A hybrid MAC layer for localization and data communication in ultra wide band based wireless sensor networks

This paper presents a hybrid MAC layer design for UWB based sensor networks to handle multiple access with the ability to combine localization and data communication. UWB networks allow high precision ranging and robust data communication in harsh environmental conditions and for this are well suited for typical automation applications. To minimize localization errors in this applications, e. g. by moving sensor nodes, rangings have strong realtime requirements and must be done in a distinct pre-defined order. This can not be guaranteed in common MAC layer implementations, which are typically based on the IEEE 802.15.3 standard with contention access (CSMA/CA) and contention free access part (TDMA). The MAC scheme proposed in this paper overcomes this limitations as the contention access part is replaced by a TDMA/CDMA scheme. Evaluation results presented in this paper show that this novel approach outperforms existing schemes and fulfils the requirement for realtime ranging and communication.