Our signal booster is a high-quality bidirectional signal booster that enhances cellular signals to areas that are prone to weak cellular coverage. works with three antennas: - An two inside antenna that communicates with your cell phone. -An outside antenna that communicates with the cell tower. Signals sent from a cell tower are received by the outside antenna, amplified by the booster and then sent to your phone via the inside antenna. When your phone transmits, the signal is sent to the inside antenna, and then sent to the cell tower via the outside antenna. bars, at best)? is downloading from the internet a painful exercise because of poor reception? do you want to be able to stream from netflix, youtube, amazon prime, iptv and other services uninterrupted and with no buffering? you need a mobile network