A distributed method and system are presented for determining the largest Signal-to-Interference-and-Noise Ratio (SINR) that can be achieved by a plurality of small wireless cells, such as femtocells or picocells, while satisfying a specified SINR value for multiple large cells, referred to as macrocells. The method also determines the minimum power levels at each of the femtocells that achieve the maximum SINR for the femtocells. The distributed synchronous algorithm executes all intensive computations independently, locally at each of the femtocells. The computations are synchronized in time and executed simultaneously at all cells where after each of the iterations information of interim power selections at the multiple cells is exchanged among the femtocells. Eventually, the computations converge to the maximum SINR value and the corresponding minimum-power solution.