Plain-language definitions for the MeshCore and LoRa terms you'll run into as you get on the network.
MeshCore and LoRa radio come with their own vocabulary. Here's what the common terms actually mean, without the jargon.
The server MeshCore observer nodes publish packet data to over MQTT. MeshTexas runs its own regional broker — see About: How It Works for how ours fits together.
A named group for broadcast messages — public (visible to anyone on that channel) or private (key-protected, invite-only). A device can be a member of several channels at once.
The most common node role: a client device that sends and receives messages but never relays other nodes’ traffic. Lower power draw, better battery life — the right role for a phone-paired handheld or pocket radio.
A unit of antenna gain, relative to a theoretical antenna that radiates equally in all directions. Higher dBi means a more focused beam — great if you need range in a specific direction, less useful if you need coverage all around a site. Typical LoRa antennas run from about 2 to 8+ dBi. See Antennas for a practical breakdown.
A unit of absolute radio power, referenced to 1 milliwatt. Most MeshCore devices transmit around +22 dBm. The relationship isn’t linear — every +3 dBm roughly doubles transmit power, but only nets a modest range increase, which is why antenna choice and elevation tend to matter more than raw power (see Antennas and Repeaters).
A routing strategy where every node rebroadcasts everything it hears, up to a hop limit. Simple and robust, but noisier on busy networks — the default strategy in some other mesh firmware.
One retransmission by an intermediate node on the way to a message’s destination. MeshCore supports paths of up to 64 hops, considerably more headroom than flood-routing networks typically allow.
Unlicensed radio spectrum set aside for Industrial, Scientific, and Medical use — no license required to transmit. MeshCore devices in the US operate in the 902–928 MHz ISM band.
Every MeshCore device generates its own public/private keypair on setup — there’s no account, registration, or central authority. That keypair is the device’s identity on the mesh, and it’s what encrypts your traffic end-to-end by default.
MeshTexas-specific terminology: a MeshCore device configured to forward the packets it hears to our broker, feeding the live map and analyzer. Not every node needs to be one — see Connect for what’s involved in setting one up.
A routing strategy where nodes learn and cache the best-known route to a destination, then send along that specific path instead of rebroadcasting to everyone. Cuts down on network-wide chatter compared to flood routing — MeshCore uses this approach.
A fixed, usually solar-powered node whose whole job is receiving and retransmitting to extend coverage — it doesn’t originate its own chat traffic. Elevation matters far more than transmit power for a repeater’s usefulness; see Repeaters. Interested in hosting one? See Host a Node.
An infrastructure node role focused on message storage — it holds onto recent channel history so a device that was offline can catch up when it reconnects, and can optionally relay traffic too. See Room Servers for the details.
“Received Signal Strength Indicator” — how strong an incoming packet was, in dBm. Roughly: -80 dBm is a strong link, -110 dBm is marginal, and anything approaching -130 dBm is close to the noise floor.
A node role built for one-way telemetry — periodically transmitting readings like GPS position, temperature, or battery level onto the mesh, rather than participating in two-way messaging.
“Signal-to-Noise Ratio” — how far the signal sits above (or below) the background noise, in dB. LoRa’s a bit unusual here: it can successfully decode packets even at a negative SNR, where the signal is technically weaker than the noise around it.