• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.5
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• pp.99-106
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• 2012

Korea navy has been using the voice-oriented ICS to raise a efficiency of naval ship operation. Recently a multimedia network which are included voice, video and text is under consideration by korean navy. As a basic research to establish the integrated multimedia network of a naval ship, this paper classify the networks in order to apply to an integrated network among the various networks within a naval ship. We also consider the sort and characteristic of the multimedia traffic which is using within the classified networks. To predict the link capacity of switch from number of traffic input source, we suggest a traffic aggregation model. Then we calculate the link capacity of aggregated traffic and analyze a aggregated traffic of Korea major naval ship.

• The Transactions of the Korea Information Processing Society
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• v.6 no.2
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• pp.367-376
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• 1999

A variable bit-rate based video services have much limitation for bandwidth management, since its trarfic has a some variances in frame level. In particular, the bandwidth management for video which has characteristics of VBR traffic such a MPEG video could be more complicated. Also, it is difficult to manage the bandwidth effectively for proving a VCR function from VOD service, since we don't know the traffic variance exactly at that time. In this paper, we proposed the dynamic bandwidth allocation a scheme based on VBR traffic based stored video such as MPEG for interactive video service. This scheme can maximize the given total bandwidth through the prefetch based variable length bandwidth allocation scheme and dynamic bandwidth management scheme for multiple streams. Also, our scheme can be used for a MPEG-based bandwidth allocation scheme, and provides the method that can maximize the utilization of network resource for multiple stream by using a dynamic bandwidth management.

• Convergence Security Journal
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• v.20 no.4
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• pp.81-90
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• 2020

In the real world, new types of attacks or variants are constantly emerging, but attack traffic classification models developed through artificial neural networks and supervised learning do not properly detect new types of attacks that have not been trained. Most of the previous studies overlooked this problem and focused only on improving the structure of their artificial neural networks. As a result, a number of new attacks were frequently classified as normal traffic, and attack traffic classification performance was severly degraded. On the other hand, the softmax function, which outputs the probability that each class is correctly classified in the multi-class classification as a result, also has a significant impact on the classification performance because it fails to calculate the softmax score properly for a new type of attack traffic that has not been trained. In this paper, based on this characteristic of softmax function, we propose an efficient method to improve the classification performance against new types of attacks by classifying traffic with a probability below a certain level as attacks, and demonstrate the efficiency of our approach through experiments.

• Journal of Korea Society of Industrial Information Systems
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• v.6 no.3
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• pp.20-28
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• 2001

In this paper, we present an efficient path-based multicast algorithm in wormhole-routed mesh networks. Our algorithm is based on a network partitioning strategy that uses two Hamiltonian paths. In the previous studies, only on a network partitioning strategy that uses two Hamiltonian paths. In the previous studies, only one Hamiltonian path was used. Thus messages traverse mire horizontal channels than vertical ones, leading to earlier network congestion. By incorporating additional vertical Hamiltonian path as well as the horizontal Hamiltonian path, messages are distributed evenly as much as possible, thus making network evenly as much as possible, thus making network performance better. We prove that this algorithm is deadlock-free. And by extensive simulations, we show that this algorithm is superior to the previous ones by 15∼20%.

• Journal of Digital Contents Society
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• v.18 no.6
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• pp.1207-1211
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• 2017

Long-Reach PON (LR-PON) is a broadband access network using passive optical network (PON) technology which the reach is extended to 100 km or higher. A major challenge in LR-PON is that the propagation delay between OLT and ONUs is increased by a very significant amount. To effectively and fairly distribute the upstream bandwidth dynamically in LR-PON, we propose a new periodic and multi-thread polling based dynamic bandwidth allocation (DBA) algorithm. We compare the proposed algorithm with traditional DBAs and show its advantage on average packet delay. Numerical results are analyzed under varying offered loads.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.1
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• pp.32-43
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• 2000

In this paper, we investigate the existing medium access control (MAC) protocols to integrate the voice and data services in packet-based CDMA networks and furthermore, propose a new approach to circumvent the operational limits inherent in them. We propose the $P^2R$-CDMA (Prioritized Packet Reservation Code Division Multiple Access) protocol for the uplink in the synchronous multi-code CDMA system, which employs the centralized frame-based slot reservation along with the dynamic slot assignment in the base station using the QoS-oriented dynamic priority of individual terminal. The simulation results show that, as compared with the existing scheme based on the adaptive permission probability control (APC), the proposed approach can significantly improve the system capacity while guaranteeing the real-time requirement of voice service.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.8B
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• pp.752-759
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• 2002

The capacity of the cell varies with the load of the home and neighboring cells. But most call admission control (CAC) algorithms do not consider the cell loading. In this paper a dynamic call admission control is proposed in a WCDMA system with traffic asymmetry. The proposed algorithm changes the CAC thresholds of new call and handoff call based on channel condition. The blocking and dropping probabilities can be controlled by adjusting these thresholds. The proposed algorithm guarantees the Qos of call class and priority between new call and handoff call. In addition, it can minimize the grade of service (GOS) value with the system throughput maintained.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.2
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• pp.83-88
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• 2001

In this paper, System performance parameters such as throughput, blocking probability and delay have been analyzed and expressed as a function of demanding traffic and service terminating probability, and we centers our discussion at particular downlink port of satellite switch which is capable of switching the individual spot beam and processing the information signals in the packet satellite communications with demand assigned multiple access technique. Delay versa throughput as a function of traffic parameters with several service terminating probability can be derived via mathematical formulation and simulation and the relative change of transmission delay was compared.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.1
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• pp.75-80
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• 2008

Measurement of network traffic have shown that the self-similarity is a ubiquitous phenomenon spanning across diverse network environments. In previous work, we have explored the feasibility of exploiting the long-range correlation structure in a self-similar traffic for the congestion control. We have advanced the framework of the multiple time scale congestion control and showed its effectiveness at enhancing performance for the rate-based feedback control. Our contribution is threefold. First, we define a modular extension of the TCP-a function called with a simple interface-that applies to various flavours of the TCP-e.g., Tahoe, Reno, Vegas and show that it significantly improves performance. Second, we show that a multiple time scale TCP endows the underlying feedback control with proactivity by bridging the uncertainty gap associated with reactive controls which is exacerbated by the high delay-bandwidth product in broadband wide area networks. Third, we investigate the influence of the three traffic control dimensions-tracking ability, connection duration, and fairness-on performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.5
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• pp.1097-1103
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• 2015

In order to build network infrastructure to implement the aforementioned advantages enabling smart device users to work anywhere, professional support and expensive VPN devices are required. This is a barrier to supplying VPN devices to small and medium-sized institutes. To address this issue, this study aims to implement OpenVPN, OpenSSH and iproute based on the OpenWRT platform which is an embedded OS for open networks in affordable open wired/wireless gateway H/W platforms to support the inter-network VPN. In addition, the network environment can be maintained optimal by applying a "multi-queuing real-time traffic shaping technology" to VPN tunnels, although channel quality changes.