• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
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• pp.83-86
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• 2002

In this paper while a router is routing all packet to the next hop, it inspects whether there is congestion on this current hop router or not and if the router discovers that it has some congestion, it informs that the packet is experienced to congestion. The packet arrived to next hop including some information about the congestion is processed first and it has wider bandwidth than another packet The amount of congestion is recorded to the DS field of IP header by congestion experience level. In the next hop when the packet including the congestion information is routed, the standard packet dropping ratio of the current router is changed in proportion to congestion experience that is recorded in IP header on of that. When the packet that has experienced congestion before is arrived, the router extends the drop threshold value not to drop the packet. It mean that transferring the audio or video stream, if the packet is already experienced the congestion in another hop, the router can provide the better service quality about 15∼25% than another.

• Journal of Electrical Engineering and Technology
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• 제7권2호
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• pp.141-150
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• 2012

The present study examines an efficient congestion management system compatible with the evolving environment. The key is to build an information model shared and exchanged for marketbased solutions to alleviate congestion. Traditional methods for congestion management can be classified into two categories, i.e., the centralized scheme and the decentralized scheme, depending on the extent to which the independent system operator (ISO) is involved in market participants' (MPs) activities. Although the centralized scheme is more appropriate for providing reliable system operation and relieving congestion in near real-time, the decentralized scheme is preferred for supporting efficient market operation. The minimum set of information between the ISO and MPs for decentralized scheme is identified: i) congestion-based zone, ii) Power Transfer Distribution Factors, and iii) transmission congestion cost. The mathematical modeling of the proposed information is expressed, considering its process of making effective use of information. Numerical analysis is conducted to demonstrate both cost minimization from the MP perspective and the reliability enhancement from the ISO perspective based on the proposed information exchange scheme.

• 정보처리학회논문지C
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• 제9C권4호
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• pp.513-522
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• 2002

기존의 end-to-end 방식에서는 네트워크 내부에서 혼잡(congestion)이 발생했을 경우 각 전송자가 즉시 알아 낼 수 없기 때문에 일정시간 동안 수신된 패킷(packet)의 순서에 대한 정보로 흔잡이 발생했는지에 대해 추론하는 것이다. 이와 같은 방법은 RTT(Round Trip Time)가 커지면 혼잡이 발생할 경우 전송자가 전송 양을 줄인다 해도 이미 전송된 패킷들로 인하여 흔잡이 가중되며 전체적인 TCP 동기화 (TCP Global synchronization) 현상을 피할 수 없게 된다. 반면 네트워크 내부에서 직접적으로 정보를 얻거나 처리를 해 줄 수 있다면 혼잡 발생과 동시에 처리가 가능함으로 기존 방식보다 처리율이 향상될 것이다. 본 논문에서는 액티브 라우터의(Active Network) 피드백 메커니즘을 이용하여 네트워크 내부 정보를 각 전송자가 이용할 수 있도록 하기 위해 라우터와의 통신을 이용하였으며, 코어 라우터의 큐 모듈은 RED(Random Early Detection)를 응용하여 ACC의 누락 메커니즘을 개선하였다. ACC를 확장한 메커니즘인 EACC(Enhanced Active Congestion Control)를 제시하고 모의실험을 통해 기존의 혼잡제어나 ACC(Active Congestion Control)보다 성능이 향상됨을 보여준다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.442-445
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• 2006

무선 센서 네트워크에서 다수의 센서들은 데이터를 브로드캐스트하기 때문에 데이터의 중복성을 가진다. 데이터의 중복성은 네트워크 로드를 가중시키며 데이터 손실의 원인이 된다. 이러한 문제점들은 데이터 전송의 신뢰성과 네트워크 혼잡 회피 간의 상충조건을 발생시킨다. 따라서 무선 센서 네트워크에서 효율적으로 혼잡제어를 수행하기 위해서는 신뢰성 있는 전송(reliable transmission), 무선 손실(wireless loss), 혼잡 손실(congestion loss) 등과 같은 여러 요소를 고려한 신뢰성 있는 혼잡제어 기법이 필요하다. 본 논문에서는 Hop-by-Hop 순서 번호, DSbACK(Delayed and Selective ACK, Buffer Condition)을 사용하여 신뢰성 있는 전송을 보장하고 불필요한 전송을 최소화한 에너지 절약형 혼잡 제어 기법으로 HRCCP(Hop-by-Hop Reliable Congestion Control Protocol)를 제안하여 무선 센서 네트워크에서 신뢰성 있는 전송과 혼잡 제어가 동시에 이루어질 수 있도록 하였다.

• 한국컴퓨터정보학회논문지
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• 제24권2호
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• pp.49-56
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• 2019

In this paper, we propose an efficient congestion control scheme for interworking between 5GS(5G system) and LTE(Long-Term Evolution), called ECC(Efficient Congestion Control). The proposed congestion control scheme (ECC) is considered for coexistence of 5GS and legacy LTE systems and provides a prompt service connectivity based on overriding method while the backoff timer is running in the UE. Also, we briefly introduce Rel-15 5GS from a congestion control perspective and the proposed ECC and simulation results for the existing legacy congestion control mechanism and ECC in the 5GS-LTE coexisting environment are presented. Lastly, the improvement direction is considered in future 3GPP 5GS phase 2 standard in this paper.

• 한국IT서비스학회지
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• 제20권5호
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• pp.29-41
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• 2021

The spread of COVID-19 has been changed the tourism industry. Travelers changed their traveling style and started to consider congestion of the spot for their health and safety. In Jeju, a famous tourist destination in South Korea, managing the congestion of tourists has become an important issue. This example introduces the Jeju Tourism Organization's development of a system as a smart tourism information service that manages congestion in real-time big data. Combining with congestion theory and behavior immune system, we would like to assure the necessity of the system. Also, by analyzing the system, we understand how deducing congestion information from big data and the new paradigm of the tourism industry combined with congestion theory. Data was collected by Korea's telecommunication company SKT to develop the system. The paper explains the reason for choosing the company and the pros of data quality. We expect this system to be a solution for any other city in the world under a similar situation. Finally, several suggestions for the system are included to promote and better future usage.

• 한국멀티미디어학회논문지
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• 제13권12호
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• pp.1798-1804
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• 2010

TCP with AIMD mechanism, one of the most popular protocols in internet, can solve congestion control in wired networks. This protocol, however, is not efficient in wireless networks. This paper proposes a new mechanism namely General AIMD with Congestion Window Upper Bound in which congestion window is limited by an upper bound. By applying optimization theory, we find an optimal policy for congestion window upper bound to maximize network throughput.

• 한국통신학회논문지
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• 제33권11B호
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• pp.961-967
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• 2008

Congestion control is one of major mechanisms to avoid dropped packets. Many researchers use optimization theories to find an efficient way to reduce congestion in networks, but they do not consider robustness that may lead to unstable network utilities. This paper proposes a new methodology in order to solve a congestion control problem for wired networks by using a robust design principle. In our particular numerical example, the proposed method provides robust solutions that guarantee high and stable network utilities.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권8호
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• pp.3809-3822
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• 2017

Wireless Sensor Networks hold the limelight because of significant potential for distributed sensing of large geographical areas. The radio duty cycling mechanism that turns off the radio periodically is necessary for the energy conservation, but it deteriorates the network congestion when the traffic load is high, which increases the packet loss and the delay too. Although many papers for WSNs have tried to mitigate network congestion, none of them has mentioned the congestion problem caused by the radio duty cycling of MAC protocols. In this paper, we present a simple and efficient congestion control technique that operates on the radio duty cycling MAC protocol. It detects the congestion by checking the current queue size. If it detects the congestion, it extends the network capacity by adding supplementary wakeup times. Simulation results show that our proposed scheme highly reduces the packet loss and the delay.

• 정보과학회 컴퓨팅의 실제 논문지
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• 제21권1호
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• pp.19-28
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• 2015

본 논문에서는 과거 교통정체 패턴을 이용하여 현재의 교통정체가 풀리는 정체인지 아니면 악화되는 정체인지를 판별하는 알고리즘을 제안한다. 과거 교통정체 패턴은 다중 포인터를 이용하여 정체구간들을 연결한 인접 리스트에 교통정체의 시간적 길이와 공간적 길이로 저장된다. 교통정체가 시작된 구간에 해당하는 헤드노드를 탐색하고 현재패턴과 가장 유사한 과거 교통정체 패턴을 이용하여 장래의 교통정체 변화정보를 제공한다. 실험을 통해 검증한 결과, 도로 구간 하나에 대한 정체 변화를 판별하였을 때 실제 값과 비교해서 평균적으로 15분 오차를 보였으며, 연속된 다수의 도로 구간들을 결합하여 비교적 긴 구간의 정체 변화를 판별하였을 경우 평균적으로 10분 이내의 오차를 보이며 실제 값과 유사한 것을 보였다.