  Several protocol efficiency metrics (e.g., scalability, search success rate,
routing reachability and stability) depend on the capability of preserving
structure even over the churn caused by the ad-hoc nodes joining or leaving the
network. Preserving the structure becomes more prohibitive due to the
distributed and potentially uncooperative nature of such networks, as in the
peer-to-peer (P2P) networks. Thus, most practical solutions involve
unstructured approaches while attempting to maintain the structure at various
levels of protocol stack. The primary focus of this paper is to investigate
construction and maintenance of scale-free topologies in a distributed manner
without requiring global topology information at the time when nodes join or
leave. We consider the uncooperative behavior of peers by limiting the number
of neighbors to a pre-defined hard cutoff value (i.e., no peer is a major hub),
and the ad-hoc behavior of peers by rewiring the neighbors of nodes leaving the
network. We also investigate the effect of these hard cutoffs and rewiring of
ad-hoc nodes on the P2P search efficiency.
