• Journal of Korean Institute of Industrial Engineers
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• 제19권1호
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• pp.47-59
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• 1993

Recently, Broadband ISDN(B-ISDN) has received increased attention as a communication architecture which can support multimedia applications. Also, Asynchronous Transfer Mode(ATM) is considered as a promising technique to transfer and switch various kinds of media, such as telephone speech, data and motion video. Comparisons among a variety of ATM switching systems which have already been proposed will provide quite useful information for the new ATM switching system design. To facilitate the comparison, we introduce the design requirements and classification criteria for the ATM switch, and propose a performance analysis model for the Banyan network which is the basic switching fabric of most multi-stage ATM switching systems. The model is based on the standard discrete-time Markov chain analysis and can be conveniently used for extensive Banyan network analysis. The computational results are also presented.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제21권1호
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• pp.131-143
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• 1996

In this paper, we propose the improved structure of fully interconnected ATM Switch to develop the small sized switch element and represent practical implementation of switch network. As the part II of the full study about structure and implementation of fully interconnected ATM Switch, this paper especially describes the implementation of an ATM switching element with 8 input port and 8 output port at 155 Mbits/sec each. The single board switching element is used as a basic switching block in a small sized ATm switch for ATM LAN Hub and customer access node. This switch has dedicated bus in 12 bit width(8 bit data + 4 bit control signal) at each input and output port, bit addressing and cell filtering scheme. In this paper, we propose a practical switch architecture with fully interconnected buses to implement a small-sized switch and to provide multicast function withoutany difficulty. The design of switching element has become feasible using advanced CMOS technology and Embedded Gate Array technology. And, we also represent Application Specific Integrated Circuit(ASIC) of Switch Output Multiplexing Unit(SOMU) and 12 layered Printed Circuit Board for interconnection network of switch.

• Journal of the Institute of Electronics Engineers of Korea TC
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• 제37권10호
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• pp.18-25
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• 2000

In this paper, we analyze TCP congestion control algorithm over ATM-UBR network. TCP congestion control algorithm consists of slow start, congestion avoidance, fast recovery, fast retransmit. We analyze the ATM-UBR network service using the BSD 4.3 TCP Reno, Vanilla. However we found the fact that the characteristic of fast retransmit, recovery algorithm makes a serious degradation of Performance in multiple losses of packets. We propose new fast retransmit, recovery algorithm to improve the problem. The results of performance analysis improve the multiple losses of packets using a proposed fast retransmit, recovery algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제22권5호
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• pp.1083-1096
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• 1997

To implement satellite B-ISDN/ATM network, it needs to gurantee reliable transport via satelite in the poor BER environment. So, it requires to use channel coding (FEC:Forward Error Correction) schemes for improvement of BER performance, but these coding effects evoke burst errors and degradation of the QoS. Therefore we have to investigate new algorithm that compensates these weaknesses. We consider convolutional coding and concatenated coding among FEC schemes as FEC for satellite transmission and choose different compensational algorithm by the error characteristics of the using type of FEC. In using concatenated coding, this paper proposes the satellite system structure for interconnection to the terrestrial network and proposes the channel coding algorithm for improvement of transmission performances. We execute performance evaluation of the proposed algorithm by computer simulation. In detail, we propose 4 types of application ATM cell to the block coding(Reed-Solomon) and propose the new 55 byte ATM cell that enforces the error correction capability of cell header by the BCH coding. Then we propose the outer interleaverand the cell unit interleaver that evoke maximum coding effect of BCH code.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제27권6C호
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• pp.562-570
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• 2002

The network-wide performance management is crucial for maintaining the quality of network services, which requires the collection and monitoring the performance data at individual network nodes. Most of the public networks, however, are composed of diverse, heterogeneous network nodes that are managed by various types of proprietary management systems with a conventional operator console and embedded management functions, which makes it difficult to implement the integrated performance management systems. Even though the developments of TMN (Telecommunication Management Network) based management systems are being attempted, the little work has been done in performance management area. In this paper, we propose the performance monitoring architecture for ATM switches using the 0₃ object model and describe how to implement the TMN-based performance prosy agent for ATM switching systems. The proposed performance proxy agent provides the TMN standard performance management interfaces by translating the proprietary performance management functions, which eventually leads to network-wide integrated performance management.

• The Transactions of the Korea Information Processing Society
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• 제4권8호
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• pp.2070-2079
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• 1997

In this paper, we proposed the FNCAC (fuzzy neural call admission control) scheme of the ATM networks which used the benefits of fuzzy logic controller and the learning abilities of the neural network to solve the call admission control problems. The new call in ATM networks is connected if QoS(quality of service) of the current calls is not affected due to the connection of a new call. The neural network CAC(call admission control) system is predictable system because the neural network is able to learn by the input/output pattern. We applied the fuzzy inference on the learning rate and momentum constant for improving the learning speed of the fuzzy neural network. The excellence of the proposed algorithm was verified using measurement of learning numbers in the traditional neural network method and fuzzy neural network method by simulation. We found that the learning speed of the FNCAC based on the fuzzy learning rules is 5 times faster than that of the CAC method based on the traditional neural network theory.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• 제12권6호
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• pp.297-302
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• 2012

RAN in mobile backhaul network connects base station to mobile backhaul network. This the interfaces for several generations mobile communication technologies, such as TDM, ATM, and Ethernet in cell site, and then Ethernet in mobile backhaul site. In near future, the mobile communication network will be changed to all IP/Ethernet one, and then ultimately Ethernet and TDM traffics will be transferred through IP network. So these technologies have to be encapsulated for transferring to the mobile backhaul network. The performances are measured for each encapsulation, such as ATM, MPLS, IP/UDP, and MEF8.

• Journal of the Korean Institute of Telematics and Electronics S
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• 제34S권2호
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• pp.11-20
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• 1997

It is a recent trend that mobile communications and PCS are intergrated into the broadband network. Broadband mutlimedia traffic will be transported over the integrated network. In this paper, we propose a connection re-routing method for fast inter-switch hadoffs and dynamic resurce reservation scheme, which is based on the proposed re-routing method, for the ATM-based personal communications network. To reduce the delay for re-routing method, for the ATM-based personal communications network. To reduce the delay for re-routing, the proposed re-routing method is to reserve VPI/VCIs for possible inter-swich handoff calls in advance. Our reservation scheme is to statistically reserve the fixed resources for possible inter-switch handoff calls, according to the QoS of the handoff calls. The simmulation reslts show that our proposed scheme satisfies the required QoS of handoff calls and keep the dropping probability of handoff calls lower than other schemes.

• Journal of Institute of Control, Robotics and Systems
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• 제6권8호
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• pp.629-637
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• 2000

Unbalance between user requirements and insufficient network resources makes a congestion. In the future since the communication networks will have very heavy traffic congestion will be more serious. The ATM networks was recommended to support the B-ISDN service for the future multimedia communication. In thie sense of congestion avoidance and recovery the ABR service category in ATM networks allows the feedback flow control mechanism to dynamically allocate the idle bandwidth of the network to users fairly and to control the network congestion rapidly In this paper we introduce a congestion control scheme using systematical approach to confirm robust stability with respect to unknown round trip delay for the network which has both unicast and multicast connections.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국해양정보통신학회 2000년도 추계종합학술대회
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• pp.288-291
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• 2000

In ATM Network, many algorithms have been proposed for rate-based ABR new control. The object of these Algorithms is to him around from cell loss and to use the unused bandwidth by ABR Traffic. These Algorithms are applied to control ABR Traffic by EFCI and ER switches. In previous paper, we showed the using rate of bandwidth for the characteristic of each algorithm applied these algorithm network In this paper, we will do that to apply these algorithms to a network and to make a graph of characteristic of each algorithm.