Design of NS3 VLC module and performance analysis of ad hoc network under VLC and Wi‐Fi layers

Abstract

Visible light communication (VLC) is the branch of optical wireless communi-cations that uses light-emitting diodes for the dual purpose of illumination and very-high-speed data communication. The main motivation behind the current work is finding alternatives to the saturated radio frequency spectrum, radio frequency security issue, and vulnerability to interferences. The current work is aimed at developing a module for the physical layer of a VLC-based ad hoc network in network simulation 3. The VLC physical layer module is developed by using the optical signal modules available in the network simulator.The work also includes modelling of VLC-based transmitter, wireless optical channel, and the optical receiver. Furthermore, the implementation and evaluation of the VLC-based physical layer is carried out over a typical ad hoc network under different performance metrics. The designed ad hoc network is also tested under Wi-Fi module followed by its comparison with corresponding ad hoc network under VLC module. The comparison is based on bit error rate curves, system throughput, and gain in received signal-to-noise ratio mainly.Finally, the suitability of different modulation schemes is also investigated in the current work for both Wi-Fi-and VLC-based ad hoc networks. KEYWORDS ad hoc networks, bit error rate (BER), Li-Fi, modulation SCHEMES, network simulator, NS3, OOK, PAM, PHY layer, throughput, visible light communication (VLC), VPPM, 5G mobile communication | INTRODUCTIONIn the past decade, there has been a drastic increase in the demand for high-speed data communication services (cellular networks, smart TVs, cloud-based computing, high-definition video calling, and live streaming). The existing radio frequency (RF) wireless technologies have been the forefront of telecommunication, revolutionizing the voice and data communication. 1 However, because of saturation of RF spectrum, security issues, vulnerability to interferences, and hazards of RF, low-cost and reliable technologies are required to provide efficient data communication. The discovery and growing use of light-emitting diodes (LEDs) have boosted the research in visible light communication (VLC) technology. 2 Visible light communication is becoming an emerging green technology aimed to providing high data rates for short-range communication and easy deployment in hospitals, planes, and areas where traditional RF systems are less preferred. 3 The VLC salient features include license and interference-free spectrum (430THz-790THz), extremely large bandwidth, inherent security, compatibility with existing technologies, and high efficiency for positioning purposes due to its line-of-sight (LoS) feature. 4

Time Difference of Arrival Based Indoor Positioning System Using Visible Light Communication

“…The high transmission speed, safety, low energy consumptions and operating in restricting environments, all provide an edge to VLC over the standard Wireless communication technologies [4]. It is worth-mentioning that although VLC links are very reliable due to the noninterference of RF signals, yet Low Density Parity Check (LDPC) codes are, in general, able to achieve the capacityapproaching performance of a myriad of communication systems.…”

“…The first objective is to model an VLC based channel in Ns-3, via mathematical modelling of its various real-time components [42,4]. More details about VLC module implementation can be found in [4].…”

“…The performance for the VLC module is tested on the basis of BER and Signal-to-Noise-Ratio (SNR) calculation at least under Variable pulse position modulation (VPPM) modulation scheme. The channel parameters, taken as standard values and implemented, are given in Table I [4,3,42]. The Performance results are given both in analytical and graphical forms for both the LoS and NLoS channel models.…”

“…Other salient features include non-penetration to walls, cost effectiveness, vast spectrum of communication, no interference with RF spectrum (430-790THz), and high resolution for localization applications [3]. The communication over a VLC link is highly secure for covert communication due to opacity hindrance because VLC signal cannot pass through walls and other opaque materials.The high transmission speed, safety, low energy consumptions and operating in restricting environments, all provide an edge to VLC over the standard Wireless communication technologies [4]. It is worth-mentioning that although VLC links are very reliable due to the noninterference of RF signals, yet Low Density Parity Check (LDPC) codes are, in general, able to achieve the capacityapproaching performance of a myriad of communication systems.…”