ENABLING WHITE SPACE NETWORKS INDEPENDENT OF LOW-THRESHOLD SENSING

• US 20110317019A1
• Filed: 06/24/2010
• Published: 12/29/2011
• Est. Priority Date: 06/24/2010
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Bahl, Paramvir, Chandra, Ranveer, Moscibroda, Thomas, Murty, Rohan Narayana
• Granted Patent: US 8,473,989 B2
• Time in Patent Office: Days
• US Class Current: 348/180
• CPC Class Codes: H04L 27/0006 Assessment of spectral gaps suitable for allocating digitally modulated signals, e.g. for carrier allocation in cognitive radio for spectrum sharing between different networks H04W16/14
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00

Abstract

Described is a technology by which a remote or local geo-location service provides white space information that one or more client devices and/or base stations may use to determine which white spaces are available for use, e.g., for wireless networking. Because of the information, low-threshold sensing is not needed by the client devices and/or base stations to know which white spaces are available. The service computes the available white spaces for a given location based upon television transmitter parameters, elevation data, and information received regarding any operational wireless microphones.

Claims

1. In a computing environment, a method performed on at least one processor, comprising,

determining transmitters of licensed users relative to a location;

computing which unused spectrum are available for use in an area surrounding that location based upon the transmitters; and

disseminating data that identifies the unused spectrum that are available for use in that area.

2. The method of claim 1 further comprising, receiving the data on a client device and operating a wireless network over one of the white spaces.

3. The method of claim 1 wherein determining the primary users'"'"' transmitters comprises accessing television transmitter data corresponding to one or more television towers of television stations that are potentially broadcasting in the area, and accessing elevation data between the one or more television towers and the location.

4. The method of claim 1 wherein determining the primary users'"'"' transmitters comprises using a protection radius to avoid interference with a wireless microphone.

5. The method of claim 1 wherein computing which white spaces are available for use by determining signal attenuation using elevation data and parameters of the transmitters.

6. The method of claim 5 wherein determining the signal attenuation comprises using propagation modeling.

7. The method of claim 6 wherein using propagation modeling comprises accessing relatively high resolution elevation data for use in determining the signal attenuation via terrain-based propagation modeling, determining whether propagation modeling returns an error with the relatively high resolution elevation data, and if so, accessing lower resolution data for use in determining the signal attenuation via terrain-based propagation modeling.

8. The method of claim 7 wherein using propagation modeling comprises determining whether propagation modeling returns an error with the lower resolution elevation data, and if so, using a propagation model without terrain-based propagation modeling.

9. The method of claim 1 further comprising, outputting information from a base station, the information corresponding to a grid of points within the area and availability information corresponding to channels for at least some of the points.

10. A system comprising, a geo-location service that acts as a proxy for determining which parts of a broadcast spectrum are white spaces, the geo-location service determining the white spaces based in part upon data corresponding to television tower parameters and terrain data, and a white space device coupled to obtain data from the geo-location service to determine a white space for communicating data wirelessly over a white space network.

11. The system of claim 10 wherein the geo-location service is located remotely from the white space device, and wherein the geo-location service further provides data corresponding to at least one wireless microphone operating in the broadcast spectrum.

12. The system of claim 11 wherein the geo-location service receives information corresponding to at least one wireless microphone operating in the broadcast spectrum from a microphone updater device.

13. The system of claim 10 wherein the geo-location service is located locally relative to the white space device.

14. The system of claim 13 wherein the geo-location service determines transmitters of primary users relative to a location, and computes which white spaces are available for use in an area surrounding that location.

15. The system of claim 13 wherein the geo-location service determines the white spaces by looking up the white spaces that the white space device has remotely downloaded into a database, in which the data downloaded is provided by a remote source based in part on television tower parameters and terrain data.

16. The system of claim 13 wherein the geo-location service receives information corresponding to at least one wireless microphone operating in the broadcast spectrum from a beaconer device.

17. The system of claim 16 wherein the beaconer device operates in a same broadcast channel as the wireless microphone, or operates on an out-of-band channel relative to the wireless microphone.

18. The system of claim 16 wherein the wireless microphone operates over a UHF channel, and wherein the beaconer device operates over a VHF channel.

19. One or more computer-readable media having computer-executable instructions, which when executed perform steps, comprising:

obtaining a set of one or more transmitters of primary users'"'"' within an area relative to a location;

for each transmitter, determining whether the transmitter is a television transmitter, and if not, applying a fixed protection radius, and if so, retrieving elevation data between a television tower and the location;

for each transmitter, using any elevation data and parameters of the transmitter to determine signal attenuation; and

determining from the signal attenuation a set of one or more white spaces that are available at the location.

20. The one or more computer-readable media of claim 19 having further computer-executable instructions comprising, disseminating data that identifies the one or more white spaces to at least one base station.