Method for switching between multicast service transmission modes and related device

Abstract

A method for switching a multicast service transmission mode and related equipment, the method comprising: determining, by a base station, whether to switch a transmission mode of a first multicast service of a first terminal, the transmission mode comprising the following types: a shared transmission mode or MRB transmission, and a dedicated transmission mode or DRB transmission; in a case where the first multicast service needs to be switched from a first transmission mode to a second transmission mode, triggering, by the base station, the first terminal to establish or bind a core network tunnel related to the second transmission mode, or directly requesting, by the base station, a core network to establish or bind the core network tunnel related to the second transmission mode. Embodiments of the present application can realize a transmission switching process between MRB and DRB in terminal multicast service reception, can realize switching of a terminal between a target side and a source side supporting multicast transmission at different times, or dynamically change a transmission mode in a cell supporting multicast transmission.

Description

Technical Field

[0001] This invention relates to the field of mobile communication technology, specifically to a method and related equipment for converting multicast service transmission modes. Background Technology

[0002] Multicast / broadcast is a technology that transmits data from one data source to multiple target mobile terminals. This technology enables the sharing of network resources (including core network and access network) and improves the utilization of network resources, especially air interface resources. Currently, multicast service reception is usually achieved by the terminal connecting to a serving cell.

[0003] In existing technologies, whether multicast services are carried through a shared core network tunnel or a separate, UE-specific core network tunnel is determined by the core network or a higher application layer. Therefore, the triggering network element (such as the core network) possesses complete end-to-end bearer establishment information. On the other hand, multicast service reception in existing technologies is typically achieved by the terminal connecting to a serving cell. Therefore, there are scenarios where a user equipment (UE, also called a terminal) switches from a cell supporting multicast transmission to another cell that does not, and vice versa. In these scenarios, it is necessary to trigger a change in the multicast service transmission method of the UE, i.e., the radio side switches from MBMS Point-to-Multipoint Radio Bearer (MRB) to Data Radio Bearer (DRB) or vice versa. This process may occur during handover or before / after handover, but regardless of when it occurs, it requires triggering / decision-making by the radio side. However, the current radio side does not possess complete end-to-end bearer establishment information, making it difficult to implement the aforementioned conversion process. Summary of the Invention

[0004] At least one embodiment of the present invention provides a method and related equipment for converting multicast service transmission modes, which can realize the conversion of multicast service transmission modes on the wireless side.

[0005] According to one aspect of the present invention, at least one embodiment provides a method for switching multicast service transmission modes, applied to a base station, comprising:

[0006] The base station determines whether it is necessary to switch the transmission mode of the first multicast service of the first terminal, the transmission mode including: shared transmission mode or MRB transmission, and dedicated transmission mode or DRB transmission.

[0007] When it is necessary to switch the first multicast service from the first transmission mode to the second transmission mode, the base station triggers the establishment or binding of the core network tunnel related to the second transmission mode through the first terminal, or the base station directly requests the core network to establish or bind the core network tunnel related to the second transmission mode; wherein, the core network tunnel refers to the end-to-end transmission channel between the first terminal and the core network.

[0008] Furthermore, according to at least one embodiment of the present invention, the base station includes a DU and a CU;

[0009] The base station determines whether it needs to switch the transmission mode of the first multicast service of the first terminal, including:

[0010] The DU determines whether it is necessary to switch the transmission mode of the first multicast service of the first terminal based on at least one of the channel quality indication, HARQ feedback information and transmission mode switching request message sent by the first terminal, and when it determines that the transmission mode needs to be switched, it sends the first indication information to the CU through the uplink signaling of the F1 interface to indicate the switch of transmission mode.

[0011] Furthermore, according to at least one embodiment of the present invention, the base station includes a DU and a CU;

[0012] The base station determines whether it needs to switch the transmission mode of the first multicast service of the first terminal, including:

[0013] The CU determines whether it is necessary to switch the transmission mode of the first multicast service of the first terminal based on at least one of the channel quality indication, HARQ feedback information and transmission mode switching request message of the first terminal reported by the DU.

[0014] Furthermore, according to at least one embodiment of the present invention, the first transmission mode is a shared transmission mode or MRB, and the second transmission mode is a dedicated transmission mode or DRB; the base station triggers the establishment or binding of a core network tunnel related to the second transmission mode through a first terminal, including:

[0015] The CU sends a first RRC signaling to the first terminal, the first RRC signaling being used to trigger the first terminal to establish the core network tunnel for the second transmission mode of the first multicast service;

[0016] The CU receives a second indication information sent by the core network. The second indication information is used to indicate a first transmission channel between the core network and the CU. The first transmission channel is a transmission channel between the core network and the CU established by the core network according to the trigger of the first terminal for the second transmission mode of the first multicast service.

[0017] According to the second instruction information, the CU sends a first user context modification message for the first terminal to the DU, and sends a second RRC signaling to the first terminal to establish a first DRB and switch the first multicast service of the first terminal from the current MRB to the first DRB.

[0018] Furthermore, according to at least one embodiment of the present invention, the first transmission mode is a shared transmission mode or MRB, and the second transmission mode is a dedicated transmission mode or DRB; the base station directly requests the core network to establish or bind a core network tunnel related to the second transmission mode, including:

[0019] The CU sends a first request message carrying first terminal identification information to the core network. The first request message requests the core network to establish a second transmission channel between the core network and the CU for the second transmission mode of the first multicast service.

[0020] The CU receives a first response message sent by the core network, which carries a first NAS message. The first NAS message is the NAS message sent to the core network when the first terminal initially accesses the first multicast service.

[0021] The CU sends a second user context modification message for the first terminal to the DU, and sends a third RRC signaling to the first terminal to establish a first DRB, and switches the first multicast service of the first terminal from the current MRB to the first DRB.

[0022] Furthermore, according to at least one embodiment of the present invention, it further includes:

[0023] The CU stores the first NAS message sent to the core network when the first terminal initially accesses the first multicast service;

[0024] When the CU sends the first request message, it also carries the first NAS message in the first request message.

[0025] Furthermore, according to at least one embodiment of the present invention, it further includes:

[0026] When the CU saves the first NAS message, it sets a corresponding timer and starts timing.

[0027] When the CU receives the first indication information, it determines whether the timer has timed out:

[0028] If the timer has not expired, then the first request message is sent;

[0029] If the timer expires, a fourth RRC signaling is sent to the first terminal. The fourth RRC signaling is used to trigger the first terminal to establish the core network tunnel for the second transmission mode of the first multicast service. The CU receives a third indication information from the core network, which is used to indicate the second transmission channel between the core network and the CU. The second transmission channel is the transmission channel between the core network and the CU established by the core network according to the trigger of the first terminal for the second transmission mode of the first multicast service. The CU sends a third user context modification message for the first terminal to the DU, and sends a fifth RRC signaling to the first terminal to establish a first DRB and switch the first multicast service of the first terminal from the current MRB to the first DRB.

[0030] Furthermore, according to at least one embodiment of the present invention, the first transmission mode is a dedicated transmission mode or DRB, and the second transmission mode is a shared transmission mode or MRB; the base station triggers the establishment or binding of a core network tunnel related to the second transmission mode through a first terminal, including:

[0031] If the current serving cell of the first terminal has established the MRB of the first multicast service, the CU sends a fourth user context modification message for the first terminal to the DU, so that the DU sends a sixth RRC signaling to the first terminal. The sixth RRC signaling is used to switch the first multicast service of the first terminal from the current DRB to the MRB.

[0032] If the current serving cell of the first terminal has not established the MRB of the first multicast service, the CU sends a seventh RRC signaling to the first terminal. The seventh RRC signaling is used to instruct the first terminal to establish the MRB of the first multicast service and join the multicast group of the first multicast service through the multicast joining procedure.

[0033] Furthermore, according to at least one embodiment of the present invention, the base station includes a DU and a CU;

[0034] When the transmission mode of the first multicast service of the first terminal is MRB, the method further includes:

[0035] The CU receives terminal-related information of the first terminal reported by the DU. The terminal-related information is information related to the decision basis of the MRB transmission mode. The MRB transmission mode includes PTP and / or PTM.

[0036] The CU determines whether to perform the MRB transmission mode conversion of the first multicast service of the first terminal based on the terminal-related information of the first terminal, and sends a fourth indication information to the DU to indicate the MRB transmission mode conversion when it determines that the MRB transmission mode conversion is required.

[0037] The DU switches the MRB transmission mode of the first multicast service according to the fourth instruction information and sends a response message to the CU.

[0038] The CU receives the response message and sends a seventh RRC signaling to the first terminal. The seventh RRC signaling is used to instruct the first terminal to switch the MRB transmission mode of the first multicast service.

[0039] Furthermore, according to at least one embodiment of the present invention, the fourth indication information is also used to indicate at least one of the following: the RLC mode of the converted MRB transmission mode, and the retention time of the copy transmission; wherein the RLC mode includes an acknowledged mode and a non-acknowledged mode;

[0040] The response message is a downlink data transmission status message, or the response message is the maximum F1-U sequence number of the data packet that was successfully sent to the lower layer in the MRB transmission mode before the conversion.

[0041] The seventh RRC signaling carries the reset parameters of the terminal RLC receive window determined according to the RLC mode of the converted MRB transmission mode.

[0042] Furthermore, according to at least one embodiment of the present invention, the base station includes a DU and a CU;

[0043] When the transmission mode of the first multicast service of the first terminal is MRB, the method further includes:

[0044] Based on the terminal-related information of the first terminal, DU determines whether to perform the MRB transmission mode conversion of the first multicast service of the first terminal. The terminal-related information is the decision-making basis for the MRB transmission mode, and the MRB transmission mode includes PTP and / or PTM.

[0045] When the DU determines that an MRB transmission mode switch is required, it sends a fifth indication message to the CU to indicate that an MRB transmission mode switch should be performed.

[0046] According to the fifth indication information, the CU detects whether there is a GTP-U tunnel corresponding to the converted MRB transmission mode. If it exists, the CU sends a sixth indication information to the DU and an eighth RRC signaling to the first terminal to convert the MRB transmission mode of the first multicast service of the first terminal. If it does not exist, the CU initiates the establishment process of the GTP-U tunnel corresponding to the converted MRB transmission mode. After the GTP-U tunnel is successfully established, the CU sends a seventh indication information to the DU and a ninth RRC signaling to the first terminal to convert the MRB transmission mode of the first multicast service of the first terminal.

[0047] According to another aspect of the present invention, at least one embodiment provides a base station, comprising:

[0048] The decision module is used to determine whether it is necessary to switch the transmission mode of the first multicast service of the first terminal. The transmission mode includes the following types: shared transmission mode or MRB transmission, and dedicated transmission mode or DRB transmission.

[0049] The conversion processing module is used to, when it is necessary to convert the first multicast service from a first transmission mode to a second transmission mode, have the base station trigger the establishment or binding of a core network tunnel related to the second transmission mode through a first terminal, or have the base station directly request the core network to establish or bind a core network tunnel related to the second transmission mode; wherein, the core network tunnel refers to an end-to-end transmission channel between the first terminal and the core network.

[0050] Furthermore, according to at least one embodiment of the present invention, the base station includes a DU and a CU; the decision module is disposed in the DU;

[0051] The decision module is further configured to determine whether it is necessary to switch the transmission mode of the first multicast service of the first terminal based on at least one of the channel quality indication, HARQ feedback information and transmission mode switching request message sent by the first terminal, and when it is determined that the transmission mode needs to be switched, send first indication information to the CU through F1 interface uplink signaling to indicate the switching of transmission mode.

[0052] Furthermore, according to at least one embodiment of the present invention, the base station includes a DU and a CU; the decision module is disposed in the CU;

[0053] The decision module is further configured to determine whether it is necessary to switch the transmission mode of the first multicast service of the first terminal based on at least one of the channel quality indication, HARQ feedback information and transmission mode conversion request message of the first terminal reported by the DU.

[0054] Furthermore, according to at least one embodiment of the present invention, the first transmission mode is a shared transmission mode or MRB transmission, and the second transmission mode is a dedicated transmission mode or DRB transmission;

[0055] The conversion processing module is located in the CU;

[0056] The conversion processing module is further configured to: send a first RRC signaling to the first terminal when the establishment or binding of a core network tunnel related to the second transmission mode is triggered by the first terminal; trigger the first terminal to establish the core network tunnel for the second transmission mode of the first multicast service; receive a second indication information sent by the core network; the second indication information is used to indicate a first transmission channel between the core network and the CU; the first transmission channel is a transmission channel between the core network and the CU established by the core network for the second transmission mode of the first multicast service based on the triggering of the first terminal; send a first user context modification message for the first terminal to the DU according to the second indication information; and send a second RRC signaling to the first terminal to establish a first DRB and convert the first multicast service of the first terminal from the current MRB to the first DRB.

[0057] Furthermore, according to at least one embodiment of the present invention, the first transmission mode is a shared transmission mode or MRB, and the second transmission mode is a dedicated transmission mode or DRB;

[0058] The conversion processing module is located in the CU;

[0059] The conversion processing module is further configured to: send a first request message carrying first terminal identification information to the core network when directly requesting the core network to establish or bind a core network tunnel related to the second transmission mode; request the core network to establish a second transmission channel between the core network and the CU for the second transmission mode of the first multicast service; receive a first response message carrying a first NAS message sent by the core network, the first NAS message being the NAS message sent to the core network when the first terminal initially accesses the first multicast service; send a second user context modification message for the first terminal to the DU; and send a third RRC signaling to the first terminal to establish a first DRB and convert the first multicast service of the first terminal from the current MRB to the first DRB.

[0060] Furthermore, according to at least one embodiment of the present invention, it further includes:

[0061] The storage module is used to store the first NAS message sent to the core network when the first terminal initially accesses the first multicast service;

[0062] When sending the first request message, the conversion processing module also carries the first NAS message in the first request message.

[0063] Furthermore, according to at least one embodiment of the present invention, it further includes:

[0064] The timing module is used to set a corresponding timer and start timing when saving the first NAS message;

[0065] The conversion processing module is further configured to determine whether the timer has timed out upon receiving the first indication information:

[0066] If the timer has not expired, then the first request message is sent;

[0067] If the timer expires, a fourth RRC signaling is sent to the first terminal. The fourth RRC signaling is used to trigger the first terminal to establish the core network tunnel for the second transmission mode of the first multicast service. The CU receives a third indication information from the core network, which is used to indicate the second transmission channel between the core network and the CU. The second transmission channel is the transmission channel between the core network and the CU established by the core network according to the trigger of the first terminal for the second transmission mode of the first multicast service. The CU sends a third user context modification message for the first terminal to the DU, and sends a fifth RRC signaling to the first terminal to establish a first DRB and switch the first multicast service of the first terminal from the current MRB to the first DRB.

[0068] Furthermore, according to at least one embodiment of the present invention, the first transmission mode is a dedicated transmission mode or DRB, and the second transmission mode is a shared transmission mode or MRB;

[0069] The conversion processing module is located in the CU;

[0070] The conversion processing module is also used when the establishment or binding of the core network tunnel related to the second transmission mode is triggered by the first terminal:

[0071] If the current serving cell of the first terminal has established the MRB of the first multicast service, the CU sends a fourth user context modification message for the first terminal to the DU, so that the DU sends a sixth RRC signaling to the first terminal. The sixth RRC signaling is used to switch the first multicast service of the first terminal from the current DRB to the MRB.

[0072] If the current serving cell of the first terminal has not established the MRB of the first multicast service, the CU sends a seventh RRC signaling to the first terminal. The seventh RRC signaling is used to instruct the first terminal to establish the MRB of the first multicast service and join the multicast group of the first multicast service through the multicast joining procedure.

[0073] Furthermore, according to at least one embodiment of the present invention, the base station includes a DU and a CU; the decision module is disposed in the CU;

[0074] The decision module is further configured to receive terminal-related information of the first terminal reported by the DU when the transmission mode of the first multicast service of the first terminal is MRB. The terminal-related information is information related to the decision basis of the MRB transmission mode, and the MRB transmission mode includes PTP and / or PTM. Based on the terminal-related information of the first terminal, the module determines whether to perform the MRB transmission mode conversion of the first multicast service of the first terminal, and when it is determined that the MRB transmission mode conversion needs to be performed, the module sends a fourth indication information to the DU to indicate the MRB transmission mode conversion.

[0075] The DU is used to switch the MRB transmission mode of the first multicast service according to the fourth indication information and send a response message to the CU;

[0076] The CU is used to receive the response message and send a seventh RRC signaling to the first terminal. The seventh RRC signaling is used to instruct the first terminal to switch the MRB transmission mode of the first multicast service.

[0077] Furthermore, according to at least one embodiment of the present invention, the fourth indication information is also used to indicate at least one of the following: the RLC mode of the converted MRB transmission mode, and the retention time of the copy transmission; wherein the RLC mode includes an acknowledged mode and a non-acknowledged mode;

[0078] The response message is a downlink data transmission status message, or the response message is the maximum F1-U sequence number of the data packet that was successfully sent to the lower layer in the MRB transmission mode before the conversion.

[0079] The seventh RRC signaling carries the reset parameters of the terminal RLC receive window determined according to the RLC mode of the converted MRB transmission mode.

[0080] Furthermore, according to at least one embodiment of the present invention, the base station includes a DU and a CU; the decision module is disposed in the DU;

[0081] The decision module is further configured to determine whether to perform an MRB transmission mode conversion for the first multicast service of the first terminal based on the terminal-related information of the first terminal, wherein the terminal-related information is information related to the decision basis of the MRB transmission mode, and the MRB transmission mode includes PTP and / or PTM; when it is determined that an MRB transmission mode conversion is required, a fifth indication message is sent to the CU to indicate that an MRB transmission mode conversion should be performed.

[0082] The CU is used to detect whether a GTP-U tunnel corresponding to the converted MRB transmission mode exists according to the fifth indication information. If it exists, the CU sends a sixth indication information to the DU and an eighth RRC signaling to the first terminal to convert the MRB transmission mode of the first multicast service of the first terminal. If it does not exist, the CU initiates the establishment process of the GTP-U tunnel corresponding to the converted MRB transmission mode. After the GTP-U tunnel is successfully established, the CU sends a seventh indication information to the DU and a ninth RRC signaling to the first terminal to convert the MRB transmission mode of the first multicast service of the first terminal.

[0083] According to another aspect of the present invention, at least one embodiment provides a base station, including: a processor, a memory, and a program stored in the memory and executable on the processor, wherein the program, when executed by the processor, implements the steps of the method described above.

[0084] According to another aspect of the present invention, at least one embodiment provides a computer-readable storage medium on which a program is stored, which, when executed by a processor, implements the steps of the method described above.

[0085] Compared with the prior art, the multicast service transmission mode conversion method and related equipment provided in the embodiments of the present invention can realize the transmission conversion process between MRB and DRB in the multicast service reception of the terminal, and can realize the switching between the target side and the source side of multicast transmission supported by the terminal at different times, or dynamically change the transmission mode within the cell that supports multicast transmission. Attached Figure Description

[0086] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0087] Figure 1 This is a schematic diagram of an application scenario according to an embodiment of the present invention;

[0088] Figure 2 This is a schematic diagram illustrating one configuration of the decision-making layer according to an embodiment of the present invention;

[0089] Figure 3 This is a schematic diagram illustrating another configuration of the decision-making layer according to an embodiment of the present invention;

[0090] Figure 4 This is a schematic diagram illustrating another configuration of the decision-making layer according to an embodiment of the present invention;

[0091] Figure 5 A flowchart of a method for converting multicast service transmission modes provided in an embodiment of the present invention;

[0092] Figure 6 This is a schematic diagram of a base station structure provided in an embodiment of the present invention;

[0093] Figure 7 This is another structural schematic diagram of a base station provided in an embodiment of the present invention. Detailed Implementation

[0094] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0095] The terms “first,” “second,” etc., used in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus. The terms “and / or” in the specification and claims indicate at least one of the connected objects.

[0096] The technologies described in this document are not limited to NR systems and Long Time Evolution (LTE) / LTE-Advanced (LTE-A) systems, but can also be used in various wireless communication systems such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency-Division Multiple Access (SC-FDMA), and other systems. The terms "system" and "network" are often used interchangeably. CDMA systems can implement radio technologies such as CDMA2000 and Universal Terrestrial Radio Access (UTRA). UTRA includes Wideband Code Division Multiple Access (WCDMA) and other CDMA variants. TDMA systems can implement radio technologies such as the Global System for Mobile Communication (GSM). OFDMA systems can implement radio technologies such as Ultra Mobile Broadband (UMB), Evolution-UTRA (E-UTRA), IEEE 802.21 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and Flash-OFDM. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). LTE and more advanced LTE (such as LTE-A) are newer versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization called the 3rd Generation Partnership Project (3GPP). CDMA2000 and UMB are described in documents from an organization called 3rd Generation Partnership Project 2 (3GPP2).The techniques described herein can be used with the systems and radio technologies mentioned above, as well as with other systems and radio technologies. However, the following description describes NR systems for illustrative purposes, and NR terminology is used in most of the following description, although these techniques can also be applied to applications beyond NR systems.

[0097] The following description provides examples and is not intended to limit the scope, applicability, or configuration set forth in the claims. Changes may be made to the function and arrangement of the elements discussed without departing from the spirit and scope of this disclosure. Various procedures or components may be appropriately omitted, substituted, or added to the examples. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Furthermore, features described with reference to certain examples may be combined in other examples.

[0098] Please see Figure 1 , Figure 1 This diagram illustrates a block diagram of a wireless communication system applicable to an embodiment of the present invention. The wireless communication system includes a terminal 11 and a network device 12. The terminal 11 can also be referred to as a user terminal or user equipment (UE). The terminal 11 can be a mobile phone, tablet computer, laptop computer, personal digital assistant (PDA), mobile internet device (MID), wearable device, or in-vehicle device, etc. It should be noted that the specific type of terminal 11 is not limited in this embodiment of the present invention. Network device 12 can be a base station and / or a core network element. The base station can be a 5G or later version base station (e.g., gNB, 5G NR NB, etc.), or a base station in other communication systems (e.g., eNB, WLAN access point, or other access point, etc.). The base station can be referred to as a node B, evolved node B, access point, base transceiver station (BTS), radio base station, radio transceiver, basic service set (BSS), extended service set (ESS), B node, evolved B node (eNB), home B node, home evolved B node, WLAN access point, WiFi node, or any other suitable term in the field, as long as the same technical effect is achieved. The base station is not limited to specific technical terms. It should be noted that in the embodiments of the present invention, only the base station in the NR system is used as an example, but the specific type of base station is not limited.

[0099] The base station can communicate with terminal 11 under the control of a base station controller, which in various examples may be part of the core network or some base stations. Some base stations may communicate control information or user data with the core network via backhaul. In some examples, some of these base stations may communicate with each other directly or indirectly via backhaul links, which may be wired or wireless communication links. The wireless communication system may support operation on multiple carriers (waveform signals of different frequencies). A multi-carrier transmitter can transmit modulated signals on multiple carriers simultaneously. For example, each communication link may be a multi-carrier signal modulated according to various radio technologies. Each modulated signal may be transmitted on a different carrier and may carry control information (e.g., reference signals, control channels, etc.), overhead information, data, etc.

[0100] The base station can wirelessly communicate with terminal 11 via one or more access point antennas. Each base station can provide communication coverage for its respective coverage area. The coverage area of ​​an access point can be divided into sectors that constitute only a part of that coverage area. The wireless communication system may include different types of base stations (e.g., macro base stations, micro base stations, or pico base stations). Base stations may also utilize different radio technologies, such as cellular or WLAN radio access technologies. Base stations may be associated with the same or different access networks or operator deployments. The coverage areas of different base stations (including coverage areas of the same or different types of base stations, coverage areas using the same or different radio technologies, or coverage areas belonging to the same or different access networks) may overlap.

[0101] Communication links in a wireless communication system may include an uplink for carrying uplink (UL) transmissions (e.g., from terminal 11 to network device 12) or a downlink for carrying downlink (DL) transmissions (e.g., from network device 12 to terminal 11). UL transmissions may also be referred to as reverse link transmissions, and DL transmissions may also be referred to as forward link transmissions. Downlink transmissions may be carried out using licensed frequency bands, unlicensed frequency bands, or both. Similarly, uplink transmissions may be carried out using licensed frequency bands, unlicensed frequency bands, or both.

[0102] As described in the background section, existing wireless technologies lack complete end-to-end bearer establishment information, making it difficult to switch multicast service transmission modes. Furthermore, transmission mode switching scenarios may occur within a cell that supports multicast services. Therefore, it is desirable for the wireless side to dynamically change the transmission mode for the UE based on UE requirements to meet UE QoS requirements. Specifically, in a Central Unit-Distributed Unit (CU-DU) architecture, specific solutions are needed for how the wireless side triggers the aforementioned switching process and how to implement the switching procedure. Additionally, there are currently no publicly available solutions for the dynamic switching of multicast transmission modes (PTM and PTP).

[0103] To address at least one of the above problems, embodiments of the present invention provide a method for switching multicast service transmission modes, which enables the switching of multicast service transmission modes on the wireless side.

[0104] In this embodiment of the invention, for multicast services, the network-side protocol stack has a sublayer / functional module for deciding / converting the transmission mode of the multicast service. This includes the initial transmission mode within the transmission range of a UE / cell / Multicast Broadcast Service (MBS), such as DRB (Individual Delivery Mode) or MRB (Shared Delivery Mode). Specifically, for MRB, it may also include deciding whether to use Point-to-Point (PTP) or Point-to-Multipoint (PTM) mode, as well as the decision on dynamic conversion between PTP / PTM during UE service reception, and / or the conversion between MBR (Shared Delivery Mode) and DRB (Individual Delivery Mode). This sublayer may be a virtual sublayer / function located in other layers, or it may be a separate sublayer. In this embodiment of the invention, the sublayer / function is identified by a decision layer or decision module, and this sublayer / function exists only in the base station-side protocol stack.

[0105] In a CU-DU architecture, this decision-making layer / module may be located in the CU and / or DU. Figures 2-4 Examples of its possible locations, in Figures 2-4 The decision-making layer / decision-making module mentioned above is referred to as the decision-making layer. Figures 2-4 This only indicates that the decision-making layer is mostly an independent sub-layer, but it can also belong to a certain sub-layer as a certain functional module. For example, when the decision-making layer is in the CU, it can belong to the PDCP, that is, as a part of the PDCP layer. Or, when the decision-making layer is in the DU, it can belong to the RLC / MAC, that is, as a part of the RLC / MAC layer.

[0106] Please refer toFigure 5 The present invention provides a method for converting multicast service transmission modes, comprising:

[0107] Step 21: The base station determines whether it is necessary to switch the transmission mode of the first multicast service of the first terminal. The transmission mode includes the following types: shared transmission mode or MRB transmission, and dedicated transmission mode or DRB transmission.

[0108] Here, the decision module (also known as the decision layer) in the base station can determine whether it is necessary to switch the transmission mode of the first multicast service. The transmission modes include shared delivery mode and individual delivery mode. Shared delivery mode is mapped to the MRB on the radio side, and is therefore sometimes referred to as MRB transmission. Individual delivery mode is mapped to the DRB on the radio side, and is therefore sometimes referred to as DRB transmission. The first multicast service can be a multicast, broadcast, or multicast service.

[0109] Step 22: When it is necessary to switch the first multicast service from the first transmission mode to the second transmission mode, the base station triggers the establishment or binding of the core network tunnel related to the second transmission mode through the first terminal, or the base station directly requests the core network to establish or bind the core network tunnel related to the second transmission mode.

[0110] Here, the core network tunnel refers to the end-to-end transmission channel between the first terminal and the core network. When it is necessary to switch the transmission mode of the first multicast service, for example, when switching from the current first transmission mode to the second transmission mode, the base station can trigger the establishment or binding of the core network tunnel related to the second transmission mode through the first terminal, or the base station can directly send a request to the core network to establish or bind the core network tunnel related to the second transmission mode.

[0111] Through the above steps, this embodiment of the invention achieves the conversion of multicast service transmission mode on the wireless side.

[0112] The above steps will be explained in detail below, taking into account the different structures of base stations and the different deployment methods of decision-making modules.

[0113] I. In the CU-DU architecture, the decision-making module (decision layer) is located in the DU.

[0114] In the CU-DU architecture, the base station includes DU and CU. When the decision module is located in DU, in step 21 above, DU determines whether it is necessary to switch the transmission mode of the first multicast service of the first terminal based on at least one of the channel quality indication, HARQ feedback information and transmission mode conversion request message sent by the first terminal. When it is determined that the transmission mode needs to be switched, DU sends the first indication information to CU through F1 uplink signaling to indicate the switch of transmission mode.

[0115] For example, the DU (Distribution Unit) determines whether to change the UE's transmission mode based on the UE's CQI reporting, HARQ feedback (statistics), or UE requests, primarily considering the conversion between MRB (Medium-Range Base) and DRB (Digital Radius Base). This decision may be based on criteria configured in the OAM / CN / CU (Operational Access Center / Content Management Center) for information collection / request and decision-making. These criteria may include information such as the periodicity / non-periodicity of information collection, decision thresholds, and threshold availability duration. For instance, UE HARQ feedback may be collected periodically according to the configuration and statistically analyzed, and then a decision is made based on the configured thresholds. After the DU makes a decision, it can indicate this to the CU (Currency Management Center) via uplink signaling on the F1 interface. This indication can be included in existing F1 interface signaling, such as adding an IE (Interface Request) in the UE context modification request (UE CONTEXT MODIFICATION REQUIRED), or indicating it through new signaling.

[0116] In step 22 above, after receiving the decision from the DU, the CU can process it in the following way:

[0117] 1) MRB->DRB:

[0118] Here, it is assumed that the first transmission mode is a shared transmission mode or MRB transmission, and the second transmission mode is a dedicated transmission mode or DRB transmission. In this case, the CU may establish the DRB through one of the following two methods.

[0119] Method 1: The CU triggers the establishment or binding of the core network tunnel related to the second transmission mode through the first terminal.

[0120] The CU sends a first RRC signaling message to the first terminal, which triggers the first terminal to establish the core network tunnel (an end-to-end transmission channel between the terminal and the core network) for the second transmission mode of the first multicast service. Then, the CU receives second indication information from the core network, which indicates a first transmission channel between the core network and the CU. This first transmission channel is established by the core network based on the triggering of the first terminal for the second transmission mode of the first multicast service. Then, based on the second indication information, the CU sends a first user context modification message for the first terminal to the DU, and sends a second RRC signaling message to the first terminal to establish a first DRB and switch the first multicast service of the first terminal from the current MRB to the first DRB. Here, the first DRB is the DRB corresponding to the second transmission mode of the first multicast service.

[0121] The above process specifically includes:

[0122] A) The CU sends a first RRC signaling message to the first terminal. This first RRC signaling message triggers the first terminal to establish an end-to-end transmission channel between the terminal and the core network for the second transmission mode of the first multicast service. Here, the end-to-end channel includes the transmission channel between the core network and the radio side, and the transmission channel between the radio side and the first terminal. The first RRC signaling message can be a new RRC signaling message, an RRC reconfiguration message, or an RRC release message. Its main function is to instruct the UE to trigger the end-to-end transmission channel with the first multicast service.

[0123] B) After the UE receives the first RRC signaling from the CU, it initiates a DRB establishment request, which includes a NAS message to be sent to the core network (if an RRC release message is received, the RRC connection establishment is re-initiated). Possibly, the UE may indicate in its DRB establishment request reason that it is related to multicast transmission, or carry a multicast service identifier, such as TMGI, the PDU Session ID allocated by the MRB corresponding to the requested DRB, the source multicast IP address corresponding to the MRB, and the shared tunnel information corresponding to the MRB. Based on the aforementioned NAS message, the core network establishes a transmission channel between the core network and the CU for the second transmission mode of the first multicast service.

[0124] C) The core network sends a second indication message to the CU, the second indication message being used to indicate to the CU the first transmission channel between the core network and the radio side. The CU receives the second indication message sent by the core network.

[0125] D) The CU establishes a first DRB based on the second indication information received from the core network. Specifically, the CU sends a first user context modification message (UE CONTEXT MODIFICATION) for the first terminal to the DU, and sends a second RRC signaling (such as an RRC reconfiguration message) to the first terminal to establish the first DRB and transfer the first multicast service of the first terminal from the current MRB to the first DRB. The second RRC signaling may include DRB-related configurations, such as PDCP, RLC, MAC, and physical layer configurations.

[0126] Here, the CU establishes the RAN-side protocol stack by sending a UE CONTEXT MODIFICATION message to the DU, and sends an RRC reconfiguration message to the first terminal to establish the UE-side protocol stack, thereby ultimately establishing the first DRB. In addition, the NAS message carries session-related information (i.e., the channel information established by the CN, which the base station transparently transmits).

[0127] Method 2: The CU directly requests the core network to establish or bind a core network tunnel related to the second transmission mode.

[0128] The CU sends a first request message carrying first terminal identification information to the core network. The first request message requests the core network to establish a second transmission channel between the core network and the CU for the first terminal in the second transmission mode of the first multicast service. The CU receives a first response message carrying a first NAS message sent by the core network. The first NAS message is the NAS message sent to the core network when the first terminal initially accesses the first multicast service. The CU sends a second user context modification message for the first terminal to the DU, and sends a third RRC signaling to the first terminal to establish a first DRB and switch the first multicast service of the first terminal from the current MRB to the first DRB.

[0129] The above process specifically includes:

[0130] A) When the first terminal initially accesses the multicast service (join process), the CU retains the NAS message that the UE transparently transmits to the CN. Optionally, a corresponding timer can be set for the retained UE NAS message, that is, the CU can only use the NAS message before the timer expires.

[0131] B) When the CU receives the transmission mode conversion decision from the DU, if the timer has not expired, the CU will send the retained NAS message and UE identification information such as UE ID (e.g., AMF UE NGAP ID, RAN UE NGAP ID) to the CN, requesting the CN to establish a transmission channel. If the timer has expired, the DRB establishment will be triggered through the procedure in Method 1 above.

[0132] Similarly, the CN side can retain the NAS messages of the first terminal, while the CU only sends a request message to the CN.

[0133] C) Upon receiving the CU's request, after establishing the second transmission channel between the CN and the CU, the CN sends a response message to reply to the CU's request. This response message may carry the corresponding NAS message.

[0134] D) The CU sends a UE CONTEXT MODIFICATION message to the DU for the first terminal, and sends an RRC reconfiguration message to the first terminal to transfer the transmission of the first multicast service of the first terminal from the MRB to the newly established first DRB.

[0135] Here, the CU establishes the RAN-side protocol stack by sending UE CONTEXT MODIFICATION to the DU, and sends an RRC reconfiguration message to the first terminal to establish the first terminal-side protocol stack, thereby ultimately establishing the first DRB. Additionally, the NAS message carries session-related information (i.e., the channel information established by the CN, which the base station transparently transmits).

[0136] During the above process, the CU can store the first NAS message sent to the core network when the first terminal initially accesses the first multicast service. Additionally, when sending the first request message, the CU can also include the first NAS message in the first request message.

[0137] Furthermore, when saving the first NAS message, the CU sets a corresponding timer and starts timing. Thus, when the CU receives the first indication information, it can determine whether the timer has timed out.

[0138] A) If the timer has not expired, then send the first request message;

[0139] B) If the timer has expired, a fourth RRC signaling is sent to the first terminal, the fourth RRC signaling being used to trigger the first terminal to establish the core network tunnel for the second transmission mode of the first multicast service; the CU receives a third indication information from the core network, the third indication information being used to indicate a second transmission channel between the core network and the CU, the second transmission channel being a transmission channel between the core network and the CU established by the core network according to the trigger of the first terminal for the second transmission mode of the first multicast service; the CU sends a third user context modification message for the first terminal to the DU, and sends a fifth RRC signaling to the first terminal to establish a first DRB and switch the first multicast service of the first terminal from the current MRB to the first DRB.

[0140] 2) DRB->MRB:

[0141] Here, we assume that the first transmission mode is a shared transmission mode or DRB, and the second transmission mode is a dedicated transmission mode or MRB. Then:

[0142] In step 22 above, the CU triggers the establishment or binding of the core network tunnel related to the second transmission mode through the first terminal, which may specifically include:

[0143] a) The current service cell has established MRB / shared delivery mode.

[0144] If the current serving cell of the first terminal has established the MRB of the first multicast service, the CU sends a fourth user context modification message for the first terminal to the DU, so that the DU sends a sixth RRC signaling to the first terminal. The sixth RRC signaling is used to switch the first multicast service of the first terminal from the current DRB to the MRB.

[0145] b) The current serving cell does not have MRB / shared delivery mode.

[0146] If the current serving cell of the first terminal has not established the MRB of the first multicast service, the CU sends a seventh RRC signaling to the first terminal. The seventh RRC signaling is used to instruct the first terminal to establish the MRB of the first multicast service and join the multicast group of the first multicast service through the multicast joining procedure.

[0147] II. In the CU-DU architecture, the decision-making module (decision layer) is located in the CU.

[0148] In the CU-DU architecture, the base station includes a DU and a CU. When the decision module is located in the CU, in step 21 above, the CU determines whether it is necessary to switch the transmission mode of the first multicast service of the first terminal based on at least one of the channel quality indication, HARQ feedback information, and transmission mode switching request message reported by the DU. Alternatively, when the first terminal switches, the CU decides whether a transmission mode switch is needed based on decision criteria provided by OAM / CN, etc.

[0149] When the CU decides to perform a transmission mode switch, it will check whether the NAS message of the first terminal is retained. If so, the CU can directly request the core network to trigger the establishment of the relevant channel. Otherwise, the CU will trigger the establishment or binding of the core network tunnel related to the second transmission mode through the first terminal, and then send the corresponding RRC reconfiguration message to the first terminal to realize the transmission mode switch. For the specific implementation methods of MRB->DRB and DRB->MRB, please refer to the explanation in the first item above, which will not be repeated here.

[0150] III. Integrated Base Station

[0151] The method described above is also applicable to integrated base stations. The base station makes decisions on the transmission mode of the UE based on certain criteria and establishes relevant channels by triggering the UE or directly requesting the core network.

[0152] The following explains the conversion of transmission modes under MRB (conversion between PTP and PTM).

[0153] Regarding the specific transmission mode under MRB, when the decision layer is located in CU or above DU RLC layer, the decision layer can not only determine the transmission mode of a UE, but also make decisions on the transmission mode of the entire cell.

[0154] Under the CU-DU architecture, in this embodiment of the invention, when the transmission mode of the first multicast service of the first terminal is MRB, the MRB transmission mode can be switched. The MRB transmission mode includes PTP and / or PTM. Specifically, the decision can be made on a per-UE basis or on a per-cell basis to determine whether the MRB transmission mode needs to be switched.

[0155] A. Each UE makes a decision (Per UE decision)

[0156] 1) The decision-making level is located in CU

[0157] When the transmission mode of the first multicast service of the first terminal is MRB, the CU receives terminal-related information of the first terminal reported by the DU. This terminal-related information is information related to the decision basis of the MRB transmission mode. Then, based on the terminal-related information of the first terminal, the CU determines whether to switch the MRB transmission mode of the first multicast service of the first terminal. If it determines that an MRB transmission mode switch is required, it sends a fourth indication message to the DU to instruct the MRB transmission mode switch. Then, the DU switches the MRB transmission mode of the first multicast service according to the fourth indication message and sends a response message to the CU. The CU receives the response message and sends a seventh RRC signaling to the first terminal. The seventh RRC signaling is used to instruct the first terminal to switch the MRB transmission mode of the first multicast service.

[0158] Here, the fourth indication information is also used to indicate at least one of the following: the RLC mode of the converted MRB transmission mode, and the retention time of the copy transmission; wherein, the RLC mode includes an acknowledged mode and an unacknowledged mode;

[0159] The response message is a downlink data transmission status message, or the response message is the maximum F1-U sequence number of the data packet that was successfully sent to the lower layer in the MRB transmission mode before the conversion; the F1-U sequence number refers to the user plane sequence number of the interface between the central unit and the distribution unit.

[0160] The seventh RRC signaling carries the reset parameters of the terminal RLC receive window determined according to the RLC mode of the converted MRB transmission mode.

[0161] Specifically, the criteria for MRB transmission mode switching decisions can be generated and sent to the CU by the OAM or CN network, or generated independently by the CU. These criteria may include one or more pieces of information such as the number of users receiving one or all multicast services within the cell, service QoS requirements, UE PTM / PTP leg channel quality, network resource / busy / idle status, UE requests, UE uplink feedback (PDCP status report, ARQ feedback, CQI), and related statistics. Based on different decision criteria, the DU needs to report relevant UE information to the CU accordingly, such as UE requests, UE uplink feedback (PDCP status report, ARQ feedback, CQI), and related statistics.

[0162] When the CU decides to perform a PTP / PTM conversion on the first terminal, the CU needs to send relevant indication information to the DU, indicating whether to switch from PTM to PTP, or from PTP to PTM, or to perform duplication transmission or cancel duplication transmission. The CU may also indicate the RLC mode of the converted transmission path (leg) (e.g., PTM only supports unacknowledged mode UM, while PTP can support UM or acknowledged mode AM), as well as the retention time of the converted leg. This indication information can be carried through the UE CONTEXT MODIFICATION REQUEST on the F1 interface; or by adding a corresponding indication bit to the F1 interface data packet header; or, if there is no corresponding GTP-U tunnel for the PTP / PTM leg, by indicating this information during the tunnel establishment process.

[0163] After receiving the decision from the CU, the DU sends a UE CONTEXT MODIFICATION RESPONSE message to the CU, which may carry the maximum F1-U SN corresponding to the packet successfully sent to the lower layer by the current leg, and / or send a Downlink DataDelivery Status message to carry the maximum F1-U SN or other more information.

[0164] After receiving feedback from DU, CU sends an RRC reconfiguration message to the first terminal and may decide whether to reset the relevant parameters of the first terminal's RLC receive window based on the RLC mode of the new leg.

[0165] 2) The decision-making level is located in DU

[0166] When the transmission mode of the first multicast service of the first terminal is MRB, the DU determines whether to perform a conversion of the MRB transmission mode of the first multicast service of the first terminal based on the terminal-related information of the first terminal. The terminal-related information is information related to the decision-making basis of the MRB transmission mode, and the MRB transmission mode includes PTP and / or PTM. When the DU determines that a conversion of the MRB transmission mode is required, it sends a fifth indication message to the CU to indicate the MRB transmission mode conversion. Based on the fifth indication message, the CU checks whether a GTP-U tunnel corresponding to the converted MRB transmission mode exists. If it exists, the CU sends a sixth indication message to the DU and an eighth RRC signaling message to the first terminal to convert the MRB transmission mode of the first multicast service of the first terminal. If it does not exist, the CU initiates the establishment process of the GTP-U tunnel corresponding to the converted MRB transmission mode. After the GTP-U tunnel is successfully established, the CU sends a seventh indication message to the DU and a ninth RRC signaling message to the first terminal to convert the MRB transmission mode of the first multicast service of the first terminal.

[0167] Specifically, the criteria used for PTP / PTM switching decisions may be generated and distributed to the DU by the OAM, CN network, or CU, or generated by the DU itself. These criteria may include one or more of the following information: the number of users receiving one or all multicast services within the cell, service QoS requirements, UE PTM / PTP leg channel quality, network resource / busy / idle status, UE requests, UE uplink feedback (PDCP status report, ARQ feedback, CQI), and related statistics.

[0168] When the DU decides to perform a PTP / PTM transition for a UE, the DU needs to send relevant instructions to the CU, indicating whether to switch from PTM to PTP, or from PTP to PTM, or to perform duplication transmission or cancel duplication transmission. The DU may also indicate the RLC mode of the transmission leg after the transition, as well as the retention time of the leg after the transition. This message can be carried through the UE CONTEXT MODIFICATION REQUIRED on the F1 interface, and can also carry the maximum F1-U SN corresponding to the packet successfully sent to the lower layer by the current leg, or by adding corresponding indication bits to the Downlink Data Delivery Status on the F1 interface.

[0169] After receiving the decision from the DU, the CU needs to check if a corresponding GTP-U tunnel exists for the PTP and / or PTM links. If not, it needs to initiate the corresponding tunnel establishment process. Then, the CU sends the corresponding reception feedback to the DU (e.g., carried via a UE CONTEXT MODIFICATION RESPONDSE message) and exchanges tunnel information for the new leg. Additionally, the CU sends an RRC reconfiguration message to the first terminal to configure the transmission mode switch.

[0170] B. Decision-making is conducted for each individual neighborhood (Per-Neighborhood Decision-Making).

[0171] For cell-level transmission mode decisions, there is at least a decision layer above the RLC layer of the DU or in the CU, and it is not ruled out that there is also a decision layer within the DU. The CU's decision on cell transmission mode switching may be based on statistics of at least one of the following: the UE's layer 3 filtering results, or information reported by the DU such as UE requests, UE uplink feedback (PDCP status report, ARQ feedback, CQI) and related statistics, or decisions made within the DU per UE.

[0172] As can be seen from the above, the embodiments of the present invention can realize the transmission conversion process between MRB and DRB in the multicast service reception of the terminal, and can realize the switching between the target side and the source side of multicast transmission supported by the terminal at different times, or dynamically change the transmission mode within the cell that supports multicast transmission.

[0173] The various methods of the embodiments of the present invention have been described above. Apparatus for implementing the above methods will now be provided.

[0174] The embodiments of the present invention provide Figure 6 The base station shown includes:

[0175] Decision module 61 is used to determine whether it is necessary to switch the transmission mode of the first multicast service of the first terminal. The transmission mode includes the following types: shared transmission mode or MRB transmission, and dedicated transmission mode or DRB transmission.

[0176] The conversion processing module 62 is used to, when it is necessary to convert the first multicast service from the first transmission mode to the second transmission mode, have the base station trigger the establishment or binding of a core network tunnel related to the second transmission mode through the first terminal, or have the base station directly request the core network to establish or bind a core network tunnel related to the second transmission mode; wherein, the core network tunnel refers to the end-to-end transmission channel between the first terminal and the core network.

[0177] Preferably, the base station includes a DU and a CU; the decision module is provided in the DU;

[0178] The decision module is further configured to determine whether it is necessary to switch the transmission mode of the first multicast service of the first terminal based on at least one of the channel quality indication, HARQ feedback information and transmission mode switching request message sent by the first terminal, and when it is determined that the transmission mode needs to be switched, send first indication information to the CU through F1 interface uplink signaling to indicate the switching of transmission mode.

[0179] Preferably, the base station includes a DU and a CU; the decision module is provided in the CU;

[0180] The decision module is further configured to determine whether it is necessary to switch the transmission mode of the first multicast service of the first terminal based on at least one of the channel quality indication, HARQ feedback information and transmission mode conversion request message of the first terminal reported by the DU.

[0181] Preferably, the first transmission mode is a shared transmission mode or MRB transmission, and the second transmission mode is a dedicated transmission mode or DRB transmission;

[0182] The conversion processing module is located in the CU;

[0183] The conversion processing module is further configured to: send a first RRC signaling to the first terminal when the establishment or binding of a core network tunnel related to the second transmission mode is triggered by the first terminal; trigger the first terminal to establish the core network tunnel for the second transmission mode of the first multicast service; receive second indication information sent by the core network; the second indication information is used to indicate a first transmission channel between the core network and the CU; the first transmission channel is a transmission channel between the core network and the CU established by the core network for the second transmission mode of the first multicast service based on the triggering of the first terminal; send a first user context modification message for the first terminal to the DU according to the second indication information; and send a second RRC signaling to the first terminal to establish a first DRB corresponding to the current MRB of the first multicast service and convert the first multicast service of the first terminal from the current MRB to the first DRB.

[0184] Preferably, the first transmission mode is a shared transmission mode or MRB transmission, and the second transmission mode is a dedicated transmission mode or DRB transmission;

[0185] The conversion processing module is located in the CU;

[0186] The conversion processing module is further configured to: send a first request message carrying first terminal identification information to the core network when directly requesting the core network to establish or bind a core network tunnel related to the second transmission mode; request the core network to establish a second transmission channel between the core network and the CU for the second transmission mode of the first multicast service; receive a first response message carrying a first NAS message sent by the core network, the first NAS message being the NAS message sent to the core network when the first terminal initially accesses the first multicast service; send a second user context modification message for the first terminal to the DU; and send a third RRC signaling to the first terminal to establish a first DRB and convert the first multicast service of the first terminal from the current MRB to the first DRB.

[0187] Preferably, the base station further includes:

[0188] The storage module is used to store the first NAS message sent to the core network when the first terminal initially accesses the first multicast service;

[0189] When sending the first request message, the conversion processing module also carries the first NAS message in the first request message.

[0190] Preferably, the base station further includes:

[0191] The timing module is used to set a corresponding timer and start timing when saving the first NAS message;

[0192] The conversion processing module is further configured to determine whether the timer has timed out upon receiving the first indication information:

[0193] If the timer has not expired, then the first request message is sent;

[0194] If the timer expires, a fourth RRC signaling is sent to the first terminal. The fourth RRC signaling is used to trigger the first terminal to establish the core network tunnel for the second transmission mode of the first multicast service. The CU receives a third indication information from the core network, which is used to indicate the second transmission channel between the core network and the CU. The second transmission channel is the transmission channel between the core network and the CU established by the core network according to the trigger of the first terminal for the second transmission mode of the first multicast service. The CU sends a third user context modification message for the first terminal to the DU, and sends a fifth RRC signaling to the first terminal to establish a first DRB and switch the first multicast service of the first terminal from the current MRB to the first DRB.

[0195] Preferably, the first transmission mode is a dedicated transmission mode or DRB, and the second transmission mode is a shared transmission mode or MRB;

[0196] The conversion processing module is located in the CU;

[0197] The conversion processing module is also used when the establishment or binding of the core network tunnel related to the second transmission mode is triggered by the first terminal:

[0198] If the current serving cell of the first terminal has established the MRB of the first multicast service, the CU sends a fourth user context modification message for the first terminal to the DU, so that the DU sends a sixth RRC signaling to the first terminal. The sixth RRC signaling is used to switch the first multicast service of the first terminal from the current DRB to the MRB.

[0199] If the current serving cell of the first terminal has not established the MRB of the first multicast service, the CU sends a seventh RRC signaling to the first terminal. The seventh RRC signaling is used to instruct the first terminal to establish the MRB of the first multicast service and join the multicast group of the first multicast service through the multicast joining procedure.

[0200] Preferably, the base station includes a DU and a CU; the decision module is provided in the CU;

[0201] The decision module is further configured to receive terminal-related information of the first terminal reported by the DU when the transmission mode of the first multicast service of the first terminal is MRB. The terminal-related information is information related to the decision basis of the MRB transmission mode, and the MRB transmission mode includes PTP and / or PTM. Based on the terminal-related information of the first terminal, the module determines whether to perform the MRB transmission mode conversion of the first multicast service of the first terminal, and when it is determined that the MRB transmission mode conversion needs to be performed, the module sends a fourth indication information to the DU to indicate the MRB transmission mode conversion.

[0202] The DU is used to switch the MRB transmission mode of the first multicast service according to the fourth indication information and send a response message to the CU;

[0203] The CU is used to receive the response message and send a seventh RRC signaling to the first terminal. The seventh RRC signaling is used to instruct the first terminal to switch the MRB transmission mode of the first multicast service.

[0204] Preferably, the fourth indication information is further used to indicate at least one of the following: the RLC mode of the converted MRB transmission mode, and the retention time of the copy transmission; wherein the RLC mode includes an acknowledged mode and a non-acknowledged mode;

[0205] The response message is a downlink data transmission status message, or the response message is the maximum F1-U sequence number of the data packet that was successfully sent to the lower layer in the MRB transmission mode before the conversion.

[0206] The seventh RRC signaling carries the reset parameters of the terminal RLC receive window determined according to the RLC mode of the converted MRB transmission mode.

[0207] Preferably, the base station includes a DU and a CU; the decision module is provided in the DU;

[0208] The decision module is further configured to determine whether to perform an MRB transmission mode conversion for the first multicast service of the first terminal based on the terminal-related information of the first terminal, wherein the terminal-related information is information related to the decision basis of the MRB transmission mode, and the MRB transmission mode includes PTP and / or PTM; when it is determined that an MRB transmission mode conversion is required, a fifth indication message is sent to the CU to indicate that an MRB transmission mode conversion should be performed.

[0209] The CU is used to detect whether a GTP-U tunnel corresponding to the converted MRB transmission mode exists according to the fifth indication information. If it exists, it sends a sixth indication information to the DU and an eighth RRC signaling to the first terminal to convert the MRB transmission mode of the first multicast service of the first terminal. If it does not exist, it initiates the establishment process of the GTP-U tunnel corresponding to the converted MRB transmission mode. After the GTP-U tunnel is successfully established, it sends a seventh indication information to the DU and a ninth RRC signaling to the first terminal to convert the MRB transmission mode of the first multicast service of the first terminal. It should be noted that the device in this embodiment is similar to the one described above. Figure 5 The devices corresponding to the methods shown are all applicable to the embodiments of the above-described devices, and can achieve the same technical effects. It should be noted that the devices provided in this embodiment can implement all the method steps implemented in the above-described method embodiments and achieve the same technical effects. Therefore, the parts and beneficial effects that are the same as those in the method embodiments will not be described in detail here.

[0210] Please refer to Figure 7 This invention provides a schematic diagram of a base station structure, including: a processor 701, a transceiver 702, a memory 703, and a bus interface, wherein:

[0211] In this embodiment of the invention, the base station further includes: a program stored in a memory 703 and executable on a processor 701, wherein the program, when executed by the processor 701, performs the following steps:

[0212] The base station determines whether it is necessary to switch the transmission mode of the first multicast service of the first terminal, the transmission mode including: shared transmission mode or MRB, and dedicated transmission mode or DRB.

[0213] When it is necessary to switch the first multicast service from the first transmission mode to the second transmission mode, the base station triggers the establishment or binding of the core network tunnel related to the second transmission mode through the first terminal, or the base station directly requests the core network to establish or bind the core network tunnel related to the second transmission mode; wherein, the core network tunnel refers to the end-to-end transmission channel between the first terminal and the core network.

[0214] Understandably, in this embodiment of the invention, the computer program executed by the processor 701 can achieve the above-mentioned functions. Figure 5 The various processes of the method embodiments shown can achieve the same technical effect, and will not be described again here to avoid repetition.

[0215] exist Figure 7In this context, the bus architecture can include any number of interconnected buses and bridges, specifically linking various circuits together, represented by one or more processors (processor 701) and memory (memory 703). The bus architecture can also link together various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. The bus interface provides an interface. The transceiver 702 can be multiple elements, including transmitters and receivers, providing a unit for communicating with various other devices over a transmission medium.

[0216] The processor 701 is responsible for managing the bus architecture and general processing, while the memory 703 can store the data used by the processor 701 when performing operations.

[0217] It should be noted that the terminal in this embodiment is the same as the one described above. Figure 5 The device corresponding to the method shown above, and the implementation methods in each embodiment, are all applicable to the embodiments of this terminal, and can achieve the same technical effect. In this device, the transceiver 702 and the memory 703, as well as the transceiver 702 and the processor 701, can be connected for communication via a bus interface. The function of the processor 701 can also be implemented by the transceiver 702, and the function of the transceiver 702 can also be implemented by the processor 701. It should be noted that the device provided by the embodiments of the present invention can implement all the method steps implemented in the above method embodiments and can achieve the same technical effect. Here, the parts that are the same as those in the method embodiments and the beneficial effects will not be described in detail.

[0218] In some embodiments of the present invention, a computer-readable storage medium is also provided, on which a program is stored, which, when executed by a processor, performs the following steps:

[0219] The base station determines whether it is necessary to switch the transmission mode of the first multicast service of the first terminal, the transmission mode including: shared transmission mode or MRB, and dedicated transmission mode or DRB;

[0220] When it is necessary to switch the first multicast service from the first transmission mode to the second transmission mode, the base station triggers the establishment or binding of the core network tunnel related to the second transmission mode through the first terminal, or the base station directly requests the core network to establish or bind the core network tunnel related to the second transmission mode.

[0221] When executed by the processor, this program can implement all the above-mentioned methods for converting the multicast service transmission mode applied to the base station, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0222] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0223] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0224] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0225] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of the present invention, depending on actual needs.

[0226] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0227] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0228] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for converting multicast service transmission modes, applied to a base station, characterized in that, include: The base station determines whether it is necessary to switch the transmission mode of the first multicast service of the first terminal. The transmission mode includes the following types: shared transmission mode or MRB transmission, and dedicated transmission mode or DRB transmission. When it is necessary to switch the first multicast service from the first transmission mode to the second transmission mode, the base station triggers the establishment or binding of the core network tunnel related to the second transmission mode through the first terminal, or the base station directly requests the core network to establish or bind the core network tunnel related to the second transmission mode; wherein, the core network tunnel refers to the end-to-end transmission channel between the first terminal and the core network. The base station includes a distribution unit (DU) and a central unit (CU); When the first transmission mode is a shared transmission mode or MRB transmission, and the second transmission mode is a dedicated transmission mode or DRB transmission, the base station triggers the establishment or binding of a core network tunnel related to the second transmission mode through the first terminal, including: the CU sending a first RRC signaling to the first terminal, the first RRC signaling being used to trigger the first terminal to establish the core network tunnel for the second transmission mode of the first multicast service; the CU receiving second indication information sent by the core network, the second indication information being used to indicate a first transmission channel between the core network and the CU, the first transmission channel being a transmission channel between the core network and the CU established by the core network according to the triggering of the first terminal for the second transmission mode of the first multicast service; the CU sending a first user context modification message for the first terminal to the DU according to the second indication information, and sending a second RRC signaling to the first terminal to establish a first DRB and switch the first multicast service of the first terminal from the current MRB to the first DRB; When the first transmission mode is a shared transmission mode or MRB, and the second transmission mode is a dedicated transmission mode or DRB, the base station directly requests the core network to establish or bind a core network tunnel related to the second transmission mode, including: the CU sending a first request message carrying first terminal identification information to the core network, the first request message requesting the core network to establish a second transmission channel between the core network and the CU for the second transmission mode of the first multicast service; the CU receiving a first response message carrying a first NAS message sent by the core network, the first NAS message being the NAS message sent to the core network when the first terminal initially accesses the first multicast service; the CU sending a second user context modification message for the first terminal to the DU, and sending a third RRC signaling to the first terminal to establish a first DRB, and converting the first multicast service of the first terminal from the current MRB to the first DRB.

2. The method as described in claim 1, characterized in that, The base station determines whether it needs to switch the transmission mode of the first multicast service of the first terminal, including: The DU determines whether it is necessary to switch the transmission mode of the first multicast service of the first terminal based on at least one of the channel quality indication, HARQ feedback information and transmission mode switching request message sent by the first terminal, and when it determines that the transmission mode needs to be switched, it sends the first indication information to the CU through the uplink signaling of the F1 interface to indicate the switch of transmission mode.

3. The method as described in claim 1, characterized in that, The base station determines whether it needs to switch the transmission mode of the first multicast service of the first terminal, including: The CU determines whether it is necessary to switch the transmission mode of the first multicast service of the first terminal based on at least one of the channel quality indication, HARQ feedback information and transmission mode switching request message of the first terminal reported by the DU.

4. The method as described in claim 2, characterized in that, When the first transmission mode is a shared transmission mode or MRB transmission, and the second transmission mode is a dedicated transmission mode or DRB transmission, the base station's direct request to the core network to establish or bind a core network tunnel related to the second transmission mode further includes: The CU stores the first NAS message sent to the core network when the first terminal initially accesses the first multicast service; When the CU sends the first request message, it also carries the first NAS message in the first request message.

5. The method as described in claim 4, characterized in that, Also includes: When the CU saves the first NAS message, it sets a corresponding timer and starts timing. When the CU receives the first indication information, it determines whether the timer has timed out: If the timer has not expired, then the first request message is sent; If the timer expires, a fourth RRC signaling is sent to the first terminal. The fourth RRC signaling is used to trigger the first terminal to establish the core network tunnel for the second transmission mode of the first multicast service. The CU receives a third indication information from the core network, which is used to indicate the second transmission channel between the core network and the CU. The second transmission channel is the transmission channel between the core network and the CU established by the core network according to the trigger of the first terminal for the second transmission mode of the first multicast service. The CU sends a third user context modification message for the first terminal to the DU, and sends a fifth RRC signaling to the first terminal to establish a first DRB and switch the first multicast service of the first terminal from the current MRB to the first DRB.

6. The method as described in claim 1, characterized in that, When the first transmission mode is a dedicated transmission mode or DRB, and the second transmission mode is a shared transmission mode or MRB, the base station triggers the establishment or binding of a core network tunnel related to the second transmission mode through the first terminal, including: If the current serving cell of the first terminal has established the MRB of the first multicast service, the CU sends a fourth user context modification message for the first terminal to the DU, so that the DU sends a sixth RRC signaling to the first terminal. The sixth RRC signaling is used to switch the first multicast service of the first terminal from the current DRB to the MRB. If the current serving cell of the first terminal has not established the MRB of the first multicast service, the CU sends a seventh RRC signaling to the first terminal. The seventh RRC signaling is used to instruct the first terminal to establish the MRB of the first multicast service and join the multicast group of the first multicast service through the multicast joining procedure.

7. The method as described in claim 1, characterized in that, When the transmission mode of the first multicast service of the first terminal is MRB, the method further includes: The CU receives terminal-related information of the first terminal reported by the DU. The terminal-related information is information related to the decision basis of the MRB transmission mode. The MRB transmission mode includes PTP and / or PTM. The CU determines whether to perform the MRB transmission mode conversion of the first multicast service of the first terminal based on the terminal-related information of the first terminal, and sends a fourth indication information to the DU to indicate the MRB transmission mode conversion when it determines that the MRB transmission mode conversion is required. The DU switches the MRB transmission mode of the first multicast service according to the fourth instruction information and sends a response message to the CU. The CU receives the response message and sends a seventh RRC signaling to the first terminal. The seventh RRC signaling is used to instruct the first terminal to switch the MRB transmission mode of the first multicast service.

8. The method as described in claim 7, characterized in that, The fourth indication information is also used to indicate at least one of the following: the RLC mode of the converted MRB transmission mode, and the retention time of the copy transmission; wherein the RLC mode includes an acknowledged mode and an unacknowledged mode; The response message is a downlink data transmission status message, or the response message is the user plane F1-U sequence number of the interface between the central unit and the distribution unit, which carries the data packet that was successfully sent to the lower layer in the MRB transmission mode before the conversion. The seventh RRC signaling carries the reset parameters of the terminal RLC receive window determined according to the RLC mode of the converted MRB transmission mode.

9. The method as described in claim 1, characterized in that, When the transmission mode of the first multicast service of the first terminal is MRB, the method further includes: Based on the terminal-related information of the first terminal, DU determines whether to perform the MRB transmission mode conversion of the first multicast service of the first terminal. The terminal-related information is the decision-making basis for the MRB transmission mode, and the MRB transmission mode includes PTP and / or PTM. When the DU determines that an MRB transmission mode switch is required, it sends a fifth indication message to the CU to indicate that an MRB transmission mode switch should be performed. The CU detects whether a GTP-U tunnel corresponding to the converted MRB transmission mode exists based on the fifth indication information. If it exists, a sixth indication message is sent to the DU and an eighth RRC signaling message is sent to the first terminal to switch the MRB transmission mode of the first multicast service of the first terminal; or, if it does not exist, the establishment process of the GTP-U tunnel corresponding to the converted MRB transmission mode is initiated. After the GTP-U tunnel is successfully established, a seventh indication message is sent to the DU and a ninth RRC signaling message is sent to the first terminal to switch the MRB transmission mode of the first multicast service of the first terminal.

10. A base station, characterized in that, include: The decision module is used to determine whether it is necessary to switch the transmission mode of the first multicast service of the first terminal. The transmission mode includes the following types: shared transmission mode or MRB transmission, and dedicated transmission mode or DRB transmission. The conversion processing module is used to, when it is necessary to convert the first multicast service from a first transmission mode to a second transmission mode, have the base station trigger the establishment or binding of a core network tunnel related to the second transmission mode through a first terminal, or have the base station directly request the core network to establish or bind a core network tunnel related to the second transmission mode; wherein, the core network tunnel refers to an end-to-end transmission channel between the first terminal and the core network. The base station includes a DU and a CU; When the first transmission mode is a shared transmission mode or MRB transmission, and the second transmission mode is a dedicated transmission mode or DRB transmission, and the conversion processing module is located in the CU: the conversion processing module is further configured to send a first RRC signaling to the first terminal when the establishment or binding of a core network tunnel related to the second transmission mode is triggered by the first terminal, the first RRC signaling being used to trigger the first terminal to establish the core network tunnel for the second transmission mode of the first multicast service; receive second indication information sent by the core network, the second indication information being used to indicate a first transmission channel between the core network and the CU, the first transmission channel being a transmission channel between the core network and the CU established by the core network for the second transmission mode of the first multicast service based on the triggering of the first terminal; send a first user context modification message for the first terminal to the DU according to the second indication information, and send a second RRC signaling to the first terminal to establish a first DRB corresponding to the current MRB of the first multicast service and convert the first multicast service of the first terminal from the current MRB to the first DRB; When the first transmission mode is a shared transmission mode or MRB transmission, and the second transmission mode is a dedicated transmission mode or DRB transmission, and the conversion processing module is located in the CU: the conversion processing module is further configured to, when directly requesting the core network to establish or bind a core network tunnel related to the second transmission mode, send a first request message carrying first terminal identification information to the core network, the first request message requesting the core network to establish a second transmission channel between the core network and the CU for the second transmission mode of the first multicast service; receive a first response message carrying a first NAS message sent by the core network, the first NAS message being the NAS message sent to the core network when the first terminal initially accesses the first multicast service; send a second user context modification message for the first terminal to the DU; and send a third RRC signaling to the first terminal to establish a first DRB and convert the first multicast service of the first terminal from the current MRB to the first DRB.

11. The base station as described in claim 10, characterized in that, The decision-making module is provided in the DU; The decision module is further configured to determine whether it is necessary to switch the transmission mode of the first multicast service of the first terminal based on at least one of the channel quality indication, HARQ feedback information and transmission mode switching request message sent by the first terminal, and when it is determined that the transmission mode needs to be switched, send first indication information to the CU through F1 interface uplink signaling to indicate the switching of transmission mode.

12. The base station as described in claim 10, characterized in that, The decision-making module is provided in the CU; The decision module is further configured to determine whether it is necessary to switch the transmission mode of the first multicast service of the first terminal based on at least one of the channel quality indication, HARQ feedback information and transmission mode conversion request message of the first terminal reported by the DU.

13. The base station as described in claim 11, characterized in that, When the first transmission mode is a shared transmission mode or MRB transmission, and the second transmission mode is a dedicated transmission mode or DRB transmission, and the conversion processing module is located in the CU, when the base station directly requests the core network to establish or bind a core network tunnel related to the second transmission mode, the base station further includes: The storage module is used to store the first NAS message sent to the core network when the first terminal initially accesses the first multicast service; When sending the first request message, the conversion processing module also carries the first NAS message in the first request message.

14. The base station as described in claim 13, characterized in that, Also includes: The timing module is used to set a corresponding timer and start timing when saving the first NAS message; The conversion processing module is further configured to determine whether the timer has timed out upon receiving the first indication information: If the timer has not expired, then the first request message is sent; If the timer expires, a fourth RRC signaling is sent to the first terminal. The fourth RRC signaling is used to trigger the first terminal to establish the core network tunnel for the second transmission mode of the first multicast service. The CU receives a third indication information from the core network, which is used to indicate the second transmission channel between the core network and the CU. The second transmission channel is the transmission channel between the core network and the CU established by the core network according to the trigger of the first terminal for the second transmission mode of the first multicast service. The CU sends a third user context modification message for the first terminal to the DU, and sends a fifth RRC signaling to the first terminal to establish a first DRB and switch the first multicast service of the first terminal from the current MRB to the first DRB.

15. The base station as described in claim 10, characterized in that, When the first transmission mode is a dedicated transmission mode or DRB, the second transmission mode is a shared transmission mode or MRB, and the conversion processing module is located in the CU: The conversion processing module is also used when the establishment or binding of the core network tunnel related to the second transmission mode is triggered by the first terminal: If the current serving cell of the first terminal has established the MRB of the first multicast service, the CU sends a fourth user context modification message for the first terminal to the DU, so that the DU sends a sixth RRC signaling to the first terminal. The sixth RRC signaling is used to switch the first multicast service of the first terminal from the current DRB to the MRB. If the current serving cell of the first terminal has not established the MRB of the first multicast service, the CU sends a seventh RRC signaling to the first terminal. The seventh RRC signaling is used to instruct the first terminal to establish the MRB of the first multicast service and join the multicast group of the first multicast service through the multicast joining procedure.

16. The base station as described in claim 10, characterized in that, The decision-making module is provided in the CU; The decision module is further configured to receive terminal-related information of the first terminal reported by the DU when the transmission mode of the first multicast service of the first terminal is MRB. The terminal-related information is information related to the decision basis of the MRB transmission mode, and the MRB transmission mode includes PTP and / or PTM. Based on the terminal-related information of the first terminal, the module determines whether to perform the MRB transmission mode conversion of the first multicast service of the first terminal, and when it is determined that the MRB transmission mode conversion needs to be performed, the module sends a fourth indication information to the DU to indicate the MRB transmission mode conversion. The DU is used to switch the MRB transmission mode of the first multicast service according to the fourth indication information and send a response message to the CU; The CU is used to receive the response message and send a seventh RRC signaling to the first terminal. The seventh RRC signaling is used to instruct the first terminal to switch the MRB transmission mode of the first multicast service.

17. The base station as described in claim 16, characterized in that, The fourth indication information is also used to indicate at least one of the following: the RLC mode of the converted MRB transmission mode, and the retention time of the copy transmission; wherein the RLC mode includes an acknowledged mode and an unacknowledged mode; The response message is a downlink data transmission status message, or the response message is the maximum F1-U sequence number of the data packet that was successfully sent to the lower layer in the MRB transmission mode before the conversion. The seventh RRC signaling carries the reset parameters of the terminal RLC receive window determined according to the RLC mode of the converted MRB transmission mode.

18. The base station as described in claim 10, characterized in that, The decision-making module is provided in the DU; The decision module is further configured to determine whether to perform an MRB transmission mode conversion for the first multicast service of the first terminal based on the terminal-related information of the first terminal, wherein the terminal-related information is information related to the decision basis of the MRB transmission mode, and the MRB transmission mode includes PTP and / or PTM; when it is determined that an MRB transmission mode conversion is required, a fifth indication message is sent to the CU to indicate that an MRB transmission mode conversion should be performed. The CU is used to detect whether a GTP-U tunnel corresponding to the converted MRB transmission mode exists according to the fifth indication information. If it exists, the CU sends a sixth indication information to the DU and an eighth RRC signaling to the first terminal to convert the MRB transmission mode of the first multicast service of the first terminal. If it does not exist, the CU initiates the establishment process of the GTP-U tunnel corresponding to the converted MRB transmission mode. After the GTP-U tunnel is successfully established, the CU sends a seventh indication information to the DU and a ninth RRC signaling to the first terminal to convert the MRB transmission mode of the first multicast service of the first terminal.

19. A base station, characterized in that, include: A processor, a memory, and a program stored in the memory and executable on the processor, wherein the program, when executed by the processor, implements the steps of the method as claimed in any one of claims 1 to 9.

20. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the method as described in any one of claims 1 to 9.

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