The on-again off-again TV white space (TVWS) discussion is on again. TVWS has been of interest for because it has the potential to make a significant difference in rural broadband coverage. Some even go as far as to say it will “revolutionize” rural broadband. In the December issue of Applied Wireless Technology there is an article that looks into the broadcast segment and how it will play a role in the wireless ecosystem of the future.
What makes this so attractive is the propagation characteristics at 600 MHz. The deployment models are along that of Wi-Fi nets but with much better coverage areas. And that is the hot button.
Wi-Fi, even high-power iterations that tend to be expensive, usually extend out to about 300 meters. Networks in the TVWS MHz band can extend as far as 6.3 miles. Additionally, this frequency is much better at dealing with terrain and delivering signals non-line of sight and penetrating physical obstructions. Wide area coverage and its propagation characterizes versus the stuff above 2 GHz, have earned it the nickname “super Wi-Fi.”
The propagation advantages coupled with its potential range make it very attractive for rural deployment where population is often sparse. With cells capable of such wide area coverage, the cost of deployment is lower as is the base line for ROI.
Seems like a win-win, right? Well, unfortunately, the broadcast industry has concerns over interference. These networks are very close to the remaining TV broadcast frequencies. The concern is that these super Wi-Fi networks have the potential to degrade broadcast signals. Moreover, broadcasters just aren’t crazy about giving up spectrum they have owned for decades, for whatever reasons.
However, that isn’t deterring Microsoft from getting on the bandwagon. They have been investigating white space for internet access since their first TVWS project in 2009. Just about a month ago, they have proposed a program called the Rural Airband Initiative.
It would seem like a market of tens of millions of users that don’t have broadband access would make any number of wireless providers drool with visions of providing content to so many users. But the fact is that the sparsity and distribution of these tens of millions puts the cost per user higher than in concentrated population centers. That, the pushback from broadcasters and interference makes this a bit more complex than some of the other platforms.
Still, the impetus to get the next generation of wireless platforms (5G, Internet of Everything) and the governments push to get broadband out to the underserved is gaining momentum. I cant see this staying dormant too much longer.