A communication method and apparatus for multicast / broadcast services

Abstract

This application provides a communication method and apparatus for multicast / broadcast services. The method includes: a network device acquiring reference location information of a terminal, the reference location information being used to characterize the reference location of the terminal; when the reference location of the terminal is within the service area of ​​a first multicast / broadcast service, the network device triggers a target access network device of the terminal to allocate or establish data resources for transmitting the first multicast / broadcast service for the terminal; when the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service, the network device triggers the target access network device of the terminal not to allocate or establish data resources for transmitting the first multicast / broadcast service for the terminal. The method provided in this application, through session management of regional multicast / broadcast services, can ensure dynamic and flexible interaction between core network elements and access network devices when a terminal moves into or out of the service area, effectively saving network resources.

Description

[0001] This application claims priority to PCT application filed on February 10, 2021, application number PCT / CN2021 / 076441, entitled "A Communication Method and Apparatus for Multicast / Broadcast Services", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communication technology, and in particular to a communication method and apparatus for multicast / broadcast services. Background Technology

[0003] With the development of mobile internet, mobile high-definition video services have experienced explosive growth. Users are gradually shifting from watching video programs through fixed networks to watching them through mobile devices and mobile networks, making the impact of video services on mobile networks increasingly severe.

[0004] To overcome the above difficulties, supporting multicast / broadcast service (5MBS) functionality on the basis of the 5th generation (5G) mobile communication network architecture has become a key research topic.

[0005] One key research issue in the 5MBS research project is Local MBS, which refers to multicast / broadcast services that are only broadcast within a designated area. This designated area can be called the broadcasting area, service area, or distribution area. Specifically, the broadcasting area can be a cell or a tracking area (TA), etc.

[0006] To address the aforementioned research questions, how to manage multicast / broadcast sessions effectively to save network resources when terminals move into or out of the multicast / broadcast service area is an urgent problem to be solved. Summary of the Invention

[0007] This application provides a communication method for multicast / broadcast services, which enables network devices to dynamically determine the relationship between the reference location information of a terminal and the service area of ​​a first multicast / broadcast service, flexibly allocate or delete resources for the terminal, improve the utilization efficiency of network resources, effectively save network resources, and avoid resource waste caused by invalid forwarding of multicast / broadcast service data.

[0008] In a first aspect, a communication method for a multicast / broadcast service is provided. The method includes: a network device acquiring reference location information of a terminal, the reference location information being used to characterize the reference location of the terminal; when the reference location of the terminal is located within the service area of ​​a first multicast / broadcast service, the network device triggering a target access network device of the terminal to allocate transmission resources for the terminal, the transmission resources being used to transmit data of the first multicast / broadcast service.

[0009] In conjunction with the first aspect, in some implementations of the first aspect, the reference location information includes the location information of the terminal under the target access network device of the terminal.

[0010] In conjunction with the first aspect, in some implementations of the first aspect, the location information is the identifier of the target cell of the terminal and / or the identifier of the target access network device.

[0011] In conjunction with the first aspect, in some implementations of the first aspect, the network device includes a session management function network element or the source access network device of the terminal.

[0012] The communication method for multicast / broadcast services provided in this application dynamically determines the reference location information of the terminal through network equipment. When the terminal is in the service area of ​​the first multicast / broadcast service, it triggers the T-gNB of the terminal to allocate or establish resources for the terminal, thereby improving the utilization efficiency of network resources.

[0013] In a second aspect, a communication method for a multicast / broadcast service is provided. The method includes: a network device acquiring reference location information of a terminal, the reference location information being used to characterize the reference location of the terminal; when the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service, the network device initiating the deletion of a first transmission resource of the terminal, the first transmission resource being used to transmit data of the first multicast / broadcast service.

[0014] It should be noted that the network device can initiate the release of the terminal's first transmission resource, or the network device can trigger the deletion, initiate the deletion, or trigger the deletion of the first transmission resource.

[0015] The communication method for multicast / broadcast services provided in this application, when the network device determines that the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service, triggers / initiates the release of the first transmission resources for deleting the terminal, which can effectively save network resources and avoid resource waste caused by invalid forwarding.

[0016] In conjunction with the second aspect, in some implementations of the second aspect, the first transmission resource includes: resources for the terminal to transmit data of the first multicast / broadcast service through the terminal's target access network equipment.

[0017] In conjunction with the second aspect, in some implementations of the second aspect, the network device determines, based on the reference location information, that the terminal is located outside the service area of ​​the first multicast / broadcast service.

[0018] In conjunction with the second aspect, in some implementations of the second aspect, the reference location information includes: the location information of the terminal under the access network device currently providing services to the terminal, or the location information of the terminal under the target access network device of the terminal.

[0019] In conjunction with the second aspect, in some implementations of the second aspect, the network device obtains the reference location information of the terminal by: when the network device is a session management function network element, the session management function network element receives a first message, the first message including the reference location information.

[0020] In conjunction with the second aspect, in some implementations of the second aspect, the first message also includes identification information of the first multicast / broadcast service.

[0021] In conjunction with the second aspect, in some implementations of the second aspect, the first message is either a Protocol Data Unit (PDU) session context update request or a location information provision.

[0022] In conjunction with the second aspect, in some implementations of the second aspect, the method further includes: the session management function network element subscribing to the reference location information of the terminal from the access and mobility management network element; the session management function network element receiving a first message, including: the session management function network element receiving the reference location information of the terminal from the access and mobility management network element.

[0023] In conjunction with the second aspect, in certain implementations of the second aspect, the network device initiating the release of the first transmission resource includes: when the network device is a session management function (PMF) network element, the PMF network element notifies the user plane function (UPF) network element to release / delete the first transmission resource, and / or, the PMF network element notifies the target access network device of the terminal to release the first transmission resource. Specifically, when the first transmission resource is a radio bearer corresponding to a QoS flow corresponding to a first multicast / broadcast service, when the PMF network element only notifies the target access network device of the terminal to release the first transmission resource, it can be understood as terminating the first transmission resource. When the first transmission resource is a QoS flow corresponding to a first multicast / broadcast service, when the PMF network element notifies both the user plane function (UPF) network element and the target access network device of the terminal to release the first transmission resource, it can be understood as releasing the first transmission resource.

[0024] In conjunction with the second aspect, in some implementations of the second aspect, the session management function network element notifies the UPF to release the first transmission resource, including: the session management function network element sends an N4 session modification request or a Message Forwarding Control Protocol (PFCP) session modification request to the UPF to notify the UPF to release the first transmission resource.

[0025] The multicast / broadcast service communication method provided in this application, if the session management function network element determines that the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service, the session management function network element notifies the release of transmission resources for the multicast / broadcast service in the PFCP session context during interaction with the UPF. Through the processing and operation of the session management function network element, this scheme can effectively save network resources and avoid resource waste caused by invalid forwarding of multicast / broadcast service data.

[0026] In conjunction with the second aspect, in some implementations of the second aspect, the method further includes: when the network device is a session management function network element, the session management function network element notifies the target access network device of the terminal that the first transmission resource is invalid; or, the session management function network element notifies the target access network device of the terminal not to establish / prepare / allocate the radio resource corresponding to the first transmission resource; or, the session management function network element does not send the identifier of the first transmission resource to the target access network device of the terminal.

[0027] It should be noted that the session management function network element notifying the target access network device of the terminal not to allocate the radio resource corresponding to the first transmission resource can also mean that the session management function network element notifying the target access network device of the terminal not to establish or prepare the radio resource corresponding to the first transmission resource.

[0028] The communication method for multicast / broadcast services provided in this application, if the session management function network element determines that the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service, the session management function network element notifies the target access network device of the terminal not to allocate / establish / prepare transmission resources for the data of the first multicast / broadcast service. Through the processing and operation of the session management function network element, this scheme can effectively save network resources and avoid the waste of resources caused by invalid forwarding of multicast / broadcast service data.

[0029] In conjunction with the second aspect, in some implementations of the second aspect, the network device initiates the release of the terminal's first transmission resource, including: when the network device is the source access network device of the terminal, the source access network device notifies the session management function network element to release the first transmission resource.

[0030] The communication method for multicast / broadcast services provided in this application, if the source access network device of the terminal determines that the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service, the source access network device of the terminal notifies the session management function network element to release and delete the first transmission resource used to transmit the data of the first multicast / broadcast service. Through the processing and operation of the source base station, this scheme can effectively save network resources and avoid the waste of resources caused by invalid forwarding of multicast / broadcast service data.

[0031] Thirdly, a communication method for multicast / broadcast services is provided, the method comprising: a target access network device acquiring reference location information of a terminal, the reference location information being used to characterize the reference location of the terminal; when the reference location of the terminal is outside the service area of ​​a first multicast / broadcast service, the target access network device not accepting / discarding forwarding of data from the source access network device for the terminal for the first multicast / broadcast service.

[0032] The multicast / broadcast service communication method provided in this application determines and processes the target access network device. When the target access network device determines that the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service, the target access network device does not forward the data of the first multicast / broadcast service of the terminal. This scheme can effectively save network resources and avoid the waste of resources caused by invalid forwarding of multicast / broadcast service data.

[0033] In conjunction with the third aspect, in some implementations of the third aspect, the target access network device obtains the reference location information of the terminal, including: the target access network device receiving the reference location information of the terminal from the source access network device.

[0034] In conjunction with the third aspect, in some implementations of the third aspect, the reference location information includes: the location information of the terminal under the target access network device of the terminal.

[0035] In conjunction with the third aspect, in some implementations of the third aspect, the method further includes: notifying the source access network device that the target access network device does not accept the forwarding of the data of the first multicast / broadcast service for the terminal by the source access network device.

[0036] Fourthly, a communication method for multicast / broadcast services is provided, the method comprising: a source access network device discovering a terminal device joining a first multicast / broadcast service, the source access network device sending identification information of a target cell, the identification information of the target cell being carried in N2 session management information (N2 SM Information).

[0037] It should be understood that when the source access network device discovers that the terminal device has joined the first multicast / broadcast service, it can also be understood as the source access network device determining that the terminal device has joined the first multicast / broadcast service.

[0038] It should be noted that the target cell identification information can be carried in a separate information element alongside the N2 session management information in a specific message. This specific message can be a handover required message. It is understood that the target cell identification information is not carried in the N2 session management information, but rather as a separate information element in the handover required message. The information element parallel to the N2 session management information can be, in addition to the information elements included in existing handover required messages: handover type, target ID, cause value, source to target transport container, PDU session resource list, message type, AMF new generation application protocol UE ID (NGAP UE ID), and RAN UE NGAP ID, the target cell identification information is added as an additional information element parallel to the aforementioned information elements included in existing handover required messages. For example, in addition to the information elements included in the existing technology handover requirements—handover type, target ID, cause value, source-to-target transport container, PDU session resource list, message type, AMF UE NGAP ID, and RAN UE NGAP ID—the target cell identification information can be added as an extra information element and not carried in any of the information elements included in the existing technology handover requirements. Instead, it can be carried as a separate information element in the handover requirements.

[0039] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the method further includes: the source access network device receiving a measurement report from the terminal device, and the source access network device determining the identification information of the target cell of the terminal device based on the measurement report.

[0040] It should be noted that the source access network device can also determine the identification information of the target cell of the terminal device based on the load.

[0041] For example, in one feasible approach, when the load on the source access network device is too high, such as when the number of terminal devices connected to the source access network device is large, the source access network device will autonomously select a portion of the terminal devices and actively choose the target cell to which they need to hand over. This portion of terminal devices autonomously selected by the source access network device may include terminal devices that have joined the first multicast / broadcast service. In this case, the source access network device can use the neighboring cell identifiers contained in its stored neighboring base stations as the identifier of the target cell selected by the terminal device, and carry this identifier in the N2 session management information, sending it to the SMF via the AMF. The neighboring cell identifiers of the neighboring base stations stored by the source access network device can be obtained by exchanging parameters with neighboring access network devices during source access network device initialization or power-on; or, they can be obtained through operation, administration, and maintenance (OAM) configuration. The neighboring base stations can be one or more, the neighboring cells contained in the neighboring base stations can be one or more, and the autonomously selected portion of terminal devices can be one or more.

[0042] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the N2 session management information is carried within the handover required information. For example, the N2 session management information is a handover required transfer.

[0043] Fifthly, a communication method for multicast / broadcast services is provided. The method includes: a source access network device acquiring reference location information of a terminal device, the reference location information being used to characterize the reference location of the terminal device; the source access network device sending indication information to a session management function network element based on the reference location information, the indication information including first indication information and / or second indication information, wherein the first indication information is used to indicate that the reference location of the terminal device is outside the service area of ​​a first multicast / broadcast service, and the second indication information is used to indicate that the reference location of the terminal device is within the service area of ​​a second multicast / broadcast service.

[0044] In conjunction with the fifth aspect, in some implementations of the fifth aspect, the reference location information includes: the location information of the terminal device under the target access network device, specifically the identifier of the target cell of the terminal device.

[0045] In conjunction with the fifth aspect, in some implementations of the fifth aspect, this instruction information is carried in the N2 session management information.

[0046] In conjunction with the fifth aspect, in some implementations of the fifth aspect, this indication information is a data element parallel to the N2 session management information. The parallel data elements are explained as described in the fourth aspect, and will not be repeated here.

[0047] In conjunction with the fifth aspect, in some implementations of the fifth aspect, the N2 session management information is carried in the handover requirement, and the N2 session management information is transmitted as a handover required transfer.

[0048] A sixth aspect provides a communication method for multicast / broadcast services, the method comprising: a session management function network element receiving first indication information, the first indication information being used to indicate that the reference location of a terminal device is outside the service area of ​​a first multicast / broadcast service; the session management function network element initiating the release of a first transmission resource of the terminal device according to the first indication information, the first transmission resource being used to transmit data of the first multicast / broadcast service.

[0049] In conjunction with the sixth aspect, in some implementations of the sixth aspect, the method further includes: the session management function network element receiving second indication information, the second indication information being used to indicate that the reference location of the terminal device is within the service area of ​​the second multicast / broadcast service; the session management function network element, based on the second indication information, initiating the target access network device of the terminal device to configure second transmission resources for the terminal device, the second transmission resources being used to transmit data of the second multicast / broadcast service.

[0050] In conjunction with the sixth aspect, in some implementations of the sixth aspect, the first instruction information and the second instruction information are carried in the N2 session management information.

[0051] In conjunction with the sixth aspect, in some implementations of the sixth aspect, the first indication information and the second indication information are information elements listed alongside the N2 session management information. The listed information elements are explained as described in the fourth aspect, and will not be repeated here.

[0052] In conjunction with the sixth aspect, in some implementations of the sixth aspect, the method further includes: the N2 session management information is carried in the handover requirement, and the N2 session management information is transmitted as a handover required transfer.

[0053] A seventh aspect provides a communication method for multicast / broadcast services, the method comprising: a session management function network element receiving indication information, the indication information being used to indicate that the reference location of the terminal device is within the service area of ​​a first multicast / broadcast service; the session management function network element initiating, according to the indication information, a target access network device of the terminal device to configure a first transmission resource for the terminal device, the first transmission resource being used to transmit data of the first multicast / broadcast service.

[0054] In conjunction with the seventh aspect, in some implementations of the seventh aspect, the instruction information is carried in the N2 session management information.

[0055] In conjunction with the seventh aspect, in some implementations of the seventh aspect, the N2 session management information is carried in the handover requirements, and the N2 session management information is transmitted for the handover requirements.

[0056] In conjunction with the seventh aspect, in some implementations of the seventh aspect, this indication information is a data element parallel to the N2 session management information. The parallel data elements are explained as described in the fourth aspect, and will not be repeated here.

[0057] Based on the above scheme, the processing logic of the session management function network element is freed up, because it is determined by the source access network device whether the target cell is outside the service area of ​​the first multicast / broadcast service and / or within the service area of ​​the second multicast / broadcast service, and then the determination result is communicated to the session management function network element in an indicative manner. Specifically, for example, when it is determined that the target cell identifier is outside the first multicast / broadcast service, the N2 session management information includes the identifier information of the first multicast / broadcast service and the first indication information, which can be represented by binary bits 1 or 0, for example. As another example, when it is determined that the target cell identifier is within the second multicast / broadcast service, the N2 session management information includes the second indication information and the identifier information of the second multicast / broadcast service, which can also be represented by binary bits 1 or 0, for example.

[0058] Eighthly, a communication method for a multicast / broadcast service is provided, the method comprising: a target access network device receiving a notification from a session management function network element, the notification being used to notify the terminal that a first transmission resource is invalid, the first transmission resource being used to transmit data for a first multicast / broadcast service; the target access network device not allocating radio resources corresponding to the first transmission resource; and / or, the target access network device sending indication information to a source access network device of the terminal, the indication information being used to instruct the target access network device not to accept the forwarding of the data for the first multicast / broadcast service of the terminal by the source access network device.

[0059] The communication method for multicast / broadcast services provided in this application is processed and operated through the target access network equipment. This solution can effectively save network resources and avoid resource waste caused by invalid forwarding of multicast / broadcast service data.

[0060] A ninth aspect provides a communication apparatus for a multicast / broadcast service, the apparatus comprising: a processing module configured to acquire reference location information of a terminal, the reference location information being used to characterize the reference location of the terminal; when the reference location of the terminal is located within the service area of ​​a first multicast / broadcast service, the processing module triggers a target access network device of the terminal to allocate transmission resources for the terminal, the transmission resources being used to transmit data of the first multicast / broadcast service.

[0061] Based on the beneficial effects of the above-mentioned solution, please refer to the corresponding description in the first aspect. For the sake of brevity, this application will not repeat it here.

[0062] In conjunction with aspect nine, in some implementations of aspect nine, the reference location information includes the location information of the terminal under the target access network device of the terminal.

[0063] In conjunction with the ninth aspect, in some implementations of the ninth aspect, the location information is the identifier of the target cell of the terminal and / or the identifier of the target access network device.

[0064] In conjunction with the ninth aspect, in some implementations of the ninth aspect, the apparatus includes: a session management function network element or a source access network device of the terminal.

[0065] Tenthly, a communication apparatus for multicast / broadcast services is provided, the apparatus comprising:

[0066] The processing module is used to obtain the reference location information of the terminal, which is used to characterize the reference location of the terminal; when the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service, the processing module triggers the release of the first transmission resource of the terminal, which is used to transmit the data of the first multicast / broadcast service.

[0067] Based on the beneficial effects of the above-mentioned solution, please refer to the corresponding description in the second aspect. For the sake of brevity, this application will not repeat it here.

[0068] In conjunction with the tenth aspect, in some implementations of the tenth aspect, the first transmission resource includes: resources for transmitting data of the first multicast / broadcast service through the target access network device of the terminal.

[0069] In conjunction with the tenth aspect, in some implementations of the tenth aspect, the apparatus further includes: the processing module, which is further configured to determine, based on the reference location information, that the terminal is located outside the service area of ​​the first multicast / broadcast service.

[0070] In conjunction with the tenth aspect, in some implementations of the tenth aspect, the reference location information includes: the location information of the terminal under the access network device currently providing services to the terminal; or, the location information of the terminal under the target access network device of the terminal.

[0071] In conjunction with aspect ten, in some implementations of aspect ten, when the device is a session management function network element, the device further includes: a transceiver module for receiving a first message, the first message including the reference location information.

[0072] In conjunction with aspect ten, in some implementations of aspect ten, the first message also includes identification information of the first multicast / broadcast service.

[0073] In conjunction with aspect ten, in some implementations of aspect ten, the first message is either a Protocol Data Unit (PDU) session context update request or location information provision.

[0074] In conjunction with the tenth aspect, in some implementations of the tenth aspect, the apparatus further includes: the transceiver module, which is further configured to subscribe to the reference location information of the terminal from the access and mobility management network element; the transceiver module receiving a first message, including: the transceiver module receiving the reference location information of the terminal from the access and mobility management network element.

[0075] In conjunction with the tenth aspect, in some implementations of the tenth aspect, the transceiver module is further configured to notify the user plane function network element (UPF) to release the first transmission resource when the device is a session management function network element, and / or the transceiver module is further configured to notify the target access network device of the terminal to release the first transmission resource.

[0076] In conjunction with aspect ten, in some implementations of aspect ten, the transceiver module is also used to send an N4 session modification request or a Message Forwarding Control Protocol (PFCP) session modification request to the UPF to notify the UPF to release the first transmission resource.

[0077] In conjunction with the tenth aspect, in some implementations of the tenth aspect, the apparatus further includes: when the apparatus is a session management function network element, the transceiver module notifies the target access network device of the terminal that the first transmission resource is invalid, or the transceiver module notifies the target access network device of the terminal not to allocate radio resources corresponding to the first transmission resource, or the transceiver module not to send the identifier of the first transmission resource to the target access network device of the terminal.

[0078] In conjunction with the tenth aspect, in some implementations of the tenth aspect, when the device is the source access network device of the terminal, the device further includes: a transceiver module for notifying the session management function network element to delete / release the first transmission resource.

[0079] Eleventhly, a communication apparatus for multicast / broadcast services is provided. The apparatus includes: a processing module, configured to acquire reference location information of a terminal, the reference location information being used to characterize the reference location of the terminal; when the reference location of the terminal is outside the service area of ​​a first multicast / broadcast service, the processing module does not accept forwarding of data from the source access network device of the terminal for the first multicast / broadcast service.

[0080] Based on the beneficial effects of the above-mentioned scheme, please refer to the corresponding description in the third aspect. For the sake of brevity, this application will not repeat it here.

[0081] In conjunction with the eleventh aspect, in some implementations of the eleventh aspect, the transceiver module is used to receive reference location information of the terminal from the source access network device.

[0082] In conjunction with the eleventh aspect, in some implementations of the eleventh aspect, the reference location information includes: the location information of the terminal under the target access network device of the terminal.

[0083] In conjunction with the eleventh aspect, in some implementations of the eleventh aspect, the transceiver module is further configured to notify the source access network device that the device does not accept the forwarding of the data of the first multicast / broadcast service for the terminal by the source access network device.

[0084] In a twelfth aspect, a communication apparatus for a multicast / broadcast service is provided, the apparatus comprising: a transceiver module configured to receive a notification from a session management function network element, the notification being used to notify the terminal that a first transmission resource is invalid, the first transmission resource being used to transmit data for a first multicast / broadcast service; a processing module configured to not allocate radio resources corresponding to the first transmission resource and / or, the transceiver module further configured to send indication information to a source access network device of the terminal, the indication information being used to instruct the transceiver module not to accept the forwarding of the data for the first multicast / broadcast service of the terminal by the source access network device.

[0085] Based on the beneficial effects of the above-mentioned scheme, please refer to the corresponding description in the fourth aspect. For the sake of brevity, this application will not repeat it here.

[0086] In a thirteenth aspect, a communication apparatus for multicast / broadcast services is provided, the apparatus comprising: a memory for storing computer instructions; and a processor for executing the computer instructions stored in the memory, causing the apparatus to perform a communication method for multicast / broadcast services in any of the possible implementations of the first to eighth aspects described above.

[0087] In a fourteenth aspect, a computer-readable storage medium is provided, characterized in that a computer program is stored thereon, which, when executed by a communication device for multicast / broadcast services, causes the device to perform a communication method for multicast / broadcast services in any of the possible implementations of the first to eighth aspects described above. Attached Figure Description

[0088] Figure 1 This is a schematic diagram of a network architecture applicable to an embodiment of this application.

[0089] Figure 2 This is a network architecture for multicast / broadcast services applicable to the embodiments of this application.

[0090] Figure 3 A schematic diagram of the data transmission process in unicast mode is shown.

[0091] Figure 4 A schematic diagram of the data transmission process in multicast / broadcast mode is shown.

[0092] Figure 5 This is an illustrative flow diagram of a multicast / broadcast service communication method 500 provided in an embodiment of this application.

[0093] Figure 6 This is a scenario of multicast / broadcast service provided in the embodiments of this application.

[0094] Figure 7 This is an illustrative flow diagram of a multicast / broadcast service communication method 700 provided in an embodiment of this application.

[0095] Figure 8 This is an illustrative flow of a multicast / broadcast service communication method 800 provided in an embodiment of this application.

[0096] Figure 9 This is an illustrative flow diagram of a multicast / broadcast service communication method 900 provided in an embodiment of this application.

[0097] Figure 10 This is an illustrative flow of a communication method 1000 for multicast / broadcast services provided in an embodiment of this application.

[0098] Figure 11 This is an illustrative flow of a communication method 1100 for multicast / broadcast services provided in an embodiment of this application.

[0099] Figure 12 This is an illustrative flow diagram of a multicast / broadcast service communication method 1200 provided in an embodiment of this application.

[0100] Figure 13This is an illustrative flow diagram of a multicast / broadcast service communication method 1300 provided in an embodiment of this application.

[0101] Figure 14 This is an illustrative flow of a communication method 1400 for multicast / broadcast services provided in an embodiment of this application.

[0102] Figure 15 This is an illustrative flow diagram of a multicast / broadcast service communication method 1500 provided in an embodiment of this application.

[0103] Figure 16 This is an illustrative flow diagram of a multicast / broadcast service communication method 1600 provided in an embodiment of this application.

[0104] Figure 17 This is an illustrative flow diagram of a multicast / broadcast service communication method 1700 provided in an embodiment of this application.

[0105] Figure 18 This is an illustrative flow diagram of a multicast / broadcast service communication method 1800 provided in an embodiment of this application.

[0106] Figure 19 This is an illustrative flow diagram of a multicast / broadcast service communication method 1900 provided in an embodiment of this application.

[0107] Figure 20 This is an illustrative flow diagram of a multicast / broadcast service communication method 2000 provided in an embodiment of this application.

[0108] Figure 21 This is an illustrative flow diagram of a multicast / broadcast service communication method 2100 provided in an embodiment of this application.

[0109] Figure 22 This is an illustrative flow diagram of a multicast / broadcast service communication method 2200 provided in an embodiment of this application.

[0110] Figure 23 This is an illustrative flow diagram of a multicast / broadcast service communication method 2300 provided in an embodiment of this application.

[0111] Figure 24 This illustration shows a schematic block diagram of a communication apparatus for a multicast / broadcast service according to an embodiment of this application.

[0112] Figure 25 This illustration shows a schematic block diagram of a communication apparatus for a multicast / broadcast service according to an embodiment of this application.

[0113] Figure 26 This illustration shows a schematic block diagram of a communication apparatus for a multicast / broadcast service according to an embodiment of this application.

[0114] Figure 27 A schematic architecture diagram of a communication device according to an embodiment of this application is shown. Detailed Implementation

[0115] Figure 1 This is a schematic diagram of a network architecture applicable to an embodiment of this application. The following describes... Figure 1 Each part of the network architecture shown will be explained separately.

[0116] 1. User equipment (terminal) 110: This may include various handheld devices, vehicle-mounted devices, wearable devices, computing devices, or other processing devices connected to a wireless modem with wireless communication capabilities, as well as various forms of terminals, mobile stations (MS), terminals, or soft terminals, etc. For example, water meters, electricity meters, sensors, etc.

[0117] For example, the user equipment in the embodiments of this application may refer to an access terminal, user unit, user station, mobile station, mobile station, relay station, remote station, remote terminal, mobile device, user terminal, terminal equipment, wireless communication equipment, user agent, or user device. The user equipment may also be a cellular phone, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, personal digital assistant (PDA), handheld device with wireless communication function, computing device or other processing device connected to a wireless modem, vehicle-mounted device, wearable device, user equipment in a 5G network, or user equipment in a future evolved public land mobile network (PLMN) or user equipment in a future vehicle-to-everything (V2X) network, etc. The embodiments of this application do not limit this.

[0118] As an example and not a limitation, in this application embodiment, wearable devices can also be called wearable smart devices. This is a general term for devices that utilize wearable technology to intelligently design and develop everyday wearables, such as glasses, gloves, watches, clothing, and shoes. Wearable devices are portable devices that are worn directly on the body or integrated into the user's clothing or accessories. Wearable devices are not merely hardware devices; they achieve powerful functions through software support, data interaction, and cloud interaction. Broadly defined, wearable smart devices include those that are feature-rich, large in size, and can achieve complete or partial functionality without relying on a smartphone, such as smartwatches or smart glasses, as well as those that focus on a specific application function and require use with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0119] Furthermore, in this embodiment, the user equipment can also be a user equipment within an Internet of Things (IoT) system. IoT is a crucial component of future information technology development, its main technical characteristic being the connection of objects to networks via communication technology, thereby achieving intelligent networks that enable human-machine and machine-to-machine interconnection. In this embodiment, IoT technology can achieve massive connectivity, deep coverage, and power saving for terminals through technologies such as narrowband (NB). Additionally, in this embodiment, the user equipment can also include sensors such as smart printers, train detectors, and gas station sensors, whose main functions include collecting data (in some user equipment), receiving control information and downlink data from access network devices, and transmitting uplink data to access network devices by sending electromagnetic waves.

[0120] 2. Radio access network (R)AN equipment 120: used to provide network access functionality for authorized user equipment in a specific area, and to use transmission tunnels of different quality according to the user equipment level, service requirements, etc.

[0121] (R)AN equipment, or RAN for short, is used to manage radio resources, provide access services for user equipment, and then forward control signals and user equipment data between user equipment and the core network. (R)AN can also be understood as a base station in a traditional network.

[0122] For example, the access network device in this application embodiment can be any communication device with wireless transceiver function for communicating with user equipment. The access network equipment includes, but is not limited to: evolved NodeB (eNB), radio network controller (RNC), Node B (NB), base station controller (BSC), base transceiver station (BTS), home evolved NodeB (HeNB, or home Node B, HNB), baseband unit (BBU), access point (AP), wireless relay node, wireless backhaul node, transmission point (TP), or transmission and reception point (TRP) in a wireless fidelity (WIFI) system. It can also be a gNB in ​​a 5G system, such as NR, or a transmission point (TRP or TP), one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system, or a network node constituting a gNB or transmission point, such as a baseband unit (BBU) or a distributed unit (DU).

[0123] In some deployments, a gNB may include a centralized unit (CU) and a distribution unit (DU). The gNB may also include an active antenna unit (AAU). The CU implements some of the gNB's functions, and the DU implements others. For example, the CU handles non-real-time protocols and services, implementing radio resource control (RRC) and packet data convergence protocol (PDCP) layer functions. The DU handles physical layer protocols and real-time services, implementing radio link control (RLC), media access control (MAC), and physical (PHY) layer functions. The AAU implements some physical layer processing functions, radio frequency processing, and active antenna-related functions. Since RRC layer information ultimately becomes PHY layer information, or is derived from PHY layer information, in this architecture, higher-layer signaling, such as RRC layer signaling, can be considered to be sent by the DU, or by the DU+AAU. It is understood that access network equipment can be devices including one or more of the following: CU nodes, DU nodes, and AAU nodes. In addition, the CU can be classified as an access network device in the radio access network (RAN) or as an access network device in the core network (CN), and this application does not limit this.

[0124] 3. User plane network element 130: Used for routing and forwarding user plane data, or processing the quality of service (QoS) of user plane data.

[0125] In 5G communication systems, this user plane network element can be a user plane function (UPF) network element. In future communication systems, the user plane network element can still be a UPF network element, or it can have other names; this application does not limit this.

[0126] 4. Data network element (DN) 140: A network used to provide data transmission.

[0127] In 5G communication systems, this data network element can be a data network element. In future communication systems, the data network element can still be a DN element, or it can have other names; this application does not limit this.

[0128] 5. Access Management Network Element 150: Mainly used for mobility management and access management, it can be used to implement other functions of the 4G communication system's mobility management entity (MME) except for session management.

[0129] In 5G communication systems, the access management network element can be an access and mobility management function (AMF) network element. In future communication systems, the access management network element can still be an AMF network element, or it can have other names; this application does not limit this.

[0130] 6. Session Management Element 160: Primarily used for session management, allocation and management of Internet Protocol (IP) addresses for terminals, selection of endpoints for manageable user plane functions, policy control and charging function interfaces, and downlink data notification.

[0131] In 5G communication systems, the session management function network element can be a session management function (SMF) network element. In future communication systems, the session management function network element can still be an SMF network element, or it can have other names; this application does not limit this.

[0132] 7. Policy control network element 170: Used to provide policy rule information, etc. For example, it provides policy rules for control plane function network elements (such as AMF, SMF, etc.).

[0133] In 4G communication systems, this policy control network element can be a policy and charging rules function (PCRF) network element. In 5G communication systems, this policy control network element can be a policy control function (PCF) network element. In future communication systems, the policy control network element can still be a PCF network element, or it can have other names; this application does not limit this.

[0134] 8. Network Slice Selection Element 180: Used to find the PCF associated with the session.

[0135] In 5G communication systems, the network slice selection element can be a network slice selection function (NSSF) element. In future communication systems, the network slice selection element can still be an NSSF element, or it can have other names; this application does not limit this.

[0136] 9. Authentication Server 190: Used for authentication services, generates keys to achieve two-way authentication of terminals, and supports a unified authentication framework.

[0137] In 5G communication systems, the authentication server can be an authentication server function (AUSF) network element. In future communication systems, the authentication server function network element can still be an AUSF network element, or it can have other names; this application does not limit this.

[0138] 10. Data Management Network Element 1100: Used for processing terminal identification, access authentication, registration, and mobility management, etc.

[0139] In 5G communication systems, this data management network element can be a unified data management (UDM) network element. In future communication systems, the unified data management network element can still be a UDM network element, or it can have other names; this application does not limit this.

[0140] 11. Application network elements: Used for data routing affected by applications, accessing network open function network elements, and interacting with the policy framework for policy control, etc.

[0141] In 5G communication systems, this application network element can be an application function (AF) network element. In future communication systems, the application network element can still be an AF network element, or it can have other names; this application does not limit this.

[0142] 12. Network storage element: Used to maintain real-time information of all network function services in the network.

[0143] In 5G communication systems, this network storage element can be a network repository function (NRF) element. In future communication systems, the network storage element can still be an NRF element, or it can have other names; this application does not limit its scope.

[0144] It is understood that the aforementioned network elements or functions can be network components in hardware devices, software functions running on dedicated hardware, or virtualization functions instantiated on a platform (e.g., a cloud platform).

[0145] Of course, Figure 1The network architecture involved may also include other network elements, such as unified data repository (UDR) or network repository function (NRF), etc., without specific limitations.

[0146] exist Figure 1 In the network architecture shown, the terminal connects to the AMF via the N1 interface, the RAN connects to the AMF via the N2 interface, and the RAN connects to the UPF via the N3 interface.

[0147] UPFs are connected to each other via the N9 interface, and UPFs are interconnected with DNs via the N6 interface.

[0148] The session management function network element controls the UPF through the N4 interface. The AMF interfaces with the session management function network element through the N11 interface.

[0149] AMF obtains terminal subscription data from the UDM network element via the N8 interface; the session management function network element obtains terminal subscription data from the UDM network element via the N10 interface.

[0150] AMF obtains policy data from PCF through the N15 interface; the session management function network element obtains policy data from PCF through the N7 interface.

[0151] The AF and PCF are connected via the N5 interface.

[0152] It should be noted that, Figure 1 The names of the various network elements and communication interfaces involved are given as examples based on current protocols, but this does not limit the embodiments of this application to only known communication systems. Therefore, the standard names that appear when describing the current protocols are functional descriptions. This application does not limit the specific names of network elements, interfaces, or signaling, but only indicates the function of the network element, interface, or signaling, which can be extended to other systems, such as 2G, 3G, 4G, or future communication systems.

[0153] The above Figure 1 The network architecture shown in this application embodiment is merely an example. The network architecture applicable to this application embodiment is not limited to this. Any network architecture that can realize the functions of the above-mentioned network elements is applicable to this application embodiment.

[0154] For example, in some network architectures, network function elements such as AMF, session management function, PCF, BSF, and UDM are all called network function (NF) elements; or, in other network architectures, a collection of elements such as AMF, session management function, PCF, BSF, and UDM can be called control plane function elements.

[0155] The technical solutions of this application can be applied to various communication systems, such as: Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD) systems, Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) systems, 5th Generation (5G) systems, New Radio (NR) systems, or future networks. The technical solutions provided in this application can also be applied to future communication systems, such as 6th Generation mobile communication systems. Communication systems can also be public land mobile networks (PLMNs), device-to-device (D2D) communication systems, machine-to-machine (M2M) communication systems, Internet of Things (IoT) communication systems, or other communication systems.

[0156] In this embodiment, the user equipment or access network device includes a hardware layer, an operating system layer running on top of the hardware layer, and an application layer running on top of the operating system layer. The hardware layer includes hardware such as a central processing unit (CPU), a memory management unit (MMU), and memory (also called main memory). The operating system can be any one or more computer operating systems that implement business processing through processes, such as Linux, Unix, Android, iOS, or Windows. The application layer includes applications such as browsers, address books, word processing software, and instant messaging software. Furthermore, this embodiment does not specifically limit the specific structure of the execution entity of the method provided in this embodiment, as long as it can communicate according to the method provided in this embodiment by running a program that records the code of the method provided in this embodiment. For example, the execution entity of the method provided in this embodiment can be a user equipment or access network device, or a functional module in the user equipment or access network device that can call and execute a program.

[0157] Furthermore, various aspects or features of this application can be implemented as methods, apparatus, or articles of manufacture using standard programming and / or engineering techniques. The term "article of manufacture" as used herein encompasses a computer program accessible from any computer-readable device, carrier, or medium. For example, computer-readable media may include, but are not limited to: magnetic storage devices (e.g., hard disks, floppy disks, or magnetic tapes), optical discs (e.g., compact discs (CDs), digital versatile discs (DVDs), etc.), smart cards, and flash memory devices (e.g., erasable programmable read-only memory (EPROMs), cards, sticks, or key drives, etc.). Additionally, the various storage media described herein may represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable storage medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing, and / or carrying instructions and / or data.

[0158] This application also involves multicast methods in its embodiments. Figure 2 A network architecture for multicast / broadcast services is provided. This architecture is based on... Figure 1Based on the architecture shown, it can be extended, for example, by adding two functional entities such as the multicast / broadcast session management function (MB-SMF) and the multicast broadcast user plane function (MB-UPF) to support multicast / broadcast services / functions.

[0159] It should be noted that the communication method provided in this application is also applicable to data transmission of services in broadcast mode. When the communication method provided in this application is applied to data transmission of services in broadcast mode, multicast in the embodiments of this application can be replaced with broadcast. The specific data transmission process is similar to multicast, and broadcast mode will not be described in detail in this application.

[0160] exist Figure 2 In this application, the MB-SMF can implement the control plane functions of multicast / broadcast services, and is responsible for the management of multicast / broadcast services / groups / sessions. The MB-SMF can connect to the server of the multicast / broadcast service, or a multicast / broadcast service function (MBSF) or network exposure function (NEF) to receive relevant information about the multicast / broadcast service (e.g., a description of the multicast / broadcast service). Furthermore, the MB-SMF can also connect to the PCF to create resources for multicast / broadcast services. The MBU-UPF can be used to transmit multicast / broadcast service data. Optionally, the MB-SMF can be integrated into the PCF or SMF as a functional module, the MB-UPF can be integrated into the UPF as a functional module, or the MB-SMF and MB-UPF can be deployed separately; this application does not limit this.

[0161] It should be noted that the name MB-SMF or MB-UPF mentioned above is an example. In 5G networks, MB-SMF or MB-UPF can also be other names, and this application does not limit them.

[0162] The following section introduces the key technical terms involved in the embodiments of this application. It should be noted that these explanations are intended to make the embodiments of this application easier to understand and should not be considered as limiting the scope of protection claimed in this application.

[0163] (1) Unicast.

[0164] The unicast in this application specifically refers to the following:

[0165] Specifically, at the core network level, unicast refers to sending service data to the terminal through a protocol data unit (PDU) session.

[0166] The unicast mode of multicast / broadcast services can refer to sending multicast / broadcast service data to the terminal through a PDU session. It can be referred to as the unicast mode or the 5GC individual multicast / broadcast service traffic delivery method.

[0167] The following uses PDU sessions and Figure 2 The system architecture shown below serves as an example to illustrate the data transmission process using unicast. Please refer to [the documentation / reference]. Figure 3 , Figure 3 A schematic diagram of the data transmission process in unicast mode is shown. Figure 3 The transmission process shown can be used to transmit both unicast service data and multicast / broadcast service data (via unicast).

[0168] exist Figure 3 In this diagram, each of the three user equipment (UEs), such as UE1, UE2, and UE3, corresponds to a different PDU session. Multicast / broadcast service data sent by the content provider (CP) can be transmitted to the UEs through their respective PDU sessions. The PDU sessions illustrated are assumed to be associated with multicast / broadcast services. Specifically, the service transmission path from the CP to the NG-RAN can include the transmission path between the CP and the 5G CN (5G core network), and the transmission path between the 5G CN and the NG-RAN. The transmission path between the 5G CN and the NG-RAN can be a PDU session tunnel, such as the N3 tunnel between the PSA-UPF and the NG-RAN. Different PDU sessions have different PDU session tunnels. The three PDU session tunnels in this diagram correspond to the three UEs respectively. On the air interface, the RAN can send service data to UE1, UE2, and UE3 respectively via unicast, i.e., PTP. In this diagram, the service data of each UE can be different (for example, the destination address is the IP address of each UE), and the service data of each UE can be sent to each UE through their own independent transmission path.

[0169] (2) Multicast / broadcast.

[0170] The multicast / broadcast in this application specifically refers to the following:

[0171] Specifically, at the core network level, multicast / broadcast refers to sending multicast / broadcast service data to terminal devices through multicast / broadcast sessions. It can be referred to as multicast / broadcast mode or 5G core shared MBS traffic delivery method.

[0172] In this embodiment, the multicast / broadcast mode in the transmission method determined by the SMF refers to sending multicast / broadcast service data to the terminal device through a multicast / broadcast session. Multicast / broadcast service: can be described by multicast / broadcast service information. The multicast / broadcast service information includes at least descriptive information, which may include descriptive information for one or more multicast / broadcast service flows. The descriptive information for a multicast / broadcast service flow includes at least one of the following: a Quality of Service Index (QoS flowidentifier, QFI) that the multicast / broadcast service flow should possess, characteristic information of the multicast / broadcast service flow (such as the destination address, destination port number, source address, etc.), and QoS requirements of the multicast / broadcast service flow (such as jitter, latency, packet loss rate, bandwidth, etc.). The QoS requirements of the multicast / broadcast service flow are used to establish the multicast / broadcast QoS flow. The PDU session tunnel corresponds to the UE, and service data within the PDU session tunnel can be transmitted in the form of a unicast QoS flow. In this embodiment, the PDU session tunnel can also be used to transmit the unicast QoS stream mapped to the multicast / broadcast QoS stream corresponding to the multicast / broadcast service. It should be noted that the PDU session is at the UE level, while the multicast / broadcast session is at the service level. One PDU session of a UE can be associated with multiple multicast / broadcast services; that is, the UE can join at least one multicast / broadcast service through this PDU session. A multicast / broadcast session can provide services for one multicast / broadcast service. A multicast / broadcast session includes a unicast or multicast tunnel from the data network to the core network equipment and then to the radio access network, as well as unicast or multicast / broadcast air interface resources allocated by the radio access network for transmitting the multicast / broadcast service.

[0173] In addition to the description information of the multicast / broadcast service, the information of the multicast / broadcast service may also include terminal information, such as the identifiers of one or more terminals that are allowed (or requested) to join the multicast / broadcast service, the identifiers of one or more terminal groups, etc.

[0174] by Figure 2 The system architecture shown is an example to illustrate the data transmission process for multicast / broadcast methods. Please refer to [the documentation / reference]. Figure 4 , Figure 4 A schematic diagram of the data transmission process in multicast / broadcast mode is shown. Figure 4 The transmission flow shown can be used to transmit data for multicast / broadcast services.

[0175] exist Figure 4 In this multicast / broadcast service, data can be sent from the CP to UE1, UE2, and UE3. The multicast / broadcast transmission path from the CP to the NG-RAN can include the transmission path between the CP and the 5G CN, and the transmission path between the 5G CN and the NG-RAN. The transmission path from the 5G CN to the NG-RAN can be a multicast / broadcast session tunnel, specifically the N3 tunnel between the MB-UPF and the NG-RAN, which is shared by UE1, UE2, and UE3. On the air interface, the RAN can send the aforementioned multicast / broadcast service data to UE1, UE2, and UE3 via PTM, meaning only one set of data needs to be sent, and all three UEs can receive it. Figure 4 In the example, the data for multicast / broadcast services is sent only once along the transmission path from the CP to the UE, and multiple UEs can receive it simultaneously.

[0176] Using multicast / broadcast methods, service data can be transmitted to all target nodes at once, or only to specific objects. Therefore, in multicast mode, point-to-multipoint transmission can be achieved between a sending node and multiple receiving nodes, thus solving the problem of low efficiency in unicast mode.

[0177] The fact that access network equipment supports multicast / broadcast functions can be understood as the access network equipment supporting the transmission of multicast / broadcast service data in a multicast / broadcast manner.

[0178] Access network equipment does not support multicast / broadcast functionality: This can be understood as the access network equipment not supporting the transmission of multicast / broadcast service data in a multicast / broadcast manner, or the access network equipment only supporting the transmission of multicast / broadcast service data or PDU session data in a unicast manner. For access network equipment that does not support multicast / broadcast functionality, network services for terminal devices can be implemented through PDU sessions. For access network equipment that supports multicast / broadcast functionality, multicast / broadcast service data can be received from the core network through a multicast / broadcast session tunnel and sent to multiple terminal devices that have joined the multicast / broadcast service. It should be understood that after the multicast / broadcast service data arrives at the RAN, it undergoes processing through the RAN's Service Data Adaptation Protocol (SDAP) layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, Media Access Control (MAC) layer, and Physical (PHY) layer before being sent to each UE receiving the multicast / broadcast service data.

[0179] The first transmission resource can be the QoS stream corresponding to the first multicast / broadcast service and / or the radio bearer mapped to / corresponding to that QoS stream. The radio bearer can be, for example, a data radio bearer (DRB) or a multicast radio bearer (MRB). The first QoS stream is used to transmit the first multicast / broadcast service and may be a unicast QoS stream mapped to or corresponding to the multicast / broadcast service, or it can be a multicast / broadcast QoS stream itself. The unicast QoS stream is the QoS stream used to transmit service data within a PDU session. Because the PDU session is at the UE level or UE granularity, the unicast QoS stream is also at the UE level. The multicast / broadcast QoS stream is the QoS stream used to transmit multicast / broadcast service data within a multicast / broadcast session. Because the multicast / broadcast session is at the service level or service granularity, the multicast / broadcast QoS stream is also at the service level.

[0180] If the cell or access network does not support multicast / broadcast functionality, the multicast / broadcast service can be transmitted via unicast QoS streams and DRBs. When the access network device or cell supports it, the multicast / broadcast service is sent using a multicast / broadcast QoS stream and the corresponding radio bearer (e.g., multicast radio bearer MRB).

[0181] It should be noted that the multicast mentioned in this application can also be called multicast. In addition, multicast / broadcast can be replaced with multicast or broadcast without restriction.

[0182] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0183] Figure 5 This is an illustrative flow diagram of a multicast / broadcast service communication method 500 provided in an embodiment of this application. This method can be applied to the process of a terminal handing over from a source access network (source-gNB, S-gNB) device to a target access network (target-gNB, T-gNB) device, and can also be applied to a terminal performing co-site cell handover, that is, the process of a terminal handing over from one cell to another target cell under the same access network device. The method 500 includes at least the following steps:

[0184] S510: Network devices obtain reference location information of terminals.

[0185] The reference location information can be used to characterize the reference location of the terminal. The reference location can be the location information of the terminal under the access network equipment currently providing services to it, and this location information may include the identifier of the cell where the terminal is currently located. Alternatively, the reference location can be the location information of the terminal under its target access network equipment, and this location information includes at least one of the following: cell identifier, access network equipment identifier, tracking area identifier, and public land mobile network (PLMN) identifier. It may also include global positioning system (GPS) geographic location information, sector identifier, PCI, antenna identifier, DU identifier, etc.

[0186] Optionally, when the reference location information includes the location information of the terminal under the access network device currently providing services to the terminal, the location information may be one or more combinations of the identifier of the current serving cell, the identifier of the access network of the current serving terminal, and the identifier of the current tracking area.

[0187] Optionally, when the reference location information includes the terminal's location information under its T-gNB, the location information may be one or more of the following: the identifier of the target cell, the identifier of the T-gNB, the identifier of the target tracking area, etc.

[0188] For example, when a terminal performs a co-site cell handover, the reference location information can be the location information of the access network device currently providing services to the terminal, such as the identifier of the target cell where the terminal is currently located. When the terminal performs a non-co-site handover, the reference location information can be the location information of the terminal under its T-gNB, for example, it can be the identifier of the terminal's target cell and / or the identifier of the terminal's T-gNB. Co-site can be, for example,... Figure 6 The scene shown is in Figure 6 In this context, the access network device is one that does not support multicast / broadcast functions, and the service area for the first multicast / broadcast service is cells 1 and 3 under this access network device. Non-co-site handover can include scenarios such as N2 handover and Xn handover.

[0189] S520: When the reference location of the terminal is within the service area of ​​the first multicast / broadcast service, the network device triggers the target access network device of the terminal to allocate transmission resources to the terminal.

[0190] S520 can be replaced by the following: when the reference location of the terminal is within the service area of ​​the first multicast / broadcast service, the network device triggers the access network device of the cell where the current terminal is located to allocate or establish transmission resources for the terminal, or triggers the target access network device of the terminal to allocate transmission resources for the terminal, based on the reference location of the terminal and the service area of ​​the first multicast / broadcast service.

[0191] Furthermore, it can also be based on measurement reports. For example, when the network device is the source base station's Xn handover, the source base station triggers the handover upon receiving the measurement report.

[0192] Furthermore, a PDU session context update request can also be made. This PDU session context update request can be Nsmf_PDUSession_UpdateSMContext. For example, when the network device is an N2 handover of an SMF, the SMF triggers this request after receiving Nsmf_PDUSession_UpdateSMContext.

[0193] The transmission resource can be used to transmit the data of the first multicast / broadcast service, which may be, for example, a wireless bearer.

[0194] Optionally, the network device can be an SMF or the terminal's S-gNB.

[0195] Specifically, when the network device is an SMF (Self-Managed Provider), the network device triggers the access network device of the cell where the current terminal is located to allocate transmission resources for the terminal. This can be achieved by the SMF triggering the access network device of the cell where the current terminal is located to establish transmission resources for the terminal. When the network device is an SMF or an S-gNB (Self-Managed Provider Interface), the network device triggers the target access network device of the terminal to allocate transmission resources for the terminal. This can be applied during the handover process from the source access network device to the target access network.

[0196] It should be noted that the above-mentioned triggering process may be, for example, the SMF sending an indication message to the access network equipment of the cell where the current terminal is located to trigger the process, or the SMF or S-gNB sending an indication message to the target access network equipment of the terminal to trigger the process of allocating transmission resources, etc., and this application does not limit it.

[0197] The communication method for multicast / broadcast services provided in this application dynamically determines the reference location information of the terminal through network equipment. When the terminal's T-gNB is in the service area of ​​the first multicast / broadcast service, it triggers the terminal's T-gNB to allocate resources to the terminal, thereby improving the utilization efficiency of network resources.

[0198] Next, taking SMF and S-gNB as network devices respectively, the method 500 of this application embodiment will be described in detail. Specifically, as follows... Figures 7 to 9 The explanation will be based on an example of a network device called SMF.

[0199] First, let's explain why the network device is SMF.

[0200] When the network device is an SMF, it can be as follows: Figure 7 The diagram shown is an illustrative flowchart of a terminal performing co-site cell handover applicable to this embodiment.

[0201] S701, the access network equipment reports the terminal reference location information to the AMF.

[0202] Specifically, the reference location information can be the location information of the access network device currently providing services to the terminal. For example, when the terminal moves from cell 2 to cell 3, the access network device can report the identifier of cell 3 to the AMF, and the identifier of cell 3 can be the aforementioned location information.

[0203] S702, SMF determines that the current access network equipment supports the first multicast / broadcast service.

[0204] Here, the terminal's current access network device can be understood as the access network device currently providing services to the terminal.

[0205] The SMF determines that the current access network device supports the first multicast / broadcast service. For example, when the UE joins a multicast / broadcast session through a PDU session modification request, the AMF will report the multicast / broadcast capabilities of the network device to which the UE is currently accessing. The SMF then determines that the current access network device supports the first multicast / broadcast service based on the multicast / broadcast capabilities of that access network device.

[0206] S703, SMF subscribes to the AMF for the location information of the terminal.

[0207] S703 is an optional step. The AMF can proactively report the terminal's location information to the SMF, or it can report the terminal's location information based on the SMF's request. There is no restriction.

[0208] S704, AMF reports the terminal's location information to SMF.

[0209] Specifically, the AMF can report the identifier of cell 3 to the SMF.

[0210] S705, SMF allocates transmission resources to the terminal.

[0211] Specifically, based on the terminal's location information, the SMF continues to execute the process of the terminal joining multicast / broadcast services, for example, allocating or adding unicast QoS stream information mapped to multicast / broadcast QoS streams in the PDU session associated with the multicast / broadcast service.

[0212] It should be noted that PDU sessions associated with multicast / broadcast services can also be called unicast fall-back PDU sessions, or PDU sessions for 5GC shared delivery method to individual delivery method switch, or 5GC individual MBS traffic delivery method, or PDU sessions corresponding to 5GC individual delivery method, or PDU sessions corresponding to individual delivery method.

[0213] It should be understood that the transmission resources can be used to transmit the data of the first multicast / broadcast service. It should be noted that the allocated resources can also be understood as establishing a QoS stream for transmitting multicast / broadcast service data; this application does not limit this interpretation.

[0214] The communication method for multicast / broadcast services provided in this application dynamically determines the reference location information of the terminal through SMF. When the terminal is in the service area of ​​the first multicast / broadcast service, it triggers the access network equipment currently providing services to the terminal to allocate or establish resources for the terminal, thereby improving the utilization efficiency of network resources.

[0215] like Figure 8 As shown in the figure, this embodiment provides a schematic flowchart of a terminal performing a handover in a non-co-located cell N2. Figure 8 The illustrated embodiment uses SMF as an example of a network device.

[0216] S801, the UE sends a measurement report to the S-gNB.

[0217] Correspondingly, the S-gNB receives the measurement report and decides to switch the UE to the T-gNB based on the measurement report. The decision to switch the UE to the T-gNB based on the measurement report is existing technology and will not be elaborated further.

[0218] S802, the S-gNB sends a handover required message to the source AMF (S-AMF). For example, the "handover required message" includes the PDU session information of the UE to be handed over. The PDU session information may include the PDU session identifier and the QoS information corresponding to the unicast QoS stream contained in the PDU session.

[0219] The QoS information for unicast QoS streams includes QFI and QoS parameters.

[0220] Furthermore, if the UE's PDU session is associated with a multicast / broadcast service, for example, a first multicast / broadcast service, the PDU session information may also include information about the unicast QoS stream mapped to the multicast / broadcast QoS stream. For example, if the PDU session is associated with a first multicast / broadcast service, the PDU session information may also include the identifier of the first unicast QoS stream, and the first unicast QoS stream has a mapping relationship with the multicast / broadcast QoS stream used to transmit data for the first multicast / broadcast service.

[0221] The "handover requirement" also includes a target identifier (Target ID), which can be the identification information of the target cell to which the UE is about to handover.

[0222] In addition, "Switching Requirements" can also include N2 SM Information. If the SM N2 Information indicates that there is no direct forwarding tunnel between S-gNB and T-gNB, it means that an indirect forwarding tunnel can be established between S-gNB and T-gNB. In this case, the SM N2 Information can include the indirect forwarding tunnel information allocated by S-gNB.

[0223] The "Switch Requirement" may also include an identifier of the QoS stream that the S-gNB wants to forward via the forwarding tunnel. For example, if a multicast / broadcast QoS stream needs to be forwarded via the forwarding tunnel, the handover request includes the QFI of the unicast QoS stream corresponding to that multicast / broadcast QoS stream.

[0224] S803, S-AMF selects the target AMF (target-AMF, T-AMF) based on the Target ID.

[0225] Among them, T-AMF is connected to T-gNB.

[0226] S804, S-AMF sends a request to T-AMF to create UE context.

[0227] The UE context creation request can be Namf_Communication_CreateUEContextRequest, which can contain the UE context information of the handover that has occurred stored in the S-AMF, and can also contain the information sent by the S-gNB to the S-AMF in step 802.

[0228] S805, T-AMF sends a PDU session context update request to SMF.

[0229] The PDU session context update request can be Nsmf_PDU Session_UpdateSMContextRequest. This request message can contain PDU session identification information (e.g., PDU session ID), T-AMF identification information (e.g., T-AMF ID), Target ID, N2 SM information, etc.

[0230] S806-S808 correspond to SMF sending message 01, message 02, and message 03 to UDR / UDM / PCF, respectively.

[0231] Among them, message 01 can be used by the SMF to query the UDR / UDM / PCF for the context information of the first multicast / broadcast service; message 02 can be used by the SMF to query the UDR / UDM / PCF for the context information of the first multicast / broadcast service corresponding to the location information corresponding to the Target ID; and message 03 can be used by the SMF to query the UDR / UDM / PCF for the context information of the first multicast / broadcast service corresponding to the location information corresponding to the target access network device.

[0232] It should be noted that the above context information may include identification information for multicast / broadcast services. For example, it may be any one of the following, or a combination of one or more of the following, without limitation: the identifier of the multicast / broadcast service, the name of the multicast / broadcast service, the multicast / broadcast address of the multicast / broadcast service, the multicast / broadcast IP address of the multicast / broadcast service, the temporary mobile group identity (TMGI) corresponding to the multicast / broadcast service, and the session address of the multicast / broadcast service, etc. This context information may also include service area information corresponding to the multicast / broadcast service. For example, it may be one or more of the following, or any combination of one or more of them, including: geographical area information, public land mobile network information, tracking area information, cell identification information, base station identification information, base station centralized unit identification information, base station distributed unit identification information (DU), and may also be a civil address list, etc. This context information also includes the area session identifier of the service area corresponding to the multicast / broadcast service, etc.

[0233] S809, SMF determines that the terminal's reference location is within the service area of ​​the first multicast / broadcast service.

[0234] Specifically, if the SMF stores the context information of the terminal in the first multicast / broadcast service in the S-gNB, the SMF determines that the identifier of the terminal's target cell and / or the identifier of the terminal's T-gNB are included in the service area in the context information of the first multicast / broadcast service.

[0235] S811, SMF sends a PDU session context update response to T-AMF.

[0236] The PDU session context update response can be Nsmf_PDU Session_UpdateSMContextResponse.

[0237] When the SMF determines that the terminal's reference location is within the service area of ​​the first multicast / broadcast service, the SMF sends a PDU session context update response to the T-AMF.

[0238] Specifically, the SMF can instruct the T-AMF to allocate or establish transport resources for the terminal through the PDU session context update response.

[0239] The PDU session context update response message may include QoS information of the unicast QoS stream of the PDU session, which may include the unicast QoS stream mapped by the first multicast / broadcast QoS stream.

[0240] The QoS information may include QFI and the corresponding QoS parameters.

[0241] Optionally, if the SMF does not store the context information of the first multicast / broadcast service of the terminal in the S-gNB, the SMF may send message 01 to the UDR / UDM / PCF to obtain the context information of the first multicast / broadcast service.

[0242] S812, the T-AMF sends a handover request to the T-gNB.

[0243] The message includes the QoS information of the unicast QoS stream contained in the PDU session. At this time, the T-gNB allocates radio resources to the unicast QoS stream based on the QoS information of the QoS stream.

[0244] It should be understood that, for the sake of simplicity, the above... Figure 8 The other steps in the process are not described in detail. These steps should be understood as existing technology in N2 switching and will not be elaborated further.

[0245] The communication method for multicast / broadcast services provided in this application dynamically determines the reference location information of the terminal through SMF. When the terminal is in the service area of ​​the first multicast / broadcast service, it triggers the T-gNB of the terminal to allocate or establish resources for the terminal, thereby improving the utilization efficiency of network resources.

[0246] like Figure 22 As shown in the figure, this embodiment provides a schematic flowchart of a terminal performing a handover in a non-co-located cell N2. Figure 22 The illustrated embodiment uses SMF as an example of a network device.

[0247] S2201, the UE sends a measurement report to the source base station (S-gNB).

[0248] Correspondingly, the S-gNB receives the measurement report, which can contain signal measurement values ​​from up to eight neighboring cells measured by the UE. Based on the measurement report, the S-gNB decides to hand over the UE to the T-gNB. For example, the source base station selects the base station of the neighboring cell with the strongest signal as the T-gNB to which the UE will hand over; that is, the S-gNB is the T-gNB selected by the UE. The specific implementation of the above-described handover of the UE to the T-gNB based on the measurement report can be found in the descriptions in current related technologies and will not be elaborated further.

[0249] In S2202, the S-gNB sends a handover required message to the S-AMF. The difference from S802 is that the N2 session management information (N2 SMInformation) in the handover required message in S2202 includes the target cell ID. For example, the N2 session management information can be a handover required transfer. Alternatively, the target cell ID can be a cell listed alongside the N2 session management information.

[0250] Specifically, after the S-gNB obtains the target cell identifier, the S-gNB discovers / determines that the terminal device has joined the first multicast / broadcast service, and then sends a handover request to the S-AMF.

[0251] Furthermore, it should be noted that the S-gNB obtains the target cell identifier in several ways. For example, the S-gNB itself may store cell identifier information for other base stations, such as the identifiers of cells contained in adjacent base stations. Alternatively, the S-gNB may obtain cell identifier information for other base stations based on operation, administration, and maintenance (OAM) procedures, such as the identifiers of cells contained in adjacent base stations. Or, the S-gNB may obtain cell identifier information for other base stations based on measurement reports sent by the UE, etc.

[0252] In one specific implementation, if the S-gNB discovers that the UE has joined a multicast / broadcast service, for example, the first multicast / broadcast service, the handover request sent by the S-gNB to the S-AMF carries the target cell ID. This target cell ID is contained in the N2 session management information (N2 SM Information), which can be a handover required transfer. This N2 session management information is a parallel information element with the handover type, source to target transparent container, target ID, etc. Alternatively, the target cell identification information is an information element listed alongside the N2 session management information. This information element listed alongside the N2 session management information may, for example, include, in addition to the information elements included in the existing handover required information elements: handover type, target ID, cause value, source to target transport container, PDU session resource list, message type, AMF UE NGAP ID, and RAN UE NGAP ID, the target cell identification information as an additional information element listed alongside the aforementioned information elements included in the existing handover required information elements. For example, in addition to the information elements included in the existing technology handover requirements, such as handover type, target ID, cause value, source to target transport container, PDU session resource list, message type, AMF UE NGAPID, and RAN UE NGAP ID, the target cell identification information can be added as an extra information element and not carried in any of the information elements included in the existing technology handover requirements, but rather carried as an independent information element in the handover requirements.

[0253] In one feasible approach, the S-gNB can detect whether the UE has joined a multicast / broadcast service in the following ways:

[0254] In the first approach, the S-gNB can determine whether the UE has joined a multicast / broadcast service based on whether the UE's context contains the identifier of the first multicast / broadcast service (e.g., MBS Session ID or TMGI) or whether the S-gNB can determine whether the UE's context contains the identifier of the first multicast / broadcast service (e.g., MBS Session ID or TMGI) and the area session identifier (e.g., Area Session ID or Flow ID).

[0255] For non-regional multicast / broadcast services, i.e., when the first multicast / broadcast service is a non-regional multicast / broadcast service, if the UE's context contains the identifier of the first multicast / broadcast service (e.g., MBS Session ID or TMGI), it indicates that the UE has joined the first multicast / broadcast service. Conversely, if the UE's context does not contain the identifier of the first multicast / broadcast service (e.g., MBS Session ID or TMGI), it indicates that the UE has not joined the first multicast / broadcast service.

[0256] For area multicast / broadcast services, specifically when the first multicast / broadcast service is an area multicast / broadcast service, if the UE's context contains the identifier of the first multicast / broadcast service (e.g., MBS Session ID or TMGI) and the area session identifier (e.g., Area Session ID or Flow ID), it indicates that the UE has joined the first multicast / broadcast service. Conversely, if the UE's context does not contain the identifier of the first multicast / broadcast service (e.g., MBS Session ID or TMGI) and the area session identifier (e.g., Area Session ID or Flow ID), it indicates that the UE has not joined the first multicast / broadcast service.

[0257] In the second approach, the S-gNB can determine whether the UE has joined the first multicast / broadcast service by checking whether the context corresponding to the first multicast / broadcast service (MBS session context) contains the UE's identification information (e.g., New Generation Application Protocol UE ID, NGAP UE ID, Subscription Permanent Identifier, Generic Public Subscription Identifier, or Subscription Concealed Identifier, SUCI). If the context corresponding to the first multicast / broadcast service contains the UE's identification information, it indicates that the UE has joined the first multicast / broadcast service. Conversely, if the context corresponding to the first multicast / broadcast service does not contain the UE's identification information, it indicates that the UE has not joined the first multicast / broadcast service.

[0258] In the third approach, the S-gNB can determine whether the UE's context contains the identifier of the first multicast / broadcast service (e.g., MBS Session ID or TMGI) or whether the S-gNB contains both the identifier of the first multicast / broadcast service (e.g., MBS Session ID or TMGI) and the area session identifier (e.g., Area Session ID or Flow ID) in the UE's context. At the same time, the S-gNB can determine whether the UE's identification information (e.g., NGAP UE ID, SUPI, GPSI, or SUCI) is contained in the context corresponding to the first multicast / broadcast service (MBS session context).

[0259] For non-regional multicast / broadcast services, meaning the first multicast / broadcast service is a non-regional multicast / broadcast service, if the UE's context contains the identifier of the first multicast / broadcast service (e.g., MBS Session ID or TMGI), and the context corresponding to the first multicast / broadcast service also contains the UE's identification information, then the UE has joined the first multicast / broadcast service. Conversely, if the UE's context does not contain the identifier of the first multicast / broadcast service (e.g., MBS Session ID or TMGI), and the context corresponding to the first multicast / broadcast service does not contain the UE's identification information, then the UE has not joined the first multicast / broadcast service.

[0260] For area multicast / broadcast services, specifically when the first multicast / broadcast service is an area multicast / broadcast service, if the UE's context contains the identifier of the first multicast / broadcast service (e.g., MBS Session ID or TMGI) and the area session identifier (e.g., Area Session ID or Flow ID), and the context corresponding to the first multicast / broadcast service contains the UE's identification information, then the UE has joined the first multicast / broadcast service. Conversely, if the UE's context does not contain the identifier of the first multicast / broadcast service (e.g., MBS Session ID or TMGI) and the area session identifier (e.g., Area Session ID or Flow ID), and the context corresponding to the first multicast / broadcast service does not contain the UE's identification information, then the UE has not joined the first multicast / broadcast service.

[0261] Furthermore, the S-gNB may use other methods to determine whether the UE has joined the first multicast / broadcast service, and this application does not limit such methods.

[0262] It should be noted that when the S-gNB determines whether the UE has joined multiple multicast / broadcast services, for example, whether the S-gNB has joined the first multicast / broadcast service and the second multicast / broadcast service, the above three or other methods can be used to determine whether the UE has joined both the first and second multicast / broadcast services simultaneously. This determination method is similar to determining whether the UE has joined the first multicast / broadcast service, and will not be elaborated here.

[0263] S2203 is the same as S802, so it will not be described again here.

[0264] In S2204, the S-AMF sends a UE context creation request to the T-AMF. Unlike S804, the N2 session management information (N2 SM Information) in the UE context creation request sent by the S-AMF to the T-AMF also includes the target cell ID. This N2 session management information can be a handover required transfer. Alternatively, the target cell ID can be a data element listed alongside the N2 session management information, as explained above, and will not be repeated here.

[0265] In step S2205, the T-AMF sends a PDU session context update request to the SMF. Unlike step S805, the N2 session management information (N2 SM Information) in the T-AMF's PDU session context update request also includes the target cell ID. This N2 session management information can be a handover required transfer. Alternatively, the target cell ID can be a data element listed alongside the N2 session management information, as explained above and will not be repeated here.

[0266] Based on the target cell ID, if the SMF discovers that the target cell (target cell ID) is outside the service area of ​​the first multicast / broadcast service, the SMF can release the terminal's first transmission resources. These first transmission resources are used to transmit data for the first multicast / broadcast service, including resources for the terminal to transmit the data through its T-gNB. Alternatively, if the SMF discovers that the target cell (target cell ID) is outside the service area of ​​the first multicast / broadcast service, the SMF will not send the QoS information corresponding to the first multicast / broadcast service to the target access network device. In other words, the N2 Session Management Information (N2 SM Information) sent by the SMF to the T-gNB does not include the QoS information corresponding to the first multicast / broadcast service.

[0267] It should be noted that "release" can also be understood as triggering release, triggering deletion, deleting, initiating deletion, or terminating, etc.

[0268] Based on the target cell ID, if the SMF discovers that the UE's target cell (target cell ID) is within the service area of ​​the second multicast / broadcast service, the SMF can initiate the establishment / configuration of the terminal's second transmission resources. These second transmission resources are used to transmit data for the second multicast / broadcast service, including resources for the terminal to transmit this data via the T-gNB. The description of the second transmission resources can be the same as the first transmission resources, and will not be repeated here. Alternatively, if the SMF discovers that the target cell (target cell ID) is within the service area of ​​the second multicast / broadcast service, the SMF sends the QoS information corresponding to the second multicast / broadcast service to the terminal's target access network equipment. In other words, the N2 Session Management Information (N2 SM Information) sent by the SMF to the terminal's target access network equipment contains the QoS information corresponding to the second multicast / broadcast service.

[0269] It should be noted that "release" can also be understood as triggering release, triggering deletion, deleting, initiating deletion, or terminating, etc.

[0270] The subsequent S2206~S2212 are the same as S806~S812, and will not be repeated here.

[0271] like Figure 23 As shown in the figure, this embodiment provides a schematic flowchart of a terminal performing a handover in a non-co-located cell N2. Figure 23 The illustrated embodiment uses SMF as an example of a network device.

[0272] S2301, the UE sends a measurement report to the source base station (S-gNB).

[0273] Correspondingly, the S-gNB receives the measurement report, which can contain signal measurement values ​​from up to eight neighboring cells measured by the UE. Based on the measurement report, the S-gNB decides to hand over the UE to the T-gNB. For example, the S-gNB selects the base station of the neighboring cell with the strongest signal as the T-gNB to which the UE will hand over; that is, the S-gNB is the T-gNB selected by the UE. The above-described method of deciding to hand over the UE to the T-gNB based on the measurement report can be found in current related technical descriptions, and will not be elaborated upon here.

[0274] If the S-gNB discovers that the UE has joined a multicast / broadcast service, for example, a first multicast / broadcast service and / or a second multicast / broadcast service, and the S-gNB also discovers that the target cell ID is outside the service area of ​​the first multicast / broadcast service and / or within the service area of ​​the second multicast / broadcast service, the S-gNB carries indication information in the N2 Session Management Information (N2 SM Information) sent to the S-AMF in S2302. This indication information includes first indication information and / or second indication information. The first indication information can be used to notify the SMF that the target cell ID is outside the service area of ​​the first multicast / broadcast service, and the second indication information can be used to notify the SMF that the target cell ID is within the service area of ​​the second multicast / broadcast service. The N2 Session Management Information may be a Handover Required Transfer.

[0275] In addition, the switching requirement also includes the identifier of the first multicast / broadcast service and / or the identifier information of the second multicast / broadcast service.

[0276] In S2302, the S-gNB sends a handover required message to the S-AMF. Unlike S802, the N2 session management information (N2 SM Information) in the handover required message of S2302 also includes indication information, namely, first indication information and / or second indication information. The N2 session management information can be a handover required transfer. Alternatively, the indication information can be a data element parallel to the N2 session management information. The data elements parallel to the N2 session management information have been explained above and will not be repeated here.

[0277] It should be noted that when it is necessary to indicate to the SMF that the target cell ID is outside the service area of ​​the first multicast / broadcast service, the S-gNB carries the first indication information in the N2 Session Management Information (N2SM Information) required for handover sent to the S-AMF in S2302. When it is necessary to indicate to the SMF that the target cell ID is within the service area of ​​the second multicast / broadcast service, the S-gNB carries the second indication information in the N2 Session Management Information (N2 SM Information) required for handover sent to the S-AMF in S2302. When it is necessary to indicate to the SMF that the target cell ID is outside the service area of ​​the first multicast / broadcast service and also that the target cell ID is within the service area of ​​the second multicast / broadcast service, the S-gNB carries the first indication information and / or the second indication information in the N2 Session Management Information (N2 SM Information) required for handover sent to the S-AMF in S2302. Here, the indication can also be understood as a notification or notification. The N2 session management information may be a Handover Required Transfer. Alternatively, the first indication information and / or the second indication information may be information elements listed alongside the N2 session management information. The information elements listed alongside the N2 session management information have been explained above and will not be repeated here.

[0278] The first indication information can correspond to the identifier of the first multicast / broadcast service, and the second indication information can correspond to the identifier of the second multicast / broadcast service.

[0279] S2303 is the same as S802, so it will not be described again here.

[0280] S2304, unlike S804, includes N2 session management information (N2 SM Information) in the UE context creation request sent by S-AMF to T-AMF, which also contains indication information, including first indication information and / or second indication information. The N2 session management information may be a Handover Required Transfer. Alternatively, the first and / or second indication information may be information elements listed alongside the N2 session management information. The information elements listed alongside the N2 session management information have been explained above and will not be repeated here.

[0281] S2305, unlike S805, includes indication information, namely first indication information and / or second indication information, in the N2 session management information (N2 SM Information) sent by T-AMF to SMF in the PDU session context update request. The N2 session management information may be a Handover Required Transfer. Alternatively, the first indication information and / or the second indication information may be information elements listed alongside the N2 session management information. The information elements listed alongside the N2 session management information have been explained above and will not be repeated here.

[0282] Based on the first and / or second indication information, if the SMF discovers that the target cell ID is outside the service area of ​​the first multicast / broadcast service, the SMF may release the terminal's first transmission resources. These first transmission resources are used to transmit data for the first multicast / broadcast service, including resources for the terminal to transmit the data through its T-gNB. Alternatively, if the SMF discovers that the target cell ID is outside the service area of ​​the first multicast / broadcast service, the SMF will not send the QoS information corresponding to the first multicast / broadcast service to the terminal's target access network device. In other words, the N2 Session Management Information (N2 SM Information) sent by the SMF to the T-gNB does not include the QoS information corresponding to the first multicast / broadcast service.

[0283] Based on the first and / or second indication information, if the SMF discovers that the target cell ID is within the service area of ​​the second multicast / broadcast service, the SMF can initiate the establishment / configuration of a second transmission resource for the terminal. This second transmission resource is used to transmit data for the second multicast / broadcast service, including resources for the terminal to transmit the data through its T-gNB. The description of the second transmission resource can be the same as the first transmission resource, and will not be repeated here. Alternatively, if the SMF discovers that the target cell ID is within the service area of ​​the second multicast / broadcast service, the SMF sends the QoS information corresponding to the second multicast / broadcast service to the target access network device of the terminal. That is, the N2 Session Management Information (N2 SM Information) sent by the SMF to the T-gNB contains the QoS information corresponding to the second multicast / broadcast service.

[0284] The subsequent S2306~S2312 are the same as S806~S812, and will not be repeated here.

[0285] like Figure 9 As shown in the figure, this embodiment provides a schematic flowchart of a terminal performing a handover in a non-co-site cell Xn. Figure 9 The illustrated embodiment uses SMF as an example of a network device.

[0286] S901 to S905 describe the handover process from S-gNB to T-gNB in ​​the prior art Xn handover procedure. For the sake of simplicity, this application will not elaborate on these details here.

[0287] S906, T-gNB sends an N2 path switch request to AMF.

[0288] For example, the request may include QFIs of unicast QoS flows for successful and failed handovers in the UE's PDU session, and / or QFIs of multicast / broadcast QoS flows for successful and failed handovers in the PDU session. As an example, these QFIs can be encapsulated in an N2 SM message. Furthermore, the N2 path handover request may also include the endpoint identifier of the PDU session tunnel allocated to the UE by the T-gNB. Alternatively, the N2 path handover request may also include the UE's location information (UE Location Information), etc. This UE location information can be the location information of the terminal under the target access network device, and may include the identifier information of the target cell, etc.

[0289] S907, AMF sends a PDU session context update request to SMF.

[0290] The PDU session context update request can be Nsmf_PDU Session_UpdateSMContextRequest.

[0291] Specifically, from Figure 9 As can be seen, when the AMF sends a PDU session context update request to the SMF, the UE has already completed the handover from the S-gNB to the T-gNB, i.e., steps 901 to 905. Therefore, the PDU session context update request carries the UE's location information under the current T-gNB.

[0292] S911, the SMF determines that the terminal's reference location is within the service area of ​​the first multicast / broadcast service. Specifically, based on the UE's location information and the multicast / broadcast context information corresponding to the first multicast / broadcast service joined by the UE in the S-gNB, the SMF determines that the UE's location information is included in the multicast / broadcast context information. For example, the SMF may determine that the target cell's identification information is included in the area identification information within the multicast / broadcast context information.

[0293] S912, SMF sends an N4 session update / modification request to PSA (UPF).

[0294] Specifically, when the SMF determines that the UE's location information is included in the multicast / broadcast context information, the SMF notifies the UPF to establish the first transport resource through the N4 session update / modification request.

[0295] It should be understood that, for the sake of simplicity, the above... Figure 9 The other steps in the process are not described in detail. These steps should be understood as existing techniques in Xn switching and will not be elaborated further.

[0296] The communication method for multicast / broadcast services provided in this application dynamically determines the reference location information of the terminal through SMF. When the terminal is in the service area of ​​the first multicast / broadcast service, it triggers PSA (UPF) to allocate or establish resources for the terminal, thereby improving the utilization efficiency of network resources.

[0297] Next, the network device will be described as an S-gNB.

[0298] like Figure 10 As shown in the figure, this embodiment provides a schematic flowchart of a terminal performing a handover in a non-co-located cell N2. Figure 10 The illustrated embodiment uses an S-gNB network device as an example for explanation.

[0299] S1001, the UE sends a measurement report to the S-gNB.

[0300] S1002, S-gNB determines that the terminal's reference location is within the service area of ​​the first multicast / broadcast service.

[0301] Specifically, after the S-gNB receives the UE's measurement report, it decides to hand over the UE to the T-gNB based on the measurement report. The measurement report carries the identification information of the T-gNB and / or the identification information of the target cell.

[0302] Since the S-gNB stores the service area information in the context information corresponding to the first multicast / broadcast service joined by the UE at the source base station, the S-gNB determines that the identification information of the T-gNB or the identification information of the target cell in the measurement report is included in the service area of ​​the first multicast / broadcast service.

[0303] S1003, S-gNB sends a handover request to S-AMF.

[0304] Specifically, when the S-gNB determines that the identification information of the T-gNB or the target cell in the measurement report is within the service area of ​​the first multicast / broadcast service, the S-gNB sends a handover request to the S-AMF. This handover request may include the PDU session of the multicast / broadcast service associated with the UE to be handed over; that is, the PDU session information contains information about the unicast QoS stream mapped by the multicast / broadcast QoS stream. Furthermore, the handover request also includes the identification information of the target cell to which the UE will hand over.

[0305] S1004-S1013, the aforementioned PDU session information is transmitted to the T-gNB. After the T-gNB receives the information, it allocates transmission resources for the UE to transmit the first multicast / broadcast service data.

[0306] Specifically, the T-gNB allocates the corresponding radio bearer based on the unicast QoS stream information mapped to the multicast / broadcast QoS stream. That is, the relevant configurations from the PDCP to the PHY layer meet the QoS parameter requirements, which may include, for example, bandwidth, latency, and jitter.

[0307] It should be noted that the above Figure 10 The other steps in the process are not described in detail. These steps should be understood as existing technology in N2 switching and will not be elaborated further.

[0308] The communication method for multicast / broadcast services provided in this application, during the N2 handover process, dynamically determines the reference location information of the terminal through S-gNBF when the terminal is in the service area of ​​the first multicast / broadcast service, triggering the terminal's T-gNB to allocate or establish resources for the terminal, thereby improving the utilization efficiency of network resources.

[0309] like Figure 11 As shown in the figure, this embodiment provides a schematic flowchart of a terminal performing a handover in a non-co-site cell Xn. Figure 11The illustrated embodiment uses an S-gNB network device as an example for explanation.

[0310] S1101, the UE sends a measurement report to the S-gNB.

[0311] S1102, S-gNB determines that the reference location of the terminal is within the service area of ​​the first multicast / broadcast service.

[0312] Specifically, after the S-gNB receives the UE's measurement report, it decides to hand over the UE to the T-gNB based on the measurement report. The measurement report carries the identification information of the T-gNB and / or the identification information of the target cell.

[0313] Since the S-gNB stores the service area information in the context information corresponding to the first multicast / broadcast service joined by the UE at the source base station, the S-gNB determines that the identification information of the T-gNB or the identification information of the target cell in the measurement report is included in the service area of ​​the first multicast / broadcast service.

[0314] S1103, S-gNB sends a handover request to T-gNB.

[0315] Specifically, when it is determined that the identification information of the T-gNB or the target cell in the measurement report is within the service area of ​​the first multicast / broadcast service, the S-gNB sends a handover request to the T-gNB. This handover request may include the PDU session of the multicast / broadcast service associated with the UE to be handed over; that is, the PDU session information contains information about the unicast QoS stream mapped by the multicast / broadcast QoS stream. Furthermore, the handover request also includes the identification information of the target cell to which the UE will hand over.

[0316] S1104, T-gNB sends a handover request response to S-gNB.

[0317] Specifically, after the T-gNB receives the handover request message of S1103, it allocates transmission resources for the UE to transmit the first multicast / broadcast service data according to the PDU session information.

[0318] It should be noted that the above explanation ( Figures 7 to 11The context information in the context may include identification information for the multicast / broadcast service. For example, it can be any one of the following, or a combination of one or more of the following, without limitation: for example, the identifier of the multicast / broadcast service, the name of the multicast / broadcast service, the multicast / broadcast address of the multicast / broadcast service, the multicast / broadcast IP address of the multicast / broadcast service, the temporary mobile group identity (TMGI) corresponding to the multicast / broadcast service, the session address of the multicast / broadcast service, etc. The context information may also include service area information corresponding to the multicast / broadcast service. For example, it can be one or more of the following, or any combination of one or more of them, including: geographical area information, public land mobile network information, tracking area information, cell identification information, base station identification information, base station centralized unit identification information, base station distributed unit identification information (DU), and also a civil address list, etc. The context information also includes the area session identifier of the service area corresponding to the multicast / broadcast service, etc.

[0319] It should be noted that the above Figure 11 The other steps in the process are not described in detail. These steps should be understood as existing techniques in Xn switching and will not be elaborated further.

[0320] The communication method for multicast / broadcast services provided in this application, during the Xn handover process, dynamically determines the reference location information of the terminal through the S-gNBF when the terminal is in the service area of ​​the first multicast / broadcast service, triggering the terminal's T-gNB to allocate or establish resources for the terminal, thereby improving the utilization efficiency of network resources.

[0321] Figure 12 This is an illustrative flowchart of a multicast / broadcast service communication method 1200 provided in this application embodiment. This method can be applied during the handover process from a terminal S-gNB to a T-gNB device, and also during the handover process between co-located cells. Method 1200 includes at least the following steps:

[0322] S1201, The network device obtains the reference location information of the terminal.

[0323] The reference location information is used to characterize the reference location of the terminal. This reference location information includes the terminal's location information under the access network equipment currently providing services to the terminal, or the terminal's location information under its T-gNB. It should be noted that the location information includes at least one of the following: cell identifier, access network equipment identifier, tracking area identifier, and public land mobile network (PLMN) identifier. It may also include global positioning system (GPS) geographic location information, sector identifier, PCI, antenna identifier, DU identifier, etc.

[0324] Optionally, when the reference location information includes the location information of the terminal under the access network device currently providing services to the terminal, the location information may be one or more combinations of the identifier of the current serving cell, the identifier of the access network of the current serving terminal, and the identifier of the current tracking area.

[0325] Optionally, when the reference location information includes the terminal's location information under its T-gNB, the location information may be one or more of the following: the identifier of the target cell, the identifier of the T-gNB, the identifier of the target tracking area, etc.

[0326] S1202, the network device initiates the release of the terminal's first transmission resources, wherein the first transmission resources are used to transmit the data of the first multicast / broadcast service, and include resources for the terminal to transmit the data of the first multicast / broadcast service through the terminal's T-gNB.

[0327] Specifically, when the network device determines that the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service, the network device triggers the release of the terminal's first transmission resources, wherein the first transmission resources are used to transmit the data of the first multicast / broadcast service.

[0328] It should be noted that initiating release can also be understood as triggering release, triggering deletion, or initiating deletion, etc.

[0329] The multicast / broadcast service communication method provided in this application, if the network device determines that the reference position of the terminal is outside the service area of ​​the first multicast / broadcast service, the network device triggers the release of transmission resources for transmitting data of the first multicast / broadcast service. Through the processing and operation of the network device, this scheme can effectively save network resources and avoid the waste of resources caused by invalid forwarding of multicast / broadcast service data.

[0330] Optionally, the network device can be an SMF or an S-gNB.

[0331] First, the method 1200 is described using the network device as an SMF. Specifically, the method may include... Figures 13 to 15 The example shown uses a network device as the SMF.

[0332] like Figure 13 As shown in the figure, this embodiment provides an illustrative flowchart of a terminal performing co-site cell handover.

[0333] S1301, the access network device reports its location information to the AMF.

[0334] Specifically, this reference location information can be the location information of the access network device currently providing services to the terminal, and the access network device reports the location information to the AMF. This location information can be the identifier information of the cell where the terminal is currently located.

[0335] S1302, SMF determines that the current access network equipment does not support multicast / broadcast services.

[0336] S1303, SMF subscribes to the terminal's location information from AMF.

[0337] Optionally, when the SMF receives a join request from a terminal, if the SMF determines that the current access network device does not support multicast / broadcast functions, the SMF subscribes to the terminal's location information from the AMF. It should be understood that this join request can be made via control plane signaling, such as a PDU session modification / establishment request, or via user plane join requests, such as an Internet Group Management Protocol (IGMP) join, multicast listener discovery (MLD), or multicast listener report (MLR).

[0338] Optionally, if the SMF determines that the current access network device does not support multicast / broadcast functions, and the multicast / broadcast service area established by the access network device includes one or more or all cells under the access network device, then the SMF subscribes to the location information of the terminal from the AMF.

[0339] Optionally, if the SMF determines that the current access network device does not support multicast / broadcast functions, the SMF will subscribe to the terminal's location information from the AMF.

[0340] Alternatively, when the SMF receives the multicast / broadcast service establishment instruction sent by the MB-SMF, the SMF subscribes to the location information of the terminal from the AMF.

[0341] Another possible approach is that when the SMF receives an instruction from the UDR or PCF to establish / modify a multicast / broadcast service, the SMF subscribes to the AMF for the location information of the terminal.

[0342] Alternatively, when the SMF receives a PDU session modification / establishment request from the UDR, PCF, or UDM, the SMF subscribes to the terminal's location information from the AMF.

[0343] It should be noted that the above-mentioned triggering of SMF to subscribe to the terminal's location information from AMF is only an example and not a limitation. It should be understood that when the terminal is moving, there may be times or other conditions that may trigger this.

[0344] S1304, AMF sends UE location information to SMF.

[0345] Specifically, after receiving the subscription message, the AMF can return a first message to the SMF, which carries the terminal's location information.

[0346] S1305, the SMF initiates the release of the terminal's first transmission resources.

[0347] Specifically, based on the current UE's location information, for access network devices that do not support multicast / broadcast functions or when the UE moves out of the multicast / broadcast service area, the QoS flow corresponding to the multicast / broadcast service is released in the PDU session associated with the multicast / broadcast service.

[0348] It should be understood that releasing the QoS stream corresponding to the multicast / broadcast service can also be understood as deleting the QoS stream corresponding to the multicast / broadcast service.

[0349] The communication method for multicast / broadcast services provided in this application, when the network device determines that the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service, triggers / initiates the release of the first transmission resources for deleting the terminal, which can effectively save network resources and avoid resource waste caused by invalid forwarding.

[0350] like Figure 14 As shown in the figure, this embodiment provides a schematic flowchart of a terminal performing a handover in a non-co-located cell N2.

[0351] It should be noted that PDU sessions associated with multicast / broadcast services can also be called unicast fall-back PDU sessions, or PDU sessions for 5GC shared delivery method to individual delivery method switch, or 5GC individual MBS traffic delivery method, or PDU sessions corresponding to 5GC individual delivery method, or PDU sessions corresponding to individual delivery method.

[0352] The PDU session context update request can be Nsmf_PDU Session_UpdateSMContextRequest.

[0353] Specifically, the PDU session context update request may include the PDU session identification information, the T-AMF identification information, the target cell identification information (Target ID) selected by the source base station for the UE to be handed over, and SM N2 information (N2 SMInformation).

[0354] S1409, SMF determines that the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service.

[0355] The reference location can be the terminal's location information under its T-gNB, which can be the target cell identifier (Target ID), the T-gNB identifier, the target tracking area identifier, etc.

[0356] It should be understood that this location information is sent from T-AMF to SMF via S1405.

[0357] Since the SMF knows that the PDU session is associated with the multicast / broadcast service when the UE joins the multicast / broadcast session service, the SMF determines that the terminal's reference location is outside the service area of ​​the first multicast / broadcast service when any one or more of the following conditions are met.

[0358] It should be noted that the following determination conditions are simply distinguished based on whether the first multicast / broadcast service is established on the T-gNB or whether the location area corresponding to the identifier information of the target cell is within the service area of ​​the multicast / broadcast service already established on the T-gNB.

[0359] 1. The multicast / broadcast service has not yet been established (or exists, is distributed, or started) on the T-gNB, or the multicast / broadcast service has been established on the T-gNB, but the terminal's location information under its T-gNB is not within the service area of ​​the multicast / broadcast service that has been established on the T-gNB.

[0360] The phrase "not established" can also be understood as "not existing," "not distributed," or "not started."

[0361] Optionally, if the SMF does not store the multicast / broadcast context information corresponding to the multicast / broadcast service joined by the terminal in the S-gNB, the SMF sends a first message to the UDR / UDM / PCF. This first message queries the multicast / broadcast context information (or multicast / broadcast session context, multicast / broadcast service context, or multicast / broadcast group context) corresponding to the multicast / broadcast service (or session or group) joined by the terminal in the S-gNB. The UDR / UDM / PCF returns the multicast / broadcast context information corresponding to the multicast / broadcast service joined by the terminal in the S-gNB. The SMF determines, through judgment (or perception or discovery), that the terminal's location information under its T-gNB is not within the service area specified in the multicast / broadcast context information corresponding to the multicast / broadcast service joined by the terminal in the S-gNB.

[0362] It should be noted that the first message may include the identification information corresponding to the multicast / broadcast service, and may also include the area session ID (also known as the local area ID, multicast / broadcast session ID, or flow ID) of the service area corresponding to the multicast / broadcast service.

[0363] This context may include identification information for the multicast / broadcast service. For example, it may include at least one of the following: the multicast / broadcast service ID, the multicast / broadcast service name, the multicast (or multicast) / broadcast address of the multicast / broadcast service, the multicast (or multicast) / broadcast IP address of the multicast / broadcast service, the TMGI corresponding to the multicast / broadcast service, and the session ID (multicast / broadcast service session ID, MBSsession ID) of the multicast / broadcast service. This context may also include service area information corresponding to the multicast / broadcast service. For example, it can refer to geographical area information (i.e., one or more geographical areas), or at least one of the following location criteria: PLMN (which can refer to one or more PLMNs), TAI (which can refer to one or more TAIs), base station identification information (which can refer to one or more, without limitation), cell identification information (identification information of one or more cells), tracking area identification information (identification information of one or more tracking areas), etc., the identification information of the centralized (or central) unit (CU) of the base station, the identification information of the distributed unit (DU) of the base station, and can also be a civil address list, etc. This context can also include the area session identifier of the service area corresponding to the multicast / broadcast service, where the area session identifier of the service area corresponding to the multicast / broadcast service can be the area session ID of the service area corresponding to the multicast / broadcast service, or it can also be called the local area ID, multicast / broadcast session ID, or flow ID, etc.

[0364] Optionally, the SMF stores the multicast / broadcast context information corresponding to the multicast / broadcast service joined by the terminal in the S-gNB. The SMF determines that the location information of the terminal under its T-gNB is not within the service area of ​​the multicast / broadcast context information corresponding to the multicast / broadcast service joined by the terminal in the S-gNB.

[0365] Optionally, the SMF can send a second message to the UDR / UDM / PCF to query the multicast / broadcast context information corresponding to the terminal's location information under its T-gNB. The UDR / UDM / PCF returns the multicast / broadcast context information corresponding to the terminal's location information under its T-gNB. The SMF determines that the area session identifier in the multicast / broadcast context information corresponding to the terminal's location information under its T-gNB is different from the area session identifier in the multicast / broadcast context information corresponding to the multicast / broadcast service joined by the terminal in the S-gNB.

[0366] Optionally, the SMF determines that the terminal's location information under its T-gNB is only within the service area of ​​the multicast / broadcast context information corresponding to the multicast / broadcast service that the terminal joined in the S-gNB.

[0367] Optionally, the SMF determines that the terminal's location information under its T-gNB is only within the service area of ​​the multicast / broadcast context information corresponding to the terminal's location information under its T-gNB.

[0368] Optionally, the SMF determines that the area session identifier in the multicast / broadcast context information corresponding to the terminal's location information under its T-gNB is different from the area session identifier in the multicast / broadcast context information corresponding to the multicast / broadcast service joined by the terminal in the S-gNB, and also different from the area session identifier in the multicast / broadcast context information corresponding to the same multicast / broadcast service on the T-gNB. It should be noted that the SMF can send a third message to the UDR / UDM / PCF to query the multicast / broadcast context information corresponding to the T-gNB's identifier information.

[0369] 2. The multicast / broadcast service has been established on the T-gNB, and the terminal's location information under its T-gNB is within the service area of ​​the multicast / broadcast service already established on the T-gNB. That is, the terminal's location information under its T-gNB is included in the service area of ​​the corresponding context information of the multicast / broadcast service already established on the T-gNB.

[0370] Optionally, the SMF determines that the terminal's location information under its T-gNB is not within the service area of ​​the multicast / broadcast context information corresponding to the multicast / broadcast service that the terminal joined under the S-gNB.

[0371] Optionally, the SMF determines that the service area of ​​the context information corresponding to the multicast / broadcast service joined by the terminal in the S-gNB is different from the service area of ​​the context information corresponding to the multicast / broadcast service when or after the T-gNB is established.

[0372] Optionally, the SMF determines that the service area of ​​the context information corresponding to the multicast / broadcast service joined by the terminal in the S-gNB is different from the service area of ​​the context information corresponding to the multicast / broadcast service when or after the T-gNB is established.

[0373] Optionally, the SMF determines that the area session identifier in the multicast / broadcast context information corresponding to the multicast / broadcast service joined by the terminal in the S-gNB is different from the area session identifier in the context information corresponding to the T-gNB when it was established or after its establishment.

[0374] Optionally, the SMF determines that the area session identifier in the multicast / broadcast context information corresponding to the multicast / broadcast service joined by the terminal in the S-gNB is different from the area session identifier in the context information corresponding to the T-gNB when it was established or after its establishment.

[0375] Optionally, the SMF determines that the location area corresponding to the terminal's location information under its T-gNB is not within the service area of ​​the multicast / broadcast context information corresponding to the multicast / broadcast service joined by the terminal under the S-gNB.

[0376] It should be understood that the above judgment conditions are merely examples and not limitations. Any condition that can be used to determine that the terminal's location information under its T-gNB is outside the service area of ​​the first multicast / broadcast / broadcast service should be within the scope of protection of this application. In addition, the above conditions can be combined in one or more ways, and this application does not limit this.

[0377] S1411, SMF sends a PDU session context update response message to T-AMF.

[0378] Specifically, when the SMF determines through conditions that the location information of the terminal under its T-gNB is not in the service area of ​​the first multicast / broadcast service, the SMF initiates the release of the terminal's first transmission resources.

[0379] Optionally, the QoS information of the unicast QoS stream of the PDU session in the PDU session context update response message sent by the SMF to the T-AMF does not include the unicast QoS stream information mapped by the first multicast / broadcast QoS stream. In other words, when the SMF determines that the T-gNB is not within the service area of ​​the first multicast / broadcast service, the SMF will not create the QoS stream corresponding to the first multicast / broadcast service. Therefore, the SMF will not notify the T-gNB to configure / prepare / establish the radio resources corresponding to the QoS stream of the first multicast / broadcast service.

[0380] Optionally, the SMF can notify the terminal's T-gNB that the first transmission resource is invalid via the T-AMF.

[0381] Optionally, the SMF can notify the terminal's T-gNB via the T-AMF not to establish / prepare the radio resources corresponding to the first transmission resource.

[0382] Optionally, the SMF can prevent the T-AMF from sending the identifier of the first transmission resource to the terminal's T-gNB. Specifically, since access network equipment allocates air interface resources based on the QoS parameters corresponding to the QFI, that is, mapping the QFI to the data radio bearer (DRB), one DRB identifier corresponds to a complete set of air interface resource configurations for the identified Data Radio Bearer. Therefore, the session management function network element does not send the QFI identifier to the base station, so that the T-gNB does not allocate a DRB for that QFI.

[0383] The explanation is as follows: SMF initiates the release of the first transmission resource of the terminal.

[0384] (1) If the PDU session associated with the multicast / broadcast service contains only the unicast QoS flow mapped by the multicast / broadcast QoS flow.

[0385] The SMF notifies the terminal's T-gNB to release the first transmission resource, which may include one or more of the following operations:

[0386] Optionally, the SMF may not forward PDU sessions associated with multicast / broadcast services (or the SMF may disable forwarding of PDU sessions associated with multicast / broadcast services). For example, based on the hierarchical structure of information cells Handover Request defined in 3GPP TS38.413, the SMF can achieve this by performing corresponding operations on the information cell Data Forwarding Not Possible.

[0387] Optionally, the SMF does not include the mapped unicast QoS flow in the list of QoS flows that need to establish related air interface resources with the T-gNB. For example, the SMF does not include the QoS Flow Setup RequestItem corresponding to the mapped unicast QoS flow in the QoS Flow Setup Request List.

[0388] Optionally, the SMF includes the QoS Flow Setup Request Item corresponding to the mapped unicast QoS flow in the QoS Flow Setup Request List, but the SMF does not populate the QoS Flow Identifier and QoS Flow Level QoS Parameters. Alternatively, the SMF does not populate the QoS Flow Identifier, QoS Flow Level QoS Parameters, or E-RAB ID. Or, the SMF does not populate the QoS Flow Identifier. Or, the SMF does not populate the QoS Flow Level QoS Parameters. Or, the SMF does not populate the E-RAB ID, etc.

[0389] It should be understood that the above parameter filling can be, for example, the actual parameter corresponding to the formal parameter, the actual parameter corresponding to the variable, the actual value corresponding to the information element, or the value corresponding to the field, etc.

[0390] (2) If the PDU session associated with the multicast / broadcast service contains not only the unicast QoS flow mapped by the multicast / broadcast QoS flow, but also other unicast QoS flows.

[0391] The SMF notifies the terminal's T-gNB to release the first transmission resource, and the aforementioned SMF-initiated release of the terminal's first transmission resource also applies. It may also include one or more of the following operations:

[0392] Optionally, the SMF may not include the mapped unicast QoS flow in the list of QoS flows that need to establish relevant air interface resources on the T-gNB. For example, the SMF may not include the QoS Flow Setup Request Item corresponding to the mapped unicast QoS flow in the QoS Flow Setup Request List.

[0393] Optionally, the SMF includes the QoS Flow Setup Request Item corresponding to the mapped unicast QoS flow in the QoS Flow Setup Request List, but the SMF does not populate the QoS Flow Identifier and QoS Flow Level QoS Parameters. Alternatively, the SMF does not populate the QoS Flow Identifier, QoS Flow Level QoS Parameters, and E-RAB identifier. Alternatively, the SMF does not populate the QoS Flow Identifier. Alternatively, the SMF does not populate the QoS Flow Level QoS Parameters. Alternatively, the SMF does not populate the E-RAB identifier, etc.

[0394] It should be understood that the above parameter filling can be, for example, the actual parameter corresponding to the formal parameter, the actual parameter corresponding to the variable, the actual value corresponding to the information element, or the value corresponding to the field, etc.

[0395] It should be noted that PDU sessions associated with multicast / broadcast services can also be called unicast fall-back PDU sessions, or PDU sessions for 5GC shared delivery method to individual delivery method switch, or 5GC individual MBS traffic delivery method, or PDU sessions corresponding to 5GC individual delivery method, or PDU sessions corresponding to individual delivery method.

[0396] It should be understood that the above-mentioned conditions are merely examples and not limitations. Any condition that can be used to determine that the reference location of the terminal is outside the service area of ​​the first multicast / broadcast / broadcast service should be within the scope of protection of this application. Furthermore, the above conditions can be combined in one or more ways, and this application does not limit this.

[0397] It should be noted that the above Figure 14 The other steps in the process are not described in detail. These steps should be understood as existing technology in N2 switching and will not be elaborated further.

[0398] The communication method for multicast / broadcast services provided in this application, if the SMF determines that the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service, the SMF notifies the target access network device of the terminal to initiate the release of the terminal's first transmission resources, which can effectively save network resources and avoid resource waste caused by invalid forwarding.

[0399] like Figure 15 As shown, this embodiment provides a schematic flowchart of a terminal performing a handover in a non-co-located cell Xn. Figure 15 During the Xn handover process shown, the SMF obtains the location information (UE Location Information) of the access network device currently providing services to the terminal. That is, the access network device providing services to the terminal at this time is the target access network device, and the SMF notifies the UPF to release the first transmission resource.

[0400] Specifically, the following steps are involved:

[0401] S1507, AMF sends a PDU session context update request to SMF.

[0402] The PDU session context update request includes the UE's reference location information (e.g., UE LocationInformation). This reference location information may be the location information of the access network device currently providing services to the terminal. This location information may be one or more of the following: the identifier of the current serving cell, the identifier of the current serving access network device, or the identifier of the current tracking area.

[0403] S1511, SMF determines that the terminal's reference location information is outside the service area of ​​the first multicast / broadcast service.

[0404] Specifically, the SMF determines that the terminal is located outside the service area of ​​the first multicast / broadcast service based on the service area information of the first multicast / broadcast service in the context corresponding to the first multicast / broadcast service, as well as the reference location information.

[0405] The following is a detailed explanation of how SMF determines that the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service.

[0406] It should be noted that the following determination criteria are simply distinguished based on whether the first multicast / broadcast service is established on the T-gNB or whether the UE's reference location information (e.g., UE Location Information) is within the service area of ​​the multicast / broadcast service already established on the T-gNB.

[0407] 1. The multicast / broadcast service has not yet been established in the T-gNB, or the multicast / broadcast service has been established in the T-gNB, but the location information (e.g., UE Location Information) of the terminal under the access network equipment currently providing services to it is not within the service area of ​​the multicast / broadcast service that has been established in the T-gNB.

[0408] Optionally, if the SMF does not store the multicast / broadcast context information corresponding to the multicast / broadcast services joined by the terminal in the S-gNB, the SMF sends a first message to the UDR / UDM / PCF to query the multicast / broadcast context information corresponding to the multicast / broadcast services joined by the terminal in the S-gNB. The UDR / UDM / PCF returns the multicast / broadcast context information corresponding to the multicast / broadcast services joined by the terminal in the S-gNB. The SMF determines that the location information of the terminal under the access network device currently providing services to it is not within the service area of ​​the multicast / broadcast context information corresponding to the multicast / broadcast services joined by the terminal in the S-gNB.

[0409] Optionally, the SMF stores the multicast / broadcast context information corresponding to the multicast / broadcast services joined by the terminal in the S-gNB. The SMF determines the location information of the terminal under the access network device currently providing services to it, and finds that it is not within the service area of ​​the multicast / broadcast context information corresponding to the multicast / broadcast services joined by the terminal in the S-gNB.

[0410] Optionally, the SMF can send a second message to the UDR / UDM / PCF to query the terminal's location information and corresponding multicast / broadcast context information under the access network device currently providing services to it. The UDR / UDM / PCF returns the multicast / broadcast context information corresponding to the terminal's location information under the access network device currently providing services to it. The SMF determines that the area session identifier in the multicast / broadcast context information corresponding to the terminal's location information under the access network device currently providing services to it is different from the area session identifier in the multicast / broadcast context information corresponding to the multicast / broadcast service joined by the terminal in the S-gNB.

[0411] Optionally, the SMF determines the terminal's location information under the access network device currently providing services to it, and this determination is only made within the service area of ​​the multicast / broadcast context information corresponding to the multicast / broadcast service that the terminal joined in the S-gNB.

[0412] Optionally, the SMF determines the terminal's location information under the access network device currently providing services to it, only within the service area of ​​the multicast / broadcast context information corresponding to the terminal's location information under its T-gNB.

[0413] Optionally, the SMF determines that the area session identifier in the multicast / broadcast context information corresponding to the terminal's location information under the access network device currently providing services to it is different from the area session identifier in the multicast / broadcast context information corresponding to the multicast / broadcast service joined by the terminal in the S-gNB, and also different from the area session identifier in the multicast / broadcast context information corresponding to the same multicast / broadcast service in the T-gNB. It should be noted that the SMF can send a third message to the UDR / UDM / PCF to query the multicast / broadcast context information corresponding to the identifier information of the T-gNB.

[0414] 2. The multicast / broadcast service has been established on the T-gNB, and the terminal's location information under the access network device currently providing services to it is within the service area of ​​the multicast / broadcast service already established on the T-gNB. That is, the terminal's location information under the access network device currently providing services to it is included in the service area of ​​the corresponding context information of the multicast / broadcast service already established on the T-gNB.

[0415] Optionally, the SMF determines that the location information of the terminal under the access network device currently providing services to it is not within the service area of ​​the multicast / broadcast context information corresponding to the multicast / broadcast service that the terminal joined in the S-gNB.

[0416] Optionally, the SMF determines that the service area of ​​the context information corresponding to the multicast / broadcast service joined by the terminal in the S-gNB is different from the service area of ​​the context information corresponding to the multicast / broadcast service when or after the T-gNB is established.

[0417] Optionally, the SMF determines that the service area of ​​the context information corresponding to the multicast / broadcast service joined by the terminal in the S-gNB is different from the service area of ​​the context information corresponding to the multicast / broadcast service when or after the T-gNB is established.

[0418] Optionally, the SMF determines that the area session identifier in the multicast / broadcast context information corresponding to the multicast / broadcast service joined by the terminal in the S-gNB is different from the area session identifier in the context information corresponding to the T-gNB when it was established or after its establishment.

[0419] Optionally, the SMF determines that the area session identifier in the multicast / broadcast context information corresponding to the multicast / broadcast service joined by the terminal in the S-gNB is different from the area session identifier in the context information corresponding to the T-gNB when it was established or after its establishment.

[0420] Optionally, the SMF determines that the location area corresponding to the location information of the terminal under the current access network device providing services is not within the service area of ​​the multicast / broadcast context information corresponding to the multicast / broadcast service joined by the terminal in the S-gNB.

[0421] It should be understood that the above-mentioned conditions are merely examples and not limitations. Any condition that can be used to determine the location information (e.g., UE Location Information) of the terminal under the current access network equipment providing services to it, and that is located outside the service area of ​​the first multicast / broadcast / broadcast service, should be within the scope of protection of this application. Furthermore, the above conditions can be combined in one or more ways, and this application does not limit this.

[0422] S1512, SMF sends an N4 session update / modification request to UPF.

[0423] Specifically, the SMF sends an N4 session update / modification request to the UPF, which contains indication information to notify the UPF to release the first transmission resource.

[0424] In summary, during the Xn handover process, when the SMF determines that the terminal's location information under its current access network device (i.e., the location information under the target base station, i.e., the UE Location Information brought up in S1507) is not within the service area of ​​the first multicast / broadcast service, the SMF notifies the UPF to release / delete / de-enable the first transmission resource by sending an N4 session update / modification request or a PFCP session update / modification request to the UPF. The N4 session update / modification request does not contain the PDR corresponding to the QoS flow of the first multicast / broadcast service, and may not contain one or more of FAR, QER, and URR.

[0425] Specifically, the SMF releases the first transport resource by sending an N4 session update / modification request or a PFCP session update / modification request to the UPF, which may include one or more of the following operations:

[0426] (1) If the PDU session associated with the multicast / broadcast service contains not only the unicast QoS flow mapped by the multicast / broadcast QoS flow, but also other unicast QoS flows.

[0427] The hierarchical structure of information cells Path Switch Request Transfer as defined in 3GPP TS 29.502 and 38.413. Optionally, if the QoS Flow Accept List of the Path Switch Request Transfer contains a unicast QoS flow mapped to the multicast / broadcast QoS flow, the SMF will delete (or release or empty) the item corresponding to the multicast / broadcast QoS flow from the QoS Flow Accept List.

[0428] Optionally, if the "QoS Flow Accept List" of the "Path Switch Request Transfer" contains the unicast QoS flow mapped by the multicast / broadcast QoS flow, then the SMF will set the parameter contained in the item corresponding to the multicast / broadcast QoS flow, namely, the "QoS Flow Identifier", to empty.

[0429] Optionally, if the "QoS Flow Accept List" of the "Path Switch Request Transfer" contains the unicast QoS flow mapped by the multicast / broadcast QoS flow, then the SMF will not establish, add, modify, or update the PDR(s), FAR(s), etc. corresponding to the multicast / broadcast QoS flow when establishing, adding, modifying, or updating the PFCP session context, or will not provide the PDR(s), FAR(s), etc. corresponding to the multicast / broadcast QoS flow to the PSA-UPF / UPF.

[0430] Optionally, if the "QoS Flow Accept List" of the "Path Switch Request Transfer" contains the unicast QoS flow mapped by the multicast / broadcast QoS flow, then the SMF will not establish, add, modify, or update the PDR(s) corresponding to the multicast / broadcast QoS flow when establishing, adding, modifying, or updating the PFCP session context, or will not provide the PDR(s) corresponding to the multicast / broadcast QoS flow to the PSA-UPF / UPF.

[0431] Optionally, if the "QoS Flow Accept List" of the "Path Switch Request Transfer" contains the unicast QoS flow mapped by the multicast / broadcast QoS flow, then the SMF will not establish, add, modify, or update the PDR(s), FAR(s), QER(s), etc. corresponding to the multicast / broadcast QoS flow before or after establishing, adding, modifying, or updating the PFCP session context, or will not provide the PDR(s), FAR(s), QER(s), etc. corresponding to the multicast / broadcast QoS flow to the PSA-UPF / UPF.

[0432] Optionally, if the "QoS Flow Accept List" of the "Path Switch Request Transfer" contains the unicast QoS flow mapped by the multicast / broadcast QoS flow, then the SMF will not establish, add, modify, or update the PDR(s), FAR(s), QER(s), URR(s), etc. corresponding to the multicast / broadcast QoS flow before or after establishing, adding, modifying, or updating the PFCP session context, or will not provide the PDR(s), FAR(s), QER(s), URR(s), etc. corresponding to the multicast / broadcast QoS flow to the PSA-UPF / UPF.

[0433] Optionally, if the "QoS Flow Accept List" of the "Path Switch Request Transfer" contains the unicast QoS flow mapped by the multicast / broadcast QoS flow, then the SMF will not establish, add, modify, or update the PDR(s) corresponding to the multicast / broadcast QoS flow before or after establishing, adding, modifying, or updating the PFCP session context, or will not provide the PDR(s) corresponding to the multicast / broadcast QoS flow to the PSA-UPF / UPF.

[0434] Optionally, if the "QoS Flow Accept List" of the "Path Switch Request Transfer" contains the unicast QoS flow mapped by the multicast / broadcast QoS flow, then the SMF will not establish, add, modify, or update the PDR(s) and FAR(s) corresponding to the multicast / broadcast QoS flow before or after establishing, adding, modifying, or updating the PFCP session context, or will not provide the PDR(s) and FAR(s) corresponding to the multicast / broadcast QoS flow to the PSA-UPF / UPF.

[0435] Optionally, if the "QoS Flow Accept List" of the "Path Switch Request Transfer" contains the unicast QoS flow mapped by the multicast / broadcast QoS flow, then the SMF will not establish, add, modify, or update the PDR(s), FAR(s), and QER(s) corresponding to the multicast / broadcast QoS flow before or after establishing, adding, modifying, or updating the PFCP session context, or will not provide the PDR(s), FAR(s), and QER(s) corresponding to the multicast / broadcast QoS flow to the PSA-UPF / UPF.

[0436] Optionally, if the "QoS Flow Accept List" of the "Path Switch Request Transfer" contains the unicast QoS flow mapped by the multicast / broadcast QoS flow, then the SMF will not establish, add, modify, or update the PDR(s), FAR(s), QER(s), and URR(s) corresponding to the multicast / broadcast QoS flow before or after establishing, adding, modifying, or updating the PFCP session context, or will not provide the PDR(s), FAR(s), QER(s), and URR(s) corresponding to the multicast / broadcast QoS flow to the PSA-UPF / UPF.

[0437] (2) If the PDU session associated with the multicast / broadcast service contains only the unicast QoS flow mapped by the multicast / broadcast QoS flow, the above-mentioned SMF-initiated release of the terminal's first transmission resources also applies.

[0438] It should be noted that in this article, the PDU session associated with multicast / broadcast services can also be called a unicast fall-back PDU session, a PDU session used for the 5GC shared delivery method to individual delivery method switch, a PDU session corresponding to the 5GC individual delivery method, or a PDU session corresponding to the individual delivery method.

[0439] It should be noted that the above Figure 15 The other steps in the process are not described in detail. These steps should be understood as existing techniques in Xn switching and will not be elaborated further.

[0440] The communication method for multicast / broadcast services provided in this application, if the SMF determines that the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service, the SMF notifies the UPF to initiate the release of the terminal's first transmission resources, which can effectively save network resources and avoid resource waste caused by invalid forwarding.

[0441] Second, the method 1200 will be explained using an S-gNB network device as an example.

[0442] First, let's explain the application scenarios in N2 handover, such as... Figure 16 As shown. In this scenario, it can be applicable to a situation where the S-gNB supports multicast / broadcast functions but the T-gNB does not, or a situation where both the S-gNB and T-gNB support multicast / broadcast functions, or a situation where the S-gNB does not support multicast / broadcast functions but the T-gNB does.

[0443] Specifically, the switch may include the following steps:

[0444] S1601, the UE sends a measurement report to the S-gNB. Correspondingly, the S-gNB receives the measurement report, determines the target cell, and decides to hand over the UE to the T-gNB where the target cell is located.

[0445] S1602, the S-gNB determines that the UE's reference location information is not within the service area of ​​the first multicast / broadcast service. This reference location information can be the terminal's location information under its T-gNB, which may include the identifier of the target cell, the identifier of the T-gNB, the identifier of the target tracking area, etc.

[0446] Specifically, after the S-gNB selects a target cell, since the S-gNB stores the service area in the context information corresponding to the first multicast / broadcast service joined by the terminal in the S-gNB, the S-gNB can determine that the terminal's location information in its target cell is not in the service area of ​​the first multicast / broadcast service.

[0447] Next, the S-gNB notifies the SMF to release or delete the first transmission resource via S1603 to S1606.

[0448] Specifically, the S-gNB operates based on the Handover Required information cells in the hierarchical structure defined in 3GPP TS38.413, and can be implemented in one or more of the following ways, without limitation:

[0449] (1) If the PDU session associated with the multicast / broadcast service contains only the unicast QoS flow mapped by the multicast / broadcast QoS flow.

[0450] Optionally, the S-gNB does not include the information cell "DL forwarding" in the QoS Flow Information Item corresponding to the unicast QoS flow mapped by the multicast / broadcast QoS flow.

[0451] Optionally, the S-gNB includes the information cell "DL forwarding" in the QoS Flow Information Item corresponding to the unicast QoS flow mapped by the multicast / broadcast QoS flow, but does not set the unicast QoS flow mapped by the multicast / broadcast QoS flow as a proposed (or suggested) downlink forwarding (according to 3GPP TS 38413, its English description is "it is set to "DL forwarding proposed").

[0452] Optionally, the S-gNB includes the information cell "DL forwarding" in the QoS Flow Information Item corresponding to the unicast QoS flow mapped by the multicast / broadcast QoS flow, but does not populate the parameters for DL ​​forwarding.

[0453] It should be noted that the unicast QoS flow mapped to the multicast / broadcast QoS flow mentioned above can be understood as the unicast QoS flow corresponding to the multicast / broadcast QoS flow.

[0454] It should be understood that the above parameter filling can be, for example, the actual parameter corresponding to the formal parameter, the actual parameter corresponding to the variable, the actual value corresponding to the information element, or the value corresponding to the field, etc.

[0455] (2) If the PDU session associated with the multicast / broadcast service contains not only the unicast QoS flow mapped by the multicast / broadcast QoS flow, but also other unicast QoS flows, in addition to the methods described above, the S-gNB can also perform the following operations. Note that the following operations are not exhaustive and are not limited:

[0456] S-gNB can also omit any QoS Flow Information Item from the QoS Flow Information List or leave the QoS Flow Information List empty.

[0457] It should be noted that in this article, the PDU session associated with multicast / broadcast services can also be called a unicast fall-back PDU session, a PDU session used for the 5GC shared delivery method to individual delivery method switch, a PDU session corresponding to the 5GC individual delivery method, or a PDU session corresponding to the individual delivery method.

[0458] It should be noted that the above Figure 16 The other steps in the process are not described in detail. These steps should be understood as existing technology in N2 switching and will not be elaborated further.

[0459] The communication method for multicast / broadcast services provided in this application, if the S-gNB determines that the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service, the S-gNB notifies the SMF to initiate the release of the terminal's first transmission resources, which can effectively save network resources and avoid resource waste caused by invalid forwarding.

[0460] Next, we will explain the application of S-gNB network devices in Xn handover scenarios, such as... Figure 17 As shown. In this scenario, it can be applicable to situations where the S-gNB supports multicast / broadcast functions, but the T-gNB does not.

[0461] S1701, the UE sends a measurement report to the S-gNB. The S-gNB receives the measurement report, determines the target cell, and decides to hand over the UE to the T-gNB where the target cell is located.

[0462] S1702, the S-gNB determines that the UE's reference location information is not within the service area of ​​the first multicast / broadcast service. This reference location information can be the terminal's location information under its T-gNB, which may include the identifier of the target cell, the identifier of the T-gNB, the identifier of the target tracking area, etc.

[0463] Specifically, after the S-gNB selects a target cell, since the S-gNB stores the service area in the context information corresponding to the first multicast / broadcast service joined by the terminal in the S-gNB, the S-gNB can determine that the terminal's location information in its target cell is not in the service area of ​​the first multicast / broadcast service.

[0464] Next, the S-gNB notifies the SMF to release or delete the first transmission resource via S1703 to S1708.

[0465] Specifically, the S-gNB operates based on the Handover Request information element in the hierarchical structure of information elements comprising Handover Request as defined in 3GPP TS38.423. For example, it can be implemented through one or more of the following methods, without limitation:

[0466] (1) If the PDU session associated with the multicast / broadcast service contains only the unicast QoS flow mapped by the multicast / broadcast QoS flow.

[0467] Optionally, the S-gNB does not include the information cell "QoS Flow Identifier" in the QoS Flows To Be Setup Item corresponding to the unicast QoS flow mapped by the multicast / broadcast QoS flow.

[0468] Optionally, the S-gNB does not include the information element "QoS Flow Level QoS Parameters" in the QoS Flows To Be Setup Item corresponding to the unicast QoS flow mapped by the multicast / broadcast QoS flow.

[0469] Optionally, the S-gNB does not include the information element "QoSFlows To Be Setup Item" corresponding to the unicast QoS flow mapped by the multicast / broadcast QoS flow in the "QoS Flows To Be Setup List".

[0470] Optionally, the S-gNB includes the information cell "QoS Flow Identifier" in the QoS Flows To Be Setup Item corresponding to the unicast QoS flow mapped by the multicast / broadcast QoS flow, but does not populate the QoS Flow Identifier with parameters.

[0471] Optionally, the S-gNB includes the information cell "QoS Flow Level QoS Parameters" in the QoS Flows To Be Setup Item corresponding to the unicast QoS flow mapped by the multicast / broadcast QoS flow, but does not populate the "QoS Flow Level QoS Parameters" with parameters.

[0472] Optionally, the S-gNB includes the information cell "QoSFlows To Be Setup Item" corresponding to the unicast QoS flow mapped by the multicast / broadcast QoS flow in the "QoS Flows To Be Setup List", but does not populate the "QoSFlows To Be Setup Item" with parameters.

[0473] It should be understood that the above parameter filling can be, for example, the actual parameter corresponding to the formal parameter, the actual parameter corresponding to the variable, the actual value corresponding to the information element, or the value corresponding to the field, etc.

[0474] (2) If the PDU session associated with the multicast / broadcast service contains not only the unicast QoS flow mapped by the multicast / broadcast QoS flow, but also other unicast QoS flows, in addition to the methods described above, the S-gNB can also perform the following operations:

[0475] Optionally, the S-gNB does not include any "QoS Flows ToBe Setup Item" in the "QoS Flows To Be Setup List".

[0476] Optionally, the S-gNB includes a "QoS Flows To Be Setup Item" in the "QoS Flows To Be Setup List" corresponding to the unicast QoS flow mapped by the multicast / broadcast QoS flow, but does not populate the "QoS Flows To Be Setup Item" with parameters.

[0477] Optionally, the S-gNB does not include the information element "QoS Flows To Be Setup List" in "PDU Session Resources To Be Setup Item".

[0478] Optionally, the S-gNB includes the information element "QoSFlows To Be Setup List" in "PDU Session Resources To Be Setup Item", but does not populate the parameters of "QoS Flows To Be Setup List".

[0479] Optionally, the S-gNB does not include the information element "PDU Session Resources To Be Setup Item" in the "PDU Session Resources To Be Setup List".

[0480] Optionally, the S-gNB includes the information element "PDU Session Resources To Be Setup Item" in the "PDU Session Resources To Be Setup List", but does not populate the parameters for "PDU Session Resources To Be Setup Item".

[0481] It should be noted that PDU sessions associated with multicast / broadcast services can also be called unicast fall-back PDU sessions, or PDU sessions for 5GC shared delivery method to individual delivery method switch, or 5GC individual MBS traffic delivery method, or PDU sessions corresponding to 5GC individual delivery method, or PDU sessions corresponding to individual delivery method.

[0482] It should be noted that the above Figure 17 The other steps in the process are not described in detail. These steps should be understood as existing techniques in Xn switching and will not be elaborated further.

[0483] The communication method for multicast / broadcast services provided in this application, if the S-gNB determines that the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service, the S-gNB notifies the SMF to initiate the release of the terminal's first transmission resources, which can effectively save network resources and avoid resource waste caused by invalid forwarding.

[0484] Figure 18 This is an illustrative flowchart of a multicast / broadcast service communication method 1800 provided in an embodiment of this application. The method 1800 includes at least the following steps:

[0485] It should be noted that this applies to scenarios where the S-gNB does not support the first multicast / broadcast service, but the T-gNB does support the first multicast / broadcast service.

[0486] Specifically, it includes the following steps:

[0487] S1810, T-gNB acquires the reference location information of the terminal, wherein the reference location information is used to characterize the reference location of the terminal.

[0488] Optionally, the T-gNB receives reference location information from the terminal via the S-gNB. This reference location information includes the terminal's location information under its T-gNB.

[0489] Optionally, the T-gNB can accept handover request information from the S-gNB, which includes the terminal's location information under the T-gNB.

[0490] S1820, the T-gNB does not accept forwarding of data from the S-gNB for the terminal's first multicast / broadcast service.

[0491] Alternatively, the T-gNB may discard the forwarding of data from the S-gNB for the first multicast / broadcast service to that terminal.

[0492] Specifically, when the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service, the T-gNB will not accept / discard the forwarding of the first multicast / broadcast service data from the source access network device of the terminal for the terminal.

[0493] It should be noted that PDU sessions associated with multicast / broadcast services can also be called unicast fall-back PDU sessions, or PDU sessions for switching from 5GC shared delivery method to individual delivery method, or 5GC individual MBS traffic delivery method, or PDU sessions corresponding to 5GC individual delivery method, or PDU sessions corresponding to individual delivery method.

[0494] For example, this embodiment can be applied to Xn switching scenarios, such as... Figure 19 As shown.

[0495] Specifically, it includes the following key steps:

[0496] S1902, S-gNB sends a handover request to T-gNB.

[0497] The handover request may include the PDU session information of the UE to be handed over. This PDU session information includes a PDU session identifier and QoS information corresponding to the unicast QoS streams contained within the PDU session. If the PDU session of the UE being handed over is also associated with multicast / broadcast services, the PDU session information also includes QoS information corresponding to the QoS streams of the associated multicast / broadcast services. For example, the QoS information of a unicast QoS stream includes the unicast QFI and QoS parameters corresponding to that unicast QoS stream, while the QoS information of a multicast / broadcast service QoS stream includes the unicast QFI mapped to the multicast / broadcast QFI and the QoS parameters corresponding to that QFI.

[0498] Additionally, the handover request may include the QFI of the QoS flow that the S-gNB wants to forward to the T-gNB and the forwarding tunnel endpoint identifier generated by the S-gNB. As an example, the QoS flow that the S-gNB wants to forward to the T-gNB can be a unicast QoS flow (containing unicast QoS flows mapped from multicast / broadcast QoS flows).

[0499] In addition, according to the definition of the information element Handover Request in 3GPP TS 38.423, the handover request may also include the location information or location area of ​​the UE at the source base station (e.g., Global NG-RAN Node ID).

[0500] S1903, when the T-gNB determines that the terminal's reference location information is outside the service area of ​​the first multicast / broadcast service, the T-gNB will not accept the forwarding of data from the S-gNB for the first multicast / broadcast service of the terminal.

[0501] Specifically, if the T-gNB stores the service area in the context information corresponding to the first multicast / broadcast service joined by other terminals on the T-gNB, the T-gNB determines that the location information of the terminal on the S-gNB is not in the aforementioned service area.

[0502] According to the definition of Handover Request in 3GPP TS 38.423, the T-gNB can perform the following operations. It should be noted that the following operations are not exhaustive and are not limited:

[0503] (1) If the PDU session associated with the multicast / broadcast service contains a unicast QoS flow mapped by the multicast / broadcast QoS flow.

[0504] Optionally, T-gNB may not recommend (or not include) the item corresponding to the QoS flow in the "QoS FlowsAdmitted List".

[0505] Optionally, the T-gNB may suggest (or include) the item corresponding to the QoS flow in the "QoS Flows AdmittedList", but may not populate the parameters of the item corresponding to the QoS flow.

[0506] Optionally, T-gNB may not recommend (or not include) the item corresponding to the QoS flow in the "QoS Flows Admitted List", and T-gNB may recommend (or include) the item corresponding to the QoS flow in the "QoS Flows not Admitted List".

[0507] Optionally, T-gNB may not recommend (or not include) the item corresponding to the QoS flow in the "QoS FlowsAdmitted List", and T-gNB may not recommend (or not include) the item corresponding to the QoS flow in the "QoS FlowsAccepted For Data Forwarding List".

[0508] Optionally, T-gNB may not recommend (or not include) the item corresponding to the QoS flow in the "QoS FlowsAdmitted List", and T-gNB may recommend (or include) the item corresponding to the QoS flow in the "QoS FlowsAccepted For Data Forwarding List", but will not populate the parameters of the item corresponding to the QoS flow.

[0509] Optionally, the T-gNB may not recommend (or not include) the item corresponding to the QoS flow in the "QoS Flows Admitted List", and the T-gNB may not recommend (or not include) the item corresponding to the QoS flow in the "QoS Flows Accepted For Data Forwarding List".

[0510] Optionally, T-gNB may not recommend (or not include) the item corresponding to the QoS flow in the "QoS Flows Admitted List", and T-gNB may not recommend (or not include) the item corresponding to the QoS flow in the "QoS Flows Accepted For Data Forwarding List", and T-gNB may recommend (or include) the item corresponding to the QoS flow in the "QoS Flows Accepted For Data Forwarding List", but may not populate the parameters of the item corresponding to the QoS flow.

[0511] It should be understood that the above parameter filling can be, for example, the actual parameter corresponding to the formal parameter, the actual parameter corresponding to the variable, the actual value corresponding to the information element, or the value corresponding to the field, etc.

[0512] (2) If the PDU session associated with the multicast / broadcast service contains only the unicast QoS flow mapped by the multicast / broadcast QoS flow, in addition to the operations in method (1) above, the T-gNB can also perform the following operations. Note that the following operations are not exhaustive and are not limited:

[0513] Optionally, T-gNB will not (or recommends) include any item corresponding to this QoS flow in the HandoverRequest Acknowledge information element.

[0514] The multicast / broadcast communication method provided in this application, for Xn handover, is based on the service area in the context information of the multicast / broadcast service stored in the T-gNB and the location information of the terminal corresponding to the S-gNB. If the location information of the terminal corresponding to the S-gNB is not in the aforementioned service area, the T-gNB will not forward the QoS flow corresponding to the multicast / broadcast service or will not recommend forwarding the QoS flow corresponding to the multicast / broadcast service. Through the processing and operation of the T-gNB, this scheme can effectively save network resources and avoid the resource waste caused by invalid forwarding of multicast / broadcast service data.

[0515] Figure 20 This is an illustrative flowchart of a multicast / broadcast service communication method 2000 provided in an embodiment of this application. The method 2000 includes at least the following steps:

[0516] S2001, the T-gNB receives a notification from the SMF. This notification indicates that the terminal's first transmission resource is invalid, and this first transmission resource is used to transmit data for a first multicast / broadcast service.

[0517] S2002, the T-gNB does not establish the radio resource corresponding to the first transmission resource. Here, "the T-gNB does not establish the radio resource corresponding to the first transmission resource" can be replaced with "the T-gNB does not prepare the radio resource corresponding to the first transmission resource" or "the T-gNB does not allocate the radio resource corresponding to the first transmission resource" (i.e., it does not prepare / allocate).

[0518] Optionally, the T-gNB can also perform the following: Figure 21 In step 2102, for example, the T-gNB sends an indication message to the S-gNB of the terminal, which indicates that the T-gNB will not accept the forwarding of the data of the first multicast / broadcast service of the source access network device for the terminal.

[0519] The multicast / broadcast communication method provided in this application embodiment is based on the service area in the context information of the multicast / broadcast service stored in the T-gNB and the location information of the terminal corresponding to the S-gNB. If the location information of the terminal corresponding to the S-gNB is not in the aforementioned service area, the T-gNB will not forward the QoS flow corresponding to the multicast / broadcast service or will not recommend forwarding the QoS flow corresponding to the multicast / broadcast service. Through the processing and operation of the T-gNB, this scheme can effectively save network resources and avoid the resource waste caused by invalid forwarding of multicast / broadcast service data.

[0520] It is understood that the methods and operations implemented by the network device in the above-described method embodiments can also be implemented by components (such as chips or circuits) that can be used in the network device.

[0521] The above, combined with Figure 5 and Figure 23 The methods provided in the embodiments of this application are described in detail below. Figures 24 to 27 This application provides a detailed description of the communication apparatus for multicast / broadcast services provided in the embodiments of this application. It should be understood that the descriptions of the apparatus embodiments correspond to the descriptions of the method embodiments; therefore, any content not described in detail here will be referred to the method embodiments above, and for the sake of brevity, will not be repeated here.

[0522] This application embodiment can divide network devices or target access network devices into functional modules according to the above method examples. For example, each function can be divided into its own functional modules, or two or more functions can be integrated into one processing module. The integrated modules can be implemented in hardware or software functional modules. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods. The following description uses the division of functional modules according to their respective modules as an example.

[0523] Figure 24 This is a schematic block diagram of a communication device for multicast / broadcast services provided in an embodiment of this application. As shown in the figure, the communication device 1000 for multicast / broadcast services may include a processing module 1100 and a transceiver module 1200.

[0524] In one possible design, the communication device 1000 for the multicast / broadcast service may correspond to the network device in the above method embodiment, specifically, it may be the SMF in the above embodiment, or a chip configured in the S-gNB.

[0525] Specifically, the communication device 1000 for the multicast / broadcast service may include tools for performing... Figure 5 Method 500 or Figure 7 Method 700 or Figure 8 Method 800 or Figure 9 Method 900 or Figure 12 Method 1200 or Figure 13 Method 1300 or Figure 14 Method 1400 or Figure 15 The network device in method 1500 executes the method's modules. Furthermore, each module in the multicast / broadcast service communication device 1000 and the aforementioned other operations and / or functions are respectively for implementing... Figure 5 Method 500 or Figure 7 Method 700 or Figure 8 Method 800 or Figure 9 Method 900 or Figure 12 Method 1200 or Figure 13 Method 1300 or Figure 14 Method 1400 or Figure 15 Method 1500 or Figure 22 Method 2200 or Figure 23 The corresponding process in method 2300.

[0526] Wherein, when the communication device 1000 of the multicast / broadcast service is used to perform Figure 5 When method 500 is used, processing module 1100 can be used to execute steps 510 and 520 in method 500.

[0527] When the communication device 1000 of the multicast / broadcast service is used to perform Figure 7 When method 700 is executed, processing module 1100 can be used to execute step 720 in method 700. Transceiver module 1200 can be used to execute steps 703 and 704 in method 700.

[0528] When the communication device 1000 of the multicast / broadcast service is used to perform Figure 8 When method 800 is executed, processing module 1100 can be used to execute step 809 in method 800. Transceiver module 1200 can be used to execute steps 805-808 and step 810 in method 800.

[0529] When the communication device 1000 of the multicast / broadcast service is used to perform Figure 9 When performing method 900, processing module 1100 can be used to execute step 911 in method 900. Transceiver module 1200 can be used to execute steps 907-910 and step 912 in method 900.

[0530] When the communication device 1000 of the multicast / broadcast service is used to perform Figure 12 When using method 1200, the processing module 1100 can be used to execute steps 1201 and 1202 in method 1200.

[0531] When the communication device 1000 of the multicast / broadcast service is used to perform Figure 13 When using method 1300, processing module 1100 can be used to execute steps 1302 and 1305 in method 1300. Transceiver module 1200 can be used to execute steps 1303 and 1304 in method 1300.

[0532] When the communication device 1000 of the multicast / broadcast service is used to perform Figure 14 When method 1400 is executed, processing module 1100 can be used to execute step 1409 in method 1400. Transceiver module 1200 can be used to execute steps 1405 to 1408 and step 1410 in method 1400.

[0533] When the communication device 1000 of the multicast / broadcast service is used to perform Figure 15 When performing method 1500, the processing module 1100 can be used to execute step 1511 in method 1500. The transceiver module 1200 can be used to execute steps 1507 to 1510 and step 1512 in method 1500.

[0534] When the communication device 1000 of the multicast / broadcast service is used to perform Figure 22 When performing method 2200, processing module 1100 can be used to execute step 2209 in method 2200. Transceiver module 1200 can be used to execute steps 2205-2208 and step 2210 in method 2200.

[0535] When the communication device 1000 of the multicast / broadcast service is used to perform Figure 23When performing method 2300, processing module 1100 can be used to execute step 2309 in method 2300. Transceiver module 1200 can be used to execute steps 2305-2308 and step 2310 in method 2300.

[0536] Figure 25 This is a schematic block diagram of a communication device for multicast / broadcast services provided in an embodiment of this application. As shown in the figure, the communication device 2000 for multicast / broadcast services may include a transceiver module 2100 and a processing module 2200.

[0537] In one possible design, the communication device 2000 for the multicast / broadcast service may correspond to the network device in the above method embodiment, specifically, it may be the S-gNB in ​​the above embodiment, or a chip configured in the S-gNB.

[0538] Specifically, the communication device 2000 for the multicast / broadcast service may include tools for performing... Figure 5 Method 500 or Figure 10 Method 1000 or Figure 11 Method 1100 or Figure 12 Method 1200 or Figure 16 Method 1600 or Figure 17 The network device in method 1700 executes the method's module. Furthermore, each module in the multicast / broadcast service communication device 2000 and the aforementioned other operations and / or functions are respectively for implementing... Figure 5 Method 500 or Figure 10 Method 1000 or Figure 11 Method 1100 or Figure 12 Method 1200 or Figure 16 Method 1600 or Figure 17 The corresponding process in method 1700.

[0539] Wherein, when the communication device 1000 of the multicast / broadcast service is used to perform Figure 5 When method 500 is used, processing module 2200 can be used to execute steps 510 and 520 in method 500.

[0540] When the communication device 2000 of the multicast / broadcast service is used to perform Figure 10 When performing method 1000, the transceiver module 2100 can be used to execute steps 1001 and 1003 in method 1000. The processing module 2200 can be used to execute step 1002 in method 1000.

[0541] When the communication device 2000 of the multicast / broadcast service is used to perform Figure 11When performing method 1100, the transceiver module 2100 can be used to execute steps 1001 and 1003 in method 1100. The processing module 2200 can be used to execute step 1102 in method 1100.

[0542] When the communication device 2000 of the multicast / broadcast service is used to perform Figure 12 When using method 1200, the processing module 2200 can be used to execute steps 1201 and 1202 in method 1200.

[0543] When the communication device 2000 of the multicast / broadcast service is used to perform Figure 16 When performing method 1600, the transceiver module 2100 can be used to execute steps 1601 and 1603 in method 1600. The processing module 2200 can be used to execute step 1602 in method 1600.

[0544] When the communication device 2000 of the multicast / broadcast service is used to perform Figure 17 When performing method 1700, the transceiver module 2100 can be used to execute steps 1701 and 1703 in method 1700. The processing module 2200 can be used to execute step 1702 in method 1700.

[0545] Figure 26 This is a schematic block diagram of a communication device for multicast / broadcast services provided in an embodiment of this application. As shown in the figure, the communication device 3000 for multicast / broadcast services may include a transceiver module 3100 and a processing module 3200.

[0546] In one possible design, the communication device 3000 for the multicast / broadcast service may correspond to the target access network device in the above method embodiment, or a chip configured in the target access network device.

[0547] Specifically, the communication device 3000 for the multicast / broadcast service may include tools for performing... Figure 18 Method 1800 or Figure 19 Method 1900 or Figure 20 Method 2000 or Figure 21 The module executing the method in method 2100 of the target access network device. Furthermore, each module in the multicast / broadcast service communication device 3000 and the aforementioned other operations and / or functions are respectively for implementing... Figure 18 Method 1800 or Figure 19 Method 1900 or Figure 20 Method 2000 or Figure 21 The corresponding process in method 2100.

[0548] Among them, when the communication device 3000 of the multicast / broadcast service is used to perform Figure 18 When method 1800 is used, processing module 3200 can be used to execute steps 1810 and 1820 in method 1800.

[0549] When the communication device 3000 of the multicast / broadcast service is used to perform Figure 19 When performing method 1900, the transceiver module can be used to execute steps 1902, 1904, and 1907 in method 1900. The processing module 3200 can be used to execute step 1903 in method 1900.

[0550] When the communication device 3000 of the multicast / broadcast service is used to perform Figure 20 When using method 2000, the transceiver module can be used to execute step 2001 in method 2000. The processing module 3200 can be used to execute step 2002 in method 2000.

[0551] When the communication device 3000 of the multicast / broadcast service is used to perform Figure 21 When using method 2100, the transceiver module can be used to execute steps 2101 and 2102 in method 2100.

[0552] like Figure 27 As shown in the illustration, this application embodiment also provides a communication device 2500 for multicast / broadcast services. The multicast / broadcast communication device 2500 includes a processor 2510 coupled to a memory 2520. The memory 2520 stores computer programs or instructions and / or data. The processor 2510 executes the computer programs or instructions and / or data stored in the memory 2520, causing the methods described in the above method embodiments to be executed.

[0553] Optionally, the communication device 2500 for the multicast / broadcast service includes one or more processors 2510.

[0554] Optionally, such as Figure 17 As shown, the communication device 2500 for the multicast / broadcast service may also include a memory 2520.

[0555] Optionally, the communication device 2500 for the multicast / broadcast service may include one or more memory 2520s.

[0556] Alternatively, the memory 2520 can be integrated with the processor 2510, or it can be set separately.

[0557] Optionally, such as Figure 27As shown, the communication device 2500 for the multicast / broadcast service may further include a transceiver 2530, which is used for receiving and / or transmitting signals. For example, a processor 2510 is used to control the transceiver 2530 to receive and / or transmit signals.

[0558] As one approach, the communication device 2500 for the multicast / broadcast service is used to implement the operations performed by the network device or the target access network device in the above method embodiments.

[0559] This application also provides a computer-readable storage medium storing computer instructions for implementing the methods executed by a network device or a target access network device in the above-described method embodiments.

[0560] For example, when the computer program is executed by a computer, it enables the computer to implement the method executed by the terminal device or the method executed by the network device in the above method embodiments.

[0561] This application also provides a computer program product containing instructions that, when executed by a computer, cause the computer to implement the method executed by the terminal device or the method executed by the network device in the above method embodiments.

[0562] This application also provides a communication system for multicast / broadcast services, which includes the network device or target access network device described in the above embodiments.

[0563] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the explanations and beneficial effects of the relevant content in any of the multicast / broadcast service communication devices provided above can be referred to the corresponding method embodiments provided above, and will not be repeated here.

[0564] In this embodiment, the terminal device or network device may include a hardware layer, an operating system layer running on top of the hardware layer, and an application layer running on the operating system layer. The hardware layer may include hardware such as a central processing unit (CPU), a memory management unit (MMU), and memory (also called main memory). The operating system layer may be any one or more computer operating systems that implement business processing through processes, such as Linux, Unix, Android, iOS, or Windows. The application layer may include applications such as browsers, address books, word processing software, and instant messaging software.

[0565] This application does not impose any particular limitation on the specific structure of the execution subject of the method provided in this application embodiment. As long as it is possible to communicate according to the method provided in this application embodiment by running a program that records the code of the method provided in this application embodiment. For example, the execution subject of the method provided in this application embodiment can be a terminal device or a network device, or a functional module in a terminal device or network device that can call and execute a program.

[0566] Various aspects or features of this application may be implemented as methods, apparatus, or articles of manufacture using standard programming and / or engineering techniques. The term "article of manufacture" as used herein may encompass a computer program accessible from any computer-readable device, carrier, or medium.

[0567] The computer-readable storage medium can be any available medium that a computer can access, or a data storage device such as a server or data center that integrates one or more available media. Available media (or computer-readable media) can include, but are not limited to: magnetic media or magnetic storage devices (e.g., floppy disks, hard disks (such as portable hard drives), magnetic tapes), optical media (e.g., optical discs, compact discs (CDs), digital versatile discs (DVDs), etc.), smart cards and flash memory devices (e.g., erasable programmable read-only memory (EPROM), cards, sticks, or key drives, etc.), or semiconductor media (e.g., solid-state disks (SSDs), USB flash drives, read-only memory (ROM), random access memory (RAM), and various other media capable of storing program code).

[0568] The various storage media described herein may represent one or more devices and / or other machine-readable media used for storing information. The term "machine-readable media" may include, but is not limited to, wireless channels and various other media capable of storing, containing and / or carrying instructions and / or data.

[0569] It should be understood that the processor mentioned in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0570] It should also be understood that the memory mentioned in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM). For example, RAM can be used as an external cache. By way of example and not limitation, RAM can include a variety of forms, such as: static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0571] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA, or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component, the memory (storage module) can be integrated into the processor.

[0572] It should also be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0573] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of the apparatus or units may be electrical, mechanical, or other forms.

[0574] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to implement the solution provided in this application, depending on actual needs.

[0575] In addition, the functional units in the various embodiments of this application can be integrated into one unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0576] In the above embodiments, it can be implemented entirely or partially by software, hardware, firmware, or any combination thereof.

[0577] When implemented using software, it can be implemented entirely or partially as a computer program product. This computer program product includes one or more computer instructions. When the 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 generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. For example, the computer can be a personal computer, a server, or a network device, etc. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. For information on computer-readable storage media, please refer to the description above.

[0578] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims and the specification.

Claims

1. A communication method for multicast / broadcast services, characterized in that, include: The network device acquires reference location information of the terminal, the reference location information being used to characterize the reference location of the terminal, the reference location information including the location information of the terminal under the target access network device of the terminal; When the reference location of the terminal is within the service area of ​​the first multicast / broadcast service, the network device triggers the target access network device of the terminal to allocate transmission resources for the terminal, and the transmission resources are used to transmit the data of the first multicast / broadcast service.

2. The method according to claim 1, characterized in that, The location information is the identifier of the target cell of the terminal and / or the identifier of the target access network device.

3. The method according to claim 1, characterized in that, The network device includes a session management function network element or the source access network device of the terminal.

4. A communication method for multicast / broadcast services, characterized in that, include: The network device acquires reference location information of the terminal, the reference location information being used to characterize the reference location of the terminal, the reference location information including the location information of the terminal under the target access network device of the terminal; When the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service, the network device initiates the release of the terminal's first transmission resources, which are used to transmit data of the first multicast / broadcast service.

5. The method according to claim 4, characterized in that, The first transmission resource includes: resources for the terminal to transmit data of the first multicast / broadcast service through the target access network device of the terminal.

6. The method according to claim 4 or 5, characterized in that, The method further includes: The network device determines, based on the reference location information, that the terminal is located outside the service area of ​​the first multicast / broadcast service.

7. The method according to claim 4 or 5, characterized in that, The network device is a session management function network element, and the network device obtains the terminal's reference location information by: The session management function network element receives a first message, which includes the reference location information.

8. The method according to claim 7, characterized in that, The first message also includes the identification information of the first multicast / broadcast service.

9. The method according to claim 7, characterized in that, The first message is either a Protocol Data Unit (PDU) session context update request or a location information provision.

10. The method according to claim 7, characterized in that, The method further includes: The session management function network element subscribes to the terminal's reference location information from the access and mobility management network element; The session management function network element receives the first message, including: The session management function network element receives reference location information from the terminal from the access and mobility management network element.

11. The method according to claim 4 or 5, characterized in that, The network device is a session management function network element. The network device initiates the release of the first transmission resource, including: The session management function network element notifies the user plane function network element UPF to release the first transmission resource. And / or, The session management function network element notifies the target access network device of the terminal to release the first transmission resource.

12. The method according to claim 11, characterized in that, The session management function network element notifies the UPF to release the first transmission resource, including: The session management function network element sends an N4 session modification request or a PFCP session modification request to the UPF to notify the UPF to release the first transmission resource.

13. The method according to claim 4 or 5, characterized in that, The network device is a session management function network element, and the method further includes: The session management function network element notifies the target access network device of the terminal that the first transmission resource is invalid. or, The session management function network element notifies the target access network device of the terminal not to allocate the radio resources corresponding to the first transmission resource. or, The session management function network element does not send the identifier of the first transmission resource to the target access network device of the terminal.

14. The method according to claim 4 or 5, characterized in that, The network device is the source access network device of the terminal, and the network device initiates the release of the terminal's first transmission resources, including: The source access network device notifies the session management function network element to release the first transmission resource.

15. A communication method for multicast / broadcast services, characterized in that, include: The target access network device obtains the reference location information of the terminal, the reference location information being used to characterize the reference location of the terminal, the reference location information including the location information of the terminal under the target access network device; When the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service, the target access network device does not accept the forwarding of data of the first multicast / broadcast service for the terminal from the source access network device of the terminal.

16. The method according to claim 15, characterized in that, The target access network device obtains the terminal's reference location information, including: The target access network device receives reference location information from the terminal of the source access network device.

17. The method according to claim 15 or 16, characterized in that, The method further includes: The source access network device is notified that the target access network device does not accept the forwarding of the first multicast / broadcast service data of the source access network device for the terminal.

18. A communication apparatus for multicast / broadcast services, characterized in that, include: The processing module is used to obtain reference location information of the terminal, the reference location information being used to characterize the reference location of the terminal, the reference location information including the location information of the terminal under the target access network device of the terminal; When the reference location of the terminal is within the service area of ​​the first multicast / broadcast service, the processing module triggers the target access network device of the terminal to allocate transmission resources for the terminal, and the transmission resources are used to transmit the data of the first multicast / broadcast service.

19. The apparatus according to claim 18, characterized in that, The location information is the identifier of the target cell of the terminal and / or the identifier of the target access network device.

20. The apparatus according to claim 18 or 19, characterized in that, The device includes: a session management function network element or the source access network device of the terminal.

21. A communication device for multicast / broadcast services, characterized in that, include: The processing module is used to obtain reference location information of the terminal, the reference location information being used to characterize the reference location of the terminal, the reference location information including the location information of the terminal under the target access network device of the terminal; When the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service, the processing module initiates the release of the terminal's first transmission resources, which are used to transmit data of the first multicast / broadcast service.

22. The apparatus according to claim 21, characterized in that, The first transmission resource includes: resources for transmitting data of the first multicast / broadcast service through the target access network device of the terminal.

23. The apparatus according to claim 21 or 22, characterized in that, The processing module is further configured to determine, based on the reference location information, that the terminal is located outside the service area of ​​the first multicast / broadcast service.

24. The apparatus according to claim 21 or 22, characterized in that, The device is a session management function network element, and the device further includes: The transceiver module is used to receive a first message, the first message including the reference location information.

25. The apparatus according to claim 24, characterized in that, The first message also includes the identification information of the first multicast / broadcast service.

26. The apparatus according to claim 24, characterized in that, The first message is either a Protocol Data Unit (PDU) session context update request or a location information provision.

27. The apparatus according to claim 24, characterized in that, The transceiver module is also used to subscribe to the reference location information of the terminal from the access and mobility management network element; The transceiver module receives a first message, including: The transceiver module receives reference location information from the terminal via the access and mobility management network element.

28. The apparatus according to claim 24, characterized in that, The device is a network element with session management function. The transceiver module is also used to notify the user plane function element (UPF) to release the first transmission resource. And / or, The transceiver module is also used to notify the target access network device of the terminal to release the first transmission resource.

29. The apparatus according to claim 28, characterized in that, The transceiver module is also used to send an N4 session modification request or a Message Forwarding Control Protocol (PFCP) session modification request to the UPF to notify the UPF to release the first transmission resource.

30. The apparatus according to claim 24, characterized in that, The device is a network element with session management function. The transceiver module is also used to notify the target access network device of the terminal that the first transmission resource is invalid. or The transceiver module is further configured to notify the target access network device of the terminal not to allocate the radio resources corresponding to the first transmission resource. or, The transceiver module does not send the identifier of the first transmission resource to the target access network device of the terminal.

31. The apparatus according to claim 21 or 22, characterized in that, The device is the source access network equipment of the terminal, and the device further includes: The transceiver module is used to notify the session management function network element to release the first transmission resource.

32. A communication device for multicast / broadcast services, characterized in that, include: The processing module is used to obtain reference location information of the terminal, the reference location information being used to characterize the reference location of the terminal, the reference location information including the location information of the terminal under the target access network device of the terminal; When the reference location of the terminal is outside the service area of ​​the first multicast / broadcast service, the processing module does not accept / discard the forwarding of the first multicast / broadcast service data from the source access network device of the terminal for the terminal.

33. The apparatus according to claim 32, characterized in that, The transceiver module is used to receive reference location information of the terminal from the source access network device.

34. The apparatus according to claim 33, characterized in that, The transceiver module is further configured to notify the source access network device that the device does not accept the forwarding of the first multicast / broadcast service data of the source access network device for the terminal.

35. A communication apparatus for multicast / broadcast services, characterized in that, include: Memory, used to store computer instructions; A processor for executing computer instructions stored in the memory, causing the apparatus to perform the method as claimed in any one of claims 1 to 3, or the method as claimed in any one of claims 4 to 14, or the method as claimed in any one of claims 15 to 17.

36. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed by a communication device for multicast / broadcast services, causes the device to perform the method as described in any one of claims 1 to 3, or the method as described in any one of claims 4 to 14, or the method as described in any one of claims 15 to 17.

37. A computer program product, characterized in that, The system includes a computer program that, when executed by a communication device for a multicast / broadcast service, causes the device to perform the method as described in any one of claims 1 to 3, or the method as described in any one of claims 4 to 14, or the method as described in any one of claims 15 to 17.

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