This document provides an overview of microwave communication. It discusses various topics related to microwave communication including possible media, manufacturers, advantages of microwave, characteristics, types of links and systems. It also covers topics such as line of sight requirements, wave propagation, multipath propagation, path loss, antenna types and gains. The document discusses concepts like fade margin, reliability and signal to noise ratio which are important in microwave system design. It provides examples of calculating free space loss and fresnel zone radius.
The new 5G unified air interface is being designed to not only vastly enhance mobile broadband performance and efficiency, but also scale to connect the massive Internet of Things and enable new types of services such as mission critical control that require ultra-low latency and new levels of reliability and security. The new design will unify diverse spectrum types and bands, scale from macro deployments to local hotspots and efficiently multiplex the envisioned 5G services across an extreme variation of requirements.
For more information on 5G technologies, use cases and timelines, please visit us at www.qualcomm.com/5G.
The new 5G unified air interface is being designed to not only vastly enhance mobile broadband performance and efficiency, but also scale to connect the massive Internet of Things and enable new types of services such as mission critical control that require ultra-low latency and new levels of reliability and security. The new design will unify diverse spectrum types and bands, scale from macro deployments to local hotspots and efficiently multiplex the envisioned 5G services across an extreme variation of requirements.
For more information on 5G technologies, use cases and timelines, please visit us at www.qualcomm.com/5G.
TRANSMISSION :
A PROCESS WHERE TRAFFIC (VOICE,DATA,VIDEO) IS DESPATCHED OVER A MEDIUM BETWEEN THE SOURCE AND THE DESTINATION
TYPES OF TRANSMISSION MEDIA :
WIRED TRANSMISSION MEDIA
1.COPPER CABLE
2.OPTICAL FIBER
WIRELESS TRANSMISSION MEDIA
1.VSAT NETWORKS
2.MICROWAVE RADIO
Improvement of Fading Channel Modeling Performance for Wireless Channel IJECEIAES
Fading channel modeling is generally defined as the variation of the attenuation of a signal with various variables. Time, geographical position, and radio frequency which is included. Fading is often modeled as a random process. Thus, a fading channel is a communication channel that experiences fading. In this paper, the proposed system presents a new design and simulate a wireless channel using Rayleigh channels. Rayleigh channels using two approaches (flat and frequency-selective fading channels) in order to calculate some path space loss efforts and analysis the performance of different wireless fading channel modeling. The results show that the bite error rate (BER) performance is dramatically improved in the value of signal to noise ratio (SNR) is equal to 45dB. Finally, the experimental results show that the proposed method enhances the performance of fading channel modeling by reducing the error of BER when the SNR is reduced also. Moreover, the more accurate model is Rayleigh model which can be considered for developing fading channel model.
Empirical Determination of Locations of Unstable and Blank Gsm Signal Network...IJERA Editor
In a GSM network coverage area there exist locations where network signal reception is always either unsteady or blank. These problems are the cause of intermittent call receptions or no network reception at some locations in cell sites. This paper discusses a practical work carried out in a cell site located in a remote area in Eastern Nigeria to determine such locations. To do that, received signal field strength measurements were initially conducted at 3m interval starting from 100m away from the base Station to determine the suspected locations of unsteady and blank network receptions in the field. Further extensive measurements were then taken at each of the suspect locations. Analyses of the data obtained shows that a lot of such phenomenon may exist in cell sites.
Module 1: Introduction Lectures 8 hrs.
Fundamentals of wireless communication technology – the electromagnetic spectrum – radio
propagation mechanisms – characteristics of the wireless channel – Mobile Ad-hoc Networks
(MANETS) and Wireless Sensor Networks (WSNs): concepts and architectures. Applications
of Ad-hoc and sensor networks. Design challenges in Ad-hoc and sensor networks.
Determination of Propagation Path Loss and Contour Map for FUTA FM Radio Fede...IOSR Journals
Abstract: FM signal propagation through the troposphere interacts with the terrain as obstacles and reflection planes. To understand the degree of interaction, signal strength measurements of the 93.1MHz frequency modulated Radio located at Federal University of Technology; Akure, Nigeria was carried out in the area surrounding the station. The paper reviews the various models for predicting transmission loss and employed the long rice irregular terrain model for its versatility for the study. The losses along the paths were determined and this was compared with the path loss predicted by the irregular terrain model and this was highly correlated. The result offers useful data for developing the contour map of the propagation loss which was developed for the station. It was concluded that with the irregular terrain model predictions can be used for accurate spectrum management in Nigeria. Keywords: Signal Strength, Transmission Loss, Terrain, Spectrum Management.
Similar to Training on microwave communication (20)
Basic Telecom concepts
Various Wireless Technologies
Cellular concepts & Principal of cellular Comm.
GSM Network Architecture
GSM channel Architecture
Call Flows in GSM
GSM Planning steps (Nominal Plan & RF surveys)
Alternative means of wireless communication
Walkie - Talkie
Pagers
Trunked private radios
Mobile Phone - the magic technology that enables everyone to communicate anywhere with anybody.
Till 1982 Cellular Systems were exclusively Analog Radio Technology.
Advanced Mobile Phone Service (AMPS)
U.S. standard on the 800 MHz Band
Total Access Communication System (TACS)
U.K. standard on 900 MHz band
Nordic Mobile Telephone System (NMT)
Scandinavian standard on the 450 & 900 MHz band
The GSM standard was developed by the Groupe SpecialMobile, which was an initiative of the Conference of European Post and Telecommunications (CEPT) administrations.
The responsibility for GSM standardization now resides with the
Special Mobile Group (SMG) under the European Telecommunication Standard Institute (ETSI).
Fully digital system utilizing the 900MHz frequency band.
TDMA over radiocarriers(200 kHz carrier spacing)
8 full rate or 16 half rate TDMA channels per carrier
User/terminal authentication for fraud control
Encryption of speech and data transmissions over the radio path
Full international roaming capability
Low speed data services (upto 9.6kb/s)
Compatibility with ISDN for supplementary services
Support of short message services(SMS)
GSM supports a range of basic and supplementary services, and these services are defined analogous to those for ISDN(i.e.,bearer services, teleservices, and supplementary services).
The most important service supported by GSM is Telephony.
Other services derived from telephony included in the GSM specification are emergency calling and voice messaging.
Bearer services supported in GSM include various asynchronous and synchronous data services for information transfer.
Teleservices based on these bearer services include group 3 fax and short message service(SMS)
The data capabilities of GSM have now been enhanced to include high speed circiut-switched data(HSCSD) and general packet radio service (GPRS).
Call offering services call forwarding
Call resrtiction services call barring
Call waiting service
Call hold service
Multi party service tele conferencing
Calling line presentation restriction services
Advice of charge service
Closed user group service
The GSM System comprises of Base Transceiver Station (BTS), Base Station Controllers (BSC), Mobile Switching Centers (MSC), and set of registers (databases) to assist in mobility management and security functions.
All signaling between the MSC and the various registers (databases) as well as between the MSCs takes place using the Signaling System 7(SS7) network, with the application level messages using the Mobile Application Protocol (MAP) designed specifically for GSM.
The MAP protocol utilizes the lower layer functions from the SS7 protocol stack.
FREQUENCY CONCEPTS
The following table summarizes the frequency-related specifications of each of the GSM systems. The terms used in the table are explained in the remainder of this section.
System P-GSM 900 E-GSM 900 GSM 1800
Frequencies: • Uplink • Downlink
890-915 MHz
935-960 MHz
Wavelength ~ 33 cm
880-915 MHz
925-960 MHz
GSM 1900
1710-1785 MHz
1805-1880 MHz
1850-1910 MHz
1930-1990 MHz
~ 33 cm ~ 17 cm ~ 16 cm
Bandwidth 25 MHz
35 MHz 75 MHz 60 MHz
Duplex Distance 45 MHz
45 MHz 95 MHz 80 MHz
Carrier Separation 200 kHz
1
Radio Channels
200 kHz 200 kHz 200 kHz
125
175 375 300
Transmission Rate 270 kbits/s
270 kbits/s 270 kbits/s 270 kbits/s
Table 3-1 Frequency-related specifications
FREQUENCY
F Did you know?
Due to frequency, a BTS transmitting information at 1800 MHz with an output power of 10 Watts (W) will cover only half the area of a similar BTS transmitting at 900 MHz. To counteract this, BTSs using 1800 MHz may use a higher output power.
An MS communicates with a BTS by transmitting or receiving radio waves, which consist of electromagnetic energy. The frequency of a radio wave is the number of times that the wave oscillates per second. Frequency is measured in Hertz (Hz), where 1 Hz indicates one oscillation per second. Radio frequencies are used for many applications in the world today. Some common uses include:
• Television: 300 MHz approx. • FM Radio: 100 MHz approx. • Police radios: Country dependent • Mobile networks: 300 - 2000 MHz approx.
The frequencies used by mobile networks varies according to the standard being used
2
. An operator applies for the available frequencies or, as in the United States, the operator bids for frequency bands at an auction. The following diagram displays the frequencies used by the major mobile standards:
DAMPS 1900 MHz
0450900800 1500 1800 1900 NMT 450
PDC 800
GSM 900 GSM 1800 GSM 1900NMT 900
PDC 1500AMPS DAMPS 800
TACS
Figure 3-1 Frequencies for major mobile standards
Full rate => Used for speech at 13 Kbits/s
or sending data at 9.6 Kbits/s
Half rate => Used for speech at 6.5 Kbits/s
or sending data at 4.8 Kbits/s
Enhanced Full rate => Used for speech at 13 Kbits/s
or sending data at 9.6 Kbits/s but
with almost Land line quality
FCCH = FREQUENCY CORRECTION CHANNEL
=> To tell the Mobile that this is the BCCH carrier
=> To able the Mobile to synchronize to the frequency
(Downlink only)
SCH = SYNCHRONISATION CHANNEL
=> Used for sending BSIC (Base station Identity Code)
=> Give TDMA frame number to the Mobile.
(Downlink only)
BCCH = BROADCAST CONTROL CHANNEL
=> Used for sending information to the mobile like
CGI (Cell Global identity), LAI (Location Area Identity),
BCCH carriers of the neighboring cells,
maximum output power allowed in the cell and other
broadcast messages like barred cell. (Downlink only)
PCH = PAGING CHANNEL
=> Used for paging the Mobile. (Downlink only)
Reason could be an incoming call or an incoming Short Message.
RACH = RANDOM ACCESS CHANNEL
=> Used for responding to the paging (terminating), Location updating
or to make call access (originating) by asking for a signaling channel.
(Uplink only)
AGCH = ACCESS GRANT CHANNEL
=> Used to allocate SDCCH to the mobile.
(Downlink only)
ell Allocation (CA) is the subset of the total frequency band that is available for one BTS. It can be viewed as the total transport resource available for traffic between the BTS and its attached MSs. One Radio Frequency CHannel (RFCH) of the CA is used to carry synchronization information and the Broadcast Control CHannel (BCCH). This can be any of the carriers in the cell and it is known as the BCCH carrier or the c
carrier. Strong efficiency and quality requirements have resulted in a
0
rather complex way of utilizing the frequency resource. This chapter describes the basic principles of how to use this resource from the physical resource itself to the information transport service offered by the BTS.
Carrier separation is 200 kHz, which provides: • 124 pairs of carriers in the GSM 900 band • 374 pairs of carriers in the GSM 1800 band • 299 pairs of carriers in the GSM 1900 band
Using Time Division Multiple Access (TDMA) each of these carriers is divided into eight Time Slots (TS). One TS on a TDMA frame is called a physical channel, i.e. on each duplex pair of carriers there are eight physical channels.
A variety of information is transmitted between the BTS and thMS. The information is grouped into different logical channelsEach logical channel is used for a specific purpose such as paging, call set-up and speech. For example, speech is sent on the logical channel Traffic CHannel (TCH). The logical channels are mapped onto the physical channels.
The information in this chapter does not include channels specific for GPRS (General Packet Radio Service). For basic information on GPRS see chapter 14 of this documentation.
Common core mechanics in Nokia UltraSite EDGE BTS Outdoor and Nokia UltraSite EDGE BTS Indoor
Common plug-in units
1940 x 770 x 750 mm (H x W x D)
Identical footprint to CityTalk BTS
Weight
Max weight (12 TRX) 340 kg
Heaviest single part 58 kg (core mechanics)
Heaviest plug-in unit 18 kg (RTC)
Acoustic noise (max): 68 dB(A)
Climatic conditions:
w/o heater -10°C ... +50°C
with optional heater -33°C ... +50°C
Ingress Protection Class: IP 55
Two level environmental protection:
BTS core and cabinet door provides EMC shielding
Outdoor kit provides additional weather proofing
The GENEX Assistant is excellent software tool for
Post-Processing 2G & 3G Drive Test Data.
With the GENEXAssistant, you can:
Have a panorama view of network performance
Locate network troubles
Improve network quality
Verify network planning and optimization
ANALYSIS OF LOGFILE
FOR POST PROCESSING OF LOGFILE IN
GENEX ASSISTANCE WE NEED TO
OPEN A NEW PROJECT
. Overview
2. Handover Causes & Priorities
3. Threshold Comparison Process
4. Target Cell Evaluation Process
5. Handover Algorithms
Power Budget (PBGT)
Level & Quality (RXLEV & RXQUAL)
Umbrella (& Combined Umbrella/PBGT)
MS Speed (FMMS & MS_SPEED_DETECTION)
6. Imperative Handovers
Distance
Rapid Field Drop (RFD) & Enhanced Rapid Field Drop (ERFD)
7. Handover Timers
Call continuity - to ensure a call can be maintained as a MS moves geographical location from the coverage area of one cell to another
Call quality - to ensure that if an MS moves into a poor quality/coverage area the call can be moved from the serving cell to a neighbouring cell (with better quality) without dropping the call
Traffic Reasons - to ensure that the traffic within the network is optimally
distributed between the different layers/bands of a network
If 2 or more handover (PC) criteria are satisfied simultaneously the following priority list
is used in determining which process is performed;
. Uplink and downlink Interference
2. Uplink quality
3. Downlink quality
4. Uplink level
5. Downlink level
6. Distance
7. Enhanced (RFD)
8. Rapid Field Drop (RFD)
9. Slow moving MS
10. Better cell i.e. Periodic check (Power Budget HO or Umbrella HO)
11. PC: Lower quality/level thresholds (UL/DL)
12. PC: Upper quality/level thresholds (UL/DL)
Introduction
Channel Configuration
Idle Mode Operation
Protocols
Radio resources
Measurements
Power Control
HO process
Intelligent Underlay Overlay
Handover Support for Coverage Enhanchements
The extended cell
Dynamic Hotspot
Dual band GSM/DCS Network Operation
Half Rate
HSCSD
Transmission management in BSS is a feature used in managing the Base Station Subsystem transmission system functions such as supervision, alarms, statistics
and settings. The network element mainly responsible for transmission management in BSS is the Base Station Controller (BSC).
Transmission management functionalities make it possible for the operators to manage the transmission equipment remotely from the BSC or from Nokia
NetAct integrated network management system, which simplifies network maintenance and operation. Supervision functions help minimise the time spent in maintenance, and statistics collection helps the operators analyse and optimise
the use of their transmission equipment. Moreover, new software can be downloaded in a way that does not interfere with the traffic.
Hardware and software requirements BSS transmission network elements
BSS transmission management functionalities Transmission parameters Transmission alarms
Transmission measurements
2.Hardware and software requirements
There are no specific hardware or software requirements for the transmission management functionalities. However, the type of the BTS poses certain
limitations.
The BTS type specific functionalities are listed in the table below.
More details about the functionalities can be found in BSS transmission management functionalities .
Polling list sending with priority is a functionality used in positioning. To ensure accurate positioning calculations, the LMU unit must supply Radio Interface Timing System (RIT) information to the network faster than the normal Q1 polling is able to do. Faster LMU polling is achieved by defining a Q1 polling
priority for each Q1 device, with the LMU having the highest priority. For more information see Location Services .
3.BSS transmission network elements
The base Station Subsystem (BSS) consists of at least one Base Station Controller (BSC) and its Base Transceiver Stations (BTS). The Transcoder Submultiplexer
(TCSM) is also part of the BSS although it is actually located in the MSC site. The three basic configurations (topologies) for transmission between the BSC and
the BTSs are: point-to-point connection
multidrop chain multidrop loop
In point-to-point configuration each BTS is connected directly to the BSC. In the multidrop chain, BTSs form a chain and the first BTS in the network is connected directly to the BSC. In the loop connection, the BTSs form a loop where the first and the last BTS in the loop are connected directly to the BSC via a crossconnecting node. The topology used depends on a number of factors such as the distance between the BSC and the BTS, the number of transceivers (TRXs) used at a particular BTS site and the signalling channel rate between the BSC and the\ BTS. Usually the topology used is a mixture of the three basic topologies. Formore information on the topologies, refer to Nokia BSS Transmission\Configuration .
– There are others : IS95 HDR, EDGE, etc.
» Direct Spread CDMA TDD
» Direct Spread CDMA FDD
» Multi-carrier CDMA FDD
Global 3G comprises of 3 modes :
– Marketed as Global 3G CDMA implying a single unified standard. In reality,
– Mostly dominated by Direct Sequence CDMA.
– Market is expected to be fragmented amongst several competing
IMT2000 guidelines defined by the ITU.
– Analog was 1G. GSM/IS95 were 2G. Next is 3G.
What is 3G ?
standards.
across the world.
Envisioned as a single Global standard allowing seamless roaming
Used interchangeably with IMT2000 although there are some specific
A loosely defined term referring to next generation wireless systems.
4
encompasses three optional modes of operation.”
Telecommunications Union (ITU) of a single CDMA third generation standard that
“Qualcomm and Ericsson ... jointly support approval by the International
Jun 1999 found compromise at the OHG.
“Qualcomm … is not prepared to grant licences according to the … ETSI IPR Policy.”
fair, reasonable and non-discriminatory basis in accordance with the ... ETSI IPR Policy.”
“Ericsson … is prepared to grant licences to these [W-CDMA & TD-CDMA] patents on
Dec 1998 saw a stand-off in standards.
WCDMA, WTDMA, OFDMA, Global CDMA 1 & 2.
Asia Pacific (ARIB & TTA):
WCDMA N/A, UWC-136, cdma2000, WIMS WCDMA, WP-CDMA.
North America(T1P1, TR45.3, TR45.5, TR46.1):
WCDMA, WTDMA,TDMA/CDMA, OFDMA, ODMA.
Europe (ETSI):
In
n
scrambling achieve?
scrambling achieve?
6
Secure link: a linear sequence of length 2
doesn’t
Benefits of wideband signals: multipath provides temporal diversity instead of ISI.
Spectral re-use factor of 1: all cells can use the same frequency spectrum.
does
What
What
Low cross-correlation (at any time offset).
High auto-correlation (at any time offset).
What are their important properties?
in to a low amplitude, wide bandwidth signal.
Converts a high amplitude, narrow bandwidth signal
How do they work?
Pseudo-random sequences: Gold codes, Kasami codes (M-sequences).
‘W’ of WCDMA.
W
Cdma2000 network problem analysis with mobile station 20030212-a-v1.0Tempus Telcosys
Keyword: CDMA, forward coverage, reverse coverage and connection
Abstract: This document describes how to use a Mobile Station (MS) to locate network problems. That is, judge the forward/reverse coverage by viewing the indices displayed on the Debug screen of MS. Then locate the network problems according to reverse Frame Error Rate (FER) and Received Signal Strength Indicator (RSSI) test on the background. This document uses H100 MS as an example for the description. For settings of other CDMA MSs, see the relevant document.
1.1
Displaying Debug Screen of H100 MS
1.2
1) 2) 3) 4)
Switch on the MS; Input password: ##27732726; Press the red Power-off key; Select 3.
The Debug screen is displayed.
Index Value on Debug Screen
Assume that the following information is displayed on the Debug screen:
P232 R085 C0210
03612-00001-1
PAGE Ec: -5.0
RX: -75 TX: NoTx
P232: PN of primary service sector
C0210: System operating frequency
03612: SID
00001: NID
PAGE: Channel mode
Ec: Ec/Io
Rx: Receive level of MS
TX: Transmit level of MS
Thou
It is required that after the course study
you should:
Have a general concept about DT
Master Panorama DT operation
Master Panorama data analysis
Chapter 1 DT Introduction
Chapter 2 Panorama DT Introduction
Chapter 3 Panorama DT Data Analysis
Collect System Air interface data
Analyze Air interface data
Assist Export Analysis report
Qualcom CAIT
CDMA Air Interface Tester
WILL TECH DM2K/Pecker
Pecker Navigator, Pecker Analyzer
Panorama
Qualcom CAIT
CDMA Air Interface Tester
WILL TECH DM2K/Pecker
Pecker Navigator, Pecker Analyzer
Panorama
QCTest™ CDMA Air Interface Tester (CAIT™) 3.1 User’s GuideTempus Telcosys
QUALCOMM Proprietary
Export of this technology or software is regulated by the U.S. Government. Diversion contrary to Ulaw prohibited.
All data and information contained in or disclosed by this document are confidential and proprietinformation of QUALCOMM Incorporated, and all rights therein are expressly reserved. By acceptthis material, the recipient agrees that this material and the information contained therein are heldconfidence and in trust and will not be used, copied, reproduced in whole or in part, nor its contentsrevealed in any manner to others without the express written permission of QUALCOMM Incorporated.
Mobile communications is one of the communications fields that develop rapidly and energetically. The antenna builds the bridge between user terminals and base control devices. It is widely used in the mobile communications and the wireless access communication system. The rapid development of the antenna greatly promotes its technology innovation.
It is important to deeply grasp the knowledge of the antenna, which is useful to:
Install and maintain products.
Promote the network planning.
Chapter 1 Working Principle
Chapter 2 Classification
Chapter 3 Electrical Index
Chapter 4 Mechanical Index
When the conducting cable carries the alternating current, the electromagnetic wave radiation can be formed.
If two conducting cables are close, the directions of their current are opposite, and the electromotive force is counteracted. Thus the radiation becomes week.
If two conducting cables are open, the directions of their current are the same. Thus the radiation becomes strong.
When the length of the conducting cable is like the wavelength, the current on the cable will be enhanced. Thus the radiation becomes strong.
The straight conducting cable which can generate the strong radiation is called the dipole.
The pole whose two arms are of the same length (1/4 Wavelength) is called as dipole or half-wave-length dipole.
C cf radio propagation theory and propagation modelsTempus Telcosys
The radio propagation theory is an important lesson in the radio communication curriculum. This lesson answers the following questions:
How are radio waves transmitted from one antenna to the other antenna?
What features does the radio wave have during the propagation? Which factors affect the propagation distance?
What fruits are achieved by predecessors in the radio wave propagation theory? How to apply the theory to practice?
Chapter 1 Radio Propagation Theory
Chapter 2 Radio Propagation Environment
Chapter 3 Radio Propagation Models
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
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Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
Safalta Digital marketing institute in Noida, provide complete applications that encompass a huge range of virtual advertising and marketing additives, which includes search engine optimization, virtual communication advertising, pay-per-click on marketing, content material advertising, internet analytics, and greater. These university courses are designed for students who possess a comprehensive understanding of virtual marketing strategies and attributes.Safalta Digital Marketing Institute in Noida is a first choice for young individuals or students who are looking to start their careers in the field of digital advertising. The institute gives specialized courses designed and certification.
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Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
2. Possible media for communication
Introduction to Communication Media
Introduction to Microwave communication
Manufacturers of Microwave
Why Microwave?
Characteristics of microwave
Types of Microwave communication
Types of Microwave Links
Requirements for the microwave communication
What is LOS?
Wave Propagation in the atmosphere
Multi path Propagation
LOS Purpose & requirements
Limitations of Line of Sight Systems
Design of Line of Sight Microwave Links
K- factor
Variations of the ray curvature as a function of k Monday, June 03, 2013www.tempustelcosys.com
3. Monday, June 03, 2013www.tempustelcosys.com
Obstacles & Loses
Knife Edge Obstacles
Smooth Spherical Earth Obstacles
Path Loss
Other losses
Why vertical polarization favorable at high freq
Antenna type & Gain
RECEIVER SENSITIVITY, FADE MARGIN AND SIGNAL TO NOISE RATIO
Fading Margin
Reliability
4. Monday, June 03, 2013www.tempustelcosys.com
Copper media
Microwave media
Optical fiber Media
Satellite Media
5. Microwave communication system is used to transfer data from one node to the other node using
the frequency ranging from 2GHz to 60GHz.
Small capacity systems generally employ the frequencies less than 3 GHz while medium and
large capacity systems utilize frequencies ranging from 3 to 15 GHz. Frequencies > 15 GHz are
essentially used for short-haul transmission.
Monday, June 03, 2013www.tempustelcosys.com
6. Few well known Radio Manufacturers
Nokia
Nera
NEC
Siemens
Digital Microwave Corporation
Fujitsu
Ericsson
Alcatel
Hariss
Monday, June 03, 2013www.tempustelcosys.com
7. Monday, June 03, 2013www.tempustelcosys.com
Fast Deployment
Flexibility
Low implementation Cost
Link across Mountains and Rivers are economical & feasible
Quick maintenance of the system
GHz band has very low noise
LOW MTTR
Drawback of Microwave
Needs frequency license
Environment dependant link quality (e.g. rainfall)
LOS not always available
8. Microwave are used for point to point and point to multipoint communication
Microwaves are the electromagnetic waves comprises of electrical and magnetic field at
angle of 90 degree to each other.
Normally communication on microwave is done between 3GHz to 30 GHz frequency
Monday, June 03, 2013www.tempustelcosys.com
9. Monday, June 03, 2013www.tempustelcosys.com
Point to point communication
Point to multi point
communication
10. Long Haul Radios: ~ 30 - 80 km
2 GHz, 7 GHz
Medium Haul Radios: ~ 25 - 45 km
10 GHz, 13 GHz, 15 GHz
Short Haul Radios: ~ 5 - 30 km
18 GHz, 23 GHz, 26 GHz, 38 GHz,
Nokia Metro hopper: < 1 km
57 GHz
(uses oxygen absorption in air to limit range)
Monday, June 03, 2013www.tempustelcosys.com
11. Microwave communication requires a clear line of sight between two nodes
A Fresnel ellipsoids and their clearance criteria concept is used to calculate the radio Line
of sight
Antenna height Calculation for clear LOS
Parameters design like Power ,Frequency , Rx level and many more
Monday, June 03, 2013www.tempustelcosys.com
12. Radio signals, like all electromagnetic radiation, usually travel in straight lines. However, at low
frequencies (below approximately 2 MHz or so) diffraction effects cause significant ray bending,
allowing ray bundles to partially follow the Earth's curvature, thus enabling AM radio signals in low-
noise environments to be recieved well after the transmitting antenna has dropped below the
horizon. Additionally, frequencies between approximately 1 and 30 MHz, can be reflected by the
ionosphere, thus giving radio transmissions in this range a potentially global reach (see shortwave
radio).
However, at higher frequencies, neither of these effects apply, and so any obstruction between the
transmitting and receiving antenna will block the signal, just like the light that the eye senses.
Therefore, as the ability to visually sight a transmitting antenna (with regards to the limitations of the
eye's resolution) roughly corresponds with the ability to receive a signal from it, the propagation
characteristic of high-frequency radio is called "line-of-sight" as per radiowave propagation is called
as "radio horizon".
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14. When rays reaches to the receiver from different paths then two possibilities are there
A) If they reaches in the same phase then the signal strength increases.
B) If they reaches in opposite phase then its cause fading called multipath fading
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15. 1. Purpose
For the establishment of short / long haul LOS links
Feasibility studies
Submission of tenders
Up gradation of existing links
2. Requirements of LOS links
• site locations
• planned antenna height
• direction to the other end of link
• restrictions to cherry-picker, etc.
Output
• LOS/NLOS
• minimum antenna height
• exact antenna location (rooftop)
• panorama picture with
landmarks and their directions
• extra observations
(forests,building sites etc.)
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16. How far we can go: The range of LOS microwave systems is limited by:-
Curvature of earth-Actual
Technical radio characteristics (K-factor)-Modified Earth Curvature
Actual Obstructions en-route in each hop
RF effect of fresnel zone
Path loss
Transmitter power
Antenna gains
Transmission line looses
Frequency of operation
Received power
Receiver threshold
Signal to noise ratio
Fade margin required
Desired reliability of link
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17. Link Design: The design of microwave links, involves three sets of calculations.
1. Working out antenna heights for the link.
K-factor is major dominant variable.
Earth bulge.
Fresnel zone radius.
Actual obstructions on the route
Path Loss
Operating frequency.
Path profile: it indicates the distance from one of the transmitter site where obstructions to the line
of sight radio link may occur.
The object of this calculation is to arrange tower heights along the entire route of the link, so that
an obstruction in the path does not enter into the fresnel zone by a specified amount for a
specified K-factor used.
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18. Earth bulge and K-factor:
The propagation of radio beam is affected by atmospheric conditions and the obstructions on the way. It
can be subjected to:
Diffraction
Reflection
Refraction
Most important is refraction, which is caused by changes in the density of atmospheric layers
confronted by the radio beam front.
The curvature of earth and slight bending of waves as it is refracted downwards by the earth’s atmosphere
are two factors, that, must be considered while making path profiles.
The earth’s curvature and microwave beam refraction are combined to form fictitious earth curvature or
earth bulge.
EARTH CURVATURE (M) = 0.078 x d1 x d2 / K
WHERE K = EFFECTIVE EARTH RADIUS/TRUE EARTH RADIUS
EARTH BULGE = d1 x d2 / 12.75 x K
EARTH BULGE FOR K=4/3 = d1 x d2 / 17
EARTH BULGE FOR K=2/3 = d1 x d2 / 8.5
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19. Different K values
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True Earth’s curvature
= 6,371 Km
K=1
K=0.5
K=0.33
20. Fresnel zone:
The radio beam energy travels in an ellipsoidal wave front, the different components of which
maintains different path lengths.
The distance from microwave beam’s center is commonly measured in fresnel zones to take into
account both frequency and distance.
The first fresnel zone (FFZ) is the surface of the point along which the distance to the ends of the
path is exactly ½ wave length larger than the direct end to end path.
FFZ radius in meters=17.32√d1*d2/fD
Where d1 & d2 are in km’s, f is the frequency in GHz and D is the hop distance in Km’s.
In order to achieve a free space propagation condition for a radio beam at least 60 % of FFZ
should be cleared under the standard atmospheric condition of K=4/3.
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21. Keep 1st Fresnel zone clear of obstacles
nth Fresnel zone: Ellipse around direct path, where path difference to direct line is n* /2.
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d
b
1st Fresnel zone
2nd
3rd
Radius for n-th zone = b * sqrt(n)
b
d km
f MHz
m274
[ ]
[ ]
[ ]
22. 1. If f=2.5 GHz and D=30 Km, then FFZ=32.99 M
2. If f=4.5 GHz and D=30 Km, then FFZ=24.03 M
3. If f=6.5 GHz and D=30 Km, then FFZ=19.75 M
Conclusion :FFZ radius decreases with increase in frequency.
1. If f=2.5 GHz and D=30 Km, then FFZ=32.99 M
2. If f=2.5 GHz and D=34 Km, then FFZ=35.33 M
3. If f=2.5 GHz and D=36 Km, then FFZ=36.46 M
Conclusion: FFZ radius increases with increase in distance
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23. With 100% fresenal zone
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NATURAL EARTH FEATURES
EARTH BULGE
“A” “B”
T
BUILDING
d1 d2
D
f
24. Types of Loss
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Obstacle loss
Knife edge
obstacle loss
Smooth spherical
earth obstacle loss
30. Free Space Loss
Free space loss: consider a signal is traveling between transmitter at “A” to a receiver at “B”.
There is for a given frequency and distance, a characteristic loss. This loss increases with
both distance and frequency. It is known as free space loss.
Free space loss LdB=92.44+20 log10 F+20 log10 D
Where F is in GHz and D is in km's.
If D is 40 Km and F is 6 GHz, then free space in dB
LdB=92.44+20 log 40+20 log 6
=92.44+20*1.6021+20*0.7782
=92.44+32.042+15.564=140.046 dB
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31. Example:- Free space loss if F=2.5 GHz and D=30 Km
FSL (dB) = 92.44 + 20 log 2.5 + 20 log 30
=92.44 + 20*0.398 + 20*1.478
=92.44 + 7.96 + 29.56 = 129.96 dB
Now, if F=7.5 GHz (changed) and D=30 Km (unchanged)
FSL (dB) = 92.44 + 20 log 7.5 + 20 log 30
=92.44 + 20*0.875 + 20*1.478
=92.44 + 17.5 + 29.56 = 139.5 dB
Now, if F=2.5 GHz (unchanged) and D=40 Km (changed)
FSL (dB) = 92.44 + 20 log 2.5 + 20 log 40
=92.44 + 20*0.398 + 20*1.602
=92.44 + 7.96 + 32.04 = 132.44 dB
It can be seen, that, free space loss increases both with distance and frequency
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32. Precipitation
Transmission of microwave signal above 10 GHz is vulnerable to precipitation The energy
is attenuated due to radiation (scattering) and absorption (heating) Scattering
Radio waves are a time varying electromagnetic field, the incident field will
induce a dipole moment in the raindrop. The rain drop will also have the same time Variation
as the radio waves and will act as an antenna and reradiate the energy. As rain drop-antenna
have low directivity it will radiate energy arbitrary direction and add to loss.
Absorption
When the wavelength becomes small (High freq. < 18GHz) relative to the raindrop size more
energy is absorbed by heating of the raindrop.
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33. As the rain-drop increases in size they depart spherical shape and extended in the
the horizontal direction.For freq. Higher than 18 GHz the wavelength is generally
in mm. So these rain-drops attenuate horizontally polarized waves than the vertical
Polarized.
Raindrop shapes
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1mm 1.5mm 2mm 2.5mm
34. Transmit power : Transmit power is the power in dB that is required for the signal to travel from
one node to other.
The max and minimum transmission power for the equipment is vendor specific and changes
with the capacity of the E1 carried by the radio.
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35. Digital Modem : To interface with customer equipment and to convert customer traffic to a
modulated signal
RF Unit : To Up and Down Convert signal in RF Range
Passive Parabolic Antenna : For Transmitting and Receiving RF Signal
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36. Antenna type : There are different types of antenna used for the Microwave communication.
Mostly parabolic antennas are used.
Antenna can be put in vertical or horizontal mode. Also cross polarized antennas are available
that can carry both horizontal and vertical beams with a very low interference.
Gain of Antenna: Gain of the antenna is calculated by the approximate formula
Gain = 17.8 + 20 log (D.f) dBi
Where
D = Antenna diameter [m]
F = Frequency in GHz
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37. Receiver Sensitivity: Sensitivity or Threshold Power of receiver is the level of signal which would
produce a 30 dB signal to noise ratio out of the base band of an analogue receiver, or a bit error
ratio (BER)=10-4 out of the base band of a digital receiver. Typically it is -70 to -90 dB.
Fading: Received Signal vary with time due to multipath fading and rain etc. Refractive index of
atmosphere varies with Temp. humidity and pressure which in turn cause the electromagnetic
waves to change direction. Another cause for Multipath fading is ground reflection. So a fade
margin is built in Link Designing.
Fade Margin: The fade margin is the power level, that, the unfaded received signal can fall to
until it reaches the receiver threshold. This margin will vary depending on geographic and climatic
conditions of different geographic areas and desired reliability of the system. Typically it is 20-40
dB.
Fade Margin dB=Prx-Pthresh
Signal to Noise Ratio: It’s the minimum power difference between the wanted received signal
and received noise.
Signal/Noise Ratio (dB)=10 log10 (Signal Power/Noise Power)
Typically it is > 50 dB, logically it should be more than the Fade Margin, so that it is
always below the threshold level.
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38. Fading margin:
“Safety” margin. Should be
large enough to guarantee
that quality and availability
objectives are met during
fading conditions.
Typical value ~ 40 dB
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Received Power
Fading Margin
Receiver
threshold
39. Reliability of the link: Outage time for each hop and for the complete link is to be worked out,
which in turn will give the over all reliability of the link in terms of percentage.
Single hop reliability (%) Fade Margin
99.9 28 dB
99.99 38 dB
99.999 48 dB
CCIR defines its availability objective for radio relay systems over a hypothetical
reference circuit as 99.7 %. Resulting unavailability 0.3 % is of three components.
Outage due to power failure
Outage due to equipment failure
Outage due to propagation
It is reasonable to allot 50 % of the outage time to power and equipment failures and 50
% for propagation. Considering propagation alone, system should have an availability (reliability)
of 99.85 % apportioned across the 2500 Km route. This provide guide to establish a per hop
propagation reliability for a particular system.
Planner rather first set the limit for the reliability and for wide band links it is better than
99.99 %.
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