A system for transporting a plurality of digital signals includes a head-end unit for routing each digital signal to a particular modem, according to address information in the signal. At its respective modem, each digital signal is mixed for further transmission on a unique, modem-specific, radio frequency (fn) that is predisposed for a sub-octave transmission. A first converter then “stacks” a plurality of the different digital signals onto a common wavelength (λ) for transmission as an optical signal over an optical fiber. At the receive end of the optical fiber, a second converter “de-stacks” the plurality of digital signals, and segregates them according to their respective unique radio frequency (fn). A distribution unit then directs each unique radio frequency signal to an addressed node for further transmission over a secondary network.