Abstract: An apparatus for frequency planning for a cellular communication system comprises a receiver (201) receiving measurement reports from remote stations. An interference processor (203) determines, for each of a plurality of cells, a neighbour cell interference relationship between at least a first and a second neighbour cell for the cell in response to measurement reports from remote stations served by the cell. The neighbour cell interference relationship is indicative of interference from the first to the second neighbour cell. The first and second cells are both neighbours of an intermediate cell but are not (necessarily) neighbours of each other. A frequency planner (205) determines a frequency plan in response to the neighbour cell interference relationships. The invention may allow the interference impact on neighbours of neighbour cells to be estimated and taken into account in the frequency plan thereby leading to improved frequency plans and performance of the cellular communication system.