Modeling of Call Dropping in Well-Established Cellular Networks

The increasing offer of advanced services in cellular networks forces operators to provide stringentQoS guarantees. This objective can be achieved by applying several optimization procedures. One ofthe most important indexes for QoS monitoring is the drop-call probability that, till now, has not deeplystudied in the context of a well-established cellular network. To bridge this gap, starting from an accuratestatistical analysis of real data, in this paper an original analytical model of the call dropping phenomenonhas been developed. Data analysis confirms that models already available in literature, consideringhandover failure as the main call dropping cause, give a minor contribution for service optimizationin established networks. In fact, many other phenomena become more relevant in influencing the calldropping. The proposed model relates the drop-call probability with traffic parameters. Its effectivenesshas been validated by experimental measures. Moreover, results show how each traffic parameter affectssystem performance.