• Title/Summary/Keyword: 트래픽 부하

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Design Methodology of System-Level Simulators for Wideband CDMA Cellular Standards (광대역 CDMA 셀룰러 표준을 위한 시스템 수준 시뮬레이터의 설계 방법론)

  • Park, Sungkyung
    • Journal of the Korea Society for Simulation
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    • v.22 no.1
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    • pp.41-51
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    • 2013
  • This tutorial paper presents the design methodology of system-level simulators targeted for code division multiple access (CDMA) cellular standards such as EV-DO (Evolution-Data Only) and broadcast multicast service (BCMCS). The basic structure and simulation flow of system-level simulators are delineated, following the procedure of cell layout, mobile drops, channel modeling, received power calculation, scheduling, packet error prediction, and traffic generation. Packet data transmissions on the forward link of CDMA systems and EV-DO BCMCS systems are considered for modeling simulators. System-level simulators for cellular standards are modeled and developed with high-level languages and utilized to evaluate and predict air interface performance metrics including capacity and coverage.

A Multiple Access Scheme Using Split and Merge Algorithm for Centralized Wireless MAC Protocols (중앙 집중형 무선 매체 접근 제어 프로토콜을 위한 분할 및 합병 알고리즘을 이용한 다중 접근 방안)

  • Kim Min-Su;Byun Tae-Young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.8B
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    • pp.757-763
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    • 2006
  • In this paper, a novel multiple access scheme using SMA(Split and Merge Algorithm) is proposed to reduce the accessdelay of wireless MAC protocols. The key idea of the SMA is to dynamically split and merge the contending terminals depending on their traffic loads for effective control of access to the channels. The SMA divides the collided terminals into several sub-groups if a collision occurs and merges the idle terminals of the split sub-groups into their original group. The merge algorithm can be used to resolve collision and split operation can be used to dynamic group management. The simulation results indicate that our algorithm may provide a higher throughput and a lower collision rate than the existing algorithms, especially under heavy traffic loads.

XMPP/SIP Presence Service System using Efficient Message Control Method (효율적 메시지 제어방식을 사용한 XMPP/SIP 프레즌스 서비스 시스템)

  • Jang, Choonseo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.11
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    • pp.2678-2684
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    • 2014
  • In this paper a new message control method that can reduce server load and network traffic in XMPP/SIP presence service system has been proposed. This presence service system can process both XMPP(Extensible Massaging and Presence Protocol) based presence information and SIP(Session Initiation Protocol) based presence information. A new XMPP stanza architecture with added elements for presence stanza and IQ stanza has been designed, and a new presence information data processing method which can reduce size of SIP notification message and SIP PUBLISH message has been suggested. Furthermore a messages exchanging procedure that can transfer presence information between XMPP domain and SIP domain has been also suggested. The performance of the proposed system has been analysed by simulation.

Multimedia Synchronization Method Using Buffer Level (버퍼레벨을 이용한 멀티미디어 동기화 기법)

  • Sung, Kyung-Sang;Lee, Jong-Chan;Lee, Kuen-Wang;Lee, Gi-Sung
    • Annual Conference of KIPS
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    • 2001.10a
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    • pp.155-158
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    • 2001
  • QoS(Quality of Service)측면에서 멀티미디어 응용 서비스를 제공하기 위해서 멀티미디어 통신은 여러 가지 요구사항을 지원하여야 한다. 연속적으로 생성된 미디어의 시간적인 관계를 유지하면서 재생시킬 수 있는 동기화 메커니즘은 무엇보다도 중요한 문제이다. 전달되는 매체를 공동으로 사용하기 때문에 트래픽의 폭주시, 지역적으로 멀리 떨어져 있는 경우에는 지연의 현상이 발생하게된다. 본 논문에서는 지연에 의해 발생되는 지연지터에 대하여 완충역할을 할 수 있는 최소 버퍼크기를 제시하였다. 주문형멀티미디어서버(MOS)의 경우 각 미디어 별로 서버에 저장하여 서비스하는 연구가 현재 활발히 진행되고 있으며 이것은 네트워크의 부하를 줄일 수 있다는 장점을 가지고 있다. 또한 이러한 데이터의 경우 클라이언트에서 어느 정도의 지터를 예상하여 버퍼의 크기를 갖고 있어야 하는 문제는 아직도 큰 문제점으로 나타나고 있다. 본 논문은 버퍼의 크기 및 재생에 관한 동기화 시점을 조정함으로서 버퍼의 오버플로우나 언더플로우의 현상을 방지하고자 한다. 제안한 기법은 기존의 기법보다 향상된 동기화 기법임을 시뮬레이션을 통해 검증하였다.

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Performance Analysis of Soft Handoff Region Ratio in CDMA System Considering System Capacity and Traffic Load (CDMA망에서 시스템 용량과 트래픽 부하의 변화를 반영한 핸드오프 영역 비율에 대한 성능분석)

  • Jung, Sung-Hwan;Hong, Jung-Wan;Lee, Sang-Cheon;Lie, Chang-Hoon
    • IE interfaces
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    • v.20 no.2
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    • pp.216-226
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    • 2007
  • In code-division multiple-access (CDMA) systems with soft handoff, mobile station (MS) within soft handoff region can use multiple radio channels and receive their signals from multiple base stations (BSs) simultaneously. In this paper, the effects of soft handoff region ratio (SHRR) on reverse link of a CDMA cellular system are analytically investigated. In order to analyze the network performance and quality of service (QoS) perceived by users more realistically, both the soft capacity increasing factor and the traffic load variation affected by SHRR are jointly considered and a two-dimensional continuous time Markov chain (CTMC) model is built. In the numerical example, it is observed that the optimal guard channel exists according the variations of the traffic load and propagation conditions when the proper value of SHRR is determined.

The Study on Next Generation Network Security Architecture in the BcN Environment (BcN 환경을 고려한 차세대 네트워크 보안 구조에 관한 연구)

  • 오승희;서동일
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2004.05b
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    • pp.709-712
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    • 2004
  • The BcN is applying from public networks to local networks and each terminal step by step under supporting MIC(Ministry of Information and Communication Repoblic of Korea) until 2007. The architecture of network sorority should considers BcN environment and evolves to manage Ipv6 traffics. The next generation network security architecture can manage not only Ipv6 environment but also wire and wireless integrated network. We suggest the next generation network security architecture for Ipv6 environment and wire-wireless integrated network environment and verify the performance of the suggested architecture using network security scenario.

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Efficient platoon merger control scheme in automated connected vehicle systems (효율적인 자율주행 군집주행집단 관리를 위한 병합 제어 방안)

  • Chung, Young-uk
    • Journal of IKEEE
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    • v.25 no.3
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    • pp.425-429
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    • 2021
  • Vehicle platooning in automated connected vehicle systems is an efficient transportation operation model that not only significantly reduces computational load and networking overhead of the central system but also improves traffic flow. For efficient platoon group management, it is important to maintain the platoon group size appropriately and to control the merge request of a new vehicle and other group member vehicle. In this paper, we present a merger control scheme that accepts or rejects merge requests based on the current group size and the priority of vehicles. The proposed method was analyzed and validated through mathematical models based on Markov chains. Performance evaluation shows that the proposed scheme properly manages the load of the central system.

Implementation and Fault-tolerance Tests of High Availability System in Cloud Environment (클라우드 환경에서의 고가용성 시스템 구현 및 결함 내성 시험)

  • Koh, Seok-ju;Son, Jong-young;Kim, Sun-hee;Cho, Hyun-kyung;Bae, Keun-ryeong;Ji, Ho-jun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2019.05a
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    • pp.74-77
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    • 2019
  • Many enterprises and public institutions are building their own server stabilization system. Nevertheless, many web servers including some public institutions have frequent obstacles due to the unexpected causes such as traffic concentration. Data loss during each of these situations and business interruption can cause a huge loss. In this study, we propose high-availability Web system that uses load balancing and session clustering. Each deals with the failure due to the over traffic by distributing incoming requests in the multiplexed web server and provides the continuous services by maintaining session information of the users in case of the failure of some servers.

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Adaptive Resource Allocation Techniques for Efficient Data Transfer in WAVE Communication Systems (WAVE 통신 시스템에서 효율적인 데이터 전송을 위한 적응적 자원 할당 기법)

  • Han-Sol Song;Si-Hyun Kim;Gi-Cheol Sung;Yeung-Cheol Lee;Jae-Wan Kim
    • Annual Conference of KIPS
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    • 2024.05a
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    • pp.147-148
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    • 2024
  • WAVE 표준의 채널 구조는 하나의 제어 채널(CCH)과 여러 개의 서비스 채널(SCH)로 나뉜다. SCH 는 비안전 데이터 전송을 위해 사용되며 CCH 는 비콘 및 제어 메시지(즉, 서비스 광고 메시지)의 브로드캐스팅을 위해 사용된다. 두 간격 모두 표준에서 고정된 값(50ms)으로 설정되어 있다. 그러나 고정 길이 간격은 동적으로 변화하는 트래픽 부하에 대해 효과적으로 대응할 수 없다. 또한, 많은 차량이 동시에 제한된 채널 자원을 사용하여 데이터를 전송할 때 수많은 패킷 충돌로 인해 통신 성능이 크게 저하된다. 본 논문에서는 네트워크 성능을 향상하기 위한 적응적 자원 할당 기법을 제안한다.

Effective Parent-Child Key Establishment Algorithm used ZigBee Sensor Network (ZigBee 센서네트워크에서 효율적인 Parent - Child 키 연결 알고리즘)

  • Seo, Dae-Youl;Kim, Jin-Chul;Kim, Kyoung-Mok;Oh, Young-Hwan
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.10 s.352
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    • pp.35-45
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    • 2006
  • Coordinator is defining so that function as most trust center that is point in security in ZigBee Alliance. Because must do height connection with coordinator in device signing to PAN newly, coordinator has shortcoming that subordinate is revealed to danger directly to Centered and cattish device. When do height connection some device, do not become problem, but if network is huge, coordinator's subordinate shall increase as traffic quantity which happen in coordinator increases. Also, in ZigBee security to link network kina of transmission and mutually certification in ZigBee Alliance standard include, but I do not provide method to deliver master key in each node safely. Because process that transmit master key passes through channel that do not secure, master key has shortcoming that is revealed directly. In this paper, I suggested Parent-Child key establishment algorithm to solve these problem. Proposed algorithm consists of two structures. Master key establishment algorithm and device that sign to PAN newly that can use one-way Hash chain and transmit master key safety are consisted of Parent-Child network key establishment algorithm that do child node and parent node key establishment as can do key establishment efficiently. Method that device proposes in case method that propose in case have master key establishment time was shown better performance $200{\sim}1300ms$ than existing method, and device does not have master key than existing method height connect time about $400{\sim}500ms$ better performance see.