The work presented in this paper analyses the performance of existing WLAN by exploiting the DCF mechanism to enhance full duplex transmission in GPON networks and improve spectrum utilisation. The work concentrates on the hybrid GPON architecture and explores techniques of capacity allocation and interference mitigation. Various patterns of Access Points (AP) as deployed in the Network topology are also analysed. Using our model for computations / simulation results and existing dissertations, we carry out performance evaluation as depicted in the presented results.