A Semantic Definition Format for Data and Interactions of Things
charter-ietf-asdf-00-01

Background

Data and interaction models of IoT devices today exhibit unneeded
diversity between different industry ecosystem standards development
organizations (SDOs), hindering interoperability across these ecosystems
with little discernible benefit from the diversity. Early in 2019, One
Data Model (OneDM, https://onedm.org) was started to bring several IoT
SDOs and IoT device and platform vendors together under a broad,
multi-party liaison agreement, with a goal of arriving at a common set of
data and interaction models that describe IoT devices. Ideally, for every
class of IoT device, there is just a single model selected/created by the
participating organizations, which everyone can adopt.

As a common language for writing down these models, the Semantic
Definition Format (SDF) was created, which can represent IoT Things,
their composition from reusable Objects, their Interaction Affordances
(Properties, Actions, Events), and the data models relevant to describe
these Affordances. SDF represents these models in JSON, enabling re-use
of specification formats such as CDDL (RFC8610) and the formats proposed
at json-schema.org and their tooling, for describing both the SDF format
itself and the structure of the data to be modelled in SDF.

Some 200 models in SDF format have been contributed by participating
ecosystems; new models are being submitted continually. Version 1.0 of
the SDF specification was published on the OneDM github repository and as
draft-onedm-t2trg-sdf. OneDM is now focusing on consolidating the body
of submitted models and developing processes for arriving at harmonized
models that span different industry ecosystems in a common way; they look
to the IETF for further development of SDF 1.0 into a high-quality
specification.

The ASDF Working Group

The objective of the ASDF working group is to develop SDF to an
IETF-quality specification for Thing Interaction and Data Modelling,
working with experts from OneDM and its contributing organizations. On
the way to that specification, further functionality requirements will be
addressed that emerge in the usage of SDF for model harmonization.

The ASDF WG will work closely with the CBOR WG, home of the CDDL
specification. It will also engage the still active mailing list of the
concluded JSON WG. Recent proposals to form an IRTF formal description
techniques (FDT) Research Group might lead to another collaboration
partner. The Thing-to-Thing Research Group (T2TRG) and its WISHI program
can be instrumental in engaging researchers and other SDOs in this space,
such as W3C Web of Things, which is working on Thing Description
Templates and related specifications.

The working group has one deliverable: the SDF specification. It is not
currently foreseen that this will be split into multiple documents, but
that is also not excluded. The working group might choose to develop the
specification by evolving it in a regular rhythm, with new "Implementation
Drafts" -- versions specifically targeted for implementation and
interoperability testing -- available about bi-monthly.