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21
Designing the MOBIlearn
Architecture
M
OBIlearn's Open Mobile
Application Framework (OMAF)
was proposed after six months of work.
12
Further work then concentrated on defi-
ning the required mobile and generic ser-
vices. Looking back, it seems remarkable
that this service-based design was confir-
med at the project meeting without an
in-depth discussion.This was probably due
to the fact that the consequences and the
significance of the proposed usage of a
service-based framework were not realised
by many of the partners.This may be
explained in part by the mixed technical
competencies available in the project and
by the predominant effort (at that time) of
analysing the demands from a user point
of view. It took until project month 12 to
realise widely within the project that this
approach, while being very much in line
with current trends in software develop-
ment, posed a number of additional chal-
lenges.
Challenges and Obstacles
There is currently little technological
experience in designing a service-based
system
Software development tools are just
beginning to support the development of
individual services and there is almost no
tool support for the development of a
complete system of services
The usefulness of a system of services is
hard to evaluate by the representatives of
the potential end-users
In addition to the co-ordinated develop-
ment of a system of independent services,
this poses new challenges to the project
management, especially in taking care of
the emerging dependencies between dif-
ferent services and workpackages
Having independent services which
communicate through the exchange of
messages poses problems of distributed
data storage and synchronisation
The large communication traffic bet-
ween the services may pose efficiency
problems to the overall system
Benefits
Applications for different scenarios can
be easily assembled from the various ser-
vices
Additional services, including those from
other parties, may be integrated relatively
easily
Existing systems can be reused by wrap-
ping them into service envelopes.This
allows each service developer to use the
most efficient tools and programming
languages for his/her purpose. Re-imple-
mentation in a common programming
language is avoided
The project management can concentra-
te on the co-ordination of the design
and implementation of the mutual servi-
ce calls, and leave issues of data structures
and algorithms to the implementing
teams
MOBIlearn services may be reused out-
side the MOBIlearn project through
their open communication interfaces
The high-level design of the system of
services allows an early analysis of the
emerging system and its comparison
with the requirements from the users'
point of view
Service-based architecture
12The experienced reader may note that there is a consid-
erable similarity with the framework proposed by the
Open Knowledge Initiative (OKI) led by the MOBIlearn
partner MIT.This is intended in order to foster future co-
operation between both projects.
Figure 1.The OMAF Layers
MOBIlear
n 2004,
http://www
.mobilear
n.org (kindly offer
ed b
y IPM Gr
oup)
MOBIlear
n,
2004,
http://www
.mobilear
n.org