\begin{table}
\begin{tabular}{p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt}} \hline \hline
**Verticals** & **Parameters** & **4G** & **4.5G** & **5G** & **6G (Proposed)** \\ \hline \multirow{6}{*}{**Verticals**} & Drivers & 3 GPP, LTE & LTE-A, WIMAX & mMIMO, mmWave, eMBB, URLLC, mMTC & FeMBB, umMTC, ELDTC & ERLLC, LDHMC, ELDTC \\ \cline{2-7}  & Frequency band & 2–8 GHz & 2–8 GHz & 3-300 GHz & 0.1–10 THz \\ \cline{2-7}  & Uplink/Downlink & 128/56 Mbps & 3/1.5 Gbps & 20/10 Gbps & 52.6/24.25 Gbps \\ \cline{2-7}  & Peak data rate & 100 Mbps & 1.5 Gbps & 20 Gbps & 1 Tbps \\ \cline{2-7}  & Edge devices data rate & 1 Mbps & 10 Mbps & 0.1 Gbps & 1–10 Gbps \\ \cline{2-7}  & RTT latency (in ms) & 20 ms & 10 ms & 1 ms & 10–100 \(\upmu\)s \\ \cline{2-7}  & Spectral efficiency & 300 bps/Hz & 30 bps/Hz & 120 bps/Hz & 600–1200 bps/Hz \\ \cline{2-7}  & Connected devices & \(10^{4}\) devices/km\({}^{2}\) & \(10^{5}\) devices/km\({}^{2}\) & \(10^{6}\) devices/km\({}^{2}\) & \(10^{7}\) devices/km\({}^{2}\) \\ \hline \multirow{6}{*}{**Verticals**} & Cell size & 6 GHz umbrella small dense cells & mmWave cells of 100 m (fixed) & \(<\)100 m tiny cells with dense mmWave & tiny THz cells with cell-free smart surfaces \\ \cline{2-7}  & Coverage range & 50-80 m & 2 km & 100–150 km & 1500–2000 km \\ \cline{2-7}  & Payload weight & 16 g & 750 g & 4.9–50 km & 150 km \\ \cline{2-7}  & Flying mechanism & Multi-rotor & Fixed-wing & Multi-rotor & Multi-rotor \\ \cline{2-7}  & Speed \& Flying time & 80 km/h \& 6–8 min & 100 km/h \& 45 min & 150 km/h \& 180 min & 482 km/h \& 1800 min \\ \cline{2-7}  & Energy efficiency & 1\(\times\) J & 10\(\times\) J & 100\(\times\) J & 1000\(\times\) J \\ \cline{2-7}  & Power supply & 3.7 V/160 mAh battery & 2700 mAh-3-cell LiPo battery & LiPo battery & 15000 mAh) & 950-shaft-horsepower-turbo-propellant-engine \\ \hline \multirow{6}{*}{**Verticals**} & Radio-only hop delay (in nanoseconds (ns)) & 100 & 100 & 10 & \(<\)1 \\ \cline{2-7}  & Processing delay (in ns) & 100 & 50 & 10 & \(<\)1 \\ \cline{2-7}  & Base station-UAV communication delay & 10 ms & 5 ms & 0.5 ms & 50 \(\upmu\)s \\ \cline{2-7}  & End-to-end reliability (in \%) & 99.99 & 99.999 & 99.99999 & 99.999999 \\ \cline{2-7}  & Mobility & 300 km/h & 350 km/h & 500 km/h & \(\geq\)1000 km/h \\ \cline{2-7}  & Area traffic capacity & 0.1 Mb/s/m\({}^{2}\) & 1 Mb/s/m\({}^{2}\) & 1 Mb/s/m\({}^{2}\) & 1 Gb/s/m\({}^{2}\) \\ \cline{2-7}  & Technology & OFDM, MIMO, D2D, HetNets & Carrier aggregation, Turbo codes & mm-Wave, mMIMO, LDPC, Planar codes, NOMA, Ultra-dense & SM-MIMO, LMS, HBE, OAM MuX, Laser, VLC, Blockchain-based spectrum, Quantum entanglement, Coverage maximization over ML/DL algorithms. \\ \hline \hline \end{tabular}  
3 GPP: Third-Generation Partnership Project; LTE: Long-Term Evolution; LTE-A: LTE-Advanced; WiMAX: Worldwide Interoperability for Microwave Access; mMIMO: Massive Multiple-Input, Multiple-Output; mmWave: Millimeter Wave; eMBB: Enhanced Mobile Broadband; URLLC: Ultra-Reliable Low-Latency Communications; mMTC: Massive Machine Type Communications; FeMBB: Further-Enhanced Mobile Broadband; ERLLC: Extremely Reliable and Low-Latency Communications; umMTC: Ultra-Massive Machine-Type Communications; LDMHC: Long-Distance and High-Mobility Communications; ELDC: Extremely Low-Power Communications; GHz: Gigabertz; THz: Terahertz; Mbps: Megabit Per Second; Gbps: Gigabit Per Second; Tbps: Terabit Per Second; LiPo: Lithium-Polymer; OFDM: Orthogonal Frequency Division Multiplexing; D2D: Device-to-Device; HetNets: Heterogeneous Networks; NOMA: Non-Orthogonal Multiple Access; LDPC: Low-Density Parity Check; Codes; HBF: Holographic Beam-Forming; SM-MIMO: Super-Massive MIMO; OAM: Operations, Administration, and Maintenance; VLC: Visible-Light Communication; LIS: Large-Intelligent Surfaces; MuX: Multiplexer; ML: Machine Learning; DL: Deep-Learning.  
\end{table} 
Table 1: Classification and comparative analysis of 4G, 4.5G, 5G, and 6G against defined verticals to support 3 FFs to tackle COVID-19 [18]. in UAV networks.