Meshtastic Glossary

App / Application / Client Application

An application that connects to a Meshtastic node to send and receive messages via the mesh.

See also: Client

Airtime (Time on Air)

The length of time a LoRa transmission occupies the channel. Longer-range settings usually increase airtime and reduce throughput.

APRS (Automatic Packet Reporting System)

A ham radio data system sometimes bridged to and from Meshtastic by communities. Check local regulations and community guidance before use.

See also: Gateway, MQTT Bridge

Band (ISM Band)

The regional frequency range for LoRa, such as 915 MHz or 868 MHz. Devices must operate on the correct regional band.

Bandwidth (LoRa)

A LoRa radio parameter that affects data rate and range. It is included in modem presets.

BLE (Bluetooth Low Energy)

A short-range wireless link commonly used by Meshtastic apps to connect to nodes.

Bridge

A general term for linking the mesh to another network or service.

See also: Gateway, MQTT Bridge

Broadcast

A message sent to all participants on the current channel.

Channel

A logical grouping that defines who can communicate. It includes a name, encryption, and settings.

Channel Key

The shared encryption key for a channel.

See also: PSK (Pre-Shared Key)

Client

A node used primarily for user messaging. Its exact behavior depends on the assigned role.

See also: Role (Device Role)

CLIENT_BASE

A client-mode baseline used by this community for personal nodes so they prefer direct routes without consuming unnecessary hops through infrastructure nodes.

In community guidance, routers, gateways, and other personal nodes are often marked as favorites so CLIENT_BASE can take advantage of zero-hop behavior where appropriate.

See also: Client, Favorites

CLI (Command Line Interface)

A text-based interface, usually over USB or serial, used to configure or interact with a node.

Coding Rate (CR)

The LoRa forward error correction setting that trades speed for robustness. It is included in modem presets.

Deduplication

Logic that avoids processing or rebroadcasting the same packet multiple times.

See also: Rebroadcast Logic

Device

A Meshtastic-compatible radio running Meshtastic firmware.

Device Role

The behavior mode assigned to a node on the mesh.

See also: Role (Device Role)

DFU (Device Firmware Update)

A special mode used for firmware updates.

Direct Message (DM)

Encrypted, point-to-point communication that uses public key cryptography.

See also: PKC (Public Key Cryptography)

Encryption

Channel messages are protected with a pre-shared key. Direct messages can use public key cryptography.

ESP32

An Espressif microcontroller used in many devices. It usually uses more power than NRF52 and can support Wi-Fi features.

EUI / EIRP

Regulatory and power-related concepts that may appear in compliance discussions. Always follow regional rules and onboarding guidance.

FAQ

A collection of answers to common community questions and practices.

Favorites

A Meshtastic app list of preferred nodes. In this community setup it is commonly used to mark routers, gateways, and personal nodes so client devices can avoid spending unnecessary hops.

See also: CLIENT_BASE

FEC (Forward Error Correction)

Another name for the coding rate setting.

See also: Coding Rate (CR)

Firmware

The low-level software that runs on a node microcontroller.

Flash / Flashing

Installing or updating firmware on a device.

Freq51

Community coordination around stable deployments, recommended settings, and onboarding for a healthy mesh.

Gateway

A node that bridges the mesh to external systems, often through MQTT. It needs careful configuration to avoid loops and flooding.

GPIO (General Purpose Input/Output)

Digital pins that can be used for sensors, buttons, and other hardware integrations.

GPS

Global Positioning System. Nodes can report their position as telemetry.

Hop

A relay through another node.

Hop Limit

The maximum number of hops a packet may traverse. It helps control congestion and airtime usage.

Hidden Client

A client role that participates without appearing prominently in lists or user interfaces.

See also: Role (Device Role)

ID (Node ID / Long Name / Short Name)

Identifiers used to recognize a node in the mesh and in user interfaces.

Interval (Telemetry / Position)

How often telemetry or position updates are sent. It should balance visibility with airtime usage.

Key (Channel Key)

The encryption key shared by all nodes on a channel.

See also: PSK (Pre-Shared Key)

LoRa

The low-power, long-range radio technology used by Meshtastic.

LoS (Line of Sight)

A clear, unobstructed radio path through the air. The best link quality usually requires line of sight.

Lost and Found

A special role used for recovery or identification scenarios.

See also: Role (Device Role)

Mesh Network

A decentralized network where nodes can forward messages for each other.

Modem Preset

A bundled set of LoRa parameters such as bandwidth, spreading factor, and coding rate. All communicating nodes must match.

• SHORT_TURBO - Highest bandwidth and shortest range.
• SHORT_FAST - High speed and short range.
• SHORT_SLOW - Moderate range with fairly high speed.
• MEDIUM_FAST - Balanced speed and range.
• MEDIUM_SLOW - More range and less speed.
• LONG_FAST - Default choice with long range and reasonable speed.
• LONG_MODERATE - More range and airtime, slower than LONG_FAST.
• LONG_SLOW - Very high link budget and very slow data rate.
• VERY_LONG_SLOW - Slowest option, very high range, and high airtime.

As a general community default, LONG_FAST is the safest baseline unless the mesh coordinates something else.

MQTT / MQTT Bridge

A protocol and bridge commonly used to link the mesh to servers or services. Topics, filters, and rebroadcast logic must be configured carefully to prevent loops.

Node

A device on the mesh that can send, receive, and relay messages.

NRF52

A Nordic microcontroller used in many low-power Meshtastic devices.

OTA (Over-the-Air)

Wireless firmware update capability, depending on the device and platform.

Packet

A unit of data sent over the mesh.

PKC (Public Key Cryptography)

Public and private key cryptography used for direct, end-to-end messages.

Preset

A shorthand name for a bundled radio configuration.

See also: Modem Preset

Protobuf

Google serialization format used by Meshtastic protocols.

PSK (Pre-Shared Key)

The channel encryption key. All nodes on the same channel need the same PSK to exchange messages.

Quiet Client (Muted Client)

A client variant with limited rebroadcast or chat behavior that helps conserve airtime.

See also: Role (Device Role)

Rebroadcast

Relaying a received packet onward. The behavior is controlled to minimize duplicates and loops.

See also: Rebroadcast Logic

Rebroadcast Logic

The rules and filters that decide whether and how messages are relayed, including deduplication. It is critical when using bridges such as MQTT.

Region

The regulatory domain that determines allowed frequency bands and power levels.

See also: Band (ISM Band)

Repeater

A coverage-extending node that is not shown in the standard node list.

Role (Device Role)

The behavior mode of a node on the mesh.

• CLIENT - Standard user node for sending and receiving messages.
• CLIENT_MUTE - Client with reduced chat and rebroadcast behavior to conserve airtime.
• CLIENT_HIDDEN - Client that participates without appearing prominently in lists or interfaces.
• TRACKER - Role focused on position reporting with minimal chat.
• LOST_AND_FOUND - Special mode for recovery and identification scenarios.
• SENSOR - Publishes sensor or system telemetry.
• TAK - Integrates with Team Awareness Kit features.
• TAK_TRACKER - TAK-focused tracking role for position reporting.
• REPEATER - Extends coverage and is not shown in standard node lists.
• ROUTER - Extends coverage and is shown in node lists.
• ROUTER_LATE - Router variant tuned for later or delayed relays.

Router

A coverage-extending node that is visible in standard node lists.

ROUTER_LATE

A router role variant tuned for delayed or later relaying.

See also: Role (Device Role)

rp2040

A Raspberry Pi microcontroller used in some Meshtastic boards.

RSSI (Received Signal Strength Indicator)

A measure of received signal power.

RX (Receive)

Receiving data on the radio.

Sensor

A node role or device function that publishes environmental or system data as telemetry.

Serial

A USB or UART link used for CLI access and firmware flashing.

SNR (Signal-to-Noise Ratio)

A measure of signal clarity relative to background noise.

Spreading Factor (SF)

A LoRa parameter that controls chirp length. Higher spreading factors increase range and airtime while reducing data rate.

SWR (Standing Wave Ratio)

An RF measure of antenna and feedline match quality.

TAK / TAK Tracker

Roles that support Team Awareness Kit integrations, usually focused on position reporting with limited chat.

Telemetry

Periodic transmission of sensor, GPS, or system metrics from a node.

TX (Transmit)

Sending data on the radio.

UART

A hardware serial interface used for logging, CLI access, and debugging.

Uplink / Downlink

Directional terms often used around gateways and bridges. Uplink usually means mesh to server, while downlink means server to mesh.

VERY_LONG_SLOW

The slowest standard modem preset, intended for maximum range at the cost of high airtime.

See also: Modem Preset

Voltage (Battery Voltage)

A telemetry metric many nodes advertise to indicate power status.

Web UI

A local web-based configuration or status page exposed by some devices or firmware builds.

Wi-Fi

On supported ESP32 devices, Wi-Fi can be used for features such as MQTT bridging or a web UI.