Switching system for PCM communication with alternate voice and data transmission

Claim 1

IN A PULSE-CODE-MODULATION SYSTEM, IN COMBINATION: A CENTRAL OFFICE; A PLURALITY OF OUTLYING STATIONS CONNECTED TO SAID CENTRAL OFFICE VIA RESPECTIVE SIGNAL PATHS, SAID STATIONS BEING PROVIDED WITH DATA-COMMUNICATION EQUIPMENT CONNECTED TO SAID SIGNAL PATHS; PROGRAMMING MEANS AT SAID CENTRAL OFFICE FOR ESTABLISHING A RECURRENT FRAME COMPOSED OF A MULTIPLICITY OF MESSAGE CHANNELS EACH CONSTITUTED BY A RESPECTIVE TIME SLOT IN SAID FRAME; INCOMING AND OUTGOING REGISTER MEANS AT SAID CENTRAL OFFICE EACH HAVING A NUMBER OF STAGES CORRESPONDING TO THAT OF SAID CHANNELS, EACH OF SAID STAGES BEING PERMANENTLY ASSOCIATED WITH A RESPECTIVE CHANNEL; INPUT MEANS AT SAID CENTRAL OFFICE FOR RESPECTIVELY DIRECTING DATA SIGNALS FROM A FIRST AND A SECOND STATION TO A FIRST AND A SECOND STAGE OF SAID INCOMING REGISTER MEANS ASSOCIATED WITH A FIRST AND A SECOND CHANNEL ALLOCATED TO SAID FIRST AND SAID SECOND STATION, RESPECTIVELY; OUTPUT MEANS AT SAID CENTRAL OFFICE FOR DIRECTION DATA FROM A FIRST AND A SECOND STAGE OF SAID OUTGOING REGISTER MEANS, RESPECTIVELY ASSOCIATED WITH SAID FIRST AND SECOND CHANNELS, TO SAID FIRST AND SECOND STATIONS, RESPECTIVELY; TRANSFER MEANS AT SAID CENTRAL OFFICE CONTROLLED BY SAID PROGRAMMING MEANS FOR PERIODICALLY DELIVERING THE CONTENTS OF SAID FIRST AND SECOND STAGES OF SAID INCOMING REGISTER MEANS TO SAID SECOND AND FIRST STAGES, RESPECTIVELY, OF SAID OUTGOING REGISTER MEANS TO ENABLE TWO-WAY DATA TRANSMISSION BETWEEN SAID FIRST AND SECOND STATIONS; AND ANCILLARY REGISTER MEANS AT SAID CENTRAL OFFICE HAVING STAGES PAIRED WITH THOSE OF SAID INCOMING AND OUTGOING REGISTER MEANS FOR THE STORAGE OF SERVICE INFORMATION PERTAINING TO A CONNECTION BETWEEN SAID FIRST AND SECOND STATIONS; SAID FIRST AND SECOND STATIONS BEING PROVIDED WITH VOICECOMMUNICATION EQUIPMENT AND WITH SWITCHOVER MEANS FOR TEMPORARILY CONNECTING SAID VOICE-COMMUNICATION EQUIPMENT TO THE SIGNAL PATHS THEREOF IN LIEU OF SAID DATA-COMMUNICATION EQUIPMENT, SAID CENTRAL OFFICE INCLUDING LINE LINKS TEMPORARILY ALLOCABLE BY SAID PROGRAMMING MEANS TO SAID STATIONS, SAID LINE LINKS BEING RESPECTIVELY ASSIGNED TO SAID CHANNELS AND COUPLED TO SAID PROGRAMMING MEANS FOR ENGAGING THE REGISTER STAGES ASSOCIATED WITH THE ASSIGNED CHANNEL UPON TEMPORARY ALLOCATION OF A LINE LINK BY SAID PROGRAMMING MEANS TO A STATION, EACH LINE LINK BEING PROVIDED WITH MONITORING MEANS FOR DISCRIMINATING BETWEEN A VOICE-COMMUNICATION STATE AND A DATACOMMUNICATION STATE ON A SIGNAL PATH TEMPORARILY CONNECTED THERETO AND FOR COMMANDING SAID PROGRAMMING MEANS TO KEEP SAID SERVICE INFORMATION STORED IN SAID ANCILLARY REGISTER MEANS UPON A SWITCHOVER FROM SAID DATA-COMMUNICATION STATE TO SAID VOICE-COMMUNICATION STATE FOR POSSIBLE RESUMPTION OF DATA TRANSMISSION BETWEEN SAID FIRST AND SECOND STATIONS.