WO2021226757A1

WO2021226757A1 - Multicast service transmission method, and network device

Info

Publication number: WO2021226757A1
Application number: PCT/CN2020/089456
Authority: WO
Inventors: 徐艺珊; 李濛; 诸华林
Original assignee: 华为技术有限公司
Priority date: 2020-05-09
Filing date: 2020-05-09
Publication date: 2021-11-18

Abstract

The embodiments of the present application relate to the technical field of wireless communications, and in particular to a multicast service transmission method and a network device. By means of the multicast service transmission method, a multicast session can be established on the basis of a network architecture that an operator has deployed, thereby saving on air interface resources. When the multicast service transmission method is applied to a first core network element, the method may comprise: a core network element receiving a first request, wherein the first request is used by a first user equipment to request the acquisition of multicast data corresponding to a multicast service, or the first request is used by the first user equipment to request departure from the multicast service; and when a first preset condition is satisfied, the first core network element sending first information to an access network element that serves the first user equipment, wherein the first information is used for indicating a mode in which the access network element transmits the multicast data corresponding to the multicast service, and the mode in which the multicast data is transmitted comprises unicast transmission or multicast transmission.

Description

Multicast service transmission method and network equipment

Technical field

The embodiments of the present application relate to the field of wireless communication technologies, and in particular, to a multicast service transmission method and network equipment.

Background technique

Internet Protocol Television (IPTV) is a type of broadband television. IPTV can also be called interactive network television. Among them, the IPTV data network can provide a data source of TV programs for user equipment. For example, an IPTV device on an IPTV data network may send the above-mentioned television program to a user equipment through a broadband network based on the Internet protocol (IP).

Please refer to FIG. 1, which shows a schematic diagram of an existing IPTV system. As shown in Figure 1, the network elements in the IPTV system may include an IPTV data network, a user plane function (UPF) and a radio access network (RAN). Among them, the set-to-box (STB) shown in FIG. 1 is the above-mentioned user equipment. The IPTV data network can send TV programs to STB (user equipment) in the following ways: IPTV data network can send TV programs to multiple UPFs by multicast (or called multicast); UPF can send TV programs to multiple UPFs in unicast mode. RAN sends TV programs; RAN sends TV programs to STB through 5G-residential gateway (5G-RG). Among them, in the IPTV system shown in FIG. 1, data transmission is performed between the 5G-RG and the RAN through an air interface.

It is understandable that the IPTV device sending a TV program to multiple UPFs by multicast means that the IPTV device only needs to send one TV program, and all the multiple UPFs can receive the TV program. When UPF sends TV programs to RAN in unicast mode, it means that when all three STBs request to obtain TV programs, UPF needs to send three TV programs to RAN, so that RAN can send three TV programs to the three 5G-RGs shown in Figure 1. Send TV shows. Assuming that three STBs request to obtain the same TV program, the UPF also needs to copy the TV program from the IPTV device into three copies and send them to the three 5G-RGs shown in Figure 1 respectively. UPF copies the same TV program into three copies and sends them to the same RAN, which occupies more network-side resources. In addition, when the RAN sends TV data to the 5G-RG, it needs to occupy three air interface resources for transmitting the same TV program. In this way, it causes a waste of air interface resources. Moreover, when there are more users watching the same TV program at the same time, the UPF needs to occupy more network-side resources, and the RAN needs to occupy a large amount of air interface resources for transmitting the same TV program, resulting in a lot of waste of air interface resources.

Summary of the invention

The present application provides a multicast service transmission method and network equipment, which can realize the establishment of a multicast session based on the network architecture deployed by the operator and save air interface resources.

In order to achieve the above objectives, this application adopts the following technical solutions:

In the first aspect, the present application provides a method for transmitting a multicast service. The method may be applied to a core network element. The method may include: the core network element receives a first request, the first request is for the first user equipment The multicast service is requested, or the first request is used for the first user equipment to request to leave the multicast service. That is, the first request is triggered by the first user equipment. It is understandable that the first user equipment needs to send a first request to the core network element through the access network element. Therefore, the core network element may determine according to the first request that the access network serving the first user equipment The number of user equipment that obtains the multicast service in the network element has changed. For example, the first request is that the first user equipment requests to obtain the multicast service, and the core network element may determine that the number of user equipments that obtain the multicast service among the user equipment connected to the access network element has increased. For another example, the first request is that the first user equipment requests to leave the multicast service, and the core network element may determine that the number of user equipments that obtain the multicast service among the user equipment connected to the access network element is reduced.

When the first preset condition is met, the core network element may send the first information to the access network element serving the first user equipment. The first information is used to indicate the manner in which the network element of the access network transmits the multicast data corresponding to the multicast service, and the manner in which the multicast data is transmitted includes unicast transmission and multicast transmission. In other words, the core network element can instruct the access network element to transmit the multicast data transmission mode. For example, the core network element may instruct the access network element serving the first user equipment to transmit multicast data in unicast transmission, and the core network element may also indicate the access network element serving the first user equipment. Transmit multicast data in the manner of multicast transmission. Since the core network element receives the first request, the number of user equipments in the access network element that receives the multicast data corresponding to the multicast service has changed. Therefore, the core network element can receive according to the access network element. The number of user equipments of the multicast data corresponding to the multicast service indicates the transmission mode of the network element of the access network to transmit the multicast data. In this way, the flexibility of the transmission method of the multicast data transmitted by the network element of the access network can be improved. Generally speaking, the access network element uses air interface resources to transmit multicast data. Therefore, the core network element instructs the access network element to send multicast data in the manner of multicast transmission, which can save air interface resources.

In a possible implementation manner of the first aspect, if the first request is for the first user equipment to request to obtain the multicast service, that is, the first user equipment is added to the user equipment connected to the network element of the access network The user device that obtains the multicast data. The first preset condition may include: when the first timer expires, the first user equipment still receives the foregoing multicast data, where the first timer is used to determine whether the first user equipment stably receives the multicast data.

It is understandable that after receiving the first request, the core network element starts the first timer. When the first timer is started and the first timer expires, the first user equipment still receives the multicast data. It indicates that the first user equipment is in a state of receiving the multicast data stably, and it can be considered that the first user equipment may not leave the multicast service in a short time. The core network element sends the first information, and the first information may instruct the access network element to transmit the multicast data to the first user equipment in a unicast transmission manner. Alternatively, the first information may also instruct the access network element to transmit multicast data to the first user equipment in a multicast transmission manner, so as to improve the effective utilization of air interface resources on the side of the access network element.

In another possible implementation manner of the first aspect, the core network element is a user plane network element, and before the core network element sends the first information to the access network element serving the first user equipment, the core network element The multicast data may also be sent to the access network element through the first user plane channel, where the first user plane channel is a unicast data transmission channel established by the first user equipment.

Wherein, before the core network element sends the first information to the access network element, the core network element may send the group to the access network element served by the first user equipment in unicast transmission in response to the first request. Broadcast data. In this way, it is possible to ensure timely response to the requirements of the first user equipment, thereby improving user experience.

In another possible implementation manner of the first aspect, the core network element is a user plane network element, and after the core network element sends the first information to the access network element serving the first user equipment, the core network element The multicast data can be sent to the network element of the access network through the second user plane channel. Wherein, the second user plane channel is a unicast data transmission channel established by any user equipment in the multicast group corresponding to the multicast service, or the second user plane channel is established by an access network network element and a user plane network element Multicast data transmission channel.

It is understandable that after the core network element sends the first information to the access network element serving the user equipment, the core network element may send multicast data to the access network element through the second user plane channel. The second user plane channel is not dedicated to the first user equipment. Then, after the access network element receives the multicast data sent by the core network element, it can forward the multicast data to the multicast service of the access network element Each user device in the group. That is, the user plane network element sends multicast data to the access network network element through the second user plane channel, and the access network network element may forward the multicast data to the user equipment in the multicast group according to the first information. In this way, network resources on the user plane network element side can be saved.

In another possible implementation manner of the first aspect, the core network element is a user plane network element. If the core network element sends multicast data to the access network element through the second user plane channel in the manner of multicast transmission, the core network element can stop sending multicast data to the access network element through the first user plane channel data.

That is, the core network element can send multicast data to the access network element through the second user plane channel. In addition, the network element of the access network forwards the multicast data to the user equipment according to the transmission mode indicated in the first information. Therefore, the core network network element transmits multicast data in the manner of multicast transmission, which improves the efficiency of the core network network element to transmit multicast data and saves network resources on the side of the core network network element.

In another possible implementation manner of the first aspect, the foregoing core network element sending multicast data to the access network element through the second user plane channel includes: starting a third timer, and when the third timer expires, The core network element sends multicast data to the access network element through the second user plane channel, where the third timer is used to determine whether the access network element has been configured with air interface resources for multicast data transmission.

It is understandable that because the first user equipment sends the first request to the core network element, the number of user equipments that receive the multicast data among the access network elements serving the first user equipment changes, then the core network element The purpose of sending the first information to the access network element is to indicate that the user equipment of the access network element receiving the multicast data has changed, and the access network element can update the air interface resource. After the core network element sends the first information to the access network element, the third timer is started. When the third timer expires, it can be considered that the access network element has been configured with air interface resources for transmitting multicast data. Therefore, the core network network element sends multicast data to the access network network element through the second user plane channel, and the access network network element transmits the multicast data according to the configured air interface resources.

In another possible implementation manner of the first aspect, the core network element is a session management network element. After the core network element sends the first information to the access network element serving the first user equipment, the core network element may instruct the user plane network element to stop sending multicast to the access network element through the first user plane channel data. The first user plane channel is a unicast data transmission channel established by the first user equipment.

In another possible implementation manner of the first aspect, the core network element is a session management network element. After the core network element sends the first information to the access network element serving the first user equipment, the session management network element may instruct the user plane network element to send multicast data to the access network element through the second user plane channel. Wherein, the second user plane channel is a unicast data transmission channel established by any user equipment in the multicast group corresponding to the multicast service, or the second user plane channel is established by an access network network element and a user plane network element Multicast data transmission channel.

It is understandable that when the core network element is a session management network element, the core network element is a control network element, and the user plane network element is a data transmission network element. The core network element instructs the user plane network element to send multicast data to the access network network element through the second user plane channel, that is to say. The user plane network element only needs to send multicast data through multicast. In this way, the occupancy rate of network resources on the user plane network element side is reduced.

In another possible implementation manner of the first aspect, the core network element is a session management network element. The core network element instructs the user plane network element to send multicast data to the access network element through the second user plane channel, including: when the third timer starts and the third timer expires, the core network element instructs the user plane network element The multicast data is sent to the access network element through the second user plane channel, where the third timer is used to determine whether the access network element has been configured with air interface resources for multicast data transmission.

In another possible implementation manner of the first aspect, the first preset condition may further include: the number of user equipments connected to the network element of the access network in the multicast group meets the second preset condition.

Among them, the multicast group corresponds to the user equipment that obtains the multicast service. The second preset condition may include that the number of user equipment reaches the multicast threshold, or the second preset condition may include that when the number of user equipment reaches the multicast threshold, the core network element starts the fourth timer. When the fourth timer is started until the fourth timer expires and the number of user equipment always reaches the multicast threshold. It is understandable that the number of user equipments always reaches the multicast threshold when the fourth timer is started until the fourth timer expires, and the core network element can determine that the number of user equipments receiving the multicast data corresponding to the multicast service has reached the multicast stably Threshold. Therefore, the fourth timer is used to determine whether the number of user equipment is stable.

In another possible implementation manner of the first aspect, the first request is that the first user equipment requests to obtain multicast data, and the number of user equipment connected to the access network element in the multicast group meets the foregoing second preset Set conditions. Then, the first information used to indicate the manner of transmitting the multicast data may include: the first information is used to instruct the access network element to send the multicast data to the first user equipment in the manner of multicast transmission.

In another possible implementation manner of the first aspect, the first preset condition may further include: the number of user equipments connected to the network element of the access network in the multicast group does not satisfy the second preset condition.

The second preset condition includes that the number of user equipment reaches the multicast threshold, or the second preset condition includes that the fourth timer starts to expire and the number of user equipments always reaches the multicast threshold. Among them, the fourth timer is used to determine whether the number of user equipment is stable.

In another possible implementation manner of the first aspect, if the first request is a first user equipment request to obtain multicast data, and the number of user equipment connected to the access network element in the multicast group does not satisfy the above-mentioned first request, 2. Preset conditions. Then, the first information used to instruct the access network element to transmit the multicast data may include: the first information is used to instruct the access network element to send the multicast data to the first user equipment in a unicast transmission manner.

In another possible implementation manner of the first aspect, in the case where the foregoing first request is a request by the first user equipment to obtain multicast data, the first information may include: identification information of the first user equipment and an identification of the multicast service Information, session connection identification information of the first user equipment and identification information of the multicast service, multicast list information, one or more of the first indication, where the multicast list information may be the user equipment in the multicast group The identification information of the user equipment connected to the access network element in the multicast group, or the session connection identification of the user equipment connected to the access network element in the multicast group. The first instruction is used to instruct to send multicast data to the first user equipment, and the multicast group corresponds to the user equipment that obtains the multicast service.

In another possible implementation manner of the first aspect, the first request is used for the first user equipment to request to leave the multicast service, and the access network element serves the first user equipment before the first user equipment requests to leave the multicast service . Then, the first preset condition includes: the core network element starts the second timer after receiving the first request. When the second timer is started and the second timer expires, the first user equipment still leaves the multicast service. The second timer is used to determine whether the first user equipment stably leaves the multicast service.

In another possible implementation manner of the first aspect, the first preset condition further includes: the number of user equipments connected to the network element of the access network in the multicast group meets the third preset condition. Wherein, the multicast group corresponds to the user equipment that obtains the multicast service, and the third preset condition includes that the number of user equipment is less than the unicast threshold, or includes when the fourth timer is started to the time when the fourth timer expires and the number of user equipment is insufficient. Broadcast threshold. Among them, the fourth timer is used to determine whether the number of user equipment is stable.

In another possible implementation manner of the first aspect, if the first request is that the first user equipment requests to leave the multicast data, and the number of user equipment connected to the access network element in the multicast group meets the third preset Set conditions. Then, the first information used to instruct the access network element to transmit the multicast data may include: the first information is used to instruct the access network element to send the group to the user equipment in the multicast group by unicast transmission. Broadcast data.

In another possible implementation manner of the first aspect, the number of user equipments connected to the network element of the access network in the multicast group does not satisfy the third preset condition. Wherein, the third preset condition includes that the number of user equipments is less than the unicast threshold, or the third preset condition includes that the number of user equipments is less than the unicast threshold, the core network element starts the fourth timer, and when the fourth timer starts to the first The fourth timer expires and the number of user equipments is always less than the unicast threshold, where the fourth timer is used to determine whether the number of user equipments is stable.

In another possible implementation manner of the first aspect, the first request is that the first user equipment requests to leave the multicast data, and the number of user equipment connected to the access network element in the multicast group does not meet the third preset. Set conditions. Then, the first information used to indicate the manner of transmitting the multicast data may include: the first information is used to instruct the access network element to send the multicast data to the first user equipment in the manner of multicast transmission.

In another possible implementation manner of the first aspect, the core network network element is a user plane network element, and the core network network element may send multicast data to the access network network element through the second user plane channel. Wherein, the second user plane channel is a unicast data transmission channel established by any user equipment in the multicast group, or the second user plane channel is a multicast data transmission channel established by an access network element and a core network element .

In another possible implementation manner of the first aspect, the core network element is a session management network element. The core network network element instructs the user plane network element to send multicast data to the access network network element through the second user plane channel. Wherein, the second user plane channel is a unicast data transmission channel established by any user equipment in the multicast group, or the second user plane channel is a multicast data transmission channel established by an access network network element and a user plane network element .

In another possible implementation manner of the first aspect, in the case where the foregoing first request is that the first user equipment requests to leave the multicast data, the first information may include: identification information of the first user equipment and an identification of the multicast service Information, the session connection identification information of the first user equipment and the identification information of the multicast service, multicast list information, one or more of the second indication, where the multicast list information may be the user equipment in the multicast group The identification information of the user equipment connected to the access network element in the multicast group, or the session connection identification of the user equipment connected to the access network element in the multicast group, the second indication is used to indicate that no Then send the multicast data to the first user equipment. The multicast group corresponds to the user equipment that obtains the multicast service.

In another possible implementation manner of the first aspect, the core network element receives second information from the access network element, and the second information is used to indicate that the access network element has configured air interface resources for multicast data transmission; The core network element sends the multicast data to the access network element through the second user plane channel according to the second information.

In another possible implementation manner of the first aspect, the core network element is a session management network element. The foregoing core network element sends multicast data to the access network element through the second user plane channel according to the second information, including the core network element instructing the user plane network element to send multicast data to the access network element through the second user plane channel according to the second information The network element of the access network sends the multicast data.

In another possible implementation manner of the first aspect, when the core network element is a user plane network element, the core network element sends the first information to the access network element serving the first user equipment, including: the core The network network element sends the first information to the access network network element through the session management network element and the mobility management network element.

In another possible implementation manner of the first aspect, the core network network element is a unicast user plane network element and a multicast user plane network element, and the multicast user plane network element is used to transmit multicast data in a multicast manner.

In another possible implementation manner of the first aspect, when the core network element is a session management network element, the core network element sends the first information to the access network element serving the first user equipment, including: the core network The network element sends the first information to the access network network element through the mobility management network element.

In another possible implementation manner of the first aspect, the core network element is a unicast session management network element and a multicast session management network element, and the multicast session management network element is used to manage a multicast group, and the multicast group corresponds to User equipment for obtaining multicast services.

In another possible implementation manner of the first aspect, the core network element is a user plane network element, and the method further includes: the user plane network element receives a preset multicast threshold from the session management network element, and the user plane network element Receive the preset unicast threshold from the session management network element.

In a second aspect, an embodiment of the present application also provides a method for transmitting a multicast service. The method may include: a core network element receives a first request, and the first request is used by the first user equipment to request the multicast service. When the first preset condition is met, the core network element sends first information to the access network element serving the first user equipment, where the first information is used to instruct to send multicast data corresponding to the multicast service to the first user equipment .

It is understandable that the first information is used to instruct the access network element to send multicast data to the first user equipment, and the first information does not indicate a transmission mode for the access network element to transmit the multicast data. The first information may indicate that the network element of the access network sends multicast data to the first user equipment, and the network element of the access network may determine, according to the first information, the transmission mode of the multicast data to be multicast transmission or unicast transmission.

In a possible implementation manner of the second aspect, the first preset condition may include: when the first timer is started and the first timer expires, the first user equipment still receives the multicast data. The first timer is used to determine whether the first user equipment stably receives multicast data.

In another possible implementation manner of the second aspect, the access network element determines that the number of user equipment connected to the access network element in the multicast group satisfies the second preset condition according to the above-mentioned first information. Wherein, the multicast group corresponds to the user equipment that obtains the multicast service, and the second preset condition may include that the number of user equipment reaches the multicast threshold, or the second preset condition may include starting the fourth timer to the fourth timer Timeout, and the number of user devices always reaches the multicast threshold. Among them, the fourth timer can be used to determine whether the number of user equipment is stable.

In another possible implementation manner of the second aspect, if the number of user equipments connected to the network element of the access network in the multicast group meets the second preset condition. The network element of the access network may send the above-mentioned multicast data to the user equipment in the multicast group in the manner of multicast transmission.

In another possible implementation manner of the second aspect, the core network element is a user plane network element. Before the aforementioned core network element sends the first information to the access network element serving the first user equipment, the core network element may also send multicast data to the access network element through the first user plane channel. The first user plane channel is a unicast data transmission channel established by the first user equipment.

In another possible implementation manner of the second aspect, the foregoing core network network element is a user plane network element. After the foregoing core network element sends the first information to the access network element serving the first user equipment, the core network element may also send multicast data to the access network element through the second user plane channel. Wherein, the second user plane channel is a unicast data transmission channel established by any user equipment in the multicast group corresponding to the multicast service, or the second user plane channel is established by an access network element and a core network element The multicast data transmission channel, and the multicast group corresponds to the user equipment that obtains the multicast service.

In another possible implementation manner of the second aspect, after the above-mentioned core network element sends the first information to the access network element serving the first user equipment, a third timer may be started. When the third timer expires, the core network element sends multicast data to the access network element through the second user plane channel. The third timer may be used to determine whether the network element of the access network has been configured with air interface resources for multicast data transmission.

In another possible implementation manner of the second aspect, the core network element receives second information from the access network element, and the second information is used to indicate that the access network element has configured air interface resources for multicast data transmission; The core network element sends the multicast data to the access network element through the second user plane channel according to the second information.

It can be understood that the network element of the access network configures the air interface resource for transmitting the multicast data according to the first information. Among them, if the access network element transmits multicast data in the manner of multicast transmission, the air interface resources of the multicast data may be configured in the manner of multicast transmission. If the network element of the access network transmits the multicast data in the unicast transmission mode, the air interface resources of the multicast data can be configured in the unicast transmission mode.

In another possible implementation manner of the second aspect, the foregoing core network network element is a user plane network element. After the core network element sends the first information to the access network element serving the first user equipment, the core network element may stop sending multicast data to the access network element through the first user plane channel. In other words, since the core network element sends multicast data to the access network element through the first user plane channel, the core network element sends the data of the first user equipment to the access network element by unicast transmission. Multicast data. After the access network element receives the first information, the core network element will stop sending multicast data to the access network element through the first user plane channel, so that the access network element decides to transmit the group to the first user equipment The transmission method of broadcast data.

In another possible implementation manner of the second aspect, the core network element is a session management network element. After the core network element sends the first information to the access network element serving the first user equipment, the core network element may instruct the user plane network element to send multicast data to the access network element through the first user plane channel. The first user plane channel is a unicast data transmission channel established by the first user equipment.

In another possible implementation manner of the second aspect, the core network element is a session management network element. The foregoing core network element may also instruct the user plane network element to send the foregoing multicast data to the access network element through the second user plane channel. Wherein, the second user plane channel is a unicast data transmission channel established by any user equipment in the multicast group corresponding to the multicast service, or the second user plane channel is established by an access network network element and a user plane network element Transmission channel of multicast data.

In another possible implementation manner of the second aspect, the foregoing core network element may further instruct the user plane network element to send the foregoing multicast data to the access network element through the second user plane channel, which may include: starting a third timing When the third timer expires, the core network element may instruct the user plane network element to send the foregoing multicast data to the access network network element through the second user plane channel. The third timer may be used to determine whether the network element of the access network has been configured with air interface resources for multicast data transmission.

In another possible implementation manner of the second aspect, the foregoing core network element may also receive second information from the access network element, and the second information may be used to indicate that the access network element has configured the foregoing multicast data Air interface resources for transmission. The core network network element may instruct the user plane network element according to the second information to send the foregoing multicast data to the access network network element through the second user channel.

In another possible implementation manner of the second aspect, after the above-mentioned core network element sends the first information to the access network element serving the first user equipment, the core network element may instruct the user plane network element to stop passing through the first user equipment. A user plane channel sends multicast data to the network element of the access network.

In another possible implementation manner of the second aspect, the foregoing first information may include one or more of: the identification of the first user equipment, the identification information of the multicast service, the multicast list information, and the first indication. Wherein, the multicast list information may be the identification information of the user equipment in the multicast group or the identification information of the user equipment connected to the access network element in the multicast group, and the first indication is used to indicate to the first user equipment The multicast data is sent, and the multicast group corresponds to the user equipment that obtains the multicast service.

In another possible implementation manner of the second aspect, the core network element is a unicast user plane network element or a multicast user plane network element, and the multicast user plane network element is used to transmit multicast data in a multicast manner.

In another possible implementation manner of the second aspect, when the core network element is a session management network element, the core network element sends the first information to the access network element serving the first user equipment, including: the core network The network element sends the first information to the access network network element through the mobility management network element.

In another possible implementation manner of the second aspect, the core network element is a unicast session management network element and a multicast session management network element, and the multicast session management network element is used to manage the multicast group, and the multicast group corresponds to User equipment for obtaining multicast services.

In another possible implementation manner of the second aspect, the core network element is a user plane network element, and the above method further includes: the user plane network element receives a preset first timer time limit from the session management network element.

In a third aspect, the present application also provides a method for transmitting a multicast service. The method may include: the core network element receives a first request, the first request is used by the first user equipment to request to leave the multicast service; When conditions are set, the core network element requests the first user equipment to send the first information to the access network element that serves the first user equipment before leaving the multicast service, and the first information is used to indicate that it will no longer send to the first user equipment Multicast data corresponding to the multicast service.

In a possible implementation manner of the third aspect, the first preset condition includes: after the core network element receives the first request, it starts a second timer, and when the second timer starts to the second timer expires, the first The user equipment still leaves the multicast service, where the second timer is used to determine whether the first user equipment stably leaves the multicast service.

In another possible implementation manner of the third aspect, the foregoing core network network element may be a user plane network element. The core network element may also send multicast data to the access network element through the second user plane channel. Wherein, the second user plane channel is a unicast data transmission channel established by any user equipment in the multicast group corresponding to the multicast service, or the second user plane channel is established by an access network network element and a user plane network element Transmission channel of multicast data.

In another possible implementation manner of the third aspect, the core network element may also receive second information from the access network element, and the second information may be used to indicate that the access network element has been configured for multicast data transmission Air interface resources. The core network element may send multicast data to the access network element through the second user plane channel according to the second information.

In another possible implementation manner of the third aspect, the aforementioned core network element may be a session management network element. The core network element may also instruct the user plane network element to send the foregoing multicast data to the access network element through the second user plane channel. Wherein, the second user plane channel is a unicast data transmission channel established by any user equipment in the multicast group corresponding to the multicast service, or the second user plane channel is established by an access network network element and a user plane network element Transmission channel of multicast data.

In another possible implementation manner of the third aspect, the core network element may also receive second information from the access network element, and the second information may be used to indicate that the access network element has been configured for multicast data transmission Air interface resources. The core network element may, according to the second information, instruct the user plane network element to send the multicast data to the access network element through the second user plane channel.

In another possible implementation manner of the third aspect, the above-mentioned first information may include one or more of: the identification of the first user equipment, the identification information of the multicast service, the multicast list information, and the second indication. Wherein, the multicast list information may be the identification information of the user equipment in the multicast group or the identification information of the user equipment connected to the access network element in the multicast group, and the second indication is used to indicate that the first The user equipment sends multicast data, and the multicast group corresponds to the user equipment that obtains the multicast service.

In another possible implementation manner of the third aspect, the core network network element is a unicast user plane network element or a multicast user plane network element, and the multicast user plane network element is used to transmit multicast data in a multicast manner.

In another possible implementation manner of the third aspect, when the core network element is a session management network element, the core network element sends the first information to the access network element serving the first user equipment, including: the core network The network element sends the first information to the access network network element through the mobility management network element.

In another possible implementation manner of the third aspect, the core network element is a unicast session management network element and a multicast session management network element, and the multicast session management network element is used to manage the multicast group, and the multicast group corresponds to User equipment for obtaining multicast services.

In another possible implementation manner of the third aspect, the core network element is a user plane network element, and the above method further includes: the user plane network element receives a preset second timer time limit from the session management network element.

In a fourth aspect, this application also provides a method for transmitting multicast services, and the method may include:

The access network element can receive the first information from the core network element. According to the first information, the network element of the access network may determine the transmission mode for sending the multicast data to the user equipment in the multicast group. The access network element sends the multicast data to the user equipment in the multicast group in a determined transmission mode, where the determined transmission mode includes unicast transmission or multicast transmission.

In a possible implementation manner of the fourth aspect, the foregoing first information may include identification information of the first user equipment or session connection identification information of the first user equipment. Wherein, the first user equipment is a user equipment requesting to obtain a multicast service, the multicast service corresponds to multicast data, and the access network element serves the first user equipment.

In another possible implementation manner of the fourth aspect, before the access network element receives the first information from the core network element, the access network element may also receive multicast data through the first user plane channel, where the first user plane channel A user plane channel is a unicast data transmission channel established by the first user equipment. In addition, the network element of the access network forwards the multicast data to the first user equipment in a unicast transmission manner.

In another possible implementation manner of the fourth aspect, after the access network element receives the first information from the core network element, the access network element may also forward the group from the second user plane channel to the first user equipment. The second user plane channel is a unicast data transmission channel established by any user equipment in the multicast group, or the second user plane channel is the second user plane channel is the access network element and the first The multicast data transmission channel established by the core network element.

In another possible implementation manner of the fourth aspect, after receiving the first information from the core network element, the access network element starts the first timer, and before the first timer expires, the access network element starts the single The multicast transmission mode sends the multicast data to the first user equipment. After the first timer expires, and the first user equipment still receives the multicast data, the access network element sends the multicast data to the first user equipment in the manner of multicast transmission.

In another possible implementation manner of the fourth aspect, the above-mentioned access network element determines the transmission mode for sending multicast data to the user equipment in the multicast group according to the first information, including: the access network element determines to The multicast data is sent to the first user equipment in a multicast transmission manner.

In another possible implementation manner of the fourth aspect, the above-mentioned access network element determining to send multicast data to the first user equipment in a multicast transmission manner includes: a multicast group connected to the access network element When the number of user equipment meets the second preset condition, the access network element determines to send the multicast data to the first user equipment in a multicast transmission manner. Wherein, the second preset condition may include: the number of user equipment reaches the multicast threshold, or the second preset condition includes when the fourth timer starts to expire and the number of user equipment always reaches the multicast threshold, Among them, the fourth timer is used to determine whether the number of user equipment is stable.

In another possible implementation manner of the fourth aspect, if the number of user equipment does not meet the foregoing second preset condition, the access network element may determine to send the multicast data to the first user equipment in a unicast transmission manner. Wherein, the second preset condition may include: the number of user equipment reaches the multicast threshold, or the second preset condition may include when the fourth timer starts to expire and the number of user equipment always reaches the multicast threshold. Among them, the fourth timer is used to determine whether the number of user equipment is stable.

In another possible implementation manner of the fourth aspect, the first information may further include: device identification information of the first user and identification information of the multicast service, session connection identification information of the first user equipment and identification of the multicast service Information, multicast list information, and the first indication, where the multicast list information may be the identification information of the user equipment in the multicast group, the identification information of the user equipment connected to the access network element in the multicast group, or One or more of the session connection identifiers of the user equipment connected to the access network element in the multicast group, the first indication is used to indicate to send multicast data to the first user equipment, and the multicast group corresponds to the acquisition group User equipment for broadcasting services.

In another possible implementation manner of the fourth aspect, the foregoing first information may include identification information of the first user equipment, and the first user equipment is a user equipment requesting to leave the multicast data corresponding to the multicast service. Wherein, the access network element serves the first user equipment before the first user equipment requests to leave the multicast service.

In another possible implementation manner of the fourth aspect, the above-mentioned access network element determines the transmission mode for sending multicast data to the user equipment in the multicast group according to the first information, including: the access network element determines to The unicast transmission mode sends multicast data to the user equipment in the multicast group, where the user equipment in the multicast group does not include the first user equipment.

In another possible implementation manner of the fourth aspect, the above-mentioned access network element determines to send multicast data to the user equipment in the multicast group by means of unicast transmission, including: the multicast group and the access network When the number of user equipments connected to the network element meets the second preset condition, the network element of the access network determines to send the multicast data to the user equipment in the multicast group by means of unicast transmission. Wherein, the second preset condition includes: the number of user equipments is less than the unicast threshold, or the second preset condition includes that when the number of user equipments is less than the unicast threshold, the fourth timer is started, and when the fourth timer is started to the fourth timing The timer times out and the number of user equipments is always less than the unicast threshold, where the fourth timer is used to determine whether the number of user equipments is stable.

In another possible implementation manner of the fourth aspect, if the number of user equipment does not meet the above second preset condition, the access network element determines to send multicast data to the user equipment in the multicast group by means of multicast transmission . Wherein, the second preset condition includes: the number of user equipments is less than the unicast threshold, or the second preset condition includes that the fourth timer is started until the fourth timer expires and the number of user equipments is always less than the unicast threshold, where the fourth The timer is used to determine whether the number of user equipment is stable.

In another possible implementation manner of the fourth aspect, the foregoing first information may further include: identification information of the first user equipment and identification information of the multicast service, session connection identification information of the first user equipment and identification of the multicast service One or more of information, multicast list information, and second indication.

Wherein, the multicast list information may be the identification information of the user equipment in the multicast group, the identification information of the user equipment connected to the access network element in the multicast group, or the identification information of the user equipment connected to the access network element in the multicast group. One or more of the session connection identifiers of the connected user equipment, and the second indication is used to indicate that no multicast data is sent to the first user equipment.

In another possible implementation manner of the fourth aspect, the above-mentioned access network element may feed back the determined transmission mode to the core network element.

In another possible implementation manner of the fourth aspect, the foregoing core network network element includes: a user plane network element, a session management network element, or a mobility management network element.

In the fifth aspect, this application also provides a core network network element, and the core network network element may be a user plane network element. The core network element may include a receiving unit, a sending unit, and a processing unit. The receiving unit, the sending unit, and the processing unit are used to implement the first aspect and any possible implementation manner thereof, the second aspect and any one of the implementation manners thereof , The third aspect and any of its possible implementation manners, and the fourth aspect and any of its possible implementation manners, the multicast service transmission method.

In the sixth aspect, this application also provides a core network network element, and the core network network element may be a user plane network element. The core network element may include: a memory for storing computer program code, the computer program code including instructions; a radio frequency circuit for transmitting and receiving wireless signals; a processor for executing the above instructions to make the core network element Implementation of the first aspect and any of its possible implementations, the second aspect and any of its implementations, the third aspect and any of its possible implementations, and the fourth aspect and any of its possible implementations The transmission method of the multicast service in the mode.

In a seventh aspect, this application also provides an access network network element, which may include a receiving unit, a sending unit, and a processing unit. The receiving unit, the sending unit, and the processing unit are used to implement the first aspect and its Any possible implementation, the second aspect and any one of its implementations, the third aspect and any of its possible implementations, and the fourth aspect and any of its possible implementations, multicast services Transmission method.

In an eighth aspect, the present application also provides an access network element, which may include: a memory for storing computer program codes, the computer program codes including instructions; and a radio frequency circuit for transmitting wireless signals And receiving; a processor, configured to execute the foregoing instructions, so that the access network element executes the first aspect and any of its possible implementation manners, the second aspect and any of its implementation manners, the third aspect and any of its implementations A possible implementation manner and a multicast service transmission method in the fourth aspect and any one of the possible implementation manners thereof.

In a ninth aspect, this application also provides a core network network element, which may be a session management network element or a mobility management network element. The core network element may include a receiving unit, a sending unit, and a processing unit. The receiving unit, the sending unit, and the processing unit are used to implement the first aspect and any of its possible implementations, and the second aspect and any of its implementations. And the third aspect and any one of its possible implementation manners for the transmission method of the multicast service.

In a tenth aspect, this application also provides a core network element, which may be a session management network element or a mobility management network element. The core network element may include a memory for storing computer program codes, and the computer program code includes instructions; a radio frequency circuit for transmitting and receiving wireless signals; and a processor for executing the above instructions so that the core network element can execute The first aspect and any of its possible implementations, the second aspect and any of its implementations, the third aspect and any of its possible implementations, and the fourth aspect and any of its possible implementations The transmission method of the multicast service in the.

In an eleventh aspect, the present application also provides a chip system, which includes a processor and a memory, and instructions are stored in the memory; when the instructions are executed by the processor, the first aspect, the second aspect, The transmission method of the multicast service in any possible implementation manner of the third aspect or the fourth aspect. The chip system can be composed of chips, and can also include chips and other discrete devices.

In a twelfth aspect, a computer-readable storage medium is provided. The computer-readable storage medium stores computer-executable instructions. When the computer-executable instructions are executed by a processor, they can implement the first aspect, the second aspect, the third aspect, or the In the fourth aspect, a multicast service transmission method in any possible implementation manner.

In a thirteenth aspect, a computer program product is provided, and a computer program product is provided, which when running on a computer, enables any possible realization of the first aspect, the second aspect, the third aspect, or the fourth aspect The transmission method of the multicast service in the mode. For example, the computer may be at least one storage node.

In a fourteenth aspect, the present application also provides a communication system, which includes the user plane network element mentioned in the fifth aspect and a session management network element communicating with the user plane network element.

In a fifteenth aspect, the present application also provides a communication system, which includes the session management network element mentioned in the seventh aspect and a user plane network element communicating with the session management network element.

Description of the drawings

FIG. 1 is a schematic diagram of the structure of an IPTV system provided by an embodiment of the application;

FIG. 2 is a flowchart of a user equipment obtaining IPTV multicast data according to an embodiment of the application;

3A is a schematic diagram of a network architecture of a 5G core network of a method for transmitting a multicast service according to an embodiment of the application;

3B is a schematic diagram of a network architecture of a 5G core network of another multicast service transmission method provided by an embodiment of the application;

FIG. 3C is a schematic structural diagram of a user equipment provided by an embodiment of this application;

FIG. 4A is a flowchart of a method for transmitting a multicast service according to an embodiment of the application;

4B is a flowchart of another multicast service transmission method provided by an embodiment of the application;

4C is a flowchart of a method for transmitting a multicast service according to an embodiment of the application;

4D is a flowchart of another multicast service transmission method provided by an embodiment of the application;

FIG. 5A is a flowchart of another multicast service transmission method provided by an embodiment of the application;

FIG. 5B is a flowchart of another method for transmitting a multicast service according to an embodiment of the application;

FIG. 6A is a flowchart of another multicast service transmission method provided by an embodiment of this application;

FIG. 6B is a flowchart of another method for transmitting a multicast service according to an embodiment of the application;

FIG. 6C is a flowchart of another multicast service transmission method provided by an embodiment of the application;

FIG. 6D is a flowchart of another multicast service transmission method provided by an embodiment of the application;

FIG. 7 is a schematic structural diagram of a UPF network element provided by an embodiment of this application;

FIG. 8 is a schematic structural diagram of an SMF network element provided by an embodiment of this application;

FIG. 9 is a schematic structural diagram of a RAN network element provided by an embodiment of this application.

Detailed ways

Hereinafter, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present embodiment, unless otherwise specified, "plurality" means two or more.

For ease of understanding, FIG. 2 shows a schematic flow diagram of the IPTV data network transmitting IPTV multicast data to the STB (ie, user equipment) in the IPTV system shown in FIG. 1 in the conventional technology. As shown in FIG. 2, the process of transmitting IPTV multicast data from the IPTV data network to the STB (ie, user equipment) may include steps 201 to 206.

Step 201: The STB sends a service request to the 5G-RG.

Take, for example, that the service request in the IPTV system is to broadcast service data of a certain channel. Among them, if the STB receives a user's switching operation on a certain channel, the STB can send a service request to the 5G-RG. For example, if the STB receives the user's operation on the channel switching button of the TV remote control, the STB sends a service request to the 5G-RG.

Exemplarily, the above service request may be a request to play the service data of the channel, or the service request may be a request to stop receiving the service data of the channel. Among them, if the user equipment requests to stop receiving service data of a certain channel, the service request is the multicast service of the user equipment requesting to leave the channel; if the user equipment requests to obtain the service data of a certain channel, the service request is the user equipment requesting to obtain the channel Multicast business.

In one case, the service request may be a network group management protocol (Internet Group Management Protocol, IGMP)/Multicast Listener Discovery (Multicast Listener Discovery, MLD) request to join a channel. The service request is used to request the IPTV data network to broadcast multicast data of a certain channel.

In another case, the service request may also be an IGMP/MLD leave channel request. The service request is used to request the IPTV data network to stop playing data of a certain channel.

Among them, after a user equipment (such as an STB) goes online, a 5G-RG corresponding to the user equipment can establish a protocol data unit (protocol data unit, PDU) session channel. The PDU session channel establishes a session connection between the 5G-RG and the UPF. The 5G-RG can send a service request to the RAN through the PDU session, and the RAN forwards the service request of the user equipment to the UPF. In response to the service request, the UPF sends multicast data to the 5G-RG corresponding to the user equipment through the PDU session channel corresponding to the user equipment. In other words, before the 5G-RG receives the service request from the STB, the user's PDU session channel has been created.

In this way, the STB can send a service request to the 5G-RG through the PDU session channel.

Step 202: The 5G-RG sends a service request to the UPF through the RAN.

The service request is information that the user equipment requests to join the channel, or the service request is the information that the user equipment requests to leave the channel.

It should be noted that the 5G-RG can send the service request from the STB to the RAN, and the RAN sends the aforementioned service request to the UPF.

Step 203: The UPF responds to the service request and determines the multicast authority of the STB according to the multicast access control information.

Understandably, the STB is the user equipment in the system. For example, in an actual scenario, the TV can play multicast data. The STB is connected to the TV, and the STB is used to receive control information triggered by the user. Such as receiving the control information of a new channel, or leaving the current channel control information.

Specifically, the UPF checks in the multicast access control information whether the user ID corresponding to the user equipment has the authority to receive the multicast data of the channel. If the user ID has the authority to receive the multicast data of the channel, UPF can add the ID corresponding to the user's PDU session channel to the multicast list of the channel; if the user ID does not have the authority to receive the multicast data of the channel, UPF will Refuse to add the identifier corresponding to the user's PDU session channel to the multicast list of the channel. The user identifier corresponding to the user equipment is the identifier of the 5G-RG connected to the STB. In other words, when the UPF determines whether the user equipment has the authority to receive the multicast data of the channel, it will determine the identity of the 5G-RG connected to the STB, and determine whether the user equipment has the authority to receive the channel according to the authority of the 5G-RG identity Multicast data.

In some embodiments, if a request reporting function is set in the UPF, once the UPF receives the service request, it can report the service request to the Session Management Function (SMF) network element. If the request reporting function is also set on the SMF, once the SMF receives the service request, it can report the service request to the Policy Control Function (PCF) network element. Steps 203a and 203b are as follows.

Step 203a: The UPF sends the report event of the service request to the SMF.

Step 203b: The SMF sends the report event of the service request to the PCF.

It is understandable that if both the UPF and SMF of the system are configured to request reporting, then step 203a and step 203b can be performed after the above step 203. If there is no report request set in the system, step 204 and step 205 can be directly executed after step 203.

Step 204: The IPTV data network sends multicast data to the UPF.

It is understandable that the IPTV data network sends multicast data to the UPF in the manner of multicast transmission.

Step 205: UPF copies the multicast data of the channel in multiple copies according to the number of PDU session channels in the multicast list of the channel.

Among them, the number of PDU session channels in the multicast list of the channel is as much as the multicast data of the channel copied by the UPF. In other words, how many PDU session channels are in the multicast list of the channel, and how many copies of the multicast data of the channel need to be copied by the PDU. Or, the multicast data of the channel copied by UPF is 1 less than the number of PDU session channels in the multicast list of the channel, that is, after UPF receives the multicast data from the IPTV data network, it copies the multicast data so that the UPF replicates The number of copies of the multicast data plus one copy of the multicast data received from the IPTV data network is equal to the number of PDU session channels in the multicast list of the channel.

Step 206: The UPF sends the multicast data of the channel to the RAN corresponding to the 5G-RG in the manner of unicast transmission through the PDU session in the multicast list.

It is understandable that 5G-RG can forward the multicast data of the channel to the STB. In the foregoing implementation manner, regardless of the number of PDU session channels included in the multicast list of the channel in the UPF, the UPF sends the multicast data of the channel to the 5G-RG in a unicast manner. In the IPTV system, the transmission mode of the multicast data of the UPF transmission channel cannot be adjusted according to the number of PDU session channels (that is, the number of user equipment).

It is worth mentioning that in the 4th generation mobile communication technology (4G), the on-demand operation technology of the multimedia broadcast multicast service (multimedia broadcast multicast service, MBMS) can be used to realize multicast reception based on The number of data devices is the function of unicast or multicast transmission switching. The realization of this technology relies on adding servers (or network elements) in the system, and the number of users receiving the same multicast data is determined through the added servers. Specifically, the added server can determine the number of users receiving the same multicast data by using deep packet inspection (DPI) technology, or by establishing a connection between the server and the user. In this way, the multicast data transmission mode can be adjusted according to the number of users of the same multicast data determined by the server. For example, when the number of users receiving the same multicast data exceeds a preset threshold, the transmission mode of multicast transmission is adopted. When the number of users receiving the same multicast data is less than the preset threshold, the transmission mode of unicast transmission is adopted.

If the on-demand MBMS technology is directly applied to the IPTV system, a server or network element needs to be added to the IPTV system. Doing so will change the layout of the existing IPTV system and increase the cost.

In addition, even to change the existing IPTV network deployment. Taking the 5G core network to transmit multicast data as an example, the UPF in the 5G core network sends data to the RAN in unicast mode, and the RAN sends multicast data to the STB in unicast mode. In other words, in the 5G core network, both UPF and RAN can be set as MBMS operating on demand. The adjustment to the framework of the existing 5G core network is relatively large, the implementation is difficult, and the cost is high.

The embodiment of the application provides a method for transmitting IPTV services in a 5G core network. Taking the transmission of multicast data in the 5G core network as an example, the purpose of adjusting the transmission mode of UPF or RAN in the 5G core network can be achieved without changing the existing IPTV system. Specifically, the transmission modes of UPF and RAN in the 5G core network can be adjusted. Among them, a multicast threshold or a unicast threshold is set in the core network element that transmits IPTV data, so that the core network element can make a transmission decision based on the multicast threshold or the unicast threshold. The transmission decision can indicate the transmission mode of the air interface, that is, the transmission decision can control the transmission mode of the RAN. In addition, in order to reduce the occupation of resources on the network side, the UPF can send multicast data to the RAN through multicast transmission.

For example, the STB can send a service request to the RAN through 5G-RG, and the RAN can forward the service request of the STB to the UPF. Therefore, the UPF can determine the number of user equipment served by the RAN according to the service request forwarded by the RAN. When the UPF determines that among the user equipments served by the RAN, there are more user equipments that receive the same multicast data (for example, the multicast threshold is reached), the UPF can make a transmission decision for RAN multicast transmission. When the UPF determines that among the user equipments served by the RAN, there are fewer user equipments receiving the same multicast data (for example, less than the unicast threshold), the UPF can make a transmission decision for RAN unicast transmission.

It is worth mentioning that in the description of the embodiments of the present application, the terms "multicast", "multicast", "group communication" and other related terms can be interchanged.

The multicast service transmission method provided by the embodiment of the present application may be applicable to the network service architecture already deployed by the operator. For example, based on the IPTV network service architecture already deployed by the operator, or based on the network service architecture of the New Radio (NR) network of the fifth-generation (5th-Generation, 5G) mobile communication system deployed by the operator, or, Network service architecture based on the 4th-Generation (4G) mobile communication system Long Term Evolution (LTE) network. It can also be applied to other network service architectures, for example, other mobile communication systems developed after the fifth generation, which is not limited in the embodiment of the present application.

Please refer to FIG. 3A and FIG. 3B, which are the network service architectures of the 5G core network to which the multicast service transmission method according to the embodiment of the present application is applied. As shown in Figure 3A, the 5G core network includes STB, 5G-RG, RAN, Access and Mobility Management Function (AMF) network elements, UPF and SMF. As shown in FIG. 3B, the 5G core network includes M-SMF, U-SMF, M-UPF, and U-UPF.

RAN: It can be a base station, such as a macro base station and a micro base station. RAN is mainly responsible for radio resource management, service quality management, data compression and encryption on the air interface side. In an IPTV network, RAN is a data transmission network element.

UPF: Mainly responsible for packet routing and forwarding, and quality of service (QoS) processing of user plane data, etc. UPF can receive multicast data from the IPTV data network, and then transmit the multicast data to the RAN serving the user equipment through the session channel. Among them, the M-UPF network element is used for data forwarding of multicast transmission; the U-UPF network element is used for data forwarding of unicast transmission.

AMF: Mainly responsible for the processing of control plane messages, such as: access control, mobility management, lawful interception, access authentication/authorization, etc.

SMF: Mainly used for session management, UE's Internet Protocol (IP) address allocation and management, selection of end points that can manage user plane functions, policy control and charging function interfaces, downlink data notifications, etc. Among them, the M-SMF network element is used for session management of multicast transmission; U-SMF is used for session management of unicast transmission.

In the network service architecture of the 5G core network shown in FIG. 3A and FIG. 3B, AMF and SMF are control network elements, and AMF and SMF can transmit control information (eg, first information). RAN and UPF are data network elements, which are mainly used to transmit multicast data. The first information may include unicast transmission or multicast transmission; the first information may also be a multicast threshold and/or a unicast threshold; the first information may also be the number of user equipments that receive multicast data. If the first information includes multicast transmission, the SMF sends the first information to the RAN through AMF. The RAN can send multicast data corresponding to the multicast service in the manner of multicast transmission.

Example 1: The control information sent by the SMF to the UPF may include the multicast threshold. The UPF receives the control information sent by the SMF, and the UPF determines that the number of user equipments corresponding to a multicast service exceeds the multicast threshold, and then sends the multicast data to the RAN by means of multicast transmission. The control information sent by the SMF to the UPF may include the unicast threshold. When the UPF receives the control information sent by the SMF, the UPF determines that the number of user equipment receiving a multicast service is less than the unicast threshold, and then sends the multicast to the RAN by unicast transmission. data.

Example 2: SMF sends control information to RAN through AMF. If the control information received by the RAN is related information such as the number of user equipments receiving multicast data or a multicast list. Wherein, the multicast list may include PDU session list information for receiving the multicast data. In this way, the RAN can calculate the number of user equipments that receive the multicast data according to the PDU session list information. The RAN can configure air interface resources for the 5G-RG corresponding to the user equipment according to related information such as the number of user equipment receiving the multicast data or the multicast list. Therefore, the RAN can decide to transmit multicast data to the 5G-RG in the form of unicast transmission or multicast transmission. If the RAN decides to perform unicast transmission, the RAN needs to allocate air interface resources for unicast transmission to each 5G-RG, and send multicast data to the 5G-RG through the corresponding air interface resources. If the RAN decides to multicast transmission, the RAN needs to allocate air interface resources for multicast transmission to send multicast data for multiple 5G-RGs. It can be understood that if the RAN receives the control decision information from the SMF as unicast transmission, the RAN uses unicast transmission to send the multicast data. If the RAN receives the control information from the SMF for multicast transmission, the RAN uses multicast transmission to send the multicast data. It should be understood that if the control decision information received from the SMF by the RAN is unicast transmission or multicast transmission, the RAN still needs to set corresponding air interface transmission resources for each 5G-RG according to the transmission mode of the multicast data. In some embodiments, if the control decision information received by the RAN is unicast transmission or multicast transmission, and the RAN cannot complete the air interface resource configuration for response transmission, the RAN can reject the control decision information of unicast transmission or multicast transmission from SMF. .

Among them, the foregoing description is only a brief introduction to the functions of each network element in the network architecture of the 5G core network shown in FIG. 3A and FIG. 3B. The functions of each network element can be adjusted according to actual usage scenarios, which are not specifically limited in the embodiment of the present application. Regarding the functions and working principles of each network element in the network service architecture of the 5G core network shown in FIG. 3A and FIG. 3B, reference may be made to the related description in the conventional technology, which will not be repeated here.

In the embodiments of the present application, the user equipment may be a mobile phone (mobile phone), various forms of user equipment (UE), terminal device (terminal device), set-top box, television, netbook, tablet computer, etc. Or, the user equipment can also be other desktop devices, laptop devices, handheld devices, wearable devices, smart home devices, and vehicle-mounted devices with radio communication functions, such as Ultra-mobile Personal Computers (Ultra-mobile Personal Computer). , UMPC), smart cameras, netbooks, personal digital assistants (Personal Digital Assistant, PDA), portable multimedia players (Portable Multimedia Player, PMP), etc. The embodiment of the present application does not limit the specific type and structure of the user equipment.

It should be noted that when the user equipment is a mobile phone, various forms of user equipment, terminal equipment and other user equipment with radio communication functions, the user equipment may send a service request (such as the first request) to the RAN. That is to say, in the network architecture diagrams of the 5G core network in Figures 3A and 3B, if the user equipment is a mobile phone, various forms of user equipment, terminal equipment and other user equipment with radio communication functions, 5G can be omitted. -RG. In the same way, when the user equipment is a user equipment that can send to the RAN, such as a notebook or a tablet computer, the 5G-RG can be omitted in the network architecture diagrams of the 5G core network in FIG. 3A and FIG. 3B.

Please refer to FIG. 3C, which shows a schematic diagram of a hardware result of a user equipment provided by an embodiment of the present application. As shown in FIG. 3C, the user equipment 300 may include a processor 301, a communication line 302, a memory 303, and at least one communication interface (in FIG. 3C, the communication interface 304 is included as an example for illustration).

The processor 301 may be a general-purpose central processing unit (central processing unit, CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more programs for controlling the execution of the program of this application. integrated circuit.

The communication line 302 may include a path to transmit information between the aforementioned components.

The communication interface 304 uses any device such as a transceiver to communicate with other devices or communication networks, such as Ethernet, wireless access network RAN, wireless local area networks (WLAN), and so on.

The memory 303 may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, random access memory (RAM), or other types that can store information and instructions The dynamic storage device can also be electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disk storage, optical disc storage (Including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or can be used to carry or store desired program codes in the form of instructions or data structures and can be used by a computer Any other media accessed, but not limited to this. The memory may exist independently, and is connected to the processor through the communication line 302. The memory can also be integrated with the processor.

Wherein, the memory 303 is used to store computer-executable instructions for executing the solution of the present application, where the memory 303 can store the instructions, and the processor 301 controls the execution. The processor 301 is configured to execute computer execution instructions stored in the memory 303, so as to realize the reception of multicast data. The memory 303 shown in FIG. 3C is only a schematic diagram, and the memory may also include other functional instructions, which is not limited by the present invention.

Optionally, the computer-executable instructions in the embodiments of the present application may also be referred to as application program codes, which are not specifically limited in the embodiments of the present application.

In a specific implementation, as an embodiment, the processor 301 may include one or more CPUs, such as CPU0 and CPU1 in FIG. 3C.

The basic principle of the multicast service transmission method provided by the embodiments of the present application is that some network elements in the existing 5G core network network architecture are functionally expanded, so that they have the function of adjusting the transmission mode of multicast data. For example, the SMF network element issues related parameters of the multicast threshold and the unicast threshold to the UPF network element, so that the UPF can decide the transmission mode according to the related parameters. Among them, the network element with extended functions can determine the transmission mode of the multicast data on the air interface of the 5G core network according to the number of user equipment receiving the multicast data, such as UPF, SMF, or RAN.

Exemplarily, the embodiment of the present application extends the functions of the RAN network element, the UPF network element, and the SMF network element in the network framework of the 5G core network shown in FIG. 3A and FIG. 3B.

Among them, the network framework of the above 5G core network may also include PCF network elements. The PCF is mainly used to provide the AMF or SMF with the policy rules for making the transmission decision, the policy rules for the transmission decision, and the related parameters of the strategy.

In the first implementation, the UPF network element can make a transmission decision according to the change in the number of user equipments receiving the same multicast data as an example to describe the method for transmitting the multicast service provided in the embodiment of the present application.

Among them, the UPF network element can be used as the core network network element in the network framework of the 5G core network, and the core network network element can determine the transmission mode of the air interface to transmit the multicast data (that is, the transmission mode of the RAN to transmit the multicast data).

It is understandable that the UPF can determine the number of user equipments served by the RAN according to the service request forwarded by the RAN, and adjust the air interface transmission mode of multicast data according to the number of user equipments receiving the same multicast data among the user equipments served by the RAN. The transmission decision made by UPF can be for the RAN to transmit multicast data in a unicast transmission mode, and the transmission decision made by the UPF can also be for the RAN to transmit multicast data in a multicast transmission mode. For UPF, the UPF receives the multicast data transmitted by the IPTV data network, and can send the multicast data to the RAN in a multicast manner, or it can send the multicast data to the RAN in a unicast transmission manner.

Exemplarily, if the UPF sends multicast data to the RAN in a multicast manner. Assuming that the transmission decision made by the UPF is unicast transmission, after the RAN receives the multicast data, it needs to copy multiple copies of the multicast data according to the number of user equipment receiving the multicast data, and send them to each user equipment respectively. Assuming that the transmission decision made by the UPF is multicast transmission, after receiving the multicast data, the RAN sends the multicast data to the user equipment in the manner of multicast transmission.

For another example, if the UPF sends multicast data to the RAN by unicast transmission, assuming that the transmission decision made by the UPF is unicast transmission, the RAN receives the multicast data transmitted by the UPF and transmits it to the user through unicast transmission. The device sends multicast data. Assuming that the transmission decision made by the UPF is multicast transmission, after receiving the multicast data sent by the UPF, the RAN sends the multicast data to the user equipment by means of multicast transmission.

Embodiment 1: When the UPF sends multicast data to the RAN in a multicast manner, the UPF can decide the transmission mode of air interface transmission according to the number of user equipments that receive the multicast data among the user equipments served by the RAN.

It is understandable that in the 5G core network, the user equipment changes the first channel (old channel) that is being played, and joins the second channel (new channel). Then the number of user equipments of the new channel and the number of user equipments of the old channel will both change, and the UPF may make different transmission decisions for the multicast data of the new channel and the transmission mode of the old channel.

It should be noted that before the user equipment goes online, the UPF can receive the relevant parameters of the transmission decision, or the UPF can configure the relevant parameters of the transmission decision. For example, multicast threshold, unicast threshold, and first time limit. As shown in FIG. 4A, the multicast service transmission method may include step 401 and step 402.

Step 401: The SMF sends the relevant parameters of the transmission decision to the UPF.

Among them, the relevant parameters include: unicast threshold, multicast threshold, and first time limit.

Exemplarily, the foregoing step 401 may be expressed as: the SMF sends an N4 association setup request (Association Setup Request)/N4 association modification request (Association Modification Request) to the UPF. Among them, N4 Association Setup Request or N4 Association Modification Request includes the above-mentioned related parameters.

A multicast service corresponds to a multicast group. When the number of user equipment in the multicast group is less than the unicast threshold, the UPF can make a transmission decision for unicast transmission. In some embodiments, when the number of user equipments in the multicast group is less than the unicast threshold, the UPF can make a transmission decision for unicast transmission. In other embodiments, when the number of user devices in the multicast group is less than or equal to the unicast threshold, the UPF can make a transmission decision for unicast transmission.

When the number of user equipments in the multicast group reaches the multicast threshold, UPF can make a transmission decision for multicast transmission. In some embodiments, when the number of user equipments in the multicast group is greater than the multicast threshold, the UPF can make a transmission decision for multicast transmission. In other embodiments, when the number of user equipments in the multicast group is greater than or equal to the multicast threshold, the UPF can make a multicast transmission transmission decision.

In a possible implementation, the multicast threshold is greater than the unicast threshold. It is understandable that when the number of user equipment exceeds the multicast threshold, the transmission decision is multicast transmission. When the number of user equipments is less than the unicast threshold, the transmission decision is the unicast threshold.

Assuming that the current RAN transmission mode is unicast transmission, the number of user equipment in the multicast list is increasing. Only when the number of user equipment in the multicast list exceeds the multicast threshold, the RAN transmission mode is changed from unicast transmission to group Broadcast transmission. Assuming that the current transmission mode of RAN is multicast transmission, the number of user equipments in the multicast list is decreasing. Only when the number of user equipments in the multicast list is less than the unicast threshold, the RAN transmission mode is changed from multicast transmission to Unicast transmission. In this way, the requirements for switching from unicast transmission to multicast transmission are higher (the multicast threshold is higher than the unicast threshold), and the method of multicast transmission saves air interface resources.

The first time limit can be used as a basis for judging that the number of user equipment is stable (or referred to as network stability). When the number of user equipments in the multicast group is always less than the unicast threshold within the first time limit, or the number of user equipments in the multicast group always reaches the multicast threshold within the first time limit. UPF can determine the corresponding transmission decision.

Step 402: UPF sends to SMF a response message that the above-mentioned related parameters are received.

Exemplarily, if step 401 is N4 Association Setup Request, step 402 may be: N4 Association Setup Response; if step 401 is N4 Association Modification Request, step 402 may be: N4 Association Modification Response (Association Modification) Response). Among them, N4 Association Setup Response/N4 Association Modification Response indicates that the UPF has received the above-mentioned related parameters and saved the related parameters.

In the first case, the user equipment joins a new channel.

As shown in FIG. 4B, the embodiment of the present application takes the first user equipment joining a new channel as an example, a flowchart of a method for transmitting a multicast service. It is understandable that after the above steps 401 and 402 are executed, if the service request sent by the first user equipment is for receiving multicast data, step 403a to step 412a are executed.

Step 403a: After the user equipment goes online, a PDU session channel is created through 5G-RG.

It is understandable that the foregoing process of creating a PDU session is basically the same as the process of establishing a PDU session for the user equipment to access the 5G core network through the 3rd Generation Partnership Project (3rd Generation Partnership Project, 3GPP) access technology. Wherein, the above step 401 and step 402 may be performed while step 403a is implemented, that is, after the user equipment goes online, a PDU session channel is created for the user equipment through 5G-RG. At the same time, the SMF sends the relevant parameters of the transmission decision to the UPF.

The SMF sends the relevant parameters of the transmission decision to the UPF, and the aforementioned relevant parameters may also include the second time limit and the third time limit. After the first user equipment sends a service request for receiving multicast data of the new channel, the first timer starts to count. The second time limit may be used as the time limit of the first timer, and the first timer is used to determine whether the user equipment is stably receiving multicast data of the new channel. If the first user equipment is still receiving multicast data of the new channel after the first timer expires, it is determined that the first user equipment is receiving multicast data stably.

Among them, the UPF according to the first request forwarded by the RAN (for example, the first user equipment requests to obtain the multicast service), the UPF can determine the number of user equipment requesting to obtain the multicast service among the user equipment served by the RAN, and according to the above-mentioned number of user equipment Make a transmission decision and send the transmission decision to the RAN. After the UPF sends the transmission decision to the RAN through the control network element (such as SMF and AMF), the third timer starts timing, and the third time limit can be used as the time limit of the third timer. Among them, the third timer is used to determine whether the RAN receives the transmission decision. In other words, after the UPF sends the transmission decision to the RAN through the SMF and AMF, after the third timer expires, the UPF can consider that the RAN has received the transmission decision.

It is understandable that the above steps 401 and 402 can be executed in step 403a. Specifically, if the above steps 401 and 402 are executed during the creation of a user equipment PDU session. Then step 401 is: N4 Session Establishment/Modification Request (Session Establishment/Modification Request). Then step 402 corresponds to: N4 Session Establishment/Modification Response (Session Establishment/Modification Response). Therefore, in the process of executing step 403a, step 401 and step 402 will be executed, and after step 403a is completed, step 404a can be executed.

Step 404a: The 5G-RG corresponding to the first user equipment sends a service request to the UPF through the RAN, and the service request is used for the first user equipment to request to receive multicast data of the new channel.

The user equipment may send a service request (such as the first request) through the PDU session, and the service request may be a request to obtain multicast data corresponding to a multicast service, that is, a request to receive multicast data corresponding to a new channel.

Specifically, the first user equipment (or STB) sends a service request to the 5G-RG. The 5G-RG sends the service request sent by the first user equipment to the UPF through the RAN.

Step 405a: In response to the service request, the UPF determines the authority of the 5G-RG corresponding to the first user equipment.

Specifically, if UPF determines that the 5G-RG corresponding to the first user equipment is authorized to receive the multicast data, UPF adds the first user equipment to the multicast list corresponding to the multicast service; if UPF determines that the first user equipment corresponds to The 5G-RG does not have the authority to receive the multicast data, and UPF prohibits adding the first user equipment to the multicast list corresponding to the multicast service.

Among them, when the 5G-RG forwards the service request of the user equipment, it is forwarded through the PDU session channel of the user equipment. After the UPF receives the corresponding service request, it can determine the 5G-RG identifier corresponding to the user equipment through the PDU session channel. Furthermore, the UPF can query the authority of the 5G-RG identifier corresponding to the user equipment, and only when the 5G-RG identifier corresponding to the user equipment has the authority to receive the multicast data of the new channel, can the user equipment be added to the corresponding multicast service. In the multicast list.

In a possible implementation, the SMF can set the service request to report the event. That is, after the UPF receives the service request forwarded by the RAN, it reports to the SMF that the service request of the user equipment is received. In this case, step 405a-1 is executed after step 405a.

Step 405a-1: UPF sends a service request report event to SMF.

The UPF determines that the 5G-RG identifier corresponding to the user equipment has the authority to receive the multicast data, and the UPF adds the user equipment to the multicast list corresponding to the multicast service. The UPF sends a service request report event to the SMF. The request report indicates that the user equipment has been added to the multicast list corresponding to the multicast service.

In another possible implementation manner, the PCF may also set the service request to report the event. That is to say, when the SMF receives that the user equipment is added to the multicast list corresponding to the multicast service, it reports the event that the user equipment is added to the multicast list to the PCF. In this case, after step 405a-1 is executed, step 405a-2 is executed.

Step 405a-2: The SMF sends the multicast list information to the PCF.

Where the SMF receives the service request reporting event, it can determine related information such as the multicast list corresponding to the multicast service. For example, the multicast list information may include a multicast address. UPF sends a service request report event to SMF. SMF updates the relevant information of the multicast address according to the above request report event. After the SMF updates the relevant information of the multicast address, it sends the updated information of the multicast address to the PCF to report to the PCF. PCF reports events.

It is understandable that if the related service request reporting event is not set in both the SMF and the UPF, there is no need to perform step 405a-1 and step 405a-2. In other words, if there is no related service request reporting event set in SMF and UPF, step 405a is executed and then step 406a to step 409a are executed.

Step 406a: The UPF determines that the first user equipment has the authority to receive the multicast data of the new channel, and the UPF sends the multicast data to the RAN serving the first user equipment through the first user plane channel in a unicast transmission manner.

It is understandable that after the UPF receives the service request of the first user equipment forwarded by the RAN, in order to ensure that the system responds to the first user equipment’s needs in a timely manner, the UPF can send to the RAN serving the first user equipment through the first user plane channel. Multicast data. The first user plane channel is the PDU session channel of the first user equipment. In other words, when the first user equipment joins a new channel, UPF determines that the 5G-RG corresponding to the first user equipment has the authority to receive multicast data of the new channel. The PDU session of the device sends multicast data to the RAN serving the first user equipment. In this way, it can be ensured that the 5G core network can respond to the needs of the first user equipment in a timely manner and improve user experience.

The UPF sends multicast data to the RAN serving the first user equipment through the first user plane channel, and the UPF will start the first timer. When the first timer expires, the first user equipment still receives the multicast of the new channel. Data, the UPF can determine that the first user equipment is stably receiving the multicast data of the new channel. Therefore, the UPF can make a transmission decision based on the number of user equipment in the current multicast list, and the UPF can send the first information to the RAN serving the first user equipment, and the first information includes the transmission decision.

It’s worth mentioning that if the first user equipment includes other user equipment in the multicast list of the new channel in the RAN serving the first user equipment before joining the new channel, the UPF can be sent to the RAN through the second user plane channel. Multicast data of the new channel. At this time, the first user equipment sends a service request for joining a new channel to the RAN through 5G-RG, and the RAN forwards the service request to UPF. The UPF also responds to the service request of the first user equipment and sends it to the RAN through the first user plane channel. Multicast data and start the first timer at the same time. In other words, in the process of counting the first timer, UPF not only needs to send the multicast data to the RAN through the second user plane channel (such as PDU session) in the manner of multicast transmission, but also needs to transmit the multicast data in the manner of unicast transmission. The multicast data is sent to the RAN through the first user plane channel. In addition, the RAN needs to forward multicast data for multiple user equipments through the second user plane channel, and forward multicast data to the first user equipment through the first user plane channel.

The second user plane channel is a PDU session channel of any user equipment in the multicast list, or the second user plane channel is a common session channel between the RAN and the UPF. That is, the second user plane may be a PDU session channel that does not belong to the user equipment in the multicast list.

In the embodiment of the present application, the UPF may send the multicast data to the RAN in the manner of multicast transmission. In other words, the UPF can send multicast data to the RAN serving the first user equipment and other user equipment in the multicast list through a user plane channel (such as a second user plane channel). In addition, after receiving the multicast data through a user plane channel, the RAN can send the multicast data to the first user equipment and other user equipments in the multicast list. Therefore, the UPF can determine that the first user equipment has the authority to receive the multicast data of the new channel. To ensure timely response to user needs, the UPF sends the multicast data to the RAN serving the first user equipment through the first user plane channel. Although the UPF needs to send the multicast data to the RAN through the second user plane channel in the manner of multicast transmission, it also needs to send the multicast data to the RAN through the first user plane channel in the manner of unicast transmission. However, after the RAN updates the air interface resources (that is, the RAN configures the corresponding air interface resources for the first user equipment), the UPF can send multicast data to the RAN through a user plane channel.

Specifically, the UPF can send multicast data to the RAN serving the first user equipment through the first user plane channel, and after the third timer, the UPF can send multicast data to the RAN through the second user plane channel through multicast transmission. Multicast data. The third timer is used to determine whether the RAN has updated the air interface resources for multicast data transmission. When the third timer expires, the UPF can confirm that the RAN has updated the air interface resources for multicast data transmission.

Step 407a: The first preset condition is satisfied, and the UPF sends the first information to the SMF.

Specifically, the first preset condition may be: the first user equipment still receives the multicast data of the new channel when the first timer expires.

The first timer is used to determine whether the first user equipment stably receives multicast data. The foregoing second time limit may be the timing time of the first timer, that is, the second time limit is set to determine whether the first user equipment receives the multicast data stably. Exemplarily, after the UPF receives the first request, it starts the first timer until the first timer expires (that is, after the timing of the first timer exceeds the second time limit), the first user equipment always receives The multicast data. That is to say, in the process of counting the first timer, the UPF never receives the service request from the first user equipment forwarded by the RAN to request to leave the multicast service.

It is understandable that based on the user's selection of the multicast service, the user equipment will join a new channel, and if the user is not interested in the content of the new channel, the user will switch the channel at any time. Since the number of user equipment in the multicast list will affect the transmission decision, UPF needs to adjust the transmission decision according to the number of user equipment in the multicast list. Setting the second time limit determines that the user equipment can stably receive the multicast data of the new channel, which helps the UPF to make a transmission decision when the user equipment in the multicast list is stable.

In some embodiments, the second time limit may be automatically generated by the UPF, may also be a time set by the staff, or may be transmitted to the UPF by the control network element (such as SMF). Among them, the second time limit may be 10 seconds, 15 seconds, 20 seconds, 30 seconds, and so on.

It is understandable that when the first user equipment receives multicast data stably, the UPF may also make a transmission decision based on the number of user equipments served by the RAN that receive the same multicast data. For example, the first user equipment stably receives multicast data, and the UPF determines that the number of user equipment in the RAN receiving the same multicast data is greater than the multicast threshold, and the UPF sends the first information to the RAN through the control network element. Wherein, the first information includes multicast transmission.

Specifically, the foregoing first preset condition may further include: the number of user equipment connected to the RAN in the multicast group reaches the preset multicast threshold when the fourth timer expires. Wherein, the number of user equipments reaching the multicast threshold may be that the number of user equipments is greater than or equal to the preset multicast threshold, or the number of user equipments is greater than the preset multicast threshold.

If the current RAN sends multicast data to the user equipment in a multicast transmission mode, the transmission decision made by the UPF is multicast transmission. In other words, after the RAN receives the transmission decision sent by the UPF, the RAN does not need to change the current transmission mode. If the current transmission mode of the RAN is unicast transmission, and UPF determines that the number of user equipments receiving the same multicast data among the user equipments served by the RAN reaches the preset multicast threshold, the transmission decision made by the UPF is multicast transmission. In other words, after the RAN receives the transmission decision sent by the UPF, the RAN can change the current multicast data transmission mode according to the transmission decision.

In a possible implementation manner, the foregoing first preset condition may further include: after the UPF receives the first request, the UPF may start a fourth timer until the fourth timer expires, and the number of user equipment meets the second The preset condition (the number of user devices exceeds the multicast threshold). Among them, the fourth timer is used to determine whether the number of user equipments in the multicast list is stable. That is, after the UPF receives the first request, the UPF determines that the number of user equipment reaches the preset multicast threshold, and the UPF can start the fourth timer. The first time limit is used as the timing time of the fourth timer. When the fourth timer expires (that is, after the timing time of the fourth timer exceeds the first time limit), the number of user equipments in the multicast list still reaches the preset multicast threshold.

It is understandable that during the timing of the fourth timer, the UPF may also receive a service request forwarded by the RAN. The service request may be a user equipment request to obtain a multicast service, and the service request may also be a user equipment request to leave the multicast service. business. However, during the timing of the fourth timer, the number of user equipment always reaches the foregoing multicast threshold.

For example, if the fourth timer expires and the UPF determines that the number of user equipments served by the RAN that receive the same multicast data reaches the preset multicast threshold, the transmission decision made by the UPF is multicast transmission. For another example, when or before the fourth timer expires, and the UPF determines that the number of user equipments in the multicast list is less than the multicast threshold, the UPF determines that the transmission decision is unicast transmission.

Exemplarily, the first time limit is a related parameter of the transmission decision sent by the SMF, the first time limit may be set by the SMF, and the first time limit may also be generated by the UPF. Wherein, the first time limit may be 30 seconds, 50 seconds, 60 seconds, 80 seconds, and so on.

It is worth mentioning that when UPF makes a transmission decision, it first determines whether the first user equipment receives multicast data stably through the first timer, and secondly determines whether the user equipment corresponding to the RAN receives the same multicast data through the fourth timer. Whether the number of devices is stable. In other words, the transmission decision made by the UPF is related to the first timer and the fourth timer.

Wherein, the first information may include: identification information of the first user equipment and identification information of the multicast service, identification information of the PDU session connection of the first user equipment and identification information of the multicast service, multicast list information, and the first indication One or more of. Wherein, the multicast list information includes the device identification information of the user equipment in the multicast group, the identification information of the user equipment connected to the RAN in the multicast group, or the session connection of the user equipment connected to the RAN in the multicast group One or more of the identifiers, the above-mentioned first indication is used to indicate to send multicast data to the first user equipment.

Exemplarily, assuming that the number of user equipments in the multicast group exceeds the multicast threshold, the transmission decision made by the UPF is multicast transmission. The RAN receives the first information from the UPF, the first information includes multicast transmission and control information, and the RAN can complete the air interface resource configuration according to the control information in the first information, and send the multicast data in a multicast manner. Assuming that the number of user equipments in the multicast group is less than the multicast threshold, the transmission decision made by the UPF is unicast transmission. The RAN receives the first information from the UPF. The first information includes unicast transmission and control information. The RAN sends a multicast to the 5G-RG corresponding to the user equipment in a unicast manner according to the user equipment identifier in the multicast list. data.

Step 408a: The SMF sends the first information to the RAN through the AMF.

It is understandable that the first information is used to indicate the manner in which the RAN transmits the multicast data corresponding to the multicast service, and the manner in which the multicast data is transmitted includes unicast transmission and multicast transmission. Therefore, it can be considered that the first information includes the transmission decision. Since the RAN and UPF network elements are data network elements, after the UPF makes a transmission decision, the first information can be sent to the RAN through the control network element (such as SMF and AMF).

Specifically, the SMF sends the first information to the AMF, and the AMF forwards the first information to the RAN.

Wherein, the first information may include: the identification information of the first user equipment and the identification information of the multicast service, the session connection identification information of the first user equipment and the identification information of the multicast service, the multicast list information, the information in the first instruction one or more.

Specifically, the multicast list information may include: the identification information of the user equipment in the multicast group, the identification information of the user equipment connected to the access network element in the multicast group, or the identification information of the user equipment connected to the access network in the multicast group. The session connection identifier of the user equipment connected to the network element. The first instruction is used to instruct to send multicast data to the first user equipment, and the multicast group corresponds to the user equipment that obtains the multicast service. That is, the RAN may send multicast data to the first user equipment according to the first indication in the first information.

Step 409a: UPF updates the user plane channel, and sends multicast data to the RAN through the second user plane channel.

Wherein, the second user plane channel is a unicast data transmission channel (such as a PDU session channel) established by any user equipment in the multicast list, or the second user plane channel may also be a multicast data transmission channel established by RAN and UPF (Such as general PDU conversation channel). If the second user plane channel is a general PDU session channel, the PDU session channel does not belong to any user equipment in the multicast list.

It is understandable that the first user equipment requests to receive the multicast data of the new channel, and the UPF responds to the service request of the first user equipment, and transmits to the first user equipment in the manner of unicast transmission through the PDU session channel of the first user equipment. The RAN sends multicast data. At the same time, if there are already other user equipments in the multicast list, and UPF sends multicast data to the RAN in the manner of multicast transmission. Then, the UPF can send multicast data to the RAN in a multicast transmission manner through the second user plane channel. In other words, the UPF sends the multicast data to the RAN both through multicast transmission and unicast transmission. In the embodiment of the present application, the UPF sends multicast data to the RAN in the manner of multicast transmission as an example. It does not mean that UPF always only sends multicast data to RAN through multicast transmission, but after UPF makes a transmission decision and sends the first information to RAN, UPF can send multicast data to RAN through multicast transmission.

Specifically, when a new user equipment (such as the first user equipment) in the user equipment corresponding to the RAN joins a new channel, the UPF uses unicast transmission to establish a unicast transmission channel (such as a PDU session channel) on the user equipment. The RAN corresponding to the first user equipment sends multicast data. When the preset conditions are met, the UPF can make a transmission decision. Among them, after the UPF makes a transmission decision, the UPF can modify the user plane channel (for example, from the first user plane channel to the second user plane channel), and send the group to the RAN by multicast transmission through the modified user plane channel Broadcast data. It is understandable that the UPF may use any user plane channel in the multicast list to send multicast data to the RAN in a multicast transmission manner, and the user plane channel may be the second user plane channel.

Please refer to Figure 4C for the specific implementation flow chart of UPF updating the session channel. As shown in Figure 4C, the process includes steps 4-1 to 4-8.

Step 4-1: The SMF puts the first information from the UPF into the N2 container service (container), and sends the N2 container to the AMF.

It is understandable that the N2 container here can be understood as a data packet. The data packet includes the first information. It is understandable that the first information also includes a manner of transmitting multicast data, such as unicast transmission or multicast transmission. In addition, the first information may also include a multicast information list and a multicast address. The N2 container here is only an example. Specifically, other data packets or other formats may be used to send the first information.

In some embodiments, the data format in the N2 container may be agreed upon by SMF and AMF, so that after receiving the N2 container, the AMF can recognize that the information in the N2 container needs to be sent to the RAN.

Step 4-2: The AMF receives the N2 container, and sends the first information in the N2 container to the RAN.

Among them, the AMF extracts the information in the N2 container, and forwards the first information in the N2 container to the RAN. The first information may include the method of transmitting the multicast data, so as to achieve the purpose of the UPF to control the transmission method of the RAN.

Step 4-3: The RAN receives the first information sent by the AMF, configures air interface resources for the user equipment according to the first information, and sends multicast data to the user equipment.

Specifically, if the current transmission mode of the RAN is multicast transmission, and the transmission decision in the first information is multicast transmission, then the RAN does not need to change the transmission mode of multicast data. The RAN may update the user equipment information in the multicast list according to the multicast list in the first information, and update the air interface resources according to the multicast list. If the current transmission mode of the RAN is unicast transmission, and the mode of transmitting multicast data in the first information is multicast transmission, the RAN needs to change the transmission mode of multicast data. The RAN can configure air interface resources according to the multicast list address in the control information, establish a multicast address, and send multicast data in a multicast manner.

In a possible implementation manner, after the RAN receives the multicast data transmission mode in the first information, if the multicast data transmission mode is different from the current transmission mode of the RAN, the RAN may use the current air interface resources. Determine whether to change the transmission method. In other words, the RAN can reject the UPF transmission decision. Even if the RAN rejects the UPF transmission decision, the RAN still needs to configure air interface resources according to the control information in the first information.

Step 4-4: The RAN sends N2 session response information to the AMF and reports that the air interface resource configuration is complete.

It is understandable that after the air interface resources are configured, the RAN can send multicast data to the user equipment in the multicast list according to the updated air interface resources. That is to say, even if the UPF only sends multicast data to the RAN through the second user plane channel, it can ensure that all user equipment in the multicast list can receive the multicast data.

Step 4-5: AMF sends a PDU session context (context) update request to SMF.

Wherein, the AMF receives the information that the air interface resource configuration of the RAN is complete, and can determine that the RAN can send multicast data to each user equipment in the multicast list. AMF sends a session context update request to SMF to request UPF to update the session channel.

Step 4-6: SMF sends a PDU session context update response to AMF.

Where the SMF receives the context update, the SMF can inform the AMF that the corresponding context update request has been received. Then, the SMF can determine that the air interface resources of the RAN have been configured according to the session context update request.

Step 4-7: The SMF sends an N4 session update request to the UPF, and the N4 session update request is used to request the UPF to update the PDU session channel.

It is understandable that the N4 session update request is used to request the UPF to update the session channel. Taking the UPF sending multicast data to the RAN through multicast transmission as an example, the UPF only needs to send the multicast data to the RAN through a user plane channel.

Wherein, since the first user equipment is a newly joined user equipment, in order to respond to the new channel service request of the first user equipment in a timely manner, the first user equipment is provided with multicast data of the new channel in a unicast transmission manner. The UPF determines that the first user is a user equipment that stably receives the multicast data of the new channel, and the UPF needs to update the user plane channel and ensure that the RAN can continue to send multicast data for the first user equipment after the user plane channel is updated. It is necessary to update the user plane channel after the RAN updates the air interface resource configuration. In this way, it can be ensured that all user devices in the multicast list can receive multicast data.

Step 4-8: UPF sends an N4 session update response to SMF.

Among them, the N4 session update response indicates that the UPF has received the aforementioned N4 session update request. The UPF receives the N4 session update request, and can update the user plane channel according to the N4 session update request. Thus, multicast data is sent to the RAN through a user plane channel.

Step 410a: The IPTV data network sends multicast data to the UPF.

In some embodiments, the IPTV data network sends multicast data of a new channel to the UPF, which may also be referred to as downlink multicast data. Among them, the IPTV data network sends multicast data to the UPF in the manner of multicast transmission, and this transmission method can be referred to as downlink multicast data.

Step 411a: The UPF sends multicast data to the RAN in a multicast transmission manner through the second user plane channel.

In a possible implementation manner, when the third timer expires, the UPF determines to send multicast data to the RAN through the second user plane channel.

The second user plane channel is a PDU session channel of any user equipment in the multicast list, or the second user plane channel is a general session channel. The general session channel may be a PDU session channel, and the PDU session channel does not belong to any user equipment in the multicast list.

It is understandable that in this embodiment, the UPF only sends multicast data to the RAN through multicast transmission, which does not mean that UPF always only sends multicast data to the RAN through multicast transmission. Instead, after UPF makes a transmission decision and determines that the air interface resource configuration of the RAN is complete, UPF updates the user plane channel as the second user plane channel and sends multicast data through the user plane channel. The RAN can send multicast data according to the configured air interface. Each user equipment in the multicast list sends multicast data.

The third timer is used to determine whether the RAN receives the above-mentioned multicast transmission transmission decision. The time limit of the third timer is the third time limit, and the third time limit may be determined by the UPF or configured by the SMF to the UPF. Exemplarily, after the UPF sends the transmission decision to the SMF, the third timer starts timing. When the third timer expires, the UPF can consider that the SMF has first sent to the RAN, and the RAN has updated the air interface resource configuration according to the first information.

In a possible implementation manner, if the RAN receives the first information, and the RAN feeds back the received first information to the UPF through the control network element. Then, the UPF may send multicast data to the RAN through the second user plane channel according to the response information fed back by the RAN to receive the first information. Since RAN and UPF are data network elements, UPF can send multicast data to the RAN through a user plane channel. The response information for receiving the first information fed back by the RAN needs to be sent to the UPF through the AMF network element and the SMF network element. In other words, the response information of receiving the first information fed back by the RAN cannot be directly transmitted to the UPF, and the third timer can be set to determine that the RAN has received the first information and updated the configuration of the air interface resources, thereby passing through the second user plane channel. Send multicast data to the RAN. Correspondingly, the UPF does not need to send multicast data to the first user equipment through the first user plane channel. Therefore, setting the third timer can improve the response speed of the system and save network resources.

Step 412a: The RAN sends the multicast data to the 5G-RG corresponding to the user equipment according to the transmission decision in the first information.

Wherein, the RAN receives the first information, and the first information includes transmission decision and control information, and the RAN can perform air interface resource configuration according to the transmission decision and control information.

The air interface resource configuration is completed, and the RAN receives the multicast data from the UPF through the second user plane channel. The RAN can send multicast data to the 5G-RG of the user equipment according to the transmission mode in the transmission decision, so as to realize the transmission of the multicast data.

In the second case, the user equipment leaves the old channel.

As shown in FIG. 4D, for the first user equipment to leave the old channel, a flowchart of a method for transmitting a multicast service provided in an embodiment of the present application. As shown in Fig. 4D, the method may include step 403b-step 410b.

It is understandable that after the above steps 401 and 402 are executed, if the service request sent by the first user equipment is to stop receiving multicast data, then step 403b to step 407b are executed.

Step 403b: The first user equipment leaves the old channel, and the 5G-RG corresponding to the first user equipment sends a service request to the UPF through the RAN.

Among them, the service request is used to request to stop receiving the multicast data corresponding to the old channel.

It is understandable that if the RAN sends the multicast data of the old channel to the user equipment by unicast transmission, after receiving the service request (or called the first request) of the first user equipment forwarded by the RAN, the UPF can immediately stop sending the multicast data to the first user. The RAN corresponding to the device sends the multicast data corresponding to the old channel. If the RAN sends the multicast data of the old channel to the user equipment is multicast transmission, after the UPF receives the service request (or called the first request) of the first user equipment forwarded by the RAN, the UPF can immediately update the multicast of the old channel in the RAN List, delete the first user equipment from the multicast list, and send the updated multicast list to the RAN through the control network element. The RAN is caused to stop sending multicast data to the 5G-RG corresponding to the first user equipment. Since the service request of the first user equipment is to stop the multicast data corresponding to the old channel, the number of user equipments in the multicast list of the old channel will change, and the UPF can adjust the transmission decision according to the number of user equipments of the old channel.

In a possible implementation, the SMF can set the service request to report the event. That is, the UPF receives the service request of the first user equipment, and reports the event that the first user equipment leaves the old channel to the SMF. In this case, after step 403b, step 403b-1 is executed.

Step 403b-1: UPF sends a service request report event to SMF.

The service request reporting event is that the UPF receives a service request from the first user equipment to stop receiving the old channel.

It is understandable that after receiving the service request sent by the first user equipment, the UPF can update the multicast list of the old channel according to the service request.

In another possible implementation manner, the PCF sets a service request to report an event. That is, the SMF receives the UPF service request reporting event, and updates the multicast address and related information according to the service request reporting event. Then, after step 403b-1, step 403b-2 is executed.

Step 403b-2: The SMF reports the multicast list address and related information to the PCF.

It is understandable that if there is no related report event set in UPF and SMF, step 403b-1 and step 403b-2 do not need to be performed. That is, step 404b to step 408b are executed after step 403b.

Step 404b: After receiving the service request of the first user equipment, the UPF triggers a second timer to count to determine whether the first user equipment stably leaves the multicast data of the old channel.

The second timer is used to determine whether the first user equipment stably stops receiving multicast data of the old channel. The foregoing second time limit may be used as the time of the second timer. That is, the second time limit is set to determine whether the first user equipment has left the multicast service stably. Exemplarily, when the UPF receives the first request, the first request is the first user equipment's request to leave the multicast service. When the UPF starts the second timer until the second timer expires (that is, the timing of the second timer exceeds the second time limit), the first user equipment always leaves the multicast service. That is to say, in the process of counting the second timer, the UPF never receives a service request from the first user equipment to obtain the multicast service. In this way, the UPF can determine that the first user equipment has left the multicast service stably.

It is understandable that based on the user equipment leaving the old channel and the UPF triggers the second timer to start timing, when the time of the second timer exceeds the second time limit, the UPF never receives the request from the first user equipment to join the old channel. According to the service request of the channel, the UPF can consider that the first user equipment stably leaves the old channel. Therefore, the second timer can determine whether the first user equipment has left the multicast service stably.

In some embodiments, the second time limit may be generated by the UPF, may also be a time set by the staff, or may be generated by the control network element (such as SMF) and transmitted to the UPF. Among them, the second time limit may be 10 seconds, 15 seconds, 20 seconds, 30 seconds, and so on.

Step 405b: The second timer expires, and the UPF determines that the number of user equipments in the multicast group meets the preset condition, and the UPF sends the first information to the SMF.

Wherein, the first information may include a transmission decision, and the transmission decision indicates a transmission mode of the RAN serving the first user equipment to transmit the multicast data. The preset condition is: if the UPF determines that the number of user equipments in the multicast list corresponding to the old channel is less than the unicast threshold, the transmission decision made by the UPF is unicast transmission. Specifically, if the user equipment in the multicast list corresponding to the old channel is less than the unicast threshold, or if the user equipment in the multicast list corresponding to the old channel is less than or equal to the unicast threshold, the transmission decision made by the UPF is unicast transmission.

Exemplarily, if the current transmission mode of the RAN is unicast transmission, and the first user equipment requests to stop receiving multicast data corresponding to the old channel, the number of user equipments on the old channel is reduced. The transmission decision made by UPF is to keep unicast transmission.

For another example, if the current transmission mode of the RAN is multicast transmission, the UPF needs to determine whether the number of user equipments receiving the old channel among the user equipments connected to the RAN meets the preset condition. For example, if the number of user equipment on the old channel is greater than the unicast threshold, the UPF makes a transmission decision to keep the multicast transmission. If the number of user equipment on the old channel is less than the unicast threshold, the UPF makes a transmission decision for unicast transmission.

In a possible implementation manner, a fourth timer may also be set in the UPF, the first time limit is used as the timing time of the fourth timer, and the fourth timer is used to determine whether the number of user equipments in the multicast list is stable. Specifically, the foregoing preset condition may be: the fourth timer is started to the fourth timer expires, and the number of user equipments is always less than the unicast threshold.

Specifically, after the UPF receives the first request, the UPF may start the fourth timer, and when the fourth timer expires, the number of user equipments is less than the unicast threshold. Wherein, the number of user equipments is always less than the unicast threshold within the time from the start of the fourth timer to the end of the fourth timer (that is, the timing of the fourth timer exceeds the first time limit).

It is understandable that during the timing of the fourth timer, the UPF may also receive a service request forwarded by the RAN. The service request may be a user equipment request to obtain a multicast service, and the service request may also be a user equipment request to leave the multicast service. business. However, during the timing of the fourth timer, the number of user equipments is always less than the unicast threshold.

For example, if the fourth timer expires and the UPF determines that the number of user equipments of the old channel is less than the multicast threshold, the transmission decision made by the UPF is unicast transmission.

Exemplarily, the first time limit is a related parameter of the transmission decision sent by the SMF, and the first time limit may be set by the SMF. Wherein, the first time limit may be 30 seconds, 50 seconds, 60 seconds, 80 seconds, and so on.

In the first implementation manner, the UPF receives the service request of the first user equipment to leave the old channel forwarded by the RAN, the UPF triggers the second timer, and the second timer expires. The UPF can consider that the first user equipment has stably left the old channel. Channel. UPF can make transmission decisions for old channels.

In the second implementation manner, the UPF receives the service request of the first user equipment to leave the old channel forwarded by the RAN, the UPF triggers the fourth timer, the fourth timer expires, and the UPF receives the old channel according to the user equipment connected to the RAN The number of user devices to make transmission decisions.

In the third implementation manner, when the UPF receives the service request of the first user equipment to leave the old channel forwarded by the RAN, it can first determine whether the first user equipment stops receiving the multicast data of the old channel stably through the second timer. Secondly, the fourth timer is used to determine whether the number of user equipments of the old channel meets the preset condition.

For example, the UPF receives a service request from the first user equipment to stop receiving the multicast data of the old channel, and the UPF starts the second timer and determines that the first user equipment stops receiving the multicast data stably. The UPF may start the fourth timer, and after the fourth timer expires, determine the transmission mode of the old channel according to the number of user equipments in the RAN connected user equipments that receive the old channel. In other words, the transmission decision made by the UPF is related to the first timer and the fourth timer.

Step 406b: The SMF sends the first information to the RAN through the AMF.

Specifically, the first information may include transmission decision and control information. Wherein, the control information may include one or more of the following: the number of user equipment in the multicast group, the identifier of the user equipment, the PDU session identifier of the user equipment in the multicast group, the multicast service address, the multicast list The STB information of the user equipment, the device identifier of the first user equipment, the identifier of the multicast service, the second indication, etc. The second indication may be used to indicate that the multicast data corresponding to the multicast service is no longer sent to the first user equipment. For example, if the RAN currently transmits the multicast data of the old channel in unicast transmission, and the transmission decision in the first information is unicast transmission, the RAN can stop sending the multicast data of the old channel to the first user equipment according to the second instruction. data.

Step 407b: The RAN updates the air interface resource configuration according to the first information.

Exemplarily, if the current transmission mode of the RAN is unicast transmission, after the first user equipment stops receiving multicast data of the old channel, the UPF determines that the RAN maintains unicast transmission. The RAN only needs to stop sending multicast data to the first user equipment.

For another example, if the current transmission mode of the RAN is multicast transmission, after the first user equipment stops receiving the multicast data of the old channel, it is assumed that the transmission decision made by the UPF is unicast transmission. The RAN needs to update the air interface resource configuration according to the transmission decision in the first information and the multicast list, configure the air interface for each user equipment in the multicast list corresponding to the old channel, and send the group to each user equipment according to the transmission mode of unicast transmission. Broadcast data.

Step 408b: The IPTV data network sends multicast data to the UPF.

Specifically, step 408b is the same as step 410a described above, and details are not described in detail.

Step 409b: The third timer expires, and the UPF sends multicast data to the RAN through the second user plane channel.

The second user plane channel is a PDU session channel of any user equipment in the multicast list of the old channel, or the second user plane channel is a general PDU session channel.

It is understandable that regardless of whether the transmission decision made by the UPF is unicast transmission or multicast transmission, the UPF can send multicast data to the RAN through the second user plane channel. If and only if there is only the first user equipment in the multicast list of the old channel, and the UPF receives the service request of the first user equipment to stop receiving the multicast data of the old channel, the UPF stops sending the multicast data of the old channel to the RAN .

Among them, the third timer is used to determine whether the RAN receives the above-mentioned multicast transmission transmission decision. The time limit of the third timer is the third time limit, and the third time limit may be determined by the UPF. Exemplarily, after the UPF sends the transmission decision to the SMF, the third timer starts timing. When the third timer expires, the UPF can consider that the SMF has sent the transmission decision and control information to the RAN, and the RAN has received the transmission decision and control information.

In a possible implementation manner, if the RAN receives the transmission decision and control information, and the RAN sends a response message that the transmission decision and control information is received to the UPF. Then, the UPF can send multicast data to the RAN through the second user plane channel according to the response information of the RAN. Since RAN and UPF are data network elements, UPF can send multicast data to the RAN through a user plane channel. The response information of the RAN needs to be forwarded to the UPF through the AMF network element and the SMF network element. In other words, the response information of the RAN cannot be directly transmitted to the UPF, and the third timer can be set to determine that the RAN has received the transmission decision and control information, so as to send multicast data to the RAN through the second user plane channel. Correspondingly, the UPF does not need to send multicast data to the first user equipment through the first user plane channel. Therefore, setting the third timer can improve the response speed of the system and save network resources.

Step 410b: The RAN sends multicast data to the 5G-RG corresponding to the user equipment according to the transmission decision.

In this embodiment, the UPF sends multicast data to the RAN in the manner of multicast transmission as an example to illustrate that the UPF makes a transmission decision as an example. It is understandable that when the UPF sends multicast data to the RAN in a unicast transmission manner, the manner in which the UPF makes a transmission decision can be the same as the above-mentioned decision manner in which multicast data is sent in a multicast transmission manner. In other embodiments, the UPF can also adjust the transmission mode of the multicast data according to the transmission decision.

Embodiment 2: The UPF can decide the transmission mode of the air interface transmission according to the number of users connected to the RAN to receive the multicast data, and the UPF can also adjust the transmission mode of sending the multicast data to the RAN.

Based on the same implementation principle as the above-mentioned embodiment 1, the user equipment changes the channel (old channel) being played, or the user equipment joins a channel (new channel). Will affect the transmission decision made by UPF.

In the first case, the user equipment joins a new channel.

Specifically, the UPF sends multicast data to the RAN by means of unicast transmission. If the UPF receives the service request of the first user equipment requesting to receive the multicast data of the new channel, if the UPF makes a transmission decision for multicast transmission. The transmission decision is used to control the transmission mode on the air interface side (ie, RAN). Among them, the UPF can also change the transmission mode, and the UPF can update the user plane channel and use a user plane channel to send multicast data to the RAN in the manner of multicast transmission.

It can be understood that the manner in which the UPF updates the user plane channel is the same as the specific implementation of step 408a, and will not be repeated here.

In the second case, the user equipment leaves the old channel.

Specifically, suppose that the UPF sends the multicast data of the old channel to the RAN in the manner of multicast transmission. When the UPF receives a service request from the first user equipment to stop receiving multicast data, if the UPF makes a transmission decision for unicast transmission. The transmission decision is used to control the transmission mode on the air interface side (ie, RAN). Among them, the UPF can also change the transmission mode, and the UPF can send multicast data to the RAN in a unicast transmission mode. In other words, UPF copies multiple copies of multicast data and sends them to the RAN.

It should be noted that, in some embodiments, the SMF network element may make a transmission decision based on changes in the number of user equipments receiving the same multicast data. Among them, the SMF network element can control the transmission mode on the air interface side, such as multicast transmission or unicast transmission. The SMF network element can also control the transmission mode for UPF to send multicast data to the RAN.

It is understandable that the SMF network element makes a transmission decision based on the number of user equipment, and the UPF needs to set a service request to report an event. That is, after receiving the service request of the user equipment, the UPF reports the service request of the user equipment to the SMF network element. The SMF network element can determine the number of user equipment in the multicast list according to the service request to make a transmission decision.

Embodiment 3: The SMF can determine the transmission mode of the air interface transmission according to the number of user equipments connected to the RAN to receive the multicast data, and the UPF can send the multicast data to the RAN in the manner of multicast transmission.

The service request sent by the first user equipment to the UPF may be a request to stop receiving multicast data, or a request to receive multicast data. Specifically, the first user equipment joins the first channel (new channel), or the first user leaves the second channel (old channel), so that the number of user equipment in the multicast list corresponding to the first channel and the second channel The number of user equipments in the corresponding multicast list changes. The UPF reports the received service request to the SMF, so that the SMF can make a transmission decision based on the number of user equipment in the multicast list.

In the first case, the user equipment joins a new channel.

As shown in FIG. 5A, this embodiment of the application provides a flowchart of a method for transmitting a multicast service, taking the first user equipment joining a new channel as an example. Including step 501a-step 512a.

Step 501a: After the user equipment goes online, a PDU session channel is created through 5G-RG.

Step 502a: The 5G-RG corresponding to the first user equipment sends a service request to the UPF through the RAN, and the service request is used for the first user equipment to request to receive multicast data of the new channel.

Specifically, the 5G-RG sends a service request (such as a first request) to the RAN, and the first request is a request for the first user equipment to receive multicast data of the new channel. The RAN forwards the first request to the UPF.

Step 503a: In response to the service request, the UPF determines the authority of the first user equipment.

Specifically, the UPF determines whether the first user has the authority to receive the multicast data of the new channel according to the 5G-RG identifier corresponding to the first user equipment.

If it is determined that the first user equipment is authorized to receive the multicast data, the first user equipment is added to the multicast list corresponding to the multicast service; if it is determined that the first user equipment is not authorized to receive the multicast data, the first user equipment is prohibited The device is added to the multicast list corresponding to the multicast service.

It should be noted that step 501a to step 503a in the embodiment of the present application are the same as step 403a to step 405a in the foregoing embodiment. For details, please refer to the specific description of the foregoing related steps, which will not be repeated here.

Step 504a: UPF sends a service request report event and control information to SMF.

The service request reporting event is used to report to the SMF that the UPF receives an event sent by the first user equipment requesting to receive the multicast data corresponding to the new channel.

Wherein, the control information may include: the identification information of the first user equipment and the identification information of the multicast service, the PDU session connection identification information of the first user equipment and the identification information of the multicast service, the multicast list information, and the information in the first instruction one or more. Wherein, the multicast list information includes the device identification information of the user equipment in the multicast group, the identification information of the user equipment connected to the RAN in the multicast group, or the session connection of the user equipment connected to the RAN in the multicast group The identifier and the foregoing first instruction are used to instruct to send multicast data to the first user equipment.

It can be understood that the multicast threshold and the unicast threshold are stored in the SMF. As a control network element, SMF can directly determine the number of user equipment in the multicast list of the new channel according to the UPF service request reporting event. In this way, SMF can make transmission decisions based on the number of user devices and the multicast threshold.

In some embodiments, after the SMF receives the UPF service request reporting event, it starts the first timer. The first timer is used to determine whether the first user equipment stably receives the multicast data. That is to say, after the first timer is started and the first timer expires, if the SMF has not received the report event of the first user equipment requesting to stop receiving multicast data of the new channel, the SMF determines that the first user equipment is stable. User equipment that receives multicast data.

It can be understood that the foregoing second time limit may be used as the time limit of the first timer. After the SMF receives the UPF service request reporting event, it starts the first timer until the first timer expires (that is, after the timing of the first timer exceeds the second time limit), the first user equipment always receives the group Broadcast data. That is, if the SMF does not receive the report event that the first user equipment leaves the multicast data reported by the UPF, the SMF can consider that the first user equipment is stably receiving the multicast data. Therefore, the SMF can determine whether the first user equipment is stably receiving multicast data through the first timer.

Wherein, the first timer is the same as the first timer in the foregoing embodiment, except that in the foregoing embodiment, the UPF starts the first timer, and in this embodiment, the SMF starts the first timer. Therefore, the related implementation of the first timer in the foregoing embodiment can also be applied to this embodiment. For example, the second time limit is the time of the first timer, etc., which will not be described in detail here.

It is worth mentioning that if the PCF sets the service request reporting event on the SMF, the SMF can report the request event to the PCF after receiving the UPF service request reporting event. Then step 504a-1 is executed after step 504a.

Step 504a-1: The SMF sends the multicast address and related information to the PCF.

Among them, the multicast address related information is used to report the related information of the multicast address of the new channel to the PCF, for example, the update of the multicast list corresponding to the multicast address, the update of the number of user equipments in the multicast list, and so on.

It is understandable that if the PCF does not set the service request reporting event on the SMF, step 505a to step 512a are executed after step 504a.

Step 505a: The UPF determines that the first user equipment has the authority to receive the multicast data of the new channel, and the UPF sends the multicast data to the 5G-RG of the first user equipment through the first user plane channel in a unicast transmission manner.

The first user plane channel is the PDU session channel of the first user equipment.

Wherein, step 505a is the same as step 406a in the foregoing embodiment, and the related description of the foregoing step 406a is still valid in the embodiment of the present application, and will not be repeated here.

Step 506a: The first timer expires and the SMF determines that the number of user equipments in the multicast group meets a preset condition, and the SMF makes a transmission decision.

Understandably, the transmission decision is made by the SMF. As the control network element, the SMF stores the multicast threshold and the unicast threshold, and the SMF can directly determine the number of user equipments according to the request report event sent by the UPF, so that the transmission decision can be made according to the number of user equipments.

In a possible implementation manner, the SMF determines that the number of user equipments in the multicast group meets a preset condition. Specifically, the number of user equipments is greater than the multicast threshold, or the number of user equipments is greater than or equal to the multicast threshold. Since the first user equipment is requesting to receive multicast data of the new channel, the number of multicast user equipments of the new channel increases. Therefore, it is necessary to make a transmission decision based on the multicast threshold.

Exemplarily, the current transmission mode of the RAN is multicast transmission, and the transmission decision made by the SMF according to the number of user equipments is that the multicast transmission can be maintained. As another example, the current transmission mode of the RAN is unicast transmission, and the transmission decision made by the SMF according to the user equipment may be to maintain unicast transmission, or it may be multicast transmission.

The preset condition may be: the fourth timer expires and the number of user equipment exceeds the multicast threshold. The fourth meeting device is used to determine whether the number of user equipment is stable. Specifically, when the first user equipment stably receives the multicast data of the new channel, the fourth timer is started. If the fourth timer times out and the number of user equipment always exceeds the multicast threshold, the number of user equipment is stable. SMF can make transmission decisions based on the number of user devices.

It should be noted that, in the embodiment of the present application, it always indicates the period of time from the start of the timer to the timeout of the timer. That is, the foregoing fourth timer times out and the number of user equipment always exceeds the multicast threshold, which means that from the start of the fourth timer to the timeout of the fourth timer, the number of user equipment always falls within the range of exceeding the multicast threshold. Wherein, the number of user equipment exceeding the multicast threshold specifically indicates that the number of user equipment is greater than the multicast threshold, or the number of user equipment is greater than or equal to the multicast threshold.

Exemplarily, a first time limit is also set in the SMF, and the first time limit is the timing time of the fourth timer. Wherein, the first time limit may be 30 seconds, 50 seconds, 60 seconds, 80 seconds, and so on.

Step 507a: The SMF sends the first information to the RAN through the AMF.

Specifically, the multicast list information includes the identification information of the user equipment in the multicast group, the identification information of the user equipment connected to the access network element in the multicast group, or the identification information of the user equipment connected to the access network element in the multicast group. The session connection identifier of the connected user equipment, the first indication is used to indicate to send multicast data to the first user equipment, and the multicast group corresponds to the user equipment that obtains the multicast service.

Step 508a: The RAN updates the air interface configuration resources according to the transmission decision.

It is understandable that the first information may also include a transmission decision. That is, the first information includes that the multicast data sent by the RAN to the user equipment is unicast transmission or multicast transmission. Then the RAN can configure air interface resources according to the transmission decision.

Exemplarily, it is assumed that the current transmission mode for the RAN to transmit multicast data is unicast transmission. If the first information includes unicast transmission and the first indication, the RAN may configure air interface resources for the first user equipment according to the unicast transmission mode, and send multicast data to the first user equipment. If the first information includes the multicast transmission and the first indication, the RAN may update the configuration of the air interface resource according to the multicast transmission, and send the multicast data to the first user equipment.

As another example, it is assumed that the current transmission mode for the RAN to transmit multicast data is multicast transmission. If the first information includes unicast transmission and the first indication, the RAN may update the configuration of the air interface resource and send multicast data to the first user equipment.

Step 509a: When the third timer expires, the SMF sends a request to update the user plane channel to the UPF.

When the third timer expires, the SMF sends a request to update the user plane channel to the UPF, and the request to update the user plane channel is used to request the UPF to send multicast data to the RAN through the second user plane channel.

The second user plane channel is a PDU session channel of any user equipment in the new channel multicast list, or the second user plane channel is a general session channel. The general session channel may be a PDU session channel, and the PDU session channel does not belong to any user equipment in the multicast list.

The third timer is used to determine whether the RAN receives the transmission decision sent by the SMF. The time limit of the third timer is the third time limit, and the third time limit may be determined by the SMF. Exemplarily, after the SMF sends the transmission decision to the AMF, the third timer is started. When the third timer expires, the SMF can determine that the RAN has received the transmission decision.

In a possible implementation manner, after receiving the transmission decision and control information, the RAN may send corresponding response information to the SMF. In this way, after the SMF receives the corresponding response information, it determines that the RAN has received the transmission decision. It is understandable that if the RAN sends and receives the response information of the transmission decision and control information to the SMF, it needs to be forwarded by the AMF. The SMF determines that the RAN has received the transmission decision and control information through the third timer, which can improve the response speed of the IPTV system and save resources on the network side.

Specifically, the specific implementation of UPF updating the user plane channel is the same as step 4-1 to step 4-8 in the foregoing embodiment, and will not be repeated here.

Step 510a: The IPTV data network sends multicast data to the UPF.

Step 511a: UPF sends multicast data to the RAN through the second user plane channel.

It should be noted that SMF can control the transmission mode of UPF. The SMF can control the UPF to send multicast data to the RAN through the second user plane channel through multicast transmission, and the SMF can also control the UPF to send the multicast data to the RAN through unicast transmission. Here, the UPF sends multicast data to the RAN through the second user plane channel in a multicast transmission manner as an example.

The second user plane channel is a unicast data transmission channel (such as a PDU session channel) established by any user equipment in the multicast group corresponding to the multicast service, or the second user plane channel is the access network element and A multicast data transmission channel established by a user plane network element (such as a general PDU session channel).

It is understandable that even UPF sends multicast data to the RAN in the manner of multicast transmission. When the UPF receives the first request from the first user equipment, the UPF may first send the multicast data to the RAN through the first user plane channel of the first user equipment. When the SMF determines that the first user equipment stably receives the multicast data, the SMF may send indication information to the UPF, instructing the UPF to send the multicast data to the RAN through the second user plane channel. That is, multicast data is sent to the RAN in the manner of multicast transmission.

Among them, the relevant implementation manner of UPF updating the user plane channel can refer to the relevant description in the foregoing embodiment 1, which will not be repeated here.

Step 512a: The RAN sends multicast data to the 5G-RG corresponding to the user equipment according to the transmission decision.

It should be noted that the above step 509a to step 512a are the same as the step 410a to step 412a in the above embodiment. That is to say, the relevant implementation details in the above steps can be applied here.

In the second case, the user equipment leaves the old channel.

As shown in FIG. 5B, for the first user equipment to leave the old channel, the flowchart of the method for transmitting the multicast service provided in the embodiment of the present application. As shown in FIG. 5B, it includes step 501b-step 508b.

Step 501b: The first user equipment leaves the old channel, and the 5G-RG corresponding to the first user equipment sends a service request to the UPF through the RAN.

It should be noted that step 501b is the same as step 403b in the foregoing embodiment. For details, please refer to the description of the foregoing related steps, which will not be repeated here.

Step 502b: UPF sends a service request report event and control information to SMF.

The service request reporting event is used to report the first user's request to stop receiving multicast data of the old channel to the SMF.

It is understandable that if the PCF sets the service request reporting event on the SMF, the SMF can report the request event to the PCF after receiving the UPF service request reporting event. Then step 502b-1 is executed after step 502b.

Step 502b-1: The SMF sends the multicast address and related information to the PCF.

Among them, the relevant information of the multicast address is used to request to report to the PCF the relevant information of the user equipment update in the multicast list of the old channel, for example, the update of the multicast list corresponding to the multicast address and the update of the number of user equipments in the multicast list Wait.

It is understandable that if the service request reporting event is not set in the SMF, after step 502b is executed, step 503b to step 508b are executed.

Step 503b: The second timer expires, and the SMF determines that the number of user equipments in the multicast group meets the preset condition, and the SMF makes a transmission decision.

The second timer is used to determine whether the first user equipment stably stops receiving multicast data of the old channel. Specifically, the SMF receives a service request sent by the UPF for the first user equipment to stop receiving multicast data of the old channel, and the SMF starts the second timer. When the second timer expires, and the first user equipment still stops receiving multicast data of the old channel. That is, if the SMF does not receive the report request event that the first user receives the multicast data of the old channel, the SMF can determine that the first user equipment stably stops receiving the multicast data of the old channel.

Among them, the preset condition may be: judging whether the number of user equipment is less than the unicast threshold. If the number of user equipment is less than the unicast threshold, the transmission decision is unicast transmission. If the number of user equipment is greater than the unicast threshold, the transmission decision is multicast transmission.

In a possible implementation manner, a fourth timer may be set in the SMF, and the first time limit is used as the time of the fourth timer. The fourth timer is used to determine whether the number of user equipments in the multicast list is stable. In this case, the first preset condition may be that the fourth timer expires and the number of user equipments is less than the unicast threshold.

It is understandable that after the SMF receives the report request sent by the UPF, the SMF determines that the first user equipment requests to leave the multicast data. The SMF may start the fourth timer. During the timing of the fourth timer, the SMF may also receive the report request sent by the UPF. Before the fourth timer expires or expires (that is, after the timing of the fourth timer exceeds the first time limit), the SMF has never received the report request of the first user equipment to obtain the multicast service sent by the UPF, and the SMF can be regarded as the first The number of users' equipment leaves the multicast service steadily.

For example, if the fourth timer is started until the fourth timer expires, and the SMF determines that the number of user equipments of the old channel is always less than the multicast threshold, the transmission decision made by the SMF is unicast transmission.

Exemplarily, the first time limit is a related parameter of the transmission decision preset in the SMF. Wherein, the first time limit may be 30 seconds, 50 seconds, 60 seconds, 80 seconds, and so on.

Step 504b: The SMF sends the first information to the RAN through the AMF.

Specifically, SMF sends transmission decision and control information to AMF, and AMF sends control information and transmission decision to RAN.

Step 505b: The RAN updates the air interface configuration resources according to the first information.

Exemplarily, if the current transmission mode of the RAN is unicast transmission, after the first user equipment stops receiving multicast data of the old channel, the SMF determines that the RAN maintains unicast transmission. The RAN only needs to stop sending multicast data to the first user equipment.

For another example, if the current transmission mode of the RAN is multicast transmission, after the first user equipment stops receiving the multicast data of the old channel, it is assumed that the transmission decision made by the SMF is unicast transmission. The RAN needs to update the air interface resource configuration according to the transmission decision and the multicast list, configure the air interface for each user equipment in the multicast list corresponding to the old channel, and send multicast data to each user equipment in the unicast transmission mode.

Step 506b: The IPTV data network sends the multicast data of the old channel to the UPF.

Step 507b: UPF sends multicast data to the RAN through the second user plane channel.

Step 508b: The RAN sends multicast data to the 5G-RG of the user equipment according to the transmission decision.

It should be noted that the above step 506b to step 508b are the same as the step 410a to step 412a in the above embodiment. That is to say, the relevant implementation details in the above steps can be applied here.

Embodiment 4: SMF decides the transmission mode of air interface transmission according to the number of user equipments receiving the multicast data, and SMF can also adjust the transmission mode of UPF.

Based on the same implementation principle as in the foregoing embodiment 3, the user equipment changes the first channel (old channel) being played, or the first user equipment joins the second channel (new channel). Will affect the number of user equipment in the multicast list of the channel, and make SMF make corresponding transmission decisions.

In the first case, the first user equipment joins a new channel.

Specifically, the UPF sends multicast data to the RAN by means of unicast transmission. SMF makes a transmission decision based on the report request event sent by UPF, if the transmission decision made by SMF is multicast transmission. Among them, the transmission decision is used to control the transmission mode on the air interface side (ie, RAN). SMF can also control the transmission mode of UPF. When SMF makes a transmission decision for multicast transmission, SMF can also control UPF to send multicast data to the RAN in the manner of multicast transmission.

In the second case, the first user equipment leaves the old channel.

Specifically, UPF currently sends multicast data to the RAN in the manner of multicast transmission. SMF makes a transmission decision based on the report request event sent by UPF, if the transmission decision made by SMF is unicast transmission. Among them, the transmission decision is used to control the transmission mode on the air interface side (ie, RAN). In this case, the SMF can also control the UPF to send data to the RAN in unicast transmission. That is, the UPF copies multiple copies of the multicast data, and sends the multicast data to the RAN through the PDU sessions in the multicast list.

In some embodiments, a transmission decision made by a RAN network element is taken as an example to illustrate the transmission mode of the multicast service provided in the embodiments of this application.

The RAN is a data network element, and the RAN needs to configure air interface resources according to the number of user equipments. Assuming a large number of user equipments, the RAN can use multicast transmission to send multicast data to the user equipment, so as to reduce the consumption of air interface resources and improve the utilization of air interface resources. The RAN can also allocate air interface resources for each user equipment, and send multicast data to the user equipment in a unicast transmission manner. In other words, after the RAN receives the multicast list, it can determine whether to use multicast transmission or unicast transmission according to the configuration of the air interface resources.

Embodiment 5: The RAN makes a transmission decision and decides whether the transmission mode of the air interface is unicast transmission or multicast transmission. UPF can send multicast data to the RAN in the manner of multicast transmission.

It is understandable that after the user equipment sends a service request to the UPF through the RAN, the UPF may report the service request to the SMF and update the multicast list, and the SMF may send the first information including the multicast list to the RAN. In this way, the RAN can determine the air interface transmission mode according to the multicast list in the first information. For example, the service request sent by the user equipment to the UPF via the RAN is a request to receive multicast data, the UPF updates the multicast list in response to the service request, and the UPF sends the updated multicast list to the SMF. The SMF sends the updated multicast list to the RAN through the AMF, and the RAN can request to update the air interface configuration according to the updated multicast list. It is understandable that if the user equipment joins a new channel or the user equipment leaves the old channel, the user equipment in the multicast list of the new channel and the multicast list of the old channel will change.

It should be noted that in the foregoing Embodiment 1 and Embodiment 2, the SMF sends the first information to the RAN. If the first information does not include the transmission decision, the first information includes the multicast list. Then the RAN receives the first information from the SMF, the RAN can determine the transmission mode for transmitting the multicast data according to the number of user equipments in the multicast list in the first information, and the RAN can be the one in the multicast list according to the determined transmission mode. The user equipment configures air interface resources. That is, in the foregoing embodiment, if the first information does not include the transmission decision, the RAN may make the transmission decision according to the multicast list in the first information.

In the first case, the first user equipment joins a new channel.

As shown in FIG. 6A, it is a flowchart of a method for transmitting a multicast service when the first user equipment joins a new channel according to an embodiment of this application. Including step 601a-step 611a.

Step 601a: After the user equipment goes online, the user equipment establishes a PDU session channel.

Step 602a: The first user equipment sends a first request to the UPF through the RAN, and the first request is used for the first user equipment to request to receive multicast data of the new channel.

Step 603a: The UPF receives the first request from the RAN, and determines the authority of the first user equipment.

Specifically, if the UPF determines that the first user equipment has the authority to receive the multicast data, the first user equipment is added to the multicast list corresponding to the multicast service; if the UPF determines that the first user equipment has the authority to receive the multicast data , It is forbidden to add the first user equipment to the multicast list corresponding to the multicast service.

Step 604a: It is determined that the first user equipment has the authority to receive the multicast data of the new channel, and the UPF sends the multicast data of the new channel to the RAN through the first user plane channel.

Wherein, the above step 601a to step 604a are the same as the above step 403a to step 406a, and the specific implementation of the above step can also be directly applied to the embodiment of the present application. In order to avoid repetition, it will not be repeated here.

Step 605a: UPF sends a service request to SMF to report event and control information.

Step 605a-1: The SMF sends the multicast address and related information to the PCF.

The foregoing step 605a and step 605a-1 are the same as the foregoing step 405a-1 and step 405a-2, and will not be repeated here.

Step 606a: The SMF sends first information to the RAN through AMF, where the first information is used to instruct to send multicast data corresponding to the multicast service to the first user equipment.

Wherein, the first information may be generated by UPF or SMF.

Exemplarily, the UPF may receive the first request sent by the RAN, and the first request is the first user equipment's request to obtain the multicast service. The UPF can start the first timer. When the first timer expires, the UPF does not receive the service request of the first user equipment to leave the multicast service sent by the RAN, and the UPF can determine that the first user equipment is the one that stably receives the multicast data. User equipment. The UPF may generate first information, where the first information is used to instruct to send multicast data to the first user equipment. The UPF may send the first information to the SMF, and request the SMF to forward the first information to the RAN.

As another example, the UPF may receive the first request sent by the RAN, where the first request is the first user equipment's request to obtain the multicast service. UPF can send a request report event for the first user equipment to obtain multicast data to the SMF, and the SMF can start the first timer. When the first timer expires, the SMF does not receive the first user equipment's request to leave the multicast service. Report the incident. Therefore, the SMF can determine that the first user equipment is a user equipment that stably receives multicast data. The SMF may generate first information, and the first information is used to instruct to send multicast data to the first user equipment.

Specifically, the SMF may send the above-mentioned first information to the RAN through the AMF.

It is understandable that when the UPF receives the first request from the RAN for the first user equipment to obtain multicast data, the UPF passes through the first user plane channel (that is, the PDU session channel of the first user equipment) in the manner of unicast transmission. Send multicast data to the RAN.

In some embodiments, the first information may further include: the identification information of the first user equipment and the identification information of the multicast service, the session connection identification information of the first user equipment and the identification information of the multicast service, and the multicast list information. One or more of.

Specifically, the multicast list information may include: the identification information of the user equipment in the multicast group, the identification information of the user equipment connected to the access network element in the multicast group, or the identification information of the user equipment connected to the access network in the multicast group. The session connection identifier of the user equipment connected to the network element.

Step 607a: The RAN determines a transmission mode for sending multicast data to the user equipment in the multicast group according to the first information.

In some embodiments, the first information may also include the number of user equipment. Wherein, when the first preset condition is met, the SMF sends first information to the RAN through AMF, and the first information includes the number of user equipments. Then, the RAN can determine the transmission mode of the multicast data according to the number of user equipments.

Exemplarily, take the UPF generating the first information as an example. Among them, a fourth fixer can also be set in UPF. Satisfying the first preset condition may include: the number of user equipment reaches the multicast threshold, or the fourth timer expires and the user equipment reaches the multicast threshold. The fourth timer is used to determine whether the number of user equipments in the multicast list is stable. That is, after the UPF receives the first request, the UPF determines that the number of user equipment reaches the preset multicast threshold, and the UPF can start the fourth timer. The first time limit is used as the timing time of the fourth timer. When the fourth timer expires (that is, after the timing time of the fourth timer exceeds the first time limit), the number of user equipments in the multicast list still reaches the preset multicast threshold. In this way, the UPF generates first information, and the first information includes the number of user equipment.

As another example, the first information generated by SMF is taken as an example. Among them, SMF can also set a fourth meeting device. Satisfying the first preset condition may include: the number of user equipment reaches the multicast threshold, or the fourth timer expires and the user equipment reaches the multicast threshold. The fourth timer is used to determine whether the number of user equipments in the multicast list is stable. That is, the UPF may send to the SMF a request report event that the first user equipment requests to obtain multicast data. When the SMF receives the report request event, the SMF determines that the number of user equipment reaches the preset multicast threshold, and the SMF can start the fourth timer. The first time limit is used as the timing time of the fourth timer. When the fourth timer expires (that is, after the timing time of the fourth timer exceeds the first time limit), the number of user equipments in the multicast list still reaches the preset multicast threshold. In this way, the SMF generates first information, and the first information includes the number of user equipment.

Wherein, after receiving the first information, the RAN may determine that the first information includes the number of user equipments. RAN decides the transmission mode of multicast data according to the number of user equipments. If the number of user equipment reaches the multicast threshold, the RAN can send multicast data to the user equipment by means of multicast transmission. If the number of user equipment is less than the unicast threshold, the RAN can send multicast data to the user equipment in a unicast transmission manner.

In other embodiments, the RAN may set a fourth timer. The first information received by the RAN may instruct the RAN to send multicast data to the first user equipment. The RAN may use the first information to count the number of user equipments currently receiving the multicast service, or the first information may also include the number of user equipments. When the number of user equipment reaches the multicast threshold, the RAN may start a fourth timer. Wherein, during the timing of the fourth timer, the RAN may also receive the first information sent from the core network element. When the fourth timer expires, the RAN may determine, according to the first information, that the fourth timer is in the process of timing The number of user devices receiving the multicast service always reaches the multicast threshold. Then, the RAN can send multicast data to the user equipment in the manner of multicast transmission.

Alternatively, during the timing of the fourth timer, the RAN learns that the number of user equipments receiving the multicast service is less than the unicast threshold according to the first information, and then starts the fourth timer. When the fourth timer expires, the RAN can determine, according to the first information, that the number of user equipments that receive the multicast service during the timing of the fourth timer is always less than the unicast threshold. Then, the RAN can send multicast data to the user equipment in a unicast transmission manner.

Step 608a: The RAN sends second information to the SMF, where the second information is used to indicate that the RAN has configured air interface resources for multicast data transmission.

It can be understood that when the RAN sends the second information to the SMF, the RAN has configured the air interface resources according to the determined transmission mode.

For example, if the transmission mode determined by the RAN is multicast transmission, the RAN may configure air interface resources according to the transmission mode of multicast transmission. The transmission mode determined by the RAN is unicast transmission, and the RAN can configure air interface resources in the unicast transmission mode.

Exemplarily, it is assumed that the current transmission mode of the RAN is unicast transmission. If the transmission decision made by the RAN is unicast transmission and the RAN receives the multicast data sent by the UPF, the RAN configures air interface resources for the first user equipment. If the transmission decision made by the RAN is multicast transmission, and the RAN receives the multicast data sent by the UPF, the RAN configures the corresponding air interface resources according to the transmission mode of the multicast transmission.

Step 609a: The IPTV data network sends the multicast data of the new channel to the UPF.

Step 610a: The UPF sends multicast data to the RAN in a multicast transmission manner through the second user plane channel.

It should be noted that when the UPF receives the first user equipment request to obtain multicast data sent by the RAN, the UPF can transmit to the first user plane channel (that is, the user plane channel of the first user equipment) through the first user plane channel in the manner of unicast transmission. The RAN to which the user equipment is connected sends multicast data.

In an embodiment, the RAN sends second information to the SMF, the second information indicating that the RAN has configured air interface resources for multicast data transmission. The SMF can forward the second information to the UPF so that the UPF can update the user plane channel. That is, the UPF sends multicast data to the RAN through the second user plane channel, and stops sending the multicast data to the RAN in a unicast transmission manner through the first user plane channel.

In another embodiment, if the RAN does not send the second information to the SMF, or the SMF does not forward the second information to the UPF.

Among them, a third timer can be set in the UPF. When the UPF sends the first information to the SMF, or when the UPF sends to the SMF the report event of the first user equipment requesting to obtain multicast data, the third timer is started, and the third timer is started. When the three timers expire, the UPF can consider that the RAN has completed the air interface resource configuration. In this way, the UPF can send multicast data to the RAN through the second user plane channel, and stop sending the multicast data to the RAN in a unicast transmission manner through the first user plane channel.

Alternatively, a third timer can be set in the SMF. When the SMF sends the first information to the RAN through AMF, or when the SMF receives a report event from the UPF sending the first user equipment requesting multicast data, the SMF starts the third timer Device. From the start of the third timer to the expiration of the third timer, the SMF can consider that the RAN has completed the air interface resource configuration. In this way, the SMF can instruct the UPF to send multicast data to the RAN through the second user plane channel, and stop sending the multicast data to the RAN in a unicast transmission manner through the first user plane channel.

Step 611a: The RAN sends multicast data to the 5G-RG according to the transmission decision.

Wherein, if the transmission decision of the RAN is multicast transmission, the RAN sends the multicast data to the user equipment in the manner of multicast transmission according to the configured air interface resources. If the transmission decision of the RAN is unicast transmission, the RAN sends the multicast data to the user equipment in the manner of unicast transmission according to the configured air interface resources.

In the second case, the first user equipment leaves the old channel.

Please refer to FIG. 6B, which is a flowchart of a method for transmitting a multicast service when a user equipment requests to leave an old channel according to an embodiment of this application. Including step 601b-step 608b.

Step 601b: The first user equipment leaves the old channel, and the 5G-RG sends a first request to the UPF. The first request is used to request to leave the old channel.

Step 602b: The second timer expires, and the UPF reports the request event and control information to the SMF.

Step 602b-1: The SMF sends the multicast address and related information to the PCF.

It is understandable that the above step 601b to step 602b-1 are the same as the above step 501b to step 502b-1, and the specific implementation details of the above step 501b to step 502b-1 can also be applied to the embodiments of the present application, and the details are not repeated.

Step 603b: The SMF sends the first information to the RAN through the AMF, where the first information is used to instruct to stop sending the multicast data corresponding to the multicast service to the first user equipment.

Wherein, the first information may be generated by UPF or SMF.

Exemplarily, the UPF may receive the first request sent by the RAN, and the first request is the first user equipment's request to leave the multicast service. The UPF can start the first timer. When the first timer expires, the UPF does not receive the service request of the first user equipment to obtain the multicast service from the RAN, and the UPF can determine that the first user equipment is leaving the multicast data stably. User equipment. The UPF may generate first information, where the first information is used to instruct to stop sending multicast data to the first user equipment. The UPF may send the first information to the SMF, and request the SMF to forward the first information to the RAN.

As another example, the UPF may receive the first request sent by the RAN, where the first request is the first user equipment's request to leave the multicast service. UPF can send to SMF the first user equipment request to leave the multicast data request report event, then SMF can start the first timer, when the first timer expires, SMF does not receive the first user equipment request to obtain the multicast service request Report the incident. Therefore, the SMF can determine that the first user equipment is a user equipment that has steadily left the multicast data. The SMF may generate first information, and the first information is used to instruct to stop sending multicast data to the first user equipment.

Step 604b: The RAN determines a transmission mode for sending multicast data to the user equipment in the multicast group according to the first information.

Wherein, the above step 604b is the same as the above step 607a, and will not be repeated here.

Step 605b: The RAN sends second information to the SMF. The second information is used to indicate that the RAN has configured air interface resources for multicast data transmission.

Step 606b: The IPTV data network sends the multicast data of the old channel to the UPF.

Step 607b: UPF sends multicast data to the RAN through the second user plane channel.

Step 608b: The RAN sends multicast data to the 5G-RG according to the transmission decision.

It should be noted that the above step 605b to step 608b are the same as the step 609a to step 611a in the above embodiment. That is to say, the relevant implementation details in the above steps can be applied here.

It is understandable that the first information in the foregoing embodiment may instruct the RAN to send multicast data to the first user equipment, or the first information may instruct the RAN to stop sending multicast data to the first user equipment. In other embodiments, the first information may not indicate to send multicast data to the first user equipment or stop sending multicast data to the first user equipment, but the first information may include the number of user equipments. In this way, the RAN can decide the transmission mode for transmitting the multicast data to the user equipment according to the number of user equipment in the first information. Here, taking the first information including the number of user equipments, and the RAN decides the transmission mode of the multicast data according to the number of user equipments as an example, the transmission method of the multicast service in the embodiment of the present application will be described. As shown in FIG. 6C, a method for transmitting a multicast service provided by an embodiment of this application. The method may include steps 601c-607c.

Step 601c: The UPF receives the first request sent by the RAN.

The first request may be a request by the first user equipment to obtain multicast data, or the first request may be a request by the first user equipment to leave the multicast data.

Step 601c-1: UPF sends a service request report event to SMF.

Step 601c-2: The SMF sends the multicast list information to the PCF.

Step 602c: The SMF sends first information to the RAN, where the first information is used to indicate the number of user equipments connected to the network element of the access network that receive the multicast service.

Exemplarily, if the foregoing first request is a request by the first user equipment to obtain a multicast service. The first information may include: identification information of the first user equipment and identification information of the multicast service, session connection identification information of the first user equipment and identification information of the multicast service, multicast list information, one of the first instructions, or Multiple.

Specifically, the multicast list information may include the identification information of the user equipment in the multicast group, the identification information of the user equipment connected to the access network element in the multicast group, or the identification information of the user equipment connected to the access network in the multicast group. The session connection identifier of the meta-connected user equipment, the first indication is used to indicate to send multicast data to the first user equipment, and the multicast group corresponds to the user equipment that obtains the multicast service.

In another example, if the above-mentioned first request is a request by the first user equipment to leave the multicast service. The first information may include one or more of the identification information of the first user equipment and the identification information of the multicast service, the session connection identification information of the first user equipment and the identification information of the multicast service, the multicast list information, and the second indication. indivual.

Specifically, the multicast list information may include the identification information of the user equipment in the multicast group, the identification information of the user equipment connected to the access network element in the multicast group, or the identification information of the user equipment connected to the access network in the multicast group. The session connection identifier of the meta-connected user equipment, the second indication is used to indicate to stop sending multicast data to the first user equipment, and the multicast group corresponds to the user equipment that obtains the multicast service.

Step 603c: The RAN receives the first information from the SMF, and the RAN determines the transmission mode for sending the multicast data to the user equipment in the multicast group according to the first information.

Wherein, after receiving the first information, the RAN may determine that the first information includes the number of user equipments. RAN decides the transmission mode of multicast data according to the number of user equipments. If the number of user equipment reaches the multicast threshold, the RAN can send multicast data to the user equipment by means of multicast transmission. If the number of user equipments is less than the unicast threshold, the RAN can use unicast transmission to send multicast data to the user equipment.

In some embodiments, the first request is a request by the first user equipment to obtain multicast data corresponding to the multicast service. After receiving the first information, the RAN starts the first timer. Before the first timer expires, the RAN sends multicast data to the first user equipment in a unicast transmission manner. After the first timer expires, the RAN may send multicast data to the first user equipment in a multicast transmission manner. That is, from the start of the first timer to the expiration of the first timer, the RAN does not receive the service request of the first user equipment to leave the multicast data. The RAN may consider that the first user equipment is stably receiving multicast data.

Wherein, the RAN determines a transmission mode for sending multicast data to the user equipment in the multicast group according to the first information. The RAN may determine whether the number of user equipments in the multicast group meets the second preset condition. If the number of user equipments in the multicast group meets the second preset condition, the RAN sends multicast data to the user equipment in a multicast transmission manner.

Specifically, the second preset condition may include: the number of user equipment reaches the multicast threshold, or the fourth timer expires and the number of user equipment reaches the multicast threshold. If the RAN determines that the first information also includes the number of user equipment, the RAN may start the fourth timer. Wherein, during the timing of the fourth timer, the RAN may also receive first information including the number of user equipments. When the fourth timer expires, the RAN may determine the first information received during the timing of the fourth timer. The number of user devices in the network always reaches the multicast threshold. Then, the RAN can send multicast data to the user equipment in the manner of multicast transmission.

In other embodiments, the first request is a request by the first user equipment to leave the multicast service. After the RAN receives the first information, it stops sending multicast data to the first user equipment and starts the second timer. After the second timer expires, the RAN never receives the first user equipment's request to obtain the corresponding multicast service. Service request for multicast data. The RAN can determine that the first user equipment has left the multicast service stably.

Wherein, the RAN determines a transmission mode for sending multicast data to the user equipment in the multicast group according to the first information. The RAN may determine whether the number of user equipments in the multicast group meets the second preset condition. If the number of user equipment in the multicast group meets the second preset condition, the RAN sends the multicast data to the user equipment in a unicast transmission manner.

Specifically, the second preset condition may include: the number of user equipments is less than the unicast threshold, or the fourth timer expires and the number of user equipments is less than the unicast threshold. If the RAN determines that the first information also includes the number of user equipment, the RAN may start the fourth timer. Wherein, during the timing of the fourth timer, the RAN may also receive first information including the number of user equipments. When the fourth timer expires, the RAN may determine the first information received during the timing of the fourth timer. The number of user devices in is always less than the multicast threshold. Then, the RAN can send multicast data to the user equipment in a unicast transmission manner.

Step 604c: The RAN configures air interface resources according to the determined transmission mode.

Among them, the transmission mode includes multicast transmission and unicast transmission. When the transmission mode determined by the RAN is multicast transmission, the air interface resources are configured according to the multicast transmission mode. When the transmission mode determined by the RAN is unicast transmission, the air interface resources are configured according to the unicast transmission mode.

Step 605c: The IPTV data network sends the multicast data of the old channel to the UPF.

Step 606c: UPF sends multicast data to the RAN through the second user plane channel.

Alternatively, a third timer can be set in the SMF. When the SMF sends the first information to the RAN via AMF, or when the SMF receives a report event from the UPF sending the first user equipment requesting multicast data, the SMF starts the third timer Device. From the start of the third timer to the expiration of the third timer, the SMF can consider that the RAN has completed the air interface resource configuration. In this way, the SMF can instruct the UPF to send multicast data to the RAN through the second user plane channel, and stop sending the multicast data to the RAN in a unicast transmission manner through the first user plane channel.

Step 607c: The RAN sends the multicast data to the user equipment in the multicast group in a determined transmission mode.

Among them, the determined transmission mode includes multicast transmission and unicast transmission.

Embodiment 6: The RAN makes a transmission decision and decides whether the transmission mode of the air interface is unicast transmission or multicast transmission. UPF can use unicast transmission to send multicast data to the RAN.

Based on the same principle as the above-mentioned embodiment 5, the user equipment changes the channel (old channel) being played, or the user equipment joins a channel (new channel). Will affect the RAN to make transmission decisions.

In the first case, the user equipment joins a new channel.

Specifically, the UPF sends multicast data to the RAN by means of unicast transmission. The UPF receives the service request of the first user equipment requesting to receive the multicast data of the new channel, and sends the report request event and control information to the SMF. The SMF sends the first information to the RAN through the AMF, where the first information includes multicast list information. The RAN can make transmission decisions based on the multicast list information. If the current transmission mode of the RAN is unicast transmission, and the transmission decision made by the RAN is also unicast transmission, the RAN does not need to change the transmission mode, and only adds an air interface resource for transmitting multicast data for the first user equipment. If the transmission decision made by the RAN is multicast transmission, the RAN needs to configure air interface resources according to the transmission decision, and send multicast data of the new channel to the user equipment in the multicast list through multicast transmission. In addition, the RAN can send the transmission decision to the SMF, the SMF can also send the transmission decision to the UPF, and the UPF can also change the current unicast transmission to a multicast transmission.

In the second case, the user equipment leaves the old channel.

Specifically, suppose that the UPF sends the multicast data of the old channel to the RAN in the manner of multicast transmission. When the UPF receives a service request from the first user equipment to stop receiving multicast data, it sends a report request event and control information to the SMF. The SMF sends the first information of control information to the RAN through the AMF, where the first information includes multicast list information. The RAN can make transmission decisions based on the multicast list information. If the current transmission mode of the RAN is unicast transmission, and the transmission decision made by the RAN is also unicast transmission, then the RAN does not need to change the transmission mode and just stops sending multicast data to the first user equipment.

It should be noted that the methods in the embodiments of the present application can also be applied to the network architecture of the 5G core network as shown in FIG. 3B. Because in the network architecture shown in FIG. 3B, M-UPF and M-SMF are used for multicast transmission. The M-UPF and the RAN are connected through a shared session channel, that is, the aforementioned second user plane channel. In this case, the 5G-RG corresponding to the first user equipment sends the first request to the U-UPF through the RAN. For example, the first user equipment sends the IGMP/MLD join to the U-UPF through the RAN.

In the above embodiment in which the UPF uses the air interface transmission mode, after receiving the first request from the first user equipment, the U-UPF may report the first request to the U-SMF. Among them, the U-SMF sends the first request to the M-UPF through the M-SMF, and the M-UPF makes a transmission decision for air interface transmission. It is understandable that the manner in which the M-UPF makes a transmission decision is the same as the manner in which the UPF makes a transmission decision, and will not be repeated here.

Wherein, suppose that the first request is that the first user equipment requests to receive multicast data of the new channel. Since the U-UPF receives the first request from the RAN, the U-UPF can send the first user equipment to the RAN corresponding to the first user equipment through the first user plane channel. Send multicast data. If other user equipment connected to the RAN also receives multicast data of the new channel, the M-UPF can send the multicast data to the RAN through the second user plane channel. At this time, the RAN forwards the data from the U-UPF to the first user equipment in a unicast transmission manner, and sends the data from the M-UPF to other user equipment in the multicast group in the original transmission manner. When the first timer expires and the first user still receives the multicast data of the new channel, the U-UPF will send a request to report the event to the U-SMF.

In the above-mentioned embodiment of the transmission mode of air interface transmission by SMF, after U-UPF receives the first request from the first user equipment, it can report the first request to U-SMF, and U-SMF transmits the first request. To M-SMF. M-SMF makes the transmission decision of air interface transmission.

Exemplarily, the flow chart of the multicast transmission method of applying the 5G core network as shown in FIG. 3B to transmit multicast data is shown in FIG. 6D. The method may include step 101-step 108.

Step 101: After the user equipment goes online, the 5G-RG corresponding to the user equipment establishes a session channel of the user equipment.

Step 102: The 5G-RG corresponding to the user equipment sends a first request to the U-UPF through the RAN.

Step 103: The U-UPF sends multicast data to the 5G-RG corresponding to the user equipment through the RAN in a unicast transmission manner.

Step 104: U-UPF sends a service request report event to U-SMF.

Step 105: The U-SMF forwards the service request to the M-SMF to report the event.

Step 106: The M-SMF makes a multicast transmission transmission decision according to the service request reporting event, and sends the transmission decision to the M-UPF.

Step 107: The IPTV data network sends multicast data to the M-UPF.

Step 108: The M-UPF sends multicast data to the 5G-RG corresponding to the user equipment through the RAN in the manner of multicast transmission.

For the specific implementation of the foregoing steps, reference may be made to the relevant steps in the foregoing Embodiment 1 and Embodiment 2, and the details are not repeated here.

It should be noted that the method in the above embodiment in which the RAN makes a transmission decision can also be applied to the network architecture of the 5G core network as shown in FIG. 3B. That is, the first information may not include a transmission decision. For example, the first information includes transmitting multicast data to the first user equipment, or the first information includes stopping the transmission of multicast data to the first user equipment. The RAN may determine the transmission mode of the multicast data according to the first information.

In a possible implementation manner, the first information may include the number of user equipments of the multicast data, and the RAN may make a transmission decision based on the number of multicast user equipments. For details, reference may be made to the descriptions in the above-mentioned related embodiments, which will not be repeated here.

It can be understood that, in order to implement the functions of any of the foregoing embodiments, network elements such as UPF, SMF, and RAN include hardware structures and/or software modules corresponding to each function. Those skilled in the art should easily realize that in combination with the units and algorithm steps of the examples described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed by hardware or computer software-driven hardware depends on the specific application and design constraint conditions of the technical solution. Professionals and technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered beyond the scope of this application.

The embodiments of the present application may divide functional modules for network elements such as UPF, SMF, and RAN. For example, each functional module may be divided corresponding to each function, or two or more functions may be integrated into one processing module. The above-mentioned integrated modules can be implemented in the form of hardware or software functional modules. It should be noted that the division of modules in the embodiments of the present application is illustrative, and is only a logical function division, and there may be other division methods in actual implementation.

For example, in the case of dividing various functional modules in an integrated manner, as shown in FIG. 7, a schematic structural diagram of a UPF network element provided in an embodiment of this application. The UPF network element may include a receiving unit 710, a sending unit 720, and a processing unit 730.

Wherein, the receiving unit 710 is configured to execute the above step 401, step 404a, step 410a and/or other processes used in the technology described herein. The sending unit 720 is configured to execute the above step 402, step 405a-1, step 407a, step 411a and/or other processes used in the technology described herein. The processing unit 730 is configured to execute the above step 405a, step 409a and/or other processes used in the technology described herein.

As shown in FIG. 8, it is a schematic structural diagram of an SMF network element provided by an embodiment of this application. The SMF network element may include a receiving unit 810, a sending unit 820, and a processing unit 830.

Wherein, the receiving unit 810 is configured to perform the foregoing step 504a and/or other processes used in the technology described herein. The sending unit 820 is configured to perform the above-mentioned step 504a-1, step 508a and/or other processes used in the technology described herein. The processing unit 830 is configured to execute the above-mentioned step 506a, step 409a and/or other processes used in the technology described herein.

As shown in FIG. 9, it is a schematic structural diagram of a RAN network element provided by an embodiment of this application. The RAN network element may include a receiving unit 910, a sending unit 920, and a processing unit 930.

Wherein, the receiving unit 910 is configured to execute the above-mentioned step 604a, step 606a, step 609a and/or other processes used in the technology described herein. The sending unit 920 is configured to perform the foregoing step 610a and/or other processes used in the technology described herein. The processing unit 930 is configured to perform the above step 607a and/or other processes used in the technology described herein.

It should be noted that all relevant content of the steps involved in the foregoing method embodiments can be cited in the functional description of the corresponding functional module, and will not be repeated here.

It should be noted that the foregoing sending unit (720, 820, and 920) and receiving unit (710, 810, and 910) may include radio frequency circuits. Specifically, the network element can receive and send wireless signals through a radio frequency circuit. Generally, the radio frequency circuit includes, but is not limited to, an antenna, at least one amplifier, a transceiver, a coupler, a low noise amplifier, a duplexer, and the like. In addition, the radio frequency circuit can also communicate with other devices through wireless communication. Wireless communication can use any communication standard or protocol, including but not limited to global system for mobile communications, general packet radio service, code division multiple access, broadband code division multiple access, long-term evolution, email, short message service, etc.

In an optional manner, when software multicast service transmission is used, it may be implemented in the form of a computer program product in whole or in part. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the procedures or functions of the embodiments of the present application are fully or partially realized. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. Computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, computer instructions may be transmitted from a website, computer, server, or data center through a cable (such as Coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) to transmit to another website site, computer, server or data center. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or a data center integrated with one or more available media. The usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, and a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium (for example, a solid state disk (SSD)).

The steps of the method or algorithm described in the embodiments of the present application may be implemented in a hardware manner, or may be implemented in a manner in which a processor executes software instructions. Software instructions can be composed of corresponding software modules, which can be stored in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, mobile hard disk, CD-ROM or any other form of storage known in the art Medium. An exemplary storage medium is coupled to the processor, so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium may also be an integral part of the processor. The processor and the storage medium may be located in the ASIC. In addition, the ASIC may be located in the detection device. Of course, the processor and the storage medium may also exist as discrete components in the detection device.

Through the description of the above embodiments, those skilled in the art can clearly understand that for the convenience and brevity of the description, only the division of the above-mentioned functional modules is used as an example for illustration. In practical applications, the above-mentioned functions can be allocated according to needs. It is completed by different functional modules, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above.

In the several embodiments provided in this application, it should be understood that the disclosed user equipment and method may be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the above-mentioned modules or units is only a logical function division. In actual implementation, there may be other division methods, for example, multiple units or components may be combined. Or it can be integrated into another device, or some features can be ignored or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms.

The units described above as separate components may or may not be physically separate, and the components displayed as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple different places. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments.

In addition, the functional units in the various embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units may be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or software functional unit.

If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solutions of the embodiments of the present application are essentially or the part that contributes to the prior art, or all or part of the technical solutions can be embodied in the form of a software product, and the software product is stored in a storage medium. It includes several instructions to make a device (which may be a single-chip microcomputer, a chip, etc.) or a processor (processor) execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), magnetic disk or optical disk and other media that can store program code .

The above are only specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention. It should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

A method for transmitting multicast services, characterized in that the method includes:

The core network element receives a first request, where the first request is used by the first user equipment to request to obtain the multicast service, or used for the first user equipment to request to leave the multicast service;

When the first preset condition is met, the core network element sends first information to the access network element serving the first user equipment, where the first information is used to instruct the access network element to transmit The manner of multicast data corresponding to the multicast service, and the manner of transmitting the multicast data includes unicast transmission or multicast transmission.
The method according to claim 1, wherein the first request is used when the first user equipment requests to obtain a multicast service;

The first preset condition includes: when a first timer expires, the first user equipment still receives the multicast data, wherein the first timer is used to determine whether the first user equipment receives the multicast data stably. Multicast data.
The method according to claim 1 or 2, wherein the core network element is a user plane network element, and the core network element sends the network element to the access network element serving the first user equipment. Before the first information, the method further includes:

The core network element sends the multicast data to the access network element through a first user plane channel, where the first user plane channel is a unicast data transmission channel established by the first user equipment .
The method according to claim 3, wherein after the core network element sends the first information to the access network element serving the first user equipment, the method further comprises:

The core network element sends the multicast data to the access network element through a second user plane channel, where the second user plane channel is any member of the multicast group corresponding to the multicast service. A unicast data transmission channel established by the user equipment, or the second user plane channel is a multicast data transmission channel established by the access network element and the core network element.
The method according to claim 3 or 4, wherein after the core network element sends the first information to the access network element serving the first user equipment, the method further comprises:

The core network element stops sending the multicast data to the access network element through the first user plane channel.
The method according to claim 4 or 5, wherein the method further comprises:

When the third timer expires, the core network element sends multicast data to the access network element through a second user plane channel, where the second user plane channel is the group corresponding to the multicast service A unicast data transmission channel established by any user equipment in the broadcast group, or the second user plane channel is a multicast data transmission channel established by the access network element and the core network element, wherein, The third timer is used to determine whether the network element of the access network has been configured with the air interface resource for the multicast data transmission.
The method according to claim 1 or 2, wherein after the core network element sends the first information to the access network element serving the first user equipment, the method further comprises:

The core network element instructs the user plane network element to send the multicast data to the access network network element through a second user plane channel, where the second user plane channel is a multicast group corresponding to the multicast service A unicast data transmission channel established by any user equipment in the group, or the second user plane channel is a multicast data transmission channel established by the access network network element and the user plane network element.
The method according to claim 7, wherein after the core network element sends the first information to the access network element serving the first user equipment, the method further comprises:

The core network element instructs the user plane network element to stop sending the multicast data to the access network network element through the first user plane channel, where the first user plane channel is the first user plane channel. A unicast data transmission channel established by user equipment.
The method according to claim 7 or 8, wherein the core network element instructing a user plane network element to send the multicast data to the access network network element through a second user plane channel comprises:

When the third timer expires, the core network element instructs the user plane network element to send the multicast data to the access network network element through the second user plane channel, wherein the third timing The device is used to determine whether the network element of the access network has been configured with the air interface resource for the multicast data transmission.
The method according to any one of claims 2-9, wherein the first preset condition further comprises: the number of user equipment connected to the access network element in the multicast group meets the second preset condition. Set conditions,

Wherein, the multicast group corresponds to a user equipment that obtains the multicast service, and the second preset condition includes that the number of user equipment exceeds a multicast threshold, or the second preset condition includes a fourth The timer expires and the number of user equipment exceeds the multicast threshold, where the fourth timer is used to determine whether the number of user equipment is stable.
The method according to claim 10, wherein the first information is used to indicate a manner of transmitting the multicast data comprises: the first information is used to instruct the access network element to perform multicast transmission Sending the multicast data to the first user equipment in a manner of.
The method according to claim 1, wherein the first request is used for the first user equipment to request to leave the multicast service, and the access network element requests to leave at the first user equipment Serving the first user equipment before the multicast service;

The first preset condition includes: when a second timer expires, the first user equipment still leaves the multicast service, wherein the second timer is used to determine whether the first user equipment leaves the multicast service stably. Multicast business.
The method according to claim 12, wherein the first preset condition further comprises: the number of user equipment connected to the access network element in the multicast group satisfies a third preset condition, wherein:

The multicast group corresponds to a user equipment that obtains the multicast service, and the third preset condition includes that the number of user equipments is less than a unicast threshold, or the third preset condition includes a fourth timer When the timeout expires and the number of user equipments is less than the unicast threshold, the fourth timer is used to determine whether the number of user equipments is stable.
The method according to claim 13, wherein the first information is used to indicate a manner of transmitting the multicast data comprises: the first information is used to instruct the access network element to transmit in unicast Sending the multicast data to the user equipment in the multicast group.
The method according to any one of claims 3 and 12-14, wherein the core network element is a user plane network element, and the method further comprises:

The core network element sends the multicast data to the access network element through a second user plane channel, where the second user plane channel is any member of the multicast group corresponding to the multicast service. A unicast data transmission channel established by the user equipment, or the second user plane channel is a multicast data transmission channel established by the access network element and the core network element.
The method according to any one of claims 1-2 and 12-15, wherein the core network element is a session management network element;

After the core network element sends the first information to the access network element serving the first user equipment, the method further includes:

The core network element instructs the user plane network element to send the multicast data to the access network network element through a second user plane channel, where the second user plane channel is a group corresponding to the multicast service A unicast data transmission channel established by any user equipment in the broadcast group, or the second user plane channel is a multicast data transmission channel established by an access network network element and the user plane network element.
The method according to any one of claims 12-16, the first information comprises:

One or more of the identification of the first user equipment and the identification information of the multicast service, multicast list information, and second instructions, wherein the multicast list information includes the user equipment in the multicast group Or the identification information of the user equipment connected to the access network element in the multicast group, and the second indication is used to indicate that the multicast data is no longer sent to the first user equipment , The multicast group corresponds to a user equipment that obtains the multicast service.
The method according to claim 4 or 9, wherein the method further comprises:

The core network element receives second information from the access network element, where the second information is used to indicate that the access network element has configured the air interface resource for the multicast data transmission;

The core network element sends the multicast data to the access network element through the second user plane channel according to the second information.
The method according to claim 8 or 16, wherein the method further comprises:

The core network element receives second information from the access network element, where the second information is used to indicate that the access network element has configured the air interface resource for the multicast data transmission;

According to the second information, the core network element instructs the user plane network element to send the multicast data to the access network network element through the second user plane channel.
The method according to any one of claims 1-6, 10-15, 18, wherein when the core network element is a user plane network element, the core network element is connected to the The network element sending the first information includes:

The core network element sends the first information to the access network element through the session management network element and the mobility management network element.
The method according to claim 20, wherein the core network element is a unicast user plane network element and a multicast user plane network element, and the multicast user plane network element is used to transmit all data in a multicast manner. The multicast data.
The method according to any one of claims 1-2, 7-20, 17-18, wherein when the core network element is a session management network element, the core network element is connected to the The first information sent by the network element of the network access includes:

The core network element sends the first information to the access network element through the mobility management network element.
The method according to claim 20, wherein the core network element is a unicast session management network element and a multicast session management network element, and the multicast session management network element is used to manage a multicast group, so The multicast group corresponds to user equipment that obtains the multicast service.
A method for transmitting multicast services, which is characterized in that it includes:

The network element of the access network receives the first information from the network element of the core network;

The network element of the access network determines, according to the first information, a transmission mode for sending multicast data to the user equipment in the multicast group;

The network element of the access network sends the multicast data to the user equipment in the multicast group in a determined transmission mode, where the determined transmission mode includes unicast transmission or multicast transmission.
The method according to claim 24, wherein the first information includes identification information of the first user equipment or session connection identification information of the first user equipment, and the first user equipment requests to obtain the multicast The data corresponds to a user equipment of a multicast service, and the access network element serves the first user equipment.
The method according to claim 24 or 25, wherein before the access network element receives the first information from the core network element, the method further comprises:

The access network element receives the multicast data through a first user plane channel, where the first user plane channel is a unicast data transmission channel established by a first user equipment;

The network element of the access network forwards the multicast data to the first user equipment in a unicast transmission manner.
The method according to claim 26, wherein after the access network element receives the first information from the core network element, the method further comprises:

The access network element forwards the multicast data from the second user plane channel to the first user equipment, where the second user plane channel is a single channel established by any user equipment in the multicast group. Or the second user plane channel is a multicast data transmission channel established between the access network network element and the user plane network element.
The method according to claim 24 or 25, wherein after the access network element receives the first information from the core network element, the method further comprises:

Start the first timer, and before the first timer expires, the network element of the access network sends the multicast data to the first user equipment in a unicast transmission mode;

After the first timer expires, and the first user equipment still receives the multicast data, the network element of the access network sends the multicast data to the first user equipment in a multicast transmission manner.
The method according to any one of claims 24-27, wherein the network element of the access network determines a transmission mode for sending multicast data to the user equipment in the multicast group according to the first information, and include:

The network element of the access network determines to send the multicast data to the first user equipment in a multicast transmission manner.
The method according to claim 29, wherein the determining by the access network element to send the multicast data to the first user equipment in a multicast transmission mode comprises:

When the number of user equipment connected to the access network element in the multicast group meets a second preset condition, the access network element determines to send to the first user equipment in the manner of multicast transmission In the multicast data, the second preset condition includes: the number of user equipment exceeds a multicast threshold, or the second preset condition includes that a fourth timer expires and the number of user equipment exceeds the multicast threshold. Threshold, where the fourth timer is used to determine whether the number of user equipments is stable.
The method according to claim 24, wherein the first information includes identification information of a first user equipment, and the first user equipment is a user equipment requesting to leave the multicast service corresponding to the multicast data, and The network element of the access network serves the first user equipment before the first user equipment requests to leave the multicast service.
The method according to claim 31, wherein the access network element determining the transmission mode for sending multicast data to the user equipment in the multicast group according to the first information comprises:

The network element of the access network determines to send the multicast data to the user equipment in the multicast group by means of unicast transmission, where the user equipment in the multicast group does not include the first User equipment.
The method according to claim 32, wherein the determining by the access network element to send the multicast data to the user equipment in the multicast group by means of unicast transmission comprises:

When the number of user equipments connected to the access network element in the multicast group meets a second preset condition, the access network element determines to transmit to the multicast group by unicast transmission. The user equipment of the user equipment sends the multicast data, wherein the second preset condition includes: the number of user equipments is less than the unicast threshold, or the second preset condition includes that the fourth timer expires and the number of user equipments is insufficient The unicast threshold, where the fourth timer is used to determine whether the number of user equipments is stable.
A core network element, characterized in that the core network element includes a receiving unit, a sending unit, and a processing unit, and the receiving unit, the sending unit, and the processing unit are used to implement claims as claimed in claims 1-33. Any one of the multicast service transmission method.
An access network network element, wherein the access network network element includes a receiving unit, a sending unit, and a processing unit, and the receiving unit, the sending unit, and the processing unit are used to implement -The transmission method of the multicast service described in any one of -33.