Optical communication system for cable-television signals and for subscriber-assigned signals

US5748348A · kind A · utility

Assignee

• Alcatel N.V. · NL

Inventors

• Rolf Heidemann · Zöblitz, DE
• Gustav Veith · Hemmingen, DE
• Jurgen Otterbach · Stuttgart, DE

Key dates

• Filing date: Nov 6, 1995
• Grant date: May 5, 1998
• Expiry date: Nov 6, 2015

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04N7/22
• WIPO field: Audio-visual technology
• WIPO sector: Electrical engineering

Abstract

In an optical communication system in which cable-television signals and subscriber-assigned tele-communication signals are transmitted over a passive optical network (4, 5) to at least one optical network termination (6), each optical network termination (6) requires two optical-to-electrical transducers. An optical network termination (6) is disclosed which requires only one optical-to-electrical transducer (24). The system has two transmitting devices (1, 2) which each transmit a respective optical signal (O.sub.TV, O.sub.D). In the second transmitting device (2), a second electric signal (S.sub.D), whose energy occupies a second frequency band (FB2), is processed in such a way that the energy is concentrated in a subband lying outside the first frequency band (FB1) of a first electric signal (S.sub.TV). The optical-to-electrical transducer (24) in the optical network termination (6) converts the received optical signals (O.sub.TV, O.sub.D) to an electric multiplex signal (E.sub.MUX), from which the two electric signals (S.sub.TV, S.sub.D) are recovered.