et the desired per user application layer throughput, and propose extensive extensions of process sharing model to incorporate important UMTS radio and transport functions and network topologies. The objective of the dimensioning process is to minimize the total link bandwidth in the network, while still being able to provide a certain average throughput for elastic traffic flows. The presented results show how the processor sharing models, which in principle only relate to a single link, can be applied to a multi-lub RAN network. Dimensioning for Circuit-switched Traffic for the user-relevant QoS Circuit-switched traffic is related to applications and services with real-time critical demands, which require Connection Admission Control (CAC) in order to guarantee the desired QoS. The objective of the dimensioning process is also the minimization of the total bandwidth in the network. Capacities need to be assigned in a way that call blocking probabilities do not exceed a certain threshold and that packet-level QoS of accepted flows is guaranteed throughout their duration. The presented corresponding dimensioning model is based on the Multidimensional Erlang (MD-Erlang) model. Dimensioning for the network-relevant QoS For dimensioning to meet the desired network-relevant QoS, the proposed analytical models are based on queuing models, which are focused on the packet level taking the characteristics of the aggregated lub traffic into account. The proposed queuing models define an appropriate arrival process to capture the important characteristics of the aggregated traffic on the link, and an accurate server process considering the packet length distribution and the given link capacity. In the mix traffic scenario, scheduling function is considered in the queuing models taking into consideration of the potential multiplexing gain. 9 Conclusion and Outlook In this thesis, the MMPP and BMAP arrival process model are proposed and investigated for the ATM-based RAN. For modeling a single lub link, MMPP/D/1 or BMAP/D/1 