Sensitivity of Handover Performance to Path Loss Exponent: A Variable Hysteresis Margin based Handover Initiation Algorithm

Abstract

In this paper, we analyze the sensitivity of handover initiation algorithm to path loss exponent. The effect of the propagating model parameters on both the mean number of handovers, and handover initiation delay are investigated. The algorithm is based on signal strength measurements using relative signal strength with hysteresis margin approach. The mean number of handovers is estimated for a single trip of mobile station from one base station to another, henceforth referred to as handover rate. Different path loss exponents varying from 2 to 8 are used for the simulation and the corresponding impact on handover rate and delay was studied. It is observed that handover rate depends on the path loss exponent. In a nonuniform environment, path loss parameters may be different and a given handover scheme cannot give optimum results consistently in the entire cellular network. A variable hysteresis margin based scheme for optimum handover performance under different propagation environments is proposed. The simulation results yield optimized tradeoff between handover rate and handover initiation delay.