Patent ID: 8140018

Claim:
An interference mitigation method for use in a wireless communication system formed by a plurality of radio access networks, each radio access network having a network manager arranged for communication with a plurality of nodes associated with the network manager, and each radio access network having a frequency spectrum divisible into a plurality of sub-channels used for wireless communication by the nodes, said frequency spectrum at least partly overlapping with the frequency spectrum of one or more of the other radio access networks; the method comprising the steps of: the network manager of each radio access network performing a spectrum assignment process for allocation of sub-channels to its nodes; the nodes of each radio access network performing wireless communication using their allocated sub-channels; the network manager of one radio access network receiving, from its associated nodes, data indicative of an actual level of interference being experienced by the nodes, said interference arising either internally within the radio access network or externally from the other radio access networks; the network manager of said one radio access network comparing said actual level of interference with an estimated level of interference arising internally within the radio access network to determine whether there is a need for coordination with another network manager to reduce interference arising externally, and if so: the network manager of said one radio access network notifying this need to the network manager of at least one of the other radio access networks; and the network manager of said other radio access network performing again the spectrum assignment process to its associated nodes to reduce the level of interference being experienced by the nodes of said one radio access network.