自组织异构网络中降低阻塞的垂直切换算法

道路中车流量密度比较大时，会有大量车辆终端接入车辆异构无线网络，易造成网络阻塞，对此，提出结合自组织网络的自组织异构网络方法.当网络未发生阻塞时，车辆终端采用效用函数算法在基站或者接入点之间进行网络选择；当网络可能发生阻塞时，首先通过分簇算法将自组织网络划分为若干簇；然后进行车辆状态之间的转化；最后根据车辆状态选择接入算法.仿真结果表明，所提算法降低了网络发生阻塞的概率，提高了系统的吞吐量.

Vertical Handoff Algorithm for Reducing Congestion in Ad Hoc Heterogeneous Network

The combination of Ad hoc and heterogeneous network with infrastructure was proposed to alleviate network congestion. When the network was not congested, the vehicle terminal used utility function algorithm to select network between the base stations or the access points in order to complete the vertical handoff quickly. When the network was congested, firstly, the Ad hoc was divided into several clusters by clustering algorithm; then, the transition among vehicle states was carried out; finally, the access algorithm was selected according to the vehicle status. Simulation results show that the proposed algorithm reduces the probability of network congestion and improves the system throughput.