Packet contention is a very important issue in optical packet-switched networks. This paper analyzes asynchronous optical packet switches when wavelength conversion is used as contention resolution mechanism. A Wavelength converter can convert one wavelength to another and consequently improve the network performance. In practical systems, a wavelength converter normally presents limited range conversion capability. In this paper we propose a Markov model that enables the calculation of packet blocking probability for asynchronous optical packet switches equipped with single per channel limited-range wavelength converters. The analytical model is based on an infinitely fine input granularity assumption and it is shown to present a good approximation with simulation results. © 2005 IEEE. 349353Gross, D., Harris, C.M., Fundamentals of Queueing Theory, , A Wiley-Interscience Publication, 3rd editionXu, L., Perros, H.G., Rouskas, G., Techniques for optical packet switching and optical burst switching (2001) IEEE Communications Magazine, , JanuaryPapadimitriou, G.I., Papazoglou, C., Pomportsis, A.S., Optical switching: Switch fabrics, techniques and architectures (2003) Journal of Lightwave Technology, 21 (2), pp. 384-405. , FebruaryHunter, D.K., Chia, M.C., Andonovic, I., Buffering in optical packet switches (1998) Journal of Lightwave Technology, 16, pp. 2081-2094. , DecemberAlmeida Jr., R.C., Pelegrini, J.U., Waldman, H., Delay-line buffer modeling for asynchronous optical networks (2003) Proceedings of SPIE Opticomm'03, , Dallas, TX, USAOctoberCastañón, G., Design-dimensioning model for transparent WDM packet-switched irregular networks (2002) Journal of Lightwave Technology, 20 (1). , JanuaryFayoumi, A.G., Jayasumanda, A., Sauer, J., Performance of multihop networks using optical buffering and deflection routing (2000) IEEE Conference on Local Computer Networks, , Tampa, FL, USA, NovemberDanielsen, S.L., Mikkelsen, B., Joergensen, C., Durhuus, T., Stubkjaer, K.E., WDM packet switch architectures and analysis of the influence of tunable wavelength converters on the performance (1997) Journal of Lightwave Technology, 15, pp. 219-226. , FebruaryDanielsen, S.L., Joergensen, C., Mikkelsen, B., Stubkjaer, K.E., Analyses of a WDM packet switch with improved performance under bursty traffic conditions due to tunable wavelength converters (1998) Journal of Lightwave Technology, 16 (5), pp. 729-735. , MayZhang, Z., Yang, Y., Performance modeling of bufferless WDM packet switching networks with wavelength conversion (2003) IEEE Globecom, , San Francisco, CA, USA, DecemberShen, G., Bose, S.K., Cheng, T.H., Lu, C., Chai, T.Y., Performance study on a WDM packet switch with limited-range wavelength converters (2001) IEEE Communications Letters, 5 (10). , OctoberEramo, V., Listanti, M., Di Donato, M., Performance evaluation of a bufferless optical packet switch with limited-range wavelength converters (2004) IEEE Photonics Technology Letters, 16 (2). , FebruaryAlmeida Jr., R.C., Pelegrini, J.U., Waldman, H., Deflection Routing and Wavelength Conversion in Asynchronous Optical Packet Networks (2004) XXI Simpósio Brasileiro de Telecomunicações - SBrT'04, Belém, Pará, Brazil, September