VANET Topology Research Articles

Position-Based Multipath Route Switching Protocol for Intelligent VANETs Using Wiedemann Car-Following Model

The high dynamicity in VANET topology increases the possibility of frequently broken links and degraded the type of service provided to its customers (i.e., comfort and safety services) that may lead into a catastrophe. In this paper, a Quality-of-Service (QoS)-aware position-based multipath route switching protocol for VANETs-based intelligent transportation systems is proposed. The proposed protocol adopts one of three main route switching criteria: Least Connection Delay (LDD), least number of path-switching (LPS), and the least number of path-switching with the minimum delay (LPSMD). The proposed protocol finds multiple paths between the source and the destination and predicts the future connectivity of each path using the Wiedemann Car-Following Model (Wiedemann and Reiter-99). According to the requested QoS and the route switching criterion adopted, the route switching protocol dynamically switches between the pre-defined multiple paths such that the Network Performance Metrics (NPMs) are guaranteed for the entire VANET. Using different network parameters such as vehicular node density, vehicular node speed, and the time-period for collecting vehicle information, extensive simulation results show that the proposed LDD-based route switching protocol outperforms the other route switching criteria in guaranteeing the studied NPMs (i.e., 1) Packet delivery ratio with a 3.6% enhancement over LPSMD and 8.6% enhancement over LPS; 2) Average end-to-end total packet delay with a 4.2% enhancement over LPSMD and 3.4% enhancement over LPS).

Route Optimization using Hybrid GRU Learning Model for SDN and Edge-Based VANET Topology

Route Optimization using Hybrid GRU Learning Model for SDN and Edge-Based VANET Topology

New Gateway Selection Algorithm Based on Multi-Objective Integer Programming and Reinforcement Learning

Connecting vehicles to the infrastructure and benefiting from the services provided by the network is one of the main objectives to increase safety and provide well-being for passengers. Providing such services requires finding suitable gateways to connect the source vehicles to the infrastructure. The major feature of using gateways is to decrease the load of the network infrastructure resources so that each gateway is responsible for a group of vehicles. Unfortunately, the implementation of this goal is facing many challenges, including the highly dynamic topology of VANETs, which causes network instability, and the deployment of applications with high bandwidth demand that can cause network congestion, particularly in urban areas with a high-density vehicle. This work introduces a novel gateway selection algorithm for vehicular networks in urban areas, consisting of two phases. The first phase identifies the best gateways among the deployed vehicles using multi-objective integer programming. While in the second phase, reinforcement learning is employed to select a suitable gateway for any vehicular node in need to access the VANET infrastructure. The proposed model is evaluated and compared to other existing solutions. The obtained results show the efficiency of the proposed system in identifying and selecting the gateways.

Гибридная модель эффективного представления данных в беспроводных транспортных сетях с динамической топологией VANET

At the moment, traffic information systems require the aggregation of big data to provide recommendations to vehicles in the current conditions, which leads to an increase in user comfort. The main tool for improving the level of safety was timely informing traffic participants about the current situation on the road, weather conditions, etc. In this case, if the network object is subjected to an attack and the data is replaced during transmission, then the disclosure of confidential information, the creation of emergency si¬tuations, etc. is possible throughout the visibility zone of the VANET segment. In this regard, the most urgent issue is ensuring security, including when transmitting traffic, and conducting an additional analysis of big data about anomalies and ongoing unauthorized actions. Aim. To develop a hybrid model for the efficient placement of source and intermediate data in wireless transport networks with a dynamic VANET topology, which represents a structural representation of a software-configurable network and edge computing tools, with the ability to optimally analyze data from network nodes and identify anomalies. Methods. The considered Edge computing approach consists in locating computing capacities in geogra¬phically distributed computing devices closer to end users. Software-configurable SDN networks transfer part of the control and physical transmission functions from routing and switches, reducing the load. Within the framework of this study, an RD algorithm has been developed – a protocol for transmitting and processing intermediate data. To carry out clustering of vehicles on a network segment, the DBSCAN unsupervised learning method was used. Preliminary analysis of abnormal traffic was carried out on the basis of RNN neural network models with short-term memory. Results. The developed hybrid model of efficient placement of initial and intermediate data makes it possible to react faster to unauthorized actions. Conclusion. The results obtained in the course of the study confirm the need to implement and scale a hybrid model with boundary calculations in practice.

Geographic routing enhancement for urban VANETs using link dynamic behavior: A cross layer approach

Geographic routing protocols are suitable for VANETs because of their scalability and low overhead. However, the optimal selection of next-hop forwarding nodes is challenged by the dynamic topology of VANETs, in addition to the variable quality of wireless links and the temporal changes in available bandwidth. In this paper, we introduce a scheme to select the next-hop forwarder based on its mobility relative to the destination and the dynamic behavior of its link with the current forwarder. We present a cross-layer model of link dynamic behavior (LDB), which takes into account the loss ratio, physical interference, and medium access control (MAC) overhead, including queuing and retransmission delays experienced on a wireless link. Based on LDB, we propose an enhancement of geographic routing, called Geo-CAP, for urban VANETs. By selecting more reliable links and timely reacting to varying nodes load and network conditions, the proposed protocol can offer considerable performance gains by reducing packet loss and delay. This performance is demonstrated using extensive simulation experiments in NS-3.

The Delay-Constrained and Network-Situation-Aware V2V2I VANET Data Offloading Based on the Multi-Access Edge Computing (MEC) Architecture

This paper proposes a Multi-access Edge Computing (MEC)-based delay-constrained k-hop-limited VANET data offloading method. In the proposed method, a vehicle X can launch the vehicle-to-vehicle-to-infrastructure (V2V2I) VANET data offload from the cellular network to the IEEE 802.11p/802.11bd Road Side Unit (RSU) when (i) X is not in the corresponding RSU's signal coverage and (ii) there is a multiple-hop vehicle-to-vehicle (V2V) path connecting X with a vehicle Y that is inside the RSU's signal coverage. The MEC paradigm is used to check whether a k-hop-limited V2V2I offloading path exists for vehicle X or not based on the periodically reported contexts from vehicles. In addition to use the V2V2I path's lifetime and quality to derive the suitable V2V2I offloading paths using the snapshot VANET topology on the time point of receiving X's reported context, this work proposed a scheme to derive the potential V2V2I paths that may exist in the future, i.e., in a constrained time interval, to find the better V2V2I offloading path. The performance evaluation shown that the proposed method outperforms the one that (i) only considers the data offloading path's lifetime or (ii) does not consider the candidate V2V2I offloading paths existed in the future.

A efficient and reliable communication to reduce broadcast storms in VANET protocol

Vehicular Ad Hoc Networks are the networks of the vehicles which are connected with the high dynamic topology which changing environment. In this VANET topology, the broadcasting the message is the simplest way for communication. This simplest way of communication will be used for transmission of emergency messages from vehicles to vehicles. But the method of message transmission leads to the unwanted data flooding which causes the broadcast storm problems in which affects the overall reliability and performance of the VANET networks. To eradicate this problem we propose the new algorithm called GHN works on the selective distance allocation methodology for data transmission. The outcome of the system proves to be more efficient in terms of data throughput packet delivery ratio and it has been simulated using NS2.

Cluster-based routing protocol using traffic information

In recent years, VANET has gained much attention from researchers and the different actors in the field of transport, because of its crucial role in intervehicular communication and road safety. However, VANET still faces many challenges in terms of implementation. Furthermore, the routing in VANET is the most critical issue, because of its major role in the communication between vehicles. So the routing strategy must consider the periodic change in the topology and other characteristics of VANET. Moreover, the method adopted in the routing must provide the best flow of data in view of various performance metrics. In this paper, we propose a cluster-based routing protocol using the road traffic information to ensure the packet transmission in the most reliable manner and in record time. The proposal routing protocol is simulated in city environment, and the experimental result show that our protocol is very effective.

Software Defined Architecture for VANET: A Testbed Implementation with Wireless Access Management

Toward ITS, academia and industry aim to utilize all possible radio access technologies in order to support reliable services and applications in VANETs. Thus, the inclusion of already deployed Wi-Fi networks in VANET topology is a crucial step for the next generation vehicular networks. However, the VANET topology also requires preservation of the features already offered by DSRC and the core cellular network. As a result, the coexistence of multiple different access technologies results in high complexity in terms of the control and management of the network infrastructure. To this end, software defined networking provides a promising opportunity to simplify the management and control of clumsy network infrastructures by decoupling the data and control planes in order to provide elasticity for current networks. In this article, we propose an architectural model that exploits this opportunity in order to enhance VANET with Wi-Fi access capability. Moreover, we offer a novel software defined VANET architecture that consists of soft OpenFlow switches with Wi-Fi capabilities as both roadside units and vehicles. In particular, we first investigate existing test tools and environments for software defined wireless networks and also supply a novel testbed architecture in order to provide a feasible test environment for evaluating the proposed architecture. Additionally, we propose a Wireless Access Management (WAM) protocol that provides wireless host management and basic flow admission with respect to the available bandwidth to validate the capability of the offered architecture. The observation results of the deployed testbed prove the conformity of the offered 802.11 architecture to the VANET.

Trajectory-Based Hierarchical Adaptive Forwarding in Vehicular Ad Hoc Networks

This paper proposes a Trajectory-Based Hierarchical Adaptive Forwarding (THAF) scheme, tailored and optimized for the efficient multihop vehicle-to-vehicle (v2v) data delivery in vehicular ad hoc networks. We utilize the trajectories of vehicles provided by GPS-based navigation systems to predict forward delay and access area in a privacy-preserving manner. Different from existing trajectory-based forwarding schemes, we establish a hierarchical VANET topology to optimize forwarding path and adopt adaptive diffusion strategy to forward data in light-traffic situations. Through theoretical analysis and extensive simulation, it is shown that our design performs better than the existing schemes.

Adaptive Control Channel Interval in VANET Based on Mobility Model and Queuing Network Analysis

The dynamic of changing network topology and vehicle density in VANET are causing the dynamic of message traffic intensity. This situation requires adaptability of channel management to provide the channel capacity dynamically and proportionally. The length of CCH interval in VANET represents the capacity of channel or service rate of vehicles. The fixed pattern of CCH/SCH interval as published by IEEE 802.11p/1609.4 would become the constraint of adaptability of vehicles in VANETs. Moreover it would affect to VANET performance inefficient. This research proposes an adaptive scheme of CCH/SCH interval which proportional with density of vehicles based on the number of vehicle connected each other’s. To show how effective the proposed adaptive scheme of CCH/SCH interval can afford to improve of VANET performance (compared to fixed interval scheme of current IEEE standard), we analyze by combining mobility model and queuing network model. We assume that statistically there is a steady state of VANET topology which can be analyzed by using queuing network model. We specified the real map of highway in Bandung city along 10 Km length to achieve the representative experimental result. The various specified of speeds are: 70-90 Km/h, 90-110 Km/h, and 110-130Km/h, while the various of density of vehicle are 15, 30, 45, 60, 75, and 90 vehicles along 10Km length of highway. All of experiments performed in two main scenarios, i.e. the fixed CCH/SCH interval, and adaptive CCH/SCH interval which compared each other to see the improvement. The analytical result examined by simulation method. The experimental results show the improvement of adaptive CCH/SCH interval. The improvement of average delay is 10ms, and the improvement of system throughput is 450 kbps.

DV-CAST: A distributed vehicular broadcast protocol for vehicular ad hoc networks

The potential of infrastructureless vehicular ad hoc networks for providing safety and nonsafety applications is quite significant. The topology of VANETs in urban, suburban, and rural areas can exhibit fully connected, fully disconnected, or sparsely connected behavior, depending on the time of day or the market penetration rate of wireless communication devices. In this article we focus on highway scenarios, and present the design and implementation of a new distributed vehicular multihop broadcast protocol, that can operate in all traffic regimes, including extreme scenarios such as dense and sparse traffic regimes. DV-CAST is a distributed broadcast protocol that relies only on local topology information for handling broadcast messages in VANETs. It is shown that the performance of the proposed DV-CAST protocol in terms of reliability, efficiency, and scalability is excellent.