Direct link relay in a wireless network

• US 20090073913A9
• Filed: 06/30/2004
• Published: 03/19/2009
• 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 8,050,360 B2
• Time in Patent Office: Days
• US Class Current: 370/315
• CPC Class Codes: H04W 40/10 based on available power or energy
• CPC Class Codes: H04W 52/0258 controlling an operation mode according to history or models of usage information, e.g. activity schedule or time of day
• CPC Class Codes: H04W 52/04 TPC
• 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
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Disclosed herein are exemplary techniques for power conservation in a wireless network. A wireless device identifies another wireless device suitable to act as a relay node. Uplink information is transmitted to the other wireless device, which is in turn relayed to an access point for transmission to its destination. Downlink information may be transmitted directly from the access point to the wireless device. The use of a relay node may reduce transmit power consumption as the relay node may be closer to, or support a higher transmit rate, than the access point with which the wireless device is associated.

Claims

1. In a wireless network comprising an access point communicating with at least a first wireless device and a second wireless device, a method comprising:

receiving, at the first wireless device, uplink information from the second wireless device via a direct wireless link between the first and second wireless device, wherein a destination of the uplink information includes a networked device communicable with the access point; and

relaying at least a portion of the uplink information from the first wireless device to the access point for transmission to the networked device.

2. The method as in claim 1, further comprising:

receiving, at the second wireless device, downlink information directly from the access point, the downlink information having the second wireless device as a destination.

3. The method as in claim 1, wherein relaying at least a portion of the uplink information comprises:

identifying, at the first wireless device, the destination of the uplink information; and

transmitting at least a portion of the uplink information for reception by the access point when the first wireless device is not the destination of the uplink information.

4. The method as in claim 1, wherein the uplink information received from the second wireless device includes at least one frame having a header with a network address of the second wireless device as a source address, a network address of the first wireless device as an intermediate recipient address;

and a network address of the networked device as a destination address; and

wherein relaying at least a portion of the uplink information to the access point includes modifying the header of the at least one frame to have a network address of the access point as the intermediate recipient address and relaying the at least one frame to the access point.

5. The method as in claim 1, further comprising:

determining that a first transmit power necessary to transmit the uplink information from the second wireless device to the first wireless device via the direct wireless link is less than a second transmit power necessary to transmit the uplink information from the second wireless device directly to the access point.

6. In a wireless network comprising an access point communicating with to a plurality of wireless devices, a method comprising:

identifying a first wireless device capable of relaying at least a portion of uplink information from a second wireless device to the access point, the uplink information having as a destination a networked device communicable with the access point;

establishing a direct wireless link between the first wireless device and the second wireless device; and

transmitting at least a portion of the uplink information from the second wireless device to the first wireless device via the direct wireless link for relay to the access point.

7. The method as in claim 6, further comprising relaying at least a portion of the uplink information to the access point.

8. The method as in claim 6, wherein the uplink information from the second wireless device includes at least one frame having a header with a network address of the second wireless device as a source address, a network address of the first wireless device as an intermediate recipient address, and a network address of the networked device as a destination address;

and

wherein relaying at least a portion of the uplink information to the access point includes modifying the header to have a network address of the access point as the intermediate recipient address.

9. The method as in claim 6, further comprising:

determining that a first transmit power necessary to transmit the uplink information from the second wireless device directly to the access point is greater than a second transmit power necessary to transmit the uplink information from the second wireless device to a selected wireless device of the plurality of wireless devices.

10. The method as in claim 9, further comprising:

receiving, at the second wireless device, a relay node discovery frame from one or more of the plurality of wireless devices, the relay node discovery frame identifying the corresponding wireless device as available to relay frames to the access point and having an associated transmit power used to transmit the relay node discovery frame;

determining a path loss for the corresponding wireless device from the received relay node discovery frame, wherein the path loss is based at least in part on a difference between the transmit power associated with the relay node discovery frame and a received power of the relay node discovery frame; and

selecting a wireless device as the first wireless device based at least in part on a comparison of the path losses.

11. The method as in claim 10, wherein the wireless device having the lowest path loss is selected.

12. The method as in claim 6, wherein a first transmit power necessary to transmit the uplink information from the second wireless device to the first wireless device via the direct wireless link is less than a second transmit power necessary to transmit the uplink information from the second wireless device directly to the access point.

13. A wireless device comprising:

a transceiver adapted to receive uplink information from another wireless device via a direct wireless link with the other wireless device, wherein the uplink information has as a destination a networked device communicable with an access point; and

the transceiver further adapted to transmit at least a portion of the uplink information to the access point for transmission to the networked device.

14. The wireless device as in claim 13, wherein means for relaying at least a portion of the uplink information comprise:

means for identifying the destination of the uplink information; and

wherein the transceiver is adapted to transmit at least a portion of the uplink information for reception by the access point when the wireless device is not the destination of the uplink information.

15. The wireless device as in claim 13, wherein the uplink information received from the other wireless device includes at least one frame having a header with a network address of the other wireless device as a source address, a network address of the wireless device as an intermediate recipient address;

and a network address of the networked device as a destination address; and

wherein the means for relaying at least a portion of the uplink information to the access point includes means for modifying the header of the at least one frame to have a network address of the access point as the intermediate address.

16. The wireless device as in claim 13, wherein a first transmit power necessary to transmit the uplink information from the other wireless device to the wireless device via the direct wireless link is less than a second transmit power necessary to transmit the uplink information from the other wireless device directly to the access point.

17. The wireless device as in claim 13, further comprising at least one processor operably connected to the transceiver;

and wherein;

the transceiver comprises executable instructions adapted to manipulate the at least one processor to receive, via the transceiver, the uplink information from the other wireless device via the direct wireless link with the other wireless device; and

wherein the transceiver is further adapted for relaying at least a portion of the uplink information to the access point comprise executable instructions adapted to manipulate at least one processor to relay, via the transceiver, at least a portion of the uplink information to the access point for transmission to the networked device.

18. The wireless device as in claim 13, further comprising means for transmitting a relay node discovery frame for reception by one or more other wireless devices, the relay node discovery frame representing that the wireless device is available to relay frames and including an indication of a transmit power used to transit the relay node discovery frame.

19. A wireless device comprising:

a transceiver;

circuit means for identifying another wireless device capable of relaying at least a portion of uplink information from the wireless device to an access point, the uplink information having a networked device operably connected to the access point as a destination;

communication means for establishing a direct wireless link with the other wireless device; and

transmitter means for transmitting, via the transceiver, the uplink information to the other wireless device via the direct wireless link for relay to the access point.

20. The wireless device as in claim 19, wherein the means for identifying the other wireless device include:

Receiver means for estimating a first transmit power necessary to transmit the uplink information from the wireless device directly to the access point;

first circuit means for estimating a second transmit power necessary to transmit the uplink information from the wireless device to a selected wireless device of one or more other wireless devices; and

second circuit means for identifying the selected wireless device as capable of relaying at least a portion of the uplink information when the second transmit power is less than the first transmit power.

21. The wireless device as in claim 20, further comprising:

receiver means for receiving a relay node discovery frame from one or more other wireless devices, the relay node discovery frame identifying the corresponding wireless device as available to relay frames to the access point and including an indication of a transmit power used to transmit the relay node discovery frame;

third circuit means for determining a path loss for at least one of the one or more received relay node discovery frames, wherein the path loss is based at least in part on a difference between the transmit power indicated by the relay node discovery frame and a received power of the relay node discovery frame; and

fourth circuit means for selecting a wireless device from the one or more other wireless devices based at least in part on a comparison of the path losses.

22. The method as in claim 21, wherein the other wireless device having the lowest path loss is selected.

23. The method as in claim 19, wherein a first transmit power necessary to transmit the uplink information from the wireless device to the other wireless device via the direct wireless link is less than a second transmit power necessary to transmit the uplink information from the wireless device directly to the access point.

24. The wireless device as in claim 19, further comprising at least one processor operably connected to the transceiver, and wherein:

the means for receiving the uplink information comprise executable instructions adapted to manipulate the at least one processor to receive, via the transceiver, the uplink information from the other wireless device via the direct wireless link with the other wireless device; and

the means for relaying at least a portion of uplink information comprise executable instructions adapted to manipulate the at least one processor to relay, via the transceiver, at least a portion of the uplink information to the access point for transmission to the networked device.

25. A wireless system comprising:

a first wireless device; and

a second wireless device in communication with to an access point;

wherein the first wireless device is adapted to;

identify the second wireless device as capable of relaying at least a portion of uplink information to the access point, the uplink information having a networked device operably connected to the access point as a destination; and

transmit the uplink information to the second wireless device via a direct wireless link between the first and second wireless devices; and

wherein the second wireless device is adapted to relay at least a portion of the uplink information to the access point for transmission to the networked device.

26. The wireless system as in claim 25, wherein the first wireless device is further adapted to receive downlink information directly from the access point, the downlink information having the first wireless device as a destination.

27. The wireless system as in claim 25, wherein the second wireless device is adapted to relay at least a portion of the uplink information by:

identifying, at the second wireless device, the destination of the uplink information; and

transmitting at least a portion of the uplink information for reception by the access point when the second wireless device is not the destination of the uplink information.

28. The wireless system as in claim 25, wherein the uplink information received from the first wireless device includes at least one frame having a header with a network address of the first wireless device as a source address, a network address of the second wireless device as an intermediary address;

and a network address of the networked device as a destination address; and

wherein relaying at least a portion of the uplink information to the access point includes modifying the header to have a network address of the access point as the intermediary address.

29. The wireless system as in claim 25, wherein a first transmit power necessary to transmit the uplink information from the first wireless device to the second wireless device via the direct wireless link is less than a second transmit power necessary to transmit the uplink information from the first wireless device directly to the access point.

30. The wireless system as in claim 25, wherein first wireless device is adapted to identify the second wireless device by:

estimating a first transmit power necessary to transmit the uplink information from the first wireless device directly to the access point;

estimating a second transmit power necessary to transmit the uplink information from the first wireless device to a selected wireless device of the plurality of wireless devices; and

identifying the selected wireless device as capable of relaying at least a portion of the uplink information when the second transmit power is less than the first transmit power.

31. The wireless system as in claim 25, wherein the second wireless device is further adapted to transmit a relay node discovery frame for reception by the first wireless device, the relay node discovery frame identifying the second wireless device as available to relay frames to the access point and including an indication of a transmit power used to transmit the relay node discovery frame;

and

wherein the first wireless device is further adapted to;

determine a path loss for the relay node discovery frame, wherein the path loss is based at least in part on a difference between the transmit power indicated by the relay node discovery frame and a received power of the relay node discovery frame; and

select the second wireless device based at least in part on a comparison of the path loss to path losses of one or more other wireless devices.