Second Generation Ultra Wideband (UWB) from Apple on iPhone 15

As many of you are aware, Apple recently launched the new iPhone 15 with an upgraded spatial computing Ultra Wideband (UWB) chip.

We wanted to unpack this new chip for the Estimote developer community. This way, you’ll be fully informed on what’s possible now and what to expect in the future.

First-generation UWB chip (U1)
Starting with the iPhone 11, every iPhone has featured the Ultra Wideband chip. Think of it as another radio, similar to Bluetooth or WiFi, that calculates the time-of-flight. When two iPhones are close to each other, they can communicate, and the U1 chip computes the radio travel time. This time is multiplied by the speed of light to estimate the distance between the two iPhones with nearly inch-level precision.

This principle also applies to the interaction between the iPhone and the AirTag. The UWB chip is incredibly compact and energy-efficient and can be added to pretty much any object.

Every iPhone since the iPhone 11 has been equipped also with three UWB antennas. With these, the U1 chip can determine the so-called angle-of-arrival. UWB signals coming from the left hit the left antenna first, followed by the middle and right antennas. By calculating these arrival times, the UWB chip can determine direction/orientation.

In essence, every iPhone can visualize an “invisible vector” pointing to nearby iPhones or objects with attached UWB tags creating unique spatial awareness.

Second-gen UWB chip
Apple’s new iPhone features the second-generation chip (U2). Reports indicate a switch in the silicon manufacturing process from 16nm to 7nm, which should result in lower power consumption and improved range and performance.

Apple showcased a new friend-finding feature using the Find My app between two iPhone 15 during their keynote. In crowded spaces, two iPhones can use UWB ranging to precisely determine distance and orientation. UWB, with its wide spectrum (5-9 GHz), is less affected by the human body and can even penetrate walls.

There is an API called Nearby Interaction API where you can build apps and range to other iPhones or other UWB-enabled devices for example our Estimote UWB Beacons.

Apple has also incorporated the UWB chip into other products like the Apple Watch, HomePods, AirPods, and potentially laptops.

The reason for making the chip more energy-efficient is Apple’s preparation for an array of new applications. One such feature might be “Downlink TDoA”, which stands for Time Difference of Arrival. Imagine a scenario where the phone constantly picks up UWB signals from various directions, like from beacons in a tunnel where GPS isn’t functional. The UWB chip would constantly enhance spatial awareness by passively capturing these signals. It’s a very privacy-centric RTLS (real-time location system) approach since all processing is done on the phone without the beacons collecting any data.

There are more potential UWB applications on the horizon, including radar, contactless health monitoring, and payments. Apple is also a member of a standardization body named FiRa that envisions many spatial and contextual use-cases.

Now you’re in the loop! If you have any questions, drop them in the reply to this post.

Similar content with few more examples we also just published on our Blog: Why Apple's 2nd Gen UWB Chip is Exciting? | Reality matters

thanks for the update does it affect any of your existing beacons in terms of the difference between U1 and U2?

I haven’t been able to touch one of those iPhone 15s yet so I assume that we’re back to the 11th through 13 behavior for distance and navigation rather than the poor behavior on 14.

iphone 15 behaves like iphone 14 ,. not prior 13-11…