
A 4G LTE base station running entirely in software on a standard PC - fanfantm
http://bellard.org/lte/
======
3amOpsGuy
Wow, it's from Fabrice Bellard of QEMU and ffmpeg fame, excellent.

~~~
hbbio
Not only that, but jslinux, qemacs, tcc. All by himself. He might be THE best
software developer on earth!

~~~
wbhart
Don't forget the singlehanded pi computation record. This guy is a serious
heavyweight.

~~~
kamaal
And also don't forget he is just 40!

~~~
thibaut_barrere
And that he coded LZEXE at 17 :)

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DigitalSea
Fabrice Bellard is a genius. Seriously, this guy may just be one of the, if
not the best software developers around. The very fact Bellard seems to like
tackling heavily technical challenges and sharing his findings is why he's the
great developer he is. This is impressive.

~~~
swah
He'd only have to write a web framework to ruin his reputation!

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tobiasu
Actual hacker news on Hacker News!

~~~
kamaal
Unfortunately actual hacks are scanty too!

How many people do you know can do all this. There are a few threads being
posted these days about side projects/extra income projects/failed ideas.
Nearly 99% of all ideas were designing HTML pages. Simple MVC apps.

How many things related to hard core development do you see these days?

Those people who do real hack work, pretty much keep silent and to themselves.
Don't harp, tweet or blog every two minutes.

~~~
TazeTSchnitzel
While this stuff is very interesting, websites and software can also be quite
interesting feats. Although I would agree many that you see here really
aren't.

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asg
I was pleasantly surprised to see the LTE specs are freely available. Large
consortium specs of this nature seem to be quite expensive. (cf:
<http://www.iso.org/iso/home/store.htm>)

Wonder what the patent licence situation is with the LTE specs?

~~~
mindjiver
LTE (as with most 3GPP specs) are heavily patented. All patents are available
under FRAND licenses however.

~~~
cma
Software isn't patentable in the EU, and this is a software radio
implementation...

~~~
pbhjpbhj
Software that has no 'technical effect' (though details of the specific test
have changed a few times) are not allowed. Many many valid [in respect of
patentability of the subject invention at least] software patents have been
grantd by the EPO and EPC member nations.

Because business methods aren't patentable in Europe many USPTO granted
patents have no technical contribution that is not excluded from
patentability.

tl;dr, it's complicated but your statement is false.

[http://en.wikipedia.org/wiki/Software_patents_under_the_Euro...](http://en.wikipedia.org/wiki/Software_patents_under_the_European_Patent_Convention)

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sandGorgon
I wonder why this was not developed/contributed to the GNU Radio toolkit
(<http://gnuradio.org/redmine/projects/gnuradio/wiki>) .

~~~
heretohelp
Because it's Fabrice Bellard.

Look at his ouerve, he doesn't bother integrating any of his projects into
anything else, or put more charitably, dance to the politics of other peoples'
projects.

I don't blame him. Contributing to GNU projects as an outsider is a PITA.

~~~
beagle3
It's more than that, I think: I've worked with people of his caliber in other
fields, and I can appreciate that they need to work at their own pace.

e.g., if he submitted QEMU as a patch for bochs, and it was rejected (for
whatever reason), does anyone think his time was better spent fixing that
patch?

He produces ingenious, high quality code, and does so at an unbelievable rate
(note, none of his open source projects is related to his day job as far as I
can tell - except perhaps the ASN 1 compiler).

I think he is arguably optimizing his contribution to society, and I hope he
keeps doing that. Let people who can't produce the core do all the
integration/politics/detail stuff.

~~~
lazyjones
What does he do for a living? I can't find anything about it on the wikipedia
page, his personal page and the blog page about his achievements - strange.

~~~
sounds
Although my information is somewhat dated, he lives and works in Paris for
<http://www.netgem.com> \- ffmpeg makes their boxes top-notch.

It's worthy of note that his free software makes him plenty of money.

It's also no surprise that he doesn't feel the need to write about himself.

~~~
sandGorgon
Seems that netgem has a history of GPL violations
(<http://roundup.libav.org/issue678>). Not sure what came out of that.

~~~
btbuilder
Looks like negligence rather than willful violation (last mentioned in 2009)

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ssdsa
Cool, it's from the same author (Fabrice Bellard) who coded the PC emulator in
Javascript: <http://bellard.org/jslinux/> ("How much time takes your browser
to boot Linux?")

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agumonkey
The higher the genius, the simpler the webpage.

~~~
kamaal
Bjarne Stroustrup says about this too.

Also have a look at Larry Wall's web page: <http://www.wall.org/~larry/>

~~~
agumonkey
My favorite example is <http://okmij.org/ftp/>

Quite beautiful.

~~~
scott_karana
Agreed, but something about his top navigation bar made my "Google Adwords
Section, Ignore This" heuristic go off.

~~~
agumonkey
Now that you mention it..

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sp332
I wonder if this could easily be combined with the recent hacker cell
networks, like ShadyTel <http://www.youtube.com/watch?v=QF4NjbIEbW8#t=64s> and
NinjaTel <http://www.youtube.com/watch?v=r83PKVXJ_K0>

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willvarfar
Very neat. Shame that 'interested companies can contact me'.

Would be fun to know how such base-stations - when attached to antenna - can
be used to spoof things and perform attacks. Lets hope that comes up at some
blackhat conference soon...

~~~
RachelF
Yes, it is a big shame that this is not open source.

I wonder how much he plans on making from this?

~~~
wr1472
I hope he makes a shed-load from this. I wouldn't begrudge him any of it,
given his contributions to the software community to date.

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mtdev
Neat, however, software for base station are not provided and interested
companies can contact the site owner. Pretty cool that this is allegedly
running on a software defined radio kit which can be had for only ~$2000 (a
bargain).

~~~
bostonvaulter2
Is there a reason that this Low-Cost software defined radio wouldn't work
($30)?

[http://www.amazon.com/Newsky-Receiver-Low-Cost-Software-
Defi...](http://www.amazon.com/Newsky-Receiver-Low-Cost-Software-
Defined/dp/B008DCBS94/ref=sr_1_1?ie=UTF8&qid=1346664377&sr=8-1&keywords=software+defined+radio)

~~~
xradionut
Because you are comparing two different categories of radios. There is a big
difference between a very cheap receiver and a high quality, wide bandwidth,
customizable transceiver. A bad automobile analogy would be a Yugo vs
Peterbilt.

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pagejim
Wonder how RealTime it is? Encoding/Decoding of data/signal as per LTE specs
is a multi-step process with lots of maths intensive operations.

Normally, custom made Baseband DSP processors are used for this kind of stuff
which contain special HW Accelerators for this kind of intensive computing.

Would be really interesting to see how he has implemented it and how practical
is it.

~~~
jlouis
Had it been somebody else, I would have pondered on the truth of the claim.
But Mr. Bellard... that is another thing entirely.

My guess is that he does have certain limitations, for instance the amount of
connections he can manage and so on. But I do think modern hardware can be
made to perform well if you know what you are doing. There are many ways to
generally implement the DSPs on a modern PC that would be fast enough.

Also, a guess is that one of the reasons DSPs are preferred is that they have
a better power profile. You don't need that for testing purposes.

All in all, I think it is a great project.

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hobbyist
I have a question here.. No one doubts the genius of fabrice bellard.. Someone
in the thread rightly commented him as a polymath.. Fabrice sticks to C and
loves the language to the core.. I often hear the FP folks saying that ppl who
are inclined towards math love to program in lisp/scheme/haskell/clojure..
Fabrice Bellard being a math genius has no project written in any of these
languages.. Why so? I understand it is personal taste but there got to be deep
reason also

~~~
marshray
Several of his projects show he has an affection for applied number crunching
and low-level programming. C lives right at the intersection of these domains.

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nathell
Fabrice Bellard is one of the guys I dream of one day achieving the level of
productivity of.

~~~
trigger
Productivity and sheer balls. My on-the-side projects are pathetic compared to
what this guy does. Even a quick glance at one of those LTE specs is enough to
scare me a million miles away from a project like this.

~~~
mindjiver
Knowing how many people it takes to develop a eNodeB is even more impressive.
Normally it would be n * 100 engineers (or even n * 1000) working on these
projects.

~~~
agumonkey
F.Bellard should write books, or tutor graduate students, his view of things
must be uber interesting

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mhd
Considering that this is from Fabrice Bellard, I actually was quite
disappointed that this isn't _really_ software-only, i.e. uses the side effect
radio waves generated by some standard hardware to do it. Talk about high
expectations…

~~~
claudeshannon
Not sure what your comment means. Did you want a software EM field?

~~~
mhd
I was referring to <http://bellard.org/dvbt/>

~~~
elteto
You can't generate an electromagnetic field _just_ from software!! At some
point you need a physical medium to accomplish that. In the case you point out
he uses the DAC hardware on a graphics card to generate electric signals,
controlled by software. Not really sure what you meant.

~~~
marshray
That's like saying "you can't calculate pi _just_ from software". We're
willing to presume the presence of some type of general-purpose hardware when
we talk about software.

Some of his projects require only the use of commodity hardware of the type
sold at Walmart. That's categorically different than something that requires a
custom built software defined radio transceiver.

That said, this project looks pretty cool.

------
ippisl
While it's a big technical achievement, in a world when companies are talking
about 4G LTE bill of materials of $50 [1] for a picostation(roughly 20mhz) and
vodaphone setting targets for $100(my guess for a full device) , where does
this fit in ?

[1][http://www.rethink-wireless.com/2010/09/07/picochip-
femtocel...](http://www.rethink-wireless.com/2010/09/07/picochip-femtocell-
bom-50.htm)

~~~
konstruktor
This aligns very well with the values of hacker culture: learning, exploration
and enabling others to do the same.

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swalsh
This is cool, but I would assume he's violating any number of patents in order
for it to work properly. (perhaps that's why it's closed source?)

~~~
cma
Software isn't patentable in the EU.

~~~
pbhjpbhj
You're wrong
[http://en.wikipedia.org/wiki/Software_patents_under_the_Euro...](http://en.wikipedia.org/wiki/Software_patents_under_the_European_Patent_Convention).

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sargun
Fabrice Bellard is to the FLOSS world, as Elon Musk is the entrepreneurship.

------
Jemm
As cool as this is, the title is a bit misleading. This setup requires a "low
cost software radio frontend" costing about $2000 and the author is using a
high end i7 processor.

Still a very cool use of SDR and probably considerably cheaper than the
alternatives.

~~~
frankydp
$2k is exceedingly cheap in the cellular space I would guess. So, the title
would only be misleading out of context, in which Fabrice assumes you will
find your own context, because he is to busy saving the world with code.

Also agree this is very cool use of SoftRadio.

~~~
rsync
Exactly. Go on ebay and search for "3g base station" or "cdma test" and so on
... low to mid 5-digit price tags for old equipment. Even the iden bases
(nextel, etc.) are still fairly expensive...

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bonaldi
Is it possible to do something similar for 2G/3g?

~~~
muzaffarfh
There is an existing project called OpenBTS,
<http://wush.net/trac/rangepublic>

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hobbyist
As the documentation says, all the processing from physical to protocol layers
is done by the PC. Could anyone experienced in wireless technologies explain
what is the software radio frontend worth 2000$ actually doing?

~~~
wmf
A USRP costs almost $2,000 because it is completely general-purpose, modular,
and customizable. It's more flexible than you really need, but if you're doing
a one-off project it's cheaper than designing a custom radio.

~~~
hobbyist
so right now the only use of it is to get the raw packets from ethernet,
convert to analog with required power and just release it over the metal? I
may be wrong here.. not an RF expert

------
OllieJones
Cool! The wall around another walled garden starts to crumble! How many years
before the carriers themselves start using open source code in their
infrastructure because it's more reliable and robust?

~~~
sbierwagen
This particular garden has legal walls: 4G radio frequencies are licensed.
Transmitting on them without a license can (depending on circumstances) result
in jail time.

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dicroce
Fabrice Bellard is one of my programming hero's.

1) FFMPEG 2) TinyCC 3) jslinux

------
superuser2
I thought the frequencies necessary for LTE in the US are licensed exclusively
to carriers? Or does LTE tolerate different networks on the same frequency?

~~~
claudeshannon
You're right. This would be in violation of FCC regulation as it would
interfere with a pre-existing network at 2600 MHz.

~~~
nolok
The guys is french living in France for a french company. I doubt he cares
about FCC regulations.

~~~
sbierwagen
France also, you will be unsurprised to hear, has cell phones, and laws
regarding them.

[https://en.wikipedia.org/wiki/International_Telecommunicatio...](https://en.wikipedia.org/wiki/International_Telecommunication_Union)

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smartkids
re: his appeal to "interested corporations"

Does he need money? One would think he probably has a pretty good day job
already. But if he really needed it in order to continue writing software, I
would bet many people would be willing to contribute to a "Bellard Writing
Fund". His contributions to open source are really in a class by themselves.

~~~
sbierwagen
Individual persons can't deploy their own LTE base stations, unless they've
got a couple million in their pocket for the radio frequency licenses. The
only way this will be available to the consumer is if a telco produces it.

~~~
smartkids
Thank you. I knew there must be a reasonable explanation.

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ajays
I'm clueless about the underlying legalities/politics, so was wondering: could
something like this be used to provide connectivity in an area without 4G (but
with an Internet connection)? In other words, could I (an average Joe) set up
my own "cellular hot spot" and offer a better quality signal to people in the
neighborhood?

~~~
wmf
Basically no. All the spectrum that phones can use is already owned by various
companies.

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kamaal
I always think how these hackers manage to do it. If you look at the projects
in his homepage they vary across domains.

How do they manage to stay motivated, how do they learn all the stuff they do.
And if I'm not wrong they do this apart from their day jobs.

Projects on his page are inspiring.

~~~
hobbyist
No doubt he is a genius, but what has made him excel is discipline. Try to
look at the documentation of the tools that he created for this project, you
will understand what I mean :)

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peterhajas
Fabrice Bellard does it again.

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st3fan
This would be more interesting if it were an open source project.

