Wavelength assignment of FBG sensor network based on Pareto multi-objective optimization

There is a bottleneck in the wavelength division multiplexed(WDM) fiber Bragg grating(FBG) sensor network.The conventional WDM technique requires that each FBG sensor in the array must occupy a unique spectral region.It seriously limits the maximum number or the measurement range of sensors in the network.In order to improve the performance of a WDM FBG sensor network,the Pareto-based multi-objective optimization technology is introduced to design an optimal wavelength assignment in this paper.The two objectives are used to minimize the spectrum overlapping area and the bandwidth of the optical source.In this multi-objective model,there are a set of acceptable trade-off optimal soulutions,called Pareto front.The non-dominated sorting genetic algorithm II(NSGA-II),which is one of the most efficient and famous multi-objective evolutionary algorithms,is applied for obtaining the Pareto front.The achieved Pareto front can help the decision maker to select a suitable solution.Simulation reslts show that the Pareto optimzal solutions provide good wavelength assignments for various ovelapping spectra and the proposed approach is effective in saving the source bandwidth and increasing the number of FBG sensors in the WDM FBG sensor network.