METHOD AND APPARATUS FOR ACCESSING CHANNEL IN WLAN SYSTEM

• US 20150131547A1
• Filed: 04/29/2013
• Published: 05/14/2015
• Est. Priority Date: 04/28/2012
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Seok, Yongho
• Granted Patent: US 9,510,367 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 4/08 User group management
• CPC Class Codes: H04W 40/244 using a network of reference devices, e.g. beaconing
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/30 Resource management for broadcast services
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02
• 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. The method for accessing a channel from a station (STA) in a wireless communication system, according to one embodiment of the present invention, comprises the steps of: receiving from an access point (AP) a first frame including a traffic indication map (TIM) and a restricted access window (RAW) parameter set component; determining a RAW in which channel access of the STA is permitted, on the basis of the RAW parameter set (RPS) component; and transmitting a second frame to the AP from within the RAW that is determined, wherein the RPS component includes at least one RAW allocation field, and each of the at least one RAW allocation fields can include a RAW group field, a RAW starting point field, and a RAW duration field.

Claims

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

receiving, from an access point (AP), a first frame containing a traffic indication map (TIM) element and a restricted access window (RAW) parameter set element;

determining an RAW allowing channel access of the STA based on the RAW parameter set (RPS) element; and

transmitting a second frame to the AP within the determined RAW,

wherein the RPS element comprises at least one RAW assignment field,

wherein each of the at least one RAW assignment field comprises a RAW group field, a RAW start time field, and a RAW duration field.

2. The method according to claim 1, wherein the RAW group field indicates association identifiers (AIDs) of STAs allowed to perform the channel access within the RAW.

3. The method according to claim 1, wherein whether or not the STA belongs to a group indicated by the RAW group field is determined.

4. The method according to claim 1, wherein the RAW comprises at least one slot.

5. The method according to claim 4, wherein each of the at least one RAW assignment field further comprises a slot duration field and a cross slot boundary field.

6. The method according to claim 5, wherein the slot duration field indicates a duration of the at least one slot having the same value within the RAW.

7. The method according to claim 5, wherein the cross slot boundary field indicates whether or not the transmission by the STA is allowed to cross a slot boundary.

8. The method according to claim 1, wherein each of the at least one RAW assignment field further comprises a field for indicating whether or not the channel access is restricted to paged STAs only.

9. The method according to claim 1, wherein the STA operates in a doze state before a time, and switches to an awake state at the time, the channel access within the RAW being allowed at the time.

10. The method according to claim 1, wherein the first frame is a beacon frame.

11. The method according to claim 1, wherein the second frame is a power save (PS)-Poll frame or a trigger frame.

12. The method according to claim 1, wherein the second frame is transmitted within the RAW based on enhanced distributed channel access (EDCA).

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

a transceiver; and

a processor,

wherein the processor is configured to;

receive, from an access point, a first frame containing a traffic indication map (TIM) element and a restricted access window (RAW) parameter set element using the transceiver;

determine an RAW allowing channel access of the STA based on the RAW parameter set (RPS) element; and

transmit a second frame to an access point (AP) within the determined RAW using the transceiver,

wherein the RPS element comprises at least one RAW assignment field,

wherein each of the at least one RAW assignment field comprises a RAW group field, a RAW start time field, and a RAW duration field.