• The Journal of the Korea Contents Association
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• v.10 no.4
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• pp.45-54
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• 2010

In this paper, we propose a quality interworking control system to enhance user's quality satisfaction in NGN environment by controling QoS parameters related with QoE in network layer when service user's QoE using variance multimedia service is poor. The proposed system gathers QoS parameter information in network layer through control packet such as RTCP, and evaluates QoE of multimedia service using these QoS parameter information. Comparing the evaluated QoE with the measured QoE in application layer, QCS judges quality degradation, deduces related QoS parameters and decides relative importance of each parameter when QoE is lower than threshold value. QCS generates QoS control values which is based on routing and switching policy in service quality control system(SCS) and forwards them to SCS. Through this proposed system, service and network providers can provide multimedia services of enhanced quality to service users taking account of service characteristic and network performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.2
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• pp.327-346
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• 2013

Researchers as well as network providers are increasingly interested in understanding how a network user's experience changes in relation to different quality of service (QoS) parameters, with many attempts being made to identify the general relationship between quality of experience (QoE) and QoS. Several relations in different function forms have been proposed. There are instances when this variety of proposed functions potentially results in one problem having completely dissimilar solutions at the same time. The question then is which function form is the one that can better explain this relationship. In this paper, three major existing quantitative relationships between QoE and QoS are investigated. After conducting a comprehensive comparative analysis between them, a new definition of QoE-QoS dependency appears. It then results in identifying a new mutual relationship between QoE and QoS. The newly proposed relationship improves the deficiency of previous QoE-QoS relationships along with solving the problem of diversity of simultaneous solutions for one problem.

• Journal of Advanced Navigation Technology
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• v.14 no.4
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• pp.530-536
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• 2010

This paper proposes a QoS/QoE guaranteeing scheme by reassembling packets that have already been delivered to the end systems under the condition that there is no other way to fulfill user's QoS/QoE with the current network conditions. The proposed scheme is a QoS/QoE provisioning scheme that can be applied when IPTV streaming packets have not been consecutively received by the receiver. The receiving end system modifies the continuous counter field in the MPEG-2 Transport Stream and reassembles packets based on this information. In the simulation, broadcasting streaming environment has been implemented in order to verity the QoS/QoE performance of the proposed scheme under the good and poor network conditions.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.320-325
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• 2009

네트워크 서비스에 있어서 품질을 정확히 측정하고 품질지수를 도출하는 것은 매우 중요하다. 종래의 네트워크 서비스에 대한 품질지수는 QoS(Quality of Service)로서 많은 연구가 있어왔다. 하지만 QosS를 통한 사용자 품질지수는 실제 사용자의 서비스 만족도를 효과적으로 표현해 주지 못하였다. 그래서 본 연구에서는 QoE(Quality of Experience)라는 개념을 도입하여, 사용자가 실제로 느낀 서비스의 만족도를 도출하고자 하였다. 사용자의 서비스 만족도를 잘 표현해주는 QoE를 도출하기 위하여 본 연구에서는 QoE Framework를 제안한다. QoE Framework는 framework를 위해 동작하는 agent들로 구성된다. QoE Framework의 agent는 크게 서비스 제공자측과 서비스 사용자 측으로 나눌 수 있는데, 서비스 사용자 측의 agent는 서비스를 이용하다가 사용자가 서비스 불만족을 감지하였을 때, 서비스 제공자측 agent는 사용자측 agent로부터 받은 서비스 불만족에 대한 feedback으로부터 QoE도출 알고리즘을 사용하여 최적의 QoE를 도출하는 기능을 한다. 서비스 제공자측 agent의 QoE도출 알고리즘으로 GA(Genetic Algorithm)을 사용하여 최적의 값을 구하게 된다. QoE framework의 알고리즘에서는 불만족 feedbaek을 이루는 QoS 파라미터들간의 중요도와 관계를 도출하여, 주어진 서비스 개선 비용으로 최적의 QoE를 도출함으로써, 네트워크 서비스에 대한 사용자의 만족도를 최대로 높이는 결과를 도출하게 된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.11
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• pp.5392-5418
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• 2017

The primary aim of this paper is to propose a non-linear regression based technique for mapping different network Quality of Service (QoS) factors to an integrated end-user Quality of Experience (QoE) or Mean Opinion Score (MOS) value for an online video streaming service on a mobile phone. We use six network QoS factors for finding out the user QoE. The contribution of this paper is threefold. First, we investigate the impact of the network QoS factors on the perceived video quality. Next, we perform an individual mapping of the significant network QoS parameters obtained in stage 1 to the user QoE based upon a non-linear regression method. The optimal QoS to QoE mapping function is chosen based upon a decision variable. In the final stage, we evaluate the integrated QoE of the system by taking the combined effect of all the QoS factors considered. Extensive subjective tests comprising of over 50 people across a wide variety of video contents encoded with H.265/HEVC and VP9 codec have been conducted in order to gather the actual MOS data for the purpose of QoS to QoE mapping. Our proposed hybrid model has been validated against unseen data and reveals good prediction accuracy.

• Journal of KIISE:Information Networking
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• v.41 no.4
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• pp.151-166
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• 2014

The present method of measuring QoE (Quality of Experience) was to measure the whole block from the server that provides service to the terminal that the client gets the service. In this way, it was possible to simply determine whether the quality of QoE was good or not, and when the quality of QoE became bad, there was no way of presenting solutions. Also, as QoE metrics are numerous, there has been no strict regulation on how to use. This study analyzed QoE metrics in the viewpoints of network and clients, subdivided the whole service into three phases including one from the server providing the service to the router, another from the router to the terminal getting the service, and the third from the service router to the client router, and presented QoE metric frames appropriate for each phase. Through this, in the KOREN-CERNET environment, this study designed and embodied QoE network and demonstrated stability of QoE network, reduction in client complaint settlement time, and content adjustment effect according to the network change.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.9 no.1
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• pp.24-28
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• 2010

The Quality of Experience (QoE) of next Generation wired/wireless network services based upon IP networking is becoming a popular issue in recent years. The user experience of Internet services such as IPTV, online game, web surfing and etc, are becoming the most desirable factors to service providers to improve service performance and customer's satisfaction. However, collecting user experience from customers and obtaining the QoE parameters from the Quality of Service (QoS) parameters such as bandwidth, delay, jitter or admission control algorithm, are difficult subjects because of the various service types and user characteristics. In this paper, we propose a framework which contains service classification, QoE analysis and service enhancement steps for a suitable QoE measurement and management protocol. We define the user satisfaction indicators of the Internet services, classify the categories of each type of services, and analyse the Key Performance Indicator (KPI) in each type of services to perform the QoS parameters and improving the service qualities.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.5B
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• pp.451-463
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• 2011

QoE is defined as a quality perceived by users on a certain service. However, standard method to measure voice QoE(MOS) has been developed, but no standard method to measure video QoE has been defined. In this paper, we propose an efficient algorithm to measure video QoE s automatically for IPTV services. The proposed method selects candidate scenarios that affect the users' MOS directly, and derives weight factors for the selected scenarios. With the weight factors for the scenarios, video QoE value is calculated. For the validation of the proposed algorithm, we made degraded videos reflecting the parameters. With the degraded videos, by comparing the user perceived MOSs with the video QoEs derived by the proposed algorithm, we show that the two values are highly correlated each other.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.702-704
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• 2010

Wireless LAN(Local Area Network) environment to support QoS in IEEE802.11 Working Group has standardized on the IEEE 802.11e. IEEE 802.11e EDCA channel access of the high priority traffic as by raising the probability of a chance to support QoS. This is a high priority traffic than low priority traffic, channel access is not necessarily the first. Therefore, as all traffic channels, if you have the same routing path, lower priority traffic on the performance of high priority traffic, sustainable impact. As a result, EDCA, such as voice or video to guarantee QoS for multimedia applications, follow the crowd. In this paper, to solve these problems by using Multi-Interface Multi-Path Routing Algorithm is proposed. Interface for each use in IEEE 802.11e EDCA Access Category much differently by each of the Routing Path for high priority traffic and guarantee QoS.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.221-224
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• 2004

최근 무선 랜의 상용화에 따른 다양한 어플리케이션들이 제공되고 있다. 이 중 대용량 멀티미디어 트래픽을 사용한 다양한 서비스가 제공되고 있는데, 이들에 대한 QoS 보장을 위한 다양한 기법들이 세안되고 있다. 기존의 802.11에서는 CSDP 스케줄러를 이용하여 각각의 MH로 보내지는 데이터에 대한 QoS를 보장하기 위해 노력하였고, WG(Working Group) e가 만들어지면서 보다 상세하게 데이터 트래픽에 대한 QoS를 더 연구하게 되었다. 본 논문에서 제안하고자 하는 스케줄러는 IEEE 802.11에 CSDP (Channel State Dependent Packet) 스케줄러의 LSM(Link State Monitoring)의 개념과 IEEE 802.11e에서 제안하고 있는 EDCA (Enhanced Distributed Channel Access)방식과 HCCA (HCF Controlled Channel Access) 방식이 결합되어 있는 스케줄러에 실제 스케줄링이 이루어지는 PHY Queue에 가기 전 대기하는 Queue에 가상 큐를 적용하여 트레픽 특성을 고려하고, bad가 발생하는 링크로 가는 트래픽에 대해서는 임시 큐에 저장한 후에 링크가 good 상태가 되면 전송함으로써 보다 높은 QoS를 제공하며, 전체 시스템의 효율을 향상시키는 스케줄러를 제안하고자 한다.