How white spaces wireless network works at West Virginia University

Vacant TV spectrum extends, links WiFi hotspots.

white spaces
Credit: Michael Gregory Ellis, WVU

West Virginia University is an early adopter of white spaces wireless network technology that employs spectrum traditionally set aside for TV broadcasting. 

white spaces
Credit: Michael Gregory Ellis, WVU

On the platform of a station on West Virginia University’s elevated “personal rapid transit” or PRT system, 21-year-old Gail Jennings, a senior accounting major, web surfs on her Windows tablet. She’s connected to a Cisco WiFi access point at the station, but the AP is connected to something new: a white spaces radio that exploits a big slice of unused TV spectrum. (Read the story version.)

white spaces
Credit: Michael Gregory Ellis, WVU

The Cisco access point plugs into this client-side, software-defined radio from Adaptrum, a startup targeting the emerging white spaces market. The radios can switch channels, channel sizes, and power levels as needed. It handles packet “translations” over the Ethernet connection from the access point.

white spaces
Credit: Michael Gregory Ellis, WVU

This is the white spaces give away: the antenna atop the PRT station. It looks like an old-fashioned TV antenna because it is, only its new-fangled. It’s beaming Gail Jennings’ web surfing packets to the base station a little over a mile away.

white spaces
Credit: Michael Gregory Ellis, WVU

The base station antenna is atop WVU’s Engineering Sciences Building, on a hill, giving it a commanding sweep of surrounding Morgantown, including WVU’s three main campus complexes. With the radio at full power, it can reach up to five miles, providing about 12M to 14Mbps on each 6-MHz channel.

white spaces
Credit: Michael Gregory Ellis, WVU

Coax brings the signal here to Adaptrum’s base station radio, which via Ethernet plugs into a router attached to WVU’s campus network. The radios make use of 90 to 95 percent of the available TV channel, according to the vendor. Every day, the radios have to “call home” to an FCC-certified white spaces database, which tells the radios which channels are occupied by TV broadcasters or wireless microphones and which ones are free.

white spaces
Credit: Michael Gregory Ellis, WVU

Here’s why white spaces are red hot. This Google-generated map shows the available white space channels across the U.S. Note: green indicates more channels and the lighter the green, the more channels there are. West Virginia in fact has 12 high-powered 6-MHz channels. According to Adaptrum, here’s how the math works out for the Mountain State: figure 50 to 100 small cells, each with 12 channels, at 14Mbps each. That’s 168Mbps per cell, times 100 cells, or nearly 17 gigabits of new capacity in a given area.

white spaces
Credit: Michael Gregory Ellis, WVU

And here’s what Gail Jennings was surfing to, via the white spaces backbone: a streaming video of WVU’s “A Place Just Right” 2013 holiday concert. Cheers.