Space Data, a losing bidder on commercial air-to-ground spectrum, has lofty goals: The company didn't win the 1 MHz license in the 800 MHz spectrum auction--JetBlue's LiveTV division snagged it for over $7m--but they are moving ahead with their fill-in cell tower offering. They loft lightweight cell transmitters to 20 miles using inexpensive balloons. The transmitters, which carry juice for 8 to 10 hours of operation, can function to as much as 420 miles in diameter. (Their site says 420 miles in diameter; the article says, imprecisely, 50 to 500 miles.)
The trick is that the transmitters are designed to parachute to safety and be recoverable through embedded GPS locators and transceivers, but new transmitters must be launched constantly. This could add up to $100,000 to $300,000 per cell site per year, but this could be substantially cheaper than any comparable terrestrial option for remote areas or areas with zoning issues. The technology is currenty used by oil companies in some southern and southwestern states to track vehicles and monitor production.
No word on how transmitters that land on private property are recovered.
In the air-to-ground 800 MHz spectrum auction, Space Data won a ruling that allowed them to use their balloons to communicate with aircraft, which might have obviated a chunk of the ground stations they would otherwise have had to build, but they lost permission for secondary licensing of the spectrum, which would have allowed unrelated terrestrial-only use. (If that had been permitted, the auctions would have been much more valuable. In an interview today, AirFone founder Jack Goeken said that GTE bought AirFone way back when because it wanted the secondary use of the spectrum that AirFone had for ground mobile devices.)
Space Data has competitors, which include Sanswire Networks, which proposes unmanned 13-mile up solar-powered blimps that will stay fixed in place, and carry transmitters for cellular networks and Internet access. Straight up offers excellent line of sight.