Pub Date : 2009-04-22DOI: 10.1109/WTS.2009.5068974
V. Kumbasar, O. Kucur
In this work, we examined the performance of conventional DFT based OFDM and wavelet based OFDM (WOFDM) with and without Alamouti coding over multipath Rayleigh fading channels with exponential power delay profile. Results show that WOFDM has slightly better bit error rate performance than the conventional OFDM with and without Alamouti code. Besides the performance improvement of WOFDM as compared to conventional OFDM, increases by the use of Alamouti coding. In addition to having better performance, WOFDM might be an alternative to conventional OFDM since it has better bandwidth efficiency.
{"title":"Alamouti coded wavelet based OFDM for multipath fading channels","authors":"V. Kumbasar, O. Kucur","doi":"10.1109/WTS.2009.5068974","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068974","url":null,"abstract":"In this work, we examined the performance of conventional DFT based OFDM and wavelet based OFDM (WOFDM) with and without Alamouti coding over multipath Rayleigh fading channels with exponential power delay profile. Results show that WOFDM has slightly better bit error rate performance than the conventional OFDM with and without Alamouti code. Besides the performance improvement of WOFDM as compared to conventional OFDM, increases by the use of Alamouti coding. In addition to having better performance, WOFDM might be an alternative to conventional OFDM since it has better bandwidth efficiency.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128075277","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 : 2009-04-22DOI: 10.1109/WTS.2009.5068945
A. Zavabeti, M. Sarvi
In heavy traffic cellular networks low priority handover requests will increase handover drops. In current handover queuing schemes, slow signal strength changing mobile units with low priority handover requests can occupy the handover queue space. As a result, high priority requests will be dropped. This effect could be eliminated utilizing a new scheme called Comparative Queuing. Prioritization method has been modified to include the possibility of termination of calls for the mobile units waiting in the handover queue. This scheme with lower queue sizes outperforms the existing dynamic priority queuing schemes under heavy traffic conditions. Simulation is conducted for a cluster of seven cells to incorporate interaction between cells. Simulation results confirm the reduction in handover drops.
{"title":"Reducing handover drops by utilizing Comparative Queuing","authors":"A. Zavabeti, M. Sarvi","doi":"10.1109/WTS.2009.5068945","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068945","url":null,"abstract":"In heavy traffic cellular networks low priority handover requests will increase handover drops. In current handover queuing schemes, slow signal strength changing mobile units with low priority handover requests can occupy the handover queue space. As a result, high priority requests will be dropped. This effect could be eliminated utilizing a new scheme called Comparative Queuing. Prioritization method has been modified to include the possibility of termination of calls for the mobile units waiting in the handover queue. This scheme with lower queue sizes outperforms the existing dynamic priority queuing schemes under heavy traffic conditions. Simulation is conducted for a cluster of seven cells to incorporate interaction between cells. Simulation results confirm the reduction in handover drops.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133683756","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 : 2009-04-22DOI: 10.1109/WTS.2009.5068938
S. Prahmkaew
The Digital Video Broadcasting Return Channel via Satellite (DVB-RCS) is a flexible technology offering broadband Internet access to a large community of users with a relative low cost. However, the spreading of the multimedia network is required the mechanism to guarantee a certain level of Quality of Service (QoS) to the end users. This paper will propose the ARC mechanism which is acting like a gate to control bandwidth by investigating the available channel parameter, and delay time for reused the other available channels at Network Communication Center (NCC). The other co-parameters such as number of packet drop, mean queue time and throughput are investigated in situation of congestion. The results of ARC mechanism will compare with regular mechanism, as Connection Admission Control (CAC) mechanisms. Finally we obtained the impressive results over the proposed mechanism.
{"title":"Adaptive rate control (ARC) over DVB-RCS on satellite links","authors":"S. Prahmkaew","doi":"10.1109/WTS.2009.5068938","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068938","url":null,"abstract":"The Digital Video Broadcasting Return Channel via Satellite (DVB-RCS) is a flexible technology offering broadband Internet access to a large community of users with a relative low cost. However, the spreading of the multimedia network is required the mechanism to guarantee a certain level of Quality of Service (QoS) to the end users. This paper will propose the ARC mechanism which is acting like a gate to control bandwidth by investigating the available channel parameter, and delay time for reused the other available channels at Network Communication Center (NCC). The other co-parameters such as number of packet drop, mean queue time and throughput are investigated in situation of congestion. The results of ARC mechanism will compare with regular mechanism, as Connection Admission Control (CAC) mechanisms. Finally we obtained the impressive results over the proposed mechanism.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133039261","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 : 2009-04-22DOI: 10.1109/WTS.2009.5068991
B. Khoo, P. Harris, S. A. Husain
Most of the sources of security and privacy issues in RFID technology arise from the violation of the air interface between a tag and its reader. This paper will approach the security risk analysis process from the perspective of the RFID tag life cycle, identify the tag usage processes, identify the associated vulnerability and threat to the confidentiality, integrity and availability of the information assets and its implications for privacy, and then mitigate the risks.
{"title":"Security risk analysis of RFID technology: A RFID tag life cycle approach","authors":"B. Khoo, P. Harris, S. A. Husain","doi":"10.1109/WTS.2009.5068991","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068991","url":null,"abstract":"Most of the sources of security and privacy issues in RFID technology arise from the violation of the air interface between a tag and its reader. This paper will approach the security risk analysis process from the perspective of the RFID tag life cycle, identify the tag usage processes, identify the associated vulnerability and threat to the confidentiality, integrity and availability of the information assets and its implications for privacy, and then mitigate the risks.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115650011","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 : 2009-04-22DOI: 10.1109/WTS.2009.5068977
Young-Suk Kim, Joon-Woo Lee, Seongrae Park, ByoungCheol Choi
In this paper, we present mobile advertisement system(MAS) using data push scheduling scheme based on user's content preference model. To schedule advertising operation effectively, we analyzed user's preference of content over time. The result of analysis shows consistent characteristics. And result is applied to build preference model for ad content selection at a given time. Using user preference model, service enabler supports push message scheduling for ad content in systematic manner. Also, to show how to cope with the spamming issue of push based advertisement, push message filtering is introduced to minimize the risk of implicit spamming. As experimental result, we show simulation result of data push scheduling scheme for 7 ad contents, which is resulted from user's preference, and prototype of mobile widget application facilitating proposed advertising service scenario. Widget application supports advertisement choice function with respect to the pre-set configuration and services advertising information matched to user's intention.
{"title":"Mobile advertisement system using data push scheduling based on user preference","authors":"Young-Suk Kim, Joon-Woo Lee, Seongrae Park, ByoungCheol Choi","doi":"10.1109/WTS.2009.5068977","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068977","url":null,"abstract":"In this paper, we present mobile advertisement system(MAS) using data push scheduling scheme based on user's content preference model. To schedule advertising operation effectively, we analyzed user's preference of content over time. The result of analysis shows consistent characteristics. And result is applied to build preference model for ad content selection at a given time. Using user preference model, service enabler supports push message scheduling for ad content in systematic manner. Also, to show how to cope with the spamming issue of push based advertisement, push message filtering is introduced to minimize the risk of implicit spamming. As experimental result, we show simulation result of data push scheduling scheme for 7 ad contents, which is resulted from user's preference, and prototype of mobile widget application facilitating proposed advertising service scenario. Widget application supports advertisement choice function with respect to the pre-set configuration and services advertising information matched to user's intention.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131320354","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 : 2009-04-22DOI: 10.1109/WTS.2009.5068999
Steven R. Powell
Companies can benefit from diversifying internationally. This paper analyzes the internationalization efforts of four major European wireless telecommunications service providers: Telefonica, Deutsche Telekom, France Telecom, and Vodafone. Although the four companies have all invested heavily in foreign markets, their internationalization paths have not been the same, resulting in market portfolios with different characteristics. Utilizing a proportionate customer weighting scheme the paper examines how some key aggregate growth, profitability, and risk characteristics of the companies' foreign market portfolios compared in 2007, and how these characteristics changed from 2002 to 2007.
{"title":"On the internationalization of European wireless telecommunications service providers","authors":"Steven R. Powell","doi":"10.1109/WTS.2009.5068999","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068999","url":null,"abstract":"Companies can benefit from diversifying internationally. This paper analyzes the internationalization efforts of four major European wireless telecommunications service providers: Telefonica, Deutsche Telekom, France Telecom, and Vodafone. Although the four companies have all invested heavily in foreign markets, their internationalization paths have not been the same, resulting in market portfolios with different characteristics. Utilizing a proportionate customer weighting scheme the paper examines how some key aggregate growth, profitability, and risk characteristics of the companies' foreign market portfolios compared in 2007, and how these characteristics changed from 2002 to 2007.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128855504","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 : 2009-04-22DOI: 10.1109/WTS.2009.5068967
M. Al-Rawi, R. Jäntti, J. Torsner, M. Sågfors
In this paper we propose a heuristic inter-cell coordination scheme for scheduling users in an opportunistic multi-cell network. The scheme is mainly designed to be implemented in the uplink of networks that utilize the Third Generation Partnership Project Long Term Evolution (3GPP LTE) technology. The objective of the scheme is to coordinate the uplink transmission in neighboring cells such that inter-cell interference is mitigated and the aggregate utility of the mobile users is maximized. In addition to the heuristic approach we formulate the inter-cell scheduling coordination as an integer programming problem. While the optimal solution cannot be realized in practice due to the computational complexity, it provides good insights of how well different algorithms perform. Numerical results show that the proposed coordination method delivers near-optimal performance in the exemplified cases.
{"title":"Channel-aware inter-cell interference coordination for the uplink of 3G LTE networks","authors":"M. Al-Rawi, R. Jäntti, J. Torsner, M. Sågfors","doi":"10.1109/WTS.2009.5068967","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068967","url":null,"abstract":"In this paper we propose a heuristic inter-cell coordination scheme for scheduling users in an opportunistic multi-cell network. The scheme is mainly designed to be implemented in the uplink of networks that utilize the Third Generation Partnership Project Long Term Evolution (3GPP LTE) technology. The objective of the scheme is to coordinate the uplink transmission in neighboring cells such that inter-cell interference is mitigated and the aggregate utility of the mobile users is maximized. In addition to the heuristic approach we formulate the inter-cell scheduling coordination as an integer programming problem. While the optimal solution cannot be realized in practice due to the computational complexity, it provides good insights of how well different algorithms perform. Numerical results show that the proposed coordination method delivers near-optimal performance in the exemplified cases.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127678642","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 : 2009-04-22DOI: 10.1109/WTS.2009.5068930
T. Iliev, I. Lokshina, D. Radev
In this paper, we consider turbo codes that are now introduced in various international standards, including the UMTS standard for third generation personal communications and the ETSI DVB-T standard for Terrestrial Digital Video Broadcasting, and review the method of extrinsic information transfer. The convergence properties of the iterative decoding process associated with a given turbo-coding scheme are assessed using the so-called extrinsic information transfer (EXIT) chart analysis technique. This approach provides an opportunity to foresee the bit error rate (BER) of a turbo code system using only the EXIT chart. It is shown that EXIT charts are powerful tools to analyze and optimize the convergence behavior of iterative systems utilizing the turbo principle, i.e., systems exchanging and refining extrinsic information. The idea is to consider the associated SISO stages as information processors that map input a priori LLR's onto output extrinsic LLR's, the information content being obviously assumed to increase from input to output, and introduce them to the design of turbo systems without the reliance on extensive simulation. Compared with existing methods for generating EXIT functions, a suggested approach provides insight into the iterative behavior of linear turbo systems with substantial reduction in numerical complexity.
{"title":"Use of extrinsic information transfer chart to predict behavior of turbo codes","authors":"T. Iliev, I. Lokshina, D. Radev","doi":"10.1109/WTS.2009.5068930","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068930","url":null,"abstract":"In this paper, we consider turbo codes that are now introduced in various international standards, including the UMTS standard for third generation personal communications and the ETSI DVB-T standard for Terrestrial Digital Video Broadcasting, and review the method of extrinsic information transfer. The convergence properties of the iterative decoding process associated with a given turbo-coding scheme are assessed using the so-called extrinsic information transfer (EXIT) chart analysis technique. This approach provides an opportunity to foresee the bit error rate (BER) of a turbo code system using only the EXIT chart. It is shown that EXIT charts are powerful tools to analyze and optimize the convergence behavior of iterative systems utilizing the turbo principle, i.e., systems exchanging and refining extrinsic information. The idea is to consider the associated SISO stages as information processors that map input a priori LLR's onto output extrinsic LLR's, the information content being obviously assumed to increase from input to output, and introduce them to the design of turbo systems without the reliance on extensive simulation. Compared with existing methods for generating EXIT functions, a suggested approach provides insight into the iterative behavior of linear turbo systems with substantial reduction in numerical complexity.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126873191","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 : 2009-04-22DOI: 10.1109/WTS.2009.5068961
Jilong Li, Jangkyu Yun, Jeongbae Yun, Keuchul Cho, K. Han
In expanded service area of wireless mesh network to support mobility of the mobile station research is recognized as an important issue. Due to the mobile station move frequently to changing the path, data loss and network performance degradation are often occur, such as the service broken. In the existing research of support mobility, the Layer 3 or mobility is required, but it may cause the backup server overhead. This paper is based the 802.11s, the proposed scheme supports station mobility without any additional elements by using Layer 2.
{"title":"Path management scheme to support mobile station in wireless mesh networks for U-healthcare applications","authors":"Jilong Li, Jangkyu Yun, Jeongbae Yun, Keuchul Cho, K. Han","doi":"10.1109/WTS.2009.5068961","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068961","url":null,"abstract":"In expanded service area of wireless mesh network to support mobility of the mobile station research is recognized as an important issue. Due to the mobile station move frequently to changing the path, data loss and network performance degradation are often occur, such as the service broken. In the existing research of support mobility, the Layer 3 or mobility is required, but it may cause the backup server overhead. This paper is based the 802.11s, the proposed scheme supports station mobility without any additional elements by using Layer 2.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133578356","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 : 2009-04-22DOI: 10.1109/WTS.2009.5068970
Elmahdi Driouch, W. Ajib
In multiuser CDMA wireless systems where the base station is equipped with multiple antennas, the base station takes advantage from the spatial and code separability between the served users in order to enhance the performance of the system. However, this enhancement is constrained by the design of an appropriate scheduling scheme which is responsible of choosing the best users to serve. In this paper, we propose efficient scheduling algorithms for the downlink of multiantenna CDMA wireless systems using zero forcing beamforming. Our proposition maximizes the system sum rate and keeps the computational complexity low. We make use of a graph theoretical approach to represent the system as an undirected weighted graph. As a second step, we formulate the scheduling problem as the maximum weight k-colorable subgraph problem. We propose two heuristic solutions to find the users to serve in each time slot in an acceptable polynomial time. Finally we evaluate the efficiency of the proposed schemes by mean of simulations and the results show the near-optimal performance of the proposed schedulers with very low computational complexity compared to the optimal exhaustive search over all the possible users combinaisons.
{"title":"An efficient multiuser scheduling scheme for MIMO-CDMA wireless systems","authors":"Elmahdi Driouch, W. Ajib","doi":"10.1109/WTS.2009.5068970","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068970","url":null,"abstract":"In multiuser CDMA wireless systems where the base station is equipped with multiple antennas, the base station takes advantage from the spatial and code separability between the served users in order to enhance the performance of the system. However, this enhancement is constrained by the design of an appropriate scheduling scheme which is responsible of choosing the best users to serve. In this paper, we propose efficient scheduling algorithms for the downlink of multiantenna CDMA wireless systems using zero forcing beamforming. Our proposition maximizes the system sum rate and keeps the computational complexity low. We make use of a graph theoretical approach to represent the system as an undirected weighted graph. As a second step, we formulate the scheduling problem as the maximum weight k-colorable subgraph problem. We propose two heuristic solutions to find the users to serve in each time slot in an acceptable polynomial time. Finally we evaluate the efficiency of the proposed schemes by mean of simulations and the results show the near-optimal performance of the proposed schedulers with very low computational complexity compared to the optimal exhaustive search over all the possible users combinaisons.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"33 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116888897","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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