Cannot connect to T-Mobile NB-IoT on NRF9160

[lbeckwit]

Hello!

I have been trying to connect to T-Mobile's NB-IoT network using a NRF9160DK with a Twilio Narrowband sim, but have been unsuccessful so far. I have been able to successfully run applications on LTE connections using both a Twilio sim on T-Mobile's network as well as with an iBasis sim, but when I switch to NB-IoT it does not work properly. I am located in northern VA near DC and T-Mobile does have NB-IoT coverage here.

I was looking over past threads and found this one: https://devzone.nordicsemi.com/f/nordic-q-a/61681/nrf9160-doesn-t-connect-over-nb-iot-ibasis-and-t-mobile-works-fine-on-cat-m, which seems to conclude that T-Mobile does not allow Nordic boards to connect to their network. However that was 2 years ago.

Does anyone know if T-Mobile allows Nordic boards to connect to their NB-IoT network, and if not are there any other services in the US that work for NB-IoT?

Thanks!

[helsing]

Hi Luke,

Thank you for your request. We will get back to you tomorrow or over the weekend.

Best regards,

Håkon

[lbeckwit]

Hello Håkon,

Thanks for the note, are there any updates?

Thanks,

Luke

[Charlie]

Hi Luke,

We have got the certifications with the T-Mobile US NB-IoT network and connection should not be an issue.

Which kind of test have you done by far? Can you maybe play with AT commands and share the log files?

Feel free to contact our local sales team to get more localized advice for your development.

Best regards,

Charlie

[lbeckwit]

Hi Charlie, thanks for the reply.

Glad to hear that T-Mobile should support the NRF board. Here is the log from Nordic's LTE Link Monitor for what I understand the commands for setting the mode to NB-IoT to be.

The commands I run to set the mode are:

AT+CGDCONT=1,"IP","iot.nb"

AT%XSYSTEMMODE=0,1,1,0

and then I turn the modem on and waited to see if it connects. The board sees the T-Mobile network (it is listed as "available" when I search for networks) but does not connection. I have tried some of the solutions posted on other questions, but none seem to have solved the problem.

2022-04-28T17:23:46.289Z DEBUG Application data folder: /home/luke/.config/nrfconnect/pc-nrfconnect-linkmonitor
2022-04-28T17:23:46.317Z INFO Using nrf-device-lib-js version: 0.4.5
2022-04-28T17:23:46.318Z INFO Using nrf-device-lib version: 0.11.0
2022-04-28T17:23:46.318Z INFO Using nrfjprog DLL version: 10.15.1
2022-04-28T17:23:46.318Z INFO Using JLink version: JLink_V7.60f
2022-04-28T17:23:46.354Z DEBUG App pc-nrfconnect-linkmonitor v2.0.1 official
2022-04-28T17:23:46.354Z DEBUG App path: /home/luke/.nrfconnect-apps/node_modules/pc-nrfconnect-linkmonitor
2022-04-28T17:23:46.354Z DEBUG nRFConnect 3.11.0, required by the app is (^3.8.0)
2022-04-28T17:23:46.354Z DEBUG nRFConnect path: /tmp/.mount_nrfconmF5iG5/resources/app.asar
2022-04-28T17:23:46.354Z DEBUG HomeDir: /home/luke
2022-04-28T17:23:46.354Z DEBUG TmpDir: /tmp
2022-04-28T17:23:46.355Z INFO Installed JLink version does not match the provided version (V7.58b)
2022-04-28T17:24:05.570Z INFO Modem port is opened
2022-04-28T17:24:05.575Z DEBUG modem >> AT+CFUN?
2022-04-28T17:24:05.590Z DEBUG modem << +CFUN: 0
2022-04-28T17:24:05.592Z DEBUG modem << OK
2022-04-28T17:24:13.751Z DEBUG modem >> AT+CFUN=4
2022-04-28T17:24:13.761Z DEBUG modem << OK
2022-04-28T17:24:26.665Z DEBUG modem >> AT+CGDCONT=1,"IP","iot.nb"
2022-04-28T17:24:26.677Z DEBUG modem << OK
2022-04-28T17:24:36.768Z DEBUG modem >> AT%XSYSTEMMODE=0,1,1,0
2022-04-28T17:24:36.781Z DEBUG modem << OK
2022-04-28T17:24:39.856Z DEBUG modem >> AT+CFUN?
2022-04-28T17:24:39.867Z DEBUG modem << +CFUN: 4
2022-04-28T17:24:39.871Z DEBUG modem << OK
2022-04-28T17:24:39.872Z DEBUG modem >> AT+CFUN=1
2022-04-28T17:24:39.905Z DEBUG modem << OK
2022-04-28T17:24:42.304Z DEBUG modem >> AT+CFUN?
2022-04-28T17:24:42.309Z DEBUG modem << +CFUN: 1
2022-04-28T17:24:42.314Z DEBUG modem << OK
2022-04-28T17:24:42.316Z DEBUG modem >> AT+CGSN=1
2022-04-28T17:24:42.322Z DEBUG modem << +CGSN: "352656106682878"
2022-04-28T17:24:42.323Z DEBUG modem << OK
2022-04-28T17:24:42.325Z DEBUG modem >> AT+CGMI
2022-04-28T17:24:42.330Z DEBUG modem << Nordic Semiconductor ASA
2022-04-28T17:24:42.332Z DEBUG modem << 
2022-04-28T17:24:42.332Z DEBUG modem << OK
2022-04-28T17:24:42.334Z DEBUG modem >> AT+CGMM
2022-04-28T17:24:42.339Z DEBUG modem << nRF9160-SICA
2022-04-28T17:24:42.340Z DEBUG modem << 
2022-04-28T17:24:42.340Z DEBUG modem << OK
2022-04-28T17:24:42.342Z DEBUG modem >> AT+CGMR
2022-04-28T17:24:42.346Z DEBUG modem << mfw_nrf9160_1.3.1
2022-04-28T17:24:42.347Z DEBUG modem << OK
2022-04-28T17:24:42.347Z INFO Nordic Semiconductor ASA nRF9160-SICA [mfw_nrf9160_1.3.1] SerNr: 352656106682878
2022-04-28T17:24:42.348Z DEBUG modem >> AT+CEMODE?
2022-04-28T17:24:42.353Z DEBUG modem << +CEMODE: 0
2022-04-28T17:24:42.353Z DEBUG modem << 
2022-04-28T17:24:42.354Z DEBUG modem << OK
2022-04-28T17:24:42.357Z DEBUG modem >> AT%XCBAND=?
2022-04-28T17:24:42.365Z DEBUG modem << %XCBAND: (1,2,3,4,5,8,12,13,17,19,20,25,26,28,66)
2022-04-28T17:24:42.365Z DEBUG modem << 
2022-04-28T17:24:42.366Z DEBUG modem << OK
2022-04-28T17:24:42.370Z DEBUG modem >> AT+CMEE?
2022-04-28T17:24:42.374Z DEBUG modem << +CMEE: 0
2022-04-28T17:24:42.375Z DEBUG modem << OK
2022-04-28T17:24:42.377Z DEBUG modem >> AT+CMEE=1
2022-04-28T17:24:42.380Z DEBUG modem << OK
2022-04-28T17:24:42.382Z DEBUG modem >> AT+CNEC?
2022-04-28T17:24:42.386Z DEBUG modem << +CNEC: 0
2022-04-28T17:24:42.387Z DEBUG modem << OK
2022-04-28T17:24:42.388Z DEBUG modem >> AT+CNEC=24
2022-04-28T17:24:42.392Z DEBUG modem << OK
2022-04-28T17:24:42.394Z DEBUG modem >> AT+CGEREP?
2022-04-28T17:24:42.398Z DEBUG modem << +CGEREP: 0,0
2022-04-28T17:24:42.399Z DEBUG modem << OK
2022-04-28T17:24:42.401Z DEBUG modem >> AT+CGDCONT?
2022-04-28T17:24:42.407Z DEBUG modem << +CGDCONT: 1,"IP","iot.nb","",0,0
2022-04-28T17:24:42.408Z DEBUG modem << OK
2022-04-28T17:24:42.413Z DEBUG modem >> AT+CGACT?
2022-04-28T17:24:42.417Z DEBUG modem << +CGACT: 1,0
2022-04-28T17:24:42.420Z DEBUG modem << OK
2022-04-28T17:24:42.423Z DEBUG modem >> AT+CGEREP=1
2022-04-28T17:24:42.427Z DEBUG modem << OK
2022-04-28T17:24:42.430Z DEBUG modem >> AT+CIND=1,1,1
2022-04-28T17:24:42.434Z DEBUG modem << OK
2022-04-28T17:24:42.435Z DEBUG modem >> AT+CEREG=5
2022-04-28T17:24:42.439Z DEBUG modem << OK
2022-04-28T17:24:42.440Z DEBUG modem >> AT+CEREG?
2022-04-28T17:24:42.444Z DEBUG modem << +CEREG: 5,4
2022-04-28T17:24:42.447Z DEBUG modem << 
2022-04-28T17:24:42.447Z DEBUG modem << OK
2022-04-28T17:24:42.451Z DEBUG modem >> AT%CESQ=1
2022-04-28T17:24:42.454Z DEBUG modem << OK
2022-04-28T17:24:42.455Z DEBUG modem >> AT+CESQ
2022-04-28T17:24:42.460Z DEBUG modem << +CESQ: 99,99,255,255,255,255
2022-04-28T17:24:42.461Z DEBUG modem << 
2022-04-28T17:24:42.461Z DEBUG modem << OK
2022-04-28T17:24:42.466Z DEBUG modem >> AT%XSIM=1
2022-04-28T17:24:42.470Z DEBUG modem << OK
2022-04-28T17:24:42.471Z DEBUG modem >> AT%XSIM?
2022-04-28T17:24:42.475Z DEBUG modem << %XSIM: 1
2022-04-28T17:24:42.476Z DEBUG modem << 
2022-04-28T17:24:42.477Z DEBUG modem << OK
2022-04-28T17:24:42.484Z DEBUG modem >> AT+CPIN?
2022-04-28T17:24:42.487Z DEBUG modem << +CPIN: READY
2022-04-28T17:24:42.488Z DEBUG modem << 
2022-04-28T17:24:42.488Z DEBUG modem << OK
2022-04-28T17:24:42.491Z DEBUG modem >> AT+CPINR="SIM PIN"
2022-04-28T17:24:42.501Z DEBUG modem << +CPINR: "SIM PIN",3
2022-04-28T17:24:42.502Z DEBUG modem << 
2022-04-28T17:24:42.503Z DEBUG modem << OK
2022-04-28T17:24:42.506Z DEBUG modem >> AT+CIMI
2022-04-28T17:24:42.511Z DEBUG modem << 310240200029948
2022-04-28T17:24:42.511Z DEBUG modem << OK
2022-04-28T17:24:42.512Z INFO IMSIdentity: 310240200029948
2022-04-28T17:25:20.345Z DEBUG modem >> AT%XMONITOR
2022-04-28T17:25:20.351Z DEBUG modem << %XMONITOR: 4
2022-04-28T17:25:20.352Z DEBUG modem << OK
2022-04-28T17:25:45.532Z DEBUG modem >> AT+COPS=?
2022-04-28T17:26:41.865Z DEBUG modem << %CESQ: 50,2,26,3
2022-04-28T17:26:41.867Z DEBUG modem << +CEREG: 2,"1305","09FA9439",9
2022-04-28T17:26:41.868Z DEBUG modem << 
2022-04-28T17:26:42.406Z DEBUG modem << +CNEC_EMM: 15
2022-04-28T17:26:42.409Z DEBUG modem << +CEREG: 2,"1305","09FA9439",9,0,15
2022-04-28T17:26:43.438Z DEBUG modem << %CESQ: 255,0,255,0
2022-04-28T17:26:43.440Z DEBUG modem << 
2022-04-28T17:26:43.440Z DEBUG modem << +CEREG: 2
2022-04-28T17:26:44.425Z DEBUG modem << %CESQ: 57,2,28,4
2022-04-28T17:26:44.428Z DEBUG modem << +CEREG: 2,"7581","01C9650A",9
2022-04-28T17:26:45.935Z DEBUG modem << +CNEC_EMM: 11
2022-04-28T17:26:45.938Z DEBUG modem << +CEREG: 2,"7581","01C9650A",9,0,11
2022-04-28T17:26:45.939Z DEBUG modem << 
2022-04-28T17:26:46.639Z DEBUG modem << %CESQ: 57,2,23,3
2022-04-28T17:26:46.677Z DEBUG modem << %CESQ: 255,0,255,0
2022-04-28T17:26:46.678Z DEBUG modem << 
2022-04-28T17:26:46.970Z DEBUG modem << %CESQ: 50,2,22,3
2022-04-28T17:26:46.972Z DEBUG modem << +CEREG: 2
2022-04-28T17:27:00.242Z DEBUG modem << %CESQ: 255,0,255,0
2022-04-28T17:27:04.945Z DEBUG modem << %CESQ: 10,0,6,0
2022-04-28T17:27:04.950Z DEBUG modem << 
2022-04-28T17:27:04.951Z DEBUG modem << +CEREG: 2,"EE14","00AF22C9",9
2022-04-28T17:27:07.666Z DEBUG modem << %CESQ: 11,0,11,1
2022-04-28T17:27:07.668Z DEBUG modem << 
2022-04-28T17:27:09.830Z DEBUG modem << %CESQ: 8,0,5,0
2022-04-28T17:27:09.832Z DEBUG modem << 
2022-04-28T17:27:10.430Z DEBUG modem << %CESQ: 6,0,0,0
2022-04-28T17:27:10.432Z DEBUG modem << 
2022-04-28T17:27:12.031Z DEBUG modem << %CESQ: 9,0,7,1
2022-04-28T17:27:12.033Z DEBUG modem << 
2022-04-28T17:27:15.600Z DEBUG modem << +CNEC_EMM: 6
2022-04-28T17:27:15.602Z DEBUG modem << +CEREG: 0
2022-04-28T17:27:16.403Z DEBUG modem << %CESQ: 6,0,0,0
2022-04-28T17:27:17.102Z DEBUG modem << %CESQ: 9,0,7,1
2022-04-28T17:27:17.104Z DEBUG modem << 
2022-04-28T17:27:27.342Z DEBUG modem << %CESQ: 0,0,0,0
2022-04-28T17:27:27.344Z DEBUG modem << 
2022-04-28T17:27:32.463Z DEBUG modem << %CESQ: 6,0,1,0
2022-04-28T17:27:32.464Z DEBUG modem << 
2022-04-28T17:27:55.505Z DEBUG modem << %CESQ: 13,0,13,1
2022-04-28T17:27:55.506Z DEBUG modem << 
2022-04-28T17:28:05.744Z DEBUG modem << %CESQ: 2,0,0,0
2022-04-28T17:28:05.746Z DEBUG modem << 
2022-04-28T17:28:08.304Z DEBUG modem << %CESQ: 9,0,9,1
2022-04-28T17:28:13.424Z DEBUG modem << %CESQ: 4,0,0,0
2022-04-28T17:28:15.984Z DEBUG modem << %CESQ: 9,0,5,0
2022-04-28T17:28:18.544Z DEBUG modem << %CESQ: 4,0,0,0
2022-04-28T17:28:39.024Z DEBUG modem << %CESQ: 9,0,6,0
2022-04-28T17:28:39.026Z DEBUG modem << 
2022-04-28T17:28:46.704Z DEBUG modem << %CESQ: 3,0,0,0
2022-04-28T17:29:02.064Z DEBUG modem << %CESQ: 9,0,4,0
2022-04-28T17:29:04.624Z DEBUG modem << %CESQ: 3,0,0,0
2022-04-28T17:29:22.956Z DEBUG modem << %CESQ: 12,0,10,1
2022-04-28T17:29:25.102Z DEBUG modem << %CESQ: 8,0,5,0
2022-04-28T17:29:25.104Z DEBUG modem << 
2022-04-28T17:29:30.222Z DEBUG modem << %CESQ: 0,0,0,0
2022-04-28T17:29:35.342Z DEBUG modem << %CESQ: 12,0,12,1
2022-04-28T17:29:36.408Z DEBUG modem << %CESQ: 255,0,255,0
2022-04-28T17:29:36.409Z DEBUG modem << 
2022-04-28T17:29:36.415Z DEBUG modem << +COPS: (1,"","","310260",9),(1,"","","310410",9),(3,"","","311480",9)
2022-04-28T17:29:36.417Z DEBUG modem << OK
2022-04-28T17:29:36.421Z DEBUG modem >> AT+CFUN?
2022-04-28T17:29:36.425Z DEBUG modem << +CFUN: 1
2022-04-28T17:29:36.429Z DEBUG modem << OK
2022-04-28T17:29:36.435Z DEBUG modem >> AT%XMONITOR
2022-04-28T17:29:36.448Z DEBUG modem << %XMONITOR: 0
2022-04-28T17:29:36.449Z DEBUG modem << OK
2022-04-28T17:29:36.450Z DEBUG modem >> AT%XMONITOR
2022-04-28T17:29:36.456Z DEBUG modem << %XMONITOR: 0
2022-04-28T17:29:36.457Z DEBUG modem << OK
2022-04-28T17:29:36.458Z DEBUG modem >> AT+COPS?
2022-04-28T17:29:36.466Z DEBUG modem << +COPS: 0
2022-04-28T17:29:36.467Z DEBUG modem << 
2022-04-28T17:29:36.468Z DEBUG modem << OK
2022-04-28T17:29:36.472Z DEBUG modem >> AT+CGSN=1
2022-04-28T17:29:36.477Z DEBUG modem << +CGSN: "352656106682878"
2022-04-28T17:29:36.478Z DEBUG modem << 
2022-04-28T17:29:36.478Z DEBUG modem << OK
2022-04-28T17:29:36.480Z DEBUG modem >> AT+CGMI
2022-04-28T17:29:36.487Z DEBUG modem << Nordic Semiconductor ASA
2022-04-28T17:29:36.488Z DEBUG modem << 
2022-04-28T17:29:36.488Z DEBUG modem << OK
2022-04-28T17:29:36.489Z DEBUG modem >> AT+CGMM
2022-04-28T17:29:36.497Z DEBUG modem << nRF9160-SICA
2022-04-28T17:29:36.497Z DEBUG modem << OK
2022-04-28T17:29:36.499Z DEBUG modem >> AT+CGMR
2022-04-28T17:29:36.507Z DEBUG modem << mfw_nrf9160_1.3.1
2022-04-28T17:29:36.508Z DEBUG modem << OK
2022-04-28T17:29:36.508Z INFO Nordic Semiconductor ASA nRF9160-SICA [mfw_nrf9160_1.3.1] SerNr: 352656106682878
2022-04-28T17:29:36.510Z DEBUG modem >> AT+CEMODE?
2022-04-28T17:29:36.516Z DEBUG modem << +CEMODE: 0
2022-04-28T17:29:36.517Z DEBUG modem << 
2022-04-28T17:29:36.517Z DEBUG modem << OK
2022-04-28T17:29:36.520Z DEBUG modem >> AT%XCBAND=?
2022-04-28T17:29:36.531Z DEBUG modem << %XCBAND: (1,2,3,4,5,8,12,13,17,19,20,25,26,28,66)
2022-04-28T17:29:36.532Z DEBUG modem << OK
2022-04-28T17:29:36.535Z DEBUG modem >> AT+CMEE?
2022-04-28T17:29:36.544Z DEBUG modem << +CMEE: 1
2022-04-28T17:29:36.545Z DEBUG modem << OK
2022-04-28T17:29:36.548Z DEBUG modem >> AT+CNEC?
2022-04-28T17:29:36.556Z DEBUG modem << +CNEC: 24
2022-04-28T17:29:36.557Z DEBUG modem << 
2022-04-28T17:29:36.558Z DEBUG modem << OK
2022-04-28T17:29:36.560Z DEBUG modem >> AT+CGEREP?
2022-04-28T17:29:36.567Z DEBUG modem << +CGEREP: 1,0
2022-04-28T17:29:36.568Z DEBUG modem << OK
2022-04-28T17:29:36.570Z DEBUG modem >> AT+CIND=1,1,1
2022-04-28T17:29:36.576Z DEBUG modem << OK
2022-04-28T17:29:36.578Z DEBUG modem >> AT+CEREG=5
2022-04-28T17:29:36.586Z DEBUG modem << OK
2022-04-28T17:29:36.588Z DEBUG modem >> AT+CEREG?
2022-04-28T17:29:36.598Z DEBUG modem << +CEREG: 5,0
2022-04-28T17:29:36.599Z DEBUG modem << OK
2022-04-28T17:29:36.603Z DEBUG modem >> AT%CESQ=1
2022-04-28T17:29:36.607Z DEBUG modem << OK
2022-04-28T17:29:36.609Z DEBUG modem >> AT+CESQ
2022-04-28T17:29:36.619Z DEBUG modem << +CESQ: 99,99,255,255,255,255
2022-04-28T17:29:36.620Z DEBUG modem << OK
2022-04-28T17:29:36.624Z DEBUG modem >> AT%XSIM=1
2022-04-28T17:29:36.634Z DEBUG modem << OK
2022-04-28T17:29:36.636Z DEBUG modem >> AT%XSIM?
2022-04-28T17:29:36.648Z DEBUG modem << %XSIM: 1
2022-04-28T17:29:36.649Z DEBUG modem << OK
2022-04-28T17:29:36.655Z DEBUG modem >> AT+CPIN?
2022-04-28T17:29:36.665Z DEBUG modem << +CPIN: READY
2022-04-28T17:29:36.665Z DEBUG modem << 
2022-04-28T17:29:36.665Z DEBUG modem << OK
2022-04-28T17:29:36.668Z DEBUG modem >> AT+CPINR="SIM PIN"
2022-04-28T17:29:36.681Z DEBUG modem << +CPINR: "SIM PIN",3
2022-04-28T17:29:36.682Z DEBUG modem << OK
2022-04-28T17:29:36.687Z DEBUG modem >> AT+CIMI
2022-04-28T17:29:36.695Z DEBUG modem << 310240200029948
2022-04-28T17:29:36.698Z DEBUG modem << 
2022-04-28T17:29:36.699Z DEBUG modem << OK
2022-04-28T17:29:36.700Z INFO IMSIdentity: 310240200029948
2022-04-28T17:30:30.305Z DEBUG modem >> AT%XMONITOR
2022-04-28T17:30:30.316Z DEBUG modem << %XMONITOR: 0
2022-04-28T17:30:30.317Z DEBUG modem << OK

[Charlie]

Hi Luke,

Thanks for sharing. I did not find anything wrong in this log, so next step I want you to record a mode trace for deeper level analysis.

I also found a similar case two years ago, and ATTACH is rejected with cause 6 (Illegal ME) in T-Mobile network due to nRF9160 did not have certification to their network at that time. Not sure if there are any other issues exist, so I have sent a message to check with our local FAE.

NRF9160 doesn't connect over NB-IoT (iBasis and T-mobile, works fine on Cat-M) - Nordic Q&A - Nordic DevZone - Nordic DevZone (nordicsemi.com)

Best regards,

Charlie