Node arrangement optimisation in linear multihop lightwave networks

Virtual topologies of WDM-based multihop networks can be arranged by assigning wavelengths to tunable transceivers of nodes. An optimal node arrangement problem in multihop lightwave networks with linearly virtual topologies is considered. For a given traffic matrix, this problem is to arrange node locations to adapt traffic patterns and optimise network performance. However, the problem of node arrangement for constructing optimised linear virtual topologies has been proved as NP-complete. Two lower bounds are proposed for this problem according to the traffic-weighted mean hop distance and the maximum link flow, respectively. An efficient node arrangement algorithm, called k-ENA, is also proposed. The performance of the k-ENA algorithm is compared with the best algorithms in previous work. Simulation results indicate that the k-ENA algorithm generally yields the best solutions