POWER OPTIMIZED STATION CONNECTION MANAGER IN IEEE 802.11 TYPE STATIONS

• US 20090016296A1
• Filed: 07/09/2007
• Published: 01/15/2009
• Est. Priority Date: 07/09/2007
• Status: Active Grant

• Current Assignee: Wipro Limited
• Original Assignee: Wipro Limited
• Inventors: Fleter, Franck, Jechoux, Bruno
• Granted Patent: US 8,467,348 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 52/0206 in access points, e.g. base stations access point devices per se H04W88/08
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0219 where the power saving management affects multiple terminals
• CPC Class Codes: H04W 52/0235 where the received signal is a power saving command
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method of managing a mobile station (e.g., IEEE 802.11 station) having a serving BSS, uses a station connection manger and initially maintains a default idle stable state with minimum power to receive incoming calls. While idle, the station periodically polls and scans a detected BSS (Access Point) to detect messages using DTIM (Delivery Traffic Indication Message). A null frame sent, triggers corresponding frame transmission at an Access Point. If the null frame is acknowledged, the station switches to the active state until end of packet exchange. With no null frame acknowledged, scanning is resumed to update a BSS list prior to joining a newly found BSS via authentication and association states. When no candidate BSS is found, a time out period is used before next polling. After the last message frame is transmitted, the station resumes the default idle state. The station manager conserves battery power in the station.

Claims

1. A method of managing a mobile station which is associated with a serving BSS and interacting with a potential candidate BSS for handoff while roaming, comprising the steps of:

using an autonomous station connection manger and initially maintaining a default idle stable state at a minimum level of activity and power consumption sufficient to receive an incoming call;

while in said idle stable state, periodically polling and scanning a detected BSS (Access Point) to detect relevant messages using DTIM (Delivery Traffic Indication Message);

sending a triggering frame to trigger corresponding frame transmission at an Access Point;

using the trigger to verify if the triggering frame is acknowledged, and then switching the mobile station to an active state until end of packet exchange as managed internally by said station connection manager; and

,

if the triggering frame is not acknowledged, resuming scanning to update a BSS list prior to joining a newly found BSS via authentication and association states.

2. The method as in claim 1 wherein the triggering frame is a null frame, including the step of configuring the station connection manager to control steps of initiating re-authentication and re-association for handoff as needed.

3. The method as in claim 1 wherein said triggering frame is chosen from a null frame and a PS-Poll frame, the method including the step of continually but selectively maintaining and monitoring authentication and association, and hence receiving incoming calls including SIP proxy, and for supporting push services.

4. The method as in claim 3 wherein said push services selectively include chat session, SMS and MMS.

5. The method as in claim 1 wherein said step of maintaining said active status is done on a need basis.

6. The method as in claim 1 including the step of initiating handoff and re-association on a need basis.

7. The method as in claim 2, including the step of the station connection manager selectively doing periodic polling of incoming calls and push messages.

8. The method as in claim 7 including the step of using a time out period when no candidate BSS is found for hand off, before next polling.

9. The method as in claim 1 including the step wherein the station connection manager controls station power modes between said idle state and said and active state.

10. The method as in claim 9, wherein said mobile station is battery powered, and the BSSs may selectively comprise APs, including the step of using an association authentication keep alive algorithm which adapts to AP implantation inactivity time out, using a timer rampup procedure.

23. A computer readable medium encoded with data/instruction which when executed by a computing platform results in execution of a method as in claim 1.

11. A method of managing an IEEE 802.11 type station which is associated with a serving BSS, said station having a stable default idle state and a stable active state, said method comprising the steps of:

using an autonomous station connection manger and scanning as needed;

to perform said scanning, selectively probing said serving BSS for monitoring and maintaining connection status through a triggering frame transmission and trigger re-authorization; and

,

minimizing power consumption by controlling said probing and monitoring, and using an estimated timeout to set up the probing and monitoring.

12. The method as in claim 11 wherein said triggering frame is chosen from a null frame and a PS-Poll frame, wherein the station connection manager is configured to control the steps of initiating re-authentication and re-association for handoff as needed.

13. The method as in claim 11 including the step of continually but selectively maintaining and monitoring authentication and association, and hence receiving incoming calls including SIP proxy, and for supporting push services.

14. The method as in claim 13 wherein said push services selectively include chat session, SMS and MMS.

15. The method as in claim 11 wherein said step of maintaining the connection status is done on a need basis.

16. The method as in claim 11 including the step of initiating handoff and re-association on a need basis.

17. The method as in claim 12, including the step of the station connection manager selectively doing periodic polling of incoming calls and push messages.

18. The method as in claim 17 including the step of using a time out period when no candidate BSS is found for hand off, before next scanning.

19. The method as in claim 11 including the step wherein the station connection manager controls station power modes between aid idle state and said active state.

20. The method as in claim 19, wherein said mobile station is battery powered, and the BSSs may selectively comprise APs, including the step of using an association authentication keep alive algorithm which adapt sto AP implantation inactivity time out, using a timer rampup procedure.

24. A computer readable medium encoded with data/instruction which when executed by a computing platform results in execution of a method as in claim 11.

21. A method of managing a mobile station which is associated with a serving BSS from a plurality of BSSs, wherein said mobile station is battery powered, and wherein the plurality of BSSs may selectively comprise APs, comprising the steps of:

using an autonomous station connection manger for selectively doing periodic polling and scanning of incoming calls and push messages;

to perform said scanning, selectively probing said serving BSS for monitoring and maintaining connection status through null-frame or data frame transmission and trigger re-authorization;

using a time out period when no candidate BSS is found for hand off, before next scanning;

using an association authentication keep alive algorithm which adapts to AP implantation inactivity time out, using a timer rampup procedure; and

,

including the step wherein the station connection manager is configured to control station power modes between a default stable idle mode and a stable active mode.

22. A method of managing a mobile station which is associated with a serving BSS, comprising the steps of:

using an autonomous station connection manger to maintain association of the mobile station with a serving BSS or Access Point, and initially maintaining a default idle stable state at a minimum level of activity and power consumption sufficient to receive an incoming call;

while in said idle state, maintaining adaptive polling of calls coming into the mobile station;

switching from said idle stable state to a stable active state until end of packet exchange in an incoming call as managed internally by said station connection manager; and

,

minimizing power consumption by controlling said polling and monitoring.