A method executed by a mobile terminal for operating in a downlink Orthogonal Frequency-Division Multiplexing, OFDM, resource space allocated by a cell, the method comprising: receiving a channel descriptor management message from the cell of a base station, the channel descriptor management message indicating to the mobile terminal the downlink OFDM resource space allocated by the cell, wherein the message comprises a format for a DL subframe, the DL subframe including an OFDM resource space, the message further providing a hierarchical definition for a plurality of sub-resource spaces within the OFDM resource space, each sub-resource space having an associated sub-resource space identifier and being individually allocatable, the plurality of sub-resource spaces comprising a definition of a first sub-resource space in a first layer of a hierarchy of layers of the OFDM resource space and a definition of a second sub-resource space in a second layer of the hierarchy of layers, where the second sub-resource space is positioned within the first sub-resource space, wherein the second layer of the hierarchy of layers has a plurality of channels with a channel size that is smaller than a channel size of the first layer of a hierarchy of layers, wherein each layer of the hierarchy of layers occupies the entirety of the OFDM resource space, and receiving the DL subframe from the cell of the base station, wherein the DL subframe comprises a respective sub-burst within at least one of the plurality of sub-resource spaces within the OFDM resource space corresponding to the mobile terminal, the DL subframe further comprising a downlink mapping component that includes information for the mobile terminal indicating where the respective sub-burst for the mobile terminal is located in the OFDM resource space. receiving a channel descriptor management message from the cell of a base station, the channel descriptor management message indicating to the mobile terminal the downlink OFDM resource space allocated by the cell, wherein the message comprises a format for a DL subframe, the DL subframe including an OFDM resource space, the message further providing a hierarchical definition for a plurality of sub-resource spaces within the OFDM resource space, each sub-resource space having an associated sub-resource space identifier and being individually allocatable, the plurality of sub-resource spaces comprising a definition of a first sub-resource space in a first layer of a hierarchy of layers of the OFDM resource space and a definition of a second sub-resource space in a second layer of the hierarchy of layers, where the second sub-resource space is positioned within the first sub-resource space, wherein the second layer of the hierarchy of layers has a plurality of channels with a channel size that is smaller than a channel size of the first layer of a hierarchy of layers, wherein each layer of the hierarchy of layers occupies the entirety of the OFDM resource space, and receiving the DL subframe from the cell of the base station, wherein the DL subframe comprises a respective sub-burst within at least one of the plurality of sub-resource spaces within the OFDM resource space corresponding to the mobile terminal, the DL subframe further comprising a downlink mapping component that includes information for the mobile terminal indicating where the respective sub-burst for the mobile terminal is located in the OFDM resource space.