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5.1.3 Contact Platform Distribution - High Data Rates

Figure 11 indicates one possible functional distribution for a contact subsystem based on the previous loading analysis.

Figure 11. Contact platform and workload distribution for high data rates.

The service layer components required for each set of allocated functions are included as resident on the designated platform. The TFE/CFE platform requires the DBMS to retrieve wavetrain processing and command constraint checking parameters, the O/S to manage executables loaded to the front-end, and Timing to manage both telemetry time-tagging with the IRIG-B stream and critical command transmission timing. The Telemetry and Commanding functions communicate with each other and with functions on other platforms through their unique APIs and the common Distribution Services.

The Workstation platform requires fewer services than TFE/CFE. The O/S manages applications and the HCI executes display functions for Telemetry, Commanding, and GSS data. Although display formats are shown in Figure 6 as a database item, they may be stored in flat files and not managed by a DBMS. Security services are indicated on the display workstation because they control user access.

The Contact Server uses the most services among the three platforms. Distribution Services provide interconnections to the other platforms through the LAN and receives GSS data over the LAN. The DBMS retrieves additional wavetrain processing parameters, such as Engineering Unit (EU) conversions; and commanding parameters, such as static verification. Configuration Management checks the versions of the applications and databases used during contact. Application Management retrieves executables for each application from a central file server (not shown on the diagram), distributes them to the assigned platform, and manages task execution. The File service ensures that data files not managed by the DBMS are retrieved and that archive files are properly stored. The Security service provides access controls for data routing and for user access to the contact functions in a manner complementary to the services on the display workstation. Finally, the Decision Support System service manages execution of knowledge bases that support the allocated Telemetry, Commanding, and GSS functions.

It should be noted that in these diagrams, assignment of functions to platforms does not imply any restrictions regarding where the executable is stored on disk. These allocations are simply meant to indicate a reasonable and workable execution-time arrangement. Network file sharing and DBMS software will ensure that all data (including executables) is available to all platforms.