User's Manual Part 1

Estimating RF Coverage
InterReach Fusion Wideband Installation, Operation, and Reference Manual Page 87
D-620616-0-20 Rev H • TECP-77-044 Issue 7 • May 2013 © 2013 TE Connectivity Ltd.
ExampleDesignEstimateforan1900MHzCDMAApplication
1 Designgoals:
• PCS
(1920MHz=averageofthelowestuplinkandthehighestdownlinkfrequencyin
1900MHzPCSband)
• CDMApro
vider
• 8
CDMAcarriersinthesystem
• –8
5dBmdesigngoal(to95%ofthebuilding);theminimumreceivedpoweratthe
wirelessdevice
• Basestationwit
hsimplexRFconnections.
2 Pow
erPerCarrier:Thetablesin“MaximumOutputPowerperCarrier”onpage65provide
maximumpowerpercarrierinforma
tion.The1900MHzCDMAtableindicatesthatFusion
Widebandcansupporteightcarrierswitharecommendedmaximumpowerpercarrierof6.5
dBm.Theinputpowershouldbesettothedesiredoutputpowerminusthesystemgain.
3 Buildinginformat
ion:
• 16
floorbuildingwith9,290sq.meters(100,000sq.ft.)perfloor;total148,640sq.meters
(1,600,000sq.ft.).
• W
allsaresheetrockconstruction,suspendedceilingtiles.
• Anten
nasusedareomni‐directional,ceilingmounted.
• Standardofficee
nvironment,80%hardwallofficesand20%cubicles.
4 LinkBudg
et:Inthisexample,adesigngoalof–85dBmisused.Suppose3dBi
omni‐directionalantennasareusedinthedesign.Then,themaximumRFpropagationloss
shouldbenomorethan94.5dB(6.5dBm+3dBi+85dBm)over95%oftheareabeing
covered.Itisimportanttonotethatadesigngoalsuchas–85dBmisusuallyderivedtakinginto
accountmultipathfadingandlog‐normalshadowingcharacteristics.Thus,thisdesigngoalwill
onlybemet“onaverage”over95%oftheareabeingcovered.Atanygi
venpoint,afademay
bringthesignallevelunderneaththedesigngoal.
Notethatthismethodofcalculatingalinkbudgetisonlyforth
edownlinkpath.For
informationtocalculatelinkbudgetsforboththedownlinkanduplinkpaths,referto“Link
BudgetAnalysis”onpage89.
Table75.
ApproximateRadiatedDistancefromAntennafor2.5GHzWiMAXApplications
Facility
Distance from Antenna
Meters Feet
Open Environment 59 194
Moderately Open Environment 47 152
Mildly Dense Environment 41 134
Moderately Dense Environment 35 112
Dense Environment 25 83