Not exactly Bluetooth
The article appears to incorrectly identify a “Bluetooth radio” rather than the Micaz, per the paper. The MICAz is a 2.4GHz IEEE 802.15.4 mote module for enabling low-power, wireless sensor networks. Bluetooth is too power hungry for this type of application. More information on the MICAz can be found here - http://www.xbow.com/Home/wHomePage.aspx, and information on other Mote applications is available here - http://blog.xbow.com/.