• Journal of Communications and Networks
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• v.8 no.1
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• pp.116-122
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• 2006

Most of the multimedia applications require strict quality of service (QoS) guarantee during the communication between a single source and multiple destinations. This gives rise to the need for an efficient QoS multicast routing strategy. Determination of such QoS-based optimal multicast routes basically leads to a multi-objective optimization problem, which is computationally intractable in polynomial time due to the uncertainty of resources in Internet. This paper describes a network model for researching the routing problem and proposes a new multicast tree selection algorithm based on genetic algorithms to simultaneously optimize multiple QoS parameters. The paper mainly presents a QoS multicast routing algorithm based on genetic algorithm (QMRGA). The QMRGA can also optimize the network resources such as bandwidth and delay, and can converge to the optimal or near-optimal solution within few iterations, even for the networks environment with uncertain parameters. The incremental rate of computational cost can close to polynomial and is less than exponential rate. The performance measures of the QMRGA are evaluated using simulations. The simulation results show that this approach has fast convergence speed and high reliability. It can meet the real-time requirement in multimedia communication networks.

• The KIPS Transactions:PartC
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• v.9C no.1
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• pp.135-140
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• 2002

An efficient QoS routing scheme needs to find a path that satisfies a given QoS requirements while consuming as few resources as Possible. In this paper, we propose two schemes of calculating resources'costs one for on-demand and one for precomputation QoS routing schemes. These schemes are effective in respect to the global network utilization and the balanced use of network resources. 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 multip1e paths between all pairs of ingress and ogress border routers while considering balancing of the expected load. We, therefore, expect that the paths are bettor than any other paths in respect to reserving the network resources on Paths. The routine: scheme combines inter and intra domain routings seamlessly and uses the same cost calculation scheme. cote that our cost calculation schemes for both kinds of traffic could be used in existing QoS routing protocols without and modification in small and large scale of networks.

• The Transactions of the Korea Information Processing Society
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• v.6 no.11S
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• pp.3229-3242
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• 1999

At recent, the Internet is evolving into the directions which is capable of incorporating stream-type services such as voice and video services due to the remarkable growth of WWW service and the development of new multimedia application services. However, the existing Internet can only support a best-effort delivery model and thus it is difficult to satisfy these requirements as well as to provide the QoS beyond a certain degree. Accordingly, it is imperative to develop QoS-based routing algorithm in order to allow flexible routing by the Internet user's QoS demand and to be applied into wide area networks. In this paper, we presented new routing algorithms for next generation Internet services and made performance evaluations. The proposed algorithms allow the routing by the user's QoS demand level in order to provide the diverse Internet application services based on ATM network environment that is expected to play a role as an infrastructure of next Generation Internet Services.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.7B
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• pp.1239-1251
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• 1999

In this paper a scalable QoS-based hierarchical inter-domain routing scheme for distributed multimedia applications in a high speed wide area network. The problem of QoS-based routing is formulated as a multicriteria shortest path problem, known as NP-complete[21,30]. Our routing scheme consists of two phases. In Phase 1, two graph construction algorithms are performed to model the network under consideration as a graph. The graph contains a part of the network topology which is completely neglected or partially considered by existing routing schemes, thus maintaining more accurate topology information. In Phase 2, a heuristic call-by-call algorithm is performed for selecting a feasible path efficiently in depth first search-like manner on the graph and tailoring to each application's QoS requirements, beginning at a vertex that represents the source node. In this paper, a simple rule is also produced, by which the visiting order of outgoing edges at each vertex on the graph is determined. The rule is based on each edge's the minimum normalized slackness to the QoS requested. The proposed routing scheme extends the PNNI-type hierarchical routing framework. Note that our routing scheme is one of a few QoS-based hierarchical routing schemes that address explicitly the issue of selecting a path with multiple metrics.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.381-385
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• 2004

In this paper, We consider various service models and mechanisms as a part of study for offering QoS with the requirement of user and discuss genetic algorithm and hybrid genetic algorithm for routing optimization in broa㏈and convergence network. If routing optimization based on OSPF is not sufficient, a number of MPLS paths can be set up to further improve QoS. We propose two mixed-integer programming models for the complementary MPLS problem, and consider the maximum link utilization within the network as the relevant network QoS measure

• ETRI Journal
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• v.28 no.6
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• pp.815-818
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• 2006

In the global Internet, a constraint-based routing algorithm performs the function of selecting a routing path while satisfying some given constraints rather than selecting the shortest path based on physical topology. It is necessary for constraint-based routing to disseminate and update link state information. The triggering policy of link state updates significantly affects the volume of update traffic and the quality of services (QoS). In this letter, we propose an adaptive triggering policy based on link-usage statistics in order to reduce the volume of link state update traffic without deterioration of QoS. Also, we evaluate the performance of the proposed policy via simulations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11B
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• pp.744-749
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• 2005

This paper proposes the prediction based QoS routing algorithm, PSS(Prediction Safety-Shortest) algorithm that minimizes network state information overhead and presumes more accurate knowledge of the present state of all the links within the network. We apply time series model to the available bandwidth prediction to overcome inaccurate information of the existing QoS routing algorithms. We have evaluated the performance of the proposed model and the existing algorithms on MCI networks, it thus appears that we have verified the performance of this algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.12B
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• pp.805-810
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• 2005

According to the user requirements for continuous and real-time multimedia information, the concept of Quality of Service (QoS) has emerged as a main issue in mobile ad-hoc networks. QoS routing is to find the route that meets the QoS requirements of the users. In this paper, we propose a routing protocol that is based on AODV over TDMA, one of the typical routing protocols for mobile ad-hoc networks, by making a bandwidth reservation for QoS guarantee. While the existing schemes calculate the maximum available bandwidth for each candidate path, our scheme is to check only if the bandwidth of a given path satisfies the end-to-end QoS requirement and then to make a reservation by allocating time slots efficiently in the wireless environment. In order to evaluate the performance of the proposed QoS routing protocol, some simulations are carried out in the ad-hoc environment.

• Journal of Information Processing Systems
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• v.5 no.2
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• pp.97-104
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• 2009

In this paper we propose a Differentiated Services Based Admission Control and Routing Algorithm for IPv6 (ACMRA). The basic DiffServ architecture lacks an admission control mechanism, the injection of more QoS sensitive traffic into the network can cause congestion at the core of the network. Our Differentiated Services Based Admission Control and Routing Algorithm for IPv6 combines the admission control phase with the route finding phase, and our routing protocol has been designed in a way to work alongside DiffServ based networks. The Differentiated Services Based Admission Control and Routing Algorithm for IPv6 constructs label switched paths in order to provide rigorous QoS provisioning. We have conducted extensive simulations to validate the effectiveness and efficiency of our proposed admission control and routing algorithm. Simulation Results show that the Differentiated Services Based Admission Control and Routing Algorithm for IPv6 provides an excellent packet delivery ratio, reduces the control packets' overhead, and makes use of the resources present on multiple paths to the destination network, while almost each admitted flow shows compliance with its Service Level Agreement.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2413-2417
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• 2003

This paper proposes an improvement of a QoS based routing protocol. The hierarchical source routing algorithm[4] was improved by including of the Crank-Back algorithm[2]. The Crank-Back capability is the ability to solve the problem of selecting the wrong route because of using unsynchronized routing information in the ingress router. In order to reduce time of reversing the call-setup process back to the ingress router, spare-route information is included with a call-setup packet. Spare-route information could be used by every router to find the next appropriated link itself when insufficient resource of the selected link was found. The proposed algorithm improves the performance of the source routing call-setup process significantly.