UWB vs Bluetooth: RSSI, AoA and Channel Sounding compared

UWB and Bluetooth can both locate devices, but they measure different things: UWB times the travel of very short pulses across a channel about 500 MHz wide, while Bluetooth estimates position from signal strength, from the angle a signal arrives at, or, since Bluetooth 6.0, from phase measurements called Channel Sounding.

For a manager the short answer is this: Bluetooth is cheaper and fine when knowing the room is enough; UWB is the choice when the distance between moving people, vehicles and objects matters to within a metre. The rest of this guide explains why, and where the new Bluetooth Channel Sounding fits.

What are the three ways Bluetooth can locate a device?

Signal strength (RSSI)

A tag or phone broadcasts short advertising packets, and receivers estimate distance from how strong each packet arrives. It is cheap and uses very little power, but signal strength changes with bodies, doors, shelves and the angle of the tag, so results are typically accurate to a room or a few metres. Fingerprinting (comparing readings with a pre-recorded map) helps, but the map has to be redone when the layout changes.

Direction finding: angle of arrival and angle of departure

Bluetooth 5.1 (2019) added direction finding. With angle of arrival (AoA), a tag transmits a special tone and a locator with an array of antennas measures the phase difference between them to work out the direction. With angle of departure (AoD) the array is on the transmitter and a phone works out the angle. Directions from two or more locators give a position. Vendors quote 10 cm to 1 m; accuracy falls with distance and suffers when reflections arrive from other directions.

Channel Sounding

Channel Sounding (Bluetooth Core 6.0, September 2024) measures the distance between two devices. It combines phase-based ranging, comparing phases across many channels in the 2.4 GHz band, with round-trip time as a cross-check and protection against relay attacks. The Bluetooth SIG reports about ±20 cm in early implementations and accurate measurements up to 150 m at maximum power. Core 6.2 and 6.3 (May 2026) refined security and efficiency. Independent tests in 2026 still show that device orientation has a substantial effect on accuracy.

How is UWB ranging different?

UWB sends pulses about 2 nanoseconds long and timestamps when they arrive. Indoors, every signal arrives several times: once directly and again via reflections. Because the pulses are so short, the direct path and a reflection that travelled even a metre further show up as separate peaks, and the receiver uses the first one. A narrowband Bluetooth signal smears these copies together, which is why its strength and phase readings wander.

How do accuracy, cost and battery compare?

Which works better in metal-rich sites and next to Wi-Fi?

Factories and warehouses are full of steel racks, machines and vehicles that reflect radio. Methods that rely on signal strength or phase are hit hardest, because reflections change both. UWB’s first-path timing copes better, although no radio passes through solid metal: base stations still need to be placed so that each tag sees several of them.

Both technologies share spectrum with Wi-Fi. Bluetooth lives in the crowded 2.4 GHz band and hops between channels to avoid interference. UWB channel 5 overlaps the 6 GHz band used by Wi-Fi 6E and 7; laboratory tests have measured heavy UWB packet loss and worse ranging precision next to busy 6 GHz Wi-Fi. Channel 9 lies above that band. On channel 5, a site survey and Wi-Fi channel planning are part of a good installation.

What about phones?

Every phone has Bluetooth, so signal-strength positioning works with apps on any phone. UWB has been in most iPhone models since the iPhone 11 (2019) and in selected Samsung Galaxy and Google Pixel models. Channel Sounding reached its first phone with the Google Pixel 10 in 2025.

Android 16 introduced a single Ranging module that covers UWB, Bluetooth Channel Sounding, Wi-Fi round-trip time and Bluetooth signal strength, so apps can use whichever the phone supports. For industrial sites, dedicated tags remain the norm: they are cheaper than phones, last for years, and can be worn by anyone.

When is Bluetooth enough, and when do you need UWB?

Bluetooth is usually enough when:

• knowing the room, ward or zone is sufficient, for example finding equipment in a hospital;
• you want to reach visitors’ own phones for wayfinding;
• you need very large numbers of very cheap tags and update them rarely.

UWB is usually needed when:

• the distance between two moving things drives a decision, such as warning a pedestrian near a forklift;
• you need to know which workstation, bay or lane something is in, to well under a metre;
• you track fast movement at high update rates, as in sports;
• the site is full of metal and the result must be reliable.

Use both when phones or tags need Bluetooth for setup, configuration or a companion app, and UWB for the distance measurement. Digital car keys and the Aliro access-control standard work this way.

Where to go next

For the wider picture, including Wi-Fi, RFID, GPS and cameras, read indoor positioning technologies compared. To understand how UWB turns timing into position, continue with what is UWB and TWR vs TDoA vs AoA. For what to expect on site, see UWB accuracy and range.

Frequently asked questions

Sources and further reading

• Bluetooth SIG: Bluetooth Channel Sounding
• Bluetooth SIG: Bluetooth direction finding
• Bluetooth SIG: Just released, Bluetooth Core 6.3 (May 2026)
• Android Developers: Range between devices (Ranging module)
• Bapat and Nagaraj: IMU-aided correction of orientation-induced ranging error in Bluetooth Channel Sounding (arXiv, 2026)
• Brunner et al.: Understanding and mitigating the impact of Wi-Fi 6E interference on UWB (IPSN 2022)

Published 22 October 2026. Last reviewed 22 October 2026 by the Noccela engineering team.