Introduction to the Web of Things

The Internet of Things (IoT) has evolved with various and sometimes exclusive designs, making it challenging to connect different devices. This can also result in vendor lock-in, where users are limited to a particular company's products due to lack of compatibility with other products. The Web of Things aims to resolve these issues by standardizing the IoT.

What is the Web of Things?

The concept of the Web of Things was first introduced by researchers around 2007. It has since been adopted and promoted by organizations like Mozilla, Siemens, and the World Wide Web Consortium (W3C). These organizations have established interest groups to define the standards that should govern the Web of Things. This includes the Web Thing Model, which represents a standardized way to provide information on a virtual or physical device, known as a Thing.

"While IoT and Web of Things both essentially serve the same purpose of connecting smart devices over the Internet, there are some key differences to keep in mind."

-Mobidev

Along with the Web Thing Model, the groups involved in developing the Web of Things have also introduced several other standards. These include the WoT Architecture, WoT Thing Description, WoT Scripting API, and WoT Binding Templates. Each of these makes up the core components of the Web of Things design.

IoT vs WoT

While the Internet of Things and Web of Things essentially serve the same purpose of connecting smart devices over the Internet, there are some critical differences between them. These differences are defined by the purpose each one serves and the implementations they involve.

The main difference between IoT and WoT is the layer at which each establishes interconnectivity between devices. In this case, IoT solves just the network layer between devices. That is, each device has a transport medium over which to communicate. To use the example of a highway, IoT represents the road on which cars travel from place to place. It is purely the transportation medium for information to travel from point to point. It is not concerned with how data travels over it or what it intends to do when it reaches its destination. Because of this, IoT itself cannot help guide information to its destination or coordinate between different data sources. This is where IoT's limitations begin to become apparent.

In contrast to IoT's network layer solutions, WoT can be thought of as the application layer. It sits on top of IoT conceptually and functionally. WoT is not an alternative or competitor to IoT; instead, it tries to enhance IoT. It does this by defining standard definitions and models for representing devices on the Internet. In the highway analogy, WoT represents the street signs, traffic lights, and engineered routes that establish the rules of the road. It exists to establish well-defined paths for data to travel between points and ensure that it is compatible with its source and destination.

WoT enables devices to connect over the web using mainstream technologies and standards from a technical perspective—for example, HTML 5.0 and Javascript. The WoT paradigms promote RESTful API designs, a common Internet standard for application development.

In summary, WoT evolves IoT from a pure concept to a fully-developed architectural approach for smart device interaction. It serves to define standards for IoT-enabled devices to communicate better.

WoT Architecture

The World Wide Web is composed of many different evolving architectural standards. The Web of Things architecture has been contributed to by many organizations, but it is spearheaded by the W3C, a group that establishes web standards. The W3C's standardization of WoT is based on several building blocks. These are the Thing Description, Binding Templates, Scripting API, and Security and Privacy Guidelines.

The WoT Thing Description is the basis upon which IoT devices ("Things") can fit into WoT. The Thing Description defines the metadata and interfaces that a Thing should provide. This definition produces a format for metadata that is guaranteed to be machine-readable in compliance with the standard.

Protocol Bindings refer to the protocols over which IoT devices communicate. The W3C attempts to establish, therefore, the standard interfaces to interact with these protocols with Binding Templates. These Binding Templates allow unique Thing Descriptions to be modeled after and interact with different established protocols for communication.

The WoT Scripting API provides a common programming language for implementing Thing connectivity over IoT. This API is in the form of a JSON API. A device doesn't need to use the Scripting API to be part of the WoT, but it is convenient to simplify application portability across platforms.

Finally, the Security and Privacy Guidelines are perhaps the most important aspect of WoT. Much like the Internet itself does not define any specific safety guidelines for applications, neither does the Internet of Things. In a technical world where cyber-attacks and compromised personal electronic security are becoming a threat, ensuring that data is safe is more important than ever.

This becomes especially true when physical devices are connected to the Internet. These devices can be directly connected to homes, offices, or even medical applications. This is why W3C has laid out the Security and Privacy Guidelines for developers to implement standard safety practices in Internet-connected devices.

While the WoT architecture is very detailed, it is founded on these basic concepts. These four components comprise the basic layout of WoT.

WoT Use Cases and Applications

With the prevalent adoption of IoT already in use, one may wonder if there are any practical reasons for this newer application layer in the real world. There are, in fact, many use cases for WoT standards in commercial, residential, and industrial capacities.

Many people will interact with WoT through smart home technologies. A smart home is inherently dependent on many different devices communicating, either directly or through the cloud. Thermostats, doors, security cameras, and even smoke detectors need to be reachable by homeowners. WoT ensures that these devices all speak the "same language" when working together.

In a commercial application, many of the exact needs still apply. WoT-enabled production facilities, smart factories can take advantage of machinery connected to the Internet. This allows automated production capabilities and remote monitoring of that production. That monitoring can also ensure the safety of factory conditions, much like the security cameras and smoke detectors that help keep families safe at home.

The possibilities of a standardized Internet of connected Things are endless. Agriculture, logistics, construction, transportation, and municipalities can all benefit from the advancements of smart device technology. These industries often overlap, so the interconnectivity of their devices with other businesses is essential to the smooth operation of the supply chain. WoT ensures that devices can communicate not just within one use case but also across use cases seamlessly.

WoT Challenges

While WoT seeks to solve many IoT problems, it does come with its challenges. No technology is perfect, and there are, of course, tradeoffs to certain gains. WoT is no exception to this.

The main concern with WoT is security and privacy. As mentioned above, putting anything onto the Internet risks losing due to web application vulnerabilities. That risk is even more serious when there is a direct physical link to the real world. The W3C's Security and Privacy Guidelines outline best practices for mitigating these risks. However, those guidelines are public, which poses the possibility that hackers could find loopholes in them. Also, when many devices follow the same standard, any weakness in that standard exposes every device to the same vulnerability.

Besides security, WoT devices could suffer from energy inefficiency. A home or business that is fully connected to WoT will require many devices to be using electricity 24/7. This round-the-clock operation is essential so that the device can activate at any time it is needed. Of course, this can be mitigated by identifying peak times when devices need to be active. But for certain use cases, such as security and safety systems.

That need for constant availability is also a potential vector for failure. Denial-of-service (DoS) attacks can render devices inoperable, even if they are powered on all the time. In a DoS attack, hackers continuously send signals to a device to occupy its resources so that legitimate requests cannot be processed. The attack can lock valid users out of their own devices or even crash the devices for as long as the attackers have the resources to continue sending requests.

The good news about WoT is that, as an open standard, it is always being innovated by the most active technical contributors who specialize in these areas. Because of that, security concerns and drawbacks can be solved over time as the standards improve. Even today, many of these risks are only minor, thanks to the hard work that has already been put in to set up the security guidelines of WoT.

The Future of WoT

The IoT has been a revolutionary shift in the perception of the types of devices that connect to the Internet. It is no longer assumed that only computers can communicate over the web. Now, all types of devices, appliances, and tools can be programmed with the ability to improve their usability thanks to the Internet. This pervasive paradigm shift has evolved even further with the development of the Web of Things.

As the growing capabilities of smart devices led to growing adoption, the need for standardized communication between devices grew as well. This growth shows no signs of slowing, as more and more devices are getting online every day. That's where WoT has stepped in to help guide the changing landscape of smart devices to converge on common protocols for interconnectivity.

You may have heard of the most recent protocol meant to help simplify the connection between different smart home devices: Matter. This standardization will help WoT grow one of the more common trends in web technology.

As the WoT architecture gains adoption among device developers, the capabilities of these devices will increase. Devices will no longer be locked into their vendors, driving competition and innovation between producers. This alone will allow the trends of smart homes, businesses, factories, and cities to continue at an efficient and affordable rate.

Originally published on December 16, 2021. Updated on January 19, 2023.