Station (STA), access point (AP) and method of communication in the presence of spatial reuse

1. An apparatus of a first station (STA), the apparatus comprising: memory; and

processing circuitry, configured to:

determine a received signal strength indicator (RSSI) based on one or more inbound physical layer convergence procedure (PLCP) protocol data units (PPDUs) received at the first STA in a channel;

contend for a transmission opportunity (TXOP) to obtain access to the channel;

determine, based at least partly on a comparison between the RSSI of the one or more inbound PPDUs received at the first STA and a predetermined threshold, whether spatial reuse (SR) transmissions by one or more second STAs are permissible, the SR transmissions by the one or more second STAs at least partially concurrent to transmissions by the first STA within the TXOP in the channel; and

encode, for transmission in the channel during the TXOP, an outbound PPDU that includes an SR indicator that is based on the comparison, wherein a first value of the SR indicator indicates that the SR transmissions by the one or more second STAs at least partially concurrent with transmission of the outbound PPDU by the first STA are permissible and a second value of the SR indicator indicates that the SR transmissions by the one or more second STAs at least partially concurrent with transmission of the outbound PPDU by the first STA are impermissible.

2. The apparatus according to claim 1 , the processing circuitry further configured to:

determine that the SR transmissions are permissible if the RSSI is greater than or equal to the threshold; and

determine that the SR transmissions are impermissible if the RSSI is less than the threshold.

3. The apparatus according to claim 2 , the processing circuitry further configured to:

determine the RSSI based on an average signal strength of the latest inbound PPDU received at the first STA.

4. The apparatus according to claim 2 , the processing circuitry further configured to:

determine per-PPDU average signal strengths of the one or more inbound PPDUs; and

determine the RSSI based on an average of the per-PPDU average signal strengths.

5. The apparatus according to claim 2 , the processing circuitry further configured to:

determine per-PPDU average signal strengths of the one or more inbound PPDUs; and

determine the RSSI based on a minimum of the per-PPDU average signal strengths.

6. The apparatus according to claim 1 , wherein if the RSSI is greater than or equal to the threshold, the SR indicator is restricted to the first value.

7. The apparatus according to claim 1 , wherein:

the first STA is arranged to operate in accordance with a wireless local area network (WLAN) protocol,

the threshold is an SR disallow RSSI threshold, and

the SR indicator includes an SR disallow bit that is included in a high-efficiency (HE) signal (HE-SIG) field of the outbound PPDU.

8. The apparatus according to claim 1 , wherein:

the first STA is arranged to operate in accordance with a wireless local area network (WLAN) protocol,

the one or more inbound PPDUs are received at the first STA from a first access point (AP),

the SR transmissions include overlapping basic service set (©BSS) SR transmissions by one or more other STAs of a second AP.

9. The apparatus according to claim 1 , wherein:

the one or more inbound PPDUs are received at the first STA from a destination STA,

the outbound PPDU is encoded for transmission to the destination STA.

10. The apparatus according to claim 1 , wherein:

the outbound PPDU includes a length field that indicates a length of a transmission period over which the outbound PPDU is to be transmitted,

the first value of the SR indicator indicates that the SR transmissions are permissible during the transmission period, and

the second value of the SR indicator indicates that the SR transmissions are impermissible during the transmission period.

11. The apparatus according to claim 1 , wherein the memory is configurable to store the threshold.

12. The apparatus according to claim 1 , wherein the processing circuitry includes a baseband processor to determine the RSSI, to determine whether the SR transmissions are permissible, and to encode the outbound PPDU.

13. The apparatus according to claim 1 , wherein the apparatus further includes a transceiver to receive the one or more inbound PPDUs and to transmit the outbound PPDU.

14. A method of communication at a station (STA), the method comprising:

determining a received signal strength indicator (RSSI) based on one or more inbound physical layer convergence procedure (PLCP) protocol data units (PPDUs) received at the STA;

contending for a transmission opportunity (TXOP) to obtain access to a channel;

determining, based at least partly on a comparison between the RSSI of the one or more inbound PPDUs received at the STA and a predetermined threshold, whether spatial reuse (SR) transmissions by one or more other STAs in the channel during the TXOP are allowed or disallowed; and

encoding, for transmission in the channel during the TXOP, an outbound PPM that includes an SR indicator based on the comparison, wherein a first value of the SR indicator indicates that the SR transmissions by the one or more other STAs are allowed and a second value of the SR indicator indicates that the SR transmissions by the one or more other STAs are disallowed.

15. The method according to claim 14 , further comprising:

determining that the SR transmissions are allowed if the RSSI is greater than or equal to the threshold; and

determining that the SR transmissions are disallowed if the RSSI is less than the threshold.

16. An apparatus of an access point (AP), the apparatus comprising: memory; and processing circuitry, configured to:

encode, for transmission to a station (STA), a handoff threshold that indicates a minimum received signal strength indicator (RSSI) for received PPDUs for STA operation without a handoff to another AP of the network;

determine a received signal strength indicator (RSSI) for the STA based on one or more uplink physical layer convergence procedure (PLCP) protocol data units (PPDUs) received by the AP from the STA;

contend for a transmission opportunity (TXOP) to obtain access to a channel;

determine, based at least partly on a comparison between the RSSI of the one or more uplink PPDUs received by the AP and a predetermined threshold, whether spatial reuse (SR) transmissions by one or more other devices in the channel during the TXOP are permissible; and

encode, for transmission to the STA in the channel during the TXOP, a downlink PPDU that includes an SR indicator that is based on the comparison, wherein a first value of the SR indicator indicates that the SR transmissions by the one or more other devices are permissible and a second value of the SR indicator indicates that the SR transmissions by the one or more other devices are impermissible.

17. The apparatus according to claim 16 , the processing circuitry further configured to:

determine that the SR transmissions are permissible if the RSSI is greater than or equal to the threshold; and

determine that the SR transmissions are impermissible if the RSSI is less than the threshold.

18. The apparatus according to claim 16 , wherein:

the AP is arranged to operate in accordance with a wireless local area network (WLAN) protocol,

the threshold is an SR disallow RSSI threshold, and

the SR indicator includes an SR disallow bit that is included in a high-efficiency (HE) signal (HE-SIG) field of the downlink PPDU.