Unable to Connect Quectel RM50xQ Modem to 5G Network

Hi,
I am trying to connect the Quectel RM50xQ modem with the Sixfab 5G Development Kit but cannot establish a connection to the 5G network. I am based in Finland and have tested both DNA and Elisa SIM cards, but the modem fails to register on the network.

Could you please guide me on:

  1. Additional configuration steps or AT commands to resolve the issue.
  2. Troubleshooting SIM compatibility or network restrictions.
  3. Whether firmware or driver updates are required to use the modem.

Any advice or references to similar cases would be highly appreciated.

Thank you!

Asifa

I am getting this type of error in at command,

AT+COPS=?
+COPS: (1,“FI DNA”,“DNA”,“24412”,12),(0-4),(0-2)

OK
AT+COPS=1,2,“24412”
OK
AT+COPS?
+COPS: 1

OK
AT+CSQ
+CSQ: 99,99

OK
AT+QENG=“servingcell”
+QENG: “servingcell”,“SEARCH”

OK

AT+CSQ
+CSQ: 99,99

OK
AT+QENG=“servingcell”
+QENG: “servingcell”,“SEARCH”

OK
AT+QCFG=“nwscanmode”,3
ERROR
AT+COPS?
+COPS: 1

OK
AT+CSQ
+CSQ: 99,99

OK
AT+QNWPREFCFG=“nr5g_band”
+QNWPREFCFG: “nr5g_band”,41:77:78

OK
AT+QNWPREFCFG=“nr5g_band”
+QNWPREFCFG: “nr5g_band”,41:77:78

OK
AT+QNWPREFCFG=“nr5g_band”,“78”
ERROR
AT+QNWPREFCFG=“nr5g_band”
+QNWPREFCFG: “nr5g_band”,41:77:78

OK
AT+QNWPREFCFG=“nr5g_band”
+QNWPREFCFG: “nr5g_band”,41:77:78

OK
AT+QNWPREFCFG=“nr5g_band”,“1:2:3:5:7:8:12:20:25:28:38:40:41:48:66:71:77:78:79”
ERROR
AT+QCFG=“nwscanmode”,1
ERROR
AT+QCFG=“nwscanmode”,1
ERROR
AT+COPS?
+COPS: 1

OK
AT+QENG=“servingcell”
+QENG: “servingcell”,“SEARCH”

OK
AT+QCFG=“nwscanmode”,3
ERROR
AT+QNWPREFCFG=“reset”
ERROR
AT+CGMR
RM502QAEAAR11A04M4G

OK

Hi,

Thank you for detailing your issue!

Your AT command outputs show the modem is stuck in “SEARCH” mode (+QENG: “servingcell”,“SEARCH”) and reports no signal (+CSQ: 99,99). First, ensure the SIM cards are 5G-enabled and the antennas are properly connected with a clear line of sight, as Finland’s DNA and Elisa use bands like n78 (supported by your modem’s +QNWPREFCFG: “nr5g_band”,41:77:78”). Try resetting the modem with AT+CFUN=1,1 and set it to auto-select the network with AT+COPS=0, then check signal again with AT+CSQ and AT+QENG=“servingcell”.

The AT+QCFG=“nwscanmode” errors suggest a syntax issue; use AT+QCFG=“nwscanmode”,0 for auto mode instead. For SIM compatibility, confirm with DNA and Elisa that your plans support 5G Standalone (SA) or Non-Standalone (NSA) modes, as your modem supports both. Let us know the results or any new errors for further assistance!

Hi @ensar thanks for your reply. The modem is detected, but the network interface (usb0 or wwan0) is unavailable, and 5G registration isn’t stable(it only shows 4G ).

I am attaching logs and error messages that might help diagnose the issue. It will be really helpful if you could guide me what should i do next …

rasp@raspberrypi:~ $ ifconfig usb0
usb0: error fetching interface information: Device not found
rasp@raspberrypi:~ $ ifconfig -a
eth0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
ether 2c:cf:67:89:16:f8 txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device interrupt 106

lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10
loop txqueuelen 1000 (Local Loopback)
RX packets 98 bytes 8664 (8.4 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 98 bytes 8664 (8.4 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

wlan0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 130.230.176.21 netmask 255.255.252.0 broadcast 130.230.179.255
inet6 fe80::2919:128b:2db5:9934 prefixlen 64 scopeid 0x20
ether 2c:cf:67:89:16:f9 txqueuelen 1000 (Ethernet)
RX packets 1215 bytes 420903 (411.0 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 1334 bytes 653833 (638.5 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

and Mnicom

AT+QCFG=“usbnet”

+QCFG: “usbnet”,1

OK
AT+CPIN?
+CPIN: READY

OK
AT+CEREG?
+CEREG: 0,1

OK
AT+CGCONTRDP
+CGCONTRDP: 1,5,internet,10.141.20.66,62.241.198.245,62.241.198.246

OK
AT+CGDCONT=1,“IPV4V6”,“internet”

OK

AT+CSQ

+CSQ: 27,99

OK

AT+QPING=1,“8.8.8.8”

OK

+QPING: 0,“8.8.8.8”,32,41,255

+QPING: 0,“8.8.8.8”,32,37,255

+QPING: 0,“8.8.8.8”,32,19,255

+QPING: 0,“8.8.8.8”,32,20,255

+QPING: 0,4,4,0,19,41,29

AT+QENG=“servingcell”

+QENG: “servingcell”,“NOCONN”,“LTE”,“FDD”,244,12,1FD502,301,1598,3,5,5,141,-102,-20,-58,4,0,-,29

OK

AT+QENDC

+QENDC: 1,1,0,1,0

OK

AT+QENG=“neighbourcell”

+QENG: “neighbourcell intra”,“LTE”,1598,301,-20,-102,-58,-,29,6,20,12,62

+QENG: “neighbourcell inter”,“LTE”,6200,-,-,-,-,-,29,4,6,10

+QENG: “neighbourcell inter”,“LTE”,2850,-,-,-,-,-,0,5,6,10

+QENG: “neighbourcell inter”,“LTE”,300,-,-,-,-,-,0,5,6,10

OK

AT+QNWPREFCFG=“mode_pref”,NR5G

OK

+QIURC: “pdpdeact”,1

AT+QNWPREFCFG=“mode_pref”,LTE:NR5G

OK

AT+C5GREG?

+C5GREG: 0,0

OK

AT+C5GREG?

+C5GREG: 0,0

OK

AT+QENDC

ERROR