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OpenLTE: An open source 3GPP LTE implementation (sourceforge.net)
219 points by sinak on July 1, 2016 | hide | past | web | favorite | 64 comments

Fascinating that someone is clueful enough to write an open source 3GPP LTE implementation ... yet clueless enough to host it on sourceforge.

Huh. Didn't know this. Thanks!

I did read that and I think it was posted here too, but a lot of the comments were on the line of "that's commendable, but the name is already tarnished."

Shame really.

They did a pretty good job on Slashdot so far, and I think the community response has been rather positive. Hopefully they can turn SF around, as well. GitHub is great, but it's good to have competition to avoid monocultures.

It is my understanding that they haven't done much at slashdot as the issues with sourceforge were much more pressing.

As such I haven't seen any changes occur at slashdot since the take over. I've only seen the slow, steady decline of slashdot continue. Which is unfortunate because every once and a while you see the low UID people make some stellar comments and it reminds me why I stick around despite vastly superior alternatives like hackernews.

Oh wait, they bought Slashdot too? I thought that was still owned by Dice.

Why should the name matter? The owners, the intent behind a thing, how it is run. That is what matters.

Or maybe they don't care/it doesn't matter? Somehow I doubt anyone who knows this stuff is going to be the type to be just downloading installers and running them.

There is no reason not to use SF.

Haha that's so damn true.

Fascinating that someone is clueful to write a whole 142 characters of derogatory commentary ... yet clueless enough to somehow consider sourceforge to be something bad.

Seriously, that was an utterly unnecessary comment.

Anyone working on any "ad hoc GSM/LTE" startups, or developed any business models around them? This technology is very interesting but I'm puzzled about what I would use it for.

There was a GSM-to-VoIP node based on a femtocell but the company making it apparently abandoned the idea before shipping very many, if any at all. I suspect the telcos had a small freakout.

In theory one can be transmitting on licensed spectrum inside the home without permits, but I suppose the telcos never envisioned a "3rd party femtocell" that wasn't connected to their services. So I imagine they were faced with drowning under deluge of telco lawyers.

Still, that was a brilliant idea. I think the product was eventually pivoted to shipboard applications. But, with unlimited voice calls on many plans, a roam-to-voip home base station holds less appeal.

Interestingly enough, there are places without any cell phone coverage where being able to enable a small cell site would provide communications. There are also many disaster scenarios where it would be helpful to have such a capability.

In how many places would this be legal though?

Indigenous communities in unserved rural Mexico set up their own open source based gsm networks and successfully pressured the central government after the fact to give them permission, and their efforts are spreading virally. https://rhizomatica.org/ http://www.wired.com/2015/01/diy-cellular-phone-networks-mex... They have occasional hackathons https://projects.osmocom.org/news/46

It's possible to get permits for temporary operation. People have done this at hacker conferences and at Burning Man for example.

The Burning Man GSM base station writeup was a fun read: http://openbts.sourceforge.net/FieldTest/

I'm the CEO of Fairwaves (http://fairwaves.co). We work with telcos, mostly in developing countries. But there are also customers who run our tech in indegineous communities in Mexico (https://rhizomatica.org/), on mining sites, ships and just in their labs as a test tool.

Providing GSM/LTE service in extremely remote locations in third world countries spurred the initial implementations of open source GSM stacks.

Other business models include intelligence and communications interception.

Few companies from German I think that it using OpenLTE & OpenIMS & Kamailio

http://www.ng-voice.com/ http://www.corenetdynamics.com/


IOT for industrial applications is where it's at. Currently only a handful of competitors in the field. Give me something fanless that can stand -40 to 80 degrees please.

Google's Project Loon is about the only one I know of...

Does anybody know some nice software radio materials? In form of lectures or lab exercises? I was always wondering about background of people which make feats like this. I have a degree in EE, oriented toward telecommunications but would not be able to produce something similar.

There is a (free) ebook I found, which takes a practical/exercise based approach to learning about SDRs [0]. It seems to work up from a basic comms background.

[0] http://www.desktopsdr.com/

Please have a look at our “Journey to GSM” series of articles. Our goal here is to introduce and demystify GSM and Software Defined Radio (SDR) technologies. There are only only two parts available so far, but more will come shortly. I’m the author and would be very much appreciate your feedback.

Here's the link to the first part: http://umtrx.org/journey-to-gsm-part-1-introduction/

Excelent tutorials please continue the good work. I like the fact that there is schematics freely available for UmTRX.

Maybe a dumb question but I don't see any mention of frequencies/power they use to test in the wiki.

I'm a little fuzzy on cell bands but I thought they were all restricted(lots of ham gear has cell bands explicitly locked out).

LTE in the unlicensed 5 GHz spectrum is coming soon (since the cell companies somehow only just realized that even if it's not pristine spectrum they also don't need to pay billions of dollars to access it) so there will actually be a legal way to use this in the future.

Just to make it clear - current "unlicensed" LTE technologies are LTE-U and LAA require an "anchor" channel in a licensed band. I.e. you still can't run it in your home unless you have a license for one other spectrum band. It's still limited to a carrier play, unfortunately. There is MuLTEfire tech by Qualcomm which can supposedly work completely in unlicensed spectrum, but it's proprietary and not very much is known about it so far.

Yeah no. This isn't LTE that anyone can set up, like WiFi. It's more designed to improve the speed of licenced LTE by letting LTE femtocells use unlicenced bands.

Also only the downlink is done over unlicenced bands. There's a competing standard that does uplink and downlink, but the all just augment a licenced LTE connection.

Any details on handset availability (even rumors)? I'd love to get my hands on a phone with an LTE transceiver that can operate in this spectrum range having an unlocked bootloader on the application processor.

Setting up a base station at elk camp and being able to use a regular cell phone instead of a dedicated amatuer or FRS/GMRS transceiver would be very cool.

Sorry, I don't know when this stuff is coming. In the mean time you could just use a wifi network with a SIP server for voice calls.

How is that going to work? I thought 5GHz had really poor penetration and attenuation. Will it trash wifi performance?

The cell carriers are mainly planning to use the 5GHz band for small cell indoor deployments (distributed antenna systems). The 3GPP and the Wi-Fi Alliance are going back and forth to ensure that if LTE and Wi-Fi networks are forced to share the same channel that it will at worst degrade the Wi-Fi performance as if there were another Wi-Fi network sharing the channel.

> ... if LTE and Wi-Fi networks are forced to share the same channel ... at worst degrade the Wi-Fi performance as if there were another Wi-Fi network sharing the channel.

All Our Shared Spectrum Are Belong to Us [32c3] https://www.youtube.com/watch?v=9cZxMg8shbA#t=1193

Unfortunately that's not true in implementation because LTE-U doesn't know or care about the wifi channel announce timings. By piping up whenever it wants to wifi throughput actually degrades more than 70% at minimum LTE-U duty cycle spec (50%) and up to almost completely, ~99% reduction, at max allowed LTE-U duty cycle (90%) spec.

No matter what they say this is a spectrum grab and LTE-U will degrade 5 GHz wifi to the point of being unusable.

Software defined radio such as hackrf can use this.

HackRF can't do it, because it's only half-duplex. But there are plenty of full duplex SDR devices - check out UmTRX and USRP B210. We're also developing a really tiny high performance SDR specifically for LTE - http://XTRX.io

Are you sure? hackrf usually can only provide half-duplex operation, and somewhat full duplex after certain tweaks. Still usb2.0 will be a limiting factor in this case. USRP boards will probably be a lot better.

HackRF/USB2 has enough bandwidth to do LTE, particularly since LTE can be configured to use between 1.4 and 20 MHz. I think the lack of full duplex or an FPGA on board would be the major limiting factors.

As mentioned above, half duplex of HackRF would be a limiting factor, unfortunately.

Obviously but you need to TX/RX on some sort of frequency otherwise it's not really a radio :).

I was just wondering if there's spectrum allocated for experimentation or if you'd be stepping on FCC rules by putting this into practice.

If you're running both sides on SDRs you should be able to tweak the frequencies in use. Several LTE bands neighbor and/or overlap amateur radio bands, so adjusting the settings a bit should allow you to move your test operations in to a range that is trivial to gain permission to use.

Bands 30 and 40 actually exist entirely within the amateur 33cm band, band 42 overlaps with 9cm, and band 46 overlaps with 5cm. Two of those also overlap with unlicensed spectrum, so there's extra room to play in that no one reasonable expects those bands to be clean anywhere people have electronics.

If you have cooperative endpoint devices you could also bodge other more common LTE bands in to amateur frequencies. Band 31 is just a 20 MHz drop away from fitting in 70cm, and cutting down the duplex spacing could make part of band 8 usable in region 2.

If you want commercial hardware to work it's probably best to stick to the first group, but if you're doing SDR on both sides and just want to experiment the second group should technically work.

Speaking of UEs (aka LTE modems) - there is an open-source implementation add well. See srsUE and srsLTE.

The BladeRF or the upcoming LimeSDR can handle this.

If anyone's interested in UE side, I recommend srsUE as a more functional open source implementation of LTE stack. There's also Open Air Interface, which has both Ue and eNB, but is less stable.

Are there any legal uses for this (in developed countries) - at least for someone who isn't a major telco?

There is a hope that 3.5GHz Citizen Band will make it possible for smaller companies to run LTE.

In a controlled environment (shielded enclosures), sure. But no broadcasting!

What's the easiest way to setup a shielded enclosure for hacking on something like this with an SDR?

It sounds like a bad response, but if you don't know, you shouldn't be trying. The risks and penalties for screwing up can be enormous and it's not something to take lightly.

I think your answer does not only sound bad.

Climbing and diving are easily lethal if you don't command your equipment appropriately. Would you recommend someone interested in practicing them to not even try?

Nonetheless, the point you make is important. Having said that, giving advise on how to avoid the dangers is what I think to be optimal.

Nooooooo why on SourceForge :-(

I just clicked on their cookie prompt and saw my browser being redirected to PayPal for some reason. Shut down the tab immediately and don't intend to check out the project at all.

Err, I have no idea what you saw, but it definitely wasn't your browser being redirected to PayPal - unless you somehow accidentally clicked on the "Donate" button.

Fortunately it's a .tar.gz rather than an executable, so the amount of harm SourceForge can do is limited.

Sourceforge's new owners claim[0] they stopped doing that stuff. I haven't checked to see if it's true but I know it's been discussed on HN before.


How so? They could drop an executable named "configure" in the tarball. I don't think they would, but they're not really limited by the format.

We're going to need a SHA-1 or something - they could just rezip the compromised binary.

Indeed. People interested in open source for this type of stuff are usually interested in security.

Recommend moving the project.

People who are interested in security would be verifying the pgp signature on the tarball. (What's that? It's unsigned?)

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