LWSN, Time Synchronization, Data Aggregation, Link-Layer Protocol, Energy Signature

Time synchronization is of tremendous importance in networked systems, especially in distributed network systems namely Wireless Sensor Networks (WSNs). WSNs extensively utilizes the time synchronization aspect for coordination and correlation of distributed entities and events (e.g., data fusion, synchronized sleeps and wake-ups, channel sharing etc.). They are typically designed with very stringent constraints, due to their inherent properties like limited resources of energy, storage, computation and bandwidth combined with the ambient conditions and application specific requirements, making traditional synchronization methods unfeasible. Hence, numerous design parameters including the form factor, precision, processing time and power, memory, overhead traffic, efficiency and scalability has led to extensive research of time synchronization relevant to WSNs over the past decades. In this paper, we investigate the linear WSNs or LWSNs and propose a network wide time synchronization method for a multi-hop linear network along with a robust protocol. Furthermore, the protocol is equipped with data aggregation and simple error handling features. Instead of proposing a new algorithm, we will reuse an existing synchronization algorithm. The system was tested on realistic test-beds. Through experimentation we conclude that increasing the synchronization window increases the synchronization accuracy with a shorter network lifetime. Moreover, the joint impact of relative offset only, and relative offset and drift on the synchronization accuracy was studied. Tests exhibit a higher accuracy for smaller synchronization windows i.e. use of offset parameter only is sufficient to achieve tolerable levels of accuracy. Needless to say, the energy consumption also can be lowered using offset only during time synchronizations for shorter windows.