Cooperative clustering models for Vehicular ad hoc networks. (c2013)

Abstract

In this thesis, we address the problem of clustering in Vehicular Ad Hoc Networks (VANETs) using QoS-OLSR protocol in the presence of selfish nodes. The QoS-OLSR is a clustering protocol that aims to prolong the network lifetime in Mobile Ad Hoc Networks (MANETs) by considering the bandwidth and energy parameters to calculate the Quality of Service (QoS) metrics. However, this protocol ignores the mobility metrics that characterize the vehicular topology. In fact, the high mobility of vehicles leads to frequent disconnections in the clusters and alters the QoS over the network. Moreover, the presence of selfish nodes would hinder the application of any clustering model. These nodes behave rationally and tend hence to maximize their gain regardless of the negative implications that may affect the network. Thus, this thesis is concerned with introducing a clustering model that aims to form stable clusters and maintain the stability during communications and link failures, while satisfying the Quality of Service requirements. This is achieved by (1) considering the high mobility metrics while computing the QoS, (2) using Ant Colony Optimization for MPRs selection, and (3) using MPR recovery algorithm that is able to select alternatives and keep the network connected in case of link failures. Moreover, the clustering model is accompanied with a Dempster-Shafer based model that detects the misbehaving vehicles and regulates the cooperation by (1) using cooperative watchdog model where evidences are collected by the different watchdogs and aggregated using Dempster-Shafer to make the final decisions, and (2) punishing the misbehaving vehicles by the different network nodes. Mathematical analysis and simulations are conducted to evaluate the performance of the proposed models.