• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6A
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• pp.666-676
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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 005 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.

• Journal of the Korea Society of Computer and Information
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• v.10 no.5 s.37
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• pp.187-198
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• 2005

In this paper, we propose the enhanced header compression scheme for the efficient data traffic transmission in Ipv6 networks. The bandwidth of wireless links and IP networks will probably be limited due to properties of the physical medium and regulatory limits on the use of frequencies for radio communications. That is major cause of user throughput reduction. Therefore, We discuss the IPHC(RFC2507) and ROHC(RFC3095) scheme. IPHC is simple header compression scheme and ROHC is enhanced header compression that have fast optimal recovery scheme. We have studied the enhanced header compression scheme in ROHC. We will show that indication of compression context values preventing from packet losses can provide the fast recovery of compression state. Computer simulations show that the proposed scheme has better performance than the previous one.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2003.05a
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• pp.8-13
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• 2003

Historically, IP-based internets have been able to provide a simple best-effort delivery service to all applications they carry. Best effort treats all packets equally, with no service level, packet loss, and delay. But the needs of users have changed. The want to use the new real-time, multimedia, and multicasting applications. Thus, there is a strong need to be able to support a variety of traffic with a variety of quality-of-service requirements. The DiffServ architecture, proposed by the Internet Engineering Task Force(IETF), has become the most viable solution for provising QoS over IP networks. The DiffServ architecture does not specify any handling method between AF out-profile packets and BE packets. This paper propose a mechanism for supporting inter class fairness in the DiffServ architecture. Ⅰ proposed a modified Weighted Round Robin method to protect the BE traffic from AF out-profile packets in the core routers. The proposed technique is evaluated through simulation. Simulation results indicate that the proposed method provides better protection not only for BE packets from AF out-profile packets, but also for the AF in-profile packets in congested networks.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.111-119
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• 2010

With the rapid progress of wireless technologies today, mobile terminals with multiple access interfaces are emerging. In recent years, WLAN (Wireless Local Area Networks) has become the premier choice for many homes and enterprises. WiMAX (Worldwide Interoperability for Microwave Access) has also emerged as the wireless standard that aims to deliver data over long distances. Therefore, it is important to explore efficient integration methods for delivering multimedia data between heterogeneous wireless networks. In this paper, we developed the simulation models and environments for the mobile multihomed node that has both WiMAX and WLAN interfaces and can move around in both networks by using mobile IP. In order to verify the developed models, we designed and constructed several simulation scenarios, e.g. movement in WiMAX/WLAN, group mobility, MANET, and nested MIP under the various traffic environments such as oneway or bothway UDP packets, FTP traffic, and voice with SIP protocol. The simulation results show that the developed models are useful for mobility studies in various integrated wireless networks.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.6
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• pp.49-57
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• 2010

In the near future IPTV services will be emerged the various types through Internet, but IMS based IPTV service is one of the very attractive IPTV services. This paper describes the interconnecting architectures of Web based IPTV contents provider to IMS(IP Multimedia System) network and describes the three difference architectures as method to find its IP address. One is the architecture using DNS or HSS to find IP address of Web based IPTV contents provider and connecting gateway function to I-CSCF in IMS. The other is the architecture connecting gateway AS to ISC interface of S-CSCF in IMS. This paper describes the characteristics of traffic generating due to interconnect the Web contents provider, and the traffic model of each architectures. The proposed each architecture is emulated the session establishment delay characteristics in CoD service of IPTV by the simulation. This paper shows that the architecture connecting gateway AS to ISC interface of S-CSCF is the excellent method compare to other two methods in view of the session establishment delay.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.3
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• pp.107-117
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• 2009

Network administrator recognizes the abnormal phenomenon in the managed network by using the alert messages generated in the security devices including the intrusion detection system, intrusion prevention system, firewall, and etc. And then the series of task, which searches for the traffic related to the alert message and analyzes the traffic data, are required to determine where the abnormal phenomenon is the real network security threat or not. There are many alert messages to have to inspect in order to determine the network security situation. Also the much times are needed so that the network administrator can analyze the security condition using existing methods. Therefore, in this paper, we proposed an efficient method for analyzing network security situation using visualization. The proposed method monitors anomalies occurred in the entire IP address's space and displays the detail information of a security event. In addition, it represents the physical locations of the attackers or victims by linking GIS information and IP address. Therefore, it is helpful for network administrator to rapidly analyze the security status of managed network.

• The KIPS Transactions:PartC
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• v.8C no.5
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• pp.637-646
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• 2001

The multicasting telecommunication is an important research as an applicable technique in the development of adaptable technique for modern mobile computing and mobile IP, because that is supposed to be a solution for transferring the large-size information on the mobile and wireless network with the narrow bandwidth. This paper will suggest one solution for the bidirectional tunneling and the local re-registration problems to support transferring mobile multicasting datagram by the partitioned network. The bidirectional tunneling technique is in use for mobile host moving around in a region and the local re-registration technique for crossing regions to reduce traffic load caused by transferring datagram along a long distance, and we compare those models with our suggested model by simulation.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.8
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• pp.19-29
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• 2001

The recent explosion in the Internet applications, Internet. host number and the traffic in the IP backbone network is posing new challenges for transport network. This requires a high-speed IP backbone network that has a substantially higher bandwidth than the one offered by current networks, which prompts the development of all-optical network. To obtain optical network utilization gains, we need a software which establishs logical topology to make possible the efficient use or physical topology, and control the optical network in combination with the IP layer routing protocols. Finally, the logical topology is required higher efficient than physical topology. For this an efficient algorithm for the routing and wavelength assignment(RWA) in the WDM all-optical network is necessary. In this paper, two kinds of heuristic algorithms to establish logical topology for WDM networks and arc applied to the design of logical topology of domestic backbone network. These algorithms are found to work quite well and they arc compared with each other in terms of blocking rate, etc.

• KIPS Transactions on Computer and Communication Systems
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• v.1 no.3
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• pp.205-218
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• 2012

Mobility management of the mobile nodes and provision of seamless handover is crucial to an efficient support for the global roaming of the mobile nodes in next-generation wireless networks. Mobile IPv6 and mobility management in extended IP layer, which highly depend on traffic characteristics and user mobility models, were proposed by the IETF. Therefore, to evaluate the in-depth performance about these factors is important. Generally, the performance of IPv6-based mobility management protocol is evaluated through simulation. This paper shows the correlation between network parameters and performance metrics through numerical results, which is investigated how influence handoff latency and packet loss. And this paper uses mathematical analysis of the system parameters, such as the subnet residence time, the packet arrival rate and delay in wireless connection through the analytical framework which evaluate the performance of IPv6-based mobility management protocol.