Ericsson MINI-LINK TN R3 ETSI Technical Description page 88

MINI-LINK TN R3 ETSI
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4.6.2.1 Tx Equipment Protection Working Standby
This protection case involves two types of switch, TDM Tx switch and Traffic
Alignment (TA) switch.
The TDM Tx switch is a logical switch used to switch over the traffic to the
redundant MMU, in case of a failure in the TDM Multiplexer part of the active
MMU. This is accomplished by the NPU configuring the MMUs to listen to a
certain TDM bus slot.
The TA switch is used to feed the multiplexed traffic signals to the Radio Frame
Multiplexer block in both MMUs, which is a condition for being able to perform
hitless switching in the receiving end.
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.
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Tx Equipment Protection Working Standby
Tx Equipment Protection Hot Standby
Radio Segment Protection
Rx Equipment Protection
4/1555-CSH 109 32/1-V1 Uen B 2007-09-14