[krisoft]

> Third, it can't navigate a path without connecting to the satellite (seemingly for traffic data, but possibly it isn't even calculating the path locally).

I’m confused by what you are saying here. In-car navigation use satelites to know where the car is. If it can’t path plan without satelite connection then that is most likely because it is waiting for a localisation fix.

Trafic information could be coming through satelite broadcast but I doubt that it does.

There is no way that a navigation tool would receive path planning through satelite. Two way communication is much more complicated than one-way reception, and there is no way it would be financially worth doing that.

[pandaman]

Sirius sells traffic info add-on, which is broadcast from the satellite. It is not as detailed as the data-linked apps in cars/phones and is only available for the few big metros but can get the traffic info on an older car's nav system.

[cgriswald]

See my response to the sibling poster: https://news.ycombinator.com/item?id=31587520