What is a Wireless Sensor Network?
A Wireless sensor network is a network of devices that can communicate the information sourced from a monitored environment via a wireless network. The data is sent ahead through different nodes. Then, through a gateway, the data is shared with other networks. IoT based Environmental Monitoring is one of the major applications of Wireless Sensor Network.
Wireless Sensor Network in IoT is a wireless network that consists of base stations and a number of nodes (wireless sensors). These networks are used to keep an eye on physical or environmental conditions like sound, pressure, temperature, and relay the data through the network to the control station. WSN in IoT helps achieve the full potentialities of IoT technology.
Components of Wsn :
Sensors in WSN are used to pick up the environmental variables data, and the sensor signals are then converted into electrical signals.
It receives the data generated by the sensors and forwards the same to the WLAN access point. It comprises transceiver, external memory, and power source.
WLAN Access Point / IoT Gateway
It receives the data from the Radio nodes wirelessly.
IoT Edge Gateway processes the received data from Radio Nodes. The processed data is used for further processing of the data for analysis, storage, and mining of the data.
Designing topology of Wireless Sensor Network
An optimal logical topology of a wireless sensor network (WSN) helps the deployed sensor nodes to communicate with each other with little overheads, lowers energy usage, increases lifetime of the network, provides scalability, raises reliability, and brings down latency. Numerous factors need to be considered in designing an optimal logical topology for a WSN. Chain oriented topologies have led to a number of improvements in energy consumptions, lifetime, and load balancing than other topologies of WSNs. However, their limitations include latency, scalability, reliability and interference problems.
Wireless Sensor network for Environmental Monitoring applications and scope
One of the most important and widespread applications of Wireless Sensor Network is Environmental monitoring. Environmental monitoring is not a short period monitoring but one that extends over months, year’s, and even lifetime sometimes. The lifetime of the sensor network is limited by the constraints of limited battery power in Battery powered Sensor nodes. This has indeed emerged as a key hurdle in upscaling WSNs for environmental monitoring. In recent times, WSNs have emerged to be vitally important in keeping an eye on environment real changes such as global warming. These days, the increased frequency and intensity of natural disasters has also necessitated the use of well-functioning WSNs to predict or warn about natural disasters.
IoT based Environmental Monitoring for air quality, carbon dioxide, smog-like gases, carbon monoxide in confined areas, indoor ozone levels
Air quality sensors are devices used to detect contaminants in the air. This includes particulates, pollutants and noxious gases that may be harmful to human health. They are used in applications like air quality monitoring, gas detection in industry, combustion controllers and oxygen generators in aircraft. Volatile organic compound (VOC) sensors are available that are capable of detecting volatile chemicals and odorous pollutants.
Monitoring of water for quality, pollutants and thermal contaminants
Water quality sensor information is commonly used for decision-making on a wide range of management issues, including meeting regulatory water quality requirements, identifying non-regulatory water quality for key users, confirming water quality modeling and applying a contamination warning system.
The chemical, biological and physical conditions of water indicate its quality in numerous ways. Even small shifts in these characteristics can impact the people and industries that rely on water. To maintain quality, tracking water parameters like conductivity, dissolved oxygen, pH, salinity, temperature and turbidity is essential.
IoT based Environmental Monitoring of soil for moisture and vibration levels to detect landslides
Soil can be monitored for detecting and preventing landslides. Slope sensors, soil moisture sensors, and vibration sensors are installed and connected using Wireless Sensor Network to monitor soil and give predictive data regarding landslides in any particular area.
Another similar application is monitoring of agricultural fields using various sensors which provide insightful data to grow crops more efficiently.
Monitoring forests and protected lands for forest fires
Wireless sensor networks (WSN) can be deployed in a large number of systems, one potential application is forest fire detection. Sensors are able to influence the physical parameters such as pressure, temperature, gases, radiations, humidity and many other parameters. Sensor network normally deployed in a large-scale random distribution on remote or inaccessible places and under harsh environments for a certain period of lifetime. This technology relied on low data rate and short ranges of communication with multi-hope fashion to reach the sink.
Monitoring for Natural disasters like earthquakes and Tsunami warning
All over the world, authorities are installing seismic sensors along with structural health monitoring(SHM) sensors (such as 3 axis deflection, vibration, stress, strain etc. ) on important structures like bridges, power transmission poles, hospitals etc. in active seismic zones. Such seismic monitoring equipment and instruments help the scientists to estimate the damages from minor earthquakes. Then, by taking help from mathematical models, it becomes possible to predict damage caused by major earthquakes.
Monitoring fisheries for both animal health and poaching
These days, continuous real-time monitoring of the water quality of inland fisheries is possible. The parameters being monitored are pH, temperature, turbidity, water level, dissolved oxygen & nitrogen, area-wise fish density. These systems also have provisions for (i) restoring water level if it decreases below threshold, (ii) automatic feed mechanism for fishes.
Monitoring snowfall levels at ski resorts and in natural forests for weather tracking and avalanche prevention
Snow levels can be monitored using ultrasonic sensors. Snow ultrasonic sensors are able to continuously measure snow depth. These are commonly used for hydrological monitoring and avalanche prediction. In natural forests, monitoring snow levels can give an idea about weather conditions.
Monitoring data centres for air temperature and humidity
As soon as there is a change in environmental conditions, a server, router, gateway, or other devices, the sensors notice it and the system sends alarm messages to designated personnel. Parameters such as temperature, humidity are monitored using such a sensor system.
Following are some of the important parameters monitored using Wireless Sensor Network (WSN).
- Air flow
- Flood and leak
Air flow sensors
Air flow sensors are used for control of air flows in ventilation and air-conditioning. Air flow sensors are quite easy to install and control the total pressure, the static pressure of the air flow and the average velocity of air.
These types of sensors are deployed for monitoring and detecting changes in air quality, presence of toxic, combustible or hazardous gases. Gas sensors are used in industries such as mining, oil and gas, chemical research and manufacturing. One of the most common consumer use cases of gas sensors is the carbon dioxide detectors used in many homes.
A pressure sensor is used to detect pressure changes. It senses changes in pressure of gases and liquids. When the pressure changes, the sensor detects these changes, and communicates them to connected systems. The most common use cases of pressure sensors include leak testing which can be a result of decay. Pressure sensors are also suitable for use in the manufacturing of water systems as it is easily able to detect fluctuations or drops in pressure.
Flood and leak sensors
These sensors are able to detect the presence of water, fuel, and other types of liquids. The wireless rope sensors issue alerts regarding liquid spillages, pump failures, or floods over wide areas. Wireless leak sensors can be mounted on walls or along pipes to detect leaks and frozen water. Besides detecting leaks, wireless sensors are also used to monitor water levels in diverse environments.
Wireless ultrasonic level sensors can be used to track water levels in lakes, reservoirs, storage tanks, and rivers.
Humidity sensors measure the amount of water vapor or moisture content in the atmosphere of air or other environments. Humidity sensors are most commonly used in heating, vents and air conditioning (HVAC) systems in both industrial and residential setups. They are also used in other areas such as hospitals, and meteorology stations to prepare weather reports and predict weather conditions.
Temperature sensors are used to detect temperature changes by measuring the amount of heat energy in a source. These temperature changes are recorded and then translated into data.
The most common applications of temperature sensors are in machinery used in manufacturing that often require environmental and device temperatures to be at specific levels. Similarly, they are also used in agriculture, where soil temperature is a key factor for crop growth.
PsiBorg , an IoT service provider, specializes in designing and building Wireless Sensor Networks for environmental monitoring. We build the most cutting edge WSN solutions tailor-made for your requirement and satisfaction.