Overview
GPS doesn't work indoors, and Wi-Fi/BLE-based positioning only gets you room-level accuracy at best. Ultra-Wideband (UWB) closes that gap, delivering centimetre-level ranging indoors by measuring the time of flight of very short radio pulses rather than relying on signal strength. Paired with an ESP32 for control and connectivity, UWB modules make precise indoor positioning practical for real products rather than just research demos.
How UWB Ranging Works
Unlike Wi-Fi or BLE positioning, which infer distance from signal strength (a notoriously noisy measurement indoors), UWB measures the actual time it takes a radio pulse to travel between two devices and converts that directly to distance. Because it's a direct time-of-flight measurement rather than an inference, it's far less affected by reflections and multipath interference from walls and furniture — the main reason UWB reaches centimetre accuracy where other wireless positioning methods can't.
Anchors, Tags, and System Design
A typical UWB positioning system has fixed anchor units mounted at known positions around a space, and mobile tags attached to whatever needs tracking. Each tag ranges against multiple anchors, and trilateration from those distances yields a position. Anchor placement geometry matters as much as the UWB hardware itself — poor anchor layout degrades position accuracy regardless of how good the ranging is.
Where UWB Fits
UWB is the right tool when a project genuinely needs precise indoor location — asset tracking in a warehouse, personnel safety zones on a factory floor, or precision proximity detection — rather than just rough presence detection, which cheaper BLE beacons handle fine. The added accuracy comes with more anchors to install and a more involved system design than a simple BLE deployment.
How PAK-EL LAB Can Help
PAK-EL LAB designs ESP32 and UWB-based positioning systems, from anchor and tag hardware through to the firmware and application layer that turns ranging data into usable position information. If you're evaluating indoor positioning for a project, our team can help determine whether UWB is the right fit.
Related service: ESP32 & UWB Development