Vehicular Ad Hoc Networks Protocols Research Articles

Group-based protocol and mobility model for VANETs to offer internet access

Some public transport vehicles embed devices that allow passengers to connect to Internet while traveling. These vehicles are true mobile Internet access zones inside public paths. These zones could be used by other vehicles moving close to them in order to have Internet access. At the same time, other vehicles in the influence area could be used as relay nodes which would increase this access area. In this paper, we present a group-based protocol and mobility model for vehicular ad hoc networks (VANETs) where each public transport vehicle forms a group of vehicles. They can access and allow access to Internet though the public transport vehicle. Each vehicle is moving inside the group and can leave and join any group at will, while all groups are moving. First, we will show the algorithm and protocol to achieve our purpose. Then, we will study the probability of having Internet access in order to demonstrate that it is a feasible proposal. Finally, we simulate a study case based on real values in order to obtain the performance of our proposal in terms of several network parameters such as the number of hops per route, the network traffic, the page response time, network delay, network load and so on.

Performance Evaluation of Proactive and Reactive Protocols in VANET

  Abstract—VANET (Vehicular adhoc network) research field is growing very fast. It has to serves a wide range of applications under different scenario (City, Highway). It has various challenges to adopt the protocols that can serve in different topology and scenario. This paper presents a comparative study of the adhoc routing protocols. The main objective of Vehicular adhoc networks is to build a robust network among mobile vehicles so that vehicles can talk to each other for the safety of human beings. VANET hits the protocol's strength due to its highly dynamic features. Thus in testing a protocol suitable for VANET implementation, we have selected different routing protocols. In this paper, an attempt has been made to compare four well-known protocols AODV, DSR, OLSR and DSDV by using three performance metrics packet delivery ratio, average end to end delay and routing overhead. The comparison has been done by using simulation tool NS2 which is the main simulator, Network animator (NAM) and excel graph which is used for preparing the graphs from the trace files.

An Optimal ODAM-Based Broadcast Algorithm for Vehicular Ad-Hoc Networks

Broadcast routing has become an important research field for vehicular ad-hoc networks (VANETs) recently. However, the packet delivery rate is generally low in existing VANET broadcast routing protocols. Therefore, the design of an appropriate broadcast protocol based on the features of VANET has become a crucial part of the development of VANET. This paper analyzes the disadvantage of existing broadcast routing protocols in VANETs, and proposes an improved algorithm (namely ODAM-C) based on the ODAM (Optimized Dissemination of Alarm Messages) protocol. The ODAM-C algorithm improves the packet delivery rate by two mechanisms based on the forwarding features of ODAM. The first distance-based mechanism reduces the possibility of packet loss by considering the angles between source nodes, forwarding nodes and receiving nodes. The second mechanism increases the redundancy of forwarding nodes to guarantee the packet success delivery ratio. We show by analysis and simulations that the proposed algorithm can improve packet delivery rate for vehicular networks compared against two widely-used existing protocols.

Affinity Based Clustering Routing Protocol for Vehicular Ad hoc Networks

Vehicular ad hoc network is a high mobility wireless ad hoc network that becomes a promising technology in which moving vehicles are able to exchange information between them without the need of infrastructure. Developing multi-hop communication in vehicular ad hoc networks (VANET) is a challenging task due to vehicles movement at various velocities and rapidly changing highly dynamic network topology. Links between network nodes could be broken at anytime and communications between vehicles could be corrupted. In order to provide stable communication linkages between vehicular nodes, a good routing protocol is needed. In this paper we have presented a brief review of state of the art scenario of routing protocols and present a new affinity based clustering routing protocol for VANET which partioned the total network in some variable sized clusters, based on the infrastructure type & traffic and node speed and affinity propagation technique. The main objective of this new proposed routing protocol is to reduce the routing overhead and reduce the time delay for appropriate route finding.

车载自组织网络MAC协议研究综述

近年来，随着车载通信系统的不断发展和自组织网络技术的日益成熟，将二者有机结合成一体的车载自组织网络(VANET, Vehicular Ad Hoc Networks)已引起学术界和工业界的极大关注。媒介接入控制(MAC, Medium Access Control)协议是保证移动终端能够公平有效地共享无线信道的必要手段，是车载自组织网络的关键技术之一。由于VANET自身的特点及不断增长的业务不同，现有自组织网络的MAC协议并不能直接用于车载自组织网络中。本文在简要介绍车载自组织网络特点和MAC协议基本原理的基础上，对车载自组织网络MAC协议的最新研究进展进行了综述，探讨了几种具有代表性的车载自组织网络MAC协议方案，分析了目前研究中存在的主要问题和挑战，并指出了该领域未来发展趋势。 In recent years, with the rapid development of vehicular communication systems and advanced ad hoc network technologies, Vehicular Ad Hoc Networks (VANET) which combines both of them has greatly attracted those people’s attention in academic and industry fields. As one of the key technologies in vehicular ad hoc networks, MAC (Medium Access Control) protocol is indispensable to ensure the mobile nodes share the wireless medium fairly and efficiently. Since the specific characteristics and the increased variety of services in VANET, MAC protocols which are designed for Mobile Ad Hoc Networks are impossible to apply in VANET directly. In this paper, a survey of current MAC protocols for VANET is given. Then, we describe several latest MAC protocol schemes and analysis the main problems and challenges. Finally, some future research areas for MAC in VANET are pointed out.

Towards characterising and classifying communication-based automotive applications from a wireless networking perspective

Together, the Dedicated Short Range Communication (DSRC) and Vehicular Ad Hoc Network (VANET) technologies provide a unique opportunity to develop and introduce various types of communication- based automotive technologies to the marketplace. To date, many applications have been identified by the automotive community. Given the large number and diverse nature of these applications, it is advantageous to develop a systematic classification methodology to facilitate future DSRC and VANET research. Toward this objective, in this paper, we present a study that goes through two major steps: characterisation and classification. First, we focus on a set of representative applications and characterise them with respect to plausible application- and networking-related attributes. The characterisation process not only strengthens our understanding of the applications but also sets the stage for the classification step since it reveals numerous application commonalities. Thus, we have categorised the given applications into seven generic classes, with the consideration of balancing the trade-off between exploiting as many application similarities as possible while preserving their salient differences. This is of paramount importance to facilitate performance analysis of newly designed protocols. Finally, we have identified key performance metrics for each class of applications, which, we hope, could bridge the gap between the automotive and wireless networking communities. Accordingly, the proposed classes are envisioned to play a dual-role: facilitate application simulation and performance evaluation and guide DSRC and VANET protocol research and development.

Routing Architecture for Vehicular Ad-Hoc Networks

The actual proposed routing protocols for VANETs (Vehicular Ad-hoc Networks) present different features for communication among hosts/vehicles considering the strong topology change, but most of these features are needed for routing in these specific networks. These routing protocols support vehicle traffic on a large scale, intense mobility of vehicles, connections without link breakage, etc. But as they are different protocols the routers (nodes) have to switch to a routing protocol in a certain moment, which is a problem. This paper presents a routing architecture for VANETs to face it. The most important technical features for routing in VANETs were grouped in the Routing Architecture. To validate the proposed architecture several existing protocols were unified in the architecture producing a new routing protocol for VANETs. The produced protocol is the Generic Vehicular Dynamic Source Routing (GVDSR). Simulations of the GVDSR protocol have been made on the Malaga city showing the contributions and advantages for routing performance. The proposed architecture and protocol were simulated in the Network Simulator 2 featuring better performance than the compared protocols.

Considering driver behaviour in vehicular delay tolerant networks

A key component for vehicular ad-hoc networks (VANET) simulations is a realistic vehicular mobility model, as this ensures that the conclusions drawn from simulation experiments will carry through to the real deployments. Node mobility in a vehicular network is strongly affected by the driving behaviour such as route choices. While route choice models have been extensively studied in the transportation community, as far as we know, the effects of driver behaviour on vehicular network simulations have not been discussed much in the networking literature. In this work, we set out to understand the effects of destination selection vehicular network simulation. We also discuss how different destination selection models affect event broadcasting in ITS application. We conclude that selecting a sufficient level of detail in the simulations, such as modelling of destination selection, is critical for evaluating VANET protocol design.

A lightweight secure mobile Payment protocol for vehicular ad-hoc networks (VANETs)

In the last few years, many value-added applications (such as Payment services) in Vehicular Ad hoc NETworks (VANETs) have emerged. Although these applications offer great business opportunities they also introduce new concerns regarding security and privacy. Moreover, the wide range of scenarios (with or without connectivity restrictions) arising from vehicle-to-vehicle and vehicle-to-roadside communications have opened up new security challenges which must be considered by Payment system designers to achieve the same security capabilities independent of the scenario where Payment occurs. We designed and implemented a lightweight (using symmetric-key operations which requires low computational power) secure Payment protocol for those scenarios in VANETs and other mobile environments where the Merchant cannot communicate directly with the Acquirer (the Merchant's financial institution) to process the Payment Request. We also present practical performance results that can be achieved with the proposed Payment protocol.

Linear regression-based delay-bounded routing protocols for VANETs

Routing protocols for vehicular ad hoc networks (VANETs) have attracted a lot of attention recently. Most of the researches emphasize on minimizing the end-to-end delay without paying attention to reducing the usage of radio. This paper focuses on delay-bounded routing, whose goal is to deliver messages to the destination within user-defined delay and to minimize the usage of radio because radio spectrum is a limited resource. The messages can be delivered to the destination by the hybrid of data muling (carried by the vehicle) and forwarding (transmitted through radio). In the existing protocol, a vehicle may only switch the delivery strategy (muling or forwarding) at an intersection according to the available time of the next road segment, which is between the current intersection and the next intersection. To improve previous works, our protocol uses linear regression to predict the available time and the traveling distance, and thus, the vehicle can switch to a proper delivery strategy at a proper moment and can reduce the number of relays by radio. Our protocol contains two schemes: the greedy and centralized schemes. The greedy scheme uses only the current sampling data to predict the available time and decide when to switch the delivery strategy, whereas the centralized scheme uses the global statistical information to choose a minimum-cost path. Simulation results justify the efficiency of the proposed protocol. Copyright © 2011 John Wiley & Sons, Ltd.

Efficient and multi-level privacy-preserving communication protocol for VANET

In this paper, we introduce an efficient and multi-level conditional privacy preservation authentication protocol in vehicular ad hoc networks (VANETs) based on ring signature. The proposed protocol has three appealing characteristics: First, it offers conditional privacy preservation authentication: while every receiver can verify that a message issuer is an authorized participant in the system only a trusted authority can reveal the true identity of a message sender. Second, it is equipped with multi-level countermeasure: each vehicle can select the degree of privacy according to its own requirements. Third, it is efficient: our system outperforms previous proposals in message authentication and verification, cost-effective identity tracking in case of a dispute, and low storage requirements. We demonstrate the merits gained by the proposed protocol through extensive analysis.

Intersection-Based Geographical Routing Protocol for VANETs: A Proposal and Analysis

This paper presents a class of routing protocols for vehicular ad hoc networks (VANETs) called the Intersection-based Geographical Routing Protocol (IGRP), which outperforms existing routing schemes in city environments. IGRP is based on an effective selection of road intersections through which a packet must pass to reach the gateway to the Internet. The selection is made in a way that guarantees, with high probability, network connectivity among the road intersections while satisfying quality-of-service (QoS) constraints on tolerable delay, bandwidth usage, and error rate. Geographical forwarding is used to transfer packets between any two intersections on the path, reducing the path's sensitivity to individual node movements. To achieve this, we mathematically formulate the QoS routing problem as a constrained optimization problem. Specifically, analytical expressions for the connectivity probability, end-to-end delay, hop count, and bit error rate (BER) of a route in a two-way road scenario are derived. Then, we propose a genetic algorithm to solve the optimization problem. Numerical and simulation results show that the proposed approach gives optimal or near-optimal solutions and significantly improves VANET performance when compared with several prominent routing protocols, such as greedy perimeter stateless routing (GPSR), greedy perimeter coordinator routing (GPCR), and optimized link-state routing (OLSR).

Binary-Partition-Assisted MAC-Layer Broadcast for Emergency Message Dissemination in VANETs

Vehicular ad hoc networks (VANETs) have recently been considered as an attractive network architecture to provide various services ranging from road safety to entertainment applications. In this paper, we propose an IEEE-802.11-based multihop broadcast protocol to address the issue of emergency message dissemination in VANETs. The protocol adopts a binary-partition-based approach to repetitively divide the area inside the transmission range to obtain the furthest possible segment. The forwarding duty is then delegated to a vehicle chosen in that segment. Aside from accomplishing directional broadcast for highway scenario, the protocol also exhibits good adaptation to complex road structures. The main focus of the paper lies in reducing broadcast delay, which is an important factor for time-critical safety applications. Most importantly, the contention delay remains almost constant, irrespective of vehicle density. Mathematical analysis is performed to assess the effectiveness of the protocol. Simulation results demonstrate that the proposed protocol imparts greater performance in terms of latency and message progress when compared with contemporary multihop broadcast protocols for VANETs.

Performance Analysis of On-Demand Routing Protocols for Vehicular Ad-Hoc Networks

Vehicular Ad Hoc Networks (VANETs) are a peculiar subclass of mobile ad hoc networks that raise a number of technical challenges, especially from the point of view of their mobility models. Currently, the field of VANETs has gained an important part of the interest of researchers and become very popular. More specifically, VANETs can operate without fixed infrastructure and can survive rapid changes in the network topology. The main method for evaluating the performance of routing protocols for VANETs by Network Simulator-2.34. This paper is subjected to the on-demand routing protocols with identical loads and evaluates their relative performance with respect to the two performance context: average End-toEnd delay and packet delivery ratio. We investigated various simulation scenarios with varying pause times, connections and no. of nodes particularly for AODV and DSR. We will also discuss briefly about the feasibility of VANETs in respect of Indian automotive networks.

Stimulating Cooperation in Vehicular Ad Hoc Networks: A Coalitional Game Theoretic Approach

In vehicular ad hoc networks (VANETs), because of the nonexistence of end-to-end connections, it is essential that nodes take advantage of connection opportunities to forward messages to make end-to-end messaging possible. Thus, it is crucial to make sure that nodes have incentives to forward messages for others, despite the fact that the routing protocols in VANETs are different from traditional end-to-end routing protocols. In this paper, we study how to stimulate message forwarding in VANETs. Our approach is based on coalitional game theory. In particular, we propose an incentive scheme for VANETs and rigorously show that with our scheme, faithfully following the routing protocol is in the best interest of each node. In addition, we extend our scheme to taking the limited storage space of each node into consideration. Experiments on testbed trace data verify that our scheme is effective in stimulating cooperation of message forwarding in VANETs.

A Novel Position-based Multi-hop Broadcast Protocol for Vehicular Ad Hoc Networks

Vehicular Ad Hoc Networks (VANETs) are considered as a promising scheme to actively guarantee vehicle safety, and broadcast is a key technology for warning message dissemination in VANETs. This paper proposes a novel Position-based Multi-hop Broadcast (PMB) protocol for VANETs in view of some shortcomings of existing broadcast protocols for VANETs, such as ignoring the differences of transmission range among different nodes (vehicles), and disseminating warning messages only with the help of nodes in the one-way lane, PMB calculates waiting time to select the rebroadcast nodes based on additional coverage area of adjacent nodes considering the transmission ranges of nodes together with the inter-vehicle spacing, to guarantee less nodes used to rebroadcast warning packets. Besides, it guarantees the reliability of warning message dissemination by adopting the alternative answering mechanism named implicit ACK and explicit ACK adaptively and rebroadcast packets based on nodes in the two-way lane. The simulation results show that PMB outperforms existing broadcast protocols for warning message dissemination in VANETs in terms of suppression of broadcast redundancy, real-time performance and reliability even if all nodes have different transmission ranges.

Time and Location-Critical Emergency Message Dissemination for Vehicular Ad-Hoc Networks

One promise of Vehicular Ad-hoc Networks (VANET) is to considerably increase road safety and travel comfort by enabling inter-vehicle communications. Among a vast array of potential applications, emergency message (EM) dissemination has attracted a lot of attention in the literature. In this paper, we propose a time/location-critical (TLC) framework for EM dissemination and use our scalable modulation and coding (SMC) scheme to achieve the goal. In specific, vehicles near the accident site (or the point-of-interest location) receive guaranteed, detailed messages to take proper reaction immediately (e.g., slow down or change lanes), and vehicles further away have a high probability to be informed and make location-aware decisions accordingly (e.g., detour or reroute), with the assistance of reverse traffic when possible and necessary. The efficacy of the proposed framework is analyzed and validated by extensive numerical and simulation results. The TLC framework and the use of the SMC scheme are shown to be able to disseminate EMs effectively and efficiently by taking both the time and location criticality into account, while simplifying the design of radio transceivers and media access control protocols for VANET.

Communication framework for vehicle ad hoc network on freeways

Providing an efficient and stable communication framework of Vehicular Ad hoc Network (VANET) is an emerging issue. Most of conventional VANET communication schemes only support short range transmission, vehicles need to relay traffic data or frequently switch to different roadside units. Such an ad hoc-based method suffers a high jitter delay and makes it difficult to develop travel and real-time multimedia services, such as traffic information dissemination and fleet management. Fortunately, existing novel wireless technologies, e.g. WiMAX mobile multi-relay (MMR), provide long transmission range and high transmission rate in mobile environments. This study presents a Safety/Vehicular Information Delivery (SVID) framework, an application-layer VANET communication protocol. A power-abundant, large size vehicle, called SIP-based relay vehicle (SRV), e.g. long distance transportation bus, plays as a relay station (RS) providing the connectivity to other small vehicles around it. To provide VANET services in SVID, this work adopts a SIP-based mechanism. The proposed scheme can provide more efficient communication than conventional VANET ad hoc mode. Simulation results show that the proposed scheme achieves a low SIP transaction time, jitter delay, frame loss rate while avoiding the broadcast storm problem.

Vehicular ad hoc networks (VANETS): status, results, and challenges

Recent advances in hardware, software, and communication technologies are enabling the design and implementation of a whole range of different types of networks that are being deployed in various environments. One such network that has received a lot of interest in the last couple of years is the Vehicular Ad-Hoc Network (VANET). VANET has become an active area of research, standardization, and development because it has tremendous potential to improve vehicle and road safety, traffic efficiency, and convenience as well as comfort to both drivers and passengers. Recent research efforts have placed a strong emphasis on novel VANET design architectures and implementations. A lot of VANET research work have focused on specific areas including routing, broadcasting, Quality of Service (QoS), and security. We survey some of the recent research results in these areas. We present a review of wireless access standards for VANETs, and describe some of the recent VANET trials and deployments in the US, Japan, and the European Union. In addition, we also briefly present some of the simulators currently available to VANET researchers for VANET simulations and we assess their benefits and limitations. Finally, we outline some of the VANET research challenges that still need to be addressed to enable the ubiquitous deployment and widespead adoption of scalable, reliable, robust, and secure VANET architectures, protocols, technologies, and services.

Balancing broadcast reliability and transmission range in VANETs

A novel transmit power control protocol for vehicular ad-hoc networks (VANETs) called Efficient Transmit Power Control (ETPC) is proposed in this poster. It aims to improve the reliability of safety-critical broadcasts while also maximizing the transmission range. On one hand, large transmission ranges are often desirable to ensure that safety-critical messages reach as many vehicles as possible. On the other hand, they also lead to increased channel contention and packet collisions, especially in dense networks. As a consequence, this work proposes an adaptive transmit power control approach that balances these two conflicting goals. The approach incurs minimum additional overhead (since it is primarily based on simple overhearing) and works well in both highway and urban traffic scenarios.