nciples. The report can be used as base information for the dimensioning process. 4.1.2 Network Dimensioning The objective of dimensioning is to model an operator network based on subscriber and traffic forecasts to produce a technically optimum model of the network. The network model is presented in a master plan indicating the selected network architecture and the amount of nodes needed during the roll-out of the network. Planning a network over several phases is done by starting with the last phase first. The network should be dimensioned in such a way that it can handle the traffic at the end of the phase. The pace of the subscriber growth determines the phases (in the ideal situation of unlimited resources). At the end of each phase the master plan should be reviewed and modifications for the upcoming phases can be made if necessary. Core Network Planning and Optimisation Different things will influence the design, such as Network architecture Quality and performance goals Subscriber traffic profile Service penetration and profile Traffic growth estimates The planner has to consider everything that will affect the outcome of the final network design. For the dimensioning process the dimensioning principles are needed. They are collected during network assessment. Switching Locations The switching locations are selected based on available floor space in operator sites and traffic intensity. In general, network elements should be placed in sites with high traffic intensity. Transmission lines are needed to carry traffic from sites with low traffic intensity. These, however, come at a cost to the operator and therefore switching nodes should be placed closest to main sources of user traffic in the network. Traffic Matrix The total traffic originating from a given site may be estimated according to the total number of users and service usage. The distribution of that traffic depends on the traffic matrix, which can be deduced from measurements in the existing network or modelled according to subscriber distribut