Overlay Profile Research Articles

Evolution of multiple-access networks — cellular and non-cellular — in historical perspective. Part 4

Introduction:The goal of this issue is the analysis of evolution of the current and novel wireless networks, from second generation (2G) to fifth generation (5G), as well as changes in technologies and their corresponding theoretical background and protocols — from Bluetooth, WLAN, WiFi and WiMAX to LTE, OFDM/OFDMA, MIMO and LTE/MIMO advanced technologies with new hierarchy of cellular maps design — femto/pico/micro/macro.Methods:We use new theoretical frameworks for description of the advanced technologies, such as multicarrier diversity technique, OFDM and OFDM novel approach, MIMO aspects description based on multi-beam antennas approach, various cellular maps design based on a new algorithms of femto/pico/micro/macrocell deployment, and a new methodology of a new MIMO/LTE system integration based on multi-beam antennas.Results:We have created a new methodology of multi-carrier diversity description for novel multiple-access networks, of usage of OFDM/OFDMA modulation to obey inter-user and inter-symbol interference in multiple-access networks, of how to obey the multiplicative noises occurring in the multiple-access wireless networks, caused by multi-ray phenomena, and finally, of how to overcome propagation effects occurring in the terrestrial communication links by use combination of MIMO and LTE technologies based on multi-beam antennas. For these purposes we present new stochastic approach that accounts for the terrain features, such as buildings’ overlay profile, buildings’ density around the base station and each user antennas, and so forth. These parameters allow us to estimate for each situation occurs at the built-up terrain area the effects of fading, as a source of multiplicative noise.Practical relevance:New methodology of how to estimate effects of multiplicative noise, inter-user and inter-symbol interference, occurring in the terrestrial wireless networks, allows us to predict a-priory practical aspects of the current and new multiple-access wireless communication networks, such as: the users’ capacity and user’s links spectral efficiency for various configurations of cells deployment — femto, pico, micro, and macro, as well as the novel MIMO/LTE system configuration for future networks of 4th and 5th generation deployment.

Evolution of multiple-access networks - cellular and non-cellular - in historical perspective. Part 3

Introduction:The goal of this issue is the analysis of evolution of the current and novel wireless networks, from second generation (2D) to fifth generation (5G), as well as changes in technologies and their corresponding theoretical background and protocols — from Bluetooth, WLAN, WiFi and WiMAX to LTE, OFDM/OFDMA, MIMO and LTE/MIMO advanced technologies with new hierarchy of cellular maps design — femto/plco/mlcro/macro.Methods:We use new theoretical frameworks for description of the advanced technologies, such as multicarrier diversity technique, OFDM and OFDM novel approach, MIMO aspects description based on multi-beam antennas approach, various cellular maps design based on a new algorithms offemto/pico/micro/macrocell deployment, and a new methodology of a new MIMO/LTEsystem integration based on multi-beam antennas.Results:We have created a new methodology of multi-carrier diversity description for novel multiple-access networks, of usage of OFDM/OFDMA modulation to obey inter-user and inter-symbol interference in multiple-access networks, of how to obey the multiplicative noises occurring in the multiple-access wireless networks, caused by multi-ray phenomena, and finally, of how to overcome propagation effects occurring in the terrestrial communication links by use combination of MIMO and LTE technologies based on multi-beam antennas. For these purposes we present new stochastic approach that accounts for the terrain features, such as buildings' overlay profile, buildings' density around the base station and each user antennas, and so forth. These parameters allow us to estimate for each situation occurs at the built-up terrain area the effects of fading, as a source of multiplicative noise.Practical relevance:New methodology of how to estimate effects of multiplicative noise, inter-user and inter-symbol interference, occurring in the terrestrial wireless networks, allows us to predict a-priory practical aspects of the current and new multiple-access wireless communication networks, such as: the users' capacity and user's links spectral efficiency for various configurations of cells deployment — femto, pico, micro, and macro, as well as the novel MIMO/LTEsystem configuration for future networks of 4thand 5thgeneration deployment.

Evolution of multiple-access networks cellular and non-cellular — in historical perspective. Part 1

Introduction:The goal of this review is the analysis of evolution of the current and novel wireless networks, from secondgeneration (2D)tofifth generation(5G),as well as changes in technologies and their corresponding theoretical background andprotocols -from Bluetooth, WLAN, WiFi and WiMAXtoLTE, OFDM/OFDMA, MIMO and LTE/MIMO advanced technologies with new hierarchy of cellular maps design — femto/pico/micro/macro.Methods:We use new theoretical frameworkstodescribe advanced technologies, such as multicarrier diversity technique, OFDM and OFDM novel approach, new aspects ofMIMO description based on multi-beam antennas, design of various cellular maps based on new algorithms of femto/pico/micro/macrocell deployment, and the methodology of a new MIMO/LTE system integration based on multi-beam antennas.Results:We have created a new methodology for multi-carrier diversity description of novel multiple-access networks, forthe usage of OFDM/OFDMA modulation in ordertoovercome inter-user and inter-symbol interference in multiple-access networks, as well as multiplicative noises in multiple-access wireless networks caused by multi-ray phenomena. Finally, wehave suggested howtoovercome the propagation effects occurring in the terrestrial communication channels by using acombination of MIMO and LTE technologies based on multi-beam antennas. For these purposes, we present a new stochasticapproach which takes into account the terrain features, such as buildings' overlay profile, buildings' density around the base station and each user's antennas, andsoforth. These parameters allow ustoestimate the effects of fading as a multiplicativenoise source.Practical relevance:The new methodology of estimating the effects created by multiplicative noise and inter-user and inter-symbol interference in terrestrial wireless networks allows ustopredict a-priory practical aspects of the currentand new multiple-access wireless communication systems, like the potential number of users or the spectral efficiency ofuser channels for various configurations of cell deployment: femto, pico, micro, and macro, as well as the novel MIMO/LTE system configurations for future networks of the 4th and 5th generations.

Inhibition of quorum sensing in Chromobacterium violaceum by Syzygium cumini L. and Pimenta dioica L.

ObjectiveTo investigated into the anti-quorum sensing (QS) activity of Syzygium cumini L. (S. cumini) and Pimenta dioica L. (P. dioica) using Chromobacterium violaceum (C. violaceum) strains. MethodsIn this study, anti-QS activity of ethanol extract of Syzygium cumini L. and Pimenta dioica L. were screened using C. violaceum CV026 biosensor bioassay. By bioassay guided fractionation of S. cumini and P. dioica, ethyl acetate fraction (EAF) with strong anti-QS activity was separated. Inhibition of QS regulated violacein production in C. violaceum ATCC12472 by EAF was assessed at different concentrations. The effect of EAF on the synthesis of autoinducer like N-acyl homoserine lactone (AHL) was studied in C. violaceum ATCC31532 using its mutant C. violaceum CV026 by standard methods. ResultsEAF inhibited violacein production in C. violaceum ATCC12472 in a concentration dependent manner without significant reduction in bacterial growth. Complete inhibition of violacein production was evidenced in 0.75–1.0 mg/mL concentration of EAF without inhibiting the synthesis of the AHL. TLC biosensor overlay profile of EAF revealed two translucent spots in S. cumini and P. dioica that inhibited C6-AHL mediated violacein production in C. violaceum CV026. ConclusionsThis study indicates the anti-QS activity of the tested medicinal plants against C. violaceum.

Prediction of fading phenomena in land-satellite communication links

[1] This paper addresses the problem of prediction of probability of successful radio communication of any mobile or stationary subscriber located in areas of service such as complex urban environments characterized by nonline-of-sight propagation conditions, which limit GPS, Low Earth Orbit, and Medium Earth Orbit services in land-satellite communications. It presents a self-consistent physical-statistical approach for predicting fading phenomena usually occurring in land-satellite communication links caused by influence of the terrain features on radio signal propagation from the ground-based to the satellite antenna. This approach combines (1) the statistical description of the buildings array located on the rough terrain and the buildings' overlay profile, based on special probabilistic distributions of built-up terrain parameters, and (2) the theoretical description of propagation phenomena, taking into account multiple scattering, reflection, and diffraction mechanisms. A new technique is proposed for predicting the probability of fading phenomena occurring in land-satellite links using the so-called stochastic multiparametric model. Results of theoretical predictions are compared with those obtained from the “pure statistical” Lutz model and physical-statistical Saunders-Evans model, and then with experimental data obtained for different European cities. Obtained results show that the proposed stochastic approach can be used as a good predictor of fading phenomena in land-satellite communication links for different satellite constellation scenarios and elevations of satellites during their movement surrounding the Earth, with respect to the ground-based antenna for different land environments: rural, mixed residential, suburban, and urban.

The Design of Radio Maps in Tokyo City Based on Stochastic Multi-Parametric and Deterministic Ray-Tracing Approaches [Wireless Corner

This study is related to the investigation of two popular planning tools based on different approaches. The first is a stochastic model as a combination of a statistical description of features of rough built-up terrain (with arrays of buildings inside it), and the stochastic description of radio propagation above such a terrain, accounting for multiple reflection, scattering, and diffraction. The second is a deterministic ray-tracing model using direct computations of numerous rays arriving at the receiver from each point of the obstructions placed in the terrain. Both models are used to explain the propagation phenomena occurring inside urban communication links, and to design radio maps of areas of service in the space domain, for various elevations of the base-station antenna with respect to the buildings' overlay profiles. A comparison of two such theoretical predictors is done for an experimental site in Tokyo. It is shown that both proposed predictors are in good agreement with each other. At the same time, simple engineering formulas obtained from the stochastic model, taking into account shadowing effects caused by diffraction from buildings having non-regular overlay profiles with respect to the base-station antenna's elevation, have a vivid physical and mathematical form, usually converted into the ?straight line? equations obtained from the proposed stochastic model. The general trend is predicted by this stochastic model, and the deterministic ray tracing provides us with fine structures superimposed on such a trend.

SU-FF-T-224: Comparison of Commercial 2D and 3D Devices for Patient-Specific IMRT QA

Purpose: To compare the pass/fail rates for intensity modulated radiotherapy(IMRT) plans using the OmniPro I'mRT MatriXX and ScandiDos Delta4® IMRT QA devices. Method and Materials: Optimized IMRT plans for different anatomical sites were created using the Pinnacle3 v.8.0m treatment planning system for several patients. All the plans were optimized for delivery using a Varian 23EX with an 80 leaf MLCcollimator. For each plan two respective QA plans were created: one for the MatriXX and one for the Delta4 device. The planar doses at the location of the detector plane of each device were then exported, and each QA plan was delivered to each of the IMRT QA devices. The measured planar doses were compared against the calculated ones from the TPS. The measured and calculated planar doses were compared using isodose overlay, vertical and horizontal profiles, and gamma index. The acceptance criteria for the gamma index were set so that 95% of the pixels should be within gamma index of 1 defined by 3% and 3mm DTA. Results: Similar results were obtained from both measuring devices when compared to the respective planar dose distribution by the TPS. All plans in this investigation delivered to the MatriXX and Delta4® devices were deemed to have passed, with greater than 98% of point measurements having gamma values less than or equal to 1. It was found that there was good correlation between the gamma results from both devices for most plans. Conclusion: Analysis of the IMRT plans with the MatriXX and Delta4® devices yielded very similar pass/fail results. Either of the two devices is suitable for 2D analysis of the IMRT QA plans considered.

SU‐FF‐T‐421: Tomotherapy Patient‐Specific Quality Assurance

Purpose: To verify the patient‐specific dosimetric accuracy of the helical tomotherapy system. Methods and Materials: Tomotherapy is a new and complex delivery system. Varying parameters such as pitch and modulating the beam at various angles during fan‐beam delivery can produce highly conformal dose distributions. Patient‐specific dosimetric verification is thus critical. This study uses a custom‐designed 18×18×18 cm3 phantom made from water‐equivalent plastic and Exradin #a1SL ionization chambers to perform patient‐specific quality assurance (QA) procedures. During treatment, proper positioning of the patient is critical to avoid compromising treatment delivery. Tomotherapy allows roll correction to compensate for patient positioning errors. The roll correction was tested for 5°, 10°, 20°, and 30° using radiographic film dosimetry, the “cheese” phantom and the custom‐designed cuboid phantom. Results: Average ionization chamber correction factors for all patients treated on Tomotherapy were within 1.2%. Film dosimetry for every patient was also performed prior to treatment. Gamma and isodose overlay profiles were analyzed using commercial film analysis software. Results showed no significant dose delivery errors, and all patients passed within 5%. Gamma analysis was performed and showed excellent agreement by comparison with plans without phantom rotation. Gamma values were within 3.3% at 3mm and 5% distance to agreement. A custom leaf‐control file, or sinogram, is created for each patient's plan, and replicated each time the patient plan is to be delivered. Dosimetric verification for three patient plans was performed to verify the integrity of the sinogram replication process. Results for each tested plan agreement within 1% for each patient fraction. Conclusion: Tomotherapy allows for accurate delivery, and accurately applies the roll correction as shown by direct dose distribution measurements. Conflict of Interest: This work supported in part by a grant from Tomotherapy, Inc.

Link budget and radio coverage design for various multipath urban communication links

This study deals with theoretical and experimental prediction of types of fading, slow and fast, and the total path loss that occur in the urban land radio channel for various elevations of base station and moving subscriber antenna with respect to building rooftops. A new distribution function, which covers the well‐known classical Rice and Rayleigh statistical distributions, is derived on the basis of experimental data obtained for various situations in the urban scene and of the stochastic multiparametric model that describes multiray effects that occur in the urban communication link. The total path loss is derived for various urban propagation scenarios, taking into account the corresponding fading caused by shadowing and multipath effects. Radio maps of two experimental urban sites are designed. On the basis of the topographic features of one of these sites, the optimal number of antennas and their positions are predicted to achieve maximum radio coverage of area of service. The obtained results allow us to use the proposed unified stochastic model for slow and fast fading effects estimation in link budget performance and radio map design only on the basis of the topographic map of the corresponding terrain under investigations, the buildings' overlay profile, and the parameters of the base station antennas.

Signal distribution in the azimuth, elevation, and time-delay domains in urban radio communication links

We investigate the mutual power-spectra distributions in the azimuth, elevation, and time-delay domains in different urban environments with randomly distributed arrays of buildings placed on rough terrain. This is done for various orientations of street guiding structures in the urban scene, and for different elevations of the terminal antenna, the base station, and the subscriber, whether mobile or not, and with respect to the buildings' overlay profile. A combination of the stochastic multi-parametric and crossing-street waveguide models, created earlier, is used to describe a total probability-density function (PDF) of mutual azimuth time-delay, elevation time-delay, and azimuth-elevation distribution of multiply reflected signals arriving at the receiver after multiple reflection, diffraction, and scattering from the numerous obstructions surrounding both terminal antennas. Comparisons with some high-resolution three-dimensional measurements, as well as with the corresponding three-dimensional numerical ray-tracing model, are done to describe directional and spatial-temporal urban channel characteristics, and to predict propagation situations in the urban scene for various locations and directional properties of the terminal antennas.

Prediction of loss characteristics in built-up areas with various buildings' overlay profiles

We continue the analysis of a probabilistic approach and the corresponding stochastic multi-parametric model of wave propagation in built-up areas with randomly distributed buildings. We concentrate on the influence of buildings' overlay profiles on signal spatial decay, and on path-loss dependence in the frequency domain within UHF/X-band urban propagation channels. Using different buildings' overlay profiles, the field-intensity attenuation along radio paths is examined, taking into account single-scattering and multiple-scattering phenomena, and diffraction from buildings' corners and rooftops, for various positions of receiver and transmitter antennas with respect to surrounding obstacles. The comparison between experimental and theoretical predictions was motivated by the proposed stochastic multi-parametric model and the experimental data obtained for actual areas in Jerusalem (Israel) and Lisbon (Portugal), as well as by other models of multiple diffraction. The discussion is presented for realistic elevations of both terminal antennas to assess the accuracy and limits of the proposed stochastic model. A sensitivity analysis of the influence on the path loss of built-up terrain parameters and the elevation of antennas relative to the buildings surrounding them is presented.