Schematics, as Output
The Schematic Generator
How The Generator Works
Figure 1. Generated Schematic
Typical AM/FM systems are capable of tracing a network once the Items of Plant have
been connected. A trace maybe used to generate a report or modifi attributes of the
features in the traces path. In the telecom case, pair counts maybe modified during such
a trace.
To generate a schematic, the network is traced producing records of features contained in
the network. The database is then queried for supplemental information such as address
names etc. Once all the network information has been extracted from the database, a
diagram is produced, graphically representing the traced network.
Advantages
Israel’s Bezeq with Formula Ltd. have developed an Outside Plant schematic generator.
When designing or converting an outside plant network, an operator places only the
graphics representing the location/geometry of the items of plant. No connectivity
information is entered graphically or displayed on a map. This has resulted is extensive
time savings in the preparation of details.
In addition, automatic connectivity fi.mctions may be developed so that complex
connectivity scenarios may be automated. When converting existing network maps and
records, connectivity information may be entered alphanumerically rather then entered
while drawing graphics. In other words, no lines are drawn to describe how two cables
are connected.
Examples:
- When connecting a feed cable to a number of fed cables pairs are automatically
assigned based on the demand of each fed cable.
- Certain complex connectivity scenarios which periodically repeat, maybe automated,
further reducing the time required to connect a series of cables.
Graph theory and Computer Algorithms
Tree Networks
In telecommunications, common copper networks fall under the category of a tree
network or tree “graph”. Therefor by recursively sorting the traced data, all connections
at a particular vertex are isolated and each vertex is assigned a location within the tree.
The algorithm computes graphics of each vertex, the size of each vertex and the physical
location on the diagram. A list of modifiable parameters are listed in an initialisation
(.ini) file and the graph is drawn based on the parameters.
Recent enhancements to the generator allow the schematic to “fold” so that a schematic
will grow down, rather than across the page. Traditional (hand drawn) joint diagrams
cluster all joints which are located geographically at the same point (e.g. on the same
pole/hole) at the same graph location. A tree graph will position each joint at a location
based on the joints logical tree position. This limitation often requires utility technicians
to get used to a new form of diagram. We found that the benefit of clear computer
generated documents strongly outweighed the initial discomfort of learning the new
format.
Fiber Networks and Redundant Rinm
In the case of optic networks, redundant ring technology is used and does not conform to
the tree model. Therefor a specific solution was provided for the case of redundant rings.
This solution was an adaptation of the tree network generator and not a full blown
network graph. Since the classic telephony model is a tree (feed to fed) model, reverse
connectivity was added to the model in order to describe the backup connections in a ring
network.
Non Tree Graphs
An AM/FM schematic generator is a perfect application of graph theory. The next step in
the development of a schematic generator is the implementation of a non-tree schematic.
This type of schematic will be able to produce:
- Traditional joint diagrams where a single vertex maybe defined as a geographic
location such as a hole or pole.
- Schematics for non-tree utility networks (e.g. electrical).
- Better support of non-tree telecom networks.
For more information on graph theory, see
http://www.math. fau.edu/locke/graphthe.htm
