Constructing Minimal Maintenance Virtual Backbones over Low-Cost Wireless Networks

Virtual backbones are often used to provide a form of hierarchical infrastructure to ad-hoc and Wireless Sensor Networks, facilitating various demanding operations, such as routing. Virtual backbones are often constructed using Connected Dominating Sets (CDSs). The degree of mobility and chance of node failure present in such networks cause frequent network topology changes that require the maintenance and reconstruction of the virtual backbone, which can hinder the network. Therefore, the ability of the CDS to mitigate and avoid changes in topology should be a major concern during its construction. The approach proposed in this paper aims at minimizing the need for CDS maintenance, achieving its construction by selecting the most reliable nodes, when possible. Additionally, the construction of d-hop CDS is examined, as a way to restrict the resulting virtual backbone networks to reliable core infrastructure. The assessment of this approach is done through experiments, which are conducted on a low-cost wireless network deployed on a university campus testbed, which comprises 25 low-cost devices. Each node is assigned an appropriateness parameter used to describe the node’s reliability. The experiments focus on 1-CDS and 2-CDS construction, comparing the virtual backbones resulting from construction where the appropriateness parameter is taken into account, to those where it is not. The results indicate that utilizing the appropriateness parameter yields virtual backbones that are more reliable when 1-CDS is considered, whereas a small decrease in overall reliability is observed in 2-CDS construction.