## 2 Related Works  
A smart home control system is an important subsystem of an SHS as it organizes intelligent appliances into a network and manages their working states. It aims to provide users with a convenient, power-efficient, and secure method to adjust their living environments. Considering this significant role, researchers are focusing on smart home control systems, with research emphases ranging from system architecture to significance, various control methods, and system applications. To provide users with better services, seven design principles for smart home control systems have been established for programming the software of the control system [18]. A power line communication (PLC)-assisted smart home control system [19; 20] utilizes the power line to transmit control messages among smart devices and supply power considering the environment parameters collected from the wireless sensor network (WSN) to save energy. This system offers high accuracy control but suffers from low scalability as it relies on a fixed power line structure. An IoT-based smart home control system [21; 22] includes WSN to provide environmental information, as well as a control system based on a gateway, cloud server, and smartphone app. This scalable control system offers a remote management function but suffers from poor control accuracy with unsolved security problems. Another type of smart home control system is supported by information fusion [23] and consists of an information fusion-based controller, power line, Bluetooth wireless networking, and computational units. It collects external factors and utilizes a fuzzy neural network (FNN)-based information fusion algorithm to determine the states of smart devices automatically. This system combines wireless and wireline networking for scalability and accuracy, although it lacks consideration for security. A smart home control system based on ZigBee [24; 25] utilizes ZigBee with the IEEE 802.15.4 standard for communication and provides automatic energy management for energy saving. However, this system also faces accuracy and security problems. The security problem of SHS is widely discussed, along with potential solutions. Figure 1: Application scenario of proposed VLC-based smart home control system. To date, only a few works have proposed the use of VLC in the context of smart homes. The idea of using purely VLC-based bidirectional communication for smart home connectivity was proposed in [26]. In [27], the authors presented an encryption mechanism to prevent the intrusion of adjacent adversaries in smart home settings. However, they did not discuss the related practical deployment scenarios and associated challenges. The security aspect of VLC-based smart home system implementation was discussed in [28], where an automated user authorization scheme based on proximity to visible light was presented for smart home settings. In addition to the lack of positioning accuracy, the presented design was based on a small prototype with a photodiode used as a receiver, making it impractical for integration with a smartphone and real-world deployment. In the commercial application area, wireless-communication-supported smart control systems are also widely considered. Reference [29] introduces the plug load management system for energy saving, which comprises intelligent socket devices, a gateway, and a cloud server. The wireless communication among devices and the cloud server contributes to the users by measuring and analyzing device energy use. Reference [30] has mentioned a smart energy management system based on an IoT network. It uses the interconnected network to organize the modules and subsystems and implement the plug load automation. A smart energy management system controlling the sockets through ZigBee is proposed in [31]. It aims to reduce power consumption with a motion sensor and set the time of power usage.