@Mary Hernandez honestly at 5-10km I'd drop RSSI-based ranging entirely and just let the GNSS module handle position — RSSI is already pretty noisy at short ranges indoors, and at multi-kilometer outdoor distances you're fighting multipath, terrain variation, and atmospheric effects that make the signal-to-distance math basically unreliable. The error margins at that scale would be so wide they'd be useless for tracking equipment locations with any confidence.
The good news is your architecture actually makes more sense the other way around anyway — GNSS gives you 1.5m accuracy at 18Hz, which is genuinely precise for fast-moving or spread-out assets, and the MultiNav Pro+ becomes exactly what you described: a long-range data pipe carrying the GPS coordinates back to your base station or between nodes. That's a cleaner design and you're playing to the strengths of both modules rather than asking RSSI to do something it was never really meant for at these distances.
One thing worth thinking about — if you're worried about GNSS fix loss in certain spots on your site (tree cover, terrain shadows), the BLE link still gives you connectivity to know a module has gone quiet, even if you lose the position data temporarily. That alone is useful for an equipment tracker.
