There are many situations where enterprises are challenged to provide sufficient bandwidth to all buildings in a campus environment. Laying fiber and using Telco facilities are very expensive, and lower frequency point-to-point wireless solutions do not have the required capacity. Fortunately there are a couple of wireless solutions that can deliver highly available symmetrical gigabit speeds at distances of up to six miles.
There are really two options to deliver gigabit wireless point-to-point connectivity. The first is very high-frequency millimeter Wave (mmW) wireless, and the second is laser-based Free Space Optics (FSO). There are several alternatives for lower bandwidth requirements, but if gigabit connectivity is required the above solutions are the only options.