Frequently Asked Questions

• General FAQs

• Silvanet FAQs

• Site Management FAQs

• Calibration FAQs

• Sensor FAQs

• Mesh Gateway FAQs

• Border Gateway FAQs

• Border Gateway solar panel FAQs

• LoRa Network FAQs

General

How do I contact Dryad Technical Support?

Both Dryad and authorized resellers provide customer support. To submit a Support Ticket to Dryad, use for Ticket form at Dryad Support. You need to provide:

• Customer name
• Email address
• Project name, location and Site ID
• Contact phone number
• Details request

Where do I find the Site ID?

A Site ID is a unique ID assigned to a Site by Dryad. It appears in the URL of a Site as well as the breadcrumbs line when a Site is opened. For example, dryad.app/sites/<Site ID>. A Site name can be changed but the Site ID cannot be changed. Use this Site ID when requesting support for a specific Site.

Silvanet FAQs

What is the Device ID?

A Device ID is a unique identifier of a node in a LoRaWAN network. In Silvanet, these nodes include the Silvanet Border Gateway, Mesh Gateway and sensor.

The Device ID is provided as a unique text string and QR Code printed on a label attached to the back of each Silvanet gateway and sensor. When scanned into the Silvanet Deployment app, the Device ID registers the device with the Silvanet Cloud. It also allows the Silvanet Cloud to know the location of the device in a Site.

What is FUOTA?

Firmware update Over the Air (FUOTA) is a standard for distributing firmware updates using unicast or multicast. It allows firmware updates to be delivered to many devices (Silvanet Sensors) at the same time efficiently and securely.

The Silvanet Cloud (Network Server) prepares to send updates as a multicast distribution. The firmware is chunked into transmittable parts. The Silvanet Cloud schedules each update chunk as a download message to the multicast group. The Network Server then verifies that each device has received all chunks, synthesizes them and verifies the update signature.

The end device (Silvanet Sensor) applies the firmware update and delivers a firmware update complete uplink message to the Network Server.

What is MQTT?

MQTT is a Client Server publish/subscribe messaging transport protocol that is lightweight, open, simple, and designed to be easy to implement. It is typically used for communication in Machine to Machine (M2M) and Internet of Things (IoT) contexts where a small code footprint is required and/or network bandwidth is at a premium. It is used by third-parties to communicate with a Silvanet Network.

Site Management FAQs

What is a Site?

A Site is a geographical area which has a dimension that is dynamically calculated based on the placement of Silvanet devices in a forest. A user creates Packets within a Site.

The Site Management app (dryad.app) displays all currently created Sites. Using your username and password, you are granted access to all Sites to which you are registered. After deployment, a Site can be monitored within the Site Management app.

How do I add a Site?

Only users having an Admin Role can add a new Site to their own organization. If you are a reseller, you can add new Sites for your clients.

If you are a user having a Standard Role, request a new Site from your organization's Admin user or from your reseller.

What is a Deployment Packet?

A Deployment Packet defines the Silvanet sensors and gateways that are to be deployed in a Site.

Silvanet Deployment Packets are created in the Site Management app and available to all registered users for deploying devices in a Site. Each Packet includes a list of Silvanet devices to be deployed and the location (GPS coordinates) where each device is to be deployed. When a device is deployed to a location, a user scans in the device’s QR Code which then syncs the device’s actual location to the corresponding entry in the Silvanet Cloud.

How do I access the Silvanet Site Management app?

The Site Management app is a web-base app which is accessed using dryad.app. Accessing the Site Management app requires a user to be registered with Dryad. After registration, a user is provided with login credentials. After logging in, the user is required to change their password.

How do I access the Silvanet Deployment app?

The Silvanet Deployment app is downloaded from Google or Apple Store onto a smartphone. The same credentials used to sign in to the Silvanet Management app are used to sign in to the Silvanet Deployment app.

Calibration FAQs

How much time do sensors require to calibrate?

14 days are required for initial calibration. After a Silvanet sensor has been deployed, the device's requires 14 days to calibrate, to "settle in" to the environment in which it has been deployed. After calibration, the gas sensor environmental readings have stabilized to an optimal level of sensitivity and ready to detect fires

How much time does a sensor require to return to normal values after gas scans?

2-4 hrs are required for the sensor to return to normal values after gas scans. After a sensor runs gas scans to test air quality, the sensor needs at least 2-4 hours to be ready to detect fires.

How much time is required for a sensor to be ready after moving it to a new location?

5 days are required for sensor recalibration after interactions with the sensor, including moving it to a new location. Any interactions with the sensor cause a complete recalibration which takes at least 5 days for the sensor to be ready to detect fires.

Sensor FAQs

How do I remove a sensor from my Site?

If you want to remove a device from your Site, you can cut the treenail at the bark level and remove the device. However, the device will continue to appear in the Site Management app for your Site. Contact Dryad Support to have the device removed also from the Site Management app. Provide to Dryad the Device ID to have the ID removed from the Site database.

Do sensors and gateways need regular maintenance?

We do not anticipate that sensors or gateways need to be serviced or cleaned. However, unusual circumstances (e.g. bird droppings) may present additional challenges for the gateways as they have a higher energy requirement than sensors. Due to its vertical positioning, these effects are minimized.

Should the sensors be replaced when a wildfire occurs nearby?

When there is a wildfire directly where the sensors are, they will, of course, be destroyed by the flames and need to be replaced. However, they will continue to run fire detection processes up to the point when they are destroyed.

In general, after a wildfire has been detected by our sensors and firefighting occurs in the area of the sensors, the sensors in the area should be replaced. Also, if the sensors that have been massively soaked in chemicals, such as to extinguish fires, they are most likely going to be contaminated and should be replaced. The sensors may continue to work, but to ensure they function, we recommend replacing them after fire fighting.

Silvanet Mesh Gateway FAQs

How does a Mesh Gateway operate in the Silvanet Network?

Mesh Gateways receive messages from sensors and forward them using the LoRaWAN mesh network to other Mesh Gateways within range and to Border Gateways within range. Messages sent from sensors hop through the mesh network until they reach the Border Gateway.

How high should a Mesh Gateway be attached to a tree?

The Silvanet Mesh Gateway should be attached to a tree or a pole at least 3 meters above the forest floor. At this height, the device has less interference from human or animal interactions.

Should the Mesh Gateway always face southward?

A Mesh Gateway should face southward only in the norther hemisphere. Find a location where the solar panel can obtain maximum sunlight. Ensure it is oriented towards the sun (at 12:00 noon) whether in the northern or souther hemisphere.

Silvanet Border Gateway FAQs

How does a Border Gateway operate in the Silvanet Network?

Border Gateways sends messages received from the Silvanet Mesh Network and forwards them to the Silvanet Cloud using one of three services to connect to the Internet - Ethernet (requires access to a router), LTE-M mobile networks (requires 4G network) or satellite communication (as a backup). It needs to be "always on" which means it needs a reliable power supply. It also supports FUOTA to allow sensor firmware to be updated remotely.

What type of PoE Adapter is used with the Border Gateway?

The Border Gateway is supplied with a PoE Adapter that provides a voltage range of between 36V and 57V. The PoE must be IEEE 802.3af compliant.

Why is my Border Gateway offline?

A Border Gateway can be offline due to three reasons.

• Network connectivity issues
• Power saving
• Insufficient power supply

What happens to sensor data if the Border Gateway loses Internet connectivity?

If the Border Gateway loses network connectivity, it queues all the sensor data it received from sensors and Mesh Gateway and sends the data to the cloud once the network connection has been established. The same process occurs While the Border Gateway is in power saving mode.

If the Border Gateway is down due to low power, the entire system will be offline. In these conditions, the Mesh Gateway will attempt to send the data to the Border Gateway but since there is no Border Gateway the data will be lost.

How high should a Border Gateway be attached to a tree?

The Silvanet Border Gateway should be attached to a tree or a pole at least 3 meters above the forest floor. At this height, the device has less interference from human or animal interactions.

Should the Border Gateway always face southward?

A Border Gateway should face southward only in the norther hemisphere. Find a location where the solar panel can obtain maximum sunlight. Ensure it is oriented towards the sun (at 12:00 noon) whether in the northern or souther hemisphere.

Border Gateway solar panel FAQs

Why does the Border Gateway include a Solar Panel?

The Border Gateway includes a separate solar panel to provide the device with a backup power supply. It is connected to the Border Gateway with a 2 m cable and is delivered to customers pre-connected to the Border Gateway.

Can the solar panel be disconnected from the Border Gateway?

If required, the Border Gateway can be disconnected from the Border Gateway.

How long does it take for the solar panel to charge the Border Gateway supercapacitors?

The solar panel needs 3 to 4 hours to charge the superconductors in the Border Gateway before it comes online. However, if the PoE is disconnected or if a power failure occurs in the mains, the Border Gateway needs 1 to 2 days to begin operating properly.

How do I determine if the solar panel is damaged?

First, disconnect the solar panel from Border Gateway and measure the voltage. It should be around 20 V. If not, it does not have sufficient light or the solar cell is damaged.

Do solar panels need regular maintenance?

The solar panels are placed vertically (by intention) on a tree or pole. This position minimizes dust buildup and allows rain to wash off any dust or dirt. This vertical position is intentionally to eliminate manual servicing (cleaning).

Can I anticipate solar panels to degrade over time?

The solar panels have been intentionally oversized to allow for performance degradation over time while still maintaining functionality.

Fire detection FAQs

What are gas scans?

The gas sensor in the Silvanet sensor runs a set of gas scans to test if the sensor has detected a fire or some other VOC. The gas sensor runs up to 60 consecutive gas scans which is the real test for a fire. However since gas scans consume a significant amount of energy, they are kept to a minimum and only start if the sensor detects a change in the gas composition of the air consistent with smoke from a fire.

How is an ML model used in Silvanet?

A Machine Learning (ML) model is a program that has been trained to recognize certain types of patterns. You can train a model over a set of data, providing it an algorithm that it can use to make predictions and learn from those data. ML models find patterns and make decisions in previously unseen data and make predictions about that data. A ML Model recognizes patterns by having it “trained” with large datasets. Training involves optimizing the machine learning algorithm to find certain patterns or outputs from the dataset. The output - a ML Model - is a computer program with specific rules and data structures.

What are Volatile Organic Compounds (VOC)?

A VOC (Volatile Organic Compound) is an organic chemical compound that evaporates easily at room temperature. They vaporize into air and dissolve in water, for example smoke from fires. Organic compounds are chemicals that contain carbon and are found in all living things, especially trees. VOCs are also emitted from, for example, oil and gas fields and diesel exhaust which is why the sensors use ML Models to distinguish between VOCs from fires and VOCs from other sources.

The US EPA (Environmental Protection Agency) defines VOCs as follows:

Volatile organic compounds (VOC) means any compound of carbon, excluding carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates and ammonium carbonate, which participates in atmospheric photochemical reactions, except those designated by EPA as having negligible photochemical reactivity.

How is fire intensity measured?

The most important measure of fire behavior is fire intensity. Fire intensity (I) represents the heat released per meter of fire front (kW/m of fire front). It is a function of (1) heat yield of fuel (kilojoules/kg), (2) amount of fuel per unit area (kg/m2) and (3) the rate of forward spread of fire front (km/h).

LoRa Network FAQs

What is LoRa?

LoRA ("Longe Range") is a proprietary modulation technique by Semtech. It is based on Chirp Spread Spectrum (CSS) where a CHIRP (Compressed High Intensity Radar Pulse) is a signal that carries data. Chirps have two types of signals - an up-chirp and a down-chirp. An up-chirp increases in frequency while a down-chirp decreases in frequency. LoRa is ideal for IoT applications like the Silvanet sensor as they transmit small data packets with low bit rates.

LoRA has an advantage over other techniques as data can be transmitted at longer ranges. This allows Gateways to be located at greater distances from sensors, thus reducing the number of gateways required per deployment.

What is LoRaWAN?

LoRaWAN ("LoRa Wide Area Network") is a standard of ITU and is managed by the LoRa Alliance.

It is built on top of LoRa in the MAC layer. It defines how devices use the LoRa hardware, such as when the devices can transmit and receive messages, as well as the format of the messages. LoRaWAN is optimized to operate in low power mode and can transmit as far as 10 km in open fields, less in forests and up to 3 km in urban areas with significant interference. LoRaWAN also allows for firmware updates and updates to the ML Model on sensors over the air (FUOTA).

Which frequency bands are used in North America, Europe and Asia?

LoRa frequency bands

• Europe: 868 MHz

• North America: 915 MHz

• Asia: 433 MHz

See LoRa frequency bands

What is a Data Packet?

Data packets are not to be confused with Deployment Packets.

A data packet is defined by the ISO model They are data units within the Network Layer. They include the source and destination IP addresses as well as other information. Data packets are, essentially, a connection-oriented protocol. They ensure each single packet is not dropped or compromised and are considered a reliable form of communication. An acknowledgement (ACK) packet is usually sent as a reply to a received data packet. If no ACK packet is received, the data packet is simply resent. LoRa uses data packets to communicate between LoRa enabled devices (sensors and gateways) and are part of the definition of a LoRaWAN network.