R4Interoperability
This chapter in shortThe architecture, data models and open standards that let systems work together.
Highlight what applies to
R4.1Reference architecture
Applies toData providersData consumersService & compute providers
In shortParticipants, portal, provider node, trust services and federated data spaces, and how they fit together.
Reference architecture
Participants work through the EMPOWER-X portal. Publication, ordering and compute-to-data run on the Ocean Enterprise node, and identities are checked against Gaia-X trust services. Federated data spaces exchange catalogues and orders under federation agreements.
R4.2Data models and reference datasets
Applies toData providersService & compute providers
In shortOffers say which data model and version they use, so a consumer knows what it will receive before ordering.
Data models and reference datasets
- Offers use the data models adopted by the Technical Committee and published in the technical annex. For energy data these are based on SAREF4ENER, IEC CIM and the Smart Data Models energy domain; for municipal and district data, on the OASC Minimal Interoperability Mechanisms.
- Offers state the model and version they use. Where no adopted model fits, the provider documents its schema in the offer.
- Common reference datasets are used for codes and units: EU NUTS and LAU codes for territories, SI units, and the code lists listed in the technical annex.
Data model governance
The Technical Committee keeps the list of adopted models and reference datasets, versions it, and announces breaking changes at least 90 days ahead. Participants propose new models or versions through the change process in R1.6.
Machine-readabledata-models/data-models.json
R4.3Open standards
Applies toData providersService & compute providersBodies & operator
In shortOpen standards for identity, catalogue, policies and exchange, so nothing locks a participant in.
Open standards
| Area | Standard |
|---|---|
| Identity | W3C Decentralized Identifiers; W3C Verifiable Credentials; Gaia-X Trust Framework ontology |
| Catalogue | DCAT-AP, in the version adopted by the Technical Committee, alongside Ocean Enterprise metadata (DDO) |
| Policies | Machine-readable policies expressible in ODRL 2.2 (R5.2) |
| Data exchange | Ocean Enterprise provider and compute-to-data APIs; Dataspace Protocol for exchanges with EDC-based data spaces through partner connectors |
| Data models | As in R4.2 |
R4.4Data exchange and APIs
Applies toData providersData consumers
In shortInside EMPOWER-X, you order on the ledger and the provider node grants access. There is no separate contract negotiation, because the terms are fixed in the offer.
Data exchange protocol and APIs
- Inside EMPOWER-X, exchanges follow the Ocean Enterprise protocol: a consumer orders an offer on the ledger, and the provider node grants access (download, service call or compute-to-data job) after checking the order and the policy.
- Ocean Enterprise has no separate contract-negotiation step: the terms are fixed in the offer and accepted with the order.
- Exchanges with data spaces built on Eclipse Dataspace Components (EDC) use the Dataspace Protocol, including its contract negotiation, through connectors operated by the partners involved. These exchanges are documented separately and are not recorded as EMPOWER-X marketplace orders.