The Federal Communications Commission's Laboratory Division has completed a second phase of its measurement studies of the spectrum sensing and transmitting capabilities of prototype "TV white space" devices. These devices have been developed to demonstrate capabilities that might be used in unlicensed low power radio transmitting devices that would operate on frequencies in the broadcast television bands that are unused in each local area. This book describes the tests performed during the second (Phase II) series of tests and provides a compilation of the results of measurements of the spectrum sensing and transmitting functions of various prototype "white space devices" (WSDs).