Same-Band BLE Alert Egress: Getting the Last Word Out
When WiFi gets held down, the node shouts the alert out over Bluetooth instead.
Contested Space · Contested capability
Latent emits a reading. It does not switch cameras, unlock cages, cut power or open a ticket. Your VMS, PoE switch or access controller does that, on your side of the boundary. A Latent blueprint contains no executable code, no remote URLs and no device secrets — by schema, not by policy.
No face, no plate, no MAC, no device identity, no payload. A movement signature is a shape moving through a room, not a person. Nothing stored here resolves to an individual.
BLE is in the same 2.4 GHz band. This survives channel-targeted jamming and deauth. It does not survive broadband jamming — under broadband the mesh goes dark, and dark is itself the alarm.
Across Airspace A jammer already running when you took the baseline is invisible. The baseline must be captured in a verified-quiet window, and a baseline of unknown provenance is worth nothing.
Each node mints its own key over USB, in your hand. Physical possession is the root authority: a device that cannot prove physical presence is refused enrollment outright. A cloud pairing PIN is a weaker ownership claim and is never treated as liveness.
Every reading is attributable to a device id, profile id, hardware id and firmware version recorded at install and verified by mutual HMAC-SHA256 proof over an LFW1 nonce exchange. A node whose proof did not verify is marked untrusted, not merely offline.
Completing an installation is a high-risk action. It requires your explicit browser approval, an approval snapshot that still matches, an idempotency key, and heartbeats less than three minutes old. There is no silent commissioning.
How enrollment worksProperties you can map to your own controls
These are properties, not certifications. Latent does not assert compliance with any framework on your behalf.
The evidence is proven or strong, but this capability still needs a capability-specific ESP32 or Rust runtime adapter.
Published physics or adjacent results support the hypothesis; capability-specific product and site validation are still required.
No browser runtime is assigned to this capability yet.
No capability-specific offline runtime is mapped yet. Keep the feature visible, explain the required edge adapter, and never fabricate a live result.
Intended capability
This describes the intended outcome. Readiness is needs edge adapter, evidence is class B, and a catalog mapping or recording is not proof of this outcome at a real site.
Solution blueprint
This exact kit is one of 191 first-class designs. It includes geometry, objects, nodes, wording, scenarios, installation, limitations, and catalog-bound readiness.
No rendered revision is available yet.
Bundled recording
This is one recorded vertical scenario. It is not separate validation of every capability in the catalog.
The ESP32-S3 time-shares one radio between Wi-Fi and BLE, and BLE's adaptive frequency hopping spreads advertisements across 40 channels spanning the band — so a narrowband or channel-targeted attacker that kills one 20 MHz Wi-Fi channel leaves most advertising channels usable. A compact zone identifier plus a link-health digest fits inside a single extended advertisement payload, which is why the alert needs no association and no handshake.
Link-denial verdict from the jam_detect family -> compact digest encoder (zone id, node id, rate deficit, power direction, sequence counter) -> BLE extended-advertisement egress with hop diversity -> neighbour-node relay and gateway ingest -> deduplication by sequence counter at the host.
This is a capability design path. Components may be shared with other catalog entries; it is not presented as a unique algorithm.
Blocked on the link-stats host import for the trigger side; the egress side is testable today. Own-hardware plan: four nodes plus a gateway, channel-targeted jamming of the Wi-Fi channel while a scripted alert is emitted every 2 s; report alert delivery rate and latency under channel-targeted jamming, then repeat under a broadband emitter to document — not to survive — the total-blackout case.
'Last Word' — the alert that leaves the building while the Wi-Fi channel is being held down, sold to the SOC lead with the honest ceiling stated up front: it beats a channel-targeted attacker and loses to a broadband one, and losing is designed to look like an alarm.
A quiet reading is not an all-clear. If nodes are stale, degraded or jammed, this runtime says so explicitly. It never infers safety from missing data.