A method in a radio resource allocator of a radio access network is disclosed. The network comprises at least one first layer and at least one second layer, the first layer is higher than the second layer; and the method in a first radio resource allocator of the first layer comprises: decides if a second radio resource allocator of the second layer in an autonomous mode or in a controlled mode for at least one portion of available radio resources; when the second radio resource allocator in the autonomous mode, allocates the at least one portion of available radio resources to the second radio resource allocator; when the second radio resource allocator in the controlled mode, allocates the at least one portion of available resources to radio resource users of the radio resource users of the second radio resource allocator and/or radio resource allocators of a third lower layer.