cket scheduling in this QoS framework is Weighted Fair Queuing (WFQ). It defines a weight associated to each service class, according to which the bandwidth is shared. The applied QoS mechanisms will have impact on the utilization of the transport resources, and as a consequence influence the outcome of the dimensioning. In this thesis, the proposed dimensioning models consider the effect of the deployed QoS functions. Network Topologies In this thesis, two logical network structures are investigated for the dimensioning of the lub interface, as shown in Figure 1.2. The first structure has only a single link between the Node B and the RNC, which is the most basic and simple structure for the lub interface. The second structure considers a star network topology for the lub interface, where a number of Node Bs are aggregated to an intermediate switch or router that is connected to the RNC over a backbone link. The link between the Node B and the intermediate switch or router is called last mile link. last mile link Node B single link backbone link Node B Node B Switch/router Node B lub Interface lub Interface (a) single link (b) star topology Figure 1.2: Investigated network structures 1.5 Thesis Overview The single link case (a) is the most basic logical network structure. It is used to derive and demonstrate the fundamental analytical dimensioning models in this thesis. Furthermore, dimensioning of a single link can be used for dimensioning individual links in the networks. However, the UTRAN is typically a tree-structured access network with several aggregation stages. The star network topology (b) represents the basic single-stage aggregation of a tree structure. In (b), the traffic is aggregated at the backbone link, which can thus achieve certain multiplexing gain as a consequence of aggregation. The purpose of dimensioning such a star-structured network is to investigate the potential multiplexing gain which can be achieved at one aggregation stage. Given the number of aggregation stages and the amount of tr