## 3 Problem Statement  
The optimization process of 5G capacity layers [2; 3; 4; 5; 6; 7; 21] involves the identification of optimum values for the adjustable cell/site parameters listed in Figure 1. Each of these parameters contributes in a different way to the network quality and has its own constraints, which will be analyzed in this chapter to detect the most suitable candidate for an automated reconfiguration scheme. Site location (incl. height) is of key importance for the topology of the 5G network as it will dictate the actual position of the cells that will cover an area. Figure 1: Adjustable 5G cell/site parameters. The cell site usually includes a number of cells (typically 3-5) of single or multiple radio access technologies, and it greatly affects the coverage area of each cell. It is generally analyzed combined with the azimuth angle, mechanical or electrical vertical tilt, which are all key to estimating the achieved coverage for each included cell. The site locations are placed in areas with clear line of sight and with an increased height. They also require computation units for the radio processing, which needs specialized housing structure and power supplies. This makes the relocation, addition, and maintenance of new site locations a complicated and costly process. Cell azimuth angle describes the direction in which the receivers of the radio signal will acquire the maximum antenna gain. This will result in higher data rates, provided that the interference levels allow for transmission. The azimuth angle is an installation parameter on the site that is changed in a relatively slow pace, typically after reconfiguration and optimization orders from the radio optimization team. Cell azimuth steering can play a key role in improving the coverage and quality of users within a zone where hot-zones have been formed due to urban structures such as plazas, shopping malls, recreation areas, and university campuses. In addition to the physical cell azimuth configuration, beamforming azimuth steering is also available via MIMO configuration of the antenna. However, the value range of this change is restricted, usually in a +/\(-\)20 degree range from the physical azimuth angle, making the physical cell azimuth a more impactful planning parameter. Cell vertical tilt (electrical or mechanical) can also be an important configuration parameter of the 5G cells. This parameter also affects the center of maximum antenna gain, which we described in the azimuth steering case as they are important factors in the 2-D antenna gain computation. In modern deployments of 5G, however, the quality is due to the impact of pathloss and absorption for the carrier frequency. However, the use of higher carrier frequency bands minimizes the expected range of the cells, making for denser networks with higher vertical tilt values. Another parameter that can also be considered is the radio bandwidth and carrier frequency of the cell. These parameters can greatly impact the maximum capacity of the cell as well as the achieved radio and are not flexible parameters to configure, mostly due to the competition-based spectrum acquisition process that is conducted by the regulation authorities. The 5G access network MIMO/spatial multiplexing operational mode is also a tunable aspect of the cellular network. Depending on the relative position of the mobile terminal with respect to the gNB cell, its radio capabilities, and the current (instantaneous) channel conditions, multiple radio access paths can be utilized to multiply the capacity of the radio link by a significant factor. While MIMO configuration optimization is a very active topic of research in this field, data-driven approaches have been shown to perform better in real time optimization and are not in the scope of network planning. Out of these configuration actions, the cell azimuth steering is expected to provide the greatest benefits for the cases of dense urban traffic hot-zones that will be part of our study.