Elevator shafts are narrow spaces enclosed by reinforced concrete and extending tens of meters in height. The elevator car and its doors are made of metal, which greatly attenuates mobile signals. Without a signal booster, mobile phones cannot be used reliably inside the elevator.

Amplitec's C17L / A17L series elevator mobile signal booster provides a very cost-effective solution. The system consists of a C17L master unit and an A17L slave unit, and is available in single-band, dual- band, tri-band and multi-band models.

The C17L master unit is installed in the elevator machine room. A log-periodic antenna is used as the donor antenna and mounted outside the machine room, pointing toward the base-station tower. If the total height of the elevator shaft exceeds 50 meters, an A17L slave unit is installed on top of the elevator car. A low-gain panel antenna is used as the service antenna to radiate the inside of the elevator car, while a directional log-periodic antenna is used as the donor antenna facing into the shaft to receive signals from the base station along the shaft.