Survey of NGN migration profiles deployed by selected carriers in Europe, North America and Asia

The paper presents the alternative migration profiles to next generation carrier network architecture. It describes the paths of development of fixed public network in- frastructure for five selected service providers. The carriers are selected as being in advanced stage of migration towards NGN. Moreover, examples of varying strategies ranging from full PSTN replacement and NGN overlay to constructing an NGN network from the ground up as well as examples of various migration strategies, especially based on IMS and softswitch solutions are presented.