RM520 – Cannot Register to Private 5G SA (OAI NR) – Assistance Required

Technical Subjects
1

Hello,

I am using a Quectel RM520 module to connect to a private 5G Standalone (SA) network deployed with OAI (OpenAirInterface) on band n77 at 3.9 GHz using USRP B210.
The SIM is a Syscom 5G test SIM and it works successfully inside my Samsung Galaxy A15 on the same private network (PLMN = 00101).
However, when using the RM520, the module detects the SIM (AT+CPIN = READY), but registration fails and AT+COPS or AT+QNWINFO return “No Service”.

2

Please use a commercial SIM card and network for the cross-validation test.

3

Hello,

I tested the RM520 with a commercial NRG Mobile SIM.
The module successfully:

  • registered to the LTE network
  • attached to the operator
  • activated PDP context
  • obtained an IP address

This confirms that the RM520 hardware and firmware are working correctly.

The remaining issue is specific to a private 5G SA network based on OpenAirInterface (OAI):

  • PLMN: 00101
  • Band: n77 (3.9 GHz)
  • gNB: USRP B210
  • Core: OAI 5G SA

The same Syscom SIM works correctly on a 5G smartphone (Samsung Galaxy A15) on this network, but not on the RM520.

Could you please advise:

  1. Whether RM520 officially supports OAI-based 5G SA private networks
  2. If any specific AT commands, NR5G settings, or firmware configuration are required
  3. If there are known limitations regarding non-commercial PLMN or private 5G cores

Thank you very much for your technical guidance.
Best regards

4

nrj modbile
nrj modbile763×423 26.4 KB