A Hybrid TDM-FDM MAC Protocol for Wireless Sensor Network Using Timestamp Self-Adjusting Synchronization Mechanism

According to the characteristic of high reliable and low power periodical data collection on a large scale metallurgical industry wireless sensor network(WSN), we present a hybrid TDMA-FDMA MAC protocol ,this protocol depends on a cluster-based hierarchical topology and uses a synchronization mechanism with dynamic time-stamp adjusting. In this protocol, we use a one-off time-slot allocation TDMA based on broadcasting in initial and adopt dynamic timestamp adjusting time synchronization technology for each node within a cluster, which could effectively decrease the data collision caused by random competition and reduce the synchronization cost in traditional TDMA protocol. And we adopt FDMA protocol between the clusters to order to deploy a large-scale WSN with little delay increase. The experiment result has proved that this protocol could prolong the networks life-time by about 14% compared with the traditional TDMA protocol, and it also demonstrates that the protocol could guarantee the requirement of energy efficiency, accuracy, robust and reliability in metallurgical industry. The protocol could also be applied to other WSN systems.