I have been reading through the new TV White Spaces rules and it occurred to me that if the wireless radio manufacturers could get away from half duplex radios running on the same frequency, fixed Wireless Internet Service Providers (WISP’s) could actually use the first adjacent TV channels for outdoor wireless broadband systems. Read the full blog here
Diagram of split transmit and receive equipment design for TV Whitespaces which would allow use of the spectrum in Metro markets
Below you will find a link to a Google Earth mapping file that allows you to investigate the possible availability of TV white space spectrum. While this is not an all inclusive tool based on the final adoption of white spaces rules, it will give you an idea of which channels will be available based on your desired use. The existing TV contour files are from the FCC database and current as of August 2010.
PLEASE TAKE NOTE, this is not the authoritative database for White Space available channels and/or service areas. It is a general planning tool to allow an individual to look at an area to investigate the POSSIBILITIES of how much spectrum may be available in their given area and/or region. The FCC rules have not been completely finalized. The Google Map file does not include all the data that must be considered for the proper protections to licensed broadcasters, cable head ends, the T-Band land mobile radio cities and the radio astronomy sites around the country.
To use the file you will need to download the free Google Earth program at http://earth.google.com
Download the 20 meg kmz file below and open it within the Google Earth mapping program. In your places pane you can expand the folder to reveal all of the different TV channels by number. Turn them on one at a time to see if there are any licensed TV broadcast systems in your area. For low power consumer devices any channel above 20 that is not labeled as protected should be usable. For high power fixed wireless broadband systems you will need to turn the channel on above and below the channel you think might be available. The are the first adjacent channels and need to be protected as well as the channel(s) you wish to use.
In addition to the standard TV contours you will also need to protect a 134 km radius around the cites in the chart below on the channels mentioned for each city.
Urbanized area Geographic center Bands (MHz) TV channels North latitude West longitude Boston, MA ..........................42°21′24.4″ .......................... 71°03′23.2″ .......................... 470–476, 482–488 14, 16 Chicago, IL ...........................41°52′28.1″ .......................... 87°38′22.2″ .......................... 470–476, 476–482 14, 15 Cleveland, OH .....................41°29′51.2″ .......................... 81°49′49.5″ .......................... 470–476, 476–482 14, 15 Dallas/Fort Worth, TX ..........32°47′09.5″ .......................... 96°47′38.0″ .......................... 482–488 16 Detroit, MI ...........................42°19′48.1″ .......................... 83°02′56.7″ .......................... 476–482, 482–488 15, 16 Houston, TX ........................29°45′26.8″ .......................... 95°21′37.8″ .......................... 488–494 17 Los Angeles, CA 4 ...............34°03′15.0″ .......................... 118°14′31.3″ ........................ 470–476, 482–488,506–512 14, 16, 20 Miami, FL ............................... 25°46′38.4″ .......................... 80°11′31.2″ .......................... 470–476 14 New York, NY/NE NJ ............ 40°45′06.4″ .......................... 73°59′37.5″ .......................... 470–476, 476–482,482–488 14, 15, 16 Philadelphia, PA .................... 39°56′58.4″ .......................... 75°09′19.6″ .......................... 500–506, 506–512 19, 20 Pittsburgh, PA ........................ 40°26′19.2″ .......................... 79°59′59.2″ .......................... 470–476, 494–500 14, 18 San Francisco/Oakland, CA .. 37°46′38.7″ .......................... 122°24′43.9″ ........................ 482–488, 488–494 16, 17 Washington, DC/MD/VA ........ 38°53′51.4″ .......................... 77°00′31.9″ .......................... 488–494, 494–500 17, 18
There will also be translator and cable head end protection areas as well as specific areas around the radio astronomy sites that will require specific protections.
Some definitions from the FCC ruling which may help in investigating available TVWS channels:
(c) Fixed device. A TVBD that transmits and/or receives radiocommunication signals at a specified fixed location. A fixed TVBD may select channels for operation itself from a list of available channels provided by a TV bands database, initiate and operate a network by sending enabling signals to one or more fixed TVBDs and/or personal/portable TVBDs. Fixed devices may provide to a Mode I personal/portable device a list of available channels on which the Mode I device may operate under the rules, including available channels above 512 MHz (above TV channel 20) on which the fixed TVBD also may operate and a supplemental list of available channels above 512 MHz (above TV channel 20) that are adjacent to occupied TV channels on which the Mode I device, but not the fixed device, may operate.
(i) Personal/portable device. A TVBD that transmits and/or receives radiocommunication signals at unspecified locations that may change. Personal/portable devices may only transmit on available channels in the frequency bands 512-608 MHz (TV channels 21-36) and 614-698 MHz (TV channels 38-51).
(m) Television band device (TVBD). Intentional radiators that operate on an unlicensed basis on available channels in the broadcast television frequency bands at 54-60 MHz (TV channel 2), 76- 88 MHz (TV channels 5 and 6), 174-216 MHz (TV channels 7-13), 470-608 MHz (TV channels 14-36) and 614-698 MHz (TV channels 38-51).
(a) Power limits for TVBDs. (1) For fixed TVBDs, the maximum power delivered to the transmitting antenna shall not exceed one watt; this maximum applies regardless of the number of TV channels on which the device operates. The power delivered to the transmitting antenna is the maximum conducted output power reduced by the signal loss experienced in the cable used to connect the transmitter to the transmit antenna. If transmitting antennas of directional gain greater than 6 dBi are used, the maximum conducted output power shall be reduced by the amount in dB that the directional gain of the antenna exceeds 6 dBi. (2) For personal/portable TVBDs, the maximum EIRP shall not exceed 100 milliwatts (20 dBm) with the following exceptions; Mode II personal/portable TVBDs that do not meet the adjacent channel separation requirements in § 15.712(a) and Mode I personal/portable TVBDs that operate on available channels (provided by a Mode II TVBD) that do not meet the adjacent channel separation requirements of § 15.712(a) are limited to a maximum EIRP of 40 milliwatts (16 dBm). These maximum power levels apply regardless of the number of TV channels on which the device operates.