A Robust Channel Access Using Cooperative Reinforcement Learning for Congested Vehicular 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.

SummaryDynamic nature of vehicular ad hoc networks (VANETs) creates great challenges for message dissemination. To satisfy the high reliability and low delivery latency requirements for safety applications in VANETs, a dynamic epidemic broadcasting model is presented in this paper. On the basis of the ordinary differential equations, the proposed optimal control scheme is analyzed to understand the epidemic broadcasting properties, which include the message delivery probability, the expected delivery latency, and the number of copies. The correctness of the theoretical analyses is confirmed by simulations, and the experiment results prove the efficiency of the optimal epidemic broadcasting model. Copyright © 2014 John Wiley & Sons, Ltd.

Vehicular Ad Hoc Network (VANET) is an extension to Mobile Ad Hoc Network (MANET) technology. VANET differs from MANET because it contains high mobility of nodes and large scale of networks. In this paper, real-time maps of certain areas in Shah Alam had been chosen and edited using JAVA Open Street Map editor (JOSM). Mobility Model Generator for VANET (MOVE) and Simulation of Urban Mobility (SUMO) are used to create the scenarios and traffics for urban and rural area network. The simulation is done in NS-2 with DSRC and Wi-Fi Direct standard using AODV routing protocol to evaluate various Quality of Service (QoS) parameters such as throughput, end-to-end delay, and packet delivery ratio (PDR) for the selected areas. The main discoveries of this paper are that the throughput and end-to-end delay increases as the number of mobile nodes increases. PDR does not get affected by the number of mobile nodes but instead depends on other factors including coverage of standards and traffic pattern. To summarize, VANET in rural scenario gives better performance as compared to the urban scenario.

Vehicular Ad Hoc Networks (VANETs) have been attracting more and more attention. However, due to the fast movement of vehicles and dynamic topology change, designing an efficient routing protocol in the complex urban environment is quite challenging. In this paper, an Intersection-based Geographic Routing with Transmission Quality guaranteed in Urban VANETs (IGRTQ) is proposed. As a selection guidance of the best route, each road segment is assigned with a weight based on the collected information related to the delay and connectivity of each road segment. Based on the weight information, the road segment can be dynamically selected one by one to form the optimized routing path, avoiding the local maximum and data congestion. An improved greedy strategy is further proposed to forward the packet along the selected road segment, ensuring the fast and reliable packet transmission. Simulation results show that the proposed protocol provides higher packet delivery ratio and lower end-to-end delay compared to the existing protocols.

Vehicular Ad-Hoc Networks (VANET) are a proper subset of mobile wireless networks, where nodes are revulsive, the vehicles are armed with special electronic devices on the motherboard OBU (On Board Unit) which enables them to trasmit and receive messages from other vehicles in the VANET. Furthermore the communication between the vehicles, the VANET interface is donated by the contact points with road infrastructure. VANET is a subgroup of MANETs. Unlike the MANETs nodes, VANET nodes are moving very fast. Impound a permanent route for the dissemination of emergency messages and alerts from a danger zone is a very challenging task. Therefore, routing plays a significant duty in VANETs. decreasing network overhead, avoiding network congestion, increasing traffic congestion and packet delivery ratio are the most important issues associated with routing in VANETs. In addition, VANET network is subject to various security attacks. In base VANET systems, an algorithm is used to dicover attacks at the time of confirmation in which overhead delay occurs. This paper proposes (P-Secure) approach which is used for the detection of DoS attacks before the confirmation time. This reduces the overhead delays for processing and increasing the security in VANETs. Simulation results show that the P-Secure approach, is more efficient than OBUmodelVaNET approach in terms of PDR, e2e_delay, throughput and drop packet rate.

Vehicular ad hoc networks (VANETs) are integral to intelligent transportation systems, enabling real-time vehicle communication to enhance safety and traffic flow. However, the dynamic topology, frequent disconnections, and limited bandwidth in VANETs pose significant challenges for efficient routing. To address these issues, we propose a SARSA-based reinforcement learning (RL) routing strategy that adapts to network changes by learning from environmental interactions. This approach updates routing decisions based on observed state-action pairs to optimize performance. We evaluate the proposed method against established protocols such as AODV, DSR, OLSR, GPSR, and DSDV. Results show a 57% reduction in average end-to-end delay, along with notable improvements in packet delivery ratio and throughput, demonstrating the effectiveness of RL in enhancing VANET routing performance.

The swift improvement of wireless communication technology has aided the creation of vehicular ad hoc networks (VANETs) as a revolutionary option for the realization of intelligent transportation systems (ITSs). VANETs facilitate seamless communication between vehicles and infrastructure (V2I) and among the vehicles themselves (V2V). These networks can enhance safety and traffic control while providing various infotainment options. To ensure stable and efficient communication in highly dynamic and quickly changing vehicular contexts, effective data packet routing is a crucial component of VANETs. This survey delves further into the VANET routing algorithms for ITS. The study aims to evaluate the effectiveness and acceptability of various routing protocols suggested for VANETs while considering their unique requirements and difficulties. The review covers ad hoc on‐demand distance vector (AODV) and dynamic source routing (DSR), as well as more current strategies designed specifically for VANETs, such as geographic routing, cluster‐based routing, and hybrid routing protocols. The review assesses the routing algorithms based on several vital parameters, including packet delivery ratio (PDR), end‐to‐end delay, throughput, network overhead, scalability, and robustness. This detailed assessment supports aspiring researchers in acquiring a better knowledge of the benefits and drawbacks of the routing algorithms currently used in VANETs.

The primary goal of Vehicular Ad-hoc Network (VANET) technology’s development is to increase road safety and enable Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) communication in order to share crucial information and prevent road accidents. VANET establishes a mobile network between moving cars by considering each vehicle as a separate entity. Safety applications in VANET are currently receiving a lot of attention from researchers as well as automobile manufacturers. This paper concentrate on simulation-based safety-critical techniques in vehicle networks employing radar and video sensors in various road styles. This paper discusses about how to create a simulation-based driving scenario environment and calculates the fluctuations in sensor detection rates depending on different driving conditions. And also created a basic Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) communication network. An integrated approach is also proposed to Forward Collision Warning System (FCWS) in different cases.

Vehicular Ad hoc Networks (VANETs) are a class of wireless networks built dynamically in an ad hoc network manner. VANET is a key technology for smart and Intelligent Transportation System. Efficient and intelligent algorithms for routing in VANETs are critically required for safety information propagation. Routing in highly dynamic VANET topology is important for the achievement of any vehicular safety applications. The routing mechanism in vehicular networks is critical because of VANETconstraints such as unpredictable network topology, frequent disconnections, varying network densities, etc. Multi agent scheme based routing scheme for VANETs is addressed in the paper. We address the challenge of how to route the data with short communication delay, overhead, and the complexity. Specifically, we consider the scenario for (V2V) vehicle-to-vehicle communication. Multi agent scheme consists of static agent and mobile agents. The scheme operates as follows: (1) establishing a connectivity pattern between the vehicles; (2) creating a set of beliefs; (3) desire development; (4) finalizing the intention. We validate the proposed scheme by simulation. Evaluated simulation results are packet delivery ratio, bandwidth utilization, and route identification delay.

Reliability is an important issue for safety-critical broadcast services in vehicular ad hoc networks (VANETs). So far, most investigations of such broadcast networks focus on multihop connectivity, taking all one-hop links for granted. In this paper, four reliability metrics for one-hop broadcast communication in VANETs, including the packet reception rate (PRR), the packet delivery ratio (PDR), the node successful packet delivery probability (PDP), and the effective range (ER), are introduced and evaluated analytically and by simulations. Expressions of these reliability metrics for one-hop broadcast in IEEE-802.11-based 1-D VANETs are derived with consideration of the IEEE 802.11 distributed coordination function (DCF), the hidden terminal problem, and collisions caused by concurrent transmissions. The impacts of network parameters such as distinct transmission, carrier sensing, and interference ranges; the density of nodes in the networks; the distances of receivers to the senders; the message generation rates; the backoff window sizes; and the channel data rates on the reliability of the broadcast communication in VANETs are investigated and discussed. As an example, the proposed model is applied to the evaluation of the dedicated short-range communication (DSRC) safety-critical message propagation in a highway setting. As a result, some important observations to the design and analysis of such communication systems are provided.

The exploration of Vehicular Ad Hoc Networks (VANETs) has garnered attention from scholars and businesses alike because of their changing structure and expected traffic flow patterns. VANETs offer an avenue to boost road safety by offering drivers up-to-the-minute updates and predictions regarding road conditions. As a version of Mobile Ad Hoc Networks (MANETs) VANETs consist of units that can communicate wirelessly and share information. This study explores elements of VANET (Vehicular Ad Hoc Networks) such, as structures and functions of networks connection points and the issues and methods used for guiding traffic efficiently to create a secure and dependable communication network system. Key indicators of performance like how many packets delivered (Packet Delivery Ratio. PDR) packet losses experienced during transmission processes are carefully analyzed to gauge the overall reliability of the system. Additionally, the research includes a comparison among routing strategies employed in VANET environments such as those based on network topology information or geographical location details, versus approaches centered around organized clusters of vehicles. Highlighting how these differ from methodologies typically seen in traditional cellular networks. This paper provides insights into how different routing protocols work in networking paradigms by examining different perspectives.

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%.

SFTD: A SMART forwarding technique based reliable data dissemination scheme for VANETs

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 network (VANET) is a promising technology for controlling traffic on roads. Nowadays, heavy traffic is a major issue, and the presence of attackers exacerbates the situation. The most important challenge in VANET is its security from malicious vehicles. In order to defend against distributed denial of service DDoS attacks, we propose a comprehensive verification header format bandwidth detection (CVHB) in VANET. The behavior of a DDoS attack is unknown for all the other normal nodes in network. The header format of packer contains all the information of nodes that are actively participating in routing. The attacker infection probability measured by 𝑃𝑏 and 𝑃𝑚 or (𝑃𝑏 > 0.9). If both the parameters are high means attacker presence confirm in network. The CVHB scheme checks the packet header format of the attacker node, and only the attacker is one of the nodes whose sequence number is frequently changing. So, CVHB blocks the flooding of unwanted packets that consume the limited bandwidth of a wireless link and identify packets that contain no useful information. To measure the performance of the network, the basic performance metrics that are used are dropping percentage, packet delivery ratio (PDR), throughput and delay. The result of CVHB is showing improvement as compared to multilayer distributed self-organizing maps (MSOM) in VANET.