Class-Based Data Reporting Scheme in Heterogeneous Wireless Sensor Networks

Data reporting strategy in heterogeneous wireless sensor networks can be differentiated based on task-specific requirements. In this paper, we propose a novel two-phase data reporting (TDR) scheme that supports class-based QoS to sensor nodes in different priority classes. In the first phase, time slots are divided into separate data reporting round defined for each class, while in the second phase, the sensor nodes in the same class are scheduled to particular time slots depending on the given number of slots calculated in the first phase. In TDR, sensor nodes compete with other nodes in the same class only, while nodes in different classes have differentiated channel access opportunity. TDR is performed in a single-hop cluster-based topology, and a cluster head acts as a node assignment manager (NAM). Sensor nodes wake up for their scheduled time slots; otherwise, they go into sleep mode to save energy. TDR supports both schedule- based and contention-based channel access mechanisms and is scalable due to its distributed nature.