Effects of Traffic Characteristics on Energy Consumption of IoT End Devices in Smart City

The rapid urbanisation in many parts of the world in the last few decades has intensified the challenges of urban living. Internet of Things (IoT) can be leveraged as a tool for transformation to provide technology-assisted city development and management. However, given that many of the nodes in smart cities are constrained devices, part of the medium-long term challenges is how to sustain the real-time monitoring capabilities of the city without disrupting services. This paper investigates the effects of data traffic characteristics on the active life of constrained devices in smart cities. The access network model employs two leading low-power wide area network (LP-WAN) technologies; long range wide area network (LoRaWAN) and Sigfox specifications in a star topology. The results show that in Europe, for lightweight applications such as smart street lighting that sends small payloads once a day, Sigfox and LoRaWAN can provide device lives of about 5.82 years and 13.25 years respectively. On the other hand, for intense applications such as smart bus stops, using payload of 12 bytes, if the number of messages sent per day is increased from 1 to 140, Sigfox device life reduces from 4.43 years to 0.8 years while that of that of LoRaWAN reduces from 13.1 years to 10.48 years.