Pub Date : 2001-07-04DOI: 10.1109/EURCON.2001.938152
S. Zentner, L. Šumichrast, Z. Šipuš
Propagation of soliton-like pulses in dispersion managed nonlinear fibers has been numerically modeled and the properties of propagating pulses thoroughly investigated. A split step algorithm combining the finite differences beam propagation method with nonlinear phase modulation was used for modeling of the propagation equation. The propagation of pulses in a normal as well as in an anomalous average-dispersion regime has been investigated.
{"title":"Numerical simulation of nonlinear propagation in dispersion managed fibers","authors":"S. Zentner, L. Šumichrast, Z. Šipuš","doi":"10.1109/EURCON.2001.938152","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938152","url":null,"abstract":"Propagation of soliton-like pulses in dispersion managed nonlinear fibers has been numerically modeled and the properties of propagating pulses thoroughly investigated. A split step algorithm combining the finite differences beam propagation method with nonlinear phase modulation was used for modeling of the propagation equation. The propagation of pulses in a normal as well as in an anomalous average-dispersion regime has been investigated.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116750456","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 : 2001-07-04DOI: 10.1109/EURCON.2001.938179
N. Maloku, M. Frey-Pucko
Generation of test cases from a protocol specification for the purposes of testing both control and data flow aspects of a protocol implementation is a challenging problem. We propose an approach for protocols based on extended finite state machine (EFSM) models. Basically, we use the method of H. Ural and A. Williams (see Formal Description Techniques, vol.VI no.C-22, p.335-50, 1994). We extend the method to deal with more than one SDL process. The use of the improved method upgraded with simulation feasibility checking is illustrated by a practical example of test case generation for V5.2 startup procedure that involves the CTRL (control) and LNK (link) protocols with appropriate processes.
{"title":"SDL-based feasible test generation for communication protocols","authors":"N. Maloku, M. Frey-Pucko","doi":"10.1109/EURCON.2001.938179","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938179","url":null,"abstract":"Generation of test cases from a protocol specification for the purposes of testing both control and data flow aspects of a protocol implementation is a challenging problem. We propose an approach for protocols based on extended finite state machine (EFSM) models. Basically, we use the method of H. Ural and A. Williams (see Formal Description Techniques, vol.VI no.C-22, p.335-50, 1994). We extend the method to deal with more than one SDL process. The use of the improved method upgraded with simulation feasibility checking is illustrated by a practical example of test case generation for V5.2 startup procedure that involves the CTRL (control) and LNK (link) protocols with appropriate processes.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126615007","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 : 2001-07-04DOI: 10.1109/EURCON.2001.938133
D. Bajić, V. Šenk, M. Despotovic, D. Drajic
The frame-alignment monitoring schemes for STM-1 frames can be based upon the tests of synchronization word that is a subset of the complete framing signal. This paper deals with some particularities that can arise when implementing such a solution.
{"title":"Short STM-1 framing structures","authors":"D. Bajić, V. Šenk, M. Despotovic, D. Drajic","doi":"10.1109/EURCON.2001.938133","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938133","url":null,"abstract":"The frame-alignment monitoring schemes for STM-1 frames can be based upon the tests of synchronization word that is a subset of the complete framing signal. This paper deals with some particularities that can arise when implementing such a solution.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128477099","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 : 2001-07-04DOI: 10.1109/EURCON.2001.937783
J. Dospisil, T. Polgar
The importance of automated negotiation systems is increasing with the emergence of new technologies supporting faster reasoning engines and mobile code. One form of commerce that could benefit from automation is contracting. A broad variety of negotiation protocols has evolved in traditional markets. However, the primary focus of current research is on automation and the extension of these protocols. We argue that one fundamental question has been neglected: how to match the negotiation strategy and protocol to electronic markets. This paper briefly explores current concepts and directions in negotiation and collaboration strategies in multi agent systems. The paper concentrates on improving mobile constraint agents' ability to locate and utilize a suitable negotiation protocol. We present the service discovery framework which enables the agent to browse the network and locate a constraint solver with characteristics matching the scheduling problem at hand.
{"title":"Constraint agents can negotiate","authors":"J. Dospisil, T. Polgar","doi":"10.1109/EURCON.2001.937783","DOIUrl":"https://doi.org/10.1109/EURCON.2001.937783","url":null,"abstract":"The importance of automated negotiation systems is increasing with the emergence of new technologies supporting faster reasoning engines and mobile code. One form of commerce that could benefit from automation is contracting. A broad variety of negotiation protocols has evolved in traditional markets. However, the primary focus of current research is on automation and the extension of these protocols. We argue that one fundamental question has been neglected: how to match the negotiation strategy and protocol to electronic markets. This paper briefly explores current concepts and directions in negotiation and collaboration strategies in multi agent systems. The paper concentrates on improving mobile constraint agents' ability to locate and utilize a suitable negotiation protocol. We present the service discovery framework which enables the agent to browse the network and locate a constraint solver with characteristics matching the scheduling problem at hand.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130355130","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 : 2001-07-04DOI: 10.1109/EURCON.2001.938158
J. Cuchran, R. Róka
We first present a short overview of the characteristics of the access network's technologies and then focus on the comparison of metallic and optical access systems. In the final part, we place the emphasis on the presentation of the evolutionary deployment of optical access networks, concretely on the utilization of the FTTH/VDSL combination in the local access network.
{"title":"The evolution of the access network's infrastructure for the expansion of new broadband services and applications","authors":"J. Cuchran, R. Róka","doi":"10.1109/EURCON.2001.938158","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938158","url":null,"abstract":"We first present a short overview of the characteristics of the access network's technologies and then focus on the comparison of metallic and optical access systems. In the final part, we place the emphasis on the presentation of the evolutionary deployment of optical access networks, concretely on the utilization of the FTTH/VDSL combination in the local access network.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134161975","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 : 2001-07-04DOI: 10.1109/EURCON.2001.938156
J. Newbury
This paper considers the conditions for the transmission and reception of high-frequency data communications signals over the low-voltage distribution network. The driving force for exploiting this part of the power distribution network is examined, together with the types of services that potentially may be carried over the network. The type of problems encountered and potentially the limiting factors of providing such a service are examined. The standards being developed in the world to provide such services together with other associated organisations are considered. Recommendations for the future are also considered.
{"title":"Communications services using the low voltage power distribution network","authors":"J. Newbury","doi":"10.1109/EURCON.2001.938156","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938156","url":null,"abstract":"This paper considers the conditions for the transmission and reception of high-frequency data communications signals over the low-voltage distribution network. The driving force for exploiting this part of the power distribution network is examined, together with the types of services that potentially may be carried over the network. The type of problems encountered and potentially the limiting factors of providing such a service are examined. The standards being developed in the world to provide such services together with other associated organisations are considered. Recommendations for the future are also considered.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134165569","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 : 2001-07-04DOI: 10.1109/EURCON.2001.937750
M. Munster, L. Hanzo
OFDM transmission is known to be sensitive against carrier frequency offsets, as well as against the channel impulse response (CIR) variations incurred during an OFDM symbol period. Both of these phenomena lead to inter-subcarrier interference (ICI). Here, we concentrate on the latter phenomenon. ICI can be considered as an additional noise contribution, which linearly depends on the signal power, and thus it potentially limits the achievable BER at relatively high SNRs. In this contribution, we propose a second-order time-domain CIR tap variation estimator, which relies on both the received signal as well as on tentative symbol decisions. Our simulation results, obtained in the context of a system employing decision-directed channel-prediction, demonstrate that, with the aid of the proposed algorithm, ICI cancellation can be performed even in high Doppler frequency channel scenarios. This is achieved without inserting additional time-domain pilot symbols.
{"title":"Second-order channel parameter estimation assisted cancellation of channel variation-induced inter-subcarrier interference in OFDM systems","authors":"M. Munster, L. Hanzo","doi":"10.1109/EURCON.2001.937750","DOIUrl":"https://doi.org/10.1109/EURCON.2001.937750","url":null,"abstract":"OFDM transmission is known to be sensitive against carrier frequency offsets, as well as against the channel impulse response (CIR) variations incurred during an OFDM symbol period. Both of these phenomena lead to inter-subcarrier interference (ICI). Here, we concentrate on the latter phenomenon. ICI can be considered as an additional noise contribution, which linearly depends on the signal power, and thus it potentially limits the achievable BER at relatively high SNRs. In this contribution, we propose a second-order time-domain CIR tap variation estimator, which relies on both the received signal as well as on tentative symbol decisions. Our simulation results, obtained in the context of a system employing decision-directed channel-prediction, demonstrate that, with the aid of the proposed algorithm, ICI cancellation can be performed even in high Doppler frequency channel scenarios. This is achieved without inserting additional time-domain pilot symbols.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"217 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124572671","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 : 2001-07-04DOI: 10.1109/EURCON.2001.938142
M. Dadić
Ghosts are time delayed, attenuated and distorted versions of the intended television signal. This paper treats the influence of the channel transfer function on performance of an adaptive inverse modeling method, namely the least mean squares (LMS) algorithm. The zeros in the channel transfer function correspond to poles in the inverse model. With these poles inside or outside the unit circle on the z-plane, accurate enough modeling can be achieved with left-handed and right-handed sequences, using finite impulse response (FIR) filters, large enough and modeling delay. For non-repeated poles, the level of residual ghosts is greater, but line-by-line processing can make them smaller and their level decreases when the number of taps is increased. Repeated poles cause the largest magnitudes of residual ghosts, and they cannot be suppressed more than a level even with an increased number of taps.
{"title":"Influence of channel transfer function on LMS algorithm based nonrecursive deghosting in analog TV","authors":"M. Dadić","doi":"10.1109/EURCON.2001.938142","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938142","url":null,"abstract":"Ghosts are time delayed, attenuated and distorted versions of the intended television signal. This paper treats the influence of the channel transfer function on performance of an adaptive inverse modeling method, namely the least mean squares (LMS) algorithm. The zeros in the channel transfer function correspond to poles in the inverse model. With these poles inside or outside the unit circle on the z-plane, accurate enough modeling can be achieved with left-handed and right-handed sequences, using finite impulse response (FIR) filters, large enough and modeling delay. For non-repeated poles, the level of residual ghosts is greater, but line-by-line processing can make them smaller and their level decreases when the number of taps is increased. Repeated poles cause the largest magnitudes of residual ghosts, and they cannot be suppressed more than a level even with an increased number of taps.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124552817","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 : 2001-07-04DOI: 10.1109/EURCON.2001.937775
M. Verderber, A. Zemva, A. Trost
We demonstrate the feasibility of exploiting FPGA devices for implementation of a computing-intensive algorithm for edge detection which is one of the earliest steps in image processing. We have developed a modular FPGA-based prototyping system composed of five Xilinx Spartan FPGA devices. The purpose of the system is to evaluate various image processing algorithms implemented in hardware. We have already implemented the edge detection algorithm on the basis of the inverse discrete Fourier transform (IDFT). We have first performed a discrete Fourier transform (DFT) on the input images, multiplying the samples with high-pass filter followed by the IDFT to obtain the image with detected edges. The whole algorithm is performed in a real-time. We have compared the efficiency of the algorithm versus the software implementation on the PC.
{"title":"Implementation of IDFT algorithm","authors":"M. Verderber, A. Zemva, A. Trost","doi":"10.1109/EURCON.2001.937775","DOIUrl":"https://doi.org/10.1109/EURCON.2001.937775","url":null,"abstract":"We demonstrate the feasibility of exploiting FPGA devices for implementation of a computing-intensive algorithm for edge detection which is one of the earliest steps in image processing. We have developed a modular FPGA-based prototyping system composed of five Xilinx Spartan FPGA devices. The purpose of the system is to evaluate various image processing algorithms implemented in hardware. We have already implemented the edge detection algorithm on the basis of the inverse discrete Fourier transform (IDFT). We have first performed a discrete Fourier transform (DFT) on the input images, multiplying the samples with high-pass filter followed by the IDFT to obtain the image with detected edges. The whole algorithm is performed in a real-time. We have compared the efficiency of the algorithm versus the software implementation on the PC.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114768512","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 : 2001-07-04DOI: 10.1109/EURCON.2001.937758
L. Hebbes, R. Malyan, P. Ball
Turbo codes are computationally intensive, but outperform many other channel coding schemes. This paper addresses the computational requirements of turbo codes and how these affect the performance of the coding scheme. Some pointers are given as to how to design codes that both perform well and have a reduced delay. Selection between codes with the same delay can be made based on performance. A formula is also presented that allows the prediction of the delay based on the computational complexities of a particular turbo code.
{"title":"Computational complexities and the relative performance of turbo codes","authors":"L. Hebbes, R. Malyan, P. Ball","doi":"10.1109/EURCON.2001.937758","DOIUrl":"https://doi.org/10.1109/EURCON.2001.937758","url":null,"abstract":"Turbo codes are computationally intensive, but outperform many other channel coding schemes. This paper addresses the computational requirements of turbo codes and how these affect the performance of the coding scheme. Some pointers are given as to how to design codes that both perform well and have a reduced delay. Selection between codes with the same delay can be made based on performance. A formula is also presented that allows the prediction of the delay based on the computational complexities of a particular turbo code.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117313199","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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