Optical wireless for intravehicle communications : incorporating passenger presence scenarios

Through the implementation of a simple linearly scalable 1-W infrared (IR) transmitter, which is centrally located on the ceiling of a sports utility vehicle (SUV), and for 15 passenger configurations, an analysis into the received power, power deviation, minimum bandwidth, and maximum root-mean-square (RMS) delay spread is provided for the regions of the vehicle most likely to benefit from the deployment of intravehicle optical wireless (OW) communication systems. Several specific regions, including the areas around a passenger's legs, arms, necks, and shoulders, are shown to have beneficial channel characteristics for the use of personal electronics equipment such as laptops, tablet PCs, or wireless headphones. Similarly, a region around the headrest of the front seat is shown to have potential for the deployment of in-car entertainment solutions independent of the passenger configuration. This analysis, which is the first to introduce the concept of channel variation from multiple passenger configurations, aims to show that OW is a potential candidate for future intravehicular communication systems

Investigation Of Optical Wireless For Employment Within A Vehicular Environment

The substantial increase in powerful electronic systems and functions has produced significant implications for the vehicular industry, where the amount of wiring infrastructure has increased the vehicle weight, weakened performance, and made adherence to reliability standards difficult. Eventually, connecting the electronics infrastructure was mostly complicated and costly in vehicular domain systems. Thus, little research has been conducted to explore appropriate wireless technologies that may be suitable with the emerging network standard within the context of vehicular networks. This thesis describes an in-depth investigation of deploying an optical wireless communication system within the vehicular environment, particularly in confined spaces. A wide variety of measurements has been performed using tubes of various materials and geometries, in a laboratory setup. The principle objective is to provide a primary knowledge of optical wireless channel characterization within a laboratory vehicular setting. The work presented is a study on directed line-of-sight (LOS) and non-LOS (NLOS) links, and focuses on frequency response, power efficiencies, and path losses in different experimental settings. Further, a variety of experimental settings was used in respect to different receiver/transmitter orientations and various bent tubes angles in order to investigate the channel conditions. The noise analysis, SNR, path loss and the eye pattern for the digital system prototype designed were also analysed. The system requirement for the LOS link were based on the transmission of the sinusoidal signal at a distance of 1 m with 13 MHz signal and approximately 15.6 dB SNR. Successful demonstration of the OWC within smaller size and high reflection coefficient material are promising. In addition to good transmitter and high sensitivity receiver. The NLOS link also demonstrated a good indication, both in straight tube with angled transmitter/receiver orientation and bend tubes. Detail studies on NLOS link with pulse signal transmission, which replicates a digital system transmission with 54.48 mW or 44.58 mW/cm2 output power,6 MHz signal transmission with the aim of 10-4 to 10-6 BER. Although, the operational functionality of digital system has successfully demonstrated, however achieving the desired BER is a bit difficult with the designed system. Further improvement on the highly sensitive receiver design, a proper modulation scheme is required in order to improve the quality of the transmitted signal in terms of SNR and BER. The study also suggested that the transmission within the metal tubes is better than in plastic tubes in addition to minimum bend angle, smaller tube diameter and high reflective coefficient. Transmission within 20 mm circular aluminium tube and 35 mm galvanised aluminium tube are the best so far. Finally, based on the initial viability results, it was seen that it is possible to implement an optical wireless communication infrastructure within the vehicular environment. Experimental validation of the system proposed shows that achieving high data rates is not a problem with the use of high brightness, high power LEDs as this system is going to be implemented within the vehicle chassis, thus the eye safety constraints should not be a limiting factor. Therefore, in this study, optical wireless transmission within the vehicular environment is proposed, solving the problems of vehicular networking systems

Visible Light Communication Cyber Security Vulnerabilities For Indoor And Outdoor Vehicle-To-Vehicle Communication

Light fidelity (Li-Fi), developed from the approach of Visible Light Communication (VLC), is a great replacement or complement to existing radio frequency-based (RF) networks. Li-Fi is expected to be deployed in various environments were, due to Wi-Fi congestion and health limitations, RF should not be used. Moreover, VLC can provide the future fifth generation (5G) wireless technology with higher data rates for device connectivity which will alleviate the traffic demand. 5G is playing a vital role in encouraging the modern applications. In 2023, the deployment of all the cellular networks will reach more than 5 billion users globally. As a result, the security and privacy of 5G wireless networks is an essential problem as those modern applications are in people\u27s life everywhere. VLC security is as one of the core physical-layer security (PLS) solutions for 5G networks. Due to the fact that light does not penetrate through solid objects or walls, VLC naturally has higher security and privacy for indoor wireless networks compared to RF networks. However, the broadcasting nature of VLC caused concerns, e.g., eavesdropping, have created serious attention as it is a crucial step to validate the success of VLC in wild. The aim of this thesis is to properly address the security issues of VLC and further enhance the VLC nature security. We analyzed the secrecy performance of a VLC model by studying the characteristics of the transmitter, receiver and the visible light channel. Moreover, we mitigated the security threats in the VLC model for the legitimate user, by 1) implementing more access points (APs) in a multiuser VLC network that are cooperated, 2) reducing the semi-angle of LED to help improve the directivity and secrecy and, 3) using the protected zone strategy around the AP where eavesdroppers are restricted. According to the model\u27s parameters, the results showed that the secrecy performance in the proposed indoor VLC model and the vehicle-to-vehicle (V2V) VLC outdoor model using a combination of multiple PLS techniques as beamforming, secure communication zones, and friendly jamming is enhanced. The proposed model security performance was measured with respect to the signal to noise ratio (SNR), received optical power, and bit error rate (BER) Matlab simulation results

Enhanced Optical Wireless Channel For Indoor And Intravehicle Communications: Power Distribution And Signal To Noise Ratio Analysis

Visible light communication—(VLC) provides wide bandwidth and high security capabilities for free space optical communication. This thesis presents the key concepts, underlying principles and practical applications of visible light communications. In particular, this thesis focuses on the received power distribution pattern and signal to noise ratio for line-of-sight indoor and vehicular applications. Several methods are used to modify the SNR and power distribution levels. It is shown that in the absence of obstruction, the optical footprint is nearly circular and offers a platform for large- scale deployment in commercial environments, which is similar to micro and Pico cells. By studying various kinds of commonly used VLC channel analysis: diffuse and line of sight channels, a simple improved indoor and intra-vehicular VLC transmission model for power distribution and SNR is presented. Employing optical wireless communications within the vehicle not only enhances user mobility, but also alleviates radio frequency interference, and lowers system cost through the utilization of license free spectrum. Moreover, a solution to increase the received power by changing the semi angle at half power is presented. The simulation results show the improved received power distribution and SNR. A VLC system, based on color-shift-keying (CSK) modulation and code-division multiple-access (CDMA) is presented. CSK–CDMA VLC system is used to enhance the VLC system capacity and mitigate single color light interference, which allows multiple users to access the network

Analysis of Energy Consumption Performance towards Optimal Radioplanning of Wireless Sensor Networks in Heterogeneous Indoor Environments

In this paper the impact of complex indoor environment in the deployment and energy consumption of a wireless sensor network infrastructure is analyzed. The variable nature of the radio channel is analyzed by means of deterministic in-house 3D ray launching simulation of an indoor scenario, in which wireless sensors, based on an in-house CyFi implementation, typically used for environmental monitoring, are located. Received signal power and current consumption measurement results of the in-house designed wireless motes have been obtained, stating that adequate consideration of the network topology and morphology lead to optimal performance and power consumption reduction. The use of radioplanning techniques therefore aid in the deployment of more energy efficient elements, optimizing the overall performance of the variety of deployed wireless systems within the indoor scenario

Orientation Effects For LOS And NLOS OWC Characterisation Within Small Structures

This paper reports an experimental investigation of the orientation effect towards optical wireless channel parameters within small structures.The experiment has characterised the orientation effect of the line-of-sight (LOS)and non-line-of-sight (NLOS) infrared transmission when using different material and geometrical properties on significant infrared channel parameters.Two measurement setups were used,(1) the straight guiding structures,and (2) bending guiding structures,with three different bending angles (30o,45o and 60o bend).In each of the measurement,the receiver/transmitter is rotated in the steps of 15˚ each time.The results revealed that the characteristic of the channel depends on the physical geometries,the orientation of the transmitter/receiver and also depend on reflection coefficient of the materials.The results are valid for both LOS and NLOS transmission

Orientation Effects for LOS and NLOS OWC Characterisation Within Small Structures

This paper reports an experimental investigation of the orientation effect towards optical wireless channel parameters within small structures. The experiment has characterised the orientation effect of the line-of-sight (LOS) and non-line-of-sight (NLOS) infrared transmission when using different material and geometrical properties on significant infrared channel parameters. Two measurement setups were used, (1) the straight guiding structures, and (2) bending guiding structures, with three different bending angles (30o, 45o and 60o bend). In each of the measurement, the receiver/transmitter is rotated in the steps of 15˚ each time. The results revealed that the characteristic of the channel depends on the physical geometries, the orientation of the transmitter/receiver and also depend on reflection coefficient of the materials. The results are valid for both LOS and NLOS transmission

Experimental Study of Straight Guiding Structures for Optical Wireless Communications Within a Vehicular Environment

Generous increments in powerful electronic systems and functions have produced significant implications for the vehicular industry, especially in connecting the electronics infrastructure as it is complicated and costly. A limited amount of research has been conducted to investigate proper wireless advancements that might reasonable with the emerging network standard within the context of intravehicular networks. This paper reports an experimental investigation of Optical Wireless Communication (OWC) links within guiding structures for a vehicular environment. The experiment has characterized the infrared transmission characteristics using different types of materials and the influence of the geometry on significant infrared channel parameters. The upper and lower 3-dB frequencies for line of sight (LOS) transmission in the tubes demonstrate that the tubes do not significantly change the frequency response of the transmission but this rather depends on the other channel factors such as materials and geometry

Design and Experimental Evaluation of a Database-Assisted V2V Communications System Over TV White Space

Automakers are increasingly employing wireless communications technologies into vehicles, which are expected to be one of the primary tools to improve traffic flow and traffic safety. Anticipating a significant increase in the accompanying spectrum and capacity requirements, in this paper, we speculate about using dynamic spectrum access in general, and TV white space in particular for vehicular communications. To this end, we describe the concept, design, general architecture and operation principles of a vehicle-to-vehicle communications system over TV white space. This system makes dual use of a geolocation database and spectrum sensing to understand spectrum vacancies. In this architecture, whenever a database query result is available, that information is prioritized over sensing results and when the database access is disrupted, vehicles rely on the spectrum sensing results. After describing the general concepts, we numerically analyze and evaluate the benefits of using proxy vehicles for geolocation database access. Finally, we present the middleware-centric implementation and field test results of a multi-hop vehicle-to-vehicle communications system over the licensed TV-band. We present results regarding multi-hop throughput, delay, jitter, channel switching and database access latencies. This study complements our previous work which described spectrum sensing based vehicle-to-vehicle communications design and testing