## 9 A Novel Methodology for 5G-Enabled Broadband Connectivity Coverage of Smart Cities
Thus, we calculate the range of each smart city antenna based on the following formula:  
\[d(m)=10^{[\frac{\beta(dBm)+G_{t}(dB)-P_{B}(dBm)+27.55-20\log_{10}f(MHz)-(1.645 \times\sigma(dB))}{20}]} \tag{5}\]  
This formula is obtained by incorporating the deterministic and shadowing losses, a predefined total radiated power (EIRP) for the transmitter (municipal base station antenna) and, thus, calculating the maximum range of the antenna, which serves as the 5G-enabled smart city cell radius. Since the smart city platform is implemented with a 5G microwave network, the total radiated power (EIRP) is set to 24 dBm (the logarithmic sum \(Pt(dBm)+Gt(dB)\) in the equation) [5], the frequency equals 3.5 GHz (or 3500 MHz), and the minimum level of the local mean received power is set to \(-85\) dBm. This specific selection of local mean received power level is due to the extensive noise level measurements we conducted in two urban centers: Patras, Greece, and Athens, Greece, with the SNR-3006 EMF equipment [5]. We conducted measurements of the noise levels at various band widths, starting from a reference level of the 1 MHz spectrum. The averaging of the results demonstrates a noise level of \(-95\ dBm\) for the 100 MHz spectrum around the 3.5 GHz carrier frequency. Thus, an average received power level of \(-85\ dBm\) provides a minimum SNR of 10 dB at the cell edge, which approximates the requirement of 10.6 dB for the lower-throughput modulation schemes [40; 41; 42; 43]. Thus, we calculate the range (in meters) of each antenna system of the smart city platform as a function of the shadowing depth (in \(dB\)), as follows:  
\[d(m)=10^{[\frac{65\cdot 6 dB(-1.645\times\sigma(dB))}{20}]} \tag{6}\]  
The variation of the output (antenna system range) with respect to the input (shadowing deviation) is illustrated in the following plot (Figure 1). This method allows for the exact calculation of the cell radius of the smart city platform for each possible value of the shadowing depth (from 0 to 14 dB). The average value of the shadowing depth, for 7.1 dB, gives us a maximum range of 660.7 m, close to the boundary of a 4G/4G+ mobile cell (500 m). For a shadowing depth equal to 10 dB, which is a more realistic value for an outdoor obstacle-dense propagation environment, such as a city urban center [25; 26], the range of each antenna is defined at 197.93 m (\(\sim\)200 m), and the area of each antenna (coverage area) equals 0.1567 square kilometers (sq km). This provides a key planning and deployment distinction between 4G and 5G networks. The importance of calculating the coverage area of each antenna system is that we can calculate the number of total antennas required to cover a total area corresponding to the center of a large city or the whole of a medium-sized city, for the purpose of implementing a smart city platform for a large- or medium-sized municipality, respectively. Since each antenna used by the municipality is an omnidirectional dipole antenna, we consider a circular coverage range, which can be approximated as a square, as depicted in Figure 2, with a square side of 2d, where d is the range calculated from Equation (6). Considering a total square coverage area in a two-dimensional x-y-axis system, the total number of antennas for a given area surface is calculated as follows:  
\[z=\frac{x(m)\times y(m)}{4\times d^{2}} \tag{7}\]  
For instance, a total urban area of 10 square kilometers, suffering from a shadowing depth of 10 dB, provides (from Equation (6)) d = 197.93 m and a respective coverage area equal to 0.1567 square kilometers (square approximation). Therefore, Equation (7) provides  
Figure 1: Antenna range vs. shadow depth for a 5G-enabled smart city broadband coverage scenario. Figure 2: Square approximation of circular coverage. z = 63.816, which is rounded to the next higher integer value and, therefore, we have 64 antennas required (as 5G-enabled municipal base stations at 3.5 GHz) to cover an urban area of 10 square kilometers.