So, you want to use LINC. What is it?

LINC is a series of parallel networks of low-power, off-grid mesh-networking devices that automatically route messages between users. Most of these devices are privately owned by individuals who use LINC, but many are built, deployed, and maintained by LINC in order to enhance the overall performance of these networks for anyone who wants to use them.

What is a Mesh Network?

Unlike typical communication technologies that use one or more centralized clearinghouses for messages (mail, email, texts, etc.), a mesh network gets messages from sender to recipient by “hopping” from device to device (called “nodes”). Each device in the chain blindly passes the note, like kids in a classroom. Even if someone nefarious tries to open a note that isn’t for them, they can’t read it because it’s encrypted with the same technology that protects your online banking. Only the intended recipient can open and read the note.

Powered by Meshtastic and MeshCore

The backbones of LINC are open-source and free protocols, Meshtastic and MeshCore, which run on many affordable devices. These devices range in capabilities and features, but the most basic ones pair to a cell phone and use the phone’s screen as the interface for the device. Don’t worry, the phone doesn’t need an Internet or cell network connection to do this.

The T-Deck Plus

If you want to ditch the phone altogether, there are also standalone devices that make this possible. The one we recommend to new users is the T-Deck Plus, manufactured by LILYGO. For around $80, this device features a touchscreen, backlit keyboard, SD card slot for offline maps, and a built-in battery that recharges using USB-C. As of this writing, it’s the best standalone device available for mesh messaging, but any device compatible with Meshtastic or compatible with MeshCore will work.

Choosing a Network

To use LINC, you can install either the free Meshtastic or MeshCore software on your device. While LINC supports and maintains nodes for both of these networks, they are not connected to one another. If you choose to install Meshtastic, you won’t be able to communicate with any MeshCore users, and vice versa. Experiment and see which network works better for you. If you have friends or family using LINC, find out which network they use so you can be sure to use the same one.

Meshtastic

If you choose to use Meshtastic, you’ll need to install the free Meshtastic software on it. Configure your device to use the following settings:

• Ignore MQTT: Enabled

• Frequency Slot: 20

• Node Info Broadcast Interval: 72 hours

• Store & Forward: Enabled

• Broadcast Device Metrics: Enabled

• Device Metrics Broadcast Interval: 1 hour

Default Channels

Channels are a little like chat rooms. By default, your device will include one default channel, called “LongFast” on Meshtastic or “Public” on MeshCore. Because every device has these channels, they aren’t private. Everything you send on the default channel is likely to be read by others. This can be helpful for broadcasting or receiving community communication, so we recommend keeping it.

Private Channels

If you want to create a channel just for people you know to use, you can give it your own name and encryption key. Then, share the name and encryption key with anyone you want to give access to it. Only those people will have access to messages sent in this channel. Think of it as your own private chat room.

Direct Messages

If you want to have a conversation with just one person, you can do that without creating a private channel. Just select them from your device’s “node list” or “contacts,” and you can send them a message. Your device and theirs will exchange encryption keys automatically, instantly making your conversation private. They can respond to you as well, and both you and they will have total confidence that nobody else on the network can read your messages.

The Magic of the Mesh

Mesh devices have a “line-of-sight” signal propagation, just like cell phones. They can’t pierce through the planet—even a hillside. That’s why using the mesh to get your messages across is so useful. You don’t need to have a direct connection to your intended recipient, you just need a connection to someone. That person then needs to have a connection to someone else, and so on, until eventually, someone has a connection with your recipient. The mesh will find a route for your message, and you don’t have to do anything.

Broadening Your Horizon

Because your “range” is dictated by your surroundings, it helps to send out your signal from as high up as possible. One way to do this is by putting another mesh device up high (like on a roof or a pole) with a solar panel to keep it charged up. This one won’t need a screen or keyboard since you won’t be interacting with it directly; it will just be acting as a repeater to forward your messages along. If it’s running Meshtastic, it also doesn’t need a high Hop Count; set it to 0 or 1, so its node info broadcasts won’t cause congestion on the network.

At LINC, we deploy this kind of node in strategic locations in order to support the network. If you have a really great location (like a water tower or a grain elevator) and are willing to let us put up a node, let us know!

A Note About Privacy

Many mesh devices, including the T-Deck Plus, have a GPS receiver antenna in them. The purpose of this antenna is to let you share your location if you want to. When this feature is enabled, your location will be shared on your primary channel, but not on your secondary channels. If you want to hide your location, just turn this function off and you will disappear from the map.

Note: GPS receivers don’t transmit any signals to GPS satellites. They only receive signals and use them to calculate their own position.