Estimation of Signal Level Evolution for Handover in Networks with Femtocells

The deployment of small cells is one of the solutions used by the operators in order to improve their coverage and the quality of service (QoS) offered in urban scenarios. However, an increase in the amount of available cell could represent a problem for the operators due to a higher number of performed handovers. Moreover, if we take into account that the density of femtocells deployed and the number of users in the same scenario could be high, the problem of performing handover becomes even more significant. An algorithm to decrease the number of performed handovers in a scenario with femtocells deployed densely is studied in this thesis. The proposed algorithm estimates the future signal level, which the user would receive if it performs the handover to the target cell. This estimate is exploited to evaluate if handover is going to be beneficial in terms of throughput or not. The performance is compared with the conventional handover technique and with selected competitive algorithms. The results show that the proposed algorithm decreases the number of performed handovers and, in addition, it maintains an acceptable level of SINR even for the scenarios with high density of femtocells.