Research On MAC Protocol For Vehicular Ad Hoc Network

Vehicular Ad Hoc Network (VANET) is one of the fundamental parts of intelligent transportation systems (ITS). VANET should be able to deliver time-critical emergent message for driving assistance or accident avoidance and meanwhile support data-oriented application, such as internet access. VANET is supposed to make traffic system much safer, more efficient and more convenient.This paper analyzes the different requirements of safety applications and data applications in VANET. Based on studying on the multi-channel MAC protocols which were proposed, this paper points out the problems which need to be resolved in multi-channel MAC protocol of VANET and proposed a improved MAC scheme. This paper includes following parts:1. As safety applications and data applications have different requirements, this paper proposed a improved scheme for multi-channel MAC protocol in VANET. The scheme uses cluster head to allocate the resources of broadcast channel. The scheme supports reliably broadcasts and improve the quality of the exchange of channel status list. Therefore, longer time slot can be allocated to used for data transmission and improve the throughput of VANET.2. This paper presents a traffic information aggregation and propagation scheme, which is suitable for the city environment and based on VANET to improve the traffic condition. The traffic messages can help drivers to choose a better route and prepare against the traffic events. It's useful to avoid the occurrence of traffic jam and traffic accidents with low network overhead.