The
acronym PCS, in
networking terms, refers to standard plastic-clad
silica. Silica, also known by the term
glass, is the optical core of a
fiber-optic cable. The cladding applied to the outside of the fiber is made of plastic, which has a lower
angle of refraction and keeps the optical signal inside the glass
fiber.
PCS, if it is not damaged, has an excellent range and a wide bandwidth. It is immune to electro-magnetic interference.