Number of wavelengths required for constructing large‐scale optical path networks

Abstract

Photonic networks that exploit the abundant optical bandwidth capability are needed to realize a truly effective B-ISDN. We have proposed two optical path schemes, the wavelength path (WP) scheme and the virtual wavelength path (W) scheme, wherein wavelength division multiplexing/frequency division multiplexing (WDM/FDM) technologies are employed in the path layer of the transport networks. Although wavelengths are precious resources in photonic networks, the number of wavelengths required for any network has never been evaluated because of the NPcompleteness of the wavelength assignment problem. In this paper, we propose heuristic optical path accommodation design algorithms that can minimize the wavelength requirements in the network. We also evaluate the wavelength requirements for large-scale and irregularly structured physical network topologies utilizing the proposed algorithms. Accordingly, we elucidate, for the first time, that the wavelength requirements for the WP and VWP schemes are almost the same regardless of physical network topologies and path demand distribution patterns.

Survivable routing in IP-over-WDM networks: An efficient and scalable local search algorithm

“…The capacity iterations have some similarities with a local search for routing and wavelength assignment described by Nagatsu et Al. in [10].…”

Solving the routing and wavelength assignment problem with a multilevel distributed memetic algorithm

“…Common approaches to assign wavelengths to given paths are a bin packing inspired heuristic [8,12,37,47] and a graph coloring (GC) method either in a basic variant [4,6,24] or in a generalized form [14,27]. The wavelength assignment problem is equivalent to the graph coloring problem.…”

“…Table 1 gives an overview on the used methods, which will be presented in detail below. For the routing subproblem the most popular approaches are based on shortest path (SP) algorithms [6,8,24,27,37].…”

Performance of WDM transport networks

“…Sato et al [40]- [42] used the longer-paths-first policy to accommodate paths. The difference between the number of wavelengths with and without wavelength conversion is found to be less than 4% for various traffic volumes at a 50-node mesh network.…”