• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.43-48
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• 2004

RTP that is proposed supplement of real-time services on internet environment, as Real-time Transport Protocol, is the protocol that for the purpose of sending data of stream type. RTP and RTCP(Real-time Transport Control Protocol) basically work at the same time, RTCP serves with state information of network at present. RTP has important properties of a transport protocol that runs on end-to-end systems and provides demultiplexing. It also offer reliability and protocol-defined flow／congestion control that transport protocol like TCP can not provides. In this paper, we look around concept and construction of Differentiated sen1ice tint run on RTP and by setting parameters of packet transfer method be used CBQ(Class-Based Queuing) for packet transfer on Differentiated service, each service queue controls properly through packet scheduling method, such as WRR(Weighted Round Robin) and PRR(Packet-by-packet Round Robin) all service classes do not experience the starvation and confirm the performance through computer simulation to achieve fairly scheduling.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.6
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• pp.225-236
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• 2003

In this paper, we propose a wireless scheduling algorithm to provide the Internet delay proportional differentiated services in wireless networks. For considering network environments that have burst and location-dependent channel errors, our proposed WDPS(Wireless Delay Proportional Service) scheduling algorithm adaptively serves packets in class queues based on the delivered delay performance for each class. The remarkable characteristics of WDPS scheduler are supporting a fair relative delay service, providing graceful throughput and delay compensation, and avoiding class queue blocking problem. Through simulations, we show that the algorithm achieves the desirable properties to provide delay proportional services in wireless networks.

• Journal of Communications and Networks
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• v.7 no.3
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• pp.377-384
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• 2005

The purpose of this research is to develop and evaluate a traffic engineering architecture that uses local state information. This architecture is applied to an Internet protocol radio access network (RAN) that uses multi-protocol label switching (MPLS) and differentiated services to support mobile hosts. We assume mobility support is provided by a protocol such as the hierarchical mobile Internet protocol. The traffic engineering architecture is router based-meaning that routers on the edges of the network make the decisions onto which paths to place admitted traffic. We propose an algorithm that supports the architecture and uses local network state in order to function. The goal of the architecture is to provide an inexpensive and fast method to reduce network congestion while increasing the quality of service (QoS) level when compared to traditional routing and traffic engineering techniques. We use a number of different mobility scenarios and a mix of different types of traffic to evaluate our architecture and algorithm. We use the network simulator ns-2 as the core of our simulation environment. Around this core we built a system of pre-simulation, during simulation, and post-processing software that enabled us to simulate our traffic engineering architecture with only very minimal changes to the core ns-2 software. Our simulation environment supports a number of different mobility scenarios and a mix of different types of traffic to evaluate our architecture and algorithm.

• Proceedings of the Korea Contents Association Conference
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• 2003.11a
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• pp.227-233
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• 2003

In paper, we present design and implementation of MPLS based VPN with QoS capabilities. We propose a design architecture of an edge router for MPLS based VPN with QoS capabilities in backbone network. We design functional blocks, interface specifications, detail routing and forwarding information based structure, and packet forwarding engine for the purpose of implementation of an edge router, We extend bgp-4 software for implementation differentiated service packet forwarding schemes in MPLS based VPN.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.421-423
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• 2001

본 논문은 IETF에서 제안한 차등화서비스모델(Differentiated Service Model)을 지원하는 라우터를 리눅스상에 구현하였다. 구현한 라우터는 기존의 리눅스에서 지원하는 에지 라우터의 단점을 개선하기 위하여 구현한 ingress marker를 사용하였다. 구현된 ingress marker는 AF 클래스의 트래픽을 미터링하고 마킹하기 위해 사용되는 trTCM을 포함하고 있으며, 이 ingress marker를 사용한 에지 라우터는 병목이 발생한 경우에도 각 클래스간 독립적으로 서비스를 보장해 줄 수 있다. 각 클래스간 성능보장은 AF PHB를 통해 기존 라우터와 비교 실험하여 검증하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.8C
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• pp.758-770
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• 2002

In this paper, we propose a novel resource allocation scheme which can maximize capacity for QoS guarantee of Assured Service in Differentiated Services. Performance of the proposed resource allocation scheme is analyzed with each buffer management scheme such as RIO and Adaptive RIO. To prevent an early random drop of the admitted In-profile packet, Adaptive RIO scheme updates parameters of RIO scheme every time interval according to the estimated numbers of maximum packet arrivals of In-profile traffic and Out-of-profile traffic during the next time interval. The numbers of maximum packet arrivals during the next time interval are estimated based on the buffer size determined by the network topology and the ratio of bandwidth allocated to each subclass. We can find from simulation results that proposed resource allocation scheme with Adaptive RIO can guarantee QoS and can maximize capacity for Assured Service.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.6
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• pp.672-686
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• 2002

현재 단대단(End-to-End) 비디오 서비스의 질을 높이기 위해 많은 연구가 각 계층별로 진행되고 있다. 전송계층에서의 오류 제어(Error Control), 네트워크계층에서의 QoS (Quality of Service)모델, 표현 및 응용계층에서의 오류 강인성(Error resilience)/오류 은닉(Error concealment) 등이 연구 개발되고 있다. 그러나 계층 간의 연관성이 높은 부분에서의 통합을 통한 성능향상에 관한 연구는 그 필요성과 효율에 비해 아직도 미흡하다. 본 논문은 QoS 서비스 모델하에서의 적응적 FEC(Forward Error Correction) 적용 및 우선순위에 따른 비디오패킷(VP ,VideoPacket)을 통하여 효율적인 계층화 비디오 스트리밍을 단대단 QoS성능의 향상에 관점을 맞추어 제안한다. 제안하는 방식은 최소 화질 보장과 같은 효율에서 보다 적은 가격에서의 서비스를 제공할 수 있다. 이를 위하여 통합형 서비스(IntServ, IS, Integrated Service) 의 자원예약을 사용하는 방법과 높은 가격의 자원 예약을 사용하지 않는 차별화 서비스(DiffServ, DS, Differentiated Service)를 적용했으며 이에 보장형 서비스의 특징을 공통을 가지기 위해 계층화 FEC를 적용하였으며 적절한 가격의 조절을 위하여 비디오패킷을 통한 데이터 분할을 적용하였다. 본 논문은 또한 최종 사용자의 만족도를 PSNR(Picture Signal to Noise Ration)과 PSNR에서 표현하지 못하는 부분의 평가를 위해 손상프레임율(DFR, Damaged Frame Ratio)과 오류프레임율(EFR,Error Frame Ratio)을 제안 이를 통해 평가하고자 한다. 제안하는 방식의 실험 결과는 비디오 코딩계층과 전송 계층, 네트워크 계층의 결합된 성능이며 이는 또한 화질의 개선뿐만 아니라 사용자의 가격문제에 대하여서도 비교 분석하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.2078-2083
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• 2012

Tactical communication environment evolving for the purpose of providing services such as voice, video and text based on ALL-IP. Therefore, To be able to guarantee QoS level which meets the required level of subscriber for these services in the constrained tactical communication infrastructure, it is required to take the characteristics such as wireless transmission link, mobility of troops or personal into service quality scheme. In this paper, to support differentiated QoS for each individual or mission in the tactical communication environment, we presents a technique that can provide same QoS level which was served originally regardless of the situation to user's move through dynamically determining the QoS level to be provided at the time of the service request on VoIP-Switch.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.649-652
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• 2015

Previous marking policy for the AF service of TCP traffic in the Diffserv network have no sufficient consideration on the effect of RTT and target rate. In this paper, in order to improve fairness Index by the effect RTT difference of TCP traffic, we propose the modified TSW3CDM(Time Sliding Window Three Color Dynamic Marker) based on average transfer rate estimation and the flow state. The proposed algorithm is dynamic marking policy that do allocate band width in proportion to transmission rate. To evaluate the performance of the proposed algorithm, We accomplished a computer simulation using NS-2. From simulation results, the proposed TSW3CDM algorithm improves fairness index by comparison with TSW3CM.

• Journal of the Korea Society of Computer and Information
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• v.6 no.4
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• pp.74-84
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• 2001

In the current Internet, InteServ model based on Resource reSerVation Protocol (RSVP), DiffServ Model based on service differentiation according to per hope behavior(PHB) and traffic engineering policy, and two-tire model of above mentioned two models which are adapted differently as the target network status for providing the end-to-end QoS Path are suggested. But, when we integrated this internet QoS into the ATM based network, differences of the connection setup procedure, name/address translation methods, and QoS provisioning mechanisms for end-to-end path setup procedures are introduced. In this paper, we propose the method of shortcut based QoS path setup procedure to solve these problems, and to guarantee the integration and scalability of Next Generation Internet(NGI) names/address in Integrated IP network into ATM based network. This network should support the engineering differentiated into the multiple service classes, which depend on established by this path is designed suitably into the target router and host step by step. In the near future, this function which provide the QoS guaranteed path based on end-to-end shortcut between the configuration devices are extended into the NGI target network.