• Journal of Communications and Networks
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• v.12 no.1
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• pp.30-42
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• 2010

In this work we consider the problem of downlink resource allocation for proportional fairness of long term received rates of data users and quality of service for real time sessions in an OFDMA-based wireless system. The base station allocates available power and subchannels to individual users based on long term average received rates, quality of service (QoS) based rate constraints and channel conditions. We formulate and solve a joint bandwidth and power optimization problem, solving which provides a performance improvement with respect to existing resource allocation algorithms. We propose schemes for flat as well as frequency selective fading cases. Numerical evaluation results show that the proposed method provides better QoS to voice and video sessions while providing more and fair rates to data users in comparison with existing schemes.

• Journal of the Korea Society of Computer and Information
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• v.21 no.7
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• pp.17-22
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• 2016

In this paper we propose a novel QoE control scheme based on Service Level Agreement (SLA) which enables to guarantee the user perceived service quality of various high-quality mobile multimedia services such as mobile video streaming and real-time network games to a certain level. For this purpose, a SLA control structure is adopted to provision QoE, and a novel resource management scheme gets coupled with this control structure. Simulation results show that our proposed scheme can decrease the average delay and increase the total throughput by adjusting SLA.

• Journal of the Korea Society of Computer and Information
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• v.19 no.12
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• pp.81-89
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• 2014

The heterogeneous LTE-Advanced networks comprising a macrocell and femtocells can provide an efficient solution not only to extend macrocell coverage but also to deal with packet traffics increasing explosively within macrocells. Efficient resource management schemes are necessary to maintain the QoS requirements of versatile multimedia applications in LTE-Advanced networks because their service-continuity may be defected by some delay and information loss. In this paper, we propose a resource allocation method for the heterogeneous LTE-Advancedl networks overlaid with femtocells. Performances are analyzed by simulation.

• Journal of the Korea Society of Computer and Information
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• v.16 no.3
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• pp.157-165
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• 2011

The QoS management is an agreement of service user and service provider in B3G networks, and service provider must support proper the network service to service users by the agreement facts. The service provider must provide the QoS method to maintain the agreed service, which manages the detail method of system level from policy level. By the agreement of service policy, the service provider can give the QoS to the service customer with the service agreement. Hence, in this paper we propose a QoS mapping method of heterogeneous networks to provide the customer service through the service agreement based on the SLA of B3G networks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.2
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• pp.61-74
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• 2014

In recent years, development of femtocells are receiving considerable attention towards increasing the network coverage, capacity, and improvement in the quality of service for users. In 3GPP LTE-Advanced (LTE-A) system, to efficiently utilize the bandwidth, femtocell and macro cell uses the same frequency band, but this deployment poses a technical challenge of cross-tier interference to macro users. In this paper, the novel quality of service based fractional power control (QoS-FPC) scheme under the heterogeneous networks environment is proposed, which considers the users priority and QoS-requirements during the power allocation. The proposed QoS-FPC scheme has two focal points: firs, it protects the macrocell users uplink communication by limiting the cross-tier interference at eNB below a given threshold, and second, it ensures the optimization of femtocell users power allocation at each power adjustment phase. Performance gain is demonstrated with extensive system-level simulations to show that the proposed QoS-FPC scheme significantly decreases the cross-tier intereference and improves the overall users throughput.

• Journal of the Korea Society of Computer and Information
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• v.18 no.2
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• pp.59-68
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• 2013

Efficient resource management and hand-over schemes are necessary to maintain consistent QoS because it may be severely defected by some delay and information loss during hand-over in LTE-Advanced networks. This paper proposes a resource management scheme based on the load control to support consistent QoS for heterogeneous services during hand-over in OFDMA based systems. Various multimedia services with different requirements for resource are able to be serviced simultaneously because service continuity can be provided by our proposed scheme. Simulation results show that it provides better performances than the conventional one with the measure of hand-over failure rate and packet loss rate.

• The KIPS Transactions:PartC
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• v.13C no.7 s.110
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• pp.933-938
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• 2006

Different multimedia services over networks not only require different amounts of bandwidth but also have different Qualify of Service (QoS) requirements. For example, QoS guarantees for higher priority calls is an important issue in multimedia communication networks. In this paper, we develop an adaptive bandwidth management algorithm, which is able to provide QoS guarantees for higher priority calls while accommodating as many heterogeneous multimedia call connections as possible. Our scheme, based on reservation and bandwidth adaptation, manages bandwidth based on real time estimates of current network conditions. Simulation results indicate the superior performance of our scheme providing excellent trade off between contradictory requirements.

• Journal of Software Assessment and Valuation
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• v.15 no.2
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• pp.85-93
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• 2019

In an open, heterogeneous environment based on machine-to-machine (M2M) interactions, service selection is a critical issue and the concept of social trust can be applied to service selection so that IoT devices can make the best choice for interaction. In this paper, we propose a method for evaluating the trust level of the service and for estimating the QoS of the composite service using a profile created based on social trust relationship in IoT environment. As the service selection is made through quantitative evaluation, it is expected that the result of a more reliable service combination can be obtained.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.521-521
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• 2006

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.323-323
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• 2004