• 한국경영과학회지
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• 제26권3호
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• pp.65-77
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• 2001

Survivability of a network is one of the most important issues in designing present-day communication networks. the k-edge survivability of a given network is defined as the percentage of total traffic surviving the worst case failure of k edges. Although several researches calculated k-edge survivability on small networks by enumeration, prior research has considered how to calculate k-edge survivability on large networks. In this paper, we develop an efficient procedure to obtain lower and upper bounds on the k-edge survivability of a network.

• 대한산업공학회지
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• 제34권2호
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• pp.181-189
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• 2008

Survivability of a network is one of the most important issues in designing present-day communication networks. For the past few decades, a lot of researches have proposed the mathematical models to evaluate the survivability of networks. In this paper, we attempt to survey such researches and classify them based on how these researches measure the survivability of a network.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권2호
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• pp.620-636
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• 2015

Survivability is a necessary property of network system in disturbed environment. Recovery ability is a key actor of survivability. This paper concludes network survivability into a novel composite metric, i.e. Network Recovery Degree (NRD). In order to measure this metric in quantity, a concept of Source-Destination Pair (SD Pair), is created to abstract end-to-end activity based on end nodes in network, and the quality of SD Pair is also used to describe network performance, such as connectivity, quality of service, link degree, and so on. After that, a Survivability Test method in large scale Network based on SD pairs, called STNSD, is provided. How to select SD Pairs effectively in large scale network is also provided. We set up simulation environment to validate the test method in a severe destroy scenario and evaluate the method scalability in different large scale network scenarios. Experiment and analysis shows that the metric NRD correctly reflects the effort of different survivability strategy, and the proposed test method STNSD has good scalability and can be used to test and evaluate quantitative survivability in large scale network.

• 한국시뮬레이션학회논문지
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• 제13권2호
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• pp.65-73
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• 2004

The capability to provide the network service must survive even if a significant network system element is disrupted. To sustain the network service under the system failure, network survivability mechanisms minimizing the impact of failures are needed. Also, since the mobile network has its unique characteristic, the survivability scheme for the vulnerability of the mobile network is required. This paper proposes a survivability scheme to support the reliable service of the wireless access point level (BS-base station system). By the survivability scheme, the mobile network can use an overlap BS of the cellular network architecture after a BS system failure. We analyze the performance of the proposed scheme using Markov model. Also, a computer simulation is used for the scheme analysis. The proposed scheme shows that the service of the mobile network can be provided under the BS system failure.

• 한국산학기술학회논문지
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• 제7권6호
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• pp.1185-1193
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• 2006

차세대 인터넷과 같은 무한 네트워크에서 정보시스템은 다양한 공격과 사고의 발생으로 손상을 입고 그 사용자들은 막대한 비용의 손실을 입는다. 본 논문에서는 보안 시스템의 비용효과 측면에서 적정수준의 투자를 할 수 있는 효과적인 의사결정을 지원할 수 있도록 하는 정보시스템의 생존성 관리 모델을 제안하였다. 시뮬레이션을 통하여 서비스 가중치를 고려한 비용에 따라 생존성이 어떻게 변화하는지를 검사하였다. 방어 비용이 방어 수준에 따라 변화하기 때문에 비용/생존성과 서비스 가중치/생존성 그래프를 도출하여 관리자가 적정 수준의 보안을 유지하는 방어 비용을 결정할 있도록 하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권9호
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• pp.4023-4043
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• 2016

Network virtualization has been regarded as a core attribute of the Future Internet. In a network virtualization environment (NVE), multiple heterogeneous virtual networks can coexist on a shared substrate network. Thus, a substrate network failure may affect multiple virtual networks. In this case, it is increasingly critical to provide survivability for the virtual networks against the substrate network failures. Previous research focused on mechanisms that ensure the resilience of the virtual network. However, the resource efficiency is still important to make the mapping scheme practical. In this paper, we study the survivable virtual network embedding mechanisms against substrate link and node failure from the perspective of improving the resource efficiency. For substrate link survivability, we propose a load-balancing and re-configuration strategy to improve the acceptance ratio and bandwidth utilization ratio. For substrate node survivability, we develop a minimum cost heuristic based on a divided network model and a backup resource cost model, which can both satisfy the location constraints of virtual node and increase the sharing degree of the backup resources. Simulations are conducted to evaluate the performance of the solutions. The proposed load balancing and re-configuration strategy for substrate link survivability outperforms other approaches in terms of acceptance ratio and bandwidth utilization ratio. And the proposed minimum cost heuristic for substrate node survivability gets a good performance in term of acceptance ratio.

• 디지털융복합연구
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• 제14권8호
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• pp.269-276
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• 2016

재난망용 LTE(Long Term Evolution)는 자가망을 기본으로 구축하고 일부 상용망 시설을 활용함으로써 비용을 절감하는 방향으로 구축되고 있다. 하지만, LTE 망은 기지국, 교환기 등 정보통신 기반시설 붕괴 시 망 생존성과, 폐쇄된 건물 내부 또는 지하구간 등 음영지역에서의 통신 커버리지가 취약하다는 한계가 있다. 본 연구에서는 기존에 활용하고 있는 검증된 기술들의 융합을 통해 망 생존성 기술을 제공하는 방안을 도출하였다. IoT시대의 도래에 따라, 사물과 환경 속에 내재된 스마트 센서는 컴퓨팅 파워와 네트워킹 모듈을 포함하여 망 생존성 구현을 위해 매우 유용한 기반을 제공한다. 본 연구에서는, 이러한 스마트센서의 특성을 기반으로 스몰셀 기술과 무선 네트워크 커버리지 확장기술을 융합함으로써 망 생존성을 효과적으로 구현하기 위한 USN(Ubiquitous Sensor Network) 싱크노드 아키텍처를 기획하였다. 사물과 환경 속에 내재된 컴퓨팅 파워는 재난재해 발생 시 유용한 자원으로 활용될 수 있을 것으로 기대된다.

• 한국인터넷방송통신학회논문지
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• 제9권6호
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• pp.117-123
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• 2009

본 논문에서는 일반적인 서바이벌특성을 2가지 형태로 분류하여 그 특정을 살펴보고, 네트워크에 이용 가능한 형태를 찾는다. 그리고 이중홈 방식을 이용하여 네트워크 형태에 따른 비용을 분석한다. 또한 서바이벌특성을 가능하게 해주는 네트워크의 물리구조를 최소비용으로 설계할 수 있는 휴리스틱알고리즘을 제안하고 그 결과를 분석하여 실제 네트워크설계에 쉽게 적용할 수 있음을 보인다.

• Management Science and Financial Engineering
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• 제16권3호
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• pp.85-93
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• 2010

Given an undirected network with a set of source-sink pairs, we are assumed to get a benefit if a pair of source and sink nodes are connected. The k-edge survivability of a network is defined as the total benefit secured after arbitrarily selected k edges are destroyed. The problem of computing k-edge survivability is known to be NP-hard and has applications of evaluating the survivability or vulnerability of a network. In this paper, we consider the k-edge survivability problem restricted to ring networks and develop an algorithm to solve it in O($n^3$|K|) time where n is the number of nodes and K is the set of source-sink pairs.

• 융합보안논문지
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• 제8권1호
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• pp.91-100
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• 2008

The previous works in sensor networks security have focused on the aspect of confidentiality, authentication and integrity based on cryptographic primitives. There has been no prior work to assess the survivability in systematic way. Accordingly, this paper presents a survivability model of wireless sensor networks using software rejuvenation for dual adaptive cluster head. The survivability model has state transition to reflect status of real wireless sensor networks. In this paper, we only focus on a survivability model which is capable of describing cluster head compromise in the networks and able to switch over the redundant cluster head in order to increase the survivability of that cluster. Second, this paper presents how to enhance the survivability of sensor networks using software rejuvenation methodology for dual cluster head in wireless sensor network. We model and analyze each cluster as a stochastic process based on Semi Markov Process (SMP) and Discrete Time Markov Chain (DTMC). The proof of example scenarios and numerical analysis shows the feasibility of our approach.