Energy consumption profile of a battery-equipped ED during a normal cycle of remote control. Left-side panel: measured absorbed current during wake-up, keep-alive receive (RX), and transmit (TX) phases (transmission of ACK message is included). Right-side panel: battery lifetime versus the number of transmitted alarm messages per hour. Guard time of 50 ms uses the proposed drift error compensation for prediction of timing uncertainty; the case of guard time 150 ms does not implement any error compensation. Bottom panel: energy consumption parameters.