Performance quality evaluation with VoIP traffic aggregation in Mobile Ad-Hoc Networks

Abstract

VoIP traffic over Mobile Ad-Hoc Networks (MANETs) faces many interacting challenges such as the mobility of the nodes that leads to continuous link breakages, the restricted bandwidth availability, the different characteristics of the existing routing protocols, the used voice codecs, the number of the mobile nodes and the background traffic. These factors introduce variability in the latency and the packet loss rate, which in turn severely affects the voice quality that is closely related to the voice codecs used by the VoIP network. This paper examines the effects of these factors to the quality of the VoIP traffic over a MANET via extensive simulations. It also presents ways to improve the performance, based either on the routing layer or on the application layer with the aggregation of multiple voice payloads to a single packet. This aggregation significantly improves the performance of the G.711 codec, while the impact to the other codecs is negligible.