Suitability of the wireless testbed w-iLab.t for VANET research

Two quite different tools are normally used in the research of Vehicular Ad Hoc Networks (VANET). Simulators are practical and cost-efficient, but are not entirely accurate representations of the real life situation. Field operational tests (FOT) provide exactly the opposite characteristics. A wireless testbed is situated somewhere in between, but has not yet been applied in VANET research. In this paper it is researched if such a wireless testbed could be suitable for this kind of research. The corresponding requirements are defined, and it is investigated how the generic indoor wireless testbed w-iLab.t can be made compliant using only software adjustments. Proposed techniques are an approximation of the IEEE 802.11p standard using. 11a hardware, the emulation of mobility based on link impairment, and the use of low transmit power together with manual topology configuration. These techniques are generic, and can be applied on other wireless testbeds. However, some limitations have to be taken into account. For the highway setting, w-iLab.t can provide densities up to 25% of the actual maximum VANET density in intense but flowing traffic. Experiments representing urban scenarios are labour intense and limited in topology size. Based on these observations, it is concluded that a generic wireless testbed is a valuable but complementary tool in VANET research.