Connecting the Real World with the Virtual World: The SmartRFLib RFID-Supported Library System on Second Life

Introduction

The World Wide Web has been going through a constant revolution since its earlier days. Today it has become much more than just a platform for posting documents. It is “the” platform for global information sharing, communication, and collaboration across millions of users as well as for conducting business world-wide. The recent developments in social networking technologies on the web have also enabled people to form online communities and interact with each other in virtual environments at an unprecedented scale. On the other hand, the recent developments in sensor network technologies have enabled the wide-spread use of small, embedded sensing devices in various application domains in order to sense and react to real-world events in an automated fashion. Although these virtual and the real worlds still stay apart from each other to a large extent, we see an emerging trend towards these two worlds merging, enabling a seamless integration of the two to improve the interaction of people with each other as well as with the physical world that they live in. In this chapter, we provide an experience report on the SmartRFLib System that we have recently developed at ETH Zurich which takes an initial step in this direction.

SmartRFLib is an RFID-supported library system that builds on several modern technologies, two of which are the most relevant in terms of our focus in this chapter: Radio Frequency IDentification (RFID) and Second Life. RFID is used to identify book objects and users in a library, whereas Second Life is used to visualize important events in the library in a real-time fashion. The overall goals of this system are threefold:

• (i)

  to automate the functioning of a library by using RFID tags instead of relying on traditional paper labels or barcodes for manually identifying library books and users,

• (ii)

  to run higher-level event detection queries on RFID data streams, and

• (iii)

  to visualize important events and alerts in real time on a web-based interface that builds on Second Life.

Although we focused on a specific application scenario in his project, the system has been designed in a general-purpose way and can potentially be used for RFID data management and complex event detection for other application domains as well, such as supply-chain management.

In this chapter, we first provide a brief overview of the SmartRFLib System, describing its main architectural components and the communication between them. Then we explain in detail our experience with creating, controlling, and interacting with the virtual world that we built in Second Life, in order to model and monitor our system in a real-time fashion as it also interacts with the real world through RFID devices. Finally, we conclude the chapter by deriving some conclusions from our project experience as well as speculating about some future trends that we expect to see in this domain. Further details about our project can be found at our webpage (SmartRFLib Webpage), and our virtual library can be visited at the ETH Island in Second Life (Second Life Webpage).

Smartrflib System Overview

SmartRFLib has been designed as a general purpose RFID data management system. However, in order to be able demonstrate its functionality and features, we focused on building one particular application scenario: a library. In this section, we will first describe this application scenario, followed by an overview of our system.

The Library Application Setup

In our RFID-based library system, all books and library users are provided with passive RFID tags that can uniquely identify them. Additionally, three RFID readers are used, each with a well-assigned role. One reader was placed at the library exit and was used to keep track of the books and people leaving the library. A second reader was placed near a special checkout station and was used to keep track of book checkouts. Finally, a third reader was situated near the book shelves and was used for handling the inventory and automatic book check-ins. Figure 1 illustrates our library application setup (RFID readers are shown as red boxes).

Figure 1.

Library application setup