51–60 of 67 posts
you can run SRSRan on a small self contained SDR such as the Seeve board. Throughput is not going to be good as a custom stack as it's unoptimised, though. https://rfnm.com/blog/introducing-seeve
It is better than NDA with Broadcom, but still...
Earlier quoted context omitted.
Cellular comms. are all complex, proprietary, closed standards by big telecoms companies. There are some projects trying to solve this: OpenRAN, OpenAirInterface, O-RAN Alliance. This project tries to build an open solution following O-RAN standards for RAN software. It is targeting telecom. companies for their Radio Access Network (RAN). Their infrastructure is divided into the Core Network (like a simple internet n…
Why can't I create an ad hoc 4/5g network between phones? Genuine question. It looks so closed and complex compared to more traditional comms like wifi or even ethernet.
Networking between phones, without a common base station, is hard. Harder than WI-FI, because identity is managed centrally and the frecs in use require a license to name some "simple" problems. Cellular comms are not designed to handle this kind of scenario.
There has been some work to add inter device connectivity lately, to support many interesting use cases. You can find more looking for "sidelink" or "PC5", but you will not find many phones that implement it.
It seems to be mostly focused in vehicular use cases in V2V and V2X scenarios
you can run SRSRan on a small self contained SDR such as the Seeve board. Throughput is not going to be good as a custom stack as it's unoptimised, though. https://rfnm.com/blog/introducing-seeve
The LA9310 has incredible specs, too, what a beast.
Have you done anything with its Network Listening feature? I'm curious if that's frequency flexible or if it's limited to a specific handful of common bands.
How have you found the NXP SDK, is it reasonably decent to work with?
Can I use this to run my own mobile network? Is there something like a blank SIM card which I could use for it? I don't need global coverage but is it possible to create my own BTS on a PC (with some antenna connected to it) and then have my own SIM card which I can insert into regular phone/device and have it connected to my BTS and connect to the Internet?
Yes, is simple enough to get started if you have access to the required hardware. You might able to operate in the n41 band (2.4GHz, like wifi) even without a license. Phones are nitpicky about network configuration (chippers, emergency calling and so on). I would recommend starting with a USB modem. Also setting your network PLMN to the 00101 (the testing one), as it usually gets preferencial treatment in UEs.
LTE didn't allow for it to be used as primary carrier, but NR-SA I think does.
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This is the tower side (RAN) not the phone side (UE). It's not clear who the audience is. I assume it's equipment vendors since running a real carrier on USRPs seems janky.
A few applications I could think of: - Testing of various kinds. You can get deep inside an OSS base station, inspect and debug things, but likely may not even look at the proprietary innards of a commercial BS. - Emergency connectivity when the backbone is broken, or did not exist. Most people would bring mobile phones anyway. - Study / teaching, like MINIX OS or trainer aircraft which you can take apart and inspect…
Something like this would've been useful in a couple remote networks that I worked on. Internet was easy to get with some ubiquiti wifi routers and antennae. Getting cell reception was a pain in the ass that involved setting up a repeater in the one spot of the valley where reception was kinda okay. I haven't looked into the project too much, but I imagine I could set it up to connect to a telcom tower and handle the wireless backhaul similarly to how I did the wifi.
Edit: An open implementation like this could lead to cheaper cells for large, concrete/metal buildings that typically have terrible reception.
Can I use this to run my own mobile network? Is there something like a blank SIM card which I could use for it? I don't need global coverage but is it possible to create my own BTS on a PC (with some antenna connected to it) and then have my own SIM card which I can insert into regular phone/device and have it connected to my BTS and connect to the Internet?
Yes and yes, although in most parts of the world it won't be legal when done via antennas. You can buy blank SIM cards from vendors like Sysmocom, which are preprogrammed but "writable" SIM cards. The important part is knowing the private key that is used to authenticate end user devices. Then you'll just need a decent SDR and it actually works fairly well for small test setups.
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What you suggest could be accomplished with mesh networking. GP is correct in saying the reasons are orthogonal to functional reasons. Phone systems have always been centralised like this. Billing is one aspect, but lawful surveillance is another.
With respect, if you think that mesh networking would have worked considering the scale and capacity needed, and relevant type of devices then I am afraid this is a case of not knowing what you don't know...
Earlier quoted context omitted.
Cellular comms. are all complex, proprietary, closed standards by big telecoms companies. There are some projects trying to solve this: OpenRAN, OpenAirInterface, O-RAN Alliance. This project tries to build an open solution following O-RAN standards for RAN software. It is targeting telecom. companies for their Radio Access Network (RAN). Their infrastructure is divided into the Core Network (like a simple internet n…
Why can't I create an ad hoc 4/5g network between phones? Genuine question. It looks so closed and complex compared to more traditional comms like wifi or even ethernet.
5G also has a peer mode, and I'm trying to figure out if it can be implemented in userspace or has to be done in firmware.
My idea is that peer mode would be useful for replacing walkie-talkie or mesh messaging like Meshtastic since everyone has a phone. The range is supposed to be around a mile.
Earlier quoted context omitted.
A few applications I could think of: - Testing of various kinds. You can get deep inside an OSS base station, inspect and debug things, but likely may not even look at the proprietary innards of a commercial BS. - Emergency connectivity when the backbone is broken, or did not exist. Most people would bring mobile phones anyway. - Study / teaching, like MINIX OS or trainer aircraft which you can take apart and inspect…
> Maybe very small local cells to improve connectivity in difficult landscapes (mountains, skyscrapers, underground) Something like this would've been useful in a couple remote networks that I worked on. Internet was easy to get with some ubiquiti wifi routers and antennae. Getting cell reception was a pain in the ass that involved setting up a repeater in the one spot of the valley where reception was kinda okay. I…
Can I use this to run my own mobile network? Is there something like a blank SIM card which I could use for it? I don't need global coverage but is it possible to create my own BTS on a PC (with some antenna connected to it) and then have my own SIM card which I can insert into regular phone/device and have it connected to my BTS and connect to the Internet?
[1] https://www.quantulum.co.uk/blog/private-lte-with-limesdr-an...
[2] https://www.quantulum.co.uk/blog/private-lte-with-limesdr-an...