[srslte-users] Help with srsUE

Thu Feb 2 14:23:36 UTC 2017

Hi Patrick

Thx for your very useful information. I am still working on with the tuning
of tx and rx gain.
The measuring of eNB the signal strength was quite easy as the eNB is
sending more or less continuously.

The situation is not the same on the ue side, as the transmissions are very
short and few.
Is there a way to make the ue side transmit continuously for tuning
purposes.

Just wonder what are your current tx and rx gain settings on amarisoft and
srsue, when using the 40 dB attenuator in between?

Regards

Em

On Wed, Feb 1, 2017 at 5:23 PM, Patrick Cutno <PCutno at girdsystems.com>
wrote:

> Emilie,
>
>
>
> Just an update, I have mentioned before that my Amarisoft eNB is running
> on a Nutaq PicoSDR 4x4 and I have been trying to get it to work a B210. . .
> I just got that to work.
>
>
>
>    1. An old version of UHD had to be used (sorry but a coworker set that
>    up for me so I don’t have instructions for this)
>    2. Amarisofts ‘launch_enb.sh’ had to be modified to specifically call
>    the older version of UHD not the newer one I already had installed
>
>
>
> srsUE has always worked perfectly with Amarisoft on the Nutaq box. When I
> put the Amarisoft stack on a different computer that used a B210, I was
> getting a lot of link failures but I knew it wasn’t srsUE’s fault. Using
> the setup previously described to reduce the number of variables, I was
> able to tune the eNB’s tx gain to output somewhere between -10 to 0 dBm
> (before attenuation) and adjust the rx gain up and down until I got a solid
> connection. Amarisoft’s default rx gain defined by the single channel rf
> driver for the B210, turns out to be too high. I came to the conclusion
> that the high rx gain actually hurt the signal and Amarisoft’s terminal
> agreed by reporting really bad uplink SNR. By significantly reducing the
> eNB rx gain, I was able to improve the uplink SNR with srsUE and get a
> solid connection with no link failures.
>
>
>
> I am still getting underflows and late messages on the eNB B210 but I will
> continue to look into it and maybe use a N210 instead.
>
>
>
> Pat
>
>
>
> *From:* Patrick Cutno
> *Sent:* Wednesday, February 01, 2017 10:06 AM
> *To:* 'Emilie Meyer' <emiliemeyer1016 at gmail.com>
> *Cc:* 'srslte-users at lists.softwareradiosystems.com' <srslte-users at lists.
> softwareradiosystems.com>
>
> *Subject:* RE: Help with srsUE
>
>
>
> Emilie,
>
>
>
> I am using SISO.
>
> And you’re welcome, hopefully you can figure out your issue if it is a RF
> problem.
>
>
>
> Pat
>
>
>
> *From:* Emilie Meyer [mailto:emiliemeyer1016 at gmail.com
> <emiliemeyer1016 at gmail.com>]
> *Sent:* Wednesday, February 01, 2017 9:02 AM
> *To:* Patrick Cutno <PCutno at girdsystems.com>
> *Subject:* Re: Help with srsUE
>
>
>
> Hi Patrick
>
>
>
> I highly appreciate that you share your experience and knowledge.
>
> I will do the suggested modification today.
>
>
>
> BTW, do you use SISO or MIMO on your Amarisoft?
>
>
>
> > I don’t have an explanation of why a COTS device works fine wirelessly,
> but the setup above helped me pinpoint my RF problem with minimal variables
> to consider.
>
>
>
> Maybe some experts could help clarify this issue, why a COTS UE can
> communicate with eNB at 10-15 meters distance without problem, while an SDR
> based UE cannot, even when the distance is only 1-2 meters.
>
> It makes no sense to me that a COTS UE with limited resources can do it
> better than an SDR based UE with much more resources. A guess is that this
> issue is related to the configuration of tx/rx parameters on srsUE side?
>
>
>
> > I don’t know if you are aware, but once you get Amarisoft’s eNB running,
> you can enter ‘t’ in the same terminal, and it will report link information
> like CQI, SNR, etc. The same for srsUE, once you have a connection between
> the UE and eNB, enter ‘t’ on the srsUE terminal and it will also print link
> information.
>
>
>
> Thanks for this tips. I was  not aware of this.
>
>
>
> Regards
>
>
>
> Em
>
>
>
>
>
>
>
>
>
>
>
> On Tue, Jan 31, 2017 at 5:14 PM, Patrick Cutno <PCutno at girdsystems.com>
> wrote:
>
> I forgot to mention, I picked 0 dBm arbitrarily. You could instead tune
> the two points to -10 dBm since when you start transmitting and receiving
> data, the power will be higher than at idle. Too much power could hurt the
> signal and lead to bad performance.
>
>
>
> *From:* Patrick Cutno
> *Sent:* Tuesday, January 31, 2017 8:34 AM
> *To:* 'Emilie Meyer' <emiliemeyer1016 at gmail.com>
> *Cc:* srslte-users at lists.softwareradiosystems.com
> *Subject:* RE: Help with srsUE
>
>
>
> Emilie,
>
>
>
> Just to reduce the number of variables, try removing the duplexer and
> antennas from your setup. Sorry if I wasn’t clear, but you have everything
> right up to point B and C of your schematic. Now just connect B and C
> directly to the Amarisoft frontend.
>
>
>
>    1. Tune the power_output on Amarisoft such that the measured signal
>    strength at point C in the schematic (or maybe A?) is 0 dBm.
>
>
>    1. Correct, at point C (When point C is directly connected to the
>       Amarisoft frontend).
>
>
>    1. Tune the TX gain in srsUE to achieve 0 dBm at point D in the
>    schematic.
>
>
>    1. Also correct
>
>
>    1. And both attenuators are set to 40 dB
>
>
>    1. Yep yep.
>
>
>
> As I mentioned before, I have run into the same issue you are having
> before. A COTS device works perfectly fine wirelessly, but I would get a
> link-failure with srsUE. When I directly connected srsUE to the Amarisoft
> frontend (with attenuators), I was able to get a complete connection and
> could run iperf tests. However I was still occasionally getting link
> failures. Turns out the Amarisoft’s rx gain wasn’t configured properly on
> my setup and Amarisoft was reporting very bad SNR’s for the uplink channel
> that caused the link to fail. I don’t have an explanation of why a COTS
> device works fine wirelessly, but the setup above helped me pinpoint my RF
> problem with minimal variables to consider.
>
>
>
> I don’t know if you are aware, but once you get Amarisoft’s eNB running,
> you can enter ‘t’ in the same terminal, and it will report link information
> like CQI, SNR, etc. The same for srsUE, once you have a connection between
> the UE and eNB, enter ‘t’ on the srsUE terminal and it will also print link
> information.
>
>
>
> Pat
>
>
>
> *From:* Emilie Meyer [mailto:emiliemeyer1016 at gmail.com
> <emiliemeyer1016 at gmail.com>]
> *Sent:* Tuesday, January 31, 2017 5:01 AM
> *To:* Patrick Cutno <PCutno at girdsystems.com>
> *Cc:* srslte-users at lists.softwareradiosystems.com
> *Subject:* Re: Help with srsUE
>
>
>
> Seems like the schematic was not embedded properly in the previous mail.
>
> The picture is attached here.
>
>
>
>
>
> On Tue, Jan 31, 2017 at 10:57 AM, Emilie Meyer <emiliemeyer1016 at gmail.com>
> wrote:
>
> Hi Patrick
>
>
>
> Thanks a lot for your advice. Just to make sure that I've understood it
> correctly, the attached schematic shows my lab setup.
>
>
>
> [image:
> https://mail.google.com/mail/?ui=2&ik=4af75ccfc6&view=fimg&th=159f3e3d3312a562&attid=0.1&disp=emb&realattid=ii_iylbst1e0_159f3de8197a3acf&attbid=ANGjdJ9sbscX2Kua7jO9Ap2Si2_FDVf8QL00uCf5oyqgbv4fq0pfF_5VCO631_OGC7-DLpywbocvucBsodNbGI1Jy2Ptm79oWs1rtruXHtqQTek5R57h_WksUcaHRek&sz=s0-l75&ats=1485855511453&rm=159f3e3d3312a562&zw]
> 
>
> What I should do:
>
>
>
> 1. Tune the power_output on Amarisoft such that the measured signal
> strength at point C in the schematic (or maybe A?) is 0 dBm.
>
> 2. Tune the TX gain in srsUE to achieve 0 dBm at point D in the schematic.
>
> 3. And both attenuators are set to 40 dB
>
>
>
> Can you confirm that this is correct or not.
>
>
>
> In my setup I have used a OAI duplexer for band 7 provided by Telmat. Did
> you use a similar duplexer in your setup?
>
>
>
> Furthermore the RF frontend for Amarisoft is PCI express SDR Mimo, that
> came with the Amarisoft OTS100.
>
>
>
>
>
>
>
> Best regards
>
>
>
> Em
>
>
>
> On Mon, Jan 30, 2017 at 2:54 PM, Patrick Cutno <PCutno at girdsystems.com>
> wrote:
>
> Emilie,
>
> On the srsUE side, in your config file, comment out the 'rx_gain'
> parameter to enable the AGC. For the 'tx_gain' parameter, I have my gain
> set to 82 for a transmit channel power of approximately 0 dBm.
>
> If this is a hardware setup issue, here are the things I would try:
> 1: Connect using 40 dB attenuators on the rx and tx lines
> 2: Comment out 'rx_gain' in the srsUE config file to use AGC
> 3: incrementally increase the 'tx_gain' to get close to 0 dBm before the
> 40 dB attenuation (I don’t know about your current lab setup, but a signal
> analyzer of some sort would be needed to measure the dBm's).
>
> On the Amarisoft side:
> 1: Incrementally increase the 'power_output' parameter to get the TX to
> approximately to 0 dBm before the 40 dB attenuation
>
> Hope this helps. Also, what radio are you using for Amarisoft?
>
> Pat
>
>
> -----Original Message-----
> From: srslte-users [mailto:srslte-users-bounces@
> lists.softwareradiosystems.com] On Behalf Of srslte-users-request at lists.
> softwareradiosystems.com
> Sent: Saturday, January 28, 2017 8:12 AM
> To: srslte-users at lists.softwareradiosystems.com
> Subject: srslte-users Digest, Vol 23, Issue 44
>
> Send srslte-users mailing list submissions to
>         srslte-users at lists.softwareradiosystems.com
>
> To subscribe or unsubscribe via the World Wide Web, visit
>         http://www.softwareradiosystems.com/mailman/listinfo/srslte-users
> or, via email, send a message with subject or body 'help' to
>         srslte-users-request at lists.softwareradiosystems.com
>
> You can reach the person managing the list at
>         srslte-users-owner at lists.softwareradiosystems.com
>
> When replying, please edit your Subject line so it is more specific than
> "Re: Contents of srslte-users digest..."
>
>
> Today's Topics:
>
>    1. Help with srsUE (Emilie Meyer)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Sat, 28 Jan 2017 14:20:53 +0100
> From: Emilie Meyer < >
> To: srslte-users at lists.softwareradiosystems.com
> Subject: [srslte-users] Help with srsUE
> Message-ID:
>         <CAFF9uhqdvEo8pwg+-4B5y9Vcc5RiRDC3odtjCJr=Lh3Oc7u
> wEg at mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
>
> Hi all
>
> I have struggled with srsUE for weeks trying to connect it with both OAI
> and now Amarisoft.
> In both cases, I experienced failure during Random Access procedure, I
> think.
>
> I have tested with both master and next branch of srsLTE/srsUE.
>
> What I have seen in all tests is the recurring message:
>
> "Warning: Detected Radio-Link Failure
> RRC Connection released."
>
> How can I solve this? How can I troubleshoot what is wrong and make it
> work?
> I really appreciate for all advices.
>
>
> The output from the latest test is shown below. Also attached are the log
> files.
>
>
> ---  Software Radio Systems LTE UE  ---
>
> Reading configuration file amarisoft.ue.conf...
> Using srsLTE version 001.004.000
> Opening USRP with args: type=b200
> -- Detected Device: B210
> -- Operating over USB 3.
> -- Initialize CODEC control...
> -- Initialize Radio control...
> -- Performing register loopback test... pass
> -- Performing register loopback test... pass
> -- Performing CODEC loopback test... pass
> -- Performing CODEC loopback test... pass
> -- Setting master clock rate selection to 'automatic'.
> -- Asking for clock rate 16.000000 MHz...
> -- Actually got clock rate 16.000000 MHz.
> -- Performing timer loopback test... pass
> -- Performing timer loopback test... pass
> -- Asking for clock rate 32.000000 MHz...
> -- Actually got clock rate 32.000000 MHz.
> -- Performing timer loopback test... pass
> -- Performing timer loopback test... pass Setting frequency: DL=2680.0
> Mhz, UL=2560.0 MHz Searching for cell...
> Searching for cell...
> Searching for cell...
> Searching for cell...
> Found CELL ID: 1 CP: Normal  , CFO: 3.8 KHz.
> Trying to decode MIB...
>  - Cell ID:         1
>  - Nof ports:       2
>  - CP:              Normal
>  - PRB:             25
>  - PHICH Length:    Normal
>  - PHICH Resources: 1
>  - SFN:             0
> MIB received BW=5 MHz
> Initializating cell configuration...
> Setting Sampling frequency 5.76 MHz
> Setting TX/RX offset 93 samples, 16.15 us
> SIB1 received, CellID=257,  PLMN Id: MCC 001 MNC 01 Sync error.
> SIB2 received
> Sync error.
> Random Access Transmission: seq=1, ra-rnti=0x5 Random Access Transmission:
> seq=2, ra-rnti=0x5 Random Access Transmission: seq=3, ra-rnti=0x5 Random
> Access Transmission: seq=4, ra-rnti=0x5 Random Access Transmission: seq=5,
> ra-rnti=0x5 Random Access Transmission: seq=6, ra-rnti=0x5 Random Access
> Transmission: seq=7, ra-rnti=0x5 Random Access Transmission: seq=8,
> ra-rnti=0x5 Random Access Transmission: seq=9, ra-rnti=0x5 Random Access
> Transmission: seq=10, ra-rnti=0x5
> Warning: Detected Radio-Link Failure
> RRC Connection released.
> Sync error.
> Sync error.
> Sync error.
> Sync error.
> Sync error.
> Warning: Detected Radio-Link Failure
> RRC Connection released.
> Sync error.
> Sync error.
> Sync error.
> Sync error.
> Sync error.
> Timeout while synchronizing SFN
> PCCH message received 18 bytes
> Sync error.
> Warning: Detected Radio-Link Failure
> RRC Connection released.
> PCCH message received 32 bytes
> Sync error.
> Sync error.
> Sync error.
> PCCH message received 18 bytes
> Sync error.
> Sync error.
> Sync error.
> Sync error.
> Sync error.
> Sync error.
> PCCH message received 32 bytes
> Sync error.
> Timeout while synchronizing SFN
> ^CPCCH message received 32 bytes
> Sync error.
> Saving PCAP file
>
>
> ---  exiting  ---
>
>
> --
> Regards
>
> Emilie
>
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL: <http://www.softwareradiosystems.com/pipermail/srslte-users/
> attachments/20170128/74756986/attachment.html>
> -------------- next part --------------
> A non-text attachment was scrubbed...
> Name: ue.log
> Type: text/x-log
> Size: 27472 bytes
> Desc: not available
> URL: <http://www.softwareradiosystems.com/pipermail/srslte-users/
> attachments/20170128/74756986/attachment.bin>
> -------------- next part --------------
> A non-text attachment was scrubbed...
> Name: ue.pcap
> Type: application/vnd.tcpdump.pcap
> Size: 457 bytes
> Desc: not available
> URL: <http://www.softwareradiosystems.com/pipermail/srslte-users/
> attachments/20170128/74756986/attachment.pcap>
>
> ------------------------------
>
> Subject: Digest Footer
>
> _______________________________________________
> srslte-users mailing list
> srslte-users at lists.softwareradiosystems.com
> http://www.softwareradiosystems.com/mailman/listinfo/srslte-users
>
>
> ------------------------------
>
> End of srslte-users Digest, Vol 23, Issue 44
> ********************************************
>
>
>
>
>
> --
>
> Regards
>
>
>
> Emilie
>
>
>
>
>
> --
>
> Regards
>
>
>
> Emilie
>
>
>
>
>
> --
>
> Regards
>
>
>
> Emilie
>

-- 
Regards

Emilie
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.srsran.com/pipermail/srsran-users/attachments/20170202/2bcf35bd/attachment.htm>