Performance comparisons of two on-demand ad hoc routing protocols in dynamic rate shifting WLANs

Recently, many on-demand routing protocols for ad-hoc networks have been proposed, but most of these works have been done on the basis of the IEEE 802.11 standard that supports a single transmission rate. In ad hoc networks supporting the multi-rate transmission scheme, which is referred to as dynamic rate shifting in the IEEE 802.11 standard, few performance studies on ad-hoc routing protocols have been performed. In this paper, we extensively study the impact of dynamic rate shifting on the performance of ad-hoc routing protocols in various situations in multi-rate WLANs environments. Our question is whether the dynamic rate shifting scheme supported by the IEEE 802.11 standard affects the relative performance of the routing protocols being studied. We have extended the ns-2 network simulator to accurately model the IEEE 802.11b wireless LAN standard, and simulated the performance of two ad hoc routing protocols over each of networks supporting single rate and multi-rate transmissions.