Multiperiod Planning with Controlled Shortest Path Routing

For simplified network operations, demands are often routed on shortest paths, e.g., with physical length as metric. We propose a new controlled shortest path routing concept for multiperiod planned networks, formulated as optimization model. This routing concept minimizes the network costs (capital expenditures) under the constraint of using shortest path routing within the lit fiber network. Within a single optimization step, fibers on candidate topology edges are chosen to become lit, constituting a (lit) fiber network, such that cost-optimal results are obtained under shortest path routing within this selected fiber network. In case studies our new routing and dimensioning approach is compared with shortest path routing in the candidate topology and general cost-optimal routing. For lightly to medium loaded networks, case studies show that controlled shortest path routing can achieve significantly lower cost results than shortest path routing, while being comparable in cost to cost-optimal routing.