Title:
  An Algorithm for Hierarchical Network Design

Author:
  Frederico Rodrigues Borges da Cruz

Abstract:
  The primary network of a telephone switching center is presented as a 
hierarchical network. In such a network, a root node (switching center) 
distributes flows to terminal nodes (distribution boxes) via a set of 
demand concentrators. A 3-phase hierarchical network design algorithm is 
presented. First, the fixed-charge p-median problem formulation is used 
to locate the concentrators. For each concentrator's network, a good 
topology is obtained by solving a mixed integer programming problem through 
addition and interchange of arcs. The third phase uses a similar model to 
connect the concentrators to the root node. The proposed algorithm is 
implemented. Also presented are the data flow diagrams, data dictionary, and the 
module hierarchical diagrams of the implemented system. The 3-phase 
algorithm results show that good solutions can be obtained for the 
hierarchical network, in spite of not being the best. Large networks are 
solved (200 nodes) and the solutions show that the CPU time grows quickly 
with the problem size.

Keywords:
  Hierarchical network; heuristic; location.