It’s a question we get frequently and if you’re building a new smart home it’s important to understand the differences.
Let’s first talk about frequencies – or the radio spectrum at which either device family operates at. Z Wave uses a licensed frequency in Australia 921.4 Mhz & 919.8. Why is this important? Well, it means that only devices resold in Australia/NZ on those frequencies are licensed to operate. As the spectrum is licensed , it means that running devices in frequencies other than these is illegal. This keeps things clean – it’s like having only one person at a time talking over air traffic control. It also means that any Z Wave device you buy in Australia will operate with any Z Wave controller also purchased in Australia.
Z Wave vs Zigbee
So how does this differ from Zigbee? Well, Zigbee uses a much higher frequency , used by others such as WIFI devices, Microwaves etc. Whilst this higher frequency of Zigbee is useful for being able to send more data (Higher the frequency, the higher the data rate) it’s isn’t overly that useful in a smart home or home automation sense as there is no real need to do so. Smart home messages are typically very simple, ON/OFF, DIM, etc. To send this data you really don’t need a very high bandwidth at all.
Being also on the 2,4Ghz frequency means you’re far more susceptible to interference from many other devices. Think about the air traffic control example used earlier – everyone talking at the same time. Naturally, this is a simplification and higher bandwidth devices have some measures in place to allow ‘fair air time’ but, at the end of the day, do you want your lighting devices of which you depend on so well, all talking with your mobile devices, PC’s, Laptops and Microwaves? We don’t. We prefer our automation platforms to be on a purpose built, low frequency licensed spectrum designed for only that use case – home automation. And this is where we think Z Wave really has the edge. It’s been designed from the ground up, specifically for one purpose and uses a licensed frequency that is free from congestion.
What we haven’t talked about is the benefits of low frequencies. Whilst the trade off with a low frequency is that it has much lower data transfer, we also mentioned that this isn’t really an issue in the home automation or smart home sense due to the size of the data being sent. You can think of Z Wave as a bit like your old CB Radio – it’s capable of going very very long distances. Because of this lower frequency, it has significantly improved transmission distance and able to penetrate materials such as brick, plaster, glass and other building materials much better than Zigbee at 2.4Ghz. This is important because of the diverse range of material homes are now built using.
Techdemic have a great article about distances and data transfer that’s worth checking out here.
We recommend our customers make use of Z Wave. Being a purpose built system designed from the ground up for home automation and smart home control, with longer transmission distances and a licensed low frequency radio it’s better suited in our view to Zigbee because of the issues highlighted previously.
Give us a call or drop us an email if you’d like more information on the two and which is the right one for your new smart home.