The Experts below are selected from a list of 144 Experts worldwide ranked by ideXlab platform
Alain Reineix - One of the best experts on this subject based on the ideXlab platform.
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Amélioration des performances des systèmes à haut débit par une méthode de réduction de la diaphonie dans les câbles multiconducteurs de télécommunications
Annales Des Télécommunications, 2007Co-Authors: Sandrine Roblot, Ahmed Zeddam, Alain ReineixAbstract:dsl (Digital Subscriber Line) technology provides low cost access to the consumers and sources of information for any one subscribing to classical analogical telephony. Indeed x dsl services enable high-speed digital transmission on conventional telephone lines. For sixteen years that the internet has risen, a great number of offers proposing increasing bit rate have been developed. Considering this increasing demand of high bit rate access, Telecommunication operators perpetually work on finding solutions to optimize the copper lines channel. In that way, we present here a new method of crosstalk reduction in a multiconductor Telecommunication Cable. Interests and limitations of this method are presented and some simulations on a frequency band extending to 30 MHz will picture those theoretical results. Les technologies x dsl (Digital Subscriber Line) sont la solution immédiate à l’accès aux hauts débits pour tout abonné à la téléphonie classique. Leur particularité est en effet d’utiliser le réseau en cuivre existant, initialement conçu pour la transmission de la parole. Depuis 16 ans que le web a vu le jour, les offres à des services de plus en plus gourmands en débit se sont développées. Face à cette demande toujours croissante de communications à haut débit, les opérateurs de télécommunications sont perpétuellement à la recherche de solutions pour optimiser la transmission sur paire de cuivre. Dans ce sens, nous traitons ici de la réduction de la diaphonie au sein des câbles multiconducteurs de télécommunication par le biais d’une méthode basée sur la théorie des lignes de transmission. Les intérêts et limitations de cette méthode viennent compléter des simulations effectuées sur une bande fréquentielle s’étendant jusqu’à 30 MHz, fréquence maximale utilisée par les systèmes x dsl .
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On Eliminating Crosstalk in a Multiconductor Telecommunication Cable
2007 IEEE International Symposium on Electromagnetic Compatibility, 2007Co-Authors: Sandrine Roblot, Ahmed Zeddam, Alain ReineixAbstract:This paper presents a method of crosstalk reduction in a Telecommunication Cable composed of multiple conductors. Initially, an electromagnetic and topologic code is implemented to simulate the multi conductor transmission line when injecting the different signals following a particular combination of modes. Then, the far end crosstalk voltage is determined. With such a method, it appears that is possible to decrease crosstalk on the line. To picture those results for xDSL transmissions, the crosstalk results obtained by simulations are injected on a VDSL channel. Thanks to dedicated software, we can therefore estimate the bit rate and reach improvement obtained for this VDSL channel.
Sandrine Roblot - One of the best experts on this subject based on the ideXlab platform.
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Amélioration des performances des systèmes à haut débit par une méthode de réduction de la diaphonie dans les câbles multiconducteurs de télécommunications
Annales Des Télécommunications, 2007Co-Authors: Sandrine Roblot, Ahmed Zeddam, Alain ReineixAbstract:dsl (Digital Subscriber Line) technology provides low cost access to the consumers and sources of information for any one subscribing to classical analogical telephony. Indeed x dsl services enable high-speed digital transmission on conventional telephone lines. For sixteen years that the internet has risen, a great number of offers proposing increasing bit rate have been developed. Considering this increasing demand of high bit rate access, Telecommunication operators perpetually work on finding solutions to optimize the copper lines channel. In that way, we present here a new method of crosstalk reduction in a multiconductor Telecommunication Cable. Interests and limitations of this method are presented and some simulations on a frequency band extending to 30 MHz will picture those theoretical results. Les technologies x dsl (Digital Subscriber Line) sont la solution immédiate à l’accès aux hauts débits pour tout abonné à la téléphonie classique. Leur particularité est en effet d’utiliser le réseau en cuivre existant, initialement conçu pour la transmission de la parole. Depuis 16 ans que le web a vu le jour, les offres à des services de plus en plus gourmands en débit se sont développées. Face à cette demande toujours croissante de communications à haut débit, les opérateurs de télécommunications sont perpétuellement à la recherche de solutions pour optimiser la transmission sur paire de cuivre. Dans ce sens, nous traitons ici de la réduction de la diaphonie au sein des câbles multiconducteurs de télécommunication par le biais d’une méthode basée sur la théorie des lignes de transmission. Les intérêts et limitations de cette méthode viennent compléter des simulations effectuées sur une bande fréquentielle s’étendant jusqu’à 30 MHz, fréquence maximale utilisée par les systèmes x dsl .
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On Eliminating Crosstalk in a Multiconductor Telecommunication Cable
2007 IEEE International Symposium on Electromagnetic Compatibility, 2007Co-Authors: Sandrine Roblot, Ahmed Zeddam, Alain ReineixAbstract:This paper presents a method of crosstalk reduction in a Telecommunication Cable composed of multiple conductors. Initially, an electromagnetic and topologic code is implemented to simulate the multi conductor transmission line when injecting the different signals following a particular combination of modes. Then, the far end crosstalk voltage is determined. With such a method, it appears that is possible to decrease crosstalk on the line. To picture those results for xDSL transmissions, the crosstalk results obtained by simulations are injected on a VDSL channel. Thanks to dedicated software, we can therefore estimate the bit rate and reach improvement obtained for this VDSL channel.
Dong Chul Park - One of the best experts on this subject based on the ideXlab platform.
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Measurement of transfer impedance on shielded multiconductor Telecommunication Cables using IEC 96-1 line injection method
2003 IEEE International Symposium on Electromagnetic Compatibility 2003. EMC '03., 2003Co-Authors: Ho-seok Oh, Dong Chul ParkAbstract:As the high-speed data communications such as xDSL using the existing copper Cable come into wide use, the electromagnetic coupling characteristics of Telecommunication Cables become more significant. In order to describe the screening performance of Telecommunication Cable, the transfer impedance of Cable shield is required. This paper describes the transfer impedance for Telecommunication Cables using the line injection method of IEC 96-1. Results are analyzed to show how the positioning of the injection line and of the inner conductor of the Cable under test (CUT) affect the value of transfer impedance and how the transfer impedance is changed with the frequency.
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Effect of an overhead ground wire to lightning-induced voltages on a Telecommunication Cable
2000 Asia-Pacific Microwave Conference. Proceedings (Cat. No.00TH8522), 2000Co-Authors: Jae Cheol Ju, Dong Chul ParkAbstract:The effect of an overhead ground wire on lightning-induced voltages on a Telecommunication Cable is calculated by multiconductor transmission line equations using the finite-difference time-domain (FDTD) method. The induced voltages in the presence of a ground wire with an additional grounding point are also examined by an equivalent single-wire line representation. The simulation results show that the ground wire with additional grounding can reduce the magnitude of the induced voltages on a Telecommunication subscriber Cable.
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FDTD analysis on a Telecommunication Cable immersed in lightning EM fields
IEEE International Symposium on Electromagnetic Compatibility. Symposium Record (Cat. No.00CH37016), 2000Co-Authors: Jae Cheol Ju, Dong Chul ParkAbstract:A Telecommunication subscriber Cable is a bundle of twisted-pair wires terminated with gas discharge tube arresters. The lightning-induced voltages on multiple twisted-pair wires over a lossy ground are calculated by an equivalent single-wire line representation. The simplified single-wire line representation shows a good agreement with the result of the twisted pairs of wires. Additionally, the transient response of a gas discharge tube arrester is also simulated by the finite-difference time-domain (FDTD) method.
Hajimu Kinoshita - One of the best experts on this subject based on the ideXlab platform.
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submarine Cable obs using a retired submarine Telecommunication Cable geo toc program
Physics of the Earth and Planetary Interiors, 1998Co-Authors: Junzo Kasahara, Hisashi Utada, Toshinori Sato, Hajimu KinoshitaAbstract:Abstract In order to study the Earth's structure and subduction zone tectonics, seismic data from the oceanic region are extremely important. The present seismograph distribution in the oceanic region, however, provides a very poor coverage. To improve this poor seismic coverage, a Cable OBS system using a retired submarine Telecommunication Cable is proposed. The GeO-TOC Cable runs from Ninomiya, Japan, to Guam through the Izu-Bonin forearc and the Marina Trough. The total length of the Cable is 2659 km. An OBS, IZU, using the GeO-TOC Cable, was successfully installed at the landward slope of the Izu-Bonin Trench in January 1997. The IZU OBS is located approximately 400 km south of Tokyo. The installation method is similar to repair work on submarine Cables. The IZU OBS is equipped with three accelerometers, a hydrophone, a quartz pressure gauge, and a quartz precision thermometer with a few temperature sensors to monitor overheating of the internal electronics. After installation, the voltage increase is 90 V when the current is maintained at a constant 370 mA. Data from accelerometers are digitized by 24-bit A/D converters and sent to Ninomiya at 9600 bps for each component. Hydrophone data are sent to Ninomiya as analog signals using the AM (Amplitude Modulation) method for safety reasons. Hydrophone data are digitized at the shore station. Other slow-rate data are multiplexed and sent to the shore at 9600 bps. The instrument can be controlled by a shore computer. All data will be transmitted from Ninomiya to Tokyo and combined with other existing seismic data.
L.l. Whitcomb - One of the best experts on this subject based on the ideXlab platform.
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Underwater robotics: out of the research laboratory and into the field
2002Co-Authors: L.l. WhitcombAbstract:The development of two new classes of commercial underwater\nrobotic vehicles-deep diving work-class remotely operated vehicles and\nsurvey-class autonomous vehicles-is being driven by the needs of deep\nwater oil production and deep ocean Telecommunication Cable operations.\nThe paper presents a survey of the present state and future directions\nof commercial underwater robotics, examines principal technical\nchallenges, and outlines new enabling technologies for commercial\nunderwater robotic vehicles
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ICRA - Underwater robotics: out of the research laboratory and into the field
Proceedings 2000 ICRA. Millennium Conference. IEEE International Conference on Robotics and Automation. Symposia Proceedings (Cat. No.00CH37065), 2000Co-Authors: L.l. WhitcombAbstract:The development of two new classes of commercial underwater robotic vehicles-deep diving work-class remotely operated vehicles and survey-class autonomous vehicles-is being driven by the needs of deep water oil production and deep ocean Telecommunication Cable operations. The paper presents a survey of the present state and future directions of commercial underwater robotics, examines principal technical challenges, and outlines new enabling technologies for commercial underwater robotic vehicles.
