A method performed in a cellular communication network for establishing that a first cell of said network is unable to receive uplink radio signals. The method comprises determining that no indicative radio message has been received from any radio device during a predetermined time period. In view of said determining, requesting a second cell, neighboring the first cell, to instruct at least one radio device, connected to said second cell and able to detect said first cell, to transmit a radio signal. The method may also comprise obtaining information about how to receive the radio signal. The method may also comprise determining that the radio signal was not successfully received by the first cell in accordance with the obtained information.