Radio communication resources are allocated in a cellular radio communication system having a plurality of user stations and network units by subdividing a frequency band that is sub-divided into a plurality of sub-carriers used for communication purposes. In several radio cells, one or more network units sub-divides(s) the frequency band into a number of sub-bands having one or more respective sub-carriers, sub-divide(s) the user stations into a number of groups and allocate(s) a sub-band for communication purposes to each group. The number of sub-bands differs for at least two radio cells.