In 2008 it was billed as a technology that would usher in a new era of broadband. Three years later, many vendors are still looking for a business case.
The potential of white space--the slivers of 700 MHz spectrum freed by the transition of TV channels from analog to digital--hit a fever pitch in 2008 when the FCC voted to move ahead with the conditional unlicensed use of white space spectrum.
Big players such as Google (NASDAQ:GOOG), Microsoft (NASDAQ:MSFT) and Motorola (NYSE:MMI) lobbied the commission for approval. Larry Page, co-founder of Google, declared white space to be "WiFi on steroids" since the spectrum promised significantly longer range than WiFi technology using base stations.
After two years of debate and comment, the FCC voted 5-0 in September to approve rules for white-space devices--officially kick starting the market. However, the business case for white space services is anything but clear to those playing in the WiFi market.
Technical realities stymie white space potential
There are few TV white space channels available in urban areas, where demand for high-speed, WiFi-like services will be highest. White space devices must use geolocation data from databases to determine what frequencies to use, thereby preventing interference with TV broadcasts and other signals. But with heavy use of the spectrum in big markets such as Los Angeles and New York, very few channels will be available for use at a given time.
Moreover, the TV band is divided into 6-megahertz channels, which will severely limit white space data speeds. In comparison, 802.11n systems take advantage of 20 megahertz to 40 megahertz of spectrum and offer data speeds of about 65 Mbps.
Further, the FCC imposed strict out-of-band emission requirements, which means WiFi vendors cannot easily convert existing WiFi equipment and chips to work in white space spectrum since additional filtering techniques will be required.
"It's definitely a different band from the 2.4 GHz band, and there are all sorts of twists when it comes to operating in this (white space spectrum)," conceded Greg Ennis, technical director with the WiFi Alliance.
Narasimha Chari, co-founder and chief technology officer with WiFi mesh provider Tropos Networks, which plays in the smart grid and smart-city space, agrees. "It is attractive but very challenging," he said. "We're trying to work through at a system architectural level now to see how we can take advantage of it."
The WiFi Alliance and other white-space advocates have issued a Petition for Reconsideration with the FCC over the strict emission rules, which were put in place to placate the broadcast television industry that has long been concerned about potential interference from white space devices. Meanwhile, the IEEE has established a white space group with the aim of developing a specification. Ennis said the WiFi Alliance likely will begin certifying white space products in the 2012 timeframe, after the IEEE develops the spec.
Tougher emission requirements will make equipment more expensive in the beginning, but aren't a deal breaker, Ennis said. Indeed, technical problems can always be overcome if there is a strong business case for a particular technology, said Victor Strom, chief wireless architect and founder of WiFi vendor Ruckus Wireless.
"The ecosystem has to come together. And the question is: Who do you sell it to?" said Strom, who noted that his company is studying the white space market.
White spaces go rural
With usable white space spectrum scarce in bigger markets, many have said the technology is more suited for rural broadband connectivity--wireless ISPs have been clamoring for white space radio waves to push wireless services into hard-to-reach areas.
Neeraj Srivastava, vice president of marketing and business development with Spectrum Bridge, points to a split market for white space services: One is high-powered, point-to-point solutions that can be deployed today for rural broadband, and the other is the traditional access-point market that still has to be standardized by the IEEE.
Spectrum Bridge, which hopes to become a white space database provider, is already testing the business case for point-to-point solutions in various markets. The company built out a network in Claudeville, Va., a small rural community lacking broadband connectivity, to show how white spaces can bridge the "digital divide." Two years ago the city of Wilmington, Del., and the county of New Hanover, N.C., launched a white space network using an experimental license to develop what Spectrum Bridge calls the nation's first smart-city network powered by the vendor's white space database. And in September, Google and Spectrum Bridge, together with the Hocking Valley Community Hospital, announced the deployment of the first white space broadband network trial for healthcare providers in Logan, Ohio.
One radio maker that is ready to take on the point-to-point white space market is Carlson Wireless, a microwave and public-safety specialist. CEO James Carlson said that if the FCC's timetables hold steady for equipment certification, his company should come to market with the first software-defined radio for the white space market early this year.
Carlson unveiled the RuralConnect IP radio during the California Wireless Internet Service Providers Association meeting last month, and the CEO said he sees a market not only for rural broadband services but municipal and smart energy applications in smaller markets where white space spectrum is more plentiful.
Meanwhile, the super WiFi vision is in limbo, and it will likely be companies like Spectrum Bridge and Carlson proving out business cases in smaller markets.