HD-MAC: A Throughput Enhancing TDMA-Based Protocol in High Dynamic Environments

Distributed TDMA medium access protocol plays an important role in stabilizing the throughput under various network states. The major challenge of implementing such protocol lies in the difficulty of slot assignment. Previous works provide a variety of mechanisms to implement the collision-free slot assignment. However, when network topology changes frequently, existing approaches suffer from low throughput due to the waste of idle slots. In this paper, we propose a novel distributed TDMA protocol called HD-MAC to improve the throughput performance under high dynamic change of network topology. Specifically, we come up with a frame structure with fixed length and establish a network join principle regarding the slot assignment for the newly added node, which avoid the overhead of maintaining extra frame length information among nodes. In addition, we adopt a contention-based channel access mechanism for enhancing the utilization of the idle slots, thus increasing the overall throughput. Finally, simulation results are demonstrated to validate the effectiveness of HD-MAC.