LAUSR

There are presently many applications where a non-uniform distribution of devices needs to be established for Bluetooth scatternets. Under the scenario of one dense zone and multiple sparse zones, the dense area has a high probability of generating a single-hop scenario since most devices are within radio range, whereas most devices are out of radio range under the multi-hop scenario in other sparse areas. Thus, both situations have to be considered in the formation of an algorithm design for most real-life situations. This work proposes a reliable formation protocol, called Dual-Ring Tree, for hybrid single-hop/ multi-hop instances. To benefit from the advantages of the hybrid scenarios, a dual-ring subnet is presented as a single-hop solution for dense areas, while a tree-shaped subnet is designed as a multi-hop solution for sparse areas. To the best of the authors' knowledge, this is the first time such an algorithm has been designed to deal with both single-hop and multi-hop scenarios. The computer simulation results suggest that the reliable Dual- Ring Tree outperforms conventional BlueHRT in terms of routing efficiency and network reliability for Bluetooth multi-hop networks.