دانلود رایگان مقاله تقاطع مبتنی بر مسیریابی ترافیک آگاه در شبکه وابسته به رسانه یابرندگر شهری

abstract:

One of the important characteristics of VANETs is the multi-hop communications, which provides Vehicle-to-Vehicle(V2V) communication for many applications. In order to adapt to mobility in high speeds and limited-time communication links, traffic aware routing was proposed in many research works. As a type of position based routing protocols, traffic aware routing utilizes vehicles’ positions and traffic status as two main routing parameters. However, providing real-time measurements for traffic status on each road generates high network overhead. In addition, to make such measurement always updated and available for routing purposes, the measurement process has to be applied frequently. This paper introduces a Lightweight Intersection-based Traffic Aware Routing (LITAR) protocol for V2V communication in urban vehicular networks. LITAR introduces two new algorithms to reduce the network overhead generated by the traffic status measurement process while preserving the accuracy of measurement. Moreover, LITAR make routing decisions based on vehicular directional density, Road Network Connectivity (RNC) and distance towards destination. The evaluation of the proposed LITAR protocol shows significant performance improvements in terms of packet delivery ratio, while reducing communication overhead as compared to existing routing approaches.

5. Conclusions

Intersection-based Traffic aware routing protocols have the ability to adapt to VANETs dynamic environment, as routing decisions are made based on traffic and network conditions. However, employing a real-time measurement process for the traffic and network status generates high network overhead, which degrades routing protocol performance. LITAR protocol introduced two algorithms for reducing the network overhead generated by the real-time traffic and network status measurement process. The first algorithm (EVPC algorithm) eliminated the number of unnecessary generated collector packets, which are used by the real-time measurement process. The second algorithm (RCPR algorithm) restricted the number of collector packet replies. In addition, LITAR route data packets based on three metrics; directional vehicular density, road network connectivity and distance towards destination. Simulation results show that LITAR performs better than iCAR and EGyTAR in terms of packet delivery ratio, end-to-end delay, real-time measurement accuracy and routing overhead. Accordingly, LITAR should be able to provide stable and efficient V2V communication in urban environment. For future work LITAR will be tested on more complicated city maps. In addition, a research will be carried out to investigate how LITAR can be utilized to provide V2I communication based on traf- fic conditions.