Wireless LAN power savings

• US 7,881,755 B1
• Filed: 02/09/2006
• Issued: 02/01/2011
• Est. Priority Date: 05/26/2005
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Inventors: Goel, Sandesh, Mishra, Partho
• Primary Examiner(s): Rao; Seema S
• Assistant Examiner(s): HUYNH, KHOA B
• Application Number:
  US11/351,232
• Time in Patent Office: 1,818 Days
• Field of Search: 370/431, 370/463, 370/310, 370/311, 455/73, 455/550.1, 455/572, 455/574, 455/91, 455/127.1, 455/127.5, 455/130, 455/334, 455/343.1, 455/343.2, 455/343.3, 455/343.4, 455/343.5, 327/524, 327/530, 327/544, 340/500, 340/531, 340/539.1, 340/539.3, 340/825, 340/825.36, 340/7.2, 340/7.32, 713/310, 713/320, 713/321, 713/322, 713/323, 713/324, 713/330, 713/340
• US Class Current: 455/574
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0225 using monitoring of external events, e.g. the presence of a signal
• 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 52/0274 by switching on or off the equipment or parts thereof
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A network device includes a base band processor (BBP) receiver to detect a frame in a signal. A media access controller (MAC) receiver identifies a destination address in the frame. A power management module transitions the BBP receiver to an active mode based on an estimated energy level of the signal before transitioning the MAC receiver, a processor, a MAC transmitter, and a BBP transmitter to the active mode; transitions the MAC receiver to the active mode when the frame is present after transitioning the BBP receiver to the active mode and before transitioning the processor, the MAC transmitter, and the BBP transmitter to the active mode; and transitions the processor to the active mode based on the destination address after transitioning the BBP receiver and the MAC receiver to the active mode and before transitioning the MAC transmitter and the BBP transmitter to the active mode.

Claims

1. A wireless network device comprising:

a base band processor (BBP) including

a BBP receiver configured to determine whether a signal includes a frame, and

a BBP transmitter;

a media access controller (MAC) configured to communicate with the BBP, wherein the MAC includes

a MAC receiver configured to identify a destination address in the frame, and

a MAC transmitter;

a processor configured to communicate with the MAC; and

a power management module configured to

transition the BBP receiver to an active mode based on an estimated energy level of the signal,

wherein the power management module is configured to transition the BBP receiver to the active mode before transitioning the MAC receiver, the processor, the MAC transmitter, and the BBP transmitter to the active mode;

transition the MAC receiver to the active mode when the frame is present,

wherein the power management module is configured to transition the MAC receiver to the active mode (i) after transitioning the BBP receiver to the active mode and (ii) before transitioning the processor, the MAC transmitter, and the BBP transmitter to the active mode; and

transition the processor to the active mode based on the destination address,

wherein the power management module is configured to transition the processor to the active mode (i) after transitioning the BBP receiver and the MAC receiver to the active mode and (ii) before transitioning the MAC transmitter and the BBP transmitter to the active mode.

2. The wireless network device of claim 1, further comprising a radio frequency (RF) receiver configured to

receive the signal,

communicate the signal to the BBP, and

estimate the energy level.

3. The wireless network device of claim 2, wherein the power management module is configured to periodically transition the RF receiver to the active mode based on a target beacon transmission time.

4. The wireless network device of claim 1, wherein the power management module is configured to transition the BBP receiver to the active mode when the energy level is greater than a predetermined energy threshold.

5. The wireless network device of claim 3, wherein the power management module is configured to transition the RF receiver to an inactive mode when the energy level is less than a predetermined energy threshold.

6. The wireless network device of claim 2, wherein the power management module is configured to transition the BBP receiver and the RF receiver to an inactive mode when the signal does not include the frame.

7. The wireless network device of claim 1, wherein the power management module is configured to transition the processor to the active mode when the destination address matches a predetermined address.

8. The wireless network device of claim 3, wherein the power management module is configured to transition the MAC receiver, the BBP receiver, and the RF receiver to an inactive mode when the destination address does not match a predetermined address.

9. The wireless network device of claim 1, wherein the power management module is configured to transition the MAC transmitter to the active mode when the processor transitions to the active mode.

10. The wireless network device of claim 9, wherein the power management module is configured to transition the BBP transmitter to the active mode when the MAC transmitter transitions to the active mode.

11. The wireless network device of claim 10, further comprising an RF transmitter configured to transmit an RF signal, wherein the power management module is configured to transition the RF transmitter to the active mode when the BBP transmitter transitions to the active mode.

12. A method of powering up a network device, the method comprising:

estimating an energy level of a signal;

determining whether the signal includes a frame;

identifying a destination address in the frame; and

transitioning a receiver of a base band processor (BBP receiver) to an active mode based on the energy level;

transitioning a receiver of a media access controller (MAC receiver) to the active mode when the frame is present;

transitioning a processor to the active mode based on the destination address;

transitioning the BBP receiver to the active mode before transitioning the MAC receiver, the processor, a MAC transmitter, and a BBP transmitter to the active mode;

transitioning the MAC receiver to the active mode (i) after transitioning the BBP receiver to the active mode and (ii) before transitioning the processor, the MAC transmitter, and the BBP transmitter to the active mode; and

transitioning the processor to the active mode (i) after transitioning the BBP receiver and the MAC receiver to the active mode and (ii) before transitioning the MAC transmitter and the BBP transmitter to the active mode.

13. The method of claim 12, further comprising transitioning a radio frequency (RF) receiver to the active mode based on a target beacon transmission time.

14. The method of claim 13, further comprising transitioning the BBP receiver to the active mode when the energy level is greater than a predetermined energy threshold.

15. The method of claim 13, further comprising transitioning the RF receiver to an inactive mode when the energy level is less than a predetermined energy threshold.

16. The method of claim 14, further comprising transitioning the BBP receiver and the RF receiver to an inactive mode when the signal does not include the frame.

17. The method of claim 12, further comprising transitioning the processor to the active mode when the destination address matches a predetermined address.

18. The method of claim 13, further comprising transitioning the MAC receiver, the receiver of the BBP, and the RF receiver to an inactive mode when the destination address does not match a predetermined address.

19. The method of claim 12, further comprising transitioning the MAC transmitter to the active mode when the processor transitions to the active mode.

20. The method of claim 19, further comprising transitioning a BBP transmitter to the active mode when the MAC transmitter transitions to the active mode.

21. The method of claim 20, further comprising transitioning a RF transmitter to the active mode when the BBP transmitter transitions to the active mode.

22. A network device comprising:

a radio frequency (RF) receiver configured to

prior to receiving a beacon, switch to an active mode to detect an energy of a RF signal, and

switch to an inactive mode if the energy of the RF signal is less than a predetermined threshold;

a physical layer (PHY) receiver configured to

switch to the active mode to detect a preamble in a frame of the RF signal if (i) the RF receiver is in the active mode and (ii) the energy of the RF signal is greater than or equal to the predetermined threshold, and

switch to the inactive mode if the preamble is invalid,

wherein the RF receiver is further configured to switch to the inactive mode if the preamble is invalid;

a medium access controller (MAC) receiver configured to

switch to the active mode to detect a destination address in the frame if (i) the RF receiver and the PHY receiver are in the active mode and (ii) the preamble is valid, and

switch to the inactive mode if the destination address is invalid,

wherein the RF receiver and the PHY receiver are further configured to switch to the inactive mode if the destination address is invalid;

a processor configured to

switch to the active mode to determine whether to transmit a response to the frame if (i) the RF receiver, the PHY receiver, and the MAC receiver are in the active mode and (ii) the destination address is valid, and

switch to the inactive mode if the processor determines not to transmit the response,

wherein the RF receiver, the PHY receiver, and the MAC receiver are further configured to switch to the inactive mode if the processor determines not to transmit the response; and

a MAC transmitter, a PHY transmitter, and a RF transmitter each configured to

switch to the active mode to transmit the response if (i) the RF receiver, the PHY receiver, the MAC receiver, and the processor are in the active mode and (ii) the processor decides to transmit the response, and

switch to the inactive mode after transmitting the response,

wherein the RF receiver, the PHY receiver, the MAC receiver, and the processor are further configured to switch to the inactive mode after the response is transmitted.