If you’re shopping for your first smart home device, you need to start evaluating communications standards. You might have read about Zigbee versus Z-Wave, Z-Wave versus Wi-Fi and Wi-Fi compared to Bluetooth. You might have read about smart home interference issues, or security and privacy concerns. Here’s a list of the pros and cons to help you start your search to fill your smart home need:
In 2005, the Z-Wave Alliance was formed by manufacturers seeking compatibility. The Z-Wave Alliance focuses on device compatibility, so no matter the who, what, when and where of your purchase, Z-Wave devices will play well together.
Pros of Z-Wave:
- Compatibility: As a private protocol, the Z-Wave Alliance has been able to ensure that practically all Z-Wave devices are intercompatible. The largest amount of manufactures uses the Z-Wave protocol. All told, there are over 1,500 Z-Wave different products on the market.
- Interference: Z-Wave operates on its own frequency, meaning that interference is virtually nonexistent.
- Range: Z-Wave is also a mesh protocol, so the more Z-Wave products you have, the greater their range. Each individual Z-Wave device has a theoretical range of 100ft.
- Security: Uses AES-128 symmetric encryption, the same as offered by some online banks, to safeguard communications
- Flexibility: Z-Wave devices use lower power than WiFi, and thus can be used in battery based devices
Cons of Z-Wave:
- Hub-based: Z-Wave devices need a hub to collect and manage their communication within the household and to the cloud.
Along with Z-Wave, this is one of the most popular wireless standards in the world today. Zigbee started in 1998 but didn’t become standardized until 2003. Its name is derived from a honeybee dance.
Pros of Zigbee:
- Flexibility: Zigbee can operate on two bandwidths, one slower bandwidth optimized for lower power consumption and another bandwidth that allows for higher data rates.
- Range: Zigbee is a mesh network, similar to Z-Wave. However, each Zigbee device has a theoretical range of only 35ft.
- Security: Can also use 128 bit encryption.
Cons of Zigbee:
- Interference: Zigbee’s high bandwidth frequency, which is its most common used, overlaps with WiFi and 2.4GhZ cordless phones, increasing potential interference.
- Scale: Zigbee originally only controlled lighting devices, and thus achieved less scale than competing frequencies like Z-Wave which powered different types of smart home devices.
- Compatibility: Because it is a open standard based on the IEEE 802.15.4, there is no governing body that can ensure interoperability. Thus, older Zigbee devices tend to have problems working with newer devices.
Even if you haven’t purchased any smart home devices, you probably already have Bluetooth devices.
Pros of Bluetooth:
- Long Battery Life: Bluetooth devices are in sleep mode until activated, leading to longer battery life.
- Simplicity: Bluetooth has been around for along time, and newer devices tend to still be compatible with legacy devices.
Cons of Bluetooth:
- Interference: The 2.4GHz frequency strikes again. The more Bluetooth devices you have, the greater chance of interference.
- Availability: Bluetooth is a more recent entry into the smart home device market and many hub units do not support this protocol.
- Security: Bluetooth was designed to be easy to connect to and relatively quick for battery based devices (like headphones and cellphones for music streaming). Because the consequence of hacking these early devices had low consequence, this standard never took security as seriously as other protocols like Z-Wave or Zigbee.
Of course, you always have the option of using Wi-Fi to connect your smart home devices.
Pros of Wi-Fi:
- Cost: When it comes to value for dollar, the prevalence of WiFi keeps the cost of antennas for WiFi based devices very competitive.
- Bandwidth: If you need to transmit a lot of data, like a video stream, cellular and broadband-based WiFi are your only options.
Cons of Wi-Fi:
Interference: Urban Wi-Fi users already know their internet suffers from interference. Wi-Fi uses the dreaded 2.4GHz and the more devices you have, the greater the risk of interference.
- Battery Life: Wi-Fi is a power-hungry protocol, so it’s very rare to find a battery based device. When there is one, it tends to shut down completely before waking up to communicate, hence causing a delay in the device’s performance.
- Security: while WiFi has security protocols available, they have a long list of problems and people tend not to use them. WiFi, like bluetooth, was also designed for things like speed and ease of use, so security is not core of what it does well.
Ultimately, there’s no one best protocol. Rather, you need to evaluate the pros and cons of each to find which works best for you.