Evidence mounts for using white spaces for rural broadband
A trial conducted at Microsoft’s research laboratory in Cambridge, England, late last year demonstrated that using TV white-space spectrum to deliver broadband services to rural and underserved areas — and to fill in urban coverage gaps —works well and without interference to incumbent broadcasters, according to Jim Carlson, president of Carlson Wireless, one of the equipment vendors that participated in the event. The trial, which involved numerous field tests, was conducted over six months.
Other trial participants included broadcasters BBC, BSkyB and Arqiva; telecommunications service provider British Telecom; database providers Spectrum Bridge and Microsoft; and equipment vendors Nokia, Samsung and Neul.
“Using TV spectrum to deliver broadband is important because it is a method that has 5 to 10% of the costs of wired solutions, and in areas where there is low tower density, it’s the biggest bang for the buck,” Carlson said, adding that the cost models are such that such service can be delivered to areas that have no more than 20 homes per square mile.
During the trial researchers discovered that the so-called Super Wi-Fi signals were able to penetrate a wide variety of obstructions, including hills and stone walls, according to Carlson. “So, it worked for both urban and suburban,” he said.
In fact, the propagation characteristics are much better than microwave, which traditionally has been the method of choice for wireless Internet service providers for backhaul, according to Carlson. “For four or five miles, without too many terrain obstructions, the signal penetrattion is pretty good,” he said. “With microwave, you get none of that — if you have some foliage in the way, you’re done.”
Researchers also discovered during the trial that Super Wi-Fi is a viable means of providing connectivity to rural areas because the signal can travel over much longer distances than traditional Wi-Fi, which operates in the 2.4 GHz band—up to six times farther, Carlson said. This is important because the U.K. has 2.5 million people who currently are in need of broadband, he said.
The ability to bring broadband to such areas will have myriad benefits, Carlson said. Among them are distance learning and telemedicine.
One of the disadvantages of Super Wi-Fi gear is that it is more expensive than Wi-Fi equipment. Currently, Carlson Wireless sells its RuralConnect radio — which was developed jointly with Neul — for $590, but Carlson expects the price to be cut in half within three years as chipsets become more streamlined and efficient.
This week Carlson Wireless announced that it is expanding the RuralConnect line — again, in partnership with Neul — with a line of omnidirectional and sectoral, high-gain, base-station antennas.