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.2009.5068967
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.2009.5068953
J. P. Carvalho, H. Veiga, P. Gomes, C. Pacheco, N. Marques, A. Reis
Experimental laboratory measurements are made about several performance aspects of IEEE 802.11a, b, g point-to-point links, using Enterasys Networks access points (RBTR2). Detailed results are presented and discussed at OSI levels 1, 3, 4 and 7: SNR, latency, ICMP packet loss, TCP throughput, jitter, percentage datagram loss, and FTP transfer rate.
{"title":"Laboratory performance of wi-fi point-to-point links: A case study","authors":"J. P. Carvalho, H. Veiga, P. Gomes, C. Pacheco, N. Marques, A. Reis","doi":"10.1109/WTS.2009.5068953","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068953","url":null,"abstract":"Experimental laboratory measurements are made about several performance aspects of IEEE 802.11a, b, g point-to-point links, using Enterasys Networks access points (RBTR2). Detailed results are presented and discussed at OSI levels 1, 3, 4 and 7: SNR, latency, ICMP packet loss, TCP throughput, jitter, percentage datagram loss, and FTP transfer rate.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"55 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":"115928548","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.2009.5068962
A. Hekkala, M. Lasanen
This paper considers the adaptive predistortion of the nonlinear distortions in a Radio over Fiber (RoF) link. In particular, we modify and compare two adaptive algorithms developed originally for the compensation of the linear systems, namely LMS and variable step size normalized LMS (VS NLMS). A recursive least squares (RLS) solution is used as a reference. Our simulation results indicate that over 40 dB improvement of adjacent channel power ratios can be achieved via the predistortion. Furthermore, we show that in the compensation of the nonlinear RoF link, the LMS can be used in such a way that its performance is comparable to more complex RLS.
{"title":"Performance of adaptive algorithms for compensation of radio over fiber links","authors":"A. Hekkala, M. Lasanen","doi":"10.1109/WTS.2009.5068962","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068962","url":null,"abstract":"This paper considers the adaptive predistortion of the nonlinear distortions in a Radio over Fiber (RoF) link. In particular, we modify and compare two adaptive algorithms developed originally for the compensation of the linear systems, namely LMS and variable step size normalized LMS (VS NLMS). A recursive least squares (RLS) solution is used as a reference. Our simulation results indicate that over 40 dB improvement of adjacent channel power ratios can be achieved via the predistortion. Furthermore, we show that in the compensation of the nonlinear RoF link, the LMS can be used in such a way that its performance is comparable to more complex RLS.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"33 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":"115747274","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.2009.5068976
V. Kumbasar, O. Kucur
In this work, better wavelet packet tree structures are searched to reduce the sum of ISI and ICI powers (integrated power) in Daubechies wavelet-based OFDM system over a practical two path low-voltage powerline channel or two way multipath channel. Better wavelet tree structures are obtained by using a brute-force algorithm. Results show that better wavelet packet tree structures perform better than conventional Mallat structures for the same bandwidth occupancy.
{"title":"Searching better wavelet packet tree for ISI and ICI reduction in WOFDM","authors":"V. Kumbasar, O. Kucur","doi":"10.1109/WTS.2009.5068976","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068976","url":null,"abstract":"In this work, better wavelet packet tree structures are searched to reduce the sum of ISI and ICI powers (integrated power) in Daubechies wavelet-based OFDM system over a practical two path low-voltage powerline channel or two way multipath channel. Better wavelet tree structures are obtained by using a brute-force algorithm. Results show that better wavelet packet tree structures perform better than conventional Mallat structures for the same bandwidth occupancy.","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":"133766962","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.2009.5068952
N. Murad, René Cassin
Energy dissipation in a Wireless Sensor Network is an active research field. Energy dissipation is related to the network topology and protocol used to route data. So, two criteria are proposed to elect a relay. A linear or a random choice from a set of potential nodes to become a relay based on their energy level above a mean threshold energy. These criteria improve the organization of the node communications and the lifetime of the network. The criteria and the protocol called the Self Organization One Hop Low Energy Clustering Adaptation (SOORLECA) are explained. The SOORLECA is designed for environmental and military monitoring with precise requisite measures at each node. No mean data or smoothing data technique is required at the Sink Node (SN). Random topology of the network for 100 nodes over 100m2 are simulated to show the protocol performances compared to direct transmission of the node to the SN, short routing path and static clustering protocols. The lifetime and the dissipated energy of the network are our criteria to measure the performance of the WSN. It is shown that the SOORLECA ACMET1 improves 2x the lifetime of network with 61% dissipated energy after 50% of nodes have dead.
{"title":"Low energy clustering adaptation protocol for an adhoc wireless sensor network","authors":"N. Murad, René Cassin","doi":"10.1109/WTS.2009.5068952","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068952","url":null,"abstract":"Energy dissipation in a Wireless Sensor Network is an active research field. Energy dissipation is related to the network topology and protocol used to route data. So, two criteria are proposed to elect a relay. A linear or a random choice from a set of potential nodes to become a relay based on their energy level above a mean threshold energy. These criteria improve the organization of the node communications and the lifetime of the network. The criteria and the protocol called the Self Organization One Hop Low Energy Clustering Adaptation (SOORLECA) are explained. The SOORLECA is designed for environmental and military monitoring with precise requisite measures at each node. No mean data or smoothing data technique is required at the Sink Node (SN). Random topology of the network for 100 nodes over 100m2 are simulated to show the protocol performances compared to direct transmission of the node to the SN, short routing path and static clustering protocols. The lifetime and the dissipated energy of the network are our criteria to measure the performance of the WSN. It is shown that the SOORLECA ACMET1 improves 2x the lifetime of network with 61% dissipated energy after 50% of nodes have dead.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"25 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":"129724686","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.2009.5068947
Mustafa Taskaldiran, R. Morling, I. Kale
The UMTS turbo encoder is composed of parallel concatenation of two Recursive Systematic Convolutional (RSC) encoders which start and end at a known state. This trellis termination directly affects the performance of turbo codes. This paper presents performance analysis of multi-point trellis termination of turbo codes which is to terminate RSC encoders at more than one point of the current frame while keeping the interleaver length the same. For long interleaver lengths, this approach provides dividing a data frame into sub-frames which can be treated as independent blocks. A novel decoding architecture using multi-point trellis termination and collision-free interleavers is presented. Collision-free interleavers are used to solve memory collision problems encountered by parallel decoding of turbo codes. The proposed parallel decoding architecture reduces the decoding delay caused by the iterative nature and forward-backward metric computations of turbo decoding algorithms. Our simulations verified that this turbo encoding and decoding scheme shows Bit Error Rate (BER) performance very close to that of the UMTS turbo coding while providing almost %50 time saving for the 2-point termination and %80 time saving for the 5-point termination.
{"title":"Parallel decoding of turbo codes using multi-point trellis termination and collision-free interleavers","authors":"Mustafa Taskaldiran, R. Morling, I. Kale","doi":"10.1109/WTS.2009.5068947","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068947","url":null,"abstract":"The UMTS turbo encoder is composed of parallel concatenation of two Recursive Systematic Convolutional (RSC) encoders which start and end at a known state. This trellis termination directly affects the performance of turbo codes. This paper presents performance analysis of multi-point trellis termination of turbo codes which is to terminate RSC encoders at more than one point of the current frame while keeping the interleaver length the same. For long interleaver lengths, this approach provides dividing a data frame into sub-frames which can be treated as independent blocks. A novel decoding architecture using multi-point trellis termination and collision-free interleavers is presented. Collision-free interleavers are used to solve memory collision problems encountered by parallel decoding of turbo codes. The proposed parallel decoding architecture reduces the decoding delay caused by the iterative nature and forward-backward metric computations of turbo decoding algorithms. Our simulations verified that this turbo encoding and decoding scheme shows Bit Error Rate (BER) performance very close to that of the UMTS turbo coding while providing almost %50 time saving for the 2-point termination and %80 time saving for the 5-point termination.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"45 4 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":"116388490","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.2009.5068989
F. Rango
Traditional routing protocols deployed to provide communication among mobile nodes in wireless ad hoc networks (MANET) assume a trust and collaborating environment inside the network. However, this assumption is not always true and a hostile or unprotected environment can seriously affect the protocol and network performance. In this work two kinds of approaches are applied to a well-known routing protocol called SAODV in order to improve its performance and to offer more resilience to attack from malicious nodes authenticated by the network. A preventive approach based on a cryptographic mechanism and a reactive approach to detect the anomalous and malicious behavior of nodes are considered. An extension of SAODV to offer Intrusion Detection mechanism (IDM) and trust-based mechanism (TBM) to promote the collaboration of the cooperating node and penalize the selfish nodes are proposed. The extended and proposed protocol SAODV-SDO is presented and simulation results were performed in order to show the effectiveness of our proposal in comparison with AODV and SAODV.
{"title":"Improving SAODV protocol with trust levels management, IDM and incentive cooperation in MANET","authors":"F. Rango","doi":"10.1109/WTS.2009.5068989","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068989","url":null,"abstract":"Traditional routing protocols deployed to provide communication among mobile nodes in wireless ad hoc networks (MANET) assume a trust and collaborating environment inside the network. However, this assumption is not always true and a hostile or unprotected environment can seriously affect the protocol and network performance. In this work two kinds of approaches are applied to a well-known routing protocol called SAODV in order to improve its performance and to offer more resilience to attack from malicious nodes authenticated by the network. A preventive approach based on a cryptographic mechanism and a reactive approach to detect the anomalous and malicious behavior of nodes are considered. An extension of SAODV to offer Intrusion Detection mechanism (IDM) and trust-based mechanism (TBM) to promote the collaboration of the cooperating node and penalize the selfish nodes are proposed. The extended and proposed protocol SAODV-SDO is presented and simulation results were performed in order to show the effectiveness of our proposal in comparison with AODV and SAODV.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"5 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":"133909172","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.2009.5068948
J. Prieto, A. Bahillo, S. Mazuelas, R. Lorenzo, J. Blas, P. Fernández
An accurate real-time application which locates mobile users in an indoor environment is highly demanded in hospitals, warehouses, etc., provided that minor changes in their infrastructure are required. Most present-day location techniques require a great calibration effort, or special devices which are not cost-effective. Avoiding these needs, this paper implements an autonomous positioning technique based on IEEE 802.11 RTS/CTS two-frame exchange in a real scenario. Two estimators of the delay profile measured are analyzed and a linear regression of them at each distance is performed from which the distance between a mobile user and an access point is estimated. Experimental results, without any tracking information nor nonline-of-sight mitigation, reveal the effectiveness of the proposed method.
{"title":"Adding indoor location capabilities to an IEEE 802.11 WLAN using real-time RTT measurements","authors":"J. Prieto, A. Bahillo, S. Mazuelas, R. Lorenzo, J. Blas, P. Fernández","doi":"10.1109/WTS.2009.5068948","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068948","url":null,"abstract":"An accurate real-time application which locates mobile users in an indoor environment is highly demanded in hospitals, warehouses, etc., provided that minor changes in their infrastructure are required. Most present-day location techniques require a great calibration effort, or special devices which are not cost-effective. Avoiding these needs, this paper implements an autonomous positioning technique based on IEEE 802.11 RTS/CTS two-frame exchange in a real scenario. Two estimators of the delay profile measured are analyzed and a linear regression of them at each distance is performed from which the distance between a mobile user and an access point is estimated. Experimental results, without any tracking information nor nonline-of-sight mitigation, reveal the effectiveness of the proposed method.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"88 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":"134500147","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.2009.5068971
B. Rohani, B. Rohani, M. Caldera, H. Zepernick
A method for in-service monitoring of the end-user perceptual speech quality in cellular radio systems is proposed. This method incorporates the perceptual evaluation of speech quality (PESQ) algorithm to monitor the quality experienced by the end-user. Here, the monitoring is carried out at the transmitting side. In this case, the speech signal received by the end-user is estimated at the transmitter in accordance with a feedback signal. The performance of the proposed scheme has been investigated through extensive simulations for the Universal Mobile Telecommunication System (UMTS) using different speech coding rates and channel conditions. The results indicate that the proposed scheme can predict end-user quality with a root-mean-squared error (RMSE) of at most 0.15 using the mean opinion score (MOS) rating scheme. Such accuracy can be beneficial in applications such as radio resource management for satisfying the desired level of quality of service.
{"title":"On in-service perceptual speech quality monitoring in cellular radio systems","authors":"B. Rohani, B. Rohani, M. Caldera, H. Zepernick","doi":"10.1109/WTS.2009.5068971","DOIUrl":"https://doi.org/10.1109/WTS.2009.5068971","url":null,"abstract":"A method for in-service monitoring of the end-user perceptual speech quality in cellular radio systems is proposed. This method incorporates the perceptual evaluation of speech quality (PESQ) algorithm to monitor the quality experienced by the end-user. Here, the monitoring is carried out at the transmitting side. In this case, the speech signal received by the end-user is estimated at the transmitter in accordance with a feedback signal. The performance of the proposed scheme has been investigated through extensive simulations for the Universal Mobile Telecommunication System (UMTS) using different speech coding rates and channel conditions. The results indicate that the proposed scheme can predict end-user quality with a root-mean-squared error (RMSE) of at most 0.15 using the mean opinion score (MOS) rating scheme. Such accuracy can be beneficial in applications such as radio resource management for satisfying the desired level of quality of service.","PeriodicalId":313087,"journal":{"name":"2009 Wireless Telecommunications Symposium","volume":"270 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":"115792082","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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