异构网络的垂直切换仿真建模及其性能评估

针对无线网络的异构化趋势，对WLAN和UMTS形成的异构网络进行扩展，使其包含WLAN, WiMAX和UMTS 3种网络。基于介质独立切换对扩展后异构网络中的垂直切换进行仿真建模。评估切换时延、切换期间的丢包数目和网络使用效率，结果表明，链路即将断开(LGD)方式的切换时延小于链路断开(LD)方式，且丢包数较少，网络使用效率随着功率强度门限系数的增大而降低。

Simulation Modeling of Vertical Handover in Heterogeneous Network and Its Performance Evaluation

Aiming at the heterogeneous trend of wireless network, this paper extends the heterogeneous network composed of WLAN and UMTS, and makes it contain WLAN, WiMAX and UMTS. Simulation model of vertical handover in extended heterogeneous network is built based on Media Independent Handover(MIH). It analyzes the handover delay, packet loss count and network usage efficiency during the handover period. Simulation results indicate that Link Going Down(LGD) mode has little handover delay and packet loss count than Link Down(LD) mode. The network usage efficiency decreases when the power level threshold coefficient increases gradually.