Exploring 700 MHz options

At an Insights for Next-Generation ILECs panel in Las Vegas, Vanu Bose declared: “If anyone owns 700 MHz spectrum and is thinking of doing something other than [long-term evolution], with all due respect, I think you're nuts. You'd be going off on your own.”

That's a bold statement, but Bose knows a little bit about radio access networks. In fact, the research from his dissertation at MIT became the foundation of the software-defined radio architecture he now sells at his eponymous company, Vanu. His argument centers around two bullet-points: AT&T and Verizon. The two largest winners of the 700 MHz auction are calling the shots, and as they've both selected LTE as their future 4G technology at 700 MHz, they've pretty much dictated what other spectrum-holders will deploy over their own 700 MHz frequencies.

Why do AT&T and Verizon wield so much power? Bose's argument comes down to economies of scale. The large carriers dictate where the vendors allocate their resources, and at 700 MHz they're pursuing LTE in hopes of landing lucrative contracts with those two operators. If the smaller license-holders want to tag along for the ride, that's fine, but the big vendors won't be building any new product lines just to land a 100,000-population coverage network in Utah. There has been talk from the WiMAX Forum about certifying equipment at 700 MHz, but that talk has died down since AT&T and Verizon laid out their LTE plans.

It's feasible that some of the smaller broadband wireless equipment vendors will develop a WiMAX kit at 700 MHz. But then a different set of scale economics kicks in. Devices are a key part of the 4G business model: Embedded consumer electronics and handheld computers are supposed to be the new devices of the 4G age, but consumer electronics- and handset-makers need to be assured of millions of units in volume before they start building their fancy gadgets.

So Bose is expressing the industry's common wisdom, which seems to condemn the hundreds of individual 700 MHz winners to wait for the next three years until AT&T and Verizon are ready to deploy their LTE networks. Not everyone wants to wait, however — including one operator in Sioux Falls, S.D., that has already bucked common wisdom.

Redwood Wireless owns PCS licenses in Minnesota and South Dakota, but instead of launching CDMA, GSM or UMTS over the spectrum, it opted to go broadband using iBurst technology. Developed by ArrayComm and built by Kyocera, iBurst is a spatial division multiple access technology primarily used in public safety data networks around the globe. Redwood uses the network for public safety, offering uninterrupted broadband connectivity to police cars racing down the freeway, but it also sells the service to Sioux Falls residents and businesses, offering 1 Mb/s download speeds for $20 a month, with true mobility to boot.

The Redwood service is an awful lot like the 4G services large operators have been going on about for two years but still haven't built. In an interview, Chris Doolittle, markets director for Redwood, said he has no problem with the proprietary nature of the technology. In fact, Redwood is considering expanding iBurst, deploying it over the 700 MHz spectrum it acquired at auction.

“We decided to get our feet wet with iBurst,” Doolittle said. “We wanted to have a mobile product, not a nomadic product. iBurst can hand off at 70 mph, while some of these WiMAX products are still in the beta stages of mobility.”

Redwood will test WiMAX kits, and it will test LTE kits when they finally become available. Doolittle is conscious of the fact that both technologies will be supported on the larger operators' networks. Right now an iBurst home gateway or laptop card runs about $200. Getting that cost below $100 would be ideal, something that the LTE ecosystem will most certainly do. But Doolittle isn't prepared to wait the three years for those devices to become available, nor is he convinced that LTE can deliver the performance its boosters claim.

“We would prefer sooner rather than later, but whatever technology we choose has to meet the requirements we have set, and it has to perform the way they say it will,” Doolittle said.