• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.22 no.5
• /
• pp.1007-1017
• /
• 1997

The existing survivability measure is defined as the only ratio of survival traffic volume on the given traffic demand. In this paper we suggest a new network survivability evaluation model. Sinceit depends on the importance of traffic, we can evaluatethe affect of telecommunication disaster. With the suggested evaluation model we formulate optimization models for restoration paths and traffic assinment on them. The optimization models are represented as mixed integer programming problems, which are difficult to find exact solutions. We develop heuristic algorithms according to the optimization models and apply them to an example network with 10 nodes and 17 links.

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 1994.06a
• /
• pp.183-186
• /
• 1994

• ETRI Journal
• /
• v.14 no.4
• /
• pp.236-248
• /
• 1992

본 고에서는 국내 신호망에 사용될 NO.7 신호방식을 채택한 신호중계교환기 SMX-1 시스팀의 메시지전달부(MTP)중 레벨2 신호링크 기능에 대한 소프트웨어의 설계 및 구현에 대하여 기술하였다. SMX-1 시스팀내에서 요구하는 레벨2 신호링크의 기능은 NO.7 신호방식-메시지전달부 국내기준안에서 제시한 신호링크 고유기능, 고신뢰도가 만족되도록 설계된 SMX-1 시스팀의 유지보수기능, SMX-1 시스팀 운용시 망상태 파악 및 가용도 등을 파악하기 위해 필요한 측정 및 감시 기능들이 구현되었다. 또한 신호링크 고유기능중에서도 설계자 구현 의존 사항들인 신호 전송로 차단때의 감지 기능, 신호링크 폭주 기능, 옥텟계수 모드 처리기능, 긴 메시지 수신처리 기능 등이 구현되었다. 구현 완료된 신호링크기능이 NO.7 신호방식-메시지전달부 국내기준안에서 요구하는 메시지전달부 신호전송성능의 신호트래픽 처리용량을 만족하는지를 확인하기 위하여 NO.7 프로토콜 분석기를 통하여 시험하였으며 그 결과를 분석 및 기술하였다.

• The Journal of the Korea Contents Association
• /
• v.11 no.12
• /
• pp.578-585
• /
• 2011

Nowadays, wireless local area networks are widely deployed so that stations can potentially associate with an access point. The AP selection strategy is one of the significant research areas for wireless local area networks. The selection strategy solves the relevant problem is which AP can be selected and associated with a station so that the efficient resource utilization can be obtained. Rather than merely choosing the AP with the strongest received signal strength, however, we calculate effective throughput for each neighboring AP and use it as a basis for AP selection. Referencing the throughput is better than referencing the signal strength only because the network may contain a severe load imbalance. We have performed computer simulations using OPNET modeler in order to verify the performance of the proposed scheme. The results show us that the proposed selection method outperforms that of the conventional one in terms of throughput and delay.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.1
• /
• pp.1-10
• /
• 2014

The characteristics of internet traffic was dramatically changed recently. Especially, the ratio of video traffic in internet network is highly increased. Because the video traffic changes the traditional interactive traffic transport into one way contents delivery, internet network pricing structure is not efficient to reflect this changes. The fundamental reason for these is the discontinuity between the cost and revenue of the internet traffic. Although the internet traffic is forecasted to grow highly, the revenue of network provider is not expected to increase as such. The present paper investigates various alternatives to improve the present business model and to accommodate traffic growth. Then, the desirable options is proposed to invoke the innovation and to reflect the price signal according to some criteria.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.45 no.3
• /
• pp.103-112
• /
• 2008

In this paper we present two databases for two different systems each having novel implementation ideas: a u-Healthcare system with a mobile gateway and MAGI network monitoring system. u-Healthcare system is capturing and monitoring vital sign data without restrictions of location and time using body sensor network and a mobile gateway. MAGI is a system which has a dynamic firewall function and solves problems of existing traffic monitoring tools. In addition to presenting the design principles behind these two systems, we describe the respective database schemas together with detailed information of the data stored within the databases. We will also show and discuss performance measurements and calculations for both systems. Based on the performance data we will discuss the systems' suitability for their intended uses.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.12B
• /
• pp.1083-1096
• /
• 2008

This paper proposes an energy-aware path management scheme, so-called the TBP(Threshold based Back-Pressure) algorithm, which is designed for lifetime extension of the energy-constrained wireless sensor networks. With the goal of fair energy consumptions, we extensively utilize the available paths between the source and the sink nodes. The traffic distribution feature of the TBP algorithm operates in two scales; the local and the whole routing area. The threshold and the back-pressure signal are introduced for implementing those operations. It is noticeable that the TBP algorithm maintains the scalability by defining both the threshold and the back-pressure signal to have their meanings locally confined to one hop only. Throughout several experiments, we observe that the TBP algorithm enhances the network-wide energy distribution. which implies the extension of the network lifetime. Additionally, both the delay and the throughput outcomes show remarkable improvements. This shows that the energy-aware path control scheme holds the effects of the congestion control.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.5B
• /
• pp.820-829
• /
• 2000

In this paper, DSPA(Dynamic Signalling Period Allocation) algorithm that has been proposed by the authors for MAC(Medium Access Control) protocols in W-ATM(Wireless Asynchronous Transfer Mode) is applied to mixed traffic conditions composed of various service classes. We investigate the bandwidth utilization efficiency and quality of service(QoS) fulfillment by the DSPA algorithm used in W-ATM MAC protocols. Simulation results indicate that the DSPA algorithm significantly increases the throughput of the system with the minimum control overhead. Moreover, QoS of each service class is well satisfied by proper and fair channel allocation to different service classes according to their requirements.

• Journal of the Institute of Convergence Signal Processing
• /
• v.5 no.1
• /
• pp.79-83
• /
• 2004

The purpose of ATM traffic management is to protect the network using minimum resources and guarantee the requred QoS and also it is desirable to provide fairness between input channels. In this paper, we propose the TBBM(threshold based buffer management) algorithm to improve fairness between input channels and utilization of ATM networks. TBBM algorithm controls output cell rate dynamically based on threshold. The result shows that the required bandwidth of the TBBM algorithm is 14.3% lower in audio traffic and 41.8% lower in video traffic than that of theoretically calculated equivalent capacity method. and also reveals that the TBBM algorithm provide improved CLR fairness between input channels

• Proceedings of the Korea Institute of Convergence Signal Processing
• /
• 2000.12a
• /
• pp.5-8
• /
• 2000

In this paper, The new scheme for Demand Assigned Multiple Access(DAMA) system is proposed. To focus on the onboard processor's specific monitoring of output port of the downlink, we found the Throughput and Blocking probability by the request traffic(λ) and channel's departure probability(Ρ).