Installation Manual

IBRInstallationGuide
 Page25of40 Doc#770‐00001‐13
 Sept.21,2014
 IBR102#showinterfacesradio0status
Ifalinkisnotautomaticallyestablishedwithintenminutes,thenconsiderthefollowingtroubleshooting
suggestions:
 ChecktoensurethatthepartnerIBRonthelinkisoperational.
 ChangethedirectioninwhichtheIBRispointed.
 ChangetheIBR’selevation.
 Determineifthelinkistoolongfortheenvironment.
6.9 Pointing&LinkOptimization
IBR’stransmitandreceiveantennaseachhaveaonehundredandtwentydegree,3dBbeamwidthcentered
ontheridgeatthetopoftheradome.Therefore,aligningorpointinganIBR,asdiscussedbelow,means
orientingIBRsothattheridgeontheradomeisfacingthedesireddirection.
6.9.1 Line‐of‐SightandNearLine‐of‐SightLinks.
HorizontalAlignment‐OrienteachIBRsothatitsradomeispointedtowardtheotherendofthelink.
BecauseIBRhasarelativelywide(120‐degree)3‐dBbeamwidth,afewdegreesofmisalignmentisnotlikely
tohaveaneffectonlinkperformance.
VerticalAlignment–BecauseIBRhasonlyafifteendegree3‐dBbeamwidthintheverticaldirection,greater
careshouldbetakeninsettingtheelevationanglesothateachIBRispointingasnearlyaspossibletoward
theotherendofthelink.
6.9.2 Non‐Line‐of‐SightLinks.
HorizontalAlignment–Theprocessforfindingtheoptimumpositionforeachendofthelinkdependson
whetheritispossibletoestablishalinkbyaimingtheIBRsateachother,andifthereisthepossibilityof
reflectionfromabuilding.ThefollowingisasuggestedproceduretouseiftheIBRsdonotsynchronizeafter
beingaimedtowardseachotheranditispossibletobenefitfromreflectionoffabuilding:
 StartwitheachIBRinabest‐guessorientationtowardtheotherendofthelink.
‐ KeepingthenearIBR’spositionfixed,rotatethedistantIBRhundredandtwentydegreesinazimuth.,
andallowoneminuteforthelinktosynchronize.
‐ RotatethedistantIBRanotheronehundredandtwentydegrees,andallowanotherminuteforthe
linktosynchronize.
‐ Repeattheprocessathirdtime.
 RotatethedistantIBRanotheronehundredandtwentydegrees.Atthispoint,itwillbeinitsoriginal
position.
 RotatethenearIBRonehundredandtwentydegrees.Nowrepeatthestepsin(a)above,rotatingthe
distantIBRthroughthreehundredandsixtydegreesinonehundredandtwentydegreeincrements.
Whenusingstepsofonehundredandtwentydegreesasindicatedabove,therewillbeatotalofninepossible
combinationsofpositionsforthetwoIBRs.Iftheradiosarerotatedonlyninetydegreeseachstep,therewill
beatotalofsixteencombinations,however,theresultingalignmentmightbemoreoptimal.
InasituationwheretheIBRssynchronizewhenpointedtowardeachother,anditisnotpossibletogeta
reflectionoffabuilding,amoreempiricalapproachmightproduceafasterresult.Whenalinkhasbeen
established,rotateoneIBRninetydegrees.IftheSNRimproves,rotateitanotherninetydegrees,and
continueinthiswayuntilSNRbeginstofall,thenmovebacktothepreviousposition.IfSNRdoesnot
improve,returntheIBRtoitsoriginalposition.Repeatattheotherendofthelink.
Ifalinkcannotbeestablished,tryallsixteenaimingcombinations,spendingoneminuteateachcombination
togivethelinktimetosynchronize.Dothisbylockingthenearendat0degreesazimuth,andthenaiming
thefarendofthelinkat0,90,180,and360degrees,spendingsixtysecondsateachposition.Next,movethe
nearendto90degreesandrepeatat0,90,180,and360degreesatthefarend.Continueuntilalinkhasbeen
establishedorallsixteencombinationshavebeentried.