Dynamic load balancing in WDM packet networks with and without wavelength constraints

We develop load balancing algorithms for WDM-based packet networks where th e average traffic between nodes is dynamically changing. In WDM-based packe t networks, routers are connected to each other using wavelengths (lightpat hs) to form a logical network topology. The logical topology may be reconfi gured by rearranging the lightpaths connecting the routers. Our algorithms reconfigure the logical topology to minimize the maximum link load. In this paper, we develop iterative reconfiguration algorithms for load bal ancing that track rapid changes in the traffic pattern. At each reconfigura tion step, our algorithms make only a small change to the network topology, hence minimizing the disruption to the network. We study the performance o f our algorithms under several dynamic traffic scenarios and show that our algorithms perform near optimally. We further show that these large reconfi guration gains are achievable in systems with a limited number of wavelengt hs.