What Is LoRa and How Does Meshtastic Use It?

LoRa, short for Long Range, is the radio technique Meshtastic devices use to send data. It modulates signals as frequency sweeps called chirps, so small messages travel miles on very little battery power. LoRa only moves the signal between radios. Meshtastic is the software on top that builds the mesh, encrypts messages, relays them between nodes and connects to your phone.

What is LoRa?

LoRa is a patented method for modulating radio waves, owned by the chip maker Semtech. It works at the physical layer, meaning it defines how a signal is sent and received between two radios. Unlike Wi-Fi or Bluetooth, it doesn't define a full communication system on its own. LoRa was built around two goals, communicating over long distances and doing it with very low power draw, which makes it a good fit for battery powered radios that operate far from any infrastructure.

In the US, LoRa devices operate in the unlicensed 902 to 928 MHz band. Other parts of the world use different bands, such as 868 MHz in Europe, which is why Meshtastic radios have to be set to the correct region before they'll transmit.

How does chirp spread spectrum give LoRa its range?

LoRa uses a form of spread spectrum modulation. Each symbol is sent as a chirp, a signal that sweeps across a range of frequencies. Spreading the signal's energy out this way makes it highly resistant to interference, and a receiver can decode it even when it's very weak, sometimes below the background radio noise. That is how a low power handheld can be heard over miles where other low power radios would fail.

The spreading factor controls how long each chirp lasts. Higher spreading factors are slower but easier to hear at long distance, and lower ones are faster but need a stronger signal. Meshtastic bundles spreading factor, bandwidth and related settings into modem presets, and every radio on a mesh has to use the same preset to talk to each other.

What's the trade-off?

LoRa's range and efficiency come at the cost of data rate. It's built for sending small amounts of data slowly and infrequently. Picture Wi-Fi and cellular data as multi-lane highways that carry video, web pages and large files quickly, backed by towers, routers and plenty of power. LoRa is a narrow country road that reaches remote places on very little fuel, but only small vehicles fit, and they move slowly. A short text message or a set of GPS coordinates makes the trip easily. A truckload of video never will.

That's why Meshtastic does well with text messages and location sharing and can't carry voice calls or photos. Messages are short, and on a busy mesh they share limited airtime with every other radio on the channel.

Where does Meshtastic fit in?

Every Meshtastic device contains a LoRa radio chip. LoRa gives it the physical ability to send and receive long range, low power signals, but LoRa says nothing about how devices form a network, how messages are routed, how traffic is secured or how people use the system. Meshtastic, an open source project, fills in all of that. It encrypts your messages, breaks them into packets small enough for LoRa, manages how packets hop from node to node across the mesh, organizes radios into private and public channels, and connects to the app on your phone or computer over Bluetooth, Wi-Fi or USB.

You may also see LoRaWAN mentioned. LoRaWAN uses the same LoRa modulation but is a different network design, usually for large numbers of sensors reporting to central gateways that connect to the internet. Meshtastic runs its own peer-to-peer mesh protocol and doesn't need gateways, towers or an internet connection. Our article What is Meshtastic? covers the project itself in more detail.

What does this mean when you use Meshtastic?

Because LoRa at 915 MHz travels mostly in straight lines, your real range depends on antenna height, terrain and line of sight much more than on the radio's power. Our guide to maximizing Meshtastic range covers what helps most. Because the data rate is low, keep messages short and expect occasional delays on a busy mesh. And because all LoRa Meshtastic radios in a region speak the same language, devices from different makers work together. Our Walkie Textie pairs with your phone, the WisMesh Pocket v2 adds a screen, GPS and an external antenna, and the LILYGO T-Deck has its own keyboard so you can message without a phone.

Common questions

Is LoRa the same thing as Meshtastic?

No. LoRa is the radio modulation that carries the signal between devices. Meshtastic is open source software that runs on LoRa radios and turns them into an encrypted text and location mesh with a phone app. Other systems, such as LoRaWAN, use LoRa in different ways.

Can Meshtastic send voice or photos?

No. LoRa's low data rate is what gives it long range on little power, and it's far too slow for voice or images. Meshtastic carries short text messages, location, and small bits of sensor and telemetry data.

What frequency does LoRa use in the US?

Meshtastic radios sold for the US use the 902 to 928 MHz band, often called 915 MHz, which is open to unlicensed use within FCC Part 15 limits. Europe uses 868 MHz, so check that a radio matches your region and set the region in the Meshtastic app before use.

Does LoRa need internet or cell service?

No. LoRa radios talk directly to each other over the air. Meshtastic messages travel from radio to radio across the mesh without towers, internet or a monthly plan, which is what makes it useful as a backup when the phone network is down.

If you're setting up your first radios, The Meshtastic Starter Guide takes you from a sealed box to a confirmed working message on the mesh.