Issue with RG255C-GL can't connect to network

IoT Modules 5G Module
1

I am experiencing similar issues with my RG255C-GL device on a raspberry Pi4 hat when trying to join a private network (N78 band, 20MHz) with QMI driver.

AT+QNWPREFCFG= "nr5g_band"AT+QNWPREFCFG= “nr5g_band”

+QNWPREFCFG: “nr5g_band”,78

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

OK
AT+QGMR
RG255CGLABR01A04M4G_A0.002.A0.002

OK
AT+COPS?
+COPS: 2

root@qhat20:/usr/local/bin# lsusb -t
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 5000M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/1p, 480M
|__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 1: Dev 4, If 0, Class=Vendor Specific Class, Driver=option, 480M
|__ Port 1: Dev 4, If 1, Class=Vendor Specific Class, Driver=option, 480M
|__ Port 1: Dev 4, If 2, Class=Vendor Specific Class, Driver=option, 480M
|__ Port 1: Dev 4, If 3, Class=Vendor Specific Class, Driver=qmi_wwan_q, 480M

root@qhat20:/usr/local/bin# lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 004: ID 2c7c:0316 Quectel Wireless Solutions Co., Ltd. RG255C-GL
Bus 001 Device 002: ID 2109:3431 VIA Labs, Inc. Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Should I upgrade the firmware?
Are there any specifis AT commands compared to RM500Q-GL modules? I couldn’t find the specific AT commands documentation.

Thanks
Thierry

2

Dear @turletti
I have sent the AT commands via Message, please check.

3

check AT+QPING=1,“8.8.8.8”,4,32

4

HI, can you share the configruation ? I am having problems with it too. Actually I have executed the comands you showed at the begining but still “Searching” . The network is an amarisfot 5GNSA at N78 20M
AT+QNWPREFCFG= “nr5g_band”
+QNWPREFCFG: “nr5g_band”,1:2:3:5:7:8:12:13:14:18:20:25:26:28:30:38:40:41:48:66:70:71:77:78:79

OK
AT+QGMR
RG255CGLABR01A04M4G_A0.004.A0.004

OK
AT+COPS?
+COPS: 0

OK
AT+CEREG?
+CEREG: 0,0

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

OK

5

Hi

I send below more logs. I use private 5G OAI gNB with a config n78, 20MHz.

AT+QNWPREFCFG=“nr5g_band”
+QNWPREFCFG: “nr5g_band”,78

OK
AT+QNWPREFCFG=“mode_pref”
+QNWPREFCFG: “mode_pref”,AUTO

OK
AT+QNWPREFCFG=“mode_pref”,NR5G
OK
AT+COPS=?
+COPS: (1,“Test PLMN 1-1”,“Test1-1”,“00101”,12),(0-4),(0-2)

OK
AT+CFUN=0
OK
AT+cops?
+COPS: 2

OK
AT+QNVFW=“/nv/item_files/modem/nr5g/RRC/redcap_fallback_enabled”,00
OK
at+cfun=1,1
OK

RDY

+CFUN: 1

+CPIN: READY

+QUSIM: 1
+QIND: SMS DONE

+QIND: PB DONE
AT+CFUN=0
OK
AT+CFUN=1
OK

+CPIN: READY

+QUSIM: 1

+QIND: SMS DONE

+QIND: PB DONE
AT+cops?
+COPS: 0

OK

OK
AT+QNWPREFCFG=“mode_pref”
+QNWPREFCFG: “mode_pref”,NR5G

OK
AT+COPS=?
+COPS: (1,“Test PLMN 1-1”,“Test1-1”,“00101”,12),(0-4),(0-2)

OK
AT+COPS?
+COPS: 0

OK

Best
Thierry
Your firmware is more recent than mine, so it seems that upgrading mine is not the solution.

6

Hi @turletti,

the observed effect looks somewhat similar to what has been observed by another RG255C-GL user and me with a SDX35-based device from another UE vendor here Missing enum? "Get RF Band Information" (0x0031) / "Bandwidth List" (0x12) -> Value 9.

In my case it helped to disable band n1 with the 20MHz bandwidth which made the device register to the 5G SA network on band n28 with 10MHz bandwidth.

Would it be possible to temp. switch the OAI gNB to 10MHz bandwidth for comparison?

Regards,
Reinhard

7

Dear @Jorge_Israel_Nique_T
I have sent to you via Message, please check.

8

RG255C-GL will not work in 5G NSA. You need 5G SA channel compatible with RedCap (low bandwidth, etc). It works for us in public infrastructure at n3 band and QMI driver.