U.S. Again Urged Not to Share Connected-Car Broadcast Spectrum

Carmakers and state transportation departments have renewed their fight to block efforts that would allow broadcast spectrum set aside for connected vehicles to be shared by other wireless devices.

The spectrum—75 megahertz within the 5.9 GHz band—was reserved in 1999 by the Federal Communication Commission for short-range vehicle safety systems. Development of so-called V2V (vehicle-to-vehicle) communications has accelerated in recent yearrs. But little has been done to implement the technology.

V2V would enable vehicles to automatically notify nearby traffic of their location, direction and speed. Proponents say such capability could be used to reduce crashes in the U.S. by 80%. The U.S. Dept. of Transportation suggested in January that V2V capability be required in future vehicles.

In the meantime, the exponential growth of wireless services threatens to overload the separate broadcast spectrum set aside for those purposes. Backers of wi-fi services have been clamoring for at least a piece of the still-unused V2V spectrum for more than three years. They describe their available spectrum as “perilously insufficient.”

Carmakers, who say V2V systems are finally near, fret that sharing spectrum with wi-fi services could cause signal interference and cause safety problems for V2V-equipped vehicles. They are urging regulators to withhold any decision about spectrum-sharing until DOT, the FCC and the U.S. dept. of Commerce complete tests to resolve the interference debate.