An Autonomous Multicast-tree Creation Algorithm for Wireless Sensor Networks

In this paper, we propose an algorithm to realize a power-aware network topology in wireless sensor networks. The algorithm creates a multicast tree connecting all sensor nodes. In the multicast tree, a sink node should be a root node, and all the data sensed in the sensor nodes are transferred to the sink node using the tree connection. The relay nodes aggregate the received data, and transfer the aggregated data to the sink at an appropriate timing so as to avoid packet collisions. To do this, all the sensor nodes are grouped in clusters. Here, each cluster has a head node, which is automatically selected from among the nodes in the cluster. In addition, our algorithm has an autonomous mechanism that can change the cluster head dynamically based on the remaining energy of each sensor node and the communication quality among the sensor nodes, which are obtained by periodical information exchange between the sensor nodes. This mechanism contributes to extending the lifetime of the sensor network. After describing the algorithm, some experimental results are shown to prove its effectiveness and robustness.