Abstract: Data transmission in, for instance, a PCM system, is effected by translation of the binary codes into ternary combinations such that to each binary code there is provided n ternary codes with the choice of the ternary code sent being dependent on secondary intelligence, such as signalling information and/or synchronization information, to be sent. In the example described a binary bit stream is split into three bit blocks each of which is converted into a three bit ternary code.

Abstract: Apparatus within a time division multiplex telecommunications system for terminating local traffic at a local distributing center and eliminating the need for use of channels to the switching center. The system employs time slots for calls to the switching center and other time slots for local calls. Digits representing the called line are stored in a register at the calling station. The register is interrogated after sufficient digits have been stored to inidicate the destination as local or switching center. When a local call is recognized, a bistable in the local distributing center is set. When the end of dialing signal is received, a code is generated to release the channel connection to the main exchange and to complete the call locally over time slots dedicated to serving local calls.

Abstract: A time-division multiplex (TDM) control system for controlling a plurality of devices from a central point includes a transmitter whose output is coupled over a common path to a plurality of receivers respectively located adjacent to the devices. The transmitter provides a repetitive cycle of a predetermined number of time slots during which a control signal is provided at any one or all of the time slots. Each receiver is assigned a given time slot corresponding to one of the time slots in the repetitive cycle of the transmitter, and each receiver is responsive to the control signal during its given time slot. Each receiver is operative to control one of the devices in response to the control signal.

Abstract: An automatic telecommunication switching system is disclosed for switching TDM speech signals and data signals between calling and called parties. The system includes auxiliary circuits. Such circuits may include a monitor or comparator to detect the presence of a particular code. They may include a code converter for receiving a code of one variety and transmitting one of another variety or for changing the speed between reception and transmission.