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Title: System and Method for Determining and Sharing Spectrum Availability
Creator: Taher, Tanim, Roberson, Dennis
Date: 2017-06-16, 2017-06-13
Description: A method and apparatus for determining and sharing RF spectrum availability. The method includes automatically sensing and analyzing a...
Show moreA method and apparatus for determining and sharing RF spectrum availability. The method includes automatically sensing and analyzing a spectrum to identify used and/or unused portions of the spectrum, and automatically communicating the used and/or unused portions of the spectrum to a spectrum owner or a spectrum user. The invention has particular use in automatically identifying and quantifying current spectrum users, automatically reporting the current spectrum users to a spectrum owner, and/or allocating unused spectrum portions to users.
Sponsorship: Illinois Institute of Technology
United States Patent
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Title: APPLICATION OF SPECTRUM OBSERVATORY MEASUREMENTS TO SUPPORT TRAFFIC MODEL-BASED DYNAMIC SPECTRUM ACCESS
Creator: Taher, Tanim Mohammed
Date: 2014, 2014-07
Description: In a 2012 report, the President’s Council of Advisors in Science and Technology (PCAST) published a memorandum that calls for the...
Show moreIn a 2012 report, the President’s Council of Advisors in Science and Technology (PCAST) published a memorandum that calls for the identification of 1000 MHz of Federal Spectrum to be shared with private (commercial) users. This dissertation proposes a system that employs RF measurements for spectrum usage modeling and Dynamic Spectrum Access (DSA) methodologies that utilize the modeling information to permit sharing of wireless resources. A procedure called the Comprehensive Band Modeling (CBM) procedure is developed that automatically models measured RF data from any band of interest and identifies the locations of signals and holes present in the band. The output of the CBM procedure is summarized in a compact versatile format that makes DSA applications feasible. The research primarily focuses on the 450-474 MHz land mobile radio (LMR) band, and several additional bands like the TV band and the 2.5-2.7 GHz band. However, the research methodology and techniques are broadly applicable to many more frequency ranges. The research has four main areas: (a) spectrum sensor design and measurements, (b) occupancy modeling, (c) communicating the modeling information in a compact form to secondary users to support DSA algorithms and protocols, and (d) tools and metrics for spectrum sharing favorability analysis. Three spectrum sensor platforms were employed in measurements – (1) a spectrum analyzer based Spectrum Observatory (SO) that was developed earlier, (2) a specially purposed software-defined radio (SDR) for measuring LMR channels, (3) and a high-speed and portable SO system based on a sensor called the RFeye. An SO continually measures RF data in a band at a high temporal resolution such that the channel switching activity is seen – like, transmitters turning on and off. Spectrum measurements of the individual RF channels in the 450-474 MHz LMR band and the two commercial bands are used to generate statistical traffic and occupancy models. Long-term measurement data is used to assess how stationary the channel is, and how often the model parameters need to be updated. The spectrum observatory supports a network of Secondary Users (SU) by communicating the traffic model parameters in a compact format to the SUs. The SUs share Primary User (PU) channels via DSA techniques. The DSA algorithms take advantage of the model parameters provided by the SO to maximize SU throughput with limited interference on the PU. The DSA coexistence techniques are evaluated via simulation. The simulation results including Spectrum Opportunity Accessed (SOA), SU throughput, and collision rates are then analyzed to provide an assessment of DSA-based spectrum sharing in that band. The main contribution of this dissertation is the aforementioned CBM procedure. The white spaces in the frequency and time domains, that is, the underutilized spectrum opportunities available for possible secondary use via DSA are automatically identified, as well as the frequency locations that are not conducive to DSA due to the presence of frequent primary licensee transmissions. In CBM, white spaces are referred to as ‘Holes’, and the licensed primary transmission frequencies as ‘Signals’. Useful information about the duty cycles and traffic patterns of incumbent users’ activity within possible secondary use channels is extracted and modeled. The model enables prospective secondary users of white spaces to predict the expected level of interference in any channel, which allows for channel ranking and optimal selection of DSA transmission parameters. The CBM model is describable by a tiered structure, where the first tier identifies the holes and signals; the second tier ranks the holes in terms of available bandwidth and incumbent duty cycle; and the third tier models the infrequent incumbent transmissions. With the three tiers of information, an SU can readily identify all the suitable DSA channels within the entire spectrum band. This essential summary information is retrieved as a “Hole Descriptor Object” (HDO) that is both compact and tractable. Empirical spectrum measurement data obtained from the three different SO platforms is used to test the performance of the CBM procedure in the 2500-2700 MHz frequency range that currently has WiMAX deployments, the TV white space band, and the 450-474 MHz LMR band in Chicago. Spectrum measurement data runs into hundreds of megabytes or gigabytes. As such, the raw information is not very applicable in practical wireless networks. The HDO objects on the other hand are compact and only kilobytes in size. The HDO objects contain all the useful and applicable information necessary for any smart radio (primary or secondary) to select transmission parameters like frequency of operation and bandwidth, so that it can efficiently operate. Thus, the advantage of the CBM procedure is that it summarizes gigabytes of raw spectrum measurements in a usable compact format that can be directly used by practical smart radios to operate using DSA paradigms. Another advantage of CBM is that it is comprehensive and automatically identifies all holes and signals. The research findings are of interest and value to a variety of Federal and Commercial entities. The models and relevant model parameters for public safety radio in the LMR band have been provided on request to the Public Safety and Homeland Security Bureau of the Federal Communications Commission (FCC). The DSA feasibility analysis methodology is of great national economic interest based on the contents of the PCAST report. The PCAST report recommends finding 1000 MHz of federal frequencies to be allocated for shared commercial and federal use. However, the technology for doing so and identifying the suitable bands requires measurements of actual spectrum usage, modeling the occupancy and existing traffic activity, and assessing DSA feasibility – these are important research aspects, and all of which are addressed in this dissertation. The results are of crucial importance to policy makers like the FCC and NTIA who will ultimately make the spectrum allocations decisions. A future network of commercial DSA SU radios operating in a shared band is likely to need access to a system to obtain live information about PU activity to optimally operate in the band with high throughput and low interference. The overall system, based on the CBM procedure and HDO objects, proposed in this thesis describes a framework for providing this information as a service to DSA networks, and hence the work is also of practical relevance to radio system designers.
Ph.D. in Electrical Engineering, July 2014
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Title: Empirical Modeling of Public Safety to Voice Traffic to Aid Emergency Capacity
Creator: Taher, Tanim, Bacchus, Roger
Date: 2012-04-18, 2012-04-18
Description: An RF measurement system with high time resolution is implemented to determine the statistical characteristics of various channels in the Land...
Show moreAn RF measurement system with high time resolution is implemented to determine the statistical characteristics of various channels in the Land Mobile Radio bands. The applicability of simple statistical models to the observed data is investigated, as well as their validity over short and long periods of time. The results show that the statistics of the idle and holding times of communication on these channels vary significantly over time and demonstrate daily periodicity, requiring non-stationary models to accurately represent them. Over short durations of time however, conventional distributions such as the exponential and lognormal may adequately characterize the properties of these quantities, allowing convenient and compact representations of the data. Results based on empirical data are presented to quantify the probability of stationarity for voice traffic within a time span of given length. The findings are useful for network planning or streamlining, network simulation and modeling, and investigation of dynamic spectrum access.
Sponsorship: National Science Foundation, Federal Communications Commission, Motorola, Cleversafe, Roberson & Associates LLC
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Title: Heat Driven Refrigeration System (Semester 2 of Unknown), IPRO 357: Heat Driven Refrigeration System IPRO 357 Final Report F04
Creator: Alworth, Tom, Frost, Alec, Vogel, Stefan, Callow, Alex, Kim, Keon, Lee, Donghoon, Ahmadia, Aron, Keen, Andrew, Medrano, Anel, Nortes, Leo, Taher, Tanim
Date: 2005-01, 2004-12
Description: The solution will take the form of a novel system based on a refrigeration cycle driven by heat. The cycle will be built around a "pressure...
Show moreThe solution will take the form of a novel system based on a refrigeration cycle driven by heat. The cycle will be built around a "pressure exchanger" consisting of a piston, along with solenoid valves controlled by a microprocessor. Heat will most likely be obtained through the combustion of biomass such as plant by-products and animal wastes, but will be flexible enough to allow for more conventional fuel types such as kerosene and coal.
Sponsorship: ASHRAE, NCIIA
Deliverables
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Title: Heat Driven Refrigeration System (Semester 2 of Unknown), IPRO 357: Heat Driven Refrigeration System IPRO 357 Project Plan F04
Creator: Alworth, Tom, Frost, Alec, Vogel, Stefan, Callow, Alex, Kim, Keon, Lee, Donghoon, Ahmadia, Aron, Keen, Andrew, Medrano, Anel, Nortes, Leo, Taher, Tanim
Date: 2005-01, 2004-12
Description: The solution will take the form of a novel system based on a refrigeration cycle driven by heat. The cycle will be built around a "pressure...
Show moreThe solution will take the form of a novel system based on a refrigeration cycle driven by heat. The cycle will be built around a "pressure exchanger" consisting of a piston, along with solenoid valves controlled by a microprocessor. Heat will most likely be obtained through the combustion of biomass such as plant by-products and animal wastes, but will be flexible enough to allow for more conventional fuel types such as kerosene and coal.
Sponsorship: ASHRAE, NCIIA
Deliverables
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Title: Heat Driven Refrigeration System (Semester 2 of Unknown), IPRO 357
Creator: Alworth, Tom, Frost, Alec, Vogel, Stefan, Callow, Alex, Kim, Keon, Lee, Donghoon, Ahmadia, Aron, Keen, Andrew, Medrano, Anel, Nortes, Leo, Taher, Tanim
Date: 2005-01, 2004-12
Description: The solution will take the form of a novel system based on a refrigeration cycle driven by heat. The cycle will be built around a "pressure...
Show moreThe solution will take the form of a novel system based on a refrigeration cycle driven by heat. The cycle will be built around a "pressure exchanger" consisting of a piston, along with solenoid valves controlled by a microprocessor. Heat will most likely be obtained through the combustion of biomass such as plant by-products and animal wastes, but will be flexible enough to allow for more conventional fuel types such as kerosene and coal.
Sponsorship: ASHRAE, NCIIA
Deliverables
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Title: Heat Driven Refrigeration System (Semester 2 of Unknown), IPRO 357: Heat Driven Refrigeration System IPRO 357 Abstract F04
Creator: Alworth, Tom, Frost, Alec, Vogel, Stefan, Callow, Alex, Kim, Keon, Lee, Donghoon, Ahmadia, Aron, Keen, Andrew, Medrano, Anel, Nortes, Leo, Taher, Tanim
Date: 2005-01, 2004-12
Description: The solution will take the form of a novel system based on a refrigeration cycle driven by heat. The cycle will be built around a "pressure...
Show moreThe solution will take the form of a novel system based on a refrigeration cycle driven by heat. The cycle will be built around a "pressure exchanger" consisting of a piston, along with solenoid valves controlled by a microprocessor. Heat will most likely be obtained through the combustion of biomass such as plant by-products and animal wastes, but will be flexible enough to allow for more conventional fuel types such as kerosene and coal.
Sponsorship: ASHRAE, NCIIA
Deliverables
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Title: Design of a Hybrid electric People Transporter (semester?), IPRO 304: Hybrid Electric Fuel Cell Battery IPRO 304 Abstract F04
Creator: Langel, Steve, Smith, Alison, Weber, Ken, Lim, Dong Chul, Kraft, Rick, Lefief, Chrissy, Moy, Matt, Omolaoye, Olatunde, Ayersman, Matt, Aderangi, Vince, Prince, Mike, Bachmann, Matt, Eisenberg, David, Buresh, Rita, Piputkar, Siddha, Johnson, Steven, Taher, Tanim
Date: 2004-12, 2004-12
Description: The main objective and purpose of this IPRO is to create a hybrid system using a hydrogen PEM fuel cell and Lithium-Ion batteries to power a...
Show moreThe main objective and purpose of this IPRO is to create a hybrid system using a hydrogen PEM fuel cell and Lithium-Ion batteries to power a wheel chair so that it will be capable of transporting one person for at least 100 miles without experiencing any major difficulties.
Deliverables for IPRO 304: Design of a Hybrid electric People Transporter for the Fall 2004 semester
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Title: Design of a Hybrid electric People Transporter (semester?), IPRO 304: Hybrid Electric Fuel Cell Battery IPRO 304 Midterm Report F04
Creator: Langel, Steve, Smith, Alison, Weber, Ken, Lim, Dong Chul, Kraft, Rick, Lefief, Chrissy, Moy, Matt, Omolaoye, Olatunde, Ayersman, Matt, Aderangi, Vince, Prince, Mike, Bachmann, Matt, Eisenberg, David, Buresh, Rita, Piputkar, Siddha, Johnson, Steven, Taher, Tanim
Date: 2004-12, 2004-12
Description: The main objective and purpose of this IPRO is to create a hybrid system using a hydrogen PEM fuel cell and Lithium-Ion batteries to power a...
Show moreThe main objective and purpose of this IPRO is to create a hybrid system using a hydrogen PEM fuel cell and Lithium-Ion batteries to power a wheel chair so that it will be capable of transporting one person for at least 100 miles without experiencing any major difficulties.
Deliverables for IPRO 304: Design of a Hybrid electric People Transporter for the Fall 2004 semester
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Title: Design of a Hybrid electric People Transporter (semester?), IPRO 304: Hybrid Electric Fuel Cell Battery IPRO 304 IPRO Day Presentation F04
Creator: Langel, Steve, Smith, Alison, Weber, Ken, Lim, Dong Chul, Kraft, Rick, Lefief, Chrissy, Moy, Matt, Omolaoye, Olatunde, Ayersman, Matt, Aderangi, Vince, Prince, Mike, Bachmann, Matt, Eisenberg, David, Buresh, Rita, Piputkar, Siddha, Johnson, Steven, Taher, Tanim
Date: 2004-12, 2004-12
Description: The main objective and purpose of this IPRO is to create a hybrid system using a hydrogen PEM fuel cell and Lithium-Ion batteries to power a...
Show moreThe main objective and purpose of this IPRO is to create a hybrid system using a hydrogen PEM fuel cell and Lithium-Ion batteries to power a wheel chair so that it will be capable of transporting one person for at least 100 miles without experiencing any major difficulties.
Deliverables for IPRO 304: Design of a Hybrid electric People Transporter for the Fall 2004 semester
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Title: Design of a Hybrid electric People Transporter (semester?), IPRO 304: Hybrid Electric Fuel Cell Battery IPRO 304 Final Report F04
Creator: Langel, Steve, Smith, Alison, Weber, Ken, Lim, Dong Chul, Kraft, Rick, Lefief, Chrissy, Moy, Matt, Omolaoye, Olatunde, Ayersman, Matt, Aderangi, Vince, Prince, Mike, Bachmann, Matt, Eisenberg, David, Buresh, Rita, Piputkar, Siddha, Johnson, Steven, Taher, Tanim
Date: 2004-12, 2004-12
Description: The main objective and purpose of this IPRO is to create a hybrid system using a hydrogen PEM fuel cell and Lithium-Ion batteries to power a...
Show moreThe main objective and purpose of this IPRO is to create a hybrid system using a hydrogen PEM fuel cell and Lithium-Ion batteries to power a wheel chair so that it will be capable of transporting one person for at least 100 miles without experiencing any major difficulties.
Deliverables for IPRO 304: Design of a Hybrid electric People Transporter for the Fall 2004 semester
Show less

Title: Design of a Hybrid electric People Transporter (semester?), IPRO 304: Hybrid Electric Fuel Cell Battery IPRO 304 Project Plan F04
Creator: Langel, Steve, Smith, Alison, Weber, Ken, Lim, Dong Chul, Kraft, Rick, Lefief, Chrissy, Moy, Matt, Omolaoye, Olatunde, Ayersman, Matt, Aderangi, Vince, Prince, Mike, Bachmann, Matt, Eisenberg, David, Buresh, Rita, Piputkar, Siddha, Johnson, Steven, Taher, Tanim
Date: 2004-12, 2004-12
Description: The main objective and purpose of this IPRO is to create a hybrid system using a hydrogen PEM fuel cell and Lithium-Ion batteries to power a...
Show moreThe main objective and purpose of this IPRO is to create a hybrid system using a hydrogen PEM fuel cell and Lithium-Ion batteries to power a wheel chair so that it will be capable of transporting one person for at least 100 miles without experiencing any major difficulties.
Deliverables for IPRO 304: Design of a Hybrid electric People Transporter for the Fall 2004 semester
Show less

Title: Design of a Hybrid electric People Transporter (semester?), IPRO 304
Creator: Langel, Steve, Smith, Alison, Weber, Ken, Lim, Dong Chul, Kraft, Rick, Lefief, Chrissy, Moy, Matt, Omolaoye, Olatunde, Ayersman, Matt, Aderangi, Vince, Prince, Mike, Bachmann, Matt, Eisenberg, David, Buresh, Rita, Piputkar, Siddha, Johnson, Steven, Taher, Tanim
Date: 2004-12, 2004-12
Description: The main objective and purpose of this IPRO is to create a hybrid system using a hydrogen PEM fuel cell and Lithium-Ion batteries to power a...
Show moreThe main objective and purpose of this IPRO is to create a hybrid system using a hydrogen PEM fuel cell and Lithium-Ion batteries to power a wheel chair so that it will be capable of transporting one person for at least 100 miles without experiencing any major difficulties.
Deliverables for IPRO 304: Design of a Hybrid electric People Transporter for the Fall 2004 semester
Show less

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