This paper proposes a new approach to designing alternate routing algorithms for all-optical wavelength-division multiplexing networks in order to reduce the connection blocking probability. The key idea is to try to route traffic in approximately the optimal way of splitting the traffic among the multiple routing paths between each source-destination pair. The optimal way of splitting the traffic among the multiple routing paths between each source–destination pair is obtained by solving a nonlinear multicommodity flow optimization problem. Two alternate routing algorithms, namely, traffic intensity based fixed-alternate routing algorithm and traffic intensity based dynamic-alternate routing algorithm, are proposed based on this approach. Simulations are performed to study the performances of the proposed alternate routing algorithms. Our simulation results show that the alternate routing algorithms designed according to the optimal way of splitting the traffic can effectively reduce the connection blocking probability.
IEEE/OSA Journal of lightwave technology,26(22),p.3604–3616