WO2022017527A1 - 一种数据传输方法、装置以及系统 - Google Patents

一种数据传输方法、装置以及系统 Download PDF

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Publication number
WO2022017527A1
WO2022017527A1 PCT/CN2021/108300 CN2021108300W WO2022017527A1 WO 2022017527 A1 WO2022017527 A1 WO 2022017527A1 CN 2021108300 W CN2021108300 W CN 2021108300W WO 2022017527 A1 WO2022017527 A1 WO 2022017527A1
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Prior art keywords
network element
terminal
information
management network
access network
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PCT/CN2021/108300
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English (en)
French (fr)
Inventor
李濛
杨艳梅
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华为技术有限公司
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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 KR1020237005812A priority Critical patent/KR20230041066A/ko
Priority to EP21845746.3A priority patent/EP4187941A4/en
Priority to BR112023001242A priority patent/BR112023001242A2/pt
Priority to JP2023504424A priority patent/JP2023535041A/ja
Publication of WO2022017527A1 publication Critical patent/WO2022017527A1/zh

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    • 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
    • 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
    • H04W4/08—User group management
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W68/00—User notification, e.g. alerting and paging, for incoming communication, change of service or the like
    • H04W68/005—Transmission of information for alerting of incoming communication
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W68/00—User notification, e.g. alerting and paging, for incoming communication, change of service or the like
    • H04W68/12—Inter-network notification
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/10—Connection setup
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/40—Connection management for selective distribution or broadcast
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/20—Manipulation of established connections
    • H04W76/27—Transitions between radio resource control [RRC] states

Definitions

  • the embodiments of the present application relate to the field of communication technologies, and in particular, to a data transmission method, apparatus, and system.
  • 3GPP 3rd generation partnership project
  • the data of multicast services sent to multiple terminals share the same user plane function (UPF) and share the downlink tunnel between the UPF and the access network equipment.
  • the tunnel may be any downlink tunnel among the multiple downlink tunnels corresponding to the multiple terminals, and the downlink tunnel information used to identify the downlink tunnel is stored in the UPF.
  • the UPF can send the data of the multicast service to the access network device through the downlink tunnel according to the locally stored downlink tunnel information, and the access network device sends the data to multiple terminals. .
  • the terminal may be in a connected state or an idle state or an inactive state.
  • a terminal requiring multicast services is in an idle state or inactive state, the communication connection between the terminal and the access network device is disconnected, and the data of the multicast service sent by the access network device cannot be received, so it is impossible to guarantee All terminals in the multicast group receive the data of the multicast service.
  • Embodiments of the present application provide a data transmission method, device, and system to solve the problem that a terminal in an idle state or an inactive state cannot receive data of a multicast service.
  • a data transmission method includes: when there is at least one terminal in a preset state in a multicast group corresponding to a first multicast service, a session management network
  • the element sends the first information to the user plane network element for the user plane network element to send notification information to the session management network element when the data of the first multicast service arrives at the user plane network element, and the session management network element receives information from the user plane network element.
  • the notification information used to characterize the arrival of the data of the first multicast service to the user plane network element is sent to the mobility management network element according to the notification information to trigger the establishment of the communication connection between the first terminal and the first access network device.
  • the second information of the first terminal belongs to at least one terminal in a preset state;
  • the preset state includes an idle state, an inactive state, or there is no communication connection with the access network device for transmitting the data of the first multicast service.
  • the session management network element may send the first information to the user plane network element when there is at least one terminal in a preset state in the multicast group corresponding to the multicast service, indicating that the user
  • the plane network element sends notification information to the session management network element when the data of the first multicast service arrives at the user plane network element.
  • the trigger establishment is in a preset state
  • the communication connection between the terminal and the access network equipment so that after the communication connection is established, the data of the first multicast service is sent to the terminals in the multicast group through the communication connection between the access network equipment and the terminal, so as to avoid the
  • the terminal is in the preset state, the communication connection between the terminal and the access network equipment and the terminal for transmitting the data of the multicast service is disconnected, and the terminal cannot receive the data of the multicast service. All terminals can receive the data of the multicast service without loss.
  • the second information is further used to trigger the establishment of a communication connection between the second terminal and the second access network device. Based on this possible design, a piece of information can trigger the establishment of communication connections between multiple terminals and access network equipment, thereby reducing signaling overhead.
  • the first information includes first identification information for identifying data of the first multicast service.
  • the identification information used to indicate the data of the first multicast service is carried in the first information, and the user plane network element is explicitly instructed to send the data to the user plane network element when the data of the first multicast service reaches the user plane network element.
  • the session management network element sends the notification information, and the user plane network element does not need to indirectly determine the notification information to be sent to the session management network element according to the first information, which simplifies the system design.
  • the method further includes: when all the terminals in the multicast group corresponding to the first multicast service have communication connections with the access network equipment, the session management network element sends a message to the user plane network.
  • the element sends third information for informing the user plane network element to send the data of the first multicast service. In this way, it is ensured that all terminals in the multicast group receive the data of the multicast service without loss.
  • the method further includes: when all terminals in the at least one terminal in a preset state have communication connections with the access network equipment, the session management network element sends a message to the user plane network element.
  • the third information is used to notify the user plane network element to send the data of the first multicast service. In this way, it is at least ensured that the establishment of the communication connection between all the terminals in the preset state and the access network equipment is completed, and the data of the multicast service is received through the communication connection.
  • the method further includes: the session management network element sends a notification message to the user plane network element according to the first preset waiting time to notify the user plane network element.
  • the element sends the third information of the data of the first multicast service.
  • a waiting time can be pre-designed for the session management network element to send the third information to the user plane network element, and when the waiting time expires, the third information is sent to the user plane network element to simplify the system design.
  • the third information includes second identification information for identifying the data of the first multicast service.
  • the identification information used to identify the data of the first multicast service is carried in the third information to be explicitly indicated to the user plane network element, so that the user plane network element can directly know according to the identification information to send the first multicast service.
  • the user plane network element does not need to indirectly determine the data of the first multicast service to be sent, which simplifies the design complexity of the user plane network element.
  • the method further includes: the session management network element receives fourth information from the mobility management network element for deactivating the user plane transmission resources of the first terminal, and determines the first terminal according to the fourth information. in the default state. Based on this possible design, when the terminal is in a preset state, the information about deactivating the user plane transmission resource can be further sent to the session management network element, so that the session management network element can know that the terminal corresponding to the user plane transmission resource is in Preset states simplify system design.
  • the present application provides a communication device, which may be a session management network element on a session management network element or a chip or a system-on-chip in the session management network element.
  • the communication device can implement the functions performed by the communication device in the first aspect or a possible design of the first aspect, and the functions can be implemented by hardware or by executing corresponding software in hardware.
  • the hardware or software includes one or more modules corresponding to the above functions.
  • the communication device may include: a sending unit, a receiving unit;
  • the sending unit is configured to send, to the user plane network element, a message for the user plane network element in the first multicast service when there is at least one terminal in a preset state in the multicast group corresponding to the first multicast service. Send the first information of notification information to the session management network element when the data arrives at the user plane network element;
  • a receiving unit configured to receive notification information from the user plane network element that the data representing the first multicast service arrives at the user plane network element;
  • the sending unit is further configured to send, according to the notification information, to the mobility management network element second information for triggering the establishment of a communication connection between the first terminal and the first access network device, where the first terminal belongs to at least one preset state of the terminal.
  • the preset state includes an idle state, an inactive state, or there is no communication connection with the access network device for transmitting the data of the first multicast service.
  • each unit of the communication device reference may be made to the first aspect or the behavior function of the session management network element in the data transmission method provided by any possible design of the first aspect, which will not be repeated here.
  • the provided communication device can achieve the same beneficial effects as the first aspect or any possible design of the first aspect.
  • a communication device comprising: a processor and a memory; the memory is used to store computer-executed instructions, and when the communication device is running, the processor executes the computer-executed instructions stored in the memory, so that the The communication apparatus performs the data transmission method as described in the first aspect or any possible design of the first aspect.
  • a computer-readable storage medium is provided, and instructions are stored in the computer-readable storage medium, so that when the computer-readable storage medium runs on a computer, the computer can execute the first aspect or any of the above-mentioned aspects. Design the described data transfer method.
  • a computer program product containing instructions that, when run on a computer, enable the computer to execute the data transmission method described in the first aspect or any possible design of the above aspect.
  • a communication device may be a chip system, and the chip system may include a processor and a communication interface for supporting the communication device to implement the first aspect or any of the first aspects.
  • the processor sends a message for the user plane network element to the user plane network element through the communication interface.
  • the first information of notification information is sent to the session management network element, and the data used to characterize the first multicast service from the user plane network element arrives at the user plane network element.
  • the chip system further includes a memory for storing necessary program instructions and data of the communication device.
  • the chip system may be composed of chips, or may include chips and other discrete devices.
  • the embodiments of the present application provide yet another data transmission method, the method may include: a user plane network element receives data from a session management network element for the user plane network element in the first multicast service to arrive at the user plane network element Element time sends the first information of the notification information to the session management network element, and after receiving the data of the first multicast service, sends the data representing the first multicast service to the session management network element according to the first information and arrives at the user plane network element After receiving the notification message, the session management network element triggers the establishment of a communication connection between the terminal in the preset state and the access network device, and ensures that the terminal in the preset state receives the notification message through the communication connection without loss. Data of the first multicast service.
  • the user plane network element may, under the instruction of the session management network element, The user plane network element notifies the session management network element, so that the session management network element triggers the establishment of a communication connection between the terminal in the preset state and the access network device, so that after the communication connection is established, the connection between the access network device and the terminal is completed.
  • the method further includes: after the user plane network element receives the data of the first multicast service, buffering the data of the first multicast service, so that after the establishment of the subsequent communication connection is completed, the cached first multicast service is sent. Multicast service data.
  • the data of the first multicast service arrives at the user plane network element, the data is stored in a buffering manner, so as to prevent the terminal in the preset state from missing (or unable to receive) the first multicast service delivered within the time period data problem.
  • the first information includes first identification information for identifying the data of the first multicast service, that is, the explicit identification information instructs the user plane network element to monitor whether the data of the first multicast service arrives, And the session management network element is notified when the data of the first multicast service arrives, thereby simplifying the system design.
  • the method further includes: the user plane network element receives third information from the session management network element for notifying the user plane network element to send the data of the first multicast service, and sends the data according to the third information.
  • the data of the first multicast service that is, after the communication connection is established, the session management notifies the user plane network element to send the data of the first multicast service and then sends the data of the multicast service, so as to avoid the failure of sending the data of the multicast service.
  • the third information includes second identification information used to identify the data of the first multicast service, that is, the user plane network element is instructed to deliver the data of the first multicast service through the explicit identification information, which simplifies system design.
  • a communication device may be a user plane network element or a chip or a system-on-chip in the user plane network element.
  • the communication apparatus can implement the functions performed by the user plane network elements in the seventh aspect or the possible designs of the seventh aspect, and the functions can be implemented by hardware or by executing corresponding software in hardware.
  • the hardware or software includes one or more modules corresponding to the above functions.
  • the communication device may include: a receiving unit and a sending unit;
  • a receiving unit configured to receive the first information from the session management network element for the user plane network element to send notification information to the session management network element when the data of the first multicast service reaches the user plane network element; and receive the first multiple broadcast service data;
  • the sending unit is configured to send notification information to the session management network element according to the first information, where the notification information is used to indicate that the data of the first multicast service arrives at the user plane network element.
  • a communication device comprising: a processor and a memory; the memory is used to store computer-executed instructions, and when the communication device is running, the processor executes the computer-executed instructions stored in the memory, so that the The communication apparatus performs the data transmission method described in the seventh aspect or any possible design of the seventh aspect.
  • a computer-readable storage medium is provided, and instructions are stored in the computer-readable storage medium, so that when the computer-readable storage medium runs on a computer, the computer can execute the seventh aspect or any of the above-mentioned aspects. Design the described data transfer method.
  • a computer program product containing instructions, which, when run on a computer, enable the computer to execute the data transmission method described in the seventh aspect or any possible design of the above aspect.
  • a twelfth aspect provides a chip system
  • the chip system includes a processor and a communication interface, and is used to support a communication device to implement the functions involved in the above aspects.
  • the processor receives a function from a session management network element through the communication interface.
  • the user plane network element sends the first information of the notification information to the session management network element when the data of the first multicast service arrives at the user plane network element; and receives the data of the first multicast service, and sends the notification information to the session management network element according to the first information.
  • the network element sends notification information, where the notification information is used to indicate that the data of the first multicast service arrives at the user plane network element.
  • the chip system further includes a memory for storing necessary program instructions and data of the communication device.
  • the chip system may consist of chips, or include chips and other discrete devices.
  • a data transmission method comprising: the mobility management network element receiving a first information from the session management network element for triggering the establishment of a communication connection between the first terminal and the first access network device Second information, according to the second information, send fifth information for the first access network device to establish a communication connection with the first terminal to the first access network device.
  • the mobility management network element may send the second information to the first access network device under the trigger of the session management network element, so that the first access network device establishes its relationship with the first terminal
  • the communication connection between the first access network equipment realizes that the first access network device sends the data of the first multicast service to the first terminal through the communication connection, and ensures that the first terminal receives the data of the first multicast service without loss.
  • the mobility management network element receives the first indication information from the first access network device and is used to indicate that the establishment of the communication connection between the first terminal and the first access network device is completed.
  • the indication information sends second indication information to the session management network element for indicating that the establishment of the communication connection between the first terminal and the first access network device is completed, that is, the mobility management network element receives the communication connection sent by the access network device
  • the establishment completion information is to send indication information to the session management network element, so that the session management network element knows which terminals in the multicast group have completed the establishment of the communication connection, which simplifies the system design.
  • the second information is further used to trigger the establishment of a communication connection between the second terminal and the second access network device
  • the method further includes: The access network device sends sixth information for the second access network device to establish a communication connection with the second terminal, that is, the establishment of multiple communication connections is triggered by a piece of second information, thereby reducing signaling overhead.
  • the method further includes: the mobility management network element receiving a third message from the second access network device for indicating that the communication connection between the second terminal and the second access network device is established. Indication information, according to the third indication information, send the fourth indication information to the session management network element for indicating that the establishment of the communication connection between the second terminal and the second access network device is completed. Similarly, for other access network devices When the mobility management network element receives the communication connection establishment completion instruction sent by the access network device, it sends the instruction information to the session management network element, so that the session management network element can know which ones in the multicast group are sent. The establishment of the communication connection of the terminal is completed, which simplifies the system design.
  • the mobility management network element sends to the session management network element according to the second preset waiting period, a fifth indication for instructing the session management network element to trigger the establishment of the communication connection established by the mobility management network element is completed.
  • information That is, a preset waiting time is set for the mobility management network element.
  • the session management network element is notified that the establishment of the communication connection is completed, so as to ensure that as many communication connections as possible are established within the preset waiting time.
  • the access network device that first establishes and completes the communication connection triggers the data delivery of the multicast service, which affects other access networks with slower establishment of communication connections. The problem of packet loss in the terminal under the device.
  • the method when the first terminal is in an idle state, before the mobility management network element sends the fifth information to the first access network device, the method further includes: the mobility management network element sends the first access network element to the first access network device.
  • the network device sends a paging message for paging the first terminal, and the mobility management network element receives the service request message from the first terminal, that is, when the terminal is in the CM connection state, it sends a communication setup message to the access network device.
  • the fifth information of the connection ensures the accuracy of the establishment of the communication connection.
  • the session management network element can use a signaling message to indicate the terminal that joins the multicast group. To the mobility management network element, so that the mobility management network element paging the terminal in the idle state to receive the data of the first multicast service.
  • the mobility management network element receives the terminal equipment list UE list of the multicast group from the session management network element, the multicast group corresponds to the first multicast service, and the UE list indicates the terminals that join the multicast group; mobile The property management network element determines the terminal in the idle state among the terminals indicated by the UE list, and sends a paging message to the terminal in the idle state. That is, a single signaling message triggers paging of multiple terminals, thereby reducing signaling overhead.
  • the UE list is carried in the second information, and the second information may also include the identification information of the multicast group, so that the mobility management network element knows which multicast group the terminal initiates paging for, and sends the paging to the terminal.
  • the terminal in the idle state sends a paging message carrying the identification information of the multicast group, so that when the terminal in the idle state receives the paging message with the identification information of the multicast group, it can know whether it needs to initiate a service. Request (service request) process.
  • the terminals in the idle state include the first terminal and the second terminal
  • the mobility management network element sending a paging message to the terminals in the idle state includes: the The mobility management network element sends a paging message in the first paging area; wherein the paging message includes identification information of the multicast group, and the first paging area includes the registration area of the first terminal and the registration area of the second terminal.
  • the method further includes: the mobility management network element receives a service request message from the first terminal; and/or the mobility management network element receives a service request message from the second terminal.
  • the first paging area also includes registration areas of terminals other than the first terminal and the second terminal in the UE list.
  • the first paging area also includes the registration areas of the terminals in the idle state other than the first terminal and the second terminal in the UE list, so that group paging can be initiated in the registration areas of more terminals, which is convenient for more The terminal is called to receive the data of the first multicast service.
  • the present application provides a communication device, where the communication device may be a mobility management network element or a chip or a system-on-chip in the mobility management network element.
  • the communication apparatus may implement the functions performed by the mobility management network element in the thirteenth aspect or the possible designs of the thirteenth aspect, and the functions may be implemented by hardware or by executing corresponding software in hardware.
  • the hardware or software includes one or more modules corresponding to the above functions.
  • the communication device may include: a receiving unit, a sending unit, and a processing unit;
  • the receiving unit is configured to receive second information from the session management network element, where the second information is used to trigger the establishment of a communication connection between the first terminal and the first access network device, and the communication connection is used for transmitting the data of the first multicast service;
  • the sending unit is configured to send fifth information to the first access network device according to the second information, where the fifth information is used for the first access network device to establish a communication connection with the first terminal.
  • the receiving unit is configured to receive a UE list of user equipments from a multicast group of a session management network element, the multicast group corresponds to the first multicast service, and the UE list indicates A terminal that joins the multicast group.
  • a processing unit configured to determine a terminal in an idle state among the terminals indicated by the UE list;
  • a sending unit configured to send a paging message to the terminal in an idle state.
  • the communication device For the specific implementation of the communication device, reference may be made to the behavior function of the mobility management network element in the data transmission method provided by the thirteenth aspect or any possible design of the thirteenth aspect, the thirteenth aspect or the thirteenth aspect. Any of the possible design methods can be correspondingly implemented by the communication device including an acquiring unit and a sending unit.
  • a communication device comprising: a processor and a memory; the memory is used for storing computer-executed instructions, and when the communication device is running, the processor executes the computer-executed instructions stored in the memory, so that the communication
  • the apparatus performs the data transmission method as described in the thirteenth aspect or any possible design of the thirteenth aspect.
  • a sixteenth aspect provides a computer-readable storage medium, where instructions are stored in the computer-readable storage medium, when the computer-readable storage medium runs on a computer, the computer can execute the above-mentioned thirteenth aspect or any one of the above-mentioned aspects. possible design of the described data transfer method.
  • a seventeenth aspect provides a computer program product containing instructions that, when run on a computer, enable the computer to execute the data transmission method described in the thirteenth aspect or any possible design of the above aspect.
  • a chip system in an eighteenth aspect, includes a processor and a communication interface, and is used to support a communication device to implement the functions involved in the above aspects.
  • the processor receives a function from a session management network element through the communication interface. Based on the second information that triggers the establishment of the communication connection between the first terminal and the first access network device, according to the second information, send to the first access network device for the first access network device to establish a communication connection with the first terminal.
  • the chip system further includes a memory for storing necessary program instructions and data of the communication device.
  • the chip system may be composed of chips, or may include chips and other discrete devices.
  • a nineteenth aspect further provides a data transmission method, the method comprising: the first access network device receives data of the first multicast service, and when there is at least one multicast service in the multicast group corresponding to the first multicast service
  • the first access network device buffers the data of the first multicast service, and sends a paging message for paging the first terminal
  • the first terminal belongs to at least one A terminal that is served by the first access network device and is in a preset state, wherein the preset state includes an idle state, an inactive state, or there is no connection with the access network device for transmitting the first multicast service.
  • Data communication connection is
  • the terminal served by the first access network device when the terminal served by the first access network device is in a disconnected state, it first buffers the received data of the first multicast service, and initiates a call to the terminal, so that When the terminal is paged and switched to the connected state, the data of the multicast service is delivered, so as to ensure that the terminal receives the data of the multicast service without loss.
  • the method further includes: the first access network device receiving a first RRC message from the first terminal for requesting to establish a communication connection between the first terminal and the first access network device, According to the first RRC message, the fifth information for establishing the communication connection between the first terminal and the first access network device is obtained from the mobility management network element, and the first access network device sends the information to the first access network device according to the fifth information.
  • the terminal sends the seventh information used to indicate the relevant configuration of the communication connection between the first terminal and the first access network device, that is, when receiving the request for establishing the communication connection from the first terminal, obtain the seventh information.
  • Fifth information configure air interface resources for the terminal according to the fifth information, and indicate the configuration to the terminal, and simplify the system design when the communication connection is established.
  • the method further includes: when there is no terminal served by the first access network device and in a preset state in the multicast group corresponding to the first multicast service, the first access network device is in a preset state.
  • the network access device sends the cached data of the first multicast service, or the first access network device sends the cached data of the first multicast service according to the third preset waiting time, that is, the first access network device sends the cached data of the first multicast service.
  • the communication connections corresponding to all the terminals under the device service are completed, or the buffered multicast service data is sent when the preset waiting time expires, so as to ensure that as many terminals as possible receive the multicast service data.
  • the first RRC message is a service request message or an RRC recovery request message, that is, the above application scenario is performed when the first terminal is in an idle state or a disconnected state, and the application scenarios are flexible and diverse and have good adaptability.
  • the sending of the paging message by the first access network device to the first terminal includes: the first access network device sends the paging message to the first terminal through a first channel, and the first channel includes any one of the following: : the unicast channel, the public channel, and the dedicated channel of the multicast group corresponding to the first multicast service between the first access network device and the first terminal, that is, the paging message can be sent through any channel of multiple channels , flexible and diverse, good adaptability.
  • the present application provides a communication apparatus, where the communication apparatus may be a first access network device or a chip or a system-on-chip in the first access network device.
  • the communication apparatus can implement the functions performed by the first access network device in the nineteenth aspect or the possible designs of the nineteenth aspect, and the functions can be implemented by hardware or by executing corresponding software in hardware.
  • the hardware or software includes one or more modules corresponding to the above functions.
  • the communication device may include: a receiving unit, a processing unit, and a sending unit;
  • a receiving unit configured to receive data of the first multicast service
  • a processing unit configured to cache data of the first multicast service when there is at least one terminal served by the first access network device and in a preset state in the multicast group corresponding to the first multicast service;
  • the sending unit is configured to send a paging message for paging a first terminal, where the first terminal belongs to at least one terminal served by the first access network device and in a preset state.
  • the communication device For the specific implementation of the communication device, reference may be made to the behavior function of the first access network device in the data transmission method provided by the nineteenth aspect or any possible design of the nineteenth aspect, the nineteenth aspect or the tenth aspect. Any possible design method of the nine aspects may be correspondingly implemented by the communication device including the acquiring unit and the sending unit.
  • a twenty-first aspect provides a communication device, comprising: a processor and a memory; the memory is used to store computer-executed instructions, and when the communication device is running, the processor executes the computer-executed instructions stored in the memory, so that The communication device performs the data transmission method of the nineteenth aspect or any possible design of the nineteenth aspect.
  • a twenty-second aspect provides a computer-readable storage medium, where instructions are stored in the computer-readable storage medium, when the computer-readable storage medium runs on a computer, the computer can execute the nineteenth aspect or any one of the above aspects.
  • a twenty-third aspect provides a computer program product containing instructions that, when run on a computer, enable the computer to execute the data transmission method described in the nineteenth aspect or any possible design of the above aspects.
  • a twenty-fourth aspect provides a chip system
  • the chip system includes a processor and a communication interface, and is used to support the communication device to implement the functions involved in the above aspects, for example, the processor receives the first multicast service through the communication interface.
  • data when there is at least one terminal served by the first access network device and in a preset state in the multicast group corresponding to the first multicast service, cache the data of the first multicast service, and send the data for the first multicast service.
  • a paging message for paging the first terminal where the first terminal belongs to at least one terminal served by the first access network device and in a preset state.
  • the chip system further includes a memory for storing necessary program instructions and data of the communication device.
  • the chip system may be composed of chips, or may include chips and other discrete devices.
  • a twenty-fifth aspect of the embodiments of the present application provides a data transmission method, the method comprising: a session management network element receiving fourth information from a mobility management network element for deactivating a user plane transmission resource of a first terminal , according to the fourth information, send the second information for establishing the communication connection between the first terminal and the first access network device to the mobility management network element, that is, when the user plane resources of the first terminal are deactivated , send the second information for establishing a communication connection to the mobility management network element, so that the mobility management network element configures air interface resources for the terminal according to the second information, and ensures that the terminal receives multicast services without loss based on the air interface resources configured for it.
  • the data comprising: a session management network element receiving fourth information from a mobility management network element for deactivating a user plane transmission resource of a first terminal , according to the fourth information, send the second information for establishing the communication connection between the first terminal and the first access network device to the mobility management network element, that is, when the user plane
  • the session management network element sending the second information to the mobility management network element includes: the session management network element sends a subscription request to the mobility management network element for requesting to subscribe to the first event, where the first event is the first event.
  • a terminal transitions from a preset state to a connected state; the session management network element receives event notification information from the mobility management network element, and the event notification information is used to notify the first event; the session management network element sends a notification to the mobility management network element according to the event notification information
  • the element sends the second information, that is, sends the second information through the subscription process, which simplifies the system design.
  • the present application provides a communication device, where the communication device may be a session management network element on a session management network element or a chip or a system-on-chip in the session management network element.
  • the communication device can implement the functions performed by the communication device in the twenty-fifth aspect or possible designs of the twenty-fifth aspect, and the functions can be implemented by hardware or by executing corresponding software in hardware.
  • the hardware or software includes one or more modules corresponding to the above functions.
  • the communication device may include: a receiving unit, a sending unit;
  • a receiving unit configured to receive fourth information from the mobility management network element for deactivating the user plane transmission resources of the first terminal
  • the sending unit is configured to send, according to the fourth information, second information for establishing a communication connection between the first terminal and the first access network device to the mobility management network element.
  • each unit of the communication device reference may be made to the behavior function of the session management network element in the data transmission method provided by the twenty-fifth aspect or any possible design of the twenty-fifth aspect, which is not repeated here. Repeat.
  • the provided communication device can achieve the same beneficial effects as the twenty-fifth aspect or any possible design of the twenty-fifth aspect.
  • a twenty-seventh aspect provides a communication device, comprising: a processor and a memory; the memory is used to store computer-executed instructions, and when the communication device operates, the processor executes the computer-executed instructions stored in the memory to The communication device is caused to perform the data transmission method described in the above twenty-fifth aspect or any possible design of the twenty-fifth aspect.
  • a twenty-eighth aspect provides a computer-readable storage medium, where instructions are stored in the computer-readable storage medium, when the computer-readable storage medium runs on a computer, the computer can execute the twenty-fifth aspect or any of the above aspects.
  • a twenty-ninth aspect provides a computer program product comprising instructions that, when run on a computer, enable the computer to perform the data transmission described in the twenty-fifth aspect above or any possible design of the above aspect method.
  • a thirtieth aspect provides a communication device, the communication device may be a chip system, and the chip system may include a processor and a communication interface for supporting the communication device to implement the above twenty-fifth aspect or the twenty-fifth aspect
  • the processor receives the fourth information from the mobility management network element through the communication interface for deactivating the user plane transmission resources of the first terminal, and according to the fourth information, the mobile The property management network element sends second information for establishing a communication connection between the first terminal and the first access network device.
  • the chip system further includes a memory for storing necessary program instructions and data of the communication device.
  • the chip system may be composed of chips, or may include chips and other discrete devices.
  • a thirty-first aspect provides a communication system, which may include the communication device or chip system according to any one of the second to sixth aspects, and the communication device or chip system according to any one of the eighth to twelfth aspects.
  • the communication system may include the communication device or chip system according to any one of the twentieth to twenty-fourth aspects, and the communication device or chip system according to any one of the twenty-sixth to thirtieth aspects .
  • Figure 1a is a schematic diagram of a "pseudo-broadcast" mode
  • Figure 1b is a schematic diagram of another "pseudo-broadcast" mode
  • Figure 1c is a schematic diagram of yet another "pseudo-broadcast" mode
  • FIG. 2 is a schematic diagram of an access network release process
  • 3a is a schematic diagram of the architecture of a communication system
  • FIG. 3b is a schematic diagram of the architecture of a 5G communication system
  • FIG. 4 is a schematic diagram of the composition of a communication apparatus 400 according to an embodiment of the present application.
  • FIG. 5 is a flowchart of a data transmission method provided by an embodiment of the present application.
  • FIG. 6 is a flowchart of a data transmission method provided by an embodiment of the present application.
  • FIG. 8a is a flowchart of another data transmission method provided by an embodiment of the present application.
  • FIG. 8b is a flowchart of another data transmission method provided by an embodiment of the present application.
  • FIG. 9 is a schematic diagram of the composition of a communication device 90 according to an embodiment of the present application.
  • FIG. 10 is a schematic diagram of the composition of a communication device 100 according to an embodiment of the present application.
  • FIG. 11 is a schematic diagram of the composition of a communication device 110 according to an embodiment of the present application.
  • FIG. 12 is a schematic diagram of the composition of a communication apparatus 120 according to an embodiment of the present application.
  • FIG. 13 is a schematic diagram of the composition of a communication system according to an embodiment of the present application.
  • a “pseudo-broadcast” method is adopted.
  • the "pseudo-broadcast” mode may refer to the combination of multicast service data sent to multiple terminals at the UPF and/or access network equipment.
  • FIG. 1a is a schematic diagram of combining data of multicast services sent to multiple terminals in UPF and access network equipment.
  • UPF combines the received data of multicast services sent to multiple terminals. After the data of the multicast service is generated, it is sent to the access network device through a communication connection. After the access network device receives the data of the multicast service, it uses the radio network temporary identifier (RNTI) to identify the data. The data of the multicast service is encoded and then broadcast to multiple terminals. There is no need for the UPF to send the data of the multiple multicast services to the access network equipment through multiple communication connections, and the access network equipment will broadcast the multiple multicast services. Service data is sent to multiple terminals through multiple communication connections to improve resource utilization.
  • RNTI radio network temporary identifier
  • FIG. 1b is a schematic diagram of data of multicast services sent to multiple terminals being merged in an access network device.
  • the UPF sends data of multiple multicast services sent to multiple terminals to the access network.
  • the network access device after accessing the data of the multiple multicast services received by the network device, merges the data of the multiple multicast services into one multicast service data, and uses the group RNTI to combine the data of the multicast service. After encoding processing, it is broadcast to multiple terminals, without the need for access network equipment to send data of multiple multicast services to multiple terminals through multiple communication connections, thereby improving resource utilization.
  • the communication connection between the UPF and the access network device for transmitting the data of the multicast service may be the unicast protocol data unit (protocol data unit, PDU) the communication connection corresponding to the session.
  • PDU protocol data unit
  • FIG. 1c there are three terminals in the multicast group: terminal 1, terminal 2 and terminal 3. Each terminal has established a PDU session, and the PDU sessions of all terminals correspond to the same UPF.
  • a PDU session can be selected from the PDU sessions of the three terminals in advance.
  • the data of the multicast service is mapped to the quality of service flow (QoS flow, QF) corresponding to the PDU session of the terminal 2, and the downlink tunnel information of the access network device corresponding to the PDU session is determined, according to the access network device.
  • QoS flow, QF quality of service flow
  • the communication connection described in the embodiments of the present application may also be described as a downlink transmission tunnel instead.
  • the terminal's PDU session may be described instead as the terminal's unicast PDU session.
  • the downlink tunnel information of the access network device may be used to establish a communication connection between the UPF and the access network device, and the downlink tunnel information of the access network device may include the Internet Protocol (IP) address of the access network device and/or the tunnel endpoint identifier (TEID) of the access network device.
  • IP Internet Protocol
  • TEID tunnel endpoint identifier
  • the session management network element may store the downlink tunnel information of the access network device corresponding to the PDU session of the terminal and the quality of service flow (QoS flow identifier, QFI) of the PDU session in the UPF, so that According to the corresponding relationship between the downlink tunnel information of the access network device and the QFI, the UPF sends the data of the multicast service mapped to the QF to the access network device indicated by the downlink tunnel information.
  • QFI quality of service flow
  • the terminal corresponding to the selected PDU session such as terminal 2
  • a preset state eg, idle state or inactive state
  • the selected PDU session is released, and the UPF and the access network equipment
  • the communication connection may be disconnected between them, and the downlink tunnel information of the access network device is deleted from the local storage of the UPF.
  • the UPF can trigger the access when it finds that the downlink tunnel information of the access network device corresponding to the QF corresponding to the data of the multicast service does not exist locally.
  • the network device or the core network device initiates paging for the terminal.
  • the access network device After the paging is successful, configure the downlink tunnel information of the access network device on the UPF, so that the UPF can re-multicast the data of the multicast service according to the downlink tunnel information of the access network device.
  • the access network device is sent to multiple terminals by the access network device.
  • this method can only enable the successfully paging terminal and other terminals in the radio resource control (RRC) connection state among multiple terminals to receive the data of the multicast service, and the data requirements for the multicast service are
  • the terminal in the preset state cannot receive the data of the multicast service due to the disconnection of the communication connection with the access network equipment, and cannot meet the demand of all terminals to receive the data of the multicast service in the "pseudo-broadcast" mode.
  • terminal 1 is in RRC connection state
  • the selected PDU session of terminal 2 transmits data of multicast services
  • the access network equipment corresponding to the PDU session of terminal 2 The downlink tunnel information is removed from the UPF.
  • the UPF still needs to transmit the data of the multicast service through the PDU session of the terminal 2
  • the UPF pages the terminal 2.
  • the downlink tunnel information of the access network device corresponding to the PDU session of the terminal 2 is obtained. It is reconfigured on the UPF.
  • the UPF sends the multicast service data to the access network device according to the downlink tunnel information of the access network device, and the access network device sends it to the terminal 1 and terminal 2, and the terminal 3 is in an idle state. , the communication connection between the terminal 3 and the access network device is disconnected, so that the terminal 3 cannot receive the data of the multicast service.
  • the session management network element when there is at least one terminal in a preset state (such as an idle state or an inactive state) in the multicast group, the session management network element instructs the user plane network element in the first
  • the data of a multicast service reaches the user plane network element, it sends notification information to the session management network element, and when the session management network element receives the notification information, it triggers paging of the terminal in the preset state, so that when the terminal in the preset state is Or after there is no terminal in a preset state among all the terminals in the multicast group, the user plane network element is instructed to send the data of the first multicast service.
  • the first access network device when the terminal corresponding to the first access network device included in the multicast group is in a preset state, after receiving the data of the first multicast service, the first access network device first buffers the first multicast service At the same time, the terminal in the preset state is paged by the first access network device, triggering the terminal to establish a communication connection with the first access network device, and when there is no arbitrary terminal in the multicast group After a terminal is in a preset state, the buffered data of the first multicast service is delivered. In this way, it is ensured that the terminals in the multicast group all receive the data of the first multicast service.
  • the preset state described in this application may include an idle state, an inactive state, or any state in which there is no communication connection with the access network device for transmitting the data of the first multicast service , it may also include that there is no communication connection between the access network device and the user plane network element for transmitting the data of the first multicast service. There is no communication connection between the access network devices for transmitting the data of the multicast service.
  • the multicast session context information corresponding to the first multicast service is released/deleted/removed on the access network device side.
  • the network access device and the user plane network element for transmitting the data of the first multicast service.
  • the user plane network element releases the transmission tunnel corresponding to the multicast session, such as deleting the locally stored access network device. tunnel information, delete/remove/release the locally stored N4 context corresponding to the first multicast service, etc.
  • the connected state described in this application can be replaced by a non-idle state, and for core network devices (such as mobility management network elements, session management network elements), the connected state may include radio resource control (radio resource control, RRC) connected (RRC_connected) state and connection management (connection management, CM) connected (CM_connected) state, or the connected state may include an inactive state and a CM connected state.
  • RRC radio resource control
  • CM connection management
  • the connected state may include an inactive state and a CM connected state.
  • the connected state may include the RRC connected state.
  • the RRC connected state may refer to the existence of an RRC connection between the terminal and the access network equipment
  • the CM connected state may refer to the existence of a non-access stratum (NAS) between the terminal and the core network equipment (such as mobility management network elements).
  • NAS non-access stratum
  • Signaling connection there is an N2 connection between the access network equipment and the core network equipment.
  • both the access network device and the core network device save the context of the terminal.
  • the access network device knows that the terminal is within the coverage of the access network device or within the management range of the access network device.
  • the core network device knows through which access network device the terminal can be located or found.
  • the terminal can perform downlink data and/or uplink data transmission with the access network device.
  • the idle state may mean that there is no RRC connection between the terminal and the access network device.
  • the idle state may be referred to as the RRC_idle state.
  • the context of the terminal is not stored in the access network equipment, there is no NAS signaling connection between the terminal and core network equipment (such as mobility management network elements), and the access network equipment and core network equipment (such as mobility management network elements) There is no N2 connection between network elements), and the core network device saves the context of the terminal.
  • the access network device does not know whether the terminal is within the coverage of the access network device.
  • the core network device does not know which access network device the terminal is covered by or within the management range, and the access network device does not know through which access network device the terminal can be located or found.
  • the inactive state can be called RRC_inactive state.
  • the inactive state can mean that there is no RRC connection between the terminal and the access network equipment.
  • In the inactive state there is no connection between the terminal and the core network equipment (such as mobility management network elements).
  • the context of the terminal is stored in the access network device, and the context of the terminal may be stored in the core network device.
  • the access network device does not know the specific cell in which the terminal resides within the coverage of the access network device or whether it is within the management scope of the access network device.
  • the core network device knows which access network device the terminal is covered by.
  • the core network device knows through which access network device it can locate or find the terminal.
  • the above three states of RRC_connected, RRC_idle, and RRC_inactive can be converted to each other.
  • the terminal After the terminal selects the cell to be accessed, but before accessing the access network device corresponding to the cell, the terminal can successfully establish an RRC connection with the access network device through the RRC establishment process, access the cell, and enter the RRC_connected state. Trigger the establishment of a CM connection between the access network device and the mobility management network element.
  • the access network device can make the state of the terminal change from the RRC_connected state to the RRC_idle state or the RRC_inactive state through the RRC release process.
  • the access network device does not receive the uplink or downlink data of the terminal within a certain period of time.
  • the access network device will determine to release the context of the terminal, and the access network device will send the The mobility management network element sends a user equipment (user equipment, UE) context release request that requests to release the context of the terminal, the mobility management network element receives the UE context release request, and sends a UE context release command to the access network device, and the access network device Receive the UE context release command, and send an RRC release (RRC release) message to the terminal to request the terminal to release the RRC connection.
  • UE user equipment
  • the terminal After the terminal receives the RRC release message, it disconnects the RRC connection with the access network device, and switches from the RRC_connected state or The RRC_inactive state enters the RRC_idle state, the access network device sends a UE context release complete message to the mobility management network element, and the mobility management network element receives the UE context release complete message, further optionally, if the terminal currently has an active user plane context , the mobility management network element will notify the corresponding session management network element to deactivate the user plane transmission resources. After the above process is completed, the mobility management network element will consider that the terminal is in the CM idle state.
  • the terminal in order to improve the resource utilization rate, when the terminal establishes a PDU session, it also includes a process of deactivating/releasing transmission resources on the user plane of the terminal, such as: the access network equipment to the mobility management network
  • the UE context release complete message sent by the device carries the ID of the PDU session of the terminal.
  • the mobility management network element After receiving the UE context release complete message sent by the access network device, the mobility management network element sends the PDU session to the session management network element that manages the PDU session. Deactivation instruction.
  • the session management network element After receiving the PDU session deactivation instruction, the session management network element notifies the user plane network element to delete the corresponding relationship between the terminal data and QF and the corresponding relationship between QF and downlink tunnel information, and release the user plane transmission resource.
  • the session management network element After receiving the PDU session deactivation instruction, the session management network element notifies the user plane network element to delete the corresponding relationship between the terminal data and QF and the corresponding relationship between QF and downlink tunnel information, and release the user plane transmission resource.
  • the process shown in FIG. 2 reference may be made to the prior art, which will not be repeated.
  • the terminal can change the state of the terminal from the RRC_idle state to the RRC_connected state through the RRC establishment process.
  • the access network device can send a paging message to the terminal, and the terminal receives the paging message and determines that it is connected to the terminal.
  • the terminal is triggered to initiate an RRC establishment process, trying to establish an RRC connection with the access network device to enter the RRC_connected state. If the RRC connection is successfully established, the terminal enters the RRC_connected state, and if the RRC connection establishment fails, the terminal continues to stay in the RRC_idle state.
  • the terminal can receive a paging message from the access network device, and after confirming that it has been paged, try to restore the RRC connection with the access network device through the RRC resume (resume) process to enter the RRC_connected state, such as the terminal Send an RRC resume request (resume resquest) message to the access network device.
  • the access network device After receiving the RRC resume request message, the access network device sends an RRC setup message or an RRC resume (resume) message to the terminal, so that the state of the terminal can be converted to the RRC_connected state .
  • the access network device can change the state of the terminal from the RRC_inactive state to the RRC_idle state through the RRC release process.
  • the access network device sends an RRC release message to the terminal to make the state of the terminal change from the RRC_inactive state to the RRC_idle state; Or, the access network device sends an RRC rejection message to the terminal, so that the terminal continues to stay in the RRC_inactive state.
  • the context of the terminal stored on the access network device is different from the context of the terminal stored on the core network device.
  • the context of the terminal stored by the access network device is related to the data transmission of the terminal.
  • the context of the terminal may include the identification information of the terminal, the quality of service policy (QoS profile), and the context of the terminal saved on the core network device is the context related to the movement and registration of the terminal.
  • the context of the terminal saved by the core network device may include the Identification information, location information of the terminal, registration area of the terminal, current CM connection status of the terminal, and so on.
  • the identification information of the terminal may be used to identify the terminal.
  • the identification information of the terminal may be an internet protocol (IP) address of the terminal, a media access control (media access control, MAC) address of the terminal, an international mobile subscriber identity (IMSI) of the terminal, Any identification information in the identification of the PDU session, the identification of the terminal can also be other information that can identify the terminal appearing in future communication standards, such as session management context identification (SM context ID), etc., without limitation.
  • IP internet protocol
  • MAC media access control
  • IMSI international mobile subscriber identity
  • Any identification information in the identification of the PDU session, the identification of the terminal can also be other information that can identify the terminal appearing in future communication standards, such as session management context identification (SM context ID), etc., without limitation.
  • SM context ID session management context identification
  • the communication system may include multiple terminals, mobility management network elements, session management network elements, and access network equipment , User plane network element. Further, the communication system shown in FIG. 3a may further include a data network (DN), and the DN may include an application server (AS).
  • DN data network
  • AS application server
  • the terminal may be a device for implementing a wireless communication function, such as a terminal or a chip that can be used in the terminal.
  • the terminal may be a UE, an access terminal, a terminal unit, a terminal station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a wireless communication device, a terminal agent or a terminal in a 5G network or a future evolved communication system device etc.
  • the access terminal may be a cellular telephone, a cordless telephone, a session initiation protocol (SIP) telephone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a wireless communication Functional handheld devices, computing devices or other processing devices connected to wireless modems, in-vehicle devices or wearable devices, virtual reality (VR) end devices, augmented reality (AR) end devices, industrial control (industrial) wireless terminal in control), wireless terminal in self-driving, wireless terminal in remote medical, wireless terminal in smart grid, wireless terminal in transportation safety Terminals, wireless terminals in smart cities, wireless terminals in smart homes, etc. Terminals can be mobile or stationary.
  • SIP session initiation protocol
  • WLL wireless local loop
  • PDA personal digital assistant
  • a wireless communication Functional handheld devices computing devices or other processing devices connected to wireless modems, in-vehicle devices or wearable devices, virtual reality (VR) end devices, augmented reality (AR) end devices, industrial control (industrial) wireless terminal in control), wireless terminal in self-driving,
  • Access network equipment is mainly used to implement functions such as physical layer functions, resource scheduling and management, terminal access control, and mobility management.
  • the access network device may be a device supporting wired access or a device supporting wireless access.
  • the access network device may be an access network (access network, AN)/radio access network (radio access network, RAN), which is composed of multiple 5G-AN/5G-RAN nodes.
  • 5G-AN/5G-RAN nodes can be: access point (AP), base station (nodeB, NB), enhanced base station (enhance nodeB, eNB), next-generation base station (NR nodeB, gNB), transmission and reception A transmission reception point (TRP), a transmission point (TP), or some other access node, etc.
  • Mobility management network element mainly responsible for terminal access authentication, mobility management, signaling interaction between various functional network elements, such as: user registration status, user connection status, user registration and access to the network, tracking area Update, cell handover user authentication and key security are managed.
  • the session management network element is mainly used to implement user plane transmission logical channels, such as session management functions such as establishment, release and modification of PDU sessions.
  • the user plane network element can be used as the anchor point on the user plane transmission logical channel to complete functions such as routing and forwarding of user plane data, such as: establishing a channel with the terminal (that is, the user plane transmission logical channel), on the channel It forwards data packets between the terminal and the DN, and is responsible for data packet filtering, data forwarding, rate control, and generation of charging information for the terminal.
  • an operator network that can provide users with data transmission services, such as an operator network that can provide users with Internet Protocol (Internet Protocol, IP) multimedia services (IP multi-media service, IMS).
  • IP Internet Protocol
  • IMS IP multi-media service
  • Fig. 3a is only an exemplary architecture diagram, in addition to the functional units shown in Fig. 3a, the system may also include other functional network elements, such as: operation and management (operation and management, O&M) network elements, etc., This embodiment of the present application does not limit this.
  • O&M operation and management
  • the names of each device in FIG. 3a are not limited.
  • each device can also be named with other names, such as the name of a network element with the same or similar functions, which is not limited.
  • the system shown in FIG. 3a may be a 3rd generation partnership project (3GPP) communication system, such as a 4th generation (4G) communication system, a long term evolution (long term evolution, LTE) system, It can also be a fifth-generation (5th generation, 5G) communication system, a new radio (NR) system, a next-generation communication system, etc., or a non-3GPP communication system, which is not limited.
  • 3GPP 3rd generation partnership project
  • 4G 4th generation
  • LTE long term evolution
  • 5G fifth-generation
  • NR new radio
  • next-generation communication system etc.
  • non-3GPP communication system which is not limited.
  • the network element or entity corresponding to the above session management network element may be a session management function (session management function) in the 5G communication system.
  • management function, SMF the network element or entity corresponding to the above-mentioned user plane network element may be a user plane function (UPF) in the 5G communication system
  • the network element or entity corresponding to the access network equipment may be 5G communication
  • the radio access network (RAN) and the network element or entity corresponding to the mobility management network element in the system may be the access and mobility management function (AMF) in the 5G communication system.
  • the session management network element and the mobility management network element in the embodiment of the present application may also be referred to as a communication device, which may be a general-purpose device or a dedicated device, which is not specifically limited in the embodiment of the present application.
  • the related functions of the session management network element, the user plane network element, and the access network device in the embodiment of the present application may be implemented by one device, or may be implemented jointly by multiple devices, or may be implemented by a device within one device.
  • One or more functional modules are implemented, which is not specifically limited in this embodiment of the present application. It is to be understood that the above-mentioned functions may be either network elements in hardware devices, or software functions running on dedicated hardware, or a combination of hardware and software, or virtualization instantiated on a platform (eg, a cloud platform) Features.
  • FIG. 4 is a schematic diagram of the composition of a communication apparatus 400 according to an embodiment of the present application.
  • the communication apparatus 400 may include a processor 401 and a memory 404 .
  • the communication device 400 may further include a communication line 402 and a communication interface 403 .
  • the processor 401 , the memory 404 and the communication interface 403 may be connected through a communication line 402 .
  • the processor 401 can be a central processing unit (central processing unit, CPU), a general-purpose processor, a network processor (network processor, NP), a digital signal processor (digital signal processing, DSP), a microprocessor, a microcontroller , programmable logic device (PLD) or any combination of them.
  • the processor 401 may also be other apparatuses with processing functions, such as circuits, devices or software modules, which are not limited.
  • the communication line 402 is used to transmit information between various components included in the communication device 400 .
  • the communication interface 403 is used to communicate with other devices or other communication networks.
  • the other communication network may be Ethernet, radio access network (RAN), wireless local area networks (WLAN) and the like.
  • Communication interface 403 may be a module, circuit, transceiver, or any device capable of enabling communication.
  • Memory 404 for storing instructions.
  • the instructions may be computer programs.
  • the memory 404 may be a read-only memory (ROM) or other types of static storage devices that can store static information and/or instructions, or a random access memory (RAM) or a random access memory (RAM).
  • ROM read-only memory
  • RAM random access memory
  • RAM random access memory
  • RAM random access memory
  • RAM random access memory
  • EEPROM electrically erasable programmable read-only memory
  • CD- ROM compact disc read-only memory
  • optical disc storage including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs
  • magnetic disk storage media and other magnetic storage devices, without limitation.
  • the memory 404 may exist independently of the processor 401 , or may be integrated with the processor 401 .
  • the memory 404 may be used to store instructions or program code or some data or the like.
  • the memory 404 may be located in the communication device 400, or may be located outside the communication device 400, which is not limited.
  • the processor 401 is configured to execute the instructions stored in the memory 404 to implement the data transmission methods provided by the following embodiments of the present application. For example, when the communication device 400 is a session management network element or a chip or a system-on-chip in the session management network element, the processor 401 executes the instructions stored in the memory 404, so as to realize the execution of the session management network element in the following embodiments of the present application. A step of. For another example, when the communication device 400 is a mobility management network element or a chip or a system-on-chip in the mobility management network element, the processor 401 may execute the instructions stored in the memory 404 to implement the mobility management in the following embodiments of the present application The steps performed by the network element.
  • processor 401 may include one or more CPUs, such as CPU0 and CPU1 in FIG. 4 .
  • the communication apparatus 400 includes a plurality of processors, for example, in addition to the processor 401 in FIG. 4 , a processor 407 may also be included.
  • the communication apparatus 400 further includes an output device 405 and an input device 406 .
  • the input device 406 is a device such as a keyboard, a mouse, a microphone or a joystick
  • the output device 405 is a device such as a display screen, a speaker, and the like.
  • the communication apparatus 400 may be a desktop computer, a portable computer, a network server, a mobile phone, a tablet computer, a wireless terminal, an embedded device, a chip system, or a device with a similar structure in FIG. 4 .
  • the composition shown in FIG. 4 does not constitute a limitation on the communication device.
  • the communication device may include more or less components than those shown in the figure, or combine some components , or a different component arrangement.
  • the chip system may be composed of chips, or may include chips and other discrete devices.
  • actions, terms, etc. involved in the various embodiments of the present application can be referred to each other, and are not limited.
  • the names of the messages or the names of parameters in the messages exchanged between the devices are just an example, and other names may also be used in the specific implementation, which is not limited.
  • the data transmission method provided by the embodiment of the present application is described below by taking the architecture shown in FIG. 3a as an example.
  • Each network element in the following embodiments may have the components shown in FIG. 4 , which will not be repeated.
  • the name of the message or the name of the parameter in the message interacted with each other is just an example, and other names may also be used in the specific implementation.
  • the multicast described in the embodiments of the present application may be replaced by terms such as broadcast (broadcast), multicast (multicast), and multicast/broadcast.
  • the determination in the embodiments of the present application may also be understood as creating (create) or generating (generating), and “include” in the embodiments of the present application may also be understood as “carrying”, etc., which are not specifically limited in the embodiments of the present application.
  • FIG. 5 is a data transmission method provided by an embodiment of the present application. As shown in FIG. 5 , the method may include:
  • Step 501 In the case where there is at least one terminal in a preset state in the multicast group corresponding to the first multicast service, the session management network element sends the first information to the user plane network element.
  • the session management network element may be a session management network element that manages a multicast session corresponding to the first multicast service, such as a multicast session management network element, and the session management network element may also be a PDU session management terminal (such as a single Session management network elements such as unicast session management network elements.
  • the user plane network element may be the anchor point of the first multicast service, and the user plane network element may not be the anchor point of the first multicast service.
  • the user plane network element may be used to connect the access network equipment and the first multicast service.
  • the user plane network element between the anchor points, such as the user plane network element corresponding to the PDU session is the anchor point of the unicast service.
  • a communication connection is established between the user plane network element and the access network equipment.
  • the user plane network element A communication connection is established between the element and the anchor of the first multicast service.
  • the first multicast service may refer to a service oriented to multiple terminals.
  • the first multicast service may be a TV program, a file transmission service, intra-group voice or video communication, and a broadcast service within a fleet.
  • Multiple terminals targeted by the first multicast service may join a group, which may be called a multicast group corresponding to the first multicast service, and all terminals in the multicast group may or may not be authorized
  • the data of this multicast service can be received.
  • the multicast group corresponding to the first multicast service may be a combination of multiple terminals that receive data of the first multicast service.
  • the multicast group may be a fleet that receives commands from the same command center or a group that receives the same TV. Program user groups, etc.
  • multiple terminals may join the multicast group by referring to the method shown in FIG. 1a or FIG. 1b, and multiple terminals share the same user plane network element.
  • the session management network element can select a PDU session from the PDU sessions established by multiple terminals or establish a dedicated channel for a multicast group, and map the data of the first multicast service to the selected PDU session or multicast.
  • the QF corresponding to the dedicated channel of the group, and locally stores the context information of the multicast group.
  • the context information of the multicast group may include the identification information of multiple terminals that join the multicast group, and the identification information of the user plane network elements.
  • the mapping relationship between the QF and the first multicast service is correspondingly configured to the user plane network element, so that after the user plane network element receives the data of the first multicast service, The data of the first multicast service is sent to multiple terminals through the QF.
  • the detailed process of establishing a PDU session and joining a multicast group by the terminal may refer to the prior art, and will not be repeated.
  • the session management network element may determine that there is at least one terminal in a preset state in the multicast group corresponding to the first multicast service by using the following example 1 or example 2.
  • the first terminal is in the preset state as an example to describe the two modes of Example 1 and Example 2:
  • Example 1 The mobility management network element determines that the RRC connection between the first terminal and the access network device is disconnected and cannot transmit data to the first terminal.
  • the mobility management network element sends a message for deactivating the first terminal to the session management network element.
  • the fourth information of the user plane transmission resource may carry the identification information of the PDU session of the first terminal, for example, may carry the ID of the PDU session of the first terminal.
  • the session management network element receives the fourth information, and determines according to the fourth information that the first terminal served by the mobility management network element is in a preset state.
  • the fourth information may be named as deactivation indication or other names, which are not limited.
  • the mobility management network element may carry the fourth information in an Nsmf_PDU session update session management context request (Nsmf_PDU session_update SMContext request) and send it to the session management network element.
  • sending the fourth information by the mobility management network element to the session management network element may include: the mobility management network element sends a message to the first network element for indicating the first Information of a multicast group corresponding to a multicast service (such as identification information of the multicast group) and fourth information, the first network element receives the information used to indicate the multicast group corresponding to the first multicast service and the fourth information. Fourth information, sending a subscription message carrying the fourth information to the session management network element that manages the multicast session corresponding to the multicast group.
  • the first network element is a unicast session management network element corresponding to the first terminal or another intermediate network element for forwarding the fourth information, which is not limited.
  • the terminal in the preset state may be recorded in the context of the multicast group corresponding to the first multicast service by taking the terminal as the granularity, such as: session
  • the management network element may set a flag corresponding to the identification information of the terminal in the context of the multicast group corresponding to the first multicast service, where the identification information is used to identify that the terminal identified by the identification information of the terminal is in a preset state.
  • Example 2 The mobility management network element determines that the RRC connection between the first terminal served by the mobility management network element and the access network device is disconnected, and data cannot be transmitted to the first terminal, and sends a message to the session management network element to indicate the first terminal.
  • the multicast group corresponding to the multicast service there is at least one event opening notification message (Namf_EventExposure Notify) of the terminal that is served by the mobility management network element and is in a preset state, and the session management network element receives the event opening notification message according to the The event opening notification message determines that there is at least one terminal in a preset state in the multicast group corresponding to the first multicast service.
  • Event_EventExposure Notify an event opening notification message
  • the mobility management network element sending the event open notification message to the session management network element may include: the mobility management network element sends to the first network element a message indicating The information of the multicast group corresponding to the first multicast service (such as the identification information of the multicast group) and the event opening notification message, and the first network element receives the information used to indicate the multicast group corresponding to the first multicast service and an event opening notification message, which sends the event opening notification message to the session management network element that manages the multicast session corresponding to the multicast group.
  • the first network element is a unicast session management network element corresponding to the first terminal or another intermediate network element for forwarding the event opening notification message, which is not limited.
  • the first network element may send other types of messages, such as request messages or subscription messages, to the session management network element. etc., the content indicated by other types of messages is the same as the content indicated by the event opening notification message or the fourth information, which is not limited in this embodiment of the present application.
  • the session management network element may record the multicast group as granularity. There is at least one terminal in a preset state in the multicast group. For example, the session management network element sets a flag information corresponding to the context of the multicast group corresponding to the first multicast service, and the flag information is used to identify the multicast group.
  • a group includes terminals in a preset state. In this case, the session management network element does not need to know the specific terminal in the preset state.
  • the session management network element may locally store the corresponding relationship between the identification information of the mobility management network element and the identification information of the first multicast service, so as to indicate that the multicast group corresponding to the first multicast service is in a preset state. Stateful terminals are served by this mobility management network element. If the session management network element receives the event notification message through the first network element, the session management network element may also store the identification information of the first network element and the identification information of the first multicast service locally, and the first network element may store the mobile The correspondence between the identification information of the property management network element and the identification information of the first multicast service is stored locally.
  • the mobility management network element may determine that the RRC connection is disconnected between the first terminal and the access network device in the following manner: the access network device or the mobility management network element triggers the execution of the AN release process shown in FIG. After the first terminal disconnects the RRC connection with the access network device, and is in the RRC_idle state or the RRC_inactive state, the access network device sends a UE context release complete message carrying the identification information of the first terminal to the mobility management network element, and the mobility management After receiving the UE context release complete message, the network element determines that the RRC connection is disconnected between the first terminal and the access network device.
  • the access network device determines that the first terminal has disconnected the RRC connection with the access network device and is in the RRC_idle state or the RRC_inactive state, or the access network device determines to release the context of the first terminal, or When the RRC connection of the terminal is released, the access network device sends a UE context release request message or a UE notification message to the mobility management network element. After receiving the UE context release request message or the UE notification message, the mobility management network element determines that the RRC connection is disconnected between the first terminal and the access network device.
  • the first information may include first identification information.
  • the first information can be used to send notification information to the session management network element when the data of the first multicast service reaches the user plane network element, and can also be used to instruct the user plane network element to cache or discard the data of the first multicast service.
  • the session management network element may receive information about deactivating the user plane transmission resources of the terminals in the multicast group corresponding to the first multicast service for the first time or receive the event opening notification sent by the mobility management network element for the first time.
  • the identification information of the user plane network element is obtained from the context of the multicast group, and the first information is sent to the user plane network element according to the identification information of the user plane network element.
  • the sending of the first information by the session management network element to the user plane network element can be understood as: the arrival of the data of the first multicast service to the user plane network element is an event, and the session management network element is the user plane network element.
  • the network element sends the configuration, instruction, or processing rule that satisfies the event, so that the user plane network element triggers the user plane network element according to the configuration or instruction or processing rule issued by the session management network element.
  • a report or notification of the event can be understood as: the arrival of the data of the first multicast service to the user plane network element is an event, and the session management network element is the user plane network element.
  • the network element sends the configuration, instruction, or processing rule that satisfies the event, so that the user plane network element triggers the user plane network element according to the configuration or instruction or processing rule issued by the session management network element.
  • a report or notification of the event can be understood as: the arrival of the data of the first multicast service to the user plane network element is an event, and the session management
  • the session management network element when the session management network element sends the first information to the user plane network element, it can be understood that the session management network element subscribes to the service provided by the user plane network element, for example, the session management network element sends a subscription (subscribe) first multicast service to the user plane network element.
  • the subscription information about the arrival of the data on the user plane network element, the subscription information includes the service type (or trigger condition), when the service type (or trigger condition) is satisfied.
  • the user plane network element will send notification information to the session management network element.
  • sending the first information by the session management network element to the user plane network element may include: the session management network element sends the data containing the first multicast service to the user plane network element and the processing rule of the user plane network element when the data reaches the user plane network element Or a user plane connection establishment request message (such as a packet forwarding control protocol (PFCP) session establishment request (PFCP Session Establishment Request) that indicates or configures or subscribes information, or a user plane connection establishment modification message (such as PFCP Session Modification) Request), or N4 Session Establishment Request (N4 Session Establishment Request) or N4 Session Modification Request (N4 Session Modification Request), in the message.
  • PFCP packet forwarding control protocol
  • PFCP Session Establishment Request a packet forwarding control protocol (PFCP Session Establishment Request) that indicates or configures or subscribes information
  • PFCP Session Modification a user plane connection establishment modification message
  • N4 Session Establishment Request N4 Session Establishment
  • the user When the user plane network element reaches the user plane network element according to the data of the first multicast service, the user The processing rules or instructions or configuration or subscription information of the plane network element, and send reports or notifications to the session management network element, such as sending a user plane connection report request (such as PFCP Session Report Request) or N4 session report request (N4 Session Report Request) carrying notification information. Report Request), or Downlink Data Notification.
  • a user plane connection report request such as PFCP Session Report Request
  • N4 session report request N4 Session Report Request
  • Report Request Downlink Data Notification
  • the first identification information may be used to identify the data of the first multicast service, and the first identification information may be replaced by the identification information described as the first multicast service.
  • the first identification information or the identification information of the first multicast service may include a temporary mobile group identifier (TMGI) of the multicast group corresponding to the first multicast service, or an application server (eg: the AF that provides the data of the first multicast service) the internet protocol (IP) address, or the service identifier (service ID) of the first multicast service, or the data of the first multicast service.
  • TMGI temporary mobile group identifier
  • IP internet protocol
  • service ID service identifier
  • the packet filter (packet filter) information of the first multicast service or one or more of the data flow (service data flow, SDF) identification rules of the data of the first multicast service.
  • Step 502 The user plane network element receives the first information, and receives the data of the first multicast service.
  • the user plane network element is the anchor point of the first multicast service. If the session management network element is the multicast session management network element that manages the multicast session corresponding to the first multicast service, the user plane network element can pass The N4 link between it and the session management network element directly receives the first information from the session management network element; the session management network element is the session management network element that manages the unicast session, and the user plane network element can manage the multicast session by The multicast session management network element receives the first information from the session management network element.
  • the user plane network element may receive data of the first multicast service from the application server.
  • the user plane network element is not the anchor point of the first multicast service. If the session management network element is the multicast session management network element that manages the multicast session corresponding to the first multicast service, the user plane network element can receive The first information of the unicast session management network element corresponding to the user plane network element. The first information is forwarded by the session management network element (ie, the multicast session management network element) to the unicast session management network element. If the session management network element In order to manage the session management network element of the unicast session, the user plane network element may directly receive the first information of the session management network element. The user plane network element may receive data of the first multicast service from the anchor point of the first multicast service.
  • Step 503 The user plane network element sends notification information to the session management network element according to the first information.
  • the session management network element receives the notification information.
  • the notification information may be used to indicate that the data of the first multicast service arrives at the user plane network element.
  • the notification information may include data used to identify the first multicast service, such as the TMGI of the multicast group corresponding to the first multicast service, or the IP address of the application server, or the service identifier of the first multicast service, or the first multicast service identifier.
  • the user plane network element may send an N4 response message to the session management network element, and the N4 response message may carry notification information.
  • the user plane network element may send notification information to the session management network element, and the notification information may carry the notification information.
  • the user plane network element determines, according to the first identification information carried in the first information, the buffer size of the first multicast service arriving at the user plane network element. Therefore, when the user plane network element receives the data of the first multicast service sent by the application server, it will not map the data of the first multicast service to the corresponding QF and send it out. Business data is stored in a buffer.
  • the user plane network element stops sending the first multicast service after receiving the data of the first multicast service. For the data of the multicast service, drop the received data of the first multicast service, or, in order not to affect other connected terminals receiving the data of the first multicast service, the user plane network element continues to send and receive the data of the first multicast service. data of the first multicast service.
  • Step 504 The session management network element sends the second information to the mobility management network element according to the notification information.
  • the session management network element receives the After the notification information, according to the identification information of the first multicast service carried in the notification information, it is determined that the data of the first multicast service has reached the user plane network element, and the session management network element uses the identification information of the first multicast service as an index, Find the context of the multicast group corresponding to the first multicast service, find the terminal in the preset state from the context of the multicast group, and find the terminal in the preset state according to the corresponding relationship between the terminal and the mobility management network element.
  • the mobility management network element corresponding to the terminal respectively sends the information triggering the establishment of the communication connection between the terminal and the access network device.
  • the corresponding relationship between the terminal and the mobility management network element may include the corresponding relationship between the identification information of the terminal and the ID of the mobility management network element, and the corresponding relationship may be saved in the session management network element when the terminal establishes a PDU session superior.
  • the ID of the mobility management network element is used to identify the mobility management network element, and the identification information of the terminal is as described above and will not be repeated.
  • the session management network element may send the second information to the mobility management network element corresponding to the first terminal.
  • the session management network element may correspond to the first terminal.
  • the mobility management network element of the network sends an N1N2 message transfer (Namf_Communication_N1N2Message Transfer), and the N1N2 message transfer carries the second information.
  • the second information may be used to trigger the establishment of a communication connection between the first terminal and the first access network device for transmitting data of the first multicast service, and the second information may include identification information of the first terminal (such as the first terminal). Identification information of a PDU session of a terminal), and N2 interface session management (N2 session management, SM) information.
  • the N2 SM information may become air interface resource configuration information, and is used to allocate air interface resources corresponding to the first multicast service to the first terminal.
  • the N2 SM information may include relevant information of the first multicast service, and the relevant information of the first multicast service is used to trigger the first access network device to allocate air interface resources for the multicast session, and re-join the first terminal to the first multicast session.
  • the multicast group corresponding to the multicast service may include the identification information of the first multicast service, and may also include the quality of service flow identifier ( quality of identifier, QFI), the QoS parameter information corresponding to the QFI of the multicast QoS flow, the information of the unicast QoS flow corresponding to the multicast QoS flow, the QoS profile(s) of the multicast service, and the core network side for sending uplink data
  • the information of the data transmission channel (such as the core network N3 tunnel information (CN N3 tunnel information) and the establishment request or instruction of the multicast session tunnel, etc.
  • the information of the unicast QoS flow can include the QFI and unicast QoS of the unicast QoS flow QoS parameter information corresponding to the flow.
  • QoS parameter information can include QFI, allocation and retention priority information (allocation and retention Priority, ARP), maximum transmission bit rate (maximum flow bit Rate, MFBR), guaranteed bit rate information (guaranteed flow bite) rate, GFBR).
  • ARP allocation and retention priority information
  • MFBR maximum transmission bit rate
  • GFBR guaranteed bit rate information
  • the second information may include the TMGI of the multicast group corresponding to the first multicast service.
  • the session management network element records that there is at least one terminal in a preset state in the multicast group with the multicast group as the granularity, after the session management network element receives the notification information, According to the identification information of the first multicast service carried in the notification information, it is determined that the data of the first multicast service has reached the user plane network element, and according to the identification information of the mobility management network element in step 501 and the identification information of the first multicast service and send the information that triggers the establishment of the communication connection between the terminal and the access network device to the mobility management network element corresponding to the multicast group, and the information can carry the above-mentioned N2 SM information.
  • the information that the session management network element sends to the mobility management network element corresponding to the multicast group to trigger the establishment of the communication connection between the terminal and the access network device may not carry the information of a specific terminal.
  • the identification information may carry the TMGI of the multicast group or the identification information of the first multicast service, and the like.
  • the session management network element may directly send the second information to the mobility management network element, or the first network element or other network elements may send the second information to the mobility management network element.
  • the mobility management network element sends the second information, which is not limited in this application.
  • the session management network element may send a message for triggering the establishment of a communication connection between the terminal and the access network device to other mobility management network elements.
  • information until the information used to trigger the establishment of a communication connection between the terminal and the access network device is sent to the mobility management network elements corresponding to all the terminals in the preset state, so that all the terminals in the preset state are mobility managed
  • the network element is paged, and in the case of switching from the preset state to the RRC connected state, a communication connection with the access network equipment is established.
  • a mobility management network element can manage one or more terminals in a multicast group.
  • the session management network element can send a plurality of second information to the mobility management network element, and the plurality of second information corresponds to a plurality of terminals in a preset state, and a second information includes an identifier of a terminal information, where the second information is used to trigger the establishment of a communication connection between the terminal corresponding to the second information and the first access network device.
  • the session management network element sends a second piece of information to the mobility management network element, and the second information can be used to trigger the establishment of multiple terminals in a preset state and the first terminal.
  • the second information may include identification information of multiple terminals. It should be understood that the identification information of the multiple terminals in the second information can be replaced and described as the second information includes the UE list, and the UE list includes the identification information of the multiple terminals, and the like.
  • the session management network element can send the message to the mobility management network element.
  • Two independent pieces of second information one piece of second information is used to trigger the establishment of a communication connection between the first terminal and the first access network device, and the other piece of second information is used to trigger the establishment of the second terminal and the first access network Communication connection between devices.
  • the session management network element sends a second piece of information to the mobility management network element, where the second information is used to trigger the establishment of a communication connection between the first terminal and the first access network device and the second terminal A communication connection with the first access network device.
  • the session management network element may send information for triggering the establishment of the communication connection between the terminal in the preset state and the access network device to different mobility management network elements at the same time or not at the same time.
  • the mobility management network element manages multiple terminals, and the multiple terminals are in the preset state, the mobility management network element simultaneously or not simultaneously sends a plurality of messages to the mobility management network element for triggering the establishment of multiple terminals and Information on communication connections between access network devices is not limited.
  • the session management network element can send information 1 to mobility management network element 1 and information 2 to mobility management network element 2.
  • Information 1 includes the identification information of UE1 and UE2. The information 1 is used to trigger the establishment of the communication connection between UE1, UE2 and the access network equipment, the information 2 includes the identification information of UE3, and the information 2 is used to trigger the establishment of the communication connection between UE3 and the access network equipment.
  • Step 505 The mobility management network element receives the second information from the session management network element, and sends fifth information to the first access network device according to the second information.
  • the first access network device may be an access network device corresponding to the first terminal, and the first access network device may provide network services for the first terminal.
  • the fifth information may be used by the first access network device to establish a communication connection between the first access network device and the first terminal for transmitting data of the first multicast service.
  • the fifth information may be used to connect The network access device allocates air interface resources corresponding to the first multicast service to the first terminal.
  • the fifth information may carry the N2 SM information carried by the above-mentioned second information, and optionally, may also carry the identification information of the first terminal or the identification information of the first multicast service (such as the multi-item corresponding to the first multicast service).
  • the TMGI of the multicast group, etc.), security configuration information, the security configuration information may include the security configuration information when the data of the first multicast service is transmitted by unicast mode, and the security configuration information when the data of the first multicast service is transmitted by multicast mode.
  • One or more of the configuration information may include N2 SM information, not including security configuration information, and when the first terminal is in an idle state, the air interface resources of the first terminal and the security configuration information of the first terminal are both released, and the fifth information includes N2 SM information and security configuration information.
  • the second information carries the identification information of a terminal, such as the identification information of the first terminal
  • the identification information is an index
  • the preset state of the first terminal is searched from the corresponding relationship between the identification information of the terminal and the state of the terminal.
  • the mobility management network element is based on the registration area of the first terminal. (registration area) Obtaining the paging area, for example, using the registration area of the first terminal as the paging area.
  • the mobility management network element sends a paging message for paging the first terminal to the first access network device corresponding to the paging area.
  • the first access network device receives and broadcasts the paging message.
  • the first terminal detects the paging message, and after establishing the RRC connection, switches its state from the idle state to the connected state, and sends the message to the connected state through the first access network device.
  • the mobility management network element sends a service request message, the mobility management network element receives the service request message sent by the first terminal, and in response to the service request message sent by the first terminal, establishes the mobility management network element and the first terminal.
  • N2 connection between the access network devices so that the state of the terminal becomes the CM connection state, and sends an N2 request (N2 request) to the first access network device, and the N2 request carries the fifth information.
  • the fifth information may carry the above-mentioned N2 SM information and security configuration information.
  • the mobility management network element When the first terminal is in an inactive state, the mobility management network element sends an N2 request to the first access network device, and the N2 request carries fifth information. At this time, the fifth information carries the above N2 SM information, which may not be required. Carry security configuration information.
  • the second information carries the identification information of multiple terminals including the identification information of the first terminal, or the second information carries the TMGI of the multicast group corresponding to the first multicast service
  • the mobility management network element may use the identification information of the terminal carried by the second information as an index to search for the second information from the correspondence between the identification information of the terminal and the state of the terminal.
  • the preset states of multiple terminals corresponding to the information or, the mobility management network element uses the TMGI carried in the second information as an index, searches for the identification information of the terminal corresponding to the TMGI, and obtains the information from the identification information of the terminal and the state of the terminal.
  • the preset states of multiple terminals corresponding to the second information are searched in the corresponding relationship.
  • the mobility management network element performs union of registration areas for the registration areas of the multiple terminals corresponding to the second information, so as to obtain the search result. call area.
  • the present application is not limited to the time sequence in which the first terminal switches its state from the idle state to the connected state, and can switch the state of the first terminal from the idle state to the connected state when the first terminal receives the paging message.
  • the state of the first terminal may also be switched from the idle state to the connected state after the communication connection is established between the first terminal and the access network, and the connected state may refer to the RRC connected state at this time.
  • the mobility management network element may subscribe the first access network device to the status of each terminal in the multicast group, for example, the mobility management network element may send the RRC for subscribing the terminal to the first access network device Status subscription request, the first access network device receives the subscription request, notifies the mobility management network element of the RRC status of the terminal in the subscription response, and the mobility management network element receives the subscription response and saves the terminal identification information and the terminal.
  • the corresponding relationship between the states, the RRC state of the terminal may include the RRC state and the CM state, the CM state includes the CM connected state and the CM idle state, and the RRC state may include the idle state and the inactive state.
  • the mobility management network element may refer to the above process, and send a message to the access network device corresponding to the other terminal in the preset state to instruct the access network device to establish a connection between the terminal and the terminal.
  • Information about the communication connection for example, the second terminal belongs to a terminal in a preset state, the second terminal corresponds to the second access network device, and the mobility management network element sends sixth information to the second access network device according to the second information, The sixth information is used for the second access network device to establish a communication connection with the second terminal until it is sent to the access network devices corresponding to all the terminals in the preset state to instruct the access network device to establish and be in the preset state.
  • Information about the communication connection between the terminals in the state so that all the terminals in the preset state are triggered to establish the communication connection with the access network device.
  • the same access network device may correspond to/serve one or more terminals in a preset state. If the access network device corresponds to/serves multiple terminals in a preset state, the mobility management network element may report to the terminal.
  • the access network device sends a plurality of pieces of information, the pieces of information are in one-to-one correspondence with a plurality of terminals in a preset state, and each piece of information is used to establish a communication connection between the terminal corresponding to the information and the access network device, or , in order to reduce signaling overhead, the mobility management network element may send a piece of information to the access network device, where the piece of information is used to establish communication connections between multiple terminals and the access network device.
  • the mobility management network element can send two independent first and second terminals to the first access network device. Five pieces of information, one piece of fifth information is used to establish a communication connection between the first terminal and the first access network device, and another piece of fifth information is used to establish a communication connection between the second terminal and the first access network device; Or, in order to reduce signaling overhead, the mobility management network element sends a piece of fifth information to the first access network device, where the fifth information is used to establish a communication connection between the first terminal and the first access network device, and to establish A communication connection between the second terminal and the first access network device.
  • Step 506 The first access network device receives the fifth information, and establishes a communication connection with the first terminal according to the fifth information.
  • the first access network device allocates air interface resources corresponding to the first multicast service to the first terminal according to the N2 SM carried by the fifth information, such as the first access network device according to the N2 SM.
  • the unicast QFI carried by the information and the QoS parameter information corresponding to the unicast QFI configure the corresponding data radio bearer (data radio bearer, DRB) for transmitting the data of the first multicast service by unicast mode, and the corresponding data radio bearer (DRB) according to the multicast QFI Configure the corresponding DRB for transmitting the data of the first multicast service through the multicast mode, and send the related information of the configured DRB to the first terminal through the RRC connection reconfiguration or RRC recovery process, so that the first terminal
  • the terminal may receive data of the first multicast service on the DRB. So far, the communication connection with the first terminal is established. Further, if the fifth information carries the security configuration information, the first access network device sends the security configuration information to the first terminal.
  • the RRC connection reconfiguration process may include: the first terminal is in an idle state, the first access network device performs RRC connection reconfiguration with the first terminal, and sends to the first terminal the relevant information carrying the DRB configured by the first access network device Informational RRC reconfiguration message.
  • the RRC recovery process may include: the first terminal is in an inactive state, the first access network device sends a paging message to the first terminal, and the first terminal detects the paging message and switches its state from the inactive state to the connected state , and send an RRC message, such as an RRC recovery request message, to the first access network device, and the first access network device receives the RRC recovery request message and sends an RRC recovery message carrying DRB related information to the first terminal.
  • the first access network device may send a paging message to the first terminal through a first channel
  • the first channel may be any of the following channels: unicast between the first access network device and the first terminal The channel, the common channel, and the dedicated channel of the multicast group corresponding to the first multicast service.
  • the first access network device may establish a communication connection with other terminals by referring to the above method, which will not be repeated.
  • the first access network device sends first indication information to the mobility management network element, and the first indication information can be used to indicate that the establishment of the communication connection between the first terminal and the first access network device is completed.
  • the first indication information may include identification information of the first terminal. If the communication connection between the first access network device and the user plane network element does not exist, and the N2 SM information also includes a request for establishing a multicast session tunnel, the first access network device also allocates the tunnel information of the multicast session, such as Tunnel information of the first access network device, where the tunnel information of the first access network device is used to establish a tunnel/channel for transmitting data of the first multicast service.
  • the first indication information received by the mobility management network element may include the tunnel information of the first access network device, the QFI of the QoS flow of the PDU session, etc., and the mobility management network element sends a message carrying the first access network device to the session management network element.
  • the session management network element receives the PDU session context update request, and performs N4 session update with the user plane network element.
  • the user plane network element establishes a communication between the user plane network element and the first access network device according to the tunnel information of the first access network device. After that, the user plane network element sends an N4 session update response to the session management network element.
  • the first access network device may also indicate to the mobility management network element that the communication connection between the terminal and the first access network device has been established.
  • Indication information for example, taking the second terminal as an example, the first access network device sends second indication information to the mobility management network element, and the second indication information can be used to indicate the connection between the second terminal and the first access network device.
  • the second indication information may include identification information of the second terminal.
  • the first access network device may send an indication message to the mobility management network element, and the response is used to indicate that multiple devices are in a preset state After all the terminals have established a communication connection with the first access network device, the response may include identification information of multiple terminals.
  • the mobility management network element after receiving the first indication information, the mobility management network element sends second indication information to the session management network element according to the first indication information, the second indication information may carry the identification information of the first terminal, and the second indication information may It is used to indicate that the establishment of the communication connection between the first terminal and the first access network device is completed.
  • the mobility management network element receives third indication information from the second access network device, where the third indication information is used to indicate that the establishment of the communication connection between the second terminal and the second access network device is completed, and the mobility management The network element sends fourth indication information to the session management network element according to the third indication information, where the second indication information is used to indicate that the establishment of the communication connection between the second terminal and the second access network device is completed.
  • the mobility management network element may also send an indication message to the session management network element after receiving the indication information sent by the multiple access network devices to indicate that the establishment of the communication connection is completed.
  • the indication information may be used to indicate that all communication connections triggered by the session management network element to request the mobility management network element to be established have been established.
  • the mobility management network element after receiving the first indication information and the second indication information, the mobility management network element sends a piece of indication information to the session management network element according to the first indication information and the second indication information, where the indication information includes the identification information of the first terminal, Identification information of the second terminal, where the indication information is used to indicate that both the communication connection between the first terminal and the first access network device and the communication connection between the second terminal and the first access network device are established, or, The indication information is used to indicate that all communication connections triggered by the session management network element to request the mobility management network element to be established have been established.
  • the mobility management network element sends fifth indication information to the session management network element according to the second preset waiting period, where the fifth indication information is used to instruct the mobility management network element to trigger the establishment of the communication connection established by the mobility management network element.
  • the mobility management network element sends fifth indication information to the session management network element according to the second preset waiting period, and the sending of the indication information to the session management network element may include any one of the following two methods:
  • the second preset waiting period can be set as required, or, if the mobility management network element requests the establishment of multiple access network devices, configure a preset for each access network device of the multiple access network devices duration, and the shortest preset duration is used as the second preset waiting duration.
  • the mobility management network element maintains a timer, and the duration of the timer is the second preset waiting time.
  • the mobility management network element requests the first access network device to establish a communication connection or at some later point.
  • the timer is started at each time, and when the timer runs for the second preset waiting time and expires, the fifth indication information is sent to the session management network element.
  • the management network element sends fifth indication information.
  • Mode 2 If the mobility management network element requests the establishment of multiple access network devices, a timer is set for each access network device of the multiple access network devices, and the timer duration of each access network device is It is the second preset waiting time. For each access network device, start the timer when or after the mobility management network element starts to request the access network device to establish a communication connection, and when the timers of all access network devices expire, report to the session management network The element sends fifth indication information.
  • the session management network element receives indication information sent by the mobility management network element, such as the second indication information, or the fourth indication information or the fifth indication information, and determines that the session management network element requests the mobility management network according to the indication information.
  • indication information sent by the mobility management network element such as the second indication information, or the fourth indication information or the fifth indication information
  • the session management network element When the session management network element receives the indication information sent by the mobility management network element, and determines according to the indication information that the communication connections between all terminals in the multicast group corresponding to the first multicast service and the access network equipment have been established, the session The management network element sends the third information to the user plane network element; or, when the session management network element receives the indication information sent by the mobility management network element, such as the second indication information or the fourth indication information, it is determined according to the indication information that at least one When the communication connection between the terminal in the preset state and the access network device is established, the session management network element sends the third information to the user plane network element; or, after relying on the indication information sent by the mobility management network element, the session management network element The management network element may also send third information to the user plane network element according to the first preset waiting period.
  • the third information may be used to notify the user plane network element to send the data of the first multicast service.
  • the third information may include second identification information, and the second identification information may include the TMGI of the multicast group corresponding to the first multicast service, or the IP address of the application server, or the service identifier of the first multicast service, or the first One or more of the packet filter information of the data of the multicast service or the identification rules of the data of the first multicast service.
  • the session management network element sends the third information to the user plane network element according to the first preset waiting time, which may include any one of the following two methods:
  • the first preset waiting time can be set as required, or, if the session management network element triggers multiple mobility management network elements to establish a communication connection, the first preset waiting time period is set for each mobility management network element of the multiple mobility management network elements. Configure a preset duration, and use the shortest preset duration as the first preset waiting duration.
  • the session management network element maintains a timer, and the duration of the timer is the first preset waiting time.
  • the session management network element triggers the first mobility management network element to establish a communication connection or a certain time after that.
  • the timer is started from time to time, and when the timer runs for the first preset waiting period and expires, the third information is sent to the user plane network element.
  • the session management network element sets a timer for the first second information sent to each mobility management network element, and the timer duration is the first preset waiting duration.
  • the timer is started after the session management network element sends the first second information to the mobility management network element or when the first second information is sent, and when the timer expires
  • the communication connection between all terminals corresponding to the mobility management network element and the first access network device is established, and after the timer corresponding to each mobility management network element expires, determine that all terminals
  • the third information is sent to the user plane network element.
  • the user plane network element receives the third information, and sends the buffered data of the first multicast service according to the third information.
  • the user plane network element can map the data of the first multicast service to the QF, and send it to the first multicast service through the QF.
  • An access network device which is sent to the terminal by the first access network device through the communication connection between the first access network device and the terminal.
  • step 502 is replaced with the user plane network element discarding the received data of the first multicast service according to the first information after receiving the data of the first multicast service
  • the user plane network element receives the third information and can The third information continues to receive the data of the first multicast service resent by the application server, and sends the data of the first multicast service.
  • the session management network element can be triggered to notify the user plane network element corresponding to the multicast service that it has received multiple
  • the session management network element can be triggered to notify the user plane network element corresponding to the multicast service that it has received multiple
  • the session management network element can be triggered to notify the user plane network element corresponding to the multicast service that it has received multiple
  • first cache the data of the multicast service and then trigger the paging of the terminal through the core network equipment, so that the terminal is in the connected state, and establish a communication connection between all the terminals in the multicast group and the access network equipment.
  • the user plane network element to send the received or buffered multicast service data to the terminals in the multicast group through the access network equipment, to ensure that the terminals in the multicast group receive the multicast service data .
  • words such as “first” and “second” are used to distinguish the same items or similar items with basically the same functions and functions.
  • words “first”, “second” and the like do not limit the quantity and execution order, and the words “first”, “second” and the like are not necessarily different.
  • the first multicast service described in this application may be described as a multicast service instead.
  • FIG. 6 is a flowchart of a data transmission method provided by an embodiment of the present application. As shown in FIG. 6 , the method may include:
  • Step 601 UE1 and UE2 respectively establish a PDU session. After UE1 and UE2 establish a PDU session, UE1 and UE2 will further use a PDU session modification request or a multicast group sent by the user plane for joining the corresponding multicast service. , triggers the SMF to establish a channel for transmitting the data of the first multicast service with reference to the method shown in Figure 1a, and selects the QF corresponding to the PDU session of any UE in UE1 and UE2 as the data for transmitting the first multicast service.
  • the QF corresponding to the PDU session of UE2 is selected as the QF used to transmit the data of the first multicast service, or the SMF provides the relevant information about the joining of UE1 and UE2 to the RAN, which triggers the RAN to establish a multicast group.
  • the dedicated channel of the multicast group includes the QF for transmitting the data of the first multicast service.
  • the process of establishing the PDU session between the UE1 and the UE2 may refer to the prior art, which will not be repeated.
  • the SMF can configure the UPF to store the downlink tunnel information of the RAN, the correspondence between the QFIs, and the identification information between the QFI and the multicast service.
  • the context of the multicast group is also stored in the SMF, and the context of the multicast group includes the correspondence between the identification information of the UE in the multicast group, the identification information of the UPF and the identification information of the multicast service.
  • Step 602 UE1 receives the RRC release message sent by the RAN, enters an idle state or an inactive state, and triggers the AMF to send fourth information to the SMF, indicating to deactivate the user plane transmission resources of UE1.
  • step 602 can be referred to as shown in FIG. 2 , which will not be repeated.
  • the UE2 may be in an RRC connected state, and the user plane transmission resources of the UE2 may be in a deactivated state or an activated state, which is not limited.
  • Step 603 The SMF receives the fourth information and sends the first information to the UPF. Accordingly, the UPF receives the first information.
  • the first information is used to configure the UPF to send notification information to the SMF when the data of the first multicast service arrives at the UPF, and further, the first information may also Contains indication information for instructing the UPF to buffer the data of the first multicast service.
  • the process of sending the first information from the SMF to the UPF may be described with reference to step 501 in FIG. 5 , which is not limited.
  • Step 604 The UPF receives and identifies the data of the first multicast service sent by the AS.
  • Step 605 The UPF buffers the received data of the first multicast service according to the first information received in step 603.
  • the UPF may also send the received data of the first multicast service according to the first information received in step 603 or discard the received data of the first multicast service.
  • Step 606 The UPF sends notification information to the SMF.
  • the relevant description of the notification information and the process of sending the notification information to the SMF by the UPF may refer to the description in the embodiment corresponding to FIG. 5 , which will not be repeated.
  • Step 607 The SMF receives the notification information, finds the UE1 according to the notification information, and sends an N1N2 message carrying the second information to the AMF corresponding to the UE1. Accordingly, the AMF receives the N1N2 message delivery.
  • the related description of the second information and the process of sending the N1N2 message carrying the second information by the SMF to the AMF corresponding to the UE1 may refer to the description in the embodiment corresponding to FIG. 5 , and will not be repeated.
  • the SMF may send N11 messages to the one or more AMFs respectively.
  • One AMF corresponds to one N11 message, and one N11 message includes the identification information of the PDU sessions of all UEs in the preset state corresponding to the AMF; or, one AMF corresponds to multiple N11 messages, and one N11 message includes the corresponding AMF in the preset state.
  • the identification information of the PDU sessions of multiple UEs in the set state is not limited.
  • steps 608 to 615 are executed, and the process ends; if the UE1 is in an inactive state, steps 610 to 615 are executed, and the process ends.
  • Step 608 The AMF determines that the UE1 is in an idle state, and the AMF sends a paging message to the UE1 through the RAN.
  • the paging message can be used for paging UE1.
  • the paging message may include identification information of UE1 and the like.
  • Step 609 UE1 receives the paging message and sends a service request message to the AMF.
  • the AMF receives the service request message.
  • the service request message may be used to request the network side to establish the context of the UE and establish the CM connection between the RAN and the network side.
  • the service request message may include security parameters, identification information of the UE, and the like.
  • Step 610 The AMF sends fifth information to the RAN.
  • the fifth information carries N2 SM information, and the relevant description of the fifth information can refer to the description in FIG. 5, and will not be repeated.
  • Step 611 The RAN receives the fifth information, and establishes a communication connection between the RAN and the UE1 according to the fifth information.
  • step 611 may refer to the description of step 506, and details are not repeated.
  • Step 612 The RAN sends the first indication information to the AMF, the AMF receives the first indication information, and sends the second indication information to the SMF according to the first indication information.
  • the first indication information and the second indication information may be used to indicate that the establishment of the communication connection between the RAN and the UE1 is completed.
  • the indication information may also be sent to the SMF by referring to the process shown in step 612 .
  • the indication information may be used to indicate that the communication connections between the UEs in the multicast group corresponding to the AMF and the RAN are all established. It should be noted that when the AMF receives all the indication information returned by the RAN that receives the N2 SM information to indicate the completion of the establishment of the communication connection, it sends a fifth message to the SMF to indicate that the SMF requests that all the communication connections triggered by the AMF are established.
  • the duration of the timer is the above-mentioned second preset waiting duration, when the timer expires, send to the SMF a message indicating that the SMF requests that all communication connections triggered by the AMF have been established. Fifth indication information.
  • the RAN can also send the downlink tunnel information of the RAN to the SMF through the AMF, so that the SMF can transfer the RAN to the SMF.
  • the downlink tunnel information of the RAN is sent to the UPF, and the UPF sends the data of the first multicast service to the RAN according to the downlink tunnel information of the RAN, and the RAN sends the data to the UEs of the multicast group.
  • Step 613 The SMF receives the second indication information, and when the establishment of the communication connection between all UEs in the multicast group or at least one of which is in the preset state and the access network device is completed, or after the first preset waiting period
  • the UPF sends an N4 message, and the N4 message carries the third information.
  • the third information may be used to instruct the UPF to send the data of the first multicast service.
  • the N4 message may further include identification information of the first multicast service, downlink tunnel information of the RAN, and the like.
  • the SMF when it receives all the indication information returned by the AMF that receives the N1N2 message, it sends the N4 message to the UPF, or sets a timer, and the duration of the timer is the above-mentioned first preset waiting time.
  • the N4 message carrying the third information is sent to the UPF without restriction.
  • Step 614 The UPF receives the N4 message, and sends the buffered data of the first multicast service according to the N4 message.
  • step 614 is optional.
  • step 605 if the first information sent by the SMF to the UPF includes information for instructing the UPF to buffer the data of the first multicast service, step 614 is only executed.
  • Step 615 The RAN receives the data of the first multicast service, and sends the data of the first multicast service.
  • the SMF instructs the UPF to cache the data of the first multicast service, so that when some UEs in the multicast group are in an inactive state, the UPF can cache the data of the first multicast service in time. Only when all UEs in the multicast group are in the connected state, the UPF sends the data of the first multicast service. In this way, it can be ensured that all UEs can receive the data of the first multicast service without loss.
  • the method shown in FIG. 5 or FIG. 6 above is to cache the data of the first multicast service by the user plane network element under the instruction of the session management network element when there is a terminal in a preset state in the multicast group, And trigger the paging of the terminal in the preset state, establish the communication connection between the terminal and the access network device, and complete the establishment of the communication connection between the terminal in the preset state and the access network device in the multicast group
  • the data transmission method provided by the embodiment of the present application is described.
  • the RAN may also receive and cache the first multicast service.
  • Multicast service data The method can be referred to as shown in FIG. 7 .
  • FIG. 7 is a flowchart of another data transmission method provided by an embodiment of the present application, as shown in FIG. 7 , which may include:
  • Step 701 The user plane network element sends the data of the first multicast service to the first access network device, and correspondingly, the first access network device receives the data of the first multicast service.
  • the related description of the first multicast service may refer to step 501, which will not be repeated.
  • the first access network device may receive the first multicast service from the user plane network element corresponding to the first multicast service through the downlink transmission tunnel between the first access network device and the user plane network element. data.
  • Step 702 When there is at least one terminal served by the first access network device and in a preset state in the multicast group corresponding to the first multicast service, the first access network device caches the first multicast service The data.
  • the first access network device may determine, through the RRC connection release process shown in FIG. 2 , whether the terminal it serves and is in the multicast group corresponding to the first multicast service is in a preset state, such as the first Taking the terminal as an example, after receiving the RRC release message from the first terminal, the first access network device determines that the first terminal is in a preset state: RRC_idle state or RRC_inactive state according to the RRC release message sent by the first terminal.
  • Step 703 The first access network device sends a paging message to the first terminal. Correspondingly, the first terminal receives the paging message.
  • the paging message may be used to page the first terminal, so that the first terminal switches from a preset state to an RRC connected state, such as switching from an idle state to an RRC connected state, or switching from an inactive state to an RRC state connection state, etc.
  • the first terminal is included in the above at least one terminal in a preset state, and the paging message may include identification information of the first terminal.
  • the identification information of the first terminal is described in the method shown in FIG. 5 and will not be repeated.
  • the first access network device may send a paging message to the first terminal by using a first channel
  • the first channel may include any of the following channels: a single channel between the first access network device and the first terminal; A multicast channel, a common channel, and a dedicated channel of the multicast group corresponding to the first multicast service.
  • the first access network device may also send a paging message to other terminals. For example, if the at least one terminal in the preset state also includes a second terminal, the first access network device The network access device sends a paging message for paging the second terminal to the second terminal. And so on, until the first access network device pages all the terminals in the at least one terminal in the preset state. It should be noted that the first access network device may simultaneously page at least one terminal in a preset state, or may not simultaneously page at least one terminal in a preset state, which is not limited.
  • the method shown in FIG. 7 may also include:
  • Step 704 The first terminal sends a first RRC message to the first access network device.
  • the first access network device receives the first RRC message from the first terminal.
  • the first RRC message may be used to request to establish a communication connection between the first terminal and the first access network device, and the communication connection may be used to transmit data of the first multicast service.
  • the first RRC message is a service request message.
  • the first RRC message may be an RRC recovery request message.
  • the terminal that receives the paging message sent by the first access network device can refer to step 704 and send the first RRC message to the first access network device, requesting the first access network device to establish a paging message with the first access network device. communication connection.
  • Step 705 The first access network device obtains fifth information from the mobility management network element according to the first RRC message.
  • the fifth information may be used to establish a communication connection between the first terminal and the first access network device.
  • the fifth information reference may be made to the description in step 505, and details are not repeated.
  • the fifth information may be N2 SM information
  • the first access network device may obtain the fifth information from the mobility management network element
  • the mobility management network element may obtain the fifth information from the session management network element.
  • the mobility management network element acquiring the fifth information from the session management network element may include: the mobility management network element sending the fourth information for deactivating the user plane transmission resources of the first terminal to the session management network element, and the session management network element receiving the fourth information
  • the fourth information from the mobility management network element takes the fourth information as a trigger condition, and sends fifth information to the mobility management network element in response to the fourth information.
  • the session management network element sends a subscription request to the mobility management network element according to the fourth information, where the subscription request is used to request to subscribe to the first event, and the first event is the transition of the first terminal from the preset state to the connected state; when the session management network When the element receives the first event notified by the mobility management network element, the session management network element sends fifth information to the mobility management network element.
  • the relevant description of the fourth information may refer to the method shown in FIG. 5 , and details will not be repeated.
  • Step 706 The first access network device sends seventh information to the first terminal according to the fifth information.
  • the seventh information is used to indicate the relevant configuration of the communication connection between the first terminal and the first access network device, such as the air interface resource/DRB configured for the first terminal for transmitting the data of the first multicast service, etc. .
  • the first access network device allocates air interface resources corresponding to the first multicast service to the first terminal according to the N2 SM carried by the fifth information, such as the first access network device according to the N2 SM.
  • the unicast QFI carried by the information and the QoS parameter information corresponding to the unicast QFI configure the corresponding DRB used for transmitting the data of the first multicast service in a unicast manner, and configure the corresponding DRB according to the QoS parameter information corresponding to the multicast QFI.
  • the DRB of the data of the first multicast service is transmitted in a multicast manner, and the related information of the configured DRB is sent to the first terminal through the RRC connection reconfiguration or RRC recovery process, so that the first terminal can receive the first multicast service on the DRB.
  • broadcast service data Further, if the fifth information carries the security configuration information, the first access network device sends the security configuration information to the first terminal.
  • terminals may be switched to the connected state with reference to the above process, and a communication connection between other terminals in the preset state and the first access network device may be established, which will not be repeated.
  • the first access network device when there is no terminal served by the first access network device and in a preset state in the multicast group corresponding to the first multicast service, the first access network device sends the cached first broadcast service data.
  • the first access network device sends the cached data of the first multicast service according to the third preset waiting time. For example, if a timer is set, the time of the timer is equal to the third preset waiting time, and the first access network The device starts the timer when it starts paging the terminal, and when the timer runs, it sends the buffered data of the first multicast service. Instead, it needs to wait for the timer to expire before sending the buffered data of the first multicast service. The packet loss problem of the terminals in the multicast group will be reduced as much as possible.
  • the first access network device sets a timer, and does not send the cached data of the first multicast service until the timer expires. Most of the terminals in the multicast group return to the connected state as much as possible and establish communication connections within the timer period, which will reduce the packet loss problem of the terminals in the multicast group as much as possible.
  • the first access network when there is at least one terminal in the multicast group corresponding to the first multicast service that is served by the first access network device and is in a preset state, the first access network can be triggered After the device receives the data of the multicast service, it first buffers the data of the multicast service, and then paging the terminal to make the terminal in the connected state, and establishes communication between all the terminals in the multicast group and the first access network device In the case of connection, the buffered multicast service data is sent to ensure that the terminals in the multicast group receive the multicast service data.
  • FIG. 8a is a flowchart of another data transmission method provided by an embodiment of the present application, as shown in FIG. 8a, which may include:
  • Step 801 UE1 and UE2 respectively establish a PDU session.
  • UE1 and UE2 will further use the PDU session modification request or the message sent by the user plane to join the multicast group corresponding to the multicast service.
  • the QF corresponding to the PDU session of UE2 is selected as the QF for transmitting the data of the first multicast service.
  • step 801 may refer to the description of step 601, which will not be repeated.
  • Step 802 UE1 receives the RRC release message sent by the RAN, enters an idle state or an inactive state, and triggers the AMF to send fourth information to the SMF, indicating to deactivate the user plane transmission resources of UE1.
  • step 802 can refer to the description of step 602, and details are not repeated.
  • the SMF may send the fifth information to the AMF in response to the fourth information, and the AMF receives and saves the fifth information; or, the SMF subscribes the first event to the AMF, and the first event is UE1 from the AMF.
  • the preset state transitions to the connected state.
  • Step 803 The UPF receives and identifies the data of the first multicast service sent by the AS.
  • Step 804 The UPF sends the data of the first multicast service to the RAN.
  • Step 805 The RAN receives the data of the first multicast service, and buffers the data of the first multicast service.
  • the RAN may, according to step 802, learn that there is a UE1 in a preset state in the multicast group, and cache the data of the first multicast service.
  • Step 806 The RAN sends a paging message to UE1.
  • Step 807 UE1 receives the paging message and sends the first RRC message to the RAN.
  • the first RRC message may be a service request message or an RRC recovery request message.
  • Step 808 The RAN receives the first RRC message and obtains the fifth information from the AMF.
  • the fifth information can be entered into a preset state by UE1 in step 802, that is, when the SMF receives the fourth information sent by the AMF, it triggers the SMF to send the fifth information to the AMF in advance, and is stored by the AMF. After the first RRC message, the RAN is triggered to acquire the fifth information from the AMF.
  • the RAN after receiving the first RRC message, notifies the SMF of the first event through the AMF, and triggers the SMF to send the fifth information to the RAN through the AMF, so that the RAN determines the fifth information according to the fifth information.
  • Step 809 The RAN sends the seventh information to UE1 according to the fifth information.
  • the seventh information is used to indicate the relevant configuration of the communication connection between the first terminal and the first access network device, such as the air interface resource/DRB configured for the first terminal for transmitting the data of the first multicast service, etc. .
  • step 809 may refer to the description of step 506, which will not be repeated.
  • Step 810 The RAN determines that there is no UE served by the RAN and is in a preset state in the multicast group corresponding to the first multicast service.
  • the UEs in the multicast group send data of the first multicast service.
  • the RAN caches the data of the first multicast service in time.
  • the RAN sends the data of the first multicast service. In this way, it can be ensured that the UE in all states can receive the data of the first multicast service without loss.
  • the session management network element can use a signaling message to indicate the terminal that joins the multicast group. To the mobility management network element, so that the mobility management network element paging the terminal in the idle state to receive the data of the first multicast service.
  • the method can refer to Figure 8b:
  • FIG. 8b is another data transmission method provided by an embodiment of the present application, as shown in FIG. 8b, which may include:
  • the session management network element sends the UE list of the multicast group to the mobility network element.
  • the mobility management network element receives the UE list of the multicast group.
  • the session management network element may be the SMF in FIG. 3b, and the session management network element may manage the PDU session of the terminal, and the PDU session is associated with the multicast session corresponding to the multicast group.
  • the mobility management network element may be the AMF in Fig. 3b, and a terminal that joins the multicast group may perform network registration through the mobility management network element.
  • the UE list can be used to indicate/correspond to the terminals joining the multicast group.
  • the terminals that join the multicast group described herein may include all the terminals that join the multicast group, and may also include some of the terminals that join the multicast group, for example, may include joining the multicast group and A terminal in a preset state, or a terminal that meets the following conditions among the terminals managed by the session management network element: joins a multicast group, joins a multicast group and is in a preset state, or joins a multicast group and does not A communication connection or the like for transmitting data of the first multicast service is established.
  • the UE list may include identification information of multiple terminals that join the multicast group. It should be noted that the identification information of multiple terminals that join the multicast group included in the UE list may not be the identification information of all the terminals that join the multicast group in the network, but those that send the multicast group to the session management network element.
  • the identification information of the terminal requesting to join the group or in other words, the UE list may correspond to the identification information of the terminal that joins the multicast group stored by the session management network element.
  • the UE list may include the identification information of the first terminal and the identification information of the second terminal, etc.
  • the UE list can be carried in the second information, and the second information can be used to trigger the establishment of a communication connection between the terminal joining the multicast group and the access network device, and the communication connection is used to transmit the data of the first multicast service.
  • the second information may also carry identification information of the multicast group. Specifically, for the related description of the second information, reference may be made to the description in step 504 .
  • the session management network element may receive notification information from the user plane network element for notifying that the data of the first multicast service is received, and send the UE list carrying the multicast group to the mobility network element according to the notification information.
  • second information Specifically, for the implementation process of the session management network element sending the second information, reference may be made to steps 501 to 504 .
  • the mobility management network element determines the terminals in the idle state among the terminals indicated by the UE list, and sends a paging message to the terminals in the idle state.
  • the terminal in the idle state can be paged by means of group paging.
  • the group paging method may include: the mobility management network element determines the terminal in the idle state among the terminals indicated by the UE list, obtains the registration area of the terminal in the idle state, and calculates the number of the terminal in the idle state according to the registration area of the terminal in the idle state. A paging area, where a paging message carrying the identification information of the multicast group is sent in the first paging area.
  • the number of terminals in the idle state may be one or more.
  • the mobility management network element determines that the terminal in the idle state among the terminals indicated by the UE list may include: the mobility management network element may use the identification information of the terminal as an index to find the context of the terminal saved by the mobility management network element.
  • the status information of the terminal in the context of the terminal indicates that the terminal is in an idle state (for example, the context of the terminal contains an idle radio network temporary identifier (I-RNTI), or there is no AMF UE next-generation application in the context of the terminal Protocol ID (AMF UE Next Generation Application Protocol ID, AMF UE NGAP ID), then it is determined that the terminal is in an idle state.
  • I-RNTI idle radio network temporary identifier
  • AMF UE Next Generation Application Protocol ID AMF UE Next Generation Application Protocol ID
  • the paging message may be used for paging a terminal in an idle state.
  • the paging message can carry the identification information of the multicast group.
  • a terminal After the terminal that needs to receive the data of the first multicast service monitors the paging message carrying the identification information of the multicast group on the paging channel, A terminal can transition from an idle state to a connected state.
  • the terminals in the idle state include the first terminal and the second terminal, and the mobility management network element may send a paging message carrying the identification information of the multicast group in the first paging area. Further, if the first terminal is successfully paged, the mobility management network element receives the service request message from the first terminal; and/or if the second terminal is successfully paged, the mobility management network element receives the service request message from the second terminal. service request message.
  • the registration area of each terminal may be configured by a mobility management network element and pre-allocated to the terminal.
  • the registration area of each terminal may include one or more cells, and the registration area of the terminal may include the coverage area of the information area of one or more access network devices.
  • the registration area of UE1 may include the coverage areas of the base stations in Area 1, Area 2, and Area 3.
  • the first paging area includes the registration area of the first terminal and the registration area of the second terminal, that is, the union/complete set of the registration area of the first terminal and the registration area of the second terminal.
  • the first paging area also includes the registration areas of terminals other than the first terminal and the second terminal in the UE list.
  • the first paging area also includes the registration areas of the terminals in the idle state except the first terminal and the second terminal in the UE list, so that group paging can be initiated in the registration areas of more terminals, which is convenient for more The terminal is called to receive the data of the first multicast service.
  • the UE list includes UE1-UE3, and UE1 and UE2 in the idle state will be pre-assigned a registration area.
  • the registration area of UE1 includes areas 1, 2, and 3, and the registration area of UE2 includes areas 2, 3 zone and 4 zones.
  • the method further includes: :
  • the mobility management network element sends information for the access network device to establish a communication connection with the terminal joining the multicast group to the access network device corresponding to these terminals.
  • the access network device may include one or more access network devices that have not established a communication connection for transmitting data of the first multicast service.
  • the mobility management network element sending information to the access network device for the access network device to establish a communication connection with a terminal that joins the multicast group may include: the mobility management network element sends information to one or more access network devices Information for establishing a communication connection with the terminal is respectively sent.
  • the mobility management network element may respectively send fifth information for the first access network device to establish a communication connection with the first terminal to the first access network device, and send the fifth information to the second access network device to the second access network device.
  • the sixth information for the second access network device to establish the communication connection with the second terminal is respectively sent.
  • the present application does not limit the time sequence in which the mobility management network element sends information for the access network device to establish a communication connection with the terminal joining the multicast group to the access network device corresponding to the terminal.
  • the fifth information and the sixth information mentioned above may be sent sequentially, or may be sent at the same time, which is not limited.
  • S8b4 The access network device establishes the communication connection with the terminal according to the information for the access network device to establish the communication connection with the terminal joining the multicast group.
  • S8b4 may refer to the process of establishing the communication connection between the first access network device and the first terminal in step 506, which will not be repeated.
  • a signaling message can be used to trigger group paging in the registration areas of multiple terminals, thereby reducing the paging signaling overhead.
  • the communication connection of the data of the multicast service reduces the signaling overhead.
  • each node such as the session management network element, the mobility management network element, the user plane network element, and the first access network device, etc., in order to implement the above functions, includes hardware structures and/or corresponding hardware structures for performing each function. software module.
  • the present application can be implemented in hardware or in the form of a combination of hardware and computer software, in conjunction with the algorithm steps of the examples described in the embodiments disclosed herein. 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 session management network element, the mobility management network element, the user plane network element, the first access network device, etc. may be divided into functional modules according to the foregoing method examples.
  • each functional module may be divided corresponding to each function, It is also possible to integrate two or more functions in one processing module.
  • the above-mentioned integrated modules can be implemented in the form of hardware, and can also be implemented in the form of software function modules. It should be noted that, the division of modules in the embodiments of the present application is schematic, and is only a logical function division, and there may be other division manners in actual implementation.
  • FIG. 9 is a schematic diagram of the composition of a communication apparatus 90 provided by an embodiment of the present application, and the communication apparatus 90 may be a session management network element or a chip or a system-on-chip in a session management network element.
  • the communication device 90 may include: a sending unit 901 and a receiving unit 902;
  • the sending unit 901 is configured to send, to a user plane network element, when there is at least one terminal in a preset state in a multicast group corresponding to the first multicast service, for the user plane network element to use the first multicast service
  • the first information of the notification information is sent to the session management network element when the data reaches the user plane network element.
  • the sending unit 901 can be used to support the communication apparatus 90 to perform step 501 and step 603 .
  • the receiving unit 902 is configured to receive notification information from the user plane network element that the data representing the first multicast service arrives at the user plane network element.
  • the receiving unit 902 is configured to support the communication device 90 to perform step 504 and step 607 .
  • the sending unit 901 is further configured to send, according to the notification information, to the mobility management network element second information for triggering the establishment of a communication connection between the first terminal and the first access network device, where the first terminal belongs to at least one in a pre-defined state.
  • the terminal that sets the state is configured to support the communication device 90 to perform step 504 and step 607 .
  • the communication apparatus 90 shown in FIG. 9 may include: a processing module and a communication module.
  • the communication module may integrate the functions of the sending unit 901 and the receiving unit 902 .
  • the processing module is used to control and manage the actions of the communication device 90, eg, the processing module is used to support the communication device 90 to perform other processes of the techniques described herein.
  • the communication module is used to support the communication device 90 to perform step 501 , step 504 , step 607 , etc. and communicate with other network entities.
  • the communication device 90 shown in FIG. 9 may further include a storage module for storing program codes and data of the communication device 90 .
  • the processing module may be a processor or a controller. It may implement or execute the various exemplary logical blocks, modules and circuits described in connection with this disclosure.
  • a processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and the like.
  • the communication module may be a transceiver circuit or a communication interface or the like.
  • the storage module may be a memory. When the processing module is a processor, the communication module is a communication interface, and the storage module is a memory, the communication apparatus 90 shown in FIG. 9 may be the communication apparatus 400 shown in FIG. 4 .
  • FIG. 10 is a schematic diagram of the composition of a communication apparatus 100 provided by an embodiment of the present application, and the communication apparatus 100 may be a user plane network element or a chip or a system-on-chip in a user plane network element. As shown in FIG. 10 , the communication apparatus 100 may include: a receiving unit 1001 and a sending unit 1002;
  • a receiving unit 1001 configured to receive first information from the session management network element for the user plane network element to send notification information to the session management network element when the data of the first multicast service reaches the user plane network element; and receive the first information Multicast service data.
  • the receiving unit 1001 is configured to support the communication device 100 to perform step 502 and step 603 .
  • the sending unit 1002 is configured to send notification information to the session management network element according to the first information, where the notification information is used to indicate that the data of the first multicast service arrives at the user plane network element.
  • the sending unit 1002 is configured to support the communication device 100 to perform step 502 , step 605 and step 606 .
  • the communication apparatus 100 shown in FIG. 10 may include: a processing module and a communication module.
  • the communication module may integrate the functions of the receiving unit 1001 and the transmitting unit 1002 .
  • the processing module is used to control and manage the actions of the communication device 100, eg, the processing module is used to support the communication device 100 to perform other processes of the techniques described herein.
  • the communication module is used to support the communication device 100 to perform step 502, step 605, step 606, etc. and communicate with other network entities.
  • the communication apparatus 100 shown in FIG. 10 may further include a storage module for storing program codes and data of the communication apparatus 100 .
  • the processing module is a processor
  • the communication module is a communication interface
  • the storage module is a memory
  • the communication apparatus 100 shown in FIG. 10 may be the communication apparatus 400 shown in FIG. 4 .
  • FIG. 11 is a schematic diagram of the composition of a communication apparatus 110 according to an embodiment of the present application.
  • the communication apparatus 110 may be a mobility management network element or a chip or a system-on-chip in the mobility management network element. As shown in FIG. 11 , the communication apparatus 110 may include: a receiving unit 1101 and a sending unit 1102;
  • the receiving unit 1101 is configured to receive second information from the session management network element, where the second information is used to trigger the establishment of a communication connection between the first terminal and the first access network device, and the communication connection is used to transmit the first multicast service The data.
  • the receiving unit 1101 is configured to support the communication device 110 to perform step 505 and step 607 .
  • the sending unit 1102 is configured to send fifth information to the first access network device according to the second information, where the fifth information is used for the first access network device to establish a communication connection with the first terminal.
  • the sending unit 1102 is configured to support the communication device 110 to perform step 505 and step 610 .
  • the receiving unit 1101 is configured to receive the UE list from the multicast group of the session management network element, the multicast group corresponds to the first multicast service, and the UE list Indicates a terminal to join the multicast group.
  • the receiving unit 1101 is used to support the communication device 110 to perform S8b1.
  • the sending unit 1102 is configured to send a paging message to a terminal in an idle state among the terminals indicated by the UE list.
  • the sending unit 1102 is used to support the communication device 110 to perform S8b2.
  • the communication apparatus 110 shown in FIG. 11 may include: a processing module and a communication module.
  • the communication module may integrate the functions of the receiving unit 1101 and the sending unit 1102 .
  • the processing module is used to support the communication device 110 to control and manage the actions of the communication device 110, and the communication module is used to support the communication device 110 to perform steps 505, 607, 610, S8b1, S8b2, etc. and communicate with other network entities.
  • the communication device 110 shown in FIG. 11 may further include a storage module for storing program codes and data of the communication device 110 .
  • the processing module is a processor
  • the communication module is a communication interface
  • the storage module is a memory
  • the communication apparatus 110 shown in FIG. 11 may be the communication apparatus 400 shown in FIG. 4 .
  • FIG. 12 is a schematic diagram of the composition of a communication apparatus 120 according to an embodiment of the present application.
  • the communication apparatus 120 may be a first access network device or a chip or a system-on-chip in the first access network device. As shown in FIG. 12 , the communication apparatus 120 may include: a receiving unit 1201, a processing unit 1202, and a sending unit 1203;
  • the receiving unit 1201 is configured to receive data of the first multicast service.
  • the receiving unit 1201 may support the communication device 120 to perform step 701 and step 805 .
  • the processing unit 1202 is configured to cache data of the first multicast service when there is at least one terminal served by the first access network device and in a preset state in the multicast group corresponding to the first multicast service.
  • the processing unit 1202 may support the communication device 120 to perform step 702 and step 805 .
  • the sending unit 1203 is configured to send a paging message for paging a first terminal, where the first terminal belongs to at least one terminal served by the first access network device and in a preset state.
  • the sending unit 1203 can support the communication apparatus 120 to perform step 703 and step 806 .
  • the receiving unit 1201 can also be used to receive an RRC message from the first terminal, where the RRC message is used to request the establishment of a communication connection between the first terminal and the first access network device, and the communication connection is used to transmit the first multiple broadcast service data.
  • the receiving unit 1201 may support the communication device 120 to perform step 704 and step 808.
  • the sending unit 1203 may also be configured to send the seventh information to the first terminal.
  • the sending unit 1203 may support the communication apparatus 120 to perform steps 705 and 809 .
  • the communication apparatus 120 shown in FIG. 12 may include: a processing module and a communication module.
  • the processing module may integrate the functions of the processing unit 1202
  • the communication module may integrate the functions of the receiving unit 1201 and the sending unit 1203 .
  • the processing module is used to support the communication device 120 to perform steps 702 and 805 and to control and manage the actions of the communication device 120.
  • the communication module is used to support the communication device 120 to perform steps 701, 805, 703, 806, 705, and 705. 809, etc. and communications with other network entities.
  • the communication device 120 shown in FIG. 12 may further include a storage module for storing program codes and data of the communication device 120 .
  • the processing module is a processor
  • the communication module is a communication interface
  • the storage module is a memory
  • the communication apparatus 120 shown in FIG. 12 may be the communication apparatus 400 shown in FIG. 4 .
  • FIG. 13 is a schematic diagram of the composition of a communication system provided by an embodiment of the present application.
  • the communication system may include a terminal 130 , an AMF 131 , an SMF 132 , a RAN 133 and a UPF 134 .
  • the function of the SMF 132 is the same as that of the communication device 90 .
  • the UPF 134 has the same function as the communication device 100 .
  • the AMF 131 has the same function as the communication device 110 .
  • the RAN 133 has the same function as the communication device 120 .
  • the SMF 132 is configured to send the first information to the UPF 134 when there is at least one terminal 130 in a preset state in the multicast group corresponding to the first multicast service, and the UPF 134 is the first An anchor point corresponding to a multicast service, and the first information is used to instruct the UPF 134 to send notification information to the session management network element when the data of the first multicast service reaches the user plane network element.
  • the UPF 134 is configured to receive the first information from the SMF 132. When the data of the first multicast service arrives at the UPF 134, the UPF 134 sends notification information to the SMF 132, and the notification information is used to indicate that the data of the first multicast service arrives at the UPF 134.
  • the SMF 132 is further configured to receive notification information returned by the UPF 134, and send second information to the AMF 131 according to the notification information, where the second information is used to trigger the establishment of a communication connection between the first terminal 130 and the RAN 133, and the first terminal 130 is included in at least one Among the terminals 130 in a preset state, a terminal managed by a mobility network element.
  • the AMF 131 is configured to receive the second information from the SMF 132, and send fifth information to the RAN 133 according to the second information, the second information is used to trigger the establishment of a communication connection between the first terminal 130 and the RAN 133, and the fifth information is used to instruct the RAN 133 A communication connection between the RAN 133 and the first terminal 130 is established.
  • the RAN 133 is used to receive the data of the first multicast service, and when there is at least one multicast group served by the RAN 133 and in a preset state in the multicast group corresponding to the first multicast service.
  • the terminal 130 When the terminal 130 is used, the data of the first multicast service is buffered, and a paging message for paging the first terminal 130 is sent to the first terminal 130 .
  • the SMF132 is used to send the UE list of the multicast group to the AMF131, the multicast group corresponds to the first multicast service, and the UE list indicates the terminals that join the multicast group.
  • AMF131 is used to receive the user equipment list UE list of the multicast group from SMF132, and the multicast group corresponds to the first multicast service, and sends a paging message to the terminal in the idle state in the terminal indicated by the UE list.
  • each network element in FIG. 13 reference may be made to the execution steps of the corresponding network element in the method in FIG. 5 to FIG. 8 b , which will not be repeated.
  • Embodiments of the present application also provide a computer-readable storage medium. All or part of the processes in the above method embodiments can be completed by instructing the relevant hardware by a computer program, the program can be stored in the above computer-readable storage medium, and when the program is executed, it can include the processes in the above method embodiments.
  • the computer-readable storage medium may be the terminal device of any of the foregoing embodiments, such as: an internal storage unit including a data sending end and/or a data receiving end, such as a hard disk or a memory of the terminal device.
  • the above-mentioned computer-readable storage medium can also be an external storage device of the above-mentioned terminal device, such as a plug-in hard disk equipped on the above-mentioned terminal device, a smart memory card (smart media card, SMC), a secure digital (secure digital, SD) card, Flash card (flash card), etc. Further, the above-mentioned computer-readable storage medium may also include both an internal storage unit of the above-mentioned terminal device and an external storage device.
  • the above-mentioned computer-readable storage medium is used for storing the above-mentioned computer program and other programs and data required by the above-mentioned terminal device.
  • the above-mentioned computer-readable storage medium can also be used to temporarily store data that has been output or is to be output.
  • the embodiments of the present application also provide a computer instruction. All or part of the processes in the foregoing method embodiments may be completed by computer instructions to instruct relevant hardware (such as computers, processors, network devices, and terminals, etc.).
  • the program can be stored in the above-mentioned computer-readable storage medium.
  • connection in the embodiments of the present application, refers to various connection modes such as direct connection or indirect connection, so as to realize communication between devices, which is not limited in the embodiments of the present application.
  • transmission in the embodiments of the present application refers to bidirectional transmission, including the actions of sending and/or receiving.
  • transmission in the embodiments of the present application includes data transmission, data reception, or data transmission and data reception.
  • the data transmission here includes uplink and/or downlink data transmission.
  • Data may include channels and/or signals, uplink data transmission is uplink channel and/or uplink signal transmission, and downlink data transmission is downlink channel and/or downlink signal transmission.
  • Network and “system” appearing in the embodiments of this application express the same concept, and a communication system is a communication network.
  • At least one item (a) of a, b, or c may represent: a, b, c, ab, ac, bc, or abc, where a, b, and c may be single or multiple .
  • words such as “exemplary” or “for example” are used to represent examples, illustrations, or illustrations. Any embodiments or designs described in the embodiments of the present application as “exemplary” or “such as” should not be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as “exemplary” or “such as” is intended to present the related concepts in a specific manner to facilitate understanding.
  • the disclosed apparatus and method may be implemented in other manners.
  • the device embodiments described above are only illustrative.
  • the division of the modules or units is only a logical function division. In actual implementation, there may be other division methods.
  • multiple units or components may be Incorporation may either be integrated into another device, or some features may be omitted, or not implemented.
  • the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.
  • the units described as separate components may or may not be physically separated, and components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place, or may be distributed to multiple different places . Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.
  • each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into 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.
  • the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it may be stored in a readable storage medium.
  • the technical solutions of the embodiments of the present application can be embodied in the form of software products in essence, or the parts that contribute to the prior art, or all or part of the technical solutions, which are stored in a storage medium , including several instructions to make a device, such as a single chip microcomputer, a chip, etc., or a processor (processor) execute all or part of the steps of the methods described in the various embodiments of the present application.
  • the aforementioned storage medium includes: a U disk, a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disk and other mediums that can store program codes.

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Abstract

本申请实施例公开了一种数据传输方法、装置以及系统，以解决多播群组中处于预设状态的终端不能接收到多播业务的数据的问题。该方法应用于第一多播业务对应的多播群组中存在至少一个处于预设状态的终端的情况下，包括：会话管理网元通知用户面网元在第一多播业务的数据到达用户面网元时向会话管理网元发送通知信息，会话管理网元接收到通知信息后，触发建立处于预设状态的终端与接入网设备之间的通信连接，通信连接建立完成后通知用户面网元发送第一多播业务的数据；或者，接入网设备接收到第一多播业务的数据后，缓存第一多播业务的数据，寻呼处于预设状态的终端，在终端与接入网设备之间的通信连接建立完成后，发送缓存的第一多播业务的数据。

Description

一种数据传输方法、装置以及系统
本申请要求于2020年7月23日提交国家知识产权局、申请号为202010718875.0、申请名称为“一种数据传输方法、装置以及系统”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请实施例涉及通信技术领域，尤其涉及一种数据传输方法、装置以及系统。
背景技术
第三代合作伙伴计划(3rd generation partnership project，3GPP)网络中，存在网络侧设备通过同一通信连接向多个终端(如一个多播群组中的终端)发送多播业务的数据的需求，即点对多点的数据传输需求。
为了满足这种需求，现有技术中发往多个终端的多播业务的数据共享同一用户面功能(user plane function，UPF)以及共享该UPF与接入网设备之间的下行隧道，该下行隧道可以为多个终端对应的多个下行隧道中的任一下行隧道，用于标识该下行隧道的下行隧道信息存储在UPF。应用服务器将多播业务的数据发送给UPF后，UPF可以根据本地存储的下行隧道信息，通过该下行隧道将多播业务的数据发送到接入网设备，由接入网设备发送给多个终端。
然而，通信过程中，终端可以处于连接态或者空闲态或者非激活态。当有多播业务需求的终端处于空闲态或者非激活态时，该终端与接入网设备之间的通信连接断开，无法接收到接入网设备发送的多播业务的数据，进而无法保证多播群组中的所有终端接收到多播业务的数据。
发明内容
本申请实施例提供一种数据传输方法、装置以及系统，以解决处于空闲态或者非激活态的终端不能接收到多播业务的数据的问题。
为达到上述目的，本申请实施例采用如下技术方案。
本申请实施例的第一方面，提供一种数据传输方法，所述方法包括：在第一多播业务对应的多播群组中存在至少一个处于预设状态的终端的情况下，会话管理网元向用户面网元发送用于用户面网元在第一多播业务的数据到达用户面网元时向会话管理网元发送通知信息的第一信息，会话管理网元接收来自用户面网元的用于表征第一多播业务的数据到达用户面网元的通知信息，根据通知信息，向移动性管理网元发送用于触发建立第一终端与第一接入网设备之间的通信连接的第二信息，第一终端属于至少一个处于预设状态的终端；
其中，预设状态包括空闲态，非激活态，或者与接入网设备之间不存在用于传输第一多播业务的数据的通信连接。
基于第一方面所述的方法，会话管理网元可以在多播业务对应的多播群组中存在至少一个处于预设状态的终端的情况下，向用户面网元发送第一信息，指示用户面网元在第一多播业务的数据到达用户面网元时向会话管理网元发送通知信息，后续，第 一多播业务的数据到达用户面网元的通知后，触发建立处于预设状态的终端与接入网设备之间的通信连接，以便通信连接建立完成后，通过接入网设备与终端的通信连接，向多播群组中的终端发送第一多播业务的数据，避免因终端处于预设状态，终端与接入网设备与终端之间的用于传输多播业务的数据的通信连接断开，终端无法接收到多播业务的数据的问题，保证多播群组中的终端都可以无丢失的接收到多播业务的数据。
一种可能的设计中，对于属于至少一个处于预设状态的其他终端，如第二终端，第二信息还用于触发建立第二终端与第二接入网设备之间的通信连接。基于该可能的设计，可以通过一条信息触发建立多个终端与接入网设备之间的通信连接，降低信令开销。
一种可能的设计中，第一信息包括用于识别第一多播业务的数据的第一识别信息。基于该可能的设计，将用于指示第一多播业务的数据的识别信息携带在第一信息中，向用户面网元显式指示在第一多播业务的数据到达用户面网元时向会话管理网元发送通知信息，无需用户面网元根据第一信息间接地确定要向会话管理网元发送通知信息，简化系统设计。
一种可能的设计中，所述方法还包括：当第一多播业务对应的多播群组中所有终端均存在与接入网设备之间的通信连接时，会话管理网元向用户面网元发送用于通知用户面网元发送第一多播业务的数据的第三信息。如此，保证多播群组中的所有终端均无丢失的接收到多播业务的数据。
一种可能的设计中，所述方法还包括：当至少一个处于预设状态的终端中所有终端均存在与接入网设备之间的通信连接时，会话管理网元向用户面网元发送用于通知用户面网元发送第一多播业务的数据的第三信息。如此，至少保证处于预设状态的所有终端与接入网设备之间的通信连接建立完成，通过通信连接接收到多播业务的数据。
一种可能的设计中，在向移动性管理网元发送第二信息之后，所述方法还包括：会话管理网元根据第一预设等待时长，向用户面网元发送用于通知用户面网元发送第一多播业务的数据的第三信息。基于该可能的设计，可以为会话管理网元向用户面网元发送第三信息预先设计等待时长，当等待时长到期后，就向用户面网元发送第三信息，简化系统设计。
一种可能的设计中，第三信息包括用于识别第一多播业务的数据的第二识别信息。基于该可能的设计中，将用于识别第一多播业务的数据的识别信息携带在第三信息中显式指示给用户面网元，以便用户面网元直接根据该识别信息获知要发送第一多播业务的数据，无需用户面网元间接地确定要发送第一多播业务的数据，简化用户面网元的设计复杂度。
一种可能的设计中，所述方法还包括：会话管理网元接收来自移动性管理网元的用于去激活第一终端的用户面传输资源的第四信息，根据第四信息确定第一终端处于预设状态。基于该可能的设计，可以在终端处于预设状态的情况下，进一步的通过向会话管理网元发送去激活用户面传输资源的信息，使得会话管理网元获知该用户面传输资源对应的终端处于预设状态，简化系统设计。
第二方面，本申请提供一种通信装置，该通信装置可以为会话管理网元上的会话管理网元或者会话管理网元中的芯片或者片上系统。该通信装置可以实现上述第一方 面或者第一方面可能的设计中通信装置所执行的功能，所述功能可以通过硬件实现，也可以通过硬件执行相应的软件实现。所述硬件或软件包括一个或多个上述功能相应的模块。如：该通信装置可以包括：发送单元，接收单元；
发送单元，用于在第一多播业务对应的多播群组中存在至少一个处于预设状态的终端的情况下，向用户面网元发送用于用户面网元在第一多播业务的数据到达用户面网元时向会话管理网元发送通知信息的第一信息；
接收单元，用于接收来自用户面网元的用于表征第一多播业务的数据到达用户面网元的通知信息；
发送单元，还用于根据通知信息，向移动性管理网元发送用于触发建立第一终端与第一接入网设备之间的通信连接的第二信息，第一终端属于至少一个处于预设状态的终端。
其中，预设状态包括空闲态，非激活态，或者与接入网设备之间不存在用于传输第一多播业务的数据的通信连接。该通信装置的各个单元的具体实现方式可以参考第一方面或第一方面的任一种可能的设计提供的数据传输方法中会话管理网元的行为功能，在此不再重复赘述。该提供的通信装置可以达到与第一方面或者第一方面的任一种可能的设计相同的有益效果。
第三方面，提供了一种通信装置，包括：处理器和存储器；该存储器用于存储计算机执行指令，当该通信装置运行时，该处理器执行该存储器存储的该计算机执行指令，以使该通信装置执行如上述第一方面或者第一方面的任一种可能的设计所述的数据传输方法。
第四方面，提供了一种计算机可读存储介质，该计算机可读存储介质中存储有指令，当其在计算机上运行时，使得计算机可以执行上述第一方面或者上述方面的任一种可能的设计所述的数据传输方法。
第五方面，提供了一种包含指令的计算机程序产品，当其在计算机上运行时，使得计算机可以执行上述第一方面或者上述方面的任一种可能的设计所述的数据传输方法。
第六方面，提供了一种通信装置，该通信装置可以为芯片系统，该芯片系统可以包括处理器、通信接口，用于支持通信装置实现上述第一方面或者第一方面的任一种可能的设计中所涉及的功能，例如在第一多播业务对应的多播群组中存在至少一个处于预设状态的终端的情况下，处理器通过通信接口向用户面网元发送用于用户面网元在第一多播业务的数据到达用户面网元时向会话管理网元发送通知信息的第一信息，接收来自用户面网元的用于表征第一多播业务的数据到达用户面网元的通知信息，根据通知信息，向移动性管理网元发送用于触发建立第一终端与第一接入网设备之间的通信连接的第二信息，第一终端属于至少一个处于预设状态的终端。在一种可能的设计中，所述芯片系统还包括存储器，所述存储器，用于保存通信装置必要的程序指令和数据。该芯片系统，可以由芯片构成，也可以包含芯片和其他分立器件。
其中，第三方面至第六方面中任一种设计方式所带来的技术效果可参见上述第一方面或者第一方面的任一种可能的设计所带来的技术效果，不再赘述。
第七方面，本申请实施例提供又一种数据传输方法，该方法可以包括：用户面网 元接收来自会话管理网元的用于用户面网元在第一多播业务的数据到达用户面网元时向会话管理网元发送通知信息的第一信息，接收第一多播业务的数据后，根据第一信息向会话管理网元发送用于表征第一多播业务的数据到达用户面网元的通知信息，以便会话管理网元接收到该通知消息后，触发建立处于预设状态的终端与接入网设备之间的通信连接，保证处于预设状态的终端无丢失地通过通信连接接收到第一多播业务的数据。
基于第七方面所述的方法，在多播业务对应的多播群组中存在至少一个处于预设状态的终端的情况下，用户面网元可以在会话管理网元的指示下，在数据到达用户面网元时通知会话管理网元，以便会话管理网元触发建立处于预设状态的终端与接入网设备之间的通信连接，使得通信连接建立完成后，通过接入网设备与终端的通信连接，向多播群组中的终端发送第一多播业务的数据，避免因终端处于预设状态，终端与接入网设备与终端之间的用于传输多播业务的数据的通信连接断开，终端无法接收到多播业务的数据的问题，保证多播群组中的终端都可以无丢失的接收到多播业务的数据。
一种可能的设计中，所述方法还包括：用户面网元接收到第一多播业务的数据后，缓存第一多播业务的数据，以便后续通信连接建立完成后，发送缓存的第一多播业务的数据。这样，在第一多播业务的数据到达用户面网元时，通过缓存方式将数据保存下来，避免处于预设状态的终端错过(或无法接收到)该时段内下发的第一多播业务的数据的问题。
一种可能的设计中，第一信息包括用于识别第一多播业务的数据的第一识别信息，即通过显式的识别信息指示用户面网元监测第一多播业务的数据是否到达，并在第一多播业务的数据到达时通知会话管理网元，简化系统设计。
一种可能的设计中，所述方法还包括：用户面网元接收来自会话管理网元的用于通知用户面网元发送第一多播业务的数据的第三信息，根据第三信息，发送第一多播业务的数据，即在通信连接建立完成之后，会话管理通知用户面网元下发第一多播业务的数据时再下发多播业务的数据，避免多播业务的数据发送失败。
一种可能的设计中，第三信息包括用于识别第一多播业务的数据的第二识别信息，即通过显式的识别信息指示用户面网元下发第一多播业务的数据，简化系统设计。
第八方面，提供一种通信装置，该通信装置可以为用户面网元或者用户面网元中的芯片或者片上系统。该通信装置可以实现上述第七方面或者第七方面的可能的设计中用户面网元所执行的功能，所述功能可以通过硬件实现，也可以通过硬件执行相应的软件实现。所述硬件或软件包括一个或多个上述功能相应的模块。如：该通信装置可以包括：接收单元、发送单元；
接收单元，用于接收来自会话管理网元的用于用户面网元在第一多播业务的数据到达用户面网元时向会话管理网元发送通知信息的第一信息；以及接收第一多播业务的数据；
发送单元，用于根据第一信息，向会话管理网元发送通知信息，通知信息用于表征第一多播业务的数据到达用户面网元。
其中，该通信装置的具体实现方式可参考第七方面或第七方面的任一种可能的设计提供的数据传输方法中用户面网元的行为功能，第七方面或者第七方面的任一种可 能的设计方法可以由该通信装置包括的接收单元以及发送单元对应实现。
第九方面，提供了一种通信装置，包括：处理器和存储器；该存储器用于存储计算机执行指令，当该通信装置运行时，该处理器执行该存储器存储的该计算机执行指令，以使该通信装置执行如上述第七方面或者第七方面的任一种可能的设计所述的数据传输方法。
第十方面，提供了一种计算机可读存储介质，该计算机可读存储介质中存储有指令，当其在计算机上运行时，使得计算机可以执行上述第七方面或者上述方面的任一种可能的设计所述的数据传输方法。
第十一方面，提供了一种包含指令的计算机程序产品，当其在计算机上运行时，使得计算机可以执行上述第七方面或者上述方面的任一种可能的设计所述的数据传输方法。
第十二方面，提供了一种芯片系统，该芯片系统包括处理器、通信接口，用于支持通信装置实现上述方面中所涉及的功能，例如处理器通过通信接口接收来自会话管理网元的用于用户面网元在第一多播业务的数据到达用户面网元时向会话管理网元发送通知信息的第一信息；以及接收第一多播业务的数据，根据第一信息，向会话管理网元发送通知信息，通知信息用于表征第一多播业务的数据到达用户面网元。在一种可能的设计中，所述芯片系统还包括存储器，所述存储器，用于保存通信装置必要的程序指令和数据。该芯片系统，可以由芯片构成，或者包含芯片和其他分立器件。
其中，第九方面至第十二方面中任一种设计方式所带来的技术效果可参见上述第七方面或者第七方面的任一种可能的设计所带来的技术效果，不再赘述。
第十三方面，还提供一种数据传输方法，该方法包括：移动性管理网元接收来自会话管理网元的用于触发建立第一终端与第一接入网设备之间的通信连接的第二信息，根据第二信息，向第一接入网设备发送用于第一接入网设备建立与第一终端之间的通信连接的第五信息。基于第十三方面所述的方法，移动性管理网元可以在会话管理网元的触发下向第一接入网设备发送第二信息，以使得第一接入网设备建立其与第一终端之间的通信连接，实现第一接入网设备通过该通信连接向第一终端发送第一多播业务的数据，保证第一终端无丢失地接收到第一多播业务的数据。
一种可能的设计中，移动性管理网元接收来自第一接入网设备的用于指示第一终端与第一接入网设备之间的通信连接建立完成的第一指示信息，根据第一指示信息向会话管理网元发送用于指示第一终端与第一接入网设备之间的通信连接建立完成的第二指示信息，即移动性管理网元接收到接入网设备发送的通信连接建立完成的信息即向会话管理网元发送指示信息，以便会话管理网元获知多播群组中哪些终端的通信连接建立完成，简化系统设计。
一种可能的设计中，第二信息还用于触发建立第二终端与第二接入网设备之间的通信连接，所述方法还包括：移动性管理网元根据第二信息，向第二接入网设备发送用于第二接入网设备建立与第二终端之间的通信连接的第六信息，即通过一条第二信息触发建立多个通信连接，降低信令开销。
一种可能的设计中，所述方法还包括:移动性管理网元接收来自第二接入网设备的用于指示第二终端与第二接入网设备之间的通信连接建立完成的第三指示信息，根据 第三指示信息，向会话管理网元发送用于指示第二终端与第二接入网设备之间的通信连接建立完成的第四指示信息，类似的，对于其他接入网设备发送的通信连接建立完成的指示，移动性管理网元接收到接入网设备发送的通信连接建立完成的指示即向会话管理网元发送指示信息，以便会话管理网元获知多播群组中哪些终端的通信连接建立完成，简化系统设计。
一种可能的设计中，移动性管理网元根据第二预设等待时长，向会话管理网元发送用于指示会话管理网元触发移动性管理网元建立的通信连接均建立完成的第五指示信息。即为移动性管理网元设置一预设等待时长，当预设等待时长到期时，通知会话管理网元通信连接建立完成，保证在预设等待时长内尽可能多的通信连接建立完成，以避免因不同接入网设备下的不同终端的通信连接建立速度不同，出现最先建立完成通信连接的接入网设备触发多播业务的数据下发，影响其他通信连接建立较慢的接入网设备下的终端丢包的问题。
一种可能的设计中，当第一终端处于空闲态时，移动性管理网元向第一接入网设备发送第五信息之前，所述方法还包括：移动性管理网元向第一接入网设备发送用于寻呼第一终端的寻呼消息，移动性管理网元接收来自第一终端的业务请求消息，即在终端处于CM连接态的情况下，再向接入网设备发送建立通信连接的第五信息，保证通信连接建立的准确性。
应理解，为降低信令开销，会话管理网元在接收到用户面网元的接收到第一多播业务的数据的通知信息后，可以通过一条信令消息将加入多播群组的终端指示给移动性管理网元，以便移动性管理网元将处于空闲态的终端寻呼起来接收第一多播业务的数据。具体如下：移动性管理网元接收来自会话管理网元的多播群组的终端设备列表UE list，多播群组与第一多播业务对应，UE list指示加入多播群组的终端；移动性管理网元确定所述UE list指示的终端中处于空闲态的终端，向所述处于空闲态的终端发送寻呼消息。即通过一条信令消息触发寻呼多个终端，降低信令开销。
一种可能的设计中，UE list携带在第二信息中，第二信息还可以包括多播群组的标识信息，以便移动性管理网元获知为哪个多播群组的终端发起寻呼，向处于空闲态的终端发送携带多播群组的标识信息的寻呼消息，以便处于空闲态的终端在接收到带有多播群组的标识信息的寻呼消息时，可以获知自己是否需要发起业务请求(service request)流程。
一种可能的设计中，所述处于空闲态的终端包括所述第一终端和所述第二终端，所述移动性管理网元向所述处于空闲态的终端发送寻呼消息包括：所述移动性管理网元在第一寻呼区域发送寻呼消息；其中，所述寻呼消息包括所述多播群组的标识信息，所述第一寻呼区域包括所述第一终端的注册区域和所述第二终端的注册区域。如此可以通过组寻呼方式寻呼多个终端，降低寻呼信令开销。
一种可能的设计中，所述方法还包括：移动性管理网元接收来自第一终端的业务请求消息；和/或移动性管理网元接收来自第二终端的业务请求消息。
一种可能的设计中，第一寻呼区域还包括UE list中除第一终端以及第二终端之外的终端的注册区域。或者，第一寻呼区域还包括UE list中除第一终端以及第二终端之外的处于空闲态的终端的注册区域，如此可以在更多的终端的注册区域发起组寻呼， 便于更多的终端被呼起接收第一多播业务的数据。
第十四方面，本申请提供一种通信装置，该通信装置可以为移动性管理网元或者移动性管理网元中的芯片或者片上系统。该通信装置可以实现上述第十三方面或者第十三方面的可能的设计中移动性管理网元所执行的功能，所述功能可以通过硬件实现，也可以通过硬件执行相应的软件实现。所述硬件或软件包括一个或多个上述功能相应的模块。如：该通信装置可以包括：接收单元、发送单元、处理单元；
一种可能的设计中，接收单元，用于接收来自会话管理网元的第二信息，第二信息用于触发建立第一终端与第一接入网设备之间的通信连接，通信连接用于传输第一多播业务的数据；
发送单元，用于根据第二信息，向第一接入网设备发送第五信息，第五信息用于第一接入网设备建立与第一终端之间的通信连接。
又一种可能的设计中，接收单元，用于接收来自会话管理网元的多播群组的用户设备列表UE list，所述多播群组与第一多播业务对应，所述UE list指示加入所述多播群组的终端。处理单元，用于确定所述UE list指示的终端中处于空闲态的终端；发送单元，用于向所述处于空闲态的终端发送寻呼消息。
其中，该通信装置的具体实现方式可参考第十三方面或第十三方面的任一种可能的设计提供的数据传输方法中移动性管理网元的行为功能，第十三方面或者第十三方面的任一种可能的设计方法可以由该通信装置包括获取单元以及发送单元对应实现。
第十五方面，提供了一种通信装置，包括：处理器和存储器；该存储器用于存储计算机执行指令，当该通信装置运行时，该处理器执行该存储器存储的该计算机执行指令，使通信装置执行如上述第十三方面或第十三方面的任一种可能的设计所述的数据传输方法。
第十六方面，提供了一种计算机可读存储介质，该计算机可读存储介质中存储有指令，当其在计算机上运行时，使得计算机可以执行上述第十三方面或者上述方面的任一种可能的设计所述的数据传输方法。
第十七方面，提供了一种包含指令的计算机程序产品，当其在计算机上运行时，使得计算机可以执行上述第十三方面或者上述方面的任一种可能的设计所述的数据传输方法。
第十八方面，提供了一种芯片系统，该芯片系统包括处理器、通信接口，用于支持通信装置实现上述方面中所涉及的功能，例如处理器通过通信接口接收来自会话管理网元的用于触发建立第一终端与第一接入网设备之间的通信连接的第二信息，根据第二信息，向第一接入网设备发送用于第一接入网设备建立与第一终端之间的通信连接的第五信息。在一种可能的设计中，所述芯片系统还包括存储器，所述存储器，用于保存通信装置必要的程序指令和数据。该芯片系统，可以由芯片构成，也可以包含芯片和其他分立器件。
其中，第十五方面至第十八方面中任一种设计方式所带来的技术效果可参见上述第十三方面或者第十三方面的任一种可能的设计所带来的技术效果，不再赘述。
第十九方面，还提供一种数据传输方法，该方法包括：第一接入网设备接收第一多播业务的数据，当在第一多播业务对应的多播群组中存在至少一个由第一接入网设 备服务，且处于预设状态的终端时，第一接入网设备缓存第一多播业务的数据，发送用于寻呼第一终端的寻呼消息，第一终端属于至少一个由第一接入网设备服务，且处于预设状态的终端，其中，预设状态包括空闲态，非激活态，或者与接入网设备之间不存在用于传输第一多播业务的数据的通信连接。
基于第十九方面所述的方法，第一接入网设备在其下服务的终端处于非连接态的情况下，先缓存接收到的第一多播业务的数据，并向终端发起呼叫，使得终端被寻呼起切换到连接态下时再下发多播业务的数据，保证终端无丢失的接收到多播业务的数据。
一种可能的设计中，所述方法还包括：第一接入网设备接收来自第一终端的用于请求建立第一终端与第一接入网设备之间的通信连接的第一RRC消息，根据第一RRC消息，从移动性管理网元获取用于建立第一终端与第一接入网设备之间的通信连接的第五信息，第一接入网设备根据第五信息，向第一终端发送用于指示所述第一终端与所述第一接入网设备之间的通信连接的相关配置的第七信息，即在接收到第一终端的建立通信连接的请求时，再获取第五信息，根据第五信息为终端进行空口资源等配置，并将配置指示给终端，在通信连接建立完成的同时，简化系统设计。
一种可能的设计中，所述方法还包括：当在第一多播业务对应的多播群组中不存在由第一接入网设备服务，且处于预设状态的终端时，第一接入网设备发送已缓存的第一多播业务的数据，或者，第一接入网设备根据第三预设等待时长，发送已缓存的第一多播业务的数据，即在第一接入网设备服务下的全部终端对应的通信连接完成，或者，在预设等待时长到期时发送缓存的多播业务的数据，尽可能地保证较多的终端接收到多播业务的数据。
一种可能的设计中，第一RRC消息为业务请求消息或者RRC恢复请求消息，即上述应用场景是在第一终端处于空闲态或者非连接态下进行，应用场景灵活多样，适应性较好。
一种可能的设计中，第一接入网设备向第一终端发送寻呼消息包括：第一接入网设备通过第一信道向第一终端发送寻呼消息，第一信道包括以下任意一种：第一接入网设备与第一终端之间的单播信道、公用信道、第一多播业务对应的多播群组的专用信道，即可以通过多种信道中任一信道发送寻呼消息，灵活多样，适应性较好。
第二十方面，本申请提供一种通信装置，该通信装置可以为第一接入网设备或者第一接入网设备中的芯片或者片上系统。该通信装置可以实现上述第十九方面或者第十九方面的可能的设计中第一接入网设备所执行的功能，所述功能可以通过硬件实现，也可以通过硬件执行相应的软件实现。所述硬件或软件包括一个或多个上述功能相应的模块。如：该通信装置可以包括：接收单元、处理单元、发送单元；
接收单元，用于接收第一多播业务的数据；
处理单元，用于当在第一多播业务对应的多播群组中存在至少一个由第一接入网设备服务，且处于预设状态的终端时，缓存第一多播业务的数据；
发送单元，用于发送用于寻呼第一终端的寻呼消息，第一终端属于至少一个由第一接入网设备服务，且处于预设状态的终端。
其中，该通信装置的具体实现方式可参考第十九方面或第十九方面的任一种可能 的设计提供的数据传输方法中第一接入网设备的行为功能，第十九方面或者第十九方面的任一种可能的设计方法可以由该通信装置包括获取单元以及发送单元对应实现。
第二十一方面，提供了一种通信装置，包括：处理器和存储器；该存储器用于存储计算机执行指令，当该通信装置运行时，该处理器执行该存储器存储的该计算机执行指令，使通信装置执行如第十九方面或第十九方面的任一种可能的设计所述的数据传输方法。
第二十二方面，提供了一种计算机可读存储介质，该计算机可读存储介质中存储有指令，当其在计算机上运行时，使得计算机可以执行上述第十九方面或者上述方面的任一种可能的设计所述的数据传输方法。
第二十三方面，提供了一种包含指令的计算机程序产品，当其在计算机上运行时，使得计算机可以执行第十九方面或者上述方面的任一种可能的设计所述的数据传输方法。
第二十四方面，提供了一种芯片系统，该芯片系统包括处理器、通信接口，用于支持通信装置实现上述方面中所涉及的功能，例如处理器通过通信接口接收第一多播业务的数据，当在第一多播业务对应的多播群组中存在至少一个由第一接入网设备服务，且处于预设状态的终端时，缓存第一多播业务的数据，并发送用于寻呼第一终端的寻呼消息，第一终端属于至少一个由第一接入网设备服务，且处于预设状态的终端。在一种可能的设计中，所述芯片系统还包括存储器，所述存储器，用于保存通信装置必要的程序指令和数据。该芯片系统，可以由芯片构成，也可以包含芯片和其他分立器件。
其中，第二十一方面至第二十四方面中任一种设计方式所带来的技术效果可参见上述第十九方面或者第十九方面的任一种可能的设计所带来的技术效果，不再赘述。
本申请实施例的第二十五方面，提供一种数据传输方法，所述方法包括：会话管理网元接收来自移动性管理网元用于去激活第一终端的用户面传输资源的第四信息，根据第四信息，向移动性管理网元发送用于建立第一终端与第一接入网设备之间的通信连接的第二信息，即在第一终端的用户面资源去激活的情况下，将建立通信连接的第二信息发送给移动性管理网元，以便移动性管理网元根据第二信息为终端配置空口资源等，保证终端基于为其配置的空口资源无丢失地接收多播业务的数据。
一种可能的设计中，会话管理网元向移动性管理网元发送第二信息包括：会话管理网元向移动性管理网元发送用于请求订阅第一事件的订阅请求，第一事件为第一终端从预设状态转换到连接态；会话管理网元接收来自移动性管理网元事件通知信息，事件通知信息用于通知第一事件；会话管理网元根据事件通知信息，向移动性管理网元发送第二信息，即通过订阅过程发送第二信息，简化系统设计。
第二十六方面，本申请提供一种通信装置，该通信装置可以为会话管理网元上的会话管理网元或者会话管理网元中的芯片或者片上系统。该通信装置可以实现上述第二十五方面或者第二十五方面可能的设计中通信装置所执行的功能，所述功能可以通过硬件实现，也可以通过硬件执行相应的软件实现。所述硬件或软件包括一个或多个上述功能相应的模块。如：该通信装置可以包括：接收单元，发送单元；
接收单元，用于接收来自移动性管理网元的用于去激活第一终端的用户面传输资 源的第四信息；
发送单元，用于根据第四信息，向移动性管理网元发送用于建立第一终端与第一接入网设备之间的通信连接的第二信息。
其中，该通信装置的各个单元的具体实现方式可以参考第二十五方面或第二十五方面的任一种可能的设计提供的数据传输方法中会话管理网元的行为功能，在此不再重复赘述。该提供的通信装置可以达到与第二十五方面或者第二十五方面的任一种可能的设计相同的有益效果。
第二十七方面，提供了一种通信装置，包括：处理器和存储器；该存储器用于存储计算机执行指令，当该通信装置运行时，该处理器执行该存储器存储的该计算机执行指令，以使该通信装置执行如上述第二十五方面或者第二十五方面的任一种可能的设计所述的数据传输方法。
第二十八方面，提供了一种计算机可读存储介质，该计算机可读存储介质中存储有指令，当其在计算机上运行时，使得计算机可以执行上述第二十五方面或者上述方面的任一种可能的设计所述的数据传输方法。
第二十九方面，提供了一种包含指令的计算机程序产品，当其在计算机上运行时，使得计算机可以执行上述第二十五方面或者上述方面的任一种可能的设计所述的数据传输方法。
第三十方面，提供了一种通信装置，该通信装置可以为芯片系统，该芯片系统可以包括处理器、通信接口，用于支持通信装置实现上述第二十五方面或者第二十五方面的任一种可能的设计中所涉及的功能，例如处理器通过通信接口接收来自移动性管理网元的用于去激活第一终端的用户面传输资源的第四信息，根据第四信息，向移动性管理网元发送用于建立第一终端与第一接入网设备之间的通信连接的第二信息。在一种可能的设计中，所述芯片系统还包括存储器，所述存储器，用于保存通信装置必要的程序指令和数据。该芯片系统，可以由芯片构成，也可以包含芯片和其他分立器件。
其中，第二十七方面至第三十方面中任一种设计方式所带来的技术效果可参见上述第二十五方面或者第二十五方面的任一种可能的设计所带来的技术效果，不再赘述。
第三十一方面，提供一种通信系统，该通信系统可以包括如第二方面至第六方面任一方面所述的通信装置或芯片系统，如第八方面至第十二方面任一方面所述的通信装置或芯片系统，以及第十四方面至第十八方面任一方面所述的通信装置或芯片系统；或者，
该通信系统可以包括如第二十方面至第二十四方面任一方面所述的通信装置或芯片系统，以及第二十六方面至第三十方面任一方面所述的通信装置或芯片系统。
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图1a为一种“伪广播”方式示意图；
图1b为又一种“伪广播”方式示意图；
图1c为又一种“伪广播”方式示意图；
图2为接入网释放流程示意图；
图3a为一种通信系统的架构示意图；
图3b为一种5G通信系统的架构示意图；
图4为本申请实施例提供的一种通信装置400的组成示意图；
图5为本申请实施例提供的一种数据传输方法的流程图；
图6为本申请实施例提供的一种数据传输方法的流程图；
图7为本申请实施例提供的又一种数据传输方法的流程图；
图8a为本申请实施例提供的又一种数据传输方法的流程图；
图8b为本申请实施例提供的又一种数据传输方法的流程图；
图9为本申请实施例提供的一种通信装置90的组成示意图；
图10为本申请实施例提供的一种通信装置100的组成示意图；
图11为本申请实施例提供的一种通信装置110的组成示意图；
图12为本申请实施例提供的一种通信装置120的组成示意图；
图13为本申请实施例提供的一种通信系统的组成示意图。
具体实施方式
通信系统中，在网络侧设备向多个终端(如同一多播群组的多个终端)发送多播业务的多播业务的数据的场景中，为了提高资源利用率，采用“伪广播”方式传输多播业务的数据，“伪广播”方式可以指发往多个终端的多播业务的数据在UPF和/或接入网设备合并。
例如，图1a为发往多个终端的多播业务的数据在UPF和接入网设备合并的示意图，如图1a所示，UPF将接收到的发往多个终端的多播业务的数据合并成一份多播业务的数据后，通过一条通信连接发送给接入网设备，接入网设备接收到该份多播业务的数据后，利用组无线网络临时标识(radio network temporary identifier，RNTI)对该份多播业务的数据进行编码处理后广播给多个终端，无需由UPF通过多条通信连接将多份多播业务的数据发送给接入网设备，由接入网设备将多份多播业务的数据通过多条通信连接发送给多个终端，提高资源利用率。
又例如，图1b为发往多个终端的多播业务的数据在接入网设备合并的示意图，如图1b所示，UPF将发往多个终端的多份多播业务的数据发送给接入网设备，接入网设备接收到的多份多播业务的数据后，将该多份多播业务的数据合并为一份多播业务的数据，利用组RNTI对合并的多播业务的数据进行编码处理后广播给多个终端，无需由接入网设备将多份多播业务的数据通过多条通信连接发送给多个终端，提高资源利用率。
图1a所示的伪广播方式中，UPF与接入网设备之间用于传输多播业务的数据的通信连接可以为多播群组中任一终端的单播协议数据单元(protocol data unit，PDU)会话所对应的通信连接。例如如图1c所示，多播群组中存在三个终端：终端1、终端2以及终端3，每个终端建立有PDU会话，所有终端的PDU会话对应同一UPF，一个PDU会话包括UPF与接入网设备之间的通信连接、以及接入网设备与终端之间的通信连接。向这三个终端发送多播业务的数据之前，可以预先从三个终端的PDU会话选择一个PDU会话，如图1c所示的终端2的PDU会话，UPF接收到应用服务器发送的多播业务的数据之后，将该多播业务的数据映射到终端2的PDU会话对应的服务质量流(QoS flow，QF)，并确定该PDU会话对应的接入网设备的下行隧道信息，根据接入 网设备的下行隧道信息将映射到QF的多播业务的数据发送给接入网设备，由接入网设备将接收到的多播业务的数据发送给这三个终端，提高资源利用率。
需要说明的是，本申请实施例所述的通信连接还可以替换描述为下行传输隧道。终端的PDU会话可以替换描述为终端的单播PDU会话。其中，接入网设备的下行隧道信息可以用于建立UPF与接入网设备之间的通信连接，接入网设备的下行隧道信息可以包括接入网设备的因特网协议(internet protocol，IP)地址和/或接入网设备的隧道端点标识(tunnel endpoint identifier，TEID)。终端的PDU会话建立完成之后，会话管理网元可以将该终端的PDU会话对应的接入网设备的下行隧道信息以及该PDU会话的服务质量流(QoS flow identifier，QFI)对应存储在UPF，以便UPF根据接入网设备的下行隧道信息与QFI之间的对应关系将映射到QF的多播业务的数据发送给该下行隧道信息所指示的接入网设备。
图1a所示方式中，若被选择的PDU会话对应的终端，如终端2，处于预设状态(如空闲态或者非激活态)，则被选择的PDU会话被释放，UPF与接入网设备之间可能断开通信连接，同时从UPF的本地存储中删除接入网设备的下行隧道信息。此时，若UPF仍需要通过该PDU会话传输多播业务的数据，则UPF在发现本地不存在与多播业务的数据对应的QF对应的接入网设备的下行隧道信息时，可以触发接入网设备或者核心网设备发起针对该终端的寻呼，寻呼成功后将接入网设备的下行隧道信息配置在UPF上，以便UPF重新根据接入网设备的下行隧道信息将多播业务的数据发送接入网设备，由接入网设备发送给多个终端。但是，这种方式仅能使得寻呼成功的终端以及多个终端中其他处于无线资源控制(radio resource control，RRC)连接态的终端接收到多播业务的数据，对于有多播业务的数据需求、但又处于预设状态的终端因断开与接入网设备的通信连接，而无法接收到多播业务的数据，无法满足“伪广播”方式中所有终端接收多播业务的数据的需求。类似的，在图1b所示方式中，若多播群组存在有多播业务的数据需求、但又处于预设状态的终端，则这类终端会因断开与接入网设备的通信连接而无法接收到多播业务的数据，无法满足“伪广播”方式中多播群组中的所有终端接收多播业务的数据的需求。
例如，如图1c所示，假设终端2、终端3处于空闲态，终端1处于RRC连接态，选择的终端2的PDU会话传输多播业务的数据，终端2的PDU会话对应的接入网设备的下行隧道信息从UPF上删除。此时，若UPF仍需要通过终端2的PDU会话传输多播业务的数据，则UPF寻呼终端2，在寻呼终端2成功后，终端2的PDU会话对应的接入网设备的下行隧道信息又重新配置在UPF上，UPF根据接入网设备的下行隧道信息将多播业务的数据发送给接入网设备，由接入网设备发送给终端1、终端2，而终端3因处于空闲态，终端3与接入网设备之间的通信连接断开，导致终端3无法接收到多播业务的数据。
为解决该技术问题，本申请中，在多播群组中存在至少一个处于预设状态(如空闲态或者非激活态)的终端的情况下，由会话管理网元指示用户面网元在第一多播业务的数据达到用户面网元是向会话管理网元发送通知信息，并在会话管理网元接收到通知信息时触发寻呼处于预设状态的终端，以便当处于预设状态的终端或者多播群组中的所有终端中不存在任意一个处于预设状态的终端后，指示用户面网元发送第一多 播业务的数据。或者，在多播群组包括的与第一接入网设备对应的终端处于预设状态的情况下，第一接入网设备接收第一多播业务的数据后，先缓存第一多播业务的数据，同时，由第一接入网设备寻呼处于预设状态的终端，触发终端建立与第一接入网设备之间的通信连接，并当多播群组中的终端中不存在任意一个处于预设状态的终端后，再将缓存的第一多播业务的数据下发下去。如此，保证多播群组中的终端都接收到第一多播业务的数据。
其中，本申请所述的预设状态可以包括空闲(idle)态、非激活态或者与接入网设备之间不存在用于传输第一多播业务的数据的通信连接中的任一种状态，还可以包括接入网设备与用户面网元之间不存在用于传输第一多播业务的数据的通信连接等。接入网设备之间不存在用于传输多播业务的数据的通信连接可以理解为第一多播业务对应的多播会话上下文信息在接入网设备侧被释放/删除/移除等，接入网设备与用户面网元之间不存在用于传输第一多播业务的数据的通信连接可以理解为用户面网元释放多播会话对应的传输隧道，如删除本地存储的接入网设备的隧道信息、删除/移除/释放本地存储的第一多播业务对应的N4上下文等。
其中，本申请所述的连接态可以替换描述为非空闲态，对核心网设备(如移动性管理网元、会话管理网元)而言，连接态可以包括无线接入控制(radio resource control，RRC)连接(RRC_connected)态和连接管理(connection management，CM)连接(CM_connected)态，或者，连接态可以包括非激活态和CM连接态。对于接入网设备而言，连接态可以包括RRC连接态。
RRC连接态可以指终端和接入网设备之间存在RRC连接，CM连接态可以指终端与核心网设备(如移动性管理网元)之间存在非接入层(non-access stratum，NAS)信令连接，接入网设备与核心网设备之间存在N2连接。RRC连接态以及CM连接态下，接入网设备、核心网设备都保存有终端的上下文。接入网设备知道该终端在接入网设备的覆盖范围内或者在该接入网设备的管理范围内。核心网设备知道通过哪个接入网设备可以定位到或者找到该终端。在连接态下，终端可以和接入网设备进行下行数据和/或上行数据传输。
空闲(idle)态可以指终端和接入网设备之间没有RRC连接。空闲态可以称为RRC_idle态。空闲态时，接入网设备中未保存终端的上下文，终端与核心网设备(如移动性管理网元)之间不存在NAS信令连接，接入网设备与核心网设备(如移动性管理网元)之间不存在N2连接，核心网设备保存有终端的上下文。接入网设备不知道该终端是否在该接入网设备的覆盖范围内。核心网设备不知道终端在哪个接入网设备的覆盖范围内或者管理范围内，接入网设备不知道通过哪个接入网设备可以定位到或者找到终端。
非激活(inactive)态可以称为RRC_inactive态，非激活态可以指终端和接入网设备之间没有RRC连接，非激活态时，终端与核心网设备(如移动性管理网元)之间不存在NAS信令连接，接入网设备与核心网设备(如移动性管理网元)之间存在N2接口连接。接入网设备中保存有终端的上下文，核心网设备中可以保存有终端的上下文。接入网设备不知道该终端驻留在该接入网设备的覆盖范围内的具体小区或者否在该接入网设备的管理范围内，核心网设备知道终端在哪个接入网设备的覆盖范围内或者管 理范围内，核心网设备知道通过哪个接入网设备可以定位到或者找到该终端。
其中，上述RRC_connected、RRC_idle态、RRC_inactive三种状态之间可以相互转换。在终端选择待接入的小区之后、未接入该小区对应的接入网设备之前，终端可以通过RRC建立过程与接入网设备成功建立RRC连接，接入该小区，进入RRC_connected态，同时，触发接入网设备与移动性管理网元之间建立CM连接。在RRC_connected态时，若终端长时间内没有数据传输需求，接入网设备可以通过RRC释放过程使得终端的状态从RRC_connected态转换为RRC_idle态或者RRC_inactive态。例如，如图2所示，接入网设备在一段定时间内没有接收到终端的上行或者下行数据，在这种情况下，接入网设备会确定释放该终端的上下文，接入网设备向移动性管理网元发送请求释放终端的上下文的用户设备(user equipment，UE)上下文释放请求，移动性管理网元接收UE上下文释放请求，向接入网设备发送UE上下文释放命令，接入网设备接收UE上下文释放命令，向终端发送用于请求终端释放RRC连接的RRC释放(RRC release)消息，终端接收到RRC释放消息后，断开与接入网设备之间的RRC连接，从RRC_connected态或者RRC_inactive态进入RRC_idle态，接入网设备向移动性管理网元发送UE上下文释放完成消息，移动性管理网元接收到UE上下文释放完成消息，进一步可选地，如果终端当前有活动的用户面上下文，移动性管理网元会通知对应的会话管理网元去激活用户面传输资源。在上述流程执行完毕之后，移动性管理网元会认为终端处于CM空闲态。
进一步的，图2所示方法中，为了提高资源利用率，在终端建立PDU会话的情况下，还包括终端的用户面传输资源去激活/释放过程，如：接入网设备向移动性管理网元发送的UE上下文释放完成消息携带有终端的PDU会话的ID，移动性管理网元接收到接入网设备发送的UE上下文释放完成消息后，向管理该PDU会话的会话管理网元发送PDU会话去激活指示，会话管理网元接收到该PDU会话去激活指示后，通知用户面网元删除终端的数据与QF之间的对应关系以及QF与下行隧道信息之间的对应关系，释放用户面传输资源。图2所示过程可参照现有技术，不予赘述。
在RRC_idle态时，终端可以通过RRC建立过程使得终端的状态从RRC_idle态转换为RRC_connected态，如接入网设备可以向终端发送寻呼(paging)消息，终端接收到寻呼消息、并确定自己被寻呼到后，触发终端发起RRC建立过程，试图和接入网设备建立RRC连接以进入RRC_connected态。若成功建立RRC连接，则终端进入RRC_connected态，若RRC连接建立失败，终端继续停留在RRC_idle态。在RRC_inactive时，终端可以从接入网设备接收到寻呼消息，确定自己被寻呼到后，通过RRC恢复(resume)过程试图恢复和接入网设备间的RRC连接以进入RRC_connected态，如终端向接入网设备发送RRC恢复请求(resume resquest)消息，接入网设备接收到RRC恢复请求消息后，向终端发送RRC建立消息或者RRC恢复(resume)消息，使终端的状态可以转换为RRC_connected态。在RRC_inactive时，接入网设备可以通过RRC释放过程，使得终端的状态从RRC_inactive态转换为RRC_idle态，如接入网设备向终端发送RRC释放消息，使终端的状态从RRC_inactive态转换为RRC_idle态；或者，接入网设备向终端发送RRC拒绝消息，使终端继续停留在RRC_inactive态。
需要说明的是，接入网设备上保存的终端的上下文与核心网设备上保存的终端的 上下文不同，接入网设备保存的终端的上下文与终端的数据传输有关，接入网设备保存的终端的上下文可以包括终端的标识信息、服务质量策略(QoS profile)，核心网设备上保存的终端的上下文是与终端的移动和注册相关的上下文，如核心网设备保存的终端的上下文可以包括终端的标识信息、终端的位置信息、终端的注册区域、终端当前的CM连接状态等等。其中，终端的标识信息可以用于标识终端。终端的标识信息可以为终端的因特网协议(internet protocol，IP)地址、终端的媒体接入控制(media access control，MAC)地址、终端的国际移动用户识别码(international mobile subscriber identity，IMSI)、终端的PDU会话的标识中任一标识信息，终端的标识还可以为未来通信标准中出现的其他能够标识终端的信息，如会话管理上下文标识(SM context ID)等，不予限制。
下面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。
本申请实施例提供的数据传输方法可应用于图3a所示的通信系统，如图3a所示，该通信系统可以包括多个终端、移动性管理网元、会话管理网元、接入网设备、用户面网元。进一步的，图3a所示通信系统还可以包括数据网络(data network，DN)，DN可以包括应用服务器(application server，AS)。下面对图3a所示架构中涉及的网元或设备进行介绍。
终端，可以是用于实现无线通信功能的设备，例如终端或者可用于终端中的芯片等。其中，终端可以是5G网络或者未来演进的通信系统中的UE、接入终端、终端单元、终端站、移动站、移动台、远方站、远程终端、移动设备、无线通信设备、终端代理或终端装置等。接入终端可以是蜂窝电话、无绳电话、会话启动协议(session initiation protocol，SIP)电话、无线本地环路(wireless local loop，WLL)站、个人数字处理(personal digital assistant，PDA)、具有无线通信功能的手持设备、计算设备或连接到无线调制解调器的其它处理设备、车载设备或可穿戴设备，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(industrial control)中的无线终端、无人驾驶(self driving)中的无线终端、远程医疗(remote medical)中的无线终端、智能电网(smart grid)中的无线终端、运输安全(transportation safety)中的无线终端、智慧城市(smart city)中的无线终端、智慧家庭(smart home)中的无线终端等。终端可以是移动的，也可以是固定的。
接入网设备，主要用于实现物理层功能、资源调度和管理、终端的接入控制以及移动性管理等功能。接入网设备可以为支持有线接入的设备，也可以为支持无线接入的设备。示例性，接入网设备可以为接入网(access network，AN)/无线接入网(radio access network，RAN)，由多个5G-AN/5G-RAN节点组成。5G-AN/5G-RAN节点可以为：接入点(access point，AP)、基站(nodeB，NB)、增强型基站(enhance nodeB，eNB)、下一代基站(NR nodeB，gNB)、传输接收点(transmission reception point，TRP)、传输点(transmission point，TP)或某种其它接入节点等。
移动性管理网元，主要负责终端的接入认证、移动性管理、各个功能网元之间的信令交互等工作，如：对用户的注册状态、用户的连接状态、用户注册入网、跟踪区更新、小区切换用户认证和密钥安全等进行管理。
会话管理网元，主要用于实现用户面传输逻辑通道，如PDU会话的建立、释放和 更改等会话管理功能。
用户面网元，可以作为用户面传输逻辑通道上的锚点，用于完成用户面数据的路由转发等功能，如：与终端之间建立通道(即用户面传输逻辑通道)，在该通道上转发终端和DN间的数据包、负责对终端的数据报文过滤、数据转发、速率控制、生成计费信息。
DN，可以为用户提供数据传输服务的运营商网络，如：可以为向用户提供因特网协议(internet protocol，IP)多媒体业务(IP multi-media service，IMS)的运营商网络等。DN中可以部署有AS，该应用服务器可以向用户提供数据传输服务。
需要说明的是，图3a仅为示例性架构图，除图3a中所示功能单元外，该系统还可以包括其他功能网元，如：操作和管理(operation and management，O&M)网元等，本申请实施例对此不进行限定。此外，图3a中各个设备的名称不受限制，除图3a所示名称之外，各个设备还可以命名为其他名称，如替换成具备相同或相似功能的网元名称，不予限制。
其中，图3a所示系统可以为第三代合作伙伴计划(3rd generation partnership project，3GPP)通信系统，如第4代(4th generation，4G)通信系统、长期演进(long term evolution，LTE)系统，又可以为第五代(5th generation，5G)通信系统或者新空口(new radio，NR)系统、下一代通信系统等，也可以为非3GPP通信系统，不予限制。
以图3a所示的通信系统为图3b所示的5G通信系统为例，如图3b所示，上述会话管理网元所对应的网元或者实体可以为5G通信系统中的会话管理功能(session management function，SMF)，上述用户面网元所对应的网元或者实体可以为5G通信系统中的用户面功能(user plane function，UPF)，接入网设备对应的网元或者实体可以为5G通信系统中的无线接入网(radio access network，RAN)、移动性管理网元对应的网元或者实体可以为5G通信系统中的接入和移动性管理功能(access and mobility management function，AMF)。
可选的，本申请实施例中的会话管理网元以及移动性管理网元也可以称之为通信装置，其可以是一个通用设备或者一个专用设备，本申请实施例对此不作具体限定。
可选的，本申请实施例中的会话管理网元、用户面网元、接入网设备的相关功能可以由一个设备实现，也可以由多个设备共同实现，还可以是由一个设备内的一个或多个功能模块实现，本申请实施例对此不作具体限定。可以理解的是，上述功能既可以是硬件设备中的网络元件，也可以是在专用硬件上运行的软件功能，或者硬件与软件的结合，或者平台(例如，云平台)上实例化的虚拟化功能。
在具体实现时，图3a所示各设备(如会话管理网元、用户面网元、移动性管理网元、接入网设备等)都可以采用图4所示的组成结构，或者包括图4所示的部件。图4为本申请实施例提供的一种通信装置400的组成示意图，该通信装置400可以包括处理器401和存储器404。进一步的，该通信装置400还可以包括通信线路402以及通信接口403。其中，处理器401，存储器404以及通信接口403之间可以通过通信线路402连接。
处理器401，可以是中央处理器(central processing unit，CPU)、通用处理器、网络处理器(network processor，NP)、数字信号处理器(digital signal processing， DSP)、微处理器、微控制器、可编程逻辑器件(programmable logic device，PLD)或它们的任意组合。处理器401还可以是其它具有处理功能的装置，如电路、器件或软件模块，不予限制。
通信线路402，用于在通信装置400所包括的各部件之间传送信息。
通信接口403，用于与其他设备或其它通信网络进行通信。该其它通信网络可以为以太网，无线接入网(radio access network，RAN)，无线局域网(wireless local area networks，WLAN)等。通信接口403可以是模块、电路、收发器或者任何能够实现通信的装置。
存储器404，用于存储指令。其中，指令可以是计算机程序。
其中，存储器404可以是只读存储器(read-only memory，ROM)或可存储静态信息和/或指令的其他类型的静态存储设备，也可以是随机存取存储器(random access memory，RAM)或可存储信息和/或指令的其他类型的动态存储设备，还可以是电可擦可编程只读存储器(electrically erasable programmable read-only memory，EEPROM)、只读光盘(compact disc read-only memory，CD-ROM)或其他光盘存储、光碟存储(包括压缩光碟、激光碟、光碟、数字通用光碟、蓝光光碟)、磁盘存储介质、其他磁存储设备，不予限制。
需要说明的是，存储器404可以独立于处理器401存在，也可以和处理器401集成在一起。存储器404可以用于存储指令或者程序代码或者一些数据等。存储器404可以位于通信装置400内，也可以位于通信装置400外，不予限制。
处理器401，用于执行存储器404中存储的指令，以实现本申请下述实施例提供的数据传输方法。例如，当通信装置400为会话管理网元或者会话管理网元中的芯片或者片上系统时，处理器401执行存储器404中存储的指令，以实现本申请下述实施例中会话管理网元所执行的步骤。又例如，当通信装置400为移动性管理网元或者移动性管理网元中的芯片或者片上系统时，处理器401可以执行存储器404中存储的指令，以实现本申请下述实施例中移动性管理网元所执行的步骤。
在一种示例中，处理器401可以包括一个或多个CPU，例如图4中的CPU0和CPU1。
作为一种可选的实现方式，通信装置400包括多个处理器，例如，除图4中的处理器401之外，还可以包括处理器407。
作为一种可选的实现方式，通信装置400还包括输出设备405和输入设备406。示例性地，输入设备406是键盘、鼠标、麦克风或操作杆等设备，输出设备405是显示屏、扬声器(speaker)等设备。
需要说明的是，通信装置400可以是台式机、便携式电脑、网络服务器、移动手机、平板电脑、无线终端、嵌入式设备、芯片系统或有图4中类似结构的设备。此外，图4中示出的组成结构并不构成对该通信装置的限定，除图4所示部件之外，该通信装置可以包括比图示更多或更少的部件，或者组合某些部件，或者不同的部件布置。
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。
此外，本申请的各实施例之间涉及的动作，术语等均可以相互参考，不予限制。本申请的实施例中各个设备之间交互的消息名称或消息中的参数名称等只是一个示例，具体实现中也可以采用其他的名称，不予限制。
下面以图3a所示架构为例，对本申请实施例提供的数据传输方法进行描述。下述实施例中的各网元可以具备图4所示部件，不予赘述。需要说明的是，本申请的实施例中各个设备之间交互的消息名称或消息中的参数名称等只是一个示例，具体实现中也可以采用其他的名称。例如本申请实施例所述的多播可以替换为广播(broadcast)、组播(multicast)、多播/广播等术语。本申请实施例中的确定也可以理解为创建(create)或者生成(generate)，本申请实施例中的“包括”也可以理解为“携带”等，本申请实施例对此不作具体限定。
图5为本申请实施例提供的一种数据传输方法，如图5所示，该方法可以包括：
步骤501：在第一多播业务对应的多播群组中存在至少一个处于预设状态的终端情况下，会话管理网元向用户面网元发送第一信息。
其中，上述会话管理网元可以为管理第一多播业务对应的多播会话的会话管理网元，如多播会话管理网元，上述会话管理网元也可以为管理终端的PDU会话(如单播会话)的会话管理网元，如单播会话管理网元。用户面网元可以是第一多播业务的锚点，用户面网元也可以不是第一多播业务的锚点，用户面网元可以为用于连通接入网设备与第一多播业务的锚点之间的用户面网元，如可以为PDU会话对应的用户面网元，即为单播业务的锚点，用户面网元与接入网设备之间建立通信连接，用户面网元与第一多播业务的锚点之间建立通信连接。
其中，第一多播业务对应的多播群组中存在至少一个处于预设状态的终端还可以替换描述为第一多播业务对应的多播群组中存在至少一个成员对应的终端处于预设状态，成员可以指使用终端的用户，即终端的使用者。第一多播业务可以指面向多个终端的业务，如第一多播业务可以为电视节目、文件传输服务、组内语音或视频通信、车队内部的广播业务等。第一多播业务所面向的多个终端可以加入一个群组，该群组可以称为第一多播业务对应的多播群组，多播群组中的所有终端可以被授权或者无需得到授权即可接收此多播业务的数据。即第一多播业务对应的多播群组可以为接收第一多播业务的数据的多个终端的组合，如多播群组可以为接收同一指挥中心发出的命令的车队或者为接收同一电视节目的用户群组等。
示例性的，在步骤501之前，多个终端可以参照图1a或图1b所示方式加入多播群组，多个终端共享同一用户面网元，如多个终端中每个终端可以建立自己的PDU会话，会话管理网元可以从多个终端建立的PDU会话中选择出一个PDU会话或者建立多播群组的专用信道，将第一多播业务的数据映射到选择出的PDU会话或多播群组的专用信道对应的QF，并在本地存储多播群组的上下文信息，多播群组的上下文信息可以包括加入多播群组的多个终端的标识信息、用户面网元的标识信息与第一多播业务之间的对应关系，将该QF与第一多播业务之间的映射关系对应配置给用户面网元，以便用户面网元接收到第一多播业务的数据后，通过该QF向多个终端发送第一多播业务的数据。终端建立PDU会话以及加入多播群组的详细过程可参照现有技术，不予赘述。
其中，预设状态、空闲态、非激活态的相关描述如上所述，不予赘述。会话管理网元可以通过下述示例一或者示例二确定第一多播业务对应的多播群组中存在至少一个处于预设状态的终端。下面以第一终端处于预设状态为例，对示例一、示例二两种 方式进行描述：
示例一，移动性管理网元确定第一终端与接入网设备之间断开RRC连接，无法向第一终端传输数据，移动性管理网元向会话管理网元发送用于去激活第一终端的用户面传输资源的第四信息，第四信息可以携带有第一终端的PDU会话的标识信息，如可以携带有第一终端的PDU会话的ID。会话管理网元接收第四信息，根据第四信息确定该移动性管理网元服务的第一终端处于预设状态。
其中，第四信息可以命名为去激活(deactivate)指示或者其他名字，不予限制。示例性的，移动性管理网元可以将第四信息携带在Nsmf_PDU会话更新会话管理上下文请求(Nsmf_PDU session_update SMContext request)中发送给会话管理网元。
其中，在会话管理网元为多播会话管理网元的情况下，移动性管理网元向会话管理网元发送第四信息可以包括：移动性管理网元向第一网元发送用于指示第一多播业务对应的多播群组的信息(如多播群组的识别信息)以及第四信息，第一网元接收用于指示第一多播业务对应的多播群组的信息以及第四信息，向管理该多播群组对应的多播会话的会话管理网元发送携带第四信息的订阅消息。其中，第一网元为第一终端对应的单播会话管理网元或者其他用于转发第四信息的中间网元，不予限制。
进一步的，会话管理网元确定第一终端处于预设状态后，可以以终端为粒度，将处于预设状态的终端记录到第一多播业务对应的多播群组的上下文中，如：会话管理网元可以将第一多播业务对应的多播群组的上下文中终端的标识信息对应设置一标志信息，该标志信息用于标识该终端的标识信息所标识的终端处于预设状态。
示例二，移动性管理网元确定该移动性管理网元服务的第一终端与接入网设备之间断开RRC连接，无法向第一终端传输数据，向会话管理网元发送用于指示第一多播业务对应的多播群组中存在至少一个由该移动性管理网元服务，且处于预设状态的终端的事件开放通知消息(Namf_EventExposure Notify)，会话管理网元接收事件开放通知消息，根据事件开放通知消息确定第一多播业务对应的多播群组中存在至少一个预设状态的终端。
其中，在会话管理网元为多播会话管理网元的情况下，移动性管理网元向会话管理网元发送事件开放通知消息可以包括：移动性管理网元向第一网元发送用于指示第一多播业务对应的多播群组的信息(如多播群组的识别信息)以及事件开放通知消息，第一网元接收用于指示第一多播业务对应的多播群组的信息以及事件开放通知消息，向管理该多播群组对应的多播会话的会话管理网元发送事件开放通知消息。其中，第一网元为第一终端对应的单播会话管理网元或者其他用于转发事件开放通知消息的中间网元，不予限制。
值得说明的是，第一网元在接收移动性管理网元发送的事件开放通知消息或者第四信息后，第一网元可以向会话管理网元发送其他类型的消息，例如请求消息或者订阅消息等，其他类型的消息所指示的内容与事件开放通知消息或者第四信息所指示的内容相同，本申请实施例对此不做限定。
进一步，会话管理网元接收到事件通知消息，确定第一多播业务对应的多播群组中存在至少一个处于预设状态的终端之后，会话管理网元可以以多播群组为粒度记录该多播群组中存在至少一个处于预设状态的终端，如：会话管理网元将第一多播业务 对应的多播群组的上下文对应设置一标志信息，该标志信息用于标识多播群组包括处于预设状态的终端。这种情况下，会话管理网元无需清楚具体处于预设状态的终端。
进一步的，会话管理网元可以本地存储移动性管理网元的标识信息以及第一多播业务的识别信息的之间的对应关系，以指示第一多播业务对应的多播群组中处于预设状态的终端由该移动性管理网元服务。如果会话管理网元通过第一网元接收事件通知消息，则会话管理网元还可以将第一网元的标识信息与第一多播业务的识别信息存储在本地，第一网元可以存储移动性管理网元的标识信息以及第一多播业务的识别信息的之间的对应关系存储在本地。
其中，移动性管理网元可以通过下述方式确定第一终端与接入网设备之间断开RRC连接：接入网设备或者移动性管理网元触发执行上述图2所示的AN release流程，使第一终端断开与接入网设备的RRC连接，处于RRC_idle态或者RRC_inactive态后，接入网设备向移动性管理网元发送携带第一终端的标识信息的UE上下文释放完成消息，移动性管理网元接收到UE上下文释放完成消息后，确定第一终端与接入网设备之间断开RRC连接。或者，在接入网设备确定第一终端已经断开与接入网设备的RRC连接，处于RRC_idle态或者RRC_inactive态时，或者接入网设备确定要将第一终端的上下文释放，或将第一终端的RRC连接释放时，接入网设备向移动性管理网元发送UE上下文释放请求消息或者UE通知消息(UE notification message)。移动性管理网元接收到此UE上下文释放请求消息或UE通知消息后，确定第一终端与接入网设备之间断开RRC连接。
其中，第一信息可以包括第一识别信息。第一信息可以用于在第一多播业务的数据到达用户面网元时向会话管理网元发送通知信息，还可以用于指示用户面网元缓存或者放弃第一多播业务的数据。示例性的，会话管理网元可以在首次接收到去激活第一多播业务对应的多播群组中的终端的用户面传输资源的信息或者首次接收到移动性管理网元发送的事件开放通知消息后，从多播群组的上下文中获取用户面网元的标识信息，根据用户面网元的标识信息，向用户面网元发送第一信息。
本申请实施例中，会话管理网元向用户面网元发送第一信息可以理解为：第一多播业务的数据到达用户面网元为一种事件(event)，会话管理网元为用户面网元发送满足该事件对应的配置(configuration)或指示(instruction)或处理规则(rule)，以便用户面网元根据会话管理网元下发的配置或者指示或者处理规则，触发用户面网元对该事件的报告(report)或者通知(notification)。或者，会话管理网元向用户面网元发送第一信息可以理解会话管理网元订阅用户面网元提供的服务，如会话管理网元向用户面网元发送订阅(subscribe)第一多播业务的数据到达用户面网元这件事的订阅信息，订阅信息中包含服务类型(或者触发条件)，当服务类型(或者触发条件)满足时。用户面网元会向会话管理网元发送通知(notification)信息。
具体的，会话管理网元向用户面网元发送第一信息可以包括：会话管理网元向用户面网元发送包含第一多播业务的数据到达用户面网元时用户面网元的处理规则或指示或者配置或订阅信息的用户面连接建立请求消息(如分组转发控制协议(packet forwarding control protocol，PFCP)会话建立请求(PFCP Session Establishment Request)，或用户面连接建立修改消息(如PFCP Session Modification Request)，或者是N4会 话建立请求(N4 Session Establishment Request)或者是N4会话修改请求(N4 Session Modification Request)，消息中。用户面网元根据第一多播业务的数据到达用户面网元时用户面网元的处理规则或指示或者配置或订阅信息，向会话管理网元发送报告或通知，如发送携带通知信息的用户面连接报告请求(如PFCP Session Report Request)或者N4会话报告请求(N4 Session Report Request)，或者下行数据通知(Downlink Data Notification)。
其中，第一识别信息可以用于识别第一多播业务的数据，第一识别信息可以替换描述为第一多播业务的识别信息。本申请各实施例中，第一识别信息或者第一多播业务的识别信息可以包括第一多播业务对应的多播群组的临时移动组标识(temporary mobile group identifier，TMGI)，或者应用服务器(如：提供第一多播业务的数据的AF)的因特网协议(internet protocol，IP)地址，或者第一多播业务的业务标识(service identifier，service ID)，或者第一多播业务的数据的分组过滤(packet filter)信息，或者第一多播业务的数据的数据流(service data flow，SDF)识别规则中一个或多个。
步骤502：用户面网元接收第一信息，接收第一多播业务的数据。
示例性的，用户面网元为第一多播业务的锚点，如果会话管理网元为管理第一多播业务对应的多播会话的多播会话管理网元，则用户面网元可以通过其与会话管理网元之间的N4链路直接接收来自会话管理网元的第一信息；会话管理网元为管理单播会话的会话管理网元，则用户面网元可以通过管理多播会话的多播会话管理网元接收来自会话管理网元的第一信息。用户面网元可以接收来自应用服务器的第一多播业务的数据。
示例性的，用户面网元不是第一多播业务的锚点，如果会话管理网元为管理第一多播业务对应的多播会话的多播会话管理网元，则用户面网元可以接收该用户面网元对应的单播会话管理网元的第一信息，第一信息由上述会话管理网元(即多播会话管理网元)转发给单播会话管理网元，如果会话管理网元为管理单播会话的会话管理网元，则用户面网元可以直接接收该会话管理网元的第一信息。用户面网元可以接收来自第一多播业务的锚点的第一多播业务的数据。
步骤503：用户面网元根据第一信息向会话管理网元发送通知信息。相应的，会话管理网元接收通知信息。
其中，通知信息可以用于表征第一多播业务的数据到达用户面网元。该通知信息可以包括用于识别第一多播业务的数据，如第一多播业务对应的多播群组的TMGI，或者应用服务器的IP地址，或者第一多播业务的业务标识，或者第一多播业务的数据的packet filter信息或者第一多播业务的数据的识别规则中的一种或多种。
示例性的，用户面网元可以向会话管理网元发送N4响应消息，N4响应消息中可以携带有通知信息。或者，用户面网元可以向会话管理网元发送通知信息，通知信息中可以携带有通知信息。
进一步的，如果第一信息还用于指示缓存第一多播业务的数据，则用户面网元根据第一信息中携带的第一识别信息确定缓存到达用户面网元的第一多播业务的数据，因此，当用户面网元接收到应用服务器发送的第一多播业务的数据时，不会将第一多播业务的数据映射到相应的QF上发送出去，而是将第一多播业务的数据保存在缓存 (buffer)中。
进一步的，如果第一信息未指示缓存第一多播业务的数据，而是指示丢弃第一多播业务的数据，则用户面网元接收到第一多播业务的数据后，停止发送第一多播业务的数据，丢弃(drop)接收到的第一多播业务的数据，或者，为了不影响其他处于连接态的终端接收第一多播业务的数据，用户面网元仍继续发送接收到的第一多播业务的数据。
步骤504：会话管理网元根据通知信息向移动性管理网元发送第二信息。
一种示例中，如果步骤501中，会话管理网元以终端为粒度，将处于预设状态的终端记录在第一多播业务对应的多播群组的上下文中，则会话管理网元接收到通知信息后，根据通知信息中携带的第一多播业务的识别信息，确定第一多播业务的数据已到达用户面网元，会话管理网元以第一多播业务的识别信息为索引，找到第一多播业务对应的多播群组的上下文，从多播群组的上下文中找到处于预设状态的终端，根据终端与移动性管理网元之间的对应关系向处于预设状态的终端对应的移动性管理网元分别发送触发建立终端与接入网设备之间的通信连接的信息。
其中，终端与移动性管理网元之间的对应关系可以包括终端的标识信息与移动性管理网元的ID之间的对应关系，该对应关系可以在终端建立PDU会话时保存在会话管理网元上。移动性管理网元的ID用于标识移动性管理网元，终端的标识信息如上所述，不予赘述。
其中，以至少一个处于预设状态的终端包括第一终端为例，会话管理网元可以向第一终端对应的移动性管理网元发送第二信息，如会话管理网元可以向第一终端对应的移动性管理网元发送N1N2消息传递(Namf_Communication_N1N2Message Transfer)，N1N2消息传递携带有第二信息。
其中，第二信息可以用于触发建立第一终端与第一接入网设备之间用于传输第一多播业务的数据的通信连接，第二信息可以包括第一终端的标识信息(如第一终端的PDU会话的识别信息)、以及N2接口会话管理(N2 session management，SM)信息。N2 SM信息可以成为空口资源配置信息，用于为第一终端分配第一多播业务对应的空口资源。N2 SM信息中可以包括第一多播业务的相关信息，第一多播业务的相关信息用于触发第一接入网设备为多播会话分配空口资源，重新将第一终端加入该第一多播业务对应的多播群组，如第一多播业务的相关信息可以包括第一多播业务的识别信息，还可以包括多播服务质量(quality of service，QoS)流的服务质量流标识(quality of identifier，QFI)，多播QoS流的QFI对应的QoS参数信息、多播QoS流对应的单播QoS流的信息、多播业务的QoS profile(s)、核心网侧用于发送上行数据的数据传输通道的信息(如核心网络N3隧道信息(CN N3 tunnel information)以及多播会话隧道的建立请求或指示等等，单播QoS流的信息可以包括单播QoS流的QFI与单播QoS流对应的QoS参数信息。QoS参数信息可以包括QFI、分配和抢占优先级信息(allocation and retention Priority，ARP)、最大传输比特率(maximum flow bit Rate，MFBR)、保障比特率信息(guaranteed flow bite rate、GFBR)中的一项或多项。可选地，第二信息可以包含第一多播业务对应的多播群组的TMGI。
又一种示例中，如果步骤501中，会话管理网元以多播群组为粒度记录该多播群 组中存在至少一个处于预设状态的终端，则会话管理网元接收到通知信息后，根据通知信息中携带的第一多播业务的识别信息，确定第一多播业务的数据已到达用户面网元，根据步骤501中移动性管理网元的标识信息以及第一多播业务的识别信息的之间的对应关系，向多播群组对应的移动性管理网元发送触发建立终端与接入网设备之间的通信连接的信息，该信息可以携带上述N2 SM信息。需要说明的是，该示例中，会话管理网元向多播群组对应的移动性管理网元发送触发建立终端与接入网设备之间的通信连接的信息中可以不携带具体某个终端的标识信息，可以携带多播群组的TMGI或者第一多播业务的识别信息等。
需要说明的是，会话管理网元向移动性管理网元发送第二信息，可以由会话管理网元直接向移动性管理网元发送第二信息，也可以通过第一网元或其他网元向移动性管理网元发送第二信息，本申请对此不做限定。
类似的，对于由其他移动性管理网元管理的、处于预设状态的终端，会话管理网元可以向其他移动性管理网元发送用于触发建立终端与接入网设备之间的通信连接的信息，直至向所有处于预设状态的终端对应的移动性管理网元发送用于触发建立终端与接入网设备之间的通信连接的信息，以使得处于预设状态的所有终端被移动性管理网元寻呼，并在从预设状态切换到RRC连接态的情况下，建立与接入网设备之间的通信连接。
本申请中，一个移动性管理网元可以管理多播群组中的一个或者多个终端，当移动性管理网元管理多个终端，且该多个终端都处于预设状态时，一种可能的设计中，会话管理网元可以向该移动性管理网元发送多个第二信息，多个第二信息与处于预设状态的多个终端一一对应，一个第二信息包括一个终端的标识信息，该第二信息用于触发建立该第二信息对应的终端与第一接入网设备之间的通信连接。又一种可能的设计中，为了降低信令开销，会话管理网元向该移动性管理网元发送一条第二信息，第二信息可以用于触发建立多个处于预设状态的终端与第一接入网设备之间的通信连接，第二信息可以包括多个终端的标识信息。应理解，第二信息多个终端的标识信息可以替换描述为第二信息包括UE list，UE list包括多个终端的标识信息等。
例如，假设移动性管理网元管理多播群组中的第一终端和第二终端，第一终端和第二终端都处于预设状态，则会话管理网元可以向该移动性管理网元发送两条独立的第二信息，一条第二信息用于触发建立第一终端与第一接入网设备之间的通信连接，另一条第二信息用于触发建立第二终端与第一接入网设备之间的通信连接。或者，为了降低信令开销，会话管理网元向移动性管理网元发送一条第二信息，第二信息用于触发建立第一终端与第一接入网设备之间的通信连接和第二终端与第一接入网设备之间的通信连接。
需要说明的是，会话管理网元可以同时或不同时地向不同移动性管理网元发送用于触发建立处于预设状态的终端与接入网设备之间的通信连接的信息。在移动性管理网元管理多个终端，且该多个终端都处于预设状态时，移动性管理网元同时或不同时地向移动性管理网元发送多条用于触发建立多个终端与接入网设备之间的通信连接的信息，不予限制。
例如，以多播群组中包括{UE1、UE2、UE3、UE4}，UE1、UE2、UE3处于预设 状态，UE1以及UE2由移动性管理网元1管理，UE3由移动性管理网元2管理为例，当会话管理网元接收到通知信息后，会话管理网元可以向移动性管理网元1发送信息1、向移动性管理网元2发送信息2，信息1包括UE1的标识信息以及UE2的标识信息，信息1用于触发建立UE1、UE2与接入网设备之间的通信连接，信息2包括UE3的标识信息，信息2用于触发建立UE3与接入网设备之间的通信连接。
步骤505：移动性管理网元接收来自会话管理网元的第二信息，根据第二信息向第一接入网设备发送第五信息。
其中，第一接入网设备可以为第一终端对应的接入网设备，第一接入网设备可以为第一终端提供网络服务。
其中，第五信息可以用于第一接入网设备建立第一接入网设备与第一终端之间的用于传输第一多播业务的数据的通信连接，如第五信息可以用于接入网设备为第一终端分配第一组播业务对应的空口资源。第五信息可以携带有以及上述第二信息携带的N2 SM信息，可选地，还可以携带有第一终端的标识信息或者第一多播业务的识别信息(如第一多播业务对应的多播群组的TMGI等)、安全配置信息，安全配置信息可以包括通过单播方式传输第一多播业务的数据时的安全配置信息、通过多播方式传输第一多播业务的数据时的安全配置信息中的一种或者多种。需要说明的是，因第一终端处于非激活态时，第一终端的空口资源被释放，第一终端的安全配置信息还保留，未被释放，所以第五信息可以包括N2 SM信息，不包括安全配置信息，而第一终端处于空闲态时，第一终端的空口资源以及第一终端的安全配置信息均被释放，则第五信息包括N2 SM信息以及安全配置信息。
示例性的，如果第二信息携带一个终端的标识信息，如第一终端的标识信息，移动性管理网接收到来自会话管理网元的第二信息后，以第二信息携带的第一终端的标识信息为索引，从终端的标识信息以及终端的状态之间的对应关系中查找第一终端的预设状态，当第一终端处于空闲态时，移动性管理网元根据第一终端的注册区域(registration area)获得寻呼区域，如将第一终端的注册区域作为寻呼区域。此后，移动性管理网元向该寻呼区域对应的第一接入网设备发送寻呼第一终端的寻呼(paging)消息。第一接入网设备接收并广播该寻呼消息，第一终端检测到该寻呼消息，在建立RRC连接后，将自身状态从空闲态切换到连接态，并通过第一接入网设备向移动性管理网元发送业务请求(service request)消息，移动性管理网元接收到第一终端发送的业务请求消息，响应于第一终端发送的业务请求消息，建立移动性管理网元与第一接入网设备之间的N2连接，从而使得终端的状态变为CM连接态，并向第一接入网设备发送N2请求(N2 request)，N2请求中携带第五信息。此时，第五信息中可以携带有上述N2 SM信息以及安全配置信息。当第一终端处于非激活态时，移动性管理网元向第一接入网设备发送N2请求，N2请求中携带第五信息，此时，第五信息携带上述N2 SM信息，而可以不需要携带安全配置信息。
需要说明的是，如果第二信息携带包括第一终端的标识信息在内的多个终端的标识信息，或者第二信息携带了第一多播业务对应的多播群组的TMGI，并且移动性管理网元存储了多播群组的TMGI和对应的终端的标识信息时，在此情况下，第二信息对应于多个终端。移动性管理网元可以接收到来自会话管理网元的第二信息后，以第 二信息携带的终端的标识信息为索引，从终端的标识信息以及终端的状态之间的对应关系中查找第二信息对应的多个终端的预设状态，或者，移动性管理网元以第二信息携带的TMGI为索引，查找TMGI对应的终端的标识信息，并且从终端的标识信息以及终端的状态之间的对应关系中查找第二信息对应的多个终端的预设状态。当第二信息对应的多个终端处于空闲态时，移动性管理网元针对第二信息对应的多个终端的注册区域(registration area)进行并集的计算(union of registration areas)，从而获得寻呼区域。
需要说明的是，本申请不限于第一终端将自身状态从空闲态切换到连接态的时间顺序，可以在第一终端接收到寻呼消息时，将第一终端的状态从空闲态切换到连接态，也可以在第一终端与接入网之间建立通信连接之后，将第一终端的状态从空闲态切换为连接态，此时该连接态可以指RRC连接态。
本申请中，移动性管理网元可以向第一接入网设备订阅多播群组中每个终端的状态，如移动性管理网元可以向第一接入网设备发送用于订阅终端的RRC状态的订阅请求，第一接入网设备接收该订阅请求，将终端的RRC状态携带在订阅响应中通知给移动性管理网元，移动性管理网元接收订阅响应，保存终端的标识信息以及终端的状态之间的对应关系，终端的RRC状态可以包括RRC状态、CM状态，CM状态包括CM连接态、CM空闲态，RRC状态可以包括idle态、非激活态等。
类似的，对于其他处于预设状态的终端，移动性管理网元可以参照上述过程，向其他处于预设状态的终端对应的接入网设备发送用于指示接入网设备建立与终端之间的通信连接的信息，如第二终端属于处于预设状态的终端，第二终端对应第二接入网设备，移动性管理网元根据第二信息，向第二接入网设备发送第六信息，第六信息用于第二接入网设备建立与第二终端之间的通信连接，直至向所有处于预设状态的终端对应的接入网设备发送用于指示接入网设备建立与处于预设状态的终端之间的通信连接的信息，以使得触发处于预设状态的所有终端建立与接入网设备之间的通信连接。
本申请中，同一接入网设备可以对应/服务一个或者多个处于预设状态的终端，若接入网设备对应/服务多个处于预设状态的终端，则移动性管理网元可以向该接入网设备发送多条信息，该多条信息与多个处于预设状态的终端一一对应，每条信息用于建立与该信息对应的终端与接入网设备之间的通信连接，或者，为了降低信令开销，移动性管理网元可以向该接入网设备发送一条信息，该条信息用于建立多个终端与接入网设备之间的通信连接。
例如，假设第一接入网设备对应第一终端和第二终端，第一终端和第二终端处于预设状态，则移动性管理网元可以向第一接入网设备发送两条独立的第五信息，一条第五信息用于建立第一终端与第一接入网设备之间的通信连接，另一条第五信息用于建立第二终端与第一接入网设备之间的通信连接；或者，为了降低信令开销，移动性管理网元向第一接入网设备发送一条第五信息，第五信息用于建立第一终端与第一接入网设备之间的通信连接、以及建立第二终端与第一接入网设备之间的通信连接。
步骤506：第一接入网设备接收第五信息，根据第五信息建立与第一终端之间的通信连接。
示例性的，第一接入网设备接收到第五信息后，根据第五信息携带的N2 SM为第 一终端分配第一多播业务对应的空口资源，如第一接入网设备根据N2 SM信息携带的单播QFI与单播QFI对应的QoS参数信息配置相应的用于通过单播方式传输第一多播业务的数据的数据无线承载(data radio bearer，DRB)、以及根据多播QFI对应的QoS参数信息配置相应的用于通过多播方式传输第一多播业务的数据的DRB，并通过RRC连接重配置或者RRC恢复过程将配置的DRB的相关信息发送给第一终端，以便第一终端可以在DRB上接收第一多播业务的数据。至此，建立与第一终端之间的通信连接。进一步的，如果第五信息中携带有安全配置信息，第一接入网设备将安全配置信息发送给第一终端。
其中，RRC连接重配置过程可以包括：第一终端处于空闲态，第一接入网设备与第一终端进行RRC连接重配置，向第一终端发送携带第一接入网设备配置的DRB的相关信息RRC重配置消息。RRC恢复过程可以包括：第一终端处于非激活态，第一接入网设备向第一终端发送寻呼消息，第一终端检测到该寻呼消息，将自身状态从非激活态切换到连接态，并向第一接入网设备发送RRC消息，如RRC恢复请求消息，第一接入网设备接收RRC恢复请求消息，向第一终端发送携带DRB的相关信息的RRC恢复消息。
本申请中，第一接入网设备可以通过第一信道向第一终端发送寻呼消息，第一信道可以为下述任一信道：第一接入网设备与第一终端之间的单播信道、公用信道、第一多播业务对应的多播群组的专用信道。
类似的，第一接入网设备可参照上述方法建立与其他终端之间的通信连接，不予赘述。
进一步的，步骤506之后，第一接入网设备向移动性管理网元发送第一指示信息，第一指示信息可以用于指示第一终端与第一接入网设备之间的通信连接建立完成，第一指示信息可以包括第一终端的标识信息。如果第一接入网设备与用户面网元之间的通信连接不存在，N2 SM信息还包括多播会话隧道的建立请求，则第一接入网设备还分配多播会话的隧道信息，如第一接入网设备的隧道信息，第一接入网设备的隧道信息用于建立传输第一多播业务的数据的隧道/通道。移动性管理网元接收的第一指示信息可以包括第一接入网设备的隧道信息、PDU会话的QoS流的QFI等，移动性管理网元向会话管理网元发送携带第一接入网设备的隧道信息、PDU会话的QoS流的QFI的PDU会话上下文更新请求。会话管理网元接收PDU会话上下文更新请求，与用户面网元进行N4会话更新，用户面网元根据第一接入网设备的隧道信息建立用户面网元与第一接入网设备之间的通信连接，之后，用户面网元向会话管理网元发送N4会话更新响应。
类似的，对于其他从预设状态切换到连接态的终端，第一接入网设备也可以向移动性管理网元用于指示该终端与第一接入网设备之间的通信连接建立完成的指示信息，如以第二终端为例，第一接入网设备向移动性管理网元发送第二指示信息，第二指示信息可以用于指示第二终端与第一接入网设备之间的通信连接建立完成，第二指示信息可以包括第二终端的标识信息。
需要说明的是，为了降低信令开销，在同一第一接入网设备对应/服务多个处于预设状态的终端的情况下，若该多个处于预设状态的终端都执行了步骤506所示过程， 建立了与第一接入网设备之间的通信连接，则该第一接入网设备可以向移动性管理网元发送一条指示信息，该条响应用于指示多个处于预设状态的终端都建立完与第一接入网设备之间的通信连接，该条响应中可以包括多个终端的标识信息。
进一步的，移动性管理网元接收第一指示信息后，根据第一指示信息向会话管理网元发送第二指示信息，第二指示信息可以携带有第一终端的标识信息，第二指示信息可以用于指示第一终端与第一接入网设备之间的通信连接建立完成。类似的，移动性管理网元接收来自第二接入网设备的第三指示信息，第三指示信息用于指示第二终端与第二接入网设备之间的通信连接建立完成，移动性管理网元根据第三指示信息，向会话管理网元发送第四指示信息，第二指示信息用于指示第二终端与第二接入网设备之间的通信连接建立完成。
或者，为了降低信令开销，移动性管理网元还可以在接收到多个接入网设备发送的用于指示通信连接建立完成的指示信息后，向会话管理网元发送一条指示信息，该条指示信息可以用于指示会话管理网元请求移动性管理网元触发建立的通信连接已全部建立完成。如移动性管理网元接收第一指示信息以及第二指示信息后，根据第一指示信息和第二指示信息向会话管理网元发送一条指示信息，该条指示信息包括第一终端的标识信息、第二终端的标识信息，该指示信息用于指示第一终端与第一接入网设备之间的通信连接和第二终端与第一接入网设备之间的通信连接都建立完成，或者，该指示信息用于指示会话管理网元请求移动性管理网元触发建立的通信连接已全部建立完成。
或者，移动性管理网元根据第二预设等待时长，向会话管理网元发送第五指示信息，第五指示信息用于指示移动性管理网元触发移动性管理网元建立的通信连接均建立完成。其中，移动性管理网元根据第二预设等待时长，向会话管理网元发送第五指示信息，向会话管理网元发送指示信息可以包括下述两种方式中任一方式：
方式一、第二预设等待时长可以根据需要设置，或者，如果移动性管理网元请求多个接入网设备建立，则为多个接入网设备的每个接入网设备配置一个预设时长，将其中最短的预设时长作为第二预设等待时长。
方式一中，移动性管理网元维护一个定时器，该定时器的时长为第二预设等待时长，在移动性管理网元请求第一个接入网设备建立通信连接之时或者之后的某个时刻启动该定时器，当该定时器运行第二预设等待时长，到期时，向会话管理网元发送第五指示信息。或者，在移动性管理网元请求最后一个接入网设备建立通信连接之时或者之后的某个时刻时启动该定时器，当该定时器运行第二预设等待时长，到期时，向会话管理网元发送第五指示信息。
方式二、如果移动性管理网元请求多个接入网设备建立，则为多个接入网设备的每个接入网设备设定一个定时器，该每个接入网设备的定时器时长为第二预设等待时长。对于每个接入网设备，在移动性管理网元开始请求接入网设备建立通信连接之时或之后启动该定时器，当所有接入网设备的定时器运行到期时，向会话管理网元发送第五指示信息。
进一步可选的，会话管理网元接收移动性管理网元发送的指示信息，如第二指示信息、或者第四指示信息或者第五指示信息，根据指示信息确定会话管理网元请求移 动性管理网元触发的通信连接完成。当会话管理网元接收移动性管理网元发送的指示信息，根据指示信息确定第一多播业务对应的多播群组中所有终端与接入网设备之间的通信连接都建立完成时，会话管理网元向用户面网元发送第三信息；或者，当会话管理网元接收移动性管理网元发送的指示信息，如第二指示信息、或者第四指示信息，根据指示信息确定至少一个处于预设状态的终端与接入网设备之间的通信连接都建立完成时，会话管理网元向用户面网元发送第三信息；或者，除依赖移动性管理网元发送的指示信息之后，会话管理网元还可以根据第一预设等待时长，向用户面网元发送第三信息。
其中，第三信息可以用于通知用户面网元发送第一多播业务的数据。第三信息可以包括第二识别信息，第二识别信息可以包括第一多播业务对应的多播群组的TMGI，或者应用服务器的IP地址，或者第一多播业务的业务标识，或者第一多播业务的数据的packet filter信息或者第一多播业务的数据的识别规则中的一种或多种。
其中，会话管理网元根据第一预设等待时长，向用户面网元发送第三信息可以包括下述二种方式中任一方式：
方式一、第一预设等待时长可以根据需要设置，或者，如果会话管理网元触发多个移动性管理网元建立通信连接，则为多个移动性管理网元的每个移动性管理网元配置一个预设时长，将其中最短的预设时长作为第一预设等待时长。
方式一中，会话管理网元维护一个定时器，该定时器的时长为第一预设等待时长，在会话管理网元触发第一个移动性管理网元建立通信连接之时或之后的某个时刻启动该定时器，当该定时器运行第一预设等待时长，到期时，向用户面网元发送第三信息。
方式二、会话管理网元针对发送给每个移动性管理网元的第一个第二信息设定一个定时器，该定时器时长为第一预设等待时长。对于每个移动性管理网元，在会话管理网元向该移动性管理网元发送第一个第二信息之后或者发送第一个第二信息时启动该定时器，当该定时器运行到期时，确定该移动性管理网元对应的所有终端与第一接入网设备之间的通信连接都建立完成，并在每个移动性管理网元对应的定时器均到期后，确定所有终端与第一接入网设备之间的通信连接都建立完成后，向用户面网元发送第三信息。
进一步的，用户面网元接收第三信息，根据第三信息发送缓存的第一多播业务的数据，如用户面网元可以将第一多播业务的数据映射到QF，通过QF发送给第一接入网设备，由第一接入网设备通过第一接入网设备与终端之间的通信连接发送给终端。或者，若步骤502替换为用户面网元接收到第一多播业务的数据后，根据第一信息丢弃接收到的第一多播业务的数据，则用户面网元接收第三信息，可以根据第三信息继续接收应用服务器重新发送的第一多播业务的数据，发送第一多播业务的数据。
基于图5所示方法，可以在多播业务对应的多播群组中存在至少一个处于预设状态的终端的情况下，触发会话管理网元通知多播业务对应的用户面网元接收到多播业务的数据后，先缓存多播业务的数据，再通过核心网设备触发寻呼终端，使终端处于连接态，并在多播群组中的所有终端与接入网设备之间建立通信连接的情况下，触发用户面网元通过接入网设备向多播群组中的终端发送接收到的或者缓存的多播业务的数据，保证多播群组中的终端接收到多播业务的数据。
需要说明的是，在本申请各实施例中，采用了“第一”、“第二”等字样对功能和作用基本相同的相同项或相似项进行区分。本领域技术人员可以理解“第一”、“第二”等字样并不对数量和执行次序进行限定，并且“第一”、“第二”等字样也并不限定一定不同。例如，本申请所述的第一多播业务可替换描述为多播业务。
下面结合图3b所示通信系统，以会话管理网元为SMF，用户面网元为UPF，接入网设备为RAN，多播群组中的终端共享同一UPF，多播群组包括UE1、UE2等多个UE为例，对图5所示方法进行详细描述。图6为本申请实施例提供的一种数据传输方法的流程图，如图6所示，该方法可以包括：
步骤601：UE1、UE2分别建立PDU会话，在UE1、UE2建立PDU会话之后，UE1、UE2还会进一步地通过PDU会话修改请求或通过用户面发送的用于加入多播业务对应的多播群组的加入请求，触发SMF参照图1a所示方式建立传输第一多播业务的数据的通道，选择UE1和UE2中任一UE的PDU会话所对应的QF作为用于传输第一多播业务的数据的QF，如选择UE2的PDU会话对应的QF作为用于传输第一多播业务的数据的QF，或者，SMF将UE1、UE2加入该的相关信息提供至RAN，触发RAN建立多播群组的专用信道，多播群组的专用信道中包含用于传输第一多播业务的数据的QF。
其中，UE1、UE2建立PDU会话的过程可参照现有技术，不予赘述。
进一步的，会话管理网元选择出用于传输第一多播业务的数据的QF后，SMF可以配置UPF保存RAN的下行隧道信息以及QFI之间的对应关系、QFI与多播业务的识别信息之间的对应关系等。进一步的，SMF中还保存多播群组的上下文，多播群组的上下文中包括多播群组中UE的标识信息、UPF的标识信息以及多播业务的标识信息之间的对应关系。
步骤602：UE1接收RAN发送的RRC释放消息，进入空闲态或者非激活态，触发AMF向SMF发送第四信息，指示去激活UE1的用户面传输资源。
其中，步骤602的执行过程可参照图2所示，不予赘述。
其中，UE2可以处于RRC连接态，UE2的用户面传输资源可以处于去激活状态或者激活状态，不予限制。
步骤603：SMF接收第四信息，向UPF发送第一信息。相应的，UPF接收第一信息。
其中，第一信息的相关描述可参照步骤501中所述，第一信息用于配置当第一多播业务的数据到达UPF时，UPF向SMF发送通知信息，并且进一步地，第一信息还可以包含用于指示UPF缓存第一多播业务的数据的指示信息。具体的，SMF向UPF发送第一信息的过程可参照图5中步骤501所述，不予限制。
步骤604：UPF接收并识别出AS发送的第一多播业务的数据。
步骤605：UPF根据步骤603接收到的第一信息缓存接收到的第一多播业务的数据。
可替换的，步骤605还可以为UPF根据步骤603接收到的第一信息发送接收到的第一多播业务的数据或者丢弃接收到第一多播业务的数据。
步骤606：UPF向SMF发送通知信息。
其中，通知信息的相关描述、UPF向SMF发送通知信息的过程可以参照图5对应的实施例中所述，不予赘述。
步骤607：SMF接收通知信息，根据通知信息找到UE1，向UE1对应的AMF发送携带第二信息的N1N2消息传递。相应的，AMF接收N1N2消息传递。
其中，第二信息的相关描述、SMF向UE1对应的AMF发送携带第二信息的N1N2消息传递的过程可参照图5对应的实施例中所述，不予赘述。
需要说明的是，若多播群组中存在多个处于预设状态的UE，且多个UE对应一个或者多个AMF，则SMF可以向一个或者多个AMF分别发送N11消息。其中，一个AMF对应一条N11消息，一条N11消息包括AMF对应的处于预设状态的所有UE的PDU会话的标识信息；或者，一个AMF对应多条N11消息，一条N11消息包括AMF的对应的处于预设状态的多个UE的PDU会话的标识信息，不予限制。
进一步的，若UE1处于空闲态，则执行步骤608～步骤615，流程结束；若UE1处于非激活态，则执行步骤610～步骤615，流程结束。
步骤608：AMF确定UE1处于空闲态，AMF通过RAN向UE1发送寻呼消息。
其中，寻呼消息可以用于寻呼UE1。寻呼消息可以包括UE1的标识信息等。
步骤609：UE1接收到寻呼消息，向AMF发送业务请求消息。相应的，AMF接收业务请求消息。
其中，业务请求消息可以用于请求网络侧建立UE的上下文，建立RAN与网络侧之间的CM连接。业务请求消息可以包括安全参数，UE的标识信息等。
步骤610：AMF向RAN发送第五信息。
其中，第五信息携带N2 SM信息，第五信息的相关描述可参照图5中所述，不予赘述。
步骤611：RAN接收第五信息，根据第五信息建立RAN与UE1之间的通信连接。
具体的，步骤611可参照步骤506所述，不予赘述。
步骤612：RAN向AMF发送第一指示信息，AMF接收第一指示信息，根据第一指示信息向SMF发送第二指示信息。
其中，第一指示信息、第二指示信息可以用于指示RAN与UE1间的通信连接建立完成。
类似的，若该AMF下的其他RAN与UE间的通信连接建立完成，则也可以参照步骤612所示过程向SMF发送指示信息。其中，指示信息可以用于指示AMF对应的、处于多播群组的UE与RAN之间的通信连接都建立完成。需要说明的是，当AMF接收到所有接收N2 SM信息的RAN返回的用于指示通信连接建立完成的指示信息后，向SMF发送用于指示SMF请求AMF触发的所有通信连接均建立完成的第五指示信息，或者，设置一定时器，该定时器的时长为上述第二预设等待时长，当定时器到期后，就向SMF发送用于指示SMF请求AMF触发的所有通信连接均建立完成的第五指示信息。
进一步的，如果RAN与UPF之间的传输隧道被释放，N2 SM信息还携带有多播会话隧道的建立请求或指示，则RAN还可以通过AMF向SMF发送RAN的下行隧道信息，以便SMF将RAN的下行隧道信息发送给UPF，UPF根据RAN的下行隧道信 息将第一多播业务的数据发送给RAN，由RAN发送给多播群组的UE。
步骤613：SMF接收第二指示信息，当多播群组中或者至少一个处于预设状态的所有UE与接入网设备之间的通信连接建立完成，或者，第一预设等待时长后，向UPF发送N4消息，N4消息携带有第三信息。
其中，第三信息可以用于指示UPF发送第一多播业务的数据。N4消息还可以包括第一多播业务的识别信息以及RAN的下行隧道信息等。
需要说明的是，当SMF接收到所有接收N1N2消息传递的AMF返回的指示信息后，向UPF发送N4消息，或者，设置一定时器，该定时器的时长为上述第一预设等待时长，当定时器到期后，就向UPF发送携带第三信息的N4消息，不予限制。
步骤614：UPF接收N4消息，根据N4消息发送缓存的第一多播业务的数据。
需要说明的是，步骤614是可选的。在步骤605中，如果SMF向UPF发送的第一信息中包含用于指示UPF缓存第一多播业务的数据的信息，步骤614才会执行。
步骤615：RAN接收第一多播业务的数据，发送第一多播业务的数据。
基于图6所示方法，通过SMF指示UPF将第一多播业务的数据进行缓存，使得当多播群组的某些UE处于非激活态，能够让UPF及时缓存第一多播业务的数据，当多播群组的所有UE处于连接态时，UPF才会发送第一多播业务的数据。这样可以保证所有UE都可以无丢失地接收到第一多播业务的数据。
上述图5或者图6所示方法，以在多播群组中存在处于预设状态的终端的情况下，由用户面网元在会话管理网元的指示下缓存第一多播业务的数据，并触发寻呼处于预设状态的终端，建立终端与接入网设备之间的通信连接，并在多播群组中存在处于预设状态的终端与接入网设备之间的通信连接建立完成时，再触发用户面网元发送缓存的第一多播业务的数据为例，对本申请实施例提供的数据传输方法进行了描述，可替换的，还可以由RAN接收并缓存第一多播业务的数据，寻呼处于预设状态的终端，并在多播群组中存在处于预设状态的终端切换到连接态，与接入网设备之间的通信连接建立完成时，再发送缓存第一多播业务的数据。该方法可以参照图7所示。
图7为本申请实施例提供的又一种数据传输方法的流程图，如图7所示，可以包括：
步骤701：用户面网元向第一接入网设备发送第一多播业务的数据，相应的，第一接入网设备接收第一多播业务的数据。
其中，第一多播业务的相关描述可参照步骤501中，不予赘述。
示例性的，第一接入网设备可以通过第一接入网设备与用户面网元之间的下行传输隧道，接收来自第一多播业务对应的用户面网元的第一多播业务的数据。
步骤702：当在第一多播业务对应的多播群组中存在至少一个由第一接入网设备服务，且处于预设状态的终端时，第一接入网设备缓存第一多播业务的数据。
示例性的，第一接入网设备可以通过图2所示RRC连接释放过程确定其服务的、且处于第一多播业务对应的多播群组的终端是否处于预设状态，如以第一终端为例，当第一接入网设备接收到来自第一终端的RRC释放消息后，根据第一终端发送的RRC释放消息确定第一终端处于预设状态：RRC_idle态或者RRC_inactive态。
步骤703：第一接入网设备向第一终端发送寻呼消息。相应的，第一终端接收寻 呼消息。
其中，所述寻呼消息可以用于寻呼第一终端，以使得第一终端从预设状态切换到RRC连接态，如从idle态切换到RRC连接态，或者，从非激活态切换到RRC连接态等。第一终端包括在上述至少一个处于预设状态的终端中，寻呼消息可以包括第一终端的标识信息，第一终端的标识信息如图5所示方法中所述，不予赘述。
示例性的，第一接入网设备可以通过以第一信道向第一终端发送寻呼消息，第一信道可以包括下述任一信道：第一接入网设备与第一终端之间的单播信道、公用信道、第一多播业务对应的多播群组的专用信道。
类似的，对于处于预设状态的其他终端，第一接入网设备也可以向其他终端发送寻呼消息，如上述至少一个处于预设状态的终端中还包括第二终端为例，第一接入网设备向第二终端发送用于寻呼第二终端的寻呼消息。以此类推，直至第一接入网设备寻呼至少一个处于预设状态的终端中的所有终端。需要说明的是，第一接入网设备可以同时寻呼至少一个处于预设状态的终端，也可以不同时寻呼至少一个处于预设状态的终端，不予限制。
进一步可选的，图7所示方法还可以包括：
步骤704：第一终端向第一接入网设备发送第一RRC消息。相应的，第一接入网设备接收来自第一终端的第一RRC消息。
其中，第一RRC消息可以用于请求建立第一终端与第一接入网设备之间的通信连接，通信连接可以用于传输第一多播业务的数据。当第一终端处于空闲态时，第一RRC消息为业务请求消息。当第一终端处于非激活态时，第一RRC消息可以为RRC恢复请求消息。
类似的，接收第一接入网设备发送的寻呼消息的终端都可以参照步骤704所述，向第一接入网设备发送第一RRC消息，请求第一接入网设备建立与其之间的通信连接。
步骤705：第一接入网设备根据第一RRC消息，从移动性管理网元获取第五信息。
其中，第五信息可以用于建立第一终端与第一接入网设备之间的通信连接。第五信息的相关描述可参照步骤505中所述，不予赘述。
示例性的，第五信息可以为N2 SM信息，第一接入网设备可以从移动性管理网元获取第五信息，移动性管理网元可以从会话管理网元获取第五信息。移动性管理网元从会话管理网元获取第五信息可以包括：移动性管理网元向会话管理网元发送用于去激活第一终端的用户面传输资源的第四信息，会话管理网元接收来自移动性管理网元的第四信息，以第四信息作为触发条件，响应于第四信息向移动性管理网元发送第五信息。或者，会话管理网元根据第四信息向移动性管理网元发送订阅请求，订阅请求用于请求订阅第一事件，第一事件为第一终端从预设状态转换到连接态；当会话管理网元接收到移动性管理网元通知的第一事件时，会话管理网元向移动性管理网元发送第五信息。
其中，第四信息的相关描述可参照图5所示方法中，不予赘述。
步骤706：第一接入网设备根据第五信息，向第一终端发送第七信息。
其中，第七信息用于指示第一终端与第一接入网设备之间的通信连接的相关配置，如为第一终端配置的用于传输第一多播业务的数据的空口资源/DRB等。
示例性的，第一接入网设备接收到第五信息后，根据第五信息携带的N2 SM为第一终端分配第一多播业务对应的空口资源，如第一接入网设备根据N2 SM信息携带的单播QFI与单播QFI对应的QoS参数信息配置相应的用于通过单播方式传输第一多播业务的数据的DRB、以及根据多播QFI对应的QoS参数信息配置相应的用于通过多播方式传输第一多播业务的数据的DRB，并通过RRC连接重配置或者RRC恢复过程将配置的DRB的相关信息发送给第一终端，以便第一终端可以在DRB上接收第一多播业务的数据。进一步的，如果第五信息中携带有安全配置信息，第一接入网设备将安全配置信息发送给第一终端。
至此，第一接入网设备与第一终端之间的通信连接建立完成。
类似的，可参照上述过程将其他终端切换到连接态，建立其他处于预设状态的终端与第一接入网设备之间的通信连接，不予赘述。
进一步的，当在第一多播业务对应的多播群组中不存在由第一接入网设备服务，且处于预设状态的终端时，第一接入网设备发送已缓存的第一多播业务的数据。或者，
第一接入网设备根据第三预设等待时长，发送已缓存的第一多播业务的数据，如设置一定时器，该定时器的时长等于第三预设等待时长，第一接入网设备开始寻呼终端时启动该定时器，该定时器运行结束，发送已缓存的第一多播业务的数据，而是需要等待定时器到期之后才发送缓存的第一多播业务的数据，尽可能地会减少多播群组内终端的丢包问题。
例如，假设第一接入网设备下存在多播群组1，这个多播群组内有10个终端，3个在连接态，7个在空闲态，因为这7个在空闲态的终端从空闲态回到连接态的速度不一样。并且还有3个在连接态的终端不需要先执行寻呼，也即他们已经在连接态，所以一旦立即给某个在连接态的终端分配空口资源，发送缓存的第一多播业务的数据，则万一此时其它终端回到连接态的速度较慢，还处于回到连接态、建立通信连接的流程中，会导致其它终端针对该第一多播业务的数据的丢包问题，影响多播群组中其它终端的业务体验，而在第一接入网设备设置定时器，直到定时器到期后，才发送缓存的第一多播业务的数据的目的是让多播群组内的大部分终端在定时器这段时间内尽可能多的回到连接态、建立通信连接，尽可能地会减少多播群组内终端的丢包问题。
基于图7所示方法，可以在第一多播业务对应的多播群组中存在至少一个由第一接入网设备服务，且处于预设状态的终端的情况下，触发第一接入网设备接收到多播业务的数据后，先缓存多播业务的数据，再寻呼终端，使终端处于连接态，并在多播群组中的所有终端与第一接入网设备之间建立通信连接的情况下，发送缓存的多播业务的数据，保证多播群组中的终端接收到多播业务的数据。
下面结合图3b所示通信系统，以会话管理网元为SMF，移动性管理网元为AMF，用户面网元为UPF，第一接入网设备为RAN，多播群组中的终端共享同一UPF，RAN对应的/服务的UE1以及UE2处于第一多播业务对应的多播群组为例，对图7所示方法进行详细描述。图8a为本申请实施例提供的又一种数据传输方法的流程图，如图8a所示，可以包括：
步骤801：UE1、UE2分别建立PDU会话，在UE1、UE2建立PDU会话之后，UE1、UE2还会进一步地通过PDU会话修改请求或通过用户面发送的用于加入多播业 务对应的多播群组的加入请求，触发SMF参照图1a所示方式建立传输第一多播业务的数据的通道，选择UE1和UE2中任一UE的PDU会话所对应的QF作为用于传输第一多播业务的数据的QF，如选择UE2的PDU会话对应的QF作为用于传输第一多播业务的数据的QF。
其中，步骤801可参照步骤601所述，不予赘述。
步骤802：UE1接收RAN发送的RRC释放消息，进入空闲态或者非激活态，触发AMF向SMF发送第四信息，指示去激活UE1的用户面传输资源。
其中，步骤802可参照步骤602所述，不予赘述。
进一步的，SMF接收到第四信息之后，可以响应于第四信息向AMF发送第五信息，AMF接收并保存第五信息；或者，SMF向AMF订阅第一事件，所述第一事件为UE1从预设状态转换到连接态。
其中，第四信息、第二信息的相关描述可参照图5对应的实施例中所述，不予赘述。
步骤803：UPF接收并识别出AS发送的第一多播业务的数据。
步骤804：UPF向RAN发送第一多播业务的数据。
步骤805：RAN接收第一多播业务的数据，缓存第一多播业务的数据。
示例性的，RAN可以根据步骤802获知多播群组中存在处于预设状态的UE1，缓存第一多播业务的数据。
步骤806：RAN向UE1发送寻呼消息。
步骤807：UE1接收寻呼消息，向RAN发送第一RRC消息。
其中，第一RRC消息可以为业务请求消息或者RRC恢复请求消息。
步骤808：RAN接收第一RRC消息，从AMF获取第五信息。
具体的，第五信息的相关描述可参照图5对应的实施例中所述，不予赘述。
一种示例中，第五信息可以由步骤802中UE1进入预设状态，即SMF接收到AMF发送的第四信息时，触发SMF提前将第五信息发送给AMF，由AMF存储起来，当RAN接收第一RRC消息后，触发RAN从AMF获取第五信息。
又一种示例中，RAN接收第一RRC消息后，通过AMF将第一事件通知给SMF，触发SMF通过AMF将第五信息发送给RAN，以便RAN根据第五信息确定第五信息。
步骤809：RAN根据第五信息，向UE1发送第七信息。
其中，第七信息用于指示第一终端与第一接入网设备之间的通信连接的相关配置，如为第一终端配置的用于传输第一多播业务的数据的空口资源/DRB等。
其中，步骤809可参照步骤506所述，不予赘述。
步骤810：RAN确定在第一多播业务对应的多播群组中不存在由RAN服务，且处于预设状态的UE，RAN通过RAN与多播群组中的UE之间的通信连接，向多播群组中的UE发送第一多播业务的数据。
基于图8a所示方法，当在第一多播业务对应的多播群组中不存在由RAN服务，且处于预设状态的UE，RAN及时缓存第一多播业务的数据，当多播群组的所有不存在由RAN服务，且处于预设状态的UE时，RAN发送第一多播业务的数据。这样可以保证所有态下的UE都可以无丢失地接收到第一多播业务的数据。
应理解，为降低信令开销，会话管理网元在接收到用户面网元的接收到第一多播业务的数据的通知信息后，可以通过一条信令消息将加入多播群组的终端指示给移动性管理网元，以便移动性管理网元将处于空闲态的终端寻呼起来接收第一多播业务的数据。具体的，该方法可以参照图8b所示：
图8b为本申请实施例提供的又一种数据传输方法，如图8b所示，可以包括：
S8b1:会话管理网元向移动性网元发送多播群组的UE list。相应的，移动性管理网元接收多播群组的UE list。
其中，会话管理网元可以为图3b中的SMF，会话管理网元可以管理终端的PDU会话，该PDU会话与多播群组对应的多播会话关联。移动性管理网元可以是图3b中的AMF，加入多播群组的终端可以通过移动性管理网元进行网络注册。
其中，UE list可以用于指示/对应加入多播群组的终端。应理解，此处所述的加入多播群组的终端可以包括加入多播群组的全部终端，也可以包括加入多播群组的终端中的部分终端，比如可以包括加入多播群组且处于预设状态的终端，或者包括会话管理网元所管理的终端中满足下述条件的终端：加入多播群组、加入多播群组且处于预设状态、或者加入多播群组且未建立用于传输第一多播业务的数据的通信连接等。
具体的，UE list可以包括多个加入多播群组的终端的标识信息。需要说明的是，UE list包括的多个加入多播群组的终端的标识信息，可以不是网络中所有加入多播群组的终端的标识信息，而是那些向会话管理网元发送多播群组加入请求的终端的标识信息，或者说，UE list可以对应那些由会话管理网元存储的加入多播群组的终端的标识信息。比如UE list可以包括第一终端的标识信息和第二终端的标识信息等。UE list可以携带在第二信息中，第二信息可以用于触发建立加入多播群组的终端与接入网设备之间的通信连接，通信连接用于传输第一多播业务的数据。第二信息还可以携带多播群组的标识信息。具体的，第二信息的相关描述可以参照步骤504中所述。
示例性的，会话管理网元可以接收来自用户面网元的用于通知接收到第一多播业务的数据的通知信息，根据通知信息向移动性网元发送携带多播群组的UE list的第二信息。具体的，会话管理网元发送第二信息的实现过程可参照步骤501-步骤504所述。
S8b2：移动性管理网元确定UE list指示的终端中处于空闲态的终端，向处于空闲态的终端发送寻呼消息。
S8b2中，为了保证终端可以通过通信连接正常接收到第一多播业务的数据，对应处于空闲态(或者称为CM-IDLE态)的终端还需要转换为连接态(或者称为CM-CONNECTED)。本申请中可以通过组寻呼方式寻呼处于空闲态的终端。具体的，组寻呼方式可以包括：移动性管理网元确定UE list指示的终端中处于空闲态的终端，获取处于空闲态的终端的注册区域，根据处于空闲态的终端的注册区域计算得到第一寻呼区域，在第一寻呼区域发送携带多播群组的标识信息的寻呼消息。
其中，处于空闲态的终端可以是一个或者多个。移动性管理网元确定UE list指示的终端中处于空闲态的终端可以包括：移动性管理网元可以以终端的标识信息为索引，查到移动性管理网元保存的终端的上下文，如果找到的终端的上下文中终端的状态信息指示终端处于空闲态(比如终端的上下文中含有空闲态无线网络临时标识(idle radio network temporary identifier，I-RNTI)，或者终端的上下文中不存在AMF UE下一代 应用协议标识(AMF UE Next Generation Application Protocol ID，AMF UE NGAP ID)，则确定该终端处于空闲态。
本申请实施例中，寻呼消息可以用于寻呼处于空闲态的终端。组寻呼方式中，寻呼消息可以携带多播群组的标识信息，需要接收第一多播业务的数据的终端在寻呼信道监听到携带多播群组的标识信息的寻呼消息后，终端可以从空闲态转变为(transition to)连接态。
比如，处于空闲态的终端包括第一终端和第二终端，移动性管理网元可以在第一寻呼区域发送携带多播群组的标识信息的寻呼消息。进一步的，如果第一终端被成功寻呼，则移动性管理网元接收来自第一终端的业务请求消息；和/或如果第二终端被成功寻呼，移动性管理网元接收来自第二终端的业务请求消息。
本申请实施例中，每个终端的注册区域可以由移动性管理网元配置，并预先分配给终端。每个终端的注册区域可以包括一个或者多个小区，终端的注册区域可以包括一个或者多个接入网设备的信区域覆盖区域。比如UE1的注册区域可以包含1区域、2区域、以及3区域基站的信区域覆盖区域。
其中第一寻呼区域包括第一终端的注册区域和第二终端的注册区域，即包括第一终端的注册区域和第二终端的注册区域的并集/全集。可选的，为了使更多的终端可以接收到第一多播业务的数据，则第一寻呼区域还包括UE list中除第一终端以及第二终端之外的终端的注册区域。或者，第一寻呼区域还包括UE list中除第一终端以及第二终端之外的处于空闲态的终端的注册区域，如此可以在更多的终端的注册区域发起组寻呼，便于更多的终端被呼起接收第一多播业务的数据。
例如，UE list包括UE1-UE3，在空闲态的UE1、UE2会被预先分配一个注册区域，例如，UE1的注册区域包含1区域、2区域、以及3区域，UE2的注册区域包含2区域、3区域以及4区域。假设以多个UE为粒度进行组寻呼，由于UE1的注册区域中2区域、3区域与UE2的注册区域中2区域、3区域是重叠的，而UE1的注册区域中1区域与UE2的注册区域不存在重叠区域，UE2的注册区域中4区域与UE1的注册区域不存在重叠区域，则在一个寻呼周期，可以在1区域、2区域、3区域、4区域发送携带多播群组的标识信息(例如MBS session ID)的寻呼消息，与per UE为粒度的寻呼相比节省了寻呼信令开销。或者，在1区域、2区域、3区域、4区域以及UE3的注册区域中发送携带多播群组的标识信息(例如MBS session ID)的寻呼消息，使更多的终端可以被寻呼到，接收第一多播业务的数据。
进一步可选的，对于未建立与接入网设备之间的用于传输第一多播业务的数据的通信连接的终端，为了保证第一多播业务的数据的正常传输，所述方法还包括：
S8b3:移动性管理网元向这些终端对应的接入网设备发送用于接入网设备建立与加入多播群组的终端之间的通信连接的信息。
其中，接入网设备可以包括未建立用于传输第一多播业务的数据的通信连接的一个或者多个接入网设备。移动性管理网元向接入网设备发送用于接入网设备建立与加入多播群组的终端之间的通信连接的信息可以包括：移动性管理网元向一个或者多个接入网设备分别发送用于建立与终端之间的通信连接的信息。
比如第一终端和第二终端未与接入网设备之间建立用于传输第一多播业务的数据 的通信连接的，第一终端对应第一接入网设备，第二终端对应第二接入网设备，则移动性管理网元可以向第一接入网设备分别发送用于第一接入网设备建立与第一终端之间的通信连接的第五信息，向第二接入网设备分别发送用于第二接入网设备建立与第二终端之间的通信连接的第六信息。具体的，第五信息、第六信息的相关描述以及发送方式可以参照步骤505中所述，不予赘述。
应理解，本申请不限制移动性管理网元向终端对应的接入网设备分别发送用于接入网设备建立与加入多播群组的终端之间的通信连接的信息的时间先后顺序。比如上文所述的第五信息、第六信息可以先后发送，也可以同时发送，不予限制。
S8b4:接入网设备根据用于接入网设备建立与加入多播群组的终端之间的通信连接的信息，建立与终端之间的通信连接。
具体的，S8b4可以参照步骤506中第一接入网设备建立与第一终端之间的通信连接的过程，不予赘述。
基于图8b所示方法，可以通过一条信令消息触发在多个终端的注册区域进行组寻呼，降低寻呼信令开销，同时，建立多个终端与接入网设备之间的用于接收多播业务的数据的通信连接，降低信令开销。
上述主要从各个节点之间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，各个节点，如会话管理网元、移动性管理网元、用户面网元、第一接入网设备等为了实现上述功能，其包含了执行各个功能相应的硬件结构和/或软件模块。本领域技术人员应该很容易意识到，结合本文中所公开的实施例描述的各示例的算法步骤，本申请能够以硬件或硬件和计算机软件的结合形式来实现。某个功能究竟以硬件还是计算机软件驱动硬件的方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用使用不同方法来实现所描述的功能，但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会话管理网元、移动性管理网元、用户面网元、第一接入网设备等进行功能模块的划分，例如，可以对应各个功能划分各个功能模块，也可以将两个或两个以上的功能集成在一个处理模块中。上述集成的模块既可以采用硬件的形式实现，也可以采用软件功能模块的形式实现。需要说明的是，本申请实施例中对模块的划分是示意性的，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式。
图9为本申请实施例提供的一种通信装置90的组成示意图，该通信装置90可以为会话管理网元或者会话管理网元中的芯片或者片上系统。一种可能的设计中，如图9所示，该通信装置90可以包括：发送单元901，接收单元902；
发送单元901，用于在第一多播业务对应的多播群组中存在至少一个处于预设状态的终端的情况下，向用户面网元发送用于用户面网元在第一多播业务的数据到达用户面网元时向会话管理网元发送通知信息的第一信息。例如，发送单元901可以用于支持通信装置90执行步骤501以及步骤603。
接收单元902，用于接收来自用户面网元的用于表征第一多播业务的数据到达用户面网元的通知信息。例如，接收单元902用于支持通信装置90执行步骤504以及步骤607。
发送单元901，还用于根据通知信息，向移动性管理网元发送用于触发建立第一终端与第一接入网设备之间的通信连接的第二信息，第一终端属于至少一个处于预设状态的终端。例如，发送单元901用于支持通信装置90执行步骤504以及步骤607。
具体的，该可能的设计中，上述图5～图6所示方法实施例中涉及会话管理网元的各步骤的所有相关内容均可以援引到对应功能模块的功能描述，在此不再赘述。该可能的设计中所述的通信装置90用于执行图5～图6所示数据传输方法中会话管理网元的功能，因此可以达到与上述数据传输方法相同的效果。
需要说明的是，作为再一种可实现方式，图9所示通信装置90可以包括：处理模块和通信模块。通信模块可以集成发送单元901、接收单元902的功能。处理模块用于对通信装置90的动作进行控制管理，例如，处理模块用于支持该通信装置90执行本文所描述的技术的其它过程。通信模块用于支持通信装置90执行步骤501、步骤504以及步骤607等以及与其他网络实体的通信。进一步的，图9所示通信装置90还可以包括存储模块，用于存储通信装置90的程序代码和数据。
其中，处理模块可以是处理器或控制器。其可以实现或执行结合本申请公开内容所描述的各种示例性的逻辑方框，模块和电路。处理器也可以是实现计算功能的组合，例如包含一个或多个微处理器组合，DSP和微处理器的组合等等。通信模块可以是收发电路或通信接口等。存储模块可以是存储器。当处理模块为处理器，通信模块为通信接口，存储模块为存储器时，图9所示通信装置90可以为图4所示通信装置400。
图10为本申请实施例提供的一种通信装置100的组成示意图，该通信装置100可以为用户面网元或者用户面网元中的芯片或者片上系统。如图10所示，该通信装置100可以包括：接收单元1001、发送单元1002；
接收单元1001，用于接收来自会话管理网元的用于用户面网元在第一多播业务的数据到达用户面网元时向会话管理网元发送通知信息的第一信息；以及接收第一多播业务的数据。例如，接收单元1001用于支持通信装置100执行步骤502以及步骤603。
发送单元1002，用于根据第一信息，向会话管理网元发送通知信息，通知信息用于表征第一多播业务的数据到达用户面网元。例如，发送单元1002用于支持通信装置100执行步骤502以及步骤605、步骤606。
具体的，该可能的设计中，上述图5～图6所示方法实施例中涉及用户面网元的各步骤的所有相关内容均可以援引到对应功能模块的功能描述，在此不再赘述。该可能的设计中所述的通信装置100用于执行图5～图6所示数据传输方法中用户面网元的功能，因此可以达到与上述数据传输方法相同的效果。
需要说明的是，作为再一种可实现方式，图10所示通信装置100可以包括：处理模块和通信模块。通信模块可以集成接收单元1001、发送单元1002的功能。处理模块用于对通信装置100的动作进行控制管理，例如，处理模块用于支持该通信装置100执行本文所描述的技术的其它过程。通信模块用于支持通信装置100执行步骤502以及步骤605、步骤606等以及与其他网络实体的通信。进一步的，图10所示通信装置100还可以包括存储模块，用于存储通信装置100的程序代码和数据。当处理模块为处理器，通信模块为通信接口，存储模块为存储器时，图10所示通信装置100可以为图4所示通信装置400。
图11为本申请实施例提供的一种通信装置110的组成示意图，该通信装置110可以为移动性管理网元或者移动性管理网元中的芯片或者片上系统。如图11所示，该通信装置110可以包括：接收单元1101、发送单元1102；
接收单元1101，用于接收来自会话管理网元的第二信息，第二信息用于触发建立第一终端与第一接入网设备之间的通信连接，通信连接用于传输第一多播业务的数据。例如，接收单元1101用于支持通信装置110执行步骤505、以及步骤607。
发送单元1102，用于根据第二信息，向第一接入网设备发送第五信息，第五信息用于第一接入网设备建立与第一终端之间的通信连接。例如，发送单元1102用于支持通信装置110执行步骤505、以及步骤610。
又一种可能的设计中，接收单元1101，用于接收来自会话管理网元的多播群组的用户设备列表UE list，所述多播群组与第一多播业务对应，所述UE list指示加入所述多播群组的终端。例如，接收单元1101用于支持通信装置110执行S8b1。
发送单元1102，用于向所述UE list指示的终端中处于空闲态的终端发送寻呼消息。例如，发送单元1102用于支持通信装置110执行S8b2。
具体的，该可能的设计中，上述图5～图6、图8b所示方法实施例中涉及移动性管理网元的各步骤的所有相关内容均可以援引到对应功能模块的功能描述，在此不再赘述。该可能的设计中的通信装置110用于执行图5～图6、图8b所示数据传输方法中移动性管理网元的功能，因此可以达到与上述数据传输方法相同的效果。
需要说明的是，作为再一种可实现方式，图11所示通信装置110可以包括：处理模块和通信模块。通信模块可以集成接收单元1101、发送单元1102的功能。处理模块用于支持通信装置110对通信装置110的动作进行控制管理，通信模块用于支持通信装置110执行步骤505、步骤607以及步骤610、S8b1、S8b2等以及与其他网络实体的通信。进一步的，图11所示通信装置110还可以包括存储模块，用于存储通信装置110的程序代码和数据。当处理模块为处理器，通信模块为通信接口，存储模块为存储器时，图11所示通信装置110可以为图4所示通信装置400。
图12为本申请实施例提供的一种通信装置120的组成示意图，该通信装置120可以为第一接入网设备或者第一接入网设备中的芯片或者片上系统。如图12所示，该通信装置120可以包括：接收单元1201、处理单元1202、发送单元1203；
接收单元1201，用于接收第一多播业务的数据。例如，接收单元1201可以支持通信装置120执行步骤701以及步骤805。
处理单元1202，用于当在第一多播业务对应的多播群组中存在至少一个由第一接入网设备服务，且处于预设状态的终端时，缓存第一多播业务的数据。例如，处理单元1202可以支持通信装置120执行步骤702以及步骤805。
发送单元1203，用于发送用于寻呼第一终端的寻呼消息，第一终端属于至少一个由第一接入网设备服务，且处于预设状态的终端。例如，发送单元1203可以支持通信装置120执行步骤703以及步骤806。
进一步的，接收单元1201，还可以用于接收来自第一终端的RRC消息，RRC消息用于请求建立第一终端与第一接入网设备之间的通信连接，通信连接用于传输第一多播业务的数据。例如，接收单元1201可以支持通信装置120执行步骤704以及步骤 808。
发送单元1203，还可以用于向第一终端发送第七信息。例如，发送单元1203可以支持通信装置120执行步骤705、步骤809。
具体的，该可能的设计中，上述图7～图8b所示方法实施例中涉及第一接入网设备的各步骤的所有相关内容均可以援引到对应功能模块的功能描述，在此不再赘述。该可能的设计中所述的通信装置120用于执行图7～图8b所示数据传输方法中第一接入网设备的功能，因此可以达到与上述数据传输方法相同的效果。
需要说明的是，作为再一种可实现方式，图12所示通信装置120可以包括：处理模块和通信模块。处理模块可以集成处理单元1202的功能，通信模块可以集成接收单元1201、发送单元1203的功能。处理模块用于支持通信装置120执行步骤702、步骤805以及对通信装置120的动作进行控制管理，通信模块用于支持通信装置120执行步骤701、步骤805、步骤703、步骤806、步骤705、步骤809等以及与其他网络实体的通信。进一步的，图12所示通信装置120还可以包括存储模块，用于存储通信装置120的程序代码和数据。当处理模块为处理器，通信模块为通信接口，存储模块为存储器时，图12所示通信装置120可以为图4所示通信装置400。
图13为本申请实施例提供的一种通信系统的组成示意图，如图13所示，该通信系统可以包括终端130、AMF131、SMF132、RAN133以及UPF134。
其中，SMF132的功能与通信装置90的功能相同。UPF134与通信装置100的功能相同。AMF131与通信装置110的功能相同。RAN133与通信装置120的功能相同。
例如，一种可能的设计中，SMF132，用于在第一多播业务对应的多播群组中存在至少一个处于预设状态的终端130的情况下，向UPF134发送第一信息，UPF134为第一多播业务对应的锚点，第一信息用于指示UPF134在所述第一多播业务的数据到达所述用户面网元时向所述会话管理网元发送通知信息。
UPF134，用于接收来自SMF132的第一信息，当第一多播业务的数据到达UPF134时，UPF134向SMF132发送通知信息，通知信息用于表征第一多播业务的数据到达UPF134。
SMF132，还用于接收UPF134返回的通知信息，根据通知信息向AMF131发送第二信息，第二信息用于触发建立第一终端130与RAN133之间的通信连接，第一终端130为包括在至少一个处于预设状态的终端130中、由移动性网元管理的终端。
AMF131，用于接收来自SMF132的第二信息，根据第二信息，向RAN133发送第五信息，第二信息用于触发建立第一终端130与RAN133之间的通信连接，第五信息用于指示RAN133建立RAN133与第一终端130之间的通信连接。
一种可能的设计中，RAN133，用于接收第一多播业务的数据，当在所述第一多播业务对应的多播群组中存在至少一个由RAN133服务的、且处于预设状态的终端130时，缓存第一多播业务的数据，向第一终端130发送用于寻呼第一终端130的寻呼消息。
又一种可能的设计中，SMF132，用于向AMF131发送多播群组的UE list，多播群组与第一多播业务对应，UE list指示加入多播群组的终端。
AMF131，用于接收来自SMF132的多播群组的用户设备列表UE list，多播群组 与第一多播业务对应，向UE list指示的终端中处于空闲态的终端发送寻呼消息。
具体的，图13中各个网元的执行过程可参照图5-图8b方法中对应网元的执行步骤，不予赘述。
本申请实施例还提供了一种计算机可读存储介质。上述方法实施例中的全部或者部分流程可以由计算机程序来指令相关的硬件完成，该程序可存储于上述计算机可读存储介质中，该程序在执行时，可包括如上述各方法实施例的流程。计算机可读存储介质可以是前述任一实施例的终端装置，如：包括数据发送端和/或数据接收端的内部存储单元，例如终端装置的硬盘或内存。上述计算机可读存储介质也可以是上述终端装置的外部存储设备，例如上述终端装置上配备的插接式硬盘，智能存储卡(smart media card，SMC)，安全数字(secure digital，SD)卡，闪存卡(flash card)等。进一步地，上述计算机可读存储介质还可以既包括上述终端装置的内部存储单元也包括外部存储设备。上述计算机可读存储介质用于存储上述计算机程序以及上述终端装置所需的其他程序和数据。上述计算机可读存储介质还可以用于暂时地存储已经输出或者将要输出的数据。
本申请实施例还提供了一种计算机指令。上述方法实施例中的全部或者部分流程可以由计算机指令来指令相关的硬件(如计算机、处理器、网络设备、和终端等)完成。该程序可被存储于上述计算机可读存储介质中。
应理解，在本申请实施例中，“与A对应的B”表示B与A相关联。例如，可以根据A可以确定B。还应理解，根据A确定B并不意味着仅仅根据A确定B，还可以根据A和/或其它信息确定B。此外，本申请实施例中出现的“连接”是指直接连接或者间接连接等各种连接方式，以实现设备间的通信，本申请实施例对此不做任何限定。
本申请实施例中出现的“传输”(transmit/transmission)如无特别说明，是指双向传输，包含发送和/或接收的动作。具体地，本申请实施例中的“传输”包含数据的发送，数据的接收，或者数据的发送和数据的接收。或者说，这里的数据传输包括上行和/或下行数据传输。数据可以包括信道和/或信号，上行数据传输即上行信道和/或上行信号传输，下行数据传输即下行信道和/或下行信号传输。本申请实施例中出现的“网络”与“系统”表达的是同一概念，通信系统即为通信网络。
在本申请的描述中，除非另有说明，“/”表示前后关联的对象是一种“或”的关系，例如，A/B可以表示A或B；本申请中的“和/或”仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况，其中A,B可以是单数或者复数。并且，在本申请的描述中，除非另有说明，“多个”是指两个或多于两个。“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，或c中的至少一项(个)，可以表示：a，b，c，a-b，a-c，b-c，或a-b-c，其中a，b，c可以是单个，也可以是多个。另外，为了便于清楚描述本申请实施例的技术方案，在本申请实施例中，“示例性的”或者“例如”等词用于表示作例子、例证或说明。本申请实施例中被描述为“示例性的”或者“例如”的任何实施例或设计方案不应被解释为比其它实施例或设计方案更优选或更具优势。确切而言，使用“示例性的”或者“例如”等词旨在以具体方式呈现相关概念，便于理解。
通过以上的实施方式的描述，所属领域的技术人员可以清楚地了解到，为描述的方便和简洁，仅以上述各功能模块的划分进行举例说明，实际应用中，可以根据需要而将上述功能分配由不同的功能模块完成，即将装置的内部结构划分成不同的功能模块，以完成以上描述的全部或者部分功能。
在本申请所提供的几个实施例中，应该理解到，所揭露的装置和方法，可以通过其它的方式实现。例如，以上所描述的装置实施例仅仅是示意性的，例如，所述模块或单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个装置，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口，装置或单元的间接耦合或通信连接，可以是电性，机械或其它的形式。
所述作为分离部件说明的单元可以是或也可以不是物理上分开的，作为单元显示的部件可以是一个物理单元或多个物理单元，即可以位于一个地方，或者也可以分布到多个不同地方。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。
另外，在本申请各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个单元中。上述集成的单元既可以采用硬件的形式实现，也可以采用软件功能单元的形式实现。
所述集成的单元如果以软件功能单元的形式实现并作为独立的产品销售或使用时，可以存储在一个可读取存储介质中。基于这样的理解，本申请实施例的技术方案本质上或者说对现有技术做出贡献的部分或者该技术方案的全部或部分可以以软件产品的形式体现出来，该软件产品存储在一个存储介质中，包括若干指令用以使得一个设备，如：可以是单片机，芯片等，或处理器(processor)执行本申请各个实施例所述方法的全部或部分步骤。而前述的存储介质包括：U盘、移动硬盘、ROM、RAM、磁碟或者光盘等各种可以存储程序代码的介质。
以上所述，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何在本申请揭露的技术范围内的变化或替换，都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应以所述权利要求的保护范围为准。

Claims (49)

  1. 一种数据传输方法，其特征在于，所述方法包括：
    在第一多播业务对应的多播群组中存在至少一个处于预设状态的终端的情况下，会话管理网元向用户面网元发送第一信息，所述第一信息用于所述用户面网元在所述第一多播业务的数据到达所述用户面网元时向所述会话管理网元发送通知信息；
    所述会话管理网元接收来自所述用户面网元所述通知信息，所述通知信息用于表征所述第一多播业务的数据到达所述用户面网元；
    所述会话管理网元根据所述通知信息，向移动性管理网元发送第二信息，所述第二信息用于触发建立第一终端与第一接入网设备之间的通信连接，所述第一终端属于所述至少一个处于所述预设状态的终端；
    其中，所述预设状态包括空闲idle态，非激活inactive态，或者与接入网设备之间不存在用于传输所述第一多播业务的数据的通信连接。
  2. 根据权利要求1所述的方法，其特征在于，
    所述第二信息还用于触发建立第二终端与第二接入网设备之间的通信连接，所述第二终端属于所述至少一个处于所述预设状态的终端。
  3. 根据权利要求2所述的方法，其特征在于，
    所述第二信息包括多播群组的用户设备列表UE list；其中，所述UE list包括所述第一终端的标识信息和所述第二终端的标识信息，所述多播群组与所述第一多播业务对应。
  4. 根据权利要求1-3任一项所述的方法，其特征在于，所述第一信息包括第一识别信息，所述第一识别信息用于识别所述第一多播业务的数据。
  5. 根据权利要求1-4任一项所述的方法，其特征在于，所述方法还包括：
    当所述第一多播业务对应的多播群组中所有终端均存在与接入网设备之间的通信连接时，所述会话管理网元向所述用户面网元发送第三信息，所述第三信息用于通知所述用户面网元发送所述第一多播业务的数据。
  6. 根据权利要求1-4任一项所述的方法，其特征在于，所述方法还包括：
    当所述至少一个处于所述预设状态的终端中所有终端均存在与接入网设备之间的通信连接时，所述会话管理网元向所述用户面网元发送第三信息，所述第三信息用于通知所述用户面网元发送所述第一多播业务的数据。
  7. 根据权利要求1-4任一项所述的方法，其特征在于，在所述向移动性管理网元发送第二信息之后，所述方法还包括：
    所述会话管理网元根据第一预设等待时长，向所述用户面网元发送第三信息，所述第三信息用于通知所述用户面网元发送所述第一多播业务的数据。
  8. 根据权利要求5-7任一项所述的方法，其特征在于，所述第三信息包括第二识别信息，所述第二识别信息用于识别所述第一多播业务的数据。
  9. 根据权利要求1-8任一项所述的方法，其特征在于，所述方法还包括：
    所述会话管理网元接收来自所述移动性管理网元的第四信息，所述第四信息用于去激活所述第一终端的用户面传输资源；
    所述会话管理网元根据所述第四信息，确定所述第一终端处于所述预设状态。
  10. 一种数据传输方法，其特征在于，所述方法包括：
    用户面网元接收来自会话管理网元的第一信息，所述第一信息用于所述用户面网元在第一多播业务的数据到达所述用户面网元时向所述会话管理网元发送通知信息；
    所述用户面网元接收所述第一多播业务的数据；
    所述用户面网元根据所述第一信息，向所述会话管理网元发送所述通知信息，所述通知信息用于表征所述第一多播业务的数据到达所述用户面网元。
  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：
    所述用户面网元缓存所述第一多播业务的数据。
  12. 根据权利要求10或11所述的方法，其特征在于，所述第一信息包括第一识别信息，第一识别信息用于识别所述第一多播业务的数据。
  13. 根据权利要求10-12任一项所述的方法，其特征在于，所述方法还包括：
    所述用户面网元接收来自所述会话管理网元的第三信息，所述第三信息用于通知所述用户面网元发送所述第一多播业务的数据；
    所述用户面网元根据所述第三信息，发送所述第一多播业务的数据。
  14. 根据权利要求13所述的方法，其特征在于，
    所述第三信息包括第二识别信息，所述第二识别信息用于识别所述第一多播业务的数据。
  15. 一种数据传输方法，其特征在于，所述方法还包括：
    移动性管理网元接收来自会话管理网元的第二信息，所述第二信息用于触发建立第一终端与第一接入网设备之间的通信连接，所述通信连接用于传输第一多播业务的数据；
    所述移动性管理网元根据所述第二信息，向所述第一接入网设备发送第五信息，所述第五信息用于所述第一接入网设备建立与所述第一终端之间的通信连接。
  16. 根据权利要求15所述的方法，其特征在于，
    所述移动性管理网元接收来自所述第一接入网设备的第一指示信息，所述第一指示信息用于指示所述第一终端与所述第一接入网设备之间的通信连接建立完成；
    所述移动性管理网元根据所述第一指示信息，向所述会话管理网元发送第二指示信息，所述第二指示信息用于指示所述第一终端与所述第一接入网设备之间的通信连接建立完成。
  17. 根据权利要求15或16所述的方法，其特征在于，所述第二信息还用于触发建立第二终端与第二接入网设备之间的通信连接，所述方法还包括：
    所述移动性管理网元根据所述第二信息，向所述第二接入网设备发送第六信息，所述第六信息用于所述第二接入网设备建立与所述第二终端之间的通信连接。
  18. 根据权利要求17所述的方法，其特征在于，
    所述第二信息包括多播群组的用户设备列表UE list，其中，所述UE list包括所述第一终端的标识信息和所述第二终端的标识信息，所述多播群组与所述第一多播业务对应。
  19. 根据权利要求18所述的方法，其特征在于，所述第二信息还包括所述多播群组的标识信息。
  20. 根据权利要求17-19任一项所述的方法，其特征在于，所述方法还包括：
    所述移动性管理网元确定所述第一终端和所述第二终端处于空闲态；
    所述移动性管理网元在第一寻呼区域发送寻呼消息；其中，所述寻呼消息包括所述多播群组的标识信息，所述第一寻呼区域包括所述第一终端的注册区域和所述第二终端的注册区域。
  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：
    所述移动性管理网元接收来自所述第一终端的业务请求消息；和/或
    所述移动性管理网元接收来自所述第二终端的业务请求消息。
  22. 根据权利要求18-21任一项所述的方法，其特征在于，所述第一寻呼区域还包括所述UE list中除所述第一终端以及所述第二终端之外的终端的注册区域。
  23. 根据权利要求18-21任一项所述的方法，其特征在于，所述第一寻呼区域还包括所述UE list中除所述第一终端以及所述第二终端之外的处于空闲态的终端的注册区域。
  24. 根据权利要求17所述的方法，其特征在于，所述方法还包括:
    所述移动性管理网元接收来自所述第二接入网设备的第三指示信息，所述第三指示信息用于指示所述第二终端与所述第二接入网设备之间的通信连接建立完成；
    所述移动性管理网元根据所述第三指示信息，向所述会话管理网元发送第四指示信息，所述第四指示信息用于指示所述第二终端与所述第二接入网设备之间的通信连接建立完成。
  25. 根据权利要求15所述的方法，其特征在于，
    所述移动性管理网元根据第二预设等待时长，向所述会话管理网元发送第五指示信息，所述第五指示信息用于指示所述会话管理网元触发所述移动性管理网元建立的通信连接均建立完成。
  26. 根据权利要求15所述的方法，其特征在于，当所述第一终端处于空闲态时，所述移动性管理网元向所述第一接入网设备发送第五信息之前，所述方法还包括：
    所述移动性管理网元向所述第一接入网设备发送寻呼消息，所述寻呼消息用于寻呼所述第一终端；
    所述移动性管理网元接收来自所述第一终端的业务请求消息。
  27. 一种数据传输方法，其特征在于，所述方法包括：
    第一接入网设备接收第一多播业务的数据；
    当在所述第一多播业务对应的多播群组中存在至少一个由所述第一接入网设备服务，且处于预设状态的终端时，所述第一接入网设备缓存所述第一多播业务的数据；
    所述第一接入网设备发送寻呼消息，所述寻呼消息用于寻呼第一终端，所述第一终端属于所述至少一个由所述第一接入网设备服务，且处于所述预设状态的终端；
    其中，所述预设状态包括空闲idle态，非激活inactive态，或者与接入网设备之间不存在用于传输所述第一多播业务的数据的通信连接。
  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：
    所述第一接入网设备接收来自所述第一终端的第一无线资源控制RRC消息，所述第一RRC消息用于请求建立所述第一终端与所述第一接入网设备之间的通信连接，所 述通信连接用于传输所述第一多播业务的数据；
    所述第一接入网设备根据所述第一RRC消息，从移动性管理网元获取第五信息，所述第五信息用于建立所述第一终端与所述第一接入网设备之间的通信连接；
    所述第一接入网设备根据所述第五信息，向所述第一终端发送第七信息，所述第七信息用于指示所述第一终端与所述第一接入网设备之间的通信连接的相关配置。
  29. 根据权利要求27或28所述的方法，其特征在于，所述方法还包括：
    当在所述第一多播业务对应的多播群组中不存在由所述第一接入网设备服务，且处于所述预设状态的终端时，所述第一接入网设备发送已缓存的所述第一多播业务的数据；
    或者，所述第一接入网设备根据第三预设等待时长，发送已缓存的所述第一多播业务的数据。
  30. 根据权利要求28或29所述的方法，其特征在于，
    所述第一RRC消息为业务请求消息或者RRC恢复请求消息。
  31. 根据权利要求27-30任一项所述的方法，其特征在于，所述第一接入网设备向第一终端发送寻呼消息包括：
    所述第一接入网设备通过第一信道向所述第一终端发送所述寻呼消息；
    其中，所述第一信道包括以下任意一种：所述第一接入网设备与所述第一终端之间的单播信道、公用信道、所述第一多播业务对应的多播群组的专用信道。
  32. 一种数据传输方法，其特征在于，所述方法包括：
    会话管理网元接收来自移动性管理网元的第四信息，所述第四信息用于去激活第一终端的用户面传输资源；
    所述会话管理网元根据所述第四信息，向所述移动性管理网元发送第二信息，所述第二信息用于建立所述第一终端与第一接入网设备之间的通信连接，所述通信连接用于传输第一多播业务的数据。
  33. 根据权利要求32所述的方法，其特征在于，所述会话管理网元向所述移动性管理网元发送第二信息包括：
    所述会话管理网元向所述移动性管理网元发送订阅请求，所述订阅请求用于请求订阅第一事件，所述第一事件为所述第一终端从所述预设状态转换到连接态；
    所述会话管理网元接收来自所述移动性管理网元事件通知信息，所述事件通知信息用于通知所述第一事件；
    所述会话管理网元根据所述事件通知信息，向所述移动性管理网元发送所述第二信息。
  34. 一种通信系统，其特征在于，所述通信系统包括：
    会话管理网元，用于在第一多播业务对应的多播群组中存在至少一个处于预设状态的终端的情况下，向用户面网元发送第一信息，所述第一信息用于所述用户面网元在所述第一多播业务的数据到达所述用户面网元时向所述会话管理网元发送通知信息；
    所述用户面网元，用于接收来自所述会话管理网元的所述第一信息；
    所述用户面网元，还用于接收所述第一多播业务的数据，根据所述第一信息，向所述会话管理网元发送所述通知信息，所述通知信息用于表征所述第一多播业务的数 据到达所述用户面网元；
    所述会话管理网元，还用于接收来自所述用户面网元所述通知信息，根据所述通知信息，向移动性管理网元发送第二信息，所述第二信息用于触发建立第一终端与第一接入网设备之间的通信连接，所述第一终端属于所述至少一个处于所述预设状态的终端；
    所述移动性管理网元接收来自所述会话管理网元的所述第二信息，根据所述第二信息，向所述第一接入网设备发送第五信息，所述第五信息用于所述第一接入网设备建立与所述第一终端之间的通信连接；
    其中，所述预设状态包括空闲idle态，非激活inactive态，或者与接入网设备之间不存在用于传输所述第一多播业务的数据的通信连接。
  35. 一种通信系统，其特征在于，所述通信系统包括：
    第一接入网设备，用于接收第一多播业务的数据，当在所述第一多播业务对应的多播群组中存在至少一个由所述第一接入网设备服务，且处于预设状态的终端时，所述第一接入网设备缓存所述第一多播业务的数据；
    所述第一接入网设备，还用于发送寻呼消息，所述寻呼消息用于寻呼第一终端，所述第一终端属于所述至少一个由所述第一接入网设备服务，且处于所述预设状态的终端；
    其中，所述预设状态包括空闲idle态，非激活inactive态，或者与接入网设备之间不存在用于传输所述第一多播业务的数据的通信连接。
  36. 一种数据传输方法，其特征在于，所述方法还包括：
    移动性管理网元接收来自会话管理网元的多播群组的用户设备列表UE list，所述多播群组与第一多播业务对应，所述UE list指示加入所述多播群组的终端；
    所述移动性管理网元确定所述UE list指示的终端中处于空闲态的终端，向所述处于空闲态的终端发送寻呼消息。
  37. 根据权利要求36所述的方法，其特征在于，
    所述第二信息还包括所述多播群组的标识信息。
  38. 根据权利要求36或37所述的方法，其特征在于，所述处于空闲态的终端包括所述第一终端和所述第二终端，所述移动性管理网元向所述处于空闲态的终端发送寻呼消息包括：
    所述移动性管理网元在第一寻呼区域发送寻呼消息；其中，所述寻呼消息包括所述多播群组的标识信息，所述第一寻呼区域包括所述第一终端的注册区域和所述第二终端的注册区域。
  39. 根据权利要求38所述的方法，其特征在于，所述方法还包括：
    所述移动性管理网元接收来自所述第一终端的业务请求消息；和/或
    所述移动性管理网元接收来自所述第二终端的业务请求消息。
  40. 根据权利要求36-39任一项所述的方法，其特征在于，所述第一寻呼区域还包括所述UE list中除所述第一终端以及所述第二终端之外的终端的注册区域。
  41. 根据权利要求36-39任一项所述的方法，其特征在于，所述第一寻呼区域还包括所述UE list中除所述第一终端以及所述第二终端之外的处于空闲态的终端的注册区 域。
  42. 一种通信装置，其特征在于，所述通信装置包括一个或者多个处理器、通信接口，所述一个或者多个处理以及所述通信接口用于支持所述通信装置执行如权利要求1-9任一项所述的数据传输方法或者权利要求32-33任一项所述的数据传输方法。
  43. 一种计算机可读存储介质，其特征在于，所述计算机可读存储介质包括计算机指令，当所述计算机指令在计算机上运行时，使得所述计算机执行如权利要求1-9任一项所述的数据传输方法或者权利要求32-33任一项所述的数据传输方法。
  44. 一种通信装置，其特征在于，所述通信装置包括一个或者多个处理器、通信接口，所述一个或者多个处理以及所述通信接口用于支持所述通信装置执行如权利要求10-14任一项所述的数据传输方法。
  45. 一种计算机可读存储介质，其特征在于，所述计算机可读存储介质包括计算机指令，当所述计算机指令在计算机上运行时，使得所述计算机执行如权利要求10-14任一项所述的数据传输方法。
  46. 一种通信装置，其特征在于，所述通信装置包括一个或者多个处理器、通信接口，所述一个或者多个处理以及所述通信接口用于支持所述通信装置执行如权利要求15-26任一项所述的数据传输方法或者权利要求36-41任一项所述的方法。
  47. 一种计算机可读存储介质，其特征在于，所述计算机可读存储介质包括计算机指令，当所述计算机指令在计算机上运行时，使得所述计算机执行如权利要求15-26任一项所述的数据传输方法或者权利要求36-41任一项所述的方法。
  48. 一种通信装置，其特征在于，所述通信装置包括一个或者多个处理器、通信接口，所述一个或者多个处理以及所述通信接口用于支持所述通信装置执行如权利要求27-31任一项所述的数据传输方法。
  49. 一种计算机可读存储介质，其特征在于，所述计算机可读存储介质包括计算机指令，当所述计算机指令在计算机上运行时，使得所述计算机执行如权利要求27-31任一项所述的数据传输方法。
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