• The KIPS Transactions:PartC
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• v.11C no.4
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• pp.429-438
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• 2004

This Paper Presents the control structure for incoming traffic from arbitrary node to Provide admission control in policy-based W network management structure using fuzzy logic control approach. The proposed control structure uses scheme for deciding network resource allocation depending on requirements predefined-policies and network states. The proposed scheme enhances policy adapting methods of existing binary methods, and can use resource of network more effectively to provide adaptive admission control, according to the unpredictable network states for predefined QoS policies. Simulation results show that the proposed controller improves the ratio of packet rejection up to 26%, because it Performs the soft adaption based on the network states instead of accept/reject action in conventional CAC(Connection Admission Controller).

• Journal of KIISE:Information Networking
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• v.33 no.3
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• pp.247-256
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• 2006

Among the resource provisioning mechanisms for the hose based Virtual Private Network (VPN) Quality of Service (QoS ), VPN-specific state provisioning allows the service provider to obtain highest resource multiplexing gains. However, dynamic and automatic resource reservation for the VPN-specific state provisioning is difficult due to the lack of appropriate resource reservation protocol. Furthermore, users of a VPN may experience unfair usage of resources among themselves since the reserved resources of a VPN are shared by the VPN users in a similar way that the traditional LAN bandwidth is shared by the attached hosts. In this paper, we propose a resource reservation protocol and a traffic service mechanism, which not only enable dynamic and automatic resource reservation according to the VPN-specific state provisioning algorithm, but also enforce the fair usage of reserved resources among the users of a VPN in case of congestion.

• Journal of Digital Convergence
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• v.12 no.8
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• pp.249-255
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• 2014

In this paper, we proposed to reduce the interference in the visible light Communication with multi-LEDs for improving the performance of BER and satisfied the QoS. LED is not only lighting device, but also transmitting device in the VLC. Our proposed system is aim to decrease the interference in the multi-LEDs. In addition, it occurred the ISI and CCI by transmitter to receiver different distance. To solve this problem, we proposed the multi-LEDs system using walsh code to reduce ISI and CCI. In addition, our proposed system is able to improve the performance of BER and satisfied the Qos to desire users.

• Journal of Korea Multimedia Society
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• v.12 no.9
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• pp.1201-1209
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• 2009

Recently, the convergence of the telecommunications industry through the development of network media has brought along interactive data services in addition to the traditional broadcast services by providing direct connections between the users and the broadcasters. This can be easily achieved by the combination of existing network technology and multimedia technology, but in reality, as seen in the actual implementation of IPVT, it's difficult to provide satisfactory levels of service to users due to issues of network bandwidth and problems of streaming system. In particular, a network which is able to fully support Qos/QoE, and also a fast enough channel changing technology that is satisfactory to the user, are prerequisites for IPTV success. Therefore this thesis proposes a fast channel changing technique to delivery enhanced IPTV user experience. Recent IP set-top-boxes use only a small portion of the CPU to feed Ethernet packets to the hardware decoder and play them. Thus, by making IP set-top-boxes share cached channel information and content with each other, reducing the load on the server and enhancing the channel changing time is made possible.

• Journal of Korea Multimedia Society
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• v.11 no.3
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• pp.341-352
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• 2008

The dedicated line linked up with the internet maintains generally the efficiency of network by using Best Effort Model. But it is the problem that we allocate the higher bandwidth to services which request high bandwidth regardless of service types or purposes. To overcome this weak point, we use the Session QoS System which distinguish between business services such as E-mail, Web, etc. and non-business services. But, a recent session QoS system is not adequate to the environment similar to university, because that has many users who have various requests. In this paper, to satisfy various requirements of many user's in session QoS system which support services of research, education, business, etc., we analyze types of service in the environment of education and research network and propose a necessity of management strategies of session Qos system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.2
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• pp.228-238
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• 2003

We believe that existing wire solutions such as HomePNA2.0 using phone lines and HomePlug using power line and wireless solution such as HomeRF are the most promising solutions, because of its cost-effectiveness. However, MAC protocols of these solutions provide only Class of Service(CoS) using priority mechanism like HomePNA and HomePlug or consider only voice among real-time traffics like HomeRF. For these reasons, we perceive the needs of the new MAC protocol which is no new wire solution and provides guaranteed Quality of Service (QoS) for not only voice but also video and audio. In light of this, we present the design and software implementation of a new MAC protocol for Home Networks. Our evaluation results of software implementation verify that proposed MAC protocol can provide low delay, low loss, and low jitter to real-time traffic by reserving bandwidth.

• Journal of information and communication convergence engineering
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• v.8 no.1
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• pp.1-5
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• 2010

In this paper, we propose for improving QoS in wireless micro cellular network using Cellular-IP/PRC(Paging Route Cache) with Paging Cache and Route Cache in Cellular-IP and propose for performance of realtime and non-real time handoff service using Handoff state machine Paging Route Cache. Although the Cellular-IP/PRC technology is devised for mobile internet communication, it bas its vulnerability in frequent handoff environment. On the other hand, Cellular IP combines the capability of cellular networks to provide high performance handoff and efficient location management of active and idle mobile users with the inherent flexibility, robustness and scalability found in IP networks. Also Cellular-IP/PRC use semi-soft handoff. During semi-soft hand off a mobile host may be in contact with either of the old and new base stations and receive packets from them. Packets intended to the mobile node are sent to both base stations and buffered, so when the mobile host eventually moves to the new location it can continue to receive packets without interruption. It should be suitable for realtime service such as multimedia traffic. But, much waste of resource will occur in this method, especially for non-real time services such as FTP and E-mail. Therefore, a new algorithm that performs different handoff according to characteristic of each traffic by use of reserved field in IP packet is proposed in this thesis. This hand off state machine using differentiated handoff improves quality of services in Cellular-IP/PRC. Suggested algorithm shows better performance than existing technology in wireless mobile internet communication environment. Matlab simulation results are improving QoS, show call drop and call blocking provided to Paging Router Cache during handoff state machine in Cellular-IP/PRC.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.5
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• pp.155-162
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• 2014

We proposed a 2 level tree based cluster based routing protocol for mobile ad hoc networks. it is our crucial goal to establish improved clustering's structure in order to extend average node life-time and elevate the average packet delivery ratio. Because of insufficient wireless resources and energy, the method to form and manage clusters is useful for increasing network stability. but cluster-head fulfills roles as a host and a router in clustering protocol of Ad hoc networks environment. Therefore energy exhaustion of cluster-head causes communication interruption phenomenon. Effective management of cluster-head is key-point which determines the entire network performance. The scheme focuses on improving the performance the life time of the network and throughput through the management of cluster-heads and its neighbor nodes. In simulation, we demonstrated that it would obtain averagely better 17% performance than LS2RP.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.10
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• pp.722-733
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• 2006

In scalable streaming application, there are two important knobs to tune to effectively exploit the underlying network resource and to maximize the user perceivable quality of service(QoS): layer selection and packet scheduling. In this work, we propose Semantics Aware Packet Scheduling (SAPS) algorithm to address these issues. Using packet dependency graph, SAPS algorithm selects a layer to maximize QoS. We aim at minimizing distortion in selecting layers. In inter-frame coded video streaming, minimizing packet loss does not imply maximizing QoS. In determining the packet transmission schedule, we exploit the fact that significance of each packet loss is different dependent upon its frame type and the position within group of picture(GOP). In SAPS algorithm, each packet is assigned a weight called QoS Impact Factor Transmission schedule is derived based upon weighted smoothing. In simulation experiment, we observed that QOS actually improves when packet loss becomes worse. The simulation results show that the SAPS not only maximizes user perceivable QoS but also minimizes resource requirements.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6A
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• pp.667-667
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• 2004

We must design the buffer algorithm that protects traffic congestion and decreasing throughput at satellite communication network. It is important that buffer algorithm is satisfied with the good performance of transmission packet, responsibility of many connecting traffic and the QOS for connecting character. Old buffer algorithms are not the suitable algorithms when we have the satellite communication network environment. RED buffer algorithm is proposed by Floyd. It has a better performance than old buffer algorithm. But this algorithm is not well adapted a number of connecting TCP packet and changing network, so this algorithm has a bad performance on satellite communication network that is many of connecting user at same time. This paper propose the TARED(Target Adaptive RED). It has a good performance, adaptation and stability on satellite communication network and has not overflow and underflow of the buffer level.