1. Context and scope
In a disaggregated environment when two different entities are in charge of managing optical terminals (OT) and open line systems (OLS) separately, the demarcation points between them need to be clearly defined.
For OTSi over NMC services in disaggregated environments, the power management when creating a service is needed for proper signal handover between management entities.
However, currently tapi-photonic-media.yang model is not complete for this UC.
With OLS Controller
TAPI
E2E WDM Controller
TAPI
TAPI, OpenConfig…
OLS Controller
TAPI, OpenConfig…
OpenConfig OT
MUX
WSS
AMP
WSS
MUX OT
Demarcation point
Demarcation point
Open Line System (OLS)

2. Use case 1: Power management for NMC service provisioning
NMC connectivity service (cs) provisioning based on OTSI capabilities information
The use case intends to cover a CS provisioning between two NMC service-interface- points (SIPs) where the OLS controller exposing those NMC’s SIPs does not have information about the OTSi signal which is going to be filtered across the target NMC.
Based on the OTSi transmitter/receiver capabilities, the request for the NMC CS may be augmented to include:
Spectrum: upper/lower frequency which defines the spectrum band occupied by the channel. Already covered
Power: minimum/maximum power which is going to be received/transmitted through the media channel, this information can be used for channel power equalization. Not covered, being assessed in this proposal.
Physical impairments path constrains: OSNR and any other physical impairment constrains imposed by the OTSi receiver sensibility, which may constrain the NMC’s path through the OLS. Not covered, but left for further step.

3. Recommendation ITU-T G.698.2
Amplified multichannel dense wavelength division multiplexing applications with single channel optical interfaces

4. Use case 1: Power management for NMC service provisioning
PHTN NNI
PHTN NNI
1.SIP OTSi capabilities (Not-defined yet):
- supportable-maximum-output-power
- supportable-minimum-output-power
- tolerable-maximum-input-power
- tolerable-minimum-input-power P Q
2.PHTN CSEP characterization for NMC physical impairments validation:
Not-defined yet:
intended-maximum-output-power
intended-minimum-output-power
Expected-maximum-input-power
Expected-minimum-input-power
TPND Node
TPND Node
OLS NBI Context X Y
PHTN Connectivity Service J K
3.SIP NMC capabilities (Not-defined yet):
- supportable-maximum-output-power
- supportable-minimum-output-power
- tolerable-maximum-input-power
- tolerable-minimum-input-power
Node
NodeEdgePoint
Device
Connectivity ServiceEndPoint
ServiceInterfacePoint
ConnectivityService
Connection
Link
Transitional Link
ConnectionEndPoint
MediaChannel ConnectionEndPoint
Network MC Connection
OLS Domain Node
NMC
NMC
NMC
PHTN Link
PHTN Link
OMS MC
OMS MC
OMS
PHTN Link
PHTN Link
PHTN Link
ROADM Node
OTS MC
ROADM Node
OTS MC
INLAMP Node
OTS MC
ROADM Node
PHTN Link
PHTN Link
PHTN Link

5. Proposed extensions for tapi-photonic-media.yang
NMC connectivity-service constrains counterparts
OTSI Capabilities
augment /tapi-common:context/tapi-common:service-interface-point: +--rw otsi-service-interface-point-spec +--ro otsi-capability +--rw supportable-maximum-output-power | +--ro total-power? decimal64 | +--ro power-spectral-density? decimal64 +--rw supportable-minimum-output-power +--rw supportable-maximum-input-power +--rw supportable-minimum-input-power | +--ro total-power? Decimal64 | +--ro power-spectral-density? Decimal64
augment /tapi-common:context/tapi-connectivity:connectivity-context/tapi-connectivity:connectivity-service/tapi-connectivity:end-point:
+--rw media-channel-connectivity-service-end-point-spec
+--rw mc-config
+--rw power-constrains
+--rw maximum-output-power
| +--rw total-power? decimal64
| +--rw power-spectral-density? Decimal64
+--rw minimum-output-power
| +--rw power-spectral-density? decimal64
+--rw maximum-input-power
+--rw minimum-input-power
| +--rw total-power? Decimal64
These two groups of parameters can be seen as the two sides of the same coin. The power constrain values within the CSEP of the NMC’s CS request, depends on the OTSI transmission/receiver capabilities/requirements exposed by the OT device.

6. Proposed extensions for tapi-photonic-media.yang
Regarding the tapi modelling itself, the current power-properties-pac YANG definition can be reuse for all previously proposed attributes.
grouping power-properties-pac {
leaf total-power {
type decimal64 {
fraction-digits 7; }
description "The total power at any point in a channel specified in dBm.";
leaf power-spectral-density {
config false;
description "This describes how power of a signal is distributed over frequency specified in nW/MHz";
description "Indication with severity warning raised when a total power value measured is above the threshold.";

7. Use case 1: Power management for NMC service provisioning
Limitation: the power attenuation of the fiber between OT physical line interface and OLS Add/Drop port is not characterized.
Fiber characteristics:
Fiber type (e.g., SSMF)
Length (in Km.) -> Needed to calculate attenuation.
Loss Coefficient (dB/Km) -> Needed to calculate attenuation
PMD
Chromatic Dispersion

8. Use case 1: Power management for NMC service provisioning
PHTN NNI
2. OTS Connection characterization:
Expected-loss (dB)
PHTN NNI P Q
OLS Domain Node
TPND Node
TPND Node
PHTN Link
OLS NBI Context X Y
PHTN Connectivity Service J K
Node
NodeEdgePoint
Device
Connectivity ServiceEndPoint
ServiceInterfacePoint
ConnectivityService
Connection
Link
Transitional Link
ConnectionEndPoint
MediaChannel ConnectionEndPoint
Network MC Connection
OLS Domain Node
NMC
NMC
NMC
PHTN Link
PHTN Link
OMS MC
OMS MC
OMS
PHTN Link
PHTN Link
PHTN Link
ROADM Node
OTS MC
ROADM Node
OTS MC
INLAMP Node
OTS MC
ROADM Node
PHTN Link
PHTN Link
PHTN Link