Performance evaluation of multiple-rate mobile ad hoc networks

Existing wireless networks usually provide multiple data transmission rates. This paper presents a simulation study of the performance of multiple-rate mobile ad hoc networks (MANETs), based on an evolved ns-2 simulator. At the physical layer, realistic models such as the Walfisch–Ikagami radio propagation model and lognormal fading are implemented. At the link layer, a link adaptation algorithm is implemented to select an appropriate data transmission rate based on the receiving signal-to-noise ratio. At the transport and application layers, different data traffics, including constant bit rate, TCP, voice over IP, and video, are generated. We study the network performance such as throughput, delivery ratio, and end-to-end delay when position-based routing is used. We also study how node mobility and position error affect the performance. In addition, we investigate the impact of the link distance, namely the geographic distance for a hop, on the end-to-end network throughput. This work is a comprehensive simulation study on the impact of various factors on the performance of MANETs. It also provides guidelines for future protocol and algorithm design.