Automatic selection of special services - connecting telephone subscriber to electronic exchange by information previously stored by subscriber by special key selection

摘要

The objective of the modified branch exchange circuitry is to make special facility connection frequency used easier to access by the subscriber. Examples are the storage of frequently called numbers, the selection of particular call rerouting, or the setting up of regularly used conference circuits. The exchange principally contains a control unit, an evaluator and coordinator with read-write memory. With these are the necessary peripheral logic circuits. Lifting the receiver transmits to the exchange a start and extension number signal. If an extension number is then keyed in from the telephone unit action in the exchange is normal. If, however, two special keys are pressed in succession, for instance, and one of four 'others,' the processor at the exchange opens a route to the memory. An instruction can then be entered in a place referenced by the extension number. For future use then only the combination of special keys need be pressed to obtain the entered service.