Enhanced RLC AM mode reliable transmission method and apparatus for base stations and repeaters

Abstract

This application discloses an enhanced RLC AM mode reliable transmission method and apparatus for base stations and repeaters, comprising: responding to a data transmission command, determining the number of sequence numbers (SNs) within a transmission window, wherein the SNs within the transmission window are the SNs of Service Data Units (SDNs) that have been transmitted but have not received acknowledgment; determining whether the number of SNs has reached a preset threshold, which is less than the window length; if the number of SNs has reached the preset threshold, actively transmitting the first PDU (Programmable Dedicated Unit) within the transmission window that has not received a positive acknowledgment (ACK) to the UE using an enhanced strategy, wherein the PDU includes multiple SDUs; and, if a reception failure is determined based on a status report fed back by the user terminal UE, restarting the base station or notifying higher layers to stop transmitting SDUs. This solves the problem that existing methods cannot delete data cached in memory when the transmission window is blocked, and because higher layers continuously send data to the cache, the base station eventually crashes due to memory exhaustion.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of base station data transmission, in particular to an enhanced RLC AM mode reliability transmission method and device for base stations and repeaters. BACKGROUND

[0002] In the AM (Acknowledged Mode) mode, the sending end needs to wait for the receiving end to reply the confirmation information whether the data is correctly received after sending the data. The sending end needs to resend the data indicated as receiving failure in the confirmation information after receiving the confirmation information. Therefore, the AM mode can provide reliable data transmission service for the upper layer, and is mainly suitable for the services which are not sensitive to time delay but sensitive to errors, such as FTP (File Transfer Protocol) service and the like.

[0003] The sending end maintains the SN of the data to be confirmed by using the sending window, and the corresponding SN is deleted from the sending window after receiving the ACK confirmation information. However, the sending window may be in a blocked state due to network congestion or failure to receive the ACK of the UE, so that the SN in the sending window gradually increases. From the minimum SN which has not received the positive confirmation, the sending end can send at most a set number of data, and the set number corresponds to the window length. This will cause that the data in the memory cache cannot be deleted when the sending window is blocked, and eventually the base station crashes due to the consumption of the memory because the upper layer continuously sends data to the cache. SUMMARY

[0004] The purpose of the present application is to provide an enhanced RLC AM mode reliability transmission method and device for base stations and repeaters, which solves the problem that the data in the memory cache cannot be deleted when the sending window is blocked, and eventually the base station / repeater crashes due to the consumption of the memory because the upper layer continuously sends data to the cache.

[0005] In a first aspect, an enhanced RLC AM mode reliability transmission method for base stations and repeaters is provided, and the method comprises: In response to a data sending instruction, the number of sequence numbers (SNs) in a sending window is determined, wherein the SNs in the sending window are the SNs of the service data units (SDUs) which have been sent and for which no confirmation has been received; It is determined whether the number of SNs reaches a preset threshold, wherein the preset threshold is less than the window length; If the number of SNs reaches the preset threshold, an enhanced strategy is used to actively send the first PDU for which no positive confirmation ACK has been received in the sending window to the UE, and the PDU comprises a plurality of SDUs; When it is determined that the receiving fails according to the status report fed back by the user terminal (UE), the base station / relay station is restarted or informed to stop sending SDU.

[0006] In some possible embodiments, when the number of SNs reaches a preset threshold, the method further comprises any one of the following steps: The SDU corresponding to the minimum SN in the sending window is not in the buffer, and a timeout timer is started; After the SDU corresponding to the minimum SN in the sending window is sent to the UE, a retransmission is received in response to a NACK feedback and a maximum number of retransmissions is reached.

[0007] In some possible embodiments, the step of actively sending the first PDU without a positive acknowledgement (ACK) in the sending window to the UE by using the enhanced strategy comprises: If the current polling timer is started, it is determined whether the polling timer is timed out, wherein during the period when the polling timer is started and not timed out, control signaling carrying a polling identifier is triggered to be sent to the UE; If the polling timer is timed out and a polling response fed back by the UE is not received, the first PDU without an ACK in the sending window is actively sent to the UE by using the enhanced strategy.

[0008] In some possible embodiments, the step of actively sending the first PDU without an ACK in the sending window to the UE by using the enhanced strategy comprises: The first PDU without an ACK in the sending window is actively sent to the UE, and control signaling carrying a polling identifier is sent.

[0009] In some possible embodiments, the step of actively sending the first PDU without an ACK in the sending window to the UE by using the enhanced strategy comprises: The current modulation and coding strategy (MCS) is directly reduced to a preset low-level MCS; The first PDU without an ACK in the sending window is modulated and coded by using the preset low-level MCS at the MAC layer and then sent to the UE.

[0010] In some possible embodiments, the preset low-level MCS is a lowest-level MCS.

[0011] In some possible embodiments, the step of determining that the receiving fails according to the status report fed back by the user terminal (UE) comprises: The number of consecutive NACKs is determined according to the status report fed back by the user terminal (UE); If the number of consecutive NACKs exceeds a set threshold, it is determined that the receiving fails.

[0012] Secondly, embodiments of this application provide an enhanced RLC AM mode reliable transmission apparatus for base stations and repeaters, the apparatus comprising: The SN quantity determination module is used to determine the quantity of sequence numbers (SNs) within the transmission window in response to a data transmission command. The SNs within the transmission window are the SNs of Service Data Units (SDNs) that have been transmitted but have not yet received acknowledgment. The window length determination module is used to determine whether the number of SNs reaches a preset threshold, where the preset threshold is less than the window length. An enhanced strategy sending module is used to actively send the first PDU that has not received a positive ACK in the sending window to the UE using an enhanced strategy when the number of SNs reaches a preset threshold and the sending window is in a blocked state. The PDU includes multiple SDUs. The failure handling module is used to restart the base station / repeater when a reception failure is determined based on the status report fed back by the user terminal UE.

[0013] Thirdly, another embodiment of this application provides an enhanced RLC AM mode reliable transmission apparatus for base stations and repeaters, including at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to execute any of the enhanced RLC AM mode reliable transmission methods for base stations and repeaters provided in the embodiments of this application.

[0014] Fourthly, another embodiment of this application provides a computer storage medium storing a computer program for causing a computer to execute any of the enhanced RLC AM mode reliable transmission methods for base stations and repeaters provided in the embodiments of this application.

[0015] In this embodiment of the application, when it is determined that the transmission window has reached a preset threshold, it means that the transmission window is close to being blocked. The base station / repeater adopts an enhanced strategy to actively send the first PDU in the current transmission window that has not received an ACK confirmation to the UE. If it is determined that the reception has failed based on the status report fed back by the user terminal UE, the higher layer is notified to restart the base station / repeater or to stop sending SDUs, so as to avoid the base station / repeater downtime causing the user to be unable to use the service for a long time.

[0016] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart of an enhanced RLC AM mode reliable transmission method for base stations and repeaters provided according to an embodiment of this application; Figure 2 Detailed diagram of the enhanced RLC AM mode reliable transmission method for base stations and repeaters provided according to embodiments of this application; Figure 3 This is a schematic diagram of an enhanced RLC AM mode reliable transmission device for base stations and repeaters provided according to an embodiment of this application; Figure 4 This is a structural diagram of an enhanced RLC AM mode reliable transmission device for base stations and repeaters provided according to an embodiment of this application. Detailed Implementation

[0019] To further illustrate the technical solutions provided in the embodiments of this application, a detailed description is provided below in conjunction with the accompanying drawings and specific implementation methods. Although the embodiments of this application provide method operation steps as shown in the following embodiments or drawings, more or fewer operation steps may be included in the method based on conventional or non-inventive effort. For steps that do not logically have a necessary causal relationship, the execution order of these steps is not limited to the execution order provided in the embodiments of this application. In actual processing or when the control device executes the method, it may be executed sequentially or in parallel according to the method shown in the embodiments or drawings.

[0020] The RLC (Radio Link Control) layer is located between the PDCP (Packet Data Convergence Protocol) layer and the MAC (Medium Access Control) layer. It communicates with the PDCP layer (or the RRC (Radio Resource Control) layer) through the RLC channel and with the MAC layer through the logical channel. The RLC layer is mainly responsible for functions such as data forwarding, segmentation, retransmission, discarding, and RLC reconstruction. The functions of the RLC layer are implemented by RLC entities, which are created when the RLC bearer is established and deleted when the RLC bearer is released. Each RLC entity is configured by the upper-layer RRC and is divided into three operating modes: transparent mode TM, unacknowledged mode UM, and acknowledged mode AM.

[0021] The AM (Acknowledged Mode) mode is the acknowledged mode, providing a reliable service. The main difference between the AM mode and the UM mode is that it has an ARQ (Automatic Repeat Request) error correction function based on the UM function. That is, after the sender sends the data, it needs to wait for the receiver to reply with an acknowledgment message indicating whether the data has been correctly received. After receiving the acknowledgment message, the sender needs to retransmit the data indicated as received unsuccessfully in the acknowledgment message. Therefore, the AM mode can provide reliable data transmission for the upper layer and ensure that the data is correctly delivered to the peer in sequence. It is mainly applicable to services that are not sensitive to latency but are sensitive to errors, such as FTP services.

[0022] The logical channels corresponding to the AM mode are DTCH (Dedicated Traffic Channel) / DCCH (Dedicated Control Channel), which are used to transmit user-plane data and control-plane data.

[0023] The AM entity maintains the following state variables at the sender: Acknowledgment state variable TX_NEXT_Ack: This variable stores the SN (Serial Number) value of the next RLC SDU (service Data Unit) that is expected to receive a positive acknowledgment in sequence. That is, all RLC SDUs with SN < TX_Next_Ack have been successfully received. This variable corresponds to the lower boundary (including TX_Next_Ack) of the transmit window. This variable is updated when the AM entity receives a positive acknowledgment for an RLC SDU with SN = TX_Next_Ack.

[0024] The transmission window size AM_Window_Size: The constant specifies the size of a transmission window or a reception window and is used at both the transmitting and receiving ends of each AM entity. When a 12-bit SN is configured, AM_Window_Size = 2048; when an 18-bit SN is configured, AM_Window_Size = 131072.

[0025] Transmitting window: If a SN satisfies the following range TX_Next_Ack <= SN <= TX_Next_Ack + AM_window_Size, then the SN is within the transmitting window. The reason is as follows: All RLC SDUs with SN < TX_Next_Ack are considered to have been successfully received by the receiving end, and there is no need to resend these SDUs; Starting from the smallest SN = TX_Next_Ack that has not received a positive acknowledgment, the transmitting end can send at most AM_window_Size RLC SDUs, so the transmitting end will not send RLC SDUs with SN >= TX_Next_Ack + AM_window_Size.

[0026] SN: Used to indicate the sequence number of the corresponding RLC SDU. The SN field of an AM RLC entity is 12 bits or 18 bits long. The RRC layer configures it through the sn-FieldLength field. By default, the SN is 12 bits long. Different from UM, in the AM mode, the header of each RLC SDU contains a SN. Therefore, in the AM mode, for each new RLC SDU, the SN value is incremented by one.

[0027] In view of the problem that the related technology cannot delete the data in the memory cache when the transmission window is blocked, and since the high layer continuously sends data to the cache, eventually the base station / repeater crashes due to the exhaustion of memory. This application proposes an enhanced RLC AM mode reliability transmission method and device for base stations and repeaters that can avoid the long-term inability of users to use due to the crash of the base station / repeater.

[0028] Other features and advantages of this application will be described in the subsequent specification, and, in part, will be obvious from the specification or will be understood by implementing this application. The objectives and other advantages of this application can be achieved and obtained through the structures specifically pointed out in the written specification, claims, and drawings.

[0029] The following will describe in detail the enhanced RLC AM mode reliability transmission method and device for base stations and repeaters in the embodiments of this application with reference to the accompanying drawings.

[0030] like Figure 1 The diagram shown is a flowchart of an enhanced RLC AM mode reliable transmission method for base stations and repeaters provided in this application embodiment, which mainly includes: Step 101: In response to the data transmission command, determine the number of sequence numbers (SNs) within the transmission window, wherein the SNs within the transmission window are the SNs of Service Data Units (SDNs) that have been transmitted but have not yet received acknowledgment; In this embodiment, the base station / repeater receives data sent from the higher layer. Specifically, the data sent from the higher layer is an RLC SDU. After receiving the RLC SDU sent from the higher layer, an RLC header is generated for each RLC SDU and cached in the transmission buffer. The data in the transmission buffer is also cached in the retransmission queue. The transmission buffer is used to interact with the higher layer. When the RLC layer sends data, it can directly retrieve the data from the retransmission queue without retrieving the data from the transmission buffer. However, both the transmission buffer and the retransmission queue will occupy memory.

[0031] In this embodiment, each time the base station / repeater sends data to the UE, it determines whether the sending window will be full if the serial number (SN) of the SDU to be sent is included, based on the current sending window length. If the sending window length is exceeded, it is considered that data cannot be sent. Therefore, this embodiment first determines the number of serial numbers (SNs) within the sending window before sending data.

[0032] Step 102: Determine whether the number of SNs has reached a preset threshold, where the preset threshold is less than the window length; if the number of SNs has reached the preset threshold, proceed to step 103. In this embodiment of the application, the preset threshold is a value less than the window length. The preset threshold can be determined in the following way: based on the number of SNs in the current sending window, predict that the length of the sending window after sending data will be close to the window length, that is, the difference between the length of the sending window and the window length is less than the set threshold. Then it is determined that the sending window will be blocked, and the number of SNs in the current sending window is determined as the preset threshold.

[0033] Under normal circumstances, the SN within the transmission window is mobile. If there is no network congestion with the higher layers and the ACK from the UE can be received correctly, the SN will be deleted after sending the corresponding SN SDU and receiving the ACK from the UE, and the corresponding SN SDU will be deleted from the retransmission queue. Therefore, after the deletion of the SN within the transmission window, data transmission can be supported, and the remaining memory space increases, which can support the correct reception of data from the higher layers.

[0034] However, the inability to correctly receive downlink data from higher layers may occur in the following two situations: Scenario 1: Due to network congestion with higher layers, after successfully sending the SDU of a certain SN, the data of the next SN has not yet been received from the higher layer, that is, the SDU is not in the retransmission queue. In this case, a timeout timer will be started to wait. If the corresponding SN's SDU is not received after the timer expires, the SN will be removed from the sending window and the data of the next SN will be sent. However, if the timeout timer is started frequently, it will cause the memory to be continuously exhausted and crash, making it impossible to receive data correctly from the higher layer.

[0035] Scenario 2: When an SDU from a certain SN is sent to the UE, it retransmits data upon receiving a NACK response. If the maximum number of retransmissions is reached and no ACK response is received from the UE, it will continue to wait instead of sending the next batch of data. This will cause the memory to be continuously exhausted, leading to a system crash and preventing the correct reception of data from higher layers.

[0036] Step 103: If the number of SNs reaches a preset threshold, an enhanced strategy is adopted to actively send the first PDU in the transmission window that has not received a positive ACK to the UE. The PDU includes multiple SDUs. If the number of SNs in the transmission window reaches a preset threshold, it indicates that the transmission window is close to being blocked after data transmission. Therefore, in this embodiment of the application, when the transmission window is close to being blocked, data will not be transmitted first. Instead, an enhanced strategy is adopted to actively transmit the first PDU in the transmission window that has not received a positive ACK to the UE. The above-mentioned enhanced strategy is a strategy that can improve the probability of the UE successfully responding to the base station / repeater. When the base station / repeater transmits data to the UE, it transmits it in the form of PDUs. One PDU includes multiple SDUs. Therefore, in this embodiment of the application, an enhanced strategy is adopted to actively transmit the first PDU in the current transmission window that has not received a positive ACK to the UE.

[0037] Step 104: If a reception failure is determined based on the status report fed back by the user terminal UE, the base station / repeater is restarted or the higher layer is notified to stop transmitting SDU.

[0038] This application proposes an enhanced RLC AM mode reliable transmission method for base stations and repeaters. When an RLC entity receives a data packet from a higher layer, it determines whether the transmission window has reached a preset threshold. If the threshold is reached, the transmission window is nearing congestion. The transmitter actively sends the first PDU within the transmission window that has not received an ACK, carrying a P-polling field, to the receiver. If the receiver's status report indicates reception failure, the base station / repeater is restarted or the higher layers are notified to stop transmitting SDUs, preventing base station / repeater downtime and prolonged user downtime.

[0039] In some possible embodiments, if the number of SNs reaches a preset threshold, step 105 is executed, the PDU in the buffer is sent, the SN of the SDU in the sent PDU is added to the sending window, and when the ACK confirmation is received from the UE, the corresponding SN in the sending window and the corresponding PDU in the buffer are deleted. When the NACK feedback is received, the PDU is retransmitted. The specific process adopts relevant technical methods, which will not be repeated here.

[0040] In some possible embodiments, determining reception failure based on the status report fed back by the user terminal UE includes: determining the number of consecutive NACKs received based on the status report fed back by the user terminal UE; if the number of consecutive NACKs received exceeds a set threshold, reception failure is determined. In this embodiment, multiple SDUs are encapsulated into a PDU. When the base station / repeater actively sends the first PDU in the current transmission window that has not received a positive ACK to the UE, the UE provides a status report for each SDU. Based on the received status reports, if the base station / repeater does not receive a status report for an SDU, it records a NACK event. If the number of NACK events exceeds a set threshold, reception failure is considered. The base station / repeater is then restarted or a higher layer is notified to stop transmitting SDUs.

[0041] In some possible embodiments, if the number of SNs reaches a preset threshold, the following steps are also included: The SDU corresponding to the smallest SN within the sending window is not in the cache, and a timeout timer is enabled; After the SDU corresponding to the smallest SN within the transmission window is sent to the UE, a NACK feedback is received for retransmission and the maximum number of retransmissions is reached.

[0042] After performing any of the above steps, it is determined that the transmission window is close to a blocking state, and an enhanced strategy is adopted to actively send the first PDU in the transmission window that has not received a positive ACK to the UE.

[0043] In some possible embodiments, an enhanced strategy is employed to proactively send the first PDU within the transmission window that has not received a positive ACK to the UE, including: If a polling timer is currently active, it is determined whether the polling timer has timed out. During the period when the polling timer is active and has not timed out, a control signaling carrying a polling identifier is sent to the UE. Depending on the protocol, the polling timer may be activated when certain conditions are met. When the polling timer is activated, the base station / repeater will send a control signaling carrying a polling identifier to the UE. In this way, even if the UE only receives the control signaling carrying the polling identifier but does not receive the SDU data, it will still poll the base station / repeater, thereby stimulating the transmission window to move. If the polling timer times out and no polling response is received from the UE, an enhanced strategy is adopted to actively send the first PDU in the sending window that has not received a positive ACK to the UE. When the sending window reaches a preset threshold, this application further determines whether the polling timer is currently running. If the polling timer is not running, the enhanced strategy is adopted to actively send the first PDU in the sending window that has not received a positive ACK to the UE. If the polling timer is currently running, the application waits until the polling timer times out. If no polling response is received from the UE, the enhanced strategy is adopted to actively send the first PDU in the sending window that has not received a positive ACK to the UE.

[0044] In some possible embodiments, an enhanced strategy is employed to proactively send the first PDU within the transmission window that has not received a positive acknowledgment (ACK) to the UE. This includes: proactively sending the first PDU within the transmission window that has not received a positive acknowledgment (ACK) to the UE, and sending control signaling carrying a polling identifier. In this embodiment, when proactively sending the first PDU that has not received an ACK, control signaling carrying a polling identifier is sent. This ensures that even if the UE receives only control signaling without receiving data, it will still poll the base station / repeater, preventing the base station / repeater from continuously waiting for SN acknowledgment and thus avoiding the inability to correctly receive data from higher layers.

[0045] The RLC layer has a maximum number of retransmissions. If the maximum number of retransmissions is reached without receiving confirmation of successful reception from the receiver, downlink data transmission to higher layers will fail, ultimately leading to base station / repeater downtime due to memory exhaustion. This application provides an enhanced RLC AM mode reliable transmission method for base stations and repeaters. In the AM entity, after the RLC entity receives a data packet from a higher layer, it determines whether the transmission window has reached a preset threshold. If the preset threshold has been reached, it means the transmission window is nearing blockage. The transmitter actively sends the first PDU in the current transmission window that has not received an ACK confirmation, along with a P polling field, to the receiver. If the number of consecutive NACK loss events in the receiver's status report is greater than or equal to a set threshold, the base station / repeater is automatically restarted or the higher layers are notified to stop sending SDUs, preventing base station / repeater downtime and prolonged user downtime.

[0046] In some possible embodiments, an enhanced strategy is employed to proactively send the first PDU within the transmission window that has not received a positive acknowledgment (ACK) to the UE. This includes: directly reducing the current modulation and coding scheme (MCS) to a preset low-level MCS; and using the preset low-level MCS at the MAC layer to modulate and code the first PDU within the transmission window that has not received a positive acknowledgment (ACK) before sending it to the UE. According to the adaptive coding adjustment method in relevant technologies, to improve the UE's reception accuracy, an adaptive approach can be used to adjust the MAC level. However, the embodiments of this application directly reduce the current MCS to a preset low-level MCS, which can significantly improve the UE's reception accuracy. In some possible embodiments, the aforementioned preset low-level MCS is the lowest level MCS.

[0047] The following is combined with Figure 2 This application provides a detailed flowchart of the enhanced RLC AM mode reliable transmission method for base stations and repeaters, as illustrated in the embodiments of this application. Figure 2 As shown, it mainly includes: Step 201: DRB (Data Radio Bearer) bearers are generally established when the base station / repeater sends a reconfiguration message. Therefore, when the base station / repeater sends a reconfiguration message to establish the DRB bearer, the RLC entity is configured to AM mode in rlc-Config of RLC-BearerConfig in the RLC radio configuration. Step 202: After receiving the data packet from the higher layer, the sending end generates an RLC header for each RLC SDU and buffers it in the transmission buffer, and retrieves the data from the transmission buffer and buffers it in the retransmission queue, triggering a data transmission command. Step 203: In response to the data transmission command, determine whether the number of SNs in the transmission window has reached a preset threshold. The preset threshold may be set to a value close to the fullness of the window. If the preset threshold is reached, proceed to step 212. If the preset threshold is not reached, proceed to step 204. Step 204: Determine whether the transmission size indicated by the MAC layer matches the size of the RLC PDU to be transmitted. If they match, proceed to step 205; otherwise, proceed to step 206. When the MAC layer notifies the AM entity of a transmission opportunity, it also informs the AM entity of the total size of all RLC PDUs that can be transmitted during this transmission opportunity. The RLC entity will only directly send the complete RLC PDU if the total size of all RLC PDUs specified by the MAC layer exactly matches the total size of all RLC PDUs that can be sent in the retransmission queue; otherwise, the RLC entity needs to segment a certain RLC SDU so that the total size of all RLC PDUs participating in this transmission matches the size specified by the MAC layer.

[0048] Step 205: If the total size of the RLC PDUs that can be sent in the retransmission queue is exactly equal to or less than the total size specified by the MAC, then send the RLC PDUs that can be sent in the retransmission queue directly, then update the relevant status variables of the sender, such as the SN variable in the sending window, and then execute step 208.

[0049] Step 206: If the total size of the RLC PDUs that can be sent in the retransmission queue is greater than the total size specified by the MAC, then the last RLC PDU segment that can be sent completely will be regenerated into a new PDU to match the size indicated by the MAC, so that the total size of all RLC PDUs participating in this transmission matches the size specified by the MAC layer.

[0050] After segmentation in steps 207 and 206, all RLC PDUs matching the size specified by the MAC are sent to the receiving end, and the relevant status variables of the sending end are updated.

[0051] Step 208: Receive the status report fed back by the receiving end.

[0052] Step 209: parse the ACK and NACK status in the status report. If it is ACK, proceed to step 210; if it is NACK, proceed to step 211.

[0053] Step 210: If the status report is ACK, delete the RLCPDU corresponding to the SN placed in the retransmission queue in step 202, and update the relevant status variables of the receiver.

[0054] Step 211: If the status report is NACK, then the RLC PDU of the corresponding SN in step 202 is retransmitted in the retransmission queue according to the size specified by the MAC, and then step 208 is executed.

[0055] Step 212: Following the judgment in step 203, if the number of SNs in the sending window has reached the preset threshold, and it is determined that the polling timer is currently running, then continue to determine whether the polling timer has timed out. If the polling timer has not timed out, continue to wait; if the polling timer has timed out, proceed to step 213.

[0056] Step 213: If the polling timer has expired, select the first PDU in the sending window that has not received an ACK confirmation and send it actively, carrying the P polling identifier.

[0057] Step 214: Receive the status report sent by the receiving end. If the status report only reports NACK, record the cumulative number K of consecutive NACK loss events.

[0058] Step 215: Determine whether the cumulative number K of consecutive NACK loss events is greater than or equal to the preset threshold N. If so, proceed to step 216.

[0059] Step 216: If the cumulative number K of consecutive NACK loss events is greater than or equal to the preset threshold N, then notify the MAC layer that a state feedback NACK loss event has occurred.

[0060] Step 217: The MAC layer receives the notification from the RLC layer, quickly adjusts the MCS (Modulation and Coding Scheme) level to 0, and then retransmits.

[0061] Step 218: The RLC layer receives the status report from the receiver again. If the status report still shows NACK, the base station / repeater is restarted or the higher layers are notified to stop sending SDU.

[0062] The enhanced RLC AM mode reliable transmission method for base stations and repeaters provided in this application, through the overall approach and method of active polling + feedback loss detection + cross-layer MCS adjustment, demonstrates a feasible cross-layer optimization approach through RLC+MAC layer interaction in 5G / 6G systems, which has application value for future evolution. The method uses a preset threshold for the sending window and a polling timer as specific triggering conditions for active polling, obtaining feedback information from the peer in the early stages of link deterioration, thereby ensuring the continuity and stability of RLC transmission. The specific implementation of the feedback loss detection (timer monitoring, NACK cumulative counting) promptly detects feedback link anomalies, preventing the sending end from continuously waiting for ACK / NACK, leading to service stagnation or resource exhaustion. The triggering logic for cross-layer MCS adjustment in this application (retransmission number threshold / Compared to conventional AMC which only adjusts based on overall channel quality, this mechanism (NACK loss event) can significantly enhance the reliable transmission of critical control PDUs. The cross-layer interaction interface for notification from the RLC layer to the MAC layer in this application effectively shortens the cross-layer response path, enabling the system to quickly adapt to scenarios with high reliability requirements and improving the overall network robustness.

[0063] Based on the same inventive concept, this application also provides an enhanced RLC AM mode reliable transmission device for base stations and repeaters, such as... Figure 3 As shown, the device includes: The SN quantity determination module 301 is used to determine the quantity of sequence numbers (SNs) within the transmission window in response to a data transmission command. The SNs within the transmission window are the SNs of Service Data Units (SDNs) that have been transmitted but have not yet received acknowledgment. The window length determination module 302 is used to determine whether the number of SNs reaches a preset threshold, wherein the preset threshold is less than the window length. The enhanced strategy sending module 303 is used to actively send the first PDU that has not received a positive ACK within the sending window to the UE using an enhanced strategy if the number of SNs reaches a preset threshold. The PDU includes multiple SDUs. The failure handling module 304 is used to restart the base station / repeater or notify the higher layer to stop sending SDU when the reception failure is determined based on the status report fed back by the user terminal UE.

[0064] In some possible embodiments, if the number of SNs reaches a preset threshold, the window length determination module further includes any of the following steps: The SDU corresponding to the smallest SN within the sending window is not in the cache, and a timeout timer is enabled; After the SDU corresponding to the smallest SN within the transmission window is sent to the UE, a NACK feedback is received for retransmission and the maximum number of retransmissions is reached.

[0065] In some possible embodiments, the enhancement policy sending module actively sends the first PDU within the sending window that has not received a positive ACK to the UE using an enhancement policy, including: If a polling timer is currently active, determine whether the polling timer has timed out. During the period when the polling timer is active and has not timed out, trigger the sending of control signaling carrying a polling identifier to the UE. If the polling timer times out and no polling response is received from the UE, an enhanced strategy is adopted to actively send the first PDU in the sending window that has not received a positive ACK to the UE.

[0066] In some possible embodiments, the enhancement policy sending module actively sends the first PDU within the sending window that has not received a positive ACK to the UE using an enhancement policy, including: Actively send the first PDU within the transmission window that has not received a positive ACK to the UE, and send control signaling carrying a polling identifier.

[0067] In some possible embodiments, the enhancement policy sending module actively sends the first PDU within the sending window that has not received a positive ACK to the UE using an enhancement policy, including: The current modulation and coding scheme MCS is directly reduced to a preset low level MCS; At the MAC layer, the first PDU that has not received a positive ACK within the transmission window is modulated and encoded using the preset low-level MCS and then sent to the UE.

[0068] In some possible embodiments, the preset low-level MCS is the lowest level MCS.

[0069] In some possible embodiments, the failure handling module determines reception failure based on the status report fed back by the user terminal UE, including: Based on the status report fed back by the user terminal UE, determine the number of consecutive NACKs received; If the number of consecutive NACKs received exceeds the set threshold, the reception is considered to have failed.

[0070] Having introduced the enhanced RLC AM mode reliable transmission method and apparatus for base stations and repeaters according to exemplary embodiments of this application, the enhanced RLC AM mode reliable transmission apparatus for base stations and repeaters according to another exemplary embodiment of this application will now be introduced.

[0071] Those skilled in the art will understand that various aspects of this application can be implemented as a system, method, or program product. Therefore, various aspects of this application can be specifically implemented in the following forms: a completely hardware implementation, a completely software implementation (including firmware, microcode, etc.), or a combination of hardware and software implementations, collectively referred to herein as a "circuit," "module," or "system."

[0072] In some possible implementations, the enhanced RLC AM mode reliable transmission apparatus for base stations and repeaters according to this application may include at least one processor and at least one memory. The memory stores program code that, when executed by the processor, causes the processor to perform the steps of the enhanced RLC AM mode reliable transmission method for base stations and repeaters according to the various exemplary embodiments of this application described above.

[0073] The following reference Figure 4 This application describes an enhanced RLCAM mode reliable transmission apparatus 140 for base stations and repeaters according to this embodiment. Figure 4The illustrated enhanced RLC AM mode reliable transmission device 140 for base stations and repeaters is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.

[0074] like Figure 4 As shown, the enhanced RLC AM mode reliable transmission device 140 for base stations and repeaters is presented in the form of general electronic equipment. The components of the enhanced RLC AM mode reliable transmission device 140 for base stations and repeaters may include, but are not limited to: at least one processor 141, at least one memory 142, and a bus 143 connecting different system components (including memory 142 and processor 141).

[0075] Bus 143 represents one or more of several bus structures, including a memory bus or memory controller, peripheral bus, processor, or local bus using any of the various bus structures.

[0076] The memory 142 may include a readable medium in the form of volatile memory, such as random access memory (RAM) 1421 and / or cache memory 1422, and may further include read-only memory (ROM) 1423.

[0077] The memory 142 may also include a program / utility 1425 having a set (at least one) of program modules 1424, including but not limited to: an operating system, one or more application programs, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.

[0078] The enhanced RLC AM mode reliability transmission device 140 for base stations and repeaters can also communicate with one or more external devices 144 (e.g., keyboards, pointing devices, etc.), one or more devices that enable users to interact with the enhanced RLC AM mode reliability transmission device 140 for base stations and repeaters, and / or any device that enables the enhanced RLC AM mode reliability transmission device 140 for base stations and repeaters to communicate with one or more other electronic devices (e.g., routers, modems, etc.). This communication can be performed via input / output (I / O) interface 145. Furthermore, the enhanced RLC AM mode reliability transmission device 140 for base stations and repeaters can also communicate with one or more networks (e.g., local area networks (LANs), wide area networks (WANs), and / or public networks, such as the Internet) via network adapter 146. As shown, network adapter 146 communicates with other modules of the enhanced RLC AM mode reliability transmission device 140 for base stations and repeaters via bus 143. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the enhanced RLC AM mode reliable transmission device 140 for base stations and repeaters, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0079] In some possible implementations, various aspects of the enhanced RLC AM mode reliable transmission method for base stations and repeaters provided in this application can also be implemented in the form of a program product, which includes program code. When the program product is run on a computer device, the program code is used to cause the computer device to perform the steps in the enhanced RLC AM mode reliable transmission method for base stations and repeaters according to various exemplary embodiments of this application described above.

[0080] The program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0081] The monitoring program product of the embodiments of this application may employ a portable compact disc read-only memory (CD-ROM) and include program code, and may run on an electronic device. However, the program product of this application is not limited thereto. In this document, the readable storage medium may be any tangible medium that contains or stores a program that may be used by or in conjunction with an instruction execution system, apparatus, or device.

[0082] A readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying readable program code. This propagated data signal may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of sending, propagating, or transmitting a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0083] The program code contained on the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0084] Program code for performing the operations of this application can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's electronic device, partially on the user's device, as a standalone software package, partially on the user's electronic device and partially on a remote electronic device, or entirely on a remote electronic device or server. In cases involving remote electronic devices, the remote electronic device can be connected to the user's electronic device via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external electronic device (e.g., via the Internet using an Internet service provider).

[0085] It should be noted that although several units or sub-units of the device have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of this application, the features and functions of two or more units described above can be embodied in one unit. Conversely, the features and functions of one unit described above can be further divided and embodied by multiple units.

[0086] Furthermore, although the operations of the method of this application are described in a specific order in the accompanying drawings, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0087] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0088] This application is described with reference to flowchart illustrations and block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block and / or segment of the flowchart illustrations and block diagrams, as well as combinations of blocks and segments in the flowchart illustrations and block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart. Figure 1 One or more processes and boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0089] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and boxes Figure 1 The function specified in one or more boxes.

[0090] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and boxes Figure 1 The steps of the function specified in one or more boxes.

[0091] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0092] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method for enhanced RLC AM mode reliable transmission for base stations and repeaters, characterized in that, The method includes: In response to a data transmission command, determine the number of sequence numbers (SNs) within the transmission window, wherein the SNs within the transmission window are the SNs of Service Data Units (SDNs) that have been transmitted but have not yet received acknowledgment; Determine whether the number of SNs reaches a preset threshold, where the preset threshold is less than the window length; If the number of SNs reaches a preset threshold, an enhanced strategy is adopted to actively send the first PDU in the transmission window that has not received a positive ACK to the UE. The PDU includes multiple SDUs. When a reception failure is determined based on the status report fed back by the user terminal (UE), the base station / repeater is restarted or the higher layer is notified to stop transmitting SDU.

2. The method according to claim 1, characterized in that, If the number of SNs reaches a preset threshold, the method further includes any of the following steps: The SDU corresponding to the smallest SN within the sending window is not in the cache, and a timeout timer is enabled; After the SDU corresponding to the smallest SN within the transmission window is sent to the UE, a NACK feedback is received for retransmission and the maximum number of retransmissions is reached.

3. The method according to claim 1, characterized in that, The step of actively sending the first PDU within the transmission window that has not received a positive ACK to the UE using an enhanced strategy includes: If a polling timer is currently active, determine whether the polling timer has timed out. During the period when the polling timer is active and has not timed out, trigger the sending of control signaling carrying a polling identifier to the UE. If the polling timer times out and no polling response is received from the UE, an enhanced strategy is adopted to actively send the first PDU in the sending window that has not received a positive ACK to the UE.

4. The method according to claim 1, characterized in that, The step of actively sending the first PDU within the transmission window that has not received a positive ACK to the UE using an enhanced strategy includes: Actively send the first PDU within the transmission window that has not received a positive ACK to the UE, and send control signaling carrying a polling identifier.

5. The method according to any one of claims 1 to 4, characterized in that, The step of actively sending the first PDU within the transmission window that has not received a positive ACK to the UE using an enhanced strategy includes: The current modulation and coding scheme MCS is directly reduced to a preset low level MCS; At the MAC layer, the first PDU that has not received a positive ACK within the transmission window is modulated and encoded using the preset low-level MCS and then sent to the UE.

6. The method according to claim 5, characterized in that, The preset low-level MCS is the lowest level MCS.

7. The method according to claim 1, characterized in that, The step of determining reception failure based on the status report fed back by the user terminal UE includes: Based on the status report fed back by the user terminal UE, determine the number of consecutive NACKs received; If the number of consecutive NACKs received exceeds the set threshold, the reception is considered to have failed.

8. An enhanced RLC AM mode reliable transmission device for base stations and repeaters, characterized in that, The device includes: The SN quantity determination module is used to determine the number of sequence numbers (SNs) within the transmission window in response to a data transmission command. The SNs within the transmission window are the SNs of Service Data Units (SDNs) that have been transmitted but have not yet received acknowledgment. The window length determination module is used to determine whether the number of SNs reaches a preset threshold, wherein the preset threshold is less than the window length. An enhanced strategy sending module is used to actively send the first PDU that has not received a positive ACK in the sending window to the UE using an enhanced strategy when the number of SNs reaches a preset threshold and the sending window is in a blocked state. The PDU includes multiple SDUs. The failure handling module is used to restart the base station / repeater or notify higher layers to stop transmitting SDU when a reception failure is determined based on the status report fed back by the user terminal UE.

9. An enhanced RLC AM mode reliable transmission device for base stations and repeaters, characterized in that, The method includes at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the method as described in any one of claims 1-7.

10. A computer storage medium, characterized in that, The computer storage medium stores a computer program that enables the computer to perform the method as described in any one of claims 1-7.

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