AUTOMATING RADIO ENABLEMENT TO FACILITATE POWER SAVING

• US 20110317600A1
• Filed: 06/25/2010
• Published: 12/29/2011
• Est. Priority Date: 06/25/2010
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: THOMSON, Allan, TORRES, Esteban
• Granted Patent: US 8,811,247 B2
• Time in Patent Office: Days
• US Class Current: 370/311
• CPC Class Codes: H04B 1/005 adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges
• CPC Class Codes: H04L 12/12 Arrangements for remote connection or disconnection of substations or of equipment thereof
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0235 where the received signal is a power saving command
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

In an example embodiment, there is disclosed herein an apparatus comprising a wireless transceiver and a controller coupled to the wireless transceiver and configured to receive data via the wireless transceiver. The controller operates the wireless transceiver at a first power save state where the wireless transceiver can receive a frame but other circuits are de-energized. The controller is responsive to the wireless transceiver receiving a frame while the wireless transceiver is in a first power state to determine whether the frame is a predefined wakeup frame. The controller provides additional power to the wireless transceiver responsive to determining the frame is a predefined wakeup frame.

Claims

1. An apparatus, comprising

a wireless transceiver;

a controller coupled to the wireless transceiver and configured to receive data via the wireless transceiver;

wherein the controller operates the wireless transceiver in a first power state where the wireless transceiver can receive a frame but not send a frame;

wherein the controller is responsive to the wireless transceiver receiving a frame while the wireless transceiver is in the first power state to determine whether the frame is a predefined wakeup frame;

wherein the controller provides additional power to the wireless transceiver responsive to determining the frame is a predefined wakeup frame; and

wherein the controller determines the frame is the predefined wakeup frame based on an address contained within the frame.

2. The apparatus of claim 1, wherein the address of the frame includes a destination address;

and

wherein the controller determines the frame is a predefined wakeup frame by determining whether the destination address of the frame is a predefined multicast destination address.

3. The apparatus of claim 1, wherein the wireless transceiver is configured to operate on a plurality of wireless channels;

and

wherein the wireless transceiver operates on a selected one of the plurality of wireless channels to listen for the predefined wakeup frame.

4. The apparatus of claim 1, wherein the controller switches the wireless transceiver to a second power state for a predefined interval.

5. The apparatus of claim 1, wherein the controller switches on a transmitter associated with the wireless transceiver responsive to determining the predefined wakeup frame was received;

and

wherein the controller attempts to associate with a network via the wireless transceiver.

6. The apparatus of claim 5, wherein the controller returns the wireless transceiver to the first state responsive to not successfully associating with the network within a specified time period.

7. The apparatus of claim 1, wherein the controller obtains access point and channel data for at least one access point from the predefined wakeup frame.

8. The apparatus of claim 7, wherein the controller switches the wireless transceiver to a channel obtained from channel data obtained from the predefined wakeup frame.

9. The apparatus of claim 1, wherein the controller provides the additional power to a decryption circuit associated with the wireless transceiver.

10. The apparatus of claim 9, wherein the controller determines via the decryption circuit whether the received frame has a valid signature corresponding to a predefined wakeup frame for one of a group consisting of an access point sending the wakeup frame and a network associated with the access point.

11. The apparatus of claim 10, wherein the controller provides power to a transmit circuit associated with the wireless transceiver responsive to determining that the received frame has a signature corresponding to a predefined wakeup frame.

12. The apparatus of claim 1, wherein the controller provides additional power to the wireless transceiver responsive to determining a predefined sequence of wakeup frames were received.

13. The apparatus of claim 1, further comprising a second wireless transceiver;

wherein the second wireless transceiver operates while the first wireless transceiver is in a power save mode.

14. A method, comprising:

operating a first wireless transceiver;

periodically switching the second wireless transceiver between a first power state and a second power state, where the wireless transceiver can receive a frame while in the first power state but not while in the second power state;

receiving a frame via the second wireless transceiver while in the first power state;

determining whether the frame is a predefined wakeup frame from a network affiliated with a network in communication with the first wireless transceiver; and

providing power to at least one additional circuit associated with the second wireless transceiver responsive to determining the frame is a predefined wakeup frame.

15. The method of claim 14, wherein the determining whether a frame is a predefined wakeup frame comprises determining whether the frame is addressed to a predefined multicast address;

wherein providing power to at least one additional circuit comprises providing power to a decryption circuit;

determining whether the frame is a predefined wakeup frame further comprises validating a signature in the frame by the decryption circuit; and

providing power to at least one additional circuit further comprises providing power to a transmitter associated with the second wireless transceiver responsive to validating the signature in the frame.

16. The method of claim 14, wherein receiving a frame via the second wireless transceiver while in the first power state further comprises receiving a plurality of frames;

wherein determining whether the frame is a predefined wakeup frame from a network affiliated with a network in communication with the first wireless transceiver further comprises determining whether the plurality of frames contains a predefined sequence of frames; and

wherein providing power to at least one additional circuit associated with the second wireless transceiver is responsive to determining the plurality of frames contained a predefined sequence of frames.

17. An apparatus, comprising:

a wireless transceiver;

a controller coupled to the wireless transceiver;

wherein the controller periodically generates a predefined wakeup frame to be transmitted by the wireless transceiver; and

wherein the predefined wakeup frame is transmitted at a higher data rate than a lowest, default data rate.

18. An apparatus according to claim 18, wherein the wireless transceiver sends and receives data on a first channel;

and

wherein the predefined wakeup frame is sent on a second channel

19. The apparatus according to claim 18, wherein the controller puts a predefined multicast address into the predefined wakeup frame.

20. The apparatus according to claim 18, wherein the controller puts a predefined signature into the predefined wakeup frame.