Optimized TDMA multi-frequency scheduling access protocols for sensor networks

In order to eliminate the interferences between neighbors and reduce the delay, with the respect of the real time constraint, we focus our work on the multi-frequency scheduling access protocols. In this paper, we review the most multi-frequency MAC protocols which deploy more than one frequency to transmit data to neighbors. After that, we propose an optimized TDMA multi-frequency scheduling access contribution for sensor networks which is based on three phases. In the first phase, we assign frequencies based on parent node reception in communication tree structure. The reduction of the number of frequencies is provided, in phase two, based on the principle of the graph coloring. Finally, in the last phase, we reduce frequencies to the maximum number of allowed frequencies with TDMA (Time Division) clustering principle. Our results are compared with the other works and have showed that our strategy can remove more interference between neighbors, optimize communication delay and adapt with the maximum number of frequencies in WSN (Wireless Sensor Networks).