An optimized congestion control mechanism of Vanets for non-safety messages transmission using Taguchi method

Abstract

Vehicular ad hoc networks (VANETs) are emerging technology concept in mobile ad hoc networks (MANETs). High speed and frequent network topology changes are the main characteristics of vehicular networks and Internet accessibility. This networking technology provides vehicles with endless possibilities of applications, including non-safety, comfort and entertainment. Due to high speed and mobility of nodes and their frequent disconnections, it is difficult to design a MAC scheme in VANETs that satisfies the Quality-of-Service (QoS) quality-of-service requirements in all networking scenarios. In this thesis, we provide a comprehensive evaluation of the mobility impact on the IEEE 802.11p MAC performances. The study evaluates basic performance metrics such as delay, packet delivery ratio (PDR), throughput, as well as the impact of mobility factors. The study also presents a relation between the mobility factors and the respective medium access impact according to the changes in tested network environment. Moreover, a new discriminatory problem according to node relative speed is identified for city (eCCOM), highway (paMAC) and hybrid (inHAN) scenarios. To achieve better performance, we propose smart optimization mechanism for congestion control and algorithm to alleviate network performance degradation due to high mobility. Extensive simulation results show the significant impact of mobility on the IEEE 802.11p MAC performance, an identification of a new unfairness problem in the vehicle-to-infrastructure (V2I) communications.