## 3 Major Applications of the Smart Grid Served by 6G  
The smart grid holds immense significance for the advancement of the sustainable smart city. The key features of the smart grid communication network are its reliance on high speed, reliability, low latency, low jitter, flexibility, massive connectivity, higher area capacities, computational offloading, and secure data communication networks to effectively and intelligently manage complex power systems. Unlike traditional power grids, smart grids employ bidirectional communication, which greatly enhances their capabilities [102]. However, the specific communication demands and appropriate techniques can vary based on the particular environment and circumstance.  
Figure 4 illustrates the flowchart regarding the operation logic and framework for implementing a smart grid by 6G. The goal and objectives of the smart grid communication network for the smart city applications are defined, such as massive connectivity and monitoring, secured communication for operation and resource management, and time-critical operations. The 6G-enabled smart grid infrastructure is designed based on these major requirements. The requirements are considered based on the goal and objectives of the smart grid for smart city applications. Afterward, all the requirements based on the objectives are verified. Subsequently, 6G-enabled smart grid infrastructure is deployed and integrated into the control and monitoring system. Afterward, the smart grid functionalities  
\begin{table}
\begin{tabular}{c l c} \hline \hline
**Novel Technologies** & **Achieved KPIs** & **References** \\ \hline mMIMO & Improved SE, capacity, EE & [79; 80; 81] \\ NOMA & Improved connection density, data rate, SE & [82; 83; 84; 85] \\ EH by WPT & Environmentally friendly, improved SE, EE & [86; 87; 88; 89] \\ mmWave and THz & Improved data rate, capacity, SE, EE, low latency & [1; 93] \\ AI-based UDNs & Improved network efficiency, EE, SE, low jitter & [1; 94] \\ IRS & Improved SE, EE, area capacity & [95; 96] \\ Beamforming & Improved SE, EE, less power consumption & [81; 97] \\ AI-based secured edge/cloud computing & Improved EE, enhanced security & [8; 76; 99] \\ D2D communication & Improved SE and EE & [101; 102] \\ \hline \hline \end{tabular}
\end{table}
Table 3: Improved KPIs by the respective novel techniques of 6G.  
are tested and validated. The monitoring and management of a smart grid by 6G-enabled wireless communication is also performed accordingly, as is depicted in Figure 4.  
At present, low carbonization is one of the prime concerns for the power grid systems of smart cities [103]. The integration of 6G and a smart grid is a suitable solution for enhancing the coordinated operation of the smart grid by a damping technique for low carbonization. A 6G-enabled smart grid can provide real-time monitoring and a control of energy flows. Moreover, the integration of 6G and a smart grid can also provide enhanced energy efficiency, reduction in carbon emissions, and the support of sustainable energy practices. In addition, this synergy provides real-time grid condition monitoring, demand responses, wide-area monitoring and control, advanced control, and efficient load management by the massive, high-speed, and low-latency 6G wireless communication. Grid resilience, cybersecurity, and supportive policies play critical roles in ensuring a sustainable and reliable smart grid ecosystem by utilizing sustainable, secured, and reliable 6G wireless communication. The technology of 6G could have a significant impact on the various applications of smart grid systems. This paper mainly focuses on massive connectivity and monitoring, secured communication for operations and resource management, and the time-critical operations of smart grid systems. The major applications and respective novel techniques are mentioned in the following subsections.