# Unleashing the Potential of 5G for Smart Cities: A Focus on Real-Time Digital Twin Integration
## 2 Current Trends for 5G in Smart Cities
### Existing Applications of 5G in Smart Cities  
The arrival of 5G technology has greatly enhanced the functions of smart cities, using in a new age of connectivity and innovation in multiple areas [9; 32]. Some of the most revolutionary applications include IoT for urban oversight, intelligent transportation networks, and public safety frameworks, all of which utilize the low latency, high speed, and extensive device connectivity provided by 5G [20; 32]. Prior to 5G's deployment, these applications faced several challenges, such as network congestion, limited device connectivity, and delays in real-time data transmission [9; 32]. In urban IoT networks, for instance, limited bandwidth and high latency obstructed the timely collection and analysis of data, decreasing the effectiveness of systems like waste management, environmental monitoring, and smart traffic control. As cities expand and more devices are connected, these limitations have become more apparent, causing inefficiencies in resource management and emergency response times. 5G directly addresses these limitations by providing a high-speed, high-capacity network with ultra-low latency, which is needed for real-time applications that smart cities rely on [20; 32]. IoT for urban monitoring is needed for smart cities to effectively manage resources and to enhance the quality of life in urban areas. 5G improves IoT networks by enabling a large volume of connected devices with low latency, facilitating real-time data gathering and analysis throughout different urban systems [18; 20; 30; 31]. For instance, environmental sensors placed in urban areas can track air quality, noise pollution, and water consumption, delivering practical information to city officials [33; 34]. In the same way, intelligent waste management solutions utilize IoT-connected bins that relay fill levels, improving collection routes and lowering operational expenses [35; 36]. These applications illustrate how 5G enhances data-driven decision-making, ensuring that urban areas become more sustainable and enjoyable to live in. However, current implementations of IoT in smart cities face limitations, such as network interference, inefficient data processing, and inadequate communication between devices in densely populated environments [18; 20; 30]. Traditional communication networks, like 4G, struggle with meeting the increasing demand for enhanced device connectivity and data transmission [22; 23; 24]. 5G's capability of managing millions of connected devices simultaneously and of transmitting data with minimal delay significantly improves the reliability and responsiveness of these systems [34; 35]. By eliminating bandwidth bottlenecks and improving real-time processing, 5G promotes a smoother and more efficient functioning of IoT applications ranging from waste and energy management to environmental monitoring. Figure 2 depicts how IoT devices are connected in a smart city environment via an urban sensor network. The illustrated network in Figure 2 is a representation of a wireless sensor network (WSN) tailored for urban environments, specifically within the context of smart city infrastructure [32; 33; 36]. These networks consist of interconnected IoT sensor nodes that collaborate to monitor, collect, and transmit real-time data such as traffic flow, air quality, energy consumption, and infrastructure health across various city systems. In a smart city setting, such networks play a critical role in enabling adaptive services, ensuring efficient resource usage and supporting data-driven governance. The network shown in Figure 2 embodies a decentralized and self-organizing architecture typical of WSNs, where nodes interact without the need for a central controller, mimicking the way IoT devices naturally integrate into urban ecosystems. Its graph-based representation also reflects real-world communication patterns among devices, which is essential for modeling and for improving urban connectivity.