On the tree formation of Wireless Sensor Networks

Distributed Address Assignment Mechanism (DAAM) has been suggested to be used in the ZigBee tree topology for its simplicity and efficiency. However, its topological parameter restricts the shape and extent of the networks, and results in orphan problem and poor coverage. Three alternatives are proposed and evaluated in this article. 2-layer DAAM (2DAAM) uses hierarchical scheme, which divides the address scheme into two layers, the master-layer, and the slave-layer. Each layer runs a separate DAAM scheme with its own parameters. Location- Aware DAAM (LDAAM) assume each device knows its own coordinate and that information is used in the child selection during the tree formation process. Finally, RSSI-DAAM (RDAAM) uses the information of RSSI in the construction of tree. Simulation results show that 2DAAM, LDAAM and RDAAM improve network coverage and relief the orphan problem without additional storage and routing cost.