The modem scores each cell for signs of an IMSI catcher, moving it through SAFE → SAFE_NEAR_ALERT → ALERT → ALERT_NEAR_HOSTILE → HOSTILE; past a threshold it bars or deprioritises the cell. On for all networks.

Detection thresholdslikely

GSM settingsGERAN

CUSTOM: 2, 500, 200, 500, 0
ACTIVE_PLMN_LIST: ALL

GERAN: 1, 500, 5, 10, 50, 80, DEFAULT

Field names come from the modem image's strings.

pt.mbn NV 64628: the NS value signalled per LTE band, without and with carrier aggregation, by MCC.