Alcatel-Lucent 9500 MXC - 1+1 Protected Ring Links

Chapter 3. 9500 MXC Nodes
Vol. II-3-84 Alcatel-Lucent
As the maximum backplane bus capacity for a 9500 MXC node is 100xE1 or
128xDS1, this sets the upper limit of the combined capacity of the rings through
the node. In the Figure 3-51 example one ring operates at 32xE1, the other at
64xE1, for a combined bus capacity of 96xE1, leaving just 4xE1 spare capacity
on the intersection Node. Refer to Appendix E.
Fiber Ring Closing
One or more radio links in a ring can be replaced with a span of fiber optic cable
using the DAC 155oM. It maps 63xE1 or 100xDS1 from the TDM bus directly to
a single STM1/OC3 frame, to enable fiber closures without need for external
SDH/SONET muxes.
DAC 155oM uses SFP (small form-factor pluggable) short-range or long range
optic transceiver sub-assemblies to support fiber spans to 15 km or 40 km
respectively.
1+1 Protected Ring Links
An 9500 MXC Super-PDH ring protected network can be enhanced with one or
more 1+1 protected links.
• 1+1 protection of a ring-protected link is normally implemented to provide path
protection as distinct from equipment protection. Therefore space diversity
(SD) is the required/recommended 1+1 protection mode
7
.
• One, some or all links on the ring may be 1+1 protected.
• An 9500 MXC ring Node may have one or both (east and/or west) ring links
configured for 1+1 protection.
• 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.
• A ring-wrap will occur when:
7
Hot-standby can be configured, but unlike space diversity offers no protection against path fade events.
However, should ring 1+1 operation with hot-standby links be required, its CT configuration is identical
to space diversity.