Constrained Coverage Optimisation for Mobile Cellular Networks

This paper explores the use of evolutionary algorithms to optimise cellular coverage so as to balance the trafic load over the whole mobile cellular network. A transformation of the problem space is used to remove the principal power constraint. A problem with the intuitive transformation is shown and a revised transformation with much better performance is presented. This highlights a problem with transformationbased methods in evolutionary algorithms. While the aim of transformation is to speed convergence, a bad transformation can be counterproductive. A criterion that is necessary for successful transformations is explained. Using penalty functions to manage the constraints was investigated but gave poor results. The techniques described can be used as constraint-handling method for a wide range of constrained optimisations.