Z Wave vs. Zigbee | Which is Best for Smart Homes?

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Gained early experience with automation technology in the private and industrial sector, can turn his living room into a movie theater with one voice command and is the owner of this website. He is happy to share his accumulated experience with every new article.

Z Wave

Z Wave wireless technology has been developed since 2001 specifically for smart homes, and thus the automation for houses and apartments. The current series has a range of almost 100 meters and all thanks to the frequencies used, which are around 900 MHz.

Because these frequencies do not overlap with the also frequently used Wi-Fi frequencies, Z Wave is relatively interference-free. The data transmission speed is between 9.6 and 100 Kbit/s. A good 700 companies have adapted their 2,400 products to Z Wave radio technology. They guarantee that all devices can operate with each other in any case.

ZigBee

The ZigBee radio standard has been around since 2002 – almost as long as Z Wave. Originally, this term was used to describe several radio profiles in the same frequency ranges.

However, since they were used for completely different areas at the time, they did not interfere with each other and were also not compatible with each other. Finally, everything changed completely with ZigBee 3.0 in 2016. All radio profiles were combined into one standard. This makes all the manufacturers’ devices compatible with each other.

Because the radio standard has been using the so-called “energy harvesting” principle from EnOceans since that time, the devices are much more energy efficient. By pressing a switch or other source, the energy needed for the transmission of data is thereby obtained from the direct environment. The batteries in the devices therefore have a long runtime.

Incidentally, as many devices as are needed can be integrated into the entire ZigBee system. If the original range is not sufficient, it can be increased with additional hubs. The radio standard operates at a frequency of 2.4 GHz and has a range of between ten and a maximum of 75 meters. Because the same frequency is also used for the popular and thus widespread Wi-Fi, it is relatively easy for device manufacturers to implement.

Therefore, the devices that use ZigBee as a radio standard are relatively cheap to develop. Unfortunately, the signal can already be disturbed by raindrops, for example. On the other hand, the data transmission speed is relatively high at up to 250 Kbps.

Z Wave vs. ZigBee – Similarities and Differences

Both wireless standards have a lot in common. For example, both use the same security profile, AES-128 encryption. Both also use a mesh network.

Since manufacturers use standards across the board for both Z Wave and ZigBee, both networks seem equally well suited for any smart home. However, this is not entirely true. In order to make an informed decision for or against one of the two wireless standards, here are the differences once again:

ZigBee: If Z Wave and ZigBee are compared directly, ZigBee is faster thanks to the higher transmission rate and operates more energy-efficiently. Because the number of hubs can be increased indefinitely, the system can be expanded to any size.
Even though significantly fewer manufacturers produce devices with the ZigBee wireless standard, the entire portfolio of products offered is sufficient to adequately supply a smart home. The connections between the devices are more susceptible to interference, but the frequency used for WiFi at the same time ensures lower prices. ZigBee is particularly used in the field of smart lighting, for example in the Hue lighting system from Philips.

Z Wave: The Z Wave radio standard provides a stable signal even when the spatial conditions are rather unfavorable and complex. This is due to the greater range of the standard. Because rather simple and therefore short commands and thus only a relatively small amount of data have to be transmitted in the private smart home sector, the somewhat lower transmission rate hardly has an impact.
On the other hand, a maximum of four hubs can be integrated in the Z Wave. This is usually sufficient for a private smart home. Numerous companies manufacture their products for the Z Wave radio standard. However, while only the newer devices from 2016 are compatible with ZigBee, older versions can also be used with Z Wave.

A brief direct comparison: ZigBee is suitable as a wireless standard when it is important that many products are used and the network can be expanded as required. ZigBee is also much more energy-efficient. For the Z Wave standard, on the other hand, there is more choice among manufacturers.
Because the entire Z Wave system is less susceptible to interference, it runs more stable overall and has a greater range. If devices already run with one of the two wireless standards, it is usually easiest to stick with it.

This is what you should look for in wireless standards for smart homes

If devices are used in the smart home, they must transmit data. This is done by radio and should consume as little energy as possible. Because W-LAN ensures fast data transmission but requires a lot of energy, this standard has not become established in the smart home sector.

Instead, standards are used where only small amounts of data need to be sent from the sensors. These include Z Wave and ZigBee. Because these standards are freely accessible and open to manufacturers, they can use them to produce their products.

Stable connections are what counts

Stable connections are essential for the smart home. Only then can the individual devices exchange their data and communicate with each other without interference. This applies to the connection from the cell phone to the Internet, and it also applies to data transmission in the smart home. Smart home systems generally use low-frequency electromagnetic waves to exchange data.

These are modulated in such a way that information can be transmitted via them. The frequencies used for radio are allocated by the German Federal Network Agency. The standards in the smart home sector use the Industrial, Scientific and Medical Band (ISM band), which uses the range between 2.4 and 2.5 gigahertz, or the Short Range Device (SRD band) between 863 and 87o megahertz. In order for the individual devices to be controlled directly with the tablet or smartphone, the radio frequency used for this purpose must be converted into a W-LAN signal. Most smart home systems require a control center for this, also known as a gateway or radio bridge, which is connected to the W-LAN router.

Open and closed radio standards

Both Z Wave and ZigBee use an open radio standard. This means that the technology on which they are based is accessible and freely usable by all manufacturers. There are often several companies in which the necessary protocols are jointly developed.

In a closed radio standard, also known as a proprietary radio standard, the protocol is developed by a single manufacturer and used for its own products. This means that the data can be transmitted much more securely.

However, users are then bound to the products of the respective manufacturer, unless they use the Alexa app or other apps as a connection. Because each individual manufacturer can also change the protocol in an open wireless standard, the devices are not compatible with each other in exceptional cases.

Connecting the different radio standards with each other

If the system used in the smart home is set up openly, completely different wireless standards can also be connected and used with each other. This is why the Homee or Magenta control centers have integrated the different standards.

However, the same also works with the apps from Alexa, Google Assistant, Apple HomeKit, iHaus or IFTTT. A central app evaluates the information sent and translates it for the respective devices and sensors. The only requirement is that the app used and the devices connected to it are compatible with each other.

Or would you rather have a smart home with a bus system?

If a house is newly built or a smart home system is retrofitted in an old building, the control system can also be transmitted by cable. For this purpose, either the existing power cables can be used via a powerline system, or a second cable system is installed parallel to the power line.

This is made possible by a bus system that is independent of the power line, a so-called KNX system. Both systems integrate any number of devices from different manufacturers into a smart home system and can be combined with Ethernet or Powerline.

With the KNX system, even radio-based and wired devices can be controlled via the same interface and a wired smart home can be easily expanded in this way. The radio standard used for this is called KNX-RF.

How Does ZigBee Work?

ZigBee uses a radio protocol that is structured in several layers. Each layer takes over a specific task in the communication. One layer physically transmits the signals, another encrypts the data, a third ensures that there is no data congestion, and so on.

While the user himself only acts with the upper layer, the others do their work in the background. In the upper two layers, ZigBee uses the same IEE standard as BlueTooth and the ISM band with 2.4 GHz. Each of the 16 channels has a total of two MHz. Long pauses are used when transmitting data. Because each individual node falls into a sleep mode during this process, ZigBee saves a lot of energy.

Thus, a small battery in a sensor usually lasts for several years. ZigBee communication is defined in the corresponding specification. The individual devices that work with the ZigBee standard communicate with each other in a wireless personal area network that can be uniquely identified by means of a 64-bit address.

The WLAN from ZigBee

In each ZigBee network, the individual end devices are connected to the routers and communicate only with the one assigned to them. Because they are in sleep mode most of the time, they only need an infinitesimal amount of energy. They connect to their router at regularly timed intervals and check whether there is any information for them there.

The routers themselves transmit the data and exchange it with each other. In addition, there is a coordinator in the network, a special router that can activate the entire network. For the actions, the networks can be connected via the mesh topology, but also the tree or star topology. In the star topology, the coordinator is located in the center.

All communication runs via this central point. If it fails, the entire network is idle because the end devices cannot communicate with each other. If the network is set up in the tree topology, there is a central coordinator. This communicates with the respective few routers, and these in turn with the end devices assigned to them.

The mesh topology additionally networks the routers with each other. Therefore, the communication and data transmission between the individual nodes can run over many paths. Most smart homes that use the ZigBee wireless standard are therefore networked together in the mesh topology, which enables up to 65,000 nodes.

ZigBee Hub, Gateway or Bridge

Hub, gateway or bridge refers to the bridge that exists between the control app on the tablet or smartphone between the devices. This is where the required data is transferred. Some hubs can even control the devices of other manufacturers, provided they work with the ZigBee protocol. The Tradfri bulbs from Ikea can therefore communicate with the Hue Bridge from Philips*.

If this can be used, a second hub is largely unnecessary. Devices that work with the ZigBee standard cannot easily be paired with devices that use the Z Wave, BlueTooth or WLAN standard. You need a special translator between the individual radio standards for this. If this is available, routines can also be created with Google Home products and thus address the smart home light bulbs from Philips.

ZigBee with sufficient range

The individual products offered by the various manufacturers for the smart home usually have a range of ten to fifteen meters. If they are connected to each other in a mesh protocol, the range can thus be significantly increased.

Each individual device acts as a repeater, thus amplifying the signal and forming a so-called node in the network. In this way, the range can be increased to up to 100 meters.

ZigBee 3.0 is the current standard

ZigBee as such is the actual main protocol. There were and are different specifications of this. Besides the actual standard ZigBee, ZigBee Pro from 2007 has more options in terms of topology. At the same time, security has been significantly improved.

ZigBee Green Power enables sensors that can, in principle, operate autonomously thanks to energy harvesting. Remote controls for controlling individual electrical devices use Radio Frequency for Consumer Electronics, abbreviated as RF4CE. ZigBee IP is responsible for the communication of the smart home and the Internet. Each individual ZigBee specification is made up of several modules, which can differ significantly from each other according to their use.

Therefore, in the past, the devices were often not compatible with each other, although in principle they used the same standard with ZigBee. With ZigBee 3.0, a radio standard was finally developed that combines the individual specifications Pro, Green Power, IP and RF4CE. This makes the devices more compatible with each other.

The security of the data is guaranteed with ZigBee by a secure transmission. For transmission, the standard uses symmetrical AES encryption with a data length of 128 bits. Nevertheless, attackers managed to access the network of Philips’ Hue lights via a bridge. The manufacturer quickly closed the security gap in the next update.

The advantages and disadvantages of ZigBee

ZigBee has significant advantages as a smart home standard:

Energy efficiency: Because both the sensors and the other devices in the smart home consume very little energy, the batteries used generally last for many years.
Open Source Code: The code of ZigBee is a so-called open source code. Every manufacturer can simply use it and, if they want to, program additional functions and implement them additionally in their products.
Compatibility: As of the ZigBee 3.0 standard, the products of all manufacturers that use ZigBee are compatible with each other. Among the manufacturers that rely on this standard are, for example, Ikea, Osram, Signify and Belkin.
Range: If the routers are connected in a mesh topology, the nodes serve as repeaters and amplify the signal. Therefore, the range is especially large in large and cluttered apartments and houses and is significantly better than a W-LAN network.

However, ZigBee also has some disadvantages:

Compatibility: If older devices are used with this open source code, they are not necessarily compatible with each other. However, this only affects those devices that were already on the market before the ZigBee 3.0 standard.

If other devices use other wireless standards, a gateway is required for networking. The devices can be controlled via Amazon Alexa, Apple HomeKit and Google Smart Home. This works with Alexa via Echo* or Echo Show 8*, both have a so-called Smart Home Hub, with which the devices can be controlled by ZigBee.

Alexa searches for all end devices responsible for the smart home with the command “Discover my devices”. In contrast, Google Smart Home products cannot be connected directly to devices that communicate via ZigBee. For that, a special gateway like the Philips Hue Bridge or the Samsung SmartThings Hub is needed. Once everything is linked and set up, the smart sockets can also be switched off and on with the help of Google Assistant.

Apple HomeKit products can only be connected directly to smart home devices that can be addressed via BlueTooth or WLAN. If you want to connect other devices, you also need a compatible gateway, such as the Homee smart home control center.

How Does Z Wave Work?

The basis of Z Wave is a wireless network that uses the same frequencies as radio frequencies. The protocol of Z Wave can be installed both in business premises, but also in residential premises and turns a house into a so-called smart home.

Different electronic devices can communicate with each other using the Z Wave protocol. This makes the operation of all devices more convenient, they can be switched on and off directly with a smartphone or tablet. The security of devices based on Z Wave is high, and at the same time they work energy-efficiently.

Meanwhile, Z Wave-based products have sold more than 100 million products around the world. This makes Z Wave the leader in smart home technology.

That exactly is Z Wave

Z Wave is a protocol that allows different devices in the smart home to communicate with each other. The low-energy radio waves are used to transmit the data, in a network all devices are connected with each other.

Both household appliances, but also garage doors, security systems, locks, lights, thermostats and many other devices can be controlled wirelessly with it. Originally developed by a company from Denmark, Z Wave came onto the market in 2004 to control simple devices. The biggest competitor in the smart home sector is ZigBee.

The technology of Z Wave

A so-called mesh topology is used to network the devices with each other. This is a decentralized network with up to 232 individual nodes. These are addressed with the frequency of 868.42 megahertz. A central controller is required for central control of the network.

Every device that works with the Z Wave protocol and is integrated in the network can also be controlled by Z Wave. Each Z Wave network has a corresponding ID that can be used to identify it. This identifies all nodes in the network together. The ID is four bytes long. The central controller assigns each device its corresponding ID as soon as it is logged onto the network for the first time. With the help of the system, the paths of all devices can be reliably and completely traced.

The central controller is used for authentication. The individual devices can use intermediate nodes and thus set up direct paths. If the individual nodes used in this process are not in direct order, the protocol uses other routes. Therefore, a network based on Z Wave can cover a much larger area than just the range of a single device.

However, the devices must be active at all times for this. For this reason, devices powered by batteries are not suitable as repeaters in this network for communication. In a single Z Wave based network, up to 232 devices can be interconnected. If even more devices are needed, multiple networks can be formed and interconnected.

Z Wave to control the smart home

With the help of the Z Wave protocol, simple household appliances such as thermostats, but also lights or door locks, can be intelligently controlled directly by radio. They can communicate with each other and perform all the functions that the respective user wants. The connections are secure and wireless.

The control and monitoring can be done from any location via tablet, smartphone or computer. As soon as the user enters a command on the tablet, the Z Wave technology receives it and forwards it to the corresponding device.

Application example: If the door to the garage is a smart garage door with Z Wave technology, the user can initiate the closing of the door via app on the tablet. As long as the user is connected to the Internet via tablet, it does not matter where they actually are.
The tablet registers the command and sends it to the garage door via the network. When the door is closed, it sends a notification back to the tablet. This lets the user know that his command has been executed. If existing devices are to be incorporated into the Z Wave network, they must have integrated 2-way communication.

The advantages of Z Wave

One of the main advantages is the connectivity of the system. Once a product can work with the Z Wave protocol, it is possible to network it with any other device that also works with the Z Wave protocol. And this is completely independent of the version used, the year of manufacture and the manufacturer itself.

Because the Z Wave protocol uses a completely different frequency than the other smart home protocols, there is no interference with the other protocols. For example, while W-LAN, BlueTooth and ZigBee use the same frequencies, Z Wave is on a different frequency.

This means that communication within the network is fast and immediate, with no delays. Thanks to the mesh topology, the individual nodes in the network are directly connected to many other nodes. All devices can thus communicate directly with each other and exchange their data directly and efficiently.

Because each individual node is in the same hierarchy as the others in the network, communication can seek its own paths and information does not always have to be forwarded via the same route. Thanks to the intelligent topology, the network configures itself. If a new device is to be added to the network, this makes installation easy.

As more devices are added to the network, Z Wave’s signal becomes stronger. This also increases the range of Z Wave. Some devices even act as amplifiers. If they become active in the network, they can amplify the signals of the devices among themselves, but also to the hub.

Low-power RF technology is used for this technology. This supports networks without a central coordinator. Because the devices themselves consume very little energy to communicate with each other, the electricity bill also remains manageable. The entire connection is made via radio; no cables are required.

Because Z Wave uses AES-128, the communication between the devices is very secure. AES-128 is an encryption that is also used by the US government, for example, because it is very difficult to decode again. Because Z Wave is easy to install and the individual components are relatively inexpensive, Z Wave has become the market leader in the smart home sector.

The disadvantages of Z Wave

As many advantages as Z Wave has, there are definitely some disadvantages. If a large range is required for the network, many individual devices must be connected to each other in the network. Otherwise, the range is quite limited.

The more devices or routers that have to be integrated to raise the signal to the required strength, the higher the costs for the entire network become. However, the maximum number of nodes supported by Z Wave is only 232, which is considerably less than is possible with ZigBee.

The speed of data transfer in the Z Wave system is just 100 Kbps. This is also relatively low, at least when compared to the performance of some competitors. Nevertheless, the speed is sufficient to control and monitor the devices in the smart home.

The development of Z Wave

Originally, Z Wave was developed by Zensys in 2001. The company originated in Denmark, with headquarters in Copenhagen, and that year introduced a system for controlling light. This eventually became Z Wave. The protocol has been developed further and further.

Thanks to its good radio range, improved battery life and memory, it was used by several companies, including Ingesoll-Rand, Leviton Manufacturing and, most notably, Danfoss, starting in 2005. It was also during this time that the Z Wave Alliance was formed.

A year later, Intel Capital joined the Z Wave alliance and invested in Zensys, as did Cisco System, Panasonic, Palamon Capital Partners and Sunstone Capital. Sigma Designs finally acquired Z Wave in December 2008, and ten years later Z Wave was sold to Silicon Labs.

While the Z Wave technology was used by just six products at the beginning, seven years later it was already used by a hundred times that number, i.e. 600 products. And in May 2017, there were already more than 1,700 products. Since then, the number of devices using the Z Wave wireless standard has continued to grow.

Are there other alternatives to Z Wave?

The oldest protocol for home automation is the X10, developed in the mid-1970s. This uses the power network used in the house, known as Powerline. Later it also used radio for data transmission.

However, X10 is slow for one thing, nor does it allow the individual devices to communicate with each other. On top of that, X10 is complicated to install. Another alternative is Universal Powerline Bus, a communication protocol that uses the powerline.

It has a stronger signal than X10 and uses the existing electrical line to transmit the data. However, this system is also relatively expensive and is difficult to install.

Z Wave vs. ZigBee: Which is the best system for smart homes?

As always, the best answer in this case is: it depends. If there are already installed devices, it certainly makes sense to stay with the existing technology and expand it.

However, there are also systems that can use both Z Wave and ZigBee. The best examples are the Home Base from QIVICON and the Smart Things Hub from Samsung. Otherwise, it depends on what is actually needed and therefore makes sense. Comparing Z Wave with ZigBee, ZigBee has a faster transmission rate and works much more energy efficient.

ZigBee can be extended further and further and does not set any limits. Even though fewer companies use ZigBee as a wireless standard, they produce significantly more products with this standard. Thanks to the 2.4 gigahertz frequency used, the development of the devices is cheap, as is the price, after all. Even though the connections can be more easily disturbed, the ZigBee standard is perfectly suited for smart lighting. For example, Philips’ Hue system uses the ZigBee standard.

Z Wave delivers a stable signal that functions reliably even over long ranges and complex room structures. Because only simple signals are usually transmitted in the private smart home, the lower transmission rate is also sufficient for this, as are the maximum possible four hubs. Many companies produce for Z Wave. This means that about as many products are available with this standard as with ZigBee. For the smart home, there are corresponding products for every area. This concerns sensors and hubs, but also heating, security or light. The Z Wave radio standard allows the newer devices to be connected to older devices as well. They are compatible with each other.

Attention: When installing electronic equipment, please be sure to observe the manufacturer’s safety instructions. You have to take care of your own safety. The information on this site only helps you to learn.
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