• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.22-26
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• 2007

In the fibre to the home (FTTH) era, it is expected that broadband network provisioning will require thousands of optical fibres to be accommodated in a central office for optical access networks. An optical fibre line testing system could be used to reduce maintenance costs and improve service availability depending on the PON's element manager capabilities and the maintenance procedures adopted by the network supplier. When monitoring optical fibres transmitting communication lights, a wavelength of 1625 nm is used for maintenance testing. The splitter installed optical filters allow the communication light to pass but that cut off the test light in the front of optical line terminals (OLTs) and optical network terminals (ONTs). In the economic point of view, We design new planer lightwave circuit splitter embedded filtter and study it optical property.

• Proceedings of the IEEK Conference
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• summer
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• pp.57-60
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• 2004

Next generation wireless network is evolving toward IP-based network that can various provide multimedia services. A challenge in wireless mobile Internet is support of quality of service over wireless access networks. DiffServ architecture is proposed for evolving wireless mobile Internet. In this paper we propose an algorithm for optimal buffer partitioning which requires the minimal channel capacity to satisfy the QoS requirements of input traffic. We used a partitioned buffer with size B to serve a layered traffic at each DiffServ router. We consider a traffic model with a single source generates traffic having J $(J\geq2)$ quality of service (QoS) classes. QoS in this case is described by loss probability $\varepsilon_j$. for QoS class j. Traffic is admitted or rejected based on the buffer occupancy and its service class. Traffic is generated by heterogeneous Markov-modulated fluid source (MMFS).

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.2 no.3
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• pp.9-16
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• 2003

In this paper, we propose the burst error reduction (BER) algorithm for VoIP service in the wireless LAN network. In end point device, this BER algorithm can be achieved packet loss bounded QoS provisioning using interleaving in buffering and FEC (Forward Error Correction) through transmitting voice packet. BER algorithm can reduced the voice packet loss rate 5.5%-60% in VoIP network using wireless LAN.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.4A
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• pp.241-249
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• 2005

ATM based MPLS(Multiprotocol Label Switching) is discussed for its provisioning QOS commitment capabilities, Traffic engineering and smooth migration for BcN in Korea. At this time, due to the comprehensive nature of ATM protocol, ATM has been adapted as the backbone system for carrying Internet traffic[1,2,3,4]. This paper presents preventive congestion control mechanisms for detecting HTR(Hard-To-Reach) LSP(Label Switched Path) in ATM based MPLS systems. In particular, we have introduced a HTR LSP detection method using network signaling information in an ATM layer. MPLS related studies can cover LSP failures in a physical layer fault, it can not impact network congestion status. Here we will present the research results for introducing HTR LSP detection methods and control mechanisms and this mechanism can be implementing as SOC for high speed processing a packet header. We concluded that it showed faster congestion avoidance abilities with a more reduced system load and maximized the efficiency of network resources by restricting ineffective machine attempts.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.381-385
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• 2004

In this paper, We consider various service models and mechanisms as a part of study for offering QoS with the requirement of user and discuss genetic algorithm and hybrid genetic algorithm for routing optimization in broa㏈and convergence network. If routing optimization based on OSPF is not sufficient, a number of MPLS paths can be set up to further improve QoS. We propose two mixed-integer programming models for the complementary MPLS problem, and consider the maximum link utilization within the network as the relevant network QoS measure

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.202-204
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• 2003

변화하는 인터넷 환경에서의 005 보장은 빼놓을 수 없는 중요한 과제로 각종 제안들이 나오고 있다. 본 논문에서는 IETF(Internet Engineering Task Force)에서 제안한 Diffserv 네트워크에서 Host-to-Host의 QoS 보장에 관하여 다루었으며, DSCP(Differentiated Service Codepoint)값의 설정을 Edge Router가 아닌 Host에서 수행하여 경계라우터의 Traffic 부하를 줄이고, MWRR2(Modified Weighted Round Robin Mode2) 방식의 스케줄링을 통해 더욱더 향상된 Diffserv network에서의 Host-to-Host QoS를 제공하는 것이 목적이다. 본 논문은 IETF에서 제안된 Diffserv 방식과 본 논문에서 제안된 Diffserv 방식의 효율성 입증을 위하여, ns2 시뮬레이션을 사용하여, 비교 분석하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.143-146
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• 2015

Software Defined Network (SDN) separates control plane and data plane to achieve benefits such as centralized management, centralized provisioning, lower device cost and more flexibility. In SDN, scalability is an important issue. Centralized controller can be a bottle neck and many research tried to solve this issue on the control plan. However, scalability issue does not only happen in the control plane, but also happen in the data plane. In the data plane, flow table is an important component and its size is limited. In a large network operated by SDN technology, the performance of the network can be highly degraded because of the size limitation of a flow table. In this paper, we propose a ranking-based flow replacement method, Flow Table Management (FTM), to overcome this problem.

• International Journal of Computer Science & Network Security
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• v.22 no.4
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• pp.89-100
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• 2022

With the advancement in the Internet of things Technology (IoT) cloud computing, billions of physical devices have been interconnected for sharing and collecting data in different applications. Despite many advancements, some latency - specific application in the real world is not feasible due to existing constraints of IoT devices and distance between cloud and IoT devices. In order to address issues of latency sensitive applications, fog computing has been developed that involves the availability of computing and storage resources at the edge of the network near the IoT devices. However, fog computing suffers from many limitations such as heterogeneity, storage capabilities, processing capability, memory limitations etc. Therefore, it requires an adequate task scheduling method for utilizing computing resources optimally at the fog layer. This work presents a comprehensive review of different task scheduling methods in fog computing. It analyses different task scheduling methods developed for a fog computing environment in multiple dimensions and compares them to highlight the advantages and disadvantages of methods. Finally, it presents promising research directions for fellow researchers in the fog computing environment.

• Proceedings of the Korea Information Processing Society Conference
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• 2018.10a
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• pp.362-364
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• 2018

Predicting network traffic volume has become a popular topic recently due to its support in many situations such as detecting abnormal network activities and provisioning network services. Especially, predicting the volume of the next upcoming traffic from the series of observed recent traffic volume is an interesting and challenging problem. In past, various techniques are researched by using time series forecasting methods such as moving averaging and exponential smoothing. In this paper, we propose a long short-term memory neural network (LSTM) based network traffic volume prediction method. The proposed method employs the changing rate of observed traffic volume, the corresponding time window index, and a seasonality factor indicating the changing trend as input features, and predicts the upcoming network traffic. The experiment results with real datasets proves that our proposed method works better than other time series forecasting methods in predicting upcoming network traffic.

• Journal of Communications and Networks
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• v.3 no.4
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• pp.317-323
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• 2001

Traditional configuration management involves complex labor-intensive processes performed by experts. The configuration tasks such as installing or reconfiguring a system, provisioning network services and allocating resources typically involve a large number of activities involving multiple network elements. The network elements may be associated with proprietary configuration management instrumentation and may also be spread across heterogeneous network domains thereby increasing the complexity of configuration management. This paper introduces an architecture for the self-configuration of networks (SELFCON). The proposed architecture involves a directory server, which is uses to maintain configuration information. The configuration information stared in the directory server is modeled using the standard DEN specification thereby allowing effective exchange of network, system and configuration management data among heterogeneous management domains. SELFCON associates configuration intelligence with the components of the network, rather than limit it to a centralized management station. The network elements are notified about related changes in configuration policies, based upon which, they perform self-configuration. SELFCON is able to provide automation of configuration management and also an effective unifying framework for enterprise management.