Abstract: A service integrated transmission system for transmitting, over a light transmission path, digital signals having a transmission band whose upper limit frequency corresponds to the maximum bit rate of the signals to be transmitted, the transmission being effected by simultaneously transmitting, over the transmission path, digital signals having a high bit rate only in an upper part of the transmission band and digital signals having a low bit rate only in a lower part of the transmission band. The system includes a transmitter at one end of the path which separately multiplexes low bit rate signals into a narrowband signal and high bit rate signals into a broadband signal, combines those multiplexed signals, and modulates a light source with the combined signal. A receiver at the other end of the path converts the modulated light signal into a demodulated electrical signal, separates the two multiplexed signals, and then demultiplexes each of the latter signals.

Abstract: In a service integrated multiplex signal transmission system for transmitting narrowband and broadband signals between a central exchange terminal and a subscriber terminal, which system includes a light conductor 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 light conductor path, and a receiver device at the other terminal composed of demultiplexers connected to the light conducting 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 being normally supplied with operating power by local utility mains, and including a charge accumulator for supplying operating power independently of the local mains, connected for supplying such power to the device