METHOD AND APPARATUS FOR ACCESSING CHANNEL IN WLAN SYSTEM

• US 20150334592A1
• Filed: 04/02/2013
• Published: 11/19/2015
• Est. Priority Date: 04/02/2012
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: CHOI, Jinsoo, HAN, Seunghee, KWAK, Jinsam, SEOK, Yongho, KIM, Jeongki
• Granted Patent: US 9,615,286 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04W 28/0221 power availability or consumption
• CPC Class Codes: H04W 4/70 Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/0816 with collision avoidance
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

The present invention relates to a wireless communication system, and more specifically, disclosed are a method and an apparatus for accessing a channel in a WLAN system. A method for accessing the channel from a station (STA) in the wireless communication system, according to one embodiment of the present invention, comprises a step of transmitting a power save-poll (PS-poll) for channel accessing from a listening interval to an access point, wherein the station operates in a non-traffic indication map (TIM) mode which is not limited by a TIM element that is transmitted from the access point, and wherein the time of transmission of the PS-poll is not limited by the TIM element.

Claims

1. A method for performing channel access in a station (STA) in a wireless communication system, comprising:

transmitting a power save (PS)-Poll for channel access to an access point (AP) in a listening interval when the STA is in a non-TIM mode,

wherein the STA in a non-TIM mode does not receive a traffic indication map (TIM) element from the AP, and

wherein the PS-Poll is transmitted without receiving the TIM element.

2. The method according to claim 1, wherein a start time of the listening interval is one of a time for the STA to transmit power management mode setting information to the AP and a time for the STA to receive a response frame in response to the setting information.

3. The method according to claim 1, wherein the STA comprises a sensor type STA.

4. The method according to claim 1, wherein, if transmission of the PS-Poll fails sequentially in a predetermined number during previous listening interval, the STA transmits the PS-Poll at a prior time before the start time of the listening interval.

5. The method according to claim 4, wherein the prior time is a value set through a system parameter or a value preset through a management process between the STA and the AP.

6. The method according to claim 1, wherein, even if the transmitting of the PS-Poll is performed at a second time later than a first time of the listening interval, a transmission time of a next PS-Poll is estimated from the first time rather than from the second time.

7. The method according to claim 1, wherein the STA transmits the PS-poll every listening interval.

8. A station (STA) for performing channel access in a wireless communication system comprising:

a transceiver; and

a processor,

wherein if the STA is in a non-TIM mode in which the STA does not receive a traffic indication map (TIM) element from an access point (AP), the processor is configured to the transceiver to trasmint a power save (PS)-poll to the AP, and

wherein the PS-poll is transmitted to AP without receiving the TIM element.

9. The STA according to claim 8, wherein the processor sets one of a time to transmit power management mode setting information to the AP and a time to receive a response frame in response to the setting information as a start time of the listening interval.

10. The STA according to claim 8, wherein the STA comprises a sensor type STA.

11. The STA according to claim 8, wherein the processor is configured to transmit the PS-Poll at a prior time before the start time of the listening interval when transmission of the PS-Poll continuously fails in a predetermined number of previous listening intervals.

12. The STA according to claim 11, wherein the prior time is a value set through a system parameter or a value preset through a management process between the STA and the AP.

13. The STA according to claim 8, wherein, even if transmission of the PS-Poll is performed at a second time later than a first time of the listening interval, the processor computes a transmission time of a next PS-Poll from the first time rather than from the second time.

14. The STA according to claim 8, wherein the processor is configured to transmit the PS-Poll every listening intervals.