By Marc Pegulu, vice president of IoT product marketing and strategy for Semtech’s Wireless and Sensing Products Group
Smart cities are not just about technology, sensor networks or artificial intelligence. Smart buildings have to make life easier for the people that use them in a sustainable way. This is very different from a pure IT enterprise approach of bits and bytes, and the requirements of people are even more important to address.
One of the key technologies for smart cities is wireless low power wide area networks (LPWAN). This is a key technology for the Internet of Things (IoT) that allows low power sensors to be deployed quickly and easily in smart buildings where data needs to be collected in order to be of assistance to people.
This can be monitoring how many people are in a room, or walking through a building, the temperature, the carbon dioxide levels, or any kind of data that is needed to help people feel more comfortable. This data needs to be collected and collated but most of all it needs to be acted on to enhance the quality of life of the people in the smart city. This requires a combination of the right sensor, wireless network technology and data management tools.
Wireless LPWAN protocols such as LoRaWAN® enable low power sensors that can run for years or even decades from a coin cell battery, avoiding costly battery replacement cycles. Using a wireless, battery-powered system allows the sensors to be placed exactly where they are needed, and scales across large buildings and across the city itself.
Semtech’s LoRa® technology behind LoRaWAN standard provides reliable wireless links in unlicensed frequency bands below 1GHz. These sub-Ghz bands allow long distance, low power operation while the protocol provides a robust, reliable link. This combination means wireless sensors can be powered by a single coin cell for many years.
The sensors connect to a gateway that collects the data and delivers it into the wider network, the Internet of Things. These gateways are powered by mains or Power over Ethernet, and link back to an operator’s software, either on the premises or in the cloud.
The proliferation of sensors, and the IoT connection, can also help the sustainability of smart buildings and the wider smart city. Sensors to monitor leaks can reduce the consumption of water and flag problems before they become an issue, while sensors in the local power grid can similarly identify problems before they cause an outage.
Integrating these low-cost sensors into logistics systems provide information, convenience and sustainability across the smart city. Equipment of all kinds can be tagged and tracked, making sure it is in the right place at the right time, making the best use of resources. Goods can be shipped in the optimum routes depending on the delivery times, reducing CO2 footprint and pollution. Customers can track the packages to eliminate unnecessary or wasted journeys.
This is enabled by the low power of the communications link. Deploying thousands of sensor nodes around a building would require a regular routine of replacing batteries at considerable cost. Extending the battery life by years, or even a decade, actually aligns the battery life with the lifetime of the sensor itself, and both would be replaced at the same time.
The low power even opens up the possibility of energy harvesting. With LoRaWAN, the sensors can be powered by a small solar panel, thermal energy or even radio energy scavenged from cellular phones. This extends the life of the sensor to multiple decades, a consideration for water and electricity infrastructure.
These are not just concepts, but systems that are currently being implemented in cities around the world.
For example, global consulting firm Capgemini used LoRaWAN standard in its Corporate Real Estate (CRE) services. Using a range of sensors, Capgemini can monitor the occupancy of rooms and desks to ensure the optimum use and make sure the buildings are the right size for the people using them.
With a range over 50m inside a building for the sensors using LoRaWAN, Capgemini found that one gateway can cover 10,000 square metres and thousands of sensors, making the technology cost effective and scalable across large buildings. The sub-gigahertz frequencies and robust protocols used by LoRaWAN provide excellent penetration throughout the building, reaching parts that other wireless technologies such as Wi-Fi and Bluetooth cannot without interference or losses, even in dense urban areas.
Capgemini’s ‘SmartOffice’ system has been developed specifically for building management and can reduce real estate management costs by between 10 and 15 percent. The data is available through a simple web interface so that building managers can quickly and easily see what is happening, but the data can also be fed into analytics software for further examination.
For applications across the wider smart city, the sensors have an even longer range up to 30km, and these can be picked up in new ways.
Amazon’s Sidewalk project is a crowd-sourced wireless network that can simplify device setup, extend the range for LoRa applications across the smart city. The LPWAN protocol is already implemented in devices such as the Ring doorbell, and Sidewalk extends this outside the house. This means sensors moving around the smart city can now be accessed wherever they are, for pet trackers, water sensors, sensors for asset tracking, and a multitude of additional low-cost devices across the smart home, providing convenience and support for residents.
All of this data feeds securely into the Amazon cloud for monitoring across smart buildings and the wider smart city. This is an additional way to be able to assess and analyse the data across the IoT.
One of the first developments for Sidewalk is with the American Red Cross to explore if it can support the tracking of blood collections supplies between distribution centres and donation sites to add new efficiencies within the blood donation supply chain.
As the leading supplier of the LoRa wireless chips for the LoRaWAN standard, Semtech is also working with SAS, a developer of massively parallel analytics and AI, on new ways to handle the deluge of data from all those sensors across the smart city.
The SAS IoT analytics tools, based on the Microsoft Azure cloud, use machine learning to monitor the data in real time to provide insights into activities. It has different sets of monitoring, from hotels to flood prevention to monitoring smart meters.
By 2026, nearly 20% of smart meters deployed by energy and water utilities worldwide will be connected using these LPWAN networks(1). Additionally, smart energy optimization and gas safety systems within cities can be monitored by LoRaWAN sensors. SAS combined their data with this sensor technology that can help maximize grid efficiency and predict and mitigate risk, keeping citizens safe
This highlights how the LoRaWAN sensor network can be agnostic to the data infrastructure and tools. This is vitally important for operators and managers of smart buildings and across the smart city who will be using a range of different data tools to assist the local citizens.
Low power wireless sensor networks are a key element of smart buildings and the expansion of the IoT in a way that allows the democratisation of data. Collecting that data from thousands of different places and making it easily available across the IoT can improve the life of the people across the smart city.
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