## 1 Introduction  
Optical Camera Communication (OCC) is a subset topic of Optical Wireless Communications (OWC), which involves the optical spectrum to transmit and receive signals. OCC is the development technology of visible light communications (VLC), which is performed using LEDs and photodiodes as transmitters and receivers. Instead of using photodiodes as receivers, OCC uses a camera as the receiver, while on the transmitter, various devices can be used, such as LEDs or even digital signage [1]. Several sophisticated technologies have been developed and technological definitions have been found in recent years. The Internet of Things (IoT) is one of the trending terms that has diverse meanings with one goal, defining a paradigm where things are interconnected, capable of communicating with one another, and can be adjusted over time for users' needs as well as work autonomously to exchange data between entities [2]. The idea of IoT can be traced back to 2005 when the meaning of IoT was to integrate technology into human's everyday human life [3]. Previously, radio-frequencyidentification (RFID) was the only technology that was considered to be a communication medium that was able to perform IoT [4]. However, IoT can consist of various sensor devices and communication interfaces deployed in local or even separated areas currently. The gained data are processed using advanced algorithms to obtain deep insights and information depending on the target of the IoT system [5]. In addition, from these diverse data, a better understanding and insights can be gained for some actions or prevention that can be applied to the IoT system installed area [6]. Furthermore, with the advancement of recent technologies, IoT systems are currently supported by several sophisticated technologies such as edge computing that enables IoT systems to generate decisions and interact between sensor devices in real-time processing [7]. Concurrently, IoT has been implemented in various fields, including the industrial field known as industrial IoT [2]. The IoT system is adjusted based on the industry's characteristics. For example, in terms of sensing devices used, agricultural industries use different sensing devices than the basis of industries used in construction industries [5]. In agriculture scenarios, the sensor devices used are those that function to monitor crops and plants, such as light sensors, temperature sensors, and soil moisture sensors [8]. In the construction industry, most IoT data are collected from vibration sensing systems, which include various sensor devices such as a triaxial gyroscope, triaxial magnetometer, and triaxial accelerometer [9]. Another implementation is security systems, where the IoT is used to enhance security in homes or public facilities. Early implementations used cameras as sensing devices and connected them over a local area network (LAN) system [6]. However, surveillance of an indoor building or an outdoor environment can be performed not only over a LAN network but also from remote places due to the increasing ability of internet technology to process the data [7]. For example, in smart home applications, a camera installed inside the house can be tracked through the internet server or cloud from smartphones or tablets [3]. In the medical field, or the Internet of Medical Things (IoMT), more efficient and faster processes in healthcare systems are urgently needed. In addition, increasing health costs from year to year are also transforming into other problems. Therefore, technology development and its use play a significant role in improving the healthcare system [10]. Despite implementations in various fields, the IoT has its base architecture, although it is yet to be standardized. However, the base architecture is derived based on the process similarity among the IoT system implementations [4]. Considering the existing systems, IoT architecture can be divided into five main layers: sensing, communication, cloud, management, and applications layers [11].