Telecommunications outside plant management throughout brasil
In spite of requiring from the GIS the support for imaging we have not being able to derive the
advertised benefits from its technology. However, imaging is provided in SAGRE. We are
fortunate that the GIS we selected remains competitive in this area. Some of our users implement
a two-step strategy with regard to imaging, where imaging (AM) comes first and then,
?incrementally, the data is raised to the FM level. SAGRE allows the placement of images in any
map or schematic as a background drawing and also to store an image linked to any of its
objects, even if they do not have a graphical representation. Also, these images can be checked
out and in for integration with other imaging systems.
Architecture
TELEB~S has developed an integrated operations support system plan and architecture. The
plan defines the main sub-systems and databases to fulfill the functional needs of our operating
companies. SAGRE follows that plan and architecture.
SAGRE architecture is open and built on three layers: user interface, application rules, and GIS
database.
The database layer is the core of SAGRE, and has been designed using object oriented
techniques. The GIS adds greater flexibility and uniformity to this layer because it uses a
commercial relational data base management system to store both spatial and nonspatial data,
Both interface and application layers are based on object oriented standards. All layers are driven
by metadata to encapsulate interface, data base and application objects. This has made possible
the development of dynamic user interfaces and operations, whose components are specified at
run time (Oliveira 95).
The metadata capability accelerated the development by reusing not only code but also design
characteristics. The architecture also enabled the derivation of our conversion methodology that
collects converted data in an object oriented fashion much like the on-line operations.
A major challenge was to reconcile two entirely different user work modes -- operations and
design/planning. Most of Operation transactions originate from customer phone calls regarding
service repairs and changes. The Design mode comprises long duration activities as opposed to
short operational transactions. The engineers interact with the database in order to pose spatial
queries that analyze the existing facilities against projected demand for a given region. Design
work is conditional and should not affect existing data unti 1the work is constructed.
SAGRE must thus be able to support such activity profiles, and the database must consider
concurrent access by both maintenance and design/operations teams. To allow integration of
these processes, the project had to use check-in/check-out and versioning mechanisms. Besides
supporting alternative designs, this allows cooperative work among design and operational teams
(Dias 95).
Another architectural feature in SAGRE is its ability to integrate a CAD tool into the design
process. With this feature, we can start deploying SAGRE with the help of a CAD tool while
conversion is taking place.
Implementation
Although it is very well known that systems like SAGRE take a long time to be implemented, the
end users cannot wait for the completion of the whole system. We decided to build a first
version after completion of data modeling but with limited functionality. This version had
several objectives:
(a) to come out with some functionality to satisfy the end users pressure;
(b) to test the modeling with real data;
(c) to get feedback on the user interface;
(d) to start data conversion.
This decision proved to be very good. Note that this first version was not a prototype. It had
limited functionality but implemented the complete data base structure. Usually, a prototype is
constructed and a pilot is made. Sometimes, conversions are made without knowing the final
data model causing many problems when trying to save conversion work. This approach also
allowed us to modifi the paradigm of data conversion that will be discussed later in this paper.
SAGRE first version was the seed for two of its modules, the SAGRE/Records (Gonqalves, 94)
and SAGRE/Conversion modules. SAGRE/Records maintains the existing plant database and
SAGRE/Conversion implements our conversion methodology and tools.
While maintaining the first modules, we started designing and implementing the complete
functionality. The data model proved to be very stable but the user interface, as expected, had
many problems. We learned that we should have taken more time in the construction of the
interfaces. A new interface model was built and the complete system architecture was
implemented. A new SAGRE/Records and SAGRE/Conversion, the SAGRE/Administration,
SAGRE/Design, and SAGRE/Operations comprise the functionality required for SAGRE
(Prezzoto, 95).
The high investment we did in modeling the database is paying off gradually. The database is
steadily supporting the architectural enhancements being implemented as well as the increase in
functionality required by the end users. Also, the databases being constructed with the
conversions are coming up with sizes unexpectedly small. We believe this is also due to the GIS
data structure.
Deployment
We learned from the beginning that conversion was the biggest problem to be considered in an
AM/FM/GIS system. With the release of SAGRE/Records version 1.0 we started a bid for a pilot
conversion. With the help of consultants we knew that doing in-house conversion could be a bad
decision. Conversion requires specialized assembly line type of work. The bid called for the
traditional conversion approach -- the conversion company would handle the data in our GIS
interchange (low level and proprietary) format. We were not satisfied with the situation since the
390?Brazilian conversion market had very little experience with GIS conversion, and in particular,
with the GIS we were using. Before the closing date for the bid, we decided to change the format
(and the paradigm) of the conversion. We came out with an (land base and outside plant) object
oriented format to be handled by SAGRE/Conversion module (Magalhiles, 94b).
The methodology and tools we adopted are based on the idea of manipulating the systems objects
in the same level of the user interface. For example, to lay an aerial cable segment the user
selects the poles, draws the cable path, enters the attribute data, etc., then the conversion data
should resemble this mode of operation. The conversion company receives a detailed technical
specification on how to read the maps and forms information and translate them into our
standard format. Conversion data is input in batches. Each batch is submitted to
SAGRE/Conversion module that reads the conversion data, makes the same consistency check
performed by SAGRE/Records, resolves the elements continuity problems due to maps
boundaries, reports all errors, calculates quality assurance figures, and separates batch into two
others -- the set of objects that have been entered correctly and the set that did not enter due to
errors. The data allowed into the system may have only layout problems, which is also
minimized due to graphical consistency checks. For example, duplicate geometry is not allowed.
This pilot conversion was set to provide us with: costs and timing for the Brazilian context;
validation of the conversion technical specification; experience with contracting and accepting
conversion work; a broader knowledge of the process; levels of quality assurance; qualification
of conversion vendors; a real life and complete database representative of our reality for testing
and integration of SAGRE modules. The pilot was a success and its pioneer data has helped
TELEBRAS to cut significantly the conversion cost and complexity.
SAGRE conversion methodology and tools are evolving continuously. Each time a new
conversion bid is set improvements are made in order to allow the operating companies to move
into SAGRE faster without reducing quality level.
Conclusions
SAGRE is a system that has pushed AM/FM/GIS into the mainstream of TELEBRAS technology
support. The key decision that allowed us to arrive earlier in this status was to develop a system
to cover the entire outside plant information life cycle. Also, we had the courage and support to
try new technologies and methods that worked well. In this process we took advantage of the
cooperative spirit of the AM/FM community by sharing experiences with many users and
vendors.
Acknowledgments
SAGRE is a cooperative effort among TELEB~S R&D Center and the Operating Companies.
Our Operating Companies contributed in the developments in many aspects. In particular, they
contributed with dedication in the specifications, system testing, prototyping and pilot
implementations. In the R&D Center, a group of engineers and system analysts work on SAGRE
design and implementation. SAGRE success is owed to all these people.
References
Magalhiies, G C, 1994, The development open systems for engineering applications: Proceedings
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Oliveira, J., Cunha, C. and Magalhiies, G. Object model for dynamic visual interfaces
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Dias, E., Granado, S., and Magalh~es, G. The use of versions to enforce consistency in hybrid
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