Nodes In Vehicular Ad Hoc Networks Research Articles

Countermeasures to avoid noncooperation in fully self-organized VANETs.

The secure and efficient exchange of information in vehicular ad hoc networks (VANETs) involves more challenges than in any other type of ad hoc networks. This paper proposes a new vehicular communication system based on mobile phones for fully distributed and decentralized networks. In these networks, communications depend on individual nodes, which could decrease the efficiency and reliability of transmitted information. Besides, the limitation in the resources of mobile devices is an additional obstacle in the forwarding problem, and the content of the information generated by individual nodes must be considered inherently unreliable. In particular, this paper proposes the application of groups as a basis structure for a cooperation mechanism useful in event generation and in packet retransmission. Its aim is to promote the involvement of nodes in network performance. Given that such participation involves consumption of node resources, a group-based structure is here used not only to reduce communication overload but also to prevent sending false information and to encourage nodes in relaying packets. Several simulations of the proposal have been done, and the results have confirmed that this is a promising approach to increase network efficiency and trust in transmitted information, while reducing the number of selfish nodes in VANETs.

A systematic review on routing protocols for Vehicular Ad Hoc Networks

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.

Performance Evaluation of Zrp Star and Dsr under Vanet's

Vehicular Ad-hoc Network (VANET) is an extraordinary manifestation of MANET which is a vehicle to vehicle & vehicle roadside remote correspondence system, where nodes in VANET include themselves as servers or clients for trading & offering data. VANET (Vehicular Ad-hoc Network) could be another innovation that has taken gigantic consideration in the late years. Because of the quick topology the element cohort degreed incessant separation and it troublesome to style an efficient directing convention for steering data around vehicles, Vehicular Ad-hoc Network (VANET) could be a system of self sorted out vehicles and way side framework human movement with each one in turn over remote, with a read to support activity well being and intensity. Data exchanged over Vanets ordinarily assumes a significant part in movement well being. Such data ought to be right and truthful, as it rely on the requisition and verification is important administrations for activity security in Vanets. This paper is for the most part proposed to enhance the Quality of services (QOS ) in vehicular Ad-hoc Network by breaking down parameters like throughput, End-to-End Delay, Average jitter, and so forth in conventions like ZRP, STAR and DSR by utilizing the Qualnet 5.0.1 test system.

Performance and Comparative Analysis of ADSA in a Vehicular Network: MAC Approach in IEEE 802.11p

Vehicular network (VN) technologies have become an attractive area of attention all over the world. Two factors that have contributed in the development, design and implementation of the VN standards include the need to ensure safety and the need to consider road accident avoidance strategies. However, the innate dynamic and the high topological mobility of the nodes in Vehicular Ad Hoc Networks (VANETs) raise complex and challenging issues with the standard. One of the complexities is the problem posed by Doppler Effect (DE) resulting from the high mobility of the VANET nodes. In an attempt to compensate the induced Doppler Shift (DS), Automatic Doppler Shift Adaptation (ADSA) was recently introduced to combat DE in a VANET. ADSA proved to be more resilient and effective in term of Bit Error Rate (BER). Moreover, for realistic applications, BER tests alone are insufficient. Therefore, this work explores the strength of the refined ADSA method in terms of throughput and presents a comparative analysis of ADSA versus Adaptive Modulation Code (AMC) and Auto-Rate Fallback (ARF). Results from the analysis shows that the ADSA approach demonstrates strong robustness compared to AMC and ARF with up to 44 to 55% improvement in throughput and a 174 to 182% reduction in consumed time.

Vehicular Networking Enhancement And Multi-Channel Routing Optimization, Based on Multi-Objective Metric and Minimum Spanning Tree

Vehicular Ad hoc NETworks (VANETs) represent a particular mobile technology that permits the communication among vehicles, offering security and comfort. Nowadays, distributed mobile wireless computing is becoming a very important communications paradigm, due to its flexibility to adapt to different mobile applications. VANETs are a practical example of data exchanging among real mobile nodes. To enable communications within an ad-hoc network, characterized by continuous node movements, routing protocols are needed to react to frequent changes in network topology. In this paper, the attention is focused mainly on the network layer of VANETs, proposing a novel approach to reduce the interference level during mobile transmission, based on the multi-channel nature of IEEE 802.11p (1609.4) standard. In this work a new routing protocol based on Distance Vector algorithm is presented to reduce the delay end to end and to increase packet delivery ratio (PDR) and throughput in VANETs. A new metric is also proposed, based on the maximization of the average Signal-to-Interference Ratio (SIR) level and the link duration probability between two VANET nodes. In order to relieve the effects of the co-channel interference perceived by mobile nodes, transmission channels are switched on a basis of a periodical SIR evaluation. A Network Simulator has been used for implementing and testing the proposed idea.

Directed information dissemination in vehicular ad-hoc networks

In this article, we utilize the idea of multipoint relays (MPRs) found in literature (Jacquet et al. in Proceedings of IEEE INMIC, 2001), to propagate accident information in a restricted way (e.g., only backwards). We devise an algorithm to identify MPRs that are geographically situated behind a particular node using only its neighbor table, and speed information of the neighboring vehicles. With the identification of the backward MPRs, it is possible to restrict the information dissemination to vehicles behind a particular vehicular ad-hoc network (VANET) node only. This might benefit the approaching vehicles so that the driver could take preventive measures in real-time since he/she will have an indication of the severity of road conditions ahead. We assume that there exists an inter vehicular network using optimized link state routing (OLSR) where accident information can be propagated to all nodes using on-going OLSR control packets. We envision our application will run on top of existing routing protocols (e.g., OLSR), thereby resulting in very little integration effort, and retaining OLSR’s reduced network traffic advantage through the use of MPRs. We analyze our back MPR identification algorithm in a detailed manner. We also show that by using our approach the location of the accident alert instigator node could be pinpointed if a subset of the nodes in the same VANET know their geographical positions. We use VANET mobility models generated by SUMO into NS-3 for our simulations, and also perform preliminary experiments to verify the algorithm’s effectiveness. Our analysis and experiments show favorable results.

Detecting Hot Road Mobility of Vehicular Ad Hoc Networks

Vehicular Ad Hoc Networks (VANETs) can provide value-added services to both drivers and passengers with on-board vehicular communication systems. Node mobility and volatile wireless connection in VANETs affect inter-contact time (TI) between mobile nodes, which greatly degrades the performance of vehicular applications. Nevertheless, the node spatial distribution in VANETs is another important factor especially in real applications. It positively affects the inter-contact time of vehicular nodes. By leveraging it, we can significantly improve the performance of data transmissions and inter-vehicle communication. To this end, we investigate the data collected from around 4,000 taxisin Shanghai and propose in this paper an efficient hot road mobility model. We find that most taxis distribute on some hot roads, which makes the node spatial distribution follow the power law. Based on this observation, we propose the concepts of indirect contact and heterogeneous inter-contact time (TH) to reveal how hot roads can change the distribution of inter-contact time. We find that the tail distribution of TH also appears the power law, and both node spatial distribution and TH distribution decay at least as the power law. We further propose a model for detecting vehicle mobility in hot roads, which can generates synthetic traces that captures both spatial and temporal features of nodes in VANETs.

SDR: A Stable Direction-Based Routing for Vehicular Ad Hoc Networks

A stable and reliable routing mechanism for vehicular ad hoc networks (VANETs) is an important step toward the provision of long data transmission applications, such as file sharing and music download. Traditional mobile ad hoc network (MANET) routing protocols are not suitable for VANET because the mobility model and environment of VANET are different from those of traditional MANET. To solve this problem, we proposed a new stable routing algorithm, called stable directional forward routing. The novelty of the proposed routing protocol is its combining direction broadcast and path duration prediction into ad hoc on-demand distance vector routing protocols, which including: (1) Nodes in VANET are grouped based on the position, only nodes in a given direction range participating in the route discovery process to reduce the frequency of flood requests, (2) Route selection is based on the link duration while not the hops or other metrics to increase the path duration, (3) Route discovery is executed before the path expiration in order to decrease the end to end delay. The performance of the new scheme is evaluated through extensive simulations with Qualnet. Simulation results indicate the benefits of the proposed routing strategy in terms of decreasing routing control packet, reducing the number of link-breakage events, improving the packet delivery ratio and decreasing the end-to-end delay.

A novel algorithm to form stable clusters in vehicular ad hoc networks on highways

Clustering in vehicular ad hoc networks (VANET) is one of the control schemes used to make VANET global topology less dynamic. Many of the VANET clustering algorithms are derived from mobile ad hoc networks (MANET). However, VANET nodes are characterized by their high mobility, and the existence of VANET nodes in the same geographic proximity does not mean that they exhibit the same mobility patterns. Therefore, VANET clustering schemes should take into consideration the degree of the speed difference among neighboring nodes to produce relatively stable clustering structure. In this paper, we introduce a new clustering technique suitable for the VANET environment on highways with the aim of enhancing the stability of the network topology. This technique takes the speed difference as a parameter to create relatively stable cluster structure. We also developed a new multi-metric algorithm for cluster-head elections. A simulation was conducted to evaluate our method and compare it with the most commonly used clustering methods. The simulation results show that our technique provides more stable cluster structure on the locale scale which results in a more stable network structure on the global scale. The proposed technique reduces the average number of clusters changed per vehicle by 34-46%, and increases the average cluster lifetime by 20-48% compared to the existing techniques.

Hardware Design of Noble MAC Protocol for Vehicle System

Vehicular ad hoc networks (VANETs) are being designed to improve traffic safety and efficiency. Then it communicates with each other using sensed available spare spectra. In a VANET network, a medium access control (MAC) layer configuration determines a common set of channels to facilitate communication among participating nodes. Because spare spectra change dynamically according to time and locations, available spare channels of the number and the identity of each node are changing any time in a multi-hop network consisting of VANET nodes. In this paper, we present a novel dynamic hop reservation multiple access protocol based on the original one. Moreover, the MAC system is designed using Verilog HDL and implemented using ALTERA Excalibur ARM EPXA4F672C3 (FPGA). It can access and quit channels efficiently without any common channel.

LEAPER: A lightweight reliable and faithful data packet relaying framework for VANETs

In vehicular ad hoc networks (VANETs), it is vital to ensure reliable and faithful data packet relaying over multiple hops, which is critical to many VANET applications. In this paper, a novel Adaptive Role Playing (ARP) strategy is proposed to enable VANET nodes in each hop to countermeasure the malfunctions and misbehaviors of individual nodes. A lightweight reliable faithful data packet relaying framework (LEAPER) is proposed to implement the ARP strategy in each hop, so that each hop can reliably relay the authentic data packet to the next hop. Hop by hop, LEAPER ensures reliable and faithful data packet relaying from the source to the destination. In each hop the required security strength is configurable, making LEAPER flexible and adaptive to various application scenarios. Theoretical analysis and simulation studies show that LEAPER outperforms existing schemes in ensuring reliable and faithful data packet relaying.