*3.4. Sixth Generation*

The sixth generation (6G) of wireless communication refers to the next generation of mobile network technology that will follow the current 5G technology. 6G is expected to bring significant improvements in terms of data transfer rates, latency, reliability, and efficiency, as well as support for new applications and use cases. Some of the key features and capabilities that are expected to be part of 6G include the terahertz (THz) frequency band; 6G is expected to operate in the THz frequency band, which could enable much higher data transfer rates than the current 5G technology. Artificial Intelligence (AI) integration: 6G is expected to leverage AI to enhance network management, optimize network resources, and provide better user experiences [13]. Quantum communications: 6G could use quantum communication technologies to provide highly secure communication channels that are immune to eavesdropping. Ubiquitous connectivity: 6G is expected to enable seamless connectivity across a wide range of devices, including wearables, vehicles, drones, and smart home appliances. Holographic communication: 6G could enable holographic communication, allowing users to interact with virtual objects and environments in real-time. Enhanced mobile edge computing: 6G is expected to support the processing of data at the network edge, enabling low-latency, high-bandwidth applications such as virtual reality and augmented reality [13]. While 6G technology is still in the early stages of development, research is already underway to explore and develop some of these capabilities. It is expected to be commercially available sometime in the 2030s [192].

#### **4. Examples of Smart Cities**

There are many smart cities around the world [193] that are implementing advanced technologies to improve the Quality of lives of their citizens, increase sustainability, and enhance the efficiency of city. To develop smart cities, there are There are open-ended three phases defined as Smart City 1.0, Smart City 2.0, and Smart City 3.0 [194], and Smart City 4.0 [195] inspired by economics.
