Pub Date : 2000-02-15DOI: 10.1109/IZSBC.2000.829240
G. Marias, L. Merakos
A distributed method for dynamic channel reservation in wireless ATM is presented. The proposed method applies to wireless ATM LAN, where base stations act as hubs to offer wireless ATM access to mobile units. In the proposed method, base stations are competing to access and reserve time on separate frequencies. Competition disciplines are introduced, and their performance is evaluated and compared through simulations.
{"title":"A distributed dynamic channel reservation framework for wireless ATM LANs","authors":"G. Marias, L. Merakos","doi":"10.1109/IZSBC.2000.829240","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829240","url":null,"abstract":"A distributed method for dynamic channel reservation in wireless ATM is presented. The proposed method applies to wireless ATM LAN, where base stations act as hubs to offer wireless ATM access to mobile units. In the proposed method, base stations are competing to access and reserve time on separate frequencies. Competition disciplines are introduced, and their performance is evaluated and compared through simulations.","PeriodicalId":409898,"journal":{"name":"2000 International Zurich Seminar on Broadband Communications. Accessing, Transmission, Networking. Proceedings (Cat. No.00TH8475)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129940221","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 : 2000-02-15DOI: 10.1109/IZSBC.2000.829243
T. Orfanoudakis, N. Leligou, J. Angelopoulos, E. Meciu, A. Harsanyi
The proliferation of HFC access systems enriching with digital bi-directional services the old analog cable TV plants, coupled with the emergence of the Internet as the dominant interactive application, make expedient the optimization of the access protocols for TCP/IP. The shared medium in the upstream and the buffer management policies in the cable modem need to implement mechanisms adapted to the bursty nature of traffic and the loss-oriented congestion avoidance mechanisms of TCP. Several packet discard policies are evaluated in conjunction with the MAC protocol, showing that significant throughput improvements can be achieved over the plain tail drop policy in the modem queue.
{"title":"Evaluation of IP oriented HFC access protocols","authors":"T. Orfanoudakis, N. Leligou, J. Angelopoulos, E. Meciu, A. Harsanyi","doi":"10.1109/IZSBC.2000.829243","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829243","url":null,"abstract":"The proliferation of HFC access systems enriching with digital bi-directional services the old analog cable TV plants, coupled with the emergence of the Internet as the dominant interactive application, make expedient the optimization of the access protocols for TCP/IP. The shared medium in the upstream and the buffer management policies in the cable modem need to implement mechanisms adapted to the bursty nature of traffic and the loss-oriented congestion avoidance mechanisms of TCP. Several packet discard policies are evaluated in conjunction with the MAC protocol, showing that significant throughput improvements can be achieved over the plain tail drop policy in the modem queue.","PeriodicalId":409898,"journal":{"name":"2000 International Zurich Seminar on Broadband Communications. Accessing, Transmission, Networking. Proceedings (Cat. No.00TH8475)","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134354864","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 : 2000-02-15DOI: 10.1109/IZSBC.2000.829246
R. Manivasakan, U. Desai, A. Karandikar
The correlated interarrival time process (CIPP) has been proposed in Manivasakan et al. (1999), for modeling both the composite arrival process of packets in broadband networks and the individual source modeling. The CIPP-a generalization of the Poisson process-is a stationary counting process and is parameterized by a correlation parameter "/spl rho/" which represents the degree of correlation in adjacent interarrivals in addition to "/spl lambda/" the intensity of the process. In this paper, we undertake the performance modeling of a more realistic finite buffered statistical multiplexer with smoothed VBR video traffic input using a CIPP/M/1/K queue. Queueing performance measures considered here are packet loss probability and conditional packet loss probability. The buffer occupancy distribution in a queue with real-world MPEG-1 VBR video traffic is compared with that of its "best fit" CIPP/M/1/K. The simulation results show that the correlation in interarrivals degrades the queueing performance in the finite capacity queue case also. Finally, we consider the fluid-flow approximation of queues with CIPP arrivals to study the behavior of a statistical multiplexer with VBR video traffic input. Comparisons with other models such as the Markov histogram model are also undertaken.
{"title":"The CIPP and the performance modeling of VBR video traffic by CIPP/M/1/K queue","authors":"R. Manivasakan, U. Desai, A. Karandikar","doi":"10.1109/IZSBC.2000.829246","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829246","url":null,"abstract":"The correlated interarrival time process (CIPP) has been proposed in Manivasakan et al. (1999), for modeling both the composite arrival process of packets in broadband networks and the individual source modeling. The CIPP-a generalization of the Poisson process-is a stationary counting process and is parameterized by a correlation parameter \"/spl rho/\" which represents the degree of correlation in adjacent interarrivals in addition to \"/spl lambda/\" the intensity of the process. In this paper, we undertake the performance modeling of a more realistic finite buffered statistical multiplexer with smoothed VBR video traffic input using a CIPP/M/1/K queue. Queueing performance measures considered here are packet loss probability and conditional packet loss probability. The buffer occupancy distribution in a queue with real-world MPEG-1 VBR video traffic is compared with that of its \"best fit\" CIPP/M/1/K. The simulation results show that the correlation in interarrivals degrades the queueing performance in the finite capacity queue case also. Finally, we consider the fluid-flow approximation of queues with CIPP arrivals to study the behavior of a statistical multiplexer with VBR video traffic input. Comparisons with other models such as the Markov histogram model are also undertaken.","PeriodicalId":409898,"journal":{"name":"2000 International Zurich Seminar on Broadband Communications. Accessing, Transmission, Networking. Proceedings (Cat. No.00TH8475)","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132218712","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 : 2000-02-15DOI: 10.1109/IZSBC.2000.829229
C. Ho
An efficient method for evaluating the average error probability of direct sequence spread-spectrum code-division multiple-access (CDMA) communication systems is presented. Various phase-shift keying systems are analyzed. Results of Gaussian approximation, saddlepoint approximation, and numerical contour integration by the saddlepoint method are compared. The variance and the error probability can be computed from the moment generating function of the receiver output. General and simple formulas for evaluating the multiple access interference variance are presented for systems using deterministic or random signature sequences. Both quadriphase-shift keying (QPSK) and offset quadriphase-shift keying (OQPSK) systems yield the same performance when the signal-to-noise ratio criterion is adopted. However, accurate numerical computations show that they do not have the same one. The results show that MSK yields better performance than QPSK and OQPSK.
{"title":"Calculation of error probability of CDMA communication systems using saddlepoint method","authors":"C. Ho","doi":"10.1109/IZSBC.2000.829229","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829229","url":null,"abstract":"An efficient method for evaluating the average error probability of direct sequence spread-spectrum code-division multiple-access (CDMA) communication systems is presented. Various phase-shift keying systems are analyzed. Results of Gaussian approximation, saddlepoint approximation, and numerical contour integration by the saddlepoint method are compared. The variance and the error probability can be computed from the moment generating function of the receiver output. General and simple formulas for evaluating the multiple access interference variance are presented for systems using deterministic or random signature sequences. Both quadriphase-shift keying (QPSK) and offset quadriphase-shift keying (OQPSK) systems yield the same performance when the signal-to-noise ratio criterion is adopted. However, accurate numerical computations show that they do not have the same one. The results show that MSK yields better performance than QPSK and OQPSK.","PeriodicalId":409898,"journal":{"name":"2000 International Zurich Seminar on Broadband Communications. Accessing, Transmission, Networking. Proceedings (Cat. No.00TH8475)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132358070","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 : 2000-02-15DOI: 10.1109/IZSBC.2000.829223
A. Hottinen, R. Wichman
The transmit diversity concept adopted for the FDD mode of the third generation WCDMA system in 3G standardization has an open-loop and a closed-loop mode. The open-loop mode applies space-time block coding and is provides full diversity for two transmit antennas. The closed-loop mode has two submodes, which both utilize downlink channel measurements and feedback signaling in controlling the phase and/or gain transmit weights in the two transmit antennas. In this paper we review the open- and closed-loop concepts and propose an enhancement to the feedback modes to further improve their performance. The enhanced feedback modes allow the base station to filter the feedback weights received from the terminal to improve beam resolution and system robustness.
{"title":"Transmit diversity using filtered feedback weights in the FDD/WCDMA system","authors":"A. Hottinen, R. Wichman","doi":"10.1109/IZSBC.2000.829223","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829223","url":null,"abstract":"The transmit diversity concept adopted for the FDD mode of the third generation WCDMA system in 3G standardization has an open-loop and a closed-loop mode. The open-loop mode applies space-time block coding and is provides full diversity for two transmit antennas. The closed-loop mode has two submodes, which both utilize downlink channel measurements and feedback signaling in controlling the phase and/or gain transmit weights in the two transmit antennas. In this paper we review the open- and closed-loop concepts and propose an enhancement to the feedback modes to further improve their performance. The enhanced feedback modes allow the base station to filter the feedback weights received from the terminal to improve beam resolution and system robustness.","PeriodicalId":409898,"journal":{"name":"2000 International Zurich Seminar on Broadband Communications. Accessing, Transmission, Networking. Proceedings (Cat. No.00TH8475)","volume":"2016 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134500115","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 : 2000-02-15DOI: 10.1109/IZSBC.2000.829236
M. Otte, M. Bucker, J. Gotze
In this paper we investigate the use of CORDIC-like approximate rotations for complex valued signal processing applications. In particular we design a processor array for minimum variance distortionless response (MVDR) beamforming with multiple constraints entirely based on linear and circular complex transformations. The required transformations are expressed as factorized transformations such that they can be represented as sets of real CORDIC-like modules.
{"title":"Complex CORDIC-like algorithms for linearly constrained MVDR beamforming","authors":"M. Otte, M. Bucker, J. Gotze","doi":"10.1109/IZSBC.2000.829236","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829236","url":null,"abstract":"In this paper we investigate the use of CORDIC-like approximate rotations for complex valued signal processing applications. In particular we design a processor array for minimum variance distortionless response (MVDR) beamforming with multiple constraints entirely based on linear and circular complex transformations. The required transformations are expressed as factorized transformations such that they can be represented as sets of real CORDIC-like modules.","PeriodicalId":409898,"journal":{"name":"2000 International Zurich Seminar on Broadband Communications. Accessing, Transmission, Networking. Proceedings (Cat. No.00TH8475)","volume":"145 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133276869","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 : 2000-02-15DOI: 10.1109/IZSBC.2000.829238
M. Decina
Summary form only given. In recent years, the telecommunications industry has converged on the key role of the Internet protocol (IP), for the definition of the infrastructure for new multimedia and advanced communications applications. As the demand for packet-based data traffic grows exponentially, it will overtake traditional circuit-switched voice on the communications networks throughout the world and eventually become the predominant way of providing telecommunications by the next decade. Market analysts predict the voice/data traffic crossover to occur in the next few years, driven in particular by exploding demand for IP-based applications, both on the public Internet and on private intranets and extranets.
{"title":"Service and technology trends in the next decade","authors":"M. Decina","doi":"10.1109/IZSBC.2000.829238","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829238","url":null,"abstract":"Summary form only given. In recent years, the telecommunications industry has converged on the key role of the Internet protocol (IP), for the definition of the infrastructure for new multimedia and advanced communications applications. As the demand for packet-based data traffic grows exponentially, it will overtake traditional circuit-switched voice on the communications networks throughout the world and eventually become the predominant way of providing telecommunications by the next decade. Market analysts predict the voice/data traffic crossover to occur in the next few years, driven in particular by exploding demand for IP-based applications, both on the public Internet and on private intranets and extranets.","PeriodicalId":409898,"journal":{"name":"2000 International Zurich Seminar on Broadband Communications. Accessing, Transmission, Networking. Proceedings (Cat. No.00TH8475)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126467561","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 : 2000-02-15DOI: 10.1109/IZSBC.2000.829255
H. Masui, M. Ishii, S. Takahashi, H. Shimizu, T. Kobayashi
This paper discusses microwave path-loss characteristics as a function of mobile antenna height in an urban line-of-sight environment. Comparing daytime and midnight measurements, we reveal that the break points shift to the near side because of the existence of effective heights of the road and the sidewalk.
{"title":"Difference of break-point characteristics due to mobile antenna heights in microwave urban LOS propagation","authors":"H. Masui, M. Ishii, S. Takahashi, H. Shimizu, T. Kobayashi","doi":"10.1109/IZSBC.2000.829255","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829255","url":null,"abstract":"This paper discusses microwave path-loss characteristics as a function of mobile antenna height in an urban line-of-sight environment. Comparing daytime and midnight measurements, we reveal that the break points shift to the near side because of the existence of effective heights of the road and the sidewalk.","PeriodicalId":409898,"journal":{"name":"2000 International Zurich Seminar on Broadband Communications. Accessing, Transmission, Networking. Proceedings (Cat. No.00TH8475)","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123800104","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 : 2000-02-15DOI: 10.1109/IZSBC.2000.829261
R. Peterson, R. Ziemer, J. L. Seoane
A modulation scheme is proposed for high-information-rate high-reliability personal communications where controlled peak-to-average transmit power ratio is an issue. The scheme is a hybrid of classical biorthogonal modulation and code division multiple access multicode modulation. Analytical and simulation results are presented for static AWGN channels and simulation results are presented for flat fading channels.
{"title":"Biorthogonal multicode modulation for high-rate high-reliability personal communications requiring controlled peak-to-average transmit power ratio","authors":"R. Peterson, R. Ziemer, J. L. Seoane","doi":"10.1109/IZSBC.2000.829261","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829261","url":null,"abstract":"A modulation scheme is proposed for high-information-rate high-reliability personal communications where controlled peak-to-average transmit power ratio is an issue. The scheme is a hybrid of classical biorthogonal modulation and code division multiple access multicode modulation. Analytical and simulation results are presented for static AWGN channels and simulation results are presented for flat fading channels.","PeriodicalId":409898,"journal":{"name":"2000 International Zurich Seminar on Broadband Communications. Accessing, Transmission, Networking. Proceedings (Cat. No.00TH8475)","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124634742","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 : 2000-02-15DOI: 10.1109/IZSBC.2000.829228
P. Tan, L. Rasmussen, Teng Joon Lim
The detection strategy usually denoted optimal multiuser detection is equivalent to the solution of a (0,1)-constrained maximum-likelihood (ML) problem, a problem which is known to be NP-complete. In contrast, the unconstrained ML problem can be solved quite easily and is known as the decorrelating detector. In this paper, we consider the box-constrained ML problem and suggest a general iterative solution algorithm. Special cases of this algorithm correspond to known, nonlinear successive and parallel interference cancellation structures, using a clipped soft decision function for making tentative decisions. These structures are therefore maximum-likelihood under the assumption that the detected data vector is constrained to lie within a hypercube. Convergence issues are investigated and an efficient implementation is suggested. The BER performance is studied via computer simulations and the expected performance improvements over unconstrained ML is verified.
{"title":"Box-constrained maximum-likelihood detection in CDMA","authors":"P. Tan, L. Rasmussen, Teng Joon Lim","doi":"10.1109/IZSBC.2000.829228","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829228","url":null,"abstract":"The detection strategy usually denoted optimal multiuser detection is equivalent to the solution of a (0,1)-constrained maximum-likelihood (ML) problem, a problem which is known to be NP-complete. In contrast, the unconstrained ML problem can be solved quite easily and is known as the decorrelating detector. In this paper, we consider the box-constrained ML problem and suggest a general iterative solution algorithm. Special cases of this algorithm correspond to known, nonlinear successive and parallel interference cancellation structures, using a clipped soft decision function for making tentative decisions. These structures are therefore maximum-likelihood under the assumption that the detected data vector is constrained to lie within a hypercube. Convergence issues are investigated and an efficient implementation is suggested. The BER performance is studied via computer simulations and the expected performance improvements over unconstrained ML is verified.","PeriodicalId":409898,"journal":{"name":"2000 International Zurich Seminar on Broadband Communications. Accessing, Transmission, Networking. Proceedings (Cat. No.00TH8475)","volume":"191 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126041678","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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