Optimal design and evaluation of survivable WDM transport networks

摘要

This paper proposes an optimal design scheme for survivablenwavelength-division multiplexing (WDM) transport networks in which fastnrestoration can be achieved by using predetermined restoration pathsnthat are independent of failure locations and which have one to onencorrespondence with working paths. Integer programming-based designnproblems are formulated to optimally determine working and theirncorresponding restoration paths, the number of fibers in each span, andnthe number of optical cross connects (OXCs) in each node. In thesenoptimization problems, total facility cost, which includes not onlyntransmission cost but also cross connection, is minimized. This designnscheme can handle the dedicated/shared allocation of spare resources andnseveral parameters, such as the maximum available number of wavelengthsnper fiber Ω, the matrix size of each OXC, and cross-connection tontransmission cost-coefficient ratio Γ. Total fiber length, thentotal number of OXCs, etc., are evaluated from obtained design resultsnfor these options and parameters. Numerical examples show that thendependency of total fiber length and the total number of OXCs on Γnis relatively small, and cross-connection to transmission cost ratiosn(Γ times the total number of OXCs divided by total fiber length)nin the dedicated and shared cases are almost the same for eachncombination of Γ and Ω