Design & rationale
Architecture
The decisions behind the fleet, with the reasoning and the evidence that produced them.
ADR — Multi-Master Remote Administration
Adopted · 12 SEP 2026The three-master PKC design: every node carries all master public keys except its own, so no single lost device strands the fleet.
Gateway & MQTT Architecture
Current design · 12 SEP 2026One gateway, one bridge: why uplink can be redundant but downlink must be singular per RF neighbourhood, or the mesh loops.
Hop-Limit Justification
v1 — single 10-minute capture; v2 plannedWhy hop limit 5, argued from a 10-minute RF capture: 100% of distinct nodes were within 4 hops, 95% of traffic within 5.