[srsran-users] (no subject)

[Jon Backman]

*Issue Description*
Hello! We are trying to use GNU Radio and srsRAN to create a flow chart
where a UE receives and sends its signals through ZMQ source and sink
blocks.

*Setup Details*
Two Linux Computers that run on Ubuntu 22.04
GNU Radio v 3.9
Two B200mini USRPs
We are doing over the air transmission

*Expected Behavior*
We want the UE and the eNodeB connect normally with the broker acting in
between so we can easily see and modify the IQ values coming into the
system.
Actual Behaviour

We have been able to successfully have a UE and eNodeB connect across these
two computers and USRPs without GNU radio. When we try to run it with our
flow graph, it cannot connect successfully. The UE can find cells, but
after it tries to synchronize with random access transmission it never
connects.
Steps to reproduce the problem

We have been doing everything on the command file using these commands:
sudo ./srsRAN/build/srsepc/src/srsepc
sudo srsenb
sudo .srsRAN/build/srsue/src/srsue --rf.device_name=zmq
--rf.device_args="tx_port=tcp://*:2001,rx_port=tcp://localhost:2000,id=ue,base_srate=11.52e6"

*Additional Information*
Here is an example of the output on the terminal
Found Cell: Mode=FDD, PCI=1, PRB=50, Ports=1, CP=Normal, CFO=-0.8 KHz
Current sample rate is 11.52 MHz with a base rate of 11.52 MHz (x1
decimation) Samp Rate : 11.520000 Current sample rate is 11.52 MHz with a
base rate of 11.52 MHz (x1 decimation) Found PLMN: Id=00101, TAC=7 Random
Access Transmission: seq=11, tti=3701, ra-rnti=0x2 Random Access
Transmission: seq=13, tti=3721, ra-rnti=0x2 Random Access Transmission:
seq=27, tti=3741, ra-rnti=0x2 Random Access Transmission: seq=26, tti=3761,
ra-rnti=0x2 Random Access Transmission: seq=49, tti=3781, ra-rnti=0x2
Random Access Transmission: seq=4, tti=3801, ra-rnti=0x2 Random Access
Transmission: seq=33, tti=3821, ra-rnti=0x2 Random Access Transmission:
seq=17, tti=3841, ra-rnti=0x2 Random Access Transmission: seq=35, tti=3861,
ra-rnti=0x2 Random Access Transmission: seq=31, tti=3881, ra-rnti=0x2 [zmq]
Error: tx time is 0.136 ms in the past (51497403 < 51498964) [zmq] Error:
tx time is 0.078 ms in the past (103677117 < 103678011) [zmq] Error: tx
time is 0.227 ms in the past (125524338 < 125526956)

Here is what is found in our log files for the UE
2022-08-01T21:23:52.722879 [PHY ] [W] [ 5695] SFN not yet synchronized,
sending out-of-sync 2022-08-01T21:23:52.722962 [PHY ] [W] [ 5695] SNR=1.4
dB RSRP=-46.7 dBm, sync=out-of-sync from channel estimator
2022-08-01T21:23:52.724029 [PHY ] [W] [ 5696] SFN not yet synchronized,
sending out-of-sync 2022-08-01T21:23:52.724169 [PHY ] [W] [ 5696] SNR=1.5
dB RSRP=-46.7 dBm, sync=out-of-sync from channel estimator
2022-08-01T21:23:52.725131 [PHY ] [W] [ 5697] SFN not yet synchronized,
sending out-of-sync 2022-08-01T21:23:52.725229 [PHY ] [W] [ 5697] SNR=1.8
dB RSRP=-47.1 dBm, sync=out-of-sync from channel estimator
2022-08-01T21:23:52.726227 [PHY ] [W] [ 5698] SFN not yet synchronized,
sending out-of-sync 2022-08-01T21:23:52.726307 [PHY ] [W] [ 5698] SNR=1.7
dB RSRP=-47.9 dBm, sync=out-of-sync from channel estimator
2022-08-01T21:23:52.727317 [PHY ] [W] [ 5699] SFN not yet synchronized,
sending out-of-sync 2022-08-01T21:23:52.727408 [PHY ] [W] [ 5699] SNR=1.5
dB RSRP=-48.6 dBm, sync=out-of-sync from channel estimator

I attached a picture of our flowgraph in the email.

Any and all help would be greatly appreciated.
Thank you!
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.srsran.com/pipermail/srsran-users/attachments/20220802/cd096e5f/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: LTE_GNU_flowgraph.png
Type: image/png
Size: 66532 bytes
Desc: not available
URL: <https://lists.srsran.com/pipermail/srsran-users/attachments/20220802/cd096e5f/attachment-0001.png>