The document summarizes free space optical communication (FSO). It discusses the operation of FSO links, their advantages over fiber and microwave links, and applications. The key points are:
1. An FSO link consists of a transmitter, receiver, and tracking system to direct light beams between nodes. It allows license-free, high-speed connections but is susceptible to weather.
2. Applications include point-to-point links between buildings and potential mesh networks or use on high altitude platforms. Mesh networks provide better coverage but at a higher cost than point-to-point links.
3. Compared to fiber and microwave links, FSO systems have lower costs and power needs but higher data rates and