Packet loss bounds for asynchronous bufferless optical packet switches with limited range wavelength converters

This paper evaluates the performance of an asynchronous optical packet switch (OPS) equipped with limited range wavelength converters (LRWCs), in terms of packet loss ratio (PLR), when a circular-type wavelength conversion is adopted. Two separate Markov models are proposed to provide the analytical upper and lower bounds values of the PLR. The corresponding closed form expressions are given. We also build a discrete event simulator which introduces two realistic-to-implement conversion policies (closest conversion, random conversion) for the arriving packets. Results show that the proposed models give the absolute PLR bounds values for the studied OPS node. In addition, the paper gives clear guidelines for the applicability of the present models according to the normalized system load, the conversion range of the used LRWCs, and the employed conversion policy.