International Journal of Electronic and Electrical Engineering. ISSN 0974-2174 Volume 4, Number 1 (2011), pp.49-59 © International Research Publication House http://www.irphouse.com Reconfiguration with Prioritize Lightpath Requests in WDM Optical Network Manish Shrivastava and Aditya Goel Department of Electronics & Communication, MANIT (Deemed University), Bhopal, India. E-mail: maneesh.shreevastava@yahoo.com, adityagoel2@radiffmail.com Abstract Reconfiguration of a wavelength routed optical network with the use of priority scheduling algorithm to priotoriza lightpath request with the aim to utilizing or exhausting the resources. Preference has given to heavily loaded in establishing lightpaths between node pairs having large traffic and low preference to lightly loaded lightpaths. Applications such as grid computing, e-science, three dimensional (3D) teleconferencing consume large bandwidth and require that the lightpaths are available for the entire session although there might be intermittent periods with less traffic between the nodes. Hence, the reconfiguration process must not tear down these lightpaths. We propose to use a priority scheduling algorithm in which lightpaths requests are prioritize according to the class of traffic, and the lightpaths of high priority applications are entertained first by the reconfiguration process. For low priority applications such as email, the lightpath requests will be processed latter or the data can be transmitted by multihopping. Designing of logical topology is basically a set of connection requests to be processed. In this paper, we have given a solution through a program (based on priority scheduling algorithm) in MATLAB7.9. This algorithm takes low and high priority lightpath requests, first occupy all the connections with high priority requests and if still there is a room for few connections let it be filled with low priority data. Further we have performed simulation and obtained the simulated output through MATPLAN WDM5. Keywords: Virtual topology, Reconfiguration, Prioritize data, Lightpaths, Optical Network and Logical topology. Introduction Phonetic networks are currently widely employed to support a variety of