Distributed control system for multiple random access to the transmission line of a local network for speech and data

Abstract From the Canadian patent

The system allows packet synchronous speech communications without requiring any centralized device synchronizing all the network stations. Asynchronous packet, switched data traffic accesses the transmission line by means of a distributed contention algorithm such as, CSMA-CD. The access to the line for a speech communication is obtained by the same contention technique used for data transmissions but, once a station has accessed the line for a speech communication, this communication is alloted a synchronous channel which is maintained for the whole communication duration. To obtain that each, station organizes its activity into frames having a, duration equal to the speech packetization …