growing traffic. The quality of service requirements for the cellular network, i.e. coverage, capacity and quality re- quirements, are the basis for dimensioning. The targets are specified with key performance indicators (KPIs), which show the target to meet before network acceptance. Drive testing is used as the testing Preplanning in a GSM Radio Network Table 2.1 Example coverage thresholds Area type Coverage threshold Urban (indoor) > -75 dB m Suburban (indoor) > -85 dB m In-car > -90 dB m Rural > -95 dB m method for the network functionality verification. During the verification the functionality of different services agreed with the operator has to be tested. Optimisation After the network has been launched the planning and optimisation related activities do not end because network optimisation is a continuous process. For the optimisation the needed input is all available information about the network and its status. The network statistic figures, alarms and traffic itself are monitored carefully. Customer complaints are also a source of input to the network optimisation team. The optimisation process includes both network level measurements and also field test measurements in order to analyse problem locations and also to indicate potential problems. 2.2 Preplanning in a GSM Radio Network Preplanning precedes actual network planning. The main part of the preplanning consists of dimensioning, but before proceeding with that the network planning criteria has to be agreed with the operator. 2.2.1 GSM Network Planning Criteria The definition of the radio network planning criteria is done at the beginning of the network planning process. The customer requirements form the basis of the negotiations and the final radio network planning criteria is agreed between the customer and the radio network planner. The network operator has performance quality targets for the cellular network and these quality requirements are also related to how the end user experiences the network. The network planner's main target is to 