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into how to develop a location-based mobile aug-
mented reality engine.
6 SUMMARY & OUTLOOK
The purpose of this paper was to give insights into the
development of the core framework of an augmented
reality engine for smart mobile devices. We have fur-
ther shown how business applications can be imple-
mented based on the functionality of this mobile en-
gine. As demonstrated along selected implementation
issues, such a development is very challenging. First
of all, a basic knowledge about mathematical calcu-
lations is required, i.e., formulas to calculate the dis-
tance and heading of points of interest on a sphere in
the context of outdoor scenarios. Furthermore, deep
knowledge about the various sensors of the smart mo-
bile device is required from application developers,
particularly regarding the way the data provided by
these sensors can be accessed and processed. Another
important issue concerns resource and energy con-
sumption. Since smart mobile devices have limited
resources and performance capabilities, the points of
interest should be displayed in an efficient way and
without delay. Therefore, the calculations required to
handle sensor data and to realize the general screen
drawing that must be implemented as efficient as pos-
sible. The latter has been accomplished through the
concept of the locationView, which allows increasing
the field of view and reusing already drawn points of
interest. In particular, the increased size allows the
AREA engine to easily determine whether or not a
point of view is inside the locationView without con-
sidering the current rotation of the smart mobile de-
vice. In addition, all displayed points of interest can
be rotated easily.
We argue that an augmented reality engine like
AREA must provide a sufficient degree of modular-
ity to enable a full and easy integration with existing
applications as well as to implement new applications
on top of it. Finally, it is crucial to realize a proper
architecture and class design, not neglecting the com-
munication between the components. We have fur-
ther demonstrated how to integrate AREA in a real-
world business applications (i.e., LiveGuide) and how
to make use of AREA’s functionality. In this context,
the respective application has been made available in
the Apple App and Android Google Play Stores. In
particular, the realized application has shown high ro-
bustness. Finally, we have given insights into the dif-
ferences between Apple’s and Google’s mobile oper-
ating systems when developing AREA.
Future research on AREA will address the chal-
lenges we identified during the implementation of the
LiveGuide business application. For example, in cer-
tain scenarios the POIs located in the same direction
overlap each other, making it difficult for users to pre-
cisely touch POIs. To deal with this issue, we are
working on algorithms for detecting clusters of POIs
and offering a way for users to interact with these
clusters. In (Feineis, 2013), a component for on-the-
trail navigation in mountainous regions has been de-
veloped on top of AREA, which is subject of cur-
rent research as well. Furthermore, we are develop-
ing a marker-based augmented reality component in
order to integrate marker based with location based
augmented reality. Since GPS is only available for
outdoor location, but AREA should also for indoor
scenarios, we are working towards this direction as
well. In the latter context, we use Wi-Fi triangulation
to determine the device’s indoor position (Bachmeier,
2013). Second, we are experiencing with the iBea-
cons approach introduced by Apple.
Finally, research on business process management
offers flexible concepts, which are useful for enabling
proper exception handling in the context of mobile
applications as well (Pryss et al., 2012; Pryss et al.,
2013; Pryss et al., 2010). Since mobile augmented
reality applications may cause various errors (e.g.,
sensor data is missing), adopting these concepts is
promising.
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