The GSM/DCS/PCS Frequency Shift Repeater (FSR) is designed to solve problems of weak mobile signal, which can expand more coverage than RF repeater and reduce investment for the areas where fiber optic or dedicated cable is not allowed.
The system consists of two parts: Donor Unit and Remote Unit. The Donor Unit receives the BTS (Base Transceiver Station) signal via open air RF transmission or direct coupler closed to BTS, then converts it from the working frequency to the link frequency, and transmits the amplified signal to the Remote Unit that will reconvert the signal to the working frequency and provide the signal to the areas where network coverage is inadequate. And the mobile signal is also amplified and retransmitted to the BTS via the opposite direction.
As per operator’s requirement for link frequency, two types of FSR are available:
In-Band FSR: the link frequency is inside the working band
Out-of-Band FSR: the link frequency is out of the working band