1Gbps Optical Wireless Networking Could Replace Indoor Wi-Fi

January 30, 2010 – Pennsylvania State University has developed a new type of indoor optical wireless network that doesn’t require line of sight and runs at speeds in excess of 1Gbps. The networking setup uses multi-element transmitters and multi-branch optical receivers in a quasi-diffuse configuration and has the strong potential to replace Wi-Fi. The system uses a high-powered laser diode as the optical transmitter and an avalanche photo diode as the receiver. The light bounces off the walls and is picked up by the receiver.

Jarir Fadlullah, a graduate student in electrical engineering, said: “The optical system we have offers a very large bandwidth thus a very high speed. We can send one gigabit per second or more over a gigahertz band. Unless the walls are painted solid black, there is no need to worry about transmission within a room.”

Traditional RF systems 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.