Methods and apparatus are disclosed for improving radio transmissions between a mobile device located inside an enclosed structure and an outside radio network. A relay or repeater is used to relay transmissions back and forth between the inside mobile device and the outside radio network. The transmission power of the relay/repeater used to transmit signals to the mobile device and that of the mobile device used to communicate with the relay/repeater can be dynamically adjusted in accordance with the penetration loss of the enclosed structure.