COTS UEs do not connect to srsRAN SA gNB

[hdtuanss]

Hi everyone,

I am trying to connect COST UEs to srsgNB. I have followed the steps in the documentation and successfully connected several UEs to the gNB such as Pixel 8 Pro, Xiaomi K40 Gaming. For these, I set the correct PLMN, band, ARFCN, and forced SA mode as instructed.

However, plenty of other UEs (Galaxy S24 Ultra, S24, Z Flip 6, Z Flip 4, S22 Plus, S21, Note 20 Ultra, S20, S10 5G, Note 10 5G, OnePlus 9 Pro, Huawei Mate 20 X 5G) failed to connect, even when using the "5G Switch - Force 5G Only" app. I checked List of Known Working Third Party UEs and saw that some users have successfully connected several of the same Samsung phones that did not work for me (e.g., Z Flip 4, S24).

I am seeking your help to understand why these UEs are not connecting. My first guess is that the region-specific models might be the reason here. For example, Samsung Z Flip 4 SM-F721B is different from SM-F721N.
My questions are:

• Are there known reasons why these UEs fail to connect?
• Could this be due to SA mode being disabled by the manufacturer/operator (via Android settings, baseband firmware, or USIM configuration)? If so, is there any official documentation or posts related to this issue?

If you have any experience or tips to make these UEs work, please share with me.

Thank you for your help!