A circuit rerouting algorithm for all-optical wide-area networks

Rerouting for a circuit-switched wavelength-division-multiplexed all-optical network is considered in the paper. Due to the wavelength continuity constraint, a new connection may be blocked even if bandwidth is available between the origin and the destination. Rerouting can make the available bandwidth wavelength-continuous by changing the routes of certain existing connections to accommodate the new connection. To avoid disruptions of existing connections, move-to-vacant wavelength-retuning (MTV WR) is proposed as the basic operation of circuit migration, in which a circuit is moved to a vacant wavelength on the same path, and the parallel MTV WR rerouting scheme is considered to reroute multiple circuits on disjoint sets of links. The authors design the optimal algorithm which minimizes the weighted number of rerouted circuits with the parallel MTV WR rerouting scheme. Numerical results using simulation show that rerouting can effectively reduce the blocking probability due to the wavelength continuity constraint while minimizing the incurred disruptions