1. A method implemented in an apparatus for use in a wireless communication system, the method comprising: mapping, via the apparatus, a plurality of real resource identifiers of a plurality of channel resources of a channel tree to a plurality of corresponding virtual resource identifiers based on a prescribed scheme, wherein each of the plurality of channel resources is associated with a real resource identifier and a corresponding virtual resource identifier, and wherein the plurality of channel resources are mapped to a plurality of subcarriers in the wireless communication system, wherein the wireless communication system is based on OFDMA; and performing, via the apparatus, at least one operation related to resource allocation for at least one channel resource among the plurality of channel resources using at least one virtual resource identifier of the at least one channel resource.