{"title":"Video streaming over wireless networks","authors":"Z. Naor","doi":"10.1109/SARNOF.2007.4567349","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567349","url":null,"abstract":"A scheme that exploits the broadcast nature of the wireless communication in order to achieve multicast content delivery is presented in this paper. As opposed to broadcasting, this method enables the clients to determine on-line the delivered content, and thus preserves the advantages of an individual service. On the other hand, a multicast content delivery is much more efficient than a unicast content distribution, which must use a dedicated data channel per each and every client. This method is particularly suitable for sessions having a long time duration, for applications in which clients can subscribe to ahead of time, and for applications in which the clients receive the same information simultaneously. Examples for such applications are live video streaming, near video on demand service, gaming applications, and download requests for popular video files. A multicast content distribution increases the network service throughput in terms of the expected number of clients served simultaneously. Consequently, at highly loaded time periods it offers a reduced waiting time for content delivery.","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127964408","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}
{"title":"Dynamic reflection of RF signals from fluorescent lights: Their spectral analysis and effects on backscattered RFID tag signals","authors":"G. Ibrahim, J. Sensening, T. Al-Mahdawi","doi":"10.1109/SARNOF.2007.4567309","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567309","url":null,"abstract":"Radio frequency (RF) energy reflected from active power line ballast driven fluorescent tubes are known to be modulated at twice the line frequency. When the lamps are driven by electronic ballasts, it is found that the reflected (backscattered) RF wave is amplitude modulated with sidebands located at multiples of electronic ballast frequency components, extending to hundreds of kilohertz with significant power levels spread within this range. Detailed analysis of the measured sidebands spectrum indicated that the sidebands themselves are modulated at multiples of twice the power line frequency. Fluorescent lamps driven by different types of electronic ballasts operating at different unsynchronized frequencies exhibited different power levels. Consequently in an environment with abundance of active fluorescent lamps, the reflected RF signals can significantly affect the reception of modulated backscattered transponder RFID signals at UHF and higher bands.","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130746668","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}
{"title":"A new full-rate full-diversity STBC for 2 TX with low complexity ML decoding","authors":"P. Rabiei, N. Al-Dhahir","doi":"10.1109/SARNOF.2007.4567356","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567356","url":null,"abstract":"A new construction of a full-diversity full-rate space-time block code (FDFR-STBC) is presented in this paper. The design is for 2 transmit antennas and 2 time slots. The code outperforms the previous FDFR-STBC codes in [3], [4], [5], [6] for 1 receive antenna. We reduce the decoding complexity by exploiting the algebraic structure of the code and using the hybrid maximum-likelihood interference cancellation (HMLIC) decoding algorithm and show that it achieves optimum ML performance. Finally, we study the performance of our proposed code over 2 times 2 multi-input multi-output (MIMO) channels and show that it outperforms the Alamouti code for all signal-to-noise ratios (SNR).","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116656559","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}
{"title":"Comparison of time and frequency domain single and double differential schemes for OFDM UWB systems","authors":"S. Islam, N. Al-Dhahir, H. Minn, Sili Lu","doi":"10.1109/SARNOF.2007.4567327","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567327","url":null,"abstract":"Ultra-wideband (UWB) systems possess several distinct features such as very high data rate, large multipath or frequency diversity and improved ranging precision while requiring low-power low-complexity transceivers. Among the different modulation schemes, differential PSK is an attractive option because it does not require channel estimation, and hence reduces implementation complexity. This paper investigates an OFDM UWB receiver based on both time and frequency-domain differential PSK modulation and compares the performances of single and double differential schemes in the presence of frequency offset.","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124059158","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}
{"title":"Path computation element (PCE)-based traffic engineering in MPLS and GMPLS networks","authors":"E. Oki, I. Inoue, K. Shiomoto","doi":"10.1109/SARNOF.2007.4567400","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567400","url":null,"abstract":"This paper describes a new path computation model in Multi-protocol Label Switching (MPLS) and Generalized MPLS (GMPLS) networks. It introduces a path computation element (PCE), which is functionally separate from label switching routers (LSRs). The Path Computation Element (PCE) is an entity that is capable of computing a network path or route based on a network graph, and applying computational constraints. It is applied to intra-area, inter-area, inter-AS, and inter-layer traffic engineering. Then, we describes an PCE-based inter-layer traffic engineering framework. Inter-layer traffic engineering optimizes network resource utilization globally, i.e. taking into account all layers, rather than optimizing resource utilization at each layer independently. This allows better network efficiency to be achieved. We present two inter-layer path control models. One is a cooperation model with PCE and virtual network topology (VNT) manager. The other is higher-layer signaling trigger model. We compares these models in terms of functions of the network manager, node functions, and signaling time. We also discuss PCE standardizations in Internet Engineering Task Force (IETF).","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121063881","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}
V. Filimonov, A. Mainwaring, I. Shishalov, M. Shuralev, A. Umnov
{"title":"Adaptive reactance parasitic antenna array","authors":"V. Filimonov, A. Mainwaring, I. Shishalov, M. Shuralev, A. Umnov","doi":"10.1109/SARNOF.2007.4567314","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567314","url":null,"abstract":"This paper presents initial experiences with the design and implementation of a low-cost beam steering antenna for long-distance WIFI applications. The antenna system has three components: (1) an adaptive parabolic reflector constructed from an array of passive scatterers with tunable reactive loads, (2) an optimizer that runs on a host computer that adjusts the phases and amplitudes of their currents based on received signal strengths, and (3) a minimal hardware controller that interfaces to an array of digital-to-analog converters and varactor bias voltage logic. Experimental measurements confirm electrodynamics simulations and show that highly directional patterns can be realized while controlling orientation in azimuth and elevation. Initial results achieve 18 dBi of gain across an operational 50 degrees of azimuth with a beam width of 10 degrees. Higher gains of 22 dBi or more are possible with reduced range of steerability.","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117125562","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}
{"title":"Reduced-complexity bandwidth-constrained distributed estimation for wireless sensor networks","authors":"T. Jacobs, H. Minn, N. Al-Dhahir","doi":"10.1109/SARNOF.2007.4567319","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567319","url":null,"abstract":"While elegant in form, the maximum likelihood estimator (MLE) for heavily bandwidth-constrained distributed estimation in Gaussian noise is computationally expensive to implement. We consider an alternative estimator for this case which requires far less computational complexity, yet performs close to the MLE under the same operating conditions.","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126951186","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}
{"title":"Proposing SVS-PNLMS algorithm for sparse echo cancellation","authors":"P. Mahale, M. Orooji","doi":"10.1109/SARNOF.2007.4567333","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567333","url":null,"abstract":"In this paper segment variable-step-size proportionate normalized least mean square (SVS-PNLMS) algorithm is proposed for acoustic echo cancellation (AEC) application which is introduced as an important issue in services like video conferencing. The analysis reveals that it performs a faster convergence rate compared to that of the recently introduced SPNLMS (segment proportionate normalized least mean square), PNLMS (proportionate normalized least mean square) algorithms. Compared with its proportionate counterparts e.g. PNLMS and SPNLMS, the proposed SVS-PNLMS algorithm not only results in a faster convergence rate for both white and colored noise inputs, but also preserves this initial fast convergence rate until it reaches to steady state. It also presents a higher tracking behavior for quasi-stationary inputs such as speech signal in addition to better performance in terms of computational complexity and resulting ERLE (echo return loss enhancement).","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123668414","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}
{"title":"Channel probing in the uplink of OFDM-based wireless systems","authors":"Seung-Hwan Lee, Yong-Hwan Lee","doi":"10.1109/SARNOF.2007.4567345","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567345","url":null,"abstract":"In this paper, we consider a new channel probing scheme for opportunistic scheduling in the uplink of orthogonal frequency division multiplexing (OFDM)-based wireless systems. To reduce signaling overhead for the probing, we consider a two-step channel probing process; called pre-probing and mainprobing. Good subchannels are first estimated through the pre-probing process using a probing signal transmitted through subcarriers spread out the whole bandwidth. Then, by sending a main-probing signal over only good subchannels, the proposed scheme can significantly reduce the probing signaling overhead without noticeable performance degradation compared to the full probing scheme. Finally, the performance of the proposed scheme is verified by computer simulation.","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122268957","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}
{"title":"Performance analysis of A-MPDU and A-MSDU aggregation in IEEE 802.11n","authors":"B. Ginzburg, A. Kesselman","doi":"10.1109/SARNOF.2007.4567389","DOIUrl":"https://doi.org/10.1109/SARNOF.2007.4567389","url":null,"abstract":"With recent improvements in physical layer (PHY) techniques, the achievable capacity for wireless LANs (WLANs) has grown significantly. However, the overhead of IEEE 802.11 MAC layer has limited the actual throughput of a WLAN. A-MPDU aggregation suggested in IEEE 802.11n draft is a key enhancement reducing the protocol timing overheads that enables aggregation of several MAC-level protocol data units (MPDUs) into a single PHY protocol data unit (PPDU). Another aggregation scheme proposed in IEEE 802.11n is A-MSDU aggregation, which allows several MAC-level service data units (MSDUs) to be aggregated into a single MPDU. In this work we present a novel analytic model for estimating the performance of a 802.11n high throughput wireless link between a station and an Access Point (AP). We consider a 2 times 2 MIMO system and investigate how the MAC goodput under TCP and UDP traffic is affected by the aggregation size, packet error rate and PHY settings. Our results demonstrate that for UDP traffic, A-MPDU aggregation allows to achieve a high channel utilization of 95% in the ideal case while without aggregation the channel utilization is limited by just 33%. We also show that A-MPDU aggregation outperforms A-MSDU aggregation, whose performance considerably degrades for high packet error rates and high PHY rates.","PeriodicalId":293243,"journal":{"name":"2007 IEEE Sarnoff Symposium","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133772119","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}