A method and an arrangement for providing synchronisation information (e.g. for phase synchronisation) to an access node, e.g. a radio base station. A reference signal is received 300 from a synchronisation source node, wherein the reference signal comprises at least one timing reference. Receiving 300 the reference signal comprises receiving the reference signal by means of an antenna device associated with the synchronisation module. The received reference signal is processed 302 to form at least one synchronisation packet, wherein each one of the at least one synchronization packet comprises a respective one of the at least one timing reference. The at least one synchronisation packet is distributed 304 to the access node via a physical connection. By arranging a synchronization module in a building and processing reference signals received by an antenna means at the building to form synchronization signals, timing references comprised in the reference signals may be distributed via physical connections to access nodes to be utilised for phase synchronization. Thereby, access nodes, such as radio base stations, may be properly provided with phase synchronization information even they are located in indoor environments.