As a result of the rapid growth in wireless communications and the increase in the number of users of cellular phones around the world, massive multi-output, and multi-input (massive MIMO) systems have been used. The main drawback of such a system is the increase in the number of antennas and the amount of energy consumed. To mitigate that the number of active antennas can be reduced to save some energy. In this paper, we will study different algorithms for choosing the suitable antennas in MIMO systems, subject to keeping an acceptable level of bit rate and energy efficiency in the system. The study will also consider the amount of complexity for each algorithm based on the consumed time to perform each algorithm in MATLAB.

Massive MIMO system in the fifth generation can consume a large amount of energy. In this research, the selection of antennas was studied based on several algorithms and a new algorithm was proposed for the selection of antennas. The results showed through a comparison between the approved and proposed methods in the research in terms of capacitance that The proposed algorithm is the closest in terms of capacity to the ideal case, as this method is considered almost ideal for its application in multi-input and multi-output systems to improve performance in the fifth generation, followed by the greedy algorithm and algorithm norm, as it was noted from During the comparison in terms of energy efficiency, it is possible to increase energy efficiency when choosing a certain number of antennas

Transmission Control Protocol (TCP) is built on the concept of self-clocking technique and this concept based on several characteristics. The slow-start mechanism represents the prime technique for usage the operative network resource. The objective of the slow start mechanism is to create a TCP connection in an optimal state - run for network route rapidly without giving a disproportionate load to the network. Due to the rate of packet transferred is limited by the bandwidth of the narrowest bottleneck alongside the connection pipe, then, the transferring rate cannot exceed this bandwidth and the maximum rate competitions the permissible bandwidth of the link that own narrowest bandwidth over end-to-end connections. In large bandwidth networks, the mechanism of slow-start does not perform suitably and may cause considerable degradation in network performance. Therefore, it's necessary to develop a new slow-start technique that can increase the packet transferring over large bandwidth links environments. This article investigates the behaviour of TCP protocol after applying a technique based on using available bandwidth estimation to detect the current level of the network slow-start threshold (ssthresh) in high capacity links used over industrial application.