In this paper, two models of fiber-to-the-x (FTTx) networks are provided, one of hybrid dense wavelength division multiplexing/coarse wavelength division multiplexing (DWDM/CWDM) with high subscriber’s allocated bandwidth, and the other of hybrid ultra-dense wavelength division multiplexing/coarse wavelength division multiplexing (UDWDM/CWDM) with high network capacity. The effect of the fiber chromatic dispersion on the signal quality was demonstrated. The behavior of the network with respect to the changing of the DWDM channel spacing and the relation between the channel spacing and the system bit rate was discussed.