[MC7455] no network service / registration denied

IoT Modules MC/EM Series
1

Been working with this modem on and off for a couple months to no avail.

First, I’m trying to use this with Ting. Despite saying the IMEI worked on their system, they weren’t entirely sure which SIM it should use. I currently have a Sprint NanoSIM C7. The Ting site says everything is active.

I’ve tried Generic firmware (02.24.05.06) and Sprint firmware (02.26.01.00). The furthest I’ve gotten came by way of the commands in this post from Howard Forums using generic.

I’m currently using a Mini PCI-E to USB adapter with SIM card slot in Windows 10. Ultimately, it will go in a Linux box. The Windows networking interface identifies it as “Sprint” but says “No service.”

Believing the result of AT+CGREG? and this site, the registration is being denied. Does that mean a SIM issue or not authorized on the network? It’s probably something stupid or simple that I’m missing.

Thanks in advance!

ATI
Manufacturer: Sierra Wireless, Incorporated
Model: MC7455
Revision: SWI9X30C_02.24.05.06 r7040 CARMD-EV-FRMWR2 2017/05/19 06:23:09
MEID: XXXXXXXXXXXXXX
IMEI: XXXXXXXXXXXXXXX
IMEI SV: 12
FSN: XXXXXXXXXXXXXX
+GCAP: +CGSM


OK
AT!USBCOMP?
Config Index: 1
Config Type:  1 (Generic)
Interface bitmask: 00001009 (diag,modem,mbim)

OK
AT!GOBIIMPREF?
!GOBIIMPREF:
 preferred fw version:    02.24.05.06
 preferred carrier name:  GENERIC
 preferred config name:   GENERIC_002.026_000
 current fw version:      02.24.05.06
 current carrier name:    GENERIC
 current config name:     GENERIC_002.026_000

OK
AT!GSTATUS?
!GSTATUS:
Current Time:  1005             Temperature: 21
Reset Counter: 1                Mode:        ONLINE
System mode:   LTE              PS state:    Not attached
LTE band:      B41              LTE bw:      20 MHz
LTE Rx chan:   41176            LTE Tx chan: 4294967295
LTE CA state:  NOT ASSIGNED
EMM state:     Deregistered     Attach Needed
RRC state:     RRC Idle
IMS reg state: No Srv

PCC RxM RSSI:  -85              RSRP (dBm):  -119
PCC RxD RSSI:  -84              RSRP (dBm):  -114
Tx Power:      0                TAC:         4103 (16643)
RSRQ (dB):     -10.5            Cell ID:     08364304 (137773828)
SINR (dB):      2.8


OK
AT+CPIN?
+CPIN: READY

OK
AT+CGREG?
+CGREG: 0,3

OK
AT+COPS?
+COPS: 0

OK
AT+CSQ
+CSQ: 14,99

OK
AT+cgatt=1
+CME ERROR: no network service
ATDT#777
NO CARRIER
2

Hi,

There are a number of points below in your posting that might need looking at.

  • You mention Ting and Sprint, I presume Ting is an MVNO that piggybacks onto Sprint?
  • You mention CDMA in the posting, obviously the MC7455 is not CDMA capable, it is purely LTE (and 3G). Is the SIM enabled for LTE?
  • If you are using Sprint do you need to use their approved release? It might be this reason the unit is not attaching.
  • The CGREG: 3 response indicates ‘unknown’, generally this means that the unit has sent an attach request to the network but has not received a response.
  • The manual attempt to force an attach is interesting but you do not know what it is trying to attach to you would be better off forcing and attach to something you can point a finger at. I would try the following
at+cmee=1
at+cops=?      This will take a couple of minutes to complete.
at+cops=1,2,"xxxxx",7       //Manaully force an attach to a network returned from the above command where xxxxx is the MNC/MCC for the network you want

The above will at least give you an error code to work with. You can clearly see a network at the moment you just don’t know which one.

Regards

Matt

3

Correct.

CDMA was from the device status page on the Ting website. Regardless, this is going to be my problem - I did not catch this issue. OMG. When I first called their support, they said ‘another customer has your device and is using the [Sprint] C7 SIM card.’ The Sprint C7 SIM itself doesn’t specifically say CDMA on it but it is listed under the CDMA SIM cards on their website. Now when I check the IMEI, it does say GSM on the BYOD page. I have ordered a GSM SIM.

I have done both. The Howard Forums post I linked suggested the generic works best. Doesn’t matter anymore as Ting’s GSM is over T-Mobile’s network.

Thanks again for the help. The GSM SIM should fix my problems. Lesson learned.