# Performance Analysis of Downlink 5G Networks in Realistic Environments
## 6 Simulation Results with Discussion
As shown in Figure 9, when S = 128 and the environment is a free space, the available service can cover 250 people even if the data rate for each user is reduced because all users share resources simultaneously  
Figure 6: Path loss in different propagation environments. Figure 8: Cell capacities for different service factors (S). Figure 7: Maximum distance (coverage area vs. capacity). Figure 9: Cell capacities in different propagation environments (S = 128). Figures 10 and 11 exhibit similar behaviors. For example, in Figure 10, the S value decreases to 64; therefore, the number of active users goes down to 125, whereas when the S value in Figure 11 is 17, the number of active users decreases to 34. Apparently, the number of active users decreases as S decreases. Consequently, users benefit from a higher data rate. The final results of the first group are shown in Figure 12, which depicts the link between the distance from Node B and the capacity for three primary types of environments: dense urban, urban, and rural. For example, 150 users can be served within a 1.5 km distance in suburban areas, where people live with a lower population density than in metropolitan and dense urban areas. In contrast, the same number of users can be found approximately 0.9 km from Node B in urban regions and approximately 0.5 km in dense urban areas with high population density. Figure 12 illustrates the phenomenon of cellular breathing, demonstrating that as the number of users in the cell increases, coverage decreases as a new user interferes with other users. This is an important signal that mobile operators should consider when developing future 5G networks. Figure 11: Cell capacities in different propagation environments (S = 16). Figure 10: Cell capacities in different propagation environments (S = 64). Regarding the second group of results (Figures 13-27), Figure 13 shows the maximum number of active users due to the interference in the multiservice case. It can be seen from this figure that the service factor parameter S has a major effect on the number of active users in the cell. The maximum number of successful admissions was achieved at service factor parameter values higher than small values. For example, the maximum number of active users reached 250 when S was 128, 60 when S was 32, and decreased to 16 when S was 8. Because the cell radius has a major effect on cell coverage, the capacity of the cell is shown in Figure 14 for different cell radii. The maximum number of active users (250 users) is obtained at a cell radius of 2 km and decreased to 100 users when the cell radius was increased to 9 km. In this case, Figure 14 presents an additional explanation of the cell breathing phenomenon, where the coverage of the cell is affected by the cell size and has a major effect on the maximum number of active users. Interference between users also has a major effect on cell capacity. Figure 15 shows that for the interference value (i.e., 0.30), around 200 users can be accepted. In contrast, for a 0.70 interference value, only 100 users were admitted to the system. Figure 12: Maximum distance in different propagation environments. Figure 13: Interference resulting in a maximum number of active users. The aggregate average bit rate is presented in three figures (Figures 16-18). The aggregate average bit rate is expected to be higher in zone 1 than in other zones because zone 1 has a higher achieved bit rate per user and improved modulation level in the cell. In Figure 16, the aggregate average bit rate is given in zone 1 for different service categories. Figure 16 shows that at a low rate (\(\leq\)84 Mbit/s), a higher rate can be achieved for voice over 5G, and as soon as the load increases, the rate for streaming is increased and continues to achieve a higher average bit rate. At a lower rate, the number of users who requested a service was still small. However, users in zone 1 always enjoy higher bit rates than those in other zones regardless of the type of service being requested.