A few years ago, I wrote about how low-band VHF TV channels were being used in Australia to beam Internet service to remote communities. Now this will be tried in the United States, The FCC has granted Full Spectrum experimental license WE2XZQ to operate on frequencies between 42.96–44.60 MHz and 47.68–49.58 MHz “for testing broadband mobile and fixed IP communications.”
Full Spectrum's application, available through the FCC Experimental Licensing System Call Sign Search, states the experimental operation will use channel sizes ranging from 200 kHz to 1 MHz. The application indicates a transmitter power of 4 W and an ERP of 12.649 W. The system will use OFDM modulation and the WiMAX-e (IEEE 802.16e) air interface protocol with modifications to support low-band VHF frequencies in narrow channel sizes.
Full Spectrum is developing the technology to support requirements of electric utilities that need broadband IP-based networks to support new smart grid applications such as remote control of automated voltage regulators, capacitor banks, and automatic metering back-haul. The application states that by using these low frequencies in narrow channels, wide area coverage can be provided with a minimal tower infrastructure.
Full Spectrum said the utility applications require coverage of up to 20 miles from a tower site in varying terrain with high quality of service (QoS).
Other interesting license grants in the FCC Experimental Actions granted from May 1, 2009 to June 1, 2009 [PDF] include two for testing communications in medium and shortwave spectrum between 2 and 30 MHz. General Dynamics was granted a license to operate in 3–7 MHz and 15–21 MHz “for propagation studies for development of potential enhancements to customer radio equipment and procedures for operation in the high frequency (HF) band” at Nellis AFD in Nevada. Datron World Communication received a grant to operate on several specific frequencies between 2 and 30 MHz “to test and develop standards for adaptive HF, VHF, and UHF radio equipment” in Vista, Calif.
Except for two licenses for operations covering a wide frequency band for antenna testing in Sacramento, Calif. and Litchfield, N.H., the grants do not include any broadcast frequencies.
Low-Band VHF DTV Revisited
My March 10 column "DTV on Low-Band VHF Channels" generated a large amount of e-mail. Many of the comments described experiences receiving low-VHF analog and DTV stations (Channels 2-6) and a few others focused on the reasons low-VHF DTV reception is difficult. This month I'll share some of those comments with you and offer some ideas on why low-VHF DTV reception is such a challenge.