Trust-Based Routing in Software-Defined Vehicular Ad Hoc Networks

Vehicular ad-hoc network (VANET) technology enables communication between vehicles, or vehicles and road-side units (RSUs) through wireless communication devices installed on the vehicles. One of the most important goals of VANETs is providing safety applications for passengers. In addition, VANETs provide comfort applications to users. Guaranteeing a reliable and stable routing protocol over VANETs is a very important step. The proposed research attempts to improve routing protocols that decrease the end-to-end delay to suit VANET communication characteristics. In addition, it proposes analysis of the end-to-end delay probability distribution. More specifically, we derive a closed-form expression for the probability distribution of the re-healing delay in a VANET conditioned on the distance between two VANET clusters. Furthermore, we propose a closed-form expression for the probability distribution of the unconditional re-healing delay. Moreover, we develop a mathematical model to calculate the probability distribution of the end-to-end delay. On the other hand, using Unmanned Aerial Vehicles (UAVs) or drones in wireless communications and Vehicular Ad-hoc Networks (VANETs) has started to attract attention. We propose a routing protocol that uses infrastructure drones for boosting VANET communications to achieve a minimum vehicle-to-drone packet delivery delay. In addition, we propose a closed-form expression for the probability distribution of the vehicle-to-drone packet delivery delay on a two-way highway. Moreover, based on that closed-form expression, we can calculate the minimum drone density (maximum separation distance between two adjacent drones) that stochastically limits the worst case of the vehicle-to-drone packet delivery delay. Furthermore, we propose a drones-active service (DAS) that is added to the location service in a VANET. This service dynamically and periodically obtains the required number of active drones based on the current highway connectivity state by obtaining the maximum distance between each two adjacent drones while satisfying a probabilistic constraint for vehicle-todrone packet delivery delay. Our analysis focuses on two-way highway VANET networks with low vehicular density. The simulation results show the accuracy of our analysis and reflect the relation between the drone density, vehicular density and speed, other VANET parameters, and the vehicle-to-drone packet delivery delay. In addition, we propose a new routing protocol called multi-copy intersection-based routing (MCIR) for vehicular ad-hoc networks (VANETs) in urban areas. MCIR is an intersectionbased routing protocol that forwards multiple copies of the packets in different road segments. Moreover, it is a beacon-less routing protocol with a carry-and-forward strategy. We show via simulation that the MCIR protocol is superior to other existing routing protocols, especially in low vehicular density scenarios. The results show that MCIR achieves a shorter end-to-end delay and a higher packet delivery ratio in urban VANET communications.

In intelligent transportation systems, the collaboration between vehicles and the road side units is essential to bring these systems to realization. The emerging Vehicular Ad Hoc Network (VANET) is becoming more and more important as it provides intelligent transportation application, comfort, safety, entertainment for people in vehicles. In order to provide stable routes and to get good performance in VANET, there is a need of proper routing protocols must be designed. In this paper, we are working with the very well-known ad-hoc on-demand distance vector (AODV) routing protocol. The existing Routing protocol AODV-L which is based on the Link expiration time is extended to propose a more reliable AODV-AD which is based on multichannel MAC protocol. For the performance evaluation of routing protocols, a simulation tool ‘NS2’ has been used. Simulation results show that the proposed AODV-AD protocol can achieves better performances in forms of high Route stability, Packet Delivery ratio and packet loss rate than traditional AODV-L and traditional AODV.

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.

Research on vehicular ad hoc networks (VANETs) has focused primarily on efficient routing protocol design under conditions where there are relatively large numbers of closely spaced vehicles, typical of major highways and urban areas. These routing protocols are designed principally for fully connected networks and are not suitable for packet delivery in a sparse, partially connected VANET. In rural areas, vehicle densities are low and roadway communication infrastructure is scarce, leading to long periods where vehicle-to-vehicle or vehicleto- roadside communications is infrequent, interrupted, or simply not possible. These attributes characterize a sparse VANET, and are characteristic of delay tolerant networks (DTNs). In this paper, we examine the challenges of VANETs in sparse network conditions, review alternatives including epidemic routing and propose a Border node Based Routing (BBR) protocol for partially connected VANETs. Unlike many VANET protocols that assume location awareness or mobility patterns to aid in routing decisions, BBR is designed to function in domains where location and mobility information is not available, as is typical in rugged terrain conditions. The BBR protocol can tolerate network partition due to low node density and high node mobility. The performance of this protocol is evaluated in OPNET TM with a Random Waypoint mobility model and a Geographic and Traffic Information (GTI) based mobility model that captures typical highway conditions. The simulation results are compared with those obtained using the Dynamic Source Routing (DSR) protocol and with an epidemic routing protocol. The simulation results show that BBR performs well for partially connected VANETs where other protocols fail and provides the advantage of not relying on a location service required by other protocols proposed for VANETs.

Several medium access control protocols have been proposed in the recent past for vehicles for accessing radio channels and for distributing timely active safety messages for inter-vehicle communication in Vehicular Ad hoc Networks (VANETs). As contention period is high in Medium Access Control (MAC) for channel access, MAC is unable to distribute timely safety messages. To reduce the contention period, Region based Clustering Mechanism (RCM) is applied with MAC protocols. RCM caters to the reduction of contention because the number of vehicles for each cluster is limited. In addition, it resolves the competition among vehicles to access radio channels for inter-vehicle communication. Ad Hoc On-Demand Distance Vector (AODV) routing protocol is used for providing shortest path between source and destination which increases the amount of packet reception and cluster formation. Geo cache is included in VANET in order to retain directory that includes information about nodes that have left a particular cluster through neighboring nodes.

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.

Past few decades have witnessed large increase in number of vehicles on roads due to which the traffic safety needs have also become complex and hence necessary to be taken care of. Vehicular ad hoc networks (VANETs) are becoming an asset for achieving all these goals. VANETs provide applications like driver assistance, passenger comfort and vehicle safety. Apart from its general characteristics due to the dynamic nature of road environments and traffic patterns, communication linkage among vehicles in VANETs suffers breakage problem hence requires a very reliable routing protocol. To manage the communication efficiently many routing protocols are already available for MANETs which can be further used for routing and communication among vehicles in VANETs, but characteristics of these two networks (VANET and MANET) are very different, so there is requirement to enhance these MANET routing protocols so that those can be used in VANETs. When we use some existing routing protocols in VANET then number of link breakage are surprisingly high because mobility is higher in VANETs as compared to MANETs. So this paper presents advanced version of an existing MANET routing protocol for better performance in VANET environment. The new routing protocol has removed problem of large number of routing error messages which was existing in AODV routing protocol. Protocol proposed in this paper has better results as compared to AODV and paper has also shown results of simulation and also elaborated the findings.

<h2>Abstract</h2> <p><strong>Objective:</strong> The objective of this work is to enhance Adhoc On-demand Distance Vector (AODV) routing protocol for better communication through reliable routing scheme.<strong> Methods:</strong> In this paper, a reliable path selection algorithm is proposed to find the Most Reliable Path (MRP) between the source and destination vehicles. Reliable Path Ad-hoc On demand Distance Vector (RPAODV) is proposed for efficient route discovery in Vehicular Ad-hoc Network (VANET). The algorithm divide network into manageable group and it maintains Cluster Member (CM) updates handling, Cluster Head (CH) re-selection, Cluster merging. The efficient routing decisions would lead to better communication in VANET. It is made by assigning dynamic and static information appropriately to the variables in process. The dataset used is both static and dynamic which is efficient in when compared with existing protocols. <strong>Findings:</strong> The finding of most reliable path in the network of VANET is carried out by the proposed reliable path selection algorithm. The algorithm divides the network as various parts that comprise the information of clustering. The clustering is the mechanism of grouping of nodes into clusters. Clusters possess members and head. The cluster head would be the point of initiation of communication and any node can be re-selected as cluster head. The members of clusters would be updated as per changes in clustering mechanism. The uniqueness of the proposed algorithm revealed through easy identification of vehicles to form a cluster, cluster members maintenance, and fast data communication over the network. The proposed RPAODV adds the extra fields for RouteREQuest (RREQ) and RouteREPly (RREP) messages (CH and CM information). It also works out for static and dynamic topology in good manner by the implementation of modified AODV algorithm. The scalability is also taken care by enhancing topology variant. The performance of the algorithm is measured and analyzed with the existing protocols and posted in graphs. <strong>Novelty:</strong> The simulation results show that the proposed work outperforms 60% than the existing schemes works Cluster-based VANET-oriented Evolving Graph( CVoEG), Leapfrog-Anti-Colony Optimization(LP-ACO) in terms of route reliability (0.11s high), packet delivery ratio (20% high), end to end delay (0.5 saverage), and throughput (10 kbps high).</p> <p><strong>Keywords:</strong> VANET; Routing Protocol; RPAODV; Clustering; Reliable Routing; and Cluster message</p>

Vehicular Ad Hoc Network (VANET) is the ad hoc wireless technology which uses vehicle nodes connected with each other’s to form a network. The basic function of this network is providing a connection between vehicles to enable the transmission of data. Security is an important issue that must be provided by VANETs. Moreover, one of the most challenges of this network is their vulnerability of security since it has a large number with high speed of vehicles which may lead it to lay under different types of security attacks. Attacks of the network layer can be classified based on routing operation phase. One of the most widely used routing protocols is Ad Hoc on Demands Distance Vector (AODV). AODV is a reactive routing protocol, which is established to make connection between nodes only as required. This research aims to eliminate the effect of attacks and improve the performance of AODV in VANET. Three types of network layer attacks were used to examine their effect on VANET (blackhole, flooding, and rushing attacks). In addition to proposing the combination of more than one type of routing attacks at the same time to show their effect on AODV in VANET, we also proposed the use of AntNet algorithm to eliminate the effect of attacks. The simulation results show that the blackhole attack has a higher effect on AODV compared with the flooding and rushing attacks. The proposed combination of attacks on network showed a high damage on its performance compared with using individual network attacks on AODV in VANET. Simulation results also show various AntNet algorithm efficiencies in the improvement of VANET performance under network attacks. They show in this research that the AntNet has higher efficiency in reducing blackhole attack effect with 29.83%, then, with rushing attack, the percentage of enhancement is 16.82%, and with flooding attack, AntNet has the lowest enhancement efficiency with value of 9.04%.

Ad Hoc Routing with Distributed Ordered Sequences

Background/Objectives: Routing protocols play an important role in the performances of Vehicular Ad Hoc networks (VANET). Routing protocols procedures are controlled with a set of parameters from being dragged to undesired situations such as flooding the network with unnecessary overhead. These parameters have a direct impact on the efficiency of a routing protocol and the overall network performances. The impacts of these parameters on the network performances are less considered in the literature. Methods: This paper proposed the Taguchi delta analysis to measure the impact of Greedy Perimeter Stateless Routing (GPSR) protocols parameters on the performances of VANET. Then, the obtained results are investigated with iterative method to validate the Taguchi observations. Further, an offline optimization of the GPSR parameters is evaluated by performing Taguchi SNR method for fine-tuning the GPSR routing parameters. Application/ Improvements: GPSR with Taguchi tuned is compared with GPSR configuration in a realistic VANET scenario. The obtained results showed that, GPSR with Taguchi configuration outperformed the GPSR in terms of delay and PDR on the simulated scenarios. Keywords: GPSR, Optimization, Routing Parameters, Taguchi Method, VANET

This paper presents a novel position-based routing protocol for vehicular ad hoc networks (VANETs) to enhance traffic safety and traffic organization and facilitate driving through a smart transportation system. The protocol is referred to as the traffic flow-oriented routing (TFOR) protocol for VANETs. It considers a real-time urban scenario with multi-lane and bi-directional roads. It chooses junction optimally considering vehicular traffic flows to accomplish robust routing paths and thereby forwarding the data packets. The new junction selection mechanism and routing between the junctions is based on two-hop neighbor information, which increases packet-delivery ratio and decreases end-to-end delay. We designed, implemented, and compared TFOR against existing routing protocols of VANETs (greedy-perimeter stateless routing (GPSR), geographic source routing (GSR), and enhanced greedy traffic-aware routing (E-GyTAR)). Simulation outcomes in urban scenarios show that TFOR minimizes average end-to-end delay and routing overhead by on average 15.3% and 19.5%, respectively, compared to GPSR. It reduces routing overhead up to 17% compared to GSR. TFOR maximizes packet-delivery ratio on an average of 17.5%, 10.7%, and 7.2% compared to GPSR, GSR, and E-GyTAR, respectively.

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.

The appropriate design of a vehicular ad hoc network (VANET) has become a pivotal way to build an efficient smart transportation system, which enables various applications associated with traffic safety and highly-efficient transportation. VANETs are vulnerable to the threat of malicious nodes stemming from its dynamicity and infrastructure-less nature and causing performance degradation. Recently, software-defined networking (SDN) has provided a feasible way to manage VANETs dynamically. In this article, we propose a novel software-defined trust based VANET architecture (SD-TDQL) in which the centralized SDN controller is served as a learning agent to get the optimal communication link policy using a deep <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q$ </tex-math></inline-formula> -learning approach. The trust of each vehicle and the reverse delivery ratio are considered in a joint optimization problem, which is modeled as a Markov decision process with state space, action space, and reward function. Specifically, we use the expected transmission count ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$ETX$ </tex-math></inline-formula> ) as a metric to evaluate the quality of the communication link for the connected vehicles’ communication. Moreover, we design a trust model to avoid the bad influence of malicious vehicles. Simulation results prove that the proposed SD-TDQL framework enhances the link quality.

Today IoT integrate thousands of inter networks and sensing devices e.g., vehicular networks, which are considered to be challenging due to its high speed and network dynamics. The goal of future vehicular networks is to improve road safety, promote commercial or infotainment products and to reduce the traffic accidents. All these applications are based on the information exchange among nodes, so not only reliable data delivery but also the authenticity and credibility of the data itself are prerequisite. To cope with the aforementioned problem, trust management come up as promising candidate to conduct node’s transaction and interaction management, which requires distributed mobile nodes cooperation for achieving design goals. In this paper, we propose a trust-based routing protocol i.e., 3VSR (Three Valued Secure Routing), which extends the widely used AODV (Ad hoc On-demand Distance Vector) routing protocol and employs the idea of Sensing Logic-based trust model to enhance the security solution of VANET (Vehicular Ad-Hoc Network). The existing routing protocol are mostly based on key or signature-based schemes, which off course increases computation overhead. In our proposed 3VSR, trust among entities is updated frequently by means of opinion derived from sensing logic due to vehicles random topologies. In 3VSR the theoretical capabilities are based on Dirichlet distribution by considering prior and posterior uncertainty of the said event. Also by using trust recommendation message exchange, nodes are able to reduce computation and routing overhead. The simulated results shows that the proposed scheme is secure and practical.