By: MarkJ - 30 January, 2010 (8:17 AM) - Views: 11805 - Categories: Wi-Fi

The Pennsylvania State University has developed a new method of indoor Optical Wireless network that does not require a line-of-sight and runs at speeds of 1Gbps+. The setup uses multi-element transmitters and multi-branch optical receivers in a quasi-diffuse configuration (*head explodes*) and could eventually replace Wi-Fi.

The system uses a high-powered laser diode -- a device that converts electricity into light -- as the optical transmitter and an avalanche photo diode -- a device that converts light to electricity -- as the receiver. The light bounces off the walls and is picked up by the receiver.


Traditional radio frequency systems ( Wi-Fi , WiMAX , 3G etc. ) do not require line of sight transmission, but can pass through some substances and so present a security problem. Light, in a room without windows, will not escape the room, improving security, but also allowing the same frequencies to be used in adjacent rooms without interference.

Multiple sensors could allow the light signal to pass from room to room or even from floor to floor. The system could also be set up to convert the signal to electricity, transfer it to another location and change it back to light. Optical systems can also operate in locations where radio frequency transmission would interfere with other equipment.

There are certainly some clear advantages to the technology, although traditional wireless networks are already approaching similar speeds and have the added advantage of being cheap. They also do not require additional relay stations (in small home environments) to push the signal around additional rooms. In any case it's a long and slow road from the lab to a commercial product.