Pub Date : 1995-06-27DOI: 10.1109/SCAC.1995.523690
Y. Doganata, D. Gazis, A. Tantawi
An emerging application of mobile computing and communication is the delivery of information related to the transportation system to drivers and travelers. Such real-time information would be very valuable in providing services such as pre-trip planning, route guidance, intermodal transportation, yellow pages, and ride matching and reservation. This so-called advanced traveler information system (ATIS) is an important subset of an intelligent transportation system (ITS). The authors are developing an ATIS operational field test called SWIFT (Seattle wide-area information for travelers) in the Seattle metropolitan area which uses technological advances in wireless communication, personal digital assistants (PDA), and traffic modeling and analysis. SWIFT uses an advanced 19 kbps FM subcarrier broadcast medium for the delivery of transportation information as well as personal paging information. Preliminary description of the logical and physical architecture of the SWIFT system along with communication loading analysis for this system, are presented.
{"title":"A communication network architecture for transportation information systems","authors":"Y. Doganata, D. Gazis, A. Tantawi","doi":"10.1109/SCAC.1995.523690","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523690","url":null,"abstract":"An emerging application of mobile computing and communication is the delivery of information related to the transportation system to drivers and travelers. Such real-time information would be very valuable in providing services such as pre-trip planning, route guidance, intermodal transportation, yellow pages, and ride matching and reservation. This so-called advanced traveler information system (ATIS) is an important subset of an intelligent transportation system (ITS). The authors are developing an ATIS operational field test called SWIFT (Seattle wide-area information for travelers) in the Seattle metropolitan area which uses technological advances in wireless communication, personal digital assistants (PDA), and traffic modeling and analysis. SWIFT uses an advanced 19 kbps FM subcarrier broadcast medium for the delivery of transportation information as well as personal paging information. Preliminary description of the logical and physical architecture of the SWIFT system along with communication loading analysis for this system, are presented.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"19 1","pages":"368-374"},"PeriodicalIF":0.0,"publicationDate":"1995-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82821798","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 : 1995-06-27DOI: 10.1109/SCAC.1995.523653
A. Pattavina
ATM switch architectures based on deflection routing are examined and compared with regards to their internal operations. Their common feature is the availability of multiple I/O paths through a multistage unbuffered interconnection network where conflicts for the same internal link are dealt with, stage by stage, by deflecting the packets onto the wrong path. The main engineering parameter of the architecture, that is the number of network stages that provides a given packet loss performance, is studied. In particular it is found that basically all the examined architectures have a complexity on the order of Nlog/sub 2/N in the range of switch sizes of usual interest. Furthermore it has been possible to rank the architectures with comparable complexity based on the loss performance they provide.
{"title":"ATM switching based on deflection routing","authors":"A. Pattavina","doi":"10.1109/SCAC.1995.523653","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523653","url":null,"abstract":"ATM switch architectures based on deflection routing are examined and compared with regards to their internal operations. Their common feature is the availability of multiple I/O paths through a multistage unbuffered interconnection network where conflicts for the same internal link are dealt with, stage by stage, by deflecting the packets onto the wrong path. The main engineering parameter of the architecture, that is the number of network stages that provides a given packet loss performance, is studied. In particular it is found that basically all the examined architectures have a complexity on the order of Nlog/sub 2/N in the range of switch sizes of usual interest. Furthermore it has been possible to rank the architectures with comparable complexity based on the loss performance they provide.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"55 1","pages":"98-104"},"PeriodicalIF":0.0,"publicationDate":"1995-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75045470","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 : 1995-06-27DOI: 10.1109/SCAC.1995.523643
P. Zarros, Myung J. Lee, T. Saadawi
In this paper, an algorithm to determine the set of packets generated continuously and periodically from different participants that are arriving at a node either for mixing at the master of a conference, or for simply playing back at a regular participant of a conference, is proposed. The essence of the algorithm is to estimate the average packet arrival time (or reference time) for each participant. With the reference time at hand, the maximum jitter and the optimum waiting time for a mixer to wait packets from all participants can be determined. The error of the proposed algorithm is enumerated by the Chernoff bound and is shown to be acceptable in practical application.
{"title":"Statistical synchronization among participants in real-time multimedia conference","authors":"P. Zarros, Myung J. Lee, T. Saadawi","doi":"10.1109/SCAC.1995.523643","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523643","url":null,"abstract":"In this paper, an algorithm to determine the set of packets generated continuously and periodically from different participants that are arriving at a node either for mixing at the master of a conference, or for simply playing back at a regular participant of a conference, is proposed. The essence of the algorithm is to estimate the average packet arrival time (or reference time) for each participant. With the reference time at hand, the maximum jitter and the optimum waiting time for a mixer to wait packets from all participants can be determined. The error of the proposed algorithm is enumerated by the Chernoff bound and is shown to be acceptable in practical application.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"03 1","pages":"30-36"},"PeriodicalIF":0.0,"publicationDate":"1995-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80174172","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 : 1995-06-27DOI: 10.1109/SCAC.1995.523677
H. Soliman, Adel Said Elmaghraby, M. El-Sharkawy
A review of the state of the art in parallel and distributed simulation (PADS) is given. Sample performance results of currently used PADS techniques are presented using a network of workstations. The results demonstrate the capabilities and limitations of these techniques, and verify the logic of the current directions in PADS research.
{"title":"Parallel and distributed simulation: an overview","authors":"H. Soliman, Adel Said Elmaghraby, M. El-Sharkawy","doi":"10.1109/SCAC.1995.523677","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523677","url":null,"abstract":"A review of the state of the art in parallel and distributed simulation (PADS) is given. Sample performance results of currently used PADS techniques are presented using a network of workstations. The results demonstrate the capabilities and limitations of these techniques, and verify the logic of the current directions in PADS research.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"19 1","pages":"270-276"},"PeriodicalIF":0.0,"publicationDate":"1995-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85083184","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 : 1995-06-27DOI: 10.1109/SCAC.1995.523691
S. El-Henaoui, R. Coelho, S. Tohmé
Multimedia traffic is a special traffic consisting of different components (video, voice and data) belonging all to the same application and hence being strictly temporarily bounded. The jitter impact on multimedia (MM) traffic in ATM networks is analyzed. The inter-flows jitter (IFJ) parameter, that defines the jitter between several associated traffic flows is introduced. Furthermore, the jitter and IFJ are studied under two different multiplexing schemes namely, "all in one virtual path (VP)" and "one VP for each". An IFJ recovery mechanism (IFJ-rm) is finally proposed to restore the original traffic. Simulation results for the IFJ-rm under different scheduling disciplines are presented and discussed.
{"title":"Inter-flows jitter analysis for multimedia traffic in ATM networks","authors":"S. El-Henaoui, R. Coelho, S. Tohmé","doi":"10.1109/SCAC.1995.523691","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523691","url":null,"abstract":"Multimedia traffic is a special traffic consisting of different components (video, voice and data) belonging all to the same application and hence being strictly temporarily bounded. The jitter impact on multimedia (MM) traffic in ATM networks is analyzed. The inter-flows jitter (IFJ) parameter, that defines the jitter between several associated traffic flows is introduced. Furthermore, the jitter and IFJ are studied under two different multiplexing schemes namely, \"all in one virtual path (VP)\" and \"one VP for each\". An IFJ recovery mechanism (IFJ-rm) is finally proposed to restore the original traffic. Simulation results for the IFJ-rm under different scheduling disciplines are presented and discussed.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"126 1","pages":"377-383"},"PeriodicalIF":0.0,"publicationDate":"1995-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88707073","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 : 1995-06-27DOI: 10.1109/SCAC.1995.523672
S. El-Khamy, E. Youssef, H. Abdou
A soft decision decoder of linear block codes based on artificial neural networks (ANN) is presented. Various structures of the ANN decoder (ANND) are introduced and compared with the optimum soft-decision decoding (SDD) and hard-decision decoding (HDD) methods. Although the performance of the SDD is still optimum, the massive parallel nature of the neural network is shown to be more suitable to high data rate communication systems for which optimum decoding is impractical because of complexity and time consumption. The proposed ANND bridges the gap in performance and complexity between HDD and SDD. It is shown that the proposed receiver has superior performance in noisy channels with low signal to noise ratios.
{"title":"Soft decision decoding of block codes using artificial neural network","authors":"S. El-Khamy, E. Youssef, H. Abdou","doi":"10.1109/SCAC.1995.523672","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523672","url":null,"abstract":"A soft decision decoder of linear block codes based on artificial neural networks (ANN) is presented. Various structures of the ANN decoder (ANND) are introduced and compared with the optimum soft-decision decoding (SDD) and hard-decision decoding (HDD) methods. Although the performance of the SDD is still optimum, the massive parallel nature of the neural network is shown to be more suitable to high data rate communication systems for which optimum decoding is impractical because of complexity and time consumption. The proposed ANND bridges the gap in performance and complexity between HDD and SDD. It is shown that the proposed receiver has superior performance in noisy channels with low signal to noise ratios.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"48 1","pages":"234-240"},"PeriodicalIF":0.0,"publicationDate":"1995-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85851082","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 : 1995-06-27DOI: 10.1109/SCAC.1995.523658
Hitoshi Watanabe, H. Miyashita, Hiroshi Miyata, T. Abe
Customers of telecommunication services are strongly interested in the service outage time. In order to respond to these requirements, the following measures are now being investigated. The first is to keep the frequency of outages of which the duration time exceeds a certain length under a certain level, and the second is to inform the customers of the residual outages time when a service outage occurs. The evaluation and design method of the frequency of long outages has been developed in order to achieve the first objective. The prediction method of the residual outage time has also been developed for the second objective. Moreover, the software tool for assisting one to carry out those measures are also being developed. The outline of those evaluation and prediction methods and the software tool is described.
{"title":"Managing outage time of telecommunication services","authors":"Hitoshi Watanabe, H. Miyashita, Hiroshi Miyata, T. Abe","doi":"10.1109/SCAC.1995.523658","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523658","url":null,"abstract":"Customers of telecommunication services are strongly interested in the service outage time. In order to respond to these requirements, the following measures are now being investigated. The first is to keep the frequency of outages of which the duration time exceeds a certain length under a certain level, and the second is to inform the customers of the residual outages time when a service outage occurs. The evaluation and design method of the frequency of long outages has been developed in order to achieve the first objective. The prediction method of the residual outage time has also been developed for the second objective. Moreover, the software tool for assisting one to carry out those measures are also being developed. The outline of those evaluation and prediction methods and the software tool is described.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"12 1","pages":"134-140"},"PeriodicalIF":0.0,"publicationDate":"1995-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89642235","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 : 1995-05-01DOI: 10.1109/SCAC.1995.523649
H. Nussbaumer, S. Chutani
We propose a general technique for the fault diagnosis of communication networks that is inspired by the theory of system-level diagnosis. This technique relies on the paradigm of comparison testing. A set of tasks, possibly implicit, is executed by the nodes in a network. The resulting agreements and disagreements in their results are used to diagnose all the faulty nodes and links with a high probability. The diagnosis algorithm proposed is applicable in a centralized as well as a distributed system. The accuracy of the diagnosis is controlled by the number of rounds of tasks performed.
{"title":"On the distributed fault diagnosis of computer networks","authors":"H. Nussbaumer, S. Chutani","doi":"10.1109/SCAC.1995.523649","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523649","url":null,"abstract":"We propose a general technique for the fault diagnosis of communication networks that is inspired by the theory of system-level diagnosis. This technique relies on the paradigm of comparison testing. A set of tasks, possibly implicit, is executed by the nodes in a network. The resulting agreements and disagreements in their results are used to diagnose all the faulty nodes and links with a high probability. The diagnosis algorithm proposed is applicable in a centralized as well as a distributed system. The accuracy of the diagnosis is controlled by the number of rounds of tasks performed.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"51 1","pages":"71-77"},"PeriodicalIF":0.0,"publicationDate":"1995-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80041345","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 : 1995-01-01DOI: 10.1109/SCAC.1995.523687
P. van Rooyen
This work considers the performance of direct sequence spread spectrum multiple access (DS/SSMA) transmission with MRC diversity for cellular indoor wireless communication (IWC) channels, although it is not entirely restricted to the IWC channel. The indoor communication channel, which is multipath faded, is modelled by a discrete set of Nakagami faded paths. The Nakagami fading distribution has been shown to fit empirical results more generally than other distributions. New analytical results to evaluate the probability of error for the receiver terminals studied in this work are presented. Numerical results reveal that for nondiversity receivers, Nakagami fading is very hostile to the SSMA signal. However, with the use of MRC diversity, interleaving and convolutional coding, the average error rate can be reduced dramatically, allowing for reliable communication.
{"title":"DPSK performance of a coded SSMA system with microdiversity in a Nakagami fading environment","authors":"P. van Rooyen","doi":"10.1109/SCAC.1995.523687","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523687","url":null,"abstract":"This work considers the performance of direct sequence spread spectrum multiple access (DS/SSMA) transmission with MRC diversity for cellular indoor wireless communication (IWC) channels, although it is not entirely restricted to the IWC channel. The indoor communication channel, which is multipath faded, is modelled by a discrete set of Nakagami faded paths. The Nakagami fading distribution has been shown to fit empirical results more generally than other distributions. New analytical results to evaluate the probability of error for the receiver terminals studied in this work are presented. Numerical results reveal that for nondiversity receivers, Nakagami fading is very hostile to the SSMA signal. However, with the use of MRC diversity, interleaving and convolutional coding, the average error rate can be reduced dramatically, allowing for reliable communication.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"67 1","pages":"351-357"},"PeriodicalIF":0.0,"publicationDate":"1995-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82180260","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 : 1995-01-01DOI: 10.1109/SCAC.1995.523673
K. Ben Letaief
Over the past decade there has been considerable interest in using Monte Carlo (MC) simulation techniques for performance analysis of communications systems. Unfortunately, this approach often becomes intractable because of the prohibitive amount of simulation time required to achieve accurate estimates. Importance sampling is a modified MC technique which can result in a significant reduction in the computational cost required to obtain accurate MC estimates. We illustrate the use of importance sampling for simulating coded communications systems by presenting an efficient importance sampling methodology for simulating trellis code modulation (TCM) over Rayleigh fading channels. In particular, it is demonstrated that the proposed method can estimate the performance of these systems with a high degree of accuracy to warrant its possible use as a powerful tool for performance analysis and design of practical TCM systems.
{"title":"Performance and simulation of communications systems with applications to TCM over fading channels","authors":"K. Ben Letaief","doi":"10.1109/SCAC.1995.523673","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523673","url":null,"abstract":"Over the past decade there has been considerable interest in using Monte Carlo (MC) simulation techniques for performance analysis of communications systems. Unfortunately, this approach often becomes intractable because of the prohibitive amount of simulation time required to achieve accurate estimates. Importance sampling is a modified MC technique which can result in a significant reduction in the computational cost required to obtain accurate MC estimates. We illustrate the use of importance sampling for simulating coded communications systems by presenting an efficient importance sampling methodology for simulating trellis code modulation (TCM) over Rayleigh fading channels. In particular, it is demonstrated that the proposed method can estimate the performance of these systems with a high degree of accuracy to warrant its possible use as a powerful tool for performance analysis and design of practical TCM systems.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"43 1","pages":"241-247"},"PeriodicalIF":0.0,"publicationDate":"1995-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74543368","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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