• Title/Summary/Keyword: 지연 한계 보장

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A Preventive Intra-Path Load Balancing Based on the Probabilistic Characteristics of the Quality-of-service (서비스 품질의 확률적 특성에 기초한 예방적 경로 부하 밸런싱)

  • Kim, Tae-Joon;Suh, Bong-Sue
    • Journal of Korea Multimedia Society
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    • v.13 no.2
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    • pp.279-286
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    • 2010
  • Unbalanced traffic load offered to the nodes making up a path in the network guaranteeing quality-of-service has been known as a main cause deteriorating the capability of the path in admitting traffic flows. Several path load balancing methods have been developed to resolve this problem which used a feedback control scheme that adjusts the delay budget of a flow allocated to each node according to the conditions of available resource in the path. Because of no consideration about the probabilistic characteristics of the service quality, it is impossible for them to prevent in advance a bottleneck on the path which leads to a native restriction in the improvement of the capability being deteriorated. This paper proposes a preventive intra-path load balancing method applicable to the RSVP system which is based on the probabilistic characteristics of the quality-of-service of the offered load. The results of the simulation of the proposed method on a simple evaluation network showed that it provides the gain of 4~22% compared to the legacy one in terms of the number of admitted flows.

Streaming Service Scheduling Scheme in Mobile Networks (모바일환경에서 실시간 데이타서비스를 위한 스케줄링 정책)

  • Min Seung-Hyun;Kim Myung-Jun;Bang Kee-Chun
    • Journal of Digital Contents Society
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    • v.3 no.1
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    • pp.47-57
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    • 2002
  • Recently, wireless networks have been pursuing multimedia data service as voice, data, image, video and various form of data according to development of information communication technology. It guarantees cell delivery delay of real time data in efficient real time multimedia data transfer. Also, it minimizes cell loss rate of non-real time multimedia data. In the wireless ATM, there are based on Asynchronous Transfer Mode(ATM). It implies that there are various service with difficult transmission rates and qualities in the wireless communication network. As a result, it is important to find out the ways to guarantee the Quality of Service(QoS) for each kind of traffic in wireless network. In this thesis, we propose an improved TCRM scheduling algorithms for transmission real-time multimedia data service in wireless ATM Networks. We appear real time multimedia scheduling policy that apply each different method to uplink and downlik to wireless ATM network. It can guarantee QoS requirements for each real time data and non-real time data. It also deals the fairness problem for sharing the scarce wireless resources. We solve fault of TCRM as inefficient problem of non-real data by using arbitrary transmission speed and RB(Reservation Buffer) through VC(Virtual Control) and BS(Base Station).

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Some evidence on time- and priority-dependent pricing in differentiated Internet Services (우선순위를 가진 인터넷 서비스 종량제와 종가제 사용에 대한 증거들)

  • Kim, Yong-Jae
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2008.10b
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    • pp.547-550
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    • 2008
  • 인터넷 서비스가 차별화 되어야 한다는 논의는 인터넷이 본격적으로 상용화된 1990넌대 중반부터 꾸준하게 제기되어 왔다. Tragedy of commons 라고 불리는 인터넷 혼잡현상은 지속적인 기술발전으로 인해서 상당부분 해결되었으나, 최근 들어서는, Web 2.0의 등장을 통해 동영상 파일이 차지하는 비중이 늘어나면서 P2P를 통한 파일교환이 전체 인터넷 트래픽의 상당 부분을 차지하면서, 또한 실시간 미디어, VoIP 등의 인터넷 응용 프로그램 등에서 전송상의 지연을 포함한 QoS 보장을 요구하게 되면서, 또한 통신사업자의 망중립성에 관한 논의가 진행되면서, 인터넷 서비스를 차별화하고, 통제하려는 연구의 중요성이 증대되고 있다. 본 연구는 인터넷 서비스를 차별화하기 위한 수단으로 기존에 제시되어온 자격과 우선순위라는 2개의 차원에서 그리고 가격제도로서 종가제와 종량제의 차원에서 배경을 검토해본 다음, 우선 대기열 이론과 혼잡성 제어 이론을 통해서 차별화된 서비스가 전체 시스템에어떤 구체적으로 효익을 가져오는 지를 검토하며, 우선순위와 사용시간에 따라 차별화되는 종량제가 현실에서 발견되지 않는 이유에 대한 이론적인 근거를 제시하고, 종량제를 채택했을 경우에 발생하는 문제점과 종량제 사용에서 발생하는 한계들을 논의하면서, 현실적으로 종량제와 차별가격을 도입할 때 발생할 수 있는 문제점들을 밝혀본다.

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Study on Agent based Internetworking Platform (에이전트 기반 인터네트워킹 플랫폼 연구)

  • 전준현
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.3B
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    • pp.314-324
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    • 2004
  • Recently, high-speed internet subscribers have grown continuously, and reached up to 10 millions. But existing network management that is responsible only for user access is confronted with many difficulties, since user access network(xDSL, Cable, B-WILL, and so on) has diversified and value added wired/wireless contents service has developed. In this paper propose the Agent based Inter Networking platform as object-oriented hierarchical system that can provide various service such as access QoS(Quality of Service), customized application service and security service according to user on demand. This system has divided into two parts(user agent and agent management system & local and central management systems). Management system periodically receive status information such as bandwidth, download speed, delay, current service, and so on, and process them, then build a policy based on processed information. According to personal user profile that is generated by this policy, the customized service can be provided for users. And This system adopt the object-oriented modeling in case that system migration and integration, and implement a system that is robust and stable for security through hierarchical server system.

An Improved Depth-Based TDMA Scheduling Algorithm for Industrial WSNs to Reduce End-to-end Delay (산업 무선 센서 네트워크에서 종단 간 지연시간 감소를 위한 향상된 깊이 기반 TDMA 스케줄링 개선 기법)

  • Lee, Hwakyung;Chung, Sang-Hwa;Jung, Ik-Joo
    • Journal of KIISE
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    • v.42 no.4
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    • pp.530-540
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    • 2015
  • Industrial WSNs need great performance and reliable communication. In industrial WSNs, cluster structure reduces the cost to form a network, and the reservation-based MAC is a more powerful and reliable protocol than the contention-based MAC. Depth-based TDMA assigns time slots to each sensor node in a cluster-based network and it works in a distributed manner. DB-TDMA is a type of depth-based TDMA and guarantees scalability and energy efficiency. However, it cannot allocate time slots in parallel and cannot perfectly avoid a collision because each node does not know the total network information. In this paper, we suggest an improved distributed algorithm to reduce the end-to-end delay of DB-TDMA, and the proposed algorithm is compared with DRAND and DB-TDMA.

P2Prefix : Efficient Broadcasting Streaming Scheme Based on P2P Caching (P2Prefix : P2P 캐싱 기반의 효율적인 브로드캐스트 스트리밍 기법)

  • Lee, Chi-Hun;Choi, Young;Choi, Hwang-Kyu
    • Journal of Internet Computing and Services
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    • v.8 no.2
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    • pp.77-87
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    • 2007
  • A typical VOD service allows that a number of remote clients playback a desired video from a large collection of videos stored in one or more video servers. The main bottleneck for a VOD service is the network bandwidth connecting to the VOD server to the client due to the high bandwidth requirements. Many previous researches have shown that VOD server can be greatly improved through the use of multicast, broadcast, or P2P scheme. Broadcast is one of the most efficient techniques because it can transmit a stream to many users without additional network bandwidth. But the broadcast has long latency time. In order to overcome the drawback, in this paper, we propose P2Prefix broadcast scheme that can solve the service latency time, which is the problem of broadcast scheme, by using P2P caching as well as minimizing the client buffer requirement.

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Analysis of Performance and IKEv2 Authentication Exchange model in Mobile IPv6 Network (MIPv6망에서 IKEv2 인증 교환 모텔 및 성능 분석)

  • Ryu, Dong-Ju;Kim, Gwang-Hyun;Kim, Dong-Kook
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.11A
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    • pp.1085-1091
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    • 2006
  • For an experiment in this paper, designed test bed to secure confidentiality of data and safe transmission that Mobile node exchanges in Mobile network. And, For IPsec use that support basically in MIPv6, modeling and experimented IKEv2 protocol that is used for reliable authentication key management and distribution between End Point. When Mobile node handoff in Mobile network, analyzed effect that authentication key re-exchange and limited bandwidth that happen often get in key exchange. And studied about Performance and latency about authentication setting and exchange process that use multi interface. To conclusion, when Mobile node transmits using IPSec, re-authentication of key confirmed that re-setting by limit of bandwidth that existent Mobile network has can be impossible. According to other result, proposed MN's multi interface is expected to minimise key exchange latency by hand-off when transmit IPSec.

Improving the Implementation Complexity of the Latency-Optimized Fair Queuing Algorithm (최적 레이턴시 기반 공정 큐잉 알고리즘의 구현 복잡도 개선)

  • Kim, Tae-Joon;Suh, Bong-Sue
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.6B
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    • pp.405-413
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    • 2012
  • WFQ(Weighted Fair Queuing) is the most popular fair queuing algorithm to guarantee the Quality-of-Service(QoS), but it has the inherent drawback of a poor resource utilization, particularly under the low rate traffic requiring a tight delay bound. It was recently identified that the poor utilization is mainly due to non-optimized latency of a traffic flow and then LOFQ(Latency-Optimized Fair Queuing) to overcome the drawback was introduced. The LOFQ algorithm, however, renews their optimal latencies for all flows whenever a new flow arrives, which results in the high implementation complexity of O($N^2$).This paper is to reduce thecomplexity to O(1). The proposed method is first to derive the optimal latency index function from the statistical QoS characteristics of the offered load, and then to simply calculate the optimal latency index of the arriving flow using the function.

Robust and Non-fragile H Controller Design Algorithm for Time-delayed System with Randomly Occurring Uncertainties and Disturbances ) (임의발생 불확실성 및 외란을 고려한 시간지연시스템의 강인비약성 H 제어기 설계 알고리듬)

  • Yang, Seung Hyeop;Paik, Seung Hyun;Lee, Jun Yeong;Park, Hong Bae
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.12
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    • pp.89-98
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    • 2015
  • This paper provides a robust and non-fragile $H_{\infty}$ controller design algorithm for time-delayed systems with randomly occurring polytopic uncertainties and disturbances. First, we design time-delayed system considering randomly occurring uncertainties and disturbances. Next, The sufficient condition for the existence of robust and non-fragile $H_{\infty}$ controller is presented by LMI(linear matrix inequality) using Lyapunov stability analysis and $H_{\infty}$ performance measure. Since the obtained condition can be expressed as a PLMI(parameterized linear matrix inequality) by changes of variables and Schur complement, all solutions including controller gain, degrees of controller satisfying non-fragility, $H_{\infty}$ norm bound ${\gamma}$ can be calculated simultaneously. Finally, numerical examples are given to illustrate the performance and the effectiveness of the proposed robust and non-fragile $H_{\infty}$ controller compared with the deterministic uncertainty model even though there exists randomly occurring uncertainties, disturbances and time delays.

Service Curve Allocation Schemes for High Network Utilization with a Constant Deadline Computation Cost (상수의 데드라인 계산 비용으로 높은 네트웍 유용도를 얻는 서비스 곡선 할당 방식)

  • 편기현;송준화;이흥규
    • Journal of KIISE:Information Networking
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    • v.30 no.4
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    • pp.535-544
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    • 2003
  • Integrated services networks should guarantee end-to-end delay bounds for real-time applications to provide high quality services. A real-time scheduler is installed on all the output ports to provide such guaranteed service. However, scheduling algorithms studied so far have problems with either network utilization or scalability. Here, network utilization indicates how many real-time sessions can be admitted. In this paper, we propose service curve allocation schemes that result in both high network utilization and scalability in a service curve algorithm. In service curve algorithm, an adopted service curve allocation scheme determines both network utilization and scalability. Contrary to the common belief, we have proved that only a part of a service curve is used to compute deadlines, not the entire curve. From this fact, we propose service curve allocation schemes that result in a constant time for computing deadlines. We through a simulation study that our proposed schemes can achieve better network utilizations than Generalized processor Sharing (GPS) algorithms including the multirate algorithm. To our knowledge, the service curve algorithm adopting our schemes can achieve the widest network utilization among existing scheduling algorithms that have the same scalability.