Capgemini Telecom & Media, La Dééfense, France and Modelling and Scientific Computing Group, School of Computing DCU, Ireland;Capgemini Telecom & Media, La Dééfense, France and Modelling and Scientific Computing Group, School of Computing DCU, Ireland;Capgemini Telecom & Media, La Dééfense, France and Modelling and Scientific Computing Group, School of Computing DCU, Ireland