• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.2B
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• pp.250-262
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• 2004

In IPv6 environment, the Internet Telephony, VoD(Video on Demand) and high capacity file exchange service will be more increased than IPv4. Therefore, the strict guarantee of QoS based on End-to-End and differentiated quality control schemes are simultaneously required. This paper proposes the flow control schemes on IPv6 network that the traffic is identified by flow and the QoS of multi-service is improved by QoS information in IPv6 hop-by-hop option header. The object of flow control includes not only non-default QoS traffic, which uses the flow label, but also best-effort or encrypted traffic. Therefore, the guarantee of real-time service is strengthened and the flow, which abuses unnecessarily the network resources, is effectively controlled. Also, this paper proposes the mapping scheme between the flow and MPLS by reflecting the minimum change of the existed network resource and the status of backbone network of ISP(Internet Service Provider). In the simulation result, It is shown that the proposed scheme is effective in the side of QoS on real-time services and utilization of backbone resources.

• International Journal of Contents
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• v.2 no.2
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• pp.10-16
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• 2006

In this paper, we propose a predictive resource metric region (RMR) based radio resource metric estimation (RRME) mechanism, which utilizes a resource metric mapping function (RMMF), both of which permit efficient inter-working between the physical layer and higher layers for envisaging multimedia service applications over a CDMA communication system platform. The RMR can provide the acceptable resource region where QoS and acceptable link quality can be guaranteed with an achievable resource margin to be utilized in terms of capacity margin, the degree of confidence (DCL) of user, second-order statistics of Eb/Io. With predicted capacity margin and variance, DCL can deliver decision parameters with which an adaptive QoS based admission control can perform well taking capacity and resource availability into account in a dynamic and predictive manner. Combined with advanced techniques such as adaptive modulation or rate control and power control, the proposed mechanism can adjust the conventional stringent link quality information efficiently, and deliver accurate information of the resource availability. Thus, these can guarantee the maximization of resource utilization of multimedia service applications.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05b
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• pp.1341-1344
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• 2003

최근 다양한 정보통신 서비스 창출과 향상된 성능을 가진 장치 개발 등으로 인해 정보통신서비스 시장이 확대되고 있다. 본 논문은 통신망에 대한 종단간 사용자의 서비스 질을 향상시키기 위하여, 인터넷의 대표적인 전달망인 IP 망에서의 QoS(Quality of Service)와 하부 전달망(ATM 망 프레임 릴레이망)에서의 QoS 간의 상관 관계를 손실 지표를 이용하여 분석함으로써 품질 지표간 맵핑 방안을 제안한다. 본 연구를 통해 종단간 서비스 품질 수준을 제공하기 위한 하부망에서의 손실의 수준 값을 알 수 있게된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.2
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• pp.473-494
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• 2020

To provide a guaranteed Quality of Service (QoS) to real-time traffic in High-Speed Downlink Packet Access (HSDPA) core network, we proposed an enhanced mechanism. For an enhanced QoS, a Class-Based Low Latency Fair Queueing (CBLLFQ) packet scheduling algorithm is introduced in this work. Packet classification, metering, queuing, and scheduling using differentiated services (DiffServ) environment was the points in focus. To classify different types of real-time voice and multimedia traffic, the QoS provisioning mechanisms use different DiffServ code points (DSCP).The proposed algorithm is based on traffic classes which efficiently require the guarantee of services and specified level of fairness. In CBLLFQ, a mapping criterion and an efficient queuing mechanism for voice, video and other traffic in separate queues are used. It is proved, that the algorithm enhances the throughput and fairness along with a reduction in the delay and packet loss factors for smooth and worst traffic conditions. The results calculated through simulation show that the proposed calculations meet the QoS prerequisites efficiently.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1081-1086
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• 2023

The rapid growth and increasing complexity of modern networks have highlighted the limitations of traditional network architectures. The emergence of SDN (Software-Defined Network) in response to these challenges has changed the existing network environment. The SDN separates the control unit and the data unit, and adjusts the network operation using a centralized controller. However, this structure has also recently caused a huge amount of traffic due to the rapid spread of numerous Internet of Things (IoT) devices, which has not only slowed the transmission speed of the network but also made it difficult to ensure quality of service (QoS). Therefore, this paper proposes a method of load distribution by switching the IP and any server (processor) from the existing data processing scheduling technique, RR (Round-Robin), to mapping when a large amount of data flows in from a specific IP, that is, server overload and data loss.

• The KIPS Transactions:PartC
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• v.12C no.6 s.102
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• pp.901-906
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• 2005

In this paper, we propose a novel MHCOC (Mapped High Capacity Orthogonal Code) SS(Spread Spectrum) technique that reduces high PAPR (Peak power to Average Power Ratio) of HCOC SS system which was proposed to support high data rate transmission, and we compare to the conventional modulation technique such as MQAM SS that can transmit the same number of symbols at the same time. Moreover, we study on adaptation of this system to satisfy QoS (Quality of Service) that services the proper data rate according to the propagation channel quality information. We perform computer simulation to verify the performance of the proposed system and analyze its availability.

• Journal of Communications and Networks
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• v.12 no.6
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• pp.568-576
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• 2010

The paper presents a control architecture aimed at implementing bandwidth optimization combined with call admission control (CAC) over a digital video broadcasting (DVB) return channel satellite terminal (RCST) under quality of service (QoS) constraints. The approach can be applied in all cases where traffic flows, coming from a terrestrial portion of the network, are merged together within a single DVB flow, which is then forwarded over the satellite channel. The paper introduces the architecture of data and control plane of the RCST at layer 2. The data plane is composed of a set of traffic buffers served with a given bandwidth. The control plane proposed in this paper includes a layer 2 resource manager (L2RM), which is structured into decision makers (DM), one for each traffic buffer of the data plane. Each DM contains a virtual queue, which exactly duplicates the corresponding traffic buffer and performs the actions to compute the minimum bandwidth need to assure the QoS constraints. After computing the minimum bandwidth through a given algorithm (in this view the paper reports some schemes taken in the literature which may be applied), each DM communicates this bandwidth value to the L2RM, which allocates bandwidth to traffic buffers at the data plane. Real bandwidth allocations are driven by the information provided by the DMs. Bandwidth control is linked to a CAC scheme, which uses current bandwidth allocations and peak bandwidth of the call entering the network to decide admission. The performance evaluation is dedicated to show the efficiency of the proposed combined bandwidth allocation and CAC.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.11
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• pp.2793-2803
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• 2013

In H.264, three different data partition types are used, which have unequal importance to the reconstructed video quality. To improve the performance of H.264 video streaming transmission over IEEE 802.11e Wireless Local Area Networks, a prioritization mechanism that categorizes different partition types to different priority classes according to the calculated distortion within one Group of Pictures. In the proposed scheme, video streams have been encoded based on the H.264 codec with its data partition enabled. The dynamic scheduling scheme based on Enhanced Distributed Channel Access has been configured to differentiate the data partitions according to their distortion impact and the queue utilization ratio. Simulation results show that the proposed scheme improves the received video quality by 1dB in PSNR compared with the existing Enhanced Distributed Channel Access static mapping scheme.

• Journal of Communications and Networks
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• v.6 no.1
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• pp.46-59
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• 2004

In this paper, we present two algorithms for efficiently aggregating link state information needed for quality-of-service (QoS) routing. In these algorithms, each edge node in a group is mapped onto a node of a shufflenet or a node of a de Bruijn graph. By this mapping, the number of links for which state information is maintained becomes aN (a is an integer, N is the number of edge nodes) which is significantly smaller than N2 in the full-mesh approach. Our algorithms also can support asymmetric link state parameters which are common in practice, while many previous algorithms such as the spanning tree approach can be applied only to networks with symmetric link state parameters. Experimental results show that the performance of our shufflenet algorithm is close to that of the full-mesh approach in terms of the accuracy of bandwidth and delay information, with only a much smaller amount of information. On the other hand, although it is not as good as the shufflenet approach, the de Bruijn algorithm also performs far better than the star approach which is one of the most widely accepted schemes. The de Bruijn algorithm needs smaller computational complexity than most previous algorithms for asymmetric networks, including the shufflenet algorithm.