A performance evaluation model for RSS-based vertical handoff algorithms

Many RSS-based vertical handoff algorithms have recently been proposed. However, there are only a few models to evaluate the performance of vertical handoff algorithms and none of the existing models reflect the effect of a doorway on received signal strength (RSS). Considering that RSS from heterogeneous networks cannot be directly compared with each other, we firstly present an effective method to compare RSS of different networks, based on the corresponding bandwidth in each network. Then, we take into account signal abrupt attenuation near a doorway and construct a novel performance evaluation model for RSS-based vertical handoff algorithms. This model also reflects the correlation between RSS at two adjacent locations in a WLAN. Following that, we propose an integrative performance evaluation function based on two metrics - the decision delay and the number of handoffs. Furthermore, we analyze hysteresis and dwell-timer algorithms with our model. The results show a good match between simulation and analysis.