WO2024007895A1 - 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
WO2024007895A1
WO2024007895A1 PCT/CN2023/102761 CN2023102761W WO2024007895A1 WO 2024007895 A1 WO2024007895 A1 WO 2024007895A1 CN 2023102761 W CN2023102761 W CN 2023102761W WO 2024007895 A1 WO2024007895 A1 WO 2024007895A1
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Prior art keywords
mbs
session
qfi
network device
initial
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PCT/CN2023/102761
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English (en)
French (fr)
Inventor
张海森
李秉肇
许斌
曹振臻
王燕
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华为技术有限公司
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Publication of WO2024007895A1 publication Critical patent/WO2024007895A1/zh

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W24/00—Supervisory, monitoring or testing arrangements
    • H04W24/02—Arrangements for optimising operational condition
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
    • H04W4/06—Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services

Definitions

  • the embodiments of the present application relate to the field of communication, and in particular, to a communication method and device.
  • the protocol data unit (PDU) data (DATA) identifier (also called the COUNT value) of the packet data convergence protocol (PDCP) layer is determined by the high-order superframe number (hyper frame number, HFN) and the low-order PDCP sequence number (sequence number, SN).
  • the PDCP PDU sent by the sender to the receiver includes the PDCP SN, and the HFN is calculated by the receiver.
  • the access network device needs to indicate the initial COUNT value corresponding to the MRB to the terminal device so that the terminal The device determines the status variable of the PDCP window or the COUNT value of subsequent received data packets based on the initial COUNT value.
  • the access network device configures MRB, it may not have received the data packet from the core network device. At this time, how the access network equipment indicates the initial COUNT value is an issue that needs to be solved urgently.
  • This application provides a communication method and device so that the access network equipment can promptly configure the initial HFN and reference SN for the terminal equipment without receiving a data packet from the core network equipment.
  • the core network device can send the initial MBS QFI SN corresponding to the first MBS session before the multicast broadcast user plane network element sends the first data packet of the first MBS session to the access network device, so that the access network
  • the device can determine the initial HFN and reference SN based on the initial MBS QFI SN, thereby configuring the initial HFN and reference SN to the terminal device, so that the access network device can promptly configure the MRB for the terminal device without waiting for the arrival of the data packet, indicating the initial HFN and reference SN.
  • the core network side may eventually use the initial MBS QFI SN as the MBS QFI SN of the first data packet, or determine the first data packet based on the initial MBS QFI SN. MBS QFI SN of a data packet, thereby improving the accuracy of the initial HFN and reference SN configured by the access network device before receiving the data packet.
  • the initial MBS QFI SN corresponding to the first MBS session includes: the initial MBS QFI SN of the first MBS session, and/or the initial MBS QFI SN of at least one QoS flow of the first MBS session.
  • the initial MBS QFI SN corresponding to the first MBS session is less than or equal to the first MBS QFI SN, or the first MBS QFI SN minus the initial MBS QFI SN corresponding to the first MBS session is less than or equal to the first MBS QFI SN.
  • the first MBS QFI SN is the default MBS QFI SN of the first data packet of the first MBS session.
  • the first value is a non-negative integer less than or equal to the PDCP window size.
  • the initial MBS QFI SN and the default MBS QFI SN corresponding to the first MBS session are located within a PDCP window size.
  • the method further includes: the first core network device sends the first data packet of the first MBS session to the access network device, and the initial MBS QFI SN corresponding to the first MBS session is less than or equal to the first MBS session.
  • the MBS QFI SN of a data packet, or the MBS QFI SN of the first data packet minus the initial MBS QFI SN corresponding to the first MBS session is less than or equal to the first value, and the first value is less than or equal to the PDCP window size Nonnegative integer.
  • the actual MBS QFI SN of the first data packet and the initial MBS QFI SN corresponding to the first MBS session are located within a PDCP window size.
  • the initial HFN determined by the access network device and the initial COUNT value indicated by the reference SN and the actual MBS QFI SN of the first data packet are located within a PDCP window size, thereby enabling the terminal device to accurately obtain subsequent data packets based on the initial COUNT value. COUNT value.
  • allowing the (actual) MBS QFI SN of the first data packet, the default MBS QFI SN, and the initial MBS QFI SN corresponding to the first MBS session can improve flexibility.
  • the first process is a shared transmission channel establishment process.
  • the shared transmission channel establishment process is used to establish a shared transmission channel for the first MBS session.
  • the shared transmission channel is used between the core network and the access network. data transmission.
  • the core network side can send the initial MBS QFI SN corresponding to the first MBS session during the shared transmission channel establishment process, thereby reducing the service delay caused by MRB delayed configuration and improving the access network equipment's reception Accuracy of the initial HFN and reference SN configured before the packet.
  • the shared transmission channel establishment process it means that the access network device triggers the establishment of a shared transmission channel with the core network, and the access network device needs to configure MRB to send service data to the terminal device.
  • the access network device cannot determine the initial HFN and reference SN in the MRB configuration until the device receives the first data packet from the core network through this transmission channel.
  • the access network equipment When the initial MBS QFI SN is configured in the shared transmission channel establishment process, since the access network equipment needs to configure the MRB, the access network equipment will use the initial MBS QFI SN to determine the initial HFN and reference SN to avoid the initial configuration of the core network. MBS QFI SN but the access network equipment is not used, thereby avoiding waste of communication resources.
  • the first core network device sends the initial MBS QFI SN corresponding to the first MBS session to the network device, including: the first core network device sends a first message to the network device, the first message includes the first The initial MBS QFI SN corresponding to the MBS session.
  • the first message is used to carry address information of the shared transmission channel and/or status information of the first MBS session.
  • the first process is a PDU session establishment process or a PDU session modification process.
  • the PDU session establishment process is used to establish or modify the first MBS session
  • the PDU session modification process is used to establish or modify the first MBS session.
  • the core network side can send the initial MBS QFI SN corresponding to the first MBS session in the PDU session establishment process or PDU session modification process, thereby reducing the service delay caused by MRB delayed configuration and improving the access network The accuracy of the initial HFN and reference SN configured by the device before receiving the packet.
  • the first process is an MBS session update process.
  • This MBS session update process is used to add QoS flow in the first MBS session.
  • the core network side can send the initial MBS QFI SN corresponding to the first MBS session in the MBS session update process.
  • the access network device needs to configure MRB, it can reduce the service time caused by delayed MRB configuration. delay, improving the accuracy of the initial HFN and reference SN configured by the access network device before receiving the data packet.
  • the first process is a multicast session activation process.
  • the multicast session activation process is used to activate the first MBS session.
  • the core network side can send the initial MBS QFI SN corresponding to the first MBS session during the multicast session activation process.
  • the access network device needs to configure MRB, it can reduce the business caused by delayed MRB configuration. Delay, improve the accuracy of the initial HFN and reference SN configured by the access network device before receiving the data packet.
  • the first core network device sends the initial MBS QFI SN corresponding to the first MBS session to the network device, including: the first core network device sends the second message to the network device.
  • the second message includes the initial MBS QFI SN corresponding to the first MBS session, and the second message is used to carry the identity of the first MBS session.
  • the method further includes: the first core network device sending the first information to the network device.
  • the first information indicates whether the MBS QFI SN corresponding to the first MBS session is continuous or reset when the first MBS session is deactivated and then reactivated.
  • sending the first information to the network device by the first core network device includes: the first core network device sends a third message to the network device, where the third message includes the first information.
  • the third message is used to request the establishment or modification of the first MBS session; or the third message is used to deactivate the first MBS session; or the third message is used to activate the first MBS session; or the third message is used to The first MBS session is updated; or, the third message is used to establish a shared transmission channel of the first MBS session.
  • the first core network device obtains the initial MBS QFI SN corresponding to the first MBS session, including: the first core network device The network device receives the initial MBS QFI SN corresponding to the first MBS session from the second core network device.
  • the method further includes: the first core network device sends second information to the second core network device, and the second information is used to request the initial MBS QFI SN corresponding to the first MBS session.
  • the method further includes: the first core network device sending a fourth message to the second core network device, the fourth message being used to request establishment or modification of a Packet Forwarding Control Protocol PFCP session.
  • the first core network device receives the initial MBS QFI SN corresponding to the first MBS session from the second core network device, including: the first core network device receives the fifth message from the second core network device, and the fifth message includes the first MBS The initial MBS QFI SN corresponding to the session, and the fifth message is the response message of the fourth message.
  • the method also includes: the first core network device sends the initial MBS QFI SN or the first MBS QFI SN corresponding to the first MBS session to the second core network device, and the first MBS QFI SN is the first Default MBS QFI SN for packets.
  • the first core network device sends the initial MBS QFI SN or the first MBS QFI SN corresponding to the first MBS session to the second core network device, including: the first core network device sends the first MBS QFI SN to the second core network device.
  • Send a fourth message is used to request the establishment or modification of a PFCP session.
  • the fourth message includes the initial MBS QFI SN or the first MBS QFI SN corresponding to the first MBS session.
  • the method also includes: the first core network device receives a fifth message from the second core network device, and the fifth message is a response message to the fourth message; when the fifth message indicates that the PFCP session is established or modified successfully, instructs the second core network
  • the device accepts the initial MBS QFI SN or the first MBS QFI SN corresponding to the first MBS session.
  • the first core network device determines the initial MBS QFI SN corresponding to the first MBS session, including: the first core network device receives second information from the second core network device, and the second information is used to Request the initial MBS QFI SN corresponding to the first MBS session; the first core network device determines the initial MBS QFI SN corresponding to the first MBS session based on the second information.
  • the first core network device determines the initial MBS QFI SN corresponding to the first MBS session, including: the first core network device receives a fourth message from the second core network device, and the fourth message is used to request Establish or modify the PFCP session; the first core network device determines the initial MBS QFI SN corresponding to the first MBS session according to the fourth message.
  • a communication method is provided.
  • the method can be executed by the access network device, or by components of the access network device, such as the processor, chip, or chip system of the access network device. It can also be executed by It is implemented by logical modules or software that can realize all or part of the access network equipment functions.
  • the method includes: the access network device receives the initial MBS QFI SN corresponding to the first multicast broadcast service MBS session from the session management network element in the first process.
  • the first process is for the access network device to receive the first MBS QFI SN of the first MBS session.
  • the process before a packet.
  • the access network device determines the initial superframe number HFN and reference SN based on the initial MBS QFI SN of the first MBS session, and sends the initial HFN and reference SN to the terminal device.
  • the access network device can receive the initial MBS QFI SN corresponding to the first MBS session from the core network side before receiving the first data packet of the first MBS session, so that the access network device can according to the initial MBS
  • the QFI SN determines the initial HFN and reference SN, thereby configuring the initial HFN and reference SN to the terminal device, so that the access network device can promptly configure the MRB for the terminal device without waiting for the arrival of the data packet, indicating the initial HFN and reference SN.
  • the core network side may eventually use the initial MBS QFI SN as the MBS QFI SN of the first data packet, or determine the first MBS QFI SN based on the initial MBS QFI SN. MBS QFI SN of each data packet, thereby improving the accuracy of the initial HFN and reference SN configured by the access network device before receiving the data packet.
  • the first process is a shared transmission channel establishment process.
  • the shared transmission channel establishment process is used to establish a shared transmission channel for the first MBS session.
  • the shared transmission channel is used for data between the core network and the access network. transmission.
  • the access network device receives the initial MBS QFI SN corresponding to the first MBS session from the session management network element, including: the access network device receives the first message from the session management network element, the first message Including the initial MBS QFI SN corresponding to the first MBS session, the first message is used to carry the address information of the shared transmission channel, and/or the status information of the first MBS session.
  • the first process is a PDU session establishment process or a PDU session modification process.
  • the PDU session establishment process is used to establish or modify the first MBS session
  • the PDU session modification process is used to establish or modify the first MBS session.
  • the first process is an MBS session update process
  • the MBS session update process is used to add a QoS flow in the first MBS session.
  • the first process is a multicast session activation process
  • the multicast session activation process is used to activate the first MBS session.
  • the access network device receives the initial MBS QFI SN corresponding to the first MBS session from the session management network element, including: the access network device receives a second message from the session management network element, and the second message Includes the initial MBS QFI corresponding to the first MBS session SN, the second message is used to carry the identity of the first MBS session.
  • a communication method is provided, which method can be executed by the first core network device or by components of the first core network device, such as the processor, chip, or chip system of the first core network device. , and can also be implemented by a logic module or software that can realize all or part of the functions of the first core network equipment.
  • the method includes: a first core network device obtains first information and sends the first information to a network device. Wherein, the first information indicates whether the MBS quality of service stream identifier QFI sequence number SN of the first MBS session is continuous or reset when the first MBS session is deactivated and then reactivated.
  • the MBS QFI SN corresponding to the first MBS session is discontinuous or reset, so that the access network device can When a deactivation request is issued for an MBS session, the MRB of the first MBS session is released, so that the access network device can release the MRB as early as possible.
  • the access network device can release the MRB of the first MBS session and then create a new MRB, so that the access network device can establish the MRB before the MBS session is activated. Compared with MBS Establishing an MRB after the session is activated can reduce service latency.
  • sending the first information to the network device by the first core network device includes: the first core network device sends a third message to the network device, where the third message includes the first information.
  • the third message is used to request the establishment or modification of the first MBS session; or the third message is used to deactivate the first MBS session; or the third message is used to activate the first MBS session; or the third message is used to The first MBS session is updated; or, the third message is used to establish a shared transmission channel of the first MBS session.
  • the method further includes: the first core network device sending the initial MBS QFI SN of the first MBS session to the network device in the first process.
  • the initial MBS QFI SN corresponding to the first MBS session is used to determine the initial superframe number HFN and reference SN.
  • the first process is the process before sending the first data packet of the first MBS session to the access network device.
  • the access network device can configure the MRB for the terminal device according to the initial MBS QFI SN of the first MBS session, thereby improving the accuracy of the initial HFN and reference SN configured by the access network device.
  • a fourth aspect provides a communication device for implementing various methods.
  • the communication device may be the first core network device in the first aspect or the third aspect, or a device included in the first core network device, such as a chip or chip system or module; or the communication device may be the second aspect Access network equipment in access network equipment, or devices included in access network equipment, such as chips or chip systems or modules.
  • the communication device includes modules, units, or means (means) corresponding to the implementation method.
  • the modules, units, or means can be implemented by hardware, software, or by hardware executing corresponding software.
  • the hardware or software includes one or more modules or units corresponding to functions.
  • the communication device may include a processing module and a transceiver module.
  • This processing module can be used to implement the processing functions in any of the above aspects and any possible implementation manner thereof.
  • the transceiver module which may also be called a transceiver unit, is used to implement the sending and/or receiving functions in any of the above aspects and any possible implementation manner thereof.
  • the transceiver module can be composed of a transceiver circuit, a transceiver, a transceiver or a communication interface.
  • the transceiver module includes a sending module and/or a receiving module, respectively used to implement the sending or receiving function in any of the above aspects and any possible implementation thereof.
  • a communication device including: a processor and a communication interface; the communication interface is used to communicate with modules external to the communication device; the processor is used to execute computer programs or instructions to enable the communication device Perform the methods described in either aspect.
  • the communication device may be the first core network device in the first aspect or the third aspect, or a device included in the first core network device, such as a chip or chip system or module; or the communication device may be the second aspect Access network equipment in access network equipment, or devices included in access network equipment, such as chips or chip systems or modules.
  • a communication device including: at least one processor; the processor is configured to execute a computer program or instructions stored in a memory, so that the communication device executes the method described in any aspect.
  • the memory may be coupled to the processor, or the memory may exist independently of the processor. For example, the memory and the processor may be two independent modules.
  • the memory may be located outside the communication device or within the communication device.
  • the communication device may be the first core network device in the first aspect or the third aspect, or a device included in the first core network device, such as a chip or chip system or module; or the communication device may be the second aspect Access network equipment in access network equipment, or devices included in access network equipment, such as chips or chip systems or modules. When the device is a chip system, it may be composed of a chip or may include a chip and other discrete components.
  • a computer-readable storage medium stores computer programs or instructions, which when run on a communication device, enable the communication device to perform the method described in any aspect.
  • An eighth aspect provides a computer program product containing instructions that, when run on a communication device, enable the communication device to perform the method described in any aspect.
  • the sending action/function can be understood as outputting information
  • the receiving action/function can be understood as inputting information
  • the technical effects brought by any design method in the fourth to eighth aspects can be referred to the technical effects brought by different design methods in the first aspect, the second aspect, or the third aspect, and will not be described again here. .
  • FIG. 1 is a schematic structural diagram of a COUNT provided by this application.
  • Figure 2 is a schematic structural diagram of a communication system provided by this application.
  • FIG. 3 is a schematic structural diagram of another communication system provided by this application.
  • FIG. 4 is a schematic structural diagram of another communication system provided by this application.
  • Figure 5 is a schematic structural diagram of a communication device provided by this application.
  • FIG. 6 is a schematic diagram of the transmission path of an MBS provided by this application.
  • Figure 7 is a schematic structural diagram of a user plane protocol stack provided by this application.
  • FIG. 9 is a schematic diagram of an MBS session deactivation process provided by this application.
  • FIG. 10 is a schematic diagram of an MBS session activation process provided by this application.
  • Figure 11 is a schematic flow chart of a communication method provided by this application.
  • Figure 12 is a schematic flow chart of another communication method provided by this application.
  • Figure 13 is a schematic flow chart of another communication method provided by this application.
  • Figure 14 is a schematic application flow diagram of a communication method provided by this application.
  • Figure 15 is a schematic diagram 2 of the application flow of a communication method provided by this application.
  • Figure 16 is a schematic diagram 3 of the application flow of a communication method provided by this application.
  • Figure 17 is a schematic diagram 4 of the application flow of a communication method provided by this application.
  • Figure 18a is a schematic flow chart of yet another communication method provided by this application.
  • Figure 18b is a schematic flow chart of yet another communication method provided by this application.
  • Figure 19 is a schematic structural diagram of a first core network device provided by this application.
  • Figure 20 is a schematic structural diagram of an access network device provided by this application.
  • Figure 21 is a schematic structural diagram of another communication device provided by this application.
  • Figure 22 is a schematic flow chart of yet another communication method provided by this application.
  • A/B can mean A or B; "and/or” in this application only means It is an association relationship that describes associated objects. It means that there can be three relationships.
  • a and/or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. Among them, A and B Can be singular or plural.
  • plural means two or more than two.
  • At least one of the following” or similar expressions thereof refers to any combination of these items, including any combination of a single item (items) or a plurality of items (items).
  • at least one of a, b, or c can mean: a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, c can be single or multiple .
  • words such as “first” and “second” are used to distinguish identical or similar items with basically the same functions and effects. Those skilled in the art can understand that words such as “first” and “second” do not limit the number and execution order, and words such as “first” and “second” do not limit the number and execution order.
  • words such as “exemplary” or “for example” are used to represent examples, illustrations or explanations. Any embodiment or design described as “exemplary” or “such as” in the embodiments of the present application is not to be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as “exemplary” or “such as” is intended to present related concepts in a concrete manner that is easier to understand.
  • an embodiment means that a particular feature, structure, or characteristic associated with the embodiment is included in at least one embodiment of the present application. Therefore, various embodiments are not necessarily referred to the same embodiment throughout this specification. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments. It can be understood that in the various embodiments of the present application, the size of the sequence numbers of each process does not mean the order of execution. The execution order of each process should be determined by its functions and internal logic, and should not be determined by the execution order of the embodiments of the present application. The implementation process constitutes no limitation.
  • the technical solution provided by this application can be used in various communication systems.
  • the communication system can be a third generation partnership project (3GPP) communication system, for example, the fourth generation (4th generation, 4G) long-term evolution (long term evolution, LTE) system, fifth generation (5th generation, 5G) new radio (NR) system, vehicle to everything (V2X) system, LTE and NR hybrid networking system, or device-to-device (device-to-device, D2D) system, machine to machine (machine to machine, M2M) communication system, Internet of Things (IoT), and other next-generation communication systems, etc.
  • 3GPP third generation partnership project
  • 4G fourth generation, 4G) long-term evolution (long term evolution, LTE) system
  • 5th generation, 5G) new radio (NR) system vehicle to everything (V2X) system
  • V2X vehicle to everything
  • LTE and NR hybrid networking system or device-to-device (device-to-device, D2D) system, machine to machine (mach
  • the above-mentioned communication systems applicable to the present application are only examples.
  • the communication systems applicable to the present application are not limited to these and will be explained uniformly here, and will not be described in detail below.
  • the communication system includes access network equipment and at least one terminal equipment. Further, the communication system may also include core network equipment.
  • the core network device may include at least one of a mobility management network element, a session management network element, a multicast broadcast session management network element, or a multicast broadcast user plane network element.
  • the terminal device can access the DN through a protocol data unit (PDU) session (PDU session) from the terminal device to the access network device to the core network device to the data network (DN). Or perform business data transmission.
  • PDU protocol data unit
  • PDU session protocol data unit session
  • the terminal device may refer to a user-side device with wireless transceiver function.
  • Terminal equipment can also be called user equipment (UE), terminal, etc.
  • the terminal device can be a drone, an IoT device (for example, a sensor, an electric meter, a water meter, etc.), a V2X device, a station (ST) in a wireless local area network (WLAN), or a personal digital processing device.
  • PDA personal digital assistant
  • wearable device also known as wearable smart device
  • tablet computer or belt A computer with wireless transceiver function or it can be a virtual reality (VR) terminal, industrial control, self-driving, remote medical, smart grid, transportation Wireless terminals in transportation safety, smart city, and smart home; or, they can be vehicle-mounted terminals, vehicles with vehicle-to-vehicle (V2V) communication capabilities, smart Connected vehicles, drones with UAV to UAV (U2U) communication capabilities, etc.
  • VR virtual reality
  • the access network device is a network-side device with wireless transceiver function, which can be an evolutionary base station (eNB or eNodeB) in LTE or evolved LTE system (LTE-Advanced, LTE-A). ), such as traditional macro base station eNB and micro base station eNB in heterogeneous network scenarios; or it can be the next generation node B (next generation node B, gNodeB or gNB) in the 5G system; or it can be the transmission reception point (transmission reception point, TRP); or it can be a base station in the future evolved public land mobile network (public land mobile network, PLMN); or it can be a broadband network service gateway (broadband network gateway, BNG), aggregation switch or non-3GPP access equipment ; Or it can be a wireless controller in a cloud radio access network (CRAN); or it can be an access point (AP) in a WiFi system; or it can be a wireless relay node or wireless backend Transmission node; or it can be a wireless
  • the access network device may refer to a centralized unit (CU), or the access network device may be composed of a CU and a distributed unit (DU).
  • CU and DU can be divided according to the protocol layer of the wireless network.
  • RRC radio resource control
  • SDAP service data adaptation protocol
  • PDCP packet data convergence protocol
  • RLC radio link control
  • MAC media access control
  • PHY physical
  • a CU may be composed of a CU control plane (CU control plane, CU-CP) and a CU user plane (CU user plane, CU-UP).
  • CU control plane CU control plane, CU-CP
  • CU user plane CU-UP
  • the mobility management network element is mainly used for attachment of terminal devices in the mobile network, mobility management, tracking area update process, etc.
  • the mobility management network element terminates non-access stratum (NAS) messages, completes registration management, connection management and reachability management, allocates tracking area list (track area list, TA list) and mobility management, etc., and Transparently route session management (SM) messages to session management network elements.
  • NAS non-access stratum
  • the mobility management network element can be an access and mobility management function (AMF) network element.
  • AMF access and mobility management function
  • future communications such as sixth generation (6G) communications, the mobility management network element may still be an AMF network element or have other names, which is not limited in the embodiments of this application.
  • the session management network element is mainly responsible for session management in the mobile network, such as managing the establishment, modification, and release of sessions.
  • the session management network element may be a session management function (SMF) network element.
  • SMS session management function
  • future communications such as 6G communications
  • the session management network element may still be an SMF network element or have other names, which is not limited in the embodiments of this application.
  • the multicast broadcast session management network element is mainly responsible for session management of multicast and broadcast service (MBS) in the mobile network.
  • the multicast broadcast session management network element can be a multicast and broadcast (MB) SMF network element, that is, an MB-SMF network element.
  • the multicast broadcast session management network element may still be an MB-SMF network element or have other names, which is not limited in the embodiments of this application.
  • the session management network element in this application can also participate in MBS session management and other MBS-related processes.
  • the multicast broadcast user plane network element is mainly responsible for processing MBS messages, such as forwarding and accounting.
  • the multicast broadcast user plane network element can be an MB user plane function (UPF) network element, that is, an MB-UPF network element.
  • UPF MB user plane function
  • future communications such as 6G communications
  • multicast broadcast user plane network elements may still be MB-UPF network elements, or have other names, which are not limited in the embodiments of this application.
  • the function of the multicast broadcast user plane network element in this application can also be implemented by the user plane network element, that is, the multicast broadcast user plane network element in this application can be replaced by a user plane network element.
  • FIG. 5 is a schematic diagram of the composition of a communication device 500 provided by this application.
  • the communication device 500 can be a terminal device or a chip or a system on a chip in the terminal device; or, it can be an access network device or a module in the access network device. Or a chip or a system on a chip; or, it can be a core network device or a module or a chip or a system on a chip in the core network device.
  • the communication device 500 includes at least one processor 501 and at least one communication interface (FIG. 5 is only an example of including a communication interface 504 and a processor 501 for illustration).
  • the communication device 500 may also include a communication bus 502 and a memory 503 .
  • the processor 501 can be a general central processing unit (CPU), a general processor, a network processor (NP), a digital signal processor (DSP), a microprocessor, or a microcontroller device, programmable logic device (PLD), or any combination thereof.
  • the processor 501 can also be other devices with processing functions, such as circuits, devices or software modules, without limitation.
  • the communication bus 502 is used to connect different components in the communication device 500 so that different components can communicate.
  • the communication bus 502 may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc.
  • PCI peripheral component interconnect
  • EISA extended industry standard architecture
  • the bus can be divided into address bus, data bus, control bus, etc. For ease of presentation, only one thick line is used in Figure 5, but it does not mean that there is only one bus or one type of bus.
  • Communication interface 504 is used to communicate with other devices or communication networks.
  • the communication interface 504 can be a module, a circuit, a transceiver Or any device capable of communication.
  • the communication interface 504 may also be an input/output interface located within the processor 501 to implement signal input and signal output of the processor.
  • Memory 503 may be a device with a storage function, used to store instructions and/or data. Wherein, the instructions may be computer programs.
  • the memory 503 may be a read-only memory (ROM) or other types of static storage devices that can store static information and/or instructions, or may be a random access memory (RAM). or other types of dynamic storage devices that can store information and/or instructions, and 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 compressed optical discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, etc., are not restricted.
  • ROM read-only memory
  • RAM random access memory
  • EEPROM electrically erasable programmable read-only memory
  • CD-ROM compact disc read-only memory
  • optical disc storage including compressed optical discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.
  • magnetic disk storage media or other magnetic storage devices, etc. are not restricted.
  • the memory 503 may exist independently of the processor 501 or may be integrated with the processor 501 .
  • the memory 503 may be located within the communication device 500 or outside the communication device 500, without limitation.
  • the processor 501 can be used to execute instructions stored in the memory 503 to implement the methods provided by the following embodiments of the application.
  • the communication device 500 may also include an output device and an input device (not shown in Figure 5).
  • Output devices communicate with processor 501 and can display information in a variety of ways.
  • Input devices communicate with processor 501 and can receive user input in a variety of ways.
  • access network equipment, core network equipment, or terminal equipment may include more or less components than shown in the figures, or some components may be combined, or some components may be separated, or Different component arrangements.
  • the components illustrated may be implemented in hardware, software, or a combination of software and hardware.
  • Multicast broadcast service MBS 1. Multicast broadcast service MBS:
  • MBS is a service for multiple terminal devices.
  • Common MBS include live broadcast services, public safety services, batch software update services, etc. From the end-to-end management control process and transmission method, MBS can be divided into multicast service and broadcast service.
  • MBS multicast services and broadcast services
  • This application does not specifically limit the name of MBS.
  • MBS may also have Other names.
  • Multicast services usually have higher quality of service (QoS) requirements, and multicast services can reach the same QoS level as unicast services.
  • QoS quality of service
  • the core network equipment can manage the terminal equipment to join or leave the multicast service group, and the access network equipment and the core network equipment can maintain the information of the terminal equipment in the multicast service group.
  • the MBS server can send MBS data to the core network device.
  • multicast services are transmitted through MBS sessions, and MBS sessions include MBS QoS flows (or multicast QoS flows (multi-cast QoS flow)).
  • MBS session can be associated with the PDU session of the terminal device, and the MBS QoS flow is associated with the unicast QoS flow in the PDU session.
  • the core network device can control the status of the MBS session to be activated or deactivated, and the terminal device does not perceive the status of the MBS session.
  • PTM point to multi-point
  • PTP point to point
  • MBS session in this application can also be called a multicast session, and the two can be replaced with each other.
  • MBS sessions can correspond to MBS one-to-one.
  • An MBS and its corresponding MBS session can be represented by the same identifier.
  • both MBS and MBS sessions can be identified by the temporary multicast group identifier (TMGI). . Therefore, MBS session and MBS in this application can also be replaced with each other.
  • TMGI temporary multicast group identifier
  • the protocol stack on the wireless access network side can be divided into a user plane protocol stack and a control plane protocol stack.
  • the user plane protocol stack can include a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a media interface layer. Access control (media access control, MAC) layer and physical (physical, PHY) layer, etc.
  • the physical layer belongs to the first layer (also called layer 1 (L1)), and the MAC layer, RLC layer, PDCP layer, and SDAP layer belong to the second layer (also called layer 2 (L2) ).
  • the radio resource control (RRC) layer of the control plane belongs to the third layer (also called layer 3 (L3)).
  • the SDAP layer is located above the PDCP layer
  • the PDCP layer is located above the RLC layer
  • the RLC layer is located above the MAC layer
  • the MAC layer is located above the physical layer.
  • each protocol layer processes the data packets in sequence from top to bottom as shown in Figure 7, and finally transmits them to the terminal device through the air interface.
  • the terminal device After receiving the data packet at the air interface, the terminal device processes the data packet accordingly in the reverse order of the access network device.
  • the processing of data packets by each protocol layer The reason is that the multi-function entity corresponding to the protocol layer is implemented.
  • the processing of the PDCP layer is implemented by the corresponding PDCP layer entity.
  • the service provided by Layer 2 to transmit user data between terminal equipment and access network equipment can be called a radio bearer (RB).
  • RB radio bearer
  • MBS the service provided by layer 2 to transmit user data between terminal equipment and access network equipment
  • MRB the service of transmitting user data between the terminal device and the access network device can be implemented by each protocol layer belonging to layer 2 mentioned above.
  • the user plane protocol stack shown in Figure 7 does not constitute any limitation on the solution of this application. In actual applications, the user plane protocol stack may include more or fewer protocol layers than shown.
  • the multicast service establishment process may include the following steps:
  • the UE sends a PDU Session Modification Request (PDU Session Modification Request) message to the AMF network element.
  • the AMF network element receives the PDU session modification request message from the UE.
  • the PDU session modification request message may include an identifier (ID) of the MBS session, such as TMGI, indicating the multicast group that the UE requests to join.
  • ID an identifier of the MBS session
  • the PDU session modification request message is a NAS message. After receiving the PDU session modification request message, the AMF network element can send it to the SMF network element.
  • the AMF network element sends a PDU Session Setup Request (PDU Session Setup Request) message or a PDU Session Modification Request (PDU Session Modification Request) message to the gNB.
  • the gNB receives the PDU session establishment request message or the PDU session modification request message from the AMF network element.
  • the PDU session establishment request message or the PDU session modification request message may include multicast session information and PDU session modification information.
  • the multicast session information may include information related to the MBS session (or multicast group) that the UE requests to join.
  • the PDU session modification information may indicate the PDU session associated with the MBS session, the unicast QoS flow associated with the QoS flow of the MBS session, etc.
  • step S803 After gNB receives the PDU session establishment request message or PDU session modification request message, if the shared transmission channel of the MBS session that the UE requests to join is not established, the following step S803 is performed.
  • the shared transmission channel is used for data transmission between the core network and the access network.
  • the network elements involved in step S803 may include gNB, AMF network element, SMF network element, MB-SMF network element, or MB-UPF network element, etc.
  • Figure 8 only shows the gNB, AMF network element, and MB-UPF network element involved, but it does not limit the network elements participating in step S803 to only gNB, AMF network element, and MB-UPF network element. .
  • the gNB sends an RRC message to the UE.
  • the RRC message may include an N1 session management (SM) container (such as a PDU Session Modification Command (PDU Session Modification Command)) and MRB configuration information (used to establish an MRB for the above-mentioned MBS session) .
  • SM session management
  • PDU Session Modification Command PDU Session Modification Command
  • MRB configuration information used to establish an MRB for the above-mentioned MBS session
  • the PDU session modification command may be generated by the AMF network element and sent to the UE through the gNB.
  • the gNB sends a PDU Session Setup Response (PDU Session Setup Response) message or a PDU Session Modification Response (PDU Session Modification Response) message to the AMF network element.
  • PDU Session Setup Response PDU Session Setup Response
  • PDU Session Modification Response PDU Session Modification Response
  • the AMF network element receives the PDU session establishment response message or the PDU session modification response message from the gNB.
  • the PDU session establishment response message or the PDU session modification response message may reply to the multicast service establishment status, for example, reply to the multicast service establishment success, etc.
  • the MB-UPF network element sends multicast data to gNB through the MBS session.
  • gNB receives multicast data from the MB-UPF network element.
  • the gNB sends multicast data to the UE through the MRB.
  • the UE receives multicast data from the gNB.
  • Figure 8 only shows some steps in the multicast service session establishment process and the implementation of some core network devices (such as AMF network elements).
  • the multicast service session establishment process may involve more network elements than shown in Figure 8 and include more steps than shown in Figure 8 .
  • the MBS session activation process may include the following steps:
  • the AMF network element sends a multicast session deactivation request (Multicast Session Deactivation Request) message to the gNB.
  • gNB receives the multicast session deactivation request message from the AMF network element.
  • the MBS session deactivation process can be triggered by the MB-SMF network element.
  • the MB-SMF network element can receive the application
  • the deactivation process of the MBS session is triggered when the application function (AF) network element deactivates a request or receives a notification from the MB-UPF network element (the MB-UPF network element notifies that there is no downlink data transmission within a period of time).
  • AF application function
  • gNB sets the status of the MBS session to deactivated.
  • gNB sends a multicast session deactivation response (Multicast Session Deactivation Response) message to the AMF network element.
  • the AMF network element receives the multicast session deactivation response message from the gNB.
  • the multicast session deactivation response message may reply to the deactivation status of the MBS session, for example, reply to the successful deactivation of the MBS session.
  • the AMF network element can send a response message to the MB-SMF network element to reply to the deactivation status of the MBS session.
  • the gNB stops transmitting MBS session data to the UE.
  • the gNB can also release the UE connection.
  • the release of the UE connection can be achieved through an RRC message.
  • the gNB may not release the UE connection.
  • the UE is not aware of the deactivation of the MBS session, and no explicit deactivation notification is sent to the UE from the network side.
  • Figure 9 only shows some steps in the MBS session deactivation process and the implementation of some core network devices (such as AMF network elements).
  • the MBS session deactivation process may involve more network elements than shown in Figure 9, and include more steps than shown in Figure 9.
  • the MBS session activation process may include the following steps:
  • the AMF network element sends a multicast session activation request (Multicast Session Activation Request) message to the gNB.
  • gNB receives the multicast session activation request message from the AMF network element.
  • the MBS session activation process can be triggered by the MB-SMF network element.
  • the MB-SMF network element can trigger an MBS session when receiving an activation request from an application function (AF) network element or receiving a notification from an MB-UPF network element (notification about downlink MBS data).
  • AF application function
  • MB-UPF notification about downlink MBS data
  • gNB sends a multicast session activation response (Multicast Session Activation Response) message to the AMF network element.
  • the AMF network element receives the multicast session activation response message from the gNB.
  • the multicast session activation response message may reply to the activation status of the MBS session, for example, reply that the MBS session activation is successful.
  • the AMF network element can send a response message to the MB-SMF network element to reply to the activation status of the MBS session.
  • the gNB can transmit MBS session data to the UE.
  • Figure 10 only shows some steps in the MBS session activation process and the implementation of some core network devices (such as AMF network elements).
  • the MBS session activation process may involve more network elements than shown in Figure 10, and include more steps than shown in Figure 10.
  • the core network device can generate MBS QFI SN for the data packet of the multicast service. . After each access network device receives a data packet from the core network, it can generate the same COUNT value based on the MBS QFI SN of the data packet.
  • QFI refers to QoS flow identifier (QFI)
  • SN refers to sequence number (SN).
  • COUNT value in this application refers to the PDCP layer COUNT value, whose structure is shown in Figure 1 and consists of a high-order super frame number (hyper frame number, HFN) and a low-order PDCP SN.
  • COUNT value in this application can also be called (or described as) "COUNT", and the two can be replaced with each other.
  • terminal devices that have joined the same multicast service one after another correspond to the same MRB on the access network device side.
  • the access network device needs to indicate the initial COUNT value to the terminal device.
  • the access network device needs to indicate the initial COUNT value to the terminal device through the multicastHFN-AndRefSN information element in the PDCP configuration.
  • this application provides a communication method so that the access network device can still indicate the initial COUNT value to the terminal device in a timely manner without receiving the data packet from the core network.
  • the execution subject can perform some or all of the steps in the embodiment of the present application. These steps or operations are only examples. The embodiment of the present application can also perform other operations or variations of various operations. In addition, various steps may be performed in a different order than those presented in the embodiments of the present application, and it may not be necessary to perform all operations in the embodiments of the present application.
  • the communication method includes the following steps:
  • the first core network device obtains the initial MBS QFI SN corresponding to the first MBS session. Among them, the initial MBS QFI SN corresponding to the first MBS session is used to determine the initial HFN and reference SN.
  • the initial MBS QFI SN in this application is essentially a sequence number or number, that is, step S1101 may be: the first core network device obtains the sequence number or number corresponding to the first MBS session.
  • the initial MBS QFI SN is only an exemplary name for the serial number or number obtained by the first core network device in step S1101. This application does not specifically limit the name of the serial number or number.
  • the initial MBS QFI SN does not target a specific data packet, that is, the initial MBS QFI SN is not the MBS QFI SN of a certain data packet.
  • the MBS QFI SN of a data packet can be the same as the initial MBS QFI SN.
  • the first core network device may be one of a mobility management network element, a session management network element, a multicast broadcast session management network element, or a multicast broadcast user plane network element.
  • the initial MBS QFI SN corresponding to the first MBS session may be QoS flow granular.
  • the initial MBS QFI SN corresponding to the first MBS session includes the initial MBS QFI SN of at least one QoS flow of the first MBS session.
  • the initial MBS QFI corresponding to the first MBS session may include at least one of the following: the initial MBS QFI SN of QoS flow 1, the initial MBS QFI SN of QoS flow 2, or the initial MBS QFI SN of QoS flow 3.
  • the initial MBS QFI SN corresponding to the first MBS session may be MBS session granular.
  • the initial MBS QFI SN corresponding to the first MBS session includes the initial MBS QFI SN of the first MBS session.
  • the initial MBS QFI SN of the first MBS session may be the sum of the initial MBS QFI SNs of the multiple QoS flows.
  • the initial MBS QFI SN of each QoS flow of the first MBS session may be the initial MBS QFI SN of the first MBS session, that is, the initial MBS QFI SN of each QoS flow may be the same. If the first MBS session includes only one QoS flow, the initial MBS QFI SN of the first MBS session is the initial MBS QFI SN of the QoS flow.
  • the first core network device sends the initial MBS QFI SN corresponding to the first MBS session to the network device in the first process.
  • the network device receives the initial MBS QFI SN corresponding to the first MBS session from the first core network device in the first process.
  • the network device can be an access network device; or,
  • the network device can be a mobility management network element
  • the network device can be a mobility management network element or a session management network element; or,
  • the network device may be a multicast broadcast session management network element or a session management network element.
  • the first process is a process before sending the first data packet of the first MBS session to the access network device. Specifically, it may be the process before the multicast user plane network element sends the first data packet of the first MBS session to the access network device, that is, the first process is the process before the following step S1105.
  • the first process is the process before receiving the first data packet of the first MBS session. Specifically, it may be the process before receiving the first data packet of the first MBS session from the multicast broadcast user plane network element.
  • the first process can also be understood as: a process for preparing data transmission for the first MBS session, or a process for preparing for data transmission for the first MBS session.
  • the first core network device when the first core network device is not a multicast broadcast user plane network element, since the first core network device can learn what type of process the first process is, through this process type, the first core network device can It is learned that the first process is the process before the multicast broadcast user plane network element sends the first data packet of the first MBS session to the access network device.
  • the first process is the process before the multicast broadcast user plane network element sends the first data packet of the first MBS session to the access network device.
  • the initial MBS QFI SN corresponding to the first MBS session may be less than or equal to the first MBS QFI SN, or the first MBS QFI SN minus the initial MBS QFI SN corresponding to the first MBS session may be less than or equal to the first value.
  • the first MBS QFI SN is the default MBS QFI SN of the first data packet. If the initial MBS QFI SN corresponding to the first MBS session is the MBS session granularity, the first MBS QFI SN (or the first data packet) is also the session granularity.
  • the first MBS QFI SN (or the first data packet) is also the QoS flow granularity.
  • the initial MBS QFI SN corresponding to the first MBS session includes the initial MBS QFI SN of QoS flow 1, the initial MBS QFI SN of QoS flow 2, and the initial MBS QFI SN of QoS flow 3, correspondingly, the first MBS QFI SN Including the default MBS QFI SN of the first packet of QoS flow 1, the default MBS QFI SN of the first packet of QoS flow 2, and the default MBS QFI SN of the first packet of QoS flow 3.
  • the initial MBS QFI SN of each QoS flow and its default MBS QFI SN satisfy the above relationship.
  • the first value is a non-negative integer less than or equal to the PDCP window size.
  • the dimension of the PDCP window size may be a sequence number or number.
  • the PDCP window size is X, which may mean that the PDCP window includes X sequence numbers or numbers.
  • the PDCP window size may be 2 PDCP-SN-Size-1 .
  • PDCP-SN-Size represents the size of the PDCP SN.
  • the size of the PDCP SN may be determined by the access network device and indicated to the first core network device. The value may be, for example, 18 bits or 12 bits. If the access network device does not indicate the size of the PDCP SN to the first core network device, the first core network device may default the PDCP SN size to 12 bits.
  • the PDCP window size can also be a fixed value, and the optional value can be related to PDCP-SN-Size.
  • the size of the PDCP SN can also be understood as the number of bits (or the number of bytes) occupied by the PDCP SN, or as the length of the PDCP SN, and the three can be replaced with each other.
  • the size of HFN can also be understood as the number of bits occupied by HFN or the length of HFN.
  • the first numerical value may be a specific non-negative integer.
  • the protocol may specify the size of the first value.
  • the communication method may also include the following steps:
  • the access network device determines the initial HFN and reference SN based on the initial MBS QFI SN corresponding to the first MBS session.
  • the access network equipment can use the N high-order bits of the initial MBS QFI SN corresponding to the first MBS session as the initial HFN, and use the K low-order bits of the initial MBS QFI SN corresponding to the first MBS session.
  • the value is used as the reference SN.
  • K is the size of PDCP SN
  • N is the size of HFN.
  • the access network device can determine the initial HFN and reference SN based on the initial MBS QFI SN and offset value corresponding to the first MBS session.
  • the offset value may be less than or equal to the PDCP window size.
  • the initial MBS QFI SN corresponding to the first MBS session minus the initial HFN and the initial COUNT value indicated by the reference SN is less than or equal to the PDCP window size.
  • the access network device includes a CU. If the CU includes a CU-CP and a CU-UP, the initial HFN and reference SN may be determined by the CU-CP.
  • the initial HFN and reference SN are used to indicate the initial COUNT value.
  • the initial COUNT value can be understood as the first or first COUNT value of the MRB after the MRB is created or reconfigured.
  • this initial COUNT value can be used as the initial value of the state variable RX_DELIV.
  • the status variable RX_DELIV indicates that the terminal device has not yet submitted the COUNT value of the first (first) PDCP service data unit (service data unit, SDU) that is waiting to be submitted to the upper layer.
  • the initial HFN can be used as the HFN of the initial COUNT value
  • the reference SN can be used as the SN of the initial COUNT value
  • the access network device sends the initial HFN and reference SN to the terminal device.
  • the terminal device receives the initial HFN and reference SN from the access network device.
  • the access network device may send the initial HFN and reference SN to the terminal device during the process of creating the first MRB or reconfiguring the first MRB.
  • the first MRB is the MRB of the first MBS session.
  • the initial HFN and reference SN can be carried in the PDCP configuration. Further, it can be carried in the multicastHFN-AndRefSN information element of the PDCP configuration.
  • the terminal device can determine the initial COUNT value.
  • This initial COUNT value can be used as the initial value of the state variable RX_DELIV.
  • the subsequent terminal device receives the data packet of the first MBS session, it can determine the COUNT value of the data packet it received based on the initial value of the state variable RX_DELIV.
  • the communication method may also include the following steps:
  • the multicast broadcast user plane network element sends the data packet of the first MBS session to the access network device.
  • the access network device receives the data packet of the first MBS session from the multicast broadcast user plane network element.
  • the data packet of the first MBS session includes the first data packet of the first MBS session.
  • the (actual) MBS QFI SN of the first data packet is greater than or equal to the first MBS QFI SN.
  • the MBS QFI SN of the first data packet minus the initial MBS QFI SN corresponding to the first MBS session is less than or equal to the first value.
  • the (actual) MBS QFI SN of the first data packet, the first MBS QFI SN, and the initial MBS session corresponding to MBS QFI SN are located in one PDCP window.
  • the values of the (actual) MBS QFI SN of the first data packet, the first MBS QFI SN, and the initial MBS QFI SN corresponding to the first MBS session may be equal.
  • the (actual) MBS QFI SN of the first data packet, the first MBS QFI SN, and the initial MBS QFI SN corresponding to the first MBS session the values of any two of the three can be Equality, for example, the (actual) MBS QFI SN of the first packet and the value of the first MBS QFI SN can be equal.
  • the actual MBS QFI SN of the first data packet and the initial MBS QFI SN corresponding to the first MBS session are located within a PDCP window size.
  • the initial HFN determined by the access network device and the initial COUNT value indicated by the reference SN and the actual MBS QFI SN of the first data packet are located within a PDCP window size, thereby enabling the terminal device to accurately obtain subsequent data packets based on the initial COUNT value. COUNT value.
  • allowing the (actual) MBS QFI SN of the first data packet, the default MBS QFI SN, and the initial MBS QFI SN corresponding to the first MBS session can improve flexibility.
  • the access network device sends the data packet of the first MBS session to the terminal device.
  • the terminal device receives the data packet of the first MBS session from the access network device.
  • the access network device may send the data packet of the first MBS session to the terminal device through the first MRB.
  • the terminal device receives the data packet through the first MRB.
  • the core network device can send the initial MBS QFI SN corresponding to the first MBS session before the multicast broadcast user plane network element sends the first data packet of the first MBS session to the access network device, so that the access network
  • the device can determine the initial HFN and reference SN based on the initial MBS QFI SN, thereby configuring the initial HFN and reference SN to the terminal device, so that the access network device can promptly configure the MRB for the terminal device without waiting for the arrival of the data packet, indicating the initial HFN and reference SN.
  • the core network side may eventually use the initial MBS QFI SN as the MBS QFI SN of the first data packet, or determine the first data packet based on the initial MBS QFI SN. MBS QFI SN of a data packet, thereby improving the accuracy of the initial HFN and reference SN configured by the access network device before receiving the data packet.
  • the above has introduced the overall process of the communication method provided by this application.
  • the following describes the method and first process of obtaining the initial MBS QFI SN corresponding to the first MBS session.
  • the first core network device can obtain the initial MBS QFI SN corresponding to the first MBS session through the following three methods:
  • Method 1 The first core network device determines the initial MBS QFI SN corresponding to the first MBS session by itself.
  • the first core device may be a multicast broadcast session management network element or a multicast broadcast user plane network element.
  • the first core network device when the first core network device is a multicast broadcast user plane network element and the second core network device is a multicast broadcast session management network element, the first core network device can be based on the trigger (or request) of the second core network device. ) determine the initial MBS QFI SN corresponding to the first MBS session by itself.
  • the second core network device may send second information to the first core network device, where the second information is used to request the initial MBS QFI SN corresponding to the first MBS session.
  • the first core network device can determine the initial MBS QFI SN corresponding to the first MBS session based on the second information.
  • the first core network device may also return the initial MBS QFI SN corresponding to the first MBS session to the second core network device.
  • determining the initial MBS QFI SN corresponding to the first MBS session based on the second information can be understood as: determining the initial MBS QFI SN corresponding to the first MBS session based on the trigger or request of the second information.
  • the second information may be information in the packet forwarding control protocol (packet forwarding control protocol, PFCP) session establishment (PFCP Session Establishmen) process or the PFCP session modification process or the N4 multicast session modification (N4mb Session Modification) process.
  • PFCP packet forwarding control protocol
  • the second core network device may carry the second information in the request message of the PFCP session establishment or modification process or the N4 multicast session modification process.
  • the first core network device may return the initial MBS QFI SN corresponding to the first MBS session to the second core network device in a response message of the PFCP session establishment or modification process or the N4 multicast session modification process.
  • the second information can be implemented through a 1-bit indication.
  • the second information may be implemented by a field set to a specific value (eg set to TRUE).
  • the second information can also be realized in other ways, and this application does not specifically limit this.
  • the second core network device may send a fourth message to the first core network device, where the fourth message is used to request the establishment or modification of the PFCP session.
  • the first core network device can determine the initial MBS QFI SN corresponding to the first MBS session based on the fourth message.
  • the first core network device may also return the initial MBS QFI SN corresponding to the first MBS session to the second core network device.
  • determining the initial MBS QFI SN corresponding to the first MBS session based on the fourth message can be understood as: determining the initial MBS QFI SN corresponding to the first MBS session based on the trigger of the fourth message.
  • the fourth message may be a request message in the PFCP session establishment process or the PFCP session modification process or the N4 multicast session modification process.
  • the first core network device may return the initial MBS QFI SN corresponding to the first MBS session to the second core network device in the response message of the PFCP session establishment or modification process.
  • the first core network device determines the initial MBS QFI SN of the first MBS session by default.
  • the multicast broadcast session management network element can also send a message to the second core network device (multicast The broadcast user plane network element) sends the initial MBS QFI SN or the first MBS QFI SN, so that when the multicast broadcast user plane network element subsequently sends the first data packet of the first MBS session, it sends the initial MBS QFI SN or the first MBS QFI SN according to the initial MBS QFI SN or the first MBS QFI SN.
  • the MBS QFI SN determines the actual MBS QFI SN for this first packet.
  • the multicast broadcast session management network element may send a fourth message to the multicast broadcast user plane network element, where the fourth message includes the initial MBS QFI SN or the first MBS QFI SN corresponding to the first MBS session.
  • the fourth message is used to request to establish or modify a PFCP session or to modify an N4mb session.
  • the multicast broadcast user plane network element may send a fifth message to the multicast broadcast session management network element, where the fifth message is a response message to the fourth message.
  • the fifth message indicates that the PFCP session is successfully established or modified or indicates that the N4mb session is successfully modified, it indicates that the multicast broadcast user plane network element accepts the initial MBS QFI SN or the third MBS QFI SN corresponding to the first MBS session determined by the multicast broadcast session management network element. 1 MBS QFI SN. Subsequently, the multicast broadcast session management network element can send the initial MBS QFI SN to the mobility management network element.
  • the fifth message may also include a second MBS QFI SN, and the second MBS QFI SN may be understood as the initial MBS QFI SN recommended by the multicast broadcast user plane network element.
  • the multicast broadcast session management network element may accept or not accept the initial MBS QFI SN proposed by the multicast broadcast user plane network element.
  • the first core network device may receive the initial MBS QFI SN corresponding to the first MBS session from the second core network device. That is, the first core network device receives the initial MBS QFI SN corresponding to the first MBS session from the second core network device.
  • the first core network device may be a mobility management network element, and correspondingly, the second core network device may be a session management network element or a multicast broadcast session management network element.
  • the first core network device may be a multicast broadcast session management network element, and correspondingly, the second core network device may be a multicast broadcast user plane network element.
  • the first core network device may send the second information to the second core network device.
  • the second information is used to request the initial MBS QFI SN corresponding to the first MBS session.
  • the first core network device when the first core network device is a multicast broadcast session management network element, the first core network device may carry the second information in the request message of the PFCP session establishment or modification process.
  • the second core network device may return the initial MBS QFI SN corresponding to the first MBS session to the first core network device in the response message of the PFCP session establishment or modification process.
  • the first core network device may send a fourth message to the second core network device.
  • the fourth message is used to request establishment or modification. PFCP session or used to modify N4mb session.
  • the second core network device may return the initial MBS QFI SN corresponding to the first MBS session to the first core network device in the fifth message.
  • the fifth message is the response information of the fourth message.
  • the first core network device may receive parameters for determining the initial MBS QFI SN corresponding to the first MBS session from the second core network device, and determine the initial MBS QFI SN based on the parameters.
  • the first core network device may be a multicast broadcast session management network element, and correspondingly, the second core network device may be a multicast broadcast user plane network element.
  • the multicast broadcast user plane network element may send the first MBS QFI SN to the multicast broadcast session management network element.
  • the multicast broadcast session management network element receives the first MBS QFI SN from the multicast broadcast user plane network element, and determines the initial MBS QFI SN corresponding to the first MBS session based on the first MBS QFI SN.
  • the size relationship between the first MBS QFI SN and the initial MBS QFI SN corresponding to the first MBS session can be referred to the relevant description in the above step S1102, which will not be described again here.
  • the first core network device can send the initial MBS QFI SN corresponding to the first MBS session to the network device in the following four processes. That is, the first process can have the following four situations:
  • the first process is the shared transmission channel establishment process.
  • the shared transmission channel establishment process is used to establish a shared transmission channel for the first MBS session, and the shared transmission channel is used for data transmission between the core network and the access network.
  • the first data packet of the first MBS session may refer to the first data packet transmitted through the shared transmission channel newly created by the first process.
  • the first core network device sends the initial MBS QFI SN corresponding to the first MBS session to the network device, which may include: the first core network device sends a first message to the network device, the first message including the first MBS QFI SN corresponding to the first MBS session. Initial MBS QFI SN.
  • the first message is used to establish the shared transmission channel. Further, the first message is used to carry address information of the shared transmission channel and/or status information of the first MBS session.
  • the address information of the shared transmission channel can be, for example, Shared NG-U Multicast TNL Information (Shared NG-U Multicast TNL Information), where NG-U refers to the next generation (NG) user plane (user plane), TNL Refers to the transport network layer (TNL).
  • the address information of the shared transmission channel may indicate an NG-U tunnel address in an Internet protocol (internet protocol, IP) multicast mode.
  • the status information of the first MBS session may indicate the status of the first MBS session (MBS Session Status).
  • the first message can be a session modification response (Session Modification Response) message or PFCP session establishment response message or PFCP session modification response message.
  • Session Modification Response Session Modification Response
  • the first message may be an MBS session context update response (MBSSession_ContextUpdate Response) message.
  • MBS session context update response MBSSession_ContextUpdate Response
  • the first message may be a Distribution Setup Response message.
  • the process may include the following steps :
  • the access network device determines to establish a shared transmission channel for the first MBS session.
  • the access network device sends a distribution setup request (Distribution Setup Request) message to the AMF network element.
  • the AMF network element receives the distribution establishment request message from the access network device.
  • the distribution establishment request message may be used to request establishment of a shared transmission channel of the first MBS session.
  • the AMF network element sends an MBS session context update request (MBSSession_ContextUpdate Request) message to the MB-SMF network element.
  • MBSSession_ContextUpdate Request MBS session context update request
  • the MB-SMF network element receives the MBS session context update request message from the AMF network element.
  • the MBS session context update request message is used to request to update the context of the first MBS session.
  • the AMF network element can also store information about the access network device for the first MBS session.
  • the MB-SMF network element can store the information of the AMF network element for the first MBS session.
  • the MB-SMF network element sends a session modification request (Session Modification Request) message to the MB-UPF network element.
  • the MB-UPF network element receives the session modification request message from the MB-SMF network element.
  • the session modification request message may be used to request to establish or modify the transmission resources of the first MBS session.
  • the session modification request message in step S1404 can also be replaced with a PFCP session establishment request message or a PFCP session modification request message.
  • the MB-UPF network element sends a session modification response message to the MB-SMF network element.
  • the MB-SMF network element receives the session modification response message from the MB-UPF network element.
  • the session modification response message may include the initial MBS QFI SN corresponding to the first MBS session.
  • the method of obtaining the initial MBS QFI SN please refer to the relevant instructions mentioned above and will not be repeated here.
  • the session modification response message in step S1405 can also be replaced with a PFCP session establishment reply message or a PFCP session modification reply message.
  • the MB-SMF network element sends an MBS session context update response message to the AMF network element.
  • the AMF network element receives the MBS session context update response message from the MB-SMF network element.
  • the MBS session context update response message may include the initial MBS QFI SN corresponding to the first MBS session.
  • the initial MBS QFI SN may be carried in the session modification response message in the above step S1405, or may be determined by the MB-SMF network element itself.
  • For the method of obtaining the initial MBS QFI SN please refer to the relevant instructions mentioned above and will not be repeated here.
  • the AMF network element sends a distribution establishment response message to the access network device.
  • the access network device receives the distribution establishment response message from the AMF network element.
  • the distribution establishment response message may include the initial MBS QFI SN corresponding to the first MBS session.
  • the initial MBS QFI SN may be carried in the MBS session context update response message in step S1406 above.
  • the first process is the PDU session establishment process or the PDU session modification process.
  • the PDU session establishment process can be used to establish or modify the first MBS session, and the PDU session modification process can also be used to establish or modify the first MBS session.
  • the first data packet of the first MBS session may refer to the first data packet of the first MBS session after the establishment or modification of the first MBS session is completed.
  • the first core network device sends the initial MBS QFI SN corresponding to the first MBS session to the network device, which may include: the first core network device sends a second message to the network device, the second message includes the first MBS session corresponding Initial MBS QFI SN.
  • the second message is used to carry the identity of the first MBS session.
  • the second message can be a PDU session update session management (session management) , SM) context response (PDUSession_UpdateSMContext Response) message.
  • PDU session update session management session management
  • SM context response
  • the second message may be a PDU Session Resource Setup Request message.
  • a terminal device is the first terminal device to request to join the first MBS session among multiple terminal devices serving the access network device, then the request of the terminal device to join the first MBS session can be triggered.
  • the first core network device sends the initial MBS QFI SN corresponding to the first MBS session in the PDU session establishment process or PDU session modification process. If a terminal device is not the first terminal device to request to join the first MBS session among the multiple terminal devices served by the access network device, then the request of the terminal device to join the first MBS session will not trigger the first core network.
  • the device sends the initial MBS QFI SN corresponding to the first MBS session in the PDU session establishment process or PDU session modification process, that is, the first core network device does not send the first MBS session in the PDU session establishment process or PDU session modification process of the terminal device.
  • the initial MBS QFI SN corresponds to the first MBS session in the PDU session establishment process or PDU session modification process.
  • the terminal device sends an uplink NAS message to the AMF network element.
  • the AMF network element receives the uplink NAS message from the terminal device.
  • the NAS message may include a PDU session modification request.
  • the PDU session modification request may include an identifier of the first MBS session, indicating that the terminal device requests to join the first MBS session.
  • the AMF network element sends a PDU session update SM context request (PDUSession_UpdateSMContext Request) message to the SMF network element.
  • the SMF network element receives the PDU session update SM context request message from the AMF network element.
  • the PDU session update SM context request message is used to send the NAS message in the above step S1501.
  • the SMF network element requests the MB-UPF network element for the initial MBS QFI SN of the first MBS session through the MB-SMF network element.
  • the MB-UPF network element returns the initial MBS QFI SN of the first MBS session to the SMF network element through the MB-SMF network element.
  • the SMF network element sends a PDU session update SM context response message to the AMF network element.
  • the AMF network element receives the PDU session update SM context response message from the SMF network element.
  • the PDU session update SM context response message includes the initial MBS QFI SN of the first MBS session.
  • the AMF network element sends a PDU session resource modification request message to the access network device. corresponding.
  • the access network device receives the PDU session resource modification request message from the AMF network element.
  • the PDU session resource modification request message may include the initial MBS QFI SN of the first MBS session.
  • the access network device can interact with the terminal device in RRC messages to modify the PDU session. Afterwards, the access network device can send a PDU session resource modification response message to the AMF network element.
  • the process shown in Figure 15 is explained by taking the MB-UPF network element to determine the initial MBS QFI SN of the first MBS session as an example.
  • the initial MBS QFI SN of the first MBS session can also be determined by the MB-SMF network element.
  • the above steps S1503 and S1504 can be replaced by the following steps S1503' and S1504'.
  • the SMF network element requests the MB-SMF network element for the initial MBS QFI SN of the first MBS session.
  • the MB-SMF network element returns the initial MBS QFI SN of the first MBS session to the SMF network element.
  • the first process is the MBS session update process.
  • the MBS session update process is used to add a QoS flow in the first MBS session.
  • the following embodiments of this application refer to the QoS flow added in the first MBS session as the first QoS flow. It can be understood that the first QoS flow may refer to one or more added QoS flows.
  • the first data packet of the first MBS session may refer to: the first QoS flow of the first MBS session of the first packet.
  • the first core network device sends the initial MBS QFI SN corresponding to the first MBS session to the network device, which may include: the first core network device sends a second message to the network device, the second message includes the first MBS session corresponding Initial MBS QFI SN.
  • the second message is used to carry the identity of the first MBS session.
  • the second message may be an MBS Communication N2 Message Transfer (MBS Communication_N2Message Transfer) message.
  • the second message may be an MBS Session Update Request message.
  • the process may include the following steps :
  • the MB-SMF network element determines that the update of the first MBS session is triggered.
  • the MB-SMF network element sends message a to the MB-UPF network element.
  • the MB-UPF network element receives message a from the MB-SMF network element.
  • the message a is used to request the initial MBS QFI SN corresponding to the first MBS session.
  • the MB-UPF network element sends message b to the MB-SMF network element.
  • the MB-SMF network element receives the message b from the MB-UPF network element.
  • the message b includes the initial MBS QFI SN corresponding to the first MBS session.
  • the message b includes parameters for determining the initial MBS QFI SN.
  • the MB-SMF network element sends the MBS communication N2 message transmission message to the AMF network element.
  • the AMF network element receives the MBS communication N2 message transmission message from the MB-SMF network element.
  • the MBS communication N2 message transmission message is used to transmit updated MBS session information.
  • the MBS communication N2 message transmission message includes the initial MBS QFI SN corresponding to the first MBS session.
  • the AMF network element sends an MBS session update request message to the access network device.
  • the access network device receives the MBS session update request message from the AMF network element.
  • the MBS session update request message is used to add the first QoS flow in the first MBS session.
  • the MBS session update request message includes the initial MBS QFI SN of the first MBS session.
  • the access network device sends an RRC message to the terminal device.
  • the terminal device receives the RRC message from the access network device.
  • the RRC message may be used to reconfigure or add the MRB corresponding to the first QoS flow.
  • the RRC message may include the initial HFN and reference SN determined by the access network device.
  • the access network device sends an MBS Session Update Response message to the AMF network element.
  • the AMF network element receives the MBS session update response message from the access network device.
  • the process shown in Figure 16 is explained by taking the MB-UPF network element to determine the initial MBS QFI SN of the first MBS session as an example.
  • the initial MBS QFI SN of the first MBS session can also be determined by the MB-SMF network element.
  • the above steps S1602 and S1603 may not be executed, and the initial MBS QFI SN corresponding to the first MBS session in step S1604 is determined by the MB-SMF network element itself.
  • the first process is the multicast session activation process.
  • the multicast session activation process is used to activate the first MBS session.
  • the first data packet of the first MBS session may refer to the first data packet after the first MBS session is activated.
  • the first core network device sends the initial MBS QFI SN corresponding to the first MBS session to the network device, which may include: the first core network device sends a second message to the network device, the second message includes the first MBS session corresponding Initial MBS QFI SN.
  • the second message is used to carry the identity of the first MBS session.
  • the second message may be an MBS Communication N2 Message Transfer Request (MBS Communication_N2 Message Transfer Request) message.
  • the second message may be a multicast session activation request (Multicast Session Activation Request) message or PDU session establishment Request message.
  • the PDU session establishment request message is used to re-establish a connection for the terminal device in the RRC inactive state, so that the terminal device can receive data of the first MBS session after the first MBS session is activated.
  • the process may include the following steps :
  • the MB-SMF network element determines that the first MBS session activation is triggered.
  • the MB-SMF network element sends message a to the MB-UPF network element.
  • the MB-UPF network element receives message a from the MB-SMF network element.
  • the message a is used to request the initial MBS QFI SN corresponding to the first MBS session.
  • the MB-UPF network element sends message b to the MB-SMF network element.
  • the MB-SMF network element receives the message b from the MB-UPF network element.
  • the message b includes the initial MBS QFI SN corresponding to the first MBS session.
  • the message b includes parameters for determining the initial MBS QFI SN.
  • the MB-SMF network element sends an MBS communication N2 message transmission request message to the AMF network element.
  • the AMF network element receives the MBS communication N2 message transmission request message from the MB-SMF network element.
  • the MBS communication N2 message transmission request message is used to request activation of the first MBS session.
  • the MBS communication N2 message transmission request message includes the initial MBS QFI SN corresponding to the first MBS session.
  • the AMF network element sends a multicast session activation request message to the access network device.
  • the access network device receives the multicast session activation request message from the AMF network element.
  • the multicast session activation request message is used to request activation of the first MBS session.
  • the multicast session activation request message includes the initial MBS QFI SN of the first MBS session.
  • the access network device sends a multicast session activation response (Multicast Session Activation Response) message to the AMF network element.
  • a multicast session activation response Multicast Session Activation Response
  • the AMF network element sends an MBS Communication N2 Message Transfer Response (MBSCommunication_N2Message Transfer Response) message to the MB-SMF network element.
  • MBS Communication N2 Message Transfer Response MBS Communication N2 Message Transfer Response
  • the MB-SMF network element receives the MBS communication N2 message transmission response message from the AMF network element.
  • the process shown in Figure 17 is explained by taking the MB-UPF network element to determine the initial MBS QFI SN of the first MBS session as an example.
  • the initial MBS QFI SN of the first MBS session can also be determined by the MB-SMF network element.
  • the above steps S1702 and S1703 may not be executed, and the initial MBS QFI SN corresponding to the first MBS session in step S1704 is determined by the MB-SMF network element itself.
  • the first process is the multicast session deactivation process.
  • the multicast session deactivation process is used to deactivate the first MBS session.
  • the first data packet of the first MBS session may refer to the first data packet after the first MBS session is deactivated and then reactivated.
  • the initial MBS QFI SN corresponding to the first MBS session may be: the maximum MBS QFI SN of the first MBS session currently used when the first MBS session is deactivated.
  • the MBS QFI SN of the first data packet after deactivating the first MBS session and reactivating the first MBS session can be greater than the currently used maximum MBS QFI SN.
  • the initial MBS QFI SN may be: when deactivating the first MBS session, the maximum MBS QFI SN of the first MBS session currently used plus M, where M is a positive integer.
  • M is a positive integer.
  • the MBS QFI SN of the first data packet after deactivating the first MBS session and reactivating the first MBS session can be greater than or equal to the maximum MBS QFI SN plus M.
  • 10000 can be As the corresponding initial MBS QFI SN after the first MBS session is reactivated.
  • the first core network device sends the initial MBS QFI SN corresponding to the first MBS session to the network device, which may include: the first core network device sends a sixth message to the network device, the sixth message includes the first MBS session corresponding Initial MBS QFI SN.
  • the first core network device may be a multicast broadcast user plane network element, and the network device may be a multicast broadcast session management network element.
  • the sixth message may be a PFCP Session Modification Response message.
  • the multicast broadcast session management network element can save the initial MBS QFI SN.
  • the multicast broadcast session management network element can send its saved initial MBS QFI SN to the access network device, thereby eliminating the need to send PFCP session modifications to the multicast broadcast user plane network element.
  • Request PFCP Session Modification Request
  • the multicast broadcast session management network element sends its saved initial MBS QFI SN to the access network device when the access network device triggers the establishment of a shared transmission channel, which allows the access network device to configure MRB for the terminal device in a timely manner.
  • the access network device that triggers the establishment of the shared transmission channel may be: an access network device that has not joined the first MBS session before the first MBS session is deactivated; or an access network device that has joined the first MBS session before it is deactivated.
  • the access network device of the first MBS session may be: an access network device that has not joined the first MBS session before the first MBS session is deactivated; or an access network device that has joined the first MBS session before it is deactivated.
  • the access network device has joined the first MBS session before the first MBS session is deactivated, when the first MBS session is deactivated, the shared transmission channel between the access network device and the core network may is deleted, therefore, when the access network device joins the first MBS session again, it needs to trigger the establishment of the shared transmission channel again.
  • the first core network device may be a multicast broadcast session management network element, and the network device may be an access network device, and optionally may be a CU-CP of the access network device.
  • the sixth message may be a multicast session deactivation request (Multicast Session Deactivation Request) message.
  • the CU-CP of the access network device can save the initial MBS QFI SN.
  • the CU-CP of the access network device needs to request the maximum MBS QFI SN that has been used or will be used from the CU-UP of the access network device. COUNT value, and then configure MRB.
  • the CU-CP of the access network device since the CU-CP of the access network device saves the initial MBS QFI SN from the multicast broadcast session management network element, the CU-CP of the access network device does not need to report to the access network device
  • the CU-UP requests the maximum MBS QFI SN or COUNT value that has been used or will be used, and the MRB can be configured to the terminal device, thereby reducing the interaction between CU-CP and CU-UP and saving communication overhead.
  • the mobility management network element is the AMF network element
  • the multicast broadcast session management network element is the MB-SMF network element
  • the multicast broadcast session management network element is the MB-UPF network element
  • gNB1 is the first MBS session to be deleted. Access network equipment that has joined the first MBS session before activation.
  • gNB1 can include CU-CP.
  • the following functions implemented by gNB1 can also be implemented by the CU-CP of gNB1.
  • gNB2 is removed for the first MBS session. Taking an access network device that has not joined the first MBS session before activation as an example, the process may include the following steps:
  • the MB-UPF network element sends a PFCP Session Notification message to the MB-SMF network element.
  • the MB-SMF network element receives the PFCP session notification message from the MB-UPF network element.
  • the PFCP session notification message is used to notify the MB-SMF network element to deactivate the first MBS session.
  • the MB-UPF network element may send the PFCP session notification message when the data of the first MBS session is not received.
  • the MB-SMF network element sends a PFCP Session Modification Request message to the MB-UPF network element.
  • the MB-UPF network element receives the PFCP session modification request message from the MB-SMF network element.
  • the PFCP session modification request is used to request the MB-UPF network element to cache data, that is, to request the MB-UPF network element to cache the data of the first MBS session when it arrives instead of sending it immediately.
  • the MB-UPF network element sends a PFCP Session Modification Response message to the MB-SMF network element.
  • the MB-SMF network element receives the PFCP session modification response message from the MB-UPF network element.
  • the PFCP session modification response message may include the initial MBS QFI SN corresponding to the first MBS session.
  • the initial MBS QFI SN may be the currently used maximum MBS QFI SN, or the currently used maximum MBS QFI SN plus M.
  • the MB-SMF network element saves the initial MBS QFI SN corresponding to the first MBS session.
  • the MB-SMF network element sends a multicast session deactivation request message to gNB1.
  • gNB1 receives the multicast session deactivation request message from the MB-SMF network element.
  • the multicast session deactivation request message may include the initial MBS QFI SN corresponding to the first MBS session.
  • gNB1 sends a multicast session deactivation response message to the MB-SMF network element.
  • the MB-SMF network element receives the multicast session deactivation response message from gNB1.
  • the terminal device under gNB1 subsequently requests to join the first MBS session, the CU-CP of gNB1 does not need to request the CU-UP of gNB1 for the maximum MBS QFI SN that has been used, and can use the initial MBS QFI obtained in step S1805a.
  • SN The terminal device is configured with MRB.
  • gNB2 sends a Distribution Setup Request message to the AMF network element.
  • the AMF network element receives the distribution establishment request message from gNB2.
  • the AMF network element sends an MBS session context update request (MBSSession_ContextUpdate Request) message to the MB-SMF network element.
  • MBS session context update request (MBSSession_ContextUpdate Request) message
  • the MB-SMF network element receives the MBS session context update request message from the AMF network element.
  • step S1807a and step S1808a reference may be made to the relevant description of step S1402 and step S1403, which will not be described again here.
  • the MB-SMF network element sends an MBS session context update response message to the AMF network element.
  • the AMF network element receives the MBS session context update response message from the MB-SMF network element.
  • the MBS session context update response message may include the initial MBS QFI SN corresponding to the first MBS session.
  • the initial MBS QFI SN is saved by the MB-SMF network element in the above step S1804a. In other words, the MB-SMF network element does not need to report to the MB-UPF network
  • the primary network element requests the initial MBS QFI SN, which reduces the interaction between the MB-SMF network element and the MB-UPF network element.
  • the AMF network element sends a distribution establishment response message to the access network device.
  • the access network device receives the distribution establishment response message from the AMF network element.
  • the distribution establishment response message may include the initial MBS QFI SN corresponding to the first MBS session.
  • the initial MBS QFI SN may be carried in the MBS session context update response message in the above step S1809a.
  • the above gNB1 and gNB2 may be the same access network device, or may be different access network devices, which is not specifically limited in this application.
  • this application is not limited to sending the initial MBS QFI SN of the first MBS session in only one process.
  • the first core network device can send the initial MBS QFI SN of the first MBS session in various processes introduced in the above five situations.
  • the access network device before receiving the data packet, configures the initial HFN and reference SN to the terminal device based on the initial MBS QFI SN corresponding to the first MBS session from the core network.
  • this application also provides the following three solutions to configure the initial HFN and reference SN for the terminal equipment.
  • solution one may include the following steps:
  • the access network device configures the first MRB of the first MBS session to the terminal device before receiving the first data packet of the first MBS session.
  • the access network device may indicate the initial HFN and reference SN of the first MRB to the terminal device, and the initial HFN and reference SN indicate the initial COUNT value of the first MRB.
  • the initial HFN and reference SN may be determined by the access network equipment itself. For example, the access network device may guess an HFN and SN as the initial HFN and reference SN. For example, the initial HFN and reference SN may be zero.
  • the access network device releases the first MRB of the first MBS session and establishes the second MRB of the first MBS session.
  • the access network device can determine whether the MBS QFI SN carried in the first data packet is the same as the initial COUNT value, or the difference between the two. Whether the value is smaller than a certain threshold (such as PDCP window size). If the two are not the same or the difference is greater than or equal to the threshold, the access network device can send signaling to release the first MRB and create a second MRB. The initial COUNT value of the second MRB can be determined based on the MBS QFI SN carried in the first data packet.
  • a certain threshold such as PDCP window size
  • the signaling for releasing the first MRB and the signaling for creating the second MRB may be carried in the same message, or may be carried in different messages, which is not specifically limited in this application.
  • Solution 2 may include:
  • the access network device configures the first MRB of the first MBS session to the terminal device before receiving the first data packet of the first MBS session. Please refer to step 1) in the above solution 1, which will not be repeated here.
  • the access network device reconfigures the initial COUNT value of the first MRB.
  • the access network device can determine whether the MBS QFI SN carried in the first data packet is the same as the initial COUNT value, or the difference between the two. Whether the value is less than some threshold (e.g. half the PDCP window size). If the two are not the same or the difference is greater than or equal to the threshold, the access network device can send an RRC reconfiguration message to reconfigure the initial COUNT value of the first MRB. The reconfigured initial COUNT value can be based on the value in the first data packet. The MBS QFI SN carried is confirmed.
  • some threshold e.g. half the PDCP window size
  • the terminal device may reply an RRC reconfiguration complete message to the access network device.
  • the access network equipment includes CU-UP and CU-CP
  • CU-UP can temporarily not send the data packet to the terminal device after receiving the data of the first MBS session.
  • CU-CP receives data from the terminal device.
  • the CU-UP can be notified to start sending the data of the first MBS session.
  • the access network equipment can promptly configure the MRB for the terminal equipment without waiting for the arrival of data packets, indicating the initial HFN and reference SN.
  • solution three may include:
  • the access network device may not configure the MRB for the terminal device temporarily until the access network device receives the third request message from the core network.
  • a data packet (carrying MBS QFI SN). That is, the access network device configures the MRB to the terminal device after receiving the first data packet, and indicates the initial COUNT value to the terminal device based on the MBS QFI SN of the first data packet.
  • the PDU session establishment request message or the PDU session modification request message please refer to the relevant description in the above step S802.
  • the distribution establishment response message please refer to the relevant description in step S1402 above, which will not be described again here.
  • the access network device can send communication information to the terminal device to Notify the terminal device that MRB is not configured temporarily.
  • the access network device can indicate the initial COUNT value to the terminal device based on the MBS QFI SN of the first data packet, which can improve the accuracy of the configured initial COUNT value.
  • this application also provides a communication method.
  • the communication method may include the following steps:
  • the first core network device obtains the first information.
  • the first information indicates whether the MBS QFI SN corresponding to the first MBS session is continuous or reset when the first MBS session is deactivated and then reactivated.
  • the first core network device may be a multicast broadcast session management network element or a mobility management network element.
  • obtaining the first information by the first core network device may include: the mobility management network element receiving the first information from the multicast broadcast session management network element.
  • the first core network device sends the first information to the network device.
  • the network device receives the first information from the first core network device.
  • the network device when the first core network device is a multicast broadcast session management network element, the network device may be a mobile management network element. After receiving the first information, the mobility management network element may send the first information to the access network device.
  • the network device When the first core network device is a mobility management network element, the network device may be an access network device.
  • the first core network device may send a third message to the network device, where the third message carries the first information.
  • the third message may be used to request the establishment or modification of the first MBS session.
  • the third message may be a PDU session update SM context response message or a PDU session resource modification request message.
  • the third message may be used to deactivate the first MBS session.
  • the third message may be a multicast session deactivation request message or the like.
  • the third message may be used to activate the first MBS session.
  • the third message may be a multicast session activation request message or the like.
  • the third message may be used to update the first MBS session.
  • the third message may be an MBS session update request message or the like.
  • the third message may be used to establish a shared transmission channel of the first MBS session, and the third message may be a distribution establishment response message, or the like.
  • the first core network device can also send the initial MBS QFI SN corresponding to the first MBS session to the network device. Please refer to the relevant descriptions in Figure 11 to Figure 18a above, which will not be described again here.
  • the MBS QFI SN corresponding to the first MBS session is discontinuous or reset, and the access network device receives the first MBS session
  • the MRB of the first MBS session can be released, so that the access network device can release the MRB as early as possible.
  • the access network device can release the MRB of the first MBS session and create a new MRB.
  • the access network device may reconfigure the MRB of the first MBS session.
  • the access network device when the access network device creates or reconfigures the MRB of the first MBS session after receiving the activation request of the first MBS session, it can determine the initial HFN and reference SN based on the initial MBS QFI SN corresponding to the first MBS session. and indicates the initial HFN and reference SN to the terminal equipment.
  • the access network device can configure MRB for the terminal device without waiting for the first data packet of the service when the MBS session is activated.
  • the accuracy of configuring the initial HFN and reference SN can be improved.
  • the delay can be reduced.
  • the first core network device sends the initial MBS QFI SN to the network device through control.
  • the core network equipment can also send the initial MBS QFI SN through the data direction, that is, the MB-UPF network element can send the initial MBS QFI SN through the data direction to the access network equipment.
  • the MB-UPF network element can send an empty data packet to the access network device.
  • the initial MBS QFI SN is carried in the header of the data packet.
  • an empty data packet refers to a data packet that only includes a data packet header and does not include data (or bearer or payload).
  • the access network device can configure the MRB based on the initial MBS QFI SN carried in the packet header.
  • the core network is not aware of whether the data plane transmission channel is successfully established.
  • the MB-SMF network element needs to send the NG-U address to the access network device so that the access network device can join the IP multicast group. After the access device successfully receives the NG-U address and joins the IP multicast group, the data plane transmission channel is successfully established.
  • MB-SMF network elements and MB-UPF network elements cannot detect whether the access network device receives the NG-U address and when it successfully receives the NG-U address and successfully joins the IP multicast group.
  • the access network device When the PTP NG-U tunnel mode is used on the data plane, the access network device sends the NG-U address to the MB-SMF network element to request the establishment of an NG-U tunnel.
  • the MB-SMF network element can reply to the NG-U tunnel establishment request to the access network device to establish the NG-U tunnel.
  • the MB-SMF network element and the MB-UPF network element are also unable to sense when the access network device receives the MB-SMF reply, that is, they cannot sense whether the NG-U tunnel has been successfully established.
  • the timing of sending the above-mentioned empty data packet is particularly important. If the empty data packet is sent earlier, the access network device may not be able to receive the empty data packet because the data plane transmission channel is not successfully established. If the empty data packet is sent later, the MRB configuration delay will be larger.
  • this application provides the following three methods of sending empty data packets to improve the success rate of receiving empty data packets by the access network equipment and reduce the MRB configuration delay.
  • Method 1 The MB-UPF network element sends empty data packets to the access network device based on a timer.
  • MB-UPF can start the timer. After the timer times out, it sends an empty data packet to the access network device. The header of this empty data packet carries the initial MBS QFI SN.
  • the MB-UPF network element determines that it needs to send an initial MBS QFI SN to the access network device, which may include but is not limited to, when the MB-UPF network element receives a service establishment request or tunnel establishment request or PFCP session from the access network device. Create request.
  • the timer length can be preset by the MB-UPF network element; or it can be reported by the access network device; or it can be indicated by the MB-SMF network element to the MB-UPF network element; or it can be The administrator configures it through the operations, administration and maintenance (OAM) platform; or it can be defined by the protocol, which is not specifically limited in this application.
  • OAM operations, administration and maintenance
  • the appropriate timer length can be selected to ensure that the MB-UPF network element sends empty data packets to the access network device at the appropriate time, thereby improving the success rate of the access network device receiving empty data packets.
  • Method 2 The MB-UPF network element continuously sends N empty data packets.
  • N is a positive integer greater than 1.
  • the MB-UPF network element when the MB-UPF network element determines that it needs to send the initial MBS QFI SN to the access network device, the MB-UPF network element can continuously send N empty data packets, and the initial MBS QFI is carried in the header of the empty data packet. SN.
  • sequence numbers of the N empty data packets may be the same, or may be N consecutive sequence numbers, which is not specifically limited in this application.
  • the number N of empty data packets sent continuously can be preset by the MB-UPF network element; or it can be reported by the access network device; or it can be indicated by the MB-SMF network element to the MB-UPF network element. ; or it can be configured by the administrator through the OAM platform; or it can be defined by the protocol, which is not specifically limited in this application.
  • Method 3 The MB-UPF network element periodically sends empty data packets.
  • the MB-UPF network element when it determines that it needs to send the initial MBS QFI SN to the access network device, it can start to periodically send empty data packets to the access network device, and carry the initial MBS QFI in the header of the empty data packet. SN.
  • the sending cycle of empty data packets can be preset by the MB-UPF network element; or it can be instructed by the MB-SMF network element to the MB-UPF network element; or it can be configured by the administrator through the OAM platform; or It may be defined by a protocol, which is not specifically limited in this application.
  • the MB-UPF network element can repeatedly send empty data packets to the access network device, so that the access network device can receive the empty data packet as soon as possible after the data plane transmission channel is successfully established to obtain the initial MBS QFI SN , thereby improving the success rate of access network equipment receiving empty data packets and reducing the MRB configuration delay.
  • the MB-UPF network element supports sending the initial MBS QFI SN through the control plane (such as one or more processes shown in Figure 8 to Figure 18a) and the data plane (such as the process shown in Figure 22), then
  • the final decision of whether to send the initial MBS QFI SN via the control plane or the data plane can be decided by the MB-UPF network element.
  • the MB-SMF network element may decide to send the initial MBS QFI SN through the control plane (such as one or more processes shown in Figures 8 to 18a) or the data plane (such as the process shown in Figure 22).
  • the MB-SMF network element determines the sending method (control plane or data plane) of the initial MBS QFI SN, as a possible implementation, the MB-SMF network element can send indication information to the MB-UPF network element to explicitly Indicates how the initial MBS QFI SN is sent.
  • the indication information may be a 1-bit indication.
  • the 1-bit is set to "1 (or 0)"
  • it indicates that the initial MBS QFI SN is sent through the control plane
  • the 1-bit is set to "0 (or 1) )” indicates sending the initial MBS QFI SN through the data plane.
  • the indication information can be a Boolean parameter.
  • the Boolean parameter is set to "TRUE”, it indicates that the initial MBS QFI SN is sent through the control plane; when the Boolean parameter is set to "FALSE", it indicates that the initial MBS QFI SN is sent through the data plane.
  • Initial MBS QFI SN is a 1-bit indication.
  • the MB-UPF network element can default to the control plane (or Data plane) sends the initial MBS QFI SN.
  • the MB-UPF network element can send the initial MBS QFI SN through this sending method so that the access network device can perform MRB configuration.
  • the methods and/or steps implemented by the access network equipment can also be implemented by components (such as processors, chips, chip systems, circuits, and logic modules) that can be used in the access network equipment. , or software such as chips or circuits); the methods and/or steps implemented by the core network equipment can also be implemented by components (such as processors, chips, chip systems, circuits, logic modules, or software) that can be used in the core network equipment. Such as chip or circuit) implementation.
  • the above mainly introduces the solutions provided by this application.
  • this application also provides a communication device, which is used to implement Various methods mentioned above.
  • the communication device may be the access network equipment in the above method embodiment, or a device including the above access network equipment, or a component that can be used in the access network equipment, such as a chip or a chip system; or, the communication device may be
  • the core network equipment in the above method embodiment is either a device including the above core network equipment, or a component that can be used in the core network equipment, such as a chip or a chip system.
  • the communication device includes corresponding hardware structures and/or software modules for performing each function.
  • the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is performed by hardware or computer software driving the hardware depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each specific application, but such implementations should not be considered beyond the scope of this application.
  • Embodiments of the present application can divide the communication device into functional modules according to the above method embodiments.
  • functional modules can be divided into corresponding functional modules, or two or more functions can be integrated into one processing module.
  • the above integrated modules can be implemented in the form of hardware or 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. In actual implementation, there may be other division methods.
  • FIG. 19 shows a schematic structural diagram of the first core network device 190.
  • the first core network device 190 includes a processing module 1901 and a transceiver module 1902.
  • the first core network device 190 may also include a storage module (not shown in Figure 19) for storing program instructions and data.
  • the transceiver module 1902 which may also be called a transceiver unit, is used to implement sending and/or receiving functions.
  • the transceiver module 1902 may be composed of a transceiver circuit, a transceiver, a transceiver or a communication interface.
  • the transceiver module 1902 may include a receiving module and a sending module, respectively configured to perform the receiving and sending steps performed by the first core network device in the above method embodiment, and/or to support the steps described herein.
  • the processing module 1901 can be used to perform the steps of the processing class (such as determination, generation, acquisition, etc.) performed by the first core network device in the above method embodiment, and/or to support the steps described in this article. Other processes for the described technology.
  • the processing module 1901 is used to obtain the initial MBS QFI SN corresponding to the first MBS session.
  • the initial MBS QFI SN corresponding to the first MBS session is used to determine the initial superframe number HFN and reference SN; the transceiver module 1902 is used in the first process
  • the initial MBS QFI SN corresponding to the first MBS session is sent to the network device.
  • the first process is the process before sending the first data packet of the first MBS session to the access network device.
  • the initial MBS QFI SN corresponding to the first MBS session includes: the initial MBS QFI SN of the first MBS session, and/or the initial MBS QFI SN of at least one QoS flow of the first MBS session.
  • the initial MBS QFI SN corresponding to the first MBS session is less than or equal to the first MBS QFI SN, or the first MBS QFI SN minus the initial MBS QFI SN corresponding to the first MBS session is less than or equal to the first value.
  • the first MBS QFI SN is the default MBS QFI SN of the first data packet; the first value is a non-negative integer less than or equal to the packet data convergence protocol PDCP window size.
  • the transceiver module 1902 is also used to send the first data packet of the first MBS session to the access network device.
  • the initial MBS QFI SN corresponding to the first MBS session is less than or equal to the MBS QFI of the first data packet.
  • SN, or the MBS QFI SN of the first data packet minus the initial MBS QFI SN corresponding to the first MBS session is less than or equal to the first value.
  • the first process is a shared transmission channel establishment process.
  • the shared transmission channel establishment process is used to establish a shared transmission channel for the first MBS session.
  • the shared transmission channel is used for data transmission between the core network and the access network.
  • the transceiver module 1902 is used to send the initial MBS QFI SN corresponding to the first MBS session to the network device, including: the transceiver module 1902 is used to send the first message to the network device, the first message includes the first MBS session corresponding The initial MBS QFI SN, the first message is used to carry the address information of the shared transmission channel, and/or, the status information of the first MBS session.
  • the first process is a PDU session establishment process or a PDU session modification process.
  • the PDU session establishment process is used to establish or modify the first MBS session.
  • the PDU session modification process is used to establish or modify the first MBS session.
  • the first process is an MBS session update process
  • the MBS session update process is used to add a QoS flow in the first MBS session.
  • the first process is a multicast session activation process, and the multicast session activation process is used to activate the first MBS session.
  • the transceiver module 1902 is used to send the initial MBS QFI SN corresponding to the first MBS session to the network device, including: the transceiver module 1902 is used to send a second message, and the second message includes the initial MBS corresponding to the first MBS session. QFI SN, the second message is used to carry the identity of the first MBS session.
  • the transceiver module 1902 is also used to send first information to the network device.
  • the first information indicates whether the MBS QFI SN corresponding to the first MBS session is continuous or not when the first MBS session is activated after deactivating the first MBS session. Reset.
  • the transceiver module 1902 is used to send the first information to the network device, including: the transceiver module 1902 is used to send the first information to the network device.
  • the third message includes the first information.
  • the third message is used to request the establishment or modification of the first MBS session; or the third message is used to deactivate the first MBS session; or the third message is used to activate the first MBS session; or the third message is used to The first MBS session is updated; or, the third message is used to establish a shared transmission channel of the first MBS session.
  • the processing module 1901 is used to obtain the initial MBS QFI SN corresponding to the first MBS session, including: the processing module 1901 is used to receive the initial MBS corresponding to the first MBS session from the second core network device through the transceiver module 1902. QFISN.
  • the transceiver module 1902 is also used to send second information to the second core network device, and the second information is used to request the initial MBS QFI SN corresponding to the first MBS session.
  • the transceiving module 1902 is also configured to send a fourth message to the second core network device, where the fourth message is used to request the establishment or modification of a Packet Forwarding Control Protocol PFCP session.
  • the transceiver module 1902 is also used to receive the initial MBS QFI SN corresponding to the first MBS session from the second core network device, including: the transceiver module 1902 is also used to receive the fifth message from the second core network device, the fifth message Including the initial MBS QFI SN corresponding to the first MBS session, the fifth message is the response message of the fourth message.
  • the processing module 1901 is used to obtain the initial MBS QFI SN corresponding to the first MBS session, including: the processing module 1901 is used to receive the first MBS QFI SN from the second core network device through the transceiver module 1902.
  • the MBS QFI SN is the default MBS QFI SN of the first data packet; the processing module 1901 is also used to determine the initial MBS QFI SN corresponding to the first MBS session based on the first MBS QFI SN.
  • the transceiver module 1902 is also used to send the initial MBS QFI SN or the first MBS QFI SN corresponding to the first MBS session to the second core network device.
  • the first MBS QFI SN is the default MBS of the first data packet. QFISN.
  • the transceiver module 1902 is also used to send the initial MBS QFI SN corresponding to the first MBS session or the first MBS QFI SN to the second core network device, including: optionally, the transceiver module 1902 is also used to send the first MBS QFI SN to the second core network device.
  • the second core network device sends a fourth message.
  • the fourth message is used to request the establishment or modification of the PFCP session.
  • the fourth message includes the initial MBS QFI SN or the first MBS QFI SN corresponding to the first MBS session.
  • the transceiver module 1902 is also configured to receive a fifth message from the second core network device, where the fifth message is a response message to the fourth message; when the fifth message indicates that the PFCP session is established or modified successfully, it instructs the second core network device to accept the third message.
  • the processing module 1901 is used to determine the initial MBS QFI SN corresponding to the first MBS session, including: the processing module 1901 is used to receive the second information from the second core network device through the transceiver module 1902, and the second information is For requesting the initial MBS QFI SN corresponding to the first MBS session; the processing module 1901 is also used to determine the initial MBS QFI SN corresponding to the first MBS session based on the second information.
  • the processing module 1901 is used to determine the initial MBS QFI SN corresponding to the first MBS session, including: the processing module 1901 is used to receive the fourth message from the second core network device through the transceiver module 1902. The fourth message is For requesting to establish or modify a PFCP session; the processing module 1901 is also used for the first core network device to determine the initial MBS QFI SN corresponding to the first MBS session according to the fourth message.
  • the processing module 1901 is used to obtain the first information; the transceiving module 1902 is used to send the first information to the network device.
  • the first information indicates whether the MBS quality of service stream identifier QFI sequence number SN of the first MBS session is continuous or reset when the first MBS session is deactivated and then reactivated.
  • the transceiver module 1902 is configured to send the first information to the network device, including: the transceiver module 1902 is configured to send a third message to the network device, where the third message includes the first information.
  • the third message is used to request the establishment or modification of the first MBS session; or the third message is used to deactivate the first MBS session; or the third message is used to activate the first MBS session; or the third message is used to The first MBS session is updated; or, the third message is used to establish a shared transmission channel of the first MBS session.
  • the transceiving module 1902 is also used to send the initial MBS QFI SN of the first MBS session to the network device in the first process.
  • the initial MBS QFI SN corresponding to the first MBS session is used to determine the initial superframe number HFN and reference SN.
  • the first process is the process before sending the first data packet of the first MBS session to the access network device.
  • the first core network device 190 is presented in the form of dividing various functional modules in an integrated manner.
  • a “module” here may refer to an application-specific integrated circuit (ASIC), a circuit, a processor and memory that executes one or more software or firmware programs, an integrated logic circuit, and/or others that may provide the above functions. device.
  • ASIC application-specific integrated circuit
  • the first core network device 190 may take the form of the communication device 500 shown in FIG. 5 .
  • the function/implementation process of the processing module 1901 in Figure 19 can be implemented by the processor 501 in the communication device 500 shown in Figure 5 calling the computer execution instructions stored in the memory 503.
  • the function/implementation process of the transceiver module 1902 in Figure 19 can be This can be implemented through the communication interface 504 in the communication device 500 shown in FIG. 5 .
  • the function/implementation process of the transceiver module 1902 can be implemented through the input and output interface (or communication interface) of the chip or chip system, and the processing The function/implementation process of module 1901 can be implemented by a processor (or processing circuit) of a chip or chip system.
  • the first core network device 190 provided in this embodiment can perform the above method, the technical effects it can obtain can be referred to the above method embodiment, which will not be described again here.
  • FIG. 20 shows a schematic structural diagram of an access network device 200.
  • the access network device 200 includes a processing module 2001 and a transceiver module 2002.
  • the access network device 200 may also include a storage module (not shown in Figure 20) for storing program instructions and data.
  • the transceiver module 2002 which may also be called a transceiver unit, is used to implement sending and/or receiving functions.
  • the transceiver module 2002 may be composed of a transceiver circuit, a transceiver, a transceiver or a communication interface.
  • the transceiver module 2002 may include a receiving module and a transmitting module, respectively configured to perform the receiving and transmitting steps performed by the access network device in the above method embodiments, and/or to support the steps described herein.
  • the processing module 2001 can be used to perform steps of the processing class (such as determination, generation, etc.) performed by the access network device in the above method embodiments, and/or to support the technology described herein. Other processes.
  • the transceiver module 2002 is used to receive the initial MBS QFI SN corresponding to the first MBS session from the session management network element in the first process.
  • the first process is the process before receiving the first data packet of the first MBS session; the processing module 2001, used to determine the initial superframe number HFN and reference SN based on the initial MBS QFI SN corresponding to the first MBS session; the transceiver module 2002, also used to send the initial HFN and reference SN to the terminal device.
  • the first process is a shared transmission channel establishment process.
  • the shared transmission channel establishment process is used to establish a shared transmission channel for the first MBS session.
  • the shared transmission channel is used for data transmission between the core network and the access network.
  • the transceiver module 2002 is used to receive the initial MBS QFI SN corresponding to the first MBS session from the session management network element, including: the transceiver module 2002 is used to receive the first message from the session management network element.
  • the first message Including the initial MBS QFI SN corresponding to the first MBS session, the first message is used to carry the address information of the shared transmission channel, and/or the status information of the first MBS session.
  • the first process is a PDU session establishment process or a PDU session modification process.
  • the PDU session establishment process is used to establish or modify the first MBS session.
  • the PDU session modification process is used to establish or modify the first MBS session.
  • the first process is an MBS session update process
  • the MBS session update process is used to add a QoS flow in the first MBS session.
  • the first process is a multicast session activation process, and the multicast session activation process is used to activate the first MBS session.
  • the transceiver module 2002 is used to receive the initial MBS QFI SN corresponding to the first MBS session from the session management network element, including: the transceiver module 2002 is used to receive the second message from the session management network element.
  • the second message Including the initial MBS QFI SN corresponding to the first MBS session, the second message is used to carry the identity of the first MBS session.
  • the access network device 200 is presented in the form of dividing various functional modules in an integrated manner.
  • a “module” here may refer to an application-specific integrated circuit (ASIC), a circuit, a processor and memory that executes one or more software or firmware programs, an integrated logic circuit, and/or others that may provide the above functions. device.
  • ASIC application-specific integrated circuit
  • the access network device 200 may take the form of the communication device 500 shown in FIG. 5 .
  • the function/implementation process of the processing module 2001 in Figure 20 can be implemented by the processor 501 in the communication device 500 shown in Figure 5 calling the computer execution instructions stored in the memory 503.
  • the function/implementation process of the transceiver module 2002 in Figure 20 can be implemented through the communication interface 504 in the communication device 500 shown in Figure 5 .
  • the function/implementation process of the transceiver module 2002 can be implemented through the input and output interface (or communication interface) of the chip or chip system, and the processing module The function/implementation process of 2001 can be realized by the processor (or processing circuit) of the chip or chip system.
  • the access network device 200 provided in this embodiment can perform the above method, the technical effects it can obtain can be referred to the above method embodiment, which will not be described again here.
  • the access network equipment or core network equipment described in the embodiments of this application can also be implemented using the following: one or more field programmable gate arrays (field programmable gate arrays, FPGAs), programmable logic device device (PLD), controller, state machine, gate logic, discrete hardware components, any other suitable circuit, or any combination of circuits capable of performing the various functions described throughout this application.
  • field programmable gate arrays field programmable gate arrays, FPGAs
  • PLD programmable logic device device
  • controller state machine
  • gate logic discrete hardware components
  • discrete hardware components any other suitable circuit, or any combination of circuits capable of performing the various functions described throughout this application.
  • the access network equipment described in the embodiments of this application can be implemented by a general bus architecture.
  • Figure 21 is a schematic structural diagram of a communication device 2100 provided by an embodiment of the present application.
  • the communication device 2100 includes a processor 2101 and a transceiver 2102.
  • the communication device 2100 may be an access network device, or a chip or module thereof.
  • Figure 21 shows only the main components of the communication device 2100.
  • the communication device may further include a memory 2103.
  • the processor 2101 is mainly used to process communication protocols and communication data, control the entire communication device, execute software programs, and process data of the software programs.
  • Memory 2103 is mainly used to store software programs and data.
  • the transceiver 2102 may include a radio frequency circuit and an antenna.
  • the radio frequency circuit is mainly used for conversion of baseband signals and radio frequency signals and processing of radio frequency signals.
  • Antennas are mainly used to send and receive radio frequency signals in the form of electromagnetic waves.
  • the processor 2101, the transceiver 2102, and the memory 2103 can be connected through a communication bus.
  • the processor 2101 can read the software program in the memory 2103, interpret and execute the instructions of the software program, and process the data of the software program.
  • the processor 2101 performs baseband processing on the data to be sent, and then outputs the baseband signal to the radio frequency circuit.
  • the radio frequency circuit performs radio frequency processing on the baseband signal and then sends the radio frequency signal out in the form of electromagnetic waves through the antenna.
  • the radio frequency circuit receives the radio frequency signal through the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor 2101.
  • the processor 2101 converts the baseband signal into data and performs processing on the data. deal with.
  • the radio frequency circuit and antenna can be arranged independently of the processor that performs baseband processing.
  • the radio frequency circuit and antenna can be arranged remotely and independently of the communication device. .
  • embodiments of the present application further provide a communication device, which includes a processor and is configured to implement the method in any of the above method embodiments.
  • the communication device further includes a memory.
  • This memory is used to store necessary computer programs and data.
  • the computer program may include instructions, and the processor may call the instructions in the computer program stored in the memory to instruct the communication device to perform the method in any of the above method embodiments.
  • the memory may not be in the communication device.
  • the communication device further includes an interface circuit, which is a code/data reading and writing interface circuit.
  • the interface circuit is used to receive computer execution instructions (computer execution instructions are stored in the memory and may be directly read from memory, or possibly through other devices) and transferred to the processor.
  • the communication device further includes a communication interface, which is used to communicate with modules external to the communication device.
  • the communication device may be a chip or a chip system.
  • the communication device may be composed of a chip or may include a chip and other discrete devices. This is not specifically limited in the embodiments of the present application.
  • This application also provides a computer-readable storage medium on which a computer program or instructions are stored. When the computer program or instructions are executed by a computer, the functions of any of the above method embodiments are implemented.
  • This application also provides a computer program product, which implements the functions of any of the above method embodiments when executed by a computer.
  • the systems, devices and methods described in this application can also be implemented in other ways.
  • the device embodiments described above are only illustrative.
  • the division of the units is only a logical function division. In actual implementation, there may be other division methods.
  • multiple units or components may be combined or can be integrated into another system, or some features can be ignored, or not implemented.
  • the coupling or direct coupling or communication connection between each other shown or discussed may be through some interfaces, and the indirect coupling or communication connection of the devices or units may be in electrical, mechanical or other forms.
  • the units described as separate components may or may not be physically separate, that is, they may be located in one place, or they may be distributed to multiple network units. Components shown as units may or may not be physical units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.
  • each functional unit in each embodiment of the present application can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit.
  • the above embodiments it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof.
  • a software program 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 make.
  • computer program instructions When computer program instructions are loaded and executed on a computer, all or part of the processes (or functions) described in the embodiments of this application are implemented.
  • the computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device.
  • 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 transferred from a website, computer, server, or data center Transmission to another website, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) means.
  • the computer-readable storage medium can be any available medium that can be accessed by a computer or include one or more data storage devices such as servers and data centers that can be integrated with the medium.
  • the available media may be magnetic media (eg, floppy disk, hard disk, magnetic tape), optical media (eg, DVD), or semiconductor media (eg, solid state disk (SSD)), etc.
  • the computer may include the aforementioned device.

Abstract

一种通信方法及装置，使得接入网设备在未收到来自核心网设备的数据包的情况下，能够及时为终端设备配置初始HFN和参考SN。该方法包括：第一核心网设备获取第一MBS会话对应的初始MBS QFI SN，并在第一流程中发送该初始MBS QFI SN。其中，第一流程为多播广播用户面网元向接入网设备发送第一MBS会话的第一个数据包之前的流程。接入网设备在该第一流程中收到该初始MBS QFI SN后，可以根据该初始MBS QFI SN确定初始HFN和参考SN，并向终端设备发送该初始HFN和参考SN。

Description

一种通信方法及装置
本申请要求于2022年07月05日提交国家知识产权局、申请号为202210785100.4、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，以及要求于2022年09月23日提交国家知识产权局、申请号为202211167576.8、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领域，尤其涉及一种通信方法及装置。
背景技术
如图1所示，分组数据汇聚协议(packet data convergence protocol，PDCP)层的协议数据单元(protocol data unit，PDU)数据(DATA)标识(也称为COUNT值)由高位的超帧号(hyper frame number，HFN)和低位的PDCP序列号(sequence number，SN)组成。通常，发送端向接收端发送的PDCP PDU包括PDCP SN，HFN由接收端推算。
对于某一多播广播业务(multicast and broadcast service，MBS)，为了使不同的接入网设备针对该业务的同一数据包生成相同的COUNT值，核心网设备为服务质量(quality of service，QoS)流(flow)的每个数据包生成MBS QoS流标识(QoS flow identifier，QFI)SN，以便不同的接入网设备根据该MBS QFI SN生成COUNT值。
此外，为了使终端设备和接入网设备之间的COUNT值同步，在配置MBS无线承载(radio bear，MRB)时，接入网设备需要向终端设备指示该MRB对应的初始COUNT值，以便终端设备根据该初始COUNT值确定PDCP窗口的状态变量或后续收到的数据包的COUNT值。
然而，接入网设备在配置MRB时，可能还未收到来自核心网设备的数据包。此时，接入网设备如何指示初始COUNT值为亟待解决的问题。
发明内容
本申请提供一种通信方法及装置，使得接入网设备在未收到来自核心网设备的数据包的情况下，能够及时为终端设备配置初始HFN和参考SN。
第一方面，提供了一种通信方法，该方法可以由第一核心网设备执行，也可以由第一核心网设备的部件，例如第一核心网设备的处理器、芯片、或芯片系统等执行，还可以由能实现全部或部分第一核心网设备功能的逻辑模块或软件实现。该方法包括：第一核心网设备获取第一多播广播业务MBS会话对应的初始MBS QFI SN，并在第一流程中向网络设备发送第一MBS会话对应的初始MBS QFI SN。其中，第一MBS会话对应的初始MBS QFI SN用于确定初始超帧号HFN和参考SN。第一流程为向接入网设备发送第一MBS会话的第一个数据包之前的流程。
基于该方案，核心网设备可以在多播广播用户面网元向接入网设备发送第一MBS会话的第一个数据包之前，发送第一MBS会话对应的初始MBS QFI SN，使得接入网设备能够根据该初始MBS QFI SN确定初始HFN和参考SN，从而向终端设备配置该初始HFN和参考SN，进而使得接入网设备无需等待数据包到达即可及时为终端设备配置MRB，指示初始HFN和参考SN。此外，由于该初始MBS QFI SN为核心网侧提供的参数，因此核心网侧最终可能使用该初始MBS QFI SN作为该第一个数据包的MBS QFI SN，或者根据该初始MBS QFI SN确定该第一个数据包的MBS QFI SN，从而可以提高接入网设备在收到数据包之前配置的初始HFN和参考SN的准确性。
在一种可能的设计中，第一MBS会话对应的初始MBS QFI SN包括：第一MBS会话的初始MBS QFI SN，和/或，第一MBS会话的至少一个QoS流的初始MBS QFI SN。
基于该可能的设计，核心网侧能够实现以MBS会话为粒度，和/或，以QoS流为粒度配置初始MBS QFI SN。在以QoS流为粒度配置初始MBS QFI SN时可以为不同QoS流配置不同的MBS QFI SN，灵活性高。
在一种可能的设计中，第一MBS会话对应的初始MBS QFI SN小于或等于第一MBS QFI SN，或者，第一MBS QFI SN减第一MBS会话对应的初始MBS QFI SN小于或等于第一数值。其中，第一MBS QFI SN为第一MBS会话的第一个数据包的预设MBS QFI SN。第一数值为小于或等于PDCP窗口大小的非负整数。
基于该可能的设计，在第一数值为小于PDCP窗口大小的非负整数时，使得该第一MBS会话对应的初始MBS QFI SN和预设MBS QFI SN位于一个PDCP窗口大小内。
在一种可能的设计中，该方法还包括：第一核心网设备向接入网设备发送第一MBS会话的第一个数据包，第一MBS会话对应的初始MBS QFI SN小于或等于该第一个数据包的MBS QFI SN，或者，该第一个数据包的MBS QFI SN减第一MBS会话对应的初始MBS QFI SN小于或等于第一数值，第一数值为小于或等于PDCP窗口大小的非负整数。
基于该可能的设计，在第一数值为小于PDCP窗口大小的非负整数时，使得该第一个数据包的实际MBS QFI SN和第一MBS会话对应的初始MBS QFI SN位于一个PDCP窗口大小内。从而使得接入网设备确定的初始HFN和参考SN指示的初始COUNT值和第一数据包的实际MBS QFI SN位于一个PDCP窗口大小内，进而使得终端设备能够根据该初始COUNT值准确获取后续数据包的COUNT值。此外，允许第一个数据包的(实际)MBS QFI SN、预设MBS QFI SN、和第一MBS会话对应的初始MBS QFI SN在一定范围内不相等，可以提升灵活性。
在一种可能的设计中，第一流程为共享传输通道建立流程，该共享传输通道建立流程用于为第一MBS会话建立共享传输通道，该共享传输通道用于核心网和接入网之间的数据传输。
基于该可能的设计，核心网侧可以在共享传输通道建立流程中发送第一MBS会话对应的初始MBS QFI SN，从而降低由于MRB延迟配置而导致的业务时延，提高接入网设备在收到数据包之前配置的初始HFN和参考SN的准确性。此外，在共享传输通道建立流程被执行时，表示接入网设备触发了与核心网之间的共享传输通道建立，并且接入网设备需要配置MRB以向终端设备发送业务数据，在接入网设备通过该传输通道接收来自核心网的第一个数据包之前，接入网设备无法确定MRB配置中的初始HFN和参考SN。在共享传输通道建立流程中配置初始MBS QFI SN的情况下，由于接入网设备需要配置MRB，因此接入网设备将使用该初始MBS QFI SN确定初始HFN和参考SN，避免核心网配置了初始MBS QFI SN但接入网设备未使用的情况，从而避免通信资源浪费。
在一种可能的设计中，第一核心网设备向网络设备发送第一MBS会话对应的初始MBS QFI SN，包括：第一核心网设备向网络设备发送第一消息，该第一消息包括第一MBS会话对应的初始MBS QFI SN。该第一消息用于承载共享传输通道的地址信息，和/或，第一MBS会话的状态信息。
在一种可能的设计中，第一流程为PDU会话建立流程或PDU会话修改流程。该PDU会话建立流程用于建立或修改第一MBS会话，该PDU会话修改流程用于建立或修改第一MBS会话。
基于该可能的设计，核心网侧可以在PDU会话建立流程或PDU会话修改流程中发送第一MBS会话对应的初始MBS QFI SN，从而降低由于MRB延迟配置而导致的业务时延，提高接入网设备在收到数据包之前配置的初始HFN和参考SN的准确性。
在一种可能的设计中，第一流程为MBS会话更新流程。该MBS会话更新流程用于在第一MBS会话中添加QoS流。
基于该可能的设计，核心网侧可以在MBS会话更新流程中发送第一MBS会话对应的初始MBS QFI SN，在接入网设备需要配置MRB的情况下，降低由于MRB延迟配置而导致的业务时延，提高接入网设备在收到数据包之前配置的初始HFN和参考SN的准确性。
在一种可能的设计中，第一流程为组播会话激活流程。该组播会话激活流程用于激活第一MBS会话。
基于该可能的设计，核心网侧可以在组播会话激活流程中发送第一MBS会话对应的初始MBS QFI SN，在接入网设备需要配置MRB的情况下，降低由于MRB延迟配置而导致的业务时延，提高接入网设备在收到数据包之前配置的初始HFN和参考SN的准确性。
在一种可能的设计中，第一核心网设备向网络设备发送第一MBS会话对应的初始MBS QFI SN，包括：第一核心网设备向网络设备发送第二消息。该第二消息包括第一MBS会话对应的初始MBS QFI SN，第二消息用于承载第一MBS会话的标识。
在一种可能的设计中，该方法还包括：第一核心网设备向网络设备发送第一信息。该第一信息指示去激活第一MBS会话后再激活第一MBS会话时，第一MBS会话对应的MBS QFI SN是否连续或重置。
在一种可能的设计中，第一核心网设备向网络设备发送第一信息，包括：第一核心网设备向网络设备发送第三消息，该第三消息包括第一信息。其中：第三消息用于请求建立或修改第一MBS会话；或者，第三消息用于去激活第一MBS会话；或者，第三消息用于激活第一MBS会话；或者，第三消息用于更新第一MBS会话；或者，第三消息用于建立第一MBS会话的共享传输通道。
在一种可能的设计中，第一核心网设备获取第一MBS会话对应的初始MBS QFI SN，包括：第一核心 网设备接收来自第二核心网设备的第一MBS会话对应的初始MBS QFI SN。
在一种可能的设计中，该方法还包括：第一核心网设备向第二核心网设备发送第二信息，第二信息用于请求第一MBS会话对应的初始MBS QFI SN。
在一种可能的设计中，该方法还包括：第一核心网设备向第二核心网设备发送第四消息，该第四消息用于请求建立或修改包转发控制协议PFCP会话。第一核心网设备接收来自第二核心网设备的第一MBS会话对应的初始MBS QFI SN，包括：第一核心网设备接收来自第二核心网设备的第五消息，第五消息包括第一MBS会话对应的初始MBS QFI SN，第五消息为第四消息的响应消息。
在一种可能的设计中，第一核心网设备获取第一MBS会话对应的初始MBS QFI SN，包括：第一核心网设备接收来自第二核心网设备的第一MBS QFI SN，并根据第一MBS QFI SN确定第一MBS会话对应的初始MBS QFI SN。其中，该第一MBS QFI SN为第一个数据包的预设MBS QFI SN。
在一种可能的设计中，该方法还包括：第一核心网设备向第二核心网设备发送第一MBS会话对应的初始MBS QFI SN或第一MBS QFI SN，第一MBS QFI SN为第一个数据包的预设MBS QFI SN。
在一种可能的设计中，第一核心网设备向第二核心网设备发送第一MBS会话对应的初始MBS QFI SN或第一MBS QFI SN，包括：第一核心网设备向第二核心网设备发送第四消息，第四消息用于请求建立或修改PFCP会话，第四消息包括第一MBS会话对应的初始MBS QFI SN或第一MBS QFI SN。该方法还包括：第一核心网设备接收来自第二核心网设备的第五消息，第五消息为第四消息的响应消息；第五消息指示PFCP会话建立或修改成功时，指示第二核心网设备接受第一MBS会话对应的初始MBS QFI SN或第一MBS QFI SN。
在一种可能的设计中，第一核心网设备确定第一MBS会话对应的初始MBS QFI SN，包括：第一核心网设备接收来自第二核心网设备的第二信息，该第二信息用于请求第一MBS会话对应的初始MBS QFI SN；第一核心网设备根据第二信息，确定第一MBS会话对应的初始MBS QFI SN。
在一种可能的设计中，第一核心网设备确定第一MBS会话对应的初始MBS QFI SN，包括：第一核心网设备接收来自第二核心网设备的第四消息，第四消息用于请求建立或修改PFCP会话；第一核心网设备根据第四消息，确定第一MBS会话对应的初始MBS QFI SN。
第二方面，提供了一种通信方法，该方法可以由接入网设备执行，也可以由接入网设备的部件，例如接入网设备的处理器、芯片、或芯片系统等执行，还可以由能实现全部或部分接入网设备功能的逻辑模块或软件实现。该方法包括：接入网设备在第一流程中接收来自会话管理网元的第一多播广播业务MBS会话对应的初始MBS QFI SN，第一流程为接入网设备接收第一MBS会话的第一个数据包之前的流程。接入网设备根据第一MBS会话的初始MBS QFI SN确定初始超帧号HFN和参考SN，并向终端设备发送初始HFN和参考SN。
基于该方案，接入网设备可以在接收第一MBS会话的第一个数据包之前，接收来自核心网侧的第一MBS会话对应的初始MBS QFI SN，使得接入网设备能够根据该初始MBS QFI SN确定初始HFN和参考SN，从而向终端设备配置该初始HFN和参考SN，进而使得接入网设备无需等待数据包到达即可及时为终端设备配置MRB，指示初始HFN和参考SN。此外，由于初始MBS QFI SN为核心网侧提供的参数，因此核心网侧最终可能使用该初始MBS QFI SN作为该第一个数据包的MBS QFI SN，或者根据该初始MBS QFI SN确定该第一个数据包的MBS QFI SN，从而可以提高接入网设备在收到数据包之前配置的初始HFN和参考SN的准确性。
在一种可能的设计中，第一流程为共享传输通道建立流程，共享传输通道建立流程用于为第一MBS会话建立共享传输通道，共享传输通道用于核心网和接入网之间的数据传输。
在一种可能的设计中，接入网设备接收来自会话管理网元的第一MBS会话对应的初始MBS QFI SN，包括：接入网设备接收来自会话管理网元的第一消息，第一消息包括第一MBS会话对应的初始MBS QFI SN，第一消息用于承载共享传输通道的地址信息，和/或，第一MBS会话的状态信息。
在一种可能的设计中，第一流程为PDU会话建立流程或PDU会话修改流程，PDU会话建立流程用于建立或修改第一MBS会话，PDU会话修改流程用于建立或修改第一MBS会话。
在一种可能的设计中，第一流程为MBS会话更新流程，MBS会话更新流程用于在第一MBS会话中添加QoS流。
在一种可能的设计中，第一流程为组播会话激活流程，组播会话激活流程用于激活第一MBS会话。
在一种可能的设计中，接入网设备接收来自会话管理网元的第一MBS会话对应的初始MBS QFI SN，包括：接入网设备接收来自会话管理网元的第二消息，第二消息包括第一MBS会话对应的初始MBS QFI  SN，第二消息用于承载第一MBS会话的标识。
其中，第二方面中的任一可能的设计所带来的技术效果可参考上述第一方面中相应设计所带来的技术效果，在此不再赘述。
第三方面，提供了一种通信方法，该方法可以由第一核心网设备执行，也可以由第一核心网设备的部件，例如第一核心网设备的处理器、芯片、或芯片系统等执行，还可以由能实现全部或部分第一核心网设备功能的逻辑模块或软件实现。该方法包括：第一核心网设备获取第一信息，并向网络设备发送该第一信息。其中，第一信息指示去激活第一多播广播业务MBS会话后再激活第一MBS会话时，第一MBS会话的MBS服务质量流标识QFI序列号SN是否连续或重置。
基于该方案，若第一信息指示去激活第一MBS会话后再激活第一MBS会话时，第一MBS会话对应的MBS QFI SN不连续或被重置，可以使得接入网设备在收到第一MBS会话的去激活请求时，释放第一MBS会话的MRB，从而使得接入网设备可以尽早释放MRB。或者，可以使得接入网设备在收到第一MBS会话的激活请求时，释放第一MBS会话的MRB再新建MRB，使得接入网设备在MBS会话激活前即可建立MRB，相比于MBS会话激活后再建立MRB，可以降低业务时延。
在一种可能的设计中，第一核心网设备向网络设备发送第一信息，包括：第一核心网设备向网络设备发送第三消息，该第三消息包括第一信息。其中：第三消息用于请求建立或修改第一MBS会话；或者，第三消息用于去激活第一MBS会话；或者，第三消息用于激活第一MBS会话；或者，第三消息用于更新第一MBS会话；或者，第三消息用于建立第一MBS会话的共享传输通道。
在一种可能的设计中，该方法还包括：第一核心网设备在第一流程中向网络设备发送第一MBS会话的初始MBS QFI SN。其中，其中，第一MBS会话对应的初始MBS QFI SN用于确定初始超帧号HFN和参考SN。第一流程为向接入网设备发送第一MBS会话的第一个数据包之前的流程。
基于该可能的设计，可以使得接入网设备根据该第一MBS会话的初始MBS QFI SN为终端设备配置MRB，提高接入网设备配置的初始HFN和参考SN的准确性。
第四方面，提供了一种通信装置用于实现各种方法。该通信装置可以为第一方面或第三方面中的第一核心网设备，或者第一核心网设备中包含的装置，比如芯片或芯片系统或模块；或者，所述通信装置可以为第二方面中的接入网设备，或者接入网设备中包含的装置，比如芯片或芯片系统或模块。所述通信装置包括实现方法相应的模块、单元、或手段(means)，该模块、单元、或means可以通过硬件实现，软件实现，或者通过硬件执行相应的软件实现。该硬件或软件包括一个或多个与功能相对应的模块或单元。
在一些可能的设计中，该通信装置可以包括处理模块和收发模块。该处理模块，可以用于实现上述任一方面及其任意可能的实现方式中的处理功能。该收发模块，也可以称为收发单元，用以实现上述任一方面及其任意可能的实现方式中的发送和/或接收功能。该收发模块可以由收发电路，收发机，收发器或者通信接口构成。
在一些可能的设计中，收发模块包括发送模块和/或接收模块，分别用于实现上述任一方面及其任意可能的实现方式中的发送或接收功能。
第五方面，提供一种通信装置，包括：处理器和通信接口；该通信接口，用于与该通信装置之外的模块通信；所述处理器用于执行计算机程序或指令，以使该通信装置执行任一方面所述的方法。该通信装置可以为第一方面或第三方面中的第一核心网设备，或者第一核心网设备中包含的装置，比如芯片或芯片系统或模块；或者，所述通信装置可以为第二方面中的接入网设备，或者接入网设备中包含的装置，比如芯片或芯片系统或模块。
第六方面，提供了一种通信装置，包括：至少一个处理器；所述处理器用于执行存储器中存储的计算机程序或指令，以使该通信装置执行任一方面所述的方法。该存储器可以与处理器耦合，或者，该存储器也可以独立于处理器存在，例如，存储器和处理器为两个独立的模块。该存储器可以位于所述通信装置之外，也可以位于所述通信装置之内。该通信装置可以为第一方面或第三方面中的第一核心网设备，或者第一核心网设备中包含的装置，比如芯片或芯片系统或模块；或者，所述通信装置可以为第二方面中的接入网设备，或者接入网设备中包含的装置，比如芯片或芯片系统或模块。该装置是芯片系统时，可以由芯片构成，也可以包含芯片和其他分立器件。
第七方面，提供了一种计算机可读存储介质，该计算机可读存储介质中存储有计算机程序或指令，当其在通信装置上运行时，使得通信装置可以执行任一方面所述的方法。
第八方面，提供了一种包含指令的计算机程序产品，当其在通信装置上运行时，使得该通信装置可以执行任一方面所述的方法。
可以理解的是，第四方面至第八方面中任一方面提供的通信装置是芯片时，发送动作/功能可以理解为输出信息，接收动作/功能可以理解为输入信息。
其中，第四方面至第八方面中任一种设计方式所带来的技术效果可参见第一方面或第二方面或第三方面中不同设计方式所带来的技术效果，在此不再赘述。
附图说明
图1为本申请提供的一种COUNT的结构示意图；
图2为本申请提供的一种通信系统的结构示意图；
图3为本申请提供的另一种通信系统的结构示意图；
图4为本申请提供的又一种通信系统的结构示意图；
图5为本申请提供的一种通信装置的结构示意图；
图6为本申请提供的一种MBS的传输路径示意图；
图7为本申请提供的一种用户面协议栈的结构示意图；
图8为本申请提供的一种组播会话建立流程的示意图；
图9为本申请提供的一种MBS会话去激活流程的示意图；
图10为本申请提供的一种MBS会话激活流程的示意图；
图11为本申请提供的一种通信方法的流程示意图；
图12为本申请提供的另一种通信方法的流程示意图；
图13为本申请提供的又一种通信方法的流程示意图；
图14为本申请提供的一种通信方法的应用流程示意图一；
图15为本申请提供的一种通信方法的应用流程示意图二；
图16为本申请提供的一种通信方法的应用流程示意图三；
图17为本申请提供的一种通信方法的应用流程示意图四；
图18a为本申请提供的再一种通信方法的流程示意图；
图18b为本申请提供的再一种通信方法的流程示意图；
图19为本申请提供的一种第一核心网设备的结构示意图；
图20为本申请提供的一种接入网设备的结构示意图；
图21为本申请提供的另一种通信装置的结构示意图；
图22为本申请提供的再一种通信方法的流程示意图。
具体实施方式
在本申请的描述中，除非另有说明，“/”表示前后关联的对象是一种“或”的关系，例如，A/B可以表示A或B；本申请中的“和/或”仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况，其中A，B可以是单数或者复数。
在本申请的描述中，除非另有说明，“多个”是指两个或多于两个。“以下至少一项(个)”或其类似表达，是指的这些项中的任意组合，包括单项(个)或复数项(个)的任意组合。例如，a，b，或c中的至少一项(个)，可以表示：a，b，c，a-b，a-c，b-c，或a-b-c，其中a，b，c可以是单个，也可以是多个。
另外，为了便于清楚描述本申请实施例的技术方案，在本申请的实施例中，采用了“第一”、“第二”等字样对功能和作用基本相同的相同项或相似项进行区分。本领域技术人员可以理解“第一”、“第二”等字样并不对数量和执行次序进行限定，并且“第一”、“第二”等字样也并不限定一定不同。
在本申请实施例中，“示例性的”或者“例如”等词用于表示作例子、例证或说明。本申请实施例中被描述为“示例性的”或者“例如”的任何实施例或设计方案不应被解释为比其它实施例或设计方案更优选或更具优势。确切而言，使用“示例性的”或者“例如”等词旨在以具体方式呈现相关概念，便于理解。
可以理解，说明书通篇中提到的“实施例”意味着与实施例有关的特定特征、结构或特性包括在本申请的至少一个实施例中。因此，在整个说明书各个实施例未必指相同的实施例。此外，这些特定的特征、结构或特性可以任意适合的方式结合在一个或多个实施例中。可以理解，在本申请的各种实施例中，各过程的序号的大小并不意味着执行顺序的先后，各过程的执行顺序应以其功能和内在逻辑确定，而不应对本申请实施例的实施过程构成任何限定。
可以理解，在本申请中，“…时”以及“若”均指在某种客观情况下会做出相应的处理，并非是限定时间，且也不要求实现时要有判断的动作，也不意味着存在其它限定。
可以理解，本申请实施例中的一些可选的特征，在某些场景下，可以不依赖于其他特征，比如其当前所基于的方案，而独立实施，解决相应的技术问题，达到相应的效果，也可以在某些场景下，依据需求与其他特征进行结合。相应的，本申请实施例中给出的装置也可以相应的实现这些特征或功能，在此不予赘述。
本申请中，除特殊说明外，各个实施例之间相同或相似的部分可以互相参考。在本申请中各个实施例如果没有特殊说明以及逻辑冲突，不同的实施例之间的术语和/或描述具有一致性、且可以相互引用，不同的实施例根据其内在的逻辑关系可以组合形成新的实施例。以下所述的本申请实施方式并不构成对本申请保护范围的限定。
本申请提供的技术方案可用于各种通信系统，该通信系统可以为第三代合作伙伴计划(3rd generation partnership project，3GPP)通信系统，例如，第四代(4th generation，4G)长期演进(long term evolution，LTE)系统、第五代(5th generation，5G)新无线(new radio，NR)系统、车联网(vehicle to everything，V2X)系统、LTE和NR混合组网的系统、或者设备到设备(device-to-device，D2D)系统、机器到机器(machine to machine，M2M)通信系统、物联网(Internet of Things，IoT)，以及其他下一代通信系统等。或者，该通信系统也可以为非3GPP通信系统，不予限制。
其中，上述适用本申请的通信系统仅是举例说明，适用本申请的通信系统不限于此，在此统一说明，以下不再赘述。
参见图2，为本申请提供的一种示例性的通信系统。该通信系统包括接入网设备和至少一个终端设备。进一步的，该通信系统还可以包括核心网设备。
可选的，如图3所示，核心网设备可以包括移动管理网元、会话管理网元、多播广播会话管理网元、或多播广播用户面网元中的至少一项。
可选的，终端设备可以通过从终端设备到接入网设备到核心网设备到数据网络(data network，DN)的协议数据单元(protocol data unit，PDU)会话(PDU session)，来访问DN，或者进行业务数据传输。
可选的，终端设备可以指一种具有无线收发功能的用户侧设备。终端设备也可以称为用户设备(user equipment，UE)、终端等。示例性的，终端设备可以是无人机、IoT设备(例如，传感器，电表，水表等)、V2X设备、无线局域网(wireless local area networks，WLAN)中的站点(station，ST)、个人数字处理(personal digital assistant，PDA)设备、具有无线通信功能的手持设备、计算设备或连接到无线调制解调器的其它处理设备、车载设备、可穿戴设备(也可以称为穿戴式智能设备)、平板电脑或带无线收发功能的电脑；或者，可以是虚拟现实(virtual reality，VR)终端、工业控制(industrial control)、无人驾驶(self driving)、远程医疗(remote medical)、智能电网(smart grid)、运输安全(transportation safety)、智慧城市(smart city)、智慧家庭(smart home)中的无线终端；或者，可以是车载终端、具有车对车(vehicle-to-vehicle，V2V)通信能力的车辆、智能网联车、具有无人机对无人机(UAV to UAV，U2U)通信能力的无人机等等。
可选的，接入网设备是一种具有无线收发功能的网络侧设备，可以是LTE或演进的LTE系统(LTE-Advanced，LTE-A)中的演进型基站(evolutional Node B，eNB或eNodeB)，如传统的宏基站eNB和异构网络场景下的微基站eNB；或者可以是5G系统中的下一代节点B(next generation node B，gNodeB或gNB)；或者可以是传输接收点(transmission reception point，TRP)；或者可以是未来演进的公共陆地移动网络(public land mobile network，PLMN)中的基站；或者可以是宽带网络业务网关(broadband network gateway，BNG)、汇聚交换机或非3GPP接入设备；或者可以是云无线接入网络(cloud radio access network，CRAN)中的无线控制器；或者可以是WiFi系统中的接入节点(access point，AP)；或者可以是无线中继节点或无线回传节点；或者可以是IoT、V2X、D2D、M2M中实现基站功能的设备。
可选的，在具体实现时，接入网设备可以指集中单元(central unit，CU)，或者，接入网设备可以是CU和分布式单元(distributed unit，DU)组成的。CU和DU可以根据无线网络的协议层划分。例如，无线资源控制(radio resource control，RRC)协议层、业务数据适配协议(service data adaptation protocol,SDAP)层以及分组数据汇聚协议(packet data convergence protocol，PDCP)层的功能设置在CU中，而无线链路控制(radio link control，RLC)层，媒体接入控制(media access control，MAC)层，物理(physical，PHY)层的功能设置在DU中。
可以理解，对CU和DU处理功能按照这种协议层的划分仅仅是一种举例，也可以按照其他的方式进行划分，本申请对此不作具体限定。
在一些实施例中，CU可以由CU控制面(CU control plane，CU-CP)和CU用户面(CU user plane，CU-UP)组成。
可选的，移动管理网元主要用于移动网络中的终端设备的附着、移动性管理、跟踪区更新流程等。移动管理网元终结了非接入层(non access stratum，NAS)消息、完成注册管理、连接管理以及可达性管理、分配跟踪区域列表(track area list，TA list)以及移动性管理等，并且透明路由会话管理(session management，SM)消息到会话管理网元。在5G通信系统中，移动管理网元可以是接入和移动管理功能(access and mobility management function，AMF)网元。在未来通信如第六代(6th generation，6G)通信中，移动管理网元仍可以是AMF网元，或者有其它名称，本申请实施例对此不作限定。
可选的，会话管理网元主要负责移动网络中的会话管理，如管理会话的建立、修改、释放等。在5G通信系统中，会话管理网元可以是会话管理功能(session management function，SMF)网元。在未来通信(如6G通信)中，会话管理网元仍可以是SMF网元，或者有其它名称，本申请实施例对此不作限定。
可选的，多播广播会话管理网元主要负责移动网络中多播广播业务(multicast and broadcast service，MBS)的会话管理。在5G通信系统中，多播广播会话管理网元可以是多播广播(multicast and broadcast，MB)SMF网元，即MB-SMF网元。在未来通信如6G通信中，多播广播会话管理网元仍可以是MB-SMF网元，或者有其它名称，本申请实施例对此不作限定。
可选的，本申请中的会话管理网元也可以参与MBS的会话管理等与MBS相关的流程。
可选的，多播广播用户面网元主要负责对MBS的报文进行处理，如转发、计费等。在5G通信系统中，多播广播用户面网元可以是MB用户面功能(user plane function，UPF)网元，即MB-UPF网元。在未来通信(如6G通信)中，多播广播用户面网元仍可以是MB-UPF网元，或者有其它名称，本申请实施例对此不作限定。
可选的，本申请中多播广播用户面网元的功能也可以由用户面网元实现，即本申请中的多播广播用户面网元可以替换为用户面网元。
以5G通信系统为例，本申请实施例使用的一种可能的与图3所示通信系统对应的网络架构可以如图4所示。
需要说明的是，本申请实施例描述的通信系统以及业务场景是为了更加清楚的说明本申请实施例的技术方案，并不构成对于本申请实施例提供的技术方案的限定，本领域普通技术人员可知，随着网络架构的演变和新业务场景的出现，本申请实施例提供的技术方案对于类似的技术问题，同样适用。
本申请涉及的终端设备、接入网设备、核心网设备的相关功能可以由一个设备实现，也可以由多个设备共同实现，还可以是由一个设备内的一个或多个功能模块实现，或者可以为一个或多个芯片，也可以为片上系统(system on chip，SOC)或芯片系统，芯片系统可以由芯片构成，也可以包括芯片和其他分立器件，本申请实施例对此不作具体限定。
可以理解的是，上述功能既可以是硬件设备中的网络元件，也可以是在专用硬件上运行的软件功能，或者是硬件与软件的结合，或者是平台(例如，云平台)上实例化的虚拟化功能。
例如，本申请涉及的终端设备、接入网设备、核心网设备可以通过图5中的通信设备500来实现。图5为本申请提供的一种通信装置500的组成示意图，该通信装置500可以为终端设备或者终端设备中的芯片或者片上系统；或者，可以为接入网设备或者接入网设备中的模块或芯片或片上系统；或者，可以为核心网设备或者核心网设备中的模块或芯片或片上系统。
如图5所示，该通信装置500包括至少一个处理器501，以及至少一个通信接口(图5中仅是示例性的以包括一个通信接口504，以及一个处理器501为例进行说明)。可选的，该通信装置500还可以包括通信总线502和存储器503。
处理器501可以是一个通用中央处理器(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501还可以是其它具有处理功能的装置，例如电路、器件或软件模块，不予限制。
通信总线502用于连接通信装置500中的不同组件，使得不同组件可以通信。通信总线502可以是外设部件互连标准(peripheral component interconnect，PCI)总线或扩展工业标准结构(extended industry standard architecture，EISA)总线等。该总线可以分为地址总线、数据总线、控制总线等。为便于表示，图5中仅用一条粗线表示，但并不表示仅有一根总线或一种类型的总线。
通信接口504，用于与其他设备或通信网络通信。示例性的，通信接口504可以模块、电路、收发器 或者任何能够实现通信的装置。可选的，所述通信接口504也可以是位于处理器501内的输入输出接口，用以实现处理器的信号输入和信号输出。
存储器503，可以是具有存储功能的装置，用于存储指令和/或数据。其中，指令可以是计算机程序。
示例性的，存储器503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、蓝光光碟等)、磁盘存储介质或其他磁存储设备等，不予限制。
需要指出的是，存储器503可以独立于处理器501存在，也可以和处理器501集成在一起。存储器503可以位于通信装置500内，也可以位于通信装置500外，不予限制。处理器501，可以用于执行存储器503中存储的指令，以实现本申请下述实施例提供的方法。
作为一种可选的实现方式，通信装置500还可以包括输出设备和输入设备(图5中未示出)。输出设备和处理器501通信，可以以多种方式来显示信息。输入设备和处理器501通信，可以以多种方式接收用户的输入。
需要说明的是，图5所示的结构并不构成对接入网设备、核心网设备、或终端设备的具体限定。比如，在本申请另一些实施例中，接入网设备、核心网设备、或终端设备可以包括比图示更多或更少的部件，或者组合某些部件，或者拆分某些部件，或者不同的部件布置。图示的部件可以以硬件，软件或软件和硬件的组合实现。
为了方便理解本申请实施例的技术方案，首先给出本申请相关技术的简要介绍如下。
1、多播广播业务MBS：
MBS是面向多个终端设备的业务，常见的MBS包括直播业务、公共安全业务、批量软件更新业务等。从端到端的管理控制流程以及传输方式，MBS可以划分为组播(multicast)业务和广播(broadcast)业务。
需要说明的是，本申请仅是示例性的将可以划分为组播业务和广播业务的业务统称为MBS，本申请对MBS的名称不作具体限定，随着无线通信技术的演变，MBS也可以有其他名称。
组播业务的服务质量(quality of service，QoS)要求通常较高，组播业务可以达到和单播业务相同的QoS等级。通常，可以对组播业务进行组管理等操作。示例性的，核心网设备可以管理终端设备加入或退出组播业务组，接入网设备和核心网设备可以维护组播业务组中终端设备的信息。
如图6所示，MBS服务器可以将MBS的数据发送给核心网设备。在核心网设备和接入网设备之间，组播业务通过MBS会话传输，MBS会话包括MBS QoS流(或称为多播QoS流(multi-cast QoS flow))。MBS会话可以关联终端设备的PDU会话，MBS QoS流关联PDU会话中的单播QoS流。核心网设备可以控制MBS会话的状态为激活状态或去激活状态，终端设备并不感知MBS会话的状态。
接入网设备向终端设备发送组播业务时，可以采用点到多点(point to multi-point，PTM)或点到点(point to point，PTP)的传输方式。
需要说明的是，本申请中的MBS会话也可以称为多播(multicast)会话，二者可以相互替换。此外，MBS会话可以和MBS一一对应，某个MBS及其对应的MBS会话可以使用同一标识来表示，例如，MBS和MBS会话均可以使用临时多播组标识(temporary multicast group identifier，TMGI)标识。因此，本申请中的MBS会话和MBS也可以相互替换。
2、无线接入网侧协议栈：
无线接入网侧的协议栈可以分为用户面协议栈和控制面协议栈。用户面协议栈可以包括业务数据适配协议(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)层和物理(physical，PHY)层等。其中，物理层属于第一层(也称为层一(layer 1，L1))，MAC层、RLC层、PDCP层、以及SDAP层属于第二层(也称为层二(layer 2，L2))。此外，控制面的无线资源控制(radio resource control，RRC)层属于第三层(也称为层三(layer 3，L3))。
如图7所示，MBS的用户面协议栈中，SDAP层位于PDCP层之上，PDCP层位于RLC层之上，RLC层位于MAC层之上，MAC层位于物理层之上。对于MBS，数据到达接入网设备后，各个协议层按照图7所示的由上到下的顺序依次对数据包进行处理，最终通过空口向终端设备传输。终端设备在空口接收到数据包后，按照与接入网设备相反的顺序依次对数据包进行相应的处理。其中，各个协议层对数据包的处 理由该协议层对应的多功能实体实现，例如，PDCP层的处理由相应的PDCP层实体实现。
通常，层二提供的在终端设备和接入网设备之间传输用户数据的服务可以称为无线承载(radio bearer，RB)。对于MBS，层二提供的在终端设备和接入网设备之间传输用户数据的服务可以称为MRB。示例性的，该在终端设备和接入网设备之间传输用户数据的服务可以由上述属于层二的各个协议层实现。
需要说明的是，上述图7所示的用户面协议栈对本申请的方案不构成任何限定。在实际应用中，用户面协议栈可以包括比图示更多或更少的协议层。
3、组播业务建立：
示例性的，以5G系统为例，如图8所示，组播业务建立流程可以包括如下步骤：
S801、UE向AMF网元发送PDU会话修改请求(PDU Session Modification Request)消息。相应的，AMF网元接收来自UE的PDU会话修改请求消息。
其中，PDU会话修改请求消息可以包括MBS会话的标识(identifier，ID)，例如TMGI，指示UE请求加入的组播组。
该PDU会话修改请求消息为NAS消息。AMF网元收到该PDU会话修改请求消息后，可以发送给SMF网元。
S802、AMF网元向gNB发送PDU会话建立请求(PDU Session Setup Request)消息或PDU会话修改请求(PDU Session Modification Request)消息。相应的，gNB接收来自AMF网元的PDU会话建立请求消息或PDU会话修改请求消息。
示例性的，PDU会话建立请求消息或PDU会话修改请求消息可以包括组播会话信息和PDU会话修改信息。例如，组播会话信息可以包括UE请求加入的MBS会话(或组播组)的相关信息。PDU会话修改信息可以指示MBS会话关联的PDU会话，以及MBS会话的QoS流关联的单播QoS流等。
可选的，该组播会话信息和PDU会话修改信息可以是SMF网元生成并发送给AMF网元的。
gNB收到该PDU会话建立请求消息或PDU会话修改请求消息后，若未建立UE请求加入的MBS会话的共享传输通道，执行下述步骤S803。
S803、建立MBS会话的共享传输通道。示例性的，该共享传输通道用于核心网和接入网之间的数据传输。
可选的，步骤S803中涉及到的网元可以包括gNB、AMF网元、SMF网元、MB-SMF网元、或MB-UPF网元等。为了便于描述，图8中仅示出了其中涉及的gNB、AMF网元、和MB-UPF网元，但并不限制参与步骤S803的网元只有gNB、AMF网元、和MB-UPF网元。
S804、gNB向UE发送RRC消息。
示例性的，该RRC消息中可以包括N1会话管理(session management，SM)容器(container)(例如PDU会话修改命令(PDU Session Modification Command))和MRB配置信息(用于为上述MBS会话建立MRB)。
示例性的，PDU会话修改命令可以是AMF网元生成，并通过gNB发送至UE的。
S805、gNB向AMF网元发送PDU会话建立响应(PDU Session Setup Response)消息或PDU会话修改响应(PDU Session Modification Response)消息。相应的，AMF网元接收来自gNB的PDU会话建立响应消息或PDU会话修改响应消息。
示例性的，该PDU会话建立响应消息或PDU会话修改响应消息可以答复组播业务建立情况，例如，答复组播业务建立成功等。
S806、MB-UPF网元通过MBS会话向gNB发送多播数据。相应的，gNB接收来自MB-UPF网元的多播数据。
S807、gNB通过MRB向UE发送多播数据。相应的，UE接收来自gNB的多播数据。
需要说明的是，图8仅示出了组播业务会话建立流程中的部分步骤，以及部分核心网设备(例如AMF网元)的实现。实际实现中，组播业务会话建立流程可以涉及比图8所示更多的网元，包括比图8所示更多的步骤。
4、MBS会话去激活(deactivation)：
示例性的，以5G系统为例，如图9所示，MBS会话激活流程可以包括如下步骤：
S901、AMF网元向gNB发送多播会话去激活请求(Multicast Session Deactivation Request)消息。相应的，gNB接收来自AMF网元的多播会话去激活请求消息
可选的，MBS会话去激活流程可以由MB-SMF网元触发。示例性的，MB-SMF网元可以在收到应用 功能(application function，AF)网元的去激活请求，或者收到MB-UPF网元的通知(MB-UPF网元通知在一段时间内没有下行数据传输)时，触发MBS会话的去激活流程，向AMF网元发送去激活请求，以使AMF网元执行该步骤S901。
S902、gNB将MBS会话的状态设置为去激活。
S903、gNB向AMF网元发送多播会话去激活响应(Multicast Session Deactivation Response)消息。相应的，AMF网元接收来自gNB的多播会话去激活响应消息。
示例性的，该多播会话去激活响应消息可以答复MBS会话的去激活情况，例如，答复MBS会话去激活成功。
可选的，AMF网元收到多播会话去激活响应消息后，可以向MB-SMF网元发送响应消息答复MBS会话的去激活情况。
可选的，在去激活MBS会话后，gNB停止向UE传输MBS会话的数据。gNB还可以释放UE连接，示例性的，释放UE连接可以通过RRC消息实现。或者，gNB可以不释放UE连接。此外，UE不感知MBS会话的去激活，网络侧没有显式的去激活通知发送给UE。
需要说明的是，图9仅示出了MBS会话去激活流程中的部分步骤，以及部分核心网设备(例如AMF网元)的实现。实际实现中，MBS会话去激活流程可以涉及比图9所示更多的网元，包括比图9所示更多的步骤。
5、MBS会话激活(activation)：
示例性的，以5G系统为例，如图10所示，MBS会话激活流程可以包括如下步骤：
S1001、AMF网元向gNB发送多播会话激活请求(Multicast Session Activation Request)消息。相应的，gNB接收来自AMF网元的多播会话激活请求消息
可选的，MBS会话激活流程可以由MB-SMF网元触发。示例性的，MB-SMF网元可以在收到应用功能(application function，AF)网元的激活请求，或者收到MB-UPF网元的通知(关于下行MBS数据的通知)时，触发MBS会话的激活流程，向AMF网元发送激活请求，以使AMF网元执行该步骤S1001。
可选的，MB-SMF网元触发MBS会话激活流程时，加入该MBS会话的UE将被寻呼。若某个UE处于RRC空闲态，在该步骤S1001之前，可以先为该UE重新建立连接(例如建立PDU会话等)。示例性的，为UE重新建立连接可以包括：AMF网元向gNB发送PDU会话建立请求消息。
S1002、gNB向AMF网元发送多播会话激活响应(Multicast Session Activation Response)消息。相应的，AMF网元接收来自gNB的多播会话激活响应消息。
示例性的，该多播会话激活响应消息可以答复MBS会话的激活情况，例如，答复MBS会话激活成功。
可选的，AMF网元收到多播会话激活响应消息后，可以向MB-SMF网元发送响应消息答复MBS会话的激活情况。
可选的，在激活MBS会话后，gNB可以向UE传输MBS会话的数据。
需要说明的是，图10仅示出了MBS会话激活流程中的部分步骤，以及部分核心网设备(例如AMF网元)的实现。实际实现中，MBS会话激活流程可以涉及比图10所示更多的网元，包括比图10所示更多的步骤。
对于组播业务，为了使参与该组播业务传输的不同接入网设备针对该组播业务的同一数据包生成相同的COUNT值，核心网设备可以为该组播业务的数据包生成MBS QFI SN。各个接入网设备收到来自核心网的数据包后，可以根据该数据包的MBS QFI SN生成相同的COUNT值。其中，QFI指QoS流标识(QoS flow identifier，QFI)，SN指序列号(sequence number，SN)。
需要说明的是，本申请中的COUNT值指PDCP层COUNT值，其结构如图1所示，由高位的超帧号(hyper frame number，HFN)和低位的PDCP SN组成。此外，本申请中的“COUNT值”也可以称为(或描述为)“COUNT”，二者可以相互替换。
此外，对于组播业务，先后加入同一个组播业务的终端设备对应接入网设备侧的同一MRB，为了使不同时间加入同一组播业务的终端设备和接入网设备的COUNT值同步，在接入网设备为终端设备新建或配置MRB时，接入网设备需要向终端设备指示初始COUNT值。例如，接入网设备需要在PDCP配置中通过multicastHFN-AndRefSN信元向终端设备指示该初始COUNT值。
然而，接入网设备在配置MRB时，可能还未收到来自核心网设备的数据包，而协议又规定接入网设备为终端设备配置MRB时必须指示初始COUNT值，此时，接入网设备如何配置MRB以指示初始COUNT 值为亟待解决的问题。
基于此，本申请提供一种通信方法，使得接入网设备在未收到核心网的数据包的情况下，仍然能够及时地向终端设备指示初始COUNT值。
下面将结合附图，以图2所示的接入网设备、核心网设备、以及终端设备之间的交互为例，对本申请实施例提供的方法进行展开说明。
可以理解的，本申请实施例中，执行主体可以执行本申请实施例中的部分或全部步骤，这些步骤或操作仅是示例，本申请实施例还可以执行其它操作或者各种操作的变形。此外，各个步骤可以按照本申请实施例呈现的不同的顺序来执行，并且有可能并非要执行本申请实施例中的全部操作。
需要说明的是，本申请下述实施例中各个设备的名称以及各个设备之间的消息名字或消息中各参数的名字等只是一个示例，实施时也可以是其他的名字，本申请实施例对此不作具体限定。
如图11所示，为本申请实施例提供的一种通信方法。该通信方法包括如下步骤：
S1101、第一核心网设备获取第一MBS会话对应的初始MBS QFI SN。其中，该第一MBS会话对应的初始MBS QFI SN用于确定初始HFN和参考SN。
可选的，本申请中的初始MBS QFI SN实质上为序号或编号，即该步骤S1101可以为：第一核心网设备获取第一MBS会话对应的序号或编号。初始MBS QFI SN仅是对第一核心网设备在该步骤S1101中获取的该序号或编号的一种示例性称呼，本申请对该序号或编号的名称不作具体限定。
可选的，该初始MBS QFI SN不针对某个具体的数据包，即初始MBS QFI SN不是某个数据包的MBS QFI SN。当然，某个数据包的MBS QFI SN可以和该初始MBS QFI SN相同。
可选的，第一核心网设备可以是移动管理网元、会话管理网元、多播广播会话管理网元、或多播广播用户面网元中的一项。
可选的，第一MBS会话对应的初始MBS QFI SN可以是QoS流粒度的。示例性的，第一MBS会话对应的初始MBS QFI SN包括该第一MBS会话的至少一个QoS流的初始MBS QFI SN。例如，以第一MBS会话包括QoS流1(使用QFI 1标识)、QoS流2(使用QFI 2标识)、以及QoS流3(使用QFI 3标识)为例，第一MBS会话对应的初始MBS QFI SN可以包括以下至少一项：QoS流1的初始MBS QFI SN、QoS流2的初始MBS QFI SN、或QoS流3的初始MBS QFI SN。
或者，第一MBS会话对应的初始MBS QFI SN可以是MBS会话粒度的。示例性的，第一MBS会话对应的初始MBS QFI SN包括该第一MBS会话的初始MBS QFI SN。若第一MBS会话包括多个QoS流，第一MBS会话的初始MBS QFI SN可以为该多个QoS流的初始MBS QFI SN之和。或者，第一MBS会话的每个QoS流的初始MBS QFI SN可以均为该第一MBS会话的初始MBS QFI SN，即各个QoS流的初始MBS QFI SN可以相同。若第一MBS会话仅包括一个QoS流，第一MBS会话的初始MBS QFI SN即为该QoS流的初始MBS QFI SN。
S1102、第一核心网设备在第一流程中向网络设备发送第一MBS会话对应的初始MBS QFI SN。相应的，网络设备在第一流程中接收来自第一核心网设备的第一MBS会话对应的初始MBS QFI SN。
可选的，若第一核心网设备为移动管理网元，该网络设备可以为接入网设备；或者，
若第一核心网设备为会话管理网元，该网络设备可以为移动管理网元；或者，
若第一核心网设备为多播广播会话管理网元，该网络设备可以为移动管理网元或会话管理网元；或者，
若第一核心网设备为多播广播用户面网元，该网络设备可以为多播广播会话管理网元或会话管理网元。
其中，第一流程为向接入网设备发送第一MBS会话的第一个数据包之前的流程。具体的，可以为多播广播用户面网元向接入网设备发送第一MBS会话的第一个数据包之前的流程，即第一流程为下述步骤S1105之前的流程。对于接入网设备，第一流程即为接收第一MBS会话的第一个数据包之前的流程。具体的，可以为接收来自多播广播用户面网元的第一MBS会话的第一个数据包之前的流程。
可选的，第一流程也可以理解为：用于准备第一MBS会话的数据传输的流程，或者，用于为第一MBS会话的数据传输做准备的流程。
可选的，在第一核心网设备不是多播广播用户面网元时，由于第一核心网设备可以获知第一流程具体是哪类流程，因此，通过该流程类型，第一核心网设备可以获知第一流程为多播广播用户面网元向接入网设备发送第一MBS会话的第一个数据包之前的流程。其中，第一流程的详细说明将在后续实施例中描述，在此不予赘述。
可选的，第一MBS会话对应的初始MBS QFI SN可以小于或等于第一MBS QFI SN，或者，第一MBS QFI SN减第一MBS会话对应的初始MBS QFI SN小于或等于第一数值。
可选的，第一MBS QFI SN为该第一个数据包的预设MBS QFI SN。若第一MBS会话对应的初始MBS QFI SN为MBS会话粒度，第一MBS QFI SN(或第一个数据包)也为会话粒度。
若第一MBS会话对应的初始MBS QFI SN为QoS流粒度，第一MBS QFI SN(或第一个数据包)也为QoS流粒度。例如，第一MBS会话对应的初始MBS QFI SN包括QoS流1的初始MBS QFI SN、QoS流2的初始MBS QFI SN、和QoS流3的初始MBS QFI SN时，相应的，第一MBS QFI SN包括QoS流1的第一个数据包的预设MBS QFI SN、QoS流2的第一个数据包的预设MBS QFI SN、以及QoS流3的第一个数据包的预设MBS QFI SN。各个QoS流的初始MBS QFI SN及其预设MBS QFI SN满足上述关系。
作为一种可能的实现，第一数值为小于或等于PDCP窗口大小的非负整数。示例性的，PDCP窗口大小的量纲可以为序号或者编号，例如，PDCP窗口大小为X，可以表示PDCP窗口包括X个序号或编号。
示例性的，PDCP窗口大小可以为2PDCP-SN-Size-1。其中，PDCP-SN-Size表示PDCP SN的大小，PDCP SN的大小可以由接入网设备确定并指示给第一核心网设备，取值例如可以为18比特或12比特。若接入网设备未向第一核心网设备指示PDCP SN的大小，第一核心网设备可以默认PDCP SN大小为12比特。或者，PDCP窗口大小也可以为固定数值，可选的该数值可以与PDCP-SN-Size相关。
需要说明的是，本申请中，PDCP SN的大小(size)也可以理解为PDCP SN占用的比特数(或字节数)，或者理解为PDCP SN的长度，三者可以相互替换。类似的，HFN的大小也可以理解为HFN占用的比特数或HFN的长度。
作为另一种可能的实现，第一数值可以为特定的非负整数。例如，协议可以规定第一数值的大小。
其中，在第一核心网设备为移动管理网元，网络设备为接入网设备的情况下，如图12所示，该通信方法还可以包括如下步骤：
S1103、接入网设备根据第一MBS会话对应的初始MBS QFI SN确定初始HFN和参考SN。
作为一种可能的实现，接入网设备可以将第一MBS会话对应的初始MBS QFI SN的N个高位比特的值作为初始HFN，将第一MBS会话对应的初始MBS QFI SN的K个低位比特的值作为参考SN。其中，K为PDCP SN的大小，N为HFN的大小。
作为另一种可能的实现，接入网设备可以根据第一MBS会话对应的初始MBS QFI SN和偏移值，确定初始HFN和参考SN。示例性的，该偏移值可以小于或等于PDCP窗口大小。例如，第一MBS会话对应的初始MBS QFI SN减初始HFN和参考SN指示的初始COUNT值小于或等于PDCP窗口大小。
可选的，接入网设备包括CU，CU包括CU-CP和CU-UP的情况下，可以由CU-CP确定该初始HFN和参考SN。
可选的，该初始HFN和参考SN用于指示初始COUNT值。该初始COUNT值可以理解为新建或重配MRB后，该MRB的第一个或首个COUNT值。或者，该初始COUNT值可以作为状态变量RX_DELIV的初始值。其中，该状态变量RX_DELIV指示终端设备还没有递交上层但等待递交的第一个(first)PDCP服务数据单元(service data unit，SDU)的COUNT值。
可选的，初始HFN可以作为该初始COUNT值的HFN，参考SN可以作为该初始COUNT值的SN。
S1104、接入网设备向终端设备发送初始HFN和参考SN。相应的，终端设备接收来自接入网设备的初始HFN和参考SN。
可选的，接入网设备可以在新建第一MRB或重配第一MRB的流程中向终端设备发送该初始HFN和参考SN。其中，第一MRB为第一MBS会话的MRB。
可选的，该初始HFN和参考SN可以携带在PDCP配置中。进一步的，可以携带在PDCP配置的multicastHFN-AndRefSN信元中。
可选的，终端设备收到该初始HFN和参考SN后，可以确定初始COUNT值。该初始COUNT值可以作为状态变量RX_DELIV的初始值。后续终端设备收到第一MBS会话的数据包时，可以根据该状态变量RX_DELIV的初始值确定其收到的数据包的COUNT值。
可选的，如图13所示，在上述步骤S1104之后，该通信方法还可以包括如下步骤：
S1105、多播广播用户面网元向接入网设备发送第一MBS会话的数据包。相应的，接入网设备接收来自多播广播用户面网元的第一MBS会话的数据包。
其中，第一MBS会话的数据包包括该第一MBS会话的第一个数据包。
可选的，该第一个数据包的(实际)MBS QFI SN大于或等于第一MBS QFI SN。或者，第一个数据包的MBS QFI SN减第一MBS会话对应的初始MBS QFI SN小于或等于第一数值。
可选的，该第一个数据包的(实际)MBS QFI SN、第一MBS QFI SN、和第一MBS会话对应的初始 MBS QFI SN三者位于一个PDCP窗口内。
作为一种可能的示例，该第一个数据包的(实际)MBS QFI SN、第一MBS QFI SN、和第一MBS会话对应的初始MBS QFI SN三者的取值可以相等。
作为另一种可能的示例，该第一个数据包的(实际)MBS QFI SN、第一MBS QFI SN、和第一MBS会话对应的初始MBS QFI SN，三者中任意两者的取值可以相等，例如，第一个数据包的(实际)MBS QFI SN和第一MBS QFI SN的取值可以相等。
基于该方案，在第一数值为小于PDCP窗口大小的非负整数时，使得该第一个数据包的实际MBS QFI SN和第一MBS会话对应的初始MBS QFI SN位于一个PDCP窗口大小内。从而使得接入网设备确定的初始HFN和参考SN指示的初始COUNT值和第一数据包的实际MBS QFI SN位于一个PDCP窗口大小内，进而使得终端设备能够根据该初始COUNT值准确获取后续数据包的COUNT值。此外，允许第一个数据包的(实际)MBS QFI SN、预设MBS QFI SN、和第一MBS会话对应的初始MBS QFI SN在一定范围内不相等，可以提升灵活性。
S1106、接入网设备向终端设备发送第一MBS会话的数据包。相应的，终端设备接收来自接入网设备的第一MBS会话的数据包。
可选的，接入网设备可以通过第一MRB向终端设备发送该第一MBS会话的数据包。终端设备通过该第一MRB接收该数据包。
基于上述方案，核心网设备可以在多播广播用户面网元向接入网设备发送第一MBS会话的第一个数据包之前，发送第一MBS会话对应的初始MBS QFI SN，使得接入网设备能够根据该初始MBS QFI SN确定初始HFN和参考SN，从而向终端设备配置该初始HFN和参考SN，进而使得接入网设备无需等待数据包到达即可及时为终端设备配置MRB，指示初始HFN和参考SN。此外，由于该初始MBS QFI SN为核心网侧提供的参数，因此核心网侧最终可能使用该初始MBS QFI SN作为该第一个数据包的MBS QFI SN，或者根据该初始MBS QFI SN确定该第一个数据包的MBS QFI SN，从而可以提高接入网设备在收到数据包之前配置的初始HFN和参考SN的准确性。
以上对本申请提供的通信方法的整体流程进行了介绍。下面对第一MBS会话对应的初始MBS QFI SN的获取方式和第一流程进行说明。
可选的，第一核心网设备可以通过如下三种方式获取第一MBS会话对应的初始MBS QFI SN：
方式一，第一核心网设备自行确定第一MBS会话对应的初始MBS QFI SN。
可选的，在该方式一中，第一核心设备可以为多播广播会话管理网元，或多播广播用户面网元。
可选的，第一核心网设备为多播广播用户面网元，第二核心网设备为多播广播会话管理网元时，第一核心网设备可以基于第二核心网设备的触发(或请求)自行确定第一MBS会话对应的初始MBS QFI SN。
作为一种可能的实现，第二核心网设备可以向第一核心网设备发送第二信息，该第二信息用于请求第一MBS会话对应的初始MBS QFI SN。第一核心网设备接收来自第二核心网设备的第二信息后，可以根据第二信息确定第一MBS会话对应的初始MBS QFI SN。此外，第一核心网设备还可以向第二核心网设备返回第一MBS会话对应的初始MBS QFI SN。
需要说明的是，本申请还涉及第一信息，该第一信息将在后续实施例中说明，在此不予赘述。
可选的，根据第二信息确定第一MBS会话对应的初始MBS QFI SN，可以理解为：基于第二信息的触发或者请求，确定第一MBS会话对应的初始MBS QFI SN。
可选的，第二信息可以为包转发控制协议(packet forwarding control protocol，PFCP)会话建立(PFCP Session Establishmen)流程或PFCP会话修改流程或者N4多播会话修改(N4mb Session Modification)流程中的信息。例如，第二核心网设备可以在PFCP会话建立或修改流程或者N4多播会话修改流程的请求消息中携带第二信息。第一核心网设备可以在PFCP会话建立或修改流程或者N4多播会话修改流程的响应消息中向第二核心网设备返回第一MBS会话对应的初始MBS QFI SN。
可选的，第二信息可以通过1比特的指示实现。或者，第二信息可以通过被设置为特定值(例如设置为TRUE)的字段实现。当然，第二信息还可以通过其他方式实现，本申请对此不作具体限定。
作为另一种可能的实现，第二核心网设备可以向第一核心网设备发送第四消息，该第四消息用于请求建立或修改PFCP会话。第一核心网设备接收来自第二核心网设备的第四消息后，可以根据第四消息确定第一MBS会话对应的初始MBS QFI SN。此外，第一核心网设备还可以向第二核心网设备返回第一MBS会话对应的初始MBS QFI SN。
需要说明的是，本申请还涉及第一消息、第二消息、第三消息，将在后续实施例中说明，在此不予赘 述。
可选的，根据第四消息确定第一MBS会话对应的初始MBS QFI SN，可以理解为：基于第四消息的触发，确定第一MBS会话对应的初始MBS QFI SN。
可选的，第四消息可以为PFCP会话建立流程或PFCP会话修改流程或者N4多播会话修改流程中的请求消息。第一核心网设备可以在PFCP会话建立或修改流程的响应消息中向第二核心网设备返回第一MBS会话对应的初始MBS QFI SN。
也就是说，在该可能的实现中，第二核心网设备请求建立或修改PFCP会话时，第一核心网设备默认确定第一MBS会话的初始MBS QFI SN。
可选的，第一核心网设备为多播广播会话管理网元时，确定第一MBS会话对应的初始MBS QFI SN后，多播广播会话管理网元还可以向第二核心网设备(多播广播用户面网元)发送该初始MBS QFI SN或第一MBS QFI SN，以便多播广播用户面网元在后续发送第一MBS会话的第一个数据包时，根据初始MBS QFI SN或第一MBS QFI SN确定该第一个数据包的实际MBS QFI SN。
可选的，多播广播会话管理网元可以向多播广播用户面网元发送第四消息，在第四消息中包括第一MBS会话对应的初始MBS QFI SN或第一MBS QFI SN。该第四消息用于请求建立或修改PFCP会话或用于修改N4mb会话。多播广播用户面网元收到第四消息后，可以向多播广播会话管理网元发送第五消息，该第五消息为第四消息的响应消息。
在第五消息指示PFCP会话建立或修改成功或指示N4mb会话修改成功时，表示多播广播用户面网元接受多播广播会话管理网元确定的该第一MBS会话对应的初始MBS QFI SN或第一MBS QFI SN。后续，多播广播会话管理网元可以向移动管理网元发送该初始MBS QFI SN。
可选的，第五消息还可以包括第二MBS QFI SN，该第二MBS QFI SN可以理解为多播广播用户面网元建议的初始MBS QFI SN。多播广播会话管理网元可以接受或不接受多播广播用户面网元建议的该初始MBS QFI SN。
方式二，第一核心网设备可以从第二核心网设备处接收第一MBS会话对应的初始MBS QFI SN。即，第一核心网设备接收来自第二核心网设备的第一MBS会话对应的初始MBS QFI SN。
示例性的，该方式二中，第一核心网设备可以为移动管理网元，相应的，第二核心网设备可以为会话管理网元或多播广播会话管理网元。或者，第一核心网设备可以为多播广播会话管理网元，相应的，第二核心网设备可以为多播广播用户面网元。
作为一种可能的实现，第一核心网设备可以向第二核心网设备发送第二信息。该第二信息用于请求第一MBS会话对应的初始MBS QFI SN。
可选的，第一核心网设备为多播广播会话管理网元时，第一核心网设备可以在PFCP会话建立或修改流程的请求消息中携带第二信息。第二核心网设备可以在PFCP会话建立或修改流程的响应消息中向第一核心网设备返回第一MBS会话对应的初始MBS QFI SN。
作为另一种可能的实现，第一核心网设备为多播广播会话管理网元时，第一核心网设备可以向第二核心网设备发送第四消息，该第四消息用于请求建立或修改PFCP会话或用于修改N4mb会话。第二核心网设备接收来自第一核心网设备的第四消息后，可以在第五消息中向第一核心网设备返回第一MBS会话对应的初始MBS QFI SN。其中，第五消息为第四消息的响应信息。
方式三，第一核心网设备可以从第二核心网设备处接收用于确定第一MBS会话对应的初始MBS QFI SN的参数，根据该参数确定该初始MBS QFI SN。
示例性的，该方式三中，第一核心网设备可以为多播广播会话管理网元，相应的，第二核心网设备可以为多播广播用户面网元。
示例性的，多播广播用户面网元可以向多播广播会话管理网元发送第一MBS QFI SN。相应的，多播广播会话管理网元接收来自多播广播用户面网元的第一MBS QFI SN，并根据第一MBS QFI SN确定第一MBS会话对应的初始MBS QFI SN。其中，第一MBS QFI SN和第一MBS会话对应的初始MBS QFI SN的大小关系可参考上述步骤S1102中的相关说明，在此不再赘述。
可选的，第一核心网设备可以在如下四种流程中向网络设备发送第一MBS会话对应的初始MBS QFI SN，即第一流程可以存在如下四种情况：
情况一，第一流程为共享传输通道建立流程。
其中，共享传输通道建立流程用于为第一MBS会话建立共享传输通道，该共享传输通道用于核心网和接入网之间的数据传输。
可选的，在该情况一下，上述第一MBS会话的第一个数据包，可以指：通过该第一流程新建的共享传输通道传输的第一个数据包。
可选的，第一核心网设备向网络设备发送第一MBS会话对应的初始MBS QFI SN，可以包括：第一核心网设备向网络设备发送第一消息，该第一消息包括第一MBS会话对应的初始MBS QFI SN。其中，第一消息用于建立该共享传输通道。进一步的，第一消息用于承载共享传输通道的地址信息，和/或，第一MBS会话的状态信息。该共享传输通道的地址信息例如可以为共享NG-U多播TNL信息(Shared NG-U Multicast TNL Information)，其中，NG-U指下一代(next generation，NG)用户面(user plane)，TNL指传输网络层(transport network layer，TNL)。
示例性的，共享传输通道的地址信息可以指示互联网协议(internet protocol，IP)组播方式的NG-U隧道(tunnel)地址。第一MBS会话的状态信息可以指示第一MBS会话的状态(MBS Session Status)。
作为一种可能的实现，若第一核心网设备为多播广播用户面网元，网络设备为多播广播会话管理网元，那么，第一消息可以为会话修改响应(Session Modification Response)消息或PFCP会话建立响应消息或PFCP会话修改响应消息。
作为另一种可能的实现，若第一核心网设备为多播广播会话管理网元，网络设备为移动管理网元，那么，第一消息可以为MBS会话上下文更新响应(MBSSession_ContextUpdate Response)消息。
作为又一种可能的实现，若第一核心网设备为移动管理网元，网络设备为接入网设备，那么，第一消息可以为分布建立响应(Distribution Setup Response)消息。
基于上述情况一的相关说明，示例性的，如图14所示，为情况一下本申请提供的通信方法的一种可能的应用流程。参见图14，以移动管理网元为AMF网元，多播广播会话管理网元为MB-SMF网元，多播广播会话管理网元为MB-UPF网元为例，该流程可以包括如下步骤：
S1401、接入网设备确定为第一MBS会话建立共享传输通道。
S1402、接入网设备向AMF网元发送分布建立请求(Distribution Setup Request)消息。相应的，AMF网元接收来自接入网设备的分布建立请求消息。
可选的，该分布建立请求消息可以用于请求建立第一MBS会话的共享传输通道。
S1403、AMF网元向MB-SMF网元发送MBS会话上下文更新请求(MBSSession_ContextUpdate Request)消息。相应的，MB-SMF网元接收来自AMF网元的MBS会话上下文更新请求消息。
可选的，MBS会话上行文更新请求消息用于请求更新第一MBS会话的上下文。此外，AMF网元还可以为第一MBS会话存储接入网设备的信息。MB-SMF网元可以为第一MBS会话存储AMF网元的信息。
S1404、MB-SMF网元向MB-UPF网元发送会话修改请求(Session Modification Request)消息。相应的，MB-UPF网元接收来自MB-SMF网元的会话修改请求消息。
可选的，会话修改请求消息可以用于请求建立或修改第一MBS会话的传输资源。
可选的，该步骤S1404中的会话修改请求消息也可以替换为PFCP会话建立请求消息或PFCP会话修改请求消息。
S1405、MB-UPF网元向MB-SMF网元发送会话修改响应消息。相应的，MB-SMF网元接收来自MB-UPF网元的会话修改响应消息。
可选的，该会话修改响应消息中可以包括第一MBS会话对应的初始MBS QFI SN。该初始MBS QFI SN的获取方式可参考前述相关说明，在此不再赘述。
可选的，该步骤S1405中的会话修改响应消息也可以替换为PFCP会话建立回复消息或PFCP会话修改回复消息。
S1406、MB-SMF网元向AMF网元发送MBS会话上下文更新响应消息。相应的，AMF网元接收来自MB-SMF网元的MBS会话上下文更新响应消息。
其中，该MBS会话上下文更新响应消息可以包括第一MBS会话对应的初始MBS QFI SN。该初始MBS QFI SN可以是上述步骤S1405中的会话修改响应消息中携带的，或者，可以是MB-SMF网元自行确定的。该初始MBS QFI SN的获取方式可参考前述相关说明，在此不再赘述。
S1407、AMF网元向接入网设备发送分布建立响应消息。相应的，接入网设备接收来自AMF网元的分布建立响应消息。
其中，该分布建立响应消息可以包括第一MBS会话对应的初始MBS QFI SN。该初始MBS QFI SN可以是上述步骤S1406中的MBS会话上下文更新响应消息中携带的。
情况二，第一流程为PDU会话建立流程或PDU会话修改流程。
其中，PDU会话建立流程可以用于建立或修改第一MBS会话，PDU会话修改流程也可以用于建立或修改第一MBS会话。
可选的，在该情况二下，上述第一MBS会话的第一个数据包，可以指：第一MBS会话建立或修改完成后第一MBS会话的第一个数据包。
可选的，第一核心网设备向网络设备发送第一MBS会话对应的初始MBS QFI SN，可以包括：第一核心网设备向网络设备发送第二消息，该第二消息包括第一MBS会话对应的初始MBS QFI SN。第二消息用于承载第一MBS会话的标识。
作为一种可能的实现，若第一核心网设备为会话管理网元或多播广播会话管理网元，网络设备为移动管理网元，那么，第二消息可以为PDU会话更新会话管理(session management，SM)上下文响应(PDUSession_UpdateSMContext Response)消息。
作为另一种可能的实现，若第一核心网设备为移动管理网元，网络设备为接入网设备，那么，第二消息可以为PDU会话资源修改请求(PDU Session Resource Setup Request)消息。
可选的，若某个终端设备为接入网设备服务的多个终端设备中，第一个请求加入第一MBS会话的终端设备，那么该终端设备的加入第一MBS会话的请求，可以触发第一核心网设备在PDU会话建立流程或PDU会话修改流程中发送第一MBS会话对应的初始MBS QFI SN。若某个终端设备不是该接入网设备服务的多个终端设备中第一个请求加入第一MBS会话的终端设备，那么该终端设备的加入第一MBS会话的请求，不触发第一核心网设备在PDU会话建立流程或PDU会话修改流程中发送第一MBS会话对应的初始MBS QFI SN，即第一核心网设备不在该终端设备的PDU会话建立流程或PDU会话修改流程中发送第一MBS会话对应的初始MBS QFI SN。
基于上述情况二的相关说明，示例性的，如图15所示，为情况二下本申请提供的通信方法的一种可能的应用流程。参见图15，以移动管理网元为AMF网元，多播广播会话管理网元为MB-SMF网元，多播广播会话管理网元为MB-UPF网元为例，该流程可以包括如下步骤：
S1501、终端设备向AMF网元发送上行NAS消息。相应的，AMF网元接收来自终端设备的该上行NAS消息。
可选的，该NAS消息可以包括PDU会话修改请求。该PDU会话修改请求可以包括第一MBS会话的标识，表示终端设备请求加入第一MBS会话。
S1502、AMF网元向SMF网元发送PDU会话更新SM上下文请求(PDUSession_UpdateSMContext Request)消息。相应的，SMF网元接收来自AMF网元的PDU会话更新SM上下文请求消息。
可选的，该PDU会话更新SM上下文请求消息用于发送上述步骤S1501中的NAS消息。
S1503、SMF网元通过MB-SMF网元向MB-UPF网元请求第一MBS会话的初始MBS QFI SN。
S1504、MB-UPF网元通过MB-SMF网元向SMF网元返回第一MBS会话的初始MBS QFI SN。
S1505、SMF网元向AMF网元发送PDU会话更新SM上下文响应消息。相应的，AMF网元接收来自SMF网元的PDU会话更新SM上下文响应消息。
其中，该PDU会话更新SM上下文响应消息包括第一MBS会话的初始MBS QFI SN。
S1506、AMF网元向接入网设备发送PDU会话资源修改请求消息。相应的。接入网设备接收来自AMF网元的PDU会话资源修改请求消息。
其中，该PDU会话资源修改请求消息可以包括第一MBS会话的初始MBS QFI SN。
可选的，接入网设备收到该PDU会话资源修改请求消息后，可以和终端设备进行RRC消息的交互，实现PDU会话的修改。之后，接入网设备可以向AMF网元发送PDU会话资源修改响应消息。
可选的，图15所示流程以MB-UPF网元确定第一MBS会话的初始MBS QFI SN为例进行说明。此外，该第一MBS会话的初始MBS QFI SN也可以由MB-SMF网元确定。此时，上述步骤S1503和步骤S1504可以替换为下述步骤S1503’和S1504’。
S1503’、SMF网元向MB-SMF网元请求第一MBS会话的初始MBS QFI SN。
S1504’、MB-SMF网元向SMF网元返回第一MBS会话的初始MBS QFI SN。
情况三，第一流程为MBS会话更新流程。
其中，该MBS会话更新流程用于在第一MBS会话中添加QoS流。为了方便描述，本申请下述实施例将第一MBS会话中添加的QoS流称为第一QoS流。可以理解的是，该第一QoS流可以指添加的一个或多个QoS流。
可选的，在该情况三下，上述第一MBS会话的第一个数据包，可以指：第一MBS会话的第一QoS流 的第一个数据包。
可选的，第一核心网设备向网络设备发送第一MBS会话对应的初始MBS QFI SN，可以包括：第一核心网设备向网络设备发送第二消息，该第二消息包括第一MBS会话对应的初始MBS QFI SN。第二消息用于承载第一MBS会话的标识。
作为一种可能的实现，若第一核心网设备为多播广播会话管理网元，网络设备为移动管理网元，那么，第二消息可以为MBS通信N2消息传输(MBSCommunication_N2Message Transfer)消息。
作为另一种可能的实现，若第一核心网设备为移动管理网元，网络设备接入网设备，那么，第二消息可以为MBS会话更新请求(MBS Session Update Request)消息。
基于上述情况三的相关说明，示例性的，如图16所示，为情况三下本申请提供的通信方法的一种可能的应用流程。参见图16，以移动管理网元为AMF网元，多播广播会话管理网元为MB-SMF网元，多播广播会话管理网元为MB-UPF网元为例，该流程可以包括如下步骤：
S1601、MB-SMF网元确定第一MBS会话的更新被触发。
S1602、MB-SMF网元向MB-UPF网元发送消息a。相应的，MB-UPF网元接收来自MB-SMF网元的消息a。
其中，该消息a用于请求第一MBS会话对应的初始MBS QFI SN。
S1603、MB-UPF网元向MB-SMF网元发送消息b。相应的，MB-SMF网元接收来自MB-UPF网元的消息b。
其中，该消息b包括第一MBS会话对应的初始MBS QFI SN。或者，该消息b包括用于确定该初始MBS QFI SN的参数。
S1604、MB-SMF网元向AMF网元发送MBS通信N2消息传输消息。相应的，AMF网元接收来自MB-SMF网元的MBS通信N2消息传输消息。
可选的，该MBS通信N2消息传输消息用于传输更新的MBS会话信息。
其中，该MBS通信N2消息传输消息包括第一MBS会话对应的初始MBS QFI SN。
S1605、AMF网元向接入网设备发送MBS会话更新请求消息。相应的，接入网设备接收来自AMF网元的MBS会话更新请求消息。
可选的，该MBS会话更新请求消息用于在第一MBS会话中添加第一QoS流。
其中，该MBS会话更新请求消息包括第一MBS会话的初始MBS QFI SN。
S1606、接入网设备向终端设备发送RRC消息。相应的，终端设备接收来自接入网设备的RRC消息。
其中，该RRC消息可以用于重配或添加第一QoS流对应的MRB。该RRC消息中可以包括接入网设备确定的初始HFN和参考SN。
S1607、接入网设备向AMF网元发送MBS会话更新响应(MBS Session Update Response)消息。相应的，AMF网元接收来自接入网设备的MBS会话更新响应消息。
可选的，图16所示流程以MB-UPF网元确定第一MBS会话的初始MBS QFI SN为例进行说明。此外，该第一MBS会话的初始MBS QFI SN也可以由MB-SMF网元确定。此时，上述步骤S1602和步骤S1603可以不执行，步骤S1604中的第一MBS会话对应的初始MBS QFI SN由MB-SMF网元自行确定。
情况四，第一流程为组播会话激活流程。
其中，该组播会话激活流程用于激活第一MBS会话。
可选的，在该情况四下，上述第一MBS会话的第一个数据包，可以指：第一MBS会话被激活后的第一个数据包。
可选的，第一核心网设备向网络设备发送第一MBS会话对应的初始MBS QFI SN，可以包括：第一核心网设备向网络设备发送第二消息，该第二消息包括第一MBS会话对应的初始MBS QFI SN。第二消息用于承载第一MBS会话的标识。
作为一种可能的实现，若第一核心网设备为多播广播会话管理网元，网络设备为移动管理网元，那么，第二消息可以为MBS通信N2消息传输请求(MBSCommunication_N2Message Transfer Request)消息。
作为另一种可能的实现，若第一核心网设备为移动管理网元，网络设备接入网设备，那么，第二消息可以为多播会话激活请求(Multicast Session Activation Request)消息或PDU会话建立请求消息。其中，该PDU会话建立请求消息用于为处于RRC非激活态的终端设备重新建立连接，以使该终端设备在第一MBS会话激活后能够接收第一MBS会话的数据。
基于上述情况四的相关说明，示例性的，如图17所示，为情况四下本申请提供的通信方法的一种可能 的应用流程。参见图17，以移动管理网元为AMF网元，多播广播会话管理网元为MB-SMF网元，多播广播会话管理网元为MB-UPF网元为例，该流程可以包括如下步骤：
S1701、MB-SMF网元确定第一MBS会话激活被触发。
S1702、MB-SMF网元向MB-UPF网元发送消息a。相应的，MB-UPF网元接收来自MB-SMF网元的消息a。
其中，该消息a用于请求第一MBS会话对应的初始MBS QFI SN。
S1703、MB-UPF网元向MB-SMF网元发送消息b。相应的，MB-SMF网元接收来自MB-UPF网元的消息b。
其中，该消息b包括第一MBS会话对应的初始MBS QFI SN。或者，该消息b包括用于确定该初始MBS QFI SN的参数。
S1704、MB-SMF网元向AMF网元发送MBS通信N2消息传输请求消息。相应的，AMF网元接收来自MB-SMF网元的MBS通信N2消息传输请求消息。
可选的，该MBS通信N2消息传输请求消息用于请求激活第一MBS会话。
其中，该MBS通信N2消息传输请求消息包括第一MBS会话对应的初始MBS QFI SN。
S1705、AMF网元向接入网设备发送多播会话激活请求消息。相应的，接入网设备接收来自AMF网元的多播会话激活请求消息。
可选的，该多播会话激活请求消息用于请求激活第一MBS会话。
其中，该多播会话激活请求消息包括第一MBS会话的初始MBS QFI SN。
S1706、接入网设备向AMF网元发送多播会话激活响应(Multicast Session Activation Response)消息。
S1707、AMF网元向MB-SMF网元发送MBS通信N2消息传输响应(MBSCommunication_N2Message Transfer Response)消息。相应的，MB-SMF网元接收来自AMF网元的MBS通信N2消息传输响应消息。
可选的，图17所示流程以MB-UPF网元确定第一MBS会话的初始MBS QFI SN为例进行说明。此外，该第一MBS会话的初始MBS QFI SN也可以由MB-SMF网元确定。此时，上述步骤S1702和步骤S1703可以不执行，步骤S1704中的第一MBS会话对应的初始MBS QFI SN由MB-SMF网元自行确定。
情况五，第一流程为组播会话去激活流程。
其中，该组播会话去激活流程用于去激活第一MBS会话。
可选的，在该情况五下，上述第一MBS会话的第一数据包，可以指：去激活第一MBS会话后再激活第一MBS会话后的第一个数据包。
可选的，在该情况五下，第一MBS会话对应的初始MBS QFI SN可以为：去激活第一MBS会话时，当前已经使用的第一MBS会话的最大MBS QFI SN。该场景下，去激活第一MBS会话后再激活第一MBS会话后的第一个数据包的MBS QFI SN可以大于该当前已使用的最大MBS QFI SN。
或者，该初始MBS QFI SN可以为：去激活第一MBS会话时，当前已经使用的第一MBS会话的最大MBS QFI SN加M，M为正整数。该场景下，去激活第一MBS会话后再激活第一MBS会话后的第一个数据包的MBS QFI SN可以大于或等于该最大MBS QFI SN加M。
示例性的，以初始MBS QFI SN为已经使用的最大MBS QFI SN为例，假设截止第一MBS会话被去激活，当前已经使用的第一MBS会话的最大MBS QFI SN为10000，那么可以将10000作为第一MBS会话被重新激活后对应的初始MBS QFI SN。
可选的，第一核心网设备向网络设备发送第一MBS会话对应的初始MBS QFI SN，可以包括：第一核心网设备向网络设备发送第六消息，该第六消息包括第一MBS会话对应的初始MBS QFI SN。
作为一种可能的实现，第一核心网设备可以为多播广播用户面网元，网络设备可以为多播广播会话管理网元。该场景下，第六消息可以为PFCP会话修改响应(PFCP Session Modification Response)消息。
可选的，多播广播会话管理网元收到该初始MBS QFI SN后，可以保存该初始MBS QFI SN。后续有接入网设备触发建立共享传输通道时，多播广播会话管理网元可以向该接入网设备发送其保存的初始MBS QFI SN，从而无需向多播广播用户面网元发送PFCP会话修改请求(PFCP Session Modification Request)消息以请求初始MBS QFI SN，减少了多播广播会话管理网元和多播广播用户面网元之间的交互，节省了通信开销。此外，多播广播会话管理网元在接入网设备触发建立共享传输通道时向接入网设备发送其保存的初始MBS QFI SN，可以使得接入网设备能够及时为终端设备配置MRB。
可选的，该触发建立共享传输通道的接入网设备可以是：第一MBS会话被去激活前未加入第一MBS会话的接入网设备；或者，第一MBS会话被去激活前已经加入第一MBS会话的接入网设备。
可选的，若接入网设备在第一MBS会话被去激活前已经加入第一MBS会话，在第一MBS会话被去激活时，该接入网设备与核心网之间的共享传输通道可能被删除，从而，该接入网设备再次加入第一MBS会话时，需要再次触发共享传输通道的建立。
作为另一种可能的实现，第一核心网设备可以为多播广播会话管理网元，网络设备可以为接入网设备,可选的可以是接入网设备的CU-CP。该场景下，第六消息可以为多播会话去激活请求(Multicast Session Deactivation Request)消息。
可选的，接入网设备的CU-CP收到该初始MBS QFI SN后，可以保存该初始MBS QFI SN。
后续有终端设备请求加入第一MBS会话时，按照现有技术的方案，接入网设备的CU-CP需要向接入网设备的CU-UP请求已经使用的最大或者将要使用的MBS QFI SN或COUNT值，之后再配置MRB。
基于本申请实施例的该方案，由于接入网设备的CU-CP保存了来自多播广播会话管理网元的初始MBS QFI SN，因此，接入网设备的CU-CP无需向接入网设备的CU-UP请求已经使用的最大或者将要使用的MBS QFI SN或COUNT值，即可向该终端设备配置MRB，从而减少CU-CP和CU-UP之间的交互，节省通信开销。
基于上述情况五的相关说明，示例性的，如图18a所示，为情况五下本申请提供的通信方法的一种可能的应用流程。参见图18a，以移动管理网元为AMF网元，多播广播会话管理网元为MB-SMF网元，多播广播会话管理网元为MB-UPF网元，gNB1为第一MBS会话被去激活前已经加入第一MBS会话的接入网设备，可选的，gNB1可以包括CU-CP，下述由gNB1实现的功能也可以由gNB1的CU-CP实现，gNB2为第一MBS会话被去激活前未加入第一MBS会话的接入网设备为例，该流程可以包括如下步骤：
S1801a、MB-UPF网元向MB-SMF网元发送PFCP会话通知(PFCP Session Notification)消息。相应的，MB-SMF网元接收来自MB-UPF网元的PFCP会话通知消息。
可选的，该PFCP会话通知消息用于通知MB-SMF网元去激活第一MBS会话。示例性的，MB-UPF网元可以在没有接收到第一MBS会话的数据时发送该PFCP会话通知消息。
S1802a、MB-SMF网元向MB-UPF网元发送PFCP会话修改请求(PFCP Session Modification Request)消息。相应的，MB-UPF网元接收来自MB-SMF网元的PFCP会话修改请求消息。
可选的，该PFCP会话修改请求用于请求MB-UPF网元缓存数据，也就是说，请求MB-UPF网元在有第一MBS会话的数据到达时缓存该数据而不是立即发送。
S1803a、MB-UPF网元向MB-SMF网元发送PFCP会话修改响应(PFCP Session Modification Response)消息。相应的，MB-SMF网元接收来自MB-UPF网元的PFCP会话修改响应消息。
其中，该PFCP会话修改响应消息可以包括第一MBS会话对应的初始MBS QFI SN，该初始MBS QFI SN可以为当前已经使用的最大MBS QFI SN，或者为当前已经使用的最大MBS QFI SN加M。
S1804a、MB-SMF网元保存第一MBS会话对应的初始MBS QFI SN。
S1805a、MB-SMF网元向gNB1发送多播会话去激活请求消息。相应的，gNB1接收来自MB-SMF网元的多播会话去激活请求消息。
其中，该多播会话去激活请求消息可以包括第一MBS会话对应的初始MBS QFI SN。
S1806a、gNB1向MB-SMF网元发送多播会话去激活响应消息。相应的，MB-SMF网元接收来自gNB1的多播会话去激活响应消息。
可选的，后续gNB1下的终端设备请求加入第一MBS会话时，gNB1的CU-CP无需向gNB1的CU-UP请求已经使用的最大MBS QFI SN，即可根据步骤S1805a中获取的初始MBS QFI SN该终端设备配置MRB。
S1807a、gNB2向AMF网元发送分布建立请求(Distribution Setup Request)消息。相应的，AMF网元接收来自gNB2的分布建立请求消息。
S1808a、AMF网元向MB-SMF网元发送MBS会话上下文更新请求(MBSSession_ContextUpdate Request)消息。相应的，MB-SMF网元接收来自AMF网元的MBS会话上下文更新请求消息。
其中，步骤S1807a和步骤S1808a的实现可参考上述步骤S1402和步骤S1403的相关说明，在此不再赘述。
S1809a、MB-SMF网元向AMF网元发送MBS会话上下文更新响应消息。相应的，AMF网元接收来自MB-SMF网元的MBS会话上下文更新响应消息。
其中，该MBS会话上下文更新响应消息可以包括第一MBS会话对应的初始MBS QFI SN。该初始MBS QFI SN是MB-SMF网元在上述步骤S1804a中保存的。也就是说，MB-SMF网元无需向MB-UPF网 元网元请求初始MBS QFI SN，减少了MB-SMF网元和MB-UPF网元之间的交互。
S1810a、AMF网元向接入网设备发送分布建立响应消息。相应的，接入网设备接收来自AMF网元的分布建立响应消息。
其中，该分布建立响应消息可以包括第一MBS会话对应的初始MBS QFI SN。该初始MBS QFI SN可以是上述步骤S1809a中的MBS会话上下文更新响应消息中携带的。
可选的，上述gNB1和gNB2可以是相同的接入网设备，也可以是不同的接入网设备，本申请对此不作具体限定。
可以理解的是，本申请并不限定仅在一种流程中发送第一MBS会话的初始MBS QFI SN。实际应用中，第一核心网设备可以在上述五种情况介绍的多种流程中发送第一MBS会话的初始MBS QFI SN。
上述方案中，接入网设备在收到数据包之前，根据来自核心网的第一MBS会话对应的初始MBS QFI SN向终端设备配置初始HFN和参考SN。此外，本申请还提供以下三种方案，为终端设备配置初始HFN和参考SN。
示例性的，方案一可以包括如下步骤：
1)接入网设备在收到第一MBS会话的第一个数据包之前向终端设备配置第一MBS会话的第一MRB。
其中，接入网设备可以向终端设备指示第一MRB的初始HFN和参考SN，该初始HFN和参考SN指示第一MRB的初始COUNT值。该初始HFN和参考SN可以是接入网设备自行确定的。示例性的，接入网设备可以猜测一个HFN和SN作为该初始HFN和参考SN。例如，该初始HFN和参考SN可以为0。
其中，第一MBS会话的第一个数据包可参考前述实施例中的相关说明，在此不再赘述。
2)接入网设备释放第一MBS会话的第一MRB，并建立第一MBS会话的第二MRB。
可选的，接入网设备在收到第一MBS会话的第一个数据包之后，可以判断该第一个数据包中携带的MBS QFI SN和初始COUNT值是否相同，或者，二者的差值是否小于某个阈值(例如PDCP窗口大小)。若二者不相同或差值大于或等于该阈值，接入网设备可以发送信令以释放第一MRB并新建第二MRB。第二MRB的初始COUNT值可以根据第一个数据包中携带的MBS QFI SN确定。
可选的，用于释放第一MRB的信令和用于新建第二MRB的信令可以携带在同一消息中，也可以携带在不同消息中，本申请对此不作具体限定。
示例性的，方案二可以包括：
1)接入网设备在收到第一MBS会话的第一个数据包之前向终端设备配置第一MBS会话的第一MRB。可参考上述方案一中的步骤1)，在此不再赘述。
其中，第一MBS会话的第一个数据包可参考前述实施例中的相关说明，在此不再赘述。
2)接入网设备重配置第一MRB的初始COUNT值。
可选的，接入网设备在收到第一MBS会话的第一个数据包之后，可以判断该第一个数据包中携带的MBS QFI SN和初始COUNT值是否相同，或者，二者的差值是否小于某个阈值(例如PDCP窗口大小的一半)。若二者不相同或差值大于或等于该阈值，接入网设备可以发送RRC重配置消息以重新配置第一MRB的初始COUNT值，该重新配置的初始COUNT值可以根据第一个数据包中携带的MBS QFI SN确定。
可选的，终端设备在收到接入网设备的RRC重配置消息后，可以向接入网设备回复RRC重配置完成消息。在接入网设备包括CU-UP和CU-CP的情况下，CU-UP在收到第一MBS会话的数据后可以暂时不向终端设备发送该数据包，后续CU-CP收到来自终端设备的RRC重配置完成消息后，可以通知CU-UP开始发送第一MBS会话的数据。
基于上述方案一和方案二，接入网设备无需等待数据包到达即可及时为终端设备配置MRB，指示初始HFN和参考SN。
示例性的，方案三可以包括：
接入网设备在收到来自核心网的PDU会话建立请求消息或PDU会话修改请求消息或分布建立响应消息后，可以暂时不为终端设备配置MRB，直到接入网设备收到来自核心网的第一个数据包(携带MBS QFI SN)。即接入网设备在收到第一个数据包后向终端设备配置MRB，根据该第一个数据包的MBS QFI SN向终端设备指示初始COUNT值。其中，PDU会话建立请求消息或PDU会话修改请求消息可以参考上述步骤S802中的相关说明。分布建立响应消息可参考上述步骤S1402中的相关说明，在此不再赘述。
可选的，接入网设备在收到核心网的PDU会话建立请求消息或PDU会话修改请求消息或分布建立响应消息后，收到第一个数据包之前，可以向终端设备发送通信信息，以通知终端设备暂时未配置MRB。
基于该方案三，接入网设备可以根据第一个数据包的MBS QFI SN向终端设备指示初始COUNT值，可以提高配置的该初始COUNT值的准确性。
除上述所示方法外，本申请还提供一种通信方法。如图18b所示，该通信方法可以包括如下步骤：
S1801b、第一核心网设备获取第一信息。
其中，第一信息指示去激活第一MBS会话后再激活第一MBS会话时，第一MBS会话对应的MBS QFI SN是否连续或重置。
可选的，第一核心网设备可以是多播广播会话管理网元或移动管理网元。
可选的，第一核心网设备是移动管理网元时，第一核心网设备获取第一信息，可以包括：移动管理网元接收来自多播广播会话管理网元的第一信息。
S1802b、第一核心网设备向网络设备发送第一信息。相应的，网络设备接收来自第一核心网设备的第一信息。
可选的，第一核心网设备为多播广播会话管理网元时，网络设备可以为移动管理网元。移动管理网元收到该第一信息后，可以向接入网设备发送该第一信息。第一核心网设备为移动管理网元时，网络设备可以为接入网设备。
可选的，第一核心网设备可以向网络设备发送第三消息，在该第三消息中携带第一信息。示例性的：
第三消息可以用于请求建立或修改第一MBS会话，例如，第三消息可以为PDU会话更新SM上下文响应消息或PDU会话资源修改请求消息。
或者，第三消息可以用于去激活第一MBS会话，例如，第三消息可以为多播会话去激活请求消息等。
或者，第三消息可以用于激活所述第一MBS会话，例如，第三消息可以为多播会话激活请求消息等。
或者，第三消息可以用于更新所述第一MBS会话，例如，第三消息可以为MBS会话更新请求消息等。
或者，第三消息可以用于建立第一MBS会话的共享传输通道，第三消息可以为分布建立响应消息等。
可选的，第一核心网设备还可以向网络设备发送第一MBS会话对应的初始MBS QFI SN，可参考上述图11至图18a中的相关说明，在此不再赘述。
可选的，若第一信息指示去激活第一MBS会话后再激活第一MBS会话时，第一MBS会话对应的MBS QFI SN不连续或被重置，接入网设备收到第一MBS会话的去激活请求时，可以释放第一MBS会话的MRB，使得接入网设备可以尽早释放MRB。或者，接入网设备在收到第一MBS会话的激活请求时，可以释放第一MBS会话的MRB再新建MRB。或者，接入网设备在收到第一MBS会话的激活请求时，可以重配第一MBS会话的MRB。
可选的，接入网设备在收到第一MBS会话的激活请求后新建或重配第一MBS会话的MRB时，可以根据第一MBS会话对应的初始MBS QFI SN确定初始HFN和参考SN，并向终端设备指示该初始HFN和参考SN。
基于该方案，可以使得接入网设备在MBS会话激活时，无需等待业务的第一个数据包即可以为终端设备配置MRB，同时可以提高配置初始HFN和参考SN的准确性。此外，相比于收到数据包再配置MRB的方案，可以降低时延。
上述本申请实施例提供的方案中，可以认为第一核心网设备通过控制面向网络设备发送初始MBS QFI SN。此外，核心网设备也可以通过数据面向发送初始MBS QFI SN，即MB-UPF网元可以通过数据面向接入网设备发送初始MBS QFI SN。示例性的，如图22所示，MB-UPF网元在收到接入网设备的业务建立请求或隧道建立请求或PFCP会话建立请求后，可以向接入网设备发送空数据包，在空数据包的包头中携带初始MBS QFI SN。其中，空数据包指只包括数据包头不包括数据(或承载或负载)的数据包。接入网设备收到该空数据包后，可以基于包头中携带的初始MBS QFI SN配置MRB。
然而，核心网对数据面传输通道是否建立成功不感知。例如，在数据面采用IP多播方式时，MB-SMF网元需要向接入网设备发送NG-U地址以便接入网设备加入IP组播组。接入设备成功接收到该NG-U地址并加入IP组播组后，数据面传输通道建立成功。但是，MB-SMF网元和MB-UPF网元并不能感知接入网设备是否接收NG-U地址以及什么时候成功接收NG-U地址并成功加入IP组播组。
在数据面采用PTP NG-U隧道(tunnel)方式时，接入网设备向MB-SMF网元发送NG-U地址以请求建立NG-U隧道。MB-SMF网元可以向接入网设备答复该NG-U隧道建立请求，以建立NG-U隧道。但是，MB-SMF网元和MB-UPF网元同样不能感知接入网设备什么时候收到MB-SMF的答复，即不能感知NG-U隧道是否已成功建立。
在核心网设备无法感知数据面传输通道是否成功建立的情况下，上述空数据包的发送时机尤为重要。若空数据包较早发送，那么可能由于数据面传输通道未建立成功导致接入网设备无法收到空数据包。若空数据包较晚发送，将导致MRB的配置时延较大。
基于此，本申请提供以下三种空数据包的发送方式，以提高接入网设备对空数据包的接收成功率，降低MRB配置时延。
方式一，MB-UPF网元基于定时器(timer)向接入网设备发送空数据包。
可选的，在MB-UPF网元确定需要向接入网设备发送初始MBS QFI SN时，MB-UPF可以启动定时器，在该定时器超时后，向接入网设备发送空数据包，在该空数据包的包头中携带初始MBS QFI SN。
可选的，MB-UPF网元确定需要向接入网设备发送初始MBS QFI SN，可以包括但不限于，MB-UPF网元收到接入网设备的业务建立请求或隧道建立请求或PFCP会话建立请求。
可选的，该定时器的时长可以是MB-UPF网元预设的；或者可以是接入网设备上报的；或者可以是MB-SMF网元向MB-UPF网元指示的；或者可以是管理员通过操作管理维护(operations，administration and maintenance，OAM)平台配置的；或者可以是协议定义的，本申请对此不作具体限定。
基于该方式一，可以通过选择合适的定时器时长，保证MB-UPF网元在合适的时机向接入网设备发送空数据包，以提高接入网设备接收空数据包的成功率。
方式二，MB-UPF网元连续发送N个空数据包。N为大于1的正整数。
可选的，在MB-UPF网元确定需要向接入网设备发送初始MBS QFI SN时，MB-UPF网元可以连续发送N个空数据包，在该空数据包的包头中携带初始MBS QFI SN。
可选的，该N个空数据包的序号可以相同，也可以是连续的N个序号，本申请对此不作具体限定。
可选的，连续发送的空数据包的个数N可以是MB-UPF网元预设的；或者可以是接入网设备上报的；或者可以是MB-SMF网元向MB-UPF网元指示的；或者可以是管理员通过OAM平台配置的；或者可以是协议定义的，本申请对此不作具体限定。
方式三，MB-UPF网元周期性发送空数据包。
可选的，MB-UPF网元可以在确定需要向接入网设备发送初始MBS QFI SN时，开始周期性的向接入网设备发送空数据包，在空数据包的包头中携带初始MBS QFI SN。
可选的，空数据包的发送周期可以是MB-UPF网元预设的；或者可以是MB-SMF网元向MB-UPF网元指示的；或者可以是管理员通过OAM平台配置的；或者可以是协议定义的，本申请对此不作具体限定。
基于方式二或方式三，MB-UPF网元可以重复向接入网设备发送空数据包，使得接入网设备在数据面传输通道建立成功后能够尽快收到空数据包以获取初始MBS QFI SN，进而提高接入网设备接收空数据包的成功率，降低MRB的配置时延。
可选的，若MB-UPF网元支持通过控制面(例如图8至图18a所示的一种或多种流程)和数据面(例如图22所示的流程)发送初始MBS QFI SN，那么最终通过控制面还是数据面发送初始MBS QFI SN，可以由MB-UPF网元决定。或者，可以由MB-SMF网元决定通过控制面(例如图8至图18a所示的一种或多种流程)还是数据面(例如图22所示的流程)发送初始MBS QFI SN。
由MB-SMF网元决定初始MBS QFI SN的发送方式(控制面或数据面)的场景下，作为一种可能的实现，MB-SMF网元可以向MB-UPF网元发送指示信息以显式指示初始MBS QFI SN的发送方式。
示例性的，该指示信息可以为1比特的指示，该1比特被设置为“1(或0)”时，指示通过控制面发送初始MBS QFI SN；该1比特被设置为“0(或1)”时，指示通过数据面发送初始MBS QFI SN。或者，该指示信息可以为布尔型参数，该布尔型参数被设置为“TRUE”时，指示通过控制面发送初始MBS QFI SN；该布尔型参数被设置为“FALSE”时，指示通过数据面发送初始MBS QFI SN。
作为另一种可能的实现，若MB-SMF网元向MB-UPF网元发送的消息中不携带关于初始MBS QFI SN的发送方式的指示信息，MB-UPF网元可以默认通过控制面(或数据面)发送初始MBS QFI SN。
在确定初始MBS QFI SN的发送方式后，MB-UPF网元可以通过该发送方式发送初始MBS QFI SN，以便接入网设备进行MRB配置。
可以理解的是，以上各个实施例中，由接入网设备实现的方法和/或步骤，也可以由可用于该接入网设备的部件(例如处理器、芯片、芯片系统、电路、逻辑模块、或软件例如芯片或者电路)实现；由核心网设备实现的方法和/或步骤，也可以由可用于该核心网设备的部件(例如处理器、芯片、芯片系统、电路、逻辑模块、或软件例如芯片或者电路)实现。
上述主要对本申请提供的方案进行了介绍。相应的，本申请还提供了通信装置，该通信装置用于实现 上述各种方法。该通信装置可以为上述方法实施例中的接入网设备，或者包含上述接入网设备的装置，或者为可用于接入网设备的部件，例如芯片或芯片系统；或者，该通信装置可以为上述方法实施例中的核心网设备，或者包含上述核心网设备的装置，或者为可用于核心网设备的部件，例如芯片或芯片系统。
可以理解的是，该通信装置为了实现上述功能，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单元及算法步骤，本申请能够以硬件或硬件和计算机软件的结合形式来实现。某个功能究竟以硬件还是计算机软件驱动硬件的方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本申请的范围。
本申请实施例可以根据上述方法实施例对通信装置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。
可选的，以通信装置为上述方法实施例中的第一核心网设备为例，图19示出了一种第一核心网设备190的结构示意图。该第一核心网设备190包括处理模块1901和收发模块1902。
在一些实施例中，该第一核心网设备190还可以包括存储模块(图19中未示出)，用于存储程序指令和数据。
在一些实施例中，收发模块1902，也可以称为收发单元用以实现发送和/或接收功能。该收发模块1902可以由收发电路，收发机，收发器或者通信接口构成。
在一些实施例中，收发模块1902，可以包括接收模块和发送模块，分别用于执行上述方法实施例中由第一核心网设备执行的接收和发送类的步骤，和/或用于支持本文所描述的技术的其它过程；处理模块1901，可以用于执行上述方法实施例中由第一核心网设备执行的处理类(例如确定、生成、获取等)的步骤，和/或用于支持本文所描述的技术的其它过程。
在一种可能的实现中：
处理模块1901，用于获取第一MBS会话对应的初始MBS QFI SN，第一MBS会话对应的初始MBS QFI SN用于确定初始超帧号HFN和参考SN；收发模块1902，用于在第一流程中向网络设备发送第一MBS会话对应的初始MBS QFI SN，第一流程为向接入网设备发送第一MBS会话的第一个数据包之前的流程。
可选的，第一MBS会话对应的初始MBS QFI SN包括：第一MBS会话的初始MBS QFI SN，和/或，第一MBS会话的至少一个QoS流的初始MBS QFI SN。
可选的，第一MBS会话对应的初始MBS QFI SN小于或等于第一MBS QFI SN，或者，第一MBS QFI SN减第一MBS会话对应的初始MBS QFI SN小于或等于第一数值。其中，第一MBS QFI SN为第一个数据包的预设MBS QFI SN；第一数值为小于或等于分组数据汇聚协议PDCP窗口大小的非负整数。
可选的，收发模块1902，还用于向接入网设备发送第一MBS会话的第一个数据包，第一MBS会话对应的初始MBS QFI SN小于或等于该第一个数据包的MBS QFI SN，或者，该第一个数据包的MBS QFI SN减第一MBS会话对应的初始MBS QFI SN小于或等于第一数值。
可选的，第一流程为共享传输通道建立流程，共享传输通道建立流程用于为第一MBS会话建立共享传输通道，共享传输通道用于核心网和接入网之间的数据传输。
可选的，收发模块1902，用于向网络设备发送第一MBS会话对应的初始MBS QFI SN，包括：收发模块1902，用于向网络设备发送第一消息，第一消息包括第一MBS会话对应的初始MBS QFI SN，第一消息用于承载共享传输通道的地址信息，和/或，第一MBS会话的状态信息。
可选的，第一流程为PDU会话建立流程或PDU会话修改流程，PDU会话建立流程用于建立或修改第一MBS会话，PDU会话修改流程用于建立或修改第一MBS会话。
可选的，第一流程为MBS会话更新流程，MBS会话更新流程用于在第一MBS会话中添加QoS流。
可选的，第一流程为组播会话激活流程，组播会话激活流程用于激活第一MBS会话。
可选的，收发模块1902，用于向网络设备发送第一MBS会话对应的初始MBS QFI SN，包括：收发模块1902，用于发送第二消息，第二消息包括第一MBS会话对应的初始MBS QFI SN，第二消息用于承载第一MBS会话的标识。
可选的，收发模块1902，还用于向网络设备发送第一信息，第一信息指示去激活第一MBS会话后再激活第一MBS会话时，第一MBS会话对应的MBS QFI SN是否连续或重置。
可选的，收发模块1902，用于向网络设备发送第一信息，包括：收发模块1902，用于向网络设备发送 第三消息，第三消息包括第一信息。其中：第三消息用于请求建立或修改第一MBS会话；或者，第三消息用于去激活第一MBS会话；或者，第三消息用于激活第一MBS会话；或者，第三消息用于更新第一MBS会话；或者，第三消息用于建立第一MBS会话的共享传输通道。
可选的，处理模块1901，用于获取第一MBS会话对应的初始MBS QFI SN，包括：处理模块1901，用于通过收发模块1902接收来自第二核心网设备的第一MBS会话对应的初始MBS QFI SN。
可选的，收发模块1902，还用于向第二核心网设备发送第二信息，第二信息用于请求第一MBS会话对应的初始MBS QFI SN。
可选的，收发模块1902，还用于向第二核心网设备发送第四消息，第四消息用于请求建立或修改包转发控制协议PFCP会话。收发模块1902，还用于接收来自第二核心网设备的第一MBS会话对应的初始MBS QFI SN，包括：收发模块1902，还用于接收来自第二核心网设备的第五消息，第五消息包括第一MBS会话对应的初始MBS QFI SN，第五消息为第四消息的响应消息。
可选的，处理模块1901，用于获取第一MBS会话对应的初始MBS QFI SN，包括：处理模块1901，用于通过收发模块1902接收来自第二核心网设备的第一MBS QFI SN，第一MBS QFI SN为第一个数据包的预设MBS QFI SN；处理模块1901，还用于根据第一MBS QFI SN确定第一MBS会话对应的初始MBS QFI SN。
可选的，收发模块1902，还用于向第二核心网设备发送第一MBS会话对应的初始MBS QFI SN或第一MBS QFI SN，第一MBS QFI SN为第一个数据包的预设MBS QFI SN。
可选的，收发模块1902，还用于向第二核心网设备发送第一MBS会话对应的初始MBS QFI SN或第一MBS QFI SN，包括：可选的，收发模块1902，还用于向第二核心网设备发送第四消息，第四消息用于请求建立或修改PFCP会话，第四消息包括第一MBS会话对应的初始MBS QFI SN或第一MBS QFI SN。收发模块1902，还用于接收来自第二核心网设备的第五消息，第五消息为第四消息的响应消息；第五消息指示PFCP会话建立或修改成功时，指示第二核心网设备接受第一MBS会话对应的初始MBS QFI SN或第一MBS QFI SN。
可选的，处理模块1901，用于确定第一MBS会话对应的初始MBS QFI SN，包括：处理模块1901，用于通过收发模块1902接收来自第二核心网设备的第二信息，第二信息用于请求第一MBS会话对应的初始MBS QFI SN；处理模块1901，还用于根据第二信息，确定第一MBS会话对应的初始MBS QFI SN。
可选的，处理模块1901，用于确定第一MBS会话对应的初始MBS QFI SN，包括：处理模块1901，用于通过收发模块1902接收来自第二核心网设备的第四消息，第四消息用于请求建立或修改PFCP会话；处理模块1901，还用于第一核心网设备根据第四消息，确定第一MBS会话对应的初始MBS QFI SN。
在另一种可能的实现中：
处理模块1901，用于获取第一信息；收发模块1902，用于向网络设备发送该第一信息。其中，第一信息指示去激活第一多播广播业务MBS会话后再激活第一MBS会话时，第一MBS会话的MBS服务质量流标识QFI序列号SN是否连续或重置。
可选的，收发模块1902，用于向网络设备发送第一信息，包括：收发模块1902，用于向网络设备发送第三消息，该第三消息包括第一信息。其中：第三消息用于请求建立或修改第一MBS会话；或者，第三消息用于去激活第一MBS会话；或者，第三消息用于激活第一MBS会话；或者，第三消息用于更新第一MBS会话；或者，第三消息用于建立第一MBS会话的共享传输通道。
可选的，收发模块1902，还用于在第一流程中向网络设备发送第一MBS会话的初始MBS QFI SN。其中，其中，第一MBS会话对应的初始MBS QFI SN用于确定初始超帧号HFN和参考SN。第一流程为向接入网设备发送第一MBS会话的第一个数据包之前的流程。
其中，上述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。
在本申请中，该第一核心网设备190以采用集成的方式划分各个功能模块的形式来呈现。这里的“模块”可以指特定专用集成电路(application-specific integrated circuit，ASIC)，电路，执行一个或多个软件或固件程序的处理器和存储器，集成逻辑电路，和/或其他可以提供上述功能的器件。
在一些实施例中，在硬件实现上，本领域的技术人员可以想到该第一核心网设备190可以采用图5所示的通信装置500的形式。
作为一种示例，图19中的处理模块1901的功能/实现过程可以通过图5所示的通信装置500中的处理器501调用存储器503中存储的计算机执行指令来实现。图19中的收发模块1902的功能/实现过程可 以通过图5所示的通信装置500中的通信接口504来实现。
在一些实施例中，当图19中的第一核心网设备190是芯片或芯片系统时，收发模块1902的功能/实现过程可以通过芯片或芯片系统的输入输出接口(或通信接口)实现，处理模块1901的功能/实现过程可以通过芯片或芯片系统的处理器(或者处理电路)实现。
由于本实施例提供的第一核心网设备190可执行上述方法，因此其所能获得的技术效果可参考上述方法实施例，在此不再赘述。
可选的，以通信装置为上述方法实施例中的接入网设备为例，图20示出了一种接入网设备200的结构示意图。该接入网设备200包括处理模块2001和收发模块2002。
在一些实施例中，该接入网设备200还可以包括存储模块(图20中未示出)，用于存储程序指令和数据。
在一些实施例中，收发模块2002，也可以称为收发单元用以实现发送和/或接收功能。该收发模块2002可以由收发电路，收发机，收发器或者通信接口构成。
在一些实施例中，收发模块2002，可以包括接收模块和发送模块，分别用于执行上述方法实施例中由接入网设备执行的接收和发送类的步骤，和/或用于支持本文所描述的技术的其它过程；处理模块2001，可以用于执行上述方法实施例中由接入网设备执行的处理类(例如确定、生成等)的步骤，和/或用于支持本文所描述的技术的其它过程。
收发模块2002，用于在第一流程中接收来自会话管理网元的第一MBS会话对应的初始MBS QFI SN，第一流程为接收第一MBS会话的第一个数据包之前的流程；处理模块2001，用于根据第一MBS会话对应的初始MBS QFI SN确定初始超帧号HFN和参考SN；收发模块2002，还用于向终端设备发送初始HFN和参考SN。
可选的，第一流程为共享传输通道建立流程，共享传输通道建立流程用于为第一MBS会话建立共享传输通道，共享传输通道用于核心网和接入网之间的数据传输。
可选的，收发模块2002，用于收来自会话管理网元的第一MBS会话对应的初始MBS QFI SN，包括：收发模块2002，用于接收来自会话管理网元的第一消息，第一消息包括第一MBS会话对应的初始MBS QFI SN，第一消息用于承载共享传输通道的地址信息，和/或，第一MBS会话的状态信息。
可选的，第一流程为PDU会话建立流程或PDU会话修改流程，PDU会话建立流程用于建立或修改第一MBS会话，PDU会话修改流程用于建立或修改第一MBS会话。
可选的，第一流程为MBS会话更新流程，MBS会话更新流程用于在第一MBS会话中添加QoS流。
可选的，第一流程为组播会话激活流程，组播会话激活流程用于激活第一MBS会话。
可选的，收发模块2002，用于接收来自会话管理网元的第一MBS会话对应的初始MBS QFI SN，包括：收发模块2002，用于接收来自会话管理网元的第二消息，第二消息包括第一MBS会话对应的初始MBS QFI SN，第二消息用于承载第一MBS会话的标识。
其中，上述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。
在本申请中，该接入网设备200以采用集成的方式划分各个功能模块的形式来呈现。这里的“模块”可以指特定专用集成电路(application-specific integrated circuit，ASIC)，电路，执行一个或多个软件或固件程序的处理器和存储器，集成逻辑电路，和/或其他可以提供上述功能的器件。
在一些实施例中，在硬件实现上，本领域的技术人员可以想到该接入网设备200可以采用图5所示的通信装置500的形式。
作为一种示例，图20中的处理模块2001的功能/实现过程可以通过图5所示的通信装置500中的处理器501调用存储器503中存储的计算机执行指令来实现。图20中的收发模块2002的功能/实现过程可以通过图5所示的通信装置500中的通信接口504来实现。
在一些实施例中，当图20中的接入网设备200是芯片或芯片系统时，收发模块2002的功能/实现过程可以通过芯片或芯片系统的输入输出接口(或通信接口)实现，处理模块2001的功能/实现过程可以通过芯片或芯片系统的处理器(或者处理电路)实现。
由于本实施例提供的接入网设备200可执行上述方法，因此其所能获得的技术效果可参考上述方法实施例，在此不再赘述。
作为一种可能的产品形态，本申请实施例所述的接入网设备或核心网设备，还可以使用下述来实现：一个或多个现场可编程门阵列(field programmable gate array，FPGA)、可编程逻辑器件(programmable logic  device，PLD)、控制器、状态机、门逻辑、分立硬件部件、任何其它适合的电路、或者能够执行本申请通篇所描述的各种功能的电路的任意组合。
作为另一种可能的产品形态，本申请实施例所述的接入网设备，可以由一般性的总线体系结构来实现。为了便于说明，参见图21，图21是本申请实施例提供的通信装置2100的结构示意图，该通信装置2100包括处理器2101和收发器2102。该通信装置2100可以为接入网设备，或其中的芯片或模块。图21仅示出了通信装置2100的主要部件。除处理器2101和收发器2102之外，所述通信装置还可以进一步包括存储器2103。
可选的，处理器2101主要用于对通信协议以及通信数据进行处理，以及对整个通信装置进行控制，执行软件程序，处理软件程序的数据。存储器2103主要用于存储软件程序和数据。收发器2102可以包括射频电路和天线，射频电路主要用于基带信号与射频信号的转换以及对射频信号的处理。天线主要用于收发电磁波形式的射频信号。
可选的，处理器2101、收发器2102、以及存储器2103可以通过通信总线连接。
当通信装置开机后，处理器2101可以读取存储器2103中的软件程序，解释并执行软件程序的指令，处理软件程序的数据。当需要通过无线发送数据时，处理器2101对待发送的数据进行基带处理后，输出基带信号至射频电路，射频电路将基带信号进行射频处理后将射频信号通过天线以电磁波的形式向外发送。当有数据发送到通信装置时，射频电路通过天线接收到射频信号，将射频信号转换为基带信号，并将基带信号输出至处理器2101，处理器2101将基带信号转换为数据并对该数据进行处理。
在另一种实现中，所述的射频电路和天线可以独立于进行基带处理的处理器而设置，例如在分布式场景中，射频电路和天线可以与独立于通信装置，呈拉远式的布置。
在一些实施例中，本申请实施例还提供一种通信装置，该通信装置包括处理器，用于实现上述任一方法实施例中的方法。
作为一种可能的实现方式，该通信装置还包括存储器。该存储器，用于保存必要的计算机程序和数据。该计算机程序可以包括指令，处理器可以调用存储器中存储的计算机程序中的指令以指令该通信装置执行上述任一方法实施例中的方法。当然，存储器也可以不在该通信装置中。
作为另一种可能的实现方式，该通信装置还包括接口电路，该接口电路为代码/数据读写接口电路，该接口电路用于接收计算机执行指令(计算机执行指令存储在存储器中，可能直接从存储器读取，或可能经过其他器件)并传输至该处理器。
作为又一种可能的实现方式，该通信装置还包括通信接口，该通信接口用于与该通信装置之外的模块通信。
可以理解的是，该通信装置可以是芯片或芯片系统，该通信装置是芯片系统时，可以由芯片构成，也可以包含芯片和其他分立器件，本申请实施例对此不作具体限定。
本申请还提供了一种计算机可读存储介质，其上存储有计算机程序或指令，该计算机程序或指令被计算机执行时实现上述任一方法实施例的功能。
本申请还提供了一种计算机程序产品，该计算机程序产品被计算机执行时实现上述任一方法实施例的功能。
本领域普通技术人员可以理解，为描述的方便和简洁，上述描述的系统、装置和单元的具体工作过程，可以参考前述方法实施例中的对应过程，在此不再赘述。
可以理解，本申请中描述的系统、装置和方法也可以通过其它的方式实现。例如，以上所描述的装置实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个系统，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口，装置或单元的间接耦合或通信连接，可以是电性，机械或其它的形式。
所述作为分离部件说明的单元可以是或者也可以不是物理上分开的，即可以位于一个地方，或者也可以分布到多个网络单元上。作为单元显示的部件可以是或者也可以不是物理单元。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。
另外，本申请各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个单元中。
在上述实施例中，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。当使用软件程序实现时，可以全部或部分地以计算机程序产品的形式来实现。该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计算机程序指令时，本申请实施例所述的全部或部分流程(或功能)被实现。所述计算机可以是通用计算机、专用计算机、计算机网络、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、服务器或者数据中心通过有线(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能够存取的任何可用介质或者是包含一个或多个可以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，DVD)、或者半导体介质(例如固态硬盘(solid state disk，SSD))等。本申请实施例中,计算机可以包括前面所述的装置。
尽管在此结合各实施例对本申请进行了描述，然而，在实施所要求保护的本申请过程中，本领域技术人员通过查看所述附图、公开内容、以及所附权利要求书，可理解并实现所述公开实施例的其他变化。在权利要求中，“包括”(comprising)一词不排除其他组成部分或步骤，“一”或“一个”不排除多个的情况。单个处理器或其他单元可以实现权利要求中列举的若干项功能。相互不同的从属权利要求中记载了某些措施，但这并不表示这些措施不能组合起来产生良好的效果。
尽管结合具体特征及其实施例对本申请进行了描述，显而易见的，在不脱离本申请的精神和范围的情况下，可对其进行各种修改和组合。相应地，本说明书和附图仅仅是所附权利要求所界定的本申请的示例性说明，且视为已覆盖本申请范围内的任意和所有修改、变化、组合或等同物。显然，本领域的技术人员可以对本申请进行各种改动和变型而不脱离本申请的精神和范围。这样，倘若本申请的这些修改和变型属于本申请权利要求及其等同技术的范围之内，则本申请也意图包含这些改动和变型在内。

Claims (31)

  1. 一种通信方法，其特征在于，所述方法包括：
    第一核心网设备获取第一多播广播业务MBS会话对应的初始MBS服务质量流标识QFI序列号SN，所述第一MBS会话对应的初始MBS QFI SN用于确定初始COUNT值；
    所述第一核心网设备在第一流程中向网络设备发送所述第一MBS会话对应的初始MBS QFI SN，所述第一流程为向接入网设备发送所述第一MBS会话的第一个数据包之前的流程。
  2. 根据权利要求1所述的方法，其特征在于，所述第一MBS会话对应的初始MBS QFI SN包括：
    所述第一MBS会话的初始MBS QFI SN，和/或，所述第一MBS会话的至少一个QoS流的初始MBS QFI SN。
  3. 根据权利要求1或2所述的方法，其特征在于，所述第一MBS会话对应的初始MBS QFI SN小于或等于第一MBS QFI SN，或者，第一MBS QFI SN减所述第一MBS会话对应的初始MBS QFI SN小于或等于第一数值；
    其中，所述第一MBS QFI SN为所述第一个数据包的预设MBS QFI SN；所述第一数值为小于或等于分组数据汇聚协议PDCP窗口大小的非负整数。
  4. 根据权利要求1-3任一项所述的方法，其特征在于，所述方法还包括：
    所述第一核心网设备向所述接入网设备发送所述第一个数据包，
    所述第一MBS会话对应的初始MBS QFI SN小于或等于所述第一个数据包的MBS QFI SN，或者，所述第一个数据包的MBS QFI SN减所述第一MBS会话对应的初始MBS QFI SN小于或等于第一数值，所述第一数值为小于或等于分组数据汇聚协议PDCP窗口大小的非负整数。
  5. 根据权利要求1-3任一项所述的方法，其特征在于，所述第一流程为共享传输通道建立流程，所述共享传输通道建立流程用于为所述第一MBS会话建立共享传输通道，所述共享传输通道用于核心网和接入网之间的数据传输。
  6. 根据权利要求5所述的方法，其特征在于，所述第一核心网设备向所述网络设备发送所述第一MBS会话对应的初始MBS QFI SN，包括：
    所述第一核心网设备向所述网络设备发送第一消息，所述第一消息包括所述第一MBS会话对应的初始MBS QFI SN，所述第一消息用于承载所述共享传输通道的地址信息，和/或，所述第一MBS会话的状态信息。
  7. 根据权利要求1-3任一项所述的方法，其特征在于，所述第一流程为PDU会话建立流程或PDU会话修改流程，所述PDU会话建立流程用于建立或修改所述第一MBS会话，所述PDU会话修改流程用于建立或修改所述第一MBS会话。
  8. 根据权利要求1-3任一项所述的方法，其特征在于，所述第一流程为MBS会话更新流程，所述MBS会话更新流程用于在所述第一MBS会话中添加QoS流。
  9. 根据权利要求1-3任一项所述的方法，其特征在于，所述第一流程为组播会话激活流程，所述组播会话激活流程用于激活所述第一MBS会话。
  10. 根据权利要求7-9任一项所述的方法，其特征在于，所述第一核心网设备向所述网络设备发送所述第一MBS会话对应的初始MBS QFI SN，包括：
    所述第一核心网设备向所述网络设备发送第二消息，所述第二消息包括所述第一MBS会话对应的初始MBS QFI SN，所述第二消息用于承载所述第一MBS会话的标识。
  11. 根据权利要求1-10任一项所述的方法，其特征在于，所述方法还包括：
    所述第一核心网设备向所述网络设备发送第一信息，所述第一信息指示去激活所述第一MBS会话后再激活所述第一MBS会话时，所述第一MBS会话对应的MBS QFI SN是否连续或重置。
  12. 根据权利要求11所述的方法，其特征在于，所述第一核心网设备向所述网络设备发送所述第一信息，包括：所述第一核心网设备向所述网络设备发送第三消息，所述第三消息包括所述第一信息；其中：
    所述第三消息用于请求建立或修改所述第一MBS会话；或者，
    所述第三消息用于去激活所述第一MBS会话；或者，
    所述第三消息用于激活所述第一MBS会话；或者，
    所述第三消息用于更新所述第一MBS会话；或者，
    所述第三消息用于建立所述第一MBS会话的共享传输通道。
  13. 根据权利要求1-3、5-10任一项所述的方法，其特征在于，所述第一核心网设备获取第一MBS会 话对应的初始MBS QFI SN，包括：
    所述第一核心网设备接收来自第二核心网设备的所述第一MBS会话对应的初始MBS QFI SN。
  14. 根据权利要求13所述的方法，其特征在于，所述方法还包括：
    所述第一核心网设备向所述第二核心网设备发送第二信息，所述第二信息用于请求所述第一MBS会话对应的初始MBS QFI SN。
  15. 根据权利要求13所述的方法，其特征在于，所述方法还包括：
    所述第一核心网设备向所述第二核心网设备发送第四消息，所述第四消息用于请求建立或修改包转发控制协议PFCP会话；
    所述第一核心网设备接收来自第二核心网设备的所述第一MBS会话对应的初始MBS QFI SN，包括：
    所述第一核心网设备接收来自所述第二核心网设备的第五消息，所述第五消息包括所述第一MBS会话对应的初始MBS QFI SN，所述第五消息为所述第四消息的响应消息。
  16. 根据权利要求1-3、5-10任一项所述的方法，其特征在于，所述第一核心网设备获取第一MBS会话对应的初始MBS QFI SN，包括：
    所述第一核心网设备接收来自第二核心网设备的第一MBS QFI SN，所述第一MBS QFI SN为所述第一个数据包的预设MBS QFI SN；
    所述第一核心网设备根据所述第一MBS QFI SN确定所述第一MBS会话对应的初始MBS QFI SN。
  17. 根据权利要求1-3、5-10任一项所述的方法，其特征在于，所述方法还包括：
    所述第一核心网设备向第二核心网设备发送所述第一MBS会话对应的初始MBS QFI SN或第一MBS QFI SN，所述第一MBS QFI SN为所述第一个数据包的预设MBS QFI SN。
  18. 根据权利要求17所述的方法，其特征在于，所述第一核心网设备向第二核心网设备发送所述第一MBS会话对应的初始MBS QFI SN或第一MBS QFI SN，包括：
    所述第一核心网设备向所述第二核心网设备发送第四消息，所述第四消息用于请求建立或修改PFCP会话，所述第四消息包括所述第一MBS会话对应的初始MBS QFI SN或第一MBS QFI SN；
    所述方法还包括：
    所述第一核心网设备接收来自所述第二核心网设备的第五消息，所述第五消息为所述第四消息的响应消息；
    所述第五消息指示所述PFCP会话建立或修改成功时，指示所述第二核心网设备接受所述第一MBS会话对应的初始MBS QFI SN或所述第一MBS QFI SN。
  19. 根据权利要求1-12任一项所述的方法，其特征在于，所述第一核心网设备确定所述第一MBS会话对应的初始MBS QFI SN，包括：
    所述第一核心网设备接收来自第二核心网设备的第二信息，所述第二信息用于请求所述第一MBS会话对应的初始MBS QFI SN；
    所述第一核心网设备根据所述第二信息，确定所述第一MBS会话对应的初始MBS QFI SN。
  20. 根据权利要求1-12任一项所述的方法，其特征在于，所述第一核心网设备确定所述第一MBS会话对应的初始MBS QFI SN，包括：
    所述第一核心网设备接收来自第二核心网设备的第四消息，所述第四消息用于请求建立或修改PFCP会话；
    所述第一核心网设备根据所述第四消息，确定所述第一MBS会话对应的初始MBS QFI SN。
  21. 一种通信方法，其特征在于，所述方法包括：
    接入网设备在第一流程中接收来自会话管理网元的第一多播广播业务MBS会话对应的初始MBS服务质量流标识QFI序列号SN，所述第一流程为接收所述第一MBS会话的第一个数据包之前的流程；
    所述接入网设备根据所述第一MBS会话对应的初始MBS QFI SN确定初始COUNT值；
    所述接入网设备向终端设备发送所述初始COUNT值。
  22. 根据权利要求21所述的方法，其特征在于，所述第一流程为共享传输通道建立流程，所述共享传输通道建立流程用于为所述第一MBS会话建立共享传输通道，所述共享传输通道用于核心网和接入网之间的数据传输。
  23. 根据权利要求22所述的方法，其特征在于，所述接入网设备接收来自会话管理网元的所述第一MBS会话对应的初始MBS QFI SN，包括：
    所述接入网设备接收来自所述会话管理网元的第一消息，所述第一消息包括所述第一MBS会话对应 的初始MBS QFI SN，所述第一消息用于承载所述共享传输通道的地址信息，和/或，所述第一MBS会话的状态信息。
  24. 根据权利要求21所述的方法，其特征在于，所述第一流程为PDU会话建立流程或PDU会话修改流程，所述PDU会话建立流程用于建立或修改所述第一MBS会话，所述PDU会话修改流程用于建立或修改所述第一MBS会话。
  25. 根据权利要求21所述的方法，其特征在于，所述第一流程为MBS会话更新流程，所述MBS会话更新流程用于在所述第一MBS会话中添加QoS流。
  26. 根据权利要求21所述的方法，其特征在于，所述第一流程为组播会话激活流程，所述组播会话激活流程用于激活所述第一MBS会话。
  27. 根据权利要求24-26任一项所述的方法，其特征在于，所述接入网设备接收来自会话管理网元的所述第一MBS会话对应的初始MBS QFI SN，包括：
    所述接入网设备接收来自所述会话管理网元的第二消息，所述第二消息包括所述第一MBS会话对应的初始MBS QFI SN，所述第二消息用于承载所述第一MBS会话的标识。
  28. 根据权利要求1-27任一项所述的方法，其特征在于，所述初始COUNT值为状态变量RX_DELIV的初始值。
  29. 一种通信装置，其特征在于，所述通信装置包括处理器；所述处理器，用于运行计算机程序或指令，以使所述通信装置执行如权利要求1-20任一项所述的方法，或者，以使所述通信装置执行如权利要求21-28任一项所述的方法。
  30. 一种计算机可读存储介质，其特征在于，计算机可读存储介质存储有计算机指令或程序，当计算机指令或程序在计算机上运行时，使得如权利要求1-20任一项所述的方法被执行，或者，使得如权利要求21-28任一项所述的方法被执行。
  31. 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；当部分或全部所述计算机指令在计算机上运行时，使得如权利要求1-20任一项所述的方法被执行，或者，使得如权利要求21-28任一项所述的方法被执行。
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20210104562A (ko) * 2020-02-14 2021-08-25 주식회사 케이티 Mbs 데이터를 처리하는 방법 및 그 장치
WO2021213305A1 (zh) * 2020-04-24 2021-10-28 华为技术有限公司 通信方法及装置
WO2022082680A1 (zh) * 2020-10-22 2022-04-28 华为技术有限公司 一种通信方法及装置
WO2022085664A1 (ja) * 2020-10-21 2022-04-28 シャープ株式会社 端末装置、基地局装置、および方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20210104562A (ko) * 2020-02-14 2021-08-25 주식회사 케이티 Mbs 데이터를 처리하는 방법 및 그 장치
WO2021213305A1 (zh) * 2020-04-24 2021-10-28 华为技术有限公司 通信方法及装置
WO2022085664A1 (ja) * 2020-10-21 2022-04-28 シャープ株式会社 端末装置、基地局装置、および方法
WO2022082680A1 (zh) * 2020-10-22 2022-04-28 华为技术有限公司 一种通信方法及装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
CATT: "TP on TS 38.300 on MBS service continuity", 3GPP DRAFT; R3-210315, 3RD GENERATION PARTNERSHIP PROJECT (3GPP), MOBILE COMPETENCE CENTRE ; 650, ROUTE DES LUCIOLES ; F-06921 SOPHIA-ANTIPOLIS CEDEX ; FRANCE, vol. RAN WG3, no. E-meeting; 20210125 - 20210204, 15 January 2021 (2021-01-15), Mobile Competence Centre ; 650, route des Lucioles ; F-06921 Sophia-Antipolis Cedex ; France , XP051975048 *

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