. Choice of the adequate LA size ensures high paging success rates. If it is too small, there will be high location update traffic and if it is too large, there will be some deleted paging messages due to the paging load. It is worth noting that a site re-hosting from BSC to BSC can generate many problems in the network if the operation is not properly performed and followed. This type of operation always takes place at night in order not to disturb traffic. Starting from the following day, close monitoring should be done. Hereafter are some clues on what to check. Drive Tests A comparison is done between drive tests performed before the migration and just after. In the last one, attention is particularly given to handover performance. Adjacency definitions and handover success are verified. Statistics Another way to check the handover success rate from and to concerned sites is by statistics. In fact statistics launched for a long enough period (4 or 8 hours after the operation) will give a clear idea on 100 % handover failure. Parameters An adjacency definition is crucial for the handover mechanism. Any error in CI, LAC, frequency, BSIC- NCC or BSIC-BCC means that 100 % handovers fail. Therefore adjacency tables should be checked precisely. Alarms Finally, some alarms may appear after the operation (synchronisation, transmission link... ). Their nification gives hints on possible corrective actions. Network Elements Restructuring It can be cost efficient for the operator to think of some physical re-structuring of the network in order to use the deployed capacity efficiently. A better balance between offered and used capacities can be provided through a TRX rearrangement taking account of traffic hot spots. In such an operation, the interaction between departments is high; clear procedures are very important. List Definition Potential cells are first identified (cells with high traffic and blocking require extension of TRXs and cells with low traffic need to dismantle TRXs). This operation requires the marketin