PRIVATE AUTOMATIC BRANCH EXCHANGE WITH CENTRAL OFFICE FEATURES

摘要

A private branch automatic exchange system of substantially unlimited size which includes the combination of a central office with an operator complex, including a plurality of operator position circuits connectable to a plurality of trunk circuits through an operator service link network and a plurality of transfer circuits which make available call transfer to subscribers having the proper class of service in combination with a central office including a line link network, a trunk link network and a service link network through which subscribers may be connected to one another and to selected trunk circuits under control of common control equipment.