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 A preliminary version of this paper was published in the Proceedings of the 2007 IFIP International Conference on Embedded and Ubiquitous Computing (EUC 2007) [9]. Since then, the paper has undergone a major extension. Specifically, we have incorporated all the comments/suggestions of the conference attendees into this version, and expanded nearly all the sections (especially Sections 1, 2, 3, and 4). As a result, this journal submission is a much more thorough and authoritative presentation of our work. L.-J. Chen Institute of Information Science, Academia Sinica Tel.: +886-2-27883799 ext. 1702 Fax: +886-2-26518661 E-mail: [email protected] T. Sun PacketMotion, Inc. N.-C. Liang Google, Inc. 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.