Co-Existence Dynamic Channel Assignment (DCA) techniques for overlay macrocellular systems facilitate the coexistence of embedded autonomous underlay microcellular (e.g., indoor) systems. The Co-existence of the two systems without excessive mutual interference is achieved through statistical systematic exclusion of predefined subsets of the universal channel set from the dynamic assignment to the overlay macrocells. The sets of channels are made available to the underlay systems. The exclusion is done with minimal DCA performance degradation.