The GATE test bed cornerstones are three autarkical ground transmitters, emitting the Galileo signals into the test area in the region of Berchtesgaden (Germany). Two monitoring stations located within the test area are receiving and processing these signals. A central processing facility which is the core of GATE is steering and controlling the signals transmitted. These Galileo signals are fully compliant to the Galileo OS SIS ICD specification. With the GATE ‘Virtual Satellite Mode’, realistic moving Galileo satellites can be simulated in addition to the Galileo Initial Service Phase satellites in orbit, supporting commercial Galileo receivers without any modifications. Furthermore, the integration of additional sensors like odometer or inertial sensors allows testing of sophisticated integrated navigation systems and applications under realistic environmental and dynamic conditions. With full control over the additional GATE ‘Galileo satellites’, the navigation data content of single satellites visible to the receiver can be manipulated, satellite clock errors (feared events) simulated and even the signal waveforms can be deformed (Evil Waveforms) . Further extensions of the test bed regarding interference and jamming are planned to come in near future.