d in Figure 14.20 as a function of the payload size, packet interarrival time, and ECL. The estimate is based on device A of Table 14.7 and a battery capacity of 5 W, in accordance with 3GPP assumptions. In good coverage conditions (ECL0), a battery lifetime target of 10 years is achieved for both payloads with up to 4-5 updates per day. In average coverage conditions (ECL1), the 20 B payload can be sent every 10h and still fulfill the battery lifetime target, while the larger packet Table 14.7 Measured power consumption for three commercial NB-loT devices [3]. Power state Device A Device B Device C Transmitting at 23 dBm 765 mW 731 mW 1030 mW Receiving 242 mW 215 mW 168 mW Connected DRX 29.1 mW 17.8 mW 17.7 mW Power saving mode (PSM) 11.1 uW 14.1 uW 24.3 uW 14.10 loT Solution Benchmarking Payload 20B Payload 200B Packet Interarrival Time (h) Figure 14.20 Estimated battery lifetime for device A as a function of packet interarrival time and coverage level based on [3]. may only be sent once every 18 h. In the most challenging coverage (ECL2), the battery lifetime target is very challenging due to the use of repetitions across all radio channels. If the 20 B payload is only updated every third day, it is achievable, and this may be a feasible solution, for example, for smart meters. Other event-driven use cases may also cope with this signaling limitation. The results show that LTE IoT technology has great battery life as long as the transmis- sion frequency remains relatively low and the coverage is good. If coverage extension is needed for NB-IoT, the battery life is reduced considerably. The further enhancements in Releases 14-15, for example, Early Data Transmission, will improve the battery lifetime, but for now it is important to match the traffic profile and the offered radio coverage with battery and latency targets, as major trade-offs are observed. Compared with Cat-M measurements [4], it is observed that PSM, C-DRX, and trans- mit power consumption levels are similar for Cat-M and NB-IoT for multimode de