Method and apparatus for accessing channel in WLAN system

• US 9,894,607 B2
• Filed: 02/17/2017
• Issued: 02/13/2018
• Est. Priority Date: 04/02/2012
• Status: Expired due to Fees

• 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
• Primary Examiner(s): Scheibel, Robert C
• Application Number:
  US15/435,750
• Publication Number:
  US 20170164283A1
• Time in Patent Office: 361 Days
• Field of Search: None
• 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 controlling channel access by an access point (AP) in a wireless communication system, comprising:

receiving listening interval information from a station (STA),

wherein the listening interval is a period that a power save STA wakes up and listens to a beacon frame from the AP; and

controlling the channel access based on a mode of the STA,

wherein the beacon frame including a traffic indication map (TIM) element is transmitted during the listening interval when the STA is in a TIM mode,

wherein a power save (PS)-Poll for channel access is received during the listening interval when the STA is in a non-TIM mode, and

wherein the AP receives the PS PS-Poll from the STA in the non-TIM mode without transmitting the beacon frame including the TIM element to the STA during listening interval.

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 in the non-TIM mode transmits the PS-Poll during the listening interval until the transmission of the PS-Poll is successful,

wherein, if the transmission of the PS-Poll continuously fails in a predetermined number of listening intervals, the STA transmits the PS-Poll a first listening interval and the start of a second listening interval,

wherein the first listening interval is the last listening interval where the transmission of the PS-Poll has failed, and

wherein the second listening interval is a next listening interval after the first listening interval.

4. The method according to claim 3, 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.

5. The method according to claim 1, wherein, even if the transmission 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.

6. An access point (AP) for controlling channel access in a wireless communication system comprising:

a transceiver; and

a processor configured to control the transceiver,

wherein the processor is further configured to;

receive listening interval information from a station (STA),

wherein the listening interval is a period that a power save STA wakes up and listens for a beacon frame from the AP, and

control channel access based on a mode of the STA,

wherein a beacon frame including a traffic indication map (TIM) element is transmitted to the STA during the listening interval when the STA is in a TIM mode,

wherein a power save (PS)-poll for channel access to the AP is received during the listening interval when the STA is in a non-TIM mode, and

wherein the AP receives the PS PS-Poll from the STA in the non-TIM mode without transmitting the beacon frame including TIM element to the STA in listening interval.

7. The AP according to claim 6, 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.

8. The AP according to claim 6, wherein the PS-Poll is transmitted during listening interval in the non-TIM mode until the transmission of the PS-Poll is successful,

wherein, if the transmission of the PS-Poll continuously fails in a predetermined number of listening intervals, the STA transmits the PS-Poll a first listening interval and the start of a second listening interval,

wherein the first listening interval is the last listening interval where the transmission of the PS-Poll has failed, and

wherein the second listening interval is a next listening interval after the first listening interval.

9. The AP according to claim 8, 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.

10. The AP according to claim 6, wherein, even if transmission 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.