Skip to content Glossary
Last updated 2026-10-26
- 915 MHz
- Shorthand for the US 902 to 928 MHz band used by LoRa radios.
- Coax
- Shielded cable between a radio and its antenna. Loss per foot rises with frequency and falls with thicker cable. More
- Companion radio
- A mesh radio that pairs with a phone or computer app, which you use to read and send messages. More
- dBi
- Antenna gain compared with an ideal antenna that radiates equally in every direction. Gain reshapes the pattern; it does not add power. More
- dBm
- Power relative to one milliwatt. 30 dBm is 1 watt, 20 dBm is 100 mW, and every 3 dB is roughly double or half.
- Fresnel zone
- The football-shaped space around the straight line between two antennas. Keeping about 60 percent of the first zone clear keeps the link healthy. More
- IP rating
- Ingress protection code for dust and water, such as IP65. Says nothing about electromagnetic shielding.
- IPEX (U.FL)
- A tiny snap-on antenna connector on circuit boards. Fragile and rated for few connections.
- Line of sight
- An unobstructed path between two antennas. At 915 MHz, hills, buildings and dense trees block or weaken the signal. More
- LoRa
- A long-range, low-data-rate radio technique used by MeshCore and Meshtastic.
- mAh
- Milliamp-hours. Multiply by the battery voltage and divide by 1,000 to get watt-hours.
- MeshCore
- A LoRa mesh messaging system with companion, repeater and room server roles. Does not interoperate with Meshtastic. More
- Meshtastic
- A LoRa mesh messaging system with a large community and app ecosystem. Does not interoperate with MeshCore. More
- N-type
- A larger, weather-tolerant threaded connector common on outdoor antennas.
- Node
- Any radio on a mesh: a handheld, a repeater or a fixed station.
- Pre-shared key (PSK)
- The secret key a channel uses to encrypt messages. Anyone with the key can read the channel; default keys are public. More
- Region setting
- A firmware setting that picks the legal frequencies for your country. Set it to US before transmitting. More
- Repeater
- A mesh node, usually mounted high, that forwards messages to extend range. More
- Room server
- A MeshCore role that stores message history and delivers it to users who connect later.
- SMA and RP-SMA
- Small threaded antenna connectors. They look alike but do not mate; check type and gender at both ends. More
- USB-C Power Delivery (PD)
- A negotiation between charger and device over voltage and current. A USB-C cable alone does not guarantee enough power.