User's Manual Part 1

SystemDescription
8
Base Station Interface Unit (BIU)
TheBaseStationInterfaceUnit(BIU)istheinterfacebetweentheoperator’sbasestationandtheFiber‐DASsystem.
TheprimarypurposeoftheBIUistoadjustuplinkanddownlinksignallevels.TheBIUispoweredfromtheMFU
backplaneandcommunicatesviaEthernetwiththeBGW.
Figure 4 BIU Signal Flow
Base
Station
Base Station
Interface
Interconnect
Unit
Fiber-Optic
Interface Units
Fiber-Optic
Cables
to
Remote
Units
(Antenna)
Master Frame Unit
FOI
FOI
FOI
FOI
ICU
BIU
TheBIUhasuplinkanddownlinkRFconnectorsonthefrontpanelandisavailableintwovariants,onecontaining
duplexfiltersoronewithseparateuplink/downlin kpaths,dependingontheneedsfortheconnectiontothebase
station.InmostcasestheduplexedversionwithacombinedDL/ULportsisused.
Inadditiontodu
plexingoptions,thereisasingleslotandadualversionoftheBIU:
 TheDBI3xx(wideversion)includesanexternalalarmconnector(DB9)andrequirestwoMFUslots.
 TheDBI3xxC(compactversion)doesnothaveanexternalalarmconnector(DB9),andusesonlyoneMFU
slot.
Figure 5
BIU
ALM
ON
DL/UL BTS 1
TP UL 1
TP UL 2
DL OUT 1
UL IN 1
DL OUT 2
UL IN 2
DL/UL BTS 2


BIU
ALM
ON
DL/UL BTS 1
TP UL 1
EXTERNAL
ALARM
TP UL 2
DL OUT 1
UL IN 1
DL OUT 2
UL IN 2
DL/UL BTS 2


DBI3xxC
DBI3xx
Base Station Interface Unit (BIU)
Functional description
TheBIUhasfo
urSMAports(femaletype)toconnecttheRBS/BTS.
 DuplexedversionshavecombinedDL/ULconnectorsusedtoconnecttotheRBS,andthereareULtest(TP)
connectorsthatcanbeusedtomonitorthesignaloutfromtheBIU.
 Non‐duplexed(simplex)versionshavethe testconnectorsreplacedbyULconnectorsandthenormally
combinedUL/DLconnectorsarereplacedbyDLonlyconnectors.