The motivations for selecting each specific component for the implementation of the
system architecture is described in the Case Study chapter above. Still, there are a
number of design considerations that merit further discussion.
The use of WMS requests in EDCA, to return the data from the geospatial server as map
images instead of returning the actual data which would be the case if using WFS, is
one such consideration. The main advantages to WMS compared to WFS are, firstly,
that even as the amount of features or map details become very large, the bandwidth and
consequently time and battery use for transferring one WMS map image remains
practically the same. Secondly, by fetching WMS images from the geospatial server,
control over map symbology can be left to the system administrators (unless a client
would let users supply their own symbology for each map request). This spares work for
EDCA users and ensures that users can be provided with consistent and efficient map
symbologies. Thirdly, the fetching and displaying of WMS images required
significantly less effort during development. Fourth, providing clients with map images
directly adds a measure of security by not distributing the actual spatial data.