REDUCING POWER CONSUMPTION IN A WIRELESS COMMUNICATION SYSTEM

• US 20120263084A1
• Filed: 04/18/2012
• Published: 10/18/2012
• Est. Priority Date: 04/18/2011
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: Liu, Yong, Banerjea, Raja
• Granted Patent: US 9,374,782 B2
• 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

After transitioning a network interface of a first wireless communication device from a low power state to an active state, transmitting a request for a second wireless communication device to transmit data for the first wireless communication device that is buffered at the second wireless communication device. An indication of whether there is data for the first wireless communication device buffered at second wireless communication device is received. When there is data for the first wireless communication device buffered at second wireless communication device, data for the first wireless communication device that was buffered at the second wireless communication device is received from the second wireless communication device.

Claims

1. A method, comprising:

transitioning a network interface of a first wireless communication device from a low power state to an active state, wherein

when the network interface is in the low power state, the network interface is unable to at least one of (i) transmit signals via a wireless communication medium and (ii) receive signals via the wireless communication medium, and

when the network interface is in the active state, the network interface is capable of both (i) transmitting signals via the wireless communication medium and (ii) receiving signals via the wireless communication medium;

after transitioning the network interface to the active state, determining whether a communication channel is available;

generating a data unit that includes a request for a second wireless communication device to transmit to the first wireless communication device data for the first wireless communication device that is buffered at the second wireless communication device;

in response to determining that the communication channel is available, transmitting to the second wireless communication device, via the communication channel, the data unit that includes the request;

receiving from the second wireless communication device, via the communication channel, an indication of whether there is data for the first wireless communication device buffered at second wireless communication device; and

receiving, from the second wireless communication device and when there is data for the first wireless communication device buffered at second wireless communication device, data for the first wireless communication device that was buffered at the second wireless communication device.

2. A method according to claim 1, wherein generating the data unit that includes the request comprises generating the data unit to include data for transmission to the second wireless communication device.

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

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

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

6. A method according to claim 1, further comprising transitioning the network interface of the first wireless communication device from the active state to the low power state in response to determining, based on the indication of whether there is data for the first wireless communication device buffered at second wireless communication device, that there is not data for the first wireless communication device buffered at second wireless communication device.

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

determining a time at which the network interface of the first wireless communication device is to transition from the low power state to the active state in order to receive data for the first wireless communication device that was buffered at the second wireless communication device;

transitioning the network interface of the first wireless communication device from the active state to the low power state after receiving the indication of whether there is data for the first wireless communication device buffered at second wireless communication device;

at the determined time, transitioning the network interface of the first wireless communication device from the low power state to the active state; and

receiving, from the second wireless communication device and after the determined time, data for the first wireless communication device that was buffered at the second wireless communication device.

8. A method according to claim 7, further comprising:

after the determined time, receiving a beacon data unit from the second wireless communication device;

processing the beacon data unit to determine a subsequent time at which the network interface of the first wireless communication device is to transition from the low power state to the active state in order to receive data for the first wireless communication device that was buffered at the second wireless communication device;

transitioning the network interface of the first wireless communication device from the active state to the low power state after receiving the beacon data unit;

at the determined subsequent time, transitioning the network interface of the first wireless communication device from the low power state to the active state; and

receiving, from the second wireless communication device and after the determined subsequent time, data for the first wireless communication device that was buffered at the second wireless communication device.

9. A method according to claim 1, wherein between (i) transitioning the network interface from the low power state to the active state and (ii) transmitting to the second wireless communication device the data unit that includes the request, the second wireless communication device does not transmit a beacon data unit.

10. A method according to claim 1, wherein between (i) transmitting to the second wireless communication device the data unit that includes the request and (ii) receiving data for the first wireless communication device that was buffered at the second wireless communication device, the network interface of the first wireless communication device does not reenter the low power mode.

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

a network interface configured to

transition the network interface from a low power state to an active state, wherein

when the network interface is in the low power state, the network interface is unable to at least one of (i) transmit signals via a wireless communication medium and (ii) receive signals via the wireless communication medium, and

when the network interface is in the active state, the network interface is capable of both (i) transmitting signals via the wireless communication medium and (ii) receiving signals via the wireless communication medium;

after transitioning the network interface to the active state, determine whether a communication channel is available;

generate a data unit that includes a request for a second communication device to transmit to the first communication device data for the first communication device that is buffered at the second communication device;

in response to determining that the communication channel is available, transmit to the second communication device, via the communication channel, the data unit that includes the request;

receive from the second communication device, via the communication channel, an indication of whether there is data for the first communication device buffered at second communication device; and

receive, from the second communication device and when there is data for the first communication device buffered at second communication device, data for the first communication device that was buffered at the second communication device.

12. A first communication device according to claim 11, wherein the network interface is configured to generate the data unit that includes the request to also include data for transmission to the second wireless communication device.

13. A first communication device according to claim 11, wherein the network interface is configured to process an acknowledgment data unit that acknowledges receipt of the data unit that includes the request, wherein the acknowledgement data unit is received from the second wireless communication device, via the communication channel.

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

15. A first communication device according to claim 13, wherein, when there is data for the first wireless communication device buffered at second wireless communication device, the acknowledgment data unit includes data for the first wireless communication device buffered at second wireless communication device.

16. A first communication device according to claim 11, wherein the network interface is configured to transition the network interface from the active state to the low power state in response to determining, based on the indication of whether there is data for the first wireless communication device buffered at second wireless communication device, that there is not data for the first wireless communication device buffered at second wireless communication device.

17. A first communication device according to claim 11, wherein the network interface is configured to, when there is data for the first wireless communication device buffered at second wireless communication device:

determine a time at which the network interface is to transition from the low power state to the active state in order to receive data for the first wireless communication device that was buffered at the second wireless communication device;

transition the network interface from the active state to the low power state after receiving the indication of whether there is data for the first wireless communication device buffered at second wireless communication device;

at the determined time, transition the network interface from the low power state to the active state; and

receive, from the second wireless communication device and after the determined time, data for the first wireless communication device that was buffered at the second wireless communication device.

18. A first communication device according to claim 17, wherein the network interface is configured to:

after the determined time, receive a beacon data unit from the second wireless communication device;

process the beacon data unit to determine a subsequent time at which the network interface of the first wireless communication device is to transition from the low power state to the active state in order to receive data for the first wireless communication device that was buffered at the second wireless communication device;

transition the network interface from the active state to the low power state after receiving the beacon data unit;

at the determined subsequent time, transition the network interface from the low power state to the active state; and

receive, from the second wireless communication device and after the determined subsequent time, data for the first wireless communication device that was buffered at the second wireless communication device.

19. A first communication device according to claim 11, wherein between (i) transitioning the network interface from the low power state to the active state and (ii) transmitting to the second wireless communication device the data unit that includes the request, the second wireless communication device does not transmit a beacon data unit.

20. A first communication device according to claim 11, wherein between (i) transmitting to the second wireless communication device the data unit that includes the request and (ii) receiving data for the first wireless communication device that was buffered at the second wireless communication device, the network interface of the first wireless communication device does not reenter the low power mode.