Link-Rate Assignment in a WDM Optical Mesh Network with Differential Link Capacities: A Network-Engineering Approach

Wavelength-division multiplexing (WDM) optical networks are characterized by maturity, high-capacity, agility, flexibility, and cost-efficiency. Today, optical transmission rates are increasing from 10 Gbit/s to 100 Gbit/s which increases the network´s flexibility for capacity provisioning. We study the problem of dimensioning optical WDM networks under traffic growth. Particularly, we study link-rate assignment and capacity expansion (namely network engineering). Our study shows that, with careful link-rate assignment, the network´s traffic can be satisfied and any traffic growth can be accommodated using the network´s current resources with some additional resources so that cost is minimized. Our study also shows that, by careful selection, only a few links with high rates can meet the capacity needs of the network and that any additional high-rate links (extra cost) may not significantly improve the network´s efficiency.