Wireless Vehicular Ad-hoc Networks Research Articles

Performance analysis of cell-based spectrum handoff in cognitive radio vehicular centralized and ad-hoc networks

Spectrum handoff (SHO) is an essential technique in dynamic spectrum access policy to guarantee seamless and robust service of a cognitive radio. Link maintenance probability (LMP), link failure probability (LFP), service completion probability (SCP), probability mass function (PMF), and expected number of SHOs are key measuring metrics to characterize SHO performances in cognitive radio vehicular centralized network (CR-VCNET) and cognitive radio vehicular ad-hoc network (CR-VANET). In this paper, we develop and model the performance measuring parameters for a non-stationary cognitive user (CU) considering both complete service and incomplete service period under two CR network situations: opportunistic situation (OS or CR-VANET) and negotiated situation (NS or CR-VCNET). This paper analyzes the impact of CU mobility and spectrum hole mobility on various performance measuring metrics to explore the characteristics and performance of the CR networks. This paper also presents the comparison results for expected number of SHOs and SCP of a CU with and without mobility in both CR-VCNET and CR-VANET. The results of performance metrics obtain for a non-stationary CU under the impact of service time distributions are significantly different for CR-VCNETs and CR-VANETs. In addition, we also present Monte-Carlo simulation of LMP, LFP, and probability mass function of SHO for a non-stationary CU to validate the proposed model.

A Survey of Game Theoretical Approach in Cognitive Radio Network and 5G-6G Communications

The development of telecommunications, especially wireless communication, requires data transmission at high speed and wide bandwidth to support 5G-6G communication services. For this reason, it is necessary to have a network with adaptive capabilities in managing and improving performance parameters independently through an intelligent radio network system or better known as Cognitive Radio Network (CRN). The use of CRN in several implementations such as Cognitive Radio Ad Hoc Network (CRAHN), Cognitive Radio Vehicular Ad Hoc Networks (CR-VANET), Intelligent CRN and even 6G-CRN has also been widely used. Another method that is also used to optimize system performance independently is through the Game Theory (GT) approach. Game theory can be implemented on CRN as well as on 5G-6G communications. The use of GT in the CRN system provides improvements in terms of increasing system performance such as reducing interference and bit error rate (BER), increasing throughput and Signal to Interference plus Noise Ratio (SINR), power efficiency, increasing utility and resource capacity and being able to achieve convergence or reach the Nash equilibrium state more rapidly. Meanwhile, the use of GT in 5G-6G communication and other technologies are related to the power control, resource allocation, spectrum sharing, channel estimation, channel selection and Quality of Service (QoS) or Quality of Experience (QoE). In general, the use of GT can help to improve the overall performance of a system.

Spectrum Handoff Aware AODV Routing Protocol for Cognitive Radio Vehicular Ad Hoc Networks

End-to-end application performance and throughput of vehicular cognitive transport control protocol depend on how efficiently the segments (TCP header) are being transmitted from source to destination. One way to enhance the performance of vehicular cognitive TCP protocol is by reducing the packet drops in between the source and destination. In general, packet drops occur in between the source and destination of Cognitive Radio Vehicular Ad Hoc Network (CR-VANET) because of spectrum handoff or cognitive node handoff, or network congestion. In this paper, we focus on enhancing the performance of cognitive TCP protocol through “cognitive AODV routing protocol with the spectrum handoff mechanism.” In the proposed work, channel-route control messages of cognitive AODV routing protocol are updated with the support of spectrum handoff which helps to provide the backup opportunistic channel during PU active and helps to reduce the end-to-end spectrum handoff packet drops. Simulation results reveal that the overall performance of the vehicular cognitive TCP protocol with the proposed spectrum handoff aware cognitive AODV routing protocol is enhanced as compared to the existing cognitive TCP protocol.

Power allocation for cooperative communications in non-orthogonal cognitive radio vehicular ad-hoc networks

To achieve the better system performance for cooperative communication in non-orthogonal cognitive radio vehicular ad-hoc networks (CR-VANETs), this paper investigates the power allocation considering the interference to the main system in a controllable range. We propose a three-slot one-way vehicle system model where the mobile vehicle nodes complete information interaction with the assistance of other independent nodes by borrowing the unused radio spectrum with the primary networks. The end-to-end SNR relationship in overlay and underlay cognitive communication system mode are analyzed by using two forwarding protocol, namely, decode-and-forward (DF) protocol and amplify-and-forward (AF) protocol, respectively. The system outage probability is derived and the optimal power allocation factor is obtained via seeking the minimum value of the approximation of system outage probability. The analytical results have been confirmed by means of Monte Carlo simulations. Simulation results show that the proposed system performance in terms of outage under the optimal power allocation is superior to that under the average power allocation, and is also better than that under other power allocation systems.

Single‐channel slotted contention in cognitive radio vehicular networks

Cognitive radio vehicular ad-hoc networks (CR-VANETs) allow the vehicles to exploit the unused channels in their vicinity to fulfil the bandwidth demands of infotainment applications. Existing CR-VANET approaches aim at incorporating spectrum sensing and reporting to the widely used IEEE 802.11p standard developed for VANETs. However, all such approaches were developed for CR-VANETs with low vehicular traffic densities. Applying such approaches at high traffic densities results in long sensing periods, long contention periods with frequent collisions and unnecessary transmissions of sensing information, and variable delays that depend on the vehicular density. In this study, the authors present the single-channel slotted contention ( ( SC ) 2 ) protocol designed for highways with highly dense vehicular traffic. The ( SC ) 2 protocol counters the deficiencies of typical CR-VANETs in high-density networks using three components: random single-channel sensing, slotted contention, and implicit-OR aggregation. The proposed protocol can be easily incorporated with the IEEE 802.11p. Analytic and simulation results show that the proposed protocol increases the CR-VANET throughput and the overall spectrum utilisation while significantly decreasing the radio environment map time in high densities when compared to the conventional IEEE 802.11p protocols.

Securing Cognitive Radio Vehicular Ad Hoc Network with Fog Node based Distributed Blockchain Cloud Architecture

Cognitive radio, ad hoc networks' applications are continuously increasing in wireless communication globally. In vehicles' environment, cognitive radio technology with mobile ad hoc networks (MANETs) enables vehicles to monitor the available channels and to effectively function in these frequencies through sharing ongoing information with drivers and different frameworks to enhance traffic safety on roads. To fulfill the computational storage resources’ limitations of a specific vehicle, Vehicular Cloud Computing (VCC) is used by merging VANET with cloud computing. Cloud computing requires high security and protection because authenticate users and attackers have the same rights in VCC. The security is enhanced in CRVANETs, but the distributed nature of cloud unlocks a door for dissimilar attacks, such as trust modal, data security, connection fault and query tracking attacks. This paper proposes an effective and secured blockchain scheme-based distributed cloud architecture in place of conventional cloud architecture to secure the drivers’ privacy with low cost and on-demand sensing procedure in CRVANETs ecosystem.

Towards low-delay and high-throughput cognitive radio vehicular networks

Abstract Cognitive Radio Vehicular Ad-hoc Networks (CR-VANETs) exploit cognitive radios to allow vehicles to access the unused channels in their radio environment. Thus, CR-VANETs do not only suffer the traditional CR problems, especially spectrum sensing, but also suffer new challenges due to the highly dynamic nature of VANETs. In this paper, we present a low-delay and high-throughput radio environment assessment scheme for CR-VANETs that can be easily incorporated with the IEEE 802.11p standard developed for VANETs. Simulation results show that the proposed scheme significantly reduces the time to get the radio environment map and increases the CR-VANET throughput.

Joint Routing and Scheduling in Cognitive Radio Vehicular Ad Hoc Networks

Joint Routing and Scheduling in Cognitive Radio Vehicular Ad Hoc Networks

Performance Evaluation of Data Delivery Mechanism For Cognitive Radio Vehicular and Vehicular Ad-Hoc Networks

Recently, the Vehicular Networks are gaining increased attention for generating extensive wireless communication. They are also integrated with Cognitive Radio to further enhance their performance. However the guaranteed delivery of data is an important parameter for evaluating these networks. This paper provides a simple, but nevertheless extremely accurate, simple model to evaluate the performance of both Vehicular Ad-hoc and Cognitive Radio Vehicular Networks. The proposed analysis applies to both the networks on the basis of various parameters like delay, packet loss, packet drop ratio, throughput using extensive simulation. The results validate the assumption that Cognitive Vehicular Radios outperform the” VANET's when various types of packets are transmitted using V2 V communication.

English

Uncovering & Anticipation of malicious attacks in networking field is an important and challenging security issue in Vehicular Adhoc Networks (VANET).VANETs are dynamic wireless networks without any infrastructure. The dynamic topology of VANET allows nodes to join and leave the network at any point of time. Wireless VANET is particularly vulnerable due to its fundamental characteristics such as open medium, dynamic topology, distributed cooperation and constrained capability. So security in VANET is a complex issue. These networks are weak against many types of attacks. Black hole attack which is one of the possible attacks on AODV routing protocol in vehicular ad hoc networks. In this attack, a malicious node advertises itself as having freshest or shortest path to specific node to absorb packets to itself. The effect of Black hole attack on Adhoc network using AODV as a routing protocol will be studied in this paper. The proposed solution that is capable of detecting and removing Black hole nodes in the VANET at the initial stage itself without any delay. Furthermore, we investigate solution for increasing security in these networks.

Density-Based Opportunistic Broadcasting Protocol for Emergency Situations in V2X Networks

Vehicular-to-anything (V2X) technology is attractive for wireless vehicular ad-hoc networks (VANETs) because it allows for opportunistic choice of a vehicular protocol between vehicular-to-vehicular (V2V) and vehicular-to-infrastructure (V2I) communications. In particular, achieving seamless connectivity in a VANET with nearby network infrastructure is challenging. In this paper, we propose a density-based opportunistic broadcasting (DOB) protocol, in which opportunistic connectivity is carried out by using the nearby infrastructure and opposite vehicles for solving the problems of disconnection and long end-to-end delay times. The performance evaluation results indicate that the proposed DOB protocol outperforms the considered comparative conventional schemes, i.e., the shortest path protocol and standard mobile WiMAX, in terms of the average end-to-end delay, packet delivery ratio, handover latency, and number of lost packets.

Navigation-aware association control in vehicular wireless networks

Currently, internetworking over Wireless Vehicular Ad Hoc Networks VANET is getting more attention and discussion. Mobile devices, including smartphones, laptops and PDAs, associate with nearby access points that are located on the roadside to access Internet in VANETs. Hence, people can use these devices to communicate in VANETs. However, the unbalanced traffic distribution often occurs among the APs in the networks, which leads to unfair bandwidth share for each user. This situation may get worse in VANETs composed of thousands of high mobility vehicles. Hence, this study focuses on association control to achieve load balancing among APs RSUs, and we propose a novel association control algorithm with an aid of the navigation system. Based on the use of fully-fledged navigation system, our proposed algorithm plans a RSU-association-schedule, which selects a series of appropriate RSUs roadside units in advance to reach destination and meanwhile achieves load balancing among RSUs. The simulation results show that our scheme does improve the fairness and overall performance in VANETs.