Interference Mitigation in Femtocell using Optimized Power Control the OFDMA system. While in the downlink there will be Noise rise at femtocell UEs in the CDMA system and will introduce Femtocell Coverage Holes for both systems. Other scenario is the cross layer interference problems which caused by two systems. It can be categorized as follow: the uplink in the CDMA will have Noise rise at the FAP and Noise rise at the macro-BS. While in the OFDMA there will be intercarrier Interference at the FAP and Risk of invalidation of macrocell subchannels. In the downlink CDMA will suffer from Femtocell Coverage Hole and Indoor & outdoor macrocell coverage holes while in the OFDMA it will cause intercarrier Interference at the macrocell users in addition to the Femtocell coverage holes. Finally there will be The Near­ Far Problem that happens if a mobile close to the Node-B increases its power too much and eclipses the signal of a much further mobile. Femtocell interference has been extensively be synchronous with the desired macro signal, otherwise an Inter-Carrier Interference (ICI) and a potential Multiple Access Interference (MAI) will influence the users' performance. The chapter proposes a direct connection with the MBS for the control of a channel communication which is not the case in most of the practical deployment scenarios. Schroder et al. (2009) presented ways for a user- assisted coverage configuration and interference optimization. This solution is tedious since it will depend on the survey that the user has to complete and on top of that it needs professional users who must know how to deal with the scenario as well as the operators who have to produce independent solutions and different scenarios based on the deployment environment which is impractical. Finally, Jo, Mun, Moon, & Yook (2009) pro- poses interference mitigation by using an uplink Power Control (PC) which adjusts the maximum