Various transmission control protocol (TCP) enhancement schemes have been proposed to improve TCP performance over mixed wired/wireless networks. Among the different kinds of TCP enhancement schemes, end-to-end TCP enhancement schemes have the lowest implementation complexity and do not violate the semantics of TCP. Recently the latest version of Linux (version 2.6.18) has included a popular end-to-end TCP enhancement scheme, TCP Veno, for network communications over wireless networks [13]. This paper is to investigate the performance of the loss differentiation algorithm in Veno over different mixed wired/wireless networks. Simulation results show that the original parameter setting of Veno in [8] is not optimal and the optimal parameter setting is highly affected by the external wireless loss probability.
{"title":"Performance analysis of TCP Veno over mixed wired/wireless networks","authors":"C. Cheung","doi":"10.1109/EW.2008.4623880","DOIUrl":"https://doi.org/10.1109/EW.2008.4623880","url":null,"abstract":"Various transmission control protocol (TCP) enhancement schemes have been proposed to improve TCP performance over mixed wired/wireless networks. Among the different kinds of TCP enhancement schemes, end-to-end TCP enhancement schemes have the lowest implementation complexity and do not violate the semantics of TCP. Recently the latest version of Linux (version 2.6.18) has included a popular end-to-end TCP enhancement scheme, TCP Veno, for network communications over wireless networks [13]. This paper is to investigate the performance of the loss differentiation algorithm in Veno over different mixed wired/wireless networks. Simulation results show that the original parameter setting of Veno in [8] is not optimal and the optimal parameter setting is highly affected by the external wireless loss probability.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"204 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124566268","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}
Low power medium access control (MAC) protocols have received a lot of attention in the last few years because of their impact on the lifetime of wireless sensor networks. Due to the cost of implementation on real hardware, and sometimes to a lack of detail in the description of these protocols, it is difficult to evaluate them. This paper describes the latest advances in the field and introduces an ideal protocol as a benchmark. It presents detailed analytical models of the power consumption of the best and latest low power MAC protocols. These models are then used to evaluate how the performance of these protocols evolves when modifying traffic rate and network density. It is shown that the most recent scheduled protocols cannot go below the maximal acceptable mean power consumption for battery operated sensor networks. The synchronous random access protocols S-MAC and SCP-MAC scale better, but are outperformed by asynchronous random access protocols based on preamble sensing such as WiseMAC, CSMA-MPS, X-MAC and SyncWUF. These last protocols offer the lowest power consumption for all considered data rates and for all considered network densities.
{"title":"Low power medium access control protocols for wireless sensor networks","authors":"J. Rousselot, A. El-Hoiydi, J. Decotignie","doi":"10.1109/EW.2008.4623883","DOIUrl":"https://doi.org/10.1109/EW.2008.4623883","url":null,"abstract":"Low power medium access control (MAC) protocols have received a lot of attention in the last few years because of their impact on the lifetime of wireless sensor networks. Due to the cost of implementation on real hardware, and sometimes to a lack of detail in the description of these protocols, it is difficult to evaluate them. This paper describes the latest advances in the field and introduces an ideal protocol as a benchmark. It presents detailed analytical models of the power consumption of the best and latest low power MAC protocols. These models are then used to evaluate how the performance of these protocols evolves when modifying traffic rate and network density. It is shown that the most recent scheduled protocols cannot go below the maximal acceptable mean power consumption for battery operated sensor networks. The synchronous random access protocols S-MAC and SCP-MAC scale better, but are outperformed by asynchronous random access protocols based on preamble sensing such as WiseMAC, CSMA-MPS, X-MAC and SyncWUF. These last protocols offer the lowest power consumption for all considered data rates and for all considered network densities.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"401 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115908956","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}
In this paper, we make an attempt to integrate the features of scalable video coding (SVC) into current OFDM based mobile communications systems for improving the broadcast data rates and to provide a better coverage. Several physical- and MAC-layer concepts that quality for the use in combination with SVC are evaluated. Space time coding in combination with single carrier frequency division multiplexing (SC-FDM) based on DFT precoding are promising.
{"title":"Scalable video transmission in multiantenna broadcast systems","authors":"S. Jaeckel, V. Jungnickel","doi":"10.1109/EW.2008.4623894","DOIUrl":"https://doi.org/10.1109/EW.2008.4623894","url":null,"abstract":"In this paper, we make an attempt to integrate the features of scalable video coding (SVC) into current OFDM based mobile communications systems for improving the broadcast data rates and to provide a better coverage. Several physical- and MAC-layer concepts that quality for the use in combination with SVC are evaluated. Space time coding in combination with single carrier frequency division multiplexing (SC-FDM) based on DFT precoding are promising.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"268 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114345965","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}
OFDM/OQAM modulation scheme is an alternative to the conventional cyclic-prefix OFDM (CP-OFDM) modulation. It allows a larger theoretical spectral efficiency as it does not require the use of any guard interval. In this paper we investigate and evaluate channel estimation for OFDM/OQAM modulations in multiple-input multiple-output (MIMO) context. We focus on transmission over radio channels and use a two transmit antenna spatial data multiplexing (SDM) scheme. Direct compared in this paper.
{"title":"Channel estimation for iterative MIMO OFDM/OQAM transceivers","authors":"Jean-Philippe Javaudin, Yiqi Jiang","doi":"10.1109/EW.2008.4623886","DOIUrl":"https://doi.org/10.1109/EW.2008.4623886","url":null,"abstract":"OFDM/OQAM modulation scheme is an alternative to the conventional cyclic-prefix OFDM (CP-OFDM) modulation. It allows a larger theoretical spectral efficiency as it does not require the use of any guard interval. In this paper we investigate and evaluate channel estimation for OFDM/OQAM modulations in multiple-input multiple-output (MIMO) context. We focus on transmission over radio channels and use a two transmit antenna spatial data multiplexing (SDM) scheme. Direct compared in this paper.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121844918","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}
A. Krendzel, Marc Portoles-Comeras, J. Mangues‐Bafalluy
This paper presents a methodology to estimate traffic load parameters in WLAN network consisting of a large number of access points (APs). The methodology takes into account the high variability of data traffic throughout the network that APs have to handle and process. It is based on using a low number of initial data formed from known statistical data about behavior of the network. The methodology exploits the inequality in AP popularity along the wireless network to estimate traffic load parameters. It is validated using real WLAN traces of a popular SNMP data collection of Dartmouth College. The methodology provides the traffic load estimations the coincide with the results of actual load measurements when initial input are extracted from everyday real WLAN traces. It also provides appropriate results when some of the initial data for the model are formed by averaging over a certain arbitrary long time period.
{"title":"Methodology for traffic load estimation in WLANs based on real traces","authors":"A. Krendzel, Marc Portoles-Comeras, J. Mangues‐Bafalluy","doi":"10.1109/EW.2008.4623922","DOIUrl":"https://doi.org/10.1109/EW.2008.4623922","url":null,"abstract":"This paper presents a methodology to estimate traffic load parameters in WLAN network consisting of a large number of access points (APs). The methodology takes into account the high variability of data traffic throughout the network that APs have to handle and process. It is based on using a low number of initial data formed from known statistical data about behavior of the network. The methodology exploits the inequality in AP popularity along the wireless network to estimate traffic load parameters. It is validated using real WLAN traces of a popular SNMP data collection of Dartmouth College. The methodology provides the traffic load estimations the coincide with the results of actual load measurements when initial input are extracted from everyday real WLAN traces. It also provides appropriate results when some of the initial data for the model are formed by averaging over a certain arbitrary long time period.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"127 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122111709","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}
Propagation model tuning is a fundamental part of everyday GSM cellular engineering practice. The model tuning is usually accomplished through elaborate and costly tests based on CW measurements. This paper evaluates alternatives to CW testing where measurements are collected using GSM scanners and GSM high dynamic range receivers. The results of the analysis reveal that GSM receivers provide a viable alternative for CW tests in many practical situations. On the other hand, use of GSM scanners is affected by the co-channel and adjacent channel interference and therefore it is limited to cases of relatively low frequency reuse.
{"title":"Use of scanning receivers for RF coverage analysis and propagation model optimization in GSM networks","authors":"N. Mijatovic, I. Kostanic, G. Evans","doi":"10.1109/EW.2008.4623849","DOIUrl":"https://doi.org/10.1109/EW.2008.4623849","url":null,"abstract":"Propagation model tuning is a fundamental part of everyday GSM cellular engineering practice. The model tuning is usually accomplished through elaborate and costly tests based on CW measurements. This paper evaluates alternatives to CW testing where measurements are collected using GSM scanners and GSM high dynamic range receivers. The results of the analysis reveal that GSM receivers provide a viable alternative for CW tests in many practical situations. On the other hand, use of GSM scanners is affected by the co-channel and adjacent channel interference and therefore it is limited to cases of relatively low frequency reuse.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126344360","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}
In this paper, the tail-biting convolutional code (TBCC) performance of the 802.16e Orthogonal Frequency-Division Multiple Access (OFDMA) frame control header (FCH) is studied It is known that the performance and the weight spectrum of a TBCC depend on the paylod size. Therefore, the search for optimal generator polynomials should be done accordingly. In 802.16e, a rate-1/2, memory-6 TBCC that has the best minimum distance and the smalest number of minimum-weight codewords for larger-than-32-bit payloads is used for both FCH and data channels. The data channel has paylod sizes of more than 48 bits; however, the FCH ha smuch shorter paylod sizes (12 and 24 bits). As a result, suboptimal TBCC performance can be expected for FCH. In this paper, we study other options of TBCC generator polynomials for FCH. In addition to available results in the literature, we have found new TBCC generator polynomials according to the optimum distance spectrum criterion. The performance gains in the AWGN channel over the 802.16e TBCC by using the proposed rate-1/4 geenrator polynomials for length-24 and length-12 are about 1dB and 1.2 dB at FER = 10-4, respectively. Also, the performance gains over the 802.16e TBCC by using the proposed rate-1/4 generator polynomials range from 1dB to 3.7dB at FER = 10-3 in multipath Rayleigh fading channels.
{"title":"Improved tail-biting convolutional codes for 802.16e frame control header","authors":"Tsao-Tsen Chen, Shiau-He Tsai","doi":"10.1109/EW.2008.4623840","DOIUrl":"https://doi.org/10.1109/EW.2008.4623840","url":null,"abstract":"In this paper, the tail-biting convolutional code (TBCC) performance of the 802.16e Orthogonal Frequency-Division Multiple Access (OFDMA) frame control header (FCH) is studied It is known that the performance and the weight spectrum of a TBCC depend on the paylod size. Therefore, the search for optimal generator polynomials should be done accordingly. In 802.16e, a rate-1/2, memory-6 TBCC that has the best minimum distance and the smalest number of minimum-weight codewords for larger-than-32-bit payloads is used for both FCH and data channels. The data channel has paylod sizes of more than 48 bits; however, the FCH ha smuch shorter paylod sizes (12 and 24 bits). As a result, suboptimal TBCC performance can be expected for FCH. In this paper, we study other options of TBCC generator polynomials for FCH. In addition to available results in the literature, we have found new TBCC generator polynomials according to the optimum distance spectrum criterion. The performance gains in the AWGN channel over the 802.16e TBCC by using the proposed rate-1/4 geenrator polynomials for length-24 and length-12 are about 1dB and 1.2 dB at FER = 10-4, respectively. Also, the performance gains over the 802.16e TBCC by using the proposed rate-1/4 generator polynomials range from 1dB to 3.7dB at FER = 10-3 in multipath Rayleigh fading channels.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131074588","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}
Kimon Karras, Theodore Kyritsis, M. Amirfeiz, S. Baiotti
Current aeronautical communications are extremely limited by the obsolete ATN standard, which does not allow aircraft to communicate directly with each other. The aeronautical community is already moving to replace the OSI-based ATN with the more efficient and widespread TCP/IP protocols. This paper takes this concept one step further and proposes an innovative architecture based on the TCP/IP protocol stack and Mobile Ad Hoc Networks. The new architecture will allow aircraft to communicate with each other in a dynamic environment, enhance existing services and provide the infrastructure for future ones. A modified protocol stack is proposed that includes an enhanced ad-hoc routing protocol and a mechanism that allows for the dynamic management of terminals in a node. Simulations results are provided that prove that this architecture has the potential to improve future aeronautical communications.
{"title":"Aeronautical Mobile Ad Hoc Networks","authors":"Kimon Karras, Theodore Kyritsis, M. Amirfeiz, S. Baiotti","doi":"10.1109/EW.2008.4623845","DOIUrl":"https://doi.org/10.1109/EW.2008.4623845","url":null,"abstract":"Current aeronautical communications are extremely limited by the obsolete ATN standard, which does not allow aircraft to communicate directly with each other. The aeronautical community is already moving to replace the OSI-based ATN with the more efficient and widespread TCP/IP protocols. This paper takes this concept one step further and proposes an innovative architecture based on the TCP/IP protocol stack and Mobile Ad Hoc Networks. The new architecture will allow aircraft to communicate with each other in a dynamic environment, enhance existing services and provide the infrastructure for future ones. A modified protocol stack is proposed that includes an enhanced ad-hoc routing protocol and a mechanism that allows for the dynamic management of terminals in a node. Simulations results are provided that prove that this architecture has the potential to improve future aeronautical communications.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128222759","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}
Digital video broadcasting for handheld terminals (DVB-H) is assuming an aver growing importance for digital video transmission over wireless terminals In this context, services are transmitted in ldquopacketsrdquo or ldquoburstsrdquo periodically repeating in time and interspaced by ldquooff-timerdquo periods. To improve this time sliced transmission effectiveness, a novel technique, the variable burst time (VET) algorithm, is presented and discussed. It takes into account the multimedia data, the receiving buffer size and the available bandwidth information to adjust the service burst durations and reduce losses. Numerical results show the effectiveness of the proposed technique if compared with the classical TDM transmission technique already known by DVB-H standard specifications.
{"title":"A bandwidth dependent multiservice scheduling algorithm for variable-bit-rate video transmission in DVB-H systems","authors":"P. Camarda, A. Ripa, D. Striccoli","doi":"10.1109/EW.2008.4623861","DOIUrl":"https://doi.org/10.1109/EW.2008.4623861","url":null,"abstract":"Digital video broadcasting for handheld terminals (DVB-H) is assuming an aver growing importance for digital video transmission over wireless terminals In this context, services are transmitted in ldquopacketsrdquo or ldquoburstsrdquo periodically repeating in time and interspaced by ldquooff-timerdquo periods. To improve this time sliced transmission effectiveness, a novel technique, the variable burst time (VET) algorithm, is presented and discussed. It takes into account the multimedia data, the receiving buffer size and the available bandwidth information to adjust the service burst durations and reduce losses. Numerical results show the effectiveness of the proposed technique if compared with the classical TDM transmission technique already known by DVB-H standard specifications.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133679548","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}
Future wireless packet switched cellular networks will require dense frequency reuse to achieve high capacity. At the same time, measures are required which limit the interference on the frequency carriers. It is assumed that central entities performing the task of interference coordination with global knowledge should be avoided. Rather, distributed algorithms are sought for. To this end, we propose decentralized resource allocation algorithms that enable base stations to select a pool of favorable resources with low interference based on local knowledge only. The actual user-level resource allocation from that pool will then be performed by fast schedulers operating on the preselected resources within each cell. We analyze and evaluate the proposed resource selection algorithms by introducing a simplified wireless network model and applying methods from game theory. Proving the existence of Nash equilibria shows that stable resource allocations can be reached by selfish agents. In addition to that, we perform simulations to determine the speed of convergence and the resulting equilibrium interference levels. By comparing these to an optimal global solution, which is derived by solving an integer linear program, we are able to quantify the efficiency loss of the distributed game approach. It turns out that even though the distributed game results are sub-optimal, the low degree of system complexity and the inherent adaptability make the decentralized approach promising especially for dynamic scenarios.
{"title":"Decentralized inter-cell interference coordination by autonomous spectral reuse decisions","authors":"Jan Ellenbeck, C. Hartmann, L. Berlemann","doi":"10.1109/EW.2008.4623915","DOIUrl":"https://doi.org/10.1109/EW.2008.4623915","url":null,"abstract":"Future wireless packet switched cellular networks will require dense frequency reuse to achieve high capacity. At the same time, measures are required which limit the interference on the frequency carriers. It is assumed that central entities performing the task of interference coordination with global knowledge should be avoided. Rather, distributed algorithms are sought for. To this end, we propose decentralized resource allocation algorithms that enable base stations to select a pool of favorable resources with low interference based on local knowledge only. The actual user-level resource allocation from that pool will then be performed by fast schedulers operating on the preselected resources within each cell. We analyze and evaluate the proposed resource selection algorithms by introducing a simplified wireless network model and applying methods from game theory. Proving the existence of Nash equilibria shows that stable resource allocations can be reached by selfish agents. In addition to that, we perform simulations to determine the speed of convergence and the resulting equilibrium interference levels. By comparing these to an optimal global solution, which is derived by solving an integer linear program, we are able to quantify the efficiency loss of the distributed game approach. It turns out that even though the distributed game results are sub-optimal, the low degree of system complexity and the inherent adaptability make the decentralized approach promising especially for dynamic scenarios.","PeriodicalId":237850,"journal":{"name":"2008 14th European Wireless Conference","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123842322","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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