Dominique Guinard

Interacting with the SOA-Based Internet of Things: Discovery, Query, Selection, and On-Demand Provisioning of Web Services

The increasing usage of smart embedded devices in business blurs the line between the virtual and real worlds. This creates new opportunities to build applications that better integrate real-time state of the physical world, and hence, provides enterprise services that are highly dynamic, more diverse, and efficient. Service-Oriented Architecture (SOA) approaches traditionally used to couple functionality of heavyweight corporate IT systems, are becoming applicable to embedded real-world devices, i.e., objects of the physical world that feature embedded processing and communication. In such infrastructures, composed of large numbers of networked, resource-limited devices, the discovery of services and on-demand provisioning of missing functionality is a significant challenge. We propose a process and a suitable system architecture that enables developers and business process designers to dynamically query, select, and use running instances of real-world services (i.e., services running on physical devices) or even deploy new ones on-demand, all in the context of composite, real-world business applications.

A resource oriented architecture for the Web of Things

Many efforts are centered around creating large-scale networks of “smart things” found in the physical world (e.g., wireless sensor and actuator networks, embedded devices, tagged objects). Rather than exposing real-world data and functionality through proprietary and tightly-coupled systems, we propose to make them an integral part of the Web. As a result, smart things become easier to build upon. Popular Web languages (e.g., HTML, Python, JavaScript, PHP) can be used to easily build applications involving smart things and users can leverage well-known Web mechanisms (e.g., browsing, searching, bookmarking, caching, linking) to interact and share these devices. In this paper, we begin by describing the Web of Things architecture and best-practices based on the RESTful principles that have already contributed to the popular success, scalability, and modularity of the traditional Web. We then discuss several prototypes designed in accordance with these principles to connect environmental sensor nodes and an energy monitoring system to the World Wide Web. We finally show how Web-enabled smart things can be used in lightweight ad-hoc applications called “physical mashups”.

From the Internet of Things to the Web of Things: Resource-oriented Architecture and Best Practices

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.

Towards physical mashups in the Web of Things

Wireless Sensor Networks (WSNs) have promising industrial applications, since they reduce the gap between traditional enterprise systems and the real world. However, every particular application requires complex integration work, and therefore technical expertise, effort and time which prevents users from creating small tactical, ad-hoc applications using sensor networks. Following the success of Web 2.0 “mashups”, we propose a similar lightweight approach for combining enterprise services (e.g. ERPs) with WSNs. Specifically, we discuss the traditional integration solutions, propose and implement an alternative architecture where sensor nodes are accessible according to the REST principles. With this approach, the nodes become part of a “Web of Things” and interacting with them as well as composing their services with existing ones, becomes almost as easy as browsing the web.

Sharing using social networks in a composable Web of Things

In the emerging “Web of Things”, digitally augmented everyday objects are seamlessly integrated to the Web by reusing Web patterns such as REST. This results in an ecosystem of real-world devices that can be reused and recombined to create new ad-hoc applications. This, however, implies that devices are available to the world. In this paper, we propose a platform that enables people to share their Web-enabled devices so that others can use them. We illustrate how to rely on existing social networks and their open APIs (e.g. OpenSocial) to enable owners to leverage the social structures in place for sharing smart things with others. We finally discuss some of the challenges we identified towards a composable Web of Things.

Embedding internet technology for home automation

As more and more digital appliances populate our homes, networking them to form a home automation (HA) system not only becomes an option, but almost a necessity. While comfort, security, and energy efficiency can be provided by many existing systems, they all remain complex islands that are difficult to expand and customize. We propose Internet technology to remedy the situation and to become the future solution for HA. For this, we analyze the feasibility of todays Internet technology with regard to traditional HA solutions. Furthermore, we present two case studies that substantiate the benefits of our proposal. As we will show, with IPv6 and 6LoWPAN, a single network serves the classical as well as emerging aspects of HA while concepts from the Web provide benefits for both, developers and users.

Supporting device discovery and spontaneous interaction with spatial references

The RELATE interaction model is designed to support spontaneous interaction of mobile users with devices and services in their environment. The model is based on spatial references that capture the spatial relationship of a user’s device with other co-located devices. Spatial references are obtained by relative position sensing and integrated in the mobile user interface to spatially visualize the arrangement of discovered devices, and to provide direct access for interaction across devices. In this paper we discuss two prototype systems demonstrating the utility of the model in collaborative and mobile settings, and present a study on usability of spatial list and map representations for device selection.

A mobile product recommendation system interacting with tagged products

This paper presents a concept that enables consumers to access and share product recommendations using their mobile phone. Based on a review of current product recommendation mechanisms it devises a concept called APriori. APriori leverages the potential of auto-ID-enabled mobile phones (barcode/RFID) to receive and submit product ratings. Since mobile users cannot be expected to have the patience and time to compose text-based reviews on mobile phones, we introduce a new rating concept that allows users to generate new rating criteria. The concept is tailored to the limited attention and input options of mobile users in real-world environment. This work describes the architecture, implementation, and evaluation of APriori. For an evaluation we have taken the approach of interviewing 26 users in the frames of a formative user study, with the goal to further improve the system for an application in the real world. In addition, the paper discusses open issues regarding community-based product recommendations on mobile phones and proposes solutions.

An extensible discovery service for smart things

We present DiscoWoT, a semantic discovery service for Web-enabled smart things. The service is based on the application of multiple Discovery Strategies to a Web resources representation, where arbitrary users can create and update strategies at runtime using DiscoWoTs RESTful interface. Its goal is to provide a future-proof mechanism for enabling both, human users and machines, to semantically discover functionality provided by Web-enabled devices. Ultimately, it aims to allow for the facilitated discovery, selection, and utilization of smart things. DiscoWoT incorporates a transparent mechanism for deferring resource discovery to external handlers and can thus interact with other services within discovery service federations. It may be accessed by arbitrary users for ad hoc discovery of functionality offered by Web resources or incorporated into infrastructures for Web-enabled smart things.

Searching in a web-based infrastructure for smart things

Given the expected high number of accessible digitally augmented devices and their communication requirements, this paper presents our work on creating a Web-based infrastructure for smart things to facilitate the integration, look-up, and interaction with such devices for human users and machines. To exploit the locality of interactions with and between smart things, the proposed infrastructure treats the location of a smart thing as its main property and is therefore structured hierarchically according to logical place identifiers. We discuss the infrastructures look-up mechanism that leverages Web patterns to foster scalability and load balancing and features an advanced caching mechanism that greatly reduces the response time and number of exchanged messages. These properties are demonstrated in an evaluation in a simulated smart environment.