Ultra-Wideband (UWB) — comment ça fonctionne et où il s’insère ?

Ultra-Wideband (UWB) is a low-power, short-pulse radio that measures the precise time a signal takes to travel between two devices, and from that timing calculates the distance — and ultimately the position — to within 10–30 cm.

The defining characteristic is the bandwidth: UWB uses signals over 500 MHz wide, which is what makes the timing precise enough to measure distance directly rather than estimating it from signal strength like BLE or Wi-Fi do.

The relevant standards are IEEE 802.15.4z (high-rate pulse) and the FiRa Consortium's interoperability profiles.

There are two common ranging techniques. Two-Way Ranging (TWR): a tag sends a pulse to a fixed anchor; the anchor sends a response; the round-trip time, minus protocol overhead, gives the distance — at sub-nanosecond timing precision.

Time-Difference-of-Arrival (TDoA): a tag transmits a pulse; multiple synchronised anchors record the exact moment of arrival; the differences in arrival times between anchors triangulate the tag's position.

TDoA scales better for many tags (the tag only transmits, doesn't have to wait for replies), TWR is simpler for small deployments. Most enterprise systems use TDoA with anchor synchronisation in the nanoseconds.

Anywhere you need centimetre-class precision in challenging RF environments: automotive plants tracking parts on metal racking; aerospace MRO tracking tools and FOD;

tactical training in kill-houses where every operator's position matters; sports performance tracking in arenas where GPS doesn't work; collision-avoidance between forklifts and pedestrians where false alarms ruin adoption.

UWB tolerates multipath better than narrowband radios, works through normal building materials, and updates many times per second. If 5-metre Wi-Fi positioning isn't good enough, UWB is the next step up.

UWB vs BLE-AoA: similar use cases at the low-accuracy end (1–2 m), but UWB pulls ahead below 50 cm and in dense multipath.

BLE-AoA usually wins on tag battery life (years) versus UWB (months to a year depending on update rate). UWB vs RAIN RFID: completely different — UWB tracks real-time position, RFID confirms presence at read points.

Most enterprises use both. UWB vs Wi-Fi RTT: Wi-Fi RTT can hit metre-level accuracy on supported devices but is constrained by AP-firmware support; UWB has more mature deployment ecosystem.

UWB vs GNSS: GNSS for outdoors, UWB for indoors — they're complementary, not competitive.

Three pain points are real. Cost per anchor: UWB infrastructure is more expensive than BLE — typically several hundred Euros per anchor, multiplied across a site that may need dense coverage.

Tag battery life: active-RF transmission consumes power; high-update-rate (sports, tactical) tags last weeks to months, lower-rate (asset tracking) tags last a year or two.

Battery management at scale is real operational overhead. Anchor synchronisation: TDoA requires nanosecond synchronisation between anchors, usually via wired backbone or dedicated wireless sync. Site design is non-trivial and needs an RF site survey before commitment.

Trois couches comptent. Silicon: Qorvo (acquired Decawave, the original UWB silicon company) and NXP are the dominant UWB chip suppliers, plus more recently Apple's U1/U2 silicon and Samsung's UWB.

Infrastructure and platform: Ubisense, Sewio, Pozyx, Litum and (BLE-AoA-adjacent for some use cases) Quuppa.

Standards: FiRa Consortium for interoperability, plus IEEE 802.15.4z for the underlying spec. For enterprise procurement, the decision is rarely about silicon — it's about which platform fits your environment, which we evaluate during stage 1 with an RF site survey.

Use cases requiring sub-metre accuracy with real-time update rates: WIP and parts tracking in manufacturing (especially metal-rich); tool control and FOD prevention in aerospace MRO; tactical and force-on-force training;

precision athlete tracking; forklift-pedestrian collision avoidance with tight zone tuning; high-value or moving asset tracking in healthcare, defence, oil-and-gas (with ATEX/IECEx hardware).

We don't recommend UWB for zone-level visibility where BLE would suffice, for outdoor applications where GNSS fits better, or for presence-only use cases where RAIN RFID is cheaper and simpler.