• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제16권4호
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• pp.452-456
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• 2010

무선 센서 네트워크에서는 다수의 노드에서 소수의 싱크로 수렴하는 트래픽의 특성으로 인해 네트워크의 혼잡이 빈번히 발생한다. 기존의 혼잡 제어 기법은 혼잡 발생 시 트래픽 제어를 통해 혼잡을 회피할 수 있으나 트래픽의 제어는 응용에서 요구하는 피델리티를 위반한다는 단점을 갖는다. 본 논문에서는 리소스의 제어를 통하여 혼잡을 회피하는 멀티패스 기반의 혼잡 제어 기법을 제안한다. 멀티패스 기반 혼잡제어 기법은 혼잡 발생 시 다수의 대체 경로를 통하여 트래픽을 분산시켜 전송하므로 혼잡 회피가 가능하고 네트워크 리소스의 활용도 또한 증대한다. 실험을 통해 멀티패스 기반 혼잡 제어 기법이 응용의 피델리티를 만족시키며 효과적으로 혼잡을 제어할 수 있음을 확인하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권1호
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• pp.414-435
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• 2017

As network adaptive streaming technology becomes increasingly common, transport protocol also becomes important in guaranteeing the quality of multimedia streaming. At the same time, because of the appearance of high-quality video such as Ultra High Definition (UHD), preventing buffering as well as preserving high quality while deploying a streaming service becomes important. The Internet Engineering Task Force recently published Multipath TCP (MPTCP). MPTCP improves the maximum transmission rate by simultaneously transmitting data over different paths with multiple TCP subflows. However, MPTCP cannot preserve high quality, because the MPTCP subflows slowly increase the transmission rate, and upon detecting a packet loss, drastically halve the transmission rate. In this paper, we propose a new multipath congestion control scheme for high-quality multimedia streaming. The proposed scheme preserves high quality of video by adaptively adjusting the increasing parameter of subflows according to the network status. The proposed scheme also increases network efficiency by providing load balancing and stability, and by supporting fairness with single-flow congestion control schemes.

• 한국정보통신학회논문지
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• 제21권6호
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• pp.1127-1136
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• 2017

무선 네트워크에서 TCP는 비트 에러에 인한 패킷 손실을 혼잡상태에 의한 손실로 오인하여 잦은 혼잡제어가 일어나 성능 저하가 발생한다. 이러한 성능 저하는 기존 TCP를 확장한 프로토콜인 MPTCP (Multipath TCP) 에서도 발생하며, MPTCP의 경우 다중 경로의 전체 성능이 저하되는 문제점도 발생한다. 따라서 본 논문에서는 무선 환경에서 MPTCP 성능 저하를 해결하기 위해 MPTCP 각 경로상의 대역폭을 측정하고 패킷 손실이 발생할 때 측정된 대역폭 만큼 혼잡 윈도우 크기를 줄이는 혼잡제어를 제안하였다. 그리고 제안한 혼잡제어를 리눅스커널에 구현 설치하고 무선 환경의 특성을 적용한 테스트베드와 실제 무선 네트워크에서 기존 MPTCP와 비교분석하였다. 실험결과 제안한 혼잡제어가 기존 MPTCP 혼잡제어보다 무선 환경에서 좋은 처리량 성능을 보여주었다.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2012년도 한국컴퓨터종합학술대회논문집 Vol.39 No.1(D)
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• pp.401-403
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• 2012

In this paper, we introduce a multipath congestion control algorithm for audio/video streaming, called MPSQRT. MPSQRT is derived from single-path Square-Root TCP (SQRT TCP) designed for multimedia streaming, where a lower variation of sending rate is important. Based on the fluid model of SQRT for single-path, we extend it towards spreading concurrently packets across multiple paths ensuring load-balancing and fairness to SQRT at shared bottleneck. Through simulations, we evaluate the proposed protocol under various network conditions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권3호
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• pp.1406-1424
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• 2017

Recent advancements in network infrastructures provide increased opportunities to support data delivery over multiple paths. Compared with multi-homing scenario, overlay network is regarded as an effective way to construct multiple paths between end devices without any change on the underlying network. Exploiting multipath characteristics has been explored for TCP with multi-homing device, but the corresponding exploration with overlay network has not been studied in detail yet. Motivated by improving quality of experience (QoE) for reliable data delivery, we propose a multipath message transport protocol based on application level relay (MPMTP-AR). MPMTP-AR proposes mechanisms and algorithms to support basic operations of multipath transmission. Dynamic feedback provides a foundation to distribute reasonable load to each path. Common source decrease (CSD) takes the load weight of the path with congestion into consideration to adjust congestion window. MPMTP-AR uses two-level sending buffer to ensure independence between paths and utilizes two-level receiving buffer to improve queuing performance. Finally, the MPMTP-AR is implemented on the Linux platform and evaluated by comprehensive experiments.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2009년도 추계학술발표대회
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• pp.465-466
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• 2009

This paper investigates congestion detection and control strategies for multi-path traffic (CDCM) diss emination in lifetime-constrained wireless sensor networks. CDCM jointly exploits packet arrival rate, succ essful packet delivery rate and current buffer status of a node to measure the congestion level. Our objec tive is to develop adaptive traffic rate update policies that can increase the reliability and the network lif etime. Our simulation results show that the proposed CDCM scheme provides with good performance.

• 한국멀티미디어학회논문지
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• 제19권8호
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• pp.1404-1414
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• 2016

Cross-layer design is a concept, which captures the dependencies and interactions and enables information sharing among layers in order to improve the network performance and security. There are two key challenges in wireless networks, lossy features of links and power assumption of network nodes. Cross-layer design of congestion control and power allocation in wireless lossy networks has been studied in the existing literature; however, there has been no contribution proposed in the literature that exploits the path diversity. In this paper, we are motivated to develop a cross-layer design of congestion control and power allocation, which takes into account lossy features of wireless links and transmission powers of network nodes and can be implemented in a distributed manner. Numerical simulation is conducted to illustrate the performance of our proposed algorithm and the comparison with current alternative approaches.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2008년도 한국컴퓨터종합학술대회논문집 Vol.35 No.1 (A)
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• pp.267-268
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• 2008

• Journal of Communications and Networks
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• 제5권3호
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• pp.230-239
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• 2003

In this paper, we propose a framework to study how to route packets efficiently in multipath communication networks. Two traffic congestion control techniques, namely, flow assignment and packet scheduling, have been investigated. The flow assignment mechanism defines an optimal splitting of data traffic on multiple disjoint paths. The resequencing delay and the usage of the resequencing buffer can be reduced significantly by properly scheduling the sending order of all packets, say, according to their expected arrival times at the destination. To illustrate our model, and without loss of generality, Gaussian distributed end-to-end path delays are used. Our analytical results show that the techniques are very effective in reducing the average end-to-end path delay, the average packet resequencing delay, and the average resequencing buffer occupancy for various path configurations. These promising results can form a basis for designing future adaptive multipath protocols.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권7호
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• pp.2354-2370
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• 2015

The advantages of employing SCTP-based Concurrent Multipath Transfer (CMT) have been demonstrated to be very useful for data delivery over multi-homed wireless networks. However, there is still significant ongoing work addressing some remaining limitations and challenges. The most important concern when applying CMT to data delivery is related to handling packet reordering and buffer blocking. Another concern on this topic is that current sender-based CMT solutions seldom consider balancing the overhead and sharing the load between the sender and receiver. This paper proposes a novel Receiver-driven Cooperation-based Concurrent Multipath Transfer solution (CMT-Rev) with the following aims: (i) to balance overhead and share load between the sender and receiver, by moving some functions including congestion and flow control from the sender onto receiver; (ii) to mitigate the data reordering and buffer blocking problems, by using an adaptive receiver-cooperative path aggregation model, (iii) to adaptively transmit packets over multiple paths according to their receiver-inspired sending rate values, by employing a new receiver-aware data distribution scheduler. Simulation results show that CMT-Rev outperforms the existing CMT solutions in terms of data delivery performance.