• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.3 s.345
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• pp.78-83
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• 2006

In this paper, we propose Active bandwidth allocation scheme of multiplexed streamed MPEG video sequences over BcN network. In order to real time processing, multiplexed source is estimated by linear-prediction per measurement period. n the result target quality value were not sufficient, we proposed a over-allocation method and a reallocation one to guarantee QoS. We used two kinds of sources, one is random multiplexed source made of four different video sources, the other is the one considered the arrange of I frame in the sequence. With those sources, we analyzed the linear prediction, compared over-allocation with reallocation method. As a result, In both schemes, the objected target quality value is achieved, the sufficient valuce bandwidth under 10% when measurement period is over 1.8 sec, the utilization is over 0.9. Especially, the Target of quality value of the reallocation scheme is better at the same condition.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.10B
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• pp.613-620
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• 2007

Recently, due to the developing of broadband convergence networks, the high quality multimedia services which are converged with communication and broadcasting can be provided. These high quality communication and broadcasting convergence service needs reliable multicasting mechanism in IP networks. However, multicasting mechanism recently deployed is difficult to guarantee the end-to-end QoS. For the reliable high quality If multimedia IPTV service, the QoS guaranteed multicasting mechanism should be provided. Therefore, we proposed a probing packet based multicasting admission control mechanism using centralized multicasting control management block in this paper. And for the performance evaluation of the proposed mechanism, we used ns-2 simulator.

• ETRI Journal
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• v.20 no.3
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• pp.251-271
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• 1998

It is well known that if usage parameter control/network parameter control (UPC/NPC) functions are used together with a cell loss priority control scheme in ATM networks, the measurement phasing problem can occur. This makes it difficult for a network provider to define and commit the cell loss ratio as a QoS parameter. To solve the problem, we propose a new UPC/NPC algorithm. By using the proposed UPC/NPC algorithm, we can define the cell loss ratios for CLP = 0 and CLP = 0+1 cell streams without the measurement phasing problem under any conditions. We analyzed the performance of the proposed UPC/NPC algorithm. Using a discrete time model for the UPC/NPC architecture with a discrete-time semi-Markov process (DSMP) input model, we obtained the cell discarding probabilities of CLP = 0 and CLP = 0+1 cells streams and showed that more CLP = 0 cells are accepted compared to what was proposed in ITU-T.

• ETRI Journal
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• v.26 no.1
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• pp.27-37
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• 2004

The architecture in a differentiated services (DiffServ) network is based on a simple model that applies a per-class service in the core node of the network. However, because the network behavior is simple, the network structure and provisioning is complicated. If a service provider wants dynamic provisioning or a better bandwidth guarantee, the differentiated services network must use a signaling protocol with QoS parameters or an admission control method. Unfortunately, these methods increase the complexity. To overcome the problems with complexity, we investigated scalable dynamic provisioning for admission control in DiffServ networks. We propose a new scalable $qDPM^2$ mechanism based on a centralized bandwidth broker and distributed measurement-based admission control and movable boundary bandwidth management to support heterogeneous QoS requirements in DiffServ networks.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.53-56
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• 2002

In this paper, we study the network structure that can guarantee the end-to-end quality of service in the Explicit multicast network. In order to guarantee the end-to-end quality of service, we adopt the end-to-end measurement based admission control (EMBAC) scheme. For the effective measurement of the network state and minimum influence on the current data traffic, the queue structure, which the drop precedence in assured forwarding (AF) Per hop behavior (PHB) of the differentiated service (Diffserv) is applied to, is proposed. Through a simulation, we show that EMBAC can make tile controlled load service in tile AF PHB applied Xcast network, and the qualify of the admitted traffic is guaranteed. In addition, the performance of the EMBAC is changing according to the selling parameter of AF PHB.

• KIISE Transactions on Computing Practices
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• v.23 no.5
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• pp.328-333
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• 2017

Mobile game apps, which are popular in various mobile devices, tend to be power-hungry and rapidly drain the device's battery. Since a long battery lifetime is a key design requirement of mobile devices, reducing the power consumption of mobile game apps has become an important research topic. In this paper, we investigate the power consumption characteristics of popular mobile games with multiple threads, focusing on the inter-thread. From our power measurement study of popular mobile game apps, we observed that some of these apps have abnormally high-load threads that barely affect the user's gaming experience, despite the high energy consumption. In order to reduce the wasted power from these abnormal threads, we propose a novel technique that detects such abnormal threads during run time and reduces their power consumption without degrading user experience. Our experimental results on an Android smartphone show that the proposed technique can reduce the energy consumption of mobile game apps by up to 58% without any negative impact on the user's gaming experience.

• Journal of the Korea Society of Computer and Information
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• v.20 no.3
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• pp.115-124
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• 2015

In this paper we analyse the previous (Quality of Services) and QoE(Quality of Experience) methods, and propose a high reliable network system framework and its service forwarding method that is able to provide seamless N-Screen services for proliferating disaster informations. The service satisfaction measurement, i.e., QoE, of contents consumers in N-screens services is going to be important the factor in disaster information proliferation because N-Screen services in the previous methods based on multi devices only focused on information transmission. The proposed system around these services is composed of a disaster information process framework for accepting user's service requirement, push service modules for minimizing the number of packets to be caused when carrying out the push service, and a push service controller for maximizing QoE measures. In order to provide a seamless N-Screen service on diverse screens, such as smartphone, PC, and big screen, we also have Open API(Application Programming Interface) functions. Through these results, we expect to evaluate QoS and QoE quality in the seamless N-Screen service.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.7B
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• pp.780-788
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• 2011

The lack of QoS (Quality of Service) support functionalities in IEEE 802.11 DCF mode makes it difficult to provide real-time multimedia services in WLANs. In this paper, we propose an effective available bandwidth measurement method in IEEE 802.11b DCF environments. The proposed method measures the total channel idle time and the collision probability during each measurement period. Then, the available bandwidth is calculated by considering those measured information and the transmission overheads at MAC and PRY layers. The performances of the proposed method are evaluated using OPNET simulator. The simulation results show that the proposed method provides more exact results than existing comparable schemes.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.1
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• pp.65-73
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• 2006

Network based VPN(Virtual Private Network) using MPLS(Multiprotocol Label Switching) technology, called PE(Provider Edge router) based MPLS VPN, is regarded as a good solution for intranets or ext3nets because of the low cost and the flexibility of the service provision. In this paper, we describe a mechanism that allows the VPN users to move from one site to another site of the VPN network based on the BGP-E MPLS technology. This mechanism is designed for PE(Provider Edge) routers of the backbone network. PE routers connected to the VPN sites establish a new MPLS path to the mobile node after they detect movement of the mobile VPN node. The new location may belong to the same VPN or to different VPN. We desisted VPN management and control functions of the PE routers in order to interface with the Mobile IP protocol and support the QoS mechanism. The pilot implementation and performance measurement were carried out on a simulation using COVERS tool.

• Journal of KIISE:Information Networking
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• v.34 no.2
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• pp.100-109
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• 2007

Streaming protocol with the Available Bandwidth measurement scheme has problems that are to measure a Available Bandwidth uncorrectly and slowly. In this basis, in order to overcome limitations of the previous streaming protocols, we propose the NABO that is a New Available Bandwidth measurement scheme used by OWD(One-Way Delay). Proposed NABO(New Available Bandwidth measurement based on OWD) measures the constant transmission delay occurred by bottleneck link capacity and the variable delay. Competing traffic contribute to the variable delay. Through the measurement of the constant transmission delay and the competing traffic, a NABO can measure the Available Bandwidth correctly and fast in network. The simulation result proves that the proposed NABO has a performance that satisfies both accuracy viewpoint and measurement speed viewpoint.