Pub Date : 2000-02-15DOI: 10.1109/IZSBC.2000.829245
O. Kunert
Field buses have been developed to fulfil real-time requirements of applications related to factory automation. However, they can only cover geographical areas such as factory halls or buildings which causes the occurrence of many small segments in larger environments unable to communicate among each other. In order to reduce this drawback a possible solution is to connect those field bus segments using interworking devices and a backbone network. A suitable backbone could be an ATM network. An interworking concept based on PROFIBUS/ATM bridges is presented in this paper. Simulations of an example PROFIBUS system were performed in order to study overall system behavior, to evaluate the feasibility of the presented concept and to show its limitations concerning the range of PROFIBUS applications it is suited for.
{"title":"Interworking between independent PROFIBUSes through ATM networks","authors":"O. Kunert","doi":"10.1109/IZSBC.2000.829245","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829245","url":null,"abstract":"Field buses have been developed to fulfil real-time requirements of applications related to factory automation. However, they can only cover geographical areas such as factory halls or buildings which causes the occurrence of many small segments in larger environments unable to communicate among each other. In order to reduce this drawback a possible solution is to connect those field bus segments using interworking devices and a backbone network. A suitable backbone could be an ATM network. An interworking concept based on PROFIBUS/ATM bridges is presented in this paper. Simulations of an example PROFIBUS system were performed in order to study overall system behavior, to evaluate the feasibility of the presented concept and to show its limitations concerning the range of PROFIBUS applications it is suited for.","PeriodicalId":409898,"journal":{"name":"2000 International Zurich Seminar on Broadband Communications. Accessing, Transmission, Networking. Proceedings (Cat. No.00TH8475)","volume":"85 4 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":"132690400","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.2000.829249
H. Widmer
Measurement data and computer modelling is used to assess the potential of global cumulative radio interference effects caused by over the horizon ionospheric propagation of unwanted emissions from broadband power line communications (PLC) systems operating in the HF band (1-30 MHz). A comparison of the results with the ITU-R atmospheric radio noise atlas indicates that the present natural noise levels in electromagnetic quiet areas will not change significantly with a possible future large deployment of local access telecommunication systems using the low voltage electricity distribution networks if the maximum transmit power spectral density per PLC cell (user group sharing the same spectral resources) is below -40 dBm (Hz/sup -1/).
{"title":"On the global EMC aspect of broadband power line communications using the \"HF\" frequency band","authors":"H. Widmer","doi":"10.1109/IZSBC.2000.829249","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829249","url":null,"abstract":"Measurement data and computer modelling is used to assess the potential of global cumulative radio interference effects caused by over the horizon ionospheric propagation of unwanted emissions from broadband power line communications (PLC) systems operating in the HF band (1-30 MHz). A comparison of the results with the ITU-R atmospheric radio noise atlas indicates that the present natural noise levels in electromagnetic quiet areas will not change significantly with a possible future large deployment of local access telecommunication systems using the low voltage electricity distribution networks if the maximum transmit power spectral density per PLC cell (user group sharing the same spectral resources) is below -40 dBm (Hz/sup -1/).","PeriodicalId":409898,"journal":{"name":"2000 International Zurich Seminar on Broadband Communications. Accessing, Transmission, Networking. Proceedings (Cat. No.00TH8475)","volume":"21 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":"124386994","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.2000.829247
C. Boutremans, J. Le Boudec
This paper shows that TCP Vegas' fairness critically requires an accurate estimation of propagation delay. We also show that, in practice, this may be difficult to achieve and we discuss how to choose the parameters /spl alpha/ and /spl beta/ that control the window sizes' update.
{"title":"A note on the fairness of TCP Vegas","authors":"C. Boutremans, J. Le Boudec","doi":"10.1109/IZSBC.2000.829247","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829247","url":null,"abstract":"This paper shows that TCP Vegas' fairness critically requires an accurate estimation of propagation delay. We also show that, in practice, this may be difficult to achieve and we discuss how to choose the parameters /spl alpha/ and /spl beta/ that control the window sizes' update.","PeriodicalId":409898,"journal":{"name":"2000 International Zurich Seminar on Broadband Communications. Accessing, Transmission, Networking. Proceedings (Cat. No.00TH8475)","volume":"26 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":"127513116","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.2000.829252
Tilman Wolf, Jonathan S. Turner
Active networking is a general approach to incorporating general-purpose computational capabilities within the communications infrastructure of data networks. This paper proposes the design of a scalable, high performance active router. This is used as a vehicle for studying the key design issues that must be resolved to allow active networking to become a mainstream technology.
{"title":"Design issues for high performance active routers","authors":"Tilman Wolf, Jonathan S. Turner","doi":"10.1109/IZSBC.2000.829252","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829252","url":null,"abstract":"Active networking is a general approach to incorporating general-purpose computational capabilities within the communications infrastructure of data networks. This paper proposes the design of a scalable, high performance active router. This is used as a vehicle for studying the key design issues that must be resolved to allow active networking to become a mainstream technology.","PeriodicalId":409898,"journal":{"name":"2000 International Zurich Seminar on Broadband Communications. Accessing, Transmission, Networking. Proceedings (Cat. No.00TH8475)","volume":"17 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":"124809329","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.2000.829226
A. Barreto, G. Fettweis
Mobile communications systems based on code division multiple access (CDMA) and direct sequence spread spectrum techniques have been gaining a lot of ground lately. The RAKE receiver is a well known technique in spread spectrum systems, which is used to obtain signal diversity in multipath environments. In TDD systems, a technique known as pre-RAKE has been proposed recently, in which the signal processing is transferred to the transmitter, and it has been shown that this technique provides a capacity increase in the downlink. In this paper we propose a combination of both methods and show that a substantial performance improvement can be reached this way.
{"title":"Performance improvement in DS-spread spectrum CDMA systems using a pre- and a post-RAKE","authors":"A. Barreto, G. Fettweis","doi":"10.1109/IZSBC.2000.829226","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829226","url":null,"abstract":"Mobile communications systems based on code division multiple access (CDMA) and direct sequence spread spectrum techniques have been gaining a lot of ground lately. The RAKE receiver is a well known technique in spread spectrum systems, which is used to obtain signal diversity in multipath environments. In TDD systems, a technique known as pre-RAKE has been proposed recently, in which the signal processing is transferred to the transmitter, and it has been shown that this technique provides a capacity increase in the downlink. In this paper we propose a combination of both methods and show that a substantial performance improvement can be reached this way.","PeriodicalId":409898,"journal":{"name":"2000 International Zurich Seminar on Broadband Communications. Accessing, Transmission, Networking. Proceedings (Cat. No.00TH8475)","volume":"46 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":"129608207","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.2000.829231
H. Mathis, P. Vontobel
The theoretical optimal shape of a small loop antenna within a rectangular area restriction is derived. Approaches with cut-off corners and rounded corners are proposed and optimal parameters (such as cut-off radius) are calculated. By means of the calculus of variation, a proof is given that the rounded-corner approach is indeed the optimal shape in terms of antenna efficiency if a simple model is assumed; the result is valid for any convex shape constraint.
{"title":"Shape optimization for a rectangularly constrained small loop antenna","authors":"H. Mathis, P. Vontobel","doi":"10.1109/IZSBC.2000.829231","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829231","url":null,"abstract":"The theoretical optimal shape of a small loop antenna within a rectangular area restriction is derived. Approaches with cut-off corners and rounded corners are proposed and optimal parameters (such as cut-off radius) are calculated. By means of the calculus of variation, a proof is given that the rounded-corner approach is indeed the optimal shape in terms of antenna efficiency if a simple model is assumed; the result is valid for any convex shape constraint.","PeriodicalId":409898,"journal":{"name":"2000 International Zurich Seminar on Broadband Communications. Accessing, Transmission, Networking. Proceedings (Cat. No.00TH8475)","volume":"5 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":"134218290","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.2000.829222
P. Kauffmann
The DS-CDMA spread spectrum protocol has a better spectral efficiency than TDMA or FDMA, which makes this modulation scheme the best candidate for third generation mobile communication systems. Nevertheless, this spectral efficiency is only achieved at the cost of an advanced power control of the mobile stations. The DS-CDMA protocol uses in all mobile telephone systems a closed loop power control scheme controlled by the base station receiver. This control system is, unfortunately, not fully efficient in certain critical cases. This paper presents a much faster method than the traditional power control scheme for a given data command rate, while keeping the traditional scheme of power control bit transmission used with the IS-95, CDMA2000 and W-CDMA standards. This method makes it possible to improve the QoS (quality of service) in the difficult cases without cost.
{"title":"Fast power control for third generation DS-CDMA mobile radio systems","authors":"P. Kauffmann","doi":"10.1109/IZSBC.2000.829222","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829222","url":null,"abstract":"The DS-CDMA spread spectrum protocol has a better spectral efficiency than TDMA or FDMA, which makes this modulation scheme the best candidate for third generation mobile communication systems. Nevertheless, this spectral efficiency is only achieved at the cost of an advanced power control of the mobile stations. The DS-CDMA protocol uses in all mobile telephone systems a closed loop power control scheme controlled by the base station receiver. This control system is, unfortunately, not fully efficient in certain critical cases. This paper presents a much faster method than the traditional power control scheme for a given data command rate, while keeping the traditional scheme of power control bit transmission used with the IS-95, CDMA2000 and W-CDMA standards. This method makes it possible to improve the QoS (quality of service) in the difficult cases without cost.","PeriodicalId":409898,"journal":{"name":"2000 International Zurich Seminar on Broadband Communications. Accessing, Transmission, Networking. Proceedings (Cat. No.00TH8475)","volume":"444 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":"124272160","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.2000.829267
H. Sari
This paper investigates the application of code-division multiple access (CDMA) to local multipoint distribution services (LMDS) networks. Our analysis shows that while conventional CDMA is superior to time-division multiple access (TDMA) in terms of worst-case interference on the upstream channel, it leads to higher interference on the downstream channel. Next, based on the observation that strong interference occurs only for a small range of user locations, we introduce a multimode CDMA concept which assigns orthogonal spreading sequences whose number and length are a function of the user position with respect to the base station (BS). We show that in terms of worst-case signal-to-interference ratio (SIR), the proposed technique leads to a substantial improvement with respect to conventional CDMA and TDMA.
{"title":"A multimode CDMA scheme with reduced intercell interference for LMDS networks","authors":"H. Sari","doi":"10.1109/IZSBC.2000.829267","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829267","url":null,"abstract":"This paper investigates the application of code-division multiple access (CDMA) to local multipoint distribution services (LMDS) networks. Our analysis shows that while conventional CDMA is superior to time-division multiple access (TDMA) in terms of worst-case interference on the upstream channel, it leads to higher interference on the downstream channel. Next, based on the observation that strong interference occurs only for a small range of user locations, we introduce a multimode CDMA concept which assigns orthogonal spreading sequences whose number and length are a function of the user position with respect to the base station (BS). We show that in terms of worst-case signal-to-interference ratio (SIR), the proposed technique leads to a substantial improvement with respect to conventional CDMA and TDMA.","PeriodicalId":409898,"journal":{"name":"2000 International Zurich Seminar on Broadband Communications. Accessing, Transmission, Networking. Proceedings (Cat. No.00TH8475)","volume":"41 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":"130793926","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.2000.829263
S. Stańczak, H. Boche
This paper addresses the problem of designing good spreading sequences for CDMA systems that have small-valued auto- and cross-correlation functions. In contrast to the usual mini-max criteria, the l/sup 2/ criteria of goodness are used to assess correlation properties of spreading sequences. To motivate it, direct evidence is given to demonstrate the utility of the l/sup 2/ criteria in the context of CDMA performance. Following, these criteria are applied to two types of known unit-magnitude sequences: generalized binary Rudin-Shapiro sequences, and sequences with quadratic phase function. The construction rule of the well-known binary Rudin-Shapiro sequences is based on a recursion formula that starts with the Kronecker sequences. It is shown that the asymptotic limits (N/spl rarr//spl infin/) of l/sup 2/ criteria obtained for original Rudin-Shapiro sequences are also valid in case of two arbitrary sequences obtained by means of the same recursion formula as long as the initial sequences are complementary. As to the sequences with quadratic phase function, the upper and lower bounds on the inverse merit-factor are proved to decrease with the order /spl radic/N+1, which indicates excellent auto-correlation properties of the sequence.
{"title":"Aperiodic properties of generalized binary Rudin-Shapiro sequences and some recent results on sequences with a quadratic phase function","authors":"S. Stańczak, H. Boche","doi":"10.1109/IZSBC.2000.829263","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829263","url":null,"abstract":"This paper addresses the problem of designing good spreading sequences for CDMA systems that have small-valued auto- and cross-correlation functions. In contrast to the usual mini-max criteria, the l/sup 2/ criteria of goodness are used to assess correlation properties of spreading sequences. To motivate it, direct evidence is given to demonstrate the utility of the l/sup 2/ criteria in the context of CDMA performance. Following, these criteria are applied to two types of known unit-magnitude sequences: generalized binary Rudin-Shapiro sequences, and sequences with quadratic phase function. The construction rule of the well-known binary Rudin-Shapiro sequences is based on a recursion formula that starts with the Kronecker sequences. It is shown that the asymptotic limits (N/spl rarr//spl infin/) of l/sup 2/ criteria obtained for original Rudin-Shapiro sequences are also valid in case of two arbitrary sequences obtained by means of the same recursion formula as long as the initial sequences are complementary. As to the sequences with quadratic phase function, the upper and lower bounds on the inverse merit-factor are proved to decrease with the order /spl radic/N+1, which indicates excellent auto-correlation properties of the sequence.","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":"129349545","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.2000.829257
K. Baum, B. Classon, Kevin Cutts, V. Desai
This paper studies the performance of a broadband OFDM system concept intended for fixed and nomadic applications. The system is designed for efficient packet data transmission, and in particular for TCP/IP. A combination of OFDM, adjustable time division duplexing (TDD), adaptive modulation/coding, and selective ARQ is used to provide a flexible and robust air interface. Estimates of the achievable data rates and spectral efficiencies under different deployment scenarios are obtained from a combination of link-level and system-level simulations.
{"title":"Performance analysis of an adaptive OFDM packet data system","authors":"K. Baum, B. Classon, Kevin Cutts, V. Desai","doi":"10.1109/IZSBC.2000.829257","DOIUrl":"https://doi.org/10.1109/IZSBC.2000.829257","url":null,"abstract":"This paper studies the performance of a broadband OFDM system concept intended for fixed and nomadic applications. The system is designed for efficient packet data transmission, and in particular for TCP/IP. A combination of OFDM, adjustable time division duplexing (TDD), adaptive modulation/coding, and selective ARQ is used to provide a flexible and robust air interface. Estimates of the achievable data rates and spectral efficiencies under different deployment scenarios are obtained from a combination of link-level and system-level simulations.","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":"116083306","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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