Reliable hopping sequence design for highly interfered wireless sensor networks

Guaranteeing reliability in highly interfered environments is a challenging requirement of current and future wireless applications. A promising state-of-the-art solution for low-power wireless technologies, e.g., wireless sensor networks (WSNs), is frequency hopping aided with black- and white-listing of channels. Both methods, although increase reliability, sacrifice frequency resources. Extensive measurements of channels' packet drop probabilities show that interfered channels are not fully blocked. Motivated by this discovery, we propose the whitening - a methodology for reliable hopping sequence design without resource sacrifice. We model the efficiency of interfered ISM band channels, and study the gains and trade-offs of applying whitening in different scenarios. Application reliability is achieved by granting re-transmissions within a time deadline. Simulations and measurements, performed on the exemplary use case of Time Slotted Channel Hopping WSNs, show that the proposed methods outperform state-of-the-art solutions in the presence of interference in terms of reliability.