System and method to extend the data carrying capacity of a hybrid fiber cable (HFC) network by adding wideband RF signal capability above 1 GHz, and replacing the CATV amplifier devices with an improved type of Coax Domain Amplifier-Repeater (CDAR) device that, in addition to being a smart reconfigurable amplifier and cable signal diagnostic device, also segments the CATV cable portion of the HFC network into a series of smaller domains. The CDAR often alter RF signals from 5-865 MHz, while more freely passing RF signals over 1 GHz. Upstream capability is enhanced because the CDAR intercept 5-42 MHz upstream signals from each domain and convert to 1 GHz+ signals. Downstream capability is also enhanced because the CDAR can take efficiently encoded 1 GHz+ digital data, modulate it, and locally inject into each domain without crosstalk between domains. CDAR can use active cancellation, and active restoration techniques to improve performance.