A time synchronization mechanism for heterogeneous wireless sensor networks

Based on the characteristic of heterogeneous wireless sensor networks (HWSNs), the importance of time synchronization for data aggregation and network coexistence of HWSNs is discussed. In addition, a time synchronization mechanism, which includes the advanced delay measure time synchronization (ADMST) and clock frequency transition mechanism, is proposed. ADMST is employed in the subnet of the HWSNs, while clock frequency transition mechanism should be employed before ADMST for synchronizing between (or among) the subnets. The test platform contains both the hardware (CC2430, MSP430F2618+CC2520) and software (protocol stack meeting IEEE 802.15.4E standard draft), and the experimental results show that the scheme can be well applied to time synchronization and realize data aggregation and network coexistence in HWSNs.