# Smart City Pilot Projects Using LoRa and IEEE802.15.4 Technologies
###### Abstract  
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. smart city; Internet of Things; testbed; LoRa; IEEE 802.15.4; measurements 181118610.3390/s18041118610.390/s18041118610. governance. The expected reward of such a process is an inclusive environment where, thanks to innovative technical solutions, citizens experience healthy, safer and more efficient conditions. Turning this vision into reality requires the integration of urban infrastructures, citizens and governance in a comprehensive and holistic perspective, which envisions the different components of the urban system as a unitary living body. In this biologic metaphor, ICTs play the role of the nervous system, connecting the different parts (infrastructures, people, governance) and providing the computational capability (i.e., the brain) for data analysis, features extraction and decision-making support. The Internet of Things (IoT) paradigm represents the core of this scenario, as plenty of connected devices will operate in order to sense the physical world as well as to adapt the context to changing circumstances. In most cases, connectivity will be ensured by wireless networks, as they enable the exchange of information with a flexible and low-cost deployment. In this regard, a heterogeneous communication technology and different network architectures can be adopted, depending on the characteristics of the service to be implemented (e.g., low bit rate or high bit rate), operational constraints (e.g., availability of an external power source), coverage (e.g., long-range or low-range links), etc. Mesh networks and short-range communication technologies, suitably integrated with cellular networks, are preferable, for instance, where end-to-end communications are not possible owing to power limitations and/or propagation obstacles. In this case, hop-by-hop communications from device to device can be exploited to convey information from the control center to the edge of the network, and backward. In this respect, different technologies can be adopted, such as IEEE 802.11s [3] and IEEE 802.15.4 [4]. The former is an amendment to the classic IEEE 802.11 standard (the so-called WiFi), introducing mesh networking and targeting bandwidth demanding services in scenarios with no energy consumption constraints. In contrast, IEEE 802.15.4 (which is the basis for ZigBee [5], ISA100.11a [6] and WirelessHART [7]) targets low bit rate communications among nearby devices with low energy consumption. Star networks and long-range communication technologies are preferred, instead, when direct and reliable links between the central hub and all nodes deployed in its coverage region are available.