Research on CAC with bidirectional overflow under practical mobile model

Mobile model and call-overflow are very important for heterogeneous hierarchical wireless networks. In this paper,a practical mobile model applied to city is firstly set and analyzed. Then,the call access control scheme using bidirectional call-overflow is improved,which can make the fast calls access to microcells and slow calls back to macrocells more reasonable. Based on the mobile model,several different call-overflow schemes are simulated at last. The simulation results show that the improved bidirectional call-overflow scheme can decrease the blocking probability and dropping probability of fast calls and increase the channel utilization of overall heterogeneous system.