DOCSLIB.ORG

አዳማ ሳይንስና ቴክኖሎጂ ዩኒቨርሲቲ Adama Science and Technology University School of Electrical Engineering and Computing Department of Electronics and Communication Engineering

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
አዳማ ሳይንስና ቴክኖሎጂ ዩኒቨርሲቲ Adama Science and Technology University School of Electrical Engineering and Computing Department of Electronics and Communication Engineering አዳማ ሳይንስና ቴክኖሎጂ ዩኒቨርሲቲ Adama Science and Technology University School of Electrical Engineering and Computing Department of Electronics and Communication Engineering Performance Analysis of Radio Frequency Propagation Models in UMTS Network (a case study on Adama city) By Firew Tadele A thesis Submitted to School of Electrical Engineering & computing in partial fulfillment of the requirements for the degree of Master of Science, in Communication Engineering Advisor: Dr. M. Venkata Raghuvandra ADAMA, ETHIOPIA June 2017 Declaration I hereby declare that the work which is being presented in the thesis entitled, Performance Analysis of Radio Frequency Propagation Models in UMTS Network in Adama city, submitted to Adama Science and Technology University (ASTU) in partial fulfillment of the requirements for the degree Master of Science in Communication Engineering, is the result of my own research carried out under the supervision of Dr. M.Venkata Raghuvandra and all material used and reproduced has been properly referenced. Name of candidate: Firew Tadele Signature: Date: This is to declare that the above statement made by the candidate is correct and true to the best of my knowledge. Signature: Date: Performance Analysis of RF Propagation Models in UMTS Network in Adama City Page i Performance Analysis of Radio Frequency Propagation Models in UMTS Network (a case study on Adama city) Submitted by: Firew Tadele _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Student Signature Date Approved by: Dr. M.Venkata Raghuvandra _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Advisor Signature Date − − − − − − − − − − − − − − − − − − −−− − −− Internal Examiner Signature Date − − − − − − − − − − − − − − − − − − −−− −− External Examiner Signature Date − − − − − − − − − − − − − − − − − − −−− −− Chairman, Department Signature Date Graduate Committee − − − − − − − − − − − − − − − − − − −−− −− Dean, SoEEC Signature Date Performance Analysis of RF Propagation Models in UMTS Network in Adama City Page ii Abstract This thesis shows an analysis about RF signal propagation models in Third Generation mobile networks, their access medium is Wideband Code Division Multiple Access. The research includes field measurements and the choice of six propagation models with technological and environment of the test area. With a computer algorithm, select one of six outdoor propagation models for the study area and compared results of field measurements versus selected models. The study was made in an environment with a high population density and a high demand of data traffic (urban areas), suburban and rural areas of Adama city; selected twelve Base Stations (Nodes B) out off this four Node B‟s for urban areas, four for suburban and four for rural areas in a test area with the objective of observe real behavior of signal transmitted versus ideal behavior of an empirical method. The observed result of the measured path loss compared with other existing path loss prediction methods and found that the Okumura-Hata model path loss values were closest of all the propagation models considered classifying the environment into consideration. Thus, the performance of Okumura-Hata model shows its suitability for path attenuation loss prediction in UMTS networks in Adama city. The Lee model also has the least path loss for all of the chosen RF propagation models, but it‟s mainly applied for the operating frequency of 900 MHz not 2100 MHz and this model specially applied for rural areas and Adama city is one of the fastest growing cities of the country. Performance Analysis of RF Propagation Models in UMTS Network in Adama City Page iii Acknowledgments First and foremost, I would like to offer my sincerest gratitude to my advisor Dr. M.Venkata Raghuvandra), who has supported me throughout my thesis and encouraging me to work in my own way, and given me the freedom to research issues i have found relevant. This thesis would not have been possible without the help of him. I wish to express my deep and sincere gratitude to Ethio-telecom staffs Melese, Tilmo, Zeleke Demeke and My friend Elias Desalegn from ASTU for their unconditional support, productive ideas and discussions throughout this work and also Ericsson staffs for providing important data that are needed in this work. Finally I would like to express my special thanks to my families, my wife and friends who always motivate and support me to complete this thesis, and I am thankful for those who stood by me throughout my work, giving me encouragements and valuable help. Performance Analysis of RF Propagation Models in UMTS Network in Adama City Page iv Contents Abstract ......................................................................................................................................... iii Acknowledgments ......................................................................................................................... iv List of Figures .............................................................................................................................. viii List of Tables ................................................................................................................................. xi List of Acronyms .......................................................................................................................... xii Chapter one ..................................................................................................................................... 1 1 Introduction ......................................................................................................................... 1 1.1 Background ......................................................................................................................... 3 1.2 Problem Statement .............................................................................................................. 5 1.3 Objective of the Thesis ........................................................................................................ 6 1.3.1 General Objective ........................................................................................................... 6 1.3.2 Specific Objective ........................................................................................................... 6 1.4 Literature Review ................................................................................................................ 7 1.5 Methodology ....................................................................................................................... 9 1.5.1 Theoretical study ............................................................................................................ 9 1.5.2 Data collection .............................................................................................................. 10 1.5.3 Simulation and experimental result ............................................................................... 10 1.6 Scope of the Thesis............................................................................................................ 11 1.7 Thesis outline .................................................................................................................... 11 Chapter Two ................................................................................................................................. 13 2 UMTS Network Overview................................................................................................. 13 2.1 Introduction ....................................................................................................................... 13 2.2 IMT2000 Frequency Band Allocation................................................................................ 17 2.3 Ethiopian Frequency Distribution ...................................................................................... 18 2.4 WCDMA Services ............................................................................................................. 19 2.4.1 Categories of 3G Services ............................................................................................. 19 2.4.2 Features of 3G Services ................................................................................................ 19 2.5 UMTS System Structure .................................................................................................... 20 2.6 UMTS Network System Composition................................................................................ 21 2.6.1 Basic Structure of UMTS Terrestrial Radio Access Network (UTRAN) ........................ 25 Performance Analysis of RF Propagation Models in UMTS Network in Adama City Page v 2.6.2 Basic Protocol Structure of UTRAN Interfaces ............................................................. 26 2.7 UMTS Radio Interface Technology ................................................................................... 27 2.7.1 Protocol Structure of Radio Interfaces ........................................................................... 28 2.7.2 Spreading Spectrum and Scrambling ............................................................................. 29 2.7.3 Logical Channel ............................................................................................................ 31 2.7.4 Transport Channel ........................................................................................................ 32 2.8 Fundamentals of the UMTS Technology ..........................................................................
Load more

Recommended publications
  • Outdoor Propagation Models-Comparison Literature Review
    International Journal of Electronics Communication and Computer Engineering a Volume 4, Issue 3, ISSN (Online): 2249–071X, ISSN (Print): 2278–4209 Outdoor Propagation Models-Comparison Literature Review Mr. Umesh Yadav Department of Wireless and Mobile Communication GRD-IMT, Rajpur Road Dehradun, India Email: [email protected] Abstract - The aim of comparing different outdoor like: adhoc wireless network, wireless sensor network, propagation models is to study the earlier introduced models mobile communications etc. Between the two extremes of in the present environment of RF technology and present & past times, the mid-time arena have seen requirement. In the present era of telecom services coverage development of various propagation models like: Line of is not enough but we need to introduce cellular network with sight, okumura-Hata, cost etc. In order to facilitate better high quality parameters. In this comparison review we will focus on the type of terrain/ environment which will best suit planned & resource specific developments for the bet the different outdoor propagations models. HHHterment of QOS. This period of time also noticed several developments in the field estimation path loss in Keywords - Pathloss, Attenuation, Optimization, Antenna different propagation scenario profiles deploying variable Gain, Interference. modelling strategies. I. INTRODUCTION II. RADIO PROPAGATION The ability to communicate with people on the move has A. Types of Radio wave propagation mechanisms evolved remarkably since Guglielmo Marconi first To study and understand the modelling of radio wave demonstrated radio‟s ability to provide continuous contact propagation, it is first required to know the basics of its with ships sailing the English Channel. That was in year propagation mechanism.
    [Show full text]
  • Introduction to Rf Propagation
    INTRODUCTION TO RF PROPAGATION John S. Seybold, Ph.D. ,WILEY- 'iNTERSCIENCE JOHN WILEY & SONS, INC. CONTENTS Preface XIII 1. Introduction 1.1 Frequency Designations 1 1.2 Modes of Propagation 3 1.2.1 Line-of-Sight Propagation and the Radio Horizon 3 1.2.2 Non-LOS Propagation 5 1.2.2.1 Indirect or Obstructed Propagation 6 1.2.2.2 Tropospheric Propagation 6 1.2.2.3 Ionospheric Propagation 6 1.2.3 Propagation Effects as a Function of Frequency 9 1.3 Why Model Propagation? 10 1.4 Model Selection and Application 11 1.4.1 Model Sources H 1.5 Summary 12 References 12 Exercises 13 2. Electromagnetics and RF Propagation 14 2.1 Introduction 14 2.2 The Electric Field 14 2.2.1 Permittivity 15 2.2.2 Conductivity 17 2.3 The Magnetic Field 18 2.4 Electromagnetic Waves 20 2.4.1 Electromagnetic Waves in a Perfect Dielectric 22 2.4.2 Electromagnetic Waves in a Lossy Dielectric or Conductor 22 2.4.3 Electromagnetic Waves in a Conductor 22 2.5 Wave Polarization 24 2.6 Propagation of Electromagnetic Waves at Material Boundaries 25 2.6.1 Dielectric to Dielectric Boundary 26 vii VÜi CONTENTS 2.6.2 Dielectric-to-Perfect Conductor Boundaries 31 2.6.3 Dielectric-to-Lossy Dielectric Boundary 31 2.7 Propagation Impairment 32 2.8 Ground Effects on Circular Polarization 33 2.9 Summary 35 References 36 Exercises 36 3. Antenna Fundamentals 38 3.1 Introduction 38 3.2 Antenna Parameters 38 3.2.1 Gain 39 3.2.2 Effective Area 39 3.2.3 Radiation Pattern 42 3.2.4 Polarization 44 3.2.5 Impedance and VSWR 44 3.3 Antenna Radiation Regions 45 3.4 Some Common Antennas 48 3.4.1 The Dipole 48 3.4.2 Beam Antennas 50 3.4.3 Hörn Antennas 52 3.4.4 Reflector Antennas 52 3.4.5 Phased Arrays 54 3.4.6 Other Antennas 54 3.5 Antenna Polarization 55 3.5.1 Cross-Polarization Discrimination 57 3.5.2 Polarization Loss Factor 58 3.6 Antenna Pointing loss 62 3.7 Summary "3 References "4 Exercises "5 4.
    [Show full text]
  • Radio Propagation Modeling on 433 Mhz
    Radio propagation modeling on 433 MHz Ákos Milánkovich1, Károly Lendvai1, Sándor Imre1, Sándor Szabó1 1 Budapest University of Technology and Economics, Műegyetem rkp. 3-9. 1111 Budapest, Hungary {milankovich, lendvai, szabos, imre}@hit.bme.hu Abstract. In wireless network design and positioning it is essential to use radio propagation models for the applied frequency and environment. There are many propagation models available for both indoor and outdoor environments; however, they are not applicable for 433 MHz ISM frequency, which is perfectly suitable for smart metering and sensor networking applications. During our work, we gathered the most common propagation models available in scientific literature, broke them down to components and analyzed their behavior. Based on our research and measurements, a method was developed to create a propagation model for both indoor and outdoor environment optimized for 433 MHz frequency. The possible application areas of the proposed models: smart metering, sensor networks, positioning. Keywords: Radio propagation model, 433 MHz, smart metering, positioning 1 Introduction We are accustomed to use various wirelessly communicating devices, which possess different transmission properties according to their application areas. There are devices operating at high bandwidth in short range, but can not percolate walls. On the contrary, other devices can penetrate all kinds of materials for long distances, but operate on lower bandwidth. The transmission properties of these various technologies – beyond transmission power and antenna characteristics – are principally determined by the operating frequency range of the system. In addition, the operating frequency determines the amount of attenuation for the technology, caused by different media. The ability of calculating the signal strength in a given distance from the transmitter is severely important in case of network planning, because such a model helps us to determine where to place the devices, so that the system operates properly.
    [Show full text]
  • Radio Coverage Prediction for a Wireless IP-Based Network in Central Europe
    Radio Coverage Prediction for a Wireless IP-based Network in Central Europe Ralf Wilke DH3WR, Hubertus A. Munz and Dirk Heberling Institute of High Frequency Technology RWTH Aachen University Aachen, Germany [email protected] Abstract—In the beginning of 2009 the idea of building up a point-to-point radio links are displayed on a map. An excerpt wireless IP-based data network emerged from Austria. The of this map is shown in Fig. 1. classical backbone approach with distributed locations of routers, servers and user access equipment was pursued. Today in 2014, the network is covering Central Europe and still spreading. Every week new backbone interconnections and user access points are being installed. Based on an open source framework, a wiki-like website serves as an administrative platform, where IP assignments, meta-data and geographical locations of backbone nodes are stored. This paper presents the selection and implementation of RF propagation models to automatically predict the radio coverage area of user access points and display them on a map. As the RF path lengths differ from 300 m up to 30 km, several models where reviewed and merged into one software. The prediction was done based on a digital elevation model and land cover data. Keywords—RF prediction, wireless user access, coverage, HamNet I. INTRODUCTION In the 2009 the Austrian amateur radio community started to build up a wireless network. The frequencies used are in the 2.4 GHz and 5.7 GHz WiFi band. Due to the fact that the operators are licensed radio amateurs, the EIRP of those installations is not limited to the regulations which apply for Fig.
    [Show full text]
  • Terrestial VHF / UHF Signal Strength Levels in Eastern Obolo and Ikot Abasi Communities of Akwa Ibom State, Nigeria
    IOSR Journal of Electronics and Communication Engineering (IOSR-JECE) e-ISSN: 2278-2834,p- ISSN: 2278-8735.Volume 14, Issue 5, Ser. I (Sep.-Oct. 2019), PP 12-25 www.iosrjournals.org Terrestial VHF / UHF Signal Strength Levels in Eastern Obolo and Ikot Abasi Communities of Akwa Ibom State, Nigeria Aniefiok Otu Akpan Physics Department, Akwa Ibom State University, Nigeria Corresponding Author: Aniefiok Otu Akpan Abstract: Signal strength levels from Akwa Ibom Broadcasting Corporation (AKBC) television (Channel 45) and Nigerian Television Authority (NTA) channel 12 have been measured with a view to establishing the primary, secondary and fringe service areas of these signals at some locations in Eastern Obolo and Ikot Abasi Local Government Areas of Akwa Ibom State. Eastern Obolo and Ikot Abasi are densely forest zones that empty into the creeks that lead to the Atlantic Ocean in Akwa Ibom State. Propagation of electromagnetic waves in these areas has been quite challenging. CATV was used to measure signals of the TV station in dB, dBµv and dBmv. Signals received from this TV station at different locations of the study area using Radio Frequency Analyser with 24 channels spectrum ranging from 46-870MHz and an outdoor television antenna, 59(L) x 8.5(W) x 11(H) on a 10m pole showed that the signal strength received from VHF channel 45 ranged from 22dBµv to 51dBµv in Ikot Abasi and Eastern Obolo. 31.5dBµv signal was received by more than 55% of the area covered but others, especially the rural communities had signal below this value. In terms of path loss prediction, this closely agreed with Egli model when comparing the standard and calculated path loss.
    [Show full text]
  • Propagation of IEEE802.15.4 in Vegetation
    Proceedings of the World Congress on Engineering 2011 Vol II WCE 2011, July 6 - 8, 2011, London, U.K. Propagation of IEEE802.15.4 in Vegetation Pedro Mestre Member, IAENG, Jose´ Ribeiro, Carlos Serodio Member, IAENG, Joao˜ Monteiro Abstract— Data communications and more specifically field, it must be taken into account all the parameters that wireless data communications have an increasing role in may have influence in the propagation of electromagnetic precision agriculture. ZigBee is one of the most widely adopted waves. Wireless Sensor Network (WSN) technology, and it operates on top of IEEE802.15.4 that provides the two lower layers A protocol which has a wide adoption by the Wireless of the OSI model. To optimize the placement of sensors in Sensor Networks developers community [5] is ZigBee [6]. agricultural explorations (greenhouses, crop fields, ...), besides It is considered one of the most promising standards for placing the sensors the nearer as possible to the process to wireless sensors [7] for use in agricultural applications. monitor, also the maximum distance between nodes must be ZigBee implements the upper layer of the OSI (Open taken into account. The maximum distance between wireless nodes depends on the gain of the antennas, output power of Systems Interconnection) reference model for data the transmitter and attenuation, either in free-space and due communications, and it relies on the IEEE802.15.4 [8] to obstacles. Normally propagation models are used to evaluate protocol for the implementation of the two lower layers, the values of attenuation. However the traditional propagation i.e., the Physical Layer and the Data Link Layer.
    [Show full text]
  • Introduction to Rf Propagation
    INTRODUCTION TO RF PROPAGATION John S. Seybold, Ph.D. JOHN WILEY & SONS, INC. INTRODUCTION TO RF PROPAGATION INTRODUCTION TO RF PROPAGATION John S. Seybold, Ph.D. JOHN WILEY & SONS, INC. Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved Published by John Wiley & Sons, Inc., Hoboken, New Jersey Published simultaneously in Canada No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 750-4470, or on the web at www.copyright.com. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, or online at http://www.wiley.com/go/permission. Limit of Liability/Disclaimer of Warranty: While the publisher and author have used their best efforts in preparing this book, they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives or written sales materials. The advice and strategies contained herein may not be suitable for your situation.
    [Show full text]
  • Propagation Models
    RADIO PROPAGATION Propagation Ways Propagation Models Path Loss Calculation Engr. Mian Shahzad Iqbal Lecturer Department of Telecommunication Engineering What is propagation? How radio waves travel between two points. They generally do this in four ways: Directly from one point to another Following the curvature of the earth Becoming trapped in the atmosphere and traveling longer distances Refracting off the ionosphere back to earth. Speed, Wavelength, Frequency Light speed = Wavelength x Frequency = 3 x 108 m/s = 300,000 km/s System Frequency Wavelength AC current 60 Hz 5,000 km FM radio 100 MHz 3 m Cellular 900 MHz 33.3 cm Ka band satellite 20 GHz 15 mm Ultraviolet light 1015 Hz 10-7 m Types of Waves Ionosphere (80 - 720 km) Sky wave Mesosphere (50 - 80 km) Space wave Stratosphere (12 - 50 km) Ground wave r itte Rece Troposphere ransm iver T (0 - 12 km) Earth Radio Frequency Bands Classification Band Initials Frequency Range Characteristics Extremely low ELF < 300 Hz Infra low ILF 300 Hz - 3 kHz Ground wave Very low VLF 3 kHz - 30 kHz Low LF 30 kHz - 300 kHz Medium MF 300 kHz - 3 MHz Ground/Sky wave High HF 3 MHz - 30 MHz Sky wave Very high VHF 30 MHz - 300 MHz Ultra high UHF 300 MHz - 3 GHz Super high SHF 3 GHz - 30 GHz Space wave Extremely high EHF 30 GHz - 300 GHz Tremendously high THF 300 GHz - 3000 GHz Propagation Mechanisms Reflection Propagation wave impinges on an object which is large as compared to wavelength - e.g., the surface of the Earth, buildings, walls, etc.
    [Show full text]
  • 4 Rf Propagation Models in Lte
    Performance Analysis and Comparison of Radio Frequency Propagation Models for Outdoor Environments in 4G LTE Network Asad Saeed Habib Ur Rehman Muhammad Hassan Masood This thesis is presented as part of the Degree of Master of Sciences in Electrical Engineering Blekinge Institute of Technology 2013 School of Engineering Blekinge Institute of Technology, Sweden Supervisor: Muhammad Shahid Examiner: Benny Lövström 1 Page Left Blank Intentionally 2 Abstract The dissertation concerns about the path loss calculation of Radio Frequency (RF) propagation models for 4G Long Term Evolution (LTE) Network to prefer the best Radio Frequency propagation model. The radio propagation models are very significant while planning of any wireless communication system. A comparative analysis between radio propagation models e.g. SUI model, Okumura model, Cost 231 Hata Model, Cost 231-Walfisch Ikegami and Ericsson 9999 model that would be used for outdoor propagation in LTE. The comparison and performance analysis has been made by using different geological environments e.g. urban, sub-urban and rural areas. The simulation scenario is made to calculate the lowest path loss in above defined environments by using selected frequency and height of base station antennas while keeping a constant distant between the transmitter and receiver antennas. i Dedication To our Parents and Teachers who motivated and encouraged us to attain this Hallmark in the best way ii Acknowledgment Our thesis was an endeavour, much greater in magnitude than any of projects we have ever done. To see this endeavor turn into accomplishment was a dream that would have never come true without the support of many individuals.
    [Show full text]
  • Radio Propagation Modeling on 433 Mhz Ákos Milánkovich, Károly Lendvai, Sándor Imre, Sándor Szabó
    Radio Propagation Modeling on 433 MHz Ákos Milánkovich, Károly Lendvai, Sándor Imre, Sándor Szabó To cite this version: Ákos Milánkovich, Károly Lendvai, Sándor Imre, Sándor Szabó. Radio Propagation Modeling on 433 MHz. 18th European Conference on Information and Communications Technologies (EUNICE), Aug 2012, Budapest, Hungary. pp.384-395, 10.1007/978-3-642-32808-4_35. hal-01543157 HAL Id: hal-01543157 https://hal.inria.fr/hal-01543157 Submitted on 20 Jun 2017 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution| 4.0 International License Radio propagation modeling on 433 MHz Ákos Milánkovich1, Károly Lendvai1, Sándor Imre1, Sándor Szabó1 1 Budapest University of Technology and Economics, Műegyetem rkp. 3-9. 1111 Budapest, Hungary {milankovich, lendvai, szabos, imre}@hit.bme.hu Abstract. In wireless network design and positioning it is essential to use radio propagation models for the applied frequency and environment. There are many propagation models available for both indoor and outdoor environments; however, they are not applicable for 433 MHz ISM frequency, which is perfectly suitable for smart metering and sensor networking applications. During our work, we gathered the most common propagation models available in scientific literature, broke them down to components and analyzed their behavior.
    [Show full text]
  • My Supervisor Who Coached Me Through This Research and Helped Along the Way " Friends Who Helped " the Several Specific People Here Who Have Given Advice
    Dedication I'm thanking: " God " My grandparents and extended family " My supervisor who coached me through this Research and helped along the way " Friends who helped " The several specific people here who have given advice i Acknowledgement Deepest appreciation and sincerest gratitude and heartily thankfulness to the advisor and supervisor Dr. Abdel Rasoul Jabar Alzubaidi for his encouragement, advice and support during this Research of the PhD, who gave the moral support and guidance in different matters regarding the topic and helped a lot in gathering different information, collecting data and guiding from time to time in making this Research .Despite his busy schedules ,he had been very kind while suggesting the outlines of this Research and continuous guidance. I also wish to thank all those who helped. Without them, I could not have completed this Research. Very thankful to everyone who supported, in completing this Research effectively in time. Lastly, I offer regards and blessings to all those who supported in any respect during the completion of the Research. Last but not the least; thank to all family ii ﻣﺴﺘﺨﻠﺺ ان اﻟﺘﻘﺪم اﻟﺤﺪﯾﺚ ﻓﻲ ﻣﺠﺎل اﻻﺗﺼﺎﻻت اﻟﻼﺳﻜﯿﺔ زاد ﻣﻦ ﻛﻤﯿﺔ اﻟﻤﻌﻠﻮﻣﺎت اﻟﺘﻲ ﯾﺘﻢ ﻣﻌﺎﻟﺠﺘﮭﺎ ﻓﻲ وﻗﺖ ﻣﺤﺪد ﺑﻮاﺳﻄﺔ اﻟﺸﺒﻜﺎت اﻟﻼﺳﻠﻜﯿﺔ وان اﻻﻋﺘﻤﺎد ﻋﻠﻲ اﺳﺘﺨﺪام اﻟﻘﻨﻮات اﻟﻼﺳﻜﯿﺔ زاد اﺳﺘﺨﺪاﻣﮫ , وﻛﺬﻟﻚ اْﻧﺘﺸﺎراﺷﺎره اﻟﺘﻠﻔﻮن اﻟﻤﺤﻤﻮل ﺧﻼل اﻟﻘﻨﻮات اﻟﻼﺳﻠﻜﯿﮫ ﺗﺸﻜﻞ ﻇﻮاھﺮ ﻣﺘﻌﺪده اﻟﺘﻌﻘﺪ ﻣﺜﻞ ﻇﺎھﺮه اﻟﺨﻔﻮت. و ان اﻟﻌﻤﻠﯿﺎت اﻟﺮﯾﺎﺿﯿﮫ اﻟﺪﻗﯿﻘﮫ ﺗﺤﻮل ھﺬه اﻟﻈﺎھﺮه ﻣﻦ ﻣﻌﻘﺪه اﻟﻲ ﻗﺎﺑﻠﮫ ﻟﻠﺘﺤﻠﯿﻞ واﻟﺘﻌﻠﻢ ﻓﻲ ﻣﺠﺎل اﻻﺗﺼﺎﻻت . وھﻨﺎﻟﻚ ﻣﺠﮭﻮدات ﻛﺜﯿﺮه ﺑﺬﻟﺖ ﻓﻲ اﻟﻨﻤﺬﺟﮫ اﻻﺣﺼﺎﺋﯿﮫ وﻛﺎﻧﺖ ﻧﺘﯿﺠﺘﮭﺎ اﻟﺤﺼﻮل ﻋﻠﻲ ﻃﺮﯾﻘﮫ اﺣﺼﺎﺋﯿﮫ ﻣﻨﻀﺒﻄﮫ ﻟﻠﻨﻤﺬﺟﮫ ﻓﻲ اﻟﺨﻔﻮت اﻟﺘﻲ ﺗﻌﺘﻤﺪ ﻋﻠﻲ اﻻﻧﺘﺸﺎر ﻓﻲ اﻟﺒﯿﺌﮫ وﻟﻜﻦ ﻓﻲ ﻧﻔﺲ اﻟﻮﻗﺖ ھﻨﺎﻟﻚ ﺗﺤﺪﯾﺎت واﺟﮭﺖ اﻻﺗﺼﺎﻻت اﻟﻼﺳﻠﻜﯿﺔ وھﻲ اﻟﺤﻮﺟﺔ اﻟﻲ ﻣﻌﺪل ﻣﻌﻠﻮﻣﺎت ﻋﺎﻟﯿﺔ وﻧﻮﻋﯿﺔ ﺟﻮدة اﻟﺨﺪﻣﺔ وﻗﺎﺑﻠﯿﺔ اﻟﺤﺮﻛﺔ و اﻟﺘﻨﻘﻞ واﻟﺮﺑﻂ ﻓﻲ اﻟﺸﺒﻜﺎت اﻟﻼﺳﻠﻜﯿﺔ وﻣﺸﻜﻠﮫ اﻟﺘﺪاﺧﻞ ﺑﯿﻦ اﻟﻤﺘﺤﺪﺛﯿﻦ ﻣﻊ ﺑﻌﻀﮭﻢ اﻟﺒﻌﺾ و اﻟﺨﻔﻮت و ﺳﺮﯾﺔ وﺣﻔﻆ اﻟﻤﻌﻠﻮﻣﺎت.
    [Show full text]
  • Performance Evaluation of Channel Propagation Models and Developed Model for Mobile Communication
    American Journal of Applied Sciences Original Research Paper Performance Evaluation of Channel Propagation Models and Developed Model for Mobile Communication 1,2Yahia Zakaria 1Department of Electrical Engineering, Faculty of Electrical Engineering and Computer Science, VSB-Technical University of Ostrava, 17.Listopadu 15, 70833 Ostrava, Czech Republic 2Engineering Research Division, National Research Centre (NRC), Dokki, P.O. 12622, Cairo, Egypt Article history Abstract: Propagation models represent a solidifying of mathematical Received: 06-12-2016 equations and algorithms that are used for radio signal propagation Revised: 17-02-2017 prediction in specific regions. In this research different propagation models Accepted: 18-02-2017 are analyzed and compared. These propagation models have been proposed at the operating frequency of 3.8 GHz for different transmitter antenna Corresponding Author: Yahia Zakaria heights in all types of terrain. These propagation models depend on Department of Electrical location, frequency range and clutter type such as urban, suburban and Engineering, Faculty of countryside. We have to bear in mind that the results of the path loss Electrical Engineering and estimation of Free Space model are identical and equal to (119 dB) for 18 Computer Science,VSB- m and 34 m transmitter antenna heights at 3.8 GHz in urban environment. It Technical University of is obvious that Egli model shows the highest path loss values in rural Ostrava, 17, listopadu 15, environment as compared with the other models. By the end of this paper, a 70833 Ostrava, Czech Republic developed empirical radio propagation model is proposed to be appropriate Emails: [email protected] in urban and rural environments.
    [Show full text]