Date post: | 21-Nov-2014 |
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NETWORKS RF SURVEY TX SURVEY DRIVE TEST SURVEY
ABSTRACT:f IN THIS PROJECT I INTEND TO DESCRIBE VARIOUS SITE
SURVEYS IT CONTAINS DETAIL ANALYSIS OF:f GSM ARCHITECTURE f CHANNELS (USED IN DRIVE TEST) f TX AND RF SURVEY f VARIOUS TOOLS f MICROWAVE AND GSM ANTENNA(FREQUENCY) f FUTURE ASPECTS
HOW MUCH IS ACHIEVED AND HOW MUCH TIME IT WILL TAKE TO COMPLETE
f BASICS OF TELECOMS f TX SURVEY IS COMPLETED f HALF OF RF SURVEY IS DONE f DRIVE TEST:YET TO START
INTRODUCTIONWhat is GSM ? f Global System for Mobile (GSM) is a second generation cellular standard developed to cater voice services and data delivery using digital modulation It is organised in three subsystems:f Base Station Subsystem (BSS) f Network Switching Subsystem (NSS) f Network Management Subsystem (NMS)
GSM SYSTEM ARCHITECTURE
GSM SPECIFICATIONf GSM TYPES: GSM900 AND GSM1800 f Carrier Separation
: 200 Khz f Duplex Distance : 45 Mhz f No. of RF carriers : 124 f Access Method : TDMA/FDMA f Modulation Method : GMSK f Modulation data rate : 270.833 Kbps
LOGICAL CHANNELS
TX SURVEYf is carried out to avoid obstacle for microwave transmission f To decide site details to accommodate all transmission network planning requirement.
RF SURVEYf To identify the best possible locations to install sites f To ensure 100% wireless coverage, along with maximum performance, within
the desired area.
TRANSMISSION SURVEY REPORT PROVIDESf site address with GPS coordinate f map and site situation f existing transmission equipment data f type of transmission, frequencies, configuration and capacity f Line of sight and Path loss calculation f placement of transmission equipment f site readiness including: space for equipments, estimation time
for implementation, tower, power resources f photos of site situation, equipment placement, panoramic 360 degree
TOOLS USEDf GPS f COMPASS f CAMERA f BINOCULAR f MAPINFO PROFESSIONAL f RL TOOL OR GLOBAL
GPS AND COMPASSTower Center
RTK
Distance GPS 1 78.081194/30.412444 AMSL:1296m GPS 2
CAMERAf12 PANAROMIC PHOTOS fAT 30 DEGREE IN 12 DIRECTIONS fProposed antenna locations. fThe camera sees what the antenna will see,
and in this way LOS path conditions are established.
MAPINFO PROFESSIONALTELECOM DATA AND MAPINFO TOGETHER BE USED FOR SITE SELECTION
RL TOOL
FRESNEL ZONEf The area around the visual line-of-sight that radio waves spread
out into after they leave the antenna. This area must be clear or else signal strength will weaken.
GENERAL EQN
where, f Fn = The nth Fresnel Zone radius in metres f d1 = The distance of P from one end in metres f d2 = The distance of P from the other end in metres f = The wavelength of the transmitted signal in metres
HOW FRESNEL ZONE CAN BE DISRUPTED
MICROWAVE ANTENNAf15 GHZ f7 GHZFROM 0 TO 10KM ABOVE 10KM
GSM ANTENNA GSM900f GSM 900:USED IN RURAL OR LESS DENSER AREAS f RF Spectrum
GSM 900 Mobile to BTS (uplink): 890-915 Mhz BTS to Mobile(downlink):935-960 Mhz Bandwidth : 2* 25 Mhz
GSM1800
GSM 1800:USED IN URBAN OR HIGH DENSER AREAS GSM 1800 Mobile to BTS (uplink): 1710-1785 Mhz BTS to Mobile(downlink) 1805-1880 Mhz Bandwidth : 2* 75 Mhz
FUTURE ASPECTSf NEED OF APPROX 2 LAKH SURVEY ENGINEERS f 18 NEW TELECOM OPERATORS AND 12 ALLREADY EXIST f UPCOMING 3G OR UMTS TECHNOLOGY NEEDS MORE
SITES
THANK YOU