A spectrum Sharing Controller comprises: an interface to a sharable spectrum, wherein the sharable spectrum is assigned to a first hierarchy level; a processor configured to enable a first entity for accessing at least part of the sharable spectrum on the first hierarchy level, wherein the processor is configured to assign a second hierarchy level to the at least part of the sharable spectrum accessible to the first entity, and wherein the processor is configured to enable a second entity for accessing at least part of the sharable spectrum on the second hierarchy level.