• Journal of KIISE:Information Networking
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• v.34 no.1
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• pp.73-80
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• 2007

This paper presents an approach to support dynamic QoS(Quality of Service) requirements of largely emerging SIP(Session Initiation Protocol) multimedia applications in broadband access networks. The topology of QoS-enabled broadband access networks and its operational model to support SIP QoS are firstly suggested. And then the procedures to bind QoS-enabled SIP signaling into an IP QoS mechanism are presented. In this paper, DiffServ-based IP QoS architecture is deployed due to the complexity problem of the other IntServ architecture, and COPS(Common Open Policy Service) and COPS-PR protocol based signaling mechanisms are used to support dynamic DiffServ QoS, correspondent with dynamic SIP QoS. The broadband access network is assumed to support rapidly expanding Metro Ethernet 802.1 D/Q QoS, and how to translate SIP QoS parameters into IP DiffServ classes and DiffServ classes into 802.1 D/Q QoS parameters is also presented in this paper.

• Journal of KIISE:Information Networking
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• v.29 no.6
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• pp.722-737
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• 2002

As the number of multimedia applications increases, various protocols and architectures have been proposed to provide QoS(Quality of Service) guarantees in the Internet. Most of these techniques, though, bear inherent contradiction between the scalability and the capability of providing QoS guarantees. In this paper, we propose a protocol, named DQSP(Dynamic QoS Support Protocol), which provides the dynamic resource allocation and admission control for QoS guarantees in a scalable way. In DQSP, the core routers only maintain the per source-edge router resource allocation state information. Each of the source-edge routers maintains the usage information for the resources allocated to itself on each of the network links. Based on this information, the source edge routers perform admission control for the incoming flows. For the resource reservation and admission control, DQSP does not incur per flow signaling at the core network, and the amount of state information at the core routers depends on the scale of the topology instead of the number of user flows. Simulation results show that DQSP achieves efficient resource utilization without incurring the number of user flow related scalability problems as with IntServ, which is one of the representative architectures providing end-to-end QoS guarantees.

• The KIPS Transactions:PartC
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• v.13C no.5 s.108
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• pp.613-620
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• 2006

From both techlical and economic viewpoints, DiffServ IP QoS architecture is accepted as a more practical solution because of the complexity Problem of the other IntServ architecture. In this paper, we propose several models to support DiffServ QoS in DSL broadband access networks and discuss about migration path from current best-effort DSL networks to DiffServ-enabled ones. Since DSL networks are recently and widely deployed in the world amount ot new investment, compatibility with existing QoS-unaware DSL systems, and compatibility with existing charging systems as well as effective support of various QoS services must be carefully considered when we design DiffServ QoS support models in DSL networks. The DiffServ models proposed in this paper are divided into static DiffServ models and dynamic DiffServ models which are near-term solutions and long-term solutions repecitively. The static DiffServ models include Flat DiffServ which suworts per-subscriber DiffServ QoS and Structured DiffServ which supports per-subscriber and per-service DiffServ QoS. And the dynamic DiffServ models include Direct DiffServ for P2P(Peer to Peer) applications and Indirect DiffServ for ASP(Application Service Provider) applications.

• Journal of the Korea Society for Simulation
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• v.12 no.4
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• pp.51-59
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• 2003

Real-Time applications on Grid environment have several problems in terms of resource management addressed as follows; (1) dynamic resource allocation to provide QoS objectives, (2) heterogeneous resources that is different scale, or capacity in same unit, and (3) resource availability, and resource needs. This paper describes the techniques of resource manager (RM) handling above problems to support QoS of dynamic real-time applications on Grid. The contributions of this paper to solve problems are as follows: unification of dynamic resource requirements among heterogeneous hosts, control of resources in heterogeneous environments, and dynamic load balancing/sharing. Our heuristic allocation scheme works not only 257% better than random, 142% better than round robin, and 36.4% better than least load in QoS sensitivity, but also 38.6% better than random, 28.5% better than round robin, and 31.6% better than least load in QoS.

• Journal of the Korea Society of Computer and Information
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• v.14 no.4
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• pp.77-86
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• 2009

At present, Web services become main means to construct web applications. As the number of web services grows and various kind of web services have been produced, QoS properties of web services are one of important criteria to select more appropriate web services. However, the selected web services may become inappropriate for the Requester's requirements, because QoS is kind of dynamic properties. this paper proposes a framework that proposed that finds an appropriate web service for Requester's QoS requirements, and dynamically replaces an inappropriate web service with right one. The problems which happen in substitution step are also identified and the solutions are described with an illustrative example.

• Journal of the Korea Society of Computer and Information
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• v.9 no.2
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• pp.139-147
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• 2004

To provide Internet QoS, the IETF Proposed two models of Integrated Services (IntServ) and Differentiated Services (DiffServ) Unlike IntServ where resource reservation and admission control is Per-flow based using RSVP. DiffServ supports aggregated traffic classes to provide various QoS to different classes of traffics. However a dynamic QoS management system is required to dynamically provide differentiated QoS for customers who require dynamic QoS change. This paper designed and implemented therefore a policy-based QoS management system to manage effectively and configure dynamically QoS of DiffServ networks. The validity of the system has been verified by the experimentation on the Linux-based DiffServ network.

• ETRI Journal
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• v.27 no.1
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• pp.13-21
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• 2005

Many multicast applications, such as video-on-demand and video conferencing, desire quality of service (QoS) support from an underlying network. The differentiated services (DiffServ) approach will bring benefits for theses applications. However, difficulties arise while integrating native IP multicasting with DiffServ, such as multicast group states in the core routers and a heterogeneous QoS requirement within the same multicast group. In addition, a missing per-flow reservation in DiffServ and a dynamic join/leave in the group introduce heavier and uncontrollable traffic in a network. In this paper, we propose a distributed and stateless admission control in the edge routers. We also use a mobile agents-based approach for dynamic resource availability checking. In this approach, mobile agents act in a parallel and distributed fashion and cooperate with each other in order to construct the multicast tree satisfying the QoS requirements.

• Journal of IKEEE
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• v.7 no.1 s.12
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• pp.63-71
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• 2003

In this paper, we propose an DSR(Dynamic Source Routing) protocol to support QoS for reliable data transmission in the mobile ad-hoc network. The proposed algorithm uses DSR protocol to support QoS as its basic routing protocol, and uses the nodes which are between source and destination nodes as key QoS support. Because of moving nodes there is some problem that is restricted reliable data transmission. For solve this problem, source node set up the QoS link with destination node. The nodes that are located at QoS link and find out loss of transmission path save the transmitting data packets. Those search a new transmission path to destination node and transmit the saved data packet to destination node. As the result of evaluation, we found the proposed QoS network guaranteed reliable data transmission with almost 100% data reception rate for slowly moving mobile ad-hoc network and with more 96% data reception rate, which is improvement of 3.7737% reception rate compared with none QoS network, for continuously fast moving mobile ad-hoc network.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.505-508
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• 2003

• Journal of Communications and Networks
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• v.15 no.1
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• pp.61-70
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• 2013

The increasing number of mobile users and the popularity of real-time applications make wired-wireless integrated network extremely attractive. In this case, quality of service (QoS) adaptability is particularly important since some important features of the integrated network call for QoS adaptability, such as mobility, bursty applications and so on. Traditional QoS schemes include integrated service (IntServ) and differentiated service (DiffSev) as well as their variants. However, they are not able to balance well between scalability and QoS granularity. For example, IntServ faces the scalability problem, while DiffServ can only provide coarse granular QoS. In addition, they are also unable to efficiently support QoS adaptability. Therefore, a per-packet differentiated queueing service (DQS) was proposed. DQS was originally proposed to balance between scalability and QoS granularity in wired networks and then extended to wireless networks. This paper mainly discusses how to use DQS to support QoS adaptability in wired-wireless integrated networks. To this end, we propose a scheme to determine dynamic delay bounds, which is the key step to implement DQS to support QoS adaptability. Simulation studies along with some discussions are further conducted to investigate the QoS adaptability of the proposed scheme, especially in terms of its support of QoS adaptability to mobility and to bursty real-time applications.