Alcatel-Lucent 9500 MXC - Page 490

Chapter 8. Protection
Vol. IV-8-8 Alcatel-Lucent
• A 9500 MXC ring Node may have one or both (east and/or west) ring links
configured for 1+1 protection.
3. 1+1 protection may be applied to co-channel ring links.
• Using RAC 40s two concentric, autonomous rings of equal capacity/
bandwidth can be configured to operate on the same frequency using the V
and H polarizations.
• Where co-channel links are to be 1+1 protected, both links (V and H) must
protected.
• For more information on RAC 40 ring operation, with and without 1+1
protection, refer to Co-channel Operation on page 3-102, Volume II,
Chapter 3.
4. A ring-wrap will occur when:
• The path supported by a 1+1 link exhibits a path fail condition. The path
failure switching criteria are the standard ring path failure criteria, with the
exception of the 10
-6
BER option
3
. Refer to Radio Wrap Conditions on
page 3-98, Volume II, Chapter 3.
• The 1+1 link triggers an online Rx and/or Tx switch event. Refer to
Hot-standby and Diversity Switching Criteria on page 3-93, Volume II,
Chapter 3.
• The 1+1 link triggers a demodulator not locked alarm on both RACs.
• The decision to unwrap is made when the ring error-free timer times out and, if
set, the time of day timer. Refer to Unwrap Timers on page 3-99, Volume II,
Chapter 3.
• Ring wrap and unwrap times for 1+1 ring links are identical to 1+0 ring links.
Refer to Wrap and Unwrap Times on page 3-99, Volume II, Chapter 3.
• The protection guard timer mechanism prevents switching oscillation at the ring
level. Refer to Switching Guard Times on page 3-93, Volume II, Chapter 3.
• Event Browser entries are created for switch events on the ring and subordinate
space diversity link(s).
Figure 8-1 illustrates the protection management hierarchy where both east and
west links on a Node are space diversity.
Figure 8-2 illustrates the heirachy where one ring link is space diversity, and the
other 1+0.
• Space diversity protection is subordinated to ring protection.
• A subordinate space diversity link operates as a standard link according to
standard ring requirements.
3
For 1+1 ring links the 10
-6
BER ring wrap/unwrap option is not supported.