Research Of Multimedia Transmission Scheme And Congestion Detection In VANETs

In recent years, with the further study of Vehicular Ad hoc Network (VANETs) and its application in intelligent transportation, traffic safety and entertainment, VANETs can improve the traffic management levels, and take active accident alarm, tips of accidents and comfort and entertainment services gain recognition of the whole society.Urban Vehicle Ad hoc is one kind of Mobile Wireless Ad hoc Network, which can provide communication inter vehicles and between vehicles and Access Points (APs) using store-carry-forward mechanism. With the development of VANETs and the deep research, VANETs-based multimedia applications cause more and more earnest concern of researcher. However, due to the characteristics of restricted mobility patterns, multi-hop routing, and wireless channel conditions, it is difficult to maintain an end-to-end path in VANETs. Moreover, unlike the general data dissemination, multimedia applications have the characteristics of high flow rate, sequential transmission and strict timing requirement. All of the factors mentioned above will make the general routing scheme invalid in the highly mobile VANETs in the process of transmitting multimedia packets. Therefore, it is urgent and necessary to propose a scheme that can meet the requirements of transmitting multimedia applications in VANETs.In this work, we propose a routing scheme of multimedia in VANETs based on Game theoretic models. Recently, Game theory has been generally used to describe the situations involving conflicts in which the payoff of certain player is affected by the actions of other players. Usually, in the relationship between competition and cooperation, every player expects to find the best strategy relative to the others, and obtains a stable output, called the Nash Equilibrium. Focusing on the denial of service of the selfish nodes and the competition for high quality nodes among multimedia streams, we propose two game models based on the Game Theory to restrain the misbehavior of nodes and multimedia streams on the premise of protecting users’privacy, which can make each player independently gain maximum benefit, and no player can increase its profit by unilaterally changing its strategy. In addition, to address the problem of the congestion detection when transmitting multimedia in VANETs, we propose an aggregate parameter based on weights which can monitor the network performance from Messages Delivered Ratio, Average Delay, Throughput and Overhead Ratio (OR). Finally, we discuss the broad application prospects of VANETs, including in the Emergency Wireless Communication Network and Vehicle Urgent Information System.