Thanks for all yr valuable feedback and inputs
To wrap up let me share my findings and draw a conclusion:
Total SATCOM failure means CPDLC is degraded
ICAO ATC plan Item 10 Equipment calls for J deletion
ICAO ATC plan Item 18 Other Info: RNP is downgraded to 10
DAT has S deleted
Thanks for all yr help
The OC
SI Even with SATCOM inop CPDLC operated on VDL is limited by range
and de-facto non-functional