Semantic Definition Format (SDF) Extension for Non-Affordance Information
draft-hong-asdf-sdf-nonaffordance-00
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| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Authors | Jungha Hong , Hyunjeong Lee | ||
| Last updated | 2025-04-08 | ||
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| Intended RFC status | (None) | ||
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| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
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draft-hong-asdf-sdf-nonaffordance-00
ASDF J. Hong, Ed.
Internet-Draft H. Lee
Intended status: Standards Track ETRI
Expires: 10 October 2025 8 April 2025
Semantic Definition Format (SDF) Extension for Non-Affordance
Information
draft-hong-asdf-sdf-nonaffordance-00
Abstract
This document describes an extension to the Semantic Definition
Format (SDF) for representing non-affordance information of Things,
such as physical, contextual, and descriptive metadata. This
extension introduces a new class, sdfNonAffordance, that enables
comprehensive modeling of Things and improves semantic clarity.
Status of This Memo
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This Internet-Draft will expire on 10 October 2025.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology and Conventions . . . . . . . . . . . . . . . . . 2
3. Motivation and Use Cases . . . . . . . . . . . . . . . . . . 3
3.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . 3
3.2. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . 3
4. SDF Extension for Non-Affordance Information . . . . . . . . 4
4.1. Concept . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.2. Syntax and Semantics . . . . . . . . . . . . . . . . . . 4
4.3. Examples . . . . . . . . . . . . . . . . . . . . . . . . 5
5. Security Considerations . . . . . . . . . . . . . . . . . . . 6
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
7. Normative References . . . . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
The Semantic Definition Format (SDF) has been instrumental in
standardizing the representation of affordances - properties,
actions, and events - of Things [I-D.ietf-asdf-sdf]. However, there
exists a gap in representing non-affordance information, such as
location, contextual metadata, and other descriptive elements that do
not directly pertain to device interactions. Addressing this gap is
crucial for comprehensive device modeling, especially in applications
like digital twins where holistic representations are essential.
This document describes a framework to extend the SDF by
incorporating non-affordance information. Integrating these
extensions allows SDF to provide a more comprehensive representation
of Things, thereby enhancing semantic descriptions.
2. Terminology and Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
* Non-Affordance: attributes of a Thing that are not directly
related to its interactive capabilities. This includes
descriptive metadata such as location, manufacturer details, and
other contextual information.
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3. Motivation and Use Cases
The integration of non-affordance information into the Semantic
Definition Format (SDF) addresses several critical needs in the
modeling of Internet of Things (IoT) devices. The key motivations
and corresponding use cases in the following subsections illustrate
the importance of this extension:
3.1. Motivation
In the current SDF framework, the primary focus is on defining
affordances - interactive elements such as Properties, Actions, and
Events. While this approach effectively captures the interactive
capabilities of a Thing, it overlooks essential non-interactive
attributes that are vital for a comprehensive device representation.
These non-affordance attributes encompass contextual information and
descriptive metadata, including dimensions, weight, location,
manufacturer details, and operational constraints. The absence of
standardized representation for such information can lead to
fragmented device models, hindering interoperability and the seamless
integration of devices across diverse IoT ecosystems.
3.2. Use Cases
3.2.1. Asset Management and Tracking
* Scenario: A logistics company utilizes IoT-enabled containers
equipped with sensors to monitor shipments.
* Requirement: To effectively manage and track these assets, it's
crucial to have standardized data on each container's physical
dimensions, weight capacity, and current location.
* Solution: Incorporating non-affordance information into SDF allows
for the uniform representation of these attributes, facilitating
efficient asset tracking, optimizing load planning, and ensuring
compliance with transportation regulations.
3.2.2. Environmental Context Awareness
* Scenario: A smart building management system integrates various
sensors and devices to monitor and control environmental
conditions.
* Requirement: Understanding the installation environment of each
device, such as room location, mounting position, and surrounding
materials, is essential for accurate data interpretation and
optimal system performance.
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* Solution: By extending SDF to include environmental context as
non-affordance information, the system can dynamically adjust
operations based on device placement and environmental factors,
enhancing occupant comfort and energy efficiency.
3.2.3. Regulatory Compliance and Certification
* Scenario: Medical devices deployed in healthcare facilities must
adhere to stringent regulatory standards and certifications.
* Requirement: Detailed documentation of each device's manufacturer,
model number, serial number, and certification information is
necessary for compliance audits and maintenance schedules.
* Solution: Embedding this non-affordance information within SDF
ensures that all relevant metadata is consistently available,
simplifying compliance reporting and facilitating timely
maintenance and recalls when necessary.
By integrating non-affordance information into SDF, these use cases
demonstrate how a more holistic device model enhances
interoperability, operational efficiency, and compliance across
various IoT applications.
4. SDF Extension for Non-Affordance Information
4.1. Concept
In the SDF, the primary focus has been on defining affordances -
interactive elements such as Properties, Actions, and Events - that
specify how external entities can interact with a Thing. However, to
achieve a more comprehensive representation of a Thing, it's
essential to include non-affordance information, which encompasses
attributes not directly related to interaction but crucial for
understanding the Thing's context and characteristics.
To address this need, we propose introducing a new class named
sdfNonAffordance within the SDF architecture. This class allows for
the inclusion of metadata such as physical dimensions, location,
environmental context, and manufacturer details.
4.2. Syntax and Semantics
The sdfNonAffordance is defined with attributes such as:
* name: Identifier for the non-affordance attribute.
* description: Textual explanation of the attribute.
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* type: Data type (e.g., string, number, object, boolean, array) of
the attribute value.
* unit: Applicable measurement unit, if relevant.
{
"sdfObject": {
"device": {
"sdfNonAffordance": {
"attribute-name": {
"description": "Attribute description",
"type": "data type",
"unit": "unit if applicable"
}
}
}
}
}
Figure 1: Structure of sdfNonAffordance in SDF
This structure ensures clarity and consistency in representing non-
affordance information.
4.3. Examples
4.3.1. Geospatial information
{
"sdfObject": {
"tracker-device": {
"sdfNonAffordance": {
"location": {
"description": "Geographical coordinates",
"type": "object",
"wgs84": {
"latitude": 60.1676,
"longitude": 24.9514
}
}
}
}
}
}
Figure 2: Example of geospatial information
4.3.2. TBD
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4.3.3. TBD
5. Security Considerations
TBD
6. IANA Considerations
TBD
7. Normative References
[I-D.ietf-asdf-sdf]
Koster, M., Bormann, C., and A. Keränen, "Semantic
Definition Format (SDF) for Data and Interactions of
Things", Work in Progress, Internet-Draft, draft-ietf-
asdf-sdf-23, 17 March 2025,
<https://datatracker.ietf.org/doc/html/draft-ietf-asdf-
sdf-23>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/rfc/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
Authors' Addresses
Jungha Hong (editor)
Electronics and Telecommunications Research Institute
218 Gajeong-ro, Yuseong-gu
Daejeon
34129
South Korea
Phone: +82 42 860 0926
Email: jhong@etri.re.kr
Hyunjeong Lee
Electronics and Telecommunications Research Institute
218 Gajeong-ro, Yuseong-gu
Daejeon
34129
South Korea
Phone: +82 42 860 1213
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Email: hjlee294@etri.re.kr
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