Pub Date : 2006-07-01DOI: 10.1109/GLOCOM.2002.1189120
H. Takagi, Yongbing Zhang, H. Takagi
We propose several heuristic algorithms that reconfigure logical topologies in wide-area wavelength-routed optical networks. Our reconfiguration algorithms attempt to keep the network availability as much as possible during the reconfiguration process. For this purpose, a lightpath is taken as the minimum unit of reconfiguration, which is an all-optical wavelength-division multiplexed (WDM) channel. The proposed algorithms are evaluated by using an NFSNFT-like network model with 16 nodes and 25 links. The results show that very simple algorithms provide very small computational complexity but poor performance, i.e., bad network availability, and that an efficient algorithm provides reasonable computational complexity and very good performance. More complex algorithms may improve performance somewhat further but have unrealistically large computational complexity.
{"title":"Reconfiguration heuristics for logical topologies in wide-area WDM networks","authors":"H. Takagi, Yongbing Zhang, H. Takagi","doi":"10.1109/GLOCOM.2002.1189120","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1189120","url":null,"abstract":"We propose several heuristic algorithms that reconfigure logical topologies in wide-area wavelength-routed optical networks. Our reconfiguration algorithms attempt to keep the network availability as much as possible during the reconfiguration process. For this purpose, a lightpath is taken as the minimum unit of reconfiguration, which is an all-optical wavelength-division multiplexed (WDM) channel. The proposed algorithms are evaluated by using an NFSNFT-like network model with 16 nodes and 25 links. The results show that very simple algorithms provide very small computational complexity but poor performance, i.e., bad network availability, and that an efficient algorithm provides reasonable computational complexity and very good performance. More complex algorithms may improve performance somewhat further but have unrealistically large computational complexity.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116859444","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 : 2004-09-01DOI: 10.1109/GLOCOM.2002.1188222
Jiun-Long Huang, Nfing-Syan Chen
Data broadcasting is a promising technique to improve the bandwidth utilization and conserve the power consumption in a mobile computing environment. In many applications, the data items broadcast are dependent upon one another. However, most prior studies on broadcasting dependent data are restricted to a single broadcast channel environment which imposes an impractical limitation. In view of this, we explore in this paper the problem of broadcasting dependent date in multiple broadcast channels. By analyzing the model of dependent data broadcasting, we derive several theoretical properties for the average access time in a multiple channel environment. In light of the theoretical results, we develop a genetic algorithm to generate broadcast programs. Our experimental results show that the theoretical results derived are able to guide the search of the genetic algorithm very effectively, thus leading to solution broadcast programs of very high quality.
{"title":"Dependent data broadcasting for unordered queries in a multiple channel mobile environment","authors":"Jiun-Long Huang, Nfing-Syan Chen","doi":"10.1109/GLOCOM.2002.1188222","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1188222","url":null,"abstract":"Data broadcasting is a promising technique to improve the bandwidth utilization and conserve the power consumption in a mobile computing environment. In many applications, the data items broadcast are dependent upon one another. However, most prior studies on broadcasting dependent data are restricted to a single broadcast channel environment which imposes an impractical limitation. In view of this, we explore in this paper the problem of broadcasting dependent date in multiple broadcast channels. By analyzing the model of dependent data broadcasting, we derive several theoretical properties for the average access time in a multiple channel environment. In light of the theoretical results, we develop a genetic algorithm to generate broadcast programs. Our experimental results show that the theoretical results derived are able to guide the search of the genetic algorithm very effectively, thus leading to solution broadcast programs of very high quality.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123441691","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 : 2003-07-22DOI: 10.1109/GLOCOM.2002.1188429
A. Ramesh, A. Chockalingam, L. Milstein
In this paper, we analyze the performance of trellis coded modulation (TCM) schemes with generalized selection combining (GSC) on fading channels. We first derive the computational cutoff rate, R/sub 0/, for coherent TCM schemes on i.i.d. Rayleigh fading channels with (K, L) GSC diversity which combines the K paths with the largest instantaneous SNR among the L available diversity paths. The cutoff rate is shown to be a simple function of the moment generating function (MGF) of the SNR at the output of the (K, L) GSC receiver. The cutoff rate results show that, at a cutoff rate of 1 bit/sec/Hz, 8-PSK modulation with (1, 3) GSC requires about the same E/sub b//N/sub 0/ as QPSK modulation with (2,3) GSC. Also, at 1.5 bits/sec/Hz, 8-PSK with (1, 3) GSC and QPSK with (3,3) GSC require about the same E/sub b//N/sub 0/. This illustrates that in TCM schemes with GSC diversity, the modulation complexity (i.e., alphabet size, M) and the GSC receiver complexity (i.e., the number of combined diversity paths, K) can be traded off to achieve a desired performance. Next, we derive the union bound on the bit error probability of TCM schemes with (K, L) GSC reception in the form of a simple, finite integral. The effectiveness of this bound is verified through simulations.
{"title":"Performance analysis of TCM with generalized selection combining on Rayleigh fading channels","authors":"A. Ramesh, A. Chockalingam, L. Milstein","doi":"10.1109/GLOCOM.2002.1188429","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1188429","url":null,"abstract":"In this paper, we analyze the performance of trellis coded modulation (TCM) schemes with generalized selection combining (GSC) on fading channels. We first derive the computational cutoff rate, R/sub 0/, for coherent TCM schemes on i.i.d. Rayleigh fading channels with (K, L) GSC diversity which combines the K paths with the largest instantaneous SNR among the L available diversity paths. The cutoff rate is shown to be a simple function of the moment generating function (MGF) of the SNR at the output of the (K, L) GSC receiver. The cutoff rate results show that, at a cutoff rate of 1 bit/sec/Hz, 8-PSK modulation with (1, 3) GSC requires about the same E/sub b//N/sub 0/ as QPSK modulation with (2,3) GSC. Also, at 1.5 bits/sec/Hz, 8-PSK with (1, 3) GSC and QPSK with (3,3) GSC require about the same E/sub b//N/sub 0/. This illustrates that in TCM schemes with GSC diversity, the modulation complexity (i.e., alphabet size, M) and the GSC receiver complexity (i.e., the number of combined diversity paths, K) can be traded off to achieve a desired performance. Next, we derive the union bound on the bit error probability of TCM schemes with (K, L) GSC reception in the form of a simple, finite integral. The effectiveness of this bound is verified through simulations.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133998212","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 : 2002-12-01DOI: 10.1109/GLOCOM.2002.1188167
N. Ahmed, Richard Baraniuk
Many wireless systems exploit transmit diversity for more reliable detection of signals at the receiver. To accomplish this, coding is spread across multiple transmit antennas. An example of this is the well known "Alamouti transmit diversity", where a very simple coding scheme across multiple transmit antennas allows systems to attain performance similar to systems with multiple receive antennas. The major drawback is that this system only works when a "flat-fading" model for the channel is assumed; when used in a multipath environment, the system breaks down. Here we show that when the Alamouti code is placed within an OFDM structure, using adjacent frequency bands rather than consecutive symbol intervals, it can asymptotically achieve the same performance in multipath fading as the Alamouti code in flat-fading.
{"title":"Asymptotic performance of transmit diversity via OFDM for multipath channels","authors":"N. Ahmed, Richard Baraniuk","doi":"10.1109/GLOCOM.2002.1188167","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1188167","url":null,"abstract":"Many wireless systems exploit transmit diversity for more reliable detection of signals at the receiver. To accomplish this, coding is spread across multiple transmit antennas. An example of this is the well known \"Alamouti transmit diversity\", where a very simple coding scheme across multiple transmit antennas allows systems to attain performance similar to systems with multiple receive antennas. The major drawback is that this system only works when a \"flat-fading\" model for the channel is assumed; when used in a multipath environment, the system breaks down. Here we show that when the Alamouti code is placed within an OFDM structure, using adjacent frequency bands rather than consecutive symbol intervals, it can asymptotically achieve the same performance in multipath fading as the Alamouti code in flat-fading.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129946653","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 : 2002-12-01DOI: 10.1109/GLOCOM.2002.1189061
T. Korkmaz, M. Krunz
Current link-state routing protocols (e.g., OSPF) use flooding to disseminate link-state information throughout the network. Despite its simplicity and reliability, flooding incurs unnecessary communications overhead since nodes may receive multiple copies of the same advertisement. This extra overhead becomes an Issue in the context of quality-of-service (QoS) routing, where link state is dynamic and needs to be advertised frequently. The advertisement overhead can be significantly reduced by using tree-based broadcasting approaches. Although several of these approaches have been proposed in the literature, they are not used in practice because of their complexity and/or unreliability. We propose a new link-state dissemination approach that combines the best features of flooding and tree-based broadcasting. Our hybrid approach is particularly suited for "dynamic" link metrics (e.g., available bandwidth). It uses periodic flooding to advertise topology changes and first-time LSAs (link-state advertisements), and uses tree-based broadcasting to disseminate subsequent refresh LSAs. The broadcast trees in our approach are constructed dynamically during the flooding of the first LSA, without the need for the complex algorithms of previous tree-based approaches. Two versions of our dissemination approach are presented, with one being more suitable for networks with frequent topological changes. We prove the correctness of our approach and contrast its communications overhead with flooding and pure tree-based broadcasting. The results indicate that our hybrid approach has a significantly lower overhead than flooding; yet It enjoys the simplicity, reliability, and fast convergence of flooding. Finally, we outline how OSPF can be extended to support the proposed dissemination approach.
{"title":"Hybrid flooding and tree-based broadcasting for reliable and efficient link-state dissemination","authors":"T. Korkmaz, M. Krunz","doi":"10.1109/GLOCOM.2002.1189061","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1189061","url":null,"abstract":"Current link-state routing protocols (e.g., OSPF) use flooding to disseminate link-state information throughout the network. Despite its simplicity and reliability, flooding incurs unnecessary communications overhead since nodes may receive multiple copies of the same advertisement. This extra overhead becomes an Issue in the context of quality-of-service (QoS) routing, where link state is dynamic and needs to be advertised frequently. The advertisement overhead can be significantly reduced by using tree-based broadcasting approaches. Although several of these approaches have been proposed in the literature, they are not used in practice because of their complexity and/or unreliability. We propose a new link-state dissemination approach that combines the best features of flooding and tree-based broadcasting. Our hybrid approach is particularly suited for \"dynamic\" link metrics (e.g., available bandwidth). It uses periodic flooding to advertise topology changes and first-time LSAs (link-state advertisements), and uses tree-based broadcasting to disseminate subsequent refresh LSAs. The broadcast trees in our approach are constructed dynamically during the flooding of the first LSA, without the need for the complex algorithms of previous tree-based approaches. Two versions of our dissemination approach are presented, with one being more suitable for networks with frequent topological changes. We prove the correctness of our approach and contrast its communications overhead with flooding and pure tree-based broadcasting. The results indicate that our hybrid approach has a significantly lower overhead than flooding; yet It enjoys the simplicity, reliability, and fast convergence of flooding. Finally, we outline how OSPF can be extended to support the proposed dissemination approach.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115997202","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 : 2002-12-01DOI: 10.1109/GLOCOM.2002.1189126
N. Yamanaka, M. Katayama, K. Shiomoto, E. Oki, N. Matsuura
The paper describes multi-layer traffic engineering and signaling technologies in photonic-GMPLS-router networks. Multi-layer traffic engineering, which yields the dynamic cooperation of IP and photonic layers for providing IP services cost-effectively, is described. To realize multi-layer traffic engineering, we propose an OSPF extension that advertises both the number of total wavelengths and the number of unused wavelengths and an RSVP-TE extension that minimizes the number of wavelength conversions needed. In addition, the paper presents a heuristic-based multi-layer topology design scheme that uses IP traffic measurements in a generalized multiprotocol label switch (GMPLS). Our design scheme yields the optical label switch path (OLSP) network topology, i.e. OLSP placement, that minimizes network cost, in response to fluctuations in IP traffic demand. In other words, the OLSP network topology is dynamically reconfigured to match IP traffic demand. Networks are reconfigured by the proposed scheme so as to utilize the network resources in the most cost-effective manner.
{"title":"Multi-layer traffic engineering in photonic-GMPLS-router networks","authors":"N. Yamanaka, M. Katayama, K. Shiomoto, E. Oki, N. Matsuura","doi":"10.1109/GLOCOM.2002.1189126","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1189126","url":null,"abstract":"The paper describes multi-layer traffic engineering and signaling technologies in photonic-GMPLS-router networks. Multi-layer traffic engineering, which yields the dynamic cooperation of IP and photonic layers for providing IP services cost-effectively, is described. To realize multi-layer traffic engineering, we propose an OSPF extension that advertises both the number of total wavelengths and the number of unused wavelengths and an RSVP-TE extension that minimizes the number of wavelength conversions needed. In addition, the paper presents a heuristic-based multi-layer topology design scheme that uses IP traffic measurements in a generalized multiprotocol label switch (GMPLS). Our design scheme yields the optical label switch path (OLSP) network topology, i.e. OLSP placement, that minimizes network cost, in response to fluctuations in IP traffic demand. In other words, the OLSP network topology is dynamically reconfigured to match IP traffic demand. Networks are reconfigured by the proposed scheme so as to utilize the network resources in the most cost-effective manner.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122392178","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 : 2002-12-01DOI: 10.1109/GLOCOM.2002.1189002
Walter Eaves, Lawrence Cheng, A. Galis, T. Becker, Toshiaki Suzuki, S. Denazis, Chiho Kitahara
This paper proposes a new efficient mechanism for controlling and managing the resources within and around the active nodes: routers and switches that have a legacy SNMP management system. Existing system such as ABLE has an out-of- band management capability, which is insufficient for managing data flow as the flow progresses through the network. This paper proposes the use of the combined approach of SNAP and SNMP as an efficient network resource management mechanism on the FAIN active nodes. It has an in-band management approach in which each data flow will negotiate its next hop before it goes there; or it can create IPSec tunnels and modify routing table entries for the data flow.
{"title":"SNAP based resource control for active networks","authors":"Walter Eaves, Lawrence Cheng, A. Galis, T. Becker, Toshiaki Suzuki, S. Denazis, Chiho Kitahara","doi":"10.1109/GLOCOM.2002.1189002","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1189002","url":null,"abstract":"This paper proposes a new efficient mechanism for controlling and managing the resources within and around the active nodes: routers and switches that have a legacy SNMP management system. Existing system such as ABLE has an out-of- band management capability, which is insufficient for managing data flow as the flow progresses through the network. This paper proposes the use of the combined approach of SNAP and SNMP as an efficient network resource management mechanism on the FAIN active nodes. It has an in-band management approach in which each data flow will negotiate its next hop before it goes there; or it can create IPSec tunnels and modify routing table entries for the data flow.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116874876","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 : 2002-12-01DOI: 10.1109/GLOCOM.2002.1188505
Ing-Chau Chang, Sheng-Wen Hsieh
An adaptive framework to guarantee the application quality of service (APQoS) of a World Wide Web Consortium (W3C) Synchronized Multimedia Integration Language (SMIL) presentation is proposed. This framework cooperates with underlying network protocol stacks and SMIL client/server applications to guarantee continuous playback without interruption for streaming video and audio objects in the SMIL presentation. The framework at the SMIL client periodically monitors the underlying network bandwidth to calculate if synchronization requirements of the SMIL presentation can be satisfied. If not, the framework first tries dynamically to adjust bandwidth allocations among concurrent SMIL objects, according to their media importance (MI) values, at the SMIL media servers. If this scheme fails, other strategies, such as discarding less important objects or sending lower bit-rate objects instead, are provided. We use the ATM available bit rate (ABR) service to provide adaptive QoS support of network transmission because of its inexpensive cost. In simulations, this framework guarantees that all media data in the SMIL presentation can be shown synchronously.
{"title":"An adaptive QoS guarantee framework for SMIL multimedia presentations with ATM ABR service","authors":"Ing-Chau Chang, Sheng-Wen Hsieh","doi":"10.1109/GLOCOM.2002.1188505","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1188505","url":null,"abstract":"An adaptive framework to guarantee the application quality of service (APQoS) of a World Wide Web Consortium (W3C) Synchronized Multimedia Integration Language (SMIL) presentation is proposed. This framework cooperates with underlying network protocol stacks and SMIL client/server applications to guarantee continuous playback without interruption for streaming video and audio objects in the SMIL presentation. The framework at the SMIL client periodically monitors the underlying network bandwidth to calculate if synchronization requirements of the SMIL presentation can be satisfied. If not, the framework first tries dynamically to adjust bandwidth allocations among concurrent SMIL objects, according to their media importance (MI) values, at the SMIL media servers. If this scheme fails, other strategies, such as discarding less important objects or sending lower bit-rate objects instead, are provided. We use the ATM available bit rate (ABR) service to provide adaptive QoS support of network transmission because of its inexpensive cost. In simulations, this framework guarantees that all media data in the SMIL presentation can be shown synchronously.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122101862","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 : 2002-12-01DOI: 10.1109/GLOCOM.2002.1188548
W. Kuo, Sunil Kumar, C.-C. Jay Kuo
A novel scheduling mechanism and a new bandwidth allocation scheme are proposed in this work to support multimedia traffic over DOCSIS (Data Over Cable System Interface Specification)-compliant cable networks. The primary goal of our research is to improve the transmission of real-time variable bit rate (VBR) traffic in terms of throughput and delay under the current DOCSIS specifications. To support integrated services, we also consider the transmission of constant bit rate (CBR) traffic and non-real-time traffic in the simulation. To demonstrate the performance, we compare the result of the proposed scheme with that of a simple multiple priority scheme. It is shown via simulation that the proposed method provides a significant amount of improvement over existing DOCSIS QoS scheduling services.
{"title":"Bandwidth allocation and traffic scheduling for DOCSIS systems with QoS support","authors":"W. Kuo, Sunil Kumar, C.-C. Jay Kuo","doi":"10.1109/GLOCOM.2002.1188548","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1188548","url":null,"abstract":"A novel scheduling mechanism and a new bandwidth allocation scheme are proposed in this work to support multimedia traffic over DOCSIS (Data Over Cable System Interface Specification)-compliant cable networks. The primary goal of our research is to improve the transmission of real-time variable bit rate (VBR) traffic in terms of throughput and delay under the current DOCSIS specifications. To support integrated services, we also consider the transmission of constant bit rate (CBR) traffic and non-real-time traffic in the simulation. To demonstrate the performance, we compare the result of the proposed scheme with that of a simple multiple priority scheme. It is shown via simulation that the proposed method provides a significant amount of improvement over existing DOCSIS QoS scheduling services.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129173240","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 : 2002-12-01DOI: 10.1109/GLOCOM.2002.1188518
S. Teramoto, T. Ohtsuki
We propose a multiple-subcarrier (MS) optical communication system with subcarrier signal point sequence (SSPS). We use the SSPS having the large minimum value and the large Euclidean distances, so that the required d.c. bias is minimized and the error rate performance is improved. Note that in the proposed systems, the signal points having the larger minimum value are selected, while the signal points having lower peak to mean envelope power ratio (PMEPR) are selected in orthogonal frequency division multiplexing (OFDM) systems. Therefore, the signal point sequences good for OFDM with phase shifting by /spl pi/ radian are not necessarily good ones for MS optical communication systems. We show that the normalized power requirement and normalized bandwidth requirement of the MS-SSPS are smaller than those of the conventional MS systems.
{"title":"Multiple-subcarrier optical communication systems with subcarrier signal point sequence","authors":"S. Teramoto, T. Ohtsuki","doi":"10.1109/GLOCOM.2002.1188518","DOIUrl":"https://doi.org/10.1109/GLOCOM.2002.1188518","url":null,"abstract":"We propose a multiple-subcarrier (MS) optical communication system with subcarrier signal point sequence (SSPS). We use the SSPS having the large minimum value and the large Euclidean distances, so that the required d.c. bias is minimized and the error rate performance is improved. Note that in the proposed systems, the signal points having the larger minimum value are selected, while the signal points having lower peak to mean envelope power ratio (PMEPR) are selected in orthogonal frequency division multiplexing (OFDM) systems. Therefore, the signal point sequences good for OFDM with phase shifting by /spl pi/ radian are not necessarily good ones for MS optical communication systems. We show that the normalized power requirement and normalized bandwidth requirement of the MS-SSPS are smaller than those of the conventional MS systems.","PeriodicalId":415837,"journal":{"name":"Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130464256","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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