• Journal of Ocean Engineering and Technology
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• v.11 no.4
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• pp.180-188
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• 1997

This paper proposes a new efficient MAC(Media Access Control) protocol to establish the ultrasonic communication network for underwater vehicles, which ensures a certain level of maximum throughput regardless of the propagation delay of ultrasonic and allows fast data transmission through the multiple ultrasonic communication channel. A MAC protocol for underwater communication network that allows 'peer-to-peer' communication between a surface ship and multiple underwater systems is designed, and the proposed control protocol is implemented for its verification.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.10
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• pp.899-905
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• 2016

Wireless access in vehicle environment (WAVE) communication is currently being researched as core wireless communication technologies for cooperative intelligent transport systems (C-ITS). WAVE consists of both vehicle to vehicle (V2V) communication, which refers to communication between vehicles, and vehicle to infrastructure (V2I) communication, which refers to the communication between vehicles and road-side stations. V2I has a longer communication range than V2V, and its communication range and reception rate are heavily influenced by various factors such as structures on the road, the density of vehicles, and topography. Therefore, domestic environments in which there are many non-lines of sight (NLOS), such as mountains and urban areas, require optimized communication channel modeling based on research of V2I propagation characteristics. In the present study, the received signal strength indicator (RSSI) was measured on both an experience road and a test road, and the large-scale characteristics of the WAVE communication were analyzed using the data collected to assess the propagation environment of the WAVE-based V2I that is actually implemented on highways. Based on the results of this analysis, this paper proposes a WAVE communication channel model for domestic public roads by deriving the parameters of a dual-slope logarithmic distance implementing a two-ray ground-reflection model.

• Journal of Advanced Navigation Technology
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• v.22 no.5
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• pp.391-399
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• 2018

V2X communication is a technology in which a vehicle exchanges information with various entities such as other vehicles, infrastructure, networks, pedestrians, etc. through a wired or wireless network. Recently, V2X communication technology has been steadily developed and recently it has played an important role in autonomous cooperation driving technology combined with autonomous vehicle technology. Autonomous vehicles can utilize the external information received via V2X communication to extend the recognition range of existing sensors and to support more safe and natural autonomous driving. In order to operate these autonomous cooperative vehicles on public roads, the security and reliability of autonomous V2X communication should be verified in advance. In this paper, we present test scenarios and test procedures of secure V2X communication for cooperative automated driving and present verification results.

• Journal of Auto-vehicle Safety Association
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• v.13 no.1
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• pp.26-30
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• 2021

K-city is an experimental area for developing self-driving cars. V2X communications such as WAVE, C-V2X and 5G are an essential technology for autonomous driving above level 4. In this paper, the research on the V2V communication environment was carried out through BSM receiving level analysis on the driving route in K-city. A stationary vehicle communicated with a test vehicle moving along urban area and suburban road in two different scenarios. The communication range and receiving levels obtained from this study will be used to develop and verify various safety scenarios using V2V communication within K-city in the future.

• ETRI Journal
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• v.45 no.6
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• pp.1065-1078
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• 2023

In vehicular networks, diverse safety information can be shared among vehicles through internet connections. In vehicle-to-internet communications, vehicles on the road are wirelessly connected to different cloud networks, thereby accelerating safety information exchange. Onboard sensors acquire traffic-related information, and reliable intermediate nodes and network services, such as navigational facilities, allow to transmit safety information to distant target vehicles and stations. Using vehicle-to-network communications, we minimize delays and achieve high accuracy through consistent connectivity links. Our proposed approach uses intermediate nodes with two-hop separation to forward information. Target vehicle detection and routing of safety information are performed using machine learning algorithms. Compared with existing vehicle-to-internet solutions, our approach provides substantial improvements by reducing latency, packet drop, and overhead.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.9
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• pp.3138-3151
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• 2022

Traffic safety and congestion are becoming more and more serious, especially the frequent occurrence of traffic accidents, which have caused great casualties and economic losses. Cellular Vehicle to Everything (C-V2X) can assist in safe driving and improve traffic efficiency through real-time information sharing and communication between vehicles. All vehicles communicate directly with Base Stations (BS), which will increase the base station load. And when the communicating vehicles are too far apart, too fast or there are obstacles in the communication path, the communication link can be unstable or even interrupted. Therefore, choosing an effective and reliable multi-hop relay-assisted Vehicle to Vehicle (V2V) communication can not only reduce the base station load and improve the system throughput but also expand the base station coverage and improve the communication quality of edge vehicles. Therefore, a communication area division scheme based on regular hexagon segmentation technology is proposed, a relay-assisted V2V communication mechanism is designed for the divided communication areas, and an efficient communication link is constructed by selecting the best relay node. Simulation results show that the scheme can improve the throughput of the system by nearly 55% and enhance the robustness of the V2V communication link.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.8
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• pp.1052-1057
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• 2020

With the development of new ICT technology, smart keys for vehicles are terminals with ICT technology. Therefore, when the vehicle and the smart key communicate with RF, a cyber hacking attack is possible. Cyber-attacks on smart keys can pose a threat to vehicle theft and vehicle control. Therefore, it is necessary to study hacking attacks and vulnerabilities of smart keys for autonomous vehicles. In this paper, we analyze the cyber attack case of RF communication for vehicles and smart keys. In addition, a real RF cyber attack on the smart key is performed, and the vulnerability of radio wave replication in the same frequency band is found. In this paper, we analyze the vulnerability of RF communication between vehicles and smart keys, and propose a countermeasure against cyber security. In the future, plans to strengthen cyber attacks and security through the popularization of autonomous vehicles will become basic data to protect human and vehicle safety.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.62 no.1
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• pp.23-29
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• 2013

TCN(train communication network) standard was approved in 1999 by the IEC (IEC 61375-1) and IEEE (IEEE 1473-T) organizations to warrant a reliable train and equipment interoperability. TCN defines the set of communication vehicle buses and train buses. The MVB(multifunction vehicle bus) defines the data communication interface of equipment located in a vehicle and the WTB(wire train bus) defines the data communication interface between vehicles. The WTB and each MVB will be connected over a node acting as gateway. Also, to support applications demanding a high reliability, the standard defines a redundancy scheme in which the bus may be double-line and redundant-node implemented. In this paper we have presented protocol analysis platform for the WTB redundancy which is part of TCN system, to verify communication state of high-speed trains. As a confirmation of its validity, the technology described in this paper has been successfully applied to state monitoring and protocol verification of redundancy WTB based on TCN.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.255-260
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• 2021

The importance of electric vehicles is gradually increasing due to the recent depletion of fossil fuels. In order to use an electric vehicle, the battery built into the vehicle must be frequently charged. Electric vehicles has very good performance in terms of noise and vibration. However, due to the limitations of the battery, the mileage is considerably shorter than that of an internal combustion engine vehicle once it is charged, and the battery charging time is relatively long compared to the refueling time. There are two types of charging methods for electric vehicle batteries: plug-in and wireless charging. In this paper, we introduced the wireless charging technology for electric vehicles and the current state of technology development and standards in major countries.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.2
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• pp.63-71
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• 2013

WAVE(Wireless Access for Vehicular Environment) System is a communication technology to monitor system failure and vehicle functions and management services to prevent possible incidents of driving a vehicle. In this paper, we have designed and implemented the mutual message processing through parameter between WME management module that manages WAVE system and MLME that manages the upper layer MAC(Media Access Control) module. Also, in order to verify the validity, we have carried out experiments to compare the speed of data processing by dividing data of 1Mbyte, 2Mbyte, 3Mbyte into the packets of 2KByte and 4KByte. Experiments data processing speed of 2KByte packet were shown about 173.62ms in 1MByte, 2MByte about 352.61ms, 3MByte about 550.13ms and, data processing speed of 4KByte packet, 1MByte approximately 87.56ms, 2MByte about 177.94ms, 3MByte about 277.18ms. Therefore, in WAVE system, the mutual messages processing through the parameters between WME and MLME module can be utilized in the various service of ITS(Intelligent Transportation Systems) depending on the speed of data processing.