Transparent optical network design for standard single-mode infrastructure

Design, control and management of all-optical transparent islands based on fibers, optical amplifiers and transparent Optical Cross Connects (OXC) have to deal with a vast number of issues such as network topology, routing, protection, and restoration schemes. However, since in such a transparent network light-paths generally have to transit through several fiber sections, amplifiers, and OXCs, all of which add noise and degrade the signal performance, optical layer network protocols have to be aware of the end-to-end signal quality for each specific light-path. This information should be obtained without burdening these protocols with details of the physical layer. In this paper we propose a simplified network design approach based on normalized optical transmission sections where the physical links are built from a cascade of identical basic blocks. For an upper layer protocol only the number of traversed blocks has to be monitored for estimating signal quality. Using numerical simulations the maximum number of cascaded building blocks for 10 Gbit/s RZ modulation format for different basic building block-configurations is investigated and compared with the performance of NRZ based systems under similar conditions. It is shown that robust transparent islands of about 1600 km maximum link length without 3R regeneration are feasible for both modulation formats using the concept of normalized sections.