What is the best method to ensure the nRF9160 LTE functions on a PCB during assembly with minimal test equipment?
Our thoughts were to search for available networks using AT+COPS=? as it doesn't require a SIM, let alone a SIM card with CAT-M1/NB-IOT access.
I have this working in Australia, but it doesn't appear to be finding any networks in China.
We are issuing:
AT%XSYSTEMMODE=1,1,1,2
to ensure both CAT-M1 and NB-IOT is enabled. I understand China has a preference to deploy NB-IOT networks rather than CAT-M1.
Then we issue AT+COPS=?. In Australia it returns a list of one CAT-M1 network (Telstra) and CAT-NBIoT networks from Telstra and Optus. In China we are getting nothing.
I understand China Mobile had deployed NB-IoT on band 8, China Telecom on 5 and China Unicom on Bands 3 & 8. Our antenna supports all these bands.
We are using new modules loaded with mfw_nrf9160_1.3.6 not the PTI (Production Test Image). It appeared all the bands are enabled - certainly XBANDLOCK was reporting no locked bands.