Zigbee is a wireless technology developed as an open global standard to address low-power, low-cost wireless IoT (Internet of Things) networks’ unique needs.
It is a protocol used to link smart devices such as plugs, locks, and lights to a home network.
We can also link our Zigbee network to a hub like SmartThings Hub. Here, SmartThings Hub serves as a “bridge” to the Internet, offering apps, cloud tools, and (remote) control from our phones.
However, Zigbee is similar but different from competing protocols like Wi-Fi, Bluetooth, and Z-Wave.
They all create relatively secure networks, which we can (mostly) connect to a hub and control with our phone or a desktop application.
How Does Zigbee Work?
Zigbee delivers low-latency communication. The chips are typically integrated with microcontrollers and radios. Zigbee devices communicate with each other using a radio transceiver.
Furthermore, every Zigbee device uses the same communication standard, with forward and backward compatibility.
Zigbee chips operate on the IEEE 802.15.4 protocol over 2.4 GHz, which we might recognize as the same band used by Bluetooth and Wi-Fi. Because Zigbee uses less power, it has a shorter indoor range of about 10-20 meters.
Zigbee builds on the media access control and physical layer defined in the IEEE standard 802.15.4 for low-rate WPANs (wireless personal area networks).
The specification includes four key components: application layer, network layer, manufacturer-defined application objects, and Zigbee Device Objects (ZDOs).
Zigbee Device Objects are responsible for some tasks, including managing requests to join a network, device discovery and security, and tracking device roles.
The Zigbee network layer natively supports tree and star networks and generic mesh networking.
Every network must have one coordinator device. Within star networks, the coordinator must be the central node.
Both trees and meshes allow Zigbee routers to extend communication at the network level.
- Zigbee devices are capable of connecting.
- Zigbee devices offer backward and forward software compatibility
- We don’t need multiple hubs to connect more devices
- Zigbee offers device-to-device communication
- Zigbee is a facility that protects the establishment and transport of cryptographic keys, carries out secure communications, and controls devices and cipher frames.
Mesh Network: A mesh network is fundamentally a network in which each device acts as a repeater. In a mesh network, rather than sending the signal back to the originator, the device repeats it and forwards it to all other network devices within range.
Mesh networking can be referred to as “self-healing networks.” With a standard Wi-Fi network, if our router goes offline, all devices also go offline.
Zigbee protocols automatically detect and remediate failures, outages, and breaches of all kinds, as well as “self-heal,” so devices continue to perform.
The network will re-route and stay up if another routing device is within range.
Different Types of Zigbee Devices
A Zigbee network consists of three device types: the Zigbee Coordinator (ZC), the Zigbee Router (ZR), and the Zigbee End Device (ZED).
All these devices play different roles in a Zigbee network. Let’s take a look at the various roles that the device types perform:
- Zigbee Coordinator (ZC): The ZC sets up the Zigbee network. The Zigbee Coordinator is responsible for bootstrapping the network and coordinating the network’s actions as a whole. We need one ZC per network, and the hub normally takes the role, for example, Philips Hue Bridge. As a user, your coordinator does not have to be a smart hub, but we recommend it. It serves as the central point to our network, where we can set permissions, allow other devices access, and coordinate our Personal Area Network (PAN).
- Zigbee Router (ZR): All Full Function Devices (FFD), powered, non-battery Zigbee devices, all act as routers to repeat the Zigbee signal unless configured to perform another function. This is the default configuration for most Zigbee smart plugs, lights, etc. We can say Routers are in charge of talking to all other devices in range on the network, and they “repeat” the network signal. It is like playing Telephone, except Zigbee is good at it. If our devices can “hear” each other, they’ll pass the message on perfectly.
- Zigbee End-Device (ZED): We can buy a battery-powered or reduced-function device to function as an end device. This device does not forward or repeat signals and is very simple to use. More importantly, these devices do not talk to each other. Reduced-function devices or end devices only talk to coordinators and repeaters. In most cases, all devices are full-function devices unless we choose battery-operated devices such as simple switches, wireless lights, etc.
Why Use Zigbee?
Zigbee is not the absolute best home automation technology. Like every other technology, it has pros and cons.
Nevertheless, it does have a lot to offer consumers.
- Better Remotes: If we have Infrared lights or RF at home, we will be pleased to know Zigbee is much easier and simpler to use. If we use a remote, we can point it anywhere to activate the connected device. Furthermore, I would recommend a smart hub because of its additional benefits. For example, a smart hub allows us to connect our Zigbee network to the web to use our phone as a remote. Using our phone as a remote will allow us to set up automation and control our devices when not at home.
- Secure: Like Z-Wave (Zigbee’s primary competitor), Zigbee uses 128-bit AES encryption keys. Using the 128-bit AES encryption keys plus short-range signals makes Zigbee more secure by default. On the other hand, most home automation protocols have similar levels of security when we configure them properly.
- Stable Networks: Zigbee devices re-route automatically when one device in the network goes off. Our network won’t go down because we accidentally physically turned the hallway light off unless that light is the single link between our network and the rest of the devices in the house.
- Device Interaction: One major feature of Zigbee is that all its devices can talk to other Zigbee devices with forward and backward compatibility. However, not all Zigbee devices are interoperable without a hub.
- Connect to the Cloud: Zigbee links to the Internet over a smart hub. With hubs, we can control devices with apps on mobile, cloud, or desktop devices. It also means setting up automation, collecting usage data, and the option to invite multiple users who will be able to control the same devices.
- Power-Efficient: Zigbee devices are known to be power-efficient because they use very little energy when on standby. This enables the device to reduce electric usage greatly and improves battery life where relevant.
- Multi-Device: With support for many devices on a single network, we will never need more than one Zigbee hub. If we only want a few devices, you may need a Zigbee repeater or a different protocol if you’re spreading your smart devices over an entire house.
- Cost-Effective: One of the additional benefits of Zigbee is that the devices are very affordable. Zigbee devices tend to be 21-50% cheaper than Z-Wave devices. However, if we buy a smart device that supports multiple protocols, we will see no real price difference.
Although Zigbee has a lot to offer to its users, at the same time, it also has some drawbacks or issues, and they include:
- Zigbee networks have a limited range if we don’t add more devices. So, one device must always be within 10-20 feet of another.
- We always need a hub like Homey to pair Zigbee to our computer or mobile phone.
- One of Zigbee’s drawbacks is that not every smart device supports it. While Zigbee dominates the smart light market, we will likely need another technology if we want switches, sensors, or data streaming devices.
