• The Journal of the Korea Contents Association
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• v.4 no.4
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• pp.197-203
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• 2004

In mobile network, the maintenance o( host grouping or the multicast delivery tree for multicasting algorithm becomes a major issues. In this paper, we explore the issues of mobile Multicast scheme using Mobile-IPv6, and addresses case when a mobile host is a source as well as a recipient of a given multicast operation using MLD(Multicast Listener Discovery) scheme, and the proposed MLD-based multicasting protocol asks its HA(Home Agent) to stop forwarding multicast for group using tunneling. We examine and compare our model to existing approaches by proposed cost model, and observe an improved ferformacne.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.8
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• pp.1083-1093
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• 1993

Recently, some applications require the multicast service that transmit messages to multiple destinations in computer communication network enviroment. Multicast service is to send messages to the group which consists of a number of processes. A multicast group is a collection of processes which are destinations of the transmitted messages and these processes may run on one or more hosts. Therefore, it is important to manage each member of process groups in order to provide efficient multicast services. In this paper, we design and implement group management system to support multicast services. Group Management System was designed with Process Group Management System(PGMS) and Host Group Management System(HGMS). We have implemented basic primitives of PGMS, HGMS. Also, membership tree management algorithm is designed and implemented. Membership tree provides the relation of the members of multicast groups and routing Informations.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.120-127
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• 2002

The multicasting is defined as the distribution of the same information stream from one to many nodes concurrently. There has been an intensive research effort to design protocols and construct multicast routing graphs for a single multicast group. However. there have been few researches about the relation between multiple and concurrent multicast groups. In this paper, the multiple multicast tree allocation algorithm to avoid congestion is proposed. The multicast group with different bandwidth requirement is also considered. A two-phase algorithm is proposed. The first phase is for basic search and the second phase for further improvement. The performance of the proposed algorithm is experimented with computational results. Computational results show that the proposed algorithm outperforms an existing algorithm.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.1367-1369
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• 2013

Applying Application-Level Multicast technology (ALM) to Distributed Interactive Applications (DIAs) becomes more and more popular. Especially for DIAs embedded priority that the sender forwards data to receivers due to their respective priorities. The priority-based directed minimum spanning tree (PST) algorithm was designed for these DIAs. However, the PST has no efficient priority selection and filtering mechanism. The system will consume a tremendous amount of resource for reconstructing distribution tree and becomes unstable and unscalable. In this paper, First, We propose a novel priority-based application level multicast algorithm: Predict-and-Quantize for Priority with directed minimum Spanning Tree (PQPST), which can efficiently predict efficient priorities for the receivers and quantize the predicted priorities to build the multicast distribution tree. Second, we propose Priority Discrepancy Heuristic Mechanism (PDHM), which sets different thresholds of priority discrepancy within the priority discrepancy interval to control the distribution tree construction can efficiently decrease the repeated distribution tree construction, and we get the best heuristic priority discrepancy interval by PQPST. According to the simulation results, the PQPST and PDHM can efficiently improve the performance of the PST algorithm.

• Journal of KIISE:Information Networking
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• v.30 no.3
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• pp.424-436
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• 2003

In this paper, we propose the Centroid-based Backbone Core Tree(CBCT) generation algorithm for the shared tree-based IP multicasting. The proposed algorithm is based on the Core Based Tree(CBT) protocol. Despite the advantages over the source-based trees in terms of scalability, the CBT protocol still has the following limitations; first, the optimal core router selection is very difficult, and second, the multicast traffic is concentrated near a core router. The Backbone Core Tree(BCT) protocol, as an extension of the CBT protocol has been proposed to overcome these limitations of the CBT Instead of selecting a specific core router for each multicast group, the BCT protocol forms a backbone network of candidate core routers which cooperate with one another to make multicast trees. However, the BCT protocol has not mentioned the way of selecting candidate core routers and how to connect them. The proposed CBCT generation algorithm employs the concepts of the minimum spanning tree and the centroid. For the performance evaluation of the proposed algorithm, we showed the performance comparison results for both of the CBT and CBCT protocols.

• The Journal of the Korea Contents Association
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• v.8 no.7
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• pp.58-65
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• 2008

The overlay multicast that has been recently presented as an alternative for the IP multicast has been getting much attention by the advancement of network techniques to enforce routing in application-levels. In this paper, we verified the efficiency of Internet broadcasting through comparing latency time of TBCP with mOBCP that have distributed Tree-first based spanning-tree structures in overlay multicast techniques. We also propose effective tree structures that minimize latency time and provide competent service by choosing optimum parent nodes early in the base of these two methods over the same time slot in multi-user connection. The results of our comparison showed that average latency time in mOBCP techniques declined by 36% from those of TBCP technique.

• The KIPS Transactions:PartC
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• v.10C no.7
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• pp.885-890
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• 2003

The Core Base Tree (CBT) multicast routing architecture is a multicast routing protocol for the internet. The CBT establishes a single shared tree for a multicast connection. The shared tree Is rooted at a center node called core. The location of the core may affect the cost and performance of the CBT. The core placement method requires the knowledge of the network topology In this Paper, we propose a simple and effective method for selecting the core. This method requires the distance vector information. in addition, we used results that calculated sample correlation coefficient. And then we select suitable routing algorithm according to member's arrangement states in muliticast group. we select core node that have minimum average cost or PIM-SM protocol is selected. The performance of this method is compared with several other methods by extensive simulations (i.e mean delay, maximum delay, and total cost). Our results shows that this method for Selecting Core is very effective.

• Journal of Communications and Networks
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• v.4 no.3
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• pp.246-255
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• 2002

Constrained minimum Steiner tree (CMST) problem is a key issue in multicast routing with quality of service (QoS) support. Bounded shortest path algorithm (BSMA) has been recognized as one of the best algorithms for the CMST problem due to its excellent cost performance. This algorithm starts with a minimumdelay tree, and then iteratively uses a
-shortest-path (KSP) algorithm to search for a better path to replace a “superedge” in the existing tree, and consequently reduces the cost of the tree. The major drawback of BSMA is its high time complexity because of the use of the KSP algorithm. For this reason, we investigate in this paper the possibility of more efficient implementations of BSMA by using different methods to locate the target path for replacing a superedge. Our experimental results indicate that our methods can significantly reduce the time complexity of BSMA without deteriorating the cost performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.2C
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• pp.139-147
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• 2006

This paper presents an overlay video multicast system over the Internet. The proposed system consists of two parts, i.e. overlay multicast tree suitable for the real-time video delivery and H.263+ rate control adaptive to overlay multicast tree. Overlay multicast tree is constructed to minimize the average time delay of members, and H.263+ rate control pursues a tradeoff between spatial and temporal qualities to enhance the human visual perceptual quality. Two systems are integrated and tested over the real Internet. And experimental results are provided to show the performance of the proposed system.

• The Transactions of the Korea Information Processing Society
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• v.6 no.9
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• pp.2332-2342
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• 1999

Multicast is an important system-level one-to-many collective communication service. A key issue in designing software multicast algorithms is to consider the trade-off between performance and portability. Based on the LogP model, the proposed parameterized communication model can more accurately characterize the communication network of parallel platforms, Under the parameterized model, we propose an efficient architecture-independent method. OPT-tree algorithm, to construct optimal multicast trees and also investigate architecture-dependent tuning on performance of the multicast algorithm to achieve the truly optimal performance when implemented in real networks. Specifically, OPT-mesh which is the optimized version of the parameterized multicast algorithm for wormhole-switched mesh networks is developed and compared with two other well-known network-dependent algorithms.