Possible power-saving gains by dividing a cell into tiers of smaller cells

Possible power-saving gains of cellular networks by dividing a cell into tiers of smaller cells, i.e. micro and pico cells is studied. A power-saving gain formulation is derived which is a function of tiers. It is suggested that shrinking the cell size should be implemented when the path loss is large enough to compensate for the extra power required to convey information on the backhaul and to beat the interference among smaller cells.