RG520F-EU - incorrect SINR readings with latest firmware

Hello there,

seems like the SINR reading for my RG520F-EU modem is wrong - it often reports values like -32768, but my average SINR of my otherwise pretty stable 5G NSA connection has always been between 12 to 14 dB. I could see other user here reporting this issue for another Quectel 5G modem, where SINR reading was okay with previous firmware… My current firmware version is RG520FEUEAR03A03M4G (I am using a Chateau 5G R16).

Can you please look at it and issue a fix in the next firmware version? Or has a newer firmware already been released for RG520F-EU?

Many thanks in advance,
Mikey

Which command did you use for query?

It’s invalid in either AT+QENG=“servingcell” or AT+QSINR.

What I have also observed, that the longer the connection is up (and the connection is pretty stable all the time as I have mentioned earlier - no issues whatsoever), the more these -32768 values are starting to occur in further consecutive readings.

For example, all of sudden, after ten hours of connection uptime, I can see getting “nonstop” -32768 values in these readings for a longer period of time (half hour, hour), with no “standard” values (which in my case are in average 12-14dB) in-between.

Re-enabling the connection or running SpeedTest partially “corrects” the issue - the readings return back to my average 12-14dB but with -32768 values here and there.

Either way, to me, -32768 value looks invalid. So I strongly suspect that something is off here.

Thanks for looking into it.

Can you provide related logs or screenshots?

Here you are:

^ That was from yesterday. Now, I am attaching newest from today after ~15 hours of session uptime, and the -32768 SINR reading is still there for almost a hour now and doesn’t want to change:

This clearly doesn’t look normal.

@herbert.pan-Q Have you had the time to look into it? It’s still reporting this strange -32768 values. For real SINR monitoring, it’s totally unusable. Thanks in advance.

I think the output result is normal, the current LTE gives invalid value, NR5G output is normal value; You can try to lock the current network to LTE and then print the SINR results

I disagree. Let me finally give you my three arguments why I think it’s wrong:

  1. Another user on this same forum has reported the very same problem (with his 5G Quectel modem, albeit different model) where he reported this issue wasn’t there with previous firmware.

  2. Before I switched to RG520F-EU, I had been using Quectel EG12-EA which had been literally cell-locked with every connection to the very same bands (B1, B3, B28) and very same BTS for almost three years, and I never ever had such invalid readings of SINR value (-32768).

  3. Reading your own Quectel_RG50xQ&RM5xxQ_Series_AT_Commands_Manual_V1.1.1 PDF, the SINR metric, across the manual, for both LTE or 5G NR must be within range -20 to 30dB (!!) - this simply implies -32768 value for SINR is invalid:

Also, never ever in this document is a -32768 value mentioned.

Can you please acknowledge this is a real issue and have your engineers look into it? Thank you very much.

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My MikroTik Chateau 5G R16 (RG520F-EU) has just received a firmware updated that seems to have fixed the SINR readings.

@nicsmith1979 Thanks, that’s great to hear, I will try it too. What is your current FW version then?

@MikeyJay FW version is RG520FEUEAR03A04M4G, it took a while to update.

I managed to update to the latest firmware today, and with 5 hours of uptime with this firmware (RG520FEUEAR03A04M4G), I can report no more “invalid” SINR readings. So it seems this issue has been fixed there.