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This paper presents a study of a 32×10 Gbps Radio over Fiber and Wavelength Division Multiplexing (RoF-WDM) full-duplex system that uses Phase Modulators and a Dual-Port Mach-Zehnder Modulator (PMs-DPMZM) for bidirectional data transfer. The system employs Millimeter-Wave (MMW) signaling over optical fiber and focuses on selecting a technology that provides high transmission capacity per wavelength, improved spectral efficiency, and resistance against optical transmission impairments. The proposed method was validated using simulation results to confirm the efficiency of the proposed system in generating a 40 GHz signal and efficiently detecting and modulating the RF signals. The results demonstrate that the system exhibits strong resistance against dispersion, non-linear effects, and noise, delivering satisfactory performance for distances of up to 220 km. By analyzing the input power, the paper establishes a relationship between input power and signal quality, revealing that an optimal power of 0 dBm leads to an improved Quality Factor (QF) and reduced transmission errors. Furthermore, the evaluation of received optical power indicates the power level required to maintain an acceptable error rate, approximately -20.9690 dBm for downstream data transfer and -20.7245 dBm for upstream data transfer at the BER limit. The simulation performance also demonstrates the transmission efficiency achieved through a high Polarization Mode Dispersion (PMD) coefficient of up to 0.8. The analytical calculations conducted in this work provide valuable insights for optimizing and enhancing the performance of RoF-WDM networks.

The security landscape of Internet of Things (IoT) networks continues to draw significant attention from recent networks; the Version Number Attack (VNA) stands out as a prominent threat to IoT network resources. Routing Protocol for Low-Power and Lossy Network structures low-power and lossy networks through one or more Destination Oriented Directed Acyclic Graphs (DODAGs). Each DODAG is assigned a version number, serving the purpose of ensuring the existence of loop-free paths to the root node. In the event of any inconsistency detected by the root node, the version number is incremented, triggering a global repair process and the reconstruction of the Directed Acyclic Graph. A potential security concern arises when a malicious node advertises a false version number in its control message, compelling the initiation of a global repair process. This study conducts a comprehensive analysis of the VNA’s impact, considering various parameters that have not been explored in previous research articles. These parameters include an examination of the additional forwarding tasks introduced by the attack and an exploration of factors contributing to node hyperactivity (such as loops, local and global repairs, etc.). The article delves into the specific control messages that result in the detrimental effects of the attack, offering a detailed analysis of control overhead, energy consumption, Packet Delivery Ratio, and latency. The obtained results show that the DAO (Destination Advertisement Object) messages dominate the total control overhead and are the main contributor to the total consumer energy, where the closest the malicious node to the sink the more damaging is the attack.

In this paper, a comparative experimental analysis of Free space Optical communication systems using On Off Keying (OOK), Pulse Position Modulation (PPM) and Multiples Pulse Position Modulation (MPPM) modulation techniques is presented. The experiments have been carried out under controlled Fog channel. The investigated communication channel is deployed within a controlled chamber of 5.5m length, where the laser source is modulated using the above-mentioned modulation schemes. The received signal is studied and analyzed to measure the effect of Fog on the optical beam carrying information. The eye-diagram, signal distribution and bit error rate (BER) are analyzed for comparative studies. [ABSTRACT FROM AUTHOR]

The prediction of the Quality of Service is a vital key in the deployment of Free Space Optical communications networks, it depends on a variety of factors, including equipment reliability, network design and atmospheric parameters such as rain, snow, fog and scintillation. The aim of this paper is to present a quality-of-service software provisioning for wireless optical networks, which allows predicting the availability of a FSO link. Compared to software developed in this area, the proposed software provides instantaneous prediction as well as long-term prediction, and it takes into account the case where the FSO units are implemented behind windows. The FSO software includes different effects (geometric attenuation, atmospheric molecular absorption, fog, rain, snow, sunlight and scintillation), it consists of a Graphic User Interface (GUI) and a calculating kernel. [ABSTRACT FROM AUTHOR]

The present study aims to assess the impact of alfa and date palm natural fibers as reinforcement for epoxy, vinyl ester, and polyimide polymer (Alfa-Date palm/epoxy, Alfa-Date palm/vinyl ester, and Alfa-date palm/polyimide) through a genetic approach. The study employs a genetic simulation rooted in the Weibull formalism, employing genetic operators such as selection, crossing, and mutation for a nuanced evaluation of the damage at the fibermatrix interface across the studied materials. The genetic algorithm results authentically capture the intrinsic behaviour of these materials, emphasising key mechanical properties like Young's Modulus, deformation, and stress at break. The obtained results highlight that the matrix showing the highest Young's modulus value at its fiber-matrix interface exhibits superior strength. These conclusions align with contemporary advancements in natural fiber-reinforced composite materials tailored for diverse industries and eco-friendly applications. [ABSTRACT FROM AUTHOR]

IoT networks are witnessing a rapid growth in various domains of our daily life, offering more attractive features in terms of measurement accuracy, easy implementation and affordable deployment costs. This outstanding boom is not undoubtedly far away from different challenging issues that impede the network efficiency and quality. The security concern remains one among the prominent issues that affect both the edge and the core IoT network where risks increase in conjunction with the network expansion. RPL is the well-known routing protocol for the edge part of the IoT network, intended to meet the requirements of the constrained IoT devices. Despite its various advantages, RPL remains suffering from various security attacks targeting the topology, the traffic, and the nodes resources. Our work presents a new silent decreased rank attack against RPL-Contiki, as well as a lightweight countermeasure. The obtained results on a random studied topology show that almost half the existing nodes in the topology were attracted by the planted malicious node, through its falsified low rank. Moreover, an increase of 12.5% in the control overhead and an increase of 15% in the total consumed energy are recorded compared to the attack-free topology. On the other hand, the attack did not heavily affect the PDR, but the latency showed an increase of 45% compared to the attack free case. This damaging effect makes this modified rank attack a serious threat to IoT RPL based networks. [ABSTRACT FROM AUTHOR]

The present work describes a new technique to mitigate the version number attack (VNA), which is classified as one among the known denial of service (DDoS) damaging attacks targeting RPL-based (Routing Protocol for Low Power and Lossy Networks) IoTs networks. Through a VNA, the malicious behavior induces an increase in the control overhead and affects nodes' ressources in terms of processing and memory, thereby the network availability is directly targeted. The lightweight proposed algorithm is run by each node where the main purpose is to halt the spread of a faked version number over the network and to recover victim nodes. The proposed solution has been implemented and simulated using Cooja under Contiki OS. Simulation results obviously show that our proposed technique promises significant improvements in various measured metrics while optimizing the node resources in terms of processing and memory usage. Compared to the network under attack, the control overhead has been shortened by 83% and the energy consumption has been reduced by 74%. In addition, the packet delivery ratio (PDR) has been improved to reach (99,6%), and the latency has been restored to attain the same value as in the normal case. [ABSTRACT FROM AUTHOR]

Synchronized multi-pulse PPM “SMPPM" is a new proposed modulation scheme based on MPPM proposed for wireless optical systems. The proposed scheme resolves the symbol synchronization problem which may simplify the encoding and the decoding operations. It shows an important improvement in terms of data speed and bandwidth efficiency compared with conventional MPPM. On the other hand, SMPPM modulation shows a moderate power efficiency. In this article, we present the coding algorithm, expressions of spectral efficiency, normalized power requirements, and the data rate normalized to PPM, and we also present comparison of results with conventional MPPM. [ABSTRACT FROM AUTHOR]

Current research efforts are directed towards utilizing polymers and biodegradable materials to develop innovative wireless devices for emerging applications within the sub-6 GHz spectrum. This study seeks to enhance the electrical and radiation characteristics of antennas while ensuring favorable environmental properties such as flexibility and Specific Absorption Rate (SAR). To this end, a comparative analysis of two flexible rectangular microstrip antennas constructed from novel polymer-based substrates is presented. One antenna uses a flexible composite substrate of polydimethylsiloxane (PDMS) embedded with carbon nanotubes (CNT), while the other employs a biodegradable polymer composite substrate made of polycaprolactone (PCL) reinforced with CNT. Results indicate that the PCL-CNT antenna surpasses the PDMS-CNT antenna in performance, in both flat and bent conditions. Specifically, at 2.4 GHz, the PCL-CNT antenna achieved a gain of 4.46 dBi and an efficiency of 0.70, compared to a gain of 3.94 dBi and an efficiency of 0.61 for the PDMS-CNT antenna. Furthermore, the superior performance of the PCL-CNT biodegradable polymer composite antenna suggests its potential for IoT applications and wireless communications, combining effective on-body usage with minimal environmental impact. [ABSTRACT FROM AUTHOR]