However, most of these networks also need a "primary" device that serves as a network controller. If the primary device drops out of service, another device can often take over. Interfaces with smartphones or tablets can be handled by hubs, commercially available devices that are often compatible with two or more of these standards, as well as with Wi-Fi or Bluetooth.
"You have to have a hub to connect with the home network" for most of these protocols, said Tom Kerber, director of research, home controls and energy for Dallas-based market-research firm Parks Associates. "Hubs used to be $200, but now they come on USB sticks, cost $10 and plug into the back of the router."
Fortunately, many widely sold hubs can communicate with devices using two or more of these standards, allowing customers to mix 'n' match to some extent. But let's look at the differences among them.
From the article "ZigBee, Z-Wave, Thread and WeMo: What's the Difference?" by Kevin Parrish.
