This is the value which we actually suggest in the manpage for the mmcli
operation, so just use the same one.
Scanning for 3GPP networks may really take a long time, so a specific timeout must be given:
$ mmcli -m 0 --3gpp-scan --timeout=300
Found 4 networks:
21404 - Yoigo (umts, available)
21407 - Movistar (umts, current)
21401 - vodafone ES (umts, forbidden)
21403 - Orange (umts, forbidden)
https://bugs.freedesktop.org/show_bug.cgi?id=98235