An apparatus comprising: a communication interface for communicating with a radio communication unit that is configured to perform radio communications within a mobile telecommunication network; a radio-physical detector for obtaining billing related information from the radio communication unit; and a trusted platform module configured to: receive billing related information from the radio-physical detector; cause the apparatus to send to the mobile telecommunication network the billing related information; the apparatus further comprising a mobile communication device configured to communicate through the mobile telecommunication network; wherein the radio-physical detector is configured to produce an indication of operation of a base station from which the mobile communication device receives radio signals and the billing related information comprises the indication of the operation of the base station; characterized in that : the base station is privately owned and/or located in private premises; the trusted platform module is further configured to: obtain a challenge known by the mobile telecommunication network; attest the billing related information using the challenge; and cause the apparatus to send to the mobile telecommunication network the billing related information as attested billing related information; and in that the billing related information comprises cell range. a communication interface for communicating with a radio communication unit that is configured to perform radio communications within a mobile telecommunication network; a radio-physical detector for obtaining billing related information from the radio communication unit; and a trusted platform module configured to: receive billing related information from the radio-physical detector; cause the apparatus to send to the mobile telecommunication network the billing related information; receive billing related information from the radio-physical detector; cause the apparatus to send to the mobile telecommunication network the billing related information; the apparatus further comprising a mobile communication device configured to communicate through the mobile telecommunication network; wherein the radio-physical detector is configured to produce an indication of operation of a base station from which the mobile communication device receives radio signals and the billing related information comprises the indication of the operation of the base station; characterized in that : the base station is privately owned and/or located in private premises; the trusted platform module is further configured to: obtain a challenge known by the mobile telecommunication network; attest the billing related information using the challenge; and cause the apparatus to send to the mobile telecommunication network the billing related information as attested billing related information; and in that the billing related information comprises cell range. the base station is privately owned and/or located in private premises; the trusted platform module is further configured to: obtain a challenge known by the mobile telecommunication network; attest the billing related information using the challenge; and cause the apparatus to send to the mobile telecommunication network the billing related information as attested billing related information; obtain a challenge known by the mobile telecommunication network; attest the billing related information using the challenge; and cause the apparatus to send to the mobile telecommunication network the billing related information as attested billing related information; and in that the billing related information comprises cell range. <EOS>