Efficient vehicular ad‐hoc networks routing based on junctions

Due to many challenging issues in vehicular ad-hoc networks (VANETs), such as high mobility and network instability, this has led to insecurity and vulnerability to attacks. Due to dynamic network topology changes and frequent network re-configuration, security is a major target in VANET research domains. VANETs have gained significant attention in the current wireless network scenario, due to their exclusive characteristics which are different from other wireless networks such as rapid link failure and high vehicle mobility. In this are, the authors present a Secured and Safety Protocol for VANET (STVAN), as an intelligent Ad-Hoc On Demand Distance Vector (AODV)-based routing mechanism that prevents the Denial of Service attack (DoS) and improves the quality of service for secured communications in a VANET. In order to build a STVAN, the authors have considered a smart traffic environment in a smart city and introduced the concept of load balancing over VANET vehicles in a best effort manner. Simulation results reveal that the proposed STVAN accomplishes enhanced performance when compared with other similar protocols in terms of reduced delay, better packet delivery ratio, reasonable energy efficiency, increased network throughput and decreased data drop compared to other similar approach.

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.

VANET (Vehicular Ad Hoc Network) is a significant term in ITS (intelligent transportation systems). VANETs are also mentioned as ITN (intelligent transportation Networks), which are used to enhance road safety in growing technology. The connectivity of nodes is a challenging one because of its high mobility and the sparse network connectivity must be handled properly during its initial deployment of a VANET for avoiding accidents. Quality of service (QoS) in VANET becomes a significant term because of its increasing dare about unique features, like poor link quality, high mobility, and inadequate transporting distance. Routing is the foremost issue in the wireless ad hoc network, which is used to transmit data packets significantly. This paper provides a crucial review of the classification of existing QoS routing protocols, cross-layer design approach and classification, and various performance parameters used in QoS routing protocols. The corresponding cross-layer protocols are overviewed, followed by the major techniques in cross-layer protocol design. Moreover, VANET is presented with many exclusive networking research challenges in precise areas such as security, QoS, mobility, effective channel utilization, and scalability. Finally, the paper concluded by various comparison discussion, issues, and challenges of several routing protocols for VANET. No. of publications over the period from 2010 to 2019 in various scientific sources also showed in this review. This survey provided the technical direction for researchers on routing protocols for VANET using QoS.

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.

Kinetic mobility management applied to vehicular ad hoc network protocols

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.

Intelligent Transportation Systems (ITS) is an integrated approach being developed to exchange relevant information to increase the safety and efficiency of the road transportation systems. Vehicular Ad hoc Network (VANET), a variant of mobile ad hoc networks (MANET), is a core component of ITS. Performance of this smart ITS mainly owes to the design of efficient routing protocols in VANETs. Distinct features of VANETs like unsteady connectivity, high mobility and partitioning of the network have made routing of the information in VANETs difficult and challenging, hence dictating the development of efficient routing protocols. The computation of the best route measures the performance of communication whereas routing protocols takes care of communication & routing of the data. Provision of smart communication, necessitates the analysis of routing protocols in VANET. Accordingly in this paper we have reviewed various types of existing routing protocols in VANET, listing their advantages and disadvantages. Lastly possible inclinations of forthcoming research linked to VANET routing are discussed.

Vehicular ad hoc networks (VANETs) present an intriguing platform for several applications on e.g., intelligent transportation system (ITS) and infotainment applications aspire to be the main pattern of communication among vehicles while travelling. This can significantly impact on the amount of data exchanged by vehicles, increasing the contention on communication links and thus, degrading the quality of service of these applications. So, discrimination of data becomes imperative and forwarding critical information on suitable routes becomes decisive. Hence, a quality of service (QoS)-driven mechanism is needed to handle and assign network resources according to the stringent application data traffic demands. But, VANETs high node mobility and frequent link failure, stuck a big challenge in implementing an effective policy to meet and enforce these QoS requirements. A promising way to tackle this issue is to enforce QoS at the network layer, since it is the crucial point in VANETs’ communication. So, over the years, many QoS-aware routing protocols were specifically conceived for VANETs. In this paper, we present a comprehensive survey of QoS-aware routing protocols in VANETs’ literature. We examined the protocols based on their ability to support ITS infotainment services, their multi-constraint path problem (MCP), protocol’s functionality and weakness, objectives and design challenges. This way, we outline future directions for VANETs QoS-aware protocol research.

Rapid and tremendous advances in wireless technology, miniaturization, and Internet of things (IoT) technology have brought significant development to vehicular ad hoc networks (VANETs). VANETs and IoT together play a vital role in the current intelligent transport system (ITS). However, a VANET is highly vulnerable to various security attacks due to its highly dynamic, decentralized, open-access medium, and protocol-design-related concerns. Regarding security concerns, a black hole attack (BHA) is one such threat in which the control or data packets are dropped by the malicious vehicle, converting a safe path/link into a compromised one. Dropping data packets has a severe impact on a VANET’s performance and security and may cause road fatalities, accidents, and traffic jams. In this study, a novel solution called detection and prevention of a BHA (DPBHA) is proposed to secure and improve the overall security and performance of the VANETs by detecting BHA at an early stage of the route discovery process. The proposed solution is based on calculating a dynamic threshold value and generating a forged route request (RREQ) packet. The solution is implemented and evaluated in the NS-2 simulator and its performance and efficacy are compared with the benchmark schemes. The results showed that the proposed DPBHA outperformed the benchmark schemes in terms of increasing the packet delivery ratio (PDR) by 3.0%, increasing throughput by 6.15%, reducing the routing overhead by 3.69%, decreasing the end-to-end delay by 6.13%, and achieving a maximum detection rate of 94.66%.

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.

Intervehicle communication gives vehicles opportunities to exchange packets within the limited radio range and self-organized in Ad Hoc manner into VANETs (Vehicular Ad Hoc Networks). However, due to issues such as the high mobility, insufficient market penetration ratio, and lacking of roadside units, connectivity is actually a big problem in VANETs. In addition, relying only on the direct connectivity in most of the previous works, say broadcasting which provides one-hop connections between nodes is far from the continuously growing application demands in VANETs, such as inter-vehicle entertainments, cooperative collision avoidances, and inter-vehicle emergency notifications. Therefore, the indirect connectivity from multihop forwarding is also a necessary complement especially for the case where direct connection is hardly achieved. In this paper, we define a new metric, that is, available connectivity, to consider both direct and indirect connectivity. After analyzing the statistical properties of direct and indirect connectivity in vehicular environment, the available connectivity is proposed and quantified for practical usage. Numerical results show that our available connectivity could provide correct and useful references for protocols design and performance improvements of different applications.

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.

With the rising interest of expedient, safe, and high-efficient transportation, vehicular ad hoc networks (VANETs) have turned into a critical technology in smart transportation systems. Because of the high mobility of nodes, VANETs are vulnerable to security attacks. In this paper, we propose a novel framework of software-defined VANETs with trust management. Specifically, we separate the forwarding plane in VANETs from the control plane, which is responsible for the control functionality, such as routing protocols and trust management in VANETs. Using the on-demand distance vector routing (TAODV) protocol as an example, we present a routing protocol named software-defined trust based ad hoc on-demand distance vector routing (SD-TAODV). Simulation results are presented to show the effectiveness of the proposed software-defined VANETs with trust management.

Vehicular Ad hoc Network (VANET) is a very promising approach that aims to improve vehicle and road safety, traffic efficiency, as well as comfortability to both drivers and passengers. Different types of applications were implemented to achieve these goals. Some of these applications require the exchanging of multiple and ordered messages as well as the existence of a stable Internet connection. However, the high node mobility of VANET seems to be one of the main stumbling blocks for adopting such applications. In this paper, we have investigated through a real experiment, how the VANET mobility imposes challenges in establishing and maintaining a long-lasting connection. In addition, we have proposed a mechanism to improve the communication efficiency over VANETs. Our solution is based on the concept of intelligent proxies that can be sent from, say, one Roadside Unit to a vehicle so that the negotiation between them can be delegated to the proxy and take place locally. Using the proxy will reduce the number of exchanged network messages among vehicles and infrastructure, overcome the intermittent and short-lived connectivity challenge of the high mobility vehicular network and, consequently, increase the communication efficacy. Also, we have presented a framework that allows such proxies to operate safely and securely.

Emerging as the effective strategy of intelligent transportation system (ITS), vehicular ad hoc networks (VANETs) have the capacity of drastically improving the driving experience and road safety. In typical VANET scenarios, high mobility and volatility of vehicles result in dynamic topology of vehicular networks. That is, individual vehicle may pass through the effective domain of multiple neighboring road-side-units (RSUs) during a comparatively short time interval. Hence, efficient and low-latency cross-domain verification with all the successive RSUs is of significance. Recently, a lot of research on VANET authentication and key distribution was presented, while the critical cross-domain authentication (CDA) issue has not been properly addressed. Particularly, the existing CDA solutions mainly reply on the acquired confidential keying information from the neighboring entities (RSUs and vehicles), while too much trustworthiness is granted to the involved RSUs. Please note that the RSUs are distributively located and may be compromised or disabled by adversary, thus vital vehicle information may be revealed. Furthermore, frequent data interactions between RSUs and cloud server are always the major requisite so as to achieve mutual authentication with cross-domain vehicles, which leads to heavy bandwidth consumption and high latency. In this paper, we address the above VANET cross-domain authentication issue under the novel RSU edge networks assumption. Please note that RSUs are assumed to be semi-trustworthy entity in our design, where critical vehicular keying messages remain secrecy. Homomorphic encryption design is applied for all involved RSUs and vehicles. In this way, successive RSUs could efficiently verify the cross-domain vehicle with the transited certificate from the neighbor RSUs and vehicle itself, while the identity and secrets of each vehicle is hidden all the time. Afterwards, dynamic updating towards the anonymous vehicle identity is conducted upon validation, where conditional privacy preserving is available. Moreover, pairing-free mutual authentication method is used for efficiency consideration. Formal security analysis is given, proving that the HCDA mechanism yields desirable security properties on VANET cross domain authentication issue. Performance discussions demonstrate efficiency of the proposed HCDA scheme compared with the state-of-the-art.