Target wake time (TWT) scheduling for orthogonal frequency-division multiple access (OFDMA) channelization

1. A method of operating a wireless device, the method comprising:

receiving a frame at the wireless device, wherein a format of the frame comprises

(i) a field indicating a target wake time (TWT),

(ii) a first subfield having a first value that indicates a digital modulation channelization scheme, and

(iii) a second subfield having a second value that indicates a transmission direction, wherein the second subfield uses one or more bits corresponding to one or more subfields that are not needed in TWT scheduling for transmissions that employ the digital modulation channelization scheme; and

powering on the wireless device at the target wake time indicated by the field in the frame, wherein the powering on the wireless device enables the wireless device to transmit additional frames via a wireless channel based on (i) the first value set in the first subfield of the frame and (ii) the second value set in the second subfield of the frame.

2. The method of claim 1 , wherein the first value set in the first subfield corresponds to Orthogonal Frequency Division Multiple Access (OFDMA) digital modulation channelization, and powering on the wireless device further enables the wireless device to transmit the additional frames according to an OFDMA access scheme.

3. The method of claim 1 , wherein the second value set in the second subfield corresponds to an uplink transmission, and powering on the wireless device further enables the wireless device to transmit the additional frames in an uplink transmission.

4. The method of claim 1 , wherein the second value set in the second subfield corresponds to a downlink transmission, and powering on the wireless device further enables the wireless device to transmit the additional frames in a downlink transmission.

5. The method of claim 1 , wherein the format of the frame comprises a third subfield indicating flow type, and the wireless device transmits a short Power Save (PS)-Poll frame in response to the received frame.

6. The method of claim 1 , wherein the wireless device is a wireless station (STA).

7. The method of claim 6 , wherein the STA is connected to an access point (AP) via a wireless network.

8. The method of claim 1 , wherein the format of the frame comprises a third subfield indicating a TWT duration.

9. The method of claim 1 , comprising aggregating the frame with one or more additional frames based the second subfield.

10. A wireless communication device comprising:

one or more antennas;

transceiver electronics; and

processor electronics programmed to:

detect, subsequent to a point coordination function (PCF) interframe space (PFS) and at a start of a target wait time service period (TWT SP) prior to a contention period, whether a wireless channel is idle;

upon detecting that the wireless channel is idle, transmit one or more frames via the wireless channel using the one or more antennas and the transceiver electronics;

determine whether a collision has occurred during transmitting on the wireless channel; and

upon determining that the collision has occurred, suspend operation of a first backoff procedure at a starting state and initiating a counter for a second backoff procedure.

11. The wireless communication device of claim 10 , wherein the first backoff procedure is an Enhanced Distribution Channel Access (EDCA) backoff procedure and the second backoff procedure is a TWT back off procedure.

12. The wireless communication device of claim 10 , wherein the wireless communication device is an access point (AP).

13. The wireless communication device of claim 10 , wherein the processor electronics are further programmed to transmit a setup management frame with a format comprising one or more fields indicating TWT information, wherein the setup management frame is usable by a second wireless device to establish a next TWT SP.

14. The wireless communication device of claim 13 , wherein the TWT information is a TWT corresponding to the next TWT SP.

15. A wireless communication device, comprising:

one or more antennas;

transceiver electronics; and

processor electronics programmed to:

detect, at a start of a target wait time service period (TWT SP), whether a wireless channel is idle;

upon detecting that the wireless channel is idle, transmit one or more frames via the wireless channel using the one or more antennas and the transceiver electronics;

determine whether a collision has occurred during transmitting on the wireless channel; and

upon determining that the collision has occurred, suspend operation of a first backoff procedure at a starting state and initiating a counter for a second backoff procedure,

wherein the suspending the operation of the first backoff procedure comprises storing one or more values associated with the first backoff procedure associated with the starting state.

16. A wireless communication device, comprising:

one or more antennas;

transceiver electronics; and

processor electronics programmed to:

detect, at a start of a target wait time service period (TWT SP), whether a wireless channel is idle;

upon detecting that the wireless channel is idle, transmit one or more frames via the wireless channel using the one or more antennas and the transceiver electronics;

determine whether a collision has occurred during transmitting on the wireless channel; and

upon determining that the collision has occurred, suspend operation of a first backoff procedure at a starting state and initiating a counter for a second backoff procedure,

wherein the processor electronics are further programmed to: determine whether the counter for the second backoff procedure is equal to zero; and upon detecting that the counter for the second backoff procedure is equal to zero, transmit one or more additional frames via the wireless channel.

17. A system comprising:

a wireless local area network (WLAN);

at least one wireless station (STAB) communicatively coupled with the WLAN; and

an access point (AP) communicatively coupled with the WLAN and programmed to transmit a frame via a broadcast signal to the at least one STA, wherein a format of the frame comprises a first field indicating a target wake time (TWT), a second field indicating a downlink transmission, a third field, separate from the second field, indicating an uplink transmission; a fourth field indicating contention; and a fifth field indicating a number of repeated TWT service periods (SP).

18. The system of claim 17 , wherein the access point is further programmed to transmit an additional frame via the WLAN, wherein an additional format of the additional frame comprises a first subfield indicating Orthogonal Frequency-Division Multiple Access (OFDMA) digital modulation channelization, and a second subfield indicating a transmission direction.

19. The system of claim 18 , wherein the additional format of the additional frame comprises a third subfield indicating a TWT duration.

20. The system of claim 17 , wherein the at least one STA is programmed to: (i) power on at the TWT indicated in first field of the frame; and (ii) transmit via the WLAN based on each the second field, third field, fourth field, and fifth field of the transmitted frame.