Loop Optic Design Optimization Study

This paper reports the results of a study aimed at understanding the design process for fiber optic systems in subscriber lines, also known as loop network. Since loop spans are typically shorter and traffic volumes lower than interoffice trunks, the required performance level of a fiber optic system is often less than the maximum Obtainable from the technology. This affords us an opportunity to save money by designing a fiber optic system truly tailored to the application. The design problem is approached from an optimization point of view. A nonlinear programming model was formulated and solved for determining the optimal values of fiber attenuation, splicing loss, system gain and operating wavelength. The sensitivity of key parameters has been studied. We show that considerable savings can be realized if the components are selected based on the optimum values given by the model. The cost penalty is also calculated for nonoptimum designs. This study lays the groundwork for developing design techniques to be used by engineers in designing fiber optic systems and also for establishing the technical requirements of various fiber optic system components.