## 1 Introduction
### Related Literature Overview and Key Motivations  
Smart cities and smart grids are currently popular and highly researched topics in both academic and industrial sectors. Numerous works and publications have been dedicated to exploring the latest research trends and technological foundations in the smart grid communication networks of smart cities. A survey was published based on the multiple applications of IoT-Fog architectures for smart cities [66]. Moreover, the challenges of fog computing were also discussed in this paper. A recent survey on deep learning techniques in terms of privacy and the security enhancement of a smart grid network for a smart city was conducted [67]. A systematic cyberattack survey for various smart grid components through smart grid networks was described in [68]. The challenges and opportunities of smart grid communication networks were described in [2]. However, major 6G-enabled smart grid applications were not elaborately studied in [2]. The encompassing investigation of the latest research trends, as well as the technological foundations, in smart grid communication networks was described in [24; 69]. In that study, the prospects of a next-generation intelligent smart grid based on AI, 5G, and the IoT was delved into. However, major 6G-enabled smart grid applications were not deeply investigated in [24; 69]. Vulnerability assessments in terms of a massively connected CPS of 6G-enabled smart grid systems were described in [70]. A comprehensive survey of 6G in the case of only low-latency and secured applications of smart grid systems was described in [71]. In addition, 6G wireless communication that is incorporated into autonomous connected devices (ACDs) was also assessed in [72]. But smart grid applications by 6G wireless  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**KPIs** & **5G** & **6G** \\ \hline Peak Data Rate & 20 Gbps & 1 Tbps \\ Peak Spectral Efficiency & 30 bps/Hz & 60 bps/Hz \\ Experienced Data Rate & 0.1 Gbps & 1 Gbps \\ Energy Efficiency & 0.5 pl/b & 1 pl/b \\ Area Traffic Capacity & 10 Mbps/m\({}^{2}\) & 1 Gbps/m\({}^{2}\) \\ Latency & 1 ms & 10–100 us \\ Jitter & Not Specified & 1 μs \\ Connection Density & \(10^{6}\) devices/Km\({}^{2}\) & \(10^{7}\) devices/Km\({}^{2}\) \\ Reliability & \(10^{-5}\) & \(10^{-7}\) \\ \hline \hline \end{tabular}
\end{table}
Table 1: Comparisons between the major KPIs of 5G and 6G [1; 7; 63; 65].  
communication were not deeply studied in [72]. Table 2 summarizes the methodologies and limitations of some of these potential previous survey papers on smart grid networks.  
Table 2 depicts the previous works that have primarily focused on security, vulnerability, and latency assessments of futuristic smart grid systems, as well as those that have discussed the technological foundations of smart grid communication networks with regard to 5G/6G wireless communication. However, they have not thoroughly examined the challenges related to massive connectivity and monitoring, secured communication for resource allocations and operations, and the time-critical operations of smart grid systems. Furthermore, the prospect of 6G wireless communication in the context of the abovementioned smart grid applications was not adequately investigated in the existing literature in terms of the novel communication technologies. This paper seeks to bridge this gap by exploring these critical aspects and shedding light on the potential of 6G technology for addressing the abovementioned challenges in smart grid applications.