V.Krishnamurthy and E.Sazonov, Vo.4 No. 3 of International Journal Of Sensor Networks, 2008.
The IEEE 802.15.4 and Zigbee are protocols aimed at low-duty and low-power wireless sensor networks. Continuously monitoring applications such as applications of structural health monitoring could benefit from low power consumption of the IEEE 802.15.4 radio chips. However, existing implementation of IEEE 802.15.4 has limited applicability to 'proactive', high-traffic monitoring sensor networks with constant data streams. In this paper, a Time Division Multiple Access (TDMA) scheduler was designed and implemented to resolve issues with collisions and interference, bandwidth usage and delivery of low latency data in a healthy network and to significantly minimise power consumption by sensor nodes. These improvements maintained compatibility with non-TDMA aware nodes. This scheduler was simulated using Network Simulator-2 for different network scenarios that show a remarkable improvement in the network throughput. The proposed mechanism was also successfully tested and implemented in Wireless Intelligent Sensor and Actuator Network (WISAN).