Installation Guide

TVWhiteSpaceInstallationGuide Release1.0 B‐1
AppendixB:AboutAntennas
B.1ScopeofthisAppendix
Thisappendixprovidessomebasicinformationandconsiderationsregardingantennasand
whatyouneedtotakeintoaccountwhenconfiguringantennaparameters.
B.1AntennaIssues
ThechoiceofTxPower,antennagainandcableloss(betweentheradioandtheantenna)
determinestheEIRPandisaffectedbysuchconsiderationsasradiolimitationsandregulatory
restrictions.
Beforeproceedingtoantennainstallationdetails,thefollowingbackgroundinformation
shouldbeconsidered:
B.2AboutSingleandDualAntennas
EachRADWINradioisactuallymadeoftworadiotransceivers(radios).Theradiosmakeuse
ofalgorithmsthatutilizebothSpatialMultiplexing(alsocalledMIMO)andDiver sityresulting
inenhancedcapacity,rangeandlinkavailability.Thenumberofantennas(i.e.radios)usedis
determinedbyuserconfigurationandbyautomaticsystemdecisions,explainedbelow.
B.2.1DualAntennasattheHBSandanSU
Whenusingdualantennasatbothsites(singlebipolarantennaortwomo‐unipolarantennas)
youcanchoosebetweenSpatialMultiplexingModeandDiversityMode.
SpatialMultiplexingMode
Underthismode,thesystemdoublesthelinkcapacity.Atthesametime,itkeepsthesame
rateandmodulationperradioaswasusedwithsingleantenna,thusincreasingcapacity,
rangeandavailability.
FOR REGULATORY USES ONLY