[srslte-users] zmq driver help

[Xavier Arteaga]

Hi Mirko,
It is great to read your interest in ZMQ.

The UE and the eNodeb have a number of timers specified by the 3GPP. Some
of these timers are based on system timers and not in RF-based timers. When
ZMQ between two computers is used, the baseband throughput is so low that
the latency sky-rockets and timers expire easily. This cause the UE to
frequently fail to attach.

You can set these timers to their maximum values in sib.conf:
  ue_timers_and_constants =
  {
      t300 = 2000; // in ms
      t301 = 2000;  // in ms
      t310 = 2000; // in ms
      n310 = 20;
      t311 = 30000; // in ms
      n311 = 10;
  };

I highly recommend using the srsue and srsenb in the same machine (no
virtual) as an initial step.

Also, we prepared the attached guide. It will be published in a few days
but it would be great getting some feedback on it.

Many thanks,
Xavier

On Tue, 16 Jul 2019 at 09:52, Mirko Kovacevic <northmirko at gmail.com> wrote:

> Hi there, Dear srsLTE
>
>
> I'm being delighted with latest release, especially with new feature Fake
> RF with zmq.
> Guys,
> you done fantastic job,
> planing to contribute my time to project.
>
> After several days of code review and mailing list traversing, I tried
> srsUE/srsENB with zmq driver installed on two separate VMs, each with 2x
> CPU, and 2048 MB of RAM, host machine 16GB / 8 CPU.
> I made regression tests on "make test zmq_driver" but test is not passing
> all the time.
> Maybe VMs are still not a desirable environment to execute  such kind of
> realtime tasks or something still need to be done to VM to perform better.
>
> Nevertheless,
> UE managed to decode BCCH, read the cell, sent message on PRACH.
> After that I only get Radio Link failures caused by tx time offset in
> transmission.
>
> I tried to play with options:
> ---------------
> --rf.time_adv_nsamples=value
> -------------------
> Put base_rate to
>
> base rate=1.92e6
> ------------
>
> Changed
> n_prb =6 (1.4Mhz bandwidth)
> ---------------
>
> but no progress at all.
>
>
> Do you have idea what else could be done when dealing with zmq driver ?
> How to determine tx time offset when using zmq ?
>
>
>
>
>
>
> --
>
> *Puno pozdrava,Mirko Kovacevic*
>
>
> _______________________________________________
> srslte-users mailing list
> srslte-users at lists.softwareradiosystems.com
> http://www.softwareradiosystems.com/mailman/listinfo/srslte-users
>
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