Ericsson MINI-LINK TN R3 ETSI Technical Description page 89

PCI TDM
Figure 73 Tx Equipment Protection, Working and Hot Standby
4.6.2.2 Tx Equipment Protection Hot Standby
This protection case also involves the TDM Tx switch and the TA switch.
The difference from Tx Equipment Working Standby is that only one RAU is
active. Hence, Tx must be switched off in the malfunctioning Radio Terminal
and switched on in the standby. This is controlled by the DP in the Control and
Supervision block of the MMU and communicated in the RCC.
Alarms generated in the RAU and MMU are monitored by the NPU, which based
on the alarm severity commands the TDM and TA switches as appropriate.
The switching principles are illustrated in Figure 73 on page 83.
4.6.2.3 Radio Segment Protection
This protection case involves a Diversity switch in each MMU, providing hitless
and error free traffic switching in case of radio channel degradation. It is also
used as equipment protection in case of a signal failure in the RAU Rx parts.
4/1555-CSH 109 32/1-V1 Uen B 2007-09-14
TDM
Multiplexer/
Demultiplexer
Radio Frame
Multiplexer
TA
Switch
Control and
Supervision
BPI
TA
Switch
Radio Frame
Multiplexer
TDM
Control and
Multiplexer/
Demultiplexer Supervision
NPU
Node
Processor
MMU A
Cable
Modulator
Interface
Tx On/Off
RCC
(Hot Standby)
MMU B
Cable
Modulator
Interface
Tx On/Off
RCC
(Hot Standby)
Radio Terminals
RAU A
RAU B
6666
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