Optical fiber bandwidth limiting method

Abstract

A fiber optic telephone system is described in which a plurality of subscribers with different bandwidth subscriptions are each connected to the system by an optical fiber subscriber connection. Use of the subscriber connection beyond the subscription bandwidth is prevented by the installation of a bandwidth limiting device having a maximum transmitted bandwidth capacity above that of the subscription bandwidth but below that of the total bandwidth capacity of the subscriber connection.

What is claimed is: 
     
       1. In a fiber optic communication system wherein a plurality of subscribers are connected to a central office by optical fiber connections over each of which information is transmitted pursuant to a subscription agreement designating a predetermined subscription bandwidth for each said optical fiber connection, each of said optical fiber connections providing an information path extending from said central office to a respective subscriber premise, the improvement comprising means for regulating subscriber usage of each of said optical fiber connections comprising a plurality of bandwidth limiting devices, each connected in series in a respective one of said optical fiber connections in said information path, each said bandwidth limiting device including means for introducing .[.material.]. dispersion to the associated one of said optical fiber connections beyond that inherently present in said connection, said material dispersion being selected to limit the bandwidth of the associated one of said optical fiber connections to the said subscription bandwidth designated in the said subscription agreement associated with said optical fiber connection by limiting the frequency which can be transmitted on the associated optical fiber connection to a maximum frequency which is greater than or equal to the subscription bandwidth for said subscriber optical fiber connection but below that of the total capacity of said subscriber optical fiber connection. 
     
     
       2. In the administration of a fiber optical communication system wherein a plurality of subscribers are connected to a central office by optical fiber connections over each of which information is transmitted pursuant to a subscription agreement designating a predetermined subscription bandwidth for each said optical fiber connection, each of said optical fiber connections providing an information path extending from the central office to a respective subscriber premise, a method of preventing use of subscriber connection beyond the subscription bandwidth, comprising, installing means for regulating subscriber usage of each of said connections, said regulating means comprising a plurality of bandwidth limiting devices, each connected in series in a respective one of said optical fiber connections in said information path, each said bandwidth limiting device including means for introducing .[.material.]. dispersion to the associated optical fiber connection beyond that inherently present, said material dispersion being selected to limit the bandwidth of the associated optical fiber connection to the said subscription bandwidth designated in the said subscription agreement associated with said optical fiber connection by limiting the frequency which can be transmitted on the said associated optical fiber connection to a maximum frequency which is greater than or equal to the subscription bandwidth for that subscriber optical fiber connection but below that of the total capacity of that subscriber optical fiber connection.