Overview of MAC layer enhancements for IEEE 802.15.4a

Ultra wideband impulse radio (IR-UWB) based on the IEEE 802.15.4a PHY standard offers unique features which are exploitable in MAC designs for wireless personal area networks (WPANs) and wireless sensor networks (WSNs) to improve performance and robustness. To achieve this, different strategies of cross-layer optimizations to the IEEE 802.15.4 MAC using features of UWB have been proposed. This paper compares current approaches and exposes individual advantages and disadvantages regarding energy efficiency and positioning.