Robustness of Uncoordinated MAC in channel impaired Low Data Rate UWB communications

Impulse Radio Ultra Wide Band (IR-UWB) is under discussion within the IEEE 802.15.4a Task Group for providing combined communication and ranging in low data rate indoor/outdoor networks. Within this framework, it is particularly appealing to design MAC layer strategies for IEEE 802.15.4a, that are tailored on the physical layer. In previous work, we proposed an UWB-tailored MAC named Uncoordinated Baseborn Wireless medium access control for UWB networks (UWB)2. Based on the pulsed nature of the UWB transmission, the proposed MAC adopts the Aloha principle, thanks to the low probability of pulse collision for low data rate transmissions. The method also enables location-based network optimization by providing and storing estimates of distance between terminals. This paper extends and completes the analysis of (UWB)2 by introducing channel impairments. Channel parameters were obtained from data made available in the 802.15.4a channel sub- committee, and include both indoor and outdoor propagation scenarios. 2 Results highlight that the (UWB) protocol is robust to multipath, and provides high throughput and low delay in the considered scenarios, with performance scaling gracefully with number of users and user bit rate. Results confirm and support the adoption of (UWB)2 principles for low data rate UWB communications. Index Terms— Ultra Wide Band, MAC, Low Data Rate