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Improving Routing Protocols to Enhance QoS in Vanet

Afsana Ahamed, University of Nebraska - Lincoln


In Intelligent transport systems (ITS), vehicular ad hoc network (VANET) plays an essential role in providing communication between mobile vehicles. ITS is becoming popular due to the demand for advanced cyber-physical systems and comfort applications and services needed in autonomous vehicles. VANETs support vehicle-to-vehicle and vehicle-to-infrastructure data communication. Their performance solely depends on the routing protocols in the network layer, which provide efficient and effective data communication. In this work, we survey the most recent issues surrounding efficient routing protocols suitable for VANETs and address their pros and cons regarding scalability, quality of services, security and privacy, energy efficiency, transmission bandwidth limitation, and broadcasting issues. Furthermore, we devise a routing protocol based on the direction vehicles are moving and their possible location to improve QoS parameters. VANET is a technology in which moving cars are used as routers (nodes) to establish a reliable mobile communication network among the vehicles. Some of the drawbacks of the routing protocols developed for this technology, such as Ad hoc On-Demand Distance Vector (AODV), include a long end-to-end delay, more overhead, and an increase in the number of packet loss. We modified the AODV routing protocols to reduce route requests (RREQ) and route reply (RREP) messages by adding direction parameters and two-step filtering. The two-step filtering process reduces the number of RREQ and RREP packets and decreases the packet overhead. In this study, we show the impact of the direction parameter in reducing the end-to-end delay and the packet loss in AODV. The simulation results show a 1.4% reduction in packet loss, an 11% reduction in the end-to-end delay. To improve the QoS further, finding a stable and reliable route for packet transmission in the network is required. One of the methods is to find the future location of the moving vehicles and design the routing table based on the stable route in the network. This requires developing an appropriate prediction model for VANET. In this study, we propose a hybrid prediction model where the future location of vehicles is predicted using the lowest mean square error (MSE). Then based on the predicted location, a trust metric is developed for each nearby node to find the network's stable route. The performance of this modified routing protocol is compared with other state-of-art methods as well as the vehicle direction parameter model. The proposed model shows a significant improvement in QoS by reducing the average end-to-end delay by 19% and reducing packet drop rate by 1.6% while maintaining the scalability and energy consumption, outperforming the other state-of-art methods. The proposed method was also compared with link prediction with direction parameter models and observed that it outperforms that model in terms of percentage of packet loss rate, throughput and average E2E delay.

Subject Area

Electrical engineering|Information Technology|Computer science|Multimedia Communications|Information science|Communication

Recommended Citation

Ahamed, Afsana, "Improving Routing Protocols to Enhance QoS in Vanet" (2021). ETD collection for University of Nebraska - Lincoln. AAI28714381.