An adaptive TDMA slot assignment protocol in ad hoc sensor networks

Due to its ability to provide collision-free packet transmission regardless of the traffic load, TDMA (Time Division Multiple Access) has been applied in ad hoc sensor networks. We have previously proposed a TDMA slot assignment protocol that utilizes the channel bandwidth effectively in ad hoc sensor networks. However, in this protocol, the channel bandwidth cannot be fully utilized because the frame length across the whole network tends to increase. In this paper, we extend this protocol to further improve channel utilization. The extended protocol prevents the excessive increase of unassigned slots by minimizing each node's frame length. Furthermore, we verify the effectiveness of our proposed protocols by simulation experiments. The results show that our extended protocol improves channel utilization dramatically in comparison with our previous protocol.