An Evaluation Study of Mobility Support in ZigBee Networks

Based on the IEEE 802.15.4 LR-WPAN specification, the ZigBee standard has been proposed to interconnect simple, low rate, and battery powered wireless devices. The deployment of ZigBee networks is expected to facilitate numerous applications, such as home healthcare, medical monitoring, consumer electronics, and environmental sensors. For many of the envisioned applications, device mobility is unavoidable and must be accommodated. Thus, providing ubiquitous connections to/from a mobile device is crucial for various future ZigBee applications. Knowledge of how nodal mobility affects the ZigBee routing protocol is important, but the lack of ZigBee simulator support has limited the amount of research, evaluation, and development in this area. Thus far, researchers have been unable to analyze and evaluate the impact of mobile applications via extensive simulations. In this paper, our contribution is threefold. First, we present an initial implementation of the ZigBee network layer in NS-2, which will allow further research and development to be conducted in this area. Second, we analyze the adequacy of current provisions for dealing with different mobility cases. Third, we provide a comprehensive set of simulation results that demonstrate the inefficacy of the current standard for handling mobility. Our results show that the ZigBee device plays a significant role in determining the routing performance in mobile scenarios.