9500 MXC User Manual
3DB 23063 ADAA - Rev 004 July 2007 Vol. II-3-97
Service Restoration Times for Hot Standby and Diversity
Service restoration times (detection, switching and recovery) for a switch event
are:
Transmit Switch
• 200 ms maximum for a local alarm
• 20 seconds maximum for a remote-end command (silent transmitter event)
Receive Switch
• Switching is hitless for all alarm events except for a failure at the bus-drive
protection switch within the online designated RAC.
• 200 ms maximum for a bus-drive switch.
Dual Protection Switching Criteria
Currently dual protection is only offered with a frequency diversity master,
which means that only Rx (to the backplane bus) is switched; both subordinate
protected links are online transmitting (transmit protection criteria do not apply).
For restoration times refer to: Service Restoration Times for Dual Protection on
page 3-98.
Receive Switching Criteria, Frequency Diversity Master
RAC bus-drive switching is initiated between the two subordinate links under the
following conditions:
• RAC plug-in is missing or incorrect
• RAC component failure:
• RAC software load failure
• EEPROM failure
• Rx path failure:
• Rx synthesizer not locked
• RF IF synthesizer not locked
• Demodulator not locked
• ODU Tx cable IF synthesizer not locked
The 20 second period is set to prevent unwanted switching caused by
momentary path fade or other switching events.
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