• The KIPS Transactions:PartC
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• v.17C no.2
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• pp.189-196
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• 2010

The LEACH does not use flooding method for data transmission and this makes low power consumption. So performance of the WSN is increased. On the other hand, QoS based algorithm which use restricted flooding method in WSN also achieves low power consuming rate by reducing the number of nodes that are participated in routing path selection. But when the data is delivered to the sink node, the LEACH choose a routing path which has a small hop count. And it leads that the performance of the entire network is worse. In the paper we propose a QoS based energy efficient clustering and routing algorithm in WSN. I classify the type of packet with two classes, based on the energy efficiency that is the most important issue in WSN. We provide the differentiated services according to the different type of packet. Simulation results evaluated by the NS-2 show that proposed algorithm extended the network lifetime 2.47 times at average. And each of the case in the class 1 and class 2 data packet, the throughput is improved 312% and 61% each.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.2
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• pp.11-20
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• 1997

It is a recent trend that mobile communications and PCS are intergrated into the broadband network. Broadband mutlimedia traffic will be transported over the integrated network. In this paper, we propose a connection re-routing method for fast inter-switch hadoffs and dynamic resurce reservation scheme, which is based on the proposed re-routing method, for the ATM-based personal communications network. To reduce the delay for re-routing method, for the ATM-based personal communications network. To reduce the delay for re-routing, the proposed re-routing method is to reserve VPI/VCIs for possible inter-swich handoff calls in advance. Our reservation scheme is to statistically reserve the fixed resources for possible inter-switch handoff calls, according to the QoS of the handoff calls. The simmulation reslts show that our proposed scheme satisfies the required QoS of handoff calls and keep the dropping probability of handoff calls lower than other schemes.

• Journal of KIISE:Information Networking
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• v.29 no.1
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• pp.65-76
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• 2002

QoS routing is a routing technique for finding feasible path that satisfies QoS requirements required by application programs. Since QoS routing determines such paths in terms of dynamic network state, it satisfies the requirement of applications and increases the utilization of the network. The overhead is, however, generated by routers to exchange the information of the dynamic state of network. In order to reduce this protocol overhead, a timer based update mechanism is proposed in which router checks the change of the network status periodically and network state information is exchanged if the change is greater than a certain value. Using large update period makes, though, routing performance irresponsive to the parameters which determine the update of the network state of the router. In addition to this, large update period may result in inaccurate network state information at routers and cause resource reservation failure. The resource reservation failure generates additional overhead to cancel the resource reservation of the part of the path. In this paper, we propose mechanisms enhancing the existing network state update policy with respect to these two problems. Performance of the proposed schemes are evaluated through a course of simulation.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.241-244
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• 2004

In recent years, WDM networks have received much attention as the Internet backbone networks because of the explosive growth of the Internet IP-based traffic. The Optical Burst Switching (OBS) has been proposed as an effective optical switching technology in the WDM networks. OBS has the advantages in 1) the high usage rate of the bandwidth, and 2) no necessity of optical buffer. However OBS has the burst-contention problem in the networks. The deflection routing is proposed as one of means to solve this problem. In this paper, we propose a new routing method of using deflection routing. In addition. we propose a QoS/CoS control method using a new routing algorithm. Finally, we show the variety of the proposed methods by computer simulations.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.9
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• pp.1112-1125
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• 1999

최근 들어 멀티미디어를 지원하는 응용들의 서비스 품질 보장과 멀티캐스트 지원에 대한 요구가 증가되고 있으나 기존의 멀티캐스트 프로토콜로는 이러한 요구를 수용할 수 없는 문제가 발생하고 있다. 현재 인터넷에서 사용되고 있는 라우팅 메커니즘은 네트워크 자원 정보나 세션의 QoS 요구사항을 고려하지 않고 단순히 종단간의 연결에만 초점을 맞추고 있기 때문이다. 따라서 본 논문에서는 멀티캐스트 환경에서 서비스 품질보장을 지원하기 위한 새로운 프로토콜, LayeredQoS을 제안한다. 다중의 CP (Central Point)를 채택하고 각각의 CP에 적절한 QoS 레벨을 부여하여 사용함으로써 대역폭의 공유정도를 높일 뿐만 아니라 전체 트리 비용을 감소시켜 궁극적으로 네트워크 처리량이 증가되도록 하였다. 또한 시뮬레이션 방법을 통하여 다른 프로토콜보다 나은 성능을 가지는 것으로 평가하였다.Abstract Many emerging multimedia applications often require a guaranteed quality of service and multicast connection. But the traditional multicast protocol can't meet the needs since the routing mechanisms deployed in today's Internet are focused on connectivity, not on resource availability in the network or QoS requirements of flows. In this paper, we present LayeredQoS, a new QoS-based multicast routing algorithm. We adopt the multiple CPs(Central Points) and allocate QoS-levels for each CP in order to improve the degree of resource sharing and decrease the total tree cost, and then network throughput is increased. The proposed protocol is verified by simulations and it is shown that the performance of LayeredQoS is much better than the existing protocols.

• Journal of the Korea Society of Computer and Information
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• v.12 no.2 s.46
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• pp.189-196
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• 2007

In this paper, we proposed a mobile ad hoc routing protocol based on AODV(Ad hoc On demand Distance Vector) with QoS(Quality of Service) support and evaluated the performance through simulation. The waste of communication resources is reduced by establishing the shortest route suitable to QoS support, considering in advance the usable communication resources at each node. For performance evaluation, we analyzed the average data reception rate, considering the node mobility and the number of best effort/QoS data flows. We found that in the mobile Ad Hoc networks the QoS service for some specific data flows increased the average data reception rate for the QoS data flows.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11C
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• pp.140-147
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• 2001

In this paper, we propose a scheme of calculating resources\` costs for precomputation in QoS routing schemes. This scheme is effective in respect to the g1oba1 network utilization and the balanced use of network resources. We also propose a QoS routing scheme for transit and intra traffic in a large scale of domain-based network. For a domain in the network, the routing scheme first precomputes multiple paths between all pairs of ingress and egress border routers while considering balancing of the expected load and then selects paths with the probability of path selection. We, therefore, expect that the paths are better than any other paths in respect to reserving the network resources on paths. The routing scheme combines inter and intra domain routings seamlessly and uses the same cost calculation scheme. And for analysis of a load balancing cost calculation proposed a simulation is done.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.249-252
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• 2001

This paper focuses on the consideration of not only QoS parameters in wired network, but also QoS parameters in wireless network that supported for the Efficient QoS in the Al1 Service Levels. So, We supposed the "Efficient QoS Model" that guaranteed the QoS parameters "Loss Profile" , "Service Degradation" , "Latency and Jittering" , "Mobility of Mobile User" , "Probability of seamless communication" in wired-wireless networks. And the Method of Efficient QoS support that we supposed consists of "Multicast Routing-RSVP Protocol architecture based on Mobile IP" and "Protocols internetworking model ".

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.71-73
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• 2004

Recently many peoples served multimedia data from Internet. But characteristic of multimedia-object about that effect on weight and transport-time causes Streaming Application is restricted to high-quality-service. This research propose the Quality-of-service(QoS) supporting for Home Gateway that behaving Routing and media platform equipment, using CBQ Scheduling scheme. The QoS Supporting for Multimeda Service that using general Rouging policy is difficult because media platform locate in Home Gateway. Therefore this research propose Routing mechanism to QoS support of media platform located in Gateway using TCP based CBQ Control.

• The KIPS Transactions:PartC
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• v.18C no.5
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• pp.361-368
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• 2011

In this study, we present a method for efficiently aggregating networks state information required to determine feasible paths in transport networks that uses the source routing algorithm for hierarchical QoS routing. It is proposed to transform the full mesh topology whose Service Boundary Line serves as its logical link into the star topology. This is an aggregation method that can be used when there are two or more QoS parameters for the link to be aggregated in an asymmetric network, and it improves the information accuracy of the star topology. For this purpose, the Service Boundary Line's 3 attributes, splitting, joining and integrating, are defined in this study, and they are used to present a topology transformation method. The proposed method is similar to space complexity and time complexity of other known techniques. But simulation results showed that aggregated information accuracy and query response accuracy is more highly than that of other known method.