The project (mostly) assumes one device per person. Each user carries a tBeam (or one of the other available boards) and Bluetooth connects it to an android phone. The devices mesh with each other, and the phone is used as the interface, with a map view and a messaging view.

Meshtastic automatically sends each nodes location (at a fairly low default update rate, but you can configure that).

There’s a “repeater node” functionality, so a node at base camp or on the highest local terrain can improve the connect ability of the mesh. There’s also a group of people on the forum experimenting with solar power solutions for these nodes, so there’s a fair bit of reported experimental data on solar panel size vs battery capacity vs device runtime (which is all trickier that almost everybody assumes before they’ve tried to do that in real life. “Specs” for solar panels, battery charging controllers, batteries, and even Meshtastic device power consumptions all have way way bigger error bars that most people expects...)