From 72d19be933c734ba23c0eeac0a649e31fe8af220 Mon Sep 17 00:00:00 2001
From: Eratostenes de Gitjabia <eratostenes@blocaolabs.com>
Date: Sat, 9 May 2026 12:24:16 +0000
Subject: [PATCH] =?UTF-8?q?docs(decisions):=20ADR=200002=20=E2=80=94=20tie?=
 =?UTF-8?q?r=20hierarchy?=
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+# ADR-0002 · Tier hierarchy: Router / Cell / Core / Hub
+
+**Status**: accepted
+**Date**: 2026-05
+
+## Context
+
+The platform is distributed across multiple physical components. Without a clear naming convention, conversations devolved into ambiguous terms ("the box", "the gateway", "the brain"). We needed a vocabulary that:
+
+- Reflects the actual physical/logical separation.
+- Scales from minimal deployments (one site, few cameras) to large fleets.
+- Is brandable and can be used in marketing without sounding generic.
+
+## Decision
+
+Four tiers, named:
+
+| Tier | Name | Hardware | Role |
+|---|---|---|---|
+| 0 | **Blocao Router** | OpenWrt-class device (e.g. GL.iNet GL-MT6000) | Gateway, broker, console host, GitOps reconciler |
+| 1 | **Blocao Cell** | RK3588 SBC (e.g. Banana Pi BPI-W3) | Edge AI inference, recording, forensic API |
+| 2 | **Blocao Core** | Jetson Orin NX or similar | Multi-Cell coordinator, heavier models. **Optional** |
+| 3 | **Blocao Hub** | EU sovereign bare-metal (Hetzner Falkenstein/Helsinki) | Multi-site control plane, fleet management |
+
+**Topology notation**: `R+1` (router + 1 Cell), `R+3+C` (router + 3 Cells + 1 Core), `R+0` (router only, no edge AI yet).
+
+Sites are identified as `BL-<slug>` (e.g. `BL-LAB`, `BL-WAREHOUSE-N`).
+
+## Consequences
+
+**Good**:
+- Each name is short, brandable, and used as-is in product literature.
+- "Router + Cell + Core" follows a biological metaphor (smallest → larger units of integration) that customers grasp quickly.
+- Hub is clearly remote, separating it from on-site components.
+
+**Bad / trade-offs**:
+- "Cell" can be confused with "cellular" (mobile networks). We accept this — context disambiguates, and "blocao cell" + "LTE failover" don't appear together often enough to confuse.
+- Customers occasionally call the Cell "the AI box". We don't correct it in early conversations; the official term sticks once they read docs.
+
+## Alternatives considered
+
+- **Edge / Gateway / Coordinator / Cloud**: too generic, can't be branded.
+- **Node / Hub / Core / Cloud**: "node" is overused, "cloud" we explicitly reject.
+- **Brain / Spine / Eye / Memory** (biological): too cute for industrial buyers.