What You Need To Know About Protocols (and Nothing Else)

computer protocols wordle
Hubs & Controllers Smart Home Living

Today’s smart house is actually a network of tens, or hundreds of small devices that each has a specific task to perform. They include the timers on each of your smart lamps, the sensors in your water leak detectors, the switches within your electronic blinds and so on. Managing the communication between all these devices is a home controller, or smart hub.

Before you shop for the best smart home hub you have to shop for something else; the protocol all of your smart home automation technology will share. Yes, it does sort of mean what you think.

In technical terms, a protocol is a set of guidelines that covers communications between different kinds of computers. Since software for a mainframe is written in a different code language than that for a Unix box, a PC laptop or a smartphone, protocols act as ambassadors. They cover the rules and procedures that determine how these computers talk to one another like who should initiate the contact, how they should transmit information and what the acceptable responses are.

Why choosing a protocol is important

In terms of smart home technology, swap out high-powered, complex computers for simple, low-power devices and the rest works pretty much the same. The power level involved is important (as you’ll see in a bit), but so is how signals are transmitted. Without wires, they all use radio frequencies to transmit.

Choosing one protocol over another is arguably the most important decision you’ll need to make when putting together your smart home.

Why? How the devices in your home talk to one another and what language they share will determine what products will work well with one another and/or what brand of products you should shop for.

It’s a lot like choosing whether you want an Android or an Apple smartphone. Strong arguments can be made either way, but there is no definitive “this is the best” answer. There are, however, a few situations we’re going to cover today that you can use to help make your decision.

But first, some fine print

If you have your heart set on one particular device, but it doesn’t use the same protocol as another device you already use, don’t despair. There is a chance you can still make everything work – especially if you’re willing to put a little more effort into learning and executing some network modifications.

keep it smart

Even when the device languages are very dissimilar, you may still be able to get one protocol to talk to another. There are “recipes” that you can write that will cover certain situations to bridge the communications gaps (IFTTT statements). However, that’s a pretty huge subject on its own that we’ll cover another day. For now, let’s take a look at your basic options.

a kiss

keep it simple

Remember, here at Smart House Manager we value simplicity as much as smarts. We want to recommend individual devices and whole systems that will do what you want with the minimum learning curve both during installation and maintenance. We’re not going to split frog hairs over the “latest, greatest and smartest” unless it really makes a difference in your daily performance.

Besides, the minute we do, technology will take another leap forward and everything we say will be out of date. There’s a new protocol making its way through development right now called “thread.” We’re keeping our eye on it and will add it to our charts, etc. when it’s developed to the point of having a number and range of devices that use it that suggest it will become a major player.

And one last disclaimer for all of you out there who really are mechanically inclined and tech savvy. Yes, we know we are slurring over all the good bits and juicy details. If you really think we’ve left something out that is crucial to making a decision on which way to go, will you please join in and add your comments below.

Basic Smart Home Protocols

There are plenty of distinctions between each protocol that may or may not matter to you and some cases where one might work better for you than the other. We’ll cover those in a bit, but let’s start by introducing you to your options.

We break your protocol choices down this way:

  • Wifi
  • Bluetooth
  • Z-wave
  • Zigbee
  • Proprietary (Insteon, HomeKit etc.)

Don’t see a particular flavor on the list that you were expecting or that someone else had recommended to you? You can bet on there being plenty of new entries as more companies jump on the home automation bandwagon, but for the foreseeable future, we think these categories will hold all comers.

Just read through the first section here and we’re pretty confident that your mystery brand will actually act the same as one of these categories. (If not, if it really is something new, please give us a shout so we can check it out and make updates to this guide.)

Let’s go through and take a look at what each protocol is based on and what it does. Then we’ll come back and talk through a couple of situations that will help you choose one for your home.


wi-fi logo

We’ve all become pretty good at understanding that wi-fi enables devices to work together without actually being wired together. Wireless local area networking relies on radio waves to provide high-speed internet connections between computers and devices like printers, iPads, and other “peripherals.”

However, what you probably don’t realize is that it actually takes a lot of power to push that information back and forth that way. One wi-fi network anchored with one router can cover your entire house. Carrying large packages of data over long distances like that is what makes your wi-fi network so powerful.

Wi-fi does play a role in your smart home automation scheme. For now though, it’s largely confined to your entertainment devices. Your smart TV, video streaming control box and whole house stereo system all need the speed and power of wi-fi to deliver movies that can be paused on a TV and resumed on a tablet or music that’s streamed through your surround-sound wireless speakers.

That range and data packet size add a power cost that makes wifi impractical as a backbone for the smaller devices that power most of a smart home. Most of the devices you will want to add to your smart home deliver simple, straightforward commands and are physically too small to carry large batteries.

Two to four AA or AAA batteries could, or should, run some of them for years. Force them to run on wi-fi and you would have to be up on a ladder changing out the batteries in that motion-sensitive floodlight above the garage door literally every other day.

That’s decidedly not smart and not simple.

The allure of home automation is that it makes your life easier. You can control your home from your smartphone over the internet with a tap of your finger. To achieve that, there are two steps to getting information to or from each one of your “timed” lights or thermostat to the application on your phone.

Devices create mesh networks

diagram of a simple mesh network

each device can push a message to the next device

The first step is getting each of your separate devices to talk with one another. Your living room lights can be connected to your dining room lights, for example, because they are in close proximity and share the same “dialect” within the protocol. Because they can reach each other, they extend your new mini-network a little further down the hall. Now you can connect your bedroom lights to the mix. This builds what’s called a single power mesh. This specific standard (dialect) for low-power devices has not been adopted the same way by different companies. Our other protocols represent these dialect variations.

Clearly, wi-fi is not the network of choice for your devices, but it is where they must turn for orders. A smart home hub is the device at the end of your little mesh network. It connects to the Internet via your wi-fi network and waits for your cell phone signaled order to turn up the heat because you’re leaving work. It also waits the required 25 minutes, then tells the lights to turn on because you should be home in two minutes.

Bluetooth LE

bluetooth LE logoBluetooth is also a widely recognized and understood by anyone using a cell phone. However, we’re not talking about using your cell phone carrier to power your smart home network. It too is too big and too robust for the job.

There is a “dialect” of Bluetooth that was specifically designed to translate and carry messages between the small devices in your home. It’s Bluetooth Low Energy (BLE) which is also sometimes called Bluetooth Smart.

Bluetooth LE does, however, share the same radio frequency as your cell phone Bluetooth. This means that it can, in some instances bypass a hub and you can control a device directly with a cell phone app.

First applications of Bluetooth LE were largely in the medical field. We tend to think of our smart house applications as breaking new ground, but in many cases, our tech has been adapted from commercial uses. In this instance, the Bluetooth LE signals that sent info to hubs about glucose levels and monitored temperatures can now sense motion and monitor temps at home.

And yes, they brought their drawbacks home with them. The size of the information package that can be transmitted is much smaller than one usually transmitted via wi-fi, and the range that it can transmit over is much smaller too. But, since it still uses the same radio frequency as the bigger Bluetooth network, there is a greater chance of interference if too many devices start talking at once. Latency and drop outs will happen.


z-wave logoJust the number of different spelling options for z-wave should tell you something about this protocol. It was developed by an organized group of manufacturers who wanted to develop a common standard that everyone could rally around and develop products for. Look around the Internet today and you’ll see it spelled z-wave, Z wave, Zwave and z wave. It’s the same term, but everyone has added their own flavor.

Interoperability was and is the goal and strict standards have led to more than 1,500 different devices being certified by the Z-wave Alliance. You will be able to connect your Philips Hue Lights and your ADT security system using z-wave. In a couple of years, you can add in an LG refrigerator with confidence because z-wave is also backwards compatible, so your new z-wave device will work with that 10-year old device.

In fact, you can pair up to 232 different devices in your z-wave mesh network in much the same way you pair a Bluetooth headset to your smartphone. And, because z-wave operates on a lower frequency than wi-fi or Bluetooth LE, you won’t experience as much interference.

Sadly, however, if you adopt z-wave for your house here in the US, you won’t be able to take any of your devices with you when you realize your dream and move to Europe or Australia. The z-wave frequency used is different in different countries so interoperability stops at the border.


zigbee logoZigbee operates at the same radio frequency as wi-fi and bluetooth. However, it was designed to use the smallest amount of power possible, which makes it ideal for the small device world. It provides the ability for your lights and alarm systems to run for years on the same batteries.

The power-sipping nature of Zigbee make it the most affordable option but also limits its data packet size.  The data package it transmits is small and must be very simple. Unfortunately, putting a Zigbee mesh network together is not necessarily simple. It can be confusing to the tech savvy to work through what does and doesn’t work together and how.

But once you’ve worked through that you can put a bigger mesh network of Zigbee devices together. A Zigbee signal can hop up to 30 times to and from its hub where a z-wave can only go through four. The price is unfortunately, latency. Combine that with interference from bluetooth communications or too many devices operating at any time and you have some reliability issues to deal with.

Also, while there are hundreds of brands and devices that are perfectly happy working together through Zigbee, there are no rigid standards in place to make sure that they are all compatible.

Proprietary Protocols…

insteon logoSince all these protocols are new(ish), there were those companies that didn’t want to bet on a favorite. No one wants to sink a lot of money into developing the next Betamax. What companies are always willing to bet on, however, are themselves. Closed system options have appeared that are designed from top to bottom to work together.

Insteon is the biggest proprietary protocol, closed loop smart home solution that comes to mind. It is not only a home automation protocol. It is a complete package that includes sensors, dimmers, light bulbs, cameras and more. If you’re at all techie, you’ll recognize this as akin to a Unix system where the solution is half software and half hardware.

Deciding to go with a proprietary system does make your purchase path simple. All of the items you purchase must come from that brand. Unfortunately, if there isn’t a water leak detector offered by your preferred brand you can’t usually plug in someone else’s option. And if your brand offers the light or window blind controller with the lowest rating or highest price tag of all, you are pretty much stuck with it.

Luckily for you, there are some exceptions. If you’re in the market for a Nest thermostat, for example, it will work with your Insteon network. It’s one of the few proprietary systems you can plug a Nest into.

… and Reverse Proprietary Development

Most companies today have chosen to go the other way. Because there is no single standard yet (and may not be for another five to ten years), they instead are manufacturing their devices to work with two, three or four different protocols.

The Samsung Smartthings Hub and the products that work with it are a good example of this. The hub works with all four protocol but is easiest to set up and use with the set of devices specified as part of its network.

On the horizon: Thread

thread logoIn late 2014, Google Alphabet joined with Samsung, Qualcomm, ARM Holdings and others to create the Thread Group. They’re working on yet another protocol they call Thread that they hope will become the standard that all smart home devices are built upon. It hasn’t happened yet.

Thread is much like Zigbee (and in fact often develops with Zigbee) except that it runs over IP instead of radio frequency. Instead, it has become “one more protocol” supported by many of the companies building devices.

Which protocol is best?

We’ve seen very few clear examples of good and bad choices in our look at the protocols:

  • Don’t buy into the package wrapper claims of “seamless wi-fi-connectivity.” Who needs a bazooka in a fist fight?
  • Don’t buy z-wave if you get moved by your company to a new country every two years unless you believe it will substantially add to the resale value of your home
  • Do plan on a Zigbee installation being a little trickier than an Insteon setup, and finally
  • Do go with z-wave if you plan to build out your whole house technology slowly as you know you won’t need to worry about old and new devices mixing

There’s a reason the list is so short.  Protocols will very rarely be the reason you do or do not buy a particular device, but they are something you should be aware of as you are shopping for your total home automation system.

Even if you are thinking of building a new home and would like to have smart devices included throughout, you will still need to go through the shopping exercise. There is no right or wrong answer there either.

While there are some regional companies offering complete installation of closed systems, not all builders are up to date or able to customize a plan for you. You will still probably need to install their base thermostat, for example, then swap it out yourself once you have moved in.

Our recommendation

We don’t think protocols are a deciding factor in building your smart home. Instead, we view them as useful tools for filtering out choices for you.

There are two ways most people approach the smart home technology:

  • They learn about a particular device and want to use that in their house
  • They learn about Alexa and Google Home Voice controllers want to control their home systems that easily

In either case, there are layers of communication have to happen across opened and closed spaces to make each a reality.

And the one thing that sits in the middle of all that communication is not a protocol, but a smart hub. It’s that hub that’s going to interface between your devices and the Internet; between the voice controller or smartphone app and the thermostat, TV and lights.

To use an earlier example, if you want to own a Nest thermostat, then you won’t want to buy a Samsung Smartthings hub because their protocols are incompatible. But you could still look at the Wink, or consider going with Insteon.

On the other hand, the whole Smartthings system is very popular for several reasons (that you can learn about here). If that’s the system you think makes the most sense to run your house, you could use an ecobee 3 thermostat or the Honeywell Lyric.

Of course, there are always workarounds and recipes and new versions that will open up new worlds of possibilities. But our bottom line is this, while there are always exceptions, we think choosing your hub first is the smartest choice. Then knowing your protocols should make sorting through all your devices choices a little simpler.

Smart and simple; that’s the way we like it.

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