Intelligent Transportation System Communication Research Articles

Intelligent firefly-based algorithm with Levy distribution (FF-L) for multicast routing in vehicular communications

Vehicular ad hoc network (VANET) is an interesting technology used to attain inter-vehicle communication in intelligent transportation system (ITS). In VANET, the timely and unfailing vehicular communication is an important challenge to achieved good service. So, efficient routing techniques are highly needed for proper data transmission in VANET. In this paper, we concentrate on the quality of service (QoS) constrained multicast routing problem by considering it as an NP-complete problem. Several studies reported that bio-inspired algorithms work well than the traditional algorithms to resolve the NP-complete problem. So, a firefly with Levy distribution (FF-L) algorithm is presented to manage the multicast routing problem. To prevent the FF algorithm stuck into local optima, Levy distribution is incorporated to the FF algorithm. The FF-L algorithm for multicasting routing in VANET is validated using a set of experiments on three different scenarios. The experimental values verified that the FF-L algorithm identifies the optimal routes and it can be implemented in practical scenarios where the network structure remains quite stable.

Modeling and analysis of LTE connectivity in a high mobility vehicular environment

Long-Term Evolution (LTE) technology has several features that make it an attractive alternative to be used in vehicle-to-infrastructure communications for intelligent transportation systems. However, before LTE can be widely used in this context, a number of analyses must provide convincing evidence that critical network functions (e.g. resource allocation strategies) yield adequate performance. To this end, in this work, we introduce a Markov-chain based model for LTE downlink channel quality, a prime factor affecting performance. Our model comes from the analysis of a large number of measurements of LTE Cell-Specific Reference Signals that were collected through a crowdsourcing application on a motorway in the UK. The model is intended to be used in performance evaluation studies and we exemplify its use with a case study, where we estimate the downlink transmission capacity of an LTE network. We also discuss other potential applications.

Guest Editorial Introduction to the Special Issue on Dependable Wireless Vehicular Communications for Intelligent Transportation Systems (ITS)

Over the past couple of decades, transportation systems have begun to receive widespread attention from the scientific community and emerged toward Intelligent Transportation Systems (ITS). Effective vehicular connectivity techniques can significantly enhance efficiency of travel, reduce traffic incidents and improve safety, and alleviate the impact of congestion; devising the ITS experience. Furthermore, during the past decades, the volume and density of vehicles increased significantly, especially the road traffic; this lead to a dramatic increase in the number of accidents and congestion, with negative impacts on the economy, environment, and quality of people’s lives. In particular, according to the World Health Organization (WHO), road traffic injuries are estimated to be the leading cause of death for young people aged 15–29 and the ninth cause of death worldwide in 2015. The enabling communication technologies are intended to realize the frameworks that will spur an array of applications and use cases in the domain of road safety, traffic efficiency, and driver’s assistance. Although these applications will allow the dissemination and gathering of useful information among vehicles and between transportation infrastructure and vehicles in pursuance of assisting drivers to travel safely and comfortably, much effort is required to implement these practices for the success of these applications.

A Novel Approach for Data Communication and Safety Concern in VANET Using Cognitive Radio

VANET is branch of networking that is used for communication in intelligent transportation system. In this process of VANET various nodes are interconnected to each other and road side units. R2R, V2V and V2R communication has been done in VANET. Due to variouscommunications under VANET routing protocols have overhead for computation of shortest path and transmission of information with minimum delay. Delay in the network cause minimum safety. In this paper an approach has been proposed that can be used for transmission of safety message over the network with minimum delay. On the basis of proposed approach safety message can be transmitted in shortest interval of time so that safety can be achieved in the network.

Penta-band Linear Tapered Feed Spiral Antenna Design and Radio Link Characterization for Vehicular Communications

Increasing mobility, safety and passenger comfort are very strong motivations for implementation of Intelligent Transportation Systems (ITS) in practice. The role of wireless communications in ITS has become compelling, both for industry and research community. Wireless communications technologies provide a platform for the exchange of data among the vehicles. A penta-band printed spiral antenna with tapered feed is proposed for vehicular communication system, facilitating vehicle-to-vehicle (V2V) and infrastructure to vehicle (I2V) communication. The antenna covers the navigational frequencies viz., 1.2, 1.5 GHz and Wireless Communication frequencies viz., 2.45, 3.3 GHz and Dedicated Short Range Communication frequency, 5.8 GHz for vehicular communications. Further, radio link characterization of I2V and V2V propagation channel is carried out using Electromagnetic propagation tool, and compared with empirical path loss models of ITU, two-ray reflection and inter-vehicle models.

Stochastic Analysis of Network Coding Based Relay-Assisted I2V Communications in Intelligent Transportation Systems

We investigate the information transmission in a typical communication scenario in the intelligent transportation systems (ITS), that is, infrastructures providing ITS services that intend to broadcast independent messages to the vehicles within their coverage areas. Due to the dynamic nature of wireless signal propagation links and interuser interference, it is hard to guarantee satisfactory performance by direct infrastructure to vehicle (I2V) transmissions. To solve this problem, we propose allowing certain vehicles to serve as relays to assist in the information distribution process and applying a class of finite-field network codes to efficiently use the available spectrum resources. Considering that the infrastructure information sources and all vehicles are randomly distributed following Poisson point processes, we model a general urban ITS communication network and based on the stochastic geometry we derive the probability that a vehicle can successfully recover all the desired messages from its serving infrastructure. The analytical and numerical results clearly demonstrate that our proposed network coding based relay-assisted I2V transmission can significantly improve the communication performance of the conventional direct I2V transmission strategy.

Implementation of Standardized Cooperation Environment for Intelligent Transport Systems

Many of Intelligent Transport Systems (ITS) solutions are using components that dynamically change in time and space. Among these, there occur changes of location, movement parameters, components configuration, external environment influence, automation use, etc. Standard facilities in ITS communication model are useful base for implementation of the services in such variable environment. Such features have an influence on the implementation of the services and requirements for the lower communication layers.

Process for evaluating the data transfer performance of wireless traffic sensors for real‐time intelligent transportation systems applications

Different wireless communication technologies, such as wireless fidelity (Wi-Fi), 4G cellular technologies and worldwide interoperability for microwave access (WiMAX) have been used as alternatives or supplement to wired communication in intelligent transportation systems (ITS). Widespread deployment of wireless technologies in ITS require a comprehensive understanding of their performance, limitations and advantages in different field conditions. The authors evaluated performance of Wi-Fi wireless communication between adjacent roadside ITS devices (i.e., nodes) in different field conditions with varying characteristics of Wi-Fi technology. Field tests revealed that modulation rates, transmission power, line of sight, distance between nodes play critical roles in the performance of Wi-Fi communication in different roadway conditions. To achieve a desired level of performance requirements between adjacent nodes, minimum network performance thresholds must be realized in the field. Transportation agencies can identify the achievable performance, such as saturated throughput, delivery ratio and received signal strength at a particular location, by following the field test procedure developed in this research. The evaluation strategies and results presented in this study will contribute to the future planning and design of Wi-Fi communication for a roadway wireless sensor or device network considering corresponding communication performance requirements for specific ITS applications.

A Dynamic and Self-Adaptive Network Selection Method for Multimode Communications in Heterogeneous Vehicular Telematics

With the increasing demands for vehicle-to-vehicle and vehicle-to-infrastructure communications in intelligent transportation systems, new generation of vehicular telematics inevitably depends on the cooperation of heterogeneous wireless networks. In heterogeneous vehicular telematics, the network selection is an important step to the realization of multimode communications that use multiple access technologies and multiple radios in a collaborative manner. This paper presents an innovative network selection solution for the fundamental technological requirement of multimode communications in heterogeneous vehicular telematics. To guarantee the QoS satisfaction of multiple mobile users and the efficient utilization and fair allocation of heterogeneous network resources in a global sense, a dynamic and self-adaptive method for network selection is proposed. It is biologically inspired by the cellular gene network, which enables terminals to dynamically select an appropriate access network according to the variety of QoS requirements and to the dynamic conditions of various available networks. The experimental results prove the effectiveness of the bioinspired scheme and confirm that the proposed network selection method provides better global performance when compared with the utility function method with greedy optimization.

A compatibility strategy for enabling secure and efficient ITS communications in today’s Internet

Emerging communication services in the intelligent transportation systems (ITS) scenario have recently considered the provision of Internet services because this fact will aid in safety purposes and will offer a wide scope of applications to end users. Consequently, and considering the ITS scenario a specific mobile networking context (several connection capable nodes moving at the same time), mobile communications should provide the required security level as well as efficiency. In this regard, mobility management is the key aspect in this scenario so the mobility protocol underneath has to ensure those properties. In this article, thanks to the security and efficiency properties it provides from its design, we consider the NeMHIP protocol an appropriate alternative for managing mobility in the ITS context. Nevertheless, NeMHIP entails challenges when being introduced in the current legacy Internet architecture. In order to deal with these issues, this article proposes a compatibility strategy. This strategy involves a novel naming resolution procedure based on the definion of an evolved DNS resolution process. As a result, mobile networks can securely and efficiently move along the current Internet, using most common communication services transparently. We have implemented the compatibility solution in a testbed, validated its functionality and design correctness to assess its feasibility. Obtained results demonstrate the feasibility of the proposed strategy.

Pseudonyms in IPv6 ITS Communications: Use of Pseudonyms, Performance Degradation, and Optimal Pseudonym Change

IPv6 developed as a next generation Internet protocol will provide us with safer and more efficient driving environments as well as convenient and infotainment features in cooperative intelligent transportation systems (ITS). In this paper, we introduce the use of pseudonyms in IPv6 ITS communications for preserving location privacy. We conduct qualitative study on the performance degradation due to the use of pseudonyms and quantitative analysis on the optimal pseudonym change interval. Numerical results demonstrate that an appropriate pseudonym change interval should be changed depending on the packet arrival rate, mobility rate, and security level.

A Cluster Management System for VANETs

Vehicular ad-hoc networks (VANETs) are a key solution for communication in intelligent transportation systems (ITS). However, high mobility of vehicles on roads may cause varying delays and message losses which can limit the use of VANETs in some ITS scenarios. This paper proposes and evaluates a cluster management system for VANETs (CMS) that makes communication in VANETs more robust and efficient, enabling the collection of data of individual vehicles that travel on roads at any time. Simulated experiments show that the proposed system achieves improved communication in VANETs enabling their use in ITS applications such as the real-time road traffic management and control.

Evaluation of IEEE 802. 11p in Vehicular Communication via Simulation

IEEE 802. 11p, which is a fundamental protocol of dedicated short—range communication in intelligent transportation systems, is evaluated in this work. The relationship of IEEE 802. 11p with other protocols in the layered architecture for DSRC, as well as the standard framing process for wireless transmission, is studied. The common problems of the orthogonal frequency division multiplexing vehicular communication system and their solutions, such as channel estimation, carrier frequency offset, and symbol time offset, are analyzed by simulation. Analysis results indicate the acceptable reliability and performance of IEEE 802. 11p. Simulation results confirm the viability of the design of related applications.

지능형 교통시스템을 위한 u-TSMVPN의 설계와 성능분석

국내와 국제적으로 지능형 차량 및 텔레매틱스(ITS)의 연구와 개발을 통해서 차량에 IT 기술을 통합하기 위한 노력을 가속화하고 있다. 우리나라의 경우에 텔레매틱스(ITS) 서비스를 추진하고 있다. ITS에서의 실시간 데이터 통신은 중요한 것이다. ITS는 실시간으로 차량으로부터 데이터를 수집하여, ITS 센터에서 수집된 정보를 가공하여 제공한다. 이러한 통신과정에서, 효과적이고 보안적인 통신 방식을 제안하고자 한다. 특히, 본 논문에서 제안하고 있는 SIP기반의 MVPN은 시그널링 비용을 줄이고, 보안적인 측면에서 많은 이점이 있다. 또한, 차량간의 통신에서는 NEMO를 적용하여 이동성관리를 하였다. 즉, ITS에서의 차량간의 통신과 차량과 서버간의 통신을 위한 SIP기반의 모바일 VPN과 V2V NEMO에 대해서 제안한다. 성능분석을 수행하여, SIP 기반의 MVPN의 ITS는 핸드오프 시그널링 비용이 상당히 절감된다는 것을 보여준다.

Multiple hypothesis tracking for data association in vehicular networks

The introduction of Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I) communications in Intelligent Transportation Systems of the future brings new opportunities and new challenges into the automotive scene. Vehicular communications broaden the information spectrum that is available to each vehicle, allowing the enhancement of existing applications and the introduction of new ones. Undoubtedly, the impact of this new technology in transportation safety, efficiency and infotainment is expected to be very important.A significant part of research in vehicular networks (VANETs) is dedicated to networking issues like routing and safety. However, perception systems which until now were based on onboard sensors only, need to incorporate the wirelessly received information in order to extend the situation awareness of the vehicle and the driver. This paper presents an algorithm for associating targets tracked from an onboard radar sensor with the position and motion data received from the VANET. The core of the algorithm is a track oriented multiple hypothesis tracker that is modified for incorporating information included in VANET messages. The algorithm is tested in real scenarios using two experimental vehicles and then compared with two other algorithmic approaches. One is using a simpler single hypothesis algorithm for association of VANET messages and the second is using only the onboard sensors for environment perception. As a result, the advantages of the Multiple Hypothesis Algorithm regarding association performance and the added value of wireless information in the perception system are highlighted.

Challenges and Opportunities for Securing Intelligent Transportation System

There has been considerable work addressing security in vehicular network systems for intelligent transportation system (ITS) usages. We examine the proposed security framework and solutions in this space. Our analysis leads to several key observations. The current security work misses many practical ITS usage and security requirements, since it fails to consider practical economic models and critical ITS functional requirements as a control system. Consequently, the standardized ITS communication message authenticity solutions have little utility relative to addressing the real threats. Furthermore, we analyzed the missing requirements for public key infrastructure support for secure vehicular communication. Based on our analysis, we call for future research directions in analyzing practical problems and designing solutions to secure vehicular communication in order to achieve its full potential.

Study of the Effect of Velocity on End-To-End Delay For V2V Communication In ITs

This paper focuses on vehicle to vehicle (V2V) communications in VANET. With the development of vehicles and mobile Ad Hoc network technology, the Vehicle Ad hoc Network (VANET) has become an emerging field of study. VANET is a special case of MANET, and will play an important role in city road traffic control. It is a challenging problem for searching and maintaining an effective route for transporting data information. Vehicular Ad Hoc network (VANET), is a hot topic applying mobile Ad Hoc network (MANET) to ITS in recent years. In the era of wireless computing, VANET communications are gaining a lot of attention. In this paper we provide a simulation and study of the effect of velocity on end-to-end delay for v2v communication in intelligent transportation Systems

Adaptive Reduced-Rank Estimation of Nonstationary Time-Variant Channels Using Subspace Selection

In this paper, we focus on adaptive time-variant channel estimation for vehicle-to-vehicle (V2V) communications in intelligent transportation systems (ITS) using the IEEE 802.11p physical layer. The IEEE 802.11p pilot pattern is identical to that in the well-known IEEE 802.11a/g (WiFi) standard, which was initially designed for indoor environments with little or no mobility. However, in a V2V drive-by situation, the channel impulse response rapidly changes due to the high relative velocity between transmitter and receiver, as well as the changes in the scattering environment. Hence, for such V2V channels, advanced decision directed channel estimation methods are needed to reach a frame error rate (FER) smaller than 10-1 . Even more importantly, the channels are nonstationary, which implies that the Doppler power spectral density (DSD) and the power delay profile (PDP) change on a timescale comparable with the frame length, which complicates the estimator design. In this paper, we develop an adaptation method for the channel estimation filter that is suitable for the following: 1) the short frame length in IEEE 802.11p; 2) the given pilot structure; and 3) the requirement of only a single received short frame for filter adaptation. We define a set of hypotheses on the support of the DSD and a second set of hypotheses on the support of the PDP. Each hypothesis is represented by a specific subspace spanned by orthogonal basis vectors. For basis vector calculation, we develop a numerically stable algorithm utilizing generalized discrete prolate spheroidal sequences. The adaptation algorithm chooses a hypothesis from both sets such that a probabilistic bound on the channel estimation error is minimized. We implement the hypothesis test by means of a novel subspace selection algorithm that allows utilizing correlated observations of a time- and frequency-selective (2-D) fading process. We validate the adaptive channel estimation scheme in an IEEE 802.11p compliant link level simulation for a relative velocity range from 0 to 111 m/s ≈ 400 km/h ≈ 249 mi/h. Adaptive filtering enables an up to fourfold reduction in the number of required iterations to reach an FER below 10-1 for an Eb/N0 = 12 dB.

IPv6 Security Issues in Cooperative Intelligent Transportation Systems

Cooperative Intelligent Transportation Systems (ITS) will turn up to us with safer and more efficient driving environments as well as convenient and infotainment features for future ITS stations. ETSI and ISO are completing the standardization of the building blocks of a reference communication architecture for cooperative ITS. Future ITS stations complying with this set of standards deployed in vehicles, at the roadside infrastructures and within the Internet are expected to communicate with each other through a combination of ITS dedicated communication protocols and legacy Internet protocols. However, in spite of the wide adoption of IPv6 for cooperative ITS communications, relatively little attention has been paid to the security issues related to IPv6 signaling and IPv6 transport communications. In this paper, we present our position on the emerging and urgent IPv6-related security issues that occur in communications between ITS stations complying with the ITS station reference architecture under standardization within ETSI TC ITS and ISO TC204.

An Asymmetric and Asynchronous Energy Conservation Protocol for Vehicular Networks

Intelligent Transportation Systems (ITS) improve passenger/pedestrian safety and transportation productivity through the use of vehicle-to-vehicle and vehicle-to-roadside wireless communication technologies. Communication protocols in these environments must meet strict delay requirements due to the high moving speed of the vehicles. In this paper, we propose an energy-conservative MAC layer protocol, named DSRC-AA, based on IEEE 802.11 that provides power saving to the ITS communication modules (e.g., On Board Units, portable devices, and Road Side Units) while ensuring the bounded delay. DSRC-AA, a generalization of the Asynchronous Quorum-based Power-Saving (AQPS) protocols, capitalizes on the clustering nature of moving vehicles and assigns different wake-up/sleep schedules to the clusterhead and the members of a cluster. DSRC-AA is able to dynamically adapt the schedules to meet the communication delay requirements at various vehicle moving speed. Simulation results show that DSRC-AA is able to yield more than 44 percent reduction in average energy consumption as compared with the existing AQPS protocols, if to be used in vehicular networks.