GPS Signal Booster is are-radiating equipment. It can receive the outdoor GPS satellite signal and conduct to indoor place for radiating again. When a GPS Satellite is revolving around the earth it will transmit continuously satellite signal to the earth, but the strength of satellite signal will weaken to only around -125dBm when it arrived to the earth ground. Such weak signal can’t penetrate into buildings or vehicles; besides, its reflection or scattering signal can be detected only in around windows area.