Ericsson RBS 2106 Hardware Reference Manual page 184

Radio Configurations
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No new antennas are required.
 2QH 'XSOH[ $QWHQQD 5;7;
The TDMA RBS may be equipped with only one TX/RX antenna. The
recommendation in this case is to add two antennas for the dTRU based RBS.
One RX signal from the dTRU based RBS is supplied to the TDMA RBS, thus
adding RX diversity to the TDMA RBS.
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 7ZR 6HSDUDWH 'XSOH[ $QWHQQDV
If two separate duplex antennas are already in use, the recommendation is to
install new antennas for the dTRU based RBS and not use co-siting at all.
86 (90)
TX RX RX
TDMA RBS
6HSDUDWH 7; DQG WZR VHSDUDWH 5; DQWHQQDV ZLWK 70$V
TX/RX
TDMA RBS
2QH GXSOH[ DQWHQQD 5;7;
TX
Co-sited
RX A
TDMA RBS
RX B
TX/RX
Co-sited
TDMA RBS
RX A
RBS 2106 and RBS 2206
TX/RX TX/RX
dTRU Based
RBS
P008527A
TX/RX TX/RX
dTRU Based
RBS
P008503A
EN/LZT 720 0318 Uen R1A