TAGLINK: AN EVOLUTIONARY APPROACH TOWARDS

ADVANCED MOBILE TAGGING APPLICATIONS

Jan Buck, Frederic Majer, Matthias Schmitt, Patrick Freudenstein and Martin Nussbaumer

Institute of Telematics, University of Karlsruhe (TH), Engesserstr. 4, 76128 Karlsruhe, Germany

Keywords: Mobile tagging, object hyperlinking, automatic identification and data capture.

Abstract: Within the last years camera phones have been established as an everyday appliance. Along with the advent

of these appliances so called “mobile tagging applications”, arose. Physical objects are tagged with a visual

code containing the URI of a resource. Camera phones are used to capture these visual codes and to access

content related to physical objects. In most current mobile tagging applications the evolution of content

associated with physical objects is not considered. Thus a later change and adding of resources is not

supported. Taking these problems into account we present a novel framework for the development and

evolution of advanced mobile tagging applications, called TagLink.

1 INTRODUCTION

By the end of 2007 more than one billion camera

phones will be in use. While in 2006 40% of US

mobile phone users had a camera phone, in 2007

already 60% possessed a mobile phone with this

functionality (Meyers 2007). Along with the

establishment of camera phones as an everyday

appliance, a new trend, „mobile tagging“ arose. A

tag containing a barcode that encodes the URI of a

resource is put up at physical objects. Camera

phones are used to capture these barcodes and

subsequently software running on the phone decodes

them. Mobile web user agents can be used to display

content linked from barcodes.

Although endeavours to link real world objects

and the information space have already been made

before the current mobile tagging trend, all these

approaches couldn’t involve the public in a similar

way due to the limited distribution of appropriate

appliances. Nevertheless many of the developed

systems, known as Automatic Identification and

Data Capture (AIDC) systems (Smith 2002), realise

advanced functionalities not considered in current

mobile tagging solutions. An important drawback of

current applications is the linking from a physical

object to a resource by hard encoding the URI of the

resource in a tag. The change of a resource demands

republishing all tags linking to that resource. This is

even aggravating in 1-n or n-n relations between

resources and tags. Furthermore only the assignment

of a single resource per barcode is allowed.

Taking these problems into account, we

introduce a framework for the development and

evolution of advanced mobile tagging systems.

Section 2 outlines a scenario revealing the

unexploited opportunities of current approaches. In

section 3 the TagLink approach is presented. In

section 4, we give a brief overview of related

approaches and conclude with a summary and an

outline of planned future work in section 5.

2 THE PROBLEM DOMAIN

In the following, a scenario for the employment of

mobile tagging systems is described and

requirements of a platform supporting this scenario

are derived.

In a generic scenario tools can be used to

produce tags that contain links to resources. These

tags are attached to physical objects. Individuals can

use camera phones to capture barcodes and navigate

to the resources encoded in them using a web

browser. This approach is appropriate in scenarios

where objects shall be tagged only short-term and

resources are not underlying change. In scenarios

where information associated with physical objects

evolves and users collaborate in the evolution of the

information space this approach falls short.

321

Buck J., Majer F., Schmitt M., Freudenstein P. and Nussbaumer M. (2008).

TAGLINK: AN EVOLUTIONARY APPROACH TOWARDS ADVANCED MOBILE TAGGING APPLICATIONS.

In Proceedings of the Fourth International Conference on Web Information Systems and Technologies, pages 321-324

DOI: 10.5220/0001528803210324

 SciTePress

The problems revealed by this simple scenario

can be avoided by introducing a mediator that links

tags to resources. That way the assignment of

resources to barcodes can change and additional

resources can be assigned. Such additional

assignments comprise advanced interactions on

resources like adding reviews or comments by end-

users. Thus the quality of the provided information

can be enhanced. Given this architecture dedicated

scenarios become possible.

2.1 The Library Scenario

A library could offer a service that provides

additional information on books by acting as a

mediator between ISBN-13 (International ISBN

Agency. 2005) barcodes attached to book covers and

electronic resources. These barcodes encode the

International Standard Book Number (ISBN) of a

book. Client applications decode this information

and request additional resources on books from a so

called resolver service.

Figure 1: Library scenario.

In the following we will describe a possible

sequence. As depicted in Figure 1 a library visitor

uses his camera phone to capture a barcode attached

to a shelf in the library that contains the URI of the

library’s resolver service (1). The visitor uses a

mobile application to request the resolver service (2)

and retrieves information concerning the library.

Subsequently the visitor can capture ISBN-13

barcodes printed on book covers (3) and request the

library resolver service for resources associated with

the ISBN encoded in the barcode (4). Using web

browsers or special mobile applications these

resources can be accessed (5).

The types of resources provided by the library

can vary from information about the author, the

book, the availability of the book, other books of the

same author or related books and their location in

the library. Moreover users can enlarge the provided

information by providing additional resources. They

can write reviews for books or comment content and

thus enhances the quality of information.

Furthermore one could imagine that visitors are able

to perform “actions” on books (6). For example it

would be possible that a library visitor just walks

through the library and scans the barcodes of books

he wants to lend and at the end of his visit picks up

all selected books at the lending. Another

imaginable service provided by the library would be

the sale of books in cooperation with publishing

companies.

2.2 Requirements

In the following we will present basic requirements

of a framework supporting the development and

evolution of advanced mobile tagging applications.

Description: A central requirement is the ability to

describe real world objects in a simple and

extensible manner. Additionally bidirectional

relations between these objects and virtual resources

have to be allowed.

User Involvement: By involving users in the

creation of virtual counterparts to physical objects

and the distribution of barcodes linking to them, a

rapid growing of interconnections between the real

world and the information space can be achieved.

Moreover users can review and comment the

helpfulness and correctness of the provided data.

Mobility: Special conditions of mobile applications

have to be considered. If no connection to electronic

resources can be established or the mobile appliance

is unsuitable for the processing of a resource, the

system must support collecting and later processing

of resources.

Standard Orientation: Applications should base on

existing web standards. That way interoperability

with existing web applications is ensured and

isolation from technical trends is prevented.

3 THE TAGLINK FRAMEWORK

In the following section we present the TagLink

framework, a framework supporting the

development and evolution of mobile tagging

solutions.

3.1 Overview

In contrast to most current mobile tagging

approaches we propose an indirection between

physical barcodes and electronic resources. As

depicted in Figure 2 a barcode can be associated

with multiple topics, which can be considered as

WEBIST 2008 - International Conference on Web Information Systems and Technologies

322

containers for content. Likewise topics can be

associated with multiple barcodes.

Barcode Topic Content

Figure 2: Indirection between Barcode and Content.

By allowing multiple associations of topics to

barcodes, topics serve as items of reuse that can

evolve independently over time. To support this

approach the TagLink-framework provides a

resolver service that acts as a mediator between

barcodes and resources.

Figure 3: Overall architecture of an application developed

with the TagLink framework.

The overall architecture of an application build on

the TagLink-framework is depicted in Figure 3. The

identifier of a barcode combined with the URI of the

according resolver service is encoded in a barcode.

Users capture barcodes using camera phones.

Mobile applications decode the included

information, communicate with the resolver service

and retrieve resources related to barcodes. Common

resources are electronic documents and Web

Services. But resources especially tailored to the

needs of a dedicated application are possible also.

To achieve a maximum of flexibility and

extensibility concerning different types of resources

used in mobile applications, resources are defined in

RDF notation (Klyne G. and Carroll J. J. 2004) and

are managed in a triple store. Thereby multiple

applications can operate on a single triple store

whereby synergy effects concerning the tagging of

real world objects can be utilized. In Figure 4 an

exemplarily RDF graph for the library scenario is

depicted.

lib :A Tag

lib :ADoc

lib:AuthorX

„J.B“^xsd:string

tag :topic

tag:digitalDoc

tag:creator

lib:AnotherTag

tag:topic

Figure 4: Example of a RDF graph.

The semantic model of an application can be

accessed using mobile clients as well as an

Administration Web Application by communicating

with the resolver service. In the following the

technical framework will be presented in detail.

3.2 Resolver Service

The resolver service is the core component of the

TagLink architecture. It is a Web Service providing

access to resources associated with barcodes.

Existing triple stores can be used to store and

manage RDF resources. The built-in reasoning

support of triple stores can be applied to filter

relevant resources on the server-side and thus to

minimize client-side computation. Moreover the

resolver service offers interfaces for the

management of resources and provides functionality

to create barcodes that can be printed and attached to

physical objects.

3.3 SmartTag Mobile Application

On the client side the TagLink framework consists

of an extensible client application, called SmartTag

that allows users to perform operations on the

application model managed by the resolver service.

A plug-in mechanism allows the extension of the

SmartTag application with forms, tailored to special

resource. When starting the program all registered

plug-ins are loaded and the user is presented an

overview of all possible operations. To meet the

special conditions of mobile applications the

SmartTag application comprises a bookmark store.

Thus resources can be copied to the bookmark store

and processed later.

3.4 Administration Web Application

Beside the SmartTag mobile application the

TagLink framework comprises an Administration

Web Application that can be used by administrators

and content providers to manage resources.

Furthermore the Administration Web Application

TAGLINK: AN EVOLUTIONARY APPROACH TOWARDS ADVANCED MOBILE TAGGING APPLICATIONS

323

can be used to process resources stored in the

bookmark store of the SmartTag application.

4 RELATED WORK

In the following existing approaches using AIDC

methods to connect physical objects with the

information space will be described briefly.

WebStickers is introduced in (Ljungstrand 2000)

and deals with the idea to use tagged physical

objects as bookmarks for websites. Thereby the

physical surrounding is regarded as an extended

workspace. Although many of the presented

requirements were met, the approach lacks regarding

extensibility as it focuses only bookmarks.

Furthermore expensive barcode scanners are

required, what increases the price of the system.

A very comprehensive approach is the

CoolTown (Kindberg 2000) project. Due to the age

of the project modern appliances like camera phones

have not been considered. The goal of the project

was to provide an infrastructure for nomadic

computing. The project builds on web technologies

and parts of the approach were considered in the

TagLink approach. However the evolution and reuse

of content is not considered.

Another examined approach is the ETHOC

(short for “EveryThing Has Online Content”)

project, described in (Rohs 2003; Rohs 2004). The

project covers the creation, administration and

mediation of virtual counterparts of real world

objects. Physical objects are tagged with barcodes

encoding an identifier. The creation and

modification of content is restricted to a web

interface only and allows no support by the client

application itself. Thus focussing stronger

involvement of end-users is hindered.

5 CONCLUSIONS

In this paper we presented a novel approach for the

development and evolution of advanced mobile

tagging applications. Derived from an exemplary

scenario, requirements of such a framework were

presented. Taking these requirements into account

the TagLink framework supporting the development

and evolution of mobile tagging applications was

introduced. In the future we will focus our research

on the development of an ontology for mobile

tagging applications. Moreover we will evaluate the

framework using alternative identification

technologies like Radio Frequency Identification

(RFID) (Molnar 2004).

REFERENCES

International ISBN Agency., 2005. The International

Standard Book Number System: ISBN Users's Manual.

Kindberg, T., et al., 2000. Towards a real-world wide web.

9th workshop on ACM SIGOPS European workshop:

beyond the PC: new challenges for the operating

system Kolding, Denmark ACM.

Klyne G. and Carroll J. J., 2004.). "Resource Description

Framework (RDF): Concepts and Abstract Syntax."

Retrieved 05.11.2004, from http://www.w3.org/

TR/2004/REC-rdf-concepts-20040210/.

Ljungstrand, P., et al., 2000. WebStickers: Using Physical

Tokens to Access, Manage and Share Bookmarks to

the Web. DARE 2000 on Designing augmented reality

environments. Elsinore, Denmark ACM.

Meyers, J., 2007. Camera Phones and Social Networking-

A New Global Focus, In-Stat.

Molnar, D., Wagner, D., 2004. Privacy and security in

library RFID: issues, practices, and architectures.

11th ACM conference on Computer and

communications security Washington DC, USA,

ACM.

Rohs, M., et al, 2004. "Using Camera-Equipped Mobile

Phones for Interacting with Real-World Objects."

Rohs, M., Jürgen Bohn, 2003. Entry Points into a Smart

Campus Environment " Overview of the ETHOC

System. 23rd International Conference on Distributed

Computing Systems, IEEE Computer Society.

Smith, A. D., Offodile, F., 2002. "Information

management of automated data capture: an overview

of technical developments." Information Management

and Computer Security 10(3): 109-118.

WEBIST 2008 - International Conference on Web Information Systems and Technologies

324