Wireless optical networks could make vehicles lighter

LED-based wireless optical networks in vehicles could significantly cut the weight of wiring under the hood, not only saving on fuel, but also allowing passengers to tap into visible or infrared spectrum bands in overhead lighting to watch movies or play music.

Radio-frequency (RF) signals are used for smartphones, for hands-free headsets for the driver and passengers, and for multimedia-related applications such as tablet PCs, but RF communication suffers from a congested bandwidth. In contrast, wireless systems benefit from an unlimited and unregulated spectrum.

The University of Warwick’s Roger Green is working to create LED-based optical wireless networks.

Although optical wireless has been explored for some time in aviation, scientists in the University of Warwick’s engineering department are exploring its use in private vehicles. It can be used to communicate between parts inside a car’s engine compartment, such as between temperature sensors and the engine management system, or between the brake and speed-control systems.

Optical wireless can simply use a basic LED, such as those used in flashlights, to send data. In situations where it is best for the beam to be invisible, infrared light can be used instead. It can be installed in the overhead lights for in-car entertainment.

The major advantage of optical wireless is the weight of wiring it can remove from cars, translating into significant fuel savings over the lifetime of a vehicle, the researchers say. But it also reduces manufacturing costs, as LED and infrared light sources are not expensive to make, and it cuts back on the expense of maintaining and repairing wires.

Combined, all these factors spell significant advantages over the current systems for in-car data, which, in the engine, are generally copper wire-based or carbon fiber.

“Optical wireless is relatively unknown at the moment. But it’s not hard to imagine a day when passengers can watch TV streamed through a beam coming from their overhead light, or when parts of the engine can ‘talk’ to each other without wires,” said UW professor Roger Green. “We believe that this technology is poised to come into its own.”

Other benefits include its lack of electromagnetic interference, he said.

The engineers presented their work at the International Conference on Transparent Optical Networks this summer at the university.