Spatial RF.
The cheapest way to spoof a sensor is to attack one band, so sense across all of them. Spatial RF fuses the whole spectrum (mmWave vitals and fall detection, C-band through walls, authenticated UWB ranging, Wi-Fi CSI, BLE, mesh tomography, sub-GHz perimeter) weighted by how hard each band is to forge. Low-trust ambient bands corroborate but can never veto a real event; only a high-trust, keyed-coherent band can. Silence is a fault, not a gap: a dead or jammed node lowers the bar rather than blinding the system. Defeating the fabric means forging a jointly-consistent signature across the entire spectrum at once, which is physically incompatible. The research effort is Sentinel.
sentinel on GitHub ↗A real event corroborates across bands; a spoofed band falls off the manifold; a dead band fails loud. The fabric cycles: monitoring → fall → spoof → fault.
↓ Whitepaper · PDFRead online◆ Living paperTechnical Report TR-2026-13 · Institute for Physical AI @ JBI
You can see through a wall with the radio a room already has. Wavelength sets what detail survives the trip, and no amount of processing recovers what the physics did not deliver, which is a real ceiling and worth knowing exactly. Underneath it, aperture and prior are both engineering and both have room left to run.
One of eight, and only one of them is physics. How we read a frontier →