The SRT1F system processes STM-1(155.52 Mbit/s) base band signals in the SDH hierarchy, limiting their bandwidths within a single radio frequency band stipulated by ITU-R based on a multi-level QAM modulation technology (such as 64or 128 QAM depending on radio frequency spacing). This system can support the full range of radio frequency bands recommended by ITU-R (4G, 5G, L6G, U6G, 7G, L8G, 11G,13G) and frequency spacing of28 MHz, 29M Hz, 29.65 MHz and 40 MHz.