Everything you need to know about iPhone 12’s ultra-wideband and HomePod mini

Besides launching the iPhone 12 smartphone lineup, Apple has introduced a number of other products over the course of several special events. The advent of ultra-broadband support in the HomePod mini, as well as the Apple Watch Series 6, has led to further discussion about the technology and its potential use in the future by the company.

Some may still be confused about what ultra-broadband really does, and how it might benefit them in the future. Aside from Apple’s explanation that it could be used for some location tracking, the company hasn’t really done much in how to explain extremely broadband in practice, beyond prioritizing AirDrop.

In this article, we aim to demystify ultra-broadband.

Very broadband, referred to as UWB, is a wireless communications protocol, which operates using radio waves. At its most basic, it can be used to transfer messages between devices, which makes it somewhat similar to Bluetooth or Wi-Fi.

Since it has potential applications for personal area network communications i.e. allowing devices on a person to communicate with each other, there is a lot of intersection with the more established Bluetooth technology. However, the way it works means it can offer more functions that the other two types of communication cannot provide.

The main feature it enables is high-precision location tracking, as devices using UWB will likely be able to determine the distance and even the location of other devices related to themselves within a few inches. This means it has potential uses for device tracking services, such as an improved form of the Find My app.

Apple’s iPhone 11 product page detailing the inclusion of the U1 chip in 2019.

While it has some industrial purposes, including radar and medical imaging systems and even tested it to handle it Send signals On the New York City subway, the primary use of technology for consumers is still likely to be inter-device communications and short-range location tracking.

As an idea, UWB has been around for quite some time. It is only relatively recently that it has ascended to the top spot, mainly due to Apple’s inclusion of the technology in the iPhone 11.

The FiRa FederationWhich includes Samsung, Oppo, Xiaomi, and other companies in its membership, was formed in 2019 to encourage the creation of UWB for cross-platform consumer devices, such as between different smartphone models. Although the group exists, it does not consider Apple a member yet and it is not clear if the Apple app will work with the FiRa release in the future.

Like other radio communication systems, UWB relies on a set of hardware-based transmitters and receivers. While Wi-Fi and Bluetooth use relatively narrow frequency bands to handle communications between devices, UWB does things completely differently.

As the name “ultra wideband” implies, UWB cancels out narrow bands and instead transfers data over a much larger frequency range. While a typical Wi-FI channel width might be 20MHz, 40MHz, or 80MHz, UWB instead uses a bandwidth of 500MHz or more for its transmissions.

UWB is usually able to do this because it operates in a large range that is not normally used for other types of communications, and for which the FCC has allowed the range from 3.1 GHz to 10.6 GHz for unauthorized use. Apple’s U1 chip, which is used for Apple’s ultra-broadband applications, has been scrapped by TechInsights He indicated that it travels at two frequencies: 6.24 GHz and 8.2368 GHz.

U1 chip on iPhone 11 Pro Max [via TechInsights]

An unusual characteristic of UWB is that it is a pulse-based system, one that repeatedly emits signals and then turns off before repetition. While each pulse can consume the full bandwidth assigned to it, the extremely short transmission times of each pulse, combined with the relatively low power nature of the UWB band intended for consumers, makes it unlikely to interfere with other systems in the same bands.

The use of such large bands means that the signal can easily be used to transmit data. Given its ability to transmit more than a billion pulses per second, and using multiple pulses per bit of encrypted data, this could equate to a speed of hundreds of megabits per second under ideal conditions.

These aren’t quite Wi-Fi speed levels. There is still quite a lot for connections outside of large user-driven file transfers.

The lower power levels imposed by the regulator for broadcasting combined with the more fragile nature of higher-band transmissions mean that the utility’s range is not far, usually up to 30 feet, and thus is not ideal for such communications in the first place.

The pulse-based nature lends itself to extremely wide band for location tracking in a number of ways. For starters, by regularly sending a pulse of data, it can enable other neighboring devices to know their presence, or vice versa if they are receiving a pulse from another device.

UWB use and its wide range of frequencies also allow devices to perform time-of-flight (ToF) calculations, that is, how long it takes to obtain a response, which provides a much more useful data point: how far apart the devices are.

Using this wide bandwidth, this system enables practically to overcome multipath propagation, that is, cases where radio waves take multiple paths to reach a destination, such as resonating surfaces. Since some of the frequencies used in the pulse are very likely to reach the intended recipient directly with line-of-sight, calculations can be based on them and not the slower switched signals on other frequencies, resulting in a more accurate calculation.

Apple’s illustration of UWB being used for relative location-based games, in this case Pong multiplayer.

One iPhone sends a packet of data to another iPhone, in a task known as “range.” The second device receives it, and sends a response to the first, which is then received, recording all receiving and sending times.

The first device can then send a third data packet to the second, containing the device ID, the time stamp for sending the first packet, the timestamp of when the first device received its response, and the time the third packet was sent. This is enough data for the second device to determine how far apart the two devices are from each other.

Since the second device has timestamps for receiving and sending packets, similar data points can be sent, which also notifies the first device of the range.

Since it is also possible for UWB radios to determine the angle of the incoming signal, this can also enable them to determine which direction the device is located relative to it. Combine this with distance calculation, general relative positioning can be determined, and with a higher degree of accuracy than other methods.

For example, it is possible to locate a device using Wi-Fi signals within approximately 10 feet, while GPS with GLONASS can reach within 6 feet. Bluetooth can practically reach a distance of about 10 feet for devices using Bluetooth 5.0 or later, but Bluetooth 5.1 offers more directional sensing capabilities that can allow location tracking within a few inches, once the technology becomes more popular.

UWB resolution can mount a device within a foot at worst, but generally within a few inches. Accuracy depends on some factors, such as distance and line of sight between devices.

Although the idea of ​​UWB has been around for some time, it has only become a consumer concern since late 2019, when Apple included the technology in the iPhone 11 range, including the iPhone 11 Pro and iPhone 11 Pro Max. In those models, Apple introduced the U1 chip, which is only used for UWB connections.

At the time, Apple provided a reason to use it for AirDrop, as it could be used to prioritize a list of devices that could share a file with. By pointing iPhone to another iPhone, that device jumped to the top of the sharing list.

HomePod mini UWB is used for proximity features.

Outside of iPhones, only two other devices in the Apple range have the U1 chipset, with the Apple Watch Series 6 and HomePod mini both featuring Ultra Wideband support. However, Apple hasn’t really identified any reason why U1 is in the models. Although HomePod mini enables Handoff on a proximity basis by drawing an iPhone near it, this is also available without UWB on HomePod, but Apple says it is specifically used for the “near device” function on the mini device.

In terms of what to expect from UWB in the future, Apple has been relatively quiet about what is on the horizon, although unlike other elements of its ecosystem, it has not been completely silent.

In June, Apple introduced a “close interactions” developer framework for U1-equipped devices, allowing developers to create applications that take advantage of trend and relative distance data. As part of its documentation, Apple proposed a ride-sharing app that would allow driver and passenger to easily find each other, as well as a water balloon battle from an augmented reality.

Apple is also believed to be considering some non-iPhone uses for UWB as well, with “AirTags” often cited as a prime example.

‘AirTags’ is rumored to be a UWB-backed device tracking tag [image via Jon Prosser/@CConceptCreator]

Believed to be similar in concept to tile track tags, “AirTags” are believed to consist of a small circular dial with Bluetooth and UWB radios. The idea is to attach it to the items you want to track, then use the Find My app to transfer it.

It is also believed that the Find My app not only provides the geolocation of the tag but will also make use of augmented reality to display the near location of the overlaid tag on a live video broadcast from the iPhone camera.

The idea is that the world’s remaining “AirTag” will be duplicated with UWB, which can be picked up by nearby iPhones with U1 chip located in the region. These iPhones will share location data of where they were when they discovered the UWB broadcast, which can be made available to the tag owner via the app.

The presence of the U1 chip in the HomePod mini indicates that some form of smart home functionality may be on the way, and it likely includes HomeKit. For example, Apple can enable a feature where UWB is used by a new HomeKit device to determine which “room” it should be installed in based on the proximity and relative location of other products.

It may also be possible to use iPhone detection in a room to apply generic verbal commands such as “turn on the lights” to apply to that room only, and to automatically turn them on and off as the user transitions between rooms. This localized super scale opens up a world of possibilities for smart home interaction.

Of course, this depends on Apple adding the U1 to more products and possibly enabling other devices to interact with its UWB app. With U1 expanding from iPhones to Apple Watch and HomePod mini, it seems very reasonable for Apple to do so.