Discovery-phase power conservation

• US 9,288,764 B1
• Filed: 12/23/2009
• Issued: 03/15/2016
• Est. Priority Date: 12/31/2008
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Inventors: Banerjea, Raja, Goel, Sandesh, Kopikare, Milind
• Primary Examiner(s): Vu, Hoang-Chuong
• Application Number:
  US12/646,802
• Time in Patent Office: 2,274 Days
• Field of Search: 370/311, 370/318, 370/410, 370/426, 370/491, 370/496, 370/500, 370/522
• US Class Current: 1/1
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 52/0206 in access points, e.g. base stations access point devices per se H04W88/08
• CPC Class Codes: H04W 52/04 TPC
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

The present specification describes techniques and apparatuses that enable power conservation in a wireless network. In some cases these techniques and apparatuses enable power conservation during a discover phase and for a wireless network subject to a government mandate requiring a device of the network to passively search for radar transmission prior to establishing communication with another device of the network.

Claims

1. A method comprising:

conserving power during a discovery phase of a wireless local area network (WLAN) by;

reducing power at an access point of the WLAN for a reduced-power-usage period, the access point operating in a geographical region and at a frequency in which client stations operating in the geographical region and at the frequency are required to passively search for radar transmissions prior to transmitting at the frequency, the reduced power being insufficient to enable the access point to receive communication from a client station within a communication region of the access point, the reduced-power-usage period at the access point being configured to vary according to information received by the access point from one of the client stations indicating a radar search period for the client station; and

increasing power at the access point subsequent to expiration of the reduced-power-usage period, the power being increased for a reception period in which communication from the client station or another client station within the communication region of the access point can be received.

2. The method of claim 1, wherein the client stations are required to passively search for radar transmissions for the radar search period prior to transmitting at the frequency.

3. The method of claim 2, wherein radar search period is sixty seconds and the frequency is in the five Giga-Hertz band.

4. The method of claim 2, wherein reducing power and increasing power are performed multiple times during the radar search period.

5. The method of claim 1, further comprising, subsequent to expiration of the reduced-power-usage period, transmitting the reception period.

6. The method of claim 5, wherein the transmitting the reception period comprises transmitting a beacon, the beacon being part of a handshake protocol of the discovery phase.

7. The method of claim 1, wherein the method is performed by a System-on-Chip in the access point.

8. A method comprising:

transmitting, from an access point of a wireless local area network (WLAN), a first beacon, the first beacon to discover a client station with which to establish communication;

maintaining power usage at the access point for a first reception period, the power usage sufficient to enable receiving a probe request from the client station;

responsive to not receiving the probe request from the client station during the first reception period and prior to establishing a communication with the client station, reducing power usage at the access point after the first reception period ends and for a reduced-power-usage period, the reduced-power-usage period insufficient to enable receiving the probe request from the client station, the reduced-power-usage period at the access point being configured to vary according to information received by the access point from the client station indicating a radar search period for the client station;

transmitting, from the access point, a second beacon, the second beacon to discover the client station;

maintaining power usage at the access point for a second reception period, the power usage sufficient to enable receiving the probe request from the client station; and

responsive to receiving the probe request from the client station during the second reception period, responding to the probe request with a probe response, the probe response part of establishing the communication with the client station.

9. The method of claim 8, wherein:

transmitting the first beacon includes transmitting the first reception period, the first reception period indicating a first amount of time that the access point is capable of receiving the probe request from the client station; and

transmitting the second beacon includes transmitting the second reception period, the second reception period indicating a second amount of time that the access point is capable of receiving the probe request from the client station.

10. The method of claim 9, wherein the first reception period and the second reception period are identical amounts of time.

11. The method of claim 9, wherein the first reception period and the second reception period are different amounts of time determined based, at least in part, on one or more factors.

12. The method of claim 11, wherein the one or more factors includes a history of how quickly the access point receives the probe request from the client station.

13. The method of claim 8, wherein the client station is required to refrain from transmitting the probe request during the radar search period.

14. The method of claim 13, further comprising:

receiving, at the access point, an indication that the radar search period has changed; and

responsive to receiving the indication, altering the reduced-power-usage period.

15. The method of claim 8, wherein the client station is permitted to transmit the probe request if the client station does not receive radar transmissions during the radar search period.

16. The method of claim 8, wherein the radar search period is sixty seconds, and the probe request is transmitted in a five Giga-Hertz range.

17. The method of claim 8, wherein the first and second beacons are part of a handshake protocol of a discovery phase.

18. The method of claim 8, wherein the access point is a printing device and the client station is a personal computing device.

19. The method of claim 8, further comprising, prior to transmitting the second beacon:

transmitting, from the access point, a third beacon, the third beacon to discover the client station;

maintaining power usage at the access point for a third reception period, the power usage sufficient to enable receiving the probe request from the client station; and

responsive to not receiving the probe request from the client station during the third reception period, reducing power usage at the access point after the third reception period ends and for a second reduced-power-usage period, the second reduced-power-usage period insufficient to enable receiving the probe request from the client station.

20. The method of claim 8, wherein the method is performed by a System-on-Chip in the access point.