考虑车联网中待测节点的快速移动性及实现方式多样性等特点,应用网络断层扫描技术,设计并实现了一种面向车联网的无线网络试验床。试验床主要包括网络性能测量单元和测试区域上下游探测单元。用试验床测试了车联网中测试车快速移动对网络性能的影响。测试性能指标包括网络往返延迟、网络丢包率、网络平均吞吐率等。测试结果表明:随车联网中测试车平均行程速度的增大,无线网络性能指标呈下降趋势。当测试车平均行程速度达到70 km·h-1以上时,各项性能指标与20 km·h-1时相比下降明显,网络平均往返延迟增加约2.4倍,丢包率提高约10倍,网络平均吞吐率下降约2.6倍。可见,试验床能够实现对车联网无线网络性能指标的有效测量和评估。
Considering the features of rapid mobility and realizing way diversity of tested nodes in the internet of vehicles,a wireless network testbed oriented internet of vehicles was designed and implemented by using network tomography technology.The testbed was composed of network performance measurement units and up-down stream detection units of testing area.The impact of rapid mobility of test vehicle on network performance was tested by designed testbed.The performance indexes were composed of round-trip delay,packet loss rate,average throughput, etc.in the network.Test result indicates that wireless network performance indexes degrade with the increase of the average speed of test vehicle in the internet of vehicles.When the average speed of test vehicle is more than 70 km · h-1 ,all performance indexes decrease significantly comparing to the situation of 20 km·h-1 .Average network round-trip delay increases about 2 .4 times, packet loss rate increases about 10 times,and average throughput decreases about 2. 6 times.Obviously, the wireless network performance indexes of internet of vehicles are measured and evaluated effectively by the designed wireless network testbed oriented internet of vehicles.3 tabs,5 figs,18 refs.