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- Dias,, Jacklyn, et al.
(författare)
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Improving the Performance Evaluation of ADSL systems by using a Modem Diagnosis Methodology
- 2006
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Ingår i: Simpósio Brasileiro de Microondas e Optoeletrônica – Congresso Brasileiro de Eletromagnetismo.
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Konferensbidrag (refereegranskat)abstract
- This paper presents test methodologies to measure and evaluate performance of ADSL modems which take into account loss of packet rate, bit rate, and latency in transporting ADSL service scenario. This evaluation method can be used by ADSL provider (CO - Central Office) to guarantee the system quality and avoid low performance of service. In order to present this evaluation method, this paper considers a traffic generator, modems under test, a telephony local loop carring ADSL service, and DSLAM as the lab setup to perform such tests.
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| 3. |
- Magesacher, Thomas, et al.
(författare)
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Limits of Ultra-Wideband Communication Over Copper
- 2006
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Ingår i: Proc. Intl. Conference on Communication Technology (ICCT) 2006. - 1424408016 ; , s. 1437-1440
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Konferensbidrag (refereegranskat)abstract
- Wireline communication using the copper plant is one of the major access techniques. The shorter the wires, the larger is the frequency band that can be exploited in an economically feasible way. Several technologies using frequency bands up to 30MHz have been standardized during the last decade. Properties of the wireline channel for frequencies above 30MHz are to a large extent unexplored. This paper investigates the limits of "ultra-wideband" communication over very short copper cables in terms of exploitable bandwidth and data rate. Extrapolations of standard cable models, whose validity has been verified by means of measurements, are used for channel modeling. The CISPR 22 standard forms the basis for the analysis of ingress and egress.
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| 4. |
- Magesacher, Thomas, et al.
(författare)
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Measurement and modeling of short copper cables for ultra-wideband communication
- 2006
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 6390, s. 39006-39006
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Konferensbidrag (refereegranskat)abstract
- High-speed communication using the copper network, originally installed for telephony, is one of the dominant Internet access techniques. Several variants of a technology referred to as digital subscriber line (DSL) have been developed, standardized and installed during the last two decades. Essentially, DSL achieves high rates by exploiting wide bands of the copper cable channel. The shorter the cable, the wider the band that can be used efficiently for communication. Current DSL standards foresee the use of bands up to 30MHz. Cable properties have been studied by means of measurements, characterization and modeling up to frequencies of 30MHz. Recent investigations have shown that it is feasible both from technical and from economical point of view to exploit very short cables (up to 200m) even further and use bands above 30MHz. A prerequisite for further evaluation and the design of such ultra-wideband copper (UWBC) systems is the extension of existing cable models to higher frequencies. This paper presents wideband measurement results of insertion loss and crosstalk coupling in a 10-pair cable of various length values for frequencies up to 200MHz. We compare the results with extrapolations of cable models that are established in the 30MHz-range.
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| 5. |
- Magesacher, Thomas, et al.
(författare)
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Modeling and measurement of short copper cables for ultra-wideband communications
- 2006
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Ingår i: Proc. SPIE OpticsEast Broadband Access Communication Technologies.
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Konferensbidrag (refereegranskat)abstract
- High-speed communication using the copper network, originally installed for telephony, is one of the dominant Internet access techniques. Several variants of a technology referred to as digital subscriber line (xDSL) have been developed, standardized and installed during the last two decades. Essentially, xDSL achieves high rates by exploiting wide bands of the copper cable channel. The shorter the cable, the wider is the band that can be used efficiently for communication. Current xDSL standards use bands up to 18MHz. Cable properties have been studied by means of measurements, characterization and modeling up to frequencies of 30MHz. Recent investigations have shown that is feasible both from technical and from economical point of view to exploit very short cable (up to 300m) even further and use bands above 30MHz. A prerequisite for further evaluation and the design of such ultra-wideband copper (UWBC) systems is the extension of existing cable models to higher frequencies. This paper presents wide-band measurement results of insertion loss and crosstalk coupling in a 10-pair cable of various length values for frequencies up to 400MHz. We compare the results to extrapolations of cable models that are established in the 30MHzrange.
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| 9. |
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| 11. |
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| 12. |
- Souza, Lamartine, et al.
(författare)
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Impact of Non-Stationary Noise on xDSL Systems: an Experimental Analysis
- 2007
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Ingår i: Proceedings of SPIE, the International Society for Optical Engineering. - : SPIE. ; 6603
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Konferensbidrag (refereegranskat)abstract
- Broadband services require data rates that can only be achieved by using relatively high spectrum frequencies. At such high frequencies, the DSL (Digital Subscriber Line) signal is more susceptible to external noise sources, such as radio frequency interference and impulsive noise. This paper aims to characterize how the impulsive noise impacts on services and applications for a broadband system using an ADSL2+ loop. The first approach was to use the impulsive noise defined in the standards G.996.1 (Test Procedures for DSL Transceivers) from ITU-T and TR-048 (ADSL Interoperability Test Plan) from DSL Forum. In this approach we have also used a HDSL (High Bit Rate DSL) and white noise disturbers on the line. The impulsive noises c1 and c2 (defined in G.996.1) are injected into the circuit at the CO (Central Office) end and CPE (Customer Premises Equipment) end of the loop simulator. Additionally, it was analyzed the spikes of noise's impact on the ADSL2+ line. In this case, pre-defined models of NEXT (Near-end crosstalk) and white noise are injected on CO and CPE side, simultaneously. Metrics like packet rate, lost packet count, bandwidth, short-term average transfer delay, and errored seconds are used to characterize the DSL loop under the noise impairments.
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| 17. |
- Zampolo, Ronaldo de Freitas, et al.
(författare)
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Mapping The Impulse Noise Spectral Features From Waveform Domain Onto Symbol Domain
- 2006
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Ingår i: 6th International Telecommunications Symposium. - 9788589748049 ; , s. 193-197
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Konferensbidrag (refereegranskat)abstract
- In this paper the spectral features of impulse noise in DSL systems are mapped from the waveform domain onto the symbol domain, considering a QAM receiver. This work can be viewed as part of a full symbol domain model for impulse noise, which should include the amplitude and spectral aspects. Since the available models of impulse noise in DSL are generally waveform-based, this kind of mapping is justified when symbol-based simulations are intended, in order to avoid computational overhead due to demodulating noise samples generated on waveform domain. The analytical development of such mapping is provided as well as some simulation results.
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