Retransmission enhancement method and communication apparatus

Abstract

The present application relates to the technical field of communications, and discloses a retransmission enhancement method and a communication apparatus. The method comprises: determining first information; and executing a first retransmission enhancement scheme according to the first information. Executing a retransmission enhancement scheme allows for a retransmission mechanism to be enhanced, thereby improving retransmission timeliness with respect to data packets that have not been successfully received, effectively limiting data packet loss, and improving data transmission success rates. Moreover, selecting execution of a first retransmission enhancement scheme according to first information improves flexibility with respect to executing retransmission enhancement schemes. This allows data transmission performance to be optimized, and in particular, helps ensure reliability and effectiveness of data transmission for services with short PDBs, such as XR.

Description

Retransmission enhancement method and communication device

[0001] This application claims priority to Chinese Patent Application No. 202510035169.9, filed with the State Intellectual Property Office of China on January 8, 2025, entitled “Retransmission Enhancement Method and Communication Apparatus”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communication technology, and in particular to a retransmission enhancement method and communication device. Background Technology

[0003] Currently, in order to achieve reliable data transmission, an ACK / NACK (acknowledgment / negative acknowledgment) mechanism has been introduced into the Radio Link Control (RLC) layer of the device. Based on the ACK / NACK mechanism, the receiver can acknowledge or deny the received data packets, and the sender can retransmit unacknowledged data packets according to the received ACK / NACK information to limit data packet loss and ensure data integrity and accuracy.

[0004] However, for services with short packet delay budgets (PDB), such as XR services, this retransmission mechanism may not be able to retransmit packets in a timely manner, affecting the reliability and performance of data transmission. Summary of the Invention

[0005] This application provides a retransmission enhancement method and communication device, which can improve the timeliness of data packet retransmission, effectively limit data packet loss, and thus improve the reliability and performance of data transmission.

[0006] Firstly, a method is provided, which can be executed by a terminal device, or by a component (such as a circuit, chip, or chip system) configured in the terminal device, or by a logic module or software capable of implementing all or part of the functions of the terminal device. This application does not limit this approach. The following description uses a terminal device as an example.

[0007] The method includes: determining first information; and executing a first retransmission enhancement scheme based on the first information.

[0008] By implementing retransmission enhancement schemes, the retransmission mechanism can be strengthened, thereby improving the timeliness of retransmitting unreceived data packets. This effectively limits data packet loss and increases the data transmission success rate. Furthermore, by selecting the first retransmission enhancement scheme based on the first information, the flexibility of implementing retransmission enhancement schemes can be improved. This optimizes data transmission performance, particularly helping to ensure the reliability and effectiveness of data transmission for services with short PDBs, such as XR applications.

[0009] Optionally, the first retransmission enhancement scheme is one of a variety of retransmission enhancement schemes, including at least two of the following: polling enhancement scheme, autonomous retransmission scheme, priority polling enhancement scheme, and priority autonomous retransmission scheme.

[0010] Among them, the polling enhancement scheme and the autonomous retransmission scheme are two single retransmission enhancement schemes.

[0011] Polling enhancement schemes refer to strengthening the polling mechanism. For example, additional triggering conditions can be added beyond the existing ones to increase the polling frequency. Implementing these enhancements helps obtain receiver status reports more promptly, enabling retransmissions based on these reports and improving both the timeliness of retransmissions and the success rate of data packet transmission.

[0012] The autonomous retransmission scheme refers to stateless retransmission, meaning that data packets are retransmitted even without a NACK received, thereby increasing the retransmission trigger frequency. Implementing the autonomous retransmission scheme helps to retransmit data packets in a timely manner, avoiding situations where data packets are dropped because the packet delay budget may have been reached after a NACK is received, thus improving the timeliness of retransmission and the success rate of data packet transmission.

[0013] Among them, the priority polling enhancement scheme and the priority autonomous retransmission scheme are two joint retransmission enhancement schemes. The joint retransmission enhancement scheme means that the polling enhancement scheme and the autonomous retransmission scheme can be executed together when the retransmission enhancement scheme is implemented.

[0014] The priority polling enhancement scheme prioritizes the execution of the polling enhancement scheme, and only executes the autonomous retransmission scheme if no status report is received when the triggering conditions for the autonomous retransmission scheme are met. By implementing the priority polling enhancement scheme, it helps to obtain the receiver's status report in a timely manner through polling, enabling retransmission based on the status report. Furthermore, it allows for timely retransmission of data packets even if a status report is not obtained promptly after polling, thereby further improving the timeliness of data packet retransmission and the success rate of data packet transmission.

[0015] The priority autonomous retransmission scheme refers to prioritizing the execution of the autonomous retransmission scheme and triggering the polling enhancement scheme during its execution, or prioritizing the execution of the autonomous retransmission scheme and, if no status report has been received when the triggering conditions for the polling enhancement scheme are met, then executing the polling enhancement scheme. By implementing the priority autonomous retransmission scheme, data packets can be retransmitted promptly, and the receiver's status report can be obtained in a timely manner. Retransmission is then based on the status report, thereby further improving the timeliness of data packet retransmission and the success rate of data packet transmission.

[0016] Optionally, the first information includes first instruction information sent by the network device and / or judgment information of the terminal device itself.

[0017] In this way, the first device can execute the retransmission enhancement scheme according to the instructions of the network device, or it can execute the retransmission enhancement scheme according to the judgment information of the terminal device itself, which improves the flexibility of the terminal device in executing the retransmission enhancement scheme.

[0018] Optionally, the first indication information is used to indicate whether a retransmission enhancement scheme is used, and / or to indicate the retransmission enhancement scheme that needs to be used.

[0019] Optionally, the first indication information includes the retransmission enhancement scheme activation status or the retransmission enhancement scheme deactivation status. The retransmission enhancement scheme activation status includes one or more of the following: polling enhancement scheme activation status, autonomous retransmission activation status, priority polling enhancement scheme activation status, and priority retransmission enhancement scheme activation status.

[0020] Among them, the activation status of the polling enhancement scheme is used to indicate the activation of the polling enhancement scheme; the activation status of the autonomous retransmission scheme is used to indicate the activation of the autonomous retransmission scheme; the activation status of the priority polling enhancement scheme is used to indicate the activation of the priority polling enhancement scheme; and the activation status of the priority autonomous retransmission scheme is used to indicate the activation of the priority autonomous retransmission scheme.

[0021] In this way, the terminal device can execute different retransmission enhancement schemes according to the different retransmission enhancement scheme activation states carried by the first indication information, thereby improving the flexibility of the terminal device in executing retransmission enhancement schemes.

[0022] Optionally, the first indication information is used to indicate whether a retransmission enhancement scheme is used. For example, the first indication information includes a retransmission enhancement scheme activation status or a retransmission enhancement scheme deactivation status.

[0023] Optionally, the first indication information is used to indicate whether a retransmission enhancement scheme is used, and to indicate the retransmission enhancement scheme to be used among multiple retransmission enhancement schemes. For example, the first indication information includes a retransmission enhancement scheme activation status or a retransmission enhancement scheme deactivation status. The retransmission enhancement scheme activation status may include the activation status of any one of the multiple retransmission enhancement schemes.

[0024] Optionally, the first retransmission enhancement scheme is implemented, including: if the first retransmission enhancement scheme includes a polling enhancement scheme, triggering the polling enhancement scheme based on a first triggering condition; wherein the first triggering condition includes at least one of the following triggering conditions: the remaining lifetime of the data packets in the transmission window is less than or equal to a certain duration threshold, the data packets in the transmission window are indicated as delayed critical data packets, the number of PDUs or bytes sent reaches a certain number threshold, the number of SNs sent reaches a certain number threshold, the transmission buffer and / or retransmission buffer is empty, the polling retransmission timer times out, the polling retransmission timer times out and no status report is received, and triggering in the last transmission of the PDU set.

[0025] This expands the triggering methods for the polling enhancement scheme and improves the flexibility of triggering the polling enhancement scheme.

[0026] Optionally, the first retransmission enhancement scheme is implemented, including: if the first retransmission enhancement scheme includes an autonomous retransmission scheme, triggering the autonomous retransmission scheme based on a second triggering condition; wherein the second triggering condition includes at least one of the following triggering conditions: the remaining lifetime of the data packet in the transmission window is less than or equal to a certain duration threshold, triggering for a delay-critical data packet, triggering for a PDU whose importance in the PDU set meets the requirements, triggering for a PDU in an unknown state in the PDU set after the initial transmission of all PDUs in the PDU set is completed, triggering for a delay-critical data packet when the polling retransmission timer times out, triggering when the transmission gap or channel quality meets the requirements, and triggering when the data stream ends or the transmission window stops.

[0027] This expands the triggering methods for the autonomous retransmission scheme and improves the flexibility of the triggering polling enhancement scheme.

[0028] Optionally, the polling enhancement scheme satisfies at least one of the following conditions compared to ordinary polling: subject to different prohibition timers, corresponding to different trigger condition parameters, allowing the receiving entity to handle the reassembly timer and / or prohibition timer in different ways, enhancing the retransmission procedure after receiving a status report based on polling enhancement, and stopping the polling enhancement of the corresponding RLC entity when the packet delay budget (PDB) of the service data stream is reached.

[0029] This allows the enhanced polling scheme to obtain status reports more promptly than ordinary polling, thereby improving the timeliness of data retransmission.

[0030] Optionally, the autonomous retransmission scheme satisfies at least one of the following conditions compared to ordinary retransmission: the transmission priority of autonomous retransmission is higher than that of ordinary retransmission; transmission resources for autonomous retransmission are scheduled after all PDUs of a burst are transmitted; and autonomous retransmission of the corresponding RLC entity is stopped when the PDB of the service data stream is reached.

[0031] This allows the autonomous retransmission scheme to retransmit data packets more promptly than ordinary retransmission, thereby improving the timeliness of data retransmission.

[0032] Optionally, if the first indication information includes the retransmission enhancement scheme activation status, the first indication information also includes configuration information corresponding to the retransmission enhancement scheme activation status. The configuration information includes parameters related to the triggering conditions of the retransmission enhancement scheme activated by the retransmission enhancement scheme activation status. Executing the first retransmission enhancement scheme according to the first indication information includes: triggering the first retransmission enhancement scheme according to the retransmission enhancement scheme activation status and the configuration information.

[0033] In this way, the network device can also instruct the first device to trigger the retransmission enhancement scheme by using the first indication information, thereby further improving the flexibility of the terminal device in executing the retransmission enhancement scheme.

[0034] Optionally, if the activation status of the retransmission enhancement scheme indicates that the activated retransmission enhancement scheme includes a polling enhancement scheme, the configuration information includes first configuration information corresponding to the polling enhancement scheme. The first configuration information includes at least one of the following: trigger duration threshold, trigger count threshold, trigger period, and sequence number period.

[0035] Optionally, when the activation status of the retransmission enhancement scheme indicates that the activated retransmission enhancement scheme includes an autonomous retransmission scheme, the configuration parameters include second configuration information corresponding to the autonomous retransmission scheme. The second configuration information includes at least one of the trigger duration threshold, the trigger channel quality threshold, and the trigger transmission gap length.

[0036] Optionally, before executing the first retransmission enhancement scheme according to the first information, the method further includes: obtaining configuration information of the network device configuration, the configuration information including at least one trigger duration threshold, and a first timer and / or timing parameters of the first timer, the first timer being used to determine the remaining lifetime of the data packet; executing the first retransmission enhancement scheme according to the first information, including: triggering the first retransmission enhancement scheme based on the remaining lifetime of the data packet according to the first information and the configuration information.

[0037] In this way, the specific implementation of the retransmission enhancement scheme can be limited to triggering based on the remaining lifetime of the data packet, and the triggering time threshold for the terminal device to trigger the retransmission enhancement scheme can be configured. This allows the terminal device to trigger the retransmission enhancement scheme based on the remaining lifetime of the data packet according to the configured triggering time threshold and the first indication information, thereby improving the flexibility of the terminal device in executing the retransmission enhancement scheme and helping to improve data transmission performance.

[0038] Optionally, at least one trigger duration threshold includes a first trigger duration threshold, and the first information is first indication information configured by the network device, which is used to indicate whether to use a polling enhancement scheme or a deliberate retransmission scheme. Based on the first information and configuration information, triggering the first retransmission enhancement scheme according to the remaining lifetime of the data packet includes: when the first indication information indicates the use of a polling enhancement scheme, triggering the polling enhancement scheme when the remaining lifetime of the first data packet is less than or equal to the first trigger duration threshold, wherein the first data packet is a data packet that has been sent and whose reception status is unknown, and the remaining lifetime of the first data packet is determined based on the duration of a first timer; when the first indication information indicates the use of a deliberate retransmission scheme, triggering the deliberate retransmission scheme when the remaining lifetime of the first data packet is less than the first trigger duration threshold.

[0039] In this way, the terminal device can trigger a polling enhancement scheme or an autonomous retransmission scheme based on the remaining lifetime of the data packet according to the instructions from the network device, which improves the flexibility of the first device in executing the retransmission enhancement scheme and helps to optimize data transmission performance.

[0040] Optionally, at least one trigger duration threshold includes a second trigger duration threshold and a third trigger duration threshold, and the second trigger duration threshold is greater than the third trigger duration threshold. The first information is a first indication information configured by the network device, which is used to indicate whether to prioritize the use of the polling enhancement scheme or the autonomous retransmission scheme. Based on the first information and at least one trigger duration threshold, a first retransmission enhancement scheme is triggered based on the remaining lifetime of the data packet, including: when the first indication information indicates the use of a priority polling enhancement scheme, triggering a polling enhancement scheme when the remaining lifetime of the first data packet is less than or equal to a second trigger duration threshold; if no status report is received when the remaining lifetime of the first data packet is less than or equal to a third trigger duration threshold, triggering an autonomous retransmission scheme, wherein the first data packet is a data packet that has been sent and whose reception status is unknown; when the first indication information indicates the use of a priority autonomous retransmission scheme, triggering an autonomous retransmission scheme, or triggering both an autonomous retransmission scheme and a polling enhancement scheme, when the remaining lifetime of the first data packet is less than or equal to the second trigger duration threshold; if no status report is received when the remaining lifetime of the first data packet is less than or equal to the third trigger duration threshold, triggering either a polling enhancement scheme, or triggering both an autonomous retransmission scheme and a polling enhancement scheme.

[0041] In this way, the terminal device can trigger a joint retransmission enhancement scheme, such as a priority polling enhancement scheme or a priority autonomous retransmission scheme, based on the indication information from the network device. This improves the flexibility of the first device in executing the retransmission enhancement scheme and helps optimize data transmission performance. Moreover, during the execution of the joint retransmission enhancement scheme, the terminal device can also trigger the retransmission enhancement scheme based on the remaining lifetime of the data packet according to the duration threshold configured by the second device, further improving the flexibility of executing the retransmission enhancement scheme.

[0042] Optionally, at least one trigger duration threshold includes a fourth trigger duration threshold and / or a fifth trigger duration threshold. The fourth trigger duration threshold is the trigger duration threshold for a polling enhancement scheme, and the fifth trigger duration threshold is the trigger duration threshold for an autonomous retransmission scheme. The first information is first indication information configured by the network device, used to indicate whether to use the retransmission enhancement scheme. Based on the first information and at least one trigger duration threshold, triggering the first retransmission enhancement scheme based on the remaining lifetime of the data packet includes: if the first indication information indicates the use of the retransmission enhancement scheme, triggering the retransmission enhancement scheme corresponding to the trigger duration threshold based on the remaining lifetime of the data packet according to the trigger duration thresholds included in the at least one trigger duration threshold.

[0043] Optionally, based on the remaining lifetime of the data packet, a retransmission enhancement scheme corresponding to the trigger duration threshold is triggered according to the trigger duration threshold included in at least one trigger duration threshold, including: if at least one trigger duration threshold includes a fourth trigger duration threshold, then if the remaining lifetime of the first data packet is less than the fourth trigger duration threshold, a polling enhancement scheme is triggered, wherein the first data packet is a data packet that has been sent and whose reception status is unknown; if at least one trigger duration threshold includes a fifth trigger duration threshold, then if the remaining lifetime of the first data packet is less than or equal to the fifth trigger duration threshold, an autonomous retransmission scheme is triggered; if at least one trigger duration threshold includes both a fourth and a fifth trigger duration threshold, and the fourth trigger duration threshold is less than or equal to the fifth trigger duration threshold, a retransmission scheme is triggered; if at least one trigger duration threshold includes both a fourth and a fifth trigger duration threshold, and the fourth trigger duration threshold is less than or equal to the fifth trigger duration threshold, a retransmission scheme is triggered. If the threshold is greater than the fifth trigger duration threshold, then the polling enhancement scheme is triggered if the remaining lifetime of the first data packet is less than or equal to the fourth trigger duration threshold; if no status report is received when the remaining lifetime of the first data packet is less than or equal to the fifth trigger duration threshold, then the autonomous retransmission scheme is triggered; if at least one trigger duration threshold includes the fourth and fifth trigger duration thresholds, and the fourth trigger duration threshold is less than the fifth trigger duration threshold, then the autonomous retransmission scheme is triggered if the remaining lifetime of the first data packet is less than or equal to the fifth trigger duration threshold; if no status report is received when the remaining lifetime of the first data packet is less than or equal to the fourth trigger duration threshold, then the polling enhancement scheme is triggered.

[0044] In this way, the terminal device can be instructed to use which joint retransmission enhancement scheme by the first indication information and the configured trigger duration threshold. This expands the ways to instruct the terminal device to execute the joint retransmission enhancement scheme, further improves the flexibility of executing the retransmission enhancement scheme, and helps to optimize data transmission performance.

[0045] Optionally, at least one trigger duration threshold includes multiple trigger duration thresholds. The first information is first indication information configured by the network device, which indicates whether to use a polling enhancement scheme, a deliberate retransmission scheme, or a polling enhancement scheme or a deliberate retransmission scheme. Based on the first information and at least one trigger duration threshold, triggering the first retransmission enhancement scheme based on the remaining lifetime of the data packet includes: if the first indication information indicates the use of a polling enhancement scheme, then the polling enhancement scheme is triggered when the remaining lifetime of the first data packet is less than or equal to any one of the multiple trigger duration thresholds, where the first data packet is a sent data packet with an unknown reception status; if the first indication information indicates the use of a deliberate retransmission scheme, then the deliberate retransmission scheme is triggered when the remaining lifetime of the first data packet is less than or equal to any one of the multiple trigger duration thresholds; if the first indication information indicates the priority use of a polling enhancement scheme, then the polling enhancement scheme is triggered when the remaining lifetime of the first data packet is less than or equal to the sixth trigger duration threshold; if the remaining lifetime threshold of the first data packet is less than or equal to the seventh trigger duration threshold; if the first indication information indicates priority use of a polling enhancement scheme, then the polling enhancement scheme is triggered when the remaining lifetime of the first data packet is less than or equal to the sixth trigger duration threshold; if the remaining lifetime threshold of the first data packet is less than or equal to the seventh trigger duration threshold; if the remaining lifetime threshold of the first data packet is less than or equal to the seventh trigger duration threshold; if the first indication information indicates priority use of a polling enhancement scheme, then the polling enhancement scheme is triggered when the remaining lifetime ... first indication information indicates priority use of a polling enhancement scheme, then the polling enhancement scheme is triggered when the remaining lifetime of the If no status report is received by the specified duration threshold, the autonomous retransmission scheme is triggered. The seventh trigger duration threshold is the first trigger duration threshold after the sixth trigger duration threshold, ordered from largest to smallest among the multiple trigger duration thresholds. If the first indication information indicates that the autonomous retransmission scheme should be used first, then the autonomous retransmission scheme, or the autonomous retransmission scheme and the enhanced polling scheme, is triggered when the remaining lifetime of the first data packet is less than or equal to the eighth trigger duration threshold among the multiple trigger duration thresholds. If no status report is received by the specified duration threshold of the first data packet, which is less than or equal to the ninth trigger duration threshold, the enhanced polling scheme, or the autonomous retransmission scheme and the enhanced polling scheme, is triggered. The ninth trigger duration threshold is the first trigger duration threshold after the eighth trigger duration threshold, ordered from largest to smallest among the multiple trigger duration thresholds.

[0046] In this way, based on the first indication information, the terminal device can support both the selection of retransmission enhancement scheme and the joint enhancement scheme, which further improves the flexibility of implementing the retransmission enhancement scheme and helps to optimize data transmission performance.

[0047] Optionally, the polling enhancement scheme includes: triggering polling when transmitting the next data packet to be transmitted, or triggering polling when retransmitting the first data packet.

[0048] Optionally, triggering the autonomous retransmission scheme includes: retransmitting the first data packet.

[0049] Optionally, if the network device configures a first timer for the terminal device, the terminal device can start the first timer upon receiving the first data packet; and determine the remaining lifetime of the first data packet based on the duration of the first timer.

[0050] In this way, the remaining lifetime of data packets can be counted in a timely manner, so as to trigger the corresponding retransmission enhancement scheme based on the remaining lifetime of the data packets.

[0051] Optionally, upon receiving the first data packet, starting a first timer includes: if the first timer is configured in the RLC entity of the terminal device, starting the first timer when the RLC entity receives the first data packet sent by the upper layer; wherein the first timer is a new counter configured by the network device for the RLC entity; if the first timer is configured in the PDCP entity of the terminal device, starting the first timer when the PDCP entity receives the first data packet sent by the upper layer, or when sending the first data packet to the RLC entity; wherein the first timer is a drop timer in the PDCP entity or a new counter configured by the network device for the PDCP entity.

[0052] In this way, the first timer can be configured either at the RLC layer or the PDCP layer of the terminal device, which improves the flexibility of configuring the first timer.

[0053] Optionally, after executing the first retransmission enhancement scheme, if a second indication message is received from the network device, and the second indication message indicates that the retransmission enhancement scheme is not used, then the execution of the first retransmission enhancement scheme is stopped; and / or, if the number of executions or the execution duration of the target retransmission enhancement scheme exceeds a first threshold, then the execution of the target retransmission enhancement scheme is stopped. The target retransmission enhancement scheme is any retransmission enhancement scheme executed during the execution of the first retransmission enhancement scheme. The first threshold is a first duration threshold or a first number threshold, which is configured by the network device; and / or, if the PDB of the service data stream expires, then the execution of the first retransmission enhancement scheme in the corresponding RLC entity is stopped.

[0054] In this way, the retransmission enhancement scheme can be stopped according to different strategies, avoiding unnecessary retransmissions and saving system resources.

[0055] Optionally, the first information includes third indication information or content ratio information; wherein, the third indication information is used to indicate that the first data packet is a delay-critical data packet, and the first data packet is a data packet that has been sent but whose status is unknown; wherein, the content ratio information refers to the ratio between the minimum number of data packets required for the receiving end to successfully recover the data and the total number of data packets.

[0056] By implementing retransmission enhancement schemes based on latency-critical information or content ratio information, the flexibility of implementing retransmission enhancement schemes can be further improved, which helps to optimize data transmission performance.

[0057] Optionally, the first information includes third indication information. Based on the first information, a first retransmission enhancement scheme is executed, including: if the third indication information is obtained before the initial transmission of the first data packet, a polling enhancement scheme is triggered during the initial transmission of the first data packet; if the third indication information is obtained after the initial transmission of the first data packet, an autonomous retransmission scheme is executed for the first data packet.

[0058] By implementing different retransmission enhancement schemes based on the different transmission states of the delayed critical data packets, some unnecessary retransmissions can be reduced, thus lowering system consumption.

[0059] Optionally, after triggering the polling enhancement scheme during the initial transmission of the first data packet, the method further includes: if no status report is received when the remaining lifetime of the first data packet is less than or equal to the tenth trigger duration threshold, then an autonomous retransmission scheme is executed for the first data packet, where the tenth trigger duration is configured by the network device; if a third indication information is obtained after the initial transmission of the first data packet, then an autonomous retransmission scheme is executed for the first data packet, including: if a third indication information is obtained after the initial transmission of the first data packet, and no status report is received when the remaining lifetime of the first data packet is less than or equal to the tenth trigger duration threshold, then an autonomous retransmission scheme is executed for the first data packet.

[0060] By triggering polling upon initial transmission of the first data packet and then executing an autonomous retransmission scheme, the timeliness of retransmission can be further improved, effectively preventing data packet loss. Furthermore, by triggering autonomous retransmission based on the remaining lifetime of the data packet, the flexibility of executing autonomous retransmission can be further enhanced.

[0061] Optionally, the first information includes content ratio information. Based on the first information, a first retransmission enhancement scheme is executed, including: if the reception ratio of the first PDU set is less than the content ratio information, the first retransmission enhancement scheme is executed on a specific PDU in the first PDU set, where the reception ratio refers to the ratio between the number of PDUs that have been successfully received in the first PDU set and the total number of PDUs. If the reception ratio of the first PDU set is greater than or equal to the content ratio information, no retransmission or initial transmission is performed on other PDUs in the first PDU set.

[0062] By determining the content ratio information and the reception ratio of the first PDU set, and by not retransmitting or retransmitting other PDUs in the first PDU set when the reception ratio of the first PDU set is greater than or equal to the content ratio information, system resources can be saved and unnecessary data packets can be avoided. By implementing a retransmission enhancement scheme for specific PDUs in the first PDU set when the reception ratio is less than the content ratio information, the timeliness of successful transmission of the first PDU set can be improved, thereby enhancing the timeliness and reliability of data transmission.

[0063] Optionally, a first retransmission enhancement scheme is executed on a specific PDU in the first PDU set, including: when the remaining lifetime of the second PDU in the first PDU set is less than or equal to the eleventh trigger duration threshold, if all PDUs in the first PDU set have completed their initial transmission, an autonomous retransmission scheme is executed for the second PDU, which is a PDU that has completed its initial transmission and whose reception status is unknown; if there are PDUs in the first PDU set that have not undergone initial transmission, a polling enhancement scheme is triggered when transmitting the next PDU in the first PDU set that is to be transmitted.

[0064] By implementing different retransmission enhancement schemes based on the initial transmission completion status of the first PDU set, the flexibility of implementing retransmission enhancement schemes can be further improved, unnecessary retransmissions can be avoided, and system consumption can be saved.

[0065] Optionally, the terminal device can also acquire PDU set information. During PDU transmission, based on the PDU set information, it records the number of PDUs that have been successfully received in the first PDU set to determine the reception ratio of the first PDU set. The PDU set information is used to indicate individual PDUs belonging to the same PDU set.

[0066] Optionally, the content ratio information is obtained from the network device. The eleventh trigger duration threshold is configured by the network device.

[0067] Secondly, a retransmission enhancement method is provided. This method can be executed by a network device, or by a component configured in the network device (such as a circuit, chip, or chip system), or by a logic module or software capable of implementing all or part of the functions of the network device. This application does not limit this approach. The following description uses a network device as an example.

[0068] The method includes: sending a first indication information to a terminal device, the first indication information being used to indicate whether a retransmission enhancement scheme is to be used, and / or indicating the retransmission enhancement scheme to be used.

[0069] In this way, by sending the first indication information to the terminal device, it can be indicated whether the terminal device should execute the retransmission enhancement scheme or which retransmission enhancement scheme to execute, which improves the flexibility of the terminal device in executing the retransmission enhancement scheme and helps to improve data transmission performance.

[0070] Optionally, if the first indication information includes the retransmission enhancement scheme activation status, the first indication information also includes configuration information corresponding to the retransmission enhancement scheme activation status. The configuration information includes parameters related to the triggering conditions of the retransmission enhancement scheme activated by the retransmission enhancement scheme activation status indication.

[0071] In this way, by sending the first indication information to the terminal device, the triggering conditions for the retransmission enhancement scheme can be indicated to the terminal device, further improving the flexibility of the terminal device in executing the retransmission enhancement scheme.

[0072] Optionally, at least one trigger duration threshold and a first timer and / or timing parameters of the first timer are configured to the terminal device. The timing duration of the first timer is used to determine the remaining lifetime of the data packet, so that the terminal device triggers the retransmission enhancement scheme to be executed based on the remaining lifetime of the data packet according to the first indication information, at least one trigger duration threshold and the first timer.

[0073] By configuring at least one trigger duration threshold, as well as a timer and / or the timer's timing parameters, the terminal device can trigger the retransmission enhancement scheme to be executed based on the remaining lifetime of the data packet according to the first indication information and the configured trigger duration threshold, further improving the flexibility of the terminal device in executing the retransmission enhancement scheme.

[0074] Optionally, a first threshold is configured for the terminal device. The first threshold is either a first duration threshold or a first number threshold. The first duration threshold is used to indicate the maximum execution duration of the retransmission enhancement scheme by the terminal device, and the first number threshold is used to indicate the maximum number of times the retransmission enhancement scheme is executed by the terminal device.

[0075] By configuring duration or number of retransmission thresholds for terminal devices, the maximum execution time or number of retransmission enhancement schemes can be limited, thus avoiding excessive execution time or number of retransmissions and saving system power consumption.

[0076] Optionally, a second timer or a first counter is configured on the terminal device. The second timer is used to count the execution time of the retransmission enhancement scheme to be executed, and the first counter is used to count the number of times the retransmission enhancement scheme to be executed is executed.

[0077] By configuring a second timer or a first counter on the terminal device, it is convenient for the terminal device to count the execution time or number of times the retransmission enhancement scheme is executed.

[0078] Thirdly, a retransmission enhancement method is provided. This method can be executed by a network device, or by a component configured in the network device (such as a circuit, chip, or chip system), or by a logic module or software capable of implementing all or part of the functions of the network device. This application does not limit this approach. The following description uses a network device as an example.

[0079] The method includes: sending content ratio information to a terminal device so that the terminal device performs a retransmission enhancement scheme on the PDUs in the first PDU set based on the content ratio information, wherein the content ratio information refers to the ratio between the minimum number of data packets required for the receiving end to successfully recover the data and the total number of data packets.

[0080] By sending content ratio information to the terminal device, the terminal device can compare the reception ratio of the first PDU set with the content ratio information during data transmission. If the reception ratio of the first PDU set is greater than or equal to the content ratio information, other PDUs in the first PDU set will not be retransmitted or retransmitted, thus saving system resources and avoiding the transmission of unnecessary data packets. Furthermore, when the reception ratio of the first PDU set is less than the content ratio information, the terminal device can execute a retransmission enhancement scheme for specific PDUs in the first PDU set, improving the timeliness of successful transmission of the first PDU set, thereby enhancing the timeliness and reliability of data transmission.

[0081] Optionally, the method further includes: configuring at least one trigger duration threshold to the terminal device, so that the terminal device triggers a retransmission enhancement scheme based on the remaining lifetime of the PDUs in the first PDU set according to the content ratio information and at least one trigger duration threshold.

[0082] By configuring at least one trigger duration threshold to the terminal device, the terminal device can trigger the retransmission enhancement scheme to be executed based on the remaining lifetime of the data packet according to the configured trigger duration threshold, which further improves the flexibility of the terminal device in executing the retransmission enhancement scheme.

[0083] Optionally, the method further includes: configuring a first timer and / or timing parameters of the first timer to the terminal device, wherein the timing duration of the first timer is used to determine the remaining lifetime of the data packet.

[0084] By configuring a second timer or a first counter on the terminal device, it is convenient for the terminal device to count the execution time or number of times the retransmission enhancement scheme is executed.

[0085] Fourthly, a communication device is provided, including a processor. The processor is coupled to a memory and can be used to execute instructions or data in the memory to implement the methods in any of the possible implementations of the first to third aspects described above. Optionally, the communication device further includes a memory.

[0086] Fifthly, a computer program product is provided, the computer program product comprising: a computer program (also referred to as code or instructions), which, when run, causes a computer to perform a method in any possible implementation of any of the above aspects.

[0087] In a sixth aspect, a computer-readable storage medium is provided that stores a computer program (also referred to as code or instructions) that, when executed on a computer, causes the computer to perform the methods in any possible implementation of any of the above aspects.

[0088] In a seventh aspect, embodiments of this application provide a chip system including one or more processors for calling and executing instructions stored in memory, causing the methods in any of the above aspects or any possible implementations of the above aspects to be executed. The chip system may be composed of chips or may include chips and other discrete devices.

[0089] The chip system may include input circuits or interfaces for transmitting information or data, and output circuits or interfaces for receiving information or data.

[0090] Eighthly, a communication system is provided, including the aforementioned terminal device and network device. Optionally, the communication system may further include other devices that communicate with the terminal device and / or network device. Attached Figure Description

[0091] Figure 1 shows a schematic diagram of data transmission at each layer of the protocol stack;

[0092] Figure 2 illustrates the data packet processing flow of each protocol layer on the transmitting side user plane;

[0093] Figure 3 shows a schematic diagram of an RLC architecture;

[0094] Figure 4 shows a schematic diagram of an AM RLC entity model;

[0095] Figure 5 shows a schematic diagram of several formats of AMD PDU;

[0096] Figure 6 shows a schematic diagram of several formats of status PDU;

[0097] Figure 7 shows a schematic diagram of a communication system 100 applicable to an embodiment of this application;

[0098] Figure 8 shows a schematic flowchart of a retransmission enhancement method provided in an embodiment of this application;

[0099] Figure 9 shows a schematic diagram of a MAC CE format provided in an embodiment of this application;

[0100] Figure 10 shows a flowchart illustrating the first possible implementation of Scheme 1 in this application.

[0101] Figure 11 shows a flowchart illustrating a second possible implementation of Scheme 1 in this application.

[0102] Figure 12 shows a flowchart illustrating a third possible implementation of Scheme 1 in this application.

[0103] Figure 13 shows a schematic flowchart of the first possible implementation of Scheme 2 in the embodiments of this application;

[0104] Figure 14 shows a schematic flowchart of the first possible implementation of Scheme 2 in the embodiments of this application;

[0105] Figure 15 shows a schematic flowchart of a third possible implementation of Scheme 2 in the embodiments of this application;

[0106] Figure 16 shows another schematic flowchart of a third possible implementation of Scheme 2 in the embodiments of this application;

[0107] Figure 17 shows a schematic flowchart of one possible implementation of Scheme 5 in the embodiments of this application;

[0108] Figure 18 shows a schematic block diagram of a communication device provided in an embodiment of this application. Detailed Implementation

[0109] The technical solutions of this application embodiment can be applied to various communication systems, such as: Global System of Mobile communication (GSM) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD) system, Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system, future 5th Generation (5G) system, or New Radio (NR), etc.

[0110] In this application, the terminal device can refer to user equipment (UE), station, access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user device. The terminal device can also be a cellular phone, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, personal digital assistant (PDA), handheld device with wireless communication capabilities, computing device or other processing device connected to a wireless modem, large screen, in-vehicle device, wearable device, terminal device in a 5G network, or terminal device in a future evolved public land mobile network (PLMN), etc. This application does not limit the scope of the terminal device.

[0111] The network device in this application embodiment can be a device used for communication of terminal devices. For example, the network device is a radio access network (RAN) node (or device) that connects the terminal device to the wireless network, and can also be called a base station. For example, the network device can be an evolved NodeB (eNodeB), a transmission reception point (TRP), a next-generation NodeB (gNB) in a 5G mobile communication system, a base station in a future mobile communication system, or an access point (AP) in a WiFi system, a radio controller, relay station, access point, vehicle-mounted equipment, wearable device, or other network devices in future evolved communication systems, etc., in a cloud radio access network (CRAN) scenario.

[0112] In this embodiment, the terminal device or network device includes a hardware layer, an operating system layer running on top of the hardware layer, and an application layer running on top of the operating system layer. The hardware layer includes hardware such as a central processing unit (CPU), a memory management unit (MMU), and memory (also called main memory). The operating system can be any one or more computer operating systems that implement business processing through processes, such as Linux, Unix, Android, iOS, or Windows. The application layer includes applications such as browsers, address books, word processing software, and instant messaging software. Furthermore, this embodiment does not specifically limit the structure of the execution entity of the method provided in this embodiment, as long as it can communicate according to the method provided in this embodiment by running a program that records the code of the method provided in this embodiment.

[0113] Furthermore, various aspects or features of this application can be implemented as methods, apparatus, or articles of manufacture using standard programming and / or engineering techniques. The term "article of manufacture" as used herein encompasses a computer program accessible from any computer-readable device, carrier, or medium. For example, computer-readable media may include, but are not limited to: magnetic storage devices (e.g., hard disks, floppy disks, or magnetic tapes), optical discs (e.g., compact discs (CDs), digital versatile discs (DVDs), etc.), smart cards, and flash memory devices (e.g., erasable programmable read-only memory (EPROMs), cards, sticks, or key drives, etc.). Additionally, the various storage media described herein may represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing, and / or carrying instructions and / or data.

[0114] To facilitate understanding of the embodiments of this application, the relevant concepts involved in this application will first be explained.

[0115] 1. Protocol Layer Structure

[0116] Interoperable network devices and terminal devices have a specific protocol layer structure. For example, the control plane protocol layer structure, from top to bottom, can include the functions of protocol layers such as Radio Resource Control (RRC), Packet Data Convergence Protocol (PDCP), Radio Link Control (RLC), Media Access Control (MAC), and Physical (PHY). The user plane protocol layer structure, from top to bottom, can include the functions of protocol layers such as PDCP, RLC, MAC, and Physical. The Physical layer is located at the lowest layer (Layer 1), the MAC, RLC, and PDCP belong to the second layer (Layer 2), and RRC belongs to the third layer (Layer 3). In one implementation, a Service Data Adaptation Protocol (SDAP) layer can also be included above the PDCP layer.

[0117] The functions of these protocol layers can be implemented by a single node or by multiple nodes. For example, in one evolutionary architecture, a radio access network device may include a centralized unit (CU) and distributed units (DUs), with multiple DUs being centrally controlled by a single CU. CUs and DUs can be distinguished according to the protocol layers of the wireless network; for example, the functions of PDCP and higher protocol layers are located in the CU, while the functions of lower protocol layers, such as RLC and MAC layers, are located in the DU.

[0118] It should be understood that this protocol layer division is merely an example. It can also be applied to other protocol layers, such as the RLC layer, where the functions of the RLC layer and above are placed in the CU, and the functions of the protocol layers below the RLC layer are placed in the DU. Alternatively, it can be divided within a specific protocol layer, for example, placing some functions of the RLC layer and the functions of the protocol layers above the RLC layer in the CU, and placing the remaining functions of the RLC layer and the functions of the protocol layers below the RLC layer in the DU. Furthermore, it can be divided in other ways, such as by latency, placing functions whose processing time needs to meet latency requirements in the DU, and functions that do not need to meet this latency requirement in the CU.

[0119] When data is transmitted between network devices and terminal devices, taking uplink data transmission as an example, Figure 1 illustrates a schematic diagram of data transmission across the protocol stack layers. Data first reaches the PDCP layer of the terminal device, and after processing by the PDCP layer, it is transmitted to the RLC and MAC layers. After processing at the MAC layer, it is sent to the network device through the physical layer. When the network device receives data, the protocol layers it passes through in sequence are the physical layer, MAC layer, RLC layer, and PDCP layer. Data in each radio bearer needs to be processed by each layer. Each layer has corresponding functional entities to perform its respective function; for example, the PDCP layer corresponds to the PDCP entity, the RLC layer to the RLC entity, and the MAC layer to the MAC entity. Each radio bearer contains one PDCP entity and one or more RLC entities, each RLC entity corresponding to a logical channel. One MAC entity corresponds to multiple logical channels, and data in the logical channels can be multiplexed at the MAC layer, for example, multiplexed into the same data block, and finally sent out through the physical layer. The transmission process for downlink data is similar.

[0120] 2. Data packet

[0121] The user plane (UP) protocol stack of the 5th generation (5G) system includes, from top to bottom, the SDAP layer, PDCP layer, RLC layer, MAC layer, and PHY layer.

[0122] Figure 2 illustrates the data packet processing flow of each protocol layer on the user plane of the transmitting side. Referring to Figure 1, on the transmitting side, the data packet first arrives at the SDAP layer. The SDAP layer delivers the data packet to the corresponding PDCP entity of the DRB according to the mapping rules of quality of service (QoS) flow to data radio bearer (DRB) (each DRB corresponds to one PDCP entity). The PDCP layer performs compression, encryption, and other operations on the data packet before delivering it to the RLC layer. The RLC layer processes the data packet, such as segmenting or not segmenting, before delivering it to the MAC layer. The MAC layer assembles one or more data packets into a MAC protocol data unit (PDU) and delivers it to the PHY layer.

[0123] The data packets received by the SDAP layer are Internet Protocol (IP) packets, which are called SDAP Service Data Units (SDUs) at the SDAP layer. After processing these SDUs by adding headers and other methods to obtain SDAP Protocol Data Units (PDUs), the SDAP layer delivers the SDAP PDU to the PDCP entity. In other words, the data packets delivered by the SDAP layer to the PDCP entity are SDAP PDUs.

[0124] In the DPCP layer, the SDAP PDU is referred to as a PDCP SDU. After the PDCP layer performs processing such as adding a header to the PDCP SDU to obtain the PDCP PDU, it delivers the PDCP PDU to the RLC layer. That is, the data packet delivered by the PDCP layer to the RLC layer is a PDCP PDU.

[0125] In the RLC layer, the PDCP PDU is referred to as an RLC SDU. The RLC layer may or may not segment the RLC SDU. When the RLC SDU is segmented, each segment is called an RLC SDU segment. After obtaining the RLC PDU by adding headers and other related processing to the RLC SDU segments or RLC SDUs, the RLC PDU is delivered to the MAC layer. That is, the data packet delivered by the RLC layer to the MAC layer is an RLC PDU.

[0126] In the MAC layer, the RLC PDU is referred to as a MAC SDU. The MAC layer performs various processing on the MAC SDU, such as adding a MAC header, to obtain a MAC subPDU. One or more MAC subPDUs are then combined to form a MAC PDU, which is then delivered to the PHY layer. In other words, the data packets delivered by the MAC layer to the PHY layer are MAC PDUs.

[0127] The PHY layer modulates and encodes the MAC PDU to generate a transport block (TB), which is then sent out through air interface resources.

[0128] 3. RLC in acknowledged mode (AM)

[0129] The RLC layer sits above the MAC layer and is part of Layer 2 (L2), providing segmentation and retransmission services for user and control data. The RLC layer includes three transmission modes: transparent mode (TM), unacknowledged mode (UM), and acknowledged mode.

[0130] In transparent mode, RLC (TM RLC) does not process the SDUs passed into the RLC and transmits them directly.

[0131] In unacknowledged mode, RLC (UM RLC) adds the necessary control protocol overhead (such as sequence number, checksum, etc.) to the higher-layer PDU before transmission. Since no retransmission protocol is used, the sender does not wait for the receiver's acknowledgment message.

[0132] Acknowledgment-mode RLC (AM RLC) introduces an ACK / NACK mechanism, requiring the receiver to acknowledge (ACK) or deny (NACK) received data. The sender can retransmit unacknowledged data packets based on the received ACK / NACK information. Compared to TM RLC and AM RLC, AM RLC ensures reliable data transmission to peer entities and corrects potential errors during transmission through retransmission mechanisms, providing reliable data transmission guarantees.

[0133] For example, AM RLC has the following functions: it transmits data after adding the necessary control protocol overhead to the higher-layer PDU and ensures delivery to the peer entity; it has ARQ (Automatic Repeat Request) capability, which notifies the sending RLC to retransmit the PDU if the RLC receives an incorrect RLC PDU; the RLC PDU contains sequence number information, supporting ordered / out-of-order delivery of data to higher layers.

[0134] 4. AM RLC entity

[0135] An AM RLC entity consists of a transmitter and a receiver. The transmitter of an AM RLC entity receives RLC SDUs from the upper layer and sends RLC PDUs to its peer AM RLC entity through the lower layer. The receiver of an AM RLC entity delivers RLC SDUs to the upper layer and receives RLC PDUs from its peer AM RLC entity through the lower layer.

[0136] Figure 3 illustrates a schematic diagram of an RLC architecture. Referring to Figure 3, for transparent mode, unacknowledged mode, and acknowledged mode, each RLC entity includes a sender and a receiver. In transparent mode, the sender of the TM RLC entity can send the incoming SDU directly to the receiver of the peer TM RLC entity without performing any processing. In unacknowledged mode, the sender of the UM RLC entity can add necessary control protocol overhead (such as sequence numbers, checksums, etc.) to the incoming SDU before sending it to the receiver of the peer TM RLC entity.

[0137] In acknowledgment mode, the AM RLC entity can handle data transmission, reception, acknowledgment, and retransmission. Within the AM RLC entity, each RLC SDU is used to construct an RLC PDU without waiting for transmission opportunity notification from the lower layer (i.e., the MAC layer). The AM RLC entity can segment an RLC SDU based on notification from the lower layer and transmit it through two or more RLC PDUs. An RLC PDU is only submitted to the lower layer when a transmission opportunity is indicated. An RLC PDU contains either a complete RLC SDU or an RLC SDU segment.

[0138] AM RLC entities can submit / receive RLC PDUs through the following logical channels: dedicated control channel (DCCH), dedicated traffic channel (DTCH), and shared traffic channels (STCH).

[0139] Next, the functions of the AM RLC entity will be explained from the perspectives of the transmitting and receiving ends of the AM RLC entity.

[0140] 1) The sending end of the AM RLC entity.

[0141] The transmitting side of an AM RLC entity generates an AMD PDU for each RLC SDU. When notified by the lower layer of a transmission opportunity, the transmitting RLC entity can segment the RLC SDU as needed, ensuring that the total size of the corresponding RLC PDU, after updating the RLC header, is within the range of the lower layer's RLC PDU size. The transmitting end of the AM RLC entity supports retransmission of RLC SDUs or RLC SDU segments. This retransmission refers to automatic retransmission, i.e., NACK-based retransmission. When the transmitting end of the AM RLC entity forms an RLC PDU from an RLC SDU or RLC SDU segment, it can include the relevant RLC header in the RLC PDU.

[0142] 2) The receiver of the AM RLC entity.

[0143] When the receiver of an AM RLC entity receives an RLC PDU, it can detect whether a duplicate RLC PDU has been received and discard the duplicate. The receiver of an AM RLC entity can detect lost RLC PDUs from lower layers and request its peer AM RLC entity to retransmit them. The receiver of an AM RLC entity can reassemble the RLC SDU from the received RLC PDU and deliver it to the upper layer as soon as the RLC SDU becomes available.

[0144] Figure 4 shows a schematic diagram of an AM RLC entity model. Referring to Figure 4, the AM RLC entity has the following functions: 1. Generating an RLC header and storing it in the transmit buffer. When data needs to be transmitted, such as after receiving an SDU from the upper layer, the AM RLC entity first generates an RLC header, which contains necessary control information (such as sequence number, segmentation information, etc.). After generating the RLC header, the data, along with the RLC header, is stored in the transmit buffer, waiting to be sent to the lower layer (such as the MAC layer). 2. Segmenting and modifying the RLC header. When the SDU to be transmitted is large and cannot be directly transmitted to the lower layer, the AM RLC entity can segment it. Each segmented SDU segment will have an RLC header appended, and certain fields in the RLC header (such as segment offset) will be modified accordingly based on the segmentation status. 3. Adding an RLC header. Before data transmission, the AM RLC entity adds an RLC header before each data segment (SDU segment) to ensure that the data can be correctly identified and processed during transmission. 4. Retransmission buffer. The AM RLC entity maintains a retransmission buffer to store copies of data awaiting acknowledgment after transmission. If the receiver fails to send an ACK within a certain time or sends a NACK, the RLC layer retrieves the data from the retransmission buffer and retransmits it. 6. RLC Control. RLC control involves various control mechanisms within the RLC layer, such as status reporting, data retransmission, and the ARQ (Automatic Repeat Request) process. These control mechanisms ensure reliable data transmission and error correction. 7. Receiving Buffer. The AM RLC entity maintains a receive buffer. The receive buffer stores data received from the lower layer; for example, it temporarily stores received RLC PDUs until they are correctly reassembled and passed to the upper layer. 8. RLC Header Removal. During data reassembly, the RLC layer removes the RLC header from each data segment to reconstruct the original SDU. 9. SDU Reassembly. The data segments after RLC header removal are reassembled to reconstruct the original SDU.

[0145] 5. RLC PDU

[0146] A PDU is the basic unit used for data exchange in a communication protocol. A PDU in the RLC layer is called an RLC PDU.

[0147] In AM RLC, RLC PDUs can include two types: RLC data PDUs and RLC control PDUs. RLC data PDUs include AMD PDUs, and RLC control PDUs include status reporting PDUs.

[0148] 1) AMD PDU.

[0149] An AMD PDU is a data PDU used by the RLC layer under AM for data transmission. An AMD PDU consists of a data field and an AMD PDU header. The data field carries the data content of the upper-layer PDU (i.e., RLC SDU), while the AMD PDU header contains multiple fields required for controlling and managing data transmission.

[0150] The AMD PDU header may include fields such as Data / Control (D / C), Polling (P), Segmentation Information (SI), and Serial Number (SN), and may also include an optional SO field. Please refer to Figure 5, which illustrates several formats of the AMD PDU.

[0151] The D / C field is used to indicate whether an RLC PDU is an RLC data PDU or an RLC control PDU. For example, the values ​​and meanings of the D / C field are shown in Table 1 below. When D / C = 0, it indicates that the RLC PDU is an RLC data PDU. When D / C = 1, it indicates that the RLC PDU is an RLC control PDU.

[0152] The P (Poll) field is used to indicate whether the sender of an AM RLC entity requests a status report from its peer AM RLC entity. For example, the values ​​and meanings of the P field are shown in Table 2 below. When P = 0, it indicates that a status report from its peer AM RLC entity is requested. When P = 1, it indicates that a status report from its corresponding entity is not requested.

[0153] The SI field is used to indicate whether the RLC PDU contains a complete RLC SDU or the first, middle, or last segment of a segmented RLC SDU. For example, the length of the SI field can be configured to 2 bits. When the SI field is 00, it indicates that the data field contains all the bytes of the RLC SDU; when the SI field is 01, the data field contains the first segment of the RLC SDU; when the SI field is 10, the data field contains the last segment of the RLC SDU; and when the SI field is 11, the data field contains a segment that is neither the first nor the last.

[0154] The Serial Number (SN) field is used to indicate the order of RLC SDUs. In AM mode, the SN is incremented by 1 for each RLC SDU. The length of the SN field can be configured to be 12 bits or 18 bits.

[0155] The SO field is used to indicate which byte position in the original RLC SDU the RLC SDU segment begins with. For example, the AMD PDU header includes the SO field only if the data field consists of an RLC SDU segment that is not the first segment.

[0156] 2) Status PDU.

[0157] The status PDU is a control PDU used by the RLC layer under AM (Advanced Management Layer). It is used by the receiver to notify the sender of received data PDUs and to acknowledge lost data PDUs. The status PDU consists of a data field and an RLC control header. Please refer to Figure 6, which illustrates several formats of the status PDU.

[0158] The RLC control header contains some basic information about the control PDU. The RLC control header may include fields such as D / C, Control PDU Type (CPT), and Acknowledgment Sequence Number (ACK_SN).

[0159] The D / C field is used to indicate whether an RLC PDU is a data PDU or a control PDU. In a status PDU, this field should be set to a valid value (such as 0) to indicate that it is a control PDU.

[0160] The CPT field is used to indicate the type of RLC control PDU. In a status PDU, this bit should be set to a valid value (such as 000) to indicate that it is a status PDU.

[0161] The ACK_SN field is used to indicate the sequence number of the next SDU that has not been received and has not been reported lost. After receiving the status PDU, the sending end can assume that all SDUs before SN=ACK_SN have been received or are considered lost by the receiving end.

[0162] The data fields may include an optional NACK_SN field, which indicates the sequence number of a lost RLC SDU or SDU segment that the receiver has acknowledged. The NACK_SN field has the same length as the SN field in the AMD PDU, typically 12 bits or 18 bits.

[0163] The data fields may also include optional E2, E3, SOstart, and SOend, which are used in conjunction with NACK_SN to provide more detailed loss information.

[0164] 6. PDU set

[0165] A PDUset refers to a collection of one or more PDUs that carry a payload, such as a frame or video slice, generated at the application level. In other words, all the PDUs in a PDUset correspond to a single frame or video slice at the application layer.

[0166] 7. PDU set importance (PSI)

[0167] The PSI field is used to distinguish the relative importance of different PDU sets within the same multimedia session. This information may help the radio access network (RAN) discard PDUs when necessary. The PSI field is a numerical representation; the lower the value, the higher the importance of the PDU set; conversely, the higher the value, the lower the importance. The most important PDU set is represented by 1, while the least important PDU set is represented by 15 or other higher values. When the real-time transport protocol (RTP) sender cannot determine the importance of a PDU set, this field is typically set to 0.

[0168] Generally, when the RAN needs to drop packets (e.g., in congestion situations), it's best to selectively drop less important data rather than randomly dropping packets. If the dropped packets are critical to the media stream, the QoE can drop significantly. For this reason, a PSI field is used to mark PDUsets with different importance levels. The RAN can then use the PSI field to drop PDUsets. In congestion situations, PDUsets with higher PSI values ​​are more likely to be dropped.

[0169] 8. Packet delay budget (PDB)

[0170] PDB (Packet Delay Limit) is an important parameter used in communication networks to define the upper limit of packet latency. PDB defines the upper limit of latency between terminal devices and specific network nodes (such as user plane functions (UPFs)). PDB ensures that the latency of data packets during transmission does not exceed a predetermined threshold, thus meeting the data transmission latency requirements of various services.

[0171] 9. PDCP Discard Timer

[0172] The drop timer is used to maintain a threshold for the time packets must wait to be sent. The PDCP drop timer is a drop timer configured in the PDCP layer. When a packet's waiting time in the transmission buffer exceeds the value set by this timer, the PDCP layer will abandon further waiting and drop the packet. This mechanism aims to prevent increased transmission latency or wasted resources due to excessively long waiting times.

[0173] In the PDCP layer, the PDCP drop timer is configured for each DRB. This means that an independent drop timer value can be set for each DRB to optimize data transmission performance based on specific service requirements and network environment. The timer duration is configured by higher layers. In the PDCP layer, a new drop timer is started whenever an SDU is received from a higher layer.

[0174] 10. Delay critical data packets

[0175] In wireless communication, latency typically refers to the time required for a data packet to travel from the sender to the receiver. Latency-critical data packets are those containing service data with high real-time requirements.

[0176] Delayed critical packets can be delayed critical PDCP SDUs. If no PDU set discard timer is configured, a delayed critical PDCP SDU is a PDCP SDU whose remaining time is less than a remaining time threshold when the discard timer expires. If a PDU set discard timer is configured, a PDCP SDU is a PDCP SDU in a PDU set whose remaining time is less than a remaining time threshold when the discard timer expires.

[0177] The remaining time can also be referred to as the remaining survival duration or remaining survival time.

[0178] 11. Extended Reality (XR)

[0179] XR integrates multiple technologies such as Virtual Reality (VR) and Augmented Reality (AR). By utilizing computer graphics, perception technology, and human-computer interaction technology, XR merges virtual information with real-world scenes, enabling users to interact with the virtual world in real time.

[0180] Applications of XR services include, but are not limited to, gaming and entertainment, live video streaming, smart manufacturing, education and training, and healthcare. XR service data packets primarily consist of video / images and interactive commands, requiring networks to offer high throughput, low latency, and high reliability. In other words, XR service data packets have a short packet delay budget (PDB), necessitating data transmission within a short timeframe.

[0181] Next, the application scenarios involved in the embodiments of this application will be described in detail.

[0182] Currently, the retransmission mechanism introduced by the AM RLC layer is the Automatic Repeat Request (ARQ) mechanism, which can include retransmission based on status reports and polling.

[0183] Status report-based retransmission refers to a process where, during data transmission, the receiving end sends a status report to the sending end based on the status of the received data. The sending end then uses the information in the status report to determine whether data retransmission is necessary. If the receiving end fails to receive certain data, it will indicate this in the status report, and the sending end will retransmit accordingly.

[0184] For example, under a status report-based retransmission mechanism, the receiver of an AM RLC entity can send a status PDU to its peer AM RLC entity to provide acknowledgment and / or negative acknowledgment of an RLC SDU (or a portion thereof). When the transmitter of an AM RLC entity receives a negative acknowledgment of an RLC SDU or RLC SDU segment sent via a status PDU by its peer AM RLC, the transmitter of the AM RLC entity can retransmit the RLC SDU or RLC SDU segment that received the negative acknowledgment.

[0185] Polling is a query mechanism in communication protocols that allows the sender to periodically query the receiver's status or data reception progress. Through polling, the sender can promptly understand the receiver's status and take appropriate action.

[0186] For example, the sender of an AM RLC entity can poll its peer AM RLC entity, such as by sending a polling signal (e.g., carrying P=1 in the AMD PDU) to trigger a status report from the peer AM RLC entity. Polling trigger conditions may include: the number of PDUs or bytes sent reaching a certain threshold, the send buffer or retransmission buffer being empty, or timer timeouts being disabled.

[0187] However, current retransmission mechanisms have certain limitations in ensuring the reliability of data transmission. For example, in business scenarios requiring low latency, such as extended reality (XR), current retransmission mechanisms may not be able to retransmit data packets in a timely manner, thus failing to effectively limit data packet loss and potentially leading to unsuccessful transmission of business data, affecting the reliability and performance of data transmission.

[0188] For example, because XR service data packets have short PDBs, traditional retransmission mechanisms may fail to receive an ACK for the XR service data packet by the time its delay budget expires. This would result in the XR service data packet being discarded, causing the service data to fail to transmit successfully. In other words, current retransmission mechanisms may not be able to guarantee the reliability and effectiveness of data transmission for services with short PDBs, such as XR services.

[0189] In view of this, embodiments of this application provide a retransmission enhancement method, which can execute a first retransmission enhancement scheme based on first information. By executing the first retransmission enhancement scheme, the retransmission mechanism can be enhanced, thereby improving the timeliness of retransmitting data packets that have not been successfully received, effectively limiting data packet loss, and improving the data transmission success rate. Moreover, by selecting to execute the first retransmission enhancement scheme based on the first information, the flexibility of executing the retransmission enhancement scheme can also be improved. Thus, data transmission performance can be optimized, which is particularly helpful in ensuring the reliability and effectiveness of data transmission for services with short PDBs, such as XR types.

[0190] To facilitate understanding of the retransmission enhancement method provided in the embodiments of this application, the communication system applicable to the embodiments of this application will be briefly introduced first with reference to FIG7.

[0191] Figure 7 illustrates a schematic diagram of a communication system 100 applicable to an embodiment of this application. As shown in Figure 7, the mobile communication system 100 may include at least one wireless access network device 110 and at least one terminal device (terminal devices 120, 130, 140, 150, and 160 shown in Figure 7). The terminal devices are wirelessly connected to the wireless access network device, which may be the aforementioned network device. At least one terminal device may send uplink data or information to the wireless access network device, and the wireless access network device 110 may also send downlink data or information to at least one terminal device. Furthermore, multiple terminal devices may also form a communication system. For example, terminal devices 140, 150, and 160 may form a communication system, where terminal device 140 may send downlink data or information to terminal devices 150 and 160, and terminal devices 150 and 160 may send uplink data or information to terminal device 140.

[0192] It should be understood that Figure 7 is merely a schematic diagram, and the communication system may also include other network devices and / or terminal devices (not shown in Figure 7). The embodiments of this application do not limit the number of radio access network devices and terminal devices included in the mobile communication system. In the mobile communication system 100, the radio access network device 110 can be the aforementioned network device. Furthermore, the communication between the network device and the terminal device follows a certain protocol layer structure. For example, the protocol layer architecture shown in Figure 1. The network device may include CU and DU, which can be configured separately or centrally. The embodiments of this application do not impose limitations here.

[0193] The retransmission enhancement method provided in this application will be described in detail below with reference to Figure 8. Figure 8 shows a schematic flowchart of a retransmission enhancement method provided in an embodiment of this application. This method can be applied to the scenario shown in Figure 7, for example, in a scenario of transmitting XR-type service data. The embodiments of this application are not limited herein.

[0194] It should be understood that in the following description, the methods of each embodiment are explained using the first device, or the first device and the second device, as examples of the execution subjects of the execution methods in each embodiment. The first device can be the access network device described above, and the second device can be the terminal device described above. If the access network device adopts a CU and DU separate configuration mode, the first device described above can be the DU. As an example and not a limitation, the execution subject of the execution method can also be a chip applied in the first device or the second device.

[0195] As shown in Figure 8, the method illustrated in Figure 8 may include steps S810 to S820. The various steps of this method are described in detail below with reference to Figure 8. The method includes:

[0196] S810, the first device determines the first information.

[0197] The first information can be either a first instruction sent by the second device or a judgment information of the terminal device itself.

[0198] In one embodiment, the first indication information may be used to indicate whether a retransmission enhancement scheme is used, and / or, the retransmission enhancement scheme that needs to be used.

[0199] In one embodiment, when the first information is the terminal device's own judgment information, the first information may include information used to assist the first device in determining whether to execute a retransmission enhancement scheme, and / or to assist in determining which retransmission enhancement scheme to execute.

[0200] For example, the first information may include third indication information or content ratio information, etc. The third indication information is used to indicate the delay of critical data packets. The content ratio information refers to the ratio between the minimum number of data packets required for the receiving end to successfully recover the data and the total number of data packets of the data. It should be understood that the first information may also include other information used to assist in the judgment, and this application embodiment does not limit this.

[0201] In one embodiment, the first device may determine the first information in one of the following two ways:

[0202] 1) The first device receives the first instruction information sent by the second device.

[0203] 2) The first device acquires information to assist in determining whether to execute a retransmission enhancement scheme and / or to assist in determining which retransmission enhancement scheme to execute.

[0204] In one embodiment, the second device can send a first indication message to the first device based on data reception status or congestion status. For example, different functions of the first indication message can be sent to the first device based on different data reception status or congestion status.

[0205] In one implementation, the first indication information is used to indicate whether a retransmission enhancement scheme is used. For example, the first indication information includes a retransmission enhancement scheme activation state or a retransmission enhancement scheme deactivation state. The retransmission enhancement scheme activation state indicates that the retransmission enhancement scheme is activated. The retransmission enhancement scheme deactivation state indicates that the retransmission enhancement scheme is deactivated, for example, deactivating an already activated retransmission enhancement scheme.

[0206] In another implementation, the first indication information is used to indicate whether a retransmission enhancement scheme is used, and to indicate the retransmission enhancement scheme to be used among multiple retransmission enhancement schemes. For example, the first indication information includes a retransmission enhancement scheme activation state or a retransmission enhancement scheme deactivation state. The retransmission enhancement scheme activation state can include the activation state of any one of the multiple retransmission enhancement schemes.

[0207] In one embodiment, the multiple retransmission enhancement schemes may include at least two of the following: a polling enhancement scheme, a deliberate retransmission scheme, a priority polling enhancement scheme, and a priority deliberate retransmission scheme. It should be understood that other retransmission enhancement schemes, such as a status reporting enhancement scheme, may also be included among the multiple retransmission enhancement schemes; however, this application embodiment does not limit this.

[0208] In this embodiment, multiple retransmission enhancement schemes can coexist. The second device can indicate to the first device which retransmission enhancement scheme to execute via the first indication information, i.e., indicating which of the multiple retransmission enhancement schemes the first device needs to execute. This improves the flexibility of executing retransmission enhancement schemes and optimizes data transmission performance.

[0209] Among them, the polling enhancement scheme and the autonomous retransmission scheme are two single retransmission enhancement schemes.

[0210] Polling enhancement schemes refer to strengthening the polling mechanism. For example, additional triggering conditions can be added beyond the existing ones to increase the polling frequency. This helps to obtain the receiver's status report in a timely manner, enabling retransmission based on the status report and improving the timeliness of data packet retransmission and the success rate of data packet transmission.

[0211] The autonomous retransmission scheme refers to stateless retransmission, meaning that data packets are retransmitted even without a NACK received, thus increasing the retransmission trigger frequency. This helps to ensure timely retransmission of data packets, avoiding situations where data packets are dropped because the packet delay budget may have been reached after a NACK is received, thereby improving the timeliness of retransmission and the success rate of data packet transmission.

[0212] Among them, the priority polling enhancement scheme and the priority autonomous retransmission scheme are two joint retransmission enhancement schemes. The joint retransmission enhancement scheme means that the polling enhancement scheme and the autonomous retransmission scheme can be executed together when the retransmission enhancement scheme is implemented.

[0213] It should be noted that when jointly executing the polling enhancement scheme and the autonomous retransmission scheme, one of the two polling enhancement schemes can be executed first, and then the other can be triggered. Alternatively, both retransmission enhancement schemes can be executed simultaneously, for example, the other retransmission enhancement scheme can be triggered while one retransmission enhancement scheme is being executed. This application does not limit the method of joint execution.

[0214] It should also be noted that the embodiments of this application only illustrate two retransmission enhancement schemes: the joint execution of the polling enhancement scheme and the autonomous retransmission scheme. In other possible implementations, other retransmission enhancement schemes or even more retransmission enhancement schemes may be executed in combination. The embodiments of this application do not limit this.

[0215] In this embodiment of the application, by providing a jointly executed retransmission enhancement scheme, the timeliness of data packet retransmission and the data transmission success rate can be further improved during the data transmission process.

[0216] As an example, the priority polling enhancement scheme means that the polling enhancement scheme is executed first, and the autonomous retransmission scheme is executed if no status report is received when the triggering conditions of the autonomous retransmission scheme are met. That is, after the priority polling enhancement scheme is triggered, the polling enhancement scheme can be executed first, and then the autonomous retransmission scheme can be triggered when the corresponding conditions are met, so as to achieve the joint execution of polling enhancement and autonomous retransmission.

[0217] As an example, the priority autonomous retransmission scheme means that the autonomous retransmission scheme is executed first, and the polling enhancement scheme is triggered during the execution of the autonomous retransmission scheme. That is, after the priority autonomous retransmission scheme is triggered, both the autonomous retransmission scheme and the polling enhancement scheme can be triggered simultaneously. For example, when retransmitting data packets based on the autonomous retransmission scheme, polling indication information can be carried in the data packets to trigger polling.

[0218] As another example, the priority autonomous retransmission scheme means that the autonomous retransmission scheme is executed first, and the polling enhancement scheme is executed only if no status report is received when the triggering conditions of the polling enhancement scheme are met. That is, after the priority autonomous retransmission scheme is triggered, the autonomous retransmission scheme can be executed first, and then the polling enhancement scheme can be triggered when the corresponding conditions are met, so as to achieve the joint execution of autonomous retransmission and polling enhancement.

[0219] It should be noted that the granularity of the first indication information can be, from largest to smallest, the first device, QoS flow, DRB, RLC, or PDU. The indication granularity refers to the data range that the first indication information targets, that is, the data range for which the retransmission enhancement scheme is executed.

[0220] For example, when the indication granularity is the first device, the data range is all data packets associated with the first device. That is, the retransmission enhancement scheme is executed according to the indication of the first indication information for all data packets associated with the first device. Here, the data packets associated with the first device refer to all data packets under the QoS flow transmitted by the first device.

[0221] For example, when the indication granularity is QoS flow, the data range is all data packets associated with a QoS flow. That is, for all data packets associated with a specific QoS flow, the retransmission enhancement scheme is executed according to the indication of the first indication information. Here, all data packets associated with a QoS flow refer to data packets under all DRBs mapped by that QoS flow.

[0222] For example, when the indication granularity is DRB, the data range is all data packets associated with a DRB. That is, for all data packets associated with a specific DRB, the retransmission enhancement scheme is executed according to the first indication information. Here, all data packets associated with a DRB refer to data packets under all RLC entities contained in that DRB.

[0223] For example, when the indication granularity is RLC, the data range is all data packets associated with a specific RLC. That is, for all data packets associated with a specific RLC, the retransmission enhancement scheme is executed according to the indication of the first indication information. Here, all data packets associated with a specific RLC refer to the data packets transmitted by that RLC.

[0224] For example, when the indication granularity is PDU, the data range is one PDU, meaning that a retransmission enhancement scheme is executed for a specific PDU being transmitted according to the indication of the first indication information. For instance, a retransmission enhancement scheme is executed for a specific PDU being transmitted in some or all RLC entities according to the first indication information.

[0225] It should be noted that the granularity of the first indication information can be pre-configured by the second device. For example, it can be pre-defined by the second device at the PDCP layer or RLC layer. This application embodiment does not limit the configuration method of the granularity of the first indication information.

[0226] In one embodiment, the type of the first indication information may be an RRC message, a MAC control element (CE), or downlink control information (DCI), etc. The embodiments of this application do not limit the type of the first indication information.

[0227] S820, the first device executes the first retransmission enhancement scheme based on the first information.

[0228] It should be noted that the first retransmission enhancement scheme can be a pre-configured fixed retransmission enhancement scheme or one of multiple retransmission enhancement schemes.

[0229] In one embodiment, after determining the first information, the first device can determine whether to execute a retransmission enhancement scheme based on the first information, and if it is determined that a retransmission enhancement scheme needs to be executed, execute the pre-configured retransmission enhancement scheme.

[0230] In another embodiment, after determining the first information, the first device can first determine whether to execute a retransmission enhancement scheme based on the first information, and if it is determined that a retransmission enhancement scheme needs to be executed, determine the first retransmission enhancement scheme to be executed, that is, determine which retransmission enhancement scheme needs to be executed, and then execute the first retransmission enhancement scheme.

[0231] It should be noted that, in the embodiments of this application, for any retransmission enhancement scheme in the first retransmission enhancement scheme, the specific implementation form of the retransmission enhancement scheme is not limited, such as the triggering condition of the retransmission enhancement scheme is not limited. Alternatively, the specific implementation form of the retransmission enhancement scheme can be limited, such as limiting the retransmission enhancement scheme to be triggered based on the remaining lifetime of the data packet.

[0232] It should also be noted that, in the embodiments of this application, when the first retransmission enhancement scheme is one of multiple retransmission enhancement schemes, the first retransmission enhancement scheme can be a single retransmission enhancement scheme, such as one of multiple single retransmission enhancement schemes, or it can be a joint retransmission enhancement scheme, such as one of multiple joint retransmission enhancement schemes. The embodiments of this application do not limit this.

[0233] It should also be noted that after the first retransmission enhancement scheme is executed, any retransmission enhancement scheme executed during the execution of the first retransmission enhancement scheme can be stopped when the stopping condition is met.

[0234] As an example, the first device may stop executing the retransmission enhancement scheme upon receiving a second indication message from the second device, the second indication message indicating that the retransmission enhancement scheme is not used. And / or, the first device may stop executing the retransmission enhancement scheme when the number of executions or the execution duration of the retransmission enhancement scheme exceeds a first threshold, the first threshold being a first duration threshold or a first number threshold. And / or, the first device may stop executing the retransmission enhancement scheme in the corresponding RLC entity when the PDB of the service data stream expires. It should be understood that the retransmission enhancement scheme may also be stopped when other stopping conditions are met, and this embodiment of the application does not limit this.

[0235] It should be noted that the retransmission enhancement method provided in this application embodiment can be applied to the RLC layer of the first device, for example, to the RLC entity of the first device (such as an AM RLC entity). For example, the first device can execute a first retransmission enhancement scheme in the corresponding RLC entity according to the first information, that is, execute the first retransmission enhancement scheme through the corresponding RLC entity to enhance the retransmission of the RLC PDU transmitted in the RLC entity. For example, the first retransmission enhancement scheme can be executed through the corresponding RLC entity indicated by the indication granularity of the first indication information.

[0236] To facilitate understanding of this application, the retransmission enhancement method provided in the embodiments of this application will be described in detail below, taking the first information as the first indication information sent by the second device as an example.

[0237] It should be noted that executing the first retransmission enhancement scheme based on the first indication information of the second device can include the following three implementation schemes: Scheme 1: Triggering a single retransmission enhancement scheme based on the first indication information of the second device. Scheme 2: Triggering a combined retransmission enhancement scheme based on the first indication information of the second device. Scheme 3: Supporting both triggering a single retransmission enhancement scheme and triggering a combined retransmission enhancement scheme based on the first indication information of the second device.

[0238] Next, these three options will be explained in detail.

[0239] Option 1: Trigger a single retransmission enhancement scheme based on the first indication information from the second device.

[0240] In Scheme 1, the first indication information can indicate whether to use the retransmission enhancement scheme, and when indicating the use of the retransmission enhancement scheme, indicate which one to use: the polling enhancement scheme or the autonomous retransmission scheme.

[0241] After receiving the first instruction information from the second device, if the first instruction information indicates that the polling enhancement scheme should be used, then the polling enhancement scheme should be executed; if the first instruction information indicates that the autonomous retransmission scheme should be used, then the autonomous retransmission scheme should be executed; if the first instruction information indicates that the retransmission enhancement scheme should not be used, then the retransmission enhancement scheme should not be executed, for example, the already activated retransmission enhancement scheme should be stopped.

[0242] In one embodiment, the first indication information may include the activation status of the polling enhancement scheme, the activation status of the autonomous retransmission scheme, or the deactivation status of the retransmission enhancement scheme.

[0243] In one embodiment, the granularity of the first indication information can be terminal device, QoS flow, DRB, RLC or PDU, etc., and this application embodiment does not limit this.

[0244] In one embodiment, the information type of the first indication information may be an RRC message, a MAC control element (CE), or downlink control information (DCI), etc. It should be understood that the information type of the first indication information may also be other types, and this application embodiment does not limit this.

[0245] Next, taking MAC CE as an example as the first instruction information, we will explain one possible format of MAC CE.

[0246] As an example, a MAC CE can include a MAC CE header and data fields.

[0247] The MAC CE header may include a first field. This first field indicates that the MAC CE is first indication information, i.e., retransmission enhancement scheme indication information. For example, the first field may be LCID or eLCID. Please refer to Figure 9, which is a schematic diagram of first indication information of a MAC CE type provided in an embodiment of this application. As shown in Figure 9, the MAC CE header includes LCID and eLCID fields, where LCID or eLCID is used to indicate that the MAC CE is first indication information.

[0248] The MAC CE data fields may include a second field. This second field indicates whether a retransmission enhancement scheme is used, and which scheme—polling or autonomous retransmission—is used. For example, the second field indicates the retransmission enhancement scheme status, which may include polling activation, autonomous retransmission activation, or deactivation. Different values ​​for the second field can represent different indications.

[0249] For example, the second field has a length of 2 bits. When the second field is 00, it indicates that the polling enhancement scheme is active; when the second field is 01, it indicates that the autonomous retransmission scheme is active; and when the second field is 10, it indicates that the retransmission enhancement scheme is deactivated. It should be understood that other values ​​can also represent different indications, and this application embodiment does not limit this.

[0250] Next, we will explain in detail the several possible implementation methods of Scheme 1.

[0251] 1) In the first possible implementation of Scheme 1.

[0252] In the first possible implementation of Scheme 1, there are no restrictions on the specific implementation form of the retransmission enhancement scheme. That is, there are no restrictions on the triggering conditions of the retransmission enhancement scheme.

[0253] Next, using the first indication information indicating whether to use the retransmission enhancement scheme and which retransmission enhancement scheme to use through polling the activation status of the enhancement scheme, the activation status of the autonomous retransmission scheme, and the deactivation status of the retransmission enhancement scheme as an example, the first possible implementation of Scheme 1 will be explained in detail with reference to the accompanying drawings.

[0254] Please refer to Figure 10, which shows a flowchart of the first possible implementation of Scheme 1 in this application, which may include the following steps:

[0255] S1001: The RLC entity of the first device performs PDU transmission.

[0256] By default, retransmission enhancement schemes are not used during PDU transmission by RLC entities. For example, RLC entities can perform normal retransmission mechanisms during PDU transmission.

[0257] Among them, the ordinary retransmission mechanism can be the ARQ retransmission mechanism. The ARQ retransmission mechanism includes a status report-based retransmission mechanism, and may also include a polling mechanism, etc.

[0258] In one embodiment, during uplink transmission between the first device and the second device, the RLC entity of the first device can transmit PDUs with the RLC entity of the second device.

[0259] S1002: The second device sends a first instruction message 1 to the first device. The first instruction message 1 carries the activation status of the polling enhancement scheme. Accordingly, the first device receives the first instruction message 1.

[0260] The first instruction information 1, by carrying the polling enhancement scheme activation status, can instruct the first device to activate the polling enhancement scheme, that is, instruct the first device to use the polling enhancement scheme.

[0261] As an example, when the first indication information 1 is MAC CE, the second field in MAC CE can be 00 to indicate that the first indication information 1 carries the polling enhancement scheme activation status.

[0262] S1003: The first device's RLC entity executes a polling enhancement scheme.

[0263] After receiving the first instruction information 1, the first device can execute the polling enhancement scheme according to the corresponding RLC entity of the first device. This RLC entity is the RLC entity associated with the instruction granularity of the first instruction information 1.

[0264] In this embodiment, the specific implementation of the polling enhancement scheme is not limited, that is, the triggering conditions of the polling enhancement scheme are not limited. The implementation of the polling enhancement scheme includes: triggering the polling enhancement scheme when the triggering conditions are met.

[0265] As an example, the triggering conditions for a polling enhancement scheme may include at least one of the following triggering conditions.

[0266] 1) The remaining lifetime of data packets in the transmission window is less than or equal to a certain duration threshold. This duration threshold can be configured by the second device.

[0267] 2) Data packets within the transmission window are designated as delay-critical packets. Delay-critical packets can be indicated by PDCP. For example, an RLC entity can trigger polling upon receiving a delay-critical indication from the PDCP layer.

[0268] 3) The number of PDUs or bytes sent reaches a certain threshold. For example, the number of PDUs or bytes sent since the last polling has reached a certain threshold. In other words, polling can be triggered periodically based on the number of PDUs or bytes sent.

[0269] 4) The number of SNs sent reaches a certain threshold. For example, the number of SNs sent since the last polling reaches a certain threshold. In other words, polling can be triggered periodically based on the number of SNs.

[0270] 5) The send buffer and / or retransmission buffer are empty. That is, polling can be triggered when the send buffer or retransmission buffer is empty.

[0271] 6) The sending window status meets the requirements. For example, when the sending window is blocked waiting for the receiver's acknowledgment (ACK) and cannot send new PDUs, polling can be triggered.

[0272] 7) Polling retransmit timer (t-PollRetransmit) timeout. For example, polling can be triggered if the polling retransmit timer times out and no status report is received. The polling retransmit timer can be started after a poll is triggered, such as after a PDU carrying the polling bit is sent.

[0273] 8) Triggered during the last transmission of a PDU set. For example, polling can be triggered when the last PDU in a PDU set is transmitted to request a status report after each PDU set transmission.

[0274] It should be understood that the triggering conditions for the polling enhancement scheme may also include other triggering conditions, and the specific triggering conditions can be set as needed. This application embodiment does not limit this.

[0275] In one embodiment, the polling enhancement scheme satisfies at least one of the following conditions compared to ordinary polling: subject to different prohibition timers, corresponding to different trigger condition parameters, allowing the receiving entity to handle the reassembly timer and / or prohibition timer in different ways, enhancing the retransmission procedure after receiving a status report based on polling enhancement, and stopping the polling enhancement of the corresponding RLC entity when the packet delay budget (PDB) of the service data stream is reached. Ordinary polling refers to the traditional polling mechanism.

[0276] In the implementation of this application, the triggering conditions for the polling enhancement scheme can be pre-configured by the second device or indicated by the first indication information.

[0277] As an example, when the first indication information 1 carries the polling enhancement scheme activation status, the first indication information 1 may also carry first configuration information. The first configuration information includes parameters related to the triggering conditions of the polling enhancement scheme, so that the first device triggers the polling enhancement scheme according to the first configuration information. For example, the first configuration information may include at least one of: trigger duration threshold, trigger count threshold, trigger period, and serial number (SN) period.

[0278] In one implementation, the polling enhancement scheme includes triggering polling when transmitting the next data packet to be transmitted, for example, by carrying polling indication information in the next data packet to be transmitted, the polling indication information being used to trigger polling, for example, the polling indication information being P=1. For example, polling is triggered when transmitting the next data packet to be transmitted to a second device.

[0279] It should be noted that during the execution of the polling enhancement scheme, the scheme can be triggered once or multiple times. For example, polling can be triggered every time the triggering condition of the polling enhancement scheme is met.

[0280] S1004: The second device sends a first instruction message 2 to the first device. The first instruction message 2 carries the activation status of the autonomous retransmission scheme. Accordingly, the first device receives the first instruction message 2.

[0281] The first instruction information 2, by carrying the autonomous retransmission scheme activation status, can instruct the first device to activate the autonomous retransmission scheme, that is, instruct the first device to use the autonomous retransmission scheme.

[0282] It should be noted that the information format and type of the first indication information 2 are the same as those of the first indication information 1, and will not be repeated here in this embodiment. The difference lies in the data content carried by the first indication information 2 and the first indication information 1. For example, when the first indication information 2 is a MAC CE, the second field in the MAC CE can be 01 to indicate that the first indication information 2 carries the active status of the autonomous retransmission scheme.

[0283] S1005: The RLC entity of the first device stops executing the polling enhancement scheme.

[0284] After the first device receives the first instruction information 2, the polling enhancement scheme of the RLC entity of the first device can be automatically deactivated, so that the RLC entity of the first device stops executing the polling enhancement scheme.

[0285] In other words, once the first device receives the new first instruction information, the old first instruction information can be automatically deactivated.

[0286] In another embodiment, during the process of the RLC entity of the first device executing the polling enhancement scheme according to the first indication information 1, the first device may also receive the first indication information 3 sent by the second device. Based on the first indication information 3, the RLC entity of the first device can stop executing the polling enhancement scheme. The first indication information 3 carries the deactivation state of the retransmission enhancement scheme.

[0287] In other words, the activation state of the retransmission enhancement scheme can also be used to control the execution of the already activated retransmission enhancement scheme.

[0288] S1006: The RLC entity of the first device executes the autonomous retransmission scheme.

[0289] When the first device receives the first instruction information 2, the corresponding RLC entity of the first device can stop executing the polling enhancement scheme and execute the autonomous retransmission scheme.

[0290] In this embodiment, the specific implementation of the autonomous retransmission scheme is not limited, that is, the triggering conditions of the autonomous retransmission scheme are not limited. The implementation of the polling enhancement scheme includes: triggering the polling enhancement scheme when the triggering conditions are met.

[0291] As an example, the triggering conditions for an autonomous retransmission scheme may include at least one of the following triggering conditions.

[0292] 1) The remaining lifetime of the data packets in the transmission window is less than or equal to a certain duration threshold.

[0293] 2) Triggering for delayed critical data packets. For example, if a data packet in the transmission window is indicated as a delayed critical data packet, an autonomous retransmission can be triggered for that delayed critical data packet.

[0294] 3) Triggering retransmission for PDUs whose importance in the PDU set meets the requirements. For example, retransmitting PDUs with high PSI.

[0295] 4) Triggering for PDUs in an unknown state after the initial transmission of all PDUs in a PDU set is completed. For example, after the initial transmission of all PDUs in a PDU set is completed, PDUs in an unknown state in the PDU set can be retransmitted.

[0296] 5) The polling retransmission timer timeout is triggered for delayed critical data packets. For example, if the polling retransmission timer times out, delayed critical data packets will be retransmitted.

[0297] 6) Transmission gaps or channel quality meet requirements. For example, retransmitting RLC SDUs when channel quality deteriorates ensures the reliability of transmission of relevant RLC SDUs.

[0298] 7) Data stream ends or transmission window stalls. For example, if a new RLC PDU cannot be sent due to the end of the data stream or the stalling of the transmission window, the sender of the RLC entity can retransmit a PDU that has already been sent and whose status is unknown in order to avoid a locked state.

[0299] In one embodiment, the autonomous retransmission scheme satisfies at least one of the following conditions compared to normal retransmission: the transmission priority of autonomous retransmission is higher than that of normal retransmission; transmission resources for autonomous retransmission are scheduled after all PDUs of a burst are transmitted; and autonomous retransmission of the corresponding RLC entity is stopped when the PDB of the service data stream is reached.

[0300] Among them, normal retransmission refers to retransmission based on status reports, that is, retransmission performed after receiving NACK.

[0301] In the implementation of this application, the triggering conditions for the retransmission enhancement scheme can be pre-configured by the second device or indicated by the first indication information.

[0302] As an example, when the first indication information 2 carries the activation status of the autonomous enhancement scheme, the first indication information 2 may also carry second configuration information, which includes parameters related to the triggering conditions of the autonomous retransmission scheme. For example, the second configuration information may include at least one of: a trigger duration threshold, a trigger channel quality threshold, and a trigger transmission gap length.

[0303] In one implementation, triggering an autonomous retransmission scheme includes retransmitting data packets that have been sent but whose reception status is unknown. For example, retransmitting data packets that have been sent but whose reception status is unknown to a second device.

[0304] It should be noted that the autonomous retransmission scheme can be triggered once or multiple times during its execution. For example, an autonomous retransmission can be triggered each time the triggering conditions of the autonomous retransmission scheme are met.

[0305] S1007: The second device sends a first instruction message 3 to the first device. The first instruction message 3 carries the deactivation status of the retransmission enhancement scheme. Accordingly, the first device receives the first instruction message 3.

[0306] S1008: The RLC entity of the first device stops executing the retransmission enhancement scheme.

[0307] The RLC entity of the first device can stop executing the already executed retransmission enhancement scheme, such as stopping the already executed autonomous retransmission scheme, based on the first instruction information 3.

[0308] For example, the first device can activate the already activated autonomous retransmission scheme based on the retransmission enhancement scheme deactivation state carried by the first instruction information 3, thereby stopping the autonomous retransmission scheme. That is, after receiving the first instruction information 3 carrying the retransmission enhancement scheme deactivation state, the first instruction information 2 can automatically deactivate it.

[0309] It should be noted that the first indication information 3 and the first indication information 1 have the same information format and type, which will not be repeated here in this embodiment. The difference lies in the data content carried by the first indication information 3 and the first indication information 1. For example, when the first indication information 3 is MAC CE, the second field in MAC CE can be 10 to indicate that the first indication information 3 carries the deactivation status of the retransmission enhancement scheme.

[0310] In one embodiment, during PDU transmission, if a PDU has been successfully received (e.g., an ACK has been received for that PDU), no further retransmission is performed for that PDU. For example, when implementing a retransmission enhancement scheme, the scheme can be applied to PDUs that have already been sent and whose status is unknown. This helps reduce system power consumption and avoid unnecessary retransmissions.

[0311] In this embodiment, the first device can trigger a polling enhancement scheme or an autonomous retransmission scheme based on the indication information of the second device. This can improve the flexibility of the first device in executing the retransmission enhancement scheme and help optimize data transmission performance.

[0312] 2) The second possible implementation method in Scheme 1.

[0313] In the second implementation of Scheme 1, a duration threshold or a number of executions threshold can be introduced, and the execution of the retransmission enhancement scheme will be stopped when the execution duration or number of executions exceeds the corresponding threshold.

[0314] In one embodiment, the duration threshold or the number of times threshold can be configured by a second device.

[0315] As an example, the second device can configure a first threshold and a corresponding timer / counter for the first device. The first threshold may include a first duration threshold or a first count threshold, used to indicate the maximum execution duration or maximum number of executions of the retransmission enhancement scheme. The timer is used to count the execution duration of the retransmission enhancement scheme. The counter is used to count the number of executions of the retransmission enhancement scheme. The first device can stop executing the retransmission enhancement scheme based on the first threshold and the corresponding timer / counter during the execution of the retransmission enhancement scheme.

[0316] For example, the second device can configure a first duration threshold and a corresponding second timer for the first device. The second timer is used to count the execution duration of the retransmission enhancement scheme. The first device can start the second timer when it receives a first indication message indicating the use of the retransmission enhancement scheme or when the retransmission enhancement scheme begins to execute. When the duration of the second timer reaches the first duration threshold, the execution of the retransmission enhancement scheme is stopped.

[0317] In addition, after the second timer is started, if a first instruction message is received indicating the use of other retransmission enhancement schemes or the execution of other retransmission enhancement schemes is started, the second timer can be reset so that the second timer starts timing again.

[0318] For example, the second device can configure a first count threshold and a corresponding first counter for the first device. The first counter is used to count the number of times the retransmission enhancement scheme is executed. The first device can start the first counter when it receives a first indication message indicating that the retransmission enhancement scheme should be used or when the retransmission enhancement scheme starts to be executed. The first counter counts the number of times the retransmission enhancement scheme is executed. When the count of the first counter reaches the first count threshold, the execution of the retransmission enhancement scheme stops.

[0319] In addition, after the first counter is started, if a first instruction message is received indicating the use of other retransmission enhancement schemes or other retransmission enhancement schemes are started, the first counter can be reset so that the first counter starts counting again.

[0320] Next, taking the first indication information as an example to indicate which retransmission enhancement scheme to use by polling the activation status of the enhancement scheme and the autonomous retransmission scheme, and the second device configuring a first duration threshold and a corresponding second timer for the first device, and configuring the maximum execution time of the retransmission enhancement scheme by the first duration threshold, the second possible implementation method of Scheme 1 will be described in detail with reference to the accompanying drawings.

[0321] Please refer to Figure 11, which shows a flowchart illustrating a second possible implementation of Scheme 1 in this application. The embodiment in Figure 11 additionally introduces a first duration threshold and a corresponding second timer. As shown in Figure 11, the steps include:

[0322] S1101: The second device configures a first duration threshold and a second timer for the first device.

[0323] As an example, the second device can be configured to set the timing duration of the second timer to a first duration threshold.

[0324] Thus, if the second timer's timing duration reaches the set duration, or if the second timer times out, it means that the second timer's timing duration has reached the first duration threshold.

[0325] S1102: The RLC entity of the first device performs PDU transmission.

[0326] S1103: The second device sends a first instruction message 1 to the first device. The first instruction message 1 carries the activation status of the polling enhancement scheme. Accordingly, the first device receives the first instruction message 1.

[0327] Upon receiving the first instruction information 1, the first device can activate the polling enhancement scheme based on the activation status of the polling enhancement scheme carried by the first instruction information 1.

[0328] S1104: The first device starts the second timer.

[0329] In this embodiment of the application, after receiving the first instruction information 1, or after the polling enhancement scheme is activated, the first device can start the second timer to count the execution time of the polling enhancement scheme.

[0330] In one embodiment, the second timer can be configured in the RLC layer, or it can be configured in other layers such as the PDCP layer. This application does not limit this.

[0331] S1105: The first device's RLC entity executes a polling enhancement scheme.

[0332] It should be noted that the embodiments of this application are only examples of starting the second timer immediately after receiving the first instruction information 1. It should be understood that the first device may also start the second timer after receiving the first instruction information 1 when starting to execute the polling enhancement scheme, or after receiving the first instruction information 1 when the polling enhancement scheme is triggered for the first time. The embodiments of this application do not limit this.

[0333] S1106: The second device sends a first instruction message 2 to the first device. The first instruction message 2 carries the activation status of the autonomous retransmission scheme. Accordingly, the first device receives the first instruction message 2.

[0334] In one embodiment, before the duration of the second timer of the first device reaches a first duration threshold, the second device may send a first indication message 2 to the first device as needed. For example, the second device may send the first indication message 2 based on data reception status or congestion status.

[0335] S1107: The RLC entity of the first device stops executing the polling enhancement scheme.

[0336] After receiving the first instruction information 2, the second device can stop executing the polling enhancement scheme and activate the autonomous retransmission scheme according to the autonomous retransmission scheme activation status carried by the first instruction information 2.

[0337] In other words, upon receiving a new first instruction message (such as first instruction message 2), the old first instruction message (such as first instruction message 1) can be automatically deactivated.

[0338] In another embodiment, during the process of the RLC entity of the first device executing the polling increment scheme according to the first instruction information 1, the duration of the second timer reaches the first duration threshold.

[0339] S1108: If the first device receives the first instruction information 2 before the second timer's timing duration reaches the first duration threshold, then the second timer is reset.

[0340] In this embodiment of the application, if a new first indication message is received before the second timer reaches the first duration threshold, the second timer can be reset, that is, the second timer can be restarted so that the second timer starts counting again, so as to use the second timer to count the execution duration of the retransmission enhancement scheme (such as the autonomous retransmission scheme) used by the new indication.

[0341] S1109: The RLC entity of the first device executes the autonomous retransmission scheme.

[0342] It should be noted that the embodiments of this application only take the immediate reset of the second timer after receiving the first instruction information 2 as an example. It should be understood that the first device may also start the second timer after receiving the first instruction information 2 when starting to execute the autonomous retransmission scheme, or after receiving the first instruction information 2 when the autonomous retransmission scheme is triggered for the first time. The embodiments of this application do not limit this.

[0343] It should also be noted that the embodiments of this application are only examples of receiving the first indication information 2 before the second timer reaches the first duration threshold, and switching to the autonomous retransmission scheme based on the first indication information 2. It should be understood that if no new first indication information (such as the first indication information 2) is received when the second timer reaches the first duration threshold, the RLC entity of the first device can also stop executing the polling enhancement scheme and will not switch to other retransmission enhancement schemes.

[0344] S1110: When the RLC entity of the first device reaches the first duration threshold of the second timer, it stops executing the autonomous retransmission scheme.

[0345] For example, if the duration of the second timer is the first duration threshold, the RLC entity of the first device can stop executing the autonomous retransmission scheme when the second timer times out, such as deactivating the autonomous retransmission scheme.

[0346] In this way, the autonomous retransmission scheme can be stopped when the execution time reaches the first time threshold, thus avoiding excessively long or frequent execution times, saving system power consumption, and avoiding unnecessary autonomous retransmissions.

[0347] S1111: The RLC entity of the first device continues to transmit PDUs.

[0348] After the autonomous retransmission scheme is stopped, during subsequent PDU transmission, the RLC entity of the first device will no longer execute the retransmission enhancement scheme, such as only executing normal retransmission, like ARQ retransmission.

[0349] It should be noted that, in the embodiments of this application, the specific implementation form of the retransmission enhancement scheme may or may not be limited, such as limiting the implementation form of the retransmission enhancement scheme to be triggered based on the remaining lifetime of the data packet. The embodiments of this application do not limit this.

[0350] In this embodiment, the first device can trigger a polling enhancement scheme or an autonomous retransmission scheme based on the indication information from the second device. This improves the flexibility of the first device in executing the retransmission enhancement scheme and helps optimize data transmission performance. Furthermore, the first device can control the execution duration or number of retransmission enhancement schemes based on duration or frequency thresholds configured by the second device, preventing excessively long execution times or too many retransmissions. This reduces system load and avoids unnecessary retransmissions.

[0351] 3) The third possible implementation of Scheme 1.

[0352] In the third possible implementation of Scheme 1, the specific implementation of the retransmission enhancement scheme can be restricted to be triggered based on the remaining lifetime of the data packet (also known as remaining time to live or remaining duration). That is, the triggering condition of the retransmission enhancement scheme is restricted, and the triggering condition is that the remaining lifetime of the data packet is less than a certain duration threshold.

[0353] For example, the implementation of the polling enhancement scheme includes: if the remaining lifetime of a data packet is less than or equal to a certain duration threshold, the polling enhancement scheme is triggered. The implementation of the autonomous retransmission scheme includes: if the remaining lifetime of a data packet is less than or equal to a certain duration threshold, the autonomous retransmission scheme is triggered.

[0354] In one embodiment, the duration threshold in the triggering condition described above can be configured by the second device. For example, the second device can configure a trigger duration threshold, as well as a corresponding timer and / or timer parameters, for the first device. The duration of the timer is used to determine the remaining lifetime of the data packet.

[0355] Next, taking the first indication information as an example to indicate whether to use the retransmission enhancement scheme and which retransmission enhancement scheme to use by polling the activation status of the enhancement scheme, the activation status of the autonomous retransmission scheme, and the deactivation status of the retransmission enhancement scheme, and the second device configuring the first trigger duration threshold and the corresponding first timer for the first device, the third possible implementation of Scheme 1 will be explained in detail with reference to the accompanying drawings.

[0356] Please refer to Figure 12, which shows a flowchart illustrating a third possible implementation of Scheme 1 in this application. The embodiment in Figure 12 additionally introduces a first trigger duration threshold and a corresponding first timer. As shown in Figure 12, the steps include:

[0357] S1201, the second device configures a first trigger duration threshold and a first timer for the first device.

[0358] The first trigger duration threshold can be indicated by the second device as the trigger duration threshold for either the polling enhancement scheme or the autonomous retransmission scheme. The duration of the first timer is used to determine the remaining lifetime of the data packet.

[0359] In one embodiment, the second device can configure a first trigger duration threshold and a first timer at the RLC layer of the first device. The first timer can be started when the RLC layer receives a PDU from the upper layer (PDCP layer) or transmits a PDU to the lower layer (MAC layer).

[0360] In another embodiment, the second device may also configure a first trigger duration threshold and a first timer at the PDCP layer of the first device. The first timer can be started when the PDCP layer receives a PDU from the upper layer or transmits a PDU to the lower layer (RLC layer).

[0361] It should be noted that, in addition to configuring a new first timer at the corresponding protocol layer of the first device, an existing timer at the corresponding protocol layer can also be reused as the first timer. For example, if the first trigger duration threshold is configured at the PDCP layer, the second device may not configure a new first timer at the PDCP layer of the first device and may reuse an existing timer at the PDCP layer as the first timer. For example, the first timer can be a discard timer at the PDCP layer.

[0362] For the PDCP or RLC layer, PDUs typically have a remaining time to live (TTL) when they arrive at the layer. The TTL limits how long a PDU can remain in the network. For example, a PDU from an upper layer usually includes a field indicating its remaining TTL. This mechanism ensures that PDUs do not exist indefinitely in the network, thus avoiding waste of network resources and potential congestion.

[0363] In this embodiment of the application, for the PDCP layer or RLC layer, after the PDU arrives at this layer, the first timer of this layer can be started to continue to count the remaining lifetime of the PDU. For example, the first timer of this layer can be started when a PDU is received from the upper layer or when a PDU is transmitted to the lower layer.

[0364] In one embodiment, the remaining lifetime of the first PDU in this layer can be determined based on the remaining lifetime of the first PDU when it arrives at this layer and the duration of the first timer.

[0365] Here, the first PDU is any PDU received by this layer from the upper layer. For example, the remaining lifetime of the first PDU upon arrival at this layer can be determined based on a field containing the first PDU indicating its remaining lifetime. It should be understood that the remaining lifetime of the first PDU upon arrival at this layer can also be determined in other ways, and this embodiment of the application does not limit this.

[0366] As an example, if the first timer starts counting down, it can begin counting down from the remaining lifetime of the first PDU when it arrives at this layer, and the real-time countdown length of the first timer will be used as the remaining lifetime of the first PDU. For instance, assuming the remaining lifetime of the first PDU when it arrives at the RLC layer is 10ms, the first timer can start counting down from 10ms after it starts, and when the countdown reaches 6ms, the remaining lifetime of the first PDU is 6ms.

[0367] As another example, if the first timer is counting forward, the difference between the first remaining lifetime of the first PDU and the forward count of the first timer can be taken as the remaining lifetime of the first PDU. For example, assuming the remaining lifetime of the first PDU to reach the RLC layer is 10ms, the first timer can start counting forward from 0. When the forward count is 4ms, the remaining lifetime of the first PDU is 6ms.

[0368] For ease of explanation, this application embodiment uses the example of configuring a first trigger duration threshold and a first timer in the RLC layer of a first device, and starting the first timer when the RLC layer receives a PDU from the upper layer.

[0369] S1202, The RLC entity of the first device performs PDU transmission.

[0370] S1203, the second device sends first instruction information 1 to the first device. The first instruction information 1 carries the activation status of the polling enhancement scheme. Accordingly, the first device receives the first instruction information 1.

[0371] After receiving the first indication information 1, the first device can activate the polling enhancement scheme to trigger the polling enhancement scheme when the triggering conditions are met. In this embodiment, the polling enhancement scheme can be triggered when the remaining lifetime of the data packet is less than the first triggering duration threshold.

[0372] S1204. When the RLC entity of the first device receives the PDU from the upper layer, it starts the first timer.

[0373] Whenever the RLC entity of the first device receives a PDU sent by the upper layer, it can start a first timer corresponding to that PDU in order to determine the remaining lifetime of the PDU through the corresponding first timer.

[0374] S1205. When the remaining lifetime of the first PDU is less than or equal to the first trigger duration threshold, the RLC entity of the first device triggers the polling enhancement scheme.

[0375] The first PDU can be any PDU that has been received from the upper layer and whose reception status is unknown. The remaining lifetime of the first PDU refers to the real-time remaining lifetime of the first PDU after it reaches the RLC layer, which can be determined based on the duration of the first timer.

[0376] In one embodiment, the first device may determine the remaining lifetime of the first PDU based on the duration of a first timer. For example, the remaining lifetime of the first PDU may be determined based on the remaining lifetime of the first PDU when it reaches the RLC layer and the duration of the first timer.

[0377] As an example, if the first timer counts down and the remaining lifetime of the first PDU when it reaches the RLC layer is 10ms, and the first trigger duration threshold is 6ms, then after the first timer starts, it can start counting down from 10ms. When the countdown reaches 6ms, the remaining lifetime of the first PDU is 6ms, which is less than or equal to the first trigger duration threshold of 6ms. At this time, the polling enhancement scheme can be triggered.

[0378] As another example, if the first timer is counting forward, the difference between the first remaining lifetime of the first PDU and the forward count of the first timer can be used as the remaining lifetime of the first PDU. For example, assuming the remaining lifetime of the first PDU to reach the RLC layer is 10ms and the first trigger duration threshold is 6ms, the first timer can start counting forward from 0. When the forward count is 4ms, the remaining lifetime of the first PDU is 6ms, which is less than or equal to the first trigger duration threshold of 6ms. At this time, the polling enhancement scheme can be triggered.

[0379] In one embodiment, triggering the polling enhancement scheme includes triggering the polling enhancement scheme when transmitting the next PDU to be transmitted. For example, the next PDU to be transmitted carries polling indication information used to trigger polling. For instance, the next PDU to be transmitted carries a polling bit P=1.

[0380] In this way, when transmitting the next PDU, the peer RLC entity can be triggered to poll and send back a status report, so that the RLC entity of the first device can obtain the status report sent back by the peer RLC entity in a timely manner, determine the reception status of the PDU with an unknown status based on the status report, and retransmit the PDU with a reception status of NACK in a timely manner.

[0381] S1206. If the remaining lifetime of the second PDU is less than the first trigger duration threshold, the RLC entity of the first device triggers the polling enhancement scheme.

[0382] The second PDU is a PDU that the RLC entity has sent but whose reception status is unknown.

[0383] It should be noted that after activating the polling enhancement scheme based on the first indication information 1, the first device can trigger the polling enhancement scheme once or multiple times. For example, a polling enhancement scheme is triggered whenever the remaining lifetime of a received or transmitted PDU is less than a first trigger duration threshold. In this embodiment, triggering two polling enhancement schemes is used as an example.

[0384] S1207. The second device sends a first instruction message 2 to the first device. The first instruction message 2 carries the activation status of the autonomous retransmission scheme. Accordingly, the first device receives the first instruction message 2.

[0385] S1208, The RLC entity of the first device stops executing the polling enhancement scheme.

[0386] Upon receiving the first instruction information 2, the RLC entity of the first device can stop executing the polling enhancement scheme and activate the autonomous retransmission scheme, so as to trigger the autonomous retransmission scheme when the triggering conditions of the autonomous retransmission scheme are met. In this embodiment of the application, the autonomous retransmission scheme can be triggered when the remaining lifetime of the data packet is less than or equal to the first triggering time threshold.

[0387] S1209: When the RLC entity of the first device receives the PDU from the upper layer, it starts the first timer.

[0388] S1210: The RLC entity of the first device triggers the autonomous retransmission scheme if the remaining lifetime of the third PDU is less than or equal to the first trigger duration threshold.

[0389] The third PDU is a PDU that the RLC entity has received but whose reception status is unknown.

[0390] The method for determining the remaining lifetime of the third PDU can refer to the method for determining the remaining lifetime of the first PDU, and will not be repeated here in the embodiments of this application.

[0391] S1211: The second device sends a first instruction message 3 to the first device. The first instruction message 3 carries the retransmission enhancement scheme deactivation status. Accordingly, the first device receives the first instruction message 3.

[0392] S1212: The RLC entity of the first device stops executing the autonomous retransmission scheme.

[0393] S1213: The RLC entity of the first device continues to transmit PDUs.

[0394] After the autonomous retransmission scheme is stopped, during subsequent PDU transmission, the RLC entity of the first device will no longer execute the retransmission enhancement scheme, such as only executing normal retransmission, like ARQ retransmission.

[0395] In one embodiment, after a data packet (such as a PDU) is successfully received, the first timer corresponding to that data packet may or may not stop counting. For example, if the first timer is a new timer configured at the RLC layer or PDCP layer, then the first timer corresponding to that data packet may stop counting after the data packet is successfully received. If the first timer is a multiplexed PDCP layer discard timer, then the first timer corresponding to that data packet may continue counting after the data packet is successfully received.

[0396] It should be noted that, based on the third possible implementation of Scheme 1, a duration threshold or a number of times threshold can also be introduced, and the retransmission enhancement scheme will be stopped when the execution duration or number of times the retransmission enhancement scheme is executed exceeds the corresponding threshold. This application embodiment will not elaborate on this in detail.

[0397] In this embodiment, the first device can trigger a polling enhancement scheme or an autonomous retransmission scheme based on the remaining lifetime of the data packet according to the instruction information of the second device. This can improve the flexibility of the first device in executing the retransmission enhancement scheme and help optimize data transmission performance.

[0398] Option 2: Trigger a joint retransmission enhancement scheme based on the first indication information.

[0399] In Scheme 2, the first indication information can indicate whether to use the retransmission enhancement scheme, and when indicating the use of the retransmission enhancement scheme, indicate which one to use: the priority polling enhancement scheme or the priority autonomous retransmission scheme.

[0400] After receiving the first indication information from the network device, the first device executes the priority polling enhancement scheme if the first indication information indicates that the priority polling enhancement scheme should be used; executes the priority autonomous retransmission scheme if the first indication information indicates that the priority autonomous retransmission scheme should be used; and does not execute the retransmission enhancement scheme if the first indication information indicates that the retransmission enhancement scheme should not be used, such as stopping the execution of the activated retransmission enhancement scheme.

[0401] In one example, the first indication information may include the activation status of the priority polling enhancement scheme, the activation status of the priority autonomous retransmission scheme, or the deactivation status of the retransmission enhancement scheme.

[0402] Among them, the priority polling enhancement scheme activation status is used to indicate the activation of the priority polling enhancement scheme, that is, to indicate the use of the priority polling enhancement scheme; the priority autonomous retransmission scheme activation status is used to indicate the activation of the priority autonomous retransmission scheme, that is, to indicate the use of the priority autonomous retransmission scheme; and the retransmission enhancement scheme deactivation status is used to deactivate the activated retransmission enhancement scheme, that is, to indicate that the retransmission enhancement scheme is not used.

[0403] Next, taking MAC CE as an example as the first instruction information, we will explain one possible format of MAC CE.

[0404] As an example, a MAC CE can include a MAC CE header and data fields.

[0405] The MAC CE subheader may include a first field. This first field indicates that the MAC CE is the first indication information. For example, the first field may be LCID or eLCID.

[0406] The MAC CE data fields may include a second field. This second field indicates whether a retransmission enhancement scheme is used, and which scheme—priority polling or priority autonomous retransmission—is used. For example, the second field indicates the retransmission enhancement scheme status, which may include priority polling activation, priority autonomous retransmission activation, or deactivation. Different values ​​for the second field can represent different indications.

[0407] For example, the second field has a length of 2 bits. When the second field is 00, it indicates that the priority polling enhancement scheme is active; when the second field is 01, it indicates that the priority autonomous retransmission scheme is active; and when the second field is 10, it indicates that the retransmission enhancement scheme is deactivated. It should be understood that other values ​​can also represent different indication functions, and this application embodiment does not limit this.

[0408] In this embodiment of the application, the priority polling enhancement scheme refers to the priority execution of the polling enhancement scheme, and the execution of the autonomous retransmission scheme when no status report (SR) has been received while the triggering conditions of the autonomous retransmission scheme are met; the priority autonomous retransmission scheme refers to the priority execution of the autonomous retransmission scheme, and the triggering of the polling enhancement scheme when the autonomous retransmission scheme is executed, as an example.

[0409] The status report indicates the reception status of sent data packets. For example, the reception status includes ACK or NACK, where ACK indicates that the corresponding data packet was successfully received, and NACK indicates that the corresponding data packet was not successfully received. Under the ARQ retransmission mechanism, data packet retransmission can be triggered based on the status report; for example, data packets with a reception status of NACK can be retransmitted.

[0410] It should be understood that in other embodiments, the priority autonomous retransmission scheme may also refer to prioritizing the execution of the autonomous retransmission scheme, and executing the polling enhancement scheme if no status report is received when the triggering conditions of the polling enhancement scheme are met. This application embodiment will not elaborate on this in detail.

[0411] Next, we will explain in detail the several possible implementation methods of Scheme 1.

[0412] 1) The first possible implementation of Scheme 2.

[0413] In the first possible implementation of Scheme 2, there are no restrictions on the specific implementation form of the retransmission enhancement scheme. That is, there are no restrictions on the triggering conditions of the retransmission enhancement scheme.

[0414] Next, taking the first indication information indicating whether to use the retransmission enhancement scheme and which joint retransmission enhancement scheme to use through the priority polling enhancement scheme activation status, priority autonomous retransmission scheme activation status, and retransmission enhancement scheme deactivation status as an example, the first possible implementation of Scheme 1 will be described in detail with reference to the accompanying drawings.

[0415] Please refer to Figure 13, which shows a schematic flowchart of the first possible implementation of Scheme 2 in this application, including the following steps:

[0416] S1301, The RLC entity of the first device performs PDU transmission.

[0417] S1302, the second device sends a first instruction message 1 to the first device. The first instruction message 1 carries the activation status of the priority polling enhancement scheme. Accordingly, the first device receives the first instruction message 1.

[0418] The first instruction information 1, by carrying the activation status of the priority polling enhancement scheme, can instruct the first device to activate the priority polling enhancement scheme, that is, instruct the first device to use the priority polling enhancement scheme.

[0419] As an example, when the first indication information 1 is MAC CE, the second field in MAC CE can be 00 to indicate that the first indication information 1 carries the activation status of the priority polling enhancement scheme.

[0420] S1303, Enhanced polling scheme for the RLC entity of the first device.

[0421] In one embodiment, the RLC entity of the first device executing the polling enhancement scheme includes: triggering the polling enhancement scheme when the triggering conditions of the polling enhancement scheme are met.

[0422] In this embodiment, the triggering conditions for the polling enhancement scheme are not limited. For example, they can be any of the triggering conditions for the polling enhancement scheme described in the embodiment of Figure 10 above, or other triggering conditions. This embodiment does not limit these conditions.

[0423] In one embodiment, triggering the polling enhancement scheme includes triggering the polling enhancement scheme when transmitting the next PDU to be transmitted. For example, the next PDU to be transmitted carries polling indication information used to trigger polling. For instance, the next PDU to be transmitted carries a polling bit P=1.

[0424] S1304. If the RLC entity of the first device has not received the SR when the triggering conditions of the autonomous retransmission scheme are met, the autonomous retransmission scheme is triggered.

[0425] In this embodiment, the triggering conditions for the autonomous retransmission scheme are not limited. For example, they can be any of the triggering conditions for the autonomous retransmission scheme described in the embodiment of Figure 10 above, or other triggering conditions. This embodiment does not limit these conditions.

[0426] In one embodiment, the triggering condition for the autonomous retransmission scheme can be pre-configured, for example, pre-configured by a second device, or indicated by a first indication message, for example, carried in the first indication message during transmission. This application embodiment does not limit this.

[0427] In one embodiment, triggering an autonomous retransmission scheme includes retransmitting data packets that have been sent but whose reception status is unknown.

[0428] In another embodiment, if the RLC entity of the first device receives an SR before the triggering condition of the autonomous retransmission scheme is met, it will not execute the retransmission enhancement scheme, for example, it will not execute any retransmission enhancement scheme. Here, the SR is used to indicate the reception status of the transmitted data packets. The reception status may include acknowledgment (ACK) or negative acknowledgment (NACK).

[0429] In addition, after receiving an SR, retransmission based on the SR can be performed. For example, when the SR indicates that the reception status of a data packet is NACK, the data packet can be retransmitted.

[0430] S1305, the second device sends a first instruction message 2 to the first device. The first instruction message 2 carries the activation status of the priority autonomous retransmission scheme. Accordingly, the first device receives the first instruction message 2.

[0431] The first instruction information 2, by carrying the priority autonomous retransmission scheme activation status, can instruct the first device to activate the priority autonomous retransmission scheme, that is, instruct the first device to use the priority autonomous retransmission scheme.

[0432] It should be noted that the information format and type of the first indication information 2 are the same as those of the first indication information 1, and will not be repeated here in this embodiment. The difference lies in the data content carried by the first indication information 2 and the first indication information 1. For example, when the first indication information 2 is a MAC CE, the second field in the MAC CE can be 01 to indicate that the first indication information 2 carries the activation status of the priority autonomous retransmission scheme.

[0433] S1306, The RLC entity of the first device stops executing the priority polling enhancement scheme.

[0434] After receiving the first instruction information 2, the priority polling enhancement scheme of the RLC entity of the first device can be automatically deactivated, so that the RLC entity of the first device stops executing the priority polling enhancement scheme.

[0435] In another embodiment, during the process of the RLC entity of the first device executing the priority polling enhancement scheme according to the first indication information 1, the first device may also receive the first indication information 3 sent by the second device. Based on the first indication information 3, the RLC entity of the first device can stop executing the priority polling enhancement scheme. The first indication information 3 carries the retransmission enhancement scheme deactivation status.

[0436] S1307. The RLC entity of the first device executes the autonomous retransmission scheme and triggers the polling enhancement scheme when executing the autonomous retransmission scheme.

[0437] As an example, the RLC entity of the first device can retransmit a PDU that has been sent but whose reception status is unknown, and carry polling indication information in the retransmitted PDU to trigger polling. For example, the polling bit P=1 is carried in the first retransmitted PDU.

[0438] It should be noted that the embodiments of this application are only examples of the implementation of the priority autonomous retransmission scheme, which prioritizes the execution of the autonomous retransmission scheme and triggers the polling enhancement scheme when the autonomous retransmission scheme is executed. It should be understood that the implementation of the priority autonomous retransmission scheme can also be that the autonomous retransmission scheme is executed first, and the polling enhancement scheme is triggered when the triggering conditions of the polling enhancement scheme are met but no SR has been received.

[0439] S1308, the second device sends a first instruction message 3 to the first device. The first instruction message 3 carries the retransmission enhancement scheme deactivation status. Accordingly, the first device receives the first instruction message 3.

[0440] S1309, The RLC entity of the first device stops executing the priority autonomous retransmission scheme.

[0441] S1310, the RLC entity of the first device continues to transmit PDUs.

[0442] After the priority autonomous retransmission scheme is stopped, during subsequent PDU transmission, the RLC entity of the first device will no longer execute the retransmission enhancement scheme, such as only executing normal retransmission, like ARQ retransmission.

[0443] The first device can activate the already activated priority autonomous retransmission scheme based on the retransmission enhancement scheme carried by the first instruction information 3, thereby stopping the priority autonomous retransmission scheme. That is, after receiving the first instruction information 3 carrying the retransmission enhancement scheme deactivation status, the first instruction information 2 can automatically deactivate it.

[0444] It should be noted that the first indication information 3 and the first indication information 1 have the same information format and type, which will not be repeated here in this embodiment. The difference lies in the data content carried by the first indication information 3 and the first indication information 1. For example, when the first indication information 3 is MAC CE, the second field in MAC CE can be 10 to indicate that the first indication information 3 carries the deactivation status of the retransmission enhancement scheme.

[0445] In one embodiment, when the first indication information includes the activation status of the priority polling enhancement scheme or the activation status of the priority autonomous retransmission scheme, the first indication information may further include corresponding configuration information, which includes trigger condition parameters of the corresponding retransmission enhancement scheme, so that the first device can execute the corresponding retransmission enhancement scheme based on the configuration information.

[0446] As an example, when the first indication information includes the activation status of the priority polling enhancement scheme, the first indication information may also include first configuration information. The first configuration information may include parameters related to the triggering conditions of the polling enhancement scheme, and may also include parameters related to the triggering conditions of the autonomous retransmission scheme. After receiving such first indication information, the first device may trigger the polling enhancement scheme or the autonomous retransmission scheme based on the first configuration information.

[0447] As an example, when the first indication information includes the active status of the autonomous retransmission scheme, the first indication information may also include second configuration information. The second configuration information includes parameters related to the triggering conditions of the autonomous retransmission scheme, and may also include parameters related to the triggering conditions of the polling enhancement scheme. After receiving such first indication information, the first device may trigger the autonomous retransmission scheme or the polling enhancement scheme based on the second configuration information.

[0448] In one embodiment, during PDU transmission, if a PDU has been successfully received (e.g., an ACK has been received for that PDU), no further retransmission is performed for that PDU. For example, when implementing a retransmission enhancement scheme, the scheme can be applied to PDUs that have already been sent and whose status is unknown. This helps reduce system power consumption and avoid unnecessary retransmissions.

[0449] In this embodiment, the first device can trigger a joint retransmission enhancement scheme, such as a priority polling enhancement scheme or a priority autonomous retransmission scheme, based on the indication information of the second device. This can improve the flexibility of the first device in executing the retransmission enhancement scheme and help optimize data transmission performance.

[0450] 2) The second possible implementation of Scheme 2.

[0451] In the second implementation of Scheme 2, a duration threshold or a number of executions threshold can be introduced, and the execution of the retransmission enhancement scheme will be stopped when the execution duration or number of executions exceeds the corresponding threshold.

[0452] In one embodiment, the duration threshold or the number of times threshold can be configured by a second device.

[0453] As an example, the second device can configure a first threshold and a corresponding timer / counter for the first device. The first threshold may include a first duration threshold or a first count threshold, used to indicate the maximum execution duration or maximum number of executions of the retransmission enhancement scheme. The timer is used to count the execution duration of the retransmission enhancement scheme. The counter is used to count the number of executions of the retransmission enhancement scheme. The first device can stop executing the retransmission enhancement scheme based on the first threshold and the corresponding timer / counter during the execution of the retransmission enhancement scheme.

[0454] Next, taking the first indication information indicating which joint retransmission enhancement scheme to use through the priority polling enhancement scheme activation status and the priority autonomous retransmission scheme activation status, and the second device configuring a first duration threshold and a corresponding second timer for the first device as examples, the second possible implementation of Scheme 1 will be described in detail with reference to the accompanying drawings.

[0455] Please refer to Figure 14, which shows a schematic flowchart of the first possible implementation of Scheme 2 in this application. The embodiment in Figure 14 introduces a first duration threshold and a corresponding second timer in addition to the embodiment in Figure 13 described above. As shown in Figure 14, the method includes the following steps:

[0456] S1401, The second device configures a first duration threshold and a second timer for the first device.

[0457] As an example, the second device can be configured to set the timing duration of the second timer to a first duration threshold.

[0458] Thus, if the second timer's timing duration reaches the set duration, or if the second timer times out, it means that the second timer's timing duration has reached the first duration threshold.

[0459] S1402, The RLC entity of the first device performs PDU transmission.

[0460] S1403, the second device sends a first instruction message 1 to the first device. The first instruction message 1 carries the activation status of the priority polling enhancement scheme. Accordingly, the first device receives the first instruction message 1.

[0461] Upon receiving the first instruction information 1, the first device can activate the priority polling enhancement scheme based on the activation status of the priority polling enhancement scheme carried in the first instruction information 1.

[0462] S1404, The first device starts the second timer.

[0463] In this embodiment of the application, after receiving the first instruction information 1, or after the priority polling enhancement scheme is activated, the first device can start a second timer to count the execution time of the polling enhancement scheme.

[0464] S1405, Enhanced polling scheme for the RLC entity of the first device.

[0465] In one embodiment, executing the polling enhancement scheme includes: triggering the polling enhancement scheme when the triggering conditions of the polling enhancement scheme are met.

[0466] In one embodiment, the enhanced polling scheme includes triggering polling when transmitting the next PDU to be transmitted. For example, the next PDU to be transmitted carries polling indication information used to trigger polling. For example, the next PDU to be transmitted carries P=1.

[0467] S1406. If the RLC entity of the first device has not received the SR when the timing duration of the second timer is less than the first duration threshold, then the autonomous retransmission scheme shall be executed.

[0468] In other words, if the triggering conditions for the autonomous retransmission scheme are met before the second timer reaches the first duration threshold and no SR has been received at this time, the autonomous retransmission scheme can be triggered.

[0469] In one embodiment, implementing an autonomous retransmission scheme includes retransmitting PDUs that have been sent but whose reception status is unknown.

[0470] In one embodiment, when executing the autonomous retransmission scheme, a second timer can also be reset to time the execution duration of the autonomous retransmission scheme. Then, when the duration of the second timer reaches a first duration threshold, the execution of the autonomous retransmission scheme is stopped.

[0471] In this way, the execution time of the autonomous retransmission scheme can be further limited to the first time threshold to avoid long periods of autonomous retransmission, thereby reducing system power consumption and avoiding unnecessary retransmissions.

[0472] In another embodiment, if the triggering condition of the autonomous retransmission scheme is not met before the second timer's duration reaches the first duration threshold, the polling enhancement scheme can be stopped when the second timer's duration reaches the first duration threshold. This limits the execution time of the polling enhancement scheme to the first duration threshold, avoiding prolonged polling enhancement, thereby reducing system power consumption and preventing unnecessary polling and retransmissions.

[0473] S1407. The second device sends a first instruction message 2 to the first device. The first instruction message 2 carries the activation status of the priority autonomous retransmission scheme. Accordingly, the first device receives the first instruction message 2.

[0474] The second device may send a first indication message 2 to the first device as needed before the second timer reaches a first duration threshold. For example, the second device may send the first indication message 2 to the first device based on data reception status or congestion status.

[0475] S1408, The RLC entity of the first device stops executing the priority polling enhancement scheme.

[0476] After receiving the first instruction information 2, the second device can stop executing the priority polling enhancement scheme and activate the priority autonomous retransmission scheme according to the priority autonomous retransmission scheme activation status carried by the first instruction information 2.

[0477] In one embodiment, when the RLC entity of the first device stops executing the priority polling enhancement scheme according to the first instruction information 2, it can stop executing the scheme being executed during the priority polling enhancement scheme process, such as stopping the autonomous retransmission scheme being executed in this embodiment.

[0478] S1409. If the first device receives the first instruction information 2 before the second timer's duration reaches the first duration threshold, then the second timer is reset.

[0479] In this embodiment of the application, if a new first indication message is received before the second timer reaches the first duration threshold, the second timer can be reset, that is, the second timer can be restarted so that the second timer starts counting again, so as to use the second timer to count the execution duration of the retransmission enhancement scheme used by the new indication.

[0480] It should be noted that the embodiments of this application are only examples of receiving the first indication information 2 before the second timer reaches the first duration threshold, and switching to the priority autonomous retransmission scheme based on the first indication information 2. It should be understood that if no new first indication information (such as the first indication information 2) is received when the second timer reaches the first duration threshold, the RLC entity of the first device can also stop executing the priority polling enhancement scheme and will not switch to other retransmission enhancement schemes.

[0481] S1410, The RLC entity of the first device executes the autonomous retransmission scheme and triggers the polling enhancement scheme when executing the autonomous retransmission scheme.

[0482] It should be noted that the embodiments of this application are only examples of the implementation of the priority autonomous retransmission scheme, which prioritizes the execution of the autonomous retransmission scheme and triggers the polling enhancement scheme when the autonomous retransmission scheme is executed. It should be understood that the implementation of the priority autonomous retransmission scheme can also be that the autonomous retransmission scheme is executed first, and the polling enhancement scheme is triggered when the triggering conditions of the polling enhancement scheme are met but no SR has been received.

[0483] In this embodiment, the triggering conditions for the polling enhancement scheme are not limited. For example, they can be any of the triggering conditions for the polling enhancement scheme described in the embodiment of Figure 10 above, or other triggering conditions. This embodiment does not limit these conditions.

[0484] S1411. When the RLC entity of the first device reaches the first duration threshold of the second timer, it stops executing the priority autonomous retransmission scheme.

[0485] For example, if the duration of the second timer is the first duration threshold, the RLC entity of the first device can stop executing the priority autonomous retransmission scheme when the second timer expires, such as deactivating the priority autonomous retransmission scheme.

[0486] In this way, the execution of the priority autonomous retransmission scheme can be stopped when the execution time reaches the first time threshold, thus avoiding the execution time of the priority autonomous retransmission scheme being too long or too frequent, thereby saving system power consumption and avoiding unnecessary autonomous retransmission and polling.

[0487] S1412, The RLC entity of the first device continues to transmit PDUs.

[0488] After the priority autonomous retransmission scheme is stopped, during subsequent PDU transmission, the RLC entity of the first device will no longer execute the retransmission enhancement scheme, such as only executing normal retransmission, like ARQ retransmission.

[0489] In this embodiment, the first device can trigger a joint retransmission enhancement scheme, such as a priority polling enhancement scheme or a priority autonomous retransmission scheme, based on the indication information from the second device. This improves the flexibility of the first device in executing the retransmission enhancement scheme and helps optimize data transmission performance. Furthermore, the first device can control the execution duration or number of retransmission enhancement schemes based on duration or frequency thresholds configured by the second device, preventing excessively long execution times or too many executions. This reduces system load and avoids unnecessary retransmission enhancements.

[0490] 3) The third possible implementation of Scheme 2.

[0491] In the third possible implementation of Scheme 2, the specific implementation of the restricted retransmission enhancement scheme is based on the remaining lifetime (also known as remaining time to live) of the data packet. That is, the triggering condition for the restricted retransmission enhancement scheme is that the remaining lifetime of the data packet is less than a certain time threshold.

[0492] For example, the implementation of the priority polling enhancement scheme includes: if the remaining lifetime of the data packet is less than or equal to the larger of two duration thresholds, the polling enhancement scheme is triggered; if no status report is received when the remaining lifetime of the data packet is less than or equal to the smaller of the two duration thresholds, the autonomous retransmission scheme is triggered. The third trigger duration threshold is less than the second trigger duration threshold.

[0493] For example, the implementation of the priority autonomous retransmission scheme includes: if the remaining lifetime of the data packet is less than or equal to the larger of two duration thresholds, the autonomous retransmission scheme is triggered, and a polling enhancement scheme is triggered during autonomous retransmission. Alternatively, if the remaining lifetime of the data packet is less than or equal to the larger of two duration thresholds, the autonomous retransmission scheme is triggered, and if no status report is received when the remaining lifetime of the data packet is less than or equal to the smaller of the two duration thresholds, the polling enhancement scheme is triggered.

[0494] The two duration thresholds in the above triggering conditions can be configured by the second device. For example, the second device can configure two trigger duration thresholds for the first device, along with corresponding timers and / or timer parameters. These two trigger duration thresholds are used to trigger the two retransmission enhancement schemes in the joint retransmission enhancement scheme, respectively. The duration of the timer is used to determine the remaining lifetime of the data packet.

[0495] In the first embodiment, the first indication information can indicate which joint retransmission enhancement scheme the first device should use, and the joint retransmission enhancement scheme indicated by the first indication information can be triggered in conjunction with a configured trigger duration threshold. For example, the second device can configure two trigger duration thresholds for the first device: a second trigger duration threshold and a third trigger duration threshold, and does not restrict the retransmission enhancement schemes corresponding to these two trigger duration thresholds. The first indication information indicates whether a retransmission enhancement scheme is used and which joint retransmission enhancement scheme is used. For example, the first indication information includes a priority polling enhancement scheme activation state, a priority autonomous retransmission scheme activation state, and a retransmission enhancement scheme deactivation state.

[0496] As an example, suppose the second trigger duration threshold is greater than the third trigger duration threshold. The first device executing a joint retransmission enhancement scheme based on the first indication information may include: if the first indication information indicates the use of a priority polling enhancement scheme, triggering the polling enhancement scheme when the remaining lifetime of the first data packet is less than or equal to the second trigger duration threshold; if no status report is received when the remaining lifetime of the first data packet is less than or equal to the third trigger duration threshold, triggering a deliberate retransmission scheme, where the first data packet is a data packet that has been sent and whose reception status is unknown. Alternatively, if the first indication information indicates the use of a priority deliberate retransmission scheme, triggering the deliberate retransmission scheme, or triggering both the deliberate retransmission scheme and the polling enhancement scheme, when the remaining lifetime of the first data packet is less than or equal to the second trigger duration threshold; if no status report is received when the remaining lifetime of the first data packet is less than or equal to the third trigger duration threshold, triggering either the polling enhancement scheme, or triggering both the deliberate retransmission scheme and the polling enhancement scheme.

[0497] In the second embodiment, the first device can be instructed to use a joint retransmission enhancement scheme by combining the first indication information and the configured trigger duration threshold. For example, the second device can configure two trigger duration thresholds for the first device: a fourth trigger duration threshold and a fifth trigger duration threshold, and restrict the fourth trigger duration threshold to be the trigger duration threshold for the polling enhancement scheme, and the fifth trigger duration threshold to be the trigger duration threshold for the autonomous retransmission scheme. The first indication information indicates whether the retransmission enhancement scheme is used. For example, the first indication information includes the retransmission enhancement scheme activation status and the retransmission enhancement scheme deactivation status.

[0498] As an example, the first device executing a joint retransmission enhancement scheme based on the first indication information and configuration information may include: if the first indication information indicates the use of a retransmission enhancement scheme, and if the fourth trigger duration threshold is greater than the fifth trigger duration threshold, then if the remaining lifetime of the first data packet is less than or equal to the fourth trigger duration threshold, a polling enhancement scheme is triggered; if no status report is received when the remaining lifetime of the first data packet is less than or equal to the fifth trigger duration threshold, then a deliberate retransmission scheme is triggered. Alternatively, if the first indication information indicates the use of a retransmission enhancement scheme, and the fourth trigger duration threshold is less than the fifth trigger duration threshold, then if the remaining lifetime of the first data packet is less than or equal to the fifth trigger duration threshold, a deliberate retransmission scheme, or a combination of the deliberate retransmission scheme and the polling enhancement scheme, is triggered; if no status report is received when the remaining lifetime of the first data packet is less than or equal to the fourth trigger duration threshold, then a polling enhancement scheme, or a combination of the deliberate retransmission scheme and the polling enhancement scheme, is triggered.

[0499] For example, if the first indication information indicates the use of a retransmission enhancement scheme, and the fourth trigger duration threshold is less than the fifth trigger duration threshold, then if the remaining lifetime of the first data packet is less than or equal to the fifth trigger duration threshold, an autonomous retransmission scheme is triggered, and a polling enhancement scheme is triggered during the execution of the autonomous retransmission scheme. Alternatively, if no status report is received when the remaining lifetime of the first data packet is less than or equal to the fourth trigger duration threshold, a polling enhancement scheme may be triggered, or it may not be triggered, or both the autonomous retransmission scheme and the polling enhancement scheme may be triggered again; this embodiment does not limit this.

[0500] For example, if the first indication message indicates the use of the retransmission enhancement scheme, and the fourth trigger duration threshold is less than the fifth trigger duration threshold, then the autonomous retransmission scheme is triggered if the remaining lifetime of the first data packet is less than or equal to the fifth trigger duration threshold. Subsequently, if no status report is received when the remaining lifetime of the first data packet is less than or equal to the fourth trigger duration threshold, then the polling enhancement scheme is triggered.

[0501] Next, the first example will be described in detail with reference to the first indication information, which includes the activation status of the priority polling enhancement scheme, the activation status of the priority autonomous retransmission scheme, and the deactivation status of the retransmission enhancement scheme, indicating whether to use the retransmission enhancement scheme and which joint retransmission enhancement scheme to use. The second device configures two trigger duration thresholds T1 and T2 for the first device, as well as the corresponding first timer.

[0502] Please refer to Figure 15, which shows a schematic flowchart of a third possible implementation of Scheme 2 in this application. The embodiment in Figure 15 introduces two additional trigger duration thresholds (T1, T2) and a corresponding first timer based on the embodiment in Figure 13. As shown in Figure 15, the method includes the following steps:

[0503] S1501, The second device configures two trigger duration thresholds [T1, T2] and a first timer for the first device, where T1 > T2.

[0504] T1 and T2 are two trigger duration thresholds used to trigger the joint retransmission enhancement scheme (priority polling enhancement scheme and priority autonomous retransmission scheme). The duration of the first timer is used to determine the remaining lifetime of the data packet.

[0505] The first timer can be configured at the RLC layer or the PDCP layer of the first device. This embodiment uses the configuration of the first timer at the RLC layer as an example. The specific configuration of the trigger duration threshold and the first timer can be referred to the relevant description in the embodiment of Figure 12 above, and will not be repeated here.

[0506] S1502, The RLC entity of the first device performs PDU transmission.

[0507] S1503, the second device sends a first instruction message 1 to the first device. The first instruction message 1 carries the activation status of the priority polling enhancement scheme. Accordingly, the first device receives the first instruction message 1.

[0508] After receiving the first instruction information 1, the first device can activate the priority polling enhancement scheme to trigger the priority polling enhancement scheme when the corresponding triggering conditions are met.

[0509] S1504. When the RLC entity of the first device receives the PDU from the upper layer, it starts the first timer.

[0510] Whenever the RLC entity of the first device receives a PDU sent by the upper layer, it can start a first timer corresponding to that PDU in order to determine the remaining lifetime of the PDU through the corresponding first timer.

[0511] S1505. When the remaining lifetime of the RLC entity of the first device is less than or equal to T1, the polling enhancement scheme is triggered.

[0512] Here, PDU1 can be any PDU received from the upper layer or any PDU that has been sent to the lower layer; this embodiment does not limit this. The remaining lifetime of PDU1 refers to the real-time remaining lifetime of PDU1 after it reaches the RLC layer, which can be determined based on the duration of the first timer. For the specific determination method, please refer to the relevant description in the embodiment of Figure 12 above; this embodiment will not repeat it here.

[0513] As an example, if the first timer counts down, and the remaining lifetime of PDU1 when it reaches the RLC layer is 10ms, T1 is 6ms, and T2 is 5ms, then after the first timer starts, it can start counting down from 10ms. When the countdown reaches 6ms, the remaining lifetime of PDU1 is 6ms, which is less than or equal to T1. At this time, the polling enhancement scheme can be triggered.

[0514] As an example, the enhanced polling scheme includes carrying polling indication information in the next PDU to be transmitted, which is used to trigger polling. For example, the polling indication information can be P=1, meaning P=1 is carried in the next PDU to be transmitted.

[0515] S1506. If the RLC entity of the first device has not received the SR when the remaining lifetime of PDU1 is less than or equal to T2, the autonomous retransmission scheme is triggered.

[0516] As an example, after the first timer counts down to 6ms, the countdown can continue. When the first timer counts down to 5ms, the remaining lifetime of PDU1 is 5ms, which is less than or equal to T2. If the first device has not yet received SR at this time, the autonomous retransmission scheme can be triggered.

[0517] As an example, triggering autonomous retransmission includes retransmitting PDU1.

[0518] In another embodiment, if the RLC entity of the first device receives the SR before the remaining lifetime of PDU1 is less than or equal to T2, it does not execute the retransmission enhancement scheme, for example, it no longer executes any retransmission enhancement scheme.

[0519] Additionally, SR-based retransmissions can be performed after receiving the SR. For example, if the SR indicates a NACK for the receive status of PDU1, then PDU1 can be retransmitted.

[0520] S1507, the second device sends a first instruction message 2 to the first device. The first instruction message 2 carries the activation status of the autonomous retransmission scheme. Accordingly, the first device receives the first instruction message 2.

[0521] The second device can send the first instruction information 2 to the first device when needed, for example, based on the data reception status or congestion status.

[0522] S1508, The RLC entity of the first device stops executing the priority polling enhancement scheme.

[0523] Upon receiving the first instruction information 2, the RLC entity of the first device can stop executing the priority polling enhancement scheme and activate the priority autonomous retransmission scheme, so as to trigger the priority autonomous retransmission scheme when the corresponding triggering conditions are met. That is to say, after receiving the new first instruction information, the old first instruction information can be automatically deactivated.

[0524] S1509. When the RLC entity of the first device receives the PDU from the upper layer, it starts the first timer.

[0525] S1510. When the remaining lifetime of PDU2 is less than or equal to T1, the RLC entity of the first device retransmits PDU2, and the retransmitted PDU2 carries polling indication information.

[0526] PDU2 is a PDU that the RLC entity has received or sent.

[0527] The method for determining the remaining lifetime of PDU2 can be referred to the relevant description in the embodiment of Figure 12 above, and will not be repeated here in the embodiments of this application.

[0528] It should be noted that the embodiments in this application only use the implementation of the priority autonomous retransmission scheme as an example, where the autonomous retransmission scheme is executed first, and the polling enhancement scheme is triggered when the autonomous retransmission scheme is executed. It should be understood that the implementation of the priority autonomous retransmission scheme can also be that the autonomous retransmission scheme is executed first, and the polling enhancement scheme is triggered when the triggering condition of the polling enhancement scheme is met but no SR has been received. For example, step S1511 can also be replaced by: retransmitting PDU2 when the remaining lifetime of PDU2 is less than or equal to T1; if an SR is received before the remaining lifetime of PDU2 is less than or equal to T2, the retransmission enhancement scheme is not executed; if an SR has not been received when the remaining lifetime of PDU2 is less than or equal to T2, the polling enhancement scheme is triggered.

[0529] S1511, the second device sends a first instruction message 3 to the first device. The first instruction message 3 carries the deactivation status of the retransmission enhancement scheme. Accordingly, the first device receives the first instruction message 3.

[0530] S1512, The RLC entity of the first device stops executing the priority autonomous retransmission scheme.

[0531] S1513, The RLC entity of the first device continues to transmit PDUs.

[0532] After the autonomous retransmission scheme is stopped, during subsequent PDU transmission, the RLC entity of the first device will no longer execute the retransmission enhancement scheme, such as only executing normal retransmission, like ARQ retransmission.

[0533] In this embodiment, the first device can trigger a joint retransmission enhancement scheme, such as a priority polling enhancement scheme or a priority autonomous retransmission scheme, based on the indication information from the second device. This improves the flexibility of the first device in executing the retransmission enhancement scheme and helps optimize data transmission performance. Furthermore, during the execution of the joint retransmission enhancement scheme, the first device can also trigger the retransmission enhancement scheme based on the remaining lifetime of the data packet, according to the duration threshold configured by the second device. This further enhances the flexibility of executing the retransmission enhancement scheme.

[0534] Next, the second example will be explained in detail with reference to the first indication information indicating whether the retransmission enhancement scheme is used, the activation status of the retransmission enhancement scheme and the deactivation status of the retransmission enhancement scheme, the second device configuring two trigger duration thresholds poll_T and AT_T for the first device, and the corresponding first timer.

[0535] Please refer to Figure 16, which shows another schematic flowchart of a third possible implementation of Scheme 2 in this application embodiment. As shown in Figure 16, it includes the following steps:

[0536] S1601, The second device configures two trigger duration thresholds [poll_T and AT_T] and a first timer for the first device.

[0537] Where poll_T is the trigger duration threshold for the polling enhancement scheme, and AT_T is the trigger duration threshold for the autonomous retransmission scheme. The duration of the first timer is used to determine the remaining lifetime of the data packet.

[0538] The first timer can be configured at the RLC layer or the PDCP layer of the first device. This embodiment uses the configuration of the first timer at the RLC layer as an example. The specific configuration of the trigger duration threshold and the first timer can be referred to the relevant description in the embodiment of Figure 12 above, and will not be repeated here.

[0539] S1602, The RLC entity of the first device performs PDU transmission.

[0540] S1603, the second device sends a first instruction message 1 to the first device. The first instruction message 1 carries the activation status of the retransmission enhancement scheme. Accordingly, the first device receives the first instruction message 1.

[0541] S1604. When the RLC entity of the first device receives the PDU from the upper layer, it starts the first timer.

[0542] Whenever the RLC entity of the first device receives a PDU sent by the upper layer, it can start a first timer corresponding to that PDU in order to determine the remaining lifetime of the PDU through the corresponding first timer.

[0543] It should be noted that the joint retransmission enhancement scheme executed by the first device varies depending on the sizes of poll_T and AT_T. For example, if poll_T is greater than AT_T, steps S1605-S1608 can be executed subsequently. If poll_T is less than AT_T, steps S1605-S1608 can be executed subsequently.

[0544] S1605. When poll_T is greater than AT_T, the RLC entity of the first device triggers the polling enhancement scheme when the remaining lifetime of PDU1 is less than or equal to poll_T.

[0545] Here, PDU1 can be any PDU received from the upper layer or any PDU that has been sent to the lower layer; this embodiment does not limit this. The remaining lifetime of PDU1 refers to the real-time remaining lifetime of PDU1 after it reaches the RLC layer, which can be determined based on the duration of the first timer. For the specific determination method, please refer to the relevant description in the embodiment of Figure 12 above; this embodiment will not repeat it here.

[0546] As an example, if the first timer counts down, and the remaining lifetime of PDU1 when it reaches the RLC layer is 10ms, poll_T is 6ms, and AT_T is 5ms, then after the first timer starts, it can start counting down from 10ms. When the countdown reaches 6ms, the remaining lifetime of PDU1 is 6ms, which is less than or equal to poll_T. At this time, the polling enhancement scheme can be triggered.

[0547] As an example, the enhanced polling scheme includes carrying polling indication information in the next PDU to be transmitted, which is used to trigger polling. For example, the polling indication information can be P=1, meaning P=1 is carried in the next PDU to be transmitted.

[0548] S1606. If the RLC entity of the first device has not received the SR when the remaining lifetime of PDU1 is less than or equal to AT_T, the autonomous retransmission scheme is triggered.

[0549] As an example, after the first timer counts down to 6ms, the countdown can continue. When the first timer counts down to 5ms, the remaining lifetime of PDU1 is 5ms, which is less than or equal to AT_T. If the first device has not yet received SR at this time, the autonomous retransmission scheme can be triggered.

[0550] As an example, triggering autonomous retransmission includes retransmitting PDU1.

[0551] In another embodiment, if the RLC entity of the first device receives the SR before the remaining lifetime of PDU1 is less than or equal to AT_T, it does not execute the retransmission enhancement scheme, for example, it does not execute any retransmission enhancement scheme.

[0552] Additionally, SR-based retransmissions can be performed after receiving the SR. For example, if the SR indicates a NACK for the receive status of PDU1, then PDU1 can be retransmitted.

[0553] S1607. The second device sends the first instruction information 2 to the first device. Correspondingly, the first device receives the first instruction information 2, which carries the retransmission enhancement scheme deactivation status.

[0554] S1608, The RLC entity of the first device stops executing the retransmission enhancement scheme.

[0555] When the first device receives the first instruction information 2, it can deactivate the first instruction information 1 to stop the execution of the already executed retransmission enhancement scheme, such as stopping the execution of the already executed autonomous retransmission scheme.

[0556] After the retransmission enhancement scheme stops, during subsequent PDU transmissions, the RLC entity of the first device will no longer execute the retransmission enhancement scheme; for example, it will only execute normal retransmissions, such as ARQ retransmissions.

[0557] S1609. When AT_T is greater than poll_T, the RLC entity of the first device triggers the autonomous retransmission scheme when the remaining lifetime of PDU1 is less than or equal to AT_T.

[0558] As an example, if the first timer counts down and the remaining lifetime of PDU1 when it reaches the RLC layer is 10ms, AT_T is 6ms, and poll_T is 5ms, then after the first timer starts, it can start counting down from 10ms. When the countdown reaches 6ms, the remaining lifetime of PDU1 is 6ms, which is less than or equal to AT_T. At this time, the autonomous retransmission scheme can be triggered.

[0559] As an example, triggering autonomous retransmission includes retransmitting PDU1.

[0560] In this way, PDUs can be retransmitted even if a NACK is not received, thereby increasing the probability of PDU retransmission, improving the probability of successful data packet transmission, and thus improving the timeliness and reliability of data transmission.

[0561] S1610. If the RLC entity of the first device has not received the SR when the remaining lifetime of PDU1 is less than or equal to poll_T, the polling enhancement scheme is triggered.

[0562] As an example, the countdown can continue after the first timer has counted down to 6ms. When the first timer counts down to 5ms, the remaining lifetime of PDU1 is 5ms, which is less than or equal to poll_T. If the first device has not yet received the SR at this time, the polling enhancement scheme can be triggered.

[0563] As an example, the enhanced polling scheme includes carrying polling indication information in the next PDU to be transmitted, which is used to trigger polling. For example, the polling indication information can be P=1, meaning P=1 is carried in the next PDU to be transmitted.

[0564] In another embodiment, if the RLC entity of the first device receives the SR before the remaining lifetime of PDU1 is less than or equal to poll_T, it does not execute the retransmission enhancement scheme, for example, it does not execute any retransmission enhancement scheme.

[0565] Additionally, SR-based retransmissions can be performed after receiving the SR. For example, if the SR indicates a NACK for the receive status of PDU1, then PDU1 can be retransmitted.

[0566] S1611, the second device sends the first instruction information 2 to the first device, and the first device receives the first instruction information 2 accordingly. The first instruction information 2 carries the retransmission enhancement scheme deactivation state.

[0567] S1612, The RLC entity of the first device stops executing the retransmission enhancement scheme.

[0568] When the first device receives the first instruction information 2, it can deactivate the first instruction information 1 to stop the execution of the already executed retransmission enhancement scheme, such as stopping the execution of the already executed polling enhancement scheme.

[0569] After the polling enhancement scheme stops, during subsequent PDU transmissions, the RLC entity of the first device will no longer execute the retransmission enhancement scheme; for example, it will only execute normal retransmissions, such as ARQ retransmissions.

[0570] It should be noted that the embodiments of this application are only illustrated by the example that the trigger duration threshold configured by the second device to the first device includes poll_T and AT_T. It should be understood that the trigger duration threshold configured by the second device may also include poll_T but not AT_T, or include AT_T but not poll_T.

[0571] In one embodiment, after receiving the first indication information 1 (carrying the retransmission enhancement scheme activation status), if the trigger duration threshold configured by the second device includes poll_T but does not include AT_T, then the polling enhancement scheme is triggered when the remaining lifetime of the data packet is less than poll_T; if the trigger duration threshold configured by the second device includes AT_T but does not include poll_T, then the autonomous retransmission scheme is triggered when the remaining lifetime of the data packet is less than AT_T.

[0572] Additionally, if the second device has neither poll_T nor AT_T configured, the first device may also ignore the first indication information sent by the second device, that is, not respond to the first indication information 1.

[0573] In this embodiment, the first device can be instructed to use a joint retransmission enhancement scheme by the first indication information and the configured trigger duration threshold. This expands the way the first device is instructed to execute the joint retransmission enhancement scheme, further improves the flexibility of executing the retransmission enhancement scheme, and helps to optimize data transmission performance.

[0574] Option 3, based on the first indication information, supports both the selectable retransmission enhancement scheme and the joint enhancement scheme.

[0575] In Scheme 3, the first indication information can indicate whether to use the retransmission enhancement scheme, and when indicating the use of the retransmission enhancement scheme, indicate which one of the following schemes should be used: polling enhancement scheme, autonomous retransmission scheme, priority polling enhancement scheme, and priority autonomous retransmission scheme.

[0576] After receiving the first indication information from the network device, the first device executes the polling enhancement scheme if the first indication information indicates that the polling enhancement scheme should be used; executes the autonomous retransmission scheme if the first indication information indicates that the autonomous retransmission scheme should be used; executes the priority polling enhancement scheme if the first indication information indicates that the priority polling enhancement scheme should be used; executes the priority autonomous retransmission scheme if the first indication information indicates that the priority autonomous retransmission scheme should be used; and does not execute the retransmission enhancement scheme if the first indication information indicates that the retransmission enhancement scheme should not be used, for example, by stopping the execution of the activated retransmission enhancement scheme.

[0577] In one example, the first indication information may include the activation status of the polling enhancement scheme, the activation status of the autonomous retransmission scheme, the activation status of the priority polling enhancement scheme, the activation status of the priority autonomous retransmission scheme, or the deactivation status of the retransmission enhancement scheme as an example.

[0578] Next, taking MAC CE as an example as the first instruction information, we will explain one possible format of MAC CE.

[0579] As an example, a MAC CE can include a MAC CE header and data fields.

[0580] The MAC CE subheader may include a first field. This first field indicates that the MAC CE is a first indication, i.e., a retransmission enhancement scheme indication. For example, the first field may be LCID or eLCID.

[0581] The MAC CE data fields may include a second field. This second field indicates whether a retransmission enhancement scheme is used, and if so, which of the following schemes is used: polling enhancement, autonomous retransmission, priority polling enhancement, or priority autonomous retransmission. For example, the second field indicates the retransmission enhancement scheme status, which may include polling enhancement activated, autonomous retransmission activated, priority polling enhancement activated, priority autonomous retransmission activated, or retransmission enhancement deactivated. Different values ​​for the second field can represent different indications.

[0582] For example, the second field is 3 bits long. When the second field is 000, it indicates that the polling enhancement scheme is active; when the second field is 001, it indicates that the autonomous retransmission scheme is active; when the second field is 010, it indicates that the priority polling enhancement scheme is active; when the second field is 011, it indicates that the priority autonomous retransmission scheme is active; and when the second field is 100, it indicates that the retransmission enhancement scheme is deactivated.

[0583] In one embodiment, the retransmission enhancement scheme can be further restricted to be triggered based on the remaining lifetime (also known as remaining time to live) of the data packet. That is, the triggering condition of the retransmission enhancement scheme is restricted, and the triggering condition is that the remaining lifetime of the data packet is less than or equal to a certain duration threshold.

[0584] For example, the implementation of the polling enhancement scheme includes: triggering the polling enhancement scheme if the remaining lifetime of the data packet is less than a certain lifetime threshold. The implementation of the discretionary retransmission scheme includes: triggering the discretionary retransmission scheme if the remaining lifetime of the data packet is less than or equal to a certain lifetime threshold. The implementation of the priority polling enhancement scheme includes: triggering the polling enhancement scheme if the remaining lifetime of the data packet is less than or equal to a certain lifetime threshold; if the SR (Signal Receiver) has not been received when the remaining lifetime of the data packet is less than or equal to a smaller lifetime threshold, then triggering the discretionary retransmission scheme. The implementation of the discretionary retransmission scheme includes: triggering the discretionary retransmission scheme if the remaining lifetime of the data packet is less than or equal to a certain lifetime threshold, and triggering the polling enhancement scheme when triggering the discretionary retransmission scheme. Alternatively, triggering the discretionary retransmission scheme if the remaining lifetime of the data packet is less than or equal to a certain lifetime threshold; if the SR has not been received when the remaining lifetime of the data packet is less than or equal to a smaller lifetime threshold, then triggering the polling enhancement scheme.

[0585] In one embodiment, the duration threshold in the triggering conditions described above can be configured by the second device. For example, the second device can configure multiple trigger duration thresholds, as well as corresponding timers and / or timer parameters, for the first device. The duration of the timer is used to determine the remaining lifetime of the data packet.

[0586] In one embodiment, after receiving the first indication information, the first device can trigger a retransmission enhancement scheme based on the remaining lifetime of the data packet according to the first information and multiple trigger duration thresholds.

[0587] For example, based on the first information and multiple trigger duration thresholds, the retransmission enhancement scheme triggered by the remaining lifetime of the data packet can include the following cases:

[0588] 1) If the first indication information indicates the use of the polling enhancement scheme, for example, if the first indication information carries the polling enhancement scheme activation status, then the polling enhancement scheme is triggered when the remaining lifetime of the first data packet is less than or equal to any one of the multiple trigger duration thresholds.

[0589] The first data packet is a data packet that has been sent but whose reception status is unknown, such as a PDU that has been sent but whose reception status is unknown.

[0590] As an example, a polling enhancement scheme is triggered when the remaining lifetime of the first data packet is less than or equal to a target trigger lifetime threshold among multiple trigger lifetime thresholds. The target trigger lifetime threshold is the trigger lifetime threshold among the multiple trigger lifetime thresholds that is less than and closest to the first remaining lifetime. The first remaining lifetime is the remaining lifetime of the first data packet when it is received.

[0591] For example, assuming multiple trigger duration thresholds include [T1, T2, T3], and T1 > T2 > T3, if the remaining lifetime of the first data packet is less than T1 when the first data packet is received, the polling enhancement scheme can be triggered when the remaining lifetime of the first data packet is less than or equal to T2.

[0592] In one embodiment, triggering the polling enhancement scheme includes triggering the polling enhancement scheme when transmitting the next data packet to be transmitted. For example, the next data packet to be transmitted carries polling indication information, such as carrying P=1.

[0593] 2) If the first indication information indicates the use of the autonomous retransmission scheme, for example, if the first indication information carries the autonomous retransmission scheme activation status, then the autonomous retransmission scheme is triggered when the remaining lifetime of the first data packet is less than or equal to any one of the multiple trigger duration thresholds.

[0594] As an example, an autonomous retransmission scheme is triggered when the remaining lifetime of the first data packet is less than or equal to the target trigger duration threshold among multiple trigger duration thresholds.

[0595] For example, assuming multiple trigger duration thresholds include [T1, T2, T3], and T1 > T2 > T3, if the remaining lifetime of the first data packet is less than T2 when the first data packet is received, then the autonomous retransmission scheme can be triggered when the remaining lifetime of the first data packet is less than or equal to T3.

[0596] In one embodiment, triggering an autonomous retransmission scheme includes retransmitting the first data packet.

[0597] 3) If the first indication information indicates the use of the priority polling enhancement scheme, for example, if the first indication information carries the priority polling enhancement scheme activation status, then the polling enhancement scheme is triggered when the remaining lifetime of the first data packet is less than or equal to the sixth triggering time threshold among multiple triggering time thresholds; if the SR has not been received when the remaining lifetime threshold of the first data packet is less than or equal to the seventh triggering time threshold, then the autonomous retransmission scheme is triggered.

[0598] The seventh trigger duration threshold is the first trigger duration threshold after the sixth trigger duration threshold, ordered in descending order among the multiple trigger duration thresholds. For example, assuming the multiple trigger duration thresholds include [T1, T2, T3], and T1 > T2 > T3, if the sixth trigger duration threshold is T1, then the seventh trigger duration threshold is T2; if the sixth trigger duration threshold is T2, then the seventh trigger duration threshold is T3.

[0599] The sixth trigger duration threshold is the trigger duration threshold among multiple trigger duration thresholds that is less than and closest to the first remaining lifetime. For example, assuming the multiple trigger duration thresholds include [T1, T2, T3], and T1 > T2 > T3, if the remaining lifetime of the first data packet is less than T1 when the first data packet is received, then the sixth trigger duration threshold is T2; if the remaining lifetime of the first data packet is less than T2 when the first data packet is received, then the sixth trigger duration threshold is T3.

[0600] In one embodiment, if an SR is received before the remaining duration threshold of the first data packet is less than or equal to the seventh trigger duration threshold, the retransmission enhancement scheme is not executed. Alternatively, after receiving an SR, SR-based retransmission can also be performed; for example, if the SR indicates that the reception status of the first data packet is NACK, then the first data packet is retransmitted.

[0601] As an example, suppose multiple trigger duration thresholds include [T1, T2, T3], and T1 > T2 > T3. If the remaining lifetime of the first data packet is less than T1 when the first data packet is received, the polling enhancement scheme can be triggered when the remaining lifetime of the first data packet is less than T2. ​​If the SR is received before the remaining lifetime threshold of the first data packet is less than T3, the retransmission enhancement scheme is not executed. If the SR is not received when the remaining lifetime threshold of the first data packet is less than T3, the autonomous retransmission scheme is triggered.

[0602] 4) If the first indication information indicates the use of the priority autonomous retransmission scheme, for example, if the first indication information carries the priority autonomous retransmission scheme activation status, then when the remaining lifetime of the first data packet is less than or equal to the eighth trigger duration threshold among multiple trigger duration thresholds, the autonomous retransmission scheme is triggered, or the autonomous retransmission scheme and the polling enhancement scheme are triggered; if no status report is received when the remaining lifetime threshold of the first data packet is less than or equal to the ninth trigger duration threshold, then the polling enhancement scheme is triggered, or the autonomous retransmission scheme and the polling enhancement scheme are triggered.

[0603] The ninth trigger duration threshold is the first trigger duration threshold after the eighth trigger duration threshold, ordered in descending order among the multiple trigger duration thresholds. For example, assuming the multiple trigger duration thresholds include [T1, T2, T3], and T1 > T2 > T3, if the eighth trigger duration threshold is T1, then the ninth trigger duration threshold is T2; if the eighth trigger duration threshold is T2, then the ninth trigger duration threshold is T3.

[0604] The ninth trigger duration threshold is the trigger duration threshold among multiple trigger duration thresholds that is less than and closest to the first remaining lifetime. For example, assuming that the multiple trigger duration thresholds include [T1, T2, T3], and T1 > T2 > T3, if the remaining lifetime of the first data packet is less than T1 when the first data packet is received, then the ninth trigger duration threshold is T2; if the remaining lifetime of the first data packet is less than T2 when the first data packet is received, then the ninth trigger duration threshold is T3.

[0605] In one possible implementation, taking the priority autonomous retransmission scheme as an example, which means prioritizing the execution of the autonomous retransmission scheme and triggering the polling enhancement scheme when executing the autonomous retransmission scheme, if the first indication information indicates the use of the priority autonomous retransmission scheme, then when the remaining lifetime of the first data packet is less than or equal to the eighth trigger duration threshold among multiple trigger duration thresholds, the autonomous retransmission scheme is triggered, and the polling enhancement scheme is triggered when the autonomous retransmission scheme is triggered; if the SR has not been received when the remaining lifetime threshold of the first data packet is less than or equal to the ninth trigger duration threshold, then the autonomous retransmission scheme is triggered again, and the polling enhancement scheme is triggered when the autonomous retransmission scheme is triggered.

[0606] For example, triggering the autonomous retransmission scheme and triggering the polling enhancement scheme when triggering the autonomous retransmission scheme includes: retransmitting the first data packet and carrying polling indication information in the retransmitted first data packet.

[0607] As an example, suppose multiple trigger duration thresholds include [T1, T2, T3], and T1 > T2 > T3. If the remaining lifetime of the first data packet is less than T1 when the first data packet is received, the first data packet can be retransmitted when the remaining lifetime of the first data packet is less than or equal to T2, and the polling indication information is carried in the retransmitted first data packet. If the SR is received before the remaining lifetime threshold of the first data packet is less than or equal to T3, the retransmission enhancement scheme is not executed. If the SR is not received when the remaining lifetime threshold of the first data packet is less than or equal to T3, the first data packet is retransmitted again, and the polling indication information is carried in the retransmitted first data packet.

[0608] In one possible implementation, taking the priority autonomous retransmission scheme as an example, which means prioritizing the execution of the autonomous retransmission scheme and triggering the polling enhancement scheme when the triggering conditions of the polling enhancement scheme are met, if the first indication information indicates the use of the priority autonomous retransmission scheme, then the autonomous retransmission scheme is triggered when the remaining lifetime of the first data packet is less than the eighth triggering lifetime threshold among multiple triggering lifetime thresholds; if no SR is received when the remaining lifetime threshold of the first data packet is less than the ninth triggering lifetime threshold, then the polling enhancement scheme is triggered.

[0609] For example, triggering a self-retransmission scheme includes retransmitting the first data packet. Triggering a polling enhancement scheme includes triggering polling when transmitting the next data packet to be transmitted, for example, by carrying polling indication information in the next data packet to be transmitted.

[0610] As an example, suppose multiple trigger duration thresholds include [T1, T2, T3], and T1 > T2 > T3. If the remaining lifetime of the first data packet is less than T1 when the first data packet is received, the first data packet can be retransmitted when the remaining lifetime of the first data packet is less than or equal to T2. If an SR is received before the remaining lifetime threshold of the first data packet is less than or equal to T3, the retransmission enhancement scheme is not executed. If an SR is not received when the remaining lifetime threshold of the first data packet is less than or equal to T3, the polling indication information is carried in the next data packet to be transmitted.

[0611] 5) If the first indication information indicates that the retransmission enhancement scheme is not used, for example, if the first indication information carries the retransmission enhancement activation status, then the retransmission enhancement scheme will not be executed.

[0612] For example, the first device can execute a normal retransmission scheme, such as ARQ retransmission, during data transmission.

[0613] In one embodiment, if the first device does not receive the first indication information, the first device will not execute the retransmission enhancement scheme.

[0614] In one embodiment, once a data packet is successfully received, it is discarded and no further retransmission is performed on it.

[0615] In this embodiment, the remaining lifetime of the data packet can be determined based on the duration of the first timer. The first timer can be configured at the RLC layer or the PDCP layer of the first device. This embodiment uses the configuration of the first timer at the RLC layer as an example. When the first timer is configured at the RLC layer, it can be started when a data packet is received from the upper layer (PDCP layer) or when a data packet is transmitted to the lower layer (MAC layer). This embodiment uses the start time of receiving a data packet from the upper layer as an example.

[0616] In one embodiment, after the first data packet is successfully received, the first timer corresponding to the first data packet may or may not stop counting. For example, if the first timer is a new timer configured at the RLC layer or PDCP layer, then the first timer corresponding to the first data packet may stop counting after the first data packet is successfully received. If the first timer is a multiplexed PDCP layer discard timer, then the first timer corresponding to the first data packet may continue counting after the first data packet is successfully received.

[0617] In one embodiment, for an implementation scheme that supports both selectable retransmission enhancement scheme and joint enhancement scheme based on the first indication information, a duration threshold or a number of times threshold may be introduced, and the execution of the retransmission enhancement scheme shall be stopped when the execution duration or number of times of the executed retransmission enhancement scheme exceeds the corresponding threshold.

[0618] In one embodiment, the duration threshold or the number of times threshold can be configured by a second device.

[0619] As an example, the second device can configure a first threshold and a corresponding timer / counter for the first device. The first threshold may include a first duration threshold or a first count threshold, used to indicate the maximum execution duration or maximum number of executions of the retransmission enhancement scheme. The timer is used to count the execution duration of the retransmission enhancement scheme. The counter is used to count the number of executions of the retransmission enhancement scheme. The first device can stop executing the retransmission enhancement scheme based on the first threshold and the corresponding timer / counter during the execution of the retransmission enhancement scheme.

[0620] For example, the second device can configure a first duration threshold and a corresponding second timer for the first device. The second timer is used to count the execution duration of the retransmission enhancement scheme. The first device can start the second timer when it receives a first indication message indicating the use of the retransmission enhancement scheme or when the retransmission enhancement scheme begins to execute. When the duration of the second timer reaches the first duration threshold, the execution of the retransmission enhancement scheme is stopped.

[0621] For example, the second device can configure a first-time count threshold and a corresponding first counter for the first device. The first counter is used to count the number of times the retransmission enhancement scheme is executed. The first device can start the first counter when it receives a first indication message indicating the use of the retransmission enhancement scheme or when the retransmission enhancement scheme starts to execute (such as when it is first triggered). The first counter counts the number of times the retransmission enhancement scheme is executed. When the count of the first counter reaches the first-time count threshold, the execution of the retransmission enhancement scheme stops.

[0622] It should be noted that for the joint retransmission enhancement scheme (priority polling enhancement scheme or priority autonomous retransmission scheme), the joint retransmission enhancement scheme can be controlled as a whole, or any retransmission enhancement scheme in the joint retransmission enhancement scheme can be controlled individually.

[0623] For example, the first device can start a timer / counter when it receives a first indication message instructing the use of a joint retransmission enhancement scheme or when the joint retransmission enhancement scheme begins execution. The timer / counter tracks the overall execution duration and counts the total number of executions of the joint retransmission enhancement scheme. When the timer / counter count reaches a corresponding threshold, the execution of the joint retransmission enhancement scheme is stopped. As another example, during the execution of the joint retransmission enhancement scheme, the first device can start a timer / counter when it begins execution of any retransmission enhancement scheme (polling enhancement scheme or autonomous retransmission scheme). The timer / counter tracks the execution duration and counts the number of executions of that retransmission enhancement scheme. When the timer / counter count reaches a corresponding threshold, the execution of that retransmission enhancement scheme is stopped.

[0624] To facilitate understanding of this application, the retransmission enhancement method provided in the embodiments of this application will be described in detail below, taking the first information as the self-judgment information of the first device as an example.

[0625] It should be noted that the execution of the first retransmission enhancement scheme based on the first device's own judgment information can include the following two implementation schemes: Scheme 4: Execute the retransmission enhancement scheme based on delay key indication information. Scheme 5: Execute the retransmission enhancement scheme based on content ratio information.

[0626] Next, we will explain these two options in detail.

[0627] Option 4: Implement a retransmission enhancement scheme based on critical delay indication information.

[0628] In Scheme 4, the first device can execute a retransmission enhancement scheme based on the third indication information. The third indication information indicates that the first data packet is a delay-critical data packet, and that the first data packet is a data packet that has been sent but whose reception status is unknown.

[0629] In one embodiment, the PDCP layer of the first device can send a third indication message to the RLC layer to indicate that the first data packet received by the RLC layer is a delay-critical data packet. The RLC entity of the first device can then execute a retransmission enhancement scheme based on the third indication message.

[0630] In one embodiment, the RLC entity of the first device can execute a retransmission enhancement scheme based on the third indication information and the transmission status of the first data packet. The transmission status of the first data packet can indicate whether the first data packet has undergone its initial transmission.

[0631] As an example, based on the third indication information and the transmission status of the first data packet, the retransmission enhancement scheme can be implemented in the following two cases:

[0632] 1) If the third indication information is obtained before the first data packet is transmitted for the first time, the polling enhancement scheme is triggered when the first data packet is transmitted for the first time.

[0633] For example, if the PDCP layer indicates that the first data packet is a delayed critical data packet before the RLC entity transmits the first data packet to the lower layer for the first time, that is, before the first data packet has completed its initial transmission, the RLC entity can trigger the polling enhancement scheme when transmitting the first data packet to the lower layer for the first time.

[0634] In one embodiment, triggering the polling enhancement scheme when the first data packet is transmitted for the first time includes: carrying polling indication information, such as carrying P=1, in the first data packet transmitted for the first time.

[0635] In one embodiment, if the third indication information is obtained before the first data packet is transmitted for the first time, and if the polling enhancement scheme is triggered when the first data packet is transmitted for the first time, and if the SR is not received when the triggering condition of the autonomous retransmission scheme is met, the autonomous retransmission scheme can still be executed for the first data packet.

[0636] In one embodiment, the triggering condition for the autonomous retransmission scheme can be that the remaining lifetime of the data packet is less than or equal to a certain duration threshold. For example, if an SR is not received when the remaining lifetime of the first data packet is less than or equal to the tenth trigger duration threshold, then the autonomous retransmission scheme is executed for the first data packet, such as retransmitting the first data packet.

[0637] The tenth trigger duration threshold can be configured by the second device. For example, the second device can pre-configure the tenth trigger duration threshold and a first timer for the first device. The duration of the first timer is used to determine the remaining lifetime of the data packet. The first timer can be configured at the RLC layer or the PDCP layer of the first device. This embodiment uses the configuration of the first timer at the RLC layer as an example. When the first timer is configured at the RLC layer, the first timer can be started when a data packet is received from the upper layer (PDCP layer) or when a data packet is transmitted to the lower layer (MAC layer). This embodiment uses the start timer when a data packet is received from the upper layer as an example.

[0638] As an example, the RLC entity of the first device can start a first timer when it receives a first data packet from the upper layer or sends a data packet to the lower layer, so as to determine the remaining lifetime of the first data packet by the duration of the first timer. Then, if the RLC entity of the first device obtains the third indication information before the first data packet is initially transmitted, it triggers the polling enhancement scheme when the first data packet is initially transmitted; if the SR is not received when the remaining lifetime of the first data packet is less than the tenth trigger duration threshold, the first data packet is retransmitted.

[0639] In another embodiment, if the SR is received before the triggering condition of the autonomous retransmission scheme is met, the retransmission enhancement scheme may not be executed. After receiving the SR, SR-based retransmission may also be performed. For example, if the SR indicates that the reception status of a data packet is NACK, the data packet may be retransmitted. For instance, if the SR indicates that the reception status of the first data packet is NACK, the first data packet may be retransmitted.

[0640] 2) If a third indication is obtained after the first data packet is transmitted for the first time, an autonomous retransmission scheme is executed for the first data packet.

[0641] For example, if the PDCP layer indicates that the first data packet is a delayed critical data packet after the RLC entity transmits the first data packet to the lower layer for the first time, that is, after the first data packet completes its initial transmission, the autonomous retransmission of the first data packet can be triggered, that is, the RLC entity retransmits the first data packet.

[0642] In one embodiment, performing an autonomous retransmission scheme for the first data packet includes retransmitting the first data packet.

[0643] In one example, if a third indication is obtained after the initial transmission of the first data packet, an autonomous retransmission of the first data packet can be triggered if the conditions for autonomous retransmission are met.

[0644] In one embodiment, the triggering condition for the autonomous retransmission scheme can be that the remaining lifetime of the data packet is less than or equal to a certain duration threshold. For example, if an SR is not received when the remaining lifetime of the first data packet is less than or equal to the tenth trigger duration threshold, then the autonomous retransmission scheme is executed for the first data packet, such as retransmitting the first data packet.

[0645] The tenth trigger duration threshold can be configured by the second device. For example, the second device can pre-configure the tenth trigger duration threshold and a first timer for the first device. The duration of the first timer is used to determine the remaining lifetime of the data packet. The first timer can be configured at the RLC layer or the PDCP layer of the first device. This embodiment uses the configuration of the first timer at the RLC layer as an example. When the first timer is configured at the RLC layer, the first timer can be started when a data packet is received from the upper layer (PDCP layer) or when a data packet is transmitted to the lower layer (MAC layer). This embodiment uses the start timer when a data packet is received from the upper layer as an example.

[0646] As an example, the RLC entity of the first device can start a first timer when it receives a first data packet from the upper layer or sends a data packet to the lower layer, so as to determine the remaining lifetime of the first data packet by the duration of the first timer. Then, if the RLC entity of the first device obtains the third indication information after the initial transmission of the first data packet, and has not received the SR when the remaining lifetime of the first data packet is less than the tenth trigger duration threshold, then the first data packet is retransmitted.

[0647] In another embodiment, if an SR is received before the triggering conditions of an autonomous retransmission scheme are met, no retransmission enhancement scheme may be executed. After receiving an SR, SR-based retransmission may also be performed. For example, if an SR indicates that the reception status of a data packet is NACK, the data packet may be retransmitted. For instance, if an SR indicates that the reception status of a first data packet is NACK, then the first data packet may be retransmitted.

[0648] In this embodiment of the application, by executing different retransmission enhancement schemes according to the different transmission states of the delayed critical data packets, some unnecessary retransmissions can be reduced, thereby reducing system consumption.

[0649] Option 5: Implement a retransmission enhancement scheme based on content ratio information.

[0650] In Option 5, the first device can execute a retransmission enhancement scheme based on the content ratio information.

[0651] Content ratio information refers to the ratio between the minimum number of data packets required for the receiver to successfully recover the data and the total number of data packets. For example, content ratio information can be represented as K / N, where K represents the minimum number of data packets required for the receiver to successfully recover the data, and N represents the total number of data packets.

[0652] In data transmission scenarios based on application layer forward error correction (AL-FEC) technology, the application layer can encode data packets using AL-FEC technology to generate repair data packets. When the original data packets are lost during transmission, the receiving end can use these repair data packets to recover the lost original data packets.

[0653] For example, the application layer can encode the data packets to be sent, generating N data packets. These N data packets may include a portion of the original data packets and a portion of the repaired data packets. The receiving end can reconstruct the actual content (such as video frames) upon receiving any K (K < N) data packets from the N data packets. The data packets transmitted by the application layer can be called application data units (ADUs). In other words, from the receiving end's perspective, receiving K data packets from the ADU is sufficient to reconstruct the actual content. This also means that once the receiving end successfully receives K data packets out of the N data packets composed of the ADU, transmitting the remaining NK data packets from the ADU to the receiving end will not add any value, because the receiving end can already reconstruct the original content based on the first K data packets.

[0654] From the sending end's perspective, the N Application Layer ADUs transmitted to the lower RLC layer can be referred to as N PDUs, and these N PDUs belong to the same PDU set. Each PDU in a PDU set carries a payload of one information unit generated at the application level, such as a frame or video slice. In other words, all PDUs in a PDU set correspond to a single frame or video slice payload at the application layer.

[0655] Therefore, for the RLC layer at the sending end, once the RLC layer successfully sends K PDUs from a PDU set to the receiving end, the receiving end can reconstruct the actual content based on the received K PDUs. This also means that once the sending end successfully sends K of the N PDUs in a PDU set, transmitting the remaining NK PDUs to the receiving end will not add any value, because the receiving end can already reconstruct the original content based on the first K PDUs.

[0656] In view of this, in order to save system resources and avoid transmitting unnecessary data packets, in this embodiment of the application, the first device can also determine the content ratio information and the reception ratio of the first PDU set, and execute a retransmission enhancement scheme based on the content ratio information and the reception ratio of the first PDU set. For example, if the reception ratio of the first PDU set is less than the content ratio information, then a retransmission enhancement scheme is executed for a specific PDU in the first PDU set.

[0657] Next, the retransmission enhancement method based on content ratio information provided in the embodiments of this application will be described in detail with reference to the accompanying drawings.

[0658] Please refer to Figure 17, which shows a schematic flowchart of a possible implementation of Scheme 5 in this application embodiment. As shown in Figure 17, it includes the following steps:

[0659] S1701: The first device determines the content ratio information and the reception ratio of the first PDU set.

[0660] The first device can determine the content ratio information and the reception ratio of the first PDU set during PDU transmission.

[0661] In one embodiment, the first device can obtain content ratio information from the network device, for example, by receiving content ratio information sent by the network device.

[0662] As an example, this content ratio information can be provided by core network equipment. For instance, network equipment can detect content ratio information from core network equipment and then send the content ratio information to the first equipment.

[0663] It should be understood that the first device may also obtain content ratio information through other means, and this application embodiment does not limit this.

[0664] In one embodiment, before determining the reception ratio of the first PDU set, the first device may also acquire PDU set information. This PDU set information indicates which PDUs belong to the same PDU set, i.e., which PDUs belong to a single PDU set. During PDU transmission, the number of PDUs successfully received in the first PDU set can be recorded based on the PDU set information to determine the reception ratio of the first PDU set.

[0665] As an example, the method provided in this application embodiment can be applied to the RLC layer of a first device. The PDCP layer of the first device can provide PDU set information to the RLC layer. The RLC layer can record the number of PDUs that have been successfully received in the first PDU set based on the PDU set information provided by the PDCP layer, and then determine the reception ratio of the first PDU set.

[0666] S1702: If the reception ratio of the first PDU set is less than the content ratio information, the first device executes a retransmission enhancement scheme for a specific PDU in the first PDU set.

[0667] In one embodiment, performing a retransmission enhancement scheme on specific PDUs in the first PDU set may include the following two cases:

[0668] 1) When the remaining lifetime of the second PDU in the first PDU set is less than or equal to the eleventh trigger duration threshold, if all PDUs in the first PDU set have completed their initial transmission, an autonomous retransmission scheme is executed for the second PDU, which is the PDU that has completed its initial transmission and whose reception status is unknown.

[0669] The eleventh trigger duration threshold is configured by the second device. The second device can be a network device.

[0670] In one embodiment, the second device can pre-configure an eleventh trigger duration threshold and a corresponding first timer for the first device, the duration of which is used to determine the remaining lifetime of the PDU.

[0671] In one embodiment, if the reception ratio of the first PDU set is less than the content ratio information, and after initial transmission of a certain PDU (the second PDU) in the first PDU set, the remaining lifetime of the second PDU is less than the eleventh trigger duration threshold, the initial transmission completion status of the first PDU set can be further determined. Different retransmission enhancement schemes can then be executed based on the different initial transmission completion statuses of the first PDU set. For example, if all PDUs in the first PDU set have completed initial transmission, an autonomous retransmission scheme can be executed for the second PDU.

[0672] In one embodiment, performing an autonomous retransmission scheme for the second PDU includes retransmitting the second PDU.

[0673] 2) If there are PDUs in the first PDU set that have not been initially transmitted, then the polling enhancement scheme is triggered when transmitting the next PDU to be initially transmitted in the first PDU set.

[0674] In other words, if the remaining lifetime of the second PDU is less than or equal to the eleventh trigger duration threshold, and if all the first PDU sets have completed their initial transmission (i.e., there are still PDUs in the first PDU set that have not undergone initial transmission), then the polling enhancement scheme can be triggered when transmitting the next PDU in the first PDU set that is to be transmitted.

[0675] In one embodiment, triggering the polling enhancement scheme when transmitting the next PDU to be transmitted in the first PDU set includes: when transmitting the next PDU to be transmitted in the first PDU set, carrying polling indication information in the next PDU to be transmitted, for example, carrying P=1.

[0676] By triggering the polling enhancement scheme when transmitting the next PDU to be transmitted in the first PDU set, the number of PDUs that have been successfully received in the first PDU set can be queried based on the SR fed back by the receiver. Based on the reception ratio of the first PDU set after the initial transmission, it can be determined whether the retransmission enhancement scheme needs to be executed.

[0677] For example, if the reception ratio of the first PDU set after the initial transmission is greater than or equal to the content ratio information, the retransmission enhancement scheme may not be executed. If the reception ratio of the first PDU set after the second initial transmission is still less than the content ratio information, the initial transmission completion status of the first PDU set may be determined again, and the retransmission enhancement scheme may be executed according to the initial transmission completion status of the first PDU set.

[0678] S1703: If the reception ratio of the first PDU set is greater than or equal to the content ratio information, then other PDUs in the first PDU set will not be retransmitted or retransmitted.

[0679] Other PDUs refer to the PDUs in the first PDU set that are not the PDUs that have been successfully received.

[0680] In this embodiment, by determining the content ratio information and the reception ratio of the first PDU set, and not retransmitting or initially transmitting other PDUs in the first PDU set when the reception ratio of the first PDU set is greater than or equal to the content ratio information, system consumption can be saved and unnecessary data packets can be avoided. By implementing a retransmission enhancement scheme for specific PDUs in the first PDU set when the reception ratio of the first PDU set is less than the content ratio information, the timeliness of successful transmission of the first PDU set can be improved, thereby improving the timeliness and reliability of data transmission. Furthermore, by implementing different retransmission enhancement schemes based on the different initial transmission completion states of the first PDU set, the flexibility of implementing retransmission enhancement schemes can be further improved, unnecessary retransmissions can be avoided, and system consumption can be saved.

[0681] Figure 18 shows a schematic block diagram of a communication device provided in an embodiment of this application. The communication device 1800 can be a terminal device / network device, or a chip, chip system, or processor within the terminal device / network device that implements the above-described methods. This device can be used to implement the methods described in the above-described method embodiments; for details, please refer to the descriptions in the above-described method embodiments.

[0682] The communication device 1800 may include one or more processors 1810, which may also be referred to as processing units, and can implement certain control functions. The processor 1810 may be a general-purpose processor or a dedicated processor, such as a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, while the central processing unit can be used to control the communication device, execute software programs, and process data from the software programs.

[0683] In an alternative design, the processor 1810 may also store instructions and / or data that can be executed by the processor 1810 to cause the communication device 1800 to perform the methods described in the above method embodiments.

[0684] In another alternative design, the communication device 1800 may include a communication interface 1820 for implementing receiving and transmitting functions. For example, the communication interface 1820 may be a transceiver circuit, interface, interface circuit, or transceiver. The transceiver circuit, interface, interface circuit, or transceiver for implementing receiving and transmitting functions may be separate or integrated. The aforementioned transceiver circuit, interface, interface circuit, or transceiver may be used for reading and writing code / data, or it may be used for transmitting or relaying signals.

[0685] Optionally, the communication device 1800 may include one or more memories 1830, which may store instructions that can be executed on the processor 1810, causing the communication device 1800 to perform the methods described in the above method embodiments. Optionally, the memories 1830 may also store data. Optionally, the processor 1810 may also store instructions and / or data. The processor 1810 and the memories 1830 may be provided separately or integrated together.

[0686] It should be understood that, in one possible design, the steps in the method embodiments provided in this application can be implemented by integrated logic circuits in the processor's hardware or by instructions in software form. The steps of the method disclosed in the embodiments of this application can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules in the processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method. To avoid repetition, detailed descriptions are not provided here.

[0687] It should be noted that the processor in the embodiments of this application can be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiments can be completed by the integrated logic circuitry in the processor's hardware or by instructions in software form. The processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied as being executed by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor reads the information in the memory and, in conjunction with its hardware, completes the steps of the above methods.

[0688] It is understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0689] This application also provides a computer program product, which includes computer program code. When the computer program code is run on a computer, it causes the computer to execute the various steps or processes executed by the terminal device / network device in any of the above method embodiments.

[0690] This application also provides a computer-readable storage medium storing program code that, when run on a computer, causes the computer to execute the various steps or processes performed by the terminal device / network device in any of the above method embodiments.

[0691] This application also provides a communication device, including a processor and an interface, the interface being used to send and / or receive signals, causing the processor to execute the various steps or processes executed by the terminal device / network device in any of the above method embodiments.

[0692] The above-described device and method embodiments are completely corresponding, with corresponding modules or units performing corresponding steps. For example, a communication unit or communication interface performs the receiving or sending steps in the method embodiment, while other steps besides sending and receiving can be performed by a processing unit or processor.

[0693] In the embodiments of this application, the terms and English abbreviations are exemplary examples given for ease of description and should not be construed as limiting the application in any way. The embodiments of this application do not preclude the possibility of defining other terms that can achieve the same or similar functions in existing or future agreements.

[0694] As used in this specification, the terms "component," "module," "system," etc., are used to refer to computer-related entities, hardware, firmware, combinations of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, and / or a computer. As illustrated, applications running on computing devices and computing devices can both be components. One or more components may reside in a process and / or an execution thread, and components may be located on a single computer and / or distributed among two or more computers. Furthermore, these components can be executed from various computer-readable storage media on which various data structures are stored. Components can communicate, for example, via local and / or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system, and / or a network, such as the Internet interacting with other systems via signals).

[0695] Those skilled in the art will recognize that the various illustrative logical blocks and steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.

[0696] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be based on the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0697] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0698] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0699] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0700] In the above embodiments, the functions of each functional unit can be implemented entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions (programs). When the computer program instructions (programs) are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state disks, SSDs), etc.

[0701] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, essentially or in other words, the parts that contribute to the prior art, or parts of the technical solutions, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0702] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A retransmission enhancement method, characterized in that, Applied in a first device, the method includes: Determine the first piece of information; Based on the first information, the first retransmission enhancement scheme is executed. The first retransmission enhancement scheme is any one of the following: polling enhancement scheme, autonomous retransmission scheme, priority polling enhancement scheme, and priority autonomous retransmission scheme. The priority polling enhancement scheme refers to prioritizing the execution of the polling enhancement scheme and, if no status report is received when the triggering condition of the autonomous retransmission scheme is met, executing the autonomous retransmission scheme. The priority autonomous retransmission scheme refers to prioritizing the execution of the autonomous retransmission scheme and triggering the polling enhancement scheme while executing the autonomous retransmission scheme, or it refers to prioritizing the execution of the autonomous retransmission scheme and executing the polling enhancement scheme if no status report is received when the triggering conditions of the polling enhancement scheme are met.

2. The method as described in claim 1, characterized in that, The first information includes first indication information sent by the network device and / or the judgment information of the first device itself.

3. The method as described in claim 2, characterized in that, The first indication information is used to indicate whether a retransmission enhancement scheme is used, and / or to indicate the retransmission enhancement scheme that needs to be used.

4. The method as described in claim 3, characterized in that, The first indication information includes the retransmission enhancement scheme activation status or the retransmission enhancement scheme deactivation status. The retransmission enhancement scheme activation status includes one or more of the following: polling enhancement scheme activation status, autonomous retransmission activation status, priority polling enhancement scheme activation status, and priority retransmission enhancement scheme activation status. The activation status of the polling enhancement scheme is used to indicate that the polling enhancement scheme is activated; The autonomous retransmission activation status is used to indicate the activation of the autonomous retransmission scheme. The activation status of the priority polling enhancement scheme is used to indicate the activation of the priority polling enhancement scheme; The priority autonomous retransmission activation status is used to indicate the activation of the priority autonomous retransmission scheme.

5. The method according to any one of claims 1-4, characterized in that, The execution of the first retransmission enhancement scheme includes: When the first retransmission enhancement scheme includes a polling enhancement scheme, the polling enhancement scheme is triggered based on a first triggering condition; wherein, the first triggering condition includes at least one of the following triggering conditions: the remaining lifetime of the data packets in the transmission window is less than or equal to a certain duration threshold, the data packets in the transmission window are indicated as delayed critical data packets, the number of data protocol units (PDUs) or bytes sent reaches a certain threshold, the number of sequence numbers (SNs) sent reaches a certain threshold, the transmission buffer and / or retransmission buffer is empty, the polling retransmission timer times out, the polling retransmission timer times out and no status report is received, and it is triggered in the last transmission of the PDU set; When the first retransmission enhancement scheme includes an autonomous retransmission scheme, the autonomous retransmission scheme is triggered based on a second triggering condition; wherein, the second triggering condition includes at least one of the following triggering conditions: the remaining lifetime of the data packet in the transmission window is less than or equal to a certain duration threshold, triggering for a delay-critical data packet, triggering for a PDU whose importance in the PDU set meets the requirements, triggering for a PDU in an unknown state in the PDU set after the initial transmission of all PDUs in the PDU set is completed, triggering for a delay-critical data packet when the polling retransmission timer times out, the transmission gap or channel quality meets the requirements, and the data stream ends or the transmission window stops.

6. The method as described in claim 5, characterized in that, Compared with ordinary polling, the polling enhancement scheme satisfies at least one of the following conditions: subject to different prohibition timers, corresponding to different trigger condition parameters, allowing the receiving entity to handle the reassembly timer and / or prohibition timer in different ways, enhancing the retransmission procedure after receiving a status report based on polling enhancement, and stopping the polling enhancement of the corresponding Radio Link Control (RLC) entity when the packet delay budget (PDB) of the service data stream is reached. Compared with ordinary retransmission, the autonomous retransmission scheme satisfies at least one of the following conditions: the transmission priority of autonomous retransmission is higher than that of ordinary retransmission; transmission resources for autonomous retransmission are scheduled after all PDUs of a burst are transmitted; and autonomous retransmission of the corresponding RLC entity is stopped when the PDB of the service data stream is reached.

7. The method as described in claim 3 or 4, characterized in that, If the first indication information includes the retransmission enhancement scheme activation status, the first indication information also includes configuration information corresponding to the retransmission enhancement scheme activation status, and the configuration information includes parameters related to the triggering conditions of the retransmission enhancement scheme activated by the retransmission enhancement scheme activation status indication. The step of executing the first retransmission enhancement scheme based on the first information includes: The first retransmission enhancement scheme is triggered based on the activation status of the retransmission enhancement scheme and the configuration information.

8. The method as described in claim 7, characterized in that, When the retransmission enhancement scheme activation status indicates that the activated retransmission enhancement scheme includes the polling enhancement scheme, the configuration information includes first configuration information corresponding to the polling enhancement scheme. The first configuration information includes at least one of trigger duration threshold, trigger count threshold, trigger period, and sequence number period. When the retransmission enhancement scheme activation status indicates that the activated retransmission enhancement scheme includes the autonomous retransmission scheme, the configuration information includes second configuration information corresponding to the autonomous retransmission scheme. The second configuration information includes at least one of trigger duration threshold, trigger channel quality threshold, and trigger transmission gap length.

9. The method according to any one of claims 1-4, characterized in that, Before executing the first retransmission enhancement scheme based on the first information, the method further includes: Obtain configuration information of network device configuration, the configuration information including at least one trigger duration threshold, and a first timer and / or timing parameters of the first timer, the first timer being used to determine the remaining lifetime of the data packet; The step of executing the first retransmission enhancement scheme based on the first information includes: Based on the first information and the configuration information, the first retransmission enhancement scheme is triggered based on the remaining lifetime of the data packet.

10. The method as described in claim 9, characterized in that, The at least one trigger duration threshold includes a first trigger duration threshold, the first information being a first indication information configured by the network device, the first indication information being used to indicate whether to use a polling enhancement scheme or an autonomous retransmission scheme. The step of triggering the first retransmission enhancement scheme based on the remaining lifetime of the data packet according to the first information and the configuration information includes: When the first indication information indicates the use of the polling enhancement scheme, the polling enhancement scheme is triggered when the remaining lifetime of the first data packet is less than or equal to the first trigger duration threshold. The first data packet is a data packet that has been sent and whose reception status is unknown. The remaining lifetime of the first data packet is determined based on the timing duration of the first timer. When the first indication information indicates the use of the autonomous retransmission scheme, the autonomous retransmission scheme is triggered when the remaining lifetime of the first data packet is less than the first trigger duration threshold.

11. The method as described in claim 9, characterized in that, The at least one trigger duration threshold includes a second trigger duration threshold and a third trigger duration threshold, and the second trigger duration threshold is greater than the third trigger duration threshold. The first information is a first indication information configured by the network device. The first indication information is used to indicate whether to prioritize the use of the polling enhancement scheme or the autonomous retransmission scheme. The step of triggering the first retransmission enhancement scheme based on the first information and the at least one trigger duration threshold, according to the remaining lifetime of the data packet, includes: When the first indication information indicates the use of the priority polling enhancement scheme, the polling enhancement scheme is triggered when the remaining lifetime of the first data packet is less than or equal to the second trigger duration threshold; if no status report is received when the remaining lifetime of the first data packet is less than or equal to the third trigger duration threshold, the autonomous retransmission scheme is triggered, where the first data packet is a data packet that has been sent and whose reception status is unknown. When the first indication information indicates the use of the priority autonomous retransmission scheme, if the remaining lifetime of the first data packet is less than or equal to the second trigger duration threshold, the autonomous retransmission scheme is triggered, or the autonomous retransmission scheme and the polling enhancement scheme are triggered; if no status report is received when the remaining lifetime of the first data packet is less than or equal to the third trigger duration threshold, the polling enhancement scheme is triggered, or the autonomous retransmission scheme and the polling enhancement scheme are triggered.

12. The method as described in claim 9, characterized in that, The at least one trigger duration threshold includes a fourth trigger duration threshold and / or a fifth trigger duration threshold. The fourth trigger duration threshold is the trigger duration threshold for the polling enhancement scheme, and the fifth trigger duration threshold is the trigger duration threshold for the autonomous retransmission scheme. The first information is the first indication information configured by the network device, and the first indication information is used to indicate whether to use the retransmission enhancement scheme. The step of triggering the first retransmission enhancement scheme based on the first information and the at least one trigger duration threshold, according to the remaining lifetime of the data packet, includes: When the first indication information indicates the use of a retransmission enhancement scheme, the retransmission enhancement scheme corresponding to the trigger duration threshold is triggered based on the remaining lifetime of the data packet, according to the trigger duration threshold included in the at least one trigger duration threshold.

13. The method as described in claim 12, characterized in that, The step of triggering a retransmission enhancement scheme corresponding to the trigger duration threshold based on the remaining lifetime of the data packet, according to the trigger duration threshold included in the at least one trigger duration threshold, includes: If the at least one trigger duration threshold includes the fourth trigger duration threshold, then if the remaining lifetime of the first data packet is less than the fourth trigger duration threshold, the polling enhancement scheme is triggered, wherein the first data packet is a data packet that has been sent and whose reception status is unknown. If the at least one trigger duration threshold includes the fifth trigger duration threshold, then the autonomous retransmission scheme is triggered if the remaining lifetime of the first data packet is less than or equal to the fifth trigger duration threshold. If the at least one trigger duration threshold includes the fourth trigger duration threshold and the fifth trigger duration threshold, and the fourth trigger duration threshold is greater than the fifth trigger duration threshold, then the polling enhancement scheme is triggered if the remaining lifetime of the first data packet is less than or equal to the fourth trigger duration threshold; if no status report is received when the remaining lifetime of the first data packet is less than or equal to the fifth trigger duration threshold, then the autonomous retransmission scheme is triggered. If the at least one trigger duration threshold includes the fourth trigger duration threshold and the fifth trigger duration threshold, and the fourth trigger duration threshold is less than the fifth trigger duration threshold, then the autonomous retransmission scheme is triggered if the remaining lifetime of the first data packet is less than or equal to the fifth trigger duration threshold; if no status report is received when the remaining lifetime of the first data packet is less than or equal to the fourth trigger duration threshold, then the polling enhancement scheme is triggered.

14. The method as described in claim 9, characterized in that, The at least one trigger duration threshold includes multiple trigger duration thresholds. The first information is a first indication information configured by the network device. The first indication information is used to indicate whether to use the polling enhancement scheme, use the autonomous retransmission scheme, prioritize the use of the polling enhancement scheme, or prioritize the use of the autonomous retransmission scheme. The step of triggering the first retransmission enhancement scheme based on the first information and the at least one trigger duration threshold, according to the remaining lifetime of the data packet, includes: If the first indication information indicates the use of the polling enhancement scheme, then the polling enhancement scheme is triggered when the remaining lifetime of the first data packet is less than or equal to any one of the plurality of trigger duration thresholds, wherein the first data packet is a data packet that has been sent and whose reception status is unknown; If the first indication information indicates the use of the autonomous retransmission scheme, then the autonomous retransmission scheme is triggered when the remaining lifetime of the first data packet is less than or equal to any one of the plurality of trigger duration thresholds. If the first indication information indicates that the polling enhancement scheme should be used first, then the polling enhancement scheme is triggered when the remaining lifetime of the first data packet is less than or equal to the sixth triggering lifetime threshold among the plurality of triggering lifetime thresholds; if no status report is received when the remaining lifetime threshold of the first data packet is less than or equal to the seventh triggering lifetime threshold, then the autonomous retransmission scheme is triggered, wherein the seventh triggering lifetime threshold is the first triggering lifetime threshold among the plurality of triggering lifetime thresholds arranged in descending order after the sixth triggering lifetime threshold; If the first indication information indicates that the autonomous retransmission scheme should be used first, then when the remaining lifetime of the first data packet is less than or equal to the eighth trigger duration threshold among the plurality of trigger duration thresholds, the autonomous retransmission scheme, or the autonomous retransmission scheme and the polling enhancement scheme, are triggered; if the status report has not been received when the remaining lifetime threshold of the first data packet is less than or equal to the ninth trigger duration threshold, then the polling enhancement scheme, or the autonomous retransmission scheme and the polling enhancement scheme, are triggered, where the ninth trigger duration threshold is the first trigger duration threshold among the plurality of trigger duration thresholds arranged in descending order after the eighth trigger duration threshold.

15. The method according to any one of claims 10-14, characterized in that, The triggering of the polling enhancement scheme includes: Polling is triggered when the next data packet to be transmitted is transmitted, or when the first data packet is retransmitted; The triggering of the autonomous retransmission scheme includes: Retransmit the first data packet.

16. The method according to any one of claims 10-15, characterized in that, The method further includes: Upon receiving the first data packet, the first timer is started; The remaining lifespan of the first data packet is determined based on the duration of the first timer.

17. The method as described in claim 16, characterized in that, The step of starting a first timer upon receiving the first data packet includes: When the first timer is configured in the RLC entity of the first device, the first timer is started when the RLC entity receives the first data packet sent by the upper layer; wherein, the first timer is a new counter configured by the network device for the RLC entity; When the first timer is configured in the PDCP entity of the first device, the first counter is started when the PDCP entity receives the first data packet sent by the upper layer, or when the first data packet is sent to the RLC entity; wherein the first counter is a drop timer in the PDCP entity or a new counter configured by the network device for the PDCP entity.

18. The method according to any one of claims 1-17, characterized in that, After implementing the first retransmission enhancement scheme, the method further includes: If a second indication message is received from a network device, and the second indication message is used to indicate that the retransmission enhancement scheme is not used, then the execution of the first retransmission enhancement scheme is stopped. And / or, If the number of executions or the execution duration of the target retransmission enhancement scheme exceeds a first threshold, the execution of the target retransmission enhancement scheme is stopped. The target retransmission enhancement scheme is any retransmission enhancement scheme executed during the execution of the first retransmission enhancement scheme. The first threshold is a first duration threshold or a first number threshold, and the first threshold is configured by the network device. And / or, If the PDB of the business data stream expires, the first retransmission enhancement scheme executed in the corresponding RLC entity will be stopped.

19. The method as described in claim 1 or 2, characterized in that, The first information includes third indication information or content ratio information; The third indication information is used to indicate that the first data packet is a delayed critical data packet, and the first data packet is a data packet that has been sent but whose status is unknown; The content ratio information refers to the ratio between the minimum number of data packets required for the receiving end to successfully recover the data and the total number of data packets in the data.

20. The method as described in claim 19, characterized in that, The first information includes the third indication information, and the step of executing the first retransmission enhancement scheme based on the first information includes: If the third indication information is obtained before the first data packet is transmitted for the first time, then the polling enhancement scheme is triggered when the first data packet is transmitted for the first time. If the third indication information is obtained after the first data packet is transmitted for the first time, an autonomous retransmission scheme is executed for the first data packet.

21. The method as described in claim 20, characterized in that, After triggering the polling enhancement scheme when the first data is initially transmitted, the method further includes: If no status report is received before the remaining lifetime of the first data packet is less than or equal to the tenth trigger duration threshold, the autonomous retransmission scheme is executed for the first data packet, where the tenth trigger duration is configured by the network device. If the third indication information is obtained after the initial transmission of the first data packet, an autonomous retransmission scheme is executed for the first data packet, including: If the third indication information is obtained after the first data packet is initially transmitted, and the status report has not been received when the remaining lifetime of the first data packet is less than or equal to the tenth trigger duration threshold, the autonomous retransmission scheme is executed for the first data packet.

22. The method as described in claim 21, characterized in that, The first information includes the content ratio information, and the step of executing the first retransmission enhancement scheme based on the first information includes: If the reception ratio of the first PDU set is less than the content ratio information, the first retransmission enhancement scheme is executed on a specific PDU in the first PDU set, where the reception ratio refers to the ratio between the number of PDUs that have been successfully received in the first PDU set and the total number of PDUs.

23. The method as described in claim 22, characterized in that, The execution of the first retransmission enhancement scheme on specific PDUs in the first PDU set includes: If the remaining lifetime of the second PDU in the first PDU set is less than or equal to the eleventh trigger duration threshold, and all PDUs in the first PDU set have completed their initial transmission, then an autonomous retransmission scheme is executed for the second PDU, which is a PDU that has completed its initial transmission and whose reception status is unknown. If there are PDUs in the first PDU set that have not been initially transmitted, then the polling enhancement scheme is triggered when transmitting the next PDU to be initially transmitted in the first PDU set.

24. The method as described in claim 22 or 23, characterized in that, The method further includes: Obtain PDU set information, which is used to indicate individual PDUs belonging to the same PDU set; During PDU transmission, the number of PDUs that have been successfully received in the first PDU set is recorded based on the PDU set information to determine the reception ratio of the first PDU set.

25. The method as described in any one of claims 23 or 24, characterized in that, The content ratio information is obtained from the network device, and the eleventh trigger duration threshold is configured by the network device.

26. A retransmission enhancement method, characterized in that, When applied in network devices, the method includes: Send a first indication message to the first device, the first indication message being used to indicate whether to use a retransmission enhancement scheme, and / or to indicate the retransmission enhancement scheme that needs to be used.

27. The method as described in claim 26, characterized in that, If the first indication information includes the retransmission enhancement scheme activation status, the first indication information also includes configuration information corresponding to the retransmission enhancement scheme activation status. The configuration information includes parameters related to the triggering conditions of the retransmission enhancement scheme activated by the retransmission enhancement scheme activation status indication.

28. The method as described in claim 26, characterized in that, The method further includes: Configure at least one trigger duration threshold and a first timer and / or timing parameters of the first timer to the first device, wherein the timing duration of the first timer is used to determine the remaining lifetime of the data packet, so that the first device triggers the retransmission enhancement scheme to be executed based on the remaining lifetime of the data packet according to the first indication information, the at least one trigger duration threshold and the first timer.

29. The method as described in any one of claims 27-28, characterized in that, The method further includes: Configure a first threshold for the first device. The first threshold is either a first duration threshold or a first number threshold. The first duration threshold is used to indicate the maximum execution duration of the retransmission enhancement scheme executed by the first device, and the first number threshold is used to indicate the maximum number of times the retransmission enhancement scheme is executed by the first device.

30. The method as described in claim 29, characterized in that, The method further includes: Configure a second timer or a first counter to the first device. The second timer is used to count the execution time of the retransmission enhancement scheme to be executed, and the first counter is used to count the number of times the retransmission enhancement scheme to be executed is executed.

31. A retransmission enhancement method, characterized in that, When applied in network devices, the method includes: The first device sends content ratio information to the first device so that the first device can perform a retransmission enhancement scheme on the PDUs in the first PDU set based on the content ratio information. The content ratio information refers to the ratio between the minimum number of data packets required for the receiving end to successfully recover the data and the total number of data packets of the data.

32. The method as described in claim 31, characterized in that, The method further includes: Configure at least one trigger duration threshold for the first device so that the first device triggers a retransmission enhancement scheme based on the remaining lifetime of the PDUs in the first PDU set, according to the content ratio information and the at least one trigger duration threshold.

33. The method as described in claim 31 or 32, characterized in that, The method further includes: Configure a first timer and / or timing parameters of the first timer to the first device, wherein the timing duration of the first timer is used to determine the remaining lifetime of the data packet.

34. A communication device, characterized in that, The device includes a processor coupled to a memory storing a program or instructions for performing the method as described in any one of claims 1 to 25, or the memory storing a method for performing the method as described in any one of claims 26 to 33.

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