This paper refers to a research about 5-channel wavelength division multiplexed passive optical network (WDM-PON) based on optical frequency combs generation (OFCG), using Mach-Zehnder modulator (MZM). The simulations were applied in standard single-mode fiber (SSMF) like an alternative for next generation-PON (NG-PON). OFCG using MZM has been widely studied due to the fact that the spectral spacing is directly related with the RF frequency, and the number of sideband components depends on the RF power. These parameters affect the bit-error rate (BER). Therefore, OFCG shows that suitable channel spacing is required for WDM-PON systems with high data-rate at 10 Gbps. In addition, WDM-PON based on OFCG using MZM at 2,488 Gbps can reach lengths up to 37 Km; this system also provides high performance over the link length up to 22 Km with BER <;10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-12</sup> , 10 Gpbs and flat optical spectrum.