An optimized link state routing protocol for real-time application over Vehicular Ad-hoc Network

Abstract

Voice over Internet Protocol (VoIP) provides good services through Vehicular Ad-hoc Networks (VANET) platform. These networks encounter various challenges to support voice calls with acceptable Quality of Service (QoS). The Optimized Link State Routing Protocol (OLSR) is used to investigate the performance of VoIP applications in the VANET network. The network was tested before and after running the OLSR algorithm, the testing focused on Quality of Service (QoS) parameters like end-to-end delay, delay variation (jitter), and probability of packet loss between two moving hops through multi-hop Ad-hoc networks in different scenarios, using the ITU G.711 VoIP codec. After measured the end-to-end delay, jitter, and probability of packet loss for two nodes the algorithm decreased delay by 18.72%, while decreased jitter by about 20.42% and decreased packet loss by about 128.6%. However, The OLSR has shown initial good performance for four hops, and then added more hops the delay exceeded 400 ms which is not acceptable according to ITU-T recommendations. This was achieved by implementing a testbed to extract the desired results as opposed to using a simulation.