Power saving method for mobile terminal in wireless local area network

• US 20070115873A1
• Filed: 11/03/2006
• Published: 05/24/2007
• Est. Priority Date: 11/04/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd., Seoul National University Industry Foundation (Seoul National University)
• Original Assignee: Samsung Electronics Co. Ltd., Seoul National University Industry Foundation (Seoul National University)
• Inventors: Jang, Kyung-Hun, Hwang, Hyo-Sun, Kim, Young-Soo, Choi, Sung-Hyun, Jin, Sung-Geun, Han, Kwang-Hun
• Granted Patent: US 8,619,704 B2
• Time in Patent Office: Days
• US Class Current: 370/318
• CPC Class Codes: H04L 12/12 Arrangements for remote connection or disconnection of substations or of equipment thereof
• CPC Class Codes: H04W 36/00 Hand-off or reselection arrangements
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/287 when the channel is in stand-by
• CPC Class Codes: H04W 68/00 User notification, e.g. alerting and paging, for incoming communication, change of service or the like
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

The present invention relates to a power saving in a wireless local area network including a plurality of access points providing at least one mobile station in each access point cell boundary with access service, the mobile station transits between an active mode and an idle mode. The power saving method includes grouping the access points into at least one paging group with a paging group boundary; determining if the a mobile station is in the idle mode in which the mobile station switches between an awake state and a doze state every predetermined time interval, or the active mode in which the mobile station is in the awake mode; and if the mobile station is in the idle mode enabling an idle handoff which occurs only when the mobile station crosses the paging group boundary. In the present invention, the handoff occurs when the mobile terminal crosses the paging group boundary but not the access point cell in the idle mode, resulting in reduction of power consumption.

Claims

1. A power saving method for wireless local area network including a plurality of access points providing at least one mobile station in each access point cell with access service, the mobile station transiting between an active mode and an idle mode, the method comprising the steps of:

grouping the access points into at least one paging group with a paging group boundary;

determining if a mobile station is in the idle mode in which the mobile station switches between an awake state and a doze state every predetermined time interval, or in the active mode in which the mobile station is in the awake state; and

if the mobile station is in the idle mode activating an idle handoff which occurs only when the mobile station crosses the paging group boundary.

2. The method of claim 1, wherein the group paging boundary is defined by the cells of the access points.

3. The method of claim 1, wherein the idle handoff is performed in a media access control level.

4. The method of claim 1 further comprising activating a regular handoff which occurs whenever the mobile station crosses the cell boundaries, if the mobile station is in the active mode.

5. The method of claim 4, wherein the regular handoff includes a media access control level operations.

6. The method of claim 5, wherein the regular handoff includes an Internet Protocol level operations.

7. The method of claim 4, wherein the step of activating the regular handoff comprises:

determining if the mobile station is paged in the awake state of the idle mode;

transiting to the active mode if the mobile station is paged.

8. The method of claim 7, wherein the step of activating the regular handoff further comprises:

determining if data to be transmitted is generated in the idle mode;

transiting to the active mode if the data is generated.

9. A power saving method for wireless communication system including a plurality of stationary stations providing at least one mobile station in each stationary station cell with access service, the mobile station transiting between an awake state and a doze state, the method comprises the steps of:

grouping the stationary stations into at least one paging group with a paging group boundary;

determining if the mobile station is in the doze state; and

if the mobile station is in the doze state performing a handoff only when the mobile station crosses the paging group boundary.

10. The method of claim 9, wherein the group paging boundary is defined by the cells of the access points.

11. The method of claim 9 further comprising performing a handoff when the mobile station crosses the stationary station cell boundary as well as the paging group boundary if the mobile station is in the awake state.

12. The method of claim 10, wherein the handoff is a media access control level handoff.

13. The method of claim 11, wherein the handoff is a media access control level handoff.

14. The method of claim 10, wherein the step of performing the handoff comprises:

determining if the mobile station is paged by the stationary station; and

performing an Internet Protocol level handoff if the mobile station is paged.

15. A power saving method for wireless communication system including a plurality of stationary stations providing at least one mobile station in each stationary station cell boundary with access service, the mobile station transiting between an awake state and a doze state, the method comprising the steps of:

grouping the stationary stations into at least one paging group with a paging group boundary;

determining if the a mobile station is in the doze state or the awake; and

if the mobile station is in the doze state enabling a handoff across the paging group boundary but not across the cell boundary.

16. The method of claim 15, wherein the group paging boundary is defined by the cells of the access points.

17. The method of claim 15 further comprising enabling the handoff across both the cell boundary and the paging group boundary if the mobile station is in the awake state.

18. The method of claim 17, wherein the step of performing the handoff across the paging group boundary but not across the cell boundary comprises:

determining if the mobile station is paged by the stationary station; and

transiting from the doze state to the awake state if the mobile station is paged.

19. The method of claim 18, the step of performing the handoff across the paging group boundary but not across the cell boundary further comprises:

determining if the mobile station has data to transmit; and

transiting from the doze state to awake state if the mobile station has the data to transmit.

20. The method of claim 19, wherein the handoff in the doze state is a media access control level handoff.

21. The method of claim 19, wherein the handoff in the awake state is an Internet Protocol level handoff.

22. The method of claim 19, wherein the handoff is a media access control level handoff and an Internet Protocol level handoff in the respective doze and awake states.