What is UWB? Everything you need to know about Ultra-Wideband

It sometimes feels that, as consumer technology continues to evolve, we’re bombarded with a never-ending stream of new technologies and acronyms, many of which disappear as soon as they’ve been coined. One that is here to stay, however, is ultra-wideband, or UWB. 

As we at Pointr focus on indoor location and positioning technology, we’re regularly asked about what UWB is and its capabilities. In this post, we’ll go into detail about the fundamentals of UWB. If you’re looking for a detailed comparison of UWB’s capabilities for indoor positioning versus Bluetooth, you’re in luck - we have a post on UWB positioning here.

What is ultra wideband (UWB)?

Ultra-wideband is a low-energy radio technology that utilizes radio waves to beam basic information from one compatible device to another - for example, a UWB-enabled smartphone and a UWB beacon.

Because it utilizes a wide bandwidth, UWB avoids the potential issue of interfering with other radio signals and devices, which is particularly important on devices such as smartphones, where existing technology like carrier waves could otherwise be impacted.

What is UWB’s range and signal strength?

UWB has an effective range of up to 200 meters, provided there are no obstacles or impediments for the waves to pass through. Practically speaking, UWB is most effective when transmitting across distances of under 50 meters. This is sufficient for the majority of indoor positioning and navigation systems, given that they typically utilize multiple beacons at fixed points within a building in order to measure a user’s position effectively.

As a radio wave-based technology, UWB is also capable of passing through frequently occurring obstacles within an indoor location, such as walls. Naturally, passing through multiple obstacles will eventually diminish the signal strength, but as previously mentioned, an effective IPIN system will utilize multiple beacons, meaning there will be a limit on the number of beacons being asked to transmit through several obstructions.

As with any technology that is designed to communicate information regularly between devices, the range and strength of signal of that technology is of critical importance, and UWB, with its emphasis on communicating between one static and one mobile device, is no exception. If UWB’s range and signal strength are impacted significantly within a few meters of movement, then its efficacy as an indoor positioning technology would be enormously impacted.

What are the differences between UWB and Bluetooth?

For practical purposes, the technical differences between UWB and Bluetooth have little impact on the end-user. There are some small differences between the two technologies that do have some practical implications, particularly when it comes to setting up deciding whether to useUWB or Bluetooth for an indoor positioning or localization system.

Out of the box, UWB can provide a greater degree of accuracy compared to Bluetooth. You may think this would make it an automatic choice for indoor positioning technology, but while the accuracy of the technology is a good starting point, that’s simply one piece of the puzzle that still needs to factor in features such as orientation, indoor-to-outdoor transitions, smart navigation rerouting and more. Pointr have earned our reputation with our ability to take the basic signals sent by beacon hardware and, using complex algorithms, transforming them into market-leading positional accuracy, capable of highly accurate indoor navigation.

What’s more, Bluetooth technology is constantly improving, with the current Bluetooth 5.1 version making great strides in how precisely it can pinpoint a location.

UWB also has a slightly greater optimal range compared to Bluetooth, however, this is largely redundant when discussing an indoor positioning system; most deployments will feature multiple beacons well within the range that both technologies are capable of operating within. As with accuracy, Bluetooth is continuing to improve in this area with new versions.

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The other major factor to take into account when comparing UWB and Bluetooth for practical purposes is cost. Currently, UWB chips are more costly than Bluetooth equivalents. A UWB-enabled beacon is typically around 50 - 100% more expensive than a Bluetooth device. In isolation, for one beacon, this difference in price point may not seem enormous, but it can add up to a substantial amount when applied to an indoor location deployment comprising hundreds or even thousands of beacons. And this is only looking at one side of the indoor positioning coin. Currently, with UWB technology still in its infancy, it’s far more likely that an effective indoor positioning solution based upon ultra wideband would require hardware investment in not only the beacons to send the signal but the devices (i.e. smartphones or tags) that receive the signals too.

Technology Accuracy Range Suitable for
Wi-Fi < 15 m < 150 m in large venue/ area
BLE 4.0 < 8 m < 75 m in large venue/ area
BLE 5.1

< 1-3 m

(with Pointr Deep Location®)

< 75 m in large venue/ area
UWB < 30 m < 150 m at a specific spot

Source: TechPP

How common is UWB?

Though UWB has seen rapid adoption in recent years, it still lags behind other competing indoor localization technologies such as Bluetooth considerably. In terms of popular consumer devices, UWB can be found in the iPhone 11 and 12 series of smartphones (and other iPhone-related products such as the series 6 Apple Watch), as well as some selected flagship devices from Samsung. 

However, the fact is that UWB remains far from ubiquitous. Where it is present in twinned devices - such as a keycard for a car and the car itself, or a recent iPhone and an Apple AirTag - it operates exactly as intended. However, to use it reliably for indoor positioning purposes, the technology needs to be present in the overwhelming majority of modern smartphones in a way that Bluetooth is. Until this is the case, UWB indoor positioning systems will rely on additional hardware such as tracker tags, or the ubiquity of certain devices (i.e. an office building where everyone present is issued with a standard company smartphone that is a UWB-enabled model, something which may well prove immensely costly).

What is UWB used for?

Due to its lack of ubiquity across many consumer devices compared to competing wireless technologies such as Bluetooth, UWB is generally used in situations where both the emitting and receiving devices are sold together or only compatible with other UWB-enabled devices, such as:

  • Wireless entry systems for smart devices (including homes) and cars, where the 'key' and the 'lock' are both powered by UWB
  • Asset tracking systems in closed environments, such as factories or warehouses. In this case, staff may be given a specialized UWB device which can then locate specific tags
  • Apple have implemented UWB in their personal locator products AirTags, and have supported UWB in all iPhone models since AirTags were launched