Reference Manual

Unit Description, DXU-21
6.3 Functions
The DXU serves as the Central Main CPU node and its main functions
are:
• Provides the RBS with an interface to the transport network
through four fixed E1/T1 transmission ports.
•
Handles incoming traffic, controls and supervises information and
sends it to its destination within the RBS.
• Provides frequency reference signals and clock signals for circuits
within the RBS.
• Stores and executes RBS SW. SW is stored on a removable flash
card.
•
Controls the climate and power system.
6.4 External Interfaces
P007456C
View of backplane
Power supply
External alarm
Local bus
Timing bus
Local
Fault
Operational
RSB Fault
Ext Alarms
EPCbus fault
EOMbus fault
DXU reset
Local Remote
Test
EPC
V7-12
V 1-6
Status
Port A
Port B
Port A
Port B
Por t C
Por t D
Status
Por t C
Por t D
OMT
ESB
GPS
EOM
Compact Flash Card
Figure 65 DXU-21, front panel and backplane
G.703 Interface
The four G.703 interfaces are connected to the BSC (Protocol GSM-
Abis) or to cascaded base stations. In cascade mode, this interface can
control an external bypass relay. Unused time slots can be through-
connected to a succeeding base station. The communication speed in E1
interfaces is 2 Mbit/s and in T1, 1.5 Mbit/s.
120 (421)
EN/LZT 720 0008 R1A
2001-06-26
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