TIME SYNCHRONIZING METHOD IN WIRELESS SENSOR NETWORKS

摘要

PURPOSE: A time synchronizing method in a wireless sensor network is provided to reduce message transfer times according a time synchronization performance, thereby reducing both network communication overhead and energy consumption of node. CONSTITUTION: An initial synchronization message is transmitted form upper sensor node to loser sensor node. A synchronization pulse message is transmitted from the sensor node to the upper sensor node. A synchronization ACK message is transmitted to the lower sensor node. A timer offset is calculated based on time stamp information(T1~T6) and timer value is corrected.