Communication method and device for multicast broadcast service

Abstract

The embodiment of the invention discloses a multicast broadcast service communication method and device, and the method comprises the steps: a first node receives a first PDCP (Data Convergence Protocol) serial number from a second node, and the first PDCP serial number is the PDCP serial number of a first data packet sent by the second node at a first moment; the first node sends the first PDCP serial number to a third node; the first node receives a second data packet from a third node, wherein the PDCP serial number of the second data packet belongs to a receiving window of a PDCP layer of user equipment UE; and the first node sends a second data packet to the UE, wherein the first data packet and the second data packet are associated with the first multicast broadcast service. According to the method, packet loss can be avoided when the same multicast broadcast service is transmitted.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of communication technology, and in particular, to a communication method and device for a multicast broadcast service. Background Art

[0002] Multicast and broadcast service (MBS) is a service for multiple user equipment (UE), such as live broadcast service, public safety service, batch software update service, etc. MBS data can come from the data server corresponding to the service. First, the data server sends the MBS data to the core network device, then the core network device sends the MBS data to the base station, and finally the base station sends the MBS data to at least one UE receiving the MBS service.

[0003] The base station architecture of the above base station can be a centralized unit (CU)-distributed unit (DU) separated base station architecture (CU-DU architecture for short), and specifically can be a shared DU architecture (only DU shared) in the CU-DU architecture, and the base station of this architecture is composed of at least two CUs and one shared DU. Among them, each CU can receive MBS data sent by the core network equipment corresponding to different operators, and then send the MBS data to the shared DU, and the shared DU sends the MBS data to the UE.

[0004] In the above-mentioned shared DU-only architecture, it is assumed that the base station changes from using one CU (for the convenience of description, referred to as the first CU) to transmit service data to using another CU (for the convenience of description, referred to as the second CU) to transmit the same service data, and the packet data convergence protocol (PDCP) configurations of the first CU and the second CU are the same, but the transmission progress of the MBS service between the first CU and the second CU is different. Then, if the PDCP sequence numbers (PDCP sequence numbers, PDCP SN) of the MBS data packets of the same service sent by the DU to the UE are different, and the PDCP sequence numbers of the data packets sent by the second CU are not within the PDCP receiving window for the UE to receive the data packets sent by the first CU, the UE will discard a large number of MBS data packets. Summary of the invention

[0005] The embodiments of the present application disclose a communication method and device for a multicast broadcast service, which can avoid packet loss when transmitting the same multicast broadcast service.

[0006] In a first aspect, the present application discloses a communication method for a multicast broadcast service, which may include:

[0007] The first node receives a first data convergence protocol PDCP sequence number from the second node, where the first PDCP sequence number is a PDCP sequence number of a first data packet sent by the second node at a first moment;

[0008] The first node sends the first PDCP sequence number to the third node;

[0009] The first node receives a second data packet from the third node, where a PDCP sequence number of the second data packet belongs to a receiving window of a PDCP layer of a user equipment UE;

[0010] The first node sends a second data packet to the UE, where the first data packet and the second data packet are associated with a first multicast broadcast service.

[0011] In the embodiment of the present application, the PDCP sequence number of the first data packet sent by the second node at the first moment is sent to the third node, so that the third node can configure the PDCP sequence number of the second data packet within the receiving window of the PDCP layer of the user equipment, wherein the first data packet and the second data packet are associated with the first multicast broadcast service. Then, even if the packet sending progress of the second node and the third node is different, since the PDCP sequence number of the second data packet belongs to the receiving window of the PDCP layer of the user equipment, the user equipment can successfully receive the second data packet, and a large number of second data packets will not be discarded.

[0012] The first moment is the moment when the first data packet is sent.

[0013] The first data packet and the second data packet are associated with the first multicast broadcast service, which may mean that the first data packet and the second data packet belong to the same multicast broadcast service. For example, the first data packet and the second data packet may carry the same associated service identifier (Associated session ID).

[0014] As a possible implementation manner, the second node includes a first user plane of the second node and a first control plane of the second node; the first node receives a first data convergence protocol PDCP sequence number from the second node, including:

[0015] The first node receives a first PDCP sequence number from a first control plane; the first PDCP sequence number is obtained by the first control plane from the first user plane.

[0016] The second node and the second node may be different CUs.

[0017] The embodiment of the present application uses control plane signaling to exchange PDCP SN numbers between different CUs, ensuring that the PDCP SN numbers of different CUs are negotiated to be the same, thereby avoiding packet loss caused by hopping.

[0018] As a possible implementation manner, the third node includes a second user plane of the third node and a second control plane of the third node; and the first node sends the first PDCP sequence number to the third node, including:

[0019] The first node sends the first PDCP sequence number to the second control plane; the second control plane is used to send the first PDCP sequence number to the second user plane; the first PDCP sequence number is used for the second user plane to configure the PDCP sequence number of the second data packet.

[0020] In the embodiment of the present application, PDCP SN numbers are exchanged between different CUs by using interaction of the user plane, so as to ensure that the PDCP SN numbers of different CUs are negotiated to be the same number, thereby avoiding packet loss caused by hopping.

[0021] As a possible implementation manner, the third node includes a second user plane of the third node; and the first node sends the first PDCP sequence number to the third node, including:

[0022] The first node sends the first PDCP sequence number to the second user plane; the first PDCP sequence number is used by the second user plane to configure the PDCP sequence number of the second data packet.

[0023] As a possible implementation manner, the second node includes a first user plane of the second node; and the first node receives a first data convergence protocol PDCP sequence number from the second node, including:

[0024] The first node receives a first PDCP sequence number from a first user plane.

[0025] As a possible implementation manner, the third node includes a second user plane of the third node; and the first node sends the first PDCP sequence number to the third node, including:

[0026] The first node sends the first PDCP sequence number to the second user plane; the first PDCP sequence number is used by the second user plane to configure the PDCP sequence number of the second data packet.

[0027] As a possible implementation manner, the third node includes a second user plane of the third node and a second control plane of the third node; and the first node sends the first PDCP sequence number to the third node, including:

[0028] The first node sends the first PDCP sequence number to the second control plane; the second control plane is used to send the first PDCP sequence number to the second user plane; the first PDCP sequence number is used for the second user plane to configure the PDCP sequence number of the second data packet.

[0029] As a possible implementation manner, before the first node sends the second data packet to the user equipment UE, the method includes:

[0030] The first node receives a first message from a third node, where the first message is used to instruct the first node to use a data packet from the third node, and the first message is sent by the third node to the first node after receiving a first PDCP sequence number.

[0031] In the embodiment of the present application, the third node may configure the PDCP sequence number of the second data packet based on the PDCP sequence number after receiving the first PDCP sequence number, and notify the first node to use the second data packet sent by the third node after the configuration is completed.

[0032] As a possible implementation manner, before the first node receives the first data convergence protocol PDCP sequence number from the second node, the method further includes:

[0033] The first node sends a first request to the second node, where the first request is used to request a first PDCP sequence number.

[0034] As a possible implementation manner, before the first node receives the first data convergence protocol PDCP sequence number from the second node, the method further includes:

[0035] The first node receives a first data packet from the second node, and a first PDCP sequence number of the first data packet belongs to a receiving window of a PDCP layer of the UE.

[0036] In a second aspect, the present application discloses a communication method for a multicast broadcast service, which may include:

[0037] The third node receives a first packet data convergence protocol PDCP sequence number from the first node, where the first PDCP sequence number is the PDCP sequence number of a first data packet sent by the second node at a first moment;

[0038] The third node sends a second data packet to the first node, and the PDCP sequence number of the second data packet belongs to the receiving window of the PDCP layer of the user equipment UE; the first data packet and the second data packet are associated with the first multicast broadcast service.

[0039] As a possible implementation manner, before the third node sends the second data packet to the first node, the method further includes:

[0040] The third node sends a first message to the first node, where the first message is used to instruct the first node to use a data packet from the third node.

[0041] As a possible implementation manner, before the third node sends the second data packet to the first node, the method further includes:

[0042] The third node configures the PDCP sequence number of the second data packet based on the first PDCP sequence number.

[0043] In a third aspect, the present application discloses a communication method for a multicast broadcast service, which may include:

[0044] The second node sends a first data convergence protocol PDCP sequence number to the first node, where the first PDCP sequence number is the PDCP sequence number of a first data packet sent by the second node at a first moment.

[0045] As a possible implementation, the method further includes:

[0046] The second node receives a first request from the first node, where the first request is used to request a first PDCP sequence number.

[0047] In a fourth aspect, the present application discloses a communication method for a multicast broadcast service, which may include:

[0048] The first node sends the first data packet to the user equipment UE based on the first multicast data radio bearer MRB configuration; the first data packet is sent by the second node to the first node;

[0049] The first node sends a first message to the UE, where the first message includes parameter information configured by the second MRB; the first MRB configuration is different from the second MRB configuration;

[0050] After sending the first message, the first node sends a second message to the UE, where the second message includes parameter information configured by the first MRB;

[0051] After sending the second message, the first node sends a second data packet to the UE based on the first MRB configuration, where the second data packet is sent from the third node to the first node; the first data packet and the second data packet are associated with the first multicast broadcast service.

[0052] The embodiment of the present application deletes and rebuilds the MRB in the MCCH modification period through the above-mentioned first message and second message, so that the UE can perceive that the MRB has changed and there is a new MRB reconstruction, which can solve the problem of packet loss when the first node switches from sending a first data packet to the UE to sending a second data packet in the same MRB.

[0053] As a possible implementation manner, before the first node sends the first message to the UE, the method further includes:

[0054] The first node receives a first request sent by the second node, where the first request includes a service identifier of the multicast broadcast service; the first request is used to request to release a session of the multicast broadcast service of the second node.

[0055] As a possible implementation manner, the service identifier of the multicast broadcast service includes at least one of a session identifier of the multicast broadcast service, a temporary multicast group identifier TMGI, and a service network identifier NID.

[0056] As a possible implementation, at least one configuration parameter in the parameter information of the first MRB configuration is different from that in the parameter information of the second MRB configuration, and the configuration parameter includes at least one of a data convergence protocol sequence number length, robust header compression, and a reordering timer.

[0057] As a possible implementation manner, when the moment when the first node receives the first request is within the first multicast control channel MCCH modification period, the moment when the first node sends the first message is within the second MCCH modification period, and the second MCCH modification period is the next MCCH modification period of the first MCCH modification period;

[0058] The time when the first node sends the second message is within the third MCCH modification period, and the third MCCH modification period is the next MCCH modification period of the second MCCH modification period.

[0059] In the embodiment of the present application, the first node may receive the first request, send the first message and send the second message in three consecutive MCCH cycles. This method may improve the speed of deleting and reconstructing the MRB.

[0060] As a possible implementation, when the first node sends the first message within the fourth MCCH modification period, the first node sends the second message within the fifth MCCH modification period, and the fifth MCCH modification period is the next MCCH modification period of the fourth MCCH modification period.

[0061] In the embodiment of the present application, the first node may send the first message and the second message in two consecutive MCCH cycles. This method may increase the speed of deleting and reconstructing the MRB.

[0062] In a fifth aspect, the present application discloses a communication device for a multicast broadcast service, which may include:

[0063] A receiving unit, configured to receive a first data convergence protocol PDCP sequence number from a second node, where the first PDCP sequence number is a PDCP sequence number of a first data packet sent by the second node at a first moment;

[0064] a sending unit, configured to send the first PDCP sequence number to a third node;

[0065] A receiving unit, configured to receive a second data packet from a third node, wherein a PDCP sequence number of the second data packet belongs to a receiving window of a PDCP layer of a user equipment UE;

[0066] The sending unit is used to send a second data packet to the UE, where the first data packet and the second data packet are associated with a first multicast broadcast service.

[0067] As a possible implementation manner, the second node includes a first user plane of the second node and a first control plane of the second node; a receiving unit, specifically configured to:

[0068] A first PDCP sequence number is received from a first control plane; the first PDCP sequence number is obtained by the first control plane from a first user plane.

[0069] As a possible implementation manner, the third node includes a second user plane of the third node and a second control plane of the third node; and a sending unit is specifically configured to:

[0070] The first PDCP sequence number is sent to the second control plane; the second control plane is used to send the first PDCP sequence number to the second user plane; the first PDCP sequence number is used for the second user plane to configure the PDCP sequence number of the second data packet.

[0071] As a possible implementation manner, the third node includes a second user plane of the third node; and a sending unit, specifically configured to:

[0072] The first PDCP sequence number is sent to the second user plane; the first PDCP sequence number is used for configuring the PDCP sequence number of the second data packet on the second user plane.

[0073] As a possible implementation manner, the second node includes a first user plane of the second node; and a receiving unit, specifically configured to:

[0074] A first PDCP sequence number is received from a first user plane.

[0075] As a possible implementation manner, the third node includes a second user plane of the third node; and a sending unit, specifically configured to:

[0076] The first PDCP sequence number is sent to the second user plane; the first PDCP sequence number is used for configuring the PDCP sequence number of the second data packet on the second user plane.

[0077] As a possible implementation manner, the third node includes a second user plane of the third node and a second control plane of the third node; and a sending unit is specifically configured to:

[0078] The first PDCP sequence number is sent to the second control plane; the second control plane is used to send the first PDCP sequence number to the second user plane; the first PDCP sequence number is used for the second user plane to configure the PDCP sequence number of the second data packet.

[0079] As a possible implementation manner, before sending the second data packet to the user equipment UE, the receiving unit is further configured to:

[0080] A first message is received from a third node, where the first message is used to indicate the use of a data packet from the third node, and the first message is sent by the third node after receiving a first PDCP sequence number.

[0081] As a possible implementation manner, before receiving the first data convergence protocol PDCP sequence number from the second node, the sending unit is further configured to:

[0082] A first request is sent to the second node, where the first request is used to request a first PDCP sequence number.

[0083] As a possible implementation manner, before receiving the first data convergence protocol PDCP sequence number from the second node, the receiving unit is further configured to:

[0084] A first data packet is received from the second node, where a first PDCP sequence number of the first data packet is within a receiving window of a PDCP layer of the UE.

[0085] In a sixth aspect, the present application discloses a communication device for a multicast broadcast service, which may include:

[0086] A receiving unit, configured to receive a first packet data convergence protocol PDCP sequence number from a first node, where the first PDCP sequence number is a PDCP sequence number of a first data packet sent by the second node at a first moment;

[0087] The sending unit is used to send a second data packet to the first node, the PDCP sequence number of the second data packet belongs to the receiving window of the PDCP layer of the user equipment UE; the first data packet and the second data packet are associated with the first multicast broadcast service.

[0088] As a possible implementation manner, before sending the second data packet to the first node, the sending unit is further configured to:

[0089] A first message is sent to the first node, where the first message is used to instruct the first node to use a data packet from the communication device.

[0090] As a possible implementation manner, before sending the second data packet to the first node, the device further includes a configuration unit, the configuration unit being configured to:

[0091] Based on the first PDCP sequence number, configure the PDCP sequence number of the second data packet.

[0092] In a seventh aspect, the present application discloses a communication device for a multicast broadcast service, which may include:

[0093] The sending unit is configured to send a first data convergence protocol PDCP sequence number to the first node, where the first PDCP sequence number is the PDCP sequence number of a first data packet sent by the sending unit at a first moment.

[0094] As a possible implementation manner, the device further includes a receiving unit, and the receiving unit is used to:

[0095] A first request is received from a first node, where the first request is used to request a first PDCP sequence number.

[0096] In an eighth aspect, the present application discloses a communication device for a multicast broadcast service, which may include:

[0097] A sending unit, configured to send a first data packet to a user equipment UE based on a first multicast data radio bearer MRB configuration; the first data packet is sent by a second node to a communication device;

[0098] A sending unit, configured to send a first message to a UE, where the first message includes parameter information of a second MRB configuration; the first MRB configuration is different from the second MRB configuration;

[0099] A sending unit, configured to send a second message to the UE after sending the first message, where the second message includes parameter information configured by the first MRB;

[0100] The sending unit is used to send a second data packet to the UE based on the first MRB configuration after sending the second message, where the second data packet is sent by the third node to the communication device; the first data packet and the second data packet are associated with the first multicast broadcast service.

[0101] As a possible implementation manner, before sending the first message to the UE, the device further includes a receiving unit, the receiving unit being configured to:

[0102] A first request sent by a second node is received, where the first request includes a service identifier of a multicast broadcast service; the first request is used to request to release a session of the multicast broadcast service of the second node.

[0103] As a possible implementation manner, the service identifier of the multicast broadcast service includes at least one of a session identifier of the multicast broadcast service, a temporary multicast group identifier TMGI, and a service network identifier NID.

[0104] As a possible implementation, at least one configuration parameter in the parameter information of the first MRB configuration is different from that in the parameter information of the second MRB configuration, and the configuration parameter includes at least one of a data convergence protocol sequence number length, robust header compression, and a reordering timer.

[0105] As a possible implementation manner, when the communication device receives the first request within the first multicast control channel MCCH modification period, the communication device sends the first message within the second MCCH modification period, and the second MCCH modification period is the next MCCH modification period of the first MCCH modification period;

[0106] The moment when the communication device sends the second message is within the third MCCH modification period, and the third MCCH modification period is the next MCCH modification period of the second MCCH modification period.

[0107] As a possible implementation, when the communication device sends the first message within the fourth MCCH modification period, the communication device sends the second message within the fifth MCCH modification period, and the fifth MCCH modification period is the next MCCH modification period of the fourth MCCH modification period.

[0108] In a ninth aspect, the present application discloses a communication device for a multicast broadcast service, which may be a network device in the above method embodiment, or a chip or processor arranged in the network device. The communication device for a multicast broadcast service includes a processor, the processor is coupled to a memory, the memory is used to store a program or instruction, and when the program or instruction is executed by the processor, the communication device for a multicast broadcast service executes the method executed by the network device, or the chip or processor in the network device in the above method embodiment.

[0109] In a tenth aspect, the present application discloses a communication device for a multicast broadcast service, which may be a network device in the above method embodiment, or a chip arranged in the network device. The communication device for a multicast broadcast service includes a processor and a memory, and the memory is used to store programs or instructions. When the program or instruction is executed by the processor, the communication device for a multicast broadcast service executes the method executed by the network device, or the chip or processor in the network device in the above method embodiment.

[0110] In an eleventh aspect, the present application discloses a communication device for a multicast broadcast service, which may be a network device in the above method embodiment, or a chip arranged in the network device. The communication device for the multicast broadcast service includes a communication interface and a processor, and optionally, also includes a memory. The memory is used to store a computer program or instruction, and the processor is coupled to the memory and the communication interface. When the processor executes the computer program or instruction, the communication device for the multicast broadcast service executes the method executed by the network device or the chip in the network device in the above method embodiment.

[0111] In the twelfth aspect, the present application discloses a communication system, which may include a network device that executes a communication method for a multicast broadcast service disclosed in the first aspect, a network device that executes a communication method for a multicast broadcast service disclosed in the second aspect, and a network device that executes a communication method for a multicast broadcast service disclosed in the third aspect.

[0112] In a thirteenth aspect, the present application discloses a computer-readable storage medium having a computer program or computer instructions stored thereon. When the computer program or computer instructions are executed by a processor, a communication method for a multicast broadcast service as disclosed in the above aspects is implemented.

[0113] In a fourteenth aspect, the present application discloses a chip, including a processor, for executing a program stored in a memory, and when the program is executed, the chip executes the above method.

[0114] As a possible implementation, the memory is located outside the chip.

[0115] In a fifteenth aspect, the present application discloses a computer program product, which includes a computer program code. When the computer program code is executed by a processor, the above-mentioned communication method for a multicast broadcast service is executed.

[0116] The beneficial effects of the above-mentioned fifth to fifteenth aspects are similar to the beneficial effects of the corresponding methods in the first to fourth aspects, and the detailed description can refer to the beneficial effects of the corresponding methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0117] Figure 1 is a schematic diagram of an MBS service transmission architecture provided in an embodiment of the present application;

[0118] Figure 2 This is a system architecture diagram of a MOCN provided in an embodiment of the present application;

[0119] Figure 3is a schematic diagram of an interface between a CU-CP, a CU-UP and a DU provided in an embodiment of the present application;

[0120] Figure 4 It is a schematic diagram of an architecture of a shared DU architecture provided in an embodiment of the present application;

[0121] Figure 5A This is a schematic diagram of a network architecture provided by an embodiment of the present application;

[0122] Figure 5B It is a schematic diagram of an application scenario provided by an embodiment of the present application;

[0123] Figure 6 It is a flowchart of another communication method for multicast broadcast services provided by an embodiment of the present application;

[0124] Fig. 7A It is a schematic diagram of a first node coordinating a first PDCP sequence number provided by an embodiment of the present application;

[0125] Figure 7B is another schematic diagram of a first node coordinating a first PDCP sequence number provided by an embodiment of the present application;

[0126] Figure 7C is another schematic diagram of a first node coordinating a first PDCP sequence number provided by an embodiment of the present application;

[0127] Fig.7D is another schematic diagram of a first node coordinating a first PDCP sequence number provided by an embodiment of the present application;

[0128] Figure 8 It is a flowchart of another communication method for multicast broadcast services provided by an embodiment of the present application;

[0129] Fig. 9A It is a flowchart of another communication method for multicast broadcast services provided in an embodiment of the present application;

[0130] Fig. 9B It is a schematic diagram of changing the PDCP SN size provided by an embodiment of the present application;

[0131] Fig.10 It is a flowchart of another communication method for multicast broadcast services provided in an embodiment of the present application;

[0132] Fig.11 It is a structural diagram of a communication device for a multicast broadcast service provided in an embodiment of the present application;

[0133] Fig.12 It is a structural diagram of a communication device for a multicast broadcast service provided in an embodiment of the present application;

[0134] Fig.13 It is a structural diagram of another communication device for multicast broadcast services provided in an embodiment of the present application;

[0135] Fig.14 It is a structural diagram of another communication device for multicast broadcast services provided in an embodiment of the present application;

[0136] Fig.15 It is a structural diagram of a communication device for a multicast broadcast service provided in an embodiment of the present application;

[0137] Fig.16 It is a structural diagram of another communication device for multicast broadcast services provided in an embodiment of the present application. DETAILED DESCRIPTION

[0138] The embodiments of the present application will be described clearly and in detail below with reference to the accompanying drawings in the embodiments of the present application.

[0139] The terms used in the implementation section of this application are only used to explain the specific embodiments of this application and are not intended to limit this application.

[0140] First, the definitions of technical terms that may appear in the embodiments of the present application are given:

[0141] (1) MBS service transmission architecture

[0142] Multicast and Broadcast Service (MBS) is a service for multiple user equipment (UE), such as live broadcast service, public safety service, batch software update service, etc.

[0143] Figure 1 A schematic diagram of an MBS service transmission architecture is exemplified.

[0144] like Figure 1 As shown, the data server can send MBS data (MBS service) to the core network device (CoreNetwork, CN), and then the core network device sends the MBS data to the base station (gNB), and finally the base station sends the MBS data to at least one UE receiving the MBS service. Among them, the data server can be the provider of MBS service data (MBS server).

[0145] When sending from the core network to the base station, the MBS service is transmitted through a common transmission channel MBS session (MBS session), and each MBS session can contain at least one MBS QoS flow. When sending from the base station to the UE, the data packet is transmitted through the MBS data radio bearer (MBS data radio bearer, MRB). For an MBS radio bearer, there are two transmission modes: the first can use PTM (point to multi-point) transmission mode; the second can use PTP (point to point, point to point) transmission mode.

[0146] In the embodiment of the present application, the MBS service may be a multicast service, a broadcast service, or a groupcast service, which is not limited in the embodiment of the present application.

[0147] (2) Wireless access network sharing (RAN sharing)

[0148] In order to avoid duplication of network infrastructure, save overall network investment, ease the huge financial pressure faced by the construction of the fifth generation mobile networks (5G), and accelerate the commercialization of 5G, it is possible to consider increasing the network co-construction and sharing. RAN sharing mainly means that a RAN can be connected to the core network equipment of multiple operators. Multiple operators can jointly build RAN, or one operator can build RAN alone, while other operators rent the RAN network of that operator.

[0149] Among them, RAN sharing can include 5G RAN common carrier sharing (Multi-Operator Core Network, MOCN) and 5G RAN sub-carrier sharing (Multi-Operator Radio Access Network, MORAN). The following is an introduction from the perspectives of resource sharing intensity and business independence:

[0150] In the sharing mode of MOCN, the core network is independent; configuration management, alarm management, performance indicators, etc. need to be managed by the main operator. Some performance indicators can be monitored by distinguishing the Public Land Mobile Network (PLMN), and cannot be activated separately. The indoor baseband processing unit (Building Base band Unit, BBU), RRU radio remote unit (Remote Radio Unit, RRU) / active antenna unit (Active Antenna Unit, AAU) are all shared, and the site-side RAN equipment is fully shared. Sharing a certain segment or several segments of carriers of different operators forms a continuous large-bandwidth shared carrier, which can reduce infrastructure and equipment costs.

[0151] Figure 2 The system architecture diagram of MOCN is shown as an example.

[0152] like Figure 2 As shown, the system architecture may include core network equipment of two operators, namely, the 5G core network of operator A and the 5G core network of operator B; it also includes a shared base station gNodeB and a shared cell. Among them, users in the shared cell can use the mobile network PLMN A of operator A and the mobile network PLMN B of operator B.

[0153] In the sharing mode of MORAN, the core network is independent, 5G RAN equipment is shared, and the cells and spectrum are independent. Configuration management and alarm management all need to be managed by the main operator. Performance indicators can be monitored separately, and cell-level features can be planned and opened separately. BBU sharing connects to RRU / AAU of the same manufacturer. RRU / AAU is independent of each operator, and each carrier is independently configured and managed. On the wireless side, different logically independent cells are used to provide independent use to multiple operators.

[0154] The RAN sharing in the embodiment of the present application adopts the MOCN sharing method.

[0155] (3) CU-DU architecture

[0156] Among them, CU stands for Centralized Unit, and DU stands for Distributed Unit. The CU-DU separated base station architecture is a new base station architecture introduced in 5G. In the 4G architecture, each base station is deployed independently and connected to the 4G core network respectively, while in the 5G architecture, the DU parts of different base stations are deployed independently, but the CU parts of different base stations are deployed centrally.

[0157] From the perspective of physical module structure, the internal structure of a 4G base station is divided into several modules, including BBU, RRU and antenna. Each base station has a set of BBU and is directly connected to the core network through the BBU. Under the 5G CU-DU separation architecture, the original RRU and antenna are merged into AAU, and the BBU is split into DU and CU. Each base station has a set of DU, and multiple sites share the same CU for centralized management.

[0158] From the perspective of the protocol stack structure, in a 5G base station, the physical bottom layer in the BBU of the original 4G base station is sunk to the AAU for processing, and the physical upper layer, media access control (MAC) layer and radio link control protocol (RLC) layer with high real-time requirements are placed in the DU for processing, while the PDCP layer, service data adaptation protocol (SDAP) layer and radio resource control (RRC) layer with low real-time requirements are placed in the CU for processing.

[0159] In the CU-DU architecture, the interface between CU and DU is called F1 interface. CU can be further separated into control plane (CP) and user plane (UP). Hereinafter, the control plane of CU is referred to as CU-CP and the user plane of CU is referred to as CU-UP.

[0160] Figure 3 The interface diagram between CU-CP, CU-UP and DU is exemplarily shown.

[0161] See also Figure 3 , the interface between CU-CP and CU-UP is called E1 interface. Among them, a base station generally has only one CU-CP, multiple CU-UPs and DUs. A DU can only be connected to one CU-CP, and a CU-UP can only be connected to one CU-CP. The interface between CU-CP and DU is called F1-C, and the interface between CU-UP and DU is called F1-U. It can be seen that there can be multiple F1-Us between a DU and multiple CU-UPs. F1-U is usually used for data transmission and can also be called an F1-U tunnel.

[0162] (4) Separate RAN Sharing Architecture

[0163] The split RAN sharing architecture can include a shared CU-DU architecture and a shared DU-only architecture. In the shared CU-DU architecture, multiple operators share one CU (referred to as shared gNB-CU) and one DU (referred to as shared gNB-DU); while in the shared DU-only architecture, multiple operators have their own corresponding CUs, the CUs are not shared, and multiple operators share one DU (referred to as shared gNB-DU).

[0164] Figure 4 An architectural diagram of a shared DU-only architecture is exemplified.

[0165] Among them, the architecture includes the core network equipment 5G core (5GC) corresponding to the three operators, which can be specifically 5GC PLMNA corresponding to operator A, 5GC PLMNB corresponding to operator B, and 5GCPLMNC corresponding to operator C; and gNB-CU corresponding to the three 5G cores, which can be gNB-CU PLMNA corresponding to operator A, gNB-CU PLMNAB corresponding to operator B, and gNB-CU PLMNAC corresponding to operator C; and a shared DU, namely SharedgNB-DU.

[0166] Among them, the 5G core and gNB-CU communicate through the NG interface, such as Figure 4 As shown, 5GC PLMNA and gNB-CUPLMNA communicate through NG (PLMNA); 5GC PLMNB and gNB-CU PLMNB communicate through NG (PLMNB); 5GC PLMNC and gNB-CU PLMNC communicate through NG (PLMNC).

[0167] Among them, the gNB-CU and Shared gNB-DU communicate through the F1 interface, such as Figure 4 As shown, gNB-CUPLMNA and Shared gNB-DU communicate through F1 (PLMNA); Shared gNB-DU and gNB-CU PLMNB communicate through F1 (PLMNB); Shared gNB-DU and gNB-CU PLMNC communicate through F1 (PLMNC).

[0168] like Figure 4As shown in the figure, gNB-CU is not shared. It receives the temporary multicast group identifier (TMGI) and service identifier of each operator and then sends it to the shared gNB-DU. In this architecture, since the gNB-CU of each operator cannot know the TMGI and service identifier of other operators, the gNB-CU cannot determine whether the broadcast services of different operators are the same service. Therefore, the gNB-CUs of different operators need to send the TMGI and service identifier to the shared gNB-DU to let it determine whether it is the same service.

[0169] The shared CU-DU architecture can be composed of multiple operator core networks, a shared gNB-CU and a shared gNB-DU. The shared gNB-CU receives data from the core networks of different operators. For example, operator A will establish a data transmission channel with the gNB-CU, also known as an NG-U tunnel. During the tunnel establishment process, operator A will send TMGI A and service identifier X to the shared gNB-CU. Similarly, operator B will send TMGI B and service identifier X to the shared gNB-CU. After receiving this information, the shared gNB-CU will determine whether the broadcast services of the two operators are the same service based on the service identifier X. Alternatively, the shared gNB-CU sends the service identifier X to the shared gNB-DU, allowing the shared gNB-DU to determine whether the broadcast services of the two operators are the same service.

[0170] In the embodiment of the present application, the separated RAN sharing architecture may adopt a shared DU-only architecture.

[0171] (5) MBS control channel (MCCH)

[0172] In actual applications, since the UE may start receiving MBS services at any time, in order to ensure that the UE can obtain MBS control information in time and then obtain MBS services, the network side periodically sends MBS control information through MCCH. In existing communication systems, the transmission process of MCCH information involves two periods: MCCH repetition period RP (repetation period) and MCCH modification period MP (modification period). Each MCCH modification period includes multiple MCCH repetition periods; in each MCCH repetition period, the network sends an MCCH message once. The content of MCCH transmission in each MCCH repetition period within the same MCCH modification period is basically the same. However, for some information that needs to change quickly, the data transmitted in each MCCH repetition period may also be different.

[0173] When a UE wants to receive MBS data, it generally needs to read BCCH (Broadcast Control Channel) first, and obtain the location and configuration information of MCCH according to the system broadcast message; then read the MCCH channel to obtain the relevant configuration information of MTCH; and obtain MBS data by reading the MTCH channel. In the above process of UE obtaining MBS data, the UE obtains the location and configuration of MCCH through the system broadcast message.

[0174] The MCCH configuration includes the MRB configuration, and the MRB configuration includes the PDCP configuration.

[0175] (6) PDCP Configuration for Broadcast MCCH

[0176] In the existing broadcast technology, the CU configures the PDCP configuration of the broadcast MCCH, and then sends it to the DU through a message (such as BROADCAST CONTEXT SETUP REQUEST), and the message carries the above PDCP configuration.

[0177] For example, the BROADCAST CONTEXT SETUP REQUEST includes an MBS CU to DU RRC Information information element, which includes the PDCP configuration of the broadcast MRB. It should be noted that in the embodiment of the present application, the PDCP configuration of the broadcast MCCH may also be referred to as the PDCP configuration of the broadcast MRB, PDCP configuration or MRB PDCP configuration.

[0178] Since the air interface MCCH information is full configuration information, delta configuration is not supported, that is, new configuration is not supported. If the default PDCP configuration is used, different CUs may generate the same PDCP configuration.

[0179] In the embodiment of the present application, the MRB PDCP configuration may include a PDCP SN size (PDCP SN Size), a robust header compression (Robust Header Compression, ROHC) and a reordering timer (t-Reordering).

[0180] (7) PDCP corresponding receiving window

[0181] At present, in the process of data transmission in the field of mobile communications, the receiving device will maintain a receiving window at the PDCP layer. The receiving window has a fixed window length, for example, the window length is 1 / 2SN, SN is the maximum sequence number of the PDCP layer data packet. When the data starts to be received, the receiving window is located from the PDCP layer data packet with sequence number 0 to the data packet with sequence number 1 / 2SN-1. When the data packet with sequence number 0 is received, the receiving window will move along the direction of the data packet sequence number from small to large. Assuming that the sequence number of the next PDCP layer data packet that is not received correctly is k, and k is greater than 0, the PDCP layer will The data packets with sequence numbers 0 to k-1 that have been received are delivered to the application layer of the receiving device, and the receiving window is moved to the data packets with sequence numbers k to k+1 / 2SN-1. The main reason why the PDCP layer data packet is not received correctly is that the RLC layer of the receiving device has not completed the reception of the RLC layer data packet corresponding to the data packet. This part of the RLC layer data packets that have not been received must be received through retransmission at the RLC layer, and after the retransmission is completed, the RLC layer of the receiving device is delivered to the PDCP layer, so that the incorrectly received data packets with the corresponding sequence numbers of the PDCP layer are received.

[0182] Regarding the MRB PDCP configuration in the RAN sharing scenario, for the only DU shared scenario, several solutions (cases) were proposed in the 3GPP RAN3120 meeting, as shown below:

[0183] Case 1: The DU decides which CU’s MRB PDCP configuration to select;

[0184] Case 2: DU coordinates the MRB PDCP configurations of multiple CUs to enable different CUs to have the same MRB PDCP configuration;

[0185] Case 3: Use default values ​​or preconfigured methods.

[0186] In the current discussion, for the only DU shared scenario, since DU is shared, the underlying MRB configurations generated by DU are all the same, that is, except for the MRB PDCP configuration, all other configurations are the same. For CU, since the broadcast PDCP configurations are the above three items, different CUs may generate the same MRB PDCP configuration even without any coordination and using the default configuration. Therefore, for the above three cases, regardless of whether the CUs coordinate to the same PDCP configuration, different CUs may generate the same PDCP configuration.

[0187] Since the DU uses a set of air interface configurations to send data to the UE, if different CUs use the same MRB PDCP configuration, the DU will generate the same MRB configuration and send it to the UE.

[0188] Assume that PLMNA is currently used for service transmission, and PLMNB and PLMNC can also provide service transmission. If you want to use PLMNB for service transmission, you need to change the PDCP configuration of PLMNA CU to the PDCP configuration of PLMNB CU. Assuming that the PDCP configuration before and after the modification is the same, then, from the UE's point of view, the MRB has not been modified, and the UE will continue to identify whether to receive data packets from the DU with the current PDCP receiving window. Assuming that the packet sending progress of different core networks is different, the PDCP SN number before and after the modification will jump. For example, the PDCP SN number of the data packet sent before the modification is 200, and the PDCP SN number of the data packet sent after the modification is 50. Then, the data packet of PLMNB is outside the current PDCP receiving window of the UE, so a large number of data packets are discarded, causing the UE to receive no data for a period of time.

[0189] Based on the above, in order to better understand the communication method and related devices for a multicast broadcast service proposed in the present application, the network architecture applied in the embodiments of the present application is described below.

[0190] See also Figure 5A , Figure 5A It is a schematic diagram of a network architecture provided in an embodiment of the present application.

[0191] like Figure 5A As shown, the network architecture may include a network device 501 and a user device 502. The network device 501 may be a CU-DU architecture, where the network device 501 includes at least two CUs and a shared DU. Figure 5A exemplarily shows that at least two CUs of the network device 501 are the first CU and the second CU. The shared DU may also be referred to as the first node, the first CU may also be referred to as the second node, and the second CU may also be referred to as the third node.

[0192] The user equipment 502 may be connected to the network equipment 501 in a wireless manner, and may be connected to the core network through the network equipment 501. The user equipment 502 may be fixed or movable.

[0193] It should be noted that the first CU, the second CU and the shared DU may be separate network devices, respectively. In the embodiment of the present application, the three separate network devices, namely, the first CU, the second CU and the shared DU, are referred to as network device 501. Alternatively, at least two of the first CU, the second CU and the shared DU may also be units in a shared network device, for example, the network device 501 is a shared base station, and the first CU, the second CU and the shared DU are three units in the shared base station, respectively.

[0194] The network device 501 may be an entity for transmitting or receiving signals, or may be a device for communicating with the user device 502. The network device may be a base transceiver station (BTS) in a global system for mobile communications (GSM) system or a code division multiple access (CDMA), or a base station (NodeB, NB) in a wideband code division multiple access (WCDMA) system, or an evolved NodeB (eNB or eNodeB) in an LTE system, or a wireless controller in a cloud radio access network (CRAN) scenario, or the network device may be a relay station, an access point, an on-board device, a wearable device, a network device in a 5G network, or a network device in a future evolved PLMN network, etc., which is not limited in the embodiments of the present application. The network device may be a device in a wireless network, such as a radio access network (RAN) node that connects the user device 502 to the wireless network. At present, some examples of RAN nodes are: base station, next generation base station gNB, transmission reception point (TRP), evolved NodeB (eNB), home base station, baseband unit (BBU), or access point (AP) in WiFi system. In a network structure, the network equipment may include a centralized unit (CU) node, or a distributed unit (DU) node, or a RAN device including a CU node and a DU node. Among them, in the O-RAN system, CU can also be called O-CU, and DU can also be called O-DU.

[0195] Because the embodiments of the present application mainly involve access network devices, in the following text, unless otherwise specified, the network devices referred to are all access network devices. In the following text, a base station may be used to represent a network device and / or an access network device.

[0196] In the embodiment of the present application, the network device 501 may include a centralized unit (CU) and a distributed unit (DU). Specifically, the access network device may include one or more centralized units (CU) and a distributed unit (DU), and a DU may also be connected to multiple CUs.

[0197] As an example, the interface between CU and DU may be referred to as an F1 interface, wherein the control panel (CP) interface may be F1-C, and the user panel (UP) interface may be F1-U. CU and DU may be divided according to the protocol layers of the wireless network, for example, the functions of the PDCP layer and above protocol layers are set in the CU, and the functions of the protocol layers below the PDCP layer (such as the RLC layer and the MAC layer, etc.) are set in the DU.

[0198] It can be understood that the above-mentioned division of the processing functions of CU and DU according to the protocol layer is only an example, and it can also be divided in other ways, such as the functions of the protocol layer above the RLC layer are set in the CU, and the functions of the protocol layer and below the RLC layer are set in the DU. For example, the CU or DU can be divided into functions with more protocol layers, and the CU or DU can also be divided into partial processing functions with protocol layers. In one design, some functions of the RLC layer and the functions of the protocol layer above the RLC layer are set in the CU, and the remaining functions of the RLC layer and the functions of the protocol layer below the RLC layer are set in the DU. In another design, the functions of the CU or DU can also be divided according to the service type or other system requirements, for example, according to the delay, the functions whose processing time needs to meet the delay requirements are set in the DU, and the functions that do not need to meet the delay requirements are set in the CU. In another design, the CU may also have one or more functions of the core network. Exemplarily, the CU can be set on the network side for centralized management; the DU can have multiple radio frequency functions, or the radio frequency functions can be set remotely. The embodiments of the present application are not limited to this.

[0199] Exemplarily, the function of CU can be implemented by one entity, or it can also be implemented by different entities. For example, the function of CU is further divided, that is, the control plane and the user plane are separated and implemented through different entities, namely the control plane CU entity (i.e., CU-CP entity) and the user plane CU entity (i.e., CU-UP entity). The CU-CP entity and the CU-UP entity can be coupled with the DU to jointly complete the function of the RAN device. The interface between the CU-CP entity and the CU-UP entity can be an E1 interface, the interface between the CU-CP entity and the DU can be an F1-C interface, and the interface between the CU-UP entity and the DU can be an F1-U interface. Among them, one DU and one CU-UP can be connected to one CU-CP. Under the control of the same CU-CP, one DU can be connected to multiple CU-UPs, and one CU-UP can be connected to multiple DUs.

[0200] The user equipment 502 is an entity on the user side for receiving or transmitting signals, and is mainly used to realize the function of wireless communication with the network equipment 501.

[0201] For example, user equipment 502 can be an access terminal, a subscriber unit, a subscriber station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent, or a user device. The user equipment 502 may also be a mobile phone, a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a tablet computer (Pad), a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, an in-vehicle device, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, a wearable device (such as a smart watch, a smart bracelet, a pedometer, etc.), a terminal device in a 5G network, or a public land mobile communication network (public land mobile communication network) to be evolved in the future. The user equipment 502 may be a terminal device in a local mobile network (PLMN), etc., which is not limited in the embodiments of the present application. The user equipment 502 may be deployed on land, including indoors or outdoors, handheld, wearable or vehicle-mounted, or may be deployed on the water (such as a ship, etc.), or may be deployed in the air (for example, on an airplane, a balloon, and a satellite, etc.). In the embodiments of the present application, the user equipment 502 may be a legacy UE, or may be an RB-level partial frequency hopping (RPFS) UE that supports SRS coverage and capacity enhancement, or may be other UEs. The present application does not limit the type of user equipment 502. Among them, legacy UE refers to a user equipment that supports the existing mechanism, for example, a user equipment that supports release-15 and release-16.

[0202] In an embodiment of the present application, user equipment 502 or network equipment 501 includes a hardware layer, an operating system layer running on the hardware layer, and an application layer running on the operating system layer. The hardware layer includes hardware such as a central processing unit (CPU), a memory management unit (MMU), and a memory (also called main memory). The operating system can be any one or more computer operating systems that implement business processing through a process, such as a Linux operating system, a Unix operating system, an Android operating system, an iOS operating system, or a windows operating system. The application layer includes applications such as a browser, an address book, a word processing software, and an instant messaging software. In addition, the embodiment of the present application does not specifically limit the specific structure of the execution subject of the method provided in the embodiment of the present application, as long as it can communicate according to the method provided in the embodiment of the present application by running a program that records the code of the method provided in the embodiment of the present application, for example, the execution subject of the method provided in the embodiment of the present application can be a user device 502 or a network device 501, or a functional module in the user device 502 or the network device 501 that can call a program and execute the program.

[0203] It should be noted that Figure 5A The number and type of user equipment 502 included in the network architecture shown is only an example, and the embodiments of the present application are not limited thereto. For example, more or fewer user equipment 502 communicating with the network device 501 may also be included, which are not described one by one in the drawings for the sake of simplicity.

[0204] In addition, in Figure 5A In the network architecture shown, although the network device 501 and the user device 502 are shown, the application scenario may not be limited to including the network device 501 and the user device 502, for example, it may also include a core network device or a device for carrying a virtualized network function, wherein the core network device communicates with the user device 502 through the network device 501, and an exemplary embodiment may be referred to below Figure 5B The application scenario shown.

[0205] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: global system of mobile communication (GSM) system, code division multiple access (CDMA) system, wideband code division multiple access (WCDMA) system, general packet radio service (GPRS), long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), universal mobile telecommunication system (UMTS), worldwide interoperability for microwave access (WiMAX) communication system, fifth generation (5G) system or new radio (NR) and future communication systems, etc., without limitation here.

[0206] Taking the 5G system in the embodiment of the present application as an example, an application scenario of an MBS service in the embodiment of the present application is introduced.

[0207] See also Figure 5B , Figure 5B 1 is a schematic diagram of an application scenario exemplarily provided in an embodiment of the present application. The application scenario includes a data server, a CN, a RAN and at least one UE.

[0208] Among them, the data server can be the provider of MBS services, such as application servers corresponding to live broadcast services, public safety services, and batch software update services; CN, access network equipment and user equipment are network elements in the network architecture of 5G networks.

[0209] Figure 5BThe example shows that CN includes 5G cores corresponding to two operators, namely 5GC PLMNA corresponding to operator A and 5GC PLMNB corresponding to operator B; RAN is a shared DU architecture only, RAN includes Shared gNB-DU, gNB-CU PLMNA corresponding to operator A, and gNB-CU PLMNAB corresponding to operator B; at least one UE includes n UEs, namely UE1, UE2 to UEn, where n is a positive integer greater than 2. In the embodiment of the present application, Shared gNB-DU can be called the first node, gNB-CU PLMNA corresponding to operator A can be called the second node, and gNB-CU PLMNAB corresponding to operator B can be called the third node.

[0210] Taking the MBS service as the first service as an example, the data server can send the service data of the first service to the gNB-CU PLMNA and the gNB-CUPLMNAB. Specifically, the data server can establish a multicast broadcast service session of the first service (referred to as the first session) with the gNB-CU PLMNA, and the data server can establish a multicast broadcast service session of the first service (referred to as the second session) with the gNB-CU PLMNAB; the data server sends the service data of the first service to the gNB-CU PLMNA through the first session, and the data server sends the service data of the first service through the second session.

[0211] Furthermore, the gNB-CU PLMNA may process the service data of the first service to obtain a first data packet; the gNB-CU PLMNAB may process the service data of the first service to obtain a second data packet. For the convenience of description, the data packet obtained after the gNB-CU PLMNA processes the service data of the first service is referred to as the first data packet; the data packet obtained after the gNB-CU PLMNAB processes the service data of the first service is referred to as the second data packet.

[0212] The processing of the service data of the first service by the gNB-CU PLMNA and the gNB-CU PLMNAB includes configuring the PDCP SN of the data packet of the first service. Since different CUs may have different rules for PDCP SN, that is, the PDCP SN configured by the gNB-CU PLMNA and the gNB-CU PLMNAB for the same data packet of the first service may be different.

[0213] Assuming that the PDCP configuration for the first service sent by gNB-CU PLMNA and gNB-CU PLMNB to the Shared gNB-DU is the same, the Shared gNB-DU uses the same MRB configuration to transmit the service data of the first service. Furthermore, gNB-CU PLMNA can send the first data packet to the Shared gNB-DU, and gNB-CU PLMNB can send the second data packet to the Shared gNB-DU. The Shared gNB-DU sends the first data packet or the second data packet to at least one UE based on the same MRB configuration.

[0214] It should be noted that Figure 5A The network device 501 in the example may be Figure 5B RAN in Figure 5A The user equipment 502 in the example may be Figure 5B at least one UE in .

[0215] Among them, the communication between the access network device and the user equipment follows a certain protocol layer structure, for example, the control plane protocol layer structure may include a radio resource control (RRC) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, a media access control (MAC) layer and a physical layer (PHY); the user plane protocol layer structure may include a PDCP layer, an RLC layer, a MAC layer and a physical layer. In a possible implementation, a service data adaptation protocol (SDAP) layer may also be included above the PDCP layer.

[0216] For MBS services, the transmission direction of MBS service data is from the access network device to the user device. For example, the MBS service data can be live broadcast service data, public safety service data, or batch software update service data, etc., which are not limited here.

[0217] In some other embodiments of the present application, in the above application scenario, the third node may also be connected to a non-shared DU, specifically, the CU-CP of the third node may be connected to the DU. The data sent by the third node to the first node may be sent to the DU synchronously.

[0218] In combination with the above network architecture, a communication method for a multicast broadcast service provided in an embodiment of the present application is described below.

[0219] See also Figure 6 , Figure 6 It is a flow chart of a communication method for a multicast broadcast service provided in an embodiment of the present application. The functions performed by the user equipment in this embodiment can also be performed by a module (e.g., a chip) in the user equipment, and the functions performed by the network equipment in this application can also be performed by a module (e.g., a chip) in the network equipment.

[0220] In the embodiment of the present application, the first node can be Figure 5A The shared DU in Figure 5B The second node can be SharedgNB-DU in Figure 5A The first CU in can also be Figure 5B The third node can be gNB-CU PLMNA in Figure 5A The second CU in can also be Figure 5B gNB-CU PLMNB in; the user equipment can be Figure 5A The user equipment 502 in Figure 5B For a detailed description of the first node, the second node, the third node and the user equipment, please refer to the relevant content above, which will not be repeated here.

[0221] like Figure 6 As shown, the communication method of the multicast broadcast service may include the following steps:

[0222] Step S601: the second node sends a first data convergence protocol PDCP sequence number to the first node, where the first PDCP sequence number is the PDCP sequence number of a first data packet sent by the second node at a first moment.

[0223] Correspondingly, the first node receives the first PDCP sequence number from the second node.

[0224] The first data packet may be service data of an MBS service, and the MBS service may be a live broadcast service, a public safety service, a batch software update service, or the like.

[0225] by Figure 5BFor example, the second node may be the CU corresponding to the core network (i.e., 5GCPLMNA) of operator A. After receiving the service data of the MBS service from the data server, 5GCPLMNA processes the service data; then, the processed first data packet is sent to the second node; the second node may process the first data packet, such as configuring the PDCP sequence number of the first data packet; then, the second node may send the configured first data packet to the first node, and the first node sends the first data packet to the user equipment. Among them, the PDCP sequence number of the first data packet may be specifically configured by the user plane of the second node. For the convenience of description, the user plane of the second node is referred to as CU-UP1 in the embodiment of the present application.

[0226] In some embodiments, before executing the above step S601, the first node receives a first data packet from the second node, and the first PDCP sequence number of the first data packet belongs to the receiving window of the PDCP layer of the UE. Then, the first node sends the first data packet to the user equipment.

[0227] In some other embodiments, the first node sends a first request to the second node, where the first request is used to request a first PDCP sequence number, and then the second node sends a first Data Convergence Protocol PDCP sequence number to the first node.

[0228] Step S602: The first node sends the first PDCP sequence number to the third node.

[0229] Correspondingly, the third node receives the first PDCP sequence number from the first node.

[0230] Step S603: the third node sends a second data packet to the first node, the PDCP sequence number of the second data packet belongs to the receiving window of the PDCP layer of the user equipment UE; the first data packet and the second data packet are associated with the first multicast broadcast service.

[0231] Correspondingly, the first node receives the second data packet from the second node. The first multicast broadcast service (also referred to as the first MBS service) may be a live broadcast service, a public safety service, a batch software update service, and the like.

[0232] In some embodiments, after receiving the first PDCP sequence number sent from the first node, the third node may configure the PDCP sequence number of the second data packet based on the first PDCP sequence number, and then send the configured second data packet to the first node.

[0233] Exemplarily, the third node may configure the second data packet currently being processed as the next PDCP sequence number of the first PDCP sequence number. The embodiment of the present application does not limit the numbering rule of the PDCP sequence number, that is, the next PDCP sequence number of the first PDCP sequence number may be the next value of the numerical value of the first PDCP sequence number, such as if the first PDCP sequence number is 50, and the next PDCP sequence number of the first PDCP sequence number is 51; the next PDCP sequence number of the first PDCP sequence number may not be the next value of the numerical value of the first PDCP sequence number, which is determined by the numbering rule of the PDCP sequence number. In the embodiment of the present application, the numbering rules for the PDCP sequence numbers of the second node and the third node may be the same or different.

[0234] Exemplarily, assuming that the moment when the third node receives the first PDCP sequence number is moment t, the third node can configure the data packet received from the second core network or the second data packet sent to the first node after moment t based on the first PDCP sequence number and the window length of the receiving window of the PDCP layer. For example, if the first PDCP sequence number is 50 and the window length of the receiving window of the PDCP layer is 100, then the PDCP sequence number of the second data packet can be 51 to 150, and 51 to 150 all belong to the receiving window of the PDCP layer of the current UE. The embodiment of the present application does not limit the window length of the receiving window of the PDCP layer.

[0235] In one implementation, the PDCP window length corresponding to the first PDCP SN may be obtained from the SN length in the PDCP configuration. For example, if the PDCP SN length is 12 bits, the receiving window length is 2. 12-1 . Assume that the third node includes a user plane CU-UP2 and a control plane CU-CP2, CU-UP2 judges the PDCP SN of the current second data packet (referred to as the second PDCP SN) according to the first PDCP SN and the PDCP window corresponding to the first PDCP SN. If the second PDCP SN is within the above-mentioned PDCP receiving window, the second PDCP SN is not modified; if the second PDCP SN is outside the above-mentioned PDCP receiving window, the second PDCP SN is modified. The embodiment of the present application does not limit the method for modifying the PDCP SN, as long as the modified second PDCP SN is within the above-mentioned PDCP receiving window.

[0236] Step S604: the first node sends a second data packet to the user equipment.

[0237] Correspondingly, the UE receives the second data packet from the first node.

[0238] In some embodiments, before the first node sends the second data packet to the user equipment UE, the first node includes:

[0239] The first node receives a first message from a third node, where the first message is used to instruct the first node to use a data packet from the third node, and the first message is sent by the third node to the first node after receiving a first PDCP sequence number.

[0240] The following FIG. 7A to FIG. 7D For the above Figure 6 Step S601 and step S602 in FIG. 1 are described in detail. For the convenience of description, FIG. 7A to FIG. 7D In the figure, the user plane of the second node is represented as CU-UP1, and the control plane of the second node is represented as CU-CP1; the user plane of the third node is represented as CU-UP2, and the control plane of the third node is represented as CU-CP2; the first PDCP sequence number is represented as PDCP SN1.

[0241] Fig. 7A 1 is a schematic diagram of a second node obtaining a first PDCP sequence number provided by an embodiment of the present application. The second node includes a first user plane CU-UP1 of the second node and a first control plane CU-CP1 of the second node, and the third node includes a second user plane CU-UP2 of the third node and a second control plane CU-CP2 of the third node;

[0242] exist Fig. 7A In the illustrated embodiment, step S601 may specifically be: the first user plane CU-UP1 sends the first PDCP sequence number to the first control plane CU-CP1; further, the first control plane CU-CP1 sends the first PDCP sequence number to the first node, and accordingly, the first node receives the first PDCP sequence number from the first control plane CU-CP1.

[0243] For example, CU-CP1 can send a request message to CU-UP1, requesting CU-UP1 to provide the PDCP SN1 of the current broadcast session. It can be understood that since CU-UP is responsible for data transmission on the user plane, CU-UP can obtain the PDCP SN number through the currently transmitted data packet number. CU-CP is responsible for control plane transmission and does not know the PDCP SN number, so it is necessary to send a request message to CU-UP, requesting CU-UP to send the currently transmitted PDCP SN number to CU-CP. Furthermore, CU-CP1 sends a request message to the shared DU, and the request message carries PDCP SN1.

[0244] Step S602 may specifically be: the first node sends the first PDCP sequence number to the second control plane CU-CP2; the second control plane CU-CP2 sends the first PDCP sequence number to the second user plane CU-UP2, and the first PDCP sequence number is used for the second user plane CU-UP2 to configure the PDCP sequence number of the second data packet.

[0245] For example, the first node (such as Shared DU) can send a first request message to CU-CP2, and the first request message is used to request the establishment of an F1 tunnel; then based on the F1 tunnel, a second request message is sent to CU-CP2, and the second request message is used to request to change the configuration message of the PDCP SN, and the request message carries the above-mentioned PDCP SN1. It can be understood that since CU-UP2 is currently required to send data to the shared DU, but there is no tunnel between the two, the shared DU needs to send a request message to CU-CP2 to request the establishment of an F1 tunnel between the two. Furthermore, CU-CP2 can send a modification request message to CU-UP2, carrying PDCP SN1 at the same time. CU-UP2 modifies the PDCP sequence number (PDCPSN2) of the currently processed data packet to PDCP SN1, and sends the modified data packet to CU-CP2; CU-CP2 sends the modified data packet to the shared DU.

[0246] The following is a detailed introduction from S11 to S18. Fig. 7A The corresponding communication method of the multicast broadcast service.

[0247] S11: Optionally, the shared DU may send a first request message to CU-CP1, where the first request message is used to request CU-CP1 to provide a PDCP SN number of the current broadcast session, which is recorded as a first PDCP SN.

[0248] S12: CU-CP1 sends a second request message to CU-UP1, where the second request message is used to request CU-UP1 to provide a first PDCP SN of the current broadcast session.

[0249] In one implementation, since the transmission of PDCP data packets is the responsibility of CU-UP, CU-UP can know the PDCP SN number of the data packet currently being transmitted. CU-CP is only responsible for control plane transmission and is not sensitive to the PDCP SN number of the user plane data packet. Therefore, CU-CP needs to send a request message to CU-UP, requesting CU-UP to send the PDCP SN number of the data packet of the currently transmitted broadcast session to CU-CP.

[0250] S13: CU-CP1 sends a first response message to the shared DU, carrying the first PDCP SN.

[0251] S14: The Shared DU sends a third request message to CU-CP2, carrying the first PDCP SN.

[0252] In one implementation, before using CU-UP2 to send data to shared DU, it is necessary to establish a user plane tunnel between CU-UP2 and sharedDU. It should be noted that whether to establish a tunnel is not limited in the embodiment of the present application. For example, if there is no user plane tunnel between CU-UP2 and shared DU, Shared DU can send a request message to CU-CP2, and the request message is used to request the establishment of a tunnel and carry the above-mentioned first PDCP SN; if there is a user plane tunnel between CU-UP2 and shared DU, Shared DU can send a request message to CU-CP2, and the request message is used to carry the first PDCP SN.

[0253] S15: CU-CP2 sends a modification request message to CU-UP2, carrying the first PDCP SN.

[0254] In one implementation, if CU-UP2 is also sending a data packet of the same broadcast service to DU, the PDCP SN of the current data packet is recorded as the second PDCP SN. Since the second PDCP SN may not be within the PDCP window for receiving the first PDCP SN, CU-CP2 needs to send a modification request message to CU-UP2 to modify the PDCPSN of the same broadcast service transmitted on CU-UP2.

[0255] S16: CU-UP2 modifies the current second PDCP SN according to the first PDCP SN and the PDCP window corresponding to the received first PDCP SN.

[0256] In one implementation, the PDCP window length corresponding to the first PDCP SN may be obtained from the SN length in the PDCP configuration. For example, if the PDCP SN length is 12 bits, the receiving window length is 2. 12-1 . CU-UP2 determines the second PDCP SN according to the first PDCP SN and the PDCP window corresponding to the first PDCP SN. If the second PDCP SN is within the above PDCP receiving window, the second PDCP SN is not modified; if the second PDCP SN is outside the above PDCP receiving window, the second PDCP SN is modified. The embodiment of the present application does not limit the method for modifying the PDCP SN, as long as the modified second PDCP SN is within the above PDCP receiving window.

[0257] S17: CU-UP2 sends a response message of the modification request to CU-CP2, where the response message is used to indicate that the modification of the second PDCP SN has been completed.

[0258] S18: CU-CP2 sends a response message corresponding to the third request message to the shared DU, where the response message is used to indicate that the tunnel has been established or the data source has been switched to CU-UP2.

[0259] The embodiment of the present application modifies the second PDCP SN through the interaction of the control plane, so that the UE will not experience packet loss when using the same MRB to receive the same broadcast service. In addition, through the interaction of control signaling, reliability is better.

[0260] Figure 7B is another schematic diagram of a second node acquiring a first PDCP sequence number provided by an embodiment of the present application. The second node includes a first user plane CU-UP1 of the second node, and the third node includes a second user plane CU-UP2 of the third node;

[0261] exist Figure 7B In the illustrated embodiment, step S601 may specifically be: the first user plane CU-UP1 sends the first PDCP sequence number to the first node, and correspondingly, the first node receives the first PDCP sequence number from the first user plane CU-UP1.

[0262] For example, the first node (such as shared DU) receives downlink data transmission of CU-UP1, namely, DL USER DATA, which includes PDCP SN1.

[0263] Step S602 may specifically be: the first node sends the first PDCP sequence number to the second user plane CU-UP2, and accordingly, the second user plane CU-UP2 receives the first PDCP sequence number from the first node, and the first PDCP sequence number is used for the second user plane CU-UP2 to configure the PDCP sequence number of the second data packet.

[0264] For example, the shared DU sends a request message to CU-UP2 to request the establishment of an F1-U tunnel between the two. In one implementation, the shared DU needs to send a tunnel establishment request message to CU-UP2 to request the establishment of an F1-U tunnel between the two, so as to receive data sent by CU-UP2. The shared DU uses DL DATA DELIVERY STATUS (PDU Type 1) to inform CU-UP2 of PDCP SN1, and CU-UP2 modifies PDCP SN2 to PDCP SN1; CU-UP2 uses DL USER DATA (PDUType 0) to inform the shared DU of the modified PDCP SN1.

[0265] The following is a detailed introduction through S21 to S24. Figure 7B The corresponding communication method of the multicast broadcast service.

[0266] S21: the shared DU receives downlink data transmission of CU-UP1, namely, DL USER DATA (PDU Type 0), wherein the header of the data packet (namely, the first data packet) includes the first PDCP SN;

[0267] S22: Optionally, the shared DU sends a request message to CU-CP2 to request to establish an F1-U tunnel between the two.

[0268] In one implementation, if there is no data transmission tunnel between the shared DU and CU-UP2, the shared DU needs to send a tunnel establishment request message to CU-CP2, requesting to establish an F1-U tunnel between the shared DU and CU-UP2, so as to receive data sent by CU-UP2.

[0269] S23: The shared DU sends a DL DATA DELIVERY STATUS (PDU Type 1) to CU-UP2, carrying the first PDCP SN in its header;

[0270] In one implementation, DL DATA DELIVERY STATUS is feedback on DL USER DATA, that is, sharedDU feeds back the sending status of the data packet after receiving the data packet sent by CU-UP2. Therefore, whether there is already a user plane tunnel between shared DU and CU-UP2 (CU-UP2 has been sending data to shared DU), or there is no user plane tunnel between shared DU and CU-UP2 (tunnel establishment process using S22), CU-UP2 will send DL USER DATA to shared DU after the tunnel is established, which carries the second PDCP SN. When shared DU receives the data packet sent by CU-UP2, it will send DL DATA DELIVERY STATUS to CU-UP2, which, in addition to the second PDCP SN, should also carry the first PDCP SN to indicate the data packet number received by the current shared DU from CU-UP1.

[0271] S24: CU-UP2 modifies the current second PDCP SN according to the first PDCP SN and the PDCP window corresponding to the received first PDCP SN;

[0272] In one implementation, the PDCP window length corresponding to the first PDCP SN may be obtained from the SN length in the PDCP configuration. For example, if the PDCP SN length is 12 bits, the receiving window length is 2. 12-1. CU-UP2 determines the second PDCP SN according to the first PDCP SN and the PDCP window corresponding to the first PDCP SN. If the second PDCP SN is within the above PDCP receiving window, the second PDCP SN is not modified; if the second PDCP SN is outside the above PDCP receiving window, the second PDCP SN is modified. The embodiment of the present application does not limit the method for modifying the PDCP SN, as long as the modified second PDCP SN is within the above PDCP receiving window.

[0273] The embodiment of the present application modifies the second PDCP SN by using the interaction of the user plane, so that the UE will not experience packet loss when using the same MRB to receive the same broadcast service. Fig. 7A Compared with the embodiment of the present application, the embodiment of the present application can save the signaling overhead of the user plane and is simpler to implement.

[0274] Figure 7C It is a schematic diagram of another second node obtaining a first PDCP sequence number provided by an embodiment of the present application. The second node includes a first user plane CU-UP1 of the second node and a first control plane CU-CP1 of the second node, and the third node includes a second user plane CU-UP2 of the third node;

[0275] exist Figure 7C In the illustrated embodiment, step S601 may specifically be: the first user plane CU-UP1 sends the first PDCP sequence number to the first control plane CU-CP1; further, the first control plane CU-CP1 sends the first PDCP sequence number to the first node, and accordingly, the first node receives the first PDCP sequence number from the first control plane CU-CP1.

[0276] Step S602 may specifically be: the first node sends the first PDCP sequence number to the second user plane CU-UP2, and accordingly, the second user plane CU-UP2 receives the first PDCP sequence number from the first node, and the first PDCP sequence number is used for the second user plane CU-UP2 to configure the PDCP sequence number of the second data packet.

[0277] Fig.7D It is a schematic diagram of a second node obtaining a first PDCP sequence number provided by an embodiment of the present application. The second node includes a first user plane CU-UP1 of the second node, and the third node includes a second user plane CU-UP2 of the third node and a second control plane CU-CP2 of the third node;

[0278] exist Fig.7DIn the illustrated embodiment, step S601 may specifically be: the first user plane CU-UP1 sends the first PDCP sequence number to the first node, and correspondingly, the first node receives the first PDCP sequence number from the first user plane CU-UP1.

[0279] Step S602 may specifically be: the first node sends the first PDCP sequence number to the second control plane CU-CP2; the second control plane CU-CP2 sends the first PDCP sequence number to the second user plane CU-UP2, and the first PDCP sequence number is used for the second user plane CU-UP2 to configure the PDCP sequence number of the second data packet.

[0280] Understandably, Figure 7C and Fig.7D The illustrated embodiment is an embodiment in which the interaction modes of the control plane and the user plane are combined with each other. This method can save control plane signaling and ensure stability to a certain extent.

[0281] The following is an example, combined with Figure 5B The scene, through Figure 8 The embodiment of the above Figure 6 The method is described in detail.

[0282] Figure 8 1 is a flow chart of another communication method for a multicast broadcast service provided by an embodiment of the present application. The communication method for a multicast broadcast service may include the following steps:

[0283] Phase 1: The data server sends service data of the first service to the user equipment through the first core network, the second node and the first node.

[0284] Step S1: The data server sends service data of a first service to a first core network.

[0285] Step S2: the first core network sends a first data packet of the first service to the second node; the first data packet is obtained based on service data of the first service.

[0286] The first core network and the second node may belong to the same operator.

[0287] In some embodiments, the second node configures the PDCP configuration of the broadcast MCCH, and then sends it to the first node via a message (such as BROADCAST CONTEXT SETUP REQUEST), where the message carries the above PDCP configuration.

[0288] Step S3: the second node sends a first data packet to the first node, the first data packet including a sequence number configured by the second node; the PDCP sequence number of the first data packet is within a receiving window of the PDCP layer of the user equipment.

[0289] Step S4: the first node sends the first data packet to the user equipment.

[0290] In some embodiments, the first node currently uses a session between the second node and the data server to obtain service data, and the MRB configuration for communicating with the user equipment uses the PDCP configuration of the second node.

[0291] The second stage: the first node sends the PDCP sequence number of the first data packet currently sent by the second node (ie, the first PDCP sequence number) to the third node.

[0292] Step S5: the second node sends a first PDCP sequence number to the first node, where the first PDCP sequence number is the PDCP sequence number of the first data packet currently sent by the second node.

[0293] Correspondingly, the first node receives the first PDCP sequence number from the second node.

[0294] Step S6: The first node sends the first PDCP sequence number to the third node. The first PDCP sequence number is used by the third node to configure the PDCP sequence number of the second data packet, and the PDCP sequence number of the second data packet is within the receiving window of the PDCP layer of the user equipment.

[0295] Correspondingly, the third node receives the first PDCP sequence number from the first node.

[0296] Phase 3: The data server sends service data of the first service to the user equipment through the second core network, the third node and the first node.

[0297] Step S7: The data server sends the service data of the first service to the second core network.

[0298] Step S8: the second core network sends a second data packet of the first service to the third node; the second data packet is obtained based on the service data of the first service.

[0299] The second core network and the third node may belong to the same operator.

[0300] In some embodiments, the PDCP configuration of the broadcast MCCH is configured by the third node, and then sent to the first node via a message (such as BROADCAST CONTEXT SETUP REQUEST), where the message carries the above PDCP configuration.

[0301] Step S9: the third node sends a second data packet to the first node, where the second data packet includes a sequence number configured by the third node; the PDCP sequence number of the second data packet is within the receiving window of the PDCP layer of the user equipment.

[0302] Step S10: The first node sends a second data packet to the UE.

[0303] Correspondingly, the UE receives the second data packet from the first node.

[0304] In some embodiments, the first node adopts a session between a third node and a data server to obtain service data, and the MRB configuration for communicating with the user equipment may adopt the PDCP configuration of the third node.

[0305] In the embodiment of the present application, since the PDCP configurations of the first node and the second node are the same, the user equipment is unaware when the first node adopts the PDCP configuration of the second node and the PDCP configuration of the third node, so that the user equipment does not modify the receiving window of its PDCP layer. In the embodiment of the present application, the PDCP sequence number of the first data packet currently sent by the second node is sent to the third node in the second stage, so that the third node can configure the PDCP sequence number of the second data packet within the receiving window of the PDCP layer of the user equipment. Then, even if the packet sending progress of the second node and the third node is different, when the first stage is transformed to the second stage, since the PDCP sequence number of the second data packet belongs to the receiving window of the PDCP layer of the user equipment, the user equipment can also successfully receive the second data packet in the third stage, and a large number of second data packets will not be discarded.

[0306] It should be noted that the above-mentioned process of the second node executing steps S1 to S3 and the process of the third node executing steps S7 to S9 can occur simultaneously. For example, the second node and the third node both send service data of the same service to the first node according to their own processing order; the service data sent by the first node to the user equipment can come from the second node or from the third node. For example, the first node uses the first data packet of the second node in the first stage, and uses the second data packet of the second node in the third stage.

[0307] See also Fig. 9A , Fig. 9A It is a flowchart of another communication method for multicast broadcast services provided in an embodiment of the present application. The functions performed by the user equipment in this embodiment can also be performed by a module (e.g., a chip) in the user equipment, and the functions performed by the network equipment in this application can also be performed by a module (e.g., a chip) in the network equipment.

[0308] In the embodiment of the present application, the first node can be Figure 5AThe shared DU in Figure 5B The second node can be SharedgNB-DU in Figure 5A The first CU in can also be Figure 5B The third node can be gNB-CU PLMNA in Figure 5A The second CU in can also be Figure 5B gNB-CU PLMNB in; the user equipment can be Figure 5A The user equipment 502 in Figure 5B For a detailed description of the first node, the second node, the third node and the user equipment, please refer to the relevant content above, which will not be repeated here.

[0309] like Fig. 9A As shown, the communication method of the multicast broadcast service may include the following steps:

[0310] Step S901: the first node sends a first data packet to a user equipment UE based on a first multicast data radio bearer MRB configuration; the first data packet is sent by the second node to the first node.

[0311] Correspondingly, the UE receives the first data packet sent by the first node.

[0312] Step S902: The first node sends a first message to the UE, where the first message includes parameter information configured by the second MRB.

[0313] In some embodiments, before the first node sends a first message to the UE, the first node receives a first request sent by the second node, the first request including a service identifier of the multicast broadcast service; the first request is used to request to release the multicast broadcast service session of the second node.

[0314] Optionally, the first request may further include parameter information configured by the second MRB.

[0315] The parameter information configured by the second MRB may include at least one of a data convergence protocol sequence number length (PDCP SNSize), a robust header compression (Robust Header Compression, ROHC), and a reordering timer (t-Reordering).

[0316] The service identifier of the multicast broadcast service includes at least one of a session identifier of the multicast broadcast service, a temporary multicast group identifier TMGI, and a service network identifier (Network Identifier, NID).

[0317] Fig. 9BThe schematic diagram of changing the PDCPSN size is exemplarily shown. Among them, TMGI 1 is used to indicate that it is the PDCP configuration corresponding to the broadcast session of the second node, and TMGI 2 is used to indicate that it is the PDCP configuration corresponding to the broadcast session of the third node. Before the first MCCH modification period, the PDCPSN size in the PDCP configuration of the second node and the third node is the same, both of which are 12 bits (bit). In the first MCCH modification period, the first node receives a first request sent by the second node, and the first request includes parameter information of the second MRB configuration (MRB configuration), including a new PDCP configuration, for example, the PDCPSN size is null (null is 18 bits).

[0318] Furthermore, the first node may set the PDCP SN size to null in the second MCCH modification period, and the second MCCH modification period may be the next period of the first MCCH modification period. For example, the first node (such as DU) receives a first request sent by the second node, and the first request includes parameter information of the second MRB configuration, including a new PDCP configuration, such as PDCP SN size is null (null is 18 bits); then, DU may broadcast the MRB configuration of 18-bit PDCP SN size over the air interface (i.e., the above-mentioned first message). After the UE sees that the MRB configuration has changed, it may delete the original 12-bit MRB configuration and establish an 18-bit MRB configuration.

[0319] Fig. 9B In the exemplary embodiment of the present application, the parameter information that is changed in the first MRB configuration and the second MRB configuration is an embodiment of the PDCPSN size. In other embodiments of the present application, the parameter information that is changed in the first MRB configuration and the second MRB configuration may be at least one of the PDCPSN size, ROHC and t-Reordering.

[0320] Step S903: after sending the first message, the first node sends a second message to the UE, where the second message includes parameter information of the first MRB configuration; the first MRB configuration is different from the second MRB configuration.

[0321] Among them, there is at least one configuration parameter different between the parameter information of the first MRB configuration and the parameter information of the second MRB configuration, and the configuration parameter includes at least one of the data convergence protocol sequence number length (PDCP SN Size), robust header compression (Robust Header Compression, ROHC), and reordering timer (t-Reordering).

[0322] Exemplarily, the first node may modify the MRB configuration in the third MCCH modification period, that is, modify the PDCP configuration to the original PDCP configuration. Specifically, the DU may broadcast the modified 12-bit MRB PDCP configuration (the above-mentioned second message) over the air interface. When the UE finds that the MRB configuration has changed, it may delete the 18-bit MRB and then rebuild the 12-bit MRB. In this way, the UE side deletes and rebuilds the MRB, thereby solving the problem of PDCP SN number jump.

[0323] Step S904: after sending the second message, the first node sends a second data packet to the user equipment based on the first MRB configuration, where the second data packet is sent from the third node to the first node; the first data packet and the second data packet belong to the same multicast broadcast service.

[0324] In some embodiments, the first node may receive the first request, and send the first message and the second message within three consecutive MCCH modification periods. For example, when the first node receives the first request within the first multicast control channel MCCH modification period, the first node sends the first message within the second MCCH modification period, and the second MCCH modification period is the next MCCH modification period of the first MCCH modification period; the first node sends the second message within the third MCCH modification period, and the third MCCH modification period is the next MCCH modification period of the second MCCH modification period.

[0325] In some other embodiments of the present application, the moment when the first node receives the first request and the moment when the first node sends the first message and the second message may not be within three consecutive MCCH modification periods, and the moment when the first node sends the first message and the second message may be within two consecutive MCCH modification periods. For example, when the moment when the first node sends the first message is within the fourth MCCH modification period, the moment when the first node sends the second message is within the fifth MCCH modification period, and the fifth MCCH modification period is the next MCCH modification period of the fourth MCCH modification period.

[0326] The key point in the embodiment of the present application lies in the interaction of the air interface, that is, the air interface signaling interaction between the base station and the UE. In the base station, the air interface signaling is sent by the DU, that is, the MCCH message is sent by the DU to the UE. When the MCCH message is updated (when the MRB configuration changes), the DU can send the updated MCCH message to the UE in the MCCH modification period. The embodiment of the present application deletes and rebuilds the MRB in the MCCH modification period through the above-mentioned first message and second message, so that the UE perceives that the MRB has changed and a new MRB has been rebuilt, which can solve the problem of packet loss when the first node switches from sending a first data packet to the UE to sending a second data packet in the same MRB.

[0327] The following is a detailed introduction through S31 to S33. Fig. 9A The corresponding communication method of the multicast broadcast service.

[0328] S31: Optionally, in the first MCCH modification period, the DU receives a broadcast session release request message sent by the CU, requesting to release TMGI 1.

[0329] In one implementation, the DU receives the MRB configurations of the CUs of multiple operators, and the CUs of the multiple operators include CU1 and CU2. The broadcast session of CU1 is identified by TMGI1, and the broadcast session of CU2 is identified by TMGI2. Although TMGI1 and TMGI2 are different broadcast sessions, the contents of the broadcast sessions are the same. The premise of this embodiment is that the MRB configurations of CU1 and CU2 have been coordinated into the same configuration, that is, the PDCPSN size, ROHC and t-Reordering configurations in the PDCP configuration are the same. The DU receives data packets sent by CU1 and CU2, but the DU chooses to use the data packets of CU1 and sends them to the UE over the air interface. In the first MCCH modification period and the time period before, the DU sends data packets to the UE based on the same configured MRB configuration, and the MRB here is recorded as the first MRB. Optionally, in the first MCCH modification period, the DU receives a broadcast session release request message from CU1, that is, the core network instructs the release of CU1's broadcast session TMGI1. At this time, CU2's broadcast session TMGI2 still exists on the DU.

[0330] S32: In the second MCCH modification period, the DU receives a message from CU2, which includes the configuration of the second MRB, and the configuration of the second MRB is different from the configuration of the first MRB.

[0331] In one implementation, in the second MCCH modification period, the DU receives the configuration information of the second MRB sent by CU2, and the PDCP configuration of the second MRB is different from the PDCP configuration of the first MRB. Since the PDCP configuration mainly includes three items (i.e., PDCPSNsize, ROHC, and t-Reordering), one or more of the PDCP configurations in the second MRB can be different from the PDCP configurations in the first MRB. For example, the PDCP SN length is changed from 12 bits of the first MRB PDCP SN to 18 bits of the second MRB PDCP SN. At this time, the DU will broadcast the MRB configuration of the 18-bit PDCP SN over the air interface. After the UE perceives that the MRB configuration has changed, it will delete the original 12-bit MRB configuration and establish a new MRB (with a PDCP SN length of 18 bits).

[0332] S32: In the third MCCH modification period, the DU receives a message from CU2, which includes the configuration of the first MRB.

[0333] In one implementation, in the third MCCH modification cycle, the DU receives the MRB PDCP configuration sent by CU2, which is the same as the PDCP configuration of the first MRB. Then, the DU broadcasts the modified 12-bit MRB PDCP configuration over the air interface. When the UE detects that the MRB configuration has changed, it deletes the 18-bit MRB and then rebuilds the 12-bit MRB. In this way, deleting and rebuilding the MRB on the UE side not only solves the PDCP SN number jump problem, but also allows the UE to successfully receive data packets.

[0334] In an embodiment of the present application, by modifying the configuration of the MRB in different MCCH modification periods, the UE is made aware of changes in the MRB. When the UE senses that the MRB configuration has changed, the old MRB is deleted and a new MRB is established. When the UE uses the new MRB, it receives data packets according to the new PDCP SN and receiving window, thereby solving the problem of PDCP SN number hopping, that is, the UE can always receive data packets (there is no problem of not being able to receive data packets for a period of time). This method uses the DU to send an updated MRB configuration method over the air interface, completely reuses the existing process, does not require modifications to the standard, and is relatively simple to implement.

[0335] The following is an example, combined with Figure 5B The scene, through Fig.10 The embodiment of the above Fig. 9A The method is described in detail.

[0336] Fig.10 FIG. 1 is a flow chart of another communication method for a multicast broadcast service provided in an embodiment of the present application. The communication method for a multicast broadcast service may include the following steps:

[0337] Phase 1: The data server sends service data of the first service to the user equipment through the first core network, the second node and the first node.

[0338] Step S1: The data server sends service data of a first service to a first core network.

[0339] Step S2: the first core network sends a first data packet of the first service to the second node; the first data packet is obtained based on service data of the first service.

[0340] The first core network and the second node may belong to the same operator.

[0341] In some embodiments, the second node configures the PDCP configuration of the broadcast MCCH, and then sends it to the first node via a message (such as BROADCAST CONTEXT SETUP REQUEST), where the message carries the above PDCP configuration.

[0342] Step S3: the second node sends a first data packet to the first node, the first data packet including a sequence number configured by the second node; the PDCP sequence number of the first data packet is within a receiving window of the PDCP layer of the user equipment.

[0343] Step S4: the first node sends the first data packet to the user equipment based on the first multicast data radio bearer MRB configuration.

[0344] In some embodiments, the first node currently uses a session between the second node and the data server to obtain service data, and the MRB configuration for communicating with the user equipment uses the PDCP configuration of the second node.

[0345] The second stage: the first node broadcasts the first message and the second message to enable the user equipment to reestablish the MRB.

[0346] Step S5: The second node sends a first request to the first node, where the first request includes parameter information configured by the second MRB.

[0347] Correspondingly, the first node receives the first request from the second node.

[0348] The first request includes a service identifier of the multicast broadcast service; and the first request is used to request to release the session of the multicast broadcast service of the second node.

[0349] Step S6: The first node sends a first message to the user equipment, where the first message includes parameter information configured by the second MRB.

[0350] Correspondingly, the user equipment receives the first message from the first node.

[0351] Step S7: the third node sends a second request to the first node, where the second request includes parameter information of the first MRB configuration; the first MRB configuration is different from the second MRB configuration.

[0352] Correspondingly, the first node receives the second request from the third node.

[0353] It should be noted that the second request may be sent by the third node to the first node in the first stage. For example, in the above S1, the core network also sends the service data of the first service to the second core network, and the second core network sends the data packet of the first service to the third node. Before the third node sends the data packet to the first node, the second request may be sent to the first node. The embodiment itself does not limit the order of processing the service data by the first core network and the second core network, and does not limit the order of processing the data packets of the same service by the second node and the third node.

[0354] Step S8: After sending the first message, the first node sends a second message to the user equipment, where the second message includes parameter information configured by the first MRB.

[0355] Correspondingly, the user equipment receives the second message from the first node.

[0356] Phase 3: The data server sends service data of the first service to the user equipment through the second core network, the third node and the first node.

[0357] Step S9: The data server sends the service data of the first service to the second core network.

[0358] Step S10: the second core network sends a second data packet of the first service to the third node; the second data packet is obtained based on the service data of the first service.

[0359] The second core network and the third node may belong to the same operator.

[0360] In some embodiments, the PDCP configuration of the broadcast MCCH is configured by the third node, and then sent to the first node via a message (such as BROADCAST CONTEXT SETUP REQUEST), where the message carries the above PDCP configuration.

[0361] Step S11: the third node sends the second data packet to the first node.

[0362] Step S12: The first node configures a first multicast data radio bearer MRB to send a second data packet to the UE.

[0363] Correspondingly, the UE receives the second data packet from the first node.

[0364] It should be noted that the above-mentioned process of the second node executing steps S1 to S3 and the process of the third node executing steps S7 to S9 can occur simultaneously. For example, the second node and the third node both send service data of the same service to the first node according to their own processing order; the service data sent by the first node to the user equipment can come from the second node or from the third node. For example, the first node uses the first data packet of the second node in the first stage, and uses the second data packet of the second node in the third stage.

[0365] The present application also provides a communication method for a multicast broadcast service. The functions performed by the user equipment in the embodiments of the present application may also be performed by a module (e.g., a chip) in the user equipment, and the functions performed by the network equipment in the present application may also be performed by a module (e.g., a chip) in the network equipment.

[0366] In the embodiment of the present application, the DU may be the first node mentioned above, and the first node may be Figure 5A The shared DU in Figure 5B CU1 may be the second node mentioned above, and the second node may be Figure 5A The first CU in can also be Figure 5B gNB-CU PLMNA in the gNB-CU PLMNA; CU2 may be the third node mentioned above, and the third node may be Figure 5A The second CU in can also be Figure 5B gNB-CU PLMNB in ​​the gNB-CU PLMNB; UE is the above user equipment, and the user equipment can be Figure 5A The user equipment 502 in Figure 5B For a detailed description of the first node, the second node, the third node and the user equipment, please refer to the relevant content above, which will not be repeated here.

[0367] The communication method of the multicast broadcast service may include some or all of the following steps:

[0368] S101: DU receives a broadcast session release request message sent by CU1, where the message is used to request the release of TMGI 1.

[0369] It should be noted that S101 is an optional step. S101 is an exemplary implementation of the embodiment of the present application for triggering the DU to execute the following step S102. In other embodiments of the present application, S102 may also be actively triggered by the DU or requested to be executed by other devices. The embodiment of the present application does not limit this.

[0370] In one implementation, the DU can receive MRB configurations of CUs of multiple operators, and the MRB configurations of CUs of multiple operators can be coordinated into the same configuration; the DU can receive data packets of the same multicast broadcast service sent by CUs of multiple operators; the DU can choose to use the data packets from one of the CUs and send the data packets from the CU to the UE based on the same configured MRB configuration.

[0371] Exemplarily, the CUs of multiple operators including CU1 and CU2 are used as an example for explanation. The broadcast session of CU1 is identified by TMGI1, and the broadcast session of CU2 is identified by TMGI2. Although TMGI1 and TMGI2 are different broadcast sessions, the content of the broadcast sessions is the same. For example, the broadcast session of CU1 and the broadcast session of CU2 are both used to transmit the service data of the same multicast broadcast service. Among them, the MRB configurations of CU1 and CU2 have been coordinated to be the same, such as the PDCP SN Size, ROHC, and t-Reordering configurations in the PDCP configuration are the same. The DU can receive data packets sent by CU1 and CU2. It is assumed that the DU chooses to use the data packet of CU1 and sends it to the UE over the air interface. In the first MCCH modification period and the previous time period, the DU sends data packets to the UE based on the same configured MRB configuration, and the MRB here is recorded as the first MRB.

[0372] Optionally, in the first MCCH modification period, the DU may receive a broadcast session release request message from CU1, that is, the core network instructs the release of the broadcast session TMGI1 of CU1. At this time, the broadcast session TMGI2 of CU2 still exists on the DU.

[0373] S102: When the DU decides to use the broadcast service data from CU2, the DU may send an MCCH message over the air interface. The MCCH message carries indication information. The indication information is used to indicate that the source of the broadcast service data has been changed to CU2.

[0374] In some embodiments, after receiving the above-mentioned broadcast session release request message sent by CU1, DU may decide to use the broadcast service data from CU2; further, DU may send an MCCH message over the air interface, and the MCCH message carries indication information, which is used to indicate that the source of the broadcast service data has been changed to CU2.

[0375] In one implementation, assuming that the DU decides to use the broadcast service data from CU2, the DU may carry an indication information in the MCCH message sent over the air interface, where the indication information is used to indicate that the source of the broadcast service data has been changed to CU2.

[0376] For example, in a displayed indication method, the explicit indication may be carrying 1 bit of information, and the 1 bit of information may be 1 or 0, where 1 indicates a change and 0 indicates no change. Then, the UE can determine through the above indication information that the data source of the broadcast service has changed. Even if the configuration of the MRB in the MCCH has not changed, the UE will re-establish the MRB, that is, the second MRB (the second MRB configuration is the same as the first MRB configuration); after rebuilding the second MRB, the data of CU2 is received, so that the PDCP SN number can be continuously received to avoid jumping. It should be noted that this indication method is an indication method provided as an example in the embodiments of the present application. In other embodiments of the present application, the DU may also send indication information to the UE through some implicit indication methods, and the embodiments of the present application are not limited to this.

[0377] In the embodiment of the present application, by adding indication information in the MCCH message sent by the DU over the air interface, the UE can quickly reestablish the MRB. The indication information is used to indicate that the data source of the multicast broadcast service has changed, for example, switching from the CU of operator A (PLMN A) (such as the above CU1) to the CU of operator B (PLMN B) (such as the above CU2).

[0378] See also Fig.11 , Fig.11 1 is a schematic diagram of the structure of a communication device for a multicast broadcast service provided in an embodiment of the present application. The communication device may be a network device or a module (eg, a chip) in a network device. Fig.11 As shown, the communication device 110 at least includes: a receiving unit 1101 and a sending unit 1102; wherein:

[0379] The receiving unit 1101 is configured to receive a first data convergence protocol PDCP sequence number from a second node, where the first PDCP sequence number is a PDCP sequence number of a first data packet sent by the second node at a first moment;

[0380] The sending unit 1102 is configured to send the first PDCP sequence number to a third node;

[0381] The receiving unit 1101 is configured to receive a second data packet from a third node, where a PDCP sequence number of the second data packet belongs to a receiving window of a PDCP layer of a user equipment UE;

[0382] The sending unit 1102 is configured to send a second data packet to the UE, where the first data packet and the second data packet are associated with a first multicast broadcast service.

[0383] As a possible implementation manner, the second node includes a first user plane of the second node and a first control plane of the second node; the receiving unit 1101 is specifically configured to:

[0384] A first PDCP sequence number is received from a first control plane; the first PDCP sequence number is obtained by the first control plane from a first user plane.

[0385] As a possible implementation manner, the third node includes a second user plane of the third node and a second control plane of the third node; the sending unit 1102 is specifically configured to:

[0386] The first PDCP sequence number is sent to the second control plane; the second control plane is used to send the first PDCP sequence number to the second user plane; the first PDCP sequence number is used for the second user plane to configure the PDCP sequence number of the second data packet.

[0387] As a possible implementation manner, the third node includes a second user plane of the third node; and a sending unit 1102 is specifically configured to:

[0388] The first PDCP sequence number is sent to the second user plane; the first PDCP sequence number is used for configuring the PDCP sequence number of the second data packet on the second user plane.

[0389] As a possible implementation manner, the second node includes a first user plane of the second node; a receiving unit 1101, specifically configured to:

[0390] A first PDCP sequence number is received from a first user plane.

[0391] As a possible implementation manner, the third node includes a second user plane of the third node; and a sending unit 1102 is specifically configured to:

[0392] The first PDCP sequence number is sent to the second user plane; the first PDCP sequence number is used for configuring the PDCP sequence number of the second data packet on the second user plane.

[0393] As a possible implementation manner, the third node includes a second user plane of the third node and a second control plane of the third node; the sending unit 1102 is specifically configured to:

[0394] The first PDCP sequence number is sent to the second control plane; the second control plane is used to send the first PDCP sequence number to the second user plane; the first PDCP sequence number is used for the second user plane to configure the PDCP sequence number of the second data packet.

[0395] As a possible implementation manner, before sending the second data packet to the user equipment UE, the receiving unit 1101 is further configured to:

[0396] A first message is received from a third node, where the first message is used to indicate the use of a data packet from the third node, and the first message is sent by the third node after receiving a first PDCP sequence number.

[0397] As a possible implementation manner, before receiving the first data convergence protocol PDCP sequence number from the second node, the sending unit 1102 is further configured to:

[0398] A first request is sent to the second node, where the first request is used to request a first PDCP sequence number.

[0399] As a possible implementation manner, before receiving the first data convergence protocol PDCP sequence number from the second node, the receiving unit 1101 is further configured to:

[0400] A first data packet is received from the second node, where a first PDCP sequence number of the first data packet is within a receiving window of a PDCP layer of the UE.

[0401] For a more detailed description of the receiving unit 1101 and the sending unit 1102, please refer to the above Figure 6 and Figure 8 The relevant description of the first node in the method embodiment shown is not repeated here.

[0402] See also Fig.12 , Fig.12 FIG. 1 is a schematic diagram of the structure of another communication device for multicast broadcast services provided in an embodiment of the present application. The communication device may be a network device or a module (eg, a chip) in a network device. Fig.12 As shown, the communication device 120 at least includes: a receiving unit 1201 and a sending unit 1202; wherein:

[0403] The receiving unit 1201 is configured to receive a first packet data convergence protocol PDCP sequence number from a first node, where the first PDCP sequence number is a PDCP sequence number of a first data packet sent by a second node at a first moment;

[0404] The sending unit 1202 is used to send a second data packet to the first node, and the PDCP sequence number of the second data packet belongs to the receiving window of the PDCP layer of the user equipment UE; the first data packet and the second data packet are associated with the first multicast broadcast service.

[0405] As a possible implementation manner, before sending the second data packet to the first node, the sending unit 1202 is further configured to:

[0406] A first message is sent to the first node, where the first message is used to instruct the first node to use a data packet from the communication device.

[0407] As a possible implementation manner, before sending the second data packet to the first node, the apparatus further includes a configuration unit 1203, where the configuration unit 1203 is configured to:

[0408] Based on the first PDCP sequence number, configure the PDCP sequence number of the second data packet.

[0409] For a more detailed description of the receiving unit 1201, the sending unit 1202 and the configuration unit 1203, please refer to the above Figure 6 and Figure 8 The relevant description of the third node in the method embodiment shown is not repeated here.

[0410] See also Fig.13 , Fig.13 FIG. 1 is a schematic diagram of the structure of another communication device for multicast broadcast services provided in an embodiment of the present application. The communication device may be a network device or a module (eg, a chip) in a network device. Fig.13 As shown, the communication device 130 at least includes: a sending unit 1301; wherein:

[0411] The sending unit 1301 is configured to send a first data convergence protocol PDCP sequence number to a first node, where the first PDCP sequence number is a PDCP sequence number of a first data packet sent by the sending unit at a first moment.

[0412] As a possible implementation manner, the apparatus further includes a receiving unit 1302, and the receiving unit 1302 is configured to:

[0413] A first request is received from a first node, where the first request is used to request a first PDCP sequence number.

[0414] For a more detailed description of the receiving unit 1302 and the sending unit 1301, please refer to the above Figure 6 and Figure 8 The relevant description of the second node in the method embodiment shown is not repeated here.

[0415] See also Fig.14 , Fig.14 FIG. 1 is a schematic diagram of the structure of another communication device for multicast broadcast services provided in an embodiment of the present application. The communication device may be a network device or a module (eg, a chip) in a network device. Fig.14 As shown, the communication device 140 at least includes: a sending unit 1401; wherein:

[0416] The sending unit 1401 is configured to send a first data packet to a user equipment UE based on a first multicast data radio bearer MRB configuration; the first data packet is sent by a second node to a communication device;

[0417] The sending unit 1401 is configured to send a first message to the UE, where the first message includes parameter information of the second MRB configuration; the first MRB configuration is different from the second MRB configuration;

[0418] The sending unit 1401 is configured to send a second message to the UE after sending the first message, where the second message includes parameter information configured by the first MRB;

[0419] The sending unit 1401 is used to send a second data packet to the UE based on the first MRB configuration after sending the second message, where the second data packet is sent by the third node to the communication device; the first data packet and the second data packet are associated with the first multicast broadcast service.

[0420] As a possible implementation manner, before sending the first message to the UE, the apparatus further includes a receiving unit 1402, where the receiving unit 1402 is configured to:

[0421] A first request sent by a second node is received, where the first request includes a service identifier of a multicast broadcast service; the first request is used to request to release a session of the multicast broadcast service of the second node.

[0422] As a possible implementation manner, the service identifier of the multicast broadcast service includes at least one of a session identifier of the multicast broadcast service, a temporary multicast group identifier TMGI, and a service network identifier NID.

[0423] As a possible implementation, at least one configuration parameter in the parameter information of the first MRB configuration is different from that in the parameter information of the second MRB configuration, and the configuration parameter includes at least one of a data convergence protocol sequence number length, robust header compression, and a reordering timer.

[0424] As a possible implementation manner, when the communication device receives the first request within the first multicast control channel MCCH modification period, the communication device sends the first message within the second MCCH modification period, and the second MCCH modification period is the next MCCH modification period of the first MCCH modification period;

[0425] The moment when the communication device sends the second message is within the third MCCH modification period, and the third MCCH modification period is the next MCCH modification period of the second MCCH modification period.

[0426] As a possible implementation, when the communication device sends the first message within the fourth MCCH modification period, the communication device sends the second message within the fifth MCCH modification period, and the fifth MCCH modification period is the next MCCH modification period of the fourth MCCH modification period.

[0427] For a more detailed description of the sending unit 1401 and the receiving unit 1402, please refer to the above Fig. 9A The relevant description of the second node in the method embodiment shown is not repeated here.

[0428] Based on the above network architecture, please refer to Fig.15 , Fig.15 FIG. 1 is a schematic diagram of the structure of another communication device for multicast broadcast services disclosed in an embodiment of the present application. Fig.15 As shown, the communication device for the multicast broadcast service may include a processor 1501, a memory 1502, a transceiver 1503, and a bus 1504. The memory 1502 may exist independently and may be connected to the processor 1501 via the bus 1504. The memory 1502 may also be integrated with the processor 1501. The bus 1504 is used to realize the connection between these components. In one case, Fig.15 As shown, the transceiver 1503 may include a transmitter 15031, a receiver 15032, and an antenna 15033. In another case, the transceiver 1503 may include a transmitter (i.e., an output interface) and a receiver (i.e., an input interface). The transmitter may include a transmitter and an antenna, and the receiver may include a receiver and an antenna.

[0429] The communication device for the multicast broadcast service may be a user equipment or a module in the user equipment. When the computer program instructions stored in the memory 1502 are executed, the processor 1501 may be used to execute the above embodiment, and the transceiver 1503 may be used to execute the operations performed by the receiving unit 1101 and the sending unit 1102 or the sending unit 1202 and the receiving unit 1201 in the above embodiment. The communication device for the multicast broadcast service may also be used to execute the above Figure 4-Figure 6 The various methods executed by the user equipment in the method embodiment are not described in detail.

[0430] The communication device for the multicast broadcast service may be a network device or a module in the network device. When the computer program instructions stored in the memory 1502 are executed, the processor 1501 may be used to execute the above embodiment, and the transceiver 1503 may be used to execute the operations performed by the receiving unit 1101 and the sending unit 1102, the receiving unit 1201 and the sending unit 1202, the receiving unit 1302 and the sending unit 1301, or the sending unit 1401 and the receiving unit 1402 in the above embodiment. The communication device for the multicast broadcast service may also be used to execute the above Figure 4-Figure 10 The various methods executed by the network device in the method embodiment are not described in detail.

[0431] Based on the above network architecture, please refer to Fig.16 , Fig.16 FIG. 1 is a schematic diagram of the structure of another communication device for multicast broadcast services disclosed in an embodiment of the present application. Fig.16As shown, the communication device of the multicast broadcast service may include an input interface 1601, a logic circuit 1602 and an output interface 1603. The input interface 1601 is connected to the output interface 1603 through the logic circuit 1602. Among them, the input interface 1601 is used to receive information from other communication devices of multicast broadcast services, and the output interface 1603 is used to output, schedule or send information to other communication devices of multicast broadcast services. The logic circuit 1602 is used to perform operations other than the operations of the input interface 1601 and the output interface 1603, such as implementing the functions implemented by the processor 1501 in the above embodiment. Among them, the communication device of the multicast broadcast service can be a user device (or a module in a user device), or it can be a network device (or a module in a network device). Among them, a more detailed description of the input interface 1601, the logic circuit 1602 and the output interface 1603 can be directly obtained by referring to the relevant description of the user device and the network device in the above method embodiment, and will not be repeated here.

[0432] The embodiment of the present application also discloses a computer-readable storage medium having instructions stored thereon, and when the instructions are executed, the method in the above method embodiment is executed.

[0433] The embodiment of the present application also discloses a computer program product including instructions, which, when executed, execute the method in the above method embodiment.

[0434] The present application also discloses a communication system, which may include a network device and a user device. For a detailed description, please refer to Figure 4-Figure 6 The communication method of the multicast broadcast service is shown.

[0435] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above description is only the specific implementation methods of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent substitutions, improvements, etc. made on the basis of the technical solutions of the present application should be included in the scope of protection of the present application.

Claims

1. A communication method for a multicast broadcast service, characterized in that: include: The first node receives a first data convergence protocol PDCP sequence number from the second node, where the first PDCP sequence number is the PDCP sequence number of a first data packet sent by the second node at a first moment; The first node sends the first PDCP sequence number to a third node; The first node receives a second data packet from the third node, where a PDCP sequence number of the second data packet belongs to a receiving window of a PDCP layer of a user equipment UE; The first node sends the second data packet to the UE, and the first data packet and the second data packet are associated with a first multicast broadcast service.

2. The method according to claim 1, characterized in that The second node includes a first user plane of the second node and a first control plane of the second node; The first node receiving a first data convergence protocol PDCP sequence number from the second node includes: The first node receives the first PDCP sequence number from the first control plane; The first PDCP sequence number is obtained by the first control plane from the first user plane.

3. The method according to claim 2, characterized in that The third node includes a second user plane of the third node and a second control plane of the third node; The first node sending the first PDCP sequence number to a third node includes: The first node sends the first PDCP sequence number to the second control plane; the second control plane is used to send the first PDCP sequence number to the second user plane; the first PDCP sequence number is used by the second user plane to configure the PDCP sequence number of the second data packet.

4. The method according to claim 2, characterized in that: The third node includes a second user plane of the third node; and the first node sends the first PDCP sequence number to the third node, including: The first node sends the first PDCP sequence number to the second user plane; the first PDCP sequence number is used by the second user plane to configure the PDCP sequence number of the second data packet.

5. The method according to claim 1, characterized in that: The second node includes a first user plane of the second node; the first node receives a first data convergence protocol PDCP sequence number from the second node, including: The first node receives the first PDCP sequence number from the first user plane.

6. The method according to claim 5, characterized in that The third node includes a second user plane of the third node; and the first node sends the first PDCP sequence number to the third node, including: The first node sends the first PDCP sequence number to the second user plane; the first PDCP sequence number is used by the second user plane to configure the PDCP sequence number of the second data packet.

7. The method according to claim 5, characterized in that The third node includes a second user plane of the third node and a second control plane of the third node; The first node sending the first PDCP sequence number to a third node includes: The first node sends the first PDCP sequence number to the second control plane; the second control plane is used to send the first PDCP sequence number to the second user plane; the first PDCP sequence number is used by the second user plane to configure the PDCP sequence number of the second data packet.

8. The method according to any one of claims 1 to 7, characterized in that: Before the first node sends the second data packet to the user equipment UE, the method includes: The first node receives a first message from the third node, where the first message is used to instruct the first node to use the data packet from the third node, and the first message is sent by the third node to the first node after receiving the first PDCP sequence number.

9. The method according to any one of claims 1 to 4, characterized in that: Before the first node receives the first data convergence protocol PDCP sequence number from the second node, the method further includes: The first node sends a first request to the second node, where the first request is used to request the first PDCP sequence number.

10. The method according to any one of claims 1 to 9, characterized in that: Before the first node receives the first data convergence protocol PDCP sequence number from the second node, the method further includes: The first node receives a first data packet from the second node, and a first PDCP sequence number of the first data packet belongs to a receiving window of a PDCP layer of the UE.

11. A communication method for a multicast broadcast service, characterized in that: include: The third node receives a first packet data convergence protocol PDCP sequence number from the first node, where the first PDCP sequence number is the PDCP sequence number of a first data packet sent by the second node at a first moment; The third node sends a second data packet to the first node, and the PDCP sequence number of the second data packet belongs to the receiving window of the PDCP layer of the user equipment UE; the first data packet and the second data packet are associated with a first multicast broadcast service.

12. The method according to claim 11, characterized in that Before the third node sends the second data packet to the first node, the method further includes: The third node sends a first message to the first node, where the first message is used to instruct the first node to use a data packet from the third node.

13. The method according to claim 11 or 12, characterized in that: Before the third node sends the second data packet to the first node, the method further includes: The third node configures the PDCP sequence number of the second data packet based on the first PDCP sequence number.

14. A communication method for a multicast broadcast service, characterized in that: include: The second node sends a first data convergence protocol PDCP sequence number to the first node, where the first PDCP sequence number is the PDCP sequence number of a first data packet sent by the second node at a first moment.

15. The method according to claim 14, characterized in that The method further comprises: The second node receives a first request from the first node, where the first request is used to request the first PDCP sequence number.

16. A communication method for a multicast broadcast service, characterized in that: The method comprises: The first node sends a first data packet to a user equipment UE based on a first multicast data radio bearer MRB configuration; the first data packet is sent by the second node to the first node; The first node sends a first message to the UE, where the first message includes parameter information of a second MRB configuration; the first MRB configuration is different from the second MRB configuration; After sending the first message, the first node sends a second message to the UE, where the second message includes parameter information configured by the first MRB; After sending the second message, the first node sends a second data packet to the UE based on the first MRB configuration, where the second data packet is sent from a third node to the first node; the first data packet and the second data packet are associated with a first multicast broadcast service.

17. The method according to claim 16, characterized in that Before the first node sends the first message to the UE, the method further includes: The first node receives a first request sent by the second node, where the first request includes a service identifier of the multicast broadcast service; and the first request is used to request to release a session of the multicast broadcast service of the second node.

18. The method according to claim 17, characterized in that The service identifier of the multicast broadcast service includes at least one of a session identifier of the multicast broadcast service, a temporary multicast group identifier TMGI and a service network identifier NID.

19. The method according to claims 16 to 18, characterized in that There is at least one configuration parameter different between the parameter information of the first MRB configuration and the parameter information of the second MRB configuration, and the configuration parameter includes at least one of a data convergence protocol sequence number length, robust header compression, and a reordering timer.

20. The method according to claims 16 to 19, characterized in that When the moment when the first node receives the first request is within a first multicast control channel MCCH modification period, the moment when the first node sends the first message is within a second MCCH modification period, and the second MCCH modification period is a next MCCH modification period of the first MCCH modification period; The moment when the first node sends the second message is within a third MCCH modification period, and the third MCCH modification period is the next MCCH modification period of the second MCCH modification period.

21. The method according to claims 16 to 19, characterized in that When the moment when the first node sends the first message is within the fourth MCCH modification period, the moment when the first node sends the second message is within the fifth MCCH modification period, and the fifth MCCH modification period is the next MCCH modification period of the fourth MCCH modification period.

22. A communication device for multicast broadcast service, characterized in that: The device comprises: A receiving unit, configured to receive a first data convergence protocol PDCP sequence number from a second node, where the first PDCP sequence number is a PDCP sequence number of a first data packet sent by the second node at a first moment; a sending unit, configured to send the first PDCP sequence number to a third node; The receiving unit is configured to receive a second data packet from the third node, wherein the PDCP sequence number of the second data packet belongs to a receiving window of a PDCP layer of a user equipment UE; The sending unit is used to send the second data packet to the UE, and the first data packet and the second data packet are associated with a first multicast broadcast service.

23. The communication device according to claim 22, characterized in that: The second node includes a first user plane of the second node and a first control plane of the second node; the receiving unit is specifically configured to: Receive the first PDCP sequence number from the first control plane; the first PDCP sequence number is obtained by the first control plane from the first user plane.

24. The communication device according to claim 23, characterized in that The third node includes a second user plane of the third node and a second control plane of the third node; the sending unit is specifically configured to: The first PDCP sequence number is sent to the second control plane; the second control plane is used to send the first PDCP sequence number to the second user plane; the first PDCP sequence number is used by the second user plane to configure the PDCP sequence number of the second data packet.

25. The communication device according to claim 23, characterized in that The third node includes a second user plane of the third node; the sending unit is specifically configured to: The first PDCP sequence number is sent to the second user plane; the first PDCP sequence number is used by the second user plane to configure the PDCP sequence number of the second data packet.

26. The communication device according to claim 22, characterized in that The second node includes a first user plane of the second node; the receiving unit is specifically configured to: Receive the first PDCP sequence number from the first user plane.

27. The communication device according to claim 26, characterized in that The third node includes a second user plane of the third node; the sending unit is specifically configured to: The first PDCP sequence number is sent to the second user plane; the first PDCP sequence number is used by the second user plane to configure the PDCP sequence number of the second data packet.

28. The communication device according to claim 26, characterized in that The third node includes a second user plane of the third node and a second control plane of the third node; the sending unit is specifically configured to: The first PDCP sequence number is sent to the second control plane; the second control plane is used to send the first PDCP sequence number to the second user plane; the first PDCP sequence number is used by the second user plane to configure the PDCP sequence number of the second data packet.

29. The communication device according to any one of claims 22 to 28, characterized in that: Before sending the second data packet to the user equipment UE, the receiving unit is further configured to: A first message is received from the third node, where the first message is used to indicate the use of a data packet from the third node, and the first message is sent by the third node after receiving the first PDCP sequence number.

30. The communication device according to any one of claims 22 to 25, characterized in that: Before receiving the first data convergence protocol PDCP sequence number from the second node, the sending unit is further configured to: A first request is sent to the second node, where the first request is used to request the first PDCP sequence number.

31. The communication device according to any one of claims 22 to 30, characterized in that: Before receiving the first data convergence protocol PDCP sequence number from the second node, the receiving unit is further configured to: A first data packet is received from the second node, where a first PDCP sequence number of the first data packet belongs to a receiving window of a PDCP layer of the UE.

32. A communication device for multicast broadcast service, characterized in that: include: A receiving unit, configured to receive a first packet data convergence protocol PDCP sequence number from a first node, where the first PDCP sequence number is a PDCP sequence number of a first data packet sent by the second node at a first moment; A sending unit is used to send a second data packet to the first node, wherein the PDCP sequence number of the second data packet belongs to the receiving window of the PDCP layer of the user equipment UE; the first data packet and the second data packet are associated with a first multicast broadcast service.

33. The communication device according to claim 32, characterized in that: Before sending the second data packet to the first node, the sending unit is further used to: A first message is sent to the first node, where the first message is used to instruct the first node to use a data packet from the communication device.

34. The communication device according to claim 32 or 33, characterized in that: Before sending the second data packet to the first node, the device further includes a configuration unit, wherein the configuration unit is configured to: Based on the first PDCP sequence number, configure the PDCP sequence number of the second data packet.

35. A communication device for multicast broadcast service, characterized in that: include: The sending unit is configured to send a first data convergence protocol PDCP sequence number to the first node, where the first PDCP sequence number is the PDCP sequence number of a first data packet sent by the sending unit at a first moment.

36. The communication device according to claim 35, characterized in that The device further comprises a receiving unit, wherein the receiving unit is configured to: A first request is received from the first node, where the first request is used to request the first PDCP sequence number.

37. A communication device for multicast broadcast service, characterized in that: The device comprises: A sending unit, configured to send a first data packet to a user equipment UE based on a first multicast data radio bearer MRB configuration; the first data packet is sent by a second node to the communication device; The sending unit is configured to send a first message to the UE, where the first message includes parameter information of a second MRB configuration; the first MRB configuration is different from the second MRB configuration; The sending unit is configured to send a second message to the UE after sending the first message, where the second message includes parameter information configured by the first MRB; The sending unit is used to send a second data packet to the UE based on the first MRB configuration after sending the second message, where the second data packet is sent by a third node to the communication device; the first data packet and the second data packet are associated with a first multicast broadcast service.

38. The communication device according to claim 37, characterized in that: Before sending the first message to the UE, the apparatus further includes a receiving unit, wherein the receiving unit is configured to: A first request sent by the second node is received, where the first request includes a service identifier of the multicast broadcast service; and the first request is used to request to release a session of the multicast broadcast service of the second node.

39. The communication device according to claim 38, characterized in that The service identifier of the multicast broadcast service includes at least one of a session identifier of the multicast broadcast service, a temporary multicast group identifier TMGI and a service network identifier NID.

40. The communication device according to claims 37 to 39, characterized in that: There is at least one configuration parameter different between the parameter information of the first MRB configuration and the parameter information of the second MRB configuration, and the configuration parameter includes at least one of a data convergence protocol sequence number length, robust header compression, and a reordering timer.

41. The communication device according to any one of claims 37 to 40, characterized in that: When the moment when the communication device receives the first request is within a first multicast control channel MCCH modification period, the moment when the communication device sends the first message is within a second MCCH modification period, and the second MCCH modification period is the next MCCH modification period of the first MCCH modification period; The moment when the communication device sends the second message is within a third MCCH modification period, and the third MCCH modification period is the next MCCH modification period of the second MCCH modification period.

42. The communication device according to any one of claims 37 to 40, characterized in that: When the moment when the communication device sends the first message is within the fourth MCCH modification period, the moment when the communication device sends the second message is within the fifth MCCH modification period, and the fifth MCCH modification period is the next MCCH modification period of the fourth MCCH modification period.

43. A communication device for multicast broadcast service, characterized in that: The method comprises a processor and a memory, wherein the processor and the memory are coupled, and the processor calls a computer program stored in the memory to implement the method according to any one of claims 1 to 42.

44. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program or a computer instruction. When the computer program or the computer instruction is executed by a processor, the method according to any one of claims 1 to 42 is implemented.

45. A computer program product, characterized in that The computer program product comprises a computer program code, and when the computer program code is executed by a processor, the method according to any one of claims 1 to 42 is implemented.

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