Drop call probability in established cellular networks: from data analysis to modelling

The ever increase of advanced services offered by modern cellular networks require stringent Quality of Service (QoS) guarantee, obtained as the typical result of many optimization procedures. In this paper the phenomenon of dropped calls, one of the most important indices of QoS in a large scale well-established cellular network, has been analyzed. We verified from measured data traffic that, in a well-established cellular network, models available in literature are useless to pursue the objective of service optimization: many phenomena, neglected till now, heavily influence the call termination. To relate the drop call probability to these phenomena, an original analytical model has been developed. The obtained results, validated by experimental measures taken from a real network, can allow the network operator to optimize system performance improving the offered Quality of Service and their revenue.