Pub Date : 1991-12-02DOI: 10.1109/GLOCOM.1991.188416
V. Jain, A.B. Asgill, P. Bobrek
The authors present a purely digital timing recovery scheme for optical OOK receivers, which offers the advantages of low hardware complexity and low jitter. In this technique, the computation of the timing function is based on symbol-rate samples of the received signal. A gain scheduling strategy is used for the timing updates; a short training set of symbols accompanied by large gain for the timing updates is followed by data symbols and low gain for the timing updates. This allows the use of large correction step sizes during training, leading to fast convergence. It is particularly suitable for an all digital optical system.<>
{"title":"Synchronization technique for optical OOK receivers","authors":"V. Jain, A.B. Asgill, P. Bobrek","doi":"10.1109/GLOCOM.1991.188416","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188416","url":null,"abstract":"The authors present a purely digital timing recovery scheme for optical OOK receivers, which offers the advantages of low hardware complexity and low jitter. In this technique, the computation of the timing function is based on symbol-rate samples of the received signal. A gain scheduling strategy is used for the timing updates; a short training set of symbols accompanied by large gain for the timing updates is followed by data symbols and low gain for the timing updates. This allows the use of large correction step sizes during training, leading to fast convergence. It is particularly suitable for an all digital optical system.<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"25 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":"123423398","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.1991.188461
P. Johnson
The author examines the recent efforts of the ANSI T1M1.5 working group and T1M1 committee to apply object-oriented (O-O) data modeling techniques to the development of standards for the operation, administration, maintenance, and provisioning (OAM&P) of telecommunications networks (TNs). The use of these state-of-the-art data modeling techniques is launching the North American telecommunications network into an open, standard, multi-vendor communications environment. The author presents a description of the organization of the T1M1 standards body, a brief overview of the Telecommunications Management Network (TMN) model, the basic principles of O-O data modeling, a description of recent network management standardization efforts in T1M1 that use these techniques, and a brief description of current T1M1 work.<>
{"title":"Application of object-oriented techniques to the OAM&P of telecommunications networks","authors":"P. Johnson","doi":"10.1109/GLOCOM.1991.188461","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188461","url":null,"abstract":"The author examines the recent efforts of the ANSI T1M1.5 working group and T1M1 committee to apply object-oriented (O-O) data modeling techniques to the development of standards for the operation, administration, maintenance, and provisioning (OAM&P) of telecommunications networks (TNs). The use of these state-of-the-art data modeling techniques is launching the North American telecommunications network into an open, standard, multi-vendor communications environment. The author presents a description of the organization of the T1M1 standards body, a brief overview of the Telecommunications Management Network (TMN) model, the basic principles of O-O data modeling, a description of recent network management standardization efforts in T1M1 that use these techniques, and a brief description of current T1M1 work.<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"42 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":"124489863","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.1991.188349
D. Heyman, A. Tabatabai, T. V. Lakshman
Some of the source modeling and performance issues related to providing video teleconference services over asynchronous transfer mode (ATM) networks were studied. Under certain circumstances, traffic periodicity (due to the constant video frame rate) can cause different sources with identical statistical characteristics to experience cell-loss rates which can differ by several orders of magnitude. Some of this source-periodicity effect can be mitigated by appropriate buffer scheduling. For the video teleconference sequence analyzed (without scene changes or scene cuts and with moderate motion), the number of cells per frame is not normally distributed. Instead, it follows a gamma (or negative binomial) distribution. For traffic studies, an autoregressive model of order 2 and a two-state Markov chain model either underestimate or overestimate the occurrence of frames with a large number of cells, and these frames are a primary factor in determining cell-loss rates. The order-2 autoregressive model, however, fits the data well in a statistical sense. A multistate Markov chain model which can be derived from three traffic parameters (mean, correlation, and variance) is sufficiently accurate for use in traffic studies.<>
{"title":"Statistical analysis and simulation study of video teleconference traffic in ATM networks","authors":"D. Heyman, A. Tabatabai, T. V. Lakshman","doi":"10.1109/GLOCOM.1991.188349","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188349","url":null,"abstract":"Some of the source modeling and performance issues related to providing video teleconference services over asynchronous transfer mode (ATM) networks were studied. Under certain circumstances, traffic periodicity (due to the constant video frame rate) can cause different sources with identical statistical characteristics to experience cell-loss rates which can differ by several orders of magnitude. Some of this source-periodicity effect can be mitigated by appropriate buffer scheduling. For the video teleconference sequence analyzed (without scene changes or scene cuts and with moderate motion), the number of cells per frame is not normally distributed. Instead, it follows a gamma (or negative binomial) distribution. For traffic studies, an autoregressive model of order 2 and a two-state Markov chain model either underestimate or overestimate the occurrence of frames with a large number of cells, and these frames are a primary factor in determining cell-loss rates. The order-2 autoregressive model, however, fits the data well in a statistical sense. A multistate Markov chain model which can be derived from three traffic parameters (mean, correlation, and variance) is sufficiently accurate for use in traffic studies.<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"93 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":"124653400","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.1991.188364
T. Fischer
It is shown that, for the subband coding of a wide sense stationary Gaussian source, with the implied separate encoding of the subband signals, the encoding performance is generally inferior to the rate-distortion function of the source. Exceptions are when the source is white or when the filters are ideal (brickwall).<>
{"title":"On the rate-distortion efficiency of subband coding","authors":"T. Fischer","doi":"10.1109/GLOCOM.1991.188364","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188364","url":null,"abstract":"It is shown that, for the subband coding of a wide sense stationary Gaussian source, with the implied separate encoding of the subband signals, the encoding performance is generally inferior to the rate-distortion function of the source. Exceptions are when the source is white or when the filters are ideal (brickwall).<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"41 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":"124812643","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.1991.188355
J. Cioffi, J. Bingham
A data-driven echo canceller for full-duplex data transmission with multitone modulation is presented. This echo canceller is shown not to be impaired by the eigenvalue-spread problems that are inherent in signal-driven echo cancellers, and to have numerical performance and cancellation range that equals, and in most cases exceeds, that of data-driven echo cancellers used in data transmission with baseband or quadrature amplitude modulation. The method makes use of frequency-domain updating, but with time-domain implementation of the canceller. It introduces no delay into the received signal path.<>
{"title":"A data-driven multitone echo canceller","authors":"J. Cioffi, J. Bingham","doi":"10.1109/GLOCOM.1991.188355","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188355","url":null,"abstract":"A data-driven echo canceller for full-duplex data transmission with multitone modulation is presented. This echo canceller is shown not to be impaired by the eigenvalue-spread problems that are inherent in signal-driven echo cancellers, and to have numerical performance and cancellation range that equals, and in most cases exceeds, that of data-driven echo cancellers used in data transmission with baseband or quadrature amplitude modulation. The method makes use of frequency-domain updating, but with time-domain implementation of the canceller. It introduces no delay into the received signal path.<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"41 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":"124812684","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.1991.188686
M. Akamine, K. Miseki, M. Oshikiri
The authors describe improvements in the ADP-CELP (adaptive-density-pulse code-excited-linear-prediction) coder at 4 kb/s. A fractional delay was introduced to the adaptive codebook. A fast exhaustive search procedure for a uniformly distributed fractional delay was studied for the case where the delay length is shorter than the codevector's dimension. A novel method to determine the long-term predictor's gain was also used. Four methods to find the density pattern of the ADP excitation were investigated. A modified adaptive postfilter was used to improve subjective speech quality.<>
{"title":"Improvement of ADP-CELP speech coding at 4 kbits/s","authors":"M. Akamine, K. Miseki, M. Oshikiri","doi":"10.1109/GLOCOM.1991.188686","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188686","url":null,"abstract":"The authors describe improvements in the ADP-CELP (adaptive-density-pulse code-excited-linear-prediction) coder at 4 kb/s. A fractional delay was introduced to the adaptive codebook. A fast exhaustive search procedure for a uniformly distributed fractional delay was studied for the case where the delay length is shorter than the codevector's dimension. A novel method to determine the long-term predictor's gain was also used. Four methods to find the density pattern of the ADP excitation were investigated. A modified adaptive postfilter was used to improve subjective speech quality.<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"55 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113973825","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.1991.188431
B. Steyaert, H. Bruneel
A statistical multiplexer with a finite number of independent and identical bursty traffic sources (users) is considered. The burstiness of the sources is modeled by describing both the active periods (during which a user generates one packet per slot) and the passive periods (during which a user does not generate any data) as geometric random variables. As a result, a correlated-arrivals queuing model for the multiplexer buffer is obtained, and it is analyzed by numerical means. Specifically, algorithms are given for the explicit derivation of the probability mass functions of the buffer contents (in packets) and the packet delay (in slots). The results indicate a very strong influence of the burstiness of the required buffer space in the multiplexer and the possible values of the packet delay, even for a given mean arrival rate per slot.<>
{"title":"An effective algorithm to calculate the distribution of the buffer contents and the packet delay in a multiplexer with bursty sources","authors":"B. Steyaert, H. Bruneel","doi":"10.1109/GLOCOM.1991.188431","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188431","url":null,"abstract":"A statistical multiplexer with a finite number of independent and identical bursty traffic sources (users) is considered. The burstiness of the sources is modeled by describing both the active periods (during which a user generates one packet per slot) and the passive periods (during which a user does not generate any data) as geometric random variables. As a result, a correlated-arrivals queuing model for the multiplexer buffer is obtained, and it is analyzed by numerical means. Specifically, algorithms are given for the explicit derivation of the probability mass functions of the buffer contents (in packets) and the packet delay (in slots). The results indicate a very strong influence of the burstiness of the required buffer space in the multiplexer and the possible values of the packet delay, even for a given mean arrival rate per slot.<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"28 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":"122681401","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.1991.188622
O. Baireuther, R. Vinckier
It is argued that within the framework of the RACE (Research and Development in Advanced Communications in Europe) program, demonstrators and integration activities are essential contributions. They validate the work carried out in areas like strategies and technology and support application pilots. Their validity is applicable for all the elements of telecommunication networks, such as terminals, transmission, switching, network management and administration contained under the program. Various levels of the applied demonstrations are outlined and two integration projects are briefly noted.<>
{"title":"Demonstrators and integration","authors":"O. Baireuther, R. Vinckier","doi":"10.1109/GLOCOM.1991.188622","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188622","url":null,"abstract":"It is argued that within the framework of the RACE (Research and Development in Advanced Communications in Europe) program, demonstrators and integration activities are essential contributions. They validate the work carried out in areas like strategies and technology and support application pilots. Their validity is applicable for all the elements of telecommunication networks, such as terminals, transmission, switching, network management and administration contained under the program. Various levels of the applied demonstrations are outlined and two integration projects are briefly noted.<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"29 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":"125149101","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.1991.188724
Michael J Forbes, S. P. Spencer
The authors highlight many of the open challenges to fulfilment of the technical specification for TR-303. The telephone operating companies have a vision of integrated access that focuses on increased revenues at a reduced cost in a timely fashion. TR-303 is a technical solution that begins to address many of the issues embodied in this vision. While there are many technical challenges, the key to the timely introduction of TR-303 technology is compatibility with the existing investment in operations systems (OSs), local digital switches (LDSs) and digital loop carrier systems. TR-303 will begin with a core feature set that will be proven in close interaction between the LDS and the remote digital terminal. The existence of working TR-303 systems in the network, working with existing OSs, will provide a springboard for new OS functionality as well as providing a stable interface for development.<>
{"title":"Integrated access: the achievement of a vision","authors":"Michael J Forbes, S. P. Spencer","doi":"10.1109/GLOCOM.1991.188724","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188724","url":null,"abstract":"The authors highlight many of the open challenges to fulfilment of the technical specification for TR-303. The telephone operating companies have a vision of integrated access that focuses on increased revenues at a reduced cost in a timely fashion. TR-303 is a technical solution that begins to address many of the issues embodied in this vision. While there are many technical challenges, the key to the timely introduction of TR-303 technology is compatibility with the existing investment in operations systems (OSs), local digital switches (LDSs) and digital loop carrier systems. TR-303 will begin with a core feature set that will be proven in close interaction between the LDS and the remote digital terminal. The existence of working TR-303 systems in the network, working with existing OSs, will provide a springboard for new OS functionality as well as providing a stable interface for development.<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"6 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":"125345468","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.1991.188478
G. Gordos
For pitch detection, voiced/unvoiced decisions and speech/nonspeech decisions, an improved average magnitude difference function (AMDF) is described that has given promising results: adaptation improves accuracy and skeletonization speeds up computation. A novel definition of time-warped distance results in decreased error probability in speech recognition; however, no fast algorithm for its computation has yet been found. The concept of time-warped average, on the other hand, is easy to compute and results in better speech recognition score. Both improved AMDF and time-warped distance are discussed for use in the speaker identification environment.<>
{"title":"New feature extraction methods and the concept of time-warped distance in speech processing","authors":"G. Gordos","doi":"10.1109/GLOCOM.1991.188478","DOIUrl":"https://doi.org/10.1109/GLOCOM.1991.188478","url":null,"abstract":"For pitch detection, voiced/unvoiced decisions and speech/nonspeech decisions, an improved average magnitude difference function (AMDF) is described that has given promising results: adaptation improves accuracy and skeletonization speeds up computation. A novel definition of time-warped distance results in decreased error probability in speech recognition; however, no fast algorithm for its computation has yet been found. The concept of time-warped average, on the other hand, is easy to compute and results in better speech recognition score. Both improved AMDF and time-warped distance are discussed for use in the speaker identification environment.<<ETX>>","PeriodicalId":343080,"journal":{"name":"IEEE Global Telecommunications Conference GLOBECOM '91: Countdown to the New Millennium. Conference Record","volume":"19 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":"129940149","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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