Abstract
The IEEE 802.11 standards provide multi-rates capabilities; therefore, network devices adapt their transmission rate dynamically under varying conditions to achieve high network performance. Rate adaption is a critical component of network performance. High mobility environment and large transmission distance are challenging problems. These problems cause dramatically degradation in wireless network performance. In this paper we will present a solution to overcome these problems based on RRAA. There are two main contributions of the paper: introducing/updating performance evaluation study conducted in IEEE 802.11 networks for most existing rate adaptation algorithms; the simulation results showed that the RRAA has the best performance except for long transmission distance and mixed mobility channel condition and (ii) introducing a modified RRAA algorithm to address the weakness of RRAA. Modified RRAA uses hybrid technique between fixed and adaptive rates. Moreover, it uses adaptive packet size during transmission to achieve maximum throughput of channel. The extensive experiments showed that, Modified RRAA outperforms pure RRAA solutions; with throughput improvement up to 63.27 % in scenarios containing mixed mobility at long transmission distance between nodes.