Communication protocols
From saref-portal#3
SAREF4ENVI, SAREF4WEAR, SAREF4LIFT, SAREF4WATR, all define some kind of communication protocols and interfaces.
Only SAREF4LIFT uses the patterns from SAREF4SYST for describing communication protocols. See Figure 18 at https://saref.etsi.org/saref4lift/v1.1.1/
SAREF4EHAW defines s4ehaw:CommunicationProtocol
SAREF4ENVI defines s4envi:usesCommunicationInterface and s4envi:usesCommmunicationProtocol, and s4envi:System, which from its definition read more like a CommunicatingSystem
DP s4watr:operatesAtRadioFrequency would best be applied to some ontology of communication protocols. Other extensions SAREF4LIFT, SAREF4EHAW, SAREF4WEAR, do define communication interfaces and protocols. Some harmonization would be required.