Multiagent Based Information Dissemination in Vehicular Ad Hoc Networks

Vehicular Ad Hoc Network (VANET) has become an active area of research, standardization, and development because next generation vehicles will be capable of sensing, computing, and communicating. Different components in a vehicle constantly exchange available information with other vehicles on the road and cooperate to ensure safety and comfort of users using VANET. In VANET, information like navigation, cooperative collision avoidance, lane changing, speed limit, accident, obstacle, or road condition warnings, location awareness services, etc. play a significant role in safety-related applications. Safety related information dissemination is challenging due to the delay-sensitive nature of safety services. In this chapter, the authors survey some of the ongoing recent research efforts in information dissemination in VANETs. They also outline some of the research challenges that still need to be addressed to enable efficient information dissemination in VANET.

Connected vehicles are revolutionizing the way in which transport and mobility are conceived. The main technology behind is the so-called Vehicular Ad-Hoc Networks (VANETs), which are communication networks that connect vehicles and facilitate various services. Usually these services require a centralized architecture where the main server collects and disseminates information from/to vehicles. In this paper, we focus on improving the downlink information dissemination in VANETs with this centralized architecture. With this aim, we model the problem as a Vertex Covering optimization problem and we propose four new nature-inspired methods to solve it: Bat Algorithm (BA), Firefly Algorithm (FA), Particle Swarm Optimization (PSO), and Cuckoo Search (CS). The new methods are tested over data from a real scenario. Results show that these metaheuristics, especially BA, FA and PSO, can be considered as powerful solvers for this optimization problem.

Localization in Vehicular Adhoc Networks (VANETs) has witnessed significant attention due the instantaneous failure of Global Positioning System (GPS). Performance of Intelligent Transport Systems (ITS) applications is based on efficient and reliable information dissemination techniques. Efficiency and reliability of information dissemination is dependent on the availability of accurate location information about vehicles. Most of the localization techniques suggested in the past are based on either real time radio signal measurement or Road Side Unit (RSU). Signal measurement is performed in terms of Time of Arrival (ToA) or Received Signal Strength Indicator (RSSI) which is susceptible to measurement error due to the high mobility of vehicles in vehicular traffic environment. Availability of RSU can not be guaranteed. This paper proposes a Geometry based Inter Vehicle Distance (Geo-IVD) calculation techniques which can be utilized for information dissemination in VANETs. Geo-IVD is a cooperative technique which utilizes past and present knowledge about the vehicle. It utilizes mathematical geometry to calculate present unknown location of a vehicle. More specifically, Geo-IVD find the current unknown location of a vehicle considering two cases. In the first case, vehicle's current direction is considered to be the same or opposite from its past direction. In the second case, vehicle's current direction is considered different (other than opposite) from its past direction. Mathematical geometry is utilized to solve the problem of finding current location in both these cases. Simulations are carried out in ns2 and results are comparatively analyzed with that of the state-of-the-art technique: ToA-IVD. Analysis of results attests the superiority of Geo-IVD to the state-of-the-art technique.

A type of ad hoc network formed among moving vehicles that come in one another’s radio transmission range is called Vehicular Ad Hoc Network (VANET). VANET may be deployed using three architectures: pure ad hoc, WLAN and hybrid. Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I) are the two modes in VANET used for communication among vehicles. These features not only distinguish a VANET from other ad hoc networks but also make these networks more exposed to attacks and increase their complexity. These networks being the primary mechanism for communication in VANETs, appropriate and timely delivery of information is of prime importance. Due to the existence of various vehicular traffic scenarios, a single category of routing protocols is not sufficient for the VANETs. Therefore, various categories of routing protocols have been tailored to meet specific kinds of routing requirements in this framework. Most significant ones are ad hoc/topology-based, position-based, geocast-based, cluster-based, broadcast-based protocols. There exist a number of attacks that apart from affecting various other parameters also affect the routing protocols in these VANETs. Most of these attacks may be launched in all the above-mentioned three architectures. But, one of the most dangerous attacks is the Sybil attack that may be initiated in pure ad hoc deployment of VANET where vehicles communicate with one another in one to one manner using carry forward approach. In this paper, with the help of illustrative example for each of the five categories of routing protocols, we show how Sybil attack affects these protocols. Considering the ad hoc scenarios in VANETs, we also discuss a prevention mechanism for the Sybil attack briefly.

VANET (Vehicular Ad-hoc Network) is an ad-hoc wireless network which nodes are composed by mostly moving vehicles and infrastructure communications or access points along the road. It integrates adhoc networking, cellular technology, wireless LAN and other technologies, which include GPS(Global Positioning System), digital mapping, sensing technologies and advanced information processing tools to support Intelligent Traffic Systems (ITS). VANET is developed mainly to improve road safety and to increase the traffic efficiency. It is designed to support the exchange of warning messages among the vehicles to increase the passenger safety and other information related to VANET applications and services . To achieve these goals, there are several issues that should be addressed. One of these challenges is designing reliable and efficient Medium Access Control (MAC) protocol for VANET. Due to VANET’s distinguishing characteristics, such as high mobility of the nodes, dynamic network topology, enough battery power, high processing power, etc, the MAC protocols designed for MANET (Mobile Ad-hoc Network) are not suitable for VANET. The research community has been working to develop MAC protocols appropriate for this ad-hoc network by proposing new design or modifying the existing one.In this paper, the VANET’s architecture, characteristics, applications and standard are discussed and then a comprehensive study of several MAC protocols available in the literature is presented.

Vehicular Ad Hoc Networks (VANETs) are based on network technology where cars act as mobile nodes to form a communication network. In VANETs, routing protocols have a significance regarding the overall network performance since they determine the way of sending and receiving packets between mobile nodes. Most of the protocols proposed for VANETs are adapted from Mobile ad hoc networks (MANETs) routing protocols. However, due to the specific characteristics of VANETs, especially high mobility, and dynamic topology, the routing protocols in ad hoc networks do not adapt immediately to VANETs. Therefore, secure routing of Vehicular ad hoc networks (VANETs) against attacks, which are of various types, is still a challenging issue. This paper is going to present a synthesis of the most relevant protocols that have addressed the secure routing issue in VANETs. It also establishes a comparison regarding the offered features and the studied performance aspects through which it is notified that a security mechanism depends not only on the level of efficiency but also on the network constraints.

Vehicular ad hoc networks (VANETs) are a special form of wireless networks made by vehicles communicating among themselves on roads. The conventional routing protocols proposed for mobile ad hoc networks (MANETs) work poorly in VANETs. As communication links break more frequently in VANETs than in MANETs, the routing reliability of such highly dynamic networks needs to be paid special attention. To date, very little research has focused on the routing reliability of VANETs on highways. In this paper, we use the evolving graph theory to model the VANET communication graph on a highway. The extended evolving graph helps capture the evolving characteristics of the vehicular network topology and determines the reliable routes preemptively. This paper is the first to propose an evolving graph-based reliable routing scheme for VANETs to facilitate quality-of-service (QoS) support in the routing process. A new algorithm is developed to find the most reliable route in the VANET evolving graph from the source to the destination. We demonstrate, through the simulation results, that our proposed scheme significantly outperforms the related protocols in the literature.

A survey on authentication schemes in VANETs for secured communication

Vehicular Ad Hoc Networks (VANET) are key to realizing Intelligent Transportation Systems (ITS). Although VANETs belong to the class of Mobile Ad Hoc Networks (MANET), and there are numerous routing protocols for MANETs, none of these protocols are applicable for VANETs. In particular, VANETs are highly dynamic due to high speed mobility of vehicles and traditional routing algorithms for MANETs cannot deal with such dynamicity of network nodes. Several comparative studies have suggested AODV (Ad hoc On-Demand Distance Vector), a well known MANET protocol that is adaptive to dynamic changes in network and makes efficient utilization of network resources, to be the best candidate for dealing with VANETs. However, verbatim adoption of AODV is not an efficient routing solution for VANETs. Recent works therefore proposed various modifications and/or additions to AODV to make it suitable for VANETs. It is particularly important to control congestion in VANETs by efficiently dealing with the AODV "Route Request" (RREQ) packets. In this paper, we propose Pro-AODV (Proactive AODV), a protocol that uses information from the AODV routing table to minimize congestion in VANETs, yet sustains other performance metrics at acceptable levels. The novelty and elegance in Pro-AODV comes from the fact that it does not require the execution of any additional logic, it is sufficient to know only the size of the routing table at each node.

The availability of more realistic road conditions and dynamics provides sound ground to study the issues of Vehicular ad-hoc Network (VANET). In this chapter a new heterogeneous traffic flow based mathematical model is presented, to gain the time and space dynamics of vehicles. To achieve more accurate and realistic data about road conditions, microscopic parameters of varying safety distance between the vehicles and vehicular length are considered in the model. The density dynamics under different road scenarios are calculated under the influence of these constraints with the use of a defined mathematical model. The model is able to capture the impact of road constraints such as traffic lights and road incidents, on the traffic flow. The concept of Vehicular Ad-hoc Networks (VANET) has given mankind opportunities for secure and safe journeys on the roads. VANET is defined as a subclass of Mobile Ad-hoc Networks which holds the characteristics of ad-hoc networks. However due to the dynamic road conditions, traffic flow theory concepts, mobility constraints, human behaviours and vehicular characteristics VANET exhibits different dynamics. These factors have strong influences on the VANET architecture from physical to application layers. This highlights different areas of interest in VANET for researchers to investigate. This study aims to capture the impact of traffic flow theory constraints on the vehicular density under the heterogeneous traffic flow on the road. The microscopic and macroscopic characteristics of vehicles moving on the roads are utilized for the improvement of VANET connectivity dynamics.

In this paper we consider information dissemination in vehicular ad-hoc networks (VANETs) in city scenarios. Information dissemination is an important building block of many proposed VANET applications. These applications need a certain dissemination performance to work satisfactorily. This is critical during the rollout of VANETs, when only few cars participate. After analytical considerations, we focus on simulations using a detailed model of a whole city. We assess the dissemination performance depending on the amount of equipped vehicles on the road. For few equipped vehicles, we show that dissemination speed and coverage will not be sufficient. Therefore, we propose to use specialized, but simple and cheap infrastructure, stationary supporting units (SSUs). If a small number of SSUs is installed in a city and connected via some backbone network, the dissemination performance improves dramatically, especially during the VANET rollout phase. Thus, SSUs allow for a faster and earlier rollout of working, dissemination-based VANET applications

Fog computing for vehicular Ad-hoc networks: paradigms, scenarios, and issues

A comparative classification of information dissemination approaches in vehicular ad hoc networks from distinctive viewpoints: A survey

Vehicular Ad-hoc networks (VANETs) have been around for some time and are still attracting research. VANETs are one of the ad hoc networks real-life applications, where vehicles communicate which each other and with fixed components known as roadside units. VANETs have unique characteristics and requirements which differ from those in standard ad-hoc networks, but the security remains a major challenge because of the very dynamic topology and the lack of infrastructure. In this autonomous and auto-organized environment, the question of whom to trust and for what becomes very important and difficult to answer. This paper addresses the issues associated with establishing trust between peers in VANET. It defines, discusses and evaluates various trust management approaches and how well they address VANET requirements. The paper also proposes criteria for assessing the effectiveness of trust management models with regards to challenges specific to VANETs.

Kinetic mobility management applied to vehicular ad hoc network protocols