A communication method and related device

Abstract

This application provides a communication method and related equipment. The method includes: a terminal device determining that it is interested in or is currently receiving a first multicast service; and indicating the reception status by sending first indication information to a first network device, wherein the first indication information includes identification information of the first multicast service. Accordingly, the first network device determines the reception status of the terminal device based on the first indication information from the terminal device. By adopting this application embodiment, the number of terminal devices interested in or currently receiving multicast services can be counted in real time, and the transmission of multicast services can be maintained.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a communication method and related equipment. Background Technology

[0002] Multimedia broadcast multicast service (MBMS) originates from a data server. First, the data server sends MBMS service data to core network equipment. Then, the core network equipment sends the MBMS service data to the base station via a protocol data unit session (PDU session) or a quality of service (QoS) flow. Finally, the base station sends the MBMS service data to at least one terminal device receiving the MBMS service. Between the base station and the terminal devices, the MBMS service can be sent unicast to multiple terminal devices in a connected state via a dedicated radio bearer established with the terminal devices, or multicast to multiple terminal devices in a connected, idle, or inactive state via a common transmission channel established for the MBMS service. In actual MBMS service transmission, because many terminal devices receiving the MBMS service are in an idle or inactive state, the network side cannot know the status of these terminal devices and therefore cannot make accurate and appropriate decisions regarding the MBMS service. Summary of the Invention

[0003] This application discloses a communication method and related equipment that can count in real time the number of terminal devices receiving or interested in receiving multicast services, and maintain the transmission of multicast services.

[0004] The first aspect of this application discloses a communication method, which is applicable to a communication device, such as a terminal device, comprising:

[0005] Determine the reception status of the first multicast service;

[0006] Send a first indication message to a first network device. The first indication message is used to indicate the reception status of the terminal device for the first multicast service. The first indication message includes the identification information of the first multicast service.

[0007] In the above method, when a terminal device starts or stops receiving multicast services, it needs to report to the first network device, that is, send a first indication message to the first network device. When the terminal device moves, it also needs to report to the first network device, that is, send a first indication message to the first network device. In this way, the first network device can promptly determine the reception status of the terminal device, and count the number of terminal devices in a certain cell that are interested in receiving multicast services or are currently receiving multicast services in real time based on the reception status, avoiding incorrect statistics due to cell reselection, and thus more accurately maintaining the transmission of multicast services.

[0008] In one alternative embodiment, the receiving state includes at least one of: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

[0009] In the above method, when the terminal device is in any of the above receiving states, it needs to report to the first network device, which helps the first network device to determine the receiving state of the terminal device in a timely manner.

[0010] In another alternative, the first indication information may also include the identification information of the terminal device.

[0011] In another alternative scheme, scheduling information is received from the first network device. The scheduling information is used to indicate the time and frequency resources of the first indication information. The scheduling information is carried in system information, radio resource control (RRC) signaling, random access message, or downlink control information (DCI).

[0012] In the above method, the first network device configures the time and frequency resource location for the terminal device to send the first indication information, which is conducive to the rational use of time and frequency resources and avoids waste.

[0013] In another alternative embodiment, after sending the first indication information to the first network device, the method further includes: starting a timer; determining that the timer has timed out; and sending the first indication information to the first network device.

[0014] In the above method, the timer mechanism is used to prevent the network device from being unable to accurately count the number of terminal devices when the terminal device reports an error, as the network device is unaware of the terminal device's reception status. Therefore, this mechanism exists so that if no report is received from the terminal device after the network device's timer expires, it can be assumed that the terminal device is no longer interested in the multicast service. Furthermore, using this mechanism, when a terminal device is no longer interested in the multicast service, there is no need to report again; the network device only needs to wait for the timer to expire without reporting, and the network device will then know the reason.

[0015] In another alternative scheme, the method further includes: after performing cell reselection or changing the serving cell, sending the second indication information to the first network device, the second indication information including the first identification information and the identification information of the first multicast service, the first identification information including the identification information of the source network device and / or the identification information of the terminal device.

[0016] In the above method, when a terminal device moves, the terminal device sends a second indication information to the first network device. Accordingly, the first network device addresses the source network device according to the indication information and informs the source network device of the departure of the terminal device that is interested in receiving the multicast service. Thus, the source network device updates the number of terminal devices interested in receiving the first multicast service or the number of first multicast services in a certain area.

[0017] A second aspect of this application discloses a communication method applicable to a communication device, such as a terminal device, comprising:

[0018] After performing cell reselection or changing the serving cell, the first indication information is sent to the first network device. The first indication information includes first identification information and identification information of the first multicast service. The first identification information includes identification information of the source network device and / or identification information of the terminal device.

[0019] In the above method, when the terminal device moves, the terminal device needs to report to the first network device, that is, send the first instruction information to the first network device. In this way, the first network device can determine the reception status of the terminal device in a timely manner, and count the number of terminal devices in a certain cell that are interested in receiving multicast services or are receiving multicast services in real time, avoiding incorrect statistics due to cell reselection, and thus maintaining the transmission of multicast services more accurately.

[0020] A third aspect of this application discloses a communication method applicable to a communication device, such as a first network device, comprising:

[0021] Receive first indication information from terminal device, the first indication information being used to indicate the reception status of the terminal device for the first multicast service, the first indication information including the identification information of the first multicast service;

[0022] The receiving status of the terminal device is determined based on the first indication information.

[0023] In the above method, when a terminal device starts or stops receiving multicast services, it needs to report to the first network device, that is, send a first indication message to the first network device. When the terminal device moves, it also needs to report to the first network device, that is, send a first indication message to the first network device. In this way, the first network device can promptly determine the reception status of the terminal device, and count the number of terminal devices in a certain cell that are interested in receiving multicast services or are currently receiving multicast services in real time based on the reception status, avoiding incorrect statistics due to cell reselection, and thus more accurately maintaining the transmission of multicast services.

[0024] In one alternative embodiment, the receiving state includes at least one of: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

[0025] In the above method, when the terminal device is in any of the above receiving states, it needs to report to the first network device, which helps the first network device to determine the receiving state of the terminal device in a timely manner.

[0026] In another alternative, the first indication information may also include the identification information of the terminal device.

[0027] In another alternative approach, the method further includes: sending scheduling information to the terminal device, the scheduling information being used to indicate the time-frequency resources of the first indication information, the scheduling information being carried in system information, radio resource control (RRC) signaling, random access message, or downlink control information (DCI).

[0028] In the above method, the first network device configures the time and frequency resource location for the terminal device to send the first indication information, which is conducive to the rational use of time and frequency resources and avoids waste.

[0029] In another alternative scheme, a second network device is determined based on second indication information from the terminal device, the second indication information including the identification information of the first multicast service and a first identification information, the first identification information including the identification information of the second network device and / or the identification information of the terminal device.

[0030] In another alternative embodiment, the method further includes: sending a third indication message to the second network device, the third indication message being used to instruct the terminal device to leave, the third indication message including the identification information of the first multicast service and / or the identification information of the terminal device.

[0031] In another alternative embodiment, the method further includes: receiving a handover request message from the second network device, the handover request message including fourth indication information, the fourth indication information including the identification information of the first multicast service.

[0032] In the above method, the first network device can know the identification information of the first multicast service that the terminal device is interested in by receiving the identification information of the first multicast service in the handover request message from the second network device, thereby updating the number of terminal devices interested in receiving the first multicast service or the number of the first multicast service in a certain area.

[0033] In another alternative embodiment, the method further includes: sending a fifth indication message to the core network equipment, the fifth indication message including the identification information of the first multicast service, the identification information of the terminal equipment, and a second identification message, the second identification message including at least one of Tracking Area Identifier (TAI), Cell Global Identifier (CGI), and Public Land Mobile Network Identity (PLMN ID).

[0034] In the above method, the first network device sends a fifth indication message to the core network device. This fifth indication message is used by the core network device to address the second network device, informing the second network device of the departure of terminal devices that are interested in receiving multicast services or are currently receiving multicast services. As a result, the second network device updates the number of terminal devices interested in receiving the first multicast service or the number of first multicast services in a certain area.

[0035] In another alternative embodiment, the method further includes: receiving a first message from a terminal device, the first message including the fifth indication information.

[0036] A fourth aspect of this application discloses a communication method applicable to a communication device, such as a first core network device or an application server, comprising:

[0037] The terminal device receives a first indication message, which indicates the reception status of the terminal device for the first multicast service. The first indication message includes the identification information of the first multicast service.

[0038] The receiving status of the terminal device is determined based on the first indication information.

[0039] In the above method, when a terminal device starts or stops receiving multicast services, it needs to report to the first core network device or application server via the first network device, that is, send a first indication message to the first core network device or application server. When the terminal device moves, it also needs to report to the first core network device or application server via the first network device, that is, send a first indication message to the first core network device or application server via the first network device. In this way, the first core network device or application server can determine the reception status of the terminal device in a timely manner, and count in real time the number of terminal devices in a certain cell that are interested in receiving multicast services or are receiving multicast services, avoiding incorrect statistics due to cell reselection, thereby maintaining the transmission of multicast services more accurately.

[0040] In one alternative embodiment, the receiving state includes at least one of: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

[0041] In the above method, when the terminal device is in any of the above receiving states, it needs to report to the first core network device or application server through the first network device, which is beneficial for the first core network device or application server to count the number of terminal devices in real time.

[0042] In another alternative scheme, the first indication information further includes: the identification information of the terminal device and the second identification information, wherein the second identification information includes at least one of Tracking Area Identifier (TAI), Cell Global Identifier (CGI), and Public Land Mobile Network Identifier (PLMN ID).

[0043] In another alternative embodiment, the method further includes: receiving second indication information from the first network device, the second indication information being used to indicate the arrival of the terminal device, the second indication information including at least one of the identification information of the first multicast service, the identification information of the terminal device, the identification information of the source network device, and the identification information of the first network device.

[0044] In the above method, the first core network device or application server receives the second indication information from the first network device, and knows that the terminal device has arrived based on the indication information, thereby updating the number of terminal devices interested in receiving multicast services.

[0045] In another alternative embodiment, the method further includes: sending a request message to a second core network device, the request message being used to request context information of the terminal device; and receiving context information from the second core network device, the context information including the identification information of the first multicast service.

[0046] In the above method, the first core network device sends a request message to the second core network device, requesting the context information of the terminal device. Based on the identification information of the first multicast service in the context information, the first core network device can know the identification information of the multicast service that the terminal device is interested in, and then update the number of terminal devices interested in receiving the multicast service.

[0047] In another alternative approach, the method further includes: determining the number of terminal devices receiving the first multicast service based on the reception status of the terminal devices.

[0048] In another alternative approach, the method further includes: determining the transmission strategy of the first multicast service based on the number of terminal devices.

[0049] In the above method, the core network equipment or application server determines different transmission strategies for the first multicast service based on the number of different terminal devices, thus enabling more flexible transmission.

[0050] In another alternative embodiment, the method further includes: sending a first message to a first network device, the first message including the number of terminal devices.

[0051] A fifth aspect of this application discloses a communication method applicable to a communication device, such as a terminal device, comprising:

[0052] Determine the reception status of the first multicast service;

[0053] Send a first indication message to the first core network device. The first indication message is used to indicate the reception status of the terminal device for the first multicast service. The first indication message includes the identification information of the first multicast service.

[0054] In the above method, when a terminal device starts or stops receiving multicast services, it needs to report to the first core network device or application server via the first network device, that is, send a first indication message to the first core network device or application server. When the terminal device moves, it also needs to report to the first core network device or application server via the first network device, that is, send a first indication message to the first core network device or application server via the first network device. In this way, the receiving status of the terminal device can be determined in a timely manner via the first core network device or application server, and the number of terminal devices interested in receiving multicast services or currently receiving multicast services in a certain cell can be counted in real time, avoiding incorrect statistics due to cell reselection, thereby maintaining the transmission of multicast services more accurately.

[0055] In one alternative embodiment, the receiving state includes at least one of: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

[0056] In the above method, when the terminal device is in any of the above receiving states, it needs to report to the first core network device or application server through the first network device, which is beneficial for the first core network device or application server to count the number of terminal devices in real time.

[0057] In another alternative scheme, the first indication information further includes: the identification information of the terminal device and the second identification information, wherein the second identification information includes at least one of Tracking Area Identifier (TAI), Cell Global Identifier (CGI), and Public Land Mobile Network Identifier (PLMN ID).

[0058] In another alternative scheme, the method further includes: after performing cell reselection or changing the serving cell, sending the third indication information to the first core network device or application server, the third indication information including first identification information and identification information of the first multicast service, the first identification information including identification information of the source network device and / or identification information of the terminal device.

[0059] In the above method, when a terminal device moves, the terminal device sends a third instruction message to the first core network device or application server via the first network device. Accordingly, the first core network device or application server addresses the source network device according to the third instruction message and informs the source network device of the departure of terminal devices that are interested in receiving multicast services. Thus, the source network device can determine the number of terminal devices that are interested in receiving the first multicast service or the number of first multicast services in a certain area.

[0060] A sixth aspect of this application discloses a communication method applicable to a communication device, such as a first network device, comprising:

[0061] Identify the second network device;

[0062] Send a request message to the second network device, the request message being used to obtain the context information of the terminal device;

[0063] The context information received from the second network device includes the identification information of the first multicast service.

[0064] In the above method, the first network device determines the second network device based on the instruction information from the terminal device. The first network device updates the number of terminal devices interested in receiving the first multicast service based on the context information of the terminal device of the second network device. The existing RNAU process can be reused as much as possible to complete the statistics of the number of terminal devices interested in receiving the first multicast service. At the same time, the RNAU process is equipped with security protection to prevent idle terminal devices from making malicious reports that the first network device cannot identify.

[0065] In an alternative embodiment, the method further includes:

[0066] The Radio Access Network (RAN) notification area is configured to include one cell.

[0067] In the above method, by configuring the RAN notification area to include only one cell, when the terminal device leaves the RAN notification area, the RNAU process will be initiated, triggering the process of the first network device sending request information to the second network device and receiving the context information of the second network device, thereby updating the number of terminal devices interested in receiving the first multicast service.

[0068] In another alternative embodiment, the method further includes: receiving first indication information from a terminal device, the first indication information indicating the reception status of the terminal device for a first multicast service, the first indication information including identification information of the first multicast service.

[0069] In the above method, when a terminal device starts or stops receiving multicast services, it needs to report to the first network device, that is, send a first indication message to the first network device. When the terminal device moves, it also needs to report to the first network device, that is, send a first indication message to the first network device. In this way, the first network device can determine the reception status of the terminal device in a timely manner, and count in real time the number of terminal devices in a certain cell that are interested in receiving multicast services or are currently receiving multicast services, avoiding incorrect statistics due to cell reselection, and thus maintaining the transmission of multicast services more accurately.

[0070] In another alternative embodiment, the receiving state includes at least one of: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

[0071] In the above method, when the terminal device is in any of the above receiving states, it needs to report to the first network device, which is beneficial for the first network device to count the number of terminal devices in real time.

[0072] In another alternative, the first indication information may also include the identification information of the terminal device.

[0073] A seventh aspect of this application discloses a communication method applicable to a communication device, such as a second network device, comprising:

[0074] Receive request information from a first network device, the request information being used to obtain context information of the terminal device;

[0075] The context information, including the identifier information of the first multicast service, is sent to the first network device.

[0076] In the above method, the second network device can know that a terminal device in the cell of the second network device has left by receiving the request information from the first network device, thereby updating the number of terminal devices in the cell of the second network device that are interested in or are receiving multicast services. The first network device can determine the identification information of the multicast service that the terminal device under the first network device is interested in from the second network device to the second network device by receiving the context information of the second network device and the identification information of the first multicast service in the context information, thereby updating the number of terminal devices in the cell of the first network device.

[0077] An eighth aspect of this application discloses a communication device, which may be, for example, a terminal device or a chip in a terminal device, and the device includes:

[0078] The processing unit is used to determine the reception status of the first multicast service;

[0079] A communication unit is configured to send first indication information to a first network device. The first indication information is used to indicate the reception status of the terminal device for a first multicast service. The first indication information includes the identification information of the first multicast service.

[0080] In one alternative embodiment, the receiving state includes at least one of: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

[0081] In another alternative, the first indication information may also include the identification information of the terminal device.

[0082] In another alternative embodiment, the communication unit is further configured to receive scheduling information from the first network device, the scheduling information being used to indicate the time-frequency resources of the first indication information, and the scheduling information being carried in system information, radio resource control (RRC) signaling, random access message, or downlink control information (DCI).

[0083] In another alternative embodiment, the processing unit is further configured to start a timer; determine that the timer has timed out; and the communication unit is further configured to send the first indication information to the first network device.

[0084] In another alternative embodiment, the communication unit is further configured to send the second indication information to the first network device, the second indication information including first identification information and identification information of the first multicast service, the first identification information including identification information of the source network device and / or identification information of the terminal device.

[0085] For information on the technical effects of the eighth aspect or various alternative implementations, please refer to the description of the technical effects of the first aspect or corresponding implementations.

[0086] A ninth aspect of this application discloses a communication device, which may be, for example, a terminal device or a chip in a terminal device, and the device includes:

[0087] The processing unit is configured to send the first indication information to the first network device via the communication unit. The first indication information includes first identification information and identification information of the first multicast service. The first identification information includes identification information of the source network device and / or identification information of the terminal device.

[0088] For information on the technical effects of the ninth aspect or various alternative implementations, please refer to the description of the technical effects of the second aspect or corresponding implementations.

[0089] A tenth aspect of this application discloses a communication device, which may be, for example, a first network device or a chip in a first network device, and the device includes:

[0090] A communication unit is configured to receive first indication information from a terminal device, the first indication information being used to indicate the reception status of the terminal device for a first multicast service, the first indication information including the identification information of the first multicast service;

[0091] The processing unit is configured to determine the receiving status of the terminal device based on the first indication information.

[0092] In one alternative embodiment, the receiving state includes at least one of: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

[0093] In another alternative, the first indication information may also include the identification information of the terminal device.

[0094] In another alternative embodiment, the communication unit is further configured to send scheduling information to the terminal device. The scheduling information is used to indicate the time and frequency resources of the first indication information. The scheduling information is carried in system information, radio resource control (RRC) signaling, random access message, or downlink control information (DCI).

[0095] In another alternative embodiment, the processing unit is further configured to determine a second network device based on second indication information from the terminal device, the second indication information including identification information of the first multicast service and first identification information, the first identification information including identification information of the second network device and / or identification information of the terminal device.

[0096] In another alternative embodiment, the communication unit is further configured to send a third indication information to the second network device, the third indication information being used to instruct the terminal device to leave, the third indication information including the identification information of the first multicast service and / or the identification information of the terminal device.

[0097] In another alternative embodiment, the communication unit is further configured to receive a handover request message from the second network device, the handover request message including fourth indication information, the fourth indication information including the identification information of the first multicast service.

[0098] In another alternative embodiment, the communication unit is further configured to send a fifth indication information to the core network equipment. The fifth indication information includes the identification information of the first multicast service, the identification information of the terminal equipment, and a second identification information. The second identification information includes at least one of Tracking Area Identifier (TAI), Cell Global Identifier (CGI), and Public Land Mobile Network Identity (PLMN ID).

[0099] In another alternative embodiment, the communication unit is further configured to receive a first message from a terminal device, the first message including the fifth indication information.

[0100] For information on the technical effects of the tenth aspect or various alternative implementations, please refer to the description of the technical effects of the third aspect or corresponding implementations.

[0101] An eleventh aspect of this application discloses a communication device, which may be, for example, a first core network device or an application server, or a chip in the first core network device or a chip in the application server, and the device includes:

[0102] A communication unit is configured to receive first indication information from a terminal device, the first indication information being used to indicate the terminal device's reception status of a first multicast service, the first indication information including identification information of the first multicast service.

[0103] The processing unit is further configured to determine the receiving status of the terminal device based on the first indication information.

[0104] In one alternative embodiment, the receiving state includes at least one of: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

[0105] In another alternative scheme, the first indication information further includes: the identification information of the terminal device and the second identification information, wherein the second identification information includes at least one of Tracking Area Identifier (TAI), Cell Global Identifier (CGI), and Public Land Mobile Network Identifier (PLMN ID).

[0106] In another alternative embodiment, the communication unit is further configured to receive second indication information from the first network device, the second indication information being used to indicate the arrival of the terminal device, the second indication information including at least one of the identification information of the first multicast service, the identification information of the terminal device, the identification information of the source network device, and the identification information of the first network device.

[0107] In another alternative embodiment, the communication unit is further configured to send request information to the second core network device, the request information being used to request context information of the terminal device; and to receive context information from the second core network device, the context information including the identification information of the first multicast service.

[0108] In another alternative embodiment, the processing unit is further configured to determine the number of terminal devices receiving the first multicast service based on the reception status of the terminal devices.

[0109] In another alternative embodiment, the processing unit is further configured to determine the transmission strategy of the first multicast service based on the number of terminal devices.

[0110] In another alternative embodiment, the communication unit is further configured to send a first message to a first network device, the first message including the number of terminal devices.

[0111] For details regarding the technical effects of the eleventh aspect or various alternative implementation methods, please refer to the description of the technical effects of the fourth aspect or corresponding implementation methods.

[0112] A twelfth aspect of this application discloses a communication device, which may be, for example, a terminal device or a chip in a terminal device, and the device includes:

[0113] The processing unit is used to determine the reception status of the first multicast service;

[0114] A communication unit is configured to send first indication information to a first core network device. The first indication information is used to indicate the reception status of the terminal device for a first multicast service. The first indication information includes the identification information of the first multicast service.

[0115] In one alternative embodiment, the receiving state includes at least one of: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

[0116] In another alternative scheme, the first indication information further includes: the identification information of the terminal device and the second identification information, wherein the second identification information includes at least one of Tracking Area Identifier (TAI), Cell Global Identifier (CGI), and Public Land Mobile Network Identifier (PLMN ID).

[0117] In another alternative embodiment, the communication unit is further configured to send the third indication information to the first core network device or application server. The third indication information includes first identification information and identification information of the first multicast service. The first identification information includes identification information of the source network device and / or identification information of the terminal device.

[0118] For information on the technical effects of the twelfth aspect or various alternative implementations, please refer to the description of the technical effects of the fifth aspect or corresponding implementations.

[0119] A thirteenth aspect of this application discloses a communication device, which may be, for example, a first network device or a chip in a first network device, and the device includes:

[0120] Processing unit, used to determine the second network device;

[0121] A communication unit is used to send request information to a second network device, the request information being used to obtain context information of the terminal device;

[0122] The communication unit is further configured to receive the context information from the second network device, the context information including the identification information of the first multicast service.

[0123] In one alternative embodiment, the processing unit is further configured to configure the Radio Access Network (RAN) notification area to include a cell.

[0124] In another alternative embodiment, the communication unit is further configured to receive first indication information from a terminal device, the first indication information being used to indicate the terminal device's reception status of a first multicast service, the first indication information including identification information of the first multicast service.

[0125] In another alternative embodiment, the receiving state includes at least one of: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

[0126] For the technical effects of the thirteenth aspect or various alternative implementations, please refer to the description of the technical effects of the sixth aspect or corresponding implementations.

[0127] A fourteenth aspect of this application discloses a communication device, which may be, for example, a second network device or a chip in a second network device, and the device includes:

[0128] A processing unit is configured to receive request information from a first network device via a communication unit, wherein the request information is used to obtain context information of the terminal device.

[0129] The processing unit is configured to send the context information to the first network device through the communication unit, the context information including the identification information of the first multicast service.

[0130] For the technical effects of the fourteenth aspect or various alternative embodiments, please refer to the description of the technical effects of the seventh aspect or corresponding embodiments.

[0131] A fifteenth aspect of this application discloses a communication device, comprising at least one processor and a transceiver, wherein the at least one processor is configured to communicate with other devices via the transceiver, the memory is configured to store a computer program, and the processor invokes the computer program to perform the following operations:

[0132] Determine the reception status of the first multicast service;

[0133] Send a first indication message to a first network device. The first indication message is used to indicate the reception status of the terminal device for the first multicast service. The first indication message includes the identification information of the first multicast service.

[0134] In one alternative embodiment, the receiving state includes at least one of: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

[0135] In another alternative, the first indication information may also include the identification information of the terminal device.

[0136] In another alternative embodiment, the processor is further configured to receive scheduling information from the first network device via the transceiver. The scheduling information is used to indicate the time-frequency resources of the first indication information. The scheduling information is carried in system information, radio resource control (RRC) signaling, random access message, or downlink control information (DCI).

[0137] In another alternative embodiment, the processor is further configured to: start a timer; determine that the timer has timed out; and send the first indication information to the first network device via the transceiver.

[0138] In another alternative embodiment, the processor is further configured to send the second indication information to the first network device via the transceiver after performing cell reselection or changing the serving cell. The second indication information includes first identification information and identification information of the first multicast service. The first identification information includes identification information of the source network device and / or identification information of the terminal device.

[0139] For information on the technical effects of the fifteenth aspect or various alternative embodiments, please refer to the description of the technical effects of the first aspect or corresponding embodiments.

[0140] A sixteenth aspect of this application discloses a communication device, the communication device including at least one processor and a transceiver, wherein the at least one processor is used to communicate with other devices through the transceiver, the memory is used to store a computer program, and the processor calls the computer program to perform the following operations:

[0141] The processor is further configured to send the first indication information to the first network device via the transceiver after performing cell reselection or changing the serving cell. The first indication information includes first identification information and identification information of the first multicast service. The first identification information includes identification information of the source network device and / or identification information of the terminal device.

[0142] For information on the technical effects of the sixteenth aspect or various alternative embodiments, please refer to the description of the technical effects of the second aspect or corresponding embodiments.

[0143] A seventeenth aspect of this application discloses a communication device, the communication device including at least one processor and a transceiver, wherein the at least one processor is used to communicate with other devices through the transceiver, the memory is used to store a computer program, and the processor calls the computer program to perform the following operations:

[0144] The transceiver receives first indication information from the terminal device. The first indication information is used to indicate the reception status of the terminal device for the first multicast service. The first indication information includes the identification information of the first multicast service.

[0145] The receiving status of the terminal device is determined based on the first indication information.

[0146] In one alternative embodiment, the receiving state includes at least one of: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

[0147] In another alternative, the first indication information may also include the identification information of the terminal device.

[0148] In another alternative embodiment, the processor is further configured to send scheduling information to the terminal device via the transceiver. The scheduling information is used to indicate the time-frequency resources of the first indication information, and the scheduling information is carried in system information, radio resource control (RRC) signaling, random access message, or downlink control information (DCI).

[0149] In another alternative embodiment, the processor is further configured to determine a second network device based on second indication information from the terminal device, the second indication information including identification information of the first multicast service and first identification information, the first identification information including identification information of the second network device and / or identification information of the terminal device.

[0150] In another alternative embodiment, the processor is further configured to send third indication information to the second network device via the transceiver. The third indication information is used to instruct the terminal device to leave, and the third indication information includes the identification information of the first multicast service and / or the identification information of the terminal device.

[0151] In another alternative embodiment, the processor is further configured to receive a handover request message from the second network device via the transceiver, the handover request message including fourth indication information, the fourth indication information including the identification information of the first multicast service.

[0152] In another alternative embodiment, the processor is further configured to send fifth indication information to the core network equipment via the transceiver. The fifth indication information includes the identification information of the first multicast service, the identification information of the terminal equipment, and second identification information. The second identification information includes at least one of Tracking Area Identifier (TAI), Cell Global Identifier (CGI), and Public Land Mobile Network Identity (PLMN ID).

[0153] In another alternative embodiment, the processor is further configured to receive a first message from a terminal device via the transceiver, the first message including the fifth indication information.

[0154] For information on the technical effects of the seventeenth aspect or various alternative embodiments, please refer to the description of the technical effects of the third aspect or corresponding embodiments.

[0155] An eighteenth aspect of this application discloses a communication device, the communication device including at least one processor and a transceiver, wherein the at least one processor is used to communicate with other devices through the transceiver, the memory is used to store a computer program, and the processor calls the computer program to perform the following operations:

[0156] The transceiver receives first indication information from the terminal device. The first indication information is used to indicate the reception status of the terminal device for the first multicast service. The first indication information includes the identification information of the first multicast service.

[0157] The receiving status of the terminal device is determined based on the first indication information.

[0158] In one alternative embodiment, the receiving state includes at least one of: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

[0159] In another alternative scheme, the first indication information further includes: the identification information of the terminal device and the second identification information, wherein the second identification information includes at least one of Tracking Area Identifier (TAI), Cell Global Identifier (CGI), and Public Land Mobile Network Identifier (PLMN ID).

[0160] In another alternative embodiment, the processor is further configured to receive second indication information from the first network device via the transceiver. The second indication information is used to indicate the arrival of the terminal device. The second indication information includes at least one of the identification information of the first multicast service, the identification information of the terminal device, the identification information of the source network device, and the identification information of the first network device.

[0161] In another alternative embodiment, the processor is further configured to send request information to a second core network device via the transceiver, the request information being used to request context information of the terminal device; and to receive context information from the second core network device, the context information including the identification information of the first multicast service.

[0162] In another alternative embodiment, the processor is further configured to determine the number of terminal devices receiving the first multicast service based on the reception status of the terminal devices.

[0163] In another alternative embodiment, the processor is further configured to determine the transmission strategy of the first multicast service based on the number of terminal devices.

[0164] In another alternative embodiment, the processor is further configured to send a first message to a first network device via the transceiver, the first message including the number of the terminal devices.

[0165] For information on the technical effects of the eighteenth aspect or various alternative implementations, please refer to the description of the technical effects of the fourth aspect or corresponding implementations.

[0166] A nineteenth aspect of this application discloses a communication device, the communication device including at least one processor and a transceiver, wherein the at least one processor is used to communicate with other devices through the transceiver, the memory is used to store a computer program, and the processor calls the computer program to perform the following operations:

[0167] Determine the reception status of the first multicast service;

[0168] The transceiver sends a first indication message to the first core network device. The first indication message is used to indicate the reception status of the terminal device for the first multicast service. The first indication message includes the identification information of the first multicast service.

[0169] In one alternative embodiment, the receiving state includes at least one of: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

[0170] In another alternative scheme, the first indication information further includes: the identification information of the terminal device and the second identification information, wherein the second identification information includes at least one of Tracking Area Identifier (TAI), Cell Global Identifier (CGI), and Public Land Mobile Network Identifier (PLMN ID).

[0171] In another alternative embodiment, the processor is further configured to send the third indication information to the first core network device or application server via a transceiver after performing cell reselection or changing the serving cell. The third indication information includes first identification information and identification information of the first multicast service. The first identification information includes identification information of the source network device and / or identification information of the terminal device.

[0172] For information on the technical effects of the nineteenth aspect or various alternative embodiments, please refer to the description of the technical effects of the fifth aspect or corresponding embodiments.

[0173] A twentieth aspect of this application discloses a communication device, comprising at least one processor and a transceiver, wherein the at least one processor is configured to communicate with other devices via the transceiver, the memory is configured to store a computer program, and the processor invokes the computer program to perform the following operations:

[0174] Identify the second network device;

[0175] The transceiver sends a request message to the second network device, the request message being used to obtain the context information of the terminal device.

[0176] The transceiver receives the context information from the second network device, the context information including the identification information of the first multicast service.

[0177] In one alternative embodiment, the processor is further configured to configure the Radio Access Network (RAN) notification area to include a cell.

[0178] In another alternative embodiment, the processor is further configured to receive first indication information from the terminal device via the transceiver, the first indication information indicating the reception status of the terminal device for the first multicast service, the first indication information including the identification information of the first multicast service.

[0179] In another alternative embodiment, the receiving state includes at least one of: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

[0180] In another alternative, the first indication information may also include the identification information of the terminal device.

[0181] For the technical effects of the twentieth aspect or various alternative implementations, please refer to the description of the technical effects of the sixth aspect or corresponding implementations.

[0182] A twenty-first aspect of this application discloses a communication device, comprising at least one processor and a transceiver, wherein the at least one processor is configured to communicate with other devices via the transceiver, the memory is configured to store a computer program, and the processor invokes the computer program to perform the following operations:

[0183] The transceiver receives request information from the first network device, and the request information is used to obtain the context information of the terminal device.

[0184] The transceiver sends the context information to the first network device, the context information including the identification information of the first multicast service.

[0185] For information on the technical effects of aspect 21 or various alternative implementations, please refer to the description of the technical effects of aspect 7 or corresponding implementations.

[0186] The twenty-second aspect of this application discloses a chip, which includes at least one processor and an interface circuit. Optionally, the chip also includes a memory. The memory, the interface circuit, and the at least one processor are interconnected by a circuit. The at least one memory stores a computer program. When the computer program is executed by the processor, it implements the method described in any aspect or any optional scheme.

[0187] The twenty-third aspect of this application discloses a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in any aspect or any optional scheme of any aspect.

[0188] The twenty-fourth aspect of this application discloses a communication system, which includes the apparatus described in the eighth aspect, the ninth aspect, or the tenth aspect, as well as the apparatus described in the eleventh and twelfth aspects, and the apparatus described in the thirteenth and fourteenth aspects.

[0189] The twenty-fifth aspect of this application discloses a computer product that, when the computer program product is run on a processor, implements the method described in any aspect or any optional scheme of any aspect. Attached Figure Description

[0190] The accompanying drawings used in the embodiments of this application are described below.

[0191] Figure 1 This is a schematic diagram of the structure of a communication system provided in an embodiment of this application;

[0192] Figure 2 This is a schematic diagram of the transmission of an MBMS service provided in an embodiment of this application;

[0193] Figure 3 This application provides a 4G counting mechanism.

[0194] Figure 4 This is a schematic flowchart of a communication method provided in an embodiment of this application;

[0195] Figure 5 This is a schematic diagram of another communication method provided in the embodiments of this application;

[0196] Figure 6 This is a schematic diagram of another communication method provided in the embodiments of this application;

[0197] Figure 7 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0198] Figure 8 This is a schematic diagram of the structure of another communication device provided in the embodiments of this application;

[0199] Figure 9 This is a schematic diagram of the structure of another communication device provided in the embodiments of this application;

[0200] Figure 10 This is a schematic diagram of the structure of another communication device provided in the embodiments of this application. Detailed Implementation

[0201] The embodiments of this application are described below with reference to the accompanying drawings.

[0202] Please see Figure 1 , Figure 1This is a schematic diagram of the structure of a communication system 100 provided in an embodiment of the present invention. The communication system 100 may include an application server 110, a core network device 111, a network device 112, a network device 113, and terminal devices 101, 102, 103, 104, 105, and 106. It should be understood that the communication system 100 to which the methods of the embodiments of this application can be applied may include more or fewer application servers, core network devices, network devices, or terminal devices. Network devices and terminal devices may be hardware, software functionally defined, or a combination of both. Network devices and terminal devices can communicate with each other through other devices or network elements. In this communication system, network device 112 can transmit data with multiple terminal devices; that is, network device 112 sends downlink data to terminal devices 101-106, and terminal devices 101-106 can also send uplink data to network device 112. Furthermore, terminal devices 104, 105, and 106 can also form a communication system. In this system, network device 112 can send downlink data to terminal devices 101, 102, and 105, and then terminal device 105 can send the downlink data to terminal device 104 or terminal device 106. Application server 110 or core network device 111 transmits data with terminal devices 101-106 through network device 112. The method in this embodiment can be applied to... Figure 1 In the communication system 100 shown.

[0203] 1) Terminal equipment, including equipment that provides voice and / or data connectivity to users, specifically including equipment that provides voice to users, or equipment that provides data connectivity to users, or equipment that provides both voice and data connectivity to users. For example, it may include a handheld device with wireless connectivity or a processing device connected to a wireless modem. This terminal equipment can communicate with the core network via a radio access network (RAN), exchanging voice or data with the RAN, or interacting with the RAN for both voice and data. The terminal equipment may include user equipment (UE), wireless terminal equipment, mobile terminal equipment, device-to-device (D2D) terminal equipment, vehicle-to-everything (V2X) terminal equipment, machine-to-machine / machine-type communications (M2M / MTC) terminal equipment, Internet of Things (IoT) terminal equipment, light UE, reduced capability UE (REDCAP UE), subscriber unit, subscriber station, mobile station, remote station, access point (AP), remote terminal, access terminal, user terminal, user agent, or user device, etc. For example, it may include mobile phones (or "cellular" phones), computers with mobile terminal devices, portable, pocket-sized, handheld, or computer-embedded mobile devices, etc. Examples include personal communication service (PCS) phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), and other similar devices. It also includes limited devices, such as those with low power consumption, limited storage capacity, or limited computing power.Examples include information sensing devices such as barcodes, radio frequency identification (RFID), sensors, global positioning system (GPS), and laser scanners.

[0204] By way of example and not limitation, in this embodiment, the terminal device can also be a wearable device. Wearable devices, also known as wearable smart devices or smart wearable devices, are 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, but also achieve powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include those that are feature-rich, large in size, and can achieve complete or partial functions without relying on a smartphone, such as smartwatches or smart glasses, as well as those that focus on a specific type of application function and require the use of other devices such as smartphones, such as various smart bracelets, smart helmets, and smart jewelry for vital sign monitoring.

[0205] The various terminal devices described above, if located in a vehicle (e.g., placed inside or installed inside a vehicle), can be considered as vehicle-mounted terminal devices, also known as on-board units (OBUs).

[0206] In this embodiment, the terminal device may further include a relay. Alternatively, it can be understood that anything capable of data communication with a base station can be considered a terminal device.

[0207] In this application embodiment, the device for implementing the functions of the terminal device can be the terminal device itself, or it can be a device capable of supporting the terminal device in implementing the functions, such as a chip system, which can be installed in the terminal device. In this application embodiment, the chip system can be composed of chips, or it can include chips and other discrete devices. In the technical solutions provided in this application embodiment, the terminal device is used as an example to describe the technical solutions provided in this application embodiment.

[0208] 2) Network devices, including access network (AN) devices such as base stations (e.g., access points), can refer to devices in the access network that communicate with wireless terminal devices over the air interface via one or more cells, or, for example, network devices in a vehicle-to-everything (V2X) technology such as roadside units (RSUs). Base stations can be used to convert received air frames to and from IP packets, acting as routers between terminal devices and the rest of the access network, which may include IP networks. RSUs can be fixed infrastructure entities supporting V2X applications and can exchange messages with other entities supporting V2X applications. Network devices can also coordinate the management of air interface attributes. For example, network equipment may include evolved base stations (NodeB, eNB, or e-NodeB) in long term evolution (LTE) systems or long term evolution-advanced (LTE-A) systems, or may include next-generation node B (gNB) in 5th generation (5G) NR systems (also referred to as NR systems), or may include centralized units (CU) and distributed units (DU) in cloud radio access network (Cloud RAN) systems. The embodiments of this application are not limited.

[0209] In this application embodiment, the device for implementing the function of the network device can be the network device itself, or it can be a device capable of supporting the network device in implementing that function, such as a chip system, which can be installed in the network device. In the technical solutions provided in this application embodiment, the example of a network device being used to implement the function of the network device is used to describe the technical solutions provided in this application embodiment.

[0210] 3) Core network equipment, such as access and mobility management functions (AMF), session management functions (SMF), or user plane functions (UPF), etc., or for example, core network equipment may include mobility management entity (MME), serving gateway (SGW), packet data node gateway (PGW), home subscriber server (HSS) storing user subscription information, policy and charging rule function (PCRF), etc., or for example, the core network equipment may include mobile switching center (MSC) / visitor location register (VLR), gateway mobileswitching center (GMSC), serving general packet radio service support node (SGSN), gateway general packet radio service support node (GGSN), home location register (...). The core network equipment (register, HLR, etc.) can also be the core network equipment in future communication systems, but this application embodiment is not limited to this.

[0211] In this application embodiment, the device for implementing the function of the core network device can be the core network device itself, or it can be a device capable of supporting the core network device in implementing the function, such as a chip system. This device can be installed in the core network device. In the technical solutions provided in this application embodiment, the core network device is used as an example to describe the technical solutions provided in this application embodiment.

[0212] 4) Application server, for example, can be an application server that allows multiple users to use the application at the same time. The application server can be a single server or a server cluster consisting of multiple servers, or other hardware devices with computing capabilities.

[0213] 5) Radio Resource Control (RRC) states: Terminal devices have three RRC states: RRC connected state, RRC idle state, and inactive state.

[0214] RRC connection state (or, can also be simply called connection state. In this article, "connection state" and "RRC connection state" are the same concept and the two terms can be used interchangeably): The terminal device establishes an RRC connection with the network, and at the same time, the network establishes a connection with the core network for that terminal device, enabling data transmission.

[0215] RRC idle state (or simply idle state; in this article, "idle state" and "RRC idle state" are the same concept and the two terms can be used interchangeably): The terminal device has not established an RRC connection with the network, the base station has not stored the context of the terminal device, and the network and core network have not established a connection for the terminal device. If the terminal device needs to enter the RRC connected state from the RRC idle state, it needs to initiate an RRC connection establishment process.

[0216] RRC inactive state (or, can also be simply called inactive state. In this article, "deactivated state," "inactive state," "RRC inactive state," and "RRC deactivated state" are the same concept and these terms are interchangeable): The terminal device previously entered the RRC connected state, and then the base station released the RRC connection, but the base station preserved the context of the terminal device, and the connection established between the network and the core network for the terminal device was not released. If the terminal device needs to re-enter the RRC connected state from the RRC inactive state, it needs to initiate an RRC connection recovery process (or RRC connection re-establishment process).

[0217] 6) Multimedia broadcast multicast service (MBMS) is a service intended for multiple terminal devices, such as live streaming, public safety, and batch software updates. MBMS transmission needs to consider the reception by multiple terminal devices. It can employ multicast (multi-channel) transmission technology, which sends MBMS services to multiple terminal devices simultaneously through a common transmission path; or unicast transmission technology, which sends MBMS services to each terminal device through separate transmission channels established with each terminal device. Multicast transmission technologies in 4G include single cell point-to-multipoint (SC-PTM) and multicast-broadcast single-frequency network (MBSFN) technologies.

[0218] The above describes some concepts involved in the embodiments of this application. The technical features of the embodiments of this application are described below.

[0219] MBMS services originate from data servers, such as Figure 2 The diagram illustrates the transmission of MBMS services. First, the data server sends MBMS service data to the core network equipment. Then, the core network equipment sends the MBMS service data to the base station via a Protocol Data Unit Session (PDU session) or a Quality of Service (QoS) flow. Finally, the base station sends the MBMS service data to at least one terminal device receiving the MBMS service. Between the base station and the terminal devices, the MBMS service can be sent unicast to multiple UEs in a connected state via a dedicated radio bearer established with the UE, or multicast to multiple terminal devices in a connected, idle, or inactive state via a common transmission channel (multicast radio bearer) established for the MBMS service. During the actual transmission of MBMS services, the base station or core network needs to determine the transmission method to send the MBMS service to specific terminal devices and how to maintain the MBMS service transmission based on the number of terminal devices currently receiving or interested in the MBMS service.

[0220] Both 3G and 4G multicast transmission technologies incorporate counting mechanisms to count the number of terminal devices within a defined area that are receiving or interested in a specific MBMS service. Figure 3 As shown, Figure 3 This refers to the 4G counting mechanism. In 3G and 4G, the base station can send a counting request to the terminal device through a multicast control channel (MCCH) specifically designed for multicast transmission. The counting request carries the identification information of the MBMS service. After receiving the counting request, if the terminal device is currently receiving the MBMS service or is interested in receiving the MBMS service, it sends a counting response to the base station according to pre-set rules. The base station counts the number of terminal devices currently receiving the MBMS service or interested in receiving the MBMS service based on the counting responses sent by the terminal devices, thereby maintaining the transmission of the MBMS service.

[0221] In 3G and 4G counting mechanisms, the counting request information relies on the MCCH channel, which is specifically designed for MBMS services. However, in the MBMS service transmission mechanism of the 5th generation mobile communication technology (5G), the MCCH channel is abandoned for the sake of transmission flexibility. Therefore, the existing counting mechanism cannot be used in 5G. Thus, how the base station or core network can count the number of terminal devices that are receiving MBMS services or are interested in receiving MBMS services, so as to maintain the transmission of MBMS services, is a technical problem that needs to be solved by those skilled in the art.

[0222] Please see Figure 4 , Figure 4 This application provides a communication method, which includes, but is not limited to, the following steps:

[0223] Step S401: The terminal device determines the reception status of the first service.

[0224] Specifically, step S401 is an optional step. The first service can be a multicast service, a unicast service, or other services; this solution does not limit this.

[0225] Specifically, the receiving status is used to indicate the receiving status, subscription status, or interest status of the terminal device regarding the first service, including at least one of: starting to receive the first service, currently receiving the first service, stopping receiving the first service, about to receive the first service, hoping to receive the first service, interested in receiving the first service, and not interested in receiving the first service. The receiving status can also be referred to as "interested" or "not interested." Correspondingly, the terminal device determining that it is interested in the first service means that it has started receiving the first service, is currently receiving the first service, is about to receive the first service, or hopes to receive the first service. The terminal device determining that it is not interested in the first service means that it has stopped receiving or is not interested in receiving the first service. It should be noted that in the following steps, the terminal device needs to send the receiving status to the network device so that the network device can determine whether the terminal device needs to receive the first service. Furthermore, the network device can count the number of terminal devices interested in the first service. That is, the receiving status is used to indicate whether the terminal device expects to receive the first service or does not expect to receive the first service. This application embodiment does not limit the specific definition and sending form of the receiving status; the first service will be specifically described below using the first multicast service as an example.

[0226] Step S402: The terminal device sends a first instruction message to the first network device.

[0227] Specifically, the first indication information is used to indicate the reception status of the terminal device for the first multicast service. The first indication information includes the identification information of the first multicast service, such as a temporary mobile group identity (TMGI) or other identification information used to identify the first multicast service. The first indication information also includes the identification information of the terminal device, such as an international mobile subscriber identification number (IMSI), a temporary mobile subscriber identity (TMSI), an SAE-temporary mobile subscriber identity (S-TMSI), a globally unique temporary UE identity (GUTI), or a cell-radio network temporary identifier (C-RNTI), etc. In several embodiments of this application, for the sake of brevity, starting to receive the first multicast service, receiving the first multicast service, about to receive the first multicast service, hoping (expecting) to receive the first multicast service, or being interested in receiving the first multicast service are simply referred to as subscribing to the first multicast service, and stopping receiving the first multicast service or not being interested in receiving the first multicast service are simply referred to as not subscribing to the first multicast service.

[0228] Specifically, when the terminal device is in an idle or inactive state, the first indication information can be carried in a message during the random access procedure. The random access message is Msg1, Msg3, Msg5, or MsgA, and the random access can be a four-step random access or a two-step random access procedure. When the terminal device is in a connected state, the first indication information is carried in a media access control element (MAC CE), a control protocol data unit (Control PDU), or an RRC message.

[0229] Optionally, before step S402, this embodiment further includes step S4021: the terminal device determines to send first indication information to the first network device. Specifically, the terminal device determining to send the first indication information to the first network device includes the following two implementation methods:

[0230] In the first possible implementation, the terminal device determines whether it needs to report the first indication information based on its reception status of the first service. Specifically, when the terminal device determines that the reception status has changed, it determines that it needs to initiate a reporting process. Furthermore, the terminal device sends the first indication information to the first network device. Thus, the terminal device can promptly report its reception status of the first service, and the network device can accurately count the number of terminal devices subscribing to the first multicast service within a specific area.

[0231] In the second possible implementation, the terminal device determines to report the first indication information based on the change of the serving cell. Specifically, when the idle or inactive terminal device changes the serving cell or serving area (such as the multicast service area, which may include at least one cell) or a cell reselection occurs, the terminal device can trigger the reporting process and send the first indication information to the first network device.

[0232] For example, after a terminal device initiates a reception status reporting process, if the terminal device determines that it has subscribed to a first multicast service, it sends a first indication message to the first network device. This first indication message includes at least one of the following: identification information of the first multicast service, an interest indication, and the terminal device's identification information. The interest indication is used to instruct the terminal device to subscribe to the first multicast service. Here, both the interest indication and the terminal device's identification information can be reported, or only one can be reported. If the terminal device's identification information is reported but the interest indication is not, the first network device can determine the terminal device's reception status based on the terminal device's identification information. For example, assuming the first network device previously knew that the terminal device had subscribed to the first multicast service, when the first network device receives the report again, it can determine that the terminal device reported it because of a change in its reception status, and thus determine that the terminal device is not currently subscribed to the first multicast service. If the interest indication is reported but the terminal device's identification information is not, the first network device can determine that the number of terminal devices subscribing to the first multicast service has changed based on the interest indication, and then update the number of terminal devices within the first network device's cell or service area that are interested in subscribing to the first multicast service.

[0233] Accordingly, after the terminal device initiates the reception status reporting process, if the terminal device determines that it will not subscribe to the first multicast service, it sends a first indication message to the first network device. This first indication message includes at least one of the following: the identifier of the first multicast service, a "not interested" indication, and the identifier of the terminal device. The "not interested" indication indicates that the terminal device will not subscribe to the first multicast service. Both the "not interested" indication and the terminal device's identifier can be reported, or only one can be reported. If the terminal device's identifier is reported but the "not interested" indication is not, the first network device can determine the terminal device's reception status based on the identifier. For example, if the first network device previously knew that the terminal device was subscribed to the first multicast service, then upon receiving the report again, the first network device can determine that the terminal device reported the change due to a change in its reception status, and thus determine that the terminal device is no longer subscribing to the first multicast service. If the "not interested" indication is reported but the terminal device's identifier is not, the first network device can determine that the number of terminal devices subscribing to the first multicast service has changed based on the "not interested" indication, and then update the number of terminal devices subscribing to the first multicast service within the first network device's cell or service area.

[0234] Through the communication method provided in the embodiments of this application, the network device can determine the receiving status of the terminal device in a timely manner, avoid incorrect statistics due to cell reselection, and thus maintain the transmission of the first multicast service more accurately.

[0235] Optionally, before step S402, a step S4022 is included: the network device instructs the terminal device whether to report the subscription status. Accordingly, the terminal device determines whether to report the subscription status based on the instruction information from the network device. In other words, the receiving status reporting function provided in this application can be controlled by the network device, thereby improving the flexibility of network device control.

[0236] In one optional scheme, the terminal device determines whether it needs to report the first indication information based on the indication information from the network device. Specifically, the network device can send indication information to the terminal device, which indicates whether the terminal device needs to report its reception status. Accordingly, the terminal device receives the indication information and determines whether it needs to report the first indication information based on it. Only when the terminal device determines that it needs to report the first indication information will it further determine whether its reception status for the first service has changed and / or whether its serving cell has changed. If a change has occurred, the first indication information is reported according to the two implementation methods described above. When the terminal device determines that it does not need to report the first indication information, it does not need to further determine whether its reception status for the first service has changed or whether its serving cell has changed, and therefore will not report the first indication information.

[0237] For example, the indication information from the network device includes a start reporting indication (or enable indication) and / or a stop reporting indication (or disable indication). The start reporting indication is used to instruct the terminal device to report the reception status of the first multicast service, and the stop reporting indication is used to instruct the terminal device not to report the reception status of the first multicast service. The start reporting indication and the stop reporting indication can be two separate information cells. Alternatively, the indication information can be indicated by a single information cell. A first value indicates that the terminal device needs to report the reception status of the first multicast service, and a second value indicates that the terminal device does not need to report the reception status of the first multicast service. Through the communication method provided by this implementation, the network device can flexibly control the reporting of the multicast service reception status by the terminal devices. For example, when the network device has determined that the number of terminal devices subscribed to the first multicast service is sufficient, or when the network device determines that it no longer needs to collect statistics on the reception status of the terminal devices, it can send indication information to the terminal devices, instructing them not to report the reception status, thus avoiding excessive signaling transmission and wasting resources in the communication system.

[0238] In one possible design, the indication information can be provided without distinguishing between service type or service identifier. That is, the network device can use a single indication to instruct the terminal device to report all services, thereby controlling the reporting of reception status more efficiently and saving resource overhead. In another possible design, the indication information can be provided distinguishing between service type or service identifier. Specifically, the indication information may include a service type identifier or a service identifier, used to instruct the terminal device whether to report the reception status for the corresponding service. For example, the network device sends indication information to the terminal device, the indication information including a service identifier corresponding to a second multicast service, to instruct the terminal device to stop reporting the reception status for the second multicast service. After receiving the indication information, the terminal device stops reporting the reception status for the second multicast service accordingly. As another example, the network device sends indication information to the terminal device, the indication information including service type information. After receiving the indication information, the terminal device determines whether it needs to report the service corresponding to the service type information based on the service type information. Furthermore, the indication information includes terminal device type information. After receiving the indication information, the terminal device determines whether the corresponding type of terminal device needs to report based on the terminal device type information. In other words, the network device can indicate which terminal devices need to report the first indication information, and / or which types of services or specific services the terminal devices need to report the reception status for, by including at least one of the following in the indication information: service type identifier, service identifier, terminal device type identifier, and terminal identifier. This allows for more flexible control over the reporting of reception status and saves communication resources.

[0239] In one alternative approach, the terminal device receives scheduling information from the first network device. This scheduling information is used to indicate the time-frequency resources of the first indication information. The scheduling information is carried in system information, Radio Resource Control (RRC) signaling, random access message, downlink control information (DCI), or random access response (RAR).

[0240] Specifically, the first network device instructs the terminal device to report the resources for the first indication information via scheduling information, such as dynamic grants, grant-free resources, semi-persistent scheduling, or configured grants. This scheduling information may include time-domain location indication, frequency-domain location indication, period, modulation information, etc. The time-domain location indicates the time-domain location of the first indication information, the frequency-domain location indicates the frequency-domain resource location of the first indication information, the period indicates the period during which the frequency-domain resource can be used, and the modulation information includes a modulation and coding scheme (MCS). Accordingly, the terminal device can obtain the time-domain location, frequency-domain location, or resource period corresponding to the resource for transmitting the first indication information based on the scheduling information, and then transmit the first indication information to the first network device at the corresponding time-domain location or frequency-domain location during the transmission period.

[0241] The communication method provided in this application embodiment, in which the first network device allocates time and frequency resources for the terminal device to report the first indication information, can make reasonable use of time and frequency resources.

[0242] In one alternative approach, after the terminal device sends the first indication information to the first network device, the method further includes: the terminal device determining that the timer has timed out, and sending the first indication information to the first network device.

[0243] Specifically, the timer has a fixed duration, which can be predefined by a standard, configured by the first network device, or preset by the terminal device. If the terminal device initiates a reporting process and sends a first indication message to the first network device, it starts the first timer. The duration of the first timer is either predefined by a standard or preset by the terminal device. In one possible example, if the terminal device still subscribes to the first multicast service when the first timer expires, it sends the first indication message to the first network device again and restarts the first timer. In another possible instance, if the terminal device is not interested in receiving the first multicast service when the first timer expires, it sends the first indication message to the first network device again, instructing it not to subscribe to the first multicast service, and restarts the timer. In yet another possible instance, if the terminal device does not subscribe to the first multicast service when the first timer expires, it does not send the first indication message and stops the timer.

[0244] Correspondingly, after the terminal device sends the first indication information to the first network device for the first time, the first network device can also start a second timer. The duration of the second timer is either predefined by the standard or configured by the network device. If the second timer expires and the first network device does not receive the first indication information from the terminal device again, the first network device can assume that the terminal device is not subscribing to the first multicast service. When the terminal device is not subscribing to the first multicast service, it does not need to send the first indication information to the first network device again; it only needs to wait for the second timer of the first network device to expire. Alternatively, it can send the first indication information to the first network device without waiting for the second timer to expire. Here, the duration of the first timer and the second timer, as well as at least one of the following processes—starting, restarting, and processing after timeout—can be consistent. In one implementation, the two timers can be defined as the same timer, with the first timer maintained in the terminal device and the second timer maintained in the network device.

[0245] The communication method provided in this application effectively prevents network devices from being unaware of the receiving status of terminal devices when terminal devices report errors, thus hindering accurate counting of terminal devices. Therefore, with this mechanism, if no report is received from a terminal device after the network device's timer expires, it can be assumed that the terminal device is no longer interested in the multicast service. Furthermore, using this mechanism, when a terminal device is no longer interested in the multicast service, there is no need to report again; the network device only needs to wait for the timer to expire without reporting, thereby saving resources.

[0246] In one alternative approach, when the terminal device changes its reception status for the first multicast service, the terminal device sends the first indication information to the first network device.

[0247] Specifically, the change in reception status could be a change from subscribing to the first multicast service to not subscribing to the first multicast service, and so on.

[0248] For example, when a terminal device determines that its reception status for the first multicast service has changed from subscribing to not subscribing to the first multicast service, the terminal device sends a first indication message to the first network device. Accordingly, the first network device determines, based on the first indication message, that the number of terminal devices in its cell that are subscribing to the first multicast service decreases by one.

[0249] Accordingly, when a terminal device determines that it has changed from not subscribing to the first multicast service to subscribing to the first multicast service, the terminal device sends a first instruction information to the first network device. Accordingly, the first network device determines, based on the first instruction information, that the number of terminal devices subscribing to the first multicast service in the cell of the first network device increases by one.

[0250] In one alternative approach, when the RRC state of the terminal device changes, the terminal device sends the first indication information to the first network device.

[0251] Specifically, before the RRC status of the terminal device changes, the terminal device sends the first indication information to the first network device, and / or after the RRC status of the terminal device changes, the terminal device sends the first indication information to the first network device.

[0252] For example, if the RRC state of a terminal device changes from connected to idle, the terminal device reports the first indication information when it was in connected state before the change and / or reports the first indication information when it is in idle state after the change.

[0253] For example, if the RRC state of a terminal device changes from an inactive state to a connected state, the terminal device will report the first indication information when it was in an inactive state before the change, and / or the terminal device will report the first indication information when it is in a connected state after the change.

[0254] In one alternative approach, after the terminal device undergoes an RRC reconstruction, RRC reconfiguration, or RRC recovery process, the terminal device sends the first indication information to the first network device.

[0255] Specifically, when a terminal device in a connected state experiences a handover failure, wireless link failure, integrity protection failure, or RRC reconfiguration failure, an RRC connection reconstruction process will be triggered. The terminal device can then send a first indication message to the first network device during or after the reconstruction process. When the first network device reconfigures parameters for a connected terminal device, it sends an RRC reconfiguration command. After reconfiguration, the terminal device can send a first indication message to the first network device. When a terminal device transitions from an inactive state to a connected state, an RRC recovery process will be triggered. The terminal device can then send a first indication message to the first network device during or after the RRC recovery process.

[0256] In one alternative scheme, after a terminal device undergoes an RRC reconstruction or recovery process, if the serving cell after reconstruction or recovery is different from the serving cell before reconstruction, the network device corresponding to the serving cell after reconstruction or recovery will send a request message to the network device corresponding to the serving cell before reconstruction or recovery to obtain the context of the terminal device. In this way, the network device corresponding to the serving cell before reconstruction or recovery can know that the terminal device has left, and thus update the number of terminal devices subscribing to the first multicast service in the corresponding cell or the corresponding service area. When sending the context of the terminal device before reconstruction or recovery, the network device corresponding to the serving cell before reconstruction or recovery can carry the identification information of the terminal device subscribing to the first multicast service. In this way, the network device corresponding to the serving cell after reconstruction or recovery can also know the first multicast service subscribed to by the terminal device, and thus update the number of terminal devices subscribing to the first multicast service.

[0257] In one alternative scheme, after performing cell reselection, changing the serving cell, or changing the serving area (such as a multicast service area, which may include at least one cell), the terminal device sends the second indication information to the first network device. Accordingly, the first network device determines the second network device based on the second indication information from the terminal device.

[0258] Specifically, the second indication information includes the first identification information and the identification information of the first multicast service. The first identification information includes the identification information of the source network device and / or the identification information of the terminal device.

[0259] Specifically, after receiving the second instruction information from the terminal device, the first network device addresses the second network device based on the identification information of the source network device or the identification information of the terminal device (e.g., the identification information of an inactive terminal device).

[0260] For example, if a terminal device is in an idle state, the network device is unaware of the terminal device's movement after cell reselection or changing the serving cell. Only when the terminal device moves out of the tracking area (TA) will it initiate a tracking area update (TAU) process to inform the core network device that the terminal device has changed its TA. However, since the TA is generally quite large, including many cells, the terminal device may not initiate a TAU process when performing cell reselection or changing the serving cell, causing the network device to be unable to update the number of terminal devices subscribing to the first multicast service in a timely manner.

[0261] If the terminal device is inactive, the network device is unaware of the terminal device's movement after cell reselection or changing the serving cell. Only when the terminal device moves out of the RAN-Based Notification Area (RNA) will it initiate a RAN-Based Notification Area Update (RNAU) process to inform the network device that the terminal device has changed the RNA. However, since the RNA is generally quite large, including many cells, the terminal device may not initiate the RNAU process when performing cell reselection or changing the serving cell, causing the network device to be unable to update the number of terminal devices subscribing to the first multicast service in a timely manner.

[0262] Therefore, if the terminal device is in an idle or inactive state, changing its serving cell or serving area will trigger a process of sending a second indication message to the first network device. For example, the terminal device's serving cell is reselected from another cell to a cell of the first network device, triggering the process of sending a second indication message to the first network device. The other cell could be a cell of the first network device or a cell of another network device.

[0263] In one alternative approach, after the first network device identifies the second network device, the first network device sends a third instruction message to the second network device.

[0264] Specifically, the third indication information is used to instruct the terminal device to leave the cell of the second network device. The third indication information includes the identification information of the first multicast service. Optionally, the third indication information may also include the identification information of the terminal device and / or the departure indication information. If the third indication information only includes the identification information of the first multicast service, the second network device can only determine that one of the terminal devices subscribing to the first multicast service is missing based on the third indication information, but cannot determine which specific terminal device it is. If the third indication information includes the identification information of the first multicast service and the identification information of the terminal device, the second network device can determine which specific terminal device subscribing to the first multicast service has left the cell or service area of ​​the second network device based on the third indication information.

[0265] Specifically, after the first network device determines the second network device, the first network device sends a third indication message to the second network device through the Xn interface (or other interface, such as the X2 interface) between the first network device and the second network device. After receiving the third indication message, the second network device can know that the terminal device subscribing to the first multicast service has left the cell of the second network device, thereby updating the number of terminal devices subscribing to the first multicast service.

[0266] The method provided in this application embodiment allows the first network device to send a third indication message to the second network device. Based on the third indication message, the second network device can determine the departure of terminal devices in its cell, thereby updating the number of terminal devices in a timely manner and avoiding inaccurate transmission strategies due to untimely updates.

[0267] In one alternative approach, a first network device receives a first message from a terminal device. The first message is used to indicate the configuration information of a second network device. Specifically, the first message includes fifth indication information. The first network device sends the fifth indication information to the core network device. The fifth indication information is used to indicate the configuration information of the second network device. The fifth indication information includes all the information required by the core network device to determine the second network device.

[0268] Specifically, if the terminal device is in an idle or inactive state, the first message can be carried in a random access message, which may be Msg1, Msg3, Msg5, or MsgA. If the terminal device is in a connected state, the first message is carried in a media access control element (MAC CE), control protocol data unit (Control PDU), or RRC message. The fifth indication information includes the identification information of the first multicast service, the first identification information, and the second identification information. The first identification information includes the identification information of the source network device and / or the identification information of the terminal device. The second identification information includes at least one of the following: tracking area identity (TAI), cell global identifier (CGI), and public land mobile network identity (PLMN ID). The identification information is not limited to those listed here, and the names of the identifiers are not limited; they are merely examples.

[0269] In one possible instance, after the first network device identifies the second network device, if the first network device discovers that there is no directly usable interface between the first and second network devices, or for other reasons, the core network device needs to forward the message. Since the second indication information sent by the terminal device may not be sufficient for the core network device to address the second network device, the first network device can send a first request message to the terminal device to request more information so that the core network device can address the second network device. After receiving the first request message, the terminal device sends a first message to the first network device, which includes fifth indication information. This fifth indication information includes all the information required by the core network device to identify the second network device. The first network device sends the fifth indication information to the core network device. After receiving the fifth indication information, the core network device addresses the second network device according to the fifth indication information and sends a notification message to the second network device, notifying the second network device that a certain terminal device subscribing to the first multicast service has left the cell of the second network device. After receiving the notification message, the second network device updates the number of terminal devices subscribing to the first multicast service in the cell of the second network device according to the notification message.

[0270] In one alternative approach, the first network device receives a second message from the terminal device, the second message including a sixth indication message, and the first network device sends the sixth indication message and / or the second indication message to the core network device.

[0271] Specifically, the second message is used to indicate the configuration information of the second network device, the sixth indication information is used to indicate the configuration information of the second network device, the sixth indication information includes some information required by the core network device to determine the second network device, and the second indication information includes another part of the information required by the core network device to determine the second network device.

[0272] Specifically, if the terminal device is in an idle or inactive state, the second message can be carried in a random access message, which may be Msg1, Msg3, Msg5, or MsgA. If the terminal device is in a connected state, the second message is carried in a media access control element (MAC CE), control protocol data unit (Control PDU), or RRC message. The second indication information includes first identification information and identification information of the first multicast service. The first identification information includes the identification information of the source network device and / or the identification information of the terminal device. The sixth indication information includes at least one of the Tracking Area Identifier (TAI), Cell Global Identifier (CGI), and Public Land Mobile Network Identity (PLMN ID). Correspondingly, the second indication information includes some information required by the core network device to determine the second network device, and the sixth indication information includes another part of the information required by the core network device to determine the second network device. This is not limited to the identification information listed here, nor is the name of the identifier limited; it is merely an example.

[0273] In one possible example, after the first network device identifies the second network device, if the first network device discovers that there is no directly usable Xn interface between the first and second network devices, or for other reasons, the core network device needs to forward the message. Since the second indication information sent by the terminal device may not be sufficient for the core network device to address the second network device, the first network device can send a second request message to the terminal device to request more information so that the core network device can address the second network device. Accordingly, after receiving the second request message, the terminal device sends a second message to the first network device. The second message includes sixth indication information, which includes additional information needed by the core network device to identify the second network device besides the second indication information. The first network device sends a third message to the core network device, which includes the sixth indication information and / or the second indication information. After receiving the third message, the core network device addresses the second network device according to the third message and sends a notification message to the second network device to notify the second network device that a certain terminal device subscribing to the first multicast service has left the cell of the second network device. After receiving the notification message, the second network device updates the number of terminal devices subscribing to the first multicast service in the cell or service area of ​​the second network device according to the notification message. In this case, since the terminal device has already reported some information for addressing the second network device in the second indication information, it does not need to report it again in the sixth indication information. Only the additional information required by the core network device for addressing the second network device needs to be reported. The content of the indication information in all embodiments of this invention is not limited to the identification information listed therein, nor is the name of the identification limited; it is merely an example.

[0274] In one alternative approach, the first network device receives a handover request message from the second network device.

[0275] Specifically, the handover request message includes fourth indication information, which includes the identification information of the first multicast service.

[0276] Specifically, if the terminal device is in a connected state, and the terminal device receiving the first multicast service moves, if the handover conditions are met, that is, the terminal device sends a measurement report to the second network device (source base station). The second network device knows from the measurement report that the service quality of the current cell of the terminal device is poor. Then, the second network device determines the first network device (target base station) where the cell with better signal quality is located based on the measurement report, and sends a handover request message to the first network device. After the first network device replies with a confirmation message to the second network device, the second network device sends a handover command to the terminal device. The terminal device switches to the cell of the first network device and communicates with the first network device to complete the handover process. When switching from one cell to another, the second network device can learn that a terminal device subscribing to the first multicast service has left, thus indicating that one less terminal device is subscribing to the first multicast service in the second network device's serving cell. Furthermore, the second network device can carry a fourth indication information in the handover request message, instructing the terminal device to subscribe to the first multicast service. The first network device can then learn from the fourth indication information that one more terminal device has subscribed to the first multicast service in its serving cell. Therefore, after a connected UE moves, both the first and second network devices can update the number of terminal devices subscribing to the first multicast service through the handover process.

[0277] Through the communication method provided in this application embodiment, the first network device can determine that a terminal device in the cell of the second network device is switching to the cell of the first network device by receiving a handover request message from the second network device. This is beneficial for the first network device to update the number of terminal devices subscribing to the first multicast service in a timely manner, thereby maintaining the transmission of the multicast service more accurately.

[0278] Step S403: The first network device receives the first instruction information from the terminal device.

[0279] Optionally, embodiments of this application further include the following steps:

[0280] Step S404: The first network device determines the receiving status of the terminal device according to the first instruction information.

[0281] Specifically, the meaning of the first indication information and the receiving status is explained in step S402, and will not be repeated here.

[0282] For example, when the first indication information includes the identification information of the first multicast service and the identification information of the terminal device, the first network device can determine which specific terminal device sent the first indication information based on the identification information of the terminal device. Assuming that the identification information of the terminal device was not previously maintained for the first multicast service, the first network device can determine which specific terminal device subscribes to the first multicast service through the first indication information, thereby determining that the number of terminal devices subscribing to the first multicast service has increased by one. Assuming that the identification information of the terminal device was previously maintained for the first multicast service, the first network device can determine which specific terminal device does not subscribe to the first multicast service through the first indication information, thereby determining that the number of terminal devices subscribing to the first multicast service has decreased by one.

[0283] For example, the first indication information includes identification information of the first multicast service and a start indication. The start indication is used to instruct the terminal device to subscribe to the first multicast service. In this case, the first network device determines that there is one more terminal device subscribing to the first multicast service through the start indication. Alternatively, the first indication information includes identification information of the first multicast service and a stop indication. The stop indication is used to instruct the terminal device not to subscribe to the first multicast service. In this case, the first network device determines that there is one less terminal device subscribing to the first multicast service through the stop indication.

[0284] Step S405: The first network device determines the number of terminal devices that subscribe to the first multicast service based on the receiving status of the terminal device.

[0285] Specifically, if the receiving state of the terminal device is subscribed to the first multicast service, the first network device determines that the number of terminal devices subscribed to the first multicast service increases by 1; if the receiving state of the terminal device is not subscribed to the first multicast service, the first network device determines that the number of terminal devices subscribed to the first multicast service decreases by 1.

[0286] Step S406: The first network device determines the transmission strategy of the first multicast service based on the number of terminal devices that have subscribed to the first multicast service.

[0287] Specifically, the number of terminal devices subscribing to the first multicast service refers to the number of terminal devices that have started receiving the first multicast service, are currently receiving the first multicast service, are about to receive the first multicast service, wish to (expect) receive the first multicast service, or are interested in receiving the first multicast service. The transmission strategy is related to the number of terminal devices and is used to maintain the transmission of the multicast service. The transmission strategy includes establishing, modifying, or releasing MBMS service transmission channels (such as MBMS PDU SESSION, QoS flow, or GTP-U tunnel), and sending the first multicast service using a dedicated bearer or using multicast, etc.

[0288] For example, when the number of terminal devices subscribing to the first multicast service exceeds a first threshold, if unicast transmission is used, a dedicated bearer needs to be established for each terminal device to transmit the service, consuming a large amount of resources. To avoid this waste, the first network device can use multicast transmission when the number of terminal devices subscribing to the first multicast service exceeds the first threshold. When the number of terminal devices subscribing to the first multicast service is less than a second threshold, the first network device can establish a dedicated bearer for each terminal device to transmit the service. When there are no terminal devices subscribing to the first multicast service in the cell of the first network device, the first network device sends an indication message to the core network device, instructing the core network device to release the multicast service transmission channel between the core network device and the first network device and stop the transmission of the first multicast service. When the number of terminal devices subscribing to the first multicast service in the cell of the first network device increases from zero to many, the first network device sends an indication message to the core network device, instructing the core network device to establish a multicast service transmission channel between the core network device and the first network device and start the transmission of the first multicast service. Alternatively, the established multicast service transmission channel can also be modified.

[0289] exist Figure 4 In the method described above, when a terminal device subscribes to the first multicast service within a cell, it needs to report to the network device; when the terminal device moves, it also needs to report to the network device. In this way, the network device can know the number of terminal devices subscribing to the first multicast service in each cell in real time, and maintain the transmission of the multicast service based on the number.

[0290] Please see Figure 5 , Figure 5 This is another communication method provided in the embodiments of this application, which includes, but is not limited to, the following steps:

[0291] Step S501: The terminal device determines the reception status of the first service.

[0292] Specifically, step S501 is an optional step. The first service can be a multicast service, a unicast service, or other services; this solution does not limit this.

[0293] Specifically, the receiving status is used to indicate the receiving status, subscription status, or interest status of the terminal device regarding the first service, including at least one of: starting to receive the first service, currently receiving the first service, stopping receiving the first service, about to receive the first service, hoping to receive the first service, interested in receiving the first service, and not interested in receiving the first service. The receiving status can also be referred to as "interested" or "not interested." Correspondingly, the terminal device determining that it is interested in the first service means that it has started receiving the first service, is currently receiving the first service, is about to receive the first service, or hopes to receive the first service. The terminal device determining that it is not interested in the first service means that it has stopped receiving or is not interested in receiving the first service. It should be noted that in the following steps, the terminal device needs to send the receiving status to the network device so that the network device can determine whether the terminal device needs to receive the first service. Furthermore, the network device can count the number of terminal devices interested in the first service. That is, the receiving status is used to indicate whether the terminal device expects to receive the first service or does not expect to receive the first service. This application embodiment does not limit the specific definition and sending form of the receiving status; the first service will be specifically described below using the first multicast service as an example.

[0294] Step S502: The terminal device sends the first instruction information to the first core network device or application server.

[0295] Specifically, the first indication information is forwarded by the terminal device to the first core network device or application server via the first network device. The first indication information is used to indicate the terminal device's reception status of the first multicast service, and the first indication information includes the identification information of the first multicast service, such as a temporary mobile group identity (TMGI) or other identification information used to identify the first multicast service. The first indication information also includes: identification information and second identification information of the terminal device. The identification information of the terminal device includes, for example, the International Mobile Subscriber Identification Number (IMSI), the Temporary Mobile Subscriber Identity (TMSI), the SAE-Temporary Mobile Subscriber Identity (S-TMSI), the Globally Unique Temporary UE Identity (GUTI), or the Cell-Radio Network Temporary Identifier (C-RNTI). The second identification information includes at least one of the following: Tracking Area Identity (TAI), Cell Global Identifier (CGI), and Public Land Mobile Network Identity (PLMN ID).

[0296] Specifically, when the terminal device is in an idle or inactive state, the first indication information can be carried in a message during the random access process. The random access message is Msg1, Msg3, Msg5, or MsgA, and the random access can be a four-step random access or a two-step random access. When the terminal device is in a connected state, the first indication information is carried in a media access control element (MAC CE), a control protocol data unit (Control PDU), or an RRC message.

[0297] Optionally, before step S502, this embodiment further includes step S5021, whereby the terminal device determines to send the first instruction information via the network device to the first core network device or application server. For details, please refer to step S4021 above, which will not be repeated here.

[0298] Optionally, step S5022 is included before step S502: the network device instructs the terminal device whether to report the subscription status. Accordingly, the terminal device determines whether to report the subscription status based on the instruction information from the network device. For the definition of step S5022, please refer to the relevant description of step S4022, which will not be repeated here.

[0299] In one alternative approach, when the terminal device changes its reception status for the first multicast service, the terminal device sends the first indication information to the first core network device or application server via the network device.

[0300] Specifically, the change in reception status could be a change from subscribing to the first multicast service to not subscribing to the first multicast service, and so on.

[0301] For example, if a terminal device determines that its reception status for the first multicast service has changed from subscribing to not subscribing to the first multicast service, then the terminal device sends a first instruction message to the first core network device or application server via the network device. Accordingly, the first core network device or application server determines, based on the first instruction message, that the number of terminal devices subscribing to the first multicast service within the cell of the first core network device or the cell of the application server decreases by one.

[0302] For example, if a terminal device determines that its reception status for the first multicast service changes from not subscribing to subscribing to the first multicast service, the terminal device sends a first instruction message to the first core network device or application server via the network device. Accordingly, the first core network device or application server determines, based on the first instruction message, that the number of terminal devices subscribing to the first multicast service within the cell of the first core network device or the cell of the application server increases by one.

[0303] In one alternative approach, when the RRC status of a terminal device changes, the terminal device sends the first indication information to the first core network device or application server via a network device.

[0304] Specifically, before the RRC status of the terminal device changes, the terminal device sends the first indication information to the first core network device or application server via the network device, and / or after the RRC status of the terminal device changes, the terminal device sends the first indication information to the first core network device or application server via the network device.

[0305] For example, if the RRC state of a terminal device changes from connected to idle, the terminal device reports the first indication information when it was in connected state before the change and / or reports the first indication information when it is in idle state after the change.

[0306] For example, if the RRC state of a terminal device changes from an inactive state to a connected state, the terminal device will report the first indication information when it was in an inactive state before the change, and / or the terminal device will report the first indication information when it is in a connected state after the change.

[0307] In one alternative approach, after the RRC connection of the terminal device is rebuilt, reconfigured, or restored, the terminal device sends the first instruction information to the first core network device or application server via the network device.

[0308] Specifically, when a terminal device is in a connected state, if a handover failure, radio link failure, integrity protection failure, or RRC reconfiguration failure occurs, an RRC connection reconstruction process will be triggered. During or after the reconstruction process, the terminal device can send a first indication message to the first core network device or application server via the network device. When the network device reconfigures parameters for a connected terminal device, it sends an RRC reconfiguration command. After reconfiguration, the terminal device can send a first indication message to the first core network device or application server via the network device. When a terminal device transitions from an inactive state to a connected state, an RRC recovery process will be triggered. During or after the RRC recovery process, the terminal device can send a first indication message to the first core network device or application server via the network device.

[0309] In one alternative approach, the first core network device or application server receives second instruction information from the first network device.

[0310] Specifically, the second indication information is used to indicate that the terminal device has arrived at the cell of the first core network device. The second indication information includes at least one of the identification information of the first multicast service, the identification information of the terminal device, the identification information of the source network device, and the identification information of the first network device. Optionally, the second indication information may also include arrival indication information.

[0311] Specifically, if the terminal device is in a connected state, and the terminal device receiving the first multicast service moves, if the handover conditions are met, it will switch from one cell to another. If the handover process executes a path handover procedure, if the terminal device switches from the cell of the second network device to the cell of the first network device, the second network device sends a handover request message to the first network device, the first network device replies with a confirmation message to the second network device, and after receiving the confirmation message, the second network device sends a notification message to the first core network device, notifying the first core network device that the second network device is about to perform a handover. The first core network device addresses the first network device according to the instruction information including the identification information of the first network device sent by the second network device, establishes a connection with the first network device, and the core network device releases the connection between the second network device and the second network device. The first core network device will determine when a terminal device under the second network device switches to the first network device. The first core network device can know from which terminal device switches to which location through the path handover process, thereby updating the number of terminal devices in each cell. If the path handover process is not executed, the first network device after the handover sends a second indication message to the first core network device to instruct the terminal device to arrive at the cell of the first network device, or the second network device before the handover sends an indication message to the first core network device to instruct the terminal device to leave the cell of the second network device. Accordingly, the first core network device can update the number of terminal devices subscribing to the first multicast service based on the indication message.

[0312] In one alternative approach, after performing cell reselection, changing the serving cell, or changing the serving area (e.g., a multicast service area, which may include at least one cell), the terminal device sends the third instruction information to the first core network device or application server.

[0313] Specifically, the third indication information includes the first identification information and the identification information of the first multicast service. The first identification information includes the identification information of the source network device and / or the identification information of the terminal device.

[0314] Specifically, after performing cell reselection, changing the serving cell, or changing the service area (e.g., a multicast service area, which may include at least one cell), the terminal device forwards the third instruction information to the first core network device via the network device. After receiving the third instruction information from the terminal device, the first core network device addresses the second network device based on the identification information of the source network device or the identification information of the terminal device (e.g., the identification information of an inactive terminal device). Then, the first core network device sends a notification message to the second network device. This notification message is used to notify the second network device that the terminal devices subscribed to the first multicast service have left the cell of the second network device. Accordingly, the second network device updates the number of terminal devices subscribed to the first multicast service.

[0315] In one alternative approach, a first core network device or application server sends a request message to a second core network device, the request message being used to request context information of the terminal device; the first core network device or application server receives the context information from the second core network device, the context information including the identification information of the first multicast service.

[0316] Specifically, each core network device maintains a registration area. If a terminal device moves from the registration area of ​​the second core network device to the registration area of ​​the first core network device, it will re-initiate a registration process or a registration update process with the first core network device. The first core network device determines that the terminal device moved from the second core network device through the registration process or registration update process initiated by the terminal device. Then, the first core network device sends a request message to the second core network device, requesting the context information of the terminal device. The second core network device determines that a terminal device has left based on the request message and updates the number of terminal devices subscribing to the first multicast service in the cell of the second core network device. When the second core network device sends context information to the first core network device, the context information includes the identification information of the first multicast service that the terminal device is interested in receiving or is currently receiving. Accordingly, the first core network device updates the number of terminal devices subscribing to the first multicast service in the cell of the first core network device based on the context information.

[0317] Step S503: The first core network device or application server receives the first instruction information from the terminal device.

[0318] Optionally, embodiments of this application further include the following steps:

[0319] Step S504: The first core network device or application server determines the receiving status of the terminal device based on the first instruction information.

[0320] For a specific implementation method, please refer to step S404 in the above embodiment. This step will not be repeated here.

[0321] Step S505: The first core network device or application server determines the number of terminal devices that subscribe to the first multicast service based on the receiving status of the terminal device.

[0322] Optionally, the first core network device or application server forwards the reception status of the terminal device to the first network device, which then counts and determines the number of terminal devices subscribing to the first multicast service and determines the transmission strategy for the first multicast service.

[0323] For a specific implementation method, please refer to step S405 in the above embodiment. This step will not be repeated here.

[0324] Step S506: The first core network device or application server determines the transmission strategy of the first multicast service based on the number of terminal devices subscribing to the first multicast service.

[0325] Specifically, the number of terminal devices subscribing to the first multicast service refers to the number of terminal devices that have started receiving the first multicast service, are currently receiving the first multicast service, are about to receive the first multicast service, wish to (expect) receive the first multicast service, or are interested in receiving the first multicast service. The transmission strategy is related to the number of terminal devices and is used to maintain the transmission of the multicast service. The transmission strategy includes establishing, modifying, or releasing MBMS service transmission channels (such as MBMS PDU SESSION, QoS flow, or GTP-U tunnel), and sending the first multicast service using a dedicated bearer or using multicast, etc.

[0326] Optionally, the core network device or application server sends the number of terminal devices subscribing to the first multicast service to the first network device, which then determines the transmission strategy for the first multicast service.

[0327] For example, when there are no terminal devices subscribed to the first multicast service in the cell of the core network equipment, the core network equipment releases the multicast service transmission channel with the first network equipment and stops sending the first multicast service; while when the number of terminal devices subscribed to the first multicast service in the cell of the core network equipment increases from zero to one, the core network equipment establishes a multicast service transmission channel with the first network equipment and starts sending the first multicast service; alternatively, the established multicast service transmission channel can also be modified.

[0328] exist Figure 5 In the method described above, when a terminal device subscribes to the first multicast service within a cell, it needs to report to the core network device or application server. When the terminal device moves, it also needs to report to the core network device or application server. In this way, the core network device / application server can know the number of terminal devices subscribing to the first multicast service in each cell in real time and maintain the transmission of the multicast service based on the number.

[0329] Please see Figure 6 , Figure 6 This is another communication method provided in the embodiments of this application, which includes, but is not limited to, the following steps:

[0330] Step S601: The first network device determines the second network device.

[0331] Specifically, the first network device determines the second network device based on the identification information from the inactive terminal device.

[0332] For example, the first network device determines the second network device based on the I-RNTI.

[0333] Step S602: The first network device sends a request message to the second network device.

[0334] Specifically, the request information is used to obtain the context information of the terminal device.

[0335] Specifically, after the first network device sends a request message to the second network device, the second network device receives the request message and determines, based on the request message, that the terminal device subscribing to the first multicast service has left the cell of the second network device. Thus, it can be known that one less terminal device is subscribing to the first multicast service in the cell of the second network device.

[0336] Step S603: The second network device receives a request from the first network device.

[0337] Step S604: The second network device sends the context information of the terminal device to the first network device.

[0338] Specifically, the context information includes the identification information of the first multicast service.

[0339] Step S605: The first network device receives context information from the second network device terminal device.

[0340] Specifically, the context information includes the identification information of the first multicast service. After receiving the context information, the first network device determines that the terminal device has subscribed to the first multicast service based on the identification information of the first multicast service in the context information. Thus, the first network device can know from the context information that one more user has subscribed to the first multicast service in its cell.

[0341] In one alternative configuration, the first network device is configured such that the Radio Access Network (RAN) notification area includes only one cell.

[0342] Specifically, each RNA contains a list of cells. It is stipulated that each RNA contains only one cell. When the RNA timer of the terminal device expires or the terminal device moves out of the RNA range, the RNAU process will be initiated. If the RNAU process is initiated, the first network device will request the context of the terminal device from the second network device. The second network device can determine that the terminal device subscribing to the first multicast service in the cell of the second network device has left, and thus know that the number of terminal devices subscribing to the first multicast service in the cell of the second network device has decreased by one.

[0343] In one alternative approach, a first network device receives first indication information from a terminal device. The first indication information is used to indicate the terminal device's reception status of a first multicast service, and the first indication information includes the identification information of the first multicast service.

[0344] The specific implementation method is as described in step 402 of the above embodiments, and will not be repeated here.

[0345] exist Figure 6 The method described herein is for terminal devices in an inactive state. For terminal devices in an idle state that wish to receive multicast services, they can optionally enter an inactive state first, allowing them to use this method for information reporting. This embodiment can reuse existing RNAU procedures as much as possible to count the number of terminal devices interested in receiving the first multicast service, improving the communication efficiency of the communication system. Furthermore, because the RNAU procedure has security protection enabled, it is more secure than reporting from idle terminal devices. This method can restrict information reporting by idle terminal devices, preventing malicious reporting by idle terminal devices that could lead to errors in network device statistics.

[0346] The methods of the embodiments of this application have been described in detail above, and the apparatus of the embodiments of this application is provided below.

[0347] Please see Figure 7 , Figure 7 This is a schematic diagram of a communication device provided in an embodiment of this application. The communication device can be the aforementioned terminal device, or a component within the terminal device. The communication device may include a processing unit 701 and a communication unit 702, wherein each unit is described in detail below.

[0348] Processing unit 701 is used to determine the reception status of the first multicast service;

[0349] The communication unit 702 is used to send first indication information to the first network device. The first indication information is used to indicate the reception status of the terminal device for the first multicast service. The first indication information includes the identification information of the first multicast service.

[0350] In one alternative embodiment, the receiving state includes at least one of: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

[0351] In another alternative, the first indication information may also include the identification information of the terminal device.

[0352] In another alternative embodiment, the communication unit 702 is further configured to receive scheduling information from the first network device, the scheduling information being used to indicate the time-frequency resources of the first indication information, and the scheduling information being carried in system information, radio resource control (RRC) signaling, random access message, or downlink control information (DCI).

[0353] In another alternative embodiment, the processing unit 701 is further configured to start a timer; the processing unit 701 is further configured to determine that the timer has timed out; and the communication unit 702 is further configured to send the first indication information to the first network device.

[0354] In another alternative embodiment, the communication unit 702 is further configured to send the second indication information to the first network device after performing cell reselection or changing the serving cell. The second indication information includes first identification information and identification information of the first multicast service. The first identification information includes identification information of the source network device and / or identification information of the terminal device.

[0355] It should be noted that the implementation and beneficial effects of each unit can be found by referring to [the relevant documentation / reference]. Figure 4 The corresponding description of the method embodiments shown.

[0356] Please see Figure 8 , Figure 8 This is a schematic diagram of a communication device provided in an embodiment of this application. The communication device can be the first network device described above, or a component within the first network device. The communication device may include a communication unit 801 and a processing unit 802, wherein each unit is described in detail below.

[0357] The communication unit 801 is configured to receive first indication information from a terminal device, the first indication information being used to indicate the reception status of the terminal device for a first multicast service, the first indication information including the identification information of the first multicast service;

[0358] Processing unit 802 is used to determine the receiving status of the terminal device based on the first indication information.

[0359] In one alternative embodiment, the receiving state includes at least one of: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

[0360] In another alternative, the first indication information may also include the identification information of the terminal device.

[0361] In another alternative embodiment, the communication unit 801 is further configured to send scheduling information to the terminal device. The scheduling information is used to indicate the time and frequency resources of the first indication information. The scheduling information is carried in system information, radio resource control (RRC) signaling, random access message, or downlink control information (DCI).

[0362] In another alternative embodiment, the processing unit 802 is further configured to determine a second network device based on second indication information from the terminal device, the second indication information including identification information of the first multicast service and first identification information, the first identification information including identification information of the second network device and / or identification information of the terminal device.

[0363] In another alternative embodiment, the communication unit 801 is further configured to send third indication information to the second network device, the third indication information being used to instruct the terminal device to leave, the third indication information including the identification information of the first multicast service and / or the identification information of the terminal device.

[0364] In another alternative embodiment, the communication unit 801 is further configured to receive a handover request message from the second network device, the handover request message including fourth indication information, the fourth indication information including the identification information of the first multicast service.

[0365] In another alternative embodiment, the communication unit 801 is further configured to send a fifth indication information to the core network equipment. The fifth indication information includes the identification information of the first multicast service, the identification information of the terminal equipment, and a second identification information. The second identification information includes at least one of the Tracking Area Identifier (TAI), the Cell Global Identifier (CGI), and the Public Land Mobile Network Identity (PLMN ID).

[0366] It should be noted that the implementation and beneficial effects of each unit can be found by referring to [the relevant documentation / reference]. Figure 4 The corresponding description of the method embodiments shown.

[0367] Please see Figure 9 , Figure 9 This application provides a communication device 900, which includes a processor 901 and a transceiver 903. Optionally, the communication device 900 also includes a memory 902. The processor 901, memory 902 and transceiver 903 are interconnected via a bus 904.

[0368] The memory 902 includes, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), or compact disc read-only memory (CD-ROM), and is used for related computer programs and data. The transceiver 903 is used to receive and transmit data.

[0369] Processor 901 can be one or more central processing units (CPUs). If processor 901 is a CPU, the CPU can be a single-core CPU or a multi-core CPU.

[0370] The processor 901 in the device 900 reads the computer program stored in the memory 902 and performs the following operations:

[0371] Determine the reception status of the first multicast service;

[0372] Send a first indication message to a first network device. The first indication message is used to indicate the reception status of the terminal device for the first multicast service. The first indication message includes the identification information of the first multicast service.

[0373] In one alternative embodiment, the receiving state includes at least one of: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

[0374] In another alternative, the first indication information may also include the identification information of the terminal device.

[0375] In another alternative scheme, processor 901 is configured to receive scheduling information from the first network device via transceiver 903, the scheduling information being used to indicate the time-frequency resources of the first indication information, and the scheduling information being carried in system information, radio resource control (RRC) signaling, random access message, or downlink control information (DCI).

[0376] In another alternative embodiment, processor 901 is further configured to start a timer; determine that the timer has timed out; and send the first indication information to the first network device via transceiver 903.

[0377] In another alternative embodiment, processor 901 is configured to send the second indication information to the first network device via transceiver 903 after performing cell reselection or changing the serving cell. The second indication information includes first identification information and identification information of the first multicast service. The first identification information includes identification information of the source network device and / or identification information of the terminal device.

[0378] It should be noted that the implementation and beneficial effects of each operation can be found by referring to [the relevant documentation / reference]. Figure 4 The corresponding description of the method embodiments shown.

[0379] Please see Figure 10 , Figure 10 This application provides a communication device 1000, which includes a processor 1001 and a transceiver 1003. Optionally, the communication device 1000 also includes a memory 1002. The processor 1001, memory 1002 and transceiver 1003 are interconnected via a bus 1004.

[0380] The memory 1002 includes, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), or compact disc read-only memory (CD-ROM), and is used for related computer programs and data. The transceiver 1003 is used to receive and transmit data.

[0381] The processor 1001 can be one or more central processing units (CPUs). If the processor 1001 is a CPU, the CPU can be a single-core CPU or a multi-core CPU.

[0382] The processor 1001 in the device 1000 reads the computer program stored in the memory 1002 and performs the following operations:

[0383] Receive first indication information from terminal device, the first indication information being used to indicate the reception status of the terminal device for the first multicast service, the first indication information including the identification information of the first multicast service;

[0384] The receiving status of the terminal device is determined based on the first indication information.

[0385] In one alternative embodiment, the receiving state includes at least one of: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

[0386] In another alternative, the first indication information may also include the identification information of the terminal device.

[0387] In another alternative embodiment, the processor 1001 is further configured to send scheduling information to the terminal device via transceiver 1003. The scheduling information is used to indicate the time and frequency resources of the first indication information, and the scheduling information is carried in system information, radio resource control (RRC) signaling, random access message, or downlink control information (DCI).

[0388] In another alternative embodiment, the processor 1001 is further configured to determine a second network device based on second indication information from the terminal device, the second indication information including identification information of the first multicast service and first identification information, the first identification information including identification information of the second network device and / or identification information of the terminal device.

[0389] In another alternative embodiment, the processor 1001 is further configured to send third indication information to the second network device via transceiver 1003, the third indication information being used to instruct the terminal device to leave, the third indication information including the identification information of the first multicast service and / or the identification information of the terminal device.

[0390] In another alternative embodiment, the processor 1001 is further configured to send fifth indication information to the core network equipment via transceiver 1003. The fifth indication information includes the identification information of the first multicast service, the identification information of the terminal equipment, and second identification information. The second identification information includes at least one of Tracking Area Identifier (TAI), Cell Global Identifier (CGI), and Public Land Mobile Network Identity (PLMN ID).

[0391] It should be noted that the implementation and beneficial effects of each operation can be found by referring to [the relevant documentation / reference]. Figure 4 The corresponding description of the method embodiments shown.

[0392] This application embodiment also provides a chip system, the chip system including at least one processor, a memory, and interface circuitry, the memory, the transceiver, and the at least one processor being interconnected via circuitry, the at least one memory storing a computer program; when the computer program is executed by the processor, it implements... Figure 4The operation or implementation of the terminal device in the illustrated embodiment Figure 4 The operation of the first network device in the illustrated embodiment is implemented. Figure 5 The operation or implementation of the terminal device in the illustrated embodiment Figure 5 The operation of the first core network device or server in the illustrated embodiment is implemented. Figure 6 The operation or implementation of the first network device in the illustrated embodiment Figure 6 The operation of the second network device in the illustrated embodiment.

[0393] This application also provides a computer-readable storage medium storing a computer program that, when run on a processor, implements... Figure 4 The operation or implementation of the terminal device in the illustrated embodiment Figure 4 The operation of the first network device in the illustrated embodiment is implemented. Figure 5 The operation or implementation of the terminal device in the illustrated embodiment Figure 5 The operation of the first core network device or server in the illustrated embodiment is implemented. Figure 6 The operation or implementation of the first network device in the illustrated embodiment Figure 6 The operation of the second network device in the illustrated embodiment.

[0394] This application embodiment also provides a communication system, which includes a terminal device, a first core network device or server, a first network device, and a second network device. When the system runs on the terminal device, network device, core network device, or application server, it implements... Figure 4 The operation or implementation of the terminal device in the illustrated embodiment Figure 4 The operation of the first network device in the illustrated embodiment is implemented. Figure 5 The operation or implementation of the terminal device in the illustrated embodiment Figure 5 The operation of the first core network device or server in the illustrated embodiment is implemented. Figure 6 The operation or implementation of the first network device in the illustrated embodiment Figure 6 The operation of the second network device in the illustrated embodiment.

[0395] This application also provides a computer program product that, when run on a processor, implements... Figure 4 The operation or implementation of the terminal device in the illustrated embodiment Figure 4 The operation of the first network device in the illustrated embodiment is implemented. Figure 5 The operation or implementation of the terminal device in the illustrated embodiment Figure 5 The operation of the first core network device or server in the illustrated embodiment is implemented. Figure 6 The operation or implementation of the first network device in the illustrated embodiment Figure 6The operation of the second network device in the illustrated embodiment.

[0396] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program using computer program-related hardware. The computer program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The aforementioned storage medium includes various media capable of storing computer program code, such as ROM or random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A communication method, characterized in that, The method is applicable to terminal devices and includes: Determine the reception status of the first multicast service; Send a first indication message to a first network device. The first indication message is used to indicate the reception status of the terminal device for the first multicast service. The first indication message includes the identification information of the first multicast service. After performing cell reselection or changing the serving cell, a second indication information is sent to the first network device. The second indication information includes a first identification information and an identification information of the first multicast service. The first identification information includes the identification information of the source network device and / or the identification information of the terminal device. The first identification information is used by the first network device to determine the second network device, and the identification information of the first multicast service is used by the second network device to update the number of terminal devices subscribing to the first multicast service.

2. The method according to claim 1, characterized in that, The receiving state includes at least one of the following: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

3. The method according to claim 1 or 2, characterized in that, The first indication information also includes the identification information of the terminal device.

4. The method according to claim 1 or 2, characterized in that, The method further includes: The system receives scheduling information from the first network device. The scheduling information is used to indicate the time and frequency resources of the first indication information. The scheduling information is carried in system information, radio resource control (RRC) signaling, random access message, or downlink control information (DCI).

5. The method according to claim 1 or 2, characterized in that, After sending the first indication information to the first network device, the method further includes: Start the timer; Determine that the timer has timed out; Send the first instruction information to the first network device.

6. The method according to claim 1 or 2, characterized in that, Sending the first indication information to the first network device includes: When the RRC status of the terminal device changes, a first indication message is sent to the first network device.

7. The method according to claim 1 or 2, characterized in that, Sending the first indication information to the first network device includes: After the terminal device undergoes an RRC reconstruction, RRC reconfiguration, or RRC recovery process, it sends a first indication message to the first network device.

8. A communication method, characterized in that, The method is applicable to a first network device and includes: Receive first indication information from terminal device, the first indication information being used to indicate the reception status of the terminal device for the first multicast service, the first indication information including the identification information of the first multicast service; The receiving status of the terminal device is determined based on the first indication information; The second network device is determined based on the second indication information from the terminal device. The second indication information includes the identification information of the first multicast service and the first identification information. The first identification information includes the identification information of the second network device and / or the identification information of the terminal device. The first identification information is used by the first network device to determine the second network device, and the identification information of the first multicast service is used by the second network device to update the number of terminal devices subscribing to the first multicast service.

9. The method according to claim 8, characterized in that, The receiving state includes at least one of the following: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

10. The method according to claim 8 or 9, characterized in that, The first indication information also includes the identification information of the terminal device.

11. The method according to claim 8 or 9, characterized in that, The method further includes: The scheduling information is sent to the terminal device. The scheduling information is used to indicate the time and frequency resources of the first indication information. The scheduling information is carried in system information, radio resource control (RRC) signaling, random access message, or downlink control information (DCI).

12. The method according to claim 8 or 9, characterized in that, The method further includes: Send a third indication message to the second network device. The third indication message is used to instruct the terminal device to leave. The third indication message includes the identification information of the first multicast service and / or the identification information of the terminal device.

13. The method according to claim 8 or 9, characterized in that, The method further includes: A handover request message is received from the second network device. The handover request message includes fourth indication information, which includes the identification information of the first multicast service.

14. The method according to claim 8 or 9, characterized in that, The method further includes: Send a fifth instruction message to the core network equipment. The fifth instruction message includes the identification information of the first multicast service, the identification information of the terminal equipment, and the second identification information. The second identification information includes at least one of the Tracking Area Identifier (TAI), Cell Global Identifier (CGI), and Public Land Mobile Network Identity (PLMN ID).

15. A communication device, characterized in that, include: The processing unit is used to determine the reception status of the first multicast service; A communication unit is configured to send first indication information to a first network device, the first indication information being used to indicate the reception status of the communication device for a first multicast service, the first indication information including the identification information of the first multicast service; The communication unit is further configured to send second indication information to the first network device after performing cell reselection or changing the serving cell. The second indication information includes first identification information and identification information of the first multicast service. The first identification information includes identification information of the source network device and / or identification information of the communication device. The first identification information is used by the first network device to determine the second network device, and the identification information of the first multicast service is used by the second network device to update the number of communication devices subscribing to the first multicast service.

16. The apparatus according to claim 15, characterized in that, The receiving state includes at least one of the following: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

17. The apparatus according to claim 15 or 16, characterized in that, The first indication information also includes the identification information of the communication device.

18. The apparatus according to claim 15 or 16, characterized in that, The communication unit is further configured to receive scheduling information from the first network device. The scheduling information is used to indicate the time and frequency resources of the first indication information. The scheduling information is carried in system information, radio resource control (RRC) signaling, random access message, or downlink control information (DCI).

19. The apparatus according to claim 15 or 16, characterized in that, The processing unit is also used to start a timer; The processing unit is also configured to determine when the timer times out; The communication unit is also used to send the first indication information to the first network device.

20. The apparatus according to claim 15 or 16, characterized in that, The communication unit is configured to send a first indication message to the first network device when the RRC status of the communication device changes.

21. The apparatus according to claim 15 or 16, characterized in that, The communication unit is used to send a first indication message to the first network device after the communication device undergoes an RRC reconstruction, RRC reconfiguration, or RRC recovery process.

22. A communication device, characterized in that, include: A communication unit is configured to receive first indication information from a terminal device, the first indication information being used to indicate the reception status of the terminal device for a first multicast service, the first indication information including the identification information of the first multicast service; The processing unit is configured to determine the reception status of the terminal device based on the first indication information; the processing unit is further configured to determine a second network device based on second indication information from the terminal device, the second indication information including the identification information of the first multicast service and first identification information, the first identification information including the identification information of the second network device and / or the identification information of the terminal device, the first identification information being used by the communication device to determine the second network device, and the identification information of the first multicast service being used by the second network device to update the number of terminal devices subscribing to the first multicast service.

23. The apparatus according to claim 22, characterized in that, The receiving state includes at least one of the following: starting to receive the first multicast service, receiving the first multicast service, stopping receiving the first multicast service, about to receive the first multicast service, wishing to receive the first multicast service, being interested in receiving the first multicast service, and not being interested in receiving the first multicast service.

24. The apparatus according to claim 22 or 23, characterized in that, The first indication information also includes the identification information of the terminal device.

25. The apparatus according to claim 22 or 23, characterized in that, The communication unit is further configured to send scheduling information to the terminal device. The scheduling information is used to indicate the time and frequency resources of the first indication information. The scheduling information is carried in system information, radio resource control (RRC) signaling, random access message, or downlink control information (DCI).

26. The apparatus according to claim 22 or 23, characterized in that, The communication unit is further configured to send a third indication information to the second network device, the third indication information being used to instruct the terminal device to leave, the third indication information including the identification information of the first multicast service and / or the identification information of the terminal device.

27. The apparatus according to claim 22 or 23, characterized in that, The communication unit is further configured to receive a handover request message from the second network device, the handover request message including fourth indication information, the fourth indication information including the identification information of the first multicast service.

28. The apparatus according to claim 22 or 23, characterized in that, The communication unit is further configured to send a fifth indication information to the core network equipment. The fifth indication information includes the identification information of the first multicast service, the identification information of the terminal equipment, and the second identification information. The second identification information includes at least one of Tracking Area Identifier (TAI), Cell Global Identifier (CGI), and Public Land Mobile Network Identity (PLMNID).

29. A communication device, characterized in that, It includes at least one processor and a transceiver, wherein the at least one processor is used to communicate with other devices via the transceiver, the memory is used to store a computer program, and the processor invokes the computer program to perform the method as described in any one of claims 1 to 14.

30. A computer-readable storage medium, characterized in that, The computer storage medium stores a computer program that, when executed by a processor, causes the processor to perform the method as described in any one of claims 1-14.

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