• Information and Communications Magazine
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• v.15 no.11
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• pp.124-142
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• 1998

ETSI BRAN (Broadband Radio Access Network)는 고속 무선 LAN 또는 고정 광대역 무선액세스 네트워크에서의 무선 접촉 계층과 ATM 및 IP(Internet Protocol) 코어 네트워크와의 연동을 위한 일부 기능을 표준화하기 위한 과제이다. 특히, BRAN의 HIPERLAN type-2(HIPERLAN/2)의 경우에는 과제의 범위는 무선 접속면, 무선 부시스템에서의 서비스 인터페이스, 서비스 구현에서 요구되는 연동 및 각종 지원 기능을 표준화하며, 무선 접속면의 경우에는 다수 벤더간의 상호 호환성을 제공할 수 있는 인터페이스를 구현하는 것이다. HIPERLAN/2의 기술 규격은 코어 네트워크와 독립적인 물리계층 및 데이터 링크 제어 (DATA Link Control: DLC) 계층과 서로 상이한 코어 네트워크와의 연동을 위한 네트워크 수렴 부계층을 다루게 될 것이며, 초기 단계에서는 ATM과 IP 코어 네트워크와의 연동 기능을 제시하게 될 것이다. 따라서 HIPERLAN/2기반의 시스템 규격을 제시하기 위해서는 네트워크 계층 및 기타 상위 계층에 대한 규격이 요규되며, 이는 ATM Forum에서의 무선 ATM 신호 방식 규격, IETF(Internet Engineering Task Force)의 IP규격, 그리고 ETSI의 SMG (Special Mobile Group) 프로젝트에서 표준화되고 있는 UMTS (Universal Mobile Telecommunication Service) 규격 등과 접목될 것이다. 결과적으로 무선 ATM 관점에서는 완전한 시스템 규격 작성은 ETSI BRAN과 ATM Forum에서 무선 접속 규격과 이동성 관리 및 신호 방식으로 각각 이원화되어 진행되고 있다. 현재 물리 계층에서의 전송 방식은 OFDM(Orthogonal Frequency Division Multiplexing)으로 확정되었으며, DLC 계층에서는 고정 길이의 TDD (Time Division Duplexing) TDMA 프레임 구조를 기반으로 AP (Access Point)에 의해 동적으로 상향 링크 자원을 예약 할당하는 매체 접근 제어 (Medium Access Control: MAC) 프로토콜이 고려되고 있다. 이와 같은 DLC 계층에서는 기본적으로 짧은 길이의 패킷을 통해 다양한 대역폭의 멀티미디어 트래픽을 효율적으로 수용하면서 ATM 네트워크뿐만 아니라 향후 IP 네트워크에서 요구하는 각 서비스별 QoS (Quality of Service)를 개별적으로 보장할 수 있는 기능을 구현하고자 한다. 향후 이 부문에 대한 표준화가 본격적으로 진행될 것으로 예상되며 HIPERLAN/2의 경우에는 1999년 중반까지 1차 기능 규격을 완료할 예정이며, BRAN 전반에 대한 완전한 규격을 2002년까지 완성하는 것을 목표로 하고 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.2B
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• pp.105-116
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• 2003

The differentiated service architecture is based on a simple model by applying a per-class service in the core node of the network. However, due to the simplified network behavior, the network structure and provisioning were more complicated. If a service provider wants the dynamic provisioning or better bandwidth guarantee, signaling protocol with QoS parameters or admission control method should be deployed in DiffServ network. However, these methods increase the complexity. Therefore, we proposed DPM2 mechanism for admission control in the DiffServ network. In this paper, we describe and survey the admission control methods that are applicable to IP networks and propose also the dynamic provisioning mechanism based on the bandwidth broker and distributed measurement based admission control and movable boundary bandwidth management to support heterogeneous QoS services in differentiated service networks. For the performance evaluation for proposed mechanism, we used ns-2 simulator.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.9
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• pp.1829-1836
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• 2009

A wireless Ad-hoc network is willing to send and receive data and for other nodes, and it is a temporal network where the nodes with mobility are automatically constituted. This network has been studied to construct networks in the state where there is no infrastructure. The limited nodes and its frequent moving in a wireless Ad-hoc network have resulted in frequent network disconnection. Therefore, the data transmission rate should be secured in a wireless Ad-hoc network. This study proposes the method to improve QoS of data transmission considering the mobility of nodes that respond to path searching by means of AOMDV routing protocol. By applying the suggested method, it is possible to raise the transmission rate by improving the reliability of transmission path.

• Journal of KIISE:Information Networking
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• v.32 no.4
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• pp.443-451
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• 2005

Stateful inspection devices must maintain flow information. These devices create the flow information also for network attack packets, and it can fatally inflate the dynamic memory allocation on stateful inspection devices under network attacks. The memory inflation leads to memory overflow and subsequent performance degradation. In this paper, we present a guideline to set the flow entry timeout for a stateful inspection device to remove harmful embryonic entries created by network attacks. Considering Transmission Control Protocol (TCP) if utilized by most of these attacks as well as legitimate traffic, we propose a parsimonious memory management guideline based on the design of the TCP and the analysis of real-life Internet traces. In particular, we demonstrate that for all practical purposes one should not reserve memory for an embryonic TCP connection with more than (R+T) seconds of inactivity where R=0, 3, 9 and $1\leqq{T}\leqq{2}$ depending on the load level.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.1
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• pp.65-73
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• 2006

Network based VPN(Virtual Private Network) using MPLS(Multiprotocol Label Switching) technology, called PE(Provider Edge router) based MPLS VPN, is regarded as a good solution for intranets or ext3nets because of the low cost and the flexibility of the service provision. In this paper, we describe a mechanism that allows the VPN users to move from one site to another site of the VPN network based on the BGP-E MPLS technology. This mechanism is designed for PE(Provider Edge) routers of the backbone network. PE routers connected to the VPN sites establish a new MPLS path to the mobile node after they detect movement of the mobile VPN node. The new location may belong to the same VPN or to different VPN. We desisted VPN management and control functions of the PE routers in order to interface with the Mobile IP protocol and support the QoS mechanism. The pilot implementation and performance measurement were carried out on a simulation using COVERS tool.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.11
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• pp.2347-2352
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• 2011

driver for safety always check the status of their vehicle, and it is essential to understand. But if you want to know the status of the driver of the vehicle in specialist referral time and money because it costs the operator shall be paid.IT technoligy with the development of the various features of your phone to check the status of the vehicle was able to do. However, the car' existing phone system, car diagnostic expertise must be learned because it will reveal the status of the vehicle do not have the expertise to not highlight the need for diagnostic. To reflect these points in smartphone users to easily use their own vehicles at a time to determine the status of a system that is required. In this paper, OBD-II protocol conversion WiFi OBD-II connector, retrieving information from the driver of the vehicle replacement cycle of consumables required vehicle inspection, vehicle problems in real-time diagnostic information to the user ease of use shows the iPhone implementation in the automotive supply was implemented based on the smartphone.

• Convergence Security Journal
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• v.12 no.1
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• pp.35-42
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• 2012

Increase of data traffic and the advent of new real-time services require to change from the traditional TDM-based (Time Division Multiplexing) networks to the optical networks that soft and dynamic configuration. Voice and lease line services are main service area of the traditional TDM-based networks. This optical network became main infrastructure that offer many channel that can convey data, video, and voice. To provide high resilience against failures, Packet-optical networks must have an ability to maintain an acceptable level of service during network failures. Fast and resource optimized lightpath restoration strategies are urgent requirements for the near future Packet-optical networks with a Generalized Multi-Protocol Label Switching(GMPLS) control plane. The goal of this paper is to provide packet-optical network with a hierarchical multi-layer recovery in order to fast and coordinated restoration in packet-optical network/GMPLS, focusing on new implementation information. The proposed schemes do not need an extension of optical network signaling (routing) protocols for support.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.11 s.353
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• pp.54-67
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• 2006

Low Rate WPAN (Wireless Personal Area Network) designed for low power and low cost wireless communication is an important technology to realize ubiquitous environment. IEEE 802.15.4 and ZigBee Alliance recommend the SKKE (Symmetric-Key Key Establishment) protocol for key establishment and management. The SKKE algorithm has security weakness such as the absence of authentication process or electric signature in key generation and exchange when devices join the role of coordinators. In this paper, we propose new key establishment and security algorithm based on public key encryption to solve low rate WPAN security problems. Also, to improve PLC AMR system's weaknesses in communication reliability and security, we propose a new AMR system model based on IEEE 802.15.4 and we apply our security algorithm to AMR profile for security enhancement.

• Journal of IKEEE
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• v.15 no.1
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• pp.104-112
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• 2011

During the ground operation of Korean army, the voice message is mainly used for exchanging informations related to the surveillance and reconnaissance, command and control, and precision strike. However, in order to the battlefield visualization among fighting powers participating in the ground force operation, automatic situational awareness and variable message format (VMF) for command and control are required. For securing core technologies necessary for the battlefield visualization, message standard and message handler are established through several applied researches. Besides, the VMF for equipping a weapon system is in development. In this paper, a study on the Korean variable message format (KVMF), where interoperability of integrated battle management system (BMS) is guaranteed due to performing joint, ground, and combined operations so that the situation awareness and strike system can be automated in almost real time, is presented. From the modeling and simulation (M&S) results of the message processor, delay time is varied in accordance with the number of nodes in unit platoon network, message length, and generation interval of routine messages. Therefore, it is shown that the system performance can be optimized by establishing proper network protocol for each situation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.4
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• pp.41-46
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• 2016

Recently, many domestic and foreign corporates are concentrating in investment to wearable devices and users are provided with various service based on wearable devices 26% more than compared to last year. It is widely used in previous healthcare, smart work, smart home environment, and it is now introduced to get connection to fused service environment. However, as products of G company are commercialized, the security issue of personal information is causing dispute in society, and the danger of data management and security regarding telecommunication is increasing. Also, because the password system used in previous wireless environment is still in use, there are possible vulnerability considering the new and mutant security threat. This thesis conducted study about protocols that can exercise safe telecommunication in the basis of wearable devices. In the registration and certification process, the signature value is created based on the code value. The telecommunication method is designed to conduct safe telecommunication based on the signature value. As for the attack method occurring in the wearable device environment, the safety was analyzed and conducted performance evaluation of previous password system and proposal system, and verified about 14% of efficiency.