Military Communications and Information Technology: A Trusted ...

Chapter 1: Concepts and Solutions for Communications and Information Systems
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employed incompatible data types; their integration would be extremely complex.
Thus, for our routing service, we have decided to divide the server into a number
of separate elements, each offering a compact API and performing a well-defined
task. As a result, the server is composed of the following components (refer to Fig. 2):
• Input/output, a component responsible for handling messages for clients,
providing security (if necessary) and dealing with quality-of-service issues
(also – if necessary);
• Database, containing the static map and dynamic data (section IV);
• Graph builder, responsible for transforming map data into a graph (section V);
• Adapter(s), computing graph weights (section VI);
• Algorithm(s), performing route optimizations (section VII);
• Finally, dispatcher, managing the above-mentioned elements (section VIII).
Figure 2. The route server’s internal architucture
The server is implemented in the Microsoft .NET framework environment.
The software architecture is organized around a number of interfaces (with each
component having its dedicated interface(s)) and components (classes contained
in .NET assemblies) that implement these interfaces and may be easily replaced
for research or testing purposes. For example, adapters and algorithms (see sections
VI and VII) are dynamically loaded according to the server’s configuration.
In the following sections, we describe each of the server’s components in detail.
IV. The Database: Static Map and Dynamic Data
We have selected the OpenStreetMap [8] project as our source of static maps.
OSM provides free geographic data for the whole world. The data may be encoded
in XML or stored in a PostGIS [14] database (with conversion performed