Reducing synchronization error in wireless sensor nodes by using previous timing information as training data: poster abstract

Many wireless sensor networks benefit from one type of time synchronization protocols. However, due to different crystal oscillators and clock sources in the nodes, even with drift-management techniques, synchronization error starts increasing fast after a few to tens of seconds. To keep the error low in minute-long sessions, typically the master transmits packets periodically to reset the error. These extra packets increase power consumption of all nodes especially in long sessions. Here, we propose AdaptSync that uses the timing/error information of a short period of time at the beginning of a session to reduce the error in the rest of the session independent of the master. Implementation steps are discussed and tested on sensor nodes that use Bluetooth as the wireless link. Experimental results show that in 10-minute long sessions, average synchronization error is reduced 7x compared to normal synchronization.