Optical Internet Backhaul

Optical communication provides significantly better transmission speeds than copper wiring or conventional wireless communications, and so for high-traffic, high-speed networks fiber optic cable is generally used. Free space optical systems are used for relatively short links where the speed of optical communications is desired but using fiber optic cable is not a viable option. For example, Stanford Hospital uses an optical link between two nearby buildings (~1km apart) which need rapid access to a shared network and which could not be cost-effectively linked by fiber.

One major problem with this approach is that it is highly susceptible to fluctuations in weather. A small rainstorm (or even fog) will typically break a link like this.