Cross Layer Based Dynamic Handover Decision in Heterogeneous Wireless Networks

Heterogeneous wireless networks encompass different radio access technologies to offer services as per the requirements of the users at anytime and anywhere. In such networks, mobile users have to undergo vertical and horizontal handovers to realize seamless communication with guaranteed quality of service. In this paper, we propose cross layer based dynamic handover decision algorithm to maximize resource utilization and to attain high QoS. The parameters measured at different layers are used through media independent handover functionality to estimate handover requirement and to select an appropriate target network. Based on user’s preferences, different weights are assigned to handover decision parameters using fuzzy analytical hierarchical process. The weights, assigned to decision parameters, are made adaptive to call time, velocity of mobile user, type of application and remaining battery life of the mobile handset. A popular multiple attribute decision making technique, TOPSIS (technique for order preference by similarity to the ideal solution), is adopted to choose the most suitable target network. Numerical results are obtained through computer simulation for preference scores of different networks, security, end to end delay and available data rate, which show that QoS perceived by the end user is maintained consistently in varied conditions of the network and applications.