Aviation could seek dedicated frequency spectrum for on-board wireless networks if an industry survey now under way indicated sufficient interest in replacing the kilometres of avionics wiring in aircraft.

Boeing and the Texas-based Aerospace Vehicle Systems Institute (AVSI) are trying to determine whether there is sufficient interest in on-board wireless systems to justify launching a bid for a dedicated international frequency allocation at the World Radiocommunication Conference (WRC) in October.

Obtaining a global spectrum allocation can take up to 10 years, and a declaration of intent must be presented at the October meeting for the frequency request to make it on to the agenda for the next WRC meeting, in 2011, says Jerry Holmes, manager, airborne wireless systems integration, Boeing Commercial Airplanes.

If the October deadline is missed, the next opportunity to get on the agenda will be WRC 2015, says Holmes. Allowing two years for individual governments to ratify an allocation, the earliest the dedicated wireless frequency could be used for aircraft systems would be 2013, slipping to 2017 if the process is not begun immediately.

Today on-board wireless systems use unlicensed bands such as 2.4GHz and 5GHz "that are open to everyone else", says Holmes. This limits applications to non-essential functions that can tolerate interference from other users of the frequencies. Dedicated spectrum with worldwide protection would allow wireless communications to be used for flight-critical functions.

Wireless systems would eliminate wiring harnesses, simplifying assembly, reducing maintenance downtime and providing flexibility to reconfigure aircraft. Weight could be reduced, while reliability should be improved by removing connectors and wiring. Wireless mesh networks connecting aircraft systems could enhance redundancy.

AVSI has identified potential on-board wireless applications, including databases, sensors, health monitoring and environmental control, and "over five" potential frequency bands, says Holmes.

Industry needs to find a frequency that can be dedicated to aeronautical use, with enough separation from adjacent bands to block any "back door" into aircraft systems, he says, but close enough to commercial frequencies that aviation can benefit from the economies of the mass electronics market.

Boeing abandoned plans for a wireless in-flight entertainment system on the 787 because available 5GHz technology could not achieve the throughput required. "When the 787 went to wired IFE people said we were abandoning wireless, and that is not the case," says Holmes. "We see benefits of using wireless to improve the efficiency of building and operating aircraft."

Source: FlightGlobal.com