Operation for restricted target wake time supported in a next-generation wireless LAN system
The present specification proposes an improved recommendation for TWT operation supported in a next-generation wireless LAN system. According to one embodiment of the present specification, an improved recommendation for constrained TWT operation is defined. According to another embodiment of the present specification, whether an STA performs an NAV protection mechanism can be determined according to the value of a broadcast TWT proposal subfield.
1 . A method in a wireless local area network (LAN) system, the method comprising:
receiving, by a receiving station (STA), a physical protocol data unit (PPDU) comprising a Target Wake Time (TWT) element, from a transmitting STA;
performing, by the receiving STA, communication for latency sensitive traffic with the transmitting STA within a restricted TWT service period (SP) based on the PPDU,
wherein the TWT element includes a broadcast TWT parameter set field,
wherein the broadcast TWT parameter set field includes a request type field having a length of two octets,
wherein the request type field includes a broadcast TWT recommendation subfield having a length of 3 bits,
wherein based on the broadcast TWT recommendation subfield having a first value, the receiving STA performs a Network Allocation Vector (NAV) protection mechanism with the transmitting STA prior to the communication for the latency sensitive traffic when a length of the restricted TWT SP is longer than a transmission time of the latency sensitive traffic,
wherein based on the broadcast TWT recommendation subfield having a second value, the receiving STA does not perform the NAV protection mechanism with the transmitting STA prior to the communication for the latency sensitive traffic when the length of the restricted TWT SP is shorter than or equal to the transmission time of the latency sensitive traffic, and
wherein the NAV protection mechanism is configured based on transmission or reception of a Request to Send (RTS) frame, a Clear to Send (CTS) frame, or a CTS-to-self frame within the restricted TWT SP.
2 . The method of claim 1 , wherein the first value is one of 4 to 7, and the second value is one of 4 to 7.
3 . The method of claim 1 , wherein the communication for latency sensitive traffic is at least one of receiving the latency sensitive traffic and transmitting the latency sensitive traffic.
4 . The method of claim 1 , wherein based on the broadcast TWT recommendation subfield indicating the first value, the receiving STA obtains a transmission opportunity (TXOP) based on the NAV protection mechanism.
5 . The method of claim 1 , wherein a control field having a length of one octet included in the TWT element comprises a negotiation type field,
wherein based on the negotiation type field indicating 2 or 3, the TWT element includes information on a broadcast TWT.
6 . The method of claim 1 , wherein the request type field further includes a TWT request subfield having a length of 1 bit, a TWT setup command subfield having a length of 3 bits, a trigger subfield having a length of 1 bit, a last broadcast parameter set subfield having a length of 1 bit, and a TWT wake interval exponent subfield having a length of 5 bits.
7 . A receiving station (STA) in a wireless local area network (LAN) system, comprising:
a memory;
a transceiver; and
a processor operatively coupled to the memory and the transceiver,
wherein the processor is adapted to:
receive a physical protocol data unit (PPDU) comprising a Target Wake Time (TWT) element, from a transmitting STA;
perform communication for latency sensitive traffic with the transmitting STA within a restricted TWT service period (SP) based on the PPDU,
wherein the TWT element includes a broadcast TWT parameter set field,
wherein the broadcast TWT parameter set field includes a request type field having a length of two octets,
wherein the request type field includes a broadcast TWT recommendation subfield having a length of 3 bits,
wherein based on the broadcast TWT recommendation subfield having a first value, the receiving STA performs a NAV protection mechanism with the transmitting STA prior to the communication for the latency sensitive traffic when a length of the restricted TWT SP is longer than a transmission time of the latency sensitive traffic,
wherein based on the broadcast TWT recommendation subfield having a second value, the receiving STA does not perform the NAV protection mechanism with the transmitting STA prior to the communication for the latency sensitive traffic when the length of the restricted TWT SP is shorter than or equal to the transmission time of the latency sensitive traffic, and
wherein the NAV protection mechanism is configured based on transmission or reception of a Request to Send (RTS) frame, a Clear to Send (CTS) frame, or a CTS-to-self frame within the restricted TWT SP.
8 . A method in a wireless local area network (LAN) system, the method comprising:
transmitting, by a transmitting station (STA), a physical protocol data unit (PPDU) comprising a Target Wake Time (TWT) element, to a receiving STA;
performing, by the transmitting STA, communication for latency sensitive traffic with the receiving STA within a restricted TWT service period (SP) based on the PPDU,
wherein the TWT element format includes a broadcast TWT parameter set field,
wherein the broadcast TWT parameter set field includes a request type field having a length of two octets,
wherein the request type field includes a broadcast TWT recommendation subfield having a length of 3 bits,
wherein based on the broadcast TWT recommendation subfield having a first value, the transmitting STA performs a NAV protection mechanism with the receiving STA prior to the communication for the latency sensitive traffic when a length of the restricted TWT SP is longer than a transmission time of the latency sensitive traffic,
wherein based on the broadcast TWT recommendation subfield having a second value, the transmitting STA does not perform the NAV protection mechanism with the receiving STA prior to the communication for the latency sensitive traffic when the length of the restricted TWT SP is shorter than or equal to the transmission time of the latency sensitive traffic, and
wherein the NAV protection mechanism is configured based on transmission or reception of a Request to Send (RTS) frame, a Clear to Send (CTS) frame, or a CTS-to-self frame within the restricted TWT SP.
9 . The method of claim 8 , wherein of the first value is one of 4 to 7, and the second value is one of 4 to 7.
10 . The method of claim 8 , wherein the communication for latency sensitive traffic is at least one of receiving the latency sensitive traffic and transmitting the latency sensitive traffic.
11 . The method of claim 8 , wherein a control field having a length of one octet included in the TWT element comprises a negotiation type field,
wherein based on the negotiation type field indicating 2 or 3, the TWT element includes information on a broadcast TWT.
12 . The method of claim 8 , wherein the request type field further includes a TWT request subfield having a length of 1 bit, a TWT setup command subfield having a length of 3 bits, a trigger subfield having a length of 1 bit, a last broadcast parameter set subfield having a length of 1 bit, and a TWT wake interval exponent subfield having a length of 5 bits.
13 . The method of claim 8 , wherein based on the broadcast TWT recommendation subfield including the first value, the receiving STA obtains a transmission opportunity (TXOP) based on the NAV protection mechanism.