• Title, Summary, Keyword: Congestion Management

Search Result 430, Processing Time 0.039 seconds

A Study on Settlements in Internet Interconnection under Internet Congestion (네트워크 혼잡효과를 고려한 인터넷망간 상호정산 방안 연구)

  • Jung, Choong-Young
    • Journal of Information Technology Applications and Management
    • /
    • v.14 no.2
    • /
    • pp.97-115
    • /
    • 2007
  • The present paper investigates the technological and conceptional characteristics of peering and transit in internet interconnection. Especially, the market with two ISP competing for customers is modeled and the outcome with peering is compared with transit. This paper also analyze the congestion effects on retail price and network capacity. When there is congestion effects occurring from network sharing, the retail price is increased and the fixed fee is decreased with the degree of congestion. Finally, the optimal access charge assuring the socially optimal retail price and network capacity is derived.

  • PDF

Preliminary Design of a Urban Transit Passenger Guidance System Using Congestion Management Model (혼잡관리 모형을 이용한 도시철도 이용객 동선유도시스템 기본설계)

  • Kim, Kwang-Mo;Park, Hee-Won;Kim, Jin-Ho;Park, Yong-Gul
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.16 no.5
    • /
    • pp.3610-3618
    • /
    • 2015
  • The congestion of railway vehicle and station shows up to 220%. Especially, transfer resistance of passenger increase rapidly by the collision of circulation. So increment of travel time, occurrence of safety accidents act as a factor that inhibits the utilization of urban railway station. In this paper, to improve traveling speed and comfort of urban rail passengers, urban transit passenger guidance system using congestion management model is proposed. The congestion management model that can mitigate a recurring/non-recurring congestion is constructed and the preliminary design of the system (middleware system, control system, guidance drive system) is carried out. Passenger Guidance System is configured by step for changing the external data into a form usable by the algorithm, step to perform the congestion management algorithm using the real-time data and historical data, step to control device based on the value that is calculated by congestion management algorithm, step to drive the device based on the information in the control system and circulation guidance devices. In the future, detail design will be performed based on the preliminary design. A prototype of the various devices according to the station structures and locations will be made. The control module of guidance device will be developed.

An Automatic Pattern Recognition Algorithm for Identifying the Spatio-temporal Congestion Evolution Patterns in Freeway Historic Data (고속도로 이력데이터에 포함된 정체 시공간 전개 패턴 자동인식 알고리즘 개발)

  • Park, Eun Mi;Oh, Hyun Sun
    • Journal of Korean Society of Transportation
    • /
    • v.32 no.5
    • /
    • pp.522-530
    • /
    • 2014
  • Spatio-temporal congestion evolution pattern can be reproduced using the VDS(Vehicle Detection System) historic speed dataset in the TMC(Traffic Management Center)s. Such dataset provides a pool of spatio-temporally experienced traffic conditions. Traffic flow pattern is known as spatio-temporally recurred, and even non-recurrent congestion caused by incidents has patterns according to the incident conditions. These imply that the information should be useful for traffic prediction and traffic management. Traffic flow predictions are generally performed using black-box approaches such as neural network, genetic algorithm, and etc. Black-box approaches are not designed to provide an explanation of their modeling and reasoning process and not to estimate the benefits and the risks of the implementation of such a solution. TMCs are reluctant to employ the black-box approaches even though there are numerous valuable articles. This research proposes a more readily understandable and intuitively appealing data-driven approach and developes an algorithm for identifying congestion patterns for recurrent and non-recurrent congestion management and information provision.

Development of Expressway TRaffic Analysis Model(ExTRAM) (고속도로 교통분석 프로그램(ExTRAM) 개발)

  • Lee, Seung-Jun;Choi, Yoon-Hyuk;Bae, Young-Seok;Kim, Nak-Joo
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.9 no.6
    • /
    • pp.63-82
    • /
    • 2010
  • In spite of continuous road construction, traffic congestion has been worsening by radical vehicle's increase and development of surroundings near expressway. Thus, the necessity of traffic management and the needs of provision of traffic information to drivers are raised. In order to solve traffic problems, such as traffic congestion, search for optimal congestion management technique and evaluation of the effect of optimal solution should be examined prior to practice of optimal alternative. However, existing traffic analysis model and simulation programs as tools to search and evaluate optimal alternative are not sufficient to reflect traffic flow characteristics, domestic road and traffic conditions and to link up to Freeway Traffic Management Systems (FTMS). Hence, to use existing traffic analysis and simulation tools are followed by hard work to need a lot of time and cost. Therefore, in this research, Expressway TRaffic Analysis Model (ExTRAM) based on Freeway Traffic Management Systems (FTMS) was developed to apply it into congestion management easily.

Technical Trend and Improvement of Congestion Control for Machine-to-Machine Communications in 3GPP LTE-A Systems (3GPP LTE-A 시스템에서의 M2M 통신을 위한 혼잡 제어 기술 동향 및 개선 방안)

  • Kim, Jae-Hyun;Kim, Seog-Gyu
    • KIPS Transactions on Software and Data Engineering
    • /
    • v.3 no.11
    • /
    • pp.487-494
    • /
    • 2014
  • This paper focuses on an advanced congestion control scheme for M2M(Machine-to-Machine) communications in 3GPP LTE-A standard. A large number of MTC(Machine-type-Communication) devices try to access to LTE-A networks and send data to the networks all at once. In this characteristics, M2M communications will bring the serious network congestion problems into LTE-A cellular networks. To solve this critical problem, a congestion control mechanism will be required and it has been studied since Rel-10 LTE-A systems based on backoff mechanism for mobility management and session management. In this paper, we briefly introduce the main concept and operation about the congestion control scheme in 3GPP LTE-A standard. Also, simulation results for the basic congestion control and advanced congestion control scheme in MTC communication environment are provided and the improvement direction is considered in future 3GPP LTE-A standard.

Reducing Congestion General Queuing Networks (일반 대기 네트워크에 있어서 시스템 설계애 관한 연구)

  • Kim, Sung-Chul
    • Journal of the Korean Operations Research and Management Science Society
    • /
    • v.14 no.2
    • /
    • pp.87-96
    • /
    • 1989
  • We develop an algorithm to determine the optimal loading policy, which minimizes the congestion in general queueing networks with variable stations. Under more specified condition, majorization and arrangement ordering are established to compare, respectivity, various loading and assignment policies. Implications of results are also discussed.

  • PDF

Benefits of Using Imperfect Information in Controlling an M/M/1 Queueing System

  • Nam, Ick-Hyun
    • Management Science and Financial Engineering
    • /
    • v.1 no.1
    • /
    • pp.1-19
    • /
    • 1995
  • In this paper, we analyze an M / M / 1 queueing system where there are incentive conflicts among customers. Self-interested customers' decisions whether to join the system or not may not necessarily induce a socially optimal congestion level. As a way to alleviate the over-congestion, toll imposition was used in Naor's paper [3]. Instead of using a toll mechanism, we study the usefulness of imperfect information on system state (queue size, for example) as a way to reduce the over-congestion by self-interested customers. The main conclusion of this paper is that by purposefully giving fuzzy or imperfect information on the current queue size we can improve the congestion in the system. This result might look contradictory to rough intuition since perfect information should give better performance than imperfect information. We show how this idea is verified. In deriving this result, we use the concept of Nash equilibrium (pure and mixed strategy) as introduced in game theory. In some real situations, using imperfect information is easier to apply than imposing a toll, and thus the result of this paper has practical implications.

  • PDF

Nonlinear Congestion Controller for Active Queue Management of Differentiated Services Networks (차등화 서비스 네트워크의 능동 큐 관리 기법을 위한 비선형 혼잡 제어기)

  • Park, Ki-Kwang;Jang, Jin-Su;Ko, Jin-Hyeok;Yang, Hai-Won
    • Proceedings of the KIEE Conference
    • /
    • /
    • pp.1668-1669
    • /
    • 2007
  • In this paper, we propose nonlinear congestion controller for active queue management of differentiated-services networks. Two important issues in differentiated-services architecture are bandwidth guarantee and fair sharing of unsubscribed bandwidth among TCP flows with and without bandwidth reservation. The nonlinear congestion controller was composed fuzzy logic controller and state feedback controller. The nonlinear congestion controller methodology has been applied to a TCP network. We use NS-2 simulation to demonstrate that the proposed control methodology achieves the desired behavior of the network, and possesses important attributes.

  • PDF

NetDraino: Saving Network Resources via Selective Packet Drops

  • Lee, Jin-Kuk;Shin, Kang-G.
    • Journal of Computing Science and Engineering
    • /
    • v.1 no.1
    • /
    • pp.31-55
    • /
    • 2007
  • Contemporary end-servers and network-routers rely on traffic shaping to deal with server overload and network congestion. Although such traffic shaping provides a means to mitigate the effects of server overload and network congestion, the lack of cooperation between end-servers and network-routers results in waste of network resources. To remedy this problem, we design, implement, and evaluate NetDraino, a novel mechanism that extends the existing queue-management schemes at routers to exploit the link congestion information at downstream end-servers. Specifically, NetDraino distributes the servers' traffic-shaping rules to the congested routers. The routers can then selectively discard those packets-as early as possible-that overloaded downstream servers will eventually drop, thus saving network resources for forwarding in-transit packets destined for non-overloaded servers. The functionality necessary for servers to distribute these filtering rules to routers is implemented within the Linux iptables and iproute2 architectures. Both of our simulation and experimentation results show that NetDraino significantly improves the overall network throughput with minimal overhead.

The Evaluation of Existing Congestion Indices' Applicability for Development of Traffic Condition Index (소통관리 지표 개발을 위한 기존 혼잡지표의 국내 적용성평가 연구)

  • Lee, Seung-Jun;Kim, Tae-Young;Ko, Han-Geom;Bok, Ki-Chan
    • International Journal of Highway Engineering
    • /
    • v.10 no.3
    • /
    • pp.119-128
    • /
    • 2008
  • On the many highways, severe traffic congestions happen chronically and make traffic problems like reduction of mobility because of rapid increase of vehicles though road construction has been last. In order to solve these traffic problems, it is needed to find the trend and the symptom of traffic congestion and to analyze the cause of congestion and the(spatial) range affected by congestion. To develop the traffic condition monitoring index prior to doing all those things is most important. With this reason, many countries including U.S. had been developed the congestion criteria and indices. In this paper, applicability and characteristics of existing traffic congestion indices were considered and the direction for development of a new traffic condition index was suggested to achieve an effective traffic management.

  • PDF