I'm looking for a way to distinguish hardware devices via BTLE. I'm quite open to using any system (Estimote, Gimbal etc) but I need to find a way to identify a device before any handshake is given.
For example: If there are 20 BTLE enabled devices in an area, I would like to identify them uniquely ahead of any broadcast.
Standard iBeacons do exactly this. They advertise a unique three part identifier (Proximity UUID/major/minor) that requires no handshake to read. It is detectable on iOS, Android, Mac and Linux platforms. The three part identifier is sent in the clear in a BLE advertisement.
More detail on this advertisement format is available here: What is the iBeacon Bluetooth Profile
Shameless plug: my company makes beacons and services that work with any standard iBeacon and are interchangeable with other vendors' products that are also standard iBeacons. More information about our beacons and services is available here: http://www.radiusnetworks.com