[srslte-users] Pi 4 srsLTE

[Andre Puschmann]

Kenneth,

frankly speaking we don't do much over-the-air testing ourselves with
the Pi4. All success or failure stories so far have been from users on
the list.

Anyway, we'll have a look into this over the next days.

Thanks
Andre

On 6/5/20 15:49, Kenneth Barlee wrote:
> Hey guys
> 
> I have been having a play with a Pi 4B /4GB rev 1.2 running the new
> Ubuntu Pi Server 20.04 x64 image, and trying to get srsLTE working. I
> know several others have been talking about trying this, but haven't
> noticed my issue coming up elsewhere.
> 
> I started with the latest versions of UHD, SoapySDR, LimeSuite, srsLTE
> (commit ID e3e38482100f5bf13f15af3bc09df882e937bc60). Everything
> compiles happily (no need to change those lines in CMakeLists.txt), and
> the srsenb/srsepc software runs successfully (after an initial wait of
> ~5 mins after first launch for any change in n_prb). However, no phone
> is able to fully connect when using a USRP B210/ LimeSDR-USB/
> LimeSDR-Mini. It seems to start the attach, and there is a core
> handshake, but the core reports that the "UE is not ECM connected" and
> the UE never shows the signal bars.
> 
> Decided to roll the Pi back to srsLTE v19.12, commit ID
> d045213fb9cbf98c83c06d7c17197a9dcbfddacf, as I have been running this on
> my desktop for a while now, and know it is stable. Again, this compiles
> without issue. With this version, a phone will join a USRP B210 (not the
> LimeSDRs, but that is probably another issue). It seems relatively
> stable, and can continue running for several hours with a phone attached
> running internet ping tests.
> 
> I have attached logs and PCAPs for the two setups.
> 
> A potentially related sidenote, with both srsenb versions, and all
> radios, "SCHED: Could not transmit RAR within the window (RA TTI=2591,
> Window=10, Now=2608)" type messages appear repeatedly in the terminal.
> Running cellmapper on the phone, the LTE timing advance is estimated to
> be '~250m' when using the USRP, but over '3.5km' with the LimeSDRs. This
> is likely one of the reasons the LimeSDRs do not work with srsLTE v19.12.
> 
> For reference, the UE used was a Samsung S20 Ultra 5G; LTE B3 earfcn
> 1934, n_prb=15, SISO tm=1 nof_ports = 1.
> 
> Has anybody experienced similar? Happy to do more testing if it helps
> with debugging!
> 
> Thanks
> 
> 
> Kenny Barlee | Research Associate
> Software Defined Radio Research Laboratory
> Department of Electronic and Electrical Engineering
> University of Strathclyde
> 
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