Chapter 3. 9500 MXC Nodes
Vol. II-3-94 Alcatel-Lucent
• Service Restoration Times for Hot Standby and Diversity on page 3-97
Transmitter Switching
Transmit switching for hot-standby and space diversity is not hitless; service is
restored within 200 ms. Transmit switching for frequency diversity is hitless
providing the online Tx RAC is not removed.
The online Tx RAC manages the Tx protection switch function, and is
transferred between RACs to always be with the online Tx RAC.
For hot-standby and space/frequency diversity the default protection
configuration has the primary RAC online Tx and the secondary RAC online Rx.
• Only the online Tx is operational for hot-standby and space diversity.
• Both online Tx and standby Tx are operational for frequency diversity. The
online Tx is managing Tx traffic synchronization.
• Switching from the online to standby transmitter will not be initiated if the
standby transmitter has failed, or the standby Tx RAC has been removed or
replaced by an incorrect plug-in. Similarly, a switch will not be initiated if the
ODU associated with the RAC has failed or is disconnected.
• When a switch has occurred, protection management remains with what was the
offline transmitter. The primary-designated RAC (default online Tx) is not
automatically returned to online transmit on repair or replacement
Transmit Switching Operation, Hot-standby and Space/Frequency
Diversity:
• The primary RAC is the default online Tx RAC.
• When a Tx switch from primary to secondary occurs, the online Tx status is
transferred from the primary to secondary RAC, and remains with the
secondary RAC; the primary-designated RAC is not automatically returned to
online on repair/replacement. The same process occurs in reverse - for a switch
from secondary RAC Tx online to primary RAC Tx online.
• For hot-standby and space diversity the online Tx status is changed for a
card withdrawal, RAC/ODU failure, or software load failure.
• For frequency diversity the online status is only changed for a card
withdrawal or software load failure.
• The switch of online Tx status is not hitless, service is restored within 200 ms.
Transmit Switching Criteria, Hot-standby and Space Diversity:
Transmitter switching to the alternate transmitter is initiated for the following
local alarm conditions:
• RAC plug-in is missing or incorrect
• RAC software load failure
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