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by kotaKat 1155 days ago
Indoor CBSDs don't need a SAS. You are fully legal running a B48 eNB inside your home at low power without even touching the FCC.

I'm doing this with Open5GS and a Baicells Nova227 that's running at low power indoors as it's both an indoor and outdoor-capable unit.
1 comments
FrankPetrilli 1154 days ago
I thought I was the only one silly enough to do something like this! I've got a Nova 227 tucked away in a corner room of my home facing inwards connected to Magma (was Open5GS).

Did you run into the bug where the default Open5GS bearer rate limit (1Gbps) somehow triggers a bug in the Nova 227 and causes it to run super slow (~7Mbps down/100kbps up)? I found that setting its rate limit to anything else seems to solve the problem and I get 100Mbps/10Mbps with TDD2/SSF7.

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kotaKat 1154 days ago
Wait. IS THAT WHY MY 227 IS SO GODDAMN SLOW?!?

Holy hell you might have saved my lab deployment! I need to test this when I get home.

If you haven't, have you considered creating an issue on GitHub over this so they can track it?

BTW -- I've done some really, really cursed things. I actually had ported Open5gs running on one of those little $20 USB LTE modems as a joke on top of Debian. I think I made the world's smallest EPC...

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yjftsjthsd-h 1154 days ago
> ported Open5gs running on one of those little $20 USB LTE modems as a joke on top of Debian. I think I made the world's smallest EPC...

Aw, come on, you can't say that and not post a write up

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kotaKat 1154 days ago
Not going to lie, I was a bit inebriated when I did it so I don't remember the exact stuff involved; my hardest challenge was reflashing the stick's Debian install because I accidentally bricked it.

It involved the openstick hacking[1] to get Debian onto it, and from there because it was just a straightforward arm64 box I had to compile the correct version of open5gs and mongoDB to support it. Not technically complicated, just a hilarious "just because I can doesn't mean I should" project.

The stick itself backhauled onto my home WiFi network, so in essence any cellphone was talking to my eNodeB wired to the network, then over WiFi to the USB stick running Debian, then back over the same WiFi back onto my LAN and out onto the world.

[1] https://hackaday.com/2022/08/03/hackable-20-modem-combines-l...

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FrankPetrilli 1154 days ago
Ahaha yeah it bugged the hell out of me too. Near as I can tell, there's nothing wrong with the Open5GS S1AP message, so filing a GitHub issue isn't the way forward. I did speak with Baicells about it, but their response was sorta... Complex. tl;dr I'm somehow the first one to find it, and they probably won't be fixing it.

If you set the rate limits to ~200Mbps you should be able to achieve max throughput on your 227.

I've similarly run Open5GS on a few cursed systems - shame the OpenStick doesn't support band 48 (though, mine won't detect a SIM card anyway...) - I've snagged a few old Verizon MiFi models that happen to have B48 support in the interim, or my iPhone 11 which makes a good UE.

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