Mobility Applications
Mobility
applications are applications that handle transmission of data and user
interaction between wireless devices and a central repository. Broadly,
we can divide the mobile applications as synchronization, real-time,
and hybrid applications.
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Synchronization applications (SA) handle data
transfers in situations where the user is not connected to the central
database on a real-time basis. Instead of an instant data transfer, the
user occasionally synchronizes the data residing on a mobile device
with either a PC application or (potentially) a server. In this
scenario, the user must schedule when the synchronization occurs and
must be connected to a network of some type at that time. SAs work with
a thick client that contains most or all of the data. During the
synchronization process, the mobile device receives new or updated
data, or the device sends its data to the PC or server. SAs are clearly
very effective because they allow the user to access and carry critical
information while on the go. [11]
Synchronization in many cases should be the preferred means of data
transmission, given the current wireless Internet networks' limited
bandwidth and connection reliability, especially for business
applications that are not time critical or that do require large
amounts of data to be transferred back and forth from the device.
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Real-time applications connect in real-time only.
Examples include WAP connections over cell phones, PDAs with wireless
Internet connectivity, or applications that are available if and only
if there is a connection at the exact moment that the information is
needed. The distinction here is that limited data is kept on the mobile
device and the data that the user wants to see is accessible only at
the time that a reliable network connection can be established. This
type of application is the one we commonly think of when using the term
mobile commerce, as the term implies that the activities are happening
in real-time exclusively. Many applications that contain time-critical
elements and low data volumes, such as financial trading applications,
bidding in auctions, and status tracking, require such connectivity to
function reliably and meaningfully.
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Hybrid applications are only sporadically
connected. These applications typically have a thick client, one that
will process interactions in real-time if the real-time connection can
be established, but queue the transaction and do something else (in the
context of the business process) when the connection is not available.
When the connection becomes available again, the queried interactions
are processed at that time.
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Many of the most-valued hybrid applications
automatically detect the availability of a connection and then choose
whichever means of connectivity is most applicable. The important part
here is that the user of these applications does not have to know
whether the applications are connected or
not. The software performing the applications will take care of the
connectivity and render it mostly invisible to the user. Obviously, if
we are in need of real-time access to satisfy a query but are not
connected, then we will receive an error message. However, most
information can be fetched ahead; it can be synchronized, and it can be
available with some degree of currency although the wireless connection
may not be available at the exact time of processing.
Each application being designed today falls into
one of the categories listed in this section. It depends on the
situation and the real business needs that drive the application
itself. If a user can satisfy his or her needs with an occasionally
connected application, developing such an application is usually much
less expensive and complex than building a real-time solution. Having
the wireless Internet, real-time connectivity certainly has some
benefits in terms of the data being current, but one most weigh the
disadvantages of such an approach, mostly stemming from the fact that
connectivity is not always available in key locations. Handheld devices
come in all shapes and sizes, with many more currently being developed
in manufacturers' research labs around the globe.