Transparent optical networking-an European operator view

From a system-theory point of view a transparent optical path in optical networks is defined by a path, which only passes 1-R regenerators, fibres or optical systems that can be characterised by a linear optical transfer function. Theoretically a transparent optical path allows the transmission of optical signals independently from data rate and modulation format. Client layer protocol transparency is a general assumption of the OSI communication model as well as of the layer transport network architecture defined in ITU-T G.805. A server layer network has to transport a client signal in a way that the client signal itself is not affected by the transport process.