POWER SAVING MODE OPERATION METHOD IN WIRELESS LAN SYSTEM, AND APPARATUS FOR SAME

• US 20180176865A1
• Filed: 06/03/2016
• Published: 06/21/2018
• Est. Priority Date: 06/04/2015
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: KIM, Jeongki, RYU, Kiseon, CHO, Hangyu
• Granted Patent: US 10,448,333 B2
• Time in Patent Office: Days
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: H04W 52/0235 where the received signal is a power saving command
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• 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 method for a station (STA) to operate in a power saving (PS) mode in a wireless LAN system that supports a high efficiency physical layer protocol data unit (HE PPDU), in one embodiment of the present invention, comprises the steps of: receiving a trigger frame which assigns a resource for transmission of an uplink multi-user (UL MU) PPDU; and determining whether to perform transition to a doze state on the basis of the trigger frame, wherein when the resource is not assigned to the STA through the trigger frame, the STA determines to perform transition to a doze state during a time period determined on the basis of an indicator information value of the trigger frame.

Claims

1. A method of operating in a power saving (PS) mode by a station (STA) in a wireless local area network (LAN) system supporting a high efficiency physical layer protocol data unit (HE PPDU), the method comprising:

receiving a trigger frame for allocating a resource for transmission of an uplink multi-user (UL MU) PPDU; and

determining whether to transition to a doze state based on the trigger frame,

wherein, when the resource is not allocated to the STA through the trigger frame, the STA transit ions to the doze state during a time duration determined based on a value of indicator information of the trigger frame.

2. The method according to claim 1,

wherein the indicator information of the trigger frame has a first value when the resource allocated for transmission of the UL MU PPDU is allocated to STAs of the same group, and has a second value when the resource allocated for transmission of the UL MU PPDU is allocated to STAs of different groups.

3. The method according to claim 2,

wherein, when the indicator information of the trigger frame has the first value, the STA transitions to the doze state during an entire transmission opportunity (TXOP) duration indicated by the trigger frame, and

wherein, when the indicator information of the trigger frame has the second value, the STA transitions to the doze state during a duration corresponding to the UL MU PPDU.

4. The method according to claim 1,

wherein, when the STA receives the trigger frame from an access point (AP) with which the STA is associated and the resource is not allocated to the STA through the trigger frame, the STA determines to transition to the doze state.

5. The method according to claim 4,

wherein, when a target address (TA) of the trigger frame is identical to a basic service set identifier (BSSID) of the AP with which the STA is associated, the STA determines that the trigger frame is transmitted by the AP with which the STA is associated.

6. The method according to claim 4,

wherein the STA that determines to transition to the doze state has one or more of an intra-BSS PPDU PS capability and a trigger-based intra-BSS PS capability.

7. The method according to claim 1,

wherein the value of the indicator information of the trigger frame corresponds to a value of a PS mode field.

8. The method according to claim 7,

wherein the trigger frame further includes information indicating whether a network allocation vector (NAV) is changed during a transmission opportunity (TXOP) duration, and

wherein the STA determines to transition to the doze state when there is no NAV change during the TXOP.

9. The method according to claim 7,

wherein the STA does not transition to the doze state during a specific duration in which a downlink frame is predicted to be received even within a duration during which the STA transitions to the doze state by the PS mode field.

10. The method according to claim 9,

wherein the specific duration corresponds to a duration in which a More Data (MD) field of a previously received downlink frame is set to 1.

11. The method according to claim 10,

wherein, when the PS mode field indicates that the STA operate in the doze state only during a duration corresponding to the UL MU PPDU, the STA transitions to an awake state to receive another trigger frame transmitted after the duration corresponding to the UL MU PPDU.

12. The method according to claim 7,

wherein, when the PS mode field indicates that the STA should operate in the doze state during an entire transmission opportunity (TXOP) duration, the STA assumes that the resource is not allocated to the STA even by other trigger frames transmitted after a duration corresponding to the UL MU PPDU.

13. A station (STA) for operating in a power saving (PS) mode in a wireless local area network (LAN) system supporting a high efficiency physical layer protocol data unit (HE PPDU), the STA comprising:

a receiver configured to receive a trigger frame for allocating a resource for transmission of an uplink multi-user (UL MU) PPDU; and

a processor configured to determine whether the STA should transition to a doze state based on the trigger frame,

wherein, when the resource is not allocated to the STA through the trigger frame, the processor determines that the STA should transition to the doze state during a time duration determined based on a value of indicator information of the trigger frame.

14. The STA according to claim 13,

wherein the indicator information of the trigger frame has a first value when the resource allocated for transmission of the UL MU PPDU is allocated to STAs of the same group and has a second value when the resource allocated for transmission of the UL MU PPDU is allocated to STAs of different groups.

15. The STA according to claim 13,

wherein, when the STA receives the trigger frame from an access point (AP) with which the STA is associated and the resource is not allocated to the STA through the trigger frame, the processor determines that the STA should transition to the doze state.