Heterogenous Quorum-Based Wake-Up Scheduling in Wireless Sensor Networks

We present heterogenous quorum-based asynchronous wake-up scheduling schemes for wireless sensor networks. The schemes can ensure that two nodes that adopt different quorum systems as their wake-up schedules can hear each other at least once in bounded time intervals. We propose two such schemes: cyclic quorum system pair (cqs-pair) and grid quorum system pair (gqs-pair). The cqs-pair which contains two cyclic quorum systems provides an optimal solution, in terms of energy saving ratio, for asynchronous wake-up scheduling. To quickly assemble a cqs-pair, we present a fast construction scheme which is based on the multiplier theorem and the (N, k, M, l)-difference pair defined by us. Regarding the gqs-pair, we prove that any two grid quorum systems will automatically form a gqs-pair. We further analyze the performance of both designs, in terms of average discovery delay, quorum ratio, and energy saving ratio. We show that our designs achieve better trade-off between the average discovery delay and quorum ratio (and thus energy consumption) for different cycle lengths. We implemented the proposed designs in a wireless sensor network platform of Telosb motes. Our implementation-based measurements further validate the analytically-established performance trade-off of our designs.