# US 11,451,341 B2 · Hybrid automatic repeat request (HARQ) in a wireless local area network (WLAN) > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,451,341 B2 - Document ID: US11451341B2 - Status: Granted - Kind: B2 - Application number: 16/917,605 - Filed: 2020-06-30 - Published: 2021-01-07 - Granted: 2022-09-20 - Earliest claimed: 2019-07-01 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Alfred Asterjadhi; George Cherian; Abhishek Pramod Patil; Lochan Verma; Jialing Li Chen; Stephen Jay Shellhammer; Dung Ngoc Doan; Bin Tian - Web page: https://patentgrep.com/patent/US11451341B2 ## CPC - H04L 1/1812: Hybrid protocols; Hybrid automatic repeat request [HARQ] - H04L 1/1896: {ARQ related signaling} - H04L 1/1614: {using bitmaps} - H04L 1/1621: {Group acknowledgement, i.e. the acknowledgement message defining a range of identifiers, e.g. of sequence numbers} - H04L 1/1819: {with retransmission of additional or different redundancy} - H04L 1/1825: Adaptation of specific ARQ protocol parameters according to transmission conditions - H04L 5/0055: {Physical resource allocation for ACK/NACK (for physical mapping arrangements in ARQ protocols H04L1/1861)} - H04W 74/0816: with collision avoidance - H04W 80/02: Data link layer protocols - H04L 5/0046: {Determination of the number of bits transmitted on different sub-channels} - 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 provides systems, methods, and apparatus, including computer programs encoded on computer-readable media, for implementing a hybrid automatic repeat request (HARQ) protocol in a wireless local area network (WLAN). In some aspects, a first WLAN device may transmit a first HARQ frame to a second WLAN device. The first WLAN device may determine whether a first feedback message received from the second WLAN device includes HARQ acknowledgement information or non-HARQ acknowledgment information. The first feedback message may be a HARQ Block Acknowledgement (H-BA) message having a multi-station Block ACK (M-BA) frame format that includes HARQ acknowledgment information. The first WLAN device may transmit a second HARQ frame to the second WLAN device in response to determining the first feedback message includes the HARQ acknowledgment information. The first WLAN device may transmit a non-HARQ frame in response to determining the first feedback message includes non-HARQ acknowledgement information. ## Claims ### Claim 1 A method performed by an apparatus of a first wireless local area network (WLAN) device for implementing a hybrid automatic repeat request (HARQ) protocol, comprising: transmitting a first HARQ frame to a second WLAN device; determining whether a first feedback message is received from the second WLAN device; responsive to receiving the first feedback message, determining whether the first feedback message includes HARQ acknowledgement information or non-HARQ acknowledgment information; and transmitting a second frame to the second WLAN device, the second frame being a second HARQ frame if the first feedback message includes the HARQ acknowledgement information or an automatic repeat request (ARQ) frame if the first feedback message includes the non-HARQ acknowledgement information. ### Claim 2 (depends on 1) The method of claim 1, wherein the first feedback message is a HARQ Block Acknowledgement (H-BA) message, the H-BA message including the HARQ acknowledgment information, and the HARQ acknowledgement information including one or more bitmaps. ### Claim 3 (depends on 2) The method of claim 2, wherein the one or more bitmaps of the H-BA message include at least one of: one or more codeword-level bitmaps; and one or more media access control protocol data units (MPDU)-level bitmaps. ### Claim 4 (depends on 3) The method of claim 3, wherein: the one or more codeword-level bitmaps provide a receive status of codewords associated with the first HARQ frame; and the one or more MPDU-level bitmaps provide a receive status of MPDUs. ### Claim 5 (depends on 3) The method of claim 3, wherein codewords of each of the one or more codeword-level bitmaps are identified by one or more starting codeword indexes. ### Claim 6 (depends on 3) The method of claim 3, wherein the one or more codeword-level bitmaps identify one or more groups of codewords. ### Claim 7 (depends on 2) The method of claim 2, wherein transmitting the second frame to the second WLAN device is based, at least in part, on the one or more bitmaps included in the H-BA message. ### Claim 8 (depends on 1) The method of claim 1, wherein the first feedback message is an H-BA message having a multi-station Block ACK (M-BA) frame format, the M-BA frame format including a first indicator to indicate the first feedback message is the H-BA message. ### Claim 9 (depends on 8) The method of claim 8, wherein the M-BA frame format includes a BA information field, the BA information field including at least the first indicator and one or more codeword-level bitmaps of the H-BA message. ### Claim 10 (depends on 1) The method of claim 1, wherein the first feedback message obtained from the second WLAN device is a C-BA message, the C-BA message including one or more MPDU-level bitmaps. ### Claim 11 (depends on 1) The method of claim 1, wherein the first feedback message obtained from the second WLAN device is a negative ACK (N-ACK) message, the N-ACK message indicating a reception failure of the first HARQ frame. ### Claim 12 (depends on 11) The method of claim 11, wherein the N-ACK message has an M-BA frame format, the M-BA frame format including a second indicator to indicate the first feedback message is the N-ACK message, or a bitmap having bits set to zero to indicate the first feedback message is the N-ACK message. ### Claim 13 (depends on 1) The method of claim 1, further comprising: in response to determining the first feedback message is not obtained from the second WLAN device, retransmitting the first HARQ frame to the second WLAN device, transmitting a different HARQ frame to the second WLAN device, or transmitting a HARQ Block ACK request (H-BAR) message to the second WLAN device. ### Claim 14 (depends on 1) The method of claim 1, further comprising: in response to determining the first feedback message is not obtained from the second WLAN device within a time period after transmission of the first HARQ frame, transmitting an H-BAR message to the second WLAN device, the H-BAR message including an H-BA request or a HARQ reset request. ### Claim 15 (depends on 14) The method of claim 14, further comprising: in response to the H-BAR message including the H-BA request, obtaining an H-BA message from the second WLAN device. ### Claim 16 (depends on 14) The method of claim 14, further comprising: in response to the H-BAR message including the HARQ reset request, obtaining an ACK message from the second WLAN device, the ACK message acknowledging completion of a HARQ reset. ### Claim 17 (depends on 14) The method of claim 14, wherein transmitting the H-BAR message to the second WLAN device includes transmitting a multi-user (MU) BAR trigger frame that includes the H-BAR message. ### Claim 18 A method performed by an apparatus of a second wireless local area network (WLAN) device for implementing a hybrid automatic repeat request (HARQ) protocol, comprising: receiving a first HARQ frame from a first WLAN device; determining whether to generate a first feedback message associated with the first HARQ frame; responsive to determining to generate the first feedback message transmitting the first feedback message to the first WLAN device, the first feedback message including HARQ acknowledgement information or non-HARQ acknowledgement information associated with the first HARQ frame; and receiving a second frame from the first WLAN device, the second frame being a second HARQ frame if the first feedback message included the HARQ acknowledgement information or an automatic repeat request (ARQ) frame if the first feedback message included the non-HARQ acknowledgement information. ### Claim 19 (depends on 18) The method of claim 18, wherein the first feedback message is a HARQ Block Acknowledgement (H-BA) message, the H-BA message including the HARQ acknowledgement information. ### Claim 20 (depends on 19) The method of claim 19, further comprising: determining to generate the H-BA message based, at least in part, on determining at least a portion of codewords associated with the first HARQ frame were successfully received and a remaining portion of the codewords were unsuccessfully received, and determining to enable the HARQ protocol. ### Claim 21 (depends on 18) The method of claim 18, further comprising: determining to disable the HARQ protocol based, at least in part, on the first HARQ frame; determining to generate the first feedback message that includes the non-HARQ acknowledgement information in response to determining to disable the HARQ protocol; and responsive to determining to generate the first feedback message that includes the non-HARQ acknowledgement information, transmitting the first feedback message including the non-HARQ acknowledgement information to the first WLAN device. ### Claim 22 (depends on 21) The method of claim 21, wherein the first feedback message that includes the non-HARQ acknowledgement information is a compressed Block ACK (C-BA) message, the C-BA message including one or more MPDU-level bitmaps. ### Claim 23 (depends on 21) The method of claim 21, wherein the first feedback message that includes the non-HARQ acknowledgement information is a negative ACK (N-ACK) message, the N-ACK message indicating a reception failure of the first HARQ frame. ### Claim 24 An apparatus of a first wireless local area network (WLAN) device for implementing a hybrid automatic repeat request (HARQ) protocol, comprising: one or more interfaces configured to: output a first HARQ frame for transmission to a second WLAN device; and one or more processors configured to: determine whether a first feedback message is obtained from the second WLAN device; and responsive to obtainment of the first feedback message, determine whether the first feedback message includes HARQ acknowledgement information or non-HARQ acknowledgment information; and the one or more interfaces configured to: output a second frame for transmission to the second WLAN device, the second frame being a second HARQ frame if the first feedback message includes the HARQ acknowledgement information or an automatic repeat request (ARQ) frame if the first feedback message includes the non-HARQ acknowledgement information. ### Claim 25 (depends on 24) The apparatus of claim 24, wherein the first feedback message is a HARQ Block Acknowledgement (H-BA) message, the H-BA message including the HARQ acknowledgment information, and the HARQ acknowledgement information including one or more bitmaps. ### Claim 26 (depends on 25) The apparatus of claim 25, wherein the one or more bitmaps of the H-BA message include at least one of: one or more codeword-level bitmaps; and one or more media access control protocol data units (MPDU)-level bitmaps. ### Claim 27 An apparatus of a second wireless local area network (WLAN) device for implementing a hybrid automatic repeat request (HARQ) protocol, comprising: one or more interfaces configured to: obtain a first HARQ frame from a first WLAN device; and one or more processors configured to: determine whether to generate a first feedback message associated with the first HARQ frame; and the one or more interfaces configured to: output the first feedback message for transmission to the first WLAN device, the first feedback message including HARQ acknowledgement information or non-HARQ acknowledgement information associated with the first HARQ frame; and obtain a second frame from the first WLAN device, the second frame being a second HARQ frame if the first feedback message included the HARQ acknowledgement information or an automatic repeat request (ARQ) frame if the first feedback message included the non-HARQ acknowledgement information. ### Claim 28 (depends on 27) The apparatus of claim 27, wherein the first feedback message is an H-BA message having a multi-station Block ACK (M-BA) frame format, the M-BA frame format including a first indicator to indicate the first feedback message is the H-BA message. ### Claim 29 (depends on 28) The apparatus of claim 28, wherein the M-BA frame format includes a BA information field, the BA information field including at least the first indicator and one or more codeword-level bitmaps of the H-BA message.