Installation guide

Determining the Antenna Locations
RoamAbout Antenna Site Preparation and Installation Guide 1-5
Line of Sight
Theshapeoftheradiobeam,definedastheFresnelZone,iswidestinthemiddle.TheFresnel
ZoneisshownasthegrayareabetweentheantennasinFigure 1‐1.Theexactshapeandwidthof
theFresnelZoneisdeterminedbythedistancebetweentheantennaandfrequency
oftheradio
signal.
Theradiusoftheradiobeam,shownasthelowerhalfoftheFresnelZone,isthedistancefromthe
centerofthebeamoutwardinanydirection.Thelengthoftheradiusisnotbasedonthedatarate
andthetypeofantenna.
Figure 1-1 Fresnel Zone and Line of Sight Clearance
Ifa
significantpartoftheFresnelZoneisobstructed,aportionofradioenergyislost,resultingin
reducedperformance.Foroptimalperformance,ensurethattheantennaproductsyouchoose,in
combinationwiththeheightoftheantennainstallationaboveground,providesufficientclearance
toallowyourantennainstallationtocover
thedistancebetweenthetwosites.
Obstacleswithinthelineofsightcansignificantlyreducethedistanceandperformance.
Obstructionsincludeneighboringbuildings,trees,andpowerlines,asshowninFigure 1‐2.
Total Distance
Radius