A Retransmission Method and Apparatus for Multicast Services, a Terminal Device, and a Network Device

Abstract

An embodiment of the present application provides a retransmission method and apparatus for multicast services, a terminal device, and a network device. The method includes: The terminal device generates an RLC status report for receiving multicast service data, and sends the RLC status report to the network device. The RLC status report is used for the network device to determine the RLC PDUs that need to be retransmitted; The terminal device receives the RLC PDUs retransmitted by the network device in a unicast manner.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of mobile communication technologies, and particularly to a method and apparatus for retransmitting multicast services, a terminal device, and a network device. Background Art

[0002] In a New Radio (NR) system, higher requirements are put forward for the reliability of multicast services, and it is required that the terminal device feeds back the reception of multicast services. However, the current feedback mechanism has the following problems: If there are multiple users receiving a multicast service data and only one of them receives it incorrectly, multicast retransmission of the multicast service data is redundant and power-consuming for other users. Therefore, how to perform efficient retransmission is a problem to be solved. Summary of the Invention

[0003] The embodiments of the present application provide a method and apparatus for retransmitting multicast services, a terminal device, and a network device.

[0004] The method for retransmitting multicast services provided by the embodiments of the present application includes:

[0005] A terminal device generates a Radio Link Control (RLC) status report for receiving multicast service data, and sends the RLC status report to a network device, where the RLC status report is used for the network device to determine a Radio Link Control Packet Data Unit (RLC PDU) that needs to be retransmitted;

[0006] The terminal device receives the RLC PDU retransmitted by the network device in a unicast manner.

[0007] The method for retransmitting multicast services provided by the embodiments of the present application includes:

[0008] A network device receives an RLC status report sent by a terminal device, where the RLC status report is an RLC status report generated by the terminal device for receiving multicast service data, and the RLC status report is used for the network device to determine an RLC PDU that needs to be retransmitted;

[0009] The network device retransmits the RLC PDU to the terminal device in a unicast manner.

[0010] The apparatus for retransmitting multicast services provided by the embodiments of the present application is applied to a terminal device, and the apparatus includes:

[0011] A generating unit, configured to generate an RLC status report for receiving multicast service data;

[0012] A sending unit, configured to send the RLC status report to a network device, where the RLC status report is used for the network device to determine RLC PDUs that need to be retransmitted;

[0013] A receiving unit, configured to receive the RLC PDUs retransmitted by the network device in a unicast manner.

[0014] The retransmission device for multicast services provided by an embodiment of the present application is applied to a network device, and the device includes:

[0015] A receiving unit, configured to receive an RLC status report sent by a terminal device, where the RLC status report is an RLC status report generated by the terminal device for receiving multicast service data, and the RLC status report is used for the network device to determine RLC PDUs that need to be retransmitted;

[0016] A sending unit, configured to retransmit RLC PDUs to the terminal device in a unicast manner.

[0017] The terminal device provided by an embodiment of the present application includes a processor and a memory. The memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the retransmission method for multicast services described above.

[0018] The network device provided by an embodiment of the present application includes a processor and a memory. The memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the retransmission method for multicast services described above.

[0019] The chip provided by an embodiment of the present application is used to implement the retransmission method for multicast services described above.

[0020] Specifically, the chip includes: a processor, configured to call and run a computer program from a memory, so that a device installed with the chip executes the retransmission method for multicast services described above.

[0021] The computer-readable storage medium provided by an embodiment of the present application is used to store a computer program, and the computer program enables a computer to execute the retransmission method for multicast services described above.

[0022] The computer program product provided by an embodiment of the present application includes computer program instructions, and the computer program instructions enable a computer to execute the retransmission method for multicast services described above.

[0023] The computer program provided by an embodiment of the present application, when running on a computer, enables the computer to execute the retransmission method for multicast services described above.

[0024] With the above technical solution, the terminal device feeds back the RLC status report to the network device, so that the network device can determine the RLC PDUs that need to be retransmitted according to the RLC status report, and retransmit the RLC PDUs to the terminal device in a unicast manner, avoiding redundant reception of the RLC PDUs by other terminal devices, achieving the purpose of energy saving and efficient feedback, and improving the reliability of multicast service reception. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the present application, and constitute a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application, and do not constitute an improper limitation of the present application. In the drawings:

[0026] Figure 1 is a schematic diagram of a communication system architecture provided by an embodiment of the present application;

[0027] Figure 2 is a schematic flowchart of a retransmission method for a multicast service provided by an embodiment of the present application;

[0028] Figure 3 is a schematic diagram of the protocol stacks of a terminal device and a network device provided by an embodiment of the present application Figure 1 ;

[0029] Figure 4 is a schematic diagram of the protocol stacks of a terminal device and a network device provided by an embodiment of the present application Figure 2 ;

[0030] Figure 5 is a schematic diagram of the structural composition of a retransmission device for a multicast service provided by an embodiment of the present application Figure 1 ;

[0031] Figure 6 is a schematic diagram of the structural composition of a retransmission device for a multicast service provided by an embodiment of the present application Figure 2 ;

[0032] Figure 7 is a schematic structural diagram of a communication device provided by an embodiment of the present application;

[0033] Figure 8 is a schematic structural diagram of a chip provided by an embodiment of the present application;

[0034] Figure 9 is a schematic block diagram of a communication system provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] Next, the technical solutions in the embodiments of the present application will be described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0036] The technical solutions in the embodiments of the present application can be applied to various communication systems, such as: Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD) systems, 5G communication systems, or future communication systems, etc.

[0037] Exemplarily, the communication system 100 to which the embodiments of the present application are applied is as Figure 1 shown. The communication system 100 may include a network device 110, and the network device 110 may be a device that communicates with a terminal 120 (or referred to as a communication terminal, terminal). The network device 110 can provide communication coverage for a specific geographical area and can communicate with terminals located within the coverage area. Optionally, the network device 110 may be an evolved Node B (eNB or eNodeB) in an LTE system, or a radio controller in a Cloud Radio Access Network (CRAN), or the network device may be a mobile switching center, a relay station, an access point, a vehicle-mounted device, a wearable device, a hub, a switch, a bridge, a router, a network-side device in a 5G network, or a network device in a future communication system, etc.

[0038] The communication system 100 further includes at least one terminal 120 within the coverage area of the network device 110. As used herein, "terminal" includes, but is not limited to, being connected via a wired line, such as via a Public Switched Telephone Networks (PSTN), Digital Subscriber Line (DSL), digital cable, direct cable connection; and / or another data connection / network; and / or via a wireless interface, such as, for a cellular network, Wireless Local Area Network (WLAN), digital television network such as a DVB-H network, satellite network, AM-FM broadcast transmitter; and / or a device of another terminal that is configured to receive / transmit communication signals; and / or an Internet of Things (IoT) device. A terminal configured to communicate via a wireless interface may be referred to as a "wireless communication terminal", "wireless terminal" or "mobile terminal". Examples of mobile terminals include, but are not limited to, satellite or cellular telephones; Personal Communications System (PCS) terminals that may combine cellular radiotelephone with data processing, facsimile, and data communication capabilities; PDAs that may include radiotelephones, pagers, Internet / intranet access, Web browsers, notepads, calendars, and / or Global Positioning System (GPS) receivers; and conventional laptop and / or palmtop receivers or other electronic devices that include radiotelephone transceivers. A terminal may refer to an access terminal, User Equipment (UE), user unit, user station, mobile station, mobile device, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user device. An access terminal may be a cellular phone, cordless phone, Session Initiation Protocol (SIP) phone, Wireless Local Loop (WLL) station, Personal Digital Assistant (PDA), handheld device with wireless communication capabilities, computing device, or other processing device connected to a wireless modem, in-vehicle device, wearable device, a terminal in a 5G network, or a terminal in a future evolved PLMN, etc.

[0039] Optionally, Device to Device (D2D) communication may be performed between the terminals 120.

[0040] Optionally, the 5G communication system or 5G network may also be referred to as a New Radio (NR) system or NR network.

[0041] Figure 1 Exemplarily, a network device and two terminals are shown. Optionally, the communication system 100 may include multiple network devices, and the coverage range of each network device may include other numbers of terminals. This application does not limit this.

[0042] Optionally, the communication system 100 may also include other network entities such as a network controller and a mobility management entity. This application does not limit this in the embodiments.

[0043] It should be understood that in the embodiments of this application, a device with communication functions in a network / system may be referred to as a communication device. Taking Figure 1 the shown communication system 100 as an example, the communication devices may include a network device 110 and a terminal 120 with communication functions. The network device 110 and the terminal 120 may be the specific devices described above and will not be elaborated here; the communication devices may also include other devices in the communication system 100, such as other network entities such as a network controller and a mobility management entity. This application does not limit this in the embodiments.

[0044] It should be understood that the terms "system" and "network" are often used interchangeably in this article. The term " / and" in this article is merely a description of the association relationship between associated objects, indicating that there can be three relationships. For example, A and / or B may indicate: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0045] To facilitate understanding of the technical solutions of the embodiments of this application, the following explains the technical solutions related to the embodiments of this application.

[0046] With the pursuit of rate, latency, high-speed mobility, energy efficiency by people and the diversity and complexity of services in future life, for this reason, the 3rd rd Generation Partnership Project (3GPP) international standard organization began to research and develop 5G. The main application scenarios of 5G are: enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC).

[0047] On the one hand, eMBB still aims at users' access to multimedia content, services and data, and its demand is growing very rapidly. On the other hand, since eMBB may be deployed in different scenarios, such as indoors, urban areas, rural areas, etc., there are significant differences in its capabilities and requirements. Therefore, it cannot be generalized and must be analyzed in detail in combination with specific deployment scenarios. Typical applications of URLLC include industrial automation, power automation, remote medical operations (surgery), traffic safety assurance, etc. Typical features of mMTC include high connection density, small data volume, latency-insensitive services, low cost of modules and long service life, etc.

[0048] In the early deployment of NR, it was difficult to obtain complete NR coverage. Therefore, the typical network coverage was a wide-area LTE coverage and an NR island coverage mode. Moreover, a large number of LTEs were deployed below 6 GHz, and there was little spectrum below 6 GHz available for 5G. Therefore, NR must study the spectrum application above 6 GHz, but the high-frequency band coverage is limited and the signal fades quickly. At the same time, in order to protect the mobile operators' previous investment in LTE, a tight interworking mode between LTE and NR was proposed.

[0049] MBMS

[0050] MBMS is a technology for transmitting data from one data source to multiple terminal devices by sharing network resources. This technology can effectively utilize network resources while providing multimedia services, and achieve the broadcast and multicast of multimedia services at a relatively high rate (such as 256 kbps).

[0051] Since the spectrum efficiency of MBMS is relatively low and it is not sufficient to effectively carry and support the operation of mobile TV type services. Therefore, in LTE, 3GPP clearly proposed to enhance the support ability for downlink high-speed MBMS services and determined the design requirements for the physical layer and air interface.

[0052] 3GPP R9 introduced evolved MBMS (eMBMS) into LTE. eMBMS proposed the concept of a single frequency network (SFN), that is, a multimedia broadcast multicast service single frequency network (MBSFN). MBSFN uses a unified frequency to send service data simultaneously in all cells, but it is necessary to ensure the synchronization between cells. This method can greatly improve the overall signal-to-noise ratio distribution of the cell, and the spectrum efficiency will also be correspondingly increased significantly. eMBMS realizes the broadcast and multicast of services based on the IP multicast protocol.

[0053] In LTE or enhanced LTE (LTE-Advanced, LTE-A), MBMS only has a broadcast bearer mode and no multicast bearer mode. In addition, the reception of MBMS services is applicable to terminal devices in the idle state or the connected state.

[0054] The concept of Single Cell Point To Multiploint (SC-PTM) was introduced in 3GPP R13, and SC-PTM is based on the MBMS network architecture.

[0055] MBMS introduced new logical channels, including the Single Cell-Multicast Control Channel (SC-MCCH) and the Single Cell-Multicast Transport Channel (SC-MTCH). SC-MCCH and SC-MTCH are mapped to the Downlink-Shared Channel (DL-SCH), and further, DL-SCH is mapped to the Physical Downlink Shared Channel (PDSCH). Among them, SC-MCCH and SC-MTCH belong to logical channels, DL-SCH belongs to transport channels, and PDSCH belongs to physical channels. SC-MCCH and SC-MTCH do not support Hybrid Automatic Repeat reQuest (HARQ) operations.

[0056] MBMS introduces a new type of System Information Block (SIB), namely SIB20. Specifically, the configuration information of the SC-MCCH is transmitted through SIB20, and there is only one SC-MCCH in a cell. The configuration information of the SC-MCCH includes: the modification period of the SC-MCCH, the repetition period of the SC-MCCH, and information such as the radio frame and subframe scheduling the SC-MCCH. Further, 1) the boundary of the modification period of the SC-MCCH satisfies SFN mod m = 0, where SFN represents the system frame number of the boundary, and m is the modification period of the SC-MCCH configured in SIB20 (i.e., sc-mcch-ModificationPeriod). 2) The radio frame scheduling the SC-MCCH satisfies: SFN mod mcch-RepetitionPeriod = mcch-Offset, where SFN represents the system frame number of the radio frame, mcch-RepetitionPeriod represents the repetition period of the SC-MCCH, and mcch-Offset represents the offset of the SC-MCCH. 3) The subframe scheduling the SC-MCCH is indicated by sc-mcch-Subframe.

[0057] The SC-MCCH is scheduled through the Physical Downlink Control Channel (PDCCH). On the one hand, a new Radio Network Tempory Identity (RNTI), namely the Single Cell RNTI (SC-RNTI), is introduced to identify the PDCCH (such as SC-MCCH PDCCH) used to schedule the SC-MCCH. Optionally, the SC-RNTI is fixedly set to FFFC. On the other hand, a new RNTI, namely the Single Cell Notification RNTI (SC-N-RNTI), is introduced to identify the PDCCH (such as the notification PDCCH) used to indicate the change notification of the SC-MCCH. Optionally, the SC-N-RNTI is fixedly set to FFFB; further, one bit of the 8 bits of DCI 1C can be used to indicate the change notification. In LTE, the configuration information of SC-PTM is based on the SC-MCCH configured in SIB20, and then the SC-MCCH configures the SC-MTCH, and the SC-MTCH is used to transmit service data.

[0058] Specifically, the SC-MCCH only transmits one message (i.e., SCPTMConfiguration), which is used to configure the configuration information of SC-PTM. The configuration information of SC-PTM includes: Temporary Mobile Group Identity (TMGI), session id, Group RNTI (G-RNTI), Discontinuous Reception (DRX) configuration information, and SC-PTM service information of neighboring cells, etc. It should be noted that SC-PTM in R13 does not support the Robust Header Compression (ROHC) function.

[0059] The downlink discontinuous reception of SC-PTM is controlled by the following parameters: onDurationTimerSCPTM, drx-InactivityTimerSCPTM, SC-MTCH-SchedulingCycle, and SC-MTCH-SchedulingOffset.

[0060] When [(SFN * 10) + subframe number] modulo (SC-MTCH-SchedulingCycle) = SC-MTCH-SchedulingOffset is satisfied, the timer onDurationTimerSCPTM is started;

[0061] When a downlink PDCCH scheduling is received, the timer drx-InactivityTimerSCPTM is started;

[0062] The downlink SC-PTM service is received only when the timer onDurationTimerSCPTM or drx-InactivityTimerSCPTM is running.

[0063] The service continuity of SC-PTM adopts the MBMS service continuity concept based on SIB15, that is, the "SIB15 + MBMSInterestIndication" method. The service continuity of idle terminal devices is based on the concept of frequency priority.

[0064] It should be noted that the MBMS services in the above solutions include but are not limited to multicast services and groupcast services. In the embodiments of this application, the multicast service is taken as an example for description, and the description of "multicast service" can also be replaced by "MBS service" or "groupcast service" or "MBMS service".

[0065] In NR, the RLC AM mode has a feedback mechanism. The data receiving end feeds back the reception status of the RLC PDU as correct reception or incorrect reception through the RLC status report. If it is correct reception, the RLC status report indicates that the feedback information for the SN corresponding to the RLC PDU is ACK information. If it is incorrect reception, the RLC status report indicates that the feedback information for the SN corresponding to the RLC PDU is NACK information. It should be noted that the RLC status report can indicate the feedback information for the SN corresponding to one or more RLC PDUs. The data sending end can re-transmit the RLC PDU corresponding to the SN number with NACK information as the feedback information according to the RLC status report.

[0066] In the NR system, multicast services need to be received in the RRC connected state, and higher requirements are put forward for the reliability of multicast services. The terminal device needs to feed back the reception of multicast services. How to ensure the reliability of multicast services without causing redundant re-transmissions of the multicast mode and reducing the impact on the terminal devices that have correctly received the data is a problem that needs to be solved. For this reason, the following technical solutions of the embodiments of the present application are proposed.

[0067] Figure 2 It is a schematic flowchart of the re-transmission method for multicast services provided by the embodiments of the present application, as Figure 2 shown, the re-transmission method for multicast services includes the following steps:

[0068] Step 201: The terminal device generates an RLC status report for the reception of multicast service data, sends the RLC status report to the network device, and the network device receives the RLC status report sent by the terminal device. The RLC status report is used for the network device to determine the RLC PDU that needs to be re-transmitted.

[0069] In the embodiments of the present application, the terminal device has a first RLC entity and a fourth RLC entity. Among them, the first RLC entity belongs to the PTM RLC entity, and the fourth RLC entity belongs to the PTP RLC entity.

[0070] In the embodiments of the present application, the network device can be a base station, such as a gNB. The network device has a second RLC entity and a third RLC entity. Among them, the second RLC entity belongs to the PTM RLC entity, and the third RLC entity belongs to the PTP RLC entity.

[0071] It should be noted that the PTM RLC entity refers to the RLC entity that receives and / or sends data through multicast. The PTP RLC entity refers to the RLC entity that receives and / or sends data through unicast. For the case of receiving and / or sending data through multicast, the scheduling information of the data is scrambled by the G-RNTI. For the case of receiving and / or sending data through unicast, the scheduling information of the data is scrambled by the C-RNTI.

[0072] In the embodiment of the present application, the RLC status report is the RLC status report generated by the terminal device for receiving multicast service data. Before the terminal device generates the RLC status report for receiving multicast service data, the method further includes:

[0073] The second RLC entity of the network device sends multicast service data to the first RLC entity of the terminal device, and the first RLC entity of the terminal device receives the multicast service data sent by the second RLC entity of the network device, where the scheduling information of the multicast service data is scrambled by the G-RNTI.

[0074] Here, since the first RLC entity and the second RLC entity belong to the PTM RLC entity, the terminal device receives the multicast service data sent by the network device through multicast.

[0075] In the embodiment of the present application, the terminal device generates an RLC status report for receiving multicast service data based on the reception situation of the multicast service data. Here, the reception situation of the multicast service data may be correctly receiving the multicast service data or incorrectly receiving the multicast service data. If the multicast service data is correctly received, the RLC status report indicates that the feedback information of the SN corresponding to the multicast service data is ACK information. If the multicast service data is incorrectly received, the RLC status report indicates that the feedback information of the SN corresponding to the multicast service data is NACK information. It should be noted that the RLC status report may indicate the feedback information of the SN corresponding to one or more multicast service data.

[0076] In the embodiment of the present application, the terminal device sends the RLC status report to the network device, which can be achieved in the following ways.

[0077] Method 1: The RLC status report is sent to the second RLC entity of the network device.

[0078] The first RLC entity of the terminal device generates an RLC status report for receiving multicast service data, sends the RLC status report to the second RLC entity of the network device, and the second RLC entity of the network device receives the RLC status report sent by the first RLC entity of the terminal device.

[0079] Here, the RLC status report is an RLC status report for multicast service data reception generated by a first RLC entity of the terminal device.

[0080] Here, it should be noted that although the first RLC entity and the second RLC entity belong to PTM RLC entities, the terminal device still reports its own RLC status report to the network device in a unicast manner. That is to say, the scheduling information corresponding to the RLC status report is scrambled by C-RNTI.

[0081] In an embodiment of the present application, the RLC status report is used for a second RLC entity of the network device to send RLC PDUs corresponding to at least one SN to a third RLC entity of the network device, where the at least one SN is the SN corresponding to the NACK feedback information indicated by the RLC status report, and the third RLC entity belongs to a PTP RLC entity.

[0082] Specifically, the second RLC entity of the network device determines the SN corresponding to the NACK feedback information based on the RLC status report, obtains at least one SN, and sends the RLC PDUs corresponding to the at least one SN to the third RLC entity of the network device. Then, step 202 is executed.

[0083] In an embodiment of the present application, the network device sends first configuration information to the terminal device, and the terminal device receives the first configuration information sent by the network device. The first configuration information is used to determine the protocol stack configuration for multicast reception and / or the protocol stack configuration for unicast reception; wherein, the protocol stack configuration for multicast reception is used to determine that the mode of the first RLC entity of the terminal device is the AM mode; the protocol stack configuration for unicast reception is used to determine that the mode of the fourth RLC entity of the terminal device is the AM mode. Further, optionally, the first configuration information includes second indication information, and the second indication information is used to indicate that the bearer corresponding to the first RLC entity is only used for downlink data reception.

[0084] Here, the AM mode represents the acknowledged mode. For the AM mode, because of the ARQ capability, if the data receiving end (such as the terminal device) incorrectly receives an RLC PDU, it notifies the data sending end (i.e., the network device) to retransmit the RLC PDU. Here, the RLC PDU contains an SN.

[0085] Method 2: The RLC status report is sent to the third RLC entity of the network device.

[0086] The first RLC entity of the terminal device generates an RLC status report for multicast service data reception, and sends the RLC status report to the fourth RLC entity of the terminal device; the fourth RLC entity of the terminal device sends the RLC status report to the third RLC entity of the network device. The third RLC entity of the network device receives the RLC status report sent by the fourth RLC entity of the terminal device.

[0087] Here, the RLC status report is an RLC status report for multicast service data reception generated by the first RLC entity of the terminal device, and the RLC status report is sent by the first RLC entity of the terminal device to the fourth RLC entity of the terminal device.

[0088] Here, the first RLC entity belongs to the PTM RLC entity, and the third RLC entity and the fourth RLC entity belong to the PTP RLC entity. The terminal device reports its RLC status report to the network device in a unicast manner. That is to say, the scheduling information corresponding to the RLC status report is scrambled by C-RNTI.

[0089] In the embodiment of the present application, after receiving the RLC status report sent by the fourth RLC entity of the terminal device, the third RLC entity of the network device sends the first indication information or the RLC status report to the second RLC entity of the network device, where the first indication information is used to indicate the SN corresponding to the NACK feedback information and / or the SN corresponding to the ACK information, and the first indication information is determined based on the RLC status report; the first indication information or the RLC status report is used for the second RLC entity of the network device to send the RLC PDUs corresponding to at least one SN to the third RLC entity of the network device, and the at least one SN is the SN corresponding to the NACK feedback information indicated by the first indication information or the RLC status report; where the second RLC entity belongs to the PTM RLC entity.

[0090] Specifically, the second RLC entity of the network device determines the SN corresponding to the NACK feedback information based on the first indication information or the RLC status report, obtains at least one SN, and sends the RLC PDUs corresponding to the at least one SN to the third RLC entity of the network device. Then, step 202 is executed.

[0091] In an embodiment of the present application, the network device sends first configuration information to the terminal device, and the terminal device receives the first configuration information sent by the network device. The first configuration information is used to determine the protocol stack configuration for multicast reception and / or the protocol stack configuration for unicast reception. Among them, the protocol stack configuration for multicast reception is used to determine that the mode of the first RLC entity of the terminal device is the AM mode or the UM mode; the protocol stack configuration for unicast reception is used to determine that the mode of the fourth RLC entity of the terminal device is the AM mode. Further, optionally, the first configuration information includes second indication information, and the second indication information is used to indicate that the bearer corresponding to the first RLC entity is only used for downlink data reception.

[0092] Here, the AM mode represents the acknowledged mode. The UM mode represents the unacknowledged mode. For the UM mode, the retransmission protocol is not used.

[0093] Step 202: The network device retransmits the RLC PDU to the terminal device in unicast mode, and the terminal device receives the RLC PDU retransmitted by the network device in unicast mode.

[0094] In an embodiment of the present application, after the above steps, the third RLC entity of the network device receives the RLC PDUs corresponding to at least one SN sent by the second RLC entity of the network device. These RLC PDUs are the RLC PDUs that need to be retransmitted to the terminal device. Therefore,

[0095] The third RLC entity of the network device sends the RLC PDUs corresponding to the at least one SN to the fourth RLC entity of the terminal device, and the fourth RLC entity of the terminal device receives the RLC PDUs corresponding to the at least one SN sent by the third RLC entity of the network device and sends the RLC PDUs corresponding to the at least one SN to the first RLC entity of the terminal device (that is, the RLC PDUs corresponding to the at least one SN are sent by the fourth RLC entity of the terminal device to the first RLC entity of the terminal device).

[0096] Further, in an optional manner, the first RLC entity of the terminal device adjusts the reception window based on the received RLC PDUs corresponding to the at least one SN.

[0097] In the above technical solution of the embodiment of the present application, since the network device retransmits the RLC PDU to the terminal device by retransmitting the RLC PDU from the PTP RLC entity of the network device to the PTP RLC entity of the terminal device, it is a retransmission of multicast service data in a unicast manner, avoiding affecting other terminal devices that have correctly received the multicast service data. Optionally, before retransmitting the multicast service data in a unicast manner, the multicast service data can also be retransmitted in a multicast manner. In this case, the number of retransmissions in the multicast manner needs to be restricted. Specifically, if the number of retransmissions in the multicast manner exceeds the specified threshold, the transmission of the multicast service data is changed to the unicast manner.

[0098] Among them, retransmitting the multicast service data in a multicast manner means that the PTM RLC entity of the network device retransmits the RLC PDU to the PTM RLC entity of the terminal device. The specific details of transmitting the multicast service data in a unicast manner can refer to the description of the foregoing solution, that is, the PTP RLC entity of the network device retransmits the RLC PDU to the PTP RLC entity of the terminal device.

[0099] It should be noted that each RLC entity is associated with an RLC ID. For a terminal device, if the PTM RLC entity of the terminal device sends the RLC status report to the PTM RLC entity of the network device (i.e., the first method in the above solution), the PTM RLC entity of the terminal device first sends the RLC status report to the MAC entity, and the MAC entity multiplexes the RLC status report with other information at the MAC layer and associates the RLC status report with the RLC ID of the PTM RLC entity of the terminal device. If the PTP RLC entity of the terminal device sends the RLC status report to the PTP RLC entity of the network device (i.e., the second method in the above solution), the PTP RLC entity of the terminal device first sends the RLC status report to the MAC entity, and the MAC entity multiplexes the RLC status report with other information at the MAC layer and associates the RLC status report with the RLC ID of the PTP RLC entity of the terminal device.

[0100] In the embodiment of the present application, the network device determines the RLC PDU that needs to be retransmitted to the terminal device based on the RLC status report reported by the terminal device. The RLC PDU retransmitted to the terminal device is the RLC PDU that the terminal device has not correctly received (i.e., erroneously received). Without limitation, the network device can also obtain relevant information (such as the SN of the RLC PDU that needs to be retransmitted) about the RLC PDU that needs to be retransmitted from other devices (such as other terminal devices), and then determine the RLC PDU that needs to be retransmitted based on this information.

[0101] The technical solutions of the embodiments of the present application will be illustrated below with specific application examples.

[0102] Application Example 1

[0103] Refer to Figure 3 , the PTM RLC entity of the terminal device has the AM mode, the PTP RLC entity of the terminal device has the AM mode, the PTM RLC entity of the network device has the AM mode, and the PTP RLC entity of the network device has the AM mode.

[0104] The terminal device receives first configuration information sent by the network device, and the first configuration information is used to configure the protocol stack configuration for multicast reception and the protocol stack configuration for unicast reception. Among them, in the protocol stack configuration for multicast reception, the PTM RLC entity of the terminal device has the AM mode. Optionally, the first configuration information includes second indication information, and the second indication information is used to indicate that the bearer corresponding to the PTM RLC entity of the terminal device is only used for downlink data reception.

[0105] The terminal device receives multicast service data through the G-RNTI. Specifically, refer to Figure 3 , the PTM RLC entity of the terminal device receives the multicast service data sent by the PTM RLC entity of the network device. If the RLC status report is triggered, the PTM RLC entity of the terminal device generates an RLC status report and delivers it to the MAC entity, and then sends it to the network device through the PHY entity. After receiving the RLC status report, the PTM RLC entity of the network device sends the RLC PDU corresponding to the SN corresponding to the NACK information indicated in the RLC status report to the PTP RLC entity of the network device to trigger the retransmission of the RLC PDU. The PTP RLC entity of the terminal device receives the retransmitted RLC PDU from the PTP RLC entity of the network device and sends the RLC PDU to the PTM RLC entity of the terminal device. The PTM RLC entity of the terminal device adjusts the reception window based on the received RLC PDU.

[0106] Application Example 2

[0107] Refer to Figure 4 , the PTM RLC entity of the terminal device has the AM mode or the UM mode, the PTP RLC entity of the terminal device has the AM mode, the PTM RLC entity of the network device has the AM mode or the UM mode, and the PTP RLC entity of the network device has the AM mode.

[0108] The terminal device receives first configuration information sent by a network device, where the first configuration information is used to configure the protocol stack configuration for multicast reception and the protocol stack configuration for unicast reception. Among them, in the protocol stack configuration for multicast reception, the PTM RLC entity of the terminal device has the AM mode or the UM mode. Optionally, the first configuration information includes second indication information, where the second indication information is used to indicate that the bearer corresponding to the PTM RLC entity of the terminal device is only used for downlink data reception.

[0109] The terminal device receives multicast service data through the G-RNTI. Specifically, referring to Figure 3 , the PTM RLC entity of the terminal device receives the multicast service data sent by the PTM RLC entity of the network device. If the RLC status report reporting is triggered, the PTM RLC entity of the terminal device generates an RLC status report and sends it to the PTP RLC entity of the terminal device. The PTP RLC entity of the terminal device delivers the RLC status report to the MAC entity, and then sends it to the network device through the PHY entity. After receiving the RLC status report, the PTP RLC entity of the network device forwards the first indication information or the status report to the PTM RLC entity of the network device. The PTM RLC entity of the network device adjusts the RLC transmission window based on the RLC status reports of all users within the multicast group or the first indication information, and sends the RLC PDU corresponding to the SN of the NACK information to the PTP RLC entity of the network device, triggering the retransmission of the RLC PDU. The PTP RLC entity of the terminal device receives the retransmitted RLC PDU from the PTP RLC entity of the network device and sends the RLC PDU to the PTM RLC entity of the terminal device. The PTM RLC entity of the terminal device adjusts the reception window based on the received RLC PDU.

[0110] Figure 5 is a schematic structural composition of the retransmission device for multicast services provided by an embodiment of the present application Figure 1 , applied to a terminal device, as Figure 5 shown, the retransmission device for multicast services includes:

[0111] A generation unit 501, configured to generate an RLC status report for receiving multicast service data;

[0112] A sending unit 502, configured to send the RLC status report to the network device, where the RLC status report is used for the network device to determine the RLC PDU that needs to be retransmitted;

[0113] A receiving unit 503, configured to receive the RLC PDU retransmitted by the network device in a unicast manner.

[0114] In an alternative manner, the terminal device has a first RLC entity;

[0115] The generating unit 501 is configured to generate an RLC status report for multicast service data reception through the first RLC entity of the terminal device;

[0116] The sending unit 502 is configured to send the RLC status report to a second RLC entity of the network device through the first RLC entity of the terminal device;

[0117] Wherein, the first RLC entity and the second RLC entity belong to PTM RLC entities.

[0118] In an alternative manner, the RLC status report is used for the second RLC entity of the network device to send RLC PDUs corresponding to at least one SN to a third RLC entity of the network device, where the at least one SN is the SN corresponding to the NACK feedback information indicated by the RLC status report, and the third RLC entity belongs to a PTP RLC entity.

[0119] In an alternative manner, the terminal device further has a fourth RLC entity;

[0120] The receiving unit 503 is configured to receive the RLC PDUs corresponding to the at least one SN sent by the third RLC entity of the network device through the fourth RLC entity of the terminal device;

[0121] The sending unit 502 is further configured to send the RLC PDUs corresponding to the at least one SN to the first RLC entity of the terminal device through the fourth RLC entity of the terminal device, and the fourth RLC entity belongs to a PTP RLC entity;

[0122] The apparatus further includes: an adjustment unit (not shown in the figure), configured to adjust the reception window based on the received RLC PDUs corresponding to the at least one SN through the first RLC entity of the terminal device.

[0123] In an alternative manner, the receiving unit 503 is further configured to receive first configuration information sent by the network device, where the first configuration information is used to determine the protocol stack configuration for multicast reception and / or the protocol stack configuration for unicast reception;

[0124] Wherein, the protocol stack configuration for multicast reception is used to determine that the mode of the first RLC entity of the terminal device is the AM mode; the protocol stack configuration for unicast reception is used to determine that the mode of the fourth RLC entity of the terminal device is the AM mode.

[0125] In an alternative manner, the terminal device has a first RLC entity and a fourth RLC entity;

[0126] The generating unit 501 is configured to generate an RLC status report for receiving multicast service data through the first RLC entity of the terminal device;

[0127] The sending unit 502 is configured to send the RLC status report to the fourth RLC entity of the terminal device through the first RLC entity of the terminal device; and send the RLC status report to the third RLC entity of the network device through the fourth RLC entity of the terminal device;

[0128] Wherein, the first RLC entity belongs to a PTM RLC entity, and the third RLC entity and the fourth RLC entity belong to PTP RLC entities.

[0129] In an alternative manner, the third RLC entity of the network device sends first indication information or the RLC status report to the second RLC entity of the network device, wherein the first indication information is used to indicate the SN corresponding to the NACK feedback information and / or the SN corresponding to the ACK information, and the first indication information is determined based on the RLC status report;

[0130] The first indication information or the RLC status report is used for the second RLC entity of the network device to send RLC PDUs corresponding to at least one SN to the third RLC entity of the network device, and the at least one SN is the SN corresponding to the NACK feedback information indicated by the first indication information or the RLC status report;

[0131] Wherein, the second RLC entity belongs to a PTM RLC entity.

[0132] In an alternative manner, the receiving unit 503 is further configured to receive the RLC PDUs corresponding to the at least one SN sent by the third RLC entity of the network device through the fourth RLC entity of the terminal device, and send the RLC PDUs corresponding to the at least one SN to the first RLC entity of the terminal device;

[0133] The apparatus further includes: an adjustment unit, configured to adjust the receive window based on the received RLC PDUs corresponding to the at least one SN through the first RLC entity of the terminal device.

[0134] In an alternative manner, the receiving unit 503 is further configured to receive first configuration information sent by the network device, where the first configuration information is used to determine the protocol stack configuration for multicast reception and / or the protocol stack configuration for unicast reception;

[0135] Among them, the protocol stack configuration for multicast reception is used to determine that the mode of the first RLC entity of the terminal device is the AM mode or the UM mode; the protocol stack configuration for unicast reception is used to determine that the mode of the fourth RLC entity of the terminal device is the AM mode.

[0136] In an optional manner, the first configuration information includes second indication information, and the second indication information is used to indicate that the bearer corresponding to the first RLC entity is only used for downlink data reception.

[0137] In an optional manner, the terminal device has a first RLC entity;

[0138] The receiving unit 503 is further configured to receive multicast service data sent by the second RLC entity of the network device through the first RLC entity of the terminal device, where the scheduling information of the multicast service data is scrambled by a G-RNTI, and the first RLC entity and the second RLC entity belong to PTM RLC entities.

[0139] Those skilled in the art should understand that the relevant descriptions of the above multicast service retransmission device in the embodiments of the present application can be understood with reference to the relevant descriptions of the multicast service retransmission method in the embodiments of the present application.

[0140] Figure 6 is a schematic structural composition of the multicast service retransmission device provided by the embodiments of the present application Figure 2 , applied to a network device, such as Figure 6 shown, the multicast service retransmission device includes:

[0141] A receiving unit 601, configured to receive an RLC status report sent by a terminal device, where the RLC status report is an RLC status report generated by the terminal device for multicast service data reception, and the RLC status report is used for the network device to determine the RLC PDUs that need to be retransmitted;

[0142] A sending unit 602, configured to retransmit RLC PDUs to the terminal device in a unicast manner.

[0143] In an optional manner, the RLC status report is an RLC status report generated by the first RLC entity of the terminal device for multicast service data reception;

[0144] The receiving unit 601 is configured to receive the RLC status report sent by the first RLC entity of the terminal device through the second RLC entity of the network device;

[0145] Among them, the first RLC entity and the second RLC entity belong to PTM RLC entities.

[0146] In an alternative manner, the RLC status report is used for a second RLC entity of the network device to send RLC PDUs corresponding to at least one SN to a third RLC entity of the network device, where the at least one SN is the SN corresponding to the NACK feedback information indicated by the RLC status report, and the third RLC entity belongs to a PTP RLC entity.

[0147] In an alternative manner, the sending unit 602 is configured to send, through a third RLC entity of the network device, the RLC PDUs corresponding to the at least one SN to a fourth RLC entity of the terminal device, where the RLC PDUs corresponding to the at least one SN are sent by the fourth RLC entity of the terminal device to a first RLC entity of the terminal device, and the fourth RLC entity belongs to a PTP RLC entity.

[0148] In an alternative manner, the sending unit 602 is further configured to send first configuration information to the terminal device, where the first configuration information is used to determine the protocol stack configuration for multicast reception and / or the protocol stack configuration for unicast reception;

[0149] Wherein, the protocol stack configuration for multicast reception is used to determine that the mode of the first RLC entity of the terminal device is the AM mode; the protocol stack configuration for unicast reception is used to determine that the mode of the fourth RLC entity of the terminal device is the AM mode.

[0150] In an alternative manner, the RLC status report is an RLC status report generated by a first RLC entity of the terminal device for multicast service data reception, and the RLC status report is sent by the first RLC entity of the terminal device to a fourth RLC entity of the terminal device;

[0151] The receiving unit 601 is configured to receive, through a third RLC entity of the network device, the RLC status report sent by the fourth RLC entity of the terminal device;

[0152] Wherein, the first RLC entity belongs to a PTM RLC entity, and the third RLC entity and the fourth RLC entity belong to a PTP RLC entity.

[0153] In an alternative manner, the sending unit 602 is further configured to send first indication information or the RLC status report to a second RLC entity of the network device through a third RLC entity of the network device, where the first indication information is used to indicate the SN corresponding to the NACK feedback information and / or the SN corresponding to the ACK information, and the first indication information is determined based on the RLC status report;

[0154] The first indication information or the RLC status report is used for a second RLC entity of the network device to send RLC PDUs corresponding to at least one SN to a third RLC entity of the network device, where the at least one SN is the SN corresponding to the NACK feedback information indicated by the first indication information or the RLC status report;

[0155] Wherein, the second RLC entity belongs to a PTM RLC entity.

[0156] In an optional manner, the sending unit 602 is configured to send the RLC PDUs corresponding to the at least one SN to a fourth RLC entity of the terminal device through a third RLC entity of the network device, and the RLC PDUs corresponding to the at least one SN are sent by the fourth RLC entity of the terminal device to a first RLC entity of the terminal device.

[0157] In an optional manner, the sending unit 602 is further configured to send first configuration information to the terminal device, where the first configuration information is used to determine a protocol stack configuration for multicast reception and / or a protocol stack configuration for unicast reception;

[0158] Wherein, the protocol stack configuration for multicast reception is used to determine that the mode of the first RLC entity of the terminal device is the AM mode or the UM mode; the protocol stack configuration for unicast reception is used to determine that the mode of the fourth RLC entity of the terminal device is the AM mode.

[0159] In an optional manner, the first configuration information includes second indication information, where the second indication information is used to indicate that the bearer corresponding to the first RLC entity is only used for downlink data reception.

[0160] In an optional manner, the sending unit 602 is further configured to send multicast service data to a first RLC entity of the terminal device through a second RLC entity of the network device, where scheduling information of the multicast service data is scrambled by a G-RNTI, and the first RLC entity and the second RLC entity belong to PTM RLC entities.

[0161] Those skilled in the art should understand that the relevant descriptions of the above retransmission device for multicast services in the embodiments of the present application can be understood with reference to the relevant descriptions of the retransmission method for multicast services in the embodiments of the present application.

[0162] Figure 7 It is a schematic structural diagram of a communication device 700 provided by an embodiment of the present application. The communication device may be a terminal device or a network device. Figure 7The communication device 700 shown includes a processor 710, and the processor 710 can call and run a computer program from a memory to implement the methods in the embodiments of the present application.

[0163] Optionally, as Figure 7 shown, the communication device 700 may further include a memory 720. Among them, the processor 710 can call and run a computer program from the memory 720 to implement the methods in the embodiments of the present application.

[0164] Among them, the memory 720 can be a separate device independent of the processor 710, or can be integrated in the processor 710.

[0165] Optionally, as Figure 7 shown, the communication device 700 may further include a transceiver 730, and the processor 710 can control the transceiver 730 to communicate with other devices. Specifically, it can send information or data to other devices, or receive information or data sent by other devices.

[0166] Among them, the transceiver 730 can include a transmitter and a receiver. The transceiver 730 may further include an antenna, and the number of antennas can be one or more.

[0167] Optionally, the communication device 700 may specifically be the network device in the embodiments of the present application, and the communication device 700 can implement the corresponding processes implemented by the network device in the various methods of the embodiments of the present application. For the sake of brevity, it will not be elaborated here.

[0168] Optionally, the communication device 700 may specifically be the mobile terminal / terminal device in the embodiments of the present application, and the communication device 700 can implement the corresponding processes implemented by the mobile terminal / terminal device in the various methods of the embodiments of the present application. For the sake of brevity, it will not be elaborated here.

[0169] Figure 8 is a schematic structural diagram of the chip in the embodiments of the present application. Figure 8 The chip 800 shown includes a processor 810, and the processor 810 can call and run a computer program from a memory to implement the methods in the embodiments of the present application.

[0170] Optionally, as Figure 8 shown, the chip 800 may further include a memory 820. Among them, the processor 810 can call and run a computer program from the memory 820 to implement the methods in the embodiments of the present application.

[0171] Among them, the memory 820 can be a separate device independent of the processor 810, or can be integrated in the processor 810.

[0172] Optionally, the chip 800 may further include an input interface 830. Among them, the processor 810 may control the input interface 830 to communicate with other devices or chips. Specifically, it may obtain information or data sent by other devices or chips.

[0173] Optionally, the chip 800 may further include an output interface 840. Among them, the processor 810 may control the output interface 840 to communicate with other devices or chips. Specifically, it may output information or data to other devices or chips.

[0174] Optionally, the chip may be applied to the network device in the embodiments of the present application, and the chip may implement the corresponding processes implemented by the network device in the various methods of the embodiments of the present application. For the sake of brevity, details are not described herein again.

[0175] Optionally, the chip may be applied to the mobile terminal / terminal device in the embodiments of the present application, and the chip may implement the corresponding processes implemented by the mobile terminal / terminal device in the various methods of the embodiments of the present application. For the sake of brevity, details are not described herein again.

[0176] It should be understood that the chip mentioned in the embodiments of the present application may also be referred to as a system-on-chip, system chip, chip system, or system-on-chip.

[0177] Figure 9 is a schematic block diagram of a communication system 900 provided by an embodiment of the present application. As Figure 9 shown, the communication system 900 includes a terminal device 910 and a network device 920.

[0178] Among them, the terminal device 910 may be used to implement the corresponding functions implemented by the terminal device in the above method, and the network device 920 may be used to implement the corresponding functions implemented by the network device in the above method. For the sake of brevity, details are not described herein again.

[0179] It should be understood that the processor in the embodiments of the present application may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method embodiments can be completed by the integrated logic circuit in the hardware of the processor or instructions in software form. The above-mentioned processor may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. It can implement or execute various methods, steps and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as being executed and completed by the hardware decoding processor, or executed and completed by a combination of the hardware and software modules in the decoding processor. The software module may be located in a mature storage medium in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. This storage medium is located in the memory, and the processor reads the information in the memory and combines its hardware to complete the steps of the above method.

[0180] It can be understood that the memory in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchlink dynamic random access memory (SLDRAM), and direct rambus random access memory (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include but not be limited to these and any other suitable types of memory.

[0181] It should be understood that the above-mentioned memory is by way of example but not limitation. For example, the memory in the embodiments of the present application can also be a static random access memory (SRAM), a dynamic random access memory (DRAM), a synchronous dynamic random access memory (SDRAM), a double data rate synchronous dynamic random access memory (DDR SDRAM), an enhanced synchronous dynamic random access memory (ESDRAM), a synch link dynamic random access memory (SLDRAM), and a direct rambus random access memory (DR RAM), etc. That is to say, the memory in the embodiments of the present application is intended to include but not be limited to these and any other suitable types of memory.

[0182] The embodiments of the present application further provide a computer-readable storage medium for storing a computer program.

[0183] Optionally, the computer-readable storage medium can be applied to the network device in the embodiments of the present application, and the computer program causes the computer to execute the corresponding processes implemented by the network device in the various methods of the embodiments of the present application. For the sake of brevity, details are not described herein again.

[0184] Optionally, the computer-readable storage medium can be applied to the mobile terminal / terminal device in the embodiments of the present application, and the computer program causes the computer to execute the corresponding processes implemented by the mobile terminal / terminal device in the various methods of the embodiments of the present application. For the sake of brevity, details are not described herein again.

[0185] The embodiments of the present application further provide a computer program product, including computer program instructions.

[0186] Optionally, the computer program product can be applied to the network device in the embodiments of the present application, and the computer program instructions cause the computer to execute the corresponding processes implemented by the network device in the various methods of the embodiments of the present application. For the sake of brevity, details are not described herein again.

[0187] Optionally, the computer program product can be applied to the mobile terminal / terminal device in the embodiments of the present application, and the computer program instructions cause the computer to execute the corresponding processes implemented by the mobile terminal / terminal device in the various methods of the embodiments of the present application. For the sake of brevity, details are not described herein again.

[0188] The embodiments of the present application further provide a computer program.

[0189] Optionally, the computer program can be applied to the network device in the embodiments of the present application. When the computer program runs on the computer, it causes the computer to execute the corresponding processes implemented by the network device in the various methods of the embodiments of the present application. For the sake of brevity, details are not described herein again.

[0190] Optionally, the computer program can be applied to the mobile terminal / terminal device in the embodiments of the present application. When the computer program runs on the computer, it causes the computer to execute the corresponding processes implemented by the mobile terminal / terminal device in the various methods of the embodiments of the present application. For the sake of brevity, details are not described herein again.

[0191] Those of ordinary skill in the art will realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented in electronic hardware, or in a combination of computer software and electronic hardware. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. A professional technician can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0192] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein.

[0193] In several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of devices or units can be in electrical, mechanical, or other forms.

[0194] If the described functions are implemented in the form of software function 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 application, in essence, or the part that contributes to the prior art, or this part 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 for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program codes.

[0195] The above is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in this application, and all should be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A retransmission method for multicast services, the method comprises: A terminal device generates a radio link control (RLC) status report for receiving multicast service data, and sends the RLC status report to a network device, where the RLC status report is used by the network device to determine radio link control protocol data units (RLC PDUs) that need to be retransmitted; The terminal device receives the RLC PDUs retransmitted by the network device in a unicast manner; The terminal device generates an RLC status report for receiving multicast service data, and sends the RLC status report to the network device, including: A first RLC entity of the terminal device generates an RLC status report for receiving multicast service data, and sends the RLC status report to a second RLC entity of the network device; Wherein, the first RLC entity and the second RLC entity belong to point-to-multipoint (PTM) RLC entities; the terminal device reports the RLC status report to the network device in a unicast manner, and scheduling information corresponding to the RLC status report is scrambled by a C-RNTI.

2. The method according to claim 1, wherein, The RLC status report is used by a second RLC entity of the network device to send RLC PDUs corresponding to at least one sequence number (SN) to a third RLC entity of the network device, where the at least one SN is an SN corresponding to NACK feedback information indicated by the RLC status report, and the third RLC entity belongs to a point-to-point (PTP) RLC entity.

3. The method according to claim 2, wherein, The terminal device receives the RLC PDUs retransmitted by the network device in a unicast manner, including: A fourth RLC entity of the terminal device receives the RLC PDUs corresponding to the at least one SN sent by the third RLC entity of the network device, and sends the RLC PDUs corresponding to the at least one SN to the first RLC entity of the terminal device, where the fourth RLC entity belongs to a PTP RLC entity; The method further comprises: the first RLC entity of the terminal device adjusts a reception window based on the received RLC PDUs corresponding to the at least one SN.

4. The method according to any one of claims 1 to 3, wherein, The method further comprises: The terminal device receives first configuration information sent by the network device, where the first configuration information is used to determine a protocol stack configuration for multicast reception and / or a protocol stack configuration for unicast reception; Wherein, the protocol stack configuration for multicast reception is used to determine that a mode of the first RLC entity of the terminal device is an AM mode; the protocol stack configuration for unicast reception is used to determine that a mode of the fourth RLC entity of the terminal device is an AM mode.

5. The method according to claim 4, wherein, The first configuration information includes second indication information, where the second indication information is used to indicate that a bearer corresponding to the first RLC entity is only used for downlink data reception.

6. The method according to any one of claims 1 to 3, 5, wherein, Before the terminal device generates an RLC status report for multicast service data reception, the method further includes: A first RLC entity of the terminal device receives multicast service data sent by a second RLC entity of the network device, where scheduling information of the multicast service data is scrambled by a G-RNTI, and the first RLC entity and the second RLC entity belong to PTM RLC entities.

7. A retransmission method for a multicast service, the method includes: The network device receives an RLC status report sent by the terminal device, where the RLC status report is an RLC status report generated by the terminal device for multicast service data reception, and the RLC status report is used for the network device to determine RLC PDUs that need to be retransmitted; The network device retransmits RLC PDUs to the terminal device in a unicast manner; The RLC status report is an RLC status report generated by a first RLC entity of the terminal device for multicast service data reception; The network device receiving the RLC status report sent by the terminal device includes: A second RLC entity of the network device receives the RLC status report sent by the first RLC entity of the terminal device; wherein the first RLC entity and the second RLC entity belong to PTM RLC entities; the terminal device reports the RLC status report to the network device in a unicast manner, and scheduling information corresponding to the RLC status report is scrambled by a C-RNTI.

8. The method according to claim 7, wherein, The RLC status report is used for a second RLC entity of the network device to send RLC PDUs corresponding to at least one SN to a third RLC entity of the network device, where the at least one SN is an SN corresponding to NACK feedback information indicated by the RLC status report, and the third RLC entity belongs to a PTP RLC entity.

9. The method according to claim 8, wherein, The network device retransmitting the RLC PDU to the terminal device in a unicast manner includes: A third RLC entity of the network device sends the RLC PDUs corresponding to the at least one SN to a fourth RLC entity of the terminal device, and the RLC PDUs corresponding to the at least one SN are sent by the fourth RLC entity of the terminal device to the first RLC entity of the terminal device, and the fourth RLC entity belongs to a PTP RLC entity.

10. The method according to any one of claims 7 to 9, wherein, The method further includes: The network device sends first configuration information to the terminal device, and the first configuration information is used to determine a protocol stack configuration for multicast reception and / or a protocol stack configuration for unicast reception; wherein the protocol stack configuration for multicast reception is used to determine that the mode of the first RLC entity of the terminal device is the AM mode; the protocol stack configuration for unicast reception is used to determine that the mode of the fourth RLC entity of the terminal device is the AM mode.

11. The method according to claim 10, wherein, The first configuration information includes second indication information, and the second indication information is used to indicate that the bearer corresponding to the first RLC entity is only for downlink data reception.

12. The method according to any one of claims 7 to 9 and 11, wherein, before the network device receives the RLC status report sent by the terminal device, the method further includes: a second RLC entity of the network device sends multicast service data to a first RLC entity of the terminal device, wherein scheduling information of the multicast service data is scrambled by a G-RNTI, and the first RLC entity and the second RLC entity belong to PTM RLC entities.

13. A retransmission device for multicast services, applied to a terminal device, the device comprises: a generating unit, configured to generate an RLC status report for receiving multicast service data; a sending unit, configured to send the RLC status report to a network device, and the RLC status report is used for the network device to determine RLC PDUs that need to be retransmitted; a receiving unit, configured to receive RLC PDUs retransmitted by the network device in a unicast manner; the terminal device has a first RLC entity; the generating unit is configured to generate an RLC status report for receiving multicast service data through the first RLC entity of the terminal device; the sending unit is configured to send the RLC status report to a second RLC entity of the network device through the first RLC entity of the terminal device; wherein, the first RLC entity and the second RLC entity belong to PTM RLC entities; the terminal device reports the RLC status report to the network device in a unicast manner, and scheduling information corresponding to the RLC status report is scrambled by a C-RNTI.

14. The device according to claim 13, wherein, the RLC status report is used for a second RLC entity of the network device to send RLC PDUs corresponding to at least one SN to a third RLC entity of the network device, the at least one SN is an SN corresponding to NACK feedback information indicated by the RLC status report, and the third RLC entity belongs to a PTP RLC entity.

15. The device according to claim 14, wherein, the terminal device further has a fourth RLC entity; the receiving unit is configured to receive, through the fourth RLC entity of the terminal device, the RLC PDUs corresponding to the at least one SN sent by the third RLC entity of the network device; the sending unit is further configured to send, through the fourth RLC entity of the terminal device, the RLC PDUs corresponding to the at least one SN to the first RLC entity of the terminal device, and the fourth RLC entity belongs to a PTP RLC entity; the device further includes: an adjustment unit, configured to adjust a reception window based on the received RLC PDUs corresponding to the at least one SN through the first RLC entity of the terminal device.

16. The device according to any one of claims 13 to 15, wherein, The receiving unit is further configured to receive first configuration information sent by the network device, where the first configuration information is used to determine the protocol stack configuration for multicast reception and / or the protocol stack configuration for unicast reception; Among them, the protocol stack configuration for multicast reception is used to determine that the mode of the first RLC entity of the terminal device is the AM mode; the protocol stack configuration for unicast reception is used to determine that the mode of the fourth RLC entity of the terminal device is the AM mode.

17. The apparatus according to claim 16, Among them, The first configuration information includes second indication information, where the second indication information is used to indicate that the bearer corresponding to the first RLC entity is only used for downlink data reception.

18. The apparatus according to any one of claims 13 to 15 and 17, Among them, The terminal device has a first RLC entity; The receiving unit is further configured to receive multicast service data sent by the second RLC entity of the network device through the first RLC entity of the terminal device, where the scheduling information of the multicast service data is scrambled by a G-RNTI, and the first RLC entity and the second RLC entity belong to PTM RLC entities.

19. A retransmission apparatus for multicast services, applied to a network device, the apparatus comprises: a receiving unit, configured to receive an RLC status report sent by a terminal device, where the RLC status report is an RLC status report generated by the terminal device for multicast service data reception, and the RLC status report is used for the network device to determine the RLC PDUs that need to be retransmitted; a sending unit, configured to retransmit RLC PDUs to the terminal device in a unicast manner; The RLC status report is an RLC status report generated by the first RLC entity of the terminal device for multicast service data reception; The receiving unit is configured to receive the RLC status report sent by the first RLC entity of the terminal device through the second RLC entity of the network device; Among them, the first RLC entity and the second RLC entity belong to PTM RLC entities; the terminal device reports the RLC status report to the network device in a unicast manner, and the scheduling information corresponding to the RLC status report is scrambled by a C-RNTI.

20. The apparatus according to claim 19, Among them, The RLC status report is used for the second RLC entity of the network device to send RLC PDUs corresponding to at least one SN to the third RLC entity of the network device, where the at least one SN is the SN corresponding to the NACK feedback information indicated by the RLC status report, and the third RLC entity belongs to a PTP RLC entity.

21. The apparatus according to claim 20, Among them, The sending unit is configured to send the RLC PDUs corresponding to the at least one SN to the fourth RLC entity of the terminal device through the third RLC entity of the network device. The RLC PDUs corresponding to the at least one SN are sent by the fourth RLC entity of the terminal device to the first RLC entity of the terminal device, and the fourth RLC entity belongs to the PTP RLC entity.

22. The apparatus according to any one of claims 19 to 21, wherein, the sending unit is further configured to send first configuration information to the terminal device, and the first configuration information is used to determine the protocol stack configuration for multicast reception and / or the protocol stack configuration for unicast reception; wherein, the protocol stack configuration for multicast reception is used to determine that the mode of the first RLC entity of the terminal device is the AM mode; and the protocol stack configuration for unicast reception is used to determine that the mode of the fourth RLC entity of the terminal device is the AM mode.

23. The apparatus according to claim 22, wherein, the first configuration information includes second indication information, and the second indication information is used to indicate that the bearer corresponding to the first RLC entity is only used for downlink data reception.

24. The apparatus according to any one of claims 19 to 21 and 23, wherein, the sending unit is further configured to send multicast service data to the first RLC entity of the terminal device through the second RLC entity of the network device, wherein the scheduling information of the multicast service data is scrambled by a G-RNTI, and the first RLC entity and the second RLC entity belong to the PTM RLC entity.

25. A terminal device, comprising: a processor and a memory, the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the method according to any one of claims 1 to 6.

26. A network device, comprising: a processor and a memory, the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the method according to any one of claims 7 to 12.

27. A chip, comprising: a processor, configured to call and run a computer program from a memory, so that a device installed with the chip executes the method according to any one of claims 1 to 6.

28. A chip, comprising: a processor, configured to call and run a computer program from a memory, so that a device installed with the chip executes the method according to any one of claims 7 to 12.

29. A computer-readable storage medium, configured to store a computer program, and the computer program causes a computer to execute the method according to any one of claims 1 to 6.

30. A computer-readable storage medium, configured to store a computer program, and the computer program causes a computer to execute the method according to any one of claims 7 to 12.

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