environment. In (Romer, 2003) the authors analyse
example use cases such as Smart Tool Box, Smart
Medicine Cabinet, Smart Agenda, RFID Chef and
Smart Playing Cards in order to extract generic
design concepts. They present two prototype
frameworks based on Jini and Web services. Tags
are attached to physical objects which hold pointers
to their virtual counterparts. The prototype
architecture uses RFID interfaces to periodically
scan the surroundings for tagged objects. When a
tagged object is detected, it is registered, mapped to
its virtual counterpart, its activity is logged and
associated executables are run based on the
application. Though there are several similarities,
both (Kerer) and (Romer, 2003) focus on a very
different usage model than the one proposed in this
paper, which is driven by explicit user actions.
The proposed approach in this paper is closely
aligned with (but independently explored from)
Elope as described in (Pering, 2005). Both
architectures investigate how RFID-enhanced
physical objects can be discovered and their
associated services launched through RFID-
enhanced mobile devices. One distinct difference is
that Elope focuses on a web-based service discovery
framework, whereas this paper integrates RFID
technology with the UPnP framework. Again, the
details of the data representation on the tag are not
discussed in (Pering, 2005).
In (Bettstetter, 2000) mobile devices act as the
mediator between the user and RFID-augmented
physical objects. The tags contain data that trigger
context events in the system (referred to as
CAPNET-based middleware). The primary focus of
(Bettstetter, 2000) is on usability tests, the users’
perception of visually marked RFID tags, the social
acceptance of a touch-based interaction model, and
the users’ feedback on security concerns and the
user interface. This paper places a stronger emphasis
on the design of the middleware architecture, the
technical realization through the UPnP technology
and the details of the data representation on the tag
for network connectivity and service discovery (an
aspect not addressed in (Bettstetter, 2000)).
Passive RFID tags and Bluetooth nodes are used
in (Siegemund, 2003) to augment everyday products
and objects. Bluetooth nodes are attached to RFID
scanners and they are used as mobile access points
allowing data stored on a passive tag (e.g. product
codes) to access the background infrastructure in
order to be semantically interpreted. The focus of
(Siegemund, 2003) is on logistics-driven use cases
such as Smart Product Monitoring, Smart Medicine
Cabinet and Remote Interaction with Smart Objects
and Locations. In contrast, this paper focuses on
consumer-driven services such network access,
printing, faxing, teleconferencing and so on.
In (Ravendy) the authors present a middleware
platform, referred to as MSDA, that manages the
dynamic composition of networks, integrates
existing middleware protocols (e.g. Jini, UPnP), and
provides a generic service to clients for performing
service discovery. MSDA-aware clients can connect
with services in different discovery domains through
ad-hoc networks, hotspots or Internet/Cellular
networks. The intended user interaction model is
different from the proposed method in this paper. In
(Ravendy) users can discover a new service by
reading an RFID tag but additional manual steps are
necessary. The user needs to initiate a search for an
available service in the network that can interpret
and process the description read from the RFID tag.
The type of RFID technology used and the tag data
representation are not discussed.
An RFID-enhanced framework for intelligent
products is presented in (Bajic). The key
technologies utilised are RFID and UPnP as in this
paper. The focus, though, is on logistics and
production processes and the RFID technology is
based on EPC standards. Objects are enhanced with
UPnP functionality. RFID sensing or direct UPnP
message exchange invokes the service discovery
process by providing the object ID. The example
case study is a warehouse management system.
In (Want, 1999) RFID tags of very small
capacity (a few bytes) are affixed to physical objects
containing a simple ID. The tag reader scans the
object ID, determines the current application context
and provides the appropriated feedback. The use
cases focus on how RFID-enhanced objects can be
used to present information on a wireless handheld
device. However, this approach does not enable
services to access data stored in mobile devices.
4 THE TOUCH PARADIGM
Users do not want to employ technology but rather
to interact with their environment. Even though
mobile phones have become a commodity, a major
part of mobile applications and services is hardly
used by today’s consumers. For example, basic
functions such as calling or text messaging are easy
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