An apparatus comprising one or more processors, and one or more memories including computer program code, the one or more memories and the computer program code configured to, with the one or more processors, cause the apparatus at least to: control a base station to form an emulated long term evolution, LTE, fake cell such that tracking area code and physical cell identity of the emulated LTE fake cell are unused by real neighbouring LTE cells, and radio frequency power level of the emulated LTE fake cell within the emulated LTE fake cell is higher than the radio frequency power levels of the real neighbouring LTE cells within the emulated LTE fake cell; control the base station to receive a connection request from a subscriber terminal residing in the emulated LTE fake cell as a result of the subscriber terminal detecting it has moved to a new tracking area of the base station fulfilling the cell selection criteria in idle mode on the basis of the received emulated LTE fake cell, whereupon, in the ensuing exchange of messages, the base station is controlled to receive an international mobile subscriber identity from the subscriber terminal; characterized in that the one or more memories and the computer program code are further configured to, with the one or more processors, cause the apparatus to: control the base station to form the emulated LTE fake cell such that the frequency band of the emulated LTE fake cell is narrower than the full channel bandwidth employed by the real neighbouring LTE cells; control a measurement transceiver to obtain network information of the real neighbouring LTE cells; and select the tracking area code and the physical cell identity of the emulated LTE fake cell on the basis of the obtained network information of the real neighbouring LTE cells. control a base station to form an emulated long term evolution, LTE, fake cell such that tracking area code and physical cell identity of the emulated LTE fake cell are unused by real neighbouring LTE cells, and radio frequency power level of the emulated LTE fake cell within the emulated LTE fake cell is higher than the radio frequency power levels of the real neighbouring LTE cells within the emulated LTE fake cell; control the base station to receive a connection request from a subscriber terminal residing in the emulated LTE fake cell as a result of the subscriber terminal detecting it has moved to a new tracking area of the base station fulfilling the cell selection criteria in idle mode on the basis of the received emulated LTE fake cell, whereupon, in the ensuing exchange of messages, the base station is controlled to receive an international mobile subscriber identity from the subscriber terminal; characterized in that the one or more memories and the computer program code are further configured to, with the one or more processors, cause the apparatus to: control the base station to form the emulated LTE fake cell such that the frequency band of the emulated LTE fake cell is narrower than the full channel bandwidth employed by the real neighbouring LTE cells; control a measurement transceiver to obtain network information of the real neighbouring LTE cells; and select the tracking area code and the physical cell identity of the emulated LTE fake cell on the basis of the obtained network information of the real neighbouring LTE cells. control the base station to form the emulated LTE fake cell such that the frequency band of the emulated LTE fake cell is narrower than the full channel bandwidth employed by the real neighbouring LTE cells; control a measurement transceiver to obtain network information of the real neighbouring LTE cells; and select the tracking area code and the physical cell identity of the emulated LTE fake cell on the basis of the obtained network information of the real neighbouring LTE cells.