Internet via Light Coming To Your Home
by Lloyd Alter, Toronto on 09.12.07
Transmitting information in a beam of light isn't new; Alexander Graham Bell patented the photophone in 1880 and thought it was his greatest invention. Free-space optics (FSO) are used now between office buildings and on university campuses to avoid stringing cables. According to the Economist, it may be coming into our homes. It is fast and secure; "since light does not travel through walls, there would be no need to worry about neighbours snooping on your e-mail, or piggybacking on your broadband connection."
What is really interesting is the tie-in to our continuing discussions about alternative wiring systems and the integration of lighting into the fabric of buildings as we switch to LEDs. No more EMF or separate wiring systems. "The combination of LEDs and FSOcould be used to provide internet coverage throughout a home or office. Could it be lights out for radio networking?" ::Economist
The death of radio networking? We use radio waves BECAUSE they can pass through obstacles, like walls.
Line of site transmission has limited applications, like remote controls and automatic toilet flushers.
When I was in college we had to design a network for our campus as a project. My group decided to use this system rather than fiber optics to connect the buildings.
Rather than digging up the grounds and running fiber optics through foundations, these devices just sit on the top of buildings. The cost savings and convenience of not tearing up the campus more than makes up for the higher price.
The problem with WiFi is that it's not fast enough yet, and can be hacked unless you use WPA encryption. These eliminate this problem for infrastructure networks, allowing you to segment your WiFi in some sort of sandbox to prevent unauthorized use.
Bear in mind that these aren't for network endpoints, but to allow communication between buildings. Ideally they'll be set up in a mesh system that will automatically adapt to changing conditions. Devices would still use WiFi and Ethernet to connect to the network.
(We got the highest grade on that project.)