User Manual

ArchitectureNortel Networks Confidential 3–31
S8000/S8002/S8006 BTS Reference Manual
3.4 DRX functional architecture
The DRX board has a digital part, a radio part and a power supply board
(Figure 3–9)
3.4.1 DRX digital part
The DRX digital part consists of four units:
the Advanced MaNagement Unit (AMNU) which manages the DRX
the Digital Control Unit for eight chanels (DCU8) which is the signal processing
unit
the Time Base Unit (BDT) which manages the GSM_TIME for the DRX
TX logic which is the interface with the transmission part in the DRX Radio
board
3.4.1.1 AMNU unit
The AMNU unit manages the DRX. It manages the eight time slots of an TDMA
frame, and the radio signaling functions.
These functions can be broken down into communication functions (RSL), on the
one hand, and operating and maintenance functions (O&M), on the other (see
Figure 3–10).
Communication functions
Communication functions include:
routing functions
concentration functions
Routing functions
The TDMA frame management unit routes messages from the BSC. The messages
arrive on the RSL and can be broken down into two categories:
messages concerning processing of a single time slot
messages concerning all the time slots in the TDMA frame
Concentration functions
There are two types of messages:
transparent messages
non–transparent messages