Page 1138 - 5G Basics - Core Network Aspects

2 Transport aspects

15.4 OMS-O description

The following OMS-O information elements are defined:
 OMS-FDI-P
 OMS-FDI-O
 OMS-BDI-P

 OMS-BDI-O
 OMS-PMI
 OMS-MSI

15.4.1 OMS forward defect indication – Payload (FDI-P)
For OMS section monitoring, the OMSn-FDI-P signal is defined to convey in the downstream direction the
OMS-P signal status (normal or failed).

15.4.2 OMS forward defect indication – Overhead (FDI-O)
For OMS section monitoring, the OMSn-FDI-O signal is defined to convey in the downstream direction the
OMS-O signal status (normal or failed).

15.4.3 OMS backward defect indication – Payload (BDI-P)
For OMS section monitoring, the OMSn-BDI-P signal is defined to convey in the upstream direction the
OMS-P signal fail status detected in the OMS-P termination sink function.
15.4.4 OMS backward defect indication – Overhead (BDI-O)

For OMS section monitoring, the OMSn-BDI-O signal is defined to convey in the upstream direction the
OMS-O signal fail status detected in the OMS-O termination sink function.

15.4.5 OMS payload missing indication (PMI)

The OMS PMI is a signal sent downstream as an indication that upstream at the source point of the OMS-P
signal none of the frequency slots contain an optical tributary signal, in order to suppress the report of the
consequential loss of signal condition.

15.4.6 OMS multiplex structure identifier (MSI)
The OMS multiplex structure identifier (MSI) signal encodes the OCh-P/OTSiG multiplex structure and
occupied frequency slots in the OMS-P at the source end point. It is sent downstream to enable detection
of OCh-P/OTSiG multiplex structure configuration mismatches between sink and source end points.

The OMS multiplex structure identifier (MSI) signal also encodes the media channel structure which is
independent of the OCh-P/OTSiG in the OMS-P at the source and sink end points. It is sent downstream to
enable detection of media channel structure configuration mismatches between sink and source end
points.
The OMS MSI is defined for flex grid MOTUm interfaces. Fixed grid MOTUm interfaces may not support the
OMS MSI. Flex grid MOTUm interfaces designed prior to Edition 5.0 of this Recommendation may not
support the OMS MSI.

15.5 OCh-O and OTSiG-O description
The following OCh-O and OTSiG-O information elements are defined:
 OCh-FDI-P and OTSiA-FDI-P

 OCh-FDI-O and OTSiA-FDI-O
 OCh-OCI and OTSiA-OCI
 OTSiA-BDI-P

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