UWB positioning (Ultra-Wideband) is a radio technology that makes it possible to locate devices and assets inside buildings with an accuracy on the order of 10–30 cm — where GPS stops working and Bluetooth and Wi-Fi are off by several meters. For companies building real-time telemetry and asset-tracking systems, precise UWB positioning opens up applications that were previously out of reach: from warehouse automation to worker safety and guest services in hospitality.
In short: UWB positioning uses an ultra-wide radio band (≥500 MHz) and measurement of the signal's time of flight to determine a tag's position with 10–30 cm accuracy, forming the core of modern real-time location systems (RTLS) in IoT.
What is UWB positioning?
UWB positioning is a method of determining an object's position based on radio pulses over a very wide band, operating in the 3.1–10.6 GHz range. The IEEE 802.15.4z standard defines the physical layer and the mechanisms for secure distance measurement. Unlike narrowband technologies, UWB does not infer distance indirectly from signal strength, but directly measures the time a pulse takes to travel between devices.
The system consists of two elements: stationary anchors with known coordinates and mobile tags attached to people, carts, or tools. A location server combines measurements from multiple anchors and computes the tag's position in 2D or 3D. It is worth emphasizing that UWB positioning works independently of lighting and does not require a camera's direct line of sight, which distinguishes it from vision-based systems and makes it resistant to dust or the changing conditions of a factory floor.
How does distance measurement work in UWB?
UWB determines distance based on the signal's time of flight, not its power. A pulse lasts only a few nanoseconds, so the circuit precisely distinguishes the direct signal from reflections (multipath) — this is the source of centimeter accuracy.
In practice, two approaches are used:
- TWR (Two-Way Ranging) — the tag and anchor exchange packets, and distance follows from the round-trip time; it does not require clock synchronization.
- TDoA (Time Difference of Arrival) — synchronized anchors measure the difference in the arrival time of a single packet; it scales to thousands of tags at low power draw.
With at least three distance measurements, the server applies trilateration to determine the position. We described similar data-processing principles in the context of WebSocket-based real-time dashboards.
UWB versus BLE, Wi-Fi, and LoRaWAN — when to choose UWB?
UWB wins where precision matters, but each technology has its niche. The comparison below helps match a solution to the application:
- UWB: 10–30 cm accuracy, 30–100 m range, higher anchor cost — for precise localization and secure ranging.
- BLE: 1–5 m accuracy, cheap and ubiquitous — for coarse presence detection (more in our article on Bluetooth Low Energy in IoT).
- Wi-Fi RTT: 1–3 m accuracy, uses existing infrastructure.
- LoRaWAN / NB-IoT: wide-area localization, kilometer-scale ranges, lower precision — for field tracking, which we compared in the piece on networks for asset tracking.
In short: UWB positioning is used indoors when accuracy below half a meter and resistance to reflections are required.
Where is UWB positioning used in industry and hospitality?
UWB positioning is used wherever the accurate position of people and assets in real time matters. Typical deployments include:
- warehouse automation and locating AGV carts with centimeter navigation precision,
- worker safety — exclusion zones, human–machine collision detection,
- tracking tools and assets as part of device fleet management,
- hospitality and premium venues — geolocated guest services and keyless access control.
In industrial IoT (IIoT), UWB integrates with MES systems and cloud platforms, complementing sensor data with a spatial dimension.
How to deploy a UWB-based RTLS system?
Deploying a UWB RTLS system is a hardware-firmware-cloud project that FSS delivers end to end. The order of work usually looks as follows:
- Coverage design — placing anchors so that each point is visible to at least 3–4 anchors.
- Hardware and firmware — selecting UWB chips (e.g., Qorvo DW3000) and designing the PCB and firmware for energy-efficient tags.
- Calibration — measuring antenna delays and offsets, crucial for centimeter accuracy.
- Cloud layer — the location engine, filtering (e.g., a Kalman filter), and an API to upstream systems.
- Integrations — connecting to ERP, MES, or PMS through our system integrations.
Security of distance measurement in UWB
Secure Ranging in the 802.15.4z standard protects distance measurement against relay and distance-spoofing attacks that broke older keyless systems. Cryptographically generated STS (Scrambled Timestamp Sequence) sequences make it impossible for an attacker to forge the time of flight.
This makes UWB attractive for access control and contactless payments, where BLE alone can be vulnerable to relay attacks. Device-layer security is worth combining with authentication based on X.509 certificates on the cloud side.
Frequently asked questions (FAQ)
What accuracy does UWB positioning provide?
UWB positioning achieves 10–30 cm accuracy in typical indoor conditions, and even below 10 cm in a controlled environment. That is an order of magnitude better than BLE or Wi-Fi, which offer from one to several meters. It results from the very wide band (≥500 MHz) and precise time-of-flight measurement.
How does UWB differ from Bluetooth Low Energy in localization?
BLE estimates distance based on signal strength (RSSI), which gives an error on the order of meters and is sensitive to reflections. UWB measures the physical time of flight of a radio pulse, achieving centimeter accuracy. BLE is cheaper and ubiquitous; UWB is chosen where precision and resistance to multipath matter.
How much does deploying a UWB-based RTLS system cost?
The cost depends on the number of anchors and tags. A single anchor is usually 50–150 EUR, and covering 1,000 m² requires 4–8 anchors. On top of that come tags (10–40 EUR each), a location server, and integration. For a device fleet, UWB becomes more cost-effective as scale and the value of the tracked assets grow.
Summary and key takeaways
UWB positioning is today the most accurate widely available indoor localization technology: 10–30 cm, resistance to reflections, and secure distance measurement. It proves its worth in warehouses, IIoT, worker protection, and premium hospitality — wherever coarse radio solutions are insufficient.
FSS designs complete RTLS systems: from chips and firmware, through calibration, to the cloud and integrations. If you are planning to deploy precise localization, explore our services in connected devices and let's talk about an architecture tailored to your facility.