Unstable connections between srsUE and gNB

[Minglong2012]

Hi,

We are using usrp B210s to set up srsRAN gNB with srsUE, as described here: https://docs.srsran.com/projects/project/en/latest/tutorials/source/srsUE/source/index.html

However, the link between them is very unstable. The UE drops quickly a few miniutes after it connects to gNB. I checked the log file of UE, it shows that 'NR SFN (570) does not match current SFN (566)'.

I have attached the log file. Can someone give a help?

Thank you.
ue.log

[herlesupreeth]

Hmm, looks like UE went out of sync as you mentioned. Can you also post the gNB logs in debug level?

2023-11-06T21:15:04.855062 [PHY-SA ] [E] [ 3290] SYNC: detected out-of-sync... skipping slot ...
2023-11-06T21:15:04.856204 [PHY-SA ] [E] [ 3290] SYNC: detected out-of-sync... skipping slot ...
2023-11-06T21:15:04.857066 [PHY-SA ] [E] [ 3290] SYNC: detected out-of-sync... skipping slot ...
2023-11-06T21:15:04.858133 [PHY-SA ] [E] [ 3290] SYNC: detected out-of-sync... skipping slot ...
2023-11-06T21:15:04.859049 [PHY-SA ] [E] [ 3290] SYNC: detected out-of-sync... skipping slot ...
2023-11-06T21:15:04.860079 [PHY-SA ] [E] [ 3290] SYNC: detected out-of-sync... skipping slot ...
2023-11-06T21:15:04.861137 [PHY-SA ] [E] [ 3290] SYNC: detected out-of-sync... skipping slot ...
2023-11-06T21:15:04.862024 [PHY-SA ] [E] [ 3290] SYNC: detected out-of-sync... skipping slot ...
2023-11-06T21:15:04.863085 [PHY-SA ] [E] [ 3290] SYNC: detected out-of-sync... skipping slot ...
2023-11-06T21:15:04.864147 [PHY-SA ] [E] [ 3290] SYNC: detected out-of-sync... skipping slot ...
2023-11-06T21:15:04.865110 [PHY0-NR] [E] [ 3290] PBCH-MIB: NR SFN (330) does not match current SFN (329)

[Minglong2012]

Okay, what caused this?

[Zplusless]

Have you tried to link both usrp-b210s with SMA cable? My setup could not even finish attachment over the air but works well using SMA cable.

[Minglong2012]

Yes, actually I was actually using SMA cable to connect them. I mistakenly described it over the air. Can you show your hardware and software configuration? And do you use power adapter to supply power to usrp B210? How does long does the link last (while use iperf3 for traffics) if you use cable?

[Zplusless]

My case: #298 (comment)

[Zplusless]

BTW, a new version of srsUE is released, you can try it.

https://github.com/srsran/srsRAN_4G/releases/tag/release_23_11

[pgawlowicz]

Please try to run the following script on both PCs (gnb and srsUE):
https://github.com/srsran/srsRAN_Project/blob/main/scripts/srsran_performance

[Minglong2012]

Thanks, it works well now