• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.5 no.3
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• pp.110-116
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• 2012

As rapid development of the Internet, there are increasing interests about quality of service of VoIP using the Internet network and established PSTN. There was some study going on to improve the quality of service from the point of view of supplier's mainly. However recently, the demand for setting up the objective standards that service provider can offer to customers is needed as the interests from customers has been going up. In this study, we analysed the results from the test using PESQ which is a parameter of quality of service. we offer the conditions of network which guarantees the minimum quality of phone call using VoIP.

• Journal of the Korea Society of Computer and Information
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• v.12 no.6
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• pp.1-9
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• 2007

We propose a novel framework for distributed resource management. The framework has the following novel features. First, the resource management system is distributed using resource content information that is characterized by system properties. We argue that a distributed system based on resource content is sufficient to satisfy specific scheduling requests for Quality of Service(QoS) considering workload balance across a grid. Second, the distributed system constructs a hierarchical peer-to-peer network. This peered network provides an efficient message routing mechanism. The simulation results demonstrate that the proposed framework is proficient to satisfy QoS in distributed environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.10B
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• pp.613-620
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• 2007

Recently, due to the developing of broadband convergence networks, the high quality multimedia services which are converged with communication and broadcasting can be provided. These high quality communication and broadcasting convergence service needs reliable multicasting mechanism in IP networks. However, multicasting mechanism recently deployed is difficult to guarantee the end-to-end QoS. For the reliable high quality If multimedia IPTV service, the QoS guaranteed multicasting mechanism should be provided. Therefore, we proposed a probing packet based multicasting admission control mechanism using centralized multicasting control management block in this paper. And for the performance evaluation of the proposed mechanism, we used ns-2 simulator.

• Journal of Communications and Networks
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• v.11 no.3
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• pp.297-305
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• 2009

Multiprotocol label switching (MPLS) networks require dynamic flow admission control to guarantee end-to-end quality of service (QoS) for each Internet protocol (IP) traffic flow. In this paper, we propose to tackle the joint routing and admission control problem for the IP traffic flows in MPLS networks without rerouting already admitted flows. We propose two mathematical programming models for this problem. The first model includes end-to-end delay constraints and the second one, end-to-end packet loss constraints. These end-to-end QoS constraints are imposed not only for the new traffic flow, but also for all already admitted flows in the network. The objective function of both models is to minimize the end-to-end delay for the new flow. Numerical results show that considering end-to-end delay (or packet loss) constraints for all flows has a small impact on the flow blocking rate. Moreover, we reduces significantly the mean end-to-end delay (or the mean packet loss rate) and the proposed approach is able to make its decision within 250 msec.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.4
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• pp.657-662
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• 2019

The power consumption of wearable sensors and electrocardiogram regulators should be very low to extend the network lifetime and anticipated QoS( : Quality of Service) control such as error correction and authentication of data processed by WBAN( : Wireless Body Area Network) nodes is important. Therefore, QoS control is the most urgent concern to implement WBAN in health monitoring regulations. For optimal QoS control, we compare the energy efficiency and the average number of transmissions with IEEE 802.15.6 and the error correction method considering energy efficiency. The performance of the proposed error correction technique shows that the energy efficiency and the transmission rate are improved by adjusting the coding rate appropriately using the channel estimation.

• ETRI Journal
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• v.45 no.5
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• pp.887-898
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• 2023

Aerial base stations (ABSs) seem promising to enhance the coverage and capacity of fifth-generation and upcoming networks. With the flexible mobility of ABSs, they can be positioned in air to maximize the number of users served with a guaranteed quality of service (QoS). However, ABSs may be overloaded or underutilized given inefficient placement, and user association has not been well addressed. Hence, we propose a three-dimensional ABS placement scheme with a delay-QoS-driven user association to balance loading among ABSs. First, a load balancing utility function is designed based on proportional fairness. Then, an optimization problem for joint ABS placement and user association is formulated to maximize the utility function subject to statistical delay QoS requirements and ABS collision avoidance constraints. To solve this problem, we introduce an efficient modified gray wolf optimizer for ABS placement with a greedy user association strategy. Simulation results demonstrate that the proposed scheme outperforms baselines in terms of load balancing and delay QoS provisioning.

• Journal of Communications and Networks
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• v.13 no.3
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• pp.286-297
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• 2011

A novel converged optical network unit (ONU)-base station (BS) architecture has been contemplated for next-generation optical-wireless networks. It has been demonstrated through high quality studies that data traffic carried by both wired and wireless networks exhibit self-similar and long range dependent characteristics; attributes that classical teletraffic theory based on simplistic Poisson models fail to capture. Therefore, in order to apprehend the proposed converged architecture and to reinforce the provisioning of tightly bound quality of service (QoS) parameters to end-users, we substantiate the analysis of the QoS behavior of the ONU-BS under self-similar and long range dependent traffic conditions using custom queuing which is a common queuing discipline. This paper extends our previous work on priority queuing and brings novelty in terms of presenting performance analysis of the converged ONU-BS under realistic traffic load conditions. Further, the presented analysis can be used as a network planning and optimization tool to select the most robust and appropriate queuing discipline for the ONU-BS relevant to the QoS requirements of different applications.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.6B
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• pp.1113-1122
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• 1999

In this paper, we propose MSS(Multicast Synchronization Server) and QCS(QoS Conversion Server) models that can support IP multicast and QoS(Quality of Service) over the ATM network more efficiently. In the MSS model, it is possible to establish shortcut VCs(Virtual Circuits) among all hosts in the ATM network and to transfer multicast data at high speed. Also the MSS model is more scalable, because the number of inter-cluster VCs needed in the MSS model is less than that of EARTH. In the QCS model, ATM switch is modified to support one QoS service and best effort service through the one point-to-multipoint VC at the same time so required network resources are reduced, and dedicated server is used for QoS conversion to accept heterogeneous receivers more efficiently. In this Paper, the proposed MSS model and QCS model have solved both efficiency problem and scalability problem. It is proved through the comparison of the VCs required in each model.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2002.11a
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• pp.352-355
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• 2002

QoSS(Quality of Security Service)는 보안을 단순한 성능 장애 요소의 관점에서 벗어나 QoS(Quality of Service)의 관점에서 효율적인 네트워크 관리 도구로서 사용하기 위해 등장한 개념이다. QoSS는 보안 서비스들이 적용되는 상황에 따라, 또는 사용자의 요구사항에 따라 다양한 수준으로 제공 가능하다는 가변 보안의 개념에 기초하고 있다. 이를 통해 사용자에게는 제공되는 서비스들에 대한 만족도를 향상시키고, 서비스 제공자 측면에서는 자원의 가용성을 향상시키는 효과를 달성 할 수 있다. 본 논문에서는 이러한 QoSS의 전반적인 구성 요소들을 간략히 소개하고, 차세대 네트워크 보안 서비스의 구축 시 QoSS의 적응 절차와 적용 시 고려해야 할 사항에 대해서 제안한다.

• Proceedings of the Korea Multimedia Society Conference
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• 2000.11a
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• pp.41-44
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• 2000

분산 멀티미디어 시스템은 이식성을 보장하고 동적인 자원 변화를 수용하고 올바른 시간에 올바른 데이터 인도를 보장해야 한다. 따라서 분산 멀티미디어 시스템의 각 구성 요소들은 멀티미디어 응용에서 QoS(Quality of Service)를 제공하기 위한 자원 관리 기법과 다양한 종류의 QoS 요구를 수용할 수 있어야 한다. 본 연구에서 가변 전송율을 갖는 비디오에 대한 여러 종류의 QoS 요구를 만족하기 위한 비디오 배치 및 검색 방법을 제안한다. 제안된 방법은 여러 종류의 해상도 요구에서 개선된 성능을 보였다.