Systems and methods for determining location of devices within a wireless network

• US 8,175,613 B2
• Filed: 04/27/2007
• Issued: 05/08/2012
• Est. Priority Date: 08/04/2006
• Status: Active Grant

• Current Assignee: CommWorks Solutions, LLC (IP Investments Group LLC)
• Original Assignee: Misonimo Chi Acquisitions LLC (Intellectual Ventures LLC)
• Inventors: Patil, Abhishek, Wang, Xudong, Gui, Chao, Wang, Weilin, Nova, Michael
• Primary Examiner(s): Hu, Jinsong
• Assistant Examiner(s): Chang, Jean
• Application Number:
  US11/741,630
• Publication Number:
  US 20080032705A1
• Time in Patent Office: 1,838 Days
• Field of Search: 455/456.1
• US Class Current: 455/456.1
• CPC Class Codes: H04L 65/104 in the network
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 67/104 Peer-to-peer [P2P] networks
• CPC Class Codes: H04W 4/18 Information format or content conversion, e.g. adaptation by the network of the transmitted or received information for the purpose of wireless delivery to users or terminals
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

Systems and methods for determining a location of a device with a wireless network. Characteristics of signals received from the device at a plurality of nodes are measured. Based upon the measurements, estimates of the range from the device to the nodes are made. Then, based upon the estimated ranges, and knowing the location of the nodes, a location of the device is determined.

Claims

1. A method for estimating a location of a first wireless device within a wireless network, the method comprising:

a second device receiving signal characteristic information in a transmission from each of one or more third wireless devices, each signal characteristic information received from each of the one or more third wireless devices including (i) measured signal characteristics of a first signal transmitted by the first wireless device at a first power level during a first variable signal level period of a first media access control (MAC) superframe and received at the respective third wireless device and (ii) measured signal characteristics of a second signal transmitted by the first wireless device at a second power level during a second variable signal level period of a second MAC superframe and received at the respective third wireless device, the second power level being different than the first power level;

the second device estimating a range from the first wireless device to each of the respective one or more third wireless devices based upon the signal characteristic information received from the one or more third wireless devices; and

the second device estimating a location of the first wireless device based upon the estimated ranges.

2. The method of claim 1, wherein the wireless network is a wireless mesh network.

3. The method of claim 1, wherein the first and second signals conform to IEEE802.11 standard.

4. The method of claim 1, wherein the first and second signals are ultra-wideband signals.

5. The method of claim 1, wherein the measured characteristic is one selected from the group consisting of strength of the received signal, time of arrival, and time difference of arrival.

6. The method of claim 1, wherein the estimating a location comprises one selected from the group consisting of triangulation, trilateration, weighting, and estimating the centroid of a region.

13. The method of claim 1, wherein the second device comprises a second wireless device, the method further comprising:

the second wireless device receiving the first signal transmitted by the first wireless device at the first power level;

the second wireless device measuring a characteristic of the first signal;

the second wireless device receiving the second signal transmitted by the first wireless device at the second power level; and

the second wireless device measuring a characteristic of the second signal;

the second wireless device estimating a range from the first wireless device to the second wireless device based upon the measured characteristics; and

the second wireless device estimating a location of the first wireless device based upon the estimated ranges.

14. The method of claim 1, wherein the second device comprises a second wireless device, the method further comprising the second wireless device transmitting information to the first wireless device based upon the estimated location.

21. The method of claim 1, wherein the first MAC superframe and the second MAC superframe are the same MAC superframe.

22. The method of claim 1, wherein the first MAC superframe and the second MAC superframe are different MAC superframes.

23. The method of claim 1, wherein the MAC superframe further comprises:

a beacon period;

a contention access period; and

a contention free period.

24. The method of claim 1, further comprising the first wireless device transmitting a third signal at a third power level during a third variable signal level period of a third MAC superframe, the third power level being different than the first and second power levels.

25. The method of claim 1, further comprising, responsive to transmitting the first and second signals, the first wireless device receiving information based upon an estimated location of the first wireless device.

26. The method of claim 1, wherein the first and second signals are ultra-wideband signals.

39. The method of claim 1, further comprising

the second device receiving signal characteristic information in transmissions from each of a plurality of third wireless devices;

the second device estimating a range from the first wireless device to each of the respective plurality of third wireless devices based upon the signal characteristic information received from the plurality of third wireless devices; and

the second device estimating a location of the first wireless device based upon the estimated ranges.

7. A first device in a wireless network for estimating a location of a second wireless device, comprising:

a measurement module configured to;

receive signal characteristic information in a transmission from each of one or more third wireless devices, each signal characteristic information received from each of the one or more third wireless devices including (i) measured signal characteristics of a first signal transmitted by the second wireless device at a first power level during a first variable signal level period of a first media access control (MAC) superframe and received at the respective third wireless device and (ii) measured signal characteristics of a second signal transmitted by the second wireless device at a second power level during a second variable signal level period of a second MAC superframe and received at the respective third wireless device, the second power level being different than the first power level;

estimate a range from the second wireless device to each of the third wireless devices based upon the signal characteristic information received from the one or more third wireless devices; and

estimate a location of the second wireless device based upon the estimated ranges.

8. The first device of claim 7, wherein the wireless network is a wireless mesh network.

9. The first device of claim 7, wherein the first and second signals conform with the IEEE802.11 standard.

10. The first device of claim 7, wherein the first and second signals comprise ultra-wideband signals.

11. The first device of claim 7, wherein the measured signal characteristic is one selected from the group consisting of strength of a received signal, time of arrival, and time difference of arrival.

12. The first device of claim 7, wherein the estimating a location comprises one selected from the group consisting of triangulation, trilateration, weighting, and estimating the centroid of a region.

15. The first device of claim 7, wherein the first device comprises a first wireless device, the first device further comprising:

a topology module configured to align a beacon signal of the first wireless device with the wireless network;

a signaling module configured to send and receive data communications over the wireless communication network with the one or more third wireless devices.

40. The first device of claim 7, wherein the measurement module is further configured to:

receive signal characteristic information in transmissions from each of a plurality of third wireless devices;

estimate a range from the second wireless device to each of the respective plurality of third wireless devices based upon the signal characteristic information received from the plurality of third wireless devices; and

estimate a location of the first wireless device based upon the estimated ranges.

16. An article of manufacture including a non-transitory computer readable medium having instructions stored thereon that, in response to execution by a computing device, cause the computing device to perform operations for estimating a location of a first wireless device within a wireless network, the operations comprising:

receiving signal characteristic information transmitted by each of one or more second wireless devices, each signal characteristic information received from each of the one or more second wireless devices including (i) measured signal characteristics of a first signal transmitted by the first wireless device at a first power level during a first variable signal level period of a first media access control (MAC) superframe and received at the respective second wireless device and (ii) measured signal characteristics of a second signal transmitted by the first wireless device at a second power level during a second variable signal level period of a second MAC superframe and received at the respective second wireless device, the second power level being different than the first power level;

estimating a range from the first wireless device to each of them respective one or more second wireless devices based upon the information received from the one or more second wireless devices; and

estimating a location of the first wireless device based upon the estimated ranges.

17. The article of manufacture of claim 16, wherein the first and second signals are ultra-wideband (UWB) signals.

18. The article of manufacture of claim 16, wherein the measured characteristic is one selected from the group consisting of strength of the received signal, time of arrival, and time difference of arrival.

19. The article of manufacture of claim 16, wherein the estimating a location comprises one selected from the group consisting of triangulation, trilateration, weighting, and estimating the centroid of a region.

20. The article of manufacture of claim 16, wherein the operations further comprise transmitting information based upon the estimated location to the first wireless device.

41. The article of manufacture of claim 16, wherein the operations further comprise:

receiving signal characteristic information in transmissions from each of a plurality of third wireless devices;

estimating a range from the first wireless device to each of the respective plurality of third wireless devices based upon the signal characteristic information received from the plurality of third wireless devices; and

estimating a location of the first wireless device based upon the estimated ranges.

27. A method for estimating a location of a first wireless device within a wireless network, the method comprising:

a second wireless device measuring signal characteristics of a first signal transmitted by the first wireless device at a first power level during a first variable signal level period of a first media access control (MAC) superframe;

the second wireless device measuring signal characteristics of a second signal transmitted by the first wireless device at a second power level during a second variable signal level period of a second MAC superframe, the second power level being different than the first power level;

the second wireless device transmitting to a location server at least one of (i) the measured signal characteristics or (ii) a range estimated from the second wireless device to the first wireless device.

28. The method of claim 27, wherein the second wireless device transmitting to a location server at least one of (i) the measured signal characteristics or (ii) a range estimated from the second wireless device to the first wireless device comprises the second wireless device transmitting to the location server the measured signal characteristics.

29. The method of claim 27, wherein the second wireless device transmitting to a location server at least one of (i) the measured signal characteristics or (ii) a range estimated from the second wireless device to the first wireless device comprises the second wireless device transmitting to the location server the range estimated from the second wireless device to the first wireless device.

30. The method of claim 27, wherein the first and second signals transmitted by the first wireless device are transmitted during a variable signal level period of one or more MAC superframes.

31. A second wireless device in a wireless network configured to:

measure signal characteristics of a first signal transmitted by a first wireless device at a first power level during a first variable signal level period of a first media access control (MAC) superframe;

measure signal characteristics of a second signal transmitted by the first wireless device at a second power level during a second variable signal level period of a first media access control MAC superframe;

measure signal characteristics of a second signal transmitted by the first wireless device at a second power level during a second variable signal level period of a second MAC superframe, the second power level being different than the first power level;

transmit to a location server at least one of (i) the measured signal characteristics or (ii) a range estimated from the first wireless device to the second wireless device.

32. The second wireless device of claim 31, further configured to transmit to the location server the measured signal characteristics.

33. The second wireless device of claim 31, further configured to transmit to the location server the range estimated from the first wireless device to the second wireless device.

34. The second wireless device of claim 31, wherein the first and second signals transmitted by the first wireless device are transmitted during a variable signal level period of one or more MAC superframes.

35. An article of manufacture including a non-transitory computer readable medium having instructions stored thereon that, in response to execution by a computing device, cause the computing device to perform operations for estimating a location of a first wireless device within a wireless network, the operations comprising:

a second wireless device measuring signal characteristics of a first signal transmitted by the first wireless device at a first power level during a first variable signal level period of a first media access control (MAC) superframe;

the second wireless device measuring signal characteristics of a second signal transmitted by the first wireless device at a second power level during a second variable signal level period of a second MAC superframe, the second power level being different than the first power level; and

the second wireless device transmitting to a location server at least one of (i) the measured signal characteristics or (ii) a range estimated from the second wireless device to the first wireless device.

36. The article of manufacture of claim 35, wherein the operations comprise transmitting to a location server the measured signal characteristics.

37. The article of manufacture of claim 35, wherein the operations comprise transmitting to a location server the range estimated from the second wireless device to the first wireless device.

38. The article of manufacture of claim 35, wherein the first and second signals transmitted by the first wireless device are transmitted during a variable signal level period of one or more MAC superframes.