• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.53-54
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• 2006

In this paper, we analytically evaluate packet delay and energy consumption of S-MAC protocol with a modified Markov chain model. Although some models, based on IEEE 802.11 MAC protocol, to analyze the S-MAC protocol in wireless sensor network (WSN) have been proposed, they fail to consider the differences in architecture between the S-MAC and the 802.11 MAC. Therefore, by reflecting the significant features in the S-MAC function, we model the operation of S-MAC protocol, and derive its packet delay and energy consumption in single-hop WSN. Numerical results show the delay and the dissipated energy at various duty cycle values according to offered load, where a practical mote is used.

• Journal of Information Processing Systems
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• v.7 no.1
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• pp.137-150
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• 2011

Mobile ad hoc networks are expected to be widely used in the near future. However, they are susceptible to various security threats because of their inherent characteristics. Malicious flooding attacks are one of the fatal attacks on mobile ad hoc networks. These attacks can severely clog an entire network, as a result of clogging the victim node. If collaborative multiple attacks are conducted, it becomes more difficult to prevent. To defend against these attacks, we propose a novel defense mechanism in mobile ad hoc networks. The proposed scheme enhances the amount of legitimate packet processing at each node. The simulation results show that the proposed scheme also improves the end-to-end packet delivery ratio.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.7
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• pp.41-46
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• 2004

Two multicast delivery schemes are proposed to minimize the packet loss that occurs in the mobile multicast (MoM) protocol due to the handoff and relocation. The proposed schemes use a primary designated multicast service provider (DMSP) and a redundant or non-redundant backup DMSP. The simulation results verify that the proposed schemes greatly reduce the packet loss rate at the expense of the increased network traffic or the extra protocol overhead related to the operation of the non-redundant backup DMSP.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.05a
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• pp.1-4
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• 2005

Information communication environment integrates communication, broadcasting and internet, and Digital Convergence service emerges in result. Thus, the effective routers are needed so that they can transmit a huge number of data to core internet through appropriate base center. Therefore, the network guaranteeing QoS in transport layer supports interoperability with different wireless networks. So as to users receive necessary information anywhere seamlessly, the network architecture focuses on packet transmission and it is efficient for the control layer switches and controls packets between different networks. Since individual users take advantage of different services and data, the effective router architecture must be designed. Hence in this paper we design monitoring technique to solve security problem and to support premium service to ultimate users. Thereafter, we run opnet simulation and show the improvement of proposed router architecture.

• Journal of Communications and Networks
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• v.18 no.1
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• pp.105-111
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• 2016

Trust models in the literature of MANETs commonly assume that packets have different security requirements. Before a node forwards a packet, if the recipient's trust level does not meet the packet's requirement level, then the recipient must perform certain security association procedures, such as re-authentication. We present in this paper an analysis of the epidemic broadcast delay in such context. The network, mobility and trust models presented in this paper are quite generic and allow us to obtain the delay component induced only by the security associations along a path. Numerical results obtained by simulations also confirm the accuracy of the analysis. In particular, we can observe from both simulation's and analysis results that, for large and sparsely connected networks, the delay caused by security associations is very small compared to the total delay of a packet. This also means that parameters like network density and nodes' velocity, rather than any trust model parameter, have more impact on the overall delay.

• IE interfaces
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• v.13 no.4
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• pp.709-716
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• 2000

In this paper, We analyze a capacity dimensioning and performance of the access line to the X.25 packet network when the AO/DI internet service is connected via D-channel. We show the forecasting methodology of the traffic demand of the D-channel internet services when the TDX-1OA switching system accommodates the target number of subscriber. Based on the traffic demand forecast, the required capacity of the access line is suggested to prevent bottleneck problem in the access line to the X.25 packet network.

• Journal of information and communication convergence engineering
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• v.3 no.2
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• pp.90-92
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• 2005

As the result of the study shows, Round Robin Algorithm allows servers to ensure definite traffic distribution, unless incoming data loads differ much. Although error levels are high in some cases, they were eventually alleviated by repeated tests for a long period of time. The study uses two software packages (Packet Capture and Round Robin Test Package) to check packet volume from Virtual Network Structure (data generator, virtual server, Server 1, 2, 3), and finds out traffic distribution toward Server 1, 2, and 3. The functions of implemented Round Robin Load Balancing Monitoring System include round robin testing, system monitoring, and graphical indication of data transmission and packet volume.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.287-289
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• 2013

Fast Handover for Proxy Mobile IPv6 (FPMIPv6), a protocol described in RFC 5949, is used to reduce handover latency and minimize packet loss problem occuring in the Proxy Mobile IPv6 (PMIPv6) protocol. However, during the study of implementing FPMIPv6, we found the Out-of-Order Packet (OoOP) problem that occurs in the experiment of FPMIPv6. Since the OoOP is an issue that affects significantly to QoS of the network, in this paper, we analyze the OoOP problem by using network model. The analysis conducts the cause of occurring OoOP problem due to there exist two paths for data transmitted from Correspondent Node (CN) to MN in FPMIPv6.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.3B
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• pp.143-152
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• 2007

In order to provide new value-added services such as a policy-based routing and the quality of services in next generation network, the Internet routers need to classify packets into flows for different treatments, and it is called a packet classification. Since the packet classification should be performed in wire-speed for every packet incoming in several hundred giga-bits per second, the packet classification becomes a bottleneck in the Internet routers. Therefore, high speed packet classification algorithms are required. In this paper, we propose an efficient packet classification architecture based on a hierarchical binary search fee. The proposed architecture hierarchically connects the binary search tree which does not have empty nodes, and hence the proposed architecture reduces the memory requirement and improves the search performance.

• Journal of KIISE:Information Networking
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• v.28 no.4
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• pp.602-610
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• 2001

In the MPLS(Multiprotocol Label Switching) forwarding paradigm, once a packet is assigned to a FEC(Forwarding Equivalence Class), no further header analysis is done by subsequent routers; all forwarding is driven by the labels. This has a number of advantages over conventional network layer forwarding. The MPLS LER(Label Edge Router) is located at the boundary of MPLS domain and plays a role in connecting with the existing Internet as an ingress or an egress router. That is, the MPLS LER as an ingress router assigns a label to a packet which enters the MPLS network from the Internet by analyzing its header and forwards to a corresponding next router in MPLS domain. As an egress router, the MPLS LER turns the packets out of the MPLS network by performing the reverse operation. In this paper, we analyze the traffic performance of an MPLS LER system and estimate the IP(Internet Protocol) packet processing capacity of the system using queueing model and simulation. It is found that the maximum IP packet processing capacity of the system is estimated by 420,000 through 460,000 packets/sec.