WAVELENGTH ASSIGNMENT IN ALL-OPTICAL WDM NETWORKS WITH RING TOPOLOGY
Guo Jun LI(1),Shao Qiang ZHANF(1),OUSMANE SAMAKE(1),Guang Ting CHEN(2)
(1)School of Mathematics and Systems Science, Shandong University, Ji'nan 250100,P.R.China;(2)School of Science and Arts,Hangzhou University of Electronic Science and Technology，Hangzhou 310012,P.R.China
The problem we consider arises in an all-optical communications network with wavelength division multiplexing (WDM) configured as a ring. Given a set of paths (requests) over a ring, wavelengths must be assigned to the corresponding paths such that paths that use the same link are assignde different wanelengths. The goal is to minimize the number of required wanelengths.In this article,we design an approximation algorithm that assure the number of wabelengths assignde into the set of paths is no more than 1.5ω,where ω is the cardinality of the maximum ser of pairwise intersecting paths.Since ωis a lower bound of the minimun possible number of wavelengths for the set of paths,the algorithm guarantees that the performance ratio is no more than 1.5.