Medium Access Control with Token Approach in Wireless Sensor Network
Hybrid Medium Access Control (MAC) design in Wireless Sensor Network (WSN) brings a new research challenge nowadays. Hybrid MAC gives significant improvement in network performance especially in terms of energy efficiency and reliability of the network. Some of the data are sensitive to loss in the medium such as video data and data for emergency application. In MAC protocol, a contention access method which is Carrier Sense Multiple Access (CSMA) encounters collision problem when the number of nodes in the network increases. Meanwhile, the issue of slotted access which is Time Division Multiple Access (TDMA) is a strict synchronization problem. To avoid the weakness of both access methods, a hybrid MAC layer is proposed with unsynchronized TDMA, which is a token approach that calls the HMAC-TA.