GSM networks are very expensive. The network design process requires too many
decisions in a combinatorial explosion. For this reason, the larger is the
network, the harder is to achieve a totally human based optimized solution. The
BSC (Base Station Control) nodes have to be geographically well allocated to
reduce the transmission costs. There are decisions of association between BTS
and BSC those impacts in the correct dimensioning of these BSC. The choice of
BSC quantity and model capable of carrying the cumulated traffic of its
affiliated BTS nodes in turn reflects on the total cost.