Direct link relay in a wireless network

• US 8,050,360 B2
• Filed: 06/30/2004
• Issued: 11/01/2011
• Est. Priority Date: 06/12/2002
• Status: Active Grant

• Current Assignee: Intellectual Ventures I LLC (Intellectual Ventures LLC)
• Original Assignee: Intellectual Ventures I LLC (Intellectual Ventures LLC)
• Inventors: Wentink, Menzo
• Primary Examiner(s): Liu; Shuwang
• Assistant Examiner(s): TAYONG, HELENE E
• Application Number:
  US10/880,367
• Publication Number:
  US 20050094588A1
• Time in Patent Office: 2,680 Days
• Field of Search: 375/315, 375/309, 455/73, 455/522, 370/315, 370/350, 370/338, 370/401, 370/455, 370/473
• US Class Current: 375/315
• 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, a first wireless device, and a second wireless device, a method comprising:

receiving, at the first wireless device, an uplink data frame from the second wireless device via a direct wireless link between the first and second wireless devices, the uplink data frame comprised of a data payload portion and a header portion, the header portion including routing information for routing the data payload portion to an ultimate destination device via the access point, the ultimate destination device being different than the first wireless device, the second wireless device, and the access point, and the routing information including at least a source address field, an intermediate address field containing an address of the first wireless device, and a destination address field containing an address of the ultimate destination device; and

the first wireless device relaying at least the data payload portion of the uplink data frame from the first wireless device to the access point;

wherein relaying at least the data payload portion of the uplink data frame comprises the first wireless device;

modifying the address portion contained in the intermediate address field of the header portion to match an address of the access point; and

transmitting the modified header portion and the data payload in a modified uplink data frame to the access point.

2. The method as in claim 1, wherein the source address field of the uplink data frame received from the second wireless device indicates a network address of the second wireless device as a source of the data payload portion.

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

determining, prior to transmitting the uplink data frame from the second wireless device to the first wireless device, that a first transmit power necessary to transmit the uplink data frame 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 data frame from the second wireless device directly to the access point.

4. The method as in claim 1, further comprising, prior to receiving an uplink data frame from the second wireless device, transmitting from the first wireless device to the second wireless device a relay node discovery frame identifying the first wireless device as available to relay frames to the access point and including information identifying an associated transmit power level used to transmit the relay node discovery frame.

5. In a wireless network comprising an access point and first and second wireless devices, a method comprising:

the second wireless device identifying the first wireless device to relay an uplink data frame from the second wireless device to the access point, the uplink data frame comprised of a data payload portion and a header portion, the header portion including routing information for routing the data payload portion to an ultimate destination device via the access point, the ultimate destination device being different than the first wireless device, the second wireless device, and the access point, and the routing information including at least a source address field, an intermediate address field containing an address of the first wireless device, and a destination address field containing an address of the ultimate destination device;

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

the second wireless device transmitting the uplink data device to the first wireless device via the direct wireless link for relay to the access point;

wherein the source address field includes a source address portion indicating a network address of the second wireless device as a source of the data payload portion and the destination address field indicates a network address of the ultimate destination device as an ultimate destination of the data payload portion; and

wherein relaying at least the data payload portion of the uplink data frame to the access point includes modifying the address portion contained in the intermediate address field of the header portion to match an address of the access point and transmitting the data payload and modified header in a modified uplink data frame to the access point.

6. The method as in claim 5, wherein a first transmit power necessary to transmit the uplink data frame 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 data frame from the second wireless device directly to the access point.

7. A wireless device comprising:

a transceiver, joined in a wireless network comprising at least another wireless device and an access point, and configured to receive an uplink data frame from the another wireless device via a direct wireless link with the another wireless device, wherein the uplink data frame is comprised of a data payload portion and a header portion, the header portion including routing information for routing the data payload portion from the another wireless device to an ultimate destination device, the destination device being different than the wireless device, the another wireless device, and the access point, and the routing information including at least a source address field, an intermediate address field containing an address of the first wireless device, and a destination address field containing an address of the ultimate destination device;

the transceiver further configured to transmit at least the data payload portion of the uplink data frame to the access point for transmission to the destination device; and

means for modifying the address contained in the intermediate address field of the uplink data frame to match an address of the access point, and transmitting the modified header portion and the data payload portion to the access point in a modified uplink data frame.

8. The wireless device as in claim 7, wherein the source address field indicates a network address of the another wireless device as a source of the data payload portion.

9. The wireless device as in claim 7, wherein a first transmit power necessary to transmit the uplink data frame from the another wireless device to the wireless device via the direct wireless link is less than a second transmit power necessary to transmit the uplink data frame from the another wireless device directly to the access point.

10. The wireless device as in claim 7, further comprising at least one processor operably connected to the transceiver;

wherein the processor is configured to receive, via the transceiver, the uplink data frame from the another wireless device via the direct wireless link with the another wireless device; and

wherein the processor is further configured to receive, via the transceiver, at least the data payload portion of the uplink data frame to the access point for transmission to the ultimate destination device.

11. The wireless device as in claim 7, wherein the transceiver is further configured to transmit to the second wireless device, a relay node discovery frame identifying the transceiver as available to relay frames to the access point and including information identifying an associated transmit power level used to transmit the relay node discovery frame.

12. In a wireless network comprising an access point and a plurality of wireless devices, a method comprising:

identifying a first wireless device to relay an uplink data frame from a second wireless device to the access point, the uplink data frame comprised of a data payload portion and a header portion, the header portion including routing information for routing the data payload portion to an ultimate destination device via the access point, the ultimate destination device being different than the first wireless device, the second wireless device, and the access point, and the routing information including at least a source address field, an intermediate address field containing an address of the first wireless device, and a destination address field containing an address of the ultimate destination device;

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

transmitting the uplink data frame from the second wireless device to the first wireless device via the direct wireless link for relay to the access point;

further comprising, prior to transmitting the uplink data frame, determining that a first transmit power necessary to transmit the uplink data frame from the second wireless device directly to the access point is greater than a second transmit power necessary to transmit the uplink data frame from the second wireless device to the first wireless device.

13. The method as in claim 12, further comprising:

receiving, at the second wireless device, a relay node discovery frame, the relay node discovery frame identifying a sender of the frame as available to relay frames to the access point and including information identifying an associated transmit power level used to transmit the relay node discovery frame;

determining a path loss to the sender from the received relay node discovery frame, wherein the path loss is based at least in part on a difference between the transmit power identified in the relay node discovery frame and a measured power during reception of the relay node discovery frame; and

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

14. The method as in claim 13, wherein the sender is determined to have the lowest path loss.

15. A wireless device comprising:

a transceiver;

means for identifying another wireless device to relay at least a data payload portion of an uplink data frame from the wireless device to an access point for delivery to an ultimate destination device, the uplink data frame comprised of a data payload portion and a header portion, the header portion including routing information for routing the data payload portion to the ultimate destination device, the ultimate destination device being different than the wireless device, the another wireless device, and the access point, and the routing information including at least a source address field, an intermediate address field containing an address of the first wireless device, and a destination address field containing an address of the ultimate destination device;

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

transmitter means for transmitting, via the transceiver, the uplink data frame to the another wireless device via the direct wireless link for relay to the access point; and

power determining means for determining that a first transmit power necessary to transmit the uplink data frame from the wireless device to the another 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.

16. The wireless device as in claim 15, wherein the means for identifying the another wireless device identifies the another wireless device to relay at least the data payload portion of the uplink data packet to the access point responsive to the power determining means determining that the second transmit power is less than the first transmit power.

17. The wireless device as in claim 15, further comprising:

means for receiving a relay node discovery frame from the another wireless device, the relay node discovery frame identifying the another wireless device as available to relay frames to the access point and including information identifying a transmit power level used to transmit the relay node discovery frame;

means for determining a path loss for the received relay node discovery frame, wherein the path loss is based at least in part on a difference between the transmit power identified by the relay node discovery frame and a measured power during reception of the relay node discovery frame; and

means for selecting the another wireless device based at least in part on a comparison of path losses, the another wireless device having the lowest path loss.

18. A wireless system comprising:

a first wireless device; and

a second wireless device configured to communicate with an access point;

wherein the first wireless device is configured to;

identify the second wireless device to relay at least a data payload portion of an uplink data frame to the access point for delivery to an ultimate destination device, the uplink data frame is comprised of a data payload portion and a header portion, the header portion including routing information for routing the data payload portion to the ultimate destination device, via the access point, the destination device being different than the first wireless device, the second wireless device, and the access point, and the routing information including at least a source address field, an intermediate address field containing an address of the first wireless device, and a destination address field containing an address of the ultimate destination device;

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

wherein the second wireless device is configured to;

transmit at least the data payload portion of the uplink data frame to the access point for transmission to the ultimate destination device; and

wherein the second wireless device is configured to relay at least the data payload portion of the uplink data frame by;

modifying the address contained in the intermediate address field to match an address of the access point and transmitting at least the modified header portion and the data payload portion in a modified uplink data frame to the access point.

19. The wireless system as in claim 18, wherein the first wireless device is further configured to receive a downlink data frame directly from the access point, the downlink data frame including a header portion having an ultimate destination address indicating the first wireless device as an ultimate destination.

20. The wireless system as in claim 18, wherein the source address field indicates a network address of the first wireless device as a source of the data payload portion.

21. The wireless system as in claim 18, wherein the second wireless device is further configured to transmit a relay node discovery frame to 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 level used to transmit the relay node discovery frame;

and

wherein the first wireless device is further configured 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 in the relay node discovery frame and a measured power during reception of the relay node discovery frame; and

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

22. The wireless system as in claim 18, wherein the first wireless device is further configured to, prior to transmitting the uplink data frame to the second wireless device, determine that a first transmit power necessary to transmit the uplink data frame 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 data frame from the first wireless device directly to the access point.

23. The wireless system as in claim 22, wherein the first wireless device is configured to identify the second wireless device to relay at least the data payload portion of the uplink data frame responsive to the determination that the first transmit power is less than the second transmit power.

24. A method comprising:

receiving, at a first wireless device, an uplink data frame from a second wireless device via a direct wireless link, wherein the uplink data frame includes a data payload portion and a header portion, wherein the header portion includes routing information that comprises an intermediate address field including an address of the first wireless device, wherein the routing information further comprises a source address field and a destination address field including an address of an ultimate destination device of the data payload portion, and wherein the ultimate destination device is not the first wireless device;

modifying the address in the intermediate address field of the header portion to match an address of an access point associated with the first and second wireless devices; and

transmitting the modified header portion and the data payload in a modified uplink data frame to the access point.

25. The method of claim 24, wherein the source address field of the uplink data frame received from the second wireless device indicates a network address of the second wireless device as a source of the data payload portion.

26. The method of claim 24, further comprising determining, at the first wireless device, if the first wireless device is the ultimate destination device of the data payload portion by comparing the destination address field to an address of the first wireless device.

27. The method of claim 24, wherein a first transmit power necessary to transmit the uplink data frame 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 data frame from the second wireless device directly to the access point.

28. The method of claim 24, further comprising, prior to said receiving an uplink data frame from the second wireless device, transmitting from the first wireless device to the second wireless device a relay node discovery frame identifying the first wireless device as available to relay frames to the access point and including information identifying an associated transmit power level used to transmit the relay node discovery frame.

29. An apparatus comprising:

a transceiver configured to receive an uplink data frame from a wireless device via a direct wireless link, wherein the uplink data frame includes a data payload portion and a header portion, wherein the header portion includes routing information that comprises an intermediate address field including an address of the first wireless device, wherein the routing information further comprises a source address field and a destination address field including an address of an ultimate destination device of the data payload portion, and wherein the ultimate destination device is not the first wireless device; and

a processor configured to modify the address in the intermediate address field of the header portion to match an address of an access point associated with the first and second wireless devices;

wherein the transceiver is further configured to transmit the modified header portion and the data payload in a modified uplink data frame to the access point.

30. The apparatus of claim 29, wherein the source address field of the uplink data frame received from the second wireless device indicates a network address of the second wireless device as a source of the data payload portion.

31. The apparatus of claim 29, wherein the processor is further configured to determine if the apparatus is the ultimate destination device of the data payload portion by comparing the destination address field to an address of the apparatus.

32. The apparatus of claim 29, wherein a first transmit power necessary to transmit the uplink data frame from the wireless device to the apparatus via the direct wireless link is less than a second transmit power necessary to transmit the uplink data frame from the wireless device directly to the access point.

33. The apparatus of claim 29, wherein the transceiver is configured to, prior to said receiving an uplink data frame from the wireless device, transmit to the wireless device a relay node discovery frame identifying the apparatus as available to relay frames to the access point and including information identifying an associated transmit power level used to transmit the relay node discovery frame.

34. An article of manufacture including a non-transitory computer-readable medium having instructions stored thereon, the instructions comprising:

instructions to receive, at a first wireless device, an uplink data frame from a second wireless device via a direct wireless link, wherein the uplink data frame includes a data payload portion and a header portion, wherein the header portion includes routing information that comprises an intermediate address field including an address of the first wireless device, wherein the routing information further comprises a source address field and a destination address field including an address of an ultimate destination device of the data payload portion, and wherein the ultimate destination device is not the first wireless device;

instructions to modify the address in the intermediate address field of the header portion to match an address of an access point associated with the first and second wireless devices; and

instructions to transmit the modified header portion and the data payload in a modified uplink data frame to the access point.

35. The article of manufacture of claim 34, wherein the source address field of the uplink data frame received from the second wireless device indicates a network address of the second wireless device as a source of the data payload portion.

36. The article of manufacture of claim 34, further comprising instructions to determine if the first wireless device is the ultimate destination device of the data payload portion by comparing the destination address field to an address of the first wireless device.

37. The article of manufacture of claim 34, wherein a first transmit power necessary to transmit the uplink data frame 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 data frame from the second wireless device directly to the access point.