- UmTRX - lists.osmocom.org

by Alexander Chemeris

Hi all, Here is an update about a preselector frontend board on which we're working right now. Attached is an updated schematics of the board and 3D view of the board itself and the proposed way of mounting it to the main board. The github repository still contain an older revision of the schematics - I will update it a bit later when I get full project files from Andrey Sviyazov. https://github.com/chemeris/umtrx-schematics/tree/master/umtrx-v2-rxsel We would appreciate all constructive comments about the board design - from both RF and mechanical points of view. -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

11 years, 8 months

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Question about the name UmTRX

by Robin Coxe

I've been meaning to ask this question for a while and am just now getting around to it-- does the Um in UmTRX mean something significant in Russian? -- Robin Coxe | Close-Haul Communications, Inc. | Boston, MA +1-617-470-8825

11 years, 8 months

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Um Definition = Re: Question about the name UmTRX

by Martin O'Shield

> > Robin, > > > Um is the name of the GSM interface between the Mobile handset and the GSM > Network. > > Sincerely, > > > Martin > > > On Wed, Aug 22, 2012 at 2:18 PM, Robin Coxe <coxe(a)close-haul.com> wrote: > >> I've been meaning to ask this question for a while and am just now >> getting around to it-- does the Um in UmTRX mean something significant in >> Russian? >> >> -- >> Robin Coxe | Close-Haul Communications, Inc. | Boston, MA >> +1-617-470-8825 >> > >

11 years, 8 months

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Re: UmTRX preselector

by Andrey Sviyazov

2012/8/8 Jean-Samuel Najnudel - BJT PARTNERS SARL <jsn(a)bjtpartners.com> > Hi Andrey, > > Thank you very much for your reply. > > I understand your point of view regarding the ADF4350. I agree with you, > the ADF4350 still have quite good performances. I also agree that easier > software support is also important. It would just be a great news if we > could pass the GSM spec, at least as micro BTS. > > Regarding the GSM 1800 version of the selectivity board, it will not be a > problem to change the mixer and the filters. However, are you sure we will > be able to get the correct matching if we only change the passives ? Are > you sure we would not need to modify the PCB traces to get a good matching > for a 1800 MHz version of the board ? What do you think ? > Most of cooper would be 50 Ohm, so only FR-4 losses a bit higher. Also RF cables losses and so on, therefore 1800 parameters will be a bit worse, but it typical. About components, I've checked again and found that RF SAW filter for 1800 UL require coil at input (added). Best regards, Andrey Sviyazov. > > Best regards. > > Jean-Samuel. > :-) > > > > On Tue, Aug 7, 2012 at 7:27 PM, Andrey Sviyazov <andreysviyaz(a)gmail.com>wrote: > >> Hi Jean-Samuel. >> >> 1/ A few weeks ago, we discussed together about phase noise issues to be >>> able to pass the GSM spec. You explained HMC830LP6GE has much better >>> performances than the ADF4350. I know the HMC830LP6GE is a bit more >>> expensive but, as discussed together before, I really believe this worth >>> the extra cost. This would allow us to pass the macro or at least micro BTS >>> specs without the need for designing another slectivity board. This would >>> save a lot of work. Moreover, we espcially need this preselectivity board >>> for a micro or even macro BTS. In this use case, I really believe price >>> difference (like 40 or 50 USD) will be very low, especially compared to all >>> other costs of a mid-long range micro/macro BTS installation. Unless you >>> really disagree, I would really suggest to use the best performance >>> components as we reasonably can. >>> >> >> First of all, Robin said that ADF4350 already supported by UHD therefore >> it could save time to implement it for UmTRX. >> 2nd, I think that parameters differences isn't really as significant (few >> dB) as price and soft changing time cost. >> 3rd, it isn't last design and I am sure that we will change it for more >> functions, performances and for housing adaptations. >> Also I'm planing to buy HP4352 to design and measure PLL's, so of course >> I'll test HMC830 too, but now we just have to be sure that it will work >> properly and without risks. >> >> >>> 2/ In my deployment in Mayotte, I will also deploy GSM 1800 band base >>> stations because most of the spectrum I have is in this frequency band. To >>> avoid making another PCB for GSM 1800, could you design the board to allow >>> to populate either GSM 900 or GSM 1800 filters and matching passives with >>> the same PCB copper ? A single PCB would be easier to test and to maintain. >>> Moreover, this would save some costs as we will be able to order lager PCB >>> volumes. This could make a quite significant saving. Please let me know >>> what you think about this. >>> >> As I mentioned before, there are band specific components with same >> footprint. >> So, there are no changes required in PCB design for 1800 band, only BOM. >> For example, HMC485 instead of HMC483 and FAR-F6KA-1G7475 instead of >> FAR-F5KA-897. >> >> Best regards, >> Andrey Sviyazov. >> >> >> >>> >>> Anyway, thank you very much for this design. With UmTRX, this would >>> really make a cost effective and great performances base station. Thanks a >>> lot. >>> >>> By the way, as I am abroad, I may take a bit more time than usual to >>> reply to your e-mails. I really appologize for this and I will do my best >>> to reply as soon as I can. >>> >>> Best regards. >>> >>> Jean-Samuel. >>> :-) >>> >>> >>> >>> On Mon, Aug 6, 2012 at 5:07 PM, Andrey Sviyazov <andreysviyaz(a)gmail.com>wrote: >>> >>>> I've found first error: >>>> Missed AC block required for Vref pin of ADF4350. >>>> Also translated some components descriptions to English to avoid >>>> misunderstanding of Russian. >>>> All newest files here in zip. >>>> >>>> Best regards, >>>> Andrey Sviyazov. >>>> >>>> >>>> >>>> 2012/8/6 Andrey Sviyazov <andreysviyaz(a)gmail.com> >>>> >>>>> Sorry. >>>>> Zip file here :) >>>>> >>>>> Best regards, >>>>> Andrey Sviyazov. >>>>> >>>>> >>>>> >>>>> 2012/8/6 Andrey Sviyazov <andreysviyaz(a)gmail.com> >>>>> >>>>>> Hi all. >>>>>> >>>>>> Here first release of preselector project, schema and BOM. >>>>>> Any questions and suggestions welcomed. >>>>>> >>>>>> Best regards, >>>>>> Andrey Sviyazov. >>>>>> >>>>>> >>>>> >>>> >>> >> >

11 years, 8 months

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UmTRX/OpenBTS at the GnuRadioConference and OpenHardwareSummit

by Alexander Chemeris

Hi all, I've just got an approval from Tom Rondeau that we'll present UmTRX at GRC at the hardware session (we'll be added to the official schedule soon): http://www.trondeau.com/grc2012-dates/ We'll be also doing a demo session at the Open Hardware Summit, showing OpenBTS with UmTRX: http://summit.oshwa.org/ Come visit us there! -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

11 years, 8 months

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Fwd: [Discuss] OHS tickets are now available

by Alexander Chemeris

Thomas, Robin, Sylvain, If you want to attend OHS, I recommend you to get tickets NOW - they are ridiculously few of them left. ---------- Forwarded message ---------- From: Catarina Mota <catarina(a)openmaterials.org> Date: Sat, Aug 4, 2012 at 2:20 AM Subject: [Discuss] OHS tickets are now available To: The Open Source Hardware Association Discussion List <discuss(a)lists.oshwa.org> We have two types of tickets: • Starving Artist Pass: ($50) For artists, students, and non-profits • Summit Pass: ($75) Everybody else All passes include: breakfast, snacks, post-conference drinks, and an amazing gift bag from our sponsors. Please note that this year we will not be serving lunch at the conference, but we will be in the beautiful Chelsea area of Manhattan where there are many restaurants for you to choose from. Ticket types are not strictly enforced, so please exercise your judgment. Check out the speaker lineup: http://summit.oshwa.org/2012/07/23/2012-speaker-lineup Get your tickets: http://ohsummit.eventbrite.com More info about the summit: http://summit.oshwa.org/ Cheers, Catarina & Dustyn _______________________________________________ discuss mailing list discuss(a)lists.oshwa.org http://lists.oshwa.org/listinfo/discuss -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

11 years, 9 months

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Pletronics OHM4

by Alexander Chemeris

Hi, I've received 10pcs of OHM4048052GG010020-26.0M today. Andrey Sviyazov - could you measure their performance and test UmTRX with them? -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

11 years, 9 months

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UmTRX in action picture

by Alexander Chemeris

We need a picture of UmTRX in action for the Open Hardware Summit web-site. Andrey Sviyazov - could you bring your UmTRX (the one with an enclosure) to the hackerspace to make a picture of it with antennas? -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

11 years, 9 months

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LMS TxLO noise

by Andrey Sviyazov

Sorry, that was meant to be sent to the mailing list :) Best regards, Andrey Sviyazov. ---------- Forwarded message ---------- From: Andrey Sviyazov <andreysviyaz(a)gmail.com> Date: 2012/7/18 Subject: LMS TxLO noise Hi Thomas. Here forwarded my last e-mail with noise plots when I stopped work around it at first time, please see below. Please try to play around Tx PLL charge pump current (register 0x16) for better RMS phase stability. I think we should reach 1 degree or below. Alexander gave me the second UmTRX board and after checking and fixing all known hardware issues<http://code.google.com/p/umtrx/issues/list?can=1&q=&colspec=ID+Type+Status+…>I've got roughly the same LO noise plot. Possible Robin had no time to fixing all of our issues, so check them all please. And also check please what type of TCXO installed on your board. Best regards, Andrey Sviyazov. ---------- Forwarded message ---------- From: Andrey Sviyazov <andreysviyaz(a)gmail.com> Date: 2012/4/13 Subject: Re: LMS TxLO noise Hi all. There is progress with LMS PLL :) Pictures are attached here. t was discovered that 80 kHz spurs come from Ethernet, or rather from the ET1011. I unknowingly put the choke between transistor of 1V regulator and analog power 1V. As a result, the regulator has become unstable and oscillated 80 kHz with amplitude of 200 mV, which climbed into the LMS PLL. To correct this problem L46 should be replaced by jumper on all alfa version PCB's. Also I just played with current in the PLL loop, shown on the picture for clarity. Proved to be the optimal current 1,9 mA (you should write 0x93 in the register of 0x16). But, I think, for the RxPLL will be better use of the current 2.4 mA, because the nearest noises more important for Rx (you should write 0x98 in the register 0x26). Best regards, Andrey Sviyazov.

11 years, 9 months

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UmTRXv2 final project

by Andrey Sviyazov

Hi all! Here last version PCB of UmTRXv2. In the next e-mail I'll include project files and cheapest BOM for debug variant. I think it is final, because of nobody desire to say me any suggestions (except Robin). Best regards, Andrey Sviyazov.

11 years, 9 months

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DC Offset vs temperature

by Alexander Chemeris

Hi all, Thomas has discovered that DC offset calibration for LMS is drifting a lot with temperature changes and this has detrimental effect on the modulation accuracy: http://code.google.com/p/umtrx/issues/detail?id=31 One solution proposed by Sylvain is to tune modulation a bit higher using digital modulation, which should be straightforward with UHD which has digital mixer in FPGA. But I wonder what is a recommended solution for this temperature compensation for LMS in general. Srdjan, could you comment on this? -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

11 years, 9 months

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Plan for 10/100 Ethernet support for umTRX

by Robin Coxe

The Ettus UHD framework adopted for the umTRX only supports GigE (simple_gemac). A reworked, Wishbone-compliant 10/100 Ethernet MAC is included in the OpenRISC SoC project on Opencores. It has been ported to the Digilent Atlys board, which has a Spartan-6 FPGA. http://www.chokladfabriken.org/projects/orpsoc-atlys I'll begin the port of this Ethernet MAC (a cleaned-up version of the 10/100 core on OpenCores) to the UmTRX and test it on Close-Haul's SP-605 Spartan-6 eval. board. I'm not quite sure how long this task will take, but this feature falls into the "nice-to-have-but-not-urgent" category. -Robin -- Robin Coxe | Close-Haul Communications, Inc. | Boston, MA +1-617-470-8825

11 years, 9 months

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Improving LMS6002 phase noise

by Srdjan Milenkovic

Hi all, As far as I am aware, you are currently discussing how to improve LMS6002 PLL phase noise. Below are some inputs from my side which may help. Apart from playing with PLL registers we have two additional options. 1. Use clean TCXCO which provides 4 times higher reference followed by divide by 4 to generate PLL reference clock. Recently, we experimented with 30.72*4 MHz TCXCO. Dividing its output by 4 before going into LMS chip we have got improvement of 6dB in phase noise plateau region. 2. Current PLL loop filter has been designed to cover the whole LMS frequency range hence using kind of mid value for Kvco. We can customize the loop filter for a particular band. To do that we need to know frequency range China Mobile is looking for and reference clock you want to use (26MHz, 26*4/4MHz, ...). Please note that PLL reference clock does not need to be the same as system clock i.e. we can also use 30.72MHz, 30.72*4/4MHz etc. Best regards, Srdjan

11 years, 9 months

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OpenBTS with UmTRX

by Thomas Tsou

Google project hosting is currently read only for network maintenance. Here are general OpenBTS / UmTRX setup instructions. I'll post them when write access is restored. Download ======= UHD git://github.com/chemeris/UHD-Fairwaves.git fairwaves/umtrx-dboard OpenBTS git://github.com/ttsou/openbts-p2.8 umtrx Follow standard build instructions. http://files.ettus.com/uhd_docs/manual/html/build.html http://wush.net/trac/rangepublic/wiki/BuildInstallRun UmTRX Setup =========== Configuration of the LMS6003D is through the control script 'umtrx_lms.py', which is installed in '/usr/local/share/uhd/utils'. Calibration prior to operation is strongly recommended. Example setup for ARFCN 925: Initialization and auto-calibration: ./umtrx_lms.py --lms 1 --lms-init ./umtrx_lms.py --lms 1 --lms-tx-enable 1 ./umtrx_lms.py --lms 1 --lms-rx-enable 1 ./umtrx_lms.py --lms 1 --pll-ref-clock 26e6 --lpf-bandwidth-code 0x0f --lms-auto-calibration RX LNA and RXVGA2 selection and gain control ./umtrx_lms.py --lms 1 --reg 0x75 --data 0xf0 ./umtrx_lms.py --lms 1 --reg 0x65 --data 10 TX LPF control ./umtrx_lms.py --lms 1 --reg 0x34 --data 0x3e LO leakage cancellation (calibration data values may vary) ./umtrx_lms.py --lms 1 --reg 0x42 --data 0x67 ./umtrx_lms.py --lms 1 --reg 0x43 --data 0x89 TX/RX PLL charge pump current ./umtrx_lms.py --lms 1 --reg 0x16 --data 0x93 Tuning ./umtrx_lms.py --lms 1 --lms-rx-pll-tune 925.2e6 ./umtrx_lms.py --lms 1 --lms-tx-pll-tune 880.2e6 TXVGA2 gain to max and enable PA ./umtrx_lms.py --lms 1 --reg 0x45 --data 0xc8 ./umtrx_lms.py --lms 1 --lms-pa-on 2 Running OpenBTS ============== Follow standard instructions. http://wush.net/trac/rangepublic/wiki/BuildInstallRun Thomas

11 years, 9 months

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Running OpenBTS with UmTRX

by Alexander Chemeris

Hi Thomas, Could you hack together a quick guide how to run OpenBTS with UmTRX at the wiki? http://code.google.com/p/umtrx/wiki/RunningOpenBTS This should basically include which branch to use, what patches to apply (if any), and a script for umtrx_lms.py to tune LMS to the correct frequency. I was meaning to write this for about a week, but turns out it's very hard to allocate enough time to do that accurately. -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

11 years, 9 months

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Testing reception

by Alexander Chemeris

Andrey Sviyazov, You wanted to know how to plot received signal under Windows without installing Matlab or something as big and as expensive. Dmitri Stolnikov recommended to use a free version of Signals Analyzer software which should be very powerful. You could download it as "SA free" here: http://signals.radioscanner.ru/info/item1/ Dmitri says that the free version of SA could only import .wav files, so you will need to convert raw files into .wav files. My preferred way to do this is to use 'sox' command line utility like that: sox -r 270833 -e signed -b 16 -c 2 record.cfile record.wav Windows binaries of 'sox' is available from the official web-site: http://sox.sourceforge.net/ -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

11 years, 9 months

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UmTRX dual-channel Rx

by Andrey Sviyazov

Hi all. I found that both Rx divercity switches have zero state for A and B control inputs. Thus both LNA and LNA-D connectors are not switched to Rx inputs of the LMS's. To proceed Rx testing I suggest to set the next fixed states in the FPGA: DIVSW1_P = 1, DIVSW1_N = 0, DIVSW2_P = 1, DIVSW2_N = 0. In this case LMS1 will be switched to LNA connector, but LMS2 to LNA-D. Andrew Karpenkov, would you please to make this kind changes, until DIVSW will controled by host? Best regards, Andrey Sviyazov.

11 years, 9 months

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Attachment size

by Alexander Chemeris

Hi all, I've set maximum message size for this mailing list to 1Mb. This means that you can't send big files or images to this mailing list. If you need to do so - upload files to some external server and provide a link. Project members could use our project hosting, others could upload to some other public services. At the same time limitation of 1Mb should be big enough to allow you to post screenshots of your measurements, schematics pictures, etc. Please make sure that you send big files as an attachments, even if they are textual. Subscribers (myself included) sometimes work from GPRS/EDGE connections and downloading huge e-mails is a true pain. -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

11 years, 9 months

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Re: Dual-channel Tx

by Andrew Karpenkov

Hi All, I added one more RX and TX units and connected them to the second LMS chip. You can find fpga sources with full supply (both, receive and transmit) of dual channel at akarpenkov/dual-channel branch of github repository. Also, we need to make some changes in HOST code: - SR_RX_FRONT0 (base adress of RX0 frontend) was changed from 24 to 20 (dec) - SR_RX_FRONT1 (base adress of RX1 frontend) was added with value = 25 (dec) - SR_TX_FRONT (base adress of TX0 frontend) was changed from 128 to 110 (dec) - SR_TX_CTRL (base adress of control logic of TX0 channel) was changed from 144 to 126 (dec) - SR_TX_DSP (base adress of DSP TX0 unit) was changed from 160 to 135 (dec) - SR_TX1_FRONT (base adress of TX1 frontend) was added with value = 145 (dec) - SR_TX1_CTRL (base adress of control logic of TX1 channel) was added with value = 161 (dec) - SR_TX1_DSP (base adress of TX1 channel) was added with value = 170 (dec) - Setting register to program the UDP TX DSP port (16 + 1 in dec) are now 32 bit wide (udp dst0 port - lower 16 bits, udp dst1 port - higher 16 bits). I sent flash for FPGA to Alexander and he must publish files on the site soon. I should say, I have not tested work of the project. Please report any issues. Regards , Andrew Karpenkov

11 years, 9 months

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LMS6002D documentation

by Alexander Chemeris

Hi all, I've pushed more public documentation for LMS6002D to the repository: https://github.com/chemeris/lms6002-documentation FAQ should be very interesting for everyone - recommended reading. -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

11 years, 9 months

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Re: [rfc] git workflow model

by Alexander Chemeris

Hi, On Sun, Jul 15, 2012 at 8:48 PM, ☎ <Max.Suraev(a)fairwaves.ru> wrote: > Hello. > > I'd like to test new ML anyway so here is my question :) > > I've stumbled upon pretty interesting $subj at > http://nvie.com/posts/a-successful-git-branching-model/ (Russian translation is > available at http://habrahabr.ru/post/147260/ ). > > What do you think of it guys? Should we try to adopt it? Or at least document > whatever model we use now? I need some time to read the post, but in general it's a good idea to describe branching policy. -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

11 years, 9 months

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UmTRX prototypes cost

by Alexander Chemeris

Hi Jean-Samuel, Could you share the prices you get for UmTRX from your fab for this batch of prototypes and for the next batches? We have to understand the cost price to see what could we offer to customers. -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

11 years, 9 months

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UmTRX goes public

by Alexander Chemeris

Hi all, As UmTRX release gets closer, i want to gradually move all related documentation, discussions, news, etc to public. The plan is to move everything under the Osmocom umbrella, because it's a good neighborhood for UmTRX. Omsmocom.org server is somewhat overloaded now, so for the time being all git repos will stay at github and wiki and files will stay at Google Code. They will be moved to osmocom.org when they upgrade their server. Mailing list is not a big load, so the UmTRX public mailing list has been created as umtrx(a)lists.osmocom.org. Some of you already received subscription e-mails, everyone else is encouraged to subscribe as well. You could do that with the web interface here: http://lists.osmocom.org/cgi-bin/mailman/listinfo/umtrx Please use the public mailing list for all technical discussions from now on. "Project-mayotte" and "gsm-internal" are to be used for business and manufacturing related, private or other highly 533kr337 discussions. I'm going to publish schematics today together with some brief description of features. Public Lime documentation will be published as well. -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

11 years, 9 months

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UmTRX integration with OpenBTS

by Alexander Chemeris

Hi Thomas, If we get a UmTRX to you, could you make OpenBTS to run with it quickly, like before the end of the month? No matter how hackish the solution would be. We just need a way to start testing the hardware performance in a more real situation. Then we could target a cleaner solution. To recap - right now we could transmit on a single channel, and receive on both channels, but the control of LMS chips is done by an external python script. I.e. to tune and set bandwidth, gain, etc you have to run this script before claiming a device with UHD. -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

11 years, 10 months

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UmTRX timestamp bug Was: UmTRX integration with OpenBTS

by Alexander Chemeris

On Mon, Jun 18, 2012 at 5:32 AM, Thomas Tsou <thomastsou(a)gmail.com> wrote: > On Mon, Jun 11, 2012 at 7:12 AM, Alexander Chemeris > <alexander.chemeris(a)gmail.com> wrote: >> On Mon, Jun 11, 2012 at 4:08 AM, Thomas Tsou <thomastsou(a)gmail.com> wrote: >>> If the load drops down and the signal transmits, I wouldn't worry >>> about it for now. The likely condition is that there is a offset >>> between the initial arriving timestamp and the expected timestamp. >>> Because the receive timestamps drive the transceiver, the receiver may >>> run at 100% until the timestamp and expected value align. If OpenBTS >>> transmits consistently, then the system is in sync. >> >> Aah! Yes, we have some issue with setting the timestamp with UmTRX. >> E.g. I had to modify UHD examples which set timestamp to 0 on startup >> and rely on this later on. With my change they read the actual value >> of the timestamp and start from that. Could we do the same for >> OpenBTS? > > I'm running into this issue now, which was the reason I wasn't always > seeing transmit output. Workaround patch is attached along with the > corrected 'normal' rate GSM signal. Thanks for the patch! I think we could push it to the OpenBTS repom as it doesn't harm anyone? Sylvain - with your great debugging abilities, could you find the cause for this bug without too much trouble? To me it looks like the bug is in FPGA firmware, i.e. something went wrong with the VITA timer control when we changed frequencies of the DSP part of the FPGA. The bug is not critical, but is really annoying, because you have to change all UHD utils to avoid setting a timestamp before use. -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

11 years, 10 months

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UmTRX UHD branches clean up

by Alexander Chemeris

Hi all, I've cleaned up our git branches to make sure everyone are on the same page. Now a stable code (if could say so) is in 'fairwaves/umtrx' branch. I.e. you should build FPGA image, ZPU firmware and UHD host code from this branch. Other branches are topic branches, owned and maintained by respective developers for their very own purposes and you're not warranted from any consequences of using them, including, but not limited to disappearance of your cat. (I apologize for the language - just finished reading a 15 page long contract) -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

11 years, 10 months

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UmTRX v1b coming soon

by Andrey Sviyazov

Arrived to a place of relaxation and... started to work :( There are questions about EB-570: 1) Is it used somewhere? In the datasheet there is probable errors, for example, 1PPS is specified as input. 2) There are inputs Reset and Standby. The first can be left open, and the second is possible need to be connected to to FPGA. 3) There Is RTC_CLK_O we don't need him? And that there may be, 32768? 4) Which of two UART's better to use or are they equivalent? There are no any words in datasheet about it. 5) Unfortunately no place for both on PCB and we can use either EB-230 or EB-570. Best regards, Andrey Sviyazov.

11 years, 11 months

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Fwd: UmTRX UHD firmware

by Alexander Chemeris

Hi all, Attached is an UHD-based FPGA image for UmTRX. We've just fixed one last bug in the Tx chain and I think it's a good time to let everyone know about the progress. Corresponding host software could be built from the 'fairwaves/umtrx-dboard' branch in our repo: https://github.com/chemeris/UHD-Fairwaves/tree/fairwaves/umtrx-dboard Notes: 1. UHD code doesn't touch LMS configuration at all. So all LMS configuration should be done before you run UHD tools with the help of 'umtrx_lms.py' utility. This includes turning on LMS Rx/TX modules, tuning, calibration, amplifiers configuration, etc: https://github.com/chemeris/UHD-Fairwaves/blob/fairwaves/umtrx-dboard/host/… 2. So far only Tx has been tested and is known to work fine. Rx testing is our next target. 3. LMS works at 13 MSPS and UHD allows you to go up to this rate. Interpolation in Tx chain is known to work well, so you could also use fractions of that rate, like 0.270833 MSPS ;) 4. It's strongly recommended to tune VGA1 DC offset in a LMS before using - it reduces LO leakage by very nice 25 dB. 5. We still have to figure out how to tune I/Q balance in UHD. Without calibration LMS doesn't perform very well. I know it should be pretty straightforward to do, but we have to figure out how. -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

12 years

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Selectivity improvement solutions proposal for UmTRX

by Jean-Samuel Najnudel - BJT PARTNERS SARL

Hi Alexander, These last days, I tried to find a solution for the selectivity improvement. I have 5 solutions to propose. 1st and 2nd are inboard solutions. 3rd, 4th and 5th uses an external board. Some seems to be much better than others. 1/ We could use an IF frequency above 375 MHz to be able to connect the IF signal dirtectly to the LMS, without any upconvertion back to RF frequency. This would save some components. We could use the ADRF6601 (PLL/VCO + mixer) and the TB0448A IF SAW filter. The ADRF6601 is single chip PLL/VCO and mixer. This would be quite convenient. The TB0448A is cheap (< 3 USD), narrow band (good selectivity) and 400 MHz center frequency (> 375 MHz LMS lower limit). Cost of this solution would be about 60 USD and selectivity would be really good. The main disadvantage of this solution is the filter would restrict the signal to a single GSM carrier. This would avoid us to get both GSM carriers on each LMS. We would not be able to get true diversity. We would only be able to get switched diversity. After the LNA, RF SAW filter and the RF switches, we can split the signal between the current RX path to LMS RX LNA 3 and a new alternate RX path (ADRF6601 => TB0448A => LMS RX LNA 1). Depending of our need for selectivity, we would be able to select 1 of these 2 RX path (direct RX path to LMS RX LNA 3 or IF filter RX path to LMS RX LNA1). This would allow to use the board either as a normal wideband SDR board or with a very selective filter. 2/ A very nice option would be to use a variant of the 1st solution with a wider bandwidth SAW IF filter. For example, if we use a 400 to 600 KHz bandwidth IF filter, we would also get a very good selectivity and we would also be able to sample both GSM carriers on each LMS. This would allow a good selectivity and full diversity. The problem is we would need a 400 to 600 KHz SAW IF filter, with good selectivity, reasonable price and an IF center frequency above 375 MHz. I was not able to find such a filter. 3/ As suggested a few days ago, we may use the external selectivity improvement board design I sent you. Instead of the Triquint 856378 IF SAW filter, we could use the TAISAW TB0448A narrow band filter. This TAISAW filter is really much cheaper than the Triquint. This would save a lot of budget. However, we would still need 4 mixer and 2 PLL/VCO for each LMS RX path. This external board would cost approximately 100 USD (excluding PCB and assembly). We would need 2 of these boards for each UmTRX board. This would make 200 USD per UmTRX. Including PCB and assembly, toatl cost would be around 300 USD. This is not compeltely unrealistic but it seems still quite expensive. 4/ Another solution would be to build a single carrier version of the 3rd solution design. We would need only 1 RF path (PLL/VCO + mixer) with only 1 narrow band filter per LMS RX path. This would not need any splitter or combiner. Design would be quite simple and cost would be about 2 times lower. However, as we will have only 1 carrier on each antenna, we would not be able to get diversity at all. This solution would finally not have many advantages compared to 1st solution. It would cost more and would not allow any kind of diversity. 5/ Last solution would be to build an external diversity improvement board, as 4th solution, but with a wider band IF SAW filter. We could use the following RF path: LNA => RF SAW filter => mixer => IF SAW filter => mixer => RF SAW filter. Dual mixer could be the ADL5802 connected to the ADF4350 PLL/VCO. We could use the TB0218A IF SAW filter. This filter is quite affordable (< 10 USD). Selectivity is good and bandwidth is wide enough to select 2 GSM carriers (separated by 400 KHz). Cost of such external diversity improvement board would be quite reasonable. This would be a very nice solution to select 2 GSM carriers. Connected to the UmTRX, this selectivity improvement board would allow to get both switched or true diversity. As TB0218A center frequency is 140 MHz, we would not be able to connect directly the IF signal to the LMS. We would need to up convert the signal back to the RF frequency. As IF down converted signal is upconverted back to the original RF frequency, it would be possible to use this selectivity improvement board with any kind of existing OpenBTS (UmTRX, USRP, SSRP...) or OpenBSC (Sysmocom BTS, IP.access nanoBTS...) hardware to improve the Rx selectivity. This would offer a wider potential market than an inboard solution. Considering all these solution, I believe 1st and 5th solutions seems to be the best choices. 2nd solution would also be really nice but I was not able to find the appropriate IF SAW filter. Please let me know your opinion regarding each of these two solutions. By the way, the TB0448A and TB0218A SAW filters looks really good but I am not 100% sure the GSM carrier spectrum distortion due to the pass band ripple of the SAW filter is acceptable. Center part of the GSM carrier (f +/- 100 KHz) is fine but side parts of the GSM carrier (bellow f - 100 KHz and above f + 100 KHz) may be cut a bit by the SAW filter. Could you also please check the TB0448A and TB0218A datasheets to double check if the usable bandwidth is wide enough ? Especially, do you think cutting a bit the side parts of the GSM carrier may cause problem ? Anyway, please let me know your point of view regarding these selectivity improvement solutions. Best regards. Jean-Samuel. :-)

12 years

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UmTRX hardware development plan

by Alexander Chemeris

Andrey Sviyazov, I think this question is mostly for you. Could you please outline the development plan for the UmTRX hardware (with all associated things, like RF board design)? What are critical dependencies? E.g. when we should decide on the casing? My feeling is that we've lost the track and focus on things which are important, but not at this stage. -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

12 years, 1 month

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UmTRX marketing. Was: Selectivity improvement solutions proposal for UmTRX

by Alexander Chemeris

Andrey and all, 18.03.2012 2:31 пользователь "Andrey Sviyazov" <andreysviyaz(a)gmail.com> написал: >> Regarding the GSM spec, I believe these blocker tests are hard to pass and not that useful in most practical situations. However, I do not care that much about passing this spec for my network deployment in Mayotte but I really believe passing the spec will be very important for you if you wish to sell your hardware solution to some major operators. Moreover, as we would anyway need a superheterodyne selective filtering to get a reasonably narrow Rx sampling band (< 1.5 MHz LMS band), it does not cost that much more to try to pass the GSM spec. > > You right, it is important for us and may be it is really important for systems with high channel dencity. I completely support everything which could make our product better without increasing its cost. But we also must ensure to release UmTRX in time. What we all should keep on mind is that "the best is an enemy to a good". We should focus on those 10% of simple tweaks which bring us 90% of improvement. Otherwise we'll be swamped with the other 90% of tweaks and will miss the market opportunity. I can't stress it more - we MUST release UmTRX ASAP. Even if it doesn't meet macro-BTS requirements. We'll be able to fix this in the next version if ever needed - we can't know the real demand until we release the first version. I would be glad of what I've just said is obvious and already lives in your heart. Otherwise it's extremely important you understand this deeply, not formally. Please let me know if you don't, I'll explain in more details. > Furthermore, it is very easy to lose the reputation of the product, but it is very difficult then to fix it back. This is true. And the best way to keep the reputation is to realistically understand UmTRX capabilities and avoid overmarketing. In other words, with just reasonable product quality, our reputation depends solely on the right marketing. E.g. we might explicitly warn customers that it's not suitable for macro-BTS installations and they could do so on their own risk only. > I think, low cost doesn't sign low quality, so we must to have good hardware on market for good sales and promote OpenHW :) This is very true. Just keep in mind that "good hardware" means "minimally viable hardware at low price" and doesn't mean "super high quality mumbo jumbo with many zeros in the price". Our customers value simplicity and low cost over complexity and golden plates. That said, I can't help with decisions on the RF side and here I rely on you, guys. That's why it is so important for you to understand all these "abstract" marketing ideas. Sent from my Android device. -- Regards, Alexander Chemeris CEO, Fairwaves LLC http://fairwaves.ru

12 years, 1 month

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UmTRX integration into UHD

by Max.Suraev＠fairwaves.ru

Hello. Right now we're working on integrating UmTRX support into host UHD code. The dboard_iface is obviously different from usrp2 and got to be written from scratch (with compatible interfaces if possible). As for plugging UmTRX into uhd::usrp::multi_usrp - there're several options in here: 1) Add support for UmTRX-specific clock and codec controllers into usrp2_impl with boolean flag to differentiate between USRP2 and UmTRX. 2) Create dedicated "class umtrx_impl : public uhd::device" and implement codec and clock controllers logic in there or inside UmTRX's dboard_iface. 3) Create separate lib/umtrx/* implementation without reuse\adoption of code from lib/usrp2/* What would be better option and why? Bear in mind that the final goal is to run OpenBTS+UHD on UmTRX so we're interested only in functions essential to OpenBTS. Though we want to keep changes to the original code as small as possible and still reuse it as much as possible. -- best regards, Max, http://fairwaves.ru

12 years, 2 months

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UmTRX hackathon

by Alexander Chemeris

Hi all, I just realized I completely forgot to tell non-Russian people here that the Fairwaves is getting together to have a UmTRX hackathon in Moscow during this and the next weekends. The first hackathon is starting today and is due at Sun (Feb 3-5) and the next one will be the next Sat and Sun (Feb 11-12). The goal is to prepare for MWC: (1) bring up UmTRX to a minimal working state and get it working with OpenBTS, (2) prepare casing, demos, marketing material, etc. Participants from Fairwaves: Andrey Karpenkov, Andrew Sviyzov, Andrey Bakhmat, Alexander Chemeris, Ivan Kluchnikov, Max Suraev, Sergey Kostanbaev I invite everyone else to join us remotely as well. :) E.g. it would be awesome to have ICAP finally working to get Ethernet flashing to work. TCXO taming to GPS is another topic to take on. UHD integration is also an interesting topic with a lot of things to do. -- Regards, Alexander Chemeris.

12 years, 3 months

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Access to peripheral parts of UmTRX.

by Andrey Sviyazov

Today I used a cheap external active GPS antenna with a thin 5 m cable (see attached DS), but I had to solder SMA connector instead of unknown to me. The current consumption of the antenna 11мА @ 3V. About 2 minutes after a cold start, the status LED starts blinking 0.5 Hz and 1PPS signal appears at the Clock output connector. So, now we can to start work with the self-tuning of the TCXO. Anyway, how realistic in the near time to implement an simple command translator through the FTDI - FPGA for the SPI to each LMS to get at least the signals of their synthesizers (also to UART for GPS, to SPI for DAC of TCXO and etc. :). It can be a simple protocol with virtual control registers addressing and read/write or a few separate firmwares for each goal. With such a tool at any time we will be able to check UmTRX operation with some simple signals and an spectrum analyzer. Also it will be very helpful for the understanding of how to work with LMS control registers, which is poorly described in the documentation. Have any thoughts or suggestions on this? Best regards, Andrey Sviyazov.

12 years, 3 months

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UmTRX production

by Jean-Samuel Najnudel - BJT PARTNERS SARL

Hi Alexander, I will meet the French fab next monday. I am quite optimistic. This company looks really serious and prices seems to be reasonable. They would need some information about the TI160808U601 and the TI201209U121. Could you please let me know a supplier for these beads ? Do you have an approximate idea of the price of these components ? By the way, if it is not already included in the GPS chip, it might be useful to add a 1575 MHz GPS SAW filter on the GPS Rx path. As we will transmit a strong GSM Tx signal, it might saturate the GPS Rx if we place the GPS antenna near the GSM antenna. What do you think ? Please let me know. Best regards. Jean-Samuel. :-)

12 years, 3 months

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UmTRX issues and commits mailing lists

by Alexander Chemeris

Hi all, I have created mailing lists with notifications from UmTRX issue tracker and from UmTRX-UHD github repository. Feel free to subscribe to them if you want to track one or another closely: http://lists.fairwaves.ru/listinfo/umtrx-issues http://lists.fairwaves.ru/listinfo/umtrx-uhd-commits -- Regards, Alexander Chemeris.

12 years, 3 months

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UmTRX prototypes are out of fab!

by Alexander Chemeris

Hi all, A quick update. We've received our 5 UmTRX proto units from a fab! Pictures are attached (3D model is attached for comparison). Andrey Sviyazov is soldering missing components to them as I type. He will do the first power on later today. Lets have fingers crossed that it won't blow up and I will be able to take one with me to 28C3. We plan to give that one to Sylvain who is interested in helping us with bringing up. One more will be sent to Robin and three will stay here, as we're spread over three locations here. -- Regards, Alexander Chemeris.

12 years, 4 months

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UmTRX prototype 1 final version

by Alexander Chemeris

Hi all, Just an update. We've finished PCB layout (ugh, finally!) and are sending them to a fab today or tomorrow. Attached are latest files and 3D images of the board. I hope we'll be holding a working prototype in our hands soon! Thank you all for your help! -- Regards, Alexander Chemeris.

12 years, 6 months

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UmTRX aka OpenBTS HW update

by Alexander Chemeris

Hi Jean-Samuel, Harald, Holger, I've been quite for a while, so I want to make an update about the state of our hardware. On the FPGA development side we've been stuck for ~3 weeks, because somethings happened with the power controller on our Xilinx SP-605 board and we've been waiting for TI's USB-TO-GPIO to flash this controller. And now we're still dealing with this problem. On the hardware side things are much better. We have "Release Candidate" of schematics and working on PCB layout. We estimate that layout will be finished in a week if we don't decide to change something too much. In attachment you could find the latest versions of schematics in PDF and Altium Designer formats, 3D view (pre-alpha version), list of FPGA I/O and BOM. I would very much appreciate any comments, questions, concerns and ideas about schematics, controls placement, debug facilities, etc. It's much, much better to find bugs and satisfy all requests now, then when we get PCBs printed. Following the idea of Jean-Samuel we're trying to fit the PCB into 5.25" form-factor to be able to use various standard enclosures and even mount the board into a standard PC cases instead of a CD-ROM drive :) Right now estimated board size is 135х170mm, which perfectly fits into 5.25" case. Meantime I've created Google Code project to host our development: http://code.google.com/p/umtrx/ It's empty yet, I plan to gradually fill it with information. I'm happy to grant member rights for the project to any of you who is willing to contribute to descriptions, code (not there yet), etc. Just drop me an e-mail when you feel you need those rights. -- Regards, Alexander Chemeris.

12 years, 6 months

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