BRN404 vs BRN404X - US Cellular and other available carriers

So interestingly enough I had a customer in a pretty remote area with limited cellular coverage. Given this scenario, I figured the latest and greatest hardware (BRN404X) would likely have the highest chance of connecting. In this particular scenario, he did not have coverage right where he needed it unfortunately. Walking farther away maybe 1,000’ it finally did connect but only to T-Mobile at maybe 15% signal strength. However, a prior customer of mine/neighbor of his had a BRN404 device and that ended up connecting immediately right where he needed it to. I would of thought both BRN404 and BRN404X would of used the same carriers and even more so BRN404X would have more not less. In fact looking at the Cell Global Identity, it looks like the BRN404 connected to “US Cellular” carrier with 70% signal strength right where he needed it to whereas the BRN404X finally connected to T-Mobile at maybe 15% about 1,000’ away.

Am I missing something, should I start an official support ticket with Particle? I would of hoped BRN404X was compatible with more carriers, not less?

Do we expect BRN404Xs to be able to connect to US Cellular now or in the future?

Finally, I have to ask the question again… are we making any progress on adding Verizon as a support carrier on Ethersim? I for one would LOVE LOVE LOVE to see Verizon!


Hi @jgskarda - the distinction you are seeing is not between Boron 404X vs. 404 but rather between EtherSIM and our previous non-branded SIM. All Supply Secure products (with an X at the end) run on EtherSIM, and some previous versions did as well.

Regardless we are actively working on expanding cellular coverage for EtherSIM and are evaluating adding both Verizon and U.S. Cellular support in the near future. Once we have a specific timeline in place we will share details here.


Understood… thanks for clarifying and I really appreciate the explanation!

This is great news to hear and I very much look forward to hearing more details once you are able to share it! Nearly all my devices out there are in remote areas which both US Cellular and Verizon seem to have better coverage for. Exciting times are ahead! :slight_smile:


From what I can tell US Cellular is not an “officially” supported network. If a device is connected to US Cellular, is there any reason it would be “dropped” or “booted”. This particular device reference above connected with > 70% signal strength for multiple weeks but then dropped off the map. Customer has tried to cycle power several times with no success. Wasn’t sure if a carrier or Particle would boot a SIM card if it wasn’t officially supported or not. Unfortunately, as mentioned above, this particular area does not have T-Mobile or AT&T coverage but great US Cellular coverage.

For reference, I also just submitted a support ticket.