The Design Principles and Practices of Interoperable Smart Spaces - Advanced Design Approaches to Emerging Software Systems - page 20

information overload, the environments are to be
made to be smart.
The motivations for smart environments are
quite well understood: to increase the visibility of
opportunities, to support context understanding
and ultimately to provide the correct informa-
tion when and where it is required, even if not
explicitly requested, with its content and format
optimally adapted to the user situation and profile
(Weiser 1993). Although smart spaces have been
an interest of researchers and industrial profes-
sionals for years, there is hardly any easy working
smart environment in practice. The main obstacle
is the lack of the interoperability of devices and
systems that provide the execution environment
for ambient applications. Although the interoper-
ability could be achieved at the device level by
handling communication, connectivity and data
with a set of standard protocols, selected for use
in a situation based manner by using, e.g., the
reflection pattern (Buschmann et al. 1996), there
are still obstacles to handling the interoperability
with higher system architecture levels, the service
and information levels. Service interoperability
concentrates on unambiguously describing service
semantics, so that services can be searched and
they can interact with each other (Kantarovitch
& Niemelä 2008). Enhanced functionality is
achieved through service discovery, matchmak-
ing and the merged functionality of a selected
set of services. Moreover, services enriched with
semantic information on context and resources
could provide the service that is the most suitable
for the user's preferences and the situation at hand
(Soylu et al. 2009). These enrichments however
have costs; they make service centric systems
more complex and error prone, and increase the
need of computing resources.
Recently, two promising approaches for
context-awareness have been proposed; a spatial
application programming model (Meier, et al
2008) and an approach that is based on Model
and Ontology Driven Development (Soylu et al.
2009). The spatial application programming model

uses a small set of predefined types for composing
information and context. The approach has some
similarity with ours, but it relies on a specific
programming model, not a model driven develop-
ment approach that embodies a generic ontology
used for information sharing. Soylu et al. (2009)
link the model driven development with ontology
engineering and aim to assist context-awareness
in all phases of the application development life
cycle, i.e. at design time and run-time. Their special
focus is on the context-awareness of the digital
world, where the use of abstract models is easier
and efficient. However, the approach introduced
is at a conceptual level and still requires long and
short term research. Our goal, on the contrary, is
to adopt the semantic web technologies to physi-
cal spaces and to make the existing entities of our
environments both smart and adaptive.
Our approach facilitates interoperability at the
information level and lets devices and systems use
existing solutions for describing, managing and
executing services to facilitate the functionality
which is required from a smart space (Sofia 2010).
Thus, ambience is based on information which is
provided by sensors embedded into environments
and existing services, running on heterogeneous
devices and systems, for free use in smart space
applications, which also share the semantics of
information. Thus, smart space interoperability
is based on information sharing and the adapta-
tion to existing (legacy) devices and systems.
We exploit ontology orientation to represent the
semantics of information. This information is
shared and mapped onto a graph that uses a triple
(two nodes - subject and object - connected by a
predicate) as an information elementary element.
Native information from the legacy devices and
services is captured by agents that translate it
into the specified information format of the smart
spaces. Thus, a legacy device may be controlled by
the interoperability platform through an enhanced
legacy application, which is able to access and
subscribe to the smart space.