OPTIMIZATION OF ROUTING AND WAVELENGTH ASSIGNMENT IN PASSIVE OPTICAL NETWORKS

Abstract

This paper presents the implementation of a metaheuristic algorithm on optical network to fix Routing and Wavelength
Assignment (RWA) problem.RWA is one of the important optimization problems in optical networks. RWA problem are of two
types, static and dynamic. In static RWA the set of connections is known in advance where as in dynamic RWA connection
request arrive sequentially. Here we examine the dynamic routing and wavelength assignment problem. The goal is to minimize
the number of wavelengths and blocking probability. Evolutionary programming algorithms are used to optimize the routing
and wavelength assignment. The RWA problem can be fixed by number of algorithms like GA, ACO etc. In this paper, Shuffled
Frog Leaping Algorithm (SFLA) has been implemented in optical networks to fix the RWA problem.. Cost, number of
wavelengths, hop count and blocking probability are the optimization parameters. In WDM network, for the given set of
connection requests, routing and wavelength assignment problem involves the task of establishing lightpaths (routing) and
assigning a wavelength to each connection request. The problem is analyzed for different wavelength assignment methods such
as first fit, random, round robin and wavelength ordering. Fitness function is calculated in terms of cost, number of wavelengths,
hop count and setup time. SFLA algorithm produce less blocking probability, less cost and less computational complexity than
existing methods.