1. Engineering Expert (Roaming and Signalling), Belgacom International Carrier Services, Rue Lebeau 4, 1000 Brussels, Belgium
2. Department of Electronic Engineering, University of Rome Tor Vergata, via del Politecnico 1, 00133 Rome, Italy
3. CTIF, Aalborg University, Niels Jernes Vej 12, 9220 Aalborg, Denmark