1. A method for optimization of the configuration of a hierarchical network, the network having m hierarchy levels, where m is at least 3, comprising a first hierarchy level (LEVEL(j−1)), a second hierarchy level (LEVEL(j)) next below the first hierarchy level, and a third hierarchy level (LEVEL(j&plus;1)) next below the second hierarchy level, each hierarchy level comprising nodes (RNC's, HUB's, RBS's) each of which, in hierarchy levels (e.g. (LEVEL(j−1), LEVEL(j)) other than the lowest (e.g. (LEVEL(j&plus;1)), receives traffic from a cluster of nodes (HUB's, RBS's) of the hierarchy level (e.g. (LEVEL(j), LEVEL(j&plus;1)) next below, setting and/or generating an initial arrangement of nodes (RNC's, HUB's, RBS's) in each of the hierarchy levels (e.g. (LEVEL(j−1), LEVEL(j), LEVEL(j&plus;1)) and, in each of the hierarchy levels other than the highest (e.g. LEVEL (j−1)), allocating respective initial clusters of nodes (HUB's, RBS's) of that level to the nodes (RNC's, HUB's) of the next higher hierarchy level (LEVEL(j−1), (LEVEL(j)), iteratively repeating the following steps (a) and (b): (a) for each node (RNC) of the first hierarchy level (LEVEL(j−1)), identifying an optimized number of, and dispositions of, nodes (HUB's) of the second hierarchy level (LEVEL(j)), for those nodes (RBS's) of the third hierarchy level (LEVEL(j&plus;1)) which, immediately prior to this iteration of step (a), were allocated to the nodes (HUB's) of the second hierarchy level (LEVEL(j)) allocated to the node (RNC) concerned of the first hierarchy level (LEVEL(j−1)), and for each node (RNC) of the first hierarchy level (LEVEL (j−1)), reallocating said those nodes (RBS's) of the third hierarchy level (LEVEL(j&plus;1) to the nodes (HUB's) of the second hierarchy level (LEVEL(j)) identified in this iteration of step (a), (b) for the nodes (HUB's) of the second hierarchy (LEVEL(j)) identified in step (a), identifying an optimized number of, and dispositions of, the nodes (RNC) of the first hierarchy level (LEVEL(j−1)), and reallocating the nodes (HUB's) of the second hierarchy level (LEVEL(j)) identified instep (a) to the nodes (RNC's) of the first hierarchy level (LEVEL(j−1)) determined in this iteration of step (b), until steps (a) and (b) result in no changes in number, disposition and allocation of nodes (RNC's, HUB's, RBS's) over a predetermined number of iterations of those steps.