Low-Power Based Coherent Acoustic Modem for High-Speed Communication in Underwater Sensor Networks

NAM, Heungwoo,AN, Sunshin The Institute of Electronics, Information and Comm 2009 IEICE TRANSACTIONS ON COMMUNICATIONS - Vol.92 No.12

<P>As the need for underwater communication has recently grown, an acoustic modem has become more necessary for the sensor nodes to perform effective underwater communication. To develop acoustic modems for effective underwater communication, some limitations must be overcome, such as the limited power supply and high cost of commercial acoustic modems. Recently, low-power, low-cost acoustic modems have been developed. However, the data rates of these modems are very slow. The objective of this work is to develop an acoustic modem capable of supporting high data rates. We introduce a coherent acoustic modem that uses waterproof ultrasonic sensors to process acoustic waves. The proposed modem is based on a low-power, low-cost, short-range concept, and it also supports a high data rate as confirmed by underwater experiments. Experimental results show that our modem has the best performance among all recently developed low-power modems.</P>

조도 제어용 ASK 및 FSK 전력선 모뎀의 성능 평가

박종연,최현희 강원대학교 정보통신연구소 2008 정보통신논문지 Vol.12 No.-

In this paper, two type of power line modems are evaluated to realize the lamp control system using the power line communication. One is FSK modem using DS/SS and the other is the manchester coded ASK modem. Both modems apply (7,4) hamming code to correct errors. There are two kinds of used loads ; the electronic ballast and the magnetic ballast. The Electronic ballast is for a 250Watt HID lamp, a 50watt florescent lamp and a 50watt induction lamp. The Magnetic ballast is for a 250watt HID lamp. Bit errors are measured between the main modem and the ASK or the FSK sub-modems in loads at equal distances. As a result, it is estimated that the FSK modem is more appropriate than the ASK modem in terms of the lamp dimming system. And we also concluded that the (7,4) hamming code is not suitable for ASK application In the lamp control system.

Multicarrier/Multirate modem providing channel de-assemble and assemble functions

Tanabe, Kazuhiro,Kobayashi, Kiyoshi,Ohata, Kohei,Ueba, Masazumi 통신위성우주산업연구회 2001 Joint Conference on Satellite Communications Vol.2001 No.-

A satellite communication system for enterprise Intranets must be able to support simultaneous multi-point connections among dispersed locations and to allocate satellite channels with the required data rates of each of the connections independently. To meet these requirements, the Multicarrier/Multirate Group Modem (MCMRM) for earth stations is proposed that can process multiple and various rate. MCMRM has the following features. 1. Supports simultaneous communications with hundreds of channels. (Maximum 768) 2. The prototype modem is roughly the same size of as the conventional single carrier modem. 3. To secure flexibility and scalability, the developed modem consists of independent modules. 4. Supports the allocation of bandwidth required over dispersed frequency bands, even if continuous frequency band is not available. MCMRM consists of a multi-rate filter bank and a group modem implemented on several FPGAs controlled by a timesharing system. Evaluations show that MCMRM has even higher BER performance than a conventional single carrier modem. This paper describes the architecture and processing method of MCMRM and performance evaluation results.

전력선/무선 통합 모뎀을 이용한 Door Lock의 원격 제어 시스템

박종연,이후찬,최원호 강원대학교 산업기술연구소 2005 産業技術硏究 Vol.25 No.B

In this paper we proposed the remote control system for the door lock by the unified modem with the wireless and the power line modem. We developed the management system program between the door-lock system and the proposed unified modem. The infrared communication system was used between the Door-Lock system and the power line modem. With the unified developed modem and the Door-Lock system, it is possible to control remotely the developed system in the internet service area.

환경 시설물의 광대역 통합모뎀 근거리 통신망 스위칭 기술연구

조주필,신재권,윤경화,이정훈 사단법인 한국위성정보통신학회 2014 한국위성정보통신학회논문지 Vol.9 No.4

Recently, environment facilities are able to manage real-time data collection and record management through integratedbroadband modem LAN switching technology. Therefore, it need more stable and efficient facility management. So, werequired practical use of environmental facilities convergence based on broadband integrated modem. In this paper, we proposed an integrated broadband modem LAN switching technology which can applicable to theenvironment facility. Also, we presented integrated broadband modem of design plan and communication system. And itreceived data inside of environment facility using the two communication methods(IEEE802.11x and IEEE802.15.4x). Then,our proposed integrated broadband modem LAN switching technology will prioritize processing data when emergency happenthrough collecting data, analysis data and processing. Lastly, we proved usefulness by experiment and simulation analysis. 환경시설물의 광대역 통합모뎀 근거리 통신망 스위칭 기술을 통하여 상시 실시간 자료 수집 및 이력관리가 가능함에 따라 안정적이고 효율적인 시설물 관리 및 광대역 통합모뎀을 기반으로 적용 가능한 신기술 융합의 환경 시설물의 실용화가 필요한 상황이다. 따라서 본 논문에서는 환경시설물에 적용 가능한 광대역 통합모뎀 근거리 통신망 스위칭 기술을 제시하였다. 광대역 통합모뎀의구축방안 및 통신방식을 제시하여 광대역 통합망 유비쿼터스 기반의 환경시설물 관리용 신기술 동향 및 기술을 분석하고,IEEE802.11x와 IEEE802.15.4x 두 가지 통신방식의 연동을 통하여 환경시설물 내 시설물로부터 수신되어지는 데이터의 수집, 해석및 처리를 통해 이상현상 발생 시 우선순위 부여 등의 워크플로우 기능과 다수의 측정 데이터를 사용자 정의 로직에 따라 서버로전송하는 기능을 모의실험하고 분석하여 그 유용성을 입증하였다

Direct-multicasting Satellite Communications System

Masaaki, Tabata,Toshihiro, Tsuchida,Hiroshi, Kazama 통신위성우주산업연구회 2004 Joint Conference on Satellite Communications Vol.2004 No.-

Satellite communications is a promising medium for multicasting services such as streaming media delivery. However, most of the current satellite multicasting systems use a star-type network with one transmitting earth station called a bub, which is generally located in an urban area. Therefore, it is difficult for small businesses located in rural areas to send their contents by using satellite multicasting network. To meet these demands, we developed the direct-multicasting satellite communications system (DMSCS), which can provides a full-mesh type satellite network easily and cost-effectively. DMSCS uses our newly developed multi-carrier/multi-rate modem called the group modem and a highly effective channel assignment control program. The group modem is an FDMA (Frequency Division Multiple Access) modem. It is composed of a control module, user interface modules, a multi-carrier/multi-rate modem (MCMRM) module, and IF up/down-converter module. Its features include simultaneous connections with 32 different points, communication at an arbitrary rate, and the use of a dispersed and discontinuous spectrum. The highly effective channel assignment control program is the operation program for DMSCS. It has scale flexibility and high functionality. This paper described the features of DMSCS, the architecture and performance evaluation of the group modem, and example of new services making the best use of the advantages of DMSCS.

수중 모뎀을 이용한 수중환경 관측

이기욱(Lee Kee Wook) 한국마린엔지니어링학회 2009 한국마린엔지니어링학회 학술대회 논문집 Vol.2009 No.-

Many scientists are interested in "underwater real-time data transferring system". However, there were problems of very difficult to install and low data quality and high cost in underwater data transferring system as like underwater cable, Inductive Modem, Acoustic Modem. Nowadays, The Acoustic modem applications are various, powerful, because the technical development was done and the cost is decreased. We do introduce various applications for "Underwater Monitoring System by Acoustic Modem Kit" during 3 years.

환경 시설물의 광대역 통합모뎀 근거리 통신망 스위칭 기술 연구

조주필,신재권,윤경화,이정훈 통신위성ㆍ우주산업연구회 2014 한국위성정보통신학회논문지 Vol.9 No.4

환경시설물의 광대역 통합모뎀 근거리 통신망 스위칭 기술을 통하여 상시 실시간 자료 수집 및 이력관리가 가능함에 따라 안정적이고 효율적인 시설물 관리 및 광대역 통합모뎀을 기반으로 적용 가능한 신기술 융합의 환경 시설물의 실용화가 필요한 상황이다. 따라서 본 논문에서는 환경시설물에 적용 가능한 광대역 통합모뎀 근거리 통신망 스위칭 기술을 제시하였다. 광대역 통합모뎀의구축방안 및 통신방식을 제시하여 광대역 통합망 유비쿼터스 기반의 환경시설물 관리용 신기술 동향 및 기술을 분석하고, IEEE802.11x와 IEEE802.15.4x 두 가지 통신방식의 연동을 통하여 환경시설물 내 시설물로부터 수신되어지는 데이터의 수집, 해석및 처리를 통해 이상현상 발생 시 우선순위 부여 등의 워크플로우 기능과 다수의 측정 데이터를 사용자 정의 로직에 따라 서버로전송하는 기능을 모의실험하고 분석하여 그 유용성을 입증하였다 Recently, environment facilities are able to manage real-time data collection and record management through integratedbroadband modem LAN switching technology. Therefore, it need more stable and efficient facility management. So, werequired practical use of environmental facilities convergence based on broadband integrated modem. In this paper, we proposed an integrated broadband modem LAN switching technology which can applicable to theenvironment facility. Also, we presented integrated broadband modem of design plan and communication system. And itreceived data inside of environment facility using the two communication methods(IEEE802.11x and IEEE802.15.4x). Then,our proposed integrated broadband modem LAN switching technology will prioritize processing data when emergency happenthrough collecting data, analysis data and processing. Lastly, we proved usefulness by experiment and simulation analysis.

수중 환경 및 생태 실시간 모니터링을 위한 초소형 수중 음향통신 모뎀 개발

전준호(Jun-Ho Jeon),박성준(Sung-Joon Park) 大韓電子工學會 2011 電子工學會論文誌-CI (Computer and Information) Vol.48 No.6

과거 유선 및 비실시간으로 구축되던 수중 생태 모니터링 자원 탐사 시스템 등은 수중 무선 센서네트워크 시스템 기술의 연구 개발을 통해 실시간 정보 송수신이 가능한 디지털 융합의 형태로 진화될 수 있다. 이를 가능하게 하는 핵심 기술 중의 하나는 배터리에 의해 동작하는 초소형 수중 음향통신 모뎀 구현 기술이며 본 연구에서는 무지향성 수중 음향 트랜스듀서를 탑재한 초소형 수중 음향통신 모뎀을 설계하고 개발한다. 또한 구현된 수중 모뎀의 성능을 검증하기 위하여 경기도 양평의 북한강에서 송수신 실험을 수행하고 그 결과를 분석한다. 실험 결과에 따르면 개발한 모뎀은 최대 250 m의 거리에서 200 bps의 전송속도와 7.8*10-5의 비트오율로 무선 데이터 송수신이 가능하였다. 개발된 수중 모뎀은 향후 수중 무선 센서네트워크를 활용한 다양한 응용 시스템에 적용 가능할 것으로 기대된다. Systems for underwater environment monitoring and natural resources can be considered as a part of digital convergence where real-time data transmission is possible with the help of underwater wireless sensor network (UWSN). One of key technologies required for the deployment of the systems is underwater acoustic micro modem. In this work we design and implement an acoustic modem equipped with a commercial omnidirectional transducer. We also make experiments at the northern Han river for the verification of the developed modem. According to the experiments the modem supports the working distance of 250 m and the data rate of 200 bps with a negligible bit error rate. It is expected that the acoustic modem can be used for various applications based on UWSN in a near future.

HFC 망에서의 고속 멀티미디어 전송시스템 개발

손병희,남의석,양효식,Son, Byoung-Hee,Nahm, Eui-Seok,Yang, Hyo-Sik 한국융합신호처리학회 2011 융합신호처리학회 논문지 (JISPS) Vol.12 No.2

Hybrid Fiber Coax (HFC) network의 전송 능력은 xDSL과 비교하여 우수하지만, HFC network에서 아직도 케이블 모뎀을 사용하기 때문에 고화질의 영상을 전송할 때는 속도가 느려진다. 본 논문에서는 HFC망에서 사용하는 케이블 모뎀의 성능을 개선하기 위해서 개발된 하향 전용 IP-cable sender와 IP-cable modem을 제시하였다. 개발된 시스템은 HFC 망에서 30 Mbps 급의 IP 방송을 지원하고, 21 Mbps 속도의 고화질 트랜스포트 스트림을 사용하여 장시간 고화질 서비스를 제공한다. The transfer capability of HFC (Hybrid Fiber Coax) network is superior to xDSL. HFC network, however, is not suitable for transferring high quality video due to cable model interfaces. For the services of high quality IPIV or VOD, the extra exclusive downstream transfer system is required without upgrading pre-equipped cable modem and service capability. This paper is aimed to develop the extra exclusive downstream transfer system not changing existing cable modem system but providing same quality of services. This system is composed of the extra exclusive downstream IP-cable sender and modem. This sender and modem have 30 Mbps transfer capability and HDTV stream can be served in the Cable TV network using 21 Mbps HDTV transport stream.