User's Manual

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Note that BIU does not operate if the "+" terminal and the "–" terminal of the -48V power
are not inserted into the accurate polarity.
When you connect -48V power with BIU, use the ON/OFF switch of MPSU located at the front
of BIU to check the power.
5.1.3 RF Interface at BIU
BIU can be connected with Bi-Directional Amplifier and Base Station Tranceiver.
To connect BIU with BDA, you need to use a duplexer or a circulator to separate TX/RX signals
from each other.
BIU can feed external TX/RX signals from the Back Plane.
Using MDBU separated from each carrier band, BIU can easily expand and interface with bands.
As seen in the table below, MDBU is divided into Single and Dual Bands. The unit can be
connected with two to four carrier signals per band. At the rear, #1~4 marks are seen in order
per MDBU. The following table shows signals to be fed to corresponding ports:
No Unit naming Description In/out RF Port
Power Switch LED Description
Abnormal, Not supply Power -48Vdc
ON
Normal supply power -48Vdc
Normal Status
O
DC ALM
Failure of output Power
ON
I
DC ALM
Normal Status