Alcatel-Lucent 9500 MXC, User Manual, Page: 869 / 916

9500 MXC User Manual
3DB 23063 ADAA - Rev 004 July 2007 Vol. VI-F-13
Figure F-5.
Hot Standby Protection
Space Diversity
Space diversity protection operation is identical to hot standby except for the use
of two vertically separated antennas. The upper antenna should be installed with
the online Tx (primary RAC/ODU).
Frequency Diversity
Frequency diversity has both transmitters and receivers operational.
The Tx diversity bus is used to ensure identical frame synchronization on the two
parallel transmit streams, to enable hitless frame-by-frame selection at the
receive end.
Transmit direction:
• DAC Tx drives to the TDM bus.
• The primary RAC (online Tx) uplifts DAC Tx data from the TDM bus and
delivers it to its ODU. It also sends its same (framed) data stream to the
secondary RAC via the Tx diversity bus.
• The secondary RAC/ODU transmits the data (on a different frequency).
Receive direction:
• Both primary and secondary RACs receive the transmitted data, but only the
secondary RAC (online Rx), drives to the TDM bus (secondary RAC is default
Rx online).
• Data from the primary RAC Rx is routed to the Rx diversity bus, where it is
uplifted by the secondary RAC.
Online
Tx
Rx Primary RAC Secondary RAC
TDM Bus
Tx Diversity Bus
Rx Diversity Bus
DAC
Tx
Rx
ODU
ODU
Coupler
Online
Rx
Tx
Tx PA Mute