Turning old TV channels into super Wi-Fi

Advances in TV white space (TVWS) broadband technology have allowed disused TV channels to be repurposed as wireless internet connections

HOW TV WHITE SPACE WI-FI WORKS

Base station:Antenna does not need line of sight

Signal: Follows terrain, through obstacles such as buildings and trees

SCOTLAND Glasgow Isle of Arran Successfully tested in Scotland 30km 19 miles

Avoiding congestion:Geolocation database tells base station which frequencies in its vicinity
are free and can be used

10km

Free space

Rural home:Client radio (speeds of up to 35 megabits per second)

Partners: Nominet and Microsoft are taking TVWS to Africa

WHERE IS TV WHITE SPACE?

Frequency

3kHz 30kHz 300kHz 3MHz 30MHz 300MHz 3GHz 30GHz 300GHz 100km 10km 1km 100m 10m 1m 10cm 1cm 1mm
Very low VLF Low LF Medium MF High HF Very VHF Ultra UHF Super SHF Extremely EHF

Maritime radio, navigation Maritime radio, navigation AM radio, aviation,navigation Short-wave
radio TV, FM radio TV, cell phones, Wi-Fi Satellite signals, Wi-Fi Radio astronomy, satellites

Wavelength Illustrations not drawn to scale

TV white space: Unassigned frequencies, vacated when TV stations switched from analogue signals to digital services

Sources: Nominet, Encyclopaedia Britannica, Carlson Wireless Technologies, E&T, wire agencies