• Proceedings of the Korea Society for Simulation Conference
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• 2003.11a
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• pp.139-144
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• 2003

Mobile Node has to maintain communication as they move form place to place, so it doesn't guarantee Quality of Service(QoS). Fast Handoff is important to provide multimedia and real-time applications services in mobile, and it is closely related to handoff delay. Therefore, handoff delay problem is actively studied to quarantee QoS as a main issue in mobile IP research area. Next generation Mobile IPv6 resolve this problem somewhat, triangle problem for first packet and handoff delay still remain. In this paper, we suggest SNMP Information-based routing that adds keyword management method to Information-based routing in active network in order to resolve such a problem, and then suggest QoS controlled handoff based on SNMP Information-Based routing. After modeling of suggested method and existing handoff method, simulations are carried out with NS-2 for performance evaluation. The results of simulations show the some improvement on handoff delay, and therefore on QoS improvement.

• Journal of Communications and Networks
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• v.9 no.4
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• pp.356-367
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• 2007

In large networks, maintaining precise global network state information is impossible. The imprecise network state information has significant impacts on Quality-of-Service(QoS) routing and path establishment. In this paper, we develop analytical models for investigating the QoS routing schemes that are designed to tolerate imprecise network state information, and study the performance of various QoS routing schemes, including randomized routing, multi-path routing, and probability based routing, using both the models and simulations. We further propose a new mechanism, called local rerouting, that improves the effectiveness of QoS path establishment in the presence of imprecise global network state information. Local rerouting is orthogonal to existing schemes for dealing with imprecise state information and can be used in conjunction with them to alleviate the impacts of the imprecise information. The results of our performance study indicate that local rerouting is robust and effective.

• Journal of the Korea Society of Computer and Information
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• v.10 no.3 s.35
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• pp.209-217
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• 2005

In this paper, we propose hierarchical inter-domain load balanced QoS routing in a large scale of network. And a scheme of calculating resources' costs for precomputation schemes in hierarchical routing is proposed. and a scheme for selecting a path among multiple precomputed paths is proposed. We also propose a QoS routing scheme for transit and intra traffic in a large scale of domain-based network. For a domain in the network, the routing scheme first precomputes K multiple paths between all pairs of ingress and egress border routers while considering balancing of the expected load then selects paths with the probability of path selection. The routing scheme combines inter and intra domain routings seamlessly and uses the same cost calculation scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10B
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• pp.947-956
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• 2003

The current IP Routing Protocolspacket networks also need to provide the network QoS based of DiffServ, RSVP, MPLStraffic model which is standardized as IETF reference model for NGN. The first topic of this paper is to propose Traffic-Balanced Routing Protocol(TBRP) to process existing best effort traffic. TBRP will process low priority interactive data and background data which is not sensitive to dealy. Secondly Hierarchical Traffic-Traffic-Scheduling Routing Protocol(HTSRP) is also proposed. HTSRP is the hierarchical routing algorithm for backbone and access networkin case of fixed-wireless convergence network. Finally, HTSRP_Q is proposed to meet the QoS requirement when user want interactive or streaming packet service. This protocol will maximize the usage of resources of access layer based on the QoS parameters and process delay-sensitive traffic. Service classes are categorized into 5 types by the user request, such as conversational, streaming, high priority interactive, low priority interactive, and background class. It could be processed efficiently by the routing protocolstraffic model proposed in this paper. The proposed routing protocolstraffic model provides the increase of efficiency and stability of the next generation network thanks to the routing according to the characteristic of the specialized service categories.

• Journal of KIISE:Information Networking
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• v.29 no.5
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• pp.573-582
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• 2002

We propose centralized server based QoS routing schemes, where a route server is responsible for determining QoS paths on behalf of all the routers in a routing domain. In the proposed server based schemes, the dynamic link QoS state information, which is required for a QoS path computation, is implicitly maintained at route server as it assigns or gets back QoS paths. By maintaining the network state information this way, we may not only eliminate the overhead to exchange network state update message but also achieve higher routing performance by utilizing accurate network state information in path computation. We discuss path caching techniques for reducing the amount of path computation overhead at the route server, and evaluate the performance of the proposed schemes using simulation. The simulation results show that the path caching schemes may significantly reduce the route server load. The proposed schemes are also compared to the distributed QoS routing schemes proposed in the literature. It has been shown that the proposed server based schemes not only enhance the routing performance, but they are also competitive with respect to routing overheads.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.8 s.350
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• pp.1-14
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• 2006

Multi-constraint QoS routing has been seen as crucial network property in the next generation optical Internet based on DWDM Networks. This paper proposes a new QoS routing algorithm based on flooding method, called bounded flooding routing (BFR) algorithm which can meet multi-constraint QoS requirements. Primarily, the BFR algorithm tries to reduce network overhead by accomplishing bounded-flooding to meet QoS requirements, and improve blocking probability and wavelength utilization. Also, as one effort to improve routing performance, we introduce a new concept, ripple count, which does not need any link-state information and computational process. For extensive analysis and simulation study, as a critical concern, in DWDM-based networks we deploy limited wavelength conversion capability within DWDM nodes. And the simulation results demonstrate that the BFR algorithm is superior to other predominant routing algorithms (both original flooding method and source-directed methods) in terms of blocking probability, wavelength channels required and overhead.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1685-1688
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• 2002

Application Routing Load Balancing (ARLB) is a novel load balancing mode that combines QoS routing and load balancing in per application to support QoS far real-time application based on wired network. Zone Routing Protocol (ZRP) is a recent hybrid proactive/reactive routing approach in an attempt to achieve scalability of ad-hoc network. This routing approach has the potential to be efficient in the generation of control traffic than traditional routing schemes. Up to now, without proper load balancing tools, the ZRP can actually guarantee QoS for delay-sensitive applications when congestion occurred in ad-hoc network. In this paper, we propose the ARLB to improve QoS fur delay-sensitive applications based on ZRP in ad-hoc network when congestion occurred and to be forwarding mechanism fur route coupling to support QoS for real-time applications. The critical point is that the routing metric of ARLB is originally designed for wired network environment. Therefore, we study and present an appropriate metric or cost computation routing of ARLB for recently proposed ZRP over ad-hoc network environment.

• Journal of the Korea Society for Simulation
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• v.12 no.3
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• pp.55-68
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• 2003

As mobile IP has been suggested only to support mobility of mobile station(MS) by which it dose nothing but guarantee MS's new connection to the network, it is for nothing in Quality of Service(QoS) after handoff of MS. QoS is very important factor in mobile IP network to provide multimedia applications and real-time services in mobile environment, and it is closely related to handoff delay Therefore as a main issue in mobile IP research area, handoff delay problem is actively studied to guarantee and promote QoS. In this paper, in order to resolve such a problem, we suggest Simple Network Management Network(SNMP) information-based routing that adds keyword management method to information-based routing in active network, and then propose QoS controlled handoff by SNMP information-based routing. After setting up routing convergence time, modeling of suggested method and existing handoff method is followed in order to evaluate the simulations that are carried out with NS-2. The result of simulation show the improvement of handoff delay, and consequently it turns off the QoS has been improved considerably.

• Journal of Communications and Networks
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• v.15 no.3
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• pp.301-311
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• 2013

This paper proposes a policy-based quality of service (QoS) management framework for adaptive routing decisions. We present an approach considering interior gateway protocol (IGP) for path discovery mechanisms and QoS-aware policies for configuring the network elements. The integration of the aforementioned modules into this policy-based network management (PBNM) system is demonstrated by conducting experiments in a real environment, the hellenic public administration network SYZEFXIS. These experiments combine different traffic conditioning mechanisms through event detectors, consider IP service level agreement mechanisms that interoperate with the PBNM system and analyze the enforcement of IGP and QoS policies. Finally, validation and measurement tools are used to prove the efficiency of this framework. It is shown that this architecture offers significantly increased performance and learning capabilities, while the PBNM system achieves adaptive QoS routing through automated configuration considering the avoidance of suboptimal routing issues or under-performance conditions of the network entities.

• The KIPS Transactions:PartC
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• v.9C no.6
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• pp.883-892
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• 2002

Mobile IP has been designed only to maintain communications as they move from place to place, so it doesn't guarantee Quality of Service (QoS). QoS in mobile IP is important to provide multimedia and real-time applications services in mobile environment, and it is closely related to handoff delay. Therefore, handoff delay problem is actively studied to guarantee QoS as a main issue in mobile IP research area. In this paper, we suggest SNMP Information-based routing that adds keyword management method to Information-based routing in active network in order to resolve such a problem, and then suggest QoS controlled handoff based on SNMP Information-based routing. After modeling of suggested method and existing handoff method, simulations are carried out with NS -2 for performance evaluation. The results of simulations show the some improvement on handoff delay, and therefore on QoS improvement.