A method for configuration of radio interface based synchronisation comprises obtaining of hearability information and synchronisation ability information concerning a multitude of radio base stations. The hearability information comprises an identity of the radio base station, and experienced signal quality from and identities of other radio base stations. The synchronisation ability information comprises information about a quality of synchronisation obtainable by the radio base station. A radio interface based synchronisation configuration is created in dependence of the obtained information. The radio interface based synchronisation configuration comprises definitions of synchronisation links, which radio base stations are recommended to use for synchronisation purposes. Data defining the radio interface based synchronisation configuration is provided for transmission to the respective radio base stations. Methods for radio interface based synchronisation and for planning radio interface based synchronisation, as well as arrangements and software for performing the methods are also presented.