Benefits of partial reconfigurability in circuit-switched WDM networks

We describe and study partially reconfigurable circuit-switched networks. These are dynamic networks in which partial, but not complete, flexibility of resource assignment is retained during the lifetime of a connection. In particular we analyse two examples of partially reconfigurable WDM networks with flexibility of wavelength assignment. In the first example, each connection in the network requires a main lightpath (whose wavelength must remain fixed) and a standby lightpath (whose wavelength may change). In the second example, the network contains two classes of connections with different service levels, one class reconfigurable and the other not. We propose two contrasting reconfiguration algorithms, and demonstrate that even a small amount of reconfigurability can yield significant performance gains, while a large amount of reconfigurability yields almost all the performance gain that would be attained by introducing complete wavelength conversion to the network.