Subscriber-aware distribution trees — one stream, many watchers
Ten operators watching one 6 Mbit/s drone feed today means the shared multi-hop trunk carries it ten times — and inner multicast doesn’t help: for flat-mesh correctness a packet to 224.0.0.0/4 is replicated at the source, once per peer. The research direction: for declared groups, compute a distribution tree from data every node already holds — the LSDB’s source-rooted SPF plus subscriptions carried in the same flood that carries positions — and fork copies only where subscriber paths diverge, so every common segment carries the stream once. Atlas is unusually well placed: the static-multipath path already has intermediates forking stamped copies with destination-only dedup, and hop-by-hop re-encryption means branch replication needs no group-key machinery. Scope stated plainly: unreliable-with-FEC delivery (video-shaped — no ACK trees), opt-in per group, re-rooted on topology change like any route. Until then, the answer is a video reflector on the junction node — one session across the trunk, fan-out where bandwidth is cheap.