Topology Of Vehicular Ad Hoc Networks Research Articles

Vehicular Ad Hoc Networks Topology Optimization for Autonomous Intersection Management System: A Periodic Intervention-Based Approach

Vehicular Ad Hoc Networks Topology Optimization for Autonomous Intersection Management System: A Periodic Intervention-Based Approach

Applying Graph Neural Networks to Support Decision Making on Collective Intelligent Transportation Systems

Recent advancements in autonomous vehicles and vehicular ad-hoc networks (VANETs) have presented diverse solutions for vehicle safety and automation. The demand to establish a connection between the two worlds has increased significantly to augment road safety and provide benefits to end users. Intelligent Transportation Systems (ITSs) vehicle station leaves a signed trace of its geographic location that is rated as personal data. An attacker can misuse existing V2V communication to track a vehicle’s CAM-trace and to avoid misusing CAMs to harm privacy, selectives communication approaches for CAMs should be chosen instead of continuous communication of current CAMs. In this article we propose a VANET topology learning methodology prioritizing anonymization that can use any existing Graph Learning framework. Further, this work enhances the quality of graph models applied to the context of VANETs and autonomous vehicles. With the real coordinates, establishment of a grid of cells and the generation and training of the graph, we can compare different frameworks generally used in these issues and one can chose the one that fits better to each scenario.

Enhanced Ant Colony Optimization for Vehicular Ad Hoc Networks Using Fittest Node Clustering

Vehicular ad hoc networks (VANETs) are a rapidly evolving field at the intersection of intelligent transportation systems, emphasizing the need for a stable and scalable VANET topology to accommodate growing vehicular densities. The intricate challenge of route selection calls for advanced clustering protocols to bolster road safety and message routing. This research introduces a novel approach to intelligent clustering routing protocols, leveraging heuristic-based solutions built upon an enhanced ant colony optimizer (ACO) framework. The study unfolds in two stages: the creation of a dynamic search space model and the election of cluster heads (CHs). The innovative dynamic aware transmission range parallel Euclidean distance (DA-TRPED) technique establishes a dynamic search space using the parallel Euclidean distance (PED) concept. This approach evaluates vehicular nodes by estimating PED values, reducing the search process’s complexity. Subsequently, an intelligent cluster head is selected by enhancing the dynamic evaporation factor (DEF) within the ACO technique. The experimental validation of the DA-TRPED technique takes place in NS2 simulations, demonstrating superior performance compared to conventional ACO. This enhancement is evident in metrics such as packet delivery, packet drop, throughput, end-to-end delay, and the lifetime analysis of clustered nodes. The proposed approach holds promise for optimizing VANETs, enhancing their stability and scalability while promoting road safety and efficient message routing.

Clustering Algorithms and Comparisons in Vehicular Ad Hoc Networks

Vehicular Ad hoc Network (VANET) is a new era in the transmission of dynamic information across communities. Intelligent Transportation Systems is only one of the many applications for VANET (ITS). The topology of VANET is extremely dynamic, and connections are irregular. These features cause information transmission in the VANET to be unreliable. Vehicle clustering is a successful strategy to increase the network's scalability and connection dependability. Characteristics of the VANET have an impact on clustering performance as well. An extensive explanation of VANET clustering algorithms is given in this article. A complete evaluation of clustering in VANETs is provided based on the clustering procedure. Most methods examine the clustering process in terms of Cluster Head selection metrics, formation, and its maintenance. The clustering methods are contrasted based on factors such as stability, convergence, overhead, and latency. There is also discussion of some of the most typical issues and the solutions used. Also, a summary of the performance metrics used to assess clustering algorithms is provided.

TGRV: A trust-based geographic routing protocol for VANETs

Vehicular ad-hoc networks (VANETs) consist of highly mobile and self-organized nodes that wirelessly communicate with one another and transmit a variety of information, some of which may be critical information. Due to the rapidly changing topology of VANETs and the high-speed mobility of the participating vehicles, the routing of packets in these networks is a challenging task. Moreover, the presence of malicious vehicles in VANETs makes the correct routing of packets more challenging. In this paper, we propose a trust-based geographic routing protocol for VANETs (TGRV) that limits the participation of malicious vehicles in routing. In TGRV, to select the next-hop, a sender not only considers the distance, speed, and direction of its neighbors but also evaluates their direct trust and recommendation trust. For this purpose, TGRV uses a monitoring system that allows each vehicle to monitor the correct packet forwarding rate of its next-hop. In this way, the vehicle updates its direct trust to the next-hop and retransmits the packets if the packets are lost. The vehicle also sends its observations of the next-hop to its neighbors with a push-based notification, and based on that, the neighbors can update their recommendation trust about the next-hop. The monitoring system applies distance prediction in a modified promiscuous mode to better estimate the correct packet forwarding rate of the next-hop. To enhance the accuracy of trust management, the trust values of interactions are reduced over time by using a decay factor. TGRV uses the number and trust of two-hop neighbors, which helps in selecting the next-hop that is in a more trusted zone. Our extensive simulations on OMNeT++ show that when the percentage of malicious vehicles in an urban scenario increases from 0 to 25%, the packet delivery ratio of TGRV decreases from 95.1 to 88.7%, which performs very well compared to the GPSR and PGRP protocols. Also, the end-to-end delay of TGRV increases from 3.79 to 7.07 s and the average hop count of TGRV increases from 6.7 to 9.9, which are significant increases compared to the other two protocols. These increases are acceptable because, in the other two protocols, there is no monitoring and retransmission, and the probability of packet delivery failure on longer routes is higher. The cost and security analysis also show that the memory, communication, and computational overheads of TGRV are acceptable, and TGRV is resistant and resilient to some important trust-based attacks.

A Cross-Layer Approach MAC/NET with Updated-GA (MNUG-CLA)-Based Routing Protocol for VANET Network

Nowadays, technology is developed rapidly in communication technology. Several new technologies have been introduced due to the evolution of wireless communication and this provided the way to communicate among vehicles, using a Vehicular Ad-Hoc Network (VANETs). Routing in VANETs becomes most challenging because of the huge mobility and dynamical topology changes, which lead to reduced efficiency in the network. The core idea of this network is to increase the efficiency during the process of the communication. The most suited routing protocol for VANETs is Geographic routing, for the reason that it provides higher scalability and low overheads. The major challenges in VANETs are the selection of best neighbor in dynamically changing VANET topology. Furthermore, to provide better QoS needful actions are essential. In this paper, we introduced a new MAC/NET with Updated Genetic Algorithm—A Cross Layer Approach, (MNUG-CLA) based on a MAC layer and network layer to overcome the drawbacks of the network. In the network layer, a new neighbor discovery protocol is developed to select the best next hop for the dynamically varying network. In the MAC layer, in order to improve the quality, multi-channel MAC model is introduced for instantaneous transmission from various service channels. For overall optimal path selection, we used an updated GA algorithm. The performance was demonstrated through the use of an extensive simulation environment, NS-2. The simulation results prove that this protocol provides better results, in terms of energy efficiency, energy consumption and successive packet transmission, when compared with the earlier approaches.

An optimized location service for the fifth generation VANETs inspired by traffic lights.

Vehicular ad-hoc networks (VANETs) address a steadily expanding demand, particularly for public emergency applications. Real-time localization of destination vehicles is important for determining the route to deliver messages. Existing location administration services in VANETs are classified as flooding-based, flat-based, and geographic-based location services. Existing localization techniques suffer from network disconnection and overloading because of 5G VANET topology changes. 5G VANETs have low delay and support time-sensitive applications. A traffic light-inspired location service (TLILS) is proposed to manage localization inspired by traffic lights. The proposed optimized localization service uses roadside units (RSUs) as location servers. RSUs with the maximum traffic weight metrics were chosen. Traffic weight metrics are based on speed of vehicles, connection time and density of neighboring vehicles. The proposed TLILS outperforms both Name-ID Hybrid Routing (NIHR) and Zoom-Out Geographic Location Service (ZGLS) for packet delivery ratio (PDR) and delay. TLILSs guarantee the highest PDR (0.96) and the shortest end-to-end delay (0.001 s) over NIHR and ZGLS.

Topology characteristic analysis of vehicular ad hoc network based on time-varying complex network

The dynamic network topology of the Vehicular Ad Hoc Network (VANET) directly affects network performances. The VanetMobiSim software was used to study the dynamic topology of VANET in detail. A time-varying model of VANET was built. First, the information transmission model of VANET was established on the basis of the time-varying network theory. The evolution of VANET characteristic parameters in a time-varying process was stimulated by using the information transmission time τ and the maximum tolerated delay time δ accessibility graph. Then, we perform mathematical analysis of the relations of (τ, δ) to the out-degrees, average packet accessibility, and asymmetry ratio. Finally, the relations of the node communication radius to the global efficiency and the average harmonic mean of the distances were analyzed. The results indicated that the time-varying accessibility graph made VANET information transmission more efficient; reducing the information transmission time τ or increasing the maximum tolerated delay time δ tends to bring out the improving temporal connectivity of the whole network, thus improving the efficiency of packet transmission.

Payoff-based Dynamic Segment Replication and Graph Classification Method with Attribute Vectors Adapted to Urban VANET

Due to the number of constraints and the dynamic nature of vehicular ad hoc networks (VANET), effective video broadcasting always remains a difficult task. In this work, we proposed a quality of video visualization guarantee model based on a feedback loop and an efficient algorithm for segmenting and replicating video segments using the Payoff-based Dynamic Segment Replication Policy (P-DSR). In the urban VANET environment, P-DSR is defined by taking into account the position of the vehicles, the speed, the direction, the number of neighboring vehicles, and the reputation of each node to stabilize the urban VANET topology. However, the management of various load control parameters between the different components of the urban VANET network remains a problem to be studied. This work uses a multi-objective problem that takes the parameters of our algorithm based on the Graph Classification Method with Attribute Vectors (GCMAV) as input. This algorithm aims to provide an improved class lifetime, an improved video segment delivery rate, a reduced inter-class overload, and an optimization of a global criterion. A scalable algorithm is used to optimize the parameters of the GCMAV. The simulations were carried out using the NetSim simulator and Multi-Objective Evolutionary Algorithms framework to optimize parameters. Experiments were carried out with realistic maps of Open Street Maps and its results were compared with other algorithms such as Seamless and Authorized Multimedia Streaming and P-DSR. The survey suggests that the proposed methodology works well concerning the average lifetime of the inter-classes and the delivery rate of video segments.

Coordination Game Theory-Based Adaptive Topology Control for Hybrid VLC/RF VANET

In intelligent transportation systems, vehicular ad-hoc network (VANET) is an important technique for data exchange among vehicles and other mobile terminals (MTs) on the roads. In VANET, radio frequency (RF) and visible light communication (VLC) links could cooperate to improve the communication quality of MTs. However, in order to fully exploit the benefits of these two kinds of communication links and improve the VANET performance, a topology control (TC) scheme should be developed to help MTs establish VLC and RF links with their neighbors properly based on the distribution of MTs in the VANET. Since there is usually not a central controller in the VANET, the TC scheme should be conducted locally at each MT. As the size of VANET increases, distributed TC becomes more challenging since MTs usually need to make decisions with only local knowledge about the VANET. In addition, the frequent changes of VANET structure due to MT movements require that the TC scheme can adapt to the dynamic changes quickly. In consideration of those challenges, an adaptive TC scheme is proposed in this paper, aiming to achieve a balance between connectivity and power consumption for MTs in the hybrid VLC/RF VANET. In the proposed TC scheme, MTs can adjust their related links locally and iteratively based on merely its knowledge about the local VANET topology. Moreover, the TC problem is modelled by the coordination game, which guarantees that the proposed TC scheme can converge to a Nash Equilibrium state and can also adapt to the changes in VANET structure dynamically.

Performance Evaluation of AOMDV on Realistic and Efficient VANet Simulations

The digital transmission amongst vehicles and roadway equipment is necessary for the realization of smart transportation systems. Vehicular ad-hoc network (VANet) is an ascension field of engineering that presents brilliant transport applications, road safety, comfort and luxury to drivers. VANet protocols face many challenges because of the changing nature of vehicular ad-hoc network. VANet routing protocols perform a vital role in terms of the performance efficiency because they decide the mode of sending and receiving packets between mobile vehicular nodes. Finding suitable and efficient routing protocol is very important for the efficient implementation of VANet. The foremost objective of this research is to suggest the relevant and efficient VANet routing protocols in a high traffic density area. This research work presents a practical evaluation of the VANet topology’s features with respect to time for the high traffic situations. This evaluation incorporates the actual creation of roadway layout. An accurate traffic flow is produced by extracting run-time facts and figures from PeMS (Freeway Performance Measurement System) database and assigning this extracted information into a microscopic mobility model. To achieve our goal, we consider three routing protocols i.e., AOMDV, AODV and DSDV. The simulation results prove that the performance of AOMDV is greater in comparison to DSDV and AODV protocols in high traffic density areas. The AOMDV protocol improves overall network performance by achieving maximum throughput and minimum end to end delay.

IBMDA: Information based misbehavior detection algorithm for VANET

The safety event information sharing among the vehicles in motion is the primary goal to design the vehicular ad hoc network (VANET). The shared safety event information assists vehicles to avoid road accidents and driving inconvenience. The advantages of safety event information sharing in VANET has become blunt due to the misbehavior of vehicles. The vehicle’s misbehavior like dissemination of false information, reply of bogus messages, etc., can create traffic hazards on the road and may result in the loss of property and human lives. In VANET, the detection of such misbehaving vehicles along with minimum time delay in flooding safety event information (i.e., incident delay) to others is challenging due to the high speed of vehicles. The formation of stable VANET topology is a feasible solution among many to improve the performance of misbehavior detection and reducing incident delay even with high speed of vehicles. In this paper, we propose an information based misbehavior detection algorithm (IBMDA) that effectively works in stable cluster based VANET. Our proposed IBMDA algorithm that runs on the selected cluster head vehicles is used to verify the content of received safety event messages. The identification of vehicles as malicious or non malicious depends on the result of verification at cluster heads. An illustrative example is given to explore our proposed algorithm easily and effectively. The highway scenario is considered to test the performance of our proposed IBMDA algorithm. The simulation is performed with a detailed comparative analysis using ns-3 simulator. It is observed that under the considered scenario, our proposed algorithm improves the misbehavior detection accuracy up to 6.46% and reduces average incident delay approximately up to 14.78% as compared to existing algorithms.

QoS-aware multi-path video streaming for urban VANETs using ACO algorithm

Drivers can be provided with several beneficial services associated with video streaming in a vehicular ad-hoc network (VANET). Given the dynamic topology and high mobility of VANETs, a single path cannot support the required quality of service (QoS). To maximize global QoS metrics, a two-path model is proposed based on a disjoint algorithm to forward sub-streams over diverse paths from the transmitter to the receiver vehicle. In this solution, the video information spread in separate paths is categorized based on their priority. For this purpose, the protocol for transmitting each kind of video data should be selected cautiously. The present study aims to propose an ant colony optimization-based technique to establish the primary and secondary paths and enhance the QoS of routing paths. To achieve this goal, the QoS routing issue is formulated mathematically as a problem of constrained optimization. Moreover, to achieve high-quality video streaming, inter-frames are transmitted over the user datagram protocol and intra-frames are transmitted over the transmission control protocol (TCP). TCP transmission delays are also minimized using a TCP-ETX algorithm for selecting appropriate paths. According to the simulation results, the proposed two-path solution can be used to improve the quality of video streaming and to enhance the performance in terms of end-to-end delay, packet delivery ratio, and overhead. In this way, the proposed method can outperform several prominent routing algorithms such as adaptive QoS-based routing for VANETs, geographic source routing (GSR), intersection-based geographical routing protocol, and efficient GSR.

Complex Network Analysis of VANET Topology With Realistic Vehicular Traces

Recent years have witnessed growing interests in vehicular ad hoc network (VANET) topology. Existing works assume that the networks generated at each time are independent. In these works, the VANET topologies are formed based on simple traffic and communication models such as unit disk graph model. Interestingly, some works find that VANETs are scale-free ones characterized by strong connectivity and survivability, while some argue that they are not. This study analyzes VANETs in more realistic settings, trying to find the answer to the paradox. Specifically, in this paper we propose a Dynamically Evolving Networking (DEN) model and take as input realistic vehicular traces to make the research and results more practical. We consider the effect of node addition, node deletion and link loss due to node mobility and keep the network evolving by including preferential attachment and link compensation mechanisms. We find that the evolved VANET exhibits a scale-invariant feature under certain conditions. We also find that the emergence of such phenomenon has no relation to communication range if the range is large. Furthermore, we apply complex network theory to capture the dynamics of the VANET. Theoretically for the first time we show that VANET would evolve into the scale-free topology when the probability of node addition is relatively large or the probability of link compensation is properly set, the presence of which would help establish a strongly connected VANET topology.

Topology Control in Hybrid VLC/RF Vehicular Ad-Hoc Network

Vehicular ad-hoc network (VANET) is a promising technology to realize communications among vehicles in intelligent transportation systems. Conventional VANET utilizes radio frequency (RF) for vehicle to vehicle communications. However, as the vehicle density increases, RF-based VANET suffers from limited bandwidth and unavoidable interference. Visible light communication (VLC) is emerging as a complement candidate, which possesses the advantages of wide spectrum, high power efficiency and low interference, but also has the drawback of limited communication range. Therefore, the hybrid VLC/RF structure is beneficial to an efficient and reliable VANET. Since there are usually no center infrastructures in VANET and different vehicles could have different preferences, the distributed and non-cooperative topology control (TC) should be investigated for the establishment of VLC and RF links among various vehicles to satisfy some properties, e.g., interference level, power consumption, connectivity and delay requirements. Conventional TC schemes designed particularly for RF-based ad-hoc network can not be applied directly due to the distinctive features of VLC and RF links. In this paper, the TC problem for the hybrid VLC/RF VANET is modeled as a potential game. When considering the different features of the two kinds of links, a distributed TC algorithm is proposed to handle the TC game, in which the RF and VLC transmitting power of each vehicle is locally adapted based on the vehicle’s local knowledge about the VANET topology and can converge to a Nash Equilibrium state.

Partial backwards routing protocol for VANETs

The design and implementation of efficient routing protocols for highly dynamic networks such as Vehicular Ad hoc NETworks (VANETs) is a challenging task, due to the specific features of these networks such as rapid movements of nodes, frequent link disconnections and large scale networks. Efficient routing mechanisms need to adopt to the VANETs characteristics to achieve high routing performances. One alternative is the use of the traffic information in the routing process. In this paper, we propose a novel routing protocol called Partial Backwards Routing Protocol (PBRP), which consists of three integrated strategies: dissemination of road traffic information, partial forwarding algorithm and backwards recovery strategy working together to provide permanent and advanced information about vehicular traffic which widely helps the routing algorithm to stand up to dynamic changes of VANETs topology, and to bypass the local vision which is the drawback of GyTAR/EGyTAR protocols. Our proposed protocol has been developed over OMNET++ simulator, evaluated and compared with some other protocols. The simulation results show that the packet delivery ratio of our proposal is upper about 54% compared to GyTAR/EGyTAR and the end-to-end delay of our protocol is reduced by 75% for most of scenarios.

A Reputation based Weighted Clustering Protocol in VANET: A Multi-objective Firefly Approach

Vehicular Ad hoc NETworks (VANETs) possess a dominant role in the development of Intelligent Transport Systems (ITS). VANETs, due to the rapid mobility of vehicles are a highly dynamic network. In order to make the network topology suitable for effective communication, clustering algorithms are widely used. Clustering algorithms enable VANET to efficiently handle the changing topology for Medium Access Control (MAC), routing and several other applications. In this work we put forward a Reputation based Weighted Clustering protocol (RWCP) for VANETs. The RWCP is framed by taking the direction of vehicles, position, velocity, number of nearby vehicles, lane ID, and the reputation of each node into consideration for stabilizing the VANET topology. On the other hand, dealing with diverse control parameters of RWCP makes optimizing a challenging task. The work employs a multi-objective problem which takes the RWCP’s parameters as the input and aims at providing enhanced cluster lifetime, Improved packet delivery ratio and reduced cluster overhead. Multi Objective Firefly Algorithm (MOFA), an evolutionary approach is used for optimizing the RWCP’s parameters. Simulations were done using the TETCOS NetSim simulator and MOEA framework for optimization. The results are evaluated with similar evolutionary optimization techniques. Experiments were conducted with realistic maps from OpenStreet Maps and its results were compared with other multi-objective optimization techniques: Multi-objective Particle Swarm Optimization (MOPSO) and Comprehensive learning Particle Swarm Optimization (CL-PSO). The investigation proposes that, the proposed methodology performs well concerning the Mean Cluster Lifetime, Packet Delivery Ratio and Control Packer Overhead.

MAC protocols with dynamic interval schemes for VANETs

Under the dynamically changing topology of Vehicular Ad-hoc NETworks (VANETs), the restricted intervals in Medium Access Control (MAC) protocols cannot provide sufficient capacity to carry both safety and non-safety applications. One approach which can solve these issues is a dynamic MAC protocol that can adapt itself to the vehicle density or traffic conditions. In this survey, we, therefore, study various techniques for dynamic intervals used in MAC protocols, their advantages, and disadvantages. First, we classify these protocols into three following categories: 1) contention-based, 2) contention-free, and 3) a hybrid between contention-free and contention-based medium access methods. Second, in each medium access method, we classify the methodologies depending on their operating principles. The conclusions of our study are as follows: 1) Adaptive MAC protocols improve the channel utilization and adapt themselves to various traffic states, 2) Adaptive MAC protocols perform better than protocols using fixed intervals, 3) Currently, MAC protocols using dynamic intervals, which are suitable to VANET standards, are only applicable to optimize control channel interval; therefore, it is necessary to expand to both optimize control channel interval and service channel interval according to network and traffic condition. Finally, we discuss some open issues and whether designing MAC protocols using dynamic intervals can meet the QoS requirements for different applications in the future.

Hybrid error recovery protocol for video streaming in vehicle ad hoc networks

Recently, video streaming in Vehicular Ad hoc NETworks (VANETs) is considered as one of the most important challenge in vehicular communication because of the high packet loss rate and the increased transmission delay due to the highly dynamic of VANET topology. This specificity makes difficult to apply the conventional transport protocols such as UDP and TCP to video streaming over VANET. To deal with these limits and to ensure a high video quality at the end receiver, we propose in this paper a Hybrid Error Recovery Protocol (HERP) for video streaming in VANETs. The proposed protocol integrates the Sub-Packet Forward Correction (SPFEC) mechanism to recover the uniform transmission errors and the retransmission technique to recover burst errors mainly due to the network congestion and route disconnection. In order to avoid the network overload and to reduce the transmission delay, HERP adapts dynamically the redundancy rate, retransmission limit and transmission rate according to the network condition measured by the Bit Error Rate and the network load indicated by queue length of intermediate vehicles. HERP uses the reporting technique to control the network condition and the network load. To improve the video streaming quality, HERP suggests an unequal protection of video frames type (i.e. I, P, B frames). The experimental results show that HERP achieves significant improvements of transmitted video compared to native UDP protocol and UDP based on SPFEC.

A Novel Stable Clustering Approach based on Gaussian Distribution and Relative Velocity in VANETs

Vehicles in Vehicular Ad-hoc Networks (VANETs) are characterized by their high dynamic mobility (velocity). Changing in VANET topology is happened frequently which caused continuous network communication failures. Clustering is one of the solutions applied to reduce the VANET topology changes. Stable clusters are required and Indispensable to control, improve and analyze VANET. In this paper, we introduce a new analytical VANET's clustering approach. This approach aims to enhance the network stability. The new proposed grouping process in this study depends on the vehicles velocities mean and standard deviation. The principle of the normal (Gaussian) distribution is utilized and emerged with the relative velocity to propose two clustering levels. The staying duration of vehicles in a cluster is also calculated and used as an indication. The first level represents a very high stabile cluster. To form this cluster, only the vehicles having velocities within the range of mean ± standard deviation, collected in one cluster (i.e. only 68% of the vehicles allowed to compose this cluster). The cluster head is selected from the vehicles having velocities close to the average cluster velocity. The second level is to create a stable cluster by grouping about 95% of the vehicles. Only the vehicles having velocities within the range of mean ± 2 standard deviation are collected in one cluster. This type of clustering is less stable than the first one. The analytical analysis shows that the stability and the staying duration of vehicles in the first clustering approach are better than their values in the second clustering approach.