• Journal of Communications and Networks
• /
• 제15권2호
• /
• pp.207-216
• /
• 2013

Vehicular ad-hoc networks (VANETs) are self-organizing, self-healing networks which provide wireless communication among vehicular and roadside devices. Applications in such networks can take advantage of the use of simultaneous connections, thereby maximizing the throughput and lowering latency. In order to take advantage of all radio interfaces of the vehicle and to provide good quality of service for vehicular applications, we developed a seamless flow mobility management architecture based on vehicular network application classes with network-based mobility management. Our goal is to minimize the time of flow connection exchange in order to comply with the minimum requirements of vehicular application classes, as well as to maximize their throughput. Network simulator (NS-3) simulations were performed to analyse the behaviour of our architecture by comparing it with other three scenarios. As a result of this work, we observed that the proposed architecture presented a low handover time, with lower packet loss and lower delay.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2013년도 춘계학술발표대회
• /
• pp.610-613
• /
• 2013

Vehicular Ad Hoc NETwork (VANET), a subclass of Mobile Ah Hoc NETwork (MANET) has been a tech-buzz for the last couple of decades. VANET, yet not deployed, promises the ease, comfort, and safety to both drivers and passengers once deployed. The by far most important factor in successful VANET application is the data dissemination scheme. Such data includes scheduled beacons that contain whereabouts information of vehicles. In this paper, we aim at regularly broadcasted beacons and devise an algorithm to disseminate the beacon information up to a maximum distance and alleviate the broadcast storm problem at the same time. According to the proposed scheme, a vehicle before re-broadcasting a beacon, takes into account the current vehicular density in its neighborhood. The re-broadcasters are chosen away from the source of the beacon and among the candidate re-broadcasters, if the density in the neighborhood is high, then the candidate rebroadcaster re-broadcasts the beacon with high probability and with low probability, otherwise. We also performed thorough simulations of our algorithms and the results are sound according to the expectations.

• Journal of Communications and Networks
• /
• 제17권1호
• /
• pp.58-66
• /
• 2015

Aeronautical communication networks (ACN) is an emerging concept in which aeronautical stations (AS) are considered as a part of multi-tier network for the future wireless communication system. An AS could be a commercial plane, helicopter, or any other low orbit station, i.e., Unmanned air vehicle, high altitude platform. The goal of ACN is to provide high throughput and cost effective communication network for aeronautical applications (i.e., Air traffic control (ATC), air traffic management (ATM) communications, and commercial in-flight Internet activities), and terrestrial networks by using aeronautical platforms as a backbone. In this paper, we investigate the issues about connectivity, throughput, and delay in ACN. First, topology of ACN is presented as a simple mobile ad hoc network and connectivity analysis is provided. Then, by using information obtained from connectivity analysis, we investigate two communication models, i.e., single-hop and two-hop, in which each source AS is communicating with its destination AS with or without the help of intermediate relay AS, respectively. In our throughput analysis, we use the method of finding the maximum number of concurrent successful transmissions to derive ACN throughput upper bounds for the two communication models. We conclude that the two-hop model achieves greater throughput scaling than the single-hop model for ACN and multi-hop models cannot achieve better throughput scaling than two-hop model. Furthermore, since delay issue is more salient in two-hop communication, we characterize the delay performance and derive the closed-form average end-to-end delay for the two-hop model. Finally, computer simulations are performed and it is shown that ACN is robust in terms of throughput and delay performances.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2018년도 추계학술대회
• /
• pp.62-65
• /
• 2018

This paper comes out with the study on sensing data collection strategy in a Software-Defined Mobile Edge vehicular networking. The two cooperative data dissemination are Direct Vehicular cloud mode and edge cell trajectory prediction decision mode. In direct vehicular cloud, the vehicle observe its neighboring vehicles and sets up vehicular cloud for cooperative sensing data collection, the data collection output can be transmitted from vehicles participating in the cooperative sensing data collection computation to the vehicle on which the sensing data collection request originate through V2V communication. The vehicle on which computation originate will reassemble the computation out-put and send to the closest RSU. The SDMEVN (Software Defined Mobile Edge Vehicular Network) Controller determines how much effort the sensing data collection request requires and calculates the number of RSUs required to support coverage of one RSU to the other. We set up a simulation scenario based on realistic traffic and communication features and demonstrate the scalability of the proposed solution.

• 로봇학회논문지
• /
• 제6권2호
• /
• pp.97-107
• /
• 2011

This paper describes efficient flight control algorithms for building a reconfigurable ad-hoc wireless sensor networks between nodes on the ground and airborne nodes mounted on autonomous vehicles to increase the operational range of an aerial robot or the communication connectivity. Two autonomous flight control algorithms based on adaptive gradient climbing approach are developed to steer the aerial vehicles to reach optimal locations for the maximum communication throughputs in the airborne sensor networks. The first autonomous vehicle control algorithm is presented for seeking the source of a scalar signal by directly using the extremum-seeking based forward surge control approach with no position information of the aerial vehicle. The second flight control algorithm is developed with the angular rate command by integrating an adaptive gradient climbing technique which uses an on-line gradient estimator to identify the derivative of a performance cost function. They incorporate the network performance into the feedback path to mitigate interference and noise. A communication propagation model is used to predict the link quality of the communication connectivity between distributed nodes. Simulation study is conducted to evaluate the effectiveness of the proposed reconfigurable airborne wireless networking control algorithms.

• 한국정보과학회논문지:정보통신
• /
• 제37권6호
• /
• pp.420-430
• /
• 2010

Vehicular Ad Hoc Network(VANET)은 차량과 차량, 차량과 네트워크 기반 구조 간에 통신을 지완하는 네트워크로서, 다양한 서비스를 제공할 수 있어 학문적으로나 상업적으로 많은 관심을 받고 있다. 그러나 VANET이 널려 사용되기 위해서는 보안과 프라이버시 관련 문제들이 선행적으로 해결되어야 한다. VANET은 무선 통신과 ad hoc network의 성질을 그대로 이어받아, 다양한 보안 취약점이 존재하며 이에 따라 다양한 공격이 가능하다. 또한, 프라이버시 요구사항을 만족시키지 못하는 경우, 공격자는 특정 차량에 때해서 추적할 수 있으며, 운전자의 민감한 개인정보들이 노출될 수 있다. VANET에서 프라이버시와 보안을 제공하기 위해 많은 연구들이 진행되었지만, 대부분이 차량 간의 통신 혹은 차량과 네트워크 기반 구조 간의 통신 중 하나에만 집중하고 있으며, 차량의 폐지목록(Revocation List)으로 인해 많은 네트워크 자원을 소비하고 있다. 본 논문에서는 차량과 네트워크 기반구조간의 효율적인 상호 인증을 제공하고, 상호인증 시 네트워크 기반 구조가 차량에게 짧은 시간 동안 차량과 차량 간의 통신에서 사용할 익명 인증서를 생성해주는 프로토콜을 제안한다. 보안 분석을 통해 제안한 프로토콜이 차량과 차량, 차량과 네트워크 기반 구조간의 안전한 통신을 보장하고, 차량의 프라이버시를 보호할 수 있음을 확인 하였으며, 성능 분석을 통해 제안한 프로토콜이 기존의 연구들 보다 높은 효율성을 지니고 있음을 검증하였다.

• International Journal of Computer Science & Network Security
• /
• 제24권9호
• /
• pp.195-201
• /
• 2024

Vehicular Ad-hoc Networks (VANETs) became very popular in few years and it has been widely used in research and industry communities. VANET is a collection of wireless vehicle nodes forming a temporary network without using any centralized Road Side Unit (RSU). VANET is a subset of Mobile Adhoc Networks (MANET). It improves the safety of vehicles. It also supports Intelligent Transportation Systems.Routing is the major component of communication protocols in VANETs. Packets are to be routed from the source node to destination node. Because of frequent topology changes and routing overhead, selection of routing protocol in VANET is a great challenge. There are various routing protocols available for VANET. This paper involves study of Temporally Ordered Routing protocol (TORA) and performance metrics are analyzed with the help of NS2 Simulator.

• International Journal of Computer Science & Network Security
• /
• 제24권8호
• /
• pp.139-144
• /
• 2024

VANETs have become one of the most attractive research areas in the world of wireless networks in recent years. Indeed, vehicular networks have become capable of optimizing road traffic, which significantly reduces the number of accidents through notifications exchanged between nearby vehicles. The routing function based on the opportunistic algorithm is a critical part of the vehicle's communication system and will therefore be an ideal target for attacks that could aim to prevent alert messages from reaching their destination, and thus endanger human lives. The black hole attack is a major threat to the security of VANETs. The main idea of this paper focuses on the analysis of this type of attack in VANETs using Discrete-Time Markov Chains (DTMC). and deduce at the end the effect of the number of malicious nodes on the delivery rate in the network.

• 디지털산업정보학회논문지
• /
• 제13권1호
• /
• pp.79-85
• /
• 2017

Vehicular ad-hoc networks (VANETs) cause link disconnection problems due to the rapid speed and the frequent moving direction change of vehicles. Link disconnection in vehicle-to-vehicle communication is an important issue that must be solved because it decreases the reliability of packet forwarding. From the characteristics of VANETs, greedy forwarding protocols using the position information based on the inter-vehicle distance have gained attention. However, greedy forwarding protocols do not perform well in the urban environment where the direction of the vehicle changes greatly. It is because greedy forwarding protocols select the neighbor vehicle that is closest to the destination vehicle as the next transmission vehicle. In this paper, we propose a greedy anycast forwarding (GAF) protocol to improve the reliability of the inter-vehicle communication. The proposed GAF protocol combines the greedy forwarding scheme and the anycast forwarding method. Simulation results show that the GAF protocol can provide a better packet delivery rate than existing greedy forwarding protocols.

• International Journal of Computer Science & Network Security
• /
• 제23권2호
• /
• pp.101-110
• /
• 2023

Vehicular Ad Hoc Network (VANET) is considered to be a subclass of Mobile Ad Hoc Networks (MANET). It has some challenges and issues of privacy which require to be solved before practical implementation of the system i.e., location preservation privacy. Many schemes have been proposed. The most prominent is pseudonym change based location preservation scheme. Safety message can be compromised when it sends via a wireless medium, consequently, an adversary can eavesdrop the communication to analyze and track targeted vehicle. The issue can be counter by use of pseudo identity instead of real and their change while communication proves to be a sufficient solution for such problems. In this context, a large amount of literature on pseudonym change strategies has been proposed to solve such problems in VANET. In this paper, we have given details on strategies proposed last two decades on pseudonym change based location preservation along with issues that they focus to resolve and try to give full understanding to readers.