• The Transactions of the Korea Information Processing Society
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• v.5 no.3
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• pp.774-784
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• 1998

본 논문은 현재 국내에서 개발되고 있는 광대역종합정보통신망(HAN/B-ISDN: HighlyAdvaned Network/Broadband Integrated Services Digital network)의 신호능력을 향상시키기 위한 요구 사항들과 정보 모델링에 관한 시나리오들을 제시하고 있다. 이러한 요구 사항들은 동등 대 동등과 계층 대 계층 신호 프로토콜에 사용될 수 있으며, 신호 능력 향상에 EK른 B-ISDN 연결형 베어러 서비스들은 Sb/Tb 참조 점에서 연결된 둘 또는 그 이상의 파티들 사이에서 B-ISDN 가상 경로, 가상 채널, 또는 공통 루트 연결 그룹 연결을 통하여 사용자 정보의 전달을제한 없이 제공할 수 있다 또한 본 논문에서는 현재 적용되고 있는 국내 B-ISDN에서 신호 능력을 향상 시키는 방안으로써 호 관련 정보 흐름을 정보 모델링을 통하여 제안한다. 본 논문을 통하여 지속적으로 작성되고 개발되는 모든 국내 B-ISDN 장치들이 단계별로 보다 충실할 수 있고, 추후 NNI에서의 신호 방식 호 절차를 통한 광대역 텔레 서비스를 처리할 수 있으며, 단말 사용자에게는 최대한의 편의를 제공할 수 있을 것이다.

• Information and Communications Magazine
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• v.17 no.1
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• pp.58-63
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• 2000

새 천년을 맞이하여 국내 이동전화 시장은 규모와 기술적 측면에서 놀랄만한 변화 를 겪게 될 것이다. 음성중심의 2세대 이동전화 서비스는 보급율이 50%를 넘어서며 포화수 준에 근접하고 있으며, 앞으로 무선데이타 통화량이 크게 증가하여 3~4년 후에는 총 통화량 의 50% 이상을 점유할 것으로 예측된다. 통신사업자들은 통신망의 광대역화와 글로벌화, IP Network 화를 더욱 강력하게 추진하고 있으며, 올 연말로 예정된 IMT-2000 사업자 선정은 이러한 추세를 더욱 가속화시킬 것으로 전망된다. 특히, 인터넷과 이동전화의 융화는 인간의 삶과 문화를 한순간에 변모시킬 혁명적 위력을 내포하고 있다. 정보화 시대를 향한 정보통 신업계의 대변혁이 그 절정을 향해 가속도를 붙이기 시작한 것이다. 신세기통신은 이러한 변화와 혼돈의 거친 물결 속에서 21세기 '정보통신 업계의 강자'로 도약하기 위한 힘찬 항해 를 진행하고 있다. 2000년 상반기까지 IS-2000시스템을 구축하여 최대 144kbps 수준의 고속 데이타 서비스를 제공하는 한편 i-TOUCH 017 컨텐츠 (Contents)를 한층 다양화, 첨단화 하는 등 본격적인 이동인터넷 사업을 전개해 나갈 것이다. 또 CDMA 국제 자동로밍 서비스 를 일본, 미국, 유럽 등 전세계로 확대하여 017 서비스의 글로벌화를 이룩할 계획이다. 이러 한 통신망 진화와 이동 인터넷 사업의 상당 부분을 SK텔레콤과 함께 추진하게 될 것이며 이러한 양사간의 전략적 제휴에 따른 시너지 효과는 오는 연말 IMT-2000 사업권의 성공적 확보로 이어질 것으로 기대된다. 21세기 정보통신산업은 광대역 통신망으로 대변되는 하드 웨어와 인터넷 컨텐츠로 대변되는 소프트웨어가 서로 융화되는 방향으로 발전할 것이다. 이에 따라 고객의 서비스 만족도나 사업자 선택 기준은 기존 통화물질 중심에서, 사업자가 제공하는 컨텐츠의 다양성이나 편리성으로 변화하는 것이 국적을 바꾸는 것보다 어려운 시 대가 멀지 않은 미래에 도래할 것이다. 신세기 통신 과 SK 텔레콤에는 현재 1,300만명이 넘 는 고객이 있으며. 이들 고객은 어 이상 음성통화 중심의 이동전화 고객이 아니라 신세기 통신과 SK텔레콤이 함께 구축해 나갈 거대란 무선 네트워크 사회에서 정보화 시대를 살아 갈 회원들이다. '컨텐츠의 시대'가 개막되는 것이며, 신세기통신과 SK텔레콤은 선의의 경쟁 과 협력을 통해 이동인터넷 서비스의 컨텐츠를 개발해 나가게 될 것이다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.10B
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• pp.939-945
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• 2008

Tn this paper we described the process and the results of an implementation of Internet terminal using G.729.1 wideband speech codec for next generation network. For this purpose firstly we chose a high performance RISC application processor having DSP features for speech codec processing and enhanced Multimedia Accelerator(eMMA) function for video codec. In the implementation of this terminal, we used G.729.1 codec recently standardized in ITU-T which is a new scalable speech and audio codec that extends 0.729 speech coding standard. To adopt G.729.1 codec to this terminal we transformed most of the fixed point C codes which require more complexity into assembly codes so as to minimize processing time in the processor. As a result of this work we reduced the execution time of the original C codes about 80% and operated in real time on the terminal. For video we used H.263/MPEG-4 codec which is supported by the eMMA with hardware in the processor. In the SIP call processing test connected to real network we obtained under looms end-to-end delay and 3.8 MOS value measured with PESQ instrument. Besides this terminal operated well with commercial terminals.

• Journal of Digital Convergence
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• v.13 no.10
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• pp.327-335
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• 2015

Wireless mesh networks for public safety and disaster have been developing in a direction from TETRA(TErrestrial Trunked RAdio) to take advantage of the Public Safety-LTE(Long Term Evolution) technology. In Korea, the Disaster Safety Network Building Project has been promoted in order to unify disaster communication systems among disaster response agencies. In this study, the trends of the network construction for national disaster communication and corresponding representative cases of overseas have been analyzed. Through this process, the disaster communication area in line with the purpose of communications. As a result, the disaster communication can be divided into five distinctive areas: the control, the response, the on-site, the victim and the alarm communications. Based on the re-designed communication areas, quality requirements have also been re-organized in this study. Ultimately the construction method for the Disaster Communication systems without exclusion zone will be presented.

• The Journal of the Korea institute of electronic communication sciences
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• v.1 no.1
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• pp.70-80
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• 2006

The large portion of communication service areas move from a legacy wire-line voice service to mobile data service. For the purpose of satisfaction on market need, many communication systems should be installed and upgraded based on a mobile wide-band transmission facility. Recently, large part of communication service is based on internet protocol by packet switch techniques and required new technologies such as multimedia processing, QoS achievement, and mobility managememobile communication network such as IS-95A/B and CDMA2000-1X. In this paper, I analyzed the network architecture and service provision methods. in CDMA2000-1X nt. In korea, a CDMA communication technique is standardized for digital mobile communication systems. By using the analysed results, I will extract an efficient method for network evolution and a core technique for next generation mobile communication network.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.2
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• pp.265-275
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• 2004

In this paper, an OFDM-CDMA broadband system is considered for a possible candidate of fixed wireless broadband access network applications. With an emphasis on a preamble design for multi-channel separation, we address a channel estimation based on the time-domain windowing and its imperfectness in OFDM-based multiple-antenna transmission systems. By properly designing each preamble for multiple antennas to be orthogonal in the time domain, the channel estimation can be applied to the ETSI HlPERLAN/2 and IEEE-802.11a standards in the case of more than two transmit antennas. Also, an effect of diversity techniques on the performance of OFDM-CDMA based broadband wireless access networks is investigated and the maximum achievable diversity gain for a two-path Rayleigh fading environment is evaluated Simulation results show that the OFDM-CDMA system applying a space-time-frequency diversity with a full-rate full diversity code can give the diversity of D = 4 and D = 8 for both multi-user cases of maximum user and half user capacities, respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.5
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• pp.926-932
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• 2007

Various research groups proposed various architecture of hardware VPN for the high performance VPN system. However, the VPN based on hardware researcher are focused only on the encryption acceleration. Soft based VPN is only useful when the network connection is slow. We have to consider the hardware performance (encryption/decryption processing capability, packet processing, architecture method) to implement hardware based VPN. In this paper, we have analysed architecture of hardware, consideration and problems for high-speed VPN system, From the result, we can choose the proper design guideline.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.10
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• pp.1945-1956
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• 1994

In this paper, a multiaccess network protocol for high-speed communication is proposed, which enables multimedia sevices with integrating the existing networks. We examine the traffic control mechanisms and configurations for the network architecture and compare with various protocols which are suitable to high speed LAN/MAN and propose an adaptive access control mechanism. ATMR has low channel utilization due to window size reset time, and that MetaRing is very sensitive over the change of traffic load. This suggested protocol, however, has quite a good performance for that situation by adding adaptive parameter condition. This mechanism may introduce a model of small-scaled Broadband Integrated Service Network and be used as an internetworking system for the ATM network.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.8
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• pp.1092-1097
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• 2011

Data communications at sea are done by the traditional radio and satellite carriers. Because of the restrictions on the data rate and cost of the carriers, a novel data communication system at sea is needed. Nowadays the efforts to make use of the broadband land carriers at sea have been pursued. This paper proposes a routing scheme (NTCR) using the various carriers on land for a MANET model at sea. The NTCR scheme optimizes the route using a chosen carrier by taking considerations of normalized transmission characteristics (NTC) of applications and carriers. The NTCR scheme is compared with the MWR (max-win based routing) scheme.

• Journal of the Korea Convergence Society
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• v.8 no.11
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• pp.85-91
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• 2017

This paper concerns the design of a matching module system enabling the RF signal to be harmonized between the new base stations (RRH) and the repeater in the same frequency band of the asynchronous transfer network. This matching system controls the RF Gain Control of the module while monitoring the quality of the quality. Additionally, the RF environment has been adapted accordingly to adjust the RF Gain Control to match the receiver characteristics of the relay. As a result of this study, we improved the quality of the interface between the new base stations and existing relays.