Abstract
In ZigBee networks, the classical Tree Routing  algorithm only utilizes the father-child relationship between nodes to establish routes, thus the path usually may not be optimal, which leads to some extra overhead. To address this problem, in this paper, we propose an improved Tree Routing algorithm which utilizes the information of neighbors within two hops. Concretely, our proposed algorithm  allows nodes to use the distributed address assignment mechanism (DAAM) to calculate their depth, and decide whether to adopt the algorithm based on two hop neighbors or Tree Routing by the comparison of the overhead from the next hop to destination node. Meanwhile, routing nodes broadcast beacon messages with local neighbor information periodically, so a node can obtain the 2-hop neighbor information easily. Simulation results show that our algorithm improves the success ratio of packet delivery, and reduces 30% of the end to end delay, and at least 30% of the average number of hops compared to the Tree Rounting algorithm.