ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV / Tracking small marmosets over a large area represents a significant challenge for researchers. The native habitat for such animals are generally unsuitable for GPS based location systems, and the size of the animals prevents large, feature-rich collars from being utilized. Additionally, costs and feasibility prevent researchers from continuously monitoring these animals on the ground. This paper proposes a new system of tracking that offsets complexity from the collar onto fixed Base Stations (BS). The simplified collars emit a ping that multiple BSs then log along with the power of the signal. Combining the data from different BSs allows for the determination of the Signal of Interest (SOI). It was found that using three BSs provided enough accuracy to determine the location of an SOI within an accuracy of 2 m² over a roughly 450 m² area.

Our related research review on propagation models reveals six factors that are significant in last mile connectivity via LAP: path loss, elevation angle, LAP altitude, coverage area, power consumption, operation frequency, interference, and antenna type. These factors can help with monitoring system performance, network planning, coverage footprint, receivers' line-of-sight, quality of service requirements, and data rates which may all vary in response to geomorphology characteristics. Several competing propagation models have been proposed over the years but whilst they collectively raise many shortcomings such as limited altitude up to few tens of meters, lack of cover across different environments, low perdition accuracy they also exhibit several advantages. Four propagation models, which are representatives of their types, have been selected since they exhibit advantages in relation to high altitude, wide coverage range, adaption across different terrains. In addition, all four have been extensively deployed in the past and as a result their correction factors have evolved over the years to yield extremely accurate results which makes the development and evaluation aspects of this research very precise. The four models are: ITU-R P.529-3, Okumura, Hata-Davidson, and ATG. The aim of this doctoral research is to design a new propagation model for last-mile connectivity using LAPs technology as an alternative to aerial base station that includes all six factors but does not exhibit any of the shortcomings of existing models. The new propagation model evolves from existing models using machine learning. The four models are first adapted to include the elevation angle alongside the multiple-input multiple-output diversity gain, our first novelty in propagation modelling. The four adapted models are then used as input in a Neural Network framework and their parameters are clustered in a Self-Organizing-Map using a minimax technique. The framework evolves an optimal propagation model that represents the main research contribution of this research. The optimal propagation model is deployed in two proof-of-concept applications, a wireless sensor network, and a cellular structure. The performance of the optimal model is evaluated and then validated against that of the four adapted models first in relation to predictions reported in the literature and then in the context of the two proof-of-concept applications. The predictions of the optimised model are significantly improved in comparison to those of the four adapted propagation models. Each of the two proof-of-concept applications also represent a research novelty.

Careful network planning has become increasingly critical with the rising deployment, coverage, and congestion of wireless local area networks (WLANs). This thesis outlines the achieved prediction accuracy of a direct-ray, single path loss exponent, adapted Seidel-Rappaport propagation model as determined through measurements and analysis of the established 2.4 GHz, 802.11g outdoor WiFi network deployed on the campus of the Georgia Institute of Technology. Additionally, the viability of using the obtained model parameters as a means for planning future network deployment is discussed. Analysis of measured data shows that accurate predictive planning for network coverage is possible without the need for overly complicated modeling techniques such as ray tracing. The proposed model performs with accuracy comparable to other commonly accepted, more complicated models and is offered as a simple, yet strong predictive model for network planning having both speed and accuracy. Results show, that for the area under study, the standard deviation of the prediction error for the proposed model is below 6.8dB in all analyzed environments, and is approximately 5.5dB on average. Further, the accuracy of model predictions in new environments is shown to be satisfactory for network planning.

In this thesis work, the locations where we are unable to reach via fiber are considered for wireless transmission links. In the practical part of this thesis different modulation techniques and antenna sizes were analyzed  in order to provide the most efficient way of data transmission. The data between this wireless links was transfered using MPLS L2 VPN solution.   According to improving technology and increasing internet usage, the communication speed, which is between users and providers, becomes more inevitable for transmitting data without any delays. More than one users might use same connection line for transmitting their packets and it is able to be caused an online traffic and some delays and data loss could occur. In this circumstance, high rate internet demands would lead extra costs for Internet Service Providers (ISPs) and users.   In the introduction part, a brief description for the history of communications and basic equipments for Radio Link and Fiber Optic cable are done.   In the theory part, detailed information was provided about modulation techniques and multiplexing techniques followed by general information about computer networks  and comprehensive information about OSI layers.   In the process and result parts, program outputs for Path Loss design which was used for R/L was mentioned in a detailed way. After that, Ethernet Over MPLS L2 VPN was highlighted and a simulation from point-to-point "Ethernet Over MPLS L2 VPN” was conducted in GNS3 software. Furthermore, the simulation for point-to-multipoint case was then applied  in a laboratory environment in order to achieve the desired result.   In the result part, different R/L simulation results are compared to determine the optimized modulation technique and antenna sizes which could then be merged with simulation results from the previous part.

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This thesis presents a grid-based indoor radiolocation technique based on a Spatially Coherent Path Loss Model (SCPL). SCPL is a path loss model which characterizes the radio wave propagation in an environment by solely using Received Signal Strength (RSS) fingerprints. The propagation of the radio waves is characterized by uniformly dividing the environment into grid cells, followed by the estimation of the propagation parameters for each grid cell individually. By using SCPL and RSS fingerprints acquired at an unknown location, the distance between an agent and all the access point in an indoor environment can be determined. A least-squares based trilateration is then used as the global fix of location the agent in the environment. The result of the trilateration is then represented in a probability distribution function over the grid cells induced by SCPL. Since the proposed technique is able to locally model the propagation accounting for attenuation of non-uniform environmental irregularities, the characterization of the path loss in the indoor environment and radiolocation technique might yield improved results. The efficacy of the proposed technique was investigated with an experiment comparing SCPL and an indoor radiolocation technique based on a conventional path loss model. / Master of Science / This thesis presents a technique uses radio waves to localize an agent in an indoor environment. By characterizing the difference between transmitted and received power of the radio waves, the agent can determine how far it is away from the transmitting antennas, i.e. access points, placed in the environment. Since the power difference mainly results from obstructions in the environment, the attenuation profile of the environment carries a significant importance in radiolocation techniques. The proposed technique, called Spatially Coherent Path Loss Model (SCPL), characterizes the radio wave propagation, i.e. the attenuation, separately for different regions of the environment, unlike the conventional techniques employing global attenuation profiles. The localization environment is represented with grid-cell structure and the parameters of SCPL model describing the extent of the attenuation of the environment are estimated individually. After creating an attenuation profile of the environment, the agent localizes itself in the localization environment by using SCPL with signal powers received from the access points. This scheme of attenuation profiling constitutes the main contribution of the proposed technique. The efficacy and validity of the proposed technique was investigated with an experiment comparing SCPL and an indoor radiolocation technique based on a conventional path loss model.

The most common railroad accidents today involve collisions between trains and passenger vehicles at railroad grade crossings [1][2]. Due to the size and speed of a train, these collisions generally result in significant damage and serious injury. Despite recent efforts by projects such as Operation Lifesaver to install safety features at grade crossings, up to 80% of the United States railroad grade crossings are classified as 'unprotected' with no lights, warnings, or crossing gates [2]. Further, from January to September 2012, nearly 10% of all reported vehicle accidents were a result of train-to-vehicle collisions. These collisions also accounted for nearly 95% of all reported fatalities from vehicular accidents [2]. To help provide a more rapidly deployable safety system, advanced dedicated short range communication (DSRC) systems are being developed. DSRC is an emerging technology that is currently being explored by the automotive safety industry for vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications to provide intelligent transportation services (ITS). DSRC uses WAVE protocols and the IEEE 1609 standards. Among the many features of DSRC systems is the ability to sense and then provide an early warning of a potential collision [6]. One potential adaption for this technology is for use as a train-to-vehicle collision warning system for unprotected grade crossings. These new protocols pose an interesting opportunity for enhancing cybersecurity since terrorists will undoubtedly eventually identify these types of mass disasters as targets of opportunity. To provide a thorough channel model of the train to vehicle communication environment that is proposed above, large-scale path loss and small scale fading will both be analyzed to characterize the propagation environment. Measurements were collected at TTCI in Pueblo Colorado to measure the received signal strength in a train to vehicle communication environment. From the received signal strength, different channel models can be developed to characterize the communication environment. Documented metrics include large scale path loss, Rician small scale fading, Delay spread, and Doppler spread. An analysis of the DSRC performance based on Packet Error Rate is also included. / Master of Science

First responders are continuously moving at an incident site and this movement requires them to access Service-Oriented Architecture services, such as a Web Map Service, via mobile wireless networks. First responders from inside a building often have problems in communicating to devices outside that building due to propagation obstacles. Dynamic user geometry and the propagation conditions of communicating from inside buildings to transceivers on the outside are difficult to model reliably in network planning software. Thus, leading commercial network simulation software and open source network simulator software do not model wireless links between transceivers inside and outside of buildings; new modeling software is needed. The discrete simulation runs in this investigation were built on events in a scenario that is typical of first-responder activities at an incident site. This scenario defined the geometry and node characteristics that were used in a mobile wireless network simulation to calculate expected connectivity based on propagation modeling, transceiver characteristics, and the environment. The author implemented in software a propagation model from the United States National Institute of Standards and Technology (NIST) to simulate radio wave propagation path loss during the scenario. Modifications to the NIST model propagation path loss method were generated to improve consistency in results calculated with the same node separation distances and radio wave obstacle environments. The final set of modifications made the NIST model more generalized by using more building material characteristics than the original version. The modifications in this study to the path loss model from NIST engineers were grounded on ad hoc network connectivity data collected at the operational scenario site. After changes in the NIST model were validated, 1,265 operational simulation runs were conducted with different numbers of deployed nodes in an operational incident-response scenario. Data were reduced and analyzed to compare measures of mobile ad hoc network effectiveness. Findings in this investigation resulted in two specific contributions to the body of knowledge in mobile wireless network design. First, data analysis indicated that specific changes to a recent path loss model from NIST produced results that were more generalized than the original model with respect to accommodating different building materials and enhancing the consistency of simulation results. Second, the results from the modified path loss model revealed an operational impact in using relay nodes to support public safety. Specifically, placing relay nodes at the entrance to a building and on odd-numbered floors improved connectivity in terms of first responders' accessing Web Services via mobile network devices, when moving through a building in an incident scenario.

Strong demand for wireless communications encourages academic research centres and industrial electronics and communication companies to keep improving the performance, increase the speed, extend the coverage area and enlarge the baud rate and capacity. LTE (Long Term Evolution) and WiMAX (the Worldwide Interoperability Microwave Access) are recent solutions for most wireless technologies. LTE and WiMAX coverage range are one of the important factors that affect the quality of broadband access services and mobile cellular systems in wireless communication. Predicting and evaluating the path loss is essential in planning and designing cellular mobile systems. This thesis presents a comprehensive study of path loss on LTE and mobile WiMAX to achieve large throughputs and wide coverage at the Cell-edge. The thesis introduces, analyzes and compares the path loss values, based on LTE and WiMAX standard at one carrier frequency, namely 3.5GHz and a variation of distances in the range of 1 to 50 km, in flat rural, suburban and urban environments. The thesis discusses and implements the Okumura, Hata, Cost-231, Ericsson, Erceg, Walfish, Ecc-33, Lee and the simplified free space path loss models. The objectives of path loss evaluation results are to calculate the link budget, the power outage and the base station cell coverage area for mobile cellular systems. A femtocell (FMC) is a low cost low power cellular home base station, operating in licensed spectrum. Because of the requirement for high data rates and improved coverage indoors, FMC provides a solution to these requirements. FMC is deployed mainly indoors and sometimes outdoors at the cell-edge to increase the area of coverage, capacity and in order to enhance the received signal in the user’s premises. The thesis presents the interference, SINR and the probability of connection for the downlink with different numbers of FMCs based on LTE and WiMAX OFDMA. Moreover, comparisons of interference, SINR and probability of connection for three different numbers of FMCs and for three different indoor areas are presented. In addition, a comparison for the probability of connection with various threshold values and numbers of FMCs is simulated and presented in 3-D. The probability of connection for a varied number of FMCs is a guide study to find the appropriate number of FMCs that could serve a specific indoor area and the proper number of UEs in the specified area. The thesis also presents the interference, SINR and the probability of connection at the uplink for a user equipment device (UE) to an FMC with varied number of UEs based on LTE and WiMAX OFDMA. Moreover, comparisons of the interference, SINR and probability of connection for three different areas at the uplink are presented. Therefore, analyzing probability of connection with varied number of UEs is a worthy study in order to identify the appropriate number of UEs that could be served by a specific number of FMCs at a specific indoor location. The thesis presents and investigates the capacity of MIMO with the presence of FMCs to perform cancellation of co-channel interference. The research introduces algorithms to calculate the capacity of MIMO with the presence of FMCs by two models. The simulation results show that the capacity equations of model-2 give better results than the capacity equations of model-1. Therefore, model-2 is used for the interference cancellation of MIMO in the presence of MIMO. Interference cancellation is performed at the downlink when the signal is transmitted from FMC to UE by mitigating and cancelling the interference which comes from the neighbouring FMCs to the target UE. The thesis introduces, explains and applies a novel algorithm to calculate the capacity of MIMO at the presence of FMCs with interference cancellation by these channel equalizers ZF, MMSE, VBLAST ZF, VBLAST MMSE and VBLAST OFDM MMSE.

Στην εποχή που ζούμε, η καθημερινότητα των πολιτών, από όλες σχεδόν τις πλευρές της, από την επαγγελματική και προσωπική της διάσταση έως τον τρόπο που επιλέγει πλέον κάποιος να διασκεδάζει και να κοινωνικοποιείται, είναι σε πολύ μεγάλο βαθμό εξαρτημένη από το νευραλγικό τομέα των επικοινωνιών. Διαπιστώνει κανείς πολύ εύκολα την ήδη εδώ και δεκαετίες, τεράστια διείσδυση των επικοινωνιών σε όλους τους παραγωγικούς τομείς της κοινωνίας, στους ίδιους τους μηχανισμούς της διακυβέρνησης και της ενημέρωσης. Το τεράστιο άλμα ωστόσο, πραγματοποιείται τα τελευταία χρόνια, με την ανάπτυξη των ασύρματων επικοινωνιών και διάφορων τεχνολογιών που προκύπτουν μέσα από επίπονη και πολύχρονη έρευνα. Κινητή τηλεφωνία, ασύρματα δίκτυα, πρόσβαση σε γρήγορο internet οπουδήποτε και οποτεδήποτε, είναι τεχνολογίες που έχουν αλλάξει δραματικά και ανεπιφύλακτα προς το καλύτερο, τις ζωές όλων μας. Στη παρούσα διπλωματική εργασία με τίτλο «Διερεύνηση τεχνικών παραμέτρων για βέλτιστη σχεδίαση συστημάτων τεχνολογίας Wi-Fi:», αφού πρώτα μελετήσουμε πλήρως το πρότυπο 802.11 ή κοινώς WiFi, όσο αφορά την αρχιτεκτονική του, τη δομή του και τις διάφορες εκδόσεις του, προχωράμε σε μια μελέτη γύρω από τα θεωρητικά μοντέλα διάδοσης της ηλεκτρομαγνητικής ακτινοβολίας σε εσωτερικούς χώρους με σκοπό να εξετάσουμε στη συνέχεια ένα τέτοιο πολύπλοκο περιβάλλον και τον τρόπο που συμπεριφέρεται το πρότυπο για μια συγκεκριμένη συχνότητα. Μέσω της μοντελοποίησης και της προσομοίωσης εκτιμάμε και αξιολογούμε τους παράγοντες που επηρεάζουν τη διάδοση αλλά και τυχόν καινούρια στοιχεία που μπορεί να προκύψουν. Στο πρώτο κεφάλαιο εισάγεται ο αναγνώστης στις ασύρματες επικοινωνίες με μια σύντομη ιστορική αναδρομή και την παρουσίαση των βασικών ασύρματων συσ τημάτων σήμερα. Στο κεφάλαιο δύο παρουσιάζεται πλήρως το πρότυπο 802.11. Αναπτύσσεται η αρχιτεκτονική του, η δομή του, το φυσικό του επίπεδο με τις τεχνικές μετάδοσης των διάφορων επικρατέστερων εκδόσεων του αλλά και οι λειτουργίες του επίπεδου MAC με τις παραμέτρους του. Προχωρώντας στο τρίτο κεφάλαιο, μελετάμε τους μηχανισμούς διάδοσης και τα φαινόμενα εξασθένισης του σήματος , κυρίως όμως γίνεται εκτενής αναφορά στα μοντέλα που περιγράφουν την ηλεκτρομαγνητική διάδοση σε περιβάλλον εσωτερικού χώρου, κάθως με βάση τα μοντέλα αυτά, γίνε ται η τελική αξιόγηση του πειραματικού μέρους της εργασίας. Στο τέταρτο κεφάλαιο παρουσιάζονται οι πειραματικές μας μετρήσεις, η τοπολογία και η διαδικασία με την οποία λήφθησαν. Πραγματοποιείται σύγκριση αυτών με τις προβλέψεις βασικών θεωρητικών μοντέλων, και μέσω προσομοίωσης που πραγματοποιήθηκε στο Matlab, εκτιμάται η απόκλιση των πειραματικών τιμών από τις θεωρητικές προβλέψεις. Στο τελευταίο κεφάλαιο παραθέτουμε τα γενικά συμπεράσματα που προέκυψαν από την πειραματική διαδικασία, αξιολογούμε τους παράγοντες που συνετέλεσαν στη λήψη των αποτελεσμάτων μας και αποφαινόμαστε για το καταλληλότερο μοντέλο στο περιβάλλον που εργαστήκαμε. / Nowadays, the citizen’s daily life from both the professional and personal point of view to the way somebody chooses to be socialized and get amused, is extremely dependent on the neuralgic field of communications. It becomes evident easily to anybody, the already for decades great penetration of communications to all the production sectors into society and the mechanisms of governess and mass media. However, the tremendous evolution is realized the very last years via the development of wireless communicat ions and the corresponding technologies that arise through arduous and extensive research. Mobile telephony, wireless networks, fast internet access anywhere and anytime, are technologies that has changed drastically and unreservedly our lives to the better. In this thesis, entitled “Investigation of Technical Parameters for Optimal design of WiFi Technology Systems”, after fully studying the 802.11 protocol, commonly referred as WiFi, regarding to its architecture, its structure, and its various versions, we proceed to a study of the theoretical indoor propagation models of electromagnetic radiation, in order to examine then such a complex environment and the behavior of the protocol for a specific frequency. Through modeling and simulation, we estimate and evaluate the factors that affect the propagation, but also any potential new information that may arise. The first chapter introduces to the reader the field of wireless communications and provides a historical overview of the basic wireless communication setups. In chapter two, protocol 802.11 is fully presented. Its architecture, its structure and its physical layer with the employed transmission techniques by its various predominant versions and also the functions of the MAC layer and its parameters are described. Chapter three discusses the transmission methods and the signal attenuation effect, with emphasis on the models that describe the electromagnetic transmission in enclosed spaces, as these models are used for the evaluation of the experimental part of this thesis. Chapter four contains the experimental part of this thesis and presents the topology and the exact procedure of the measurement setup. The obtained measurements are compared to the predicted ones using existing theoretical models via simulations that performed in Matlab and the prediction error is then computed and discussed. In the last chapter, we present the general conclusions derived from the measurement procedure, we evaluate the factors that contributed to the derivation of our results and we determine the most appropriate model for the environment in which we worked.