GB1182404A - Improvements in or relating to Telecommunications Exchange Systems - Google Patents

Abstract

1,182,404. Automatic exchange systems. SIEMENS A.G. 19 June, 1968 [20 June, 1967; 18 Aug., 1967; 24 April, 1968], No. 29112/68. Heading H4K. Connections between subscribers and relay sets across a switching network are set up by direction from a programme controlled device which is relieved of the burden of decision when a fast response is required. A calling subscriber is initially connected to a dialling relay set which may count loop disconnect impulses and forward each digit to the programme controlled device. When sufficient routing digits have been received, the decision to transfer a connection from a dialling relay set to a speech relay set in the wanted direction is taken by the dialling relay set during an interdigital pause. A relay set put into service for an incoming call effects disconnection of ringing on reply without recourse to the programme controlled device. Discrimination between supervisory signals requiring a fast response, and those requiring a slower response that can be referred to the programme controlled device, can be effected in fast acting circuits serving groups of relay sets. Such circuits may handle the connection of registers for the reception of multifrequency codes and associated signals from pushbutton senders, may determine the point at which a subscriber is transferred from a dialling relay set to an outgoing relay set, and may effect the disconnection of ringing tone for an incoming connection. The programme controlled device or the fast acting relay group circuits may refer special service tasks to a special service processor handling such tasks as providing conversions of abbreviated dialling codes, conversions of subscriber addresses, call charge rate computation and storing, and administrative functions in general.