There are a number of common home automation protocols that allow different devices to speak a common language. This is important because you may want to build your smart home with accessories from different manufacturers. However, you likely want to control them from a central app or voice assistant. For that to happen, the accessories need to communicate with each other.
This isn’t going to be an ultimate guide to selecting the best protocol. Unfortunately, we can’t tell you what is best because it all depends on what you want to do. However, we can help you understand each technology and what it does and doesn’t do well. Understanding the different protocols will allow you to choose a hub to control your system while also making sure you have the opportunity to grow.
Ethernet is a wired communications standard that allows large quantities of data to be sent very quickly. It is the leading communications method for internet traffic. The Ethernet standard is maintained by the Institute of Electrical and Electronics Engineers (IEEE).
Ethernet communications travel over physical cable made up of twisted pairs of wires. The maximum distance of a cable is limited to 328 feet (100 meters) and data transfer speeds are 1 Gbps (1,000 Mbps). Low-voltage direct current (DC) power can also be supplied over the Ethernet cables, which is helpful for home automation devices like cameras and doorbells.
There are two prominent Ethernet cable-types used in residential applications: CAT5e and CAT6. Both cables are capable of 1 Gbps data transfer rates at a distance up to 328 feet. However, CAT6 cables have a thicker gauge wire and include insulation techniques that limit interference and cross-talk issues. CAT6 cables are actually capable of 10 Gbps speeds, but only at distances up to 180 feet. CAT6 cables come at a cost premium of around 20% more than CAT5e.
CAT5e cables are acceptable for most residential applications, but you should install CAT6 if you can afford it — this will help future-proof the installation. Most people run a single Ethernet cable to each room that will have a TV or other media streaming device. However, if you are already installing cable, we recommend 2 cables to each TV plus a single cable to every location that you may want to install a security camera or doorbell.
An Ethernet network size is theoretically limitless, but you will have to connect a lot of switches to make that happen. Keep in mind that switches take up physical space and generate heat so home networks are usually small — perhaps 20-30 connected devices.
The benefits of Ethernet cabling are easy to define: data transmission speed and communication distance. In addition, cables tend to be more secure since they are buried in walls and hard to access. We recommend installing CAT6 Ethernet cables to every location you intend to install a media streaming device since they use lots of data, especially for high-definition video.
Ethernet isn’t perfect. A major drawback is the cost of installing the cables if you don’t already have them. Opening a wall and snaking a cable through existing construction is costly and messy work — and sometimes a pathway isn’t available. Cable installation is fairly cheap if you are renovating and the walls are already open.
Ethernet also requires a central data closet for locating Ethernet switches. All wires need to return back to a central switch that controls the traffic on the network. The data closet can be a simple wall-mounted rack inside an existing coat closet, but you still need to set aside space and plan properly.
Since Wi-Fi is so common in homes today, it makes sense that home automation accessories take advantage of its availability. While it is important that your hub devices include Wi-Fi, it isn’t the best protocol for all smart home accessories.
Wi-Fi is a wireless communication standard developed and maintained by the Wi-Fi Alliance. The standard allows interoperability and communications among different devices.
Wi-Fi communications travel across radio waves in the 2.4 GHz or 5 Ghz spectrum. Compatible devices include a receiver and transmitter plus connected antennae.
The theoretical range is relatively far, but for practical home usage, the maximum range is around 60-feet. Of course, range can be affected by many things including physical barriers, interference, transmitter power, and antenna quality.
Communications throughput is quite high; speeds range from 10 Mbps to 100 Mbps. Wi-Fi is capable of streaming high-definition audio and video.
Wi-Fi has a theoretical limit of 256 connected devices. Network congestion may become a problem before 256 devices connect, especially if some of those devices demand large amounts of bandwidth. You may have experienced this if multiple people in your home try to stream high-definition video at the same time.
The main benefits of Wi-Fi are transmission speed, range, and the overall availability of the technology. As mentioned earlier, most people already have a Wi-Fi router in their home and adding a router is way less expensive than running Ethernet cables around the house. Wi-Fi provides easy and fairly reliable access to the internet anywhere in your home.
From a home automation standpoint, there are a few drawbacks. First, Wi-Fi is susceptible to interference since there are so many devices competing for bandwidth — phones, tablets, watches, scales, streaming media devices, thermostats, and many others all want to communicate over Wi-Fi. The bands become even more congested as we add more devices to our homes.
Another problem is the power consumption of Wi-Fi devices. Wide range and high speeds require a lot of power to operate. While the power usage doesn’t affect our utility bills very much, the consumption is a problem for small sensors and other home automation accessories that need to run on batteries. Plug-in items can easily use Wi-Fi, but we don’t want to plug in every smart home accessory, especially very small items.
Let’s discuss range as a limitation. This may seem odd, since we also talked about range as a benefit. However, Wi-Fi range can be limiting in larger homes or those made from dense materials like concrete block. If this is the case for you, you have probably already installed additional Wi-Fi routers to create a mesh network.
Finally, security is something to consider. While Wi-Fi has plenty of security features to help keep your wireless network safe, they have to be set up and maintained over time. Wi-Fi itself isn’t a security risk, but when people disable (or fail to enable) proper security measures then the network can be compromised. Always make sure your network is secure and routinely check for router software updates.
The Wi-Fi Alliance understands the limitations with their technology and they are developing new Wi-Fi standards that will make it more beneficial for use with home automation. Wi-Fi 6 includes new features that improve range and power efficiency, while still maintaining data throughput. The new Wi-Fi Ha-Low is directed at the smart home market and is being developed to lower power consumption even further while also increasing the communication range. Wi-Fi will become more reliable for smart homes when these new versions are released. However, you will need to purchase a new router to take advantage of the technologies.
All of the hubs we have reviewed include Wi-Fi for easy wireless connectivity.
Z-Wave is a wireless communications protocol that was developed specifically for the home automation market. It was developed in 2001 by the Danish company Zensys and the current standard is maintained by the Z-Wave Alliance. Z-Wave is one of the more popular low-power wireless protocols for connecting smart home devices and accessories.
The wireless system operates in North America on the 908 and 916 MHz radio bands. Each device can send and receive commands or pass commands along to other devices. This creates an ad-hoc network, also known as a mesh network. The mesh network effectively increases the range of each device. If an accessory is out of range of another accessory, but within range of a third device, the message can be passed between in-range devices until it reaches the destination device. This is an advantage over non-mesh Wi-Fi networks.
Data transmission speeds vary between 40 and 100 Kbps, which is slower than Ethernet, Wi-Fi, Zigbee, and Thread. However the slow speed usually isn’t noticeable since Z-Wave is used to send commands rather than stream large amounts of data.
While the open air transmission range is 328 feet (100 meters), the more realistic indoor range is around 80 feet. The Z-Wave Alliance recommends that devices be spaced around 30 feet apart for the most reliable communications. Since Z-Wave acts as a mesh network, commands hop from device to device with a total outer limit of 600 feet. This allows effective communication across the largest homes.
Z-Wave networks can have 232 devices connected, which is plenty for most home automation systems.
There are a few benefits that have made Z-Wave so popular. First, the mesh network provides a more reliable network across longer distances. In addition, the network runs on the 908 and 916 MHz radio bands, which are less congested, so there is much less interference than other options. The newest Z-Wave standards require strong encryption in order for the device to receive certification. Finally, the radios use a very small amount of power so they can run on batteries, eliminating the need for a wired connection.
The popularity of Z-Wave means that there are lots of products to choose from. The Z-Wave Alliance claims that (as of late 2018) there are more than 2,400 smart home accessories on the market that use their technology.
The biggest limitation is slow transmission speeds, which limit Z-Wave to sending command and control functions. It isn’t the right technology for streaming high-quality audio and video. In fact, you won’t find any Z-Wave security cameras due to the slow transmission speeds.
Zigbee is similar to Z-Wave in that it is a wireless mesh network developed for low-speed, low-bandwidth, short-distance communications. It has become popular among home automation manufacturers, but it is also used in healthcare. The Zigbee standard was originally released in 2003 and is maintained by the Zigbee Alliance.
Zigbee radios operate primarily on the 2.4 GHz band, but some devices in North America also use the 915 MHz band. Each device can send and receive commands, as well as pass information to other compatible devices. This forms an ad-hoc mesh network that helps increase the communications range to cover an entire house.
Data transmission speeds are not suitable for streaming media, but at 250 kbps over 2.4 GHz radios, they are still very robust for sending and receiving commands.
Open air, line of sight transmission ranges are around 328 feet (100 meters), however the practical range within homes is around 30 feet. Since the devices create a mesh network, communications can hop between devices to greatly increase the 30-foot limit.
The theoretical network size is pretty large, at around 65,000 devices. We imagine you won’t be able to exceed that in your home, no matter how many devices you install. In practice, Zigbee networks can handle thousands of devices.
The two biggest benefits of Zigbee are the mesh network, described above, and the radio’s low-power requirements. The efficient use of power allows Zigbee devices to run on batteries, which also keeps them small.
The biggest drawback of Zigbee is the limited number of accessories on the market. It is simply not that popular and manufacturers have not started making lots of compatible accessories. However, Amazon has recently included Zigbee radios in their Echo Plus and Echo Show devices so we expect Zigbee to become more popular.
Many smart home devices include Bluetooth connectivity for close range communications. Bluetooth provides faster wireless data transmission than Z-Wave or Zigbee, but at shorter distances. Most smart phones include Bluetooth, which makes it a great way of connecting smart home accessories to your phone or tablet. Bluetooth is best known for local streaming of audio to headphones or speakers, but is capable of much more.
The Bluetooth technology was developed in the early 1990s and the standard is developed and maintained by the Bluetooth Special Interest Group. Bluetooth Low Energy, which is becoming more common in the home automation industry, was released in 2006.
Bluetooth is a wireless radio protocol that uses the 2.4 GHz band. The system runs as a Master/Slave setup, where one device operates as the master and up to seven devices operate as slaves. Devices can change roles, but there can only be one master at a time. The protocol uses a relatively low amount of power to operate, which means iaccessories can run on battery. However, its range is limited due to the low power usage.
Bluetooth provides faster data transfer speeds than many home automation protocols, but slower than Wi-Fi. Bluetooth 1 provides bandwtidths of around 1 Mbps, while Bluetooth 3.0 and 4.0 provide data transfer rates of around 24 Mbps. These rates are fast enough for high-quality audio transmission.
Range varies widely based on the class of radio in your device. Class 3 radios can communicate at a distance of about 3 feet or less. The more common Class 2 radios have a range between 15 and 30 feet depending on the environment. Finally, commercial quality Class 1 radios transmit up to 100 feet, but they are uncommon in consumer devices.
The Bluetooth SIG released Bluetooth mesh in 2017. Like Z-Wave and Zigbee, Bluetooth Mesh allows devices to pass messages between each other in hops, which extends the range of the overall network. We expect this to make Bluetooth a more common smart home protocol.
The biggest benefit of Bluetooth technology is its pairing method, which makes it incredibly easy for devices to discover and connect to each other. Each device has a profile that advertises what it is capable of (audio, hands-free, etc.) and other devices can see nearby device advertisements so you can choose to initiate a connection. The process is fast and easy.
Bluetooth also uses very low amounts of power so accessories can be small and battery operated. This is ideal for smart home sensors and other small devices that don’t need high bandwidth.
Finally, the Bluetooth technology is fairly inexpensive to implement and it is widely adopted in most phones and tablets.
Bluetooth isn’t perfect. It operates in the very busy 2.4 GHz frequency range, which makes it susceptible to interference from other wireless devices. In addition, the short range of communications make it hard to use across an entire home; although, Bluetooth mesh looks like a promising solution to this issue. Finally, the bandwidth doesn’t allow for video transmissions so the technology is best used for audio streaming or issuing commands among different accessories.
Most of the smart hubs on the market include Bluetooth radios, but you should check our reviews to confirm before you buy.
Thread is a new IOT communications protocol that is managed by the Thread Group. A number of major electronics companies are part of the working group, including Samsung, Google/Nest, Apple, Qualcomm, Tyco, and many others. The low power, IP-based, wireless mesh system allows for battery operated devices that communicate to each other and to the cloud.
Thread operates using the IEEE 802.15.4 wireless standard for low-rate wireless personal area networks, which is specifically set up for connecting devices together into a low-power, low-bandwidth mesh network. The radios run in the 2.4 GHz frequency range in North America. All devices run on an IP network, which means that your IOT devices connect to each other, but they can also connect to the internet. This is similar to Wi-Fi, but in a low-power and low-bandwidth package designed for home automation.
The practical range for low-power 2.4 GHz radios inside the home is around 30 feet. However, since Thread is a mesh network and devices can pass messages to each other, the overall network range is around 100 feet.
Thread is meant for IOT devices and accessories to pass commands and messages so high bandwidth isn’t required. Data transmission is around 250 Mbps, which is perfectly fine for smart home accessories. You won’t want to stream media over Thread, but that isn’t its purpose.
Thread has many of the same benefits as Z-Wave and Zigbee — namely, low power usage and mesh communications. Both of these are ideal for home automation accessories. However, the Thread Group touts the connectivity over the IP protocol as the main benefit. IP is used by our phones, tablets, and laptops so Thread can seamlessly connect to existing devices. This means you can generate a Thread network with existing devices so you don’t have to purchase a new hub. IP also has security standards that have been tested over decades so you know it will be safe.
The biggest problem with Thread is that it is so new and there aren’t many accessories that include the technology. We think that will change soon since the group is backed by so many big names in the home automation space. In the meantime, there isn’t much use for a Thread network.
None of the popular hubs currently incorporate Thread, but we expect that to change in the coming years.
Insteon is the most unique protocol on this list because it incorporates wireless and powerline technologies into a single network. This gives you the flexibility to install accessories anywhere in your home as long as you have either an outlet or a wireless signal.
Insteon communicates to accessories over the 915 MHz wireless radio band on a peer-to-peer network. In addition to wireless, Insteon also connects over a home’s existing electrical wires (called powerline communications). This creates a beneficial redundancy in the system.
The data rate on an Insteon network is around 180 bits/sec, but faster bursts are possible. This means the network is not capable of streaming media. It is restricted to passing home automation commands and messages.
Insteon’s wireless range maxes out at 150 feet without obstructions. The practical range in a building is around 30 feet with an extension up to around 100 feet via the mesh network. Wireless range is usually not a problem for Insteon since it also includes powerline communications to any outlet, socket, or switch in your home. You may need an additional device to bridge between electrical phases, but you can easily tap into the Insteon network anywhere there is a power supply in your home.
The biggest benefit is the redundancy the system provides. If wireless is down or there is some sort of interference, the system easily changes to powerline communications and vice-versa. Unfortunately, if the power goes out then you lose both forms of communication, but you’ll also lose power to your accessories so nothing works anyway.
Another benefit is that you don’t have to run new cables since the Insteon protocol includes powerline connectivity. It uses your existing electrical wires to pass messages. There is no need to open walls or snake wires through existing construction.
While Insteon makes hundreds of different accessories for their network, one big drawback is the lack of third-party options. Some do exist, but for the most part you are locked into the Insteon ecosystem. If the company goes out of business then you won’t have much opportunity to grow or upgrade.
Insteon makes its own hubs and associated smart home accessories. Read our review of the Insteon Hub for more information.
X10 is a wired home automation protocol that uses your existing electrical wires to send and receive commands — it is a powerline technology. The protocol was developed in 1975 by Pico Electronics and remains in use today, although the technology has not advanced to keep up with newer systems.
Commands are sent across existing AC electrical wiring in bursts, which are small packets of data that provide identifiers and commands. Early X10 devices were one-way communicators — they were only capable of receiving commands. More advanced (and more expensive) accessories can receive commands and also respond with a status message.
You can only install 16 accessories per house code, but there are 16 house codes available so the theoretical system limit is 256 accessories. You will have to install a filter to keep commands from other homes on the power grid from controlling your devices.
X10 is easily added to existing homes without the need for additional communications wiring. In addition, it is more reliable than wireless technology and can communicate to any location that has an electrical outlet, socket, or switch. The technology is also relatively inexpensive and easy to install so if you just want a few simple light controls then X10 may be an option.
Radio transmitters have been developed for X10 so you can have remote control from within your home. In addition, there are some X10 controllers that connect to the internet to give you control from outside your home.
The X10 protocol has not kept up with other technological advances so there are some drawbacks. First, internet-based control requires more advanced setups and isn’t as easy to use as newer technology. In addition, X10 occasionally experiences interference from noise on the AC wave. While X10 can work across multiple electrical phases, extra components are required for this.
We recommend that you only purchase an X10 controller if you already have X10 accessories and need to replace your current controller. If you are starting a home automation system from scratch, then we suggest looking at the other protocols above because they offer more advanced features.
If you already have a local X10 system and you want to add remote/internet control, check out the Universal Devices ISY994ix (Amazon or Smarthome.com), but keep in mind that this requires some advanced setup.
Universal Powerline Bus (UPB)
UPB is an acronym for Universal Powerline Bus, which is a home automation protocol that sends communications over existing AC electrical cables in your home. UPB is developed by California-based Powerline Control Systems. The company sells commercial and residential lighting control systems.
The wired system communicates via pulses within the alternating current on standard electrical wiring. It is similar to the X10 technology, but is considered to be more efficient and more reliable. The intent was for UPB to replace X10, but the technology hasn’t caught on and there aren’t many devices on the market.
The main benefit of UPB is that it can easily be added to a home without the need for new wiring. In addition, it is very reliable (up to 99%) and reaches anywhere in the home that has a power outlet, light, or switch. Devices communicate peer-to-peer so a central controller isn’t necessary. The technology can also be set up to work on both phases of an electrical system.
Unfortunately, there are a number of significant disadvantages. First, it is very complicated to set up a wireless controller that connects to UPB so remote or phone-based control is not available. In addition, there aren’t a lot of product options available. While the powerline reliability is positive, we simply cannot recommend UPB in an era where more advanced protocols are available.
All of the lighting control devices communicate peer-to-peer so a central hub isn’t required. If you are interested in UPB for lighting control in your home, check out Pulseworx by Powerline Control Systems.