Link margin notification using return frame

• US 20050030976A1
• Filed: 06/30/2004
• Published: 02/10/2005
• Est. Priority Date: 06/12/2002
• Status: Active Grant

• Current Assignee: Intellectual Ventures I LLC (Intellectual Ventures LLC)
• Original Assignee: Globespan Virata, Inc.
• Inventors: Wentink, Menzo
• Granted Patent: US 7,933,293 B2
• Time in Patent Office: Days
• US Class Current: 370/473
• CPC Class Codes: H04B 7/2126 using a reference station
• CPC Class Codes: H04W 52/48 during retransmission after error or non-acknowledgment
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user

Abstract

Disclosed herein are techniques for power management in wireless networks. Based upon receipt of an indication of the link margin of a receiving wireless device, a transmitting wireless device may adjust its transmit power commensurate with the link margin. The indication of the link margin may be transmitted from the receiving wireless device to the transmitting wireless device periodically. Alternatively, the receiving wireless station may provide the indication of the link margin in response to information received from the transmitting wireless device. In this instance, the indication of the link margin may be included in a piggyback acknowledgement (ACK) frame conventionally used to acknowledge receipt of the information transmitted by the transmitting wireless station.

Claims

1. In a wireless network comprising at least a first wireless device and a second wireless device, a method comprising the steps of:

determining a link margin of the second wireless device based at least in part on one or more signals received from the first wireless device; and

transmitting an indication of the link margin for reception by the first wireless device.

2. The method as in claim 1, wherein the indication is transmitted as part of an acknowledgement (ACK) frame acknowledging receipt of information from the first wireless device.

3. The method as in claim 1, wherein the indication is transmitted as part of a Data frame which is transmitted for receipt by the first device.

4. The method as in claim 1, wherein the indication is received as part of a Data frame which is transmitted for receipt by the first device.

5. In a wireless network comprising at least a first wireless device and a second wireless device, a method comprising the steps of:

receiving, at the first wireless device, an indication of a link margin of the second wireless device; and

adjusting a transmit power of the first wireless device based at least in part on the indication of the link margin of the second wireless device.

6. The method as in claim 5, wherein the indication of the link margin is received as part of an acknowledgement (ACK) frame acknowledging receipt of information from the first wireless device.

7. In a wireless network comprising at least a first wireless device and a second wireless device, a method comprising:

receiving, at the second wireless device, information from the first wireless device; and

transmitting link margin information of the second wireless device for reception by the first wireless device in response to the receipt of the information from the first wireless device.

8. The method of claim 7, further comprising the step of:

adjusting a transmit power of the first wireless device based at least in part on the link margin information of the second wireless device.

9. The method as in claim 7, further comprising the step of:

transmitting, at the adjusted transmit power, information from the first wireless device for reception by the second wireless device.

10. The method as in claim 7, further comprising the step of:

determining a link margin of the second wireless device.

11. The method as in claim 10, wherein the link margin is determined from a signal representative of the information received from the first wireless device.

12. The method as in claim 10, wherein the link margin includes a moving average of link margins determined for a plurality of signals received from the first wireless device.

13. The method as in claim 10, wherein the link margin information includes an estimate of the link margin at other rates.

14. The method as in claim 10, wherein the link margin information includes an estimate of the optimal rate to use for this connection.

15. The method as in claim 7, wherein the link margin information is transmitted as part of an acknowledgement acknowledging receipt of the information from the first wireless device.

16. The method as in claim 7, wherein the link margin information is transmitted as part of a data frame which is transmitted for reception by first wireless device.

17. The method as in claim 16, wherein the presence of link margin information is indicated by the use of an LLC level encapsulation.

18. The method as in claim 16, wherein the presence of link margin information is indicated by a bit in the MAC header.

19. The method as in claim 16, wherein the presence of link margin information is indicated by a specific type/subtype combination inside the MAC header.

20. The method as in claim 10, wherein the acknowledgment includes an ACK frame.

21. The method as in claim 11, wherein at least a portion of the link margin information is included in a Frame Control field of the ACK frame.

22. In a wireless network comprising at least a first wireless device and a second wireless device, a method comprising the steps of:

transmitting, from the first wireless device, information for reception by the second wireless device;

receiving an acknowledgment of a receipt of the information from the second wireless device, the acknowledgement including link margin information of the second wireless device.

23. The method as in claim 22, further comprising the step of:

adjusting a transmit power of the first wireless device based at least in part on the link margin information.

24. The method as in claim 22, further comprising the step of:

transmitting, at the adjusted transmit power, information from the first wireless device for reception by the second wireless device.

25. The method as in claim 22, wherein the acknowledgement includes an ACK frame.

26. The method as in claim 25, wherein at least a portion of the link margin information is included in a Quality of Service (QoS) field of the ACK frame.

27. In a wireless network comprising at least a first wireless device and a second wireless device, a method comprising:

receiving, at the second wireless device, information transmitted by the first wireless device at a first transmit power;

transmitting an acknowledgement (ACK) frame from the second wireless device for reception by the first wireless device, the ACK frame acknowledging receipt of the information at the second wireless device and including link margin information of the second wireless device; and

receiving, at the second wireless device, information transmitted by the first wireless device at a second transmit power;

wherein a difference between the first transmit power and the second transmit power is based on the link margin information.

28. A wireless device comprising:

a transceiver;

a link margin measurement module for measuring a link margin of the wireless device based at least in part on signals received by the transceiver;

means for transmitting, via the transceiver, link margin information for reception by a second wireless device in response to a receipt of information transmitted by the second wireless device.

29. The wireless device as in claim 28, wherein the link margin is determined at least in part from a signal representative of the information received from the second wireless device.

30. The wireless device as in claim 28, wherein the link margin includes a moving average of link margins determined for a plurality of signals received from the second wireless device.

31. The wireless device as in claim 28, wherein the link margin information is transmitted as part of an acknowledgement acknowledging receipt of the information from the second wireless device.

32. The wireless device as in claim 31, wherein the acknowledgment includes an ACK frame.

33. The wireless device as in claim 32, wherein at least a portion of the link margin information is included in a Quality of Service (QoS) field of the ACK frame.

34. A wireless device comprising:

a transceiver;

means for receiving an acknowledgment of a receipt of information from a second wireless device, the acknowledgement including link margin information of the second wireless device; and

a transmit power adjustment module for adjusting a transmit power of the transceiver based at least in part on the link margin information.

35. The wireless device as in claim 34, wherein the acknowledgement includes an ACK frame.

36. The wireless device as in claim 35, wherein at least a portion of the link margin information is included in a Quality of Service (QoS) field of the ACK frame.