The use of fibre optic transmission is now commonplace in telecommunications, data communications and broadcast quality television signal applications.The need for the installation of extensive CCTV systems to combat crime, vandalism and terrorism. Conventionally cameras are linked to monitors over copper cable links using the lowest cost components available. As system size has increased the distance between cameras and monitors has also increased resulting in an unacceptable degradation of received video signal quality. i.e. received picture quality, for link distances over 100 – 150 m. This has meant that the use of optical fibre transmission has had to be considered even in this most cost conscious of applications.
In these sections we will attempt to de-mystify fibre optic transmission as applied to CCTV system use. We will start by outlining why fibre optics should be used, go on to consider the basic elements of a fibre optic converter system and installation practice and finally outline the technology to extend CCTV systems from essentially local installations to extensive, distributed multi-channel signal transmission systems.In comparison fiber attenuation is between 0.3 and 3 dB/km meaning that fiber optic transmitter distances of 60 km can be achieved, depending on the precise details of the application. In addition this low fibre signal attenuation is achieved over a very wide signal frequency range so that optical fiber can be used for the transmission of multiple video signals over long distances.