ATM transport between UMTS base stations and controllers: supporting topology and dimensioning decisions

The access transport infrastructure of a cellular communications network represents a significant proportion of the total network cost. This prevents the network designer from over-dimensioning these links. In the case of UMTS (universal mobile telecommunications system) access network, the use of a packet-switched technology (ATM for the first Release of the system) and the multiservice nature of the traffic to be carried rise the dimensioning process complexity. At this respect, we have developed a simulation tool for supporting the network designer when making dimensioning and physical topology decisions related to Iub interface (between each UMTS base station and its controller), which is the most critical interface of UMTS access network. This simulator is capable of modelling the presence of multiple traffic classes as well as the Iub transport protocol stack with enough accuracy; it offers a graphical configuration interface and has been designed to have a great flexibility when choosing topologies and ATM configurations.