# US 11,121,829 B2 · Method and device for retransmission processing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,121,829 B2 - Document ID: US11121829B2 - Status: Granted - Kind: B2 - Application number: 16/342,411 - Filed: 2018-03-23 - Published: 2021-03-11 - Granted: 2021-09-14 - Earliest claimed: 2018-03-23 - Assignees: Guangdong Oppo Mobile Telecommunications Corp., Ltd. - Applicants: Guangdong Oppo Mobile Telecommunications Corp., Ltd. - Inventors: Cong Shi - Web page: https://patentgrep.com/patent/US11121829B2 ## CPC - H04L 1/188: {Time-out mechanisms} - H04L 1/1642: {Formats specially adapted for sequence numbers} - H04L 1/1685: {the supervisory signal being transmitted in response to a specific request, e.g. to a polling signal} - H04L 1/1835: {Buffer management} - H04L 1/1858: {Transmission or retransmission of more than one copy of acknowledgement message} - H04W 80/02: Data link layer protocols - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A method and device for retransmission processing are provided. The method includes that: a transmission side transmits a detection indication to a receiving side, the detection indication being used to indicate the receiving side to feed back a receiving state of multiple Acknowledged Mode Data (AMD) Protocol Data Units (PDU) sent by the transmission side; the transmission side receives a state report sent by the receiving side, the state report being used to indicate a receiving state of at least one AMD PDU in the multiple AMD PDUs; and if a Sequence Number (SN) of a first AMD PDU of the at least one AMD PDU is equal to a first value, the transmission side stops transmitting the detection indication for the multiple AMD PDUs to the receiving side, the first value being less than or equal to a maximum SN in the SNs of the multiple AMD PDUs. The method and device of the embodiments of the present application are advantageous in reducing unnecessary overhead. ## Claims ### Claim 1 A method for retransmission processing, comprising: transmitting, by a transmission side, a detection indication to a receiving side, the detection indication being used to indicate the receiving side to feed back a receiving state of a plurality of Acknowledged Mode Data (AMD) Protocol Data Units (PDU) sent by the transmission side; setting, by the transmission side, a first value to a value equal to a maximum Sequence Number (SN) in SNs of the plurality of AMD PDUs; receiving, by the transmission side, a state report sent by the receiving side, the state report being used to indicate a receiving state of at least one AMD PDU of the plurality of AMD PDUs; and responsive to that an SN of a first AMD PDU of the at least one AMD PDU is equal to the first value, stopping, by the transmission side, transmitting the detection indication for the plurality of AMD PDUs to the receiving side; wherein a packet header of a second AMD PDU of the plurality of AMD PDUs comprises the detection indication, and the method further comprises: after the transmission side delivers the second AMD PDU from a Radio Link Control (RLC) layer to a Media Access Control (MAC) layer, starting or restarting, by the transmission side, a detection retransmission timer; wherein the method further comprises: responsive to that the SN of none of the at least one AMD PDU is equal to the first value, continuing, by the transmission side, to transmit the detection indication for the plurality of AMD PDUs to the receiving side for a duration of the detection retransmission timer. ### Claim 2 (depends on 1) The method of claim 1, wherein stopping, by the transmission side, transmitting the detection indication for the plurality of AMD PDUs to the receiving side comprises: stopping and resetting, by the transmission side, the detection retransmission timer. ### Claim 3 (depends on 1) The method of claim 1, further comprising: responsive to the expiry of the detection retransmission timer, retransmitting, by the transmission side, all AMD PDUs, for each of which no state report is fed back, of the plurality of AMD PDUs according to the received state report. ### Claim 4 (depends on 3) The method of claim 3, wherein the AMD PDUs are transmitted by a first RLC layer of the transmission side, and retransmitting, by the transmission side, all AMD PDUs, for each of which no state report is fed back, of the plurality of AMD PDUs comprises: responsive to that a buffer of the first RLC layer is empty, or a Packet Data Convergence Protocol (PDCP) layer of the transmission side has no data transmission, or the PDCP layer has data transmission but the PDCP layer switches from the first RLC layer to a second RLC layer, retransmitting, by the transmission side, all AMD PDUs, for each of which no state report is fed back, of the plurality of AMD PDUs according to the received state report. ### Claim 5 (depends on 1) The method according to claim 1, wherein the transmission side is a terminal device or a network device. ### Claim 6 A device for retransmission processing, the device being a transmission side, the device comprising: a first transmitter, configured to transmit a detection indication to a receiving side, the detection indication being used to indicate the receiving side to feed back a receiving state of a plurality of Acknowledged Mode Data (AMD) Protocol Data Units (PDU) sent by the transmission side; a processor, configured to set a first value to a value equal to a maximum Sequence Number (SN) in SNs of the plurality of AMD PDUs; and a receiver, configured to receive a state report sent by the receiving side, the state report being used to indicate a receiving state of at least one AMD PDU of the plurality of AMD PDUs; wherein the processor; is further configured to stop, responsive to that an SN a first AMD PDU of the at least one AMD PDU is equal to the first value, transmitting the detection indication for the plurality of AMD PDUs to the receiving side, wherein a packet header of a second AMD PDU of the plurality of AMD PDUs comprises the detection indication, and the device further comprises: a detection retransmission timer, configured to be started or restarted, after the transmission side delivers the second AMD PDU from a Radio Link Control, RLC, layer to a Media Access Control, MAC, layer; wherein the first transmitter is further configured to: continue, responsive to that the SN of each of the at least one AMD PDU is not equal to the first value, to transmit the detection indication for the plurality of AMD PDUs to the receiving side for a duration of the detection retransmission timer. ### Claim 7 (depends on 6) The device of claim 6, wherein the processor is specifically configured to: stop and reset the detection retransmission timer. ### Claim 8 (depends on 6) The device of claim 6, further comprising: a second transmitter, configured to retransmit, responsive to the expiry of the detection retransmission timer, all AMD PDUs, for each of which no state report is fed back, of the plurality of AMD PDUs according to the received state report. ### Claim 9 (depends on 8) The device of claim 8, wherein the AMD PDUs are transmitted by a first RLC layer of the transmission side, and the second transmitter is specifically configured to: retransmit, responsive to that a buffer of the first RLC layer is empty, or a Packet Data Convergence Protocol (PDCP) layer of the transmission side has no data transmission, or the PDCP layer has data transmission but the PDCP layer switches from the first RLC layer to a second RLC layer, all AMD PDUs, for each of which no state report is fed back, of the plurality of AMD PDUs according to the received state report. ### Claim 10 (depends on 6) The device of claim 6, wherein the device is a terminal device or a network device. ### Claim 11 A non-transitory storage medium having stored thereon computer-executable instructions that when executed by a processor, cause the processor to perform a method, the method comprising: transmitting, by a transmission side, a detection indication to a receiving side, the detection indication being used to indicate the receiving side to feed back a receiving state of a plurality of Acknowledged Mode Data (AMD) Protocol Data Units (PDU) sent by the transmission side; setting, by the transmission side, a first value to a value equal to a maximum Sequence Number (SN) in SNs of the plurality of AMD PDUs; receiving, by the transmission side, a state report sent by the receiving side, the state report being used to indicate a receiving state of at least one AMD PDU of the plurality of AMD PDUs; and responsive to that an SN of a first AMD PDU of the at least one AMD PDU is equal to the first value, stopping, by the transmission side, transmitting the detection indication for the plurality of AMD PDUs to the receiving side; wherein a packet header of a second AMD PDU of the plurality of AMD PDUs comprises the detection indication, and the method further comprises: after the transmission side delivers the second AMD PDU from a Radio Link Control (RLC) layer to a Media Access Control (MAC) layer, starting or restarting, by the transmission side, a detection retransmission timer; wherein the method further comprises: responsive to that the SN of none of the at least one AMD PDU is equal to the first value, continuing, by the transmission side, to transmit the detection indication for the plurality of AMD PDUs to the receiving side for a duration of the detection retransmission timer.