In one embodiment, the unit share data rates for a plurality of mobile stations are determined with regard to two resource groups. A differentiation factor for each mobile station is formed from a ratio of its unit share data rates. The resulting differentiation factors are sorted and classified into two groups according to a proportional fair border determining function. A first one of the resource groups is allocated to the mobile stations corresponding to a first one of the differentiation factor groups. Similarly, a second one of the resource groups is allocated to the mobile stations corresponding to a remaining second one of the differentiation factor groups.