By this point, you’ve probably seen or heard about smart devices, sometimes referred to as IoT (Internet of Things) devices. These gadgets usually provide some automation features, an ability to be controlled via a smartphone app, and further remote access using a web-based portal and cloud technology, just for starters.

But how do these smart devices actually work? How do they communicate with each other? Is that communication secure? Fast? Energy efficient? How far do they reach? Which smart devices will work with others and which won’t?

We’re going to dig a little deeper on some of the underlying technology behind smart devices and the network protocols they are using.

Wireless Networking Standards

As far as wireless communication between devices goes, you’re probably familiar with WiFi and Bluetooth. WiFi is how all of your computers, smartphones, printers, etc. connect to the internet within your home. Devices use WiFi to interface with a central wireless router, which links to a modem (or has one built-in), which connects to the internet at large via an Internet Service Provider. WiFi’s main advantages are that it is fast and can transmit a large amount of data. That makes it perfect for things like streaming video and music, which you likely use it for often.

Bluetooth is another commonly found wireless protocol. It is frequently used for peripherals like a computer’s wireless mouse and keyboard, and for syncing data with wearables like fitness trackers or smart watches. Bluetooth is simple, reliable, and requires relatively little power to transfer data, hence it being the protocol of choice for simple devices with frequent data transfers, such as a mouse.

WiFi and Bluetooth, however, are not ideal IoT devices for a few reasons. WiFi is power-hungry, meaning that any smart devices like your home security alarm panel, smoke detectors, or thermostat would end up requiring aggravatingly frequent battery changes, or their own dedicated power adapters, which isn’t really feasible for a device like a connected door lock. Bluetooth uses less power, but is limited in its range as well as in the number of device connections it can handle. Thinking about how far apart your outdoor security cameras are from the smart lightbulbs in your basement illustrates the first problem. As we move toward a future where nearly everything in your home has the potential to be a connected device, a limited number of connections also makes it clear why an alternative to Bluetooth is needed.

Catching Z’s

Fortunately, there are other wireless networking standards for your smart devices to rely on. You may not have ever heard of them, but they’ve been around for over a decade, helping everything from cable boxes to washers and dryers communicate. The two most popular protocols are called Z-Wave and ZigBee.

ZigBee and Z-wave have a lot in common. They both provide low-power, relatively long-distance communication between hundreds or even thousands of devices. Both use AES-128 symmetric encryption (which is what online banks use). Both create what is known as a “mesh” network, that allows any device to communicate with any other device on the same protocol, as well as extend the range of the network. They can also both use a low-frequency radio band (915 MHz and 908 MHz, respectively) that won’t interfere with WiFi routers, which use a 2.4GHz or 5GHz frequency. Z-Wave and ZigBee both require a central hub for all devices.

While many devices are compatible with both Z-Wave and ZigBee protocols, the two standards are not able to interface with each other, and most manufacturers end up choosing one or the other. Z-Wave and ZigBee are probably more similar than they are different, but there are a few key differences. Z-Wave’s main advantage is probably its interoperability with Z-Wave. Z-Wave is specifically engineered to have maximum compatibility, and backward compatibility, with all Z-Wave devices past, present, and future. ZigBee, on the other hand, has a greater maximum data rate, up to twice as fast as Z-Wave’s, and the ability to have thousands of connections on its network.

At the end of the day, Z-Wave and ZigBee are both fine protocols which offer similar features and advantages over WiFi and Bluetooth for IoT device communication. The important thing is to be aware of which protocol the devices you purchase use, and whether or not all of your devices can be compatible on the same network.