1. Introduction to ISP to Traffic Management & Transit Management
Subsystems
This Standards Requirements Package has been specially prepared to highlight the ISP to TMS
and ISP to TRMS interfaces as currently defined in the US ITS National Architecture. The
content of this package has been selected from the ITS National Architecture Standards
Requirements Package Chapters 6 and 10. The last chapter, the Data Dictionary, was prepared
by taking a special "cut" through the Access Databases for the entire Data
Dictionary, so that only the relevant primitive and composite flow data dictionary entries are
present.
The focus of these specifications is on the message layer. In the "ISO Stack"
terminology this is level 7, the "application" layer. It is assumed that the physical
connection between these ITS Center subsystems will be relatively high bandwidth wireline
using TCP/IP or equivalent at ISO layers 3/2.
The diagram which follows shows the ISP, TMS and TRMS subsystems, with the
architecture flows between them (not showing TMS to TRMS flows) as defined in the current
version of the National Architecture. In the following sections, the sequences of messages (or
"transaction sets") used to implement information transfer services will be presented.
Also shown is how the architecture flows hierarchically decompose into more primitive logical
information flows.
Finally, a subset of the National Architecture Data Dictionary is included with definitions of
each of the logical flows named in the previous sections. An alternative way to decompose any
specific flow to its logical primitives in the data dictionary is to use the National Architecture
browsing web site:
http://www.rockwell.com/itsarch/
Please contact me if you have any problems using the website. Many people, including
many of us on the National Architecture team, use the web site regularly and find it far preferable
to the paper documentation.
The preparation of this document was motivated based on an exchange of email between
myself and Steve Dellenback, South West Research Institute (SWRI) of the San Antonio MDI
Team, where the idea was raised of "what does the NA have to say about these interfaces,
in a concise way" (or something like that). This is a first cut.
Robert S. Jaffe
Jaffe Engineering and Development Industries (for Lockheed Martin Federal Systems)
rsj@jeng.com
914-248-6072
914-248-5840 (fax)
Figure 1 . Information Service Provider to Traffic/Transit Management
Subsystem Architecture Flows
