Channel access method in wireless LAN system
A channel access method in a wireless LAN system is disclosed. The channel access method for a terminal comprises the steps of: receiving a beacon transmitted from an access point; determining a channel access slot of a terminal allocated on the basis of the beacon; transmitting a data transmission request from the channel access slot to the access point; and receiving data transmission slot allocation information corresponding to the data transmission request from the access point. Thus, the present invention can reduce power consumption of the terminal.
1. A method for channel access by a terminal, the method comprising:
transmitting a Power Save (PS)-Poll frame or a trigger frame to an access point; and
receiving, in response to the PS-Poll frame or the trigger frame, from the access point, a response frame including data transmission time information, wherein data transmission from the access point to the terminal is performed at a time indicated by the data transmission time information,
wherein the response frame is a Null Data Packet (NDP) type frame including a Short Training Field (STF) field, a Long Training Field (LTF) field, and a Signal (SIG) field without a Data field, and the data transmission time information is included in the SIG field.
2. The method of claim 1 , wherein the response frame is Acknowledgement (ACK) frame.
3. The method of claim 1 , wherein the data transmission time information includes a value for Time Synchronization Function (TSF).
4. The method of claim 1 , wherein the data transmission time information includes an offset time information relative to a start time of data transmission period.
5. The method of claim 1 , wherein the terminal enters a power saving mode after receiving the response frame, and
wherein the terminal wakes up at a time indicated by the data transmission time information.
6. A method by an access point for supporting channel access of a terminal, the method comprising:
receiving a Power Save (PS)-Poll frame or a trigger frame from the terminal; and
transmitting, in response to the PS-Poll frame or the trigger frame, to the terminal, a response frame including data transmission time information, wherein data transmission from the access point to the terminal is performed at a time indicated by the data transmission time information,
wherein the response frame is a Null Data Packet (NDP) type frame including a Short Training Field (STF) field, a Long Training Field (LTF) field, and a Signal (SIG) field without a Data field, and the data transmission time information is included in the SIG field.
7. The method of claim 6 , wherein the response frame is Acknowledgement (ACK) frame.
8. The method of claim 6 , wherein the data transmission time information includes a value for Time Synchronization Function (TSF).
9. The method of claim 6 , wherein the data transmission time information includes an offset time information relative to a start time of data transmission period.
10. A terminal for performing channel access, the terminal comprising:
a transceiver; and
a processor,
wherein the processor is configured to:
transmit, using the transceiver, a Power Save (PS)-Poll frame or a trigger frame to an access point; and
receive, in response to the PS-Poll frame or the trigger frame, using the transceiver from the access point, a response frame including data transmission time information, wherein data transmission from the access point to the terminal is performed at a time indicated by the data transmission time information,
wherein the response frame is a Null Data Packet (NDP) type frame including a Short Training Field (STF) field, a Long Training Field (LTF) field, and a Signal (SIG) field without a Data field, and the data transmission time information is included in the SIG field.
11. An access point for supporting channel access of a terminal, the access point comprising:
a transceiver; and
a processor,
wherein the processor is configured to:
receive, using the transceiver, a Power Save (PS)-Poll frame or a trigger frame from the terminal; and
transmit, in response to the PS-Poll frame or the trigger frame, using the transceiver to the terminal, a response frame including data transmission time information, wherein data transmission from the access point to the terminal is performed at a time indicated by the data transmission time information,
wherein the response frame is a Null Data Packet (NDP) type frame including a Short Training Field (STF) field, a Long Training Field (LTF) field, and a Signal (SIG) field without a Data field, and the data transmission time information is included in the SIG field.