cfaed Seminar Series

Marco Zimmerling will present his work on exploiting synchronous transmissions for reliable, efficient, and predictable low-power wireless net-working.

The Low-Power Wireless Bus (LWB) is a communication protocol that lets nodes communicate as if they were connected to a shared bus, where all nodes can receive all packets, although the underlying multi-hop wireless topology may be way more complex and continuously changing. LWB uses Glossy as communication support, which provides two services that are fundamental to LWB's operation: one-to-all network flooding and network-wide time synchronization. That is, in multi-hop wireless networks Glossy can send a packet from one node to all others within a few milliseconds and at a reliability close to 100%, while synchronizing all nodes to within microsecond accuracy. Unlike most low-power wireless protocols, Glossy takes advantage of packet collisions rather than fighting against them. It deliberately forces multiple nodes to send the same packet at nearly the same time, thereby taking advantage of capture effects and constructive interference to harness different forms of diversity. The talk will focus on: the design of LWB and Glossy and their performance in real networks consisting of 100+ nodes, the beneficial characteristics of synchronous transmissions in Glossy wrt. network state independence and packet reception/loss statistics, thus enabling highly accurate performance models and interesting directions for future work.