Method and device for adjusting sending interval of 5G RLC (Radio Link Control) status report

Abstract

The invention discloses a method for adjusting a sending interval of a 5G RLC (Radio Link Control) status report. And when the RLC entity of the AM mode of the UE receives the polling bit with the value of 1 carried in the header of a certain downlink RLC PDU, if the serial number x of the downlink RLC PDU meets the condition that x is less than RXHigh Status or x is greater than or equal to RXNext + AMWindows Size, the RLC entity of the AM mode of the UE triggers an RLC state report. The RLC entity of the AM mode of the UE judges whether the status report prohibition timer is in a running state at present; and if RXNext < = the sequence number of the downlink RLC PDU currently received by the UE is less than ACKSN and the UE receives all downlink RLC PDUs in the interval, the UE stops the timing of the state report prohibition timer and performs zero clearing. And if not, the RLC entity of the AM mode of the UE performs RLC state report assembly and transmission in the next first uplink transmission opportunity. According to the invention, for the state report for sending the ACK SN, the state report prohibition timer is not started, and then the state report possibly carrying the NACK SN next time can be sent out in time, so that the time delay of processing a service data packet by the UE is reduced.

Description

Technical Field

[0001] The present application relates to a mobile communication technology, and in particular to a method for dynamically adjusting the RLC (Radio link control) status report sending interval in 5G communication technology. Background Art

[0002] In 5G mobile communication technology, the RLC layer provides three different transmission modes, namely transparent mode (TM), unconfirmed mode (UM), and confirmed mode (AM). Confirmed mode means that after the sender sends the data, it needs to wait for the confirmation information from the receiver. After receiving the data, the receiver needs to send a confirmation message to the sender to inform whether the data is received correctly. After the sender receives the confirmation message, if the confirmation message records that the receiver failed to receive the data correctly, the sender needs to resend the data indicating the reception failure in the confirmation message.

[0003] In 5G mobile communication technology, the AM-mode RLC entity of the UE (user equipment) uses a reassembly timer (t-Reassembly) to measure the maximum waiting time interval for retransmission of downlink packet loss HARQ (Hybrid automatic repeat request). If the reassembly timer times out, it means that the UE can no longer passively wait for the base station HARQ to retransmit one or more lost RLC PDUs (Protocol Data Units). The UE needs to actively send an RLC status report (which carries a non-confirmed sequence number) to notify the base station. The AM-mode RLC entity of the base station will perform ARQ (automatic repeat request) retransmission of the lost RLC PDU according to the RLC status report. The non-confirmed sequence number (NACK SN) refers to the sequence number of the RLC PDU that the receiving end has not received. From the UE's perspective, the UE's active actions should be as early as possible, so that the AM-mode RLC entity of the base station can prepare ARQ to retransmit the lost RLC PDU to the UE in time. The 5G mobile communication protocol also stipulates that the UE's AM mode RLC entity uses the status report prohibition timer (t-StatusProhibit) to measure the minimum time interval for the UE to send RLC status reports to the base station. This means that although the reassembly timer has timed out, the status report prohibition timer may still be running, resulting in the RLC status report carrying the unconfirmed sequence number needing to be delayed until the status report prohibition timer times out before it can be sent.

[0004] As mentioned above, the time interval for the UE to send the RLC status report to the base station is controlled by the reassembly timer and the status report prohibition timer. If the base station does not configure the status report prohibition timer, that is, the UE does not start the status report prohibition timer, although the lost RLC PDU can be temporarily retransmitted through the base station, the RLC status report loses the control of the time interval, and the RLC status report triggers the uplink SR (Scheduling Request) to apply for scheduling resources and the base station downlink RLC ARQ has air interface delays, which may cause the next RLC status report to still carry the same non-confirmed sequence number notification to the base station, causing unnecessary ARQ retransmissions by the base station and increasing the air interface downlink load. If the base station adjusts the time configuration of the reassembly timer and the status report prohibition timer, so that the timing duration of the latter status report prohibition timer ≤ the timing duration of the reassembly timer, it is still not feasible. Because there is another way to trigger the RLC status report for downlink data, that is, the UE receives the RLC PDU with the polling bit set to 1 sent by the base station, which makes the relative size adjustment of the two timer durations uncontrollable. The polling bit is a mechanism for the base station to actively poll the UE: if it is set to 1 (binary number), it indicates that the base station requests the UE to send an RLC status report; if it is set to 0 (binary number), it indicates that the base station does not request the UE to send an RLC status report. Summary of the invention

[0005] The technical problem to be solved by the present application is how to overcome the problem of the UE sending a RLC status report carrying a non-confirmed sequence number slowly due to the existence of a status report prohibition timer, and reduce the delay of the UE in processing service data packets.

[0006] In order to solve the above technical problems, the present application proposes a method for adjusting the 5G RLC status report sending interval, comprising the following steps. Step S11: When the AM mode RLC entity of the UE receives a polling bit with a value of 1 in the header of a downlink RLC PDU, if the sequence number x of the downlink RLC PDU satisfies x<RX_Highest_Status or x≥RX_Next+AM_Window_Size, the AM mode RLC entity of the UE triggers the RLC status report. Step S12: The AM mode RLC entity of the UE determines whether the status report prohibition timer is currently in the running state; if yes, enter step S13; if not, enter step S14. Step S13: If RX_Next≤the sequence number of the downlink RLC PDU currently received by the UE<ACK_SN and the UE has received all downlink RLC PDUs in the interval, the UE stops the timing of the status report prohibition timer and clears it to zero, and then enters step S14. Step S14: In the next first uplink transmission opportunity, the AM mode RLC entity of the UE assembles and sends the RLC status report.

[0007] Furthermore, in step S1, if the sequence number x of the downlink RLC PDU does not satisfy x<RX_Highest_Status and does not satisfy x≥RX_Next+AM_Window_Size, the UE's AM mode RLC entity continues to receive the downlink RLC PDU, and when the received downlink RLC PDU meets any one of the two trigger conditions, the UE's AM mode RLC entity triggers the RLC status report.

[0008] Furthermore, in step S1, if the current UE has not lost the downlink RLC PDU, the triggered RLC status report does not carry the unconfirmed sequence number; if the current UE has lost the downlink RLC PDU, the triggered RLC status report carries the unconfirmed sequence number.

[0009] Furthermore, in step S3, if the sequence number of the downlink RLC PDU currently received by the UE is less than RX_Next or the sequence number of the downlink RLC PDU currently received by the UE is greater than ACK_SN, the process returns to step S11.

[0010] Furthermore, in step S4, if the assembled RLC status report carries a confirmed sequence number, the UE does not start the status report prohibit timer; if the assembled RLC status report carries a non-confirmed sequence number, the UE starts the status report prohibit timer from zero.

[0011] The present application also proposes another method for adjusting the 5G RLC status report sending interval, comprising the following steps. Step S21: Once the UE's AM mode RLC entity detects that the received downlink RLC PDU is lost, it starts the reassembly timer, and triggers the RLC status report carrying the unconfirmed sequence number after the reassembly timer times out. If the previous RLC status report generated by the UE's AM mode RLC entity is an RLC status report carrying a confirmed sequence number, proceed to step S22. If the previous RLC status report generated by the UE's AM mode RLC entity is an RLC status report carrying an unconfirmed sequence number, proceed to step S23. Step S22: The UE's AM mode RLC entity stops the status report prohibition timer, and immediately assembles and sends the RLC status report carrying the unconfirmed sequence number in the next first uplink transmission opportunity; then the UE's AM mode RLC entity starts the status report prohibition timer. Step S23: After waiting for the status report prohibition timer to time out, the UE's AM mode RLC entity assembles and sends the RLC status report carrying the unconfirmed sequence number.

[0012] The present application also proposes a device for adjusting the 5G RLC status report sending interval, including an RLC status report triggering unit, a status report prohibition timer state detection unit, a status report prohibition timer clearing unit, and an RLC status report assembly sending unit. The RLC status report triggering unit is used to trigger the RLC status report when the RLC entity in the AM mode of the UE receives a polling bit with a value of 1 in the header of a downlink RLC PDU, if the sequence number x of the downlink RLC PDU satisfies x<RX_Highest_Status or x≥RX_Next+AM_Window_Size. The status report prohibition timer state detection unit is used to determine whether the status report prohibition timer is currently in a running state; if so, it is transferred to the status report prohibition timer clearing unit for processing; if not, it is transferred to the RLC status report assembly sending unit for processing. The status report prohibition timer clearing unit is used to stop the timing of the status report prohibition timer and clear it when RX_Next≤the sequence number of the downlink RLC PDU currently received by the UE<ACK_SN and the UE has received all downlink RLC PDUs in the interval, and then transfer it to the RLC status report assembly sending unit for processing. The RLC status report assembling and sending unit is used for the RLC entity in the AM mode of the UE to assemble and send the RLC status report in the next first uplink sending opportunity.

[0013] The present application also proposes another device for adjusting the 5G RLC status report sending interval, including a reassembly timer starting unit, an RLC status report first processing unit, and an RLC status report second processing unit. The reassembly timer starting unit is used to start the reassembly timer once the UE's AM mode RLC entity detects that the received downlink RLC PDU is lost, and triggers an RLC status report carrying an unconfirmed sequence number after the reassembly timer times out. The RLC status report first processing unit is used to stop the status report prohibition timer of the UE's AM mode RLC entity when the previous RLC status report generated by the UE's AM mode RLC entity is an RLC status report carrying a confirmed sequence number, and immediately assemble and send an RLC status report carrying an unconfirmed sequence number in the next first uplink transmission opportunity; then the UE's AM mode RLC entity starts the status report prohibition timer. The RLC status report second processing unit is used for assembling and sending the RLC status report carrying the unconfirmed sequence number by the RLC entity in the AM mode of the UE after the waiting status report prohibition timer times out when the RLC status report previously generated by the RLC entity in the AM mode of the UE is an RLC status report carrying an unconfirmed sequence number.

[0014] The technical effect achieved by the present application is to prevent the status report of UE sending ACK SN from affecting the timeliness of the subsequent status report of UE sending NACKSN, thereby reducing the delay of UE processing service data packets. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a flow chart of embodiment 1 of the method for adjusting the 5G RLC status report sending interval proposed in this application.

[0016] Figure 2 This is a flow chart of Example 2 of the method for adjusting the 5G RLC status report sending interval proposed in this application.

[0017] Figure 3 This is a structural diagram of embodiment 1 of the device for adjusting the 5G RLC status report sending interval proposed in the present application.

[0018] Figure 4 This is a structural diagram of embodiment 2 of the device for adjusting the 5G RLC status report sending interval proposed in this application.

[0019] Explanation of the reference numerals in the figure: RLC status report triggering unit 11, status report prohibition timer status detecting unit 12, status report prohibition timer clearing unit 13, RLC status report assembling and sending unit 14, reassembly timer starting unit 21, RLC status report first processing unit 22, RLC status report second processing unit 23. DETAILED DESCRIPTION

[0020] Normally, when the number of RLC PDUs sent by the AM-mode RLC entity of the base station reaches pollPDU, or the amount of data sent by the RLC PDU reaches pollByte, polling is triggered, that is, the base station carries a polling bit with a value of 1 in the header of the downlink RLC PDU sent. pollPDU is used to indicate how many RLC PDUs the AM-mode RLC entity of the base station adds a polling bit with a value of 1 for each RLC PDU sent. pollByte is used to indicate how many bytes (the number of bytes of the RLC PDU sent) the AM-mode RLC entity of the base station adds a polling bit with a value of 1 for each byte sent. When the AM-mode RLC entity of the UE receives a polling bit with a value of 1 in the header of a downlink RLC PDU, if the sequence number x of the downlink RLC PDU satisfies x<RX_Highest_Status or x≥RX_Next+AM_Window_Size, the AM-mode RLC entity of the UE triggers an RLC status report. RX_Highest_Status indicates the maximum possible ACK_SN value in the RLC status report; ACK_SN indicates the sequence number of the next RLC SDU (Service Data Unit) that was not received and not indicated as lost in the RLC status report. RX_Next indicates the next sequence number of the sequence number of the last completely received RLC SDU received by the RLC entity at the receiving end. AM_Window_Size indicates the RLC receiving window size at the receiving end.

[0021] See also Figure 1 , Embodiment 1 of the method for adjusting the 5G RLC status report sending interval proposed in the present application includes the following steps, for the situation where the RLC status report is triggered by base station polling.

[0022] Step S11: When the AM-mode RLC entity of the UE receives a polling bit with a value of 1 in the header of a downlink RLC PDU, if the sequence number x of the downlink RLC PDU satisfies x<RX_Highest_Status or x≥RX_Next+AM_Window_Size, the AM-mode RLC entity of the UE triggers an RLC status report. If the sequence number x of the downlink RLC PDU does not satisfy any of the two aforementioned triggering conditions, the AM-mode RLC entity of the UE continues to receive the downlink RLC PDU, and when the received downlink RLC PDU satisfies any of the two aforementioned triggering conditions, the AM-mode RLC entity of the UE triggers an RLC status report. If the current UE has not lost the downlink RLC PDU, the triggered RLC status report does not carry a non-confirmed sequence number. If the current UE has lost a downlink RLC PDU, the triggered RLC status report carries a non-confirmed sequence number.

[0023] Step S12: The RLC entity in the AM mode of the UE determines whether the status report prohibition timer is currently in the running state. If yes, proceed to step S13. If not, proceed to step S14.

[0024] Step S13: If RX_Next≤the sequence number of the downlink RLC PDU currently received by the UE<ACK_SN and the UE has received all downlink RLC PDUs in the interval (from RX_Next to ACK_SN), it means that the retransmission requests of all downlink RLC PDUs corresponding to the unreceived sequence numbers recorded in the previous RLC status report carrying the unconfirmed sequence number have been met. At this time, the UE stops the timing of the status report prohibition timer and resets it to zero, and then enters step S14. This allows the UE to send out the RLC status report carrying the unconfirmed sequence number in a timely manner after triggering it later, reducing the reordering waiting delay.

[0025] If the sequence number of the downlink RLC PDU currently received by the UE is less than RX_Next or the sequence number of the downlink RLC PDU currently received by the UE is greater than ACK_SN, the process returns to step S11.

[0026] Step S14: In the next first uplink transmission opportunity, the AM mode RLC entity of the UE assembles and sends the RLC status report. If the assembled RLC status report carries a confirmed sequence number, the UE does not start the status report prohibit timer. The confirmed sequence number (ACK SN) refers to the sequence number of the received RLC PDU. If the assembled RLC status report carries a non-confirmed sequence number, the UE starts the status report prohibit timer from zero. The non-confirmed sequence number (NACK SN) refers to the sequence number of the RLC PDU that has not been received.

[0027] The present application considers that the situation in which the base station polls to trigger the RLC status report already includes the restriction control on the triggering of the RLC status report by both the sending end (base station) and the receiving end (UE). The restriction control on the triggering of the RLC status report by the sending end refers to pollPDU and pollByte. The restriction control on the triggering of the RLC status report by the receiving end refers to the two triggering conditions recorded in step S11. Therefore, in the first embodiment of the present application, for the triggering of the RLC status report carrying a confirmed sequence number (i.e., not carrying an unconfirmed sequence number), the status report prohibition timer is no longer started; for the triggering of the RLC status report carrying an unconfirmed sequence number, the processing method will be consistent with the RLC status report carrying an unconfirmed sequence number triggered by the timeout of the reorganization timer.

[0028] See also Figure 2 Embodiment 2 of the method for adjusting the 5G RLC status report sending interval proposed in the present application includes the following steps, for the situation where the reorganization timer times out and triggers an RLC status report carrying a non-confirmed sequence number.

[0029] Step S21: Once the AM mode RLC entity of the UE detects that the received downlink RLC PDU is lost, it starts a reassembly timer. After the reassembly timer times out, it triggers an RLC status report carrying a non-confirmed sequence number.

[0030] If the previous RLC status report generated by the RLC entity in the AM mode of the UE is an RLC status report carrying a confirmed sequence number, the process goes to step S22.

[0031] If the previous RLC status report generated by the RLC entity in the AM mode of the UE is an RLC status report carrying an unconfirmed sequence number, the process goes to step S23.

[0032] Step S22: The AM mode RLC entity of the UE stops the status report prohibit timer, and immediately assembles and sends the RLC status report carrying the unconfirmed sequence number in the next first uplink transmission opportunity. Then the AM mode RLC entity of the UE starts the status report prohibit timer.

[0033] Step S23: After the waiting status report prohibition timer times out (stops running), the AM mode RLC entity of the UE assembles and sends an RLC status report carrying a non-confirmed sequence number.

[0034] The above two embodiments start from two scenarios of triggering RLC status reporting, and jointly explain the method of adjusting the RLC status reporting interval.

[0035] See also Figure 3, an embodiment 1 of the device for adjusting the 5G RLC status report sending interval proposed in the present application includes an RLC status report triggering unit 11, a status report prohibition timer status detection unit 12, a status report prohibition timer clearing unit 13, and an RLC status report assembly sending unit 14. Figure 3 The device shown corresponds to Figure 1 The method shown is for the situation where base station polling triggers RLC status reporting.

[0036] The RLC status report triggering unit 11 is used to trigger an RLC status report when the AM mode RLC entity of the UE receives a polling bit with a value of 1 in the header of a downlink RLC PDU, if the sequence number x of the downlink RLC PDU satisfies x<RX_Highest_Status or x≥RX_Next+AM_Window_Size.

[0037] The status report prohibit timer state detection unit 12 is used to determine whether the status report prohibit timer is currently in the running state. If yes, it is transferred to the status report prohibit timer clearing unit 13 for processing. If not, it is transferred to the RLC status report assembly and sending unit 14 for processing.

[0038] The status report prohibit timer clearing unit 13 is used to stop the timing of the status report prohibit timer and clear it when RX_Next≤the sequence number of the downlink RLC PDU currently received by the UE<ACK_SN and the UE has received all downlink RLC PDUs in this interval, and then transfer it to the RLC status report assembly and sending unit 14 for processing.

[0039] The RLC status report assembly and transmission unit 14 is used for the UE's AM mode RLC entity to assemble and transmit the RLC status report in the next first uplink transmission opportunity. If the assembled RLC status report carries a confirmed sequence number, the UE does not start the status report prohibition timer. If the assembled RLC status report carries an unconfirmed sequence number, the UE starts the status report prohibition timer from zero.

[0040] See also Figure 4 , Embodiment 2 of the device for adjusting the 5G RLC status report sending interval proposed in the present application includes a reorganization timer starting unit 21, an RLC status report first processing unit 22, and an RLC status report second processing unit 23. Figure 4 The device shown corresponds to Figure 2 The method shown is for the situation where the reassembly timer times out and triggers an RLC status report carrying a non-confirmed sequence number.

[0041] The reassembly timer start unit 21 is used to start the reassembly timer once the RLC entity in the AM mode of the UE detects that the received downlink RLC PDU is lost. After the reassembly timer times out, an RLC status report carrying a non-confirmed sequence number is triggered.

[0042] The RLC status report first processing unit 22 is used for, when the previous RLC status report generated by the UE's AM mode RLC entity is an RLC status report carrying a confirmed sequence number, the UE's AM mode RLC entity stops the status report prohibition timer, and in the next first uplink transmission opportunity, immediately assembles and transmits an RLC status report carrying a non-confirmed sequence number. Then, the UE's AM mode RLC entity starts the status report prohibition timer.

[0043] The RLC status report second processing unit 23 is used for assembling and sending an RLC status report carrying an unconfirmed sequence number by the RLC entity in the AM mode of the UE after the waiting status report prohibition timer times out when the previous RLC status report generated by the RLC entity in the AM mode of the UE is an RLC status report carrying an unconfirmed sequence number.

[0044] The existing RLC protocol will uniformly start the status report prohibition timer after sending the current RLC status report, and will allow the next RLC status report to be sent after the timeout. This application will not start the status report prohibition timer for sending the status report of ACK SN, so as to send the status report that may carry NACK SN in time next time, and reduce the delay of UE processing service data packets.

[0045] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should all be included in the protection scope of the present application.

Claims

1. A method for adjusting a 5G RLC status report transmission interval, characterized in that: The method comprises the following steps: Step S11: When the AM mode RLC entity of the UE receives a polling bit with a value of 1 in the header of a downlink RLC PDU, if the sequence number x of the downlink RLC PDU satisfies x<RX_Highest_Status or x≥RX_Next+AM_Window_Size, the AM mode RLC entity of the UE triggers an RLC status report; Step S12: The RLC entity in the AM mode of the UE determines whether the status report prohibition timer is currently in a running state; If yes, go to step S13; if no, go to step S14; Step S13: If RX_Next≤the sequence number of the downlink RLC PDU currently received by the UE<ACK_SN and the UE has received all downlink RLC PDUs in the interval, the UE stops timing the status report prohibit timer and resets it to zero, and then proceeds to step S14; Step S14: In the next first uplink transmission opportunity, the AM mode RLC entity of the UE assembles and transmits the RLC status report.

2. The method for adjusting the 5G RLC status report sending interval according to claim 1, characterized in that: In the step S1, if the sequence number x of the downlink RLC PDU does not satisfy x<RX_Highest_Status and does not satisfy x≥RX_Next+AM_Window_Size, the UE's AM mode RLC entity continues to receive the downlink RLC PDU, and when the received downlink RLC PDU meets any one of the two trigger conditions, the UE's AM mode RLC entity triggers the RLC status report.

3. The method for adjusting the 5G RLC status report sending interval according to claim 1 or 2, characterized in that: In the step S1, if the current UE does not lose the downlink RLC PDU, the triggered RLC status report does not carry the unconfirmed sequence number; If the current UE has lost downlink RLC PDU, the triggered RLC status report carries the unconfirmed sequence number.

4. The method for adjusting the 5G RLC status report sending interval according to claim 1, characterized in that: In the step S3, if the sequence number of the downlink RLC PDU currently received by the UE is less than RX_Next or the sequence number of the downlink RLC PDU currently received by the UE is greater than ACK_SN, the process returns to step S11.

5. The method for adjusting the 5G RLC status report sending interval according to claim 1, characterized in that: In step S4, if the assembled RLC status report carries a confirmed sequence number, the UE does not start the status report prohibit timer; if the assembled RLC status report carries an unconfirmed sequence number, the UE starts the status report prohibit timer from zero.

6. A method for adjusting a 5G RLC status report transmission interval, characterized in that: The method comprises the following steps: Step S21: Once the AM mode RLC entity of the UE detects that the received downlink RLC PDU is lost, it starts a reassembly timer, and triggers an RLC status report carrying a non-confirmed sequence number after the reassembly timer times out; If the previous RLC status report generated by the RLC entity in the AM mode of the UE is an RLC status report carrying a confirmed sequence number, proceed to step S22; If the previous RLC status report generated by the RLC entity in the AM mode of the UE is an RLC status report carrying an unconfirmed sequence number, proceed to step S23; Step S22: the RLC entity in the AM mode of the UE stops the status report prohibition timer, and immediately assembles and sends the RLC status report carrying the unconfirmed sequence number in the next first uplink transmission opportunity; then the RLC entity in the AM mode of the UE starts the status report prohibition timer; Step S23: After the waiting status report prohibition timer times out, the AM mode RLC entity of the UE assembles and sends an RLC status report carrying a non-confirmed sequence number.

7. A device for adjusting a 5G RLC status report transmission interval, characterized in that: It includes an RLC status report triggering unit, a status report prohibition timer status detection unit, a status report prohibition timer clearing unit, and an RLC status report assembling and sending unit; The RLC status report triggering unit is used to trigger an RLC status report when the RLC entity in the AM mode of the UE receives a polling bit with a value of 1 in the header of a downlink RLC PDU, if the sequence number x of the downlink RLC PDU satisfies x<RX_Highest_Status or x≥RX_Next+AM_Window_Size; The status report prohibit timer status detection unit is used to determine whether the status report prohibit timer is currently in a running state; If yes, it is transferred to the status report prohibition timer clearing unit for processing; if no, it is transferred to the RLC status report assembly and sending unit for processing; The status report prohibit timer clearing unit is used for, when RX_Next≤the sequence number of the downlink RLC PDU currently received by the UE<ACK_SN and the UE has received all the downlink RLC PDUs in the interval, the UE stops timing the status report prohibit timer and clears it, and then transfers it to the RLC status report assembly and sending unit for processing; The RLC status report assembling and sending unit is used for the RLC entity in the AM mode of the UE to assemble and send the RLC status report in the next first uplink sending opportunity.

8. A device for adjusting a 5G RLC status report transmission interval, characterized in that: It includes a reorganization timer start unit, an RLC status report first processing unit, and an RLC status report second processing unit; The reassembly timer start unit is used to start the reassembly timer once the RLC entity in the AM mode of the UE detects that the received downlink RLC PDU is lost, and trigger an RLC status report carrying a non-confirmed sequence number after the reassembly timer times out; The RLC status report first processing unit is used for, when the previous RLC status report generated by the RLC entity in the AM mode of the UE is an RLC status report carrying a confirmed sequence number, the RLC entity in the AM mode of the UE stops the status report prohibition timer, and immediately assembles and sends the RLC status report carrying a non-confirmed sequence number in the next first uplink transmission opportunity; then the RLC entity in the AM mode of the UE starts the status report prohibition timer; The RLC status report second processing unit is used for assembling and sending the RLC status report carrying the unconfirmed sequence number by the RLC entity in the AM mode of the UE after the waiting status report prohibition timer times out when the RLC status report previously generated by the RLC entity in the AM mode of the UE is an RLC status report carrying an unconfirmed sequence number.

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