• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.8
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• pp.1391-1400
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• 2008

In recent yeats, SCTP is known as the next transport layer protocol for connection-oriented and reliable data transfer after TCP/UDP. The SCTP was developed on the basis of the existing TCP and was designed to eliminate defects of TCP. SCTP has the different characteristic of multi-streaming and multi-homing from TCP. In this paper, we studied the defects of the performance of communication using the traits of multi-homing. And we evaluated the efficiency for each application services on the basis of SCTP of IPv6. Also, we analysed the delay time of a packet using SCTP and TCP. We noticed that the efficiency of SCTP is better than that of TCP.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11b
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• pp.1249-1252
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• 2002

클러스터와 같은 네트워크 컴퓨팅 환경에서는 신속하고 신뢰성이 보장되는 데이터 전송이 요구된다. 신뢰성 보장을 위해서 일반적으로 사용되는 전송 프로토콜은 TCP 이다. 그러나 클러스터의 하부 네트워크로서 많이 사용되는 Myrinet 은 cut-through 스위칭 방식을 기반으로 하기 때문에 네트워크 혼잡(congestion)이 발생하지 않는다. 따라서 TCP 의 혼잡 제어(congestion control) 등과 같은 루틴들은 Myrinet 상에서 불필요한 오버헤드를 발생시킨다. 본 논문은 Myrinet 네트워크에서 흐름 제어(flow control)만으로도 신뢰성을 보장할 수 있음을 보이고 TCP 보다 오버헤드가 적은 UDP에 흐름 제어를 구현한 RUM(Reliable UDP on Myrinet)을 제안한다. 성능 측정 결과, RUM 은 신뢰성을 보장함과 동시에 TCP 보다 최대 34% 더 높은 처리량(throughput)을 보이며, UDP 와 비슷한 낮은 단방향 지연시간(one-way latency)을 보장함을 알 수 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.9A
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• pp.878-883
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• 2006

New emerging wireless broadband internet can make many broadband multimedia services. The networked intelligent mobile robot service is one of the new services. In the networked robot control, both the on-line real-time control and the reliability of control data transmission are very important. Considering the real-time control and data reliability, an efficient transmission method based on UDP protocol is proposed. The proposed method allocates the priority to the robot control data and the transmission of the robot data at the base station is carried out in duplicate manner. NS-2 simulation results show that the proposed scheme has a very low packet delay and low packet errors.

• Journal of Broadcast Engineering
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• v.24 no.4
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• pp.602-612
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• 2019

Various streaming technologies are being studied to guarantee the QoE of viewers due to the development of realistic media. HTTP adaptive streaming is a typical example, and it is based on HTTP / 1.1 and TCP. These protocols have become one of the causes of delaying the image delay and increasing the waiting time of web pages. Therefore, in this paper, we propose a QUIC-DASH system applying the UDP-based transmission protocols QUIC and HTTP / 2 to the MPEG-DASH system after analyzing various transmission protocols and development process of HTTP. Through experiments, the QUIC-DASH system confirmed the possibility of providing optimal performance in terms of transmission speed of LTE environment than existing system. We also suggest various future studies for better performance.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.2
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• pp.30-36
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• 2007

The UPnP uses the same standard protocol as SSDP and UDP based on standard internet and technology like the TCP/IP, and is independent of other physical networking product. But the structure of the UPnP has the of vulnerability to the security countermeasure for home-networking technology since it is operated on the same protocol as the SSDP and UDP. In this paper, we analyze and report against the DoS attack, where the worm virus, using the vulnerability to the UPnP, eliminates the attack of all equipments that are based on networking and eliminates the information belonging to the equipments of the home-networking or transmits the massive data.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.2
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• pp.23-31
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• 2012

With advance of high bandwidth network infrastructure, the requirement is dramatically increasing to cooperate between the users who are far from each other and make use of bulk data. However, as the prominent data transmission protocol, it is well known that TCP suffers some degrees of inefficiency for bulk data transmission when RTT is relatively big. So, some works are on going to suggest a new transmission method to utilize the bandwidth in effective. UDT(UDP-based Data Transfer protocol) is one of these. It is a UDP based application level protocol which can guarantee reliability and stability. much like as TCP. In this paper, we present a design and implementation of UDT based bulk data transmission tool by applying parallel and compressive techniques. The implementation result is examined to measured its performance improvement on a real test-bed, and then compared with existing bulk data transmission tools. Experimental results show that proposed tool is more stable and shows greater performance than that of native UDT. Especially, the performances show 244% improvement in RTT 400ms without losses and 229% in RTT 250ms with 0.005% losses respectively.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2018.11a
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• pp.18-21
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• 2018

최근 시청자에게 실재적인 몰입감을 제공하는 실감미디어가 발전하고 있다. 이러한 실감미디어 중 가장 접근성이 뛰어난 것은 VR으로, 현재 다양한 서비스에 응용되고 있는 상황이다. 하지만 360VR은 높은 비트 전송률과 고해상도의 특성을 지니고 있기 때문에 대역폭 비용 및 시청자의 QoE 보장의 불확실성 등의 다양한 문제가 있다. 이러한 문제를 개선시키기 위해 HTTP 기반의 적응적 스트리밍 기법이 발전해나가고 있으며 이 기술의 표준으로 MPEG-DASH가 채택되었다. MPEG-DASH는 TCP 기반의 전송 프로토콜을 사용하고 있지만 현재 TCP는 고용량의 데이터가 전송되는 웹 기반에서 HTTP의 병목현상을 일으켜 대역폭 효율성을 떨어뜨리는 하나의 원인으로 나타나고 있다. 이러한 문제를 해결하기 위해 본 논문에서는 UDP 기반의 QUIC 프로토콜을 MPEG-DASH에 적용하는 시스템을 고안하고 이를 QUIC-DASH라 칭한다. 고해상도의 360VR 송출 실험으로 QUIC-DASH 시스템과 기존의 MPEG-DASH 시스템을 비교 분석한 결과로 대역폭의 절감이 이루어진 것을 확인하였다.

• Journal of the Korea Society of Computer and Information
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• v.16 no.2
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• pp.131-140
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• 2011

Smart packet agent is an application that is proposed to provide routing protocol and service module in ubiquitous network environment. However, it uses multi-hop broadcast, thus it causes increasing network traffic, low-speed data transmission, and the unnecessary joining nodes. In this paper, a transmit technique that uses unicast-based multi-hop to have lower network traffic and faster transmission time than the multi-hop broadcast technique. In our scheme, u-Zone Master establishes temporary routing paths by calculating moving nodes' hop-counter. Therefore, it reduces smart packet agent's network traffic and retransmission rate. Besides, this paper proposed an UDP transmission that bases on sliding window. Hence, the Stop & Wait transmission speed is improved. The results, which are taken by analyzing performance prove that the proposed scheme has better performance.

• Smart Media Journal
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• v.2 no.4
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• pp.51-59
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• 2013

With increasing transmission speed of backbone networks, it is getting to provide enough available bandwidth. However, the bandwidth is not effectively utilized in volumetric data transfer. This mainly comes from the transmission protocol, TCP, which is used for most applications. TCP is inherently difficult to adapt the available bandwidth because of it's own characteristic of transfer mechanism. UDT is a prominent application level data transfer protocol which is targeting high speed network. In this paper, we propose UDT parallel transfer technologies which is adaptive to network status and then evaluate their performance in two points of view. Firstly, we measure data transfer rate of UDT with rate congestion control methods, and compare them with basic UDT. Secondly, we apply parallel transfer technologies adapted to network status, and measure their performance. Experimental results showed that UDT rate congestion control method outperforms UDT with 106% improvement in RTT 100ms section set with jitter 30ms. In addition, performance of parallel transfer with rate congestion control method showed 107% improvement than that of parallel transfer in RTT 400ms section set with jitter 20ms.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11b
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• pp.1357-1360
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• 2002

무선 데이터 통신이 하루가 다르게 증가하면서 무선망에서 핸드폰을 이용해 멀티미디어 데이터를 스트리밍하는 기술들이 연구되며 소개되어지고 있다. 이러한 기술을 연구하는데 있어서는 첫째로 데이터 전송 실험을 통한 무선 망에 대한 이해 및 특성 파악이 필요하고, 둘째로 이런 망 특성에 따른 적합한 스트리밍 기법 연구가 필요하다. 본 논문에서는 이러한 방법에 따라 망의 특성 파악에 관한 데이터를 기반으로 실험을 통해 EVRC 오디오 코텍을 이용한 핸드폰에서의 오디오 스트리밍에 있어 좀 더 나은 에러 대처 방법과 트랜스포트 프로토콜의 사용 기법을 제안하고 있다.