Routing and spectrum allocation in flexi-grid optical networks

We compare three lightpath routing and spectrum allocation algorithms for the flexi-grid optical transport networks. The three algorithms include shortest path first algorithm, grid-plane-based first-fit algorithm, and grid-plane-based exhaustive algorithm. We evaluate the performance of these algorithms through simulations. It is found that the grid-plane-based algorithms can achieve much better blocking performance than that of the shortest routing algorithm and there is tradeoff between lightpath blocking performance and computation time for the three algorithms.