AT&T Cisco 3G MicroCell Wireless Network Extender requires GPS signal to activate and operate. However, MicroCell may not be able to acquire and lock onto GPS signal in the middle of a house or building. Gilsson High Performance GPS Antenna will allow one to place GPS antenna near a window to receive and boost incoming GPS signal for use with AT&T 3G MicroCell Wireless Network Extender. It is GUARANTEED TO WORK with AT&T 3G MicroCell.