QoS ENHANCEMENT IN 4G HETEROGENEOUS NETWORKS USING KALMAN FILTER & EWMA

With the advent of 4G technology interoperability between different wireless technologies can be easily achieved. In Vertical Handoff (VHO) , connection transfer switching takes place from one Radio Access Network (RAN) to another. Now a day's numerous methods are available to improve the Quality of Service in heterogeneous networks. This project concerns about enhancement of heterogeneous networks using filtering technique methods. Two technologies, UMTS and WLAN is considered for this project. The filtering techniques includes calculation of path loss and then filtering received signal strength under various propagation environments such as urban, suburban and rural. COST 231 Hata, COST Walfish-Ikegami, ECC 33, Ericsson path loss models are considered for this project. In order to improve the throughput and vertical handoff performance, appropriate filtering methods such as Kalman filtering and Exponentially Weighted Moving Average (EWMA) methods are used. Both the Kalman and EWMA filtering techniques shows an corresponding improvement in RSS and throughput.