RM551E-GL does not work CA with Cell lock, upload CA only works when B3 PCC, lte_mimo_info bug

Arifin · January 20, 2026, 12:38pm

Hello
dear can you send
original
rm551e-gl firmware update file

arifinzamantanz279@gmail.com

silvia · January 22, 2026, 5:57am

Dear @Arifin
Please share your current firmware.

Arifin · January 22, 2026, 9:03am

RM551EGL00AAR02A02M8G
Mail : arifinzamantanz279@gmail.com

silvia · January 26, 2026, 6:30am

Dear @Arifin
Your firmware is the latest one.

Arifin · January 26, 2026, 11:16am

Mail : arifinzamantanz279@gmail.com
RM551EGL00AAR02A02M8G

Tirkiz · January 26, 2026, 11:30am

I have this one, does it have a newer FW?
RM551EGL00AAR01A04M8G_A0.001.A0.001

Based on what others are saying (RM551EGL00AAR02A02M8G) it obviously has newer FW

Thanks!

silvia · January 27, 2026, 2:32am

Dear @Arifin
Sorry, I didn’t get your point.
What is your current firmware? RM551EGL00AAR02A02M8G is the latest one.

silvia · January 27, 2026, 2:33am

Dear @Tirkiz
RM551EGL00AAR01A04M8G_A0.001.A0.001 is the latest one in R01.

For R02, as mentioned before, it is not recommended to upgrade from R01 to R02.

Tirkiz · January 27, 2026, 6:20am

Dear @silvia
What is R02? Engineering sample 2? Thanks!

silvia · January 28, 2026, 7:52am

Dear @Tirkiz
R02 is software baseline.

Tirkiz · January 28, 2026, 11:41am

Dear @silvia
Ok, but why is upgrading from R01 to R02 not recommended?

silvia · January 30, 2026, 2:14am

Dear @Tirkiz
If upgrade generally, it can’t upgrade, due to it has limitation.
There have some difference between R01 and R02.

Tirkiz · July 9, 2026, 6:24am

Again with the criticism.

These AT commands of yours are so bad it’s unbelievable.

So, when MIMO is turned off on the base station on the LTE B8 band (band B8 works in 1x1 SISO), the AT command +QNWCFG: “lte_mimo_info” shows that DL 4x4 MIMO is working on B8 all the time, which is wrong.

I checked your spec, RM551E-GL does not support DL 4x4 on low bands.

Also, a SINR bug occasionally appears on random bands, showing values above 200 (see QCAINFO SCC B3).

The tower I connect to has 4x4 MIMO actively turned on during the day on B1 and B3, but this modem never shows that it is using it in the command +QNWCFG: “lte_mimo_info” (of course, 4x4 MIMO antennas are connected). I do up to 20 TB of mobile data per month through this modem, so I believe it is loaded enough to use 4x4 at some point.

I can no longer trust the AT results that my modem returns to me because they are clearly incorrect.

+QENG: “servingcell”,“NOCONN”
+QENG: “LTE”,“FDD”,219,01,24A160A,298,500,1,5,5,1068,-94,-15,-61,18,12,190,-
+QENG: “NR5G-NSA”,219,01,739,-73,7,-11,156510,28,1,0

+QCAINFO: “PCC”,500,100,“LTE BAND 1”,1,298,-99,-15,-61,17
+QCAINFO: “SCC”,1300,100,“LTE BAND 3”,2,298,-96,-15,-58,255,0,-,-
+QCAINFO: “SCC”,3600,50,“LTE BAND 8”,2,298,-84,-14,-53,14,0,-,-
+QCAINFO: “SCC”,156510,1,“NR5G BAND 28”,739

+QNWCFG: “lte_mimo_info”,298,500,2,1
+QNWCFG: “lte_mimo_info”,298,1300,2,0
+QNWCFG: “lte_mimo_info”,298,3600,4,0

+QNWCFG: “nr5g_mimo_info”,739,156510,2,1

Modem FW:

RM551EGL00AAR01A04M8G_A0.001.A0.001

silvia · July 13, 2026, 2:31am

Dear @Tirkiz
“I checked your spec, RM551E-GL does not support DL 4x4 on low bands.”
=>Which document do you see?
I checked HD document, it showes as below:

Tirkiz · July 13, 2026, 3:23am

Dear @silvia

In your Quectel_Product_Brochure_V8.3.pdf there is no mention of MIMO so I found this picture. It does not state that it supports DL 4x4 on low bands. Everywhere on the internet this is stated from the picture where there are no low bands under DL 4x4.

Compared to your picture - the 3GPP release version doesn’t match either (your picture says release 16, but everywhere on the internet it says release 17 - which one is correct?).

Anyway, the AT command at night returns to LTE B8 with faulty MIMO because the ISP confirmed to me that then the power saver turns off MIMO, only 1x1 SISO works.

Nothing matches anything…

Tirkiz · July 14, 2026, 6:08am

Tonight MIMO is off on B8 and B3, only 1x1 SISO is working on the base station side.

Modem AT commands show that it is working 4x4 on those two bands throughout this period, which is wrong because then there would not be a drop in speed but an increase if the MIMO data is true.

+QENG: “servingcell”,“NOCONN”
+QENG: “LTE”,“FDD”,219,01,24A160A,298,500,1,5,5,1068,-93,-8,-64,15,10,190,-
+QENG: “NR5G-NSA”,219,01,739,-74,13,-10,156510,28,1,0

+QCAINFO: “PCC”,500,100,“LTE BAND 1”,1,298,-93,-7,-65,12
+QCAINFO: “SCC”,1300,100,“LTE BAND 3”,1,298,-93,-9,-76,14,0,-,-
+QCAINFO: “SCC”,3600,50,“LTE BAND 8”,1,298,-85,-16,-61,8,0,-,-
+QCAINFO: “SCC”,156510,1,“NR5G BAND 28”,739

+QNWCFG: “lte_mimo_info”,298,500,2,1
+QNWCFG: “lte_mimo_info”,298,1300,4,0
+QNWCFG: “lte_mimo_info”,298,3600,4,0

+QNWCFG: “nr5g_mimo_info”,739,156510,1,1

AT commands for LTE MIMO info and NR5G MIMO info simply give wrong data in modem FW RM551EGL00AAR01A04M8G_A0.001.A0.001