Traffic management for wireless stations (STAs) that do not support restricted target wake time (r-TWT) operation
This disclosure provides methods, devices and systems for protecting latency-sensitive communications, during restricted target wake time (r-TWT) service periods (SPs), from non-legacy STAs that do not support r-TWT operation. Some implementations more specifically relate to preventing STAs that are not members of an r-TWT SP from acquiring transmit opportunities (TXOPs) that would otherwise overlap with the start of the r-TWT SP. In some implementations, the AP may require all non-legacy STAs associated with its basic service set (BSS) to support r-TWT operation. In some other implementations, the AP may attempt to capture a wireless channel associated with the r-TWT SP within a fixed period preceding the r-TWT SP. In some other implementations, the AP may require all associated STAs to transmit a request-to-send (RTS) frame when attempting to acquire a TXOP. Still further, in some implementations, the AP may limit the duration of TXOPs acquired by non-member STAs.
1. A method for wireless communication by a wireless access point (AP), comprising:
transmitting a first packet carrying basic service set (BSS) information for a BSS managed by the wireless AP, the BSS information indicating that wireless stations (STAs), in order to associate with the wireless AP to join the BSS, must, while thereafter operating in the BSS:
support restricted target wake time (r-TWT) operation in the BSS; or
perform a request-to-send (RTS)/clear-to-send (CTS) exchange when attempting to acquire any TXOP that exceeds a threshold duration;
receiving a second packet from a wireless STA that indicates that the wireless STA will support the r-TWT operation in the BSS or perform an RTS/CTS exchange when attempting to acquire any TXOP that exceeds the threshold duration; and
associating with the wireless STA in accordance with the reception of the second packet indicating that the wireless STA will support the r-TWT operation in the BSS or perform the RTS/CTS exchange when attempting to acquire any TXOP that exceeds the threshold duration.
2. The method of claim 1 , wherein the BSS information that indicates that wireless STAs, in order to associate with the wireless AP to join the BSS, must support r-TWT operation while thereafter operating in the BSS is carried in a non-legacy operation element of the first packet.
3. The method of claim 1 , wherein the BSS information indicates a maximum transmit opportunity (TXOP) duration allowed by the BSS for STAs that are not associated with an r-TWT service period (SP) associated with other STAs in the BSS.
4. The method of claim 3 , wherein the BSS information is dynamically updated based on a timing of the r-TWT SP.
5. The method of claim 3 , wherein the maximum TXOP duration spans a single medium access control (MAC) service data unit (MSDU).
6. The method of claim 1 , wherein the BSS information that indicates that wireless STAs, in order to associate with the wireless AP to join the BSS, must perform the RTS/CTS exchange when attempting to acquire any TXOP that exceeds the threshold duration is carried in a legacy operation element of the first packet.
7. The method of claim 1 , wherein the threshold duration is equal to 32 microseconds.
8. The method of claim 1 , further comprising:
receiving, at a first time, an RTS frame from a first STA requesting a TXOP that exceeds the threshold duration, the first time occurring prior to the start of an r-TWT SP; and
selectively responding to the RTS frame based on the requested TXOP and a duration between the first time and the start of the r-TWT SP.
9. The method of claim 8 , wherein the selective responding to the RTS frame comprises:
transmitting a CTS frame that allocates the requested TXOP to the first STA based on the requested TXOP being shorter than or equal to the duration between the first time and the start of the r-TWT SP.
10. The method of claim 8 , wherein the selective responding to the RTS frame comprises:
transmitting a CTS frame that allocates, to the first STA, a TXOP shorter than the requested TXOP based on the requested TXOP being longer than the duration between the first time and the start of the r-TWT SP.
11. The method of claim 8 , wherein the selective responding to the RTS frame comprises:
transmitting a CTS-to-self frame that reserves a TXOP longer than or equal to the requested TXOP based on the requested TXOP being longer than the duration between the first time and the start of the r-TWT SP.
12. The method of claim 8 , wherein the wireless AP does not respond to the RTS frame based on the requested TXOP being longer than the duration between the first time and the start of the r-TWT SP.
13. The method of claim 8 , further comprising:
allocating the requested TXOP to the first STA after the start of the r-TWT SP based on the requested TXOP being longer than the duration between the first time and the start of the r-TWT SP.
14. A wireless communication device comprising:
at least one processor; and
at least one memory communicatively coupled with the at least one processor and storing processor-readable code that, when executed by the at least one processor, is configured to:
transmit a first packet carrying basic service set (BSS) information for a BSS managed by the wireless communication device, the BSS information indicating that wireless stations (STAs), in order to associate with the wireless communication device to join the BSS, must, while thereafter operating in the BSS:
support restricted target wake time (r-TWT) operation in the BSS; or
perform a request-to-send (RTS)/clear-to-send (CTS) exchange when attempting to acquire any TXOP that exceeds a threshold duration;
receive a second packet from a wireless STA that indicates that the wireless STA will support the r-TWT operation in the BSS or perform an RTS/CTS exchange when attempting to acquire any TXOP that exceeds the threshold duration; and
associate with the wireless STA in accordance with the reception of the second packet indicating that the wireless STA will support the r-TWT operation in the BSS or perform the RTS/CTS exchange when attempting to acquire any TXOP that exceeds the threshold duration.
15. The wireless communication device of claim 14 , wherein the BSS information that indicates that wireless STAs, in order to associate with the wireless communication device to join the BSS, must support r-TWT operation while thereafter operating in the BSS is carried in a non-legacy operation element of the first packet.
16. The wireless communication device of claim 14 , wherein the BSS information indicates a maximum transmit opportunity (TXOP) duration allowed by the BSS for STAs that are not associated with an r-TWT service period (SP) associated with other STAs in the BSS.
17. The wireless communication device of claim 16 , wherein the BSS information is dynamically updated based on a timing of the r-TWT SP.
18. The wireless communication device of claim 16 , wherein the maximum TXOP duration spans a single medium access control (MAC) service data unit (MSDU).
19. The wireless communication device of claim 14 , wherein the BSS information that indicates that wireless STAs, in order to associate with the wireless communication device to join the BSS, must perform the RTS/CTS exchange when attempting to acquire any TXOP that exceeds the threshold duration is carried in a legacy operation element of the first packet.
20. The wireless communication device of claim 14 , wherein the threshold duration is equal to 32 microseconds.
21. The wireless communication device of claim 14 , wherein the code, when executed by the at least one processor, is further configured to:
receive, at a first time, an RTS frame from a first STA requesting a TXOP that exceeds the threshold duration, the first time occurring prior to the start of an r-TWT SP; and
selectively respond to the RTS frame based on the requested TXOP and a duration between the first time and the start of the r-TWT SP.
22. The wireless communication device of claim 21 , wherein, to selectively respond to the RTS frame, the code, when executed by the at least one processor, is configured to:
transmit a CTS frame that allocates the requested TXOP to the first STA based on the requested TXOP being shorter than or equal to the duration between the first time and the start of the r-TWT SP.
23. The wireless communication device of claim 21 , wherein, to selectively respond to the RTS frame, the code, when executed by the at least one processor, is configured to:
transmit a CTS frame that allocates, to the first STA, a TXOP shorter than the requested TXOP based on the requested TXOP being longer than the duration between the first time and the start of the r-TWT SP.
24. The wireless communication device of claim 21 , wherein, to selectively respond to the RTS frame, the code, when executed by the at least one processor, is configured to:
transmit a CTS-to-self frame that reserves a TXOP longer than or equal to the requested TXOP based on the requested TXOP being longer than the duration between the first time and the start of the r-TWT SP.
25. The wireless communication device of claim 21 , wherein the wireless communication device does not respond to the RTS frame based on the requested TXOP being longer than the duration between the first time and the start of the r-TWT SP.
26. The wireless communication device of claim 21 , wherein the code, when executed by the at least one processor, is further configured to:
allocate the requested TXOP to the first STA after the start of the r-TWT SP based on the requested TXOP being longer than the duration between the first time and the start of the r-TWT SP.