UWB Technology
UWB. Ultra-Wideband. Sounds fancy, right? Spoiler: it's short range, high accuracy, low payload. Not LPWAN. Not Wi-Fi. It’s kind of like radar for gadgets. You don’t use it to stream video – you use it to figure out exactly where your keys are hiding. Fancy? Yeah. Messy? Also yeah. It works – mostly when the firmware's not drunk.
Vendor and URL
This “find-my-stuff” wizardry is pushed by:
Main vendor: NXP, Qorvo, Decawave (RIP, they got bought)
Official docs: https://www.firaconsortium.org
If the link’s dead, check the UWB Alliance. Or the graveyard of Bluetooth replacements.
Technical Public Documentation
Specs are scattered. FIRA tries to standardize. The rest is vendor-specific mumbo jumbo.
Full spec: FIRA Spec
GitHub repo: https://github.com/UWB-Alliance (don’t expect much code, though)
Want full stack docs? Prepare to sign NDAs or reverse-engineer chips.
Overview
UWB sends out very short pulses across a wide frequency range. Think impulse radar, not chatty protocol. It’s all about precision – 10cm-level positioning, fast response, high location confidence. If you want to find something quickly and exactly, this is the tool. If you want to send actual data – look elsewhere.
Architecture
Usually point-to-point or point-to-multipoint. Some setups talk peer-to-peer, some rely on anchors, some just blink and hope. Mesh? Nope. Star? Maybe. Cloud? If you bolt it on. The protocol stack is light – because UWB doesn’t care about talking, it cares about measuring.
Device Roles
Devices act as initiators or responders. Anchors and tags. Anchors sit still and listen. Tags move and scream their existence. Everyone does ToF (Time of Flight) or AoA (Angle of Arrival), and nobody has time for your REST API.
Channelization
Uses 500 MHz-wide channels in the 6–10 GHz range (depends on region). There are 9 channels defined, but good luck finding them all supported on one chip. Interference? Rare. But certification is a nightmare if your country has "feelings" about RF.
Frames
IEEE 802.15.4z defines UWB PHY and MAC layers. Frames are short. Header, payload, CRC – standard stuff. But timing is everything. One missed timestamp and your position estimate is in the next time zone.
Networking
No real networking stack here. It’s more like "ping with purpose." Devices exchange ranging packets, compute distance or angle, and move on. Want TCP/IP over UWB? Good luck. That’s not what this protocol was born to do.
Security
802.15.4z added secure ranging – so bad guys can't spoof distances by replaying frames. AES-based protection, cryptographic challenges, timestamps with signatures. Works if implemented right. Fails if someone cheaped out.
Networking Process
Device powers up. Sends a blink. Anchor hears it. Exchanges timestamps. Math happens. Distance is born. Repeat at high speed. If a packet drops, your phone can't find your wallet. Welcome to UWB life.
Use Cases
Finding stuff. Locating people in factories. Smart access systems. Apple uses it for AirTags and “where’s my car” voodoo. Automotive uses it for secure keyless entry. Industrial players love it for high-precision location indoors. Not great for sending data. Great for knowing exactly where your cat is.