# System Architecture Design of IoT-Based Smart Cities
## 6 Case Study Research
### Case Study-Smart Charging  
The previous section has described the reference architecture for IoT-based smart cities. A family feature diagram, the reference decomposition view, the reference layered view, and a reference deployment view has been provided. In this section, we provide a case study on smart  
The proposed smart EV charging system is designed to provide electric vehicle (EV) owners with a convenient, reliable, and sustainable solution for charging their vehicles. The system's design focuses on placing EV charging stations in key public locations, such as parking lots and shopping centers, that are easily accessible to EV owners. This will help EV owners to charge their vehicles at a convenient location and at a time that is most suitable for them. The EV charging stations in the system will be connected to a centralized management system, including each physical charging station's virtual replica or digital twin (Figure 7). The virtual representation will reflect the current state, such as usage and power status, of the corresponding physical station in real-time. This will allow the central management system to monitor and control the charging stations remotely, ensuring they operate efficiently and effectively. The \"EV Charging Central Management\" application will maintain the central management system, which will interact with other services, such as payment and database. These services will help manage the financial transactions associated with EV charging, such as payments and billing. Additionally, the central management system will also communicate with external systems, such as banking and city electricity management. This will enable the system to integrate with other systems and provide a more comprehensive service to EV owners. EV owners can access the central management system through a mobile or web application, which will allow them to locate available charging stations, view real-time charging status and pricing information, and initiate and pay for charging sessions. This will make charging EVs more efficient and user-friendly, promoting greater adoption of electric vehicles. The mobile or web application will also allow EV owners to schedule charging sessions in advance, ensuring the charging station is available when needed. Furthermore, the app will provide real-time notifications on the charging status so EV owners can plan their trips accordingly. The proposed smart EV charging system aims thus to provide a convenient, reliable, and sustainable solution for charging EVs. Furthermore, integrating the charging stations with a centralized management system will enable efficient and effective management of the charging stations, making charging EVs more user-friendly for EV owners. This will help promote greater electric vehicle adoption and contribute to a more sustainable future. \begin{table}
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**Case Study Design Activity** & **Case Study Element** \\ \hline Goal & Assessing the effectiveness of the method Assessing the practicality of the method \\ \hline Research Questions & RQ1. To what extent does the method support the architecture design of the DDS-Based Smart City IoT architecture? RQ2. How practical is the method for deriving DDS-Based Smart City IoT architecture? \\ \hline Background and source & Official requirement documents Project managers and system architects \\ \hline Data Collection & Indirect data collection and direct data collection through semi-structured interviews (mix of open and closed questions) \\ \hline Data Analysis & Qualitative data analysis \\ \hline \hline \end{tabular}
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Table 1: Case Study Design. While the proposed smart EV charging system has several benefits, it also comes with deployment, infrastructure, and maintenance costs. The deployment cost involves installing the charging stations at various public locations, including parking lots and shopping centers, where EV owners can easily access them.