Wireless Sensor Network simulators relevance compared to a real IEEE 802.15.4 Testbed

The diversity of research topics in Wireless Sensor Networks (WSNs) is attracting more and more researchers from different fields. The common point of all proposed solutions and protocols for WSNs is the evaluation usually done with network simulators. In this paper, we focus on the results relevance of wireless sensor network simulators in different scenarios based on indoor and outdoor environments. We propose a comparative study between 3 usual simulators (NS2, OPNET and QualNet) while using as reference a real testbed based on recent Imote2 sensors. The simulators give different results even in similar environments. NS2 and Qualnet give results close to those of the experimentation in the case of an indoor environment, but in the outdoor environment Opnet gives results closer to the reality. In addition, the impact of different MAC protocols (B-MAC and TKN15.4 MAC) which observe or do not observe the IEEE 802.15.4 standard is illustrated by real experimentations. They show that TKN15.4 protocol gives a better throughput than B-MAC.