A communication technique for synchronizing a set of radio nodes is described. In this communication technique, the radio node arbitrates (e.g., using a precision time protocol or PTP) with the other radio nodes based on a selection technique to select a synchronization master in the set of radio nodes. This synchronization master may be selected to have a predefined performance based on a type of communication environment of the set of radio nodes. For example, the type of communication environment may include overlap between at least one of the radio nodes in the set of radio nodes and a macrocell in a cellular-telephone network, or may exclude overlap between the set of radio nodes and the macrocell. Moreover, the synchronization master may specify time, frequency, and phase synchronization for the set of radio nodes. Thus, when the synchronization master is different from the radio node, the radio node synchronizes with the synchronization master.