n slow fading margin, to get a higher 95% location probability the slow fading margin has to be increased, which also has an effect on the maximum allowed path loss. The cell range is dependent on the maximum allowed path loss and therefore improvement in the location probability causes a decrease in the cell range. Radio Network Planning and Optimisation The cell range leads to calculation of the coverage threshold, which is the minimum allowed downlink signal strength at the cell edge with a certain location probability. For the coverage threshold calcu- lations are needed for the MS isotropic power, propagation model with calculation parameters, stan- dard deviation, area type correction factor and building penetration loss. Using the standard deviation and location probability the value of the slow fading margin is first calculated. Area type correction factors come from the propagation model tuning measurements. Building penetration loss is needed in the case where indoor coverage thresholds are calculated. ETSI recommendation 03.30 suggests values for the average building penetration loss (BPL); in urban areas it is approximately 15 dB for 1800 MHz and 18 dB for 900 MHz and in rural areas around 10 dB, due to the smaller size of buildings. For an indoor coverage threshold calculation the deviation of building penetration loss indoor is also needed, which is used as the standard deviation indoor. The approximate value for the BPL deviation is 10 dB. Table 2.9 shows an example of cell range and coverage threshold calculations for three different area types: urban, suburban and rural. The network basic parameters are frequency GSM 900 MHz and location probability 90% for indoor and 95 % for outdoor. The link budget, which is used as the basis for these cell size and coverage threshold calculations, gives 100 dBm for the isotropic power. The MS RX sensitivity is -102 dBm (for class 4 mobile) and 2 dB is used for the interference degradation margin. The area type correction factors are the same as those given in