Zigbee vs. Z-Wave | What Are The Differences?

The buzz around smart homes and home automation is greater than ever, thanks to the wide availability of affordable hardware and a plethora of connectivity options to choose from. One simple example of this is a “smart” light bulb that can turn on or off, change colors, or adjust brightness with just a few voice commands. Such smart devices support a variety of short-range wireless or Internet of Things (IoT) protocols. If you’re in the process of transitioning to a smart home, you’ll frequently encounter two wireless communication protocols: Zigbee and Z-Wave.

Both these wireless connectivity technologies play a huge role in home automation. However, things can get a bit confusing when choosing between Zigbee and Z-Wave. There are a lot of parameters that can have a huge impact in deciding between Zigbee and Z-Wave such as the country you live in, range (distance) of operation, number of devices, power consumption, and many more.

In this guide, we will look at the basics of these protocols, their pros and cons, and some key differences. There is a new player in town in the form of ‘Matter’. For the sake of this comparison, let us focus only on the two popular home automation protocols right now.

What Is Zigbee?

Zigbee is a relatively new communication protocol (compared to Bluetooth and Wi-Fi) that is based on IEEE 802.15.4 specifications. Developed and maintained by Connectivity Standards Alliance (previously known as Zigbee Alliance), Zigbee is a low-power, open-standard, and cost-effective protocol for wireless communication between smart devices. As a result, Zigbee became hugely popular in battery-operated wireless control and monitoring applications.

The frequency of Zigbee communication is the very popular 2.4 GHz band in the unlicensed ISM (Industrial, Scientific, and Medical) spectrum. While some commercial applications and medical devices use sub-GHz frequencies (915 GHz in the United States and 868 MHz in Europe), the majority of the ‘smart’ and ‘IoT’ devices for home usage use 2.4 GHz worldwide.

In order to achieve low cost and low power consumption, the Zigbee protocol works at a very low data rate of 250 kbps.

How Does Zigbee Work?

At the core of Zigbee lies its network structure, which consists of three primary components: Zigbee Coordinator, Zigbee Router, and Zigbee End Device. One of Zigbee’s standout features is that the network layer supports star, tree, and mesh topologies. In a star topology, the Zigbee Coordinator controls the entire network. All other devices (which are Zigbee End Devices) communicate directly with the coordinator.

In tree and mesh networks, the coordinator is responsible for starting the network and managing some key network information such as routing tables. In tree networks, the Zigbee Router extends the network’s range by passing data between devices and the Zigbee Coordinator for communication over larger distances. Zigbee mesh network supports peer-to-peer communication. Each device can communicate with multiple other devices, creating a web of connections. If one device fails or encounters interference, the data can reroute through another device. ZigBee devices relay messages to each other through multiple wireless hops.

What Is Z-Wave?

Z-Wave is a very popular wireless communication protocol that is designed and developed specifically for home automation (control and monitoring). Some well-known applications of Z-Wave are lighting control, climate control, smoke detectors, smart electric meters, etc. Zensys originally developed Z-Wave but Silicon Labs now owns everything associated with that tech and branding.

It is a low-power, proprietary, and low-latency protocol with data transmission rates up to 100 kbps. The frequency of operation of Z-Wave is quite unique. Unlike other wireless protocols (Wi-Fi or Zigbee) that use a particular RF band everywhere, Z-Wave frequencies are region-specific. But nonetheless, they all are sub-GHz.

For instance, Z-Wave operates at a frequency of 908.42 MHz in the U.S. and at 868.42 MHz in Europe. This means devices meant/designed for a particular region might not work with devices in other regions.

How Z-Wave Works?

Z-Wave is a two-way wireless communication with a mesh topology. A typical Z-Wave network consists of two types of nodes: Controller and Slaves. In most wireless networks, the controller has a direct connection to all the other nodes. If a node is out of range of the controller or if there is any disturbance in the path of communication, the controller cannot reach that node by any other means.

However, Z-Wave overcomes this limitation with the help of its mesh topology. Even if the controller cannot communicate with a particular node, other nodes can forward and repeat the message and deliver it to the final node. Z-Wave communication can route messages via up to four repeating nodes.

The Controller frequently updates its routing tables based on the information received from the nodes and their neighbors. It uses this data for possible future communication.

Zigbee vs. Z-Wave: Differences

Frequency

The first significant difference between Zigbee and Z-Wave protocols is their frequency of operation. Both technologies use a part of the unlicensed ISM spectrum. Zigbee operates in the widely popular 2.4 GHz band. If you are familiar with this particular frequency, you’ll know that both Wi-Fi and Bluetooth also use the same frequency (even your microwave oven uses the same frequency to heat food).

Some medical and commercial devices operate at sub-GHz frequency with Zigbee protocol and the frequencies are region-specific. For instance, sub-GHz Zigbee devices in the United States use 915 MHz while devices in Europe use 868 MHz. Regular smart home devices operate at 2.4 GHz though.

On the contrary, Z-Wave protocol primarily operates at a frequency lower than 1 GHz (commonly known as sub-GHz bands). These frequencies are highly geo-restrictive and every country/region has a separate operating frequency. USA and Canada use 908.42 MHz while European countries use 868.42 MHz. As a result, Z-Wave devices are highly region-specific.

Signal Range

The frequency of operation has a huge impact on the range of the signal as well as interference. Let us start with the range. Zigbee devices that operate at the standard 2.4 GHz have a transmission range of 10 to 20 m indoors. The actual range depends on several factors such as the material of construction (bricks, wood, etc.), objects blocking the signal, power of the transmitter, number of walls in between, and many more.

In Z-Wave protocol, the communication distance between two indoor nodes can be anywhere between 50 to 70m. If the two devices are in a direct line-of-sight path, then the distance between them can be in the range of 100 to 200m.

Realistically speaking, Zigbee communication is suitable for up to 10m while Z-Wave up to 50m.

Interference

Another frequency-related parameter that has a huge impact on the operation of Zigbee and Z-Wave is interference with other wireless protocols. Zigbee protocol operates in the same frequency band as Bluetooth and Wi-Fi i.e., 2.4 GHz. The threat from Zigbee to Wi-Fi and vice versa is much more significant than from Zigbee to Bluetooth or the other way.

Interference occurs when an RF receiver receives multiple differently modulated signals that operate at the same or close frequency (Zigbee and Wi-Fi in this case). Interference from Wi-Fi networks can significantly diminish Zigbee’s performance such as delayed responses, packet loss, or even complete communication failures in a Zigbee network.

When a Wi-Fi router transmits data, it can drown out weaker Zigbee signals. This can result in packet losses for Zigbee devices. Conversely, Zigbee transmissions can create noise in the 2.4 GHz band that might reduce the efficiency of Wi-Fi communication.

Unlike Zigbee and Wi-Fi, Z-Wave operates in the sub-GHz frequency bands. The main reason to choose this frequency range is to minimize interference with other wireless technologies, especially in the crowded 2.4GHz band. However, Z-Wave still faces its own set of interference issues.

One primary interference source for Z-Wave comes from other devices operating in the same sub-GHz frequency band. These devices include baby monitors, cordless phones, and certain security systems. When these devices operate near Z-Wave networks, they can emit signals that interfere with Z-Wave communication.

Security

With an increasing number of devices connecting to the internet, the data security aspect of the communication protocol is of utmost importance. For securing the network, Zigbee uses the AES-128 standard. It is a block cipher that encrypts and decrypts data packets so that listening nodes without a key cannot understand the message.

In addition to encryption, Zigbee also uses authentication (network keys and device-specific keys) to further improve security. The network key secures all communication within the Zigbee network, while each device also uses a unique link key to communicate securely with the network coordinator. Thanks to this dual-key system, even if an attacker gains access to one key, they cannot easily compromise the entire network.

Like Zigbee, Z-Wave also uses AES-128 encryption to secure communication between devices. Additionally, Z-Wave employs a security framework known as Z-Wave S2. The S2 framework includes several critical security features, one of them being secure key exchange (which prevents unauthorized devices from joining the network).

While joining a network, devices use a QR code or a unique PIN for authentication. For instance, when adding a new Z-Wave thermostat to a smart home system, the user must authenticate the device using the S2 protocol.

Another important feature of the S2 framework is secure command classes. These secure command classes prevent attackers from manipulating or spoofing commands. For example, S2 protocol’s secure command structure would prevent an attacker from attempting to unlock a Z-Wave door lock remotely.

Interoperability

Interoperability in a wireless communication protocol plays an important role in seamless communication between devices from different manufacturers.

The Connectivity Standards Alliance (CSA), manages the Zigbee protocol and sets guidelines (such as standardized profiles and device types) for manufacturers. When manufacturers follow these profiles, their devices can easily communicate with devices from other manufacturers that follow the same standards.

However, achieving interoperability in Zigbee was not always simple. Earlier, some manufacturers implemented proprietary extensions or features that deviated from the standard Zigbee profiles but still passed Zigbee’s certification process. These customizations allowed devices with ‘Zigbee’ branding to be released in the market which created problems with interoperability.

The introduction of Zigbee 3.0 unified all previous Zigbee profiles into a single standard for enhanced interoperability across different device types from different manufacturers. As of 2024, the CSA has certified over 4,000 Zigbee products from more than 400 companies.

Things are slightly less complicated in Z-Wave. The Z-Wave Alliance, which governs this ecosystem, has always set very strict standards that manufacturers must follow to achieve interoperability. These standards include defined device classes and command sets. As a result, a Z-Wave device from one manufacturer will effortlessly work with a Z-Wave Controller from a different manufacturer. Currently, Z-Wave has over 4,000 products from more than 700 manufacturers.

Speed

Data transfer speeds in a communication protocol play a significant role in determining the efficiency and responsiveness of smart home and IoT networks. Zigbee, designed for low-power, low-bandwidth communication, prioritizes reliability and energy efficiency over high-speed data transfer.

Zigbee operates at data transfer speeds of up to 250 kbps. This speed, though lower compared to protocols like Wi-Fi, is more than enough for a smart device to send a command to turn on or off, or a Zigbee sensor to transmit data about temperature or motion.

The data transfer speeds of Z-Wave are much slower than Zigbee. Z-Wave typically operates at data transfer speeds of up to 100 kbps. However, Z-Wave’s data transfer speeds vary depending on the specific version of the protocol and the environmental conditions of the network. The original Z-Wave protocol (known as Z-Wave Classic) operates at speeds of up to 40 kbps.

While this speed is sufficient for basic applications, the introduction of Z-Wave Plus and Z-Wave 700 significantly improved data transfer rates and overall network performance. Both Z-Wave Plus and Z-Wave 700 increased the speed to 100 kbps. They offer faster communication between devices and provide support for larger networks with more nodes.

Number Of Devices And Hops

At the time of writing this guide, Zigbee supports up to 65,000 devices while Z-Wave supports only 232 devices within a single network. The huge difference in the number of devices supported by Zigbee and Z-Wave is a result of the different addressing schemes these protocols employ. Zigbee uses 16-bit addressing while Z-Wave uses 8-bit addressing for its devices.

The high device capacity makes Zigbee particularly attractive for large-scale deployments (especially in commercial applications). While the device capacity in Z-Wave is less, it compensates for this with its reliable and consistent performance.

In the context of wireless communication, “hops” refer to the number of steps a signal takes to travel from its source to its destination. Both Zigbee and Z-Wave use hops to extend the range and improve the reliability of their networks.

While both Zigbee and Z-Waves use mesh networking topology, Zigbee networks support up to 15 hops but Z-Wave networks can handle only up to 4 hops. The advantage of the higher number of hops in Zigbee compared to Z-Wave is the Zigbee network can potentially cover a larger area than a Z-Wave network.

Power Usage And Battery Life

Both Zigbee and Z-Wave are known for their low-power operation. The Zigbee protocol is slightly better in this regard. Zigbee devices typically consume between 0.5 and 1.5 mW (milliwatts) during active communication. In the case of Z-Wave, the active state power consumption is between 1 and 2 mW. This low power usage is important for the longevity of battery-operated devices.

Zigbee and Z-wave operate in a low-duty-cycle mode, which means that devices transmit data intermittently rather than continuously. When a device is not actively transmitting or receiving data, it enters sleep mode. This sleep mode drastically reduces power consumption and extends battery life.

Open And Proprietary Standards

Zigbee operates as an open standard. This means that its specifications are publicly available and accessible to anyone. The CSA publishes the Zigbee specification, including the protocol’s communication methods, network architecture, and device interactions. Manufacturers and developers can create and integrate Zigbee devices without any restrictions and importantly without any royalty fee.

In contrast, Z-Wave is a closed and proprietary standard. The Z-Wave Alliance, which manages Z-Wave, doesn’t make its specifications openly available to the public. Instead, it controls access to the protocol through licensing agreements. Manufacturers must join the Z-Wave Alliance and follow their guidelines to develop and market Z-Wave products. This closed nature helps in maintaining consistent quality and interoperability across devices from different manufacturers.

Price

When comparing Zigbee and Z-Wave, price also plays a significant role. Zigbee devices tend to be more affordable compared to Z-Wave devices. The main reason for this price difference is that Zigbee is an open standard while Z-Wave has licensing fees and certification costs for manufacturers. This cost trickles down to the price of the product as well. For instance, Zigbee-compatible smart bulbs, sensors, and switches are often available at lower prices, starting around $10 to $15. Z-Wave smart bulbs and sensors typically start around $20 to $30.

In terms of network infrastructure, Zigbee hubs or coordinators are usually priced lower than their Z-Wave counterparts. You can find Zigbee hubs anywhere between $20 to $40, whereas Z-Wave hubs often cost between $50 and $100.

Zigbee vs. Z-Wave: Pros And Cons

Zigbee

Z-Wave

Zigbee vs. Z-Wave: Comparison Chart

Final Words

When it comes to smart homes, IoT devices, and home automation, the two wireless communication protocols i.e., Zigbee and Z-Wave are pretty much the only choices for homeowners (although Wi-Fi devices and a new protocol named Matter are starting to make some buzz nowadays). When it comes to Zigbee vs. Z-Wave, there is no clear winner and both these protocols have their fair share of advantages and disadvantages.

While Z-Wave devices are usually of high quality and stable out-of-the-box, they tend to be slightly costly. Zigbee devices are cheaper but might have interference issues with Wi-Fi networks or devices. Ultimately, you have to consider your country/region, budget, ease of implementation, battery life, and compatibility while making a decision.