One of the fundamental issues in the field of wireless communication is security. To overcome this problem, hybrid radio frequency (RF)/free space optical (FSO) link with the presence of an eavesdropper present are modelled and an algorithm is proposed to select the most secure link based on the derived security metrics. The FSO links are modelled using exponential distribution considering different parameter values, thus exhibiting a strong atmospheric turbulent nature of the environment. Divergent environments and channel conditions tend to make the RF and FSO channels behave uniquely and complementary to each other. To attain high data rates along with higher reliability, RF and FSO links are incorporated together to form a hybrid FSO/RF communication system. The proposed algorithm is based on a security metric which is determined by computing the probability of strictly positive secrecy capacity (SPSC). Analytical closed-form expressions of SPSC have been obtained for the proposed system. Further, monte carlo simulations are performed to validate and confer the analytical results.
One of the fundamental issues in the field of wireless communication is security. To overcome this problem, hybrid radio frequency (RF)/free space optical (FSO) link with the presence of an eavesdropper present are modelled and an algorithm is proposed to select the most secure link based on the derived security metrics. The FSO links are modelled using exponential distribution considering different parameter values, thus exhibiting a strong atmospheric turbulent nature of the environment. Divergent environments and channel conditions tend to make the RF and FSO channels behave uniquely and complementary to each other. To attain high data rates along with higher reliability, RF and FSO links are incorporated together to form a hybrid FSO/RF communication system. The proposed algorithm is based on a security metric which is determined by computing the probability of strictly positive secrecy capacity (SPSC). Analytical closed-form expressions of SPSC have been obtained for the proposed system. Further, monte carlo simulations are performed to validate and confer the analytical results.
In this paper, the secrecy performance of the physical layer security (PLS) of the hybrid free-space optical/radio frequency (FSO/RF) communication system is analyzed. The transmission protocol of the considered system is performed under the eavesdropper's attempt to overhear the RF link between the transmitter and legitimate receiver of the hybrid system. The FSO link is characterized by Málaga-M distribution while the RF links are modeled by Nakagami-m distribution. The two practical eavesdropping modes considered in this paper include: colluding and non-colluding. Exact closed-form expressions for the system's secrecy outage probability (SOP), the asymptotic of the SOP (SOP∞), the probability of strictly positive secrecy capacity (SPSC), the average secrecy capacity (ASC), and the asymptotic of the ASC (ASC∞), are specifically derived under the influence of both eavesdropper modes. Our derived analytical expressions present an efficient tool to investigate the impact of some channel parameters on the secrecy performance, namely the fading severity of the RF links, atmospheric turbulence severity, pointing error of the FSO link, number of eavesdroppers, and the power of the eavesdropper links. The results show that the increase of the eavesdroppers' number under both modes profoundly degrades the considered system secrecy performance. The accuracy of the numerical results obtained is validated by Monte-Carlo simulations.
Hybrid Free-Space Optical (FSO) and millimeter Wave (mmWave) systems have emerged as a promising candidate for high data rate wireless transmissions due to the unique complementary properties against the different channel and environment conditions. Consequently, in this study, we investigate the hybrid FSO-mmWave systems from a physical-layer security point of view in the presence of different types of eavesdroppers, where the communication between two legitimate peers takes place over both FSO and RF links simultaneously. In particular, exponential atmospheric turbulence and Weibull fading channels are considered for FSO and mmWave links, respectively. We examine practical scenarios to eavesdrop the legitimate communication, and discuss the effects of random radio power of mmWave link and optical irradiance of FSO link on the probability of achieving a secure transmission. The impact of the fundamental physical layer parameters on the secrecy performance of the hybrid system is analyzed by obtaining analytical derivations of the probability of strictly positive secrecy capacity (SPSC) for different types of eavesdroppers, namely RF-, FSO- and Hybrid-Eve. In the light of results, we show that the analytical expressions are in exact agreement with the Monte-Carlo simulations.
Hybrid Free-Space Optical (FSO) and millimeter Wave (mmWave) systems have emerged as a promising candidate for high data rate wireless transmissions due to the unique complementary properties against the different channel and environment conditions. Consequently, in this study, we investigate the hybrid FSO-mmWave systems from a physical-layer security point of view in the presence of a hybrid type eavesdropper, where the communication between two legitimate peers takes place over both FSO and RF links simultaneously. We examine practical scenarios to eavesdrop the legitimate communication and discuss the effects of random radio power of mmWave link and optical irradiance of FSO link on the probability of achieving a secure transmission. The impact of the fundamental physical layer parameters on the secrecy performance of the hybrid system is analyzed by obtaining closed-form derivations of the probability of strictly positive secrecy capacity (SPSC) for correlated wiretap channels.
With the deployment of hybrid RF-FSO networks, there exists the potential to contribute significantly to the evolving landscape of 6G communication, as it effectively addresses challenges pertaining to connectivity, capacity, and security. In this paper, we study the secrecy performance of hybrid radio frequency (RF) - free space optical (FSO) systems in the presence of an eavesdropper. To improve the reliability of the source-destination transmission process, we consider a source that can transmit data via both RF and FSO links, simultaneously. Specifically, the RF links are exposed to generalized α – μ fading channels, while the FSO link is subject to Málaga distributions. Therefore, we deduce the novel analytical expression of secrecy outage probability and verify the results with the Monte Carlo simulations. The outcomes underscore the pronounced impact of fading parameters, receiver detection techniques, pointing errors, and atmospheric turbulence on security performance.
This paper investigates the secrecy performance for a decode-and-forward (DF) based mixed radio-frequency (RF) and free-space-optics (FSO) cooperative wireless network. The Rayleigh distribution is used to characterize the RF channel, similarly the turbulence effect in the FSO link is characterized by double-generalized-Gamma (DGG) distribution. The effect of pointing error is included during analysis. The closed form expressions of outage-probability for secrecy (SOP) and probability of non-zero secrecy capacity or strictly-positive-secrecy-capacity (SPSC) are analysed in terms of Meijer'G function. Finally all of the aforementioned results are verified via Monte-Carlo simulation.
In this paper, the physical layer security (PLS) analysis for a decode-and-forward (DF) protocol based multi-hop hybrid radio frequency (RF)/ free space optics (FSO) is presented. Herein, two different scenarios are considered for detecting the secured information at the destination. In the first scenario, at each hop, the received signals with higher secrecy capacity are selected. However, in the second scenario, the RF and FSO signals are simply decoded and forwarded to the next hop and selection is done at the last hop only. Each node in the system is connected to its subsequent node through parallel RF and FSO links. The FSO links and RF links are characterized by Málaga (M) and Nakagami-mcomposite distributions respectively. For both scenarios, the secrecy outage probability (SOP), strictly positive secrecy capacity (SPSC), intercept probability (IP), and effective secrecy throughput (EST) are obtained as performance metrics. These performance metrics are obtained by considering pointing error, different optical signal detection methods, turbulence effect, and the RF link fading parameter (m). Using the results, the security and reliability trade-off analysis is discussed for two scenarios. In addition, the asymptotic results are also obtained to study the system in depth. Further, the secrecy diversity order (SDO) and secrecy coding gain (SCG) are obtained to analyse the system in depth. Finally, Monte-Carlo Simulation is performed to verify the obtained results. The results manifest that the scenario with selection at each hop provides better secrecy performance than the scenario with selection at the last hop.