Open W3C standard for IoT: Web of Things 1.1 specifications published

Oracle actively participates in more than 100 standards-setting organizations and more than 300 technical committees, with thousands of employees actively engaged in standards and open source projects. These employees contribute to efforts ranging from Java and Linux to Kubernetes and more, and you can find out more through Standards at Oracle. An example of our work in standards organizations where we drive and influence standards is the World Wide Web Consortium (W3C). W3C is the main international standards organization for the web, and the W3C Web of Things (WoT) specification family describes and supports the use of web technology for the internet of things (IoT). 

Aiding the Web of Things

After three years of collaboration amongst industry experts from Oracle, Siemens, Intel, Microsoft, Fujitsu, Hitachi, and others, the W3C Web of Things’ new architecture, thing description, and discovery specifications have been finalized and are now published as normative W3C recommendations. For details, read the press release.

These new W3C recommendations improve and expand the scope of the WoT and add significant new functionality. To that point, two supporting W3C notes have been updated: The Web of Things (WoT) binding templates and the Web of Things (WoT) scripting API. This international standards effort is important as part of the IoT and blockchain applications development at Oracle.

“The Web of Things set of specifications, including the updated version 1.1, serves as a unifying framework to address complex IoT use cases requiring interoperability across diverse ecosystems at massive scale,” says Jai Suri, vice president of IoT and Blockchain Applications Development at Oracle. “Oracle is pleased with the progression of this set of specifications to the Recommendation status and is proud to have been an active contributor, leader, and co-editor of this effort. We believe that this will benefit customers and users by enabling much-needed interoperability between different vendor solutions for IoT.”

What the Web of Things does

The goal of the WoT is to counter the fragmentation of the IoT and its tendency to form vertical silos. The W3C specifications have focused on gaps in existing standards, such as common formats for machine-readable metadata and other building blocks. They’re designed to support integration of IoT devices and services across multiple IoT platforms, standards ecosystems, and application domains. To avoid duplication of work done elsewhere, support for existing standards has been incorporated into the WoT specifications whenever possible. These documents address use cases and requirements from Web of Things (WoT): Use Cases and Requirements.

The new specifications are available from the following links:

• Architecture specification 
• Thing description
• Discovery

Other WoT building block specifications complement these specifications: WoT binding templates, WoT scripting API, WoT security and privacy guidelines, WoT Discovery, and WoT Profile.

Use Cases and Requirements

WoT specification requirements are driven by many use cases that have been contributed by domain experts from multiple application areas. In addition to the domain-specific “vertical” use cases, we have also considered several “horizontal” use cases that address technologies and usage patterns that appear in multiple domains. The first release of the W3C WoT Recommendations was published in Spring 2020. Since then, the WoT Working Group has collected many new use cases and requirements and has done work to address these. A special focus of recent work in the WoT Architecture Task Force has been out-of-the-box interoperability of network interfaces, with a focus on devices and services which are using (or are being bridged to) the HTTP(S) protocol.

A set of over 30 use cases was contributed by stakeholders from multiple industries for various application domains. These have been published in the WoT Use Cases and Requirements document: https://www.w3.org/TR/wot-usecases/.

Horizontal use cases that address multiple domains describe:

• Discovery
• Metadata Distribution
• Multi-Vendor System Integration
• Out of the Box Interoperability
• Digital Twin
• Cross Protocol Interworking
• Multimodal System Integration
• Multimodal Recognition, Synergistic Interactions
• Accessibility
• Virtual / Augmented Reality
• Edge Computing
• Low latency processing, always on scenarios

Domain-specific (vertical) use cases for a single application domain include:

• Greenhouse and Open-field agriculture
• Smart City
• Geolocation, Dashboard, Interactive Public Spaces, Smart Campus
• Smart Buildings, Energy Efficiency, Building Management
• Discrete and continuous manufacturing
• Retail
• Public and private health
• Energy distribution, smart grid
• Transportation
• Infrastructure, Cargo, People
• Automotive
• Smart Home
• Education

Architecture

The WoT Architecture document serves as an umbrella for all WoT specifications, and hence also defines the general goals of the W3C Web of Things. This document defines the abstract architecture of the WoT and delineates the design space for current and future building blocks, each of which are specified in separate documents. The purpose of the WoT Architecture document is to provide:

• definitions of terminology,
• definitions of the basic concepts and architectural constraints,
• an overview of the WoT building blocks and their interplay, and
• a guide for mapping the abstract WoT architecture onto a variety of concrete deployment scenarios.

It lays the foundation for the WoT building block specifications: Web of Things (WoT) Thing Description, Web of Things (WoT) Binding Templates, Web of Things (WoT) Scripting API, Web of Things (WoT) Security and Privacy Guidelines, Web of Things (WoT) Discovery, and Web of Things (WoT) Profile.

WoT architecture concepts are applicable to all levels of IoT applications: device, edge, and cloud. A common architecture fosters common interfaces and APIs across the different levels and enables inter-level integration patterns such as Thing-to-Thing, Thing-to-Gateway, Thing-to-Cloud, Gateway-to-Cloud, and even cloud federation, i.e., interconnecting cloud computing environments of two or more service providers for IoT applications.

Thing Description

A WoT Thing Description is a JSON document that describes an IoT device (Thing). It provides metadata and information about the network interfaces of Things that enables to interact with the device, i.e. to set or get properties, invoke actions, and subscribe to events. The Thing Description contains general metadata, domain-specific metadata, Interaction Affordances (which include the supported Protocol Bindings), and links to related Things.

WoT Thing Descriptions define a protocol-agnostic information model which can be augmented with semantic annotations to add context knowledge. The interaction affordances of that model can be bound to different protocols, and a single WoT Thing Description can contain bindings for several protocols. Thing Descriptions are typically encoded in a JSON format that also allows JSON-LD (semantic linked data) processing. The W3C WoT Thing Architecture and WoT Thing Description define a generic powerful description mechanism and a machine-readable format to describe very different devices, which may be connected over various protocols. 

Conclusion

The Web of Things provides a vendor-neutral way of describing IoT devices and interactions in a format that is readable by machines and understandable by humans. It enables the interworking of devices from multiple manufacturers and is expressive enough to build and interact with a structured network of devices. The newly released specifications are a solid basis for describing existing devices, defining digital twins and simulators, and integrating devices from multiple vendors in a common way.