• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.1A
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• pp.30-37
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• 2006

In this paper, we propose a QoS-aware efficient bandwidth re-provisioning scheme in a next generation wireless packet transport network. At the transport network layer, it classifies the traffic of the radio network layer into a real time class and a non-real time class. Using an auto-regressive time-series model and a given packet loss probability, our scheme predicts the needed bandwidth of the non-real time class at every re-provisioning interval. Our scheme increases the system capacity by releasing the unutilized bandwidth of the non-real time traffic class for the real-time traffic class while insuring a controllable upper bound on the packet loss probability of a non-real time traffic class. Through empirical evaluations using the real Internet traffic traces, our scheme is validated that it can increase the bandwidth efficiency while guaranteeing the quality of service requirements of the non-real time traffic class.

• The Journal of the Korea Contents Association
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• v.8 no.1
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• pp.169-176
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• 2008

In this paper, we develop radio resource management queueing model in IEEE 802.IS networks considering both connection and packet level. In the upper level connection, we model connection admission control depending on availability of bandwidth and priority queue in each service class. In the lower level packet, we model dynamic bandwidth allocation considering threshold and availability of bandwidth in each service class simultaneously. Hierarchical model is built using an extended Petri Nets, SRN (Stochastic Reward Nets). Bandwidth utilization and normal throughput as performance index for all service classes of traffic are calculated and numerical results are obtained.

• Journal of Korea Multimedia Society
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• v.13 no.3
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• pp.349-358
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• 2010

Adaptability is an important issue in video streaming over mobile environments, since the clients may request videos with great differences in their workload. In this paper, we propose the issues in limited bandwidth scheduling for efficient MPEG-4 video stream transmission over a mobile or wireless network. In the phase of admission control, the amount of bandwidth allocated to serve a video request is the mean bandwidth requirement of its requested video. The dynamic allocation of bandwidth in the phase of scheduling depends on the playback buffer levels of the clients with an objective to make it more adaptive to the playback situation of individual clients. In the proposed RTA scheduling protocol, more bandwidth may be allocated temporarily to the client whose buffer level is low. By employing the buffer level based scheduling policy, this protocol attempts to maximize the real-time performance of individual playback while minimizing the impact of transient overloading. Extensive simulation experiments have been performed to investigate the performance characteristics of the RTA protocol as comparing with BSBA protocol. This RTA protocol shows the better performance by transferring more frames than BSBA protocol.Computer simulations reveals that the standard deviation of the bit rate error of the proposed scheme is 50% less than that of the conventional method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.747-748
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• 2013

This paper proposes a new dynamic polling method for XGPON1 (10-Gbps-capable passive optical network stage 1). XGPON1 system supports 2.5 Gbps for upstream and 10 Gbps for downstream. In XGPON1 system, if the polling frequency is high, then the efficiency of dynamic bandwidth allocation increases whereas the upstream bandwidth is wasted. The proposed method decreases the upstream bandwidth wastage owing to polling and efficiently increases the polling frequency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.9A
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• pp.1563-1573
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• 2001

본 논문에서는 무선 ATM 망에서 멀티 서비스 클래스를 지원하기 위하여 핸드오프로 인한 이동 특성과 호 수준의 QoS를 고려한 동적 무선 자원 관리 기법을 제안하였다. 제안한 기법은 무선 자원을 우선적으로 핸드오프 호에게 할당하고 새로운 호에게도 서비스 확률에 의하여 동적으로 자원을 할당하도록 한다. 서비스 확률은 전체 무선 대역폭, 임계값, 사용중인 무선 대역폭, 이동 특성, 그리고 서비스 클래스별 조정값을 이용하여 동적으로 결정된다. 또한 제안한 기법의 성능을 평가하기 위해 수학적 분석을 실시하였고 핸드오프 호의 강제 종료 확률, 새로운 호의 블록킹 확률, 자원 이용률 관점에서 기존의 기법과 비교하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.139-143
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• 2001

무선 ATM망에서는 무신 접속으로 인하여 단말의 이동성이 발생하는데, 단말기는 이동 중에도 호의 끊김 없이 QoS를 보장하면서 연속적인 서비스를 제공받을 수 있어야 한다. 사용자 및 이동성의 증가와 작아지는 셀 크기로 인하여 핸드오버는 빈번해 질 것이다. 무선 ATM망에서 핸드오버 발생시 멀티미디어 서비스를 제공하기 위해서는 한정된 무선 대역폭을 인접 셀에 해당대역폭을 예약하는 것이 주류를 이루었다. 그러나 이동 단말기의 이동 방향을 알지 못함으로써 불특정 다수의 셀에 대역폭을 예약하는 깃이 문제점으로 지적되었다. 그래서 이동 단말기의 이동 방향을 추정하여 추정된 셀에만 대역폭을 예약하는 방법을 제안하게 되었다. 본 논문에서는 Fuzzy 이론을 이용하여 이동 방향을 추징하여 추정된 셀에만 대역폭을 예약하는 방법을 사용하여 시뮬레이션을 통해 이전의 알고리즘과 QoS 성능을 분석하였다.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.137-137
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• 2004

• Journal of the Institute of Convergence Signal Processing
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• v.13 no.2
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• pp.99-105
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• 2012

The focus of this paper is a proposal for a computationally efficient dynamic subcarrier allocation (DSA) algorithm for orthogonal frequency-division multiple access (OFDMA) systems. The proposed DSA algorithm considerably reduces the computational complexity and the amount of channel quality information (CQI) compared to amplitude craving greedy (ACG) algorithms, which use full CQI. At the same time, the performance of the proposed algorithm closely appear to ACG algorithms. Moreover, the authors present a new bandwidth-assignment algorithm produced by modifying bandwidth assignment based on the signal-to-noise ratio (BABS). This modified BABS algorithm enables the proposed DSA algorithm to produce a strong outage performance gain over the conventional scheme.

• Journal of Digital Contents Society
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• v.18 no.2
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• pp.411-422
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• 2017

Current policies for sharing bandwidth increase average throughput and improve utilization of the bandwidth in the local network. However, with these policies, a central administer, which is responsible for allocating bandwidth to each network flow, cannot allocate resources based on user characteristics. Thus, it leads to unfair bandwidth allocation because it does not guarantee services based on user characteristics. Therefore, we propose a novel negotiation method to share the bandwidth in a limited bandwidth network, in which, a user negotiates with other users to gain more resource. Ideally, we use a fuzzy system to infer and determine whether a device will request bandwidth or not based on the current usage of the given device. We conduct two experiments consisting of a video streaming simulation in OPNET and a real-time video streaming in WebRTC. The results of the experiment indicate that the proposed method can flexibly share the bandwidth utilization based on user's requirement in the network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.9A
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• pp.1525-1534
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• 2001

국내 통신사업자들이 xDSL 등 초고속 인터넷 액세스 서비스를 왜곡된 요금구조로 경쟁적으로 보급함에 따라 급속히 확산되고 있으나, 엄밀히 원가를 감안한다면 여전히 AO/DI는 인터넷 트래픽 폭증으로 인한 전기통신망의 과부하를 통신사업자가 경제적이며 효과적으로 대처할 수 있는 현실적인 대안이라 할 수 있다. 본 논문은 AO/DI의 동적 채널 할당 및 해지에 있어서 VIA가 권고한 정책보다 효율적으로 대역폭을 할당, 해지할 수 있는 알고리즘을 제안한다. 관찰 시점까지의 누적된 트래픽의 양과 변화를 감안하여 평균 트래픽과 분산을 추정함으로써 트래픽의 변화에 적응하여 채널 할당, 해지 시점을 결정할 수 있으며 트래픽 특성에 따라 매개 변수의 조정을 통하여 D 채널, B 채널의 이용률을 제어할 수 있고 평균 대기시간 등의 성능을 최적화할 수 있음을 보인다. 또한, 이를 기초로 응용 프로토콜을 감지하여 응용이 갖는 고유의 트래픽 특성과 요구사항에 적합한 채널 할당/해지 방안도 제시한다.