+SMF发送第一业务的服务区域信息。
在一个示例中，终端设备可以在加入第一业务的多播会话时，向PGW-C+SMF发送第一业务的服务区域信息，此种情形下，第一业务的服务区域信息和加入请求可以携带在同一条消息中，该消息可以为PDU会话建立请求消息或PDU会话修改请求消息。
在又一个示例中，终端设备也可以在加入第一业务的多播会话后，向PGW-C+SMF发送第一业务的服务区域信息，此种情形下，第一业务的服务区域信息可以携带在PDU会话修改请求消息中。
S502，AMF网元向PGW-C+SMF发送终端设备的目标小区的信息；相应地，PGW-C+SMF可以接收目标小区的信息。
示例性地，目标小区的信息可以包括目标小区对应的TAI和/或目标小区的标识。AMF网元向PGW-C+SMF发送目标小区的信息之前，可以先获取目标小区的信息。比如，当终端设备由5G网络移动至4G网络时，终端设备的源接入网网元(即5G网络中的gNB)可以向AMF网元发送切换请求，切换请求包括目标小区的信息。进而，AMF网元可以从切换请求中获取目标小区的信息。
AMF网元向PGW-C+SMF发送目标小区的信息的实现方式可以有多种，下面描述两种可能的实现方式。
(1)实现方式1
AMF网元可以主动向PGW-C+SMF发送目标小区的信息。比如，AMF网元获取到目标小区的信息后，若确定终端设备加入了第一业务的多播会话，则可以确定与第一业务关联的第一PDU会话，第一PDU会话为终端设备的PDU会话，并向PGW-C+SMF发送会话上下文请求消息，会话上下文请求消息可以包括目标小区的信息，会话上下文请求消息用于请求第一PDU会话的上下文。需要说明的是，在其它可能的实施例中，AMF网元也可以不判断终端设备是否加入了第一业务的多播会话，也不确定第一业务关联的PDU会话，AMF网元可以给每个需要切换的PDU会话对应的PGW-C+SMF发送目标小区的信息。
其中，AMF网元确定与第一业务关联的第一PDU会话的方式可以有多种。比如，PGW-C+SMF在将终端设备加入第一业务的多播会话的过程中，可以通过第一PDU会话将第一业务的多播会话的标识发送给AMF网元，第一业务的多播会话的标识可以是指第一业务以第三传输方式(即5MBS传输方式)传输时所对应的标识；AMF网元接收到第一业务的多播会话的标识后，可以建立第一业务与第一PDU会话之间的关联关系，进而根据该关联关系，可以确定与第一业务关联的第一PDU会话。又比如，AMF网元可以获取第一业务的单网络切片选择辅助信息(single network slice selection assistance information， S-NSSAI)和/或数据网络名称(data network name，DNN)，并确定第一业务的S-NSSAI和/或DNN对应的PDU会话为与第一业务关联的第一PDU会话。示例性地，AMF网元可以从UDM网元获取第一业务的S-NSSAI和/或DNN。
此外，在实现方式1中，AMF网元获取到目标小区的信息后，可以无条件地向PGW-C+SMF发送目标小区的信息；也就是说，只要AMF网元获取到目标小区的信息，便可以向PGW-C+SMF发送目标小区的信息。或者，AMF网元获取到目标小区的信息后，也可以有条件地向PGW-C+SMF发送目标小区的信息；也就是说，AMF网元获取到目标小区的信息后，可以判断是否满足预设条件，若满足，则可以向PGW-C+SMF发送目标小区的信息，若不满足，则可以不再向PGW-C+SMF发送目标小区的信息。比如，AMF网元获取到目标小区的信息后，可以判断第一业务是否支持通过4G网络进行传输，若支持，则可以向PGW-C+SMF发送目标小区的信息，若不支持，则可以不再向PGW-C+SMF发送目标小区的信息。其中，AMF网元判断第一业务是否支持通过4G网络进行传输的具体实现可以有多种，比如AMF网元可以获取第一业务的签约数据，进而根据签约数据确定第一业务是否支持通过4G网络进行传输。
实现方式2
AMF网元可以被动地向PGW-C+SMF发送目标小区的信息。比如，AMF网元可以基于PGW-C+SMF的请求或指示，向PGW-C+SMF发送目标小区的信息。
示例性地，AMF网元接收到源接入网网元发送的切换请求后，可以向PGW-C+SMF发送会话上下文请求消息，会话上下文请求消息用于请求终端设备的第一PDU会话的上下文，会话上下文请求消息中不包括目标小区的信息。相应地，PGW-C+SMF接收到会话上下文请求消息后，可以从AMF网元获取终端设备的目标小区的信息。作为一种可能的实现，PGW-C+SMF可以确定第一业务是否支持通过4G网络进行传输，若支持，则可以从AMF网元获取终端设备的目标小区的信息，若不支持，则可以不再从AMF网元获取终端设备的目标小区的信息。
需要说明的是，PGW-C+SMF也可以是在接收到目标小区的信息后，再获取第一业务的服务区域信息，也就是说，S501可以在S502之后执行。
S503，PGW-C+SMF根据目标小区的信息，判断目标小区是否在服务区域内，若目标小区不在服务区域内，则执行S504a和S505a，若目标小区在服务区域内，则执行S504b和S505b。
此处，PGW-C+SMF可以根据目标小区的信息和服务区域信息，确定目标小区是否在服务区域内。比如，目标小区的信息包括目标小区对应的TAI(比如为TAI-1)，服务区域信息包括服务区域对应的TAI(比如包括TAI-1、TAI-2、TAI-3)，由于服务区域对应的TAI包括目标小区对应的TAI，则可以确定目标小区在服务区域内。
需要说明的是，若PGW-C+SMF未能从AMF网元获取到目标小区的信息(比如AMF网元不支持向PGW-C+SMF发送目标小区的信息)，则可以认为目标小区不在服务区域内。
S504a，PGW-C+SMF发送信息1，信息1用于建立传输路径1，传输路径1用于在4G网络中以第二传输方式向终端设备发送第一业务的数据。
此处，传输路径1(即第二传输方式对应的传输路径)可以为：AS→MB-UPF网元→PGW-U+UPF→SGW→eNB→终端设备。传输路径1中包括终端设备与PGW-U+UPF之间的单播承载，信息1用于建立传输路径1可以是指，信息1用于建立传输路径1所包括 的单播承载。在一个示例中，信息1可以包括单播承载的上下文，比如单播承载的QoS信息、单播承载的标识等。
在PGW-C+SMF发送信息1之前，PGW-C+SMF可以获取信息1。比如PGW-C+SMF可以获取第一业务的组播QoS流的信息，进而根据第一业务的组播QoS流的信息，确定第一业务的单播QoS流的信息；进一步地，SMF网元可以将第一业务的单播QoS流映射到单播承载，并获取单播承载的标识(比如可以是从AMF网元获取单播承载的标识)，从而可以得到信息1。或者，PGW-C+SMF也可以直接将第一业务的组播QoS流映射到单播承载，并获取单播承载的标识，从而得到信息1。
可以理解地，本申请实施例对PGW-C+SMF获取信息1的时机不做限定，比如PGW-C+SMF可以是在将终端设备加入第一业务的多播会话的过程中，获取信息1；或者PGW-C+SMF也可以是在确定目标小区不在服务区域内后，获取信息1。
示例性地，PGW-C+SMF发送信息1可以是指，PGW-C+SMF向AMF网元发送信息1。比如PGW-C+SMF向AMF网元发送会话上下文响应消息，会话上下文响应消息中包括第一PDU会话的上下文，第一PDU会话的上下文包括信息1。相应地，AMF网元接收到信息1后，可以在切换流程中向4G网络中的MME发送信息1，进而MME可以根据信息1，在4G网络中建立单播承载。
此外，若终端设备在切换到4G网络前，是通过5G网络的第三传输方式(即5MBS传输方式)的共享MBS传输方式接收第一业务的数据，则PGW-C+SMF还可以触发建立从MB-UPF网元到PGW-U+UPF的隧道，并通知PGW-U+UPF在从MB-UPF网元接收到第一业务的数据时，将第一业务的数据映射到上述单播承载中发送给终端设备。
具体来说，在一个示例中，在终端设备切换到4G网络后，PGW-C+SMF可以接收会话更新请求消息(例如，从SGW或MME接收会话更新请求消息)；在接收到会话更新请求消息后，PGW-C+SMF可以通知PGW-U+UPF在从MB-UPF网元接收到第一业务的数据时，将第一业务的数据映射到上述单播承载中发送给终端设备。若MB-UPF网元与PGW-U+UPF间的隧道还未建立，则PGW-C+SMF还可以触发建立MB-UPF到PGW-U+UPF的隧道。
S505a，在终端设备切换到4G网络后，AS可以通过传输路径1向终端设备发送第一业务的数据；相应地，终端设备通过传输路径1接收第一业务的数据。
S504b，PGW-C+SMF不发送信息1。
此处，PGW-C+SMF不发送信息1可以是指，PGW-C+SMF可以不向AMF网元发送信息1。比如PGW-C+SMF向AMF网元发送会话上下文响应消息，会话上下文响应消息中包括第一PDU会话的上下文，第一PDU会话的上下文不包括信息1。由于AMF网元未接收到信息1，因此，AMF网元在切换流程中可以不向4G网络中的MME发送信息1，进而MME可以不再为终端设备建立单播承载。
S505b，在终端设备切换到4G网络后，AS可以通过传输路径2向终端设备发送第一业务的数据；相应地，终端设备通过传输路径2接收第一业务的数据。
此处，传输路径2(即第一传输方式对应的传输路径)可以为：AS→MBSF网元→MBMS-GW→eNB→终端设备。
由于目标小区在服务区域内，因此，目标小区的广播信道中广播的信息可以包括第一业务对应的TMGI和第一业务的配置信息。终端设备切换到目标小区后，可以根据预先获取的第一业务对应的TMGI来监听目标小区的广播信道，进而可以根据第一业务的配置信 息通过传输路径2来接收第一业务的数据。其中，第一业务的配置信息可以用于确定承载第一业务的数据的资源。示例性地，第一业务对应的TMGI可以是终端设备预先从AS获取到的，或者也可以是终端设备预先从MBSF网元获取到的，具体不做限定。
示例性地，由于终端设备可以通过传输路径2接收第一业务的数据，因此，PGW-C+SMF可以释放或删除5G网络中用于向终端设备发送第一业务的数据的资源。比如PGW-C+SMF可以删除第一业务的多播信息，例如，删除第一业务的多播会话的标识、多播QoS流的信息，可选地，若存在多播QoS流对应的单播QoS流，PGW-C+SMF也可以删除与单播QoS流的信息。进一步地，若终端设备是第一业务的多播会话中的最后一个终端设备，则PGW-C+SMF还可以删除与MB-SMF网元之间的会话。若在终端设备切换到4G网络前，终端设备是通过第三传输方式中的单独MBS传输方式接收第一业务的数据，则PGW-C+SMF还可以删除PGW-U+UPF的配置，使得PGW-U+UPF停止将第一业务的数据拷贝到第一PDU会话对应的隧道中发送；若终端设备是通过PGW-U+UPF以单独MBS传输方式接收第一业务的数据的最后一个终端设备，则PGW-C+SMF还可以通知MB-SMF网元删除MB-UPF网元到PGW-U+UPF的隧道。
采用上述方法，PGW-C+SMF可以根据第一业务的服务区域信息和终端设备的目标小区的信息，确定目标小区是否在服务区域内，进而根据目标小区是否在服务区域内进行不同的处理。比如若目标小区不在服务区域内，则PGW-C+SMF可以发送信息1，进而AS可以在4G网络以第二传输方式向终端设备发送第一业务的数据，若目标小区在服务区域内，则PGW-C+SMF可以不发送信息1，进而AS可以在4G网络以第一传输方式(即eMBMS传输方式)向终端设备发送第一业务的数据。
需要说明的是，上述实施例一所描述的流程中，若目标小区在服务区域内，则PGW-C+SMF可以不发送信息1。在其它可能的实现中，若目标小区在服务区域内，则PGW-C+SMF也可以发送信息1，进而AS可以在4G网络以第二传输方式向终端设备发送第一业务的数据，本申请实施例对目标小区在服务区域内时的相关实现可以不做限定。
实施例二
在实施例二中，将以图3所示意的网络架构为例，描述通信方法的一种可能的实现流程。
图6为本申请实施例二提供的通信方法所对应的流程示意图。如图6所示，该流程可以包括：
S601，AMF网元获取第一业务的服务区域信息，服务区域信息用于指示第一业务在4G网络中以第一传输方式(即eMBMS传输方式)进行传输的服务区域。
此处，AMF网元获取第一业务的服务区域信息的实现方式可以有多种，比如AMF网元可以接收来自核心网网元2的第一业务的服务区域信息，核心网网元2可以包括以下任一项：PGW-C+SMF、MBSF网元、MB-SMF网元、NEF网元、UDM网元、UDR网元。
示例性地，MBSF网元/NEF网元可以接收AS发送的第一业务的播放范围信息，进而根据第一业务的播放范围信息确定第一业务的服务区域信息。进一步地，比如，MBSF网元/NEF网元可以将第一业务的服务区域信息发送给AMF网元；又比如，MBSF网元/NEF网元可以将第一业务的服务区域信息发送给PGW-C+SMF，进而由PGW-C+SMF发送给AMF网元；又比如，MBSF网元/NEF网元可以将第一业务的服务区域信息发送给MB-SMF 网元，进而MB-SMF网元发送给AMF网元；又比如，MBSF网元/NEF网元可以将第一业务的服务区域信息保存在UDR网元/UDM网元中，进而由UDR网元/UDM网元发送给AMF网元；又比如，MBSF网元/NEF网元可以将第一业务的服务区域信息保存在UDR网元/UDM网元中，MB-SMF网元从UDR网元/UDM网元获取第一业务的服务区域信息，进而发送给AMF网元。
S602，AMF网元根据目标小区的信息，判断目标小区是否在服务区域内，若目标小区不在服务区域，则执行S603a至S606a，若终端设备的目标小区在服务区域，则执行S603b至S605b，或者执行S603c至S605c。
此处，AMF网元可以获取目标小区的信息，进而根据目标小区的信息和服务区域信息，确定目标小区是否在服务区域内。比如，当终端设备由5G网络移动至4G网络时，终端设备的源接入网网元(即5G网络中的gNB)可以向AMF网元发送切换请求，切换请求包括目标小区的信息。进而，AMF网元可以从切换请求中获取目标小区的信息。
S603a，AMF网元向PGW-C+SMF发送会话上下文请求消息，会话上下文请求消息包括信息2，信息2用于指示在4G网络中以第二传输方式向终端设备发送第一业务的数据。
示例性地，AMF网元若确定终端设备加入了第一业务的多播会话，则可以确定与第一业务关联的第一PDU会话，第一PDU会话为终端设备的PDU会话，进而向PGW-C+SMF发送会话上下文请求消息，会话上下文请求消息用于请求第一PDU会话的上下文。其中，AMF网元确定与第一业务关联的第一PDU会话的相关实现可以参见实施例一中的描述。
需要说明的是，信息2用于指示在4G网络中以第二传输方式向终端设备发送第一业务的数据，也可以替换为其它可能的描述，比如可以替换为，信息2用于指示终端设备的目标小区不在服务区域内，或者信息2用于指示获取信息1，具体不做限定。
S604a，PGW-C+SMF接收会话上下文请求消息，并根据信息2，向AMF网元发送第一PDU会话的上下文，第一PDU会话的上下文包括信息1。
S605a，AMF网元发送信息1，信息1用于建立传输路径1，传输路径1用于在4G网络中以第二传输方式向终端设备发送第一业务的数据。其中，传输路径1可以参见实施例一中的描述。
示例性地，AMF网元发送信息1，可以是指，AMF网元在切换流程中向4G网络中的MME发送信息1，进而MME可以根据信息1，在4G网络中建立传输路径1所包括的单播承载。
S606a，在终端设备切换到4G网络后，AS通过传输路径1向终端设备发送第一业务的数据；相应地，终端设备通过传输路径1接收第一业务的数据。
S603b，AMF网元向PGW-C+SMF发送会话上下文请求消息，会话上下文请求消息不包括信息2或者会话上下文请求消息包括信息3，信息3用于指示在4G网络中以第一传输方式(即eMBMS传输方式)向终端设备发送第一业务的数据。
需要说明的是，信息3用于指示在4G网络中以第一传输方式向终端设备发送第一业务的数据，也可以替换为其它可能的描述，比如可以替换为，信息3用于指示终端设备的目标小区在服务区域内，或者信息3用于指示不获取信息1，具体不做限定。
S604b，PGW-C+SMF向AMF网元发送第一PDU会话的上下文，第一PDU会话的上下文不包括信息1；相应地，AMF网元可以接收第一PDU会话的上下文。
此种情形下，由于AMF网元未接收到信息1，因此，AMF网元可以不发送信息1。AMF网元不发送信息1，可以是指，AMF在切换流程中不向4G网络中的MME发送信息1，进而 MME可以不再为终端设备建立单播承载。
示例性地，PGW-C+SMF可以释放或删除5G网络中用于向终端设备发送第一业务的数据的资源，具体可以参见实施例一中的描述。
S605b，在终端设备切换到4G网络后，AS通过传输路径2向终端设备发送第一业务的数据；相应地，终端设备通过传输路径2接收第一业务的数据。其中，传输路径2(即第一传输方式对应的传输路径)可以参见实施例一中的描述。
需要说明的是，上述所描述的流程中，AMF网元若确定目标小区不在服务区域内，则向PGW-C+SMF发送的会话上下文请求消息中可以携带信息2，进而PGW-C+SMF可以向AMF网元发送信息1；AMF网元接收到信息1后，可以发送信息1。或者，AMF网元若确定目标小区在服务区域内，则向PGW-C+SMF发送的会话上下文请求消息中可以不携带信息2或者携带信息3，进而PGW-C+SMF可以不向AMF网元发送信息1；由于AMF网元未接收到信息1，因此AMF网元可以不发送信息1。在其它可能的实施例中，AMF网元可以向PGW-C+SMF发送会话上下文请求消息，PGW-C+SMF接收到会话上下文请求消息，便会向AMF网元发送信息1；AMF网元接收到信息1后，可以根据目标小区是否在服务区域内，来决定是否发送信息1。
S603c，AMF网元向终端设备的源接入网网元(即5G网络中的gNB)发送信息4，信息4用于将所述终端设备重定向至目标小区。
S604c，gNB将终端设备重定向至目标小区。
此处，gNB可以通知终端设备接入目标小区，相应地，终端设备可以通过目标小区接入4G网络。进一步地，在终端接入4G网络的过程中(例如，通过跟踪区更新流程接入4G网络)，MME向AMF网元请求终端设备的上下文，进而AMF网元可以根据MME的请求，向PGW-C+SMF发送会话上下文请求消息，会话上下文请求消息可以不携带信息2或者携带信息3，进而PGW-C+SMF可以不向AMF网元发送信息1，AMF网元也可以不向MME发送信息1，从而可以不在4G网络中建立单播承载。
示例性地，PGW-C+SMF在接收到会话上下文请求消息后，可以释放或删除5G网络中用于向终端设备发送第一业务的资源，具体可以参见实施例一中的描述。
S605c，AS通过传输路径2向终端设备发送第一业务的数据；相应地，终端设备通过传输路径2接收第一业务的数据。
此处，由于目标小区在服务区域内，因此，目标小区的广播信道中广播的信息可以包括第一业务对应的TMGI和第一业务的配置信息。终端设备接入目标小区后，可以根据预先获取的第一业务对应的TMGI来监听目标小区的广播信道，进而可以根据第一业务的配置信息通过传输路径2来接收第一业务的数据。
采用上述方法，AMF网元可以根据第一业务的服务区域信息和终端设备的目标小区的信息，确定目标小区是否在服务区域内，进而根据目标小区是否在服务区域内进行不同的处理。比如若目标小区不在服务区域内，则AMF网元可以发送信息1，进而AS可以在4G网络以第二传输方式向终端设备发送第一业务的数据，若目标小区在服务区域内，则AMF网元可以不发送信息1，进而AS可以在4G网络以第一传输方式(即eMBMS传输方式)向终端设备发送第一业务的数据。
实施例三
在实施例三中，将以图3所示意的网络架构为例，描述通信方法的一种可能的实现流程。
图7为本申请实施例三提供的通信方法所对应的流程示意图。如图7所示，该流程可以包括：
S701，终端设备的源接入网网元(即5G网络中的gNB)获取第一业务的服务区域信息，服务区域信息用于指示第一业务在4G网络中以第一传输方式(即eMBMS传输方式)进行传输的服务区域。
此处，gNB获取第一业务的服务区域信息的方式可以有多种。下面描述两种可能的实现方式。
(1)实现方式1
核心网网元3可以向gNB发送第一业务的服务区域信息，进而gNB可以接收第一业务的服务区域信息。其中，核心网网元3可以包括以下任一项：PGW-C+SMF、AMF网元、MB-SMF网元。
示例性地，PGW-C+SMF或AMF网元可以在请求gNB将终端设备加入第一业务的多播会话时，将第一业务的服务区域信息发送给gNB。又比如，MB-SMF可以在gNB建立第一业务的多播会话时，将第一业务的服务区域信息发送给gNB；具体来说，gNB在接收到将终端设备加入第一业务的多播会话的请求后，可以向MB-SMF发送请求消息以便建立第一业务的多播会话，进而MB-SMF可通过响应消息将第一业务的服务区域信息发送给gNB。其中，PGW-C+SMF、AMF网元或MB-SMF网元获取第一业务的服务区域信息的实现，可以参见实施例一或实施例二中的描述。
示例性地，当由AMF网元向gNB发送第一业务的服务区域信息时，AMF可以先对第一业务的服务区域信息进行裁剪，得到裁剪后的服务区域信息，并将裁剪后的服务区域信息发送给gNB。其中，裁剪后的服务区域信息可以用于指示支持第一业务在4G网络中以eMBMS传输方式进行传输的第一服务区域，第一服务区域可以为服务区域内与gNB相邻的区域。采用该种方式，可以减少发送给gNB的信息大小，从而节省传输资源。
(2)实现方式2
终端设备可以向gNB发送第一业务的服务区域信息，进而gNB可以接收第一业务的服务区域信息。比如，终端设备可以向gNB发送无线资源控制(radio resource control，RRC)消息，RRC消息包括第一业务的服务区域信息。
S702，gNB判断终端设备的目标小区是否在服务区域内，若目标小区不在服务区域内，则执行S703a至S704a；若目标小区在服务区域内，则执行S703b至S704b，或者执行S703c至S704c。
S703a，gNB发送信息5，信息5用于指示在4G网络中以第二传输方式向终端设备发送第一业务的数据，或者，信息5用于指示为第一业务在4G网络分配无线资源，该无线资源用于在4G网络中以第二传输方式向终端设备发送第一业务的数据，或者，信息5用于指示将第一业务切换到4G网络(比如可以是指在切换流程中将第一业务切换到4G网络)。
在一种可能的实现方式中，gNB可以向AMF网元发送信息5(比如携带在切换请求中)，AMF网元接收到信息5后，可以根据信息5得到信息2(信息2可以参见上述实施例二中的描述)，并向PGW-C+SMF发送会话上下文请求消息，会话上下文请求消息中携带信息2。进而PGW-C+SMF可以向AMF网元发送信息1。AMF网元接收到信息1后， 可以在切换流程中向4G网络中的MME发送信息1，进而MME可以根据信息1，在4G网络中建立传输路径1所包括的单播承载。
在又一种可能的实现方式中，gNB可以通过AMF网元向PGW-C+SMF发送信息5(此种情形下，AMF网元起转发作用，可以不解析信息5)，比如信息5可以承载于N2SM消息中。进而，PGW-C+SMF在接收到AMF网元发送的会话上下文请求消息(会话上下文请求消息中包括信息5)后，可以根据信息5，向AMF网元发送信息1。AMF网元接收到信息1后，可以在切换流程中向4G网络中的MME发送信息1，进而MME可以根据信息1，在4G网络中建立传输路径1所包括的单播承载。
示例性地，信息5可以包括第一业务的多播会话的标识和/或指示信息(比如该指示信息可以指示4G网络的第二传输方式)。比如，当第一PDU会话只关联第一业务时，信息5可以包括指示信息，而不包括第一业务的多播会话的标识。
S704a，在终端设备切换到4G网络后，AS通过传输路径1向终端设备发送第一业务的数据；相应地，终端设备通过传输路径1接收第一业务的数据。
S703b，gNB发送信息6，信息6用于在4G网络中以第一传输方式(即eMBMS传输方式)向终端设备发送第一业务的数据，或者，信息6用于指示不为第一业务在4G网络分配无线资源，该无线资源用于在4G网络中以第二传输方式向终端设备发送第一业务的数据，或者，信息6用于指示不将第一业务切换到4G网络(比如可以是指在切换流程中不将第一业务切换到4G网络)。
在一种可能的实现方式中，gNB可以向AMF网元发送信息6(比如携带在切换请求中)，AMF网元接收到信息6后，可以根据信息6得到信息3，并向PGW-C+SMF发送会话上下文请求消息，会话上下文请求消息中携带信息3，进而PGW-C+SMF可以不向AMF网元发送信息1。由于AMF网元未接收到信息1，因此可以在切换流程中不向4G网络中的MME发送信息1，进而MME可以不在4G网络中建立传输路径1所包括的单播承载。
在又一种可能的实现方式中，gNB可以通过AMF网元向PGW-C+SMF发送信息6(此种情形下，AMF网元起转发作用，可以不解析信息6)，比如信息6可以承载于N2SM消息中。进而，PGW-C+SMF在接收到AMF网元发送的会话上下文请求消息(会话上下文请求消息中包括信息5)后，可以根据信息6，不向AMF网元发送信息1。由于AMF网元未接收到信息1，因此可以在切换流程中不向4G网络中的MME发送信息1，进而MME可以不在4G网络中建立传输路径1所包括的单播承载。
示例性地，信息6可以包括第一业务的多播会话的标识和/或指示信息(比如该指示信息可以指示4G网络的第一传输方式)。比如，当第一PDU会话只关联第一业务时，信息6可以包括指示信息，而不包括第一业务的多播会话的标识。
示例性地，在上述两种实现方式中，PGW-C+SMF还可以释放或删除5G网络中用于向终端设备发送第一业务的数据的资源，具体可以参见实施例一中的描述。
S704b，在终端设备切换到4G网络后，AS通过传输路径2向终端设备发送第一业务的数据；相应地，终端设备通过传输路径2接收第一业务的数据。
S703c，gNB将终端设备重定向至目标小区。
示例性地，S703c的相关实现可以参见实施例二中S604c的描述。
S704c，AS通过传输路径2向终端设备发送第一业务的数据；相应地，终端设备通过传输路径2接收第一业务的数据。
采用上述方法，终端设备的源接入网网元可以根据第一业务的服务区域信息和终端设备的目标小区的信息，确定目标小区是否在服务区域内，进而根据目标小区是否在服务区域内进行不同的处理。比如若目标小区不在服务区域内，则源接入网网元可以发送信息5，进而AS可以在4G网络以第二传输方式向终端设备发送第一业务的数据，若目标小区在服务区域内，则源接入网网元可以将终端设备重定向至目标小区，或者发送信息6，进而AS可以在4G网络以第一传输方式(即eMBMS传输方式)向终端设备发送第一业务的数据。
实施例四和实施例五所适用的场景可以为：比如，在图3所示意的网络架构(4G网络和5G网络共存)中，终端设备由4G网络移动至5G网络，其中在终端设备由4G网络移动至5G网络之前，终端设备可以处于连接态，进而终端设备可以是通过切换流程接入5G网络；或者，在终端设备由4G网络移动至5G网络之前，终端设备可以处于空闲态，进而终端设备可以是从空闲态接入5G网络。又比如，在图2所示意的网络架构中，终端设备可以是初次接入5G网络。
当终端设备接入5G网络后，由于gNB不会广播第一业务的TMGI以及第一业务的配置信息(4G网络中的eNB可以广播第一业务的TMGI以及第一业务的配置信息)，因此，终端设备需要加入第一业务的多播会话，以便获取第一业务的配置信息，进而根据第一业务的配置信息来接收第一业务的数据。
然而，由于5G网络中可能存在一些PLMN不支持以5MBS传输方式发送第一业务的数据，但终端设备并不知晓当前接入的PLMN是否支持以5MBS传输方式发送第一业务的数据，从而导致终端设备无法决定是否加入第一业务的多播会话。
基于此，本申请提供实施例四和实施例五，用于确定终端设备当前接入的PLMN是否支持以5MBS传输方式发送第一业务的数据，从而可以在终端设备接入5G网络后，通过合理的方式向终端设备发送第一业务的数据。
实施例四
在实施例四中，将以图3所示意的网络架构为例，描述通信方法的一种可能的实现流程。需要说明的是，实施例四也可以适用于图2所示意的网络架构。
图8为本申请实施例四提供的通信方法所对应的流程示意图。如图8所示，该流程可以包括：
S801，终端设备获取信息7，信息7用于指示支持以第三传输方式(即5MBS传输方式)发送第一业务的数据的网络。
示例性地，信息7可以包括一个或多个网络的标识，一个或多个网络支持以5MBS传输方式发送第一业务的数据。其中，一个或多个网络可以为5G网络中的一个或多个PLMN，一个或多个PLMN包括第一PLMN。可选地，信息7还可以包括一个或多个网络中的每个网络对应的DNN和/或S-NSSAI。
终端设备获取信息7的方式可以有多种，比如，终端设备可以接收AS或者MBSF网元发送的第一业务的业务通告，业务通告中包括信息7。
S802，终端设备接入5G网络的第一PLMN。
此处，终端设备接入5G网络的第一PLMN，可以包括如下几种情形。情形1，比如在图3所示意的网络架构(当4G网络和5G网络共存)中，终端设备由4G网络移动至5G 网络，其中在终端设备由4G网络移动至5G网络之前，终端设备可以处于连接态，进而终端设备可以是通过切换流程接入5G网络的第一PLMN；或者，在终端设备由4G网络移动至5G网络之前，终端设备可以处于空闲态，进而终端设备可以是从空闲态接入5G网络的第一PLMN。情形2，比如在图2所示意的网络架构中，终端设备初次接入5G网络的第一PLMN。
S803，终端设备根据信息7，向第一PLMN中的网元(比如PGW-C+SMF)发送加入请求，加入请求用于请求加入第一业务的多播会话，或者，加入请求用于请求在第二网络中以5MBS传输方式向终端设备发送第一业务的数据。
示例性地，终端设备可以通过终端设备的第一PDU会话向第一PLMN中的网元发送加入请求，第一PDU会话对应的DNN和/或S-NSSAI与第一PLMN对应的DNN和/或S-NSSAI相同。终端设备可以根据第一PLMN对应的DNN和/或S-NSSAI确定第一PDU会话。
S804，AS通过传输路径3(即第三传输方式对应的传输路径)向终端设备发送第一业务的数据；相应地，终端设备通过传输路径3接收第一业务的数据。
此处，若终端设备接入的gNB支持5MBS，则采用第三传输方式中的共享MBS传输模式向终端设备发送第一业务的数据，对应的传输路径3可以为：AS→MB-UPF→gNB→终端设备。若终端设备接入的gNB不支持5G MBS，则采用第三传输方式中的单独MBS传输模式向终端设备发送第一业务的数据，对应的传输路径3可以为：AS→MB-UPF→PGW-U+UPF→gNB→终端设备。
采用上述方法，终端设备可以根据信息7确定终端设备接入的网络是否支持以5MBS传输方式发送第一业务的数据，若支持，则终端设备可以发送加入请求，以加入第一业务的多播会话，若不支持，则终端设备可以不发送加入请求，从而使得终端设备在接入5G网络后，可以通过上述判断确定是否发送加入请求，以便通过合理的方式接收第一业务的数据。
实施例五
在实施例五中，将以图3所示意的网络架构为例，描述通信方法的一种可能的实现流程。需要说明的是，实施例五也可以适用于图2所示意的网络架构。
图9为本申请实施例五提供的通信方法所对应的流程示意图。如图9所示，该流程可以包括：
S901，MBSF网元或者AS向核心网网元4发送第一订阅请求，第一订阅请求用于请求核心网网元4在终端设备接入5G网络后发送第一通知消息。
此处，第一订阅请求可以包括终端设备的标识，终端设备的标识可以为终端设备的IP地址或者通用公共用户标识(generic public subscription identifier GPSI)。
示例性地，在图3所示意的网络架构中，核心网网元4可以为AMF网元、PGW-C+SMF或PCF网元。在图2所示意的网络架构中，核心网网元4可以为AMF网元、SMF网元或PCF网元。比如，MBSF网元或者AS可以通过NEF网元向核心网网元4发送第一订阅请求消息。
示例性地，以AS为例，AS可以在确定终端设备需要接收第一业务的数据后，向核心网网元4发送第一订阅请求。比如，终端设备可以向AS发送业务请求，业务请求用于请求接收第一业务的数据，进而AS接收到业务请求后，可以确定终端设备需要接收第一业务的数据。进一步地，终端设备可以向AS指示终端设备的能力信息，即是否支持接入4G 网络和/或5G网络，AS可基于终端的能力信息来发送第一订阅请求；比如，若终端设备的能力信息表明终端设备支持接入5G网络，则AS可以发送第一订阅请求，若终端设备的能力信息表明终端设备不支持接入5G网络，则AS可以不发送第一订阅请求。
其中，终端设备向AS发送业务请求的方式可以有多种，比如，终端设备可以通过终端设备的第一会话向AS发送业务请求。第一会话可以为终端设备的PDU会话或者终端设备的PDN连接。
S902，终端设备接入5G网络。
此处，终端设备接入5G网络，可以包括如下几种情形。情形1，比如在图3所示意的网络架构(当4G网络和5G网络共存)中，终端设备由4G网络移动至5G网络，其中在终端设备由4G网络移动至5G网络之前，终端设备可以处于连接态，进而终端设备可以是通过切换流程接入5G网络；或者，在终端设备由4G网络移动至5G网络之前，终端设备可以处于空闲态，进而终端设备可以是从空闲态接入5G网络。情形2，比如在图2所示意的网络架构中，终端设备初次接入5G网络。
需要说明的是，上述S901可以在S902之前执行，或者S901也可以在S902之后执行，具体不做限定。
S903，核心网网元4向MBSF网元或者AS发送第一通知消息，第一通知消息用于通知终端设备接入5G网络；相应地，MBSF网元或者AS可以接收第一通知消息。
比如，终端设备接入了5G网络的第二PLMN，则第一通知消息可以包括第二PLMN的标识。
需要说明的是：若S902在S901之前执行，则S903可以是S901的响应消息，即在第一订阅请求的响应消息中通知AS终端设备接入了5G网络的第二PLMN。
S904，MBSF网元或者AS向核心网网元5发送信息8，信息8用于指示在5G网络中以第三传输方式(5MBS传输方式)向终端设备发送第一业务的数据。比如，信息8可以包括第一业务的多播会话的标识。
此处，MBSF网元或者AS接收到第一通知消息后，可以根据第二PLMN的标识确定第二PLMN是否支持以5MBS传输方式发送第一业务的数据。若支持，则MBSF网元或者AS可以向核心网网元5发送信息8，核心网网元5接收到信息8后，可以将终端设备加入第一业务的多播会话；若不支持，则MBSF网元或者AS可以不指示将终端设备加入第一业务的多播会话。
示例性地，核心网网元5可以为PCF网元或者MB-SMF网元。以AS为例，在一个示例中，AS可以通过NEF网元向核心网网元5发送信息8。在又一个示例中，AS可以通过第一业务关联的PDU会话对应的应用策略会话或应用功能会话(即AF session)向核心网网元5发送信息8。
示例性地，核心网网元5接收到来自AS的信息8后，可以通知第一业务关联的PDU会话对应的SMF网元(或PGW-C+SMF)将终端设备加入第一业务的多播会话。(1)当AS通过第一业务关联的PDU会话对应的应用策略会话向核心网网元5发送信息8时，核心网网元5为PCF网元，此时，PCF网元可通过该PDU会话对应的应用策略会话通知该PDU会话对应的SMF网元将终端设备加入第一业务的多播会话。(2)当AS通过NEF向核心网网元5发送信息8时，信息8中可携带终端设备的信息，核心网网元5可以是PCF网元或者SMF网元。例如，终端设备的信息为终端设备的IP地址，NEF网元根据终端设 备的IP地址，可确定为终端设备的IP地址对应的PDU会话服务的PCF网元或SMF网元，进而可通知为该PDU会话服务的SMF网元(直接通知或通过PCF网元通知)将终端设备加入第一业务的多播会话。
此外，在通知SMF网元将终端设备加入第一业务的多播会话时，核心网网元5可以将第一业务的多播会话的标识发送给SMF网元。其中，SMF网元将终端设备加入第一业务的多播会话的过程可参考现有技术，不再赘述。
S905，AS通过传输路径3向终端设备发送第一业务的数据；相应地，终端设备通过传输路径3接收第一业务的数据。
示例性地，S905的实现可以参见实施例四S804的相关描述。
采用上述方法，可以由AS来判断终端设备接入的网络是否支持以5MBS传输方式发送第一业务的数据，若支持，则可以指示核心网网元将终端设备加入第一业务的多播会话，若不支持，则可以不指示将终端设备加入第一业务的多播会话，从而使得在终端设备在接入5G网络后，可以通过合理的方式向终端设备发送第一业务的数据。
实施例六所适用的场景可以包括前述实施例一至实施例三所适用的场景，具体可以参见上文的描述。
实施例六
在实施例六中，将以图3所示意的网络架构为例，描述通信方法的一种可能的实现流程。
图10为本申请实施例六提供的通信方法所对应的流程示意图。如图10所示，该流程可以包括：
S1001，MBSF网元或者AS向核心网网元6发送第二订阅请求，第二订阅请求用于请求核心网网元6在终端设备接入4G网络后发送第二通知消息。
此处，第二订阅请求可以包括终端设备的标识，终端设备的标识可以为终端设备的IP地址或者GPSI。
示例性地，在图3所示意的网络架构中，核心网网元6可以为MME网元、PGW-C+SMF或PCF网元。在图1所示意的网络架构中，核心网网元6可以为MME网元或PCF网元。
示例性地，以AS为例，AS可以在确定终端设备需要接收第一业务的数据后，向核心网网元6发送第二订阅请求。比如，终端设备可以向AS发送业务请求，业务请求用于请求接收第一业务的数据，进而AS接收到业务请求后，可以确定终端设备需要接收第一业务的数据。进一步地，终端设备可以向AS指示终端设备的能力信息，即是否支持接入4G网络和/或5G网络，AS可基于终端的能力信息来发送第二订阅请求；比如，若终端设备的能力信息表明终端设备支持接入4G网络，则AS可以发送第二订阅请求，若终端设备的能力信息表明终端设备不支持接入4G网络，则AS可以不发送第二订阅请求。其中，终端设备向AS发送业务请求的方式可以参见实施例一中的描述。
S1002，终端设备接入4G网络。
例如，终端设备在由5G网络移动至4G网络时，可以通过附着流程或者跟踪区更新流程接入4G网络，或者，也可以通过切换流程切换到4G网络。
需要说明的是，上述S1001可以在S1002之前执行，或者S1001也可以在S1002之后执行，具体不做限定。
S1003，核心网网元6向MBSF网元或者AS发送第二通知消息，第二通知消息用于通知终端设备接入4G网络；相应地，MBSF网元或者AS可以接收第二通知消息。
需要说明的是：若S1002在S1001之前执行，S1003可以是S1001的响应消息，即在第二订阅请求的响应消息中通知AS终端设备接入了4G网络。
S1004，MBSF网元或者AS向核心网网元7发送信息9，信息9用于建立传输路径4(第五传输方式对应的传输路径)，传输路径4用于在4G网络中以第五传输方式向终端设备发送第一业务的数据。
此处，以第五传输方式发送第一业务的数据时，数据包的目的地址是终端设备的IP地址，传输路径4可以为：AS→PGW-U网元→SGW→eNB→终端设备。
示例性地，以AS为例，在一种可能的实现方式中，第二通知消息可以包括终端设备接入的4G网络中的小区的信息；进而，AS接收到第二通知消息后，可以根据该小区的信息，确定该小区是否支持以eMBMS传输方式发送第一业务的数据(比如确定该小区是否在支持第一业务以eMBMS传输方式进行传输的服务区域内)，若不支持，则向核心网网元7发送信息9，若支持，则可以不向核心网网元7发送信息9。
在又一种可能的实现方式中，第二订阅请求可以包括信息10，信息10用于指示在终端设备所接入的第一网络中的小区不支持以eMBMS传输方式发送第一业务的数据时发送第二通知消息。进而，AS在接收到第二通知消息后，可以向核心网网元7发送信息9。示例性地，信息10还可以包括支持第一业务以eMBMS传输方式进行传输的服务区域信息，以便核心网网元7判断终端设备接入的4G网络中的小区是否支持以eMBMS传输方式发送第一业务的数据。
示例性地，信息9可以包括第一业务以第五传输方式发送时的业务信息，比如该业务信息可以包括单播过滤规则，信息9还可以包括第一业务以第五传输方式发送时的QoS信息。以图3所示意的网络架构为例，核心网网元7可以为PGW-C+SMF，比如MBSF网元或者AS可以通过NEF网元或PCF网元向PGW-C+SMF发送业务信息，以PCF网元为例，PCF网元可以根据业务信息确定策略与计费控制(policy and charging control，PCC)规则，并将PCC规则发送给PGW-C+SMF，PCC规则中包括单播过滤规则。相应地，PGW-C+SMF接收到PCC规则后，可以根据PCC规则建立单播承载，并将单播过滤规则发送给PGW-U网元，进而PGW-U网元在从AS接收到第一业务的数据后，可以根据单播过滤规则，将第一业务的数据映射至该单播承载，并通过该单播承载发送给终端设备。其中，根据PCC规则建立单播承载可以参见现有技术的描述，这里不再赘述。
需要说明的是，在尚未建立相应的单播承载时，可以先将第一业务的数据通过缺省承载发送给终端设备，从而避免造成数据丢失，只是有少量数据可能无法得到QoS保障。
S1005，AS通过传输路径4向终端设备发送第一业务的数据，数据包的目的地址为终端设备的IP地址；相应地，终端设备通过传输路径4接收第一业务的数据。
采用上述方法，AS可以根据核心网网元的通知消息获知终端设备接入4G网络，进而在终端设备接入的小区不支持以eMBMS传输方式发送第一业务的数据后，AS可以通过第五传输方式对应的传输路径向终端设备发送第一业务的数据。
针对于上述实施例一至实施例六，需要说明的是：
(1)针对于实施例一至实施例六中所涉及的信息1至信息10中的任一信息，本 申请实施例对携带该信息的消息可以不做限定；或者，信息1至信息10中的某一(或某些)信息本身也可能为一条消息。
(2)实施例一至实施例六所描述的各个流程图的步骤编号仅为执行流程的一种示例，并不构成对步骤执行的先后顺序的限制，本申请实施例中相互之间没有时序依赖关系的步骤之间没有严格的执行顺序。此外，各个流程图中所示意的步骤并非全部是必须执行的步骤，可以根据实际需要在各个流程图的基础上增添或者删除部分步骤。
(3)上述侧重描述了实施例一至实施例六中不同实施例之间的差异之处，除差异之处的其它内容，实施例一至实施例六之间可以相互参照；此外，同一实施例中，不同实现方式或不同示例之间也可以相互参照。
(4)实施例一至实施例六可以分别单独实施，或者也可以结合实施。比如，实施例一、实施例二或实施例三可以与实施例四结合实施，此种情形下，当终端设备由5G网络移动至4G网络时，可以采用实施例一、实施例二或实施例三中的方案，当终端设备由4G网络移动至5G网络时，可以采用实施例四中的方案。又比如，实施例五可以与实施例六结合实施，此种情形下，当终端设备由5G网络移动至4G网络时，可以采用实施例六中的方案，当终端设备由4G网络移动至5G网络时，可以采用实施例五中的方案；此外，在此种情形下，第一订阅请求和第二订阅请求可以承载于同一消息，或者不同消息，具体不做限定。
上述主要从设备交互的角度对本申请实施例提供的方案进行了介绍。可以理解的是，为了实现上述功能，核心网网元、接入网网元、终端设备或应用服务器可以包括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，本申请的实施例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申请的范围。
本申请实施例可以根据上述方法示例对核心网网元、接入网网元、终端设备或应用服务器进行功能单元的划分，例如，可以对应各个功能划分各个功能单元，也可以将两个或两个以上的功能集成在一个单元中。上述集成的单元既可以采用硬件的形式实现，也可以采用软件功能单元的形式实现。
在采用集成的单元的情况下，图11示出了本申请实施例中所涉及的装置的可能的示例性框图。如图11所示，装置1100可以包括：处理单元1102和通信单元1103。处理单元1102用于对装置1100的动作进行控制管理。通信单元1103用于支持装置1100与其他设备的通信。可选地，通信单元1103也称为收发单元，可以包括接收单元和/或发送单元，分别用于执行接收和发送操作。可选的，装置1100还可以包括存储单元1101，用于存储装置1100的程序代码和/或数据。
该装置1100可以为上述实施例中的第一终端设备，或者还可以为设置在第一终端设备中的芯片。处理单元1102可以支持装置1100执行上文中各方法示例中第一终端设备的动作。或者，处理单元1102主要执行方法示例中的第一终端设备的内部动作，通信单元1103可以支持装置1100与其它设备之间的通信。
具体地，在一个实施例中，处理单元1102用于：获取第一业务的服务区域信息，所述 服务区域信息用于指示支持所述第一业务在所述第一网络中以第一传输方式进行传输的服务区域；通信单元1103用于：若所述终端设备的目标小区不在所述服务区域内，则发送第一信息，所述第一信息用于建立第一传输路径，所述第一传输路径用于在所述第一网络中以第二传输方式向所述终端设备发送所述第一业务的数据；或者，若所述目标小区在所述服务区域内，则不发送所述第一信息；其中，所述目标小区位于所述第一网络中。
在一种可能的设计中，所述服务区域信息包括以下至少一项：所述服务区域对应的公共陆地移动网络PLMN的标识；所述服务区域对应的跟踪区的标识TAI；所述服务区域对应的小区的标识。
在一种可能的设计中，装置1100可以为会话管理网元或者设置在会话管理网元中的芯片。
在一种可能的设计中，通信单元1103还用于：接收来自第一核心网网元的所述服务区域信息，所述第一核心网网元包括以下任一项：多播业务网元、多播会话管理网元、网络开放功能网元、策略控制网元、统一数据存储网元、统一数据管理网元；或者，接收来自所述终端设备的所述服务区域信息。
在一种可能的设计中，通信单元1103具体用于：接收来自所述终端设备的第一消息，所述第一消息包括所述服务区域信息；其中，所述第一消息为PDU会话建立请求消息或PDU会话修改请求消息。
在一种可能的设计中，所述第一消息还包括加入请求，所述加入请求用于请求在所述第二网络中以第三传输方式向所述终端设备发送所述第一业务的数据。
在一种可能的设计中，处理单元1102还用于：获取所述目标小区的信息；根据所述目标小区的信息，确定所述目标小区是否在所述服务区域内。
在一种可能的设计中，所述目标小区的信息包括所述目标小区对应的TAI和/或所述目标小区的标识。
在一种可能的设计中，通信单元1103还用于：接收来自移动性管理网元的所述目标小区的信息。
在一种可能的设计中，所述目标小区的信息携带在来自所述移动性管理网元的会话上下文请求消息中，所述会话上下文请求消息用于请求所述终端设备的第一PDU会话的上下文，所述第一PDU会话与所述第一业务关联。
在一种可能的设计中，处理单元1102还用于：若所述会话上下文请求消息中未携带所述目标小区的信息，则确定所述目标小区不在所述服务区域内。
在一种可能的设计中，通信单元1103还用于：接收来自移动性管理网元的会话上下文请求消息，所述会话上下文请求消息用于请求所述终端设备的第一PDU会话的上下文，所述第一PDU会话与所述第一业务关联；根据所述会话上下文请求消息，向所述移动性管理网元发送所述第一PDU会话的上下文，所述第一PDU会话的上下文包括所述第一信息。
在一种可能的设计中，通信单元1103还用于：接收来自所述移动性管理网元的会话上下文请求消息，所述会话上下文请求消息用于请求所述终端设备的第一PDU会话的上下文，所述第一PDU会话与所述第一业务关联；根据所述会话上下文请求消息，向所述移动性管理网元发送所述第一PDU会话的上下文，所述第一PDU会话的上下文不包括所述第一信息。
在一种可能的设计中，若所述终端设备的目标小区在所述服务区域内，则处理单元1102还用于：释放所述第二网络中用于向所述终端设备发送所述第一业务的资源。
在一种可能的设计中，装置1100可以为移动性管理网元或者设置在移动性管理网元中的芯片。
在一种可能的设计中，通信单元1103还用于：接收来自第二核心网网元的所述服务区域信息，所述第二核心网网元包括以下任一项：会话管理网元、多播业务网元、多播会话管理网元、网络开放功能网元、统一数据存储网元、统一数据管理网元。
在一种可能的设计中，处理单元1102还用于：获取所述目标小区的信息；根据所述目标小区的信息，确定所述目标小区是否在所述服务区域内。
在一种可能的设计中，所述目标小区的信息包括所述目标小区对应的TAI和/或所述目标小区的标识。
在一种可能的设计中，通信单元1103还用于：接收来自所述终端设备的源接入网网元的所述目标小区的信息，所述源接入网网元位于所述第二网络中。
在一种可能的设计中，通信单元1103还用于：接收来自会话管理网元的所述第一信息。
在一种可能的设计中，通信单元1103还用于：向所述会话管理网元发送第二消息，所述第二消息用于获取所述第一信息。
在一种可能的设计中，所述第二消息包括第二信息，所述第二信息用于指示在所述第一网络中以所述第二传输方式向所述终端设备发送所述第一业务的数据。
在一种可能的设计中，所述第二消息为会话上下文请求消息，所述会话上下文请求消息用于请求所述终端设备的第一PDU会话的上下文，所述第一PDU会话与所述第一业务关联。
在一种可能的设计中，处理单元1102还用于：确定与所述第一业务关联的所述第一PDU会话。
在一种可能的设计中，处理单元1102具体用于：根据所述第一业务的S-NSSAI和/或DNN，确定所述S-NSSAI和/或DNN对应的PDU会话为与所述第一业务关联的所述第一PDU会话；或者，通过所述第一PDU会话从所述会话管理网元接收所述第一业务的标识，建立所述第一业务与所述第一PDU会话的关联关系；根据所述关联关系，确定与所述第一业务关联的所述第一PDU会话。
在一种可能的设计中，若所述目标小区在所述服务区域内，则通信单元1103还用于：向所述终端设备的源接入网网元发送第三信息，所述第三信息用于将所述终端设备重定向至所述目标小区，所述源接入网网元位于所述第二网络中。
应理解以上装置中单元的划分仅仅是一种逻辑功能的划分，实际实现时可以全部或部分集成到一个物理实体上，也可以物理上分开。且装置中的单元可以全部以软件通过处理元件调用的形式实现；也可以全部以硬件的形式实现；还可以部分单元以软件通过处理元件调用的形式实现，部分单元以硬件的形式实现。例如，各个单元可以为单独设立的处理元件，也可以集成在装置的某一个芯片中实现，此外，也可以以程序的形式存储于存储器中，由装置的某一个处理元件调用并执行该单元的功能。此外这些单元全部或部分可以集成在一起，也可以独立实现。这里所述的处理元件又可以成为处理器，可以是一种具有信号的处理能力的集成电路。在实现过程中，上述方法的各操作或以上各个单元可以通过处理器元件中的硬件的集成逻辑电路实现或者以软件通过处理元件调用的形式实现。
在一个例子中，以上任一装置中的单元可以是被配置成实施以上方法的一个或多个集成电路，例如：一个或多个特定集成电路(application specific integrated circuit，ASIC)， 或，一个或多个微处理器(digital singnal processor，DSP)，或，一个或者多个现场可编程门阵列(field programmable gate array，FPGA)，或这些集成电路形式中至少两种的组合。再如，当装置中的单元可以通过处理元件调度程序的形式实现时，该处理元件可以是处理器，比如通用中央处理器(central processing unit，CPU)，或其它可以调用程序的处理器。再如，这些单元可以集成在一起，以片上系统(system-on-a-chip，SOC)的形式实现。
以上用于接收的单元是一种该装置的接口电路，用于从其它装置接收信号。例如，当该装置以芯片的方式实现时，该接收单元是该芯片用于从其它芯片或装置接收信号的接口电路。以上用于发送的单元是一种该装置的接口电路，用于向其它装置发送信号。例如，当该装置以芯片的方式实现时，该发送单元是该芯片用于向其它芯片或装置发送信号的接口电路。
参考图12，为本申请实施例提供的一种核心网网元的结构示意图。其可以为以上实施例中的会话管理网元(比如PGW-C+SMF)或移动性管理网元(比如AMF网元)，用于实现以上实施例中会话管理网元或移动性管理网元的操作。
如图12所示，核心网网元1200可包括处理器1201、存储器1202以及接口电路1203。处理器1201可用于对通信协议以及通信数据进行处理，以及对通信装置进行控制。存储器1202可用于存储程序和数据，处理器1201可基于该程序执行本申请实施例中由核心网网元执行的方法。接口电路1203可用于核心网网元1200与其他设备进行通信，该通信可以为有线通信或无线通信，该接口电路例如可以是服务化通信接口。
以上存储器1202也可以是外接于核心网网元1200的，此时核心网网元1200可包括接口电路1203以及处理器1201。以上接口电路1203也可以是外接于核心网网元1200的，此时核心网网元1200可包括存储器1202以及处理器1201。当接口电路1203以及存储器1202均外接于核心网网元1200时，通信装置1200可包括处理器1201。
图12所示的核心网网元能够实现上述方法实施例中涉及核心网网元的各个过程。图12所示的核心网网元中的各个模块的操作和/或功能，分别为了实现上述方法实施例中的相应流程。具体可参见上述方法实施例中的描述，为避免重复，此处适当省略详述描述。
参见图13，为本申请实施例提供的一种接入网网元的结构示意图，用于执行上述方法实施例中接入网网元(比如源接入网网元)的功能。接入网网元130可包括一个或多个分布式单元(distributed unit，DU)1301和一个或多个集中式单元(centralized unit，CU)1302。所述DU 1301可以包括至少一个天线13011，至少一个射频单元13012，至少一个处理器13013和至少一个存储器13014。所述DU 1301部分主要用于射频信号的收发以及射频信号与基带信号的转换，以及部分基带处理。CU1302可以包括至少一个处理器13022和至少一个存储器13021。
所述CU 1302部分主要用于进行基带处理，对接入网网元进行控制等。所述DU 1301与CU 1302可以是物理上设置在一起，也可以物理上分离设置的，即分布式基站。所述CU 1302为接入网网元的控制中心，也可以称为处理单元，主要用于完成基带处理功能。例如所述CU 1302可以用于控制接入网网元执行上述方法实施例中关于接入网网元的操作流程。
此外，可选的，接入网网元130可以包括一个或多个射频单元，一个或多个DU和一 个或多个CU。其中，DU可以包括至少一个处理器13013和至少一个存储器13014，射频单元可以包括至少一个天线13011和至少一个射频单元13012，CU可以包括至少一个处理器13022和至少一个存储器13021。
在一个实例中，所述CU1302可以由一个或多个单板构成，多个单板可以共同支持单一接入指示的无线接入网(如5G网)，也可以分别支持不同接入制式的无线接入网(如LTE网，5G网或其他网)。所述存储器13021和处理器13022可以服务于一个或多个单板。也就是说，可以每个单板上单独设置存储器和处理器。也可以是多个单板共用相同的存储器和处理器。此外每个单板上还可以设置有必要的电路。所述DU1301可以由一个或多个单板构成，多个单板可以共同支持单一接入指示的无线接入网(如5G网)，也可以分别支持不同接入制式的无线接入网(如LTE网，5G网或其他网)。所述存储器13014和处理器13013可以服务于一个或多个单板。也就是说，可以每个单板上单独设置存储器和处理器。也可以是多个单板共用相同的存储器和处理器。此外每个单板上还可以设置有必要的电路。
图13所示的接入网网元能够实现上述方法实施例中涉及接入网网元的各个过程。图13所示的接入网网元的各个模块的操作和/或功能，分别为了实现上述方法实施例中的相应流程。具体可参见上述方法实施例中的描述，为避免重复，此处适当省略详述描述。
参见图14，为本申请实施例提供的一种终端设备的结构示意图，用于实现以上实施例中终端设备的操作。如图14所示，该终端设备包括：天线1410、射频部分1420、信号处理部分1430。天线1410与射频部分1420连接。在下行方向上，射频部分1420通过天线1410接收网络设备发送的信息，将网络设备发送的信息发送给信号处理部分1430进行处理。在上行方向上，信号处理部分1430对终端设备的信息进行处理，并发送给射频部分1420，射频部分1420对终端设备的信息进行处理后经过天线1410发送给网络设备。
信号处理部分1430可以包括调制解调子系统，用于实现对数据各通信协议层的处理；还可以包括中央处理子系统，用于实现对终端设备操作系统以及应用层的处理；此外，还可以包括其它子系统，例如多媒体子系统，周边子系统等，其中多媒体子系统用于实现对终端设备相机，屏幕显示等的控制，周边子系统用于实现与其它设备的连接。调制解调子系统可以为单独设置的芯片。
调制解调子系统可以包括一个或多个处理元件1431，例如，包括一个主控CPU和其它集成电路。此外，该调制解调子系统还可以包括存储元件1432和接口电路1433。存储元件1432用于存储数据和程序，但用于执行以上方法中终端设备所执行的方法的程序可能不存储于该存储元件1432中，而是存储于调制解调子系统之外的存储器中，使用时调制解调子系统加载使用。接口电路1433用于与其它子系统通信。
该调制解调子系统可以通过芯片实现，该芯片包括至少一个处理元件和接口电路，其中处理元件用于执行以上终端设备执行的任一种方法的各个步骤，接口电路用于与其它装置通信。在一种实现中，终端设备实现以上方法中各个步骤的单元可以通过处理元件调度程序的形式实现，例如用于终端设备的装置包括处理元件和存储元件，处理元件调用存储元件存储的程序，以执行以上方法实施例中终端设备执行的方法。存储元件可以为与处理元件处于同一芯片上的存储元件，即片内存储元件。
在另一种实现中，用于执行以上方法中终端设备所执行的方法的程序可以在与处理元件处于不同芯片上的存储元件，即片外存储元件。此时，处理元件从片外存储元件调用或 加载程序于片内存储元件上，以调用并执行以上方法实施例中终端设备执行的方法。
在又一种实现中，终端设备实现以上方法中各个步骤的单元可以是被配置成一个或多个处理元件，这些处理元件设置于调制解调子系统上，这里的处理元件可以为集成电路，例如：一个或多个ASIC，或，一个或多个DSP，或，一个或者多个FPGA，或者这些类集成电路的组合。这些集成电路可以集成在一起，构成芯片。
终端设备实现以上方法中各个步骤的单元可以集成在一起，以SOC的形式实现，该SOC芯片，用于实现以上方法。该芯片内可以集成至少一个处理元件和存储元件，由处理元件调用存储元件的存储的程序的形式实现以上终端设备执行的方法；或者，该芯片内可以集成至少一个集成电路，用于实现以上终端设备执行的方法；或者，可以结合以上实现方式，部分单元的功能通过处理元件调用程序的形式实现，部分单元的功能通过集成电路的形式实现。
可见，以上用于终端设备的装置可以包括至少一个处理元件和接口电路，其中至少一个处理元件用于执行以上方法实施例所提供的任一种终端设备执行的方法。处理元件可以以第一种方式：即调用存储元件存储的程序的方式执行终端设备执行的部分或全部步骤；也可以以第二种方式：即通过处理器元件中的硬件的集成逻辑电路结合指令的方式执行终端设备执行的部分或全部步骤；当然，也可以结合第一种方式和第二种方式执行终端设备执行的部分或全部步骤。
这里的处理元件同以上描述，可以通过处理器实现，处理元件的功能可以和图11中所描述的处理单元的功能相同。示例性地，处理元件可以是通用处理器，例如CPU，还可以是被配置成实施以上方法的一个或多个集成电路，例如：一个或多个ASIC，或，一个或多个微处理器DSP，或，一个或者多个FPGA等，或这些集成电路形式中至少两种的组合。存储元件可以通过存储器实现，存储元件的功能可以和图11中所描述的存储单元的功能相同。存储元件可以通过存储器实现，存储元件的功能可以和图11中所描述的存储单元的功能相同。存储元件可以是一个存储器，也可以是多个存储器的统称。
图14所示的终端设备能够实现上述方法实施例中涉及终端设备的各个过程。图14所示的终端设备中的各个模块的操作和/或功能，分别为了实现上述方法实施例中的相应流程。具体可参见上述方法实施例中的描述，为避免重复，此处适当省略详述描述。
参考图15，为本申请实施例提供的一种应用服务器的结构示意图，用于实现以上实施例中应用服务器的操作。
如图15所示，应用服务器1500可包括处理器1501、存储器1502以及接口电路1503。处理器1501可用于对通信协议以及通信数据进行处理，以及对通信装置进行控制。存储器1502可用于存储程序和数据，处理器1501可基于该程序执行本申请实施例中由应用服务器执行的方法。接口电路1503可用于应用服务器1500与其他设备进行通信，该通信可以为有线通信或无线通信，该接口电路例如可以是服务化通信接口。
以上存储器1502也可以是外接于应用服务器1500的，此时应用服务器1500可包括接口电路1503以及处理器1501。以上接口电路1503也可以是外接于应用服务器1500的，此时应用服务器1500可包括存储器1502以及处理器1501。当接口电路1503以及存储器1502均外接于应用服务器1500时，通信装置1500可包括处理器1501。
图15所示的应用服务器能够实现上述方法实施例中涉及应用服务器的各个过程。图 15所示的应用服务器中的各个模块的操作和/或功能，分别为了实现上述方法实施例中的相应流程。具体可参见上述方法实施例中的描述，为避免重复，此处适当省略详述描述。
本申请实施例中的术语“系统”和“网络”可被互换使用。“至少一个”是指一个或者多个，“多个”是指两个或两个以上。“和/或”，描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A、同时存在A和B、单独存在B的情况，其中A，B可以是单数或者复数。字符“/”一般表示前后关联对象是一种“或”的关系。“以下至少一项(个)”或其类似表达，是指的这些项中的任意组合，包括单项(个)或复数项(个)的任意组合。例如“A，B和C中的至少一个”包括A，B，C，AB，AC，BC或ABC。以及，除非有特别说明，本申请实施例提及“第一”、“第二”等序数词是用于对多个对象进行区分，不用于限定多个对象的顺序、时序、优先级或者重要程度。
本领域内的技术人员应明白，本申请的实施例可提供为方法、系统、或计算机程序产品。因此，本申请可采用完全硬件实施例、完全软件实施例、或结合软件和硬件方面的实施例的形式。而且，本申请可采用在一个或多个其中包含有计算机可用程序代码的计算机可用存储介质(包括但不限于磁盘存储器、CD-ROM、光学存储器等)上实施的计算机程序产品的形式。
本申请是参照根据本申请的方法、设备(系统)、和计算机程序产品的流程图和/或方框图来描述的。应理解可由计算机程序指令实现流程图和/或方框图中的每一流程和/或方框、以及流程图和/或方框图中的流程和/或方框的结合。可提供这些计算机程序指令到通用计算机、专用计算机、嵌入式处理机或其他可编程数据处理设备的处理器以产生一个机器，使得通过计算机或其他可编程数据处理设备的处理器执行的指令产生用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的装置。
这些计算机程序指令也可存储在能引导计算机或其他可编程数据处理设备以特定方式工作的计算机可读存储器中，使得存储在该计算机可读存储器中的指令产生包括指令装置的制造品，该指令装置实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能。
这些计算机程序指令也可装载到计算机或其他可编程数据处理设备上，使得在计算机或其他可编程设备上执行一系列操作步骤以产生计算机实现的处理，从而在计算机或其他可编程设备上执行的指令提供用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的步骤。
显然，本领域的技术人员可以对本申请进行各种改动和变型而不脱离本申请的精神和范围。这样，倘若本申请的这些修改和变型属于本申请权利要求及其等同技术的范围之内，则本申请也意图包含这些改动和变型在内。

Claims (35)

  1. 一种通信方法，其特征在于，所述方法应用于第一通信装置，所述方法应用于终端设备由第二网络移动至第一网络，所述方法包括：
    获取第一业务的服务区域信息，所述服务区域信息用于指示支持所述第一业务在所述第一网络中以第一传输方式进行传输的服务区域；
    若所述终端设备的目标小区不在所述服务区域内，则发送第一信息，所述第一信息用于建立第一传输路径，所述第一传输路径用于在所述第一网络中以第二传输方式向所述终端设备发送所述第一业务的数据；或者，
    若所述目标小区在所述服务区域内，则不发送所述第一信息；
    其中，所述目标小区位于所述第一网络中。
  2. 根据权利要求1所述的方法，其特征在于，所述服务区域信息包括以下至少一项：
    所述服务区域对应的公共陆地移动网络PLMN的标识；
    所述服务区域对应的跟踪区的标识TAI；
    所述服务区域对应的小区的标识。
  3. 根据权利要求1或2所述的方法，其特征在于，所述第一通信装置为会话管理网元或者设置在所述会话管理网元中的芯片。
  4. 根据权利要求3所述的方法，其特征在于，所述获取第一业务的服务区域信息，包括：
    接收来自第一核心网网元的所述服务区域信息，所述第一核心网网元包括以下任一项：多播业务网元、多播会话管理网元、网络开放功能网元、策略控制网元、统一数据存储网元、统一数据管理网元；或者，
    接收来自所述终端设备的所述服务区域信息。
  5. 根据权利要求4所述的方法，其特征在于，所述接收来自所述终端设备的所述服务区域信息，包括：
    接收来自所述终端设备的第一消息，所述第一消息包括所述服务区域信息；其中，所述第一消息为协议数据单元PDU会话建立请求消息或PDU会话修改请求消息。
  6. 根据权利要求5所述的方法，其特征在于，所述第一消息还包括加入请求，所述加入请求用于请求在所述第二网络中以第三传输方式向所述终端设备发送所述第一业务的数据。
  7. 根据权利要求3至6中任一项所述的方法，其特征在于，所述方法还包括：
    获取所述目标小区的信息；
    根据所述目标小区的信息，确定所述目标小区是否在所述服务区域内。
  8. 根据权利要求7所述的方法，其特征在于，所述目标小区的信息包括所述目标小区对应的TAI和/或所述目标小区的标识。
  9. 根据权利要求7或8所述的方法，其特征在于，获取所述目标小区的信息，包括：
    接收来自移动性管理网元的所述目标小区的信息。
  10. 根据权利要求9所述的方法，其特征在于，所述目标小区的信息携带在来自所述移动性管理网元的会话上下文请求消息中，所述会话上下文请求消息用于请求所述终端设备的第一PDU会话的上下文，所述第一PDU会话与所述第一业务关联。
  11. 根据权利要求10所述的方法，其特征在于，所述方法还包括：
    若所述会话上下文请求消息中未携带所述目标小区的信息，则确定所述目标小区不在所述服务区域内。
  12. 根据权利要求3至11中任一项所述的方法，其特征在于，所述发送第一信息，包括：
    接收来自移动性管理网元的会话上下文请求消息，所述会话上下文请求消息用于请求所述终端设备的第一PDU会话的上下文，所述第一PDU会话与所述第一业务关联；
    根据所述会话上下文请求消息，向所述移动性管理网元发送所述第一PDU会话的上下文，所述第一PDU会话的上下文包括所述第一信息。
  13. 根据权利要求3至11中任一项所述的方法，其特征在于，所述不发送上下文信息，包括：
    接收来自所述移动性管理网元的会话上下文请求消息，所述会话上下文请求消息用于请求所述终端设备的第一PDU会话的上下文，所述第一PDU会话与所述第一业务关联；
    根据所述会话上下文请求消息，向所述移动性管理网元发送所述第一PDU会话的上下文，所述第一PDU会话的上下文不包括所述第一信息。
  14. 根据权利要求3至12中任一项所述的方法，其特征在于，若所述终端设备的目标小区在所述服务区域内，则所述方法还包括：
    释放所述第二网络中用于向所述终端设备发送所述第一业务的资源。
  15. 根据权利要求1或2所述的方法，其特征在于，所述第一通信装置为移动性管理网元或者设置在所述移动性管理网元中的芯片。
  16. 根据权利要求15所述的方法，其特征在于，所述获取第一业务的服务区域信息，包括：
    接收来自第二核心网网元的所述服务区域信息，所述第二核心网网元包括以下任一项：会话管理网元、多播业务网元、多播会话管理网元、网络开放功能网元、统一数据存储网元、统一数据管理网元。
  17. 根据权利要求15或16所述的方法，其特征在于，所述方法还包括：
    接收来自会话管理网元的所述第一信息。
  18. 根据权利要求17所述的方法，其特征在于，所述方法还包括：
    向所述会话管理网元发送第二消息，所述第二消息用于获取所述第一信息。
  19. 根据权利要求18所述的方法，其特征在于，所述第二消息包括第二信息，所述第二信息用于指示在所述第一网络中以所述第二传输方式向所述终端设备发送所述第一业务的数据。
  20. 根据权利要求18或19所述的方法，其特征在于，所述第二消息为会话上下文请求消息，所述会话上下文请求消息用于请求所述终端设备的第一PDU会话的上下文，所述第一PDU会话与所述第一业务关联。
  21. 根据权利要求20所述的方法，其特征在于，所述方法还包括：
    确定与所述第一业务关联的所述第一PDU会话。
  22. 根据权利要求21所述的方法，其特征在于，确定与所述第一业务关联的所述第一PDU会话，包括：
    根据所述第一业务的单网络切片选择辅助信息S-NSSAI和/或数据网络名称DNN，确定所述S-NSSAI和/或DNN对应的PDU会话为与所述第一业务关联的所述第一PDU会话；或者，
    通过所述第一PDU会话从所述会话管理网元接收所述第一业务的标识，建立所述第一 业务与所述第一PDU会话的关联关系；根据所述关联关系，确定与所述第一业务关联的所述第一PDU会话。
  23. 根据权利要求15至22中任一项所述的方法，其特征在于，若所述目标小区在所述服务区域内，则所述方法还包括：
    向所述终端设备的源接入网网元发送第三信息，所述第三信息用于将所述终端设备重定向至所述目标小区，所述源接入网网元位于所述第二网络。
  24. 一种通信方法，其特征在于，所述方法适用于第二通信装置，所述方法包括：
    获取第六信息，所述第六信息用于指示第二网络支持以第三传输方式发送第一业务的数据；
    根据所述第六信息，向所述第二网络中的网元发送加入请求，所述加入请求用于请求在所述第二网络中以所述第三传输方式向终端设备发送所述第一业务的数据。
  25. 根据权利要求24所述的方法，其特征在于，所述第六信息包括一个或多个网络的标识，所述一个或多个网络包括所述第二网络，所述一个或多个网络支持以所述第三传输方式发送所述第一业务的数据。
  26. 根据权利要求25所述的方法，其特征在于，所述一个或多个网络的标识为一个或多个PLMN的标识。
  27. 根据权利要求25或26所述的方法，其特征在于，所述第六信息还包括所述第二网络对应的DNN和/或S-NSSAI。
  28. 根据权利要求27所述的方法，其特征在于，所述方法还包括：
    通过所述终端设备的第一PDU会话向所述第二网络中的网元发送所述加入请求，所述第一PDU会话对应的DNN和/或S-NSSAI与所述第二网络对应的DNN和/或S-NSSAI相同。
  29. 根据权利要求24至28中任一项所述的方法，其特征在于，所述获取所述终端设备的第一业务的第六信息，包括：
    接收来自应用服务器的所述第六信息；或者，
    接收来自多播业务网元的所述第六信息。
  30. 一种通信装置，其特征在于，包括用于执行如权利要求1至23中任一项所述方法的模块。
  31. 一种通信装置，其特征在于，包括用于执行如权利要求24至29中任一项所述方法的模块。
  32. 一种通信装置，其特征在于，包括处理器，所述处理器和存储器耦合，所述存储器中存储有计算机程序；所述处理器用于调用所述存储器中的计算机程序，使得所述通信装置执行如权利要求1至23任一所述的方法。
  33. 一种通信装置，其特征在于，包括处理器，所述处理器和存储器耦合，所述存储器中存储有计算机程序；所述处理器用于调用所述存储器中的计算机程序，使得所述通信装置执行如权利要求24至29任一所述的方法。
  34. 一种计算机可读存储介质，其特征在于，所述存储介质中存储有计算机程序或指令，当所述计算机程序或指令被计算机执行时，实现如权利要求1至23中任一项所述的方法，或者如权利要求24至29中任一项所述的方法。
  35. 一种计算机程序产品，其特征在于，当计算机读取并执行所述计算机程序产品时，使得计算机执行如权利要求1至23中任一项所述的方法，或者如权利要求24至29中任 一项所述的方法。
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107148785A (zh) * 2014-10-27 2017-09-08 Lg 电子株式会社 在mbsfn服务边界区中提供服务连续性的方法和装置
CN109819492A (zh) * 2017-11-20 2019-05-28 华为技术有限公司 一种确定安全能力的方法和装置
CN110149665A (zh) * 2018-02-14 2019-08-20 华为技术有限公司 一种网元的选择方法及装置
CN111787542A (zh) * 2020-05-22 2020-10-16 宇龙计算机通信科技(深圳)有限公司 业务数据的传输方法、装置、存储介质及终端设备

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180242230A1 (en) * 2017-02-19 2018-08-23 Alcatel-Lucent Usa Inc. Switching between unicast service and multicast-broadcast service
US11013052B2 (en) * 2018-01-15 2021-05-18 Huawei Technologies Co., Ltd. Methods and systems for multicast-broadcast session release and modification

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107148785A (zh) * 2014-10-27 2017-09-08 Lg 电子株式会社 在mbsfn服务边界区中提供服务连续性的方法和装置
CN109819492A (zh) * 2017-11-20 2019-05-28 华为技术有限公司 一种确定安全能力的方法和装置
CN110149665A (zh) * 2018-02-14 2019-08-20 华为技术有限公司 一种网元的选择方法及装置
CN111787542A (zh) * 2020-05-22 2020-10-16 宇龙计算机通信科技(深圳)有限公司 业务数据的传输方法、装置、存储介质及终端设备

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
HUAWEI, HISILICON: "Service continuity during inter-cell mobility", 3GPP DRAFT; R2-2009340, vol. RAN WG2, 23 October 2020 (2020-10-23), pages 1 - 4, XP051942302 *

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