ModemManager: Signal-/cell information report functionality

Question

I love the simplicity of mmcli but I'm missing some information that for example qmicli (--nas-get* and other commands) provides.

So my question is:

Does ModemManager/mmcli provide any continuous report functionality for the signal strength and other cellular information? I need to collect the data from different modules to find out which one is the most suitable for my gateway.

This question is kind of similar to a former question, but I don't know how to us this special Signal interface.

If this is somehow possible I would also really like to use this for monitoring.

Thank you for your help!

Answer 1

ModemManager has a "Signal interface" which, if supported by the modem implementation, allows to retrieve detailed per-technology signal quality values (e.g. RSRP/RSRQ for LTE).

You can enable the periodic gathering with mmcli --signal-setup=[RATE] (RATE being how often to get those values, in seconds). Once enabled, you can query which are the last retrieved values with mmcli --signal-get.

Another option you may want to use is to just run qmicli -p --nas-get-signal-info periodically yourself in a shell script; just make sure you use the -p option so that your commands can work at the same time as ModemManager is running (by using the intermediate qmi-proxy)