Multicast transmission feedback processing method, device, base station and terminal

Abstract

The present application provides a multicast transmission feedback processing method, device, base station, and terminal. The method is applied to the base station and includes: the base station receives a first RLC status report sent by the terminal, wherein the first RLC status report is generated by the terminal based on data received via point-to-multipoint PTM transmission; if the status of the first RLC PDU in the first RLC status report is a negative response NACK, and it is determined to retransmit the first RLC PDU to the terminal via unicast, then based on the first status report, a second RLC status report is generated; wherein the status of the first RLC PDU in the second RLC status report is an acknowledgement response ACK; based on the second RLC status report, the RLC sending window of the PTM transmission is moved; and based on the first RLC status report, the first RLC PDU is retransmitted to the terminal via unicast. The embodiments of the present application can realize the reasonable movement of the RLC sending window under PTM, and ensure the smooth transmission of broadcast and multicast services to a group of terminals over the air interface.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a multicast transmission feedback processing method, device, base station, and terminal. Background Art

[0002] Starting with Release 17, 5G supports Multicast and Broadcast Services (MBS). The service bearer that carries MBS service data over the air interface is called an MRB (MBS Radio Bearer). MBS service data can be transmitted over the air interface using either point-to-multipoint (PTM) or point-to-point (PTP) transmission. PTM transmission means that data sent by a base station over the air interface is received simultaneously by a group of terminals, while PTP transmission means that data sent by a base station over the air interface is received by only one terminal.

[0003] In PTM Radio Link Control Acknowledged Mode (RLCAM), the RLC entity relationship and transmission direction between the base station and the terminal are as follows: Figure 1 As shown in Figure 1, the AM RLC entity of the base station gNB sends an RLC PDU to the AM RLC entities of a group of terminals (UE1, UE2, ..., UEn). Each terminal then sends an RLC status report to the base station to provide feedback on whether the RLC PDU was correctly received. RLC AM, as an acknowledgement mode, has the following two basic characteristics:

[0004] 1. The RLC sending window is driven by the lower boundary. All RLC protocol data units (PDUs) with RLC sequence numbers (SN) less than the lower boundary RLCSN must have been correctly received.

[0005] For PTM transmission, if one of the terminals in a group reports that a certain RLC PDU was not correctly received (e.g., RLC SN = K, not correctly received), the RLC SN at the lower boundary of the base station's RLC transmit window cannot be greater than K. This may cause the base station's RLC window to stagnate, preventing the transmission of new data packets.

[0006] 2. RLC AM requires that all RLC PDUs are received correctly. If the number of transmissions of an RLC PDU exceeds the maximum number of RLC transmissions, the radio link fails.

[0007] For PTM, if a terminal fails to successfully receive an RLC PDU, the RLC PDU will be retransmitted continuously, resulting in a waste of air interface resources and causing other terminals to repeatedly receive the RLC PDU, resulting in terminal power consumption. Summary of the Invention

[0008] The purpose of the present application is to provide a multicast transmission feedback processing method, device, base station and terminal to solve the problem in the prior art that, during PTM transmission, the existing RLC status report feedback and RLC retransmission mechanism in the RLC AM mode may cause the sending window of the sending end to be unable to move and data cannot be sent in time; and because some terminals fail to successfully receive the RLC PDU and repeatedly retransmit it, resulting in waste of air interface resources and power consumption caused by repeated reception by other terminals.

[0009] In order to solve the above technical problems, an embodiment of the present application provides a multicast transmission feedback processing method, which is applied to a base station. The method includes:

[0010] The base station receives a first RLC status report sent by the terminal, wherein the first RLC status report is generated by the terminal according to data received through point-to-multipoint PTM transmission;

[0011] If the status of the first RLC PDU in the first RLC status report is a negative acknowledgement (NACK), and it is determined that the first RLC PDU is to be retransmitted to the terminal in a unicast manner, generating a second RLC status report according to the first status report; wherein the status of the first RLC PDU in the second RLC status report is an acknowledgement (ACK);

[0012] According to the second RLC status report, the RLC sending window of the PTM transmission is moved; and according to the first RLC status report, the first RLC PDU is retransmitted to the terminal via unicast.

[0013] Optionally, the above method further includes:

[0014] When it is determined, based on the first RLC status report and the second RLC status report, that the lower boundary of the RLC sending window of the base station is greater than the lower boundary of the RLC receiving window of the terminal, the offset value of the RLC receiving window of the terminal is indicated to the terminal; wherein the offset value is used by the terminal to adjust the RLC receiving window.

[0015] Optionally, indicating to the terminal an offset value of the RLC receive window of the terminal includes any one of the following:

[0016] Including the offset value in an RLC control PDU and indicating it to the terminal;

[0017] Including the offset value in a Media Access Control Control Element (MAC CE) and indicating it to the terminal;

[0018] The offset value is included in downlink control information (DCI) and indicated to the terminal.

[0019] Optionally, the offset value is the difference between the lower boundary of the RLC sending window of the base station and the lower boundary of the RLC receiving window of the terminal.

[0020] Optionally, the method further includes:

[0021] Configuring an offset value of the RLC receiving window for the terminal by at least one of the following methods:

[0022] Notifying the terminal receiving the broadcast multicast service MBS of the offset value by broadcasting;

[0023] Notifying the terminal receiving the broadcast multicast service MBS of the offset value through multicast signaling;

[0024] Notifying the terminal of the offset value through unicast signaling;

[0025] The offset value is specified by the protocol.

[0026] Optionally, the determining to retransmit the first RLC PDU to the terminal in a unicast manner includes at least one of the following:

[0027] When the base station sends data to N terminals using the PTM transmission mode and receives NACKs sent by M terminals, it determines to retransmit the first RLC PDU to the terminal via unicast; wherein the terminal is one of the M terminals, M is less than a preset value, and M and N are both positive integers.

[0028] Optionally, the above method further includes:

[0029] When the number of retransmissions of the first RLC PDU exceeds a threshold, perform one of the following operations:

[0030] Deactivating a cell that sends the MBS service;

[0031] Initiating a cell handover for the terminal;

[0032] Instruct the terminal to enter an idle state.

[0033] The present application also provides a multicast transmission feedback processing method, which is applied to a terminal and includes:

[0034] Sending a first RLC status report to a base station; wherein the first RLC status report is generated based on data transmitted by the base station using PTM;

[0035] A first RLC PDU retransmitted by the base station in a unicast manner is received, wherein the first RLC PDU is an RLC PDU whose status in the first RLC status report is a negative response NACK.

[0036] Optionally, the above method further includes:

[0037] The RLC receiving window of the terminal is adjusted according to the offset value.

[0038] Optionally, the offset value is obtained by:

[0039] Receive an offset value of the RLC receiving window of the terminal indicated by the base station; wherein the offset value is sent by the base station when it is determined that the lower boundary of the RLC sending window of the base station is greater than the lower boundary of the RLC receiving window of the terminal.

[0040] Optionally, the receiving the offset value of the RLC receiving window of the terminal indicated by the base station includes any one of the following:

[0041] receiving the offset value indicated by the base station through an RLC control PDU;

[0042] receiving the offset value indicated by the base station through a MAC CE;

[0043] Receive the offset value indicated by the base station through downlink control information DCI.

[0044] Optionally, the offset value is the difference between the lower boundary of the RLC sending window of the base station and the lower boundary of the RLC receiving window of the terminal.

[0045] Optionally, the above method further includes:

[0046] Obtaining an offset value of the RLC receiving window of the terminal by at least one of the following methods:

[0047] receiving the offset value notified by the base station in a broadcast manner;

[0048] receiving the offset value notified by the base station through multicast signaling;

[0049] receiving the offset value notified by the base station through unicast signaling;

[0050] The offset value is specified by the protocol.

[0051] An embodiment of the present application provides a base station, comprising: a transceiver, a memory, and a processor;

[0052] A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations:

[0053] The base station receives a first RLC status report sent by the terminal, wherein the first RLC status report is generated by the terminal according to data received through point-to-multipoint PTM transmission;

[0054] If the status of the first RLC PDU in the first RLC status report is a negative acknowledgement (NACK), and it is determined that the first RLC PDU is to be retransmitted to the terminal in a unicast manner, generating a second RLC status report according to the first status report; wherein the status of the first RLC PDU in the second RLC status report is an acknowledgement (ACK);

[0055] According to the second RLC status report, the RLC sending window of the PTM transmission is moved; and according to the first RLC status report, the first RLC PDU is retransmitted to the terminal via unicast.

[0056] Optionally, the processor is further configured to read the computer program in the memory and perform the following operations:

[0057] When it is determined, based on the first RLC status report and the second RLC status report, that the lower boundary of the RLC sending window of the base station is greater than the lower boundary of the RLC receiving window of the terminal, the offset value of the RLC receiving window of the terminal is indicated to the terminal; wherein the offset value is used by the terminal to adjust the RLC receiving window.

[0058] Optionally, the processor is further configured to read the computer program in the memory and perform any one of the following operations:

[0059] Including the offset value in an RLC control PDU and indicating it to the terminal;

[0060] Including the offset value in a media access control element MAC CE and indicating it to the terminal;

[0061] The offset value is included in downlink control information DCI and indicated to the terminal.

[0062] Optionally, the offset value is the difference between the lower boundary of the RLC sending window of the base station and the lower boundary of the RLC receiving window of the terminal.

[0063] Optionally, the processor is further configured to read the computer program in the memory and perform the following operations:

[0064] Configuring an offset value of the RLC receiving window for the terminal by at least one of the following methods:

[0065] Notifying the terminal receiving the broadcast multicast service MBS of the offset value by broadcasting;

[0066] Notifying the terminal receiving the broadcast multicast service MBS of the offset value through multicast signaling;

[0067] Notifying the terminal of the offset value through unicast signaling;

[0068] The offset value is specified by the protocol.

[0069] Optionally, the processor is further configured to read the computer program in the memory and perform the following operations:

[0070] When the base station sends data to N terminals using the PTM transmission mode and receives NACKs sent by M terminals, it determines to retransmit the first RLC PDU to the terminal via unicast; wherein the terminal is one of the M terminals, M is less than a preset value, and M and N are both positive integers.

[0071] Optionally, the processor is further configured to read the computer program in the memory and perform the following operations:

[0072] When the number of retransmissions of the first RLC PDU exceeds a threshold, perform one of the following operations:

[0073] Deactivating a cell that sends the MBS service;

[0074] Initiating a cell handover for the terminal;

[0075] Instruct the terminal to enter an idle state.

[0076] An embodiment of the present application provides a terminal, including: a memory, a transceiver, and a processor;

[0077] A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations:

[0078] Sending a first RLC status report to a base station; wherein the first RLC status report is generated based on data transmitted by the base station using PTM;

[0079] A first RLC PDU retransmitted by the base station in a unicast manner is received, wherein the first RLC PDU is an RLC PDU whose status in the first RLC status report is a negative response NACK.

[0080] Optionally, the processor is further configured to read the computer program in the memory and perform the following operations:

[0081] The RLC receiving window of the terminal is adjusted according to the offset value.

[0082] Optionally, the processor is further configured to read the computer program in the memory and perform the following operations:

[0083] Receive an offset value of the RLC receiving window of the terminal indicated by the base station; wherein the offset value is sent by the base station when it is determined that the lower boundary of the RLC sending window of the base station is greater than the lower boundary of the RLC receiving window of the terminal.

[0084] Optionally, the processor is further configured to read the computer program in the memory and perform the following operations:

[0085] receiving the offset value indicated by the base station through an RLC control PDU;

[0086] receiving the offset value indicated by the base station through a MAC CE;

[0087] Receive the offset value indicated by the base station through downlink control information DCI.

[0088] Optionally, the offset value is the difference between the lower boundary of the RLC sending window of the base station and the lower boundary of the RLC receiving window of the terminal.

[0089] Optionally, the processor is further configured to read the computer program in the memory and perform the following operations:

[0090] Obtaining an offset value of the RLC receiving window of the terminal by at least one of the following methods:

[0091] receiving the offset value notified by the base station in a broadcast manner;

[0092] receiving the offset value notified by the base station through multicast signaling;

[0093] receiving the offset value notified by the base station through unicast signaling;

[0094] The offset value is specified by the protocol.

[0095] An embodiment of the present application provides a multicast transmission feedback processing device, which is applied to a base station. The device includes:

[0096] A first receiving module, configured to receive, by the base station, a first RLC status report sent by a terminal, wherein the first RLC status report is generated by the terminal according to data received via point-to-multipoint PTM transmission;

[0097] a first processing module, configured to generate a second RLC status report according to the first status report if the status of the first RLC PDU in the first RLC status report is a negative acknowledgement (NACK) and it is determined that the first RLC PDU is to be retransmitted to the terminal in a unicast manner; wherein the status of the first RLC PDU in the second RLC status report is an acknowledgement (ACK);

[0098] a second processing module, configured to move the RLC sending window of the PTM transmission according to the second RLC status report; and

[0099] A first sending module is configured to retransmit the first RLC PDU to the terminal via unicast according to the first RLC status report.

[0100] An embodiment of the present application provides a multicast transmission feedback processing device, applied to a terminal, the device including:

[0101] A second sending module is configured to send a first RLC status report to a base station; wherein the first RLC status report is generated based on data transmitted by the base station using PTM;

[0102] The second receiving module is configured to receive a first RLC PDU retransmitted by the base station in a unicast manner, wherein the first RLC PDU is an RLC PDU whose status is a negative response NACK in the first RLC status report.

[0103] An embodiment of the present application provides a processor-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the multicast transmission feedback processing method described above are implemented.

[0104] An embodiment of the present application provides a chip product having a computer program stored thereon. When the computer program is executed by the chip product, the steps of the multicast transmission feedback processing method described above are implemented.

[0105] The beneficial effects of the above technical solution of this application are as follows:

[0106] In the above scheme, when the base station uses the point-to-multipoint PTM transmission mode to send data to the terminal, and the PTM transmission mode is the radio link control confirmation mode RLC AM, the base station receives the first RLC status report sent by the terminal; if the status of the first RLC PDU in the first RLC status report is a negative response NACK, and it is determined to retransmit the first RLC PDU to the terminal via unicast, then a second RLC status report is generated according to the first status report; wherein the status of the first RLC PDU in the second RLC status report is a confirmation response ACK; further, by moving the RLC sending window of the PTM transmission according to the second RLC status report, it can be ensured that the RLC sending window can be reasonably moved; and, according to the first RLC status report, the first RLC PDU is retransmitted to the terminal via unicast, which can avoid the problem of repeated retransmission due to the failure of some terminals to successfully receive the RLC PDU, resulting in waste of air interface resources and power consumption caused by repeated reception by other terminals. BRIEF DESCRIPTION OF THE DRAWINGS

[0107] Figure 1 Schematic diagram of the RLC entity relationship and transmission direction between the base station and the terminal under RLC AM configuration;

[0108] Figure 2 This is a flow chart of a multicast transmission feedback processing method according to an embodiment of the present application;

[0109] Figure 3 This is the second flow chart of the multicast transmission feedback processing method according to an embodiment of the present application;

[0110] Figure 4 This is one of the structural block diagrams of the multicast transmission feedback processing device according to an embodiment of the present application;

[0111] Figure 5 This is the second structural block diagram of the multicast transmission feedback processing device according to an embodiment of the present application;

[0112] Figure 6 This is a structural diagram of a base station according to an embodiment of the present application;

[0113] Figure 7 This is a structural diagram of a terminal according to an embodiment of the present application. DETAILED DESCRIPTION

[0114] To make the technical problems, technical solutions, and advantages to be solved by the present invention more apparent, a detailed description will be given below with reference to the accompanying drawings and specific embodiments. In the following description, specific details such as specific configurations and components are provided solely to facilitate a comprehensive understanding of the embodiments of the present invention. Therefore, it should be clear to those skilled in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present invention. In addition, descriptions of known functions and configurations have been omitted for clarity and brevity.

[0115] It should be understood that references throughout this specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic associated with the embodiment is included in at least one embodiment of the present invention. Therefore, the appearances of "in one embodiment" or "in an embodiment" throughout this specification do not necessarily refer to the same embodiment. Furthermore, these particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0116] In various embodiments of the present invention, it should be understood that the size of the serial numbers of the following processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0117] In embodiments of the present invention, the term "and / or" describes the association relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0118] In the embodiments of the present application, the term "plurality" refers to two or more than two, and other quantifiers are similar.

[0119] During PTM transmission, if the RLC AM mode is configured, according to the existing RLC status report feedback and RLC retransmission mechanism in the RLC AM mode, on the one hand, the sending window of the sending end may not be moved, and data cannot be sent in a timely manner; on the other hand, the RLC PDU is repeatedly retransmitted because some terminals fail to receive it successfully, which will cause air interface resources to be wasted and power consumption caused by repeated reception by other terminals.

[0120] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0121] Specifically, the embodiments of the present application provide a multicast transmission feedback processing method, device, base station and terminal to solve the problem in the prior art that during PTM transmission, the RLC status report feedback and RLC retransmission mechanism in the existing RLC AM mode may cause the sending window of the sending end to be unable to move and data cannot be sent in time; and some terminals fail to successfully receive the RLC PDU and repeatedly retransmit it, resulting in waste of air interface resources and power consumption caused by repeated reception by other terminals.

[0122] like Figure 2 As shown, an embodiment of the present application provides a multicast transmission feedback processing method, which is applied to a base station. The base station uses a point-to-multipoint PTM transmission mode to send data to a terminal, and the PTM transmission mode is a radio link control acknowledgement mode RLC AM. The method includes the following steps:

[0123] Step 101: The base station receives a first RLC status report sent by a terminal; wherein the first RLC status report is generated by the terminal according to data received via point-to-multipoint PTM transmission;

[0124] In this step, the terminal is one of the multiple terminals corresponding to the base station in the PTM transmission. The terminal sends a first RLC status report according to the existing RLC status reporting mechanism. Specifically, the terminal side uniformly feeds back a first RLC status report for the RLC PDU from a PTM RLC entity, regardless of whether it is received through unicast (C-RNTI scrambling) or multicast (G-RNTI scrambling).

[0125] Step 102: If the status of the first RLC PDU in the first RLC status report is a negative acknowledgement (NACK), and it is determined that the first RLC PDU is to be retransmitted to the terminal via unicast, generating a second RLC status report based on the first status report; wherein the status of the first RLC PDU in the second RLC status report is an acknowledgement (ACK);

[0126] In this step, the first RLC PDU may be one or more RLC PDUs and / or one or more RLC PDU segments. The step of determining to retransmit the first RLC PDU to the terminal in a unicast manner includes:

[0127] The base station sends data to N terminals using a PTM transmission mode and, when receiving NACKs sent by M terminals, determines to retransmit a first RLC PDU to the terminal using a unicast mode; wherein the terminal is one of the M terminals, M is less than a preset value, and both M and N are positive integers, and M<preset value<N;

[0128] The determining to retransmit the first RLC PDU to the terminal in a unicast manner may further include:

[0129] In a case where the terminal is determined to be a target terminal, it is determined to retransmit the first RLC PDU to the terminal in a unicast manner.

[0130] Example 1: When the base station receives NACK feedback from only one or a few terminals, it determines to send retransmissions to these terminals using PTP instead of using PTM.

[0131] Example 2: The base station uses PTP to send retransmissions for a specific terminal, such as a terminal that is far away from the center. When receiving NACK feedback from the terminal, the base station uses PTP to send RLC PDU retransmissions.

[0132] The above examples 1 and 2 are merely illustrative and not limiting.

[0133] Step 103: moving the RLC sending window of the PTM transmission according to the second RLC status report; and retransmitting the first RLC PDU to the terminal via unicast according to the first RLC status report.

[0134] In this step, the first RLC status report is used to perform retransmissions for the terminal, i.e., retransmit RLC PDUs and / or RLC PDU segments set as NACK in the first RLC status report. The second RLC status report is used as a basis for moving the RLC transmit window. Specifically, the RLC transmit window for the PTM transmission is moved based on the second RLC status report. Specifically, the lower boundary of the RLC transmit window is set to the SN of the last successfully received (i.e., with the largest RLC SN value) RLC PDU (i.e., RLC feedback is ACK).

[0135] In the above embodiment, when the base station sends data to the terminal using a point-to-multipoint PTM transmission mode, and the PTM transmission mode is in the radio link control acknowledgement mode RLC AM, after the base station receives the first RLC status report sent by the terminal, if the status of the first RLC PDU in the first RLC status report is a negative response NACK, and it is determined to retransmit the first RLC PDU to the terminal via unicast, then a second RLC status report is generated based on the first status report; wherein the status of the first RLC PDU in the second RLC status report is an acknowledgement response ACK; further, by moving the RLC sending window of the PTM transmission according to the second RLC status report, it can be ensured that the RLC sending window can be reasonably moved; further, by retransmitting the first RLC PDU to the terminal via unicast according to the first RLC status report, it can be avoided that some terminals fail to successfully receive the first RLC PDU and repeatedly retransmit it in the PTM transmission mode, resulting in waste of air interface resources and power consumption caused by repeated reception by other terminals.

[0136] Furthermore, based on the above embodiment, it is necessary to maintain the RLC receiving window of the terminal to avoid the problem that the terminal PTM RLC receiving window lags behind and may receive multicast transmission RLC PDUs outside the window due to the inconsistency between the starting points of the base station PTM RLC sending window and the terminal PTM RLC receiving window.

[0137] Specifically, the terminal's RLC receive window maintenance method includes the following two situations:

[0138] Case 1

[0139] In one embodiment, when the base station determines, based on the first RLC status report and the second RLC status report, that the lower boundary of the RLC sending window of the base station is greater than the lower boundary of the RLC receiving window of the terminal, the base station indicates the offset value of the RLC receiving window of the terminal to the terminal; wherein the offset value is used by the terminal to adjust the RLC receiving window.

[0140] In this case, the offset value is temporarily determined by the base station and notified to the terminal. If the base station determines that the lower boundary SN1 of the RLC transmit window formed by the first RLC status report (the RLC PDU with the minimum SN value that has not yet been successfully received) is greater than the lower boundary SN2 of the RLC receive window formed by the second RLC status report, the base station sets the offset value and indicates it to the terminal.

[0141] Specifically, in this case, the offset value is the difference between the lower boundary of the base station's RLC transmit window and the lower boundary of the terminal's RLC receive window. That is, the offset value RX_off = SN2 - SN1, which is the difference between the SNs of the last correctly received RLC PDU determined in the first RLC status report and the second RLC status report. It is the exact offset value between the starting point of the base station's PTM RLC transmit window and the starting point of the terminal's PTM RLC receive window.

[0142] In particular, if the lower boundary of the RLC sending window is reversed, that is, when the SN value reaches 2^(SN length), the SN value starts counting from 0, RX_off=SN2+2^(SN length)-SN1.

[0143] Furthermore, indicating to the terminal an offset value of the RLC receive window of the terminal includes any one of the following:

[0144] Method 1: Include the difference in the RLC control PDU and indicate it to the terminal;

[0145] In this manner, the RLC control PDU includes at least one field for carrying the offset value RX_off.

[0146] Mode 2: The difference is included in a media access control element (MAC CE) and indicated to the terminal, wherein the MAC CE also includes an RLC ID or a logical channel ID (LC ID) corresponding to the RLC entity of the terminal;

[0147] In this manner, when MAC CE is used, the MAC CE includes at least two fields, one of which is used to carry the RLCID or LC ID, and the other is used to carry the offset value RX_off.

[0148] Method 3: Include the difference in downlink control information DCI and indicate it to the terminal; wherein, the DCI is carried by a physical downlink control channel PDCCH, and the PDCCH is scrambled with a group radio network temporary identity (Group Radio Network Temporary Identity, G-RNTI for short) corresponding to the RLC entity of the terminal.

[0149] In this method, the DCI includes at least one field for carrying the offset value RX_off.

[0150] In a specific embodiment, the step of using the difference as the offset value and notifying the terminal includes any one of the following methods:

[0151] Method 1: The difference is included in an RLC control PDU and sent to the terminal;

[0152] In this manner, the RLC control PDU includes at least one field for carrying the offset value RX_off.

[0153] Mode 2: The difference is included in a media access control element (MAC CE) and sent to the terminal, wherein the MAC CE also includes an RLC ID or a logical channel ID (LC ID) corresponding to an RLC entity of the terminal;

[0154] In this manner, when MAC CE is used, the MAC CE includes at least two fields, one of which is used to carry the RLCID or LC ID, and the other is used to carry the offset value RX_off.

[0155] Method 3: Include the difference in downlink control information DCI and send it to the terminal; wherein, the DCI is carried by a physical downlink control channel (PDCCH), and the PDCCH is scrambled with a group radio network temporary identifier G-RNTI corresponding to the RLC entity of the terminal.

[0156] In this method, the DCI includes at least one field for carrying the offset value RX_off.

[0157] Case 2

[0158] Configuring an offset value of the RLC receiving window for the terminal by at least one of the following methods:

[0159] Mode 1: Notifying the terminal receiving the broadcast multicast service MBS of the offset value via broadcast;

[0160] In this manner, the base station notifies all terminals receiving MBS services through broadcasting, that is, for all RLC entities corresponding to the MBS services, the terminals use the same offset value RX_off.

[0161] Mode 2: Notifying the terminal receiving the broadcast multicast service MBS of the offset value through multicast signaling;

[0162] In this manner, the base station configures the terminal through multicast signaling. Then, for a PTM RLC entity of an MRB, the RLC receiving windows of a group of terminals receiving the MRB use the same offset value RX_off.

[0163] Mode 3: Notifying the terminal of the offset value through unicast signaling;

[0164] In this manner, the base station notifies the terminal through unicast signaling. For a PTM RLC entity of an MRB, the terminal adopts the offset value RX_off notified by the unicast signaling.

[0165] Method 4: stipulate the offset value through an agreement;

[0166] In this method, it is stipulated through an agreement that all terminals, all RLC entities corresponding to all MBS services, and terminals all adopt the same offset value RX_off;

[0167] It should be noted that the offset values in the above Methods 1 to 4 are estimated values.

[0168] It should be noted that in the prior art, the RLC reception window of the terminal is RX_Next <= SN < RX_Next + AM_Window_Size. If an RLC SN outside this range is received, it is considered that the RLC PDU corresponding to this RLC SN has left the window and is not processed. Among them, RX_Next is the lower boundary of the RLC reception window, defined as the next RLC SN corresponding to the last correctly received in-sequence RLCPDU; the window size AM_Window_Size = 2018 (12-bit SN) or 131072 (18-bit SN).

[0169] In this embodiment, by indicating the offset value of the RLC reception window to the terminal or configuring the offset value of the RLC reception window for the terminal, the RLC reception window on the terminal side is extended from RX_Next <= SN < RX_Next + AM_Window_Size to RX_Next <= SN < RX_Next + AM_Window_Size + RX_off; where RX_off is the offset value of the RLC reception window. In this way, it is possible to avoid the problem that the terminal may receive out-of-window multicast transmission RLC PDUs due to the inconsistent starting points of the base station PTM RLC transmission window and the terminal PTM RLC reception window.

[0170] In an embodiment, the above method further includes: when the retransmission count of the first RLC PDU exceeds a threshold, perform one of the following operations:

[0171] Deactivate the cell transmitting the MBS service;

[0172] Initiate a cell handover for the terminal;

[0173] Indicate the terminal to enter the idle state.

[0174] In this embodiment, when the number of retransmissions of the first RLC PDU exceeds a threshold, it is considered that a wireless link failure occurs between the base station and the terminal, and the cell sending the MBS service is deactivated, thereby triggering the terminal to receive MBS transmission on other activated cells or triggering the terminal to reestablish the wireless link to access other available cells; by initiating a cell handover for the terminal, the terminal can access an available cell to ensure accurate reception of the service; by instructing the terminal to enter an idle state, the terminal can receive MBS services in the idle state or access other available cells as needed.

[0175] like Figure 3 As shown, an embodiment of the present application provides a multicast transmission feedback processing method, which is applied to a terminal. Specifically, the method includes the following steps:

[0176] Step 201: Send a first RLC status report to a base station; wherein the first RLC status report is generated based on data transmitted by the base station using PTM;

[0177] The PTM transmission mode is Radio Link Control Acknowledgement Mode RLC AM;

[0178] In this step, the terminal sends a first RLC status report according to the existing RLC status reporting mechanism. Specifically, the terminal side uniformly feeds back a first RLC status report for the RLC PDU from a PTM RLC entity, regardless of whether it is received via unicast (C-RNTI scrambling) or multicast (G-RNTI scrambling).

[0179] Step 202: Receive a first RLC PDU retransmitted by the base station in a unicast manner, wherein the first RLC PDU is an RLC PDU whose status in the first RLC status report is a negative response NACK.

[0180] In this step, the status of the first RLC PDU in the first RLC status report is a negative response NACK; and the first RLC PDU may be one or more RLC PDUs and / or one or more RLC PDU segments.

[0181] In the above embodiments, when the base station uses the point-to-multipoint (PTM) transmission mode to send data to the terminal, and the PTM transmission mode is in the radio link control acknowledged mode (RLC AM), after the base station receives the first RLC status report sent by the terminal, if it is determined according to the first RLC status report that the first RLC PDU is to be retransmitted to the terminal in unicast mode, and the status of the first RLC PDU in the first RLC status report is a negative acknowledgement (NACK), then the first RLC PDU is retransmitted to the terminal in unicast mode, which can avoid the problem of wasting air interface resources and power consumption caused by repeated retransmission in the PTM transmission mode due to some terminals not successfully receiving the first RLC PDU and repeated reception by other terminals.

[0182] Furthermore, based on the embodiments on the base station side, the RLC receive window on the terminal side needs to be maintained to avoid the problem that the RLC PDU of the multicast transmission outside the window may be received due to the inconsistency of the starting points of the base station PTM RLC transmit window and the terminal PTM RLC receive window (the terminal PTM RLC receive window lags behind).

[0183] In one embodiment, the above method further includes:

[0184] Adjust the RLC receive window of the terminal according to the offset value.

[0185] In this embodiment, on the terminal side, according to the offset value, the RLC receive window is extended and adjusted from: RX_Next <= SN < RX_Next + AM_Window_Size to: RX_Next <= SN < RX_Next + AM_Window_Size + RX_off; where RX_off is the offset value of the RLC receive window. In this way, the problem that the RLC PDU of the multicast transmission outside the window may be received by the terminal due to the inconsistency of the starting points of the base station PTM RLC transmit window and the terminal PTM RLC receive window can be avoided.

[0186] Specifically, the methods for the terminal to obtain the RLC receive window include the following two cases:

[0187] Case 1

[0188] Receive the offset value of the RLC receive window of the terminal indicated by the base station; where the offset value is sent by the base station when it determines that the lower boundary of the RLC transmit window of the base station is greater than the lower boundary of the RLC receive window of the terminal.

[0189] In this case, the offset value is temporarily determined by the base station and notified to the terminal. If the base station determines, based on the first RLC status report and the second RLC status report, that the lower boundary SN1 of the RLC sending window formed by the first RLC status report (the RLC PDU with the minimum SN value that has not been successfully received) is greater than the lower boundary SN2 of the RLC receiving window formed by the second RLC status report, the offset value is set and indicated to the terminal.

[0190] Specifically, in this case, the offset value is the difference between the lower boundary of the base station's RLC transmit window and the lower boundary of the terminal's RLC receive window. That is, the offset value RX_off = SN2 - SN1, which is the difference between the SNs of the last correctly received RLC PDU determined in the first RLC status report and the second RLC status report. It is the exact offset value between the starting point of the base station's PTM RLC transmit window and the starting point of the terminal's PTM RLC receive window.

[0191] In particular, if the lower boundary of the RLC sending window is reversed, that is, when the SN value reaches 2^(SN length), the SN value starts counting from 0, RX_off=SN2+2^(SN length)-SN1.

[0192] In one embodiment, the receiving of the offset value of the RLC receiving window of the terminal indicated by the base station includes any one of the following:

[0193] Mode 1: receiving the offset value indicated by the base station through an RLC control PDU;

[0194] In this manner, the RLC control PDU includes at least one field for carrying the offset value RX_off.

[0195] Mode 2: Receiving the offset value indicated by the base station through a MAC CE, wherein the MAC CE further includes an RLC ID or LC ID corresponding to the RLC entity of the terminal;

[0196] In this manner, when MAC CE is used, the MAC CE includes at least two fields, one of which is used to carry the RLCID or LC ID, and the other is used to carry the offset value RX_off.

[0197] Mode 3: Receive the offset value indicated by the base station through downlink control information DCI; wherein, the DCI is carried in a physical downlink control channel PDCCH, and the PDCCH is scrambled with a group radio network temporary identifier G-RNTI corresponding to the RLC entity of the terminal.

[0198] In this method, the DCI includes at least one field for carrying the offset value RX_off.

[0199] Case 2

[0200] In one embodiment, the terminal may further obtain the offset value of the RLC receiving window of the terminal through at least one of the following methods:

[0201] Method 1: receiving the offset value notified by the base station via broadcast;

[0202] In this manner, the base station notifies all terminals receiving MBS services through broadcasting, that is, for all RLC entities corresponding to the MBS services, the terminals use the same offset value RX_off.

[0203] Mode 2: receiving the offset value notified by the base station through multicast signaling;

[0204] In this manner, the base station configures the terminal through multicast signaling. Then, for a PTM RLC entity of an MRB, the RLC receiving windows of a group of terminals receiving the MRB use the same offset value RX_off.

[0205] Mode 3: receiving the offset value notified by the base station through unicast signaling;

[0206] In this manner, the base station notifies the terminal through unicast signaling. For a PTM RLC entity of an MRB, the terminal adopts the offset value RX_off notified by the unicast signaling.

[0207] Method 4: The offset value is specified through a protocol;

[0208] In this method, the protocol stipulates that all terminals, RLC entities corresponding to all MBS services, and terminals use the same offset value RX_off;

[0209] It should be noted that the offset values in the above manners 1 to 4 are estimated values. Among them, when the terminal receives the data transmission of the logical channel corresponding to the PTM RLC entity on the base station side, during the data reception process, the terminal adjusts the RLC reception window according to the offset value configured in the above manner as: RX_Next <= SN < RX_Next + AM_Window_Size + RX_off. It should be noted that in the prior art, the RLC reception window of the terminal is RX_Next <= SN < RX_Next + AM_Window_Size. If an RLC SN outside this range is received, it is considered that the RLC PDU corresponding to the RLC SN has left the window and is not processed. Among them, RX_Next is the lower boundary of the RLC reception window, defined as the next RLC SN corresponding to the last RLC PDU received correctly in sequence; the window size AM_Window_Size = 2018 (12-bit SN) or 131072 (18-bit SN).

[0210] In this embodiment, by indicating the offset value of the RLC reception window to the terminal or configuring the offset value of the RLC reception window for the terminal, the RLC reception window on the terminal side is extended from: RX_Next <= SN < RX_Next + AM_Window_Size to: RX_Next <= SN < RX_Next + AM_Window_Size + RX_off; where RX_off is the offset value of the RLC reception window. In this way, it is possible to avoid the problem that the terminal may receive multicast transmission RLC PDUs outside the window due to the inconsistent starting points of the base station PTM RLC transmission window and the terminal PTM RLC reception window.

[0211] Next, a multicast transmission feedback processing method of the present application will be introduced for specific application examples.

[0212] Example 1: For the scenario where RX_off is configured for the terminal by the Radio Resource Control (RRC) signaling of the base station.

[0213] 1. The terminal side may include the following steps:

[0214] Step 1: Receive the RLC window offset indication sent by the base station side and determine the RLC reception window offset value (RX_off).

[0215] The receiving window offset indication can be configured by the base station to all terminals receiving MBS services through broadcast; or sent by the base station to a group of terminals through multicast transmission, and this group of terminals receives the same MBS service or MBS session or MRB, that is, the configuration is configured per MBS service or per MBS session or per MRB; or configured by the base station to each terminal through unicast transmission.

[0216] Step 2: Receive data transmission of the logical channel corresponding to the PTM RLC entity. The data transmission is transmitted via multicast (scrambled with G-RNTI) or unicast (scrambled with Cell Radio Network Temporary Identity (C-RNTI)).

[0217] During data reception, the RLC receiving window is RX_Next <= SN <RX_Next+AM_Window_Size+RX_off。

[0218] Step 3: When the RLC status report is triggered, a first RLC status report is generated according to whether the RLC PDU and the RLC PDU segments are received correctly, and the first RLC status report is sent to the base station through the uplink channel of the PTM RLC AM.

[0219] Step 4: Receive the retransmission of the RLC PDU or RLC PDU segment sent by the base station side. The retransmission of the RLC PDU or RLC PDU segment can be transmitted to all terminals in the group via multicast (G-RNTI scrambling) or transmitted to the terminal via unicast (C-RNTI scrambling).

[0220] 2. The base station side correspondence may include the following steps:

[0221] Step 1: Configure the receive window offset value (RX_off) for the terminal.

[0222] Specifically, the configuration can be broadcast to all terminals receiving MBS services; or sent to a group of terminals through multicast transmission. These terminals receive the same MBS service, MBS session, or MRB, that is, the configuration is configured per MBS service, per MBS session, or per MRB; or configured to each terminal through unicast transmission.

[0223] Step 2: Send data to a group of terminals in a multicast manner, that is, send RLC PDUs of the PTM RLC entity in a multicast manner, where PDUs refers to multiple PDUs.

[0224] Step 3: Receive the first RLC status report sent by the terminal. For the first RLC PDU determined to be retransmitted via unicast, set it as RLC ACK, and generate a second RLC status report; wherein the status of the first RLC PDU in the first RLC status report is a negative acknowledgement NACK; use the second RLC status report as the basis for moving the RLC transmission window; use the first RLC status report sent by the terminal as the basis for RLC retransmission for the terminal, that is, retransmit the RLC PDU and / or RLC PDU segments set as NACK in the first RLC status report.

[0225] Step 4: Determine the retransmission of the RLC PDU or RLC PDU segment according to the first RLC status reports of all terminals that receive the MRB. This RLC retransmission can be transmitted to all terminals in the group via multicast (scrambling with G-RNTI) or transmitted to a single terminal via unicast (scrambling with C-RNTI).

[0226] Step 5: For a certain terminal, when the number of transmissions of an RLC PDU reaches the maximum RLC transmission number, it is considered that a radio link failure has occurred between the base station and this terminal. The cell where this MBS service occurs can be deactivated, or a handover can be initiated for this terminal, or this terminal can be instructed to return to the idle state.

[0227] Example 2: For the scenario where the offset value RX_off is specified by the protocol

[0228] I. The terminal side may include the following steps:

[0229] Step Ⅰ: Receive the data transmission of the logical channel corresponding to the PTM RLC entity. This data transmission is via multicast (scrambling with G-RNTI), or can also be via unicast (scrambling with C-RNTI). During the data reception process, the RLC reception window is RX_Next <= SN < RX_Next + AM_Window_Size + RX_off. This RX_off is specified in the protocol.

[0230] Step Ⅱ: When triggering the RLC status report, generate the first RLC status report according to the correct reception situation of the RLC PDU and RLC PDU segments, and send the first RLC status report to the base station through the uplink channel of the PTM RLC AM.

[0231] Step Ⅲ: Receive the retransmission of the RLC PDU or RLC PDU segment sent by the base station side. This retransmission of the RLC PDU or RLC PDU segment can be transmitted to all terminals in the group via multicast (scrambling with G-RNTI) or transmitted to this terminal via unicast (scrambling with C-RNTI).

[0232] 2. The base station side correspondence may include the following steps:

[0233] Step 1: Send data to a group of terminals via multicast, that is, send RLC PDUs of the PTM RLC entity via multicast.

[0234] Step 2: Receive the first RLC status report sent by the terminal. For RLC PDUs determined to be retransmitted via unicast, set them to RLC ACK, generate a second RLC status report, and use the second RLC status report as the basis for moving the RLC send window. Use the first RLC status report sent by the terminal as the basis for RLC retransmission to the terminal, that is, retransmit the RLC PDUs and / or RLC PDU segments set to NACK in the first RLC status report.

[0235] Step 3: Based on the first RLC status report of all terminals receiving the MRB, determine to retransmit the RLC PDU or RLC PDU segment. The retransmission of the RLC PDU or RLC PDU segment can be transmitted to all terminals in the group via multicast (G-RNTI scrambling) or to a single terminal via unicast (C-RNTI scrambling).

[0236] Step 4: For a certain terminal, when the number of transmissions of an RLC PDU reaches the maximum number of RLC transmissions, the base station considers that a radio link failure has occurred with the terminal and can deactivate the cell where the MBS service occurs, or initiate a handover for the terminal, or instruct the terminal to return to the idle state.

[0237] Example 3: Scenario where RX_off is temporarily determined by the base station and notified to the terminal

[0238] 1. The terminal side may include the following steps:

[0239] Step 1: Receive data transmission from the logical channel corresponding to the PTM RLC entity. The data transmission is transmitted via multicast (scrambled with G-RNTI) or unicast (scrambled with C-RNTI). During the data reception process, the RLC receiving window is RX_Next <= SN <RX_Next+AM_Window_Size。

[0240] Step 2: When the RLC status report is triggered, a first RLC status report is generated according to whether the RLC PDU and the RLC PDU segments are received correctly, and the first RLC status report is sent to the base station through the uplink channel of the PTM RLC AM.

[0241] Step 3 (optional): Receive the receive window offset value RX_off sent by the base station side using RLC control PDU or MAC CE or DCI.

[0242] Step 4: Continue to receive RLC PDU or RLC retransmission sent by the base station side, and set the receiving window to RX_Next <= SN <RX_Next+AM_Window_Size+RX_off。

[0243] 2. The base station side correspondence may include the following steps:

[0244] Step 1: Send data to a group of terminals via multicast, that is, send RLC PDUs of the PTM RLC entity via multicast.

[0245] Step 2: Receive the first RLC status report sent by the terminal. For RLC PDUs determined to be retransmitted via unicast, set them to RLC ACK, generate a second RLC status report, and use the second RLC status report as the basis for moving the RLC send window. The RLC status report sent by the terminal is used as RLC status report 2, which serves as the basis for performing RLC retransmission on the terminal, that is, retransmitting the RLC PDUs and / or RLC PDU segments set to NACK in the first RLC status report.

[0246] Step 3: If the lower boundary SN (SN1) of the sending window formed according to the second RLC status report is greater than the RLC PDU (SN2) of the minimum SN value that has not been successfully received by the specific terminal determined according to the first RLC status report, set RX_off = SN1-SN2 and send it to the terminal through RLC control PDU or MAC CE or DCI.

[0247] In particular, if the lower boundary of the sending window is reversed, that is, when the SN value reaches 2^(SN length), the SN value starts counting from 0, RX_off = SN1 + 2^(SN length) - SN2.

[0248] Step 4: Based on the RLC status reports of all terminals receiving the MRB, determine to retransmit the RLC PDU or RLC PDU segment. The retransmission of the RLC PDU or RLC PDU segment can be transmitted to all terminals in the group via multicast (G-RNTI scrambling) or to a single terminal via unicast (C-RNTI scrambling).

[0249] Step 5: For a certain terminal, when the number of transmissions of an RLC PDU reaches the maximum number of RLC transmissions, the base station considers that a radio link failure has occurred with the terminal and can deactivate the cell where the MBS service occurs, or initiate a handover for the terminal, or instruct the terminal to return to the idle state.

[0250] The present invention can achieve reasonable movement of the sending window and ensure that the terminal correctly receives the RLC PDU under the PTM RLC AM configuration. Furthermore, based on the first RLC status report, the first RLC PDU is retransmitted to the terminal via unicast, thereby avoiding the problem of repeated retransmission via PTM transmission due to some terminals failing to successfully receive the first RLC PDU, resulting in waste of air interface resources and power consumption caused by repeated reception by other terminals.

[0251] like Figure 4 As shown, an embodiment of the present application further provides a multicast transmission feedback processing device, which is applied to a base station. The base station uses a point-to-multipoint PTM transmission mode to send data to a terminal, and the PTM transmission mode is a radio link control acknowledgement mode RLC AM. The device 300 includes:

[0252] A first receiving module 401 is configured to receive, by the base station, a first RLC status report sent by a terminal, wherein the first RLC status report is generated by the terminal according to data received via point-to-multipoint PTM transmission;

[0253] A first processing module 402 is configured to generate a second RLC status report according to the first status report if the status of the first RLC PDU in the first RLC status report is a negative acknowledgement (NACK) and it is determined that the first RLC PDU is to be retransmitted to the terminal in a unicast manner; wherein the status of the first RLC PDU in the second RLC status report is an acknowledgement (ACK);

[0254] A second processing module 403 is configured to move the RLC sending window of the PTM transmission according to the second RLC status report; and

[0255] The first sending module 404 is configured to retransmit the first RLC PDU to the terminal via unicast according to the first RLC status report.

[0256] Optionally, the apparatus 400 further includes:

[0257] an offset value indication module, configured to indicate an offset value of the RLC receive window of the terminal to the terminal when it is determined, based on the first RLC status report and the second RLC status report, that the lower boundary of the RLC send window of the base station is greater than the lower boundary of the RLC receive window of the terminal; wherein the offset value is used by the terminal to adjust the RLC receive window.

[0258] Optionally, the offset value indication module includes any one of the following:

[0259] A first indicating unit, configured to include the offset value in an RLC control PDU and indicate it to the terminal;

[0260] A second indicating unit, configured to include the offset value in a media access control control element (MAC CE) and indicate it to the terminal, wherein the MAC CE further includes an RLC ID or a logical channel ID (LC ID) corresponding to an RLC entity of the terminal;

[0261] The third indication unit is used to include the offset value in the downlink control information DCI and indicate it to the terminal; wherein, the DCI is carried by the physical downlink control channel PDCCH, and the PDCCH is scrambled with the group radio network temporary identifier G-RNTI corresponding to the RLC entity of the terminal.

[0262] Optionally, the offset value is the difference between the lower boundary of the RLC sending window of the base station and the lower boundary of the RLC receiving window of the terminal.

[0263] Optionally, the apparatus 400 further includes:

[0264] The first offset value configuration module is configured to configure an offset value of the RLC receive window for the terminal by at least one of the following methods:

[0265] Notifying the terminal receiving the broadcast multicast service MBS of the offset value by broadcasting;

[0266] Notifying the terminal receiving the broadcast multicast service MBS of the offset value through multicast signaling;

[0267] Notifying the terminal of the offset value through unicast signaling;

[0268] The offset value is specified by the protocol.

[0269] Optionally, when determining to retransmit the first RLC PDU to the terminal in a unicast manner, the first processing module 402 is specifically configured to perform at least one of the following:

[0270] When the base station sends data to N terminals using the PTM transmission mode and receives NACKs sent by M terminals, it determines to retransmit the first RLC PDU to the terminal via unicast; wherein the terminal is one of the M terminals, M is less than a preset value, and M and N are both positive integers.

[0271] Optionally, the apparatus 400 further includes:

[0272] The third processing module is configured to perform one of the following operations when the number of retransmissions of the first RLC PDU exceeds a threshold:

[0273] Deactivating a cell that sends the MBS service;

[0274] Initiating a cell handover for the terminal;

[0275] Instruct the terminal to enter an idle state.

[0276] It should be noted here that the above-mentioned device provided by the embodiment of the present invention can implement all the method steps implemented by the above-mentioned method embodiment applied to the base station, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as the method embodiment will not be described in detail here.

[0277] like Figure 5 As shown, the embodiment of the present application further provides a multicast transmission feedback processing device, which is applied to a terminal. The device 500 includes:

[0278] The second sending module 501 is configured to send a first RLC status report to a base station; wherein the first RLC status report is generated based on data transmitted by the base station using PTM;

[0279] The second receiving module 502 is configured to receive a first RLC PDU retransmitted by the base station in a unicast manner, wherein the first RLC PDU is an RLC PDU whose status in the first RLC status report is a negative response NACK.

[0280] Optionally, the apparatus 500 further includes:

[0281] The window adjustment module is used to adjust the RLC receiving window of the terminal according to the offset value.

[0282] Optionally, the apparatus 500 further includes:

[0283] A third receiving module is used to receive the offset value of the RLC receiving window of the terminal indicated by the base station; wherein the offset value is sent by the base station when it determines, based on the first RLC status report and the second RLC status report, that the lower boundary of the RLC sending window of the base station is greater than the lower boundary of the RLC receiving window of the terminal.

[0284] Optionally, the third receiving module includes any one of the following:

[0285] A first receiving unit, configured to receive the offset value indicated by the base station through an RLC control PDU;

[0286] A second receiving unit, configured to receive the offset value indicated by the base station through a MAC CE;

[0287] The third receiving unit is configured to receive the offset value indicated by the base station through downlink control information DCI.

[0288] Optionally, the offset value is the difference between the lower boundary of the RLC sending window of the base station and the lower boundary of the RLC receiving window of the terminal.

[0289] Optionally, the apparatus 500 further includes:

[0290] The second offset value configuration module is configured to obtain the offset value of the RLC receiving window of the terminal by at least one of the following methods:

[0291] receiving the offset value notified by the base station in a broadcast manner;

[0292] receiving the offset value notified by the base station through multicast signaling;

[0293] receiving the offset value notified by the base station through unicast signaling;

[0294] The offset value is specified by the protocol.

[0295] It should be noted here that the above-mentioned device provided by the embodiment of the present invention can implement all the method steps implemented by the above-mentioned method embodiment applied to the terminal, and can achieve the same technical effect. The parts and beneficial effects that are the same as the method embodiment in this embodiment will not be described in detail here.

[0296] It should be noted that the division of units in the embodiments of the present application is schematic and is merely a logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0297] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a processor-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) or a processor to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0298] like Figure 6 As shown, an embodiment of the present invention further provides a base station, including a memory 620, a transceiver 600, and a processor 610;

[0299] The memory 620 is used to store computer programs; the transceiver 600 is used to send and receive data under the control of the processor 610; the processor 610 is used to read the computer program in the memory 620 and perform the following operations:

[0300] receiving a first RLC status report sent by a terminal, wherein the first RLC status report is generated by the terminal according to data received through point-to-multipoint PTM transmission;

[0301] If the status of the first RLC PDU in the first RLC status report is a negative acknowledgement (NACK), and it is determined that the first RLC PDU is to be retransmitted to the terminal in a unicast manner, generating a second RLC status report according to the first status report; wherein the status of the first RLC PDU in the second RLC status report is an acknowledgement (ACK);

[0302] According to the second RLC status report, the RLC sending window of the PTM transmission is moved; and according to the first RLC status report, the first RLC PDU is retransmitted to the terminal via unicast.

[0303] Optionally, the processor 610 is further configured to read the computer program in the memory 620 and perform the following operations:

[0304] When it is determined, based on the first RLC status report and the second RLC status report, that the lower boundary of the RLC sending window of the base station is greater than the lower boundary of the RLC receiving window of the terminal, the offset value of the RLC receiving window of the terminal is indicated to the terminal; wherein the offset value is used by the terminal to adjust the RLC receiving window.

[0305] Optionally, when indicating the offset value of the RLC receiving window of the terminal to the terminal, the processor 610 is specifically configured to perform any one of the following:

[0306] Including the offset value in an RLC control PDU and indicating it to the terminal;

[0307] Including the offset value in a media access control control element (MAC CE) and indicating it to the terminal, wherein the MAC CE further includes an RLC ID or a logical channel ID (LC ID) corresponding to an RLC entity of the terminal;

[0308] The offset value is included in downlink control information DCI and indicated to the terminal; wherein the DCI is carried by a physical downlink control channel PDCCH, and the PDCCH is scrambled with a group radio network temporary identifier G-RNTI corresponding to an RLC entity of the terminal.

[0309] Optionally, the offset value is the difference between the lower boundary of the RLC sending window of the base station and the lower boundary of the RLC receiving window of the terminal.

[0310] Optionally, the processor 610 is further configured to read the computer program in the memory 620 and perform the following operations:

[0311] Configuring an offset value of the RLC receiving window for the terminal by at least one of the following methods:

[0312] Notifying the terminal receiving the broadcast multicast service MBS of the offset value by broadcasting;

[0313] Notifying the terminal receiving the broadcast multicast service MBS of the offset value through multicast signaling;

[0314] Notifying the terminal of the offset value through unicast signaling;

[0315] The offset value is specified by the protocol.

[0316] Optionally, the processor 610 is further configured to read the computer program in the memory and perform the following operations:

[0317] When the base station sends data to N terminals using the PTM transmission mode and receives NACKs sent by M terminals, it determines to retransmit the first RLC PDU to the terminal via unicast; wherein the terminal is one of the M terminals, M is less than a preset value, and M and N are both positive integers.

[0318] Optionally, the processor 610 is further configured to read the computer program in the memory 620 and perform the following operations:

[0319] When the number of retransmissions of the first RLC PDU exceeds a threshold, perform one of the following operations:

[0320] Deactivating a cell that sends the MBS service;

[0321] Initiating a cell handover for the terminal;

[0322] Instruct the terminal to enter an idle state.

[0323] Among them, Figure 6 In the embodiment of the present invention, the bus architecture can include any number of interconnected buses and bridges, specifically linking various circuits such as one or more processors represented by processor 610 and memory represented by memory 620. The bus architecture can also link 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 further described herein. The bus interface provides an interface. The transceiver 600 can be a plurality of components, namely, a transmitter and a receiver, providing a unit for communicating with various other devices over a transmission medium, such as a wireless channel, a wired channel, an optical cable, or the like.

[0324] The processor 610 is responsible for managing the bus architecture and general processing, and the memory 620 can store data used by the processor 510 when performing operations.

[0325] The processor 610 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or a complex programmable logic device (CPLD). The processor may also adopt a multi-core architecture.

[0326] It should be noted here that the above-mentioned base station provided in the embodiment of the present invention can implement all the method steps implemented in the above-mentioned method embodiment applied to the base station, and can achieve the same technical effect. The parts and beneficial effects that are the same as the method embodiment in this embodiment will not be described in detail here.

[0327] like Figure 7 As shown, an embodiment of the present invention further provides a terminal, including a memory 720, a transceiver 700, and a processor 710;

[0328] The memory 720 is used to store computer programs; the transceiver 700 is used to send and receive data under the control of the processor; the processor 710 is used to read the computer program in the memory and perform the following operations:

[0329] Sending a first RLC status report to a base station; wherein the first RLC status report is generated based on data transmitted by the base station using PTM;

[0330] A first RLC PDU retransmitted by the base station in a unicast manner is received, wherein the first RLC PDU is an RLC PDU whose status in the first RLC status report is a negative response NACK.

[0331] Optionally, the processor 710 is further configured to read the computer program in the memory and perform the following operations:

[0332] The RLC receiving window of the terminal is adjusted according to the offset value.

[0333] Optionally, the processor 710 is further configured to read the computer program in the memory and perform the following operations:

[0334] Receive an offset value of the RLC receiving window of the terminal indicated by the base station; wherein the offset value is sent by the base station when it is determined that the lower boundary of the RLC sending window of the base station is greater than the lower boundary of the RLC receiving window of the terminal.

[0335] Optionally, when receiving the offset value of the RLC receiving window of the terminal indicated by the base station, the processor 710 is specifically configured to perform any one of the following:

[0336] receiving the offset value indicated by the base station through an RLC control PDU;

[0337] receiving the offset value indicated by the base station through a MAC CE;

[0338] Receive the offset value indicated by the base station through downlink control information DCI.

[0339] Optionally, the offset value is the difference between the lower boundary of the RLC sending window of the base station and the lower boundary of the RLC receiving window of the terminal.

[0340] Optionally, the processor 710 is further configured to read the computer program in the memory and perform the following operations:

[0341] Obtaining an offset value of the RLC receiving window of the terminal by at least one of the following methods:

[0342] receiving the offset value notified by the base station in a broadcast manner;

[0343] receiving the offset value notified by the base station through multicast signaling;

[0344] receiving the offset value notified by the base station through unicast signaling;

[0345] The offset value is specified by the protocol.

[0346] Among them, Figure 7 In the embodiment, the bus architecture may include any number of interconnected buses and bridges, specifically linking together various circuits of one or more processors represented by processor 710 and memory represented by memory 720. The bus architecture may also link together various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are all well known in the art and, therefore, will not be described further herein. The bus interface provides an interface. The transceiver 700 may be a plurality of components, namely, a transmitter and a receiver, providing a unit for communicating with various other devices on a transmission medium, such as a wireless channel, a wired channel, an optical cable, and other transmission media. For different user devices, the user interface 630 may also be an interface capable of connecting external or internal devices as required, and the connected devices include but are not limited to a keypad, a display, a speaker, a microphone, a joystick, and the like.

[0347] The processor 710 is responsible for managing the bus architecture and general processing, and the memory 720 can store data used by the processor x10 when performing operations.

[0348] The processor 710 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or a complex programmable logic device (CPLD). The processor may also adopt a multi-core architecture.

[0349] It should be noted here that the above-mentioned terminal provided by the embodiment of the present invention can implement all the method steps implemented by the above-mentioned method embodiment applied to the terminal, and can achieve the same technical effect. The parts and beneficial effects that are the same as the method embodiment in this embodiment will not be described in detail here.

[0350] In addition, a specific embodiment of the present invention further provides a processor-readable storage medium having a computer program stored thereon, wherein the program, when executed by the processor, implements the steps of the multicast transmission feedback processing method as described above. And the same technical effect can be achieved, so to avoid repetition, it will not be described here. The readable storage medium can be any available medium or data storage device that can be accessed by the processor, including but not limited to magnetic storage (such as floppy disk, hard disk, magnetic tape, magneto-optical disk (MO), etc.), optical storage (such as CD, DVD, BD, HVD, etc.), and semiconductor storage (such as ROM, EPROM, EEPROM, non-volatile memory (NAND FLASH), solid-state drive (SSD)), etc.

[0351] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage and optical storage, etc.) that contain computer-usable program code.

[0352] The present application is described with reference to the flow chart and / or block diagram of the method, device (system), and computer program product according to the embodiment of the present application. It should be understood that each process and / or box in the flow chart and / or block diagram and the combination of the process and / or box in the flow chart and / or block diagram can be realized by computer-executable instructions. These computer-executable instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processing machine or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for realizing the function specified in a flow chart or multiple flows and / or a box or multiple boxes in the block diagram.

[0353] These processor-executable instructions may also be stored in a processor-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the processor-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0354] These processor-executable instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0355] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A multicast transmission feedback processing method, characterized in that: Applied to a base station, the method includes: The base station receives a first RLC status report sent by the terminal, wherein the first RLC status report is generated by the terminal according to data received through point-to-multipoint PTM transmission; If the status of the first RLC PDU in the first RLC status report is a negative acknowledgement (NACK), and it is determined that the first RLC PDU is to be retransmitted to the terminal in a unicast manner, generating a second RLC status report according to the first RLC status report; wherein the status of the first RLC PDU in the second RLC status report is an acknowledgement (ACK); According to the second RLC status report, the RLC sending window of the PTM transmission is moved; and according to the first RLC status report, the first RLC PDU is retransmitted to the terminal via unicast.

2. The multicast transmission feedback processing method according to claim 1, characterized in that: The method further comprises: When it is determined, based on the first RLC status report and the second RLC status report, that the lower boundary of the RLC sending window of the base station is greater than the lower boundary of the RLC receiving window of the terminal, the offset value of the RLC receiving window of the terminal is indicated to the terminal; wherein the offset value is used by the terminal to adjust the RLC receiving window.

3. The multicast transmission feedback processing method according to claim 2, wherein: The indicating to the terminal an offset value of the RLC receiving window of the terminal, includes any one of the following: Including the offset value in an RLC control PDU and indicating it to the terminal; Including the offset value in a media access control element MAC CE and indicating it to the terminal; The offset value is included in downlink control information DCI and indicated to the terminal.

4. The multicast transmission feedback processing method according to claim 3, characterized in that: The offset value is a difference between a lower boundary of an RLC sending window of the base station and a lower boundary of an RLC receiving window of the terminal.

5. The multicast transmission feedback processing method according to claim 1, characterized in that: The method further comprises: Configuring an offset value of the RLC receiving window for the terminal by at least one of the following methods: Notifying the terminal receiving the broadcast multicast service MBS of the offset value by broadcasting; Notifying the terminal receiving the broadcast multicast service MBS of the offset value through multicast signaling; Notifying the terminal of the offset value through unicast signaling; The offset value is specified by the protocol.

6. The multicast transmission feedback processing method according to claim 1, characterized in that: The determining to retransmit the first RLC PDU to the terminal in a unicast manner includes at least one of the following: When the base station sends data to N terminals using the PTM transmission mode and receives NACKs sent by M terminals, it determines to retransmit the first RLC PDU to the terminal via unicast; wherein the terminal is one of the M terminals, M is less than a preset value, and M and N are both positive integers.

7. The multicast transmission feedback processing method according to claim 1, characterized in that: The method further comprises: When the number of retransmissions of the first RLC PDU exceeds a threshold, perform one of the following operations: Deactivating a cell that sends the MBS service; Initiating a cell handover for the terminal; Instruct the terminal to enter an idle state.

8. A multicast transmission feedback processing method, characterized in that: Applied to a terminal, the method includes: Sending a first RLC status report to a base station; wherein the first RLC status report is generated based on data transmitted by the base station using PTM; receiving a first RLC PDU retransmitted by the base station in a unicast manner, wherein the first RLC PDU is an RLC PDU with a negative response (NACK) status in the first RLC status report; The method further comprises: Adjust the RLC receiving window of the terminal according to the offset value; wherein the offset value is the difference between the lower boundary of the RLC sending window formed by the first RLC status report and the lower boundary of the RLC receiving window formed by the second RLC status report, the second RLC status report is generated by the base station according to the first RLC status report, and the status of the first RLC PDU in the second RLC status report is an acknowledgment response ACK.

9. The multicast transmission feedback processing method according to claim 8, characterized in that: The offset value is obtained by: Receive an offset value of the RLC receiving window of the terminal indicated by the base station; wherein the offset value is sent by the base station when it is determined that the lower boundary of the RLC sending window of the base station is greater than the lower boundary of the RLC receiving window of the terminal.

10. The multicast transmission feedback processing method according to claim 9, characterized in that: The offset value of the RLC receiving window of the terminal indicated by the base station includes any one of the following: receiving the offset value indicated by the base station through an RLC control PDU; receiving the offset value indicated by the base station through a MAC CE; Receive the offset value indicated by the base station through downlink control information DCI.

11. The multicast transmission feedback processing method according to claim 8, characterized in that: The method further comprises: Obtaining an offset value of the RLC receiving window of the terminal by at least one of the following methods: receiving the offset value notified by the base station in a broadcast manner; receiving the offset value notified by the base station through multicast signaling; receiving the offset value notified by the base station through unicast signaling; The offset value is specified by the protocol.

12. A base station, characterized in that: The base station includes: a transceiver, a memory, and a processor; A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations: The base station receives a first RLC status report sent by the terminal, wherein the first RLC status report is generated by the terminal according to data received through point-to-multipoint PTM transmission; If the status of the first RLC PDU in the first RLC status report is a negative acknowledgement (NACK), and it is determined that the first RLC PDU is to be retransmitted to the terminal in a unicast manner, generating a second RLC status report according to the first RLC status report; wherein the status of the first RLC PDU in the second RLC status report is an acknowledgement (ACK); According to the second RLC status report, the RLC sending window of the PTM transmission is moved; and according to the first RLC status report, the first RLC PDU is retransmitted to the terminal via unicast.

13. A terminal, characterized in that: include: Memory, transceiver, processor; memory for storing computer programs; a transceiver, configured to transmit and receive data under the control of the processor; A processor is configured to read the computer program in the memory and perform the following operations: Sending a first RLC status report to a base station; wherein the first RLC status report is generated based on data transmitted by the base station using PTM; receiving a first RLC PDU retransmitted by the base station in a unicast manner, wherein the first RLC PDU is an RLC PDU with a negative response (NACK) status in the first RLC status report; The processor is further configured to read the computer program in the memory and perform the following operations: Adjust the RLC receiving window of the terminal according to the offset value; wherein the offset value is the difference between the lower boundary of the RLC sending window formed by the first RLC status report and the lower boundary of the RLC receiving window formed by the second RLC status report, the second RLC status report is generated by the base station according to the first RLC status report, and the status of the first RLC PDU in the second RLC status report is an acknowledgment response ACK. The terminal according to claim 13 , wherein: The processor is further configured to read the computer program in the memory and perform the following operations: Receive an offset value of the RLC receiving window of the terminal indicated by the base station; wherein the offset value is sent by the base station when it is determined that the lower boundary of the RLC sending window of the base station is greater than the lower boundary of the RLC receiving window of the terminal.

15. A multicast transmission feedback processing device, characterized in that: Applied to a base station, the device includes: A first receiving module, configured to receive, by the base station, a first RLC status report sent by a terminal, wherein the first RLC status report is generated by the terminal according to data received via point-to-multipoint PTM transmission; a first processing module, configured to generate a second RLC status report according to the first RLC status report if the status of the first RLC PDU in the first RLC status report is a negative acknowledgement (NACK) and it is determined that the first RLC PDU is to be retransmitted to the terminal in a unicast manner; wherein the status of the first RLC PDU in the second RLC status report is an acknowledgement (ACK); a second processing module, configured to move the RLC sending window of the PTM transmission according to the second RLC status report; and A first sending module is configured to retransmit the first RLC PDU to the terminal via unicast according to the first RLC status report.

16. A multicast transmission feedback processing device, characterized in that: Applied to a terminal, the device includes: A second sending module is configured to send a first RLC status report to a base station; wherein the first RLC status report is generated based on data transmitted by the base station using PTM; A second receiving module is configured to receive a first RLC PDU retransmitted by the base station in a unicast manner, wherein the first RLC PDU is an RLC PDU with a status of negative response NACK in the first RLC status report; A window adjustment module is used to adjust the RLC receiving window of the terminal according to an offset value; wherein the offset value is the difference between the lower boundary of the RLC sending window formed by the first RLC status report and the lower boundary of the RLC receiving window formed by the second RLC status report, the second RLC status report is generated by the base station according to the first RLC status report, and the status of the first RLC PDU in the second RLC status report is an acknowledgment response ACK.

17. A processor-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the computer program implements the steps of the multicast transmission feedback processing method according to any one of claims 1 to 7, or implements the steps of the multicast transmission feedback processing method according to any one of claims 8 to 11.

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