Pub Date : 1995-06-27DOI: 10.1109/SCAC.1995.523688
J. Rahhal, G. Atkin
Modern wireless communication systems require an efficient use of the spectrum. Here we introduce the use of permutation codes (PC) as a combined source coding and channel modulation system using M-ary phase shift keying as the modulation formats. We combine the features of a permutation code vector quantizer and a permutation code as channel modulator. For source coding the permutation code is a class of constant weight vector quantizer, and its rate-distortion performance is near optimal considering practical vector lengths. We obtained the rate-total distortion performance for the combined system when an M-ary PSK modulation formats is used as channel symbols. The performance is obtained using numerical methods for AWGN channel and for frequency nonselective slowly fading channel. We found that the combined system has the advantage over non combined systems of lower encoding delay, and hence simpler transmitter and receiver. Also, we would be able to optimize the overall distortion as a function of the design parameters.
{"title":"Combined permutation codes using M-ary modulation for AWGN and fading channels","authors":"J. Rahhal, G. Atkin","doi":"10.1109/SCAC.1995.523688","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523688","url":null,"abstract":"Modern wireless communication systems require an efficient use of the spectrum. Here we introduce the use of permutation codes (PC) as a combined source coding and channel modulation system using M-ary phase shift keying as the modulation formats. We combine the features of a permutation code vector quantizer and a permutation code as channel modulator. For source coding the permutation code is a class of constant weight vector quantizer, and its rate-distortion performance is near optimal considering practical vector lengths. We obtained the rate-total distortion performance for the combined system when an M-ary PSK modulation formats is used as channel symbols. The performance is obtained using numerical methods for AWGN channel and for frequency nonselective slowly fading channel. We found that the combined system has the advantage over non combined systems of lower encoding delay, and hence simpler transmitter and receiver. Also, we would be able to optimize the overall distortion as a function of the design parameters.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"104 1","pages":"358-363"},"PeriodicalIF":0.0,"publicationDate":"1995-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78736519","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.1995.523650
T. Sauter, N. Kerö
Reliable real time data transmission ought to be able to tolerate both transient faults and line failures. The former are readily dealt with by employing appropriate error control coding, whereas the latter require multiple transmission lines. The conventional approach is to use one active and several standby channels. However, utilizing all available channels through multiple feeding and implementing active redundant receivers allows instantaneous recovery from line failures. We investigate such receiver structures for a data transmission system based on a double-error correcting BCH-code with underlying Manchester line coding and three parallel data links. Different approaches for implementing majority voting strategies are compared with respect to overall error handling capabilities. As a result we will propose an optimal structure called majority Manchester decoder requiring only moderate implementation overhead.
{"title":"Majority Manchester decoding for active redundant data transmission","authors":"T. Sauter, N. Kerö","doi":"10.1109/SCAC.1995.523650","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523650","url":null,"abstract":"Reliable real time data transmission ought to be able to tolerate both transient faults and line failures. The former are readily dealt with by employing appropriate error control coding, whereas the latter require multiple transmission lines. The conventional approach is to use one active and several standby channels. However, utilizing all available channels through multiple feeding and implementing active redundant receivers allows instantaneous recovery from line failures. We investigate such receiver structures for a data transmission system based on a double-error correcting BCH-code with underlying Manchester line coding and three parallel data links. Different approaches for implementing majority voting strategies are compared with respect to overall error handling capabilities. As a result we will propose an optimal structure called majority Manchester decoder requiring only moderate implementation overhead.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"461 1","pages":"78-82"},"PeriodicalIF":0.0,"publicationDate":"1995-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76354698","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.1995.523685
Jyh-Horng Wu, Jingshown Wu, Yang-Han Lee
A study of the multichannel coherent CPFSK communication system employing Reed-Solomon codes is reported. The crosstalk between adjacent channels, the impact of the laser phase noise, and selection of the optimum code rate are investigated. By applying a suitable coding scheme, the laser linewidth can be greatly relaxed, and the receiver sensitivity will be remarkably improved. A 100 Mbit/s system is used to verify the coding benefit. The results show that the impact of the laser linewidth can be largely alleviated by applying a (255, 223) Reed-Solomon code. When the linewidth is fixed (/spl Delta//spl nu/T=2%), this code can improve the receiver sensitivity by more than 15 dB.
{"title":"Coding to relax laser linewidth requirements for multichannel CPFSK coherent optical communications","authors":"Jyh-Horng Wu, Jingshown Wu, Yang-Han Lee","doi":"10.1109/SCAC.1995.523685","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523685","url":null,"abstract":"A study of the multichannel coherent CPFSK communication system employing Reed-Solomon codes is reported. The crosstalk between adjacent channels, the impact of the laser phase noise, and selection of the optimum code rate are investigated. By applying a suitable coding scheme, the laser linewidth can be greatly relaxed, and the receiver sensitivity will be remarkably improved. A 100 Mbit/s system is used to verify the coding benefit. The results show that the impact of the laser linewidth can be largely alleviated by applying a (255, 223) Reed-Solomon code. When the linewidth is fixed (/spl Delta//spl nu/T=2%), this code can improve the receiver sensitivity by more than 15 dB.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"31 1","pages":"338-343"},"PeriodicalIF":0.0,"publicationDate":"1995-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91227697","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.1995.523651
Lily Cheng, H. Hughes
Traffic measurements taken from real data are highly desirable for validating traffic models, designing congestion control and flow control algorithms, implementing communication protocols, and developing switch architectures. This paper investigates the traffic characteristics of several applications in an ATM network with the goal of studying bursty traffic behavior and realizing the multiplexing effects of variable bit rate (VBR) traffic. Specifically, three types of traffic (ftp, voice, and video) are obtained from an ATM testbed. These applications are reported to be important applications that tend to dominate the wide-area networks. The multiplexing effects of FTP traffic are studied to identify empirical bandwidth requirements. The characteristics of the multiplexing effects can be applied to develop an efficient call admission algorithm based on the measured data. These experimental results designed to investigate traffic characteristics provide insights to bursty traffic behavior and performance requirements of practical real-time loads.
{"title":"On the multiplexing effects of the ATM traffic","authors":"Lily Cheng, H. Hughes","doi":"10.1109/SCAC.1995.523651","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523651","url":null,"abstract":"Traffic measurements taken from real data are highly desirable for validating traffic models, designing congestion control and flow control algorithms, implementing communication protocols, and developing switch architectures. This paper investigates the traffic characteristics of several applications in an ATM network with the goal of studying bursty traffic behavior and realizing the multiplexing effects of variable bit rate (VBR) traffic. Specifically, three types of traffic (ftp, voice, and video) are obtained from an ATM testbed. These applications are reported to be important applications that tend to dominate the wide-area networks. The multiplexing effects of FTP traffic are studied to identify empirical bandwidth requirements. The characteristics of the multiplexing effects can be applied to develop an efficient call admission algorithm based on the measured data. These experimental results designed to investigate traffic characteristics provide insights to bursty traffic behavior and performance requirements of practical real-time loads.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"16 1","pages":"84-90"},"PeriodicalIF":0.0,"publicationDate":"1995-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90375717","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.1995.523176
I. Rubin, Kirk K. Chang
We consider a voice multiplexer which supports ATM packet voice traffic. This system model also applies to the multiplexing operation carried out at the output queue of each output queueing ATM switch. The voice multiplexer implements an encoding algorithm under which the voice quantization levels are dynamically adjusted according to the congestion status of the multiplexer. Using an embedded voice encoding scheme, a voice packet is encoded into lower and higher priority ATM cells. When high congestion conditions are observed, lower priority voice cells (which contain the least significant bits) are discarded. In previous studies, the voice quality under a dynamic encoding algorithm has been described by the long-term average voice encoding rate (AER/sub /spl infin//). Due to the strong correlation properties exhibited by the packet voice traffic, the voice degradation levels incurred under the employed dynamic voice encoding algorithms are not distributed uniformly among the voice sources. As a result, the encoded voice stream for a source can exhibit severe short-term voice quality degradation, while the long-term AER/sub /spl infin// level remains satisfactory. To correct this situation, we introduce in this paper a "probabilistic" component in the cell-discarding process. A voice degradation indicator (VDI) is introduced to measure the short-term voice quality degradation experienced by a voice stream. Through numerical examples, we identify and compare the system performance under the deterministic and probabilistic algorithms. Under the same AER/sub /spl infin// levels, a probabilistic algorithm is shown to yield better short-term voice quality behavior as well as to improve the mean cell waiting time performance.
{"title":"On improving voice quality under dynamic encoding algorithms in ATM networks","authors":"I. Rubin, Kirk K. Chang","doi":"10.1109/SCAC.1995.523176","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523176","url":null,"abstract":"We consider a voice multiplexer which supports ATM packet voice traffic. This system model also applies to the multiplexing operation carried out at the output queue of each output queueing ATM switch. The voice multiplexer implements an encoding algorithm under which the voice quantization levels are dynamically adjusted according to the congestion status of the multiplexer. Using an embedded voice encoding scheme, a voice packet is encoded into lower and higher priority ATM cells. When high congestion conditions are observed, lower priority voice cells (which contain the least significant bits) are discarded. In previous studies, the voice quality under a dynamic encoding algorithm has been described by the long-term average voice encoding rate (AER/sub /spl infin//). Due to the strong correlation properties exhibited by the packet voice traffic, the voice degradation levels incurred under the employed dynamic voice encoding algorithms are not distributed uniformly among the voice sources. As a result, the encoded voice stream for a source can exhibit severe short-term voice quality degradation, while the long-term AER/sub /spl infin// level remains satisfactory. To correct this situation, we introduce in this paper a \"probabilistic\" component in the cell-discarding process. A voice degradation indicator (VDI) is introduced to measure the short-term voice quality degradation experienced by a voice stream. Through numerical examples, we identify and compare the system performance under the deterministic and probabilistic algorithms. Under the same AER/sub /spl infin// levels, a probabilistic algorithm is shown to yield better short-term voice quality behavior as well as to improve the mean cell waiting time performance.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"46 1","pages":"9-15"},"PeriodicalIF":0.0,"publicationDate":"1995-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76728370","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.1995.523686
A. Al-Sanie
In this paper, we present a new type-II hybrid ARQ scheme. This scheme employs block coded modulation (BCM) for error-correction and a linear block code for error-detection. This scheme is referred to as the BCM-ARQ scheme. Rate 1/2 block code with QPSK as error-correction code is considered. Computer simulation is used to evaluate the throughput of the proposed scheme. In comparison with the classical ARQ schemes, the proposed ARQ scheme provides enhanced throughput under high probability of error conditions without any increase in the bandwidth. A BCM-ARQ scheme with combining of successive received blocks is also introduced. In this scheme, the decoder for error correction operates on combination of all received sequences for a block, rather than only on the most recent received one. It is shown that blocks combining further improves the throughput of the BCM-ARQ scheme for higher channel error rate.
{"title":"Block coded modulation based ARQ schemes with blocks combining","authors":"A. Al-Sanie","doi":"10.1109/SCAC.1995.523686","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523686","url":null,"abstract":"In this paper, we present a new type-II hybrid ARQ scheme. This scheme employs block coded modulation (BCM) for error-correction and a linear block code for error-detection. This scheme is referred to as the BCM-ARQ scheme. Rate 1/2 block code with QPSK as error-correction code is considered. Computer simulation is used to evaluate the throughput of the proposed scheme. In comparison with the classical ARQ schemes, the proposed ARQ scheme provides enhanced throughput under high probability of error conditions without any increase in the bandwidth. A BCM-ARQ scheme with combining of successive received blocks is also introduced. In this scheme, the decoder for error correction operates on combination of all received sequences for a block, rather than only on the most recent received one. It is shown that blocks combining further improves the throughput of the BCM-ARQ scheme for higher channel error rate.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"26 1","pages":"346-350"},"PeriodicalIF":0.0,"publicationDate":"1995-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82255600","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.1995.523683
Osman ZeinElDine, H. Abdel-Wahab
The state of the art in reliable multicasting protocols renders itself inadequate for group multicasting in environments where both intra-group and inter-group messages bridge several LANs. A particularly difficult situation arises if some LANs are managed by autonomous authorities. If autonomy is upheld, as a defacto condition, then LANs under different authorities can adopt different ordering criteria for group multicasting. The accommodation of heterogeneous ordering criteria is a problem that has been largely ignored. The authors propose the multi-LAN multi-order (MLMO) protocol, which supports a reliable ordered delivery service for both local and global messages. The MLMO protocol assumes an environment in which multicasting groups can have members belonging to different LANs, and each group can adopt either total or causal order for message delivery to its members. Characteristic to the protocol is a communication structure that can be aligned with the actual routing topology; thus, the number of necessary protocol messages is maintained. Furthermore, groups that adopt causal order are not forced to experience message latency solely because of coexisting groups that adopt total order.
{"title":"Multicasting in interconnected networks","authors":"Osman ZeinElDine, H. Abdel-Wahab","doi":"10.1109/SCAC.1995.523683","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523683","url":null,"abstract":"The state of the art in reliable multicasting protocols renders itself inadequate for group multicasting in environments where both intra-group and inter-group messages bridge several LANs. A particularly difficult situation arises if some LANs are managed by autonomous authorities. If autonomy is upheld, as a defacto condition, then LANs under different authorities can adopt different ordering criteria for group multicasting. The accommodation of heterogeneous ordering criteria is a problem that has been largely ignored. The authors propose the multi-LAN multi-order (MLMO) protocol, which supports a reliable ordered delivery service for both local and global messages. The MLMO protocol assumes an environment in which multicasting groups can have members belonging to different LANs, and each group can adopt either total or causal order for message delivery to its members. Characteristic to the protocol is a communication structure that can be aligned with the actual routing topology; thus, the number of necessary protocol messages is maintained. Furthermore, groups that adopt causal order are not forced to experience message latency solely because of coexisting groups that adopt total order.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"58 1","pages":"313-319"},"PeriodicalIF":0.0,"publicationDate":"1995-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77745375","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.1995.523175
G. Konstantoulakis, G. Stassinopoulos
The paper contributes to currently debated key issues on the evolution of ATM networks and their standardisation. It takes the view that since the asynchronous transfer mode has features of both circuit and packet switching, one has to selectively draw benefits for different types of traffic, compromising, if necessary, the integration principle. The use of the available bit rate (ABR), promoted by the ATM Forum for handling time insensitive (best effort) traffic, is fully adopted and its influence on switching discussed in detail. Coupled with ABR for transmission, the paper supports the employment of massive memory within the switching equipment. By suggesting solutions to key memory management problems, it also examines the use of X.25-like flow and congestion control, selectively employed for data transfer over ATM networks.
{"title":"Transfer of data over ATM networks using available bit rate (ABR)","authors":"G. Konstantoulakis, G. Stassinopoulos","doi":"10.1109/SCAC.1995.523175","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523175","url":null,"abstract":"The paper contributes to currently debated key issues on the evolution of ATM networks and their standardisation. It takes the view that since the asynchronous transfer mode has features of both circuit and packet switching, one has to selectively draw benefits for different types of traffic, compromising, if necessary, the integration principle. The use of the available bit rate (ABR), promoted by the ATM Forum for handling time insensitive (best effort) traffic, is fully adopted and its influence on switching discussed in detail. Coupled with ABR for transmission, the paper supports the employment of massive memory within the switching equipment. By suggesting solutions to key memory management problems, it also examines the use of X.25-like flow and congestion control, selectively employed for data transfer over ATM networks.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"33 1","pages":"2-8"},"PeriodicalIF":0.0,"publicationDate":"1995-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79346619","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.1995.523654
J. Cobb, M. Gouda
We present a family of transport protocols for transmitting messages from a sender process to a receiver process over multiple one-way channels (that represent virtual circuits). Each channel may lose but not reorder nor duplicate messages. The sender process distributes its messages among the channels in a round-robin manner for purposes of load balancing and fault-tolerance. The receiver process receives messages from the different channels in arbitrary order, but it delivers them in the same order in which they were sent, despite the fact that some messages may have been lost during transmission. The protocols in our protocol family support two delivery requirements: no deadline delivery, in which the receiver may wait to receive a message from each channel before delivering the next message, and deadline delivery, in which each message is to be delivered before a given deadline.
{"title":"Ordered Delivery over One-way Virtual Circuits","authors":"J. Cobb, M. Gouda","doi":"10.1109/SCAC.1995.523654","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523654","url":null,"abstract":"We present a family of transport protocols for transmitting messages from a sender process to a receiver process over multiple one-way channels (that represent virtual circuits). Each channel may lose but not reorder nor duplicate messages. The sender process distributes its messages among the channels in a round-robin manner for purposes of load balancing and fault-tolerance. The receiver process receives messages from the different channels in arbitrary order, but it delivers them in the same order in which they were sent, despite the fact that some messages may have been lost during transmission. The protocols in our protocol family support two delivery requirements: no deadline delivery, in which the receiver may wait to receive a message from each channel before delivering the next message, and deadline delivery, in which each message is to be delivered before a given deadline.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"29 1","pages":"105-111"},"PeriodicalIF":0.0,"publicationDate":"1995-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75535526","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.1995.523684
A. Elrefaie
Summary form only given. SONET technology has made high speed self-healing ring architectures practical and economical for interoffice network applications. Self-healing ring networks using electronic add-drop multiplexers (SONET ADMs) are limited in capacity to about 10 Gb/s by the electronics. Elrefaie (1993) proposed a multiwavelength interoffice ring architecture for high capacity transport applications. Two types of multiwavelength ring have been proposed: one uses two fibers and the automatic protection switching capability of standard uni-directional SONET ADMs; the other uses four fibers together with a new capability for automatic protection using optical switching and uni-directional SONET ADMs. Both can be designed to be consistent with present SONET standards, allowing graceful upgrades from electronic SONET rings to multiwavelength SONET rings. In multiwavelength interoffice ring networks, WDM signals traverse a cascade of erbium-doped fiber amplifiers (EDFAs), each followed by optical drop-and-insert multiplexers. The amplifiers' non-flat gain spectra impose size and capacity limits that depend on the network types and the specific drop-and-insert arrangements of the network. Also, WDM signals pass through a number of concatenated optical filters which leads to network performance degradations due to laser and filter passband misalignments arising from device imperfections and temperature variations. The paper evaluates the accumulation of performance degradations in multiwavelength interoffice ring networks. The author also suggests several techniques to overcome performance degradations of multiwavelength networks.
{"title":"Performance limitations of multiwavelength interoffice ring networks","authors":"A. Elrefaie","doi":"10.1109/SCAC.1995.523684","DOIUrl":"https://doi.org/10.1109/SCAC.1995.523684","url":null,"abstract":"Summary form only given. SONET technology has made high speed self-healing ring architectures practical and economical for interoffice network applications. Self-healing ring networks using electronic add-drop multiplexers (SONET ADMs) are limited in capacity to about 10 Gb/s by the electronics. Elrefaie (1993) proposed a multiwavelength interoffice ring architecture for high capacity transport applications. Two types of multiwavelength ring have been proposed: one uses two fibers and the automatic protection switching capability of standard uni-directional SONET ADMs; the other uses four fibers together with a new capability for automatic protection using optical switching and uni-directional SONET ADMs. Both can be designed to be consistent with present SONET standards, allowing graceful upgrades from electronic SONET rings to multiwavelength SONET rings. In multiwavelength interoffice ring networks, WDM signals traverse a cascade of erbium-doped fiber amplifiers (EDFAs), each followed by optical drop-and-insert multiplexers. The amplifiers' non-flat gain spectra impose size and capacity limits that depend on the network types and the specific drop-and-insert arrangements of the network. Also, WDM signals pass through a number of concatenated optical filters which leads to network performance degradations due to laser and filter passband misalignments arising from device imperfections and temperature variations. The paper evaluates the accumulation of performance degradations in multiwavelength interoffice ring networks. The author also suggests several techniques to overcome performance degradations of multiwavelength networks.","PeriodicalId":90699,"journal":{"name":"Proceedings. IEEE Symposium on Computers and Communications","volume":"20 1","pages":"327-"},"PeriodicalIF":0.0,"publicationDate":"1995-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80092361","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：