Radwin 2000 - Page 491

RADWIN2000UserManual Release2.8.30 F‐2
SingleAntennasatBothSites
UponselectingAntennaTypeasDual,RADWIN2000automaticallyselectsthismodeand
doublestheairrates.
RADWINManagerindicatesacaseofunbalancedRSSbetweenthetwoantennas.
DiversityMode
DiversityModeusestwoantennastoimprovethequalityandreliabilityofthelink.Often,
thereisnotaclearline‐of‐sight(LOS)betweentransmitterandreceiver.Insteadthesignalis
reflectedalongmultiplepathsbeforefinallybeingreceived.
Eachsuch“bounce”canintroducephaseshifts,timedelays,attenuations,andeven
distortionsthatcandestructivelyinterferewithoneanotherattheapertureofthereceiving
antenna.Antennadiversityisespeciallyeff ectiveatmitigatingthesemulti‐pathsituations.
Thisisbecausemultipleantennasaffordareceiverseveralrecordingsofthesamesignal.Each
antennawillbeexposedtoadifferentinterferenceenvironment.Thus,ifoneantennais
undergoingadeepfade,itislikelythatanotherhasasufficientsignal.Collectivelysucha
systemcanprovidearobustlink.
Ante nnadiversityrequiresantennaseparationwhichispossiblebyusingadual‐polarization
antennaorbytwospatiallyseparatedantenna s.
UseDiversityinsteadofMIMOinthefollowingsituations:
• WhenthesystemcannotoperateinMIMOMode
• Whenoneofthereceivershashighinterferencecomparedtothesecondreceiver(i.e.
thesystemis“unbalanced”)
• WhenyouachievehighercapacityinDiversityModethaninMIMOMode
• WhenhighrobustnessisofimportanceandthecapacityofDiversityModeissufficient
(upto25Mbpsfullduplex)
SingleAntennasatBothSites
Byselectingasingleantennaatbothsites,theODUsoperatewithasingleradiothatis
connectedtotheANT1connector.Thesecondradioisautomaticallyshutdown.
SingleatOneSite,DualAntennasattheOther
InthismodeoneofthesitesusestheODU withasingleantennawhiletheothersiteusesthe
ODUwithadualantenna.
Theadvantagesinthismodeincomparisontousingasingleantennainbothsitesare
doubledtotalTxPowerandadditionalpolarizationand/orspacediversity(dependingonthe
polarizationofinstalledantennas).
Theairratesusedinthismodearesameaswhenusingsingleantennasinbothsites.