Can I rely on my phone for GPS navigation during off-road excursions in Mongolia?

Yes, utilizing your phone for GPS navigation, even on Mongolia's often unmarked tracks, is feasible with the CoreESIM. Applications like Maps.me or OSMAnd, which support offline map downloads, are highly recommended. While continuous real-time data connectivity may be intermittent in very remote areas, especially between settlements, having an active CoreESIM ensures that when signal is available (e.g., on higher ground or near nomadic camps), your device can update position and access critical information.