The utilization of Fiber Optic (FO) in 5G communication systems has achieved several advantages such as increasing the capacity and the bit rate with a reduction in the total implementation cost. Radio over Fiber (RoF) systems could form the basis for 5G communication networks, due to several reasons related to its ability to provide the required bandwidth for the broadband data transmission to the end-users, other advantages are related with the lower loss in attenuation and higher immunity to RF (Radio Frequency) interference. Particularly, the utilization of Wavelength – Division - Multiplexing (WDM) and Dense - Wavelength - Division - Multiplexing (DWDM) techniques with the RoF system has gained all the attention of researchers in the last few years. As a result, this paper demonstrates a review of the proposed systems, schemes, and methods that contribute in enhancing the WDM and DWDM based RoF systems.