Glossary

LoRa

LoRa is a wireless communication method based on chirp spread spectrum. It sends information using chirp-like pulses, similar to how dolphins and bats communicate.

LoRa works best when you need to send small amounts of data at low speeds. The signals are strong and reliable, even in noisy environments. They can travel about 5 km in cities and more than 15 km in rural areas if there is line of sight. LoRa devices use very little energy, and many can run for up to ten years on a small coin cell battery.

LoRaWAN

LoRaWAN is the smart rulebook that tells LoRa devices how to talk to each other. It sits on top of LoRa modulation and manages things like when a device should send data and what the messages should look like. This protocol is looked after by the LoRa Alliance.

Why it matters: LoRaWAN is a great choice when you need to send small amounts of data without using much power. Devices can run for up to ten years on a tiny coin cell battery. Networks can stretch across impressive distances, up to 15 km in the countryside. Setting up and running LoRaWAN is affordable, and it comes with a lot of built-in features such as geolocation, modern security, roaming, and support for many devices at once. Since it runs on license-free spectrum, anyone can set up their own network.

Packet Forwarder

A Packet Forwarder is software that runs on a gateway. Its job is simple: it picks up LoRa packets from devices and sends them to a Network Server, and it can also send packets back to devices. There are two main types in use today. The older one is the Semtech UDP packet forwarder, which is very common but does not provide secure communication. The newer one is LoRa Basics™ Station, which includes extra features such as centralized updates, TLS authentication for security, and managed frequency plans.

Packet forwarders do not need to know what the packets contain. They simply pass everything on to the network. This makes them flexible and lightweight. They can even run on simple, low-cost hardware. Because of this, expanding LoRaWAN network coverage is easy. You just add more gateways running a packet forwarder.

CRC

A Cyclic Redundancy Check, or CRC, is a method used to spot errors in digital data. When data is sent from one place to another, the CRC helps make sure nothing has been accidentally changed along the way.

CRCs make digital communication more reliable. They let us detect mistakes that happen when data travels through noisy channels, so we can trust the information we receive.

Spreading Factor

The spreading factor is a setting that changes how data is “spread out” before being sent over LoRaWAN. Think of it as a way to make the signal easier to detect and decode. LoRaWAN uses six spreading factors, from SF7 to SF12.

Adjusting the spreading factor helps balance speed, power, and range. A lower spreading factor can send data faster and use less power, but the range is shorter. A higher spreading factor increases range but slows down transmission. It also helps reduce network congestion, because signals with different spreading factors on the same channel don’t interfere with each other.

Bandwidth

Bandwidth is the range of frequencies that a radio signal uses. It is measured in Hertz (Hz). You can think of it as the “width” of the signal. The lower limit of the frequency is fl, the upper limit is fh, and the middle is the center frequency (fc).

Bandwidth affects how long it takes to send a message and how sensitive the receiver is. Using a larger bandwidth makes transmissions faster and reduces power use. However, it also makes the receiver less sensitive to weak signals

Uplink Message

An uplink message is a message sent from a device to the network server. One or more gateways pass the message along to ensure it reaches its destination.

Uplinks let your applications gather data from sensors anywhere. Devices can run on batteries or mains power, be in busy cities or remote locations, and be stationary or on the move. This flexibility opens up endless possibilities — how far you take your application is limited only by your imagination.

Downlink Message

A downlink message is sent from the network server or application server to a device. A single gateway passes the message along to reach the device.

Downlinks let you control or update your devices remotely. You can change settings, update firmware, adjust room temperature, update signage, or trigger a light to notify users. They are also used to deliver security updates, keeping your devices safe and up to date.

End Device

An end device is a sensor or actuator that connects wirelessly to a LoRaWAN network. It sends and receives data to help your applications work.

End devices can be used in a wide variety of applications. Some popular examples include:

• Monitoring vaccine cold chains
• Protecting wildlife and tracking animals
• Smart farming and agriculture
• Ensuring food safety
• Managing smart waste bins
• Smart parking solutions
• Facility management

With LoRaWAN, the possibilities for end devices are almost limitless.

Network Server

The Network Server is the central manager of a LoRaWAN network. It handles messages coming from devices through gateways (uplinks) and sends messages back to devices (downlinks).

The Network Server does a lot behind the scenes. It activates devices, removes duplicate messages, confirms message delivery, tracks device locations, and adjusts data rates to keep the network running smoothly. In short, it keeps the LoRaWAN network organized, efficient, and reliable.

Application Server

The application server handles the data that comes from end devices. It also creates and sends messages back to devices through the network server. A LoRaWAN network can have multiple application servers working together.

The application server separates the application from the network itself. This means you can analyze, visualize, or use the collected data with third-party tools, without sharing sensitive application keys with the network. It gives you flexibility and keeps your data secure.

Join Server

The Join Server handles join requests from end devices. It keeps the root keys safe, creates session keys, and shares those keys with the network server and application server. The Join Server is part of LoRaWAN versions 1.1 and 1.0.4.

The Join Server makes adding devices secure and simple. Devices can be provisioned without being tied to a specific network. Manufacturers only need to store keys in one secure place. When a buyer gets the device, they can claim it with a single click. After that, the device can connect to any LoRaWAN-compliant network, giving full flexibility and security.

Adaptive Data Rate (ADR)

Adaptive Data Rate, or ADR, is a feature that helps the network optimize how devices send data. It balances the speed of transmission, time on air, and power usage.

ADR adjusts key transmission settings on each device:

• Spreading factor – controls signal reach and speed
• Bandwidth – affects transmission time and power use
• Transmission power – manages energy consumption

Using ADR ensures devices communicate efficiently while saving battery and reducing network congestion.

ADR helps save device battery while making sure messages still reach the gateways. The network server tells each device whether to lower its transmission power or increase its data rate. Devices close to a gateway can use a lower spreading factor and higher data rate. Devices farther away need a higher spreading factor for a stronger link. This ensures the network stays efficient and reliable for all devices.

Effective Isotropic Radiated Power (EIRP)

EIRP is the total power that an antenna would radiate if it sent signals equally in all directions. It is measured in dBm or Watts. The maximum EIRP allowed varies depending on the region.

Antenna power affects both the range of your device and its battery life. It is also a key factor in Adaptive Data Rate (ADR). Devices that need to send data over long distances can use higher power, while devices close to gateways can lower their power to save energy.

Received Signal Strength Indicator (RSSI)

The Received Signal Strength Indicator (RSSI) is the power of a received signal, measured in dBm. It indicates how well the signal is being received.

RSSI is used in the ADR feedback loop to check if a signal is strong enough. If the signal is sufficient, the device can increase its data rate and save battery. A high RSSI means the device can reduce transmission power while ensuring messages are still received.

Signal-to-Noise Ratio (SNR)

SNR shows the ratio between the power of a received signal and the background noise. It is measured in decibels (dB) and tells you how clear the signal is compared to the noise.

SNR helps the network decide if a device can safely increase its data rate and save battery. A high SNR means the signal is strong and clear, so the device can lower its transmission power while still making sure messages get through.

Noise Floor

The noise floor is the total level of background noise in a measurement system. It usually represents the smallest signal the system can detect.

LoRa and other spread spectrum technologies can pick up signals even below the noise floor. They do this by spreading the information across the entire frequency bandwidth, making weak signals detectable.

Frequency

Frequency is how many times a radio wave oscillates each second, measured in hertz (Hz). The radio spectrum ranges from 30 Hz to 300 GHz. To avoid interference, governments regulate how different frequencies can be used.

LoRa works in license-free frequency bands. This means you can deploy a LoRaWAN network without paying for expensive spectrum licenses, making it easier and more affordable to get started.

Forward Error Correction (FEC)

Forward Error Correction adds extra information to data before it’s sent. This allows the receiver to check for errors and accept only data that looks correct.

FEC helps detect and sometimes fix errors caused by interference during transmission. Adding this redundant data makes communication more reliable, though it can slightly reduce the effective data rate.

Frequency Plan

A Frequency Plan sets the data rates and channels that follow LoRaWAN’s regional rules for a specific band or area. Devices are configured with a Frequency Plan when they are activated, and they can use any plan supported within their band.

LoRa works in license-free spectrum, but the available frequencies differ by region. Frequency Plans standardize how devices operate across different areas, making it easier to deploy and manage LoRaWAN networks globally.

Activation

Before an end device can send or receive messages, it must be registered with a network. This process is called activation. There are two ways to activate a device: Over-The-Air Activation (OTA), which is the most secure and flexible, and Activation By Personalization (ABP), which is simpler but less secure and flexible.

Activation is network-independent, meaning devices can join any LoRaWAN network. This prevents vendor lock-in and allows you to easily move or reuse your devices across different networks.

Over-The-Air Activation (OTA)

OTAA is the most secure way to activate end devices. During this process, the device joins the network, receives a dynamic device address, and negotiates security keys with the network.

OTAA offers maximum security and flexibility. Keys are exchanged safely, and devices can be activated on another network without physically touching them.

ctivation By Personalization (ABP)

ABP is a simpler, less secure method of activation. Security keys must be manually programmed into the device and entered into the network.

Device Classes

LoRaWAN defines three types of devices: Class A, Class B, and Class C.

• Class A devices listen for downlink messages only right after they send an uplink.
• Class B devices add scheduled receive windows at regular intervals.
• Class C devices are always listening for downlinks.

Every LoRaWAN device must support Class A. Classes B and C are optional extensions.

Device classes let you pick the best option for your use case. Class A devices save battery by sleeping most of the time and only checking for messages after sending data. This allows them to last for years on a single battery cell. Class B devices offer predictable message timing but use more battery. Class C devices can receive messages anytime, so they are usually mains powered.

Coding Rate

The coding rate determines how many bits carry actual information versus how many are used for error correction. For example, a coding rate of 4/5 means 4 bits carry information and 1 bit is added for error correction, for a total of 5 bits.

LoRa uses these coding rates:

• 1: 4/5 (1 error correction bit for 4 information bits)
• 2: 4/6 (2 error correction bits for 4 information bits)
• 3: 4/7 (3 error correction bits for 4 information bits)
• 4: 4/8 (4 error correction bits for 4 information bits)

Coding rates let the network control how much extra data is sent to protect against errors. If there is little interference, a faster coding rate can be used. This reduces redundant data and allows more actual information to be transmitted per second, improving efficiency.

Time on Air

Time on Air is how long a transmitter is active to complete a transmission. In LoRa, it includes both the preamble and the payload. The spreading factor and coding rate determine how long it takes to send a given message and affect how much data a device can transmit.

Regulatory authorities set limits on how long devices can transmit to prevent overcrowding on public frequencies. Network operators may also set additional limits, called a “Fair Access Policy,” to ensure everyone gets a chance to use the network. Following these rules helps devices share the license-free spectrum efficiently.

Decibel (dB)

The decibel (dB) is a unit used to compare quantities on a logarithmic scale. In radio transmission, it often describes antenna gain or signal-to-noise ratio. For example, antenna gain can be calculated using:

X = 10 \times \log_{10}\left(\frac{P_i}{P_o}\right) \text{ dB}

where Pi is input power and Po is output power.

Using decibels makes it easy to see gains and losses in a signal path. For example, a 10 dB loss followed by a 5 dB gain results in a net 5 dB loss. Doing the same calculation in raw power values would be more complex, involving multiple multiplications. Decibels make signal analysis much simpler.

Decibel-milliwatts (dBm)

dBm is a unit that expresses power in decibels relative to 1 milliwatt (mW).

Even though dBm isn’t an official SI unit, it’s widely used and very practical for setting standards and comparing signal power levels easily.