An Energy-Efficient Slotted MAC for the Real-time Applications in Industrial Wireless Sensor Networks
Md. Abul Kalam Azad; Md. Abdur Rahman; Amina Khatun
A sensor node generally wastes a high amount of energy due to a long adaptation time in encountering the dynamically changing topology of wireless sensor networks (WSNs). We know that adaptation time directly influences the reliability of data delivery. A CSMA-based protocol shows good adaptability but fails to assure reliability whereas a TDMA-based protocol ensures reliability but fails to provide good adaptability. Therefore, we propose a protocol in which both reliability and energy efficiency are greatly improved with minimum adaptation time. In proposed protocol, a tree-based slot scheduling allocates one big slot to all nodes at each tree level and allows the nodes to share the allocated slot using CSMA. Data transmission is done using CSMA within the scope of an allocated sharable slot so that time constraint of data packets is secured. Several slot scheduling optimizations are taken into consideration so that the proposed approach saves a great deal of energy. We showed by simulation that the proposed approach is highly energy efficient for any real-time application in industrial WSNs