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The source graphic, a Windows Metafile (WMF), for the TSD can be downloaded here:
TSD
The following discusses how the National ITS Architecture provides the transportation service described by this service package. Each numbered item describes the operation of that portion of the service package identified with the corresponding number on the transaction set diagram.
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Periodically, possibly by subscription or by regularly scheduled requests, vehicle systems and personal devices may request (map update request) and download map updates from a Map Update Provider. For autonomous route guidance, most likely this would come by way of some memory media (e.g., CD) and the vehicle or personal equipment would be updated accordingly.
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Optionally, asynchronously, and as often as desired, a driver may request (driver inputs) a route from the vehicle.
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Once a route is requested by the driver (driver inputs), a continuous cycle occurs, consisting of these steps: the updated position of the driver (position fix) is obtained, real-time, the Vehicle Subsystem computes the best route from the current position to the destination, and then the next route guidance instructions (driver updates) is provided to the driver.
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Optionally, asynchronously, and as often as desired, a traveler may request (traveler inputs) a route using a personal computing device (PDA, cell phone, or other mobile device).
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Once a route is requested by the traveler, a continuous cycle occurs, consisting of these steps: the updated position of the traveler (position fix) is obtained, the Personal Information Access Subsystem computes the best route from the current position to the destination, and then the next route guidance instructions (traveler interface updates) is provided to the traveler.
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