Study Of Medium Access Control Technology In Wireless Sensor Networks

Energy management in Medium Access Control (MAC) technology is hot discussed issues in communication mechanism of wireless sensor networks. In this paper, this problem is addressed and a novel energy-efficient medium access control protocol- TDMA Based Energy Aware (TBEA) for wireless sensor networks is presented. TBEA is based on the concept of grouping, which utilizes TDMA in inner-group communication and FDMA-TDMA plus random backoff in inter-group communication. Meanwhile, it uses the concept of periodic listen and sleep in order to decrease energy wastage due to idle listening. Motivated by the fact that it is very difficult to maintain synchronization in each node, a header node is used in each group to make sure that nodes, which belong to the same group, adjust their time according to the header node. Accordingly, a node is permitted to transmit only in its own allocated slot. Furthermore, a header node can launch an election to vote for a new header in order to save its extra energy consumption. Simulation results on OPNET10.5 Modeler explicitly show the energy gain in performance. At last, in order to demonstrate the effectiveness and measure the performance of our MAC protocol, we evaluate our implementation of TBEA over a testbed wireless sensor node, developed by ourselves. The experiment results demonstrate that the transplanted protocol can work effectively and reliably on the sample wireless sensor node.