Airborne antenna maker AeroSat is developing an in-flight internet system that aims to provide high-speed connectivity at up to 45Mb/s for passengers, crew and air traffic control centres.
The system, which is independent of satellite transmissions, will use several high-capacity ground stations and aircraft equipped with smaller, less expensive antenna systems to create an aircraft-to-aircraft relay communications system.
Over the North Atlantic Ocean, only seven suitably spaced aircraft would be required to provide unbroken air-to-air connectivity for all aircraft within a 480km (260nm) range of each other, says AeroSat.
As a result, airborne internet "has the potential to form the basis of a general purpose, broadband aviation communications network capable of supporting in-flight entertainment and passenger communications, general air transport management, flight operations, maintenance, and safety and security communications".
AeroSat first started working on this solution in 1997 in response to the industry's cost concerns about satellite-based connectivity systems.
Direct communications from the ground to the aircraft was evaluated, but that required covering the Earth with antennas, says AeroSat. "This was not only expensive, but also impractical for remote areas and areas over the ocean."
Instead, AeroSat scientists focused on a solution that would pass data from the ground to an aircraft within line-of-sight. The aircraft could communicate directly with other aircraft up to 480km away. "By passing the data from aircraft to aircraft and forming links, it is possible to move data at very high speeds and very low cost to even remote areas over the ocean," says the company.
AeroSat was awarded a US patent in October 1999 for the antenna and the communications methodology.
But other regulatory hurdles may yet remain. In 2006 the US Federal Communications Commission auctioned 4MHz of spectrum in the 800MHz band allocated to air-to-ground services. Aircell won the exclusive 3MHz licence to provide wireless broadband services on commercial aircraft, while JetBlue subsidiary LiveTV acquired the 1MHz narrowband slice.
It remains to be seen if other air-to-ground approaches - even those with a limited air-to-ground element - can or will be permitted or accommodated.