This book provides a comprehensive description of an opticalcommunications technology known as free space optical--anext-generation communications network that uses optical signalsthrough the atmosphere instead of fiber, RF, or microwaves. Thistechnology potentially offers more complex ultrabandwidthcommunication services simultaneously to multiple users and in avery short time, compared to fiber optic technology. This textpresents established and new advancements drawn from the latestresearch and development in components, networking, operation, andpractices.This book describes the FSO network concepts in simple language.It provides comprehensive coverage in an easy-to-understand,progressive style that starts from the physics of the atmosphereand how it affects optical communications; continues with thedesign of a network node; and concludes with fiberless networkapplications from point-to-point to mesh topology. Important areasdiscussed include:* Propagation of light in the atmosphere and phenomena thataffect light propagation* FSO transceiver design* Point-to-point FSO systems* Ring FSO systems* Mesh-FSO systems and integrating the Mesh-FSO with the publicnetwork* WDM Mesh-FSO* FSO network security* FSO-specific applicationsTo meet the needs of both academia and industry, keymathematical formulas are presented along with descriptions, whileextensive mathematical analyses are minimized or avoided. FreeSpace Optical Networks for Ultra-Broad Band Services serves asan ideal text for network communication professionals who enter thefree space optical communication field, graduate students majoringin optical communications, optical communication engineers,researchers, managers, and consultants.