# US 10,484,150 B2 · Continuous retransmission in Wi-Fi systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,484,150 B2 - Document ID: US10484150B2 - Status: Granted - Kind: B2 - Application number: 15/341,301 - Filed: 2016-11-02 - Published: 2017-05-04 - Granted: 2019-11-19 - Earliest claimed: 2015-11-03 - Assignees: Apple Inc. - Applicants: Apple Inc. - Inventors: Yuchul Kim; Joonsuk Kim - Web page: https://patentgrep.com/patent/US10484150B2 ## CPC - H04L 1/189: {Transmission or retransmission of more than one copy of a message} - H04L 1/188: {Time-out mechanisms} - H04L 1/1887: {Scheduling and prioritising arrangements} - H04L 45/74: Address processing for routing - H04W 84/12: WLAN [Wireless Local Area Networks] - 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 This disclosure relates to performing retransmissions in a wireless communication system by a wireless device. A wireless device may receive a first transmission of a data frame according to a wireless communication technology. The wireless device may attempt to decode the data frame. It may be determined that attempting to decode the data frame is unsuccessful. A retransmission of the data frame may be received at a retransmission interval after the first transmission of the data frame. The retransmission interval may be less than a minimum interframe interval for contending for medium access for new transmissions according to the wireless communication technology. ## Claims ### Claim 1 An apparatus, comprising: a processing element configured to cause a wireless device to: receive a first transmission of a data frame according to a wireless communication technology; determine that the first transmission is a new transmission based at least in part on receiving the first transmission at least a minimum interframe interval after a previous transmission, wherein the minimum interframe interval is a minimum interframe interval for contending for medium access for new transmissions according to the wireless communication technology; attempt to decode the data frame; determine that the attempt to decode the data frame is unsuccessful; and based at least in part on determining that the attempt to decode the data frame is unsuccessful, receive a retransmission of the data frame at a retransmission interval after the first transmission of the data frame, wherein the retransmission interval is less than a minimum interframe interval for contending for medium access for new transmissions according to the wireless communication technology, and wherein the retransmission interval has a duration equal to a point coordination function (PCF) interframe space (PIFS); determine that the retransmission of the data frame is a retransmission of the data frame based at least in part on receiving the retransmission of the data frame at the retransmission interval that is after the first transmission of the data frame and equal to the PIFS and further based at least in part on recipient address information comprised in the data frame; and perform receive combining of the first transmission of the data frame and the retransmission of the data frame based at least in part on determining that the retransmission of the data frame is a retransmission of the data frame. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the retransmission interval is greater than an acknowledgement interval for transmitting acknowledgement messages in response to successfully decoded data frames according to the wireless communication technology. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein determining that the retransmission of the data frame is a retransmission of the data frame is further based at least in part on one or more of new packet indicator (NPI) information or initial transmission indicator (ITI) information comprised in the data frame. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the wireless communication technology comprises an Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless communication technology, wherein the minimum interframe interval comprises a distributed coordination function (DCF) interframe space (DIFS). ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the retransmission interval being less than the minimum interframe interval provides higher priority for retransmissions than for new transmissions. ### Claim 6 A wireless device, comprising: an antenna; a radio operably coupled to the antenna; and a processing element operably coupled to the radio; wherein the antenna, radio, and processing element are configured to: receive a data frame transmission according to a wireless communication technology; determine that the data frame transmission is a new transmission if the interval between receiving the data frame transmission and receiving a previous data frame transmission comprises at least a minimum interframe interval for contending for medium access for new transmissions according to the wireless communication technology; determine that the data frame transmission is a retransmission based at least in part on recipient address information comprised in the data frame and further based at least in part on the interval between receiving the data frame transmission and receiving the previous data frame transmission comprising a retransmission interval according to the wireless communication technology, wherein the retransmission interval has a duration equal to a point coordination function (PCF) interframe space (PIFS), wherein the minimum interframe interval for contending for medium access for new transmissions is greater than the retransmission interval; and perform receive combining of the data frame transmission and one or more corresponding previously received data frame transmissions based at least in part on determining that the data frame transmission is a retransmission. ### Claim 7 (depends on 6) The wireless device of claim 6, wherein the retransmission interval is greater than an acknowledgement interval according to the wireless communication technology, wherein according to the wireless communication technology the acknowledgement interval is for transmitting acknowledgement messages in response to successfully decoded data frames. ### Claim 8 (depends on 6) The wireless device of claim 6, wherein determining whether the data frame transmission is a new transmission or a retransmission is further based at least in part on one or more of new packet indicator (NPI) information or initial transmission indicator (ITI) information comprised in the data frame. ### Claim 9 (depends on 6) The wireless device of claim 6, wherein when the data frame transmission is determined to be a retransmission, the antenna, radio, and processing element are further configured to: determine whether the wireless device is an intended recipient of the retransmission based at least in part on recipient address information comprised in the data frame, wherein the recipient address information is comprised in physical layer (PHY) headers of the data frame. ### Claim 10 (depends on 1) The apparatus of claim 1, wherein the processing element is further configured to cause the wireless device to: attempt to decode the retransmission of the data frame; determine that the attempt to decode the retransmission of the data frame is unsuccessful; and based at least in part on determining that the attempt to decode the retransmission of the data frame is unsuccessful, receive a second retransmission of the data frame at the retransmission interval after receiving the retransmission. ### Claim 11 (depends on 6) The wireless device of claim 6, wherein the antenna, radio, and processing element are further configured to: attempt to decode the data frame transmission; determine that the attempt to decode the data frame is unsuccessful; and based at least in part on determining that the attempt to decode the data frame transmission is unsuccessful, receive a second data frame retransmission at the first retransmission interval after receiving the retransmission. ### Claim 12 A method for operating a wireless device, comprising: receiving a first transmission of a data frame according to a wireless communication technology; determining that the first transmission is a new transmission based at least in part on receiving the first transmission at least a minimum interframe interval after a previous transmission, wherein the minimum interframe interval is a minimum interframe interval for contending for medium access for new transmissions according to the wireless communication technology; attempting to decode the data frame; determining that the attempt to decode the data frame is unsuccessful; and based at least in part on determining that the attempt to decode the data frame is unsuccessful, receiving a retransmission of the data frame at a retransmission interval after the first transmission of the data frame, wherein the retransmission interval is less than the minimum interframe interval for contending for medium access for new transmissions according to the wireless communication technology, and wherein the retransmission interval has a duration equal to a point coordination function (PCF) interframe space (PIFS); determining that the retransmission of the data frame is a retransmission of the data frame based at least in part on receiving the retransmission of the data frame at the retransmission interval that is after the first transmission of the data frame and equal to the PIFS and further based at least in part on recipient address information comprised in the data frame; and performing receive combining of the first transmission of the data frame and the retransmission of the data frame based at least in part on determining that the retransmission of the data frame is a retransmission of the data frame. ### Claim 13 (depends on 12) The method of claim 12, wherein the retransmission interval is greater than an acknowledgement interval for transmitting acknowledgement messages in response to successfully decoded data frames according to the wireless communication technology. ### Claim 14 (depends on 12) The method of claim 12, wherein determining that the retransmission of the data frame is a retransmission of the data frame is further based at least in part on one or more of new packet indicator (NPI) information or initial transmission indicator (ITI) information comprised in the data frame. ### Claim 15 (depends on 12) The method of claim 12, wherein the wireless communication technology comprises an Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless communication technology, wherein the minimum interframe interval comprises a distributed coordination function (DCF) interframe space (DIFS). ### Claim 16 (depends on 12) The method of claim 12, wherein the retransmission interval being less than the minimum interframe interval provides higher priority for retransmissions than for new transmissions. ### Claim 17 (depends on 12) The method of claim 12, the method further comprising: attempting to decode the retransmission of the data frame; determining that the attempt to decode the retransmission of the data frame is unsuccessful; and based at least in part on determining that the attempt to decode the retransmission of the data frame is unsuccessful, receiving a second retransmission of the data frame at the first retransmission interval after receiving the retransmission. ### Claim 18 (depends on 1) The apparatus of claim 1, wherein when the data frame transmission is determined to be a retransmission, the processing element is further configured to cause the wireless device to: determine whether the wireless device is an intended recipient of the retransmission based at least in part on recipient address information comprised in the data frame, wherein the recipient address information is comprised in physical layer (PHY) headers of the data frame. ### Claim 19 (depends on 6) The wireless device of claim 6, wherein the wireless communication technology comprises an Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless communication technology, and wherein the minimum interframe interval comprises a distributed coordination function (DCF) interframe space (DIFS). ### Claim 20 (depends on 6) The wireless device of claim 6, wherein the retransmission interval being less than the minimum interframe interval provides higher priority for retransmissions than for new transmissions.