Considering the possible size of a forest and the absence of infrastructure within it, detecting the initial stages of a wildfire is a huge task.
Dryad has developed sensing nodes and networking technology to address the problem. Silvanet consists of three pieces of hardware: proprietary RF networking that extends the reach of the low-power and low-data-rate LoRaWan communications protocol; and a cloud analytics platform. It was designed to overcome constraints such as a lack of power and connectivity in the forest.
The first component is a solar-powered wildfire sensor node that collects data on basic environmental variables such as gas concentrations. It makes use of a low-power microcontroller with LoRaWan support and machine-learning processing built-in.
Solar-powered mesh gateways connect these devices. Dryad has used patented technology to join the gateways and construct a mesh of star networks that, when combined, can reach deep into a forest.
These two pieces combine to form an internet of trees that connects to the internet via a border gateway, which can be installed at the forest’s edge and works as a LoRa gateway, as well as providing 4G or 2G/GPRS access if needed.
The last component is a cloud platform that offers a full suite of wildfire detection and monitoring services. The platform can categorize sensor devices and gateways based on their location or attributes.
The forest environment poses a significant implementation issue. For example, instead of potentially poisonous and combustible rechargeable batteries, the system must use supercapacitors to power the sensors.
In addition to hardware development for energy-constrained data analytics, over-the-air update support, IoT security, and LoRaWan standards compliance, firmware development for energy-constrained data analytics, over-the-air update support, IoT security, and LoRaWan standards compliance is also required.
And everything of this must be accomplished using low-power devices and solar panels that are frequently in the shade. Furthermore, RF communications are difficult since every tree acts as a radio wave absorber.
Dryad collaborated extensively with Avnet Silica to investigate component solutions that would meet these requirements.
“Avnet Silica has been a close ally in the development of Silvanet,” said Carsten Brinkschulte, CEO of Dryad. “They have helped us in the selection of the right ultra-low power components, such as the sensor node MCU that integrates LoRa radio, but also has enough processing capability to analyse sensor data with enough sophistication to detect wildfires early. Additionally, Avnet has helped us to understand supply constraints for various parts, caused by supply-chain issues ranging from the pandemic through to factory fires, ensuring that we chose components available in enough volume to the rollout of sensors and gateways in significant volume.”
Ingo Seehagen, the senior field application engineer at Avnet Silica, added: “When you go to market and roll out your network with quantities rising, it becomes absolutely crucial to have all the microcontrollers and other parts delivered on time. We are now working with Dryad looking at potential optimizations of the designs featuring even lower-power devices and lower costs.”
According to Dryad, wildfire sensing is only the first application of its IoT technology. Once a Silvanet infrastructure is in place, it can track other aspects of forestry like soil moisture, tree growth, sap flow, and even illegal logging, as well as monitor air and water quality across wide areas.
Avnet Silica is Avnet’s European semiconductor specialist branch, which serves as a smart link between clients and suppliers. By offering technological and logistics support, the distributor reduces complexity. Avnet Silica supports projects from concept to production with a team of more than 200 application engineers and technical professionals. Belgium is home to the company’s European headquarters.