M900/M1800 BTS3X Series Base Transceiver Station
Hardware Description Manual
3 Board
Issue 01 (2006-11-18)
Huawei Technologies Proprietary
3-69
Figure 3-45
TMU functional structure
MCK
OMU
BIU
EAC
DBUS
CBUS
MM I
BSC
MCK
Active TMU
Environment
monitoring equipment
Abis
TCU
Standby TMU
BIU
TBUS,CBUS,DBUS
Site Maintenance
Terminal System
RS485
External clock
BSC: Base Station Controller
TMU: Timing/Transmission and Management Unit
BIU: BTS Port Unit
OMU: Operation and Maintenance Unit
TCU: Temperature Control Unit
EAC: External Alarm Collection Module
MCK: Main Clock Module
DBUS: Internal Data Bus
CBUS: Internal Control Bus
TBUS: Internal Timing Bus
BIU
The BIU has the following functions:
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Realizing the conversion and reverse conversion from digital signals on the BTS internal
highway to HDB3 code on E1 cables.
!
Exchanging the timeslots on the Highway to realize the flexible configuration of
timeslots.
!
Extracting clock signals from the upper level and support the input of external clock.
!
Outputs accurate clock through phase-locking and frequency dividing.
!
Synchronizing data transmission of the internal bus.
!
Generating free run clock in case of no upper-level clock available due to the failure of
E1s or the BSC.
!
Synchronizing the data transmission of internal bus and reports generated alarms to the
OMU.
!
A BIU can provide up to four channels of E1. In a single cabinet, the BIUs of two TMUs
are the extension of each other. Eight channels of mutually extended E1 data can realize
full exchange.
!
E1 ports on the BIU can be used to connect the BSC or the BTS at the upper or lower
level. It supports star, tree, chain and ring topologies of the BTS.
OMU
The OMU is the core control and processing unit of the TMU. It can be used to configure the
performance parameters of various units of the BIU and the MCK, receive fault alarms, and
implement alarm management. With the internal control bus and the communication between