Wireless communication method using limited TWT and wireless communication terminal using same

1 . A wireless communication terminal for wirelessly communicating with a base wireless communication terminal, the wireless communication terminal comprising:

a transceiver; and

a processor,

wherein the processor is configured to:

perform a channel access procedure including obtaining a random integer within a contention window,

transmit low latency traffic configured as traffic for low latency transmission or a response to the low latency traffic within a restricted service period, wherein transmission except for transmission of the low latency traffic and transmission of the response to the low latency traffic is restricted within the restricted service period, and

perform the channel access procedure again when the channel access procedure is completed before a start of the restricted service period and the wireless communication terminal abandons transmission upon determination that frame exchange fails to be completed before the start of the restricted service period, wherein performing the channel access procedure again includes:

maintaining a size of the contention window used for the completed channel access procedure without change, and

obtaining a new random integer within the contention window.

2 . The wireless communication terminal of claim 1 , wherein the processor is configured to terminate a TXOP before a start of the restricted service period.

3 . The wireless communication terminal of claim 1 , wherein the processor is configured not to increase a QoS STA retry counter (QSRC) corresponding to the completed channel access procedure without change when the wireless communication terminal performs the channel access again.

4 . The wireless communication terminal of claim 1 , wherein a quiet interval corresponding to the restricted service period is configured,

all transmissions are not allowed in the quiet interval, and

the processor is configured to:

transmit the low latency traffic or the response to the low latency traffic within the restricted service period by ignoring the quiet interval corresponding to the restricted service period; and

refrain from transmitting a CF-End frame within the restricted service period.

5 . The wireless communication terminal of claim 1 , wherein a quiet interval corresponding to the restricted service period is configured,

all transmissions are not allowed in the quiet interval, and

the processor is configured to:

determine whether to ignore the quiet interval based on a start time point of the restricted service period and a start time point of the quiet interval; and

when determining to ignore the quiet interval, transmit the low latency traffic or the response to the low latency traffic within the restricted service period by ignoring the quiet interval corresponding to the restricted service period.

6 . The wireless communication terminal of claim 5 , wherein the processor is configured to:

ignore the quiet interval when a condition determined based on the start time point of the restricted service period and the start time point of the quiet interval is satisfied; and

refrain from performing all transmissions when the condition determined based on the start time point of the restricted service period and the start time point of the quiet interval fails to be satisfied.

7 . The wireless communication terminal of claim 6 , wherein the condition determined based on the start time point of the restricted service period and the start time point of the quiet interval is that the start time point of the quiet interval and the start time point of the restricted service period are within a predetermined time interval.

8 . A method of operating a wireless communication terminal for wirelessly communicating with a base wireless communication terminal, the method comprising:

performing a channel access procedure including obtaining a random integer within a contention window;

transmitting low latency traffic configured as traffic for low latency transmission or a response to the low latency traffic within a restricted service period, wherein transmission except for transmission of the low latency traffic and transmission of the response to the low latency traffic is restricted within the restricted service period; and

performing the channel access procedure again when the channel access procedure is completed before a start of the restricted service period and the wireless communication terminal abandons transmission upon determination that a frame exchange fails to be completed before the start of the restricted service period, wherein performing the channel access procedure again includes:

maintaining a size of the contention window used for the completed channel access procedure without change, and

obtaining a new random integer within the contention window.

9 . The method of claim 8 , further comprising terminating a TXOP before a start of the restricted service period.

10 . The method of claim 8 , wherein the performing the channel access again comprises not increasing a QoS STA retry counter (QSRC) corresponding to the completed channel access procedure without change when the wireless communication terminal performs the channel access again.

11 . The method of claim 8 , wherein a quiet interval corresponding to the restricted service period is configured,

all transmissions are not allowed in the quiet interval, and

the transmitting the low latency traffic or the response to the low latency traffic within the restricted service period comprises:

transmitting the low latency traffic or the response to the low latency traffic within the restricted service period by ignoring the quiet interval corresponding to the restricted service period; and

refraining from transmitting a CF-End frame within the restricted service period.

12 . The method of claim 8 , wherein a quiet interval corresponding to the restricted service period is configured,

all transmissions are not allowed in the quiet interval, and

the transmitting the low latency traffic or the response to the low latency traffic within the restricted service period comprises:

determining whether to ignore the quiet interval based on a start time point of the restricted service period and a start time point of the quiet interval; and

when determining to ignore the quiet interval, transmitting the low latency traffic or the response to the low latency traffic within the restricted service period by ignoring the quiet interval corresponding to the restricted service period.

13 . The method of claim 12 , wherein the determining whether to ignore the quiet interval based on the start time point of the restricted service period and the start time point of the quiet interval comprises:

ignoring the quiet interval when a condition determined based on the start time point of the restricted service period and the start time point of the quiet interval is satisfied; and

refraining from performing all transmissions when the condition determined based on the start time point of the restricted service period and the start time point of the quiet interval fails to be satisfied.

14 . The method of claim 13 , wherein the condition determined based on the start time point of the restricted service period and the start time point of the quiet interval is that the start time point of the quiet interval and a start time point of the restricted service period are within a predetermined time interval.