TS radio access network, its specific protocol stacks, important features, its specific traffic- and resource control functions and their impacts on the lub dimensioning are studied. For the dimensioning process, two basic types of traffic are distinguished, elastic and circuit-switched traffic. They are associated with non real time data applications and delay- sensitive real time services, which are identified as the two main traffic classes served in the current UMTS networks. The fundamental property of elastic traffic is its rate adaptability, which is caused by the feedback mechanism of TCP. In this thesis, the theory of processor sharing is applied to the dimensioning of the lub interface for elastic traffic for satisfying its desired end-to-end application QoS. To consider the specific UMTS functions and network structures, the basic processor sharing model has been significantly extended in this thesis to dimension the radio access networks under various scenarios of traffic, QoS framework, resource control functions, different transport technologies and network structures. In case of circuit-switched traffic, which needs to meet a guaranteed blocking probability, the classical Erlang models are applied. In addition, a number of queuing models are proposed in this thesis to dimension the lub link for guaranteeing a required transport network QoS. For validating the developed analytical models as well as for performance evaluation, several simulation models were developed in this thesis to model different UMTS radio Abstract access networks. By performing extensive simulations and analysis of the simulation results, important dimensioning rules are derived and the proposed analytical dimensioning models are demonstrated. Through validating with simulation results, it is demonstrated that the proposed analytical models in this thesis are able to capture relevant characteristics and provide accurate dimensioning results, and thus can be applied for UMTS radio access network dimensioning. At the end, a dimen