5 From the Internet of Things to the Web of Things: Resource Oriented Architecture and Best Practices1

Creating networks of “smart things” found in the physical world (e.g., with RFID, wireless sensor and actuator networks, embedded devices) on a large scale has become the goal of a variety of recent research activities. Rather than exposing real-world data and functionality through vertical system designs, we propose to make them an integral part of the Web. As a result, smart things become easier to build upon. In such an architecture, popular Web technologies (e.g., HTML, JavaScript, Ajax, PHP, Ruby) can be used to build applications involving smart things, and users can leverage well-known Web mechanisms (e.g., browsing, searching, bookmarking, caching, linking) to interact with and share these devices. In this chapter, we describe the Web of Things (WoT) architecture and best practices based on the RESTful principles that have already contributed to the popular success, scalability, and evolvability of the Web. We discuss several prototypes using these principles, which connect environmental sensor nodes, energy monitoring systems, and RFID-tagged objects to the Web. We also show how Web-enabled smart things can be used in lightweight ad-hoc applications, called “physical Mashups”, and discuss some of the remaining challenges towards the global World Wide Web of Things. 5.1 From the Internet of Things to the Web of Things As more and more devices are getting connected to the Internet, the next logical step is to use the World Wide Web and its associated technologies as a platform for smart things (i.e., sensor and actuator networks, embedded devices, electronic appliances and digitally enhanced everyday objects). Several years ago, in the 1 The original publication is available at www.springerlink.com published in the book: “Architecting the Internet of Things”, edited by M. Harrison, F. Michahelles and D. Uck-