Vertical Handoff Decision Algorithm to Minimize the Network Cost

A new vertical handoff decision algorithm is proposed to minimize the cost of the heterogeneous wireless networks which comprise cellular networks and wireless local area networks (WLANs). We first calculate the block probability of new calls and the drop probability of handoff calls in cellular network and WLAN under the channel-guard call admission method, and propose a cost function which is based on the block probability and drop probability. Then we obtain the radius of WLAN by simulation annealing (SA) method to minimize the cost. All the nodes should handoff from cellular network to WLAN if they enter WLAN´s scope and handoff from WLAN to cellular network if they leave its scope. Finally, we analyze our algorithm in the condition of different new call arrival rates and handoff call arrival rates.