Since the publication of the first edition of Fundamentals of Digital
Switching in 1983, there has been substantial improvement in digital
switching technology and in digital networks. Packet switching has
advanced from a low-speed data-oriented switching approach into a robust
broadband technology which supports services ranging from low-speed data
to video. This technology has eclipsed the flexibility of circuit
switching. Fiber optic cable has advanced since the first edition and
has substantially changed the technology of transmission. to research in
optical devices to find a still better means of This success has led
switching. Digital switching systems continue to benefit from the
100-fold improvement in the capabilities of semiconductor devices which
has occurred during the past decade. The chip industry forecasts a
similar escalation in complexity during the next 10 years. Networks of
switching systems have changed due to regulatory policy reform in many
nations, including the breakup of the Bell System in the United States,
the introduction of new types of carriers in Japan, competition in the
United Kingdom, and a reexamination of public policy in virtually all
nations. Standards bodies have been productive in specifying new
capabilities for future networks involving interactive and distributive
services through STM and A TM technologies.