Thursday, December 27, 2012

RF Engineers & Resposibilities

  On completion of the module one should be clear about the RF parameters details of Drive test required during drive test what does it mean and how much it is important.§  RF Drive Test§  RF Survey & Planning§  RF Optimization§  RF Report Preparation§  RF Data Analysis 




The term "RF waves" typically refers to radio frequency waves, a form of electromagnetic energy invisible to the human eye. Radio frequency communication is virtually omnipresent in the modern world, used for everything from automobile radios to computers.


RF Survey Engineer

RF Transmission/LOS Engineer:§Responsible for Site survey of RF, and Microwave Line of Sight (LOS) Survey's, taking panoramic pictures and potential obstacle to LOS and conduct table study of each site. 


BTS & I& C  ENGINEER 
Environment BTS Installation and Commissioning Supervision of the installation of sites including GSM antennas, feeders, MW links, TMA , Tower Earth and Lightening, Shelters and all indoor equipments.


IBS Testing Engineer:

Altimeter is an instrument used to measure the altitude of an object above a fixed level.  

Important points to be checked during RF Survey:    
Radio frequency (RF) is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals.
 RF waves travel at the speed of light, and are also emitted by natural sources including stars.§Radio frequency (RF) energy has been used in medical treatments for over 75 years, generally for minimally invasive surgeries, using radiofrequency ablation and cryoablation, including the treatment of sleep apnea§ Magnetic resonance imaging (MRI) uses radio frequency waves to generate images of the human body
 RF engineers are specialists in their respective field and can take on many different roles, such as design, installation, and maintenance.§RF engineers require many years of extensive experience in the area of study.§This type of engineer has experience with transmission systems, device design, and placement of antennas for optimum performance
  An RF Engineer at a broadcast facility is responsible for maintenance of the stations high-power broadcast transmitters, and associated systems§ RF design engineer must be able to understand electronic hardware design, circuit board material, antenna radiation, and the effect of interfering frequencies that prevent optimum performance within the piece of equipment being developed
SCOPE IN RF INDUSTRY:
   Transmission/LOS Survey Engineer
             EMF Survey

             IBS Engineer
   BTS / I&C Engineer
             BSS/O&M Engineer

             Drive Test Enginee

            Switch/NSS Engineer
  RF Survey & DT Co-ordinator 
  RF Planner 
  RF Optimizer
 SURVEY ENGINEER
    Perform technical site survey, site including path profile of the transmission networkand verification of Line-of-Sight (LOS)
             Site survey for backbone, access and remote access microwave links
  Line Of Sight survey for short and medium haul microwave links§Providing antenna height, orientation and azimuth of antennas
   Verify the suitability of Sites from RF and Transmission point of view
   Responsible for RF survey for new sites (Macro site & Repeaters)
   Check Latitude & Longitude
   Done Microwave Surveys for Line of Sight (LOS) Clearance
  Taking care of all material needed and ordered for sites from the warehouse.
  Configuring the Cross connection
  Using Site Master to check the installation of the feeders
  Supervising the installation of the equipment
  Testing all equipment after installation and their functionality before integrating the site. Commissioning for sites by installing BTS
  Power testing for all stations and systems in the network.§Doing the Acceptance work under ALU
Suggest and implement Network Parameters changes for reducing call drops and better coverage and analysis of impact after changing of parameter in the indoor sites
 New Site verification & Optimization of the network, Coverage for the integrated indoor sites§ Conduct RF Technical Site Surveys (TSS) for the In-Building design
Performing RF survey, Antennae Location & Cable Routing
Checking In building installations and make sure that certain standards and quality level is maintained
Once RF equipment is installed, perform RF data collection to ensure that the quality of service meets RF design specifications such as Rx Lev, Rx Qual, Handover, parameter verificationSite Auditing for the indoor sites to Checking coverage for Indoor solution to check the sufficient Rx strength & Rx quality. Checking all values, handovers relating with neighboring cells
BSS/O & M Engineer:
     Standardizing the Network Key Performance Indicators (KPI’s) and reduce Drop calls and Ineffective Attempts
Troubleshoot system problems such as Handover failure, Poor originations, Frequency-related issue and Interference. Identify causes of RF interference, make recommendations and provide solutions for reducing interference
Maintenance and Calibration of BTS equipment at all cell sites e.g. RF transceivers, VSWR tests etcPerformance Statistics and Event Management at OMC-R for system performance Evaluation and analysis RF OPTIMIZATION ENGINEER:
Analyzing daily and weekly basis KPI trend for parameters like Call Setup Success Rate, Drop Call Rate (DCR), Rx Quality & level , Handover Success Rate etc. and resolve problem promptly
Analyzing & rectifying Neighbor discrepancies, non-symmetrical Neighbor, adjacent Co-BISC, Co- CH and Adj-CH neighbors§Responsible for Post processing of drive data and implementing the changes with the help of ACTIX post processing tool
Analysis of daily reports of OMCR and modification of undeclared neighbor list for each Sector to maintain KPIsRF PLANNER
Nominal planning , RF Network Planning, Neighbor planning , Coverage Planning & Frequency Planning, Preparation of Database (LAC, CI,…) , Creating daily KPI report based on Daily Counter.§Taking Status of Survey Site & Co-ordinate with Survey Engineer & Survey Co-ordinator
TELECOM TOWERS:
 Telecommunication towers are used for communication purposes among people 
All the wireless communication, mobile networking, radio broadcasting and television antennas are connected via these towers
 A full telecommunication tower is a whole set of mechanical structures and electronic signal processing unit which is used to connect people via telecommunications
All the telephone lines and mobile phone services are connected through these towers
These towers are also used for radar system and other armed forces purposes
Different heights of towers are used in different places and purposes. They can vary from 15 to 60 meters and some time more if required
For example in the land areas towers are higher in hill area so 15 to 30 meters high towers can be used but in land areas they are 30 to 60 meters in height
There are different types of the telecommunication towers which are used i.e. monopole, self supporting and guyed etc
The most used are the self supporting towers in the field of telecommunication, which is the specialization of final project and thesis as well
Based on structural action.§Towers are classified into three major groups based on the structural action.
They are:               
      Self supporting towers               
              • Guyed towers             
      Monopole Self supporting towers
The towers that are supported on ground or on buildings are called as  self-supporting towers
Though the weight of these towers is more they require less base area and are suitable in many situations
Most of the TV, MW, Power transmission, and flood light towers are self-supporting towers
Guyed towers:
Guyed towers provide height at a much lower material cost than self-supporting towers due to the efficient use of high-strength steel in the guys.
Guyed towers are normally guyed in three directions over an anchor radius of typically 2/3 of the tower height and have a triangular lattice section for the central mast
Tubular masts are also used, especially where icing is very heavy and lattice sections would ice up fully
These towers are much lighter than self- Design of Steel Structures
Whenever large open space is available, guyed towers can be provided
There are other restrictions to mount dish antennae on these towers and require large anchor blocks to hold the ropes
 Monopole:
It is single self-supporting pole, and is generally placed over roofs of high raised buildings, when number of antenna required is less or height of tower required is less than 9mBased on cross section of tower
Towers can be classified, based on their cross section, into square, rectangular, triangular, delta, hexagonal and polygonal towers
 Open steel lattice towers make the most efficient use of material and enable the construction of extremely light-weight and stiff structures by offering less exposed area to wind loads
  Most of the power transmission, telecommunication and broadcasting towers are lattice towers.
 Triangular Lattice Towers:
Triangular Lattice Towers have less weight but offer less stiffness in torsion.  With the increase in number of faces, it is observed that weight of tower increases.
The increase is 10% and 20% for square and hexagonal cross sections respectively.  If the supporting action of adjacent beams is considered, the expenditure incurred for hexagonal towers is somewhat less Based on the type of material sections
Based on the sections used for fabrication, towers are classified into angular and hybrid towers (with tubular and angle bracings).
 Lattice towers are usually made of bolted angles:
Tubular legs and bracing can be economic, especially when the stresses are low enough to allow relatively simple connections.
Towers with tubular members may be less than half the weight of angle towers because of the reduced wind load on circular sections.
However the extra cost of the tube and the more complicated connection details can exceed the saving of steel weight and foundations.
 Based on the placement of tower§Based on this placement, Communication towers are classified as follows:
Green Field Tower Roof Top Tower Erection Erected on natural ground with suitable foundation Erected on existing building with raised columns and tie beams.
Height 30 – 200 m 9 – 30 usual Location Rural Areas Urban Areas Economy Less More

Based on the number of segments: 

The towers are classified based on the number of segments as three slope tower;
Two slope tower;
Single slope tower;
Straight tower
RF SURVEY: 
    RF survey is carried out to find out suitable location for BTS cell site giving best desired result on RF
    RF Survey is done after the RF planning. RF planning data is created based on indoor & outdoor coverage criteria in the circle where mobile services are to be provided
   RF survey is important because it gives visual details to RF planner. Based on these details planner can create better model§ Two types of RF survey is conducted:                

         a) Nominal Survey   b) Hot Spot Survey  
Tools used during the RF survey:   
a) GPS        
 b) Digital Camera       
 c) Magnetic Compass       
 d) Map Info Software       
 e)Measuring Tape   
  f)Binocular     
            g) Altimeter

 Global Positioning System:
  (GPS) is a space-based satellite navigation system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites. 
It is maintained by the United States government and is freely accessible to anyone with a GPS receiverTilt meters and inclinometers measure the angle of inclination of an object        
  A compass is an extremely simple device. A magnetic compass (as opposed to a gyroscopic compass) consists of a small, lightweight magnet balanced on a nearly friction less pivot point. 
The magnet is generally called a needle. One end of the needle is often marked "N," for north, or colored in some way to indicate that it points toward north. On the surface, that's all there is to a compass. 
Type of area-
Residential/commercial      
   b) Type of Population- Income wise     
   c) Any hilly areas or rivers or forest falling & direction       
   d) Type of buildings available     
             e) Check for immediate obstructions  

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