Research On Related Technologies Of MAC Layer In Vehicular Ad Hoc Networks

VANET(Vehicular Ad Hoc Network) is the important foundation of ITS(Intelligent Transport Systems). It aims to establish a platform for communication between vehicles, providing status information of surrounding vehicles and real-time traffic information for the driver. Communication between vehicles is the important basis of VANET. Its performance affects the communication quality of VANET directly. There are some characteristics in VANET, such as vehicles moving fast, instability of the vehicle density, channel susceptible to interference. Beside, irrational channel assignment lead to channel load unbalance and local congestive and so on. The optimization and distribution of VANET channel have got the attention of the academia, and it becomes a research focus in the field. The VANET channel’s optimization and allocation, congestion prevention and data secure transmission are introduced in this thesis.To improve the network capacity and channel utilization, a VANET channel optimization strategy based on hybrid channel allocation is probed. In this strategy, the relation between the interface number and channel allocation strategy is analyzed. And in hybrid channel allocation strategy, the interface allocation and channel scheme is mainly discussed.In the network congestion control, aiming at the particularity of VANET, a congestion prevention strategy based on buffer optimization is discussed. Some data packets are thrown away in buffer to relieve the pressure of buffer and reduce the possibility of network congestion. And memory space occupied by buffer fragment is optimal managed.For the need of security protection of sensitive data, a VANET data security transmission based on end-to-end negotiation is discussed. In this strategy, a way to obtain public key suitable for VANET is discussed. And session key is generated by consultation. Finally, transmission data is encrypted with session key to finish the security transmission.