The coexistence of a plurality of different wireless networks that concurrently operate in a common geographic region is optimized. A query is received from a wireless node requesting advice on specific portions of a radio frequency spectrum to use. A spectrum recommendation procedure is then run to generate advice on recommended portions of the radio frequency spectrum for the wireless node to use in order to minimize one or more of interference in the spectrum, or noise in the spectrum, or contention in the spectrum. A recommendation reply is then sent to the wireless node which includes information specifying the recommended portions of the radio frequency spectrum for the wireless node to use in order to minimize one or more of interference in the spectrum, or noise in the spectrum, or contention in the spectrum.