Real-time location
The most precise
RTLS, by sound.
RTLS — a real-time location system — tells you where people, devices and assets are, the moment they move. Tonebeam is a passive, audio-based RTLS that reaches roughly one centimetre on the phones people already carry: no tags, no app, no signal to lose in a crowd.
What is RTLS?
A real-time location system (RTLS) continuously determines the position of people, devices, or assets within a space — and keeps it current as they move. Traditional RTLS leans on radio: UWB tags, BLE beacons, Wi-Fi round-trip timing. Tonebeam takes a different path. It uses sound, so it resolves position to the centimetre on hardware people already own, and it stays accurate exactly where radio falls apart — dense, reflective, body-packed rooms.
Audio, acoustic, ultrasonic — one idea.
Sound travels roughly a million times slower than radio. That slowness is the superpower: minute differences in when a signal arrives map cleanly to centimetres. Tonebeam emits acoustic signals from simple transmitters — often riding a venue’s existing speakers — and each device solves its own position from what it hears. Because it isn’t radio, crowds and hard reflections barely faze it.
Indoor RTLS, outdoor RTLS — one layer.
Indoor positioning
Where GPS is blocked by the building, Tonebeam resolves floor, aisle, and height to the centimetre — indoor GPS without re-cabling the space.
Indoor navigation
Turn-by-turn wayfinding inside venues: a device solves its own position from the sound around it, then guides people aisle-by-aisle, floor-by-floor.
Outdoor & mixed
One continuous spatial layer from the car park to the back row, so the experience never breaks at the door.
Precision RTLS: centimetres, not metres.
Most systems answer “which zone?”. Tonebeam answers “exactly where”. Roughly one centimetre in three dimensions turns an ordinary phone into a centimetre-accurate location device — precise enough to pixel-map a crowd, route someone to a seat, or track an asset on a shelf.
How audio RTLS compares.
- Tonebeam · Acoustic~1 cm · runs on existing phones · app-free & offline · thrives in dense crowds.
- UWB · Ultra-wideband10–30 cm · needs a UWB chip in every tag/phone · expensive to blanket a venue.
- VPS · Camera / visualSub-metre · needs good light, texture and a clear view · crowds and glare break it.
- Wi-Fi RTT1–2 m · patchy phone support · multipath smears the estimate in busy rooms.
- BLE · Beacons1–5 m · signal-strength guesswork swung by bodies and shelving.
- GPS / GNSS3–10 m · effectively blind indoors where the building blocks the sky.
Where centimetre RTLS pays off.
- Stadiums & arenasWayfinding to the exact seat — and a crowd you can turn into a synchronized light show.
- HospitalsCentimetre asset tracking and indoor navigation without re-cabling, where GPS can’t reach.
- Warehouses & logisticsMetal racking wrecks RF multipath; acoustic positioning is unbothered by reflections.
- Exhibitions & retailVisitors open a link and are placed instantly — no app, no kiosk, no seat to find.
RTLS questions, answered.
What is RTLS?
RTLS stands for Real-Time Location System — technology that continuously pinpoints where people, devices, or assets are inside a defined space. Tonebeam is a passive, audio-based RTLS that reaches roughly 1 cm precision on ordinary smartphones, with no tags and no app.
What is audio (acoustic) RTLS?
Audio RTLS locates devices using sound instead of radio. Because sound travels about a million times slower than radio waves, tiny timing differences map cleanly to centimetres — and unlike radio, sound is barely affected by dense crowds and hard reflections. Tonebeam runs this on the microphone every phone already has.
How accurate is Tonebeam RTLS?
Roughly one centimetre in three dimensions (x, y, z), with device clocks aligned to about ±10 microseconds — far finer than UWB (10–30 cm), Wi-Fi RTT (1–2 m), BLE (1–5 m) or GPS (3–10 m).
Does RTLS work indoors and outdoors?
Tonebeam works in both. Indoors, where GPS is blocked, it delivers centimetre indoor positioning and navigation; outdoors and in mixed venues it provides one continuous spatial layer from the car park to the back row.
Does Tonebeam need an app or special hardware?
No. It runs straight from the browser — or inside your own app — on the phones people already carry. There are no UWB chips, wristbands, or tags to hand out. Transmitters can often ride a venue’s existing audio system.
How does audio RTLS compare to UWB, BLE, and Wi-Fi?
RF approaches degrade in dense, body-packed, metal-rich rooms because radio scatters (multipath). Acoustic positioning keeps solving where RF drowns, is finer than all of them at ~1 cm, and uniquely runs on existing phones with no app.
Can RTLS work in dense crowds?
Yes — that is where Tonebeam is strongest. Tens of thousands of bodies absorb and scatter radio, but sound keeps resolving position cleanly, which is why it suits stadiums, arenas, and packed exhibitions.
Where is Tonebeam based?
Tonebeam is based in London, United Kingdom, and the technology is available worldwide.
More terms in the RTLS & light-show glossary.
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Patent-pending technology