The present invention relates to radio communication in a cellular network and in particular to the sharing of a frequency spectrum with another network. The object is to enable robust communication in the shared band. The solution is to allocate a third band for communication in a cell. A L1/L2 control channel may be transmitted in the third band only, whereas data can be transmitted in the shared band. The L1/L2 control channel support the data communication in the shared band. The invention relates to a method and a radio base station.