In this article, we investigate the physical layer security in an indoor environment, wherein both visible light communication (VLC) as well as radio frequency (RF) technologies are codeployed. We explore the benefits of employing both technologies by imposing a limit of positive secrecy rate to prevent the eavesdropping attacks, which is an important metric in designing a secure wireless network. The VLC technology is used as a primary technology and the RF technology is used when the primary technology cannot satisfy the imposed limit. In particular, a novel secure-link selection mechanism is proposed to select the secure technology (i.e., either VLC or RF technology) based on the availability or nonavailability of instantaneous channel state information of both legitimate and eavesdropping links. The performance of the system is evaluated in terms of average secrecy capacity, connection outage probability, and secrecy outage probability. We observe the effect of various physical parameters on the security performance of the network. Further, analytical results are corroborated with the computer simulation results.
The physical layer security analysis is required in visible light technology based optical wireless communication networks, in order to deal with the eavesdropping attacks. In this study, we consider an indoor VLC network consisting of two light emitting diode elements. Further, based on ability to negate the eavesdropping attacks, the source transmitter selects either of the element to transmit the information to the legitimate user in the presence of an eavesdropper. In particular, for the selection of the element with desired ability, we propose a two-stage secure link adaptation scheme. We develop a mathematical framework to analyse the average secrecy capacity and secrecy outage probability of both single-element and dual-element VLC links. Further, we compare the numerical results of the proposed dual-element VLC network with the conventional single-element VLC network by varying physical parameters.
This paper evaluates the secrecy outage probability of a hybrid radio frequency (RF) and visible light communication (VLC) network in the presence of an eavesdropper.We assume that data is transmitted over the RF and VLC links following a proposed multiplexing scheme in which the data sent by the source is split with a certain allocation ratio.Furthermore, the legitimate and eavesdropper users are assumed to have multihoming capabilities, so that they are able to receive data from both RF and VLC access points, simultaneously.We derive integral-form exact expression, as well as a closedform asymptotic expression for the secrecy outage probability and validate them via Monte Carlo simulations.Our results show that multiplexing the information signal by both links leads to an enhancement of the secrecy performance since it opportunistically takes advantages of the best characteristics of both domains.
In this article, the secrecy performance of a hybrid radio frequency (RF)/visible light communication (VLC) system is studied. In this hybrid system, the source node (i.e., Alice) transmits information to the relay node via the outdoor RF link. Nakagami-m fading and path loss are considered for the RF link. The relay node includes an outdoor component and an indoor component, which are connected by using a wired medium. The outdoor component receives and recovers information by using the decode-and-forward (DF) relaying scheme and then transmits it to the indoor component. The indoor component then converts the received electrical signal into an optical signal by using a light-emitting diode. A legitimate receiver (i.e., Bob) deployed on the floor receives the optical signal. An eavesdropper (i.e., Eve) deployed in the RF or VLC link wiretaps the confidential information. In this study, we use the secrecy outage probability (SOP) and the probability of strictly positive secrecy capacity (SPSC) to evaluate the system performance. We then obtain the closed-form expression for a lower bound on the SOP and an exact closed-form expression for the probability of SPSC when the RF and VLC links are wiretapped, respectively. Numerical results are presented to validate the accuracy of our derivations. We further discuss the effects of the noise standard deviation, the equivalent threshold of the signal-to-noise ratio, and the floor radius on the system secrecy performance when the VLC link is eavesdropped upon. For the case when the RF link is eavesdropped upon, the impacts of the distance between Alice and the relay, the path loss exponent, the fading factor, and the distance between Alice and Eve on secrecy performance are also provided.
This letter studies the security performance of hybrid radio frequency (RF) and visible light communication (VLC) system. In this hybrid system, the source node (i.e., Alice) transmits information to the relay node via the outdoor RF link. Nakagami-m fading and path loss are considered for the RF link. The relay using the decode-and-forward (DF) relaying scheme. A legitimate receiver (Bob) arranged on the floor receives the optical signal. An eavesdropper (Eve) deployed in VLC link wiretaps the confidential information. In this paper, secrecy outage probability (SOP) is used to assess the performance of the system. We derive the closed expression of the lower bound of SOP when VLC link is wiretapped. Numerical results to validate the accuracy of our derivation.
In this paper, a cooperative hybrid visible light communication (VLC)-radio frequency (RF) system with spatially random terminals is considered. Especially, a source node (
S) with a group of light-emitting diode (LED) lamps transmits information bits to a destination (
D), which is located out of
S’s coverage area, via a relay node (
R).
Ris equipped with a photodetector and an antenna to set up a VLC link between
Sand
R, and a radio frequency (RF) link between
Rand
D, respectively. Meanwhile, an eavesdropper (
E) equipped with a photodetector and an antenna tries to overhear the information delivery over VLC and RF links. Also, diversity receiving scheme is considered at
E, while the same modulation scheme is considered over both VLC and RF links. Furthermore, decode-and-forward scheme is adopted at
Rto process and forward the received VLC signals. By employing stochastic geometry, we first characterize the probability density function and cumulative distribution function of the received signal-to-noise-ratio over both VLC and RF links, while considering the randomness of the locations of both
R,
E, and
D. Then, the secrecy performance of the target system is studied by deriving the approximated expressions for the secrecy outage probability under various cases. Finally, the proposed analytical models are verified via Monte-Carlo simulations.