srsRAN gnodeb GEO NTN connection issue with emulated UE on TM500

[ramvasu]

Tested with two versions of srsRAN gnodeb (srsRAN 5G gNB version 24.10.0 (2be82d8) and srsRAN 5G gNB version 25.10.0 (8e4f0be) ) with GEO NTN config settings as recommended in srsRAN documentation ;

Have the following observations for both versions.The gnodeb and UE seem out-of-step in the RACH procedure

1. In gnodeb logs: " Discarding UL HARQ. Cause: HARQ-ACK wait timeout " -> gnb discards the TC-RNTI
2. Subsequently : "PUSCH: rnti=0x4601 h_id=0 prb=[2, 5) symb=[0, 14) mod=QPSK rv=0 tbs=11 crc=KO iter=6.0 sinr=-15.8dB t=263.1us uci_t=0.0us ret_t=0.0us
   2025-10-28T08:49:17.809192 [SCHED ] [W] [ 415.0**] Invalid UL CRC, cell=0, rnti=0x4601, h_id=0. Cause: Nonexistent tc-rnti**
3. Next Preamble received by gNodeb and new TC-RNTI assigned as in "Processed slot events pci=1:

• PRACH: slot=417.9 pci=1 preamble=6 ra-rnti=0x7f temp_crnti=0x4602 ta_cmd=3"

The above three steps keep repeating.

In UE (emulated) logs:
RRC: RRC Connection Establishment timed out (T300/T319 expired)

Any insights are welcome.
Can anyone share a working set of gnb and geo_ntn configurations? What all settings need to be tuned?
thanks

[ramvasu]

In addition, version 25.10.0 does not seem to accept cu_cp.rrc.rrc_procedure_timeout_ms parameter

[pgawlowicz]

hi @ramvasu,
Please use the newest version only. Could you share your final config file and gnb log file?
Best Regards,
Piotr

[ramvasu]

hi @pgawlowicz

Thanks for your reply. I have tested with version 25.10.0 (8e4f0be) and attached the gnb log file.

gnbrvm1fs.log

rgds