Review of Physical Layer Related Issues in WDM Networks: Part-II

Abstract

In the first part of this paper [1] we reviewed the non-linear effects present in the optical fiber, different types of optical amplifiers available, their limitations and the choice of amplifier for use in long haul WDM systems. It was shown that the number of amplifiers deployed is limited by the noise generated by the amplifiers. Also, the algorithms used for optimal placement of in-line amplifier had been discussed. In the design of the long haul WDM system, wavelength converters play a major role in reducing the blocking probability of the optical network. In this second and concluding part, we review the architecture of wavelength converters. We discuss various analytical models for evaluating blocking probabilities under different conditions and the routing and wavelength assignment schemes. We conclude with the summary of the various algorithms for optimal placement of wavelength converters.