• KIPS Transactions on Computer and Communication Systems
• /
• v.5 no.3
• /
• pp.47-54
• /
• 2016

In this paper, we propose a new opportunistic routing scheme based on timed bargaining game. The proposed algorithm effectively formulates the opportunistic routing mechanism as an repeated bargaining model using timed learning method. Additionally, we formulate a new contention window adjusting scheme for reduce collision rate. Simulation results indicate that the proposed scheme has excellent performance than other existing schemes under widely diverse VANET environments.

• The KIPS Transactions:PartC
• /
• v.18C no.6
• /
• pp.405-412
• /
• 2011

Our proposed mobility management scheme is based on Multicasting and HIP(Host Identity Protocol) in PMIPv6(Proxy Mobile IPv6) Networks, and allows users to handoff within and across different administrative domains. The main advantage of our scheme is to enable the inter-domain handoff of both types of nodes with a reduced signalling overhead and packet losses. Specifically, the scheme enables the interworking between host-based and network-based mobility support, by means of the interaction between PMIPv6 with Multicasting and HIP. Performance evaluations demonstrate that our scheme improves the handoff latency and packet losses compared to other global mobility management protocols.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2013.11a
• /
• pp.214-217
• /
• 2013

Advancements in automobile industries and the communication technologies caused VANET (Vehicular Ad Hoc NETwork) to evolve to VANET-based clouds before its deployment. It is more likely that VANET clouds will replace the traditional VANET in the deployment phase. It is to be noted that an abrupt deployment is out of question because it would require mass of resources and money to do so; instead incremental deployment is more ideal. In this paper, we aim at the incremental deployment phase of VANET clouds and focus on the well-established public transport networks. Data aggregation is one of the essential aspects in traditional VANET and has been researched for quite long time. However the previously proposed schemes are still controversial. Keeping in mind the time and space prediction of public buses, we leverage these buses as potential aggregators and MG (Mobile Gateways) in VANET clouds. Buses gather cooperative whereabouts information from neighbors, aggregate that information, disseminate it to the neighbor MGs and also send it to the cloud for storage and for services exchange. In our proposed scheme, we believe that the dissemination will be effective and cover most of the urban area since at any instant of time; buses cover most part of the urban areas. Besides, the effective transmission range is higher due to tall buses.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.19 no.5
• /
• pp.93-103
• /
• 2009

Since message forgery or alteration in VANET may cause severe consequences, authentication of critical messages must be provided. However, using normal digital signature may infringe privacy of drivers. Therefore, VANET requires authentication systems that provide conditional anonymity. In this paper, we propose a new authentication system for VANET. In our proposed system, each vehicle can update its pseudonym using re-encryption technique and digitally sign messages using representation problem on the pseudonym. By limiting the usage period, revocation of individual pseudonym is not required. Moreover, we also provide a way to revoke the vehicle itself. Secureness of our system partially rely on the usage of tamper-resistance hardware.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.20 no.4
• /
• pp.53-62
• /
• 2010

In VANETs (Vehicular Ad hoc NETwork), conditional anonymity must be provided to protect privacy of vehicles while enabling authorities to identify misbehaving vehicles. To this end, previous systems provide a mechanism to revoke the anonymity of individual messages. In VANET, if we can trace the movement path of vehicles, it can be useful in determining the liability of vehicles in car accidents and crime investigations. Although route tracing can be provided using previous message revocation techniques, they violate privacy of other vehicles. In this paper, we provide a route tracing technique that protects privacy of vehicles that are not targeted. The proposed method can be employed independently of the authentication mechanism used and includes a mechanism to prevent authorities from abusing this new function.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.16 no.9
• /
• pp.3104-3123
• /
• 2022

The development of Vehicular Ad hoc Network (VANET) has greatly improved the efficiency and safety of social transportation, and the routing strategy for VANET has also received high attention from both academia and industry. However, studies on dynamic matching of routing policies with the message types of VANET are in short supply, which affects the operational efficiency and security of VANET to a certain extent. This paper studies the message types in VANET and fully considers the urgency and reliability requirements of message forwarding under various types. Based on the diversified types of messages to be transmitted, and taking the diversified message forwarding strategies suitable for VANET scenarios as behavioral candidates, an adaptive routing method for the VANET message types based on reinforcement learning (RL) is proposed. The key parameters of the method, such as state, action and reward, are reasonably designed. Simulation and analysis show that the proposed method could converge quickly, and the comprehensive performance of the proposed method is obviously better than the comparison methods in terms of timeliness and reliability.

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

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.33 no.2
• /
• pp.325-336
• /
• 2023

With the development of autonomous driving technology, the number of external contact sensors mounted on vehicles is increasing, and the importance is also rising. The vehicular ultrasonic sensor uses the LIN protocol in the form of a bus topology and reports a status message about its surroundings through the vehicle's internal network. Since ultrasonic sensors are vulnerable to various threats due to poor security protocols, physical testing on actual vehicle is needed. Therefore, this paper developed a LIN-CAN co-analysis testbed with a jig for location-specific distance test to examine the operational relation between LIN and CAN caused by ultrasonic sensors.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2022.11a
• /
• pp.144-146
• /
• 2022

차량 환경에서 발생하는 계산 집약적인 태스크가 증가하면서 모바일 엣지 컴퓨팅(MEC, Mobile Edge Computing)의 필요성이 높아지고 있다. 하지만 지상에 존재하는 MEC 서버는 출퇴근 시간과 같이 태스크가 일시적으로 급증하는 상황에 유동적으로 대처할 수 없으며, 이러한 상황을 대비하기 위해 지상 MEC 서버를 추가로 설치하는 것은 자원의 낭비를 불러온다. 최근 이 문제를 해결하기 위해 UAV(Unmanned Aerial Vehicle)기반 MEC 서버를 추가로 사용해 엣지 서비스를 제공하는 연구가 진행되고 있다. 그러나 UAV MEC 서버는 지상 MEC 서버와 달리 한정적인 배터리 용량으로 인해 서버 간 로드밸런싱을 통해 에너지 사용량을 최소화 하는 것이 필요하다. 본 논문에서는 UAV MEC 서버의 에너지 사용량을 고려한 마이그레이션 기법을 제안한다. 또한 GRU(Gated Recurrent Unit) 모델을 활용한 트래픽 예측을 바탕으로 한 마이그레이션을 통해 지연시간을 최소화할 수 있도록 한다. 제안 시스템의 성능을 평가하기 위해 MEC의 마이그레이션 시점을 결정하는 기준점와 차량의 밀도에 따라 실험을 진행하고, 서버의 로드 편차, UAV MEC 서버의 에너지 사용량 그리고 평균 지연 시간 측면에서 성능을 분석한다.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.9 no.2
• /
• pp.87-95
• /
• 2010

A Vehicular Ad-Hoc Network (VANET) is form of the Mobile Ad-hoc Network (MANET) to provide temporary communication among vehicles via wireless links. In VANET, the vehicle is one of the nodes in networks and communicates with each other. However, the wireless links disconnect very frequently, because vehicles have mobility and move freely. The reason why data accessibility degrades is that disconnection occurs frequently. To improve data accessibility, data replica allocation methods that made group to allocate data replica have proposed in MANET. However, those are not suitable because it is difficult to maintain stable links among the nodes moving fast by centralized group. In this paper, we proposed TBG (Tree Based Grouping) to allocate data replica with the distributed grouping method. Each node has own TBG and allocates data replica based on stability of links to improve data accessibility. The experiment demonstrates that the proposed method outperforms traditional methods in term of data accessibility.