ements used can be: paging capacity of all BTSs in order to estimate the paging load that can be carried by the BTS; paging traffic of BTSs to use for estimating the paging traffic in the case of several BSCs having the same LA; handover statistics between BTSs in order to group BSCs having many handovers between them. Based on these pieces of information it is possible to determine an optimum LA plan that fully utilises paging capacity while ensuring that paging success is maximised (deleted paging messages minimised) and LU traffic on the SDCCH is reduced. At the end, optimisation can be assimilated with a medical check-up of the network. The optimiser first detects anomalies (symptoms) and then analyses the situation (diagnosis). After that, he/she proceeds by trying a first corrective action (treatment) and then sees the effects. If it does not work he/she tries to push more investigation by asking for a detailed analysis (scans). The optimisation process runs continuously as many operations take place in the network without interruption (adding new sites, BTS re-hosting, sites re-engineering, adding/removing TRXs, etc.). In most cases, operations are correlated between them because they are either interdependent or interexclusive. Optimisation consists of addressing three main aspects: coverage, capacity and frequency planning. Actions can then be taken according to what is identified as a problem on a cell or an area in order to perform better. Frequency plan review, handover parameters change, site-engineering correction and specific parameter applications are only examples of common optimisation actions. Adding new sites, Radio Network Optimisation new BSC or reorganising TRXs are also possible improvement solutions. Through drive testing, the NMS and trace analysis information can be obtained, faults diagnosed, new recommendations tested, parameter change implemented and the network assessed. It is important to note that performance is also dependent on handset capability. Depending on the manufacturer, 