Communication Issue

IoT Modules LTE Standard Module
1

We are using EC21 Cat1 and EC21EFAR06A05M4G modules.
Recently, we have been facing some communication issues with these modules. The device look like functioning but actually not and we can’t find solution. I tried some command here i attached the print out from the commands:
ATI
Quectel
EC21
Revision: EC21EFAR06A05M4G

OK
AT+CSQ
+CSQ: 99,99

OK
AT+COPS?
+COPS: 0

OK
AT+QNWINFO
+QNWINFO: No Service

OK
AT+QCFG=“BAND”
+QCFG: “band”,0xd3,0x800d5,0x0

OK
AT+QCFG=“NWSCANMODE”
ERROR
AT+QCFG=“NWSCANMODE”
+QCFG: “nwscanmode”,0

OK
AT+CFUN?
+CFUN: 1

OK
AT+CREG?
+CREG: 0,0

OK
AT+CEREG?
+CEREG: 0,0

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

OK

2

First of all, you need to check the RF or the antenna; EC21EFAR06A05M4G only supports B1/B3/B5/B7/B8/B20. Does it meet the local operator’s band requirements?

3

Our network operators are used B1 (2100 MHz), B3 (1800 MHz), and B8 (900 MHz) band

4

I suggest you check the RF circuit or the antenna.