One or more computer-readable storage media storing computer-readable instructions that when executed by a processor of a computer cause the computer to perform a method, comprising: communicating a location to a radio white space database, which is a database of databases that maps locations to databases; obtaining, from the radio white space database, information about first and second radio white space databases (104, 104), wherein the first radio white space database (104) covers a first geographic region (106) and the second radio white space database (104) covers a second adjacent geographic region (106); supplying (312, 318) the location to the first and second radio white space databases (104, 104); receiving, from the first radio white space database (104), a first set of radio white space frequencies and associated first constraints for the location, wherein the first constraints comprise first power and first transmission time constraints; receiving, from the second radio white space database (104), a second set of radio white space frequencies and associated second constraints for the location, wherein the second constraints comprise second power and second transmission time constraints; determining a common radio white space frequency that is common to both the first and second sets of radio white space frequencies; determining the lower power constraint of the first and second power constraints and the lower transmission time constraint of the first and second transmission time constraints, and, at the location, communicating data over the determined common radio white space frequency in accordance with the lower power constraint and the lower transmission time constraint. communicating a location to a radio white space database, which is a database of databases that maps locations to databases; obtaining, from the radio white space database, information about first and second radio white space databases (104, 104), wherein the first radio white space database (104) covers a first geographic region (106) and the second radio white space database (104) covers a second adjacent geographic region (106); supplying (312, 318) the location to the first and second radio white space databases (104, 104); receiving, from the first radio white space database (104), a first set of radio white space frequencies and associated first constraints for the location, wherein the first constraints comprise first power and first transmission time constraints; receiving, from the second radio white space database (104), a second set of radio white space frequencies and associated second constraints for the location, wherein the second constraints comprise second power and second transmission time constraints; determining a common radio white space frequency that is common to both the first and second sets of radio white space frequencies; determining the lower power constraint of the first and second power constraints and the lower transmission time constraint of the first and second transmission time constraints, and, at the location, communicating data over the determined common radio white space frequency in accordance with the lower power constraint and the lower transmission time constraint.