
LTE Base Station Software - vezycash
https://bellard.org/lte/
======
k0ngo
I'm a big fan of Fabrice Bellard, but there are other eNB and UE
implementations that are fully open source, like OpenAirInterface[1] and
srsLTE[2]

[1] [http://www.openairinterface.org](http://www.openairinterface.org)

[2] [https://github.com/srsLTE/srsLTE](https://github.com/srsLTE/srsLTE)

~~~
presscast
I'd be really interested in seeing a tutorial for how to set this up.

~~~
pgorczak
With srsLTE you just need to run the srsenb and srsepc processes with their
example configuration files while having a compatible SDR connected. If you
want to attach your own phone you need to have the right credentials of course
but an srsUE (also with the example config) would happily connect.

~~~
presscast
I appreciate the comment, but I think I need a _much_ lower-level tutorial! I
know practically nothing about SDRs or LTE.

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jacob019
LTE-U would allow for LTE in unlicensed spectrum. Do any current devices
support these bands? I would very much enjoy serving unlicensed LTE around my
home. I wonder how much effort it would take to provide VoLTE over a SIP
backend.

~~~
walrus01
Several hardware manufacturers for LTE last mile fixed wireless, WISP
equipment, have announced BTS and CPE equipment for LTE in unlicensed
5150-5850 MHz bands. Baicells and Telrad come to mind.

It's not for around your home but as competition for things like the Cambium
PMP450 platform and Ubiquiti's Rocket 5AC gen2 AP radios.

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alxlaz
I used this several years ago (five or six, I think? Maybe more) with some of
Ettus Research's USRPs. It's quite amazing. We used it for prototyping -- the
gear wasn't (or we couldn't get it to be) fast enough to replace "real" LTE
gear, but do bear in mind this was many years ago. But at the time, this was
basically the best way to experiment with, and develop solutions for LTE, in a
price range that was mostly affordable for a small company. I know cheaper
options exist today, but I don't know much about them.

And, of course, this warrants a shout out for Ettus Research's equipment. It's
pricey but if you can afford it, or if you manage to strike a bargain, you'll
love it. The higher-ups at the company I was working for at the time were kind
enough to let me spend several evenings there using the equipment for my own
hobby projects. I mostly used it with GNU Radio -- it worked without a glitch.

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excalibur
Kind of concerning what other uses this could be put to. Doesn't seem like a
big jump from here to a DIY stingray, soaking up all of the data from every
cell phone within range.

Of course, vacuuming up everything is probably a great way to get caught
quickly. For nefarious purposes it would probably more useful to selectively
target individual devices.

~~~
monocasa
IIRC, in LTE the devices verify the identity of the towers with a signature
check now too.

~~~
mrb
No, LTE devices will happily connect to any random DIY base station, without
any visual indication that this is taking place...

~~~
gsich
Maybe with GSM, not with LTE.

~~~
iwiririwo
LTE handsets connect to any base station, at least on physical layer and
management protocols. This is required for mutual authentication.

Some attacks abuse error indication prior authentication for location leaks
and denial of service.

Once the connection is established, you're good.

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howard941
Wow check out the prices for the hardware. By "wow" I mean I can't afford
this. Clearly not the Amarisoft stuff where it doesn't even list the price,
preferring that people contact them apparently knowing that I can't afford it.

Are there any sub-US$500 hardware platforms for LTE play?

~~~
jcims
Ettus makes very high quality hardware but you pay for it.

Looks like Lime Micro is a partner of Amerisoft, they have an SDR for $300 -
[https://www.crowdsupply.com/lime-
micro/limesdr](https://www.crowdsupply.com/lime-micro/limesdr)

The likelihood that it's going to work without substantial tinkering is pretty
low.

~~~
howard941
Thank you very much for the link. Tinkering is precisely what I'd like to do
with it, on the 70cm ham band if LTE is a bridge too far.

~~~
jcims
Heads up, seems folks aren't having great luck with the Lime SDR for ham
applications. Some comments in here -
[https://news.ycombinator.com/item?id=15301982](https://news.ycombinator.com/item?id=15301982)
and here explaining why -
[https://www.reddit.com/r/LimeSDR/comments/71q2qk/thread_on_h...](https://www.reddit.com/r/LimeSDR/comments/71q2qk/thread_on_hackernews_regarding_sdr_with_several/)

A counterpoint in the comments here -
[https://www.youtube.com/watch?v=u2KK49sJ3L0](https://www.youtube.com/watch?v=u2KK49sJ3L0)

caveat emptor i guess, good luck!

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sleepydog
To actually use something like this for transmission, would I need to obtain a
license for use of the LTE radio bands?

~~~
xfitm3
Femtocells operate legally, might be worth looking into what bands it uses.

~~~
wmf
Femtocells are probably legal because they're owned/controlled by the carriers
and thus they can use the carriers' spectrum.

~~~
rizwank
And have specific FCC reporting obligations - your address must be reported up
for e911, GPS tracking (to ensure the carrier owns spectrum there), etc.

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meuk
I usually love Fabrice Bellards stuff, but I have to admit that I don't really
understand the how and why of this project.

~~~
wolfgke
> I usually love Fabrice Bellards stuff, but I have to admit that I don't
> really understand the how and why of this project.

The "why" should be clear here: make money (see Amarisoft's website:
[https://www.amarisoft.com/](https://www.amarisoft.com/) ).

~~~
meuk
I see, but what has Fabrice Bellard to do with this? His association with
Amarisoft is unclear to me. Has he actually made something, or is this just a
'hey, this is cool'?

~~~
drmpeg
He's the co-founder and CTO of Amarisoft.

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gz5
I like this at concept level though am not qualified to dig into the
internals. A use case could be eith CBRS (soon open in USA)? Add a neutral SAS
and you have an IIoT solution with LTE type bandwidth, sans the monoploly
telcos?

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bootcat
Is the code available for this ? This has been out from bellard's site for
some time.

~~~
swatkat
Source isn't available; software has been commercialized:
[https://www.amarisoft.com/products-lte-ue-ots-sdr-
pcie/#netw...](https://www.amarisoft.com/products-lte-ue-ots-sdr-
pcie/#network)

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microcolonel
What I'd like to see is an open baseband implementation, including calling out
to more efficient DSP hardware, and some more substantial hardware frontend.
There is surely a patent minefield involved in using something like that, but
it'd be nice to have something in the open which you could at least license
those patents to integrate into a product, and provide a greater degree of
certainty as to what's inside to your customers.

~~~
pabs3
The Osmocom folks have a GSM baseband project. They are also looking into
reverse engineering the Quectel LTE modems that run Linux.

[https://osmocom.org/projects/baseband/](https://osmocom.org/projects/baseband/)
[https://osmocom.org/projects/quectel-
modems/](https://osmocom.org/projects/quectel-modems/)

