Emerging techniques for wireless vehicular communications

Abstract

Welcome to this special issue of Wiley Journal of Wireless Communications and Mobile Computing (WCMC). To date, wireless vehicular communications have attached much attention for improving road safety, intelligent management and data exchange services, and providing Internet access on the move to ensure wireless pervasive and ubiquitous connectivity. The field of wireless vehicular communications can be typically identified as vehicle-to-person communications, vehicle-to-infrastructure communications, vehicle-to-vehicle communications, and vehicular communication networks. The combination of unique features of wireless vehicular communications and networking issues opens new opportunities for many interesting research areas, for example, real time safety applications, and intelligent diver information services. The goal of this special issue is to present good-performance, highly scalable, robust, and secure vehicular technologies for universal realization of wireless vehicular communications. To guarantee the quality, in this special issue, we have selectively collected 15 papers out of over 60 submissions, and clustered them in four groups: three are survey papers, four papers deal with channel modeling and physical layer issues, six papers investigating MAC and network layer issues, and two papers focusing on applications. Detailed overview of the selected works is given below. The first group includes three papers, which survey recent advances in wireless vehicular communications. The first paper, by Chen et al., provides recent results for data dissemination in vehicular ad hoc networks (VANETs). This paper also discusses security challenges in this field and the need of supporting technologies to enable efficient data dissemination for automotive applications. The paper by Leng et al. gives a global review of media access control techniques for VANETs. This paper summarizes recent work in this domain including MAC standardization activities, wireless channel resource management, QoS capability enhancement in MAC layer, and reliable MAC broadcasting strategies. The third paper, by Martinez et al., makes a survey of several publicly available mobility generators, network simulators, and VANET simulators. This paper contrasts their software characteristics, graphical user interface, popularity, ease of use, input requirements, output visualization capability, and accuracy of simulation. The second group includes four papers, which provide channel modeling and physical layer results for VANETs. The first paper, by Cheng et al., proposes new deterministic and stochastic sum-of-sinusoids based simulation models by using a ‘double-ring’ concept to describe mobile-to-mobile non-isotropic scattering environments. The proposed simulation models extensively consider the distributions of the angle of arrival and the angle of departure, and thus provide a good approximation to the desired statistical properties of the reference model. The second paper by Ren et al., gathers the current knowledge of the absolute phase and associated various clicks, which is scattered across many decades and across different aspects of communications, and it also adds new results for the mobile channel. The phase behavior of the mobile channel offers a fertile area for further research. The paper, by Xu et al., proposes a novel method for node positioning in vehicular communication systems, which allows a vehicular node to play the role of an observation station, and estimates the vehicular node's absolute coordinates based on the measurement of the Doppler frequency shift, the velocity of the vehicular node, and the known absolute coordinates of roadside nodes. The fourth paper, by Li et al., investigates the antenna array technique for its ability in reducing the multipath delay spread of the ionosphere channel and, thus, increasing possibly the bandwidth of the HF system. The third group of papers mainly investigates MAC and network layer issues, co