Issue link: https://resources.mouser.com/i/1520713
STMicroelectronics 2024 25 Interconnecting the Smart, Safe, Sustainable City Filippo Colaianni, Technical Marketing Manager, IoT & Connectivity, STMicroelectronics S mart cities aren't just dreamscapes. Today, a significant number of smart-city initiatives promise to manage energy, ease traffic flow, improve safety, track assets, and generally boost the quality of life for residents. These initiatives rely on a number of technological advances, especially communications infrastructure that links sensors and computing resources into coherent networks. Such networks can control, for example, street lighting, minimizing energy consumption and maintenance cost. They can link smart meters to energy distributors as well as consumers, so distributors of electricity, gas, and water can optimize them. This network can be used to monitor and track chemical and noise pollution. And they can interrogate stress and vibration sensors on critical infrastructure so city engineers will know continuously the health of their buildings, bridges, and roads. A challenge common to all these applications is connectivity. Many of the sensor systems required must have long unattended operating lives, often disconnected from both physical networks and the electrical grid. They must communicate over long distances with very low energy consumption and high reliability. Fortunately, most will not require high sustained data rates. So low-power, wide-area networks (WANs) can be an ideal solution. Of the low-power WAN architectures available today, Semtech's Long Range (LoRa) technology is perhaps the most promising. Based on chirped spread-spectrum modulation that spreads the transmitted signal across a wide frequency band, LoRa achieves ranges up to 3–5km in urban settings— and three times that for unobstructed line of sight—at very low energy per bit, with high data integrity and high resistance to interference. Recognizing that much of the data that moves around in a smart-city WAN will be sensitive, LoRA offers secure transmission with AES-128 encryption. LoRaWAN, an open standard developed by the LoRa Alliance, builds data-link and network layers on top of LoRa, creating a star-of-stars network topology. This topology allows for enormous networks with potentially millions of connections. A new gateway concept allows the topology to reach beyond urban cores into remote areas.