Concurrent Transmissions for Multi-hop Communication on Ultra-wideband Radios.

Concurrent transmissions, as popularized by Glossy, have proven an effective, state-of-the-art technique for the design of reliable and efficient network protocols. However, their exploitation is largely confined to IEEE 802.15.4 narrowband radios. In this paper, we investigate the extent to which concurrent transmissions can be applied to ultra-wideband (UWB) radios, whose popularity is rapidly growing. We adopt a system-driven approach, where techniques and codebases representative of the state of the art are adapted for UWB and evaluated in a 23-node indoor testbed yielding multi-hop topologies. We show that, once embodied in a full-fledged system, UWB concurrent transmissions yield benefits similar to narrowband, i.e., near-perfect reliability and very low latency and energy consumption, along with order-of-magnitude improvements in networkwide time synchronization. Further, our implementations suggest that existing higher-level protocols built atop Glossy require only minimal adaptation. Our results pave the way for the exploitation of concurrent transmissions in UWB, which we foster by releasing our systems as open source, enabling their immediate use and improvement by researchers and practitioners.