A Survey on Information Dissemination in VANETs

Vehicular Ad hoc Networks (VANETs) are a compelling application of ad hoc networks, because of the potential to access specific context information (e.g. traffic conditions, service updates, route planning) and deliver multimedia services (Voice over IP, in-car entertainment, instant messaging, etc.). This paper proposes an agent based information dissemination model for VANETs. A two-tier agent architecture is employed comprising of the following: 1) 'lightweight', network-facing, mobile agents; 2) 'heavyweight', application-facing, norm-aware agents. The limitations of VANETs lead us to consider a hybrid wireless network architecture that includes Wireless LAN/Cellular and ad hoc networking for analyzing the proposed model. The proposed model provides flexibility, adaptability and maintainability for traffic information dissemination in VANETs as well as supports robust and agile network management. The proposed model has been simulated in various network scenarios to evaluate the effectiveness of the approach.

Today’s vehicles have capability of sensing, computing, and communicating capabilities. Different embedded components in a vehicle constantly exchange available information among them as well as with other vehicles on the road for cooperative, driving safety and comfort known as Vehicular Ad hoc Network (VANET). In VANET, critical information like navigation, cooperative collision avoidance, lane-changing, speed limit, accident, obstacle or road condition warnings, etc. play a significant role for safety-related applications. Such kind of critical information gathering and dissemination is challenging, because of their delay-sensitive nature. In this position paper, we propose a cognitive agent based framework (using Belief Desire Intention model) that consists of heavy-weight static and light-weight mobile agents. Proposed framework executes push (gather/store and disseminate) and pull (gather/store) operations on information gathered based on information relevance and importance. We provide a model to explore the gathering and dissemination capacity of the cognitive agent framework.KeywordsVehicular ad hoc networksCognitive agentsBDI architectureBayesian network learning

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.

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.

Mobile ad hoc networks (MANETs), which are a promising method for the intelligent transportation system, include vehicular ad hoc networks (VANETs) (ITS). Developing reliable and strong cooperative collision avoidance (CCA) strategy to mitigate the growing number of road fatalities each year is one of the main difficulties facing vehicular ad hoc networks (VANETs).A proper and successful routing method aids in the successful expansion of vehicular ad hoc networks. This study explains the architecture, interface layers, safety features, and implementation of a novel priority-based direction-aware collision avoidance system (P-DVCA). It distinguishes our study in the collision area of VANETs by accounting for realistic bi-directional traffic. The scheme begins with the development of dynamic clusters, which is difficult because of the bi-directional diverse traffic and the need to avoid collisions within and between clusters. The target node is sent an early warning message that includes the safe speed and the likelihood of a collision in order to notify it of an impending danger. To determine the least expensive, shortest one with the fewest hops between the source and the endpoint. A crucial problem with VANETs is the transmission of data from a source node to the base station. Cross-layer issues must be solved for a robust and stable collision avoidance programme to function properly in a VANET communication architecture. The results of the simulation show that the suggested scheme significantly outperforms CCM and C-RACCA in terms of cluster stability, fewer collisions, low latency, and low communication overhead. According to the findings, P-DVCA offers stable clustering, minimises network congestion, and lowers communication overhead and latency.

Information dissemination in vehicular ad hoc networks (VANETs) is inseparable from the interaction between vehicles and infrastructure. The trust authority (TA) often plays a pivotal role in VANETs and requires interaction with multiple vehicles. However, when the TA sends the same message to multiple vehicles, there are many redundancies, as it needs to negotiate with each vehicle and send them different ciphertexts. This greatly reduces the work efficiency of the TA. To the best of our knowledge, there is no research on the problem of redundancy that occurs when the same message is sent to multiple vehicles in VANETs. The proposed scheme adopts identity-based broadcast encryption (IBBE) technology, which is a secure data-sharing scheme suitable for the vehicle-to-infrastructure communication mode, in VANETs for the first time. Thus, with only one encryption, the TA can generate a fixed-length ciphertext for a group of vehicles. When there are new vehicles that subsequently request a service, the TA can assign encryption tasks to the proxy server. In terms of security, our scheme meets the particular requirements of VANETs. The encryption overhead of the sender and the length of the ciphertext were comparatively analyzed. The results demonstrated that the performance of the scheme improved significantly. Thus, our scheme can prevent redundancies and effectively improve the work efficiency of TA.

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

Road safety applications envisaged for vehicular ad hoc networks (VANETs) depend largely on the exchange of messages to deliver information to concerned vehicles. Safety applications as well as inherent VANET characteristics make data dissemination an essential service and a challenging task. We are developing a decentralized efficient solution for broadcast data dissemination through two game-theoretical mechanisms. Besides, VANETs can also include autonomous vehicles (AVs). AVs might represent a revolutionary new paradigm that can be a reality in our cities in the next few years. AVs do not need a driver to work; instead, they should copy a proper human behavior to adapt the driving according to the current circumstances, such as speed limit, pedestrian crossing street or wheather conditions. We will develop an AV software module including artificial intelligence (AI) techniques so that AVs can interact with the dynamic scenario throughout time. Finally, we also will include electrical vehicles (EV) in the VANET, so that special services such as finding and reserving an EV charging station place will be welcome. In addition, we are developing a multimetric geographic routing protocol for VANETs to transmit H.265 video (traffic accident, traffic state, commercial….) over VANETs.

The vehicular ad hoc network (VANET) is a wireless technology adopted by the research community to implement smart transportation applications. Due to the variation in the vehicular speed, topology in the VANET continuously changes that make a routing complex task. It is better to use the position-based routing protocol that is adaptive and mostly suitable for dynamically changing road environments. The objective of the paper is to analyze an impact of real mobility traces on position-based routing protocols using simulation. It is difficult to perform a simulation in the VANET due to the restricted movement of vehicles. Vehicular mobility plays a major role in the VANET. Realistic mobility traces such as intelligent driver model-intersection management (IDM-IM), IDM–lane changing (LC) and ManhattanGrid are generated using VANETMobiSim and Bonnmotion tool. These traces are applied to the intersection-based routing (IBR), greedy perimeter stateless routing (GPSR) and ant colony optimization-intersection-based routing (ACO-IBR). The impact of the mobility traces has been evaluated with parameters such as delay, throughput and successful delivery ratio (SDR). The result shows that the selection of proper mobility pattern is a key to achieve the realistic performance of the simulation. ACO-IBR minimizes delay and produces better successful delivery ratio and throughput for all real mobility patterns.

A Vehicular Ad-Hoc Networks (VANETs) is the technology that uses moving cars as nodes in a network to create a mobile network. VANETs turn every participating car into a wireless router, allowing cars of each other to connect and create a network with a wide range. VANETs are developed for enhancing the driving safety and comfort of automotive users. The VANETs can provide wide variety of service such as Intelligent Transportation System (ITS) e.g. safety applications. Many of safety applications built in VANETs are required real-time communication with high reliability. One of the main challenges is to avoid degradation of communication channels in dense traffic network. Many of studies suggested that appropriate congestion control algorithms are essential to provide efficient operation of the network. However, most of congestion control algorithms are not really applicable to event-driven safety messages. In this paper we propose congestion control algorithm as solution to prevent congestion in VANETs environment. We propose a complete validation method and analyse the performance of our congestion control algorithms for event-driven safety messages in difference congested scenarios. The effectiveness of the proposed congestion control algorithm is evaluated through the simulation using Veins simulator.

Vehicular Ad Hoc Network (VANET) is a promising area of research and development as it has remarkable role in improving safety of vehicles on road, efficient traffic management, and providing comfort to commuters. The typical characteristics of VANET environment pose several challenges for VANET application developers. There is always a demand for scalable communication mechanisms suitable for low- and high-speed vehicles, information dissemination techniques that suit sparse and dense traffic conditions. Thus, the reliability of any VANET application strongly depends upon the robustness of the underlying communication architecture. Any VANET communication model shall strictly adhere to the wireless access standards and specifications laid down for vehicular communications. In this work, we have designed and implemented a basic VANET communication model that facilitates both Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) communication adhering to IEEE 802.11p standards. The Physical and Link Layer extensions of WAVE standard have been integrated to EXata5.1 (network emulator) to support IEEE 802.11p communication. Necessary Graphical User Interface and library level extensions were made to create VANET scenarios. To demonstrate and evaluate our communication model, urban scenarios with different node densities were created in EXata. The communication scenarios were emulated with predefined mobility of nodes, CBR as the traffic application and Bellman Ford as the default routing protocol. Using EXata analyzer, the performance metrics were analyzed and found that our basic VANET communication model offers good throughput at high vehicle densities with a soft delay constraint.

Vehicular ad hoc networks (VANETs) are expected to offer both safety-related applications and user applications for vehicular users. In this paper, we consider a VANET scenario where one source vehicle (SV) tends to transmit real-time messages such as security related information to its destination vehicle (DV). We assume that the DV is out of the one hop range of the SV, and study the routing algorithm between the SV and DV. Stressing the importance of transmission delay, we formulate the end-to-end transmission delay between the SV and DV as the total transmission delay experienced at intermediate relay vehicles (RVs) along the transmission route, and design an optimization problem which minimizes the end-to-end transmission delay subject to routing selection constraints. To tackle the difficulties in evaluating the transmission performance of intermediate RVs, we apply stochastic network calculus theory. By modeling the stochastic arrival curve of the SV and the stochastic service curve of the RVs, the transmission delay at each intermediate RV can be examined. We then map the network scenario as a weighted graph and apply Dijkstra algorithm to obtain the optimal route between the SV and DV. Numerical results demonstrate the effectiveness of the proposed algorithm.

The vehicular ad hoc networks (VANETs) are characterized by high mobility of nodes, which resulting in frequent and fast changes in the network topologies. To make sure the messages are received efficiently and reliably, particularly for safety applications, broadcasting is the most natural and promising approach. Besides the efficiency, security is another important issue for VANETs. Because the open nature of VANETs make it simple for malicious users to disrupt the system or lead to accidents. In this paper, we propose a PKI-based Multihop Broadcasting Protocol (PMBP), which aims at providing authenticated, integrated, non-repudiated vehicular communication. The authentication scheme is based on the Elliptic Curve Digital Signature Algorithm (ECDSA) method. To provide an efficient trusted broadcasting scheme, two strategies are adopted: only the message originator signs the message, one message only be rebroadcasted once by each vehicle. Experimental results prove that this protocol is efficient enough to support safety related vehicular applications.

Vehicular Ad hoc Networks (VANETs) have become a cornerstone component of Intelligent Transportation Systems (ITS). VANET applications present a huge potential for improving road safety and travel comfort, hence the growing interest of both academia and industry. The main advantage of VANETs is its ad hoc nature which does not require fixed infrastructure or centralized administration. However, designing scalable information dissemination techniques for VANET applications remains a challenging task due to the inherent nature of such highly dynamic environments. Existing dissemination techniques often resort to simulation for performance evaluation and there are only few studies that offer mathematical modeling. In this paper we provide a comparative study of existing performance modeling approaches for data dissemination techniques designed for different VANET applications.

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