Robust hybrid wired-wireless sensor networks

Sensor networks are networks of sensing units that acquire data from the environment and transmit them towards a base station. Depending on the specific nature of the application and its constraints, the communication among units and from units to the base station may rely on wired, wireless or a hybrid technology. In those scenarios where units communicate through a wired technology, e.g., a fieldbus, faults, malfunctionings or accidents affecting the cable can compromise the monitoring service up to the point that the monitoring functionality is impaired. In this work we propose a robust hybrid wired-wireless sensor network architecture suitable for application scenarios where a wired monitoring system is preferable. Units are equipped with both wired and wireless interfaces and communicate data through the fieldbus unless a bus fault is detected. When a fault affecting the wired transmission occurs then the communication becomes hybrid, with some segments of bus connected by wireless each other to grant the quality of service. Particular attention has been devoted to design power-aware communication protocols and mechanisms.