Abstract: An integrated telephone transmission and switching system operating in a multiframe format where each frame consists of a plurality of time slots and includes a base switch connected to a plurality of multitime slots data buses where the base switch operates to switch encoded data between any specified time slots on any of the buses. A subscriber switch is connected between a plurality of subscriber lines and to a pair of multitime-slot data buses and operates to connect and concentrate the local subscriber lines to the specified time slots on the pair of data buses, thereby enabling connections between a local subscriber line and any other subscriber line connected to the system.

Abstract: A subscriber termnal for use in a TDM telephone system operating in a multiframe format where each time frame consists of a plurality of time slots, said system including a base switch connected to a plurality of multitime slot data buses for switching encoded data between specified ones of the time slots. A subscriber switch is connected to a plurality of local subscriber lines and to a pair of the data buses for switching encoded data between the subscriber lines and specified time slots on the pair of data buses. The subscriber switch includes a number of subscriber terminals where each terminal is connected to some of the subscriber lines and includes a pair of subscriber switch controllers for controlling the switching of data between the subscriber lines and the pair of buses.

Abstract: A multifrequency sender/receiver in a telephone system operating in time frames each including a plurality of time slots, including a sender for generating and connecting selected multifrequency tone signals in pulse code modulated format to a first group of the time slots. The receiver is responsive to the presence of a multifrequency tone in a second group of the time slots and provides a data signal representative of the tone signal present. Control means specify the selected tone signals to be sent in the first group of time slots.