A Two Levels Architecture For Bufferless WDM Optical Packet Switches

The objective of this study is to propose a new bufferless optical packet switching architecture in which thew converters, needed to solve output packet contentions, are used in two levels. The architecture is equipped with limited-range wavelength converters (LRWCs) at the first level and with shared and full-range wavelength converters (FRWCs) at the second level. In a WDM all optical network, in the absence of wavelength conversion ability, the signal is required to be on the same wavelength from hop to hop, which is referred to as the wavelength continuity constraint Studies show that network performance is greatly improved by using wavelength converters [1]. If a wavelength converter can convert a wavelength to any other wavelength in the optical system, it is called full range wavelength converter. However, this type of wavelength conversion is quite difficult and expensive to implement due to technological limitations [2]. In proposed architecture, limited numbers of FRWCs are shared at the output of optical packet switch, to make that more cost effective. Although a few number of FRWCs are used, it causes reduction of packet loss probability about 40%.