A cluster oriented hybrid MAC with dual slots for wireless sensor networks

The CHMAC, a cluster oriented hybrid media access control (MAC) protocol, constructed using the carrier sense multiple access (CSMA)/ time division multiple access (TDMA) hybrid approach, is presented for event driven wireless sensor network applications. To improve the performance of throughput and the energy efficiency, especially the delay performance for urgent event, a channel access mechanism of two types of slots is presented. Slot assignment fitting for such kind of networks is adopted. Traffic characteristics are also utilized to control listening and sleeping and transmission power of sensor nodes elaborately. The results of the analysis and simulation show that the proposed CHMAC has good performance and exhibits good adaptability and robustness in different traffic conditions.