Vehicle Safety Communication Research Articles

Hybrid RF/VLC Systems: A Comprehensive Survey on Network Topologies, Performance Analyses, Applications, and Future Directions

Wireless communications refer to data transmissions in unguided propagation media through the use of wireless carriers such as radio frequency (RF) and visible light (VL) waves. The rising demand for high data rates, especially, in indoor scenarios, overloads conventional RF technologies. Therefore, technologies such as millimeter waves (mmWave) and cognitive radios have been adopted as possible solutions to overcome the spectrum scarcity and capacity limitations of the conventional RF systems. In parallel, visible light communication (VLC) has been proposed as an alternative solution, where a light source is used for both illumination and data transmission. In comparison to RF links, VLC links present a very high bandwidth that allows much higher data rates. VLC exhibits also immunity to interference from electromagnetic sources, has unlicensed channels, is a very low power consumption system, and has no health hazard. VLC is appealing for a wide range of applications including reliable communications with low latency such as vehicle safety communication. Despite the major advantages of VLC technology and a variety of its applications, its use has been hampered by its cons such as its dependence on a line of sight connectivity. Recently, hybrid RF/VLC systems were proposed to take advantage of the high capacity of VLC links and better connectivity of RF links. Thus, hybrid RF/VLC systems are envisioned as a key enabler to improve the user rates and mobility on one hand and to optimize the capacity, interference and power consumption of the overall network on the other hand. This paper seeks to provide a detailed survey of hybrid RF/VLC systems. This paper represents an overview of the current developments in the hybrid RF/VLC systems, their benefits and limitations for both newcomers and expert researchers.

Block Chain Based Security Mechanism for Internet of Vehicles (IoV)

A combination of Internet of Things (IoT) and mobile internet has led to the inescapable development of Internet of Vehicles (IoV). The technology encompasses connected vehicle services like vehicle management, infotainment, driving assistance, safety, traffic management and data communication between nodes. Efficient communication between nodes can prevent many mishaps and can save lives. For instance, in the case of a road accident, the nearby emergency services are contacted immediately along with the nodes. They are either re-routed or are made to make way for the emergency vehicles. Hence, it is very important to include only the authenticated nodes in the network in order to prevent malicious activities like tampering the emergency message or sending false information. In this paper, we present an authentication and secure data transfer algorithm, in the IoV framework using the promising and evolving blockchain technology, to assure true information communication between the nodes. We also introduce blockchain in some of the connected car services to improve the efficiency.

Directed broadcasting with mobility prediction for vehicular sensor networks

This article suggests a new directed broadcasting method with mobility prediction of moving vehicles in vehicular sensor networks (VSNs). VSNs can play a critical role to ensure prompt delivery of real-time sensing data and be able to prevent various road dangers. The suggested method is particularly for vehicle safety communication (VSC) on highway roads by using directed broadcasting between vehicles. In VSNs, broadcasting is the most suitable communication mechanism for VSC. The simplest broadcasting mechanism is flooding, which introduces the redundant message retransmission and the broadcast storm problem. It is because all vehicles rebroadcast the messages in flooding. The broadcast storm problem can be addressed with selective flooding schemes which select rebroadcast vehicles to perform rebroadcasting. However, selective flooding schemes cannot promise enough reliability for VSC because of the highly dynamic topology and frequent disconnections of vehicular networks. Fast movement and frequent topology changes cause repeated link breakages and it increases the packet loss rate of vehicular networks. In this article, we propose a mobility prediction-based directed broadcasting (MPDB) protocol to achieve a reliable broadcasting in VSNs. MPDB protocol broadcasts emergent messages only to the rear vehicles on the same road. MPDB protocol consists of two phases: (i) mobility prediction phase and (ii) broadcasting phase. The mobility prediction can be acquired through periodical beaconing. In mobility prediction phase, each vehicle gets its rear vehicle set on the same road through neighbour’s position, inter-vehicle distance, relative speed and moving direction. In broadcast phase, MPDB protocol selects a vehicle having the largest link available time (LAT) values acquired by the mobility prediction as a rebroadcast vehicle among the rear vehicle set acquired in previous phase. By using LAT for broadcasting propagation, MPDB protocol can intensify the reliability of the message dissemination and also prevent the broadcast storm problem in vehicular networks. The simulation results show that MPDB protocol has better performance improvement in terms of average packet rate and packet delay.

Co-Simulation of Cooperative Vehicle Safety Applications and Communication Networks

Co-Simulation of Cooperative Vehicle Safety Applications and Communication Networks

Density-Aware Rate Adaptation for Vehicle Safety Communications in the Highway Environment

In this letter, we propose a density-aware rate adaptation (DARA) protocol to ensure reliable vehicle safety communication in a highway broadcast environment. DARA significantly improves system reliability by addressing the challenges of estimating channel conditions caused by various dynamics due to factors, including channel fading, interference, and varying traffic density. One salient advantage of DARA is that it can estimate the average packet loss rate for each sender locally without the use of any control frames (such as ACK and RTS/CTS). DARA can also distinguish the interference losses from the fading losses based on an empirical model. It adjusts the bit rate only in response to the packet loss due to channel fading and the change of the traffic density. Simulation results demonstrate that DARA can provide reliability guarantees for vehicle safety communication.

Fault Detection for Vehicular Ad Hoc Wireless Networks

An increasing number of intelligent transportation applications require robust and reliable wireless ad hoc communication. The process of communicating using radio requires a series of software and hardware modules to be functioning correctly. For many vehicle safety and automation applications communication is relied upon to the point where undetected faults can result in potentially dangerous situations, for example if a warning cannot be given in time to prevent a collision. The consequence of problems with any of the network components can be a partial or complete loss of radio communication. Generally, most systems will consider network failure when there is no communication, but this overlooks problems where a partial fault causes degradation in the communication performance. There is a fundamental requirement to detect and respond to the partial failure of a network to ensure that communication is not intermittent, or performs poorly after a certain range. The partial loss of communication is difficult to detect, and is often overlooked in mobile ad hoc network applications. This paper introduces a novel method for modeling the antenna performance using collected data, and using the model to determine the probability that an antenna has some level of performance degradation.

Implementation of VANET-based Warning Generation System using Cellular Networks, GPS, and Passive RFID Tags

Vehicular communication systems are a key part of an intelligent transportation system, while vehicle safety communication is a major target of vehicular communication. Other features that augment vehicular ad hoc networks are enhanced driving experience, including but not limited to, active navigation and weather information, real-time traffic information and a plethora of other autonomous and automated systems. However, our focus will be warning generation systems, which can help reduce fatalities if deployed in an efficient and fail-safe manner on motorways and highways. This paper describes a collective information system for collection and delivery of traffic information aimed at supporting fast, efficient and secure travel of people and transport of goods. Based on that information, authorities are able to assess vehicles’ sudden motion and movement changes and can generate warning/alert messages (for emergency/police vehicles) for post-accident scenarios. In this paper, the use of a radio frequency identification (RFID) system for vehicular communication has been proposed and an extended RFID system and infrastructure for vehicle safety communication through emergency phone towers (EPTs) and cell phones is suggested. In order to communicate, vehicles may be equipped with a cellular phone, RFID, and/or a global positioning system (GPS), whereas RFID readers may be mounted on EPTs, which are already installed on motorways. It also provides a demonstration on flow of information within the system; the simulation results are also included.

A Study on Efficient Vehicular Safety Message Broadcast Scheme using GPS Information in VANET

In Vehicle Safety Communication (VSC), noted as a representative application of VANET technologies, emergency warning messages (EWM) are broadcast over vehicles in response to an emergency situation. However, as the number of vehicles increases, the so-called Broadcast Storm Problem often occurs due to a huge number of redundant EWM transmitted. Though many approaches in the literature have been proposed to solve the problem, most of them require the preliminary phase for setting up or refreshing neighbor relationship through exchanging beacon messages with nearby vehicles, thereby further increasing the traffic load. In this paper, we propose Longest Leaping Relay (LLR) scheme which can efficiently solve the Broadcast Storm Problem without any preliminary phase for setting up neighbor relationship. Through computer simulations, we compared the performance of the proposed scheme with competitive schemes and verified the proposed scheme outperforms the existing schemes.

Context awareness beacon scheduling scheme for congestion control in vehicle to vehicle safety communication

Vehicle safety applications based on vehicle to vehicle communication typically transmit safety-related beacons to all neighboring vehicles with high reliability and a strict timeline. However, due to high vehicle mobility, dynamic network topology and limited network resource, this periodic beaconing could lead to congestion in the communication network. Therefore, beacon transmission method has a special challenge to efficiently use the limited network resources to satisfy the requirements of safety applications. With this motivation, we propose a novel distributed beacon scheduling scheme referred to as the context awareness beacon scheduling (CABS) which is based on spatial context information dynamically scheduling the beacon by means of TDMA-like transmission. The proposed beacon scheduling scheme was evaluated using different traffic scenarios within both a realistic channel model and IEEE 802.11p PHY/MAC model in our simulation. The simulation results showed that the performance of the CABS scheme was better than periodic scheduling in terms of packet delivery ratio and channel access delay. Also, the CABS scheme satisfies the requirements of the safety applications.

Field evaluation of UHF radio propagation for an ITS safety system in an urban environment

Roadside-to-vehicle and vehicle-to-vehicle communication systems have been proposed as part of ITS development to help achieve vehicle safety and realize more secure road traffic environments. In this article we first introduce several typical applications and their radio range requirements for vehicle safety communication systems to clarify the technical point of view. Then we show some field experiment results in an urban area in Tokyo to investigate and verify the radio propagation characteristics and the quality of communications by using a wireless radio prototype system. Finally, we conclude that the current prototype system has potential to fulfill the radio range requirements of vehicle safety communications, but there are still lots of issues that need to be addressed.

Surveillance, Privacy and the Ethics of Vehicle Safety Communication Technologies

Recent advances in wireless technologies have led to the development of intelligent, in-vehicle safety applications designed to share information about the actions of nearby vehicles, potential road hazards, and ultimately predict dangerous scenarios or imminent collisions. These vehicle safety communication (VSC) technologies rely on the creation of autonomous, self-organizing, wireless communication networks connecting vehicles with roadside infrastructure and with each other. As the technical standards and communication protocols for VSC technologies are still being developed, certain ethical implications of these new information technologies emerge: Coupled with the predicted safety benefits of VSC applications is a potential rise in the ability to surveil a driver engaging in her everyday activities on the public roads. This paper will explore how the introduction of VSC technologies might disrupt the "contextual integrity" of personal information flows in the context of highway travel and threaten one's "privacy in public." Since VSC technologies and their related protocols and standards are still in the developmental stage, the paper will conclude by revealing how close attention to the ethical implications of the remaining design decisions can inform and guide designers of VSC technologies to create innovate safety applications that increase public safety, but without compromising the value of one's privacy in public.