Web of Things (WoT)
Web of Things is a set of standards concluded by the world wide web consortium (W3C), that encounters the interoperability, fragmentation and usability of the Internet of Things (IoT).
Web of Things does so, by collaborating with many standardized organizations, involving many stakeholders over many years for enabling building blocks in motive to compensate the foremost barrier of IoT, the interoperability and few more.
Colloquially, web of things is nothing but a network carrying information of physical devices through uniform resource identifiers (URI). The advent of WoT is to link the addresses for the purpose of easier inter-operability and fragmentation of IoT. IoT relies much on WoT, as a resource and service to operate.
Brief History
The idea of the Web as an application-layer for the IoT started to emerge in 2007. Dominique Guinard and Vlad Trifa started the Web of Things online community and published the first WoT manifesto, advocating the use of Web standards (REST, Lightweight semantics, etc.) to build the application layer of the IoT.
In 2011, two of the first PhD theses on the Web of Things were presented at ETH Zurich: Building Blocks for a Participatory Web of Things: Devices, Infrastructures, and Programming Frameworks and A Web of Things Application Architecture – Integrating the Real-World into the Web.
What WoT encloses?
Web of Things (WoT) comes possible through an Interest Group and Working Group, who are responsible for setting standards for the need and bringing accessible, the features of WoT standards. In February 2017, the Working group has started working on 4 deliverables namely:
- Web of Things (WoT) Thing Description – provides a machine-readable data format for describing the metadata and network-facing interfaces of Things. It is based upon the fundamental concepts introduced in this document, such as interaction affordances.
- Web of Things (WoT) Binding Templates – provides informational guidelines on how to define network-facing interfaces in Things for particular protocols and IoT ecosystems, which we call Protocol Bindings. The document also provides examples for a number of existing IoT ecosystems and standards.
- Web of Things (WoT) Scripting API – which is optional, enables the implementation of the application logic of a Thing using a common JavaScript API similar to the Web browser APIs. This simplifies IoT application development and enables portability across vendors and devices.
- Web of Things (WoT) Security & Privacy Guidelines – represent a cross-cutting building block. This informational document provides guidelines for the secure implementation and configuration of Things, and discusses issues which should be considered in any systems implementing W3C WoT.
WoT Architecture – How WoT upholds IoT?
Providing specific identity to Things
WoT architecture explains the functioning of the web of things. According to WoT Architecture, a thing is the abstraction of a physical or virtual entity and is described by a WoT Thing Description (TD). TD allots specific address to every Thing, aimed to connect via internet. A TD is instance-specific and is the default external, textual (web) representation of a Thing.
Thing Description enables the user interface smooth, by letting know the consumers of all the kind of capabilities that the Thing can expel. TD also comes as machine-understandable representation format. Hence WoT Thing Description is the connecting link between the consumer & things.
Also, the Thing is interlinked to the web, able to interpret and process the details of its related resources. For example, an IoT enabled fan would allow its users to have control over it and it would also provide the manuals, catalogs and its spare-part information. For this, the thing is also inter-coupled with other things in the internet. This inter-linkage explains the web-of-things. Similarly, the Thing can also be maneuvered, interpreted by means of an intermediary.
Intermediaries can act as proxies for Things, where the Intermediary has a WoT Thing Description similar to the original Thing, but which points to the WoT Interface provided by the Intermediary. Intermediaries may also augment existing Things with additional capabilities or compose a new Thing out of multiple available Things, thereby forming a virtual entity. To Consumers, Intermediaries look like Things, as they possess WoT Thing Descriptions and provide a WoT Interface, and hence might be indistinguishable from Things in a layered system architecture like the Web. An identifier in the WoT Thing Description must allow for the correlation of multiple TDs representing the same original Thing or ultimately unique physical entity.
This ensures of the fact that web-of-things (WoT) architecture provides the base of operating of Internet of Things (IoT), by enabling Thing-to-Thing, Consumer-to-Thing, Thing-to-Gateway, Thing-to-Cloud, Gateway-to-Cloud linkages and even cloud federation, i.e., interconnecting cloud computing environments of two or more service providers for IoT applications.
Why to go for Intermediaries?
Well you may ask, why to have gateways or cloud as intermediary, when the things can directly be connected to the internet.
Advent of intermediary, resolves an IoT obstacle, which restraints the addresses that could be connected to internet, owing to its IPv4’s (Internet Protocol version 4) capacity of 4.3 billion IP addresses. That is, as per the standards of IPv4, it can hold only 4.3 billion IP addresses.
Consider, if one house-hold includes at-least five lights, four fans, and one air-conditioner as IoT-powered devices, it sums up to 10 IoT devices and say if 1 billion houses in the world exists, IoT needs 10 billion IP addresses, in addition to the already existing 588 million reserved addresses.
However, connecting through an intermediate may help to bring down the number, as each single gateway household can have only one address.
WoT also enhances the inter-operability of IoT devices, which has been a biggest headache for IoT technology.
Understanding better through a Smart Home:
Smart home implies of making the home smart or autonomous, by sensing, analyzing and interpreting the happenings inside the home. For instance, light, air-conditioners and fans automatically turning off based on room occupancy, window blinds auto-closing off by inspecting the weather conditions and presence. This feature also aids in optimizing the energy and security surveillance.
In a smart home, the edge devices like sensors in IoT devices, home appliances, cameras may have a local communication protocols like ECHONET, ZigBee, KNX to be connected to a gateway. Each home can have multiple gateways and multiple local protocol can be linked to a gateway. Gateways are connected to the cloud via internet, while devices also have ability to be linked with cloud directly.
The Edge devices, sensors analyze the data and transfer to the cloud, examines it or validates the data and provide the value to users through edge devices by means of a clean user-interface controlling methods. Smart home provides benefits such as voice control and home automation.
Epilogue
Internet of Things (IoT) is an emerging technology that aids and makes possible other enhancements of the world-kind, namely industrial revolution 4.0, automation and many more. However, the technology is not deployed all over the world due to its operating barriers like inter-operability, privacy and security criteria.
Through this web of things, the scenario eases the IoT, helping it to resolve its barriers. Hope, we all would have smart homes in future!
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