Liberated Embedded Systems

OFF-GRID COMMS - OPENCOM XL

Introduction

When you Google around about off-grid communications, a common theme emerges. Most options presented to you aren’t really off-grid. 4G internet connections, satellite communications, etc. Yes sure, they do work, but they are still operated by the Government or a private company. Where’s the fun (or utility) in that?

Imagine someone who, after you ask them how to get water off-grid, tells you that you should order bottled water online and get it delivered. It’s simply a different way of getting the exact same thing you had before, and it doesn’t make you any more off-grid or free from outside influences.

In the case of water, you build your own well. There is also a way to install & operate off-grid communications yourself, without relying on the Government or other companies outside of your control.

The openCom XL is a handheld digital radio which can be used for general purpose communication. Combined with openCom Companion (or Sideband for desktop), you can:

You can also perform audio calls and browse websites with Reticulum Meshchat.

All you need to be able to communicate is an openCom XL (or another RNode) on either side and a decent line of sight between the two points. Below, I give an example of a field test over two headlands I conducted with a friend.

Demonstration

Our test area in Cornwall was along the south coastline. I set up at Dodman’s point (green on the map), and I dropped my friend off at Killigerran Head (red on the map) on the way. The total distance between the two points was around 9.2 miles (14.8 km), a decent distance!

A map of the coastline

I was set up next to the huge cross at Dodman’s point.

A cross with my laptop and radio at the bottom

And my friend was ready at Killigerran Head. You can see Dodman’s point in this image, it’s the furthest headland, in the center of the horizon.

A laptop and radio sat on a bench

We fired up the radios then set the same channel and the spreading factor to 7 on each side (similar to the “medium range” preset on openCom companion). This gave us a link speed of 5.47 kbps between the two radios on the long range modem. We did not utilise the high data rate modem in the radios as the distance was too far for it to work reliably with our setup. Most likely the difference in height between the two points also did not help.

The data transfer speed is slow by modern standards, but it is perfectly adequate for sending texts, transferring small files and even having push to talk audio calls. All of which we tested of course. The audio call was somewhat difficult at times due to the high winds blowing in the microphones, but we could hear each other!

My friend also sent me a 240kb file, which took a couple of minutes to transfer but arrived without any issues thanks to the reliable software backing the radios.

At a signal strength of -107dBm, the radio could most likely have gone even further had we moved a short distance away from each other, and should have provided a similar data rate to what we recorded here.

All in all, our test was a massive success, and it serves as a great demonstration of the power of the openCom XL. You can buy one in my store here.

Join me, and experience truly free and off-grid communications. TECHNOLOGY FOR FREEDOM.