Indosolution In Building Solution. Together with Guanri, Indosolution provide the best solution for telco in building network. The GSM/CDMA Indoor Band-Selective Repeater is designed to provide a cost-effective solution to the indoor coverage problem due to signal fading and attenuation caused by architecture obstacles. And its easy installation and maintenance can help carrier get fast return. The repeater is working as a relay between the BTS and mobiles. It picks up the strongest signal from BTS via the Donor Antenna, linearly amplifies the signal and then retransmits it via the Indoor Signal Distribution System to the weak/blind coverage area. And the mobile signal is also amplified and retransmitted to the BTS via the opposite direction. The band-selective function can choose the efficient working band customized for the GSM/CDMA carrier. All signals in the whole band will be amplified.