Research Of Mobility Management Strategy Performance Optimization In VANET

With the development of sensor devices, wireless communication devices and micro-computer systems, vehicles have been given more and more powerful capabilities. People are regarding the vehicle no longer just as a transportation, but as a network access equipment to achieve application of security and entertainment, to obtain a more comfortable and more intelligent traffic experience. A new network (VANETs) with stable, efficient and safe features come into being with vehicles as its main infrastructures. People want to use VANETs to achieve effective content acquisition and distribution. But different from the traditional TCP / IP network, vehicle mobility makes VANETs topology change drastically, and the connection between vehicles is very fragile, making the distribution of information become very difficult.In recent years, the study of VANETs has made a lot of achievements including routing, security and mobility management. But the mobility problem has not been well resolved, mainly because the current mobility management strategy is not sufficient to study the law of vehicle movement, but also not very good in combining the achievements of transportation research field with network research.This thesis first summarizes the concept and characteristics of VANETs, and combs and analyzes the mobility management methods under different wireless networks, pointing out their shortcomings. Then,real data sets are used to analyze the law of vehicle movement from both macroscopic and microcosmic angles. Combining with the research results of the mature transportation research field, a method of judging flow states is proposed, which optimizes the selection method of cluster heads in the topology management, together with a new mobility management strategy. Finally, based on the SUMO vehicle simulation platform and OMNET++ network simulation software, the mobility management strategy proposed in this thesis is simulated. Compared with other strategies, the effectiveness of improving the stability of clusters has been proved.