Everyone knows about the universal underwear feature between iPad and Mac. But no one knows the magic secret that reveals a lot.

In 2022, Apple launched a feature Universal control (Universal Control), which still provides a level of performance.

Any modern Mac and iPad can be controlled with just one mouse, touchpad and keyboard. At the same time, iPadOS remains untouched, just like macOS.

Using a simple pointer, you can not only efficiently control both circuits, but also drag photo, video, SSSLKI And documents between them.

Universal control works smoothly and seamlessly when the device is connected via wire.

The biggest mystery was that it doesn’t require an additional Wi-Fi network, but it does require both Wi-Fi and Bluetooth to be turned on.

First, let’s see how to enable the function, and below we’ll figure out what kind of magic happens under the hood.

Spoiler: the function has a lot in common with… AirDrop.

What is the difference between Universal Control and Sidecar?

Apple devices have two capabilities that Macs and iPads share in the typical user experience.

Stroller Allows you to use your iPad as a second display for your Mac. There are two modes: additional screen And screen mirroring. The feature appeared in 2019.

Universal control Lets you control multiple Macs and iPads with a single mouse (or touchpad) and keyboard in native versions of macOS and iPadOS.

Using a cable, you can seamlessly transfer files from one device to another, replacing AirDrop. The feature will appear in 2022.

In this post we’ll figure out exactly how it works. Universal controlbecause the feature is more interactive and works incredibly smoothly.

There are four requirements. One unusual thing

There are several important requirements, but the reason is not obvious to everyone.

▪︎ Requires at least one Mac and any other iPad and/or Mac to work, working at a later stage, starting with macOS 12.3 And iPadOS 15.4.

It will not be possible to establish an iPad-iPad connection, since at the moment only a Mac can be the “head” device in the chain.

▪︎ All devices must be logged in under the same iCloud. You can view your account at settings in the first line.

▪︎ The device must not be exposed further than 9 meters from each other, even if they are connected to the same Wi-Fi network.

▪︎Wi-Fi and Bluetooth modules must be included. This is necessary even when there is no Wi-Fi network nearby.

We’ll look into why the requirements are exactly like this immediately after arriving at your destination.

You only need to turn it on once

To make sure your Mac and iPad can see each other to work, follow these settings:

On Mac
Settings > Displays > Additionally > Under Link Mac or iPad included all three toggle switches.

On iPad
Settings > AirPlay and Continuity > Pointer and keyboard [ВКЛ.]

To enable universal control:

1. Log into both devices using your Apple iCloud account.
2. Turn on Wi-Fi and Bluetooth.
3. Drag the touch from your Mac towards your iPad or other Mac. When a stripe appears on one of the edges of the second device, drag the hood all the way.

You can now drag the ball, use familiar macOS trackpad gestures on iPadOS, and drag and drop files (Finder documents and Files apps, photos, videos, text, notes, Safari pages).

Now let’s figure out how Apple taught its devices to interact with each other so smoothly, without lags or delays.

Strange Wi-Fi requirements are necessary thanks to Apple’s unique technologies.

For work Universal control It is necessary that Wi-Fi and Bluetooth modules work on both devices.

This is necessary because:

↔️ Gadgets communicate with each other using their Bluetooth modules.

🔁 Create and continuously transmit data on the tilt of a pair of bends and the dragging of elements through the direct connection of our Wi-Fi modules.

For both steps, Apple has two of its own technologies, thanks to which we do not need to pair devices manually, on our own. universal control runs as smoothly as possible.

To establish connections

To enable devices to communicate with each other, the company uses a special protocol called Bonjour.

By having nearby computers, you can disconnect each other and automatically record an IP address for communication.

Interestingly, this protocol is open, it is integrated into printers, and Google uses Bonjour in the same way so that Android devices can quickly connect to examples, Chromecast gadgets, and so on.

For smooth data transfer

To ensure the device transmits and displays tilt data, text input, and drag-and-drop file transfers without any visible lag and to the full extent, the company uses Apple’s proprietary Wireless Direct Link (AWDL) setup.

This is a Wi-Fi-based wireless protocol that creates a secure peer-to-peer (P2P) connection between Mac and iPad using their Wi-Fi modules.

Over this connection based on Apple Wireless Direct Link continuous flow information about movement, movement and all other user actions necessary for the operation of the universal control is transmitted.

That is devices use direct, high-bandwidth communications without the need to connect to a home or other external network.. Since the Wi-Fi standard allows you to transmit a dense data stream at high speed in an economical mode, the function works smoothly.

🕵🏻‍♂️ AirDrop And AirPlay Powered by the same Apple Wireless Direct Link technology for universal access.

By tweaking the protocol, Apple first created the AirDrop file transfer method and then continued to develop other Handoff capabilities.

This is how a common clipboard and synchronization of processes between different devices appeared in Notes, Safari, etc.

Evolving stream speeds and energy efficiency Wi-Fi modules over time enable the creation of continuous interoperability features such as Universal control and managing iPhone from MacBook iPhone Mirroring.

Thanks to a direct connection via Wi-Fi, we got two cool features of the ecosystem.

Apple Wireless Direct Link not only creates the connection, but also constantly monitors the data flow to adapt the Wi-Fi channel’s bandwidth based on the user’s protocol.

Entering text or transferring data in universal control works so smoothly, and even the office image looks clear when duplicating the screen in Sidecar mode.

Requirements and restrictions related to the need to keep the device at a distance of no more than nine meters from each other. The devices communicate directly with each other, and not through the home network, so if they are far away, they simply will not be able to transfer data at a high enough speed.

As a result, it turns out that Almost any Apple device that allows them to wirelessly connect data to each other operates on an independent base of Wi-Fi connections, distributing the two devices between them.

And if you are wondering how Apple uses this feature in AirDrop, you can find out about it here.