Several years ago, a street medic described a system like this and wanted to know if it could be built.
https://hackaday.com/2022/09/08/the-tak-ecosystem-military-coordination-goes-open-source/
Back then there was just no way to make it happen. Hardware was too expensive. We couldn't really ever get it cheap enough, per medic, to deploy. Best I could put together was a bunch of burner phones.
But now it's starting to really make sense. LoRa is cheap, and possibly cheaper in bulk. And it wouldn't be necessary to build everything since ATAK-CIV exists and has several open source implementations. It can even tie in to drones (which are illegal to bring to protests in at least a few states).
This has a lot of potential applications for street medic coordination, protest marshal coordination, and for airsoft teams...