A while back, we took a look at what seemed to be the dominant two radio protocols in new Internet-of-Things announcements: Bluetooth Low Energy and WiFi.
Which resulted in Zigbee raising their hands and doing a virtual “Ahem…”
So I followed up with a discussion of Zigbee, and the ensuing LinkedIn discussion was passionate (and not necessarily kind to Zigbee).
Emotions and ease-of-use issues aside, the biggest differentiators appear to be range (Zigbee wins) and mesh capability (Zigbee has, Bluetooth doesn’t).
If distance is your issue, then meshing gives you an extra distance bonus, since nodes need only be near each other; the Mother Node or hub or whatever can be much farther away. Traffic will arrive at its destination not through the air in a hub-and-spoke manner, but through the network. The only consideration here is the fact that all of this traffic will be traveling through the nodes, which otherwise would be handling only their own traffic. With a mesh, they also have to route other traffic as well.
So if this sort of configuration is what you need, then it would seem that Zigbee would be the only obvious solution.
Or would it?
CSR has introduced what they call their Smart Mesh. And it’s not Zigbee: it’s built over Bluetooth Smart. Why go through all that effort to do something Bluetooth wasn’t originally designed to do? It goes back to the reason I thought Bluetooth and WiFi were dominating: they’re in smartphones, and Zigbee isn’t.
This adds yet one more wrinkle to the distance scenario above. Yes, if you have a Bluetooth hub, a mesh will give you network reach far beyond what that hub could do on its own. But with the phone, you now have a “mobile hub,” if you wish. As long as you’re in range of one of the nodes, anywhere in the network, the phone can access the network for information or control.
You can find out more about CSR’s specific solution in their announcement.