Pub Date : 1991-12-02DOI: 10.1109/GLOCOM.1991.188683
T. Moore, W. Krzymień
Statistical results are presented for DS3 signals crossing cascaded chains of SONET island networks, based on a computer-aided waiting time jitter accumulation model. The parameters of a phase-spreading desynchronizer circuit, necessary to control the additional jitter caused by pointer adjustments, are characterized in terms of jitter accumulation performance. Simulation results and analysis for both nondegraded and degraded network synchronization modes are given, including the effect of pointer adjustments. With special consideration given to certain phase spreading desynchronizer design parameters, the jitter accumulation characteristics for DS3 signals in SONET are well behaved for the example SONET study network.<>
{"title":"A simulation study of DS3 waiting time jitter accumulation in SONET","authors":"T. Moore, W. Krzymień","doi":"10.1109/GLOCOM.1991.188683","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188683","url":null,"abstract":"Statistical results are presented for DS3 signals crossing cascaded chains of SONET island networks, based on a computer-aided waiting time jitter accumulation model. The parameters of a phase-spreading desynchronizer circuit, necessary to control the additional jitter caused by pointer adjustments, are characterized in terms of jitter accumulation performance. Simulation results and analysis for both nondegraded and degraded network synchronization modes are given, including the effect of pointer adjustments. With special consideration given to certain phase spreading desynchronizer design parameters, the jitter accumulation characteristics for DS3 signals in SONET are well behaved for the example SONET study network.<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130181607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1991-12-02DOI: 10.1109/GLOCOM.1991.188435
A. Ganz, B. Li
The authors present a performance study of a satellite cluster consisting of m satellites interconnected through intersatellite links (ISLs). In each satellite, the uplinks are operated under the slotted ALOHA policy, while the downlinks and intersatellite links are operated employing the TDM (time division multiplexing) policy. The packets successfully arriving at the satellite from the earth zones and from the ISLs are stored onboard the satellite. The satellite cluster performance is expressed in terms of throughput. The performance measure is obtained as a function of the system load and traffic distribution, and of the system configuration in terms of the number of uplinks, number of downlinks, number of buffers, number of transponders, and the ISL capacity. As an exact Markov modeling of the above system leads to intractable solutions, a tractable approximate analysis is introduced. The introduced analysis can be used to investigate the sensitivity of the system performance as a function of the system configuration.<>
{"title":"Design and analysis of satellite clusters","authors":"A. Ganz, B. Li","doi":"10.1109/GLOCOM.1991.188435","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188435","url":null,"abstract":"The authors present a performance study of a satellite cluster consisting of m satellites interconnected through intersatellite links (ISLs). In each satellite, the uplinks are operated under the slotted ALOHA policy, while the downlinks and intersatellite links are operated employing the TDM (time division multiplexing) policy. The packets successfully arriving at the satellite from the earth zones and from the ISLs are stored onboard the satellite. The satellite cluster performance is expressed in terms of throughput. The performance measure is obtained as a function of the system load and traffic distribution, and of the system configuration in terms of the number of uplinks, number of downlinks, number of buffers, number of transponders, and the ISL capacity. As an exact Markov modeling of the above system leads to intractable solutions, a tractable approximate analysis is introduced. The introduced analysis can be used to investigate the sensitivity of the system performance as a function of the system configuration.<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129280073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1991-12-02DOI: 10.1109/GLOCOM.1991.188433
H. A. Henriques, F. Abbas, M. Nakhla
The authors present results of laboratory measurements of the power spectral density of various types of satellite television carriers modulated with live video in a way that can be readily utilized by satellite network operators wishing to protect their narrowband digital carriers according to CCIR Recommendation 523. From these results, it can be seen that, although for television carriers modulated with energy dispersal signal alone a large improvement in the interference situation can be obtained by replacing frame rate energy dispersal with other types of waveforms, the modulation of the carrier with live video will limit the benefit of the improvement since it will now represent the worst case. For this reason, a special operational procedure for the transmission of television carriers is suggested which could improve the interference situation without the need to replace the frame rate energy dispersal signal.<>
{"title":"Interference from television carriers into narrowband digital carriers","authors":"H. A. Henriques, F. Abbas, M. Nakhla","doi":"10.1109/GLOCOM.1991.188433","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188433","url":null,"abstract":"The authors present results of laboratory measurements of the power spectral density of various types of satellite television carriers modulated with live video in a way that can be readily utilized by satellite network operators wishing to protect their narrowband digital carriers according to CCIR Recommendation 523. From these results, it can be seen that, although for television carriers modulated with energy dispersal signal alone a large improvement in the interference situation can be obtained by replacing frame rate energy dispersal with other types of waveforms, the modulation of the carrier with live video will limit the benefit of the improvement since it will now represent the worst case. For this reason, a special operational procedure for the transmission of television carriers is suggested which could improve the interference situation without the need to replace the frame rate energy dispersal signal.<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129592651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1991-12-02DOI: 10.1109/GLOCOM.1991.188445
K. Fukawa, H. Suzuki
The authors propose a novel adaptive equalization scheme which is a combination of the recursive least squares adaptive algorithm and maximum likelihood sequence estimation (RLS-MLSE). The performance of the scheme is demonstrated in frequency-selective fast fading mobile radio channels. RLS-MLSE employs a parallel estimation scheme in which the state of the channel is estimated by the Viterbi algorithm and the parameters of the channel impulse response are estimated by RLS. A simplified RLS algorithm and an extension to the diversity reception scheme are discussed. Computer simulations show that RLS-MLSE is suitable for 40-kb/s QPSK (quadrature phase shift keying) transmission in 900-MHz-band mobile radio systems, and that equalization with two-branch diversity operates up to a maximum Doppler frequency of 160 Hz.<>
{"title":"Adaptive equalization with RLS-MLSE for frequency-selective fast fading mobile radio channels","authors":"K. Fukawa, H. Suzuki","doi":"10.1109/GLOCOM.1991.188445","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188445","url":null,"abstract":"The authors propose a novel adaptive equalization scheme which is a combination of the recursive least squares adaptive algorithm and maximum likelihood sequence estimation (RLS-MLSE). The performance of the scheme is demonstrated in frequency-selective fast fading mobile radio channels. RLS-MLSE employs a parallel estimation scheme in which the state of the channel is estimated by the Viterbi algorithm and the parameters of the channel impulse response are estimated by RLS. A simplified RLS algorithm and an extension to the diversity reception scheme are discussed. Computer simulations show that RLS-MLSE is suitable for 40-kb/s QPSK (quadrature phase shift keying) transmission in 900-MHz-band mobile radio systems, and that equalization with two-branch diversity operates up to a maximum Doppler frequency of 160 Hz.<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"2017 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128039542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1991-12-02DOI: 10.1109/GLOCOM.1991.188395
F. Guillemin, J. Roberts
Cells arriving at an ATM (asynchronous transfer mode) network experience random delays due to queuing in upstream multiplexing stages. The alteration of the initial periodic nature of a constant bit rate cell stream due to such delays is the phenomenon of jitter. An assumption of Markovian dependence between the delays of successive cells makes it possible to calculate various quantities of interest for characterizing the jitter. This assumption is appropriate for two ATM multiplex models, and it was possible to investigate the effects of different source and multiplex parameters on the degree of jitter introduced. Jumping window and leaky bucket mechanisms have been dimensioned to enforce the peak rate of jittered streams. The leaky bucket is seen to be considerably more responsive than the jumping window. A synthetic characterization of jitter consists in the remote delay quantile divided by the period of the considered stream. This is sufficient to dimension the leaky bucket for one of the considered multiplex models and supports the heuristic approach of G. Niestegge (1990).<>
{"title":"Jitter and bandwidth enforcement","authors":"F. Guillemin, J. Roberts","doi":"10.1109/GLOCOM.1991.188395","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188395","url":null,"abstract":"Cells arriving at an ATM (asynchronous transfer mode) network experience random delays due to queuing in upstream multiplexing stages. The alteration of the initial periodic nature of a constant bit rate cell stream due to such delays is the phenomenon of jitter. An assumption of Markovian dependence between the delays of successive cells makes it possible to calculate various quantities of interest for characterizing the jitter. This assumption is appropriate for two ATM multiplex models, and it was possible to investigate the effects of different source and multiplex parameters on the degree of jitter introduced. Jumping window and leaky bucket mechanisms have been dimensioned to enforce the peak rate of jittered streams. The leaky bucket is seen to be considerably more responsive than the jumping window. A synthetic characterization of jitter consists in the remote delay quantile divided by the period of the considered stream. This is sufficient to dimension the leaky bucket for one of the considered multiplex models and supports the heuristic approach of G. Niestegge (1990).<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"364 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124575440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1991-12-02DOI: 10.1109/GLOCOM.1991.188437
J. Ventura-Traveset, L. Bella, H. Bessai, G. Hofmann
The implementation and test of a flexible digital multi-frequency time division multiple access (MF-TDMA) modulator are presented. The modulator is able to work at several frequencies (frequency hopping) on a burst basis without preambles or guardtimes. After a brief review of some satellite concepts (e.g., MF-TDMA, onboard processor, and traffic efficiency), direct-in-band modulation is introduced as the technique selected for the digital design of this frequency hopping modulator. A mixed Si/GaAs technology has been chosen for the hardware implementation and some tests are presented to show the good performance of the device.<>
{"title":"A flexible digital multicarrier modulator for multi-frequency TDMA satellite transmission","authors":"J. Ventura-Traveset, L. Bella, H. Bessai, G. Hofmann","doi":"10.1109/GLOCOM.1991.188437","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188437","url":null,"abstract":"The implementation and test of a flexible digital multi-frequency time division multiple access (MF-TDMA) modulator are presented. The modulator is able to work at several frequencies (frequency hopping) on a burst basis without preambles or guardtimes. After a brief review of some satellite concepts (e.g., MF-TDMA, onboard processor, and traffic efficiency), direct-in-band modulation is introduced as the technique selected for the digital design of this frequency hopping modulator. A mixed Si/GaAs technology has been chosen for the hardware implementation and some tests are presented to show the good performance of the device.<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124624150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1991-12-02DOI: 10.1109/GLOCOM.1991.188399
B. A. Makrucki
The author presents performance study results on forward congestion notification (FCN) in ATM (asynchronous transfer mode) networks; FCN is an element of an overall set of mechanisms that can be employed in ATM network traffic management. When a network element (e.g. a switch) becomes congested, it sets a notification indicator in chosen cell headers to inform destination terminals that there is congestion en-route. Terminal-to-terminal protocols may use this information to adapt their use of network resources to the prevailing conditions. The author investigates the efficacy of this scheme; in view of propagation delays that may affect the timeliness of the congestion information, it is not clear whether or not the mechanism would be useful in ATM networks. A simple terminal-to-terminal protocol that uses the FC indicator is described, and the behavior of network and terminal queues is investigated. It is found that FCN has significant value in helping terminal-to-terminal protocols adapt to the state of the network. Even when propagation delays are long, the use of the mechanism results in better behavior than if an open-loop mechanism is used.<>
{"title":"On the performance of submitting excess traffic to ATM networks","authors":"B. A. Makrucki","doi":"10.1109/GLOCOM.1991.188399","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188399","url":null,"abstract":"The author presents performance study results on forward congestion notification (FCN) in ATM (asynchronous transfer mode) networks; FCN is an element of an overall set of mechanisms that can be employed in ATM network traffic management. When a network element (e.g. a switch) becomes congested, it sets a notification indicator in chosen cell headers to inform destination terminals that there is congestion en-route. Terminal-to-terminal protocols may use this information to adapt their use of network resources to the prevailing conditions. The author investigates the efficacy of this scheme; in view of propagation delays that may affect the timeliness of the congestion information, it is not clear whether or not the mechanism would be useful in ATM networks. A simple terminal-to-terminal protocol that uses the FC indicator is described, and the behavior of network and terminal queues is investigated. It is found that FCN has significant value in helping terminal-to-terminal protocols adapt to the state of the network. Even when propagation delays are long, the use of the mechanism results in better behavior than if an open-loop mechanism is used.<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131320182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1991-12-02DOI: 10.1109/GLOCOM.1991.188354
D. Falconer, E. Arnon
Simple coordinated transmission schemes are proposed and analyzed, in which independent but identically PAM (pulse-amplitude-modulation) coded data are transmitted over two subscriber loop pairs in the presence of near-end crosstalk from other pairs' transmitters. A maximum-likelihood detection scheme utilizing noise variance and correlation between the two pairs is shown to yield significant improvement in performance, especially if there is an unbalance in the channel signal-to-noise ratios on the two pairs, or if there is significant noise correlation.<>
{"title":"Simple reception techniques for coordinated two-pair digital transmission","authors":"D. Falconer, E. Arnon","doi":"10.1109/GLOCOM.1991.188354","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188354","url":null,"abstract":"Simple coordinated transmission schemes are proposed and analyzed, in which independent but identically PAM (pulse-amplitude-modulation) coded data are transmitted over two subscriber loop pairs in the presence of near-end crosstalk from other pairs' transmitters. A maximum-likelihood detection scheme utilizing noise variance and correlation between the two pairs is shown to yield significant improvement in performance, especially if there is an unbalance in the channel signal-to-noise ratios on the two pairs, or if there is significant noise correlation.<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122917238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1991-12-02DOI: 10.1109/GLOCOM.1991.188442
A. Afrashteh, D. Chukurov
The authors present the performance of an experimental TDMA (time division multiple access) portable radio link with a switching single loop frequency synthesizer. The synthesizer, used as a local oscillator (LO), operates around 2 GHz with a 400 kHz step size and can switch over 20 MHz in less than 400 mu s. Performance of the TDMA radio link using WER (word error ratio) as a criterion was measured with the synthesizer switching frequencies between bursts at the transmitter. WER versus SNR (signal-to-noise ratio) shows small degradation, only 0.5 dB at WER of 10/sup -3/, due to the phase noise of the synthesizer signal. The phase noise values for an offset of 10 kHz and 100 kHz were -70 dBc/Hz and -90 dBc/Hz, respectively. Measurements indicated that the radio link performance showed only minor degradation when the synthesizer was switched 20 MHz only 400 mu s before transmitting a data burst. This permits a handset to switch to different channels than the channel of operation to measure signal quality for possible call-transfer once every 2 ms frame.<>
{"title":"Performance of a TDMA portable radio link with a switching frequency synthesizer","authors":"A. Afrashteh, D. Chukurov","doi":"10.1109/GLOCOM.1991.188442","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188442","url":null,"abstract":"The authors present the performance of an experimental TDMA (time division multiple access) portable radio link with a switching single loop frequency synthesizer. The synthesizer, used as a local oscillator (LO), operates around 2 GHz with a 400 kHz step size and can switch over 20 MHz in less than 400 mu s. Performance of the TDMA radio link using WER (word error ratio) as a criterion was measured with the synthesizer switching frequencies between bursts at the transmitter. WER versus SNR (signal-to-noise ratio) shows small degradation, only 0.5 dB at WER of 10/sup -3/, due to the phase noise of the synthesizer signal. The phase noise values for an offset of 10 kHz and 100 kHz were -70 dBc/Hz and -90 dBc/Hz, respectively. Measurements indicated that the radio link performance showed only minor degradation when the synthesizer was switched 20 MHz only 400 mu s before transmitting a data burst. This permits a handset to switch to different channels than the channel of operation to measure signal quality for possible call-transfer once every 2 ms frame.<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"40 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120988767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1991-12-02DOI: 10.1109/GLOCOM.1991.188438
A. Aghvami, O. Gemikonakli, S. Kato
The authors discuss the possibility of transmitting synchronous digital hierarchy (SDH) signals through two-link nonlinear satellite channels. Transmitting such high-bit-rate signals through standard 54-MHz transponder bandwidth requires the use of high-level modulation schemes. The techniques and technologies needed to make the use of 16-ary QAM (quadrature amplitude modulation) transmission feasible for future satellite communication systems are examined. It is shown that it is possible to transmit a synchronous-transport-module-level 1 (STM-1) signal through a standard 54-MHz transponder bandwidth using 16-ary QAM transmission, for the 6/4-GHz band. However, for higher frequency bands, due to high fade margins needed to achieve the high availability and performance for SDH systems, it is not practical to transmit the STM-1 signal through such standard transponder bandwidths.<>
{"title":"Transmission of SDH signals through future satellite channels using 16-ary QAM technique","authors":"A. Aghvami, O. Gemikonakli, S. Kato","doi":"10.1109/GLOCOM.1991.188438","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188438","url":null,"abstract":"The authors discuss the possibility of transmitting synchronous digital hierarchy (SDH) signals through two-link nonlinear satellite channels. Transmitting such high-bit-rate signals through standard 54-MHz transponder bandwidth requires the use of high-level modulation schemes. The techniques and technologies needed to make the use of 16-ary QAM (quadrature amplitude modulation) transmission feasible for future satellite communication systems are examined. It is shown that it is possible to transmit a synchronous-transport-module-level 1 (STM-1) signal through a standard 54-MHz transponder bandwidth using 16-ary QAM transmission, for the 6/4-GHz band. However, for higher frequency bands, due to high fade margins needed to achieve the high availability and performance for SDH systems, it is not practical to transmit the STM-1 signal through such standard transponder bandwidths.<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121083941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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