A method for supporting a network listening in a wireless communication system, the system comprising a user equipment, UE, and a plurality of base stations providing service to their respective cells, the method comprising: receiving, by the UE, a subframe configuration used for the network listening; monitoring a plurality of subframes indicated by the received subframe configuration, wherein the plurality of subframes is used for receiving a radio interface based synchronization-reference signal, RIBS-RS, for a synchronization among the base stations; receiving, by the UE, the RIBS-RS for the synchronization, wherein the RIBS-RS for the synchronization is received in a subframe configured for the network listening among the plurality of subframes, wherein a base station of the plurality of base stations mutes signals of the subframe except for the RIBS-RS for the synchronization, wherein the base station transmits the RIBS-RS only in a physical downlink shared channel, PDSCH, region of the plurality of subframes, and the base station mutes the signals in the PDSCH region of the plurality of subframes, and wherein the base station mutes the signals according to a muting pattern, which is configured and triggered by downlink control information, DCI; performing, by the UE, synchronization to a cell based on the RIBS-RS for the synchronization, wherein the base stations of cells with a higher stratum level increase their power or increase a density of the RIBS-RS in a subframe, wherein the base stations configure an orthogonal transmission of the RIBS-RS among cells with a same stratum level, wherein the number of subframes allocated increases proportional to the stratum level or proportional to previous stratum level in every stratum level; and receiving or-transmitting data, by the UE, at a timing based on the synchronization to the cell. receiving, by the UE, a subframe configuration used for the network listening; monitoring a plurality of subframes indicated by the received subframe configuration, wherein the plurality of subframes is used for receiving a radio interface based synchronization-reference signal, RIBS-RS, for a synchronization among the base stations; receiving, by the UE, the RIBS-RS for the synchronization, wherein the RIBS-RS for the synchronization is received in a subframe configured for the network listening among the plurality of subframes, wherein a base station of the plurality of base stations mutes signals of the subframe except for the RIBS-RS for the synchronization, wherein the base station transmits the RIBS-RS only in a physical downlink shared channel, PDSCH, region of the plurality of subframes, and the base station mutes the signals in the PDSCH region of the plurality of subframes, and wherein the base station mutes the signals according to a muting pattern, which is configured and triggered by downlink control information, DCI; performing, by the UE, synchronization to a cell based on the RIBS-RS for the synchronization, wherein the base stations of cells with a higher stratum level increase their power or increase a density of the RIBS-RS in a subframe, wherein the base stations configure an orthogonal transmission of the RIBS-RS among cells with a same stratum level, wherein the number of subframes allocated increases proportional to the stratum level or proportional to previous stratum level in every stratum level; and receiving or-transmitting data, by the UE, at a timing based on the synchronization to the cell.