• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.196-198
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• 2014

최근 차세대 네트워크 패러다임으로 주목받는 소프트웨어 정의 네트워킹 (SDN)에서는 네트워크를 컨트롤 플레인과 데이터 플레인으로 나누고 중앙집중형 제어를 통해 효과적이고 유연한 네트워크 관리를 가능하게 한다. 하지만 잦은 컨트롤 이벤트 발생으로 인한 컨트롤러 및 컨트롤 채널의 부하와 거대한 플로우 엔트리 크기로 인한 스위치 내 TCAM(Temary Content Addressable Memory) 메모리 부족문제 등의 본질적인 문제로 실제 네트워크 적용 시 확장성 문제가 야기된다. 이러한 문제를 해결하기 위해 기존의 연구들은 컨트롤러의 연산능력을 향상시키거나, 컨트롤 이벤트의 발생을 줄이는데 초점이 맞춰져 왔으며, 한정적인 TCAM 공간의 효율적인 사용에 대한 연구는 부족한 상황이다. 따라서 본 논문에서는 효율적인 TCAM 자원 활용을 위한 플로우테이블 관리 기법을 제안한다. 제안 기법은 플로우 엔트리의 클러스터링을 통해 플로우 엔트리를 특성에 따라 그룹화하고 사용빈도를 기준으로 분할 및 병합을 수행함으로써 스위치 내의 가용한 플로우 수를 최대화한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.969-972
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• 2009

With the advent of the era of ubiquitous computing, the number of wireless communication devices has been exponentially increasing, which phenomenon requires for the preparation for the upcoming shortage of frequency resource. Recently, in consequence, the concept of Cognitive Radio (CR) was introduced in which the wireless nodes periodically recognize and learn the external conditions of communication including the usage of the frequency spectrum. It is essential to assure sufficient range of frequency to satisfy the users of the increasing wireless network devices. However, since not only the frequency band for wireless communication is finite, but most part of them had already been assigned for the primary users of the wireless network service, it is very difficult to ensure the band of frequency for additional communication service. In this contribution, we analyze and describe the issues of designing and implementation of CR networks.

• Convergence Security Journal
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• v.16 no.2
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• pp.19-23
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• 2016

The design, management, and operation of network infrastructure have evolved during the last few years, leveraging on innovative technologies and architectures. With such a huge trend, due to the flexibility and significant economic potential of these technologies, software defined networking (SDN) and network functions virtualization (NFV) are emerging as the most critical key enablers. SDN/NFV enhancing the infrastructure agility, thus network operators and service providers are able to program their own network functions (e.g., gateways, routers, load balancers) on vendor independent hardware substrate. They facilitating the design, delivery and operation of network services in a dynamic and scalable manner. In NFV, the management and orchestration (MANO) orchestrates other specific managers such as the virtual infrastructure manager (VIM) and the VNF Manager (VNFM). In this paper, we examine the contents of these NFV MANO systematically and proposes a security system in a virtualized environment.

• The Journal of Bigdata
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• v.8 no.2
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• pp.141-148
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• 2023

Recent advancements in the integration of satellite technology and the Internet of Things (IoT) have led to the development of a sophisticated network ecosystem, capable of generating and utilizing vast amounts of big data across various sectors. However, this integrated network faces significant security challenges, primarily due to constraints like limited latency, low power requirements, and the incorporation of diverse heterogeneous devices. Addressing these security concerns, this paper explores the construction of a satellite-IoT network through the application of Software Defined Networking (SDN). While SDN offers numerous benefits, it also inherits certain inherent security vulnerabilities. To mitigate these issues, we propose a novel approach that incorporates blockchain technology within the SDN framework. This blockchain-based SDN environment enhances security through a distributed controller system, which also facilitates the authentication of IoT terminals and nodes. Our paper details the implementation plan for this system and discusses its validation through a series of tests. Looking forward, we aim to expand our research to include the convergence of artificial intelligence with satellite-IoT devices, exploring new avenues for leveraging the potential of big data in this context.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.94-96
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• 2021

Software-Defined Networking (SDN), which has emerged to overcome the limitations of existing network architectures, makes routing management simpler and more efficient through a central controller. SR (Segment Routing) is a flexible and scalable way of doing source routing, and defines the information path of the network through a list of segments arranged in the packet header. In an SDN environment, the performance of each router is almost the same, but packets tend to be concentrated on routes that are frequently used depending on routing algorithms. Routers in that path have a relatively high frequency of failure and are more likely to become bottlenecks. In this paper, we propose a routing algorithm that allows the router, which is a resource in the network, to evenly process packets in the SDN with SR, so that the administrator can utilize the resources in the network without idle routers, and at the same time facilitate the management of the router.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.6
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• pp.406-413
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• 2014

In recent years, various contents traffics are increasing according to the various internet connectable devices which have become contents provider. Because these contents traffics show different pattern from previous one, many researches for efficient contents delivery system are in progress. CCN(Contents Centric Network), one of the representative research subject, has inter operation problem with a current network because it has clean-state architecture. In this point of view, this paper suggests the SaNA(Service adaptive Network Architecture) for efficient contents delivery when it inter operates with current network architecture. SaNA is a convergence system which can be gradually applied to current network using CCN and SDN(Software Defined Network) which are core future internet technologies. Appling this system on the contents delivery service, it can increase the network bandwidth utilization by two times and decrease the contents delivery time by 1.7 times.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.9
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• pp.35-46
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• 2011

Future Internet should support more efficient mobility management, flexible traffic engineering and various emerging new services. So, lots of traffic engineering techniques have been suggested and developed, but it's impossible to apply them on the current running commercial Internet. To overcome this problem, OpenFlow protocol was proposed as a technique to control network equipments using network controller with various networking applications. It is a software defined network, so researchers can verify their own traffic engineering techniques by applying them on the controller. In addition, for high-speed packet processing in the OpenFlow network, programmable NetFPGA card with four 1G-interfaces and commercial Procurve OpenFlow switches can be used. In this paper, we implement an OpenFlow test-bed using hardware-accelerated NetFPGA cards and Procurve switches on the KREONET, and implement CSPF (Constraint-based Shortest Path First) algorithm, which is one of popular QoS routing algorithms, and apply it on the large-scale testbed to verify performance and efficiency of multimedia traffic engineering scheme in Future Internet.