Glossary

Description of terms and phrases used in Silvanet Dryad Documentation.

Air quality

Air quality is quantified as an Index of Air Quality (IAQ) which indicates the quality of air within range of the sensor. It is used by the Silvanet sensor to trigger the fire detection process, if it passes a defined threshold. See IAQ below.

Active state

A Silvanet device (Border Gateway, Mesh Gateway or Wildfire Sensor) is considered in Active state after it has been registered with the Silvanet Cloud. It does not necessarily indicate the device is sending messages to the Silvanet Cloud via Silvanet Mesh Network. An active state is indicated by a green status icon.

ALOHA

Random access protocol. LoRaWAN networks use an ALOHA-based protocol so end devices do not need to peer with specific gateways.

Border Gateway

A Border Gateway receives messages from Silvanet sensors via Mesh Gateways using LoRaWAN and forwards the messages to the Silvanet Cloud using one of three services: LTE-M (mobile), Ethernet (PoE adapter and router) or satellite.

Calibration (sensor)

Once deployed, the Silvanet Wildfire Sensor needs to perform a 14-day calibration after deployment. This is critical for allowing the sensor to detect a smoldering fire. During this period the Sensor does not detect smoldering fires.

CSS

LoRA is based on Chirp Spread Spectrum (CSS) where a CHIRP (Compressed High Intensity Radar Pulse) is a type of signal that is the carrier of data. Chirps have two types of signals: up-chirp and down-chirp. An up-chirp increases in frequency while a down-chirp decreases in frequency.

Data packets

According to the ISO model, data packets are data units within the Network Layer. They include the source and destination IP addresses, as well as other information. Packets are essentially a connection-oriented protocol. It ensures each single packet is not dropped or compromised. It is considered reliable communication.

Device ID (Serial ID)

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

The Device ID is provided as a unique text string and QR Code. The Device ID is used to register the device with the Silvanet Cloud. It also allows the Silvanet Cloud to know the location of the device in a Site.

Device Address (DevAddr)

Address by which the device is known in the Mesh network. It is composed of two parts: the address prefix and the network address. It defines an end device within the current network and all communication between devices use it after joining the network.

Downlink messages

Messages sent from Gateways to devices lower down in the hierarchy; for example, messages sent from the Silvanet Cloud to Border Gateways, Border Gateways to Mesh Gateways or Mesh Gateways to sensors are downlink messages. Satellites do not send downlink messages to Border Gateways.

End device

In Silvanet, it is the Wildfire Sensor that sends LoRa-modulated wireless messages to Silvanet Gateways (Border or Mesh) and receives messages from these Gateways.

EUI

Extended Unique Identifier. It is a 64-bit unique identifier as defined by IEEE. Dryad assigns a unique identifier (EUI) to each device. Each device's EUI consists of a unique combination of a DevEUI and a JoinEUI.

False alerts

During the calibration period and up to one month after deploying, the sensor may trigger false fire alerts. This is normal behavior and is expected.

Fire alerts

A sensor triggers a fire alert after the sensor determines with a high probability that a fire has been detected. The fire alert is sent immediately to registered users via the Silvanet Cloud.

Fire intensity

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 the following:

• Heat yield of fuel (kilojoules/kg)

• Amount of fuel per unit area (kg/m2)

• Rate of forward spread of fire front (km/h)

Firmware version

Version of the firmware loaded in the device memory.

FUOTA

Firmware Update Over the Air.

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

FUOTA uses a chunked image transfer (no compression). To allow for any low power periods as well as various regional regulatory requirements, FUOTA processes can be configured to stretch over an extended period such as a week. It can be configured by downlink fragment size and periodicity of transmissions.

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.

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 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.

Gateway ID

Unique text string and QR Code that identifies a Gateway (Border or Mesh) in the Silvanet Cloud. Same as Device ID. See Device ID.

IAQ

Index of Air Quality. It is an index that has a range of values that indicates or quantifies the quality of the air in the environment surrounding the sensor. The threshold value which triggers a fire detection process is defined by Dryad.

Interactions (with Sensors)

Interacting with a sensor causes the sensor to be recalibrated. Interactions can include touching the sensors in any way, moving the sensors in any way, being in proximity to the sensors and running machinery and vehicles, especially diesel, near the sensor. It can also include bringing any source near the sensor that could trigger the fire detection such as cigarettes and even breathing on the sensor.

IoT

Internet of Things. Silvanet devices are IoT devices.

JoinEUI

A 64 bit extended unique identifier.

LoRa

LoRA (Long Range") is a proprietary modulation technique by Semtech.

The key advantages for using LoRa is its low power usage and long range. It is ideal for Silvanet devices as they send small amounts of data over long distances periodically (under normal conditions). This allows the devices to operate using solar panels.

It also allows Silvanet Gateways to be located at greater distances from Wildfire Sensors, thus reducing the number of gateways required per deployment.

LoRa networks can achieve a maximum throughput of 50 Kbps (100 bytes/min in normal conditions). Additionally, it is approved as a standard for Low Power Wide Area Networking (LPWAN) by the ITU (International Telecommunication Union). As it operates in the license-free sub-gigahertz bands (such as 915 MHz, 868 MHz and 433 MHz), it is subject to interference and retransmissions.

LoRaWAN

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

LoRaWAN is a Medium Access Control (MAC) Layer protocol that manages communication between Silvanet Gateways and Wildfire Sensors in the Silvanet Network. It is a software built on top of LoRa hardware and defines, amongst other things, when data packets are transmitted and the format of those 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).

Each node (device) in a LoRaWAN network contains its own unique Device ID.

LoRaWAN Version

Indicates the MAC layer version used by a Silvanet device, for example MAC_V1_0_3.

LoRaWAN PHY Version

Indicates the PHY Version used by a Silvanet device, for example PHY_V1_0_3_REV_A.

LTE-M

LTE-M which is a type of 4G cellular network. It is designed for IoT devices to connect to mobile networks. Dryad Border Gateways use LTE Cat M1. It is designed to allow IoT devices to go into Power Saving Mode to reduce energy consumption. It also allows FUOTA without draining the supercapacitors in the Border Gateway. (Optionally, the Border Gateway can also support NB-IoT.)

Mesh Gateway

Mesh Gateways receives messages from sensors and forwards the messages to other Mesh Gateways or, if in range, to a Border Gateway using the Silvanet Mesh Network. Messages sent from Wildfire Sensors hop through Mesh Gateways until reaching a Mesh Gateway within range of a Border Gateway.

Mesh network

A LAN topology in which nodes can connect directly in a non-hierarchical way to as many other nodes as possible to find the most efficient route to end nodes. Silvanet implements mesh networking.

ML Model

A ML (machine learning) model is a program that has been trained to recognize certain types of patterns. In Silvanet, the ML Model has been trained to recognize certain types of patterns, in this case the gases from a smoldering fire.

ML Version

A version of the Machine Learning (ML) model loaded in the memory of the Silvanet Device. It is updated to all sensors in a Site using FUOTA.

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.

Network Server

In the Silvanet System, the Network Server is the Silvanet Cloud which manages the entire Silvanet network. If It receives multiple copies of the same message, it keeps a single copy of the message and discards the others (preventing message duplication).

NS Gateway ID

Network Server Gateway ID. Same as Gateway ID.

OTAA

Over The Air Activation. FUOTA (Firmware Update Over the Air) uses OTAA to update Wildfire Sensor firmware.

Packet (deployment)

A Deployment Packet defines the Silvanet Wildfire Sensors and Gateways deployed (or in the process of being deployed) in a Site. It typically include the planned deployment locations of the devices. More than one Packet can be prepared for Site deployments. They are prepared using the Site Management app and made available in the Silvanet Deployment app.

Phase 1 alert

A Phase 1 alert is not necessarily an indicator of a fire. However, when a Silvanet sensor triggers a Phase 1 alert (yellow), it indicates a deterioration in air quality in the surrounding environment. Phase 1 alerts are used as an optimization to reduce the number of gas scans (which check for fire) and only do so when there is a change in the gas composition of the air.

Phase 2 alert

If the sensor determines a fire is the most likely cause for the deterioration of air quality (which is indicated by a Phase 1 alert), the sensor immediately issues a Phase 2 fire alert sent to the Site's registered users.

PoE Injector (PoE adapter)

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

Power saving mode

To save energy, the Border Gateway switches into power saving mode for 60 minutes then wakes up for 5 minutes to listen to the Silvanet Mesh Network and sends all messages from sensors that have been queued. In case of fire alerts, it wakes up immediately and sends the alerts to the Silvanet Cloud.

Sensor (Silvanet Wildfire)

The Silvanet Wildfire Sensor is designed to detect forest fires during the early stages (even during the smoldering phase) within minutes. The sensor monitors the microclimate by measuring temperature, humidity and air pressure.

Sensor ID

Unique text string and QR Code that identifies a Silvanet Wildfire Sensor in the Silvanet Cloud. Same as Device ID. See Device ID.

Serial ID

Same as Device ID. See Device ID.

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.

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.

Smoldering fire

A smoldering fire is defined to be a slow, flameless combustion of a biomass material such as forest floor material, branches, leaves, and so on.

Supercapacitor

A supercapacitor is a high capacity capacitor that can accept and deliver charges faster than batteries and tolerates many more charge and discharge cycles than rechargeable batteries.

Uplink Messages

Transmissions sent by end-devices to the Network Server relayed by one or many gateways. Satellites only receive Fire Alerts messages from Border Gateways.

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.