A system is provided for combining conventional HFC plants with fiber-optic access systems (e.g., fiber-to-the-home or fiber-to-the-curb) that share a head-end and other equipment. A robust modulation format, such as QPSK, having a sufficient SNR to transmit information (e.g., data, digital audio and digital video) downstream to users' premises via a fiber-optic access system is used. Also, a method and apparatus is provided for converting a first modulation format for information received via a fiber-optic access system to a modulation format compatible with customer premises equipment.