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

Smart city pilot projects using LoRa and IEEE802.15.4 technologies

Information and Communication Technologies (ICTs), through wireless communications and the Internet of Things (IoT) paradigm, are the enabling keys for transforming traditional cities into smart cities, since they provide the core infrastructure behind public utilities and services. However, to be effective, IoT-based services could require different technologies and network topologies, even when addressing the same urban scenario. In this paper, we highlight this aspect and present two smart city testbeds developed in Italy. The first one concerns a smart infrastructure for public lighting and relies on a heterogeneous network using the IEEE 802.15.4 short-range communication technology, whereas the second one addresses smart-building applications and is based on the LoRa low-rate, long-range communication technology. The smart lighting scenario is discussed providing the technical details and the economic benefits of a large-scale (around 3000 light poles) flexible and modular implementation of a public lighting infrastructure, while the smart-building testbed is investigated, through measurement campaigns and simulations, assessing the coverage and the performance of the LoRa technology in a real urban scenario. Results show that a proper parameter setting is needed to cover large urban areas while maintaining the airtime sufficiently low to keep packet losses at satisfactory levels