• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.11b
• /
• pp.1281-1284
• /
• 2002

본 논문은 인터넷을 이용한 음성통신 서비스를 제공하기 위해 사용되는 VoIP 시스템 칩 설계 및 기능 검증을 위한 보드 개발에 관한 것이다. 구성이 간단한 시스템을 구현하기 위하여 32 비트 RISC 프로세서인 ARM922T 프로세서 코어를 중심으로 IP 망 접속 기능, 톤 발생 및 음성신호 접속기능과 다양한 사용자 정합 기능을 가지는 VoIP 시스템 칩을 설계하고, 이 칩의 기능을 검증하기 위하여 시험 프로그램 및 통신 프로토콜을 개발하였으며, 각종 설계 및 시뮬레이션 툴을 사용하고 ARM922T와 FPGA가 결합된 Excalibur를 사용한 시험용 보드를 개발하여 시험하였다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2012.11a
• /
• pp.777-779
• /
• 2012

인터넷의 확산으로 인해 전송, 서비스 및 보안과 관련된 많은 장비들이 개발되고 출시되고 있다. 서비스 및 보안과 관련된 장비들은 새로운 개발과 급속한 도입으로 인해 적절한 성능측정방법의 부재로 인해 많은 혼란과 문제들을 가져오기도 했었다. 이에 장비를 도입하는 기관들은 전문 시험기관의 시험과 평가를 거쳐 발행된 성적서나 보고서를 참고하거나 직접 벤치마킹테스트를 거쳐 도입을 결정하고 있다. 본 논문에서는 IP 네트워크 장비들의 성능측정을 위한 방법들을 분석하고 표준으로 제정된 시험 방법론을 분석하여 시스템 성능측정을 위한 메트릭을 제시하고자 한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.13 no.3
• /
• pp.111-118
• /
• 2013

The connection based TCP protocol provides reliable packet delivery, but it takes certain overhead compare to the connection-less UDP protocol. Thus, 3GPP devise the upper-layer RLC protocol which provides reliability based upon the UDP protocol. Consequently, each implement of a base station and/or mobile terminal require the development of the RLC protocol, and it must qualify various interoperable tests. In this paper, we implement a testbed which verifies the RLC protocol under various packet losses/inversion circumstances of networks. Finally, we propose our testbed as the RLC protocol tester for the developments.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.11 no.3
• /
• pp.99-105
• /
• 2011

Typically, quick and easily deployed communication for a clear disaster management is required in a disaster situation. But it is not easy because lack of backbone network and poor conditions of disaster site. it is possible to obtain a wide service coverage and low power with portable wireless mesh network technology. In this paper, we developed portable wireless mesh network gateway with a network processor and evaluate it's performance including throughput, latency delay, packet loss, etc. The experiments show our wireless mesh network gateway has basic performance and can be used in various environments like disaster site.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.11 no.2
• /
• pp.237-244
• /
• 2011

Vehicular communications extend their application areas by combining communication technologies with roads/vehicles, and one of major applications is Smart Highway project. Smart Highway is a new advanced highway system which enhances the current highway system in Korea by improving reliability, safety and convenience. In this paper, we introduce wireless access technologies for vehicular communications especially focusing on Smart Highway. We first introduce the overall communication system architecture and the basic service and communication requirements for Smart Highway. Then, we discuss wireless access technologies including L2-level hand-over scheme. In addition, the results of experimental measurements of Wireless Access in Vehicular Environments (WAVE) system are introduced.

• The KIPS Transactions:PartA
• /
• v.11A no.3
• /
• pp.109-114
• /
• 2004

Increasing popularity of WLAN and advancement of WPAN allow user to connect to the Internet easily today. The increasing of number of networking mobile device such as laptop and PDA requires computing devices to share high speed Internet line or work on networks in most cases. This has stimulated the demand of access point that supports multiple network interfaces. This paper describes the process of design, implementation and test of the wired/wireless integrated access point that supports multiple network interfaces such as wired LAN, wireless LAN, Bluetooth, and Broadband network. We designed and developed the hardware system and protocol software to integrate heterogeneous network. The system has shown compatibility with standard specification and good performance through testing with various network devices.

• Proceedings of the KIPE Conference
• /
• 2004.07b
• /
• pp.733-737
• /
• 2004

오랫동안 연구되어 오던 전력선 통신 기술은 1990 년대 중반에 이르러, 모뎀 기술을 응용한 10kbps급의 저속 전력선통신 기술이 개발되어 상용화 수준에 근접한 제품이 등장하기 시작했다. 반면 고속 전력선통신 기술 분야는 관심을 갖기 시작한 시기가 저속 분야에 비해 상대적으로 늦지만, 국내외 여러업체에서 고속 전력선통신 솔루션을 개발, 상용화에 근접한 칩셋 및 제품들을 선보이고 있다. 국내에서는 산업자원부의 중기거점 사업으로 수행중인 "50Mbps급 고속 전력선 통신망 개발사업"과 관련하여 고속 전력선 통신망 장치를 실용화 할 수 있도록 집단주택과 단독주택 형태의 인터넷 시범사업에 관한 연구가 활발히 수행중이다. 본 연구에서는 실제 수용가 환경인 단독주택 약 20세대에서 수행한 인터넷 시범사업을 통하여 개발된 전력선 통신 모뎀과 시스템에 대한 성능 측정을 수행한다. 이를 토대로 현 단계에서의 기술을 분석하고, 전력선 통신망에 대한 운영상의 적정 노드 및 가입자망 전송 섹터범위 등의 종합적인 평가에 대한 내용 등 실증시험망 구축 및 운용에 대한 결과와 향후 활용방안에 대해서 기술하고자 한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.10 no.5
• /
• pp.237-244
• /
• 2010

In this paper, the dual parabolic cylindrical reflector systems are analyzed as the reflector system for the CATR(Compact Antenna Test Range) facility. The near-field at the test zone of the CATR is calculated by using the PO(Physical Optics) approximation. The CATR has to provide an uniform plane wave with the minimum amplitude and phase ripple and the low cross polarization. Therefore, in this paper, the near-field pattern are calculated, and the ripple and taper of the field and the cross polarization are investigated with the position of the subreflector and the test region. It is confirmed that the analysis results can be used for the design of the CATR with the dual parabolic cylindrical reflector.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.18 no.5
• /
• pp.97-102
• /
• 2018

In this paper, W-band Waveform Generator for compact radar has been designed and fabricated. DDS (Direct Digital Synthesizer) is applied to generate CW (Continuous Wave) and FMCW (Frequency Modulation Continuous Wave) waveform at high speed. We designed two LO (Local Oscillator) paths for functions of distance delay and distance tracking tests at the prpposed system without extra test equipment. Two mode selections are provided by switch. It is observed that fabricated waveform generator performs -91 dBc/Hz phase noise at offset 1 kHz and -63.2 dBc spurious. Proposed W-band Waveform Generator is expected to apply for W-band compact radar transceiver module.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.11 no.6
• /
• pp.49-56
• /
• 2011

Leisure bicycles are fabricated in a variety of ways these days. Although, the bicycles are designed and manufactured in a variety of ways by numerous companies, customer has a difficulty in gaining information of bicycle which suits them. Accordingly most of buyers purchase bicycle considering body size. Employing the method is one of the ways to decide bike size on the ground of standard body measurement. However, the method above to purchase bicycle is not appropriate for customer considering his/her body. The research mainly aims to design bicycle which allows buyer to adjust optimal design system by himself/herself considering his/her body size. In addition, a device employing fuzzy controller implemented bicycle run test. Using on the result, the research explored an optimal bicycle system which makes a decision whether a bicycle fits body of customer.