EchoRing: Wireless Network Design and Evaluation for Hard Real-Time Applications

So far, the unreliability of the wireless channel has prohibited the utilization of wireless networks for so called hard real-time applications. Such applications are for example encountered in industrial automation, where high reliability accompanied with very short latencies (in the range of milliseconds) need to be provided. Nevertheless, from a pure physical layer point of view, several techniques exists which appear to be promising to reach the desired levels of reliability and latency. In this talk we discuss a novel protocol named EchoRing, which integrates a distributed MAC scheme with cooperative relaying to reach extremely high levels of reliability at short latencies (below 10 ms). The protocol development has been based on probabilistic model checking, which allows for a mathematically rigorous characterization of the system's reliability in face of deadlines. Apart from presenting the design of the system, we discuss theoretical performance evaluations of different protocol components as well as initial results from a prototypical implementation based on the WARP nodes from Rice university.