If you venture into the wonderful world of HomeKit, you may have noticed that some of your devices cannot be controlled or viewed while on the go. This is where HomeKit hubs come into play. A HomeKit hub acts as a relay for your iCloud accessories, allowing you to turn the lights on and off, even when you're away from your home Wi-Fi network. Here's everything you need to know about how everything works.

So what does a HomeKit hub do for HomeKit, anyway?

By default, HomeKit is limited to your personal Wi-Fi network: All handshakes and the Siri command happen within those limits. But a HomeKit hub - in combination with an Apple ID - gives your iPhone, iPad or Mac a safe way to talk to HomeKit devices even when you're away from home.

What devices act as a HomeKit hub?

There are several Apple devices that can act as a hub for configuring HomeKit. Apple TV (third generation or later), HomePod and iPads running iOS 9 or later. The third generation Apple TV is somewhat limited when it comes to HomeKit, because it cannot share access to your accessories outside the home of other users and does not support camera video streams.

How do I connect a HomeKit hub to my accessories?

It's a mix under the hood of Keychain and HomeKit frames. Say you're on LTE: Press the Home button to pick up Siri and issue the "Turn on the lights" command. Without a HomeKit hub, that command doesn't go anywhere - Siri replies with "I can't do this."

With a HomeKit hub on your home Wi-Fi network, however, this command travels through the cellular network back to your hub, where it shakes hands with your Apple ID. "He is the owner of this HomeKit network," the HomeKit hub tells your accessories. "Here is an commandment from them." The accessories execute the order, and the lights in your home are on.

Now, if you do this on the LTE in front of your lights, you will see a slight delay between giving Siri the command and the actually happening command: this is because of that extra handshake that happens between the hubs. HomeKit and accessory; Normally, when you're on Wi-Fi, your orders go straight to the accessory or bridge that controls the accessory.

But, seeing that 90 percent of orders placed outside your Wi-Fi network won't light up right in front of you; they will be to unlock your door, open the thermostat or turn on the lights in the car. By the time you reach your door, the order should have been executed in time to save.

So it's just an extender? Why can't my HomeKit hub be a HomeKit bridge and talk to my non-HomeKit accessories, like my nest?

Just because your Apple TV can talk to HomeKit does not mean it can connect your Hue bulbs and Nest thermostat in that frame. This is due to the different methods of connectivity protocols that some devices use. The current set of HomeKit, Apple TV, HomePod and iPad hubs only supports Bluetooth and Wi-Fi. Devices such as the Philips Hue lighting line use a wireless protocol called Zigbee that requires specific hardware radios. In addition, for the box to be a HomeKit bridge, you should develop secure handshakes and APIs for every third-party accessory - it's not easy to do.

We're not saying it exists not it will be a future HomeKit hub that also works as a HomeKit bridge, but technically it is currently not possible for devices due to different network protocols. So, for now, we are locked with bridges from various manufacturers.

How can I set up a HomeKit hub in my home?

Setting up a HomeKit hub is quite simple. Typically, it involves logging into the same iCloud account that your HomeKit is installed with and switching to the HomeKit hub option. For detailed steps on this process, see our guide below.

How to Make an Apple TV, iPad or HomePod a Home Hub

Other questions?

Anything else about HomeKit and HomeKit hubs that you're confused about? Tell us in the comments, we will be happy to answer any questions you may have.