• 한국통신학회논문지
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• 제30권4A호
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• pp.241-249
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• 2005

ATM based MPLS(Multiprotocol Label Switching) is discussed for its provisioning QOS commitment capabilities, Traffic engineering and smooth migration for BcN in Korea. At this time, due to the comprehensive nature of ATM protocol, ATM has been adapted as the backbone system for carrying Internet traffic[1,2,3,4]. This paper presents preventive congestion control mechanisms for detecting HTR(Hard-To-Reach) LSP(Label Switched Path) in ATM based MPLS systems. In particular, we have introduced a HTR LSP detection method using network signaling information in an ATM layer. MPLS related studies can cover LSP failures in a physical layer fault, it can not impact network congestion status. Here we will present the research results for introducing HTR LSP detection methods and control mechanisms and this mechanism can be implementing as SOC for high speed processing a packet header. We concluded that it showed faster congestion avoidance abilities with a more reduced system load and maximized the efficiency of network resources by restricting ineffective machine attempts.

• 전자통신동향분석
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• 제19권5호통권89호
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• pp.134-142
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• 2004

SBLIM은 GNU/Linux 시스템의 이용도를 제공하기 위하여 IBM이 추진하고 있는 공개소스 프로젝트이다. 오늘날 GNU/Linux 시스템을 비롯한 여러 운영체제(OS)는 독자적인 시스템 관리 방법 및 도구를 제공하고 있어 이기종 시스템간 관리의 일관성을 보장할 수 없다. 이와 같은 현상은 첫째, 시스템 자원에 대한공통 정보 모델이 정의되지 않았고, 둘째, 메시지 전달 인터페이스의 표준화가 결여되어 있기 때문에 발생한다. 또한 지금까지의 시스템 관리 솔루션이 시스템 자원의 특성과 독립적으로 구현되어 이기종 플랫폼에 대한 자원관리를 일관된 방법으로 가능하게 하는 시스템 관리 솔루션의 등장을 방해해왔다. SBLIM은 이러한 문제점을 해소하기 위해 등장하였으며, 본 논문에서는 SBLIM의 개요, 구조 및 국내외 개발 동향을 중심으로 살펴본다.

• 산업경영시스템학회지
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• 제28권1호
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• pp.97-104
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• 2005

Considered is the concurrent spare part(CSP) requirements problem of new equipment system. In the considered system, when a part fails, the part cannot be repaired and should be replaced. In addition, cannibalization is allowed. It is assumed that the failure of a part follows a Poisson process. The operational availability concept in CSP is defined, and a formula is derived to calculate the operational availability using expected machine operating time during CSP period. The problem is formulated as the operational availability maximization problem with available budget constraint and a heuristic solution search procedure is developed. An illustrative example is shown to explain the solution procedure.

• 한국컴퓨터정보학회논문지
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• 제21권11호
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• pp.65-71
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• 2016

This paper proposes a novel traffic and resource management scheme based on Service Level Agreement (SLA) which allows to guarantee the quality of experience (QoE) for various high-quality mobile multimedia service users to a certain level. For this purpose, QoE-SLA coupling structure is considered and a novel scheme is suggested to suppress the processing delay of the mobile terminal and to decrease the transfer delay in the transmission network. According to simulation results, our proposed scheme can increase the total throughput and decrease the average delay by adjusting SLA.

• 전자통신동향분석
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• 제19권1호통권85호
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• pp.9-21
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• 2004

차세대 통신 시스템은 다양한 IP 멀티미디어 응용을 지원하고, 유비쿼터스 서비스를 제공할 수 있도록 다양한 유무선 통신 시스템들이 IP 기반의 멀티네트워크로 통합될 것이다. 이러한 차세대 통신 시스템에서 IP 기반 멀티미디어 응용을 효율적으로 지원하기 위하여 종단간 QoS 제공이 중요한 문제가 된다. 본 고에서는 3세대 이동통신과 차세대 백본 네트워크(NGN)에서 연구되고 있는 QoS 제공 방안을 살펴본다. 그리고, 3세대 이후의 통신 시스템을 위하여 IP 네트워크에 기반을 두고 이질적인 무선 시스템들의 통합에 대해 연구하고 있는 프로젝트에서 All-IP화에 따른 종단간 QoS 제공 방안을 살펴본다. 그리고, 다양한 통신 시스템들이 IP 기반의 백본 네트워크로 통합되어 All-IP화된 차세대 통신 시스템의 개략적 구조를 제시하고, 이를 기반으로 종단간 QoS 제공을 위하여 연구되어야 할 주요 사항들을 살펴본다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.197-198
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• 2007

For provisioning the best effort service, the IEEE 802.16 Wireless MAN standard employs a MAC scheme based on reservation ALOHA. In the MAC scheme, a subscriber station, after attempting a resource request, waits for a resource grant during a prescribed period rather than an explicit acknowledgement. In this paper, we propose a MAC scheme for improving delay performance, where we control the lifetime of a request to prevent excessive grants and distribute residual resource according to a round robin. Simulation results show that the proposed scheme significantly improves the mean delay performance.

• 한국컴퓨터정보학회논문지
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• 제20권10호
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• pp.53-59
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• 2015

In this paper we propose a resource management scheme which allocates hierarchical resources stepwise based on the users' QoS requirement of each service in the macro-femtocell overlaid LTE-Advanced network. Our proposed scheme adjusts the transmission rate to the minimum which guarantees the allowable minimum requirement of delay for each user service. In this way it minimizes the interference on the adjacent channels and it is able to increase the resource utilization efficiency. Simulation results show that our scheme provides better performances than the conventional one in respect of the outage probability and data transmission throughput.

• Journal of Communications and Networks
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• 제8권3호
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• pp.297-305
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• 2006

High-rate wireless personal area network (HR-WPAN) has been standardized by the IEEE 802.15.3 task group (TG). To support multimedia services, the IEEE 802.15.3 TG adopts a time-slotted medium access control (MAC) protocol controlled by a central device. In the time division multiple access (TDMA)-based wireless packet networks, the packet scheduling algorithm plays a key role in quality of service (QoS) provisioning for multimedia services. In this paper, we propose an adaptive cross-layer packet scheduling method for the TDMA-based HR-WPAN. Physical channel conditions, MAC protocol, link layer status, random traffic arrival, and QoS requirement are taken into consideration by the proposed packet scheduling method. Performance evaluations are carried out through extensive simulations and significant performance enhancements are observed. Furthermore, the performance of the proposed scheme remains stable regardless of the variable system parameters such as the number of devices (DEVs) and delay bound.

• 한국통신학회논문지
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• 제37C권10호
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• pp.888-893
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• 2012

Quality of Service (QoS) provisioning is an important issue in the design of next generation wireless network. In visible light communication (VLC) networks, link switching is a solution to maintain or improve the quality of communication. In this paper, we propose a novel link switching scheme using the location of mobile nodes (MNs). The current serving transmitter uses location history of the MN to find out which neighbor transmitter the MN is approaching. This neighbor transmitter is chosen to inform the MN as the next serving transmitter. The simulation results show that our proposed scheme gains better performance than non-predictive link switching scheme.

• 한국통신학회논문지
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• 제33권5B호
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• pp.334-343
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• 2008

In this work we propose a universal pricing machine, which incorporates a universal pricing framework for the future IEEE802.16 WiMAX service with multiple classes of service. A multimedia service is provided by a QoS provisioning scheme in the WiMAX network and universal pricing means that it can compute the price for any type of service in a unified framework. In the proposed pricing framework we incorporate multiple types of services such as the real time and nonreal time services that are supposed to be provided in the WiMAX network. To that purpose, let us first carry out an analysis on the current pricing scheme of Korean WiMAX service which incorporates only the data size. From that analysis we propose a new pricing scheme for the future WiMAX service that provides different service classes in the network. Via numerical experiment, we verify the implication of the work.