Abstract: In one embodiment, a method comprises: determining, by a network device, a time gap between first and second wireless sessions by a mobile network device in an identified wireless region of a wireless cellular data network, based on first detecting an abnormal closing of the first wireless session based on a first call data record (CDR) generated based on data from a packet gateway (PGW), and second detecting an opening of the second wireless session consecutively following the first wireless session based on a second CDR generated based on data from the PGW; aggregating time gaps for respective first and second wireless sessions; generating a time-based connection quality score for the identified wireless region based on the time gaps; and causing a second mobile network device destined for the identified wireless region to mitigate against poor connection quality in the identified wireless region based on the time-based connection quality score.