An Improved KNN Based Decision Algorithm for Vertical Handover in Heterogeneous Wireless Networks

Terminals in heterogeneous wireless networks perform horizontal handovers in a homogeneous network and vertical handovers between different types of networks. The decision of access location depends on not only the physical layer parameters, such as signal quality, hut also other attributes as communication cost, handover delay, and so on. If the vertical handover decision is classified into a multi-attribute decision problem, the difficulty of solving the attribute weights increases, with the increasing number of decision attributes. Moreover, it is more subjective to compare the relative importance of two attributes. To solve this problem, this paper proposes a vertical handoff decision algorithm in heterogeneous wireless networks, which is based on an improved KNN with less sample data and lower complexity. All decisive attributes are treated as data items and the different access locations are mapped into unique tags. The decision of terminal is determined by the distance improved. The simulation results shows that algorithm proposed in this paper can improve the throughput, reduce drop rate, which improves the resource utilization of the overall system.