Gateway Placement Optimization in Wireless Mesh Networks with QoS Constraints, Bassam Aoun, Raouf Boutaba, Youssef Iraqi, Gary Kenward, in IEEE Journal on Selected Areas in Communications, Nov. 2006, Vol. 24, No. 11, pp. 2127-2136.
This paper computes the grouping of wireless mesh nodes around a cluster head in order to satisfy some constraints (mostly max number of hops for any node to reach the gateway). The algorithm is a recursive use of a gready Dominated Set algorithm (find the node with highest degree, remove this node and its neighbors, then repeat) to construct clusters of the desired size.
Actually, it seems that the iteration would yield clusters of size increasing geometrically (of the order 2^n after n iterations) so that the maximum diameter better be a power of two for the algorithm to work optimally.
Nonetheless, the idea is interesting, the algorithm relatively simple and the paper is very readable (despite using word instead of latex in the print-out I have; maybe the actual journal version looks better after the editing from the journal).