• Journal of Internet Computing and Services
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• v.6 no.3
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• pp.121-128
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• 2005

Recently, as the research of effective resource management for supporting of various next generation internet service, the admission control mechanisms using the dynamic provisioning methods in differentiated service networks are studied. However, even though admission control mechanism is applied to the network, there exits the unfairness of call blocking probability among the different bandwidth requested services. In this paper, we propose the new admission control policy heuristic algorithm that provides fairness of call blocking probability between the large bandwidth requested service and the small bandwidth requested service. The simulation results show that the proposed algorithm provides not only blocking probability fairness but also high bandwidth utilization.

• Journal of the Korea Computer Industry Society
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• v.6 no.3
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• pp.391-400
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• 2005

최근 몇 년 사이 컴퓨터와 초고속 통신망의 대중적인 보급으로 인하여 인터넷 사용 인구가 급격하게 증가하였고 인터넷 사용량 또한 폭발적으로 증가하였다. 이와 같이 막대한 양으로 늘어난 트래픽은 서버에 과도한 양의 부하를 발생시켜 서비스 전반에 걸친 성능 저하를 가져왔다. 따라서 서버에 많은 양의 트래픽이 발생하더라도 정상적인 서비스를 제공할 수 있도록 하는 것이 필요하다. 본 논문에서는 이러한 서버의 트래픽 폭주로 인한 서버 과부하 문제를 해결하기 위해 수락 제어 알고리즘을 이용한다. 수락 제어 기법은 컨텐츠 변환이나 로드 밸런싱과 같이 수동적으로 부하를 덜어주거나 분산시키는 방식이 아닌 트래픽에 제한을 가하여 능동적으로 서버의 부하를 조절하는 방식이다. 클라이언트에 의한 연결 요청이 이루어질 때 서버의 부하 상태를 평가한 후 서버가 수용 가능한 수준이면 클라이언트 새로운 연결 요청을 수락하여 이를 서비스할 수 있도록 한다. <중략> 또한 서비스 요청에 제한적인 정책을 따를 경우 서버의 부하 변화에 빠르게 반응하지만 QoS(Quality of Service)의 향상을 얻을 수 있는 반면 더 많은 서비스 요청을 수용하는 정책을 취할 경우 서버의 부하 변화에 대한 반응이 느리지만 throughput이 증가하는 이득을 얻을 수 있게 된다. QoS와 throughput가 서로 tradeoff 관계에 있다는 것을 알 수 있다. 또한 요구되는 서비스의 성격에 따라 즉 더 높은 수준의 QoS 보장이 중요한 서비스인가 아니면 더 높은 수준의 throughput 보장이 요구되는 서비스인가에 따라 다른 수락 제어 정책을 적용하는 것이 가능하게 된다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.2
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• pp.45-53
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• 2000

In wireless environment, due to the limited capacity of radio channels it is not easy to guarantee QoS provisioning to mobile users. Therefore, one of the key problems to support broadband multimedia multi-services in wireless ATM networks is to study an effective call admission control(CAC). The purpose of this paper is to propose a distributed CAC scheme that guarantees multi QoS and multi-class service. Control parameters of the proposed scheme are QoS threshold and channel overload probability. With these parameter control, we show that the scheme can guarantee the requested QoS to both new and handover calls. In the scheme, channels are allocated dynamically, and QoS measurements are made in a distributed manner. We show that by providing variable data rate to calls it can effectively prohibit the QoS degradation even if there are severe fluctuations of network traffic. We compare the proposed CAC scheme to the well-known schemes such as guard band call admission control scheme. Through numerical examples and simulations, the proposed scheme is shown to improve the performance by lowering the probability of handover call dropping

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.4
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• pp.293-298
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• 2004

To satisfy the requirements for QoS and acceptance ratio of the users using multimedia content service, it is required to control mechanism for QoS assurance and allocation of the stream server' resources based on CoS(Class of Service). To compare performance of the algorithm, we have classified the user by two classes (super class, base class) and control the acceptance ratio of user's requests by user's class information. We have experimented the test of network resources and test of processing time under server/client environment and agent environment. MA-URFA based on agent increases the acceptance ratio of super class and utilization ratio of network resources.

• Convergence Security Journal
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• v.4 no.3
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• pp.57-82
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• 2004

The confluence of computers, communications, and databases is quickly creating a distributed database where many applications require real-time access to temporally consistent sensor data. We have developed an object-oriented real-time database system called BeeHive to provide a significant improvement in performance and functionality over conventional non-real-time database and object management systems. In this paper, the performance of two data-deadline cognizant scheduling policies EDDF and EDF-DC and the baseline EDF policy with/without admission control are evaluated through extensive experiments on BeeHive. The ranges where data-deadline cognizant scheduling policies are effective and where admission control plays a role are identified.

• The Journal of the Korea Contents Association
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• v.12 no.4
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• pp.69-75
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• 2012

In this paper, to provide various services of QoS, and moreover applying traffic ratio to CAC(Call Admission Control) algorithm tested how long average data rate and the average packet delay time. When CAC algorithm is not applied, traffic mixture ratio is 1:1:4:4, the FTP Service 0.4, web services 0.6, streaming service 0.7, the packet delay requirements are not satisfied. On the other hand CAC Algorithm is applied, all the service of packet delay are satisfied with arrival rate. Therefore, we can make sure that applying of CAC of traffic control WWW, FTP, Video, VoIP can guarantee the various services of QoS.

• Journal of Korean Institute of Industrial Engineers
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• v.35 no.2
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• pp.171-177
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• 2009

This study presents the switching strategy between admission control and pricing control policies and clarifies the properties of the switching strategy in an M/M/1/K queueing system. In addition, this study demonstrates that employing the switching strategy can significantly improve the maximum total expected profit.

• The Journal of the Acoustical Society of Korea
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• v.22 no.3
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• pp.242-249
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• 2003

When special voice control application services (VCS) such as voice-controlled web browsing or voice-controlled stock transactions are introduced in cellular systems, a channel quality better than that for ordinary voice communications service (OVS) is necessary in order to keep a suitable grade of VCS. To avoid ai. congestion, calls are normally admitted if there exists a channel-processing resource not occupied by other calls in the base as well as the interference level at the receiver is not higher than a predefined threshold. The threshold is usually 10㏈ noise-rise over the background noise level for voice communications service. When the base admits VCS attempts in exactly the same manner as it handles OVS calls. the same fraction of those will be not successful in taking the channel and then blocked. If the same noise-rise threshold is used as 10 ㏈, however, the admitted VCS calls might suffer from bad channel qualify and finally be dropped. From the user's point of view, the forced termination of ongoing calls is significantly undesirable than blocking new call attempts. When using a lower noise-rise threshold for VCS. on the other hand, the blocking probability of VCS gets higher than that of OVS. In this paper, a call admission policy that gives a priority to VCS is considered in order to reduce the blocking probability and keep an adequate channel quality.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.7-7
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• 2004

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.2
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• pp.91-100
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• 2015

In this study, we propose an efficient two-phase heuristic policy, called an acceptance tolerance control policy, for Infrastructure as a Service (IaaS) cloud services that considers both the service provider and customer in terms of profit and satisfaction, respectively. Each time an IaaS cloud service is requested, this policy determines whether the service is accepted or rejected by calculating the potential for realizing the two performance objectives. Moreover, it uses acceptance tolerance to identify the possibility for error with the chosen decision while compensating for both future fluctuations in customer demand and error possibilities based on past decisions. We conducted a numerical experiment to verify the performance of the proposed policy using several actual IaaS cloud service specifications and comparing it with other heuristics.