• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.126-129
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• 1998

In order to control the flow of traffics in ATM networks and optimize the usage of network resources, an efficient control mechanism is necessary to cope with congestion and prevent the degradation of network performance caused by congestion. This paper proposes a new UPC(Usage Parameter Control) mechanism that varies the token generation rate and the buffer threshold of leaky bucket by using a Neural Network controller observing input buffers and token pools, thus achieving the improvement of performance. Simulation results show that the proposed adaptive algorithm uses of network resources efficiently and satisfies QoS for the various kinds of traffics.

• Journal of information and communication convergence engineering
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• v.5 no.1
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• pp.54-58
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• 2007

A real-time frame-layer rate control algorithm with a token bucket traffic shaper is proposed for distortion variation minimization. The proposed rate control method uses a non-iterative optimization method for low computational complexity, and performs bit allocation at the frame level to minimize the average distortion over an entire sequence as well as variations in distortion between frames. The proposed algorithm does not produce time delay from encoding, and is suitable for real-time low-complexity video encoder. Experimental results indicate that the proposed control method provides better visual and PSNR performances than the existing rate control method.

• The KIPS Transactions:PartC
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• v.11C no.7 s.96
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• pp.951-958
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• 2004

Nowadays NGN is developed for supporting the e-Commerce, Internet trading, e-Government, e-mail, virtual-life and multimedia. Internet gives us the benefit of remote access to the information but causes the attacks that can break server and modify information. Since 2000 Nimda, Code Red Virus and DSoS attacks are spreaded in Internet. This attack programs make tremendous traffic packets on the Internet. In this paper, we designed and developed the Bandwidth Controller in the gateway systems against the bandwidth saturation attacks. This Bandwidth con-troller is implemented in hardware chipset(FPGA) Virtex II Pro which is produced by Xilinx and acts as a policing function. We reference the TBF(Token Bucket Filter) in Linux Kernel 2.4 and implemented this function in HDL(Hardware Description Language) Verilog. This HDL code is synthesized in hardware chipset and performs the gigabit traffic in real time. This policing function can throttle the traffic at the rate of band width controlling policy in bps speed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.4
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• pp.583-592
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• 1998

In this paper, the cell loss rate is analyzed in terms of the input traffic stream of different speed in ATM network. The cell loss rate is calculated by birth-death process of Leaky-Bucket mechanism as the representative algorithm of usage parameter control. The cell loss rate assumed 2-state MMPP input process to be birth-death process by considering the character of token pool about finite capacity queue. The results from numerical analysis show that the cell loss rate decreases abruptly according to the buffer size increase. The computer simulation by SIMSCRIPT II.5 has been done and compared with on/off input source case to verify the analysis results.

• The Transactions of the Korea Information Processing Society
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• v.6 no.10
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• pp.2779-2789
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• 1999

In this paper, we propose a new neural Buffered Leaky Bucket algorithm for preventing the degradation of network performance caused by congestion and dealing with the traffic congestion in ATM networks. We networks. We justify the validity of the suggested method through performance comparison in aspects of cell loss rate and mean transfer delay under a variety of traffic conditions requiring the different QoS(Quality of Service). also, the cell scheduling algorithms such as DWRR and DWEDF used for multiplexing the incoming traffics are induced to get the delay time of the traffics fairly. The network congestion information from cell scheduler is used to control the predicted traffic loss rate of Neural Leaky Bucket, and token generation rate is changed by the predicted values. The prediction of traffic loss rate by neural networks can effectively reduce the cell loss rate and the cell transfer delay of next incoming cells and be applied to other traffic control systems. Computer simulation results performed for traffic prediction show that QoSs of the various kinds of traffics are increased.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.469-471
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• 2005

최근 인터넷에서는 인터넷 방송, 화상 회의, VoIP 등 QoS 보장을 요구하는 새로운 응용 서비스들의 출현과 함께 IP QoS의 문제는 인터넷에서 가장 주요한 과제 중 하나로 등장하고 있다. 이러한 QoS의 적용은 가장 상용화 되어 있는 이더넷 망에서도 마찬가지로 적용되어야 하는 문제이다. 또한 사용자들은 SLA(Sonics Level Agreement)내에서 최선의 QoS 요구하게 되었다. QoS 보장을 위해 기존에는 통합 서비스(Integrated Service)나 차별화 서비스(Differentiated Service) 방식만을 사용하였으나 실제 적용하는데 구현상의 여러 문제점이 발견되었고, 대역폭 할당 방식에 있어서도 토큰 버킷(Token Bucket)과 같은 복잡한 방식을 사용하였다. 본 논문에서는 간단하면서 적용하기 쉬운 QoS 보장을 위한 멀티큐에서의 속도 계산(Rate Calculation)방식을 제안하며 OPNET을 통해 제안된 방식을 검증하도록 한다.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.11
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• pp.106-115
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• 1996

In this paper, the method using virtual scheduling suggested algorithm (VSSA) is suggested by considering cell delay variation and token rate of leaky bucket. This method is compared with virtual scheduling algorithm (VSA) and virtual scheduling algorithm with no tolerance excessive peak cell rate. As a result, the research shows that the usage parameter control using vSSA makes quality of service better than the usage parameter control using vSA or VSANT does because the suggested method reduces the violated cell probability of conformed peak cell rate and intentionally excessive peak cell rate.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.467-472
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• 2007

무선 센서네트워크는 다양한 환경에서 감시와 정보수집 역할을 수행하는 시스템이다. 최근에는 하드웨어의 발달로 무선 센서네트워크를 이용하여 멀티미디어 데이터를 수집하기 위한 시도가 활발히 이루어지고 있다. 본 논문에서는 센서네트워크에서의 신뢰성 있는 비동기적 이미지 전송 프로토콜인 RAIT를 제안한다. RAIT는 작은 크기의 메모리를 갖는 센서노드의 특징을 고려하여 전송 중 발생하는 Overflew의 방지를 위하여 Token-Bucket 방식으로의 네트워크 트래픽 관리를 통해 이미지 전송의 신뢰성을 높인다. 또한 시뮬레이션 결과를 통해 RAIT의 이미지 전송 신뢰성을 확인하였다.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.2
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• pp.23-31
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• 1996

This paper proposes a new UPC(usage parameter control) mechanism that varies the token generation rate of leaky bucket by observing virtual buffer, thus achieving an improvement of performance. An acceptance of a call in B-ISDN is determined by call admission control. A UPC that polices the agreed traffic parameters of a call and takes appropriate actions to prevent congestion in networks. The cell loss probability of conventional UPC is far from that of ideal UPC. The proposed mechanism has a better policing ability and response time for nonconforming call. The proposed mechanism uses ON-OFF model as input traffic. The results of simulation show the efficiency of the proposed mechanism.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04a
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• pp.310-312
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• 2000

명시적인 자원 할당과 스케줄링에 의해 QoS를 제공 할 수 있는 방안으로 RSVP가 제안되었으나 내부 구조 변경이나 확장성의 문제를 내포하고 있다. 그래서 IETF에서는 차등 서비스(Differentiated Service)를 이용하여 서비스 영역을 확장하려는 연구가 활발히 진행중이다. DiffServ는 확장성을 고려하여 RSVP와 같은 개별 flow에 대한 QoS 제공이 아닌 flow들의 집합(aggregated)으로 차등적인 서비스를 제공하는 방법이다. 본 논문에서는 aggregated flow로 서비스를 제공할 때 불특정 flow에 대한 QoS 손실을 막기 위해 Token Bucket Meter 처리 전에 사전 모니터링에 의해 자원공유의 공정성과 처리 속도를 향상시킬 수 있는 TC(Traffic Conditioner)를 설계, 구현하여 다수 subnetwork에서의 flow가 자원을 공정하게 공유함을 결과로 보였다.