I have questions about Matter and the devices and how they integrate with each other and Hubitat and the list goes on.
Background, I started using Smartthings 7 years ago and have a lot of Zigbee and Zwave devices. Upgraded to HE a couple of years later and now use a C7 hub. I have some Alexa routines setup for voice control and within the last year I have integrated Apple Home (Apple TV and 3 Homepde mini's) to my Smart Home environment. Mostly for the Unifi camera integration and the Apple Home app. I really like the Apple UI. I have noticed on my network that there is now this "openthread.thread.home.arpa" which I guess has something to to with the Apple Home. I like to keep all my automations on Hubitat.
Now my questions. Lets say I want a Matter device, how do I connect it to my system? Do I use Apple, HE, the app that comes from the device manufacturer?
How do I automate the device? Can I set up my automations with HE?
Do I use Matter over thread, matter over wifi, matter over God knows what? I don't know.
Is there a smart home primer somewhere that explains all this? Am I over thinking all this?
Zigbee and Zwave were so easy to use, why can't I use their mesh for a matter device? All those devices work great. Or maybe I should forget Matter altogether. Helpful comments are appreciated.
As you can see all this is very confusing to me, but it didn't use to be confusing.
You will need to "commission" the Matter device with an existing Matter controller, which in your case could be Apple Home. Sometimes, manufacturer apps let you set up the device and also provide a way to connect it to a Matter controller, but that's usually nothing you can't do directly with a Matter controller if the device is Matter-compatible. Then you can skip the other app entirely (though sometimes they have easy ways to do other things you might want, like firmware updates).
Using the other controller, you can then put the device in "pairing mode" to add it to another system, like Hubitat. This is a notable difference from Zigbee and Z-Wave if you are familiar with those protocols. Matter allows pairing a device with more than one system at the same time.
Once added to Hubitat, you can certainly automate it using Hubitat just like any other device.
That's up to you -- and what devices you can find. You don't need to pick just one. For Wi-Fi, you'd need a home Wi-Fi network, which you probably have; for Thread, you'll need a Thread Border Router, which you might already have as an Apple user if you have a HomePod Mini or 2nd gen HomePod or certain Apple TVs. You don't have to pick just one.
In short, they are separate protocols. Expanding on this a bit, Matter itself doesn't have a "mesh" because it's just the application layer. It still needs a network layer, which is normally either Thread or Wi-Fi. That's what helps it reach your hub in the first place (and in the case of Thread, via a Thread Border Router--which bridges Thread traffic to your LAN and ultimately your hub).
Thread does have a mesh. But like Zigbee and Z-Wave, they are different protocols and not compatible at this level. (Thread actually will use your LAN, possibly including Wi-Fi, to extend its range if you have Thread devices not within wireless range of each other but within the range of other Thread Border Routers, so it's almost what you're asking for--but it does this all for you under the hood without you needing to worry about it; in many ways, I think of Thread as a smarter version of the lower layers of Zigbee--and Matter as the upper layers.)
I suspect this doc may answer similar questions you have:
Certainly not exhaustive, but this is a very good starting point for Matter and Hubitat:
How to use Matter on Hubitat Elevation | Hubitat Documentation
I myself am not using any Matter or Thread yet since I think they're both still too immature. That's not a slam on either; I'm just in no hurry to wade into any of that stuff at this stage.
If you search the community here, there are some excellent posts that discuss Thread and Matter.
ETA - Robert beat me to it 
So from what I understand so far, in Hubitat our Zigbee and Zwave devices integrated with the Homekit app so Apple home could operate our Hubitat devices. Now with Matter, Apple home Matter devices are integrated with Hubitat so we can operate our Apple connected devices. Seems backwards to me. Am I getting this right?
Hubitat's built-in HomeKit integration does allow most Hubitat devices (Zigbee, Z-Wave, LAN, Virtual, etc...) to be exposed to Apple Home via the HomeKit protocol.
Matter is a much more complicated platform, and it does take some time to get one's head around it.
Apple Home is a Matter Controller, which is also capable of Matter Commissioning. In order to bring any Matter devices onboard, they must be Commissioned. At this time, Hubitat is not capable of Commissioning a Matter device. Thus, Hubitat is relying on other platforms like Apple Home, Google Home, and Amazon Alexa, to perform this initial step. Once a Matter device has been commissioned on one of those platforms, that device can then be shared with other Matter Controller devices, like Hubitat.
One thing to be aware of is that ONLY Matter devices on Apple Home, Google Home, and Amazon Alexa can be shared with other Matter Controller devices. For example, any devices you have in Apple Home that are paired using the HomeKit protocol, cannot be shared with any other Matter Controllers. This is because Matter Devices, when shared with other Matter Controllers, communicate directly with those other Matter Controllers.
Matter Bridges are a special class of Matter devices that can share non-Matter devices with other Matter Controllers as if they were native Matter devices. The Philips Hue Hub and Aqara Hub are both Matter Bridges, that can expose their private Zigbee mesh network devices to Matter Controllers that support Matter Bridge-based devices. Hubitat is currently adding support for Matter Bridges, but it is not quite ready, yet.
Ok, scenario. Lets say that I just setup a Matter over thread device with Apple. Then I setup the same device in Hubitat. When I go to control the device with a HE Automation or just from the device page, will HE be controlling this device directly or will it be controlled by Apple directly? I hope this makes sense.
HE will control the Matter device directly. The Apple hub is needed only during the initial commissioning process.
Later on, the Matter device will send status updates to both the HE and Apple Home controllers at the same time. The Matter device can be controlled from both HE and Apple at the same time.
This allows configuring some 'High Availability' automation scenarios - for example, a Matter bulb can be controlled by a Matter motion sensor simultaneously from both Hubitat RM and Apple Home automation.
If one of the hubs (HE or Apple) is powered off, the other hub will continue controlling the lighting. This is tested and confirmed.
Matter over Thread devices are little more complicated than other Matter devices. Thread uses the same 2.GHz radio as Zigbee. However, instead of using the Zigbee wireless mesh protocol, Matter over Thread devices use the IPv6 Matter over Thread protocol. In order for these Thread devices to communicate with matter Controller devices, there must be at least one Thread Border Router (TBR) device on you home network. The device that is acting as the TBR is involved in all communications between Matter Controllers and the Matter over Thread devices. Thus, Hubitat would have to rely on the TBR (e.g. an Apple HomePod Mini or an AppleTV 4K w/Ethernet) to communicate with any Matter over Thread devices.
Once again, it should be noted that Apple Home does support some non-Matter devices that use a proprietary HomeKit over Thread protocol. These HomeKit over Thread devices are not Matter devices, and thus they cannot be shared with Matter Controllers.
Where this gets even more 'fun' is that you can have multiple TBR devices on your home network. Currently, if all of these devices are from Apple, they will work together on the same Thread Mesh network. Same goes for all Google TBR devices. Or all Amazon TBR devices. However, TBR devices from multiple manufacturers currently do not play well together, as each creates its own Thread mesh network.
Also, please know that Thread 2.4GHz channels are the same as the Zigbee 2.4GHz channels. Thus, the 2.4GHz frequency spectrum is getting even more crowded, and most TBRs do not allow the user to select the channel that they run on.
I am getting more confused. Don't all the Matter devices have to be Matter over something? Whether it is Thread or Wifi or is there something else? I thought that Matter was supposed to solve the compatibility concerns with new devices. One device for any system. But it seems that this is not the case.
Seems like they are not as compatible as we thought they would be.
Yes, because:
It seems you actually do understand this point, unless the above was a hesitant question and not a statement, but either way, you are exactly correct. I'm not sure if there's another question, or maybe it just needs re-iteration that Thread and (obviously) Wi-Fi both pre-date Matter and have other uses outside of Matter. So:
- Thread or Wi-Fi alone does not mean Matter; and
- Matter itself does not define any network/physical layer, so there needs to be something underneath; this is normally Thread or Wi-Fi (while it would be great to only have one option, Wi-Fi is too power-hungry for things like battery-powered sensors to be practical, while the higher bandwidth of Wi-Fi can be useful for chattier devices; some devices could work well with either, but Thread can't be reserved only for battery devices since you need mains-powered devices/routers to build a good mesh)
Thread makes things a bit more complicated since you need a Thread Border Router (TBR) somewhere to make it work (at least in any practical way). In an alternate universe, maybe Hubitat would have a Thread radio built-in so it can be as seamless as Zigbee and Z-Wave are right now. However, there are maybe even some advantages to not being built-in (e.g., if you're rebooting your Hubitat hub, you can still control the device with Apple Home).
Adding to this, it might also be easier if Hubitat could commission Matter over Wi-Fi devices, but at the moment, the reality for any Matter device is that the device needs to be commissioned with another controller first. (Part of the complication here is that commissioning normally requires Bluetooth, which would require some changes to the mobile app to work; staff have posted some hints that changes are underway, though no guarantees or timeline.)
There are still compatibility advantages to Matter; the concerns above seem to stem mostly from the physical/network layer. But for example, if you are selling a device and use Matter as the application layer instead of HomeKit, your devices can work with not only Apple Home (as either protocol can) but also with other Matter controllers directly (like Hubitat ... once commissioned, for now). The advantage is even greater if the alternative is a vendor-specific walled garden. Drivers on the hub should also be easier to write (if needed at all--there are a number of "Generic..." drivers now that work for many different devices) if the spec is followed, given fewer manufacturer-specific quirks.
All this info that you guys have provided has given me a better understanding of Matter and all the layers that you referenced. I will let you know if I have any more questions. Thank you all.
The thread ones are possibly better for battery powered devices as it uses less energy - or at least that's the idea. My inclination is to go for direct wifi for powered devices as it removes one more layer of complexity - unless I need a powered thread device in a particular location to act as an extender for thread signals.
