Clustering is a very popular network structuring technique which mainly
addresses the issue of scalability in large scale Wireless Sensor Networks.
Additionally, it has been shown to improve the energy efficiency and prolong
the life of the network. The suggested protocols mostly base their clustering
criteria on some grouping attribute(s) of the nodes. One important attribute
that is largely ignored by most of the existing multi-hop clustering protocols
is the reliability of the communication links between the nodes.