Smart Home communication

Zigbee, Z-Wave, Bluetooth, Wifi, RF and Infrared. These are all methods of communication without wires. Some of them are light based (Infrared), some are radio based (Zigbee / Z-Wave / Bluetooth / Wifi / RF). They’re just ways that devices can talk to each other.

The below is an explanation of what each of these technologies are and what they are used for. It’s helpful to know as you’ll see reference to these throughout the smart home world.

Zigbee

Communication is 2 way, so bulbs for instance can say ‘I’m on and at 50% brightness’. Devices can be cheap. Communication is quick and ‘burst’ based, so the radio is rarely active, making it suitable for battery operated devices such as sensors. Works without an internet connection.

Devices such as bulbs are more expensive than Wifi or RF devices. Requires a separate hub or USB stick.

Philips/Signify Hue products are Zigbee based.

Z-Wave

Identical in many ways to Zigbee, it is a competing protocol.

There are less options for Z-Wave hubs available, however dual Zigbee/Z-Wave hubs exist such as Smartthings.

Bluetooth

You most likely already use Bluetooth for listening to music on a wireless speaker, or you have a smart watch such as a Fitbit that communicates with your phone via Bluetooth.

As Bluetooth is found on a number of personal devices, it is cheap and quick to provide apps that control devices within the home. It is also simple to implement and is capable of quick transfer of a lot of data. A separate hub is not needed. Internet access is not required.

Bluetooth is short range (around 10m/30ft). The connection is designed to be constant, so is a greater drain on battery power, making it unsuitable for battery powered devices. Cost is greater than Zigbee/Z-Wave devices.

The latest Philips/Signify devices also offer Bluetooth control in addition to Zigbee, allowing direct control from a mobile phone without a hub.

Wifi

Chances are, you have a Wifi network of some kind already set up and running. As such, it is cheap to implement and is reliable. In many cases there is no separate hub required as the protocols are built into your router.

The disadvantages however are that you are reliant on a working internet connection. Many device manufacturers will use a 3rd party integrator such as Tuya or have their own systems. If your internet connection goes down, or the system it’s based on goes offline, or the company behind them goes out of business or decides to make certain products obsolete, then you’re left with devices that will no longer respond to instructions. In addition, as Wifi is regarded as an always on connection, it is not suitable for battery based devices due to the current drain. Too many devices using Wifi can affect other devices on the network.

RF

Normally operating on the 433Mhz or 315Mhz radio band. Communication is one way, so devices tend to be cheaper. Fairly reliable so long as the distance is not far.

One way communication can be a disadvantage, particularly if you wish to know a command was carried out. Only suitable for switches or simple bulbs, not sensors due to the lack of return communication. Equipment from one manufacturer will often only work with their own products.

Infrared

Uses the same protocol your TV remote uses to communicate with your TV. It’s very cheap to implement. An infrared sender unit can control multiple devices making it suitable for controlling several A/V devices at once, for instance to change your input source on the TV, switch on a satellite receiver and your sound bar.

Like RF, it is one way. Device manufacturers also use a different set of codes, so it makes it difficult to integrate equipment from different manufacturers. Infrared relies on ‘line of sight’ communication so it is only useful for devices that are in the same room.