  Nowadays, there are plenty of data sources generating massive amounts of
information that, combined with novel data analytics frameworks, are meant to
support optimisation in many application domains. Nonetheless, there are still
shortcomings in terms of data discoverability, accessibility and
interoperability. Open Data portals have emerged as a shift towards openness
and discoverability. However, they do not impose any condition to the data
itself, just stipulate how datasets have to be described. Alternatively, the
NGSI-LD standard pursues harmonisation in terms of data modelling and
accessibility. This paper presents a solution that bridges these two domains
(i.e., Open Data portals and NGSI-LD-based data) in order to keep benefiting
from the structured description of datasets offered by Open Data portals, while
ensuring the interoperability provided by the NGSI-LD standard. Our solution
aggregates the data into coherent datasets and generate high-quality
descriptions, ensuring comprehensiveness, interoperability and accessibility.
The proposed solution has been validated through a real-world implementation
that exposes IoT data in NGSI-LD format through the European Data Portal (EDP).
Moreover, the results from the Metadata Quality Assessment that the EDP
implements, show that the datasets' descriptions generated achieve excellent
ranking in terms of the Findability, Accessibility, Interoperability and
Reusability (FAIR) data principles.
