Hybrid automatic repeat request (HARQ) in a wireless local area network (WLAN)
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.
1. A method performed by an apparatus of a first wireless local area network (WLAN) device, comprising:
transmitting a first hybrid automatic repeat request (HARQ) frame to a second WLAN device;
receiving, in response to the first HARQ frame, a first feedback message from the second WLAN device that indicates whether to enable a HARQ protocol or a non-HARQ protocol; and
transmitting a frame to the second WLAN device based at least in part on the first feedback message, the frame being a second HARQ frame if the first feedback message indicates to enable the HARQ protocol and the frame being a non-HARQ frame if the first feedback message indicates to enable the non-HARQ protocol.
2. The method of claim 1 , wherein the first feedback message is a HARQ Block Acknowledgement (H-BA) message and includes one or more bitmaps.
3. 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.
4. 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.
5. 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.
6. The method of claim 3 , wherein the one or more codeword-level bitmaps identify one or more groups of codewords.
7. The method of claim 2 , wherein transmitting the frame to the second WLAN device is based, at least in part, on the one or more bitmaps included in the H-BA message.
8. 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.
9. 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.
10. The method of claim 9 , wherein the BA information field includes one or more BA control fields and each of the one or more BA control fields includes the first indicator.
11. An apparatus of a first wireless local area network (WLAN) device, comprising:
one or more interfaces configured to:
transmitting a first hybrid automatic repeat request (HARQ) (HARQ) frame to a second WLAN device; and
one or more processors configured to:
receive, in response to the first HARQ frame, a first feedback message from the second WLAN device that indicates whether to enable a HARQ protocol or a non-HARQ protocol; and
the one or more interfaces configured to:
transmit a frame to the second WLAN device based at least in part on the first feedback message, the frame being a second HARQ frame if the first feedback message indicates to enable the HARQ protocol and the frame being a non-HARQ frame if the first feedback message indicates to enable the non-HARQ protocol.
12. The apparatus of claim 11 , wherein the first feedback message is a HARQ Block Acknowledgement (H-BA) message and includes one or more bitmaps.
13. The apparatus of claim 12 , 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.
14. The apparatus of claim 13 , 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.
15. The apparatus of claim 14 , wherein codewords of each of the one or more codeword-level bitmaps are identified by one or more starting codeword indexes.
16. The apparatus of claim 14 , wherein the one or more codeword-level bitmaps identify one or more groups of codewords.
17. An apparatus of a second wireless local area network (WLAN) device, comprising:
one or more interfaces configured to:
receive a first hybrid automatic repeat request (HARQ) frame from a first WLAN device; and
one or more processors configured to:
determine whether to enable a HARQ protocol or a non-HARQ protocol based at least in part on the first HARQ frame; and
the one or more interfaces configured to:
transmit a first feedback message to the first WLAN device that indicates whether to enable the HARQ protocol or the non-HARQ protocol.
18. The apparatus of claim 17 , wherein the first feedback message is a HARQ Block Acknowledgement (H-BA) message.
19. The apparatus of claim 18 , wherein the H-BA message includes at least one of:
one or more codeword-level bitmaps; and
one or more media access control protocol data units (MPDU) level bitmaps.
20. The apparatus of claim 18 , wherein the one or more processors are configured to:
determine to generate the H-BA message based, at least in part, on
a determination that 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
a determination to enable the HARQ protocol.