• Korean Management Science Review
• /
• v.11 no.2
• /
• pp.147-159
• /
• 1994

The problems of determining appropriate QOS(Quality of service) requirements of B-ISDN services and finding the corresponding NP(Network Performance) values satisfying the given QOS requirements are very important problems which are directly related to the successful operation of the ATM network, but have not been studied with enough attention yet. The QOS(NP) parameter definition, QOS measurements, and QOS managements are three major problems that should be solved. In this paper, we first introduce the basic concepts of QOS and NP and their relationships. Then we discuss more comprehensive concepts of QOS based on the layered structure of ATM services and the reference time, which can provide a systematic approach for QOS and NP mapping problems. We also provide examples of determining basic QOS(NP) parameters in the ATM layer and a specific example of QOS mapping based on the file transfer in ATM. The results of this paper can be used to establish the comprehensive QOS management model.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.22 no.6
• /
• pp.1148-1159
• /
• 1997

In the broadband integrated service digital networks (B-ISDN), ATM switches hould be abld to accommodate diverse types of applications ith different traffic characteristics and quality ddo services (QOS). Thus, in order to increase the utilization of switches and satisfy the QOS's of each traffic type, some types of priority control schemes are needed in ATM switches. In this paper, a nonblocking input and output queueing ATm switch with capacity C is considered in which two classes of traffics with different loss probability constraints are admitted. 'Partial push-out' algorithm is suggested as a loss priority control schemes, and the performance of this algorithm is analyzed when this is adopted in input buffers of the switch. The quque length distribution of input buffers and loss probabilities of each traffic are obtained using a matrix-geometric solution method. Numerical analysis and simulation indicate that the utilization of the switch with partial push-out algorithm satisfying the QOS's of each traffic is much higher than that of the switch without control. Also, the required buffer size is reduced while satisfying the same QOS's.

• Proceedings of the IEEK Conference
• /
• 1998.10a
• /
• pp.3-6
• /
• 1998

This paper considers the analysis of QoS(Quality of Service) routing mechanisms to support the NGIs(Next Generation Internets). NGIs are constructing high-speed IP layer networks to support all data services. To support real time multimedia services on NGIs, it is important to satisfy the required QoS parameters on networks. To support QoS requirements for NGI networks, new QoS routing methods are essential. In this paper, serveral new QoS routing algorithms are explained. Some problems for the high speed QoS routing will be explained and possible solutions are suggested.

• Journal of the Korea Society of Computer and Information
• /
• v.14 no.3
• /
• pp.121-131
• /
• 2009

BcN provides a wide variety of high-quality multimedia services such as broadcasting and communication convergence services. But the quality degeneration is observed in BcN when we use broadcasting and communication convergence service via more than one network of different internet service providers. In this paper, a QoS management system which is able to measure and maintain objectively the quality-related information in overall networks is proposed. The proposed QoS management system is tested on the pilot networks of BcN consortiums by measuring the quality of voice and video experienced by the actual users of the commercial video phone services. The result of the experiment shows that it is possible to figure out service qualify between a user and a service provider by analyzing the information from agents. The per-service traffic information collected by probes is proved to be useful to pinpoint the party responsible for the loss of the service qualify in case of the services including different service providers. As the result of the experiment, it is shown that the proposed QoS management system would play a key role of resolving the quality dispute, which is one of the important issues of QoS-guaranteed BcN.

• Journal of Internet Computing and Services
• /
• v.19 no.2
• /
• pp.33-41
• /
• 2018

In recent years, technology is rapidly changing to support new service consumption and distribution models in multimedia service systems and hybrid delivery of media services is a key factor for enabling next generation multimedia services. This phenomenon can lead to rapidly increasing network traffic and ultimately has a direct and aggravating effect on the user's quality of service (QOS). To address the issue, we propose a novel system architecture to provide smart hybrid media services efficiently. The architecture is designed to apply the software-defined networking (SDN) method, detect changes in traffic, and combine the data, including user data, service features, and computation node status, to provide a service schedule that is suitable for the current state. To this end, the proposed architecture is based on 2-level scheduling, where Level-1 scheduling is responsible for the best network path and a computation node for processing the user request, whereas Level-2 scheduling deals with individual service requests that arrived at the computation node. This paper describes the overall concept of the architecture, as well as the functions of each component. In addition, this paper describes potential scenarios that demonstrate how this architecture could provide services more efficiently than current media-service architectures.

• International Journal of Contents
• /
• v.5 no.3
• /
• pp.8-13
• /
• 2009

The recent Web service field emerges as the fastest growing IT paradigm as a result of the increasing interest in SOA (Services-Oriented Architecture) and the expansion of B2B market. With an increasing number of Web service that provide similar features, it becomes more important to provide the most appropriate service for the user's request. A service user in general requires the quality information of Web service when selecting a service among a number of similar Web services. Yet, finding a service through UDDI (Universal Description, Discovery and Integration) does not consider the non-functional aspects of users because it is only based on the functional aspects. That is, the quality, non-functional aspect will be an important factor for the mutual success of the user and provider. Using 3 factors in the Qos factors of the existing studies: the execution cost, reliability, and the quality level, the QoS of Web service is saved and the factors for the QoS are recorded in order to consider non-functional factors when selecting a Web service in this study. The Quality Broker determines the rank and shows the desired result of the service for users. The Quality Broker suggested in this thesis can be used to select a Web Service that considers the user-oriented and non-functional factors.

• Journal of the Korea Society of Computer and Information
• /
• v.10 no.6 s.38
• /
• pp.227-232
• /
• 2005

A network of Packet based switch Mode will be required to carry the traffics(CVR,VBR, UBR, ABR) generated by a wide range of services. Packet based Network services the quality-of-Service (QoS) management of traffic sources and bandwidth. Besides efficiency and throughput services are achieved in the multimedia traffic sent in the network. In this paper. the scheduler transmits the safe packet, drop the unsafe packet and evaluate unsafe packet as the requirement of the delay avoiding the network congestion for improving the QoS of the multimedia network In this paper. we Propose the scheduling algorithm which evaluates and drops the packet . The suggested model performance of the switch is estimated and simulated in terms of the delay by computer.

• Proceedings of the Korean Information Science Society Conference
• /
• 2002.10e
• /
• pp.598-600
• /
• 2002

SIP(Session Initiation Protocol) 프로토콜은 인터넷에서 다양한 세션을 위한 시그널링 프로토콜로서 오디오, 비디오 등의 멀티미디어 세션에 주로 사용되고 있다. 또한 망 유지보수 및 관리가 편리하고 다른 시스템과의 확장성 및 유연성이 뛰어나다는 장점을 갖고 있는 반면 기본적으로 Best Effort 서비스만을 지원하는 IP 네트워크에서 QoS(Quality of Service)를 제공하기 때문에 서비스의 품질에 대한 고려가 미약하다. 따라서 본 연구에서는IP 네트워크를 기반으로 하는 SIP에서 QoS를 제공하기 위해 IntServ(Integrated Services)와 DiffServ(Differentiated Services)를 연동한 QoS 메카니즘을 제시한다.

• The Journal of the Korea Contents Association
• /
• v.10 no.3
• /
• pp.80-91
• /
• 2010

Due to the convergence of broadcasting and communications, IPTV services are spotlighted as the that next-generation multimedia services. IPTV services should have functionality such as unlimited channel capacity, extension of media, QoS awareness and are required increasing traffic and quality control technology to adapt the attributes of IPTV service. Consequently, flow based quality control techniques are needed. Therefore, many studies for providing Internet QoS are performed at IETF (Internet Engineering Task Force). As the buffer management mechanism among IP QoS methods, active queue management method such as RED(Random Early Detection) and modified RED algorithms have proposed. However, these algorithms have difficulties to satisfy the requirements of various Internet user QoS. Therefore, in this paper we propose the Flow based AQM(Active Queue Management) algorithm for the multimedia services that request various QoS requirements. The proposed algorithm can converge the packet loss ratio to the target packet loss ratio of required QoS requirements. And we present a performance evaluation by the simulations using the ns-2.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.33B no.5
• /
• pp.52-59
• /
• 1996

The boroadband ISDN will transprot the traffics for a wide range of applications with different quality-of-service (QOS) requirements and the priorit control mechanism is an effective method to support multiple classes of services. This paper proposes a new mechanism to satisfy simultaneously the different levels of cell loss performance for the two classes of heterogeneous nonreal-time ATM traffics as well as the delay and loss requirements of real-time traffics. Its performance is analyzed using the stochastic integral approach with the cell arrivals of input streams modeled as markov modulated poisson processes.