Amit Dua | Neeraj Kumar | Seema Bawa
Vehicular Ad Hoc Networks (VANETs) have emerged as a new powerful technology with an aim of providing safety for the persons sitting in the vehicles. Vehicles may be connected to the Internet with/without the existing infrastructure using various IEEE standards such as IEEE 802.11p. But as nodes in VANETs have very high mobility, so there are lots of challenges to route the packets to their final destination which need to be addressed by existing/proposing new solutions for the same. Keeping in view of the above, this paper provides a detailed description of various existing routing techniques in literature with an aim of selecting a particular strategy depending upon its applicability in a particular application. A detailed categorization of various routing techniques is provided in the paper with critical discussion on each categorization with respect to its advantages, disadvantages, various constraints and applications. Finally, numbers of parameters are selected for comparison and analysis of all the existing routing schemes in the literature. © 2014 Elsevier Inc.
Mohamed Nidhal Mejri | Jalel Ben-Othman | Mohamed Hamdi
In the near future, it is expected that vehicles which increasingly become an intelligent systems will be equipped with radio communications interfaces. Thus, vehicular networks can be formed and they are commonly known as VANETs (Vehicular Ad hoc NETworks), a use case of mobile ad hoc networks where cars are the mobile nodes. As VANETs exhibit several unique features such as the high mobility of nodes, short connection times, etc. conventional security mechanisms are not always effective. Consequently, a wide variety of research contributions have been recently presented to cope with the intrinsic characteristics of vehicular communication. This paper provides a summary of the recent state of the art of VANETs, it presents the communication architecture of VANETs and outlines the privacy and security challenges that need to be overcome to make such networks safety usable in practice. It identifies all existing security problems in VANETs and classifies them from a cryptographic point of view. It regroups, studies and compares also the various cryptographic schemes that have been separately suggested for VANETs, evaluates the efficiency of proposed solutions and explores some future trends that will shape the research in cryptographic protocols for intelligent transportation systems. © 2014 Elsevier Inc.
Rasmeet S. Bali | Neeraj Kumar | Joel J.P.C. Rodrigues
Over the last few years, Vehicular Ad Hoc Networks (VANETs) have emerged as a new class of efficient information dissemination technology among communities of users mainly because of their wide range of applications such as Intelligent Transport Systems (ITS), Safety applications, and entertainment during the mobility of the vehicles. Vehicles in VANETs act as an intelligent machine, which provides various resources to the end users with/without the aid of the existing infrastructure. But due to the high mobility and sparse distribution of the vehicles on the road, it is a challenging task to route the messages to their final destination in VANETs. To address this issue, clustering has been widely used in various existing proposals in literature. Clustering is a mechanism of grouping of vehicles based upon some predefined metrics such as density, velocity, and geographical locations of the vehicles. Motivated from these factors, in this paper, we have analyzed various challenges and existing solutions used for clustering in VANETs. Our contributions in this paper are summarized as follows: Firstly, a complete taxonomy on clustering in VANETs has been provided based upon various parameters. Based upon this categorization, a detailed discussion is provided for each category of clustering which includes challenges, existing solutions and future directions. Finally, a comprehensive analysis of all the existing proposals in literature is provided with respect to number of parameters such as topology selected, additional infrastructure requirements, road scenario, node mobility, data handled, and relative direction, density of the nodes, relative speed, communication mode, and communication overhead. The analysis provided for various existing proposals allows different users working in this domain to select one of the proposals with respect to its merits over the others. © 2014 Elsevier Inc.
Moumena Chaqfeh | Abderrahmane Lakas | Imad Jawhar
© 2014 Elsevier Inc. The rapid evolution of wireless communication capabilities and vehicular technology would allow traffic data to be disseminated by traveling vehicles in the near future. Vehicular Ad hoc Networks (VANETs) are self-organizing networks that can significantly improve traffic safety and travel comfort, without requiring fixed infrastructure or centralized administration. However, data dissemination in VANET environment is a challenging task, mainly due to rapid changes in network topology and frequent fragmentation. In this paper, we survey existing data dissemination techniques and their performance modeling approaches in VANETs, along with optimization strategies under two basic models: the push model, and the pull model. In addition, we present major research challenges.
Nan Cheng | Ning Lu | Ning Zhang | Xuemin Sherman Shen | Jon W. Mark
WiFi offloading is envisioned as a promising solution to the mobile data explosion problem in cellular networks. WiFi offloading for moving vehicles, however, poses unique characteristics and challenges, due to high mobility, fluctuating mobile channels, etc. In this paper, we focus on the problem of WiFi offloading in vehicular communication environments. Specifically, we discuss the challenges and identify the research issues related to drive-thru Internet access and effectiveness of vehicular WiFi offloading. Moreover, we review the state-of-the-art offloading solutions, in which advanced vehicular communications can be employed. We also shed some lights on the path for future research on this topic. © 2013 Elsevier Inc.
Fernando A. Teixeira | Vinicius F. e Silva | Jesse L. Leoni | Daniel F. Macedo | José M S Nogueira
The IEEE 802.11 working group proposed a standard for the physical and medium access control layers of vehicular networks called 802.11p. In this paper we report experimental results obtained from communication between vehicles using 802.11p in a real scenario. The main motivation is the lack of studies in the literature with performance data obtained from off-the-shelf 801.11p devices. Our study characterizes the typical conditions of an 802.11p point-to-point communication. Such a study serves as a reference for more refined simulation models or to motivate enhancements in the PHY/MAC layers. Field tests were carried out varying the vehicle's speed between 20 and 60 km/h and the packet length between 150 and 1460 bytes, in order to characterize the range, throughput, latency, jitter and packet delivery rates of 802.11p links. It was observed that communication with vehicles in motion is unstable sometimes. However, it was possible to transfer data at distances over 300 m, with data rates sometimes exceeding 8 Mbit/s. © 2014 Elsevier Inc.
Nicola Cordeschi | Danilo Amendola | Mohammad Shojafar | Enzo Baccarelli
© 2014 Elsevier Inc. In this contribution, we design and test the performance of a distributed and adaptive resource management controller, which allows the optimal exploitation of Cognitive Radio and soft-input/soft-output data fusion in Vehicular Access Networks. The ultimate goal is to allow energy and computing-limited car smartphones to utilize the available Vehicular-to-Infrastructure WiFi connections for performing traffic offloading towards local or remote Clouds by opportunistically acceding to a spectral-limited wireless backbone built up by multiple Roadside Units. For this purpose, we recast the afforded resource management problem into a suitable constrained stochastic Network Utility Maximization problem. Afterwards, we derive the optimal cognitive resource management controller, which dynamically allocates the access time-windows at the serving Roadside Units (i.e., the access points) together with the access rates and traffic flows at the served Vehicular Clients (i.e., the secondary users of the wireless backbone). Interestingly, the developed controller provides hard reliability guarantees to the Cloud Service Provider (i.e., the primary user of the wireless backbone) on a per-slot basis. Furthermore, it is also capable to self-acquire context information about the currently available bandwidth-energy resources, so as to quickly adapt to the mobility-induced abrupt changes of the state of the vehicular network, even in the presence of fadings, imperfect context information and intermittent Vehicular-to-Infrastructure connectivity. Finally, we develop a related access protocol, which supports a fully distributed and scalable implementation of the optimal controller.
Mani Amoozadeh | Hui Deng | Chen Nee Chuah | H. Michael Zhang | Dipak Ghosal
© 2015 Elsevier Inc. Previous studies have shown the ability of vehicle platooning to improve highway safety and throughput. With Vehicular Ad-hoc Network (VANET) and Cooperative Adaptive Cruise Control (CACC) system, vehicle platooning with small headway becomes feasible. In this paper, we developed a platoon management protocol for CACC vehicles based on wireless communication through VANET. This protocol includes three basic platooning maneuvers and a set of micro-commands to accomplish these maneuvers. Various platooning operations such as vehicle entry and vehicle (including platoon leader) leaving can be captured by these basic platoon maneuvers. The protocol operation is described in detail using various Finite State Machines (FSM), and can be applied in collaborative driving and intelligent highway systems. This protocol is implemented in an integrated simulation platform, VENTOS, which is developed based on SUMO and OMNET++. The validity and effectiveness of our approach is shown by means of simulations, and different platooning setting are calibrated.
João A.F.F. Dias | Joel J.P.C. Rodrigues | Liang Zhou
Vehicular communications refer to a wide range of networks adopted in environments characterized by sparse connectivity, frequent network partitioning, intermittent connectivity, long propagation delays, asymmetric data rates, and high error rates. These environments may also be characterized by a potential non-existence of an end-to-end path. Cooperation among network nodes is crucial to address these challenging connectivity issues. In order to contribute for a better network performance, network nodes should to share their storage, bandwidth, and energy resources with each other. By sharing their resources each node contributes to store, carry, and forward network data in order to mutually enhance the overall network performance. However, not all network nodes are able to cooperate and sometimes they may have an uncooperative behavior in order to save their own resources. Such behavior severely affects the network functionality and performance. Then, this survey overviews the most recent advances related to cooperation on vehicular communications. The goal of this work is not only to present how cooperation between network nodes has advanced, but also to show the benefits and drawbacks of cooperation, and to identify open issues providing guidelines for further contributions in this type of networks. © 2013 Elsevier Inc.
Mario Gerla | Chuchu Wu | Giovanni Pau | Xiaoqing Zhu
Advances in vehicular communications technology are making content distribution to vehicles more effective and increasingly more popular. This paper presents state of the art technologies and protocols for content distribution in VANETs. Major challenges are Internet access spectrum scarcity, mobility, connectivity intermittence and scalability. Aspects covered in this paper include: coexistence of WiFi and LTE; application of network coding; protection from pollution attacks; incentive design for cooperation enforcement; QoS support for video streaming applications. Simulation and testbed results are presented to support the findings. Critical issues that will determine future directions in this area are identified and discussed. © 2013 Elsevier Inc.
Claudia Campolo | Antonella Molinaro | Riccardo Scopigno
© 2015 Elsevier Inc. After more than a decade of research and investments, the first release of standards for cooperative Intelligent Transportation Systems (C-ITS) is going to be finalized. Preliminary field-trials have already demonstrated the high potentials of short-range wireless communication in vehicular environments for many basic day-one C-ITS applications (e.g., hazardous location and road works warnings). In the meanwhile, stakeholders are working on Release 2 of the standards to augment the portfolio of offered services with increased cooperative awareness and driving automation. The related higher C-ITS market penetration and the strict latency and robustness requirements of after day-one applications (e.g., platooning and autonomous driving) are going to question the capability of the current standard technology, mainly base d on IEEE 802.11, to cope with scalability and congestion issues at the radio access level.In this paper, we analyze the topic of vehicular networks in the context of C-ITS from an evolutionary point of view, scanning early concepts and enabling technologies, current status and future opportunities, with a look on a future fully networked vehicular environment.
Hamid Reza Arkian | Reza Ebrahimi Atani | Atefe Pourkhalili | Saman Kamali
© 2014 Elsevier Inc. Vehicular Ad-hoc Network (VANET) is an emerging field of wireless networks providing different applications such as traffic information for participant vehicles and related authorities. However, deploying of such applications is mainly depending on the market penetration rate of this technology. In this paper, we propose a new 3-steps approach for estimation of traffic volume in a road segment based on actual volume of wireless-equipped vehicles. For this propose, we first collect the traffic information for different groups of vehicles using a new clustering algorithm. Then, a chaining technique between the clusters transmits this information to a roadside cloud. Finally, we employ a generalization method to extension of the total traffic volume from the collected data. Performance of the proposed approach is evaluated using extensive simulation for different traffic densities, and the stability of the clustering technique and also estimation accuracy of the proposed approach is shown in comparison with state-of-the-art existing schemes.
Ryan Florin | Stephan Olariu
© 2015 Elsevier Inc. Traffic congestion is an ever increasing problem on our roadways and city streets. The main contribution of this survey is a taxonomy of adaptive traffic signal control strategies achieved through various levels of vehicular communications.Strategies to optimize traffic signals fall into three categories based on the level of vehicle involvement. The first category involves those strategies that utilize legacy devices with no vehicular involvement. The second category comprises those strategies that utilize vehicles on the road to wirelessly transmit data about themselves (e.g. location, velocity). The third category involves strategies that utilize the vehicles' on-board computation power to help optimize traffic signals. The bulk of this survey deals with the second category as it appears to be the most prevalent in the research literature. We are however, quick to point out that the third category seems to be gaining momentum, as the prevalence of smartphones has suggested supplementing legacy traffic monitoring with traffic-related reports submitted by the driving public.
Nishu Gupta | Arun Prakash | Rajeev Tripathi
© 2015 Elsevier Inc. Vehicular Ad-Hoc Network (VANET) is seen as an emerging solution to improve road safety, highway assistance and traveler comfort accounting to vivid applications including safety, non-safety and infotainment applications. Over the past few years, research paradigm has shifted towards areas such as multi-hop broadcasting, information security, clustering, etc. covering intra-vehicular and vehicle-to-infrastructure communication modes. Whereas these scenarios provide diversified information dissemination techniques through various applications of Intelligent Transportation Systems (ITS), data dissemination in VANET environment is still a challenging task, mainly due to rapid changes in network topology and frequent disruptions in connectivity. A distinguished area that still lacks significant research contributions is towards designing reliable and efficient Medium Access Control (MAC) protocols for vehicular communication in order to enhance travel safety. The main motivation behind such a survey is to integrate a wide range of research contributions that have been recently proposed to envisage the inherent characteristics of vehicular communication. Such a study serves as a reference for an in-depth research towards enhancements in the PHY/MAC layers. In this paper, we present state-of-the-art survey of the MAC protocols available for vehicular safety. We classify these protocols based on different applications and the techniques they adopt. We also review the performance metrics used for evaluating these protocols. In later sections, we qualitatively analyze the protocols based on different parameters along with related issues and the challenges they generate. We highlight the mechanisms involved, conceptual features, optimization techniques, strength and drawbacks of the available protocols as well as their applicability in future deployment. Finally, we discuss the open issues and future research directions.
Mohammad A. Hoque | Xiaoyan Hong | Brandon Dixon
Vehicle to Vehicle (V2V) communication provides a flexible and real-time information dissemination mechanism through various applications of Intelligent Transportation Systems (ITS). Achieving seamless connectivity through multi-hop vehicular communication with sparse network is a challenging issue. In this paper, we have studied this multi-hop vehicular connectivity in an urban scenario using GPS traces obtained from San Francisco Yellow cabs. Our current work describes a new algorithm for the analysis of topological properties like connectivity and partitions for any kind of vehicular or mobile computing environment. The novel approach uses bitwise manipulation of sparse matrix with an efficient storage technique for determining multi-hop connectivity. The computation mechanism can be further scaled to parallel processing environment. The main contribution of this research is threefold. First, developing an efficient algorithm to quantify multi-hop connectivity with the aid of bitwise manipulation of sparse matrix. Second, investigating the time varying nature of multi-hop vehicular connectivity and dynamic network partitioning of the topology. Third, deriving a mathematical model for calculating message propagation rate in an urban environment. © 2014 Elsevier Inc.
Ribal F. Atallah | Maurice J. Khabbaz | Chadi M. Assi
© 2015 Elsevier Inc. Advanced wireless technologies are, nowadays, being exploited as means for intelligent transportation management and on-the-road driving assistance. However, the recent synergic efforts in both industry and academia are symptomatic of a paradigm shift in Intelligent Transportation Systems. Today's vehicles, being equipped with computerized modules and wireless devices, characterize themselves by a revolutionary smart personality. In particular they can carry and distribute information, they inter-communicate and are capable of communicating with other stationary units deployed along roadways. Most importantly, they can sense. Ultimately, the transportation infrastructure embraces versatile wireless communication systems with the objective of provisioning Wireless Access in Vehicular Environments (WAVE). In order to catalyze the realization of this objective, the U.S. Federal Communications Commission (FCC) has allocated 75 MHz of spectrum for Dedicated Short Range Communications (DSRC). The Institute of Electrical and Electronics Engineers (IEEE) has specifically tailored the 802.11. p standard to regulate access to this spectrum. The IEEE 1609.4 protocol allows for multi-channel access and is currently being standardized. Alternatively, researchers have engaged in the design of scheduling policies for the purpose of increasing the spectrum access efficiency and optimizing the performance of vehicular networks in terms of several classical metrics. The recently emerging spectrum scarcity problem has led numerous investigations on the potential exploitation of cognitive radios as well as the feasibility of Vehicular Dynamic Spectrum Access (VDSA) schemes with the objective of: a) enhancing spectrum utilization and b) improving the network's throughput and response time. This paper sheds the light over the latest advancements in each of the above-mentioned research sectors and highlights pending open issues in each of them.
Hamed Vahdat-Nejad | Azam Ramazani | Tahereh Mohammadi | Wathiq Mansoor
© 2016 Elsevier Inc. Transportation is considered as one of the main human needs in any country for macro-level planning. Due to increased production of vehicles, problems and issues associated with transportation systems have been taken on wider dimensions. Thanks to rapid technological developments, Vehicular Ad hoc Networks (VANETs) have been used to provide effective opportunities for enhancing the safety of roads and for improving transportation networks. Various context-aware applications have been designed on vehicular ad hoc networks, offering a wide range of services to drivers, including traffic management, collision avoidance, and convenient supports, just to name a few. This paper reviews and classifies existing context-aware applications as used in vehicular networks. A classification framework with three dimensions including the environment, system-and-application, and context-awareness is proposed. This framework is then used to review the existing context-aware transportation systems for each dimension, which in turn consists of some parameters. Based on this framework, existing context-aware research projects are reviewed and classified. Finally, a clear vision of research directions in this area is described.
Min Chen | Dung Ong Mau | Yin Zhang | Tarik Taleb | Victor C.M. Leung
© 2014 Elsevier Inc. Named Data Networking (NDN) is proposed for effective content distribution when a large number of end-users demand for popular content at the same time. Thus, NDN can be implemented in Vehicular ad-hoc NETwork (VANET) to meet the particular requirements. Therefore, all of vehicles refer to the real time traffic status by a faster and more efficient network. In this paper, we propose VEhicular Named Data NETwork (VENDNET) according to three different vehicle communication mechanisms, which are vehicle-to-infrastructure (V2I), a hybrid of vehicle to road side unit (V2R) and vehicle to vehicle (V2V). Furthermore, this paper illustrates the experimental results conducted by OPNET Modeler, and shows that the solution with NDN enhances the Quality of Service (QoS) of VANET significantly.
Muhammad Awais Javed | Duy Trong Ngo | Jamil Yusuf Khan
© 2014 Elsevier Inc. The periodic generation and transmission of basic safety messages (BSM) place a heavy burden on the load of a vehicular ad hoc network (VANET), where there also remain multiple packet collisions undetected due to the hidden terminals. In this paper, we propose a distributed scheme that controls the spatial reuse distance to improve the efficiency of BSM transmissions in space-division multiple access (SDMA) based VANETs. With the proposed SDMA structure, only vehicles located sufficiently far apart are allowed to reuse the same time slot to send their BSMs. The signal interference is thus reduced while the hidden-node problem is essentially alleviated. Multiple transmissions per SDMA road segment or 'cell' are also enabled using the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA), giving rise to a much better use of both space and bandwidth. To guarantee that the actual number of BSM transmissions does not exceed the maximum allowable in each SDMA cell, we further devise an adaptive scheme that adjusts the spatial reuse distance in accordance with the vehicle density. Because the global information of vehicle density is not available at individual vehicles, we propose a distributed algorithm that estimates the vehicle density and makes consensus to enhance the accuracy of spatial reuse distance estimation. As the transmission range is controlled accordingly, the mutual interference among the SDMA cells is further reduced. Importantly, the developed control algorithm can be distributively implemented by each vehicle with limited information exchange. To optimize the performance of the proposed solution, we also determine the optimal bandwidth utilization that maximizes the newly-defined criterion termed as 'safe range,' an important figure-of-merit in vehicular safety applications. Simulation results confirm the clear advantages of our proposal over the available approaches in terms of safety range, packet reception rate, end-to-end delay and BSM inter-arrival time in realistic network scenarios.
Next-generation communication networks have become widely popular as ad-hoc networks, broadly categorized as the mobile nodes based on mobile ad-hoc networks (MANET) and the vehicular nodes based vehicular ad-hoc networks (VANET). VANET is aimed at maintaining safety to vehicle drivers by begin autonomous communication with the nearby vehicles. Each vehicle in the ad-hoc network performs as an intelligent mobile node characterized by high mobility and formation of dynamic networks. The ad-hoc networks are decentralized dynamic networks that need efficient and secure communication requirements due to the vehicles being persistently in motion. These networks are more susceptible to various attacks like Warm Hole attacks, denial of service attacks and Black Hole Attacks. The paper is a novel attempt to examine and investigate the security features of the routing protocols in VANET, applicability of AODV (Ad hoc On Demand) protocol to detect and tackle a particular category of network attacks, known as the Black Hole Attacks. A new algorithm is proposed to enhance the security mechanism of AODV protocol and to introduce a mechanism to detect Black Hole Attacks and to prevent the network from such attacks in which source node stores all route replies in a look up table. This table stores the sequences of all route reply, arranged in ascending order using PUSH and POP operations. The priority is calculated based on sequence number and discard the RREP having presumably very high destination sequence number. The result show that proposed algorithm for detection and prevention of Black Hole Attack increases security in Intelligent Transportation System (ITS) and reduces the effect of malicious node in the VANET. NCTUNs simulator is used in this research work.