The invention relates to a network entity for managing communications of a plurality of communication devices within a communication network, a communication device of the plurality of communication devices being configured to transmit a multi-carrier communication signal comprising a plurality of sub-carriers, and to transmit an energy efficiency indicator indicating an energy efficiency specification of the communication device, the network entity comprising a communication interface being configured to receive the energy efficiency indicator over the communication network, and a processor being configured to determine a sub-carrier frequency spacing of the plurality of sub-carriers upon the basis of the energy efficiency indicator, and to generate a resource block indicator associated with the communication device, wherein the resource block indicator indicates the sub-carrier frequency spacing, wherein the communication interface is further configured to transmit the resource block indicator over the communication network to the communication device.