Research On Trace Replay Algorithm And Routing Protocol In Vehicular Ad-hoc Network

The research of routing protocol in Vehicular Ad-hoc Network (VANET) has always been a hot topic. Real vehicle tracking data plays an important role in the performance evaluation of routing protocol. Most of the vehicle tracking data, however, were collected periodically and could not meet the requirements of real-time by many applications. Existing trace interpolation algorithms use uniform interpolation methods, the result of which have low accuracy problem and can't represent the real vehicle trace.Through lots of experiments we find that there are two main reasons that influence vehicle's trace, one of which is the surrounding road property including speed limit and intersection traffic lights, the other is the speed of same direction moving vehicles. With this observation, we proposed a novel trace interpolation algorithm. Our algorithm use Intersection Vehicle Movement Modeling (IVMM) and Velocity Data Mining (VDM) to assist the interpolation process.Road information and vehicle density are used to assist the routing process with the evolution of geographic routing. However there is no effective solution to get vehicle density. Experimental results show that vehicle density has the feature of periodic variation. We designed a new geo-proactive overlay routing algorithm according to this special feature, with its recovery strategy and overlay network maintenance strategy.Experimental results on real Shanghai urban taxi GPS data show that trace interpolation based on IVMM and VDM has much higher accuracy than regular interpolation method, and the proposed History Information Assisted Geographic Routing (HIAGR) algorithm achieves good performance as well.