The 5G mobile access and backbone networks and the BFWA (Broadband Fixed Wireless Access Network) systems are new terrestrial cellular point-to-multipoint and mesh networks, wherein both the TSs (Terminal Station) and the BSs (Base Station) have either fixed locations and/or mobile places. BFWA systems can be applied in several areas. There are applicable for providing high speed Internet, transferring high speed multimedia (video, sound) data. It can be used for feeder network of GSM, UMTS and B3G/4G, 5G systems, and it can replace some wired solutions. These broadband services need using of high carrier frequencies e.g. around 40 GHz. Because of this used high frequency, the most degrading factor in these systems is the rain attenuation. After working up the related literature the main task is focusing on the studying of rain fading and the applicable fade mitigation technics in BFWA system (frequency allocation, diversity technics etc.), and performing computer simulations in this area in python language.