actor or overprovisioning factor [Rie04, GZFO07]. Link utilization: it indicates the utilization of the link bandwidth as defined in section 4.1.2.2. It is calculated as (link utilization / link bandwidth). As seen, it is equal to (1/normalized capacity). Step 1: Check the Input data Traffic demand and related characteristics Analyze traffic Network configurations Check network and parameters configurations Check QoS Required QoS requirements Step 2: Select an appropriate dimensioning approach (simulation or analytical models) Step 3: Dimensioning Process (based on the chosen dimensioning approach) Output: The minimum required link capacities for the given traffic demand and the required QoS Figure 4.5: An overview of the dimensioning procedure 4 Framework of UMTS Network Dimensioning Set an initial link capacity C Estimate the QoS for the given traffic and network scenario, under the current link capacity C using the chosen dimensioning approach estimated QoS estimated QoS Output: required QoS I <e suggested link capacities decrease link estimated QoS is Increase link worse than required capacity AC capacity AC Figure 4.6: Dimensioning process to derive the minimum required link capacities 4.4 Dimensioning Approaches This section presents an outline of dimensioning approaches which are considered in this thesis. As mentioned in the preceding section, the dimensioning approach can be basically categorized into simulation approach and analytical approach. The simulation approach relies on an established simulation model which can imitate the real system. The analytical approach is mainly based on queuing theory. In this thesis, both approaches are applied for the dimensioning of UMTS radio access network and compared with each other. simulation approach usually can provide a higher accuracy than the analytical approach, as the simulation models can contain the detailed modeling of the UMTS network (i.e. modeling the required protocol layers, the main UMTS functionalities, the network structures, the traffic genera