Page 37 - Optical Switching And Networking Handbook

22 Chapter 1

Figure 1-11
The combination Amplifier Amplifier
of TDM and FDM
on fiber

Signal weakening

apparent that light waves had an enormous capacity for carrying
information and were immune to electrical interference.Advances in
lasers, light-emitting diodes, repeaters, connectors, photodetectors,
and glass fibers in the following decades—and the realization that
they could be fabricated and installed as integrated components—
led to the installation of the first light-wave system in an operating
telephone company in 1977.
This installation was the world’s first light-wave system to provide
a full range of telecommunications services—voice, data, and video-
over a public switched network. The system, installed over about 1.5
miles under downtown Chicago, used glass fibers that each carried
the equivalent of 672 voice channels (a T3).

Growth in Fiber-Based Systems

More than 15.5 million miles of fiber had been installed worldwide
by the end of 1997. Construction continues growing at an endless
pace that should reach 30 million miles by the end of 2001. China
and the Far East market is expected to grow three times during the
period of 2000-2003.
The services using fiberoptic systems are provided by all the
telecommunications providers/carriers.The long-distance companies
(AT&T, MCI/WorldCom, British Telecom) have been using fiberoptics