GB1076780A - Improvements in or relating to automatic telecommunication systems - Google Patents

Abstract

1,076,780. Automatic exchange systems. GENERAL DYNAMICS CORPORATION. Dec. 31, 1963, No. 51354/63. Heading H4K. In a time division exchange, means are provided for diverting calls intended for certain subscribers (transferors) to predetermined other subscribers (transferees). A subscriber, e.g. station 1 requiring this facility lifts his receiver whereby a free time slot (4) is allotted to him, and then he dials a special code digit, e.g. 6. The identity of the transferor and the special digit are stored in compartments, corresponding to the allotted time slot, of a calling line store 12 and a terminating line store 6313 respectively (step 1). The number of the time slot is then marked in a delay line transfer store TS4 and the code is deleted from 6313 (step 2). The transferor dials the number of the transferee (station 3) into the terminating store (step 3) and hangs up. If now another subscriber, e.g. station 2 calls station 1, their respective identities are stored in compartments of stores 12 and 6313 during a time slot, e.g. 5 allotted to the new call (step 4). A line number counter 123 successively provides at its output, for a space of two time frames, the identity of every subscriber in the system. When this output next identifies station 1 therefore, two comparators which are connected to stores 12 and 6313 respectively, provide output signals whereby the number of the time slots, e.g. 4 and 5, containing this identity are passed to a second transfer store TS45 and the identity of station 1 is deleted from time slot 5 of store 6313 (step 5). When the output of counter 123 identifies station 3 (step 6) then, during the first time frame of this output signal, suitable apparatus is set, whereby during the second time frame (step 7) the identity of station 3 is written into the compartment corresponding to time slot 5 of store 6313 and the contents of transfer store TS45 are erased. Station 2 is then connected to station 3 in the usual manner. When both parties hang up, the information in time slots 5 of stores 12 and 6313 is removed (step 8). The information in store TS4 and in time slots 4 of stores 12 and 6313 is deleted only when station 1 dials another suitable code digit. The transferor may initiate diversion of his calls by dialling his own number in place of the special code digit. The transfer store TS45 can only be used for diverting one call at a time, i.e. any call which requires diverting and which is initiated during steps 5 to 7 must either be released or must await release of store TS45.