A method for synchronizing low cost energy aware sensors used in industrial process monitoring

Time synchronization is needed in distributed industrial systems. When wireless low cost energy aware sensors are used for monitoring industrial processes a new concept for time and synchronization must be developed. These sensor systems are much more heterogeneous and energy aware than traditional systems, making standard time synchronization methods inadequate. Implementation differences, energy resources and environmental conditions may greatly vary even inside one cell of sensors. This must be considered in the design. The authors propose a new time synchronization method that scales to the real synchronization requirements of the cell application. The method has been designed to be energy efficient, flexible and robust. It is based on three steps that respectively learn the system and its behavior, make coarse synchronization and perform precise synchronization according to the desired synchronization level and the energy available in each sensor. They show some early simulation results that indicate the potential of the method discussed in the paper.