I'm coding a Java ME app and attempting to globally identify each phone using the app. The first attempt is to load the IMEI per this question. As a fallback ID I'm using the bluetooth address of the device. Is the bluetooth address of a cellphone a globally unique identifier? Is it a MAC address? Some other format?
Yes it is unique and works just as MAC addresses. Bluetooth use the MAC-48 identifier format.
It is unique, however do remember that on some handsets (Sony Ericssons?) Bluetooth needs to be switched on before the address can be obtained. This can cause a security prompt in unsigned midlets, asking the user for permission to switch Bluetooth on, which could cause confusion if your app doesn't use it for anything other than unique handset identification!
来源：https://stackoverflow.com/questions/2004065/java-me-is-the-bluetooth-address-id-globally-unique