A distributed synchronous clock for sensor networks

Common time-scale enables a wide range of applications and functionalities of a sensor networks. This paper proposes a clock synchronization method fulfilling the requirement of high precision and low energy consumption for large-scale sensor networks. It uses DAC embedded in microcontroller and voltage-controlled oscillator (VCXO) to act as local variable clock source which has the same frequency with the global clock after initialization. When this digital synchronous clock (DSC) at data link layer is in fine tune state, only low overhead communications are needed to maintain the synchronization of the clocks and show much more accuracy.