Application-Aware Scheduling of Networked Applications over the Low-Power Wireless Bus

Recent successes of wireless networked systems in advancing industrial automation and in spawning the Internet of Things paradigm motivate the adoption of wireless networked systems in current and future safety-critical applications. As reliability is key in safety-critical applications, in this work we present NETDAG, a scheduler design and implementation suitable for real-time applications in the wireless setting. NETDAG is built upon the Low-Power Wireless Bus, a high-performant communication abstraction for wireless networked systems, and enables system designers to directly schedule applications under specified task-level real-time constraints. Access to real-time primitives in the scheduler permits efficient design exploration of tradeoffs between power consumption and latency. Furthermore, NETDAG provides support for weakly hard real-time applications with deterministic guarantees, in addition to heretofore considered soft real-time applications with probabilistic guarantees. We propose novel abstraction techniques for reasoning about conjunctions of weakly hard constraints and show how such abstractions can be used to handle the significant scheduling difficulties brought on by networked components with weakly hard behaviors.