Abstract: As an application of mobile ad hoc network in the transportation realm，Vehicular Ad hoc Network（VANET） is a promising technology in Intelligent Transportation Systems（ITS）.Different with the network simulation method in the current researches，a prototype system of vehicular ad hoc network is built.A small scale network is formed by four nodes and it is also fully tested in real roads.The feasibility of the inter-vehicle communications in ad hoc manner is validated.The impact made by scenario and vehicle mobility on the wireless signal transmission is also quantitatively assessed.Several conclusions are drawn from the field tests for network protocol design and network deployment in the future.

Key words: vehicular ad hoc networks, prototype system, field tests

摘要： 车载Ad hoc网络（Vehicular Ad Hoc Network，VANET）是移动Ad hoc技术在交通领域的应用，已成为智能交通系统中一项非常有前景的技术。与当前绝大多数研究采用网络仿真实验的方法不同，设计并实现了包含4个节点的车载Ad hoc网络原型实验系统，并在实际道路上进行了实景测试实验，对VANET网络技术的可用性进行了验证，量化评估了实际环境和节点移动性对无线信号传输的影响。通过分析实验结果得出了一系列结论，为网络协议的设计和网络实际部署提供重要的参考。

关键词: 车载Ad hoc网络, 原型系统, 实景测试