BG95M3 How to connect to network

I buy a BG95-M3 USB dongle module to study IoT feature. But I cannot connect to GSM network after insert China mobile SIM card. This SIM card support 2G network in China.
AT+CEREG? shows 0,4 and AT+QENG=“SERVINGCELL” shows NOCONN.
Could you please help to advise if there is exist special command to connect to network? TKS.

[13:47:22.684]发→◇AT+QGMR

[13:47:22.686]收←◆AT+QGMR
BG95M3LAR02A04_01.003.01.003

OK

[13:47:29.313]发→◇AT+QCFG=“nwscanmode”

[13:47:29.315]收←◆AT+QCFG=“nwscanmode”
+QCFG: “nwscanmode”,1

OK

[13:47:35.429]发→◇AT+CSQ

[13:47:35.431]收←◆AT+CSQ
+CSQ: 17,99

OK

[13:47:36.497]发→◇AT+QNWINFO

[13:47:36.499]收←◆AT+QNWINFO
+QNWINFO: “EDGE”,“46000”,“GSM 900”,50

OK

[13:47:37.481]发→◇AT+QENG=“SERVINGCELL”

[13:47:37.485]收←◆AT+QENG=“SERVINGCELL”
+QENG: “servingcell”,“NOCONN”,“GSM”,460,00,3375,9DF9,3,50,-79,255,255,0,24,134,1,

OK

[13:47:44.730]发→◇AT+CGDCONT?

[13:47:44.737]收←◆AT+CGDCONT?
+CGDCONT: 1,“IP”,“cmnet”,“0.0.0.0”,0,0,0

OK

[13:47:48.198]发→◇AT+QIACT?

[13:47:48.201]收←◆AT+QIACT?
OK

[13:47:58.886]发→◇AT+CEREG?

[13:47:58.889]收←◆AT+CEREG?
+CEREG: 0,4

OK

Hi @JasonHe

Please check with command AT+CREG? for CS AT+CGREG? for PS service, AT+CEREG? use for checking LTE service.
Actually the 2G network is connected, NOCONN means in IDEL stage instand of NO service.

Thanks for your help. I checked command and feedback as below, could you please help to advise?

[13:15:22.529]发→◇AT+CREG?

[13:15:22.534]收←◆
+CREG: 0,1

OK

[13:15:24.928]发→◇AT+CGREG?

[13:15:24.932]收←◆
+CGREG: 0,1

OK

[13:15:28.559]发→◇AT+CEREG?

[13:15:28.566]收←◆
+CEREG: 0,4

OK

Hi

Already connected GSM network.

Thanks for your confirmation.