Pub Date : 2005-11-01DOI: 10.1109/GLOCOM.2005.1578021
Belkacem Daheb, G. Pujolle
The present paper presents a framework for managing quality of service in future WDM core optical networks. These networks solve the bandwidth problem but transmit complexity to the control and management layers. Part of this complexity is handled by the generalized multiprotocol label switching (GMPLS) control plane. The latter, however, cannot tackle the new challenges posed by emerging applications requiring more than bandwidth guaranteed connections. In this paper, we first study the requirements of applications and the proposed quality of service in GMPLS, and then, we try to fill up the gap between both, with a focus on the transmission delay. The resulting framework will enable the optical network to meet the exigencies of new services
{"title":"Quality of service routing for service level agreement conformance in optical networks","authors":"Belkacem Daheb, G. Pujolle","doi":"10.1109/GLOCOM.2005.1578021","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1578021","url":null,"abstract":"The present paper presents a framework for managing quality of service in future WDM core optical networks. These networks solve the bandwidth problem but transmit complexity to the control and management layers. Part of this complexity is handled by the generalized multiprotocol label switching (GMPLS) control plane. The latter, however, cannot tackle the new challenges posed by emerging applications requiring more than bandwidth guaranteed connections. In this paper, we first study the requirements of applications and the proposed quality of service in GMPLS, and then, we try to fill up the gap between both, with a focus on the transmission delay. The resulting framework will enable the optical network to meet the exigencies of new services","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127907764","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 : 2005-11-01DOI: 10.1109/GLOCOM.2005.1577690
Min Wang, G. Kuo
This paper proposes an optimized load sharing and distributed streaming system. Because few load sharing and distributed designs among servers are adopted in existing multimedia streaming solutions, the proposed system introduces a new control protocol used between the center server and the proxy servers by which the center server can determine the resource availability of each proxy server. A new load sharing oriented allocation (LSOA) scheme is used to serve the arriving requests according to the resource availability of each proxy. Moreover, a new backup strategy used in proxy servers is designed to enhance the system robustness. Compared to the existing schemes, simulation results show that the performance of the streaming system is improved significantly.
{"title":"Design of an optimized load sharing and multimedia-oriented streaming system","authors":"Min Wang, G. Kuo","doi":"10.1109/GLOCOM.2005.1577690","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1577690","url":null,"abstract":"This paper proposes an optimized load sharing and distributed streaming system. Because few load sharing and distributed designs among servers are adopted in existing multimedia streaming solutions, the proposed system introduces a new control protocol used between the center server and the proxy servers by which the center server can determine the resource availability of each proxy server. A new load sharing oriented allocation (LSOA) scheme is used to serve the arriving requests according to the resource availability of each proxy. Moreover, a new backup strategy used in proxy servers is designed to enhance the system robustness. Compared to the existing schemes, simulation results show that the performance of the streaming system is improved significantly.","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"218 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128948196","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 : 2005-11-01DOI: 10.1109/GLOCOM.2005.1578087
Minho Cheong, Yong-Hwan Lee, H. Park
We consider the crosstalk cancellation problem when the transmit and receive signal spectrum are partially overlapped with each other in the frequency domain. In this case, the use of conventional crosstalk cancellers may not be practical due to the computational complexity. When the overlapped bandwidth of the crosstalk signal is less than the bandwidth of the transmit signal, the crosstalk cancellation can be realized efficiently by processing in the baseband. The use of interpolation and decimation processing in the baseband makes it possible to realize the crosstalk canceller with low computational complexity. The proposed scheme can provide crosstalk cancellation performance comparable to the conventional one, while requiring the computational complexity less than one half the conventional one
{"title":"Computationally efficient cancellation of partially-overlapped crosstalk in digital subscriber lines","authors":"Minho Cheong, Yong-Hwan Lee, H. Park","doi":"10.1109/GLOCOM.2005.1578087","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1578087","url":null,"abstract":"We consider the crosstalk cancellation problem when the transmit and receive signal spectrum are partially overlapped with each other in the frequency domain. In this case, the use of conventional crosstalk cancellers may not be practical due to the computational complexity. When the overlapped bandwidth of the crosstalk signal is less than the bandwidth of the transmit signal, the crosstalk cancellation can be realized efficiently by processing in the baseband. The use of interpolation and decimation processing in the baseband makes it possible to realize the crosstalk canceller with low computational complexity. The proposed scheme can provide crosstalk cancellation performance comparable to the conventional one, while requiring the computational complexity less than one half the conventional one","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116618357","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 : 2005-11-01DOI: 10.1109/GLOCOM.2005.1577381
I. Cosovic, S. Brandes, M. Schnell
In this paper, a new technique for sidelobe suppression in orthogonal frequency-division multiplexing (OFDM) systems is proposed and investigated. This technique can be applied to both pure OFDM and OFDM based multiple-access systems to improve spectral efficiency. Moreover, it can be utilized within OFDM based overlay systems to avoid interference towards the legacy systems operating in the same frequency band as the overlay system. The proposed sidelobe suppression technique is based on subcarrier weighting. The real-valued subcarrier weights are determined in such a way that the sidelobes of the transmission signal are minimized using an optimization algorithm which is capable to take several optimization constraints into account. Results show that sidelobes can be easily suppressed by more than 10 dB with the proposed technique. These results are achieved by allowing only a moderate loss in bit-error rate performance.
{"title":"A technique for sidelobe suppression in OFDM systems","authors":"I. Cosovic, S. Brandes, M. Schnell","doi":"10.1109/GLOCOM.2005.1577381","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1577381","url":null,"abstract":"In this paper, a new technique for sidelobe suppression in orthogonal frequency-division multiplexing (OFDM) systems is proposed and investigated. This technique can be applied to both pure OFDM and OFDM based multiple-access systems to improve spectral efficiency. Moreover, it can be utilized within OFDM based overlay systems to avoid interference towards the legacy systems operating in the same frequency band as the overlay system. The proposed sidelobe suppression technique is based on subcarrier weighting. The real-valued subcarrier weights are determined in such a way that the sidelobes of the transmission signal are minimized using an optimization algorithm which is capable to take several optimization constraints into account. Results show that sidelobes can be easily suppressed by more than 10 dB with the proposed technique. These results are achieved by allowing only a moderate loss in bit-error rate performance.","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130032803","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 : 2005-11-01DOI: 10.1109/GLOCOM.2005.1577661
K. Haddadou, S. Ghamri-Doudane, Y. Ghamri-Doudane, N. Agoulmine
In this paper we present a complete analysis of dynamic resource allocation in policy-enabled networks. This analysis is carried out throughout both practical and analytical evaluations. Firstly, we present the details of our dynamic resource allocation architecture based on the policy-based management framework. Then, we evaluate, through extensive experimentations on a developed test-bed, the scalability of such architecture in a real environment. Finally, we develop an analytical model for the proposed architecture. This analytical evaluation allows us to confirm our practical analysis and to identify the weakness of such architectures
{"title":"On scalability of dynamic resource allocation in policy-enabled networks: practical and analytical evaluations","authors":"K. Haddadou, S. Ghamri-Doudane, Y. Ghamri-Doudane, N. Agoulmine","doi":"10.1109/GLOCOM.2005.1577661","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1577661","url":null,"abstract":"In this paper we present a complete analysis of dynamic resource allocation in policy-enabled networks. This analysis is carried out throughout both practical and analytical evaluations. Firstly, we present the details of our dynamic resource allocation architecture based on the policy-based management framework. Then, we evaluate, through extensive experimentations on a developed test-bed, the scalability of such architecture in a real environment. Finally, we develop an analytical model for the proposed architecture. This analytical evaluation allows us to confirm our practical analysis and to identify the weakness of such architectures","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114627766","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 : 2005-11-01DOI: 10.1109/GLOCOM.2005.1577373
Bosheng Zhou, A. Marshall, Tsung-Han Lee
Provision of an efficient communication infrastructure is a critical task for wireless sensor networks, and Virtual backbones have been proposed as an efficient mechanism for providing this. In this paper, we propose an energy-aware virtual backbone tree (EVBT) for general-purpose communications in wireless sensor networks. The EVBT has some salient features: the overhead for constructing an EVBT is very low; the delivery of data along the tree depletes minimum energy from the network; and the tree nodes are those with high energy levels. In addition to these, the proposed algorithm is adaptive in nature - it automatically adapts to the addition and removal of the sensor nodes. The use of multiple EVBTs improves the robustness of the communications infrastructure. Simulation results are presented that demonstrate the efficiency of the proposed algorithm.
{"title":"An energy-aware virtual backbone tree for wireless sensor networks","authors":"Bosheng Zhou, A. Marshall, Tsung-Han Lee","doi":"10.1109/GLOCOM.2005.1577373","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1577373","url":null,"abstract":"Provision of an efficient communication infrastructure is a critical task for wireless sensor networks, and Virtual backbones have been proposed as an efficient mechanism for providing this. In this paper, we propose an energy-aware virtual backbone tree (EVBT) for general-purpose communications in wireless sensor networks. The EVBT has some salient features: the overhead for constructing an EVBT is very low; the delivery of data along the tree depletes minimum energy from the network; and the tree nodes are those with high energy levels. In addition to these, the proposed algorithm is adaptive in nature - it automatically adapts to the addition and removal of the sensor nodes. The use of multiple EVBTs improves the robustness of the communications infrastructure. Simulation results are presented that demonstrate the efficiency of the proposed algorithm.","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"118 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116359116","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 : 2005-11-01DOI: 10.1109/GLOCOM.2005.1577784
M. Barbera, A. Lombardo, G. Schembra, M. Tribastone
BitTorrent is today one of the largest P2P systems which allows file sharing for Internet users. Very little effort has been dedicated to this target up to now. The goal of this paper is to develop an analytical model of a free-rider in a BitTorrent network. Unlike previous analytical models which capture the behavior of the network as a whole, the proposed model is able to analyze the performance from the user perspective. The model is applied to a case study to evaluate performance in a real case, and to obtain some insights into the influence of BitTorrent parameters on system performance.
{"title":"A Markov model of a freerider in a BitTorrent P2P network","authors":"M. Barbera, A. Lombardo, G. Schembra, M. Tribastone","doi":"10.1109/GLOCOM.2005.1577784","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1577784","url":null,"abstract":"BitTorrent is today one of the largest P2P systems which allows file sharing for Internet users. Very little effort has been dedicated to this target up to now. The goal of this paper is to develop an analytical model of a free-rider in a BitTorrent network. Unlike previous analytical models which capture the behavior of the network as a whole, the proposed model is able to analyze the performance from the user perspective. The model is applied to a case study to evaluate performance in a real case, and to obtain some insights into the influence of BitTorrent parameters on system performance.","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121038327","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 : 2005-11-01DOI: 10.1109/GLOCOM.2005.1578063
M. Sandell, J. Coon
In MIMO OFDM systems, the quality of channel estimation becomes important, especially for a large number of antennas. On the other hand, it is desirable to minimise the overhead, making the design of training sequences a crucial task. Although this problem has been solved efficiently for OFDM systems using all subcarriers, it is still an open question for systems with nulled subcarriers (such as IEEE802.11a and IEEE802.11n), where some of the subcarriers are left unmodulated in order to fit specified spectrum masks. In this paper we present a numerical method for designing MIMO OFDM training sequences for arbitrary systems using nulled subcarriers. It is shown that substantial gains can be had over simple training sequences, such as only transmitting on non-overlapping subcarriers. The performance of these new training sequences are measured in both mean-squared error and bit-error rate
{"title":"Near-optimal training sequences for MIMO OFDM systems with nulled subcarriers","authors":"M. Sandell, J. Coon","doi":"10.1109/GLOCOM.2005.1578063","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1578063","url":null,"abstract":"In MIMO OFDM systems, the quality of channel estimation becomes important, especially for a large number of antennas. On the other hand, it is desirable to minimise the overhead, making the design of training sequences a crucial task. Although this problem has been solved efficiently for OFDM systems using all subcarriers, it is still an open question for systems with nulled subcarriers (such as IEEE802.11a and IEEE802.11n), where some of the subcarriers are left unmodulated in order to fit specified spectrum masks. In this paper we present a numerical method for designing MIMO OFDM training sequences for arbitrary systems using nulled subcarriers. It is shown that substantial gains can be had over simple training sequences, such as only transmitting on non-overlapping subcarriers. The performance of these new training sequences are measured in both mean-squared error and bit-error rate","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121956521","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 : 2005-11-01DOI: 10.1109/GLOCOM.2005.1578366
L. Sanguinetti, M. Morelli, I. Cosovic
We consider the downlink of a multi-carrier code-division multiple-access (MC-CDMA) system operating in a time division duplexing (TDD) mode and propose a non-linear pre-filtering scheme based on Tomlinson-Harashima pre-coding. In designing the pre-filtering matrices we adopt a minimum mean square error (MMSE) approach under a constraint on the overall transmit power since multiple access interference and multipath distortions are pre-compensated at the base station, low-complex receivers can be employed at the mobile units. Compared to other existing solutions, the proposed scheme provides better error rate performance
{"title":"Pre-filtering techniques for MC-CDMA downlink transmissions","authors":"L. Sanguinetti, M. Morelli, I. Cosovic","doi":"10.1109/GLOCOM.2005.1578366","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1578366","url":null,"abstract":"We consider the downlink of a multi-carrier code-division multiple-access (MC-CDMA) system operating in a time division duplexing (TDD) mode and propose a non-linear pre-filtering scheme based on Tomlinson-Harashima pre-coding. In designing the pre-filtering matrices we adopt a minimum mean square error (MMSE) approach under a constraint on the overall transmit power since multiple access interference and multipath distortions are pre-compensated at the base station, low-complex receivers can be employed at the mobile units. Compared to other existing solutions, the proposed scheme provides better error rate performance","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124931691","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 : 2005-11-01DOI: 10.1109/GLOCOM.2005.1578338
F. Horlin, Eduardo Lopez-Estraviz, L. Perre
Single-carrier code division multiple access (SC-CDMA), also named cyclic-prefix CDMA in the literature, is a promising air interface for the uplink of the 4G cellular wireless communication systems. It enables the high capacity intrinsically offered by CDMA by making the equalization of the multipath channels and the mitigation of the resulting interference possible at a low complexity. This paper proposes a new air interface that combines SC-CDMA with space time block coding (STBC) across multiple transmit antennas in order to robustify the link. Contrary to existing air interfaces that perform the STBC encoding at the chip level, making them only applicable to the downlink, the STBC encoding is performed at the symbol level, making it also applicable to the uplink. In order to optimally detect the antenna and user signals, a joint detector optimized according to the minimum mean square error (MMSE) criterion is designed. By exploiting the cyclo-stationarity of the channels, the complexity of the joint detector is significantly reduced. It is analytically shown that the inter-antenna interference is canceled out at the output of the first stage of the linear MMSE joint detector, consisting of a matched filter. Assuming typical outdoor channels, a gain of 4 dB signal-to-noise-ratio (SNR) is achieved by the use of two transmit antennas over the single antenna system
{"title":"STBC for uplink single-carrier CDMA with equalization in the frequency domain","authors":"F. Horlin, Eduardo Lopez-Estraviz, L. Perre","doi":"10.1109/GLOCOM.2005.1578338","DOIUrl":"https://doi.org/10.1109/GLOCOM.2005.1578338","url":null,"abstract":"Single-carrier code division multiple access (SC-CDMA), also named cyclic-prefix CDMA in the literature, is a promising air interface for the uplink of the 4G cellular wireless communication systems. It enables the high capacity intrinsically offered by CDMA by making the equalization of the multipath channels and the mitigation of the resulting interference possible at a low complexity. This paper proposes a new air interface that combines SC-CDMA with space time block coding (STBC) across multiple transmit antennas in order to robustify the link. Contrary to existing air interfaces that perform the STBC encoding at the chip level, making them only applicable to the downlink, the STBC encoding is performed at the symbol level, making it also applicable to the uplink. In order to optimally detect the antenna and user signals, a joint detector optimized according to the minimum mean square error (MMSE) criterion is designed. By exploiting the cyclo-stationarity of the channels, the complexity of the joint detector is significantly reduced. It is analytically shown that the inter-antenna interference is canceled out at the output of the first stage of the linear MMSE joint detector, consisting of a matched filter. Assuming typical outdoor channels, a gain of 4 dB signal-to-noise-ratio (SNR) is achieved by the use of two transmit antennas over the single antenna system","PeriodicalId":319736,"journal":{"name":"GLOBECOM '05. IEEE Global Telecommunications Conference, 2005.","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124812484","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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