  We propose an algorithm that builds and maintains clusters over a network
subject to mobility. This algorithm is fully decentralized and makes all the
different clusters grow concurrently. The algorithm uses circulating tokens
that collect data and move according to a random walk traversal scheme. Their
task consists in (i) creating a cluster with the nodes it discovers and (ii)
managing the cluster expansion; all decisions affecting the cluster are taken
only by a node that owns the token. The size of each cluster is maintained
higher than $m$ nodes ($m$ is a parameter of the algorithm). The obtained
clustering is locally optimal in the sense that, with only a local view of each
clusters, it computes the largest possible number of clusters (\emph{ie} the
sizes of the clusters are as close to $m$ as possible). This algorithm is
designed as a decentralized control algorithm for large scale networks and is
mobility-adaptive: after a series of topological changes, the algorithm
converges to a clustering. This recomputation only affects nodes in clusters in
which topological changes happened, and in adjacent clusters.
