Gain Based Quality Computation in WDM Routing

Abstract

In case of WDM networks, normally optical fibre cables are being used to transmit signal in the form of a light pulse within the transmitter and receiver. These systems possess the power to transmit more than one signal simultaneously. But we know light signal degrades in intensity when it travels through a long distance within the fibre. That is why it is essential to amplify the light signals together at a time after travelling a certain distance to regain the original one. In that case, Optical amplifiers are being used in order to amplify the light signals. There are various types of optical amplifiers exist. They are:–EDFA and Raman amplifier. In this thesis, analysis of a WDM network is carried out taking into account EDF amplification with the help of opti system software. So to reduce the attenuation losses after a long distance transmission, optical amplifiers are used. Here the gain and noise figure of the EDFA with different pumping techniques is analysed value. After that, emphasis has been given on Raman amplifier and one mathematical model has been taken into consideration to calculate the gain. After that one WDM network having 10 nodes connected to each other bidirectional through Raman amplifier is taken in to account. Using that mathematical model, gain has been calculated for each path .for a given source and destination, possible paths are observed, gain is being calculated for each route and route with maximum gain is being considered as the best route for that source-destination pair. Blocking probability can be defined as the probability of call losses for a group of identical parallel resources. Here for a given wavelength number and a given load, blocking probability of each node is being calculated and analyzed how it varies when gain margin varies, also no of routes and no of wavelength.