nRF9160 Not connecting over LTE on custom board

Question

I have designed my own board, based around the nRF9160 but unfortunately I am unable to connect to an LTE network.

I am running the at_client code and using LTE Link Monitor. Below, is the log file.

2020-02-15T15:26:18.899Z DEBUG modem >> AT\x0D\x0A
2020-02-15T15:26:18.923Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:20.627Z DEBUG modem >> AT+CFUN?\x0D\x0A
2020-02-15T15:26:20.651Z DEBUG modem << +CFUN: 0\x0D\x0A
2020-02-15T15:26:20.673Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:22.754Z DEBUG modem >> AT+CFUN=1\x0D\x0A
2020-02-15T15:26:22.811Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:23.996Z DEBUG modem >> AT+CFUN?\x0D\x0A
2020-02-15T15:26:24.011Z DEBUG modem << +CFUN: 1\x0D\x0A
2020-02-15T15:26:24.024Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.035Z DEBUG modem >> AT+CGSN=1\x0D\x0A
2020-02-15T15:26:24.043Z DEBUG modem << +CGSN: "352656100636847"\x0D\x0A
2020-02-15T15:26:24.045Z DEBUG modem << OK\x0D
2020-02-15T15:26:24.055Z DEBUG modem >> AT+CGMI\x0D\x0A
2020-02-15T15:26:24.074Z DEBUG modem << Nordic Semiconductor ASA\x0D\x0A
2020-02-15T15:26:24.078Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.082Z DEBUG modem >> AT+CGMM\x0D\x0A
2020-02-15T15:26:24.094Z DEBUG modem << nRF9160-SIBA\x0D\x0A
2020-02-15T15:26:24.096Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.103Z DEBUG modem >> AT+CGMR\x0D\x0A
2020-02-15T15:26:24.123Z DEBUG modem << mfw_nrf9160_1.1.1\x0D\x0A
2020-02-15T15:26:24.126Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.129Z INFO Nordic Semiconductor ASA nRF9160-SIBA [mfw_nrf9160_1.1.1] SerNr: 352656100636847
2020-02-15T15:26:24.130Z DEBUG modem >> AT+CEMODE?\x0D\x0A
2020-02-15T15:26:24.140Z DEBUG modem << +CEMODE: 0\x0D\x0A
2020-02-15T15:26:24.143Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.160Z DEBUG modem >> AT%XCBAND=?\x0D\x0A
2020-02-15T15:26:24.171Z DEBUG modem << %XCBAND: (1,2,3,4,5,8,12,13,17,19,20,25,26,28,66)\x0D\x0A
2020-02-15T15:26:24.173Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.189Z DEBUG modem >> AT+CMEE?\x0D\x0A
2020-02-15T15:26:24.241Z DEBUG modem << +CMEE: 0\x0D\x0A
2020-02-15T15:26:24.243Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.253Z DEBUG modem >> AT+CMEE=1\x0D\x0A
2020-02-15T15:26:24.270Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.274Z DEBUG modem >> AT+CNEC?\x0D\x0A
2020-02-15T15:26:24.287Z DEBUG modem << +CNEC: 0\x0D\x0A
2020-02-15T15:26:24.295Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.319Z DEBUG modem >> AT+CNEC=24\x0D\x0A
2020-02-15T15:26:24.332Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.337Z DEBUG modem >> AT+CGEREP?\x0D\x0A
2020-02-15T15:26:24.347Z DEBUG modem << +CGEREP: 0,0\x0D\x0A
2020-02-15T15:26:24.348Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.357Z DEBUG modem >> AT+CGDCONT?\x0D\x0A
2020-02-15T15:26:24.379Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.388Z DEBUG modem >> AT+CGACT?\x0D\x0A
2020-02-15T15:26:24.395Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.405Z DEBUG modem >> AT+CGEREP=1\x0D\x0A
2020-02-15T15:26:24.411Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.413Z DEBUG modem >> AT+CIND=1,1,1\x0D\x0A
2020-02-15T15:26:24.427Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.434Z DEBUG modem >> AT+CEREG=2\x0D\x0A
2020-02-15T15:26:24.448Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.462Z DEBUG modem >> AT+CEREG?\x0D\x0A
2020-02-15T15:26:24.475Z DEBUG modem << +CEREG: 2,4,"FFFE","FFFFFFFF",9\x0D\x0A
2020-02-15T15:26:24.477Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.494Z DEBUG modem >> AT%CESQ=1\x0D\x0A
2020-02-15T15:26:24.507Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.511Z DEBUG modem >> AT+CESQ\x0D\x0A
2020-02-15T15:26:24.524Z DEBUG modem << +CESQ: 99,99,255,255,255,255\x0D\x0A
2020-02-15T15:26:24.527Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.550Z DEBUG modem >> AT%XSIM=1\x0D\x0A
2020-02-15T15:26:24.571Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.575Z DEBUG modem >> AT%XSIM?\x0D\x0A
2020-02-15T15:26:24.587Z DEBUG modem << %XSIM: 1\x0D\x0A
2020-02-15T15:26:24.590Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.605Z DEBUG modem >> AT+CPIN?\x0D\x0A
2020-02-15T15:26:24.621Z DEBUG modem << +CPIN: READY\x0D\x0A
2020-02-15T15:26:24.624Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.648Z DEBUG modem >> AT+CPINR="SIM PIN"\x0D\x0A
2020-02-15T15:26:24.683Z DEBUG modem << +CPINR: "SIM PIN",3\x0D\x0A
2020-02-15T15:26:24.686Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.693Z DEBUG modem >> AT+CIMI\x0D\x0A
2020-02-15T15:26:24.705Z DEBUG modem << 204080813513474\x0D\x0A
2020-02-15T15:26:24.707Z DEBUG modem << OK\x0D\x0A\x00
2020-02-15T15:26:24.709Z INFO IMSIdentity: 204080813513474
2020-02-15T15:26:32.419Z DEBUG modem >> AT+COPS=?\x0D\x0A
2020-02-15T15:27:32.425Z ERROR Network search failed: Error: 'AT+COPS=?
' timed out

I have used the same SIM in the nRF9160DK and I do get a connection, all be it very weak. I am only seeing 1 bar in the LTE

Link Monitor application.

The obvious difference is the layout of the two boards, however, I had the layout and schematics checked and "Ok'ed" by someone at Nordic so am quietly confident its OK.

Th other concern is the fact the signal is very weak.

I would appreciate any thought son how to move forward.

Thanks,

Rod

RodWatt · Accepted Answer

Just to to update the ticket, I have tried the system in Germany with a different NB-IOT SIM and it worked fine! Thanks again Kaja for all your advice during the antenna design and layout,

nRF9160 Not connecting over LTE on custom board

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