User's Manual

Confidential&Proprietary119/122 SC‐DAS
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ThischapterdescribesadditivefunctionsofSC‐DAS
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7.1 Shutdownfunction(TXoutputshutdown)
The DAS has an automatic shutdown function to protect the DAS itself and the wireless
networkwhenthenormaloperationalconditionscannotbemaintained
Shutdownistriggeredautomaticallywhenthecompositepowerdownlinkoutputisabove
thevaluesdefined as averageforthe devicefora period nottoexceed
5seconds. Critical
levelsaresetthroughtheGUI
After automatic shutdown, the system may automatically turn‐on in order to assess
whether the temporary condition has changed. If the condition is still detected, the DAS
shallshutdownagain.Thisactionwillberepeated5times
AfterThe5
th
time,iftheconditionisstilldetected,theDASwillbeshutdownpermanently.
Thefollowingdiagramshowstheshutdownlogic
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Figure7.1–Shutdownlogicdiagram
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Aftertheretrylogicexhaustsitself,theDASwillshutdownpermanentlyandilluminatethe
faultviavisualfaultindicator
PermanentshutdownsoftheDASwillalsobereportedtotheNOCthroughtheNMS
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7.2 TotalPowerLimitfunction(TXOutputALC)
InordertoprotecttheHPAandnottoradiatespuriousemissions,outputpowersislimited
to a defined value which is set by the operator in advance. To execute this function,
operatorshouldturn‐ontheALCfunctionandsetlimitlevelthroughtheGUI.Iftheoutput
power
 exceeds the defined value, the output attenuator is adjusted to return it within
defined value. The output attenuator’s adjustment range is 25dB max. If output power
decreases, attenuation is decreased using the AGC function to return to the initial
attenuationlevel.
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