Optimal lightpath routing and rerouting in WDM networks

The high throughput provided by WDM technology in fiber optic networks and the emergence of high speed all-optical wavelength converters have attracted extensive research on lightpath routing in WDM networks. Given a connection request, it is desirable to find a minimum cost lightpath or semi-lightpath to establish the connection without interrupting any existing connections. When a connection cannot be established without rerouting, one would like to establish a connection after rerouting a minimum number of existing lightpaths. In this paper, we present an efficient algorithm for computing a minimum cost route among routes requiring minimum cost reroutings. Our results provide either improvements or generalizations of several recent results in lightpath routing/rerouting