• The Transactions of the Korea Information Processing Society
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• v.6 no.8
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• pp.2042-2049
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• 1999

In contrast to traditional data communication, the multimedia communication must support variable requirements to multimedia application service. Specially, it is a critical issue that the synchronization supports a continuous and temporal relationship media playout in a distributed environment. But the continuously generated media in source can't guarantee the constant interval on playout for the destination due to the inconsistent network transmission delay and transmission error. In this paper, we introduce a intramedia synchronization mechanism for the continuous and synchronous playout of multimedia stream such as audio and video across a communication network. The proposed mechanism is based on the user defined QoS(Quality of Service) and the playout correction algorithm to guarantee the continuous media playout at the receiver.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.5A
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• pp.417-425
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• 2005

KOINONIA is high-rate Wireless Personal Area Network (WPAN) technology, and is developed for multimedia traffic transmission in personal area. A KOINONIA piconet is a collection of one or more associated slaves under a single master. Efficient scheduling of a master for the traffic of slaves is essential to use channel effectively and to guarantee QoS of multimedia traffic. We propose a new scheduling algorithm to allocate channel time at desired intervals regardless of superframe length, and a Connection Admission Control(CAC) algorithm to regulate the number of traffics in a piconet. Our proposed algorithms have been shown to save channel time and to meet QoS requirements compared to the conventional weighted round-robin algorithm.

• Journal of KIISE
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• v.42 no.11
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• pp.1423-1429
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• 2015

The Internet of Things (IoT) is a new concept associated with the future Internet, and it has recently become a popular concept to build a dynamic, global network infrastructure. However, the deployment of IoT creates difficulties in satisfying different Quality of Service (QoS) requirements and achieving rapid service composition and deployment. In this paper, we propose a new QoS control scheme for IoT systems. The Markov game model is applied in our proposed scheme to effectively allocate IoT resources while maximizing system performance. The results of our study are validated by running a simulation to prove that the proposed scheme can promptly evaluate current IoT situations and select the best action. Thus, our scheme approximates the optimum system performance.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.390-392
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• 2011

Energy saving mechanism is very important in a battery-powered wireless sensor networks. In this paper we derived the energy consumption model of each sensor node and the conditions of proving the QoS requirements. Through the analysis of energy consumption of each sensor node, we suggest the method to prolong lifetime of WSNs.

• Journal of IKEEE
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• v.11 no.4
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• pp.171-177
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• 2007

Although the Distributed Coordination Function is the fundamental access protocol of IEEE 802.11, it cannot meet the Quality of Service (QoS) requirements in general. So, the Point Coordinate Function is provided to support QoS related services. However, it has inherent problems. Access point (AP) has no knowledge of the queue status and instantaneous channel condition of stations in the system. In this paper we propose an efficient and versatile polling scheduler that shows excellent throughput and fairness performance. Comparison with well known polling schemes is provided through computer simulation under various channel situations including error prone environments.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.113-116
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• 2001

Reed-Solomon(RS) code is the most powerful burst error correcting code. In Ois paper, the architecture for the adaptive RS encoder adaptable for multi QoS requirements or time-varying channel environments has been designed. In the adaptive RS code, the message length k and the error correction capability t are allowed to be variable so that the block length n is also variable. We proposed the architecture of the adaptive RS encoder by designing the optimal structure of Galois fields multiplier with comparison of fixed multiplier and variable multiplier. The proposed architecture is implemented in VHDL and verified with the simulation tool

• 한국HCI학회:학술대회논문집
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• 2008.02c
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• pp.12-18
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• 2008

This paper introduces the existing network-adaptive transport techniques for haptic-enhanced system. First we classify haptic-based network systems according to the communication architecture and data type. Then the existing studies concerning network QoS requirements for haptic-based network system are depicted. Finally, the survey of network-adaptive transport schemes is introduced devided into three key issues: delay and jitter compensation, error control, and transmission control.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5B
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• pp.498-508
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• 2009

In wireless mobile environments, large bandwidth and high QoS (Quality of Service) are recently required to support the increased demands for multimedia services. LTE (Long Term Evolution) is one of the promising solutions for the next generation broadband wireless access systems. To efficiently use downlink resource and effectively support QoS, packet scheduling algorithm is one of the important features in LTE system. In this paper, we proposed DAPS (Delay-Aware Packet Scheduling) algorithm to consider QoS requirements of delays for various traffic classes as well as channel condition and fairness. To reflect delay experiences at scheduling instance, DAPS observes how queue waiting time of packet is closed to maximum allowable delay. The simulation results show that the DAPS algorithm yields better performance for delay experience by increasing the number of transmitted packets with satisfying the required delay time compared with existing scheduling algorithms.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.12
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• pp.106-115
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• 2003

Diverse multimedia services will be deployed at hand on 3G-and-beyond multi-service CDMA systems in order to satisfy different quality of service (QoS) according to traffic types. In order to use appropriate resources efficiently the call admission control (CAC) as a major resource control mechanism needs to be used to take care of efficient utilization of limited resources. In this paper, we propose a QoS-aware CAC (QCAC) that is enabled to provide service fairness and service differentiation in accordance with priority order and that applies the different thresholds in received power considering different QoS requirements such as different bit error rates (BER) when adopting total received power as the ceil load estimation. The proposed QCAC calculates the different thresholds of the different traffic types based on different required BER applies it for admission policy, and can get service fairness and differentiation in terms of call dropping probability as a main performance metric. The QCAC is aware of the QoS requirement per traffic type and allows admission discrimination according to traffic types in order to minimize the probability of QoS violation. Also the CAC needs to consider the resource allocation schemes such as complete sharing (CS), complete partitioning (CP), and priority sharing(PS) in order to provide fairness and service differentiation among traffic types. Among them, PS is closely related with the proposed QCAC having differently calculated threshold per each traffic type according to traffic priority orders.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.1
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• pp.1-10
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• 2012

Mobility and quality of service (QoS) are becoming the more important issues in wireless communications. The traditional Internet service is expanding into new access media and applications. Since wireless communication services are accompanied by frequent handovers at remote sites, scalable and fast handover has become a prerequisite for ubiquitous communication. In this paper, the differentiated service (Diffserv) model is deployed in heterogeneous proxy mobile IPv6 (PMIPv6) networks to satisfy the QoS guaranteed service and fast handover requirements. The operational procedures for QoS guaranteed global roaming are presented. In addition, QoS management and handover cost evaluation schemes based on a mobile host's movement scope are proposed. This paper analyzes the reduction in handover delay in a network-based localized mobility management framework. We propose and analyze a PMIPv6 optimized with a global mobile access gateway (G-MAG), which is a network-based entity, to further improve the handover performance in terms of handover delay while maintaining minimal signaling overhead in the air interface among converged heterogeneous wireless networks. The handover signaling procedures with host-based MIPv6 are compared with network-based proxy MIPv6 (PMIPv6) and fast PMIPv6 assisted by G-MAG to show how much handover delay reduction can be achieved. Analytical results show that the handover delay is significantly reduced.