Location of an electronic device is determined using signals received from a first set of reference radios. The first set of reference radios include at least one secondary reference radio, each secondary reference radio established as a secondary reference radio by registering a corresponding location with a server. The corresponding location of the secondary reference radio is determined as a function of signals received by the secondary reference radio from a second set of reference radios. The second set of reference radios include radios qualified as reference radios in a database of primary se reference radios and secondary reference radios, each primary reference radio being a fixed-location radio device.