nRF9160: High signal cell tower is congested and uploads fail, how to force device to use lower signal cell tower where uploads are successful

[cole.morgan]

Our IoT device is connecting to 2 different cell towers on the same carrier. Cell tower 'A' has signal of -90dBm, tower 'B' has signal of -105dBm.

The device is mainly attempting tower A b/c of the good signal, but when it does, it sees failed registrations, receive timeouts, and socket open failures. Data uploads using lower signal tower B consistently succeed without issue.

We are using the nRF9160 with modem firmware 1.3.7, and the stock SLM for the app core. There doesn't appear to be any way to block the modem from using specific cells. Am I missing some other command we could use to force the modem onto the lower signal tower in these scenarios?

[Simonr]

There's no command to block a specific cell tower, no. For the main US carriers at least, a bad cell tower is rare, and the carriers are generally keen to fix these if one is spotted.

There are some mechanisms to try prioritizing and limiting certain cell changes like %XCOUNTRYDATA, %REDMOB, but that probably won't resolve this for good.

Best regards,

Simon