Channel access method in wireless LAN system

• US 9,591,566 B2
• Filed: 07/25/2013
• Issued: 03/07/2017
• Est. Priority Date: 08/16/2012
• Status: Active Grant

• Current Assignee: Golden Eye Technologies LLC (Harfang IP Investment Corp)
• Original Assignee: KT Corporation
• Inventors: Kim, Joo Young, JEONG, Yang Seok
• Primary Examiner(s): Mered, Habte
• Application Number:
  US14/422,309
• Publication Number:
  US 20150230170A1
• Time in Patent Office: 1,321 Days
• US Class Current: 1/1
• CPC Class Codes: H04L 1/16 in which the return channel carries supervisory signals, e.g. repetition request signals
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04W 52/0209 in terminal devices terminal devices per se H04W88/02
• CPC Class Codes: H04W 52/0235 where the received signal is a power saving command
• CPC Class Codes: H04W 56/004 compensating for timing error of reception due to propagation delay
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 74/06 using polling
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

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.

Claims

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.