Abstract: A service integrated, time multiplex digital signal transmission system for transmitting narrowband and broadband signals between a central exchange terminal and a subscriber terminal, which system includes a optical fiber waveguide path connected between the terminals, a transmitter device at one terminal composed of sources of such narrowband and broadband signals and multiplexers connected for combining the signals provided by the sources into a multiplex signal and for supplying such multiplex signal to the optical fiber waveguide path, and a receiver device at the other terminal composed of demultiplexers connected to the optical fiber waveguide path for receiving multiplex signals from that path and separating the received multiplex signals into narrowband signals and broadband signals. The device at the subscriber terminal is normally supplied with operating power by local utility mains.

Abstract: A digital time multiplex communications system for transmission of a time multiplex signal containing the signal elements of a synchronization channel and of a plurality of communications channels. The receiver includes a member for separating the synchronization channel signal element from the communications channel signal elements of each frame. An externally triggerable sawtooth voltage generator connected to the separating member generates a sawtooth voltage sweep in response to the appearance of each synchronization channel signal element. A plurality of comparison stages each associated with a respective communications channel and connected to receive the sawtooth voltage and to produce an output signal when the sawtooth voltage reaches a respective value which differs by a fixed amount from one stage to the next such that the output signal from each stage occurs at a time corresponding to the appearance of a signal element of its associated communications channel.