affic engineering. With traffic engineering techniques it is possible that traffic flows are either carried over single or over multiple paths between the source and the destination. Specifically, one core concept of traffic engineering is 4 Framework of UMTS Network Dimensioning routing optimization. The idea of routing optimization is to find advantageous path patterns which can achieve the best QoS for a certain traffic demand and traffic load. The applied routing and traffic engineering has significant influence on the distribution of the traffic in the network, i.e. control of the link loads on all links throughout the network, and thus their impacts on the overall traffic need to be considered essentially for the capacity assignments in the dimensioning process. 4.2.6 Summary In section 4.2, several important issues and their impacts on the dimensioning are discussed. In the framework of this thesis, the dimensioning of the lub interface will consider different traffic classes and traffic mix (elastic or circuit-switched traffic, or a mix of both), a certain network topology (either a single link or a star topology access network), traffic control functions like scheduling (e.g. strict priority, DiffServ), and different resource control functions such as CAC or BRA. However, routing and traffic engineering are not considered in this thesis. It is assumed that the network always keeps a fixed routing pattern. 4.3 Framework for UMTS Network Dimensioning The preceding sections define the objectives for the UMTS network dimensioning, and analyze the related important issues which need to be particularly considered in the dimensioning process. This section proposes a general framework for the UMTS network dimensioning and presents the complete procedure for dimensioning which is used in this thesis including the necessary steps and the required inputs and outputs. Figure 4.4 illustrates the framework for the UMTS network dimensioning. The aim of dimensioning in the context of this thesis is to decide the minimum