This question comes up a lot, do you need a hub? What about just sticking a bunch of WiFi plugs/switches in and calling it a day? Or what about Hue with their motion sensors, that automates my lighting right?
The truth of the matter is, no you don’t NEED a hub but it can greatly improve your automations and allow dissimilar devices to be pulled into a central platform. There are also some security and performance considerations vs just using WiFi devices.
Let’s explore some of these!
This is a pretty lengthy post, if you just want a summary click here.
First and foremost, WiFi congestion. WiFi is a half-duplex medium. Only ONE things can be transmitting at a time. While smart devices don’t need a lot of bandwidth they DO chew into that airtime. Also your typical consumer router will crap out usually around 50-80 devices connected. Think about all the stuff you already have there? Phones, tablets, game systems, laptops, etc. Throw a dozen or two smart plugs in there and it’s not hard to get up to those limits. You also likely want to keep WiFi reserved for things that NEED it such as voice assistants (Echo, Google Home, etc) or other things that cannot talk directly to a hub or plug-in (Harmony and EcoNet come to mind). There is also a security piece here. Most of the time things on your WiFi have unlimited access to send data anywhere on the Internet. If this is a smart plug you may not care, but what about a camera? Do you want that potentially streaming your every move to some random country?
Closely related to the above is performance. Even though your WiFi may still be up and running with 80 devices attached, the truth of the matter is you will start to have issues with reliability and lag of commands. If you are streaming Netflix to 3 devices on your WiFi there is less airtime for those smart devices to talk. This can lead to delays in commands reaching your devices meaning they may not respond as quickly as you like. Also most of these devices use cheap WiFi chipsets that operate only on the 2.4 GHz band which in densely populated areas is polluted to the point of sometimes being worthless.
So how does a hub solve the above problems anyway? Simple, using other protocols. Most hubs allow use of Z-Wave and Zigbee devices rather than WiFi. These devices operate on other protocols, are typically smaller/cheaper, and use less power making them idea for battery-powered sensors.
That’s a good lead-in to the next bit – sensor/device availability. Z-Wave and Zigbee sensors and devices are FAR more plentiful than their WiFi counterparts. There are also many things you simple cannot get in a WiFi version or at least cannot get economically/off the shelf. Some examples are garage door tilt sensors, multi sensors, and micro relays. Battery life is also a HUGE plus as I alluded to above. Z-Wave and Zigbee sensors can many times last a year plus on a battery. Good luck doing that with a WiFi device. Z-Wave and ZigBee devices can also hop through other devices on the same protocol forming a mesh and extending your range much further than a single WiFi router.
This is a good lead-in to interoperability. If you pick, for instance, a TP-Link smart plug without a hub you can control it from the app. You can add more TP-Link plugs but you cannot add a WeMo and control it from the same app. You are, more or less, locked into the ecosystem. A hub allows you to control ALL your smart devices from a central point. It also allows automations to span manufactures and protocols. Your Dome Z-Wave sensor could trigger a Hue light to turn on as an example. You can also get more complex with these automations having that same sensor only trigger if it is after sunset and nobody is home. And since you are not locked into one specific manufacture you can buy stuff as it goes on sale to save a few bucks here and there.
At this point you are probably thinking “This sounds great and all, but what’s the catch?” The big one is that there currently isn’t a “magic bullet” hub that fits everyone’s needs. Cheap, local, easy – pick 2. Everyone telling you which hub is best is probably right…for their setup. That may mean diddly squat for your setup. Also complexity it another potential downside. *Most* of the time hubs aren’t plug and play. There is at least some initial configuration that needs to go on. It can also be a pricey up-front investment. And over he long run SHOULD pay off, spending the money up-front can be a challenge.
Whew, that was quite a list! To summarize, pros and cons of a hub:
Pros:
- Keeps devices off WiFi and from (directly) talking to the Internet
- Further range by utilizing the mesh abilities of Z-Wave or Zigbee
- Greater battery life and larger array of sensors
- Vendor agnostic – No lock-in to a single ecosystem
- Greater flexibility with automations
Cons:
- Typically higher up-front cost
- More complicated setup
- No “magic bullet” solution for everyone
In summary, you don’t need a hub but it will greatly enrich your automation and open doors that simply aren’t there without one.
Happy Automating!
-Dan