| Abstract: | Since 1986, the first operating video communications systems developed by ALCATEL, have been commercially opened in the cities of Rennes, Saint-Cloud, Mantes and Toulon; other plants are under installation in the cities of Evry, Marseille, Massy, Gennevilliers, Lille and Montpellier. The basic infrastructures already installed permit the connection of several tens of thousands of households. Compared with conventional coaxial system, the ALCATEL video communications system presents the following main advantages: - (a) More efficient operating facilities for audiovisual services offering built-in access control functions, without any additional descrambling terminal on the user's premises, allowing easy introduction of pay-per-view programming, and providing advertising people with adequate audience measurements.
- (b) Flexible and continuous implementation of additional telecommunication services such as telephony, videotex, home security, bidirectional data transmission and professional specialized applications.
Those advantages are a direct consequence of the switched-star network structure, based on fibre-optic technologies. After a brief overview of the architecture, the paper will present design principles and the main technical choices related to the ALCATEL system. The second part of the paper will describe the different subsystems constituting the switched-star network such as the subscriber subsystem and the operating and maintenance organization. Lastly, different evolving schemes for future introduction of narrowband and the broadband telecommunication services will be proposed. |
