
OpenBSC: 3G Voice Works - mynameislegion
https://projects.osmocom.org/news/59
======
jdavis703
This reminds me of being a kid in the 90s trying to sort through all the
acronyms and cryptic messages trying to get Linux installed. Maybe 15 years
from now we'll be able to click a couple of buttons on a slick website and
have our own 3G network up and running.

~~~
userbinator
Not if the FCC and other regulatory agencies have anything to say about it...

But telecoms standards are certainly _extremely_ complex; mainly because they
are truly designed by very large committees with plenty of bureaucratic
process. I did briefly try to read through and comprehend all the 3GPP
standards in order to understand the whole system end-to-end --- from the
microphone of one mobile to the speaker of another --- but gave up pretty
early, and I'd consider myself pretty knowledgeable about the Internet stack
from HTML through HTTP, TLS, TCP, and IP, all the way down to the bits on an
Ethernet cable or the signals an 802.11b/g transceiver emits.

If you've seen the 802.11 standard, that's about the limit of what I can still
understand with a bit of effort. The 3GPP specs are in a similar style of
thick standardese, but around 10x denser and more voluminous.

Then again, I don't think it's impossible --- maybe if I had a lot more free
time and interest I could. After all, Fabrice Bellard wrote his own _4G_ base
station:

[http://bellard.org/lte/](http://bellard.org/lte/)

Some people can explain all the details of what happens when someone visits a
URL in their browser. Maybe Fabrice can explain all the details of what
happens when someone turns on a mobile, associates with a network, and makes a
call with it.

~~~
kbart
3GPP set is easily among the worst standards I've ever read. I often thought
that it was deliberately made so, in order lesser companies and individuals
would not be able to make their own baseband. Not to mention references to
proprietary documents.. I'm _very_ impressed that somebody managed to make a
working BS out of this. Still it's strange to choose 3g, 4g is much lighter
technology.

~~~
neeels
re "strange to choose 3g": as some operators even phase out 3G completely, we
can expect 3G base stations to be available cheaper than ever. That's only one
of the reasons: Osmocom started out from the security analysis perspective;
having 3G openly available is a benefit to the general public as well as small
business in various ways.

(The opening lines of
[https://osmocom.org/news/30](https://osmocom.org/news/30): "3G is dead, you
may think. From the perspective of large scale operators, that may well be the
case, but this is precisely the reason why Open Source support for 3G is
becoming increasingly interesting: when the focus for earning money shifts
towards LTE infrastructure, the threshold for setting up 3G networks is
becoming easier to surpass for everyone else.")

~~~
kbart
3g operates on licensed frequencies (sold for billions in some countries[1]),
so you won't be able to setup a functioning network anyway. Maybe in some 3rd
world country, in the middle of nowhere or a tiny femtocell..

1\.
[https://en.wikipedia.org/wiki/Spectrum_auction#Germany](https://en.wikipedia.org/wiki/Spectrum_auction#Germany)

~~~
ansible
And this is the thing that cheeses me off the most.

Look at the economic activity created around a "junk" wireless band: 2.4GHz.
It is junk because of absorption by water molecules, and that's why microwave
ovens use it.

Despite how crappy it is, and how much interference it gets, it is so, so
useful. WiFi, Bluetooth, and dozens of other protocols. We get so much use out
of it.

If some other bands were opened up in the same way for unlicensed use
(conforming to a TX power limit of course), we could create more and more
applications, especially if it was a bit lower in frequency to allow longer
range communication with reasonable power consumption.

But there's no space worldwide for that, because it has all been sold off or
otherwise provisioned. It is such a shame.

------
i336_
As someone who doesn't follow the cellular scene as much as I probably should,
the immediate question I ask is: what is the impact of this development work
from the security standpoint of (potentially stealth) voice/data interception
on ordinary telco-provisioned cellular devices?

I realize GSM implements horribly broken authentication schemes, that almost
all cellular devices out there implement GSM (and GSM fallback) in order to be
implementationally complete, and that it's subsequently trivially possible to
(near-transparently) take over arbitrary devices using reasonably inexpensive
hardware and a bunch of open software if you can jam the 2.5G, 3G and 4G
bands.

I'm just curious what the hurdles are to do this for 3G (and beyond), from an
academic security standpoint. There are obviously whole swaths of layered
encryption and so forth that would need to be dealt with, I expect that; and I
admit my total ignorance - and curiosity! - as to what that is.

I vaguely recall obtuse rumors that suggest the existence of privately-owned
3G implementation(s) out there that do what I'm describing. I'm curious if
this open-source work is lowering the barrier to the accessibility for this
sort of thing.

This is an important question - I recall reading at least one story (I think
from here) about the questionable legality of unsolicited cellular wiretapping
operations (done via GSM) that have been noted by the news media.

(As an aside, I think that open-source GSM implementations exist is kind of
neat - if you're ever in the middle of nowhere (or an equivalent setting) and
you can setup base stations, old GSM phones are hundreds of times cheaper than
CB radios.)

~~~
myself248
> what is the impact of this development work from the security standpoint of
> (potentially stealth) voice/data interception

I think those things already exist, the Stingray is just the most-publicized
of its ilk. Big price tags provide plenty of incentive for closed-source
implementations, or possibly just licensing something already made.

The open-source versions often serve to democratize or to remind, of the
possibilities that've existed for some time. I think it'll enable some small-
fish to do bad things that the big-fish have been doing for years.

------
droopybuns
Hsdpa will be the really exciting accomplishment. Congrats on this in-between
step!

------
WhitneyLand
Since not everyone knows the background/industry it might help to:

Add a simple overview explaining the motivation, goals, and ultimate value
created by Osmocom

Explain why you are working on 3G when it's not a new technology

Explain how everything is going to be free as you claim without running into
any IP / patent issues.

~~~
voltagex_
It's not that kind of website. OpenBSC and associated projects have been
around for a very long time.

They're working on 3G because it's the next logical step for where their
project is up to.

~~~
WhitneyLand
The main site doesn't have this info either from what I could find:
[https://osmocom.org](https://osmocom.org). Is there a better site?

You say it's been around a long time,but how is that relevant? They are
actively asking for support so it's good to get their ideas known.

Your response about 3g doesn't inform much. To the lay person 3g is old tech
so it's a natural question to want to know how it will help people.
Undeveloped areas without a lot of investment capital maybe? Why should we
guess?

~~~
vertex-four
Note that 3G is still current-ish around the world, and is often what you'll
pick up in rural areas many places. In my country, it's pretty much just major
city centres that have 4G, and many phones still exist which don't support it.
In my city, it's often incredibly difficult to pick up 4G because of granite
buildings.

Osmocom's goal is to create an open source implementation of mobile telecom
standards. An open source implementation would allow people and companies to
build non-encumbered mobile devices and telecom networks. This is important if
you think free software is generally an important thing.

Osmocom run a GSM network at CCC each year, allowing people to place calls and
send text messages to each other for free.

------
hackaflocka
Is this potentially an open-source self-hosted alternative to Twilio?

~~~
detaro
Not really. This is tech to create your own 3G phone basis station and
network, for a twilio clone you want something that connects to the existing
phone networks, and probably over some kind of internet protocol and not
wirelessly ;)

~~~
mynameislegion
Connects to the existing phone networks probably requires money and special
contracts with existing phone network providers.

~~~
toomuchtodo
As does using certain wireless spectrum. It _is_ easier to write a Twilio
clone (as in, it can be done with sufficient time and resources); you just
need to call bandwidth.com with your checkbook open and ask them to
interconnect.

------
bigpoppa
the FCC needs to allow citizen bank cellular spectrum

~~~
gst
Such as LTE-U?
[https://en.wikipedia.org/wiki/LTE_in_unlicensed_spectrum](https://en.wikipedia.org/wiki/LTE_in_unlicensed_spectrum)

------
mrsheen
It seems that this [https://www.amazon.com/Mikrotik-RB951G-2HND-5-Port-
Gigabit-W...](https://www.amazon.com/Mikrotik-RB951G-2HND-5-Port-Gigabit-
Wireless/dp/B00EQWUZM6) has all you need for much less $$ and time.

~~~
mynameislegion
That has nothing to do with 3G, it is just WiFi.

