3 Board
M900/M1800 BTS3X Series Base Transceiver Station
Hardware Description Manual
3-52
Huawei Technologies Proprietary
Issue 01 (2006-11-18)
3.17 TDU
The hardware version of the TDU described in this section is REV.F. DIP switch settings of other TDU
versions are the same as that of REV.F.
3.17.1 Functions
The major function of the timing distribution unit (TDU) is to receive clock signals from the
TMU: SREF (3.25 MHz), OBCLK (2.16 MHz), FCLK (216.7 Hz) and FN, and transfer them
to each TRX in the cabinet and each unit in other cabinets. The TDU also transfers other
signals, such as alarm signals.
In the BTS3006A and the BTS3012A, the clock of extension cabinet is driven by the TCU.
For detailed information, refer to the
M900/M1800 BTS3012A Base Transceiver Station
Technical Manual Auxiliary System
.
3.17.2 Panel
There are 11 ports on the TDU.
shows the TDU layout.
Figure 3-37
TDU layout
DCF2
CKB2
CKB1
TRB2 TRB1 TRA2 TRA1 TME1
EAC2
EAC1 DCF1
lists detailed information about ports on the TDU.