1. A method for determining network clusters in a fixed wireless backhaul network comprising a plurality of hubs and a plurality of Remote Backhaul Modules (RBM) having directional antenna, wherein each cluster comprises a hub serving a number of RBMs (hub-RBM cluster), comprising the steps of: for N hubs, each of the N hubs serving M RBMs, for a total number of NM RBMs, indexing each of the plurality of N hubs i and each of the plurality of NM RBMs j to define a plurality of all N×NM candidate hub-RBM pairs ij; for hub-RBM radio links ij between each respective hub-RBM pair ij, and for each candidate location k of each RBM j, obtaining an input link quality value LQV ijk ; ranking said link quality values LQV ijk of hub-RBM links ij for each candidate location k of each RBM j, and choosing a maximum value LQV ij of these link quality values, where LQV ij =max k LQV ijk , to obtain a two dimensional input LQV table of values LQV ij of size N×NM; reshaping the input LQV table into a LQV vector in a column-wise order and ranking link quality values LQV ij to provide a reordered LQV vector, by performing a ranking operation denoted by a permutation π, to reorder the link quality values LQV ij of the LQV vector from the highest to the lowest, and wherein the inverse permutation of π is denoted by π −1 , which maps the index of the reordered link quality values LQV ij to the index of the reshaped LQV vector, the LQV vector comprising two dimensions corresponding to a hub index (hub ID) and an RBM index (RBM ID) wherein: for the t th position in the reordered LQV vector, the RBM ID and hub ID are computed as RBM ⁢ ⁢ ID ⁡ ( t ) = mod ⁡ ( π - 1 ⁡ ( t ) - 1 NM ) + 1 hub ⁢ ⁢ ID ⁡ ( t ) = floor ( π - 1 ⁡ ( t ) - 1 NM ) + 1 identifying each hub-RBM cluster from the reordered LQV vector, comprising: from the highest to the lowest link quality values, identifying each hub-RBM cluster by excluding each RBM from being clustered more than once and by satisfying a maximum number of RBMs per cluster constraint.