## 1 Introduction  
Electronic healthcare (eHealth) is regarded as one of the most important emerging applications of wireless sensing networks owing to its substantial potential in a wide range of nursing assistance activities. Nowadays, the Internet of Things (IoT) has become a distinguished solution in eHealth [1; 2]. Among the promising, advanced IoT applications, eHealth represents a revolutionary segment and offers numerous convenient solutions to patients, doctors, and nursing assistants [3; 4; 5]. The IoT has a great potential and provides various utilities wherein remote health monitoring of chronic diseases can be regarded as the most significant technology. In this regard, wearable computing technologies are considered to have an incredible influence, because they remarkably eliminate the necessity of continuous physical examination [6]. Wearable technologies are extensively developed by researchers to monitor patients with chronic diseases [7; 8; 9]. These technologies can be demonstrated through wearable armbands or patches embedded in a patient's body. These patches are designed according to the required operation. A wireless body area network (WBAN) has also been developed, in which healthcare signals are transmitted to the monitoring person. These wearable patches require a biosensor. Different biosensors, such as an electrocardiogram (ECG) [7; 10; 11], electroencephalogram [12; 13], blood pressure [14], and oxygen saturation (SpO\({}_{2}\)) [15] sensors, are developed by researchers. However, the effective wireless transmission of these bio-signals has recently attracted a considerable research interest. The bit-error rate (BER) is highly significant in this regard, because the reliability issue must be addressed with proper attention. In real-time remote monitoring of a patient's condition (e.g., the heart rate), the data transmission should be almost completely error-free. Currently, radio-frequency (RF)-based technologies are extensively utilized to accomplish the transmission of healthcare signals to the gateway. A wide range of devices with low-power characteristics, such as Bluetooth low energy (BLE), ZigBee, and IPv6 over low-power wireless personal area networks (6 LoWPAN), are considered useful owing to their cost effectiveness and affordability to the majority of people. Among these technologies, BLE is noteworthy for its low power demand and robustness to obstacles [16; 17]. After the introduction of BLE 4.0 by a special interest group in 2010, a tremendous research interest has been observed in the area of WBAN, not only for its low-power characteristics, but also for its simple protocol architecture [18]. However, the security of BLE remains questionable [19; 20]. For instance, some medical devices are very sensitive to electromagnetic radiation originating from RF-based technologies, which eventually degrade the overall device performance [21]. Moreover, its effect on human health is considerable [22; 23]. RF signals are also prone to inter-channel interference and incur a substantial BER. Therefore, to ensure efficient, reliable, and secured healthcare signal transmission, a congruent complementary to RF-based technologies is required. Optical wireless communication has been actively researched over the last few years. This communication type offers a completely unlicensed spectrum that can be utilized to manage massive future data traffic [24]. Among the communication technologies that use optical spectra, optical camera communication (OCC) is regarded to have significant potential [25]. Herein, a camera image sensor is used to receive an optical signal sent from a modulated light-emitting diode (LED) [26; 27; 28]. LED flickering is captured in the form of binary data. Moreover, OCC is an excellent solution for both long- and short-distance communications and has several useful features (e.g., high security, excellent signal-to-interference-plus-noise ratio (SINR), and high stability with respect to communication distance variation) [26].