Digital switching center
AssigneeThe Post Office
InventorPeter Alexander Birnie
Life of this patent
Estimating the term…
Abstract
A switching center having a plurality of sets of buffer stores for connecting the channels of a plurality of pulse code modulated signal systems to the inputs of a multiplexer in which there is provided a unit for generating a false busy signal to prevent the reading of a buffer store at a time close to the time of writing into the store to reduce the possibility of simultaneous reading and writing and the consequent corruption of information.
Claims7
A digital switching centre having a first set of signal stores connected to receive the signals of a set of pulse code modulation (P.C.M.) signal systems respectively, each signal store having a plurality of registers for storing signals of a respective plurality of channels of the particular PCM signal system, a control means and a switching means responsive to the control means and connected to derive signals from the signal stores of the first set at selected times so as to establish selected signal transfer paths from registers of the signal stores, wherein there is provided means responsive to signals from the particular PCM signal system for producing an indication of the time of occurrence of a selected channel of the system, the control means being responsive to the indication to prevent the establishment of a particular signal transfer path from the register for storing signals from the selected channel if that path would result in there being less than a predetermined interval of time between the reception of signals by and the derivation of signals from the register for storing signals from the selected channel.
Dependencies are inferred from the claim text.