• Journal of KIISE:Information Networking
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• v.27 no.2
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• pp.237-246
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• 2000

A broadband access network in B-ISDN subscriber network, plays a role of concentration or multiplexing of various subscribers into a service node. For call and connection control functions, DSS2 and B-ISUP signalling protocols are standardized for each of a subscriber side and a network node. B-BCC and B-ANCC protocol were proposed for VB5.2 interface. This interface allows dynamic control of ATM connections at the broadband access network. To establish an end-to-end ATM connection, interworking functions between VB5.2 interface's connection control protocol and the signalling protocol, are performed at the service node. A sequential interworking model and a parallel interworking model were proposed for these interworking functions. The sequential interworking model recommended by ITU-T causes an overall connection setup delay by introducing the access network, because this model proceeds the signalling protocol of network node after the response of VB5.2 interface protocol. On the other hand, the parallel interworking model proceeds the signalling protocol and the VB5.2 interface protocol simultaneously. The simultaneity of the parallel interworking model minimizes the overall connection setup delay. In this paper, we analyze and simulate above two interworking models with B-BCC or B-ANCC protocol in terms of a connection setup delay and completion ratio.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.6
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• pp.380-387
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• 2004

In accordance with the computerization of railway signaling systems, the interface link between the signaling systems has been replaced by a digital communication channel. At the same time, the importance of the communication link has become increasingly significant. However, there are some questionable matters in the current state of railway signaling systems in KNR. First, different communication protocols have been applied to create an interface between railway signaling systems although the protocols have the same functions. Next, the communication protocols currently used in the railway fields have some illogical parts such as structure, byte formation, error correction scheme, and so on. To solve these matters, the standard communication protocol for railway signaling systems is designed. The newly designed protocol is overviews in this paper. And the simulation is performed to analysis the performance of data link control for designed protocol. According to this simulation, it is identified that the link throughput of new protocol is improved about 10% and the frame error rate is improved than existing protocol. And it is verified the safety and liveness properties of designed protocol by using a formal method for specifying the designed protocol. It is expected that there will be an increase in safety, reliability and efficiency in terms of the maintenance of the signaling systems by using the designed communication protocol for railway signaling.

• Journal of Advanced Navigation Technology
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• v.12 no.5
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• pp.464-469
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• 2008

The RS-232C (Unbalanced serial) and RS-485 (balanced serial) are standard in serial communication. RS-485 uses a differential electrical signal, as opposed to unbalanced signals referenced to ground with the RS-232. Differential transmission, which uses two lines each for transmit and receive signal results in greater noise immunity and longer distances as compared to the RS-232C. The greater noise immunity and distance are big advantages in industrial environments. In general, one protocol on one serial interface is very normal application. In this study, we implemented multi protocols on one serial RS-485 interface and examine the performance and result with hanging multi equipments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.7
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• pp.1346-1363
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• 1994

Packet voice protocols have been realized in many research works. But few studies for the interconnection of LAN and PABX to facilitate the voice communication have been done. In this paper, the gateway to interconnect the Ethernet LAN with the existing PABX telephone network for voice communication has been designed and implemented. The implemented gateway protocol is a modified protocol based on CCITT`s G.764 packetized voice protocol. To accomplish this goal the hardware system has been realized, which is divided into five parts: interface part with the telephone line, voice-processing part, PC interface part, controller part, and finally DTMF part. And the gateway software is divided into three parts: interface to make use of the packet driver which drives the network card, driver to drive the PABX gateway, and the protocol handling part.

• The Transactions of the Korea Information Processing Society
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• v.7 no.9
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• pp.2948-2957
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• 2000

A broadband access network in B- ISDN subscriber network, plays a role of concentration or multiplexing of various subscribers into a service node. To establish an end-to-end ATM connection, interworking functions between \'B5.2 interface's connection protocol and the signalling protocol, are perfonned at the service node. A sequential interworking model and a parallel interworking model were proposed for these interworking functions. The sequential interworking model proceeds the signalling protocol of network node after the response of VB5.2 interface protocol. On the other hand, the parallel interworking model proceeds the signalling protocol and the VB5.2 interface protocol simultaneously. In this paper, we analyze and simulate above two interworking models in tenns of a connection setup delay and completion ratio, when call requests with eBR and VBR transfer capability arrive at the service node. We observed that the completion ratios of the two interworking models are quite closed. However the connection setup delay of parallel interworking model is improved by about 33% compared with that of the sequential interworking model.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.354-357
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• 2004

According to the computerization of railway signaling systems, the interface link between the signaling systems has been replaced by the digital communication channel. At the same time, the importance of the communication link is more pronounced than in the past. In this paper, new network-based protocol for Korean railway signaling has designed between CTC and SCADA system, and the overview of designed protocol is briefly represented. Using the informal method for specifying the communication protocol, a little ambiguity may be contained in the protocol. To clear the ambiguity contained in the designed protocol, we use LTS model to design the protocol for this interface link between CTC and SCADA, the LTS is an intermediate model for encoding the operational behavior of processes. And then, we verify automatically and formally the safety and the liveness properties through the model checking method. Especially, the modal ${\mu}$-calculus, which is a highly expressive method of temporal logic that has been applied to the model checking method. It will be expected to increase the safety, reliability and efficiency of maintenance of the signaling systems by using the designed protocol for railway signaling in Korea.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.11
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• pp.895-901
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• 2013

In this paper we propose design of a multi-protocol gateway middleware based on USN. The proposed multi-protocol gateway middleware defined the transmit messages format, and were used the USN module interface protocol for connect to external application MCU using the UART. In this case, the gateway was checks the communication state of Zigbee module with settings information, and setting Zigbee serial PDU format. The experimental results of the proposed multi-protocol gateway middleware were proved the efficiency of integrate protocol gateway to use the multi-protocol gateway than gateway to using the repeater through the power control and communications a controlled experiment.

• ETRI Journal
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• v.19 no.3
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• pp.303-315
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• 1997

This appendix deals with the Korean air interface standard, TTA-62, for CDMA Mobile Systems, (CMS) [1]-[2]. The standard has been set up by Telecommunications Technology Association (TTA) which is a standardization organization in Korea [3]. This standard is an important specification that should be determined prior to the development of a digital cellular system. The CMS has been developed on the basis of this standard and the papers published in this special issue are the results of the CMS development. This appendix also describes the technical commonality of these papers. It covers the outline of the air interface and protocol specifications. The outline includes its major characteristics, radio protocol architecture, functionalties, and call processing. A comparison is also given between TTA-62 and IS-95[4], a North American digital cellular standard.

• Industrial Engineering and Management Systems
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• v.8 no.1
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• pp.54-65
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• 2009

The existence of Internet revolutionized the computer and communications world. With the rising demand for accessing the Internet, the mobile technology has incorporated the use of Internet in mobile phones. Wireless Application Protocol (WAP) has combined two of the widest utilized technology today: mobile phones and Internet. This study aims to assess the existing WAP pages offered by the top service providers in the Philippines through usability testing experiments. The paper also aims to identify existing problems in WAP interface by focusing on the errors committed by the users. From the usability study, it was found out that common usability problems are wrong selection of links, unclear grouping of categories, wrong feedback, and redundant links. The type of service provider used is significant in determining the performance of users while experience in accessing WAP is insignificant.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.394-397
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• 2003

This paper has been studied a interworking signalling protocol between two hybrid networks by analyzing Satellite B-ISDN architecture, DSS2 Layer 3 Signalling protocol, B-ISUP protocol, S-BISUP protocol stack and so on. Also in the paper, messages and primitives have been defined for B-ISDN's Connection Type, Ownership and each protocol in order to connect point-to-multipoint. And then this paper has designed basic call procedures for OBP Satellite B-ISDN NNI interworking protocol, verified and implemented them.