Zigbee, sure. That’s essentially the same logic as the IBeacon options, just a different protocol.
But that’s not the same as saying you can use it with the existing plugs that you have now. Those use the zigbee home automation profile. The Freescale solution does not.
It also requires that each person be within distance of three repeaters at the same time wherever they go through the house. That gets pretty expensive pretty fast.
You can see MN1 is in the vicinity (within its transmission radius) of three static nodes, so it is able to estimate its position using a multilateration technique, which can be based on range measurements taken using received signal strength indicator (RSSI) or by measuring the angle of arrival (AOA). AOA implies the use of multiple antennas, so that’s why using range measurement based on RSSI is simpler and lower cost.
Zigbee has a lot of flexibility and there are many different profiles that can be used with it. They cannot all communicate with each other.
The Freescale one requires custom hardware and custom software. So again, you can’t use it with the SmartThings plugs that you already own.
The location repeaters that Freescale is proposing are not also acting as on/off switch is or dimmers or relays. All they’re doing is acting as part of the location system.
So basically you’d have to add three new zigbee devices in every zone Plus one to be carried by every person. It’s possible, if you want to try it. But you won’t have any way of integrating it with smartthings unless you also add a communication component to your location system. (Again, smartthings uses the zigbee home automation profile.)
So you’re still not repurposing the devices you already have. There are a lot of people who would love to see this feature, it’s just not there right now.