WO2022237500A1 - 一种通信方法及装置 - Google Patents

一种通信方法及装置 Download PDF

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Publication number
WO2022237500A1
WO2022237500A1 PCT/CN2022/088563 CN2022088563W WO2022237500A1 WO 2022237500 A1 WO2022237500 A1 WO 2022237500A1 CN 2022088563 W CN2022088563 W CN 2022088563W WO 2022237500 A1 WO2022237500 A1 WO 2022237500A1
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Prior art keywords
session
multicast
terminal
network element
message
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PCT/CN2022/088563
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English (en)
French (fr)
Inventor
贾建鑫
吴问付
宗在峰
朱奋勤
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华为技术有限公司
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Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to EP22806470.5A priority Critical patent/EP4319209A1/en
Publication of WO2022237500A1 publication Critical patent/WO2022237500A1/zh
Priority to US18/506,908 priority patent/US20240080931A1/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/20—Manipulation of established connections
    • 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
    • H04W68/00—User notification, e.g. alerting and paging, for incoming communication, change of service or the like
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/20—Manipulation of established connections
    • H04W76/22—Manipulation of transport tunnels
    • 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
    • H04W68/00—User notification, e.g. alerting and paging, for incoming communication, change of service or the like
    • H04W68/02—Arrangements for increasing efficiency of notification or paging channel
    • 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
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/14—Backbone network devices

Definitions

  • the embodiments of the present application relate to the field of communication technologies, and in particular, to a communication method and device.
  • the 5th generation (5G) mobile communication network architecture can support multicast/broadcast functions, and send multicast/broadcast service data to a large number of users through multicast/broadcast.
  • 5G 5th generation
  • Embodiments of the present application provide a communication method and device to optimize the processing flow of multicast services.
  • the embodiment of the present application provides a communication method, the method includes: the first session management function network element receives from the second session management function network element for notifying the activation of the multicast session or for notifying the multicast session
  • the released first message according to the first message, sends the first information to the access and mobility management functional network element, the first information includes identification information and/or indication information of the multicast session, and the indication information is used to indicate group paging .
  • the second session management function network element corresponds to the multicast session.
  • the first session management functional network element may send indication information to the access and mobility management functional network element, indicating that the access and mobility management functional network Paging the terminal group corresponding to the multicast session to optimize the paging area of the terminal corresponding to the multicast session, and not to repeatedly send paging messages in overlapping areas, optimize the paging process, and reduce the number of terminals in the paging multicast group signaling overhead.
  • the method further includes: the first session management function network element determines, according to the first message, that the number of deactivated PDU sessions in the PDU sessions associated with the multicast session meets a preset condition. Based on this possible design, the group paging instruction can be sent after the deactivated PDU sessions in the PDU sessions associated with the multicast session meet the preset conditions, reducing the paging signaling process when there are many PDU sessions in the deactivated state .
  • the indication information includes first indication information or second indication information; wherein, the first indication information is used to indicate that the terminal corresponding to the multicast session is paging in a group paging manner, or the second indication information is used to Indicates to use the group paging method to page the terminal corresponding to the PDU session in the deactivated state.
  • the terminal can be used as the granularity of group paging, or the PDU session can be used as the granularity of group paging to effectively and flexibly indicate the object of group paging.
  • the first information is carried in N1N2 message transmission; or, the first information is carried in N11 message. Based on this possible design, the carrier carrying the first information is efficiently and flexibly designed while simplifying the system design.
  • the embodiment of the present application further provides a communication method, the method including: the access and mobility management function network element receives the identification information and/or indication including the multicast session from the first session management function network element
  • the first information of the information indicates that the information is used to indicate group paging; the access and mobility management function network element performs group paging according to the first information.
  • the access and mobility management functional network element receives an indication from the first session management functional network element, and paging the terminal group corresponding to the multicast session, In order to optimize the paging area of the terminal corresponding to the multicast session, the paging message is not sent repeatedly in overlapping areas, the paging process is optimized, and the signaling overhead caused by paging the terminal in the multicast group is reduced.
  • the indication information includes first indication information or second indication information; wherein, the first indication information is used to indicate that the terminal corresponding to the multicast session is paging in a group paging manner, or the second indication information is used to Indicates to use the group paging method to page the terminal corresponding to the PDU session in the deactivated state.
  • the terminal can be used as the granularity of group paging, or the PDU session can be used as the granularity of group paging to effectively and flexibly indicate the object of group paging.
  • the first information is carried in N1N2 message transmission; or, the first information is carried in N11 message. Based on this possible design, the carrier carrying the first information is efficiently and flexibly designed while simplifying the system design.
  • the access and mobility management function network element paging according to the first information group includes: the access and mobility management function network element determines to join the multicast session according to the first information and is in the CM-IDLE state terminal; the access and mobility management function network element sends a paging message in the paging area of the terminal that joins the multicast session and is in the CM-IDLE state according to the indication information, and the paging message includes the identification information of the multicast session;
  • the paging areas of the terminals in the CM-IDLE state include the union of the registration areas of the terminals in the CM-IDLE state.
  • paging messages are not sent repeatedly in overlapping areas, reducing signaling overhead caused by paging.
  • an embodiment of the present application provides a communication method, the method including: the network element with the access and mobility management function receives a message from the first network element with the session management function for the network element with the access and mobility management function to The terminal in the CM-CONNECTED state indicates/notifies the second message to the first session management function network element, and sends a third message to the first session management function network element according to the second message; wherein, the third message includes the first Identification information of the terminal and/or identification information of the multicast session; the first session management function network element is used to manage the PDU session associated with the multicast session in the protocol data unit PDU session of the first terminal, and the terminal in the CM-CONNECTED state including the first terminal.
  • the first session management function network element may instruct the access and mobility management function network element to indicate the terminal in CM-CONNECTED to the first session management function network element, triggering the first session management function
  • the network element sends relevant information for configuring the radio bearer corresponding to the multicast session to the access network device corresponding to the first terminal, so as to ensure that the first terminal can normally receive data of the multicast service.
  • the first session management function network element is triggered to instruct the access network device to release resources used for transmitting multicast service data to the first terminal, so as to improve resource utilization.
  • the second message includes identification information of the multicast session.
  • the multicast session can be used as the granularity to instruct the terminals that join the multicast session and are in the CM-CONNECTED state to indicate to the first session management function network element, which simplifies the system design.
  • the second message is also used to instruct the access and mobility management functional network element to page the terminal in the CM-IDLE state.
  • the second message is also used to instruct the access and mobility management functional network element to page the terminal in the CM-IDLE state.
  • the access and mobility management functional network element if there is a terminal in the CM-IDLE state, page the terminal in the CM-IDLE state, and change the terminal to the CM-CONNECTED state to ensure that the first session management network element communicates with the terminal
  • the corresponding communication interface configures related information of radio bearers or releases related resources for the terminal.
  • the access and mobility management functional network element sends the third message to the first session management functional network element according to the second message, including: the access and mobility management functional network element, according to the second message, Paging terminals that have joined the multicast session and are in the CM-IDLE state; the terminals in the CM-IDLE state include the first terminal; the access and mobility management function network element receives a service request from the first terminal, and accesses and The network element with the mobility management function sends the third message to the first network element with the session management function.
  • the network element with the access and mobility management function pages the terminal in the CM-IDLE state according to the second message, including: the network element with the access and mobility management function Multicast capability information of the access network device in the registration area of the terminal in the CM-IDLE state of the multicast session, and paging the terminal that has joined the multicast session and is in the CM-IDLE state.
  • the access and mobility management functional network element pages the multicast session that has joined the multicast session according to the second message and the multicast capability information of the access network device in the registration area of the terminal in the CM-IDLE state
  • the terminal in the CM-IDLE state includes: if the first access network device in the registration area of the first terminal supports the multicast function, the network element with the access and mobility management function sends a paging message to the first access network device
  • the paging message includes the identification information of the multicast session, and the terminal in the CM-IDLE state includes the first terminal; if the second access network device in the registration area of the first terminal does not support the multicast function, the access and mobile
  • the network element with the property management function sends a paging message to the second access network device, where the paging message includes identification information of the first terminal.
  • an access network device that supports the multicast function, send a paging message carrying the identification information of the multicast session to the access network device, so that the access network device can identify the multicast session included in the paging message.
  • the identification information of the session according to the identification information of the multicast session, initiates group paging to multiple terminals that have joined the multicast session and are in the CM-IDLE state, saving signaling overhead.
  • the network element with the access and mobility management function pages the terminal that has joined the multicast session and is in the CM-IDLE state according to the second message, including: the network element with the access and mobility management function according to the second message message, sending a fourth message to the access network device corresponding to the first terminal, where the fourth message includes identification information of the first terminal and identification information of the multicast session; terminals in the CM-IDLE state include the first terminal.
  • the access network device corresponding to the first terminal it is convenient for the access network device corresponding to the first terminal to flexibly select a paging mode according to its own multicast capability information.
  • the access and mobility management function network element sends the third message to the first session management function network element according to the second message, including: the access and mobility management function network element receives the second message , if there are terminals in the CM-CONNECTED state, the access and mobility management functional network element sends a third message to the first session management functional network element, and the existing terminals in the CM-CONNECTED state include the first terminal.
  • the terminal in the CM-CONNECTED state can be directly indicated to the first session management function network element without paging the terminal, which simplifies the system design.
  • the embodiment of the present application provides a communication method, the method includes: the first session management function network element sends the access and mobility management function network element to the access and mobility management function network element will be in The terminal in the CM-CONNECTED state indicates the second message to the first session management function network element; the first session management function network element receives the third message from the access and mobility management function network element; wherein, the third message includes the first Identification information of a terminal and/or identification information of a multicast session; the first session management function network element is used to manage the PDU session associated with the multicast session in the PDU session of the first terminal, and the terminal in the CM-CONNECTED state includes the first a terminal.
  • the first session management function network element may instruct the access and mobility management function network element to indicate the terminal in CM-CONNECTED to the first session management function network element, and receive the access and mobility
  • the first session management function network element can learn the CM status of the terminal, so that the first session management function network element can perform follow-up work according to the CM status of the terminal.
  • the method further includes: the first session management function network element receives a first message from the second session management function network element for notifying the activation of the multicast session or for notifying the release of the multicast session, The second session management function network element corresponds to the multicast session; the sending of the second message by the first session management function network element to the access and mobility management function network element includes: the first session management function network element transmits the second message to the access and mobility management function network element according to the first message The network element with the mobility management function sends the second message. Based on this possible design, the second message can be sent to the access and mobility management functional network element in the scenario of multicast session activation or multicast session release, expanding the application scenarios of the method.
  • the second message includes identification information of the multicast session.
  • the multicast session can be used as the granularity to instruct the terminals that join the multicast session and are in the CM-CONNECTED state to indicate to the first session management function network element, which simplifies the system design.
  • the second message is also used to page terminals that have joined the multicast session and are in the connection management-idle CM-IDLE state, and the second message includes identification information of the multicast session. Based on this possible design, if there is a terminal in the CM-IDLE state, page the terminal in the CM-IDLE state, and change the terminal to the CM-CONNECTED state to ensure that the first session management network element communicates with the terminal
  • the corresponding communication interface configures related information of radio bearers or releases related resources for the terminal.
  • the method further includes: the first session management function network element sends second information to the access network device corresponding to the first terminal according to the third message;
  • the device configures a radio bearer for transmitting the data of the multicast service to the first terminal, or the second information is used for the access network device to release resources for transmitting the data of the multicast service to the first terminal.
  • the resource includes a radio bearer for transmitting data of the multicast service to the first terminal and/or multicast QoS information corresponding to the multicast service and/or unicast QoS information corresponding to the multicast QoS information.
  • the first session management function network element can send the relevant information for configuring the radio bearer corresponding to the multicast session to the access network device corresponding to the first terminal, so as to ensure that the first terminal can normally receive multicast services The data.
  • the first session management function network element is triggered to instruct the access network device to release resources used for transmitting multicast service data to the first terminal, so as to improve resource utilization.
  • the second information is used by the access network device to configure a radio bearer for transmitting data of the multicast service to the first terminal;
  • the second information includes at least one of the following: identification information of the multicast session, group The multicast QoS information corresponding to the multicast session, the unicast QoS information corresponding to the multicast QoS information, or the unicast QoS flow ID corresponding to the multicast QoS flow QoS Flow.
  • the second information is used by the access network device to release resources used to transmit data of the multicast service to the first terminal, and the resource includes a radio bearer used to transmit data of the multicast service to the first terminal,
  • the second information includes at least one of the following: identification information of the multicast session, and information corresponding to the multicast QoS Flow Unicast QoS Flow ID, multicast quality of service QoS information corresponding to the multicast session, unicast QoS information corresponding to the multicast QoS information, or a release indication; data resource.
  • the embodiment of the present application provides a communication method, the method including: the access network device determines the activation of the multicast session corresponding to the multicast service; the access network device corresponds to the access and mobility management of the first terminal
  • the functional network element sends a sixth message; wherein, the sixth message is used to indicate that the multicast session is activated, the sixth message includes identification information of the multicast session, and the first terminal is a terminal joining the multicast session.
  • the access network device after the access network device activates the multicast session, the access network device notifies the first session management function network element to also activate the multicast session through the access and mobility management function network element, so that Ensure the consistency of the multicast session status maintained between network elements.
  • the network element of the core network there is no need for the network element of the core network to notify the access network device corresponding to the terminal to join the multicast session with the terminal as the granularity, reducing signaling overhead.
  • the terminal joining the multicast session also includes a second terminal
  • the method further includes: the access network device sends a seventh message to the access and mobility management functional network element corresponding to the second terminal; wherein , the seventh message is used to indicate that the multicast session is activated, and the seventh message includes identification information of the multicast session.
  • the access network device may indicate the activation of the multicast session to the access and mobility management function network element, so that the access and mobility management function network element notifies the first session management function network element of the multicast session activation, Triggering the first session management function network element to update the multicast session status and so on.
  • the method further includes: when the access network device receives the data of the multicast service from the MB-UPF, the access network device determines that the multicast session corresponding to the multicast service is activated. Based on this possible design, the activation of the multicast session corresponding to the multicast service can be known from the data transmission on the user plane.
  • the method further includes: the access network device receives an eighth message from the access and mobility management functional network element; wherein the eighth message is used to indicate activation of the multicast session, and the eighth message includes Identification information of the multicast session; the access network device determines the activation of the multicast session corresponding to the multicast service according to the eighth message. Based on this possible design, the activation of the multicast session corresponding to the multicast service can be known from the signaling message on the control plane.
  • the method further includes: the access network device configures the unicast radio bearer according to the unicast QoS information; wherein, the unicast QoS information corresponds to the QoS information of the multicast session, and the unicast radio bearer uses It is used to transmit the data of the multicast service through the PDU session.
  • the access network device configures the unicast radio bearer according to the unicast QoS information; wherein, the unicast QoS information corresponds to the QoS information of the multicast session, and the unicast radio bearer uses It is used to transmit the data of the multicast service through the PDU session.
  • the method further includes: the access network device receives a ninth message from the first session management function network element; wherein, the ninth message includes identification information of the PDU session; the ninth message is used to indicate the Activate the PDU session; set the access network to reserve the unicast QoS information corresponding to the multicast QoS information of the multicast session in the context of the PDU session according to the ninth message.
  • the access network device receives a ninth message from the first session management function network element; wherein, the ninth message includes identification information of the PDU session; the ninth message is used to indicate the Activate the PDU session; set the access network to reserve the unicast QoS information corresponding to the multicast QoS information of the multicast session in the context of the PDU session according to the ninth message.
  • the ninth message further includes identification information of the multicast session and/or fourth indication information, and the fourth indication information indicates to reserve unicast QoS information corresponding to the multicast quality of service QoS information of the multicast session;
  • the access network device retains the unicast QoS information corresponding to the multicast quality of service QoS information of the multicast session in the context of the PDU session, including: the access network device retains the context of the PDU session according to the fourth indication information The unicast QoS information corresponding to the multicast quality of service QoS information of the multicast session.
  • the access network device reserves the unicast QoS information corresponding to the multicast quality of service QoS information of the multicast session in the context of the PDU session according to the ninth message, including: the access network device determines that the PDU session is related to If the multicast session is associated, the access network device retains the unicast QoS information corresponding to the multicast QoS information of the multicast session in the context of the PDU session.
  • the embodiment of the present application provides a communication method, the method comprising: an access and mobility management function network element receives a sixth message from an access network device for indicating activation of a multicast session; the sixth message Including the identification information of the multicast session; the access and mobility management function network element sends the tenth message to the first session management function network element according to the sixth message; wherein, the tenth message is used to indicate the activation of the multicast session, and the tenth message The message includes identification information of the multicast session.
  • the access and mobility management functional network element notifies the first session management functional network element to also activate the multicast session, so as to ensure The maintained multicast session state is consistent.
  • the network element of the core network there is no need for the network element of the core network to notify the access network device corresponding to the terminal to join the multicast session with the terminal as the granularity, reducing signaling overhead.
  • the method further includes: the access and mobility management function network element receives a notification of multicast session activation from the second session management function network element; the second session management function network element corresponds to the multicast session; the access and mobility management function network element sends an eighth message to the access network device according to the notification of the activation of the multicast session; wherein, the eighth message is used to indicate the activation of the multicast session, and the eighth message includes the information of the multicast session Identification information.
  • the embodiment of the present application provides a communication method, the method comprising: the first session management function network element receives the tenth message from the access and mobility management function network element for indicating the activation of the multicast session; The first session management functional network element sets the state of the multicast session to the active state according to the tenth message.
  • the access network device after the access network device activates the multicast session, the access network device notifies the access and mobility management function network element to notify the first session management function network element to also activate the multicast session, so that Ensure the consistency of the multicast session status maintained between network elements.
  • the network element of the core network there is no need for the network element of the core network to notify the access network device corresponding to the terminal to join the multicast session with the terminal as the granularity, reducing signaling overhead.
  • the method further includes: if there is a PDU session associated with the multicast, and the state of the PDU session is deactivated, the first session management functional network element activates the PDU session.
  • the method further includes: the first session management function network element determines to deactivate the PDU session; the first session management function network element sends a ninth message to the access network device; wherein the ninth message contains the PDU The identification information of the session; the ninth message is used to indicate to deactivate the PDU session.
  • the ninth message further includes fourth indication information and/or identification information of the multicast session, and the fourth indication information indicates the unicast QoS corresponding to the multicast quality of service QoS information of the multicast session in the context of the reserved PDU session information.
  • the unicast QoS information corresponding to the multicast QoS information of the multicast session can be retained, so that the terminal can subsequently establish a wireless bearer for transmitting data of the multicast service according to the QoS information. Ensure the normal transmission of multicast data.
  • the present application provides a communication device.
  • the communication device may be a first session management function network element or a chip or a system-on-chip in the first session management function network element, and may also be a communication device used to implement the first
  • the communication device can realize the above aspects or the functions performed by the communication device in each possible design, and the functions can be realized by executing corresponding software through hardware.
  • the hardware or software includes one or more modules with corresponding functions above.
  • the communication device may include: a processing unit, a receiving unit, and a sending unit.
  • the receiving unit is configured to receive the first message from the second session management function network element, the second session management function network element corresponds to the multicast session, and the first message is used to notify the activation of the multicast session or It is used to notify the release of the multicast session.
  • the sending unit is configured to send the first information to the access and mobility management function network element according to the first message, the first information includes identification information and/or indication information of the multicast session, and the indication information is used to indicate group paging.
  • the sending unit is configured to send a second message to the network element with the access and mobility management function; wherein, the second message is used for the network element with the access and mobility management function to join the multicast session and the terminal in the connection management-connection CM-CONNECTED state indicates to the first session management function network element;
  • a receiving unit configured to receive a third message from an access and mobility management functional network element; wherein, the third message includes identification information of the first terminal and/or identification information of a multicast session; the first session management functional network element It is used to manage the PDU session associated with the multicast session among the protocol data unit PDU sessions of the first terminal, and the terminals in the CM-CONNECTED state include the first terminal.
  • the receiving unit is configured to receive a tenth message from an access and mobility management functional network element; the tenth message is used to indicate the activation of the multicast session, and the tenth message includes identification information of the multicast session .
  • the processing unit is configured to set the state of the multicast session to an active state according to the tenth message.
  • the specific implementation of the communication device can refer to the method described in the first aspect or any possible design of the first aspect or the fourth aspect or any possible design of the fourth aspect or the seventh aspect or the first aspect.
  • the behavior and function of the first session management function network element in any possible design of the seven aspects will not be repeated.
  • a communication device may be a first session management function network element or a chip or a system-on-chip in the first session management function network element, and the communication device includes one or more processors, a or multiple memories.
  • the one or more memories are coupled to the one or more processors, the one or more memories are used to store computer program codes, the computer program codes include computer instructions, and when the one or more processors execute the When using the above computer instructions, make the communication device execute the method described in the first aspect or any possible design of the first aspect or the fourth aspect or any possible design of the fourth aspect or the seventh aspect or the seventh aspect Any possible design of the described method.
  • a computer program product containing instructions, which, when run on a computer, cause the computer to execute the first aspect or any possible design of the first aspect, or the fourth aspect or any possible design of the fourth aspect.
  • a computer-readable storage medium may be a readable non-volatile storage medium. Instructions are stored in the computer-readable storage medium. When the computer-readable storage medium is run on a computer , make the computer execute the method described in the first aspect or any possible design of the first aspect or the fourth aspect or any possible design of the fourth aspect or the seventh aspect or any possible design of the seventh aspect Design the method described.
  • the present application provides a communication device.
  • the communication device may be an access and mobility management functional network element or a chip or a system-on-chip in an access and mobility management functional network element, or may be a A functional module for realizing the second aspect or any possible design of the second aspect, or a functional module for realizing the third aspect or any possible design of the third aspect, or realizing the first
  • the communication device can realize the above aspects or the functions performed by the communication device in each possible design, and the functions can be realized by executing corresponding software through hardware.
  • the hardware or software includes one or more modules with corresponding functions above.
  • the communication device may include: a processing unit, a receiving unit, and a sending unit.
  • the receiving unit is configured to receive first information from the first session management function network element, where the first information includes identification information and/or indication information of the multicast session, and the indication information is used to indicate group paging .
  • a processing unit configured to set paging according to the first information group.
  • the receiving unit is configured to receive a second message from the first session management function network element; wherein, the second message is used to indicate that the access and mobility management function network element will be in the CM-CONNECTED state
  • the terminal indicates to the first session management function network element.
  • the sending unit is configured to send a third message to the first session management function network element according to the second message; wherein, the third message includes the identification information of the first terminal and/or the identification information of the multicast session; the first session management function
  • the network element is used to manage the PDU session associated with the multicast session among the protocol data unit PDU sessions of the first terminal, and the terminals in the CM-CONNECTED state include the first terminal.
  • the receiving unit is configured to receive a sixth message from the access network device; wherein the sixth message is used to indicate activation of the multicast session, and the sixth message includes identification information of the multicast session.
  • the sending unit 1103 is configured to send a tenth message to the first session management function network element according to the sixth message; wherein, the tenth message is used to indicate activation of the multicast session, and the tenth message includes identification information of the multicast session.
  • the communication device may include: a processor and a communication interface.
  • the communication device may further include a memory, and the memory is used for storing necessary computer-executed instructions and data of the communication device.
  • the processor executes the computer-executable instructions stored in the memory to implement the above method.
  • the specific implementation of the communication device can refer to the method described in the second aspect or any possible design of the second aspect or the third aspect or any possible design of the third aspect or the sixth aspect or the first
  • the method described in any possible design of the sixth aspect or the behavior of the access and mobility management functional network element in the sixth aspect or the method described in any possible design of the sixth aspect will not be repeated.
  • a communication device may be an access and mobility management function network element or a chip or a system on a chip in an access and mobility management function network element.
  • the communication device includes one or more processors, and one or more memories.
  • the one or more memories are coupled to the one or more processors, the one or more memories are used to store computer program codes, the computer program codes include computer instructions, and when the one or more processors execute the When using the above computer instructions, make the communication device execute the method described in the second aspect or any possible design of the second aspect or the third aspect or any possible design of the third aspect or the sixth aspect or the sixth aspect The method described in any possible design of the sixth aspect or the method described in any possible design of the sixth aspect.
  • a fourteenth aspect there is provided a computer program product containing instructions, which, when run on a computer, causes the computer to execute any possible design of the second aspect or the second aspect, or the third aspect or the third aspect Any possible design of the method or the sixth aspect or any possible design of the sixth aspect or the method of the sixth aspect or any possible design of the sixth aspect.
  • a computer-readable storage medium may be a readable non-volatile storage medium. Instructions are stored in the computer-readable storage medium. When the computer-readable storage medium is run on a computer When, make the computer execute the method described in the second aspect or any possible design of the second aspect or the third aspect or any possible design of the third aspect or the sixth aspect or any possible design of the sixth aspect Design the described method or the sixth aspect or any possible design of the sixth aspect.
  • the present application provides a communication device.
  • the communication device may be an access network device or a chip or a system on a chip in the access network device, and may also be used in the communication device to implement the fifth aspect or the fifth aspect Any possible design of the functional modules of the method.
  • the communication device can realize the above aspects or the functions performed by the communication device in each possible design, and the functions can be realized by executing corresponding software through hardware.
  • the hardware or software includes one or more modules with corresponding functions above.
  • the communication device may include: a processing unit, a receiving unit, and a sending unit.
  • the processing unit is configured to determine the activation of the multicast session corresponding to the multicast service.
  • a sending unit configured to send a sixth message to an access network device corresponding to the first terminal; wherein the sixth message is used to indicate activation of the multicast session, and the sixth message includes an identifier of the multicast session Information, the first terminal is a terminal joining the multicast session.
  • a communication device may be an access network device or a chip or a system on a chip in the access network device, and the communication device includes one or more processors and one or more memories.
  • the one or more memories are coupled to the one or more processors, the one or more memories are used to store computer program codes, the computer program codes include computer instructions, and when the one or more processors execute the When the above computer instructions are used, the communication device is made to execute the method described in the fifth aspect or any possible design of the fifth aspect.
  • a computer program product containing instructions, which when run on a computer, causes the computer to execute the method described in the fifth aspect or any possible design of the fifth aspect.
  • a computer-readable storage medium may be a readable non-volatile storage medium, and instructions are stored in the computer-readable storage medium.
  • the computer-readable storage medium is run on a computer When, make the computer execute the method described in the fifth aspect or any possible design of the fifth aspect.
  • a communication system which may include the communication device as described in the eighth aspect, and the communication device as described in the twelfth aspect, and may also include the communication device as described in the sixteenth aspect. communication device.
  • FIG. 1 is a schematic diagram of a terminal joining a multicast session provided by an embodiment of the present application
  • FIG. 2 is a schematic structural diagram of a communication system provided by an embodiment of the present application.
  • FIG. 3a is a schematic diagram of the architecture of a 5G communication system provided by an embodiment of the present application.
  • FIG. 3b is a schematic diagram of another 5G communication architecture provided by the embodiment of the present application.
  • FIG. 3c is a schematic diagram of a multicast/broadcast service transmission mode provided by an embodiment of the present application.
  • FIG. 4 is a schematic diagram of the composition of a communication device 400 provided in an embodiment of the present application.
  • FIG. 5 is a flowchart of a communication method provided by an embodiment of the present application.
  • FIG. 6 is a flowchart of a communication method provided by an embodiment of the present application.
  • FIG. 7 is a flowchart of a communication method provided by an embodiment of the present application.
  • FIG. 8 is a flowchart of a communication method provided by an embodiment of the present application.
  • FIG. 9 is a flowchart of a communication method provided by an embodiment of the present application.
  • FIG. 10 is a schematic diagram of the composition of a communication device 100 provided by an embodiment of the present application.
  • FIG. 11 is a schematic diagram of the composition of a communication device 110 provided by an embodiment of the present application.
  • FIG. 12 is a schematic diagram of the composition of a communication device 120 provided by an embodiment of the present application.
  • FIG. 13 is a schematic diagram of a communication system provided by an embodiment of the present application.
  • the multiple terminals when multiple terminals have a multicast service requirement, the multiple terminals can join the multicast session, and receive data of the multicast service through the multicast session.
  • a multicast session can be shared by multiple terminals, and the application server side can deliver a copy of multicast service data to multicast user plane function network elements (such as multicast broadcast-user plane function (MB- UPF), after MB-UPF receives the multicast service data, it sends the multicast service data to multiple terminals through the multicast session.
  • multicast user plane function network elements such as multicast broadcast-user plane function (MB- UPF)
  • MB-UPF After MB-UPF receives the multicast service data, it sends the group
  • the data of the multicast service is sent to the access network device, and the access network device receives the data of the multicast service transmitted on the multicast session, and sends the multicast to multiple terminals in a point-to-multipoint (PTM) manner
  • PTM point-to-multipoint
  • PTP point-to-point
  • multicast in this application is a broad concept, which can include multicast or broadcast, that is, this embodiment of the application can be applied to both multicast service transmission and broadcast business transmission.
  • Multicast mentioned in this application can be replaced with "multicast or broadcast”.
  • the multicast session (multicast session) in this application can be replaced by a multicast service session (multicast service session) or a multicast broadcast service session (multicast broadcast service session, MBS session), which is not limited.
  • the terminal joining the multicast session can be described as the terminal joining the multicast service or the multicast broadcast service (multicast broadcast service, MBS), or the terminal joining the multicast group corresponding to the multicast session.
  • MBS multicast broadcast service
  • the terminal may have one or more protocol data unit (protocol data unit, PDU) sessions, the terminal may select a PDU session from one or more PDU sessions of the terminal, and join the group through the PDU session of the terminal broadcast session.
  • PDU protocol data unit
  • the terminal can join the multicast group through the control plane message of the terminal's PDU session (for example, PDU session establishment/modification request (PDU session establishment/modification request)), and the control plane message carries the identifier of the multicast session information and instructions for joining a multicast group, etc.
  • the terminal may send a control plane message to the session management function network element corresponding to the PDU session of the terminal (in this application, it may be referred to as the first session management function network element or the unicast session management function network element or SMF).
  • the session management function network element After the session management function network element receives the control plane message, if the session management function network element has not received the multicast quality of service (quantity of service, QoS) information of the multicast service before (or called the multicast session corresponding QoS information), then the session management function network element from the multicast session management function network element (this application may be referred to as the second session management function network element or multicast broadcast-session management function (multicast broadcast-session management function, MB- SMF) extracts the multicast QoS information of the multicast service. Further optional, the multicast session management function network element can interact with other network elements to add the terminal to the multicast session.
  • QoS quality of service
  • MB- SMF multicast broadcast-session management function
  • the terminal can join the PDU session through the user plane notification message (for example, Internet group management protocol/multicast listener discovery protocol (internet group management protocol/multicast listener discovery join, IGMP/MLD join) of the terminal's PDU session.
  • the user plane notification message for example, Internet group management protocol/multicast listener discovery protocol (internet group management protocol/multicast listener discovery join, IGMP/MLD join) of the terminal's PDU session.
  • the user plane notification message for a multicast group, the user plane notification message carries, for example, the identification information of the multicast session and the indication information to join the multicast group.
  • the terminal can send the user plane notification message to the UPF corresponding to the PDU session of the terminal, and the UPF receives the user plane notification message.
  • the session management function network element After the notification message, notify the session management function network element corresponding to the terminal's PDU session that the terminal joins the multicast session, and the session management function network element corresponding to the terminal's PDU session receives the notification. If the session management function network element has not received the multicast before The multicast QoS information of business, the session management function network element extracts the relevant multicast QoS information of multicast service from the multicast session management function network element.Further optional, the multicast session management function network element can interact with other network elements Join the terminal to the multicast session.
  • the identification information of the multicast session may be used to identify the multicast session.
  • the identification information of the multicast session may include identification information of the multicast service, context information of the multicast session, address information of the multicast service, identification information of a PDU session associated with the multicast session, and service data flow (service data) of the multicast service.
  • SDF packet filter identification rules
  • packet filter packet filter information of multicast service data
  • identification information of the multicast group corresponding to the multicast service such as the temporary mobile group identifier of the multicast group (temporary mobile group identifier, TMGI), multicast/broadcast service session ID (multicast/broadcast service session ID), multicast broadcast service session ID (MBS session ID), multicast session ID (multicast session ID), application server that provides multicast service data (such as AF) Internet protocol (internet protocol, IP) address, service identifier (service identifier, service ID) of multicast service, source specific IP multicast address (source specific IP multicast address), packet detection of multicast service
  • IP Internet protocol
  • service identifier service identifier, service ID
  • source specific IP multicast address source specific IP multicast address
  • PDR packet detection of multicast service
  • PDR packet detection rule
  • PDR is a collection of filters, each filter is a five-tuple, and each filter includes the multicast service Source address, destination address, source port number, destination port number, protocol number, and PDR are used to filter the data of the multicast service.
  • the identification information of the terminal may be used to identify the terminal, and the identification information of the terminal may be a subscription permanent identifier (SUPI) of the terminal, a subscription concealed identifier (SUCI) of the terminal, or a user concealed identifier (SUCI) of the terminal.
  • SUPI subscription permanent identifier
  • SUCI subscription concealed identifier
  • SUCI user concealed identifier
  • General public subscription identifier (generic public subscription identifier, GPSI), terminal 5G short temporary mobile subscriber identity (5G S-temporary mobile subscriber identity, 5G-S-TMSI), terminal 5G globally unique temporary identity (5G globally temporary identity , 5G-GUTI), terminal permanent equipment identifier (permanent equipment identifier, PEI), terminal Internet protocol (internet protocol, IP) address, terminal media access control (media access control, MAC) address, or terminal international Mobile subscriber identity (international mobile subscriber identity, IMSI), etc.
  • the terminal may include but not limited to the first terminal, the second terminal, the third terminal, etc. described in the following embodiments.
  • the PDU session of the terminal may be called (associated with) the multicast session, and the PDU session is associated with the multicast session.
  • the association between the PDU session and the multicast session can be recorded on network elements such as the terminal, the access network device, and the session management function network element corresponding to the terminal's PDU session.
  • the association relationship between the PDU session and the multicast session may include one or more of the following: 1), the identification information of the multicast session is stored in the session management context (session management context, SM context) of the PDU session.
  • the identification information of the SM context of the PDU session points to the multicast service, such as the identification information of the PDU session can include the identification (indentifier, ID) of the SM context of the PDU session, the ID of the SM context of the PDU session and the identification of the multicast session
  • ID identification
  • the information is correspondingly stored;
  • the context of the multicast service such as the multicast broadcast service session context (MBS session context), or the multicast broadcast group context (MBS group context), or the multicast broadcast service context (MBS service context)
  • the identification information of the PDU session associated with the multicast session or the identification information of the terminal joining the multicast session is stored in the multicast broadcast context (MBS context).
  • the session management function network element corresponding to the terminal's PDU session may be a session management function network element that establishes, manages, and maintains (eg, modifies, releases) the terminal's PDU session.
  • SM context session management context
  • the state of the PDU session of the terminal may be described as the user plane state of the PDU session of the terminal, etc., and the state of the PDU session of the terminal may include an active state (active or activated or activated), or a deactivated state (deactivate or inactive or deactivated). If the PDU session is deactivated, the N3 tunnel and/or data radio bearer (DRB) (or called radio bearer, RB) resources corresponding to the PDU session are released/unavailable . If the PDU session is active, the N3 tunnel and DRB resources corresponding to the PDU session exist/are available.
  • DRB data radio bearer
  • a PDU session of a terminal may correspond to a network element with a session management function, and be managed by the network element with a session management function.
  • Different PDU sessions of a terminal may correspond to network elements with a different session management function, or may correspond to the same session management function.
  • the PDU sessions of different terminals may correspond to the same network element with the session management function.
  • CM-IDLE connection management-idle
  • the terminal and the access The NAS signaling connection with the mobility management function network element is disconnected, and the terminal cannot send NAS signaling to the access and mobility management function network element.
  • the terminal can be in the connection management-connected (CM-connceted) state.
  • the terminal is in the CM-IDLE state, if the terminal is a terminal joining a multicast session, when the multicast session is activated, if the terminal in the CM-IDLE state is not paged, it will affect the ability of the terminal in the CM-IDLE state to receive multicast services. data.
  • the terminal can be changed from the CM-IDLE state to the connection management-connected (CM-connceted) state, and a NAS signaling connection is established with the access and mobility management function network element, and then, The first session management function network element notifies the access network device to add the terminal to the multicast session, so as to ensure that the terminal receives data of the multicast service through the multicast session.
  • the access and mobility management function network element corresponding to the terminal may be an access and mobility management function network element that can provide NAS signaling services for the terminal, and the CM state of the terminal may be determined by the access and mobility management function network element corresponding to the terminal.
  • Maintenance of network elements with performance management functions, for example, the CM state of the terminal can be stored in the context of the terminal (such as UE context) in the network element with access and mobility management functions. For other network elements, it is impossible to perceive/maintain the CM status of the terminal.
  • the session management function network element corresponding to the PDU session of the terminal determines that the PDU session is in the deactivated state
  • the session management function network element can only know the status of the PDU session, but cannot determine the CM status of the terminal Is it CM-IDLE state or CM-CONNECTED state.
  • the terminal can join the multicast session through the PDU session, that is, the PDU session of the terminal is associated with the multicast session.
  • the CM state of the terminal may be CM-IDLE state or CM-CONNECTED.
  • the CM state of the terminal is CM-CONNECTED state.
  • UE1-UE4 joining the same multicast session as an example.
  • UE1 joins the multicast session through UE1's PDU session X
  • UE2 joins the multicast session through UE2's PDU session Y
  • UE3 joins the multicast session through UE3's PDU session Z joins the multicast session
  • UE4 joins the multicast session through UE4's PDU session H.
  • PDU sessions correspond to the same session management function network element.
  • the session management The functional network element stores the association relationship between the multicast session and the PDU session, and the association relationship includes UE1, UE2, UE3 and UE4 in the multicast service context.
  • the state of PDU session X, PDU session Y, PDU session Z, and PDU session H is maintained in the session management network element.
  • the state of PDU session X in the SM context of PDU session The state of PDU session Y in the context is deactivated, the state of PDU session Z in the SM context of PDU session Z is deactivated, and the state of PDU session H in the SM context of PDU session H is activated.
  • UE1-UE3 are in the CM-IDLE state, and UE4 is in the CM-CONNECTED state. That is, it can be seen from Figure 1 that PDU session X, PDU session Y, and PDU session Z are in the deactivated state, UE1, UE2, and UE3 corresponding to PDU session X, PDU session Y, and PDU session Z are in the CM-IDLE state, and PDU session H is in the CM-IDLE state. In the activated state, the UE4 corresponding to the PDU session H is in the CM-CONNECTED state.
  • the terminal joins the multicast session through the first PDU session of the terminal, and the first PDU session is in the deactivated state, the terminal may be in CM-IDLE state or CM-CONNECTED state.
  • the first session management function network element can trigger The network element with the access and mobility management function pages the terminal that joins the multicast session and is in the CM-IDLE state back to the CM-CONNECTED state.
  • the context of the terminal in the access and mobility management function network element or the context of the PDU session associated with the multicast session of the terminal has Information about the multicast session needs to be released.
  • the access and mobility management function network element and The first session management function network element cannot communicate with the terminal on the N2 interface, so it is necessary to paging the terminal that joined the multicast session and is in the CM-IDLE state back to the CM-CONNECTED state to further release and communicate with the group through the N2 interface.
  • Information about the broadcast session is necessary to paging the terminal that joined the multicast session and is in the CM-IDLE state back to the CM-CONNECTED state to further release and communicate with the group through the N2 interface.
  • the first session management function network element triggering the access and mobility management function network element to paging the terminal that joined the multicast session and is in the CM-IDLE state back to the CM-CONNECTED state may include: when the multicast session When the multicast session is activated or released, if there is a PDU session in the deactivated state among the PDU sessions associated with the multicast session, the first session management function network element sends the access and mobility management function network element An instruction is sent to instruct the access and mobility management functional network element to page the terminal that joins the multicast session and is in the CM-IDLE state back to the CM-CONNECTED state.
  • the access and mobility management function network element needs to perform multiple times of paging the terminal in the CM-IDLE state back to the CM-CONNECTED state. process, the signaling overhead increases. Therefore, for a terminal that joins a multicast session and is in the CM-IDLE state, when the multicast session is (re)activated or the multicast session is released, how to optimize signaling is an urgent problem to be solved.
  • an embodiment of the present application provides a communication method, which may include: the first session management function network element receives a message from The first message of the second session management function network element (such as multicast broadcast service session activation (MBS session activation or session activation (session activation) or multicast session activation (multicast session activation) or multicast broadcast service session release (MBS session) release) or session release (session release) or multicast session release (multicast session release)), the first message can be used to notify the activation of the multicast session/to notify the data of the multicast service to be sent/notify the multicast service The data has arrived/indicates the activation of the multicast session/indicates that the multicast session needs to be reactivated or the first message is used to notify the release of the multicast session; the first session management function network element sends the first information to the access and mobility management function network element , the first
  • the communication system may include multiple terminals (such as the first terminal, etc.), access network equipment, access and mobile network element with a sex management function, a network element with a second session management function, and a network element with a first session management function.
  • the communication system shown in FIG. 2 may further include a first user plane functional network element, a second user plane functional network element, a policy control network element, a network storage network element, and a data network (data network, DN), and the DN may include Application server (application server, AS) and so on.
  • the first user plane function network element, the second session management function network element, the second user plane function network element, and the DN are optional network elements in this application.
  • multiple terminals can form a multicast group, and multiple terminals can simultaneously receive the same data, that is, the data of the multicast service.
  • the first user plane functional network element can be used to transmit unicast data (unicast data), and can also be used to transmit multicast service data
  • the second user plane functional network element can be used to transmit multicast service data (multicast data)
  • the unicast data may be data sent to a specific terminal or user
  • the data of the multicast service may be data sent to a multicast group.
  • the first session management function network element may be a session management function network element that manages PDUs, and may be called a unicast session management function network element
  • the second session management function network element may be a session management function network element that manages multicast services, and may be It is called the multicast session management function network element.
  • the network elements or devices involved in the architecture shown in FIG. 2 are introduced below.
  • a terminal may be called a terminal equipment (terminal equipment) or a user equipment (user equipment, UE) or a mobile station (mobile station, MS) or a mobile terminal (mobile terminal, MT), etc.
  • the terminal in Figure 1 can be a mobile phone, a tablet computer, or a computer with a wireless transceiver function, or a virtual reality (virtual reality, VR) terminal, an augmented reality (augmented reality, AR) terminal, an industrial Wireless terminals in control, wireless terminals in unmanned driving, wireless terminals in telemedicine, wireless terminals in smart grids, wireless terminals in smart cities, smart homes, vehicle terminals, etc.
  • VR virtual reality
  • AR augmented reality
  • 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 (access point, AP), base station (nodeB, NB), enhanced base station (enhance nodeB, eNB), next-generation base station (NR nodeB, gNB), transmission and reception point (transmission reception point, TRP), transmission point (transmission point, TP) or some other access node.
  • the access and mobility management functional network element is mainly responsible for terminal access authentication, mobility management, and signaling interaction between various functional network elements, such as: user registration status, user connection status, user registration and network access , tracking area update, cell handover user authentication and key security management.
  • the session management function network element is mainly used to implement the user plane transmission logical channel, such as session management functions such as the establishment, release and modification of packet data unit (packet data unit, PDU) sessions or multicast sessions.
  • session management functions such as the establishment, release and modification of packet data unit (packet data unit, PDU) sessions or multicast sessions.
  • the user plane functional network element can be used as the anchor point on the user plane transmission logic channel, and is used 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), in which the channel The upper layer forwards the data packets between the terminal and the DN, and is responsible for data packet filtering, data forwarding, rate control, and billing information generation for the terminal.
  • the policy control network element can be used to provide policies to the access and mobility management function network element and the session management function network element, such as: quality of service (quality of service) policy, slice selection policy, and so on.
  • quality of service quality of service
  • slice selection policy slice selection policy
  • the network storage network element can be used to store user data, such as: user subscription information, authentication or authorization data, etc.
  • the network storage network element may be a unified data management network element (unified data management, UDM), a network storage function (network repository function, NRF) or a unified database (unified data repository, UDR), etc.
  • DN is an operator network that can provide users with data transmission services, such as: an operator network that can provide users with IP multimedia services (IP multi-media service, IMS).
  • IP multimedia services IP multi-media service, IMS.
  • An application server (or called application function (AF)) may be deployed in the DN, and the application server may provide data transmission services to users.
  • AF application function
  • FIG. 2 is only an exemplary architecture diagram.
  • the system may also include other functional network elements, such as: operation and management (operation and management, O&M) network elements, etc.
  • O&M operation and management
  • This embodiment of the present application does not limit it.
  • the name of each device in Figure 2 is not limited.
  • each device can also be named other names, such as replacing it with the name of a network element with the same or similar functions, there is no limit.
  • the system shown in Figure 2 may be a third generation partnership project (3rd generation partnership project, 3GPP) communication system, such as a 4th generation (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 interface (new radio, NR) system, a next generation communication system, etc., or a non-3GPP communication system, without limitation.
  • 3GPP third generation partnership project
  • the network element or entity corresponding to the first session management function network element above may be a session in the 5G communication system Management function (session management function, SMF), the network element or entity corresponding to the second session management function network element above can be the multicast/broadcast session management function (multicast broadcast session management function, MB-SMF) in the 5G communication system ), the network element or entity corresponding to the second user plane function network element above may be the user plane function (multicast broadcast user plane function, MB-UPF) in the 5G communication system.
  • SMF session management function
  • MB-SMF multicast broadcast session management function
  • MB-UPF user plane function
  • the network element or entity corresponding to the access network device may be a radio access network (radio access network, RAN) in the 5G communication system
  • the network element or entity corresponding to the access and mobility management function network element may be a radio access network (RAN) in the 5G communication system
  • the access and mobility management function (access and mobility management function, AMF) and the policy control function of the 5G communication system may be the policy control function (policy control function, PCF).
  • the SMF and the MB-SMF may be co-established, or deployed independently, without limitation.
  • UPF and MB-UPF can be co-located, or deployed independently, without limitation.
  • the system shown in Figure 3b may also include a multicast/broadcast service transport function (multicast/broadcast service transport function, MBSTF), multicast broadcast service function (multicast broadcast MBSF).
  • MBSTF may have the function of UPF for transmitting multicast service data.
  • MBSF can have MB-SMF functions, such as establishing/managing multicast sessions corresponding to multicast services, etc.; MBSF can also support intercommunication with MBMS of LTE, etc.
  • the multicast service data can be transmitted between the access network device and the user plane functional network element in the 5G core network independent multicast/broadcast service traffic transmission mode.
  • the data of the multicast service can be transmitted in the mode of 5GC shared MBS traffic delivery (5GC shared MBS traffic delivery).
  • the data of the multicast service directly reaches the RAN through the MB-UPF and the N3 tunnel between the MB-UPF and the RAN, and the RAN can be point-to-point (point to point) , PTP) or point to multi-point (point to multi-point, PTM) way to send to the terminals joining the multicast session.
  • the multicast service data passes through MB-UPF to UPF, and then reaches RAN through the N3 tunnel between UPF and RAN (such as the PDU session of the terminal), and RAN sends point-to-point to terminal.
  • Access network equipment does not support the multicast function. It can be understood that the access network equipment does not support the transmission of multicast service data in the form of 5GC shared MBS traffic delivery (5GC shared MBS traffic delivery), that is, only supports 5G core network individual multicast/broadcast service traffic transmission (5GC Individual MBS traffic delivery) mode transmits multicast service data, that is, multicast service data is sent to the terminal through the associated PDU session of the terminal joining the multicast session.
  • 5GC shared MBS traffic delivery 5GC shared MBS traffic delivery
  • 5GC shared MBS traffic delivery that is, only supports 5G core network individual multicast/broadcast service traffic transmission
  • 5GC Individual MBS traffic delivery transmits multicast service data, that is, multicast service data is sent to the terminal through the associated PDU session of the terminal joining the multicast session.
  • the data of the multicast service reaches the access network device (for example, RAN), it passes through the service data adaptation protocol (service data adaptation protocol, SDAP) layer of the RAN, and the packet data convergence protocol (packet data convergence protocol, PDCP) Layer, radio link control (radio link control, RLC) layer, media access control (media access control, MAC) layer, physical (physical, PHY) layer processing, sent to each terminal receiving multicast service data .
  • service data adaptation protocol service data adaptation protocol, SDAP
  • packet data convergence protocol packet data convergence protocol
  • RLC radio link control
  • media access control media access control
  • MAC physical (physical, PHY) layer processing
  • the SMF and the MB-SMF may be co-established, or deployed independently, without limitation.
  • UPF and MB-UPF can be co-located, or deployed independently, without limitation.
  • the session management function network element, the access network device, and the access and mobility management function 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.
  • the embodiment of the application does not specifically limit this.
  • the related functions of the session management function network element, the user plane function network element, the access network device, and the access and mobility management function network element in the embodiment of the present application may be implemented by one device, or by multiple
  • the common realization of the devices may also be realized by one or more functional modules in one device, which is not specifically limited in this embodiment of the present application. It can be understood that the above function can be a network element in a hardware device, or a software function running on dedicated hardware, or a combination of hardware and software, or a virtual function.
  • each device shown in Figure 2 such as the first session management function network element, the access and mobility management function network element, etc., can adopt the composition structure shown in Figure 4, or include the part.
  • FIG. 4 is a schematic diagram of a composition of a communication device 400 provided by an embodiment of the present application.
  • the communication device 400 may include a processor 401 and a memory 404 . Further, the communication device 400 may further include a communication line 402 and a communication interface 403 . Wherein, 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 (programmable logic device, PLD) or any combination thereof.
  • the processor 401 may also be other devices with processing functions, such as circuits, devices or software modules, without limitation.
  • the communication line 402 is used to transmit information between the components included in the communication device 400 .
  • the communication interface 403 is used for communicating with other devices or other communication networks.
  • the other communication network may be an Ethernet, a radio access network (radio access network, RAN), a wireless local area network (wireless local area networks, WLAN), and the like.
  • the communication interface 403 may be a module, a circuit, a transceiver or any device capable of realizing communication.
  • the memory 404 is used for storing instructions.
  • the instruction may be a computer program.
  • the memory 404 can be a read-only memory (read-only memory, ROM) or other types of static storage devices that can store static information and/or instructions, and can also be a random access memory (random access memory, RAM) or a Other types of dynamic storage devices that store information and/or instructions can also be electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD- ROM) or other optical disc storage, optical disc storage (including compact discs, laser discs, compact discs, digital versatile discs, Blu-ray discs), magnetic disc storage media, and other magnetic storage devices, without limitation.
  • EEPROM electrically erasable programmable read-only memory
  • CD- ROM compact disc read-only memory
  • optical disc storage including compact discs, laser discs, compact discs, digital versatile discs, Blu-ray discs
  • magnetic disc 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 can be used to store instructions or program codes or some data, etc.
  • the memory 404 may be located in the communication device 400 or outside the communication device 400, without limitation.
  • the processor 401 is configured to execute instructions stored in the memory 404, so as to implement the communication method provided by the following embodiments of the present application. For example, when the communication device 400 is the first session management function network element or a chip or system-on-chip in the first session management function network element, the processor 401 executes the instructions stored in the memory 404 to implement the following embodiments of the present application. Steps performed by the first session management function network element. For another example, when the communication device 400 is an access network device or a chip or system-on-a-chip in the access network device, the processor 401 may execute instructions stored in the memory 404 to implement the access network device in the following embodiments of the present application. steps performed.
  • the processor 401 may include one or more CPUs, such as CPU0 and CPU1 in FIG. 4 .
  • the communications apparatus 400 includes multiple processors, for example, in addition to the processor 401 in FIG. 4 , it may further include a processor 407 .
  • 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 and a speaker (speaker).
  • the communication device 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 having a structure similar to that shown in FIG. 4 .
  • the composition structure shown in FIG. 4 does not constitute a limitation to the communication device.
  • the communication device may include more or less components than those shown in the illustration, or combine certain components , or different component arrangements.
  • system-on-a-chip may be composed of chips, or may include chips and other discrete devices.
  • each network element in the following embodiments may have the components shown in FIG. 4 , which will not be described in detail.
  • the actions and terms involved in the various embodiments of the present application may refer to each other without limitation.
  • the names of messages exchanged between various devices or the names of parameters in messages are just examples, and other names may also be used in specific implementations, which are not limited.
  • the multicast in the embodiment of the present application may be replaced by terms such as broadcast, multicast, multicast communication, multicast/broadcast, or multicast/broadcast.
  • the determination in the embodiment of the present application can also be understood as creating or generating, and the "comprising" in the embodiment of the present application can also be understood as “carrying” or “comprising”, etc. The embodiment does not specifically limit this.
  • FIG. 5 is a communication method provided by an embodiment of the present application, and the method can be used to optimize the paging process for terminals joining the multicast session when the multicast session is activated or released. As shown in Figure 5, the method may include:
  • the second session management function network element determines to activate the multicast session or determines to activate the multicast session, or the second session management function network element determines to release the multicast session or determines to release the multicast session.
  • the second session management function network element may be the second session management function network element in Fig. 2, or the MB-SMF in Fig. 3a or Fig. 3b.
  • the second session management function network element may correspond to the multicast session, and the second session management function network element may manage the multicast session, for example, the second session management function network element may establish, modify/update or release the multicast session, etc., the second The network element with the session management function can also save the multicast QoS information corresponding to the multicast session (or called the QoS information related to the multicast service, etc.), save the context of the multicast session, and the like.
  • the multicast session may be a transmission channel for transmitting multicast service data, and the multicast session includes a transmission tunnel from MB-UPF to an access network device.
  • the multicast session activation or activation of the multicast session in S501 is performed, the multicast session is in the deactivated state, for example, the state of the multicast session in the multicast session context of the second session management function network element is the deactivated state.
  • the multicast session release of S501 is performed or the multicast session is released, the multicast session may be in an activated state or a deactivated state.
  • the multicast service may be a type of service oriented to a multicast group or multiple terminals, and the data receiving objects of the multicast service may be a group of terminals authorized to receive the data.
  • the multicast service can be an order for a convoy issued by the same command center or a TV program for multiple viewers.
  • the multicast session activation or the multicast session needs to be activated may be replaced with the description that the data of the multicast service has arrived, or the data of the multicast service is to be sent, or the resources of the multicast session need to be activated, and so on.
  • the release of the multicast session or the need to release the multicast session can be replaced with the description that the multicast service needs to be released and so on.
  • the second session management function network element when the second session management function network element receives a notification of multicast broadcast session activation (MBS session activation or session activation or multicast session activation) from AF/AS or MBSF or NEF, the second session management function network The element determines that the multicast session is active. Or, the MB-UPF detects the arrival of the data of the multicast service, and the MB-UPF notifies the second session management function network element that the multicast session is activated, and the second session management function network element receives the notification from the MB-UPF, and determines that the multicast session is activated .
  • MMS session activation or session activation or multicast session activation multicast broadcast session activation
  • the second session management function network element when the second session management function network element receives a notification (MBS session release or session release or multicast session release) from AF/AS or MBSF or NEF multicast broadcast session release, the second session management function network Element determines that the multicast session needs to be released. Alternatively, the second session management functional network element determines to release the multicast session after determining to remove the multicast session configuration (removal of MBS session configuration).
  • S502 The second network element with the session management function sends the first message to the first network element with the session management function.
  • the first network element with the session management function receives the first message from the second network element with the session management function.
  • the first session management function network element may be the SMF corresponding to the terminal's PDU session, and the terminal's PDU session is associated with the multicast session, that is, the first session management function network element may manage (establish, modify or release) the multicast session.
  • the session management function network element of the session-associated PDU session, the first session management function network element may store the context of the PDU session and the like.
  • the terminal corresponding to the PDU session may be a terminal joining the multicast session, and the user using the terminal may be a member of the multicast group corresponding to the multicast session.
  • the first message may be used to notify the activation of the multicast session, or to notify the data of the multicast service to be sent, or to notify that the data of the multicast service has arrived, or to indicate the activation of the multicast session, or to use It is used to indicate that the multicast session needs to be reactivated, or to indicate/notify the reactivation of the multicast session, etc.
  • the first message may include identification information of the multicast session.
  • the first message may be an N16mb message.
  • the first message can be a request for multicast session activation, such as a multicast broadcast service activation request (MBS activation request), or a notification for multicast session activation, such as a multicast broadcast service activation notification (MBS session activation notification) or a multicast Broadcast service session activation (MBS session activation) or session activation (session activation) or multicast session activation (multicast session activation), etc.
  • the first message may directly indicate/notify the activation of the multicast session, for example, the first message may carry an information element/indication/notification indicating activation Multicast session.
  • the first message may indirectly indicate the activation of the multicast session, such as the first message may be used to indicate/notify the start/start of the multicast session, and the first message is MBS session start/session start or a multicast broadcast service session Activation (MBS session activation) or multicast session activation (multicast session activation) or multicast broadcast service session activation (MBS session activation) or multicast session activation (multicast session activation) or session activation (session activation), or the first message It is used to indicate that the MB-UPF has detected the data of the multicast service or the data of the multicast service has arrived at the MB-UPF or the data of the multicast service is about to be transmitted or the data of the multicast service is to be transmitted.
  • MBS session activation multicast broadcast service session Activation
  • MBS session activation multicast session activation
  • multicast session activation multicast broadcast service session activation
  • multicast session activation multicast session activation
  • session activation multicast session activation
  • the first message may be used to notify the release of the multicast session, or to indicate/notify the release of the multicast session, and the like.
  • the first message may include identification information of the multicast session.
  • the first message may be an N16mb message.
  • the first message can be a request (MBS session release request) for multicast session release, or a notification (MBS session release) for multicast session release or session release (session release) or multicast session release (multicast session release).
  • the second session management function network element may send the first message to the first session management function network element according to the identification information of the first session management function network element.
  • the first session management function network element extracts the multicast QoS information corresponding to the multicast session from the second session management function network element, it sends a subscription request carrying the identification information of the multicast session to the second session management function network element , request to subscribe to the notification of multicast session activation (such as MBS session activation notification or MBS session activation or session activation or multicast session activation), or request to subscribe to the multicast session release (such as multicast broadcast session release (MBS session release) or session release (session release) or multicast session release (multicast session release), subsequently, when the second session management function network element determines that the multicast session is activated or the multicast session is released, the second session management function network element can be based on the first The subscription request of the session management function network element sends a first message to the first session management function network element.
  • the identification information of the first session management function network element may be used to identify the first session management function network element.
  • the identification information of the first session management function network element may be stored in the second session management function network element. For example, when a terminal joins a multicast session through a PDU session in progress, the first session management function network element sends a message to the second session management function network element. When the element extracts the multicast QoS information, the second session management function network element correspondingly stores the identification information of the first session management function network element and the identification information of the multicast session. Or the second network element with the session management function obtains the identification information of the first network element with the session management function from other network elements.
  • the first network element with the session management function may send the identification information of the multicast session to the first network element, and the first network element
  • the element receives the identification information of the multicast session, uses the identification information of the multicast service as an index to query the first multicast correspondence relationship, finds the identification information of the first session management function network element corresponding to the identification information of the multicast session, and sends the identification information to the second session
  • the management function network element sends the identification information of the first session management function network element.
  • the first network element may be NRF or UDM or UDR or PCF, and may also be other network elements capable of selecting MB-SMF, without limitation.
  • the first correspondence may include a correspondence between identification information of the multicast session and identification information of the first session management function network element, and the first correspondence may be pre-stored in the first network element.
  • the first session management functional network element determines, according to the first message, that a PDU session in a deactivated state among PDU sessions associated with the multicast session meets a preset condition.
  • the PDU session associated with the multicast session may be a PDU session for a terminal to join the multicast session.
  • the preset condition may include that the ratio of the total number of PDU sessions in the deactivated state to the total number of PDU sessions associated with the multicast session among the PDU sessions associated with the multicast session reaches a preset ratio, or the preset condition includes The number of deactivated PDU sessions in the PDU session reaches the preset number threshold, or the number of terminals corresponding to the PDU session associated with the multicast session reaches the preset number threshold, or the number of terminals corresponding to the multicast session reaches the preset number
  • the terminal corresponding to the multicast session may include a terminal that is provided with a PDU session management service by the first session management functional network element among the terminals joining the multicast session.
  • the preset number threshold may be greater than or equal to 1.
  • the preset number threshold may be 1, or 2, or a value greater than 2.
  • the first session management function network element may use the identification information of the multicast session included in the first message as an index to find the context of the multicast service corresponding to the multicast session, and according to the context of the multicast service included in the The identification information of the terminal determines the terminal joining the multicast session. Further, the first session management function network element can check the context of the PDU session of these terminals, if the context of the PDU session includes the identification information of the multicast session, it is determined that the PDU session is associated with the multicast session, and at the same time according to the PDU session The user plane state (upCnxState) information of the PDU session included in the context determines whether the PDU session is in the deactivated state or the activated state.
  • upCnxState upCnxState
  • S503 is an optional step, and S501, S502, S504, and S505 can be executed to optimize the paging process, or S501-S505 can be executed to optimize the paging process. limit.
  • the first session management functional network element sends the first information to the access and mobility management functional network element according to the first message.
  • the access and mobility management functional network element receives the first information from the first session management functional network element.
  • the access and mobility management function network element may be the access and mobility management function network element corresponding to the PDU session associated with the multicast session, or provide NAS signaling for the terminal corresponding to the PDU session associated with the multicast session
  • the network element of the service is used as the termination point of the non-access stratum (NAS) signaling of the terminal, and is used to manage/process the NAS signaling of the terminal, such as the access and mobility management function network
  • the element may be responsible for encrypting and integrity protecting the terminal's NAS signaling messages.
  • the first information may include identification information and/or indication information of the multicast session.
  • the indication information can be used to indicate group paging (group paging) or to indicate (perform) to perform group paging or perform group paging, etc., or to indicate group paging of terminals corresponding to the multicast session or to indicate the The corresponding terminal performs group paging or instructs the terminal corresponding to the multicast session to perform group paging and the like.
  • the indication information may include first indication information or second indication information. In a case where the first information includes identification information of the multicast session and indication information, group paging may be explicitly indicated through the indication information. When the first information includes identification information of the multicast session or identification information of the multicast session, group paging may be indicated implicitly, for example, group paging may be indicated through the information type of the first information.
  • the first indication information may be used to indicate that the terminal corresponding to the multicast session is paging in a group paging manner, and the terminal corresponding to the multicast session may be the terminal corresponding to the multicast session managed by the first session.
  • the first indication information may include identification information of a terminal corresponding to the multicast session. For example, in S503, after the first session management function network element checks the context of the multicast service and determines the terminals joining the multicast session, for example, if it is determined that the number of terminals joining the multicast session is greater than or equal to 1, then the number of terminals joining the multicast session
  • the identification information is carried in the first indication information.
  • the first information carrying the identification information of the multicast session and the first indication information may be carried in one N11 message.
  • the first indication information includes terminal identification information may be replaced by describing that the first indication information includes a UE list, and the UE list may include identification information of terminals joining the multicast session.
  • the second indication information may be used to indicate that the terminal corresponding to the PDU session in the deactivated state is paged in a group paging manner.
  • the second indication information carries identification information of the terminal corresponding to the associated PDU session in the deactivated state. For example, in S503, after the first session management function network element determines the associated PDU sessions in the deactivated state among the PDU sessions associated with the multicast session, if the associated PDU sessions in the deactivated state are greater than or equal to 1, these are deactivated The identification information of the terminal corresponding to the active PDU session is carried in the second indication information.
  • the first information carrying the second indication information and the identification information of the multicast session may be carried in one N11 message.
  • the second indication information includes the identification information of the terminal corresponding to the associated PDU session in the deactivated state. The identification information of the terminal corresponding to the PDU session.
  • the second indication information does not carry the identification information of the terminal corresponding to the PDU session in the deactivated state, and only indicates the access and mobility management function network element group paging.
  • the access and mobility management function network element can know which terminals corresponding to the PDU sessions in the deactivated state perform group paging in the following manner: the first session management function network element determines that the PDU session associated with the multicast session After the PDU sessions in the deactivated state meet the preset conditions, for example, after the number of PDU sessions in the deactivated state is greater than or equal to 1, the first session management function network element sends the first session management function to the access and mobility management function network element.
  • the control plane signaling message corresponding to the PDU session in the deactivated state in the network element corresponds to one PDU session.
  • the control plane signaling message can be the service interface (Namf) between SMF and AMF_communication_ N1N2 message transfer (Namf_Communication_N1N2Message Transfer), the control plane signaling message can be used to instruct the network element of the access and mobility management function to join the terminal corresponding to the PDU session into the multicast session or to indicate that the network element of the access and mobility management function
  • the terminal corresponding to the session is in the CM-IDLE state, page the terminal or instruct the access and mobility management functional network element to send the QoS configuration information corresponding to the PDU session to the access network device.
  • the access and mobility management function network element since the PDU session corresponds to the terminal, when the access and mobility management function network element receives the control plane signaling message corresponding to the PDU session from the first session management function network element, it can know which PDU session the control plane signaling message corresponds to , and then know which terminal the PDU session corresponds to from the context of the locally stored PDU session, and determine whether to add the terminal to the multicast session or to page the terminal when the terminal is in the CM-IDLE state.
  • the first information carrying the second indication information may include There is no restriction on the Nth control plane message among the N control plane messages or any one of 1-N control plane messages.
  • N control plane messages correspond to N deactivated PDU sessions one by one, or the first information is carried in an N11 message, and the N11 message may be sent after the first session management function network element sends N control plane messages send.
  • PDU session X there are four UEs joining the multicast session: UE1-UE4, and there are four PDU sessions associated with the multicast session: PDU session X, PDU session Y, PDU session Z, PDU session H, PDU session Session X corresponds to UE1, PDU session Y corresponds to UE2, PDU session Z corresponds to UE3, and PDU session H corresponds to UE4.
  • the first session management function network element can send the first information to the access and mobility management function network element ⁇ multicast session identification information of the multicast session, UE1-UE4 ⁇ , or the first session management function network element may send the first information ⁇ identification information of the multicast session, UE1-UE3 ⁇ , or the first session management function network element to the access and mobility management function network element
  • the functional network element can send the control plane signaling message X corresponding to PDU session X, the control plane signaling message Y corresponding to PDU session Y, and the control plane signaling message Z corresponding to PDU session Z to the access and mobility management functional network element , where if the control plane signaling message Z is the last control plane signaling message sent, the control plane signaling message Z may carry the second indication information and the identification information of the multicast session, indicating group paging, or the second The indication information may also be carried
  • the access and mobility management function network element performs group paging according to the first information, or alternatively described as the access and mobility management function network element performs/performs group paging according to the first information.
  • the network element with the access and mobility management function may determine that it is in the CM-IDLE state according to the identification information of the terminal included in the first indication information if the first information includes the first indication information.
  • the access and mobility management function network element determines the group paging area according to the registration area of the terminal in the CM-IDLE state.
  • the group paging area includes the union of the registration areas of the terminal in the CM-IDLE state.
  • the group paging area The call area does not include the overlapping part of the terminal registration area in CM-IDLE state.
  • the access and mobility management function network element sends a paging message to the group paging area, and the paging message carries the identification information of the multicast session.
  • the access and mobility management function network element receives the first information, if the first information includes the second indication information, and the second indication information includes the associated PDU session in the deactivated state
  • the identification information of the terminal determines the terminal in the CM-IDLE state, or, if the first information includes the second indication information, and the second indication information does not include the identification information of the terminal corresponding to the associated PDU session in the deactivated state, then
  • the network element with the mobility management function can determine the identification information of the terminal through the control plane signaling message corresponding to the PDU session associated with the deactivated state, and then determine whether the terminal is in the CM-IDLE state according to the identification information of the terminal.
  • the access and mobility management function network element determines the group paging area according to the registration area of the terminal in the CM-IDLE state, the group paging area includes the union of the registration areas of the terminal in the CM-IDLE state, and the group paging area The call area does not include the overlapping part of the terminal registration area in CM-IDLE state.
  • the access and mobility management function network element sends a paging message to the group paging area, and the paging message carries the identification information of the multicast session.
  • the paging message carrying the identification information of the multicast session may be called a group paging message.
  • the registration area of the terminal may be pre-configured to the terminal by an access and mobility management function network element that provides NAS signaling services for the terminal. For example, when the terminal sends the access and mobility management After the functional network element completes the registration, the access and mobility management functional network element configures the terminal.
  • the information used to indicate the registration area of the terminal (in this application may be referred to as the registration area information of the terminal) is stored on the access and mobility management function network element, for example, the registration area information of the terminal can be stored in the access and mobility management
  • the context of the terminal may also include identification information of the terminal and other information.
  • the registration area of the terminal may be an area where the terminal is registered and can provide network services for the terminal.
  • the registration area of the terminal may include one or more access network devices, without limitation.
  • the access network devices included in the registration area of the terminal may or may not support the multicast function, and there is no restriction.
  • the access and mobility management function can initiate group paging only in the overlapping area of a terminal, instead of repeatedly initiating group paging in the overlapping area of each terminal's registration area.
  • the terminals in the CM-IDLE state include the first terminal and the second terminal, the registration area of the first terminal overlaps with the registration area of the second terminal, and the access and mobility management function network element can
  • the paging message is sent in the registration area of a terminal, and the paging message is sent in other areas except the overlapping area in the registration area of the second terminal, so that the access and mobility management function network element does not need to join the multicast session
  • the overlapping area of the registration area of each terminal in the CM-IDLE state repeatedly initiates group paging, so as to save signaling overhead.
  • the first session management function network element can send indication information to the access and mobility management function network element, Instruct the access and mobility management function network element to perform/execute group paging for the terminal corresponding to the multicast session, so as to optimize the paging area of the terminal corresponding to the multicast session, and not to repeatedly send paging messages in overlapping areas, so as to optimize paging
  • the process reduces signaling overhead caused by paging terminals in the multicast group.
  • the CM state of the terminal is managed by the network element with the access and mobility management function, other network elements will not manage the CM state of the terminal, that is, for other network elements, if the access and mobility management function If the network element does not notify, the CM status of the terminal will not be obtained.
  • the CM state of the terminal is CM-CONNECTED state
  • the terminal can receive data normally, for example, receive data of the multicast service through the radio bearer configured for the terminal to transmit the data of the multicast service.
  • the embodiment of the present application provides the communication method shown in FIG. 6 .
  • FIG. 6 is a communication method provided by the embodiment of the present application. As shown in FIG. 6, it may include:
  • the first session management functional network element sends a second message to the access and mobility management functional network element.
  • the access and mobility management functional network element receives the second message from the first session management functional network element.
  • the first session management function network element may be used to manage the PDU session associated with the multicast session in the PDU session of the first terminal.
  • the first session management function network element may be a session management function network element capable of managing the PDU session of the first terminal selected from a plurality of session management function network elements.
  • the first session management network element may be the first session management network element in FIG. 2 or the SMF in FIG. 3a.
  • the first session management function network element can manage the PDU session of the terminal.
  • the access and mobility management function network element can correspond to the terminal, and is the AMF that provides NAS signaling service for the terminal.
  • the second message may be used for the access and mobility management functional network element to indicate/notify the first session management functional network element of the terminal in the CM-CONNECTED state.
  • the second message may be a subscription request, and the subscription request may be used to request to notify the first session management function network element of the terminal in the CM-CONNECTED state.
  • the terminal may be a terminal that has joined (joined) (or has joined) a multicast session
  • the second message may include identification information of the multicast session
  • the second message may be alternatively described as triggering the access and mobility management function network element to Among the terminals joining the multicast session, the terminal in the CM-CONNECTED state indicates/notifies the first session management function network element, for example, the access and mobility management function network element sends a message to the first session management function network element to indicate the The third message that the terminal is in the CM-CONNECTED state.
  • the network element with the access and mobility management function when the network element with the access and mobility management function pages a terminal that joins the multicast session and is in the CM-IDLE state, some of the network elements with the access and mobility management function may page in the CM-IDLE state
  • the terminal may not page some of the terminals in the CM-IDLE state. In this scenario, all the terminals in the CM-IDLE state will not be paged, and they will still be in the CM-IDLE state, which cannot guarantee to join the multicast session.
  • the terminal normally receives the data of the multicast service.
  • the second message can also be used/indicate that the access and mobility management function network element paging (immediately paging or page immediately or immediately page or paging or may page) has joined the multicast A terminal in the session and in the CM-IDLE state, that is, a terminal in the CM-IDLE state that instructs the access and mobility management function network element to paging (it can be immediately paging or may paging, etc.) to join the multicast session , to avoid the problem of not paging the terminal that joins the multicast session and is in the CM-IDLE state, and to ensure that the terminal that joins the multicast session normally receives data of the multicast service.
  • the access and mobility management function network element paging immediate or immediately or immediately page or paging or may page
  • the second message may include identification information of terminals that have joined the multicast session.
  • the second message may also include identification information of the multicast session.
  • the second message includes the identification information of the terminals that have joined the multicast session. It can also be described as the second message includes a UE identification list (UE ID List or UE identification information (UE ID), and the UE list may include the terminals that have joined the multicast session.
  • the identification information of the terminal may include identification information of terminals that have joined the multicast session.
  • the second message when the second message is used to/indicate the access and mobility management function network element to page the terminal that has joined the multicast session and is in the CM-IDLE state, the second message may also include third indication information, The third indication information may be used to instruct the access and mobility management function network element to page (can be an immediately page) or a page (may page) when the terminal that has joined the multicast session is in the CM-IDLE state. ) or page) terminals that have joined the multicast session and are in CM-IDLE state.
  • the second message does not include the third indication information, and the second message itself has the function of instructing the access and mobility management function network element to page the terminal that has joined the multicast session and is in the CM-IDLE state, such as the second
  • the message type (information type)/message format of the message corresponds to the indication of paging the terminal that has joined the multicast session and is in the CM-IDLE state.
  • the second message may be a newly defined N11 message, or the second message may be an enable terminal reachability message (Namf_MT_EnableUEReachability or MBS_MT_Reachability, etc.), and this embodiment of the present application does not limit the signaling name of the second message.
  • the second message may be an enable terminal reachability request Namf_MT_EnableUEReachability request or MBS_MT_Reachability request or the like.
  • the second message may be Namf_EventExposure_Subscribe or the like.
  • paging a terminal that has joined a multicast session and is in the CM-IDLE state may refer to the network element with the access and mobility management function receiving the second message, according to the multicast session carried in the second message
  • the identification information of the terminal that joined the multicast session and the identification information of the terminal that joined the multicast session locates the terminal that has joined the multicast session and is in the CM-IDLE state; or locates the terminal that has joined the multicast session and is in the CM-IDLE state according to the identification information of the terminal that joined the multicast session - a terminal in the IDLE state, paging the terminal in the CM-IDLE state.
  • the first network element with the session management function when the first network element with the session management function receives the first message from the second network element with the session management function, the first network element with the session management function performs S601. Specifically, this process may refer to the description in the embodiment corresponding to FIG. 7 .
  • the access and mobility management functional network element sends a third message to the first session management functional network element according to the second message.
  • the first session management function network element receives the third message from the access and mobility management function network element.
  • the third message may include identification information of the first terminal and/or identification information of the multicast session.
  • the first terminal may be a terminal in CM-CONNECTED state, that is, the first terminal includes a terminal in CM-CONNECTED or a terminal in CM-CONNECTED and joining a multicast session.
  • the third message may be used to indicate the first terminal in the CM-CONNECTED state.
  • the CM state of the first terminal may be the CM-CONNECTED state or the CM-IDLE state.
  • the third message may be a reply message corresponding to the second message, or the third message may be a notification message, for example, if the first session management function network element subscribes to the access and mobility management function network element to The terminal in the CM-CONNECTED state notifies the first session management network element of an event, for example, the subscription message corresponding to the first session management function network element may be Namf_EventExposure_Subscribe), and the third message may be a notification corresponding to the subscription message A message, such as a notification message/reply message for Namf_EventExposure_Subscribe, for example, may be Namf_EventExposure_Notify.
  • the access and mobility management function network element sends the third message to the first session management function network element according to the second message may include: the access and mobility management function network element determines that the terminal is in CM-CONNECTED according to the second message state, sending a third message to the first session management function network element.
  • the CM state of the first terminal is CM-IDLE state
  • the access and mobility management function network element sends the third message to the first session management function network element according to the second message may include: receiving The access and mobility management function network element pages the terminals in the CM-IDLE state including the first terminal according to the second message, and if the access and mobility management function network element receives the service request from the first terminal, then Establishing a NAS signaling connection for the first terminal according to the service request of the first terminal, changing the first terminal from the CM-IDLE state to the CM-CONNECTED state, and sending a third message to the first session management function network element.
  • this process may refer to the description in S704-S706 in FIG. 7 below.
  • the CM state of the first terminal is the CM-CONNECTED state
  • the access and mobility management function network element sends the third message to the first session management function network element according to the second message may include: The access and mobility management function network element locates the first terminal among the terminals that have joined the multicast session to be in the CM-CONNECTED state according to the identification information of the multicast session carried in the second message and the identification information of the terminal joining the multicast session ; Or locate the first terminal that has joined the multicast session in the CM-CONNECTED state according to the identification information of the terminal that joined the multicast session, and send a third message to the first session management function network element. Specifically, refer to the description of S707 in FIG. 7 below for this process.
  • the access and mobility management functional network element may send the third message to the first session management functional network element according to the identification information of the first session management functional network element.
  • the identification information of the first session management function network element may be used to identify the first session management function network element.
  • the access and mobility management function network element may store the identification information (such as SMF ID) of the first session management function network element when the first terminal establishes the PDU session associated with the multicast session.
  • the terminals in the CM-IDLE state include the first terminal, after the access and mobility management function network element receives the second message,
  • the terminal in the CM-IDLE state may be paged according to the second message.
  • the access and mobility management function network element determines the terminal in the CM-IDLE state according to the second message; the access and mobility management function network element sends a paging message in the paging area of the terminal in the CM-IDLE state , the paging message includes identification information of the multicast session; the paging area of the terminal in the CM-IDLE state includes access network devices supporting multicast capabilities.
  • the method may also include:
  • the first session management function network element sends the second information to the access network device corresponding to the first terminal according to the third message.
  • the access network device corresponding to the first terminal receives the second information.
  • the second information may be used for the access network device to configure a radio bearer for transmitting the data of the multicast service or for the access network device to release resources for transmitting the data of the multicast service to the first terminal. It may include one or more of a radio bearer for transmitting multicast service data to the first terminal, multicast QoS information corresponding to the multicast service, or unicast QoS information corresponding to the multicast QoS information.
  • the first session management function network element After the first session management function network element receives the third message, if it is determined that the multicast session is activated and/or the PDU session associated with the multicast session of the first terminal is activated, the first session management function network element sends the first
  • the access network device corresponding to the terminal sends the second information
  • the second information may be used by the access network device to configure a radio bearer for transmitting multicast service data, and the radio bearer may be a multicast radio bearer and/or a single broadcast radio bearer or radio bearer.
  • the first session management function network element After the first session management function network element receives the third message, if it is determined that the multicast session is released and/or the PDU session associated with the multicast session of the first terminal is deactivated, the first session management function network element sends a message to The access network device corresponding to the first terminal sends second information, and the second information may be used by the access network device to release resources used to transmit data of the multicast service to the first terminal, and the resources include resources used to transmit multicast service data to the second terminal.
  • the first session management network element receives the third message.
  • the access network device retains the unicast QoS information corresponding to the multicast QoS information corresponding to the multicast session, And when the unicast QoS information does not need to be updated, the first session management functional network element may not send the second information to the access network device corresponding to the first terminal.
  • the unicast QoS information corresponding to the multicast QoS information corresponding to the multicast session is not retained in the access network device, and the first session management function network element may/need to report to the second An access network device corresponding to a terminal sends the second information.
  • the access network device retains the unicast QoS information corresponding to the multicast QoS information corresponding to the multicast session, and when the unicast QoS information needs to be updated, the first The network element with the session management function may/need to send the second information to the access network device corresponding to the first terminal.
  • the first session management functional network element may/need to send the second information to the access network device corresponding to the first terminal.
  • the second information is used for the access network device to configure a radio bearer for transmitting data of the multicast service.
  • the second information includes at least one of the following, the identification information of the multicast session, the multicast quality of service QoS information corresponding to the multicast session, the unicast QoS information corresponding to the multicast QoS information, or the unicast QoS information corresponding to the multicast quality of service flow QoS Flow Broadcast QoS Flow ID.
  • the second information includes at least one of the following: QoS configuration information (QoS profile) corresponding to the multicast session, and the QoS configuration information may include multicast QoS information corresponding to the multicast session (or called multicast QoS configuration information (multicast QoS profile)) and/or the unicast QoS information corresponding to the multicast QoS information corresponding to the multicast session.
  • QoS configuration information QoS profile
  • multicast QoS configuration information multicast QoS profile
  • the second information may be included in N2 SM information (N2 SM Information) or the second information may be N2 SM Information, and the second information is sent to the access network device by the first session management function network element, which is used for the access network device
  • a radio bearer such as a data radio bearer (DRB) or a multicast radio bearer (MRB) for transmitting data of the multicast service is allocated according to the second information.
  • DRB data radio bearer
  • MMB multicast radio bearer
  • the second information is used for the access network device to release resources for transmitting data of the multicast service to the first terminal.
  • the second information may include one or more of the following: the identification information of the multicast session, the unicast QoS Flow ID corresponding to the multicast QoS Flow, the multicast quality of service QoS information corresponding to the multicast session, and the corresponding multicast QoS Flow ID.
  • Unicast QoS information, or a release indication the release indication is used to indicate the release of the multicast QoS information corresponding to the multicast session and/or the unicast QoS information corresponding to the multicast QoS information corresponding to the multicast session.
  • the multicast QoS information (for example, multicast QoS configuration information (QoS Profile)) corresponding to the multicast session may be used to establish or indicate the transmission resource used to transmit the multicast service in the multicast session.
  • the multicast QoS information may be used by the access network device to configure the DRB, MRB or RB corresponding to the multicast session.
  • the multicast QoS information may include one or more of the following: identification information of the multicast QoS flow (such as multicast QFI), QoS parameters corresponding to the multicast QoS flow (for example, QoS profile, including but not limited to 5QI, ARP, session-AMBR, etc.), tunnel information corresponding to the multicast QF.
  • the multicast QoS flow may be the QoS flow used to transmit the data of the multicast service included in the PDU session of the first terminal.
  • the tunnel information corresponding to the multicast QoS flow may be used to identify a tunnel for transmitting data of the multicast service to the first terminal through the multicast transmission mode.
  • the unicast QoS information corresponding to the multicast QoS information can be used to establish or indicate the transmission resource used to transmit the multicast service in the unicast session corresponding to the multicast service (that is, the PDU associated with the multicast session) .
  • the unicast QoS information corresponding to the multicast QoS information can be used to establish a unicast QoS flow (QoS Flow, QF), or to indicate that the established unicast QF can be used to transmit multicast services QF of the data.
  • the unicast session corresponds to the first terminal, and the unicast session may be called a PDU session of the first terminal, and the PDU session of the first terminal is used to transmit data of a multicast service.
  • the unicast QoS information corresponding to the multicast QoS information may include one or more of the following: identification information of unicast QF (such as unicast QFI), QoS parameters corresponding to unicast QF (such as QoS profile, including but not limited to 5QI , ARP, session-AMBR, etc.).
  • the first session management function network element sending the second information to the access network device corresponding to the first terminal according to the third message may include: the first session management function network element carries the information of the first terminal carried in the third message.
  • the identification information finds the context of the PDU session associated with the multicast session of the first terminal, obtains the unicast QoS information corresponding to the multicast QoS information from the context of the PDU session of the first terminal, and/or according to the group information carried in the third message
  • the identification information of the multicast session is used to find the context of the multicast session, and the multicast QoS information corresponding to the multicast session is obtained from the context of the multicast session, and the identification information of the multicast session, the multicast QoS information corresponding to the multicast session, and the multicast
  • One or more types of information such as unicast QoS information corresponding to the QoS information and an indication to release the multicast QoS information corresponding to the multicast session and/or the unicast QoS information
  • the first session management function network element sending the second information to the access network device corresponding to the first terminal according to the third message may include: the first session management function network element carries the second information in the N2 SM message ( N2 SM Information) or the second information can be N2 SM Information, carry the second information in N1N2 message (such as Namf_Communication_N1N2MessageTransfer) or PDU session update session management context response (Nsmf_PDUSession_UpdateSMContext response) and send it to the access and mobility management function network
  • N1N2 message such as Namf_Communication_N1N2MessageTransfer
  • PDU session update session management context response Nsmf_PDUSession_UpdateSMContext response
  • the network element with the access and mobility management function obtains the N2 SM message, carries the N2 SM message in the N2 message and sends it to the access network device, triggering the access network device to configure the wireless bearer or release of the multicast service data A resource used to transmit
  • the N2 SM message may correspond to the first terminal.
  • the N2 SM message may be a PDU session resource establishment request or response corresponding to the PDU session of the first terminal (PDU session resource setup request/ response) or PDU session resource modify request or response (PDU session resource modify request/esponse).
  • the N2 SM message may be a PDU session resource establishment request or response corresponding to the PDU session of the first terminal (PDU session resource setup request/response) or PDU session resource modification request or response (PDU session resource modify request/esponse).
  • the access network device corresponding to the first terminal may configure a wireless bearer for transmitting multicast service data according to the second information, or release resources corresponding to the multicast session, and transfer the second information to A terminal removes from the multicast session, releases unicast QoS information corresponding to the multicast QoS information, and the like.
  • N2 SM Information can be PDU session resource setup request transfer (PDU session resource setup request transfer) or PDU session resource setup reply transmission (PDU session resource setup Response Transfer) or PDU session resource modification request transmission (PDU session resource modify request transfer) or PDU session resource modify response transfer (PDU session resource modify response transfer) or PDU session resource notification transfer (PDU session resource notify transfer) or PDU session resource modification instruction transfer (PDU session resource modify indication transfer) or PDU session resource Modify confirmation transfer (PDU session resource modify confirm transfer) or PDU session resource release command transfer (PDU session resource release command transfer) or PDU session resource notify release transfer (PDU session resource notify released transfer) or PDU session resource release reply transfer (PDU session resource release reply transfer) session resource release response transfer), not limited.
  • the first session management function network element may instruct the access and mobility management function network element to indicate the terminal in CM-CONNECTED to the first session management function network element, triggering the first session management function network element Send related information for configuring the radio bearer corresponding to the multicast session to the access network device corresponding to the first terminal, so that the access network device corresponding to the first terminal configures the radio bearer and/or the multicast session corresponding to the multicast session
  • the radio bearer corresponding to the associated PDU session ensures that the first terminal can normally receive data of the multicast service.
  • FIG. 7 is a communication method provided by the embodiment of the present application. As shown in FIG. 7, it may include:
  • the second session management function network element determines to activate the multicast session or determines to activate the multicast session; or the second session management function network element determines to release the multicast session or determines to release the multicast session.
  • S701 is the same as S501 and will not be described in detail.
  • S702 The second network element with the session management function sends the first message to the first network element with the session management function.
  • the first network element with the session management function receives the first message from the second network element with the session management function.
  • the first session management functional network element sends a second message to the access and mobility management functional network element according to the first message.
  • the access and mobility management functional network element receives the second message from the first session management functional network element.
  • the access and mobility management function network element receives the second message from the first session management function network element, for the terminal in the CM-IDLE state among the terminals joining the multicast session or for the terminal in the CM-IDLE state
  • the terminal executes S704-S706.
  • S707 is directly executed.
  • the access and mobility management function network element may not perceive whether the terminal joins the multicast session, or may sense whether the terminal joins the multicast session. Sensing that a terminal joins a multicast session means that the access and mobility management function network element knows whether the terminal is in the multicast group corresponding to the multicast session. For example, when the access network device stores the context of the multicast session (such as MBS session context ), the access and mobility management function network element can perceive the terminal joining the multicast session.
  • the context of the multicast session such as MBS session context
  • the access and mobility management function network element can perceive the terminal joining the multicast session, and can perceive the CM state; otherwise, when the access and mobility management function network element does not store the context of the multicast session (such as MBS session context), the access and mobility management function network element does not perceive that the terminal joins the multicast session. At this time, The access and mobility management network element does not perceive the terminal joining the multicast session, but can perceive the CM status of the terminal.
  • the access and mobility management function network element does not perceive the terminal joining the multicast session, but can perceive the CM status of the terminal.
  • the access and mobility management function network element as an example that can perceive the terminal joining the multicast session.
  • the network element that has joined the multicast session and is in the CM-IDLE state The terminal may include one terminal or multiple terminals, such as a first terminal, a third terminal, and so on.
  • a terminal that has joined a multicast session and is in the CM-IDLE state can refer to a terminal that has joined a multicast session and has no NAS signaling connection with the network element of the access and mobility management function, and cannot report to the network element of the access and mobility management function.
  • the terminal that sends NAS signaling The terminal can join the multicast session through the PDU session of the terminal.
  • the terminals that have joined the multicast session and are in the CM-CONNECTED state may also include one terminal or multiple terminals, such as a second terminal and a fourth terminal.
  • S704 The access and mobility management functional network element pages the terminal in the CM-IDLE state according to the second message.
  • the terminal in the CM-IDLE state may include one terminal or multiple terminals, such as a first terminal, a second terminal and so on.
  • the first terminal may be any terminal in FIG. 2 .
  • the first terminal can complete the network registration through the access and mobility management function network element, and the access and mobility management function network element provides the NAS signaling service for the first terminal.
  • the first terminal can also send a PDU session establishment request/PDU session to the first session management function network element through the access and mobility management function network element
  • a modification request (PDU session modification request/PDU session establishment request)
  • a PDU session establishment request/PDU session modification request may carry the identification information of the PDU session of the first terminal and the identification information of the multicast session to trigger the first session management function network Adding the first terminal to the multicast session according to the identification information of the multicast session.
  • the PDU session establishment request can be used to request to establish the PDU session of the first terminal
  • the PDU session modification request can be used to request to modify the PDU session of the first terminal, that is, to join the first terminal to the multicast through the PDU session establishment process or the PDU session establishment process session, at this time, the PDU session of the first terminal is associated with the multicast session, and the PDU session of the first terminal can be used for the first terminal to join the multicast session.
  • the access and mobility management function network element may store the context of the first terminal (such as UE context), the context of the first terminal includes the CM state information of the first terminal, the CM The status information may be used to indicate whether the first terminal is in the CM-IDLE state or the CM-CONNECTED state.
  • the network element with the access and mobility management function can know that the first terminal joins the multicast session according to the information sent by the network element with the first session management function.
  • the network element with the performance management function sends the second message carrying the identification information of the multicast session and the UE list, and the network element with the access and mobility management function receives the second message, if it is determined according to the second message that the UE list includes the identification of the first terminal information, it is determined that the first terminal joins the multicast session.
  • the access and mobility management function network element learns that the first terminal has joined the multicast session, it can check the context of the first terminal.
  • the CM status information in the context of the first terminal indicates that the first terminal is in the CM-CONNECTED state
  • the access and mobility management function network element may, according to the second message and the multicast capability information of the access network device in the registration area of the terminal that has joined the multicast session and is in the CM-IDLE state, (immediately ) to page the terminal that has joined the multicast session and is in the CM-IDLE state.
  • the access and mobility management function network element may determine the terminal that has joined the multicast session according to the identification information of the multicast session carried in the second message, or determine the terminal that has joined the multicast session according to the identification information of the multicast session and the identification information of the terminal that joined the multicast session Determine the terminals that have joined the multicast session, or determine the terminals that have joined the multicast session according to the identification information of the terminals that have joined the multicast session, or determine the terminals that have joined the multicast session according to the identification list of terminals that have joined the multicast session. For a terminal that has joined a multicast session, check the CM status of the terminal in the context of the terminal saved by the access and mobility management network element.
  • CM-IDLE If the CM status of the terminal is CM-IDLE, obtain it from the context of the terminal The terminal's registration area information, according to the terminal's registration area information, obtains the access network equipment included in the terminal's registration area, and then determines to send to the access network device according to the multicast capability information of the terminal's registration area.
  • the paging message carrying the identification information of the multicast session is also the paging message carrying the identification information of the terminal.
  • the registration area of the terminal may include one or more access network devices.
  • the access network devices included in the registration area of the terminal there are access network devices that support the multicast function and/or access network devices that do not support the multicast function. equipment.
  • the multicast capability information of the access network device may be used to indicate whether the access network device supports the multicast function or whether the access network device has the multicast capability.
  • An access network device that supports the multicast function can identify the identification information of the multicast session, and an access network device that does not support the multicast function cannot identify the identification information of the multicast session.
  • the ability of an access network device to have multicast means that the access network device has one or more of the following functions: the access network device supports data transmission of multicast services through the 5GC shared MBS traffic delivery method shown in Figure 3c, supports Enhanced signaling plane interaction with core network control plane elements for multicast services, supports receiving multicast service data from core network user plane functional network elements, supports local processing of multicast service data, and supports air interface through point-to-point Multicasting the data of the multicast service and configuring the response terminal to receive the data of the multicast service.
  • the capability information of the access network device may include the specific multicast capability of the access network device or the access network device does not have the multicast capability, and may also include an indication information corresponding to the multicast capability of the access network device, the indication information Indicates the multicast capability of the access network device.
  • the indication information can be binary bit 0 or 1. If the indication information is binary bit 0, it means that the access network device has multicast capability. If the indication information is binary bit 1, it means The access network equipment does not have the multicast capability.
  • the multicast capability information of the access network device can be obtained by the access and mobility management function network element when the access network device and/or access and mobility management function network element is powered on (or the device is deployed on the network and starts to work).
  • the mobility management function network element is obtained from the access network device.
  • the network element with the access and mobility management function and/or the access network device exchange respective configuration information, and the configuration information may include access Multicast capability information of network equipment, capability information of network elements with access and mobility management functions, load information of access network equipment, etc.
  • the multicast capability information of the access network device is as above.
  • the capability information of the access and mobility management function network element can be used to indicate whether the access and mobility management function network element supports providing NAS signaling services for the terminals joining the multicast session, and the load information of the access network equipment can be used It is used to indicate the number of terminals accessing the access network device, etc.
  • the access and mobility management function network element obtains the multicast capability of the access network device through the pre-configuration information sent by the network management (such as operations, administration and maintenance (OAM)) information.
  • the network management can obtain the multicast capability information of the access network device when the access network device is connected to the network, carry the multicast capability information of the access network device in the pre-configuration information and pre-configure it to the network element with the access and mobility management function.
  • OAM operations, administration and maintenance
  • the network element with the access and mobility management function - The multicast capability information of the access network equipment in the registration area of the terminal in the IDLE state, (immediately) paging the terminal that has joined the multicast session and is in the CM-IDLE state may include:
  • the access and mobility management function network element sends a paging message to the first access network device, and the paging message includes the multicast session identification information; and/or, if the second access network device in the registration area of the first terminal does not support the multicast function, the access and mobility management function network element sends a paging message to the second access network device, and the paging
  • the paging message includes the identification information of the first terminal, that is, UE granular paging is performed.
  • the registration area of the second terminal also includes the first access network device, and the first terminal is different from the second terminal, a paging message message including the identification information of the multicast session is sent to the first access network device once That is, there is no need to send paging messages to the first access network device multiple times, so as to reduce signaling overhead.
  • a paging message carrying identification information of a multicast session is sent to the access network device, so that the access network device identifies the identification information of the multicast session included in the paging message, Initiate group paging for multiple terminals that have joined the multicast session and are in the CM-IDLE state (such as RRC_inactive state or RRC_IDLE state) according to the identification information of the multicast session, saving signaling overhead.
  • CM-IDLE state such as RRC_inactive state or RRC_IDLE state
  • UE1 and UE2 in the CM-IDLE state are pre-allocated registration areas, and the registration area of UE1 includes the number 1 Base station, base station No. 2, and base station No. 3.
  • the registration area of UE2 includes base station No. 2, base station No. 3, and base station No. 4. If base station No. 2 and base station No. 3 support the multicast function, and base station No. 1 and base station No. 4 do not support the multicast function, the AMF sends a paging message carrying identification information of the multicast session to base station No. 2 and base station No. 3 message, so that base station No. 2 and base station No.
  • the AMF sends a paging message carrying identification information of UE1 to base station No. 1, and sends a paging message carrying identification information of UE2 to base station No. 4.
  • paging the terminal that has joined the multicast session and is in the CM-IDLE state according to the second message by the access and mobility management function network element may include: the access and mobility management function network element according to the second message , sending a fourth message to the access network device in the registration area of the terminal that has joined the multicast session and is in the CM-IDLE state; the fourth message includes the identification information and group information of the terminal that has joined the multicast session and is in the CM-IDLE state The identification information of the broadcast session. For example, assuming that the terminals that have joined the multicast session and are in the CM-IDLE state include the first terminal, the fourth message may include identification information of the first terminal and identification information of the multicast session.
  • the fourth message may be used by the access network device to page the terminal that has joined the multicast session and is in the CM-IDLE state and the terminal that the access network device provides the network service for, such as triggering the access network device to According to the fourth message and the multicast capability information of the access network device, among the terminals that have joined the multicast session and are in the CM-IDLE state, the terminal that is provided with the network service by the access network device is paged.
  • the access network device paging the terminals that have joined the multicast session and are in the CM-IDLE state to provide network services by the access network device according to the fourth message and the multicast capability information of the access network device
  • the terminal may include: if the access network device supports the multicast function, the access network device recognizes the identification information of the multicast session in the fourth message, and the access network device only sends a The paging message is enough to reduce the signaling overhead of paging.
  • the access network device does not support the multicast function, the access network device cannot identify the identification information of the multicast session included in the fourth message, and the access network device includes the identification information of the terminal carried in the fourth message in its
  • the coverage area sends one or more paging messages for per UE, and the paging messages may include terminal identification information.
  • terminals in the CM-IDLE state that join the multicast session and are in the inactive state include UE1-UE4, UE1 and UE2 are under the No. 1 base station, UE3 and UE4 are under the Under No. 2 base station, No. 1 base station supports the multicast function, and No. 2 base station does not support the multicast function.
  • No. 1 base station and No. 2 base station receive the fourth message, No. 1 base station sends a search request carrying the identification information of the multicast session.
  • the paging message implements group paging for UE1 and UE2, and base station No. 2 sends a paging message carrying identification information of UE3 and a paging message carrying identification information of UE4 after receiving the fourth message.
  • the terminal (such as the first terminal) that has joined the multicast session receives the paging message
  • the terminal finds that the PDU session associated with the multicast session is deactivated or the terminal determines that it has a group broadcast service requirements or paging response according to the existing technology
  • the terminal initiates/sends a service request (service request) to the access and mobility management function network element through the access network device corresponding to the terminal .
  • the method may further include:
  • the first terminal finds that the PDU session associated with the multicast session is in a deactivated state or the first terminal determines that it has a multicast service requirement or needs to perform a paging response according to the prior art, then the first terminal Initiate/send a service request (service request) to the access and mobility management function network element through the access network device corresponding to the first terminal.
  • the access and mobility management functional network element receives the service request.
  • the service request may be used to establish a NAS signaling connection between the first terminal and the access and mobility management functional network element, and the service request may include identification information of the first terminal.
  • the access and mobility management functional network element establishes a NAS signaling connection between the first terminal and the access and mobility management functional network element according to the service request, and changes the first terminal from the CM-IDLE state to (switch to ) CM-CONNECTED state, sending a third message to the first session management function network element.
  • the first session management function network element receives the third message from the access and mobility management function network element.
  • S707 According to the second message, if there is a first terminal in the CM-CONNECTED state (or it is described that the first terminal is in the CM-CONNECTED state) according to the second message, the network element with the access and mobility management function directly reports to the first session management function network element Send the third message. Correspondingly, the first session management function network element receives the third message from the access and mobility management function network element.
  • the first session management function network element sends the second information to the access network device corresponding to the first terminal according to the third message.
  • the access network device corresponding to the first terminal receives the second information.
  • the access and mobility management function network element corresponding to the second terminal receives After receiving the second message, it is found that the second terminal is also in the CM-IDLE state, and the access and mobility management function network element corresponding to the second terminal can also refer to the above S704-S706 to page the second terminal first, and wait until the second terminal is in the CM-IDLE state.
  • the fifth message may include the identification information of the second terminal and/or the identification information of the multicast session, so as to trigger the first session management network element to instruct the second terminal
  • the corresponding access network device configures a radio bearer for transmitting the data of the multicast service to the second terminal or releases resources for transmitting the data of the multicast service to the second terminal.
  • the access and mobility management function network element corresponding to the second terminal finds that the second terminal is in the CM-CONNECTED state, then the access and mobility management function network element corresponding to the second terminal also Referring to the above S707, the second terminal in the CM-CONNECTED state can be directly indicated/notified to the first session management network element, and the first session management network element is triggered to instruct the access network device corresponding to the second terminal to be configured to communicate with the second terminal.
  • the terminal transmits the radio bearer of the data of the multicast service or releases the resources used for transmitting the data of the multicast service to the second terminal, and the like.
  • the access and mobility management function network element determines that the terminal joining the multicast session is in the CM-CONNECTED state
  • the access and mobility management function network element triggers the first session management function network element to
  • the relevant information for configuring the radio bearer corresponding to the multicast session is sent to the access network device corresponding to the first terminal, so that the access network device corresponding to the first terminal configures the radio bearer corresponding to the multicast session and/or the multicast session association
  • the radio bearer corresponding to the PDU session ensures that the first terminal can normally receive the data of the multicast service.
  • the access and mobility management function network element when the access and mobility management function network element determines that the terminal joining the multicast session is in the CM-CONNECTED state, the access and mobility management function network element will instruct the first session management function network to element, triggering the first session management function network element to instruct the access network device to release the resource used to transmit the data of the multicast service to the first terminal, and the resource includes the resource used to transmit the data of the multicast service to the first terminal.
  • the core network device when the multicast session is activated, notifies the access network device to configure the radio bearer. At this time, if there are multiple terminals, the access network device needs to be notified multiple times to configure the radio bearer, increasing the Signaling overhead.
  • Fig. 8 is a communication method provided by the embodiment of the present application. As shown in Fig. 8, it may include:
  • the access network device determines that a multicast session corresponding to the multicast service is activated.
  • the access network device may be the access network device supporting the multicast function in the system shown in FIG. 2 .
  • the access network device determines the activation of the multicast session according to method 1 or method 2:
  • Mode 1 When the access network device receives the data of the multicast service from the MB-UPF, the access network device determines to activate the multicast session corresponding to the multicast service.
  • the access network device when the multicast session is deactivated, the N3mb tunnel between the MB-UPF corresponding to the multicast session and the access network device is not released.
  • the access network device receives data from the N3mb tunnel, the access network device can determine that the data received from the N3mb tunnel is a multicast session according to the correspondence between the tunnel information of the N3mb tunnel and the identification information of the multicast session corresponding multicast service data, and then determine to activate the multicast session.
  • Method 2 The access network device receives an eighth message from an access and mobility management function network element; wherein, the eighth message may be used to indicate activation of the multicast session, and the eighth message may include identification information of the multicast session; then The network access device may determine that the multicast session corresponding to the multicast service needs to be activated according to the eighth message.
  • the eighth message may be an N2 message, and the N2 message is a message at the granularity of a node (such as an access network device), that is, the N2 message is a per node message.
  • the network element with the second session management function receives the notification of multicast session activation (MBS session activation) from AF/AS or MBSF or NEF, or MB-UPF detects the arrival of multicast service data, and notifies the second session management
  • the second session management functional network element can determine the identification information of the access and mobility management functional network element, and send the access and mobility
  • the network element with the management function sends a notification of activation of the multicast session.
  • the notification may be an N11mb message, and the N11mb message may include identification information of the multicast session.
  • the N11mb message may also include an indication/notification of preparing/configuring a multicast radio bearer for the multicast session.
  • the access and mobility management function network element sends the eighth message to the access network device.
  • the access and mobility management functional network element may be an AMF that provides NAS signaling services for terminals joining the multicast session, or may be an AMF that serves the multicast session.
  • the second session management function network element obtains the identification information of the access and mobility management function network element from the first network element, for example, the second session management function network element can send a multicast session to the first network element
  • the first network element receives the identification information of the multicast session, searches for the access and mobility management function network element that can serve the multicast session, and sends the identification information of the access and mobility management function network element to the second session management function network element.
  • the second session management function network element stores the identification information of the access and mobility management function network element.
  • the first network element may be NRF, UDM, UDR, or PCF, and may also be other network elements storing identification information of network elements with access and mobility management functions, without limitation.
  • the first network element stores the corresponding relationship between the identification information of the access and mobility management function network element and the identification information of the multicast session.
  • the access network device may activate the multicast session corresponding to the multicast session, for example, the access network device configures the multicast QoS information corresponding to the multicast session
  • the multicast radio bearer can be used to transmit the data of the multicast service.
  • the relevant description of the multicast QoS information corresponding to the multicast session is as described in the embodiment corresponding to FIG. 7 , and will not be repeated here.
  • the multicast QoS information corresponding to the multicast session is not released by the access network device when the multicast session is deactivated, and the multicast QoS information corresponding to the multicast session is retained in the access network device, for example, the group in the context of a broadcast session.
  • the access network device sends a message to the access and mobility management function network element corresponding to the terminal joining the multicast session, and the message can be used to indicate the activation of the multicast session, so that the access and mobility management function network element
  • the first session management function network element is notified of the activation of the multicast session, and the first session management function network element is triggered to set the state of the multicast session as an active state.
  • the terminal joining the multicast session in S802 may refer to a terminal joining the multicast session for which the access network device provides network services.
  • the terminals that join the multicast session and are provided with network services by the access network device may include one or more terminals, and the access network device may send a corresponding
  • the access and mobility management functional network element sends a message indicating the activation of the multicast session.
  • the terminals joining the multicast session include the first terminal, and the access network device may send the sixth message to the network element with the access and mobility management function corresponding to the first terminal.
  • the access and mobility network element corresponding to the first terminal The sex management function network element receives the sixth message.
  • the sixth message may be used to indicate that the multicast session is activated, and the sixth message may include identification information of the multicast session.
  • the sixth message may be an N2 message corresponding to the first terminal.
  • the terminals joining the multicast session also include the second terminal
  • the access network device may send the seventh message to the access and mobility management function network element corresponding to the second terminal, and correspondingly, the access network element corresponding to the second terminal Receive the seventh message with the mobility management function network element.
  • the seventh message may be used to indicate that the multicast session is activated, and the seventh message may include identification information of the multicast session.
  • the seventh message may be an N2 message corresponding to the second terminal.
  • the access network device may use the identification information of the multicast session as an index to find the context of the multicast session, and determine the terminal identified by the terminal identification information included in the context of the multicast session as joining the multicast session and A terminal for which network services are provided by the access network equipment.
  • the access and mobility management functional network element sends a tenth message to the first session management functional network element.
  • the first session management functional network element receives the tenth message from the access and mobility management functional network element.
  • the access and mobility management function network element in S803 may be the access and mobility management function network element corresponding to the first terminal
  • the first session management function network element may be the session management function network element corresponding to the first terminal
  • the first session management function network element can be used to manage the PDU session associated with the multicast session of the first terminal.
  • the first session management function network element stores the context of the multicast session, the context of the PDU session associated with the multicast session, and the like.
  • the tenth message may be used to indicate that the multicast session is activated or to activate the multicast session, and the tenth message may include identification information of the multicast session.
  • the tenth message may be an N11 message, and the N11 message may be a PDU session context update request/reply (Nsmf_PDUSession_UpdateSMContext Request/Response).
  • the tenth message may also include a notification of activation of the multicast session.
  • the network element with the access and mobility management function can know the corresponding relationship between the sixth message and the first terminal.
  • the sixth message is a message of the first terminal.
  • the identification information of the first terminal the PDU session of the first terminal and the PDU session associated with the multicast session are determined, and the access and mobility management function network element communicates with the first session management
  • the control plane signaling message corresponding to the PDU session between functional network elements sends a tenth message.
  • the first session management functional network element sets the state of the multicast session to an active state according to the tenth message.
  • the first session management function network element can find the context of the multicast session saved by the first session management function network element according to the identification information of the multicast session carried in the tenth message, and multicast the multicast session in the context of the multicast session The state of the session changes from deactivated to active.
  • the method shown in FIG. 8 may further include: if there is a PDU session associated with the multicast, and the state of the PDU session is deactivated, the first session management functional network element activates the PDU session. If there is a multicast-associated PDU session, and the status of the PDU session is deactivated, since the first session management function network element has received the notification of multicast session activation, the first session management function network element does not deactivate the associated PDU session .
  • activating the PDU session by the first session management function network element may include: the first session management function network element sends an N1N2 message transfer (Namf_Communication_N1N2Message Transfer) to the access and mobility management function network element.
  • the N1N2 message transmission includes N2 SM Information (N2 SM Information), and the N2 SM message includes the identification information of the multicast session.
  • the N2 SM message can be a PDU session resource setup request transfer (PDU session resource setup request transfer) or a PDU session resource modification Request transfer (PDU session resource modify request transfer).
  • the access and mobility management function network element receives the N1N2 message transmission, and sends the N2 message to the access network device, including the N2 SM Information.
  • the N2 message may be a PDU session resource setup request (PDU session resource setup request) or a PDU session resource modification request (PDU session resource modify request).
  • the access network device After receiving the N2 message, the access network device prepares/configures a radio bearer (such as DRB) for the PDU session.
  • the access network device replies an N2 message to the access and mobility management function network element.
  • the N2 message can be a PDU session resource setup response (PDU session resource setup response) or a PDU session resource modify response (PDU session resource modify response).
  • the N2 message Contains the reply of the N2 SM message to the first session management function network element, that is, the PDU session resource setup response transfer (PDU session resource setup response transfer) or the PDU session resource modification request transfer (PDU session resource modify response transfer), N2 SM
  • the information carries the tunnel information allocated by the access network device (such as the access network tunnel information (AN tunnel Info) of the access network device, which can be used for the first session management function network element to notify the anchor point of the PDU session ( PDU session anchor, PSA), in order to establish a downlink tunnel between the PSA and the access network device. So far, the PDU session associated with the multicast session is activated.
  • the access network device after the access network device activates the multicast session, the access network device notifies the first session management function network element to also activate the multicast session through the access and mobility management function network element, so as to ensure The state of the multicast session maintained between network elements is unified. At the same time, there is no need for the network element of the core network to notify the access network device corresponding to the terminal to join the multicast session with the terminal as the granularity, reducing signaling overhead.
  • the PDU session associated with the multicast session is in the deactivated state, after the access network device activates the multicast session, it can also link with the multicast session according to the context of the PDU session
  • the unicast QoS information corresponding to the corresponding multicast QoS information configures a unicast radio bearer for the terminal corresponding to the PDU session; wherein the unicast radio bearer can be used to transmit multicast service data to the terminal through the PDU session.
  • the unicast QoS information corresponding to the multicast QoS information corresponding to the multicast session in the context of the PDU session is not released/not sent from the access network
  • the device is deleted and remains on the access network device, so that when the multicast session is activated, the access network device can correspond to the multicast QoS information corresponding to the multicast session in the context of the PDU session associated with the multicast session
  • the unicast QoS information of the terminal establishes a unicast radio bearer for the terminal, and activates the PDU session associated with the multicast session. Specifically, referring to the method shown in FIG. 9 below, when the PDU session associated with the multicast session is deactivated, the unicast QoS information
  • Fig. 9 is a communication method provided by an embodiment of the present application. As shown in Fig. 9, the method may include:
  • the first session management function network element determines to deactivate the PDU session.
  • the first session management functional network element may be an SMF that manages PDU sessions.
  • the PSA corresponding to the PDU session may send a notification that data transmission has not been detected to the first session management function network element, and the first session management function network element After receiving the notification of the PSA, it is determined to deactivate the PDU session according to the notification of the PSA.
  • the first session management function network element sends a ninth message to the access network device.
  • the access network device receives the ninth message from the first session management function network element.
  • the ninth message may include identification information of the PDU session.
  • the ninth message may be used to indicate to deactivate the PDU session, and may also be used for the access network device to reserve the unicast QoS information corresponding to the multicast QoS information corresponding to the multicast session of the PDU session.
  • the ninth message may also include identification information of the multicast session and/or fourth indication information, and the fourth indication information may indicate that the multicast session corresponding to the multicast session is reserved.
  • the association between the PDU session and the multicast session may include one or more of the following: the identification information of the multicast session is stored in the context of the PDU session (such as in the session management context (session management context, SM context) of the PDU session, Or, the identification information of the PDU session (such as the SM context ID of the PDU session, etc.) or the identification information of the terminal corresponding to the PDU session is stored in the context of the multicast session (such as MBS session context).
  • the identification information of the multicast session is stored in the context of the PDU session (such as in the session management context (session management context, SM context) of the PDU session, Or, the identification information of the PDU session (such as the SM context ID of the PDU session, etc.) or the identification information of the terminal corresponding to the PDU session is stored in the context of the multicast session (such as MBS session context).
  • the first session management function network element sending the ninth message to the access network device may include: the first session management function network element carries the ninth message in the N1N2 message transmission (Namf_Communication_N1N2Message Transfer) corresponding to the PDU session Send it to the access and mobility management function network element, the access and mobility management function network element receives the N1N2 message transmission, obtains the ninth message from it, carries the ninth message in the N2 message and sends it to the interface corresponding to the PDU session
  • the N2 message may be a PDU session resource release command/request transfer (PDU session resource release command/request transfer).
  • the access network device reserves the unicast QoS information corresponding to the multicast QoS information corresponding to the multicast session in the context of the PDU session according to the ninth message.
  • the ninth message includes identification information of the PDU session, identification information of the multicast session and/or fourth indication information
  • the access network device may determine to deactivate the PDU session according to the identification information of the PDU session carried in the ninth message. Reserving/not releasing the unicast QoS information corresponding to the multicast QoS information corresponding to the multicast session according to the identification information of the multicast session carried in the ninth message and/or the fourth indication information.
  • the access network device may also retain/not release the identification information of the PDU session (for example, the ID of the PDU session).
  • the ninth message includes identification information of the PDU session, and the access network device may determine to deactivate the PDU session according to the identification information of the PDU session carried in the ninth message. At this time, the access network device determines whether the PDU session It is associated with a multicast session. If the PDU session is associated with a multicast session, the access network device retains/does not release the unicast QoS information corresponding to the multicast QoS information corresponding to the multicast session. Optionally, the access network device may also retain/not release the identification information of the PDU session (for example, the ID of the PDU session).
  • the access network device for the access network device supporting the multicast function, stores the context of the multicast session (such as MBS session context).
  • the access network device also stores the context of the terminal joining the multicast session (such as NGAP UE context) (Note: NGAP UE context is different from the UE context in the access and mobility management function network element).
  • NGAP UE Context of the access network device there are contexts of all PDU sessions of the terminal, wherein for a PDU session used to join a multicast session, the context of the PDU session stores the identification information of the multicast session.
  • the access network device can determine whether the PDU session is associated with the multicast session by checking whether the context of the PDU session includes the identifier of the multicast session.
  • the unicast QoS information corresponding to the multicast QoS information on the access network device is not released, so that when the multicast session is activated, the access network
  • the device can establish a unicast radio bearer according to the unicast QoS information corresponding to the PDU session associated with the multicast session, activate the PDU session associated with the multicast session, and ensure the normal transmission of multicast service data.
  • each node such as an access and mobility management function network element, a first session management function network element, etc.
  • each node such as an access and mobility management function network element, a first session management function network element, etc.
  • each node includes a corresponding hardware structure and/or software module for performing each function in order to realize the above functions.
  • the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed by hardware or computer software drives hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present application.
  • the embodiment of the present application can divide the functional modules of the access and mobility management functional network element, the first session management functional network element, etc. according to the above method example, for example, each functional module can be divided corresponding to each function, or the two Or more than two functions are integrated in one processing module.
  • the above-mentioned integrated modules can be implemented in the form of hardware or in the form of software function modules. It should be noted that the division of modules in the embodiment of the present application is schematic, and is only a logical function division, and there may be other division methods in actual implementation.
  • FIG. 10 shows a structural diagram of a communication device 100.
  • the communication device 100 may be a network element with a first session management function, a chip in a network element with a first session management function, a system on a chip, or other devices capable of implementing the first A device for the function of the session management function network element, etc.
  • the communications device 100 may be configured to execute the function of the first session management function network element involved in the foregoing method embodiments.
  • the communication device 100 shown in FIG. 10 includes: a receiving unit 1002 and a sending unit 1003 . Further, a processing unit 1001 may also be included.
  • the receiving unit 1002 is configured to receive a first message from a second session management function network element, the second session management function network element corresponds to the multicast session, and the first message is used to notify the activation of the multicast session Or it is used to notify the release of the multicast session.
  • the receiving unit 1002 may support the communication device 100 to execute S502.
  • the sending unit 1003 is configured to send first information to the access and mobility management function network element according to the first message, the first information includes identification information and/or indication information of the multicast session, and the indication information is used to indicate group paging .
  • the sending unit 1003 is configured to support the communication device 100 to execute S504.
  • the sending unit 1003 is configured to send a second message to the access and mobility management function network element; wherein, the second message is used for the access and mobility management function network element to be in CM-CONNECTED Indicate the terminal in the state to the first session management function network element.
  • the sending unit 1003 may support the communication device 100 to execute S601 and S703.
  • the receiving unit 1002 is configured to receive a third message from an access and mobility management function network element; wherein, the third message includes the identification information of the first terminal and/or the identification information of the multicast session; the first session management function network
  • the element is used to manage the PDU session associated with the multicast session in the protocol data unit PDU session of the first terminal, and the terminals in the CM-CONNECTED state include the first terminal.
  • the receiving unit 1002 may support the communication device 100 to execute S602 and S706.
  • the receiving unit 1002 is configured to receive a tenth message from an access and mobility management functional network element; the tenth message is used to indicate that the multicast session is activated, and the tenth message includes an identifier of the multicast session information.
  • the receiving unit 1002 is configured to support the communication device 100 to execute S803.
  • the processing unit 1001 is configured to set the state of the multicast session to an active state according to the tenth message.
  • the processing unit 1001 is configured to support the communication device 100 to execute S804.
  • the communication device 100 is used to execute the function of the first session management function network element in the communication methods shown in the methods shown in FIG. 5 to FIG. 9 , so the same effect as the above communication method can be achieved.
  • the communication device 100 shown in FIG. 10 includes: a processing module and a communication module.
  • the processing module is used to control and manage the actions of the communication device 100.
  • the processing module may integrate functions of the processing unit 1001 to execute S804 and other control functions.
  • the communication module can integrate the functions of the sending unit 1003 and the receiving unit 1002, perform S502, S504, S803, S804 and communicate with other network entities, for example, with the functional modules or network entities shown in FIG. 2 or FIG. 3a or FIG. 3b Communication.
  • the communication device 100 may also include a storage module for storing instructions and/or data. When the instruction is executed by the processing module, the processing module implements the above-mentioned method at the side of the network element with the first session management function.
  • the processing module may be a processor, a controller, a module or a circuit. It can realize or execute various exemplary logic blocks described in conjunction with the disclosure content of the embodiments of the present application.
  • the communication module may be a transceiver circuit, a pin, an interface circuit, a bus interface, or a communication interface.
  • 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 device 100 involved in this embodiment of the present application may be the communication device 400 shown in FIG. 4 .
  • FIG. 11 shows a structural diagram of a communication device 110.
  • the communication device 110 may be an access and mobility management function network element, a chip in an access and mobility management function network element, a system on a chip, or other devices capable of implementing the above-mentioned In the method, a device for accessing functions of a network element with a mobility management function and the like.
  • the communication device 110 may be used to execute the function of the access and mobility management functional network element involved in the above method embodiments.
  • the communication device 110 shown in FIG. 11 includes: a processing unit 1101 , a receiving unit 1102 , and a sending unit 1103 .
  • the receiving unit 1102 is configured to receive first information from a network element with a first session management function, where the first information includes identification information and/or indication information of a multicast session, and the indication information is used to indicate that the group seek call.
  • the receiving unit 1102 is configured to support the communication device 110 to execute S504.
  • the processing unit 1101 is configured to set paging according to the first information group.
  • the processing unit 1101 is configured to support the communication device 110 to execute S505.
  • the receiving unit 1102 is configured to receive a second message from the first session management function network element; wherein, the second message is used for the access and mobility management function network element to be in the CM-CONNECTED state The terminal indicated to the first session management function network element.
  • the receiving unit 1102 may support the communication device 110 to execute S601 and S703.
  • the sending unit 1103 is configured to send a third message to the first session management function network element according to the second message; wherein, the third message includes the identification information of the first terminal and/or the identification information of the multicast session; the first session management The functional network element is used to manage the PDU session associated with the multicast session among the protocol data unit PDU sessions of the first terminal, and the terminals in the CM-CONNECTED state include the first terminal.
  • the sending unit 1103 may support the communication device 110 to execute S602, S706 and S707.
  • the receiving unit 1102 is configured to receive a sixth message from the access network device; where the sixth message is used to indicate that the multicast session is activated, and the sixth message includes identification information of the multicast session.
  • the receiving unit 1102 is configured to support the communication device 110 to execute S802.
  • the sending unit 1103 is configured to send a tenth message to the first session management function network element according to the sixth message; wherein, the tenth message is used to indicate activation of the multicast session, and the tenth message includes identification information of the multicast session.
  • the sending unit 1103 is configured to support the communication device 110 to execute S803.
  • the communication device 110 is used to perform the functions of the access and mobility management function network element in the communication methods shown in the methods shown in FIGS. 5 to 9 , so the same effect as the above communication method can be achieved.
  • the communication device 110 shown in FIG. 11 includes: a processing module and a communication module.
  • the processing module is used to control and manage the actions of the communication device 110, for example, the processing module may integrate the functions of the processing unit 1101, and may be used to support the communication device 110 to execute S505 and other steps.
  • the communication module can integrate the functions of the sending unit 1103 and the receiving unit 1102, such as performing S504, S601, S703, S602, S706, S707, S802, S803, etc. Communication between functional modules or network entities is shown.
  • the communication device 110 may also include a storage module for storing instructions and/or data. When the instruction is executed by the processing module, the processing module realizes the above-mentioned method at the network element side of the access and mobility management function.
  • the processing module may be a processor, a controller, a module or a circuit. It can realize or execute various exemplary logic blocks described in conjunction with the disclosed content of the embodiments of the present application.
  • the communication module may be a transceiver circuit, a pin, an interface circuit, a bus interface, or a communication interface.
  • 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 device 110 involved in this embodiment of the present application may be the communication device 400 shown in FIG. 4 .
  • Fig. 12 shows a structural diagram of a communication device 120
  • the communication device 120 may be an access network device, a chip in the access network device, a system on a chip or other devices capable of realizing the functions of the access network device in the above method Wait.
  • the communication device 120 may be configured to execute the functions of the access network device involved in the foregoing method embodiments.
  • the communication device 120 shown in FIG. 12 includes: a processing unit 1201 and a sending unit 1202 .
  • the processing unit 1201 is configured to determine the activation of the multicast session corresponding to the multicast service. For example, the processing unit 1201 may support the communication device 120 to execute S801.
  • a sending unit 1202 configured to send a sixth message to the access network device corresponding to the first terminal; wherein the sixth message is used to indicate that the multicast session is activated, and the sixth message includes the information of the multicast session Identification information, the first terminal is a terminal joining the multicast session.
  • the sending unit 1202 may support the communication device 120 to execute S802.
  • the communication device 120 is used to execute the functions of the access network equipment in the communication methods shown in the methods shown in FIG. 5 to FIG. 9 , so the same effect as the above communication method can be achieved.
  • the communication device 120 shown in FIG. 12 includes: a processing module and a communication module.
  • the processing module is used to control and manage the actions of the communication device 120.
  • the processing module may integrate the functions of the processing unit 1201, and may be used to support the communication device 120 to execute steps such as S801.
  • the communication module may integrate the functions of the sending unit 1202, such as executing S802 and communicating with other network entities, for example, communicating with the functional modules or network entities shown in FIG. 2 or FIG. 3a or FIG. 3b.
  • the communication device 120 may also include a storage module for storing instructions and/or data. When the instruction is executed by the processing module, the processing module is made to implement the above method on the access network device side.
  • the processing module may be a processor, a controller, a module or a circuit. It can realize or execute various exemplary logic blocks described in conjunction with the disclosed content of the embodiments of the present application.
  • the communication module may be a transceiver circuit, a pin, an interface circuit, a bus interface, or a communication interface.
  • 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 device 120 involved in this embodiment of the present application may be the communication device 400 shown in FIG. 4 .
  • the processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and may implement or Execute the methods, steps and logic block diagrams disclosed in the embodiments of the present application.
  • a general purpose processor may be a microprocessor or any conventional processor or the like. The steps of the methods disclosed in connection with the embodiments of the present application may be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules in the processor.
  • the memory may be a non-volatile memory, such as a hard disk (hard disk drive, HDD) or a solid-state drive (solid-state drive, SSD), etc., and may also be a volatile memory (volatile memory), such as Random-access memory (RAM).
  • a memory is, but is not limited to, any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer.
  • the memory in the embodiment of the present application may also be a circuit or any other device capable of implementing a storage function, and is used for storing instructions and/or data.
  • FIG. 13 is a structural diagram of a communication system provided by an embodiment of the present application.
  • the communication system may include: an access and mobility management functional network element 130 and a first session management functional network element 131 .
  • FIG. 13 is only an exemplary drawing, and the embodiment of the present application does not limit the network elements and the number of network elements included in the communication system shown in FIG. 13.
  • FIG. 13 may also include access network equipment, terminal , a second session management function network element, a UPF, an MB-UPF, and the like.
  • the access and mobility management function network element 130 has the functions of the access and mobility management function network element in one or more methods shown in FIG. 5 to FIG. 9 above.
  • the first session management function network element 131 has the function of the first session management function network element in one or more methods shown in FIGS. 5 to 9 above.
  • words such as “exemplary” or “for example” are used to represent examples, illustrations or illustrations, and any embodiment or design described as “exemplary” or “for example” should not be interpreted It is more preferred or more advantageous than other embodiments or design solutions.
  • the use of words such as “exemplary” or “for example” is intended to present related concepts in a specific manner for easy understanding.
  • the technical feature is distinguished by “first”, “second”, “third”, “A”, “B”, “C” and “D”, etc.
  • the technical features described in the “first”, “second”, “third”, “A”, “B”, “C” and “D” have no sequence or order of magnitude among the technical features described.
  • B corresponding to A means that B is associated with A.
  • B can be determined from A.
  • determining B according to A does not mean determining B only according to A, and B may also be determined according to A and/or other information.
  • connection in the embodiment of the present application refers to various connection methods such as direct connection or indirect connection to realize communication between devices, which is not limited in the embodiment of the present application.
  • Transmit in the embodiments of the present application refers to two-way transmission, including actions of sending and/or receiving, unless otherwise specified.
  • transmission in the embodiments of the present application includes sending data, receiving data, or sending data and receiving data.
  • the data transmission here includes uplink and/or downlink data transmission.
  • Data may include channels and/or signals, uplink data transmission means uplink channel and/or uplink signal transmission, and downlink data transmission means downlink channel and/or downlink signal transmission.
  • Network and “system” in the embodiments of the present application express the same concept, and the communication system is the communication network.
  • each functional module in each embodiment of the present application can be integrated into a processing In the controller, it can also be physically present separately, or two or more modules can be integrated into one module.
  • the above-mentioned integrated modules can be implemented in the form of hardware or in the form of software function modules.
  • the technical solutions provided by the embodiments of the present application may be fully or partially implemented by software, hardware, firmware or any combination thereof.
  • software When implemented using software, it may be implemented in whole or in part in the form of a computer program product.
  • the computer program product includes one or more computer instructions.
  • the computer program instructions When the computer program instructions are loaded and executed on the computer, the processes or functions according to the embodiments of the present application will be generated in whole or in part.
  • the computer may be a general computer, a dedicated computer, a computer network, a wireless control device, an access network device, a terminal or other programmable devices.
  • the computer instructions may be stored in or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website, computer, server or data center Transmission to another website site, computer, server or data center by wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.).
  • the computer-readable storage medium may be any available medium that can be accessed by a computer, or a data storage device such as a server or a data center integrated with one or more available media.
  • the available medium may be a magnetic medium (for example, a floppy disk, a hard disk, or a magnetic tape), an optical medium (for example, a digital video disc (digital video disc, DVD)), or a semiconductor medium.
  • the various embodiments may refer to each other, for example, the methods and/or terms between the method embodiments may refer to each other, such as the functions and/or terms between the device embodiments Or terms may refer to each other, for example, functions and/or terms between the apparatus embodiment and the method embodiment may refer to each other.

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Abstract

本申请实施例公开了一种通信方法及装置，涉及通信技术领域，以优化组播业务的处理流程。该方法可以包括：第一会话管理功能网元接收来自第二会话管理功能网元的第一消息，第二会话管理功能网元对应于组播会话，第一消息用于通知组播会话激活或者用于通知组播会话释放；第一会话管理功能网元根据第一消息，向接入与移动性管理功能网元发送第一信息，第一信息包括组播会话的标识信息和用于指示组寻呼的指示信息。

Description

一种通信方法及装置
本申请要求于2021年05月10日提交国家知识产权局、申请号为202110508644.1、申请名称为“一种通信方法及装置”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请实施例涉及通信技术领域，尤其涉及一种通信方法及装置。
背景技术
随着移动互联网的发展，移动高清视频业务呈现井喷态势。用户逐渐从传统的通过固定电视收看热点节目的方式转变为通过手机终端与移动互联网收看热点节目，视频业务对移动网络的冲击愈发强烈。目前，可以通过组播/广播(multicast/broadcast)的方式优化视频业务的传输来大幅减少视频流量对移动网络的冲击，如将视频业务的数据通过组播/广播方式发送给大量用户。
众多移动通信网络架构中，第5代(the 5th generation，5G)移动通信网络架构可以支持组播/广播功能，通过组播/广播方式将组播/广播业务的数据发送给大量用户。针对5G的组播/广播功能的研究中，如何优化组播/广播业务的管理流程，是一个亟待解决的问题。
发明内容
本申请实施例提供一种通信方法及装置，以优化组播业务的处理流程。
为达到上文目的，本申请实施例采用如下技术方案。
第一方面，本申请实施例提供一种通信方法，所述方法包括：第一会话管理功能网元接收来自第二会话管理功能网元的用于通知组播会话激活或者用于通知组播会话释放的第一消息，根据第一消息，向接入与移动性管理功能网元发送第一信息，第一信息包括组播会话的标识信息和/或指示信息，指示信息用于指示组寻呼。第二会话管理功能网元对应于组播会话。
基于第一方面所述的方法，在组播会话激活或者去激活时，第一会话管理功能网元可以向接入与移动性管理功能网元发送指示信息，指示接入与移动性管理功能网元对组播会话对应的终端组寻呼，以优化组播会话对应的终端的寻呼区域，不再重叠区域重复发送寻呼消息，优化寻呼流程，降低寻呼组播群组中的终端带来的信令开销。
一种可能的设计中，所述方法还包括：第一会话管理功能网元根据第一消息，确定在组播会话关联的PDU会话中处于去激活状态的PDU会话的数量满足预设条件。基于该可能的设计，可以在组播会话关联的PDU会话中处于去激活状态的PDU会话达到预设条件再发送组寻呼的指示，降低去激活状态的PDU会话较多时的寻呼信令流程。
一种可能的设计中，指示信息包括第一指示信息或第二指示信息；其中，第一指示信息用于指示采用组寻呼方式寻呼组播会话对应的终端，或第二指示信息用于指示采用组寻呼方式寻呼去激活状态的PDU会话对应的终端。基于该可能的设计，可以以终端为粒度组寻呼，也可以以PDU会话为粒度组寻呼，有效且灵活的指示组寻呼的对象。
一种可能的设计中，第一信息携带在N1N2消息传输中；或者，第一信息携带在N11消息中。基于该可能的设计，有效且灵活地设计携带第一信息的载体，同时简化系统设计。
第二方面，本申请实施例还提供一种通信方法，所述方法包括：接入与移动性管理功能网元接收来自第一会话管理功能网元的包括组播会话的标识信息和/或指示信息的第一信息，指示信息用于指示组寻呼；接入与移动性管理功能网元根据第一信息组寻呼。
基于第二方面所述的方法，在组播会话激活或者去激活时，接入与移动性管理功能网元接收第一会话管理功能网元的指示，对组播会话对应的终端组寻呼，以优化组播会话对应的终端的寻呼区域，不再重叠区域重复发送寻呼消息，优化寻呼流程，降低寻呼组播群组中的终端带来的信令开销。
一种可能的设计中，指示信息包括第一指示信息或第二指示信息；其中，第一指示信息用于指示采用组寻呼方式寻呼组播会话对应的终端，或第二指示信息用于指示采用组寻呼方式寻呼去激活状态的PDU会话对应的终端。基于该可能的设计，可以以终端为粒度组寻呼，也可以以PDU会话为粒度组寻呼，有效且灵活的指示组寻呼的对象。
一种可能的设计中，第一信息携带在N1N2消息传输中；或者，第一信息携带在N11消息中。基于该可能的设计，有效且灵活地设计携带第一信息的载体，同时简化系统设计。
一种可能的设计中，接入与移动性管理功能网元根据第一信息组寻呼，包括：接入与移动性管理功能网元根据第一信息确定加入组播会话且处于CM-IDLE态的终端；接入与移动性管理功能网元根据指示信息，在加入组播会话且处于CM-IDLE态的终端的寻呼区域发送寻呼消息，寻呼消息包括组播会话的标识信息；处于CM-IDLE态的终端的寻呼区域包括处于CM-IDLE态的终端的注册区域的并集。
基于该可能的设计，不再重叠区域重复发送寻呼消息，降低寻呼带来的信令开销。
第三方面，本申请实施例提供一种通信方法，所述方法包括：接入与移动性管理功能网元接收来自第一会话管理功能网元的用于接入与移动性管理功能网元将处于CM-CONNECTED态的终端指示给/通知给第一会话管理功能网元的第二消息，根据第二消息，向第一会话管理功能网元发送第三消息；其中，第三消息包括第一终端的标识信息和/或组播会话的标识信息；第一会话管理功能网元用于管理第一终端的协议数据单元PDU会话中与组播会话关联的PDU会话，处于CM-CONNECTED态的终端包括第一终端。
基于第三方面所述的方法，第一会话管理功能网元可以指示接入与移动性管理功能网元将处于CM-CONNECTED的终端指示给第一会话管理功能网元，触发第一会话管理功能网元将用于配置组播会话对应的无线承载的相关信息发送给第一终端对应的接入网设备，保证第一终端能够正常接收组播业务的数据。或者，触发第一会话管理功能网元指示所述接入网设备释放用于向第一终端传输组播业务的数据的资源，提高资源利用率。
一种可能的设计中，第二消息包括组播会话的标识信息。基于该可能的设计，可以以组播会话为粒度，指示将加入组播会话的且处于CM-CONNECTED态的终端指示给第一会话管理功能网元，简化系统设计。
一种可能的设计中，第二消息还用于指示接入与移动性管理功能网元寻呼处于CM-IDLE态的终端。基于该可能的设计，在存在处于CM-IDLE态的终端的情况下，寻呼处于CM-IDLE态的终端，将该终端转变为CM-CONNECTED态，保证第一会话管理网元根据与该终端对应的通信接口为该终端配置无线承载的相关信息或者释放相关资源等。
一种可能的设计中，接入与移动性管理功能网元根据第二消息，向第一会话管理功能网元发送第三消息，包括：接入与移动性管理功能网元根据第二消息，寻呼已加入组播会 话且处于CM-IDLE态的终端；处于CM-IDLE态的终端包括第一终端；接入与移动性管理功能网元接收到来自第一终端的服务请求，接入与移动性管理功能网元向第一会话管理功能网元发送第三消息。
一种可能的设计中，接入与移动性管理功能网元根据第二消息寻呼处于CM-IDLE态的终端，包括：接入与移动性管理功能网元根据第二消息、以及已加入组播会话且处于CM-IDLE态的终端的注册区域中接入网设备的组播能力信息，寻呼已加入组播会话且处于CM-IDLE态的终端。
一种可能的设计中，接入与移动性管理功能网元根据第二消息、以及处于CM-IDLE态的终端的注册区域中接入网设备的组播能力信息，寻呼已加入组播会话且处于CM-IDLE态的终端，包括：若第一终端的注册区域中第一接入网设备支持组播功能，则接入与移动性管理功能网元向第一接入网设备发送寻呼消息，寻呼消息包括组播会话的标识信息，处于CM-IDLE态的终端包括第一终端；若第一终端的注册区域中第二接入网设备不支持组播功能，则接入与移动性管理功能网元向第二接入网设备发送寻呼消息，寻呼消息包括第一终端的标识信息。
基于该可能的设计，针对支持组播功能的接入网设备，向该接入网设备发送携带组播会话的标识信息的寻呼消息，以便接入网设备识别寻呼消息所包括的组播会话的标识信息，根据组播会话的标识信息对已加入组播会话且处于CM-IDLE态的多个终端发起组寻呼，节省信令开销。对于不支持组播功能的接入网设备，向该接入网设备发送携带终端的标识信息的寻呼消息，以便接入网设备根据终端的标识信息发起针对该终端的寻呼，避免因不支持组播功能的接入网设备无法识别出组播会话的标识信息，导致寻呼失败的问题。
一种可能的设计中，接入与移动性管理功能网元根据第二消息寻呼已加入组播会话且处于CM-IDLE态的终端，包括：接入与移动性管理功能网元根据第二消息，向第一终端对应的接入网设备发送第四消息，第四消息包括第一终端的标识信息和组播会话的标识信息；处于CM-IDLE态的终端包括第一终端。基于该可能的设计，便于第一终端对应的接入网设备根据自己的组播能力信息灵活地选择寻呼方式。
一种可能的设计中，接入与移动性管理功能网元根据第二消息，向第一会话管理功能网元发送第三消息，包括：接入与移动性管理功能网元接收到第二消息，如果存在处于CM-CONNECTED态的终端，则接入与移动性管理功能网元向第一会话管理功能网元发送第三消息，存在处于CM-CONNECTED态的终端包括第一终端。
基于该可能的设计，可以将处于CM-CONNECTED态的终端直接指示给第一会话管理功能网元，无需对该终端进行寻呼，简化系统设计。
第四方面，本申请实施例提供一种通信方法，所述方法包括：第一会话管理功能网元向接入与移动性管理功能网元发送用于接入与移动性管理功能网元将处于CM-CONNECTED态的终端指示给第一会话管理功能网元的第二消息；第一会话管理功能网元接收来自接入与移动性管理功能网元的第三消息；其中，第三消息包括第一终端的标识信息和/或组播会话的标识信息；第一会话管理功能网元用于管理第一终端的PDU会话中与组播会话关联的PDU会话，处于CM-CONNECTED态的终端包括第一终端。
基于第四方面所述的方法，第一会话管理功能网元可以指示接入与移动性管理功能网元将处于CM-CONNECTED的终端指示给第一会话管理功能网元，并接收接入与移动性管 理功能网元的指示，使第一会话管理功能网元获知终端的CM状态，便于第一会话管理功能网元根据终端的CM状态进行后续工作。
一种可能的设计中，所述方法还包括：第一会话管理功能网元接收来自第二会话管理功能网元的用于通知组播会话激活或者用于通知组播会话释放的第一消息，第二会话管理功能网元对应于组播会话；第一会话管理功能网元向接入与移动性管理功能网元发送第二消息包括：第一会话管理功能网元根据第一消息，向接入与移动性管理功能网元发送第二消息。基于该可能的设计，可以在组播会话激活或者组播会话释放场景下，向接入与移动性管理功能网元发送第二消息，扩大该方法的应用场景。
一种可能的设计中，第二消息包括组播会话的标识信息。基于该可能的设计，可以以组播会话为粒度，指示将加入组播会话的且处于CM-CONNECTED态的终端指示给第一会话管理功能网元，简化系统设计。
一种可能的设计中，第二消息还用于寻呼已加入组播会话且处于连接管理-空闲CM-IDLE态的终端，第二消息包括组播会话的标识信息。基于该可能的设计，在存在处于CM-IDLE态的终端的情况下，寻呼处于CM-IDLE态的终端，将该终端转变为CM-CONNECTED态，保证第一会话管理网元根据与该终端对应的通信接口为该终端配置无线承载的相关信息或者释放相关资源等。
一种可能的设计中，所述方法还包括：第一会话管理功能网元根据第三消息，向第一终端对应的接入网设备发送第二信息；其中，第二信息用于接入网设备配置用于向第一终端传输组播业务的数据的无线承载，或者第二信息用于接入网设备释放用于向第一终端传输组播业务的数据的资源。资源包含用于向第一终端传输组播业务的数据的无线承载和/或组播业务对应的组播QoS信息和/或组播QoS信息对应的单播QoS信息。
基于该可能的设计，第一会话管理功能网元可以将用于配置组播会话对应的无线承载的相关信息发送给第一终端对应的接入网设备，保证第一终端能够正常接收组播业务的数据。或者，触发第一会话管理功能网元指示所述接入网设备释放用于向第一终端传输组播业务的数据的资源，提高资源利用率。
一种可能的设计中，第二信息用于接入网设备配置用于向第一终端传输组播业务的数据的无线承载；第二信息包括以下至少一种：组播会话的标识信息，组播会话对应的组播服务质量QoS信息，组播QoS信息对应的单播QoS信息，或者组播服务质量流QoS Flow对应的单播服务质量流标识QoS Flow ID。基于该可能的设计，可以有效且灵活地设计用于接入网设备配置用于向第一终端传输组播业务的数据的无线承载的信息。
一种可能的设计中，第二信息用于接入网设备释放用于向第一终端传输组播业务的数据的资源，资源包含用于向第一终端传输组播业务的数据的无线承载、组播业务对应的组播QoS信息或组播QoS信息对应的单播QoS信息中的一种或者多种；第二信息包括以下至少一种：组播会话的标识信息，组播QoS Flow对应的单播QoS Flow ID，组播会话对应的组播服务质量QoS信息，组播QoS信息对应的单播QoS信息，或者释放指示；释放指示用于指示释放用于向第一终端传输组播业务的数据的资源。基于该可能的设计，可以有效且灵活地设计用于接入网设备释放用于向第一终端传输组播业务的数据的资源的信息。
第五方面，本申请实施例提供一种通信方法，所述方法包括：接入网设备确定组播业务对应的组播会话激活；接入网设备向第一终端对应的接入与移动性管理功能网元发送第 六消息；其中，第六消息用于指示组播会话激活，第六消息包括组播会话的标识信息，第一终端是加入组播会话的终端。
基于第五方面所示方法，可以在接入网设备激活组播会话之后，由接入网设备通过接入与移动性管理功能网元通知第一会话管理功能网元也激活组播会话，以保证网元之间维护的组播会话状态统一。同时，无需核心网网元以终端为粒度通知该终端对应的接入网设备将终端加入组播会话，降低信令开销。
一种可能的设计中，加入组播会话的终端还包括第二终端，所述方法还包括：接入网设备向第二终端对应的接入与移动性管理功能网元发送第七消息；其中，第七消息用于指示组播会话激活，第七消息包括组播会话的标识信息。基于该可能的设计，接入网设备可以向接入与移动性管理功能网元指示组播会话激活，以便接入与移动性管理功能网元通知第一会话管理功能网元组播会话激活，触发第一会话管理功能网元更新组播会话状态等。
一种可能的设计中，所述方法还包括：当接入网设备接收到来自MB-UPF的组播业务的数据时，接入网设备确定组播业务对应的组播会话激活。基于该可能的设计，可以从用户面的数据传输获知组播业务对应的组播会话激活。
一种可能的设计中，所述方法还包括：接入网设备接收来自接入与移动性管理功能网元的第八消息；其中，第八消息用于指示激活组播会话，第八消息包括组播会话的标识信息；接入网设备根据第八消息确定组播业务对应的组播会话激活。基于该可能的设计，可以从控制面的信令消息获知组播业务对应的组播会话激活。
一种可能的设计中，所述方法还包括：接入网设备根据单播服务质量QoS信息配置单播无线承载；其中，单播QoS信息与组播会话的QoS信息对应，单播无线承载用于通过PDU会话传输组播业务的数据。基于该可能的设计，可以在激活组播会话时建立用于传输组播业务的数据的PDU会话，保证组播业务的数据的正常传输。
一种可能的设计中，所述方法还包括：接入网设备接收来自第一会话管理功能网元的第九消息；其中，第九消息包含PDU会话的标识信息；第九消息用于指示去激活PDU会话；接入网设根据第九消息，保留PDU会话的上下文中与组播会话的组播QoS信息对应的单播QoS信息。基于该可能的设计，可以在去激活PDU会话时，保留组播会话的组播QoS信息对应的单播QoS信息，以便后续根据QoS信息为终端建立用于传输组播业务的数据的无线承载，保证组播业务的数据的正常传输。
一种可能的设计中，第九消息还包括组播会话的标识信息和/或第四指示信息，第四指示信息指示保留与组播会话的组播服务质量QoS信息对应的单播QoS信息；接入网设备根据第九消息，保留PDU会话的上下文中与组播会话的组播服务质量QoS信息对应的单播QoS信息，包括：接入网设备根据第四指示信息，保留PDU会话的上下文中与组播会话的组播服务质量QoS信息对应的单播QoS信息。
一种可能的设计中，接入网设备根据第九消息，保留PDU会话的上下文中与组播会话的多播服务质量QoS信息对应的单播QoS信息，包括：接入网设备确定PDU会话与组播会话关联，则接入网设备保留PDU会话的上下文中与组播会话的多播服务质量QoS信息对应的单播QoS信息。
第六方面，本申请实施例提供一种通信方法，所述方法包括：接入与移动性管理功能网元接收来自接入网设备的用于指示组播会话激活的第六消息；第六消息包括组播会话的 标识信息；接入与移动性管理功能网元根据第六消息，向第一会话管理功能网元发送第十消息；其中，第十消息用于指示组播会话激活，第十消息包括组播会话的标识信息。
基于第六方面所示方法，可以在接入网设备激活组播会话之后，由接入与移动性管理功能网元通知第一会话管理功能网元也激活组播会话，以保证网元之间维护的组播会话状态统一。同时，无需核心网网元以终端为粒度通知该终端对应的接入网设备将终端加入组播会话，降低信令开销。
一种可能的设计中，所述方法还包括：接入与移动性管理功能网元接收来自第二会话管理功能网元的组播会话激活的通知；第二会话管理功能网元对应于组播会话；接入与移动性管理功能网元根据组播会话激活的通知，向接入网设备发送第八消息；其中，第八消息用于指示激活组播会话，第八消息包括组播会话的标识信息。
第七方面，本申请实施例提供一种通信方法，所述方法包括：第一会话管理功能网元接收来自接入与移动性管理功能网元的用于指示组播会话激活的第十消息；第一会话管理功能网元根据第十消息，将组播会话的状态设置为激活态。
基于第七方面所示方法，可以在接入网设备激活组播会话之后，由接入网设备通知接入与移动性管理功能网元通知第一会话管理功能网元也激活组播会话，以保证网元之间维护的组播会话状态统一。同时，无需核心网网元以终端为粒度通知该终端对应的接入网设备将终端加入组播会话，降低信令开销。
一种可能的设计中，所述方法还包括：如果存在组播关联的PDU会话，且PDU会话的状态为去激活态，则第一会话管理功能网元激活PDU会话。
一种可能的设计中，所述方法还包括：第一会话管理功能网元确定去激活PDU会话；第一会话管理功能网元向接入网设备发送第九消息；其中，第九消息包含PDU会话的标识信息；第九消息用于指示去激活PDU会话。可选的，第九消息还包括第四指示信息和/或组播会话的标识信息，第四指示信息指示保留PDU会话的上下文中与组播会话的组播服务质量QoS信息对应的单播QoS信息。
基于该可能的设计，可以在去激活PDU会话时，保留组播会话的组播QoS信息对应的单播QoS信息，以便后续根据QoS信息为终端建立用于传输组播业务的数据的无线承载，保证组播业务的数据的正常传输。
第八方面，本申请提供一种通信装置，该通信装置可以为第一会话管理功能网元或者第一会话管理功能网元中的芯片或者片上系统，还可以为通信装置中用于实现第一方面或第一方面的任一可能的设计所述的方法的功能模块，或者实现第四方面或第四方面的任一可能的设计所述的方法的功能模块，或者实现第七方面或第七方面的任一可能的设计所述的方法的功能模块。该通信装置可以实现上述各方面或者各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。一种可能的设计中，该通信装置可以包括：处理单元，接收单元以及发送单元。
一种可能的设计中，接收单元，用于接收来自第二会话管理功能网元的第一消息，第二会话管理功能网元对应于组播会话，第一消息用于通知组播会话激活或者用于通知组播会话释放。
发送单元，用于根据第一消息，向接入与移动性管理功能网元发送第一信息，第一信 息包括组播会话的标识信息和/或指示信息，指示信息用于指示组寻呼。
又一种可能的设计中，发送单元，用于向接入与移动性管理功能网元发送第二消息；其中，第二消息用于接入与移动性管理功能网元将已加入组播会话的终端且处于连接管理-连接CM-CONNECTED态的终端指示给第一会话管理功能网元；
接收单元，用于接收来自接入与移动性管理功能网元的第三消息；其中，第三消息包括第一终端的标识信息和/或组播会话的标识信息；第一会话管理功能网元用于管理第一终端的协议数据单元PDU会话中与组播会话关联的PDU会话，处于CM-CONNECTED态的终端包括第一终端。
再一种可能的设计中，接收单元，用于接收来自接入与移动性管理功能网元的第十消息；第十消息用于指示组播会话激活，第十消息包括组播会话的标识信息。
处理单元，用于根据第十消息，将组播会话的状态设置为激活态。
具体的，该通信装置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或第四方面或第四方面的任一可能的设计所述的方法或第七方面或第七方面的任一可能的设计所述的方法中第一会话管理功能网元的行为功能，不再重复赘述。
第九方面，提供了一种通信装置，该通信装置可以为第一会话管理功能网元或者第一会话管理功能网元中的芯片或者片上系统，该通信装置包括一个或多个处理器、一个或多个存储器。所述一个或多个存储器与所述一个或多个处理器耦合，所述一个或多个存储器用于存储计算机程序代码，所述计算机程序代码包括计算机指令，当一个或多个处理器执行所述计算机指令时，使通信装置执行如第一方面或第一方面的任一种可能的设计或第四方面或第四方面的任一可能的设计所述的方法或第七方面或第七方面的任一可能的设计所述的方法。
第十方面，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，使得计算机执行第一方面或第一方面的任一种可能的设计或第四方面或第四方面的任一可能的设计所述的方法或第七方面或第七方面的任一可能的设计所述的方法。
第十一方面，提供了一种计算机可读存储介质，该计算机可读存储介质可以为可读的非易失性存储介质，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，使得计算机执行第一方面或第一方面的任一种可能的设计或第四方面或第四方面的任一可能的设计所述的方法或第七方面或第七方面的任一可能的设计所述的方法。
第十二方面，本申请提供一种通信装置，该通信装置可以为接入与移动性管理功能网元或者接入与移动性管理功能网元中的芯片或者片上系统，还可以为通信装置中用于实现第二方面或第二方面的任一可能的设计所述的方法的功能模块，或者实现第三方面或第三方面的任一可能的设计所述的方法的功能模块，或者实现第六方面或第六方面的任一可能的设计所述的方法的功能模块，或者实现第六方面或第六方面的任一可能的设计所述的方法的功能模块。该通信装置可以实现上述各方面或者各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。一种可能的设计中，该通信装置可以包括：处理单元，接收单元以及发送单元。
一种可能的设计中，接收单元，用于接收来自第一会话管理功能网元的第一信息，第一信息包括组播会话的标识信息和/或指示信息，指示信息用于指示组寻呼。
处理单元，用于根据第一信息组寻呼。
又一种可能的设计中，接收单元，用于接收来自第一会话管理功能网元的第二消息；其中，第二消息用于接入与移动性管理功能网元将处于CM-CONNECTED态的终端指示给第一会话管理功能网元。
发送单元，用于根据第二消息，向第一会话管理功能网元发送第三消息；其中，第三消息包括第一终端的标识信息和/或组播会话的标识信息；第一会话管理功能网元用于管理第一终端的协议数据单元PDU会话中与组播会话关联的PDU会话，处于CM-CONNECTED态的终端包括第一终端。
再一种可能的设计中，接收单元，用于接收来自接入网设备的第六消息；其中，第六消息用于指示组播会话激活，第六消息包括组播会话的标识信息。
发送单元1103，用于根据第六消息，向第一会话管理功能网元发送第十消息；其中，第十消息用于指示组播会话激活，第十消息包括组播会话的标识信息。
又一种可能的设计中，该通信装置可以包括：处理器和通信接口。可选的，所述通信装置还可以包括存储器，存储器，用于保存通信装置必要的计算机执行指令和数据。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实现上述方法。
具体的，该通信装置的具体实现方式可以参考第二方面或第二方面的任一种可能的设计或第三方面或第三方面的任一可能的设计所述的方法或第六方面或第六方面的任一可能的设计所述的方法或第六方面或者第六方面的任一可能的设计所述的方法中接入与移动性管理功能网元的行为功能，不再重复赘述。
第十三方面，提供了一种通信装置，该通信装置可以为接入与移动性管理功能网元或者接入与移动性管理功能网元中的芯片或者片上系统，该通信装置包括一个或多个处理器、一个或多个存储器。所述一个或多个存储器与所述一个或多个处理器耦合，所述一个或多个存储器用于存储计算机程序代码，所述计算机程序代码包括计算机指令，当一个或多个处理器执行所述计算机指令时，使通信装置执行如第二方面或第二方面的任一种可能的设计或第三方面或第三方面的任一可能的设计所述的方法或第六方面或第六方面的任一可能的设计所述的方法或第六方面或者第六方面的任一可能的设计所述的方法。
第十四方面，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，使得计算机执行第二方面或第二方面的任一种可能的设计或第三方面或第三方面的任一可能的设计所述的方法或第六方面或第六方面的任一可能的设计所述的方法或第六方面或者第六方面的任一可能的设计所述的方法。
第十五方面，提供了一种计算机可读存储介质，该计算机可读存储介质可以为可读的非易失性存储介质，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，使得计算机执行第二方面或第二方面的任一种可能的设计或第三方面或第三方面的任一可能的设计所述的方法或第六方面或第六方面的任一可能的设计所述的方法或第六方面或者第六方面的任一可能的设计所述的方法。
第十六方面，本申请提供一种通信装置，该通信装置可以为接入网设备或者接入网设备中的芯片或者片上系统，还可以为通信装置中用于实现第五方面或第五方面的任一可能的设计所述的方法的功能模块。该通信装置可以实现上述各方面或者各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。一种可能的设计中，该通信装置可以包括：处理单元，接收单元以及发送单元。
处理单元，用于确定组播业务对应的组播会话激活。
发送单元，用于向第一终端对应的接入网设备发送第六消息；其中，所述第六消息用于指示所述组播会话激活，所述第六消息包括所述组播会话的标识信息，所述第一终端是加入所述组播会话的终端。
具体的，该通信装置的具体实现方式可以参考第五方面或第五方面的任一种可能的设计所述的方法中接入网设备的行为功能，不再重复赘述。
第十七方面，提供了一种通信装置，该通信装置可以为接入网设备或者接入网设备中的芯片或者片上系统，该通信装置包括一个或多个处理器、一个或多个存储器。所述一个或多个存储器与所述一个或多个处理器耦合，所述一个或多个存储器用于存储计算机程序代码，所述计算机程序代码包括计算机指令，当一个或多个处理器执行所述计算机指令时，使通信装置执行如第五方面或第五方面的任一种可能的设计所述的方法。
第十八方面，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，使得计算机执行第五方面或第五方面的任一种可能的设计所述的方法。
第十九方面，提供了一种计算机可读存储介质，该计算机可读存储介质可以为可读的非易失性存储介质，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，使得计算机执行第五方面或第五方面的任一种可能的设计所述的方法。
第二十方面，还提供一种通信系统，该通信系统可以包括如第八方面所述的通信装置、以及如第十二方面所述的通信装置，还可以包括如第十六方面所述的通信装置。
附图说明
图1为本申请实施例提供的一种终端加入组播会话的示意图；
图2为本申请实施例提供的一种通信系统的架构示意图；
图3a为本申请实施例提供的一种5G通信系统的架构示意图；
图3b为本申请实施例提供的另一种5G通信架构示意图；
图3c为本申请实施例提供的一种组播/广播业务传输方式的示意图；
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通信方法的流程图；
图6为本申请实施例提供的一种通信方法的流程图；
图7为本申请实施例提供的一种通信方法的流程图；
图8为本申请实施例提供的一种通信方法的流程图；
图9为本申请实施例提供的一种通信方法的流程图；
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，当多个终端存在组播业务需求时，这多个终端可以加入组播会话，通过组播会话接收组播业务的数据。组播会话可以被多个终端共享，应用服务器侧可以下发一 份组播业务的数据给组播用户面功能网元(比如组播广播-用户面功能(multicast broadcast-user plane function，MB-UPF)，MB-UPF接收到组播业务的数据后，通过组播会话将组播业务的数据发送给多个终端。比如MB-UPF接收到组播业务的数据后，通过组播会话将组播业务的数据发送给接入网设备，接入网设备收到组播会话上传输的组播业务的数据，采用点到多点(point to multipoint，PTM)的方式向多个终端发送组播业务的数据，无需针对这多个终端中的每个终端均采用点到点(point to point，PTP)的方式发送组播业务的数据，提高了网络资源的利用率。
需要说明的是，本申请的“组播”是广义上的概念，可以包括组播(multicast)或广播(broadcast)，即本申请实施例既可以应用于组播业务传输，也可以应用于广播业务传输。本申请中提及的“组播”可以替换为“组播或广播”。此外，本申请中的组播会话(multicast session)可以替换为组播业务会话(multicast service session)或组播广播业务会话(multicast broadcast service session，MBS session)，不予限定。
本申请实施例中，终端加入组播会话可以替换描述为终端加入组播业务或者加入组播广播业务(multicast broadcast service，MBS)或者终端加入组播会话对应的组播群组等。
本申请实施例中，终端可以有一个或者多个协议数据单元(protocol data unit，PDU)会话，终端可以从终端的一个或者多个PDU会话中选择一个PDU会话，通过终端的该PDU会话加入组播会话。下面对终端通过终端的PDU会话加入组播会话的过程进行描述。
一种可能的设计中，终端可以通过终端的PDU会话的控制面消息(例如PDU会话建立/修改请求(PDU session establishment/modification request))加入组播群组，控制面消息携带组播会话的标识信息和加入组播群组的指示信息等。比如终端可以向终端的PDU会话对应的会话管理功能网元(本申请中可以称为第一会话管理功能网元或者单播会话管理功能网元或者SMF)发送控制面消息，终端的PDU会话对应的会话管理功能网元接收到控制面消息后，若会话管理功能网元之前没有收到所述组播业务的组播服务质量(quanlity of service，QoS)信息(或者称为组播会话对应的QoS信息)，则会话管理功能网元从多播会话管理功能网元(本申请中可以称为第二会话管理功能网元或者组播广播-会话管理功能(multicast broadcast-session management function，MB-SMF)提取组播业务的组播QoS信息。进一步可选的，多播会话管理功能网元可以与其他网元进行交互将终端加入组播会话。
又一种可能的设计中，终端可以通过终端的PDU会话的用户面通知消息(例如因特网组管理协议/组播监听者发现协议(internet group management protocol/multicast listener discovery join，IGMP/MLD join)加入组播群组，用户面通知消息携带例如组播会话的标识信息和加入组播群组的指示信息等。比如终端可以向终端的PDU会话对应的UPF发送用户面通知消息，UPF接收到用户面通知消息后，通知终端的PDU会话对应的会话管理功能网元该终端加入组播会话，终端的PDU会话对应的会话管理功能网元接收到通知，若会话管理功能网元之前没有收到组播业务的组播QoS信息，会话管理功能网元从多播会话管理功能网元提取组播业务相关的组播QoS信息。进一步可选的，多播会话管理功能网元可以与其他网元进行交互将终端加入组播会话。
本申请实施例中，组播会话的标识信息可以用于标识组播会话。组播会话的标识信息可以包括组播业务的标识信息、组播会话的上下文信息、组播业务的地址信息、组播会话关联的PDU会话的识别信息、组播业务的业务数据流(service data flow，SDF)识别规则、 组播业务的数据的分组过滤(packet filter)信息、组播业务对应的组播群组的标识信息(如组播群组的临时移动组标识(temporary mobile group identifier，TMGI)，组播/广播业务会话ID(multuicast/broadcast service session ID)，组播广播业务会话标识(MBS session ID)，组播会话ID(multicast session ID)、提供组播业务的数据的应用服务器(如AF)的因特网协议(internet protocol，IP)地址、组播业务的业务标识(service identifier，service ID)、源特定的IP组播地址(source specific IP multicast address)、组播业务的包检测规则(packets detection rule，PDR)中的一种或者多种，此处不限定。应理解，PDR是过滤器的集合，每一个过滤器是一个五元组，每一个过滤器包含组播业务的源地址、目的地址、源端口号、目标端口号、协议号，PDR用于对组播业务的数据进行过滤。
本申请实施例中，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签约永久标识(subscription permanent identifier，SUPI)、终端的用户隐藏标识(subscription concealed identifier,SUCI)、终端的一般公共订阅标识符(generic public subscription identifier,GPSI)、终端的5G短临时移动用户标识(5G S-temporary mobile subscriber identity,5G-S-TMSI)、终端的5G全球唯一临时标识(5G globally temporary identity，5G-GUTI)、终端的永久设备标识(permanent equipment identifier，PEI)、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，或者终端的国际移动用户识别码(international mobile subscriber identity，IMSI)等。应理解，该终端可以包括但不限于下述实施例中所述的第一终端、第二终端、第三终端等。
本申请实施例中，若终端的PDU会话用于终端加入组播会话，则该PDU会话可以称为(与)组播会话关联的PDU会话，该PDU会话与组播会话存在关联关系。终端通过终端的PDU会话加入组播会话后，PDU会话与组播会话之间的关联关系可以记录在终端、接入网设备以及终端的PDU会话对应的会话管理功能网元等网元上。PDU会话与组播会话之间存在关联关系可以包括下述一种或者多种：1)、PDU会话的会话管理上下文(session management context，SM context)中存储有组播会话的标识信息。2)PDU会话的SM context的标识信息指向该组播业务，如PDU会话的标识信息可以包括PDU会话的SM context的标识(indentifier，ID)，PDU会话的SM context的ID与组播会话的标识信息对应存储；3)组播业务的上下文(如，组播广播业务会话上下文(MBS session context)，或者组播广播组上下文(MBS group context)，或者组播广播业务上下文(MBS service context)，或者组播广播上下文(MBS context))中存储有组播会话关联的PDU会话的标识信息或加入组播会话的终端的标识信息。
本申请实施例中，终端的PDU会话对应的会话管理功能网元可以是建立、管理以及维护(比如，修改，释放)终端的PDU会话的会话管理功能网元。以终端的PDU会话对应的会话管理功能网元为第一会话管理功能网元为例，第一会话管理功能网元可以管理/保存/设置终端的PDU会话的状态，比如可以将终端的PDU会话的状态记录在终端的PDU会话的会话管理上下文(SM context)中的一个信元中，该信元可以是upCnxState＝DEACTIVATED/ACTIVATED。终端的PDU会话的状态可以替换描述为终端的PDU会话的用户面状态等，终端的PDU会话的状态可以包括激活态(active或activate或activated)，或者去激活态(deactivate或inactive或deactivated)。如果PDU会话是去激活态，该PDU会话对应的N3隧道和/或数据无线承载(data radio bearer，DRB)(或者称为称为无 线承载(radio bearer，RB)资源都被释放了/不可用。如果PDU会话是激活态，该PDU会话对应的N3隧道以及DRB资源都存在/可用。
本申请实施例中，终端的一个PDU会话可以对应一个会话管理功能网元，由该会话管理功能网元管理，终端的不同PDU会话可以对应不同会话管理功能网元，也可以对应相同会话管理功能网元的，不同终端的PDU会话可以对应同一会话管理功能网元。在终端的全部PDU会话处于去激活态的情况下，意味着该终端可能当前没有业务数据传输，终端可能进入连接管理-空闲(CM-IDLE)态，进入CM-IDLE态之后，终端与接入与移动性管理功能网元之间的NAS信令连接是断开的，终端不能向接入与移动性管理功能网元发送NAS信令。只要该终端的PDU会话中存在处于激活态的PDU会话，意味着该终端还有业务数据需要通过PDU会话传输，该终端可以处于连接管理-连接(CM-connceted)态。当终端处于CM-IDLE态时，如果该终端是加入组播会话的终端，当组播会话激活后，如果不寻呼CM-IDLE态的终端，则影响CM-IDLE态终端接收组播业务的数据。为了不影响终端接收组播业务的数据，可以将终端从CM-IDLE态转变为连接管理-连接(CM-connceted)态，与接入与移动性管理功能网元建立NAS信令连接，然后，第一会话管理功能网元通知接入网设备将所述终端加入组播会话，保证终端通过组播会话接收组播业务的数据。
其中，终端对应的接入与移动性管理功能网元可以是能够为该终端提供NAS信令服务的接入与移动性管理功能网元，终端的CM状态可以由该终端对应的接入与移动性管理功能网元维护，比如终端的CM状态可以保存在接入与移动性管理功能网元中终端的上下文(比如用户设备上下文(UE context))中。对于其他网元而言，无法感知/维护终端的CM状态。比如当终端的PDU会话对应的会话管理功能网元确定该PDU会话处于去激活态时，对于该会话管理功能网元而言，仅能获知该PDU会话的状态，而无法确定该终端的CM状态是CM-IDLE态还是CM-CONNECTED态。
由上可知，对于终端的PDU会话而言，终端可以通过该PDU会话加入组播会话，即终端的该PDU会话与组播会话关联。在终端的该PDU会话处于去激活态时，该终端的CM状态可以是CM-IDLE态或者CM-CONNECTED。在终端的该PDU会话处于激活态时，该终端的CM状态是CM-CONNECTED态。
例如，以UE1-UE4加入同一组播会话为例，如图1所示，UE1通过UE1的PDU会话X加入组播会话，UE2通过UE2的PDU会话Y加入组播会话，UE3通过UE3的PDU会话Z加入组播会话，UE4通过UE4的PDU会话H加入组播会话，这些PDU会话对应同一会话管理功能网元，此时，如图1所示，从会话管理功能网元来看，该会话管理功能网元中存储有组播会话与PDU会话之间的关联关系，该关联关系包括组播业务上下文中包括UE1、UE2、UE3以及UE4。同时，会话管理功能网元中维护有PDU会话X、PDU会话Y、PDU会话Z以及PDU会话H的状态，比如PDU会话X的SM context中PDU会话X状态是去激活态，PDU会话Y的SM context中PDU会话Y状态是去激活态，PDU会话Z的SM context中PDU会话Z状态是去激活态，PDU会话H的SM context中PDU会话H状态是激活态。此外，从接入与移动性管理功能网元来看，UE1-UE3处于CM-IDLE态，UE4处于CM-CONNECTED态。即从图1可知，PDU会话X、PDU会话Y和PDU会话Z处于去激活态，PDU会话X、PDU会话Y和PDU会话Z对应的UE1、UE2以及UE3处于CM-IDLE态，PDU会话H处于激活态，PDU会话H对应的UE4处于CM-CONNECTED态。
假设终端的PDU会话对应的会话管理功能网元是第一会话管理功能网元，终端通过终端的第一PDU会话加入组播会话，且第一PDU会话处于去激活态，终端可能处于CM-IDLE态或者CM-CONNECTED态。比如，当组播会话激活时，即该终端存在通过组播会话接收组播业务的数据的需求时，为了保证该终端可以正常接收组播业务的数据，则第一会话管理功能网元可以触发接入与移动性管理功能网元把加入组播会话且处于CM-IDLE态的终端寻呼回CM-CONNECTED态。又比如，对于加入组播会话的终端而言，当组播会话释放时，接入与移动性管理功能网元中终端的上下文，或终端的与该组播会话关联的PDU会话的上下文中有组播会话的相关信息需要释放掉。但是，对于加入组播会话且处于CM-IDLE态的终端而言，因该终端没有与接入与移动性管理功能网元之间的NAS信令连接，接入与移动性管理功能网元与第一会话管理功能网元都无法与该终端进行N2接口通信，所以需要把加入组播会话且处于CM-IDLE态的终端寻呼回CM-CONNECTED态，才能进一步的通过N2接口通信释放与组播会话的相关信息。
本申请实施例中，第一会话管理功能网元触发接入与移动性管理功能网元把加入组播会话且处于CM-IDLE态的终端寻呼回CM-CONNECTED态可以包括：当组播会话激活或组播会话释放时，如果该组播会话关联的PDU会话中存在处于去激活态的PDU会话，则第一会话管理功能网元以PDU会话为粒度向接入与移动性管理功能网元发送指示，指示接入与移动性管理功能网元把加入组播会话且处于CM-IDLE态的终端寻呼回CM-CONNECTED态。此时，如果组播会话关联的且处于去激活态的PDU会话较多时，则需要接入与移动性管理功能网元执行多次将处于CM-IDLE态的终端寻呼回CM-CONNECTED态的过程，信令开销加大。因此，对于加入组播会话且处于CM-IDLE态的终端，当组播会话(再次)激活或组播会话释放时，如何优化信令称为亟待解决的问题。
为优化组播会话激活或者组播会话释放时寻呼处于CM-IDLE态的终端的信令流程，本申请实施例提供一种通信方法，该方法可以包括：第一会话管理功能网元接收来自第二会话管理功能网元的第一消息(例如组播广播业务会话激活(MBS session activation或会话激活(session activation)或组播会话激活(multicast session activation)或者组播广播业务会话释放(MBS session release)或会话释放(session release)或组播会话释放(multicast session release))，第一消息可以用于通知组播会话激活/用于通知有待发送的组播业务的数据/通知组播业务的数据已到达/指示组播会话激活/指示组播会话需要重新激活或者第一消息用于通知组播会话释放；第一会话管理功能网元向接入与移动性管理功能网元发送第一信息，第一信息包括组播会话的标识信息和/或指示信息，该指示信息可以用于指示组寻呼。接入与移动性管理功能网元接收第一信息，根据组播会话的标识信息以及指示信息，对组播会话对应的组播群组中处于CM-IDLE态的终端组寻呼，比如将处于CM-IDLE态的终端的注册区域的并集(不包括重叠区域)作为组寻呼区域，在组寻呼区域发送包含组播会话的标识信息的寻呼消息，保证一次寻呼对于组播群组内多个处于CM-IDLE态的终端，以节省寻呼时的信令开销。
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通信方法可应用于图2所示的通信系统，如图2所示，该通信系统可以包括多个终端(如第一终端等)、接入网设备、接入与移动性管理功能网元、第二会话管理功能网元以及第一会话管理功能网元。进一步的，图2所示通信系统还可以包括第 一用户面功能网元、第二用户面功能网元、策略控制网元、网络存储网元、数据网络(data network，DN)，DN可以包括应用服务器(application server，AS)等。其中，第一用户面功能网元、第二会话管理功能网元、第二用户面功能网元、DN在本申请中为可选网元。
其中，多个终端可以组成一个多播群组，多个终端可以同时接收相同数据，即组播业务的数据。第一用户面功能网元可用于传输单播数据(unicast data)，也可以用于传输组播业务的数据，第二用户面功能网元可以用于传输组播业务的数据(multicast data)，单播数据可以为向某个特定终端或者用户发送的数据，组播业务的数据可以为向一个多播群组发送的数据。第一会话管理功能网元可以为管理PDU的会话管理功能网元，可以称为单播会话管理功能网元，第二会话管理功能网元可以为管理组播业务的会话管理功能网元，可以称为多播会话管理功能网元。下面对图2所示架构中涉及的网元或设备进行介绍。
终端，可以称为终端设备(terminal equipment)或者用户设备(user equipment，UE)或者移动台(mobile station，MS)或者移动终端(mobile terminal，MT)等。具体的，图1中的终端可以是手机(mobile phone)、平板电脑或带无线收发功能的电脑，还可以是虚拟现实(virtual reality，VR)终端、增强现实(augmented reality，AR)终端、工业控制中的无线终端、无人驾驶中的无线终端、远程医疗中的无线终端、智能电网中的无线终端、智慧城市(smart city)中的无线终端、智能家居、车载终端等等。
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。
接入与移动性管理功能网元，主要负责终端的接入认证、移动性管理、各个功能网元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。
会话管理功能网元，主要用于实现用户面传输逻辑通道，如：分组数据单元(packet data unit，PDU)会话或者组播会话的建立、释放和更改等会话管理功能。
用户面功能网元，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之间的数据包以及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。
策略控制网元，可以用于向接入与移动性管理功能网元、会话管理功能网元提供策略，如：服务质量(quality of service)策略，切片选择策略等等。
网络存储网元，可以用于存储用户数据，如：用户的签约信息、鉴权或授权数据等。网络存储网元可以为统一数据管理网元(unified data management，UDM)或网络存储功能(network repository function，NRF)或统一数据库(unified data repository，UDR)等。
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中可以部署有应用服务器(或者称为应用功能(application function，AF))，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2仅为示例性架构图，除图2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2中各个设备的名称不受限制，除图2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2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2所示的通信系统为图3a所示的5G通信系统为例，如图3a所示，上文第一会话管理功能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)，上文第二会话管理功能网元所对应的网元或者实体可以为5G通信系统中的组播/广播会话管理功能(multicast broadcast session management function，MB-SMF)，上文的第二用户面功能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(multicast broadcast user plane function，MB-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)、接入与移动性管理功能网元对应的网元或者实体可以为5G通信系统中的接入与移动性管理功能(access and mobility management function，AMF)、策略控制功能可以为5G通信系统中的策略控制功能(policy control function，PCF)。
需要说明的是，本申请中，SMF与MB-SMF可以合设，也可以各自独立部署，不予限制。在本申请中，UPF与MB-UPF可以合设，也可以各自独立部署，不与限制。
以图2所示的通信系统为图3b所示的5G通信系统为例，与图3a所示系统不同，图3b所示系统还可以包括组播广播业务传输功能(multicast/broadcast service transport function，MBSTF)、组播广播业务功能(multicast broadcast MBSF)。MBSTF可以具备UPF的功能，用于传输多播业务数据。MBSF可以具备MB-SMF的功能，比如建立/管理多播业务对应的多播会话等；MBSF还可以支持与LTE的MBMS进行互通等。
本申请实施例中，接入网设备不支持组播功能情况下，接入网设备与用户面功能网元之间可以以5G核心网单独组播/广播业务流量传输方式传输多播业务数据。接入网设备支持组播功能情况下，可以以5G核心网共享组播/广播业务流量传输(5GC shared MBS traffic delivery)方式传输组播业务的数据。例如，如图3c所示，5GC shared MBS traffic delivery方式下，组播业务的数据通过MB-UPF以及MB-UPF与RAN之间的N3隧道直接到达RAN，RAN可以以点到点(point to point，PTP)或点到多点(point to multi-point，PTM)的方式发送给加入组播会话的终端。5G核心网单独组播/广播业务流量传输方式，组播业务的数据通过MB-UPF到UPF，然后再通过UPF与RAN之间的N3隧道(比如终端的PDU会话)到达RAN，RAN点对点发送给终端。
接入网设备不支持组播功能可以理解为接入网设备不支持以5G核心网共享组播/广播业务流量传输(5GC shared MBS traffic delivery)方式传输组播业务的数据，也即，只支持5G核心网单独组播/广播业务流量传输(5GC Individual MBS traffic delivery)方式传输组播业务的数据，也即，组播业务的数据通过加入组播会话的终端的关联的PDU会话发送给终端。
应理解，组播业务的数据到达接入网设备(例如，RAN)之后，经过RAN的服务数据适 配协议(service data adaptation protocol，SDAP)层、分组数据汇聚协议(packet data convergence protocol，PDCP)层、无线链路控制(radio link control，RLC)层、媒体接入控制(media access control，MAC)层、物理(physical，PHY)层的处理，发送给每个接收组播业务的数据的终端。
需要说明的是，本申请中，SMF与MB-SMF可以合设，也可以各自独立部署，不予限制。在本申请中，UPF与MB-UPF可以合设，也可以各自独立部署，不与限制。
可选的，本申请实施例中的会话管理功能网元、接入网设备以及接入与移动性管理功能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功能网元、用户面功能网元、接入网设备以及接入与移动性管理功能网元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，上文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2所示各设备，如第一会话管理功能网元、接入与移动性管理功能网元等，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通信方法。例如，当通信装置400为第一会话管理功能网元或者第一会话管理功能网元中的芯 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第一会话管理功能网元所执行的步骤。又例如，当通信装置400为接入网设备或者接入网设备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接入网设备所执行的步骤。
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。
下面结合图2所示通信系统，对本申请实施例提供的通信方法进行描述。下述实施例中的各网元可以具备图4示部件，不予赘述。需要说明的是，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。例如：本申请实施例所述的多播可以替换为广播、组播、组播通信、多播/广播或者组播/广播等术语。本申请实施例中的确定也可以理解为创建(create)或生成(generate)，本申请实施例中的“包括”也可以理解为“携带”或者“包含”等，在此统一说明，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通信方法，该方法可以用于优化组播会话激活或组播会话释放时对加入组播会话的终端的寻呼流程。如图5所示，该方法可以包括：
S501：第二会话管理功能网元确定组播会话激活或者确定激活组播会话，或者第二会话管理功能网元确定组播会话释放或者确定释放组播会话。
其中，第二会话管理功能网元可以是图2中的第二会话管理功能网元，或者图3a或图3b中的MB-SMF。第二会话管理功能网元可以对应于组播会话，第二会话管理功能网元可以管理组播会话，比如第二会话管理功能网元可以建立、修改/更新或者释放组播会话等，第二会话管理功能网元还可以保存组播会话对应的组播QoS信息(或者称为组播业务相关的QoS信息等)、保存组播会话的上下文等。
本申请实施例中，组播会话可以是用于传输组播业务的数据的传输通道，组播会话包括MB-UPF到接入网设备传输隧道。执行S501的组播会话激活或激活组播会话时，组播会话处于去激活态，比如第二会话管理功能网元的组播会话上下文中组播会话的状态是去激活态。执行S501的组播会话释放或释放组播会话时，组播会话可处于激活态或者去激活态。
本申请实施例中，组播业务可以是面向组播群组或多个终端的一类业务，组播业务的数据的接收对象可以是一组终端，这些终端被授权接收此数据。比如组播业务可以是同一指挥中心发出面向一个车队的命令或者面向多个观众的一个电视节目等。
本申请实施例中，组播会话激活或者组播会话需要激活可以替换描述为组播业务的数据已到达，或者有待发送的组播业务的数据，或者组播会话的资源需要激活等等。组播会话释放或者组播会话需要释放可以替换描述为组播业务需要释放等等。
示例性的，当第二会话管理功能网元接收到来自AF/AS或MBSF或NEF的组播广播会话激活的通知(MBS session activation或session activation或multicast session activation)时，第二会话管理功能网元确定组播会话激活。或者，MB-UPF检测到组播业务的数据到达，MB-UPF通知第二会话管理功能网元组播会话激活，第二会话管理功能网元接收到MB-UPF的通知，确定组播会话激活。
示例性的，当第二会话管理功能网元接收到来自AF/AS或MBSF或NEF的组播广播会话释放的通知(MBS session release或session release或multicast session release)时，第二会话管理功能网元确定组播会话需要释放。或者，第二会话管理功能网元在确定移除组播会话配置(removal of MBS session configuration)之后，确定组播会话释放。
S502：第二会话管理功能网元向第一会话管理功能网元发送第一消息。相应的，第一会话管理功能网元接收来自第二会话管理功能网元的第一消息。
其中，第一会话管理功能网元可以为终端的PDU会话对应的SMF，终端的该PDU会话与组播会话关联，即第一会话管理功能网元可以是管理(建立、修改或者释放)组播会话关联的PDU会话的会话管理功能网元，第一会话管理功能网元可以保存PDU会话的上下文等。该PDU会话对应的终端可以是加入组播会话的终端，使用该终端的用户可以是该组播会话对应的组播群组中的成员。
其中，第一消息可以用于通知组播会话激活，或者用于通知有待发送的组播业务的数据，或者用于通知组播业务的数据已到达，或者用于指示组播会话激活，或者用于指示组播会话需要重新激活，或者用于指示/通知重新激活组播会话等。第一消息可以包含组播会话的标识信息。第一消息可以是一条N16mb消息。第一消息可以是组播会话激活的请求，比如组播广播业务激活请求(MBS activation request)，或者是组播会话激活的通知，比如组播广播业务激活通知(MBS session activation notification)或组播广播业务会话激活(MBS session activation)或会话激活(session activation)或组播会话激活(multicast session activation)等。第一消息可以直接指示(indicate)/通知(notify)激活组播会话，如第一消息可以携带一信元/指示符(indication)/通知(notification)，该信元/指示符/通知指示激活组播会话。又一种示例中，第一消息可以间接指示激活组播会话，如第一消息可以用于指示/通知组播会话启动/开始，第一消息为MBS session start/session start或组播广播业务会话激活(MBS session activation)或组播会话激活(multicast session activation)或者组播广播业务会话激活(MBS session activation)或组播会话激活(multicast session activation)或者会话激活(session activation)，或者第一消息用于指示MB-UPF检测到组播业务的数据或者组播业务的数据到达MB-UPF或者即将传输组播业务的数据或者有待传输的组播业务的数据等。
或者，第一消息可以用于通知组播会话释放，或者用于指示/通知释放组播会话等。第一消息可以包含组播会话的标识信息。第一消息可以是一条N16mb消息。第一消息可以是组播会话释放的请求(MBS session release request)，或者组播会话释放的通知(MBS session release)或会话释放(session release)或组播会话释放(multicast session release)。
示例性的，第二会话管理功能网元可以根据第一会话管理功能网元的标识信息，向第 一会话管理功能网元发送第一消息。或者第一会话管理功能网元在从第二会话管理功能网元提取所述组播会话对应的组播QoS信息时，向第二会话管理功能网元发送携带组播会话的标识信息的订阅请求，请求订阅组播会话激活(比如MBS session activation notification或MBS session activation或session activation或multicast session activation)的通知，或者请求订阅组播会话释放(比如组播广播会话释放(MBS session release)或会话释放(session release)或组播会话释放(multicast session release)的通知，后续，当第二会话管理功能网元确定组播会话激活或组播会话释放时，第二会话管理功能网元可以基于第一会话管理功能网元的订阅请求向第一会话管理功能网元发送第一消息。
其中第一会话管理功能网元的标识信息可以用于标识第一会话管理功能网元。第一会话管理功能网元的标识信息可以存储在第二会话管理功能网元，比如可以在终端通过中的PDU会话加入组播会话时，第一会话管理功能网元向第二会话管理功能网元提取组播QoS信息时，第二会话管理功能网元对应存储第一会话管理功能网元的标识信息以及组播会话的标识信息。或者第二会话管理功能网元从其他网元获取第一会话管理功能网元的标识信息，比如，第一会话管理功能网元可以向第一网元发送组播会话的标识信息，第一网元接收组播会话的标识信息，以组播业务的标识信息为索引查询组播第一对应关系，找到组播会话的标识信息对应的第一会话管理功能网元的标识信息，向第二会话管理功能网元发送第一会话管理功能网元的标识信息。
其中，第一网元可以为NRF或者UDM或者UDR或者PCF，还可以为其他具备选择MB-SMF的功能的网元，不予限制。其中，第一对应关系可以包括组播会话的标识信息与第一会话管理功能网元的标识信息之间的对应关系，第一对应关系可以预先存储在第一网元中。
S503：第一会话管理功能网元根据第一消息，确定组播会话关联的PDU会话中处于去激活态的PDU会话满足预设条件。
其中，组播会话关联的PDU会话可以是用于终端加入组播会话的PDU会话。
其中，预设条件可以包括组播会话关联的PDU会话中处于去激活态的PDU会话与组播会话关联的PDU会话的总数量的比例达到预设比例，或者预设条件包括组播会话关联的PDU会话中处于去激活态的PDU会话的数量达到预设数量门限，或者组播会话关联的PDU会话对应的终端的数量达到预设数量门限，或者组播会话对应的终端的数量达到预设数量门限，组播会话对应的终端可以包括加入组播会话的终端中由该第一会话管理功能网元提供PDU会话管理服务的终端。预设数量门限可以是大于或等于1，比如预设数量门限可以是1，也可以是2，还可以是大于2的数值等。
示例性的，第一会话管理功能网元可以以第一消息中包括的组播会话的标识信息为索引，找到该组播会话对应的组播业务的上下文，根据该组播业务的上下文包括的终端的标识信息确定加入组播会话的终端。进一步的，第一会话管理功能网元可以查看这些终端的PDU会话的上下文，如果该PDU会话的上下文中包括组播会话的标识信息，则确定该PDU会话与组播会话关联，同时根据PDU会话的上下文包括的PDU会话的用户面状态(upCnxState)信息确定PDU会话处于去激活态还是激活态。
需要说明的是，如图5所示，本申请实施例中，S503为可选步骤，可以执行S501、S502、S504以及S505优化寻呼流程，也可以执行S501-S505优化寻呼流程，不予限制。
S504：第一会话管理功能网元根据第一消息，向接入与移动性管理功能网元发送第一信息。相应的，接入与移动性管理功能网元接收来自第一会话管理功能网元的第一信息。
其中，接入与移动性管理功能网元可以是组播会话关联的PDU会话所对应的接入与移动性管理功能网元，或者是为组播会话关联的PDU会话对应的终端提供NAS信令服务的网元。接入与移动性管理功能网元作为终端的非接入层(non-access stratum，NAS)信令的终结点，用于管理/处理终端的NAS信令，比如接入与移动性管理功能网元可以负责对终端的NAS信令消息进行加密和完整性保护。
其中，第一信息可以包括组播会话的标识信息和/或指示信息。该指示信息可以用于指示组寻呼(group paging)或者指示(perform)执行组寻呼或者进行组寻呼等，或者用于指示对组播会话对应的终端组寻呼或者指示对组播会话对应的终端执行组寻呼或者指示对组播会话对应的终端进行组寻呼等。该指示信息可以包括第一指示信息或者第二指示信息。在第一信息包括组播会话的标识信息以及指示信息的情况下，可以通过指示信息显式指示组寻呼。在第一信息包括组播会话的标识信息或组播会话的标识信息的情况下，可以隐式指示组寻呼，比如可以通过第一信息的信息类型指示组寻呼。
本申请实施例中，第一指示信息可以用于指示采用组寻呼方式寻呼组播会话对应的终端，组播会话对应的终端可以是组播会话对应的终端中由该第一会话管理功能网元提供PDU会话管理服务的终端。第一指示信息可以包括组播会话对应的终端的标识信息。比如S503中第一会话管理功能网元查看组播业务的上下文确定加入组播会话的终端后，例如，确定加入组播会话的终端的数量大于或等于1，则将加入组播会话的终端的标识信息携带在第一指示信息中。此时携带组播会话的标识信息和第一指示信息的第一信息可以携带在一条N11消息中。
应注意，本申请实施例中，第一指示信息包括终端的标识信息可以替换描述为第一指示信息包括UE列表，该UE列表可以包括加入组播会话的终端的标识信息。
本申请实施例中，第二指示信息用于可以用于指示采用组寻呼方式寻呼处于去激活态的PDU会话对应的终端。一种可能的设计中，第二指示信息携带处于去激活态的关联的PDU会话对应的终端的标识信息。比如S503中第一会话管理功能网元确定组播会话关联的PDU会话中处于去激活态的关联的PDU会话后，如果处于去激活态的关联的PDU会话大于或等于1，则将这些处于去激活态的PDU会话对应的终端的标识信息携带在第二指示信息中。该可能的设计中，携带第二指示信息以及组播会话的标识信息的第一信息可以携带在一条N11消息中。应注意，该可能的设计中，第二指示信息包括处于去激活态的关联的PDU会话对应的终端的标识信息可以替换描述为第二指示信息包括UE列表，该UE列表可以包括处于去激活态的PDU会话对应的终端的标识信息。
再一种可能的设计中，第二指示信息不携带处于去激活态的PDU会话对应的终端的标识信息，仅指示接入与移动性管理功能网元组寻呼。此时接入与移动性管理功能网元可以通过下述方式获知对哪些处于去激活态的PDU会话对应终端执行组寻呼：第一会话管理功能网元确定出组播会话关联的PDU会话中处于去激活态的PDU会话满足预设条件后，比如处于去激活态的PDU会话大于或等于1后，第一会话管理功能网元向接入与移动性管理功能网元发送第一会话管理功能网元中处于去激活态的PDU会话对应的控制面信令消息，一个控制面控制消息对应一个PDU会话，该控制面信令消息可以是SMF与AMF之间的服 务接口(Namf)_通信_N1N2消息传输(Namf_Communication_N1N2Message Transfer)，该控制面信令消息可以用于指示接入与移动性管理功能网元将PDU会话对应的终端加入组播会话或者指示接入与移动性管理功能网元在PDU会话对应的终端处于CM-IDLE态时寻呼该终端或者指示接入与移动性管理功能网元将PDU会话对应的QoS配置信息发送给接入网设备。由于PDU会话与终端对应，当接入与移动性管理功能网元从第一会话管理功能网元接收到PDU会话对应的控制面信令消息，可以获知该控制面信令消息是哪个PDU会话对应的消息，进而从本地存储的PDU会话的上下文中获知该PDU会话对应哪个终端，确定将该终端加入组播会话或在该终端处于CM-IDLE态时寻呼该终端。
该再一种可能的设计中，假设组播会话关联的PDU会话中存在N个处于去激活态的PDU会话，N为大于或等于1的整数，则携带第二指示信息的第一信息可以包括在N个控制面消息中的第N个控制面消息中或者1～N中的任意一个控制面消息中，不予限制。N个控制面消息与N个处于去激活态的PDU会话一一对应，或者，第一信息携带在一条N11消息中，该N11消息可以在第一会话管理功能网元发送N个控制面消息之后发送。
例如，以图1为例，存在加入组播会话的四个UE：UE1-UE4，存在四个组播会话关联的PDU会话：PDU会话X、PDU会话Y、PDU会话Z、PDU会话H，PDU会话X对应UE1、PDU会话Y对应UE2、PDU会话Z对应UE3、PDU会话H对应UE4。PDU会话X、PDU会话Y以及PDU会话Z处于去激活态，PDU会话H处于激活态，则第一会话管理功能网元可以向接入与移动性管理功能网元发送第一信息{组播会话的标识信息，UE1-UE4}，或者第一会话管理功能网元可以向接入与移动性管理功能网元发送第一信息{组播会话的标识信息，UE1-UE3}，或者第一会话管理功能网元可以向接入与移动性管理功能网元发送PDU会话X对应的控制面信令消息X、PDU会话Y对应的控制面信令消息Y以及PDU会话Z对应的控制面信令消息Z，其中如果控制面信令消息Z是最后发送的控制面信令消息，则控制面信令消息Z中可以携带第二指示信息以及组播会话的标识信息，指示组寻呼，或者，第二指示信息也可以携带在控制面信令消息X中或控制面信令消息Y中。
S505：接入与移动性管理功能网元根据第一信息组寻呼，或者替换描述为接入与移动性管理功能网元根据第一信息执行/进行组寻呼。
一种示例中，接入与移动性管理功能网元收到第一信息后，如果第一信息包括第一指示信息，则可以根据第一指示信息包括的终端的标识信息确定处于CM-IDLE态的终端，接入与移动性管理功能网元根据处于CM-IDLE态的终端的注册区域确定组寻呼区域，组寻呼区域包括处于CM-IDLE态的终端的注册区域的并集，组寻呼区域不包括CM-IDLE态的终端注册区域中重叠的部分。接入与移动性管理功能网元向所述组寻呼区域发送寻呼消息，寻呼消息携带所述组播会话的标识信息。
再一种示例中，接入与移动性管理功能网元收到第一信息后，如果第一信息包括第二指示信息，且第二指示信息包括的处于去激活态的关联的PDU会话对应的终端的标识信息确定处于CM-IDLE态的终端，或者，如果第一信息包括第二指示信息，且第二指示信息不包括的处于去激活态的关联的PDU会话对应的终端的标识信息，接入与移动性管理功能网元可以通过去激活态的关联的PDU会话对应的控制面信令消息确定终端的标识信息，进而根据终端的标识信息确定终端是否处于CM-IDLE态。进一步的，接入与移动性管理功能网元根据处于CM-IDLE态的终端的注册区域确定组寻呼区域，组寻呼区域包括处于CM-IDLE 态的终端的注册区域的并集，组寻呼区域不包括CM-IDLE态的终端注册区域中重叠的部分。接入与移动性管理功能网元向所述组寻呼区域发送寻呼消息，寻呼消息携带所述组播会话的标识信息。本申请实施例中，携带组播会话的标识信息的寻呼消息可以称为组寻呼消息。
本申请实施例中，终端的注册区域可以由为该终端提供NAS信令服务的接入与移动性管理功能网元预先配置给终端，例如，在所述终端向所述接入与移动性管理功能网元完成注册之后，由该接入与移动性管理功能网元配置给终端。用于指示终端的注册区域的信息(本申请中可以称为终端的注册区域信息)保存在接入与移动性管理功能网元上，比如终端的注册区域信息可以保存在接入与移动性管理功能网元上该终端的上下文中，除包括终端的注册区域信息外，该终端的上下文中还可以包括终端的标识信息以及其他信息等。终端的注册区域可以是终端注册的、能够为该终端提供网络服务的区域。终端的注册区域中可以包括一个或者多个接入网设备，不予限制。终端的注册区域中包括的接入网设备可以支持组播功能，也可以不支持组播功能，不予限制。
注意，当存在处于CM-IDLE态的多个终端，且多个终端的注册区域存在相互重叠的区域(本文中可以称为重叠区域)时，为节省信令开销，接入与移动性管理功能网元可以在一个终端的重叠区域发起组寻呼即可，不用在每个终端的注册区域的重叠区域中重复发起组寻呼。比如，处于CM-IDLE态的终端包括第一终端以及第二终端，第一终端的注册区域与第二终端的注册区域中存在相互重叠的区域，接入与移动性管理功能网元可以在第一终端的注册区域中发送寻呼消息，而在第二终端的注册区域中除重叠区域之外的其他区域发起寻呼消息，如此，接入与移动性管理功能网元可以不在加入组播会话的终端中处于CM-IDLE态的每个终端的注册区域的重叠区域重复发起组寻呼，达到节省信令开销的目的。
基于图5所示方法，在组播会话关联的PDU会话中存在多个处于去激活态的PDU会话时，第一会话管理功能网元可以向接入与移动性管理功能网元发送指示信息，指示接入与移动性管理功能网元对组播会话对应的终端进行/执行组寻呼，以优化组播会话对应的终端的寻呼区域，不再重叠区域重复发送寻呼消息，优化寻呼流程，降低寻呼组播群组中的终端带来的信令开销。
可选的，由于终端的CM状态由接入与移动性管理功能网元管理，其他网元不会对终端的CM状态进行管理，即对其他网元而言，如果接入与移动性管理功能网元不告知，则不会获取到终端的CM状态。当终端的CM状态是CM-CONNECTED态时，终端可以正常接收数据，比如通过为该终端配置的用于传输组播业务的数据的无线承载接收组播业务的数据。但是，由于第一会话管理功能网元不对终端的CM状态进行管理，无法及时为CM-CONNECTED态的终端配置用于传输组播业务的数据的无线承载，进而无法保证终端正常接收组播业务的数据。为解决该问题，本申请实施例提供图6所示的通信方法。
图6为本申请实施例提供的一种通信方法，如图6所示，可以包括：
S601：第一会话管理功能网元向接入与移动性管理功能网元发送第二消息。相应的，接入与移动性管理功能网元接收来自第一会话管理功能网元的第二消息。
其中，其中，第一会话管理功能网元可以用于管理第一终端的PDU会话中与组播会话关联的PDU会话。第一会话管理功能网元可以是从多个会话管理功能网元中选择能够管理第一终端的PDU会话的会话管理功能网元。第一会话管理网元可以是图2中的第一会话管理网元或图3a中的SMF。第一会话管理功能网元可以管理终端的PDU会话。接入与移动 性管理功能网元可以对应该终端，是为该终端提供NAS信令服务的AMF。
其中，第二消息可以用于所述接入与移动性管理功能网元将处于CM-CONNECTED态的终端指示给/通知给第一会话管理功能网元。第二消息可以是一条订阅请求，该订阅请求可以用于请求将处于CM-CONNECTED态的终端的通知给第一会话管理功能网元。该终端可以是加入(jioned)(或者已加入)组播会话的终端，第二消息可以包括组播会话的标识信息，第二消息可以替换描述为触发接入与移动性管理功能网元将已加入组播会话的终端中处于CM-CONNECTED态的终端指示给/通知给第一会话管理功能网元，比如接入与移动性管理功能网元向第一会话管理功能网元发送用于指示所述终端在CM-CONNECTED态的第三消息。
可选的，在接入与移动性管理功能网元寻呼加入组播会话且处于CM-IDLE态的终端时，存在接入与移动性管理功能网元可能寻呼部分处于CM-IDLE态的终端或者可能不寻呼部分处于CM-IDLE态的终端的场景，这种场景下，会导致处于CM-IDLE态的终端未被全部寻呼，仍处于CM-IDLE态，无法保证加入组播会话的终端正常接收组播业务的数据。为解决该问题，本申请实施例中，第二消息还可以用于/指示接入与移动性管理功能网元寻呼(immediately paging或page immedialely或immediately page或paging或may page)已加入组播会话且处于CM-IDLE态的终端，即指示接入与移动性管理功能网元寻呼(可以是立即寻呼(immediately paging)或者may paging等)加入组播会话且处于CM-IDLE态的终端，避免存在可能不寻呼加入组播会话且处于CM-IDLE态的终端的问题，保证加入组播会话的终端正常接收组播业务的数据。第二消息可以包括已加入组播会话的终端的标识信息。可选的，第二消息还可以包括组播会话的标识信息。第二消息包括已加入组播会话的终端的标识信息还可以替换描述为第二消息包括UE标识列表(UE ID List或UE的标识信息(UE ID)，该UE列表可以包括已加入组播会话的终端的标识信息。
进一步可选的，当第二消息用于/指示接入与移动性管理功能网元寻呼已加入组播会话且处于CM-IDLE态的终端时，第二消息还可以包括第三指示信息，该第三指示信息可以用于指示接入与移动性管理功能网元在已加入组播会话的终端处于CM-IDLE态时寻呼(可以是立即寻呼(immediately page)或寻呼(may page)或page)已加入组播会话且处于CM-IDLE态的终端。或者第二消息不包括第三指示信息，第二消息本身就有指示接入与移动性管理功能网元寻呼寻呼已加入组播会话且处于CM-IDLE态的终端的作用，比如第二消息的消息类型(information type)/消息格式对应寻呼已加入组播会话且处于CM-IDLE态的终端的指示。
其中，第二消息可以是一条新定义的N11消息，或者第二消息可以是使能终端可达消息(Namf_MT_EnableUEReachability或MBS_MT_Reachability等)，本申请实施例不限定第二消息的信令名称。例如第二消息可以是使能终端可达请求Namf_MT_EnableUEReachability request或MBS_MT_Reachability request等。或者第二消息可以是Namf_EventExposure_Subscribe等。
本申请实施例中，寻呼已加入组播会话且处于CM-IDLE态的终端可以指接入与移动性管理功能网元收到所述第二消息后，根据第二消息携带的组播会话的标识信息以及加入组播会话的终端的标识信息定位到已加入组播会话且处于CM-IDLE态的终端；或者根据加入组播会话的终端的标识信息定位到已加入组播会话且处于CM-IDLE态的终端，寻呼所述处于CM-IDLE态的终端。
示例性的，当第一会话管理功能网元接收到来自第二会话管理功能网元的第一消息时，第一会话管理功能网元执行S601。具体的，该过程可以参照图7对应的实施例中所述。
S602：接入与移动性管理功能网元根据第二消息，向第一会话管理功能网元发送第三消息。相应的，第一会话管理功能网元接收来自接入与移动性管理功能网元的第三消息。
本申请实施例中，第三消息可以包括第一终端的标识信息和/或组播会话的标识信息。第一终端可以是处于CM-CONNECTED态的终端，即第一终端包括在处于CM-CONNECTED的终端或者处于CM-CONNECTED且加入组播会话的终端。第三消息可以用于指示处于CM-CONNECTED态的第一终端。应理解，S602之前，第一终端的CM状态可以是CM-CONNECTED态或者CM-IDLE态。第一终端的标识信息的相关描述以及组播会话的标识信息的相关描述可参照上文，不予赘述。具体的，第三消息可以是与第二消息对应的回复消息，或者第三消息可以是一条通知消息，例如，如果第一会话管理功能网元向接入与移动性管理功能网元订阅了将处于CM-CONNECTED态的终端通知给第一会话管理网元的事件，例如，对应第一会话管理功能网元的订阅消息可以为Namf_EventExposure_Subscribe)，则第三消息可以是与该订阅消息相对应的通知消息，例如针对Namf_EventExposure_Subscribe的通知消息/回复消息，比如可以是Namf_EventExposure_Notify。
其中，接入与移动性管理功能网元根据第二消息，向第一会话管理功能网元发送第三消息可以包括：接入与移动性管理功能网元根据第二消息确定终端处于CM-CONNECTED态，向第一会话管理功能网元发送第三消息。
一种示例中，S602之前，第一终端的CM状态是CM-IDLE态，接入与移动性管理功能网元根据第二消息，向第一会话管理功能网元发送第三消息可以包括：接入与移动性管理功能网元根据第二消息寻呼包括第一终端在内的处于CM-IDLE态的终端，如果接入与移动性管理功能网元接收到来自第一终端的服务请求，则根据第一终端的服务请求为第一终端建立NAS信令连接，将第一终端从CM-IDLE态转变为CM-CONNECTED态，向第一会话管理功能网元发送第三消息。具体的，该过程可以参照下述图7中S704-S706所述。
又一种示例中，S602之前，第一终端的CM状态是CM-CONNECTED态，接入与移动性管理功能网元根据第二消息，向第一会话管理功能网元发送第三消息可以包括：接入与移动性管理功能网元根据第二消息携带的组播会话的标识信息以及加入组播会话的终端的标识信息定位到已加入组播会话的终端中的第一终端处于CM-CONNECTED态；或者根据加入组播会话的终端的标识信息定位到已加入组播会话的第一终端处于CM-CONNECTED态，向第一会话管理功能网元发送第三消息。具体的，该过程参照下述图7中S707所述。
其中，上述示例中，接入与移动性管理功能网元可以根据第一会话管理功能网元的标识信息，向第一会话管理功能网元发送第三消息。其中，第一会话管理功能网元的标识信息可以用于标识第一会话管理功能网元。接入与移动性管理功能网元可以在第一终端建立组播会话关联的PDU会话时保存了第一会话管理功能网元的标识信息(例如SMF ID)。
可选的，如果加入组播会话的终端存在处于CM-IDLE态的终端，比如处于CM-IDLE态的终端包括第一终端，则接入与移动性管理功能网元接收到第二消息后，可以根据第二消息对CM-IDLE态的终端进行寻呼。例如，接入与移动性管理功能网元根据第二消息，确定处于CM-IDLE态的终端；接入与移动性管理功能网元在处于CM-IDLE态的终端的寻呼 区域发送寻呼消息，寻呼消息包括组播会话的标识信息；处于CM-IDLE态的终端的寻呼区域包括支持组播能力的接入网设备。
其中，处于CM-IDLE态的终端的寻呼区域的相关描述以及确定方式可以参照图5对应的实施例中所述，不予赘述。
进一步可选的，如图6所示，所述方法还可以包括：
S603：第一会话管理功能网元根据第三消息，向第一终端对应的接入网设备发送第二信息。相应的，第一终端对应的接入网设备接收第二信息。
其中，第二信息可以用于接入网设备配置用于传输组播业务的数据的无线承载或者用于接入网设备释放用于向第一终端传输组播业务的数据的资源，所述资源可以包含用于向第一终端传输组播业务的数据的无线承载、组播业务对应的组播QoS信息或组播QoS信息对应的单播QoS信息中的一种或者多种。
例如，第一会话管理功能网元接收到第三消息后，如果确定组播会话激活和/或第一终端的与组播会话关联的PDU会话激活，则第一会话管理功能网元向第一终端对应的接入网设备发送第二信息，第二信息可以用于所述接入网设备配置用于传输组播业务的数据的无线承载，该无线承载可以是组播无线承载和/或单播无线承载或无线承载。
又例如，第一会话管理功能网元接收到第三消息后，如果确定组播会话释放和/或第一终端的与组播会话关联的PDU会话去激活，则第一会话管理功能网元向第一终端对应的接入网设备发送第二信息，第二信息可以用于所述接入网设备释放用于向第一终端传输组播业务的数据的资源，所述资源包含用于向第一终端传输组播业务的数据的无线承载、组播业务对应的组播QoS信息、所述组播QoS信息对应的单播QoS信息中的一种或者多种。
应注意，对于是MBS session activation的情况。第一会话管理网元收到第三消息，可选的，当组播关联的PDU会话去激活时，接入网设备中保留了组播会话对应的组播QoS信息对应的单播QoS信息，并且单播QoS信息不需要更新时，第一会话管理功能网元可以不向第一终端对应的接入网设备发送第二信息。可选的，当组播关联的PDU会话去激活时，接入网设备中没保留组播会话对应的组播QoS信息对应的单播QoS信息，第一会话管理功能网元可以/需要向第一终端对应的接入网设备发送第二信息。可选的，当组播会话关联的PDU会话去激活时，接入网设备中保留了组播会话对应的组播QoS信息对应的单播QoS信息，并且单播QoS信息需要更新时，第一会话管理功能网元可以/需要向第一终端对应的接入网设备发送第二信息。
还应注意，对于是MBS session release的情况，第一会话管理网元收到第三消息后，第一会话管理功能网元可以/需要向第一终端对应的接入网设备发送第二信息。
一种示例中，第二信息用于接入网设备配置用于传输组播业务的数据的无线承载。第二信息包括以下至少一种，组播会话的标识信息，组播会话对应的组播服务质量QoS信息，组播QoS信息对应的单播QoS信息，或者组播服务质量流QoS Flow对应的单播QoS Flow ID。或者，第二信息包括以下至少一种：组播会话对应的QoS配置信息(QoS profile)，QoS配置信息可以包含组播会话对应的组播QoS信息(或者称为组播QoS配置信息(multicast QoS profile))和/或组播会话对应的组播QoS信息对应的单播QoS信息。第二信息可以包含在N2 SM信息(N2 SM Information)中或者第二信息可以是N2 SM Information，第二信息由第一会话管理功能网元发送给接入网设备，其用于接入网设备根据第二信息息分配传输组 播业务的数据的无线承载(比如数据无线承载(data radio bearer，DRB)或者组播无线承载(multicast radio bearer，MRB)。
又一种示例中，第二信息用于接入网设备释放用于向第一终端传输组播业务的数据的资源。第二信息可以包括下述一种或者多种：组播会话的标识信息，组播QoS Flow对应的单播QoS Flow ID，组播会话对应的组播服务质量QoS信息，组播QoS信息对应的单播QoS信息，或者释放指示；释放指示用于指示释放组播会话对应的组播QoS信息和/或组播会话对应的组播QoS信息对应的单播QoS信息。
本申请实施例中，组播会话对应的组播QoS信息(例如，组播QoS配置信息(QoS Profile))可以用于建立或者指示组播会话中用于传输组播业务的传输资源。具体来说，组播QoS信息可以用于接入网设备配置组播会话对应的DRB或MRB或RB。组播QoS信息可以包括下述一种或者多种：组播QoS flow的标识信息(比如组播QFI)、组播QoS flow对应的QoS参数(例如，QoS profile，包括但不限于5QI，ARP，session-AMBR等)、组播QF对应的隧道信息。组播QoS flow可以为第一终端的PDU会话包括的用于传输组播业务的数据的QoS flow。组播QoS flow对应的隧道信息可以用于标识通过组播传输模式向第一终端传输组播业务的数据的隧道。
本申请实施例中，组播QoS信息对应的单播QoS信息可以用于建立或者指示组播业务对应的单播会话中(也即组播会话关联的PDU)用于传输组播业务的传输资源。具体来说，组播QoS信息对应的单播QoS信息可以用于建立某个单播QoS流(QoS Flow，QF)，或者是用于指示已建立的单播QF中可以用于传输组播业务的数据的QF。该单播会话与第一终端对应，该单播会话可以称为第一终端的PDU会话，该第一终端的PDU会话用于传输组播业务的数据。组播QoS信息对应的单播QoS信息可以包括下述一种或者多种：单播QF的标识信息(比如单播QFI)、单播QF对应的QoS参数(例如QoS profile，包括但不限于5QI，ARP，session-AMBR等)。
示例性的，第一会话管理功能网元根据第三消息，向第一终端对应的接入网设备发送第二信息可以包括：第一会话管理功能网元根据第三消息携带的第一终端的标识信息找到第一终端的与组播会话关联的PDU会话的上下文，从第一终端的PDU会话的上下文中获取组播QoS信息对应的单播QoS信息，和/或根据第三消息携带的组播会话的标识信息找到组播会话的上下文，从组播会话的上下文中获取组播会话对应的组播QoS信息，将组播会话的标识信息、组播会话对应的组播QoS信息以及组播QoS信息对应的单播QoS信息以及释放所述组播会话对应的组播QoS信息和/或所述组播会话对应的组播QoS信息对应的单播QoS信息的指示等一种或者多种信息携带在第二信息中，向第一终端对应的接入网设备发送第二信息。
本申请中，第一会话管理功能网元根据第三消息，向第一终端对应的接入网设备发送第二信息可以包括：第一会话管理功能网元将第二信息携带在N2 SM消息(N2 SM Information)中或者第二信息可以是N2 SM Information，将第二信息携带在N1N2消息(比如Namf_Communication_N1N2MessageTransfer)或者PDU会话更新会话管理上下文响应(Nsmf_PDUSession_UpdateSMContext response)中发送给接入与移动性管理功能网元，接入与移动性管理功能网元获取到N2 SM消息，将N2 SM消息携带在N2消息中发送给接入网设备，触发接入网设备配置传输组播业务的数据的无线承载或者释放用于向第一终端传 输组播业务的数据的资源。
其中，N2 SM消息可以与第一终端对应。当第二信息用于指示配置用于传输组播业务的数据的无线承载时，该N2 SM消息可以是与第一终端的PDU会话对应的PDU会话资源建立请求或响应(PDU session resource setup request/response)或PDU会话资源修改请求或响应(PDU session resource modify request/esponse)。
当第二信息用于所述接入网设备释放用于向第一终端传输组播业务的数据的资源时，N2 SM消息可以是与第一终端的PDU会话对应的PDU会话资源建立请求或响应(PDU session resource setup request/response)或PDU会话资源修改请求或响应(PDU session resource modify request/esponse)。进一步的，第一终端对应的接入网设备接收到第二信息后，可以根据第二信息配置用于传输组播业务的数据的无线承载，或者释放所述组播会话对应的资源，将第一终端从组播会话中移除、释放组播QoS信息对应的单播QoS信息等。
应注意，上述N2 SM Information可以是PDU会话资源建立请求传输(PDU session resource setup request transfer)或PDU会话资源建立回复传输(PDU session resource setup Response Transfer)或PDU会话资源修改请求传输(PDU session resource modify request transfer)或PDU会话资源修改回复传输(PDU session resource modify response transfer)或PDU会话资源通知传输(PDU session resource notify transfer)或PDU会话资源修改指示传输(PDU session resource modify indication transfer)或PDU会话资源修改确认传输(PDU session resource modify confirm transfer)或PDU会话资源释放命令传输(PDU session resource release command transfer)或PDU会话资源通知释放传输(PDU session resource notify released transfer)或者PDU会话资源释放回复传输(PDU session resource release response transfer)，不限定。
基于图6所示方法，第一会话管理功能网元可以指示接入与移动性管理功能网元将处于CM-CONNECTED的终端指示给第一会话管理功能网元，触发第一会话管理功能网元将用于配置组播会话对应的无线承载的相关信息发送给第一终端对应的接入网设备，使得第一终端对应的接入网设备配置组播会话对应的无线承载和/或组播会话关联的PDU会话对应的无线承载，保证第一终端能够正常接收组播业务的数据。或者，触发第一会话管理功能网元指示所述接入网设备释放用于向第一终端传输组播业务的数据的资源，所述资源包含用于向第一终端传输组播业务的数据的无线承载和/或组播业务对应的组播QoS信息和/或所述组播QoS信息对应的单播QoS信息。
图7为本申请实施例提供的一种通信方法，如图7所示，可以包括：
S701：第二会话管理功能网元确定组播会话激活或者确定激活组播会话；或者第二会话管理功能网元确定组播会话释放或者确定释放组播会话。
其中，S701与S501相同，不予赘述。
S702：第二会话管理功能网元向第一会话管理功能网元发送第一消息。相应的，第一会话管理功能网元接收来自第二会话管理功能网元的第一消息。
其中，第一消息的相关描述以及S702的执行过程可参照S502中所述，不予赘述。
S703：第一会话管理功能网元根据第一消息，向接入与移动性管理功能网元发送第二消息。相应的，接入与移动性管理功能网元接收来自第一会话管理功能网元的第二消息。
其中，第二消息的相关描述以及S703的执行过程与S601相同，不予赘述。
进一步的，接入与移动性管理功能网元接收来自第一会话管理功能网元的第二消息之 后，对于加入组播会话的终端中处于CM-IDLE态的终端或者对于处于CM-IDLE态的终端，执行S704-S706。对于加入组播会话的终端中处于CM-CONNECTED态的终端或者对于处于CM-CONNECTED态的终端，直接执行S707。
应注意，本申请实施例中，接入与移动性管理功能网元可以不感知终端是否加入组播会话，也可以感知终端是否加入组播会话。感知终端加入组播会话是指接入与移动性管理功能网元知道终端是否在组播会话对应的组播群组中，例如，当接入网设备存储组播会话的上下文(比如MBS session context)时，接入与移动性管理功能网元可以感知终端加入组播会话，此时，接入与移动性管理功能网元可以感知终端加入组播会话，且可以感知加入组播会话的终端的CM状态；反之，当接入与移动性管理功能网元不存储组播会话的上下文(比如MBS session context)时，接入与移动性管理功能网元不感知终端加入组播会话，此时，接入与移动性管理功能网元不感知终端加入组播会话，但可以感知终端的CM状态。
本申请实施例中，以接入与移动性管理功能网元可以感知终端加入组播会话为例，对于接入与移动性管理功能网元而言，已加入组播会话且处于CM-IDLE态的终端可以包括一个终端或者多个终端，比如包括第一终端、第三终端等等。已加入组播会话且处于CM-IDLE态的终端可以指已加入组播会话且与接入与移动性管理功能网元之间不存在NAS信令连接，无法向接入与移动性管理功能网元发送NAS信令的终端。其中终端可以通过终端的PDU会话加入组播会话。具体的，通过PDU会话加入组播会话的方式可参照上文，不予赘述。已加入组播会话且处于CM-CONNECTED态的终端也可以包括一个终端或者多个终端，比如包括第二终端、第四终端等。
S704：接入与移动性管理功能网元根据第二消息，寻呼处于CM-IDLE态的终端。
其中，处于CM-IDLE态的终端可以包括一个终端或者多个终端，比如包括第一终端、第二终端等等。以第一终端为例，第一终端可以是图2中的任一终端。第一终端可以通过接入与移动性管理功能网元完成网络注册，由该接入与移动性管理功能网元为第一终端提供NAS信令服务。当第一终端存在加入组播业务的需求/组播业务需求时，第一终端还可以通过该接入与移动性管理功能网元向第一会话管理功能网元发送PDU会话建立请求/PDU会话修改请求(PDU session modification request/PDU session establishment request)，PDU会话建立请求/PDU会话修改请求可以携带第一终端的PDU会话的标识信息以及组播会话的标识信息，以触发第一会话管理功能网元根据组播会话的标识信息将第一终端加入组播会话。PDU会话建立请求可以用于请求建立第一终端的PDU会话，PDU会话修改请求可以用于请求修改第一终端的PDU会话，即通过PDU会话建立流程或者PDU会话建立流程将第一终端加入组播会话，此时，第一终端的PDU会话与组播会话关联，第一终端的PDU会话可以用于第一终端加入组播会话。
其中，第一终端完成网络注册后，接入与移动性管理功能网元中可以存储有第一终端的上下文(比如UE context)，第一终端的上下文中包括第一终端的CM状态信息，CM状态信息可以用于指示第一终端处于CM-IDLE态还是CM-CONNECTED态。本申请实施例中，接入与移动性管理功能网元可以根据第一会话管理功能网元发送的信息获知第一终端加入组播会话，比如第一会话管理功能网元可以向接入与移动性管理功能网元发送携带组播会话的标识信息以及UE列表的第二消息，接入与移动性管理功能网元接收第二消息，如果根据第二消息确定UE列表中包括第一终端的标识信息，则确定第一终端加入组播会话。接入 与移动性管理功能网元获知第一终端加入组播会话之后，可以查看第一终端的上下文，如果第一终端的上下文中CM状态信息指示第一终端处于CM-CONNECTED态，则可以直接根据第一终端的上下文包括的CM状态信息确定第一终端处于CM-CONNECTED态还是CM-IDLE态，进而寻呼处于CM-IDLE态的终端。
一种示例中，接入与移动性管理功能网元可以根据第二消息、以及已加入组播会话且处于CM-IDLE态的终端的注册区域中接入网设备的组播能力信息，(立即)寻呼已加入组播会话且处于CM-IDLE态的终端。比如接入与移动性管理功能网元可以根据第二消息携带的组播会话的标识信息确定已加入组播会话的终端，或者根据组播会话的标识信息以及加入组播会话的终端的标识信息确定已加入组播会话的终端，或者根据加入组播会话的终端的标识信息确定已加入组播会话的终端，或者根据加入组播会话的终端的标识列表确定已加入组播会话的终端。针对已加入组播会话的终端，查看接入与移动性管理功能网元保存的该终端的上下文中终端的CM状态，如果终端的CM状态为CM-IDLE态，则从该终端的上下文中获取终端的注册区域信息，根据终端的注册区域信息获知该终端的注册区域中包括的接入网设备，进而根据终端的注册区域包括的接入网设备的组播能力信息确定向接入网设备发送携带组播会话标识信息的寻呼消息还是发送携带终端的标识信息的寻呼消息。
其中，终端的注册区域(registration area)的相关描述可参照图5对应的实施例中所述，不予赘述。终端的注册区域中可以包括一个或者多个接入网设备，终端的注册区域所包括的接入网设备中有支持组播功能的接入网设备和/或不支持组播功能的接入网设备。
本申请实施例中，接入网设备的组播能力信息可以用于指示接入网设备是否支持组播功能或者指示接入网设备是否具备组播能力。支持组播功能的接入网设备能够识别组播会话的标识信息，不支持组播功能的接入网设备无法识别组播会话的标识信息。接入网设备具备组播能力可以指接入网设备具备下面功能的一项或多项：该接入网设备支持通过图3c所示的5GC shared MBS traffic delivery方法传输组播业务的数据，支持与核心网控制面网元针对组播业务的信令面交互的增强，支持接收来自核心网用户面功能网元的组播业务的数据，支持本地处理组播业务的数据，支持空口通过点对多点发送组播业务的数据以及配置响应终端接收组播业务的数据。接入网设备不具备组播能力可以指接入网设备不支持通过图3c所示5GC shared MBS traffic delivery方式传输组播业务的数据，仅支持通过图3c所示5GC Individual MBS traffic delivery方式传输组播业务的数据。比如接入网设备的能力信息可以包括接入网设备具体组播能力或者接入网设备不具备组播能力，还可以包括与接入网设备的组播能力对应的一个指示信息，该指示信息指示接入网设备的组播能力，比如指示信息可以为二进制比特0或1，如果指示信息为二进制比特0，则表示接入网设备具备组播能力，如果指示信息为二进制比特1，则表示接入网设备不具备组播能力。
一种可能的设计中，接入网设备的组播能力信息可以在接入网设备和/或接入与移动性管理功能网元上电(或者说设备部署入网开始工作)时由接入与移动性管理功能网元从接入网设备获取。比如，当接入与移动性管理功能网元和/或接入网设备上电时，接入与移动性管理功能网元和接入网设备交互各自的配置信息，该配置信息可以包括接入网设备的组播能力信息、接入与移动性管理功能网元的能力信息、接入网设备的负载信息等。接入网设备的组播能力信息如上所述。接入与移动性管理功能网元的能力信息可以用于指示该接入与移动性管理功能网元是否支持为加入组播会话的终端提供NAS信令服务，接入网设备 的负载信息可以用于指示接入该接入网设备的终端的个数等。
又一种可能的设计中，接入与移动性管理功能网元通过网管(比如操作、管理与维护(operations、administration and maintenance，OAM))发送的预配置信息获取接入网设备的组播能力信息。比如网管可以在接入网设备入网时获取接入网设备的组播能力信息，将接入网设备的组播能力信息携带在预配置信息中预先配置给接入与移动性管理功能网元。
具体的，以加入组播会话且处于CM-IDLE态的终端包括第一终端和第二终端为例，接入与移动性管理功能网元根据第二消息、以及已加入组播会话且处于CM-IDLE态的终端的注册区域中接入网设备的组播能力信息，(立即)寻呼已加入组播会话且处于CM-IDLE态的终端可以包括：
若第一终端的注册区域中第一接入网设备支持组播功能，则接入与移动性管理功能网元向第一接入网设备发送寻呼消息，该寻呼消息包括组播会话的标识信息；和/或，若第一终端的注册区域中第二接入网设备不支持组播功能，则接入与移动性管理功能网元向第二接入网设备发送寻呼消息，寻呼消息包括第一终端的标识信息，即进行UE粒度的寻呼。
应理解，如果第二终端的注册区域也包括第一接入网设备，第一终端与第二终端不同，则向第一接入网设备发送一次包括组播会话的标识信息的寻呼消息消息即可，无需向第一接入网设备多次发送寻呼消息，以降低信令开销。
即针对支持组播功能的接入网设备，向该接入网设备发送携带组播会话的标识信息的寻呼消息，以便接入网设备识别寻呼消息所包括的组播会话的标识信息，根据组播会话的标识信息对已加入组播会话且处于CM-IDLE态(比如RRC_inactive态或者RRC_IDLE态)的多个终端发起组寻呼，节省信令开销。对于不支持组播功能的接入网设备，向该接入网设备发送携带终端的标识信息的寻呼消息，以便接入网设备根据终端的标识信息发起针对该终端的寻呼，避免因不支持组播功能的接入网设备无法识别出组播会话的标识信息，导致寻呼失败的问题。
例如，以接入网设备为基站、终端为UE、接入与移动性管理功能网元为AMF为例，处于CM-IDLE态的UE1、UE2被预先分配注册区域，UE1的注册区域包含1号基站、2号基站、以及3号基站，UE2的注册区域包含2号基站、3号基站以及4号基站。假如2号基站、以及3号基站支持组播功能，1号基站以及4号基站不支持组播功能，则AMF向会2号基站、以及3号基站发送携带组播会话的标识信息的寻呼消息，以便2号基站、以及3号基站进行针对UE1以及UE2的组寻呼。对于1号基站以及4号基站，则AMF向1号基站发送携带UE1的标识信息的寻呼消息、向4号基站发送携带UE2的标识信息的寻呼消息。
再一种示例中，接入与移动性管理功能网元根据第二消息寻呼已加入组播会话且处于CM-IDLE态的终端可以包括：接入与移动性管理功能网元根据第二消息，向已加入组播会话且处于CM-IDLE态的终端的注册区域中接入网设备发送第四消息；第四消息包括已加入组播会话且处于CM-IDLE态的终端的标识信息以及组播会话的标识信息。比如，假设已加入组播会话且处于CM-IDLE态的终端包括第一终端，则第四消息可以包括第一终端的标识信息以及组播会话的标识信息。
其中，所述第四消息可以用于接入网设备寻呼已加入所述组播会话且处于CM-IDLE态的终端中由该接入网设备提供网络服务的终端，比如触发接入网设备根据第四消息以及接入网设备的组播能力信息寻呼已加入组播会话且处于CM-IDLE态的终端中由该接入网设备 提供网络服务的终端。
本申请实施例中，接入网设备根据第四消息以及接入网设备的组播能力信息，寻呼已加入组播会话且处于CM-IDLE态的终端中由该接入网设备提供网络服务的终端可以包括：如果接入网设备支持组播功能，则该接入网设备识别出第四消息中的组播会话的标识信息，该接入网设备在其覆盖的信号范围内只发一条寻呼消息就行，降低寻呼的信令开销。如果接入网设备不支持组播功能，则该接入网设备无法识别出第四消息中包括的组播会话的标识信息，该接入网设备根据第四消息携带的终端的标识信息在其覆盖区域发送一条或多条针对per UE的寻呼消息，该寻呼消息可以包括终端的标识信息。
例如，以接入网设备为基站、终端为UE为例，加入组播会话且处于非激活态的CM-IDLE态的终端包括UE1-UE4，UE1与UE2在1号基站下、UE3与UE4在2号基站下,1号基站支持组播功能，2号基站不支持组播功能，则1号基站与2号基站接收到第四消息后，1号基站发送携带组播会话的标识信息的寻呼消息，实现针对UE1以及UE2的组寻呼，而2号基站接收到第四消息后，发送携带UE3的标识信息的寻呼消息和携带UE4的标识信息的寻呼消息。
进一步的，如图7所示，已加入组播会话的终端(比如第一终端)接收到寻呼消息后，如果终端发现与组播会话关联的PDU会话处于去激活态或者终端确定自己存在组播业务需求或者根据现有技术需要进行寻呼消息的回复(paging response)，则终端通过终端对应的接入网设备，向接入与移动性管理功能网元发起/发送服务请求(service request)。
以第一终端为例，如图7所示，所述方法还可以包括：
S705：第一终端发现与组播会话关联的PDU会话处于去激活态或者第一终端确定自己存在组播业务需求或者根据现有技术需要进行寻呼消息的回复(paging response)，则第一终端通过第一终端对应的接入网设备，向接入与移动性管理功能网元发起/发送服务请求(service request)。相应的，接入与移动性管理功能网元接收服务请求。
其中，服务请求可以用于建立第一终端与接入与移动性管理功能网元之间的NAS信令连接，服务请求可以包括第一终端的标识信息。
S706：接入与移动性管理功能网元根据服务请求建立第一终端与接入与移动性管理功能网元之间的NAS信令连接，将第一终端从CM-IDLE态转变为(switch to)CM-CONNECTED态，向第一会话管理功能网元发送第三消息。相应的，第一会话管理功能网元接收来自接入与移动性管理功能网元的第三消息。
其中，第三消息的相关描述以及S707的执行过程与S602相同，不予赘述。
S707：接入与移动性管理功能网元根据第二消息，如果存在处于CM-CONNECTED态的第一终端(或者描述第一终端处于CM-CONNECTED态)，则直接向第一会话管理功能网元发送第三消息。相应的，第一会话管理功能网元接收来自接入与移动性管理功能网元的第三消息。
其中，第三消息的相关描述以及S707的执行过程与S602相同，不予赘述。
S708：第一会话管理功能网元根据第三消息，向第一终端对应的接入网设备发送第二信息。相应的，第一终端对应的接入网设备接收第二信息。
其中，第二信息的相关描述以及S708的执行过程与S603相同，不予赘述。
上述以第一终端为例进行描述，类似的，对于其他终端也可以参照上述。比如对于加 入组播会话的第二终端，如果第二终端的与组播会话关联的PDU会话也有第一会话管理功能网元管理，则第二终端对应的接入与移动性管理功能网元接收到第二消息后，发现第二终端也处于CM-IDLE态，第二终端对应的接入与移动性管理功能网元也可以参照上述S704-S706先寻呼第二终端，待第二终端处于CM-CONNECTED态后向第一接入网设备发送第五消息，第五消息可以包括第二终端的标识信息和/或组播会话的标识信息，以触发第一会话管理网元指示第二终端对应的接入网设备配置用于向第二终端传输组播业务的数据的无线承载或释放用于向第二终端传输组播业务的数据的资源等。或者，第二终端对应的接入与移动性管理功能网元接收到第二消息后，如果发现第二终端处于CM-CONNECTED态，则第二终端对应的接入与移动性管理功能网元也可以参照上述S707直接将处于CM-CONNECTED态的第二终端指示给/通知给第一会话管理网元，触发第一会话管理网元指示第二终端对应的接入网设备配置用于向第二终端传输组播业务的数据的无线承载或释放用于向第二终端传输组播业务的数据的资源等。
基于图7所示方法，可以在接入与移动性管理功能网元确定加入组播会话的终端处于CM-CONNECTED态时，接入与移动性管理功能网元触发第一会话管理功能网元将用于配置组播会话对应的无线承载的相关信息发送给第一终端对应的接入网设备，使得第一终端对应的接入网设备配置组播会话对应的无线承载和/或组播会话关联的PDU会话对应的无线承载，保证第一终端能够正常接收组播业务的数据。或者，可以在接入与移动性管理功能网元确定加入组播会话的终端处于CM-CONNECTED态时，接入与移动性管理功能网元将处于CM-CONNECTED的终端指示第一会话管理功能网元，触发第一会话管理功能网元指示所述接入网设备释放用于向第一终端传输组播业务的数据的资源，所述资源包含用于向第一终端传输组播业务的数据的无线承载和/或组播业务对应的组播QoS信息和/或所述组播QoS信息对应的单播QoS信息。
可选的，通信系统中，在组播会话激活时由核心网设备通知接入网设备配置无线承载，此时，如果存在多个终端，则需要多次通知接入网设备配置无线承载，增加信令开销。为解决该问题，本申请实施例中，还可以触发接入网设置获知组播会话激活，以组播会话为粒度建立无线承载，降低开销，同时待接入网设备激活组播会话后，通知核心网设备组播会话激活，保证组播会话状态一致。具体的，该方法可以参照图8对应的实施例。
图8为本申请实施例提供的一种通信方法，如图8所示，可以包括：
S801：接入网设备确定组播业务对应的组播会话激活。
其中，执行S801时组播会话处于去激活态。具体的，组播业务以及组播会话的相关描述可参照上文，不予赘述。接入网设备可以是图2所示系统中支持组播功能的接入网设备。
如图8所示，本申请实施例中，接入网设备根据方式一或者方式二确定组播会话激活：
方式一、当接入网设备接收到来自MB-UPF的组播业务的数据时，接入网设备确定激活组播业务对应的组播会话。
方式一中，组播会话去激活时，组播会话对应的MB-UPF与接入网设备之间的N3mb隧道没有释放。当接入网设备从该N3mb隧道收到数据时，接入网设备可以根据该N3mb隧道的隧道信息与组播会话的标识信息之间的对应关系确定从该N3mb隧道收到数据是组播会话对应的组播业务的数据，进而确定激活组播会话。
方式二、接入网设备接收来自接入与移动性管理功能网元的第八消息；其中，第八消 息可以用于指示激活组播会话，第八消息可以包括组播会话的标识信息；接入网设备根据第八消息可以确定组播业务对应的组播会话需要激活。
其中，第八消息可以是N2消息，该N2消息是以节点(比如接入网设备)为粒度的消息，即N2消息是一条per node的消息。
其中，第二会话管理功能网元收到AF/AS或MBSF或NEF的组播会话激活的通知(MBS session activation)，或者是MB-UPF检测到组播业务的数据到达，通知第二会话管理功能网元组播会话激活之后，第二会话管理功能网元可以确定接入与移动性管理功能网元的标识信息，根据接入与移动性管理功能网元的标识信息向接入与移动性管理功能网元发送组播会话激活的通知，该通知可以是一条N11mb消息，该N11mb消息可以包含组播会话的标识信息。可选的，N11mb消息还可以包含为组播会话准备/配置组播无线承载的指示/通知。接入与移动性管理功能网元接收到N11mb消息后，向接入网设备发送第八消息。
其中，该接入与移动性管理功能网元可以是为加入组播会话的终端提供NAS信令服务的AMF，也可以是为组播会话服务的AMF。本申请实施例中，第二会话管理功能网元从第一网元获知接入与移动性管理功能网元的标识信息，比如第二会话管理功能网元可以向第一网元发送组播会话的标识信息，第一网元接收组播会话的标识信息，查找能够为该组播会话服务的接入与移动性管理功能网元，并将接入与移动性管理功能网元的标识信息发送给第二会话管理功能网元。或者还可以在组播会话建立时，第二会话管理功能网元存储了接入与移动性管理功能网元的标识信息。
其中，第一网元可以为NRF或者UDM或者UDR或者PCF，还可以为其他存储有接入与移动性管理功能网元的标识信息的网元，不予限制。其中，第一网元中保存有接入与移动性管理功能网元的标识信息与组播会话的标识信息之间的对应关系。
进一步的，接入网设备确定组播业务对应的组播会话激活之后，接入网设备可以激活组播会话对应的组播会话，比如接入网设备根据组播会话对应的组播QoS信息配置组播无线承载，组播无线承载可以用于传输组播业务的数据。
其中，组播会话对应的组播QoS信息的相关描述如图7对应的实施例中所述，不予赘述。组播会话对应的组播QoS信息在去激活组播会话时未被接入网设备释放，组播会话对应的组播QoS信息保留在接入网设备中，比如保留在接入网设备中组播会话的上下文中。
S802：接入网设备向加入组播会话的终端所对应的接入与移动性管理功能网元发送消息，该消息可以用于指示组播会话激活，以便于接入与移动性管理功能网元通知第一会话管理功能网元组播会话激活，触发第一会话管理功能网元将组播会话的状态设置为激活态。
其中，S802中加入组播会话的终端可以指加入组播会话且由该接入网设备提供网络服务的终端。加入组播会话且由该接入网设备提供网络服务的终端可以包括一个或者多个终端，接入网设备可以向加入组播会话且由该接入网设备提供网络服务的每个终端对应的接入与移动性管理功能网元发送指示组播会话激活的消息。
比如，加入组播会话的终端包括第一终端，接入网设备可以向第一终端对应的接入与移动性管理功能网元发送第六消息，相应的，第一终端对应的接入与移动性管理功能网元接收第六消息。其中，第六消息可以用于指示组播会话激活，第六消息可以包括组播会话的标识信息。第六消息可以是与第一终端对应的N2消息。
又比如，加入组播会话的终端还包括第二终端，接入网设备可以向第二终端对应的接 入与移动性管理功能网元发送第七消息，相应的，第二终端对应的接入与移动性管理功能网元接收第七消息。其中，第七消息可以用于指示组播会话激活，第七消息可以包括组播会话的标识信息。第七消息可以是与第二终端对应的N2消息。
示例性的，接入网设备可以以组播会话的标识信息为索引，找到组播会话的上下文，将组播会话的上下文中包括的终端的标识信息所标识的终端确定为加入组播会话且由该接入网设备提供网络服务的终端。
S803：接入与移动性管理功能网元向第一会话管理功能网元发送第十消息。相应的，第一会话管理功能网元接收来自接入与移动性管理功能网元的第十消息。
其中，S803中的接入与移动性管理功能网元可以是第一终端对应的接入与移动性管理功能网元，第一会话管理功能网元可以是第一终端对应的会话管理功能网元，第一会话管理功能网元可以用于管理的第一终端的与组播会话关联的PDU会话。第一会话管理功能网元中存储有组播会话的上下文、以及组播会话关联的PDU会话的上下文等。
其中，第十消息可以用于指示组播会话激活或者激活组播会话，第十消息可以包括组播会话的标识信息。第十消息可以是N11消息，N11消息可以是PDU会话上下文更新请求/回复(Nsmf_PDUSession_UpdateSMContext Request/Response)。可选的，第十消息还可以包含组播会话激活的通知。
示例性的，以接入与移动性管理功能网元对应第一终端为例，接入与移动性管理功能网元接收到第六消息后，可以根据第六消息与第一终端的对应关系获知该第六消息是第一终端的消息，根据第一终端的标识信息确定第一终端的PDU会话与该组播会话关联的PDU会话，通过接入与移动性管理功能网元与第一会话管理功能网元之间与该PDU会话对应的控制面信令消息发送第十消息。
S804：第一会话管理功能网元根据第十消息，将组播会话的状态设置为激活态。
示例性的，第一会话管理功能网元可以根据第十消息携带的组播会话的标识信息，找到第一会话管理功能网元保存的组播会话的上下文，将组播会话的上下文中组播会话的状态从去激活态更改为激活态。
进一步的，图8所示方法还可以包括：如果存在组播关联的PDU会话，且PDU会话的状态为去激活态，则第一会话管理功能网元激活PDU会话。如果存在组播关联的PDU会话，且去激活PDU会话的状态，由于第一会话管理功能网元已经收到了组播会话激活的通知，那么第一会话管理功能网元不去激活关联的PDU会话。
具体的，第一会话管理功能网元激活PDU会话可以包括：第一会话管理功能网元向接入与移动性管理功能网元发送N1N2消息传输(Namf_Communication_N1N2Message Transfer)。N1N2消息传输包含N2 SM信息(N2 SM Information)，N2 SM消息包含所述组播会话的标识信息，N2 SM消息可以是PDU会话资源建立请求传输(PDU session resource setup request transfer)或PDU会话资源修改请求传输(PDU session resource modify request transfer)。接入与移动性管理功能网元接收N1N2消息传输，向接入网设备发送N2消息，包含所述N2 SM Information。所述N2消息可以是PDU会话资源建立请求(PDU session resource setup request)或PDU会话资源修改请求(PDU session resource modify request)。接入网设备收到N2消息后，为所述PDU会话准备/配置无线承载(比如DRB)。接入网设备向接入与移动性管理功能网元回复N2消息，N2消息可以是PDU会话资源建立回复(PDU session  resource setup response)或PDU会话资源修改回复(PDU session resource modify response)，N2消息包含给第一会话管理功能网元的N2 SM消息的回复，也即PDU会话资源建立回复传输(PDU session resource setup response transfer)或PDU会话资源修改请求传输(PDU session resource modify response transfer),N2 SM information中携带接入网设备分配的隧道信息(比如接入网设备的接入网隧道信息(AN tunnel Info)，该隧道信息可以用于第一会话管理功能网元通知给PDU会话的锚点(PDU session anchor，PSA)，以便建立PSA与接入网设备之间的下行隧道。至此，组播会话关联的PDU会话被激活。
基于图8所示方法，可以在接入网设备激活组播会话之后，由接入网设备通过接入与移动性管理功能网元通知第一会话管理功能网元也激活组播会话，以保证网元之间维护的组播会话状态统一。同时，无需核心网网元以终端为粒度通知该终端对应的接入网设备将终端加入组播会话，降低信令开销。
进一步的，如图8所示方法中，如果组播会话关联的PDU会话处于去激活态，则接入网设备激活组播会话之后，还可以根据该PDU会话的上下文中与所述组播会话对应的组播QoS信息对应的单播QoS信息，为该PDU会话对应的终端配置单播无线承载；其中单播无线承载可以用于通过PDU会话向终端传输组播业务的数据。
其中，组播会话对应的组播QoS信息、单播QoS信息的相关描述可参照上文图7对应的实施例中所述，不予赘述。需要说明的是，在组播会话关联的PDU会话去激活时，该该PDU会话的上下文中与所述组播会话对应的组播QoS信息对应的单播QoS信息未释放/未从接入网设备删除，仍保留在接入网设备上，以便组播会话激活时，接入网设备可以根据该组播会话关联的PDU会话的上下文中、与所述组播会话对应的组播QoS信息对应的单播QoS信息为该终端建立单播无线承载，激活组播会话关联的PDU会话。具体的，可以参照下述图9所示方法，在去激活组播会话关联的PDU会话时，将组播会话关联的PDU会话对应的单播QoS信息保留在接入网设备上。
图9为本申请实施例提供的一种通信方法，如图9所示，所述方法可以包括：
S901：第一会话管理功能网元确定去激活PDU会话。
其中，第一会话管理功能网元可以是管理PDU会话的SMF。
示例性的，该PDU会话对应的PSA一段时间内没有检测到数据达到时，PDU会话对应的PSA可以向第一会话管理功能网元发送未检测到数据传输的通知，第一会话管理功能网元接收到PSA的通知，根据PSA的通知确定去激活PDU会话。
S902：第一会话管理功能网元向接入网设备发送第九消息。相应的，接入网设备接收来自第一会话管理功能网元的第九消息。
其中，第九消息可以包含PDU会话的标识信息。第九消息可以用于指示去激活该PDU会话，还可以用于接入网设备保留该PDU会话的与组播会话对应的组播QoS信息对应的单播QoS信息。可选的，如果该PDU会话与组播会话关联，第九消息还可以包括以及组播会话的标识信息和/或第四指示信息，第四指示信息可以指示保留与组播会话对应的组播QoS信息对应的单播QoS信息。
其中，PDU会话与组播会话关联可以包括下述一种或者多种：组播会话的标识信息存储在PDU会话的上下文中(比如PDU会话的会话管理上下文(session management context，SM context)中，或者，组播会话的上下文(例如MBS session context)中存储了该PDU会话的 标识信息(比如该PDU会话的SM context ID等)或存储了该PDU会话对应的终端的标识信息等。
示例性的，第一会话管理功能网元向接入网设备发送第九消息可以包括：第一会话管理功能网元将第九消息携带在与该PDU会话对应的N1N2消息传输(Namf_Communication_N1N2Message Transfer)中发送给接入与移动性管理功能网元，接入与移动性管理功能网元接收到N1N2消息传输，从中获取第九消息，将第九消息携带在N2消息中发送给该PDU会话对应的接入网设备，所述N2消息可以是PDU会话资源释放命令/请求传输(PDU session resource release command/request transfer)。
S903：接入网设备根据第九消息，保留PDU会话的上下文中与组播会话对应的组播QoS信息对应的单播QoS信息。
一种示例中，第九消息包括PDU会话的标识信息、组播会话的标识信息和/或第四指示信息，接入网设备可以根据第九消息携带的PDU会话的标识信息确定去激活PDU会话，根据第九消息携带的组播会话的标识信息和/或第四指示信息保留/不释放组播会话对应的组播QoS信息对应的的单播QoS信息。可选的，接入网设备还可以保留/不释放PDU会话的标识信息(例如PDU会话的ID)。
又一种示例中，第九消息包括PDU会话的标识信息，接入网设备可以根据第九消息携带的PDU会话的标识信息确定去激活PDU会话，此时，接入网设备确定该PDU会话是否与组播会话关联，如果该PDU会话与组播会话关联，则接入网设备保留/不释放组播会话对应的组播QoS信息对应的的单播QoS信息。可选的，接入网设备还可以保留/不释放PDU会话的标识信息(例如PDU会话的ID)。
本申请实施例中，对于支持组播功能的接入网设备，该接入网设备中存储有组播会话的上下文(比如MBS session context)。可选的，该接入网设备还存储有加入组播会话的终端的上下文(比如NGAP UE context)(注：NGAP UE conext与接入与移动性管理功能网元中的UE context不同)。在接入网设备的NGAP UE Context中有终端的所有PDU会话的上下文，其中对于用于加入组播会话的PDU会话，该PDU会话的上下文中保存了组播会话的标识信息。接入网设备可以通过查看PDU会话的上下文中是否包括组播会话的标识来确定该PDU会话是否与组播会话关联。
基于图9所示方法，可以在去激活与组播会话关联的PDU会话时，不释放接入网设备上与组播QoS信息对应的单播QoS信息，以便组播会话激活时，接入网设备可以根据该组播会话关联的PDU会话对应的单播QoS信息建立单播无线承载，激活组播会话关联的PDU会话，保证组播业务的数据的正常传输。
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，例如接入与移动性管理功能网元、第一会话管理功能网元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来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本申请的范围。
本申请实施例可以根据上述方法示例对接入与移动性管理功能网元、第一会话管理功 能网元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10示出了一种通信装置100的结构图，该通信装置100可以为第一会话管理功能网元、第一会话管理功能网元中的芯片、片上系统或者其他能够实现上述方法中第一会话管理功能网元的功能的装置等。该通信装置100可以用于执行上述方法实施例中涉及的第一会话管理功能网元的功能。作为一种可实现方式，图10所示通信装置100包括：接收单元1002以及发送单元1003。进一步的，还可以包括处理单元1001。
一种可能的设计中，接收单元1002，用于接收来自第二会话管理功能网元的第一消息，第二会话管理功能网元对应于组播会话，第一消息用于通知组播会话激活或者用于通知组播会话释放。例如，接收单元1002可以支持通信装置100执行S502。
发送单元1003，用于根据第一消息，向接入与移动性管理功能网元发送第一信息，第一信息包括组播会话的标识信息和/或指示信息，指示信息用于指示组寻呼。例如，发送单元1003用于支持通信装置100执行S504。
又一种可能的设计中，发送单元1003，用于向接入与移动性管理功能网元发送第二消息；其中，第二消息用于接入与移动性管理功能网元将处于CM-CONNECTED态的终端指示给第一会话管理功能网元。例如，发送单元1003可以支持通信装置100执行S601以及S703。
接收单元1002，用于接收来自接入与移动性管理功能网元的第三消息；其中，第三消息包括第一终端的标识信息和/或组播会话的标识信息；第一会话管理功能网元用于管理第一终端的协议数据单元PDU会话中与组播会话关联的PDU会话，处于CM-CONNECTED态的终端包括第一终端。例如，接收单元1002可以支持通信装置100执行S602、S706。
再一种可能的设计中，接收单元1002，用于接收来自接入与移动性管理功能网元的第十消息；第十消息用于指示组播会话激活，第十消息包括组播会话的标识信息。例如，接收单元1002用于支持通信装置100执行S803。
处理单元1001，用于根据第十消息，将组播会话的状态设置为激活态。例如，处理单元1001用于支持通信装置100执行S804。
具体的，上述图5-图9所示方法实施例涉及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。通信装置100用于执行图5至图9所示方法所示通信方法中第一会话管理功能网元的功能，因此可以达到与上述通信方法相同的效果。
作为又一种可实现方式，图10所示通信装置100包括：处理模块和通信模块。处理模块用于对通信装置100的动作进行控制管理，例如，处理模块可以集成处理单元1001的功能，执行S804以及其他控制功能。通信模块可以集成发送单元1003和接收单元1002的功能，执行S502、S504、S803、S804以及与其他网络实体的通信，例如与图2或图3a或图3b示出的功能模块或网络实体之间的通信。进一步的，该通信装置100还可以包括存储模块，用于存储指令和/或数据。该指令被处理模块执行时，使得处理模块实现上述第一会话管理功能网元侧的方法。
其中，处理模块可以是处理器、控制器、模块或电路。其可以实现或执行结合本申请 实施例公开内容所描述的各种示例性的逻辑方框。通信模块可以是收发电路、管脚、接口电路、总线接口、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，本申请实施例涉及的通信装置100可以为图4所示通信装置400。
图11示出了一种通信装置110的结构图，该通信装置110可以为接入与移动性管理功能网元、接入与移动性管理功能网元中的芯片、片上系统或者其他能够实现上述方法中接入与移动性管理功能网元的功能的装置等。该通信装置110可以用于执行上述方法实施例中涉及的接入与移动性管理功能网元的功能。作为一种可实现方式，图11所示通信装置110包括：处理单元1101、接收单元1102、发送单元1103。
一种可能的设计中，接收单元1102，用于接收来自第一会话管理功能网元的第一信息，第一信息包括组播会话的标识信息和/或指示信息，指示信息用于指示组寻呼。例如，接收单元1102用于支持通信装置110执行S504。
处理单元1101，用于根据第一信息组寻呼。例如，处理单元1101用于支持通信装置110执行S505。
又一种可能的设计中，接收单元1102，用于接收来自第一会话管理功能网元的第二消息；其中，第二消息用于接入与移动性管理功能网元将处于CM-CONNECTED态的终端指示给第一会话管理功能网元。例如，接收单元1102可以支持通信装置110执行S601以及S703。
发送单元1103，用于根据第二消息，向第一会话管理功能网元发送第三消息；其中，第三消息包括第一终端的标识信息和/或组播会话的标识信息；第一会话管理功能网元用于管理第一终端的协议数据单元PDU会话中与组播会话关联的PDU会话，处于CM-CONNECTED态的终端包括第一终端。例如，发送单元1103可以支持通信装置110执行S602、S706以及S707。
再一种可能的设计中，接收单元1102，用于接收来自接入网设备的第六消息；其中，第六消息用于指示组播会话激活，第六消息包括组播会话的标识信息。例如，接收单元1102用于支持通信装置110执行S802。
发送单元1103，用于根据第六消息，向第一会话管理功能网元发送第十消息；其中，第十消息用于指示组播会话激活，第十消息包括组播会话的标识信息。例如，发送单元1103用于支持通信装置110执行S803。
具体的，上述图5-图9所示方法实施例涉及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。通信装置110用于执行图5至图9所示方法所示通信方法中接入与移动性管理功能网元的功能，因此可以达到与上述通信方法相同的效果。
作为又一种可实现方式，图11所示通信装置110包括：处理模块和通信模块。处理模块用于对通信装置110的动作进行控制管理，例如，处理模块可以集成处理单元1101的功能，可以用于支持通信装置110执行S505以及其他步骤。通信模块可以集成发送单元1103和接收单元1102的功能，如执行S504、S601、S703、S602、S706、S707、S802、S803等以及与其他网络实体的通信，例如与图2或图3a或图3b示出的功能模块或网络实体之间的通信。进一步的，该通信装置110还可以包括存储模块，用于存储指令和/或数据。该指令被处理模块执行时，使得处理模块实现上述接入与移动性管理功能网元侧的方法。
其中，处理模块可以是处理器、控制器、模块或电路。其可以实现或执行结合本申请实施例公开内容所描述的各种示例性的逻辑方框。通信模块可以是收发电路、管脚、接口电路、总线接口、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，本申请实施例涉及的通信装置110可以为图4所示通信装置400。
图12示出了一种通信装置120的结构图，该通信装置120可以为接入网设备、接入网设备中的芯片、片上系统或者其他能够实现上述方法中接入网设备的功能的装置等。该通信装置120可以用于执行上述方法实施例中涉及的接入网设备的功能。作为一种可实现方式，图12所示通信装置120包括：处理单元1201以及发送单元1202。
处理单元1201，用于确定组播业务对应的组播会话激活。例如，处理单元1201可以支持通信装置120执行S801。
发送单元1202，用于向第一终端对应的接入网设备发送第六消息；其中，所述第六消息用于指示所述组播会话激活，所述第六消息包括所述组播会话的标识信息，所述第一终端是加入所述组播会话的终端。例如，发送单元1202可以支持通信装置120执行S802。
具体的，上述图5-图9所示方法实施例涉及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。通信装置120用于执行图5至图9所示方法所示通信方法中接入网设备的功能，因此可以达到与上述通信方法相同的效果。
作为又一种可实现方式，图12所示通信装置120包括：处理模块和通信模块。处理模块用于对通信装置120的动作进行控制管理，例如，处理模块可以集成处理单元1201的功能，可以用于支持通信装置120执行S801等步骤。通信模块可以集成发送单元1202的功能，如执行S802等以及与其他网络实体的通信，例如与图2或图3a或图3b示出的功能模块或网络实体之间的通信。进一步的，该通信装置120还可以包括存储模块，用于存储指令和/或数据。该指令被处理模块执行时，使得处理模块实现上述接入网设备侧的方法。
其中，处理模块可以是处理器、控制器、模块或电路。其可以实现或执行结合本申请实施例公开内容所描述的各种示例性的逻辑方框。通信模块可以是收发电路、管脚、接口电路、总线接口、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，本申请实施例涉及的通信装置120可以为图4所示通信装置400。
在本申请实施例中，处理器可以是通用处理器、数字信号处理器、专用集成电路、现场可编程门阵列或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件，可以实现或者执行本申请实施例中的公开的各方法、步骤及逻辑框图。通用处理器可以是微处理器或者任何常规的处理器等。结合本申请实施例所公开的方法的步骤可以直接体现为硬件处理器执行完成，或者用处理器中的硬件及软件模块组合执行完成。
在本申请实施例中，存储器可以是非易失性存储器，比如硬盘(hard disk drive，HDD)或固态硬盘(solid-state drive，SSD)等，还可以是易失性存储器(volatile memory)，例如随机存取存储器(random-access memory，RAM)。存储器是能够用于携带或存储具有指令或数据结构形式的期望的程序代码并能够由计算机存取的任何其他介质，但不限于此。本申请实施例中的存储器还可以是电路或者其它任意能够实现存储功能的装置，用于存储指令和/或数据。
图13为本申请实施例提供的一种通信系统的结构图，如图13所示，该通信系统可以包括：接入与移动性管理功能网元130以及第一会话管理功能网元131。需要说明的是，图13仅为示例性附图，本申请实施例不限定图13所示通信系统包括的网元以及网元的个数，比如，图13还可以包括接入网设备、终端、第二会话管理功能网元、UPF以及MB-UPF等。
其中，接入与移动性管理功能网元130具有上述图5至图9所示的一个或多个方法中接入与移动性管理功能网元的功能。第一会话管理功能网元131具有上述图5至图9所示的一个或多个方法中第一会话管理功能网元的功能。
在本申请实施例中，“/”可以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；“和/或”可以用于描述关联对象存在三种关系，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。为了便于描述本申请实施例的技术方案，在本申请实施例中，可以采用“第一”、“第二”等字样对功能相同或相似的技术特征进行区分。该“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。在本申请实施例中，“示例性的”或者“例如”等词用于表示例子、例证或说明，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。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。
在本申请实施例中，对于一种技术特征，通过“第一”、“第二”、“第三”、“A”、“B”、“C”和“D”等区分该种技术特征中的技术特征，该“第一”、“第二”、“第三”、“A”、“B”、“C”和“D”描述的技术特征间无先后顺序或者大小顺序。
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。
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，另外，在本申请各个实施例中的各功能模块可以集成在一个处理器中，也可以是单独物理存在，也可以两个或两个以上模块集成在一个模块中。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。
本申请实施例提供的技术方案可以全部或部分地通过软件、硬件、固件或者其任意组合来实现。当使用软件实现时，可以全部或部分地以计算机程序产品的形式实现。所述计算机程序产品包括一个或多个计算机指令。在计算机上加载和执行所述计算机程序指令时，全部或部分地产生按照本申请实施例所述的流程或功能。所述计算机可以是通用计算机、专用计算机、计算机网络、无线控制装置、接入网设备、终端或者其他可编程装置。所述计算机指令可以存储在计算机可读存储介质中，或者从一个计算机可读存储介质向另一个 计算机可读存储介质传输，例如，所述计算机指令可以从一个网站站点、计算机、服务器或数据中心通过有线(例如同轴电缆、光纤、数字用户线(digital subscriber line，DSL))或无线(例如红外、无线、微波等)方式向另一个网站站点、计算机、服务器或数据中心进行传输。所述计算机可读存储介质可以是计算机可以存取的任何可用介质或者是包含一个或多个可用介质集成的服务器、数据中心等数据存储设备。所述可用介质可以是磁性介质(例如，软盘、硬盘、磁带)、光介质(例如，数字视频光盘(digital video disc，DVD))、或者半导体介质等。
在本申请实施例中，在无逻辑矛盾的前提下，各实施例之间可以相互引用，例如方法实施例之间的方法和/或术语可以相互引用，例如装置实施例之间的功能和/或术语可以相互引用，例如装置实施例和方法实施例之间的功能和/或术语可以相互引用。
以上所述，仅为本申请实施例的具体实施方式，但本申请实施例的保护范围并不局限于此，任何在本申请实施例揭露的技术范围内的变化或替换，都应涵盖在本申请实施例的保护范围之内。因此，本申请实施例的保护范围应以所述权利要求的保护范围为准。

Claims (45)

  1. 一种通信方法，其特征在于，所述方法包括：
    第一会话管理功能网元接收来自第二会话管理功能网元的第一消息，所述第二会话管理功能网元对应于组播会话，所述第一消息用于通知所述组播会话激活或者用于通知所述组播会话释放；
    所述第一会话管理功能网元根据所述第一消息，向接入与移动性管理功能网元发送第一信息，所述第一信息包括所述组播会话的标识信息和/或指示信息，所述指示信息用于指示组寻呼。
  2. 根据权利要求1所述的方法，其特征在于，所述方法还包括：
    所述第一会话管理功能网元根据所述第一消息，确定在所述组播会话关联的协议数据单元PDU会话中处于去激活状态的PDU会话的数量满足预设条件。
  3. 根据权利要求1或2所述的方法，其特征在于，
    所述指示信息包括第一指示信息或第二指示信息；
    其中，所述第一指示信息用于指示采用组寻呼方式寻呼所述组播会话对应的终端，或所述第二指示信息用于指示采用组寻呼方式寻呼所述去激活状态的PDU会话对应的终端。
  4. 根据权利要求1-3任一项所述的方法，其特征在于，
    所述第一信息携带在N1N2消息传输中；或者，
    所述第一信息携带在N11消息中。
  5. 一种通信方法，其特征在于，所述方法包括：
    接入与移动性管理功能网元接收来自第一会话管理功能网元的第一信息，所述第一信息包括组播会话的标识信息和/或指示信息，所述指示信息用于指示组寻呼；
    所述接入与移动性管理功能网元根据所述第一信息组寻呼。
  6. 根据权利要求5所述的方法，其特征在于，
    所述指示信息包括第一指示信息或第二指示信息；
    其中，所述第一指示信息用于指示采用组寻呼方式寻呼所述组播会话对应的终端，或所述第二指示信息用于指示采用组寻呼方式寻呼所述去激活状态的PDU会话对应的终端。
  7. 根据权利要求5或6所述的方法，其特征在于，
    所述第一信息携带在N1N2消息传输中；或者，
    所述第一信息携带在N11消息中。
  8. 根据权利要求5-7任一项所述的方法，其特征在于，所述接入与移动性管理功能网元根据所述第一信息组寻呼，包括：
    所述接入与移动性管理功能网元根据所述第一信息确定处于CM-IDLE态的终端；
    所述接入与移动性管理功能网元根据所述指示信息，在处于CM-IDLE态的终端的寻呼区域发送寻呼消息，所述寻呼消息包括所述组播会话的标识信息；所述处于CM-IDLE态的终端的寻呼区域包括所述处于CM-IDLE态的终端的注册区域的并集。
  9. 一种通信方法，其特征在于，所述方法包括：
    接入与移动性管理功能网元接收来自第一会话管理功能网元的第二消息；其中，所述第二消息用于所述接入与移动性管理功能网元将处于连接管理-连接CM-CONNECTED态的终端指示给所述第一会话管理功能网元；
    所述接入与移动性管理功能网元根据所述第二消息，向所述第一会话管理功能网元发送第三消息；其中，所述第三消息包括第一终端的标识信息和/或所述组播会话的标识信息；所述第一会话管理功能网元用于管理所述第一终端的协议数据单元PDU会话中与所述组播会话关联的PDU会话，所述CM-CONNECTED态的终端包括所述第一终端。
  10. 根据权利要求9所述的方法，其特征在于，
    所述第二消息包括所述组播会话的标识信息。
  11. 根据权利要求9或者10所述的方法，其特征在于，
    所述第二消息还用于寻呼处于连接管理-空闲CM-IDLE态的终端。
  12. 根据权利要求9-11任一项所述的方法，其特征在于，所述接入与移动性管理功能网元根据所述第二消息，向所述第一会话管理功能网元发送第三消息，包括：
    所述接入与移动性管理功能网元接收到所述第二消息；
    若存在处于CM-IDLE态的终端，则所述接入与移动性管理功能网元根据所述第二消息，寻呼所述处于CM-IDLE态的终端；所述处于CM-IDLE态的终端包括所述第一终端；
    所述接入与移动性管理功能网元接收到来自所述第一终端的服务请求；
    所述接入与移动性管理功能网元向所述第一会话管理功能网元发送所述第三消息。
  13. 根据权利要求12所述的方法，其特征在于，所述接入与移动性管理功能网元根据所述第二消息寻呼所述处于CM-IDLE态的终端，包括：
    所述接入与移动性管理功能网元根据所述第二消息、以及所述处于CM-IDLE态的终端的注册区域中接入网设备的组播能力信息，寻呼所述处于CM-IDLE态的终端。
  14. 根据权利要求13所述的方法，其特征在于，所述接入与移动性管理功能网元根据所述第二消息、以及所述处于CM-IDLE态的终端的注册区域中接入网设备的组播能力信息，寻呼所述处于CM-IDLE态的终端，包括：
    若所述第一终端的注册区域中第一接入网设备支持组播功能，则所述接入与移动性管理功能网元向所述第一接入网设备发送寻呼消息，所述寻呼消息包括所述组播会话的标识信息；或，若所述第一终端的注册区域中第二接入网设备不支持组播功能，则所述接入与移动性管理功能网元向所述第二接入网设备发送寻呼消息，所述寻呼消息包括所述第一终端的标识信息；所述处于CM-IDLE态的终端包括所述第一终端。
  15. 根据权利要求14所述的方法，其特征在于，
    所述第一接入网设备还位于第二终端的注册区域，所述处于CM-IDLE态的终端还包括所述第二终端。
  16. 根据权利要求11所述的方法，其特征在于，所述方法还包括：
    所述接入与移动性管理功能网元根据所述第二消息，确定处于CM-IDLE态的终端；
    所述接入与移动性管理功能网元在所述处于CM-IDLE态的终端的寻呼区域发送寻呼消息，所述寻呼消息包括所述组播会话的标识信息；所述处于CM-IDLE态的终端的寻呼区域包括支持组播能力的接入网设备；所述处于CM-IDLE态的终端包括所述第一终端。
  17. 根据权利要求12所述的方法，其特征在于，所述接入与移动性管理功能网元根据所述第二消息寻呼所述处于CM-IDLE态的终端，包括：
    所述接入与移动性管理功能网元根据所述第二消息，向所述第一终端对应的接入网设备发送第四消息，所述第四消息包括所述第一终端的标识信息和所述组播会话的标识信息； 所述处于CM-IDLE态的终端包括所述第一终端。
  18. 根据权利要求9-11任一项所述的方法，其特征在于，所述方法还包括：
    所述接入与移动性管理功能网元接收到所述第二消息；
    若存在处于CM-CONNECTED的终端，则所述接入与移动性管理功能网元根据所述第二消息，向所述第一会话管理功能网元发送所述第三消息；所述处于CM-CONNECTED态的终端包括所述第一终端。
  19. 一种通信方法，其特征在于，所述方法包括：
    第一会话管理功能网元向接入与移动性管理功能网元发送第二消息；其中，所述第二消息用于所述接入与移动性管理功能网元将处于连接管理-连接CM-CONNECTED态的终端指示给所述第一会话管理网元；
    所述第一会话管理功能网元接收来自所述接入与移动性管理功能网元的第三消息；其中，所述第三消息包括第一终端的标识信息和/或组播会话的标识信息；所述第一会话管理功能网元用于管理所述第一终端的协议数据单元PDU会话中与所述组播会话关联的PDU会话，所述处于CM-CONNECTED态的终端包括所述第一终端。
  20. 根据权利要求19所述的方法，其特征在于，所述方法还包括：
    所述第一会话管理功能网元接收来自第二会话管理功能网元的第一消息，所述第二会话管理功能网元对应于所述组播会话，所述第一消息用于通知所述组播会话激活或者用于通知所述组播会话释放；
    所述第一会话管理功能网元向所述接入与移动性管理功能网元发送所述第二消息包括：所述第一会话管理功能网元根据所述第一消息，向所述接入与移动性管理功能网元发送所述第二消息。
  21. 根据权利要求19或20所述的方法，其特征在于，
    所述第二消息包括所述组播会话的标识信息。
  22. 根据权利要求19-21任一项所述的方法，其特征在于，
    所述第二消息还用于寻呼处于连接管理-空闲CM-IDLE态的终端。
  23. 根据权利要求19-22任一项所述的方法，其特征在于，所述方法还包括：
    所述第一会话管理功能网元根据所述第三消息，向所述第一终端对应的接入网设备发送第二信息；其中，所述第二信息用于所述接入网设备配置用于向所述第一终端传输组播业务的数据的无线承载，或者所述第二信息用于所述接入网设备释放用于向所述第一终端传输组播业务的数据的资源。
  24. 根据权利要求23所述的方法，其特征在于，所述第二信息用于所述接入网设备配置用于向所述第一终端传输组播业务的数据的无线承载；
    所述第二信息包括以下至少一种：所述组播会话的标识信息，所述组播会话对应的组播服务质量QoS信息，所述组播QoS信息对应的单播QoS信息，或者所述组播会话的组播服务质量流QoS Flow对应的单播服务质量流标识QoS Flow ID。
  25. 根据权利要求23所述的方法，其特征在于，所述第二信息用于所述接入网设备释放用于向所述第一终端传输组播业务的数据的资源，所述资源包含用于向所述第一终端传输所述组播业务的数据的无线承载，所述组播业务对应的组播QoS信息，或者所述组播QoS信息对应的单播QoS信息中的一种或者多种；所述第二信息包括以下至少一种：
    所述组播会话的标识信息，所述组播会话的组播QoS Flow对应的单播QoS Flow ID，所述组播会话对应的组播服务质量QoS信息，所述组播QoS信息对应的单播QoS信息，或者释放指示；所述释放指示用于指示释放用于向所述第一终端传输所述组播业务的数据的资源。
  26. 一种通信方法，其特征在于，所述方法包括：
    接入网设备确定组播业务对应的组播会话激活；
    所述接入网设备向第一终端对应的接入与移动性管理功能网元发送第六消息；其中，所述第六消息用于指示所述组播会话激活，所述第六消息包括所述组播会话的标识信息，所述第一终端是加入所述组播会话的终端。
  27. 根据权利要求26所述的方法，其特征在于，所述加入所述组播会话的终端还包括第二终端，所述方法还包括：
    所述接入网设备向所述第二终端对应的接入与移动性管理功能网元发送第七消息；所述第七消息用于指示所述组播会话激活，所述第七消息包括所述组播会话的标识信息。
  28. 根据权利要求26或27所述的方法，其特征在于，所述方法还包括：
    当所述接入网设备接收到来自组播广播-用户面功能MB-UPF的所述组播业务的数据时，所述接入网设备确定所述组播业务对应的组播会话激活。
  29. 根据权利要求26或27所述的方法，其特征在于，所述方法还包括：
    所述接入网设备接收来自所述接入与移动性管理功能网元的第八消息；其中，所述第八消息用于指示激活所述组播会话，所述第八消息包括所述组播会话的标识信息；
    所述接入网设备根据所述第八消息确定所述组播业务对应的组播会话激活。
  30. 根据权利要求26-29任一项所述的方法，其特征在于，所述方法还包括：
    所述接入网设备根据单播服务质量QoS信息配置单播无线承载；其中，所述单播QoS信息与所述组播会话的QoS信息对应，所述单播无线承载用于通过协议数据单元PDU会话传输所述组播业务的数据。
  31. 根据权利要求30所述的方法，其特征在于，所述方法还包括：
    所述接入网设备接收来自第一会话管理功能网元的第九消息；其中，所述第九消息包含PDU会话的标识信息；所述第九消息用于指示去激活所述PDU会话；
    所述接入网设备根据所述第九消息，保留所述PDU会话的上下文中与所述组播会话的组播服务质量QoS信息对应的单播QoS信息。
  32. 根据权利要求31所述的方法，其特征在于，所述第九消息还包括所述组播会话的标识信息和/或第四指示信息，所述第四指示信息指示保留与所述组播会话的组播服务质量QoS信息对应的单播QoS信息；所述接入网设备根据所述第九消息，保留所述PDU会话的上下文中与所述组播会话的组播服务质量QoS信息对应的单播QoS信息，包括：
    所述接入网设备根据所述第四指示信息，保留所述PDU会话的上下文中与所述组播会话的组播服务质量QoS信息对应的单播QoS信息。
  33. 根据权利要求31所述的方法，其特征在于，所述接入网设备根据所述第九消息，保留所述PDU会话的上下文中与所述组播会话的多播服务质量QoS信息对应的单播QoS信息，包括：
    若所述接入网设备确定所述PDU会话与所述组播会话关联，则所述接入网设备保留所 述PDU会话的上下文中与所述组播会话的多播服务质量QoS信息对应的单播QoS信息。
  34. 一种通信方法，其特征在于，所述方法包括：
    接入与移动性管理功能网元接收来自接入网设备的第六消息；其中，所述第六消息用于指示组播会话激活，所述第六消息包括所述组播会话的标识信息；
    所述接入与移动性管理功能网元根据所述第六消息，向第一会话管理功能网元发送第十消息；其中，所述第十消息用于指示所述组播会话激活，所述第十消息包括所述组播会话的标识信息。
  35. 根据权利要求34所述的方法，其特征在于，所述方法还包括：
    所述接入与移动性管理功能网元接收来自第二会话管理功能网元的所述组播会话激活的通知；所述第二会话管理功能网元对应于所述组播会话；
    所述接入与移动性管理功能网元根据所述组播会话激活的通知，向所述接入网设备发送第八消息；其中，所述第八消息用于指示激活所述组播会话，所述第八消息包括所述组播会话的标识信息。
  36. 一种通信方法，其特征在于，所述方法包括：
    第一会话管理功能网元接收来自接入与移动性管理功能网元的第十消息；其中，所述第十消息用于指示所述组播会话激活，所述第十消息包括所述组播会话的标识信息；
    所述第一会话管理功能网元根据所述第十消息，将所述组播会话的状态设置为激活态。
  37. 根据权利要求36所述的方法，其特征在于，所述方法还包括：
    若存在所述组播关联的PDU会话，且所述PDU会话的状态为去激活态，则所述第一会话管理功能网元激活所述PDU会话。
  38. 根据权利要求37所述的方法，其特征在于，所述方法还包括：
    所述第一会话管理功能网元确定去激活所述PDU会话；
    所述第一会话管理功能网元向接入网设备发送第九消息；其中，所述第九消息包含PDU会话的标识信息；所述第九消息用于指示去激活所述PDU会话。
  39. 根据权利要求38所述的方法，其特征在于，所述第九消息还包括第四指示信息和/或所述组播会话的标识信息，所述第四指示信息指示保留所述PDU会话的上下文中与所述组播会话的组播服务质量QoS信息对应的单播QoS信息。
  40. 一种通信装置，其特征在于，所述通信装置用于执行如权利要求1-4任一项所述的方法或者权利要求19-25任一项所述的方法或者权利要求36-39任一项所述的方法。
  41. 一种通信装置，其特征在于，所述通信装置用于执行如权利要求5-8任一项所述的方法或者权利要求9-18任一项所述的方法或者权利要求34-35任一项所述的方法。
  42. 一种通信装置，其特征在于，所述通信装置用于执行如权利要求26-33任一项所述的方法。
  43. 一种通信系统，其特征在于，所述通信系统包括如权利要求40所述的通信装置、如权利要求41所述的通信装置以及如权利要求42所述的通信装置。
  44. 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存储计算机指令，当所述计算机指令在计算机上运行时，使得计算机执行如权利要求1-4任一项所述的方法或者权利要求19-25任一项所述的方法或者权利要求36-39任一项所述的方法；或者如权利要求5-8任一项所述的方法或者权利要求9-18任一项所述的方法或者权利要求34-35任一项 所述的方法；或者执行如权利要求26-33任一项所述的方法。
  45. 一种计算机程序产品，其特征在于，所述计算机程序产品包括计算机指令，当所述计算机指令在计算机上运行时，使得计算机执行如权利要求1-4任一项所述的方法或者权利要求19-25任一项所述的方法或者权利要求36-39任一项所述的方法；或者如权利要求5-8任一项所述的方法或者权利要求9-18任一项所述的方法或者权利要求34-35任一项所述的方法；或者执行如权利要求26-33任一项所述的方法。
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