GB1428459A - Telecommunication networks and method of operation thereof - Google Patents

Abstract

1428459 Automatic exchange systems HASLER AG SIEMENS-ALBIS AG and STANDARD TELEPHON UND RADIO AG 27 Feb 1973 [29 Feb 1972 (2)] 9508/73 Heading H4K In a digital telecommunication network, each of a number of multiplex terminals T, multiplex register into WE, and switching stages DE are considered as separate circuits blocks and the circuit blocks are interconnected using t.d.m. highways of a standard type. One such system further includes a stored program controlled processor ZSW, a non- blocking switching network DNW, analogue telephone subscribers TA, analogue concentrators A-KZ, digital telephone subscribers DT, digital concentrators D-KZ and digital teleprinter or data subscribers FT. The multiplex units T, which include A-D converters, the digital concentrators D-KZ, the register units WE, switching stages DE and the processor ZSW are interconnected by pairs of 32 channel t.d.m. highways M, one of each pair for each direction of transmission, employing a 128 Ás. frame duration and each highway includes at least one time slot for use as a control channel, one end of each highway being connected to a switching stage DE, the switching network DNW switching control as well as speech information. All highways emanating from the processor carry only control information whereas all other highways may carry control, speech and/or signalling information. To guard against faults, each switching stage is controllable from the processor ZSW via at least two separate paths, e.g. switching stage DE1 can be controlled directly using a channel of highway M1 or indirectly via highways M2, M8, M4. When the network is made operative, the processor ZSW establishes a path through the switching network to each peripheral unit with the aid of a control path search program, these paths remaining established until, due to a fault, the establishment of a new path is necessary.