The Next Generation Network (NGN) is a telecommunications system that converges all services and information into packets for transfer, accommodating technical advancements high-speed and diversified services through its multilayer architecture. The NGN enables users to consistently and efficiently obtain services, and 5G cellular communication is a viable technology to meet the demand for high data rates in the future, particularly with its mmwave capacity. However, one of the major problems that the new generation faces is non-line-of-sight status, which results from higher frequencies' extreme vulnerability to interference from obstructions and misalignment. This special property makes it more difficult for the widely used Transmission Control Protocol (TCP) to achieve good throughput and low latency across an equitable network. TCP must modify the congestion window size in accordance with the state of the network, but it is unable to effectively adapt to its congestion window, resulting in degradation of the protocol's throughput. This research presents an in-depth analysis of trustworthy communications in 5G networks, examining how TCP affects 5G mmWave networks, the mechanisms and parameters of TCP that portrays the behavior of 5G networks, and a study of the existing problems, and ideas to be fixed. It also suggests a viable study of different methods to enhance reliable communications in 5G networks.