Common Logical Data Model: Basis for Global ITS Innovation
vehicle and all of the recipients of the
information must agree on:
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Even more challenging is the fact that this
information sharing is envisioned to be
exchanged between vehicles and nearby
pedestrians through smartphones. In order
to interoperate, that smartphone needs to
agree on the vehicle’s location even if the
smartphone app is from a different part of
the world.
What coordinate system is being
used (i.e., a specific global
coordinate system or perhaps a
coordinate system based on the
center of an intersection)
What reference point on the vehicle
is being used to locate the vehicle
on the coordinate system
How accurate the data claims to be
How timely the data claims to be
From a theoretical, idealistic viewpoint, we
would develop the standards in a slow,
considered manner, analyzing all business
needs before finalizing any data definitions
or data interface; but that approach would
not meet the real-world business needs. A
more viable alternative is to allow each
market segment to continue the
development of their specific data interface
standards while promoting the concept of a
higher-level model that will define how to
share data among the different interchange
formats.
As mentioned above, within the ITS industry,
there are dozens of standards development
bodies that are actively defining the details
about such interactions. Each of these
groups have their own market interests as
well as their own business pressures to
produce quality documents in a timely
manner. However, the complexity involved
in many of these technical issues makes it
difficult to address all integration issues
within the timeframes desired to meet
business objectives.
Data Model Framework
The proposal to develop a harmonized
higher-level model that provides for
interoperability includes a three-layer design
as presented in Figure 3:
The result is that each standard developed
tends to develop its data to meet its isolated
business objectives, often resulting in
limited coordination among different
standards groups. As a result, we end up
with competing definitions for the reference
point of a vehicle between the European and
American communities—even though most
automobile manufacturers operate globally
and will end up having to produce vehicles
that conform to both standards.
IIC Journal of Innovation
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A conceptual model that defines the
vocabulary for the industry using a
formal ontology
A logical data model that defines the
standardized generic representation
of data using object classes and
attributes
Physical data models that represent
each interface standard