Home Automation Protocols: How Your Smart Devices Work Together

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You?ve probably heard a lot of buzz about smart devices lately. Smart refrigerators, smart ovens, smartwatches, even smart toothbrushes. When you put all of these things together, you can have a whole smart home!

But how do all those devices work together, and where is that communication happening? The question of how home automation protocols work is a fascinating one that can give you new insights into the smart home wave. Read on to learn more about these systems and how they work.

What Is the Internet of Things?

The internet of things is the concept that individual items in our home could talk to each other and a larger cloud network to make automating our lives easier. The idea is not a new one; any sci-fi show you?ve ever seen that shows a toaster that will talk to you is working with the internet of things. But in recent years, those futuristic visions have started to become a reality.

First, the obvious things were made, smartphones, TVs, computers, and home assistants. Then came the doorbells, locks, light bulbs, ovens, refrigerators, outlets, watches, thermostats, and the like. These days, anything could be smart ? your Oral-B Pro 7500 toothbrush, your Etekcity digital kitchen scale, even your Hidrate Spark 3 water bottle.

What Can Be a Smart Device?

In general, if an item comes with a measurable amount of usage, it could be made smart. Let?s take that Oral-B Pro 7500 toothbrush for example. The toothbrush could, through the internet of things, keep up with your average brushing time, let you set a streak for brushing your teeth twice a day, and even help remind you to brush for the recommended two minutes.

Things may also be considered for ?smartification? if they could benefit from outside data. Refrigerators and stoves are a great example of this kind of technology. Let?s say you tell your smart home assistant that you want to cook chicken cordon bleu for dinner tonight.

In theory, your fridge could check the ingredients you have on hand and order any you don?t have for pickup from your nearest shopping center. Your oven could start preheating to the needed temperature so that it?s ready when you want to put the dish in the oven. And your smart home assistant could add a portion of that meal to your daily calorie tracking app.

How the System Works

Making all these smart items we?ve been talking about is more complicated than just giving them wifi capability. There have to be protocols and chains of communication in place to make sure everything is communicating well. Otherwise, you wind up with the digital equivalent of a dozen voices all shouting in a room at once.

We?ll dive into these steps more in a moment, but this is the basic communication protocol most smart home systems use. Each device communicates with a gateway and with other similar devices as needed. The gateways communicate with either data centers or the cloud depending on the system.

Device to Device

Sometimes devices communicate directly with each other rather than going through a gateway to manage operations. Right now, this isn?t very common because it requires a level of sophistication most devices don?t have. For now, you still need a dedicated gateway to handle inter-device communications.

Most of the time you find device-to-device communications in industrial factories. Industrial robots and sensors talk to each other directly to help coordinate their activities. This allows them to work more efficiently.

Device to Gateway

In most cases, devices will always communicate with a more sophisticated gateway device. The gateway device is capable of working with a variety of different devices and acting as a mediator between them and the data system or the cloud. You may also hear gateway devices referred to as hubs; these are technically different, but often such devices will serve as both gateways and hubs.

So let?s go back to our chicken cordon bleu dinner example. When you tell your smart home assistant that you want to make chicken cordon bleu, it tells the gateway that information. The gateway then tells the oven to heat up to 400 and tells the fridge to check if you have chicken breasts, Swiss cheese, and deli ham.

Once these commands have been sent out, the oven tells the gateway that it?s preheating to 400. The fridge tells the gateway that you have chicken breasts and deli ham, but no Swiss cheese. The gateway gets in touch with your grocery store shopping app on your phone and tells it to order Swiss cheese from the grocery store for you to pick up on the way home from work.

You may be wondering how your Amazon Alexa works if it doesn?t have a gateway or a hub device. In addition to working as smart speakers, the Echo Dots serve as gateways to manage the rest of your smart home system.

Gateway to Data Systems

Although your gateway can handle communications from your specific devices, it also has to reach out to larger data systems to handle everything it needs to. This could include displaying your Facebook feed, checking the conversion charts for tablespoons to cups, and putting on the morning news. The gateway acts as the mediator between your devices and the internet at large.

Sometimes the gateway may reach out to the internet to get specific information (for example, details on that chicken cordon bleu recipe). Other times it may coordinate with a cloud storage system to add or remove items from a list. This is how it can manage a grocery list you can access from any device or access your favorite Amazon Music playlists.

Distance Range

The distance that devices have to communicate across varies wildly from a few micrometers to several miles. There are different network types to handle communications across different distance ranges.

The smallest networks, nanonetworks, near-field communication networks, and body area networks, are designed to allow communication for devices that will sit no more than a few inches away from each other at most. Personal area networks and local area networks cover part or all of certain buildings. And metropolitan area networks and wide area networks are designed to cover and support whole smart cities.

Different Protocols

There are several different methods through which all your smart devices communicate. Think of it as your devices writing letters versus emails versus talking in person versus using sign language. Which one your network uses depends on the individual device and its particular needs.


Cellular protocols work through the same network that handles your phone calls. The advantage of this protocol is that it is universally recognized because of its integration in the phone network and it offers a very stable connection. It?s a good option for devices that need constant connectivity.

But sending messages through cellular can get expensive, as anyone who?s ever seen a jacked-up data bill can attest. This isn?t a practical financial option for most people, so it isn?t the most popular in current smart home devices. But given the growing popularity of unlimited data plans, we may see this protocol option pick up in the next few years.


WiFi is a great option for most device connectivity in your home. It?s affordable and well-protected, and it offers universal smartphone compatibility. WiFi networks are also large enough to reach most areas of your house, especially if you use signal extenders to boost the range.

But as you?ve certainly discovered whenever you?ve been trying to download your favorite movie or get concert tickets, WiFi can be unreliable. Depending on where you are, a stormy day can may interfere with your internet connection. You may also see this system slowing down the more devices you add to the network due to bandwidth issues.

Radio Frequency

Radio frequency communication is a protocol that long predates the era of smartphones and smart homes. This protocol sends radio waves through the air where they can be picked up by an appropriate transmitter. It?s a simple, reliable protocol, and sometimes, the simple solutions are the best.

But as you probably know, smartphones don?t work with radio waves. So if you need direct phone connectivity, this option won?t get you there. Without a central hub that can act as a translator, your devices will only be able to connect to other radio-enabled devices.


If you?ve ever tapped an ID card on a lock to open a door or started your car without getting your keys out of your purse, you?re familiar with RFID. Radio frequency identification uses electromagnetic fields to identify specific objects ? your individual car keys, for instance.

RFID tags can be used for devices that need to communicate with each other within 200 meters. They do not require power, and they?re a widely used technology, but they are very insecure. They are also not compatible with smartphones, so you?re back to the same problem as with other radio frequencies.


We?re all familiar with Bluetooth protocols, and, indeed, Bluetooth is one of the most popular smart device communication protocols. This protocol allows two Bluetooth-enabled devices to pair with each other and share information as needed. Their openness about which services they provide can also make security and permission configuration much easier to automate.

Bluetooth technology is evolving every day, which is both a good and a bad thing. On one hand, you can always expect the latest and greatest in Bluetooth on any device you buy. But on the other hand, those devices go obsolete very quickly and will need replacing.

Near Field Communication

Near field communication, or NFC, is expected to overtake RFID technology for smart device communication in the next few years. This protocol uses an electromagnetic induction between two loop antennas that are located within each other?s near field. They run off of the power generated by those electromagnetic fields; a common use of this technology is QI wireless charging.

NFC has two main communication modes: passive and active. In passive communication, each device draws power from the electromagnetic field of the other, maintaining a sort of constant ?You awake?? loop like you used to have at sleepovers. But when it?s time for the secrets to come out in the active mode, the device telling the ?secrets? will turn on its electromagnetic field, while the ?listener? will deactivate its own field to listen to the data.


If you have a collection of small scale devices that need low-bandwidth connection, Zigbee is a good communication protocol. You see it used mostly in industrial and medical settings. It comes with lots of DIY configuration options, which make it great for people who want customization power.

Zigbee does use standardized pairing requirements for devices, so it will connect to most of your gadgets. This can help make it a little cheaper than some other gateway options. It does have a low data bandwidth, so make sure that will work for the applications you?re looking at.

Data Distribution Service

Data distribution service, or DDS, is a protocol that works based on a public-subscribe framework. Think of it like a Twitter feed for your smart home devices. There are nodes in the service that work like accounts and publish topics that subscribers might be interested in, like tweets. If the other nodes in the system express an interest in that ?post? they can subscribe to it and to topics like it.

As social media has already discovered, this sort of framework is a great way to get information to the areas that need it without overwhelming everyone with information they don?t need. This system is involved in smart energy protocols and in medical settings for coordinating clinical information.

Learn More About Home Automation Protocols

Having a smart home can make your life far simpler. And knowing how all your home automation protocols work is a good idea for anyone considering setting up a smart home system. The more you know about how they operate, the better prepared you?ll be to set up a solid system.

If you?d like to learn more about smart homes, visit the rest of our site at A Connected Home. We have information about smart lighting, smart cameras, and every other aspect of your smart home. Learn more about how smart home automation can increase your house’s value today.

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