Settings, Protection And Atpc - Alcatel-Lucent 9500 MXC User Manual

Settings, Protection and ATPC

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If just one of the co-channel links is 1+1 protected, a failure of XPIC cross-connect between the 1+0
RAC 40 and its 1+1 XPIC partner may cause both V and H receive streams to error as the discrimination
provided under XPIC would be lost. An unlikely double-failure event would be needed to cause the same
error if both co-channel links are 1+1 protected.
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Optimum XPIC interference cancellation performance requires equal, or near equal V and H receive
signal levels.
3DB 23063 ADAA - Rev 004 July 2007
• Each RAC 40 in a co-channel XPIC pairing must be configured for the same
frequency, capacity and modulation.
• A special Tx mute function applies if one of the receive RACs fails, the RAC is
withdrawn, or the XPIC cables are removed or incorrectly connected. Refer to
Remote Tx Mute.
• Co-channel links may also be hot-standby or diversity protected using two
RAC 40s per vertical and horizontal feed. The protection partners must be
installed in the same INUe and slot-located according to INU/INUe RAC
protection rules.
• Where co-channel links are to be 1+1 protected, both must be 1+1
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protected .
• The RAC 40 assigned to each polarization is 1+1 protected by adding a RAC
40 protection partner in the CT Protection screen.
• For hot-standby or frequency diversity protection using a single dual
polarized antenna at each end, remote-mounted equal-loss couplers
be used to mount the ODUs.
• Similarly, for space diversity operation all four antennas must be of the same
size (have the same gain).
• The protected V and H links operate as two independent links - the standard
protection switch criteria for protected links apply. Refer to Hot-standby and
Diversity Switching Criteria on page 3-93.
• Similarly, the Remote Tx mute functions apply where both RACs of a
protected pair fail, are withdrawn, or have their XPIC cables removed or
incorrectly connected. Refer to Remote Tx Mute.
• RAC 40s can be operated in single channel/non-XPIC mode to provide an
upgrade path to co-channel operation without hardware changes.
• ATPC must be OFF on both co-channel links. (Receive signal level
measurements are affected by the interference caused on one link by the other,
which results in abnormal ATPC action).
9500 MXC User Manual
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must
Vol. II-3-105