Method for monitoring and identifying radio coverage gaps of a public land mobile network (PLMN) comprising usage of stand alone signaling transfer points (SASTP) producing list of cells, the method comprising the capturing of an update location (UL) message in the case of logging in a mobile communication device into the network and a cancel location (CL) message in the case of leaving the network, whereas the update location (UL) message and the cancel location (CL) message comprise an information identifying the mobile communication device, particularly the international mobile subscriber indentity number (IMSI), comprising generation of provide subscriber info message, whereas the provide subscriber info response (PSI_Resp) message from last visited VLR comprise a cell identification (CeIl_ID) identifying the cell of the public land mobile network (PLMN) which was last used and/or in which the mobile communication device has left the network and further comprising the generation of a report message including the cell identification (CeII_ID).