Correlation between dental classification and upper airway measurements using acoustic rhinometry and pharyngometry

PURPOSE: To determine the prevalence of Sleep Disturbances (SD) in children and to evaluate the correlation between dental classification and airway dimensions. METHODS: Children between 3 – 18 years at the Boston University Pediatric Oral Healthcare Center in Boston, Massachusetts were recruited for this study. Based on parents’ responses in a brief sleep-screening questionnaire, cases were identified as children with SD and controls were those without. Another detailed questionnaire was used to collect information on demographics and sleep patterns. Clinical and upper airway examinations were conducted using Eccovision Acoustic Rhinometer (AR) and Acoustic Pharyngometer (AP). Statistical differences in upper airway measurements by type of dental occlusion were evaluated. RESULTS: Among 281 children, the prevalence of SD was 38%. Upper airway measurements among 176 participants using AP showed significantly higher pharyngeal Minimum Cross-Sectional Area (MCA) for class III dental occlusion compared to class I (P=.036) in children with SD. Statistically significant differences in MCA, Airway Volume (AV), and minimum distance to MCA by type of dental occlusion were mainly observed among children with SD (P<.05). CONCLUSIONS: The results highlight a possible correlation between nasal and pharyngeal airway dimensions and dental classification among children with SD. Further analysis that include radiological examinations may help in confirming these findings

A Random Trajectory Approach for the Development of Nonstationary Channel Models Capturing Different Scales of Fading

This paper introduces a new approach to developing stochastic nonstationary channel models, the randomness of which originates from a random trajectory of the mobile station (MS) rather than from the scattering area. The new approach is employed by utilizing a random trajectory model based on the primitives of Brownian fields (BFs), whereas the position of scatterers can be generated from an arbitrarily 2-D distribution function. The employed trajectory model generates random paths along which the MS travels from a given starting point to a fixed predefined destination point. To capture the path loss, the gain of each multipath component is modeled by a negative power law applied to the traveling distance of the corresponding plane wave, whereas the randomness of the path traveled results in large-scale fading. It is shown that the local received power is well approximated by a Gaussian process in logarithmic scale, even for a very limited number of scatterers. It is also shown that the envelope of the complex channel gain follows closely a Suzuki process, indicating that the proposed channel model superimposes small-scale fading and large-scale fading. The local power delay profile (PDP) and the local Doppler power spectral density (PSD) of the channel model are also derived and analyzed.acceptedVersionnivå

Personal and mobile communications

Issued as Final report, Project E-21-66

Principles of mobile communication

This mathematically rigorous overview of physical layer wireless communications is now in a 4th, fully revised and updated edition. The new edition features new content on 4G cellular systems, 5G cellular outlook, bandpass signals and systems, and polarization, among many other topics, in addition to a new chapters on channel assignment techniques. Along with coverage of fundamentals and basic principles sufficient for novice students, the volume includes finer details that satisfy the requirements of graduate students aiming to conduct in-depth research. The book begins with a survey of the field, introducing issues relevant to wireless communications. The book moves on to cover relevant discrete subjects, from radio propagation, to error probability performance, and cellular radio resource management. An appendix provides a tutorial on probability and random processes. The content stresses core principles that are applicable to a broad range of wireless standards. New examples are provided throughout the book to better explain the more complex material to the reader. Additional problems have also been added to those already appearing at the ends of the chapters to make the book more suitable for course instruction. Provides an updated textbook for university graduate-level courses teaching mobile communications or wireless communication Offers a rigorous study in the fundamentals and principles of wireless communication, with homework problems throughout Includes new content on 4G cellular systems, 5G cellular outlook, bandpass signals and systems, and polarization among many other topics and a new chapter on channel assignment techniques

Principles of Mobile Communication

This mathematically rigorous overview of physical layer wireless communications is now in a third, fully revised and updated edition. Along with coverage of basic principles sufficient for novice students, the volume includes plenty of finer details that will satisfy the requirements of graduate students aiming to research the topic in depth. It also has a role as a handy reference for wireless engineers. The content stresses core principles that are applicable to a broad range of wireless standards. Beginning with a survey of the field that introduces an array of issues relevant to wireless communications and which traces the historical development of today’s accepted wireless standards, the book moves on to cover all the relevant discrete subjects, from radio propagation to error probability performance and cellular radio resource management. A valuable appendix provides a succinct and focused tutorial on probability and random processes, concepts widely used throughout the book. This new edition, revised to include the latest information on this fast-evolving subject, will be required reading for students up to graduate level, and a practical everyday tool for engineers already working in the field

Cellular architectures and resource management

Issued as final repor

UHF spectrum study

Issued as final reportProcopio Business Consultin

Overview of Radiolocation in CDMA Cellular Systems

Applications for the location of subscribers of wireless services continue to expand. Consequently, location techniques for wireless technologies are being investigated. With code-division multiple access (CDMA) being deployed by a variety of cellular and PCS providers, developing an approach for location in CDMA networks is imperative. This article discusses the applications of location technology, the methods available for its implementation in CDMA networks, and the problems that are encountered when using CDMA networks for positioning. ireless location has received considerable attention over the past few years. A recent Report and Order issued by the U.S. Federal Communications Commission (FCC) in July 1996 requires that all wireless service providers, including cellular, broadband PCS, and wide-area SMR licensees, provide location information to Emergency 911 (E-911) public safety services [1]. Thes