REDUCING POWER CONSUMPTION IN A WIRELESS COMMUNICATION SYSTEM

• US 20120263085A1
• Filed: 04/18/2012
• Published: 10/18/2012
• Est. Priority Date: 04/18/2011
• Status: Abandoned Application

• Current Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: Liu, Yong, Banerjea, Raja
• Application Number:
  US13/450,220
• Publication Number:
  US 20120263085A1
• Time in Patent Office: Days
• US Class Current: 370/311
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

An indication that a network interface of a wireless communication device is in a low power state is received. Prior to receiving an indication that the network interface of the wireless communication device is no longer in the low power state, a data unit is received from the wireless communication device, wherein the data unit includes a request to transmit to the wireless communication device data for the wireless communication device that has been buffered while the wireless communication device is in the low power state. Responsive to the request, an indication of whether there is buffered data for the wireless communication device is transmitted. Additionally, when it is determined that there is buffered data for the wireless communication device, buffered data is transmitted to the wireless communication device.

Claims

1. A method, comprising:

receiving, at a first wireless communication device, an indication that a network interface of a second wireless communication device is in a low power state in which the network interface is unable to receive signals transmitted by the first wireless communication device;

buffering, at the first wireless communication device, data for the second wireless communication device in response to receiving the indication that the network interface of the second wireless communication device is in a low power state;

prior to receiving an indication that the network interface of the second wireless communication device is no longer in the low power state, receiving, at the first wireless communication device, a data unit from the second wireless communication device, wherein the data unit includes a request to transmit to the second wireless communication device data for the second wireless communication device that is buffered at the first wireless communication device;

determining, at the first wireless communication device, whether there is data for the second wireless communication device that is buffered at the first wireless communication device;

transmitting, with the first wireless communication device and to the second wireless communication device, responsive to the request, an indication of whether there is data for the second wireless communication device that is buffered at the first wireless communication device; and

when it is determined that there is data for the second wireless communication device that is buffered at the first wireless communication device, transmitting, with the first wireless communication device and to the second wireless communication device, data for the second wireless communication device that is buffered at the first wireless communication device.

2. A method according to claim 1, wherein the data unit from the second wireless communication device that includes the request also includes data for the first wireless communication device.

3. A method according to claim 1, further comprising transmitting to the second wireless communication device an acknowledgment data unit that acknowledges receipt of the data unit from the second wireless communication device.

4. A method according to claim 3, wherein the acknowledgment data unit includes the indication of whether there is data for the second wireless communication device that is buffered at the first wireless communication device.

5. A method according to claim 3, wherein, when there is data for the second wireless communication device buffered at the first wireless communication device, the acknowledgment data unit includes data for the second wireless communication device that was buffered at the first wireless communication device.

6. A method according to claim 1, wherein determining whether there is data for the second wireless communication device that is buffered at the first wireless communication device comprises analyzing a bitmap stored in a memory of the first wireless communication device, wherein

one bit in the bitmap corresponds to the second wireless communication device, and

the one bit indicates whether there is data for the second wireless communication device that is buffered at the first wireless communication device.

7. A method according to claim 1, wherein transmitting the indication of whether there is data for the second wireless communication device that is buffered at the first wireless communication device comprises transmitting at least a portion of a bitmap stored in a memory of the first wireless communication device, wherein

one bit in the bitmap corresponds to the second wireless communication device, and

the one bit indicates whether there is data for the second wireless communication device that is buffered at the first wireless communication device.

8. A method according to claim 1, further comprising:

analyzing a bitmap stored in a memory of the first wireless communication device with regard to an identifier of the second communication device to generate a reduced size bitmap, wherein the bitmap indicates whether there are data for a plurality of communication devices buffered at the first wireless communication device; and

transmitting the indication of whether there is data for the second wireless communication device that is buffered at the first wireless communication device comprises transmitting the reduced size bitmap.

9. A method according to claim 1, further comprising, when it is determined that there is data for the second wireless communication device that is buffered at the first wireless communication device, transmitting, with the first wireless communication device and to the second wireless communication device, an indication of a delay time associated with when the first wireless communication device will be ready to transmit data for the second wireless communication device that is buffered at the first wireless communication device.

10. A method according to claim 9, wherein the delay time corresponds to a next beacon data unit to be transmitted by the first wireless communication device.

11. A method according to claim 1, further comprising, when it is determined that there is data for the second wireless communication device that is buffered at the first wireless communication device:

determining a schedule for transmitting data for the second wireless communication device that is buffered at the first wireless communication device; and

transmitting, with the first wireless communication device and to the second wireless communication device, an indication of the schedule.

12. A method according to claim 1, further comprising transmitting, with the first wireless communication device and to the second wireless communication device, responsive to the request, one or more of

(i) information to facilitate the second wireless communication device to determine when the first wireless communication device will transmit broadcast and/or multicast data units for the second wireless communication device,

(ii) a timestamp, and

(iii) information regarding changes to parameters for communication within a basis service set (BSS).

20. A first communication device according to claim 3, wherein the network interface is configured to

analyze a bitmap stored in a memory of the first wireless communication device with regard to an identifier of the second communication device to generate a reduced size bitmap, wherein the bitmap indicates whether there are data for a plurality of communication devices buffered at the first wireless communication device, and

transmit the reduced size bitmap to the second wireless communication device.

13. A first communication device for use in a wireless communication network, the first communication device comprising:

a network interface configured to

buffer data for a second wireless communication device in response to receiving an indication from the second wireless communication device that a network interface of the second wireless communication device is in a low power state in which the network interface is unable to receive signals transmitted by the first wireless communication device,

determine whether there is data for the second wireless communication device that is buffered at the first wireless communication device;

transmit to the second wireless communication device, responsive to a data unit received from the second wireless communication device and prior to receiving an indication that the network interface of the second wireless communication device is no longer in the low power state, an indication of whether there is data for the second wireless communication device that is buffered at the first wireless communication device, wherein the data unit that includes a request to transmit to the second wireless communication device data for the second wireless communication device that is buffered at the first wireless communication device, and

when it is determined that there is data for the second wireless communication device that is buffered at the first wireless communication device, transmit, to the second wireless communication device, data for the second wireless communication device that is buffered at the first wireless communication device.

14. A first communication device according to claim 13, wherein the data unit from the second wireless communication device that includes the request also includes data for the first wireless communication device.

15. A first communication device according to claim 13, wherein the network interface is configured to transmit to the second wireless communication device an acknowledgment data unit that acknowledges receipt of the data unit from the second wireless communication device.

16. A first communication device according to claim 13, wherein the acknowledgment data unit includes the indication of whether there is data for the second wireless communication device that is buffered at the first wireless communication device.

17. A first communication device according to claim 13, wherein the network interface is configured to, when there is data for the second wireless communication device buffered at the first wireless communication device, generate the acknowledgment data unit to include data for the second wireless communication device that was buffered at the first wireless communication device.

18. A first communication device according to claim 13, wherein the network interface is configured to analyze a bitmap stored in a memory of the first wireless communication device to determine whether there is data for the second wireless communication device that is buffered at the first wireless communication device, wherein

one bit in the bitmap corresponds to the second wireless communication device, and

the one bit indicates whether there is data for the second wireless communication device that is buffered at the first wireless communication device.

19. A first communication device according to claim 13, wherein the network interface is configured to transmit at least a portion of a bitmap stored in a memory of the first wireless communication device as the indication of whether there is data for the second wireless communication device that is buffered at the first wireless communication device, wherein

one bit in the bitmap corresponds to the second wireless communication device, and

the one bit indicates whether there is data for the second wireless communication device that is buffered at the first wireless communication device.

21. A first communication device according to claim 13, wherein the network interface is configured to, when it is determined that there is data for the second wireless communication device that is buffered at the first wireless communication device, transmit to the second wireless communication device an indication of a delay time associated with when the first wireless communication device will be ready to transmit data for the second wireless communication device that is buffered at the first wireless communication device.

22. A first communication device according to claim 21, wherein the delay time corresponds to a next beacon data unit to be transmitted by the first wireless communication device.

23. A first communication device according to claim 13, wherein the network interface is configured to, when it is determined that there is data for the second wireless communication device that is buffered at the first wireless communication device:

determine a schedule for transmitting data for the second wireless communication device that is buffered at the first wireless communication device, and

transmit to the second wireless communication device an indication of the schedule.

24. A first communication device according to claim 13, wherein the network interface is configured to

transmit, responsive to the request, one or more of

(i) information to facilitate the second wireless communication device to determine when the first wireless communication device will transmit broadcast and/or multicast data units for the second wireless communication device,

(ii) a timestamp, and

(iii) information regarding changes to parameters for communication within a basis service set (BSS).