What Is LoRa? (For Beginners)

LoRa stands for "Long Range." It is a radio modulation technique from Semtech that enables very long range wireless communication at very low power, at the cost of low data rates - the physical layer beneath Meshtastic and MeshCore.

How it works

LoRa uses chirp spread spectrum - the signal is spread across a wide frequency band using a continuously sweeping chirp tone. This spreading gives LoRa extraordinary resilience to noise. A receiver can decode a packet even when the signal is far below the background noise floor - a capability nofew conventionallow-cost modulationradio schemesystems matches.offer. (Other spread-spectrum schemes, such as GPS, also operate below the noise floor.)

Key characteristics

• Range: 1 - 15 km typical; 30 - 50+ km achievable with elevated antennas
• Data rate: 0.2 - 22 kbps depending on preset - slower than a 1990s modem, but sufficient for text and GPS
• Power: Nodes run days to weeks on a small battery; 8active current is roughly 10 - 5030 mA activefor dependingnRF52-based onboards hardwareand 40 - 100+ mA for ESP32-based boards. Days-to-weeks battery life applies mainly to nRF52-class hardware; size your battery for your specific board.
• No subscription: Operates in the unlicensed 902 - 928 MHz ISM band in North America. No SIM, no carrier fees.
• License-free: Standard operation under FCC Part 15.247 requires no amateur radio license

What LoRa is NOT

• Not WiFi: Far slower, far longer range. No web browsing or streaming.
• Not cellular: No towers, no coverage maps, no subscription. Works anywhere two nodes are within radio range of each other.
• Not LoRaWAN: LoRaWAN is a specific hub-and-spoke IoT architecture. Meshtastic and MeshCore are peer-to-peer mesh networks. Same radio hardware, completely different protocols. See the LoRa Mesh vs. LoRaWAN page for the full comparison.
• Not Bluetooth or Zigbee: Those are short-range (meters). LoRa is long-range (kilometers).

Why 915 MHz?

The 902 - 928 MHz ISM band is the North American LoRa mesh standard because it is unlicensed under FCC Part 15, has better building and vegetation penetration than 2.4 GHz, has a low ambient noise floor, and yields practical antenna sizes (~8 cm quarter-wave).

The fundamental tradeoff

LoRa's extreme range comes at the cost of speed. A 50-byte text packet takes several hundred milliseconds to transmit. This is fine for messaging and GPS tracking - and impossible for voice, video, or large files. Design your use case around this constraint and LoRa delivers remarkable results.