• Journal of Korea Society of Digital Industry and Information Management
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• v.18 no.4
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• pp.23-30
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• 2022

Recently, traffic congestion and environmental pollution have occurred due to population concentration and vehicle increase in large cities. Various studies are being conducted to solve these problems. Most of the traffic congestion in cities is caused by traffic signals at intersections. This paper proposes a dynamic traffic light control (DTLC) scheme to support safe vehicle operation and smooth traffic flow using real-time traffic information based on VANET. DTLC receives instantaneous speed and directional information of each vehicle through road side units (RSUs) to obtain the density and average speed of vehicles for each direction. RSUs deliver this information to traffic light controllers (TLCs), which utilize it to dynamically control traffic lights at intersections. To demonstrate the validity of DTLC, simulations were performed on average driving speed and average waiting time using the ns-2 simulator. Simulation results show that DTLC can provide smooth traffic flow by increasing average driving speed at dense intersections and reducing average waiting time.

• International Journal of Computer Science & Network Security
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• v.23 no.2
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• pp.101-110
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• 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.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.1
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• pp.233-262
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• 2024

Due to the rapid evolution of vehicular ad hoc networks (VANETs), effective communication and security are now essential components in providing secure and reliable vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication. However, due to their dynamic nature and potential threats, VANETs need to have strong security mechanisms. This paper presents a novel approach to improve VANET security by combining the Vehicular Delay-Tolerant Network (VDTN) protocol with the Deep Reinforcement Learning (DRL) technique known as the Twin Delayed Deep Deterministic Policy Gradient (TD3) algorithm. A store-carry-forward method is used by the VDTN protocol to resolve the problems caused by inconsistent connectivity and disturbances in VANETs. The TD3 algorithm is employed for capturing and detecting Worm Hole Attack (WHA) behaviors in VANETs, thereby enhancing security measures. By combining these components, it is possible to create trustworthy and effective communication channels as well as successfully detect and stop rushing attacks inside the VANET. Extensive evaluations and simulations demonstrate the effectiveness of the proposed approach, enhancing both security and communication efficiency.

• The Journal of the Korea Contents Association
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• v.13 no.10
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• pp.27-36
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• 2013

Recently, as researches on VANET have actively progressed, the convenient and reliable services can be provided to the vehicles. In this paper, we propose the collaborative RSU scheduling scheme using multiple RSUs which are connected through a wired backbone. The proposed scheme efficiently disseminates both unsafety data and safety data, and reduces the deadline miss rate and the average response time. When safety data is occurred, it is send to previous RSU in advance and is scheduled by deadline and reception rate. We provide the prevention technology for unsafety data when the workload is occurred in RSU because it is on-demand data processed by user requests. It is shown through performance evaluation that the proposed scheme outperforms the existing scheme in terms of the deadline miss rate and the average response time according to the number of vehicles and the velocities of vehicles.

• The KIPS Transactions:PartC
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• v.16C no.5
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• pp.589-596
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• 2009

Until now, some protocols have been presented to provide vehicle's anonymity and unlinkability in VANET by means of issuing multiple anonymous certificates to each vehicle from the trust authority, or shot-time anonymous certificate to a vehicle after mutual authentication between a Roadside Unit (RSU) and the vehicle. However, these protocols have high overheads of the trust authority, RSUs and vehicles for generating anonymous certificate. In this paper, we propose an efficient anonymous authentication protocol, in which RSUs can issue multiple shot-time anonymous certificates to a vehicle to alleviate system overheads for mutual authentication between vehicles and RSUs. Several simulations are conducted to verify the efficiency of the proposed protocol in terms of RSU valid serve ratio and vehicle's computational costs. Moreover, the proposed protocol provides unlinkability and traceability when multiple RSUs are compromised, whereas previous protocols do not provide unlinkability and traceability.

• International Journal of Internet, Broadcasting and Communication
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• v.8 no.2
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• pp.49-54
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• 2016

Data delivery is very challenging in VANETs because of its unique characteristics, such as fast topology change, frequent disruptions, and rare contact opportunities. This paper tries to explore the scope of 3G-assisted data delivery in a VANET within a budget constraint of 3G traffic. It is started from the simple S_Random (Srand) and finally reached the 3GSDD, i.e., the proposed algorithm. The performance evaluation of different algorithms is done through the two metrics delivery ratio and average delay. A third function utility is created to reflect the above two metrics and is used to find out the best algorithm. A packet can either be delivered via multihop transmissions in the VANET or via 3G. The main challenge is to decide which set of packets should be selected for 3G transmissions and when to deliver them via 3G. The aim is to select and send those packets through 3G that are most sensitive and requiring immediate attention. Through appropriate communication mechanism, these sensitive information are delivered via VANET for 3G transmissions. This way the sensitive information which could not be transmitted through normal VANET will certainly find its destination through 3G transmission unconditionally and with top priority. The delivery ratio of the packets can also be maximized by this system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.7
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• pp.3465-3479
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• 2017

Information-Centric Vehicular Ad Hoc Network (IC-VANET) is a promising network architecture for the future intelligent transport system. Video streaming applications over IC-VANET not only enrich infotainment services, but also provide the drivers and pedestrians real-time visual information to make proper decisions. However, due to the characteristics of wireless link and frequent change of the network topology, the packet loss seriously affects the quality of video streaming applications. In this paper, we propose a REceiver-Driven loss reCOvery Mechanism (REDCOM) to enhance video dissemination over IC-VANET. A Markov chain based estimation model is introduced to capture the real-time network condition. Based on the estimation result, the proposed REDCOM recovers the lost packets by requesting additional forward error correction packets. The REDCOM follows the receiver-driven model of IC-VANET and does not require the infrastructure support to efficiently overcome packet losses. Experimental results demonstrate that the proposed REDCOM improves video quality under various network conditions.

• Journal of Korean Society of Transportation
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• v.28 no.4
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• pp.107-118
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• 2010

Wireless communication technologies including vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) enable the development of more sophisticated and effective traffic information systems. This study presents a method to estimate vehicular travel times in a vehicular ad hoc network (VANET) environment. A novel feature of the proposed method is estimating individual vehicle travel times through advanced on-board units in each vehicle, referred to as self-estimated travel time in this study. The method uses travel information including vehicle position and speed at each given time step transmitted through the V2V and V2I communications. Vehicle trajectory data obtained from the VISSIM simulator is used for evaluating the accuracy of estimated travel times. Relevant technical issues for successful field implementation are also discussed.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.11
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• pp.132-138
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• 2012

VANET(Vehicular Ad-hoc Network), standardization of IEEE 802.11p specification is in process. 802.11 MAC protocol grants all nodes equal opportunity to acquire channel without regard to their bit-rates, making it possible for lower bit-rate nodes to occupy communication channel for a fair amount of time thus keeping the higher bit-rate nodes from acquiring connection channel which downward-equalize the overall network performance. Also with the 802.11p MAC protocol, the probability of collision occurring increases as the number of nodes grow. The proposed algorithm is a new MAC protocol that guarantees nodes with acquired channel a firm priority over other nodes for a fixed amount of time with TXOP concept added to 'packet burst' according to the current transmitting speed. This newly designed algorithm allows the construction of wireless network with enhanced network throughput, decreased probability of collisions as well as providing the means to grant each node a fair chance of acquiring connection according to their channel conditions. The algorithm sets the CW's (Contention Window) width wider than the standard's and modulates the continuous transmitting threshold value depending on channel acquired time, thus improving the overall performance of the network.

• Journal of Digital Convergence
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• v.11 no.10
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• pp.379-385
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• 2013

MANET is not suitable to be applied to vehicle environments because of frequent path loss and path re-routing. To solve these problem, It is known that location-based routing protocol VANET is efficient. But, the VANET algorithm does not consider urban environments due to frequent vehicle movement and jamming by tall building. In this paper, we propose an efficient routing protocol to improve transfer efficiency and reduce transfer hop count. in urban networks.