  Internet of Things (IoT) is one of the main features in 5G. Low-power
wide-area networking (LPWAN) has attracted enormous research interests to
enable large scale deployment of IoT, with the design objectives of low cost,
wide coverage area, as well as low power consumption. In particular, long
battery lifetime is essential since many of the IoT devices will be deployed in
hard-to-access locations. Prediction of the battery lifetime depends on the
accurate modelling of energy consumption. This paper presents a comprehensive
power consumption model for battery lifetime estimation, which is based on User
Equipment(UE) states and procedures, for two cellular IoT technologies:
Narrowband Internet of Things (NB-IoT) and Long Term Evolution for Machines
(LTE-M). A measurement testbed has been setup and the proposed model has been
tested and validated via extensive measurements under various traffic patterns
and network scenarios, achieving the modelling inaccuracy within5%. The
measurement results show that the battery lifetime of an IoT device can reach
up to 10 years as required by 3GPP, with proper configuration of the traffic
profile, the coverage scenario, as well as the network configuration
parameters.
