I canceled my ground phone service as many people did. However cell phone is a radio and it is unstable in some week signal areas. This Booster is alternative to Microcell of AT@T (which required Internet) and does not require any additional connections. It just boost your cell phone signal in limited area in radius at least 30 feet from antennas. Here what I did. I had no idea where is the cell phone transceiver tower so I found most powerful spot with maximum signal bars with my cell phone near window, mounted cradle antenna with logo sign facing window, mounted cable from this antenna across the room to amplifier, connected "on board" antenna (cable about 4feet with desktop antenna) to the amplifier and moved away from amplifier as far as possible facing logo on this antenna in opposite side to first one (back to back). I got green light immediately and 6-7 bars instead 2-3.