A Semantic Definition Format for Data and Interactions of Things (asdf) Internet Drafts

      
 Semantic Definition Format (SDF) for Data and Interactions of Things
 
 draft-ietf-asdf-sdf-18.txt
 Date: 28/02/2024
 Authors: Michael Koster, Carsten Bormann, Ari Keranen
 Working Group: A Semantic Definition Format for Data and Interactions of Things (asdf)
 The Semantic Definition Format (SDF) is a format for domain experts to use in the creation and maintenance of data and interaction models that describe Things, i.e., physical objects that are available for interaction over a network. An SDF specification describes definitions of SDF Objects/SDF Things and their associated interactions (Events, Actions, Properties), as well as the Data types for the information exchanged in those interactions. Tools convert this format to database formats and other serializations as needed. // The present revision (-18) adds security considerations, a few // editorial cleanups, discusses JSON pointer encodings, and adds // sockets to the CDDL for easier future extension.

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A Semantic Definition Format for Data and Interactions of Things (asdf)

WG Name A Semantic Definition Format for Data and Interactions of Things
Acronym asdf
Area Applications and Real-Time Area (art)
State Active
Charter charter-ietf-asdf-02 Approved
Status update Show Changed 2020-06-25
Document dependencies
Additional resources Issue tracker, Wiki, Zulip Stream
Personnel Chairs Michael Richardson, Niklas Widell
Area Director Francesca Palombini
Mailing list Address asdf@ietf.org
To subscribe https://www.ietf.org/mailman/listinfo/asdf
Archive https://mailarchive.ietf.org/arch/browse/asdf/
Chat Room address https://zulip.ietf.org/#narrow/stream/asdf

Charter for Working Group

Background

In 2019 One Data Model (OneDM) 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. After some exploratory work this resulted in a successful proposal to create the ASDF WG.

As a common language for writing down these models, the Semantic Definition Format went through the IETF process, producing (draft-ietf-asdf-sdf). This SDF Base specification has now reached WG Consensus, to be published. SDF represents these models in JSON, enabling re-use of specification formats such as CDDL (RFC 8610) 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.

SDF does not directly address data serialization. Instead, SDF focuses solely on modeling the structure and semantics of the data being exchanged. Consequently, the task of data serialization (including RPC semantics) is delegated to other standards, which are typically established by existing IoT SDOs.

The ASDF Working Group

The ASDF WG has developed SDF into a standards-track specification for thing interaction and data modeling. In the process of developing this specification, further functional requirements have emerged that can be addressed as extensions to the base SDF specification.

The ASDF WG will liaise with OneDM and other relevant organizations. ASDF will extend SDF to cover the following standard track extensions:

  • modeling of links and relationships between elements of models,

  • modeling of non-affordance attribute (e.g., location) information/interaction for digital twins where the corresponding physical objects can be described with SDF,

  • additional SDF modeling mechanisms to enable property mapping between additional IoT SDOs' objects (including instances, and types), and

  • information/interaction modeling and protocol mappings to enable gateway interactions between IP and non-IP transports, with draft-brinckman-nipc-00 as a starting point.

To increase ease of use, ASDF WG will also complete work on the proposal for a Compact Notation for SDF.

As work evolves, ASDF will observe and may want to interact with IRTF Research Groups such as the Usable Formal Methods Research Group (UFMRG). ASDF will work with Thing-to-Thing Research Group (T2TRG) and its WISHI (Work on IoT Semantic/Hypermedia Interoperability, https://wishi.space) program to engage researchers and other SDOs in this space, such as W3C Web of Things, which is working on Thing Models and related specifications.

Milestones

Date Milestone Associated documents
Sep 2025 Submit to the IESG a standards track extension to SDF to allow for inclusion of physical information and other non-affordance attribute information/interactions as an SDF attribute (e.g., to provide modeling support for digital twins).
Aug 2025 Submit to the IESG a standards track specification on describing instances that are based on SDF models.
Aug 2025 Submit to the IESG a standards track extension which allows for industry specific attributes to be associated with a common SDF model.
May 2025 Submit to the IESG a standards track specification on how to use SDF to communicate over IP with non-IP based devices.
Jan 2025 Submit to the IESG a standards track document on Compact Notation for SDF.
Nov 2024 Submit to the IESG a standards track extension to SDF to describe relationships between elements of models (beyond sdfRef).
Sep 2024 Submit to the IESG a standards track extension to SDF to describe sdfTyped links.