Nested block designs: Flexible and efficient schedule-based asynchronous duty cycling

In schedule-based asynchronous duty cycling, nodes activate and deactivate their radio interfaces according to a specially designed wakeup schedule, which guarantees overlapping active time between nodes, irrespective of their synchronization offsets. When compared to synchronous duty cycling, such an approach has the advantage of being simple to implement, eliminating the need for synchronization protocols, complex computations or extra hardware. However, among published proposals, there is no single schedule-based mechanism that provides the lowest latency in all scenarios, when considering duty cycling symmetry, frame delivery probability and duty cycling rate. This paper introduces nested block designs, a new schedule that extends the use of block designs to application scenarios for which they were previously not possible or not as efficient as other schedules. Nested block designs provide the lowest latency among known schedule-based asynchronous duty cycling mechanisms for a wide range of applications, as confirmed by analytical models and real implementations on WSN motes.