The communication facilities provided on the Railways are broadly categorized in to three of applications viz Train operation, OFC for long haul & short haul communication & Mobile Train Raido Communication .
FIBRE OPTIC TRANSMISSION
Optical fibre Cable consists of a core and a cladding layer, selected for total internal reflection due to the difference in the refractive index between the two. In practical fibers, the cladding is usually coated with a layer of acrylate polymer or polyimide. This coating protects the fiber from damage but does not contribute to its optical waveguide properties. Individual coated fibers (or fibers formed into ribbons or bundles) then have a tough resin buffer layer and/or core tube(s) extruded around them to form the cable core. Several layers of protective sheathing, depending on the application, are added to form the cable.
Rigid fiber assemblies sometimes put light-absorbing (“dark”) glass between the fibers, to prevent light that leaks out of one fiber from entering another. This reduces cross-talk between the fibers, or reduces flare in fiber bundle imaging applications. Provides a common transmission backbone for the subsystems . FOTS provides status monitoring, configuration , analysis and control of various network elements.