BTLE as Proximity Sensor

Hello All,
I am working on a project and I need to run a bit of code when my dog comes near my Arduino.
My initial idea was to use and RFID or NFC setup but the power requirements to read to the distances I need are too great. My second idea was to use a (Bluetooth Low Energy) BTLE beacon and a Bluetooth module on the Arduino to detect proximity. I am not that familiar with the Bluetooth protocol so I'm not sure it's even possible. One of ,y requirements in this is a fairly precise adjustable reading range. For example I'd like to be able to detect when the BTLE device is, say, 1 meter away but also be able to adjust that in code to read from further. Ideally I would like centimeter resolution but I can make due with decimeter or even meter resolutions. Any idea if this would work or of something that would work in it's place? To be clear the dog will be wearing the BTLE button on it's collar and the Arduino will be stationary. I've searched google but couldn't find a good guide on someone trying to do the same thing. Thanks in advance.

Any idea if this would work

In my opinion this would not work. Bluetooth is not like this, there is no way to get a range from it. Even if you could get a signal strength that will not give you a range.

I did read of some company trying to do something vaguely similar with Wi-Fi but it seemed to be all clouded in secrecy.

SneakySalad:
One of ,y requirements in this is a fairly precise adjustable reading range.

Well your idea crops up on here several times a week, so if it were possible you would expect to find lots of examples of working systems with a Google search.

Thanks guys. Since it was a single dongle and not several I was able to get basic functionality for my application using RSSI and the Beacons TX power. I can get a rough resolution of whether the dongle is A)In the house,B)In the same room, and C)In the immediate vicinity of the HM-10 BT module.