• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.3
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• pp.568-577
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• 2017

IEEE Std 1609.2 was defined for the support of communication security functions in the WAVE (Wireless Access in Vehicular Environments) system. IEEE Std 1609.2 defined the message structures of the security services and managements on the vehicular communication by using ASN.1 (Abstract Syntax Notation One). Also, this security message structures shall be encoded using the COER (Canonical Octet Encoding Rules). In this paper, we designed and implemented the IEEE Std 1609.2 message encoder/decoder handling the security messages defined in IEEE Std 1609.2. The designed encoder/decoder consists of three modules as follows : a module generating the message of C language data structures in accord with IEEE Std 1609.2 message structures, a message encoder module, a message decoder module. And the encoder/decoder was implemented on the Linux environment. Also we analyzed the performance by measuring the performance speed of the encoder/decoder implemented.

• 한국ITS학회:학술대회논문집
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• 2005.11a
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• pp.183-185
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• 2005

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.1
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• pp.61-77
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• 2017

The most challenging issues in the multi-channel MAC of the IEEE 1609.4 standard is how to handle the dynamic vehicular traffic condition with a high mobility, dynamic topology, and a trajectory change. Therefore, dynamic channel coordination schemes between CCH and SCH are required to provide the proper bandwidth for CCH/SCH intervals and to improve the quality of service (QoS). In this paper, we use a Markov model to optimize the interval based on the dynamic vehicular traffic condition with high mobility nodes in the multi-channel MAC of the IEEE 1609.4 standard. We evaluate the performance of the three-dimensional Markov chain based on the Poisson distribution for the node distribution and velocity. We also evaluate the additive white Gaussian noise (AWGN) effect for the multi-channel MAC coordination scheme of the IEEE 1609.4 standard. The result of simulation proves that the performance of the dynamic channel coordination scheme is affected by the high node mobility and the AWGN. In this research, we evaluate the model analytically for the average delay on CCHs and SCHs and also the saturated throughput on SCHs.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.4 no.3 s.8
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• pp.1-8
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• 2005

IEEE WAVE(Wireless Access in Vehicular Environment) is being developed to operate in 5 GHz DSRC band to provide cars moving at high-speed with vehicle-to-vehicle and vehicle-to-roadside communication. IEEE P 1609.3 of the WAVE protocol stack defines how multiple channels are used based on the exchange of provider-service-tables (PST) and user-service-tables (UST) for rapid link establishment and data transmission. This paper presents the design and implementation of an IEEE WAVE multi-channel transmission emulator that we have developed to study the operation of protocol and applications. Applications for a public-safety and a download service have been implemented and are shown to operate effectively on top of the emulator.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.794-797
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• 2015

As the interest in VANET is increased, a study on the beacon message transmission between vehicles is actively being made. IEEE 802.11p/1609.4 standard is based on a multichannel system consisting of multiple service channels (SCH) and a control channel (CCH). Multiple SCHs are defined for nonsafety data transfer, while the CCH is used to broadcast safety messages called beacons and control messages (i.e., service advertisement messages). However, most messages broadcast in the only one CCH belong to safety application that must be contested in dense vehicular network. This paper suggests safety message transfer algorithm in dense vehicular congestion. The proposed algorithm is that the priority of safety messages is decided by decision tree and messages are stored in proper queues according to their priorities. Then, safety messages with higher priorities are sent in turn by CCH in the assigned time. The proposed algorithm decreases the beacon transmission delay and increase on the probability of a successful beacon reception in an IEEE 802.11p/1609.4-based network.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.624-627
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• 2014

In vehicular network, the basic goal is to provide vehicle safety service and commercial service such as ITS(Intelligent Transportation System) or video, etc on the road. And most research concentrated on transportation of safety message in congestion situation. It is important to allocate channel for safety message in congestion situation, but providing suitable service is also important problem in vehicular network. For this reason, IEEE 1609.4 allocate 4 multiple service channels (SCHs) for non-safety data transfer. But, in congestion situation with many vehicles, the contention for channel acquisition between services becomes more severe. So services are provided improperly because of lack of service channel. This paper suggests dynamic channel allocation algorithm. The proposed algorithm is that RSU(RaodSide Unit) maintain and manage the information about service and status of channels. On based of the SJF(Shortest Job First) scheduling using those information, RSU selects the most appropriate channel among the 4 SCHs allocated by IEEE 1609.4 in network congestion situation.

• Journal of IKEEE
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• v.19 no.3
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• pp.385-391
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• 2015

In this paper, we analyze the communication performance in a time synchronous multi-channel environment and deal with a packet collision avoidance technique to improve it based on IEEE1609.4 for increasing the efficiency of the control channel IEEE802.11p WAVE communication system. In previous works, they tried to solve this problem by message scheduling method on application layer software or changing the value of the random back-off optionally Contention Window. In this paper, we propose a method for adjusting the Channel Guard Interval for packet collision avoidance. The performance was evaluated by the actual vehicle test. The result was confirmed performance over 90% PDR(Packet Delivery Ratio).

• Journal of Advanced Navigation Technology
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• v.16 no.1
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• pp.54-61
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• 2012

The WAVE specification, which for the Next-Generation ITS environment is a common title: IEEE 802.11p and IEEE P1609 specifications. These days, there are many activities for researching WAVE specification by release of the IEEE 802.11p specification. The difference between high-speed vehicle environment and the indoor environment, the wireless communication channel mode is that much more severe. Thus, the wireless communication system design, temperature, noise, multipath fading and can degrade the performance of the system points should be fully considered matters of. In this paper, we showed WAVE wireless communication system which based on IEEE 802.11p PHY/MAC design process, and also showed solving process many implementation problems.

• IEIE Transactions on Smart Processing and Computing
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• v.6 no.2
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• pp.133-139
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• 2017

Vehicles have increasingly evolved and become intelligent with convergence of information and communications technologies (ICT). Vehicle communications (VC) has become one of the major necessities for intelligent vehicles. However, VC suffers from serious security problems that hinder its commercialization. Hence, the IEEE 1609 Wireless Access Vehicular Environment (WAVE) protocol defines a security service for VC. This service includes Advanced Encryption Standard-Counter with CBC-MAC (AES-CCM) for data encryption in VC. A high-speed AES-CCM crypto module is necessary, because VC requires a fast communication rate between vehicles. In this study, we propose and implement an efficient AES-CCM hardware architecture for high-speed VC. First, we propose a 32-bit substitution table (S_Box) to reduce the AES module latency. Second, we employ key box register files to save key expansion results. Third, we save the input and processed data to internal register files for secure encryption and to secure data from external attacks. Finally, we design a parallel architecture for both cipher block chaining message authentication code (CBC-MAC) and the counter module in AES-CCM to improve performance. For implementation of the field programmable gate array (FPGA) hardware, we use a Xilinx Virtex-5 FPGA chip. The entire operation of the AES-CCM module is validated by timing simulations in Xilinx ISE at a speed of 166.2 MHz.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.3
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• pp.1031-1046
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• 2018

Vehicular ad hoc network (VANET) is a dedicated network to connect vehicles without any centralized administration or infrastructure. The wireless access in vehicular environments (WAVE) protocol leveraging IEEE 1609/802.11p is widely implemented for VANETs. However, in congested traffic situation, the performance of the WAVE system degrades significantly due to serious collision, especially for safety related broadcast services on the control channel (CCH) interval due to the inherent drawback of its collision avoidance mechanisms called carrier sense multiple access with collision avoidance (CSMA/CA). In this paper, we propose a method that can decrease the number of frame collisions in CCH with a few modifications to the IEEE 802.11p protocol. In the paper, vehicles still employ CSMA/CA to compete for the channel access opportunity. However, by taking advantage of periodicity of synchronization interval, a two-state switching scheme introducing two new inter frame space (IFS) is proposed to reduce the number of competing vehicles substantially and as a result, the collision probability is significantly decreased. The simulation results demonstrate the superiority of the proposed method in packet collision rate.