scholarly journals Multi-Layer Problems and Solutions in VANETs: A Review

Electronics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 204 ◽  
Author(s):  
Usman Ali Khan ◽  
Sang Sun Lee

The Dedicated Short Range Communication (DSRC) technology supports the vehicular communications through Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I) Communication, by operating at 5.9 GHz band (U.S. Standard). The Physical (PHY) and Medium Access Control (MAC) Layer are defined by the IEEE 802.11p, while the IEEE 1609 family of standards define the Wireless Access in Vehicular Environment (WAVE); a suite of communication and security standards in the Vehicular Area Networks (VANETs). There has been a lot of research regarding several challenges in VANETs, from spectrum utilization to multichannel operation and from routing to security issues. The aim of all is to improve the performance of the network and support scalability in VANETs; which is defined as the ability of the network to handle the addition of vehicles (nodes) without suffering noticeable degradation of performance or administrative overhead. In this paper, we aim to highlight multilayer challenges concerning the performance of the VANETs, the already proposed solutions, and the possible future work.

2018 ◽  
Author(s):  
Μιχαήλ Χαρίτος

Η παρούσα διατριβή έχει ως θέμα τη μοντελοποίηση και ανάπτυξη ετερογενών κινητών δικτύων οχήματος-προς-όχημα (Vehicle to-Vehicle) και οχήματος-προς-υποδομή (Vehicle-to-Infrastructure) με έμφαση σε δύσκολα περιβάλλοντα μετάδοσης. Ειδικότερα η διατριβή προσέγγισε το πρόβλημα της έλλειψης αξιοπιστίας των εξομοιώσεων λόγω της διαφοροποίησης τους σε σύγκριση με πειραματικές μετρήσεις και ειδικότερα κατά την περίπτωση ασύρματης μετάδοσης εντός σήραγγας για εφαρμογές επιτήρησης εντός κινούμενων κόμβων (τρένο-οχήματα) με χρήση ετερογενών δικτύων. Για το σκοπό αυτό μελετήθηκαν με μεγάλη λεπτομέρεια μοντέλα καναλιού για την εξεύρεση του πλέον κατάλληλου. Ο πρώτος κατά σειρά στόχος της διατριβής όπως προαναφέρθηκε είναι η επιλογή/ανάπτυξη ενός αντιπροσωπευτικού μοντέλου καναλιού, για ασύρματα κινούμενα δίκτυα. Πιο συγκεκριμμένα, προτάθηκε με βάση πειραματικές μετρήσεις και επιλέχθηκε μοντέλο ασύρματου καναλιού για την περιοχή συχνοτήτων 5.4-5.9 GHz σε περιβάλλοντα σήραγγας αμαξοστοιχίας και αυτοκινητοδρόμου. Ο δεύτερος βασικός στόχος της παρούσας διατριβής ήταν ο σχεδιασμός και η αναπτύξη ενός αλγόριθμου μεταπομπής για τη βελτιστοποίηση των επιδόσεων σε συνθήκες μετάδοσης-λήψης οχημάτων – συρμών τρένων τα οποία κινούνται σε αντιπαράλληλες τροχίες εντός σήραγγας, κατά τη διαδικασία του WiMAX FBSS (Fast Base Station Switching) Handover και η σύγκρισή του με τον αντίστοχο Vertical Handover (VHO). O επόμενος στόχος ήταν ο σχεδιασμός ενός αλγόριθμου που στοχεύει στην βελτιστοποίηση του QoS του ασύρματου καναλιού κατά την περίπτωση ενός ασύρματου κινούμενου ετερογενούς (HetNet) IEEE 802.11p - LTE δικτύου οχημάτων με χρήση των τεχνικών SISO (single-input & single-output)και MIMO (multiple-input & multiple-output) εντός προαστιακού περιβάλλοντος. Ο αλγόριθμος περιλαμβάνει τη δυναμική ομαδοποίηση των οχημάτων σε clusters καθώς και την επιλογή Cluster Header (CH) και του αντίστοιχου Gateway για το Het-Net IEEE 802.11p – LTE. Για την πληρέστερη τεκμηρίωση των αποτελεσμάτων συγκρίθηκαν τα αποτελέσματα με αντίστοιχους Handover αλγόριθμους βασισμένους στην τεχνική του Clustering και αντιστοίχως για διαφορετική πυκνότητα και ταχύτητα οχημάτων. Για το σκοπό αυτό ο προτεινόμενος Handover αλγόριθμος εξομοιώθηκε μέσω της βιβλιοθήκης Veins του εξομοιωτή OMNeT++, με τη χρήση του SUMO – (Simulation of Urban Mοbility) εξομοιωτή. Μια ξεχωριστή συνεισφορά της διατριβής αποτέλεσε η ανάπτυξη της καινοτόμου μεθόδου του Virtual Drive testing μέσω της προσομοίωσης ενός αυτοκινούμενου LTE προτύπου για μια προεπιλεγμένη διαδρομή, με τη χρήση ενός LTE base station emulator, ενός Channel emulator, ενός RayTracing tool και μιας φορητής συσκευής σε ρόλο LTE κινούμενου κόμβου. Απώτερος στόχος του Virtual Drive testing είναι η χαρτογράφηση του LTE δικτύου ενός κινούμενου οχήματος σε μια προεπιλεγμένη περιοχή ενδιαφέροντος και η ρεαλιστική απεικόνιση των συνθηκών μετάδοσης με τη χρήση ενός Ray Tracing μοντέλου καναλιού σε προαστικό περιβάλλον. Τέλος, η έρευνα επεκτάθηκε στο σχεδιασμό και την εξομοίωση του προτεινόμενου Break-Point-PathLoss μοντέλου καναλιού σε περιβάλλον σήραγγας και εν συνεχεία εφαρμόστηκε σε ετερογενή WiMAX-WLAN δίκτυα. Με τη χρήση του προτεινόμενου Break-Point-PathLoss μοντέλου καναλιού ο χρήστης δύναται πλέον να εξομοιώσει με ακρίβεια οποιοδήποτε ασύρματο δίκτυο στον εξομοιωτή OMNeT++ και να παράξει αξιόπιστα αποτελέσματα για εφαρμογές ασύρματων δικτύων σε σήραγγα αρκεί να γνωρίζει τις γεωμετρικές διαστάσεις της.


2018 ◽  
Author(s):  
Thales T. Almeida ◽  
Lucas de C. Gomes ◽  
Fernando M. Ortiz ◽  
José Geraldo R. Júnior ◽  
Luís Henrique M. K. Costa

A embarcação de dispositivos com o padrão IEEE 802.11p no ambiente automotivo é considerado um fator crucial para alavancar a segurança e a eficiência no trânsito, o que torna fundamental a avaliação deste padrão antes de sua completa integração com sistemas reais. Entretanto, devido ao custo elevado e à pouca oferta de dispositivos comerciais, a maioria dos trabalhos envolvendo VANETs (Vehicular Ad-hoc NETworks) ainda é realizada apenas no campo das simulações. Visando comparar uma possível equivalência, este trabalho investiga os resultados de medições reais envolvendo cenários V2I (Vehicle-to-Infrastructure) e V2V (Vehicle-to-Vehicle). Para isso, foram confrontados os resultados obtidos por meio de OBUs (On-Board Units) e RSUs (Road Side Units) com os obtidos pelo simulador NS-3. Três métricas de rede foram avaliadas: o alcance máximo, a taxa de entrega de pacotes e o tempo entre recepções de pacotes. Também foi analisada a influência dos diferentes tipos de modulação permitidos no referido padrão e de diversos padrões de mobilidade. Este trabalho representa uma referência para a completa integração do padrão IEEE 802.11p e contribui para a validação e evolução dos modelos de simulação atuais.


2020 ◽  
Vol 17 (8) ◽  
pp. 3512-3515
Author(s):  
J. Refonaa ◽  
Y. Pavan Teja ◽  
Y. Manjunath ◽  
S. Dhamodaran ◽  
S. L. Jany Shabu ◽  
...  

Vehicular ad hoc networks (VANET) are otherwise called wise transportation frameworks. VANET guarantees auspicious and exact correspondences between vehicle to vehicle (V2V) and vehicle to infrastructure (V2I) to improve street wellbeing and upgrade the productivity of traffic stream. Because of its open remote limit and high versatility, VANET is powerless against pernicious hubs that could get entrance into the system and do genuine medium access control (MAC) layer dangers, for example, denial of service attacks, information alteration attacks, pantomime attacks, Sybil attacks, and replay attacks. With the prevalence of Block Chain comes grave security related concerns. Accomplishing security and discernibility at the same time stays an open inquiry. Endeavors have been made to address the issues, while they may expose to explicit situations. We propose a vehicular declaration convention Echo-Announcement in Credit Coin. It accomplishes productivity and protection safeguarding for the useful use in sending declarations. We plan an impetus component dependent on Block chain in Credit Coin. Clients oversee notoriety focuses while they acquire or spend coins as motivating forces. In the interim, Credit Coin despite everything jam security and accomplishes obscurity. Besides, in view of Block chain, Credit Coin forestalls numerous security attacks and accomplishes contingent protection since Trace administrator will follow malignant hubs when a startling occasion happens.


2019 ◽  
Vol 4 (2) ◽  
pp. 2
Author(s):  
Daniel Sempere García

Dentro de la tecnología 5G, las comunicaciones vehiculares V2X (Vehicle to Everything) han experimentado una importante evolución durante los últimos años. La tecnología planteada como punto de partida es la basada en el estándar IEEE 802.11p. Sin embargo, recientemente el 3GPP (Third Generation Partnership Project) ha estado trabajando en el desarrollo de la tecnología LTEV2X o 5G V2X, planteada como un estándar basado en LTE para comunicaciones V2X. Este estándar, cuya primera versión ya se encuentra cerrada (Release 14), define los mecanismos necesarios para llevar a cabo comunicaciones vehiculares como V2V (Vehicle to Vehicle) y V2I (Vehicle to Infrastructure). No obstante, ante el futuro despliegue de la tecnología del vehículo autónomo, que marca unos requisitos muy elevados en cuanto a factores como la latencia o la fiabilidad de las comunicaciones, el 3GPP se encuentra actualmente en fase de estudio y estandarización del Release 15, con el objetivo de dar soporte a los requisitos y servicios críticos de las comunicaciones del vehículo conectado y autónomo. En este trabajo se pretende revisar el estado del arte actual de las comunicaciones 5G V2X, así como de las mejoras que actualmente se encuentran en fase de investigación.


2013 ◽  
Vol 14 (4) ◽  
pp. 300-315 ◽  
Author(s):  
Vaishali D. Khairnar ◽  
Ketan Kotecha

Abstract Traffic safety applications using vehicle-to-vehicle (V2V) communication is an emerging technology and promising area within the ITS environment. Many of these applications require real-time communication with high reliability; to meet a real-time deadline, timely and predictable access to the channel. The medium access method used in 802.11p, CSMA with collision avoidance, does not guarantee channel access before a finite deadline. The well-known property of CSMA is undesirable for critical communications scenarios. The simulation results reveal that a specific vehicle is forced to drop over 80% of its packets because no channel access was possible before the next message was generated. To overcome this problem, we propose to use STDMA for realtime data traffic between vehicles. The real-time properties of STDMA are investigated by means of the highway road simulation scenario, with promising results.


Author(s):  
Oğuz Erçakır ◽  
Orkun Kızılırmak ◽  
Volkan Erol

Vehicle to vehicle (V2V) and Vehicle to infrastructure (V2I) or briefly V2X communications are the one of hot topics in automotive industry. Therefore, this situation is providing many advantages of connected vehicles and infrastructures which bring to human life. For instance, vehicles and road infrastructures which shares information with each other, provides a neat flow regulation, more ordered traffic flow and therefore jammed traffic dependent accident’s percentage will be decreased. On the other hand, security is the most important issue for these systems because the operation of V2X networks is completely dependent on uninterrupted and accurate information sharing. In the light of these information, in this paper we review security issues and current solution architectures. We also propose some open problems in this lively field.


Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3783
Author(s):  
Sumbal Malik ◽  
Manzoor Ahmed Khan ◽  
Hesham El-Sayed

Sooner than expected, roads will be populated with a plethora of connected and autonomous vehicles serving diverse mobility needs. Rather than being stand-alone, vehicles will be required to cooperate and coordinate with each other, referred to as cooperative driving executing the mobility tasks properly. Cooperative driving leverages Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I) communication technologies aiming to carry out cooperative functionalities: (i) cooperative sensing and (ii) cooperative maneuvering. To better equip the readers with background knowledge on the topic, we firstly provide the detailed taxonomy section describing the underlying concepts and various aspects of cooperation in cooperative driving. In this survey, we review the current solution approaches in cooperation for autonomous vehicles, based on various cooperative driving applications, i.e., smart car parking, lane change and merge, intersection management, and platooning. The role and functionality of such cooperation become more crucial in platooning use-cases, which is why we also focus on providing more details of platooning use-cases and focus on one of the challenges, electing a leader in high-level platooning. Following, we highlight a crucial range of research gaps and open challenges that need to be addressed before cooperative autonomous vehicles hit the roads. We believe that this survey will assist the researchers in better understanding vehicular cooperation, its various scenarios, solution approaches, and challenges.


Electronics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1221
Author(s):  
Anum Mushtaq ◽  
Irfan ul Haq ◽  
Wajih un Nabi ◽  
Asifullah Khan ◽  
Omair Shafiq

Connected Autonomous Vehicles (AVs) promise innovative solutions for traffic flow management, especially for congestion mitigation. Vehicle-to-Vehicle (V2V) communication depends on wireless technology where vehicles can communicate with each other about obstacles and make cooperative strategies to avoid these obstacles. Vehicle-to-Infrastructure (V2I) also helps vehicles to make use of infrastructural components to navigate through different paths. This paper proposes an approach based on swarm intelligence for the formation and evolution of platoons to maintain traffic flow during congestion and collision avoidance practices using V2V and V2I communications. In this paper, we present a two level approach to improve traffic flow of AVs. At the first level, we reduce the congestion by forming platoons and study how platooning helps vehicles deal with congestion or obstacles in uncertain situations. We performed experiments based on different challenging scenarios during the platoon’s formation and evolution. At the second level, we incorporate a collision avoidance mechanism using V2V and V2I infrastructures. We used SUMO, Omnet++ with veins for simulations. The results show significant improvement in performance in maintaining traffic flow.


2021 ◽  
Vol 13 (3) ◽  
pp. 68
Author(s):  
Steven Knowles Flanagan ◽  
Zuoyin Tang ◽  
Jianhua He ◽  
Irfan Yusoff

Dedicated Short-Range Communication (DSRC) or IEEE 802.11p/OCB (Out of the Context of a Base-station) is widely considered to be a primary technology for Vehicle-to-Vehicle (V2V) communication, and it is aimed toward increasing the safety of users on the road by sharing information between one another. The requirements of DSRC are to maintain real-time communication with low latency and high reliability. In this paper, we investigate how communication can be used to improve stopping distance performance based on fieldwork results. In addition, we assess the impacts of reduced reliability, in terms of distance independent, distance dependent and density-based consecutive packet losses. A model is developed based on empirical measurements results depending on distance, data rate, and traveling speed. With this model, it is shown that cooperative V2V communications can effectively reduce reaction time and increase safety stop distance, and highlight the importance of high reliability. The obtained results can be further used for the design of cooperative V2V-based driving and safety applications.


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