O'Reilly logo

Wireless Networks first-step by Jim Geier

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Understanding Light Signals

Light signals have been in use with communications systems for even longer than RF systems. Lanterns would provide a source of light to use with sending codes between ships at sea hundreds of years ago. Light guns are still in use today at many airports as a backup communication with aircraft having malfunctioning radio gear.

Wireless networks that utilize light signals, however, are not as common as these that use radio signals. Light signals generally satisfy needs for special applications, such as building-to-building links and short-range personal-area networks. Some wireless LANs and inter-building products use laser light to carry information between computers.

Light Signal Attributes

A light signal is analog ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required