Older blog entries for LaForge (starting at number 214)

Announcing the low-power, light-weight sysmoBTS

It hasn't been a secret that when I co-started a company called sysmocom more than a year ago, it was not about opening a webshop that sells cheap phones and DYI electronics kits to the larger community. Rather, it was to develop and sell exciting products surrounding Free Software and mobile communications.

There are of course the more or less obvious things to do, like system integration of OpenBSC and the related software on embedded systems, selling them as appliances including training, support and maintenance service.

However, we of course also want to more than that. Today it is my pleasure to say that the availability of our first BTS product called sysmoBTS has been officially announced.

See the news item, the product page and the data sheet for more information.

To make it very clear in the beginning: sysmoBTS is not an open hardware project. The schematics and layout files are proprietary and not disclosed publicly. Such is the FPGA bitstream and the layer1 inside the DSP.

However, any code running on the integrated ARM processor is available as free software. This includes a yocto/poky-built Embedded Linux distribution featuring u-boot, the Linux kernel (including all kernel modules!), the osmo-bts and OpenBSC software as well as many other Free Software packages.

We think this is a reasonable compromise between espanding a bit from our previous "BSC and above in Free Software" down to a "BTS Layer2 and above" divide. After all, if you use OpenBSC with a BTS from Siemens, Ericsson, Nokia or ip.access, you don't have access to the source code of anything running inside the BTS at all.

sysmoBTS offers some great new capabilities, such as integrating the BSC or even the entire osmo-nitb onto the ARM/Linux processor inside the BTS hardware itself, creating a less than 500gram, 10W power consuming autonomous GSM network.

I'm going to stop marketing here, but I thought it is one of the major milestones for sysmoocm and thus for what I've spent way too much time on in recent months - and thus deserves to be mentioned here on this personal blog.

Syndicated 2012-05-19 02:00:00 from Harald Welte's blog

OsmoSDR boards available for interested developers

I've posted about this on the OsmoSDR blog, so there's no point in copy+pasting it here.

There are still boards available, so feel free to order if you are interested in yet another exciting Osmocom embedded hardware/firmware/driver/software project!

Syndicated 2012-05-18 02:00:00 from Harald Welte's blog

Some follow-up on the Osmocom Berlin meetings

We've now had the first two incarnations of the Osmocom Berlin User Group Meeting. The start was great, and we had probably something around 10 attendees. Some were the usual suspects like the various Osmocom developers living in Berlin. But we also had a number of new people attending each of both of the meetings, which is good.

To my big surprise people are even flying in from other parts of Europe in order to be able to attend. Last time from Sweden, and for the next meeting some folks from the Netherlands have announced themselves.

To an even bigger surprise, the attendee from Sweden announced that he is working for an Ericsson research lab, and apparently they are using OsmocomBB quite a bit inside that lab. They think it's a great tool, and apparently nothing else with the same flexibility (i.e. full source code) is at their hands that can compete.

On the one hand it is surprising to see such a large traditional Telco supplier to start to use such amateur tools like OsmocomBB, which definitely have not had even a fraction of the testing (particularly with various operators in various countries) like the commercial protocol stacks.

On the other hand, if you think more about it, Ericsson is entirely a network equipment supplier today. They have spun off their baseband processor business to become part of ST-Ericsson, they have pulled out of Sony-Ericsson, sold their TEMS product line to Ascom and other bits and pieces to Tieto. So right now, if they need a MS-side protocol stack or engineering phones, they probably have to obtain what is available on the market. And that's unfortunately not all that great, as the products are either

  • Measurement devices aimed at mostly L1 testing / QA (Racal, Agilent, Rohde-Schwarz)
  • Trace mobiles primarily aimed at field testing (TEMS, Sagem OT) and while they provide traces they don't permit you to send arbitrary data or behave spec-incompliant
  • Mobile Phone development platforms (Qualcomm, MTK, Infinenon, ...) which don't necessarily give you the full source code to the stack, and are only available if you actually intend to build a handset

So all in all, the more I think about it, it is actually not too surprising that they ended up with OsmocomBB. It's free (as in free beer) and they get the full source code with it. You need a lot of skills and time to get it running and find your way around how to use it, but I guess if you're working in cellular protocols and embedded systems, it's not that hard.

Syndicated 2012-05-07 02:00:00 from Harald Welte's blog

Name that UART: April 2012

It's sort of a cheap knock-off idea stolen from the Name that Ware on bunnies blog: I'm going to post one picture every month about a UART that I found on embedded hardware. Unfortunately I don't have much to offer in terms of a reward for whoever finds the true solution ;)

In any case, every month there are devices that I'm looking into either out of my own interest, or because the work at gpl-violations.org requires it. In most of them, you can find a UART to get to the u-boot / Linux serial console.

So here is the device that I just took apart earlier today:

The location of the UART pads was obvious, after looking at the PCB for a very short time. The entire unpopulated U1 footprint appeared suspiciously like a UART level shifter for true RS232 voltage levels:

  • You can see two signals going directly to a small unpopualted3-pin header
  • There are two other signals coming from somewhere under the main SoC
  • There are capacitors (C440, C441) directly connected to the U1 for the charge pump

Syndicated 2012-04-09 02:00:00 from Harald Welte's blog

Prototype smart card chips in DIL-40 case have arrived

Finally, the first samples of the smart card chip (for the Osmocom CardOS project) have arrived. As opposed to the final smart cards, this one has been packaged in a DIL case instead of the usual thin credit-card sized plastic. The reason for this is quite simple: This way lots of I/O pins for debugging as well as JTAG can be accessible during COS development.

Here you can see the first incarnation of a veroboard connected to an adapter pcb inside an Omnikey smart card reader:

After confirming it worked, I soldered the wires directly to the adapter PCB, as can be seen here:

There is already a real PCB design that is currently manufactured, i.e. in a week or so there will be a picture of a clean, professionally-produced/etched PCB with all of the prototype pins exported.

In terms of the COS, I haven't done much more work than compared to the last posting, mainly due to a large number of other projects. But we will get there...

Syndicated 2012-04-09 02:00:00 from Harald Welte's blog

OsmoDevCon 2012 is over...

We just finished the 4th and final day of the OsmoDevCon 2012. It contained four days of in-depth presentations and discussions related to Free Software communications systems, most notably OsmocomBB, OpenBSC, OpenBTS, OsmoNITB, SIMtrace, OsmoGMR, OsmoSDR, rtl-sdr and many more.

I think it was a great chance to make sure the key developers involved with those projects are up-to-date with what everyone else is hacking on. I was especially happy with the presentations of Holger's smalltalk implementation of certain GSM protocols/interfaces, and it seems my small informal Erlang intro has raised some interest.

If anything, the 4-day conference has shown that there is a massive amount of work going on in the various different projects, and that it has clearly grown beyond anything that a single person could still be involved in all the sub-projects.

Personally, I'm happy to see what has grown out of this "we have a BS-11, let's see what we can do with it" that Dieter and I started in 2008. Now we're no longer talking about BTS/A-bis/BSC, but about SS7, MSC, TCAP/MAP, SCCP, HLR, Erlang, smalltalk, DECT, SIM/USIM, COS, SDR, GMR/Thuraya, TETRA and more recently also femtocells as well as NodeBs.

In the spirit of that 2008 presentation Running your own GSM network using the BS-11, Dieter Spaar has now demonstrated his talk on Running your own UMTS network, using NSN or Ericsson NodeBs. I'm really excited to see where that will take us - despite the fact that due to the 5 MHz wide channels, it's pretty close to impossible to get the experimental spectrum licenses that most of us have been able to get in recent years for our work.

As an outlook, over the remaining year 2012, I see progress in the following areas:

  • osmo-nitb will get a VLR/HLR split (async database access)
  • we will build a stand-alone osmo-msc with A interface
  • the signerl TCAP/MAP implementations will be used in production
  • OsmoSDR firmware will be completed, the hardware will start shipping
  • a new card operating system (OsmoCOS) will emerge
  • a UMA gateway will be implemented
  • a Free Software GPRS/EDGE PCU and RLC/MAC implementation will appear
  • last but not least, sysmoBTS will start commercial shipment really soon now

I'd like to thank our host c-base for having us block their conference room for 4 days, as well as all attendees who have travelled from all parts of Europe, but even the United States and Russia to participate. There definitely will be another OsmoDevCon, though we don't know yet at which point in time.

Syndicated 2012-03-26 02:00:00 from Harald Welte's blog

h-online article covering OpenBTS and OpenBSC

You can find a 3-page article about OpenBTS, OpenBSC and related projects available from the h-online web site.

Syndicated 2012-03-26 02:00:00 from Harald Welte's blog

Using a cheap (USD 20) DVB-T USB stick as SDR receiver for (not only) gnuradio

Fellow Osmocom hacker Steve Markgraf has been working on what now seems to be the cheapest way to receive real-world radio signals for PC-based SDR like gnuradio: rtl-sdr. RTL refers to the RTL2832U chipset frequently used in such devices. It can be used to obtain 2.8 Ms/s of 8-bit I+Q samples.

Below is a picture (courtesy of Steve) how the hardware looks like:

Syndicated 2012-03-18 01:00:00 from Harald Welte's blog

Osmocom GPS timing source with u-blox LEA6-T

Recently we have been looking for an inexpensive way to generate a high-accuracy clock source for E1 lines, as it is required by a number of classic BTSs that don't have a sufficiently accurate OCXO built-in.

Luckily, the Digium E1 cards like TE-410P have a timing connector, to which an 8.192 MHz signal can be injected. Unfortunately, there don't seem to be any OCXOs around for that frequency. That's where the u-blox LEA-6T comes into play: It has a configurable TIMEPULSE2 output that can generate any frequency up to 10 MHz. We use this in our board to generate 8.192 Mhz and want to feed that into the Digium card.

So all we had to do is build a small board that contains the module and connector for antenna input, clock output and the obligatory 2.5mm stereo jack for the OsmocomBB-style UART:

Thanks to Sylvain for doing the schematics/PCB design, and thanks to Pablo for writing the code to configurea and activate the 8.192MHz output.

Once the design is verified, the schematics + gerber will be available, as well as board from the sysmocom webshop.

Syndicated 2012-03-16 01:00:00 from Harald Welte's blog

Alcatel MTK phone UART pinout

The Alcatel OT-890D is a MT6573 based smartphone. It seems one of the UARTs is available on test pads as seen in this picture:

The voltage level is still 3.3V, so no fancy 1.8V gear is required.

During boot, the UART is first used at 19200 bps, where it prints the strings "MW01" and "MW02". I then switches to 115200 bps where it prints "READY", and finally switches to 921600 bps, where it seems to output some mixed binary/text messages containing AT commands and responses between AP and BP, as well as some debug information:

�Ue� � � T+CREG=2
'Ue"""      AT+EFUN=1
      SML: Load!_Ue""""""
                         SML: Load!hU("("("

I haven't yet investigated if the binary between the text is some standard HDLC framing or a TS 07.10 multiplex.

If anyone knows more about the boot process (MW01/MW02/READY) or the binary protocol, please let me know.

Syndicated 2012-03-14 01:00:00 from Harald Welte's blog

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