TB-MAC:A Novel MAC Protocol Based on Application Task in Wireless Sensor Networks

The sensor nodes in a WSN are considered as the sinks at different levels,and then the task model is developed by the semantic description of the WSN application,which serves as the basic unit employing by the nodes for data transferring and processing.Based on the task model,the hybrid scheduled TB-MAC(Task-based MAC)is put forward.The nodes compete with each other for the shared channel to reply the broadcasted by the cluster to request sub-task,and a variable slot length TDMA scheme is adopted to schedule the nodes selected by the cluster according to their answers to carry out sub-tasks so as to provide QoS guarantees.The redundancies among data of the nodes could be eliminated efficiently,leading to better network performance,because of the sub-task negotiation during the selection of the nodes.Simulation results demonstrate that TB-MAC achieves better performance in terms of energy and delay than the popular MAC protocols such as ECR-MAC,Z-MAC and S-MAC.