A Wavelength Division Multiplexing (WDM) access network using high-speed free-space optical (FSO) communication based on the passive optical networks (PONs) for the distribution link is proposed. In such network architecture, the FSO link can extend the system to areas where an optical fiber link is not feasible, and or provide limited mobility for indoor coverage. The performance of Hybrid Fiber/FSO (HFFSO) network based on digital pulse position modulation (DPPM), for both the indoor and outdoor environments of the optical access network, are compared with the performance of such a network that is based on conventional On-Off Keying Non-Return-to-Zero (OOK-NRZ) modulation using results obtained through computational and analytical modeling. The WDM channels suffer from inter-channel crosstalk, while the HFFSO communication performance in a clear atmosphere is limited by atmospherically induced scintillation. The impairments, plus the amplified spontaneous emission noise from optical amplification, combining in a potentially problematic way, particularly in the upstream direction, which is investigated here. The results obtained indicate that in a clear atmosphere with a sufficiently high signal to crosstalk ratio the proposed system can achieve a human-safe and high-capacity access network. Dense Wavelength Division Multiplexing (DWDM) has dramatically increased the capacity of optical transmission systems. Its inherent advantages have made it the current favorite multiplexing technology for an optical network, also used on fiber optic backbones and long-distance transmission. The crosstalk due to inter-band crosstalk for Ultra-Dense WDM systems causes higher noise and degrades the network performance and analyzed the performance of DWDM-PON link that is corrupted crosstalk for Optical Cross-Connect (OXC). Then the analysis of BER with crosstalk was done. Using the equation for crosstalk number of channels was plotted using Matlab. An analysis is carried out to find the amount of crosstalk considering a WDM-FSO over OOK-NRZ and DPPM based OXC. The bit error rate performance degradation due to crosstalk is evaluated for the OXC parameter and number of wavelength per fiber.