Comparing IoT mesh network protocols: What’s the difference?

Zigbee is a standards-based wireless technology developed to enable low-cost, low-power wireless machine-to-machine and IoT networks. Silicon Laboratories Inc. acquired Ember, the creator of Zigbee, in 2012. Zigbee offers mature application layer support for home automation, lighting and metering, said Matt Maupin, senior product manager of wireless embedded systems at Silicon Labs.

The Thread protocol is a home automation communication method owned Bluetooth mesh, introduced in July 2017, was designed to address the specific requirements of commercial and industrial networks. Bluetooth mesh devices that support Bluetooth Low Energy can provide connectivity to the cloud via a tablet or smartphone.

Matt Maupin

“This, of course, is a temporary connection, as the devices would not be able to connect to the cloud to send or receive information if the phone or tablet isn’t present, requiring a gateway for an always connected experience,” Maupin said.

Zigbee requires a gateway to connect devices to the cloud, while Thread doesn’t need a full gateway because of its IP-based connectivity.

Z-Wave is a mesh protocol focused on command and control in the smart home, said Johan Pedersen, product marketing manager of Z-Wave IoT at Silicon Labs, which recently acquired Sigma Designs’ Z-Wave business. The protocol has its own consortium, the Z-Wave Alliance, made up of 700 companies that create products and services powered Z-Wave is a sub-1 GHz wireless mesh network specifically developed for smart home products, such as lights, door locks, security systems and heating control.

“Sub-1 GHz means that it runs at a different frequency than Bluetooth, Wi-Fi and Zigbee,” Pedersen said. “Sub-1 GHz has a longer range throughout the home than the higher-frequency ones that are typically at 2.4 GHz.”

Operating in the sub-1 GHz band also helps prevent interference, he said. The 2.4 GHz band is a crowded space. With fewer devices and products on sub-1 GHz, you’re less prone to wireless interference.

Johan Pedersen

“You do have other technologies in sub-1 GHz,” Pedersen said. “For example, Zigbee has a version that is sub-1 GHz, but there are very few products actually using it. There are tons of proprietary wireless protocols on sub-1 GHz, but not really mesh.”

In the market since the early 2000s, Z-Wave is interoperable, meaning all Z-Wave devices can speak to and understand each other.

“Interoperability and backward compatibility are two key features of the Z-Wave technology,” Pedersen said. “This is where there is a big difference between Z-Wave and the rest.”

So, what about Wi-Fi? Gartner analyst Mark Hung said that very early on, Wi-Fi supported mesh networking with 802.11s; however, because there was never a certification program for it from the Wi-Fi Alliance, it was not widely implemented or adopted. But there has been a renewed effort to allow Wi-Fi to implement mesh networking, but it’s not quite ready yet.

“It’s even less mature than Bluetooth 5,” Hung said. “I would say, though, it’s early stages. Don’t count Wi-Fi out just because of its install base.”