Telephone challenges: a plethora of services

Technical advances and changes in the regulatory climate in US telephony since the court-ordered divestiture of AT&T Company in 1984 are examined in this second of a series of articles (for previous article, by G. Zorpette, see ibid., vol.27, no.5, p.28 (1990)). A set of services based on Custom Local Area Signaling Service (Class) technology, introduced in New Jersey in 1987, provides caller identification, call block, priority call, return call, repeat call, select forward, and call trace. Throughout the USA it is being rolled out at varying clips, depending on state regulatory climates and the pace of technology upgrades in the network. Class is usually based on Common Channel Signaling System 7 (SS7) software, but can also be implemented by the Advanced Intelligent Network, which puts the control software in a computer outside the switch so that computers more powerful than switch hardware can manipulate a call. Other major trends discussed are the growing use of cordless telephones, cellular telephony, voice mail, and computers replacing human operators.<
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