According to the United Nations Department of Economic and Social Affairs, it is estimated that by 2050 there will be 2.5 billion people added to urban areas. This will account for 68% of the world’s population, with the majority of growth occurring in China, India, and Nigeria. An increase in population density in urban settings will result in an increase in the total number of vehicles, buildings, and construction sites all around the area, which in turn will result in poor air and sound quality. According to the World Health Organization (WHO), “some 3.8 million premature deaths annually are attributed to outdoor air pollution. About 80% of those deaths are due to heart disease and stroke, while another 20% are from respiratory illnesses and cancers related to exposure to fine particulate matter”. Only 20% of the urban population surveyed by the WHO live in areas that comply with WHO air quality guideline levels. Pollution in major cities is almost 15 times higher than healthy guideline levels.
Our proposal discusses the deployment of a novel hybrid IoT network based on “Long Range” LoRa and “Short Range” BLE/ANT technologies that can cover up to 10km range in urban environment with a battery life of 3 to 5 years at relatively low cost. In addition, our system is integrated with commercial gas sensors and a microphone that will provide valuable information on air and sound quality and make it easily available to the general public.
Hybrid low-power wide-area mesh IoT network
LoRaWAN is one of the most promising low-power, wide-area network (LPWAN) solutions, currently gaining a lot of traction to support IoT applications and services based on the LoRa radio modulation technology. A new legacy wireless protocol, ANT+, is also popular because of its robustness and optimum energy consumption in developing Wireless Personal Area Networks (WPAN), which can be used in body parameter monitoring, smart homes, fitness sports services and gathering medical data within the range of 100 meters.
In this work, we propose a light-weight, hybrid mesh network combining the advantages of WPAN’s ultra-low power consumption (ANT) and LoRaWAN’s wide area coverage by integrating LoRa (physical layer of LoRaWAN) and ANT. Our IoT solution features are as follows:
• Large coverage: up to 10 km in urban environment
• Power efficient: 3 to 5 years of operation with 2 AA batteries
• Low cost: each wireless module would cost around $10, at high manufacture volume
To implement the proposed hybrid network and enable the data collection with different sensors for different applications, we have designed and manufactured our own hardware modules. Each wireless module will be packaged in waterproof containers that can be faced with many sensors depends on the different applications.
A prototype of our network consisting more than 15 sensors has been deployed around Purdue University campus (West Lafayette, USA) for more than 6 months, covering a wide area of almost 3 km2. Real-time data and visualization can be accessed from the following link:
Improving Air quality
Quantifying air quality is of extreme importance as we have discussed the hazards involving rapid urbanization and health. In order to determine air quality, we will integrate commercial gas sensors which detect some of the main air pollutants affecting people all around the globe. A second type of sensor will be integrated into the network, which uses a laser system to detect large particles in the air that are indicative of pollution.
Gas sensor list:
• Volatile Organic Compounds (ethanol, acetone, methanol)
• Fine Particles
Monitoring Sound quality
In order to monitor sound quality, an I2S digital microphone will be integrated into the system which can detect noise levels above healthy levels. According to the National Institute for Occupational Safety and Health, the maximum exposure time at 85 dBA is eight hours. At 110 dBA, the maximum exposure time is one minute and 29 seconds. Surprisingly, noise levels within this range can be reached during typical activities like motorcycles in a congested highway, riding the subway, or during a sporting event.
Data Quality and Access
In order to improve data quality and access, all information regarding air and sound quality will be made available to the public. The information will be stored in servers and accessible at any time. Information will also be displayed in a user-friendly manner at each measuring site, in order to provide access to those who do not have the financial means to navigate the internet or lack the technical background.
Impact around the world!
This novel design could truly change the perspective people have on how their surroundings affect their lifestyle. By providing real-time data, accessible to people of all backgrounds, everyone will be able to benefit from these measurements. The affordability of the sensors allows for simple replacement and maintenance of the devices and would make it accessible to communities all over the world. The versatility of using the LoRa network also allows easy integration of new sensors, as the technology in this area is sure to improve.