What is ultra-wideband? The latest wireless smartphone tech explained

Jan. 27, 2021 09:30AM EST

The smartphone industry, filled with splashy launch events and features described as groundbreaking and magical, has taken a detour when it comes to touting ultra-wideband technology.

The iPhone 11 of September 2019 was the first smartphone to feature the technology, inside Apple's new U1 chip. Ultra-wideband also appears on the iPhone 12 family and Samsung Galaxy Note 20, and most recently appears in the new Samsung Galaxy S21 Plus and S21 Ultra.

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But, for now at least, you would be forgiven for not knowing what ultra-wideband is, why it may be helpful, and even if your phone (or any other device you own) has it or not. That may change this year, in 2021, as we start to see practical uses for a technology that is vaguely related to Wi-Fi and Bluetooth, but began life in the military 30 years ago as a form of radar.

What is ultra-wideband?

At its simplest, ultra-wideband — or UWB —is a radio technology that consumes very little energy and is used for short-range communication. It operates at a very high bandwidth, hence the name, and covers a large portion of the radio spectrum.

UWB is a form of pulse radio, where data is sent out in rapid pulses (up to one billion per second) across a broad radio spectrum ranging from 3.1 to 10.6GHz. Each pulse is in the region of 500MHz wide, making it far larger than the five to 20MHz range of 4G and the 20 to 80MHz of Wi-Fi.

With these characteristics, data can be sent using UWB very quickly and without losing accuracy as it travels between devices. UWB is also less susceptible to interference than other wireless technologies like Bluetooth and Wi-Fi.

The speed of data transmitted by UWB can be as high as 675Mbps, which far exceeds the 2.1Mbps of Bluetooth, but is some way behind Wi-Fi's 2Gbps potential.

The Samsung Galaxy S21 Pus and S21 Ultra have UWB Samsung

UWB technology had been applied to a broad range of applications before appearing on smartphones in 2019. It was used as a part of radar technology by the U.S. military in the 1990s, where experiments were undertaken to prove whether UWB could be used to estimate the velocity of moving targets.

UWB can also be used to monitor a person's heart and respiration rate, as well as analyzing their gait and serving as a form of fall detection. It was also tested on the signaling system of the New York City subway system on the L line and also the 7 line during 2019 where it was described as a "game changer" in helping reduce delays.

The NFL also uses UWB sensors to plot the location and movement of football players and the ball during a game.

While varied, these applications all have something in common – they rely on UWB for accurately determining the location and movement of a target. This is key to why Apple, Samsung and doubtless others want to bring UWB into the consumer technology space.

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Why UWB is being fitted to smartphones

Apple kicked off the UWB trend for smartphones with the iPhone 11 in 2019, and more recently the company added its UWB-enabled U1 chip to the iPhone 12 family and HomePod Mini smart speaker.

With the iOS 14.4 update rolled out on January 26, the first UWB feature was enabled to support the Handover feature for audio between the iPhone 11 and 12 and the HomePod Mini. In this application, the UWB-equipped U1 chips of the iPhone and HomePod Mini can spot each other, then share very accurate locational information, including the distance between them and their relative position.

For Apple users, this means holding an iPhone playing music close to a HomePod Mini will trigger the Handover feature. The iPhone begins to pulse using its haptic engine, with the pulses quickening as it gets closer to the smart speaker. An interface then appears, where the user can opt to switch music playback (or any current audio, like a phone call) from the iPhone to the HomePod Mini.

Apple HomePod Mini and the iPhone 12 Apple

Bluetooth could do this too, but that technology lacks the locational precision of UWB. Also key here is how UWB technology can be used to accurately calculate time-of-flight, further adding to its accuracy credentials.

Beyond the convenient handover of music, UWB technology is expected to be used by possession-tracking devices. Tile is reportedly working on a new version of its Bluetooth tracker that uses UWB for more precise tracking, and Apple is expected to announce a rival this year called AirTag, also using UWB. When it comes to finding a lost set of keys in a field, UWB's extra accuracy compared to Bluetooth could prove invaluable.

Samsung also entered the tracker market this year with its SmartTags. The first version uses Bluetooth like Tile, but Samsung says another model due later in 2021 will have UWB for greater accuracy (albeit only with the compatible Note 20 and S21 handsets for now).

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UWB uses beyond the smartphone

As well as greater accuracy, UWB is a more secure means of data transfer than Bluetooth and NFC, making it a good option for the increasing trend of replacing car key fobs with smartphones. Some car manufacturers already allow a smartphone with Bluetooth to be used instead of a key, but it is likely that they will switch to UWB once the technology has rolled out to more handsets and proved itself as the superior, safer and more precise option.

Looking at the list of members of the UWB Alliance gives further clues as to where the technology could appear in the future. Members include iRobot, makers of the Roomba robotic vacuum, carmaker Hyundai and smartphone firm Oppo.

Members of another UWB industry group, the FiRa Consortium, include Bosch, Qualcomm, Samsung, Cisco, Sony, Facebook, Tile and Hyundai.

Tile is expected to add UWB technology to its trackers GearBrain

UWB and the smart home

We don't know yet what the future will hold for UWB use in the smart home, beyond Apple's tentative steps with the HomePod Mini. But we see real potential here, because when a device like a smart speaker or display knows the precise location of each member of the household (via their smartphone or a wearable device), it can reliably act in a personalized manner.

If a speaker or display knows you are alone in the room, it could share your personal calendar and find the right contact when you ask it to make a call. But if others are also in the room, it could hold back on the calendar events, and ask to check exactly which contact you want to call.

A television or media streamer could bring up your Netflix profile if it knows you are the only person in the room, or even if you are the person holding the controller, assuming it too has UWB technology.

UWB could also help with quickly opening the right smartphone app on your phone. Say you want to interact with a robotic vacuum; you could hold your phone near it and UWB would recognize the robot nearby, then open the app used to configure its cleaning schedule.

The rolling out of ultra-wideband has been uncharacteristically slow for a technology industry endlessly champing at the bit for the Next Big Thing. But that could be a good move, where giants like Apple and Samsung, together with smaller firms like Tile, take a thoughtful, practical approach to UWB, instead of orchestrating a glitzy launch full of promise, before letting it fall by the wayside.

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