WDM SURVIVABLE NETWORK REQUIREMENTS AGAINST TRANSMISSION LIMITATIONS IN THE PAN-EUROPEAN CORE NETWORK

Network features against physical limitations: To compare with limitat ions caused by the fibre, a number of channels against distance curve was drawn. For each number of channels, the longest path element suppo rting this number is deduced from the routing tables, which gives a po int of the curve. As shown in Fig. 2, we obtain several curves dependi ng on the number of transit nodes in the path element. The feasability of optical transmission may be estimated by comparing these routing f eatures with physical limitations. Stimulated Raman scattering crossta lk and threshold [6] were estimated with reasonable physical parameter s for a IdB signal power penalty. Degradation caused by other nonlinea rities can be minimised by clever system design and were not considere d.