Optical communications system for the subscriber area with optical amplifiers

US5337175A · kind A · utility

Assignee

• Alcatel N.V. · NL

Inventors

• Horst Ohnsorge · Freiberg, DE
• Adolf Weygang · Stuttgart, DE
• Rolf Heidemann · Zöblitz, DE

Key dates

• Filing date: Feb 11, 1992
• Grant date: Aug 9, 1994
• Expiry date: Feb 11, 2012

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04J14/0298
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

Optical communications system for the subscriber area with optical amplifiers. The system according to the invention is used to distribute information signals, particularly telephone signals, from a center to a plurality of subscribers and to make possible a bidirectional transmission of telephone and data signals between the center and the subscribers. According to the invention, the network used for this purpose is a multistar fiber-optic network in which fiber-optic amplifiers (10, 11) are present between successive branch points. The information signals to be distributed are transmitted via the fiber-optic network with a first wavelength (.lambda..sub.1) to the subscribers, and the subscriber-specific information signals to be transmitted from the center (1) to the subscribers (T.sub.i) are converted by frequency modulation to a different frequency band (FB.sub.2) than the distribution signals (by frequency modulation) and transmitted to the subscribers at the same wavelength as the distribution signals, and the subscriber-specific signals to be transmitted from the subscribers (T.sub.i) to the center (1) are converted by frequency modulation to another frequency band (FB.sub.3…